How to prevent high-voltage motor bearings are not burned

A thermal power plant with a motor power of 220 kW, the voltage is 6 kV. Motor shaft extension end with 2322E cylindrical roller bearings, non-axial extension with 6322 deep groove ball bearings. In 2004 the motor in operation, there is a sharp increase in shaft bearing temperature, bearing oil color, and accompanied by the smell of smoke and smoke smoke situation. Run on duty after the staff check that the motor shaft shaft bearings burned, and the motor rotor lock.
    1 accident investigation
    After the accident, maintenance personnel on the motor disassembly, found:
    (1) motor shaft extension bearing burned, bearing frame, roller wear serious, off, bearing outer ring local blue;
    (2) bearing chamber has obvious wear marks, and accompanied by deep cracks;
    (3) the rotor shaft and the inner and outer oil cover junction, there are many deep wear marks;
    (4) motor shaft extension end bearing, the outer oil cover burned.
    Disassembled after the inspection, but also to check the motor maintenance records and found that the motor 2 years ago had replaced both ends of the bearing. In the replacement of bearings, the motor shaft extension bearing and bearing room tolerance with the existence of a problem, the bearing has a slight external circle phenomenon, but not processed. Replace the bearing, the motor only in February 2004 to add a refueling, in addition, there is no maintenance records.
    2 Cause analysis
    (1) maintenance personnel do not go to the bearing outside the defect handling, resulting in long-term operation after the bearing heat, burned.
    (2) maintenance personnel failed to timely refueling the motor maintenance.
    According to the regulations, the motor refueling cycle of 2 000 h; cleaning bearings, grease replacement cycle for 1 year. But in more than two years of operation, only refueling once, and did not replace the grease. As the motor running environment is poor, coupled with long-term operation, so that oil quality deterioration, bearing lack of oil, resulting in bearing burned.
    (3) the motor bearing refueling, just in the winter, the temperature is low, the increase in the hardness of lubricants. Due to improper refueling operation, resulting in grease can not fully enter the bearing inside, not a good lubrication, resulting in bearing burned.
    (4) the operator found that the motor has a fever phenomenon, not in a timely manner with the local accident button emergency outage failure equipment, but the first report to the leadership, and then outage the equipment to extend the accident processing time, resulting in accidents.
    3 Precautions and Countermeasures
    (1) Replace the bearing at both ends of the motor, the axle end bearing chamber and the inner and outer oil cap, and repair the worn motor rotor shaft.
    (2) to develop "motor bearing refueling maintenance work regulations", re-clear and stressed the motor bearing refueling and overhaul cycle.
    (3) organization maintenance personnel to further study the motor maintenance procedures, improve business skills. Strengthen the organization and management of equipment maintenance. At the same time, in the winter to run the equipment to add fuel, should be appropriate to the motor bearing oil cap heating, so that the new grease can fully enter the bearing inside.
    (4) In the operation and management of the equipment, it is required to monitor the operation of the equipment with abnormal (fever, noise, vibration) and to stop the equipment in time.


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