Mechanical Seal Ring Projection Packing Design
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Solution Overview
Problem
Existing mechanical seals for handling slurries or fluids face challenges in maintaining a stable seal without leakage, especially when fluid pressure fluctuates, as they often rely on springs that can be affected by slurry adherence and varying friction coefficients.
Innovation Solution
A mechanical seal design featuring a ring-shaped projection on the seal case that pushes against the packing to maintain contact with the stationary-side sealing ring, eliminating the need for a spring and ensuring a stable seal across varying pressure conditions, with options for metal or rubbery elastic materials and configurations that reduce component count and production costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a spring is used to push the stationary-side sealing ring toward the sliding surface, then the sealing function is maintained under normal conditions, but the spring becomes affected by slurry adherence and varying friction coefficients, causing unreliable sealing under fluctuating pressure
Solution Approach 1:
The invention removes the spring component from the mechanical seal system and replaces it with a packing element that is directly pushed by fluid pressure. This extraction eliminates the harmful effect of slurry adherence to spring coils, which causes unreliable sealing when the spring fails to function properly under fluctuating pressure conditions.
Solution Approach 2:
The packing element is designed to be self-actuating through fluid pressure. The slurry or fluid pressure directly pushes the packing against the stationary-side sealing ring, eliminating the need for an external spring mechanism. This self-service approach ensures consistent sealing force without being affected by slurry adherence issues that plague spring-based systems.
2Reliability
If the inner circumference of the packing is coated with grease to reduce friction, then the coefficient of friction is lowered and sealing is improved, but the packing deforms and the inner circumferential side attempts to withdraw, requiring precise control
Solution Approach 1:
The invention changes the friction parameter by providing a grooved structure on the inner circumference of the packing instead of coating with grease. The grooves allow slurry or fluid to pass through, creating a lubricating effect that reduces friction between the packing and stationary-side sealing ring without causing excessive deformation or withdrawal of the packing inner circumferential side.
3Reliability
If multiple components (spring, packing, seal rings) are used to ensure reliable sealing, then sealing function is achieved, but the device complexity and production cost increase
Solution Approach 1:
The invention merges the sealing and actuating functions into a single integrated packing element. The packing serves both as the sealing medium and as the component that is directly actuated by fluid pressure, eliminating the need for separate spring and packing components. This reduction in component count simplifies the device structure and reduces production costs while maintaining reliable sealing function.
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 achieves a consistent sealing force without leakage, even under fluctuating pressures, and reduces production costs by minimizing components, while maintaining seal integrity in both greased and ungreased conditions.
Implementation Method 1
the stationary-side sealing ring is pushed in the direction of the rotary-side sealing ring by a spring and by a packing made of a rubber material
Implementation Method 2
the ring-shaped projection provided to the first seal case supports the back surface of the ring-shaped packing, and serves to hinder any deformation of the packing beyond the gap
Implementation Method 3
the coefficient of friction between the inner circumference of the packing and the stationary-side sealing ring is lowered and the pressure of the machine-interior side acts on the machine-interior side of the packing
Data Source
AI summary
An inside-type mechanical seal is mounted between a rotating shaft and a housing, and adapted for preventing leakage of a sealed fluid from an outer circumference of a sliding surface in the direction of an inner circumference thereof, wherein provided are a rotary-side sealing ring mounted on a rotating shaft side, a stationary-side sealing ring mounted on a seal case side, an annular packing for pushing the stationary-side sealing ring toward the rotary-side sealing ring, a holding part on the outer circumferential side being fitted in the seal case, and a seal lip part on the inner circumferential side being in close contact with the stationary-side sealing ring, and wherein provided to the seal case is a ring-shaped projection abutting against a back surface of the packing during assembly of the mechanical seal, and adapted for pushing the packing toward the stationary-side sealing ring.