How to adjust the speed of motor and equipment maintenance

In the long-term use of the speed-adjusting motor, due to the poor working environment conditions, the untidy ground, and the long time, it is easy to make dust and paper hair due to the energization of the charged and armature and the electromagnetic attraction of the motor. The metal chips enter the inside of the motor and adhere to the inner hole of the clutch armature and the surface of the magnetic pole rotor. Once accumulated too much, it will clog the gap between them, so that the magnetic pole rotor and the asynchronous motor rotate at the same speed, there is a phenomenon of printing high-speed "speed", the speed can not be adjusted, in serious cases, even the relevant components of the ring motor slip clutch control device. Therefore, for the offset motor of the offset press, it should be periodically removed and cleaned on an annual basis to avoid such problems. The following faults often occur in the offset system's electrical system due to poor maintenance.

. 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.

. The main engine 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 that the main rollers of the main machine, including the printing-printing-rubber, and the impression roller, are normally operating in the bearings and their lubrication parts. If a failure occurs, the printing speed will also be affected.

. After the speed of the offset press is increased, the speed gradually decreases 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.

. Main drive motor noise during operation

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.

. Main drive motor brake electromagnetic clutch burned

The yoke, armature, friction plates, etc. of the offset brake clutch must be kept clean, free of oil and any foreign matter. Regardless of any electrical components, if excessive amounts of paper, dust, and metal shavings are attached, working hours can easily lead to heating of the electrical components and poor contact. Moreover, these impurities in the friction plates increase the clutch not to absorb. Closing friction load and damage. At this time, the electrical component does not absorb due to poor contact, so that its temperature increases, the insulation of the brake electromagnetic clutch coil will be prematurely damaged, and eventually burned. Therefore, special attention must be paid to maintenance. Regular brushing of petrol is used to brush oil and other impurities on the friction plate and other components. Clean up the paper wool, dust and other impurities on the electrical components in the electrical cabinet of the offset press to facilitate the cooling and ventilation of the clutch. Reduce losses, reduce operating temperatures, and extend the life of electrical components.