Rotor and motor including same
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Solution Overview
Problem
Conventional rotors used in washing machines suffer from magnetic flux leakage, increased weight due to rigid iron plates, and generate noise and vibration, making them inefficient and costly to manufacture.
Innovation Solution
A rotor design featuring a plastic rotor frame formed by injection molding, with magnets and rotor cores alternately arranged in the circumferential direction, and a coupler connected to a shaft, where the rotor frame includes a coupler base, extension base, and rotary base, with crossing ribs and radial ribs to minimize flux leakage and enhance structural integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If an iron plate is used as the rotor frame to secure rigidity, then the structural strength is improved, but the weight of the rotor increases and magnetic flux leaks
Solution Approach 1:
The rotor frame is constructed using a composite structure combining a non-magnetic metal core (aluminum or copper) with a magnetic sheet layer (silicon steel). This composite design provides the necessary mechanical strength and rigidity while preventing magnetic flux leakage, as the non-magnetic core does not conduct magnetic flux and the magnetic sheet guides it properly.
Solution Approach 2:
The magnetic function is extracted from the structural frame by using a separate magnetic sheet layer bonded to the non-magnetic metal core. This separation allows the frame to focus on providing mechanical strength while the magnetic sheet handles flux guidance, eliminating the flux leakage problem of solid iron plates.
2Strength
If a thick iron plate is used to secure rotor frame rigidity, then the structural strength is improved, but the manufacturing cost increases
Solution Approach 1:
The composite structure of non-magnetic metal core with magnetic sheet layer uses materials more efficiently than solid iron plates. The non-magnetic metal provides strength at lower weight and cost, while the thin magnetic sheet suffices for flux guidance, reducing overall material costs and manufacturing complexity.
Solution Approach 2:
The rotor frame is segmented into functional layers: the non-magnetic metal core for structural support and the magnetic sheet for flux guidance. This segmentation allows each component to be optimized independently and assembled efficiently, reducing manufacturing costs compared to monolithic thick iron plates.
3Power
If magnets are arranged in the circumferential direction on the rotor frame, then the motor output is improved, but magnetic flux leaks outward in the radial direction
Solution Approach 1:
The magnetic sheet layer bonded to the non-magnetic metal core effectively contains and guides magnetic flux in the circumferential direction. The non-magnetic core prevents radial flux leakage while the magnetic sheet maintains strong circumferential flux for high motor output.
Solution Approach 2:
The magnetic flux containment function is extracted and assigned to the magnetic sheet layer, which is specifically designed to guide flux circumferentially. This separates the flux guidance function from the structural support function, preventing radial leakage while maintaining high output.
4Strength
If crossing ribs are added to the extension base to enhance rigidity, then the structural strength is improved, but the device complexity increases
Solution Approach 1:
The crossing ribs create a grid-like reinforcement pattern on the extension base that provides maximum rigidity with minimal material. This geometric pattern is efficient and can be manufactured using standard injection molding or stamping processes, balancing structural strength with manufacturing simplicity.
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 reduces magnetic flux leakage, decreases weight, enhances rigidity and strength, minimizes noise and vibration, and allows for easier manufacturing and reduced material costs, while maintaining high efficiency and output.
Implementation Method 1
A motor is a device that drives a rotor using electromagnetic force generated between the rotor and a stator
Implementation Method 2
the rotor frame is provided with a plurality of radial ribs extending in the radial direction and arranged in the circumferential direction at uniform intervals
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
Disclosed are a rotor that is capable of more efficiently using magnetic flux from magnets and a motor including the same. The rotor includes a plurality of rotor cores, a plurality of magnets magnetized such that magnetic flux is formed in the circumferential direction, the magnets and the rotor cores being alternately arranged in the circumferential direction, a coupler connected to a shaft, and a rotor frame including a coupler base connected to the coupler, an extension base extending from the coupler base in the radial direction, and a rotary base extending from the extension base in the axial direction of the shaft for supporting the rotor cores and the magnets while surrounding the rotor cores and the magnets, wherein the coupler base, the extension base, and the rotary base are integrally formed by injection molding, and the rotor frame is coupled to the coupler, the rotor cores, and the magnets, and wherein the extension base is provided with crossing ribs that cross in the radial direction.