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Have you ever encountered it? During the machining process of the CNC machining center, the spindle speed is abnormal, and the speed displayed by the system is unstable, sometimes fast and sometimes slow. Next, the Xiehe processing manufacturer will briefly introduce how to solve the abnormal speed of the spindle of the CNC machining center.

1. CNC machining center prepares for spindle maintenance

The spindle speed is abnormal, that is, after the spindle is given a speed command, the speed fed back from the CNC machining center machine tool is inconsistent with the commanded speed (generally it is less than the commanded speed) or the spindle does not rotate smoothly and has abnormal "squeaks" "The sound appeared, fast and slow, and in some cases, the motor may even have an overcurrent alarm. In the case of encoder feedback for the CNC machine tool spindle, the speed command "S" given by the CNC machining center machine tool is followed by a number, that is, the value fed back to the system display is consistent. The main drive of the main shaft can be driven by a belt or a gear. Now most of them are driven by a synchronous belt in the belt drive. If the speed is abnormal, it may be because the synchronous installation is too long, so the belt slips and loses steps. At the same time, the connection between the spindle and the spindle encoder also uses a timing belt, and there is also the possibility of losing steps in this link. However, the lubrication of the spindle is not good or any bearing on the spindle is burnt out, resulting in excessive resistance of the machine tool and making the spindle not rotate smoothly. External signal interference can also cause this phenomenon.

2. Pre-repair survey of CNC machining center.

The machining center is running in idling, only going in one direction or changing direction when the spindle is at low speed, the spindle speed is not obviously lost, but when the spindle axis is moving fast or cutting materials, especially at large cutting depths, the step is lost More obvious.

Three, analyze the reasons

1. The signal sent from the CNC machining center system to the spindle servo amplifier (frequency converter) is interfered during transmission,

2. The circuit voltage is unstable

3. The synchronous belt that transmits the drive to the main shaft is too long or wears to cause slippage

4. The synchronous belt connecting the main shaft and the main shaft encoder is too long or worn to cause slippage.

5. The signal line from the encoder to the servo amplifier or between systems is interfered by the outside of the signal.

6. The two sets of bearings supporting the main shaft burn out

7. The spindle of CNC machining center is poorly lubricated

4. Determine the steps to troubleshoot the spindle failure of the CNC machining center

1. Use a multimeter to measure the power voltage of the CNC machining center, and find that the voltage is normal, and other machine tools next to it work normally with the same power grid, then the cause of voltage instability can be ruled out

2. Check that the amount of lubricating oil in the machine tool of the CNC machining center is within the normal working range, the lubrication system is working normally, and there is no failure such as oil leakage and open circuit in the oil circuit, and eliminate the failure in lubrication

3. There is no problem with the lubrication. It may be caused by poor bearing movement. When the spindle of the CNC machining center is running, use a long rod (usually a screwdriver) to lean against the approximate position of the spindle box where the bearing is installed, and the other end (large one) One end) lean on the maintenance personnel's ear and listen to the sound of the bearing running. If there is no abnormal sound, the possibility of the fault caused by the bearing can be ruled out.

4. If there is no problem with the lubrication of the CNC machining center, the problem may be inside the spindle box. Open the inside of the spindle box and check the timing belt connection between the spindle motor and the spindle. Press the belt between the two pulleys with your hands to show that it is tight and suitable. .

5. There is no problem with the synchronous belt connection between the spindle CNC machining center motor and the main shaft. When checking the synchronous belt between the main shaft and the encoder, it is found that the synchronous belt has been severely worn. After replacing the new synchronous belt, the system shows that the spindle speed is normal. CNC machining center The spindle fault is removed.

The above content is how to solve the abnormal speed of the spindle of the cnc machining center. I hope it can be helpful to everyone. If you want to know more about cnc processing, please call the Xiehe processing manufacturer, we will serve you wholeheartedly.