Automotive Clutch Lever with Curved Cam Track
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Solution Overview
Problem
Existing lever systems for actuating clutches in motor vehicle drive trains experience significant fluctuations in axial force and torque due to the displacement path, and the functional relationship between clutch opening and displacement is dependent on spring characteristics and wear, leading to inconsistent performance over the service life.
Innovation Solution
A lever system with a rotatably mounted lever connected to a cam track on a radially displaceable carriage, where the cam track's curved shape ensures a predetermined proportional relationship between the carriage displacement path and the pressing means displacement path, independent of spring characteristics and wear, thereby stabilizing the clutch opening path and force transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the lever is mounted on the housing side with axial displacement or rotatable mounting, then the release force can be adjusted, but the axial force on the spindle fluctuates greatly over the displacement path
Solution Approach 1:
The invention employs a cam track with a specifically curved geometry to guide the support point of the lever. This curved path transforms the linear spindle displacement into a nonlinear lever movement, ensuring that the axial force on the spindle remains constant throughout the displacement path. The curvature of the cam track is precisely designed to compensate for the varying mechanical advantage of the lever system.
Solution Approach 2:
The invention changes the geometric parameters of the cam track to achieve the desired force characteristics. By carefully selecting the curvature and shape of the cam track, the system maintains a predetermined relationship between the displacement of the pressing means and the displacement of the carriage, thereby stabilizing the axial force while allowing release force adjustment.
2Force
If the support point is shifted to change the release force, then the force can be adjusted, but the functional relationship between shifting distance and clutch opening distance fluctuates over service life due to spring characteristics and wear
Solution Approach 1:
The cam track's curved geometry is designed to decouple the functional relationship between carriage displacement and clutch opening distance from the spring characteristics. The curved path ensures a predetermined geometric relationship that remains constant regardless of spring aging or lining wear, providing reliable and repeatable clutch actuation throughout the service life.
Solution Approach 2:
Instead of relying on spring characteristics to determine the functional relationship, the invention inverts the approach by using a geometrically defined cam track to establish the relationship. This reverses the dependency from material properties (springs) to geometric properties (cam track shape), which are more stable and predictable over time.
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 maintains a consistent relationship between clutch opening and carriage displacement, independent of spring aging or clutch lining wear, and allows for a predetermined force function along the displacement path, reducing torque fluctuations and ensuring stable clutch operation throughout the service life.
Implementation Method 1
the lever with a bearing point located on a cam track on a radially displaceable carriage which can be displaced by means of a motor-driven spindle, the cam track having such a curved shape that the displacement path of the pressing means is a predetermined function of the displacement path of the carriage
Data Source
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AI summary
The clutch coupling used on an automobile drive train has a lever [7] with a profiled shape that moves about an adjustable fulcrum [12] on a slide [10] with one end operating the clutch discs [3]. The slide is moved by an electric motor to control the force [Fy] applied to the plates as movement progresses.