Have you ever met? During the process of machining, the spindle speed of the CNC machining center supporting fanucoi is abnormal, the speed displayed by the system is unstable, fast slow. Precision technology is committed to CNC ultra precision machining with 18 years of experience, we share effective solutions for you.

1、 Preparation of CNC machining center for spindle maintenance

The main shaft speed is abnormal, that is, after the given speed command, the speed fed back the CNC machining center machine tool is inconsistent with the speed of the command (generally less than the command speed), the main shaft does rotate smoothly with abnormal "squeaking" sound, fast slow, in some cases, the motor may even have overcurrent alarm. When the spindle of CNC machine tool has encoder feedback, the speed instruction "s" given by CNC 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 belt drive gear drive. Now most of the main drives are synchronous belt drive in belt drive. The rotating speed is abnormal. It may be because the synchronous installation is too long, so the belt slips loses step. At the same time, the connection between the spindle the spindle encoder also uses a synchronous belt, which may also cause step loss in this link. However, the lubrication of the spindle is good any bearing on the spindle is burnt out, which results in the excessive resistance of the machine tool the spindle does rotate smoothly. external signal intervention can also cause this phenomenon.

Two. Pre processing investigation of CNC machining center.

When the machining center is idling, only going in one direction reversing at the low speed of the spindle, the step loss of the spindle speed is obvious, but the step loss is more obvious when the spindle is fast moving cutting materials, especially when the cutting depth is large.

3、 Analyze the cause

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

2. Unstable circuit voltage

3. Too long worn synchronous belt for transmission of motor to main shaft causes sliding

4. The synchronous belt connecting the spindle the spindle encoder is too long worn, resulting in sliding.

5. The signal line the encoder to the servo amplifier system is blocked by the external signal.

6. Two sets of bearings supporting the main shaft are burnt out

7. The spindle of CNC machining center is poorly lubricated

4、 Determine the steps check the spindle fault of CNC machining center

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

2. Check that the lubricating oil quantity of CNC machine tool is within the normal working range, the lubricating system is working normally, the oil circuit is free of oil leakage, open circuit other faults, remove the lubrication faults

3. There is no problem in lubrication, which may be caused by poor bearing movement. When the main shaft of CNC machining center is running, use a long rod (usually a screwdriver) to lean one end against the approximate position of the main shaft box to install the bearing, lean the other end (the big end) against the ear of the maintenance personnel to listen to the sound of the bearing running. If there is no abnormal sound, the possibility of bearing causing the fault can be eliminated.

4. If there is no problem in the lubrication of CNC machining center, the problem may be in the inner part of the main spindle box. Open the inner part of the main spindle box, check the synchronous belt connection between the main spindle motor the main spindle, press the belt between the two pulleys by hand to show proper tightness.

5. There is no problem in the connection of the synchronous belt between the motor the spindle of the spindle CNC machining center. When checking the synchronous belt between the spindle the encoder, it is found that the synchronous belt has been seriously worn. After the new synchronous belt is replaced, the system shows that the spindle speed is normal, the spindle fault of the CNC machining center is removed.