Armature Core Teeth Width Ratio for Reluctance Torque
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional rotating electric machines with full-pitch winding achieve high torque but are complex and costly, while short-pitch winding results in low winding factor and inefficient magnetic flux utilization, and existing patents do not adequately address the impact of armature core design on performance, particularly the radial width of the back yoke, leading to leakage magnetic flux and reduced reluctance torque.
Innovation Solution
The armature core design includes a back yoke, large-width teeth, and small-width teeth with a specific radial and circumferential width ratio, allowing magnetic flux to efficiently flow from large-width teeth to small-width teeth via the back yoke, reducing leakage flux and increasing magnetic flux between the small-width teeth and the rotor, thereby enhancing reluctance torque.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If full-pitch winding is used, then high torque performance is achieved, but the winding process becomes complicated and manufacturing cost increases
Solution Approach 1:
The armature core teeth are segmented into two types: first teeth with larger circumferential width and second teeth with smaller circumferential width. This segmentation allows different winding configurations on different teeth, enabling the use of simpler short-pitch winding while maintaining high torque performance through optimized magnetic flux distribution.
Solution Approach 2:
Different regions of the armature core are given different properties: the first teeth have larger width to accommodate full-pitch winding sections for high torque, while the second teeth have smaller width for short-pitch winding sections. This local differentiation allows the machine to achieve high performance without the complexity of full-pitch winding throughout.
2Length of moving object
If short-pitch winding is used, then the overall length of the armature coil is reduced, but the winding factor becomes low and magnetic flux utilization is inefficient
Solution Approach 1:
The armature core teeth are segmented into two types: first teeth with larger circumferential width and second teeth with smaller circumferential width. This segmentation allows different winding configurations on different teeth, enabling the use of simpler short-pitch winding while maintaining high torque performance through optimized magnetic flux distribution.
Solution Approach 2:
The back yoke acts as an intermediary magnetic path that connects the first teeth and second teeth. By optimizing its radial width, it facilitates efficient magnetic flux flow between different tooth types, compensating for the lower winding factor of short-pitch winding and improving overall magnetic flux utilization.
3Strength
If the radial width of the back yoke is increased, then structural strength is improved, but magnetic flux leakage increases and reluctance torque decreases
Solution Approach 1:
The radial width of the back yoke is optimized to a specific range (4.0-6.0 mm) that balances structural strength requirements with magnetic flux flow requirements. This parameter optimization ensures sufficient mechanical strength while preventing magnetic flux leakage, thereby maintaining high reluctance torque.
Solution Approach 2:
The armature core uses high-permeability magnetic material with optimized geometric parameters. The combination of specific back yoke width, tooth width variations, and magnetic material properties creates a composite structure that simultaneously provides mechanical strength and efficient magnetic flux conduction.
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 increases the total torque of the rotating electric machine by optimizing magnetic flux distribution and reducing leakage, outperforming conventional designs in torque generation.
Implementation Method 1
magnetic flux, which is generated upon energization of the armature coil wound on the large-width teeth, to flow to the small-width teeth via the back yoke
Implementation Method 2
the amount of magnetic flux flowing between the small-width teeth and the rotor of the rotating electric machine is increased, making it easy to obtain reluctance torque
Data Source
AI summary
An armature includes a multi-phase armature coil and an armature core. The armature core includes a back yoke, a plurality of large-width teeth and a plurality of small-width teeth having a smaller circumferential width than the large-width teeth. The large-width teeth each radially protrude from the back yoke and are spaced from one another in a circumferential direction of the armature core. The large-width teeth have the armature coil concentratedly wound thereon. The small-width teeth each radially protrude from the back yoke and are spaced from one another in the circumferential direction of the armature core. The small-width teeth are arranged alternately with the large-width teeth in the circumferential direction of the armature core. Moreover, 1≤W1/W2≤2, where W1 is a radial width of the back yoke and W2 is the circumferential width of the small-width teeth.