Electric power steering gear with an anti-rotate feature

Patent metadata

Field	Value
Publication number	US-12594983-B2
Application number	US-202318470460-A
Country	US
Kind code	B2
Filing date	Sep 20, 2023
Priority date	Sep 20, 2023
Publication date	Apr 7, 2026
Grant date	Apr 7, 2026

Abstract

An electric powered steering assembly includes a housing with a cylindrical portion, an interior wall of the cylindrical portion defining a first and second grooves extending in an axial direction, the first and second grooves having inwardly tapered walls. A ball screw is disposed in the housing, extending in the axial direction, and defining a through hole extending in a radial direction having a first and second ends. A ball nut is disposed in the housing surrounding the ball screw and configured to rotate relative to the housing. A first anti-rotational pin is disposed in the first end of the through hole, a second anti-rotational pin is situated in the second end of the through hole, and a spring is disposed between the anti-rotational pins. The spring is configured to bias the first and second anti-rotational pins in a radially outward direction towards the first and the second groves respectively.

First claim

What is claimed is:

1 . An electric powered steering assembly for a commercial vehicle, comprising:
a housing including a cylindrical portion extending in an axial direction, an interior wall of the cylindrical portion defining a first groove and a second groove extending in the axial direction, the first and second grooves having inwardly tapered walls; a ball screw disposed in the housing, extending in the axial direction, and defining a through hole extending in a radial direction having a first and second ends; a ball nut disposed in the housing surrounding the ball screw and configured to rotate relative to the housing; a first anti-rotational pin having at least one tapered end disposed in the first end of the through hole; a second anti-rotational pin having at least one tapered end disposed in the second end of the through hole; and a spring disposed between the first anti-rotational pin and the second anti-rotational pin and configured to bias the first anti-rotational pin and the second anti-rotational pin in a radially outward direction towards the first and the second groves respectively so that the at least one tapered end of the first anti-rotational pin and the at least one tapered end of the second anti-rotational pin engage the first and second grooves respectively and thereby restrict rotation of the ball screw relative to the housing.

2 . The electric powered steering gear of claim 1 , wherein the first and second grooves inwardly taper at a first angle.

3 . The electric powered steering gear of claim 2 , wherein the at least one tapered end of the first anti-rotational pin and the at least one tapered end of the second anti-rotational pin taper at the first angle to match the taper of the first and second grooves respectively.

4 . The electric powered steering gear of claim 1 , wherein the ball nut is configured to rotate over the ball screw and engage threads of the ball screw.

5 . The electric powered steering gear of claim 4 , wherein the rotation of the ball nut over the ball screw results in an axial translation of the ball screw in a right or left direction based on a rotational direction of the ball nut.

6 . The electric powered steering gear of claim 1 , wherein engaging the first and second grooves with the first and second anti-rotational pins restricts the rotation of the ball screw relative to the ball nut.

7 . A method of providing a lash-free electric powered steering gear for a commercial vehicle, the method comprising:
providing a housing including a cylindrical portion extending in an axial direction, an interior wall of the cylindrical portion defining a first groove and a second groove extending in the axial direction, the first and second grooves having inwardly tapered walls; providing a ball screw disposed in the housing, extending in the axial direction, and defining a through hole extending in a radial direction having a first and second ends; providing a ball nut disposed in the housing surrounding the ball screw and configured to rotate relative to the ball screw; providing a first anti-rotational pin having at least one tapered end disposed in the first end of the through hole; providing a second anti-rotational pin having at least one tapered end disposed in the second end of the through hole; and exerting a radially outward force on the first anti-rotational pin and the second anti-rotational pin using a spring disposed between the first anti-rotational pin and the second anti-rotational pin so as to bias the first anti-rotational pin and the second anti-rotational pin in a radially outward direction towards the first and the second groves respectively so that the at least one tapered end of the first anti-rotational pin and the at least one end of the second anti-rotational pin engage the first and second grooves respectively and thereby restrict rotation of the ball screw relative to the housing.

8 . The method of claim 7 , wherein the first and second grooves inwardly taper at a first angle.

9 . The method of claim 8 , wherein the at least one tapered end of the first anti-rotational pin and the at least one tapered end of the second anti-rotational pin taper at the first angle to match the taper of the first and second grooves respectively.

10 . The method of claim 7 , wherein the ball nut is configured to rotate over the ball screw and engage threads of the ball screw.

11 . The method of claim 10 , wherein the rotation of the ball nut over the ball screw and engaging the threads of the ball screw results in an axial translation of the ball screw in a right or left direction based on a rotational direction of the ball nut.

12 . The method of claim 7 , wherein engaging the first and second grooves with the first and second anti-rotational pins restricts the rotation of the ball screw relative to the ball nut.

Assignees

• Zf Cv Systems Global Gmbh

Inventors

• Boyle Kevin
• Crum Caleb
• Schoon Benjamin
• Volmering Zach Robert

Classifications

• F16H25/2204

  with balls · CPC title

• F16H2025/204

  Axial sliding means, i.e. for rotary support and axial guiding of nut or screw shaft · CPC title

• F16H25/20

  Screw mechanisms (with automatic reversal F16H25/12) · CPC title

• B62D5/0448 Primary

  Ball nuts · CPC title

• B62D5/0445 Primary

  Screw drives · CPC title