渣浆泵轴向力的产生及其平衡轴向力的产生

1. 轴向力的产生

在单吸离心泵中，由于前后盖板侧面所受压力不同，产生轴向力F1:在悬臂式泵中，由于吸入压力作用于轴湍上而产生轴向力F2:由于液体流入叶轮进口及从叶轮出口的速度、方向不同产生的动反力F3:对于立式泵，转子的重量产生的重力F4，因此泵的轴向力应是上述四种轴向力的总和。
(1)由于前后盖板侧面所受压力不同产生的轴向力F1
    对于单吸叶轮，由于作用在叶轮两侧盖板的压力不等。图2-51表示了单吸叶轮两侧盖板上的压力分布情况:左侧为前盖板上的压力分布，右侧为后盖板上的压力分布。一般认为在叶轮与泵体间液体，因受叶轮旋转效应的影响，以n/2速度旋转。所以在叶轮和泵体间的压力是按抛物线形状分布的。由图2-50可以看出:在密封环半径rw以上，叶轮两侧的压力是对称的，方向相反，相互抵消，没有轴向力;而在密封环半径r。以下，作用在左侧是叶轮入口压力p1，作用在右侧后盖板上的仍是出口压力按抛物线分布的压力，前后盖板压差乘以相应的面积就是作用在叶轮后盖板上的轴向力F1,方向从后盖板指向叶轮进口。

作用在轴尚上的轴向力F

对入口压力较低的泵来说，两轴端上的压差较小，可以忽路不计。而对于入口压力较高的悬臂式单吸泵，必须考虑由作用在轴端上的入口压力所引起的轴向力F2，如图2 -53所示。
    F2与F方向相反。

(3)动反力F

是由于液体进入叶轮后运动方向由轴向变为径向，就给予叶轮一个反冲力F3与F1方向相反，由于较小，常忽略不计。
(4)转子重力FA
    对立式泵，整个转子的重量也是轴向力的一部分，在轴向力计算时需要考虑进去。
2.轴向力的平衡
    泵的轴向力有时会很大，尤其是在高扬程泵、多级泵中，轴向力可达数千公斤，泵的转动部分(转子)在轴向力推动下发生窜动，造成轴承发热、损坏或发生转子与定子的研磨，使泵不能工作。因此，消除泵的轴向力是很重要的，常用的轴向力平衡方法有以下几种。渣浆泵厂家

The generation of axial force of slurry pump and its balanced axial force

1. Generation of axial force

In the single suction centrifugal pump, the axial force F1 is generated due to the different pressure on the side of the front and rear cover plates; in the cantilever pump, the axial force F2 is generated due to the suction pressure acting on the shaft turbulence; the dynamic reaction F3 is generated due to the different speed and direction of the liquid flowing into the impeller inlet and from the impeller outlet; for the vertical pump, the gravity F4 is generated by the weight of the rotor, so the axial force of the pump shall be the above four The sum of the axial forces.

(1) axial force F1 caused by different pressure on the side of front and rear cover plates

For single suction impeller, the pressure acting on the cover plate on both sides of the impeller is not equal. Figure 2-51 shows the pressure distribution on the cover plates on both sides of the single suction impeller: on the left side is the pressure distribution on the front cover plate, and on the right side is the pressure distribution on the rear cover plate. It is generally believed that the liquid between impeller and pump body rotates at n / 2 speed due to the effect of impeller rotation. Therefore, the pressure between impeller and pump body is distributed in parabola shape. It can be seen from figure 2-50 that the pressure on both sides of the impeller is symmetrical and opposite to each other above the sealing ring radius RW, and there is no axial force; while the pressure on both sides of the sealing ring radius R is opposite to each other. Below, on the left side is the impeller inlet pressure P1, on the right rear cover plate is still the outlet pressure distributed in parabola, the pressure difference between the front and rear cover plate multiplied by the corresponding area is the axial force F1 on the rear cover plate of the impeller, and the direction is from the rear cover plate to the impeller inlet.

Axial force F acting on the shaft

For pumps with low inlet pressure, the pressure difference between the two shaft ends is small, which can be ignored. For cantilever single suction pump with high inlet pressure, the axial force F2 caused by the inlet pressure acting on the shaft end must be considered, as shown in figure 2-53.

F2 is opposite to F.

(3) dynamic reaction force F

Because of the change of the direction of movement from axial to radial after the liquid enters the impeller, a reverse force F3 is given to the impeller, which is opposite to the direction F1. Because it is small, it is often ignored.

(4) rotor gravity fa

For vertical pumps, the weight of the whole rotor is also part of the axial force, which needs to be taken into account in the calculation of the axial force.

2. Balance of axial force

Sometimes the axial force of the pump is very large, especially in the high lift pump and multi-stage pump, the axial force can reach thousands of kilograms, and the rotating part (rotor) of the pump will move under the axial force, resulting in the bearing heating, damage or grinding of the rotor and stator, making the pump unable to work. Therefore, it is very important to eliminate the axial force of the pump. The commonly used methods of axial force balance are as follows. Slurry pump manufacturer