Shift Sleeve Synchronization for Low-Impact Gear Engagement
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Solution Overview
Problem
Current gear shifting methods in hybrid vehicles, such as dual clutch transmissions (DCT) and automated manual transmissions (AMT), experience noise and wear due to mechanical interference and impact between shift sleeve teeth and gear wheel teeth, leading to delayed shifts and reduced transmission lifespan.
Innovation Solution
A control method and system that controls the synchronization and gear engagement of shift sleeves in stepped gear transmissions by determining phase plane trajectories to minimize relative displacement between sleeve and gear teeth, applying synchronization torque to keep the displacement within target boundaries, and using closed-loop controllers to adjust for accurate alignment, thereby reducing mechanical interference and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional mechanical synchronization systems are used for gear shifting, then the transmission can achieve gear engagement, but mechanical interference and impact between shift sleeve teeth and gear wheel teeth cause noise, wear, and delayed shifts
Solution Approach 1:
The patent applies parameter changes by precisely controlling the relative displacement and rotational speed difference between the shift sleeve and gear wheel during synchronization. By adjusting these parameters to follow optimal phase plane trajectories, the system achieves engagement while minimizing mechanical interference and impact, thereby reducing noise and wear without sacrificing reliability
Solution Approach 2:
The patent implements feedback control by continuously monitoring the relative displacement and rotational speed difference, then adjusting the synchronization torque accordingly. The closed-loop controller ensures the system follows the desired phase plane trajectory by comparing actual values with target values and making real-time corrections, which reduces harmful mechanical impacts while maintaining reliable engagement
2Productivity
If conventional gear shifting control is used, then gear engagement can be achieved, but the gear shift time is extended due to mechanical interference and impact
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing optimal phase plane trajectories for synchronization before gear shifting occurs. These trajectories define the ideal relationship between relative displacement and rotational speed difference, allowing the system to execute fast, smooth engagement without delays caused by mechanical interference during the actual shifting process
3Reliability
If mechanical synchronization systems are used, then gear engagement is achieved, but noise is generated due to impact between sleeve teeth and gear teeth
Solution Approach 1:
The patent reduces gear shift noise by changing the operational parameters of the synchronization process. By controlling the relative displacement and rotational speed difference to follow optimal trajectories, the system minimizes impact forces between teeth, thereby reducing noise generation while maintaining reliable engagement and extending transmission lifespan
Data Source
AI summary
A method for motion control of a shift sleeve in a stepped gear transmission during a synchronization and gear engagement sequence for avoiding gear teeth interference, wherein the stepped gear transmission includes an axially displaceable shift sleeve arranged on and rotationally secured to a shaft, and a constant mesh gear wheel arranged on and rotatable relative to said shaft.