Stator Coil Terminal Positioning for Reduced Height
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Solution Overview
Problem
The existing stator design for rotary electric machines experiences distortion in the punched core member, leading to increased resistance to the magnetic field and motor output loss, resulting in a larger stator size and height due to the positioning of coil wires and connecting wires, which complicates welding and insulation.
Innovation Solution
The stator design positions the terminal ends of middle coils closer to the stator core, allowing for reduced height of the connecting portions and bus bar joints, with molded bus bar portions and terminal portions that are tilted and positioned under the connecting portions of adjacent coils, enhancing positional accuracy and insulation performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the coil wire is mounted on a punched core member that is split in circumferential direction, then the stator can be assembled with coils, but distortion occurs in the punched portion increasing resistance to magnetic field and motor output loss
Solution Approach 1:
The core member is divided into a first core member and a second core member that are coupled together. This segmentation allows each core member to be manufactured with fewer punches, reducing distortion in the punched portions while still enabling complete coil assembly. The coupling of segmented core members eliminates the need for extensive punching in a single piece, thereby reducing magnetic field resistance and energy loss.
2Ease of manufacture
If the joint part of coil wire and connecting wire is formed at high position to secure work space for welding, then welding operation can be performed, but the height of coil end is extremely increased increasing stator size
Solution Approach 1:
The connecting wire is configured to extend in the radial direction of the stator core rather than only in the axial direction. This dimensional change allows the connecting wire to reach the coil wire at a lower height position, providing adequate welding workspace without increasing the overall stator height. The radial extension creates a new spatial pathway for the connecting wire, resolving the conflict between welding accessibility and compact stator dimensions.
3Ease of operation
If the terminal portions of middle coils are positioned at higher height for easier connection, then connection can be made, but the height of coil end increases increasing stator size
Solution Approach 1:
The terminal portions of the middle coils are pre-positioned to extend in the radial direction toward the connecting portion of the first coil before final assembly. This preliminary positioning ensures that the terminal portions are already in proximity to the connection point, facilitating easy connection operations. The radial extension is prepared in advance, eliminating the need to raise the coil end height to achieve connection accessibility.
Data Source
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AI summary
In a stator, a bus bar portion includes a joint portion that is formed at an end of the bus bar portion and is joined to a terminal portion of a different one of the coils, and a connecting portion that is formed between the joint portion and a winding portion, and in the coils of each of three phases that are U-phase, V-phase, and W-phase, a first coil and a second coil that serve as the two coils joined to each other are joined to each other by the joint portion of the bus bar portion of the first coil and the terminal portion of the second coil, and ends of the terminal portions of middle coils that are the coils disposed between the first coil and the second coil are located at a height closer to a stator core than the connecting portion of the first coil in a direction of a central axis of the stator core.