Gearbox Synchronizer Ventilation Contour Reduces Shifting Effort
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Solution Overview
Problem
Existing manual transmission synchronizers require increased effort to engage gears due to frictional forces, especially when stationary, as the synchronizer ring is axially loaded by the pressure piece, leading to inefficient gear engagement.
Innovation Solution
A synchronization system with a sliding sleeve and an elastic adjusting element, featuring a ventilation contour and locking recess, divides the pressure piece's action into two sections: pre-synchronization and release, reducing friction by actively releasing the synchronizer ring from axial loading, allowing smooth gear engagement with smaller cone angles and increased synchronizing capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the pressure piece is used to press the synchronizer ring during shifting, then the synchronizer ring can generate frictional torque for synchronization, but the friction between the pressure piece and synchronizer body prevents the pressure piece from retracting, requiring increased force for gear engagement
Solution Approach 1:
The harmful frictional force between the pressure piece and synchronizer body is extracted and eliminated by introducing the elastic element. The elastic element takes over the function of pressing the synchronizer ring, while the pressure piece is extracted from this function and only serves to actuate the elastic element, thereby eliminating the harmful friction and allowing easy retraction.
Solution Approach 2:
The elastic element is introduced as an intermediary between the pressure piece and the synchronizer ring. This intermediary absorbs the pressing function, allowing the pressure piece to move freely without friction against the synchronizer body, while still maintaining the necessary frictional torque on the synchronizer ring through the elastic element's action.
2Productivity
If the sliding sleeve is moved into the engaged position, then the gear can be coupled to the synchronizer body, but the synchronizer ring remains axially loaded by the pressure piece generating frictional torque that must be overcome
Solution Approach 1:
The elastic element is pre-loaded during the synchronization phase to store energy. When the sliding sleeve moves into the engaged position, this pre-stored energy automatically releases, propelling the pressure piece away from the synchronizer ring without requiring additional engagement force from the operator.
Solution Approach 2:
The system transitions from a continuous pressing action to a periodic action where the elastic element is compressed during synchronization and then releases during engagement. This periodic compression and release eliminates continuous frictional torque during the engagement phase, reducing the force required.
3Reliability
If a larger cone angle is used on the synchronizer ring, then the frictional torque increases improving synchronization, but the axial loading on the synchronizer ring increases requiring more force for engagement
Solution Approach 1:
The pressing function is segmented from the friction generation function. The elastic element handles the pressing function with a controlled force, while the synchronizer ring's cone angle can be optimized for friction generation without being constrained by the need for high pressing forces, as the elastic element provides sufficient and controlled pressure.
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 solution enables smooth gear engagement by reducing frictional forces, requiring less effort to overcome static friction, and allows for faster synchronization with higher coefficients of friction, improving the overall shifting process.
Implementation Method 1
an elastic actuating element is provided which is effective between the sliding sleeve and the pressure piece
Implementation Method 2
a frictional torque is generated which must be overcome during engagement
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The invention relates to a synchronization system (10) for a change-speed gearbox comprising a synchronizing body (12) which is assigned to a gearbox shaft, and comprising a first and a second synchronizing ring (32, 34, 36, 38), which are assigned to a first and a second gear wheel (28, 30) respectively. Furthermore, the synchronizing ring (10) has a sliding sleeve (26) and at least one pressure piece (18), which is displaceably arranged on the synchronizing body (12) and is able to exert an axial compressive force on the corresponding synchronizing ring (32, 34, 36, 38). Moreover, the synchronizing ring (10) has a resilient actuating element (20), which acts between the sliding sleeve (26) and the pressure piece (18), a latching recess (50) for the neutral position and a ventilation contour (54) being provided on the sliding sleeve (26). The ventilation contour (54) can interact with the actuating element (20) in such a way that, when the sliding sleeve (26) is moved in order to engage with one of the gear wheels (28, 13), the pressure piece (18) is loaded away from the corresponding synchronizing ring (32, 34, 36, 38). The ventilation contour (54) has an axial length which is no more than twice the idle stroke of the sliding sleeve (26) between the neutral position and the position in which the corresponding synchronizing ring (32, 34, 36, 38) presses against a frictional surface assigned thereto.