Steering mechanism for autonomous vehicle

Patent metadata

Field	Value
Publication number	US-2021394818-A1
Application number	US-202016907460-A
Country	US
Kind code	A1
Filing date	Jun 22, 2020
Priority date	Jun 22, 2020
Publication date	Dec 23, 2021
Grant date	—

Abstract

A steering system for an autonomous vehicle or a steer-by-wire vehicle is simpler than a rack and pinion mechanism. The pinion is replaced by a roller and the toothed portion of the rack is replaced by a flat section. The bar, which replaces the rack is translated along its axis by an electric actuator such as a ball screw. The roller and a yoke prevent out of axis movement and prevent rotation about the axis.

First claim

What is claimed is:

1 . A vehicle steering system comprising:
a bar having an anti-rotation section, the anti-rotation section having a flat surface, the bar adapted for pivotable connection to a respective connecting rod at each end; an actuator configured to translate the bar along a bar axis in response to rotation of an electric motor; a roller in rolling contact with the flat surface to prevent rotation of the bar about the bar axis and limit deflection of the bar; and a yoke contacting the bar opposite the roller to prevent translation of the bar perpendicular to the bar axis.

2 . The vehicle steering system of claim 1 wherein the actuator comprises a ball nut engaging a threaded portion of the bar via rollers such that rotation of the ball nut results in translation of the bar.

3 . The vehicle steering system of claim 1 wherein the bar does not have a toothed section configured to mesh with a pinion gear.

4 . The vehicle steering system of claim 1 wherein the bar slides with respect to the yoke.

5 . An actuator for a vehicle steering system, the vehicle steering system comprising:
two knuckles, each supported to pivot about respective vertical axes and each defining respective wheel axes; two wheels, each supported for rotation about a respective one of the wheel axes; and two connecting rods, each pivotably connected to a respective knuckle; the actuator comprising: a bar pivotably connected to the two connecting rods and having an anti-rotation section, the anti-rotation section having a flat surface; a roller contacting the flat surface to prevent rotation of the bar about a bar axis; and a yoke contacting the bar opposite the roller to prevent translation of the bar perpendicular to the bar axis.

6 . The actuator of claim 5 further comprising a motor driveably connected to a ball screw drive, the ball screw drive engaging a threaded section of the bar to translate the bar along the bar axis in response to operation of the motor.

7 . The actuator of claim 6 further comprising a belt driveably connecting the motor to the ball screw drive.

8 . The actuator of claim 5 wherein the bar does not have a toothed section configured to mesh with a pinion gear.

9 . A vehicle steering system comprising:
a bar having a threaded section and an anti-rotation section, the anti-rotation section having a flat surface; a ball screw drive engaging the threaded section to translate the bar along a bar axis; a roller contacting the flat surface to prevent rotation of the bar about the bar axis; and a yoke contacting the bar opposite the roller to prevent translation of the bar perpendicular to the bar axis.

10 . The vehicle steering system of claim 9 further comprising a motor driveably connected to the ball screw drive.

11 . The vehicle steering system of claim 10 further comprising a belt driveably connecting the motor to the ball screw drive.

12 . The vehicle steering system of claim 10 further comprising:
a first knuckle configured to pivot about a first vertical axis, the first knuckle defining a first wheel axis; and
a first connecting rod pivotably connected at a first rod end to a first end of the bar and pivotably connected at a second rod end to the knuckle.

13 . The vehicle steering system of claim 12 further comprising a first wheel supported for rotation about the first wheel axis.

14 . The vehicle steering system of claim 12 further comprising:
a second knuckle configured to pivot about a second vertical axis, the second knuckle defining a second wheel axis; and
a second connecting rod pivotably connected at a third rod end to a second end of the bar and pivotably connected at a fourth rod end to the second knuckle.

15 . The vehicle steering system of claim 14 further comprising:
a first wheel supported for rotation about the first wheel axis; and
a second wheel supported for rotation about the second wheel axis.

16 . The vehicle steering system of claim 9 wherein the bar does not have a toothed section configured to mesh with a pinion gear.

17 . The vehicle steering system of claim 9 wherein the bar slides with respect to the yoke.

Assignees

• Schaeffler Technologies Ag

Inventors

• Zinnecker Michael
• De Paula Renato
• Adler Dieter

Classifications

• F16H55/283

  using pressure yokes · CPC title

• F16H2025/2081

  Parallel arrangement of drive motor to screw axis · CPC title

• F16H25/2204

  with balls · CPC title

• B62D5/0448 Primary

  Ball nuts · CPC title

• B62D5/001

  Mechanical components or aspects of steer-by-wire systems, not otherwise provided for in this maingroup · CPC title