渣漿泵的軸向力和徑向力
電動機承受系軸向力及其機組質量一種是在電 動機端調整泵葉輪中心(見圖557)，由電動機承受泵的軸向力及泵轉子質量，常用于深井泵，在小型凝結水泵也有使用。目前，使用此結構的電動機最大功率達200kW左右。另一種是在泵聯(lián)軸器上調整泵葉輪中心，電動機承受泵的軸向力及泵轉子質量，目前已在使用的機組的最大軸向力達幾百千牛。
(2)泵承受軸向力此時泵本身帶推 力軸承，為了減少泵的軸向推力，有以下幾種措施:
1)葉輪加平衡孔，如圖5-47 所示，一般適用于 低揚程泵。
2)加平衡鼓，如圖5.50和圖5-51所示，一般適用于高揚程系。
剩余軸向力和轉子質量由泵本身推力軸承承受。
(3)立式泵徑向力
1)導葉(流)式泵。其有若干個導葉或扭曲式(空間)導葉(見圖5-44、圖5-47-圖5-51)，故徑向力自動平衡。
2)蝸殼式泵。當吐出口徑大于80mm時，吐出渦室可設計成雙渦室，故徑向力自動平衡。
3) 殘余徑向力及泵轉子擺動由導軸承承受，轉子越長，導軸承個數越多。
5. 立式泵其他問題
1) 吸入筒體和密封室應設放氣閥。
2)吸入段應呈喇叭狀，當設置吸人過濾網時，其有效截面應為吸入口過流面積4~6倍，吸入喇叭管口徑大于吸入公稱通徑1.3~1.5倍，甚至更多。
3)泵聯(lián)軸器與軸配合以間隙配合為好，便于裝拆，但其輪轂相對鍵上應加頂絲。
4)泵的吐出壓力應為用戶管網進口接頭處的壓力，泵葉輪處與泵吐出口處壓力的差值由泵制造廠來考慮。
5) 立式泵轉子部件必須設計成可以軸向調整，以調整葉輪對中。
6) 如果輸送不清潔或無潤滑性介質(并非千摩擦)或有顆粒或有規(guī)定時，必須要加經硬化處理的軸套，同時還要加護軸管，且護軸管內要通有壓、干凈液體來潤滑。
7)使用半開式葉輪的泵，其殼體相對應處要加可更換的耐磨板。8)立式泵本身沒有推力軸承時，其系聯(lián)軸器應為剛性聯(lián)軸器。
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.
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