AF泡沫泵葉輪軸面圖的繪制

知道b、D2和D.值之后，繪制葉輪軸面斷面。因?yàn)閷?duì)于抽送磨蝕固液混合物泵的葉輪，系數(shù)k值很大(1.6~2.5) (對(duì)于抽送均質(zhì)液體的泵，當(dāng)n,=80~120時(shí)，kus=0. 6~0.8)，所以葉輪結(jié)構(gòu)不能制作成向出口收縮(例如，在抽送均質(zhì)液體的葉輪上一般可以做到這一點(diǎn))， 通常制成平行壁形式。
    曾經(jīng)指出，軸而斷面在葉輪入口處的形狀，對(duì)流流的成型具有重要影響，因面對(duì)葉片入段和后蓋板的磨損特征和強(qiáng)度具有重要影響(參閱本篇第七章)。因此描述葉輪入口處軸面斷面半徑，根據(jù)后蓋板和葉輪入口邊磨損量最小的條件來選擇。根據(jù)現(xiàn)有資料,決定前蓋板輪席的半徑為Ru=KxD..式中，Kx為軸面斷面系數(shù)，Kx=0.46~0.55. 當(dāng)提高系數(shù)Kn時(shí)，磨損量減少不大，但是葉輪在泵油方向上的尺寸急劇增大。
    決定后蓋板形狀的半徑，考慮所需流道尺寸和面積變化平滑來選取，通常Ru.s<Ru+b (式中， R-1為后蓋板輪席半徑; b, 為葉輪入口段流道寬度)。
    軸面斷面繪制正確性準(zhǔn)則是蓋板之間流道過流面積從入口到出口的變化光滑，可以根據(jù)文獻(xiàn)[179，202]中所述的方法確定。AF泡沫泵

drawing of impeller shaft surface

When the values of B, D2 and D. are known, draw the impeller shaft surface section. Because the coefficient K of the impeller of the pump is very large (1.6-2.5) (for the pump of homogeneous liquid, when n, = 80-120, KUs = 0.6-0.8), the impeller structure can not be made to shrink to the outlet (for example, this can be generally done on the impeller of homogeneous liquid), and it is usually made into parallel wall form.

It has been pointed out that the shape of the shaft and section at the inlet of the impeller has an important influence on the forming of the convective flow, because it has an important influence on the wear characteristics and strength of the blade inlet section and the rear cover plate (see Chapter 7 of this chapter). Therefore, the section radius of the axial surface at the inlet of the impeller is described and selected according to the condition of the minimum wear of the rear cover plate and the inlet edge of the impeller. According to the existing data, it is determined that the radius of the front cover plate wheel seat is Ru = KXD.. where KX is the axial section coefficient, KX = 0.46 ~ 0.55. When the coefficient kn is increased, the wear amount decreases little, but the size of the impeller in the direction of pump oil increases sharply.

The radius of the shape of the rear cover plate is determined by considering the smooth change of the required channel size and area. Generally, Ru. S < Ru + B (where, R-1 is the radius of the rear cover plate wheel seat; B, is the channel width of the impeller inlet section).

The correctness criterion for drawing the axial section is that the flow passage area between the cover plates varies smoothly from the inlet to the outlet, which can be determined by the method described in reference [179, 202].