Stator Bobbin-Embedded Tooth Tips for Torque Ripple Reduction
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Solution Overview
Problem
Existing electric motor stators in hybrid electric vehicles experience torque ripple due to variations in the magnetic field as the rotor position changes, leading to inefficiencies in torque transmission.
Innovation Solution
Incorporating magnetically conductive inserts within cavities of resin bobbins, which are wound with electrically conductive wire and installed over a magnetically conductive stator ring, effectively widens the tooth tips to reduce torque ripple, utilizing a triangular or varying cross-sectional area configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If magnetically conductive inserts are installed within the cavities of resin bobbins, then torque ripple is reduced by stabilizing the magnetic field interaction, but device complexity increases due to additional components and assembly steps
Solution Approach 1:
The magnetically conductive inserts are nested within the cavities of the resin bobbins, creating a hierarchical structure where one component is embedded within another. This allows the inserts to be integrated into the existing stator structure without requiring separate mounting spaces, thereby reducing torque ripple while adding minimal structural complexity.
Solution Approach 2:
The stator combines multiple materials with different properties: resin bobbins for insulation and structural support, magnetically conductive inserts for field stabilization, and electrically conductive wire for power transmission. This composite approach allows each material to address specific requirements, reducing torque ripple through the magnetic inserts while maintaining overall stator functionality.
2Stability of the object's composition
If magnetically conductive inserts are used to widen tooth tips, then magnetic field stability is improved, but manufacturing complexity increases due to additional assembly steps
Solution Approach 1:
The magnetically conductive inserts are pre-installed within the resin bobbin cavities before the wire winding process. This preliminary action ensures that the inserts are correctly positioned to widen the tooth tips and stabilize the magnetic field, while allowing subsequent manufacturing steps to proceed without additional complexity.
Solution Approach 2:
The stator is divided into discrete components: resin bobbins with embedded inserts, tooth structures, and wire windings. This segmentation allows each component to be manufactured and prepared separately, then assembled in a standardized sequence, improving manufacturing efficiency despite the additional insert component.
3Reliability
If multiple inserts of varying cross sectional area are present on each side of each tooth, then torque ripple reduction is optimized, but device complexity and manufacturing difficulty increase
Solution Approach 1:
Different inserts with varying cross-sectional areas are placed at specific locations on each side of the teeth, creating local variations in magnetic conductivity. This local quality approach optimizes torque ripple reduction at specific critical points in the magnetic field path, rather than using uniform inserts throughout, thereby achieving better performance with targeted complexity.
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 reduces torque ripple by stabilizing the magnetic field interaction, enhancing the efficiency and performance of the electric motor by minimizing torque variations.
Implementation Method 1
The magnetic field is guided by magnetically conductive material in the stator and in the rotor. This magnetic field interacts with permanent magnets in the rotor to create torque.
Implementation Method 2
The magnetically conductive inserts are installed within the cavities thereby effectively widening the tooth tips to reduce torque ripple of the electric motor.
Data Source
AI summary
A stator for a hybrid electric vehicle combines the best features of complete stators and segmented stators. The bobbins of a complete stator are modified to effectively widen the teeth and thereby reduce torque ripple. Each resin bobbin includes cavities on either side of the tooth. The cavities are filled with a magnetically conductive insert. In some embodiments, a single wedge shaped insert is installed on each side of each tooth. In other embodiments, multiple inserts of varying cross sectional area are installed on each side of each tooth.