Correct installation method of built-in encoder of Siemens Servo Motor
Correct installation method of built-in encoder of Siemens Servo Motor

1. This technology is applicable to the installation and commissioning of the built-in encoder of Siemens Servo Motor (models 1ft603-1ft613, 1fk604-1fk610) in Germany after damage. The configured incremental encoder is ern1387.001/020 of heidenham, Germany, and the absolute encoder is eqn1325.001 of heidenham. 2. Use a set of metric hexagonal wrench, a self-made special tool, a cross screwdriver and a slotted screwdriver, and a set of 6 Torx screwdrivers. 3. The problem that can be solved is to repair the faulty Siemens Servo motor or replace the damaged built-in encoder of the servo motor, so as to repair the old and make good use of the waste and save the maintenance cost.

2、 Operation method 1. The difference between this operation method and the general operation method. In the SIEMENS NC system configured for NC machine tool, the driving motor is divided into spindle motor and servo motor.

When the motor stator, rotor and bearing are faulty or the built-in encoder of the motor is damaged, we need to disassemble the encoder for repair or replacement. For the spindle motor, the replacement or installation of encoder can be tested as long as it is installed in the corresponding position with special tools, and there is no need to adjust the angle and position of motor shaft or encoder. However, for the servo motor, the installation steps must be strictly implemented according to the installation requirements of the encoder. As long as there is an error in the installation process, there will be an alarm in the encoder and the machine tool cannot be started or a flying accident will occur, resulting in the scrapping of the motor or the damage of mechanical parts. Therefore, proper installation is very important.

2. Operation steps of this technology

2.1 remove the damaged encoder, turn off the power supply of the machine tool, remove the power cable and feedback cable of the servo motor, remove the motor from the machine tool and put it on the workbench table, remove the four bolts on the motor end cover with an Allen wrench, open the end cover, remove the encoder cover first, pull out the plug-in cable on the encoder, and remove the two small screws on the support plate with a cross screwdriver, Remove the bolt in the center hole of the encoder with an Allen wrench, and then push the encoder out of the motor shaft with a self-made special tool. In this way, the first step is completed.

2.2 install the encoder ern1387.001/020 or eqn11325.001 of heidenham company. 2.2.1 first install the motors of different models of the support plate, and the shape of the support plate is also different, which is provided by the purchased spare parts. Install the support plate to the shaft end of the encoder with four M2.5 * 6 small screws. Note: ensure that the distance between the support disk surface and the bottom surface of the encoder is 5.2mm or 12mm. Fix the encoder -- for ern1387.001/020 encoder, use M5 * 50 bolt to fix it through the center hole -- for eqn1325.001 encoder, use M5 * 70 bolt to fix it through the center hole. Pay attention to proper force during fixing to prevent the encoder from rotating. Then install two screws for fixing the support plate, insert the power cord plug, cover the metal shell, ensure that the power cord is smoothly placed in the groove of the shell, make the shielding layer in good contact with the metal shell, and install the screws for fixing the shell. 2.2.6 after the encoder of the test motor is installed, install the motor end cover, connect the power cable and feedback cable of the motor on the workbench, and conduct the no-load test of the motor first. Power on the machine tool. After the standby bed starting mode group is ready, the test motor can be inched. If the motor can rotate normally without alarm and flying, it indicates that the encoder is installed successfully. Otherwise, it needs to be removed and reinstalled. If it is tested directly on the machine tool, the mechanical part of the machine tool will be seriously damaged in case of flying.

2.2.7 install the motor on the machine tool. After the no-load test of the motor, it can be installed on the machine tool, and then power on the test run to test its motion performance. Observe the motor current and load through parameters, understand the motion of the shaft with the motor, and adjust it at any time as needed. 3. Errors and problems needing attention in operation

First, when installing the support plate, ensure that the support plate surface is parallel to the bottom surface of the encoder, and pay attention to its spacing and tolerance range. Otherwise, it is easy to damage the support disc or encoder shaft during rotation.

Second, pay attention to the mark on the motor shaft, as shown in Figure 4. The direction of this mark varies with the motor model. For example, when I repaired 1ft608 motor, I didn‘t realize the importance of this mark at the beginning and didn‘t look at the mark on the motor shaft. As a result, there was a flying phenomenon when testing the motor after installation. I immediately pressed the emergency stop switch for emergency stop, so that the motor was not damaged.

Third, pay attention to the marks on the encoder. For ern1387.001/020 encoder, the marks on the glass disk and circuit board are clear and easy to adjust. For the encoder eqn11325.001, the mark on the gear is a small black spot. If the mark is aligned, there will be an alarm or flying car. The consequences of flying car are serious and must be paid enough attention. Common alarm contents include:

Fourth, the motor should be handled with care during disassembly and moving to prevent collision. In particular, the encoder must not be knocked with a hammer, otherwise it is easy to damage the optical elements inside the encoder and the holding brake device of the motor. Fifth, if it is a vertical axis motor, there is a holding brake device inside, so it is impossible to rotate the motor shaft by hand.

In this way, before adjusting the mark on the shaft, it is also necessary to connect a 24V DC power supply to the holding brake power terminal, and pay attention to the polarity to release the holding brake device. If the polarity of the power supply is reversed, the holding brake device will not be released. 4. How to master this skill? First of all, we should understand the structure and working principle of NC machine tool and the function and structural characteristics of servo motor. Second, we should understand the performance of the encoder, whether it is incremental or absolute. Have enough knowledge and understanding of the alarm content. When the machine tool alarm is encountered, the fault can be analyzed according to the alarm. Third, the installation process should be stable, accurate and light, so that the encoder can be correctly installed in the appropriate position.