Steering Column Cam Mechanism Backlash Reduction
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Solution Overview
Problem
Existing steering apparatuses experience backlash and associated sounds during steering wheel position adjustments, which are difficult to fully mitigate without compromising lever operability.
Innovation Solution
A steering apparatus with a cam mechanism that includes a sleeve sliding over the cam, where grease is applied to the sliding surface between the sleeve and the cam, allowing for reduced backlash and sounds without affecting lever operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If a flexible tab is used to reduce backlash, then backlash and sounds are reduced, but the moving cam needs high load pressing which is difficult to achieve sufficiently and the flexible tab may interfere with cam movement affecting lever operability
Solution Approach 1:
The patent changes the physical state of the sliding surface by applying grease, transforming it from a dry friction interface to a lubricated interface. This parameter change (from dry to lubricated) reduces friction and backlash without requiring high loading forces or adding mechanical complexity that would interfere with lever operability
Solution Approach 2:
The grease acts as an intermediary substance between the sleeve and cam sliding surfaces. Instead of directly modifying the cam or sleeve structures (which could interfere with lever operation), the grease mediates the interaction by reducing friction and backlash in the sliding interface without affecting the mechanical transmission path of the lever
2Ease of operation
If a mechanical transmission mechanism such as a cam is used to lock and unlock the column, then position adjustment is achieved, but backlash and sounds are easily caused
Solution Approach 1:
The patent modifies the friction parameter of the cam mechanism by applying grease to the sliding surface between the sleeve and cam. This changes the interface from high-friction dry contact to low-friction lubricated contact, thereby reducing backlash and sounds while preserving the position adjustment function
Solution Approach 2:
The patent converts the inherent friction in the cam mechanism, which normally causes backlash and sounds, into a beneficial lubricated interface. By applying grease, the friction is controlled and reduced to beneficial levels that eliminate harmful backlash and sounds while maintaining the necessary friction for reliable locking and unlocking
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 effectively reduces backlash and associated sounds during steering wheel position adjustments while maintaining the operability of the lever, providing a simple and efficient solution.
Implementation Method 1
grease is applied to a sliding surface between the sleeve and the cam
Data Source
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AI summary
A steering apparatus is provided which can sufficiently reduce backlash that may occur upon position adjustment of a steering wheel and the sounds from such backlash in a simple manner without affecting the operability of a turning lever. A steering apparatus 1 is able to make tilt and telescopic position adjustment of a steering wheel H by moving a column 20 that holds a shaft of the steering wheel H relative to a vehicle body. The steering apparatus 1 has: a turning lever 123 for locking and unlocking the column 20 relative to the vehicle body; cams 120 and 121 that convert a turning movement of the turning lever 123 into a movement in the axial direction of the turning movement, thereby locking and unlocking the column 20; and a sleeve 122 that holds the cams 120 and 121 and slides with respect to the cams 120 and 121 when the turning lever 123 turns. Grease A is applied to a sliding surface between the sleeve 122 and the cams 120 and 121.