SUSPENSION SYSTEM FOR A TRACKED VEHICLE

• US 20040099451A1
• Filed: 11/22/2002
• Published: 05/27/2004
• Est. Priority Date: 05/23/2002
• Status: Active Grant

• Current Assignee: WesternGeco LLC
• Original Assignee: WesternGeco LLC
• Inventors: Nagorcka, James A., Allen, Lyal
• Granted Patent: US 6,810,975 B2
• Time in Patent Office: Days
• US Class Current: 180/9.5
• CPC Class Codes: B62D 55/084 Endless-track units or carriages mounted separably, adjustably or extensibly on vehicles, e.g. portable track units B62D55/07 takes precedence
• CPC Class Codes: B62D 55/0842 Tracked vehicle with track carriages suspended on three points, e.g. by an equaliser bar

Abstract

A suspension system for a tracked vehicle, preferably having rubber tracks. The track assembly is mounted on a pivot shaft such that it can oscillate about the axis of the pivot shaft. The suspension system allows the track assembly to move vertically relative to the vehicle chassis to compensate for uneven terrain. For instance the track assembly can compensate for depressions or bumps in the terrain and preclude the chassis of the vehicle from tilting with each minor change in the terrain. In addition, the track assembly movement in the vertical direction provides a much smoother ride than do traditional tracked vehicles. The suspension system of the present invention is provided for use with a pair of track assemblies.

Claims

1. A track suspension system for a vehicle, comprising:

a main axle beam having first and second beam ends forming pivot shafts;

at least one attachment beam extending from the main axle beam toward the forward of the vehicle;

a track assembly pivotally connected to each of the pivot shafts;

a vehicle chassis coupled by a spherical bearing to the at least one attachment beam;

a first shock absorbing member having a first end coupled by a spherical bearing to the main axle beam near the first beam end and a second end coupled by a spherical bearing to the chassis;

a second shock absorbing member having a first end coupled by a spherical bearing to the main axle beam near the second beam end and a second end coupled by a spherical bearing to the chassis; and

a centralizer coupled between the main axle beam and the chassis.

2. The system of claim 1, wherein the spherical bearing that couples the vehicle chassis to the attachment beam is positioned along the centerline of the vehicle.

3. The system of claim 1, wherein the centralizer keeps the main axle beam substantially centered with the centerline of the vehicle.

4. The system of claim 1, wherein the centralizer comprises a side location rod having a first rod end coupled by a spherical bearing to the main axle beam and a second rod end coupled by a spherical bearing to the chassis.

5. The system of claim 1, wherein the centralizer comprises a side location rod having a first rod end coupled by a spherical bearing to the main axle beam near the first beam end and a second rod end coupled by a spherical bearing to the chassis near the second beam end.

6. The system of claim 1, wherein the chassis is supported primarily by the first and second shock absorbing members.

7. The system of claim 1, wherein the first and second shock absorbing members are shock absorbers.

8. The system of claim 7, wherein the shock absorbers are double-sided shock absorbers.

9. The system of claim 1, wherein the shock absorbing members are displacement cylinders.

10. The system of claim 9, further comprising dedicated accumulators in fluid communication with each of the displacement cylinders.

11. The system of claim 10, wherein each accumulator has a gas chamber and a working fluid chamber that are maintained at the same pressure.

12. The system of claim 11, wherein the working fluid fills the working fluid chamber and the displacement cylinder.

13. The system of claim 11, wherein the gas chamber is charged with gas at sufficient pressure to support the static weight of the vehicle at a position about halfway through the displacement cylinder range of extension.

14. The system of claim 9, further comprising a hydraulic pressure source in fluid communication with the displacement cylinders for extending or retracting the cylinders.

15. The system of claim 1, wherein the first and second shock absorbing members are air springs.

16. The system of claim 1, wherein the track assembly comprises:

a track frame having first and second ends, wherein the track frame is mounted for rocking movement on the pivot shaft at a location between the first and second ends;

a drive wheel positioned adjacent and above the pivot shaft;

an idler wheel link pivotally attached to the first end of the track frame, extending upwardly therefrom and terminating in an upward end;

a first idler wheel mounted for rotation on the upper end of the idler wheel link;

a second idler wheel mounted for rotation on the second end of the track frame;

a continuous track engaging the drive wheel, the first idler wheel, and the second idler wheel; and

take-up means mechanically linking the first idler wheel and link and the track frame for biasing the upper end of the idler wheel link away from the pivot shaft in direct reaction to the rocking motion of the track frame away from the horizontal so as to move the first idler wheel away from the pivot shaft and thereby maintain a substantially constant circumference around the idler wheels and drive wheel.