Waterproof Fluid Pump Using Magnetic Torque Coupling
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Solution Overview
Problem
Conventional water pump motors face issues with waterproofing, efficiency, and manufacturing costs due to the soaking of the rotor in water, adverse effects on bearing durability, and complex assembly processes, along with increased costs from double sealing structures and compatibility issues with stator cores.
Innovation Solution
A waterproof fluid pump design featuring a motor with a stator and rotor separated from the impeller, using magnetic forces to transfer torque, with a support shaft and magnets to prevent water ingress, eliminating the need for additional sealing devices and optimizing the magnetic gap between the rotor and stator.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a canned cover structure is used to seal the stator, then waterproof performance is improved, but the rotor soaks in water causing bearing durability to deteriorate and motor efficiency to decrease
Solution Approach 1:
The pump is divided into two separate assemblies: a motor assembly containing the stator and rotor, and a pump assembly containing the impeller and pump housing. The motor assembly is sealed within a motor case that prevents water ingress, while the pump assembly handles the fluid. This segmentation allows the motor to remain waterproof without requiring the rotor to be isolated from water by a canned cover, thus preserving bearing durability.
Solution Approach 2:
A magnetic coupling mechanism acts as an intermediary to transfer rotational force from the rotor to the impeller without direct mechanical connection. The rotor generates a magnetic field that induces rotation in the impeller through magnetic attraction and repulsion forces. This eliminates the need for a mechanical seal or canned cover between the motor and pump sections, allowing the motor to be sealed while the impeller remains in contact with fluid.
2Reliability
If a canned cover is placed between the rotor and stator, then waterproof performance is improved, but the magnetic gap cannot be maintained optimally causing motor efficiency to decrease
Solution Approach 1:
The motor assembly is completely separated from the pump assembly, with the rotor and stator both housed within the sealed motor case. This eliminates the need for a canned cover between the rotor and stator, allowing the magnetic gap to be precisely controlled during manufacturing for optimal motor efficiency while maintaining waterproof performance through the motor case seal.
3Device complexity
If the axis of rotation of the impeller is integrally formed with the axis of rotation of the motor, then assembly is simplified, but the motor assembly and pump assembly cannot be independently assembled and tested causing assembly productivity to decrease
Solution Approach 1:
The pump is divided into separate motor assembly and pump assembly that can be manufactured and tested independently. The motor assembly includes the motor case, stator, rotor, and magnetic coupling mechanism, while the pump assembly includes the pump housing, impeller, and fluid inlet/outlet. This segmentation enables parallel manufacturing and quality control, improving overall assembly productivity despite the added complexity of coupling the two assemblies.
Solution Approach 2:
The magnetic coupling mechanism serves as an intermediary that enables independent assembly of the motor and pump sections. The rotor and impeller are positioned on separate support shafts that are coupled through magnetic interaction rather than direct mechanical connection, allowing each assembly to be completed and tested separately before final integration.
4Reliability
If a double sealing structure is used on the outside of the stator, then waterproof performance is improved, but manufacturing cost increases
Solution Approach 1:
The motor assembly is enclosed in a sealed motor case that acts as a single comprehensive barrier against water ingress. This eliminates the need for multiple sealing layers on the stator, as the motor case provides complete waterproof protection for all motor components including the stator, rotor, and magnetic coupling mechanism. The single-seal approach reduces manufacturing complexity and cost while maintaining equivalent or superior waterproof performance.
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 effectively prevents water from entering the motor, enhances motor efficiency, and reduces manufacturing costs by using oil-filled bearings and simplifying assembly, while maintaining optimal magnetic gap settings.
Implementation Method 1
a first magnet that is fixed to the rotor and is rotated with the rotor; and a second magnet that is fixed to the impeller and is disposed facing the first magnet and that has opposite polarity to that of the first magnet
Data Source
AI summary
Provided is a waterproof fluid pump including: a motor that is accommodated in a first case and comprises a stator and a rotor, to thus generate a rotating torque; an impeller that is accommodated in a pump housing that is mounted in the first case and that receives the rotating torque of the motor to thus pump fluid; a support shaft to which the rotor and the impeller are rotatably supported and that is fixed to the first case; a first magnet that is fixed to the rotor and is rotated with the rotor; and a second magnet that is fixed to the impeller and is disposed facing the first magnet and that has opposite polarity to that of the first magnet. Thus, fluid may be fundamentally prevented from being introduced into the inside of the motor.