Rotary Electric Machine Axial Rotor Positioning via Field Current
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Solution Overview
Problem
Bearing-less motors face challenges in positioning the rotor within a floatable range due to individual differences in magnetic force and winding states, leading to insufficient supporting forces and potential interference during mechanical positioning.
Innovation Solution
A rotary electric machine design featuring a rotor with axial shaft and circumferentially arranged magnets, a stator with coils, magnetic bearings, and a position adjusting member, allowing for axial and radial positioning of the rotor through field currents and adjustable spacers to manage the rotor's position within a floatable range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If mechanical positioning is attempted to dispose the rotor in the floatable range, then the rotor can be positioned within the floatable range, but interference between the rotor and the positioning portion may occur
Solution Approach 1:
The patent replaces mechanical positioning with magnetic field-based positioning. The stator generates a magnetic field that interacts with the rotor magnets to automatically position the rotor within the floatable range, eliminating the need for mechanical positioning structures and avoiding interference between mechanical components.
Solution Approach 2:
The patent adjusts magnetic field parameters (field current magnitude and distribution) to control the position of the rotor. By changing the electrical parameters of the stator winding, the magnetic force distribution is optimized to achieve precise positioning of the rotor within the floatable range without mechanical contact.
2Force
If the rotor is not arranged within a range of predetermined position in the axial direction at the time of stator start, then the supporting force exerted on the rotor becomes insufficient, but mechanical positioning may cause interference
Solution Approach 1:
The patent applies preliminary magnetic action through the stator field current to position the rotor within the floatable range before正式启动. The magnetic field is activated in advance to generate the necessary supporting force and guide the rotor to the correct position, avoiding the need for mechanical positioning that could cause interference.
3Reliability
If the floatable range depends on individual difference of magnetic force and winding state, then the supporting force can be optimized for each unit, but it becomes difficult to manage quantitatively
Solution Approach 1:
The patent designs a universal control system that can adapt to individual differences in magnetic force and winding state through parameter adjustment. The stator control apparatus provides multi-functional capability to handle variations across different units by adjusting field current parameters, eliminating the need for complex individual management procedures.
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
Enables precise positioning of the rotor within its floatable range, ensuring stable operation and preventing interference, thereby improving the starting efficiency and reliability of the rotary electric machine.
Implementation Method 1
The stator holds the rotor rotatably in the axial direction by a field current caused to flow through the coil
Implementation Method 2
The magnetic bearing includes a cylindrical inner magnet fixed to the rotor and a cylindrical outer magnet fixed to the housing and surrounding the inner magnet, and holds the rotor rotatably in the radial direction
Data Source
AI summary
A rotary electric machine includes: a rotor having a shaft extending in an axial direction and rotor magnets arranged along a circumferential direction; a stator having a coil and surrounding the rotor; a housing supporting the stator; a pair of magnetic bearings on opposite sides in the axial direction of the rotor magnet; and a position adjusting member held by the housing. The stator holds the rotor rotatably in the axial direction by a field current flowing through the coil. The magnetic bearing includes a cylindrical inner magnet fixed to the rotor and a cylindrical outer magnet fixed to the housing and surrounding the inner magnet, and holds the rotor rotatably in the radial direction. The rotor has a stepped surface facing the axial direction. The position adjusting member has an opposing surface facing the stepped surface, and is movable in the axial direction with respect to the housing.