Shift Fork Arch Geometry for Compact Vehicle Gearboxes
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Solution Overview
Problem
Existing vehicle transmission designs face challenges in optimizing the use of installation space and achieving a compact, resilient, and efficient shift fork configuration.
Innovation Solution
The design incorporates a fork arch with axial gradations and S-shaped contours that partially encompass the shift sleeve, allowing for axial offset positions and engagement elements to enhance rigidity and reduce friction, thereby optimizing space usage and transmission efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the fork arch is designed with axial gradation and S-shaped contours to partially encompass the shift sleeve, then the rigidity and load capacity of the shift fork are improved, but the device complexity increases
Solution Approach 1:
The fork arch incorporates S-shaped contours and axial gradation with curved surfaces instead of straight lines, creating a resilient structure that flexes during operation. The curved geometry allows the fork arch to encompass the shift sleeve while maintaining rigidity through strategic thickness variations.
Solution Approach 2:
The fork arch features non-uniform thickness distribution with axial gradation, where different sections have different thicknesses optimized for their specific functions. The first section has greater thickness for engagement with the gear wheel, while the second section tapers for engagement with the shift sleeve groove, providing localized strength where needed.
2Volume of moving object
If the shift fork is designed to be compact with axial offset positions, then the installation space is optimized, but the manufacturing precision requirements increase
Solution Approach 1:
The fork arch is designed to partially encompass the shift sleeve in a nested configuration, with the first section engaging the gear wheel and the second section engaging the shift sleeve groove. This nested arrangement allows compact packaging of multiple engagement points within the available radial and axial space.
Solution Approach 2:
The invention utilizes axial offset positioning to arrange engagement elements in different axial planes rather than requiring them to be coplanar. The first and second sections of the fork arch are offset axially relative to each other, allowing compact three-dimensional arrangement that reduces the overall volume of the shift fork.
3Reliability
If the first section of the fork arch engages in the groove of the shift sleeve while the second section overlaps with the gear wheel, then the engagement reliability is improved, but the friction and wear increase
Solution Approach 1:
The fork arch is designed as a flexible, dynamic element that can flex and deform during the shifting operation. The S-shaped contours and axial gradation allow the fork arch to adapt its shape during engagement, reducing impact forces and friction while maintaining reliable engagement with both the gear wheel and shift sleeve.
Data Source
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AI summary
The invention relates to a selector fork for actuating a selector sleeve (12a) in a vehicle transmission (14a), having a fork arc (16a; 16b; 16c; 16d; 16e; 16f) which, in an assembled state, at least partially surrounds the selector sleeve (12a), wherein the fork arc (16a; 16b; 16c; 16d; 16e; 16f) has an axial step in at least one region (18a; 18b; 18c; 18d; 18e; 18f).