Water-Pump Motor With Outer Winding and Ferrite Magnets
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Solution Overview
Problem
Conventional water pump motors face inefficiencies due to inner rotor structures, complex coil winding methods, high production costs, and vulnerability to water corrosion, which necessitate the use of expensive Nd magnets and additional sealing measures.
Innovation Solution
A water pump motor design featuring a stator core with an outer winding method, a slot-less type, and an annular yoke, integrated waterproof bobbins, and ferrite magnets, allowing for reduced manufacturing costs and improved efficiency by minimizing air gaps and eliminating the need for separate sealing components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If an inner rotor structure with inner coil winding method is employed, then the motor structure is compact, but the coil winding becomes difficult and the fill factor cannot be increased
Solution Approach 1:
The patent inverts the conventional inner rotor structure to an outer rotor structure, where the rotor is positioned outside the stator. This inversion allows the coil winding to be performed externally on the rotor surface, significantly easing the manufacturing process while maintaining compact overall dimensions. The outer rotor configuration enables better access for winding operations and improves the fill factor of the motor.
2Reliability
If a can cover is added to protect the water pump motor, then waterproofing is improved, but the prime cost rises and productivity lowers
Solution Approach 1:
The patent merges the can cover function directly into the stator structure by making the stator itself waterproof. The stator is designed with a sealed construction that integrates the protective function previously requiring a separate can cover. This eliminates the need for additional assembly steps and reduces the number of components, thereby improving productivity while maintaining reliable waterproofing.
3Power
If Nd magnets are used to provide strong magnetic force, then the motor output is sufficient, but the production cost increases and corrosion resistance is poor
Solution Approach 1:
The patent replaces expensive Nd magnets with cheaper ferrite magnets. While ferrite magnets have lower magnetic strength, the outer rotor structure and optimized magnetic circuit design compensate for this, achieving sufficient motor output. This substitution significantly reduces material costs and improves corrosion resistance, as ferrite magnets are inherently more resistant to water corrosion compared to Nd magnets.
4Device complexity
If an inner winding method is used in the stator, then the structure is conventional, but the coil winding space is narrow and efficiency cannot be enhanced
Solution Approach 1:
The patent inverts the winding arrangement by moving the coil winding to the outer rotor structure. This outer winding configuration provides ample space for coil placement and winding operations, significantly increasing the fill factor and improving motor efficiency. The inverted structure eliminates the space constraints of inner winding while maintaining a conventional overall motor design.
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 enhances motor efficiency, reduces noise and vibration, and lowers production costs by using low-cost ferrite magnets and simplifying the manufacturing process while providing a robust waterproof structure.
Implementation Method 1
a water pump motor having a stator (70) and an inner type rotor (50) disposed inside the stator (70), wherein the stator (70) includes a stator core (71) whose inner circumferential portion is annularly interconnected to allow outer windings
Implementation Method 2
The rotor (50) includes a plurality of ferrite magnets (53) opposed to inner side surfaces of the bobbins (73)
Data Source
AI summary
Provided are a water pump motor that employs a stator core of an outer winding method that can use a low-cost ferrite magnet by minimizing an air gap between a magnet of a rotor and a stator core, and that heightens a fill factor, to thereby maximize efficiency of the motor, and a water pump using the water pump motor. The water pump motor includes a stator and an inner type rotor, in which the stator includes: a stator core whose inner circumferential portion is annularly interconnected, in which a number of protrusions are radially extended and formed; insulating bobbins that surround the stator core; a coil wound around the outer circumference of each bobbin; and an annular back yoke that surrounds in contact with the outer end of the stator core. The insulating bobbins are annularly molded to surround the inner circumferential portion of the stator core, and entirely surround the inner circumferential portion of the stator core, to thus make the inner side surface play a role of a sealing cover, and the rotor includes ferrite magnets in opposition to the inner side surfaces of the bobbins.