US2087816A - Hydraulic piston machine - Google Patents

Description

July 20, 1937. L. sAussARD r AL 2,087,816

' HYDRAULIC PIsToN MACHINE Filed may 1o, 1954 2 'sheets-sheet 1 July 20, 1937. L. sAussARD ET Al.

` HYDRAULIC PISTON MACHINE Filed May l0, 1954 2 Sheets-Sheet 2 a m my Patented July 2o, 1931 UNITED As'rrrrrfzs PATENT oFF-ICE HYDRAULIC PISI'ON MACHINE Louis Saussard and AndrSaussard, Paris, France- Application May.10, 1934, Serial No. 725,002 y In France May 27, 1933 i 5 claims. '.(cl. 10s- 163) This invention relates to piston pumps or motors with means for varying the stroke of the piston and particularly to machines of this kind in which the cylinder chambers are formed by 'a 5 frame sliding in one direction in a hollow bodyrotatably mounted in a spherical bearing located.

at some distance from said head; a conical movement is. imparted to said shaft around the center of said bearing and the angle of this conical movement can be varied at will.

Another` feature of the invention consists in that in said shaft and in its spherical head are provided .ducts and ports for the r'low of the fluid which portscooperate with ports provided in a -spherical cavity of the inner sliding frame so' as to ensure delivery, whatever may be the angle o the conical motionpof said shaft. s

A further feature of the inventionconsists in that the sliding frames each carry a pair of opposite. pistons, the pistons carried by the inner frame are at right angles to the two carried by the outer frame and slide within cylinders which are also carried by the outer sliding frame, and the pistons carried by the latter slide within y stationary cylinders connected to the outer body.

Said frames do not act as pistons, but merely 'carry the same, they can therefore have large dimensions which are larger than the diameter -of the pistons, thus a spherical head of large diameter to be used in the inner framekwhich is an advantageous condition for reducing the wear of the friction surfaces and-for maintaining the duid-tightness required for the delivery Iof the lfluid through the ports provided in said friction surfaces.

The annexed drawings illustrate, by way of example, an embodiment of a pump according to the invention.

rig. 1 is a vertical longitudinal section of the.

` whole of `said pump, the pump shaft -being at dead center (no delivery).

n Figs.' 2 and 3 are 'respectively a. vertical section Said arrangement allows the outlet or inlet.

accordingto line II--I of Fig. 1, and apartial horizontal section of the drive forgthe pump shaft.,

Fig. 4 is an elevation, partly in section, of the pump shaft.

Fig, 5 is a cross section made according to line V-V of Fig. 1.

:This pump comprises two rectangular frames Ill and I I slidingthe one in the other in the direction ZZ (Fig. 5) and an outer 'body 'l inV which said outer frame il slides in the. direction YY perpendicular to ZZ.

The frame l0 comprises. two -symmetrical halves Illa, Illb and carriestwo cylindrical projections Illc, wd about which are secured sleeves ille, lllf forming pistons, which' slide. inY two cylinders lle, llf connected to the frame I'I.' The'.

latter also carries two projections llc, Ild surrounded by sleeves llg, Hh forming pistons and sliding in cylinders le, 1f connected to the body 1.

Said body is also composed of two symmetri-Y cal parts 1a, 1b and the latter are mounted within` a casing 6.

The inner frame I0 is provided with a spherical'.

cavity log in which is loosely fitted the spherical head 5a of a driving shaft 5. l Between its ends,I

said shaftcarriesa 'ring lGa (Fig. 1) maintained by rollers I6 at the middle of a spherical bearing `Iib secured to casing 6, so that said shaft can rotate about its own axis andrevolve around' an axis Im'passing through the center Il of the',

bearing I6b.

When the shaft 5 is inclined according .to a

certain angle (towards the positions a or a indicated in dot and dash lines) relatively tothe axis XX, the same describes a conical movement about XX and its head 5a imparts to frame I0 a circular movement of translation so that frame I0 moves to and fr o in frame Il and the latter moves to and fro in the body ,I.

During oscillation 'of shaft 5,'the'head 5a' tends to describe an arc of circle about the`center of the spherical bearing Mib, so that this head moves transversely' to the plane of the-frames and moves these latter in this direction. But the strokeof the pistons is so small that said theoretical transverse displacement is nearly null (a v few hundredths of a millimeter in the drawing) and is absorbed by the unavoidable plays between the bearing Ib and the bearing Ilia, between the head 5a and the' frame I0, between this frame body 'l in the direction of the axis of, the pump;

and frame ll, and between the frame Il and the the operationof the pistons is therefore not in.-

luenced by the oscillation of shaft 5.'

The shaft 5 is actuated by a driving shaft I mounted in a casing 4, 4a connected to casing 6, and its axis is in alignment with the axis XX. The inner end of the shaft I forms a sleeve 22 within which extends the end 26a of shaft 5 and which is suiiiciently large for allowing said shaft `to oscillate according to any desired angle about the center 0.

The end 26u. is fork-shaped and carries, by means of an axle 24, a disc 23 located in said fork and guided at two diametrally opposed points in mortices 22a, 22h of the sleeve 22.

The periphery of disc 23 is partly toothed and these teeth 23a mesh with a rack 25 connected to a sleeve I8 slidably mounted on sleeve 22. The axle 24 is provided out of the center of the disc 23, so that the rotation of the latter has the eiect of shifting shaft 5 relatively to the axis XX and of modifying the angle of the cone described by said shaft, and, consequently of modifying the stroke of frames Il), II.

Ihe longitudinal displacement of sleeve-I9 is obtained by means of a hand lever 21 pivoted at 28 on the casing 4 and of a sleeve I8 sliding within the latter, the inner end 21a of lever 21 engages a recess I8a of sleeve I8 and the latter is connected to the sleeve I9 through a ball bearing 20 and a ball thrust bearing 2|.

In the embodiment shown by way of example the lever 21 is connected to an accelerating pedal 46 through a link made of two telescopic parts 41a, 411;, a pressure spring 48 checking the extension of said telescopic parts.

The casings 4 and'6 contain a liquid, such as oil, and during normal operation of the pump, said liquid is sucked by the pistons of frames III and II through ports 5f, a duct 5b and a port 5d provided in shaft 5, said port opening on one side of the spherical head 5a, (Fig. 4) said liquid is forced by the same pistons'through a port 5e and a duct 5c provided in said` head 5a., said port 5e being diametrally opposed to said port 5d.

Said ports cooperate 'with ports Ilih, I Ili and Ilz', II7` provided in the frames (Fig. 5) so as to connect port 5d with thecylinders IIe, IIf, 1e, 1f at the time the capacity of said cylinders increases, and to connect said cylinders with port 5e at the time their capacity decreases. The liquid is thus forced through the duct 5c of shaft 5 when said shaft is inclined towards the position a (Fig. 1). i

The direction of iow of the pumped liquid is inverted when the disc 23 is turned so as to incline shaft 5 towards the position a; the liquid would then be sucked at 5c and delivered at 5f.

In the example given herein, the casing 6 is closed on the -side o f head 5a by a cheek member I5 at the middle of which can slide a sleeve 56; beyond said cheek'member is secured the casing 6a of a hydraulic motor (not shown) the exhaust port of which is connected to the interior of casing 4 by means permitting the liquid to circulate in a closed circuit."

ton-frames reactions which tend to bring back the center of head 5a towards the axis XX and, consequently, to bring back the disc 23 and its driving mechanism to dead center. In order to balance, at leastpartly, the recoil action upon the driving mechanism independently of the thrust exerted by the hand of the driver' upon lever 21 or by his foot upon pedal 46, the following device has been provided:

The sleeve 56 is in communication, through holes 58a, with ducts 6I (only one of said holes being shown in Fig. 1) which lead into cylindrical chambers 4I provided in the end of the casing 4, 4a, so that the delivery pressure will act upon pistons 43 sliding in said chambers and 1on1 gitudinally pushing the ball thrust bearing 2 I.

The said thrust, transmitted through sleeve `I!! and rack 25 to disc 23, tends to cause the latter so that the displacement of the accelerating pedal under the pressure of the foot will be transmitted to the lever.21 and to the sleeve I8 in a suitable ratio so that the Variation of stroke or motionv resulting from the said displacement will be substantially proportional to said power Without causing the speed of the engine to vary.

Moreover, should the resistance to delivery vary for a given inclination of the'shaft 5, the reaction upon the regulating device, partly balanced by virtue of the action of the pistons 43,A

will be absorbedby the spring 48, so that, the pedal 46 `being left motionless, the lever 21 will be displaced by the action of the said spring and will automatically modify the stroke of the pistons, consequently the delivery, without changing in a noticeablemanner the speed ofl rotation.

The machine illustrated further comprises a device allowing one to divert the delivery of the pump through a by-pass; for that purpose, between the recess 58 around the sleeve 56 and a recess 65 in the cheek member I5, a valve chamber 66 is provided in the said cheek member I5, said chamber communicating with these two recesses through ducts 66a, 66h. Under normal conditions, the 'communication is cut oif by a. valve 61. In the example illustrated, the tail of said valve is made of two telescopic elements 61a, 61h embracing a joint 68. The pressure required for ensuring the fluid-tightness of said joint is obtained by screwing a threaded tie-rod 69 connecting together the two parts 61af-61b.

The tail 61a, 61h, is screwed at 61a into the -of the spring 48 can be advantageously adjusted cheek member I5 so that by causing the same to rotate, this causes valve 61 to open and, consequently, the pump is short-circuited through 56, 58, 66a, 66h, 65, through the interior of the casing 6 which communicates with 65 outside the frame II, and through the interior of the casing 4 which is in communication with 6 through bearing I 6b; or again the normal operation of the pump is reestablished by closing the valve 61.

We claim:

1. A' piston machine comprising two frames sliding the one in the other, an outer hollow body in which the outer frame slides transversely to the direction in which the two frames are respecpivoting shaft journalled in said spherical bearing andA provided at one end with a spherical head journalled in the inner frame, a driving 'tively sliding, a stationary spherical bearing, a i

shaft arranged for rotating about an axispassing through the center of said spherical bearing, and means for varying the inclination of saidpivoting shaft relatively to the driving shaft, means for connecting together said shafts for causing them to revolve together about the axis of the driving shaft, said pivoting shaft and its spherical head having inlet and outlet channels provided therein and the inner frame having ports provided therein and arranged forcooperating with the channels of said pivoting shaft for the passage of the fluid entering into and issuing from the variable chambers formed between said sliding frames and between said outer frame and said outer hollow body. y

2. A piston. machine comprising two frames sliding the one in the other, and an outer hollow body in which the outer frame slides transversely a connected to the other end of said pivoting Shaft and at righi'l angles .relativelyto the axis of said shaft, said driving shaft being provided with a recess in which the said disc is guided so as to be able to transmit to the pivoting shaft the rotary motion of the driving shaft and means for caus-` in g said disc to revolve about its eccentric pivot for thepurpose of modifying the inclination of said pivoting shaft relatively to the driving shaft, said pivoting shaft and its spherical head having inlet and outlet channels provided therein and the.inner frame having ports provided therein and arranged for cooperating with the channels of said pivoting shaft for the passage of the fluid entering into and issuing from the variable Y chambers formed between said sliding frames and between said outer frame and saidhollow body.

3. A piston machine comprising a stationary outer hollow bodyjin which are provided two cylinders concentric to a common axis and two cylindrical guide-faces between said cylinders and concentric to them, an outer frame provided on two opposite sides 'with projections in which is provided a cylindrical bore and theends of which form cylindrical guide-faces arranged to t in and to slide between the guide-faces of said hollow body, said frame bearing on the two other sides, pistons extending outwardly and arranged to slide in the cylindrical cavities of said hollow body the inner surface of these sides being shaped to form cylindrical guide-surfaces, concentric with said projections, an inner frame bearing on two opposite sides, pistons arranged for sliding in said bores of said projections of the outer frame, the other sides of said inner frame 'being shaped and arranged to fit in and to slide between said guide-surfaces of the outer frame; said inner frame having provided therein a spherical cavity,

a pivoting shaft having a spherical head fitted in said spherical cavity, a stationary spherical bearing in which'is located said pivoting shaft, driving means arranged for rotating said pivoting shaft and control means arranged for varying the inclination of said pivoting shaft, said pivoting shaft and its head having inlet and outlet channels providedl therein `and the inner frame having ports provided therein and arranged for cooperating with the channels offsaid pivoting shaft for the passage of the fluid entering into and issuing from the variable chambers formed between said sliding frames and between said outer frame Vand said outer hollow body.

4. A piston machine comprising tvvo frames sliding the one in the other, an outer hollow body in which the outer frame slides transversely to the direction-in which the two frames are respectively sliding, a stationary spherical bearing, a pivoting shaft journalled in said spherical bearing and provided at one end with a spherical head fitted in the inner frame, means for causing said shaft to rotate about its own axis and to revolve about a stationary axis passing through the center of said spherical bearing and control means for varying the inclination of said pivoting shaft relatively to said stationary axis, yielding elements in said means for partially balancing the thrust due to the reactions of the ilui'd n between said piston frames, said pivoting shaft having inlet and outlet channels provided therein and the inner frame having ports provided therein and arranged for cooperating with the channels of said pivoting shaft for the passage of .the fluid entering into and issuing from the variframes and' between said outer frame and said outer hollow body.

5. A piston machine comprising two frames sliding the one in the other, an outer hollow body in which the outer frame slides transversely to the direction in which the two frames are respectively sliding, a stationary spherical bearing, a pivoting .shaft journalled in said spherical bearing. and provided at one end with a spherical head fittedv in the inner frame, control means for varying the inclination of said pivoting shaft and balancing means for partially balancing the thrustdue to the reactions of the Viiuid between said piston frames', said balancing means comprising cylinders and pistons submitted to the pressure of the delivered fluid, said pivoting shaft and its spherical head having inlet and outlet channels provided therein and the inner frame having ports provided therein and arranged for cooperating with the channels of saidy pivoting shaft for the passage of the uid enter- Louis sAussARD. ANDR sAUssARD.

able chambers formed between. said sliding`-

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