Tangential Motor Rotor Core Layout for Lower Harmonic Noise
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Solution Overview
Problem
Tangential permanent magnet synchronous motors suffer from high vibration noise and harmonic distortion due to non-uniform air-gap flux density and back electromotive force, which limits their application and promotion.
Innovation Solution
A tangential motor rotor with a rotor core featuring magnetic isolation holes and bridges, designed to improve magnetic flux direction and air-gap flux density waveform, reducing harmonic ratios and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If slotting is provided on the stator to enable motor operation, then the motor can function, but the magnetic path becomes non-uniform causing high harmonic distortion and vibration noise
Solution Approach 1:
Magnetic isolation holes are introduced as intermediary elements between adjacent magnetic steel grooves in the rotor. These holes act as mediators that block the interaction of magnetic flux between adjacent poles, thereby eliminating the harmful harmonic waves generated by slotting while maintaining normal motor operation
Solution Approach 2:
The width of magnetic isolation holes is designed to vary along the radial direction, being smaller near the rotor center and larger near the outer periphery. This parameter change optimizes the magnetic isolation effect at different radial positions, effectively reducing harmonic distortion and vibration noise while preserving motor functionality
2Power
If tangential magnetization is used to achieve magnetism gathering effect, then air-gap flux density increases, but spatial harmonics are generated causing poor waveform quality
Solution Approach 1:
Magnetic isolation holes serve as intermediary structures that prevent the interaction of spatial harmonics between adjacent magnetic poles. By blocking the magnetic flux interaction paths, these holes eliminate low-order force waves while maintaining the high air-gap flux density characteristic of tangential magnetization
Solution Approach 2:
Magnetic isolation holes are selectively positioned between adjacent magnetic steel grooves where harmonic interaction occurs most strongly. This localized quality improvement targets the specific regions where waveform distortion is most problematic, effectively enhancing overall waveform quality without compromising the magnetism gathering effect
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 enhances torque stability, reduces vibration noise, and improves motor efficiency by optimizing magnetic flux distribution and harmonic loss.
Implementation Method 1
the magnetic flux direction of the rotor magnetic pole is effectively improved, the sine degree of the air-gap flux density and back electromotive force waveforms is improved, the harmonic ratio and the harmonic loss are reduced
Data Source
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AI summary
A tangential motor, a tangential motor rotor and a rotor core thereof are provided. The rotor core includes a rotor body (1) and magnetic steel grooves (2) provided on the rotor body (1). 2N magnetic isolation holes (11) are provided in a rotor magnetic pole between every two adjacent magnetic steel grooves (2). The 2N magnetic isolation holes (11) are symmetrically provided at two sides of a magnetic pole center line of the rotor magnetic pole. A width of each of the magnetic isolation holes (11) increases from a circle center of the rotor body (1) to an outer side of the rotor body. Outer side hole surfaces, close to the outer side of the rotor body (1), of the magnetic isolation holes (11) are arc-shaped surfaces which are concentrically arranged with the rotor body (1). The rotor core is able to reduce the vibration noise of the motor and increase the efficiency of the motor.