Stator Coil Joint Positioning for Radial Size Reduction
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Solution Overview
Problem
Conventional stator designs for electric rotating machines require long electric wires, leading to difficulties in handling and manufacturing, which results in low productivity and high costs due to the need for large-scale shaping machines.
Innovation Solution
A stator coil configuration using multiple electric wires with end portions joined together to form a joint that does not radially protrude from the coil end, allowing for a minimized radial size and overall size reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If long electric wires are used to form phase windings, then the stator coil can be manufactured with conventional methods, but the productivity decreases and manufacturing cost increases due to the need for large-scale shaping machines and difficult handling
Solution Approach 1:
The patent divides the phase windings into multiple separate electric wires (first electric wire, second electric wire, third electric wire) instead of using single long wires. Each wire has a length suitable for conventional shaping machines, and they are connected in parallel to form the complete phase windings. This segmentation resolves the contradiction by enabling easier handling and manufacturing with standard equipment while maintaining the required electrical functionality.
2Ease of manufacture
If long electric wires are used, then the phase windings can be formed, but the radial size of the stator coil increases due to protruding joints
Solution Approach 1:
The patent positions the joints connecting the multiple electric wires in the axial direction rather than allowing them to protrude radially. The joints are located within the axial extent of the coil end, so they extend in the axial dimension without increasing the radial dimension. This dimensional repositioning resolves the contradiction by accommodating the necessary connections without increasing the radial size of the stator coil.
3Device complexity
If single long electric wires are used for each phase winding, then the electrical connection is simplified, but the device complexity increases due to the need for large-scale shaping machines
Solution Approach 1:
The patent segments each phase winding into multiple shorter electric wires that can be processed by conventional shaping machines. The first, second, and third electric wires are each shaped independently using standard equipment, then connected in parallel to form the complete phase windings. This segmentation resolves the contradiction by eliminating the need for large-scale shaping machines while maintaining manufacturability through multiple simpler components.
Data Source
AI summary
A stator for an electric rotating machine includes a hollow cylindrical stator core and a multi-phase stator coil comprised of a plurality of electric wires mounted on the stator core. The stator coil includes a plurality of phase windings each of which is formed of at least two electric wires. One of the two electric wires has an end portion led out from the radially inner periphery of one slot of the stator core while the other electric wire has an end portion led out from the radially outer periphery of another slot of the stator core. The end portions of the two electric wires are joined together to form a joint therebetween. The joint is positioned axially outward of a coil end part of the stator coil, which protrudes from an axial end face of the stator core, without radially protruding from the coil end part.