EP1797339A1

EP1797339A1 - Linear drive

Info

Publication number: EP1797339A1
Application number: EP05797083A
Authority: EP
Inventors: Rolf Mintgen; Frank Born; Rainer Massmann; Moritz Starkmeth; Stefan Nissl; Robert Geiger
Original assignee: Stabilus GmbH
Current assignee: Stabilus GmbH
Priority date: 2004-10-08
Filing date: 2005-10-07
Publication date: 2007-06-20
Also published as: CN1965169B; US20080289327A1; WO2006040090A1; CN1965169A

Abstract

The invention relates to a fluid linear drive having a cylinder (1) which is entirely or partially filled with a pressure medium. A piston (2) is arranged inside said cylinder so as to be displaced and has a piston rod (10) which is arranged at one end of the piston (2) and is led out of the cylinder (1) in a sealing manner. The piston subdivides the interior space of the cylinder into a first chamber (6) and a second chamber (7), the piston rod (10) extending through the second chamber (7). A pump (17), which is particularly reversible and by means of which the pressure medium can be pumped into the first chamber (6) and pumped off from the first chamber (6), has a first intake and/or pressure connection (18) and a second intake and/or pressure connection (19). The first intake and/or pressure connection of the pump (17) is connected to the first chamber (6) and the second intake and/or pressure connection is connected to a storage chamber. The pump (17) is mounted in the piston (2) or in or on a bottom of the first chamber.

Description

Patent application

Fluid linear drive

description

The invention relates to a fluid linear drive with a completely or partially filled with a pressure medium cylinder in which a piston with a one-sided arranged on the piston and sealed out of the cylinder led out piston rod is slidably disposed and the cylinder interior in a first chamber and in subdivided a second chamber, wherein the piston rod is passed through the ^" second chamber, with a first suction and / or

Pressure connection and a second suction and / or pressure connection having, in particular reversible, pump through which the pressure medium into the first chamber and out of the first chamber can be pumped out.

Such fluid linear drives form active control elements and can be used for automatic adjustment of flaps and doors or for automatic height adjustment. Applications are conceivable both in a motor vehicle and for height adjustment in furniture.

In addition, a linear actuator for automatic doors is known, which has a cylinder completely extending piston rod, on which a piston is arranged, which divides the cylinder into cylinder halves. A pump is provided here for controlling a movement of the linear drive. The object of the invention is to provide a fluid linear drive of the type mentioned, which is simple in a good efficiency of power transmission and requires a small space.

This object is achieved in that the first suction and / or pressure port of the pump to the first chamber and the second suction and / or pressure port is connected to a storage chamber and that the pump in the piston or in or at a bottom of the first chamber is arranged.

The piston is moved by this fluid linear drive characterized in that with the aid of the pump, the pressure medium is conveyed into or out of the closed chamber designed as a first chamber. As a result, both an extension and a retraction of the piston rod is possible.

By appropriate control of the drive of the pump, in particular an electric motor, the input or Ausschubgeschwindigkeit is controllable.

In principle, an arrangement of the pump would be conceivable separately from the cylinder; Space-saving and the installation and installation of the linear drive simplifying the pump but can be arranged in the piston. However, it also requires little space when the pump is arranged in or at a bottom of the first chamber. The pump can be flanged to the floor, for example.

The pressure medium may be a gas, in particular nitrogen gas.

But it is also possible that the pressure medium is a hydraulic fluid, in particular oil, and the second chamber is connected to a volume compensation chamber.

In this case, space-saving, the second chamber form the storage chamber, whereby an already existing space is utilized.

In at least approximately vertical installation with overhead second chamber, the second chamber divided and the closer to the piston chamber part with Hydraulic fluid to be filled as well as the more distant from the piston chamber part form the volume compensation chamber.

However, in order to be able to install the fluid linear drive independently of position in any position, the first chamber part is preferably separated from the second chamber part by a movable wall, in particular an elastic wall, wherein the movable wall can be a piston-like partition wall displaceable in the cylinder.

The volume compensation space is preferably filled with a gas, in particular nitrogen, which is compressible.

In order to realize a basic thrust, the gas can be under a form.

This makes it possible to compensate for the forces acting on the piston in a defined position.

It leads to a compact design, when the cylinder is enclosed by an annular chamber forming the storage chamber.

In this case, the annular chamber may be connected to the piston rod end of the cylinder with the second chamber.

For the separation of gas and hydraulic fluid, the annular chamber may be separated by a movable wall into a first, the storage chamber forming annular chamber part and a second, the compensation chamber forming annular chamber part.

If the first chamber is connected to the storage chamber via a first biased check valve and / or the storage chamber is connected to the first chamber via a second biased check valve, then an overload protection can be realized.

Reducing space can be arranged in the piston, the first check valve and / or the second check valve. Also requiring little installation space, the first check valve and / or the second check valve may be arranged in the wall of the cylinder between the region of the first chamber which is near the bottom and the annular chamber.

If the pump is a swash plate axial piston pump or a gear pump, in particular an external gear pump, the required installation space is low.

As a pump, other pumps of other types such as an internal gear pump, a piston pump or a diaphragm pump can be used.

For example, for opening flaps, it is particularly advantageous if, when the pump is arranged in or at a bottom of the first chamber in or on the first chamber, a booster piston pressurizable by the pump is arranged to increase the force which can be applied to the piston rod. In particular, an increase in the extension force of the piston and thus of the entire fluid linear drive is achieved in this way without increasing the installed pump power.

A simple structure with only a few additional components results when the boost piston has a larger piston area than the piston and is arranged to act on the piston in the first chamber.

For a simple, permanently secure power transmission from the reinforcing piston to the piston and the piston rod, the piston or the reinforcing piston may have a tappet on its side facing the first chamber piston side.

The reinforcing piston can abut in a retracted position of the piston rod in the cylinder on the plunger, so that even in the first portion of the extension of the piston rod an increased pushing force is available, which is particularly advantageous for opening doors and / or flaps.

The efficiency of the boost piston may be preferably controlled by the first chamber having a pressure medium bypass line for the Reinforcing piston has. The pressure medium can then be pumped from the pump into the first chamber, without any movement of the intensifier piston takes place.

Simplifying the structure of the fluid linear drive, the pressure medium bypass line may have a bypass groove arranged on an inner wall of the first chamber for bridging the intensifier piston. This also makes it possible to control the effectiveness of the gain piston path-dependent.

Advantageously, the required installation space of the fluid linear drive can be reduced and its sealing can be simplified if, when the pump is arranged in or at a bottom of the first chamber, a motor arranged outside the cylinder is provided for driving the pump.

A slip-free, durable transmission of a drive power of the motor to the pump can be obtained by the fact that the pump and the motor are connected to a sealed out of the cylinder drive shaft.

The drive shaft can be sealed in a very inexpensive and low-wear manner with a polytetrafluoroethylene (PTFE) having seal against the cylinder.

Advantageously, the geometric arrangement of the pump and motor can be made flexible and / or an adjustment of the engine output speed to the desired pump drive speed, when the pump and the motor with a first, pump-side shaft portion and a second shaft connected to the first shaft portion by means of a clutch, the motor side Shaft section having drive shaft are connected.

In particular, the sealing of the cylinder can be considerably simplified and have a further increased durability, when the clutch has a non-contact magnetic coupling. In such a case, it is possible to arrange a wall of the cylinder between a first, pump-side coupling element and a second, motor-side coupling element, not is penetrated by the drive shaft, whereby an otherwise required sealing point is eliminated.

The clutch may have a gear coupling or a toothed belt clutch, which in particular gives the possibility of an arrangement of the motor laterally, that is, on one longitudinal side of the cylinder.

A revealing, flexible arrangement of the motor is made possible when the drive shaft has a flexible shaft.

If the engine has a housing which is sealed off from the cylinder, a seal between the drive shaft and the cylinder which satisfies less sealing requirements can be used with such an additional engine seal.

In order to prevent pressure fluid from running out of the cylinder into the housing and thus possibly also into the engine, the housing can be filled with a housing pressure medium. Preferably, the pressure of the housing pressure medium is as large as the pressure of the pressure medium in the cylinder. In order to prevent an overflow of housing pressure medium in the cylinder, a seal of the drive shaft is also provided to the cylinder.

The housing pressure means may conveniently be a gas.

Is an engine capable of running in oil, in particular an electronically commutated

Electric motor, used, the housing pressure means may be an oil, such as a hydraulic oil.

The motor may preferably be an electric motor and have a sealed out of the housing electrical connection. The terminal may for example have a rubber seal for sealing or be cast or injected into the housing, for example. In order to limit the speed of movement of the piston rod can in a connection from the first suction and / or pressure port to the first chamber and / or in a connection of the second suction and / or pressure port, a throttle and a return flow from the first chamber or the Be arranged second chamber blocking check valve.

In this case, preferably, the throttle and the check valve are designed as a throttle check valve.

As an overload protection, the first chamber and / or the second chamber can advantageously be connected to the second chamber and / or the first chamber via a pressure limiting valve.

It leads to a compact and simple construction when the swash plate axial piston pump has a cylinder drum which can be driven rotatably about a rotation axis, in which pump cylinders parallel to the rotation axis are formed, whereby pistons are displaceably arranged in the pump cylinder, which project with one end out of the pump cylinders and supported on a fixed swash plate inclined at an angle to the axis of rotation, suction / pressure bores leading from the piston cylinder opposite ends of the pump cylinder to a fixed control plate against which the cylinder drum is axially supported and with a pressure kidney connected to the pressure port and is provided with a suction connected to the suction kidney, wherein the pressure kidney and the suction kidney concentric to the axis of rotation extend and the control panel side orifices of the suction / pressure holes in the rotational movement of the cylinder drum with the Druckniere and the suction kidney are coverable.

Expensive bearing means can be dispensed with if the cylinder drum has a radially encircling cylindrical surface with which it is rotatably supported in whole or in part in a bearing bore of a stationary pump housing.

Does the cylinder drum on its cylindrical surface on a concentric, radially outwardly projecting bearing ring, with which the cylinder drum is rotatably mounted in the bearing bore, so the fluid friction in the gap between the cylinder barrel and bearing bore reduced, which leads to a reduction in the bearing resistance. This makes it possible to make the drive of the pump smaller.

This is also achieved when the bearing bore has a concentric, radially inwardly projecting bearing ring on which the cylinder drum is rotatably mounted in the bearing bore.

For at least largely avoiding an acting on the cylinder drum tilting moment of the bearing ring is preferably arranged in the control plate near the area.

To carry out the suction stroke of the piston, these can be acted upon in a simple manner by compression springs directly or indirectly against the swash plate, which are supported on the cylinder drum.

The compression springs are preferably arranged in the pump cylinders helical compression springs, which are supported with their one ends to the control-plate-side ends of the piston and with its other ends to the control plate-side bottoms of the pump cylinder.

In order to avoid rubbing of the helical compression springs on the walls of the pump cylinder and thus leading to leakage losses damage and friction losses, the helical compression springs may have a smaller diameter than the pump cylinder.

Damage to the walls of the pump cylinders leading to leakage is also avoided in that the pistons have at their control-plate-side ends a region of smaller diameter than the diameter of the pump cylinder, the region of smaller diameter extending at least over a piston stroke corresponding length.

A centric guidance of the helical compression springs in the pump cylinders is achieved in that the piston-side end of the helical compression springs in a Coaxial hole projects into the piston or surrounds a protruding to the control plate pin-like Koaxialfortsatz the piston.

It leads to a considerable reduction in the friction between the cylinder drum and the control disk when the cylinder drum is axially supported on the control plate via a thrust bearing, in particular an axial rolling bearing.

As a result, a significantly lower design of the power of the drive of the pump and thus a much smaller size is possible, which also leads to a smaller space requirement of the fluid linear drive and a lower energy consumption.

If the thrust bearing is arranged in a radially circumferential groove on the control plate-side end face of the cylinder drum, this leads to a further reduction in the size of the pump and the fluid linear drive.

In the cylinder drum facing the end face of the control plate, one or more concentric relief grooves may be formed, which extend radially inside and / or radially outside of pressure kidney and suction kidney and / or in the region of the second thrust bearing and one or more discharge channels lead to a reservoir ,

Thus both leakage and squeezing oil is discharged as soon as possible after the formation. In addition, this leads to a reduction of the support surface of the cylinder drum on the control disk and thus also to a reduction of friction losses.

In order to keep the effective support surface of the cylinder drum and thus frictional losses and size as small as possible, the suction / pressure holes can be arranged offset relative to the central axis of the pump cylinder radially to the axis of rotation of the cylinder drum.

In order to keep the friction between the piston and the swash plate also as small as possible, it is possible that the pistons are supported on the swash plate via a second thrust bearing, in particular a second thrust roller bearing. Thus, a smaller design of the drive is possible, resulting in a smaller size of pump and fluid linear drive and a lower energy consumption.

Furthermore, it is also possible to dispense with expensive sliding shoes between the piston and swash plate, since only the smallest relative movements between the piston and the swash plate take place.

A low-friction support of the pistons is thereby possible in a simple manner in that the pistons are crowned, in particular hemispherical, at their end resting against the axial bearing.

So that it does not come to a frictional contact between the thrust bearing and the wall of the bearing bore of the pump housing, the second thrust bearing can be arranged radially guided on the swash plate.

In a simple way, this is possible because the cylinder drum facing the end face of the swash plate has an annular or disc-like recess same outer contour as the outer contour of the annular second thrust bearing, in which the second thrust bearing is arranged.

Alternatively, a protruding approach may be arranged on the cylinder drum facing the end face of the swash plate, whose circular cross section corresponds to the cross section of the circular inner contour of the second thrust bearing, wherein the second thrust bearing is arranged with its circular inner contour on the approach.

In order to correctly assign the suction and pressure strokes of the pistons of the suction kidney and the pressure kidney, the swash plate must be precisely aligned with the control plate. For this purpose, in a simple embodiment, the swash plate and / or the control plate via positioning with the pump housing to each other against rotation, for which the swash plate and / or the control plate may have on a voltage applied to the pump housing surface a recess into which the fixedly arranged on the pump housing Protruding positioning. The positioning element is easy to produce if it is a deformation of the pump housing generated by impressions.

It leads to a compact arrangement when the cylinder drum is rotatably driven by a coaxial drive shaft of a drive.

In this case, to compensate for a tolerance-related axial offset of the drive shaft and cylinder drum, the drive shaft via a slot coupling, which is in particular a Oldhamkupplung be coupled with a Koaxialzapfen the cylinder drum.

Frictional losses are further reduced when the washer of Oldhamkupplung is a plastic injection molded part.

Thus, the cylinder drum does not lift off the control plate and thereby leads to leakage, the sum of the cross-sectional areas of each located above the pressure kidney pump cylinder minus the sum of the cross-sectional areas of the suction / pressure holes of these pump cylinders in a ratio of> 1, 8: 1, preferably between 2.0: 1 and 3.3: 1 to the cylinder drum facing surface of the printing kidney.

A ratio of 2.06: 1 has proven to be particularly advantageous.

One way of forming the piston is that the pistons are integrally formed.

But the pistons can also be designed in several parts.

If the piston consists of a cylindrical ring, on one end face coaxial with a spherical, in particular hemispherical support part and on the other end side of a coaxial tube part smaller diameter than the diameter of the

Cylinder ring is fixed, so a good investment in the swash plate and a wear prevention of the pump cylinder in the field of helical compression springs is achieved. The coaxial tube part can be made of a hard, wear-resistant material and manufactured with low tolerances. But it is also possible that the piston consists of a cylinder ring, on one end side coaxial a spherical, in particular hemispherical support member is fixedly arranged.

Another possibility of forming the piston is that the piston is formed of one or a plurality of juxtaposed balls having the same diameter as the pump cylinder, wherein the swash plate next ball partially protrudes from the pump cylinder and the swash plate or the second thrust bearing in attachment.

If there are several balls, the gap losses during the pump stroke are reduced.

Embodiments of the invention are shown schematically in the drawing and will be described in more detail below. Show it

1 shows a first embodiment of a fluid linear drive in section,

2 shows a second embodiment of a fluid linear drive in section,

3 shows a third embodiment of a fluid linear drive in section,

FIG. 4 shows a force-displacement diagram for the fluid linear drive according to FIG. 3,

5 shows a fourth embodiment of a fluid linear drive in section,

Figure 6 shows a fifth embodiment of a fluid linear drive in section and

Figure 7 shows a sixth embodiment of a fluid linear drive in a partially sectioned perspective view 8 shows a first embodiment of a circuit diagram of a fluid linear drive

9 shows a second embodiment of a circuit diagram of a fluid linear drive

10 shows a third embodiment of a circuit diagram of a fluid linear drive

11 shows a cross section of a first embodiment of a swash plate axial piston pump

Figure 12 is a perspective view of the cylindrical drum of the swash plate axial piston pump of Figure 1 from the control plate side

Figure 13 is a perspective view of the cylindrical drum of the swash plate axial piston pump of Figure 1 from the swash plate side

FIG. 14 shows a cross section of the cylinder drum according to FIG. 12

FIG. 15 shows an oblique disk-side view of the cylinder drum according to FIG. 12

FIG. 16 shows a cylinder-drum-side view of the control plate of the swash plate axial piston pump according to FIG. 12

FIG. 17 shows a perspective view of the intermediate part of the slot coupling of the swash plate axial piston pump according to FIG

FIG. 12

Figure 18 is a partial sectional view of a one-piece piston Figure 19 is a partial sectional view of a three-piece piston

Figure 20 is a sectional view of a two-part piston

Figure 21 is a view of a reduced diameter piston at the control panel end

FIG. 22 shows a cross section of a second exemplary embodiment of a swash plate axial piston pump in the region of the swash plate

Figure 23 is a cross section of a third embodiment of a swash plate axial piston pump

Figure 24 is a side view of a first embodiment of a swash plate side thrust roller bearing

Figure 25 is a side view of a second embodiment of a swash plate side thrust roller bearing

Figure 26 is a side view of a third embodiment of a swash plate side thrust roller bearing.

The fluid linear drives shown in Figures 1, 2 have a cylinder 1, 1 ', in which a piston 2, 2' is slidably disposed.

The piston 2, 2 'has on its radially circumferential surface a radially encircling annular groove 3, in which a sealing ring 4 is inserted, which bears sealingly against the inner wall 5 of the cylinder 1, 1'.

By the piston 2, 2 ', the interior of the cylinder 1, 1' in a first chamber 6 and a second chamber 7 is divided. The cylinder 1, 1 'is closed at its one end by a bottom 8, 8' and at its other end by a sealing and guiding unit 9. By a coaxial recess in the sealing and guiding unit 9, a piston rod 10 is displaceably guided tightly, which is fastened with its one end to the piston 2, 2 'and the other end protrudes from the cylinder 1, 1'.

The piston 2, 2 'has a first, biased by a spring check valve 11 which is arranged in a leading from the first chamber 6 to the second chamber 7 first connecting line 12.

Furthermore, in a second connecting line 13, which leads from the second chamber 7 to the first chamber 6, opposite to the first check valve opening a second, biased by a spring check valve 14 is arranged.

The second chamber 7, through which the piston rod 10 is passed, is subdivided into a chamber part 15 which is closer to the piston 2, 2 'and a chamber part 16 which is more remote from the piston 2, 2'.

The first chamber 6 and the piston nearer chamber part 15 are filled with oil, while the piston 2, 2 'remote chamber part 16 forms a filled with gas under pre-pressure volume compensation chamber.

In the embodiment of Figure 1, a reversibly driven pump 17 is arranged in the piston 2, which has a leading to the first chamber 6 first suction / pressure port 18 and a leading chamber part 15 second suction / pressure port 19.

In the embodiment of Figure 2, a reversibly driven pump 17 in the bottom 8 'is arranged. A first suction / pressure port 18 of the pump 17 leads to the first chamber 6, and a second suction / pressure port 19 of the pump 17 leads to the bottom 8 'near the end of the cylinder V enclosing annular chamber 20th

The annular chamber 20 forms a storage chamber whose bottom 8 'nearer area is filled with oil and the opposite end area with gas. At the bottom 8 ' opposite end, the annular chamber 20 is connected by a radial opening 21 in the cylinder 1 'with the chamber part 16.

If, in the embodiment of FIG. 1, oil is sucked in from the chamber part 15 by the pump 17 via the second suction / pressure connection 19 and conveyed via the first suction / pressure connection 18 into the first chamber 6, the piston 2 and with it the piston rod 10 moves in the extension direction.

In the reverse conveying direction, the pump 17 sucks via the first suction / pressure port 18 oil from the first chamber 6 and conveys it via the second suction / pressure port 19 in the chamber part 15, whereby the piston and piston rod 10 are moved in the retraction direction.

The gas in the chamber part 16 provides a volume balance due to its compressibility.

In the embodiment of Figure 2 takes place in the one conveying direction of the pump 17 via the first suction / pressure port 18, a suction of oil from the first chamber 6 and a pumping of the oil through the suction / pressure port 19 into the annular chamber 20, so that Piston 2 'and 10 Kobenstange be retracted.

The reverse conveying direction leads to a movement of piston 2 'and piston rod 10 in the extension direction.

Again, the gas in the chamber part 16 and in the upper part of the annular chamber 20 due to its compressibility for a volume balance.

Increases in an extension movement of the piston 2, 2 'and piston rod 10 acting on the piston rod 10 resistance beyond a certain level of force, also increases the pressure in the first chamber 6 until the first check valve 11 opens against the force of its spring and despite further promotion by the pump 17 oil from the first chamber 6 can flow into the chamber part 15. As a result, the piston 2, 2 'and the piston rod 10 remain in their position and are not moved until the increased resistance acting on them is completed. Similarly, when a retraction movement of pistons 2, 2 'and piston rod 10, the second check valve 14 opens when an increased resistance occurs and allows an oil flow from the first chamber part 15 into the first chamber 6.

This function can be used for example in an application of the fluid linear drive for adjusting flaps and doors, especially in motor vehicles as overload or anti-trap.

In Figure 3, in which - as well as in the following figures - for each corresponding components the same reference numerals as in Figures 1, 2 are used, a fluid linear drive with a cylinder V is shown, which fluid linear drive similar to the fluid Linear drive is constructed according to Figure 2 and a reversibly driven pump 17 at the bottom 8 of a first chamber 6 of the cylinder 1 'has.

A first suction / pressure port 18 of the pump 17 leads to the first chamber 6, and a second suction / pressure port 19 of the pump 17 leads to a bottom 8 near the end of a cylinder 1 'surrounding annular chamber 20th

Here too, this annular chamber 20 forms a storage chamber whose area 8 closer to the bottom is filled with oil and the end area opposite this area is filled with gas. At the opposite end of the bottom 8, the annular chamber 20 is connected by a radial opening 21 in the cylinder 1 'with a piston remote chamber portion 16 of a second chamber 7 of the cylinder 1 ¹ .

The first chamber 6 and the second chamber 7 of the cylinder 1 ¹ are separated by a piston rod 10 having a piston 2 ¹ , which is slidably mounted in the cylinder V. At its periphery, the piston 2 'has a sealing ring 4, the sealing on the Inner wall 5 of the cylinder V is present.

The first chamber 6 and a piston closer chamber part 15 of the second chamber 7, through which the piston rod 10 is passed, are filled with oil, whereas the piston 2 'further chamber part 16 of the second chamber 7 forms a filled with gas under pre-pressure volume compensation chamber. A sealing and guiding unit 9 on the one hand closes the cylinder 1 'on its side facing away from the bottom 8 and on the other hand leads the piston rod 10 sealed out of the cylinder 1' out.

In the first chamber 6, a reinforcing piston 22, which has a larger piston area than the piston 2 ', arranged to increase the force acting on the piston rod 10 force. For this purpose, the piston 2 ¹ on its side facing the first chamber 6 piston side 23 a centrally and perpendicular to the piston 2 'arranged plunger 24. In a retracted into the cylinder 1 'position of the piston rod 10, which position is shown here, the reinforcing piston 22, which is provided at its periphery with an annular groove 25 and a sealing ring 26 disposed therein, is located on the plunger 24.

In the region of the reinforcing piston 22, which divides the first chamber 6 into a piston-side chamber part 27 and a pump-side chamber part 28, the first chamber 6 has a larger diameter than in the region of the piston 2 ', which by a step 29 on the inner wall 5 of Cylinder 1 ^{1 is} reached.

Further, the first chamber 6 is provided with a pressure medium bypass line 30 for the boost piston 22, the pressure medium bypass line having a plurality of bypass grooves 31 arranged on the inner wall of the first chamber 6 and extending in the cylinder longitudinal direction for bridging the boost piston 22.

When pumping in pressure medium into the first chamber 6 by means of the pump 17 via the suction / pressure connection 18 connected to the first chamber 6, a pressure for pushing out the piston rod 10 acts first on the comparatively large piston area of the boost piston 22. This results in a large pushing force provided, which is transmitted from the boost piston 22 via the plunger 24 and the piston 2 ¹ on the piston rod 10.

After the booster piston 22 has traveled a structurally adjustable effective path x, the booster piston 22 reaches into the region of the bypass grooves 31. Here, the booster piston 22 also remains under further pressurization, which flows around the pressure medium conveyed by the pump 17 the boost piston 22 and acts directly on the piston 2 ', which then moves away with the plunger 24 of the boost piston 22.

Upon insertion of the piston rod 10 into the cylinder 1 ¹ , the boost piston 22 is pushed back by the piston 2 'by means of the plunger 24 in its initial position.

About the piston surface and / or the effective path x of the boost piston 22, an adjustment of the extension force of the cylinder 1 ¹ to the required depending on the application and / or desired power demand.

In an exemplary force-displacement diagram shown in Figure 4, in which a Ausschubkraft F of the cylinder 1 'in response to a path s of the piston 2 ^{1 is} shown, the operation of the fluid linear drive of Figure 3 is illustrated. In particular, a drop in the extension force F to a constant force level after the intensifier piston 22 has covered its effective travel x becomes clear.

The following exemplary embodiment according to FIG. 5 also shows a fluid linear drive similar to the exemplary embodiments according to FIGS. 2, 3 with a cylinder 1 'surrounded by an annular chamber 20, out of which a piston rod 10 is led out.

Here is an outside of the cylinder 1 'arranged, designed as an electric motor motor 32 for driving a pump 17 is provided, wherein the pump 17 and the motor with a sealed out of the cylinder 1 ^{1 led} out drive shaft 33 are connected. Compared to the cylinder V, the drive shaft 33 is sealed by means of a PTFE-containing seal 34.

In addition, the motor 32 has a housing 35, which is sealed relative to the cylinder V by means of a seal 36. A cylinder 1 ¹ facing wall of the housing 35 simultaneously forms a wall 44 of the cylinder 1 ', through which wall 44, the drive shaft 33 is led out of the cylinder sealed 1 ¹ sealed. Furthermore are electrical connections 37 for contacting the motor 32 by means of seals 38 sealed led out of the housing 35.

FIG. 6 shows a fluid linear drive which is again similar in structure, with a reinforcing piston 22 being provided in a cylinder ¹¹ having a pressure medium bypass line 30, corresponding to the exemplary embodiment according to FIG.

An outside of the cylinder V arranged as an electric motor motor 32, for example, has a power of 40 W and a diameter of 29 mm, for driving a pump 17 is connected to the pump 17 via a drive shaft. The drive shaft has a first, pump-side shaft portion 39 and a second, motor-side shaft portion 40, which shaft portions 39, 40 are connected by means of a non-contact magnetic coupling 41 formed coupling 45 for torque transmission.

The motor 32 is arranged in a housing 35, which is disposed at a bottom 8 of the cylinder 1 ¹ by means of a non-magnetic sealing wall 42 against the cylinder 1 "and pump 17, is completed.

A further fluid linear drive with a cylinder 1 ', from which a piston rod 10 is fully extended here, is shown in FIG. 7. A motor 17 driving a pump 17 is provided with a housing 35, for example made of an elastic material. The housing 35 is sealed by a seal 36 relative to the cylinder 1 '.

Electrical connections 37 of the motor 32 are sealed out of the housing 35, which also has a mechanical connection 43 for attachment of the fluid linear drive, led out.

In the circuit diagram of a fluid linear drive shown in Figure 8, a reversible pump 17 is connected via its first suction and pressure port 18 to a first chamber 6 of a vertically arranged cylinder 1, which is separated by a piston 2 from a second chamber 7 through which leads a piston rod 10 to the outside. In this connection 47, a throttle 46 and parallel thereto arranged in the direction of the first chamber 6 blocking first check valve 48.

The first chamber 6 is filled with a hydraulic fluid, while the second chamber 7 is only partially filled with hydraulic fluid. The other part of the second chamber 7 is filled with a pressurized gas.

From the second suction / pressure port 19 performs a second connection 49 via a feed pressure from the second suction pressure port 19 check valve 50 to the second chamber 7 of the cylinder 1, wherein also in this connection 49, a throttle 51 and parallel thereto in the direction of the second chamber 7 locking second check valve 52 is arranged. The pilot-operated check valve 50 shuts off a flow in the direction of the pump 17.

From the first chamber 6 continues to lead a third connection 53 via a first pressure relief valve 54 to the second connection 49, which in turn is connected via a second pressure relief valve 55 to the third connection 53.

Due to the two combinations of throttle 46 and check valve 48 and throttle 51 and check valve 52 is a limitation of the speed of the piston 2 and piston rod.

Due to the reversibility of the pump 17, the piston rod 10 can be driven both in the extension direction and in the retraction direction.

In the circuit diagram of a fluid linear drive shown in Figure 9, a pressure port 56 of a non-reversible pump 17 'is connected via a fourth connection 57 to the first chamber 6 of a vertically arranged cylinder 1, which is separated by a piston 2 from a second chamber 7 through which a piston rod 10 leads to the outside. In this connection, a first non-return valve 48 which locks in the direction of the first chamber 6 and a throttle 46 is arranged in series in this connection 57. The first chamber 6 is filled with a hydraulic fluid, while the second chamber 7 is only partially filled with hydraulic fluid. The other part of the second chamber 7 is filled with a pressurized gas.

Behind the throttle 46, a fifth connection 58 branches off from the fourth connection 57, which leads via a solenoid-operated 1/2-way valve 59 and a further throttle 60 to a suction connection 61 of the pump 17 '.

In the unactuated basic position, the 1/2-way valve blocks the valve passage, while in magnetic actuation, the valve passage is open.

The suction port 61 of the pump 17 'is further connected via a sixth connection 62 to the second chamber 7.

From the fourth connection 57, a seventh connection 63 leads to the sixth

Compound 62, wherein in the seventh connection, a third pressure relief valve 64 is arranged.

In this embodiment, an extension movement of the piston rod takes place by conveying hydraulic fluid into the first chamber 6, while for the retraction movement, the piston rod 10 must be acted upon by an external force.

In the circuit diagram of a fluid linear drive shown in FIG. 10, a pressure connection 56 of a non-reversible pump 17 'is connected via a fourth connection 57 to the first chamber 6 of a vertically arranged cylinder 1 which is separated from a second chamber 7 by a piston 2 through which a piston rod 10 leads to the outside.

The first chamber 6 is filled with a hydraulic fluid, while the second chamber 7 is only partially filled with hydraulic fluid. The other part of the second chamber 7 is filled with a pressurized gas. In the connection 57, a check valve 65, which closes a return to the pressure connection 56, and then a solenoid-operated 2/2-way valve 66 are arranged.

In the unactuated position of the 2/2-way valve 66, the pressure connection 56 is connected to the first chamber 6 leading connection 57, in which a throttle 46 and parallel to a blocking in the direction of the first chamber 6 first check valve 48 is arranged.

A leading to the second chamber 7 second connection 49, in which a throttle 51 and parallel thereto in the direction of the second chamber 7 blocking second check valve 52 are arranged in the unactuated position of the 2/2-way valve 66 via this with the suction port 61st the pump 17 'connected.

In the solenoid-operated position of the 2/2-way valve 66, the pressure port 56 of the pump 17 'via the second connection 49 to the second chamber 7 and the first chamber 6 via the fourth connection 57 to the suction port 61 of the pump.

By the 2/2-way valve 66, the piston rod 10 can be driven both in the extension direction and in the retraction direction.

In the embodiments of Figures 8 to 10, the pressure relief valves 54, 55 and 64 provide overload protection, wherein an overload may be due to an excessive load to be moved or by an obstacle in the range of movement of the piston rod 10. The swash plate axial piston pump shown in full or in part in FIGS. 11 to 17 has a cylinder drum 68 rotatably drivable about a rotation axis 67 by a motor 32 '.

In the cylindrical drum 68, five cup-shaped pump cylinders 69 are formed concentrically distributed uniformly distributed about the axis of rotation 67, which extend parallel to the axis of rotation 67 and open with one end to the outside. At the other end, the pump cylinders 69 have bottoms 70.

In the pump cylinders 69 piston 71 are slidably disposed, which protrude with its one end of the pump cylinder 69 and are supported by a sliding shoe 72 via a second Axialwälzerlager 73 at an angle to the axis of rotation 67 inclined fixed swash plate 74. The swash plate 74 is fixedly arranged on a pump housing 75 and protrudes into a bearing bore 76 of the pump housing 75 into which the cylinder drum 68 is rotatably mounted with a bearing ring 121 protruding radially outward on its cylindrical surface.

The corresponding to the swash plate 74 inclined Axialwälzlager 73 also protrudes into the bearing bore 76 and is centered in this. On the side facing away from the bearing bore 76 of the swash plate 74 of the motor 32 is fixed.

At the opposite end of the swash plate 74, the bearing bore 76 is closed by a fixedly connected to the pump housing 75 control plate 77.

In the piston 71 pot-like coaxial holes 78 are formed, which open to the bottoms 70 of the pump cylinder 69 to the outside and in which prestressed helical compression springs 79 are arranged.

The helical compression springs 79 are supported with their one ends on the bottoms of the pump cylinder 69 and act on the cylinder drum 68 against the control plate 77th At their other ends, the helical compression springs 79 act on the bottoms of the coaxial bores 78 and thus hold the pistons 71 with their sliding shoes 72 in abutment with the second axial bearing 73.

On the control plate-side end face of the cylinder drum 68, a radially encircling groove 80 is formed in the radially outer region, in which an axial roller bearing 81 is inserted, via which the cylinder drum 68 is axially supported on the control plate 77.

Of the bottoms 70 of the pump cylinder 69 lead in the cylinder drum 68 parallel to the rotation axis 67 formed suction / pressure holes 82 to the control plate 77. The suction / pressure holes 82 are offset relative to the central axis of the pump cylinder 69 radially to the axis of rotation 67 of the cylinder drum 68 out arranged.

In the cylinder drum 68 facing the front side of the control plate 77, a pressure kidney 83 and a suction kidney 84 are formed, which extend concentrically to the axis of rotation 67 and with which the control panel side mouths of the suction / pressure holes 82 in the rotational movement of the cylinder drum 68 overlap.

With the pressure kidney 83, a pressure port 85 and the suction kidney 84, a suction port 86 are connected, which are formed in the control plate 77.

Furthermore, in the cylinder drum 68 facing the end face of the control plate 77 annular, concentric relief grooves formed, of which a relief groove 87 is disposed radially outside of Druckniere 83 and suction kidney 84 and the other relief groove 88 radially within Druckniere 83 and suction kidney 84.

The relief groove 88 extends radially to the axis of rotation 67 inwards.

A third annular relief groove 89 is disposed in the control plate 77 in the region of the second axial rolling bearing 73. From the relief grooves 87, 88 and 89 lead in the control plate 77 formed discharge channels 90 to a reservoir, not shown.

The sum of the cross-sectional areas 91 of the respective pump cylinder 69 located above the pressure kidney 83 minus the sum of the cross-sectional areas 92 of the suction

/ Pressure holes 82 of these pump cylinder 69 is in a ratio of 2.06: 1 to the cylindrical drum 68 facing surface of the Druckniere 83rd

Parallel to the axis of rotation 67, a position bore 93 is arranged so that it extends to a part in the pump housing 75 and the other part in the swash plate 74. In the position bore 93, a pin of the same diameter is used, which forms a positioning element 94, by the swash plate 74 and pump housing 75 against rotation and are connected to each other in a specific assignment.

At the end facing the swash plate 74, the cylinder drum 68 has an axially projecting coaxial pin 95, which is non-rotatably connected via an intermediate piece 96 of a slot coupling 97 to the drive shaft 33 of the motor 32.

The intermediate piece 96 has at its two ends in each case a strip 98 and 99 which are offset by 90 ° to each other transversely to the axis of rotation 67, wherein the bar 98 in a transverse to the axis of rotation 67 extending corresponding groove 100 of the drive shaft 33 and the bar 99th in a transverse to the axis of rotation 67 extending corresponding groove 101 of the coaxial pin 95 engages.

FIGS. 18 to 21 show further exemplary embodiments of pistons.

FIG. 18 shows a one-piece piston 71 'whose end 102 abutting the axial rolling bearing is hemispherical in shape and which is provided with a coaxial bore 78.

19 shows a piston 71 "composed of three parts, wherein on one end face of a cylinder ring 103 is a hemispherical support part 104 and on the front side another end coaxial tube portion 105 of smaller diameter than the diameter of the cylinder ring 103 fixedly arranged.

Figure 20 shows a two-part piston 71 '", which consists of a cylinder ring 103' and with a coaxially fixed thereto hemispherical support member 104 '.

The piston 71 "" shown in FIG. 21 corresponds to the piston 71 '"of FIG. 20, wherein the end portion 106 of the cylinder ring 103' opposite the support part 104 'has a smaller diameter than the cylinder ring 103' at least over a length corresponding to the piston stroke of the pump ,

Figure 22 shows another embodiment of the area of the swashplate 74 '.

In this case, in contrast to the slot coupling 97 of the embodiment of Figures 11 to 17, the strips 38 'and 39' on the drive shaft 33 'and the coaxial pin 95' and the grooves 100 'and 101' on the intermediate piece 96 'are arranged.

The intermediate piece 96 'is provided at its two ends with a cylindrical extension 107 and 108 which are rotatably supported by radial bearings 109 and 110 in corresponding recesses 111 and 112 of the swash plate 74'. The cylindrical extension 108 is additionally supported via a third thrust bearing 113 on the swash plate 74 '.

The shaft 114 connecting the cylindrical extensions 107 and 108 is surrounded by a shaft seal 116 inserted into a coaxial annular recess 115 of the swashplate 74 '.

The embodiment of a swashplate axial piston pump illustrated in FIG. 23 largely corresponds to the embodiment shown in FIGS. 11 to 17.

Different are the pistons. In Figure 23, the pistons each consist of two juxtaposed balls 117 and 118 of the same diameter as the Pump cylinder 69, wherein the balls 117 partially protrude from the pump cylinder 69 and on the second axial roller bearing 73 in abutment.

At the balls 118 are the helical compression springs 79 directly. FIGS. 24 to 26 show various arrangement examples of the second axial rolling bearing 73 on the swash plate 74.

The embodiment of FIG. 24 corresponds to the embodiment in FIGS. 11 to 17.

In FIG. 25, on the end face of the swashplate 74 facing the cylindrical drum 68, a disk-like depression 119 is formed, into which the second axial rolling bearing 73 is inserted.

In FIG. 26, the end face facing the cylinder drum 68 is the one

Swash plate 74 a protruding cylindrical projection 120 is arranged, which carries the second axial roller bearing 73.

LIST OF REFERENCE NUMERALS

1 cylinder 19 second suction / pressure port r cylinder 20 annular chamber

Piston 21 Radial Orifice 'Piston 22 Boost Piston

Ring groove 23 piston side

Sealing ring 24 rams

Inner wall 25 annular groove first chamber 26 sealing ring second chamber 27 chamber part

Bottom 28 Chamber section Bottom 29 Step Seal and guide unit 30 Pressure medium bypass line

10 piston rod 31 bypass groove 1 first check valve 32 engine

12 first connecting line 32 'motor 3 second connecting line 33 drive shaft 4 second check valve 34 seal 5 piston chamber part closer to the chamber 35 housing 6 piston-chamber part 36 seal

7 pump 37 connection

7 'pump 38 seal 8 first suction / pressure port 39 shaft section Shaft section 63 seventh connection

Magnetic coupling 64 third pressure relief valve

Sealing wall 65 Check valve

Connection 66 2/2-way valve

Wall 67 axis of rotation

Clutch 68 cylinder drum

Throttle 69 pump cylinder

Connection 70 plates first check valve 71 piston second connection 71 'Piston releasable 71 "piston

check valve

Throttle 71 '"piston

second check valve 71 "" piston third connection 72 slide shoe first pressure limiting valve 73 second axial rolling bearing second 74 swash plate

Pressure relief valve

Pressure port 74 'swash plate

fourth connection 75 pump housing

fifth connection 76 bearing bore

1/2-way valve 77 control plate

Throttle 78 coaxial holes

Suction connection 79 helical compression springs

sixth connection 80 groove 81 Axial rolling bearings 101 Groove

82 suction / pressure holes 101 'groove

83 print kid 102 end

84 suction kidney 103 cylinder ring

85 pressure connection 103 'cylinder ring

86 suction connection 104 support part

87 unloading groove 104 'supporting part

88 relief groove 105 pipe part

89 relief groove 106 end region

90 discharge channels 107 cylindrical extension

91 cross-sectional area 108 cylindrical extension

92 Cross-sectional area 109 Radial bearings

93 Positioning hole 110 Radial bearing

94 positioning element 111 recess

95 coaxial pin 112 recess

95 'coaxial pin 113 third thrust bearing

96 adapter 114 shaft

96 'intermediate piece 115 ring recess

97 Slotted coupling 116 Shaft seal

98 bar 117 ball

98 'ledge 118 bullet

99 Bar 119 Deepening

99 'bar 120 approach

100 groove 121 bearing ring

100 'groove F pushing force

s way x effective way

Claims

claims

1. Fluid-ünearantrieb with a completely or partially filled with a pressure medium cylinder in which a piston with a one-sided arranged on the piston and sealed out of the cylinder led out piston rod is slidably disposed and divides the cylinder interior into a first chamber and into a second chamber , wherein the piston rod is passed through the second chamber, with a first suction and / or pressure connection and a second suction and / or pressure connection having, in particular reversible, pump, through which the pressure medium into the first chamber and out of the the first chamber is pumped out, characterized in that the first suction and / or pressure port of the pump (17) to the first chamber (6) and the second suction and / or pressure port is connected to a storage chamber and that the pump (17) in the piston (2) or in or on a bottom (8 ¹ ) of the first chamber (6) is arranged.

2. fluid linear drive according to claim 1, characterized in that the pressure medium is a gas, in particular nitrogen gas.

3. Fluid linear drive according to claim 1, characterized in that the pressure medium is a hydraulic fluid, in particular oil, and the second chamber (7) is connected to a volume compensation chamber.

4. fluid linear drive according to claim 3, dad urch in that the second chamber (7) forms the storage chamber.

5. fluid linear drive according to claim 4, dad u rch in that the second chamber (7) is divided and the piston (2, 2 ') closer chamber part (15) is filled with hydraulic fluid and the piston (2, 2 ') removed chamber part (16) forms the volume compensation chamber.

6. fluid linear drive according to claim 5, dad urch in that the first chamber part by a movable wall, in particular an elastic

Wall is separated from the second chamber part.

7. fluid linear drive according to one of claims 3 to 6, d a d u r c h characterized in that the volume compensation chamber with a gas, in particular with nitrogen, is filled.

8. fluid linear drive according to claim 7, dad urch in that the gas is under a form.

9. fluid linear drive according to one of the preceding claims, dadu rch in that the cylinder (1 ') of a storage chamber forming the annular chamber (20) is enclosed.

10. Fluid linear drive according to claim 9, characterized in that the annular chamber (20) is connected to the piston rod end of the cylinder (1 ') with the second chamber (7).

11. Fluid linear drive according to one of claims 9 and 10, d adurch

characterized in that the annular chamber is separated by a movable wall in a first, the storage chamber forming annular chamber part and a second, the Aususgleichskammer forming annular chamber part.

12. Fluid linear drive according to one of the preceding claims, dadu rch in that the first chamber (6) with the storage chamber via a first biased check valve (11) is connected.

13. Fluid linear drive according to one of the preceding claims, dadu rch in that the storage chamber with the first chamber (6) via a second biased check valve (14) is connected.

14. Fluid linear drive according to one of claims 12 and 13, dadu rch in that the first check valve (11) and / or the second

Check valve (14) in the piston (2, 2 ') are arranged.

15. Fluid linear drive according to claim 10 and one of claims 12 and 13, dadu rch geken Nzeichnet that the first check valve and / or the second check valve in the wall of the cylinder between the bottom near the region of the first chamber and the annular chamber are arranged ,

16. Fluid linear drive according to one of the preceding claims, characterized

characterized in that the pump is a swash plate axial piston pump or a gear pump, in particular an external gear pump.

17. Fluid linear drive according to one of the preceding claims, wherein the pump is arranged in or at a bottom of the first chamber, dad u rch characterized in that in or on the first chamber (6) one of the pump (17) acted upon with pressure medium Reinforcing piston (22) is arranged to increase the force acting on the piston rod (10).

18. Fluid linear drive according to claim 17, characterized in that the reinforcing piston (22) has a larger piston area than the piston (2 ') and in the first chamber (6) on the piston (2 ¹ ) is arranged to be operative.

19. Fluid-linear drive according to one of claims 17 and 18, characterized in that the piston (2 ¹ ) or the reinforcing piston at its the first chamber (6) facing the piston side (23) has a plunger (24).

20. Fluid linear drive according to claim 19, characterized in that in a retracted into the cylinder (1 ¹ ) position of the piston rod (10) of the reinforcing piston (22) on the plunger (24).

21. Fluid linear drive according to one of claims 17 to 20, characterized in that the first chamber (6) a pressure medium bypass line

(30) for the boost piston (22).

22. Fluid linear drive according to claim 21, characterized in that the pressure medium bypass line (30) arranged on an inner wall of the first chamber (6) bypass groove (31) for bridging the reinforcing piston (22).

23. Fluid linear drive according to one of the preceding claims, wherein the pump is arranged in or at a bottom of the first chamber, characterized in that an outside of the cylinder (V) arranged motor (32, 32 ') for driving the pump (17 ) is provided.

24. Fluid linear drive according to claim 23, dad u rch in that the pump (17) and the motor (32) with a sealed from the cylinder (1 ¹ ) led out drive shaft (33) are connected.

25. Fluid linear drive according to claim 24, dad u rch in that the drive shaft (33) with a polytetrafluoroethylene having seal (34) relative to the cylinder (1 ') is sealed.

26. Fluid linear drive according to one of claims 23 to 25, d adu rch characterized in that the pump (17) and the motor (32) having a first, pump-side shaft portion (39) and one with the first shaft portion (39) by means a coupling (45) connected second, motor-side shaft portion (40) having the drive shaft are connected.

27. Fluid linear drive according to claim 26, characterized in that the coupling (45) has a non-contact magnetic coupling (41).

28. Fluid linear drive according to one of claims 26 and 27, characterized in that the clutch comprises a gear coupling or a toothed belt clutch.

29. Fluid linear drive according to one of claims 24 to 28, characterized in that the drive shaft has a flexible shaft.

30. Fluid linear drive according to one of claims 23 to 29, characterized in that the motor (32) has a relative to the cylinder (V) sealed housing (35).

31. Fluid linear drive according to claim 30, characterized in that the housing is filled with a housing pressure medium.

32. Fluid-linear drive according to claim 31, characterized in that the housing pressure means is a gas.

33. Fluid linear drive according to claim 31, dad u rch characterized in that the housing pressure means is an oil.

34. Fluid linear drive according to one of claims 30 to 33, characterized in that the motor (32, 32 ') is an electric motor and a sealed from the housing (35) led out electrical connection (37).

35. Fluid linear drive according to one of claims 30 to 33, dad urch in that the motor (32, 32 ') is an electronically commutated electric motor.

36. fluid linear drive according to one of the preceding claims, dadu rch in that in the first suction and / or pressure port and / or in the second suction and / or pressure port, a throttle and a return flow from the first chamber or the second Chamber blocking check valve is arranged.

37. Fluid linear drive according to claim 36, characterized in that the throttle and the check valve are designed as a throttle check valve.

38. Fluid linear drive according to one of the preceding claims, d ad u rch characterized in that the first chamber and / or the second chamber via a pressure relief valve to the second chamber and / or the first chamber are connected.

39. Fluid linear drive according to claim 16 and one of the further preceding claims, characterized in that the swash plate axial piston pump about a rotational axis (67) rotatably drivable cylinder drum (68), formed in the axis of rotation (67) parallel pump cylinder (69) are, in the pump cylinders (69) piston (71, 71 ', 71 ", 71'", 71 "", 117, 118) are slidably disposed, which protrude with its one end of the pump cylinders (69) and at a supported at an angle to the axis of rotation (67) inclined, fixed swash plate (74, 74 '), wherein of the pistons (71, 71', 71 ", 71 '", 71 "", 117, 118) opposite ends of Pump cylinder (69) suction / pressure holes (82) lead to a fixed control plate (77) against which the cylinder drum (68) is axially supported and connected to one with the pressure port (85) Druckniere (83) and with a suction port (86) connected to the suction kidney (84) is provided, wherein the pressure kidney (83) and the suction kidney (84) concentric with the axis of rotation (67) extend and the control panel side openings the suction / pressure holes (82) can be covered during the rotational movement of the cylinder drum (68) with the pressure kidney (83) and the suction kidney (84).

40. Fluid linear drive according to claim 39, characterized in that the cylinder drum (68) has a radially encircling cylindrical outer surface, with which they completely or partially in a bearing bore (76) of a fixed

Pump housing (75) is rotatably mounted.

41. A fluid linear drive according to claim 40, dadu rch in that the cylindrical drum (68) on its cylindrical surface a concentric, radially outwardly projecting bearing ring (121), with which the

Cylinder drum (68) is rotatably mounted in the bearing bore (76).

42. Fluid linear drive according to claim 40, characterized in that the bearing bore has a concentric, radially inwardly projecting bearing ring, on which the cylinder drum is rotatably mounted in the bearing bore.

43. Fluid-linear drive according to one of claims 41 and 42, characterized in that the bearing ring (121) in the control plate (77) near the area is arranged.

44. Fluid linear drive according to one of claims 39 to 43, characterized in that the pistons (71, 71 ', 71 ", 71'", 71 "", 117, 118) by compression springs directly or indirectly against the swash plate (( 74, 74 ') are acted upon, which are supported on the cylinder drum (68).

45. Fluid linear drive according to claim 44, characterized in that the compression springs in the pump cylinders (69) arranged helical compression springs (79) are, with their one ends at the control plate side ends of the piston (71, 71 ', 71 ", 71' ", 71" ", 117, 118) and are supported at their other ends on the control plate-side bottoms (70) of the pump cylinder (69).

46. Fluid linear drive according to claim 45, characterized in that the helical compression springs (79) have a smaller diameter than the pump cylinder (69).

47. Fluid linear drive according to one of claims 45 and 46, characterized in that the pistons (71 ", 71" ") at their control-plate-side ends (106) have a region of smaller diameter than the diameter of the pump cylinder (69), wherein the region of smaller diameter extends at least over a piston stroke corresponding length.

48. Fluid linear drive according to one of claims 45 to 46, characterized in that the piston-side end of the helical compression springs (79) in a coaxial bore (78) in the piston (71, 71 ', 71 ", 71'") protrudes or a to Control plate protruding peg-like Koaxialfortsatz the piston encloses.

49. Fluid-linear drive according to one of claims 39 to 48, characterized in that the cylinder drum (68) via a thrust bearing, in particular an axial roller bearing (81) on the control plate (77) is axially supported.

50. A fluid linear drive according to claim 49, dadu rch in that the thrust bearing (81) is arranged in a radially circumferential groove (80) on the control panel side end face of the cylinder drum (68).

51. Fluid linear drive according to one of the preceding claims, dadu rch in that in the cylinder drum (68) facing the end face of the control plate (77) one or more concentric relief grooves (87, 88, 89) are formed, which are radially inside and or radially outside of pressure kidney (83) and suction kidney (84) and / or in the region of the second axial bearing (73) and of which one or more discharge channels (90) lead to a reservoir.

52. Fluid-linear drive according to one of claims 39 to 51, characterized in that the suction / pressure bores (82) relative to the central axis of the pump cylinder (69) are arranged offset radially to the rotational axis (67) of the cylinder drum (68).

53. Fluid linear drive according to one of claims 39 to 52, characterized in that the pistons (71, 71 ', 71 ", 71'", 71 "", 117) via a second thrust bearing, in particular a second axial roller bearing (73). on the swash plate (74, 74 ') are supported.

54. Fluid-linear drive according to claim 53, characterized in that the pistons (71 ', 71 ", 71'", 71 "", 117) are formed on their at the second thrust bearing (73) adjacent end spherical, in particular hemispherical.

55. Fluid linear drive according to one of claims 53 and 54, dadu rch in that the second thrust bearing (73) guided radially on the swash plate (74, 74 ') is arranged.

56. Fluid linear drive according to claim 55, dadu rch in that the cylinder drum (68) facing the end face of the swash plate (74) has an annular or disc-like recess (119) of the same outer contour as the outer contour of the annular second thrust bearing (73), in which the second thrust bearing (73) is arranged.

57. Fluid linear drive according to claim 55, dad u rch in that on the cylinder drum (68) facing the end face of the swash plate (74) a protruding projection (120) is arranged, whose circular cross section corresponds to the cross section of the circular inner contour of the second thrust bearing , wherein the thrust bearing is arranged with its circular inner contour on the approach.

58. Fluid linear drive according to one of claims 40 to 57, characterized in that the swash plate (74) and / or the control plate (77) via positioning elements (94) with the pump housing (75) are connected to each other against rotation.

59. Fluid linear drive according to claim 58, characterized in that the swash plate (74) and / or the control plate (77) on a bearing on the pump housing (75) surface having a recess into which the fixedly arranged on the pump housing positioning element ( 94) protrudes.

60. Fluid linear drive according to claim 59, characterized in that the positioning element is a deformation of the pump housing generated by impressions.

61. Fluid-linear drive according to one of claims 39 to 60, characterized in that the cylinder drum (68) by a coaxial drive shaft (33) of a drive is rotatably driven.

62. Fluid linear drive according to claim 61, characterized in that the drive shaft (33) via a slot coupling (97) with a coaxial pin ((95,

95 ') of the cylinder drum (68) is coupled.

63. Fluid linear drive according to claim 62, characterized in that the slot coupling is a Oldhamkupplung.

64. Fluid linear drive according to claim 63, characterized in that the intermediate disc of Oldhamkupplung is a plastic injection molded part.

65. Fluid linear drive according to one of claims 39 to 64, characterized in that the sum of the cross-sectional areas (91) of each of the pressure kidney (83) located pump cylinder (69) minus the sum of Cross-sectional areas (92) of the suction / pressure bores (82) of these pump cylinder (69) in a ratio of> 1.8: 1, preferably between 2.0: 1 and 3.3: 1 to the cylindrical drum (68) facing surface the print kidney (83) stands.

66. The fluid linear drive according to one of claims 39 to 65, characterized in that the pistons (71, 71 ') are integrally formed.

67. The fluid linear drive according to one of claims 39 to 65, characterized in that the pistons (71 ", 71 '") are designed in several parts.

68. The fluid linear drive according to claim 67, characterized in that the piston (71 ') consists of a cylindrical ring (103), on one end side coaxial with a crowned, in particular hemispherical supporting part (104) and on the other end side thereof coaxial tube portion (105) of smaller diameter than the diameter of the cylinder ring (103) is fixedly arranged.

69. Fluid linear drive according to claim 67, dad u rch in that the piston (71 ") consists of a cylinder ring (103 '), on one end side coaxial a spherical, in particular hemispherical support member (104') is fixedly arranged.

70. The fluid linear drive according to claim 67, characterized in that the piston is formed from one or a plurality of juxtaposed balls (117, 118) having the same diameter as the pump cylinder (69), wherein the swash plate (74 ) next ball (117) partly from the Pump cylinder (69) protrudes and on the swash plate (74) or the second thrust bearing in abutment.