Pump Stator Seal Material Matching for Temperature-Stable T-Joints
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The complex geometry of T-joints in pump stators causes seals to distort with temperature changes, leading to inconsistent sealing across a range of operational temperatures, particularly in half shell stator pumps.
Innovation Solution
Selecting materials for seals with specific ranges of stiffness and hardness, typically between 74-80 Shore A hardness and 2.4-4.2 N/mm per mm length, ensures minimal stress mismatch and effective sealing across varying temperatures by maintaining consistent seal interface geometry.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional sealing materials are used in T-joints, then the seal can be installed, but the seal distorts with temperature changes causing unreliable sealing
Solution Approach 1:
The patent applies parameter changes by selecting sealing materials with specific stiffness and hardness parameters within defined ranges. This resolves the contradiction by ensuring the seal maintains its geometric stability across temperature changes while still providing effective sealing, thus improving reliability without being constrained by temperature variations.
2Reliability
If seal compression is increased to improve sealing, then sealing pressure improves, but seal distortion increases causing stress mismatch
Solution Approach 1:
The patent resolves this contradiction by changing the material parameters of stiffness and hardness to specific ranges. This allows the seal to maintain its shape and interface geometry even under compression, preventing stress mismatch between axial and annular seals while still providing effective sealing.
Solution Approach 2:
The patent applies the copying principle by using the same material with identical stiffness and hardness parameters for both axial and annular seals. This ensures that both seals experience matching stress changes and maintain consistent interface geometry, resolving the distortion and stress mismatch problems.
3Adaptability or versatility
If different materials are used for axial and annular seals, then each seal can be optimized for its specific function, but stress mismatch occurs affecting seal interface geometry
Solution Approach 1:
The patent applies homogeneity by using the same material with identical stiffness and hardness parameters for both axial and annular seals. This resolves the contradiction by ensuring that both seals experience matching stress changes and maintain consistent interface geometry, while still allowing each seal to perform its specific sealing function effectively.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A set of seals for sealing between the stator components of a pump, the stator components comprising two half shells defining at least one pumping chamber and two head plates to be mounted at either end of the two half shells. The set of seals comprises: at least one annular seal for sealing between at least one of the head plates and the two half shells; two longitudinal seals for sealing between longitudinal contact faces of the two half shell stators on either side of the at least one pumping chamber, the longitudinal seals being configured to have end portions that abut against the at least one annular seal when mounted in the pump. Each of the seals within the set of seals are made of a material having at least one of: a hardness between 73 – 83, preferably 75 - 81 on the Shore A hardness scale; and a stiffness of between 2.4 and 4.2 N/mm per mm length, wherein the stiffness is measured by axially compressing at room temperature an O-ring of the material, the O-ring having a cross section diameter of 3.4 mm and an internal diameter of at least 40 mm.