Steering column assemblies

Patent metadata

Field	Value
Publication number	US-10378577-B2
Application number	US-201515529589-A
Country	US
Kind code	B2
Filing date	Nov 25, 2015
Priority date	Nov 25, 2014
Publication date	Aug 13, 2019
Grant date	Aug 13, 2019

Abstract

A telescopic steering column assembly comprising an upper shroud portion and a lower shroud portion is supported by the shroud portions through a support bearing assembly that acts between an upper portion of the telescopic steering shaft and a lower portion of the shroud that move relative to one another axially during telescopic adjustment, in which the support bearing assembly comprises: a set of bearings elements, a bearing cage comprising a sleeve that is located between an outer face of the upper shaft and an inner face of the lower shroud portion and is free to move axially relative to one of the upper shaft and the lower shroud, the cage including pockets that extend through the sleeve, each pocket loosely locating a bearing element such that a portion of the bearing element extends through the cage to engage with a first bearing race surface defined by one of the upper shaft and the shroud, an annular bearing race having a tapered second bearing race surface that engages the bearing elements located between the cage and the upper shaft or the cage and the lower shroud so that the annular bearing race is on the opposite side of the cage to the first bearing surface, and a biasing means which applies an axially directed thrust to the bearing elements to force them into engagement with the second bearing surface of the annular bearing race the thrust being reacted by the second bearing surface.

First claim

The invention claimed is:

1. A telescopic steering column assembly comprising an upper shroud portion and a lower shroud portion, the upper shroud portion and the lower shroud portion being able to move relatively along a common linear path during telescopic adjustment of the assembly, a telescopic steering shaft that passes through the upper shroud portion and the lower shroud portion and is supported by the upper and lower shroud portions through a support bearing assembly that acts between an upper shaft portion of the telescopic steering shaft and the lower shroud portion that move relative to one another axially during telescopic adjustment of the telescopic steering column assembly for reach, the support bearing assembly in use removing free play between the telescopic steering shaft and the upper and lower shroud portions that would otherwise occur in at least one direction orthogonal to the telescopic adjustment,
in which the support bearing assembly comprises:
a set of bearings elements,
a bearing cage comprising a sleeve that is located between an outer face of the upper shaft portion and an inner face of the lower shroud portion and is free to move axially relative to one of the upper shaft portion and the lower shroud portion, the cage including pockets that extend through the sleeve, each pocket loosely locating a bearing element such that a portion of the bearing element extends through the cage to engage with a first bearing race surface defined by one of the upper shaft portion and the lower shroud portion,
an annular bearing race having a tapered second bearing race surface that engages the bearing elements, the annular bearing race being located between the cage and the upper shaft portion or the cage and the lower shroud portion so that the annular bearing race is on the opposite side of the cage to the first bearing race surface, and
a biasing means which applies an axially directed thrust to the bearing elements to force them into engagement with the second bearing race surface of the annular bearing race, the thrust being reacted by the second bearing race surface thereby to cause the bearing elements additionally to apply a radial force onto the first bearing race surface.

2. The assembly of claim 1 , wherein the bearing elements are ball bearings that are arranged at spaced locations around the circumference of the cage.

3. The assembly of claims 1 , wherein the bearing elements are roller bearings.

4. The assembly of claims 3 , wherein end faces of the bearing elements are chamfered or tapered, with a straight or curved face, in regions thereof that contact the second bearing race surface.

5. The assembly of claim 1 , wherein the lower shroud portion forms the first bearing race surface.

6. The assembly of claim 1 , wherein the upper shaft portion forms the first bearing race surface.

7. The assembly of claim 1 , wherein the annular bearing race comprises an annular thrust ring defining two opposed tapered second bearing faces arranged respectively on opposing sides of a centre line of the ring, the bearing elements comprises ball bearings and is divided into two sets of elements with the bearings of each set arranged around a circumferential path, one set engaging one of the second bearing faces and the other set the other bearing face so that the ring is located substantially between the two sets bearing elements.

8. The assembly of claim 1 , wherein the annular bearing race comprises a thrust ring.

9. The assembly of claim 1 , wherein a spacer defining a race ring is provided that is located between the biasing means and the bearing elements, so that the biasing means acts on the bearing elements through the race ring.

10. The assembly of claim 9 , wherein the race ring includes a tapered third bearing race surface on which the bearing elements are configured to roll in use as the telescopic steering shaft is turned.

11. The assembly of claim 9 , wherein there are two race rings.

12. The assembly of claim 11 , wherein the assembly comprises end stops which hold the race rings in place on the bearing assembly.

13. The assembly of claim 12 , wherein the end stops comprise a radially extending flange or shoulder formed integral to the cage, and the other is a removable radially extending flange or shoulder secured to the cage by tabs that engage in holes or by a threaded engagement.

14. The assembly of claim 13 , wherein the spacing between the flanges or shoulders are adjustable to allow a radial load to be adjusted.

15. The assembly of claim 12 , wherein one of the end stops are removable from the support and are adjustable to enable the spacing between the end stops to be varied thereby to adjust the radial load on the bearing.

16. The assembly of claim 15 , wherein the cage is slid into the shroud and the support that bears the end stops may he located on the upper shaft portion inside the cage, a pair of bearing elements each defining a second bearing race being slid onto the sleeve, and the biasing means acting between the end stop and one of the pair of bearing elements.

17. The assembly of claim 15 , wherein the support is fixed in position axially relative to the upper shaft portion or lower shroud portion.

18. The assembly of claim 12 , wherein the end stops, abutment rings or race rings comprise components fixed axially onto the lower shroud portion.

19. The assembly of claim 1 , wherein the annular bearing race comprises at least one race ring.

20. The assembly of claim 1 , wherein the bearing elements are roller elements with tapered ends, the roller elements are located at spaced positions around a circumference of the upper shaft portion with the cage slid onto the upper shaft portion so that the bearings contact the upper shaft portion, and the annular bearing second race comprises a pair of rings that each have a tapered face defining a second bearing surface, the rings being located at a respective end of the rollers, a support being provided that fits around the rings and defines a pair of end stops, the two rings and the bearings being located between the end stops, and the biasing means acting between at least one end stop and one of the ends of the bearings.

21. The assembly of claim 1 , wherein the bearing elements are roller elements with tapered ends and the roller elements are located at spaced positions around a circumference of the upper shaft portion with the cage slid onto the upper shaft portion so that the bearing elements contact the upper shaft portion, and the annular bearing race comprises a pair of rings that each have a tapered face defining a second bearing race surface, the rings being located at a respective end of the rollers, one race ring and the bearing elements being located between the end stops, and the biasing means acting between at least one end stop and one of the ends of the bearing elements, wherein the end stops are an abutment ring and a second race ring fixed to the inner surface of the lower shroud portion by press fitting.

Assignees

• Trw Ltd

Inventors

• Wilkes Mark Anthony

Classifications

• G01D5/204

  by influencing the mutual induction between two or more coils (G01D5/22 takes precedence) · CPC title

• F16C33/40

  for multiple rows of balls · CPC title

• B62D1/185 Primary

  adjustable by axial displacement, e.g. telescopically (B62D1/183, B62D1/187, B62D1/19 take precedence) · CPC title

• F16C19/08

  with two or more rows of balls · CPC title

• F16C2326/24

  Steering systems, e.g. steering rods or columns · CPC title