Rotor Magnet Curvature Layout for Lower Cogging Torque
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Solution Overview
Problem
Existing motors face challenges in reducing cogging torque, which affects their performance and quality, particularly in applications like electronic power steering systems where stable output and quick restoring forces are required.
Innovation Solution
The motor design incorporates a rotor core with a combination of first and second magnets of different shapes and dimensions, where the second magnets are placed between the first magnets, with varying thickness and curvature, to minimize cogging torque.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If magnets are formed to have the same size and shape, then stable output power is secured, but cogging torque cannot be reduced
Solution Approach 1:
The rotor magnet is divided into two distinct segments: a first magnet and a second magnet, each with different outer circumferential surface curvatures. This segmentation allows each magnet to contribute differently to the magnetic field distribution, reducing cogging torque while maintaining stable output power through complementary magnetic interactions.
Solution Approach 2:
Different regions of the rotor magnet are given different local properties through varying the outer circumferential surface curvature of the first and second magnets. The first magnet has a greater curvature than the second magnet, creating localized magnetic field variations that reduce cogging torque while preserving overall motor performance.
2Object-generated harmful factors
If two kinds of magnets with different shapes are used, then cogging torque is reduced, but device complexity increases
Solution Approach 1:
The rotor magnet employs an asymmetric configuration where the first magnet and second magnet have different outer circumferential surface curvatures. This asymmetry is deliberately designed to create favorable magnetic field distribution patterns that reduce cogging torque, while the overall structure remains symmetric enough to maintain manufacturing feasibility.
Solution Approach 2:
The invention changes the geometric parameter of the magnet's outer circumferential surface curvature to reduce cogging torque. By adjusting the curvature of the first and second magnets differently, the magnetic field distribution is optimized to minimize harmful cogging effects while maintaining a relatively simple overall magnet structure.
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 effectively decreases cogging torque, enhancing the motor's quality and performance by optimizing the interaction between the magnets and the rotor core, leading to improved rotational stability and efficiency.
Implementation Method 1
the stator 30 of the motor 2 generates an electrical interaction with the rotor 40 to induce rotation of the rotor 40
Implementation Method 2
a plurality of first magnets 420 and second magnets 430 disposed along an outer circumferential surface of the rotor core 410
Data Source
AI summary
An embodiment relates to a rotor and a motor comprising same, the rotor comprising: a rotor core; and a plurality of first magnets and second magnets arranged along the outer circumferential surface of the rotor core, wherein each of the second magnets is disposed between the first magnets, and the outer circumferential surface of each of the first magnets has a curvature greater than that of the outer circumferential surface of the second magnet. Therefore, the motor can reduce cogging torque by using the first magnet and the second magnet having different shapes, and thus can improve the quality of the motor.