Seal Ring V-Shaped Concave Portions Low Torque Oil Seal
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Solution Overview
Problem
Existing seal rings face challenges in maintaining effective oil sealing and low torque generation performance, particularly at low-speed rotations, with issues of oil film formation and frictional loss, and have limitations in concave portion design affecting sliding contact area and oil flow.
Innovation Solution
A seal ring design featuring V-shaped concave portions with a steep gradient boundary and rounded ends, made of synthetic resins like PPS or PEEK, which allows hydraulic oil to flow easily to the sliding contact surface, reducing oil leak and torque generation while maintaining sealing effectiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a projected portion is formed in the middle of the flow path to generate dynamic pressure, then oil film formation is improved at high-speed rotation, but oil film formation effect hardly appears at low-speed rotation
Solution Approach 1:
The sliding contact surface is divided into multiple concave portions (oil reservoirs) spaced at specific intervals, creating segmented oil supply zones. This segmentation allows oil to be supplied to multiple locations simultaneously, ensuring effective oil film formation across the entire contact surface regardless of rotational speed.
Solution Approach 2:
Oil is stored in advance within the concave portions (oil reservoirs) formed on the sliding contact surface. This preliminary storage of oil ensures that lubrication is available immediately upon contact, eliminating the delay in oil film formation that occurs at low speeds with dynamic pressure-only systems.
2Ease of operation
If the apex of the projected portion is disposed inward from the sliding contact surface, then oil flows over the projected portion at low-speed rotation, but the construction cannot contribute to decrease in torque and wear
Solution Approach 1:
The harmful projected portion that causes oil to ride over and flow to adjacent concave portions is removed. Instead, the sliding contact surface itself is recessed to form concave portions, directly extracting the problematic feature while preserving the beneficial oil distribution effect.
Solution Approach 2:
The sliding contact surface is given different local qualities through the formation of concave portions at specific locations. These recessed areas create zones of oil accumulation and reduced contact pressure, while the areas between concave portions maintain normal contact, optimizing both lubrication and load-bearing capabilities locally.
3Loss of energy
If concave portions are formed on the sliding contact surface, then torque generation is reduced, but sealing performance may be compromised
Solution Approach 1:
The concave portions are designed with asymmetric dimensions where the circumferential width is smaller than the radial depth. This asymmetric geometry allows the concave portions to effectively reduce contact area and torque while the deeper radial extension maintains sufficient contact pressure for sealing, creating an optimal balance between friction reduction and sealing effectiveness.
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 a balance of low oil leak and low torque generation performance across various rotational speeds, with improved oil flow and reduced wear, and can withstand high temperatures and increased diameter due to its material properties.
Implementation Method 1
allows hydraulic oil to flow easily to the sliding contact surface
Implementation Method 2
flow direction from the inner diameter side toward the outer diameter side
Implementation Method 3
generate a dynamic pressure so that the surface pressure is decreased
Implementation Method 4
forming an oil film on the sliding contact surface
Data Source
Figure 1(a)~1(b)
Figure 2
Figure 3
AI summary
It is an object of the present invention to provide a seal ring which has small oil leak and low torque generation performance for improving fuel consumption in a favorable balance as originally intended by the present invention. 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, 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. V-shaped concave portions (3) which do not contact the side wall surface of the annular groove are formed on at least one portion of an end of an inner diameter side of a side surface (2) of the seal ring (1) serving as a sliding contact surface which contacts the side wall surface of the annular groove along a circumferential direction of the seal ring (1).