Friction Clutch Servo Spring Segmentation and Bead Bearing
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Solution Overview
Problem
Conventional friction clutches with servo springs face issues due to limited bearing surface, increased actuation force due to wear, and stress at contact points, leading to undesirable hysteresis and mechanical load.
Innovation Solution
The servo spring is designed with separate support and centering tongues, and a clutch cover with a bead-based bearing elevation, allowing for increased support radius and reduced contact pressure, minimizing hysteresis and mechanical stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the support tongue and centering tongue are formed as separate components, then the bearing surface area is increased and contact pressure is reduced, but the device complexity increases
Solution Approach 1:
The support tongue and centering tongue are divided into separate components. The support tongue rests on the counter bearing to limit axial travel, while the centering tongue rests on the radial guide to center the servo spring. This segmentation increases the bearing surface area and reduces contact pressure at each interface.
2Duration of action of moving object
If the friction disc loses material thickness due to wear, then the engagement travel of the pressure plate increases, but the actuation force required to disengage the clutch increases
Solution Approach 1:
The servo spring is pre-loaded to exert a counterforce on the diaphragm spring before wear occurs. As the friction disc wears and engagement travel increases, the servo spring's counterforce increases proportionally, compensating for the increased actuation force required and maintaining consistent pedal force throughout the service life.
3Ease of operation
If the servo spring is positioned to exert counterforce when new, then the pedal force is reduced, but the counterforce becomes insufficient when wear occurs
Solution Approach 1:
The servo spring is designed with dynamic characteristics where its counterforce varies with the engagement travel of the pressure plate. When the clutch is new, the servo spring exerts minimal counterforce. As wear increases and engagement travel increases, the servo spring expands further and exerts increasing counterforce, maintaining optimal pedal force throughout the service life.
4Volume of moving object
If the support radius is smaller than the thickness of the clutch cover material, then the bearing elevation is compact, but the manufacturing precision requirements increase
Solution Approach 1:
The support projection is formed as a bead with a curved surface rather than a flat surface. This spherical/curved geometry provides optimal contact for the support tongue while fitting within the compact thickness of the clutch cover, reducing the effective support radius while maintaining bearing capability.
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 maintains consistent actuation force over the clutch's service life, reduces mechanical load, and allows for a smaller, more efficient friction clutch with improved manufacturing tolerances.
Implementation Method 1
a spring section (3) for maintaining a servo force for a disc spring (4)
Implementation Method 2
at least one friction package (18) with at least one pressure plate (28) and at least one corresponding friction disc (29), via which a torque can be transmitted in the pressed state
Data Source
Figure 1~4
Figure 5~6
Figure 7~9
AI summary
The invention relates to a friction clutch comprising a servo spring. The servo spring is characterized above all in that the support tongue and the centering tongue are formed by separate components. The support tongue is preferably arranged on an outer radius in the mounted state, and the centering tongue is arranged on an inner radius, the outer radius being greater than the inner radius. According to another aspect of the invention, a friction clutch is proposed with a clutch cover. The clutch cover is characterized above all in that the support elevation is formed by means of a bead with a support radius, wherein the support radius is preferably smaller than the thickness of the material of the clutch cover. By using the proposed servo spring and a corresponding clutch cover, a longer service life of the disc spring and a greater manufacturing tolerance with the same required installation space are achieved.