离心泵的轴向力径向力平衡

1、Hydraulic forces and balances in centrifugal pumpsmembers：钱培、范佳晨、陈桢、王琪、潘同建 Brief introduction of centrifugal pumps 陈桢Brief introduction of centrifugal pumpsStructure of centrifugal pumpsReasons of the hydraulic forces Effects of hydraulic forces Balance or reduce of hydraulic forces Structure of cen

2、trifugal pumpsReasons of the hydraulic forces For axial thrust： 1、Force difference between hub and shroud 2、Dynamic reaction force 3、For vertical pumps，gravity is the part of axial thrust.For radial force: 1、Deviate from the designed point 2、Dynamic reaction force 3、Horizontal pumps，gravityEffects o

3、f hydraulic forces Axial thrust： 1、large axial thrust，shaft hard to bear 2、Vibration，abrasionRadial thrust： Increase the burden on the shaft，deform and even fracture，vibration，reduce the life of pumpsBalance or reduce of hydraulic forcesFor axial thrust： 1、Use the impeller symmetry to counterpoise （

4、双吸泵） 2、Change the shape of the impeller （背叶片） 3、Use thrust bearing（推力轴承） 4、Balancing device（平衡盘、平衡鼓、两者结合） For radial thrust： 1、for big single-stage pump, use double volute（双蜗壳） 2、Pressurized water chamber are arranged by 180Axial force of centrifugal pumps 王琪Definition of axial forcewhen the centrif

5、ugal pump is in operation, a strong force will generate on its rotor, since the centrifugal force direction parallel to the axis of the shaft, so we called it axial force.Causes of axial force （1） The area of the liquid pressure on the front and back cover of the pump impeller is not equal, and the

6、distribution of the liquid p re s s u re around the pump chamber is also asymmetric.Axial centrifugal force generated causes(2 Liquid flows from the impeller inlet and flows out from the impeller outlet ， whose speed and direction are not the same,so the axial component of the liquid momentum change

7、d.Axial centrifugal force generated causes(3) The axial force, which is caused by the axial force and the axial end of the shaft, is determined by the specific circumstances.(4) The axial force caused by the weight of the rotor is related to the arrangement of the rotor.Methods of balancing axial fo

8、rce(1) balance axial force of centrifugal pump with a thrust bearing(2) balance axial force with the back (deputy) vane Methods of balancing axial force3) balance axial force with double suction impeller. Due to the symmetrical structural, double suction impeller can balance the axial force.(4) bala

9、nce axial force w i t h a n i m p e l l e r arranged symmetricallyMethods of balancing axial force(5) balance axial force with balance drumMethods of balancing axial force(6) Balance the axial force by the method of balance disc.(7) Balance the axial force by the method of a ba l a n c e h o l e o r

10、 equilibrium tube。radial force of centrifugal pumps 潘同建Causes of radial forceRadial thrust on the impeller 1.When the Centrifugal pump is under the optimal conditions, the pressure in the volute is basically uniform. Deviating from the optimal conditions will cause the liquid absolute velocity of th

11、e impeller outflow deviated from the liquid velocity in volute.Pressure distribution in the volute is uneven. small flow rate：C2C big flow rate ：C2C C Flow velocity in the volute 2.Dynamic reaction force The uneven distribution of liquid pressure around the impeller destory Axisymmetric flow.The pressure of a large liquid flow from the impeller is less. Big flow rate Small flow rate Pump gravityThe forces including the radial forces on the impeller and pump gravity cause alternating stress acting on s