Liquid Pump Shaft Seal Relocation and Elastic Cover Design
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Solution Overview
Problem
Existing liquid pumps suffer from reduced operational life and efficiency due to wear and tear on sealing components and high fluid pressure, leading to leakage and decreased performance.
Innovation Solution
A liquid pump design with a shaft seal adjacent to an inlet chamber, where the fluid pressure is lower than the pump chamber, and an elastic member between inner and outer covers to balance fluid pressure, maintaining sliding contact and preventing gap formation between gears.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the shaft seal is positioned in the pump chamber exposed to high fluid pressure, then sealing effectiveness is maintained, but wear and tear increases and operational life decreases
Solution Approach 1:
The pump chamber is divided into a high-pressure zone (pump chamber) and a low-pressure zone (inlet chamber). The shaft seal is relocated to the inlet chamber where fluid pressure is lower, segmenting the sealing function from the high-pressure pumping zone. This reduces wear on the shaft seal while maintaining sealing effectiveness in both zones through separate sealing arrangements.
Solution Approach 2:
The inner cover acts as an intermediary component between the high-pressure pump chamber and the low-pressure inlet chamber. It features an axial surface that maintains sliding contact with the gears while being pressed by an elastic member, mediating the pressure differential and protecting the shaft seal from direct exposure to high pressure.
2Productivity
If the inner cover maintains sliding contact with gear axial surfaces to prevent gaps, then pump efficiency is maintained, but wear and tear on the inner cover increases
Solution Approach 1:
The inner cover is designed with a specific axial surface that locally contacts the gear surfaces. This localized contact area is optimized for maintaining sliding contact to prevent gaps between the inner cover and gears, while the elastic member provides localized pressure only where needed to maintain this contact without subjecting the entire inner cover to excessive stress.
Solution Approach 2:
The elastic member positioned between the inner and outer covers provides beforehand cushioning by exerting a pressing force on the inner cover's axial surface. This pre-applied force ensures continuous sliding contact with the gear axial surfaces, compensating for wear and maintaining gap-free contact throughout operation, thereby extending the inner cover's operational life.
3Productivity
If high fluid pressure is used to drive the pump mechanisms, then pumping performance is improved, but gap formation between inner cover and gears increases
Solution Approach 1:
The elastic member exerts a counteracting force on the inner cover's axial surface that opposes the force generated by high fluid pressure. This counterforce prevents the high pressure from pushing the inner cover away from the gear axial surfaces, maintaining stable sliding contact and preventing gap formation even during high-performance pumping operations.
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 design extends the operational life of the shaft seal and pump components by reducing wear and tear, while maintaining efficient fluid transfer and performance.
Implementation Method 1
An elastic member is disposed between the inner cover and outer cover, and configured to exert a pressure on the inner cover such that a surface of the inner cover maintains sliding contact with the axial surface of the pump mechanisms
Data Source
AI summary
A liquid pump includes a pump assembly attached to a motor. The pump assembly includes an inlet chamber and pump chamber. The pump chamber accommodates a drive gear driven by an output shaft of the motor and driven gear meshed with the drive gear. An inner cover is disposed within the pump chamber. An outer cover overlies the inner cover with an elastic member disposed there between. The outer cover exerts a force to the inner cover through the elastic member and holds the inner cover in sliding contact with an axial end of the drive and driven gears. An outlet chamber formed between the inner cover and the outer cover is in fluid communication with and the pump chamber.