US2006237A - Hydraulic engine - Google Patents

Description

.fne-25, 1935. E. M. EYNARD Y m37 HYDRAULIC ENGINE 1 Filed March 24, 1934 3 sheets-sheet 1 June25f1935r mv-NARU 2,006,231;

HYDRAULIC ENGINE Filed March 24, 1954 -r 3 Sheets-Sheet 2 June 25, 1935. E. M. EYNARD HYDRAULIC ENGINE Filed March 24, 1954 3 Sheets-Sheet 3 Patented June V25,y 1935 UNITED STATES PATENT OFFICE v 2,006,237v o nYnaAUuc rincaro?.k l l r` Elysee Marius Eynard, Boulogne-Billancourt,"

France Aaaucafmn'LMahf2a 1934, seriarNo. 717,252 FranceApril 7,1933 H f s claims. (o1. 121-120) 'lh present invention is concerned with der vices. for transmitting'hydraulic power, of the kind in which .theprime mover discharges a iluid which is introduced, at constantydelivery, into a hydraulic motor controlling the member toV be driven and Whose. delivery, per; revolution may bevaried according to the load, wherebythe speed of the hydraulic motor is varied and it is possible.

to strike a balance between theload and the driving torque.

The invention ismore p'articularly concerned with a distributor for .suchatype of 'hydraulic motor. vSuch distributor is constituted by a slide valve the position of which. controls the delivery per revolutionjof the hydraulic 'motor and,.con-` sequently,. the speedof the driven member, one ofthe faces of said slide. .valvebeing subjected to the .action of a fluidV dischargedby the prime mover and brought to a] substantially constant predetermined 'pressure by a pressure control device,` while ,its other face'is subjected to .the same pressure reducedgfhoweverg'by theloss of head resulting from Vthe entry of the fluid into the motor and which depends onthe load. on the motor, so that'the position of the slide valve and,

likewisedepends on the load. i o

Othercharacteristics and -features of the invention will become apparent from the.. ensuing 30 panying drawings whereinzf- I Fig. l1 is a sectional elevation of rstlexnbodi? ment of a 'hydraulic' motor according 'to they invention. 4

Figs. la and 1b are'views of theycontrol cams Fig. 2 isa cross section onthe'line *IIvIoI of Figli.'` Fig 3v is a'y detail view of the automatic dis-5 .trlbutor. 40

Vapplication of the invention. y y

Fig. 5 is a sectionv along the-line V-V'of Fig. 4.

rods Bare-3a, 31a-3b, 3c-3c, connected in pairs. bythe braces da, 412,40. Qn saidrbraces act the` pistons ofy the motoriwhich, inthe example illustrated, are arranged .in groups of .threefpistons' disposedin Vstar formation. The rst of thefse 6c and so on. The pistons such as 5a, 6a, 1a',

consequently, the speed of rotationof said motor,

description taken with reference to.y the accom- Fig. 4 is @longitudinal section or a" modified.'

' Fig. 6 is a sectional 'elevation' of another-appligroups is designated 5a, 5b, 5e; the second 6a, 6b,

l etc., may act onthe brace 4a; the pistons such as 5b, 6b, 1b, etc., on the brace IIb;r thenpistons 6c, 6c, 1c, etc.,l on the brace 4c. It -will be observed that this arrangement is only given'by way of e`x`- A ample and that each set of pistons-might comprise 5 any number of pistons other than three; anequal" numberl of braces 4' would then be 'provided. Moreover, there may be any number-of sets'of pistons disposed in starformation.v Finally, the pistons 5 of the first set have ,beenillustrated 10 as 'being' of greater A diameterr than that of vthe pistons of the other sets,i but this designis cptional for the diameter may be the same for all pistons or may decrease from set tor set.,`

'This hydraulic motor receives fluid dischargedv 15- by any appropriatemeanasuch as a pump, ynot illustrated,l driven. by the motor whose power it is desired to transmit tothe crank vshaft I.

The distributing mechanism according' to the invention comprises for `each longitudinal group oi'opistons such as 5a, 6a, 'la ,v a! slide valve I I vin the form of a diierential piston, whose large piston I2 reciprocates in a cylinder I3 extending the length of the corresponding longitudinal row of pistons, while the .smallpiston' I Ireciprocates "25 in a cylinder I 5 in direct communication with the fluid' inlet pipeV le," j 1 In theductI'I which connects'the pipe I6 with the cylinder I3, is inserted a pressure-control device, the purpose of which isto bring the uid to the desired pressure andl 'which comprises a piston 20 on' which" acts a'calibrated spring 20a or any other mechanical, hydraulic or pneumatic restoring means. To reach'the vcylinder y I3, the discharged uid has to.' overcome the re- 35 sistance of vthe spring 20a, whereby said fluid is .brought tothe' desiredpressure. .Intlie duct I1v is likewise mounted an inlet valve I8, controlled by a distributing cam I9set on the shalt Said cam is common to the three inlet valves I8. The 40 cylinder vI3 communicates with the cylinders or'. the corresponding pistons through passages. ifa, 6'a,jetc. The cylinder I3v likewise communicates; with 'an outlet vpassage 2Ia in which is .mounted a. valve 2|. 'actuated by `asecond cam-.22. The cylinder I3 nally. communicates at-itsyleft en with a second outlet passage I8a. It will be observed that the slide valve 'I I is sub-A jected, on the fone liand,.in thecylinder I5 to the. 50 action of thev fluid arriving through the pipe I8 i and put under pressure by the pressure control device 20 and, on the' other hand, in the cylinder I3 to the action 'of the'lsame pressure reduced however, by' the loss* of head'due to the fact that 55" said cylinder I3 communicates ,with one or more ofthe cylinders of the pistons a, la, etc. Y

Y The apparatus operates in the following mannler: On starting,- the slide valve II is in its right end position (position of Fig. 1) in which theV cylinder I3 communicates solely with the cylinder of the piston 5a. Naturally, the cylinders of f rthe pistons 5b 5c ofthe same set communicate with the `corresponding distribution cylinders A I3.

Consequently, the pressure fluid acts Von the first" set of pistons 5a, 5b, 5c which rotate Ythe crank shaft I through the medium of the braces 4 and connecting rods 3. If the load on the crank shaft is such that the loss of pressure head in the cylin-` der I3, duev to the now of pressure fluid Ain the cylinders ofthe rlrst set of pistons', 5a, Ib, 5c, ex-.

actly compensates the dinerence of the surface area ofthe pistons I2 and I4 of the slide valve II,

said slide valve will remain stationary and only the first set of pistonswill operate rotating the *y crank shaft directly at the highest possible speed.'

*snouldtne load on` the 'crank shaft I increase., its speed and the speedoi' displacement of the. pistons 5 fall off, andthe loss of pressure head` in-each of lthe cylinders1ll decreases; On this account.' the pressure onthe distributor piston I2 increases andthe s lidefvaive I I `moves to the left thus uncovering the'passageA I'a, whereby the second set of pistonsfla is brought into circuit,... lILcOnsequent thereon, equilibrium 'is established between the pressure on the piston Il and that on the'piston I2,`the'slidevalve II will come to rest in this position in which 'the two first sets of pis.-l tonsi and i operateto, drive the shaft I., ata slightly lower speed than before; Should the loss of pressure l'ieadV still decrease due to the in-V crease ofV load, the 'slidefvalvel II uncoversl other passages such as 1a,8'a,etc., bringing a greater ynumber of pistons intocircuit, whereby the speed of the crankshaft I is correspondingly reduced.

Y suchfspeed beingthus proportional to the load LAes Vmine'according'to' their position, which depends on theload, the number of Y Y Y Sets of pistons which are brought intocircuit.` i'

YThe automatic distributing 'mechanism' accuraing to the invention may befappiied toother 'than Vpiston motors. A n Y Thus; inlFigs. ViV and -5`,V such mechanism has been shown 'applied to a hydraulic motor wherein each set of. pistons is replacedby a set of receiving gears 23a, 23h, 22e.' etc., on which the iluid acts'torotate them. j K

In the example illustrated, a distributor Il is provided'- for forward drive and a distributorl IIaV for reverse` drive,r andthe vpumphas been illus trated at. Said pump dischargesthewuid through Ythe-duct Il. Said fluid acts'on the pressurecontrol device 2li which, in this case, lik'e.Y

" wise Vserves to reverse the drive. In the figure, it

is represented-in the position for forward'drive, for, when it is displaced under the action 0I the iluid. :it admitsY a iluid into the cylinder Il but prevents access of the fluid (through the medium of its skirt I2)4 to thecylinder Ila, whichfor.

Y forward drivezserves for theexrhaust into anexhaust Areceiver formed by the chamber provided within Ythe central portion of the frame. yOn, the

other hand.V ifthe;V pressure control device III bcl Vcentrics 21 and 28.

9,000,937 Y, rotated through' 180, it is the cylinder Ila which receives the pressure fluid and theapparatus then operates in reverse.

The mechanism according to the invention may likewise be applied to motors of the type shown in Figs. 6 and 7, that is to say, which comprise a circular series of cylinders. set on the driving shaft I and in which reciprocate pistons 25 whose heads are connected to an eccentric memberl 26 whose eccentricity with ,respect to the axis of the shaft I may be varied by means of ec- Such eccentricity may be varied by imparting a relative angular displacement to the eccentrica 21 and 2B, for example, by means of the toothed pinions 29, 29a and the shaft 3o. The pinion 29a is fixed on theshaft .3l and controls the eccentric 28 through the instrumentality of the toothed sector 33a which is secured to the latter; the pinion 29 is. controlled by the pinion 28a and itself controls the sector 33 `secured to the eccentric 21. Such relative Vangular displacement "alters the throw ofthe Vouter eccentric 21 and [hence of the member 2l which is mountedL on saidrec'centricV 21 on ball f bearings al. 'rnisais a known 'typej of hydraulic motor. vWhen' the vvmechanism according tothe invention is applied to said motor, it is only hecessaryto providebetween the slidevalvev I I and the shaftv l0, a suitable n'iecohanieal connection through the medium v`of which the slide valve. II-

as it moves controls the relative angular displacementoi the eccentrica 21 and 28', and, consef quently, theposition'ofthemember' 20. On the' cylinders 2l and, 'consequentlmythe at"i which the driven shaft Iis rotated.f The meiy `chanical connection may be constituted by 'a2 plain rod $1 which exltiids kthe valve ,Il and which is connected infany vsuitable manner It'ofa'- lever`82'set on the shaft 20. l

`It is evident,omoreover,"that the invention might be applied to other types of hydraulic motors, the

essential characteristic of the invention residing ina slide valve which automatically takes upa position yof equilibrium in which the vmotor" .tof which it is applied rotatesatga 'speed correspond' ing to the load onit,

1.91am!! j 5 `1./ Incombination with' a motor adapted tobe driven by hydraulic power, adistributor for con-` trolling the Supply of pressure fluid to said motor. f'

comprising, in combination, a slidel valvev including two coupled differential pistonsz adaptedto movein corresponding cylinders, interconnected fluid 'inlets fofadiitting Vtlid to the v'oppositev ends of said cylinders, the larger' of Asaid cylinders communicating with said motor fnsuch" wise that while the smaller piston 'is subjected to theV full pressure of said iiuid the larger piston is sub# jecteu te 'and pressure reduced by the lass oriiead,

determined bye-the load on saidv motor, and pres-- sure control means mounted in theuiddnlet to said larger cylinder for` preventing admission of lfluid into sainz-larger cylindery until the pressure of the tluid has reached a predetermined value.

.2. Apparatus according ytolclaixn l. wherein the pressure control means* Ycomprise ya piston' valve anda` spring tending to hold said piston valve in position to cut oflthe admission of iluid exerted by said fluidon said pistonvalve. -f

3. Apparatus according to.claim-1,'in-corrilrinl'afl vto the larger ofsaid cylinders against Vthe thrust cular series of cylinders set on said drive shaft, pistons adapted to reciprocate in said cylinders, two superposed eccentric membersl mounted on said drive shaft and capable of relative angular displacement, an outer eccentric member surrounding the said two eccentric members and to which the heads of said pistons are connected,

whereby the relative angular displacement of said two eccentric members alters the throw of said outer eccentric member, and a linkage mechanism for coupling said two superposed eccentricmembers to vsaid slide valve to be controlled 5 by the displacementl ot the latter.

-ELYSEE MARIUS EYNARD.

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