渣浆泵的轴向力和径向力

电动机承受系轴向力及其机组质量一种是在电 动机端调整泵叶轮中心(见图557)，由电动机承受泵的轴向力及泵转子质量，常用于深井泵，在小型凝结水泵也有使用。目前，使用此结构的电动机最大功率达200kW左右。另一种是在泵联轴器上调整泵叶轮中心，电动机承受泵的轴向力及泵转子质量，目前已在使用的机组的最大轴向力达几百千牛。
(2)泵承受轴向力此时泵本身带推 力轴承，为了减少泵的轴向推力，有以下几种措施:
1)叶轮加平衡孔，如图5-47 所示，一般适用于 低扬程泵。

2)加平衡鼓，如图5.50和图5-51所示，一般适用于高扬程系。

剩余轴向力和转子质量由泵本身推力轴承承受。

(3)立式泵径向力
1)导叶(流)式泵。其有若干个导叶或扭曲式(空间)导叶(见图5-44、图5-47-图5-51)，故径向力自动平衡。
2)蜗壳式泵。当吐出口径大于80mm时，吐出涡室可设计成双涡室，故径向力自动平衡。
3) 残余径向力及泵转子摆动由导轴承承受，转子越长，导轴承个数越多。

5. 立式泵其他问题

1) 吸入筒体和密封室应设放气阀。
2)吸入段应呈喇叭状，当设置吸人过滤网时，其有效截面应为吸入口过流面积4~6倍，吸入喇叭管口径大于吸入公称通径1.3~1.5倍，甚至更多。
3)泵联轴器与轴配合以间隙配合为好，便于装拆，但其轮毂相对键上应加顶丝。
4)泵的吐出压力应为用户管网进口接头处的压力，泵叶轮处与泵吐出口处压力的差值由泵制造厂来考虑。
5) 立式泵转子部件必须设计成可以轴向调整，以调整叶轮对中。
 6) 如果输送不清洁或无润滑性介质(并非千摩擦)或有颗粒或有规定时，必须要加经硬化处理的轴套，同时还要加护轴管，且护轴管内要通有压、干净液体来润滑。
7)使用半开式叶轮的泵，其壳体相对应处要加可更换的耐磨板。8)立式泵本身没有推力轴承时，其系联轴器应为刚性联轴器。

Axial force and radial force of vertical slurry pump

The motor bears the axial force and the unit mass. One way is to adjust the center of the pump impeller at the motor end (see Figure 557). The motor bears the axial force of the pump and the mass of the pump rotor. It is commonly used in deep well pumps and also used in small condensate pumps. At present, the maximum power of the motor with this structure is about 200kW. The other is to adjust the center of the pump impeller on the pump coupling. The motor bears the axial force of the pump and the mass of the pump rotor. At present, the maximum axial force of the unit in use is hundreds of kilonewtons.

(2) When the pump bears axial force, the pump itself is equipped with thrust bearing. In order to reduce the axial thrust of the pump, the following measures are taken:

1) The impeller is equipped with a balance hole, as shown in Figure 5-47, which is generally applicable to low lift pumps.

2) Balance drum is added, as shown in Fig. 5.50 and Fig. 5-51, which is generally applicable to high lift system.

The residual axial force and rotor mass are borne by the thrust bearing of the pump itself.

(3) Radial force of vertical pump

1) Guide vane (flow) pump. It has several guide vanes or twisted (spatial) guide vanes (see Fig. 5-44, Fig. 5-47 - Fig. 5-51), so the radial force is automatically balanced.

2) Volute pump. When the outlet diameter is greater than 80mm, the outlet vortex chamber can be designed as a double vortex chamber, so the radial force is automatically balanced.

3) The residual radial force and the swing of the pump rotor are borne by the guide bearing. The longer the rotor, the more guide bearings.

5. Other problems of vertical pump

1) The suction cylinder and sealing chamber shall be equipped with air release valve.

2) The suction section shall be trumpet shaped. When the suction filter screen is set, its effective section shall be 4~6 times the overflow area of the suction inlet. The diameter of the suction trumpet pipe is 1.3~1.5 times larger than the nominal suction diameter, or even more.

3) It is better to fit the pump coupling and shaft with clearance for easy assembly and disassembly, but the relative key of the hub shall be provided with jackscrews.

4) The discharge pressure of the pump shall be the pressure at the inlet joint of the user's pipe network, and the difference between the pressure at the pump impeller and the pump discharge outlet shall be considered by the pump manufacturer.

5) Vertical pump rotor components must be designed to be able to be adjusted axially to adjust impeller alignment.

6) If unclean or non lubricating medium (not friction) or particles or regulations are delivered, hardened shaft sleeves must be added and shaft protectors must be added, and the shaft protectors must be lubricated with pressure and clean liquid.

7) For pumps with semi open impeller, replaceable wear plate shall be added at the corresponding position of the casing. 8) When the vertical pump itself has no thrust bearing, its coupling shall be rigid coupling.