Note: Descriptions are shown in the official language in which they were submitted.
:4 84218282
TRACK.SYSTEM FOR TRACTION OF AN AGRICULTURAL VEHICLE
TRAVELLING ON FIELDS AND ROADS
This is application is a divisional application of Canadian Patent Application
Serial
No. 2899527 filed on August 4, 2015.
FIELD OF THE INVENTION
The invention relates generally to agricultural vehicles (e.g., tractors,
harvesters,
combines; etc.) and, more particularly, to track systems for traction of
agricultural
vehicles.
BACKGROUND
Agricultural vehicles (e.g.,. tractors, harvesters, combines, etc.) sometimes
comprise
track systems (Instead of tire-equipped wheels) to enhance their traction and
floatation in agriCultural fields, which may be soft, slippery, and/or uneven
(e.g'., soil,
mud, etc.).
In addition to travelling in agricultural fields to perform agricultural work,
agricultural
vehicles are often "roading, i.e., travelling on roads, such as between
different
fields, When on a road, an agricultural vehicle's track systems are exposed to
conditions that are completely different than those in a field and can
drastically affect
their performance. Notably, the road's hard surface, which rnay be, relatively
hot, and
a typical desire of the vehicle's operator to move the vehicle faster on the
road .(e.g.,
to minimize non-productive time out of the field) may result, in severe wear
and
deterioration of the vehicle's tracks, which may lead to their premature
failure.
The applicant has discovered that, under certain operating conditions, an
agricultural
vehicle's tracks, which have a carcass that is, reinforced, can fail very
quickly during
roading. For instance, tracks with An expected useful life ef 2600 or 3000
hours in a
field deteriorate significantly within merely a few hours of roading. The
economic
consequences for the vehicle's operator are severe because a failed track,
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especially one in which the carcass has been damaged, cannot readily be
repaired
and must typically be replaced.
Without intent of being bound by any particular theory, the actual failure
mechanism
of a track's carcass is believed to be essentially a succession of failures of
different
components of the track, which progressively increases the strain on the
carcass
until it fails as well.
To elaborate, as the vehicle is driven on the road, heat buildup starts to
develop in,
to the track's tread projections (sometimes referred to as "traction
projections", 'traction
lugs" or "tread bars") that 'project from the track's ground-engaging outer
surface. The heat buildup can increase the internal temperature of a tread
projection
to a point at which the internal elastomeric material outgases, increasing the
internal
pressure of the tread projection until it bursts. The effect of such "blowout"
is to
produce a void volume in the tread projection, which reduces its load carrying
capacity. As a result of the void volume, the tread projection structurally
collapses
and loading is directly transferred to the carcass underlying the tread
projection. The
blowout of multiple traction projections, as shown in Figure 38, exposes the
carcass
in that area of the track to loading that it is not designed to sustain. As
shown in
Figures 39 and 40, the loading can rapidly wear down the carcass and expose
its
reinforcements, such as its cables, which in turn can wear down causing a
complete
failure of the track.
Tests performed by the applicant have identified an operaticinal range of the
vehicle,
which is characterized by certain speed, load, and track width factors in
which the
failure mode occurs almost uncontrollably. In other words, when the vehicle is
roading in that operational range, the cascade of failure events can occur
very
quickly following an initial blowout event. It is very difficult for the
operator to detect
the occurrence of the initial blowout such that even attentive operators
cannot react
quickly enough to prevent the track destruction.
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The operational range in question tends to be at or beyond the operational
limit of
the vehicle, that is, above the manufacturer recommended maximal speed and
maximal weight. Yet it constitutes a desired operational range because the
vehicle
is the most productive in those conditions. Accordingly, from an efficiency
perspective, operators tend to operate their vehicles as near as possible to
those
limits, with the risk that the track may suffer from a catastrophic failure.
Roading may also cause severe damage to other components of the agricultural
vehicle's track systems, including idler wheels (e.g., front or read idler
wheels, or
intermediate roller wheels) that contact a track's inner side. For example,
this may
cause a peripheral covering of an idler wheel to damage its treaded outer
surface,
as shown in Figure 41, and/or fail entirely as shown in Figure 42.
For these and other reasons, there is a need to provide an improved track
system
for an agricultural vehicle that can notably reduce the risk of failure of its
track's
carcass when the vehicle is roading, such as when operated in the above-
defined
operational range.
SUMMARY OF THE INVENTION
According to various aspects of the invention, a track system for traction of
an
agricultural vehicle is configured to better perform when the agricultural
vehicle is
roading, including to reduce or minimize deteriorative effects on a track of
the track
system as the agricultural vehicle travels against a road's hard surface,
especially at
higher speeds.
For example, according to an aspect of the invention, there is provided a
track
system for traction of an agricultural vehicle. The track system comprises a
track and
a track-engaging assembly for driving and guiding the track around the track-
engaging assembly. The track comprises elastomeric material to flex around the
track-engaging assembly. The track also comprises a reinforcement within the
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elastomeric material. The track-engaging assembly comprises a .drive wheel for
driving the track and a plurality of idler wheels for contacting a bottom run
of the
track. The track system comprises an enhanced-roading feature to facilitate
travel of
the agriculture vehicle on a road. A speed restriction for the agricultural
vehicle on
the road is laxer than if the enhanced-roading feature was omitted but the
track
system was otherwise identical.
According to another aspect of the invention, there is provided, A track
system for
traction of an agricultural vehicle. The track system comprises a track and ,a
track-
engaging assembly for driving and guiding the track around the track-engaging
assembly. The track comprises elastomeric material to flex around the track-
engaging assembly. The track comprises a reinforcement within the elastomeric
material. The track-engaging assembly comprises a drive wheel for driving the
track
and a plurality of idler wheels for contacting a bottom run of the track. The
track
system comprises a lateral load distribution mechanism configured such that
bottom
track-contacting areas of laterally-adjacent ones of the idler wheels are
movable
relative to one another in a height direction of the track system when the
agricultural
vehicle travels on a road. A speed restriction for the agricultural vehicle on
the road
is laxer than if the bottom track-contacting areas of the laterally-adjacent
ones of the
idler wheels were not movable relative to one another in the height direction
of the
track system when the agricultural vehicle travels on the road but the track
system
was otherwise identical.
According to another aspect of the invention, there is provided a track system
for
traction of an agricultural vehicle. The track system comprises a track and a
track-
engaging assembly for driving and guiding the track around the track-engaging
assembly. The track comprises elastomeric material to flex around the track
engaging assembly. The track comprises a reinforcement within the elastomeric
material. The track-engaging assembly comprises a drive wheel for driving the
track
and a plurality of idler wheels for contacting a bottom run of the track. The
track
system comprises a lateral load distribution mechanism configured such that
bottom
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track-contacting areas of laterally-adjacent ones of the idler wheels are
movable
relative to one another in a height direction of the track system when the
agricultural
vehicle travels on a road. A speed restriction for the agricultural vehicle on
the road
is defined in a zone SRZ indicated in a chart provided in Figure 43.
According to another aspect of the invention,, there is provided a method for
regulating a speed of an agricultural vehicle ori a road. The method comprises
providing a plurality of track systems for traction of the agricultural
vehicle. Each
track system comprises a track and a track-engaging assembly for driving and
guiding the track around the track-engaging assembly. The track comprises
elastomeric Material to flex around the track-engaging assembly. The track
comprises a reinforcement within the elastomeric material. The track-engaging
assembly comprises a drive wheel for driving the track and a plurality of
idler wheels
for contacting a bottom run of the track. The track system comprises a lateral
load
distribution mechanism configured such that bottom track-contacting areas of
laterally-adjacent ones of -the idler wheels are movable relative to one
another in a
height direction of the track system when the agricultural vehicle travels on
the road.
The method comprises conveying a speed restriction for the agricultural
vehicle on
the- road that is laxer than if the bottom track-contacting areas of the
laterally-
adjacent ones of the Idler wheels were not movable relative to one another in
the
height direction of the track system when the agricultural vehicle travels on
the road
but the track system was otherwise identical.
According to another aspect of the invention, there is provided a method for
26 regulating a speed of an agricultural vehicle on a road. The method
comprises
providing a plurality of track systems for traction of the agricultural
vehicle. Each
track system comprises a track and a track-engaging assembly for driving and
guiding the track around the track-engaging assembly. The track comprises
elastomeric material to flex =around the track-engaging assembly. The track
also
comprises a reinforcement within the elastomeric material. The track-engaging
assembly comprises a drive wheel for driving the track and a plurality of
idler wheels
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CA 3002278 2018-04-20
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for contacting a bottom run of the track. The method also comprises conveying
a speed
restriction for the agricultural vehicle on the road. The speed restriction
for the
agricultural vehicle on the road is defined in a zone SRZ indicated in a chart
provided in
Figure 43.
According to another aspect of the invention, there is provided a track for
traction of an
agricultural vehicle. The track is mountable around a track-engaging assembly
for driving
and guiding the track. The track comprises elastomeric material to flex around
the track-
engaging assembly. The track comprises a reinforcement within the elastomeric
material.
The track-engaging assembly comprises a drive wheel for driving the track and
a plurality
of idler wheels for contacting a bottom run of the track. The track comprises
a ground-
engaging outer surface, an inner surface opposite to the ground-engaging outer
surface,
and a plurality of traction projections projecting from the ground-engaging
outer surface.
Each traction projection comprises a top surface for facing the ground. A
width of the top
surface of the traction projection is greater than a height of the traction
projection.
According to another aspect of the invention, there is provided a method for
regulating a
speed of an agricultural vehicle on a paved road, the method comprising:
providing a
plurality of track systems for traction of the agricultural vehicle in an
agricultural field and
on the paved road, each track system comprising a track and a track-engaging
assembly
for driving and guiding the track around the track-engaging assembly, the
track
comprising elastomeric material to flex around the track-engaging assembly,
the track
comprising a reinforcement within the elastomeric material, the track-engaging
assembly
comprising a drive wheel for driving the track and a plurality of track-
engaging wheels for
contacting a bottom run of the track, the track system comprising a lateral
load
distribution mechanism configured such that laterally-adjacent ones of the
track-engaging
wheels are movable vertically relative to one another when the agricultural
vehicle
travels, including in the agricultural field and on the paved road; and
conveying a speed
restriction for the agricultural vehicle on the paved road defined in a
crosshatched zone
SRZ indicated in a chart expressing the speed of the agricultural vehicle as a
function of
a load on a rear axle of the agricultural vehicle as follows:
6
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24-
2
a)
/
a 16 s<
= /
14
12-
10_1_ ___________________ _
25060 30000 3560 4060 45000 5060 5650 6600 651000
Rear Arlo load i6s1
According to another aspect of the invention, there is provided in
combination: a plurality
of track systems for traction of an agricultural vehicle in an agricultural
field and on a
paved road, each track system comprising a track and a track-engaging assembly
for
driving and guiding the track around the track-engaging assembly, the track
comprising
elastomeric material to flex around the track-engaging assembly, the track
comprising a
reinforcement within the elastomeric material, the track-engaging assembly
comprising a
drive wheel for driving the track and a plurality of track-engaging wheels for
contacting a
bottom run of the track, the track system comprising a lateral load
distribution mechanism
configured such that laterally-adjacent ones of the track-engaging wheels are
movable
vertically relative to one another when the agricultural vehicle travels,
including in the
agricultural field and on the paved road; and a tangible medium conveying a
speed
restriction for the agricultural vehicle on the paved road defined in a
crosshatched zone
SRZ indicated in a chart expressing a speed of the agricultural vehicle as a
function of a
load on a rear axle of the agricultural vehicle as follows:
6a
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,
22- s SRZ
18
cp
14 /,
12-
_____________________________________________________
25000 30000 35000 40000 45000 50000 55000 60000 65000
Rea Axle Load (Ihsl
According to another aspect of the invention, there is provided a track system
for traction
of an agricultural vehicle in an agricultural field and on a paved road, the
track system
comprising a track and a track-engaging assembly for driving and guiding the
track
5 around the track-engaging assembly, the track comprising elastomeric
material to flex
around the track-engaging assembly, the track comprising a reinforcement
within the
elastomeric material, the track-engaging assembly comprising a drive wheel for
driving
the track and a plurality of track-engaging wheels for contacting a bottom run
of the track,
the track system comprising a lateral load distribution mechanism configured
such that
10 laterally-adjacent ones of the track-engaging wheels are movable
vertically relative to
one another when the agricultural vehicle travels, including in the
agricultural field and on
the paved road, wherein a speed restriction for the agricultural vehicle on
the paved road
is defined in a crosshatched zone SRZ indicated in a chart expressing a speed
of the
agricultural vehicle as a function of a load on a rear axle of the
agricultural vehicle as
follows:
6b
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2246 7177-
22 / SRZ
4: 18
16
14.
12
75000 30000 3' 40000 45000
50000 65000 60000 65000
Rea Axle Load 91s)
According to another aspect of the invention, there is provided a method of
operating an
agricultural vehicle in an agricultural field and on a crowned roadway, the
crowned
roadway having a crown extending in a longitudinal direction of the crowned
roadway and
5 a roadway surface that slopes downwardly away from the crown on opposite
sides of the
crown, the method comprising: equipping the agricultural vehicle with a
plurality of track
systems for traction of the agricultural vehicle, wherein each track system
comprises a
track and a track-engaging assembly for driving and guiding the track around
the track-
engaging assembly, wherein the track comprises elastomeric material to flex
around the
10 track-engaging assembly and a reinforcement within the elastomeric
material, wherein the
track-engaging assembly comprises a drive wheel for driving the track and a
plurality of
track-engaging wheels for contacting a bottom run of the track, wherein the
track system
comprises an enhanced-roading feature to allow the track system to at least
partially
accommodate a sloping of the roadway surface, wherein the track comprises a
ground-
engaging outer surface which forms a contact patch with the roadway surface,
and
wherein the enhanced-roading feature comprises a lateral load distribution
mechanism to
increase an area of the contact patch; operating the agricultural vehicle in
the agricultural
field; and operating the agricultural vehicle on the crowned roadway at speeds
up to a
speed restriction, wherein the speed restriction is conveyed by a provider of
the track
system.
6c
Date Recue/Date Received 2022-09-29
According to another aspect of the invention, there is provided use of an
enhanced-
roading feature to increase the speed at which an agricultural vehicle is
permitted to travel
on a crowned roadway and in an agricultural field, wherein the crowned roadway
has a
crown extending in a longitudinal direction of the crowned roadway and a
roadway surface
that slopes downwardly away from the crown on opposite sides of the crown; the
agricultural vehicle utilizes two or more track systems for traction of the
agricultural
vehicle; each track system comprises the enhanced-roading feature, wherein the
enhanced-roading feature comprises a lateral load distribution mechanism to
increase an
area of a contact patch between the track system and the roadway surface; and
the
enhanced-roading feature is configured to allow the track system to at least
partially
accommodate the sloping of the roadway surface.
These and other aspects of the invention will now become apparent to those of
ordinary
skill in the art upon review of the following description of embodiments of
the invention in
conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
A detailed description of embodiments of the invention is provided below, by
way of
example only, with reference to the accompanying drawings, in which:
Figure 1 shows an example of an agricultural vehicle comprising a track system
in
accordance with an embodiment of the invention;
Figures 2 and 3 show a perspective view and a side view of the track system;
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Date Recue/Date Received 2022-09-29
' 84218282
Figures 4 and 5 show a plan view and a side view of a track of the track
system;
Figure 6 shows an inside view of the track;
Figure 7 shows a cross-sectional view of the track;
Figure 8 shows a perspective view of a traction projection of the track;
Figure 9 shows a drive wheel of a track-engaging assembly of the track system;
Figure 10 shows mid-rollers of the track-engaging assembly engaging an inner
side
the track;
Figures 11 and 12 show perspective views of an idler wheel, and more
particularly of
a mid-roller, of the track-engaging assembly;
Figures 13 and 14 show a front view and a side view of the mid-roller;
Figure 15 shows the idler wheel mounted on its axle via a hub;
Figure 16 shows a partial cross-sectional side view of a lower portion of the
track
system, including a bogie for mounting the mid-rollers;
Figure 17 shows a top view of the lower portion of the track system with two
idler
wheels being omitted to show a hub of the idler wheels;
Figure 18 shows an example of an agricultural vehicle equipped with typical
track
systems travelling on a crowned road;
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Figure 19 shows the track system provided herein implementing a lateral load
distribution mechanism for evenly distributing a load along a widthwise
direction of
the track while the agricultural vehicle is travelling on the crowned road;
Figures 20 and 21 show an example of an embodiment of the lateral load
distribution
mechanism in which a suspension of the idler wheels is adapted to cause the
idler
wheels to engage the track evenly along the widthwise direction of the track
while
the agricultural vehicle travels over the crowned road;
Figures 22 and 23 respectively show a side view of the suspension of the idler
wheels if Figures 20 and 21;
Figure 24 shows an example of an embodiment of the lateral load distribution
mechanism in which an axle of the idler wheels is aritculated to cause a
rotation of a
.. respective idler wheel about an articulation of the axle;
Figure 25 shows a side view of the articulation of the axle in a first
configuration;
Figure 26 shows a top view of the articulation of Figure 25;
Figure 27 shows a side view of the articulation of the axle in a second
configuration;
Figure 28 shows an example of an embodiment of the lateral load distribution
mechanism in which the idler wheels are deformable to cause the idler wheels
to
engage the track evenly along the widthwise direction of the track while the
agricultural vehicle travels over the crowned road;
Figure 29 shows the idler wheel of Figure 28 in a first configuration when the
agricultural vehicle travels over a flat horizontal surface;
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Figure 30 shows the idler wheel of Figure 28 in a second configuration when
the
agricultural vehicle travels over the crowned road;
Figure 31 shows an example of an embodiment of the lateral load distribution
mechanism in which the bogie of the track system has a pitch and roll motion
capability to cause the mid-rollers to engage the track evenly along the
widthwise
direction of the track while the agricultural vehicle travels over the crowned
road;
Figure 32 shows the bogie of Figure 31 including an upper and lower frame of
the
bogie;
Figure 33 shows a cross-sectional view of the bogie taken along line 33-33 as
shown in Figure 32;
Figures 34 and 35 show a plan view and a side view of an example of an
embodiment of the track in which traction projections of the track have a
modified
shape and dimensions to minimize deterioration of the track;
Figures 36 and 37 show a plan view and a side view of another example of an
embodiment of the track in which the traction projections of the track have a
modified shape and dimensions to minimize deterioration of the track;
Figures 38 to 42 show damaged traction projections (i.e., blown out), a
damaged
carcass having a reinforcement (e.g., cables) exposed, and damaged idler
wheels of
a conventional track system as a result of roading;
Figure 43 is a chart representing a speed restriction for the agricultural
vehicle on
the crowned road as a function of a load on a rear axle of the vehicle, and
more
particularly shows a speed restriction zone comprising speed restrictions of
the
vehicle when the agricultural vehicle has an enhanced-roading feature;
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Figures 44 to 48 are charts showing examples of speed restriction subzones for
the
agricultural vehicle when the agricultural vehicle travels on the crowned
road;
Figure 49 is a chart showing a speed restriction for the agricultural vehicle
on the
crowned road when the lateral load distribution mechanism allows a roll motion
of
laterally-adjacent ones of the idler wheels;
Figure 60 shows an example of an agricultural vehicle comprising two track
systems
rather than four; and
Figure 61 shows an example of a trailed vehicle configured to be attached to
the
agricultural vehicle of Figures 1 or 50. _
It is to be expressly understood that the description and drawings are only
for the
purpose of illustrating certain embodiments of the invention and are an aid
for
understanding. They are not intended to be a definition of the limits of the
invention.
DETAILED DESCRIPTION OF EMBODIMENTS
Figure 1 shows an example of an agricultural vehicle 10 in accordance with an
embodiment of the Invention. In this embodiment, the agricultural vehicle 10
is a
tractor. In other embodiments, the agricultural vehicle 10 may be a combine
harvester, another type of harvester, or any other type of agricultural
vehicle.
The agricultural vehicle 10 comprises a frame 12, a powertrain 15, a steering
system
17, a plurality of track systems 161-164 (which can be referred to as
"undercarriages% and an operator cabin 20 that enable an operator to move the
agricultural vehicle 10 on the ground. The vehicle 10 can travel in an
agricultural
field to perform agricultural work using a work implement 18. The vehicle 10
can also
be "roading", i.e., travelling on a road (i.e., a paved road having a hard
surface of
asphalt, concrete, gravel, or other pavement), such as between agricultural
fields.
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As will be further discussed later, in this embodiment, the track systems 161-
164 of
the agricultural vehicle 10 are designed to better perform when the vehicle 10
is
roading, including to reduce or minimize deteriorative effects on tracks of
the track
systems 161-164 (e.g., "blowout" of their tractiens projections, deterioration
of their
carcass, etc.) as the vehicle 10 travels fast against a road's hard surface.
Notably, in
this embodiment, each of the track systems 161-164 of the agricultural vehicle
10 is
designed to better laterally distribute a load it supports onto the road. This
may allow
the vehicle 10 to travel faster on the road without excessively wearing or
deteriorating the track systems 161-164, which may make the vehicle 10 more
efficient and productive.
The powertrain 15 is configured for generating motive power and transmitting
motive
power to the track systems 161-164 to propel the agricultural vehicle 10 on
the
ground. To that end, the powertrain 15 comprises a prime mover 14, which is a
source of motive power that comprises one or more motors. For example, in this
embodiment, the prime mover 14 comprises an internal combustion engine. In
other
embodiments, the prime mover 14 may comprise another type of motor (e.g., an
electric motor) or a combination of different types of motor (e.g., an
internal
combustion engine and an electric motor). The prime mover 14 is in a driving
relationship with the track systems 161-164. That is; the powertrain 15
transmits
motive power generated by the prime mover 14 to one or more of the track
systems
161-164 in order to drive (i.e., impart motion to) these one or more of the
track
systems 161-164 . The powertrain 15 may transmit power from the prime mover 14
to
the track systems 161-164 in any suitable way. In this embodiment, the
powertrain 15
comprises a transmission between the prime mover 14 and final drive axles 561,
562
for transmitting motive power from the prime mover 14 to the track systems 161-
164.
The transmission may be an automatic transmission (e.g., a continuously
variable
transmission (CVD) or any other suitable type of transmission.
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The work implOment 18 is used to perform agricultural work. For example, in
some
embodiments, the work implement 18 may be a combine head, a cutter, a scraper
pan, a tool bar, a planter, or any other type of agricultural work implement.
The operator cabin 20 is where the operator sits and controls the agricultural
vehicle
10. More particularly, the operator cabin 20 comprises a user Interface 70
including
a set of controls that allow the operator to steer the agricultural vehicle 10
on the
ground and operate the work implement 18. For example, in this embodiment, the
user interface 70 comprises an accelerator, a brake control, and a steering
device
.. that are operable by the operator to control motion of the agricultural
vehicle 10 on
the ground and operation of the work implement 18. The user interface 70 also
comprises an instrument panel (e.g., a dashboard) which provides indicators
(e.g., a
speedometer indicator, a tachometer indicator, etc.) to convey information to
the
operator.
The track systems 161-164 engage the ground to propel the agricultural vehicle
10.
As shown in Figures 2 and 3, each track system 16i comprises a track-engaging
assembly 21 and a track 22 disposed around the track-engaging assembly 21. In
this embodiment, the track-engaging assembly 21 comprises a plurality of
wheels
which, in this example, includes a drive wheel 24 and a plurality of idler
wheels that
includes front (i.e., leading) idler wheels 231, 232, rear (i.e., trailing)
idler wheels 261,
262, and roller wheels 281-284. The track system 16; also comprises a frame 13
which supports various components of the track system 16i, including the idler
wheels 231, 232, 261, 262, 281-284. The track system 16; has a longitudinal
direction
and a first longitudinal end 57 and a second longitudinal end 59 that define a
length
of the track system 161 along a longitudinal axis 61 that defines the
longitudinal
direction of the track system 16i. The track system 16; has a widthwise
direction and
a width that is defined by a width W of the track 22. The track system 161
also has a
height direction that is normal to its longitudinal direction and its
widthwise direction.
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Each of the front ones of the track systems 161-164 is steerable by the
steering
system 17 of the agricultural vehicle 10 in response to input of the user at
the
steering device to change an orientation of that track system relative to the
frame 12
of the agricultural vehicle 10 in order to steer the agricultural vehicle 10
on the
ground. To that end, each of the front ones of the track systems 161-164 is
pivotable
about a steering axis 25 of the agricultural vehicle 10. An orientation of the
longitudinal axis 61 of each of the front ones of the track systems 161-164 is
thus
adjustable relative to. a longitudinal axis 97 of the agricultural vehicle 10.
The track 22 engages the ground to provide traction to the agricultural
vehicle 10. A
length of the track 22 allows the track 22 to be mounted around the track-
engaging
assembly 21. In view of its closed configuration without ends that allows it
to be
disposed and moved around the track-engaging assembly 21, the track 22 can be
referred to as an "endless" track. With additional reference to Figures 3 to
6, the
track 22 comprises an inner side 45, a ,ground-engaging outer side 47, and
lateral
edges 491, 492. The inner side 45 faces the wheels 231, 232, 24, 261, 262, 281-
284,
while the ground-engaging outer side 47 engages the ground. A top run 65 of
the
track 22 extends between the longitudinal ends 57, 59 of the track system 161
and
over the wheels 231, 232, 24, 261, 262, 281-284, while a bottom run 66 of the
track 22
extends between the longitudinal ends 57, 59 of the track system 161 and under
the
wheels 24. 232, 24, 261, 262, 281-284. The bottom run 66 of the track 22
defines an
area of contact 63 of the track 22 with the ground which generates traction
and
bears a majority of a load on the track system 161, and which will be referred
to as a
"contact patch" of the track 22 with the ground. The track 22 has a
longitudinal axis
19 whioh defines a longitudinal direction of the track 22 (i.e., a direction
generally
parallel to its longitudinal axis) and transversal directions of the track 22
(i.e.,
directions transverse to its longitudinal axis), including a widthwise -
direction of the
track 22 (i.e., a lateral direction generally perpendicular to its
longitudinal axis). The
track 22 has a thickness direction normal to its longitudinal and widthwise
directions.
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In this embodiment, the track 22 is relatively narrow. For instance, this may
be
helpful to allow the track 22 to fit between rows of crops such as to leave
the crops
undisturbed when the agricultural vehicle 10 traverses an agricultural field.
In turn,
this may allow the agricultural field to have a greater crop density. For
instance, in
some embodiments, a ratio of a width Wy of the agricultural vehicle 10
(measured
between laterally-outwardmost ones of the track systems 161-164) over the
width W
of the track 22 may be at least 5, in some cases at least 7, in some cases at
least
10, in some cases at least 12, and in some cases even more. For example, in
some
embodiments, the width W of the track 22 may no more than 30 inches, in some
cases no more than 25 inches, in some cases no more than 20 inches, in some
cases no more than 18 inches, in some cases no more than 16 inches, and in
some
cases even less (e.g., 14.5 inches). The width W of the track 22 may have any
other
suitable value in other embodiments.
The track 22 is elastomeric, i.e., comprises elastomeric material, to be
flexible
around the track-engaging assembly 21. The elastomeric material of the track
22
can include any polymeric material with suitable elasticity. In this
embodiment, the
elastomeric material of the track 22 includes rubber. Various rubber compounds
may
be used and, in some cases, different rubber compounds may be present in
different
areas of the track 22. In other embodiments, the elastomeric material of the
track 22
may include another elastomer in addition to or instead of rubber (e.g.,
polyurethane
elastomer).
More particularly, the track 22 comprises an endless body 36 underlying its
inner
side 45 and ground-engaging outer side 47. In view of its underlying nature,
the
body 36 will be referred to as a "carcass". The carcass 36 is elastomeric in
that it
comprises elastomeric material 38 which allows the carcass 36 to elastically
change
in shape and thus the track 22 to flex as it is in motion around the track-
engaging
assembly 21.
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In this embodiment, the carcass .36 comprises a plurality of reinforcements
embedded in its elastomeric material 38. These reinforcements can take on
various
forms.
For example, in this embodiment, the carcass 36 comprises a layer of
reinforcing
cables 371-37N that are adjacent to one another and extend generally in the
longitudinal direction of the track 22 to enhance strength in tension of the
track 22
along its longitudinal direction. In this case, each of the reinforcing cables
371-37m is.
a cord including a plurality of Strands (e.g., textile fibers or metallic
wires). In other
in cases, each of the reinforcing cables 371-37m may be another type of
cable and may.
be made of any material suitably flexible along the cable's longitudinal axis
(e.g.,
fibers or wires of metal, plastic or composite material).
As another example, in this embodiment, the carcass 36 comprises a layer of
.. reinforcing fabric. 43. The reinforcing fabric. 43 comprises thin pliable
material made
usually by weaving, felting, knitting,. interlacing, or otherwise crossing
natural or
synthetic elongated fabric elements, such as fibers, filaments, strands and/or
others,
such that some elongated fabric elements extend transversally to the
longitudinal
direction of the track 22 to have a reinforcing effect in a transversal
direction of the
track 22. For instance, the reinforcing fabric 43 may comprise a ply of
reinforcing.
woven fibers (e.g., nylon fibers or other synthetic fibers).
The carcass 36 may be molded into shape in a molding process during which the
rubber 38 is cured. For example, in this embodiment, a mold may be used to
consolidate layers of rubber providing the rubber 38 of the carcass 36, the
reinforcing cables 371-37m and the layer of reinforcing fabric 43.
The inner side 45 of the endless track 22 comprises an inner surface 55 of the
carcass 36 and a plurality of wheel-contacting projections 481-48N that
project from
the inner surface 55 and are positioned to contact at least some of the wheels
231,
232, 24, 261, 262, 281-284 to do at least one of driving ;(i.e., imparting
motion to) the
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track 22 and guiding the track 22. The wheel-contacting projections 481-48N
can be
referred to as "wheel-contacting lugs". Furthermore, since each of them is
used to do
at least one of driving the track 22 and guiding the track 22, the wheel-
contacting
lugs 481-48N can be referred to as "drive/guide projections" or "drive/guide
lugs'. In
some examples of implementation, a drive/guide lug 481 may interact with the
drive
wheel 24 to drive the track 22, in which case the drive/guide lug 48; is a
drive lug. In
other examples of implementation, a drive/guide lug 48; may interact with the
front
and rear idler wheels 231, 232, 261, 262 and/or the roller wheels 281-284 to
guide the
track 22 to maintain proper track alignment and prevent de-tracking without
being
io used to drive the track 22, in which case the drive/guide lug 48; is a
guide lug. In yet
other examples of implementation, a drive/guide lug 48; may both (i) interact
with the
drive wheel 24 to drive the track and (ii) interact with the idler wheels 231,
232, 261,
262 and/or the roller wheels 281-284 to guide the track 22 to maintain proper
track
alignment and prevent de-tracking, in which case the drive/guide lug 48; is
both a
drive lug and a guide lug.
In this embodiment, the drive/guide lugs 481-48N interact with the drive wheel
24 in
order to cause the track 22 to be driven, and also interact with the idler
wheels 231,
232, 261, 262 and the roller wheels 281-284 in order to guide the track 22 as
it is
driven by the drive wheel 24 to maintain proper track alignment and prevent de-
tracking. The drive/guide lugs 481-48N are thus used to both drive the track
22 and
guide the track 22 in this embodiment
In this example of implementation, the drive/guide lugs 481-48N are arranged
in a
single row disposed longitudinally along the inner side 45 of the track 22.
The
drive/guide lugs 481-48N may be arranged In other manners in other examples of
implementation (e.g., in a plurality of rows that are spaced apart along the
widthwise
direction of the track 22).
In this embodiment, each drive/guide lug 48; is an elastomeric drive/guide lug
in that
it comprises elastomeric material 67. The elastomeric material 67 can be any
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polymeric material with suitable elasticity. More particularly, in this
embodiment, the
elastomeric material 67 includes rubber. Various rubber compounds may be used
and, in some cases, different rubber compounds may be present in different
areas of
the drive/guide lug 48i. In other embodiments, the elastonneric material 67
may
include another elastomer in addition to or instead of rubber (e.g.,
polyurethane
elastomer). The drive/guide lugs 481-48N may be provided on the inner side 45
in
various ways. For example, in this embodiment, the drive/guide lugs 481-48N
are
provided on the inner side 45 by being molded with the carcass 36.
The ground-engaging outer side 47 comprises a ground-engaging outer surface 31
of the carcass 36 and a tread pattern 40 to enhance traction on the ground.
The
tread pattern 40 comprises a plurality of traction projections 581-58T
projecting from
the ground-engaging outer surface 31,, spaced apart in the longitudinal
direction of
the endless track 22 and engaging the ground to .enhance traction. The
traction
IS projections 581-58T may be referred to as "tread projections" or
"traction lugs".
The traction lugs 581-58T may have any suitable shape. In this embodiment,
each of
the traction lugs 581-58T has an elongated shape and is angled, i.e., defines
an
oblique angle e (i.e., an angle that is not .a right angle or a multiple of a
right angle),
relative to the longitudinal direction of the track 22. The traction lugs 581-
58T may
have various other shapes in other examples (e.g., curved shapes, shapes with
straight parts and curved parts, etc.).
As shown in Figure 8, each traction lug 58 has a periphery 69 which includes a
front
surface 801, a rear surface 802, two lateral surfaces 811, 812, and a top
surface 86.
The front surface 801 and the rear surface 802 are opposed to one another in
the
longitudinal direction of the track 22. The two lateral faces 811, 812 are
opposed to
one another in the widthwise direction of the track 22. In this embodiment,
the front
surface 801, the rear surface 802, and the lateral surfaces 811, 812 are
substantially
straight. The periphery 69 of the traction lug 58; may have any other shape in
other
embodiments (e.g., the front surface 801, the rear surface 802, and/or the
lateral
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surfaces 811, 812 may be curved). The traction lug 58; has a front-to-rear
dimension
Li. in the longitudinal direction of the track 22, a side-to-side dimension Lw
in the
widthwise direction of the track 22, and a height H in the thickness direction
of the
track 22.
In this embodiment, each traction lug 58i is an elastomeric traction lug in
that it
comprises elastomeric material 41. The elastomeric material 41 can be any
polymeric material with suitable elasticity. More particularly, in this
embodiment, the
elastomeric material 41 includes rubber. Various rubber compounds may be used
to and, in some cases, different rubber compounds may be present in
different areas of
the traction lug 58. In other embodiments, the elastomeric material 41 may
include
another elastomer in addition to or instead of rubber (e.g., polyurethane
elastomer).
The traction lugs 581-58i may be provided on the ground-engaging outer side 47
in
various ways. For example, in this embodiment, the traction lugs 581-58T are
provided on the ground-engaging outer side 47 by being molded with the carcass
36.
The track 22 may be constructed in various other manners in other embodiments.
For example, in some embodiments, the track 22 may have recesses or holes that
interact with the drive wheel 24 in order to cause the track 22 to be driven
(e.g., in
which case the drive/guide lugs 481-48N may be used only to guide the track 22
without being used to drive the track 22, i.e., they may be "guide lugs"
only), and/or
the ground-engaging outer side 47 of the track 22 may comprise various
patterns of
traction lugs.
The drive wheel 24 is rotatable by power derived from the prime mover 14 to
drive
the track 22. That is, power generated by the prime mover 14 and delivered
over the
powertrain 15 of the agricultural vehicle 10 can rotate a final drive axle
561, which
causes rotation of the drive wheel 24, which in turn imparts motion to the
track 22.
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With additional reference to Figure 9, in this embodiment, the drive wheel 24
comprises a drive sprocket comprising a .plurality of drive members 521-52B
spaced
apart along a circular path to engage the drive/guide lugs 481-48N of the
track 22 in
order to drive the track 22. The drive wheel 24 and the track 22 thus
implement a
"positive drive" arrangement. More particularly, in this embodiment, the drive
wheel
24 comprises two side discs 501, 502 which are co-centric and turn about a
common
axle 51 and between which the drive members 521-52B extend near respective
peripheries of the side discs 501, 502. In this example, the drive members 521-
52s
are thus drive bars.that extend between the side discs 501, 502. The drive
wheel 24
to and the track 22 have respective dimensions allowing interlocking of the
drive bars
521-528 of the drive wheel 24 and the drive/guide lugs 481-48N of the track
22.
Adjacent ones of the drive bars 521-523 define an interior space 53 between
them to
receive one of the drive/guide lugs 481-48N. Adjacent ones of the drive/guide
lugs
481-48N define an inter-lug space 39 between them to receive one of the drive
bars
521-52B. The drive/guide lugs 481-48N and the drive bars 521-523 have a
regular
spacing that allows interlocking of the drive/guide lugs 481-48N and the drive
bars
521-523 over a certain length of the drive wheel's circumference.
The drive wheel 24 may be configured in various other ways in other
embodiments.
zo For example, in other embodiments, the drive wheel 24 may not have any
side discs
such as the side discs 501, 502. As another example, in other embodiments,
instead
of being drive bars, the drive members 521-528 may be drive teeth that are
distributed circumferentially along the drive wheel 24 or any other type of
drive
members. As another example, in embodiments where the track 22 comprises
recesses or holes, the drive wheel 24 may have teeth that enter these recesses
or
holes in order to drive the track 22. As yet another example, in some
embodiments,
the drive wheel 24 may frictionally engage the inner side 45 of the track 22
in order
to frictionally drive the track 22 (i.e., the drive wheel 24 and the track 22
may
implement a 'friction drive" arrangement).
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The idler wheels 231, 232, 261, 262, 281-284 are not driven by power supplied
by the
prime mover 14, but .are rather used to do at least one .of supporting part of
the
weight of the agricultural vehicle 10 on the ground via the track 22, guiding
the track
22 as it is driven by the drive wheel 24, and tensioning the track 22. More
particularly, in this embodiment, the front and rear 'idler wheels 231, 232,
261, 262
maintain the track 22 in tension and help to support part of the weight of the
agricultural vehicle 10 on the ground via the track 22. As shown in Figure 10,
the
roller wheels 281-284 roll on a rolling path 33 of the inner -side 45 of the
track 22
along the bottom run 66 of the track 22 to apply the bottom nin 66 on the
ground. In
this case, as they are located between frontmost and rearmost ones of the
wheels of
the track system 163, the roller wheels 281-284. can be referred to as "mid-
rollers".
With additional reference to Figures 11 to 15, each mid-roller 28; comprises a
hub
portion 73, a rim portion 74, and .a radially-extending portion 34 between the
hub
portion 73 and the rim portion 74. The hub portion 73 is an inner portion of
the mid-
roller 28; which is associated with a hub 75 receiving an axle 76 for the mid-
roller 28i.
The rim portion 74 is an outer portion of the mid-roller 28; which contacts
the inner
side 45 of the endless track 22. The radially-extending portion 34 is an
intermediate
portion of the mid-roller 28; which extends radially between the hub portion
73 and
.20 the rim portion 74.
The mid-roller 281 comprises a pair of lateral sides 301, 302 opposite one
another and
a peripheral side 32 between, the lateral sides 301, 302. The peripheral side
32 rolls
on the inner side 45 of the track 22 to apply the bottom run 66 of track 22 on
the
ground. More particularly, in this embodiment, the mid-roller 28; rolls on.
the rolling
path 33 which is delimited by some of the drive/guide lugs 481-48N such that,
as the
mid-roller 28; rolls, these drive/guide lugs pass next to the mid-roller 28i.
In this embodiment, the mid-roller 284 may engage a significant extent of the
width W
of the track 22. For example, in. some embodiments, a ratio of a width Rõ of
the mid-
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roller 28; over the width W of the track 22 may be at least 0.2, in some cases
at least
0.3, in some cases at least 0.4, and in some cases even more.
In addition, in this embodiment, as shown in Figures 16 and 17, the track
system 16;
comprises a wheel-mounting subassembly 85 which may be referred to as a
"bogie".
The bogie 85 is configured to carry the mid-rollers 281-284 and is mounted to
the
frame 13 of the track system 16. More specifically, the bogie 85 comprises a
link 89
to which are mounted the mid-rollers 281-284. The bogie 85 is pivotable
relative to
the frame 13 of the track system 16; about a pivot 87 defining an axis of
rotation 88
.. that is perpendicular to the longitudinal axis 61 of the track system 16.
The bogie 85
thus imparts the mid-rollers 281-284 with a pivoting motion capability which
may be
referred to as a "pitch" motion. The mid-rollers 281-284 may not be mounted to
a
bogie in other embodiments. For example, the mid-rollers 281-284 may be
mounted
directly to the frame 13 of the track system 16; in other embodiments.
Moreover, as shown in Figure 16, the track system 16; may comprise a
tensioning
mechanism 95 for tensioning the track 22. For instance, in this embodiment,
the
tensioning mechanism 95 comprises an actuator mounted at one end to the frame
13 of the track system 161 and at another end to a hub of the front idler
wheels 231,
232. This allows the tensioning mechanism 95 to modify a distance between the
front
idler wheels 231, 232 and the rear idler wheels 261, 262 in the longitudinal
direction of
the track system 16.
With additional reference to Figure 19, in this embodiment, each track system
16; is
.. designed to better perform when the agricultural vehicle 10 is roading,
i.e., travelling
on a road 115, such as between agricultural fields, notably by reducing or
minimizing
deteriorative effects on its track 22 (e.g., "blowout" of the traction
projections 581-58-r
of the track 22, deterioration of the carcass 36 of the track 22, etc.) as the
vehicle 10
travels fast against a hard surface S (e.g., asphalt, concrete, gravel, or
other
pavement) of the road 115, thereby making the vehicle 10 more efficient and
productive.
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This capability of the track system 16; to better perform on the road 115 may
be
particularly useful in situations such as this example in which the road's
surface S
has a cross slope for leading water away from the road 115 (i.e., to avoid
water
accumulation on the road 115). In this case, the cross slope of the road's
surface S
is such that the road 115 has a crown 117, i.e., a highest point, at a center
of the
road 115 in its widthwise direction and slopes downwardly on either side of
the
crown 117. For instance, in some cases, an angle a defined between a
horizontal
axis and the road's surface S on either side of the crown 117 may be at least
1 , in
some cases at least 2 , in some cases at least 4 , and in some cases even
higher
(e.g., at least 6 or 8 ). The angle a may have any other value in other
cases. In
view of its crown 117, the road 115 may sometimes be referred to as a "crowned
road".
In this embodiment, the track system 16; may be configured to accommodate a
shape of the road 115, including its crown 117 in this example, so as to
better
distribute loading on its track 22 than a conventional track system. For
example, with
additional reference to Figure 18, an agricultural vehicle 800 equipped with
conventional track systems 8161-8164 may perform poorly while travelling on
the
crowned road 115. Notably, a track 822 of a track system 816; may have a
lateral
extent of its contact patch 863 with the crowned road 115 that is
significantly
reduced. This can adversely affect traction of the track 822 on the road 115,
but,
more importantly, generates significant loads on the track 822 that result in
severe
stress regions which can accelerate wear and deterioration of the track 822
and lead
to premature failure of the track 822. This problem may be amplified when the
agricultural vehicle 800 Is roading at elevated speeds.
The track system 16; may have various features to better perform when the
agricultural vehicle 10 is travelling on the road 115. Examples of these
"enhanced-
so features" are discussed below.
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1. Lateral load distribution mechanism
In some embodiments, with additional reference to Figure 19, the track system
161
may comprise a lateral load distribution mechanism 100 configured to increase
a
lateral extent C of the contact patch 63 of the track 22 when the agricultural
vehicle
travels on the crowned road 11. This may reduce peak loads experienced by the
track 22 and thus help to reduce potential for rapid wear or other
deterioration of the
track 22 as the vehicle 10 travels on the road's hard surface S, particularly
at high
speed.
In this embodiment, the lateral load distribution mechanism 100 is configured
to
apply the idler wheels 231, 232, 261, 262, 281-284 onto the bottom run 66 of
the track
22 such as to increase the lateral extent C of the contact patch 63 of the
track 22
when the agricultural vehicle 10 is travelling on the road's surface S which
has the
cross slope in a direction normal to a direction of travel of the agricultural
vehicle 10.
For example, in some embodiments, the lateral load distribution mechanism 100
may be configured to apply laterally-adjacent ones of the idler wheels 231,
232, 261,
262, 281-284 onto the bottom run 66 of the track 22 to increase the lateral
extent C of
the contact patch 63 of the track 22. The laterally-adjacent ones of the idler
wheels
231, 232, 261, 262, 281-284 are respective ones of these wheels that are
generally
aligned with respect to one another or otherwise closest to one another in the
longitudinal direction of the track system 161 (e.g., the front idler wheels
231, 232,
and/or the rear idler wheels 261, 262, and/or the mid-rollers 281, 283, and/or
the mid-
rollers 282, 284.
26
The lateral load distribution mechanism 100 may be configured such that bottom
track-contacting areas 146 of laterally-adjacent ones of the idler wheels 231,
232,
261, 262, 281-284 are vertically movable relative to one another (i.e.,
movable relative
to one another in the height direction of the track system 160. The bottom
track-
contacting area 146 of a given one of the idler wheeis 231, 232, 261, 262, 281-
284 is
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that area of the given one of the idler wheels 231, 232, 261, 262, 281-284
which
contacts the bottom run 65 of the track 22.
For instance, in this embodiment, the lateral load distribution mechanism 100
may
increase the lateral extent C of the contact patch 63 of the track 22 when the
agricultural vehicle 10 travels on the crowned road 115 such that a ratio of
the lateral
extent C of the contact patch 63 of the track 22 over the width W of the track
22 is at
least 0.3, in some cases at least 0.4, in some cases at least 0.5, in some
cases at
least 0.6, and in some cases even more (e.g., at least 0.8). In some cases,
the
lateral load distribution mechanism 100 may cause the lateral extent C of the
contact
patch 63 to correspond to an entirety of the width W of the track 22.
As a result of the increased lateral extent C of the contact patch 63 of the
track 22
provided by the lateral load distribution mechanism 100, a peak load exerted
on the
track 22 on the road 115 may be reduced. For instance, in some embodiments, a
ratio of the peak load exerted on the track 22 over a load on the track system
161 on
the road 115 (i.e., calculated by dividing the weight of the vehicle 10 by the
number
of track systems 161-164) may be no more than a certain value. I. For example,
in
some embodiments, the peak load exerted on the track 22 on the road 115 may be
no more than a certain value.
The lateral load distribution mechanism 100 may be implemented in various
ways,
certain examples Of which will be described below.
1.1 Idler wheel roll motion
In some embodiments, the lateral load distribution mechanism 100 may allow a
"roll"
motion of respective ones of the front and rear idler wheels 231, 232, 261,
262 and/or
the mid-rollers 281-284. That is, the lateral load distribution mechanism 100
may be
configured to allow a motion of respective ones of the front and rear idler
wheels
231, 232, 261, 262 and/or the mid-rollers 281-284 relative to the frame 12 of
the
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agricultural vehicle 10 that includes a rotation about a roll axis 164 which
Is
transverse to their axes of rotation, in this case, parallel to the
longitudinal axis 61 of
the track system 161.
For example, in some embodiments, the roll motion enabled by the lateral load
distribution mechanism 100 may be implemented by the bogie 85. More
specifically,
the bogie 85 may be movable relative to the frame 12=of the vehicle 10 to
cause the
front and, rear idler wheels 231, 232, 261, 262 and/or the mid-rollers 281-284
to rotate
about the roll axis 164 as they engage the bottom tun 66 of the track 22 when
the
agricultural vehicle 10 travels on the crowned road 115.
More particularly, in some embodiments, as shown in Figure 31, the bogie 85 is
configured to define the roll motion and a "pitch" motion of respective ones
of the
mid-rollers 281-284. That is, the bogie 85 can define a rotation about the
roll axis 164
parallel to the longitudinal axis 61 of the track system 161 and about.a pitch
axis 174
parallel to the widthwise direction of the track system 16.
As shown in Figures 32 and 33, in this embodiment, the bogie 85 comprises an
upper structure 152 and a lower structure 154 connected to the upper structure
154.
The lower structure 154 is configured to provide the bogie 85 with its roll
motion
capability. The lower structure 154 comprises a pair of axle-retaining members
156,
1562 spaced apart in the longitudinal direction of the track system 161, and a
roll
motion mechanism 158 connecting the axle-retaining members 1561, 1562 to one
another. The axle-retaining members 1561, 1562 are configured to receive the
axles
76 of the mid-rollers 281-284 (e.g., via a hole traversing each axle-retaining
member
1561). Each axle 76 receives two laterally adjacent mid-rollers 286 28
thereon.
The roll motion mechanism 158 comprises a shaft 160 and an outer tube 162
receiving the shaft 160 therein. The shaft 160 extends in the longitudinal
direction of
the track system 1.6i and is connectable to the axle-retaining members 1561,
1562.
For example, the shaft 160 may be connected to the axle-retaining members
1561,
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1562 via an interference fit. In other embodiments, the shaft 160 may be
connected
to the axle-retaining members 1561, 1562 in any other suitable way (e.g., via
welding,
fasteners, etc.). The outer tube 162 is mounted to the shaft 160 and extends
between the axle-retaining members 1561, 1562. The shaft 160 is rotatable
within the
outer tube 162 about an axis of rotation of the outer tube 162 which
corresponds to
the roll axis 164. In this embodiment, the shaft 160 rotates within the outer
tube 162
via a bearing 166 (e.g., a roller bearing) disposed between a peripheral
surface of
the shaft 160 and an inner surface of the outer tube 162. The shaft 160 may
rotate
within the outer tube 162 via any other suitable mechanism in other
embodiments.
The upper structure 152 of the bogie 85 is configured to provide the bogie 85
with its
pitch motion capability. The upper structure 152 comprises a body 168 affixed
to the
_ _
lower structure 154 (e.g., via welding). The body 168 comprises a shaft-
receiving
aperture 170 for receiving therein a shaft 172. The shaft 172 is rotatable
within the
shaft-receiving aperture 170 about an axis of rotation that corresponds to the
pitch
axis 174. For example, the shaft-receiving aperture 170 may comprise a bearing
176
(e.g., a roller bearing) for enabling rotation of the shaft 172 within the
shaft-receiving
aperture 170. As shown in Figure 33, the shaft 170 is connected at its
longitudinal
end portions to the frame 13 of the track system 16 which supports the bogie
85.
Thus, in this embodiment, the lateral load distribution mechanism 100 allows
the
bogie 85 to define the roll motion and the pitch motion about the roll and
pitch axes
164, 174 respectively. Therefore, when the agricultural vehicle 10 travels on
the
crowned road 115, the bogie 85 allows the mid-rollers 281-284 to pivot about
the roll
axis 164 causing the mid-rollers 281-284 to apply the bottom run 66 of the
track 22
more evenly on the hard surface S of the crowned road 115.
The roll motion of respective ones of the front and rear idler wheels 231,
232, 261,
262 and/or the mid-rollers 281-284 may be implemented by the lateral load
distribution mechanism 100 in any other suitable way in other embodiments.
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1.2 Adaptable idler wheel suspension
In some embodiments, the lateral load distribution mechanism 100 may implement
an adaptable suspension of respective ones of the idler wheels 231, 232, 261,
262,
281-284. For instance, the lateral load distribution mechanism 100 may cause a
suspension of the front and rear idler wheels 231, 232, 261, 262 and/or a
suspension
of the mid-rollers 281-284 to increase the lateral extent C of the contact
patch 63 of
the track 22 when the agricultural vehicle 10 travels on the crowned road 115.
For example, in some embodiment, as shown in Figure 20, the lateral load
distribution mechanism 100 may comprise a suspension of laterally-adjacent mid-
rollers 28, 28j which comprises axles 1101, 1102 that are moveable with
respect to
one another and about which the mid-rollers 28, 28j are rotatable. For
example,
each axle 110 may be received within the hub 76 (shown in Figure 15) which
rotates
relative to the axle 110; about an axis of rotation 116. The suspension of the
lateral
load distribution mechanism 100 thus effectively implements an independent
suspension for the laterally-adjacent mid-rollers 28, 281 that allows them to
move
independently from one another in the height direction of the track system.
zo In this example, the suspension of the lateral load distribution
mechanism 100 also
comprises a resilient member 111 mounted between the axles 1101, 1102, and a
frame 114. The resilient member 111 is configured to change in configuration
from a
first configuration to a second configuration in response to a load and
recover the
first configuration in response to removal of the load in order to allow
relative
movement of the axles 1101, 1102. In this embodiment, the resilient member 111
comprises a pair of resilient elements 1121, 1122. Each resilient element 1121
is
mounted at one end to the axle 110; and at another end to the frame 114 in
order to
allow the axle 1101 to move relative to the frame 114 in the height direction
of the
track system 16. The resilient member 112 comprises a spring 113. The spring
113
may be a coil spring, a torsion spring, a leaf spring, an elastomeric spring
(e.g., a
rubber spring), a fluid spring (e.g., an air spring), or any other object that
is operable
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to change in configuration from a first configuration to a second
configuration in
response to a load and recover the first configuration in response to removal
of the
load.
As shown in Figures 22 and 23, the frame 114 is configured to support the axle
110;
and to bound its motion. For instance, in this embodiment, the frame 114
comprises
= a slot 118 generally extending in the height direction of the track
system 16; and
along which the axle 110; is movable. In this embodiment, the frame 114 is a
part of
the bogie 85. In other embodiments, the frame 114 may be part of the frame 13
of
lo the track system 16.
Thus, each resilient element 112 exerts a downward force on a corresponding
axle
110; to cause the corresponding. mid-roller 28; to apply the bottom run 66 of
the track
22 onto the ground. Moreover, motion of the axle 110; is limited both in the
height
direction and in the longitudinal direction of the track system 16; by the
frame 114.
Therefore, when the agricultural vehicle 10 travels on the crowned road 115,
as
illustrated in Figure 21, the lateral load distribution system 100 causes the
mid-roller
28; that is at a lowest section of the road to be moved lower in the height
direction of
the track system 16i while the other mid-roller 28i that is at a highest
section of the
road is moved higher in the height direction of the track system 16. This may
help to
more evenly apply the bottom run 66 of the track 22 onto the hard surface S of
the
crowned road 116 such as to increase the lateral extent C of the contact patch
63 of
the track 22.
Although the lateral load distribution mechanism 100 has been described in
respect
of laterally-adjacent mid-rollers 281, 28, a similar system may be applied to
other
laterally-adjacent idler wheels such as the front idler wheels 231, 232 and
the rear
idler wheels 261, 262. For example, the front idler wheels 23,, 232 may rotate
about
separate axles that are adaptabty supported by the frame 13 of the track
system 16;
such that a height of each separate axle is varied when the agricultural
vehicle 10
travels on the crowned road '115.
=
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The suspension of respective ones of the idler wheels 231, 232, 251, 262, 281-
284
may be implemented by the lateral load distribution mechanism 100 in any other
suitable way in other embodiments.
1.3 Articulated idler wheel axle
In some embodiments, the lateral load distribution mechanism 100 may implement
an articulated axle of one or more of the idler wheels 231, 232, 261, 262, 281-
284 that
to causes the front and rear idler wheels 231, 232, 261, 262 and/or the mid-
rollers 2E3.'-
284 to engage the track 22 in order to increase the lateral extent C of the
contact
patch 63 of the track 22 when the agricultural vehicle 10 travels on the
crowned
road's surface S.
For example, in some embodiments, as shown in. Figures 24 to 27, the lateral
load
distribution mechanism 100 may comprise articulated axles 1191, 1192 for
laterally-
adjacent mid-rollers 286 28j. Each articulated axle 110w comprises an
articulation
124 between sections 121i, 1212 .of the articulated axle 119; to allow the
sections
1211, 1212 of the articulated axle 119. to move relative to one another to
accommodate the crowned road's surface S.
In this embodiment, the articulated axles 1191, 1192 are part of a common axle
120.
The outboard section 1211 of each articulated axle 119w comprises a spindle
122
leading to the mid-rollers 28 while the inboard section 1212 of the
articulated axle
119õ comprises a central portion 123 of the common axle 120. The articulation
124x
constitutes a joint between the spindle 122 and the central portion 123 of the
common axle 120. In other embodiments, the articulated axles 1191. 1192 may be
separate from one another (I.e., not part of any common axle).
More particularly, in this embodiment, the common axle 120 comprises a shaft
extending along a longitudinal axis 125 (generally parallel to the widthwise
direction
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of the track system 160 and mounted to a frame 126. In this example, the frame
126
is part of the bogie 85. However, in other examples, the frame 126 may be a
part of
the frame 13 of the track system 16i. The central portion 123, of the common
axle
120 comprises a first connecting portion 128 at each end portion of the
central
portion 123. In this embodiment, the first connecting portion 128 comprises a
forked
connector including two prongs extending along the longitudinal axis 125.
The spindle 122 of each articulated axle 119x is configured for mounting a
respective
mid-roller 28; and comprises a shaft extending along a longitudinal axis 127
of tile
in .. spindle 122. For example, the mid-roller 28; may be mounted to the
spindle 122 via
the hub 75 as previously described and illustrated in Figure 1,5. The spindle
122
comprises a second connecting portion 130 at a longitudinal end thereof. The
second connecting 130 of the spindle 122 is complimentary to the first
connecting
portion 128 of the central portion 123 of the common axle 120. For example, in
this
embodiment, the second connecting portion 130 comprises a single-pronged
connector extending in a longitudinal direction of the spindle 122.
The articulation 124õ allows the Spindle 122 to move relative to the central
portion
123 of the common axle 120 such that the longitudinal axis 127 of the spindle
122 is
movable relative to the longitudinal axis 125 of the common axle 120. More
specifically, the articulation 124, defines an axis of rotation 132 about
which the
spindle 122 is rotatable. The axis of rotation 132 of the articulation 124x is
defined by
a rotation member 134 which rotator* connects the first and second connecting
portions 128, 130 to one another. In this embodiment, the rotation member 134
comprises a dowel pin which may be secured to the first and second connecting
portions 128, 130 in any suitable way (e.g., via cotter pins).
In this embodiment, the articulation 124õ further comprises a resilient
element 136
for biasing the spindle 122 to rotate about the axis of rotation 132 in a
particular
direction. More specifically, the resilient element 136 Urges the spindle 122
to rotate
downwardly (i.e., towards the bottom run 66 of the track 22). The resilient
element
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136 comprises a spring 137. In this embodiment, the spring 137 comprises a
torsion
spring. The spring 137 may be a coil spring, a leaf spring, an elastomeric
spring
(e.g., a rubber spring), a fluid spring (e.g., an air spring), or any other
object that is
operable to change in configuration from a first configuration to a second
configuration in response to a load and recover the first configuration in
response to
removal of the load in other embodiments.
In some embodiments, the resilient element 136 may be omitted as the Weight of
the
mid-roller 28; may be sufficient to cause the spindle 122 to rotate
downwardly.
io
In use, as shown in Figures 24 and 27, when the agricultural vehicle 10
travels on
the crowned road 115, the lateral load distribution mechanism 100 causes the
spindle 122 that is at a lowest section of the road 115 to be rotated
downwardly (i.e.,
towards the bottom run 66 of the track 22) and the spindle 122 that is at a
highest
section of the road 115 to be rotated upwardly (i.e., towards the upper run 65
of the
track 22). As a result, the mid-roller 28; that is at the lowest section of
the road 115 is
moved lower in the height direction of the track system 16 while the other mid-
roller
281 that is at the highest section of the road115 is moved higher in the
height
direction of the track system 16. This may more evenly apply the bottom run 66
of
the track 22 onto the hard surface S of the crowned road 115 such as to
increase
the lateral extent C of the contact patch 63 of the track 22.
Although the lateral load distribution mechanism 100 has been described in
respect
of laterally adjacent mid-rollers 286 28j, a similar system may be applied to
other
laterally-adjacent idler wheels such as the front idler wheels 231, 232 and
the rear
idler wheels 26,, 262.
The articulated axles of respective ones of the idler wheels 23,, 232, 26,,
262, 28,-
284 may be implemented by the lateral load distribution mechanism 100 in any
other
suitable way in other embodiments (e.g., a spherical joint, a universal joint,
etc.).
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1.4 Deformable idler wheels
In some embodiments, the lateral load distribution mechanism 100 may be
implemented by deformation (i.e., change in configuration) of one or more of
the
idler wheels 231, 232, 261, 262, 281-284. For instance, as shown in Figure 28,
the
lateral load distribution system 100 may allow deformation of the front and
rear idler
wheels 231, 232, 261, 262 and/or the mid-rollers 281-284 to engage the track
22 to
minimize a decrease in the lateral extent C of the contact patch 63 of the
track 22
- when the agricultural vehicle 10 travels over the crowned road surface S.
More particularly, the lateral load distribution mechanism 100 may allow the
front
and rear idler wheels 231, 232, 261, 262 and/or the mid-rollers 281-284 to
deform from
a first configuration to a second configuration to cause the bottom run 66 of
the track
22 to be applied onto the ground when the agricultural vehicle 10 travels over
the
crowned road surface S.
For example, in some embodiments, as shown in Figure 29, each mid-roller 28;
may
comprise a wheel body 60 and a covering 62 (e.g., a tire) disposed over the
wheel
body 60.
The wheel body 60 is a core of the mid-roller 28; that imparts structural
integrity to
the mid-roller 28g. The wheel body 60 has a pair of lateral sides opposite one
another
and a peripheral side 77 between the lateral sides. In this case, the lateral
sides of
the wheel body 60 form part of the lateral sides 301, 302 of the mid-roller
286 while
the peripheral side 65 of the wheel body 60 is covered by the covering 62. The
wheel body 60 defines an internal space 68 delimited by internal surfaces of
the
wheel body 60. The internal space 68 includes an internal circumferential
channel 66
which is defined by a shoulder 71 of the wheel body 60. Moreover, the wheel
body
60 comprises an opening 72 that is accessible from the internal space 68 of
the
wheel body 60 and grants access to the deformable member 64.
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In this case, the hub 75 is removably mounted to the wheel body 60. More
particularly, in this case, a hub portion of the wheel body 60, corresponding
to the
hub portion 73 of the mid-roller 281, comprises a plurality of openings in
which are
received a plurality of fasteners that interconnect the wheel body 60 to the
hub 75.
The hub portion of the wheel body 60 may be configured in various other ways
in
other embodiments (e.g., the hub 75 may be integrally formed (e.g., cast) with
or
permanently affixed (e.g., welded) to the hub portion of the wheel body 60).
The wheel body 60 is made of at least one material, referred to as "wheel body
material". That is, the wheel body 60 comprises one or more wheel body
materials
making up the wheel body 60. In some cases, the wheel body 60 may comprise a
single wheel body material making up an entirety of the wheel body 60. In
other
cases, the wheel body 60 may comprise two or more wheel body materials that
make up different parts of the wheel body 60.
In this embodiment, the wheel body 60 is a metallic wheel body. The wheel body
60
is metallic in that it is at least mainly (i.e., it is mostly or entirely)
made of a metallic
material. The metallic material is selected to provide strength and rigidity
to the mid-
roller 28. For example, in this case, the metallic material comprises steel.
In other
case's, the metallic material may comprise another metal instead of steel. In
other
embodiments, the wheel body 60 may be at least mainly made of another type of
material (e.g., composite material, polymeric material, or ceramic material).
Also, in
other embodiments, different parts of the wheel body 60 may be made of two or
more wheel body materials (e.g., two types of steel).
The covering 62 contacts the inner side 45 of the endless track 22 as the mid-
roller
28; rolls on the inner side 45 of the track 22. In this embodiment, the
covering 62
forms at least part of the peripheral side 32 and at least part of at least
one of the
lateral sides 301, 302 of the mid-roller 28. More particularly, in this
embodiment, the
covering 62 comprises a peripheral portion 78 that forms the peripheral side
32 of
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=
the mid-roller 28; and a lateral portion 82 that forms part of the lateral
side 302 of the
mid-roller 28i which faces a drive/guide lug 48i.
The covering 62 covers at least part of the wheel body 60 of the mid-roller
28. In this
.. embodiment, the covering 62 covers the peripheral side 77 of the wheel body
60 and
part of a lateral side of the wheel body 60. Notably, the covering 62 covers
at least
part, in this case all, of an external surface of the shoulder 76 of the wheel
body 60.
The covering 62 is made of at least one material, referred to as a 'covering
material". That is, the covering 62 comprises one or more covering materials
making
up the covering 62. In some cases, the covering 62 may comprise a single
covering
material making up an entirety of the covering 62. In other cases, the
covering 62
may comprise two or more covering materials that make up different parts of
the
covering 62.
The covering material of the covering 62 is different from a wheel body
material of
the wheel body 60. That is, the covering material and the wheel body material
may
belong to different classes of materials (i.e., metals, polymers, ceramics and
composites) and/or may substantially differ in terms of one or more
properties, such
as strength, elasticity, hardness, friction coefficient, etc. For instance, in
some cases:
a strength (e.g., yield strength) of the wheel body material may be different
from
(e.g., greater than) a strength of the covering material; a modulus of
elasticity of the
covering material may be different from (e.g., less than) a modulus of
elasticity of the
wheel body material; an abrasion resistance of the covering material may be
different from (e.g., greater than) an abrasion resistance of the wheel body
material;
a coefficient of friction of the covering material with the track 22 may be
different
from (e.g., less than) a coefficient of friction of the wheel body material
with the track
22; etc.
In this embodiment, the modulus of elasticity of the covering material of the
wheel
covering 62 is substantially lower than a. modulus of elasticity of the
elastomeric
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=
material of the track 22. For instance, a ratio of the modulus of elasticity
of the
covering material over the modulus of elasticity of the elastomeric material
of the
track 22 may be at most 0.6, in some cases at most 0.5, in some cases at most
0.4,
in some cases at most 0.3, and in some cases even less.
As shown in Figure 29, when the agricultural vehicle 10 travels over a
substantially
flat terrain, the mid-roller 28; assumes its first configuration in which the
peripheral
portion 78 of the covering 62 is substantially parallel to the peripheral side
77 of the
wheel body 60.
As shown in Figure 30, when the agricultural vehicle 10 travels over the
crowned
road surface S, the mid-roller 28; assumes its second configuration. More
specifically, the covering 62 of the mid-roller 281 deforms such that a lower
portion of
its peripheral portion 78 is transverse (i.e., nonparallel) to the peripheral
side 77 of
the wheel body 60. Thus, the peripheral portion 78 of the covering 62 defines
an
angle p between an outer surface of its peripheral portion 78 and an outer
surface of
the peripheral side 77 of the wheel body 60. For instance, the angle p may be
at
least 1 , in some cases at least 2 , in some cases at least 3 , in some cases
at least
4 , in some cases at least 5 , and in some cases even greater (e.g., 6 ). For
example, in some cases, the angle p may be equal to the angle a defined by the
sloped surface S of the crowned road 115.
Thus, in use, when the agricultural vehicle 10 travels over the crowned road
115, the
covering 62 of the mid-roller 28; elastically deforms such that the lower
portion of the
peripheral portion 78 (i.e., the portion in contact with the bottom run 66 of
the track
22) defines the angle p relative to the peripheral side 77 of the wheel body
60. This
may minimize a reduction in the lateral extent C of the contackpatch 63 of the
track
22 that would otherwise occur if the lateral load distribution mechanism 100
were not
implemented.
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=
=
Although the lateral load distribution mechanism 100. has been described in
respect
of laterally adjacent mid-rollers 281, 28, a similar system may be applied to
other
laterally adjacent idler wheels such as the front idler wheels 231, 232 and
the rear
idler wheels 261, 262.
The deformation of one or more of the idler wheels 231, 232, 261, 262, 281-284
allowed by the lateral load distribution mechanism 100 may be implemented in
any
other suitable way in other embodiments (e.g., the covering 62 may comprise a
'balloon" tire (i.e., a. low-pressure tire) or a bladder containing a fluid
that can deform
to accommodate the crowned road's hard surface S).
2. VVider and/or shorter traction lugs
In some embodiments, the track 22 of the track system 161 may be configured to
be
more resistant to wear as the agricultural vehicle 10 is roading. For
instance, in
some embodiments, the tread pattern. 40 of the track 22 may be more resistant
to
wear or other deterioration as the agricultural vehicle 10 travels on the
road's hard
surface S. Notably, the tread pattern 40 of the track 22 may be designed to
reduce
potential for blowout of the traction lugs 581-581- by reducing heat buildup
within the
track 22. -
To that end, in some embodiments, as shown in Figures 34 and 35, the traction
lugs
581-58T may be dimensioned to reduce potential for heat buildup within them
and to
facilitate their internal heat dissipation. For example, a ground-contacting
area of
each traction lug 58 may be increased and/or the height H of the traction lug
58 may
be decreased in order to reduce deformation of the traction projection 581 as
it
repeatedly contacts the road's hard surface S as the agricultural vehicle 10
is
roading. Increasing the ground-contacting area of the. traction lug 58i
distributes
loading on the traction lug 58i over a larger space and may thus reduce stress
and
strain of the traction lug 58i. Decreasing the height H of the traction lug
58; may also
help to reduce deflection of the traction lug 581. This reduced deformation,
of the
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tractiOn lug 58; as it frequently engages the road's surface S while the
vehicle 10 is
roading may help to reduce heat buildup within the traction lug 584 thus
reducing
potential for blowout of the traction lug 581. In other words, by "flattening"
the traction
lug 584 it may deform less and thus be less susceptible to blowout
For example, in some embodiments, the width Lw of the traction lug 58; may be
greater than that of conventional tracks. For instance, the width Lw of the
top surface
86 of the traction lug 58i may be increased in relation to the width W of the
track 22.
For instance, a ratio of the width Lw of the traction lug 581 over the width W
of the
track 22 may be at least 0.5, in some cases at least 0.6, in some cases at
least 0.7,
and in some cases even more. The ratio of the width Lw of the traction lug 58i
over
the width W of the track 22 may have any other suitable value in other
embodiments.
In some embodiments, a width TS of the top surface 86 of the traction lug 58i
may
be significantly greater than that of conventional tracks. For instance, the
width TS of
the top surface 86 of the traction lug 58i may be increased in relation to the
width W
of the track 22. For example, a ratio of the width TS of the top surface 86 Of
the
traction lug 58; over the width W of the track 22 may be at least. 0.1, in
some cases
at least 0.15, in some cases at least 0.2, and in some cases even inure. The
ratio of
the width TS of the top surface 86 of the traction lug 58; over the width W of
the track
22 may have any other suitable value in other embodiments.
Furthermore, the height H of the traction lug 581 may be considerably smaller
than
that of conventional tracks. For instance,, a ratio of the height H of the
traction lug 58;
over the thickness Tc of the carcass 36 may be no more than 1.2, in some cases
no
more than 1.15, in some cases no more than 1.1, in some cases no more than
1.05,
and in some cases even less. The ratio of the height H of the traction lug 58;
over
the thickness Tc of the carcass 36 may have any other suitable value in other
embodiments.
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In some embodiments, a ratio of the width TS of the top surface 86 of the
traction lug
58; over the height H of the traction lug 58; may be greater than conventional
tracks.
For example, in some embodiments, the ratio of the width TS of the top surface
86
of the traction lug 58 over the height H of the traction lug 58; may be
greater than
5. one, in some cases at least 1,2, in some cases at least 1.4, in some
cases at least
1.6, in some cases at least 1.8, and in some cases even more (e.g., 2 or
more). The
ratio of the width TS of the top surface 86 of the traction lug 58 over the
height H of
the traction lug 5B may have any other suitable value in other embodiments.
In this embodiment, with its track systems 161-164 designed to better perform
when it
is roading, the agricultural vehicle 10 may travel faster on the road 115
without
excessively wearing or deteriorating the track systems 161-164.
For example, in some embodiments, a speed restriction for the agricultural
vehicle
10 on the road 115 may be laxer (i.e., less stringent) than if an enhanced-
roading
feature (e.g., the lateral load distribution mechanism 100 or the wider and/or
shorter
traction lugs 581-58T) of a track system 16 was omitted but the track system
16 was.
otherwise identical. That is, the agricultural vehicle 10 may be authorized to
travel
faster on the road 115 than if the enhanced-roading feature of the track
system 16;
was omitted but the track system 16 was otherwise identical.
The speed restriction for the agricultural vehicle 10 on the road 115 may be
conveyed by a provider of the track system 16i as a recommended maximal speed
of
the agricultural vehicle 10 on the road 115 in certain conditions, including a
load on
an axle of the vehicle 10 that carries the track system 16. For example, the
provider
of the track system 16; may be a manufacturer of the track system 16, and/or a
manufacturer of the agricultural vehicle 10 (e.g., an original equipment
manufacturer
(OEM)).
For instance, in some embodiments, as shown in a chart represented in Figure
43,
the speed restriction for the agricultural vehicle 10 on the road 115 may be
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expressed as a recommended maximal speed of the vehicle 10 as a function of a
load on an axle of the vehicle 10 carrying the track system 16. ,In this
example, the
axle is a rear axle of the vehicle 10 (e.g., as the load on the rear axle of
the vehicle
may be greater when the work implement 18 is mounted to a rear portion of the
5 vehicle 10). Also, in this example, the track 22 is narrow. More
particularly, in this
example, the width W of the track 22 is 18 inches. Furthermore, in this
example, the
speed restriction for the agricultural vehicle 10 on the road 115 is based on
an
ambient temperature of 25 C. The function expressing the speed restriction for
the
agricultural vehicle 10 on the road 115 based on the load on the axle of the
vehicle
io 10 may be represented as a graph such as a line (e.g., a curve), a
table, a diagram,
or any other information that exiiresses the recommended maximal speed of the
vehicle 10 based on the load on the axle of the vehicle 10.
In this example, the speed restriction for the agricultural vehicle 10 on the
road 115 if
an enhanced-roading feature (e.g., the lateral load distribution mechanism 100
or
the wider and/or shorter traction lugs 581-58-r) of the track system 161was
omitted
but the track system 161 was otherwise identical is represented by a function
denoted "speed restriction without enhanced-roading feature". This can be
established by omitting the enhanced-roading feature (e.g., the lateral load
distribution mechanism 100 or the wider and/or shorter traction lugs 581-58T)
of the
track system 161but keeping the track system 16; otherwise identical. For
instance, in
embodiments in which the bottom track-contacting areas 146 of laterally-
adjacent
ones of the idler wheels 231, 24 261, 262, 281-284 are vertically movable
relative to
one another (e.g., as described in section 1 above), this enhanced-roading
feature
may be omitted by precluding the bottom track-contacting areas 146 of the
laterally-
adjacent ones of the idler wheels 231, 232, 261, 262, 28/-284 from vertically
moving
relative to one another. For example, in embodiments in which the lateral load
distribution mechanism 100 allows the roll motion of laterally-adjacent ones
of the
idler wheels 231, 232, 261, 262, 281-284 about the roll axis 164, this
enhanced-roading
feature may be omitted by precluding the roll motion of the laterally-adjacent
ones of
the idler wheels 231, 232, 261, 262, 281-284about the roll axis 164 (e.g., by
removing,
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blocking or otherwise disabling a pivot enabling the roll motion of the
laterally-
adjacent ones of the idler wheels 231, 232, 26i, 262, 281-284 about the roll
axis 164).
This may be done in the track system 16Ior by replacing the track system 16;
with an
identical track system in which the enhanced-roading feature is omitted.
As shown in the chart, in this example, the speed restriction for the
agricultural
vehicle 10 on the road 115 may be laxer, i.e., the agricultural vehicle 10 may
be
authorized to travel faster on the road 115, with the enhanced-roading
feature. That
is, the speed restriction for the agricultural vehicle 10 on the road 115 with
the
enhanced-roading feature may be defined in a zone SRZ of the chart that is
higher
than the speed restriction without the enhanced-roading feature.
For example, in some embodiments, a ratio of (i) the speed restriction for the
agricultural vehicle 10 on the road 115 with the enhanced-roading feature
(e.g., the
lateral load distribution mechanism 100 or the wider and/or shorter traction
lugs 681-
58T) of the track system 16 over (ii) the speed restriction for the
agricultural vehicle
10 on the road 115 if the enhanced-roading feature of the track system 161 was
omitted but the track system 16i was otherwise identical may be at least 1.10,
in
some cases at least 1.15, in some cases at least 1.20, in some cases at least
1.25,
in some cases at least 1.30, in some cases at least 1.45, and in some cases
even
more (e.g., at least 1.50 or more). This ratio may have any other suitable
value in
other embodiments.
For instance, in some embodiments, when the load at the axle of the vehicle 10
is at
least 40000 lbs, the ratio of (i) the speed restriction for the agricultural
vehicle 10 on
the road 115 with the enhanced-roading feature (e.g., the lateral load
distribution
mechanism 100 or the wider and/or shorter traction lugs 581-581) of the track
system
16 over (ii) the speed restriction for the agricultural vehicle 10 on the road
115 if the
enhanced-roading feature of the track system 161was omitted but the track
system
161 was otherwise identical may be at least 1.10, in some cases at least 1.15,
in
some cases at least 1.20, in some cases at least 1.25, in some cases at least
1.30,
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and in some cases even more (e.g., at least 1.40 or more). This ratio may have
any
other suitable value in other embodiments.
Figures 44 to 48 show examples of subzones Sl1-SZ5 of the zone SRZ of the
chart
in which the speed restriction for the agricultural vehicle 10 on the road 115
with the
enhanced-roading feature can be defined ih various embodiments, where the
agricultural vehicle 10 may be authorized to travel increasingly faster on the
road
115.
As an example, in embodiments in which the lateral load distribution mechanism
100
allows the roll motion of laterally-adjacent ones of the idler wheels 231,
232, 261, 262,
281-284 about the roll axis 164', the speed restriction for the agricultural
vehicle 10 on
the road 115 may be as defined as shown in Figure 49.
In view of the enhanced-roadihg feature of the track system 16, the
agricultural
vehicle 10 may thus be authorized to travel faster on the road 115. Notably,
the track
system 161 may be homologated to allow the agricultural vehicle 10 to travel
faster
.on the road 115. That is, the provider of the track system 16; may officially
authorize
the agricultural vehicle 10 to travel faster on the road 115, including by
conveying
the speed restriction for the agricultural vehicle 10 on the road 115 that is
more lax.
For example, in some embodiments, the provider of the track system 16; may
honor
a warranty for the track system 16; according to the speed restriction for the
agricultural vehicle 10 on the road 115 that is more lax.
The speed restriction for the agricultural vehicle 10 on the road 115 may be
conveyed by the provider of the track system 161 in any suitable way in
various
embodiments. For example, in some embodiments, the speed restriction for the
agricultural vehicle 10 on the road 115 may be conveyed by a tangible medium.
For
instance, the tangible medium may be a manual (e.g., user or operator manual)
provided with the track system 161 and/or the agricultural vehicle 10. The
tangible
medium may be a printed medium (e.g., a paper =copy) or a computer-readable
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storage medium (e.g., a semiconductor memory (e.g., read-only memory (ROM)
and/or random-access. memory (RAM)), a magnetic storage medium, an optical
storage medium, and/or any other suitable type of memory). In some
embodiments,
the speed restriction for the agricultural vehicle 10 on the road 115 may be
conveyed
on an Internet webpage provided by the provider of the track system 16i. In
some
embodiments, the speed restriction for the agricultural vehicle 10 on the road
115
may be conveyed on the user interface 70 of the operator cabin 20 (e.g., on a
graphical user interface (GUI) of a display of the user interface 70). In some
embodiments, the speed restriction for the agricultural vehicle 19 on the road
115
may be conveyed in a memory accessed by a controller of the agricultural
vehicle 10 ,
that controls operation of the 'vehicle 10 (e.g., a powertrain controller such
as an
engine control unit (ECU) that controls the powertrain 15 of the vehicle 10).
Although the agricultural vehicle 10 illustrated in Figure 1 is an
agricultural tractor
comprising four track systems 161-164, different types of agricultural
vehicles
configured differently (e.g., having a different number of track systems) may
implement improvements based on principles disclosed herein.
For instance, with additional reference to Figure 50, an agricultural vehicle
510 may
be provided comprising two track systems 5161, 5162 rather than four (i.e.,
one track,
system 516; at each side of the agricultural vehicle 510). The agricultural
vehicle 510
also comprises a frame 512, a prime mover 514, and an operator cabin 520 and
can
=be equipped with the work implement 18 to perform agricultural work. Each
track
system 5161. comprises a drive wheel 524 at a first longitudinal end portion
of the
track system 516i, an idler wheel 526 at a second longitudinal end portion of
the
track system 5161 opposite to the first longitudinal end portion, and a
plurality of roller
wheels 5281-5286 intermediate the drive wheel 524 and the idler wheel 526. The
track system 5161 further comprises a track 522 disposed around the wheels
524,
526, 5281-5286 and driven by the drive wheel 524. The track system 516; may
implement the lateral load distribution mechanism 100 as described in section
1
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above. Additionally or alternatively, the track 522 may be configured in a
manner
similar to the track 22 as described in section 2 above.
Furthermore, the work implement 18 that is drawn by the agricultural vehicle
10 or
the agricultural vehicle 510 may implement the improvements disclosed herein.
For
instance, with additional reference to Figure 51, the work implement 18 may
comprise a trailed vehicle 610 comprising a frame 612, a body 613 (e.g., a
container) and track systems 6161, 6162. In this example, the trailed vehicle
610 is a
harvest cart. In other examples, the trailed vehicle 610 may be a fertilizer
cart, a
it) sprayer, a planter or any other suitable type of trailed vehicle. Each
track system
6161 of the trailed vehicle 610 comprises front (i.e., leading) idler wheels
6231, 6232
at a first longitudinal end portion of the track system 616, rear (i.e.,
trailing) idler
wheels 6261, 6262 at a second longitudinal end portion of the track system
616;
opposite the first longitudinal end portion, and a plurality of roller wheels
6281-6284
intermediate the front idler wheels 623i, 6232 and the rear idler wheels 6261,
6262.
The track system 616; further comprises a track 622 disposed around the wheels
6261, 6262, 6261, 6262, 6281-6284. The track system 616; may implement the
lateral
load distribution mechanism 100 as described in section 1 above. Additionally
or
alternatively, the track 622 may be configured in a manner similar to the
track 22 as
described in section 2 above.
In this example, the trailed vehicle 610 is not motorized in that it does not
comprise a
prime mover for driving the track systems 6161, 6162. Rather, the trailed
vehicle 610
is displaced by the agricultural vehicle 10 or the agricultural vehicle 510 to
which the
trailed vehicle 610 is attached. However, in some examples, the trailed
vehicle 610
may be motorized. That is, the trailed vehicle 610 may comprise a prime mover
for
driving a drive wheel of each track system 616i. For example, instead of
comprising
rear idler wheels 6261, 6262, the track system 616; may comprise a drive wheel
for
driving the track 622.
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In some examples of implementation, any feature of any embodiment described
herein may be used in combination with any feature of any other embodiment
described herein.
Certain additional elements that may be needed for operation of some
embodiments
have not been described or illustrated as they are assumed to be within the
purview
of those of ordinary skill in the art. Moreover, certain embodiments may be
free of,
may lack and/or may function without any element that is not specifically
disclosed
herein.
Although various embodiments and examples have been presented, this was for
the
purpose of describing, but not limiting, the invention. Various modifications
and
enhancements will become apparent to those of ordinary skill in the art and
are
within the scope of the invention, which is defined by the appended claims.
=
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