YZR/YZ Type Motors Disassembly Step
We all know, because the YZR / YZ motor current is too large, the power supply voltage is too large, single-phase operation, mechanical bumps, poor manufacturing caused by insulation damage to the three-phase motor sub-winding inter-turn short circuit, Short-circuit between windings and short-circuit windings.
For this phenomenon, we have to look at several kinds of inspection methods:
⑴ external observation method. Observe the junction box, winding at the end of whether the burning, winding overheating left dark brown, and smell.
⑵ temperature test method. No-load operation for 20 minutes (found abnormal should immediately stop), the back of the wrist with the back of the parts are more than the normal temperature.
⑶ power test method. Measured with ammeter, if a phase current is too large, indicating that the phase has a short circuit.
⑷ bridge inspection. Measuring a winding DC resistance, the general difference should not exceed 5%, such as more than, then the resistance of a small phase fault.
⑸ short-circuit detectors method. The measured winding has a short circuit, then the steel will produce vibration.
⑹ multimeter or megger method. Measure the insulation resistance of any two-phase winding, if the reading is very small or zero, indicating that the two-phase winding phase short circuit.
⑺ voltage drop method. The three windings in series after the access to low-voltage safe AC, measured a small group of small short-circuit fault.
⑻ current method. Motor no-load operation, the first measurement of three-phase current, in the exchange of two-phase measurement and comparison, if not with the power exchange and change, the larger current phase winding has a short circuit.
Life, we encountered YZR / YZ-type motor bad time, want to disassemble, how to do it?
(A) first remove the motor's external wiring, and do the mark, for example, for the asynchronous motor, should do a good job with the three-phase power line corresponding to the mark, for the DC motor, should be done shunt winding, armature winding External wiring corresponding to the mark. Then loosen the foot screw and separate the motor from the drive mechanism.
(B) With the tools shown to remove the pulley or coupling on the motor shaft, it is sometimes necessary to add some kerosene to the gap between the motor shafts of the pulley, so that it is permeable and lubricated for easy disassembly. Some shafts and wheels with a tight, but also need to quickly heat the wheel (while wet cloth wrapped around the shaft), in order to remove the wheel.
(3) For motors equipped with rolling bearings, remove the bearing cover and release the fastening screws of the end caps and mark them at the ends of the end caps and the housing The mark should not be the same), screw the unloaded fastening cap screw into the two screw holes that are specifically provided on the motor cover to eject the end cap. If you do not have this screw, you can only use the chisel (also called flat shovel) and hammer to knock the end cap and the seat of the seams, the end cover from the base to unload. Such as the cover is heavy, the application of lifting equipment hanging end cover, and gradually removed.
(D) the removal of the motor with a brush, the brush should be removed from the brush grip, to the DC motor, but also the location of the brush neutral line mark.
5) out of the rotor, we must pay attention not to hurt the stator coil, the rotor is not the weight, can be hand out; heavy weight, it should be used to lift the lifting equipment, the first two sets of rotor shaft Wire rope with lifting equipment to hold the rotor, slowly out, pay attention to prevent the collision coil. And then in the end of the shaft with a steel pipe, in order not to scratch the journal steel pipe, steel pipe can be a layer of thick cardboard to continue to move out of the rotor, until the rotor center of gravity has been moved to the stator, the rotor shaft Under the pad of a bracket, the wire rope in the middle of the rotor, you can pull out all the rotor.