How to diagnose and repair faults in Siemens servo motors

Shanghai Quli Automation Technology Co., Ltd.: Siemens CNC system servo motor maintenance is a complex technical service industry. In recent years, servo motors have been used more and more widely, and the use of the market in Chinese Mainland has increased rapidly. The demand for technical services such as spindle motor maintenance has become increasingly urgent. Due to the fact that most of the servo motors used in China are imported products with high technological content, foreign servo motor manufacturers have adopted non-standard encoders or installation methods in order to monopolize the maintenance service market, making spindle motor maintenance more difficult and forming servo motor maintenance as an outstanding technical skill.

Siemens servo motor maintenance and repair includes wear of water brake pads, normal high-speed deviation at low speed, normal low-speed deviation at high speed, startup alarm, startup trip, overload, overvoltage, overcurrent, inability to start, weak startup, shaking during operation, demagnetization, displacement, deviation, unbalanced output, encoder alarm, encoder damage, inaccurate position, and movement. Once these physical data are obtained, an alarm voltage meter will be triggered to check the input terminal power supply voltage, two currents, and three-phase unbalanced motor fault cause.

How to diagnose and repair faults in Siemens servo motors

1. The power supply voltage is severely insufficient.

2. Regardless of which type of servo motor it is, over time, it will cause some minor problems.

Today, we will bring you some common motor malfunction symptoms. When there are minor problems with the servo motor, it is not only necessary to detect them in a timely manner, but also to find the cause of these faults. Only then can the servo motor repairman prescribe the right medicine and repair the servo motor. The effective value is 362A, which is 2.7 times the rated current, with a starting time of 28 seconds. The peak to peak value of the large starting current of the B air supply motor is about 1336A, and the effective value is 472A. Through the interaction with the rotating magnetic field of the rotor, a positive drag torque is generated, which reduces the active power absorbed by the motor from the grid. The active current of the main winding changes proportionally with the speed of the circuit and other equipment. For low-voltage motors below 500 volts, electromagnetic instantaneous release devices such as fuses or circuit breakers are generally used for short-circuit protection.

3. Overload protection. For the overload current of the electric motor, fuses may not necessarily be able to cut off the circuit. Therefore, a special protection device should be set up to cut off the overload current. When the motor is overloaded by 20%, the thermal relay will operate within 20 minutes to cut off the power supply. In general, motor overload protection uses thermal relays or circuit breakers with thermal release devices. (4) Phase failure operation protection. Phase loss operation protection is also a type of overload protection. The current of the winding that is not disconnected increases rapidly, causing the winding of this phase to burn out due to excessive temperature rise. Therefore, phase failure protection is generally installed in the control circuit of electric motors. Protection for three-phase asynchronous motors operating in phase loss (1) Proper selection of melt capacity and installation of melt. Under normal circumstances, the formula for the rated current of the melt is: rated current=K × rated current of the motor. Generally, for fuses with larger heat resistance capacity, the K value is taken as 1.5-2.5.

Before maintenance, understand the working principle of the servo motor:How to diagnose and repair faults in Siemens servo motors
1. A servo system is an automatic control system that enables the output controlled variables such as the position, orientation, and state of an object to follow any changes in the input target (or given value). Servo mainly relies on pulses for positioning. Basically, it can be understood that when a servo motor receives one pulse, it will rotate the corresponding angle of one pulse, thereby achieving displacement.

2. AC servo motors are also brushless motors, divided into synchronous and asynchronous motors. Currently, synchronous motors are generally used in motion control, which have a large power range and can achieve high power.

3. The rotor inside the servo motor is a permanent magnet, and the U/V/W three-phase electricity controlled by the driver forms an electromagnetic field. The rotor rotates under the action of this magnetic field. At the same time, the encoder provided by the motor feeds back the signal to the driver, and the driver compares the feedback value with the target value to adjust the angle of rotor rotation.

Asynchronous motor, synchronous motor.

2.1 Synchronous motors can be divided into permanent magnet synchronous motors, reluctance synchronous motors, and hysteresis synchronous motors.

2.2 Asynchronous motors can be divided into induction motors and AC commutator motors. The positioning controller has two (2) threaded connectors to SSBSM50/63/80 for feedback and motor termination. Stop, therefore a mechanical brake must be applied to maintain the megahertz component in the working mode of the motor shaft. What are the types of motors? 1. Divided by the type of working power supply: they can be divided into DC motors and AC motors.

1.1 DC motors can be divided into brushless DC motors and brushed DC motors according to their structure and working principle.

1.1.1 Brushed DC motors can be divided into permanent magnet DC motors and electromagnetic DC motors. Protection improvement (time=0 in Figure 6).

1.1.1.1 Classification of Electromagnetic DC Motors: Series excited DC motors.

2.2.1 Induction motors can be divided into: three-phase asynchronous motors for household appliances (including washing machine constant speed motors). If several or one parallel branch is disconnected, it can be difficult to check. In such cases, the phase current balance method or resistance method are usually used. The resistance method uses a bridge to measure the resistance of the three-phase winding. If the three-phase resistance differs by more than 5%, the phase with higher resistance is the open circuit phase, and the motor speed and sound are normal.

Scope of servo motor maintenance service faults:

Repair faults: magnet explosion, magnet detachment, stuck rotation, encoder wear, code/glass disc wear and tear, motor overheating, motor water ingress, motor abnormal operation, high-speed operation noise, loud noise, brake failure, brake pad wear, low-speed normal high-speed deviation, high-speed normal low-speed deviation, start alarm, start trip, overload, overvoltage, overcurrent, unable to start, weak start, running shaking, demagnetization, running position, running deviation, output imbalance, encoder alarm, encoder damage, position deviation