Motor Rotor Mold Resin Guide for Magnet Stability
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Solution Overview
Problem
The existing permanent magnet type rotor designs face issues with demagnetization due to resin molding heat, leading to uneven magnetic flux and instability, causing vibration and noise during rotation.
Innovation Solution
A motor design with a rotor featuring a shaft, stator, and bearing, where permanent magnets are inserted between core pieces with guide parts in the mold resin, ensuring stable attachment and balanced magnetic flux, inhibiting vibration and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If permanent magnets are disposed between core pieces and attached by magnetic force, then the risk of demagnetization due to resin molding heat is reduced, but the location of permanent magnets becomes irregular causing uneven magnetic flux and rotor instability
Solution Approach 1:
A guide part is introduced as an intermediary component within the magnet insertion hole to mediate between the permanent magnet and the core piece. This guide part provides a physical reference structure that ensures accurate positioning of the permanent magnet in the circumferential direction, resolving the location precision issue while maintaining the magnetic force attachment method that prevents demagnetization
Solution Approach 2:
The guide part is pre-formed as an integral structure with the core piece before the permanent magnet is inserted. This preliminary action establishes the correct position and orientation of the permanent magnet in advance, ensuring uniform magnetic flux distribution and preventing rotor instability before the magnet is attached by magnetic force
2Ease of manufacture
If permanent magnets are attached to one side of neighboring core pieces, then attachment is simplified, but the center of gravity balance in the circumferential direction deteriorates causing vibration and noise
Solution Approach 1:
The guide part is designed with asymmetric positioning within the magnet insertion hole, specifically located closer to one core piece than the other. This asymmetric structure intentionally creates a reference point that guides the permanent magnet to a specific position, ensuring that the magnet is attached to the intended side of the core piece. This resolves the center of gravity balance issue by preventing incorrect attachment while maintaining the simplified magnetic force attachment method
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
The design stabilizes the rotor's rotation by ensuring even magnetic flux and center of gravity balance, reducing vibration and noise.
Implementation Method 1
a plurality of permanent magnets to magnetize the core piece part
Implementation Method 2
the permanent magnet is attached to either side of the neighboring yolk parts by using magnetic force
Data Source
AI summary
A motor may include a rotor including a shaft; a stator; and a bearing supporting the shaft. The rotor may include a plurality of core pieces on an outer side of the shaft, a plurality of permanent magnets, and a mold resin part between the core pieces. The neighboring core pieces may include a magnet insertion hole provided therebetween. The permanent magnet may include two poles, with poles of neighboring magnets facing each other having identical polarity. The mold resin part may include at least one first guide part disposed closer to one side than the center between neighboring core pieces, and covers at least a portion of a surface on one side of the magnet insertion hole in a circumferential direction, the permanent magnet being in direct indirect contact via resin with the core piece disposed on the other side of the magnet insertion hole.