Axially Clamped Stator Core Structure for Reduced Iron Loss
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The press-fitting of a stator core into a rotary electric machine case generates in-plane stress, leading to increased iron loss due to the pressing force in the diameter direction, which is not effectively mitigated by existing technologies.
Innovation Solution
A stator core design with a separate annular core back and multiple teeth, where an end plate applies a pressing force in the axial direction to generate out-of-plane stress, reducing iron loss by clamping and pressing both the core back and teeth, with the core back having a larger iron loss than the teeth and the end plate's face projecting further for the core back than for the teeth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the stator core is securely accommodated in the case through press-fitting, then the stator core is firmly fixed, but an in-plane stress is generated in the core back and teeth, increasing the iron loss
Solution Approach 1:
The patent transitions from applying pressing force in the radial direction (in-plane stress) to applying pressing force in the axial direction (out-of-plane stress) through the end plate. This dimensional change in force application allows the stator core to be firmly fixed while avoiding the generation of in-plane stress that increases iron loss.
Solution Approach 2:
Instead of pressing the stator core from the radial direction (conventional approach), the patent inverts the approach by pressing from the axial direction through the end plate. This reversal of the pressing direction transforms the stress from in-plane to out-of-plane, resolving the contradiction between firm fixation and iron loss reduction.
2Reliability
If the core back and teeth are pressed in the diameter direction, then they are securely fixed in the case, but the iron loss of the core back and teeth increases due to in-plane stress
Solution Approach 1:
The patent changes the dimension of force application from radial (diameter direction) to axial direction. The end plate applies pressing force in the axial direction, generating out-of-plane stress instead of in-plane stress, thereby achieving secure accommodation without increasing iron loss.
Solution Approach 2:
The patent changes the parameter of stress direction from in-plane to out-of-plane by modifying the pressing direction. This parameter change in stress orientation allows the stator core components to be securely fixed while minimizing iron loss.
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 design effectively reduces the iron loss of the stator core by converting in-plane stress to out-of-plane stress, specifically reducing the iron loss of both the core back and teeth through controlled clamping and pressing with an end plate.
Implementation Method 1
an end plate for clamping and pressing the core back and the teeth in the axial direction... generates an out-of-plane stress in each of the core back and teeth
Implementation Method 2
a pressing force in the diameter direction acts on the stator core due to press-fitting into the case, which generates an in-plane stress in the stator core
Data Source
AI summary
Provided is a stator including a stator core composed of an annular core back and teeth projecting from the inner circumference side of the core back, and an end plate for clamping and pressing at least one end side of the core back and the teeth in the axial direction.