Patterned Rotor Structure for Lightweight High-Power Motors
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Solution Overview
Problem
Conventional motors face challenges with increased weight due to unnecessary metal components, leading to reduced power density and potential torque reduction, while also limiting durability through inadequate structural strength.
Innovation Solution
The motor design incorporates a patterned rotor with hollow portions and strategically placed magnets, reducing weight and enhancing power density by optimizing the lattice structure and magnetic interaction, while maintaining structural integrity through carefully designed hollows and magnet placement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If metal plates are laminated in the axial direction to form the rotor, then the rotor structure is simple and easy to manufacture, but the weight of the rotor is increased
Solution Approach 1:
The patent removes unnecessary metal plates from portions of the rotor that are not electromagnetically affected. Specifically, the rotor core is configured to have a reduced cross-sectional area in the radial direction at portions located radially outward from the electromagnetic interaction region, eliminating redundant metal material while maintaining the necessary electromagnetic functionality.
Solution Approach 2:
The rotor core is designed with non-uniform cross-sectional area distribution, where the cross-sectional area in the radial direction varies depending on the radial position. The area is larger in regions subject to electromagnetic interaction and smaller or reduced in regions not subject to electromagnetic interaction, optimizing material usage locally throughout the rotor structure.
2Strength
If the rotor weight is increased with metal plates, then the rotor structure is robust, but the power density is lowered
Solution Approach 1:
The patent extracts unnecessary metal material from the rotor core in regions not involved in electromagnetic interaction, directly reducing rotor weight. This weight reduction increases power density while the remaining metal structure is strategically positioned to maintain sufficient structural strength for the rotor's operational requirements.
Solution Approach 2:
The patent changes the geometric parameters of the rotor core by varying the cross-sectional area in the radial direction at different radial positions. This parameter optimization reduces material quantity and weight while maintaining the structural integrity needed for rotor operation, thereby improving power density.
3Strength
If metal plates are used throughout the rotor, then structural strength is maintained, but torque reduction occurs due to increased weight
Solution Approach 1:
The patent removes unnecessary metal plates from portions of the rotor not electromagnetically affected, reducing overall rotor weight. This weight reduction decreases the inertial load and improves torque output capability, while the retained metal structure in electromagnetic interaction regions maintains sufficient structural strength.
Solution Approach 2:
The rotor core is designed with spatially varying cross-sectional area, concentrated in regions requiring structural strength for electromagnetic interaction and reduced in non-critical regions. This local optimization maintains necessary strength where needed while reducing weight elsewhere, preserving torque performance.
4Ease of manufacture
If the rotor structure is simplified with metal plates, then manufacturing is easier, but durability is reduced due to insufficient structural strength in critical areas
Solution Approach 1:
The rotor core is designed with non-uniform cross-sectional area distribution, where the area is optimized for each radial position. Regions subject to electromagnetic interaction and mechanical stress maintain larger cross-sectional areas for sufficient structural strength and durability, while non-critical regions have reduced areas. This local optimization ensures durability in critical areas while maintaining overall 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
This design results in a lighter, more efficient motor with improved power density and durability, preventing torque reduction and increasing the motor's lifespan by optimizing the electromagnetic interaction and structural strength.
Implementation Method 1
a rotor rotates due to an electromagnetic interaction between the rotor and a stator
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
An embodiment provides a motor comprising: a stator including a through hole; a cylindrical rotor which is disposed in the through hole; a rotor center shaft which is formed in the central region of the rotor and to which a rotary shaft is coupled; and a first magnet and a second magnet which are disposed between the stator and the rotor, wherein: the rotor includes an outer contour portion and a patterned portion formed between the outer contour portion and the rotor center shaft; the patterned portion includes a plurality of unit patterns and a hollow portion formed in each of the unit patterns; the outer contour portion includes an outer circumferential surface on which the first magnet and the second magnet are disposed and an inner circumferential surface which comes in contact with the plurality of unit patterns; the inner circumferential surface of the outer contour portion further includes a first protrusion portion protruding in a first direction toward the rotor center shaft; and in the first direction, the maximum length of the first protrusion portion is greater than the maximum length of each of the unit patterns.