Axial Spring Seal Pump Outlet for Tolerance-Resistant Sealing
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Solution Overview
Problem
Existing pump sealing technologies face challenges in maintaining a reliable and cost-effective seal, particularly in compensating for component and installation tolerances, thermally induced changes, and pressure-related movements, often requiring high surface pressures and being prone to gap extrusion and increased costs.
Innovation Solution
A pump design utilizing a spring seal, such as a disc spring or annular hollow profile spring, that completely surrounds the outlet and is axially tensioned to maintain a consistent sealing contact, potentially replacing traditional elastomer seals and eliminating the need for radial seals, while being less sensitive to mechanical and thermal loads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If soft material seals or elastomer seals are used as axial seals, then the sealing effect can be achieved through material elasticity, but the seals require high surface pressures and are prone to gap extrusion under pulsations and high pressures
Solution Approach 1:
The patent changes the material parameter from soft elastomer to hard metal spring material, fundamentally altering the sealing mechanism from elasticity-based to spring force-based. This parameter change eliminates gap extrusion risk while maintaining sealing effectiveness under high pressure and pulsations.
Solution Approach 2:
The spring seal uses simple metal spring material that is inexpensive and durable, replacing expensive elastomer materials that degrade over time. The metal spring provides long-term reliability without the aging issues of elastomers.
2Reliability
If soft material seals are used to compensate for component and installation tolerances and thermally induced changes, then sealing can be maintained, but the cost pressure increases and the seals require high surface pressures
Solution Approach 1:
Changing from elastomer to metal spring material eliminates the need for high surface pressures and complex tolerance control. The spring seal's mechanical compliance naturally accommodates tolerances and thermal expansion without requiring expensive precision manufacturing or high-pressure sealing surfaces.
Solution Approach 2:
The metal spring seal is simpler and less expensive to manufacture than elastomer seals, eliminating the need for specialized sealing surfaces and reducing overall manufacturing costs while maintaining consistent sealing performance.
3Reliability
If axial seals are used to separate outlets from the low-pressure side, then the sealing function is provided, but the axial width of the joint changes due to thermal and pressure effects, varying tolerances make reliable sealing difficult
Solution Approach 1:
The spring seal is designed to be dynamically compliant, automatically adjusting its compression to maintain sealing contact despite changes in joint width due to thermal expansion, pressure effects, or manufacturing tolerances. This dynamic adaptation eliminates the need for precise static tolerance control.
Solution Approach 2:
The patent changes the sealing approach from rigid elastomer deformation to flexible spring compression, allowing the seal to adapt to varying joint widths while maintaining consistent sealing pressure regardless of thermal or pressure-induced dimensional changes.
4Reliability
If traditional elastomer seals are used, then sealing can be achieved, but the seals are sensitive to mechanical and thermal loads and require consistent high surface pressures
Solution Approach 1:
The patent changes the material parameter from temperature-sensitive elastomer to thermally stable metal spring material. The spring seal maintains consistent mechanical properties across a wide temperature range and is insensitive to thermal aging, eliminating the stability issues of elastomer seals.
Solution Approach 2:
The metal spring seal provides long-term stability without the degradation, hardening, or cracking that plagues elastomer seals under mechanical and thermal loads, offering a durable alternative that maintains sealing performance throughout the pump's operational life.
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 spring seal effectively compensates for geometric and pressure-induced changes, ensuring a reliable seal over time with reduced material costs and improved stability, even under pulsations and varying pressures.
Implementation Method 1
The axial seal is a spring seal in the form of a disc spring or hollow profile spring or V-profile spring or bellows spring
Implementation Method 2
In the assembled state of the pump, the spring seal presses with spring force axially against the outer housing end face
Data Source
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AI summary
Pump for supplying fluid to a unit, for example a gearbox, wherein the pump comprises: (a) a pump housing (1) with - a housing circumferential wall (2) surrounding a pumping chamber (5), - a housing end wall (3) with an outer housing end face (14) facing axially away from the pumping chamber (5), - an inlet (6) for the fluid and - an outlet (8) for the fluid opening onto the outer housing end face (14), (b) a conveying element (10, 11) movable in the pumping chamber (5) for conveying the fluid from a low-pressure side of the pump comprising the inlet (6) to a high-pressure side of the pump comprising the outlet (8), and (c) an axial seal completely surrounding the outlet (8) for separation from the low-pressure side in axial view of the housing end wall (3), (d) wherein the axial seal is a spring seal (15; 15a; 15b; 15c; 41) in the form of a disc spring or hollow profile spring or V-profile spring or bellows spring.