Shifting Device Actuating Body Spring Arrangement
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Solution Overview
Problem
Fully automatic stepped transmissions experience high drag torques and shifting force levels due to numerous friction points in multidisk clutches, leading to inefficiencies and complex constructions.
Innovation Solution
A shifting device with a synchronizer ring and multidisk clutch design where the actuating body is firmly connected to the second disk carrier, eliminating the need for axial movement and reducing shifting force by integrating a form-fit ring and friction ring for positive coupling, thereby simplifying the construction and reducing drag torques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the actuating body is urged into decoupled starting position by first spring means and third spring means, then the desired functionality of the shifting device is ensured, but the shifting force level becomes undesirably high
Solution Approach 1:
The invention removes the third spring means from the system. The actuating body is urged into the decoupled starting position by only the first spring means (actuating body spring element), eliminating the need for the third spring means (synchronizer spring element). This extraction of the redundant component directly reduces the shifting force level while maintaining the required functionality through the simplified spring arrangement.
2Strength
If numerous friction points are used in multidisk clutches for maximum torque transmission, then torque transmission capability is improved, but drag torques become quite high and transmission efficiency decreases
Solution Approach 1:
The invention segments the torque transmission function into two distinct mechanisms: the multidisk clutch for positive torque transmission and the synchronizer for speed synchronization. By separating these functions, the synchronizer with its smaller friction surfaces handles speed matching with minimal drag, while the multidisk clutch engages only when needed for torque transmission, significantly reducing overall drag torques during decoupled operation.
Solution Approach 2:
The synchronizer acts as an intermediary mechanism between the transmission shaft and the multidisk clutch. It performs speed synchronization through frictional coupling before the multidisk clutch engages for positive torque transmission. This intermediary function allows the multidisk clutch to remain decoupled during speed matching, minimizing drag torques while ensuring smooth engagement when torque transmission is required.
3Reliability
If the construction uses separate first spring means and third spring means for actuating body, then the desired functionality is ensured, but the construction becomes relatively complex
Solution Approach 1:
The invention extracts and removes the third spring means (synchronizer spring element) from the construction. The actuating body is simplified to be acted upon by only the first spring means (actuating body spring element), which directly reduces the number of components and simplifies the overall construction while maintaining the required shifting device functionality through the streamlined spring arrangement.
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 achieves lower drag torques and shifting force levels, enhancing transmission efficiency and simplifying the construction of the shifting device, while maintaining effective speed synchronization and torque transmission.
Implementation Method 1
a synchronizer which selectively provides for a decoupling, a frictional coupling or a positive coupling of the internal disk carrier with the transmission shaft
Implementation Method 2
an actuating body spring element (62) which on the one hand acts on the actuating body (30) and on the other hand acts on the first disk carrier (34)
Data Source
AI summary
A shifting device for a motor vehicle transmission includes several transmission shafts which each are rotatable about a transmission axis, a synchronizer ring which is firmly connected with a transmission shaft, a first disk carrier, a plurality of first disks which are non-rotatably and axially shiftably connected with the first disk carrier, a second disk carrier which is axially shiftable relative to the first disk carrier and in circumferential direction can be coupled with the synchronizer ring both frictionally and positively, a plurality of second disks which are non-rotatably and axially shiftably connected with the second disk carrier and form a multidisk clutch with the first disks, and an actuating body for axially pressurizing the second disk carrier, wherein the actuating body and the second disk carrier are rotatable relative to each other in circumferential direction and substantially are firmly connected with each other in axial direction.