US2579670A

US2579670A - Hydraulic pressure transformer

Info

Publication number: US2579670A
Application number: US83206A
Authority: US
Inventors: Hjarpe Eric George
Original assignee: SKF AB
Current assignee: SKF AB
Priority date: 1948-04-02
Filing date: 1949-03-24
Publication date: 1951-12-25
Anticipated expiration: 1968-12-25
Also published as: FR983660A; GB665310A; CH274965A; BE488198A

Description

Dec. 25, 1951 HJARPE 2,579,670

HYDRAULIC PRESSURE TRANSFORMER Filed March 24, 1949 5 Sheets-Sheet l E? w a?" a hyww Dec. 25', 1951 E. G. HJARPE 2,579,670

HYDRAULIC PRESSURE TRANSFORMER Filed March 24. 1949 3 Sheets-Sheet 2 Fig.5

Dec. 25, 1951 H A 2,579,670

HYDRAULIC PRESSURE TRANSFORMER Filed March 24. 1949 3 Sheets-Sheet 5 Patented Dec. 25, 1951 HY DRAULIGPRES SURE TRANSFORMER -Eric Georg-Hjarpe, Goteborg, Sweden, assignorrto MAktiebolaget Swenska Kullager fabrikcn,JGoteborg,Sweden, a corporation of Sweden Application March 24, 1949, SeriaFN 0183 wInlSweden April 2, 1948 vl-Jnstance.rioraririving a mechanismnwhichfor'its Junction. requires a higher liquidspressureithan Since "the, quantity ofapressure .ithat; available.

illiquid consumed iswas a rule very vairiablef itl is l,necessaryiijthatlthe quantity of liquid i'shall' be variablefromthe maximumdownto nil.

Certain "devices which have been proposed" for this purpose have. been provided with a "relief valvethrou gh which'the surplus .liquidinotused for driving purposesinay escape. IAsdi'sadvanof" heat whichiis transferred toithe liquid," the viscosity. of which is hereby usually "considerably altered.

In other systems a part of the 'availablefiuid 'Iisus'ed'todrive1a:liquid motor; which is directly connected to a high'pressure pump. "lf themotor isof rotary type the ificiencrwill be' quite-low,

andthe effect Which-is lost:is'transformedto-heat,'

which in this case also"is-"-transferred* to "the liquid.

l Devices having"reciprocating pistons as hith-en to used" are-- rather" complicated and expensive;

ance-the pistonsare mutually mechanically interconnected; as is also the casewith the governing Val-ves. Such devices also have certain other disadvantages such as uneven delivery, etc.

The device" according to the 1 present invention is governed preferably --en'tirely by hydraulic -meansby valves which are also'hydraulically'governed. The -wholeaggregate will thus he simple and flexible and" there vill be h ai tlly any wear "on the parts.

' embodiment of "the-invention is showm on the accompanying drawings whereiflFigss 1 to 5 a-r l'i-ke' fna'gmentary sectional vie-ws showing the respective positions on the parts of the trans- "-iormer during different phases "of the cycle. The numeral I indicates the inlet line-ior a-pressm'e 'liqixidj-From the inlet line the fluid' fiovvs through 'I'hese'valvesare opene dlay the pressure of the liquid, .,permitting the liquid 'to--'obtain=-access througlr channels ll" and 42 to the minor cylinders 6 and I of a, pair ,of differential pistons, where it acts on the pistons 8-and 9 moveable win lthesei cylinders.

to assume their lower positions-Has long: as there are no other forces acting-upon-them. The pressure liquid. is also led from the inlet 1 to a, valve chamber IQ and to another'valve chamber H a'pair of-piston-valves 5 2 and I3.

the" position is thatshown in l fig ilithe Pliquid is led from thevalve chamber I through a-channe1-*I4-to' a'valve chamber l5. iII'IZhe; valve fchamber 16' at the'other endyoffthe pistonvar'lve The :pistonsxare thus caused I l3r-is in communication withanoutlet lhthron'gh eatchannel ll, atchamber 19min the valve 12. 'a channel: 35 an annulan channel 36-i-whichsurroundssthevalve l3 and a channel 34. MInuthe position shown 1311B, liquid-l. continues irorn lithe valve. chamber 1 l through-a1 channel: 20. toathe Working cylinder v,2 I -ofoneoof the :difierentia-l -pistons,'- where, it exertsa pressure'on. the piston 22- which may; forexampleybe five timesasgreat in as the pressure exerted by the liquid on the apistont 9, if the-rareas =of the pistonsare1asll 5zl. .erEquilihriumflwillt ltheref ore t not be. attained until until the galeton unit 9-22 hasmoved sofast-that the specific, pressure tinwther cylinder 1 ihaswincreasedrto five times the specific pressureloft/the liquid entering through-the. inlet duct l 'I he' liquid t in the smallerv cylinder I thus forced past. a ball valve 23 out winter a, ductlf24 I :leadingto a Working Hcylinderlonthelike.

w 'Ihc-,.. ball val-ves- 5.ancl -2 5 are kept closedlbyQthe higher liquid pressure. o Whenlthee biston unit 9422 ,hasnmovedw so far that (it ppensra channel a 26 leadingfinom. the cylinder 2 Into; a valve, chambenl'latostheright of :the valve L2, "the.-,liquidmis gasledrthrough this channel .toilthe said valve cham- Ll her: and forces the valve .1 2 towardsthe left. 'lTThis r movementfis.made possiblesince the valve chamcberwmratethe left endgof the valvemislinlcommunication with other. outlet 1 T ithrou'gh'. the ;channel :-3: l.29, the supper. partflliifl of thercylir'ider. andfthe Johanna-11 3 I. 'Th epposition'. is now that shown in Fig.2.

The displacement of Ithe valve 1 i 2 U; puts the val ve.chambe1 l SIin communicationtvvitli the inlet I. and pressure liquid hows" froin the inlet 'throu'glfthe channel l8 to the valve: chvaxnberil 6 and forces the valve 13 to the rightwhiclris ,Apos'sible. since (the valve-chamber 15 incomrmimication witlfthe outleti'l'l through thehhan- 40 nel" 14, the valvecharnber Ill; a-channeltzleading. from the latter to an annular channel33 which surrounds the valve13 and the channel" 34. The. displacement of the valve 'i3"('seeFig."3) puts' a valve chamber 3'! the-valve" I 3" in communi'cation' with the inlet IV and thecylinder 2| @is put in communication with "the outlet 'l I through .itherfchannel 20, valve chamber l l,"=an annular channel 36 surroundingtthe valve 13 and the 'ch'annerii l. The pressurefliquidnow flows from the channel 1 through the? valve chamber I 9, channel"2,valve chamber 31"ancl' a channel 3 Bfito a workingcylinder 39',"Where "it exerts pressure .on a piston iflflwhi'ch' is connected to-the bistonl 3. The'pressure liquid then forcesithe piston unitflflfiin a' direction towardsthemmlidBl" B'in" which the specific pressure increases LtO" five'times the pressure of "the liquid entering '5 through the inlet 1. Thei liqhidin the" cylinder G is forced outofthe cylinder;past'the'ballvalve 1 2 5.. and" out new the ,ductf 24f "leading" tothe; place that communication is opened between the cylinder 39 and the channel 29, liquid flows through this channel to the valve chamber 28 and forces the valve I2 towards the right back to its ori inal position, which is possible since-the valve chamber 2! at the other end of the valve by the previously mentioned downward movement of the piston unit 9-22 has been put into communication with the outlet ll-thrcugh the channel 2%, a channel 43 which connects the

cylinder parts

30 and 44, the upper part 44 of the cylinder, the

channel 43, the cylinder part 39 and the channel3l.

By the displacement of the valve l2 towards the right (Fig. 4) the valve chamber ID has again been put into communication with the inlet i and the liquid flows through the channel 14 to the valve chamber I5 and displaces the valve I3 back, to its original position, since the valve chamber [6 is again in communication with the outlet I! through the channel N3, the valve chamber 19, the channel 35, the annular channel 36 and the channel 34. The position of the valves is now that shown in" Fig. 5. The liquid now again flows from the inlet I through the valve chamber ID, the channel 2, the valve chamber II and channel to the cylinder 2| and displaces the piston unit 9--22 upwards so that the specific 5 pressure increases in the cylinder 1 to the higher 'pressure and holds the ball valves 5 and ,closed, the liquid passing the ball valve 23 into the duct 24. The pressure in the cylinder 6 will bethe same as that in the inlet I and forces the piston unit B-- in the direction from the cylinder 6, since the cylinder 39 is again in communication with the outlet I! through the channel 38, valve chamber 31 and channel 34. The position of all parts is now once more that shown in Fig. 1.

The working cycle described above is contin- Tuously repeated as long as liquid is removed from the outlet duct 24. I'he speed of the piston units 9-22 and 6-40 is governed by the liquid consumption aslong as the capacity of the apparatus is not exceeded.

In order to prevent momentary drops in pressure inv the duct 24 when the valve I3 is reversed from one end position to the other the valve chamber H and 31 in the valve are never out ofi from the inlet at the same time. In other words the cylinders 2| and 39 are never pressureless simultaneously. 7

. When the device is used for feeding machines with very considerable variations in liquid consumption, for instance machines having alternately a slower feed and swift reverse it is of advantage to introduce a reversing valve between the device and the machine for automatically connecting the machine to the high pressure line or the low pressure line as required. For quick maneuvering when the consumption is great but the pressure not high, the machine is thus automatically connected directly to the low'prestionary. When the machine is running with ordinary feed during the working phase when higher pressure is required but the liquid consumption is much lower it is automatically connected to the high pressure line from the apparatus.

Having thus described my invention I claim and desire to secure the following by Letters Patent:

1. A hydraulic pressure transformer having a. plurality of difierential pistons, each reciprocating in a low pressure cylinder and a high pressure cylinder, means for putting the low pressure cylinders into intermittent communication with a primary duct for pressure liquid and means for intermittently putting the high pressure 'cylinders. alternately into communication with a low pressure duct such as the said primary duct and a high pressure duct, the movement of the said differential pistons being controlled by automatically controlled governing means in such a way that liquid is always being delivered from at least one of the high pressure cylinders, the movements of the said governing means being hydraulically controlled by the movements of the said differential pistons.

2. Hydraulic pressure transformer according to claim 1, characterized thereby that each high pressure cylinder is provided with a check valve, through which it is intermittently put into communication with a common pressure line.

3. Hydraulic pressure transformer according to claim 1, characterized by a check valve between the low pressure duct and the high pressure cylinder of the differential piston.

4. Hydraulic pressure transformer according to claim 3 characterized thereby that each high pressure cylinder is provided with a check valve through which the cylinder is intermittently put into communication with a common pressure line.

5. Hydraulic pressure transformer according to claim 1 characterized by'piston valve means for distributing the fluid to the low pressure cylinders.

6. Hydraulic pressure transformer according to claim 1, characterized thereby that the control means includes channels from the low pressure cylinders, the mouths of the channels being positioned so as to be uncovered to the piston actuating hydraulic pressure only when the pistons have reached predetermined positions in the pressure strokes.

7. Hydraulic pressure transformer accord n to claim 6 wherein the piston valve means is operatively connected by channels to the low pressure cylinders, the mouths of the channel being positioned so as to be uncovered to the piston actuating hydraulic pressure only when the pistons have reached predetermined positions in the pressure strokes.

ERIC GEORG HJARP REFERENCES CITED The following references are of record in the file of this patent:

- UNITED STATES PATENTS Number Name Date 1,451,303 Mitchell Apr. 10, 1923 1,600,384 Aikman Sept. 21, 1926 2,231307. Wallacef Feb. 11, 1941 2,279,364 Cadbury Apr. 14, 1942 2,293,076 Ponting Aug. 18, 1942 2,340,929 Cadbury Feb. 8, 1944