Steering Column Cable Drive Eliminates Gear Noise
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Solution Overview
Problem
Steering column assemblies with gear mechanisms using threaded spindles suffer from noise issues due to play in the toothing system, which reduces comfort for vehicle occupants, especially at high adjusting speeds.
Innovation Solution
The use of a drive element wrapped around flexible guide elements, such as cords or cables, that transmit torque without play, allowing the steering shaft to be adjusted with low noise and high precision, providing a smooth and comfortable adjustment mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If threaded spindles are used in the gear mechanism, then the steering wheel can be adjusted rapidly and comfortably, but noise increases due to play in the toothing system
Solution Approach 1:
The patent replaces the traditional threaded spindle mechanism with a cable-driven system. The drive element is coupled to a flexible guide element (cable) that runs tensioned between two tensioning points, eliminating the meshed toothing system and its inherent play. This substitution maintains rapid adjusting capability while eliminating the noise source.
Solution Approach 2:
The patent employs a flexible guide element (cable) instead of rigid threaded spindle components. The cable is tensioned between two tensioning points and coupled to the drive element, allowing smooth transmission of motion without the mechanical play characteristic of threaded spindles, thereby reducing noise during steering wheel adjustment.
2Power
If threaded spindles are used in the gear mechanism, then torque can be transmitted to adjust the steering shaft, but play in the toothing system reduces precision
Solution Approach 1:
The patent replaces the threaded spindle's meshed toothing system with a cable-driven mechanism. The drive element couples to a tensioned flexible guide element that transmits motion directly to the steering shaft, eliminating backslash and improving adjustment precision while maintaining torque transmission capability.
3Speed
If high rotational speeds are used in threaded spindles, then rapid steering wheel adjustment is achieved, but noise and vibration increase
Solution Approach 1:
The patent substitutes the threaded spindle's high-speed rotational toothing with a cable-driven system. The drive element rotates at high speed but couples to a flexible guide element that translates this motion smoothly, eliminating the noise and vibration generated by rapid meshing and disengagement of toothing components.
Solution Approach 2:
The flexible guide element (cable) acts as a mediator between the high-speed rotating drive element and the steering shaft. This flexible connection smooths out high-speed fluctuations, eliminating the noise and vibration that would otherwise be generated by high-speed toothing engagement and disengagement.
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
This design ensures that the steering shaft can be adjusted with minimal noise, even at high speeds, resulting in a particularly smooth-running and comfortable steering column assembly.
Implementation Method 1
the drive element is wrapped around at least once without play by the first guide element and is coupled to it in a torque-transmitting manner such that the drive moves along the first guide element in or counter to (depending on the drive direction) the first tensioning direction when the drive shaft rotates about its longitudinal axis in or counter to a rotational direction
Data Source
AI summary
A steering column assembly for a motor vehicle has a bearing housing and a steering shaft which is mounted in the bearing housing, and an adjusting apparatus, by which the steering shaft can be adjusted. The adjusting apparatus has a drive with a drive element, a motor with a drive shaft, and a first flexible guide element which runs in a tensioned manner in a first tensioning direction between two first tensioning points. Here, furthermore, the drive element is wrapped around at least once without play by the first guide element and is coupled to it in a torque-transmitting manner such that the drive moves along the first guide element in or counter to the first tensioning direction when the drive shaft rotates in or counter to a rotational direction. Furthermore, a motor vehicle with a steering column assembly of this type is provided.