When you encounter FANUC spindle drive failure, do you know how to deal with it?

FANUC spindle drive maintenance problems mainly appear as stalls, abnormal speeds, motor oscillations, jitter during processing, and main circuit overcurrent alarms. Compared with AC FANUC spindle drive maintenance problems, the primary manifestations are motor overvoltage, fuse blown, etc. The primary cause of such drive maintenance servo problems is the overload of the servo motor, poor contact of the drive or damage to the cooling device. The impedance of the internal components of the driver is too high or the surge absorber of the CNC machine tool is faulty.

FANUC spindle drive failure, FANUC Servo Drive Repair

FANUC spindle drive common faults and drive repair and treatment methods: First, when the spindle drive is faulty, it is necessary to confirm the type and orientation of the spindle drive. When the servo motor is not working, it is first necessary to confirm whether the drive system has a signal output, and then to repair and test the drive. The second most important thing is to observe the condition of the drive's I/O board and confirm whether it is satisfied with the starting conditions of the spindle drive. If the servo motor is equipped with an electromagnetic brake, it is also necessary to perform a drive maintenance test to confirm whether the electromagnetic brake is released. The spindle servo motor exhibits abnormal speed. The first thing to do is to check the mechanical transmission organization of the servo motor to ensure that the motion of the servo motor is normal.

FANUC spindle drive repair

If there is no abnormality in the mechanical transmission organization of the servo motor, it is necessary to check the cable connection of the spindle servo drive, check the status indicator lights of the spindle servo drive, etc., and analyze whether the spindle drive has problems. If all of the above reasons are eliminated, it is likely that the dashboard is malfunctioning. When the spindle rotates at a high speed and the oscillation is too large, it is mostly caused by the electrical part of the spindle drive system. For this problem, we must check the spindle drive and the electrical connection in various places according to the electrical schematic diagram, and perform drive repair after confirming the fault. And processing.

Examples of FANUC spindle drive repair failures

Fault phenomenon:

A vertical machining center equipped with FANUC 6M, during the processing of the workpiece, the system suddenly cuts off the power, and the machine cannot be restarted after the machine is shut down.

Analysis and processing process:

After checking, the power indicator (PIL) and alarm (ALM) lights of the machine tool power input unit are on together. According to the analysis in section 4.1.1 of this chapter, the reason why the power indicator (PIL) and alarm (ALM) lights are lit together is that there is an alarm in the system power module.

The power module of the measurement system (A14B-0061-B002) found that the output +5V, +15V, -15V, 24V are all 0V, and the input fuses F11 and F12 of the power module are blown. After replacing the fuse, the measurement found that the power input There is a short circuit. Therefore, it is preliminarily judged that there is a short-circuit problem on the primary side of the switching power supply, and the reason for the short-circuit must be found according to the schematic diagram, and the machine tool can be started after the problem is removed.

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