Hub Motor Eddy Current Reduction via Sequence Control
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Solution Overview
Problem
Existing hub motors are inefficient due to high weight, heat generation from eddy current losses, and require multiple units to power electric vehicles, limiting their range and performance.
Innovation Solution
A hub motor design featuring a direct current source, non-magnetic stators with embedded coils, rotors with permanent magnets, a sequence control system, shorting bars, a thin conductive shield, and an energy recovery circuit to minimize inefficiencies and recover energy from collapsing magnetic fields.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If traditional metal hub motors are used, then structural strength is maintained, but weight increases and efficiency decreases
Solution Approach 1:
The patent changes the material parameters of the motor components by using non-metallic materials such as plastic housings and composite structures instead of traditional metals. This parameter change reduces weight while maintaining structural integrity through alternative material properties and design optimizations.
Solution Approach 2:
The patent employs composite materials in the motor construction, combining different materials (e.g., plastic housing with magnetic components, composite rotor structures) to achieve optimal balance between weight reduction and structural strength. The composite approach allows each component to contribute its best properties to the overall system.
2Loss of energy
If traditional hub motor design is used, then simplicity is maintained, but eddy current losses increase causing heat generation
Solution Approach 1:
The patent extracts or removes the source of eddy current losses by using non-conductive magnetic materials and insulating components in the motor structure. By taking out the conductive paths that create eddy currents, the design eliminates the harmful energy losses and associated heat generation while maintaining motor functionality.
Solution Approach 2:
The patent introduces intermediary insulating materials and non-conductive magnetic components that mediate between magnetic fields and conductive elements. These intermediaries prevent direct conductive paths that would create eddy currents, thereby reducing energy losses and heat generation.
3Power
If multiple hub motors are used to power electric vehicles, then required power is achieved, but system complexity and weight increase
Solution Approach 1:
The patent combines multiple motor functions into a single integrated hub motor unit that directly drives the wheel. By merging the motor, transmission, and wheel drive functions into one component, the system achieves required power output without the complexity of multiple separate motors and associated drivetrain components.
Solution Approach 2:
The hub motor design provides multi-functionality by serving as both the power source and the direct wheel driver. This universal component performs multiple functions (power generation, torque transmission, wheel rotation) that would traditionally require separate components, thereby reducing overall system complexity while maintaining required power output.
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
The design results in a lightweight, efficient hub motor with reduced eddy current losses, increased torque, and improved energy recovery, enabling longer vehicle range and performance with fewer motors.
Implementation Method 1
two or more permanent magnets embedded in each rotor... each coil has a non-conductive, non-magnetic core with a conductor wound around the core... the shaft defines an axis of rotation of the two or more rotors
Implementation Method 2
an energy recovery circuit to minimize inefficiencies and recover energy from collapsing magnetic fields
Data Source
AI summary
An apparatus, system, and method are disclosed for an efficient hub motor. A stator is attached to a shaft. Coils are embedded in the stator in a circular pattern. Two rotors are rotatably coupled to the shaft with the stator between them. Permanent magnets are embedded in each rotor. Each permanent magnet and each core has a similar cross-sectional shape. The permanent magnets are positioned in a circular pattern corresponding to the coils. The permanent magnets are positioned so that when a coil aligns with a permanent magnet a next coil aligns between two magnets. Shorting bars connect exterior edges of the permanent magnets. A sequence control connects each coil so that current flows in a coil in one direction and the sequence control disconnects the coil and reconnects the coil with current flowing in the opposite direction in response to a set of permanent magnets aligning with a coil.