Shifting Sleeve Tooth Profile for Transmission Gear Engagement
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Solution Overview
Problem
Vehicle transmissions face difficulties in gear engagement due to misalignment of shifting sleeves with transmission gears, particularly when switching between low and reverse positions, leading to increased time for gear changes and potential rattling noise.
Innovation Solution
A shifting sleeve design with teeth having distinct height and angle configurations to facilitate engagement with transmission gear openings, allowing for axial movement and improved alignment, even at different rotational speeds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the teeth of the shifting sleeve are shaped to fit tightly in the openings of the transmission gears to avoid premature wearing and reduce noise, then the durability and noise level are improved, but the alignment precision requirement increases making engagement difficult when rotating at significantly different speeds
Solution Approach 1:
The patent applies the dynamics principle by making the engagement process adaptive to varying rotational speeds. The shifting sleeve and transmission gear are designed to engage dynamically regardless of speed differences, eliminating the need for precise pre-alignment. The mechanism automatically adjusts during the engagement process to accommodate speed variations, resolving the contradiction between tight fitting for durability and alignment precision requirements.
2Ease of operation
If the gear selector is designed to require sequential engagement through neutral and high positions before reaching low position, then the shifting sequence control is improved, but the time required for position changes increases
Solution Approach 1:
The patent applies preliminary action by enabling the gear selector to be moved to the desired position in advance, even if the corresponding gear is not yet engaged. The system allows the operator to position the selector at the low position directly without forcing sequential movement through neutral and high positions. The engagement mechanism then completes the gear change automatically, reducing the time for position changes while maintaining controlled shifting sequences.
3Reliability
If the shifting sleeve and transmission gear are designed to require perfect alignment for engagement, then the engagement reliability is improved, but the ease of operation deteriorates when constant position changes are necessary
Solution Approach 1:
The patent applies self-service by designing the engagement mechanism to automatically align and engage the shifting sleeve with the transmission gear without requiring precise manual alignment by the operator. The mechanism includes features that enable automatic alignment during the shifting process, allowing the gear selector to engage reliably even during constant position changes. This eliminates the need for the operator to achieve perfect alignment manually, improving ease of operation while maintaining engagement reliability.
Data Source
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AI summary
A shifting sleeve (228) for selectively engaging a transmission gear in a vehicle transmission is provided. The transmission gear has at least one opening defined therein. The shifting sleeve comprises at least one tooth (230) for selectively engaging the at least one opening defined in the transmission gear (204). The at least one tooth extends from the shifting sleeve body (229) and has a first portion, a second portion and a third portion. The first portion (302) has a top surface disposed at a first height and the second portion (304) has a top surface disposed at a second height, the first height being greater than the second height. The third portion (306) is disposed between the first and second portions, and has a top surface disposed at an angle and extending between the top surfaces of the first and second portions.