Rotary Electric Machine Stator Tooth Pitch Angle Optimization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The cooling capacity of water cooling devices in rotating electric machines is not uniform, leading to uneven temperature distribution and increased volume to manage heat dissipation, limiting the design and efficiency of the machines.
Innovation Solution
A rotating electric machine design with a stator featuring varying tooth pitch angles and coil cross-sectional areas to distribute losses evenly across the stator's cross-section, matched with a cooling device configuration that optimizes cooling performance in the circumferential direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a water cooling device is mounted to cool the stator, then heat dissipation is improved, but the cooling capacity is not uniform and causes local temperature increases
Solution Approach 1:
The invention applies different tooth pitch angles to different circumferential positions of the stator to match the non-uniform cooling capacity. Specifically, the first tooth pitch angle is set larger than the second tooth pitch angle in the region where cooling capacity is lower, thereby distributing losses uniformly across the stator cross-section and preventing local temperature increases.
Solution Approach 2:
The invention changes the geometric parameter of the stator by setting different tooth pitch angles (first tooth pitch angle and second tooth pitch angle) in different circumferential regions. This parameter variation compensates for the non-uniform cooling capacity and achieves uniform loss distribution, thereby improving temperature uniformity.
2Temperature
If the machine volume is increased to improve heat dissipation, then cooling performance is improved, but the device complexity and size increase
Solution Approach 1:
Instead of uniformly increasing the machine volume, the invention applies local optimization by varying the tooth pitch angles in specific circumferential regions. This allows uniform loss distribution and effective heat dissipation without increasing the overall machine volume.
Solution Approach 2:
The invention achieves improved heat dissipation through parameter optimization (different tooth pitch angles) rather than volume increase. By adjusting the tooth pitch angles to match the cooling capacity distribution, uniform loss distribution is achieved without expanding the machine size.
3Reliability
If the loss distribution in the stator is made uniform, then temperature distribution is improved, but the device complexity increases
Solution Approach 1:
The invention achieves uniform loss distribution through a relatively simple structural modification: setting different tooth pitch angles in different circumferential regions. This local variation in geometry, rather than complex cooling systems or control mechanisms, suffices to improve temperature distribution.
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 allows for efficient heat dissipation without increasing the machine's volume, maintaining efficiency and preventing local temperature increases, thus enhancing the design flexibility and performance of the rotating electric machine.
Implementation Method 1
the cooling water absorbs heat from the outer peripheral surface of the stator
Implementation Method 2
the cooling water circulates in the water path in the frame
Data Source
AI summary
Provided is a rotating electric machine. Angles formed by tooth center axes of adjacent teeth are defined as tooth pitch angles. Maximum tooth pitch angles are defined as first tooth pitch angles α1. At least one of tooth pitch angles become smaller as proceeding from the first tooth pitch angles α1 in a clockwise direction and a counterclockwise direction, respectively, and such tooth pitch angles are defined as second tooth pitch angles α3. Cross-sectional areas of second coils, which are arranged in slots each formed between adjacent teeth corresponding to the second tooth pitch angles α3 in a cross-section perpendicular to a rotation axis, is smaller than cross-sectional areas of first coils, which are arranged in slots each formed between adjacent teeth corresponding to the first tooth pitch angles α1 in the cross-section perpendicular to the rotation axis.