When designing or evaluating motors, precision is everything. From robotics and drones to medical devices and electric vehicles, even the smallest irregularities in motor performance can translate into errors, vibrations, or reduced efficiency. One key factor behind these inconsistencies is cogging torque.
What is Cogging Torque?
Cogging torque is the unwanted, pulsating torque that occurs in permanent-magnet motors. It happens because of the attraction between the rotor magnets and the stator teeth.
Why Does It Matter for Precision?
Vibration and Noise – Uneven torque causes small but rapid changes in speed, which generate vibration and audible noise. In high-precision machinery, this can degrade performance and user experience.
Reduced Efficiency – Motors that suffer from cogging torque require extra current to overcome uneven torque, which can increase power consumption and heat generation.
Scaling Problems in Modern Motors – High-efficiency brushless motors now use strong magnets packed into compact designs. While this boosts power density, it also makes them more susceptible to cogging torque if not carefully managed.
Overcoming Cogging Torque with Sugawara’s Cogging Torque testing system:
High-Resolution Data for Deeper Insight
With an angular resolution as fine as 0.01° and up to 36,000 data points per revolution, engineers can map even the smallest torque ripples. This level of detail allows precise correlation between cogging torque and motor structural features like slot number, pole count, or magnet positioning.
Fast, Efficient Testing
Measurements can be completed in just 3 seconds at 20 rpm, making it practical for both R&D and quality control environments. Faster feedback means engineers can test more design iterations and identify effective solutions more quickly.
Advanced Analysis Tools
The included software supports:
• FFT analysis to identify frequency components of cogging torque.
• XY and polar plots for clear visualization of torque distribution.
• Multi-channel input (voltage, current, temperature) to analyze torque alongside other motor parameters.
Sugawara’s Cogging Torque Testing System doesn’t just measure cogging torque , it empowers engineers to overcome it. By turning invisible disturbances into visible, actionable data, the tester helps create motors that are quieter, smoother, and more precise.
