Compact track loader with lockable suspension system

Patent metadata

Field	Value
Publication number	US-9694861-B2
Application number	US-201514877355-A
Country	US
Kind code	B2
Filing date	Oct 7, 2015
Priority date	Oct 7, 2015
Publication date	Jul 4, 2017
Grant date	Jul 4, 2017

Abstract

A suspension assembly of a work machine being movable in a forward direction. The work machine includes a frame, an undercarriage supporting the frame and at least one ground-engaging track. The suspension assembly includes a torsion assembly having an axle, a torsion bar adapted to be fixedly coupled to the frame, and an axle arm coupled at one end to the axle and at an opposite end thereof to the torsion bar. A locking arm has a first end and a second end, where the first end is coupled to the axle arm. A hydraulic actuator is coupled to the second end of the locking arm. The hydraulic actuator is operably controlled between a locked configuration and an unlocked configuration. In the unlocked configuration, the axle arm is pivotable relative to the frame, and in the locked configuration the axle arm is restricted from pivoting relative to the frame.

First claim

The invention claimed is:

1. A suspension assembly of a work machine being movable in a forward direction, the work machine including a frame, an undercarriage supporting the frame, at least one boom arm pivotally coupled to the frame, and at least one ground-engaging track, comprising:
a torsion assembly, the torsion assembly including an axle adapted to be coupled to the undercarriage, a torsion bar adapted to be fixedly coupled to the frame, and an axle arm coupled at one end to the axle and at an opposite end thereof to the torsion bar;
a locking arm having a first end and a second end, the first end being coupled to the axle arm; and
a hydraulic actuator coupled to the second end of the locking arm, the hydraulic actuator being operably controlled between a locked configuration and an unlocked configuration;
wherein:
in the unlocked configuration, the axle arm is pivotable relative to the frame; and
in the locked configuration, the axle arm is restricted from pivoting relative to the frame.

2. The suspension assembly of claim 1 , wherein in the unlocked configuration, the torsional assembly is structured to absorb vibrational inputs.

3. The suspension assembly of claim 1 , further comprising a bogie roller suspension assembly for absorbing vibrational inputs, the bogie roller suspension assembly including at least two pairs of bogie wheels.

4. The suspension assembly of claim 1 , wherein the axle arm extends downward from the frame at an angle between 180 and 270 degrees from the forward direction.

5. The suspension assembly of claim 1 , further comprising a second torsion assembly disposed near a rear end of the work machine, the second torsion assembly including a second axle coupled to the undercarriage, a second torsion bar fixedly coupled to the frame, and a second axle arm coupled at one end to the second axle and at an opposite end thereof to the second torsion bar.

6. The suspension assembly of claim 5 , wherein the first axle arm has a first length and the second axle arm has a second length, where the first length is less than the second length.

7. The suspension assembly of claim 5 , wherein:
the first axle arm extends downward from the frame at an angle between 180 and 270 degrees from the forward direction; and
the second axle arm extends downward from the frame at an angle between 180 and 270 degrees from the forward direction.

8. The suspension assembly of claim 5 , further comprising a first axle and a second axle, the first axle arm being coupled to the first axle about a first axle axis and the second axle arm being coupled to the second axle about a second axle axis;
wherein, the first axle arm is coupled to the frame and locking arm about a first torsion axis, and the second axle arm is coupled to the frame about a second torsion axis;
wherein, a first axis passes through a length of the first axle arm and intersects the first axle axis and the first torsion axis, and a second axis passes through a length of the second axle arm and intersects the second axle axis and the second torsion axis;
further wherein, the first axis and the second axis intersect to define an instant center, the instant center continuously being located at a location in front of the machine.

9. The suspension assembly of claim 8 , wherein in the unlocked configuration:
the instant center is movable along an arc-shaped path based on a free state, an unloaded state, and a loaded state of the first and second axle arms; and
a center of gravity of the machine is movable along a path defined by a pitch angle, the pitch angle being less than 2 degrees.

10. A work machine being movable in a forward direction of travel, comprising:
a frame having a front end, a rear end, a first side, and a second side;
at least one boom arm pivotably coupled to the frame;
an undercarriage supporting the frame, the undercarriage including at least one ground-engaging track positioned around the undercarriage;
a first torsion assembly disposed near the front end and adapted to reduce vibrational inputs, the first torsion assembly including a first axle coupled to the undercarriage, a torsion bar fixedly coupled to the frame, and a first axle arm coupled at one end to the first axle and at an opposite end thereof to the torsion bar;
a second torsion assembly disposed near a rear end of the work machine and adapted to reduce vibrational inputs, the second torsion assembly including a second axle coupled to the undercarriage, a second torsion bar fixedly coupled to the frame, and a second axle arm coupled at one end to the second axle and at an opposite end thereof to the second torsion bar;
a locking arm having a first end and a second end, the first end being coupled to the first axle arm; and
a hydraulic actuator coupled to the second end of the locking arm, the hydraulic actuator being operably controlled between a locked configuration and an unlocked configuration;
wherein:
in the unlocked configuration, the first axle arm is pivotable relative to the frame; and
in the locked configuration, the first axle arm is restricted from pivoting relative to the frame.

11. The work machine of claim 10 , wherein:
the first torsion assembly comprises one torsion assembly on the first side of the frame and another torsion assembly on the second side thereof;
the locking arm comprises a first locking arm and a second locking arm, the first locking arm being coupled to the first axle arm on the first side and the second locking arm being coupled to the first axle arm on the second side; and
the hydraulic actuator comprises a first hydraulic actuator and a second hydraulic actuator, the first hydraulic actuator being coupled to the first locking arm and the second hydraulic actuator being coupled to the second locking arm.

12. The work machine of claim 10 , wherein the first axle arm has a first length and the second axle arm has a second length, where the first length is less than the second length.

13. The work machine of claim 10 , wherein:
the first axle arm extends downward from the frame at an angle between 180 and 270 degrees from the forward direction; and
the second axle arm extends downward from the frame at an angle between 180 and 270 degrees from the forward direction.

14. The work machine of claim 10 , further comprising a first axle and a second axle, the first axle arm being coupled to the first axle about a first axle axis and the second axle arm being coupled to the second axle about a second axle axis;
wherein, the first axle arm is coupled to the frame and locking arm about a first torsion axis, and the second axle arm is coupled to the frame about a second torsion axis;
wherein, a first axis passes through a length of the first axle arm and intersects the first axle axis and the first torsion axis, and a second axis passes through a length of the second axle arm and intersects the second axle axis and the second torsion axis;
further wherein, the first axis and the second axis intersect to define an instant center, the instant center continuously being located at a point forward of the machine.

15. The work machine of claim 14 , further comprising a center of gravity of the machine defined at a location on the machine, wherein in the unlocked configuration the instant center is movable along a curved path and the center of gravity is movable along a path defined by a pitch angle, the pitch angle being less than 2 degrees.

16. The work machine of claim 10 , further comprising:
a controller;
a main control valve in fluid communication with the hydraulic actuator;
a solenoid va

Assignees

• Deere & Co

Inventors

• Thomas Galen C
• Whiteman Steven R
• Fleischmann Steve G
• Gross Justin C
• Wentzloff James

Classifications

• E02F9/2025

  Particular purposes of control systems not otherwise provided for (E02F3/16, E02F3/26, sub-groups of E02F3/43, E02F3/651, sub-groups of E02F3/84, E02F3/907, E02F5/145 take precedence) · CPC title

• E02F3/3414

  the arms being pivoted at the rear of the vehicle chassis, e.g. skid steer loader · CPC title

• B62D55/1083 Primary

  Torsion-bar springs · CPC title

• E02F9/2207

  for reducing or compensating oscillations · CPC title

• E02F9/02

  Travelling-gear, e.g. associated with slewing gears ({drives therefor E02F9/20}; for motor vehicles B60B, B60G; undercarriages for locomotives or railroad cars B61F; track-laying vehicles B62D; for cranes B66C23/18) · CPC title