How to do if the speed motor fails

Due to various influences of the environment and other aspects, in the long-term use of the speed-regulating motor, it is easy to cause dust, paper hair, metal shavings, etc. to enter into the motor and affect the normal operation of the motor. The following are common failures.

1. The main drive motor is not operating normally

The slip motor will vibrate during operation, causing the bearing to heat up. Disassemble the clutch armature and the magnetic pole rotor, check whether the motor bearing is seriously lack of lubricating grease, which results in severe wear of the bearing and degraded the running performance of the motor. At this point you need to replace the damaged bearing and add grease. Under normal circumstances, all components of this part of the organization should be cleaned and refueled to ensure the normal operation of the main drive motor.

2. The host rotation speed decreases periodically

In this case, most of them are caused by mechanical failure. The offset roller has more rollers and each roller is supported by the bearing. If the bearing of any one end of a rubber roller fails, the rotation speed of the host may be periodically underground. In severe cases, the rotation of the main engine will be more difficult, and the bearing should be replaced immediately. In addition, it should be noted whether the bearings of the main machine's rollers (including plate, eraser, and impression cylinder) and their lubrication parts are working properly. If a failure occurs, the printing speed will also be affected.

3. After the speed of the offset press is increased, the speed decreases gradually and the machine stops.

In this case, you need to observe the change of the ammeter pointer in the offset cabinet. If it indicates a sharp increase in the current, the overload protection device such as the thermal relay of the main motor will inevitably generate a protection operation, and the main motor will be turned off by three-phase power supply and the operation will be stopped. At this time, it is necessary to carefully check the main motor circuit related to the contact elements and the main motor AC contactor, offset thermal relays and other thermal relays in the electrical cabinet and other overload protection device is loose, if the contact is bad and heat. If there is a problem with these parts, after the main motor speeds up, the current rapidly increases due to poor contact between the wires and components in the circuit, causing a protective shutdown. When the speed of the offset printing machine is low, since the operating current of the main motor is small, the speed of the machine does not gradually decrease and the machine stops. However, when the offset printing press is accelerated, the electric load is large, and the failure of the electric components is reduced. Revealed.

In the actual work, sometimes the terminals in the electrical cabinet of the offset press can be seen to be heated due to bad wire contact, and even an oxide layer appears at the connection. The external anti-burning and discoloration of the wires will affect the main drive motor. The normal operation. At this time, the operator is required to take corresponding measures immediately, such as cleaning the contact surface of the terminal and the wire, fastening the wire screw, removing the burnt oxide layer, and replacing the damaged terminal.

4. The noise of the main drive motor is high

In order to adjust the dynamic balance of the slip motor, weights are installed on both ends of the armature and the pole rotor. If this part of the device is slightly loose, the slip motor will deviate from its original position when it rotates at high speed. If the fault occurs on the outer surface of the main drive motor, it will cause local friction between the armature and the magnetic pole rotor and increase the noise. At this time, it is necessary to stop the repair, restore the dynamic balance of the armature and the magnetic pole rotor, and re-find the position of the original dynamic balance weight and fix it so that the main drive motor can operate normally.

5. The main drive motor brake electromagnetic clutch burned

To ensure the cleanliness of each part of the brake clutch is to avoid the clutch burned, it is necessary to regularly clean all the dust on the top of all electrical components, so that the clutch to maintain ventilation, cooling effect is good, thereby reducing loss, reduce operating temperature, extend the use of electrical components life.