Cross-Linked Friction Lining Bonding for High-RPM Friction Disks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing bonding processes for friction discs lack sufficient strength to resist radial and tangential shear stresses, particularly under high centrifugal forces and temperatures, which can lead to bond failure and reduced durability in applications like motor vehicle clutches and brake discs.
Innovation Solution
A friction disk with a solvent-free powder glue comprising a solid phenolic resin, a fluidizing agent, and a catalyst, applied in a crosslinked state to a support disk, providing enhanced resistance to centrifugal forces and shear stresses through improved adhesion and porosity, allowing the glue to effectively interact with the friction lining and support disk.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a solvent-based adhesive is used to bond the friction lining to the support disc, then the bonding process is easier to perform, but the bond strength under shear stress and centrifugal force is insufficient
Solution Approach 1:
The patent changes the physical and chemical parameters of the adhesive system by using a solvent-free powder adhesive instead of solvent-based adhesive. This involves changing the adhesive from liquid to powder form, eliminating the solvent component, and adjusting the application parameters (temperature, pressure, time) to achieve proper bonding. The solvent-free formulation fundamentally alters the bonding mechanism while maintaining ease of application through powder coating techniques.
Solution Approach 2:
The patent employs a composite adhesive system consisting of powder adhesive particles embedded in a friction lining material. This composite structure allows the adhesive to be distributed throughout the lining matrix, creating multiple bonding interfaces between the lining and support disc. The composite nature enhances bond strength by distributing shear stresses across numerous adhesive bonds rather than relying on a single adhesive layer.
2Ease of manufacture
If a solvent-based adhesive is used, then the adhesive can be easily applied, but it releases harmful solvents and creates environmental concerns
Solution Approach 1:
The patent extracts and removes the harmful solvent component from the adhesive system, retaining only the beneficial binder particles. By eliminating the solvent carrier, the system avoids VOC emissions and environmental pollution while maintaining adhesive functionality. The solvent-free powder adhesive is applied directly without requiring solvent evaporation, thus removing the source of harmful emissions.
Solution Approach 2:
The patent converts the potential harm of solvent-based adhesives into a benefit by using the powder form's inherent advantages. The powder adhesive can be applied as a thin, uniform layer that provides sufficient bonding strength without requiring solvents. This approach transforms the limitation of powder application (difficulty in achieving uniform coating) into a benefit by creating a more controlled, environmentally friendly process with precise material deposition.
3Device complexity
If the friction lining is bonded without cross-linking, then the bonding process is simpler, but the bond fails under high centrifugal force and temperature
Solution Approach 1:
The patent applies the adhesive in a preliminary uncured state that allows for proper positioning and initial bonding, then completes the cross-linking process during a subsequent heating phase. This preliminary action enables the adhesive to establish initial contact and adhesion before the full cross-linked structure develops, ensuring proper alignment and bond formation without requiring complex real-time monitoring during the curing process.
Solution Approach 2:
The patent utilizes the phase transition of the powder adhesive from uncured to cross-linked state through thermal curing. The adhesive transitions from a soft, deformable powder layer that can conform to surface irregularities to a rigid, cross-linked network that provides high mechanical strength. This phase transition occurs during the friction disc manufacturing process, where heat and pressure are applied to complete the curing, transforming the adhesive properties to match the operational requirements.
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 significantly enhances the resistance to radial and tangential shear stresses and centrifugal forces, ensuring the bond remains intact even at high temperatures and rotations, such as 15,000 rpm at 200°C, and reduces environmental concerns associated with solvent-based adhesives.
Implementation Method 1
a mass percentage of catalyst less than 7% and greater than or equal to 3%
Implementation Method 2
The adhesive used to bond the friction lining to one of the faces of the support disc
Implementation Method 3
the bonding of the friction lining in the cross-linked state to said face of the support disc resists a centrifugal force corresponding to a rotation of 15000 rpm at a temperature of 200°C
Data Source
Figure 1
AI summary
The invention relates to a friction disk (10) comprising a support disk (12) and a friction lining (14) glued in the cross-linked state to one of the surfaces of the support disk, characterised in that the gluing of the friction lining in the cross-linked state to the surface of the support disk can withstand a centrifugal force corresponding to a rotation of 15000 rpm at a temperature of 200°C.