Wet-Running Paper Friction Surface for Lower Drag Torque
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Solution Overview
Problem
Conventional wet-running friction parts lack effective design features to manage friction regions for enhanced performance, leading to increased drag torque and reduced static friction levels, especially in multi-plate clutches and multiple-disc brakes.
Innovation Solution
The friction part incorporates annular-disc-like friction surfaces made from paper material with meso-geometric or micro-geometric uneven portions, creating axially deep and high friction regions with controlled preloading, allowing for increased oil film thickness and reduced drag torque without the need for corrugated springs, achieved through conical, double-conical, or spherical designs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional wet-running friction parts use flat friction surfaces, then manufacturing is simple, but drag torque increases and static friction levels decrease
Solution Approach 1:
The friction surface is designed with locally differentiated zones: axially deep friction regions and axially high friction regions with different preloading characteristics. This local quality variation allows the surface to exhibit different friction behaviors in different areas, reducing overall drag torque while maintaining effective friction transmission.
Solution Approach 2:
The friction surface incorporates curved geometries including conical and spherical shapes instead of flat surfaces. These curved surfaces create varying contact pressures and oil film distributions, leading to reduced drag torque and improved friction characteristics compared to conventional flat surfaces.
2Device complexity
If conventional wet-running friction parts use flat friction surfaces, then structure is simple, but static friction level is reduced
Solution Approach 1:
The friction surface is designed with locally differentiated zones: axially deep friction regions and axially high friction regions with different preloading characteristics. This local quality variation allows the surface to exhibit different friction behaviors in different areas, reducing overall drag torque while maintaining effective friction transmission.
Solution Approach 2:
The friction surface incorporates curved geometries including conical and spherical shapes instead of flat surfaces. These curved surfaces create varying contact pressures and oil film distributions, leading to reduced drag torque and improved friction characteristics compared to conventional flat surfaces.
3Ease of manufacture
If conventional wet-running friction parts lack uneven portions, then manufacturing is easy, but oil film thickness control is insufficient
Solution Approach 1:
The friction surface is designed with locally differentiated zones: axially deep friction regions and axially high friction regions with different preloading characteristics. This local quality variation allows the surface to exhibit different friction behaviors in different areas, reducing overall drag torque while maintaining effective friction transmission.
Solution Approach 2:
The friction surface incorporates curved geometries including conical and spherical shapes instead of flat surfaces. These curved surfaces create varying contact pressures and oil film distributions, leading to reduced drag torque and improved friction characteristics compared to conventional flat surfaces.
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 enhances the static friction level and reduces drag torque, facilitating easier air penetration and uniform energy input, thereby improving the performance and efficiency of frictionally operating devices like multi-plate clutches and multiple-disc brakes.
Implementation Method 1
The surface of the paper material can, for example, be conical, e.g., with a single cone or double-conical, or spherical
Implementation Method 2
The surface of the paper material can, for example, be conical, e.g., with a single cone or double-conical, or spherical
Implementation Method 3
at least one axially high friction region which is more strongly preloaded than the axially deep friction region when the friction surface and the mating surface are axially pressed together
Implementation Method 4
an oil film thickness in the friction contact region can be increased by a suitable design of the friction surface between the axially deep friction region and the axially high friction region, which in turn leads to a higher level of friction
Implementation Method 5
the deep friction region(s) lead to a forced separation from the mating surface when the contact pressure is removed. This makes it easier for air to enter the friction gap
Data Source
AI summary
A friction part for a frictionally operating device includes an annular-disc-like friction surface rotatable about a rotational axis in a wet-running manner relative to a mating surface. The annular-disc-like friction surface is formed from a paper material and includes a meso-geometric or a micro-geometric uneven portion in order to create an axially deep friction region and an axially high friction region in the annular-disc-like friction surface. The axially high friction region is more strongly preloaded than the axially deep friction region when the annular-disc-like friction surface and the mating surface are axially pressed together.