US2296647A

US2296647A - Hydraulic pressure booster

Info

Publication number: US2296647A
Application number: US381046A
Authority: US
Inventors: John H Mccormick
Original assignee: Racine Tool & Machine Co
Current assignee: Racine Tool & Machine Co
Priority date: 1941-02-28
Filing date: 1941-02-28
Publication date: 1942-09-22
Anticipated expiration: 1959-09-22

Description

p 1942- J. H. M CORMICK I 2,296,647

HYDRAULIC PRESSURE BOOSTER Filed Feb. 28, 1941 2 Sheets-Sheet 1 INVENTOR.

tva H- lacwaa.

BY QQ ML ATTORNEYS.

Sept. 22, 1942. J, H, MCCQRWCK 2,296,647

HYDRAULI C PRES SURE BOOSTER Filed Feb. 28, 1941 2 Sheets-Sheet 2 IN VENT OR.

ATTORNEYS.

Patented Sept. 22, 1942 U N l TED STAT E. S PAT E NT" QF-FICE HYDRAULIC PRESSURE BOOSTER J ohn' H. McCormick, Racine, Wis., assignor to- Racine' Tool & Machine Company, Racine, Wis., a corporation of Wisconsin.

Application February 28, 1941, Serial No. 381,046

4 Claims.

The invention relates to hydraulic pressure boosters.

The general object of the invention is to provide a combined pump and motor device of the differential piston type in which a pressure fluid at low pressure acting against the larger diameter of the piston is used to raise the pressure of an operating fluid, preferably a portion of the low pressure fluid, to the desired higher pressure. The pump and motor device of the present invention is double acting, and the pressure of the higher pressure fluid is practically continuous through the operation of an automatically operated reversing valve whose movements are positively controlled by'auxiliary valves which are in turn controlled both by each other, by the piston, and by the pressure of the motive fluid.

A further object of the invention is to provide a pump and motor of the type above described in which the entire area of the high and low pressure pistons may be used to drive the piston;

The invention further consists in the several features hereinafter set forth and more particularly defined by claims at the conclusion hereof;

In the drawings:

Fig. 1 is a vertical sectional view of a device embodying the invention in one of its operating positions;

Fig. 2 is a vertical sectional view similanto Fig. 1 showing certain modifications.

The combined motor and pump comprises a low pressure cylinder Sand high pressure cylinders 6, 6' alined therewith and with a double acting differential piston -'I having parts reciprocating in said cylinders The cylinder is stormed in a casing 8 and the cylinders 6 in end plates 9 and 9' secured in a fluid-tight manner to the casing 8.

A main piston type reversing valve I ll 'Works in he casing 8 having a low pressure supply conduit II, and passages I2, I2 respectively connecting opposite ends of the cylinder 5with pas-' sages or holes I3 in the cylindrical valve liner I4. The conduit I I connects with holes I5in said liner. The valve 8 has annular recesses I6 therein on opposite sides-of a central part I1 whereby the conduit II will connect with eitherthe passage I2 or the passage I2. Instead of being directly operated by the hydraulic fluid, the valve 8 has a lost motion connection through a rod I8, loosely mounted in it and of greater length, with hydraulically operated rams t9,- I9 workingin bores 20, 20 formed in the end plates 9 and 9' and alined with the bore in the liner I4.

Passage of hydraulic fluid to the bores 20 and 20 is through passagesZl and 2| formed in the respective end plates and each controlled by its own differential piston'type control valve 22 or The

control valves

22 and 22 work respectively in differentially alined bores 23, 24 and 23', 24', the bores Y23 and 23'kbeing of smaller diameter and having annular enlargements25, 26, and 21 and 25, 26, and 21' therein, respectively. The

enlargements

25 and 25 connectb'ycored passages 28" and 2B in'th casing 8 with the inlet passage I I, the enlargements 26*:and 26' connect with the passages 2I'laml 2| and the enlargements 2'! and 21' connect'with passages 29 and 29' which are connected with the exhaust or return connection to the fluid supply tank. A port 30 from the passage 2| connects through exterior piping 3| with a port 32 communicating Withthe bore 24; and a port 30" connects through exterior piping 3| with a port'32' communicating with the bore- 24'. The liner I 4 'has'exhaust'ports 33 and 33' which'connect withpermanent exhaust'chambers 34; 34' that in turn are connected by suitable piping with the supply tank.

For allowing any'leakage'from'the larger diameter parts of the

valves

22 and 22" to quickly escape to exhaust each of these valveshas a longitudinal passage 35 connected'by ports 36 and 31 wherebyleakage from the space adjacent bores 23 or 23' may escape through port 31, passage 35j and port-3B 'to the exhaust including the enlargement Z'I'or 21' and passage 29 or 29'.

In order to allow the low pressure fluid to act on the entire area of each end of the piston-I, the back end of each high pressure end is relieved to provide a space38 'whichis' connected by a diametrically disposed passage 39'with a centrally disposed passage 4|] leading to the high pressure bore of the

cylinder

6 or 6 whose outer end is controlled by a flat seatedsp'ring closed-check valve 4| or M, eachmounted to cooperate with a removable seatmember '42 in the passage 40 secured in position by a sleeve nut 43. Each check valve has a sleeve guide extension 44 provided with passages 4-5"adjacent the seating portion of said valve.

The high pressure bore 6' has passages"46'=:and 41 connected. to a high pressure outlet passage 48, and the high'pressureboret' has-passages 46 and 4'! connected to the high pressure outlet passage 48. A spring seated discharge check valve 49 controls the discharge from'th'e passage 41 to the passage 48, and a similar valve 49" controls the discharge from the passage 41' to the passage 48.

The drawing shows the device about to start on its pumping stroke toward the right, the space 38 in front of the left hand face of the piston I being filled with low pressure oil, some of which has passed by the check 4| to fill the cylinder space 6 in front of the high pressure portion of the piston This low pressure oil is being admitted to the device through the low pressure inlet II, holes I5, recess I6 in valve I0, ports I3, passage I2, space 38, and through passages 39 and 40 past check valve 4| to cylinder space 6' and its conmeeting passages which are under these conditions cut off from the high pressure outlet 48. At

the same time low pressure oil passes from the inlet I and passage 28' to enlargement 25' from which it proceeds through part of bore 23 and enlargement 26 to passage 2| and bore 24 acting on'th'e'part-of said valve 22 of larger diameter'and also connecting the smaller diameterportion of this; valve 22 through enlargements 26 and 2| and passage 20 with the exhaust or supply tank. At the same time the forward end of bore-24 is connected to the exhaust'through piping 3 I passage 2 I enlargements 26 and 21 and-passage;29; Under the conditions mentioned abovethe piston 'l'proceeds to move to the right forcing the fluid at the low pressure side of cylinder 5 adjacent the cylinder-6 out the exhaust through the passages I2, I3, and 33 and forcing the fluid in the high pressure cylinder 6 into the passages 46 and 41 past the discharge valve 49 and into thedi'scharge passage 48 until said piston strikes the inner end 50 of the valve 22 and shifts this valve to'the'right. When this occurs, the valve 22 moves to the same position relative to the cylinder 6 as *is shown in connection with-the valve 22' and cylinder 6. Under these conditions theenlarg'ements and 26 are connected to the low'pressure oil through the passage'28- and inlet I|,'so 'that'some of this oil may flow into the passage 2| to' the bore 20 in front ofthe ram'I9, and also'sorne of it will flow throughpipe'3l to the larger diameter'bore 24" and act upon the larger diameter part of the piston of the valve 22 causing it to be shifted from its leftward position shown in the drawings toward the right so as to bring its smaller inner end 50' into position to be struck by the piston as it nears the end of its stroke toward the leftandalso connect the passage 2|" and enlargement 26' with enlargement 2'! andpassage 29' to the exhaust or supply tank, thus'relieving the oil'pressure ahead of ram I9 andpermittingth'e low pressure oil flowing into th'e'forward'part of bore 20 to act on ram I9 and pin I8 so asto shift the reversing valve I0 toward the left. It'is also to be noted that'the connection of the valve 22 with the exhaust also connects the bore 24 through piping 3| with the exhaust or supply tank, so thatthere is no tendency for'the valve 22 to change the position into which it has'been shifted by the piston. As soon as there've'rsing'valve I0 reaches its leftward position; the low pressure oil "from passage II is admitted byvalve lflto'passage I2 while passage I2 is "connectedwiththe exhaust with the result that the piston I in" its right hand position has its right end acted upon by low przs'sure oil in the same way as that shown in the drawing on its left end, and its left end is relieved of pressure with the result that the piston is pushed from the right to the'left, and the oil in the bore 0 in front of the smaller diameter left end part of the piston I isforced through passages 46' and 41 past opened check valve 49 to the high pressure passage 48, and when the piston I completes its movement to the left, it shifts the valve 22' to the left to the position shown in the drawing to connect the bore 20' with the low pressure oil so as to shift the valve I0 to the position shown, and the cycle of operations is then repeated.

From the foregoing it will be noted that it is necessary to effect a complete movement of one of the

auxiliary valves

22 or 22 before the other is moved and that this latter valve is hydraulically moved and hydraulically held in a position to be struck and moved by the piston 1 before the reversal of the reversing valve can take place, and that while one auxiliary valve is hydraulically held in a tripping position by low pressure oil, the other auxiliary valve is held in a non-tripping position by suction or exhaust pressure on its larger diameter end. It will, therefore, be noted that the arrangement providesa hydraulic interlocking action between the two auxiliary valves 22, 22' and the reversing valve I0.

In some instances it is desired to use different hydraulic fluids for the low pressure motor' and the high pressure pump, and under these condi tions the low pressure oil is separate from the high pressure fluid, such as water, as shown in the apparatus of Fig. 2-in which the numeral I05 designates the low pressure cylinder and I06 and I06 the high pressure cylinderswith the differential piston I01 working in these cylinders, there being suitable packing glands 108 through which the high pressure end I09 and I09 of the piston I01 passes in order to prevent leakage between the high and low pressure cylinders. In this modified form the high pressure ends func-' tion as ordinary plunger type pumps, the suction stroke of the piston I01 drawing water or other press operating fluid past suction inlet check valve 60' into the pump chamber including the short pipe 6| and the delivery stroke of this piston I01 forcing the fluid in the cylinder I06 past a discharge check valve 62" into the high pressure pipe line 63. Similarly, the suction stroke of the piston I01 drawing water or other operating fluid past suction inlet check valve 60 into the pump chamber including the short pipe" GI and the delivery stroke of thi piston I01 forc-' ing the fluid in the cylinder I06past a discharge 3 check valve 62 into the high pressure pipe line 63.

The action of the high pressure end of the differential piston is, of course, dependent directly on the movement of the low pressure end by the low pressure hydraulic fluid whiohis effected in substantially the same manner -as the first'de-' scribed construction through the operation of a main reversing valve H0 and auxiliary'differential piston type valves I22 and I22 workingin the bores I23, I24 and I23,-I24,'respectively. The main reversing valv 0 works in aported liner I I4 and acts to direct the flow of low pressure hydraulic fluid from pipe II I either topipe:

I I2 connected with the right hand'end of the cylinder I05 or to pipe II2 connected to the left hand end of said cylinder I05-and'at the same time connect the other of these pipes ;-I I2,

2' with the exhaust passage I34 connected to the hydraulic fluid supply tank through any suitable piping not shown. The bore I23 has a low pressure port. I28, a-transfer port I26, and an exhaust port I29 communicating therewith. The valve I22 isadapted-to connectthe port I26with the exhaust port I29--in its leftward 'shifted'position or to connect port I26 with the port I28 in its rightward shifted position. Similarly, the

bore I23 has a low pressure port I28, a transferport I 26, and an exhaust port I29 communicating therewith. The valve I22 is adapted to connect the port I26 with the low pressure port I28 as shown in its leftward shifted position or to connect said port I26" with exhaust port I29 in its rightward shifted position.

As in the first described construction, the reversing valve has a lost motion connectionwith the rams II9and II9- working in bores I 20 and I20 in the valve casing I50 engaging the ends of a rod H8 which runs loosely through an axially extending bore in the valve I I0, said rams having stem extension passing through stufling boxes IOI at the ends of said casing. The bore I20 connects by a pipe I2I with the port I26, and a branch pipe I3I leads from an intermediate point of this pipe to the front end of the bore I24. The bore I20 connects by a pipe I2I with the port I26, and a branch pipe I3I leads from an intermediate point thereof to the front end of the bore I24.

The ports I23 and I28 lead into a common passage connected with a pipe III of low pressure oil or other suitable hydraulic fluid.

With the above arrangement, the piston II on the last part of its movement toward the left engages the projecting end of the valve I22 and shifts it to the left into the position shown in Fig. 2, thereby connecting ports I 28 and I26 together, so that the driving low pressure hydraulic fluid from pipe III will flow through pipes I 2| and I3I, thus bringing pressure fluid against the ram II9 to move the reversing valve I I0 from the position shown in Fig. 2 toward the left and bringing pressure fluid into the bore I24 to shift the valve I22 to the left to the position shown in the drawing. When this valve I22 is so shifted, the port I26 is connected with the exhaust port I29, and hence the bores I24 and I20 are connected to the exhaust through pipes I3I' and I2I with the result that there is nothing interfering with the shifting of the reversing valve IIO toward the left and the continued positioning of the valves I22 and I22 in the positions shown in the drawing until the piston I01 moves from the position there shown to the right until it strikes the projecting end of the valve I22. The piston is so moved to the right by the movement of the reversing valve IIO to the left so as to connect pipes I I2 and I I I together while pipe H2 is connected to the exhaust passage I34 and the supply tank connected therewith. During the movement of the piston I0'I toward the right, the hydraulic fluid in cylinder I06 drawn in past check valve 60 during the preceding leftward stroke is forced out of said cylinder past the check valve 62 to the pipe 63' at the desired high pressure which is determined by the ratio of the diameters of the small and large pistons of the differential piston I01. On this movement to the right the piston I09 draws in a new charge of hydraulic operating fluid past check valve 60 into cylinder I06. At the end of the travel of the piston III! to the right the positions of the control valves I22 and I22 are reversed from that shown in the drawing while the reversing valve H0 is shifted to the right to the position shown in Fig. 2 since shifting of the valve I22 to the-rightconnects-ports -I 26 and "I 28*togethe-r and to pipes I2I and I 3I which then-connectthe bore I20- of the reversing-valve mechanism and the bore I24 of the-pilot valve'I22' with the low pressure motive fluid frompipel I I, thereby first causing a shift of the valve I22-toward the right to connect the port I26 to the exhaustport I29 and through pipe I2I and I3'I' connect the forward end of bore I20-* of thereversing valve mechanismand the bore I24 for the-pilot valve I22 with exhaust, so that there-is then nothing to stop the shifting of the reversing valve-llfl from the left to the right to the position-shown, and at the same time holding the valve I22-inits rightward position. Shiftingof-the-valve--I I0=- to the position shown connects the-pipe l I2'-with the pressure fluid supply pipe III'and the pipe II2 with the exhaust "passage, so'thatthepiston I0! is drivento the-left to theposition shown in Fig. 2 while the right high pressure-piston I09 is on its suction and the left high pressure-piston I09 is on its delivery stroke. Thereafter; the cycle of operation is-repeated.

In this form of theinvention it is to be again noted that the reversing valve- IIO-cannotbe operated to cause a-reversal of thepiston' I01 until said piston reaches the end of its movement and the control or auxiliary valves are operated and that neither pilot valve I22 or I22 can be shifted during the intermediate travel of the piston and that the shifting of one controls the shifting to what may be termed the cooked position of the other.

It is also to be noted that the lost motion connections between the reversing valve and its small operating rams aid in the shifting of the neversing valve, as either one of them is in motion when it engages this valve and thus acts to overcome the inertia of the heavier reversing valve and promptly shift it to its reversed position. The lost motion connections also provide a certain time delay or lag in the operation of the reversing valve, so that the control valves will be in their desired positions when the movement of the reversing valve occurs.

The hydraulic pressure booster above described corresp0nds in its operation with that of the actuating pump for furnishing the low pressure fluid, so the boosters operation may be of variable or constant volume depending upon the actuating pump.

I desire it to be understood that this invention is not to be limited to the details of construction hereinbefore described except only in so far as such limitations are included in the ap ended claims.

What I claim as my invention is:

1. In a hydraulic booster having a cylinder, a motor piston operating in said cylinder and a reversing valve for alternately respectively connecting opposite ends of said cylinder with a source of hydraulic pressure fluid and exhaust, the combination with said piston and said valve of a pair of control Valves for said reversing valve, means for operating said control valves alternately by the piston as it reaches the end of its stroke, hydraulically operated means for returning said control valves, and means for hydraulically interlocking said control valves to prevent their movement except at the end stroke positions of the movement of the piston, said valves in turn preventing movement of the reversing valve until one of said valves has been operated and the other has been moved to a position for acutation by the piston on its return stroke.

2. In a hydraulic booster having a pressure cylinder, a, motor piston operating in said cylinder and. a reversing valve'for alternately connecting the opposite ends of the cylinder with a source of hydraulic pressure fluid and an exhaust, the combination with said piston and said valve of a .pair of control valves for said reversing valve, said control valves being disposable at the ends of the cylinder-in position to be alternately engaged and moved by the piston as it reaches the end of its stroke, hydraulically operated means for returning said control valves and means for hydraulically interlocking said control valves to prevent their movement except at the end stroke positions of movement of the piston, said valves in turn preventing movement of the reversing valve until one of said valves has been operated and the other has been moved to a position for actuation by the piston on its return stroke.

3. In a hydraulic booster having a cylinder, a motor piston operating in said cylinder, and a reversing valve for alternately respectively connecting the opposite ends of the cylinder with a source of hydraulic fluid under pressure and an exhaust, the combination with said reversing valve of actuating rams for shifting said valve havinga lost motion connection therewith so as to control the inlet and exhaust of pressure fluid to opposite ends of the cylinder, and control means controlled by the piston at the end of its stroke in both directions for controlling the operation of said rams.

4. In a hydraulic booster having a cylinder, a motor piston operating in said cylinder, and a hydraulically operated reversing piston type valve for alternately respectively connecting the opposite ends of the cylinder with a source of hydraulic pressure fluid and an exhaust, the combination with said piston and valve of a pair of oppositely disposed differential piston type control valves mounted to have a part of their reduced inner end project-inwardly into the-cylinder in the path of the piston for shifting movement thereby in one direction, said control valves provided with hydraulically operated rams for shifting'said valves in the opposite direction, differential diameter bores for said valves, passages interconnecting the larger diameter bore of one of the valves with the smaller diameter bore of the other valve, and passages controlled by said control valves'under the action of the piston for controlling the supply of hydraulic pressure fluid to operate said reversing valve.

JOHN H. MCCORMICK.

CERTIF ICATE OF G ORRECTI ON Patent No. 2,296,6h7. September 22, 19b2,

JOHN H. McCORMICK.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, first column, line 16, for 'bore 25" read -bore 25v-; page 1;, first eolumn, line 1, strike out "pressure"; and that the said Letters Patent should be read with this correction therein that the same may conform to the rec:- ord of the case in the Patent Office.

Signed and sealed this 27th day of October, A. D. 1311.2.

1 Henry Van Arsdale, (Seal) Acting Commissioner of Patents.