Motor Coil-End Insulation Ring With Refrigerant Injection
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Solution Overview
Problem
Reducing the size of motors while ensuring effective insulation between the coil end and the housing is challenging, especially when the coil end is close to the inner surface, leading to potential electric discharges and increased costs due to larger housing sizes.
Innovation Solution
An insulative annular member with a cylindrical portion and a radially protruding portion is used between the coil end and the housing inner wall, featuring injection holes for refrigerant to enhance cooling and insulation, preventing electrical discharges and allowing for a reduced motor size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the coil end is located close to the inner surface of the housing to reduce motor size, then the motor size is reduced, but insulation between the coil end and housing becomes difficult to ensure
Solution Approach 1:
An insulative annular member is introduced as an intermediary component between the coil end and the housing inner surface. This annular member includes a cylindrical portion that contacts the housing and a radially protruding portion that contacts the coil end, providing reliable insulation even when the coil end is positioned close to the housing to reduce motor size.
Solution Approach 2:
The insulative annular member extends in the radial direction with a protruding portion that reaches toward the coil end, adding a dimensional element that provides insulation without increasing the axial length of the motor, thus maintaining compact size while ensuring insulation.
2Volume of moving object
If the coil end is located close to the inner surface of the housing, then motor size is reduced, but the risk of electrical discharges increases
Solution Approach 1:
The insulative annular member serves as a mediator that physically separates the conductive coil end from the housing, preventing electrical discharge paths while allowing the coil end to be positioned close to the housing for compact motor design.
3Device complexity
If a single annular member provides both sealing and insulation functions, then device complexity is reduced, but the ability to provide both cooling and insulation simultaneously is limited
Solution Approach 1:
The insulative annular member is designed to perform multiple functions simultaneously: it provides electrical insulation between the coil end and housing, maintains sealing between the stator core and housing, and serves as a conduit for refrigerant injection through its first portion to cool the coil end, thereby combining insulation, sealing, and cooling functions in a single component.
Solution Approach 2:
The sealing function and insulation function are merged into a single insulative annular member, eliminating the need for separate sealing and insulating components, while the integrated structure also incorporates cooling capability through refrigerant injection holes.
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 solution effectively enhances insulation and cooling efficiency, allowing for a smaller motor size without increasing the risk of electrical discharges, even when segment coils' ends are exposed, and reduces the motor's overall dimensions.
Implementation Method 1
a plurality of first holes through which refrigerant is injected toward the first coil end
Data Source
AI summary
A motor may include: a stator comprising a stator core and a coil; a housing that houses the stator; and a first annular member that provides a seal between a first end face of the stator core and an inner wall surface of the housing. The inner wall surface may include a first inner wall surface radially facing a first coil end of the coil and a second inner wall surface facing the first coil end. The first annular member may include: a first portion having a cylindrical shape and interposed between the first coil end and the first inner wall surface; and a second portion protruding radially inward from the first portion and interposed between the first coil end and the second inner wall surface. The first portion may include a plurality of first holes through which refrigerant is injected toward the first coil end.