Permanent Magnet Rotor Resin Fixing for Higher Holding Force
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Solution Overview
Problem
Existing rotor manufacturing methods face challenges in maintaining or increasing permanent magnet holding force while simplifying the manufacturing process.
Innovation Solution
The rotor design includes a rotor shaft, a rotor core with magnet housing holes, permanent magnets with exposed corners, and a resin part that fixes the magnets. The resin part consists of a core end surface resin section and an in-core resin section, which together provide enhanced holding force and manufacturing ease.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the two rotor core gripping resin parts and the magnet fixing resin part are formed simultaneously as a single integrated piece, then manufacturing efficiency is improved and manufacturing costs are reduced, but the permanent magnet holding force may be reduced due to the use of resin
Solution Approach 1:
The resin part is segmented into three distinct functional sections: two rotor core gripping resin parts that hold the rotor core, and a magnet fixing resin part that holds the permanent magnets. This segmentation allows each section to be optimized for its specific function while maintaining the benefit of simultaneous formation as an integrated piece, thereby improving manufacturing efficiency without compromising holding force.
Solution Approach 2:
Different regions of the resin part are designed with different properties and functions. The rotor core gripping resin parts are positioned to securely hold the rotor core, while the magnet fixing resin part is specifically configured to hold the permanent magnets. This local differentiation ensures that each region provides the appropriate holding force for its intended purpose, maintaining overall structural integrity and magnet holding force despite the use of resin throughout.
2Device complexity
If positioning pins or similar positioning features are eliminated to simplify the manufacturing process, then device complexity is reduced, but the permanent magnet holding force may be compromised
Solution Approach 1:
The resin part itself serves the dual function of both positioning and holding the permanent magnets. By designing the resin part with appropriate geometry and positioning structures integrated into its form, the system eliminates the need for separate positioning pins or features. The resin part automatically positions the magnets during injection molding and subsequently holds them securely, simplifying the manufacturing process while maintaining holding force through the resin's inherent bonding capability.
3Strength
If more resin is used to increase permanent magnet holding force, then the holding force is improved, but the weight of the rotor increases
Solution Approach 1:
The resin part is designed to provide just enough holding force for the permanent magnets without excessive resin material. The magnet fixing resin part is configured with optimized dimensions and geometry that provide sufficient bonding strength to secure the magnets during operation, while avoiding unnecessary resin that would increase rotor weight. This partial action approach ensures adequate holding force is achieved with minimal resin usage.
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 allows for easier rotor manufacturing while maintaining or increasing the permanent magnet holding force, reducing the likelihood of holding force reduction despite using resin for the holding parts.
Implementation Method 1
a resin part that fixes the permanent magnet. The resin part includes a core end surface resin section provided at least on one of end surfaces of the rotor core in the axial direction, and an in-core resin section provided to fill the gap and connected to the core end surface resin section
Data Source
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AI summary
A rotor 1 includes a rotor shaft 11, a rotor core 12 including a magnet housing hole 122, a permanent magnet 13 housed in the magnet housing hole with a gap therebetween, and a resin part 14 that fixes the permanent magnet. The resin part 14 includes a core end surface resin section 141 provided on an end surface of the rotor core and an in-core resin section 143 provided to fill the gap between the permanent magnet and the magnet housing hole. The core end surface resin section 141, as seen in an axial direction, is configured to cover a portion of an end surface of the permanent magnet 13 by covering a portion of the magnet housing hole 122 and to expose at least two corners and of the end surface of the permanent magnet 13 by not covering portions of long edges and, and short edges and that define the at least two corners. This makes it easier to manufacture the rotor while maintaining or increasing permanent magnet holding force.