Clutch Disc Tooth Recesses for Low-Drag Oil Return
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
State-of-the-art oil-flooded multi-plate clutches in commercial vehicles experience undesirable torque transfer due to oil viscosity during frequent engagement and disengagement, leading to drag performance issues and wear problems when increasing the oil return cross-section to reduce drag.
Innovation Solution
The clutch disc design incorporates recesses in the radially outer peripheral edges of the teeth to increase the oil return cross-section without reducing the contact area, thereby enhancing oil flow and minimizing wear, while maintaining torque transmission efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the oil return cross-section is increased to reduce drag, then oil flow is enhanced and drag is reduced, but the contact area between teeth and grooves is reduced leading to increased wear
Solution Approach 1:
The tooth structure is segmented by introducing recesses that divide the tooth into distinct regions. The recesses create separate zones for oil return while preserving the lateral flanks for torque transmission, allowing the tooth to simultaneously facilitate oil flow and maintain contact area for wear resistance
Solution Approach 2:
Different regions of the tooth are given different functions through local quality modification. The lateral flanks maintain full contact area for torque transmission and wear resistance, while the recesses in the radially outer peripheral edge provide dedicated oil return pathways. This spatial differentiation of functions resolves the contradiction between drag reduction and wear prevention
2Loss of energy
If the lateral flanks of teeth are shortened to increase oil return cross-section, then oil flow is improved and drag is reduced, but the contact area for torque transmission is reduced
Solution Approach 1:
Instead of reducing the lateral flanks in the radial direction (which would affect torque transmission), the recesses are positioned in the circumferential direction at the radially outer peripheral edge. This dimensional relocation allows oil return enhancement without compromising the torque-transmitting contact area of the lateral flanks
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 reduces drag and wear by optimizing oil flow without increasing manufacturing costs, ensuring efficient torque transmission and durability.
Implementation Method 1
oil flows between the individual clutch discs and friction discs from radially inside to radially outside (due to centrifugal force) to absorb and dissipate frictional heat
Implementation Method 2
undesirable torque transfer between them due to the viscosity of the oil
Data Source
Figure 1~1a
Figure 2~3
Figure 4~4a
AI summary
The invention relates to a clutch disc (1) or friction disc for effecting a reduced drag resistance, comprising: - a plurality of radially outwardly protruding teeth (Z) having lateral flanks (11, 13) for transmitting a torque between the clutch disc (1) or friction disc and grooves (N) which are provided in a clutch case (2) and which have lateral flanks (21, 23), and radially outer peripheral edges (22) connecting same, wherein each tooth (Z) of the clutch disc (1) has a radially outer peripheral edge (12) connecting the lateral flanks (11, 13) thereof, and an oil return cross-section (Ar) is formed between this peripheral edge (12) of a tooth (Z) and the lateral flanks (21, 23) of a groove (N) and the radially outer peripheral edge (22) of the groove (N), wherein a total oil return cross-section is composed of the individual oil return cross-sections (Ar) at each groove (N), wherein the peripheral edge (12) of at least one tooth (Z*) of the clutch disc (1) or friction disc has a recess (12*) in order to form an enlarged oil return cross-section (Ar*).