HYDRAULIC STABILIZING UNIT FOR STEER AXLES

Abstract

The present invention relates to a new hydraulic stabilizing unit that can be mounted onto any self-steering axle assembly that utilises a pneumatic stabilizing system. The hydraulic stabilizer works in conjunction with the pneumatic stabilizer to eliminate a “dead zone” of the pneumatic system to avoid wheel shimmy and hop conditions associated with out of specification caster angles on the axle.

Claims

1. A self-steering axle comprising: a main axle beam which interacts with a tie rod through a pair of lever arms rockingly coupled to the main axle beam for rocking about a lever axis generally orthogonal to said tie rod and said main axle beam; each said lever arm having a tie rod end opposite a spring end with said lever axis therebetween; said tie rod ends receiving translational input from said tie rod to cause said lever arms to rock about said lever axis; said spring ends acting against a resilient member mounted therebetween to resist said translational input; and a double acting hydraulic dampener connecting said lever arms between said lever axis and said tie rod ends to resist movement of said tie rod ends of said lever arms toward and away from each other.

2. A method of stabilizing a self-steering axle having a main axle beam which interacts with a tie rod through a pair of lever arms rockingly coupled to the main axle beam for rocking about a lever axis generally orthogonal to said tie rod and said main axle beam, each said lever arms having a tie rod end opposite a spring end with said lever axis therebetween, said tie rod ends receiving translational input from said tie rod to cause said lever arms to rock about said lever axis, said spring ends acting against a resilient member mounted therebetween to resist said translational input, said method comprising: connecting said lever arms with a double acting hydraulic dampener between said lever axis and said tie rod ends to resist movement of said tie rod ends of said lever arms toward and away from each other.

Description

DESCRIPTION OF DRAWINGS

[0010] Preferred embodiments of the present invention are described below with reference to the accompanied drawings in which:

[0011] FIG. 1 is an enlarged perspective view of a steer axle assembly incorporating hydraulic dampening system according to the present invention;

[0012] FIG. 2 is a perspective view corresponding to a central portion of FIG. 1 showing the stabilizing assembly;

[0013] FIG. 3 is a perspective view of a left hand bracket for attachment to a left hand lever arm according to the present invention;

[0014] FIG. 4 is a perspective view of a right hand bracket for attachment to a right hand lever arm; and

[0015] FIG. 5 is an exploded view of the hydraulically stabilized steer axle according to the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0016] The hydraulic stabilizing unit of the present invention can be mounted on any steer axle that uses a pneumatic centering stabilizer 12 with lever arms 7 and 8 coupled to a tie rod lock plate 16 at a respective tie rod end 27 and 28 of each of the lever arms 7 and 8. The lever arms are in turn coupled to the tie rod 14 via the tie rod lock plate 16. A left stabilizing bracket 2 and a right stabilizing bracket 3 are welded onto the left lever arm 7 and the right lever arm 8 respectively. A hydraulic stabilizing unit 1 is bolted into the left stabilizing bracket 2 and the right stabilizing bracket 3 using hydraulic stabilizing unit bolts 4, washers 5 and nuts 6.

[0017] As the trailer enters a turn the tires which are in contact with the road receive pressure from the side. Once the pressure overcomes the force from the air pressure in the pneumatic centering stabilizer 12, the kingpin assemblies 22 will rotate about the ends 24. As the kingpin assemblies 22 rotate, the tie rod 14 starts to move laterally. The tie rod lock plate 16 moves the lever arms 7 and 8 laterally. The lever arms 7 and 8 rotate about respective lever arm axes 19 coaxial with lever arm pivot bolts 9 and nuts 10. As lever arms 7 and 8 move, they exert pressure on the pneumatic centering stabilizer 12, thus squeezing the pneumatic centering unit 12. As the trailer straightens out when it comes out of a turn the air pressure will return the pneumatic centering unit 12 to its normal shape and align the steer axle with a line of travel of the trailer.

[0018] The hydraulic stabilizing unit 1 dampens the movement of the pneumatic centering unit making it “hop” less as it moves. The hydraulic stabilizing unit 1 is double acting in that it resists both extension and retraction forces and is designed to keep the lever arms 7 and 8 in contact with the tie rod lock plate 16.

[0019] The foregoing description of the preferred embodiments and examples of the apparatus and process of the invention have been presented to illustrate the principles of the invention and not to limit the invention to the particular embodiments illustrated. It is intended that the scope of the invention be defined by all of the embodiments encompassed within the claims and/or their equivalents. [0020] 1. Hydraulic Stabilizing Unit [0021] 2. Left Hand Stabilizing Bracket [0022] 3. Right Hand Stabilizing Bracket [0023] 4. Hydraulic Stabilizing Unit Bolt [0024] 5. Washer [0025] 6. Nut [0026] 7. Left Hand Lever Arm [0027] 8. Right Hand Lever Arm [0028] 9. Lever Arm Pivot Bolt [0029] 10. Lever Arm Pivot Nut [0030] 11. Tie Rod Guide Assembly [0031] 12. Pneumatic Centering Unit [0032] 13. Tie Rod Lock Plate Assembly [0033] 14. Tie Rod [0034] 15. Steer Axle [0035] 16. Tie Rod Lock Plate [0036] 17. Tie Rod End of Left Hand Lever Arm [0037] 18. Tie Rod End of Right Hand Lever Arm [0038] 19. Lever Arm Axis [0039] 22. Kingpin Assemblies [0040] 24. Ends of Axle Main Beam [0041] 27. Spring End of Left Hand Lever Arm [0042] 28. Spring End of Right Hand Lever Arm