Three-Phase Pump Motor Wire Routing for Aluminum Conductor Reliability
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Solution Overview
Problem
Existing electric motors in water-conducting appliances, such as dishwashers and washing machines, face challenges with high failure rates and inefficiencies when using aluminum wires due to insulation defects and thermal management issues, which are exacerbated by the material characteristics of aluminum compared to copper wires.
Innovation Solution
The design incorporates a ferrite body with lateral-circumferential magnetization and a pole chain made from stacked transformer sheets, allowing for spatial separation of wires and use of support pins to maintain wire position during the winding process, enabling the use of aluminum or copper wires without increasing motor size and reducing failure rates by preventing short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If aluminum wires are used instead of copper wires, then cost efficiency is improved, but reliability deteriorates due to insulation defects and short circuits
Solution Approach 1:
The patent routes wires in spatially separated three-dimensional paths through the stator, with wires of different phases positioned at different axial levels and radial distances. This dimensional separation prevents contact between wires, eliminating the reliability issue of aluminum wire insulation defects while maintaining cost efficiency.
Solution Approach 2:
The patent introduces an intermediary insulation coating on the wires and uses the spatial arrangement of winding cores as a mediator to prevent direct contact between wires. This intermediary protection system allows the use of aluminum wires without suffering from their inherent insulation vulnerability.
2Reliability
If wire routing space is increased to prevent short circuits, then reliability is improved, but device complexity increases
Solution Approach 1:
The patent utilizes three-dimensional space within the stator structure, routing wires at different axial levels and radial distances. This spatial arrangement provides adequate separation for reliability without requiring additional complex insulation structures or increasing overall device complexity.
Solution Approach 2:
The patent divides the wire routing into distinct segments corresponding to different phases (U, V, W), with each phase having its own dedicated path through the stator. This segmentation simplifies the routing process by treating each phase independently, reducing overall complexity while ensuring reliability through separation.
3Ease of manufacture
If aluminum wires are used, then cost efficiency is improved, but thermal management deteriorates due to lower thermal conductivity
Solution Approach 1:
The patent increases the surface area for heat dissipation by routing wires through extended three-dimensional paths within the stator. This extended path length and increased exposure to cooling fluid compensate for aluminum's lower thermal conductivity, maintaining effective heat dissipation while using cost-effective aluminum wires.
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
This solution enhances the reliability and efficiency of electric motors by allowing the use of aluminum wires with reduced failure rates and improved thermal management, maintaining performance comparable to copper wire motors without enlarging the motor components.
Implementation Method 1
a rotor comprising a ferrite body with at least four magnetic poles, wherein the ferrite body has a lateral-circumferential magnetization
Implementation Method 2
an electric motor comprising: a rotor comprising a ferrite body with at least four magnetic poles... a stator comprising: a pole chain... and a plurality of winding cores attached to the respective pole teeth for accommodating coils of a three-phase winding
Data Source
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AI summary
A pump for a water-conducting appliance, the pump having an electric motor comprising: a rotor comprising a ferrite body with at least four magnetic poles, wherein the ferrite body has a lateral-circumferential magnetization; and a stator comprising a pole chain made of a stack of a plurality of straight transformer sheets and rounded to a circular configuration by bending the stacked transformer sheets, wherein the pole chain has a plurality of pole portions each comprising a pole tooth; and a plurality of winding cores attached to the respective pole teeth for accommodating coils of a three-phase winding comprising wires; wherein the wires of respective phases of the three-phase winding are routed spatially separated from each other and without mutual contact at an axial end surface of the pole chain between and along adjacent winding cores around the pole chain; and wherein the wires are supported and guided such that their positions relative to the pole chain are substantially maintained when the pole chain is rounded from its straight configuration to its circular configuration.