Chamfered Permanent Magnet Rotor for Interior Motors
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Solution Overview
Problem
Interior permanent magnet motors face challenges in increasing magnetic force while maintaining productivity, as existing designs with multiple components and V-shaped storage holes lead to increased complexity and component count, affecting efficiency and torque.
Innovation Solution
The rotor design incorporates chamfered permanent magnets with extended circumferential length and chamfered portions to fit within cavities, forming flux barriers and reducing contact with thin rotor core portions, allowing for improved magnetic force and reduced demagnetization risk without increasing component count.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If V-shaped storage holes and multiple magnet storage parts are formed alternately in the circumferential direction to increase magnetic force, then the magnetic force from the rotor is improved, but the number of components increases and productivity deteriorates
Solution Approach 1:
The patent merges multiple magnet storage functions into a single radial storage hole. Instead of having separate V-shaped storage holes and multiple magnet storage parts, the invention uses one radial storage hole that can accommodate multiple magnets arranged in the circumferential direction, thereby reducing the total number of components while maintaining the required magnetic force.
Solution Approach 2:
The radial storage hole is designed to serve multiple functions: it stores multiple magnets, provides structural support, and defines the flux barrier position. This multi-functional design eliminates the need for separate V-shaped storage holes and multiple magnet storage parts, simplifying the overall structure and improving productivity.
2Power
If the number of magnets is increased to improve torque, then the magnetic force is improved, but the device complexity and number of components increase
Solution Approach 1:
Multiple magnets are combined within a single radial storage hole structure, allowing the rotor to achieve high torque through increased magnet count without proportionally increasing device complexity. The unified storage hole design simplifies the overall structure compared to having separate storage features for each magnet.
3Force
If chamfered portions are formed on permanent magnets to improve insertion efficiency and magnetic force, then the magnetic force is improved, but the manufacturing complexity increases
Solution Approach 1:
Chamfered portions are applied locally only at specific corners of the permanent magnets where insertion guidance is needed, rather than modifying the entire magnet structure. This localized modification improves insertion efficiency and magnetic force while minimizing the impact on manufacturing complexity.
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 enhances magnetic force and torque efficiency while simplifying production and reducing demagnetization, improving the overall performance and productivity of interior permanent magnet motors.
Implementation Method 1
permanent magnets are inserted to cavities, so as to form a flux barrier at an end portion of the cavities on a side of an outer peripheral portion of a rotor core
Implementation Method 2
a portion of a cavity other than a flux barrier, facing a chamfered portion of a permanent magnet, is made into a shape that fits to the chamfered portion
Data Source
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AI summary
Disclosed is a rotor for an electric motor in which permanent magnets can be arranged efficiently. A rotor (100) of the electric motor according to the present invention comprises a rotor core (1) constructed by punching out silicon steel laminationplates into a predetermined shape and laminating a predetermined number of the silicon steel lamination plates; a plurality of cavities (2) provided on the rotor core (1); flat-shaped permanent magnets (4) having a cross-sectional face made by a long side and a short side, inserted to the cavities (2); a chamfered portion (4a) formed on a portion of, among intersecting points of the long side and the short side of the permanent magnets (4), at least the intersecting point near an outer peripheral portion of the rotor core (1).