Causes and solutions of AC servo motor failures

Nowadays, with the rapid development of the technology industry, AC servo motors are gradually appearing in various industries, and AC servo motors have a wide range of applications. They can not only be used for material measurement and horizontal sealing equipment, but also for feeding materials. However, after long-term operation of the AC servo motor, various faults will occur. At this time, we should promptly determine the cause of the fault and then handle it accordingly. Timely judgment and processing are important to avoid the expansion of the fault and ensure the normal operation of the equipment. Operation. The following is a detailed introduction to the causes and solutions of AC servo motor failures. I hope it can help everyone solve their problems!

1. The AC servo motor cannot rotate after power is supplied, but there is no abnormal sound, odor or smoke.

1. Reasons for the failure: ① The power supply is not connected (at least two phases are not connected); ② The fuse is blown (at least two phases are blown); ③ The overcurrent relay is adjusted too small; ④ The control equipment is wired incorrectly.

2. Troubleshooting: ① Check the power circuit switch, and check whether there are breakpoints in the fuse and junction box, and then repair it; ② Check the fuse type and cause of the fuse, and replace it with a new one; ③ Adjust the relay setting value and the motor Cooperate; ④ Correct the wiring.

2. The motor does not rotate and makes a buzzing sound after power is supplied.

1. Reasons for the failure: ① The rotor winding has an open circuit (one phase is disconnected) or one phase of the power supply loses power; ② The beginning and end of the winding wire is wrongly connected or the internal connection of the winding is reversed; ③ The contacts of the power circuit are loose and the contact resistance is large; ④ The motor The load is too large or the rotor is stuck; ⑤The power supply voltage is too low; ⑥The small motor is installed too tightly or the grease in the bearing is too hard; ⑦The bearing is stuck.

2. Troubleshooting: ① Identify the breakpoint and repair it; ② Check the winding polarity to determine whether the winding ends are correct; ③ Tighten the loose wiring screws, use a multimeter to determine whether each joint is falsely connected, and correct it; ④ Reduce load or check Find and eliminate mechanical faults; ⑤ Check whether the specified surface connection method is mistakenly connected, and whether the voltage drop is too large because the power wire is too thin, and correct it; ⑥ Reinstall it to make it flexible and replace it with qualified grease; ⑦ Repair the bearing.

3. It is difficult to start the motor. When there is an extra load, the motor speed is much lower than the extra speed.

1. Reasons for the failure: ① The power supply voltage is too low; ② The surface connection method of the motor is incorrectly connected; ③ The rotor is open or broken; ④ Some coils of the rotor are connected incorrectly or reversely; ⑤ The number of turns is increased too much when repairing the motor winding; ⑥ The motor is overloaded.

2. Troubleshooting: ① Measure the power supply voltage and try to improve it; ② Correct the connection method; ③ Check the open welding and break points and repair them; ④ Find the wrong connection and correct it; ⑤ Restore the correct number of turns; ⑥ Reduce load.

4. The no-load current of the motor is unbalanced and the three-phase phase difference is large.

1. Reasons for the fault: ① The and end of the winding are connected incorrectly; ② The power supply voltage is unbalanced; ③ The winding has faults such as inter-turn short circuit and reverse connection of the coil.

2. Troubleshooting: ① Check and correct; ② Measure the power supply voltage and try to eliminate the imbalance; ③ Eliminate winding faults.

5. The motor makes abnormal noises when running.

1. Reasons for failure: ① The bearing is worn or there are foreign objects such as sand in the oil; ② The rotor core is loose; ③ The bearing is short of oil; ④ The power supply voltage is too high or unbalanced.

2. Troubleshooting: ① Replace the bearing or clean the bearing; ② Inspect the rotor core; ③ Add oil; ④ Check and adjust the power supply voltage.

6. The motor oscillates greatly during operation.

1. Causes of failure: ① Due to wear and tear, the bearing gap is too large; ② The air gap is uneven; ③ The rotor is unbalanced; ④ The rotating shaft is bent; ⑤ The coaxiality of the coupling (pulley) is too low.

2. Troubleshooting: ① Inspect the bearings and replace them if necessary; ② Adjust the air gap to make it uniform; ③ Check the dynamic balance of the rotor; ④ Straighten the rotating shaft; ⑤ Re-calibrate to make it comply with the regulations.

7. Bearing overheating

1. Reasons for failure: ① Too much or too little grease; ② Poor oil quality and containing impurities; ③ Improper coordination between the bearing and the journal or end cover (too loose or too tight); ④ The inner hole of the bearing is eccentric and opposite to the shaft. ⑤ The motor end cover or bearing cover is not installed flatly; ⑥ The coupling between the motor and the load is not calibrated, or the belt is too tight; ⑦ The bearing gap is too large or too small; ⑧ The motor shaft is bent.

2. Troubleshooting: ①Add grease according to the corresponding regulations (1/3-2/3 of the volume); ②Replace clean grease; ③If it is too loose, it can be repaired with adhesive; if it is too tight, the journal should be ground or ④Repair the bearing cap to eliminate friction spots; ⑤Reinstall; ⑥Recalibrate and adjust the belt tension; ⑦Replace new bearings; ⑧Calibrate the motor shaft or replace the rotor.

8. AC servo motor overheats or even smokes

1. Reasons for the failure: ① The power supply voltage is too high; ② The power supply voltage is too low, and the motor is running with an extra load, and the current is too high to cause the winding to heat up; ③ When repairing and removing the winding, the hot removal method is inappropriate and the iron core is burned; ④ AC servo The motor is overloaded or starts frequently; ⑤ The motor is missing a phase and runs in two phases; ⑥ The winding is not sufficiently impregnated with paint after rewinding; ⑦ The ambient temperature is high and there is a lot of dirt on the surface of the motor, or the ventilation duct is blocked.

2. Troubleshooting: ① Reduce the power supply voltage (such as adjusting the power supply transformer tap); ② Increase the power supply voltage or replace the thick power supply wire; ③ Inspect the iron core and solve the fault; ④ Reduce load and control starting according to the prescribed number of times; ⑤ Restore three-phase Operation; ⑥ Use secondary dipping and vacuum dipping processes; ⑦ Clean the motor, improve the ambient temperature, and adopt cooling methods.