Damping bearing with axial preload

Patent metadata

Field	Value
Publication number	US-11209066-B2
Application number	US-201716335465-A
Country	US
Kind code	B2
Filing date	Oct 9, 2017
Priority date	Oct 11, 2016
Publication date	Dec 28, 2021
Grant date	Dec 28, 2021

Abstract

A method of manufacturing a damping device, notably for a steering tie rod, the said device comprising a rod which extends along a main axis and which is intended to be connected to a first mechanical component, a securing portion which surrounds the said rod and which is intended to be connected to a second mechanical component, and a sleeve made of elastomeric material which is arranged between the rod and the fixing bushing so as, through elastic deformation thereof, to allow at least axial movement of the fixing bushing with respect to the rod, in which method the fixing bushing is offset axially with respect to the rod to force the elastic deformation of the sleeve and the introduction of a corresponding preload, then the sleeve is locked so as to keep it, when the device is at rest, in a state of permanent axial elastic deformation and preload.

First claim

The invention claimed is:

1. A method for manufacturing a damping device comprising a shaft, which extends along a main axis and which is intended to be connected to a first mechanical part, a fixing bushing which surrounds said shaft and which is intended to be connected to a second mechanical part, and a sleeve made of elastomeric material which is arranged between the shaft and the fixing bushing so as to allow, by its elastic deformation, at least one axial displacement of the fixing bushing relative to the shaft, said method including:
a preparation step (a), during which the shaft is inserted into the fixing bushing so that the fixing bushing at least partially surrounds the shaft and axially occupies a first position relative to said shaft, and a filling space is provided radially between the shaft and the fixing bushing,
an over-molding step (b), during which the filling space is at least partially filled so as to create the elastomeric sleeve which links the shaft to the fixing bushing,
a step (c) of creating a preload, during which the axial displacement of the fixing bushing relative to the shaft is forced in a direction called «load direction», so as to axially offset the fixing bushing from its first position to a second position axially distinct from the first position, against an elastic deformation of the sleeve, in order to create an axial preload of said sleeve, and therefore an axial preload of the shaft relative to the fixing bushing,
a locking step (d), during which the elastomeric sleeve is locked against the shaft or against the fixing bushing, so as to maintain on the one hand a relative mobility of the shaft relative to the fixing bushing, via the sleeve, and on the other hand at least partly maintain the axial preload of the sleeve and therefore at least partly maintain the axial preload of the shaft relative to the fixing bushing.

2. The method according to claim 1 wherein the sleeve has, along the main axis on the one hand a downstream segment, which axially abuts, in the load direction, against a stop shoulder arranged on the shaft, and on the other hand an upstream segment, which is forcibly displaced relative to the downstream segment, in the load direction, when offsetting the fixing bushing from its first position to its second position during step (c) of creating the preload, then which is placed, during the locking step (d), against a locking flange provided on the shaft, so that it cannot be displaced in a direction opposite to the load direction.

3. The method according to claim 2 wherein the shaft has a plurality of axially staggered stop grooves in order to provide several annular stop shoulders which cooperate with the downstream segment of the sleeve.

4. The method according to claim 3 wherein the stop grooves of the shaft have rounded shapes so as to axially define, at the surface of the shaft, a corrugated shaft hooking profile.

5. The method according to claim 3 wherein the fixing bushing has an inner wall which has, at a radial distance from the shaft, a sinuous hooking profile which is substantially or even exactly mating the shaft hooking profile formed by the stop grooves which serve to retain the downstream segment of the sleeve.

6. The method according to claim 1 wherein, during the locking step (d), an upstream segment of the elastomeric sleeve is radially pushed by a centripetal plastic deformation of the fixing bushing, so as to radially penetrate said upstream segment of the sleeve into a locking groove which is hollowed in the shaft and which has a wall forming a locking flange intended to prevent said upstream segment of the sleeve from performing a return movement opposite to the movement which corresponds to the load direction.

7. The method according to claim 1 wherein it comprises an assembly step (e), during which the fixing bushing is fixed, into a case belonging to the second mechanical part.

8. The method according to claim 1 wherein the shaft belongs to a tie rod.

9. A damping device comprising
a shaft which extends along a main axis and which is intended to be connected to a first mechanical part,
a fixing bushing which surrounds said shaft and which is intended to be connected to a second mechanical part, and
a sleeve made of elastomeric material which is arranged between the shaft and the fixing bushing so as to allow, by its elastic deformation, at least one axial relative displacement of the fixing bushing relative to the shaft, wherein:
the sleeve is maintained, when the device is at rest, in a state of permanent axial elastic deformation which creates and maintains an axial preload of said sleeve and therefore an axial preload of the shaft relative to the fixing bushing;
the fixing bushing at rest is in a second position that is axially offset from a first position of the fixing bushing after locking of the sleeve; and
the fixing bushing can be elastically displaced relative to the shaft on either side of said second position of said fixing bushing by axial sliding via the sleeve which is elastically deformed to accompany said sliding, and the shaft can be elastically displaced relative to the fixing bushing, in axial translation on either side of said second position of said fixing bushing, and in the vicinity of said second position against the elastic return exerted by the preloaded sleeve which can be deformed in order to accommodate such displacement.

10. A power steering system comprising a tie rod whose shaft is equipped with the damping device according to claim 9 .

Assignees

• Jtekt Europe Sas

Inventors

• Durand Philippe

Classifications

• B62D7/228

  acting between the steering gear and the road wheels, e.g. on tie-rod · CPC title

• F16F1/3842 Primary

  Method of assembly, production or treatment; Mounting thereof (supports for pipes, cables or protective tubing F16L3/00) · CPC title

• F16F2224/025

  Elastomers · CPC title

• B29C45/14491

  Injecting material between coaxial articles, e.g. between a core and an outside sleeve for making a roll · CPC title

• B29K2995/0046

  Elastic · CPC title