Chassis actuator and method for operating a transmission assembly of a chassis actuator

Patent metadata

Field	Value
Publication number	US-2022252141-A1
Application number	US-202017594954-A
Country	US
Kind code	A1
Filing date	Apr 22, 2020
Priority date	May 13, 2019
Publication date	Aug 11, 2022
Grant date	—

Abstract

A chassis actuator (1), in particular for a rear axle steering system, includes a rotational-linear transmission (5) which is provided for coupling, on the output side, to a chassis element, wherein a rotatable, input-side element (9) of the transmission (5) is mounted in a housing (13) by means of at least one axial bearing (16, 17). The transmission (5) is self-lockingly set by means of an adjustable preloading device (21), which loads the axial bearing (16, 17) with an axial force.

First claim

1 . A chassis actuator, with a rotational-linear transmission which is adapted for coupling, on the output side, to at least one chassis element, wherein a rotatable, input-side element of the rotational-linear transmission is mounted in a housing by means of at least one axial bearing, wherein an adjustable preloading device loads the axial bearing with an axial force, wherein the transmission is self-lockingly set by the axial force.

2 . The chassis actuator according to claim 1 , wherein the pre-loading device comprises a preloading nut screwed into an internal thread of the housing as a fine readjustment element.

3 . The chassis actuator according to claim 2 , wherein the pre-loading nut is in contact with a bearing element of the axial bearing.

4 . The chassis actuator according to claim 3 , wherein the axial bearing is a roller bearing.

5 . The chassis actuator according to claim 4 , wherein the axial bearing comprises, in addition to rolling elements which perform the axial bearing function, rolling elements for radial bearings, wherein all of the rolling elements are in contact a same bearing element.

6 . The chassis actuator according to claim 4 , wherein the axial bearing comprises rolling elements which perform both the axial bearing function and a radial bearing function.

7 . The chassis actuator according to claim 1 , wherein the rotational-linear transmission is a planetary roller gear system.

8 . The chassis actuator according to claim 7 , wherein a continuously variable transmission is connected upstream of the planetary roller gear systems.

9 . A method for operating a two-stage transmission assembly of a chassis actuator, the chassis actuator comprising a continuously variable transmission and a rotational-linear transmission connected downstream of the continuously variable transmission, the method comprising adjusting a pre-load of an input-side element of the rotational-linear transmission using a fine re-adjustment element acting on an axial bearing of the rotational-linear transmission in such a way that the overall efficiency of the transmission assembly is kept below 50%.

10 . The method according to claim 9 , wherein the efficiency of the entire transmission assembly is set to a value of at least 35% and a maximum of 45% by the axial force acting in the rotational-linear transmission.

11 . A method of assembling a chassis actuator, the method comprising:
providing a rotational-linear transmission having an input element wherein the input element is supported with respect to a housing by axial bearings; providing a fine-adjustment element between the axial bearings and the housing configured to vary an axial pre-load on the input element; and adjusting the pre-load using the fine-adjustment element to make the chassis actuator self-locking.

12 . The method of claim 11 wherein the fine-adjustment mechanism is a preloading nut screwed into an internal thread of the housing.

13 . The method of claim 11 further comprising:
providing a rotational-rotational transmission upstream of the rotational-linear transmission; and wherein
a combined efficiency of the rotational-rotational transmission and the rotational-linear transmission is less than 50% after adjusting the pre-load.

14 . The method of claim 13 wherein the combined efficiency is between 35% and 45% after adjusting the pre-load.

15 . The method of claim 13 wherein the rotational-rotational transmission is a continuously variable transmission.

Assignees

• Schaeffler Technologies Ag

Inventors

• Wuebbolt-Gorbatenko Benjamin
• Hausmann Alexander
• Faber Daniel
• Pöhnlein Alena

Classifications

• B62D5/0445 Primary

  Screw drives · CPC title

• B62D7/1581 Primary

  characterised by comprising an electrical interconnecting system between the steering control means of the different axles · CPC title

• F16H2025/2081

  Parallel arrangement of drive motor to screw axis · CPC title

• B62D7/148

  provided with safety devices · CPC title

• F16H25/2252 Primary

  Planetary rollers between nut and screw · CPC title