Firstly, Causes and countermeasures of the mechanical vibration motor rotor unbalance motor vibration A Cause: manufacturing residual imbalance. Long period of operation to produce a lot of dust adhesion. Operation caused by thermal stress axis bending. Accessories thermal displacement of the rotor caused by unbalanced load. Deformation caused by the centrifugal force of the rotor accessories or eccentric. Caused by external force (belt, gear, Direct bad) shaft bending. Poor bearing device (axis accuracy or locking) caused by the deformation of the shaft bending or bearing internal. B, responses: inhibition of the amount of rotor imbalance. Maintenance to allow the amount of unbalance within. Excessive tight fit on the shaft and the core to improve. Anisotropic thermal expansion, design improvement. ? Strength improvement of the design or assembly. Amendment to change the type of shaft coupling shaft strength design and straight junction towards the center of correction. End bearings and shaft attached segment or in the lock nut to prevent biased against. 2, the bearing of abnormal motor vibration motor vibration noise A Cause: Bearing internal injuries. Abnormal motor vibration in the axial direction of the bearing, shaft direction of the spring constant and the mass of the rotor the motor vibration excitation of the system. Fricative: cylindrical roller bearing or large-diameter high-speed ball bearings poor lubrication and cause of the bearing clearance. B, responses: the replacement of the bearings. The appropriate axis direction spring preload to the bearing clearance changes. Select soft grease or excellent low temperature grease, residual gap (should be noted that the problem of temperature rise). 3, brush sliding sound A Cause: The commutator and brushes sliding vibration motor brush holder excitation generated B, responses: grip brush elastic support, select the material and shape of the brush, curb side pressure caused by The brush motor vibration and to improve the commutator accuracy.

    Second, The fluid motor vibration noise generation and Countermeasures motor fluid motor vibration noise, mainly caused by the cooling fan motor vibration noise. In addition, part of the groove opening portion of the rotor core close to the stationary side, becomes significant gas beep Furthermore the ventilation path, such as a resonance space, and produce significant resonance. 1, the size of the vibration and noise of the fan motor: the motor is generally seeking rotation in two directions, fan blades for radial straight blade, poor efficiency, and motor vibration noise. Motor vibration and noise values approximately by the following formula requirements. But the determination of the motor shaft center height from 1m situation. The motor vibration noise dB (A) = 70 log D +50 Log N + D: outer diameter of the blade (m), N: DPS of the number of revolutions: at constant 32 to 36, by the above formula, reduced motor vibration and noise level, more important to reduce the outer diameter of the fan. Spit out the air volume and air pressure is low, these complexes becomes important. Fan in the inside of the frame, the effect of the noise reduction or sound insulation. 2, the frequency of the vibration and noise of the fan motor depending on the different types of differences. Pressure motor vibration and noise, the fan blades air under pressure shock. The spoiler noise, as the the blade surrounding air flow disturbance causes of radial linear blade fan, can be said on the use of the motor is inevitable. The fan with the remaining part of the interference caused by the gas beep turning vane, in order to close the presence of other parts such as air flow, generating intense gas beep.

     Three, electromagnetic motor vibration noise (induction motor) about electromagnetic motor vibration noise, vibration noise of the electromagnetic motor by ear sense of hearing sense of the degree of good frequency more than 100HZ frequency with a domain, a single or plural specific frequency tone composition, especially with the stator resonance become a significant motor vibration and noise. The induction motor than the DC motor often electromagnetic motor vibration and noise problems, induction motor instructions. The electromagnetic motor vibration and noise induction motor known as "magnetic tone" of such research, we must first understand the the electromagnetic motor vibration and noise of the sinusoidal current. 1, the sine wave current of the electromagnetic motor vibration noise: the magnetic flux generated due to the sine-wave current, the magnetic flux generated by the air gap of the induction motor, and torque of the basic (primary), the presence of the high harmonic flux. Electromagnetic force waves these magnetic flux of the stator and the rotor core to attract each other, the stator core is deformed into a polygonal shaft bending displacement generating motor vibration. High harmonic flux, by reason mainly generate electromagnetic noise of the air gap, A, the winding distribution caused by the magnetic force of the higher harmonics. B, the stator or the rotor iron trough grooves generated higher harmonics. C, core saturation saturated high harmonics. D, caused by eccentric eccentric harmonic E, voltage coil, the magnetic circuit imbalance caused by the high harmonics. F, slot the high permeability harmonic. G, with high harmonics, the air gap in the amount of time a lot of space harmonic magnetic power waveform distortion caused by high harmonic flux. Electromagnetic motor vibration noise prevention measures: A. by the appropriate combination of the number of slots in the motor design using the special slot chute select the coil pitch sine wave winding fractional slot winding air gap, teeth, yoke flux density by the mechanical design, the appropriateness of the Ministry of rotor slot pole thickness equalization magnetic air gap wedge expansion B. eliminate static eccentricity, and improve the accuracy of processing and assembly. The external force to improve the flexural rigidity of the shaft assembly precision. Fully closed slot type to eliminate the thickness of the tooth tip, to improve the manufacturing technology. The magnetic circuit so as not to cause the cross-sectional shape of the unbalanced structure and the manufacturing the special rotor resistance of the conductor, an insulating or shaft. A stator, a rotor to avoid the resonance of the motor constituting part materials. To avoid resonance with motor assembly. The stator core or the elasticity of the bearing supporting portion, the vibration isolating support. By the exterior of the motor sound insulation or sound-proof structure. C. In use, the supply voltage to eliminate the imbalance. Electromagnetic motor vibration and noise reasons into electromagnetic excitation force, these high harmonic flux due to mutual interference caused by electromagnetic force generated wave. But not all motor vibration motor noise problem by the electromagnetic force wave caused. Some of which are consistent with the stator or the rotor of the natural vibration motor or close the case to form a resonance state. Electromagnetic motor vibration and noise factors, not solely because of the frequency of the electromagnetic force waves, we also need to understand the motor part of the the motor vibrating body natural motor vibration frequency.