US3295451A

US3295451A - Hydraulic power converter

Info

Publication number: US3295451A
Application number: US507167A
Authority: US
Inventors: James E Smith
Original assignee: Individual
Current assignee: Individual
Priority date: 1965-11-10
Filing date: 1965-11-10
Publication date: 1967-01-03
Anticipated expiration: 1984-01-03

Description

Jan. 3, 1967 J. E.- SMITH 3,295,451

HYDRAULIC PO WER CONVERTER Filed Nov. 10, 1965 4 Sheets-Sheet 1 INVENTOR.

BY JAMES .5. SM/ 777 Jan. 3, 1967 J. E. SMITH HYDRAULIC POWER CONVERTER 4 Sheets-Sheet 2 Filed Nov. 10, 1965 FICA FIG,6 4.9

INVENTOR. JAMES E. SM/TH w/ww I Jan. 3, 1967 SMITH 3,295,451

HYDRAULIC POWER CONVERTER Filed Nov. 10. 1965 4 Sheets-Sheet 3 FIG] . INVENTOR. JA MES E. .S'M/FH i fiiw Jan. 3, 1967 J. E. SMITH 3,295,451

' HYDRAULIC POWER CONVERTER Filed Nov. 10,1965 4 Sheets-Sheet 4 INVENTOR. JAMES E. SMITH United States Patent 25,25,451 HYDRAULIC POWER CONVERTER James E. Smith, 302 Plantation Drive,

Lake Jackson, Tex. 77566 Filed Nov. 10, 1965, Ser. No. 507,167 Claims. (Cl. 10349) The present application contains subject matter in common with my prior applications, Serial No. 175,767, new Patent No. 3,162,133, and co-pending applications, Serial No. 436,972 and Serial No. 420,028, filed December 21, 1964.

This invention relates to a hydraulic power converter for converting fluid pressure from one fluid to use in moving another fluid of different viscosity, different pressure, or different consistency. Specifically, the present invention relates to a hydraulic power converter for transmitting fluid pressure from one fluid to another fluid that may be of a diflferent nature, such as a slurry containing solids, without pulsation, and at a higher or lower pressure.

The present device is particularly useful for moving a solids laden slurry in pipe lines or for industrial uses where it is necessary to transmit liquids or liquified material that would damage the power producing pumps it passed directly therethrough at very high pressures. The present device can be used for the transmission of fluids containing wood chips, abrasive laden fluids and the like under high pressure without pulsation and without damaging the equipment involved.

One of the principal objects of the present invention is to provide a hydraulic power converter device for moving large volumes of viscous fluids at high pressure without pulsation.

Another object is to provide a device with few moving parts and operating on a substantially free piston plan whereby the hydraulic power fluid and the fluid passing through, or being transmitted by the converter, are kept separate so that abrasive slurries or fluids can be moved at high pressure without damaging the intricate hydraulic power pumps and supporting mechanism.

Still another object is to provide a device having timed inlet and outlet valves to give positive opening and closing of the valves when the converter is used to move lumpy slurries through pipelines.

Still another object is to provide a hydraulic power converter having a main rotating distributor tube for dis- 'tributing the hydraulic power fluid and the fluid or slurry passing through the converter simultaneously in timed relation to a series of power transfer cylinders with pistons reciprocating therein, positioned adjacent to the main distributor member and connected therewith through a series of ports.

Still another object is to provide a free piston converter utilizing a hydraulic power pump in combination with a trapped reservoir of captive fluid for transmitting a fluid at high pressure continuously without pulsation.

These and other objects and advantages will become apparent hereinafter.

The present hydraulic power converter comprises a main distributor member and a series of power transfer cylinders (preferably three in number) mounted adjacent to the main distributor member and connected therewith through a series of ports, each of the cylinders having free pistons separating a hydraulic power fluid and a captive fluid in a trapped reservoir behind or beneath the piston heads and interconnected among the cylinders at their lower ends.

The present converter uses fluid pressure to return the pistons within the cylinders to the top position, this return movement creating suction in the extended portion of the cylinder in which the ram or plunger portion re- Patented Jan. 3, 1967 ciprocates. This action is caused by said fluid, which is a captive fluid trapped within the confines of this portion of the converter. When hydraulic pressure is applied to the piston head from its outside hydraulic power source to force said piston to move downward in the cylinder, the fluid underneath this piston head, which is trapped around the annulus of the ram or plunger end, must be displaced into one or more of the other working cylinders. This feature provides positive means for returning the pistons, without any mechanical help, and the upward movement is in phase with the openings of discharge ports in the central valve tube. Therefore, the hydraulic fluid above the piston head is forced out and to pass through the fluid motor which rotates said tube, and this action causes the valve tube (or tubes if more than one is used) to rotate, a measured amount to open or close its ports in proper time with said fluid movement. This action provides the means for maintaining a constant overall suction and constant overall discharge. What is meant by overall is the sum total of all the working cylinders of the converter.

The invention also consists in the parts and in the arrangement and combinations of parts hereinafter described and claimed.

In the accompanying drawing which forms part of this specification and wherein like numerals and symbols refer to like parts wherever they occur; FIG. 1 is a fragmentary vertical sectional view through the converter showing the main distributor member and one of the pumping cylinders;

FIG. 2 is an enlarged fragmentary view partly in section showing the connection between the fluid pump and the distributor cylinder;

FIG. 3 is a view taken along line 33 of FIG. 2;

FIG. 4 is a diagrammatic sectional view showing the pumping cylinder laid out on a plane;

FIG. 5 is a sectional view taken along line 55 of FIG. 4; showing the pumping cylinders arranged around the periphery of the distributor cylinder and showing the arrangement of the exhaust valves in the distributor and the pumping cylinders;

FIG. 6 is a view similar to FIG. 5, but taken along lines 6-6 of FIG. 4 and showing the arrangement of the inlet valves in the distributor and the pressure fluid cylinders;

FIG. 7 is a fragmentary sectional view showing a modification of the present invention;

FIG. 8 is a diagrammatic arrangement showing the pumping system of the structure of FIGS. l-6.

FIG. 9 is a diagrammatic view of the pumping system of the modification shown in FIG. 7;

FIG. 10 is a fragmentary sectional view of another modification showing the inlet and exhaust valves for the pumped fluids;

FIGS. l115 are fragmentary sectional views of the distributor and pumping cylinders taken along lines 11 11 to 15-15 respectively of FIG. 1 showing the arrangement of the ports in the distributor cylinder and the pumping cylinders.

Referring now to the drawings in detail, it will be seen that the embodiment of the invention which has been illustrated comprises a hydraulic power converter 10 comprising a main cylindrical housing 11 which is closed by a bottom wall 12 and has a series of outwardly extending arms 13 to which are affixed power transfer cylinder hous ings 14 which also have closed bottom walls 15. A fluid motor 16 is mounted on the main housing 11 and has an output shaft 17 connected by appropriate gearing 18 (FIG. 2) to a main distributor member 19 rotatably mounted in the cylindrical housing 11.

The main cylindrical housing 11 is provided with hydraulic actuating or pumping fluid entrance port 20 aligned 3 with a series of longitudinal slots 21 around the periphery of the distributor member 19 to admit the pressure fluid continuously and smoothly to a pumping fluid inlet chamber 22 in the distributor member 19. The inlet ports are connected to a fluid pump 23 by a conduit 24.

The main housing 11 also is provided with a pumping fluid exit port 25 aligned with a series of longitudinal openings 26 in the distributor 19 to exhaust pumping fluid from an exit chamber 27 to a conduit 28 connected to the inlet side of the fluid motor 16. The exhaust side of. the fluid motor 16 is connected by a conduit 29 to a reservoir 30 and hence to the inlet side of the pump 23. Accordingly, as will be explained in more detail hereinafter, the pump 23 moves the pumping fluid through the converter 10 where it is utilized to move the pumped fluid. When the pumping fluid leaves the converter 10 it is utilized in the fluid motor 16 to rotate the main distributor member 19 and thence is returned to the reservoir 30 before the pump 23 again cycles it through the converter 10.

The main housing 11 also is provided with an entrance port 31 for pumped fluid connected to a conduit 32 and communicating with a pumping fluid inlet chamber 33 by a series of slots 34. The housing 11 also includes an exit port 35 for pumped fluid communicating with an exhaust chamber 36 by a series of aligned openings 37 and with an exit conduit 38. The pumped fluid inlet conduit 32 may be connected to a pipe line, to a reservoir or some other means of pumped fluid. Similarly, the pumped fluid discharge conduit 38 is connected to the appropriate destination of the pumped fluid.

Arranged around the outer periphery of the distributor housing 11 are a series of the pumping cylinder housings 14 preferably three in number. Each of the pumping cylinder housings 14 are provided with a main dam 39 through which is slidable the stem 40 of a double headed free piston 41 having a pumped fluid head 42 and a pumping fluid head 43.

Between the internal shoulder 44 of the pumping fluid head 43 and the opposed internal shoulder 45 of the dam 39 is defined an expansible trapped fluid chamber 46. Each of the pumping cylinders 14 is provided with a trapped fluid port 47 and is connected by means of a trapped fluid conduit 48 to the other pumping cylinders 14. This is shown in FIGS 4 and 11. Accordingly the trapped fluid is used to return the piston heads 43 to their uppermost position when pumping fluid is not being delivered to the expansible pumping fluid chamber 49 between the external face 50 of the cylinder head 43 and the internal face of the closure flange 13. The trapped fluid portions of the pumping cylinders 14 are in constant and continuous communication among all of the cylinders .14 and this allows more than one of the pistons 41 to move simultaneously in the same direction, thereby eliminating pulsation from the discharge line 38. Operation of the port arrangement to admit pumping fluid to more than one of the pumping cylinders 14 simultaneously will be described hereinafter.

The main distributor member 19 is rotatable in the housing 14 and is driven by the fluid motor 16 which operates from the pumping fluid, The gearing 18 is so arranged that the main distributor 19 makes a complete 360 rotation for a complete stroke of each of the pumping pistons 41. In other words, as the distributor member 19 rotates, pumping fluid is admitted to the pumping fluid chambers 49 alternately and pumped fluid is discharged from the expansible pumped fluid discharge chambers 51 defined between the Working face 52 of the head 44 and the inner surface of bottom wall 15.

Starting from the top of the distributor member 19 the ports in the distributor cylinder 19 and in the pumping cylinders 14 will be described. The pumping cylinders 14 are identical and each operates in like fashion but in timed sequence with the others as the distributor member 19 rotates so as to open and close the ports for the pumped fluid and the pumping fluid.

The distributor member 19 is provided first with the pumping fluid exit slots 26 aligned with the pumping fluid discharge port 25. These slots 26 are equally spaced around the periphery of the distributor member 19 and at. least one of them is in constant communication with the discharge conduit 28 to assure a constant supply of pumping fluid to the fluid motor 16. The next port in the distributor member 19 is the pumping fluid exhaust.

port 53 which extends over approximately 6 of the circumference of the distributor member 19 and is aligned with the pumping fluid discharge ports 54 in the pumping fluid chambers 49 of the pump cylinders 14. Thus as the distributor cylinder 19 rotates, the exhaust port 53 is alternately aligned with one or more of the cylinder ports 54 (FIG. 11) so as to admit pumping fluid to the exit chamber 27 from the pumping fluid chamber 49 on the intake or upward stroke of the piston 41.

Moving downwardly, the next port in the distributor member 19 is the pumping fluid inlet port 55 which extends over approximately /3 of the circumference of the distributor member 19 and is aligned With the pumping fluid inlet ports 56 in the pumping cylinders 14. When the

ports

55 and 56 are aligned (FIG. 12), pumping fluid is admitted to the chamber 49 and as the cylinder discharge port 54 is closed, the piston 41 moves down- Wardly in the pumping cylinder 14 in its discharge stroke. This forces the trapped fluid from the chamber 46 to another cylinder 14 (FIG. 11) where the discharge port 54 is open forcing that piston 41 upwardly on its intake 1 stroke, thus dischanging pumping fluid from the chamber 49 and sucking pumped fluid into the chamber 51.

Continuing downwardly, the pumping fluid intake slots 21 and then the pumped fluid intake slots 34 are encountered,

The next port in the distributor member 19is the pumped fluid intake port 57 which extends over approximately /3 of the circumference of the distributor member 19 and is aligned with intake ports 58 communicating with the pumped fluid chamber 51 of the cylinders 14. When the

ports

57 and 58 are aligned, fluid is admitted to the chamber 51 on the upward stroke of the piston 41. g

The exit ports 37 are spaced around the periphery of the distributor member 19 and aligned and in communication with the pumped fluid discharge conduit 38 to insure a constant flow of pumped fluid without pulsa-. 1

tion from the converter 10.

The last port in the distributor member 19'is the pumped fluid discharge port 59 which is aligned with dis-charge .ports 60 on the cylinders 14. The distributor port 59 extends over about /3 of the circumference and is adapted to be in communication with one or two of.

the cylinder discharge ports 60 at all times so as to in- The pumping piston face 52 is of less diameter than the piston face 50 so that the pressure of the pumped fluid is increased over that in the pumping fluid. An oil seal arrangement 61 (FIG. 1) comprising an oil conduit 62, a reservoir 63, a pair of spaced oil rings 64 and i a discharge conduit 65 provides a positive seal preventing the pumped fluid (which may contain abrasives) from passing the front face of the piston 44. Any that does pass is trapped in the space 66 between the body and 71 formed in the end of the rod 40. The piston head 52 engages a shoulder 72 in the cylinder 14, and is thereby separated from the end 68 of the rod 40 to pull oil into i the space 66 therebetween. When the piston 41 is dis- 1 sure a constant flow of pumped fluid from the converter.

charging, the oil is forced into the reservoir 63 and lubricates the cylinder wall and forms a positive seal against moving of the pumped fluid from the pumped fluid chamber 51 toward the trapped fluid chamber 46.

Operation Very' briefly, the operation of the present invention allows two of the pumping cylinders 14 to be discharging pumped fluid or pumping fluid simultaneously so as to avoid any interruption in the flow of these fluids from the converter and thus prevents pulsation in the output from the converte-r 10. The operation will be described with reference to FIGS. 1, 46 and 11-15. As the distributor member 19 rotates, the pumping fluid is discharged from the chamber 22 into the pumping fluid chamber 49 of a cylinder 14B (FIG. 4-6) through the inletport 56, the exhaust port 54 of this cylinder 14B being closed. This is the arrangement shown in FIGS. 1, 4-6 and 11-15. The arrangement shown in FIG. 1 corresponds generally to cylinder 14B of FIGS. 46, but FIGS. 4-6 are only to describe the operation schematically and are not accurately related to FIGS. 1 and 11-15. This causes the piston 41 to move downwardly forcing the trapped fluid out of the trapped fluid chamber 46 and into the corresponding chamber 46 of another cylinder 14C whe-re it moves that piston 41 upwardly. At the same time, the pumped fluid in the pumped fluid chamber 51 is discharged through the ports 60 and 59 into the chamber 36 and then through the ports 37 and into the discharge conduit 38. As the distributor. member 19 continues to rotate, the port overlaps the inlet port 56 of the next adjacent pumping cylinder 14A and starts to close on the inlet 56 of the pumping cylinder 14A (FIG. 6). Thus pumpin-g fluid is being admitted to two of the pumping fluid chambers 49A and 49B simultaneously. The chamber piston 41A starts to slow down as it reaches the bottom of its stroke and the piston 4113, being at the top of its stroke, starts to move downwardly in the discharge direction. The piston 41C, third cylinder, in the meantime is moving upwardly in its pumped fluid intake stroke. As the distributor 19 continues to rotate, the pumping fluid inlet .port 56 in the cylinder A is closed and the discharge port 54 is opened, so that the trapped fluid begins to be discharged from the cylinder 49A and is returned to the trapped fluid chamber46C of the cylinder 14C and the piston 41Cmoves upwardly discharging the pumping fluid through the now open port 54 and pulling the pumped fluid into the pumped fluid chamber 51. This cycle is repeated to continue the pumping operation. This operation gives an action to the pistons which is cushioned at the beginning and end of the stroke so that there is no interruption of the flow and thus no pulsation. The pistons actually begin to move in the return direction before reaching a positive stop.

The ports in the distributor member and the cylinders are so arranged and locate-d that as the fluid exit port closes, the fluid entrance port opens. Furthermore, the ports in the distributor member have a length such that they can overlap portions of corresponding ports in two adjacent cylinders simultaneously, although at times the distributor member ports encounter only one cylinder port.

A modification of the invention is shown in FIG. 10 which utilizes poppet valves 80 in the pumped fluid conduit 81 rather than the rotation of the distributor member 19 of FIG. 1 to control flow of pumped fluid into and out of the pumped fluid chambers 51a of the pumping cylinders 14a. In this arrangement, the operation of the pumping fluid portion of the rotating distributor member 19a is the same as that herein before described. The main casings 11a and the distributor member 19a terminate at what would be the top of the chamber 33 in the structure of FIG. 1. The pumped fluid discharge lines 81 are all connected to a common discharge conduit (not shown) designed to provide a continuous output from the converter 10a. The poppet valves 89 operate in the usual fashion so that when the piston head 42a is moving upwardly, the intake valve a is open, and the discharge valve 80b is closed, and when the piston 42a is moving downwardly on its discharge stroke, the inlet valve 8ia is closed and the discharge valve 80b is open.

Another modification of the present invention is shown in FIGS. 7 and 9 which is useful if only a portion of the pumping fluid is to be used in driving the fluid motor 16a. In this arrangement, the pumping cylinders 14 are provided with a fixed center conduit 82 slidably mounted in a well 83 in the pumping fluid piston head 43a. This arrangement is substituted for the corresponding piston head 43 of FIG. 1, and operates similarly except that the valve 84 is opened on the intake stroke of the piston 43a to let pumping fluid from the conduit 85 into the tube 82. On the outward stroke of the piston head 43a, the valve 84 closes and the fluid in the tube 82 is moved through the manifold 86 to the fluid motor 16a. The remainder of the pumping fluid is discharged from the chamber 49a through the port 54a to a conduit 87 by which it is returned to the reservoir 88. This arrangement is shown schematically in FIG. 9. In this diagram, a pump is omitted. The pumping fluid from the reservoir 88 is moved by the pump through the conduit 89 to the distributor 1% where it is passed by the port 56a to the chamber 4% and also by the conduit 85 (whose connection .to the conduit 89 is not shown, but is by a standard manifold arrangement) to the well 83.

Another modification shown in FIG. 7 includes the standard fill mechanism for the captive fluid chamber 45a which includes trip member 90 for allowing more captive fluid into the system from a reservoir when the head 43a engages the trip 90, and the trip 91 for discharging captive fluid from the chamber 46a when the trip 91 is engaged by the head 43a. This arrangement can be used with any of the structures shown.

Another advantage of the present invention lies in its use as a booster station in a pipe line. As is known, the fluid in a pipe line'loses pressure along its length. With the present invention a fluid containing abrasive solids (which would damage a conventional pump) can be boosted in pressure without losing the pressure remaining in the fluid. For example, the fluid may enter the pumped fluid cylinders at 2000 p.s.i. and to boost this to 5000 p.s.i., the converter adds only 3000 p.s.i. to the fluid. The pressure remaining in the fluid entering the converter is picked up by the trapped fluid through the piston and transferred to the operating cylinders.

Thus it is seen that the present invention provides a converter achieving all the objects and advantages sought therefor.

This invention is intended to cover all changes and modifications of the example of the invention herein chosen for purposes of the disclosure, which do not constitute departures from the spirit and scope of the invention.

What is claimed is:

1. A hydraulic power converter comprising:

(a) a source of pressurized hydraulic actuating fluid,

(b) main distributor inlet and exhaust ports communicating with the pressurized actuating fluid source,

(c) at least three power transfer cylinders, each of the cylinders having:

(1) a dam positioned therein, (2) a piston mounted for reciprocal movement in the cylinder, said piston including:

(a) a stem slidable through the dam, (b) heads on opposite ends of the pistons, (c) the piston heads, dam and cylinder defining expansible chambers between the heads and the ends of the cylinder and a trapped fluid chamber between the dam and the inner face of the head exposed to the actuating fluid,

(3) actuating fluid inlet and exhaust ports aligned with the distributor actuating fluid inlet and exhaust ports,

(d) means connecting at all times the trapped fluid expansi-ble chambers in the cylinders,

(e) means for alternately and in turn moving the distributor actuating fluid inlet and exhaust ports into and out of communication with the inlet and exhaust ports of each of the cylinders, and

(f) pumped fluid inlet and exhaust means communicating with the expansible pumped fluid chambers in the power transfer cylinders and timed with the operation of the pistons to deliver a continuous, uninterrupted non-pulsating output of pumped fluid from the converter. I

2. The structure of claim 1 wherein the inlet and exhaust ports are alternately gradually opened and closed with more than one of the pistons movable in the same direction simultaneously, and with the pistons accelerating and decelerating during their travel in the cylinders.

3. The structure of claim 2 including a main distributor member in which the distributor ports are located, said member being adjacent to the power transfer cylinders, and a fluid motor operated by the actuating fluid and having an output shaft connected to the main member for rotating the same.

4. The structure of claim 3 wherein the pumped fluid inlet and exhaust means are ports in the main distributor member and are aligned with corresponding ports in the power transfer cylinders. V

5. The structure of claim 1 including a separable head on the pumped fluid end of the piston, an oil seal means for effecting a positive seal between the pumped fluid and the trapped fluid to prevent contamination of the trapped fluid by the pumped fluid.

6. The structure of claim 1 including means for moving only a portion of the actuating fluid through the fluid motor.

7. The structure of claim 1 including means for maintaining the volume of trapped fluid in the system between predetermined levels.

8. The structure of claim 3 wherein the inlet and ex- (b) a fluid motor operated by the actuating fluid and operatively connected to the distributor member for rotating said distributor member, and

(c) the inlet and exhaust ports in the distributor member being of a length to intersect more than one corresponding port in the power transfer cylinders and wherein the ports are so located that an inlet,

port into a cylinder is closed as the exhaust port in said cylinder is opened.

10. The structure of claim 9 including pumped fluid inlet and exhaust ports in the main distributor member, and corresponding aligned ports in the cylinders, the distributor ports being of a length to intersect more than one corresponding port in the cylinders, and Where the cylinders are so located that an exhaust port is closed as the inlet port in said cylinder is opened.

References Cited by the Examiner UNITED STATES PATENTS 2,112,466 3 /1938 Maloon 6o .5,2 2,486,079 10/1949 Tucker 103. 49

FOREIGN PATENTS 518,840 2/1931 Germany.

EDGAR W. GEOGHEGAN, Primary Examiner.

Claims

1. A HYDRAULIC POWER CONVERTER COMPRISING: (A) A SOURCE OF PRESSURIZED HYDRAULIC ACTUATING FLUID, (B) MAIN DISTRIBUTOR INLET AND EXHAUST PORTS COMMUNICATING WITH THE PRESSURIZED ACTUATING FLUID SOURCE, (C) AT LEAST THREE POWER TRANSFER CYLINDERS, EACH OF THE CYLINDERS HAVING: (1) A DAM POSITIONED THEREIN, (2) A PISTON MOUNTED FOR RECIPROCAL MOVEMENT IN THE CYLINDER, SAID PISTON INCLUDING: (A) A STEM SLIDABLE THROUGH THE DAM, (B) HEADS ON OPPOSITE ENDS OF THE PISTONS, (C) THE PISTON HEADS, DAM AND CYLINDER DEFINING EXPANSIBLE CHAMBERS BETWEEN THE HEADS AND THE ENDS OF THE CYLINDER AND A TRAPPED FLUID CHAMBER BETWEEN THE DAM AND THE INNER FACE OF THE HEAD EXPOSED TO THE ACTUATING FLUID, (3) ACTUATING FLUID INLET AND EXHAUST PORTS ALIGNED WITH THE DISTRIBUTOR ACTUATING FLUID INLET AND EXHAUST PORTS, (D) MEANS CONNECTING AT ALL TIMES THE TRAPPED FLUID EXPANSIBLE CHAMBERS IN THE CYLINDERS, (E) MEANS FOR ALTERNATELY AND IN TURN MOVING THE DISTRIBUTOR ACTUATING FLUID INLET AND EXHAUST PORTS INTO AND OUT OF COMMUNICATION WITH THE INLET AND EXHAUST PORTS OF EACH OF THE CYLINDERS, AND (F) PUMPED FLUID INLET AND EXHAUST MEANS COMMUNICATING WITH THE EXPANSIBLE PUMPED FLUID CHAMBERS IN THE POWER TRANSFER CYLINDERS AND TIMED WITH THE OPERATION OF THE PISTONS TO DELIVER A CONTINUOUS, UNINTERRUPTED NON-PULSATING OUTPUT OF PUMPED FLUID FROM THE CONVERTER.