Composite Brake Disc Tabs for Thermal Expansion Compensation
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Solution Overview
Problem
The connection between friction rings and the brake disc hub in composite brake discs for commercial vehicles can lead to shielding due to differing coefficients of expansion, resulting in hotspots and increased heat cracking during braking.
Innovation Solution
A composite brake disc design featuring pot-shaped connecting elements with axially extending tabs, where the tabs have a U-shaped bend and beads to adjust rigidity, allowing for compensation of thermal expansion and improved ventilation through flow tabs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If tabs are used to connect the brake disc hub to the friction rings, then the connection is simplified and easy to manufacture, but shielding occurs due to different coefficients of expansion causing hotspots and heat cracking
Solution Approach 1:
The connection element is divided into multiple tabs that extend radially outward, with each tab independently connected to the friction ring. This segmentation allows differential thermal expansion of each tab without creating shielding effects, as the tabs can expand and contract independently rather than as a rigid unified structure.
Solution Approach 2:
The tabs are designed with flexible connections that allow dynamic adjustment during thermal cycles. The connection between the tabs and friction ring permits controlled movement and deformation, enabling the structure to adapt to thermal expansion differences between the metal hub and ceramic friction rings, thereby preventing hotspot formation.
2Stability of the object's composition
If the connection between the hub and friction rings is made rigid, then structural stability is improved, but thermal expansion differences cause shielding and hotspots
Solution Approach 1:
The connection element uses material composition and geometric parameters that allow controlled flexibility. The tabs are designed with specific thickness, length, and cross-sectional characteristics that provide sufficient structural stability during operation while permitting thermal expansion. The material parameters are selected to bridge the gap between rigid stability and flexible thermal adaptation.
3Device complexity
If tabs extend radially towards the friction rings, then the connection structure is simplified, but shielding occurs during braking due to thermal expansion differences
Solution Approach 1:
The radial connection structure is segmented into multiple discrete tabs rather than a continuous rigid connection. Each tab acts as an independent thermal expansion element, simplifying the overall connection structure while eliminating shielding effects through the segmented design that allows differential movement.
4Object-affected harmful factors
If the tabs are made more flexible to compensate for thermal expansion, then shielding is reduced, but connection rigidity decreases
Solution Approach 1:
The tab geometry parameters (thickness, length, cross-section) are optimized to achieve the desired balance between flexibility and rigidity. The parameters are specifically designed so that the tabs are flexible enough to accommodate thermal expansion differences and prevent shielding, while maintaining sufficient rigidity to provide stable structural connection during braking operations.
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 effectively prevents shielding and heat cracking by adapting to thermal expansion, enhancing the connection's stiffness and ventilation, thereby increasing the service life of the brake disc.
Implementation Method 1
due to the different coefficients of expansion of the different materials. Due to the shielding, so-called hotspots can occur during a braking process
Implementation Method 2
the tabs extending axially through the axis of rotation of the composite brake disc on a lateral surface of the connecting element make it possible to adapt the rigidity of the connection so that any tension that may arise as a result of the heating of the friction rings can be compensated for
Data Source
Figure 1
Figure 2
Figure 3~5
AI summary
A composite brake disc for a disc brake of a commercial vehicle has two friction rings, at least one cup-shaped or neck-shaped connector element (4) which extends axially from an inner circumference of the friction rings to a rotational axis of the composite brake disc for fastening the composite brake disc to a wheel axle, wherein the connector element (4) has a circumferential surface (5), from the one end-side edge of which a multiplicity of first and second tongues (6, 7) extend, the ends (8, 9) of which are received in an alternating manner in the friction rings, wherein the ends (8) of the first tongues (6) are cast into a first friction ring which is close to the circumferential surface (5) of the connector element (4), and the ends (9) of the second tongues (7) are cast into a second friction ring which is remote from the circumferential surface (5) of the connector element (4), wherein the tongues (6, 7) extend away from the circumferential surface (5) of the connector element (4) axially with respect to the rotational axis of the composite brake disc, wherein the first tongues (6) have a U-shaped bend (10) in a region between the circumferential surface (5) of the connector element (4) and the ends (8) which are received in the friction ring.