Excessive Unbalance after Motor Magnet Bonding? Check Adhesive Distribution and Runout First
When excessive unbalance, rising vibration or abnormal noise occurs on motor rotors after magnet bonding, priority shall be given to checking magnet mass distribution, bond-line thickness, circumferential squeeze-out, rotor concentricity and cured assembly position, instead of immediately concluding insufficient structural bond strength. For robot joint motors, industrial servo motors and high-speed brushless motors, magnet bonding must deliver structural reliability while preventing mass distribution changes caused by inconsistent adhesive dosage and assembly deviation. Permanent magnet motor rotors generally consist of rotor core, magnets, shaft and required retention features. Once magnets are installed with adhesives or hybrid fastening methods, bond-line thickness and magnet placement affect rotor geometry, and local adhesive variation alters rotating mass distribution. Therefore, acceptable bonding and acceptable dynamic balance…
