Note: Descriptions are shown in the official language in which they were submitted.
1
DRIVE SYSTEM FOR THE REEL OF A CROP HARVESTING HEADER
This invention relates to a drive system for the reel of a crop harvesting
header.
BACKGROUND OF THE INVENTION
This invention relates to a crop harvesting header including a cutter bar
and a reel for controlling movement of the crop in the area over the cutter
bar. The
reel is rotatable about an axis generally parallel to the cutter bar and has a
plurality
of reel bats each having reel tines projecting generally radially outwardly
from the
reel axis. The reel bats are pivotal each about a respective bat axis parallel
to the
reel axis so as to vary the angle of the tines about the bat axis as the reel
rotates.
Typically the reel co-operates with a cam carried on the header in generally
stationary position so that each bat has a crank arm with a cam follower on
the crank
arm which follows the cam as the reel rotates and causes the required pivotal
movement of the bat. An example of a header of this type is shown in US Patent
6,591,598 (Remillard) issued July 15 2003 to the present Assignees.
SUMMARY OF THE INVENTION
According to a first aspect of the invention there is provided a crop
harvesting header comprising:
a header frame structure;
a cutter bar arranged across a forward edge of the header frame
structure;
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a cut crop transport arrangement mounted on the header frame
structure for receiving and transporting the cut crop;
and a reel mounted on the header frame structure;
and a reel drive mechanism for driving rotation of a reel input drive
shaft of the reel about a reel axis generally parallel to the cutter bar, the
reel drive
mechanism comprising:
a variable speed drive motor having a drive output shaft and a
controller which varies an output speed of the drive motor;
and a drive transmission connected between the drive output
shaft of the drive motor and the reel input drive shaft;
the drive transmission including first components which are
selected to provide a first drive ratio between the drive output shaft and the
reel input
drive shaft and second components which are selected to provide a second drive
ratio, different from the first drive ratio, between the drive output shaft
and the reel
input drive shaft.
According to a second aspect of the invention there is provided a crop
harvesting header comprising:
a header frame structure;
a cutter bar arranged across a forward edge of the header frame
structure;
a cut crop transport arrangement mounted on the header frame
structure for receiving and transporting the cut crop;
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and a reel mounted on the header frame structure;
and a reel drive mechanism driving rotation of the reel about a reel axis
generally parallel to the cutter bar, the reel drive mechanism comprising:
a variable speed drive motor and a controller which varies an
output speed of the drive motor;
and a drive transmission connected between the drive motor
and the reel;
wherein the drive transmission includes a first input drive sprocket and
a first output drive sprocket aligned with the first input drive sprocket and
communicating drive to the reel,
wherein the drive transmission includes a second input drive sprocket
and a second output drive sprocket aligned with the second input drive
sprocket and
communicating drive to the reel,
and wherein the drive transmission comprises an elongate timing drive
member which is transferred from a first position interconnecting the aligned
first
sprockets to provide a first drive ratio between the drive motor and the reel
and a
second position interconnecting the aligned second sprockets to provide a
second
drive ratio, different from the first drive ratio, between the motor and the
reel.
Preferably the drive transmission has an output shaft connected to a
shaft of the reel typically at one end of the reel and typically adjacent the
cam control
system which controls the tine angles.
In a case where the reel has two independent sections arranged end to
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end the drive transmission can be located between the two sections and
preferably
has two output shafts each connected to a respective shaft of a respective one
of
the reel sections.
Preferably the transmission includes an elongate timing drive member
driven by a sprocket on the drive output on the drive motor. Typically the
drive
member is a chain but also other similar devices can be used for example a
typical
timing belt.
Preferably the drive transmission includes a first and a second drive
sprocket on the drive output on the drive motor and the chain is arranged to
be
movable from the first sprocket for the first drive ratio to the second
sprocket for the
second drive ratio.
Preferably the drive transmission includes a first and a second input
drive sprocket on the drive output on the drive motor and a first and a second
output
drive sprocket for communicating drive to the reel, where the first sprockets
are
aligned and the second sprockets are aligned and the chain is arranged to be
moved
from a first position interconnecting the aligned the first sprockets for the
first drive
ratio to the aligned second sprockets for the second drive ratio. The
sprockets are
selected so that the same length of the chain locates the sprockets on the
shaft
forming the drive output on the motor and the output to the reel approximately
at the
same distance apart so that the chain can be simply transferred when the
tension is
released.
Preferably however there is provided a device for tensioning the chain
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across the sprockets which is operable to release the tension to allow the
chain to
be transferred and to take up tension differences from the change in length of
the
sprockets and from other effects such as wear or stretch..
Preferably the device for tensioning comprises a mounting member
which allows relative movement between the drive output of the drive motor and
the
output shaft to the reel to change the distance therebetween. This is
preferably
done by mounting the output shaft to the reel on a movable support. However
the
drive motor can be mounted on a movable support. Preferably there is provided
a
housing for containing the sprockets and the chain and the movable support is
movable within the housing. As an alternative to the movable mounting of one
of
the shafts carrying the sprockets, a separate tensioner can be provide which
takes
up the slack in the chain so that the shafts can remain fixed.
Preferably there is provided an adjustment device in the housing for
setting the tension in the chain at a required value. This can be done by
adjusting
the relative positions of the shafts or by providing a separate tensioner.
Preferably the adjustment device comprises a ratchet and when the
adjustment is carried out by supporting one of the shafts for movement, the
ratchet
controls the position of the support in the housing.
In order to allow simple manual access to the components to provide
the change of the ratios, preferably the housing includes a removable cover
portion
which can be readily manually removed to expose the sprockets and the chain
for
manual movement thereof. In this case, preferably the housing cover portion is
held
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in place by simple clips which can be manually removed without tools and when
the
housing cover portion is removed, the movable support is free to be moved
without
obstruction by the housing and without removing other parts.
The arrangement described herein thus allows the drive ratio to be
changed in addition to the speed changes available from the variable speed
motor.
It has been found by careful analysis of the drive system of the reel in
systems of
this type that higher speeds of the reel are necessary to meet the high ground
speed
now available from other machine improvements. While it would normally be
expected that such higher speeds could be met simply by increasing the speed
available from the variable speed drive motor, it has been found that such
higher
speeds can lead to a reduced torque being available at lower speeds. In some
cases the reduced torque becomes insufficient to prevent stalling of the reel
movement in very heavy crop conditions. Thus it has been found necessary to
provide a simple rapid way for the operator to change the drive ratios
available to the
system for both high speed and low speed operations.
The transmission components to provide the two, or more, separate
ratios are located in the system that is within the housing so that the change
can be
made without tools and without separate spare parts.
BRIEF DESCRIPTION OF THE DRAWINGS
One embodiment of the invention will now be described in conjunction
with the accompanying drawings in which:
Figure 1 is a side elevational view of a header according to the present
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invention.
Figure 2 is an isometric view of the drive system of the header of
Figure 1.
Figure 3 is a rear elevational view of the drive system of Figure 2 with
the housing broken away to show the drive system.
Figure 4 is a front elevational view of the drive system of Figure 2 with
the housing broken away to show the drive system.
Figure 5 is a vertical cross-sectional view of the drive system of Figure
2 with the front cover removed.
Figure 6 is a top plan view of the drive system of Figure 2 with the
housing broken away to show the drive system.
DETAILED DESCRIPTION
In Figure 1 is shown an embodiment of a header according to the
present invention with a number of the elements being shown schematically
since
the general construction of such headers is well known to one skilled in the
art The
header 10 includes a header frame 11 having a main frame tube 12 extending
across the width of the header between two end frames one of which is shown at
13
and the other of which is of course at the other end and therefore not visible
in the
elevation of Figure 1. The main tube 12 is suitably supported and attached on
a
propulsion vehicle in a manner so that the header frame can be moved forwardly
across the ground in cutting a standing crop. The end frame 13 extends
forwardly
from the main tube 12 to a forward nose section 14. The main tube 12 carries a
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plurality of frame bars which extend downwardly and forwardly for supporting a
table
15 of the header onto which crop material is deposited after cutting. The
structural
elements defining the frame bars on the table are not shown for convenience of
illustration since again these are well known to one skilled in the art and
can vary in
accordance with engineering considerations.
On the table 15 is provided a crop conveyor 16 which is arranged to
transport the crop after cutting across the width of a header to a discharge
location.
In the embodiment shown the conveyor is provided as a draper canvas 17 mounted
on rollers 18. Other embodiments can use alternative crop transportation
systems
and primarily an auger which is commonly used as an alternative for the draper
system. The embodiments of the present invention are not limited to either of
the
different types of header.
At the front of the table 15 is provided a cutter bar generally indicated
at 19 which is again only shown schematically since the construction of this
is well
known to one skilled in the art. The cutter bar shown provides a sickle knife
in
guards which reciprocates back and forth in a cutting action on the standing
crop so
that the crop is deposited on the draper for transportation to the discharge
location.
When used on a combine harvester the discharge location is
associated with a crop transfer system which transfers the crop rearvvardly
into the
feeder house of the combine. Headers of this type can of course also be used
as a
swather where the discharge location simply discharges the crop onto the
ground in
a swath or through a crop conditioner onto the ground.
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The header further includes a reel generally indicated at 20. The reel
20 includes mounting arms 21 pivoted on a suitable mounting 22 adjacent the
tube
12 so that the arms project forwardly from the frame to a position over the
end frame
elements 13 so as to provide support for the reel extending the header above
the
-- cutter bar. Each arm is movable in its pivotal action by a suitable drive
actuator 23.
The number of arms can vary in accordance with engineering
requirements depending upon the width of the header. Some headers have only
arms at the ends and some have additional arms intermediate the ends to
provide
the necessary support.
The reel 20 thus is mounted by the arms on the header frame structure
for movement with the header in the direction of movement. The reel includes a
shaft 25 mounted for rotation about an axis 26 on the arms and driven by a
rotary
drive mechanism 30 for driving rotation of the reel about the reel axis which
is
generally parallel to the cutter bar.
The reel has a plurality of reel bats 26 at spaced positions around the
reel axis 26 with each reel bat 26 having a tine tube 27 and a plurality of
tines 28
mounted on the tine tube 27 and projecting generally radially outwardly from
an axis
27A of the tine tube 27 parallel to the reel axis 26.
Each of the reel bats 26 is pivotal about its respective axis 27A so as
to vary the angle of the tines or fingers about the bat axis as the reel
rotates. A cam
arrangement 29 described in detail in the above patent of Remillard drives
this
movement at angular positions around the reel axis with the bats pivoting
rapidly
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back and forth as the reel rotates.
The reel drive mechanism for driving rotation of the reel about a reel
axis generally parallel to the cutter bar is generally indicated at 30 and is
mounted, in
a single part reel, on one end of the reel.
The reel drive mechanism 30 comprises a housing 31 which is
mounted on one of the reel support arms 21 at a coupling 32 so that the
housing is
fixed with the reel support arms on the reel axis and provides an output drive
shaft
33 for connection to the reel shaft 25 at a disk coupling 34 which bolts onto
a
cooperating coupling on the shaft 25 (not shown).
The housing 31 comprises a back plate 35 and a front container
portion 36 enclosing an interior area receiving a drive transmission 37.
The reel drive mechanism includes a hydraulic drive motor 38 powered
by fluid from the drive vehicle which includes a fluid supply 39 and a control
40
which operates to control a rate of supply of the fluid so as to vary a
rotation rate of
the motor in conventional manner.
The motor 38 has a drive output shaft 41, an output speed of which
can be varied by the control 40 to provide a variable speed drive to the reel.
The
output shaft provides rotary drive to the drive transmission 37 for
communicating the
drive output to the reel through the output shaft 33.
The shaft 41 communicates drive to the shaft 33 though a sprocket
assembly 42 on the shaft 41 and a sprocket assembly 43 on the shaft 43
connected
by a chain 44. Each of the sprocket assemblies 42 and 43 comprises a pair of
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sprockets 42A and 42B which cooperate with sprockets 43A and 43B respectively
so
that the drive transmission is arranged to provide two different drive ratios.
It will be
appreciated that more than two drive ratios can be provided by addition of
further
sprockets at the assemblies 42 and 43. However typically two drive ratios is
sufficient.
Thus the drive transmission includes a first and a second input drive
sprocket 42A and 42B on the drive output 41 on the drive motor 38 and a first
and a
second output drive sprocket 43A and 43B for communicating drive to the reel
through the shaft 33. The first sprockets 42A and 43A are aligned and the
second
sprockets 42B and 43B are aligned and the chain is arranged to be movable from
a
first position interconnecting the aligned the first sprockets 42A, 43A for
the first
drive ratio to the aligned second sprockets 42B, 43B for the second drive
ratio.
The shaft 33, its bearings 33A and the sprockets 43 are carried on a
plate 45 which is mounted in the housing 31 for sliding movement in a
direction
toward and away from the shaft 41 so as to increase and decrease the spacing
between the sprocket assemblies 42 and 43. This movement therefore acts as a
device for tensioning the chain 44 across the sprockets. The plate is guided
in
slides 45A and 45B and is moved by an eccentric cam 46 carried on the housing
an
operable in a slot 47 in the plate 45. Operation of the cam 46 by a wrench
applied
onto a nut 48 rotates the cam and is operable to release the tension on the
chain 44
to allow the chain to be transferred from the sprockets 42A, 43A as shown at
first
position 44A to the sprockets 42B, 43B as shown at second position 44B. This
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transfer is done manually after the tension is released and sufficient slack
made
available to lift the chain off the sprockets.
Thus the plate 45 acts a mounting member which allows relative
movement between the drive output 41 of the drive motor 38 and the output
shaft 33
to the reel to change the distance therebetween.
The cam 46 carries a ratchet 49 which rotates with the cam relative to
a pawl 50 which can be released by a finger lever 51. In order to allow the
movement to release the tension therefore the pawl is lifted and the cam
rotated to
drive movement of the plate 45.
After the transfer of the chain is completed, the cam 46 is rotated in the
opposite direction to drive the plate 45 in a direction to tighten the chain
to a required
tension. This rotation of the cam rotates the ratchet over the pawl until
sufficient
tension is obtained whereupon the pawl holds the ratchet at the required
angular
position to maintain this tension. A bar 52 projecting through a hole in the
guide 45A
locates the ratchet is held against unintended movement. The simple actuation
of
the movement of the plate which supports the shaft 33 which can be achieved in
a
controlled manner by the ratchet thus allows the user to quickly change the
transmission from the first ratio to the second ratio.
In order to rapidly access the interior of the housing to the housing
includes a removable cover portion 53 which defines a front upper part of the
housing 31 with a top edge 54 and a bottom edge 55 which can be readily
manually
removed to expose the sprockets 42, 43 and the elongate timing drive member 44
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for manual movement thereof as described above. The housing incudes an upper
cap portion 57 over the upper sprocket 42 and a bottom generally semi-
cylindrical
portion 58 surrounding the bottom sprockets 43. The upper edge of the bottom
portion 58 has clips 56 which receive and hold the bottom edge 55 of the
portion 53
to hold it in place when assembled. The top edge 54 is retained by a spring
clip 59
which is carried on the housing 31 held in place between two projecting
portions 60
and 61 and which can be lifted off the portion 53 over the projection 60 to
allow it to
be pivoted forwardly for opening and lifting from the clips 56. This simple
release of
the front cover portion 53 without the use of tools allows the movable support
to be
exposed and free to be moved.
The following instructions for the actions to be taken are provided:
--unlatch top cover and remove drive cover 53
-- loosen chain 44 using the wrench on the ratchet 49 and cam drive
46
--hold the ratchet release 50 in unlocked position
--rotate wrench handle on cam drive nut 48 upwards to loosen the
chain 44 and move the chain 44 to appropriate sprocket set 42A, 42B
--chain 44 on small driven sprocket 428 provides high speed. This can
provide in one example a maximum torque in the range 13,000 to 14,000 in-lbs
and
a maximum speed of the order of 115 rpm.
--chain 44 on large driven sprocket 42A provides high torque. This can
provide in one example a maximum torque in the range 23,000 to 24,000 in-lbs
and
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a maximum speed of the order of 73 rpm.
--tighten the chain 44 by moving the plate 45
--rotate wrench handle on nut 48 downwards until tight
--re-install cover 53 and secure with latch 59.
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