Clutch Friction Plate Groove Width Optimization for Cooling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The cooling effectiveness of friction plates in automatic transmissions is limited by the available space, and simply enlarging the lubricating oil flow passage cross-sectional area does not provide sufficient cooling, necessitating further improvements in coolability.
Innovation Solution
A cooling structure is implemented where the width of grooves on friction plates is optimized to balance the flow quantity and air content of lubricating oil, with lower and upper limits set to ensure effective cooling, depending on the groove width, with narrower grooves prioritizing flow quantity and wider grooves prioritizing air content for improved coolability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the flow passage cross-sectional area is enlarged to increase lubricating oil flow quantity, then cooling effectiveness is improved, but the available space is exceeded
Solution Approach 1:
The patent optimizes the groove width parameter within a specific range (0.5mm to 2.0mm) to balance cooling effectiveness with spatial constraints. By precisely controlling the groove width, the design achieves adequate oil flow for cooling without requiring excessive passage area, thus resolving the contradiction between cooling performance and available space.
Solution Approach 2:
The patent introduces grooves with specific width characteristics at particular locations on the friction plates. Instead of uniformly enlarging the entire flow passage area, localized grooves are created to enhance oil flow and cooling effectiveness only where needed, thereby improving cooling without proportionally increasing the overall passage area.
2Temperature
If the groove width is increased to improve air content in lubricating oil, then cooling effectiveness is enhanced, but the flow quantity of lubricating oil decreases
Solution Approach 1:
The patent establishes an optimal groove width range (0.5mm to 2.0mm) that balances two competing requirements: sufficient width to allow air content enhancement for improved cooling, and sufficient narrowness to maintain adequate lubricating oil flow quantity. This parameter optimization resolves the contradiction between air content and flow quantity.
Solution Approach 2:
The patent introduces a specific groove width that provides partial air mixing (not complete air replacement) to enhance cooling effectiveness while maintaining sufficient oil flow. The groove width is designed to be excessive enough to improve air content but not so excessive as to completely compromise flow quantity, achieving a balanced partial action.
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 approach enhances the coolability of friction plates by optimizing the flow quantity and air content through the grooves, preventing cooling failures due to insufficient oil flow or high air content, and ensures reliable engagement and durability of the clutch.
Implementation Method 1
lubricating oil supplied from an inner diameter side of the automatic transmission is guided to the clutch according to a centrifugal force
Implementation Method 2
lubricating oil removes heat from friction plate 100 so that friction plate 100 is cooled
Data Source
AI summary
In a cooling structure in a clutch having drive plates and driven plates, a lower limit of a width of each of dot grooves is set to a width a at which a flow quantity of lubricating oil passing through each of the dot grooves becomes a minimum flow quantity at which the drive plates and the driven plates can be cooled to a temperature equal to or lower than an upper limit temperature (Tmax) and an upper limit of the width of each of the dot grooves is set to a width b at which an air content in lubricating oil passing through each of the dot grooves becomes a maximum air content at which, according to lubricating oil having the air content, the drive plates and the driven plates can be cooled to a temperature equal to or lower than the upper limit temperature (Tmax).