Electric Motor Rotor Positioning via Magnetic Levitation
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Solution Overview
Problem
Traditional electric motors rely on spindle bearings that are prone to wear and tear, contributing to motor failure and weight, especially in applications like wheeled vehicles where they are subjected to large forces, necessitating a more efficient method to control rotor position.
Innovation Solution
The system employs a controller and motor drive to apply electrical currents to stator windings, generating unbalanced magnetic forces to control the rotor's position, potentially eliminating the need for spindle bearings by using lubricating fluid support and adjusting currents to maintain optimal rotor positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If spindle bearings are used to support the rotor, then the rotor position is stable, but the device weight increases and reliability decreases due to wear and tear
Solution Approach 1:
The patent removes the spindle bearing component from the motor system entirely. Instead of using mechanical bearings to support the rotor, the system employs electromagnetic forces generated by the stator windings to levitate and position the rotor magnetically, eliminating the need for physical contact and bearing-related wear
Solution Approach 2:
The patent replaces the mechanical bearing support system with an electromagnetic field-based rotor positioning system. The controller adjusts electrical currents in the stator windings to generate magnetic forces that hold and position the rotor without mechanical contact, substituting mechanical support with electromagnetic fields
2Stability of the object's composition
If spindle bearings are used to support the rotor, then the rotor position is stable, but the device complexity increases
Solution Approach 1:
The stator windings serve dual functions: they generate the rotating magnetic field for motor operation and simultaneously generate electromagnetic forces for rotor positioning and support. This multi-functionality eliminates the need for separate bearing components while maintaining rotor stability
Solution Approach 2:
The motor system uses its own electromagnetic field generation capability to provide rotor support and positioning. The controller dynamically adjusts the electrical currents in the stator windings to create magnetic forces that automatically hold the rotor in the correct position, making the system self-supporting without external mechanical components
3Reliability
If electrical currents are applied to control rotor radial position, then bearing wear is eliminated, but energy consumption increases
Solution Approach 1:
The controller applies electrical currents to the stator windings selectively and only to the extent necessary for rotor positioning. Rather than continuous full-power application, the system uses minimal adjusted currents to generate sufficient electromagnetic forces for levitation and positioning, reducing overall energy consumption compared to traditional bearing systems
Solution Approach 2:
The controller dynamically adjusts electrical current parameters (magnitude, phase, timing) in the stator windings to optimize the electromagnetic forces for rotor positioning. By precisely controlling these parameters, the system achieves effective rotor support with minimal energy input, adapting current levels to actual positioning needs rather than using fixed high-power operation
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 approach reduces unsprung mass, enhances torque, and minimizes frictional losses, providing a lighter and more reliable electric motor design capable of withstanding harsh environments with dynamic control of the rotor's position.
Implementation Method 1
a rotor that is rotated about a drive axis by electromagnetic interaction with stator poles supporting stator windings
Implementation Method 2
providing an electrical current in one or more of the stator windings to apply a net radial force to the rotor
Data Source
AI summary
A system for controlling an electric motor including a rotor supported by a lubricant upon a stator with a plurality of stator poles and stator windings includes monitoring a radial position and rotor angle of the rotor by a controller. The system includes generating adjustments by the controller to cause the stator poles to apply a net radial force to the rotor. This net radial force may be used, for example to cause the rotor to be centered upon a central axis of the electric motor and may be particularly advantageous for a lubricant supported rotor. A motor drive provides an AC current to the stator windings as well as phase current adjustments of the electrical current in one or more of the stator windings to apply the net radial force to the rotor in a direction perpendicular to the drive axis.