Sliding Seal Deep-Groove Layout for Low-Pressure Fluid Film Stability
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Solution Overview
Problem
Conventional sliding components with Rayleigh step mechanisms for fluid pressure generation and leakage prevention suffer from fluid film depletion on the low-pressure side, leading to wear and friction heating issues, which compromise their sealing and lubrication performance.
Innovation Solution
A sliding component design featuring deep grooves on the opposite-to-sealed-fluid side, communicating with the sealed fluid side, to actively introduce fluid across the entire sliding face, utilizing positive and negative pressure generation mechanisms arranged efficiently with Rayleigh step grooves and reversed Rayleigh step grooves, and radially spaced circumferential grooves to prevent leakage and enhance lubrication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pressure release grooves are provided between positive and negative pressure generation grooves with the negative pressure grooves on the low-pressure side, then leakage prevention is improved, but fluid film depletion occurs on the low-pressure side causing wear and friction heating
Solution Approach 1:
The patent inverts the conventional arrangement by placing negative pressure generation grooves on the high-pressure fluid side and positive pressure generation grooves on the low-pressure fluid side. This reversal allows the negative pressure grooves to capture high-pressure fluid and prevent it from leaking to the low-pressure side, while the positive pressure grooves ensure adequate fluid film formation on the low-pressure side, thereby resolving the contradiction between leakage prevention and fluid film maintenance
Solution Approach 2:
The patent applies different groove types at different locations: negative pressure generation grooves (Rayleigh step mechanisms) are positioned on the high-pressure side to capture and contain high-pressure fluid, while positive pressure generation grooves are positioned on the low-pressure side to maintain fluid film pressure and prevent depletion. This localized differentiation of groove functions resolves the contradiction by addressing the specific fluid dynamics requirements of each pressure zone
2Ease of manufacture
If conventional Rayleigh step mechanisms are used with grooves of similar depth, then manufacturing is simplified, but fluid cannot be effectively introduced to the low-pressure side causing liquid film depletion
Solution Approach 1:
The patent specifies different groove depths for different functional zones: negative pressure generation grooves on the high-pressure side have a first depth optimized for capturing high-pressure fluid, while positive pressure generation grooves on the low-pressure side have a second depth optimized for maintaining fluid film pressure. This localized differentiation of groove depth ensures optimal fluid introduction and film formation while maintaining manufacturing feasibility through standardized machining processes
Solution Approach 2:
The patent changes the depth parameter of grooves based on their functional location and pressure side. By optimizing the depth of negative pressure grooves on the high-pressure side and positive pressure grooves on the low-pressure side, the patent enables effective fluid introduction across the sliding interface while maintaining reliable fluid lubrication, resolving the contradiction between manufacturing simplicity and functional reliability
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 maintains sealing function, reduces wear and torque, and prevents fluid film depletion, ensuring long-term performance by actively taking fluid into the sliding faces and managing pressure effectively.
Implementation Method 1
grooves 35 of Rayleigh step mechanisms 33 constituting positive pressure generation mechanisms
Implementation Method 2
grooves 36 of reversed Rayleigh step mechanisms 34 constituting negative pressure generation mechanisms
Implementation Method 3
operates with fluid lubrication while preventing leakage during rotation including the early stages of rotation
Data Source
AI summary
A sliding component is provided. At least one sliding face of sliding faces sliding relatively to each other of a pair of sliding parts of annular shapes is provided with positive pressure generation mechanisms with positive pressure generation grooves and negative pressure generation mechanisms with negative pressure generation grooves. The positive pressure generation grooves and the negative pressure generation grooves are separated from the opposite-to-sealed-fluid side by a land. Deep grooves deeper than the groove depth of the positive pressure generation grooves and the negative pressure generation grooves are located at least on the opposite-to-sealed-fluid side of the positive pressure generation grooves and the negative pressure generation grooves. The deep grooves are provided in such a manner as to communicate at least with the sealed fluid side.