Electric Generator Rotor Stator Protrusions Cogging Torque
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Solution Overview
Problem
Conventional electric generators have complex structures that insufficiently suppress cogging torque, leading to unstable rotor rotation due to magnetic interactions between the rotor and stator.
Innovation Solution
The use of non-magnetic portions instead of stator side permanent magnets, with specific configurations of rotor and stator protrusions to maintain constant attractive forces regardless of positional relationships, reducing magnetic flux variations and cogging effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the number of turns of the coil is increased to improve power generation efficiency, then the power generation efficiency is improved, but the size of the electric generator is enlarged
Solution Approach 1:
The invention changes the geometric parameters of the rotor and stator protrusions to optimize the magnetic flux distribution and electromagnetic interaction, achieving high power generation efficiency without increasing the number of coil turns or overall generator size
2Force
If conventional structures with rotor and stator permanent magnets are used, then magnetic interaction is achieved, but cogging torque is generated causing unstable rotor rotation
Solution Approach 1:
The invention uses asymmetric protrusion shapes on the rotor and stator that are specifically designed to moderate magnetic flux changes during rotation, reducing cogging torque while maintaining necessary magnetic interaction for power generation
Solution Approach 2:
By changing the geometric parameters of the protrusions (shape, size, positioning), the invention optimizes the magnetic flux distribution to minimize cogging effects while preserving electromagnetic coupling
3Power
If stator side permanent magnets are used to maintain magnetic interaction, then power generation is enabled, but the structure becomes complicated and cogging suppression is insufficient
Solution Approach 1:
The invention extracts the permanent magnets from the stator side, leaving only non-magnetic portions, thereby simplifying the stator structure while maintaining power generation capability through the rotor's magnetic field interaction with the protrusion geometry
Solution Approach 2:
The rotor and stator are segmented into multiple protrusions with specific geometric configurations that work together to generate electromagnetic force while suppressing cogging, replacing the need for complex stator permanent magnet arrangements
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 results in a simpler structure that effectively suppresses cogging torque, ensuring stable rotor rotation and improved power generation efficiency by maintaining constant attractive forces and optimizing magnetic flux usage.
Implementation Method 1
a rotor portion (2) including a rotor yoke (4) made of a soft magnetic material... two grooves (6U, 6L) penetrating from an outer periphery a of the rotor yoke (4)... an annular permanent magnet (7U)... an annular permanent magnet (7L)... a stator portion (3)... two stator yokes (12U, 12L)... two wound portions (17U, 17L)... generating electricity
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The purpose of the present invention is to provide a electric generator which has a simple structure while sufficiently suppressing cogging torque. A electric generator (1) is constituted by a rotor section (2) comprising a plurality of protrusions (8U, 9, 8L) which is arranged linearly with constant pitch at mutually separated positions sandwiching permanent magnets (7U, 7L), and a stator section (3) which has a stator member comprising stator yokes (12U, 12L), permanent magnets (15U, 15L) facing the permanent magnets (7U, 7L), and protrusions (16U1, 16U2, 16L1, 16L2) which protrude closer to the rotor section (2) than the permanent magnets (15U, 15L) and are arranged linearly with constant pitch at mutually separated positions sandwiching the permanent magnets (15U, 15L), the stator member being configured such that the protrusions (16U1, 16U2) and the protrusions (16L1, 16L2) are shifted from each other by a half pitch between adjoining stator members. Further, the rotor section (2)-side protrusions may be shifted by a half pitch instead of the stator section (3)-side protrusions.