Gearshift Return Mechanism Using Helical Cam and Spring
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Solution Overview
Problem
The existing gearshift assembly for vehicles requires the electric motor to reverse direction after returning the shift lever to the automatic shifting gate, complicating the operation and potentially causing damage if obstacles are encountered during the return process.
Innovation Solution
A return mechanism featuring a wheel with a helical cam surface that stores energy in a compression spring when an obstacle blocks the shift lever, allowing the shift lever to return to the automatic gate without motor reversal, simplifying the operation by using a single direction for the electric motor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the electric motor reverses direction to return the shift lever to the automatic shifting gate, then the shift lever can be returned reliably, but the operation becomes complex and the risk of damage increases when obstacles are encountered
Solution Approach 1:
The compression spring is pre-loaded during the forward movement of the shift lever, storing elastic potential energy before the return phase begins. This preliminary energy storage eliminates the need for motor reversal, as the spring automatically propels the shift lever back to the automatic gate when the forward movement stops
Solution Approach 2:
Obstacles that previously caused damage during motor reversal are now converted into beneficial pre-loading of the compression spring. When the shift lever encounters an obstacle during forward movement, the spring compresses further, storing additional energy that ensures reliable return movement even against the obstacle
2Adaptability or versatility
If the electric motor operates in reverse to reset the mechanism after return operation, then the system can be reused, but the operational complexity and potential damage risk increase
Solution Approach 1:
The compression spring performs the self-service function of automatically resetting the shift lever to the automatic shifting gate position after forward movement. The stored elastic energy in the spring is sufficient to overcome friction and return forces, eliminating the need for active motor intervention and enabling automatic reuse of the mechanism
Solution Approach 2:
The mechanism operates in periodic cycles: the electric motor drives forward movement, the spring stores energy during both normal and obstacle-blocked movement, then the spring releases energy to automatically return the shift lever. This periodic operation eliminates the need for motor reversal while maintaining full reusability
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 mechanism ensures reliable and simplified operation of the gearshift assembly by using the stored energy from the compression spring to complete the return movement to the automatic shifting gate, eliminating the need for motor reversal and reducing the risk of damage from obstacles.
Implementation Method 1
which comprises a spring acting between push member and driven member, which spring is loaded in case the return mechanism is activated to return the shift lever and an external counter-force is acting on the shift lever preventing the return movement in which case the force of the electric motor is converted to preload the spring
Implementation Method 2
A helical cam surface is provided on a front face of the wheel. The helical cam surface is coaxial with the axis of rotation of the wheel and increases in height over the front face in circumferential direction from a starting point with minimal height and returns back to the minimal height at the starting point after one turn
Data Source
AI summary
A gearshift assembly for a transmission includes a shift lever which is mounted for pivotal movement in a select direction between a shifting gate for automatic mode and a shifting gate for manual mode. The gearshift assembly also includes a return mechanism including a push member, an electric motor mechanically acting on the shift lever through the push member, a driven member connected to the push member, a spring acting between the push member and the driven member, and a blocking element which can be actuated to move out of a blocking position in which the blocking element blocks the movement of the shift lever from the shifting gate for automatic mode to the shifting gate for manual mode. The return mechanism also includes a wheel drivable for rotation by the electric motor.