Steering Column Belt Drive Pretensioning to Prevent Slippage
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Solution Overview
Problem
Existing motorized adjustment drives for steering columns in vehicles suffer from drive slippage and running noise due to varying belt tension caused by assembly and operational tolerances.
Innovation Solution
Incorporating a pretensioning device between the drive unit and spindle unit to maintain optimal belt tension, using a guide device to allow relative movement and a pretensioning force to ensure consistent belt tension, and employing a modular design with simple and cost-effective preload elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a belt drive is used to connect the drive wheel and gear wheel, then the adjustment drive achieves smooth operation and relatively low weight, but tolerances during assembly and operation cause belt tension to vary, leading to drive slippage and running noise
Solution Approach 1:
The drive unit is mounted movably relative to the spindle unit via a guide device, allowing the system to dynamically adjust to tension variations. The guide device enables the drive unit to move in a controlled manner to compensate for belt tension changes caused by tolerances, preventing slippage while maintaining smooth operation.
Solution Approach 2:
The pretensioning device actively adjusts the belt tension parameter to maintain optimal values. By applying a controlled pretensioning force through the guide device, the system compensates for tension variations due to assembly and operational tolerances, eliminating drive slippage and running noise while preserving the smooth operation characteristics of the belt drive.
2Reliability
If a pretensioning device is added to maintain optimal belt tension, then drive slippage and running noise are prevented, but the device complexity increases
Solution Approach 1:
The pretensioning function is merged with the existing guide device that connects the drive unit and spindle unit. Rather than adding a separate complex pretensioning mechanism, the guide device is designed to perform both guiding and pretensioning functions, thereby preventing drive slippage without significantly increasing overall device complexity.
Solution Approach 2:
The guide device is designed with multi-functionality, serving both as a structural connector and as a pretensioning mechanism. This universal design allows the same component to maintain belt tension and prevent slippage while avoiding the need for additional dedicated pretensioning devices, thus limiting the increase in device complexity.
3Reliability
If the drive unit is mounted movably relative to the spindle unit via a guide device, then belt tension is maintained and slippage is prevented, but the manufacturing precision requirements increase
Solution Approach 1:
The movably mounted drive unit creates a dynamic system that can adapt to manufacturing tolerances during assembly and operation. Rather than requiring extremely tight tolerances, the guide device allows controlled movement that compensates for tolerance variations, maintaining consistent belt tension without imposing stringent manufacturing precision requirements.
Solution Approach 2:
The system uses parameter changes in the form of controlled positional adjustments of the drive unit relative to the spindle unit. These adjustments allow the belt tension to be maintained within optimal ranges despite variations in assembly tolerances, thereby preventing slippage without requiring high manufacturing precision.
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
Enhances smooth operation and reduces wear by maintaining optimal belt tension, preventing slippage, and simplifying assembly, thereby improving the functional reliability and efficiency of the adjustment drive.
Implementation Method 1
a pretensioning device is arranged between the drive unit and the spindle unit, wherein the drive unit is mounted so as to be movable relative to the spindle unit in a guide device
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The present invention relates to an adjustment drive (5) for a motor-adjustable steering column (1) for a motor vehicle, comprising a spindle unit (6) with a threaded spindle (62) engaging a spindle nut (61) and having a spindle axis (S), and a drive unit (7) with a drive wheel (81) designed as a belt pulley, which is driven by an electric motor (71) about a drive axis (A), wherein a gear wheel (82) is connected to the spindle nut (61) or the threaded spindle (62) via a circulating belt (83). To enable improved operating characteristics, the invention proposes that a preload device be arranged between the drive unit (7) and the spindle unit (6).