Electric spindle is a precision and high-speed electromechanical integrated product, involving multiple technologies such as mechanical, electrical control, lubrication, cooling, vibration, materials, and heat treatment. Especially in the bearing industry, the electric spindle is the core component of grinding machines, etc. If there is a malfunction during the production process, it will not only seriously affect production, but may also cause damage to related equipment. Timely detection of various faults in the electric spindle and taking effective solutions are essential tasks in production.

Common faults and solutions, high noise and vibration, cause analysis, improper assembly of the spindle leading to damage to bearings or other parts, low bearing accuracy or poor holding force, poor coaxiality between the stator and rotor, uneven air gap between the stator and rotor, low manufacturing accuracy of spindle parts or deformation and loss of balance accuracy after long-term use, insufficient preload or spring not installed in place or even broken, rotor cage bar fracture or poor contact, poor rigidity and accuracy of the grinding wheel connecting rod.

Solution: Select the best bearings, calibrate the coaxiality of the stator and rotor, check the accuracy of the main parts such as the casing, shaft, rotor, and cover, increase the preload force, reassemble the electric spindle, select a rigid and high-precision grinding wheel connecting rod, and ensure the normal and stable operation of the electric spindle.

Analysis of the reasons for the difficulty in starting the electric spindle: inability to plug in the power plug, poor or unconnected contact, insufficient power supply or mismatch with the electric spindle, failure to adjust the inverter start protection to the optimal value, power phase loss or poor contact of the contactor, etc., all of which can cause difficulties in starting the electric spindle. The excessive preload applied to the bearings in the electric spindle and the mutual friction between the parts can also cause difficulty in starting, but in most cases, the reason for the difficulty in starting is: incorrect connection of the motor stator lead wire in the electric spindle, small air gap between the stator and rotor, and damaged stator winding.

The solution is to first check the power supply voltage, current, and power, check if the power supply is normal, readjust the frequency converter according to the electrical parameters of the electric spindle, and then check the insulation of the stator winding to ground and the balance status of the three-phase winding. Once a fault is found, repair it immediately. If the air gap between the stator and rotor is too small, grind the outer diameter of the rotor to maintain the design value of the gap between the stator and rotor. If there is friction between parts, grind the outer diameter of the parts to ensure sufficient clearance between them. The starting conditions of the electric spindle can also be improved by modifying the given preload value. Therefore, when the electric spindle is difficult to start, specific solutions should be found for the equipment.

Poor machining accuracy, cause analysis, low bearing accuracy, poor spindle accuracy, loss of spindle accuracy due to human damage or long-term work, loose fit between front bearing seat and bearing, insufficient preload or parts stuck, loose front and rear nuts, shaft movement, poor quality of grinding wheel connecting rod. Solution: Select the better bearings, reassemble them, coat the seat holes and spindle with hard chrome, and grind them again to the required accuracy. Increase the pre tightening force, lock the front and rear nuts, and tighten them with locking screws. Choose a grinding wheel connecting rod with good rigidity and high accuracy.

Deceleration or unstable speed, cause analysis, low power supply voltage, mismatch with electrical parameters, low power, rotor cage bar fracture or poor contact. Solution: First, check whether the output power, frequency, voltage, and power match the electric spindle. If the electric spindle power is too low, choose a higher power electric spindle that meets the working conditions, check the quality of the cage bars, and choose an electric spindle with a larger capacity.