Rotary Electric Machine Unit Winding Shift for Torque Ripple
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Solution Overview
Problem
Existing rotary electric machine units in hybrid vehicles face challenges in optimizing fuel consumption and performance due to the similar cross-sectional shapes of drive motors and power generators, which affect torque direction and efficiency.
Innovation Solution
A rotary electric machine unit comprising a drive motor and a power generator, each with a stator core having slots for distributed winding, where the inner and outer peripheral winding sections share slots and are shifted by at least one slot, with the shift direction of the drive motor's stator coils opposite to its torque direction and the power generator's stator coils aligned with its torque direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the drive motor and power generator have the same cross-sectional shape with distributed windings, then manufacturing efficiency and component standardization are improved, but torque ripple and performance optimization are worsened
Solution Approach 1:
The patent applies local quality by differentiating the winding configurations between the drive motor and power generator while maintaining the same stator core structure. Specifically, the drive motor uses a winding pattern where coils are distributed across multiple slots with specific pitch relationships, while the power generator uses a different winding distribution pattern. This allows each component to be optimized for its specific function (motor vs generator) while sharing the same manufacturing process and stator structure, thus resolving the contradiction between manufacturing efficiency and torque ripple performance
2Volume of moving object
If the stator coils are configured with outer and inner peripheral windings sharing slots, then space utilization and compactness are improved, but manufacturing complexity and winding precision are worsened
Solution Approach 1:
The patent segments the windings into outer peripheral windings and inner peripheral windings that share the same slots. Each winding type is placed in specific regions of the slots (outer vs inner periphery), allowing for systematic arrangement and reduced manufacturing complexity. The segmentation approach enables standardized winding processes while achieving high space utilization through efficient slot filling
Solution Approach 2:
The patent implements a nested winding structure where inner peripheral windings are positioned within the same slots as outer peripheral windings, effectively nesting one winding type inside another. This nesting approach maximizes space utilization by fully utilizing the slot volume while maintaining organized, manufacturable winding patterns that reduce precision requirements compared to completely independent winding placements
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 configuration improves acceleration performance of the drive motor and reduces torque ripple in the power generator, allowing for enhanced performance and efficiency while maintaining the same cross-sectional shape for both components.
Implementation Method 1
a rotary electric machine unit includes two rotary electric machines, which are a drive motor and a power generator
Data Source
AI summary
A rotary electric machine apparatus includes a drive motor and a power generator. The drive motor and the power generator each include a stator. The stator includes a stator core and stator coils. The stator core has a plurality of slots which extend through the stator in an axis direction of the stator and which are disposed in a circumferential direction of the stator with a predetermined interval. The stator coils for a plurality of phases are each disposed in the plurality of slots as a distributed winding. The drive motor is provided such that a shift direction of the stator coils and a torque direction of the drive motor are opposite to each other. The power generator is provided such that the shift direction of the stator coils and a torque direction of the power generator are a same as each other.