Synchronizer Preceding Projecting Member Alignment
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Solution Overview
Problem
Conventional synchronizers experience two-stage connection issues due to misalignment of dog teeth and external splines, leading to driver discomfort through vibrations and unsmooth gear shifts.
Innovation Solution
A synchronizer design featuring a hub, sleeve, transmission gear, blocking ring, and synchronous spring, where a projecting member with an elastic portion is used to align the dog teeth and external splines, reducing impact and vibration by engaging before the internal splines, and utilizing a notch and chamfered portion to buffer collisions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the sleeve directly engages with the external splines without alignment assistance, then the structure is simpler, but two-stage connection occurs causing vibration and unsmooth gear shift
Solution Approach 1:
The preceding projecting member is positioned in advance within the blocking ring to engage with the external splines before the internal splines of the sleeve engage. This preliminary engagement action aligns the circumferential positions of the dog teeth and external splines, preventing two-stage connection and ensuring smooth gear shift without requiring complex asymmetric chamfer designs.
Solution Approach 2:
The preceding projecting member acts as an intermediary element between the blocking ring and the external splines. It mediates the engagement process by first contacting the external splines to establish proper alignment, then allowing the internal splines to engage smoothly, thereby eliminating the need for complex asymmetric sleeve designs.
2Ease of operation
If asymmetric chamfer is applied to the sleeve or external splines to prevent two-stage connection, then gear shift smoothness improves, but the sleeve still directly collides against external splines causing impact vibration
Solution Approach 1:
The preceding projecting member performs preliminary engagement with the external splines to align positions before the main engagement. This staged approach prevents direct collision between the sleeve and external splines, reducing impact vibration while maintaining the benefits of asymmetric engagement for smooth gear shift.
Solution Approach 2:
The elastic portion of the preceding projecting member provides beforehand cushioning by deforming elastically during the engagement process. This absorbs impact energy and reduces vibration transmitted to the sleeve and transmission gear, while still achieving proper alignment to prevent two-stage connection.
3Measurement precision
If a rigid projecting member is used to align dog teeth and external splines, then alignment precision improves, but impact collision increases causing vibration
Solution Approach 1:
The projecting member is designed with an elastic portion that changes its physical state from rigid to flexible during engagement. The elastic portion deforms under impact, absorbing collision energy while the overall structure maintains sufficient rigidity to achieve precise alignment of the dog teeth and external splines, thus resolving the contradiction between alignment precision and impact reduction.
Solution Approach 2:
The preceding projecting member combines rigid and elastic portions in a composite structure. The rigid portion ensures precise alignment geometry, while the elastic portion absorbs impact energy during engagement. This composite design achieves both high alignment precision and reduced impact collision simultaneously.
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
Prevents two-stage connection by aligning the circumferential-direction positions of dog teeth and external splines, reducing vibration and ensuring smooth gear shifts by absorbing impact through the elastic portion and synchronous spring mechanism.
Implementation Method 1
the preceding projecting member includes an elastic portion, and the preceding projecting member projects toward the external splines when the internal splines press the elastic portion
Implementation Method 2
a synchronous spring attached on the outer circumferential surface of the blocking ring, when the sleeve is moved in the axial direction from the neutral position to the operation position, the blocking ring being moved in the axial direction and frictionally engaged with the transmission gear
Implementation Method 3
the blocking ring being moved in the axial direction and frictionally engaged with the transmission gear, and the internal splines of the sleeve being engaged with the dog teeth of the blocking ring, thereby the rotation of the hub being synchronized with the rotation of the transmission gear
Data Source
AI summary
A synchronizer comprising: a hub including splines; a sleeve including internal splines; a transmission gear including external splines; a blocking ring including dog teeth, a notch and a preceding projecting member, wherein after the hub and the transmission gear are synchronized, the preceding projecting member is pressed by the internal splines, and engaged with the external splines before the internal splines.