Domestic large-scale vertical centrifugal pump in the course of running, vibration, up and down bearing often fever, damage, and even parts of the pump shaft and bearing wear. Water pump operation is unstable, affecting the normal water supply, need to carry out vibration control.
First, the pump vibration analysis
1, domestic vertical pump 28SLA-10 is a direct transformation by the horizontal pump. The vertical height between the base of the motor and the pump base is 4.3m, and the transmission shaft weighs 3t. Relative to the horizontal pump, it added a length of 3752mm diameter 140mm intermediate drive shaft. In the structure, in addition to the installation of a bearing on the intermediate shaft, without any transformation (as shown in Figure 1). The four pumps running pressure for a long time 0.7 ~ 0.85MPa. In the high head, high flow conditions, such a high center of gravity, high-quality system of high-speed rotation, resulting in centrifugal force is great, will cause a larger vibration unit. Coupled with bracket and pump out of the water direction of the connection stiffness is not enough, resulting in a larger displacement of the pump and the connector. Displacement of the pump during operation led to changes in bearing conditions on the force, vibration increased, so easy to heat. If the pump displacement correction, improved bearing force conditions, can reduce the system's vibration intensity.
2, between the pump and the drive shaft for the rigid connection. Due to manufacturing, installation reasons, run-time shaft and drive shaft concentric, resulting in pump vibration; motor, drive shaft and other vibration generated by the source directly to the pump to form a superposition of vibration, and further increase the pump vibration. In addition, this rigid connection to increase the pump bearing on the external force, resulting in bearing easy to heat, affecting the pump shaft.
Second, the transformation situation
For the above reasons, we have taken the following two steps to transform.
1, to strengthen the pipe stiffness. Taking into account the reinforcement of the pump is more difficult to take in the export of steel pipe welding 'stiffener' approach. Along the direction of the inlet and outlet water, the two ends of the connecting pipe between the pump outlet divergent pipe and the water outlet valve are welded with 8 steel plates having a thickness of 32 mm and a width of 100 mm. Increase the stiffness of steel pipe, reduce the deformation, resistance to pump displacement. After measurement, after reinforcement, the water pump A point of displacement to 0.35mm.
2, to transform the transmission system. In order to reduce the motor, the transmission shaft vibration to the pump, the pump and the transmission shaft between the rigid connection to flexible connection. Use GB4323-84 elastic sleeve pin coupling, the maximum compensation displacement of 0.6mm, compensation angle of 1 ° 30 '. In this way, the vibration of the motor and the drive shaft can be compensated by the elastic coupling and will not be directly transmitted to the water pump.
Third, the transformation results
After the transformation, measured by the vertical centrifugal pump vibration from the transformation of the former 4.3cm / s vibration velocity was reduced to 1.48cm / s. According to the vibration intensity standard ISO2372-1974 can determine the pump running in the area of excellence. At the same time, the pump running smoothly, only the normal maintenance of the bearing, shaft wear phenomenon is not, that transformation is successful.
First, the pump vibration analysis
1, domestic vertical pump 28SLA-10 is a direct transformation by the horizontal pump. The vertical height between the base of the motor and the pump base is 4.3m, and the transmission shaft weighs 3t. Relative to the horizontal pump, it added a length of 3752mm diameter 140mm intermediate drive shaft. In the structure, in addition to the installation of a bearing on the intermediate shaft, without any transformation (as shown in Figure 1). The four pumps running pressure for a long time 0.7 ~ 0.85MPa. In the high head, high flow conditions, such a high center of gravity, high-quality system of high-speed rotation, resulting in centrifugal force is great, will cause a larger vibration unit. Coupled with bracket and pump out of the water direction of the connection stiffness is not enough, resulting in a larger displacement of the pump and the connector. Displacement of the pump during operation led to changes in bearing conditions on the force, vibration increased, so easy to heat. If the pump displacement correction, improved bearing force conditions, can reduce the system's vibration intensity.
2, between the pump and the drive shaft for the rigid connection. Due to manufacturing, installation reasons, run-time shaft and drive shaft concentric, resulting in pump vibration; motor, drive shaft and other vibration generated by the source directly to the pump to form a superposition of vibration, and further increase the pump vibration. In addition, this rigid connection to increase the pump bearing on the external force, resulting in bearing easy to heat, affecting the pump shaft.
Second, the transformation situation
For the above reasons, we have taken the following two steps to transform.
1, to strengthen the pipe stiffness. Taking into account the reinforcement of the pump is more difficult to take in the export of steel pipe welding 'stiffener' approach. Along the direction of the inlet and outlet water, the two ends of the connecting pipe between the pump outlet divergent pipe and the water outlet valve are welded with 8 steel plates having a thickness of 32 mm and a width of 100 mm. Increase the stiffness of steel pipe, reduce the deformation, resistance to pump displacement. After measurement, after reinforcement, the water pump A point of displacement to 0.35mm.
2, to transform the transmission system. In order to reduce the motor, the transmission shaft vibration to the pump, the pump and the transmission shaft between the rigid connection to flexible connection. Use GB4323-84 elastic sleeve pin coupling, the maximum compensation displacement of 0.6mm, compensation angle of 1 ° 30 '. In this way, the vibration of the motor and the drive shaft can be compensated by the elastic coupling and will not be directly transmitted to the water pump.
Third, the transformation results
After the transformation, measured by the vertical centrifugal pump vibration from the transformation of the former 4.3cm / s vibration velocity was reduced to 1.48cm / s. According to the vibration intensity standard ISO2372-1974 can determine the pump running in the area of excellence. At the same time, the pump running smoothly, only the normal maintenance of the bearing, shaft wear phenomenon is not, that transformation is successful.
Manufacturers recommend: Shenlong fountain submersible pump
Keywords:Pump, vibration reason, reforming method
没有评论:
发表评论