Explosion-proof mining pump with balance plate refers to MD type multi-stage centrifugal pump for mining. MD type pump is mainly composed of stator, rotor, bearing and shaft seal. The fixed part is composed of the suction section, the middle section, the blade exit section and the guide vane, etc., each section is clamped with a tension bolt to form a working room; the rotor part is composed of a shaft, an impeller, a balance disc and a shaft sleeve; the bearing part has Both rolling bearings and sliding bearings do not bear the axial force; the shaft seal adopts the packing seal, which is mainly composed of the water inlet section and the sealing box body on the tail cover, the packing and the water retaining ring.
When the multi-stage centrifugal pump for mining is working, the liquid enters one side along the axial direction, and the axial force generated by the pump is balanced by the balance plate. The disadvantage of balancing the axial force with the balance disc device is that the failure rate is extremely high and the leakage is large. Generally, the leakage of the balance plate of the pump is 4%~10% of the rated flow, and the high-lift small-flow pump is as high as 20%. Many designers have done a lot of work on the optimization design of the balance plate, and this problem cannot be solved fundamentally.
Due to the installation problems of the MD pump, the assembly quality of the balance plate, the processing quality of the balance plate, the change of working medium, the deviation of the working condition, the damage of the bearing and the blockage of the drain hole of the balance plate, etc., the balance force can be reduced and the bearing can be increased. The additional axial force of the impeller moves the impeller rotor to the water inlet end, aggravating the wear of the impeller large ring and the impeller and the middle section, and the balance force is further reduced, forming a vicious circle. As the degree of wear increases, the gap between the counter wheels often decreases, and even the gap between the two couplings disappears during operation, which causes the motor to vibrate severely, the water pump heats up, and even trips or fails to start, causing the water pump to fail to operate normally.
