Reasons for the shaft holding phenomenon of explosion-proof motors

First, the explosion-proof motor bearing itself is faulty

The bearings of explosion-proof motors may fail due to the influence of heat. Explosion-proof motor bearings can run well under good lubrication conditions, and explosion-proof motor bearings can be directly damaged as a whole.

2. Explosion-proof motor bearing lubrication

It is very convenient to add grease for explosion-proof motors. The temperature resistance of the grease (-10~130°C) can meet the lubrication requirements of explosion-proof motor bearings.

3. Radial friction between bearing gland and journal of explosion-proof motor

From the analysis of the radial gap between the bearing gland and the journal of the explosion-proof motor, according to the requirements of the national standard, the explosion-proof motor must ensure that when the electric spark occurs inside the explosion-proof motor, it must be cooled by the gap seal and the gap between the moving part and the outside to ensure Do not ignite the flammable and explosive media outside the motor.

4. Rotor vibration of explosion-proof motor

Explosion-proof motor shaft bending will cause the gap between the bearing gland and the matching journal to change, and the rotor bending and unbalance will cause the motor rotor to vibrate during operation. is mutual.
Explosion-proof motor shaft holding failure measures:

Dismantling and inspection of the faulty explosion-proof motor and analysis of similar fault repair technical data show that the fault of the motor bearing shaft is caused by the mutual friction between the gland and the rotor journal, which leads to the failure of the bearing grease at high temperature, and the bearing is in poor lubrication. Running under high temperature conditions, the bearing wear caused the friction between the gland and the rotor journal to become more serious, which eventually led to the high temperature bonding of the bearing gland and the journal, causing the motor overload protection to trip.
 
Strictly control the dimensional tolerances of the end cover seat hole and the bearing journal. Regular maintenance of explosion-proof motor bearings, long-term lubrication of explosion-proof motors.

 


Post time: Aug-26-2023