US3597116A

US3597116A - Fluid-powered pump

Info

Publication number: US3597116A
Application number: US848148A
Authority: US
Inventors: Ralph B Tilney
Original assignee: Alco Controls Corp
Current assignee: Alco Controls Corp
Priority date: 1969-08-07
Filing date: 1969-08-07
Publication date: 1971-08-03
Anticipated expiration: 1988-08-03
Also published as: DE2037929A1; JPS4837523B1; GB1312518A; CA922970A; FR2056757A5

Abstract

A fluid-powered pump comprising four-way slide valves with fluid conduits connecting the slide valves in a closed circuit. Highand low-pressure fluid connections to the fluid conduits to cause the slide valves to actuate one another in series in a continuously repeating cycle within the closed circuit. The slide valves may be used to pump other fluids from low-pressure supply areas to high-pressure use areas, such as to pump liquid to the boiler in an absorption-type refrigeration system.

Description

United States Patent Ralph B. Tllney Clayton, Mo.

Aug. 7. 1969 Aug. 3. 1971 Alco Controls Corporation St. Louis, Mo.

inventor Appl: No. Filed Patented Assignee FLUID-POWERED PUMP 5 Claims, 2 Drawing Figs.

US. Cl.... 417/344 Int. Cl F04b 17/00 Field of Search 103/49;

References Cited UNITED STATES PATENTS 6/1960 Moeller et al 103/49 FORElGN PATENTS 158,295 5/1953 Australia Primary Examiner-Robert M. Walker A!!0rney Kingsland, Rogers, Ezell, Eilers & Robbins ABSTRACT: A fluid-powered pump comprising four-way slide valves with fluid conduits connecting the slide valves in a I closed circuit. Highand low-pressure fluid connections to the fluid conduits to cause the slide valves to actuate one another in series in a continuously repeating cycle within the closed circuit. The slide valves may be used to pump other fluids from low-pressure supply areas to high-pressure use areas, such as to pump liquid to the boiler in an absorption-type refrigeration system.

FLUID-POWERED PUMP BRIEF DESCRIPTION OF THE INVENTION In this fluid-powered pump, a closed circuit of four-way valves is provided. Preferably there are three valves. Each four-way valve has a sliding spool formed with lands on a stem. Fluid chambers are defined by grooves between adjacent lands within the confines of the housing. At the ends of the spool, there are pumping chambers through which another fluid may be pumped as the spool reciprocates. A separate piston is reciprocative within each pumping chamber. One end of each piston contacts the spool and the other end of the piston is exposed to a port. Fluid conduits connected through the housing wall are alternately exposed to different ones of the fluid chambers that are defined by the grooves, depending upon the position of the spool. The chambers in the spool ofa first valve are connected by these conduits to the ported ends of the pistons of a second valve; the chambers of that second valve are connected by similar conduits to the ported ends of the pistons ofa third valve, and so forth. Finally, the chambers of the last valve are connected to the ported ends of the pistons of the first valve to complete and close the cycle. In addition, the chambers defined by the grooves are individually connected to sources of high and low-pressure fluids. By alternately porting these conduits between the chambers as the spools reciprocate and by maintaining the different chambers in constant communication with the high and low-pressure fluid sources, the spools will reciprocate in continuous succession. Thus, for a three-valve system, for example, when the first spool moves to one end, such as the left end of its housing, the spool of the second valve moves to the right and the spool of the third valve moves to the left. When the spool of the third valve moves to the left, it moves the spool of the first valve to the right thereby changing the porting of fluid to move the spool of the second valve to the left and thereafter cause movement of the third valve to the right. In this manner, reciprocation of the spools continues so long as the different pressure fluids are supplied to the fluid chambers.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of the fluid-powered pump. FIG. 2 is a fragmentary schematic diagram of one end of a modified form of valve that may be incorporated in the pump.

DETAILED DESCRIPTION OF THE INVENTION This fluid-powered pump comprises a plurality of fourway valves. In this description and in the drawing, three

such valves

11, 12, and 13 are described and shown, but the fluidpowered pump will operate with two or more valves. The

valves

11, 12, and 13 are of identical construction.

Each

valves

11, 12, and 13 has a valve body 15 that provides a slide chamber 16 and left and right

end piston chambers

17 and 18. The cross-sectional area of the slide chamber 16 is greater than that of the

piston chambers

17 and 18, although these relative dimensions my be varied depending upon the desired relationship between pumping rate and pumping pressure, as will be described.

A spool or slide 19 is reciprocative within the slide chamber 16, The slide 19 has a stem 20 and four

lands

21, 22, 23, and 24. O-rings (not shown) or other suitable seals are provided between the

lands

21, 22, 23, and 24 and the inner wall of the slide chamber 16 so that substantially no leakage occurs past any ofthese lands.

The volume within the housing 15 to the left of the land 21 constitutes a left end pumping chamber 26. The volume within the housing 15 to the right of the land 24 constitutes a right end pumping chamber 27. The volume within the housing 15 between the

lands

21 and 22 constitutes a low-pressure return chamber 28. The volume within the housing 15 between the

lands

23 and 24 and surrounding the stem 20 constitutes another low-pressure return chamber 29. The volume within the housing 15 between the

lands

22 and 23 and surrounding the stem 20 constitutes a high-pressure supply chamber 30.

A piston 32 is slidable within the piston chamber 17 and into the left end pumping chamber 26. The piston has end faces 33 and 34 with one face 34 bearing against the left end of the slide 19. Another piston 35 is slidable within the piston chamber 18 and into the right end pumping chamber 27. The piston 35 has

end faces

36 and 37 with one end face 36 bearing against the right end of the slide 19.

A tube 42 that leads from a source (not shown) of highpressure power fluid opens into the high-pressure supply chamber 30.

Tubes

43 and 44 that lead to low-pressure power fluid receivers (not shown) are connected from the low-

pressure return chambers

23 and 29. Thus, the chamber is always in constant communication with the high-pressure power fluid source and the

chambers

28 and 29 are always in constant communication with low-pressure power fluid returns.

Two

tubes

45 and 46 lead from a source (not shown) of lowpressure fluid that is to be pumped to an area (not shown) of higher pressure. This low-pressure fluid source may be the same as or different from the low-pressure fluid source already mentioned. The area of higher pressure to which the pumped fluid is to be delivered is different from the high-pressure fluid source already mentioned. There are

check valves

47 and 48 respectively in the

tubes

45 and 46, and the

tubes

45 and 46 open to the

respective pumping chambers

26 and 27.

Other tubes

49 and 50 lead to the last-mentioned area (not shown) of higher pressure to which the low-pressure fluid is to be pumped. The

tubes

51 and 52 open from the

pumping chambers

26 and 27, respectively. There are

check valves

51 and 52 in the

tubes

49 and 50 respectively.

Since the four-way valve 12 and the four-way valve 13 are identical to the four-way valve 11, they will not be described in detail. The identical parts of these valves have been given identical reference characters, with a single prime applied to the numbers for the valve 12 and a double prime applied to the numbers ofthe valve 13.

There is a tube 56 that communicates with the slide chamber 16 of the valve 11 and with the left end piston chamber 17 of the valve 12. Another tube 57 communicates with the slide chamber 16 of the valve 11 and with the right end piston chamber 18 of the valve 12. When the slide 19 of the valve 11 is in its extreme left-hand position, the tube 56 communicates with the high-pressure power fluid supply chamber 30 and the tube 57 communicates with the low-pressure power fluid return chamber 29. As the slide 19 slides to the right, the piston 22 moves past the tube 56 to block communication between the tube 56 and the high-pressure power fluid supply chamber 30 and to thereafter establish communication between the tube 56 and the low-pressure power fluid return chamber 28. The piston 23 moves to block communication between the tube 57 and the low-pressure power fluid return chamber 29 and to thereafter establish communication between the tube 57 and the high-pressure power fluid supply chamber 30.

A tube 58 communicates with the slide chamber 16 of the valve 12 and with the left end piston chamber 17" of the valve 13. A similar tube 59 communicates with the slide chamber 16' of the valve 12 and with the right end piston chamber 18" of the valve 13. When the slide 19' of the valve 12 is in the leftmost position, the tube 58 communicates with the highpressure power fluid supply chamber 30 and the tube 59 communicates with the low-pressure power fluid return chamber 29'. When the slide 19 is in the rightmost position, the tube 58 communicates with the low-pressure power fluid return chamber 28 and the tube 59 communicates with the highpressure power fluid supply chamber 30.

A tube 60 communicates with the slide chamber 16" of the valve 13 and with the left end piston 17 of the valve 11. Another tube 61 communicates with the slide chamber 16" of the valve 13 and with the right end piston chamber 18 of the valve 11. The

tubes

60 and 61 alternately communicate with the high-pressure power fluid supply chamber 30 and with the respective low-pressure power fluid return chambers 28" and 29" as the slide 19" reciprocates between its left and right positions.

OPERATION High-pressure power fluid is continuously supplied to the high-pressure power fluid supply chamber 30 of the valve 11, to the high-pressure power fluid supply chamber 30' of the valve 12, and to the high-pressure power fluid supply chamber 30" of the valve 13. The low-pressure power

fluid return chambers

28, 28', and 28" and 29, 29', and 29" of the

valves

11, 12, and 13 are in constant communication with demand areas for low-pressure power fluid through the

respective tubes

43, 43', and 43" and 44, 44, and 44". The

tubes

47, 47', and 47" and 48, 48, and 48" which communicate with the left and

right pumping chambers

26, 26', and 26' and 27, 27', and 27" of each of the three valves ll, 12, and 13 are in constant communication with the source of low-pressure fluid to be pumped to a higher pressure area. The

tubes

49, 49', and 49" and 50, 50', and 50" are in constant communication with the higher pressure area to which fluid is to be pumped.

When the slide 19 of the valve 1 1 moves to the left, communication between the high-pressure power fluid supply chamber 30 and the tube 56 is established and communication between the low-pressure power fluid return chamber 29 and the tube 57 is established. Hence, the high-pressure power fluid supplied through the tube 56 to the left end piston chamber 17' of the valve 12 drives the piston 32', the slide 19, and the piston 35' of the valve 12 to the right. As the slide 19 is driven to the right, it forces pumped fluid from the right end pumping chamber 27 to the outlet tube 50, the check valve 48', preventing pumped fluid from flowing back through the tube 46'. Likewise, pumped fluid is drawn from the tube 45 into the left end pumping chamber 26. The check valve 51' prevents pumped fluid from flowing from the tube 49'.

As the slide 19 of the valve 12 is driven to the right, communication between its high-pressure power fluid supply chamber 30' and the tube 59 is established and communication between its low-pressure power fluid return chamber 28 and the tube 58 is established. Hence, the slide 19" of the valve 13 is driven to the left. As the slide 19" of the valve 13 is driven to the left, communication is established between its high-pressure power fluid supply chamber 30" and the tube 60 and communication is established between its low-pressure power fluid return chamber 29" and the tube 61. This supplies high-pressure power fluid through the tube 60 to the left end piston chamber 17 of the valve 11, driving the slide 19 of the valve 11 to be the right. With the'valve slide 19 of the valve 11 being driven to the right, reversal of operation of the valve 11, followed by reversal of operation of the valve 12 and reversal of operation of the valve 13 takes place.

Thus, when the slide 19 of the valve 11 is driven to to the right, the porting of the

tubes

56 and 57 to the high-pressure power fluid supply chamber 30 is reversed so the slide 19 of the valve 12 is now driven to the left. As a result, the porting to the

tubes

58 and 59 from the high-pressure power fluid supply chamber 30' of the valve 12 is reversed and the slide 19' of the valve 13-is driven to the right. When the slide 19" is driven to the right, its porting to the

tubes

60 and 61 is again reversed to again drive the slide 19 of the valve 11 to the left. Thus, as long as high-pressure power fluid is supplied to the

tubes

42, 42', and 42" and the

tubes

43, 43, and 43" and 44, 44', and 44" are connected to low-pressure power fluid demand areas, the

slides

19, 19', and 19" will continue to reciprocate, constantly pumping pumped fluid through the pumping

chambers

26, 26', and 26" and 27, 27', and 27".

From the foregoing, it is apparent that in this fluid-powered pump, one power fluid stream is used to pump another pumped fluid stream. External fluid seals are eliminated because the pump is a closed system. The troublesome seals that must be used to seal the shafts of motor-driven pumps are not required in this fluid-powered ump. The pumping action WIII start when power fluid is supp red regardless o the initial positions of the slides, and will continue so long as the power fluid continues to be supplied.

In an absorption-type refrigeration-system, this pump may be used to pump low-pressure liquid into the boiler or vapor generator against the high pressure existing in the vapor generator. Other fluids that must flow against a high-pressure resistance may be pumped by this fluid-powered pump.

The diameters of the

pistons

32, 32', and 32" and 35, 35', and 35" relative to the diameters of the pistons on the

slides

19, 19', and 19" may be varied to vary the pumping pressure and rate of flow of the pumped fluid. As the diameters of the

pistons

32, 32 and 32" and 35, 35', and 35 are increased, the pumping rates will be increased, but the pumping pressures will be decreased. FIG. 2 illustrates a modification wherein A subscripts have been added to numerals which designate parts similar to those shown in FIG. I. In FIG. 2, the piston 32A and its counterpart at the other end of the valve 11A are of larger diameter than the

pistons

21A, 22A and the other pistons of the slide 19A. In the valve of FIG. 2, the rate of flow of the pumped fluid is increased but the pumping pressure is reduced.

I claim:

1. A fluid-powered pump comprising a first slide valve, a second slide valve, and a third slide valve, each valve comprising: a housing with a slide reciprocative therein, a pumping chamber in each slide valve for causing pumping of a fluid through the pumping chamber as the slide of the slide valve reciprocates, a conduit for delivering low-pressure fluid to each pumping chamber, a conduit for delivering fluid from the pumping chamber to a high-pressure receiver, means defining high and low-pressure power fluid chambers in each slide valve, movable with movements of theslide thereof, a highpressure power fluid source, a low-pressure power fluid return, means communicating the high-pressure power fluid source to the high-pressure power fluid chamber, means communicating the low-pressure power fluid return to the lowpressure power fluid chamber, means to connect the valves in a closed cycle comprising: conduit means for individually connecting the power fluid chambers of one slide valve with separate pressure-responsive portions of the slide of another slide valve in a serial closedcircuit, means in each valve to port the last-named conduit means to alternate connections thereof to the high and low-pressure power fluid chambers as the slide reciprocates, and means responsive to the said alternating of connections to cause closed circuit reciprocation of the slides and consequent pumping of fluid through the pumping chambers.

2. The pump of claim 1 wherein the low-pressure power fluid chamber comprises a divided chamber with portions on opposite sides of the first power fluid chamber.

3. The pump of claim 1, wherein the cross-sectional areas of the pumping chambers are smaller than the internal cross-sectional areas of the slide housings.

4. The pump of claim I wherein the cross-sectional areas of the pumping chambers are greater than the internal cross-sectional areas of the slide housings.

5. The pump of claim 1 including a piston in each pumping chamberhaving one end bearing against the slide and the opposite end constituting a said pressure-responsive portion.

Claims

1. A fluid-powered pump comprising a first slide valve, a second slide valve, and a third slide valve, each valve comprising: a housing with a slide reciprocative therein, a pumping chamber in each slide valve for causing pumping of a fluid through the pumping chamber as the slide of the slide valve reciprocates, a conduit for delivering low-pressure fluid to each pumping chamber, a conduit for delivering fluid from the pumping chamber to a high-pressure receiver, means defining high and low-pressure power fluid chambers in each slide valve, movable with movements of the slide thereof, a high-pressure power fluid source, a lowpressure power fluid return, means communicating the highpressure power fluid source to the high-pressure power fluid chamber, means communicating the low-pressure power fluid return to the low-pressure power fluid chamber, means to connect the valves in a closed cycle comprising: conduit means for individually connecting the power fluid chambers of one slide valve with separate pressure-responsive portions of the slide of another sliDe valve in a serial closed circuit, means in each valve to port the last-named conduit means to alternate connections thereof to the high and low-pressure power fluid chambers as the slide reciprocates, and means responsive to the said alternating of connections to cause closed circuit reciprocation of the slides and consequent pumping of fluid through the pumping chambers.

4. The pump of claim 1 wherein the cross-sectional areas of the pumping chambers are greater than the internal cross-sectional areas of the slide housings.

5. The pump of claim 1 including a piston in each pumping chamber having one end bearing against the slide and the opposite end constituting a said pressure-responsive portion.