Elastic End Stop Disc for Clutch Sleeve NVH Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing clutches for motor vehicles experience unacceptable noise (NVH) and uncontrollable movements due to hard end stops and complex hydraulic systems, particularly in multiple disc clutches and dual drive E-axles, leading to functional and safety issues.
Innovation Solution
A clutch system with an axially elastic end stop disc and hydraulic actuation is introduced, using a form-fit engagement instead of constant preload, incorporating a baffle plate and variable pressure chambers to control piston movement, and employing locking elements to stabilize the shift piston and sliding sleeve.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If hard end stops are used in the clutch system, then the piston movement is constrained and controlled, but unacceptable NVH noise is generated
Solution Approach 1:
The patent applies beforehand cushioning by introducing an elastic element (such as a spring or elastomeric material) between the piston and the hard end stop. This elastic element absorbs the impact energy before it reaches the hard end stop, cushioning the shock and preventing the generation of NVH noise while still providing the necessary movement constraint. The elastic element is pre-installed in the clutch system to prepare for and mitigate the harmful effects of piston impact against the end stop.
Solution Approach 2:
The patent uses an elastic element as an intermediary between the piston and the hard end stop. This intermediary component transfers the force from the piston while filtering out the high-frequency vibrations and shocks that would otherwise be transmitted directly to the clutch housing and generate noise. The elastic intermediary absorbs and dampens the mechanical energy, allowing the hard end stop to maintain its positioning function without producing unacceptable NVH.
2Ease of operation
If complex hydraulic systems with multiple valves are used, then precise control of piston movement is achieved, but device complexity and assembly difficulty increase
Solution Approach 1:
The patent extracts and removes the complex hydraulic valve system from the clutch design, retaining only the essential hydraulic actuation function. By taking out the unnecessary valves and complex control mechanisms, the system achieves sufficient piston control with a simplified hydraulic circuit. The extraction principle eliminates redundant components while preserving the core functionality of precise piston movement control through hydraulic pressure application.
Solution Approach 2:
Instead of using multiple valves to control piston movement in complex sequences, the patent inverts the approach by using a single hydraulic actuation point that applies pressure directly to the piston. The control logic is inverted from valve-based sequential control to direct hydraulic pressure control, simplifying the system while maintaining precision. The piston is controlled by the direction and magnitude of hydraulic force rather than by complex valve timing and positioning.
3Force
If constant preload is applied to discs in multiple disc clutches, then engagement force is maintained, but unwanted pressures and functional safety issues arise
Solution Approach 1:
The patent transitions from static constant preload to dynamic force application. Instead of maintaining continuous constant preload on the discs, the system applies hydraulic force dynamically only when engagement is required. The piston moves to apply disc spring force selectively, and the force is released when disengagement is needed. This dynamic approach maintains sufficient engagement force during operation while eliminating the continuous unwanted pressures that compromise functional safety and reliability.
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 reduces NVH noise and stabilizes piston movement, ensuring robust control and assembly, eliminating unwanted pressures and complex hydraulic valve requirements, while maintaining functional safety and simplifying assembly.
Implementation Method 1
an end stop disc (22) which is arranged axially between a locking ring (23) and a clutch body (24) and which is designed to be elastic in the axial direction
Implementation Method 2
having, for example, pressure connections (4, 5) between two pressure chambers (6, 7), each connected, for example, to one of the pressure connections (4, 5) so as to be axially displaceable due to pressure
Data Source
AI summary
The invention relates to a clutch (1) for coupling and uncoupling an engine to and from a motor vehicle drive train, said clutch comprising a piston (2) which is positioned in a housing (3) so as to be axially displaceable between two pressure chambers (6, 7) as a result of pressure, the piston (2) being connected to an actuation bell (8) which is designed to contact/move a sliding sleeve (9), an end stop disc (22) being provided which is elastic in the axial direction in order limit the axial displaceability of the sliding sleeve (9).