Rotor Design for Reducing Cogging Torque and Vibration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional motors face challenges in reducing cogging torque and torque ripple simultaneously due to the trade-off relationship with skew angle, leading to torque reduction and limited vibration and noise reduction.
Innovation Solution
A rotor design featuring alternating sets of magnet and magnetic assemblies on its radial surface, arranged in a specific pattern to generate opposite phases of cogging torque and torque ripple without applying skew, thereby canceling out fluctuations and reducing vibration and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If skew is applied to reduce cogging torque, then cogging torque is reduced, but torque is reduced
Solution Approach 1:
The rotor is divided into multiple regions along the axial direction, with each region containing magnet assemblies arranged in different circumferential positions. This segmentation allows different regions to generate cogging torques with different phases, which can cancel each other out, reducing overall cogging torque without requiring skew and thus avoiding torque reduction.
Solution Approach 2:
Magnet assemblies in different regions are arranged asymmetrically along the circumferential direction, creating phase differences in the generated cogging torque. This asymmetric arrangement enables cogging torque cancellation while maintaining symmetric torque production, resolving the contradiction between reducing cogging torque and maintaining torque output.
2Object-generated harmful factors
If conventional methods are used to reduce cogging torque, then cogging torque is reduced, but vibration and noise reduction is limited
Solution Approach 1:
The rotor is divided into multiple regions along the axial direction, with each region containing magnet assemblies arranged in different circumferential positions. This segmentation allows different regions to generate cogging torques with different phases, which can cancel each other out, reducing overall cogging torque without requiring skew and thus avoiding torque reduction.
Solution Approach 2:
Magnet assemblies in different regions are arranged asymmetrically along the circumferential direction, creating phase differences in the generated cogging torque. This asymmetric arrangement enables cogging torque cancellation while maintaining symmetric torque production, resolving the contradiction between reducing cogging torque and maintaining torque output.
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 cogging torque and torque ripple while preventing torque reduction, allowing for decreased magnet usage and lower production costs by canceling out cogging torque and torque ripple phases, resulting in reduced motor vibration and noise.
Implementation Method 1
a motor includes a rotor and a stator. The rotor includes at least one magnet
Implementation Method 2
The rotor includes at least one magnet
Implementation Method 3
providing protrusions or skews that generate phase inversion
Implementation Method 4
reduce both a cogging torque and a torque ripple
Data Source
AI summary
First and second sets of magnet assemblies and magnetic assemblies are alternately arranged in a circumferential direction in a first portion along an axial direction, and the first and second sets are alternately arranged in the circumferential direction in a second portion along the axial direction. When viewed in the axial direction, the first set of the first portion and the second set of the second portion overlap with each other, and the second set of the first portion and the first set of the second portion overlap with each other.