DC motor in use, and some customers will respond to the phenomenon of vibration, do not know how to solve. Today we have from the mechanical and electrical reasons to understand the two reasons to understand the reasons and solutions.
First, the mechanical reasons
1, journal oval or shaft bending. When the DC motor rotates, due to the rotor gravity and produce interference vibration, the vibration frequency is usually double the motor operating frequency. The bending of the shaft causes an unbalanced weight to rotate at an angular velocity around the static equilibrium position, with the result being the same as the rotor imbalance. The crest of the journal or elliptical axis can be measured in the case of a dial indicator. The journal oval has to be welded or polished and polished. The shaft must be calibrated when it is bent.
2, armature imbalance. Due to the rotation of the imbalance caused by the quality of the role of centrifugal force, so that the role of the bearing has a rotating force, resulting in the motor and the basis of vibration. When the air gap is not uniform, the main pole is not tight or the base, the end of the rigidity of the poor, will cause vibration intensified, so check the rotor is not balanced, you must re-dynamic balance.
3, the base, the cover of important bearing manufacturing error or operating deformation. Due to the base, the end of the rotor and other important support parts of the mating surface error tolerance, especially large and medium-sized motor running for a long time after the base, cover and other important bearing deformation, so that the DC motor in the run-time bearing Interference, resulting in motor vibration.
4, bearing radial clearance is too large, the outer ring and the cover with the loose. In the assembly, the bearings should be qualified. Bearing and journal, bearing seat must meet the requirements, or to be sprayed or brushing process to deal with, to avoid poor bearing caused by vibration. For wear bearings, the motor running when the vibration noise frequency is higher, easier to judge, found that this situation should be replaced bearings;
Second, the electrical reason
1, air gap is not average. As the demolition of the air gap is not uniform, DC motor running unilateral magnetic pull, its role is equivalent to the motor shaft deflection add. Thus ensuring that air gap removal is an essential measure to avoid vibration.
2, the rotor coil is damaged. As the rotor coil damage to the motor when the rotor radial force is not uniform, the consequences and the rotor is not similar to the imbalance.
3, electromagnetic force. This kind of electromagnetic force is mainly caused by the longitudinal oscillation of the magnetic flux under the pole piece, usually has the tooth frequency, especially when the stator is also the opening groove, the magnetic flux is added, and the alternating magnetic magnetic force is more likely to form.
When the DC motor vibration problems, it should be timely to identify the reasons to eliminate the failure, so as not to affect the normal use, delay the work process. At the same time in the usual use should pay attention to do regular maintenance work.