Ramp System Actuating Friction Clutch via Leaf Spring
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Solution Overview
Problem
Existing friction clutch systems face challenges in securely closing with minimal design effort, particularly as they wear out, leading to varying contact pressure forces and actuating forces that are not consistently maintained.
Innovation Solution
A ramp system with an input ramp, a rotatable output ramp, and a leaf spring restoring mechanism that transmits torque tangentially to the radial plane, allowing for consistent actuating force and contact pressure force across the wear area of the friction linings by adjusting the angle of attack and axial extent, thereby compensating for increasing restoring forces due to wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional friction clutch system is used, then the clutch can be actuated, but the contact pressure force varies as the friction linings wear, leading to inconsistent actuating force
Solution Approach 1:
The restoring spring is designed to change its orientation dynamically as the friction linings wear. The angle of attack between the restoring spring and the radial plane increases with wear, which changes the force transmission characteristics. This dynamic adjustment compensates for the increasing restoring force due to wear, maintaining constant contact pressure force and actuating force throughout the service life of the friction linings.
Solution Approach 2:
The system changes the angle of attack parameter of the restoring spring as a function of wear. As the friction linings wear and the axial extent of the ramp system increases, the angle of attack increases, which changes the force ratio in the manner of an inclined toggle lever. This parameter change compensates for the increasing restoring force, maintaining constant actuating force over the service life.
2Force
If the axial extent of the ramp system increases due to wear, then the restoring force increases, but this leads to varying contact pressure force
Solution Approach 1:
The restoring spring's orientation is designed to change dynamically with the axial extent of the ramp system. As wear increases the axial extent, the angle of attack increases, which changes the force transmission. This dynamic adjustment ensures that despite the increasing axial extent and restoring force, the contact pressure force remains constant.
Solution Approach 2:
The angle of attack parameter is changed as a function of the axial extent of the ramp system. This parameter change compensates for the increasing restoring force that results from increased axial extent due to wear, maintaining constant contact pressure force throughout the service life.
3Reliability
If a ramp system with changing angle of attack is used, then consistent actuating force is achieved, but the device complexity increases
Solution Approach 1:
The restoring spring performs multiple functions: it restores the ramps to their initial position after actuation and simultaneously transmits torque while compensating for wear effects. By making the restoring spring serve multiple functions, the patent achieves consistent contact pressure force without adding separate compensation mechanisms, thereby limiting the increase in device complexity.
Solution Approach 2:
The patent merges the restoring function and the torque transmission function into a single component - the restoring spring. This spring both restores the ramps to their initial position and transmits torque while compensating for wear. By combining these functions, the patent achieves reliable consistent actuating force without significantly increasing device complexity.
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 solution ensures a secure and consistent closure of the friction clutch with minimal design effort, maintaining a constant actuating force and contact pressure force over the service life of the friction linings, enabling precise control and comfortable engagement/disengagement of the internal combustion engine in hybrid vehicles.
Implementation Method 1
a restoring spring connected to the input ramp and the output ramp and designed as a leaf spring for twisting the output ramp relative to the input ramp into a defined initial position
Implementation Method 2
a friction clutch with an input part (30) that can be coupled to a drive shaft (16) of an internal combustion engine, an output part (18) that can be coupled to a transmission input shaft, wherein the input part can be pressed with the output part via at least one friction lining (46) that is subject to wear
Data Source
Figure 1
Figure 2
AI summary
The invention relates to a ramp system for actuating a frictional clutch, in particular a wet or dry multiple disc clutch, for coupling a drive shaft of a motor vehicle engine to at least one transmission input shaft, having an entrance ramp for introducing an actuating torque, an exit ramp, which is rotatable relative to the entrance ramp, for opening and/or closing the frictional clutch and a reset spring, configured as a leaf spring and connected to the entrance ramp and the exit ramp, for rotating the exit ramp relative to the entrance ramp to a defined starting position, wherein at least one part of the torque transferred to the exit ramp can be transferred via the reset spring, wherein the reset extends between a torque initiation point of the entrance ramp and a torque exit point of the exit ramp, substantially in the tangential direction, and extends at a setting angle to a radial plane of the ramp system, wherein the reset spring allows an increase of the actuating force on the exit ramp in the case of an increase of the axial extension of the ramp system. By also using the reset spring, which extends tangentially at an angle to the radial plane, for torque transfer, a pressing force which decreases as the friction linings wear can at least be compensated by a modification of the direction of force of the torque introduced via the reset spring such that a secure closing of a frictional clutch is enabled, requiring only a small amount of design effort, wherein a particularly comfortable coupling of an internal combustion engine to a drive train of a hybrid motor vehicle is in particular simultaneously enabled.