Stator Winding Axial Height Reduction via Radial Terminal Distribution
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Solution Overview
Problem
Existing stator designs for rotary electric machines, such as those in electric vehicles, face increased axial dimensions due to the placement of connecting units outside coil ends, which also damage insulating coatings and require larger bending radii, further increasing machine height.
Innovation Solution
A stator design with distributed winding bodies mounted circumferentially at a pitch of one slot, featuring small coil groups connected within a circular arc-shaped region, where crossover portions are bent radially outward and joined to conductor terminals, reducing axial height and minimizing damage to insulating coatings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If connecting units are disposed axially outside the crossover portions to make them compact, then the connecting units can be housed compactly, but the axial height positions of the connecting units from the coil ends become high, increasing axial dimensions of the rotary electric machine
Solution Approach 1:
The invention transitions the connection arrangement from a vertical stacking approach (axial direction) to a radial distribution approach. By disposing conductor terminals radially around the stator core and connecting them within the radial plane rather than stacking them axially, the solution moves the connection problem into a different dimensional space (radial dimension), thereby reducing axial height while maintaining connection functionality.
2Reliability
If the bending radius is made large to suppress damage to insulating coatings, then insulation performance is maintained, but distances between crossover portions and coil ends increase, raising axial height positions of connecting units and further increasing axial dimensions
Solution Approach 1:
The invention extracts the connection function from the axial space outside coil ends and relocates it to the radial plane within the stator core. By taking out the crossover portions from the axial arrangement and redistributing them radially around the stator core, the solution eliminates the need for large bending radii in the axial direction while maintaining insulation integrity through proper radial positioning.
3Power
If busbars with large cross-sectional areas are used to pass large currents through the stator winding, then sufficient current carrying capacity is achieved, but the connecting units increase in size and lead to interference with peripheral parts of the electric motor
Solution Approach 1:
The invention redistributes the current carrying function from a vertical axial arrangement to a radial distribution around the stator core. By arranging conductor terminals radially and connecting them in the radial plane, the solution maintains sufficient current carrying capacity through proper conductor sizing while reducing axial projection and minimizing interference with peripheral motor parts.
Data Source
AI summary
Small coil groups are each configured by connecting a plurality of winding bodies in series by passing crossover portions that are formed by bending first conductor terminals radially outward axially outside a coil end and joining the crossover portions to second conductor terminals that are subject to joining, the first conductor terminals that constitute first ends of the small coil group are disposed so as to be spaced apart from each other circumferentially around a radially inner side of a circular arc-shaped region that extends circumferentially around the coil end, the second conductor terminals that constitute second ends of the small coil group are arranged so as to be spaced apart from each other circumferentially around a radially outer side of the circular arc-shaped region of the coil end, and a stator winding is produced by connecting the small coil groups within the circular arc-shaped region.