Segmented Rotor Magnet Fixing to Prevent Dislodgement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing magnet-embedded rotors for rotating electric machines face issues with permanent magnets becoming dislodged due to impacts, as they are secured merely by plastic fixing members, leading to potential detachment from the housing holes.
Innovation Solution
The permanent magnets are divided into two segments with division surfaces extending in the direction of the rotor's center line, and are fixed using a thermoplastic fixing member that fills the gap between the magnet and the housing hole, with a tapered design and a lid portion to prevent dislodgement, and allows for a coolant chamber for improved cooling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If permanent magnets are fixed using only plastic fixing members, then the device complexity is reduced and ease of manufacture is improved, but the reliability deteriorates as permanent magnets may dislodge under impact
Solution Approach 1:
The permanent magnet is divided into two segments with a gap between them, allowing the fixing member to engage with both segments and provide more reliable retention while maintaining ease of manufacture through modular assembly
Solution Approach 2:
A protrusion is introduced as an intermediary structural feature between the permanent magnet segments and the fixing member, creating a mechanical interlock that enhances reliability without complicating the manufacturing process
2Device complexity
If permanent magnets are secured with a simple fixing member, then the device complexity is minimized, but the permanent magnets may detach and exit from housing holes under impact
Solution Approach 1:
Dividing the permanent magnet into two segments creates a more stable configuration where the fixing member can anchor into the gap, preventing detachment while keeping the overall device structure simple
Solution Approach 2:
The protrusion acts as a stabilizing intermediary that prevents the permanent magnet segments from shifting or detaching, enhancing stability without adding complex structural elements
Data Source
AI summary
A rotor for a rotating electric machine includes a cylindrical rotor core, a housing hole extending through the rotor core in a direction of a center line of the rotor core, a permanent magnet that is fixed while being accommodated in the housing hole, and a fixing member made of a plastic that fills a gap between an inner surface of the housing hole and an outer surface of the permanent magnet. The permanent magnet is split into two segments such that division surfaces extend in the direction of the center line. The permanent magnet is disposed such that a distance between the two segments decreases from a first end to a second end of the segments in the direction of the center line.