DE2733687A1 - HYDRAULIC AXIAL PISTON MACHINE - Google Patents

Description

_ ₅ _ 1733687

The invention relates to a hydraulic axial piston machine according to the preamble of the main claim. Such hydraulic axial piston machines can be designed either as a pump or as a motor.

Axial piston pumps have a disk with which the axial piston interact and which either can be designed as a swash plate or as a swash plate or as a race and that during pumping is inclined at an angle to the pump shaft · The axial pistons usually have one each Slide shoe on which the latter is mounted with a spherical part in the piston and with a flat sliding surface rests against the inclined disk · As already mentioned, the inclined disk can be used as a simple swashplate be designed, in which case it is at an invariable angle of inclination with respect to the pump shaft is inclined, or it may be formed as a swash plate, in which case its inclination with respect to the Pump shaft is variable within certain limits. Such a swash plate can be designed simply, in which case the sliding shoes of the pistons rest directly on the swash plate, or it can be made somewhat more complicated in which Fall them to the one closest to the cylinder block

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Place has a swash plate. When such an axial piston pump is operated, it becomes the axial piston The cylinder block accommodating it is rotated by means of the pump drive shaft and the one on the inclined Axial pistons resting against the disk are thereby moved into and out of their cylinder spaces. Axial piston movement can be used to generate pressure pulses of hydraulic fluid in a pump outlet channel.

It is known that the cylinder chambers pressure fluid via a control disk and the pressure pulses from these cylinder spaces also via this control disk to tap, which has two kidney-shaped openings, which latter are delimited by webs and adjoin a control surface of the cylinder block. This control surface has a number of control slots which corresponds to the number of existing axial pistons and each of these control slots has each connection with the associated cylinder chamber the pump shaft is set in rotation and connected via a hydraulic fluid is supplied to the two kidney-shaped openings, so can at the other of the two kidney-shaped openings a sequence of hydraulic fluid pressure pulses are tapped.

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The cylinder block of such axial piston pumps is exposed to a number of stresses during operation. The reaction forces acting between the axial pistons and the inclined disk have a component that runs normal to the axis of rotation of the cylinder block «Since the control slots normally have a smaller cross-section than the cylinder chambers, the hydrostatic pressure acts within the cylinder chambers of the Hydraulic fluid located in the cylinder block on the tone of the axial piston remote end faces of the Cylinder spaces and consequently pushes the cylinder block towards the control disk. The resultant of these reaction forces falls when these reaction forces are all Cylinder spaces are taken together, not together with the axis of rotation of the cylinder block when a The cylinder chamber group is under higher pressure than another cylinder chamber group. The hydrostatic pressure those located in the kidney-shaped openings Hydraulic fluid that acts on the cylinder block and the hydrostatic pressure of any hydraulic fluid that leaks from the webs delimiting the kidney-shaped openings also have an effect the cylinder block and try to push it away from the control disk. Is that in one of the two kidney-shaped perforations prevailing hydrostatic

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Pressure greater than the hydrostatic pressure prevailing in the other of the two kidney-shaped openings Pressure of the hydraulic fluid, then again the resultant of these forces does not coincide with the axis of rotation of the Axial piston pump together.

In addition to the stresses on the cylinder block just described, there is also the fact that the cylinder block can also be claimed by hydrodynamic forces between it and the control disk are aktiveam. For example, if the circumferential The cylinder block is slightly tilted with respect to the control disk, a wedge-shaped gap is formed between it and the control disk, in which a hydrodynamic "lubricating wedge" builds up. On the other hand, for example, either the control surface of the cylinder block or the end surface of the control disk which together with it forms the contact interface slight unevenness that creates a very small angle between these two surfaces, such a hydrodynamic "lubricating wedge" build up even when the control disk and the control surface with the rotating cylinder block in general run parallel to each other

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So that the transfer of the hydraulic fluid takes place effectively from the control disk to the control surface of the cylinder block across the contact interface or vice versa, the gap between the The webs of the control disk and the control surface of the cylinder block should not be too large. As is known, can the size of this gap can be influenced by the fact that the hydrostatic acting on the cylinder block Forces that try to push it towards the control disk are somewhat greater than the hydrostatic ones Makes forces that try to force the cylinder block away from the control disk, so that a resulting "Contact pressure" remains, which tries to urge the cylinder block towards the control disk. At acquaintances Constructions is this contact pressure, for example, by a thrust bearing ring or by artificially generated hydrodynamic forces counteracted so that the mentioned gap assumes a very specific width without that during operation of the pump an excessive load occurs on the abutting end faces of the cylinder block and the control disk.

The firm belief that by arranging specially designed facilities, the between these two abutting end faces effective

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Must limit pressure load, has led to the known hydraulic axial piston machines are structurally much more cumbersome than they actually are would be necessary *

It will be apparent to those skilled in the art that many of the above in connection with hydraulic axial piston pumps discussed considerations for hydraulic axial piston motors as well Validity are those in which a pressurized hydraulic fluid is applied to a large number of axial pistons acts to thereby cause the motor shaft to rotate.

The object of the invention is to be achieved in hydraulic axial piston machines of the general type set out in the preamble of the main claim, with the same performance, a more compact machine construction than in known machines of this type to achieve and also to achieve that such a machine with regard to the contact interface between the cylinder block and control disk is more resistant to the stresses that occur

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Based on a hydraulic axial piston machine, this task is carried out in the preamble of The general design set out in the main claim, solved by the combination of features forming the characterizing part of the main claim "

In connection with the expression "complete mutual interfacial contact" as used here, let also notes that it is to be understood as meaning a "rubbing" and "lubricating" contact, in which a Boundary layer lubrication, for example, through the between hydraulic fluid present on the two contacting surfaces is effected. This condition forms a contrast to the state in which the control surface of the cylinder block and the control disk "none "Touch" with each other, because between the two opposite end faces of both Parts of a comparatively thick lubricant film is located, which a hydrodynamic on these surfaces or exerts hydrostatic pressure · It becomes special pointed out that between axial piston pumps, in which these two surfaces in operation with each other Contact, and other axial piston pumps that are designed so that im Operation only ever momentary area

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contact between these surfaces occurs, however would not withstand such surface contact for long periods of time. On the latter Axial piston pump type is not related to the present invention. The specialist working in the field It should also be clear that in axial piston pumps, in which the two surfaces mentioned in operation are "in contact" with one another in the manner described above within the meaning of the invention, in general nevertheless a slight local hydrodynamic lubrication and slight mutual surface lifting occurs, in particular due to the surface roughness of these two surfaces in the micro range caused.

According to a preferred embodiment of the invention, one of the two surfaces of the cylinder block and the control disk that are in contact with one another is formed on a body made of a plastic with a low coefficient of friction of about 9.1 compared to steel and with a high pv value, as he does for example under the name "GLAMAT 58" in the trade. The properties of this material are in some respects similar to those of known thermoplastics and in other respects also to those of the materials described in

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harden the heat. This material is particularly resistant to the conditions that occur during Operation of an axial piston pump occur and which are expressed in particular in the fact that the operating temperature is higher than the outside temperature and that the rotating cylinder block is pressed in the presence of a hydraulic fluid on this material. In this preferred embodiment of the invention, there is the other of the two surfaces in contact with each other from steel.

In a modification of this, according to a further preferred embodiment of the invention, one of the two can be in interfacial contact Surfaces of the cylinder block and the control disk be formed on a body which consists of a sprayable fluorine-plastic containing polytetrafluoroethane and is called "XYLAN 1010" in the Trading is.

Finally, a material suitable for such purposes should also be a metal alloy with a high Chromium content and a Vickers surface hardness of 1200 as well as a low coefficient of friction of 0.1 compared to steel "DRAYLOY" is on the market.

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According to the invention, the mentioned materials can also be used on the Qleitflächen of Qleitschuhe or on the Qleitflächen a swash plate, swash plate or a race application, because also with respect to Similar points of view apply to these surfaces, as explained above in connection with the control disk and the control surface of the cylinder block For example, use sliding shoes that have only a single web, i.e. in which the guide surfaces do not have any separate web surfaces, whereby this web is placed on a plastic with a low coefficient of friction of about 9.1 compared to steel and with a high pv value, as it is known, for example, under the name "QLAMAT 58" is commercially available, the existing annular surface of the swash plate, swash plate or the raceway runs · In A modification of this can also be the catwalk of the sliding surface of the guide shoe made of a plastic material with a coefficient of friction of approximately 9.1, which is lower than that of steel and with a high pv value, as it is in the trade under the name "GLAMAT 58", for example, in which case the counter surface in question is preferably made of steel.

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The machine shaft and the cylinder block of the machine are preferably mounted in a cylindrical support bushing, the center of which (i.e. the center of the longitudinal center plane) lies at a point where the Plane of the resultant of the reaction force components normal to the shaft axis between the Axial piston and the inclined swash plate etc. intersects this shaft axis. Located in the middle of the Support bushing at this point, the cylinder block does not tend to tilt under the action of this resultant.

The control disk and the control surface of the cylinder block are preferably designed and arranged so that when the machine is in operation Resulting of the effective hydrostatic forces between the cylinder block and the control disk in the essentially interacts with the resultant of the hydrostatic pressure forces, which on the of the Axial piston remote end faces of the associated cylinder chambers of the cylinder block act «act the Resultant opposites in the manner just given, so the cylinder block also has less tendency to tilt with respect to the control disc. Usually these two are

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oppositely acting resultant not be of the same size and this is also desirable, because in operation the machine must have a pressing force that tends to come into contact with the cylinder block to hold the control disk.

The hydraulic axial piston machine according to the invention has advantages over known axial piston machines the general design presented at the beginning of the technical progress that the just mentioned contact pressure completely through the mutual contact between Control disk and control surface of the cylinder block can be added without a for this purpose special external pressure bearing must be provided or it must be ensured that this contact pressure is compensated by hydrodynamic counter-forces · This has the consequence that the hydraulic axial piston machine according to the invention are designed to be much more compact with regard to their construction than was previously possible.

The control surface of the cylinder block and the control disk can generally be flat, wherein the control disk has raised webs which the kidney-shaped openings of the control disk

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limit and these webs adjoin the flat surface of the control surface of the cylinder block.

As a modification of this, these two surfaces can be designed as spherical surfaces, the spherical centers of which coincide completely or approximately. The center of the imaginary sphere that determines the spherical contact interface between the control disk and the control surface of the cylinder block can be on that side of this contact interface on which the cylinder block is also located. The use of such spherical surfaces has the consequence that the machine is less sensitive to rough tolerancing of the dimensions of its components and also allows rather slight angular deviations between the machine shaft and the control disk. The possibility of such tolerances can significantly reduce the manufacturing and production costs of such machines. If the centers of the imaginary balls are placed on that side of the contact interface on which the cylinder block is also located, the entire arrangement becomes less sensitive to any imprecise mutual alignment between the cylinder block and the control disk. If, on the other hand, the ball centers are placed on the side of the contact

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interface, on which the control disk is also located, the whole arrangement is less sensitive to it the effects of possible forces that try to tilt the cylinder block with respect to the control disk.

The use of Qleitschuhe with only a single web makes it possible to use a larger number of pistons with otherwise the same machine dimensions than is possible with known machines of the same power. For example, it is thus easily possible to manufacture a 21-piston pump. The arrangement of a large number of pistons is advantageous in that it makes it possible to improve the degree of uniformity of the pump, which in turn helps to reduce the operating noise of such a pump.

You can also equip other surfaces of the machine according to the invention, on which a relative movement of several machine parts takes place, with the materials specified above, namely a plastic with a low coefficient of friction compared to steel of about 9 * 1 and with a high ρv value, such as that under the Designation "GLAMAT 58" is in the trade or with a sprayable fluorine plastic of the polytetrafluor

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contains ethane and under the name "XYLAN 1010" in Trade is or with a metal alloy with a high chromium content and a Vickers surface hardness of 1200 as well as a low coefficient of friction of 0.1 compared to steel, which is commercially available under the name "DRAYLOY" is. For example, the spherical surfaces with which the machine sliding blocks in the axial piston are mounted, and the cylindrical Qleitflachen of the axial piston of the machine with linings furnish from such materials. Such coatings can be applied to the individual machine parts, for example be applied by punching or pressing, depending depending on which type of application proves to be easiest for the material in question. One Post-processing of the coatings applied to the relevant machine parts can take place, for example, in the form of electrochemical processing or in the form of spark erosion In some cases these materials also form their own parts of the machine · For example, between of the cylinder block and an end plate of the machine acting as a control disk, an annular body made entirely of one of the specified materials is arranged be·

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The invention will now be described in more detail with reference to the accompanying drawings for example described. In the drawings show:

Fig. 1 is a schematic axial section through an embodiment of a hydraulic axial piston machine according to the invention,

Fig. 2 is a schematic section along the plane A-A in Fig. 1,

3 shows a schematic axial section through a hydraulic axial piston motor according to the invention, and

Fig. I \ a schematic axial section

by a hydraulic axial piston pump according to the invention «

In the hydraulic axial piston machine shown in FIGS. 1 and 2, a machine housing 1 and a control disk 2 closing this housing at the end enclose a cylinder block 3. The cylinder block 3 is rotationally fixed on a machine shaft 4

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attached and can therefore only rotate together with this shaft. The machine shaft and the cylinder block 3 are together in the machine housing 1 on a support bushing 9 and a stationary bushing stored, the latter primarily used to guide the machine shaft, but without essential Absorb forces.

The cylinder block has a multiplicity of cylinder chambers 40. These cylinder spaces are around the perimeter of the cylinder block are arranged around the same distance and also all have the same distance from the axis of rotation of the cylinder block 3, an axial piston 8 is arranged in each of the cylinder chambers 40, each by a piston spring 14 from the cylinder space is pushed out. Each axial piston 8 carries a sliding shoe 7. Between the sliding shoe and the associated axial piston is a ball joint which allows the sliding shoe to move relative to the axial piston can freely adjust in all directions within wide limits. The sliding shoe 7 has a relatively large, generally flat surface, namely the sliding surface, which is on a swash plate 5 is applied, the latter so absorbs the pressure of the piston spring IM. The swash plate 5 can

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do not rotate with respect to the machine housing 1. Located between the machine shaft 4 and the machine housing 1 instead of a relative rotation, the sliding shoes 7 slide over the surface of the inclined Swash plate 5 and consequently the individual axial pistons 8 move in sequence with reference to FIG the individual cylinder spaces 40 inwards or outwards " The extent of the movement of the axial pistons 8, i.e. the piston stroke, can be changed by a Another swash plate 5 is used in the machine, its inclination with respect to the axis of the machine shaft 4 has a different value.

The hydraulic axial piston machine described above in connection with FIG. 1 can be used both as hydraulic Axial piston motor as well as a hydraulic axial piston pump can be operated. Will the machine operated as a pump, the energy supplied to the machine as rotary force via the machine shaft is used used to that located in the cylinder chambers 40 To put hydraulic fluid under pressure and the fluid successively as a result of individual pressure pulses eject from the cylinder chambers 40 in the order in which the swash plate the axial piston 8 one after the other into the cylinder spaces 40

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urges. In the further work flow of the pump hydraulic fluid under lower pressure is supplied to the cylinder chambers MO to the extent that the axial pistons 8 are moved out of the cylinder chambers under the action of the piston springs. In the axial piston machine shown in Fig. 1, the axial pistons 8 move out of the cylinder chambers Ί0 when they move along the swash plate 5 from bottom to top, while the hydraulic fluid located behind the axial piston 8 in the cylinder chambers 40 is pressurized when the pistons move along the swash plate 5 from top to bottom. If the machine is operated as a motor, hydraulic fluid under high pressure is supplied to the cylinder chambers kO ^{, which presses the axial pistons out of the cylinder chambers 1} JO, this supply of pressure fluid to the cylinder chambers taking place in such an order that the machine shaft rotates .

On one end face of the cylinder block made of steel or cast iron, for example, a steel control surface 32 is formed, in which control slots open out, which in turn are connected to bores 31 of the cylinder block, which the latter lead to the cylinder chambers HO and through which these

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Hydraulic fluid is supplied or discharged from these cylinder spaces via the hydraulic fluid.

The control disk 2 has an annular web 33 which lies opposite the control slots 31 opening out in the control surface 32.

From Fig. 2, the construction of the control disk can be seen in detail. In the ring-shaped Web 33 are two kidney-shaped openings 34 and 35 arranged. These kidney-shaped openings are connected to channels 36 and 37, respectively. The web 33 consists of a plastic with a low coefficient of friction compared to steel about 9.1 and with a high pv value, like him for example under the name "QLAMAT 58", which is firmly connected to the control disk, which is otherwise made of steel.

If the hydraulic axial piston machine shown in FIGS. 1 and 2 is operated as an axial piston pump, the machine housing 1 is stationary and the machine shaft 4 is set in rotation about Hydraulic fluid is fed to one of the two channels 36 and 37, each in the order

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passes via the control slots 31 of the control surface 32 of the cylinder block 3 into its cylinder spaces, in which the axial pistons 8 move out of these cylinder spaces kO one after the other. If the axial pistons then begin to move back into the cylinder chambers 40, the hydraulic fluid in the order in which this movement of the axial piston 8 takes place from the cylinder chambers 40 via the contact interface between the control surface 32 of the cylinder block 3 and the annular web 33 into the each other of the two channels 36 and 37 ejected. The operation of the machine as a motor differs from the mode of operation just described in that hydraulic fluid under high pressure is supplied to those of the cylinder spaces into which the axial pistons 8 are pushed more or less so that the high pressure prevailing in the cylinder spaces concerned the axial piston extends in sequence and thereby causes the cylinder block 3 to rotate.

When the machine is in operation, reaction forces occur between the swash plate 5 and the axial piston 8 which are normal to the shaft axis in the manner described above. It can be assumed

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that these reaction forces pass through points, which lie in a plane which the centers of all ball joints between the sliding blocks 7 and the Axial piston 8 contains. The center of the support sleeve 9 lies at a point at which this plane is the shaft axis cuts. The consequence of this is that the reaction forces just described do not result in the endeavor have to tilt the cylinder block 3 in the plane of the drawing in FIG. It is also pointed out that that the cylinder block 3 is supported only by the single support sleeve 9 and that in the vicinity of the Control surface 32 of the cylinder block 3, there is no support bearing.

The between the control surface 32 and the annular Web 33 occurring reaction forces stem from that prevailing in the kidney-shaped openings Fluid pressure that acts on the control surface. As stated above, that of these is Forces exerted pressure around the circumference of the control disc is not uniform, but it changes each time corresponding to the change in the reaction forces that occur between the (! guide surfaces of the sliding shoes and the Sliding surface of the swash plate are effective. The choice of the respective position and shape of the control slots of the

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Cylinder block 3 and the kidney-shaped openings 34 and 35 of the annular web 33 are respectively chosen so that the reaction forces occurring at the contact interface have an "equilibrium position" of the cylinder block 3.

As already stated above, the Resulting of those hydrostatic forces acting on the end faces facing away from the axial piston the cylinder chambers of the cylinder block 3 act and try to move the same in the direction of the control disk to urge, counteracted by the resultant of those hydrostatic pressure forces of the hydraulic fluid, which act from the kidney-shaped openings in the control disc, and from the Hydraulic fluid are exerted, which leaks along the annular ridge of the control disc. Of the The pressure difference between these two resultants forms the contact pressure which the cylinder block 3 urges in the direction of the control disk 2. These two resultants are essentially in one Line and consequently keep the cylinder block in "equilibrium", i.e. they do not generate any forces, trying to get the cylinder block in the drawing plane of the pig. 1 perpendicular and through the axis of the

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Machine shaft H to tilt going plane. In the case of hydraulic axial piston machines, as shown in Figures 1 and 2, an effective contact force between the control surface 32 and the annular web 33 of the control disk 2 can be permitted which is significantly greater than the contact force permitted in previously common machines of this type. For the sake of completeness, it should also be mentioned that the forces exerted by the piston springs 14 are superimposed on this Qesamtanpreßkraft.

The hydraulic axial piston motor shown in FIG. 3 has a motor housing 1 which is closed off by an end plate, the latter at the same time forming the control disk 2. The control disk is held in the motor housing by a snap ring 15 and sealed by an O-ring 16. A motor shaft H is mounted within a stationary bearing bushing and is non-rotatably connected to a cylinder block 3 by means of a spline connection, which in turn is supported by a support bushing 9. The cylinder block 3 extends between the control disk 2 and an inclined swash plate 5 »which in turn is prevented from rotating relative to the motor housing 1 by a dowel pin 21 which is held by a grub screw 20,

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The cylinder block 3 has nine cylinder chambers MO, in each of which there is an axial piston 8 »The ball head is in each of these axial pistons a sliding shoe 7, which the latter has a flat sliding surface, which in turn does not has raised ring area shown, which forms a web over the sliding surface of the swash plate slides. The sliding shoes 7 are held in position by a retaining ring 6. Each sliding shoe 7 has an axial bore 30 through which from the cylinder space belonging to the respective axial piston 8 Hydraulic fluid flow to the interface between the slide shoe 7 and the swash plate 5 for the purpose of lubrication can. Each piston 8 is arranged in the cylinder space behind the piston compression spring 14 in the direction pushed to the swashplate.

Each cylinder ^{chamber 1} JO is connected to the control surface 33 of the cylinder block 3 via a control slot. The orifices of the control slots 31 in the control surface 33 are each circular. The control disk 2 has two kidney-shaped openings which cannot be seen in the drawing and which are each delimited by a raised, annular web 32. This annular web 32 consists of a plastic

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with a low coefficient of friction of about 9.1 compared to steel and with a high pv value, as for example under the name "GLAMAT 58" in stores is "Der The angle of rotation which the control disk assumes with respect to the swash plate 5 is by means of rotation Control disk 2 adjustable, which is held in position by means of an adjusting screw 19.

The support bushing 9 and the fixed bearing bushing 11 are each removed from the interior via lubrication channels 34 of the motor housing 1 is supplied with hydraulic fluid. The center of the support sleeve 9 lies in the plane in which the centers of the ball heads of the sliding blocks lie. The swash plate is with respect to the motor shaft 4 inclined at an angle of 16.

The motor shaft is subjected to axial movements by pressure rings 12 and 13 which interact with a shaft collar 42 prevented. These two pressure rings 12 and 12 are in turn supported by a seal housing 10 in Maintained position, which the latter is fastened to the motor housing by means of screws. A leak of Hydraulic fluid from the housing is passed through an O-ring 17 and through a motor shaft lip seal prevented.

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To operate the engine, hydraulic fluid under high pressure is supplied to the control disk 2 via one of the two kidney-shaped openings. The kidney-shaped opening of the control disk selected for this purpose is that which corresponds to those Axial piston 8 has connection which are pushed farthest into their cylinder spaces by the swash plate 5. The hydraulic fluid under pressure urges the axial piston towards the swash plate 5 and thereby causes the cylinder block and with it rotate the motor shaft 4, the sliding shoes 7 over the swash plate 5 slide. It is assumed that the sliding shoes are supported by a film of liquid which is located between them and the swash plate and which each have a hole 30 with the pressure is fed under which the hydraulic fluid located in the cylinder chamber in question is currently located. This pressure is on the way of the Hydraulic fluid from the control disk 2 into the control slots 31 of the control surface 33 of the cylinder block 3 is of course high. The cylinder block 3 is generally by the pressure in the kidney-shaped openings located hydraulic fluid, which acts on the control surface of the cylinder block, pushed away from the control disk 2 · The

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Dimensions and the position of the control slots are chosen so that the opposing axial forces acting on the cylinder block 3 are essentially in one direction, so that no undesirable tilting moment acts on the cylinder block, although of course as a result of the axial forces triggered by the compression springs Ik a slight tendency of the cylinder block to tilt.

If the pressurized hydraulic fluid acting on the axial piston has moved the piston, the rotation of the cylinder block 3 has moved the cylinder space in question so that it is now connected to the other of the two kidney-shaped openings in the control disk, into which the Further movement of the cylinder block, the hydraulic fluid located therein is ejected. Hydraulic fluid which accumulates radially outside of the cylinder block in the motor housing 1 is withdrawn via non-illustrated exhaust ducts from this housing. A certain accumulation of hydraulic fluid in the motor housing is necessary so that the lubrication channels 3Ί and 35 are fed.

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If you want to operate the hydraulic axial piston machine shown in Pig, 3 as a pump, the A torque is applied to the machine shaft Ί and hydraulic fluid is supplied to those cylinder spaces their pistons are just out of the cylinder chambers move out. For this purpose it is only necessary by loosening the adjusting screw 19 and turning it the control disk 2 relative to the swash plate 5 to make a slight adjustment of the machine.

The hydraulic axial piston machine shown in Fig. 3 has a total displacement of 327.7 ¹ l cm in its cylinder spaces. When operating as a motor or pump, a speed of up to about 2200 rpm is generally maintained. The operating pressure of the hydraulic

2 likiquid reaches values of around 280 kg / cm and the power achieved when the engine is running is about 400 hp.

Numerous parts of the in Pig. 4 shown hydraulic axial piston pump correspond to those des in Pig. 3 hydraulic axial piston motor shown. The parts 15, 19, 20 and 21 shown in FIG. 3 are omitted in Pig "4, but it is on for the The specialist working in the field of course, that

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similar parts in the machine shown in FIG Find application. The control surface 33 of the cylinder block 3 of the axial piston pump shown in FIG. 4 and the surface of the control disk 2 that interacts with it are each designed as spherical surfaces » The angle of inclination of the swash plate 5 with respect to the pump shaft 4 iet by means of a servomotor, generally designated by the reference numeral 36 adjusting tool adjustable.

During operation of the axial piston pump shown in FIG. 4, the pump shaft ¹ J is set in circulation and hydraulic fluid is supplied via that opening in the control disk which is connected to those cylinder chambers whose volume is currently increasing. By rotating the pump shaft, depending on the setting of the swash plate 5, the pistons of those cylinder spaces which are currently in connection with the other of the two kidney-shaped openings drive the hydraulic fluid out of these cylinder spaces into this opening. The displacement and the output of the hydraulic axial piston pump essentially correspond to the machine shown in FIG. An execution not shown in the drawings

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form of a hydraulic axial piston pump, which however is similar in terms of its general construction to the hydraulic axial piston machine shown in Figo, With seventeen cylinders it has a total displacement of 163.87 cm. Their operating speed is around I800 rpm and its power consumption is at one Delivery pressure of 1 * 10.6 kg / cm about 100 hp.

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Claims (8)

PATBNTANWAtT NO-R. HOLZEB PHILIPPINE -WBLSBB-STRASS 14 8000 AUGSBUBG TBLBFOH β1β47β TRLKX 6S3101 ρβίβΐ d M. 598 Augsburg, July 22, 1977 Secretary of State for Industry in Her Britannic Majesty1: Government of the United Kingdom of Great Britain and Northern Ireland, 1, Victoria Street, London SWl, England Hydraulic axial piston machine claims 1) Hydraulic axial piston machine with a control surface having a cylinder block whose opening out into this control surface control slits each with 709885/0907 are connected to one of the cylinder chambers arranged in the cylinder block and to a control disk which forms an interface with this cylinder block control surface with two kidney-shaped openings which, when there is relative rotation between the cylinder block and the control disk, each over this interface get away with each of these cylinder spaces one after the other connection, characterized in that this The control surface (33) and this control disk (2) are arranged and designed so that when there is mutual relative rotation between the cylinder block (3) and the control disk, they always remain in complete mutual interfacial contact. 2. Machine according to claim 1, characterized in that that one of the two surfaces of the cylinder block (3) and the control disk (2) which are in interface contact with one another is formed on a body consisting of a plastic with a low coefficient of friction of about 9.1 compared to steel and a high one pv value, as it is called, for example "GLAMAT 58" is commercially available, or consists of a sprayable fluoroplastic, the polytetrafluoroethane and is on the market under the name "XYLAN 1010". 709885/0907 3. Machine according to claim 1 or 2, characterized in that one of the two mutually in interface contact surfaces on an annular body (32) is formed between the control disc (2) and the control surface (33) of the cylinder block (3) arranged and is provided with openings (34, 35) through which the hydraulic fluid flows into and out of the cylinder spaces (40) of the cylinder block can. 4. Machine according to claim 3, characterized in that that at least a part of the surface of the annular body (32) is formed on a body consisting of a plastic with a low coefficient of friction of about 9.1 compared to steel and a high one pv value, as it is commercially available under the name "QLAMAT 58", for example, or a spray-on value There is fluorine plastic that contains polytetrafluoroethane and is commercially available under the name "XYLAN 1010". 5. Machine according to one of claims 1 to 4, characterized in that the contact interface between the control disc (2) and the control surface (33) of the cylinder block (3) is flat (Figs. 1 and 3). 9 (85/0907 _, _ 1733687 6. Machine according to one of claims 1 to 4, characterized in that the contact boundary surface between the control disc (2) and the control surface (33) of the cylinder block (3) is spherical (Fig. 4). 7. Machine according to claim 6, characterized in that the center point of the dotted ball determining the spherical contact interface between the control disk (2) and the control surface (33) of the cylinder block (3) lies on that side of this contact interface on which the cylinder block is also located lies" 8. Machine according to one of claims 1 to 7 * characterized in that the cylinder spaces (40) of the cylinder block (3) each house pistons (8), in which in turn is mounted in each case the spherical surface of a sliding shoe (7), and that the cylinder block is mounted in a support bushing (9), whose The middle lies in a plane on which the middle of all Qleitschuh spherical surfaces lie 709885/0907