Solutions to various machine tool spindle failures

The machine tool spindle refers to the axis that drives the workpiece or tool to rotate on the machine tool. The main shaft of a machine tool is usually composed of a main shaft, bearings and transmission parts (gears or pulleys). There are two main types of high-speed spindles in practical applications: one type is a high-speed electric spindle with zero transmission. Stability, but the output torque and power are limited. The other is a spindle that combines a variable frequency spindle motor and a mechanical speed change mechanism. The torque and power output by this type of spindle are much larger, but the rotation accuracy and stability are relatively poor. Therefore, for this type of spindle, how to correctly design the machine tool spindle and its components has an impact on the machining accuracy of the machine tool. Critical.

Solutions to various machine tool spindle failures

Common faults and solutions of CNC machine tool spindles

1. The spindle without frequency conversion does not rotate

The cause of the failure and the treatment method:

① Caused by mechanical transmission failure: Check whether the belt transmission is broken or whether the machine tool is in neutral gear.

②The three-phase power supply to the spindle is lack of phase or reverse phase: check the power supply and exchange any two power lines.

③ Circuit connection error: carefully refer to the circuit connection manual to ensure that the connection is correct.

④The system has no corresponding spindle control signal output: use a multimeter to measure the system signal output. If there is no spindle control signal output, you need to replace the relevant IC components or send it to the factory for repair. (Guide: Material selection requirements for high-strength bolts)

⑤The system has corresponding spindle control signal output, but the power supply circuit and control signal output circuit are open or the components are damaged: use a multimeter to check the power supply circuit between the system and the spindle motor, whether there is an open circuit in the signal control circuit ; Whether there is an open circuit; whether the contacts between the wires are in poor contact; whether the AC contactor and DC relay are damaged; check whether the thermal relay is over-current; check whether the fuse is burned, etc.

2. The spindle with frequency converter does not rotate

The cause of the failure and the treatment method:

① Caused by mechanical transmission failure: Check whether the belt transmission is broken or whether the machine tool is in neutral gear.

②The three-phase power supply to the spindle is missing phase: check the power supply and exchange any two power lines.

③The inverter control parameters of the CNC system are not opened: refer to the system manual to learn about the inverter parameters and change them.

④ The line connection between the system and the inverter is wrong: refer to the connection manual of the system and the inverter to ensure that the connection is correct.

⑤ The analog voltage output is abnormal: Use a multimeter to check whether the analog voltage output by the system is normal; check whether the analog voltage signal line is connected correctly or poorly, and whether the analog voltage received by the inverter matches.

⑥ The power control part is broken or the components are damaged: check whether the contact connections of the main shaft power supply line are reliable, whether the line is broken, whether the DC relay is damaged, and whether the fuse is burned out.

⑦The inverter parameters are not adjusted well: the inverter contains control mode selection, which is divided into inverter panel control spindle mode, NC system control spindle mode, etc., if the NC system control mode is not selected, the system cannot be used to control the spindle. Modify this parameter; check whether the relevant parameter settings are reasonable.

3. The speed of the spindle without frequency conversion (shift spindle) is not controlled

How to deal with the cause of the failure:

①The system has no S01-S04 control signal output: check whether the system has a shift control signal output. If not, it is a system failure. Replace the IC or send it to the factory for repair.

② Connection line failure: If the system has a shift control signal output, check whether there is an open circuit or poor contact in each connection line, and check whether the DC relay or AC contactor is damaged.

③The spindle motor is damaged or short-circuited: check the spindle motor.

④The machine is not in gear: put the gear in.

Fourth, the spindle has no brake

How to deal with the cause of the failure:

① The brake circuit is abnormal or the strong current components are damaged: check whether the bridge stack, fuse, and AC contactor are damaged; check whether the strong current circuit is open.

② Braking time is not long enough: adjust the braking time parameters of the system or inverter.

③The system has no brake signal output: replace internal components or send it to the factory for repair.

④The inverter control parameters are not adjusted properly: refer to the inverter manual and set the inverter parameters correctly.

5. The spindle stops immediately after starting

How to deal with the cause of the failure

①The system output pulse time is not enough: adjust the M code output time of the system.

②The inverter is in jog state: refer to the instruction manual of the inverter and set the parameters.

③The control components of the spindle circuit are damaged: check whether the contacts on the circuit are in good contact, and check whether the AC contactor of the DC relay is damaged, causing the contacts to not self-lock

④The main shaft motor is short-circuited, causing thermal relay protection: find the cause of the short-circuit and reset the thermal relay.

⑤The spindle control loop does not have a self-locking circuit, and the parameter is set to pulse signal output, so that the spindle can not operate normally: Change the start and stop parameters of the system to control the spindle to level control mode.

VI. Spindle rotation cannot be stopped

How to deal with the cause of the failure

① The AC contactor or DC relay is damaged and closed for a long time and cannot be controlled: replace the AC contactor or DC relay.