Transmission Shift Fork Oil Catch and Fin Design
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Solution Overview
Problem
Conventional transmission shift forks face challenges in supplying sufficient lubricating oil to the nail portion due to the high-speed rotation of the coupling sleeve, leading to wear and increased costs associated with machining through holes for improved oil supply.
Innovation Solution
A transmission shift fork design featuring a coupling sleeve engagement part with an oil catch and a fin that projects from an oil receiving recess, allowing for efficient lubrication and cooling, formed through die casting without additional machining, enhancing durability and service life while maintaining cost-effectiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a through hole is formed to allow oil to pass from the oil catch to the nail portion, then the amount of oil supplied to the nail portion is improved, but the manufacturing cost increases due to additional machining
Solution Approach 1:
The patent applies preliminary action by forming the oil supply passage and oil catch as integral features during the die-casting process itself, rather than adding them through subsequent machining operations. This allows oil to be pre-positioned in the nail portion area before the component is assembled, ensuring reliable lubrication while avoiding additional manufacturing costs associated with drilling or machining operations.
Solution Approach 2:
The die-casting process itself serves the dual function of creating both the structural components and the oil supply features. The mold design incorporates oil catches and passages that are automatically formed during casting, making the manufacturing process self-sufficient for creating both mechanical and lubrication features without requiring separate machining steps.
2Productivity
If the coupling sleeve rotates at high speed, then the transmission shifting function is improved, but the nail portion incurs wear due to insufficient oil supply
Solution Approach 1:
The patent introduces an intermediary oil supply system consisting of oil catches positioned to receive lubricating oil and passages that transport it to the nail portion. This intermediary lubrication system bridges the gap between the bulk oil reservoir and the high-speed rotating coupling sleeve interface, ensuring continuous oil supply even during rapid transmission shifting operations.
Solution Approach 2:
The oil catch and passage structure pre-positions lubricating oil near the nail portion before the coupling sleeve engages in high-speed rotation. This preliminary oil positioning ensures that lubrication is already in place before wear-prone contact occurs, allowing the transmission to handle rapid shifting without compromising the service life of the nail portion.
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 design ensures reliable lubrication and reduced friction between the coupling sleeve engagement part and the engaging groove, improving the service life of the shift fork without increasing manufacturing costs, and provides effective cooling through the integration of fins.
Implementation Method 1
at least one fin projects from inside an oil receiving recess defined by the oil catch
Implementation Method 2
at least one fin projects from inside an oil receiving recess defined by the oil catch
Implementation Method 3
the outwardly facing surface includes an oil catch disposed in a position with respect to the coupling sleeve engagement part such that the oil catch captures lubricating oil
Implementation Method 4
the outwardly facing surface includes an oil catch disposed in a position with respect to the coupling sleeve engagement part such that the oil catch captures lubricating oil
Implementation Method 5
the coupling sleeve facing surface includes at least one coupling sleeve engagement part configured and arranged to engage with an engaging groove formed on an external circumferential surface of the coupling sleeve
Data Source
AI summary
A transmission shift fork engages with a coupling sleeve of a synchronizer and shifting the coupling sleeve. The transmission shift fork includes a first part, second part, and at least one fin. The first part is arranged to movably mount the transmission shift fork in a shift fork movement direction. The second part includes a coupling sleeve facing surface, an outwardly facing surface, and a pair of shift-direction facing surfaces. The coupling sleeve facing surface includes at least one coupling sleeve engagement part arranged to engage with an engaging groove formed on an external circumferential surface of the coupling sleeve. The outwardly facing surface includes an oil catch disposed in a position with respect to the coupling sleeve engagement part such that the oil catch captures lubricating oil and supplies to the coupling sleeve engagement part. The fin projects from inside an oil receiving recess defined by the oil catch.