Seal Ring With Inclined Surface For Low Torque
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing seal rings face challenges in maintaining low torque generation performance at both high and low-speed rotations, with issues of oil film formation, sliding contact area, and torque increase due to wear, particularly in applications like automatic transmissions and continuously variable transmissions.
Innovation Solution
A seal ring design featuring an inclined outer diameter surface and V-shaped concave portions on the inner diameter side, with a specific inclined angle and concave portion configuration to minimize initial torque and prevent torque increase with wear, ensuring consistent low torque generation and sealing performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the seal ring uses a conventional design with a projected portion in the flow path, then dynamic pressure generation is improved at high-speed rotation, but oil film formation effect disappears at low-speed rotation
Solution Approach 1:
The side surface of the seal ring is segmented into multiple inclined surfaces with different inclination angles. The first inclined surface has a larger inclination angle to generate dynamic pressure at high-speed rotation, while the second inclined surface has a smaller inclination angle to maintain oil film formation at low-speed rotation. This segmentation allows the seal ring to adapt to different rotation speeds effectively.
Solution Approach 2:
Different portions of the side surface are given different local qualities through varying inclination angles. The first inclined surface (with larger angle) is optimized for high-speed operation, while the second inclined surface (with smaller angle) is optimized for low-speed operation. This local quality differentiation ensures optimal performance across the entire rotation speed range.
2Reliability
If the seal ring has a large sliding contact area, then sealing performance is improved, but torque generation increases
Solution Approach 1:
The inclination angle parameter of the side surface is changed to optimize the balance between sealing performance and torque. By using inclined surfaces instead of a perpendicular side surface, the contact pressure is redistributed, maintaining adequate sealing while reducing the frictional force and resulting torque generation.
3Force
If the seal ring uses a tapered surface design, then low torque generation is achieved, but sliding contact area is reduced
Solution Approach 1:
The side surface is segmented into multiple inclined surfaces with different inclination angles rather than using a single uniform tapered surface. This segmentation allows the seal ring to maintain a larger effective sliding contact area while still benefiting from the torque-reducing effects of the inclined surfaces, particularly the second inclined surface with its smaller inclination angle.
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 seal ring achieves excellent low torque generation and sealing performance over a long term by controlling the sliding contact area and oil flow, maintaining low friction and preventing torque increase due to wear, even with progressive wear of the inclined surface.
Implementation Method 1
A seal ring which... slidably contacts a side wall surface of the annular groove... An outer diameter side of the side surface of the ring is formed as an inclined surface... to decrease a width of the ring from an outer diameter side to an inner diameter side
Implementation Method 2
A V-shaped concave portion which does not contact the side wall surface of the annular groove and communicates with an inner circumferential surface of the ring is formed on a portion of an inner diameter side of the side surface of the ring
Implementation Method 3
The sealing surfaces of both seal rings holding the hydraulic pressure of the hydraulic oil between both seal rings
Data Source
AI summary
The present invention provides a seal ring capable of maintaining excellent low torque generation performance for a long term. A seal ring (1) is mounted on an annular groove formed on one member consisting of either a housing having a shaft hole or a rotary shaft inserted into the shaft hole, partly projects from the annular groove and contacts a surface of other member consisting of either the housing or the rotary shaft, and slidably contacts a side wall surface of the annular groove at a non-sealed fluid side thereof, thereby sealing an annular gap between the one member and the other member. An outer diameter side (2a) of the side surface (2) of the ring to be subjected to at least the side wall surface of the annular groove is formed as an inclined surface having an inclined angle in such a way as to decrease a width of the ring from the outer diameter side of the side surface of the ring to an inner diameter side of the side surface thereof. A concave portion (3) which does not contact the side wall surface of the annular groove and communicates with an inner circumferential surface (1b) of the ring is formed on a portion of the inner diameter side (2b) of the side surface of the ring not projecting from the annular groove.