Common faults and analysis of water ring vacuum pump 1. Fault analysis of water ring pump 2BV/2BE/SK/2SK Shower,Steam Shower,Portable Shower,Hand Shower Heshan Janno Kitchen and Bath Technology Co.,Ltd , https://www.janno-ks.com
1. Vacuum pump mechanical seal leakage cause 1.1. Improper assembly of mechanical seal When replacing the non-power end machine seal, the seal O-ring on the moving ring was not installed during the disassembly process. The O-ring should be installed inside the sealing groove on the moving ring seat, and the disassembly inspection found that the O-ring is not installed as such, but is misplaced in the spring positioning piece, causing the spring to deform and completely fail to axially seal. The role of the leak.
1.2. Machine seal cooling water pressure is too large The sealing force of the machine sealing static ring sealing surface is applied by the spring on the moving ring. When the cooling water pressure is too large, the water pressure will act on the static and dynamic ring. Since the static ring is fixed, the water pressure will push the moving ring and compress the spring in the opposite direction of the static ring, thereby weakening or canceling the static and dynamic torus. The sealing force causes the sealing surface to leak. After the overhaul is completed, the power end machine is sealed into the cooling water test leak, and the inlet valve is opened 2/3 or less. The machine seal is intact and no leakage. When the water valve is opened more than 2/3, the machine seal leaks. The preliminary judgments of the three parties (Maintenance, Alumina Mobile, Sichuan Daewoo Machine Seal Manufacturing Plant) are caused by excessive water pressure. It is recommended to start the operation after the motor is repaired, and further track the true cause of the leakage. .
1.3. Dynamic and static ring sealing surface rupture This is the main reason for the previous several replacements of the pump seal.
The power end and the non-power end machine seal are assembled on the same shaft, the impeller is installed in the middle of the shaft, and the bearing support is fixed at both ends of the shaft. When the power end or non-power end seal is replaced separately, the bearing (bearing seat) of the corresponding end must be removed before the old machine seal can be taken out, and the new machine seal is installed. At this time, because of the gravity of the shaft and the impeller, the bearing support of one end is lost. The impeller and the shaft must collapse downward, and the shaft is inclined toward the bearingless end. Since the static ring of the undetached end is fixed by bolts on the pump end cover, the moving ring is fixed on the shaft and rotates together with the shaft, and because the inner ring of the static ring and the shaft have a small clearance, when the shaft collapses When tilted, it will cause:
a, the unmovable one end of the dynamic and static ring relative displacement, so that the static and dynamic ring sealing surfaces are illegally squeezed each other, causing chipping;
b. The shaft is directly pressed on the inner ring of the unremoved static ring, causing the static ring sealing surface to break or break.
Through the analysis and analysis of the previous several replacement work, the reason that the one end is replaced and the other end of the machine seal is leaked is caused by the above factors. Our operators have actually considered this problem, but the method adopted is not correct: the first few replacements are to use the hoist to hang the shaft of the disassembly end to prevent the shaft from swinging up and down and left and right. In practice, this lifting method is proved to be There are a lot of mistakes, especially for such large vacuum pump seal installations. The reason is that the pulling force of the lifting point and the hoist is difficult to completely control, and it is difficult to avoid the up and down and left and right swings of the shaft.
2. Analysis of the reasons for the difficulty of vacuum pumping. 1) The gap between the two ends of the pump is not adjusted properly.
The bearings at both ends of the pump are double row tapered roller bearings. The two rows of double row tapered roller bearings are in contact with the outer ring and the outer ring is separated from the outer ring. There is a bearing clearance adjusting spacer between the two inner rings, that is, the original clearance of the bearing is controlled by the spacer between the two inner rings. Generally, the gap of the bearing is adjusted when it leaves the factory.
The bearing is assembled on the shaft, one of the two rows of inner rings is placed on the shoulder, and the other column is locked on the shaft by the locking back cap. After locking, the two inner rings and the spacer ring should be tightly connected together. As the shaft rotates together, the outer ring fits tightly with the bearing housing. If the thickness of the gap adjusting spacer is smaller than the original thickness, when the back cap is locked, the two inner rings and the outer ring are unconventionally pressed, so that the bearing is difficult to rotate or cannot be rotated.
2) The inner ring of the bearing is not installed. The inner ring of the bearing is not installed. The problem described in 1) above occurs because the inner and outer rings are misaligned relative to the axial direction, resulting in unconventional force in one of the two inner rings and the outer ring. extrusion. When the power end bearing was removed, it was found that there was a big scar on the shaft surface where the bearing position was installed. It was analyzed and judged that the inner ring of the bearing was not completely topped to the shoulder, which was the main reason for the difficulty of the cranking.
3) The gap between the impeller and the pump end faces is not adjusted. The clearance between the impeller of the water ring vacuum pump and the end faces of the pump body is adjusted by moving the bearing blocks at both ends. The adjustment method is to add or subtract a gasket between the bearing seat and the positioning surface of the bracket on which the bearing housing is mounted.
4) After the machine seals the static ring sealing surface, it will be stuck together.
Second, the water ring vacuum pump seal replacement correct disassembly steps 1. Remove the cooling water pipe sealed at both ends of the pump;
2. Disassemble the power end pulley (there is no such step when replacing the non-power end machine seal);
3. Remove the power and non-power end of the machine cover and hang it on the shaft, pay attention to the light and easy to remove; this step is especially important to avoid damage to the machine seal. (Note: this step is also necessary if the bearings at both ends are separately serviced);
4. Remove the bearing gland where the machine end is to be replaced, and remove the bearing lock back cap;
5. Use the top wire to pull out the bearing housing together with the bearing. (At this time, it is necessary to use the hoist to hang the shaft from the disassembly end to facilitate the ejection of the bearing);
6. Remove the old machine cover from the shaft;
7. Carefully put the new machine seal after inspection on the shaft;
8. Clean and check whether the bearing is in good condition and check whether the bearing clearance is suitable;
9. Put the bearing and bearing seat back on the shaft, add grease to the bearing, tighten the inner ring to lock the back cap, and install the bearing gland (this step also requires the hoist hanging shaft to match);
10. Try to find out if it is easy, especially pay attention to the damage to the machine seal during the process of the car;
11. Reload the machine seals at both ends from the shaft to the inside of the sealed box;
12. Reloading the pulley (there is no such step when repairing the non-power end);
13. Reload the condensate water pipe, and pass the condensed water and test the leak;
14. After the inspection is completed, the work is cleared.
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Common faults and analysis of water ring vacuum pump