FY-type liquid corrosion centrifugal pump for conveying corrosive media, so in the chemical industry to be more widely used. We found in use that the pump graphite PTFE bearings are quite easy to wear, and sometimes even the pump shaft will be bent and deformed, for which we take measures to create a large number of vulnerable parts, but this measure not only caused a large number of materials Waste, while frequent replacement also caused great inconvenience to production. To this end, our technical staff after careful analysis and found that the size of the pump shaft torque can be transmitted to the required, and the pump is vertical installation, does not withstand bending moment, the pump shaft is how it bent? After conclusion, we come to the following conclusion:
1, the relationship between the installation and use of the pump
The measured found that any pump shaft bending occurs, the installation of its verticality are poor. If the pump at the top of the tilt, PTFE Teflon bearings will be the first in the diagonal wear, so that stainless steel sleeve and PTFE Teflon in abnormal working condition. As the wear of the bearing bush increases, the clearance between the sleeve and the bearing bush also gradually increases, causing the deflection of the lower end of the cantilever shaft, which is the center of gravity of the impeller which coincides with the rotation center of the submerged pump shaft. No matter how good the static balance of the original design is, a large imbalance inertial force will also be generated. FY submerged pump speed is generally 2900rmin, so its possible inertial force is indeed great. When this unbalance force exceeds the weight of the rotor, the bearing pairs will be strongly worn. So by the wear of bearings caused by unbalanced inertial force, and unbalanced inertia increases the wear and aggravate the bearing, this vicious cycle will be more serious. As the unbalanced force increases to a certain value, the shaft of the cantilever will eventually be bent. Therefore, the installation of the pump shaft sag is the root cause of bending. The original structure of the pump shaft is covered by the branch, it is more difficult to measure the verticality. The solution is to limit the verticality of the support tube within 0.1mm, the actual use can indeed avoid the pump shaft bending. After we improve the installation accuracy, such failures are significantly reduced in different environments.
2, graphite PTFE bearings
As mentioned above, the cylindrical bush will wear quickly if the shaft is slightly tilted during installation. However, if the bush is replaced by a spherical structure, the concave spherical surface of the bearing bush and the convex spherical surface of the pump shaft sleeve will be uniformly and uniformly exposed no matter whether the shaft is tilted during installation, which will greatly extend the life of the polytetrafluoroethylene bush Service life, and pump installation requirements have been reduced, even if the verticality of the support tube to relax to 1mm, there will be no shaft bending phenomenon. In addition, it must be pointed out that, in order to facilitate the installation, the opening of the sleeve should be provided with a notch in the graphite polytetrafluoroethylene bush. The length of the sleeve should be slightly larger than the diameter of the sleeve and the width should be slightly larger than the length of the sleeve, Sleeve can be fitted into the concave bearing.
3, concluding remarks We FY type liquid pump installation and use of the above improvements, the use efficiency has been greatly improved, saving a lot of manpower and resources, to ensure the normal production, the effect is obvious. FY-type liquid pump is a mature product, demand is great. If you use the factory to install its installation caused enough attention, will be able to get more satisfactory results. On the other hand, I hope the pump factory to do some useful attempts to use spherical graphite PTFE bearings to replace the traditional cylindrical bush, the pump performance more perfect.
1, the relationship between the installation and use of the pump
The measured found that any pump shaft bending occurs, the installation of its verticality are poor. If the pump at the top of the tilt, PTFE Teflon bearings will be the first in the diagonal wear, so that stainless steel sleeve and PTFE Teflon in abnormal working condition. As the wear of the bearing bush increases, the clearance between the sleeve and the bearing bush also gradually increases, causing the deflection of the lower end of the cantilever shaft, which is the center of gravity of the impeller which coincides with the rotation center of the submerged pump shaft. No matter how good the static balance of the original design is, a large imbalance inertial force will also be generated. FY submerged pump speed is generally 2900rmin, so its possible inertial force is indeed great. When this unbalance force exceeds the weight of the rotor, the bearing pairs will be strongly worn. So by the wear of bearings caused by unbalanced inertial force, and unbalanced inertia increases the wear and aggravate the bearing, this vicious cycle will be more serious. As the unbalanced force increases to a certain value, the shaft of the cantilever will eventually be bent. Therefore, the installation of the pump shaft sag is the root cause of bending. The original structure of the pump shaft is covered by the branch, it is more difficult to measure the verticality. The solution is to limit the verticality of the support tube within 0.1mm, the actual use can indeed avoid the pump shaft bending. After we improve the installation accuracy, such failures are significantly reduced in different environments.
2, graphite PTFE bearings
As mentioned above, the cylindrical bush will wear quickly if the shaft is slightly tilted during installation. However, if the bush is replaced by a spherical structure, the concave spherical surface of the bearing bush and the convex spherical surface of the pump shaft sleeve will be uniformly and uniformly exposed no matter whether the shaft is tilted during installation, which will greatly extend the life of the polytetrafluoroethylene bush Service life, and pump installation requirements have been reduced, even if the verticality of the support tube to relax to 1mm, there will be no shaft bending phenomenon. In addition, it must be pointed out that, in order to facilitate the installation, the opening of the sleeve should be provided with a notch in the graphite polytetrafluoroethylene bush. The length of the sleeve should be slightly larger than the diameter of the sleeve and the width should be slightly larger than the length of the sleeve, Sleeve can be fitted into the concave bearing.
3, concluding remarks We FY type liquid pump installation and use of the above improvements, the use efficiency has been greatly improved, saving a lot of manpower and resources, to ensure the normal production, the effect is obvious. FY-type liquid pump is a mature product, demand is great. If you use the factory to install its installation caused enough attention, will be able to get more satisfactory results. On the other hand, I hope the pump factory to do some useful attempts to use spherical graphite PTFE bearings to replace the traditional cylindrical bush, the pump performance more perfect.
Ningbo Yinzhou Leisheng Machinery Co.,Ltd , https://www.nblscasting.com