# Патент USA US3082705

код для вставкиMarch 26, 1963 w. B'USCHHORN 3,082,695 IMPELLERS, ESPECIALLYMSINGLE VANE IMPELLERS FOR ROTARY PUMPS Filed June 15, 1959, _ 360' 270 - ‘R O) FIG.3 ' WALTHER INVENTOR. auscnnorm PU BY Pm‘mbwiapga. A TTOR N 3 ‘ ,. Unite 3,082,695 1C6 Patented Mar. 26, 1963 2 cu2=the tangential component of the absolute speed c of 3,082,695 the ?ow at the outlet of the vane, MELLERS, ESPEQIALLY SINGLE VANE IMPELLERS FOR ROTARY PUMPS rlzthe radius distance of the vane at the inlet, in relation Walther Buschhorn, Pegnitz, Upper Franconia, Ger culzthe tangential component of the absolute speed c of to the axis of rotation of the vane, many, assignor to Klein, Sehanzlin & Becker Aktien the flow at the inlet of the vane. gesellschaft, Frankenthal (Pfalz), Germany Filed June 15, 1959, Ser. No. 820,506 As a guiding device is not usually arranged in front of the impeller, the last term in the bracket of the Equa tlol‘ll I: r1-cul will be equal to zero, so that the general for 2 Claims. (Cl. 103—115) The running of rotary pumps free from oscillations and mu a vibrations is governed primarily by the construction of the impellers employed, whereby unequal distribution of the mass of the individual elements of the impeller in the course of their manufacture has a particularly disturbing is obtained. Herein e?‘ect. Consequently the impellers are dynamically bal 15 r=the radius distance of a vane element, in relation to anced on a special machine before being ?tted in the pump the axis of rotation of the impeller, housing. It is known that a dynamically well-balanced cu=the tangential component of the absolute speed c at impeller, particularly one having only a single vane, is the point of the vane element having the radius dis not capable of ensuring perfect running of the rotary - tance r. pump. This is due to the fact that the transmission of 20 The _work of the impeller according to the invention energy to the liquid being pumped is not uniform along transmitted by the vane to the liquid being pumped can the impeller with the result that the reaction forces re be expressed by the equation: sulting therefrom cause one-sided pressure of the im peller against the stuf?ng-box bearing, packing gaps and the like, and premature wear at these points. This hy 25 wherein draulic unbalance of the rotary pumps is overcome in known manner by increasing the number of vanes of the > k=a constant and go=llhe angle at the center, measured between the begin impeller. Rotary pumps for delivering liquids permeated with long-?brous and band-like impurities are preferably ‘ ning of the vane and the vane element with the radius r. equipped with single vane impellers so as to avoid the 30 The constant k is obtained by dividing the given total blade danger of choking or clogging which has to be feared. It work Hm and the angle at the centre go between which the has hitherto been endeavoured to eliminate the hydraulic vane should or is to extend. unbalance which is particularly apparent in the impellers, Thus with the Equation III it is found that the vane work Hm increases in proportion with the angle at the by arranging a suitable counterweight on the back of the impeller vane. This counterweight is naturally dependent center. Thereby the condition is met at the same time that the same amount of work is transmitted to the liquid upon the number of revolutions and the size as well as the total weight of the impeller and also upon the speci?c gravity of the liquid to be dealt with. As it is theoreti cally not determinable, it has to be ascertained empirically for each impeller. It has already been attempted to elim being pumped by vane elements opposite to each other. If the Equation II is treated in the same way as Equa tion ‘111 and reduced according to the (p into the form inate the hydraulic unbalance in the case of single vane ¢=k—‘:’§'r-cu impellers by twisting the vane in spiral shape. In this The tangential component cu is, according to FIGURE the shape of the vane empirically for each impeller sep arately. (IV) the course of the vane is clearly determined. known type of impellers it is also necessary to determine 1, dependent both upon the radius r and also upon the angle at the center to in the form: ' The object of the present invention is to produce an impeller which is not open to the above-mentioned objec tions. This is attained by plotting the curve of the vane so that the increase in work per vane element is the same on opposite sides of the impeller. This measure becomes 50 particularly effective in the case of an impeller provided with only a single vane extending approximately through 360°, because the shape of the vane which is mostly very complicated and was hitherto ascertained only empirically, are inserted, when in Equation Vb can be determined already in the course of designing. Moreover, it is likewise advantageous to plot the thickness V=volume of the quantity delivered, course of the vane so that its center of mass coincides b=the width of the vane, with the axis of rotations. This renders unnecessary the simultaneous casting of suitable counterweights on the 60 back of the impeller in the manner already practiced. and the value for 0,, is inserted in IV, the result will be To ascertain the course of the vane of the impeller ac cording to the invention, use is made of the known Euler fundamental equation 65 In Equation I Hth=the theoretical lift of the pump, w=the angular speed of the impeller, g=the acceleration due to gravity, r2=the radius distance of the vane at the outlet in relation to the axis of rotation of the vane, Equation VI represents a linear di?erential equation of 1st order. Its solution reads 70 8,082,695 3 A The integration constant C is for ¢=Cg 1:2‘, is equal to V=the volume of the quantity delivered, g: the acceleration due to gravity, bathe width of the vane, g-21r-‘l7)-k+2 C___ _w-21r-b_ 7‘1 w’ * w=the angular speed of the impeller, k=a constant equal to the quotient of the requested theoretical pressure head Hm and the angle at the V g-21r-b-k+2 w-V If this value for C is inserted in Equation VII the ?nal solution of the differential Equation VII reads: center (p so that the work increase per vane element is the same on vr-wz'l) 7'1 10 In FIGURES 1 to 3 of the drawing the subject matter of the invention and the above deductions are explained in detail. opposite sides of the impeller. 2. An impeller for centrifugal pumps substantially pro viding hydraulic equalization over the entire operating range, comprising an impeller, said impeller being formed by a single vane which extends in the form of a spiral over essentially 360° and de?nes a pumping passage ex FIGURE 1 is a diagram of the values used for the deduction for determining the curvature of the vane. This ?gure shows in particular the relationship represented by the Equation V. tending from a point adjacent the axis of the impeller to the periphery thereof, said blade de?ning consecutive blade shape of the vane is shown in FIGURE 4 as calculated from the values of FIGURE 3. I claim: circulation on this element and the product of the ac celeration due to gravity and a constant k, which con elements each having a radial distance r with respect to the FIGURE 3 shows the result of an example calculated axis of rotation of the blade assigned to a center angle with the aid of the above developed relationships for a single vane impeller. Here the angle <p dependent upon 20 measured from the leading edge of the blade to the re spective blade element, the volume of said passage de the radial distance of the vane elements is traced graph termined by said center angle being equal to the quotient ically. The example is based on a delivery quantity of of the product of a predetermined angular velocity of the V=446.4 cubic ‘metres per hour, a speed of 11100 rpm, impeller, said radial distance r of the respective blade a constant impeller width of b=130= nuns. and a distance 31 at the beginning of the blade equal to 110 mms. The 25 element, and the tangential component cu of the flow of stant is equal to the quotient of a predetermined theoreti cal pressure head Hg, and said center angle over which 1. An impeller for centrifugal pumps, substantially pro viding hydraulic equalization over the entire operating 30 the blade is to extend so that the work increase per blade element is the same on opposite sides of the impeller in range, comprising an impeller, the passage of which is any radial plane. formed by a single vane extending in the form of a spiral approximately over 360°, the curve of said spiral essenti ally conforming to the equation g0=the angle at the center, measured between the be ginning of the vane and the vane element with the radius r, r=the radius distance of a vane element in relation to the axis of rotation of the impeller, r1=the radius distance of the vane at the inlet in rela— tion to the axis of rotation of the vane, 35 4O References Cited in the ?le of this patent UNITED STATES PATENTS 450,491 963,378 Nicholas et al _________ __ Apr. 14, 1891 Lorenz ______________ __ July 5, 1910 2,245,035 Hartman ______________ __ June 10, 1941 2,655,868 2,853,019 Lindau et al ___________ __ Oct. 20, 1953 Thornton ____________ __ Sept. 23, 1958 1,324 Great Britain _______________ __ of 1863 23,234 340,152 Germany ____________ __ Dec. 30, 1881 Great Britain ________ __ Dec. 24, 1930 FOREIGN PATENTS

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