Solution to abnormal spindle speed of cnc machining center

Author: MULAN - Plastic Molding Manufacturer

Have you ever encountered it? The CNC machining center equipped with FANUCOI, during the machining process, the spindle speed is abnormal, and the speed displayed by the system is unstable, sometimes fast and sometimes slow. Precision Technology is committed to cnc ultra-precision machining with eighteen years of experience, and we will share effective solutions for you. First, the CNC machining center prepares for spindle maintenance before 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 manifested as less than the commanded speed) or the spindle rotates It does not start smoothly and there are abnormal "squeak" sounds, which are fast and slow, and in some cases, the motor may even have an over-current 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 (inverter) is interfered during the transmission process, 2. The circuit voltage is unstable 3. The timing belt that transmits the motion to the spindle is too long or 4. The synchronous belt connecting the main shaft and the main shaft encoder is too long or wears to cause sliding. 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 spindle burn out. 7. The spindle of the CNC machining center is poorly lubricated. 4. Determine the steps to troubleshoot the spindle of the CNC CNC machining center. 2. Check that the amount of lubricating oil of the CNC machining center machine tool 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. Eliminate lubrication problems 3. There is no problem with 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. , one end (the big one) leans against the ear of the maintenance personnel, and listens 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 synchronous 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.