Gearbox Control Lever Return Mechanism Friction Reduction
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Solution Overview
Problem
Current motor vehicle gearbox control devices experience noise and precision loss due to friction and wear of sleeves covering the return spring branches, caused by the movement of the return support element along spherical curves centered on the ball joint.
Innovation Solution
The return support element is relocated to move in a plane at a constant distance from the return axis, minimizing slipping contact and wear on the sleeves, with branches of the return spring resting on the support element for reduced friction and effort in operating the control lever.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the return support element is carried by the control finger and moves along spherical curves, then the control lever can be operated, but sliding friction occurs between the return support element and the return spring branches causing noise and wear
Solution Approach 1:
The patent introduces a return member as an intermediary element between the control finger and the return spring. The return support element is carried by this return member instead of directly by the control finger, allowing the return support element to move in a plane at constant distance from the return axis while the control finger moves along spherical curves. This intermediary structure eliminates direct sliding friction between the return support element and return spring branches.
Solution Approach 2:
The patent changes the movement dimension of the return support element from three-dimensional spherical curves to two-dimensional planar motion. By constraining the return support element to move in a plane at constant distance from the return axis, the invention transforms the friction problem from sliding contact to rolling or minimal contact, thereby reducing wear and noise.
2Object-affected harmful factors
If sleeves are added to cover the return spring branches to prevent noise, then friction noise is reduced, but sleeve wear occurs causing long-term precision loss
Solution Approach 1:
The patent extracts and removes the sleeves that were previously necessary to cover the return spring branches. By fundamentally changing the movement pattern of the return support element to move in a plane at constant distance from the return axis, the invention eliminates the sliding friction that necessitated the use of sleeves, thereby removing the source of both noise and subsequent wear.
3Measurement precision
If the return support element moves along spherical curves centered on the ball joint, then the control lever can be positioned, but sliding friction causes wear and precision loss over time
Solution Approach 1:
The return member serves as an intermediary that decouples the motion paths of the control finger and the return support element. This allows the return support element to follow a planar trajectory at constant distance from the return axis, eliminating sliding friction and preserving positioning precision throughout the service life of the device.
Solution Approach 2:
By transitioning the return support element from three-dimensional spherical motion to two-dimensional planar motion, the invention fundamentally reduces friction and wear, thereby extending the duration over which precise positioning can be maintained.
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 maintains gearbox precision and silence through reduced sleeve wear and minimized friction, enhancing the long-term performance of gearbox control devices by preventing slipping contact and wear on the sleeves.
Implementation Method 1
a return spring (12) carried by the housing (1) and having branches (13) extending on either side of a return support element (15) mounted to press elastically on the branches (13) of the return spring during movements of the control lever (2)
Data Source
Figure 1~2
AI summary
The control device of a gearbox of a motor vehicle comprises: a housing (1) in which is mounted a control lever (2) associated with a ball joint (3); a control finger (4) fixed to the ball joint and extending in a radial direction from the ball joint; a return member (5) mounted on the housing to pivot about a return axis (6) extending perpendicularly to the control lever for a rest position of the latter, and associated in an articulated manner with the control finger on one side, and with a control member (8) of the gearbox on the other; and a return spring (12) carried by the housing and having arms (13) extending on either side of a return support element (15) carried by the return member (5).