U.S. patent application number 09/399870 was filed with the patent office on 2001-10-04 for tracked suspension.
Invention is credited to BOCK, TIMOTHY J., LYKKEN, THOMAS G., STOLTMAN, RUSSELL V., VIK, BRIAN D..
Application Number | 20010025732 09/399870 |
Document ID | / |
Family ID | 23581303 |
Filed Date | 2001-10-04 |
United States Patent
Application |
20010025732 |
Kind Code |
A1 |
LYKKEN, THOMAS G. ; et
al. |
October 4, 2001 |
TRACKED SUSPENSION
Abstract
A tracked suspension for a tractor or other work vehicle is
disclosed having an endless belt, a belt tensioner, a drive wheel,
and a plurality of idler wheels mounted to a suspension frame or
idler carriage, the assembly being arranged such that the belt
tension provided by the tensioner is absorbed within the frame and
is not transmitted to the axle extending from the tractor that
drives the tracked suspension. The tracked suspension can be
adjusted by loosening or removing mounting bolts that fix the
suspension to beams extending from the vehicle, sliding the
suspension toward or away from the vehicle, and tightening the
bolts. By absorbing the belt tensioning forces within the tracked
suspension itself, rather than transmitting the belt tensioning
forces to the axle, the suspension can be more easily adjusted
without requiring the removal and replacement of the drive
axle.
Inventors: |
LYKKEN, THOMAS G.; (FARGO,
ND) ; VIK, BRIAN D.; (FARGO, ND) ; BOCK,
TIMOTHY J.; (FARGO, ND) ; STOLTMAN, RUSSELL V.;
(FARGO, ND) |
Correspondence
Address: |
STEPHEN MICHAEL PATTON
FOLEY & LARDNER
FIRSTAR CENTER
777 EAST WISCONSIN AVENUE
MILWAUKEE
WI
532025367
|
Family ID: |
23581303 |
Appl. No.: |
09/399870 |
Filed: |
September 20, 1999 |
Current U.S.
Class: |
180/9.48 ;
180/9.1 |
Current CPC
Class: |
B62D 49/0678 20130101;
B62D 55/00 20130101; B62D 55/104 20130101; B62D 55/084
20130101 |
Class at
Publication: |
180/9.48 ;
180/9.1 |
International
Class: |
B62D 055/00 |
Claims
The embodiments of the invention in which an exclusive property or
privilege is claimed are defined as follows:
1. A tracked suspension for an agricultural tractor, comprising: an
idler wheel carriage slidably and fixedly mounted to suspension
beams extending from the tractor frame; a fore and aft extending
beam having a forward portion and a rearward portion and pivotally
coupled to the idler wheel carriage about a first pivotal axis; a
rear idler wheel pivotally coupled to the rearward portion of the
beam and rotatable with respect thereto; a front idler wheel
pivotally coupled to the forward portion of the beam and rotatable
with respect thereto; a belt tensioner coupled to the rear idler
wheel to extend or retract the rear idler wheel with respect to the
beam; two roller wheels disposed between the front and rear idler
wheels and rotatably coupled to the beam; a drive wheel support
fixedly mounted to the idler wheel carriage; a drive wheel
rotatably coupled to the drive wheel support and rotating about a
drive wheel rotational axis; and an endless track extending about a
periphery of the two roller wheels, the front and rear idler wheels
and the drive wheel.
2. The tracked suspension of claim 1, wherein the drive wheel
rotational axis is disposed above and between the front and rear
idler wheels, and further wherein the first pivotal axis is
disposed below the drive wheel rotational axis.
3. The tracked suspension of claim 2, wherein the drive wheel
support includes a sun gear configured to be driven by an axle
extending from a differential and at least one planetary gear.
4. The tracked suspension of claim 3, wherein the drive wheel is
fixedly mounted to a ring gear driven by the planetary gear.
5. The tracked suspension of claim 4, wherein the beam includes a
pivot ear extending laterally outward and upward away from the fore
and aft extending beam, and a second pivot ear extending laterally
inward and upward away from the fore and aft beam, each of the
first and second pivot ears including a pivot at an upper end
thereof that defines a first pivotal axis.
6. The tracked suspension of claim 5, further comprising inner and
outer drive wheel bearings to support relative rotational motion of
the drive wheel with respect to the drive wheel support, and
further wherein the ring gear, the sun gear and the planetary gear
are disposed laterally between the inner and outer wheel
bearings.
7. The tracked suspension of claim 6, wherein the idler wheel
carriage includes a substantially vertical plate having a clamp for
clamping an outer end of the wheel support, wherein the plate is
disposed above and between the forward and rearward tubular
members.
8. The tracked suspension of claim 7, wherein the idler wheel
carriage includes forward and rearward laterally extending members
adapted to slidably receive suspension beams extending from the
tractor, the forward member disposed forward of and below the drive
wheel rotational axis, and the rearward member disposed rearward of
and below the drive wheel rotational axis.
9. A tracked suspension for an agricultural tractor, comprising: an
endless track; a suspension frame configured to be slidably and
fixedly mounted to at least one suspension beam extending from a
frame of the tractor; a beam extending parallel to a direction of
travel and pivotally coupled to the suspension frame about a first
pivotal axis substantially perpendicular to the direction of
travel; a first idler wheel coupled to a forward portion of the
beam and rotatable with respect thereto; a second idler wheel
coupled to a rearward portion of the beam and rotatable with
respect thereto; a belt tensioner configured to tension the endless
track; a drive wheel support fixed to the suspension frame; a drive
wheel rotatably coupled to the wheel support and having a drive
wheel rotational axis; and a drive wheel axle rotationally coupled
to the drive wheel to drive the drive wheel in rotation; wherein
the track tensioner is disposed to tension the track about the
periphery of the drive wheel and the first and second idler wheels
without transferring tension to the drive wheel axle.
10. The tracked suspension of claim 9, wherein the drive wheel
rotational axis is disposed above and between rotational axes of
the first and second idler wheels, and further wherein the first
pivotal axis is disposed below the drive wheel rotational axis.
11. The tracked suspension of claim 10, wherein the beam extending
parallel to a direction of travel includes first and second
elongate members extending upward from the horizontal beam, each of
the first and second elongate members including a pivot at an upper
portion thereof that defines the first pivotal axis.
12. The tracked suspension of claim 11, wherein the tracked
suspension frame includes forward and rearward brackets disposed at
forward and rearward portions of the suspension frame,
respectively, wherein each bracket defines parallel mounting faces,
wherein the parallel mounting face of the forward bracket is
disposed to be fixedly mounted to the at least one suspension beam
and the parallel mounting face of the rearward bracket is disposed
to be fixedly mounted to at least another suspension beam extending
from the vehicle.
13. The tracked suspension of claim 12, wherein the wheel support
includes a sun gear and a planetary gear.
14. The tracked suspension of claim 13, wherein the wheel support
includes a ring gear driven by the planetary gear.
15. The tracked suspension of claim 14, further comprising inner
and outer drive wheel bearings to support the drive wheel in
rotation about the wheel support, wherein the ring gear, the sun
gear and the planetary gear are disposed laterally between the
inner and outer wheel bearings.
16. An agricultural tractor comprising: a front frame; an engine
fixedly mounted to the front frame; left and right front tracked
suspensions in accordance with claim 9 fixedly mounted to the front
frame; a front differential fixedly mounted to the front frame to
drive left and right front suspensions; a transmission rotationally
coupled to and driven by the engine; a rear frame pivotally coupled
to the front frame; left and right rear tracked suspensions in
accordance with claim 9 fixedly mounted to the rear frame; and a
rear differential fixedly mounted to the rear frame to drive the
left and right rear tracked suspensions.
17. The agricultural tractor of claim 16 further comprising: at
least one front left suspension beam fixedly mounted to the front
frame of the tractor and extending laterally and leftwardly away
from the tractor and adjustably and fixedly mounted to the left
front suspension to permit laterally inward and outward
adjustability with respect to the front frame; at least one front
right suspension beam fixedly mounted with respect to the front
frame of the tractor and extending laterally and rightwardly away
from the tractor and adjustably and fixedly mounted to the right
front suspension to permit laterally inward and outward
adjustability with respect to the front frame; at least one rear
left suspension beam fixed with respect to the rear frame of the
tractor and extending laterally and leftwardly away from the
tractor and adjustably and fixedly mounted to the left rear
suspension to permit laterally inward and outward adjustability
with respect to the rear frame; at least one rear right suspension
beam fixed with respect to the rear frame of the tractor and
extending laterally and rightwardly away from the tractor and
adjustably and fixedly mounted to the right rear suspension to
permit laterally inward and outward adjustability with respect to
the rear frame.
Description
FIELD OF THE INVENTION
[0001] The invention relates generally to tracked vehicles having
adjustable suspensions. More particularly, it relates to
agricultural tractors with tracked suspensions having lateral
adjustability and internal track strain absorption.
BACKGROUND OF THE INVENTION
[0002] Tracked vehicles have been provided for use in agricultural
operations that provide a fixed track width. One of the reasons the
tracked width is fixed is because the drive axle extending from the
vehicle and coupled to the drive wheel is neither easily removable
or adjustable since it must be strong enough to resist bending
forces applied to it by the track spring tension. It is an object
of this invention to provide an agricultural tractor that is more
easily adjusted for lateral track width. It is an object of this
invention to provide such a tractor by absorbing track tension
stresses within the tracked suspension itself, and not transmitting
them to the drive axle.
SUMMARY OF THE PRESENT INVENTION
[0003] In accordance with the first embodiment of the invention, a
tracked suspension for a work vehicle is provided including an
endless track, a suspension frame configured to be slidably and
fixedly mounted to at least one suspension beam extending from a
frame of the vehicle, a beam extending parallel to a direction of
travel and pivotally coupled to the suspension frame about a first
pivotal axis substantially perpendicular to the direction of
travel, a first idler wheel coupled to a fore portion of the beam
and rotatable with respect thereto, a second idler wheel coupled to
a rearward portion of the beam and rotatable with respect thereto,
a belt tensioner configured to tension the endless track, a drive
wheel support fixed to the suspension frame, a drive wheel
rotatably coupled to the drive wheel support and having a drive
wheel rotational axis, and a drive wheel axle rotationally coupled
to the drive wheel to drive the drive wheel in rotation, wherein
the track tensioner is disposed to tension the track about the
periphery of the drive wheel and the first and second idler wheels
without transferring tension to the drive wheel axle.
[0004] Other principal features and advantages of the invention
will become apparent to those skilled in the art upon review of the
following drawings, the detailed description and the appended
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a perspective view of an agricultural tractor in
accordance with the present invention having left and right front
and left and right rear tracked suspensions, each supported on
beams extending from the tractor;
[0006] FIG. 2 is a top view of the tractor of FIG. 1, showing the
track arrangement of the tracked suspensions, in an extended and
retracted position, together with the differentials and
transmission;
[0007] FIG. 3 is an exploded perspective view of a typical tracked
suspension of the tractor of FIGS. 1 and 2;
[0008] FIG. 4 is a side view of a typical tracked suspension of the
tractor of FIGS. 1-3 from the tractor side of the suspension;
[0009] FIG. 5 shows a partial cross-sectional view of a drive wheel
and drive wheel support for a typical suspension of the tractor of
FIGS. 1-4; and
[0010] FIG. 6 is a partial cross-sectional view of an idler beam
and associated idler wheels and roller wheels.
[0011] Before explaining at least one embodiment of the invention
in detail it is to be understood that the invention is not limited
in its application to the details of construction and the
arrangement of the components set forth in the following
description or illustrated in the drawings. The invention is
capable of other embodiments or being practiced or carried out in
various ways. Also, it is to be understood that the phraseology and
terminology employed herein is for the purpose of description and
should not be regarded as limiting.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0012] Referring to FIGS. 1-6, an agricultural tractor 10 is
illustrated supported by four tracked suspensions 12, 14, 16, 18.
Each of these suspensions is slidably mounted on two associated
beams 20, extending laterally outward from the vehicle at each
suspension point. The beams are preferably disposed in a
fore-and-aft arrangement such as that shown from right front
suspension 12 in FIG. 1.
[0013] Suspensions 12, 14, 16, 18 are each driven by drive axles
36, 38, 40, 42. The left front and right front suspensions are
coupled to a front frame 44, the left rear and right rear
suspensions are coupled to a rear frame 46. The left and right
front suspension beams are fixed with respect to and extend from
front frame 44. The left and right rear suspension beams are fixed
with respect to and extend from rear frame 46. A middle frame 48 is
provided that is pivotally coupled to both front frame 44 and rear
frame 46 via two articulation joints 50, 52. Front articulation
joint 50 pivotally couples front frame 44 and middle frame 48 and
permits pivotal movement between the two, primarily in a horizontal
plane. Rear articulation joint 52 is coupled between middle frame
48 and rear frame 46 and permits pivotal motion between middle
frame 48 and rear frame 46, primarily in a horizontal plane.
[0014] Engine 54 is fixedly mounted to front frame 44 and drives
the tractor 10. It is coupled via a drive shaft 56 to transmission
58 which is driven by engine 54. Transmission 58, in turn, drives
front drive shaft 60 and rear drive shaft 62. Front drive shaft 60
is coupled between transmission 58 and front differential 64 and
transmits power from transmission 58 to front differential 64 to
drive front differential 64. Rear drive shaft 62 is similarly
coupled between transmission 58 and rear differential 66 and
transmits power from transmission 58 to rear differential 66.
[0015] Front differential 64 drives laterally opposed left front
suspension 12 and right front suspension 14. Rear differential 66
drives laterally opposed left rear suspension 16 and right rear
suspension 18. Each of the three drive shafts 56, 60, 62 includes a
flexible coupling 68, 70, 72 disposed in its length to permit
relative motion between the differentials and the transmission and
between the transmission and the engine to allow the front, middle
and rear frames to pivot with respect to each other about their
flexible couplings.
[0016] Each of the four tracked suspensions 12, 14, 16, and 18 are
preferably the same, a single example of which is illustrated in
FIGS. 3-6. The discussion below is directed to single suspension,
but applies equally to all four. The tracked suspensions on the
left side are mirrored on the right side of the vehicle. Internal
details of the front and rear differentials are disclosed in the
application entitled "Track Vehicle Track Width Adjustment,"
Attorney Docket No. 018483/0513, filed contemporaneously herewith
and incorporated herein by reference for all that it teaches.
[0017] Each tracked suspension includes a drive wheel assembly 100
mounted on an idler wheel carriage 102 which supports the idler and
roller wheels. The idler wheel carriage is slidably supported on
two beams 20 that extend laterally from the front or rear frame of
the vehicle. Idler wheel carriage 102 is pivotally coupled to idler
wheel assembly 104.
[0018] There are two beams extending from the left front of the
vehicle which support the left front tracked suspension, two beams
that extend from the from the right front of the vehicle that
support the right front tracked suspension, two beams that extend
from the left rear of the vehicle that support the left rear
tracked suspension, and two beams that extend from the right rear
of the vehicle that support the right rear tracked suspension.
[0019] The drive wheel assembly includes a drive wheel 106
rotationally supported on a drive wheel support 108. Drive wheel
106 includes a rim 110 that is bolted to drive wheel hub 112 which
is supported in rotation by drive wheel support 108. Drive wheel
support 108 is fixedly mounted to idler wheel carriage 102. Drive
wheel 106 is supported on bearings 114, 116 and 118 which permit
the drive wheel to rotate with respect to drive wheel support 108.
Drive wheel 106 is driven by ring gear 121 disposed between and
fixedly mounted to inner and outer portions of drive wheel hub 112.
Drive wheel support 108 is fixedly mounted to idler wheel carriage
102 both on the inboard side and the outboard side of drive wheel
106. On the inboard side, a downwardly extending flange 120 of
drive wheel support 108 is fixedly mounted to inboard carriage
support 122. On the outboard side, a cylindrical portion 124 of
drive wheel support 108 is fixedly mounted to a plate 126 extending
upward from outboard carriage support 128. Drive wheel support 108
also supports an outboard end of drive axle 130 in rotation. The
outboard end of drive axle 130 is rotationally coupled to flexible
coupling 132, which in turn is coupled to stub axle 134. A sun gear
136 is fixedly mounted to stub axle 134 and engages a plurality of
planetary gears 138 (only one shown for convenience) that are
supported in rotation by drive wheel support 108. Planetary gears
138, in turn, engage and drive ring gear 121. In this manner, when
drive axle 130 is rotated, it drives sun gear 136 in rotation,
which drives planetary gears 138 in rotation, which drive ring gear
121 and therefore drive drive wheel hub 112 in rotation.
[0020] Rim 110 includes to axially extending flanges 140 and 142
that support and drive track 144. A recess 146 is located between
the two flanges and receives lugs 148 extending inwardly from an
inner surface of track 144. A plurality of axially extending rods
150 extend between and are fixed at both ends with respect to
axially extending flanges 140 and 142 and across the recess. Each
of these rods 150 engage lugs 148 and drive track 144 about the
periphery of drive wheel 106.
[0021] Idler wheel carriage 102 includes two laterally extending
members (or brackets) 152, 154 that are coupled to beams 20
extending from the vehicle's frame. Inboard and outboard carriage
supports 122 and 128 extend between and are fixedly mounted to
laterally extending members 152 and 154. Carriage support 122 is
disposed inboard of drive wheel 106 and carriage support 128 is
disposed outboard of drive wheel 106. Carriage supports 122 and 128
define carriage pivots 156 and 158, respectively, which pivotally
support idler beam 160 of idler wheel assembly 104. In this manner,
idler beam 160 is permitted to rotate about a substantially
horizontal pivotal axis 161 that extends laterally with respect to
the vehicle and is defined by carriage pivots 156 and 158. This
pivotal axis is preferably disposed below the drive wheel's
rotational axis, and above and between the rotational axes of idler
wheels 162 and 164. The pivotal axis preferably intersects the
drive wheel. Each of the carriage pivots includes an inboard and
outboard pin supports 166, 168 having holes through which pins 170
are inserted. Pins 170 extend laterally with respect to the
vehicle, and are substantially coaxial. Pins 170 are supported at
their inner and outer ends by their associated inboard and outboard
supports. Each of the laterally extending members 152 and 154 have
a plurality of holes 172 through which bolts 174 are inserted.
Similarly spaced holes 176 are provided on beams 20 to receive
these bolts. To adjust the position of the tracked suspension with
respect to the vehicle, the bolts are removed and the suspension is
slid inward or outward on beams 20 until a new set of holes on the
laterally extending members and the beams are aligned. Surfaces 178
and 180 on laterally extending members 152, 154 are substantially
parallel where intersected by a horizontal plane or planes and mate
with similar parallel surfaces 182, 184 on beams 20. At this point,
the bolts are been reinserted in the newly aligned holes and
tightened. To make this adjustment relatively trouble free,
alignment marks are preferably provided on at least one beam and
its corresponding tracked suspension for each of the four
suspensions of the vehicle.
[0022] Idler wheel assembly 104 includes an elongate horizontally
extending idler beam 160 which supports idler wheels 162 and 164
(and roller wheels 186 and 188) in rotation. Pivot ears 191 and 193
are fixedly mounted to idler beam 160 and extend upwardly and
outwardly to pivotally engage carriage pivots 158 and 156,
respectively. In this manner, idler wheel assembly 104 and its two
idler and two roller wheels, pivot with respect to drive wheel 106
about the pivotal axis defined by carriage pivots 156 and 158.
[0023] Idler wheels 162 and 164 are biased away from each other by
coil spring 190 disposed between the idler wheels and above idler
beam 160. Both idler wheels are in the form of two discs spaced
apart from each other and sharing a common rotational axis. A
pivotal link 192 is pivotally coupled to an end of idler beam 160.
Idler wheel 164 is rotationally coupled to pivotal link 192, having
a disk disposed on either side of pivotal link 192. An elongate
member 194 is pivotally coupled to an upper end of pivotal link 192
and biases pivotal link 192 outward with respect to idler beam 160.
The inner end of elongate member 194 abuts a first end of spring
190 which pushes the elongate member outward with respect to idler
beam 160. A second end of spring 190 abuts piston rod 196 which
extends from and is biased toward spring 190 by hydraulic cylinder
198. By filling hydraulic cylinder 198 with hydraulic fluid, piston
rod 196 is forced out of the cylinder and toward the spring,
compressing this spring and biasing idler wheel 164 outward. In
this manner, track 144, which extends about the periphery of idler
wheel 162, idler wheel 164, and drive wheel 106, can be
appropriately tensioned or pre-loaded. Spring 190 is shrouded by
spring housing 200 which extends around the outside of spring 190
on an upper surface of idler beam 160 and keeps dirt and other
contaminants from filling the coils of spring 190. Hydraulic
cylinder 198 and spring housing 200 are fixedly mounted to an upper
surface of idler beam 160. Idler wheel 162 is supported by the
other end of idler beam 160 and rotates with respect thereto.
Roller wheels 186 and 188 are also mounted on bearings to idler
beam 160 for rotation with respect to idler beam 160. These wheels
are disposed between idler wheels 162 and 164 and are also in the
form of two discs, one disposed on either side of idler beam
160.
[0024] Thus, it should be apparent that there has been provided in
accordance with the present invention an improved tracked
suspension that fully satisfies the objectives and advantages set
forth above. Although the invention has been described in
conjunction with specific embodiments thereof, it is evidence that
many alternatives, modifications and variations will be apparent to
those skilled in the art. Accordingly, it is intended to embrace
all such alternatives, modifications and variations that fall
within the spirit and broad scope of the appended claims.
* * * * *