Disk Rotor Steering Assist Eliminates Gearing Friction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electric power assist steering systems for motor vehicles are prone to high friction, noise, and sensitivity to environmental factors due to their gearing systems, which can lead to inefficiencies and reliability issues.
Innovation Solution
A compact power assist apparatus with a disk rotor and stator arrangement, integrated electronic control unit, and rotation measuring device, eliminating the need for a gearing system, torque sensor, and separate sensors, while using field effect transistors for efficient electromagnetic compatibility and heat distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a gearing system is used in the power assist system, then force transmission is achieved, but friction and susceptibility to environmental influences increase
Solution Approach 1:
The patent replaces the mechanical gearing system with an electromagnetic direct-drive system. The induction motor is mounted directly on the steering column and transfers force without any intermediate gearing, thereby eliminating friction and sensitivity to environmental factors while maintaining force transmission capability.
2Force
If an induction motor is mounted on the steering column, then force transmission is achieved, but mass imbalance occurs
Solution Approach 1:
The patent employs asymmetric counterweights that are integrated into the steering column structure. These counterweights are specifically designed to offset the mass of the induction motor, achieving dynamic balance and eliminating vibrations caused by mass imbalance.
3Measurement precision
If a separate torque sensor is provided, then steering torque measurement is achieved, but device complexity increases
Solution Approach 1:
The patent integrates the torque sensor function directly into the induction motor structure. The motor's rotor and stator assembly serves dual purposes: generating steering assist force and measuring steering torque through the interaction between the rotor and stator, thereby eliminating the need for a separate torque sensor.
4Force
If a gearing system is used, then force amplification is achieved, but noise characteristics deteriorate
Solution Approach 1:
The patent replaces the mechanical gearing system with an electromagnetic direct-drive system. The induction motor mounted directly on the steering column transfers force without any intermediate gearing, thereby eliminating friction and sensitivity to environmental factors while maintaining force transmission capability.
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
The solution provides improved noise characteristics, reduced mass imbalance, increased operational reliability, and lower production costs, with enhanced steering assist torque and resistance to environmental influences.
Implementation Method 1
EP 0 125 918 A2 discloses an electrically-supported power assist system having an induction motor that is arranged on the steering column of a motor vehicle. The induction motor is a disk motor having windings that are supplied with current in an alternating manner depending upon the control of the driver.
Data Source
AI summary
A power assist device for supporting steering of a motor vehicle includes a steering column shaft and a housing. The shaft has a rotor and the housing has a stator. The stator is arranged in the radial direction with respect to the rotor. The rotor is a disk, and at least one magnet is arranged on the radially outer edge of said rotor.