IPM Motor Rotor Magnet Insertion and Positioning
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Solution Overview
Problem
In IPM motors, a large force is required to insert the permanent magnet into the magnet insertion hole, and the magnet tends to shift during resin sealing, leading to displacement issues.
Innovation Solution
A rotor design featuring laminated disk-shaped rotor core members with a magnet insertion hole that includes a contact portion and a deformation allowing portion, allowing easy insertion and positioning of the rotor magnet, preventing displacement during resin sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a leaf spring portion is used to fix the permanent magnet in the magnet insertion hole, then the permanent magnet can be secured in position, but a large insertion force is required and the magnet may shift during resin sealing
Solution Approach 1:
The invention changes the physical state of the contact portion by providing a deformation allowing portion, enabling the contact portion to elastically deform during magnet insertion and then recover to provide securing force. This transforms the rigid leaf spring structure into a flexible deformation mechanism that requires less insertion force while maintaining positioning stability
Solution Approach 2:
The contact portion is designed to dynamically change its shape through the deformation allowing portion, transitioning from a deformed state during insertion to a recovered state for securing the magnet. This dynamic behavior allows the structure to adapt to the insertion process and then provide stable positioning
2Reliability
If the rotor core and rotor magnet are sealed with resin, then the structure is protected, but the rotor magnet tends to be displaced due to resin flow
Solution Approach 1:
The deformation allowing portion is provided in advance to enable the contact portion to deform and accommodate the magnet during insertion before resin sealing occurs. This preliminary design feature prevents magnet displacement during the subsequent resin filling process by ensuring the magnet is properly seated and secured before the resin is applied
3Power
If multiple rotor core members are laminated to form the rotor core, then the magnetic performance is improved, but the complexity of ensuring proper magnet positioning across multiple layers increases
Solution Approach 1:
The invention divides the rotor core into multiple disk-shaped rotor core members that are laminated together, with each member having its own deformation allowing portion and contact portion. This segmentation allows the magnet positioning function to be distributed across multiple layers, simplifying the overall design while maintaining magnetic performance
Solution Approach 2:
The deformation allowing portion serves multiple functions: it enables elastic deformation of the contact portion during magnet insertion, provides a recovery mechanism to secure the magnet in position, and ensures consistent magnet positioning across all laminated rotor core members. This multi-functionality reduces the need for additional positioning components
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
Enables easy insertion and secure positioning of the rotor magnet, reducing the risk of displacement and improving magnetic field generation while curbing vibration and torque ripple.
Implementation Method 1
a deformation allowing portion that allows deformation of the contact portion and is located on the side opposite to the magnet insertion hole with at least one of the contact portions interposed therebetween
Data Source
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AI summary
A configuration is obtained in which a rotor magnet can be easily inserted into a magnet insertion hole and shifting of the rotor magnet in the magnet insertion hole can be curbed. A rotor (2) for an IPM motor (1) has multiple disk-shaped rotor core members (24) that are laminated in the thickness direction to form a columnar rotor core (21) through which a magnet insertion hole (23) penetrates in the axial direction, and a rotor magnet (22) that is inserted into the magnet insertion hole (23). At least one of the multiple rotor core members (24) forms a part of the inner edge of the magnet insertion hole (23), and has a protrusion (55) that comes into contact with the rotor magnet (22) inserted in the magnet insertion hole (23), and a deformation allowing portion (60) that allows deformation of the protrusion (55) and is located on the side opposite to the magnet insertion hole (23) with at least one of the protrusions (55) interposed therebetween in plan view of the rotor core member (24) as viewed from the thickness direction.