US2448347A - Hydraulic pump control - Google Patents

Description

Aug. 3 1, 1948. L. BEEH HYDRAULIC PUMP CONTROL 5 Sheets-Sheet 1 Filed im.y 1a, 1944 Aug. 31, 194s. y L, ,BEEHv 2,448347 HYDRAULICPUMP CONTROL Y INVENToR. LOU/S BE E H BY w1/.M

Aug. 3l, v1948.

5 Sheets-Sheet 3 Filed Oct. 18, 1944 INVENTOR. LOU/S BE E H BY Maz; I'. M

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HYDRAULIC PUMP CONTROL Filed Oct. 18, 1944 5 Sheets-Sheet 4 FIG. 7.

INVENTOR. LOU/ 5 BE' E H BY ma 51M 1917' ORNE Y 5 Sheets-Sheetl 5 F/G. a;

L. BEEH HYDRAULIC Puur commer.

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Filed 0d.. 18, 1944 Patented Aug. 3l, 1948 l UNITED STATES PATENT oEElcE HYDRAULIC PUMP CONTROL Louis Beeh, Long Meadow, Mass., assigner to Bulova Watch Company, Inc., New York, N. Y., a corporation of New York p- Application October 18, 1944, Serial No.r 559,295

l 18 Claims.

The invention relates to a multiple pump, and more in particular, to a fuel injection pump for multiple cylinder engines, and contemplates the provision of certain improvements applicable with particular advantages to that type of pumps in which a plurality of units comprising a barrel and a plunger therein are-arranged parallel to and equidistant from a main axis, and wherein each plunger is reciprocatable once during each cycle of the pump operation, with a phase displacement in relation to the preceding plunger. Examples of such pumps are disclosed, e. g.l in my U. S. Patent No. 2,391,221 of December 18, 1945, wherein a common rotatable valve controls certain parts of the barrels, and in my U. S. Patent No. 2,383,462, November 6, 1945, wherein each plunger is provided with a helical head controlling a barrel port for metering the quantity of fuel to be discharged. However; it will be understood that the invention is not limited in its application to a particular type of pumps. Pumps of the kind sists essentially in the provision of hydraulic means to shift the control elements for output adjustment in response to pressure variations as occurring, e. g. in the manifold of an engine to which the engine may be applied.

According to another object of the invention Ia lubricant may be used as the pressure medium of the hydraulic means, the same lubricant serving to iubricate the movable parts of the pump.

The invention also contemplates theuse of oil from the lubricating system of an engine to which the pump may be applied as the pressure medium of said hydraulic means.

Further objects and details of the invention will be apparent from the description given hereinafter and the accompanying drawing showing embodiments thereof by way of example. In the drawing:

Fig. l is a longitudinal section of an embodiment of the invention, the section being taken along line I--I of Flg.2;

Fig. 2 is a cross-section along lines 2-2 of Fig. 1;

Fig. 3 is a development of the metering valve of the pump of Fig. 1;

Fig. 4 is a longitudinal section of another bodiment;

Fig. 5 is a longitudinal cross-section of the central part of the pump of Fig. 4 on a larger scale and taken along line 5-5 of Fig. 6;

Figs. 6 and 7 are cross-sections along lines 6 6 and 1--1 respectively of Fig. 5; and

Fig. 8 is a longitudinal cross-section of a modification of the pump of Fig. 4.

Referring now to the drawing, Figs. 1 to 4 illustrate by way of example a pump according to the invention and destined for use with a nine cylinder engine. The pump belongs to the type in which the output of each unit is controlled by a common valve. The pump comprises a block in general denoted by I0 which consists of a substantially `cylindrical portion II with a ange I2 at its lower end, and which has an axial bore Il throughout its length. Nine other bores Il are provided parallel to and equidistant from the main pump axis a--a. They reach from the top face I5 of the block not quite to the other end face I6 which is the lower face of the flange I2 so that each bore I4 constitutes a barrel with a bottom I'l. At a distance upward from the bottom I1, a radial port I8 opens from the barrel into the space of the bore I3, and a groove I9 in the interior of the barrel reaches from the port I8 downward to the bottom Il. The ange I2 is provided with radial bores 20. one for each barrel, and communicating with the bottom end of the latter. Each bore 20 is so formed as to constitute a chamber for a spring biased delivery valve 2l. The outer end of each bore 20 is -closed by a plug 22, and a hollow screw bolt 23 crosses the bore 2D and serves the dual purpose of securing the pump to a ange or other portion 24 of an engine, and of connecting the bore 20 to a conduit 25 leading to the nozzle (not shown)l of an engine cylinder.

A substantially cylindrical jacket or housing 26 bears on an outer shoulder 21 of the block I0 and also on a gasket ring 28 on top of flange I2. An annular fuel chamber 29 with an inlet 30 is formed between the housing 2B and block I0, and radial conduits 3| in the block I0 intermediate said barrels connect said chamber and the inner bore I3 of the block Ill. Interiorly of the bore I3, a valve 32 shaped as a hollow piston is arranged so as to be rotatable and axially shiftable by means to be described hereinafter. The valve, the development of which is shown in Fig. 3 has a peripheral recess 33 with a land 34 thereon t0 close-the ports I8, one

wider part ofthe land is in registry withl the ports.

However, it is ,to be noted that `the recess 33 is in permanent communication with' chamber 29 through at least some of the conduits 3I'..

Coaxlally with the block I8 and extending through valve 32, a hollow drive shaft 48 is arranged which is interiorly splined in its lower end portion at 4I in order to be coupled with a shaft 42 of the engine to which the pump is to be applied. The shaft 48 is provided with an end collar or flange 43 and journalled in a bearing 44 which in the illustrated embodiment is a ball bearing acting as a collar bearing as well as a thrust bearing. 'I'he outer race 45 of bearing 44 engages a ring 45 which in turn bears on an inner flange 41 of a casing 48 secured to the lower face I6 of the block I8. The casing is closed by a lower cover plate 49 with an opening 58, and it is so shaped as to form with the lower face of the block an annular recess I communicating with the opening 58 via a groove 52 in the inner wall of the casing. Another annular space 53 in communication with the axial bore I3 of block I8 is formed between the casing 48, ring 45 and shaft 48. Shaft 48 is journaled in a second bearing such as needle bearing 55 supported by a cupshaped member 54 which rests on an inner shoulaitefr the other during its rotation,"l :for a shorter or longer part of eachv der ofthe block I8. The shaft portion above the v needle bearing' is externally splinedat 51, and the topmost end 58 is screw-threaded. To the splined portion,.a shaft head 59 is secured by means of a slitted nut 88 screwed on the threading 58 and locked'in position by ascrewlil which forces the slitted nut portions apart or together so as to deform a portion of the nut threading. The shaft head 59 has an outer cylindrical bearing surface 82 which is inclined with respect to clearly shown -in Fig. 1.

the main axis a-a, and on which the inner race 83 of a ball bearing 64 is mounted so as to engage a head shoulder 85. A cup-shaped wobble or swash plate 88 is secured to the outer race 51 by means of a spring ring 68, and engages with a projection 69 stationary guide faces 10 arranged parallel tothe axis a-a. `When shaft 48 rotates, the swash plate will no t participate in the rotation owing to the engagement of the projection 59 with the guide faces 18 but will accomplish a cyclical up and down motion. The swash plate is provided with ball sockets 1 I, as many as there are barrels in the block I8, so as to receive therein the upper ball heads 12 ol connecting rods 13 of plungers 14 which are reciprocable in the barrels I 4. Each plunger consists of a tubular body 15 with a lower head 16 screwed into the body end. The lower ball end 11 of each connecting rod is sec ed to an accordingly shaped recess of the he d 16 of the associated plunger bya slotted retaining washer 18 bearing against an inner shoulder of the plunger tube 15. In order to rotate the metering valve while the plungers `are reciprocated, a pin or pins 19 are secured in the Valve bodyand engage the drive shaft 48 in slots 88 which permit axial adjustment of the valve relatively to the ports I8.

The pump so far described operates in the following manner: Ii. the drive shaft is turned by the engine shaft 42, the plungers will be reciprocated according to the cyclical oscillation of the swash plate, i. e. each plunger lagging in phase in respect to the preceding one and the phase lag being equal to 360 divided by the number of plungers. While the plungers are thus reciprocated the metering valve 32 rotates uniformly with the shaft 48. It is so adjusted in relation to the inclination of the shaft head 59 that each port I8 will be covered by the land 34 of the valve during a portion of the compression stroke of the coordinate plunger 13 and the length of such stroke portion will be determined by the width which the land has, according to its axial adjustment, between the edges 35 and 38 on the y level of the ports I8. During the suction stroke of a plunger, fuel may therefore enter the coordinate barrel from space 29 through conduits 3|, valve recess 33 and port I8. While the latter is closed during a portion of the compression stroke a corresponding quantity of fuel will be expelled by the plunger from its barrel through the delivery valve 2 I, and during the remainder of the compression stroke a corresponding quantity of fuel will be returned on the same Way as that on which fuel entered during the suction stroke.

In order to adjust the valve 32 in axial direction for the purpose of metering the quantity of fuel delivered by the pump, a tubular rod 84 is arranged interiorly of shaft 48 and the pin or pins 19 are secured to said rod so that the valve and the rod will rotate in conjunction and will be axially shiftable together in r-elation to the shaft 48. A recess 85 is formed between the shaft and the tubular rod and a compression spring 86 in that recess tends to shift the rod and valve downward. The upper end of the tube 84 extends through the top wall 81 of an upper housing part 8S which encompasses the swash plate with its accessorial parts and to which the aforementioned guide faces 18 are attach-ed. The part 88 is connected to the lower housing 26, the block flange I2 and the casing 48 by means of anumber of screw bolts 89 as On the upwardly projecting en'd of th-e Itubular rod 84 an anti-friction bearing 98 is mounted so as to abut against the flanged head of a hollow plug 9| screwed into the tubular rod 84. The bearing 98 is encasedv in aI ring 92 having two diametrically opposite trunnions 93 which are engaged by a forked lever 94. The latter is mounted on a shaft projecting laterally from the housing part 88 so as to be turned by suitable means not shown. Thus, if shaft 95 is turned in anti-clockwise direction, the tubular rod 84 together vwith valve 32 will be raised against the lres-traint of spring 88 while being free to rotate together with the drive' shaft 48.

Means are provided for an automatic adjustability lof the meteringv valve in response and according to pressure variations occurring in the manifold of the engine to which the pump is connected. Such automatic adjustabillty may be either instead of any other or may be in addition to one under the control of an operator. IThe illustrated embodiment shows a form which provides for such automatic adjustability in addition to that obtained by means of the lever 94 and accessorial parts. According to the invention, the automatic adjustment of the metering valve is accomplished by a hydraulic system under the control of a small auxiliary valve actuated -by a bellows which, thus, can be small in size and still fully effective `for Vthe contemplated purpose. Also, accordingy to the invention, the hydraulic iiuid used in the pump is the pressure lubricant which may be taken from the lubrication system of the engine to be charged by the pump, and which is anyway required to lubricate the movable parts of the pump. In the illustrated embodiment the ange I2 is provided with a radial conduit |88 communicating with the aforementioned annular '5 space 53 on top of the thrust bearing plate 48. The conduit has a port |0| in the bottom face of the flange for connection to a branch of the engine lubrication system, indicated at |02. The

outer end of the conduit is closed by a plug |03.`

nected by a substantially radial arm to the space |06 of the bore I3 on top of the metering valve 32; the aforementioned member 54 consti- 'tutes the upper confinement of the space |03. An outward extension |08 of the arm |05 opens into a ring groove |09 from which lubricating grooves of the plungers 14 are fed. Within the rangeof the valve 32 the shaft is provided with two relatively wide grooves I|| and |'|2, one above the other so that between the shaft and the`tubular rod 84 two annular chambers are formed. The lower groove or chamber ||2 communicates with space |06 through a groove ||3 of the valve 32 and an opening ||4 of the shaft. Similarly, the upper chamber communicates with Athe space 53 through a groove ||5 and an opening'lli, The tubular rod 84 extends in its lowermost position far downward in shaft 40 and is provided with two ports or sets of ports ||1 and ||8. The dimensions are such that these ports are permanently in communication with the chambers and ||2 respectively, regardless of the relative position of the tubular rod in shaft 40. Interiorly of a cylindrical space ||9 formed in the lower end of the tubular rod 84, an auxiliary slide valve is axially movable. Valve |20 has an upper and a'lower controlling edge, |2| and |22, respectively, so spaced from each other that the ports ||1 and ||8 are just closed in the illustrated position. It is shaped as a hollow cylinder and providedwith passages |23 connecting the spaces of the cylinder above and below the valve with each other. The valve |20 is integral with or attached to a control rod |24 which extends upward'through the entire length of the tubular rod 84 with ample.clear ance which constitutes a passage |25 from the space 9 through slots |26 in the upper portion of the tubular rod 84 to the swash plate chamber |21 formed by the upper housing part 88. The upper end of control rod |24 is guided in plug 9| of rod 04 and secured by suitable means such as a screw connection |38, to the lower wall |28 of a bellows |29. The top wall |30 of the bellows is attached to a tubular piece |3| passing through a housing cover |32 and held in position by nuts |33. The piece |3| opens into the bellows |29 and maybe connected to the engine manifold so as to subject the bellows to the interior pressure prevailing therein. The exterior of the bellows is under atmospheric pressure owing to the opening |34 in an extension |35 of the upper housing part 83 to which extension the cover |32 is secured by a screw threading |36. The weight of the rod |24 may be compensated by means such as leaf spring |31 attached to the housing 88- and engaging between the parts |38 by which the rod is connected to the bellows |29. This spring may be so formed as to prevent the rod |24 from rotating.

The automatic adjustment of the metering valve by means of the device just described takes place in the following manner: In Fig. 1 the metering valve 32 with the tubular rod 84 and also the auxiliary valve |20 with its rod |24 are ased discharge valve 2|0.

6 in their lowermost positions and the bellows is not subject to a difference of external and internal pressure.. The tubular rod 84 with valvev 32 rotates with the drive-shaft 40 owing to their connection -bygpin 19 while the auxiliary valve and rod |24 do not participate in such rotation. The spaces |03 and 53'above and below the metering valve 32 are filled with a lubricant under pressure from conduit |00. If, now, the interior pressure of the bellows |29 decreases, the

. latter will contact and lift rod |24 with auxiliary valve |20. In consequence, the lower controlling edge will open the port ||8 with the result that lubricant from space |00 can escape via' groove ||3, opening ||4, shaft chamber ||2, port H8, lower part of space H9. bores |23, upper part of space l 9. passage |25 and slots |26, to splash upon the swash plate and other movable parts in the housing chamber |21. From there the lubricant can flow through conduits |39 to the ring recess 5| :and further through groove 52 and vopening 50 back to the lubricating system of the engine to which the pump may be connected. Owing to the escape of lubricant from space |03 ythe pressure on the lower face of valve 32 will be greater than the pressure on the upper face so that the valve together with the tubular rod 84 will he raised. This will continue until the port ||8has passed the edge |22 and is closedby the auxiliary valve. When this has happened, the flow of the lubricant in space |06 stops and the pressures on top and below the metering valve 32 will again be equalized, so that the valve 32 will remainv in the'adjusted position according to the contraction of the bellows |29. If then, the inside pressure of the bellows increases and the latter expands, the auxiliary valve |20 will be lowered and port ||1 will be opened. In consequence the lubricant in the annular recess 53 underneath the valve 32 is free to ow off through the grooves, openings and passages H5, ||6, ||1, into the upper part of space ||9, and on as just described with respect to the lu bricant from space ||6, so that the valve 32 will be lowered until the opening ||1 has passed'the control edge' |2|v of the auxiliary valve. Thus, the adjustment of the valve 32 will follow exactly the pressure conditions prevailing in the engine manifold with which the bellows communicates.

Whereas in the embodiment hereinbefore described, the type of pump is such that the con-l trol element is to be shifted in an axial direc'- tion for the purpose of adjustingthe pump output, adjustment is accomplished in the embodiment which now will be described by a rotary movement derived, with the aid of hydraulic means, `from an axial movement of a pressure responsive organ. The ypump illustrated in Figs. 4 to 1 is of a kind as disclosed in my U. S. Patent No. 2,388,462 of November` 6, 1945. In a housing 20| a number of pump barrels 202, for

instance nine, are arranged parallel to and equidistant from the housing axis b-b. Interiorly of each 4barrel a reciprocatable plunger 203 is provided with a helical head 204 the end face of which controls an inlet and metering port 205 from an annular fuel chamber 206 intermediate the outer wall of the housing 20| and the barrels203. The housing and the `barrels therein are covered by a valve plate 201 which is provided with a discharge conduit 208 for each barrel and each conduit is in communication with a radial chamber 209 containing a spring-bi- The outer end of chamber 209 is so shaped that a pipe line 2| may be connected thereto. through which fuel discharged from the associated pump barrel .may be injected into the nozzle of an engine cylinder (not shown). Coaxially with the housing a hollow drive shaft 2| 2 is mounted in bearings 2|3 and 2|4. The shaft is interiorlyv splined at 2|5 in its lower end for driving connection with a hollow shaft 2|6 which is part of the engine to which the pump may be applied. Mounted on shaft 2|2 is a wobble or swash plate 2 |1 which is prevented from rotating by its engagement with a guide 2|8 so however, that the swash plate 2|1 is able to tilt cyolically about a shaft portion 2|9 which is inclined with respect to the main axis b-b. Each plunger 203 is connected to the swash plate 2|1 by a connecting rod 220 so that during each revolution of the shaft 2|2 each plunger 203 will be once reciprocated with a phase lag, however, in relation to the preceding plunger.

The output of each pump barrel depends on what portion of the helical head of the associated plunger registers with the port 205 during the plunger reciprocation. In order to adjust the output, that means in order to meter the quantity of fuel discharged through each valve 2|0, a pinion 22| is shrunk on or otherwise secured to each lower plunger end so that the plunger may be turned about its axis. The pinions 22| need not be provided with teeth about their entire circumference and it is sumcient if they form toothed segments according to the angle through which it is intended to render the plunger turnable for adjustment purposes. All the pinions 22| mesh with a centrally arranged gear wheel 222 which is mounted by bearing 223 on shaft 2|2. The wheel 222 which is hollow to receive therein the bearing 223 has an upward tubular extension 224. Into the latter and coaxially therewith another tubular member 225 extends which bears with a lower shoulder 226 upon a casing 221 supported by the outer race of the aforementioned bearing 223. Interiorly of casing 221 a spiral spring 228 is arranged the one end 228' of which is secured to the member 225 whereas the other end 228" is fastened to the gear wheel 222. Two vanes 229 engage with their outer ends grooves 230 of the tubular extension 224 and are slidable with their inner ends 23| on the outer cylindrical surface 232 of the member 225. Owing to this arrangement the vanes 229 will be. taken along when the wheel 222 with its extension 224 turns in relation to the member 225. The latter is also provided with oppositely positioned vanes 233 engaging in grooves 234 and being provided with segment-shaped extensions 235 which engage the inner cylindrical surface 236 of the wheel extension 224. In their normal position, the diameter on which the vanes 233 are arranged crosses the diameter on which the vanes 229 are located at approximately right angles so that four chambers 231, 238, 239 and 240 are formed interiorly of the wheel extension 224. The hollow space 24| of the member 225 is in communication with the chambers 231 to 240 by ports 242, 243, 244 and 245 respectively. Member 225 is closed at its top end at 246. A tubular guide member 241 bears with a lower flange 248 on the top rim 249 of the wheel extension 224. The aforementioned -blades 233 are secured to flange 248 by means of pins 250 as clearly shown in Fig. 5, so that owing to the engagement of the vanes 233 with the member l 225 the parts 225 and 241 are prevented from movement relatively to each other. Interiorly of 8 the guide member 241 (Fig. 4), a'pisto'n 25| is axially movable and a compression spring 252 is inserted between piston 25| and a plate 253 which bears on top of the member 225 and is rotatable within the flange 246 of the guide 241. Plate 253 has an upward extension 254 -of tubular shape so as to fit into the lower portion of the tubular guide 241. The piston 25| is provided with lateral projections 255 which engageinto slots 256 in the wall of guide 241 and also slots 251 in the tubular extension 254 of the blade 253. Either one of the pairs of slots may be helical and the other one straight lined in a direction parallel to the axis b-b or both pairs may be helical but turning in opposite directions. The upper end of the guide member 241 is formed as a pinion 25B which meshes with a rack 259 projecting laterally from the housing top piece 260 secured to the lower housing 20| by suitable means such as screws 26|. The inner portion vof the piece 260 forms a bearing surface 262 for the upper portion of the guide member 241. Housing portion 260 contains a conduit 263 which opens towards the outside at 264 and communi-'- cates on its inside with an annular cham-ber 265 surrounding the lower portion of the guide 241. Chamber 265 in turn can communicate with the aforementioned vane chambers 231 to 240 through the slots 256 and two recesses 266 and 261 in plate 253 which recesses are slightly larger in size than the width of the vanes 233 and are normally so positioned with respect to these vanes that in the relative position of Fig. '7 all the cham-bers 233 to 240 are connected with the chamber 265. A dome-shaped cover 268 is secured to the top housing 260 and encases two bellows 269 and 210. The bellows 269 is adjustably secured to the cover by a screw connection 21| with a conduit 212 for communication of the interior of the bellows with the atmosphere. The lower bellows 210 is suspended from the upper bellows 269 by a connection 213 which permits rotation-cf the one relatively to the other. Bel lows 210 is attached by means of a hollow screw connection 214 to the interior of the guide member 241 on top of piston 25| so that the space 219 above the piston communicates with the interior of the bellows 210. The latter is preferably of a type which is temperature sensitive, so that with rising temperature it will bulge outwardly thereby increasing its capacity. It is filled with a liquid which when the bellows is subjected to outside pressure will cause the piston 25| to descend against the restraint of spring 252. Both the bellows 269 and 210 may be externally exposed to pressure or depression'prevailing =ln the manifold of the engine to which the pump may be applied and for this purpose the top housing portion 260 is provided with an opening 215 into which a connecting pipe (not shown) may be screwed so that the entire inner space 216 of the housing top portion and the inner space 211 of the dome-shaped cover may be in communication with such manifold.

In order to operate the pump the interior of the shaft 2|2 is to be connect-ed to a source of culate through 'the chamber 206'. The lubricant outlet 264 may be in communicationwith the oil well of the engine and the opening 215 may be in communication with the engine manifold as hereinbefore stated. 1 Owing vto its connection with the atmosphere the bellows 269 will be sub- .lected to an interior pressure according to the surrounding air and, therefore, be sensitive to changes of the altitude. The bellows 210 together with the space on top of piston 25|, 'on' the other hand, is sensitive to changes of the temperature and manifold pressure as stated hereinbefore. In consequence, a decrease of altitude and an increase of temperature will act in the same way so as to increase the pressure on piston 25|. Also, an increase of the depression in the engine manifold will have a similar effect. ,When the engine with the pump coupled thereto is operating, correct adjustment of the required pump output may be accomplished by shifting rack 259 which will cause guide 241 to turn. Gear wheel 223 will be taken along owing to the connection between ange 248, pins 250,- vanes 23,3. centerpiece 225 and spring 228. Also, piston 25| and plate 253 will turn with the guide 241 so that the piston remains on its original level, and the recesses 266 and 261 keep the passage open from all four vane chambers 231, 238, 239 and 240 to the annular space 265. If now, the conditions under which the engine operates vary, increasing depression in the manifold will cause an expansion of the bellows 269. In consequence the latter will exert pressure on the top of the bellows 210 with the result that liquid from bellows 210 will be forced in the chamber 219 on top of the piston 25|. Also. if the temperature decreases causing a contraction of the bellows 210, a portion of the liquid therein will be pressed into the mentioned chamber 219. The pressure exerted on the piston will force the latter downward against the restraint of spring 252 and the piston projections 255 sliding in the slots 256 and 251 will turn the plate 253 while guide 241 is maintained stationary owing to its engagement with rack 259. Originally, oil could flow through shafts 2|6 and 2|9 into the interior .of the member 225 and from there through the openings 242 to 245 into the vane chambers 231 to 240 respectively. From there oil could escape'A through the gaps between the side walls of the plate recesses 266 and 261 and the varies 233 and also pass from there into the ring space 265 and on through conduit 263 to the outlet 264.` Now, when the plate is turned from the position shown in Fig. 7 in the one or other direction, the recesses 266 and 261 will slide over the top surfaces of' the vanes 233 thereby closing two opposite vane chambers, for instance the chambers 238 and 240, while further opening the communication between the chambers 231 and 239 with the outlet. In consequence, .oil pressure will rise in chambers l231 and 239 and decrease in chambers `2-38 and 240. The pressure difference will shift the vanes 229 accordingly and, together with them, rotate the gear wheel 222 which turns the plungers 203; Turning, however, of the wheel 222 will tension spring 228 owing to the connection of the latter with the member 225 and wheel extension 224. An'equilibrium will be reached when the torque owing. to the pressure difference.

acting upon the vanes 229 becomes equal to the torque due to the tension of the spring 228. Further, the pressure difference acting on the vanes 229 will be the larger the wider the recesses 266 and 261 open an outlet for the flow of the oil through the annular chamber 265. Such opening l0 however will be proportional to the distance piston 25| has been lowered and, owing to the engagement of the projections 255 with the slots 256 and 251, has turned the plate 253. When the pressure diierence on the vanes 229 decreases the spring 228 will turn wheel 222 in the opposite direction and thereby adjust the plungers 203 accordingly. While, thus, a continuous oil current news freni the shaft als to the ouuet 264 quantities of the lubricant may escape through a lateral bore 280 in shaft 2 I 2 into the lower housing space 28| so as to lubricate the movable parts of the pump including the faces of the plungers 203 provided with oil grooves and bores such as indicated at 282. From the space 28| the lu-l bricant may return to the engine by passing through the bearing 2|3.

According to the arrangement' and type of bellows of the embodiment jus-t described, automatic adjustment of the pump output occurs in response to changes in external pressure and temperature. It will be understood, however, that the pump ada justment may lbe rendered responsive to changes of other external conditions, and that for such purpose it will be necessary only to select suitable elements reactive upon such other con-ditions and to adapt these elements so as to transmit their reactions on piston 25| in substitution for the bel- v lows 269 and 213.' Also, it will be understood that the invention is not limited to the particular hy' draulic device illus'trated in Figs. 4 to '1 and hereinbefore described. Thus the embodiment shown in Fig. 8 is provided with a modified drive for the adjustment of the plungers of the units. In other respects, the pump is similar to that shown in Fig'. 4. The embodiment of Fig. 8 comprises a lower housing 30| with a number of barrels 302 in which plungers 303 are reciprocatable by means ofa swash plate drive 304. The cyclical tilting of the swash plate is derived from a Vshaft 305 adapted for connection to an engine shaft 306. Both shafts are hollow so that pressure oil may be forced through the shafts 306 and 305 and through a lateral opening 360 of the latter into the housing space 301. A disc-like part 308 com--v prising a. discharge valve 309 lfor each barrel is se-y cured between the lower housing 30| and' a top housing portion ,3|0, and a dome-shaped cover 3| i is fastened to the latter and encases t'he altitude bellows 3I2 and the 'temperatureand pressuresensitive bellows 3|3, al1 in coaxial arrangement. Housing 30| comprises an inner ange 3|4 which serves to hold a bearing 3 I5 and an auxiliary shaft 3|6. Another bearing 3|1 for the auxiliary shaft 3 ||6 may be provided as shown in engagement with the bearing 3|8 of the drive shaft 305. A gear wheel 3|9 is keyed to the auxiliary shaft 3|6 at 320 and meshes with the pinions 32| of the plungers 303 similar 'to -wheel 222 in mesh with pinions 22| in Fig. 4. A control drum 322 is also secured to the auxiliary shaft 3|6 'and extends upward of ange 3|4 into the axial housing bore 323 which in its upper portion and including the central opening 324 of the disc 308 is lined with a cylindrical bushing 325.' In engagement with the latter, a cup-shaped piston 326 is arranged for axial movement. To the lower head 321 of the piston one or several rollers 328 are pivoted on pins 329 which rollers engage in helical slots 330 provided in the wall of the drum 322. Piston 326 is biased by a compression spring 33| bearing against the top housing portion 3|0 into which a tube 332 is rotatably inserted. To the `lower end of tube 332 two tubes 333 and 334 are secured e. g.

by soldering, so as 'to extend downwardly, the one.

the bottom at 331. and an Aopening 336 is provided in its wall. There is also an opening 340 provided in the tubular part 332 to connect the'interior of the latter -witha ring space .34| in the top housing portion 3|0, and a conduit 342 leads from the spaceg34| to the outside at 343. The upper end of the part 332 is provided with peripheral teeth 344 with which a rack 346 meshes in an arrangement similar to the rack 269 ofFig. 4. A rod 348 is connected to the lower side of the bellows 3|3 and extends downward into the tubes 332 and 334 lfrom which it is spaced by a spacer 341' which closes the upper end of the tube 332. At its lower end and at a distance therefrom, the rod is provided with two enlargements 343 and 34E/which control the opening 339 of the tube 334. Rod 346 has an axial boreV 360 which communicates through an opening 36| above enlargement 343 with the space 362 between the rod' and thetubui v lar part 332. Communication is also provided of the'housing space 361 with the 'aforementioned space 333 between the tubes 333 and 334 through ports 363, 364 and 366 provided in the disc of wheel 3 I 3, in the flange 3|4 and the bottom of the drum '322 respectively. i

The pump output can be manually adjusted by shifting the rack 345 in the one or other direction.` Thereby, the tubular piece 332 will'be turned and with it the extensions 333 and 334. Owing to the slot and p in connection 336 and 336 between the tube 333 and piston 326, and dueA to ',the rollers 328 engaging in the slots oi the drum 322, the latter is taken along so as to turn the auxiliary shaft 3|6, the wheel 3|3 and the pinions 32|. Thus, the plungers 363 will be adjusted according to the shifting of the rack 346.

If on the other hand, the rack is held stationary,

automatic adjustment 'will be accomplished in response to the expansion or contraction of the bellows 3I2 and 3l3. In the position of Fig. 8, the enlargement or valving portion 343 'of rod 346 obstructsV the slot 336. In consequence, as soon as the engine to which the pump is applied is started, oil pressure will build up inhousing 361 and all spaces connected thereto, including the space underneath the piston bottom 321 which will rise according to the oil pressure and the restraint of spring 33|. Ingrising,

the rollers 328 move in the helical grooves of the drum.322, and as the piston 326 is prevented from turning owing to pin 336 'in slot 336 of the' tube 334 which is held stationary, the drum 322 will be turned together with auxiliary shaft 3|6 and wheel 3| 3 so as to adjust the plungers to the conditions of the engine just started. If now the operating conditions of the engine change so that one or both of the bellows 3|2 and 3|3 expand, rod 346 will be shifted downward within-tube 334. while the pressure underneath the rod and above the enlargement 343 is equal- 12 action oi spring 33| will be lowered and thereby turn the drum accordingly. The farther rod 346 is lowered the wider will be the opening oifered to the oil ilow and, consequently, the lower will be the position of theA piston 326. Thus the piston position and as a result the position oi the plungers 363 will depend on the expansion or contraction of the bellows 3 i 2 and 3 I 3.

i It will be apparent to those skilled in the art that many alterations and modifications of the illustrated forms can be made without departure from the spirit and essence of the invention which shall be limited only by the scope oi the appended claims.

I claim:

1. In a pump including a supply'chamber, at least one pump unit having a barrel with an inlet aperture and a plunger reciprocatable in the coordinate barrel, and a conduit between said supply chamber and said aperture. the combination of ilrst means having a curved race in controlling relationship to said aperture and being movable in an -axial direction and a peripheral direction, a second means whereby said plunger and said nrst' means are held in iixed relationship and said plunger reciprocated.v and said means moved in one of said directions, third means including a hydraulic servo motor to cause movement of said first means in the other one oi.' said directions thereby to change the portions l of said face passing said aperture to vary the time piston.

ized through the bore 360 and the lateral hole during which said barrel is periodically connected to said supply chamber, a control element for said servo-motor.y and a pressure responsive organ in controlling connection with said element so as to cause movement oi.' said nrst means 4in said other direction according'to pressure variations to which said organ is subjected.

2. A. device as claimedin claim 1 wherein `said pump includes a plurality` "of units'arranged'in an annular zone, equidistant from each other and parallel to a common axis, said first means, said hydraulic servo motor and said control element having an axis coinciding with said common axis and being located substantially in a cylindrical space central with respect to said annular zone. Y f

. 3. In a pump including a plurality of units comprising each a barrel and a plunger reciprocatable therein, a common inlet and metering valve in central arrangement with respect to said plurality of units, said valve being rotatable so as to serve said units one after the other and being axially :shiftable to cause variation of the output of said units according to the level on which it rotates, said valve constituting s. piston of a hydraulic device.. means responsive to external pressure conditions, and a member connected to and shiftable 'by said pressure-responsive means andin- `cluding a valving means oi said hydraulic device to control the hydraulic pressure acting on said v4. In a pump as claimed in claim 3. further comprising a second valving means of saiclhydraulic device. said second valving means being connected for common movement with said piston andv being in cooperative relationship to said iirst valving means so that a pressure difference caused on Athe opposite sides' of the'piston by a shift oi said first valving means will be .equalized when said i'irst and said second valving means are in their original relative positions.

5. In a pump including arplurality of units comprising .each a barrel and a plunger recip rocatable therein, a cylinder in central arrange- 13 ment with respect to said units, a common inlet and metering valve in said cylinder, said common valve being rotatable vin said cylinder so as to serve `said units one after the other upon its rotation, and being axially shiftable to cause variation of the output of said units according to the level on which it rotates, said valve constituting a piston of a hydraulic system, first conduits to adturning,

mit a hydraulic fluid to the cylinder spaces respectively on either side of said piston, two second conduits in 'said piston todischarge fluid from said yspaces respectively, and an axially movable valving means in controlling relationshipv to said second conduits so as to open one of said second conduits when moved in the one direction and to open the other second conduit when moved in the other direction, said second conduits being so arranged that a. second conduit opened bye. shift of said valving means will be closed when said piston is moved in the same direction.

6. A device as claimed in claim further comprising a manually operative member in connection with said piston to shift it in axial direction, and means responsive to changes of external pressure conditions and in connection with said valving means to control th-e position of the latter.

7. A device as claimed in claim 5, said piston having an axial bore into which said second conduits open, said valving means being arranged interiorly of said bore and including a rod extending to one side beyond said cylinder, and a tube connected to said piston and surrounding said rod in a spaced relationship thereto so as to constitute a passage for the valved fluid.

8. In a pump including a plurality of units comprising each a barrel and a plunger reciprocatable therein, a common inlet and metering valve in central arrangement with respect to said pluraiity of units, and being provided with an axial bore, said valve being rotatable so as to serve said units one after the other and being axially movable to cause variation of the output oi the units according to the level on which it rotates, a hollow rotatable drive shaft passed through the bore of said valve and provided with an axially extending slot in its wall, a, tubular member interiorly of said shaft, a pin in engagement with said slot and connecting said common valve to said tubular member, and a second valve interiorly of "said tubular member, said common valve constituting avpiston of a hydraulic device including conduits in said piston, said shaft and said tubular member to connect the spaces on either side of said piston to the interior of said tubular member, and said second valve being in controlling relationship to said conduits.

9. In a pump inculding a plurality of units comprising each a barrel and a reciprocatable plunger turnable therein for the purpose of adjusting the output of its unit, the combination of a member in engagement with all the plungers to turn the latter. a hydraulic device to turn said member, an organ changeable as to its dimensions in response to changes of external conditions, and a control element of said hydraulic device and operative by said organ so as to control operation of said demeans for said and a connection between said member and said piston, said connection including helical guide faces to transform axial movement of the piston into turning movement of said member.

12. In a pump including a plurality of umts comprising each a barrel and a reciprocatable plunger turnable for the purpose of adjusting the output of its unit, a gear wheel in engagement with all said plungers, said wheel including a hollow cylindrical extension and a rst pair of diametrlcally opposite vanes projecting inwardly from the walls of said cylinder, a normally stationary shaft coaxially with and interiorly of said cylinder and including a second pair of varies pro- Jecting towards the wall of said cylinder and intermediate said first vanes respectively so as to form a chamber between each two adjacent vanes, means to conduct a hydraulic fluid to said chambers, a valvlng means for the discharge of equal quantities of Huid from opposite chambers, and means to adjust said valving means so as to cause pressure diilerences in each two adjacent chamlbers and thereby to turn said iirst pair of varies with said cylinder and wheel.

13. A device as claimed in claim 12 further ecmprising a spring in connection with said cylinder and said shaft, so as to betensioned when the cylindex' is turned relatively to said shaft in one direction.

14. A device as claimed in claim 12 wherein said valving means comprises a rotatable cover of said cylinder and provided with-two diametrically opposite openings, each oi' said openings beng oi' suillcient size to communicate with two adjacent chambers when said openings are in registry with the second pair of vanes'.

- valving means comprises vice according to changes of the dimensions of with said wheel to turn it, an 56' 15. A device as claimed in claim 12 wherein said a cover plate of said cylinders, said plate being turnable about the axis of said shaft and provided with discharge openings, and said means to adjust said valving means comprises an axially movable member, an axial exten sion of said plate and a connection between said axially movable member and said plate extension, said connection including helical guide faces to transform axial movement into rotation.-

16. In ,a pump including a plurality of units comprising each a barrel and a reciprocatable plunger turnable therein for the purpose of adjusting the output of its unit, the combination of a wheel in engagement with,al1 the plungers to turn the latter, a hydraulic device in connection organ changeable as to i-ts dimensions in response to changes of eX'- ternal conditions, a control element of said hydraulic device and operative by said organ so as to control operation of said device according to changes of the dimensions of said organ, and manually operative means in connection with said hydraulic device and said wheel to turn both said device and said wheel together independently of said organ.

17. In a pump including a plurality of units comprising each a barrel and a reciprocatable plunger t-urnable therein for the purpose of adjusting the output of its unit, the combination of a wheel in engagement with all the plungers to turn the latten-a. drum connected to said wheel for common rotation, a cylinder coaxial with said wheel, a piston reciprocatable in said cylinder, a. connection including helical faces between said drum and said piston, a compression spring between the cylinder bottom and the one side of said piston, means to admit a hydraulic fluid to piston to prevent the latter from 15 load -the other side of said piston. to discharge fluid', an organ responsive to changes of externaicondition, and a valve for said discharge and connected to said organ soas to adjust the discharge cross-section according tothe reaction of said organ on said vaive.

18. A device as claimed in claim 17 further comprising a iirst tube extending axially into said cylinder including means to prevent said piston from rotating relatively thereto, a second tube interiorly of and spaced from the rstone so as to constitute a discharge conduit. a spacer member secured to the end portions of said tubes remote from said piston so as to close said conduit, a discharge opening in the sidewall of said' second tube, said valve controlling said opening, and manually operative means to turn said spacer and with it said tubes, piston, drum, and wheel independently of said valve.

LOUIS BEEH.

REFERENCES verrno The following references are of record -in the file of this patent:

' 16 UNITED -sTATEs PATENTS Number f Name -Date 2,093,477 Parsons Sept.`21, 1937 2,131,857 Laux'et Oct. 4, 1938 2,160,735 Hoffer May 30, 1939 2,357,563 Truxell Sept. 5, 1944 2,370,506 Tabb Feb. 27, 1945 2,380,574 Beeh et al -w..- July `31, 1945 2,388,462 Beeh Nov. 6, 1945 2,391,221 Beeh Dec. 18, 1945 FOREIGN PATENTS Number Country Date 198,793 Switzerland Sept. 16, 1938 499,242 Great Britain Jan. 20, 1939 OTHER REFERENCES serial No. 288,980, mec-h1 (14.1?. c.), published May 11. 1943.

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