Centrifugal pump power does not start or super power reasons and maintenance

Centrifugal pump power does not start or super power causes of the malfunction: ① pump speed is too high. ② pump shaft bending, bearing wear or damage. ③ packing stuffing pump pressure too tight. ④ pump impeller was stuck or pump casing friction serious. ⑤ pump flow is too large. ⑥ drive shaft with a coupling shaft or drive shaft is too tight. ⑦ pump supporting power machine power is too small. ⑧ pump head high. Centrifugal pump power machine does not start or super-power maintenance methods: ① try to reduce the pump speed (taken to change the diameter of the pulley) or replace the lower speed pump, the pump speed and power to match the speed. ② After parking. Disassemble the pump body, check the pump shaft, bearings. If the pump shaft is bent, the pump shaft should be repaired or replaced. a. Pump shaft alignment method To remove the pump shaft for bench verification and find the bend. If conditions permit, you can use the dial indicator on the platform or lathe inspection, but also the pump shaft rack on the V-shaped iron. V-shaped iron put the first solid, then the dial gauge on the table, the rod points to the shaft, and then slowly pull the pump shaft, the shaft has a curved case, each turn, dial indicator has a maximum reading and a minimum Reading, the difference between the two readings is the degree of bending of the shaft. There are many ways to straighten the pump shaft. The easiest way to do it on site is to twist the straight shaft method: on the straight shaft, place the shaft on the hardwood (or on the square iron with copper skin) Soft, and twist bar larger contact surface. Concave down, beat with a hammer, twist rod. Beat when the first place from the maximum curvature, the scope of the fight by the circumference of 1/3, can be pre-drawn on the shaft. 1/3 arc center to play a few more times, the less the number of playing on both sides of the less straight, the initial straight faster, later slower. In the process of twisting but also timely measurement of shaft bending changes; if the bearing wear or damage, you should repair or replace the bearing. b. There are two ways to dismantle the bearing: one is to disassemble on the shaft; the other is to dismantle in the end cap. With a special pull the bearings pulled out from the shaft; if there is no pull, with the wedge-shaped end of the copper rod, bearing in the diagonal direction to withstand the bearing, while using a hammer beat, while the copper rod along the inner ring movement , So that even around the bearing force until knocking down the bearing so far; In addition, you can also use two thick iron plate bearing under the bearing inner ring, and with a cylinder or bracket to hold the shaft support live, the shaft on the end pad thick wood Or copper beat, you can remove the bearing. Due to the cooperation of bearing cap and bearing outer ring, the inner ring of the bearing and the rotating shaft are tighter. Therefore, when removing the end cap, the bearing should be left in the end cap bearing bore. When disassembling the bearing, place the end cover smoothly upwards, and put the board around the bearing hole of the end cover, but pay attention not to bear on the bearing, and then use a copper rod or other metal rod slightly smaller than the bearing outer diameter to reach Bear the bearing outer ring, hammer down the bearing from the top can be knocked out. c. Remove the bearing from the shaft and clean it in cleaning oil (kerosene, diesel, gasoline). d. First of all, check the ball, the inner and outer raceway without scratches, cracks or rust and other defects. Then, the bearing inner ring fixed to make it rotate, if the bearing should be normal rotation balance, speed uniform, no noise and slowly stop; if the bearing is not normal, the performance of noise, vibration, twisting or rotation suddenly stopped. Or by hand to promote the bearing, the issue of percussion or feel excessive clearance and so on. e. bearing repair methods of failure: According to the cause of the bearing failure and wear levels, the common use of the exchange of law and replacement parts repair method. Exchange the use of law is that when the bearing wear does not exceed the allowable value, you can continue to use, the load side (bearing wear more serious) and non-load side of the bearing exchange position to use; replacement repair method is the outer ring or inner bearing Ring cracks, ball crushing, the ball between the bracket fracture, the body of a serious discoloration annealing, raceway has a deeper scratch or rust pit, bearing wear exceeds the allowable value and other phenomena, should be replaced with new pieces. ③ After parking, adjust the gland screw of the stuffing box with a wrench to rotate the pump shaft freely and the water leakage is moderate (usually, the dripping amount is 60 drops / minute). ④ disassemble the pump body after stopping, check the working condition of the impeller. If there is debris on the impeller, you should remove the impeller, and the wound clean; if the gap between the impeller and the pump shell is too small friction, you should adjust the clearance between the impeller and the pump shell to a reasonable value. ⑤ can take appropriate measures to reduce the pump water flow to exclude. There are many ways to regulate the water flow of the pump, the more common are the following four: First, the flow adjustment method, by changing the water pump outlet valve opening degree to regulate the flow. Its advantage is to ensure that the amount of water pump outflow and water wells in balance, to avoid the pump over the ambassador suction water surface exposed, resulting in forced shutdown, the disadvantage is that it will cause pump vibration, shorten the service life of equipment. Therefore, under normal circumstances should not adopt this method to regulate traffic. Second, variable speed regulation, by reducing (raising) the pump speed to adjust the flow. Pump speed changes, by changing the diameter of the pump pulley or change the speed of the power machine to achieve Note that the pump speed decline should not exceed 30% of the rated speed, the increase should be controlled within 10% of the rated speed. Under normal circumstances should be preferred this method. The third is the variable-diameter adjustment method, that is, the appropriate turning of the outer diameter of the impeller becomes smaller to reduce the pump flow and lift. Fourth, variable regulation method is to use multi-stage centrifugal pump to reduce the number of impeller steps to reduce the pump flow and lift, improve device efficiency, so as to achieve the purpose of economic operation. ⑥ check the drive shaft and belt after the drive transmission. If you are using the coupling drive, you can adjust the power machine, pump installation position, the two axes on the same axis correction. If you are using belt drive, you should adjust the belt tension. a. Coupling installation method Put the steel ruler on the coupling halves, then turn the motor shaft by hand and rotate 180 ° to see if the coupling halves are the same or not. If the level of inconsistency, it should be corrected, the correct method is to increase or decrease the thickness of the anti-vibration object below the motor base, until low consistent. That the two machines have been in a coaxial state, they can be the coupling and motor were fixed, and tighten the mounting bolts and nuts can be. b. The method of correcting the different axes of the transmission shaft means that the coupling is correctly installed and the two transmission shafts are coaxial. ⑦ Re-configure the power machine according to the technical parameters marked on the pump nameplate to meet the pump power requirements. ⑧ supporting pump head lift is high, you can take the following methods to adjust: First, reduce the pump speed appropriately to reduce head lift, remove the power machine overload (overload). This method to adjust the larger, but the deceleration should not exceed 30% of the rated speed limit. For the belt driven pump, by changing the diameter of the pulley method to achieve. Second, the pump impeller for turning, or replace the smaller pump impeller to achieve the purpose of reducing the pump head, but this method is limited adjustment range. The third is to replace the power machine with a matching low-lift pump.

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