Cable End Fitting Assembly With Progressive Self-Centering Damping
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Solution Overview
Problem
Existing cable end fitting assemblies face challenges in achieving a smooth self-centering function and preventing 'spongy' transmissions, particularly in gear shift systems, where large displacements are undesirable when active and require high return forces without driver assistance.
Innovation Solution
The cable end fitting assembly incorporates a damper ring with symmetrical longitudinal and lateral sectors, where the lateral sectors provide a large contact area for self-centering and increased return force, and the longitudinal sectors offer increasing resistance with displacement, along with projections in the cage ring to limit displacement and ensure smooth return to the original state.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the damper ring uses uniform elastomeric material distribution, then the structure is simple and easy to manufacture, but the return force is insufficient and cannot achieve smooth self-centering
Solution Approach 1:
The damper ring employs non-uniform elastomeric material distribution with varying cross-sectional areas across different sectors. The lateral sectors have larger cross-sectional areas to provide high return force for self-centering, while longitudinal sectors have smaller areas to allow initial displacement. This local differentiation enables each sector to perform its specific function optimally.
2Stability of the object's composition
If the damper ring allows large displacements, then vibrations can be absorbed when the gear shift system is inactive, but large displacements occur when active causing spongy transmission
Solution Approach 1:
The damper ring's stiffness is made dynamic through its sector-specific geometry. In the initial phase of displacement, longitudinal sectors allow large movement with low resistance for vibration absorption. As displacement increases and the socket contacts lateral sectors, the stiffness increases dramatically to prevent further large displacements during active operation, eliminating spongy transmission.
3Force
If the return force is high to achieve smooth self-centering, then the socket returns smoothly without driver assistance, but the initial phase requires high force causing resistance
Solution Approach 1:
The damper ring is divided into functionally distinct lateral and longitudinal sectors. Longitudinal sectors are designed with geometry that allows easy initial compression with minimal force, while lateral sectors are positioned to engage only after a certain displacement threshold is reached, at which point they provide the high return force needed for smooth self-centering.
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 smooth self-centering without driver assistance, providing a high return force for displacements up to 1.6 mm and sufficient stiffness during synchronization, preventing 'spongy' transmissions by optimizing the force versus displacement curve with a low slope initial phase and increasing stiffness.
Implementation Method 1
an elastic damper ring embracing the bushing
Implementation Method 2
the distribution of elastomeric material in the longitudinal sectors is not uniform and the amount of material compressed is increasing at larger displacements
Data Source
Figure 1
Figure 2~5
Figure 6
AI summary
The present invention is directed to a cable end fitting assembly for connecting a cable to a ball pin, comprising a terminal rod (2) adapted to be connected to an end portion of a cable and a ball bearing (4) adapted to receive a ball of a ball pin, the cable end fitting further comprising a socket (10) in which the ball bearing (4) is accommodated; an elastic damper ring (20) embracing the socket (10); and a cage ring (40) embracing and holding the damper ring (20), which cage ring (40) is connected to the terminal rod (2), wherein the damper ring (20) is composed of two symmetrical longitudinal sectors (22) symmetrically opposing each other in longitudinal direction of the terminal rod (2) and two symmetrical lateral sectors (24) symmetrically opposing each other in lateral direction perpendicular to the longitudinal direction, wherein the distribution of elastomeric material in the longitudinal sectors (22) is not uniform and the amount of material compressed is increasing at larger displacements in longitudinal direction,characterized in that the damper ring (20) is shaped such that in each of the two lateral sectors (24) the damper ring contacts the socket (10) in axial direction over the maximal axial extension of the damper ring, and such that, in a rest state when no force is exerted on the assembly, each longitudinal sector (22) is in contact with the socket (10) with a minimal axial extension surface and that the axial ex- tension of damper material is increasing with increasing radial distance from the center of the damper ring to the maximal axial extension of the damper ring such that from the beginning of any longitudinal displacement the more the socket (10) is displaced towards the respective longitudinal sector (22) the more damper material is compressed and the higher is the resistance force.