Servo Clutch Hub Tracks for Wear-Resistant Slipper Operation
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Solution Overview
Problem
Existing hub units for vehicle clutches with handlebars face issues such as wear and short service life due to conjugate flat inclined faces, which lead to specific element requirements and imprecise tolerances, preventing economies of scale and smooth operation.
Innovation Solution
A servo hub unit with a movable disc pressure flange and inclined tracks allows for interchangeable designs, reducing wear through appropriate material choice and lubrication, and features a rotatable pin for smooth torque conversion between servo and slipper functions, enhancing compactness and user experience.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If flat inclined faces are used for servo and slipper functions, then the clutch can perform both functions, but wear increases and service life decreases
Solution Approach 1:
The single conjugate face is segmented into two separate tracks: a first track for servo function and a second track for slipper function. This segmentation allows each track to be optimized for its specific function, reducing wear and extending service life while maintaining both clutch functions.
Solution Approach 2:
The hub unit incorporates both servo and slipper functions through a unified structure with multiple tracks, allowing a single component to perform multiple functions. This universal design maintains adaptability while improving durability through separate optimized tracks.
2Ease of manufacture
If conjugate flat inclined faces are used, then the clutch can operate, but manufacturing precision decreases due to casting limitations
Solution Approach 1:
The flat inclined faces are replaced with curved tracks having specific radii of curvature. This curvature allows for better manufacturing precision through casting while maintaining the required functional performance, as curved surfaces are more amenable to precise mold fabrication and casting processes.
3Adaptability or versatility
If different models require specific elements, then the clutch can be optimized for each model, but economies of scale are lost
Solution Approach 1:
The hub unit is designed as a universal component with standardized tracks and dimensions that can accommodate different engine and vehicle models. This universality enables production of a single design for multiple applications, achieving economies of scale while maintaining model-specific optimization through adjustable parameters.
Solution Approach 2:
While maintaining the same fundamental design and track geometry, specific parameters such as track angles, dimensions, and positions can be adjusted to optimize performance for different vehicle models. This parameter variation allows model-specific optimization without requiring completely different components.
4Ease of operation
If the pin is positioned far from tracks, then the flange can move freely, but angular play increases reducing smoothness
Solution Approach 1:
The pin is positioned at an optimized location relative to the tracks, maintaining appropriate clearance for free flange movement while minimizing angular play. This local optimization of pin position balances operational freedom with smoothness, reducing harmful angular play in the critical transition zones between servo and slipper functions.
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 extends the service life of the hub unit, enables interchangeable designs for different vehicles, and improves the smoothness of transitions between servo and slipper operations, reducing wear and maintaining efficient torque transfer.
Implementation Method 1
At least one spring to press the flange towards the stop and arranged against a stop rigidly connected to the hub
Implementation Method 2
the first track having a first inclination such as to convert a first torque applied to the flange by the discs into a first axial load applied by the flange to press the discs against the stop and have a servo effect when closing the clutch
Implementation Method 3
the second track having a second inclination such as to convert a second torque applied by the hub into a second axial load applied to move off the flange from the axial stop to disengage the discs and allow a slipper function
Implementation Method 4
a plurality of friction discs
Data Source
AI summary
A hub unit for a clutch of a vehicle with a handlebar has both a servo function when closing and a slipper function via the sliding motion of at least one pin along respective inclined and facing tracks. The hub unit includes a hub connected to an output shaft of a vehicle engine and having an axis of rotation, a plurality of guides rigidly connected to the hub, an axial stop rigidly connected to the hub, a disc pressure flange movable in a direction parallel to the guides, and at least one spring. The hub defines at least a first track and a second track facing in an axial direction and arranged in a direction not parallel to the axis of rotation. The disc pressure flange includes at least one pin projecting in a substantially radial direction and arranged in contact with the first track and the second track.