Why does the DC Vibration Motor Make Noise?

Why does the DC vibration motor make noise?

The brushless DC vibration motor is a new type of vibration drive device that uses the eccentric blocks installed at both ends of the rotor of a special dual-shaft three-phase asynchronous motor to provide vibration force. It is widely used as the excitation source of various vibrating machinery (such as vibrating feeder, vibrating conveyor, vibrating screener, vibrating shakeout, vibrating crusher, vibrating hoist, vibrating test bench, etc.) Used as a warehouse wall vibrator (silo wall rapper).

Compared with other vibrators (such as electromagnetic vibrators and warehouse wall vibrators), brushless DC vibration motors have the advantages of small size, light weight, simple structure, convenient disassembly and assembly, large excitation force, low power, high efficiency and low noise. , High power factor, vibration force can be stepless adjustment and so on. Because of its convenient use and simple structure, micro vibration motors are widely used in mining, metallurgy, coal, building materials, chemical industry, light industry, electronics, machinery, food and other industries.

When the brushless DC vibration motor has mechanical vibration noise and abnormal bearing vibration noise during the operation, how should we analyze and solve it? The following ATO Vibration Motor will take you to analyze the reasons.

Unbalanced Vibration of Rotor of DC Vibration Motor

DC vibration motor

Cause: Residual imbalance during manufacture.

  • A large amount of dust adheres during long-term operation.
  • Thermal stress during operation causes shaft bending.
  • Thermal displacement of rotor fittings causes unbalanced loads.
  • The centrifugal force of the rotor fitting causes deformation or eccentricity.
  • External forces (belts, gears, poor straightness, etc.) cause the shaft to bend.
  • Poor bearing installation (shaft accuracy or locking) causes shaft bending or internal deformation of the bearing.


  • Suppresses rotor unbalance.
  • Maintain within the allowable unbalance amount.
  • Improvement of over-tightening of shaft and core.
  • Design improvements for thermal expansion anisotropy.
  • Improvements in strength design or assembly.
  • Correction of shaft strength design, change of type of shaft coupling and correction of direct connection to center.
  • The bearing end face and the shaft attachment section or the lock nut are prevented from being biased.

Abnormal vibration noise of bearing of DC vibration motor


  • A wound inside the bearing.
  • The axial direction of the bearing is abnormally vibrated, and the gas spring constant in the axial direction and the rotor mass constitute the excitation of the vibration system.
  • Friction noise: The cause of poor lubrication and bearing clearance of cylindrical rolling bearings or large-diameter high-speed ball bearings.


  • Replacement of bearings.
  • Appropriate axial direction gas spring preload to change the bearing clearance.
  • Select a soft grease or a grease with excellent low temperature properties, with a small residual gap (be careful about temperature rise).

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