Note: Descriptions are shown in the official language in which they were submitted.
CA 02820565 2013-07-10
HYDRAULIC ASSEMBLY AND LOGGING EQUIPMENT USING SAME
FIELD
The present disclosure relates generally to a hydraulic assembly. More
particularly,
the present disclosure relates to a hydraulic assembly for logging equipment
and, even more
particularly, to a hydraulic assembly for a rotator link assembly in logging
equipment.
BACKGROUND
Hydraulic assemblies, including hydraulic conduits, are used for the
communication of
pressurized fluid to drive hydraulic components. In some cases, the hydraulic
components
may be part of a mechanical system that includes pivot points for rotational
movement of
mechanical or hydraulic components.
In a particular case, the hydraulic component may be for driving a rotator and
an
implement that are suspended at the end of a crane. In this case, hydraulic
conduits run
from a pressure medium source along a crane through a rotator link assembly
and to the
implement. The rotator link assembly includes a hydraulic component for
driving rotation of
the implement as well as a hydraulic component for operating the implement.
The rotator
link assembly also includes a pivot connection to the crane. In this
situation, it may be
difficult to provide durable hydraulic conduit connectors as the hydraulic
conduits will be
under stress as a result of the movement of the crane, pivot connection,
rotator, and the
implement.
Further, when fed along a crane, via a rotator link assembly to an implement,
the
hydraulic conduits may be exposed to surrounding objects when the crane, pivot
connection,
or rotator moves and this may cause damage to the hydraulic conduits. Damage
to the
hydraulic conduits may lead to failure of the conduit and hydraulic fluid
leakage. When
damaged, the hydraulic conduits must be replaced causing reduced production
and
increased operational costs.
Examples of conventional hydraulic conduit assemblies are described in United
States Patent Application Publication No. 2013/0056588 to Harr et al. and
United States
Patent No. 7,311,489 to Ekman.
It is, therefore, desirable to provide a hydraulic assembly configured to
reduce
hydraulic conduit failure.
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SUMMARY
It is an object of the present disclosure to obviate or mitigate at least one
disadvantage of previous hydraulic assemblies or systems.
In an aspect, the present disclosure provides a hydraulic assembly including a
pivot
connection defining a pivot axis, a hydraulic element linked to the pivot
connection, and a
connector for connecting a hydraulic conduit to the hydraulic element. The
connector defines
a connection axis and the connector is configured such that the connection
axis
approximately intersects the pivot axis.
In a particular case, the hydraulic element may include a hydraulic drive.
In another particular case, the pivot connection may include a pair of pins
attaching
the hydraulic element to a link and the hydraulic conduit passes between the
pair of pins.
In the case of a hydraulic drive, the hydraulic drive defines a hydraulic
drive axis and
an angle between the connection axis and the hydraulic drive axis may be
greater than
approximately 5 degrees and less than approximately 85 degrees.
In a further particular case, the angle may be approximately 30 degrees.
In a further case, the hydraulic drive may include a rotational drive and the
hydraulic
drive axis is the axis of rotation of the rotational drive.
In another aspect, the present disclosure provides equipment including a link,
a
rotator pivotally attached to the link at a first pivot connection defining a
first pivot axis and a
hydraulic assembly. The hydraulic assembly includes a hydraulic element
provided to the
rotator and a connector provided to the rotator for connecting a hydraulic
conduit to the
hydraulic element. The connector defines a connection axis and the connector
is configured
such that the connection axis approximately intersects the first pivot axis.
In a particular case, the hydraulic element may be a rotational drive defining
a
rotation axis and an angle between the connection axis and the rotation axis
may be greater
than approximately 5 degrees and less than approximately 85 degrees. In a
particular case,
the angle may be approximately 30 degrees.
In a particular case, the first pivot axis may be perpendicular to the
rotation axis.
In a further particular case, the first pivot connection may include a first
pair of pins
attaching the rotator to the link and the hydraulic conduit passes between the
first pair of
pins.
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In another particular case, the equipment further may include a crane and the
link
may be pivotally attached to the crane at a second pivot connection defining a
second pivot
axis.
In a further particular case, the equipment may further include a crane
connector
provided to the crane for connecting the hydraulic conduit to the crane. The
crane connector
defines a crane connection axis and the crane connector is configured such
that the crane
connection axis approximately intersects the second pivot axis.
In a further particular case, the second pivot axis may be perpendicular to
the first
pivot axis.
In a further particular case, the second pivot connection may include a second
pair of
pins attaching the link to the crane and the hydraulic conduit passes between
the second pair
of pins.
In a further case, the hydraulic element may be an implement provided to the
rotator
and the hydraulic conduit supplies hydraulic fluid to the implement.
In still a further case, the implement may be a grappler.
In yet further case, the hydraulic element may include a plurality of
hydraulic elements
and the hydraulic conduit may include a plurality of hydraulic conduits
supplying hydraulic
fluid to the plurality of hydraulic elements.
In this case, the plurality of hydraulic elements may include a rotational
drive and a
grappler.
Other aspects and features of the present disclosure will become apparent to
those
ordinarily skilled in the art upon review of the following description of
specific embodiments in
conjunction with the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present disclosure will now be described, by way of example
only, with reference to the attached Figures.
Figure 1 is a photograph of logging equipment, and, in particular, a
forwarder, having
a rotator link assembly;
Figures 2A, 2B, 2C, 2D, 2E, 2F, and 2G illustrate perspective, detailed, side,
end,
section (along section 2E-2E of Figure 2C), top, and bottom views of a crane
and a rotator
link assembly, in accordance with an embodiment;
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Figures 3A and 3B are perspective views of a rotator, in accordance with an
embodiment.
Figures 4A, 4B, 4C, 4D, and 4E are front, bottom, top, side, and rear views,
respectively, of the rotator of Figures 3A and 3B;
Figure 5 is a section view of the rotator of Figures 3A and 3B along section 5-
5 of
Figure 4A;
Figure 6 is a section view of the rotator of Figures 3A and 3B along section 6-
6 of
Figure 4B;
Figure 7 is a section view of the rotator of Figures 3A and 3B along section 7-
7 of
Figure 4A;
Figure 8 is a section view of the rotator of Figures 3A and 3B along section 8-
8 of
Figure 4C;
Figure 9 is a section view of the rotator of Figures 3A and 3B along section 9-
9 of
Figure 4C;
Figure 10 is a section view of the rotator of Figures 3A and 3B along section
10-10 of
Figure 4C;
Figure 11 is a section view of the rotator of Figures 3A and 3B along section
11-11 of
Figure 4A;
Figure 12 is a section view of the rotator of Figures 3A and 3B along section
12-12 of
Figure 4A;
Figure 13 is a section view of the rotator of Figures 3A and 3B along section
13-13 of
Figure 4E;
Figure 14 is a section view of the rotator of Figures 3A and 3B along section
14-14 of
Figure 4A;
Figure 15 is a schematic diagram of the connection axes of the rotator of
Figures 3A
and 3B; and
Figure 16 is a schematic diagram of the crane connection axis of the crane of
Figures 2A to 2G.
DETAILED DESCRIPTION
Generally, the present disclosure provides a hydraulic assembly and, in
particular a
hydraulic assembly for a rotator link assembly for passing hydraulic fluid
from a crane to a
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hydraulic drive. In this disclosure, the embodiments of the hydraulic assembly
are described
as an element of a rotator link assembly; however, one of skill in the art
will understand that
the hydraulic assembly may be applied in other hydraulic systems.
Figure 1 illustrates an example of logging equipment where a rotator link
assembly 10
may be used. In this case, the logging equipment is a forwarder 12. An
operator of the
forwarder 12 maneuvers a crane 14 above objects (e.g. logs) 16 to be picked up
and
actuates a grapple implement 18 to close arms of the grapple implement 18
around the logs
16. The crane 14 may have a telescopic boom which extends telescopically along
the length
of the crane 14. Either before or after the arms of the grapple implement 18
are closed, the
operator may use the rotator link assembly 10 to rotate the grapple implement
18 while also
manipulating the crane 14. By appropriately operating the rotator link
assembly 10 and
grapple implement 18, the operator can load the logs 16 into a trailer 20. The
rotator link
assembly 10 in Figure 1 is a conventional rotator link assembly but could be
replaced by a
rotator link assembly as described herein. It will further be understood that
the rotator link
assembly as described herein may be used in a variety of operations, not
limited to the
forwarder 12 or other logging applications.
Figures 2A to 2G illustrate various views of a crane 112 having a rotator link
assembly 100, in accordance with an embodiment. The rotator link assembly 100
attaches
on a distal end 113 of the crane 112. The other end of the rotator link
assembly 100
connects to an implement 114. In the embodiment shown, the implement 114 is a
grappler.
The implement 114 may be any type of implement 114 which operates using
hydraulics, as is
known in the art. The rotator link assembly 100 is particularly useful where
rotation about at
least one axis and actuation of an implement is desired.
As shown in more detail in Figure 2B, the rotator link assembly 100 includes a
link
116 and a rotator 118. The link 116 connects to the rotator 118 by a first
pivot connection
120 having a first axis 122. The first axis 122 may be horizontal in an at
rest configuration.
The link 116 also connects to the distal end 113 of the crane 112 by a second
pivot
connection 124 having a second axis 126. The second axis 126 may also be
horizontal in an
at rest configuration but is oriented perpendicular to the first pivot axis
122. The pivot
connections 120, 124 thus allow the rotator 118 to rotate freely about the
first and second
axes 122, 126. The first pivot connection 120 includes a pair of laterally
spaced pins 128,
130 and the second pivot connection 124 includes a pair of laterally spaced
pins 132, 134.
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The pivot pins 128, 130, 132, 134 are spaced to allow hydraulic conduits 136,
137 to pass
therebetween. The first pivot connection 120 may include a friction device 138
for
dampening motion about the first axis 122 due to the movement of the rotator
118.
Figures 3A and 38 illustrate the rotator 118, in accordance with an
embodiment.
Figures 4A, 4B, 4C, 4D, and 4E illustrate front, bottom, top, side, and rear
views of the
rotator 118. Figures 5-14 illustrate sectional views of the rotator 118.
The rotator 118 rotates the implement 114 around a rotation axis 144. The
rotation
axis 144 is vertical in an at rest configuration and perpendicular to one or
both of the first axis
122 and the second axis 126. The rotation axis 144 is perpendicular to the
pins 128, 130
between the link 116 and rotator 118. The pins 128, 130 engage with
bearings129a, 129b of
the rotator 118.
The rotator 118 includes a rotary manifold 142 housing a hydraulic motor 140
(rotational drive) and a rotate shaft 150. The hydraulic motor 140 is integral
to the rotator
118 and powers rotation of the rotate shaft 150 about the rotation axis 144.
The rotate shaft
150 is affixed to the implement 114 by a taper lock bushing 152, retaining
bolts 154, and an
implement attachment 156, such that the implement 114 will rotate with respect
to the rotary
manifold 142 about the rotation axis 144.
As shown in Figures 2A-2G, hydraulic fluid is supplied from a hydraulic pump
or
controller (not shown) at the crane 112 to two hydraulic drives at the rotator
118 via hydraulic
conduits 136, 137. In this case, the hydraulic drives include the hydraulic
motor 140 and the
implement 114 but there may be embodiments where there may be one hydraulic
drive or a
plurality of hydraulic drives. The hydraulic conduits 136, 137 are generally
flexible hoses, as
is known in the art. For ease of reference, both the hydraulic pump/controller
and the
hydraulic drives will be referred to as hydraulic elements. The hydraulic
controller includes a
pump, valves, and user controls as is known in the art.
A first pair of the hydraulic conduits 136 powers and controls the hydraulic
motor 140.
The hydraulic fluid supplied by the hydraulic conduits 136 passes into and out
of passages
146 in the rotary manifold 142 and into pressure and return portions of the
hydraulic motor
140. A check valve and check valve conduit 174 can be provided in the rotary
manifold 142
to compensate for any hydraulic fluid leaks. The rotate shaft 150 includes
vanes 158 which
are driven by the hydraulic motor 140 to rotate the rotate shaft 150 about the
rotation axis
144.
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A second pair of the hydraulic conduits 137 provides hydraulic fluid to
actuate hydraulic
cylinder 139 of the implement 114. The second set of hydraulic conduits 137
pass hydraulic
fluid through passages 147 in the rotary manifold 142 to the rotate shaft 150.
The hydraulic
fluid then passes through passages 149 in the rotate shaft 150 to openings 162
on an external
surface 164 at the opposite end of the rotate shaft 150. The hydraulic fluid
then passes through
to the hydraulic cylinder 139 of the implement 114. The hydraulic fluid in the
passages 147 can
be sealed with seals 160.
As shown in FIGS. 3A and 3B, the first pair of hydraulic conduits 136 includes
a first
motor conduit 136a for supplying hydraulic fluid to rotate the hydraulic motor
140 clockwise (as
viewed from the top of the rotator 118, e.g. FIG. 2F). The first pair of
hydraulic conduits 136
also includes a second motor conduit 136b for supplying hydraulic fluid to
rotate the hydraulic
motor 140 counter-clockwise (as viewed from the top of the rotator 118, e.g.
FIG. 2F). The
second pair of hydraulic conduits 137 includes a first grapple conduit 137a
for supplying
hydraulic fluid to close the implement 114. The second pair of hydraulic
conduits 137 also
includes a second grapple conduit 137b for supplying hydraulic fluid to open
the implement
114.
The rotate shaft 150 is supported by bearings 166 that transfer vertical loads
from the
implement 114 to the link 116 then to the crane 112 through the pins 128, 130,
132, 134.
Horizontal loads are taken by contact between the rotate shaft 150 and the
rotary manifold 142
at positions above and below the hydraulic motor 140.
The rotator 118 includes connectors 148 for connecting the hydraulic conduits
136, 137
to the rotary manifold 142. Each of the connectors 148 has a connection axis
170 defined by
the direction the hydraulic conduits 136, 137 connect to connectors 148.
FIG. 15 is a schematic drawing illustrating a hydraulic assembly 169,
according to an
embodiment herein. In particular, the hydraulic assembly 169 includes the
first pivot connection
120 defining the first axis 122 and the connector 148 defining the connection
axis 170 where
the connectors 148 are configured such that the connection axis 170
approximately intersects
the first axis 122. As shown in FIG. 16 with reference to FIGS. 2A to 2G, a
generally similar
hydraulic assembly 176 can be provided at the crane 112, where crane
connectors 168 are
.. provided to the crane 112 to connect the hydraulic conduits 136, 137 to the
hydraulic controller
(not shown). The placement of the crane connectors 168
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defines a crane connection axis 171 which is directed to approximately
intersect the second
axis 126 of the second pivot connection 124 of the rotator link assembly 100.
This configuration of the connectors 148, 168 on the rotator 118 and on the
crane 112
such that the respective axes intersect related pivot axes is intended to
reduce damage to
the hydraulic conduits 136, 137 during operation. Further, the configuration
is intended to
permit the hydraulic conduits 136, 137 to flex naturally within hose design
limits while
minimizing the size of the rotator link assembly 100 with a compact design.
In embodiments herein, "approximately intersecting" is intended to include a
range of
values based on various factors, for example, the diameter of the hydraulic
conduit 136, 137,
the allowable bend radius of the hydraulic conduit 136, 137, the distance
between the
connectors 148, 168 on either side of the first and second axes 122, 126, and
the length of
the hydraulic conduits 136, 137. For example, "approximately intersecting" may
include a
situation where the connection axis 170, 171 is within a radius of the
hydraulic conduit 136,
137 of intersecting the axis 122, 126. In one particular prototype, connectors
148 connected
with hydraulic conduits 136, 137 having an outside diameter of 23.4 mm and the
connection
axis 170 passed within 18.5 mm of the first axis 122 (measured perpendicular
to the first axis
122), the hydraulic conduits 136, 137 moved through a desired range of motion
and
appeared to function acceptably during testing.
The configuration of the embodiments herein is beneficial because, when the
connection axes 170, 171 passes further away from the first and second pivot
axis 122, 126,
buckling of the hydraulic conduits 136, 137 may occur. Further, where the
connection axes
170, 171 do not approximately intersect the first and second axes 122, 126,
the hydraulic
conduits 136, 137 may undesirably bend in the wrong direction during pivoting.
The configuration of the embodiments herein is also beneficial because it
allows for a
compact design. For example, if the hydraulic conduits 136 or 137 are put into
a linear
position where the connectors 148 are rotated to face the connectors 168 and
the respective
connection axes pass through the first axis 122 and the second axis 126, this
linear position
determines the minimum length of the hydraulic conduit 136, 137. That is, to
allow the
connectors 148, 168 to be at the minimum distance possible for the most
compact design,
the connectors 148, 168 face directly at the first and second axes 122, 126.
Although this
configuration might provide the minimum distance, in practical applications,
the hydraulic
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conduits 136, 137 may have some additional length, for example, at least one
or two
additional radius of length.
When the connectors 148, 168 are positioned at a distance from the first and
second
axes 122, 126 less than the minimum allowed bend radius of the hydraulic
conduits 136, 137
on either side of the first and second axes 122, 126, the hydraulic conduits
136, 137 may
buckle. If the connectors 148, 168 are farther from the first and second axes
122, 126, the
hydraulic conduits 136, 137 may permissibly buckle within the bend radius of
the hydraulic
conduit 136, 137.
In the embodiment of the rotator link assembly 100, a distance between the
first axis
122 and the top of the rotator 118 may be reduced by also positioning the
connectors 148 for
the hydraulic conduits 136, 137 on the rotator 118 such that the connection
axis 170 is not
parallel with the rotation axis 144 of the hydraulic motor 140. For example,
the connection
axis 170 may be at an angle 172 of 5 to 85 degrees with respect to the
rotation axis 144. In
other cases the angle may be between 20 and 70 degrees or between 30 and 60
degrees. In
a particular case, the connection axis 170 may be at an angle 172 of
approximately 30
degrees with respect to the rotation axis 144. Generally speaking, the first
axis 122 is
positioned as close to the hydraulic connectors 148 as possible based on the
flexibility and
the design constraints of the hydraulic conduits 136, 137.
As shown in, for example, figure 2B, the connectors 148, 168 are also
positioned to
generally route the hydraulic conduits 136, 137 between the pins 128, 130 of
the first axis
122 and the pins 132, 134 of the second axis 126.
In conventional systems, hydraulic conduits typically run exposed outside of a
link
between the end of the crane and the implement. In contrast, the hydraulic
conduits 136,
137 pass through the pins 128, 130 of the first axis 122 and the pins 132, 134
of the second
axis 1261n a manner that reduces damage to the hydraulic conduits 136, 137
when the pivot
pins 128, 130, 132, 134 articulate. The routing path of the hydraulic conduits
136, 137
between each pair of pins 128, 130 and 132, 134 at each axis 122, 126 is
intended to protect
the hydraulic conduits 136 from damage from external materials such as trees
or the like to
the rotator link assembly 100.
The connectors 148 are not overly exposed, reducing the chance of accidental
impact
and damage and providing a compact design and access for repairs. The
configuration of
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the connectors 148 to the rotator 118 may also reduce the need to provide a
protective cover
to the hydraulic conduits 136, 137.
While the axes 122, 126, 144, are described as being, horizontal, horizontal,
and
vertical when at rest, it will be understood that these axes 122, 126, 144
need not be
horizontal and vertical and the orientation may depend on the required
orientation of the
hydraulic assembly, and, in this embodiment, of the crane 112 and the rotator
link assembly
100.
In the preceding description, for purposes of explanation, numerous details
are set
forth in order to provide a thorough understanding of the embodiments.
However, it will be
apparent to one skilled in the art that these specific details may not be
required. In other
instances, well-known structures may be shown in block diagram form in order
not to
obscure the understanding. The above-described embodiments are intended to be
examples only. Alterations, modifications and variations can be effected to
the particular
embodiments by those of skill in the art without departing from the scope,
which is defined
solely by the claims appended hereto.
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