Independent rear suspension system for an all terrain vehicle

Abstract

An independent rear suspension for a vehicle having a chassis and a pair of rear wheels including a pair of IRS units. Each IRS unit includes an X-shaped lower control arm with a forward pivot connection to the chassis in front of the centerline of the driven sprocket and a rearward pivot connection behind the centerline, and a camber link connected to the chassis at a single pivot connection behind the centerline. Each IRS unit also includes a shock absorber coupled with an anti-sway bar to the lower control arm at a mount, and including a secondary spring in series with a main spring.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an ATV.

FIG. 2 is a perspective view of a partially disassembled ATV embodying features of the present invention.

FIG. 3 is a perspective view of a drive mechanism and independent rear suspension according to the present invention.

FIG. 4 is a partially fragmented, side elevational view of portions of the drive mechanism and independent rear suspension of FIG. 3.

FIG. 5 is a partially fragmented, perspective view of an independent rear suspension according to principles of the present invention.

FIG. 6 is a side, elevational view of the suspension of FIG. 5.

FIG. 7 is a combination side elevational and top plan view of a lower control arm component of the suspension of FIG. 5.

FIG. 8 is a rear, elevational view of the ATV of FIG. 1.

FIG. 9 is a side, elevational view of a shock absorber according to the present invention.

FIG. 10 is a partially fragmented, cross-sectional view taken along line 10-10 of FIG. 5.

FIGS. 11( a)-(c) are side, elevational views of the shock absorber of FIG. 9 in various positions.

Claims

1. An independent rear suspension for a vehicle having a chassis and a pair of rear wheels, the suspension including: a first unit movably coupled between the chassis and one of the wheels; anda second unit movably coupled between the chassis and another of the wheels;wherein the first and second units each include a lower control arm and a camber link, the camber links each being coupled to the chassis at a single pivot connection.

2. The suspension of claim 1 wherein each unit further includes a knuckle connecting the lower control arm and the camber link, the knuckle being configured for connection to a wheel hub.

3. The suspension of claim 2 wherein each camber link includes a first end configured for pivotal coupling to a corresponding knuckle about a first pin, and a second end configured for pivotal coupling to a corresponding single pivot connection about a second pin.

4. The suspension of claim 3 wherein each camber link further includes an elongated body portion extending between the first end and the second end.

5. An independent rear suspension for a vehicle having a chassis and a pair of rear wheels, the suspension including: a pair of lower control arms extending between the wheels and the chassis; anda pair of camber links extending between the wheels and the chassis;wherein the control arms each include a first end configured to pivotally support a knuckle coupled between the control arm and a corresponding camber link,a central body,a forward link extending from the central body to a forward pivot connection on the chassis,a rearward link extending from the central body to a rearward pivot connection on the chassis, anda pair of cross links extending between the forward link and the rearward link, thereby forming a substantially X-shaped interconnection between the forward link and the rearward link.

6. The suspension of claim 5 wherein the first end includes a pair of supports coupled to the knuckle by a pin and joined together by a web.

7. The suspension of claim 6 wherein the central body includes a brace that extends substantially parallel to the pin and forms an outboard opening with the pair of supports and the web.

8. The suspension of claim 5 wherein the central body includes a mount having an opening for receiving a fastener that couples a shock absorber and an anti-sway bar link to the control arm.

9. The suspension of claim 5 wherein the cross links form a forward opening with the forward link, a rearward opening with the rearward link, and a central opening with the central body.

10. The suspension of claim 5 wherein the forward pivot connection is located in front of a vertical plane passing through a center line of a driven sprocket of the vehicle and the rearward pivot connection is located behind the vertical plane.

11. The suspension of claim 10 wherein the camber links each include a first end configured for pivotal coupling to a corresponding knuckle, and a second end configured for pivotal coupling to a corresponding single pivot connection on the chassis.

12. The suspension of claim 11 wherein the single pivot connection is located behind the vertical plane.

13. An independent suspension for a vehicle, including: a lower control arm extending between a wheel and a chassis of the vehicle; anda shock absorber extending between the chassis and the lower control arm, the shock absorber including a cylinder,a piston,a main spring, anda secondary spring in series with the main spring, the secondary spring being substantially fully compressed whenever the main spring is compressed.

14. The suspension of claim 13 wherein the secondary spring is disposed about the cylinder between a first preload ring and an upper collar, and the main spring is disposed between the upper collar and a lower collar.

15. The suspension of claim 13 further including an anti-sway bar, the piston and the anti-sway bar being coupled to the lower control arm at a common mount.

16. The suspension of claim 15 wherein the piston includes a bracket having openings that align with an opening in the mount and a hole in the anti-sway bar.

17. The suspension of claim 16 further including a fastener extending through the openings in the bracket and the mount, and the hole in the anti-sway bar to connect the shock absorber and the anti-sway bar to the lower control arm.

18. The suspension of claim 13 wherein the main spring has a spring rate that is higher than a spring rate of the secondary spring.

19. The suspension of claim 13 wherein the secondary spring is partially extended when the shock absorber is in a full rebound position.

20. The suspension of claim 14 wherein the cylinder includes threads, the first preload ring being movable on the threads to adjust an amount of compression of the main spring.

21. The suspension of claim 20 further including a second preload ring being movable on the threads to engage the first preload ring to retain the first preload ring in a desired position.

22. The suspension of claim 13, wherein the shock absorber further includes an adjustment mechanism configured to adjust a damping characteristic of the shock absorber, the adjustment mechanism including a knob configured to adjust the size of an orifice within the shock absorber.