Hybrid Radial-Axial Motor Layout for High Torque Density
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Solution Overview
Problem
Conventional induction motors face a decrease in performance metrics such as power factor and efficiency with increasing numbers of poles, leading to longer end coils and increased volume.
Innovation Solution
A radial and axial type hybrid motor design that includes a rotor with conduction bars arranged in radial and axial directions, and end-rings connecting these bars, along with radial and axial stators that generate a rotating magnetic field to increase torque without increasing volume.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the number of poles is increased to improve torque production, then torque increases, but power factor and efficiency decrease
Solution Approach 1:
The motor is segmented into two independent stator systems: a radial stator with fewer poles for efficient power factor and an axial stator with more poles for high torque production. Each stator operates independently with its own winding set, allowing optimization of each subsystem for its specific function without compromising overall efficiency.
Solution Approach 2:
The invention transitions from a conventional single radial stator configuration to a hybrid configuration that adds an axial stator dimension. This dimensional expansion allows the motor to achieve high pole count torque characteristics without the negative effects on power factor that would result from increasing poles in a traditional radial configuration.
2Object-generated harmful factors
If distributed winding is used to reduce harmonics, then harmonic components decrease, but end coil length increases
Solution Approach 1:
The winding system is segmented into two independent sets: radial windings and axial windings. Each winding set can be independently designed and optimized. The axial windings, in particular, can use concentrated winding techniques that produce shorter end coils while the radial windings handle the harmonic reduction function.
Solution Approach 2:
Different winding methods are applied to different stator types based on their specific requirements. The radial stator uses distributed winding for harmonic reduction, while the axial stator can use concentrated winding for compact end coil design. This localized optimization allows each subsystem to achieve its best performance characteristics.
3Volume of stationary object
If end coil length is reduced to decrease motor volume, then overall volume decreases, but torque production capability is limited
Solution Approach 1:
By adding the axial stator dimension, the motor achieves high torque production without requiring proportionally larger volume. The axial flux path provides an additional torque generation mechanism that is more space-efficient than traditional radial flux approaches, allowing high torque density within a compact volume.
Solution Approach 2:
The motor uses a composite structure combining radial and axial stator systems, each contributing differently to torque production. This composite configuration allows the motor to achieve higher specific torque (torque per unit volume) than conventional single-type motors by utilizing both radial and axial magnetic flux paths simultaneously.
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 hybrid motor design enhances torque production while maintaining a constant volume, improving efficiency and power factor compared to conventional induction motors.
Implementation Method 1
rotates the rotor by using a rotating magnetic field generated by a stator winding and an induced current generated by the rotating magnetic field
Data Source
AI summary
A hybrid motor includes a rotor, a radial stator facing the circumference of the rotor, and first and second axial stators facing both sides of the rotor. The rotor includes conduction bars arranged in radial and axial directions, corresponding to the radial stator and the axial stators, and end-rings electrically connecting the conduction bars.