Electric spindleIt can be said that it is one of the important mechanical components of machining centers. Daily high-speed machining operations require the electric spindle system of the machine tool not only to have high speed, large output torque and power requirements, but also to have high electric spindle rotation accuracy and maintain good rigidity, impact resistance and thermal stability during high-speed operation. However, during the machining process, due to improper operation and other reasons, the electric spindle of the CNC machine tool may malfunction. Below is an introduction to the fault analysis and maintenance methods of the electric spindle in CNC machining centers.

Fault 1: Electric spindle without braking

1. If the braking circuit is abnormal or the high-voltage electrical components are damaged, check whether the bridge stack, fuses, and AC contactors are damaged; Check if the high-voltage circuit is open.

2. If the braking time is not long enough, adjust the braking time parameters of the system or frequency converter.

3. The system has no brake signal output, and internal components need to be replaced or sent to the factory for maintenance.

4. If the control parameters of the frequency converter are not adjusted properly, please refer to the user manual of the frequency converter and set the parameters correctly.

Fault 2: The electric spindle without a frequency converter does not rotate

1. Caused by mechanical transmission failure, check if the belt drive is damaged or if neutral gear is engaged on the machine tool.

2. The three-phase power supply for the electric spindle is missing or reversed, and the power supply needs to be checked.

3. Circuit connection error, please refer to the circuit connection manual carefully to ensure correct wiring.

4. The system's electric spindle control signal output is not responding. Use a multimeter to measure the system's signal output terminal. If there is no electric spindle control signal output, the relevant IC components need to be replaced or sent to the factory for maintenance.

5. The system responds to the electric spindle control signal output, but the power supply line and control signal output line are short circuited or the components are damaged. Use a multimeter to check if the power supply line, signal control line, or components between the system and the spindle motor are damaged. Use a multimeter to check for short circuits in the power supply circuit and signal control circuit between the system and the electric spindle motor, and to check for damage to the AC contactor and D DC relay.

Fault 3: The electric spindle with a frequency converter does not rotate

1. Caused by mechanical transmission failure, check if the belt drive is damaged or if the machine tool is in neutral gear.

2. The three-phase power supply for the electric spindle is out of phase. Check the power supply and replace any two power cords.

3. The control parameters of the frequency converter in the CNC system have not been turned on. Please refer to the system manual to understand the frequency converter parameters and make changes.

4. The wiring between the system and the frequency converter is incorrect. Please refer to the wiring instructions for the system and frequency converter to understand the frequency conversion parameters and make necessary changes.

5. Abnormal analog voltage output, use a multimeter to check if the analog voltage output of the system matches.

6. Short circuit or damaged components in the high-voltage control section. Check whether the contact connection of the electric spindle power supply circuit is reliable, whether there is a short circuit in the circuit, whether the DC relay is damaged, and whether the fuse is burnt out.

Fault 4: The speed of the electric spindle without frequency conversion is out of control

1. There is a fault in the connecting wires. If the system has a gear shift control signal output, check whether there is a short circuit or poor contact in each connecting wire, and check whether the DC relay or AC contactor is damaged.

2. Check if the electric spindle motor is damaged or short circuited.