Worm Gear Single-Wheel Steering for Large Pivot Angles
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Solution Overview
Problem
Existing single-wheel steering systems for motor vehicles are complex, space-intensive, and limited to small steering angles due to their design, which restricts the range of motion and efficiency of the steered wheels.
Innovation Solution
A wheel suspension device with a worm gear and double bevel gear system, where the bevel gear and worm are housed in a non-pivotable housing resiliently connected to the steering knuckle, allowing for larger steering angles and reduced weight and installation space, with a steering motor and cardan shafts for precise control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conventional drive shaft with constant velocity joint is used to power the steered wheel, then the drive connection is established, but the maximum steering angle is limited to approximately 40°
Solution Approach 1:
The patent replaces the conventional constant velocity joint mechanical system with a worm gear mechanism. The worm gear allows the drive shaft to remain stationary while the wheel steers through large angles, eliminating the steering angle limitation of constant velocity joints. The worm gear's self-locking feature also provides inherent mechanical advantage for maintaining position at extreme angles.
Solution Approach 2:
The patent introduces a worm gear as an intermediary between the drive shaft and the wheel hub. This intermediary mechanism decouples the rotational movement of the drive shaft from the steering movement of the wheel, allowing independent optimization of each component and enabling steering angles beyond 40° without compromising drive connection.
2Ease of operation
If linear drives with tie rods are used for single-wheel steering, then the steering control is achieved, but the steering angle is limited to approximately 40° and the design becomes complex
Solution Approach 1:
The patent replaces the linear drive with tie rod system with a rotary worm gear mechanism. The worm gear directly converts rotational motion from the motor into wheel steering, eliminating the need for linear actuators, tie rods, and complex linkage mechanisms. This substitution simplifies the overall steering mechanism while enabling larger steering angles.
Solution Approach 2:
The patent extracts and eliminates the tie rod and linear drive components from the steering system. By using the worm gear mechanism mounted directly on the wheel hub, the system removes the intermediate tie rod linkage, reducing mechanical complexity and enabling greater steering angle range.
3Ease of operation
If existing single-wheel steering systems are implemented, then the steering function is provided, but the installation space requirement is large and the design is complex
Solution Approach 1:
The patent nests the worm gear mechanism within the wheel hub assembly, integrating the steering actuator directly into the existing wheel structure. The worm gear is mounted on the wheel hub's rotation axis, utilizing the existing rotational space, thereby minimizing additional installation space requirements while providing full steering functionality.
Solution Approach 2:
The patent makes the wheel hub multi-functional by integrating both the steering actuator (worm gear) and the drive connection into a single assembly. The wheel hub serves as both the mounting structure for the steering mechanism and the connection point for the drive shaft, eliminating the need for separate steering linkages and reducing overall space requirements.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables steering angles of up to -70° to +90°, significantly expanding the range of motion while minimizing unsprung mass and space requirements, and maintaining drive torque transmission even at extreme angles.
Implementation Method 1
a steering drive shaft designed as a cardan shaft between the worm gear and the steering motor
Implementation Method 2
resiliently suspended with the axle stub in the direction of the pivot axis
Data Source
Figure 1~3
Figure 4~6
AI summary
The invention relates to a wheel suspension device having single-wheel steering for a motor vehicle with driving of the steered wheels, with a steering knuckle (12) spring-suspended on the vehicle chassis for rotatably mounting a vehicle wheel (2), wherein the steering knuckle (12) can be pivoted about a pivot axis (15) by means of the single-wheel steering, wherein the wheel suspension device is improved in order to achieve a large pivot range with a compact and simple construction, in that the single-wheel steering has a worm drive (18, 19) with a worm gear (18) which is rotationally fixed to the steering knuckle (12) and arranged coaxially to the pivot axis (15), and which is engaged with a worm (19), by means of which the worm gear (18) can be rotated about the pivot axis (15) and which can be driven via a steering drive shaft (20) configured as a drive shaft by a steering motor (9) arranged on the vehicle chassis.