Friction Clutch Tangential Leaf Spring Torque Transmission
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Solution Overview
Problem
Existing friction clutches face challenges in reliable engagement with minimal engineering effort and expense, particularly at high torques and with worn friction linings, as they require additional power transmission devices and complex constructions.
Innovation Solution
A friction clutch design featuring a tangentially running leaf spring that acts as both a positioning mechanism and a torque transmitter, changing its angle of incidence to adjust the pressing force on the friction linings, allowing for increased torque transfer without additional power devices, and compensating for wear by altering the force direction, ensuring consistent actuation force over the clutch's life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If additional power transmission devices (such as ramp systems) are added to increase torque transfer capability, then the torque transfer capability is improved, but the device complexity and construction expense increase
Solution Approach 1:
The return spring is designed to perform multiple functions: it provides the pressing force necessary for clutch engagement and simultaneously acts as a power transmission device to transfer torque from the input part to the output part. This multi-functionality eliminates the need for separate ramp systems or additional power transmission devices, thereby maintaining reliable engagement at high torques while avoiding increased construction complexity
Solution Approach 2:
The invention merges the return spring with the power transmission function by allowing the spring to run obliquely between the input part and output part. This combination integrates two previously separate functions (positioning/pressing and torque transmission) into a single component, resolving the contradiction between reliability at high torque and device complexity
2Reliability
If the pressing force is increased to maintain engagement with worn friction linings, then the torque transfer capability is improved, but the force required to operate the clutch increases
Solution Approach 1:
The return spring is designed with an oblique angle of incidence that is not fixed but changes dynamically as the pressing part moves axially. This dynamic angle allows the spring to provide varying pressing forces throughout the engagement stroke, maintaining high pressing force with worn linings while keeping the actuation force within acceptable limits through the mechanical advantage of the changing angle
3Device complexity
If a tangentially running return spring is used to transfer torque, then the construction simplicity is improved, but the understanding and analysis of force distribution becomes more difficult
Solution Approach 1:
The invention employs a return spring with a specific oblique angle of incidence that changes as a parameter during operation. This parameter change (the angle) allows the spring to effectively transfer torque while maintaining construction simplicity. The force distribution, while complex, follows predictable mechanical principles that can be analyzed through the changing angle parameter
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
This design enables reliable engagement of the friction clutch at high torques and with worn linings, reducing construction complexity and costs, while maintaining comfortable and precise coupling of an internal combustion engine to a hybrid vehicle drivetrain.
Implementation Method 1
a return spring in the form of a leaf spring to position the pressing part in a defined initial position relative to the input part, at least a part of the torque transferred by the input part being transferable through the return spring
Implementation Method 2
the angle of incidence of the return spring which is transferring at least part—in particular a large part—of the torque introduced through the input part when the motor vehicle motor is in traction mode, can change. Because of the increasing or decreasing angle of incidence, the ratio of forces on the return spring change in the manner of an obliquely operated knee lever
Implementation Method 3
a pressing part which is movable axially relative to the input part and to the output part, in particular an input disk carrier, to press the output part together frictionally with the input part
Data Source
AI summary
A friction clutch for coupling a drive shaft of a motor vehicle motor to a transmission input shaft has an input part coupled to the drive shaft to introduce a torque of the drive shaft, an output part coupled to the transmission input shaft to extract a torque, a pressing part movable axially relative to the input part and to the output part to press the output part together frictionally with the input part, and a return spring in the form of a leaf spring to position the pressing part in a defined initial position relative to the input part, at least a part of the torque transferred by the input part being transferable through the return spring, where the return spring runs between a torque introduction point and a torque extraction point in an essentially tangential direction and runs at an oblique angle of incidence relative to a radial plane of the friction clutch.