Permanent Magnet Embedding Holes with Protrusions for Rotor Core
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Solution Overview
Problem
Conventional magnet-embedded motors face issues with increased production steps and costs due to adhesive use, reduced magnetic flux, and potential cracking or chipping of permanent magnets without adhesives, along with noise generation from magnet movement within the rotor core.
Innovation Solution
A motor design featuring a rotor core with permanent magnet embedding holes having specific protrusions and flat portions to securely hold rectangular parallelepiped magnets without adhesives, minimizing clearance and preventing magnet movement during acceleration or deceleration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If adhesive is used to attach permanent magnets to rotor core, then magnets are securely fixed, but production steps increase, cost increases, and magnetic flux is reduced due to required clearance
Solution Approach 1:
The invention extracts and eliminates the adhesive from the magnet fixation system, replacing it with a mechanical interlocking structure formed by protrusions on the rotor core that directly engage with the permanent magnets, thereby simplifying production and avoiding adhesive-related clearance requirements
Solution Approach 2:
The invention adds protrusions that extend from the rotor core surface into the magnet embedding holes, creating a three-dimensional interlocking structure that provides fixation in multiple directions without requiring adhesive layers or additional clearance
2Reliability
If adhesive is used to attach permanent magnets, then magnets are securely fixed, but cost increases
Solution Approach 1:
The invention removes the adhesive material and associated application processes, replacing them with a purely mechanical fixation system using protrusions, thereby eliminating material costs and reducing manufacturing complexity
Solution Approach 2:
The rotor core structure itself provides the fixation function through its protrusions, eliminating the need for separate adhesive materials and application steps, making the system self-sufficient and cost-effective
3Reliability
If clearance is increased to prevent magnet movement without adhesive, then magnet movement is reduced, but magnetic flux short-circuiting increases and torque decreases
Solution Approach 1:
The invention uses protrusions that extend into the magnet embedding holes to provide fixation in the radial direction, allowing minimal clearance to be maintained while preventing magnet movement through mechanical interlocking rather than relying on increased axial clearance
4Reliability
If protrusions are added to embedding hole to prevent magnet movement, then magnet fixation is improved, but manufacturing complexity increases
Solution Approach 1:
The embedding hole is segmented into multiple regions by adding protrusions at specific locations, creating distinct functional zones that provide fixation while maintaining a relatively simple overall structure that can be manufactured using standard processes
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 ensures firm holding of permanent magnets, preventing cracking, chipping, and noise, while maintaining magnetic flux, thus enhancing motor performance and reliability.
Implementation Method 1
valid magnetic flux generated at the rotor core is reduced
Implementation Method 2
a coil around a stator core which includes a salient-pole core and a yoke
Data Source
AI summary
A motor includes a stator and a rotor. The stator is configured by winding a coil around a stator core which includes a salient-pole core. The rotor has a rotor core made by laminating thin and highly permeable iron sheets. The rotor core has multiple permanent magnet embedding holes, and a permanent magnet is embedded in each of the permanent magnet embedding holes. A cross-section of the permanent magnet is a rectangle with a long side in a rotating direction and a short side perpendicular to the long side. A cross section of the permanent magnet embedding hole is formed by an embedding hole's long side corresponding to the long side and an embedding hole's short side corresponding to the short side. The embedding hole's short side has a first protrusion and a flat portion. The embedding hole's long side to an inner diameter side has a second protrusion on its both ends.