Common Faults and Solutions of Various CNC Machine Tool Spindles
One is the high-speed motorized spindle with zero transmission. This kind of spindle has good rotation accuracy and stability due to the integrated structure of motor and machine tool spindle and accurate dynamic balance correction, but it limits the output torque and power.
The other is the spindle with the combination of variable frequency spindle motor and mechanical speed change mechanism. The output torque and power of this kind of spindle are much larger, but the rotation accuracy and stability are relatively poor. Therefore, for this kind of spindle, how to correctly design the influence of machine tool spindle and its components on machine tool machining accuracy is very important.
Common faults and solutions of NC machine tool spindle
1 Spindle without frequency conversion does not rotate
Fault cause and treatment method:
Caused by mechanical transmission failure: check whether the belt transmission is broken or whether the machine tool is in neutral.
The three-phase power supply to the spindle is out of phase or reversed phase: check the power supply and replace any two power lines.
Circuit connection error: carefully refer to the circuit connection manual to ensure that the wiring is correct.
The system has no corresponding spindle control signal output: measure the signal output end of the system with a multimeter. If there is no spindle control signal output, replace relevant IC components or send them to the factory for maintenance.
The system has corresponding spindle control signal output, but the power supply line and control signal output line are open circuit or components are damaged: use a multimeter to check the power supply circuit between the system and spindle motor and whether the signal control circuit is open circuit; Whether there is an open circuit; Whether the contact between the connecting wires is poor; Whether the AC contactor and DC relay are damaged; Check whether the thermal relay has overcurrent; Check whether the fuse tube is burned, etc.
2 Spindle with frequency converter does not rotate
Fault cause and treatment method:
Caused by mechanical transmission failure: check whether the belt transmission is broken or whether the machine tool is in neutral.
The three-phase power supply to the spindle is out of phase: check the power supply and replace any two power lines.
The frequency converter control parameters of the NC system are not opened: refer to the system manual to understand the frequency conversion parameters and change them.
Wrong line connection between the system and the frequency converter: refer to the connection manual between the system and the frequency converter to ensure that the connection is correct.
Abnormal analog voltage output: check whether the analog voltage output by the system is normal with a multimeter; Check whether the analog voltage signal line is connected correctly or poorly, and whether the analog voltage received by the frequency converter matches.
The strong current control part is open circuit or the components are damaged: check whether the contact connection of the main shaft power supply line is reliable, whether the line is open circuit, whether the DC relay is damaged and whether the fuse is burned out.
The frequency converter parameters are not adjusted properly: the frequency converter contains control mode selection, which is divided into frequency converter panel control spindle mode, NC system control spindle mode, etc. if the NC system control mode is not selected, the spindle cannot be controlled by the system, and this parameter can be modified; Check whether the relevant parameter settings are reasonable.
3 The speed of spindle (shift spindle) without frequency conversion is not controlled
Fault cause and treatment method:
The system has no control signal output of S01 - S04: check whether the system has shift control signal output. If not, it is a system fault. Replace the IC or send it to the factory for maintenance.
Connection line fault: if the system has shift control signal output, check whether each connection line has open circuit or poor contact, and check whether the DC relay or AC contactor is damaged.
Damage or short circuit of spindle motor: check the spindle motor.
Mechanical not engaged: engage the gear.
4 Spindle without braking
Fault cause and treatment method:
Abnormal braking circuit or damage of strong current components: check whether the bridge stack, fuse and AC contactor are damaged; Check whether the strong current circuit is open.
Braking time is not long enough: adjust the braking time parameters of the system or frequency converter.
The system has no braking signal output: replace internal components or send them to the factory for maintenance.
The control parameters of the frequency converter are not adjusted well: refer to the operation manual of the frequency converter and set the frequency converter parameters correctly.
5 The spindle stops immediately after starting
Fault causes and treatment methods
Insufficient system output pulse time: adjust the M code output time of the system.
The frequency converter is in inching state: refer to the operation manual of the frequency converter and set the parameters.
The control components of the spindle line are damaged: check whether the contacts on the circuit are in good contact, and check whether the DC relay and AC contactor are damaged, resulting in non self-locking of the contacts
Thermal relay protection caused by short circuit of spindle motor: find out the cause of short circuit and reset the thermal relay.
There is no self-locking circuit in the spindle control circuit, but the parameters are set as pulse signal output, so that the spindle can not operate normally: change the start and stop parameters of the system control spindle to level control mode.
Fault cause and treatment method:
AC contactor or DC relay is damaged and cannot be controlled due to long-time pull-in: replace AC contactor or DC relay.
