Sliding Component With Segmented Pressure Grooves
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional sliding components face challenges in achieving both sealing and lubrication without leakage, especially during rotation and the start of rotation, as existing techniques either prioritize sealing over lubrication, leading to increased friction or prioritize lubrication, resulting in leakage.
Innovation Solution
The implementation of a sliding component with a positive pressure generating mechanism on the high-pressure side and a negative pressure generating mechanism on the low-pressure side, utilizing Rayleigh step mechanisms and reverse Rayleigh step mechanisms to create a pumping action that reduces leakage by ensuring fluid lubrication and maintaining a negative pressure gradient, thereby preventing fluid leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If fluid lubrication is promoted to reduce friction, then dynamic pressure is generated and a liquid membrane is formed, but the leakage rate increases due to increased pressure gradient and gap height
Solution Approach 1:
The sliding surface is segmented into multiple regions with different gap heights, creating a stepped structure. This segmentation allows different zones to serve different functions: some zones generate dynamic pressure for lubrication while others control leakage, resolving the contradiction between reducing friction and preventing leakage.
Solution Approach 2:
Different regions of the sliding surface are given different local properties through the stepped gap structure. High-pressure regions have smaller gaps to prevent leakage, while low-pressure regions have larger gaps to maintain lubrication, allowing each region to optimize its function locally.
2Reliability
If the liquid membrane thickness is increased to protect sliding surfaces from contact damage, then surface protection is improved, but the leakage rate increases
Solution Approach 1:
The protective function is segmented from the leakage control function through the stepped structure. Thinner membrane regions provide leakage control while thicker membrane regions provide surface protection, allowing both functions to be achieved simultaneously in different zones.
Solution Approach 2:
The problem is solved by adding a radial dimension to the gap height variation. Instead of uniform thickness in one direction, the gap height varies radially, creating a three-dimensional stepped structure that independently addresses protection and leakage control.
3Loss of substance
If the gap height is reduced to decrease leakage rate, then sealing performance is improved, but dynamic pressure effect is reduced and surface abrasion risk increases
Solution Approach 1:
The sealing function is segmented from the lubrication function. Small gap regions provide sealing and prevent leakage, while large gap regions maintain dynamic pressure for lubrication and surface protection, with both functions coexisting in the same sliding surface.
4Loss of substance
If a pumping mechanism with an initial gap is provided to draw leaked liquid back, then leakage is reduced, but the structure becomes complicated and leakage occurs when no motion is occurring
Solution Approach 1:
The pumping function is extracted from a separate mechanical pumping structure and is instead achieved passively through the stepped gap geometry itself. The pressure gradient naturally created by the stepped structure performs the pumping action without requiring additional complex mechanisms.
Solution Approach 2:
The stepped gap structure serves multiple functions automatically: it generates dynamic pressure for lubrication, controls leakage through pressure gradients, and performs pumping action to return leaked fluid, all without external control or additional mechanisms.
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 solution effectively reduces leakage rates, maintains low frictional coefficients, and allows for efficient fluid lubrication, even at high pressures and speeds, by ensuring no leakage occurs during motion or at the start of rotation, while allowing for easier machining and reduced centrifugal effects on the lubricating fluid.
Implementation Method 1
utilizing Rayleigh step mechanisms and reverse Rayleigh step mechanisms to create a pumping action
Implementation Method 2
dynamic pressure is generated by rotation between sliding surfaces
Implementation Method 3
creating a so-called fluid lubrication state, in which dynamic pressure is generated by rotation between sliding surfaces and sliding occurs in the presence of a liquid membrane
Data Source
Figure 1(a)~1(b)
Figure 2(a)~2(b)
Figure 3(a)~3(f)
AI summary
[Object] To provide a sliding component in which there is no leakage when no motion is occurring, action takes place with fluid lubrication and leakage is prevented during rotation including the start of rotation, and both sealing and lubrication can be achieved. [Means of Achievement] A positive pressure generating mechanism comprising a positive pressure generating groove (3) is provided to a high-pressure side of one of two sliding surfaces (2) that slide relative to each other in a pair of sliding components, and a negative pressure generating mechanism comprising a negative pressure generating groove (4) is provided to a low-pressure side, said positive pressure generating groove and negative pressure generating groove being communicated with a high-pressure fluid side and separated from a low-pressure fluid side by a seal surface (8).