Segmented Rotor Magnets for Compressor Motor Vibration Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electric motors with permanent magnets face challenges such as increased vibration, noise, and manufacturing costs due to the use of high-priced magnetic materials, which also lead to rotor inertia issues and bearing abrasion in compressors.
Innovation Solution
The design incorporates a rotor magnet with alternating first and second magnetic portions, where the second magnets generate stronger magnetic flux than the first magnets, reducing the need for expensive materials and facilitating fabrication, while the rotor frame is made of a non-magnetic material to support the magnets and reduce mass.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If high-priced magnetic materials are used to increase magnetic flux density, then output power is improved, but fabricating cost increases
Solution Approach 1:
The rotor magnet is divided into multiple permanent magnets arranged in an alternating pattern around the rotor circumference. This segmentation allows the use of smaller, more cost-effective permanent magnet pieces while collectively achieving the required magnetic flux density through their combined effect, thereby reducing fabricating cost while maintaining output power.
Solution Approach 2:
The invention employs permanent magnets with specific local arrangements where each magnet is positioned to contribute to the overall magnetic flux density in a targeted manner. This local optimization ensures that magnetic flux is distributed effectively across the air gap, achieving high output power without requiring expensive high-density magnetic materials throughout the entire rotor structure.
2Power
If rotor mass is increased to improve magnetic flux density, then output power is improved, but vibration and noise increase
Solution Approach 1:
The rotor magnet structure is segmented into multiple smaller permanent magnets rather than using a single large magnetic mass. This segmentation reduces the overall rotor mass while maintaining sufficient magnetic flux density through the distributed arrangement of magnets, thereby improving output power without increasing vibration and noise associated with heavier rotors.
Solution Approach 2:
The rotor employs a composite structure combining magnetic and non-magnetic materials in a strategically designed arrangement. This composite approach optimizes the magnetic flux density in the air gap while controlling the overall rotor mass, achieving high output power with reduced vibration and noise compared to traditional homogeneous magnetic rotor designs.
3Power
If rotor mass is increased to improve magnetic flux density, then output power is improved, but bearing abrasion increases
Solution Approach 1:
The rotor magnet is divided into multiple smaller permanent magnets arranged circumferentially. This segmentation reduces the total rotor mass compared to a single large magnetic structure, thereby decreasing the centrifugal forces and loads on the bearings during rotation. The reduced bearing loads lead to decreased abrasion and improved reliability, while the distributed magnet arrangement maintains the necessary magnetic flux density for high output power.
4Power
If rotor mass is increased to improve magnetic flux density, then output power is improved, but it becomes difficult to start and stop the rotor
Solution Approach 1:
The rotor magnet structure is segmented into multiple smaller permanent magnets distributed around the rotor. This segmentation reduces the overall rotor mass and moment of inertia compared to a solid large-mass magnetic rotor. The reduced inertia enables faster acceleration and deceleration, making it easier to start and stop the rotor while maintaining sufficient magnetic flux density for high output power through the optimized arrangement of segmented magnets.
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 suppresses vibration and noise, improves output power, and reduces manufacturing costs by optimizing magnetic flux density and reducing cogging torque, thereby enhancing the electric motor's performance and reliability.
Implementation Method 1
An electric motor is an apparatus that can convert electric energy into mechanical energy
Implementation Method 2
a permanent magnet and a rotor frame that includes a rotation shaft to support the permanent magnet
Data Source
AI summary
An electric motor includes a stator, and a rotor spaced apart from the stator by a gap. The rotor includes a first magnet that generates first magnetic flux, that includes first magnetic portions arranged in a circumferential direction of the rotor, and that are configured to generate a magnetic field in the gap, and second magnetic portions that are alternately arranged with the plurality of first magnetic portions along the circumferential direction of the rotor. The rotor further includes a plurality of second magnets that are each located between a first magnetic portion of the first magnetic portions and a second magnetic portion of the second magnetic portions that is adjacent to the first magnetic portion, where each second magnet generates second magnetic flux that is greater than the first magnetic flux, and the first magnet is located radially between the gap and the plurality of second magnets.