WO2015165685A1

WO2015165685A1 - Pressure-operated drive and method for running a pressure-operated drive

Info

Publication number: WO2015165685A1
Application number: PCT/EP2015/057178
Authority: WO
Inventors: Roland MONKA
Original assignee: Siemens Aktiengesellschaft
Priority date: 2014-04-30
Filing date: 2015-04-01
Publication date: 2015-11-05
Also published as: DE102014208241A1; EP3114357A1

Abstract

A pressure-operated drive comprising a cylinder (5, 5a) and a piston (6, 6a) which is mobile relative to the cylinder (5, 5a) has a pressure medium chamber (11a, 11b, 11c, 11d, 11e) for accommodating a pressure medium. The piston (6, 6a) or the cylinder (5, 5a) can be locked in particular depending on a tension or stress of a pressure medium in the pressure medium chamber (11a, 11b, 11c, 11d, 11e). The invention further relates to a method for running said pressure-operated drive.

Description

description

Pressure medium drive and method for operating a pressure medium drive

The invention relates to a pressure medium drive with a cylinder and a piston movable relative to the cylinder, which are drivable relative to each other by mediating a particular fluid pressure medium, wherein between see piston and cylinder at least one serving for receiving a pressure medium pressure medium chamber is arranged.

Such a pressure medium drive is known for example from the published patent application DE 1 490 420. There, a piston is arranged movable relative to a cylinder. A relative movement between the piston and cylinder is used to actuate an electrical switching device. In order to enable a reliable operation of the electrical switching device, in addition to piston and cylinder complex fluid lines, valves, etc. are provided to produce a certain motion profile. On the one hand, such a complex construction requires not inconsiderable space, on the other hand a cost-intensive structure is created due to the complexity.

It is therefore an object of the invention to bring about a construction space-reduced and cost-effective pressure medium drive, which reliably delivers a drive power. According to the invention this is achieved in a pressure medium drive of the type mentioned above in that the piston and / or the cylinder are latched in particular in response to a clamping state of the pressure medium in the pressure medium chamber.

A pressure medium drive serves to cause a movement. For this purpose, the pressure medium drive is preferred to a kine matic chain coupled, which can be set on the pressure medium drive in motion. A piston and a cylinder are movable relative to each other, wherein the piston and the cylinder at least in each case a section

Limit pressure medium chamber. The pressure medium chamber can receive a pressure medium, wherein a relative movement between the piston and cylinder can be effected as a function of the clamping state of the pressure medium. The pressure medium is preferably a fluid pressure medium, for example a gas or a liquid. However, it can also be provided that mechanical pressure means, such as reversibly deformable spring elements, such. As coil springs, leaf springs or elastomeric springs are used. A relative movement of the piston and cylinder is accompanied by a change in the Spannzu- state of the pressure medium. Thus, for example, be provided that the fluid pressure medium within the pressure medium chamber is compressed (stretched), whereby energy is introduced into the pressure medium (clamping). For the purposes of this application, a clamping (eg, a compression) is to be understood as meaning the introduction of energy into the pressure medium, with a release (for example a decompression) of an extraction of energy from the pressure medium for purposes of propulsion understand. A piston-cylinder arrangement, for example, by a compression, ie by an overpressure in the pressure medium chamber or by a decompression, ie, for example, a negative pressure in the pressure fluid chamber can be stretched to drive a relative movement between the piston and cylinder. In order to increase forces that can be generated with the pressure medium drive, the parallel use of compression and decompression for tensioning and relaxing can also be provided. Thus, a relative movement between piston and cylinder can be driven, for example, by a negative pressure in a first pressure medium chamber and at the same time by an overpressure in a second pressure medium chamber. By a latching of the piston and / or cylinder any relative movement between the piston and cylinder is prevented. It can be provided that both the piston and the cylinder are each latchable, but it can also be provided that only the piston or the cylinder is verklinkbar. By a latching a relative movement of the piston and cylinder can be locked. By a latching a state of the pressure medium in the pressure fluid chamber can be defined. This prevents unwanted tripping of a relative movement. In particular, a volume change of the pressure medium chamber can be prevented by latching. Only with release of the latch (s) a relative movement between the piston and cylinder is possible. The latch can for example be provided directly on the piston and / or cylinder. However, it can also be provided that within the kinematic chain, which acts on the pressure medium drive, such a latch is arranged. Latching has the advantage that a tension of the pressure medium (eg a compression or decompression) can be built up, in particular within the pressure medium chamber, any, for example too early or too late relative movement between the piston and cylinder prevented by a latch can be. Thus, it is possible, for example, to force a release of the latch or a latching of the piston and cylinder as a function of the clamping state of the pressure medium within the pressure medium chamber. This has the advantage that a release of a relative movement of piston and cylinder takes place only when a defined clamping state, for example a specific overpressure or underpressure of the pressure medium, is present. Thus, for example, to achieve a certain pressure of the pressure medium, a comparatively slow pressure increase or pressure decrease may be provided, since a premature release of a relative movement between the piston and the cylinder is prevented by a latching.

In particular, it can advantageously be provided that with the onset of a tensioning of the pressure medium up to an attainment of Chen a limit value is a latch and with a reaching a defined clamping state of the pressure medium release of a latch occurs. It is thus possible to construct a pressure medium drive from relatively inexpensive elements. The pressure medium can serve as an energy store in the pressure medium drive, wherein a storage of energy, if necessary, takes place only during a short period of time, for example during a tensioning of a pressure medium until a limit value is reached. However, it can also be provided that the pressure medium is tensioned and this clamping state of the pressure medium is maintained so that, if necessary, at the moment of retrieval of a movement that is to be effected by the pressure medium drive, already has a defined clamping state of the pressure medium and, for example, only by a Release of a latch movement can be delivered to a kinematic chain by the pressure medium drive. Regardless of the type of use of the pressure medium as energy storage, whether a longer storage or whether immediately after reaching a limit value triggering a Verkleinkung is provided, such a construction allows a sudden release of a drive movement. Thus, for example, during a relatively long periods of tensioning of the pressure medium against a force caused by a latch force and, if necessary, by

Release of the latching a movement are issued by the pressure medium drive.

A further advantageous embodiment may provide that the piston is an abutment for a movement of the cylinder caused by the pressure medium.

The use of the piston as an abutment makes it possible, for example, to support the piston in a stationary manner, whereupon a relative movement between piston and cylinder can be caused by a movement of the cylinder relative to the bearing of the piston. Furthermore, it can be advantageously provided that the cylinder is an abutment for a movement of the piston caused by the pressure medium.

It can also be provided that the cylinder forms an abutment in order to produce a relative movement of the piston relative to the cylinder. Depending on the structural design, it may also be provided, for example, that different movements of the pressure medium drive use different abutments on pistons or cylinders. It is thus possible, for example, to use the piston as an abutment in a movement in a first direction and to use the cylinder as an abutment in the case of a reversal movement in a second direction. This can be advantageous, in particular in the case of pistons and cylinders of a pressure medium drive mounted rotatably relative to one another, since an increased variability of movements that can be generated by the pressure medium drive can thus be achieved.

A further advantageous embodiment can provide that a tensioning of the pressure medium takes place by a third clamping. An external clamping of a pressure medium is understood to mean that, independently of the cylinder or independently of the piston, a tensioning of the pressure medium, in particular in the pressure center chamber, is caused. This has the advantage that clamping of the pressure medium is possible independently of a relative position of piston and cylinder. Thus, for example, emergency movements of the pressure medium drive can be triggered even in case of failure to trigger at least a partial movement of the pressure medium drive. External clamping can be carried out, for example, by means of external clamping devices connected to the pressure medium. For example, a kinematic chain may be in communication with the pressure medium in the presence of a mechanical pressure medium and Z. B. cause compression or decompression of the pressure medium. When using a fluid pressure medium, it is possible to compress or decompress the fluid, for example, in the interior of the pressure medium chamber via a fluid line.

A further advantageous embodiment may provide that a tensioning of the pressure medium takes place by a self-tensioning. A self-tensioning is understood to mean a tensioning of the pressure medium, which is caused by a relative movement of the piston and cylinder of the pressure medium drive. By a relative movement of the piston and cylinder, a pressure medium in particular in the pressure medium chamber tensioned z. B. compressed or decompressed. For this purpose, a relative movement between the piston and cylinder is caused, wherein after the voltage, the introduced into the pressure medium energy can be used to cause a deliverable from the pressure medium drive movement. For example, it can be provided that a compression is caused by a reduction of the pressure medium chamber. After a release of a latch can be generated by relaxing the pressure medium, a relative movement between the piston and cylinder.

A further advantageous embodiment can provide that the piston and the cylinder are linearly movable relative to each other. A linear movement between the piston and the cylinder makes it possible to use structurally simple pistons and cylinders. Preferably, standardized pistons with a circular cross-section can be used, which are mounted axially displaceably in a form-complementarily shaped cylinder in order to carry out a relative linear movement between cylinder and piston. Such a device has the advantage that a linear movement can be generated in a simple manner can and working strokes with opposite sense of direction can be generated by the pressure medium drive. Thus, it is for example advantageous to effect both a switch-on and a switch-off with one and the same piston-cylinder arrangement.

A further advantageous embodiment can provide that the piston and the cylinder are rotatable relative to each other.

A piston and a cylinder may be rotatably supported relative to each other, this having the advantage that the piston and cylinder can always perform the same relative movement to each other, whereby an endless rotation of the piston and cylinder relative to each other with one and the same sense of relative rotation can be hervorufbar. However, it can also be provided that working strokes are issued with divergent sense of rotation. Furthermore, can be formed by a rotatable movement of the piston and cylinder relative to each other in a simple manner a plurality of pressure medium chambers, for example, work in parallel with pressure and negative pressure of the pressure medium and thereby support each other in their force. Rotary pressure medium drives allow the use of an inherent stress to be particularly advantageous, wherein latching of the piston and cylinder relative to each other is possible. Advantageously, the piston can be configured in the form of a rotary piston, whereby compressions and decompressions of a pressure medium can be built up at the same time in several pressure medium chambers. The piston and the cylinder can each be rotatably mounted, in particular they can be arranged rotatably about the same axis.

A further embodiment may provide that an actuator with a relative to another cylinder movable further piston actuates a latch. The use of a further cylinder and a further piston on an actuator for latching a piston-cylinder arrangement of a pressure medium drive has the advantage that the actuator can be positioned at different positions of the pressure medium drive. For example, the actuator can lock the piston and / or the cylinder of the pressure medium drive directly. However, it can also be provided that the actuator engages in a kinematic chain, which can be driven by the pressure medium drive. It can be advantageous in this case if the actuator uses a similar pressure medium, such as that used in the pressure medium chamber of the pressure medium drive. This makes it possible in a simple manner, for example, to use a state of the pressure medium (decompressed or compressed) of the pressure medium drive for controlling the pressure medium in the actuator. For example, a control of the actuator can be carried out in a simple manner when using a fluid pressure medium via a differential pressure measurement. This can be done, for example, hydraulically, pneumatically, etc. This is a disturbance insensitive

System created to control a latching of the pressure medium drive.

A further advantageous embodiment can provide that the pressure medium drive acts as a drive of an electrical switching device.

An electrical switching device has a current path which can be separated or switched through by means of switching contacts that can be moved relative to one another. electrical

Switching devices are, for example, circuit breakers, circuit breakers, switch disconnectors, load switches, earthing switches, etc. All of these electrical switching devices share a generation of a movement of a first switching contact piece relative to a second switching contact piece. Of the

Pressure fluid drive can serve to generate a relative movement of the first and second switching contact piece. This can the pressure medium drive via a kinematic chain with at least one of the switching contact pieces of the electrical

Switching device to be connected. A movement is thereby coupled to at least one of the switching contact pieces, so that this can come into galvanic contact with the other switching contact piece or an existing galvanic contact between the switching contact pieces can be resolved. A latching of the piston and / or the cylinder of the pressure medium drive can be provided for example on the kinematic chain, which extends between the pressure medium drive to the at least one switching contact piece.

A further object of the invention is a suitable method for operating a pressure medium drive with a piston and a cylinder and in particular a fluid

Specify pressure medium. According to the invention the object is achieved in a method of the type mentioned above in that

in a pressure medium chamber, a tensioned pressure medium is provided, that

- After release of a latching piston and / or cylinder driven by a relaxation of the pressure medium, a relative movement between the piston and cylinder takes place. With the concern or achievement of a defined

Clamping state (eg reaching a limit value) of a pressure medium in the pressure medium chamber, a release of a latch can be triggered at any time, whereby a relative movement between the piston and cylinder is generated. Preferably, the pressure medium chamber between the piston and cylinder should be arranged. Such a method has the advantage that a compression or decompression (clamping) of the pressure medium can take place during comparatively long periods, whereas a decompression or compression (release) of the pressure medium leads to a generation of a movement of the pressure medium drive within a substantially shorter time Time interval can be done. Thus, it is possible to perform a clamping with cost-effective devices and to ensure a reliable, rapid, in particular sudden, dispensing of a relative movement between the piston and the cylinder on the pressure medium drive. This can be used to avoid costly, bulky or expensive systems.

A further advantageous embodiment can provide that the latch is released when a limit value of a voltage of the pressure medium is reached.

If a latch is released when a voltage limit has been reached, it is possible to carry out a continuous tensioning of the pressure medium in the pressure medium chamber and to allow a release of the pressure medium drive immediately after reaching a limit value. As a result, the pressure medium chamber z only during relatively short intervals. B. subjected to an overpressure or negative pressure. After delivery of a movement by the pressure medium drive, it is not necessary to carry out a renewed tension of the pressure medium in the pressure medium chamber immediately. As a result, a permanent load on the pressure medium drive z. B. prevented by over or under pressures in the pressure fluid chamber. For example, only when retrieving a movement of the pressure medium drive, a voltage of

Insert pressure medium in the pressure medium chamber, which is built up until a limit is exceeded and a latch is released when the limit value is exceeded. For example, with a completion of the movement of the pressure medium drive or a release of the latching a clamping of the pressure medium in the pressure medium chamber to produce a movement can be stopped.

When a limit value is reached, the pressure medium has a minimum voltage in order to produce a required movement profile of a relative movement between the piston and the cylinder. For example, a relative movement with a certain minimum speed and a certain minimum stroke are generated. A release of the latch as a function of the clamping state of the pressure medium, in particular in a pressure medium chamber between the piston and cylinder, ensures a reliable, consistent operation of the pressure medium drive. Even after a large number of movements initiated by the pressure medium drive, a minimum relative speed between the piston and the cylinder as well as a minimum stroke can be achieved by maintaining z. B. a Mindestgrenzwer- tes an overpressure or negative pressure can be ensured.

A further advantageous embodiment can provide that the pressure medium is tensioned by an external clamping in the pressure medium chamber.

By means of a third clamping, a pressure medium in the pressure medium chamber can be tensioned (eg increased in its pressure (compressed) or reduced in pressure (decompressed)). This is advantageous because such a relative movement of the piston and cylinder are not necessary to cause a tensioning of the pressure medium in the pressure medium chamber. The pressure medium chamber, for example, maintain a constant volume, which can be done by a secondary system clamping of the pressure medium in the pressure medium chamber.

Furthermore, it can be advantageously provided that the pressure medium is tensioned by a self-tensioning in the pressure medium chamber.

An inherent tension of the pressure medium in the pressure medium chamber is caused by a relative movement of the piston and cylinder, said movement being driven from the outside, so that z. B. a compression or decompression for clamping the pressure medium, for example, by a volume change of the pressure medium space is generated. In particular, with rotatably movable piston and cylinder can this may be advantageous, for example, to produce a continuously continuous rotational movement with one and the same relative sense of rotation between the piston and cylinder. A further advantageous embodiment may provide that after / during a tension and before a relaxation, the tensioned pressure medium acts as an energy store.

The tensioned pressure medium can act as an energy store, for example, to effect a slow build-up or a slow compression or decompression (clamping) of a fluid and to return this work done for shorter periods of time (relax). Thus, pressure medium actuators are constructible, which can be controlled with low power and in turn can deliver high drive power. The pressure medium can act, for example, as an energy store and hold a voltage for longer periods. However, it can also be provided that the pressure medium stores energy only as long as z. B. a compression or decompression has reached a certain limit and then a drive movement of the pressure medium drive can be issued immediately following.

A further advantageous embodiment can provide that in the pressure medium chamber, an increasing voltage of the pressure medium takes place and when a clamping threshold is exceeded, a release of the latch takes place.

A control of the latch on reaching or exceeding a limit value of compression or decompression (clamping) of the pressure medium has the advantage that immediately upon reaching the limit value, a movement of the pressure medium drive can be issued. Furthermore, the latching of the piston and / or cylinder as a function of a clamping limit value has the advantage that no undesired premature or delayed movement of a piston or a cylinder relative to the cylinder or piston is produced. can be fen. By a latching function of a clamping state of the pressure medium a secure power delivery is ensured at the pressure medium drive. In this way, the pressure medium drive can couple a similar motion profile, for example in a kinematic chain, even in the repeated case. The clamping state of the pressure medium can also be represented by relative positions of the piston / cylinder of the pressure medium drive or the kinematic chain. In particular, when using an internal stress of the pressure medium of the clamping state is recognizable by the position of the piston and cylinder.

A further advantageous embodiment can provide that the relative movement between the piston and cylinder moves a kinematic chain, on which a switching contact piece of an electrical switching device is arranged.

A kinematic chain is an operative connection between a pressure medium drive and a switching contact piece of an electrical switching device. Through the kinematic chain, it is possible to remove the location of the generation of movement of the switching contact piece, and to transmit via transmission elements movement. Transmission elements of the kinematic chain may be, for example, shafts, levers, gears, racks, etc. In this kinematic chain, for example, a latch for a piston and / or a cylinder engage, so that a relative movement between the piston and cylinder is prevented with effective latching.

A switching contact piece of a switching device can be arranged, for example, surrounded by an encapsulating housing, wherein the kinematic chain passes through the encapsulating housing, so that the pressure medium drive can be arranged outside the encapsulating housing. Accordingly, a latch can be arranged outside of the encapsulating. For example, it can be provided that the kinematics see chain sealingly penetrates the encapsulating, so that, for example, a fluid-tight encapsulating housing can be formed, which is penetrated by the kinematic chain, wherein a passage of a fluid is prevented due to a seal.

In the following, an embodiment of the invention is shown schematically in a drawing and described in more detail below.

It shows the

Figure 1 is a Kapselungsgehäuse with a pressure medium drive, the

Figures 2 to 6 different relative positions of the piston and

Cylinder of a pressure medium drive and the

Figure 7 shows a further embodiment of a

Pressure medium drive.

FIG. 1 shows a pressure medium drive of an electrical switching device. The electrical switching device has an encapsulating housing 1. The encapsulating housing 1 surrounds a first and a second switching contact piece 2 3. The first and the second switching contact piece 2,3 are movable relative to each other, wherein the second switching contact piece 3 is mounted stationary and the second switching contact piece 3 is movable. The second switching contact piece 2 is connected via a kinematic chain 4 with the pressure medium drive. The pressure medium drive in turn has a cylinder 5 and a piston 6. The cylinder 5 and the piston 6 are movable relative to each other and arranged outside of the encapsulating housing 1. Via a drive shaft 7, which serves as part of the kinematic chain 4, a rotary movement through a wall of the encapsulating housing 1 is transferable. The drive shaft 7 is fluid-tight in the cap selungsgehäuse 1 used, so that the switching contact pieces 2, 3 are separated by means of the encapsulating 1 hermetically from the environment of the encapsulating 1. About the relatively movable switching contact pieces 2, 3 are connected to this phase conductor sections z electrically connected to each other or electrically separable from each other. By way of example, an arrangement of a single phase conductor within the capsule housing 1 is shown schematically in FIG. However, it can also be provided that a plurality of phase conductors can be switched together by means of one and the same pressure medium drive. For example, it is possible to arrange several phases of a multi-phase electric power transmission system, for example, a three-phase AC voltage system within one and the same encapsulating 1 insulated electrically and to move the respective switching contact pieces 2, 3 of the individual phase conductors synchronized via the pressure medium drive. For electrical insulation of the phase conductor or of the switching contact pieces 2, 3, the interior of the encapsulating housing 1 can be filled with an electrically insulating fluid. Preferably, this may be an electronegative gas, such as

Schweiel hexafluoride, nitrogen, carbon dioxide or mixtures with these gases. Preferably, the encapsulating housing 1 can be designed as a pressure vessel, so that the electrically insulating fluid can also be placed under an overpressure in the interior. As a result, the wall of the encapsulating housing 1 forms a pressure-resistant barrier, which must withstand the differential pressure between the interior of the encapsulating housing 1 and the exterior of the encapsulating housing 1. In addition to a gaseous use of an electrically insulating fluid, this can also be present in liquid form; if appropriate, gaseous and liquid states can also be present within the encapsulation housing 1 at the same time. The encapsulating housing 1 can be made electrically conductive or electrically insulating. The encapsulating housing 1 can be connected to other identically constructed or alternatively designed encapsulating housings become. For this purpose, in particular flange openings which are complementary in shape with flange openings of further encapsulating housings are suitable. Thus, it is possible to continue the switchable in the interior of the encapsulating 1 phase conductor in other encapsulating housings.

In the interior of the encapsulating housing 1, the drive shaft 7 is connected as part of the kinematic chain with a crank arm 8. The crank arm 8 is rigidly connected to the drive shaft 7, so that a rotational movement of the drive shaft 7 is transmitted to the crank arm 8. On the crank arm 8, a connecting rod is guided within a slot of the crank arm 8. The connecting rod is connected to the movable first switching contact piece 2.

Outer casing side on the encapsulating housing 1, the piston 5 and the cylinder 6 of the pressure medium drive are mounted. Both the piston 6, and the cylinder 5 are rotatable independently of each other, wherein the piston 6 is rigidly connected to the drive shaft, so that a movement of the piston 6 always on the drive shaft 7 and the kinematic chain 4 and finally on the movably mounted first Switch contact piece 2 is transmitted. The cylinder 5 is also rotatably mounted, wherein it is rotatable about the same axis as the piston 6. In the figure 1 and in Figures 2 to 6, in which a sequence of movement of a pressure medium drive of Figure 1 is shown, the piston 6 is marked for better visibility with a broken full line. The cylinder 5 is marked with a closed solid line. In the figure 1 and in Figures 2 to 6, respectively, the end faces of the cylinder 5 are cut free to see located inside pressure fluid chambers IIa, IIb, 11c, and their volume changes. FIG. 2 shows the position of piston and cylinder 5, 6 in the switched-on state of the electrical switching device (as in FIG. 1). To the electrical switching device To turn off, a sequence of movements as shown in Figures 2 to 4, to perform.

Below is a description of a Ausschaltbewe- 5 tion of the pressure medium drive with reference to Figures 2, 3 and 4.

In the figure 2, the structure of the cylinder 5 is recognizable. The cylinder 5 has a hollow circular cylindrical cross-section, wherein the cylinder 5 is rotatably mounted to the drive shaft 7. In order to divide the interior of the cylinder 5) len, this has two lying on a diameter of the cylinder 5 dividing walls 9. The dividing walls 9 each form a cylinder bottom. The dividing walls 9 are fluid-tight and rigidly fixed on the inner shell side on the cylinder 5, wherein the dividing walls 9 with their drive 15 shaft 7 facing ends sealingly abut the piston 6. For this purpose, the piston 6 has centric a sleeve-like structure, which is mounted on the drive shaft 7 angularly fixed. Radial fortragend the piston 6 is equipped with piston walls 10. The piston walls 10 are arranged lying on a diameter of the cylinder 5 5 lying. The piston walls 10 are on the inner side of the cylinder 5 sealingly. The cylinder 5 is each closed at the end, so that closed pressure medium chambers IIa, IIb, 11c, Lld between the piston 6 and cylinder 5 are arranged. Fertilize through the Trennwan- 25 9 and the piston walls 10 are within the cylinder 5 between the piston 6 and cylinder 5 respectively

annular sector-shaped pressure medium chambers IIa, IIb, 11c, lld formed.

In order to initiate a drive movement by means of pressure medium drive, the piston 6 is initially blocked in its movement by a latch. By means of an external force, the cylinder 5 is set in rotation, whereby a first group of pressure medium chambers IIa, IIb respectively in their volume

35 are reduced and a second group of pressure fluid chambers 11c, Lld are each increased in volume. Consequently, within the first group of printing Middle chambers IIa, IIb there is a pressure medium located there in its pressure, whereas in the second group of pressure medium chambers 11c, lld decompression of a pressure medium located there occurs. In the present case, a gaseous pressure medium is used. After reaching a sufficient compression / decompression in the pressure medium chambers IIa, IIb, 11c, lld the piston 6 is latched by means of a latch not shown in the figures. The volumes of pressure medium contained in the pressure medium chambers IIa, IIb, 11c, 11d store the introduced energy.

In an alternative embodiment can also be provided that instead of a range of stresses described above, a third-party clamping is used, in which case there is a compression / decompression of the pressure medium in the individual pressure fluid chambers IIa, IIb, 11c, Lld from the outside. Also in this case, the pressure medium acted upon by pressure or negative pressure fluid in the pressure medium chambers IIa, IIb, 11c, lld used as energy storage. The volume of the pressure medium chambers IIa, IIb, 11c, lld does not change during tensioning.

Upon reaching a sufficient overpressure / negative pressure in the pressure medium chambers IIa, IIb, 11c, lld a release of the latching of the piston 6 can take place, so that a relaxation of the pressure medium in the pressure medium chambers IIa, IIb, 11c, lld occurs. Consequently, a rotation of the piston 6 takes place about the axis of the drive shaft 7. The cylinder 5 forms an abutment. Due to the rigid connection of drive shaft 7 and piston 6, rotation of the drive shaft 7 takes place, which results in a movement of the movable first switching contact piece 2 from its closed position into an open position. The two switching contact pieces 2,3 are separated from each other. In order to bring about a return movement, that is to say a contacting of the two switching contact pieces 2, 3, starting from the relative position of piston 6 and cylinder 5 according to FIG. 4, first a movement of the cylinder ders 5 made, this movement takes place with the reverse direction, as in a turn-off, so that in the reverse sense now the first group of pressure fluid chambers IIa, IIb decompressed and the second group of pressure fluid chambers 11c, Lld is compressed. The piston 6 is latched. After compression / decompression and reaching a limit value of the compression / decompression in the pressure medium chambers IIa, IIb, 11c, lld, a

Latching of the cylinder 5 take place and the latching of the piston 6 are released, whereby an opposite rotational movement relative to a switch-off can be generated, so that the cylinder 5 and the piston 6 again take the position (Fig. 6), as shown in Figure 2 In this case, the switching contact pieces 2, 3 are contacted with each other (FIG. 1). It can be seen from the exemplary embodiment according to FIGS. 1, 2, 3, 4, 5 and 6 that a latching of piston 6 and cylinder 5 can take place in particular as a function of a compression / decompression present in one of the pressure medium chambers IIa, IIb, 11c, 11d , It can be provided on the one hand that both the piston 6, and the cylinder 5 each for themselves

can be latched, which can also be provided that the piston 6 and cylinder 5 are latched together. In the figure 7 is another embodiment of a

Pressure medium drive shown, in which case a representation of the switching contact pieces 2, 3 was omitted. The electrical switching device essentially corresponds to the representation according to FIG. 1, the drive shaft 7 projecting through the encapsulating housing 1 serving as the interface. Instead of a coupling of a rotatable piston 6 to the drive shaft 7, the use of a piston 6a, as well as of a cylinder 5a is provided in the further embodiment of a pressure medium drive, which are arranged to be linearly movable. The piston 6a of the further embodiment of a pressure medium drive is designed substantially hollow cylindrical, wherein a in the cylinder 5a inserted piston 6a along the cylinder axis is movable. The further embodiment of a pressure medium drive has a pressure medium chamber on which can be filled or emptied via a foreign clamping device 12 with a pressure medium. A fluid pressure medium can be so pressed into the pressure fluid chamber all or removed from the pressure fluid chamber llle. Thus, it is possible that the piston 6a is moved relative to the cylinder 5a. The cylinder 5 a is supported on the encapsulating housing 1. About a further crank arm 8a outside the encapsulating housing 1, a linear movement of the piston 6a in a rotational movement can be changed. The further crank arm 8a is connected outside the encapsulating housing 1 to the drive shaft 7. At the further crank arm 8a, a latch 13 is arranged, in which a pivotable latch 14 is movable into it. The pivotable latch 14 is also fixedly mounted on the encapsulating housing 1. Via an actuator 15, a pivoting movement of the bolt 14 can be initiated. In the present case, the actuator 15 is also designed as a piston-cylinder arrangement which can be actuated via a fluid. The actuator 15 should likewise be mounted on the encapsulating housing 1. By means of the actuator 15 of the latch 14 is retractable into the case 13 and extendable from the case 13. Only after a release of the latch 13 by the actuator 15 is a movement of the piston 6a of the further embodiment of the pressure medium drive possible. Thus, a latch is formed, which engages in a kinematic chain.

In the present case, an operating method is selected such that by means of the external clamping device 12 first an overpressure of a pressure medium in the pressure medium chamber is generated, during which time the bolt 14 under engagement with the further crank arm 8 located in the case 13 a movement of the piston 6a of the further pressure medium drive blocked. Only when reaching a limit value of the compression of the pressure medium within the pressure medium chamber lle an actuation of the actuator 15, which moves the latch 14 out of the case 13, whereby a release of the latching of the piston 6a occurs, whereupon it jumps to the drive shaft. 7 emits. By means of a control device 16, the pressure in the pressure medium chamber can be detected and via the control device 16, upon reaching a limit value of the pressure in the pressure medium chamber, the latch can be released by actuation of the actuator 15.

In order to produce a return movement on the piston 6a, an evacuation of the pressure medium chamber 11e can be provided by means of the external clamping device 12, so that a reverse movement on the drive shaft 7 occurs due to a negative pressure within the pressure medium chamber. If necessary, this can be done without the provision of a latch, since, for example, only one switch-off movement requires a sudden drive movement. According to the embodiment of Figure 7 is the

Trap 13 designed such that with the same latch 14 a latching of the piston 6a takes place both for a switch-on and for a switch-off. However, it can also be provided that an additional piston-cylinder arrangement is provided on the pressure medium drive for a switch-off, so that for the on and off on the drive shaft 7, two separate piston cylinder assemblies are used. These two piston-cylinder arrangements can also turn one each

Have latching, so that only when reaching a certain pressure within a pressure medium chamber, a release of a piston 6a takes place and thus a rapid jump-like movement can be coupled to the drive shaft 7.

Alternatively, it can also be provided that a pressure medium drive with a double-acting piston, a so-called Differential piston is equipped, so that a movement in both the input and in the Ausschalttrichtung can always be performed by positive pressure or negative pressure.

Claims

claims

1. pressure medium drive with a cylinder (5, 5a) and a relative to the cylinder (5, 5a) movable piston (6, 6a), which are drivable relative to each other by mediation of a particular fluid pressure medium, wherein between pistons (6, 6a) and cylinder (5, 5a) at least one serving for receiving a pressure medium pressure medium chamber (IIa, IIb, 11c, lld, ll) is arranged,

d a d u r c h g e k e n e z e i c h e n e, d a s of the piston (6, 6 a) and / or the cylinder (5, 5 a) in particular in response to a clamping state of the pressure medium in the pressure medium chamber (IIa, IIb, 11c, lld, llle) are latched.

2. Pressure medium drive according to claim 1,

d a d u r c h g e k e n e z e i h e s, e s the piston (6, 6 a) is an abutment for a caused by the pressure medium movement of the cylinder (5, 5 a).

3. pressure medium drive according to claim 1 or 2,

d a d u r c h g e k e n e z e i c h e s, d a s s of the cylinder (5, 5 a) is an abutment for a caused by the pressure medium movement of the piston (6, 6 a).

4. Pressure medium drive according to one of claims 1 to 3, d a d u r c h e c e n e z e c h e n e, s t s a clamping of the pressure medium by an external clamping takes place.

5. Pressure medium drive according to one of claims 1 to 3, d a d u r c h e c e n e z e c h e n e, s t s a clamping of the pressure medium by a self-tensioning takes place.

6. Pressure fluid drive according to one of claims 1 to 5, characterized in that the piston (6, 6 a) and the cylinder (5, 5 a) are linearly movable relative to each other.

7. Pressure medium drive according to one of claims 1 to 6, d a d u r c h e c e n e c e s e s, e s of the piston (6, 6 a) and the cylinder (5, 5 a) are rotatable relative to each other.

8. Pressure medium drive according to one of claims 1 to 7, d a d u r c h e c e n e c e s, an actuator (15) with a relative to another cylinder movable further piston a latch (13, 14) actuated.

9. Pressure medium drive according to one of claims 1 to 8, d a d u r c h e c e n e z e i n c e s, the pressure medium drive acts as a drive of an electrical switching device.

10. A method for operating a pressure medium drive with a piston (6, 6a) and a cylinder (5, 5a) and in particular a fluid pressure medium,

d a d u r c h e s e n c i n e s, d a s s

- In a pressure medium chamber (IIa, IIb, 11c, lld, lle) held a tensioned pressure medium that

- After release of a latch (13, 14) of piston

and / or cylinder driven by a relaxation of the pressure medium, a relative movement between the piston (6, 6a) and cylinder (5, 5a) takes place.

11. The method according to claim 10,

The locking is released when a limit value of a tension of the pressure medium is reached.

12. The method according to claim 10 or 11,

characterized in that the pressure medium is tensioned by an external clamping in the pressure medium chamber (IIa, IIb, 11c, lld, lle).

13. The method according to claim 10 or 11,

That is, the pressure medium is tensioned by a self-tensioning in the pressure medium chamber (IIa, IIb, 11c, 11d, 11c).

14. The method according to any one of claims 10 to 13,

d a d u r c h e k e n e s i n e s, the pressure element acts as an energy store after / during a tension and before a relaxation.

15. The method according to any one of claims 10 to 14,

In the pressure medium chamber, a rising tension of the pressure medium takes place and a release of the latch (13, 14) takes place when a clamping limit value is exceeded.

16. The method according to any one of claims 10 to 15,

That is, the relative movement between pistons (6, 6a) and cylinders (5, 5a) moves a kinematic chain on which a switching contact piece (1, 2) of an electrical switching device is arranged.