Self-Contained Bearing With Inductive Rotor Power Transfer
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Solution Overview
Problem
Existing electric motors with sliding conductors for current transfer experience wear, debris accumulation, and increased friction, while permanent magnet rotors are heavy and environmentally detrimental due to rare earth materials.
Innovation Solution
A self-contained bearing assembly with wireless power transmission using inductive coupling between transmitter and receiver coils, integrated within the bearing, to supply power to the rotor coils without physical contact, reducing friction and weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sliding conductors are used to transfer current from fixed to rotatable conductors, then power can be supplied to the rotor electromagnetic coils, but wear and debris accumulation occur reducing power transfer reliability
Solution Approach 1:
The patent replaces the mechanical sliding contact system with an inductive coupling system using transmitter and receiver coils. The transmitter coil is mounted on the rotor shaft while the receiver coil is mounted on the stator, eliminating mechanical wear and debris accumulation by using electromagnetic field coupling instead of physical contact for power transfer.
Solution Approach 2:
The patent introduces electromagnetic fields as an intermediary between the transmitter and receiver coils to transfer power. This intermediary mechanism allows power transfer without direct mechanical contact, thereby eliminating wear and contamination issues associated with sliding conductors.
2Power
If sliding contact between conductors is used for power transfer, then current can be supplied to the rotor, but friction loading on the rotor shaft increases
Solution Approach 1:
The patent substitutes the mechanical sliding contact system with an inductive coupling system using transmitter and receiver coils. The transmitter coil is mounted on the rotor shaft while the receiver coil is mounted on the stator, eliminating mechanical wear and debris accumulation by using electromagnetic field coupling instead of physical contact for power transfer.
3Reliability
If permanent magnets are used in the rotor to eliminate the need for current supply, then the system becomes more robust, but the magnets are substantially large increasing vehicle weight
Solution Approach 1:
The patent replaces the permanent magnet system with an electromagnetic coil system powered through inductive coupling. This allows the rotor to generate magnetic fields through electromagnets rather than relying on large permanent magnets, thereby reducing vehicle weight while maintaining system robustness through contactless power transfer.
4Power
If large permanent magnets made of rare earth elements are used to generate sufficient torque, then the motor can drive an electric vehicle, but environmental damage results from mining and processing these materials
Solution Approach 1:
The patent changes the fundamental approach from using rare earth permanent magnets to using electromagnets with inductive power transfer. This parameter change eliminates the need for rare earth element mining and processing, thereby reducing environmental impact while maintaining the ability to generate sufficient motor torque for vehicle 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
Enhances power transfer reliability and efficiency, reduces friction, and eliminates the need for heavy rare earth magnets by using wireless power transfer, thus improving motor performance and environmental impact.
Implementation Method 1
The transmitter coil is electrically connectable with the battery and configured to generate an electromagnetic field when current flows through the transmitter coil. An inner ring is disposable about the shaft and has an inner raceway and a receiver coil spaced axially from the inner raceway so as to be located proximal to and inductively coupled with the transmitter coil. As such, electric current is generated within the receiver coil when current flows through the transmitter coil.
Data Source
AI summary
A bearing assembly includes an annular carrier, an outer ring disposed within the carrier, the outer ring having an outer raceway and a transmitter coil spaced axially from the outer raceway. The transmitter coil is electrically connectable with a battery and is configured to generate an electromagnetic field when current flows through the transmitter coil. An inner ring is disposable about a rotor shaft and has an inner raceway and a receiver coil spaced axially from the inner raceway so as to be located proximal to and inductively coupled with the transmitter coil such that electric current is generated within the receiver coil when current flows through the transmitter coil. The receiver coil is connected to electromagnetic coils of a motor rotor such that electric current flows from receiver coil to the coils. A plurality of rolling elements are disposed between rotatably couple the outer ring with the inner ring.