US2811926A

US2811926A - Variable-capacity rotary-vane pump

Info

Publication number: US2811926A
Application number: US602788A
Authority: US
Inventors: Jr George D Robinson
Original assignee: Gilbert and Barker Manufacturing Co Inc
Current assignee: Gilbarco Inc
Priority date: 1956-08-08
Filing date: 1956-08-08
Publication date: 1957-11-05
Anticipated expiration: 1974-11-05

Description

Nov. 5, 1957 c. D. ROBINSON, JR 2,811,926

VARIABLE-CAPACITY ROTARY-VANE PUMP Filed Aug. 8, 1956 2 Sheets-Sheet l FIGJ I 5 lav/ INVENTOR GEORGE D.- ROBINSON ,JR-

@ ATTORNEYS Nov. 5, 1957 G. D. ROBINSON, JR 2,811,926

VARIABLE-CAPACITY ROTARY-VANE PUMP 2 Sheets-Sheet 2 Filed Aug. 8, 1956 FIG". 4

FIC3-5 INVENTOF? GEORGE D- ROBINSON, JR

W4 *M. BY ATTORNEYS United Sttes Patent ffice 2,81 1,926 Patented Nov. 195 7 2 8113926 VARIABLE-GAPACITY ROTARY-VANE. PUMP George D. Robinson; In, Agawam, Mass assignor to Gilbert & Earlier Manufacturing Company, West Springfield} Massi; a corporation: of Massachusetts- Application August 8,. 1956,. Serial No. 602,788

I Claim. (CF. 3 -1216) This invention relates to improvements in variablecapacity pumps of the rotary-vane type.

The invention has for its object the provision of improved means for shifting the cylinder of the pump from active pumping position to inactive pumping position by the application of hydraulic pressure to the external surface of the pump cylinder without necessitating the formation of aspecial cylinder in the pump housing and a piston for the purpose.

This invention will be disclosed with reference to one illustrative embodiment of it in the accompanying draw ings, in which 7 i i V I Fig. 1 is an elevational view, partly in longitudinal sec tion, of a rotary-vane-type pump embodying, the invention;

Fig. 2 is a cross sectional view taken ou the line 2-2 of Fig. 1, showing the pump positioned for pumping at the maximum rate;

Fig. 3 is a' View, taken simi-lar lyto Fig. 2 but showing the pump in non pumping-posit-iongg j Fig. 4 is a sectional plan-view t'alien' on the l'i'n'e 4 -4 of Fig. 2;

Fig. 5 is a cross sectional view taken on the line 5-5 of Fig. 1; and

Fig. 6 is a fragmentary sectional view taken on the line 6-6 of Fig. 2.

Referring to these drawings; the rotary pump has been shown in one of its adaptations, namely, for the purpose of priming a centrifugal pump. The latter has been shown in part only as the invention is not limited to this one specific use. However, the complete centrifugal pump and the connections between it and the rotary pump are fully disclosed in the Alfred L. Grise Patent No. 2,612,844, granted October 7, 1952, to the assignee of the present invention. Reference to this patent may be had for a complete disclosure of the centrifugal pump it necessary or desired.

The rotary pump of this invention includes an outer housing which is composed of two side wall members 1 and 2 and an intervening annular member 3, which affords a peripheral wall surrounding a chamber 4, the end walls of which consist of the inner fiat faces of the side wall members 1 and 2. The peripheral wall of chamber 4 is composed of two opposed semi-cylindrical surfaces 5 and 6, the axes of which are respectively indicated at 5 and 6', and intervening connecting grooves 7 and 8, herein shown as semi-cylindrical in form. The groove 8 receives a fulcrum pin 9 which is engaged in a similar groove 1% in the stator 11 of the pump.

This stator is of hollow cylindrical form with coaxiallydisposed inner and outer cylindrical surfaces 12 and 13. Its ends abut the inner fiat faces of the side walls 1 and 2. A plunger 14, slidably mounted in a drilled hole in wall 3, is urged radially inwardly by a spring 15, bearing on the top of stator 11 and tending to move it downwardly into a first position wherein substantially all of the lower half of its cylindrical periphery 13 abuts and tightly fits the lower semi-cylindrical surface 6. The stator is movable upwardly to asecond position in which substantially allot the upper half of its cylindrical periphery abuts and closely fitsthe semi cylindrical surface 5. Recesses- 16 and 17 are formed in; the upper and lower periphery of stator 11 and these become closed when the stator is moved into its secondand first-named positions, respectively, as will be clear from comparing. Figs. 2 and 3. Itwill be clear that there is 'no communication between these recesses 16 and 17.- v

v The pump rotor 18 is of the Well known vane type. It iscylindrical in form and provided with a circular series of angularly-spacedradially disposed vanes 19 which are sl-idably mounted in slots formed in the rotor. The ends of the rotor have annular recesses 20 therein, which re ceive one in each, rings 21, supporting the ends of all the vanes and holding their outer edges engaged with the inner cylindrical wall of the stator. When the stator is in its first-or lowermostposition the. axes of the rotor and stator. are not coaxial and the rotor is positioned for pumping at the maximum rate.- When the rotor is in its second or uppermost position the rotor and stator are coaxial and no pumping occurs. The rotor 18 is suitably figred, as indicated, to a driving shaft 22 which is suitably supportedin the same way as disclosed in the above-named Grise patent, in a sleeve bearing 23' fixed in sidewall memberand by other bearings contained in thehollow membe; 24;

This' member the side; wall member 1, the pe= riplieral 'wall member} and side wall' member 2 are suitablyclamped together as" for example, by a series of cap screws 25' whichpass through holes in the several members and thread into the member 2' which forms a side wan of the centrifugal pump lfou'sirfgi. The. im eller of the centrifugal pump is shownin' part at 27 and has a series of" lioles 28 tlierein', through which fluid may be drawnfrmn radiar Inca dens near the'ihret eyeof the hous ing into the inlet port of the rotary priming pump.

The inlet and outlet ports of the rotary pump are marked 29 and 30 and they are respectively formed in the side wall members 2 and 1 (Fig. 6). These ports 29 i and 30 are in the form of arcuate slots which are separately shown in Figs. 2 and 5, respectively. The slot 29 communicates with all the holes 28 in the impeller and the slot 30 is connected by means in part at 31 in Fig. 4 and fully disclosed in the Grise patent, to the outlet of the centrifugal pump. Of course, if the rotary pump is not to be connected to a centrifugal pump, these slots will be suitably covered except for the necessary inlet and outlet passages. The inlet port 29 is in continuous communication with the recess 16 in member 11 by means of a radial hole 32 (Figs. 2 and 6) formed in said member. The outlet port 30 is in continuous communication with the recess 17 by means of a second radial hole 33 (Fig. 6) formed in member 11.

In operation, assuming the parts to be positioned as in Fig. 2 and the rotor to be revolving counterclockwise, fluid, initially air, will be drawn from the eye of the impeller through the passages 28 and the inlet port 29 into the cylinder 11 and the spaces between successive blades 19 and carried to the outlet port 30 and expelled therefrom through passage 31, all in the usual and well known manner. No substantial pressure will be built up until the air has been eliminated. Liquid is then drawn in by the pump and pressure builds up. When sufficient pressure builds up, then the pump cylinder 11 is to be moved by such pressure into its inactive position shown in Fig. 3. To some extent, this cylinder may be moved by the differential pressure within the cylinder because there is a greater area exposed to such pressure in the space that lies above a horizontal plane passing through the axis of the fulcrum 9 than there is below such plane. However, this invention also provides for pressure outside the cylinder in order to get a greater force to more quickly move the cylinder 11 from one extreme position to the other. While this has been done before by a piston and cylinder arrangement, such for example, as shown in the abovenamed Grise patent, the result is accomplished here in a different and better manner. Note that in Fig. 2, there is a chamber formed between the three walls of recess 17 and the wall 6 of member 3. This chamber is sealed off from the other recess 16 and is closed completely except for its connection 33 with the outlet port. The upper half of cylinder 11 is subjected to inlet pressure through the hole 32. The differential of these pressures is available, acting over a large area of the cylinder to raise the latter against spring 15 and move it into its upper and inactive position shown in Fig. 3. Thus, in effect, the cylinder functions also as a piston and the recess 17 as a cylinder for the purpose of moving the cylinder 11 to inactive position. As the cylinder 11 is moved upwardly, it presents an increasing area to the outlet pressure while the area subjected to inlet pressure diminishes, thus accelerating the movement of the cylinder into its inactive position. When the outlet pressure drops sufliciently, the cylinder 11 will be moved back into the Fig. 2 position by spring 15. Thus, a very elfective way of moving the cylinder 11 is provided and one which is exceedingly simple and can'be manufactured at relatively low cost due to the simplicity of the machining operations. The member 3 is bored from one axis, as and then moved slightly and bored again about the axis 6'. The recesses 16 and 17 may be cast in the periphery of the cylinder and the

passages

32 and 33 are simple drilled holes.

The invention thus provides an improved arrangement for shifting the cylinder of the pump from active pumping position to inactive pumping position by the application of hydraulic pressure to the external surface of the cylinder without necessitating the provision of a separate cylinder and piston in the pump housing for the purpose.

What is claimed is:

In a rotary-vane variable-capacity type pump, having an outer housing consisting of a pair of side wall members and an interposed member afiording a peripheral wall surrounding a chamber, the ends of which are formed by the inner faces of said side wall members, the peripheral wall of said chamber composed of two opposed semicylindrical sections the axes of which are spaced apart and two outwardly extending grooves, each interconnecting the adjacent ends of two semi-cylindrical sections, a stator comprising a hollow cylindrical member having coaxial inner and outer surfaces, 3. fulcrum for said stator mounted in one of said grooves, a spring-pressed plunger mounted in the peripheral wall of the housing tending to hold the stator in a first position, wherein one half of its outer cylindrical surface abuts one semi-cylindrical wall of said chamber, a rotor mounted within the stator and having radially movable vanes the outer edges of which engage the inner cylindrical wall of the stator, said rotor being disposed eccentrically of the stator when the latter is in said first position, and concentrically of the stator when the latter is in a second position wherein the other half of its outer cylindrical wall abuts the other semicylindrical wall of said chamber, said stator having diametrically-opposed recesses extending part way only around its periphery, said recesses being closed by said semi-cylindrical walls one when the stator is in said first position and the other when the stator is in said second position, said ends of said chamber having therein inlet and outlet ports communicating with the spaces between the stator and the rotor and its vanes, said hollow cylindrical member having therein passages one connecting one of said recesses to the inlet port and the other connecting the other of said recesses to the outlet port.

References Cited in the file of this patent UNITED STATES PATENTS 2,433,484 Roth Dec. 30, 1947 2,451,666 De Lancey Oct. 19, 1948 2,612,844 Grise Oct. 7, 1952 2,633,805 Haugdahl Apr. 7, 1953 2,742,861 OConnor et a1 Apr. 24, 1956