Magnet Carrier Holding Device for Electric Motor Rotor
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Solution Overview
Problem
Existing magnetic element holding devices for electric motor rotors either require resizing of components or additional manufacturing steps when replacing large-volume ferrite magnets with smaller, high remanence magnets, and can adversely affect the magnetic field.
Innovation Solution
A magnetic element holding device with a magnet carrier and holding elements that allows preassembly of smaller magnets, maintaining the original air gap and enabling their integration into existing rotors without altering other components, using a design that compensates for size differences and optimizes the magnetic field.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If smaller high-remanence magnets are used to increase torque density, then magnet volume is reduced, but the installation space becomes excessively large without increasing the air gap
Solution Approach 1:
A magnet holder is introduced as an intermediary component between the rotor and the smaller high-remanence magnets. The magnet holder has a contour matching the original magnet geometry, allowing it to be installed in the rotor's magnet recess. The smaller magnets are then mounted on the magnet holder, which compensates for the size difference and enables proper installation space utilization while maintaining the original air gap dimensions.
2Adaptability or versatility
If an intermediate ring is used to accommodate smaller magnets in the existing rotor, then magnet size compatibility is achieved, but tight geometric tolerances and additional manufacturing steps are required
Solution Approach 1:
The solution is divided into separate functional components: the existing rotor structure remains unchanged, while a separate magnet holder is designed to interface with both the rotor and the smaller magnets. This segmentation allows the magnet holder to be manufactured with appropriate tolerances independently, avoiding the need for tight tolerances on the entire rotor assembly and eliminating complex additional manufacturing steps.
3Reliability
If a magnet holder is placed inside the rotor to secure magnets, then magnet positioning is achieved, but the magnetic field is adversely affected
Solution Approach 1:
The magnet holder is designed with differentiated properties: the outer surface has a contour matching the original magnet geometry for mechanical interfacing with the rotor, while the inner surface provides magnet positioning. The holder material and structure are optimized to minimize magnetic field interference in the operational region, allowing reliable magnet positioning without significant magnetic field degradation.
Data Source
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AI summary
The invention relates to a magnet element holding device (1) for a rotor (10) of an electric motor rotatable about an axis of rotation, with at least one magnet carrier (2) which has at least one receiving section (21) for receiving at least one magnet element (3), and at least one holding element (4) for holding the at least one magnet element (3) in a fixed position within the at least one receiving section (21), wherein the magnet carrier (2) has an outer surface (22) which is designed to be arranged on an inner surface of the rotor (10), wherein a projection (24) is formed on an inner surface (23) of the magnet carrier (2) opposite the outer surface (22), wherein the receiving section (21) and the at least one holding element (4) are formed at a free end (25) of the projection (24).