Croos Pump (Shanghai) Co., Ltd.

The Maintenance of the Failures of the Water Clean Pumps

The water clean pump is the integral of motor and water pump, and the bearing of the motor rotor is a pump bearing. The pump impeller rotating work reducing valve is presented with rigid power transmission. There is a gap between 0.10-0.22 mm of water pump impeller and the vortex shell debris, sand stuck dead impeller, the litter granule is easy to get the impeller stuck, and make the motor rotor unable to rotate and malfunction. The failure analysis of the water clean pump accounted for more than 80% of the damage caused by the stuck of the impeller. When the power switch is turned off, if the motor is not turned, the power should be turned off in time. The motor will be used to generate the rotating magnetic field in the working time, and the motor will not be damaged in a short time. You can use a screwdriver to remove the back cover of the motor, and turn the fan blade to the back of the back cover.

The repair of impeller and swig ring

After a certain period of time, the pump should be repaired and disintegrated after a period of 6 months. The impeller and the swig ring are vulnerable parts, and should be repaired and replaced regularly.  The main damage form of impeller and swig ring is wear, resulting in the change of clearance. When the clearance exceeds a certain value, the efficiency of water clean pump drops sharply, accompanied by a large vibration and noise, which must be repaired at this time. The time interval between this kind of damage is generally proportional to the running time of the pump, and it can be used for preventive maintenance. Generally speaking, the pump with the impeller is located in the middle part is easiest to wear (head impeller material is alloy cast steel, the other impeller for the production of cast iron), and the big ring wear heavier, impeller inlet diameter wear lighter, at this point, the impeller can be used to cut the entrance to the lathe slightly, or sand cloth to polish smooth, then, according to the outer diameter of the impeller inlet, the new opening ring should be changed to meet the original matching requirements. In order to improve the efficiency of maintenance, we can mark the opening and impeller during the repair process to avoid confusion and increase maintenance.

When the outer diameter of the impeller inlet is larger, it can be repaired by surfacing, plating and spray-welding repair. In the case of surfacing welding, it shall be used for surfacing welding of the same quality welding rod. After surfacing welding, it is necessary to pay attention to the insulation of the welding zone to prevent the appearance of the white mouth tissue. Then the grinding of lathe or grinding machine is to reach the specified size. When the outer diameter of the impeller entrance is badly worn or broken, the repair value has been lost and the new one can be replaced.

During the maintenance, attention should be paid to the internal clogging of the impeller. Because there will be many impurities in the mine water, such as small pieces of wood, bark, small coal, etc. They are often stuck in the passage of the impeller, affecting the flow and efficiency of the pump, which occurs more in the first and second stage impeller and must be removed. Several gaps that need to be guaranteed during the repair process: the gap between the size and mouth is 0.4 ~ 0.5 mm, the interplay clearance between the outer and guide vane inlet of the water wheel is 0.8 ~ 1.2 mm, the inner and outer space of the countervail of the balance plate is 0.8 ~ 1.0 mm.

The common methods for straightening of pump shaft bending

(1) the shaft is placed on the platform with the manual screw corrector. It is supported by two v-shaped iron, and then the curved part of the convex surface is facing up, so that the screw is held up.
Then rotate the handle to tighten the screw head on the pump shaft. The corrector can move in the direction of the axial bend and repeat the correction several times until it is completely straightened (and has a certain amount of reverse bending).

(2) the method is to use a twister to direct the alignment of the axis by bending the curved surface of the axis, and the surface of the shaft is extended and straightened. When straightened, the concave of the shaft is facing up, and the maximum bending of the convex surface as a support point, tightly supported, and the ends are pressed by the card, then, with a 1~2 kg hammer, knock the twig, and the surface of the concave surface of the shaft is hit and extended. Start by tapping into the center of the lowest concave, and gradually moves to the sides, and it goes on the arc of a third of the circumference, but the more it goes to the center, the greater the density. Be careful not to damage the surface of the shaft.

(3) the shaft of the heating straightening pump is at the convex surface of the larger bend, and heat it locally, and control the temperature under 600 ℃, then, the two ends of the axis can be found, and the underside cushion should be placed below. Add pressure to the biggest bend (convex surface). The temperature should rise slowly and not too fast. Heating area and pressure size should be determined according to specific conditions. The supporting plate is lower than the requirement of the straightening position, generally 1~ 4 mm, which is related to the type of shaft material, heating temperature, pressure size and speed of casting. After the pump shaft alignment meets the requirements, the asbestos insulation number for the axial heating area is cooled by h. After straightening, the shaft should be annealed to make the shaft rotate slowly. When heated to a temperature of about 350 ℃, heat preservation more than 1 hour, and then wrapped it in the heat, when cooled to about 70 ℃ with the rotation of the axis, and then natural cooling in the air.
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