Struggling with magnetic rotor problems, such as cogging torque, noise, and vibration?
Small asymmetries and misalignment of magnets can cause those issues. Hence, it is crucial to evaluate the full magnetic field distribution with sufficient spatial resolution. Magcam's advanced measurement systems enable the measurement, and analysis of many quality parameters of permanent magnet rotors, including, among others, cogging torque, skewing angles, THD, FFT, pole size analysis, zero crossings, and pole peak analysis.
The full magnetic field distribution (radial, tangential, and axial) on the entire rotor's surface can be measured in a few seconds at close distances. This allows the instant detection of common magnetic issues such as pole angle deviations and pole peak inhomogeneity.
MagScope software makes it easier than ever to measure the skewing angle of skewed permanent magnet rotors, enabling the detection of skewing angle deviations. The right figure shows an example of the step skew on an IPM (Interior Permanent Magnet) rotor, represented in a cross-section graph with automatic zero-crossing detection as well as pole angle, and peak values measurement.
From a bare rotor measurement, Magcam's advanced measurement systems can measure the magnetic field distribution with high resolution at close distances. These systems can derive quantitative harmonic ratios and calculate qualitative cogging torque curves. The visualized curves offer insight into cogging torque quality.
Hence, faulty PM rotors can be screened out before full stator assembly, saving valuable time and cost, and improving PM motor yield.
The Fourier spectrum reveals high harmonics in the magnetic field distribution of rotors. Highly dominant harmonics can be related to noise issues at the motor level. Fourier analysis offers insights into the contributions of unwanted harmonics, enabling the detection of noise and vibration sources in the rotor.
Magnetic rotary encoders are commonly used in angular encoders, e.g., electric motors and rotary positioning systems. The accurate feedback loop of the magnetic encoder is important to provide correct excitation to the motor and increase its efficiency. Therefore, it is crucial to measure the zero crossings and pole peaks in these applications and analyze the peak homogeneity, Fourier harmonics, and THD.
Linear encoders are typically used to measure distance and to infer linear position. In this application, it is important to accurately measure pole angles, to detect pole peaks and zero crossings.
For this application, the Bz component of the magnetic field is relevant. The MiniCube 3D magnetic field camera instantly measures the Bz field distribution. It provides analyses of the field homogeneity, the magnetization vector size, the angle deviation, and the deviations compared with a perfect theoretical magnet.
The MagFit module in our MagScope software allows you to measure and analyze the magnetization magnitude and the magnetization vector angle deviation of the dipole position sensor magnets. Moreover, this data analysis software can detect the north-south asymmetry, zero crossing, and deviations from the perfect theoretical magnet.
Would you like to measure and analyze your permanent magnets? We have an expert team ready to provide you with the best possible measurement solutions.