EP0567727B1 - Actuator - Google Patents

Actuator Download PDF

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Publication number
EP0567727B1
EP0567727B1 EP93101175A EP93101175A EP0567727B1 EP 0567727 B1 EP0567727 B1 EP 0567727B1 EP 93101175 A EP93101175 A EP 93101175A EP 93101175 A EP93101175 A EP 93101175A EP 0567727 B1 EP0567727 B1 EP 0567727B1
Authority
EP
European Patent Office
Prior art keywords
piston
cylinder
housing
displacing
radially
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP93101175A
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German (de)
French (fr)
Other versions
EP0567727A1 (en
Inventor
Kurt Dipl.-Ing. Stoll
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Festo SE and Co KG
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Festo SE and Co KG
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Publication date
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Publication of EP0567727A1 publication Critical patent/EP0567727A1/en
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Anticipated expiration legal-status Critical
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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/06—Servomotor systems without provision for follow-up action; Circuits therefor involving features specific to the use of a compressible medium, e.g. air, steam
    • F15B11/072—Combined pneumatic-hydraulic systems
    • F15B11/076—Combined pneumatic-hydraulic systems with pneumatic drive or displacement and speed control or stopping by hydraulic braking
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
    • F15B15/08—Characterised by the construction of the motor unit
    • F15B15/084—Characterised by the construction of the motor unit the motor being of the rodless piston type, e.g. with cable, belt or chain
    • F15B15/086—Characterised by the construction of the motor unit the motor being of the rodless piston type, e.g. with cable, belt or chain with magnetic coupling
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/405—Flow control characterised by the type of flow control means or valve
    • F15B2211/40515—Flow control characterised by the type of flow control means or valve with variable throttles or orifices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/415—Flow control characterised by the connections of the flow control means in the circuit
    • F15B2211/41527—Flow control characterised by the connections of the flow control means in the circuit being connected to an output member and a directional control valve
    • F15B2211/41536—Flow control characterised by the connections of the flow control means in the circuit being connected to an output member and a directional control valve being connected to multiple ports of an output member
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/455—Control of flow in the feed line, i.e. meter-in control
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/46—Control of flow in the return line, i.e. meter-out control
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
    • F15B2211/705—Output members, e.g. hydraulic motors or cylinders or control therefor characterised by the type of output members or actuators
    • F15B2211/7051—Linear output members
    • F15B2211/7055—Linear output members having more than two chambers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/80—Other types of control related to particular problems or conditions
    • F15B2211/885—Control specific to the type of fluid, e.g. specific to magnetorheological fluid
    • F15B2211/8855—Compressible fluids, e.g. specific to pneumatics

Definitions

  • the invention relates to a piston-cylinder arrangement, having a pneumatic working cylinder which has a cylinder housing, an actuating piston arranged axially movably therein and an output part coupled to it, which is used for connection to a load to be moved outside the cylinder housing, with a radially adjacent to the Working cylinder arranged and in particular designed as an oil brake cylinder hydraulic fluid brake cylinder, which has a displacement piston, which is axially movably arranged in a brake housing and acts on a hydraulic fluid to be displaced there, and with a driving device, via which the actuating piston of the working cylinder is synchronously motionally coupled to the displacement piston of the fluid brake cylinder , wherein the driver device acts in the radial direction through the peripheral wall of the cylinder housing between the actuating piston and the displacement piston by acting as a magnet device device is formed, via which the actuating piston is magnetically coupled to the displacement piston in a contactless manner and which has arranged on the two pistons, radially opposite first and second driving
  • the linear drive described there is used to transport a load, ie any object, whereby the feed of compressed air is generated, which is introduced into the cylinder housing to act on the actuating piston.
  • the load to be moved can be attached to an output part, which is formed here by a slide running on the cylinder housing.
  • the fluid brake cylinder has no self-function in terms of work performance. Its task is to ensure that the feed speed is maintained at a constant rate and / or to slow down the movement of the actuating piston.
  • the displacement piston is located in a displacement space which is part of a closed fluid path equipped with one or more throttle valves.
  • the entraining device coupling the two pistons comprises entraining magnet arrangements arranged on the two pistons, which are arranged radially next to one another, so that sections of these entraining magnet arrangements oppose one another, which attract one another. In this way, there is a contactless, practically rigid connection which, when the actuating piston is displaced, results in a synchronous, ie rectified, movement of the displacement piston.
  • the known piston-cylinder arrangement can often not be used due to lack of space.
  • the known arrangement also appears to be unsuitable for long stroke lengths, since the braking force of the fluid brake cylinder acting laterally on the driven part can lead to transverse loads on the driven part, which favors wear between the driven part and the associated cylinder housing. Furthermore, the problem may arise that if the braking force and / or the driving force are too high, the magnetic connection breaks off and the function of the piston-cylinder arrangement is impaired.
  • the cylinder housing and the brake housing form a coaxial structural unit, the piston arranged in the outer housing being an annular piston and the second driving magnet arrangement arranged on this annular piston and the first driving magnet arrangement arranged on the other piston radially outside coaxially encloses.
  • BE-A-804 905 already shows a piston-cylinder arrangement with actuating pistons and displacement pistons arranged coaxially to one another.
  • the driving device is designed as a rigid mechanical device. It comprises two guide rods which are firmly connected to the displacement piston and which are rigidly connected via a yoke to the piston rod forming the driven part. This has the disadvantage that a relatively wide handling space must also be kept free in the area in front of the arrangement in order to enable an undisturbed movement of the connecting yoke.
  • both entraining magnet arrangements have a ring shape when viewed in cross section and form a sleeve-like structure.
  • the displacement piston can be arranged without a seal in the displacement space, so that, as in the case of labyrinth seals, the small gap between the displacement piston and Displacement space sets a sealing effect sufficient for the present purposes.
  • the piston-cylinder arrangement according to the example combines a pneumatic working cylinder 1 and a hydraulic fluid brake cylinder 2 to form a compact, uniformly manageable structural unit.
  • the working cylinder 1 has a cylinder housing 3 which delimits a cylinder space 4. It is composed of an axially extending peripheral wall 5 and two end walls 6, 7.
  • the peripheral wall 5 practically forms a cylinder tube which is closed by cylinder covers formed by the end walls 6, 7.
  • the peripheral wall 5 is of hollow cylindrical design and has a circular cross-sectional contour both radially on the inside and radially on the outside.
  • an actuating piston 12 is arranged to be movable back and forth in the direction of the longitudinal axis 8 of the arrangement. In the exemplary embodiment, it divides the cylinder space 4 into two axially successive working spaces 13, 14. In the area of its outer circumference, it expediently carries at least one sealing and / or guiding device 15, which cooperates with the inner surface of the peripheral wall 5.
  • An output part 17 designed as a piston rod 16 in the exemplary embodiment is attached to the actuating piston 12, extends in the longitudinal direction 8 and is guided outwards through one (7) of the end walls of the cylinder housing 3.
  • the section of the piston rod 16 lying outside the cylinder housing 3 has a fastening device 18 by means of which a load to be moved, that is to say a workpiece or another object, can in particular be detachably fixed.
  • the associated end wall 7 expediently has a guide and / or sealing arrangement 22 for the piston rod 16.
  • the working cylinder 1 of the exemplary embodiment is double-acting, which is why a connection opening 23, 23 ′ formed on the housing side opens into both working spaces 13, 14, via which a supply and / or discharge of compressed air is possible. Corresponding compressed air lines have been omitted in the drawing for the sake of simplicity.
  • the actuating piston 12 can thus be moved back and forth with its driven part 17 in the direction of the longitudinal axis 8 according to the double arrow 24.
  • the piston-cylinder arrangement according to the invention has the aforementioned hydraulic fluid brake cylinder 2, which is connected in parallel with the working cylinder 1.
  • Its working medium is, for example, oil, so that one can speak of an oil brake cylinder here.
  • It has a brake housing 25 which, in the exemplary embodiment, is placed coaxially around the cylinder housing 3 of the working cylinder 1 in a space-saving manner in a coaxial arrangement.
  • the coaxial arrangement can be seen particularly well in FIG. 2.
  • the brake housing 25 delimits a displacement space 26 with an annular cross section, which thus has an overall essentially hollow cylindrical shape and coaxially encloses the cylinder space 4 radially on the outside.
  • the circumferential wall 5 of the cylinder housing 3 in the exemplary embodiment also represents the inner hollow cylindrical circumferential wall 27 of the brake housing 25, which is located radially spaced on the outside from an outer circumferential wall 28 in a coaxial arrangement.
  • Their inner surface is preferably circularly contoured, as is the outer surface, which in an exemplary embodiment not shown can also be rectangularly contoured, so that the arrangement represents a block of blocks towards the outside.
  • Two end walls 32, 33 are provided for the end closure of the displacement space 26.
  • a respective one of these end walls 32, 33 is formed in one piece with the associated end wall 6, 7 of the cylinder housing 3, so that the number of components is reduced.
  • a displacement piston 34 which can also be referred to as a brake piston, is arranged in the displacement space 26 and can likewise be moved back and forth in the direction of the longitudinal axis 8 according to the double arrow 24. It is equipped with an annular cross-section in accordance with the cross-sectional shape of the displacement space 26 and forms an annular piston, the axial length of which in the exemplary embodiment corresponds at least substantially to the axial length of the actuating piston 12. It is designed without a piston rod and therefore has no mechanical connection to the surroundings.
  • the displacement chamber 26 receiving the displacement piston 34 is completely filled with a hydraulic fluid, here: with oil.
  • the two partial chambers 35, 36 of the displacement space 26, which are separated from one another by the displacement piston 34, are also connected to one another via at least one fluid channel 37.
  • the latter opens in the exemplary embodiment in the region of the two end walls 32, 33 through an opening 31, 31 'into the respectively assigned subchamber 35, 36. In this way, there is a closed fluid path between the two partial chambers 35, 36.
  • a throttle point is built into this, in particular in the form of a throttle valve 38, the throttling intensity preferably being adjustable.
  • the throttle valve 38 is switched on according to FIG. 1 in the fluid channel 37, which runs radially externally next to the outer peripheral wall 28. It can of course also be integrated in this outer circumferential wall 28 or elsewhere in the brake housing 25 or the cylinder housing 3.
  • the actuating piston 12 and the displacement piston 34 are coupled in motion in the axial direction 8 via a driving device 39. Each axial movement of the actuating piston 12 also executes the displacement piston 34 at the same time.
  • the driving device 39 acts in the radial direction with respect to the longitudinal axis 8 through the circumferential side Wall 5 through directly between the two pistons 12,26. During normal use of the arrangement, the two pistons 12, 34 thus represent a practically rigid unit in the axial direction 8.
  • the displacement piston 34 displaces hydraulic fluid from the partial chamber assigned in the direction of movement, which is returned via the fluid channel 37 to the other partial chamber, throttling taking place in the throttle valve 38.
  • the desired speed can be influenced by adjusting the throttle valve 38. Since in the exemplary embodiment the throttling effect is present in both directions of movement of the displacement piston 34, the corresponding braking effect also occurs in both directions of movement of the actuating piston 12. It would of course also be possible to provide a throttle check valve instead of the simple throttle valve 38, so that throttling takes place only in one direction and the return stroke can be carried out unthrottled at maximum speed.
  • the driving device 39 is designed as a magnetic device 40 in the exemplary embodiment. In this way, a mechanical connection between the two pistons 12, 34 is unnecessary. In addition to the simplified structure achieved in this way and the problem-free assembly, tightness problems are also avoided in this way, since the wall 5 lying radially between the two pistons 12, 34 can be designed to be closed over the entire circumference.
  • the two pistons 12, 34 are magnetically connected to one another without contact.
  • the magnet device 40 has a first driving magnet arrangement 41 arranged on the actuating piston 12 and a second driving magnet arrangement 42 arranged radially on the outside and coaxially opposite the displacement piston 34.
  • the configuration is such that the two entraining magnet arrangements 41, 42 attract each other, so that the magnetic coupling can only be torn off when the opposed axial load of the two pistons 12, 34, which normally does not occur during operation. This also prevents mechanical damage to the entire arrangement, even in the event of accidental overloading.
  • the outer second entrainment magnet arrangement extends in the exemplary embodiment over the entire ring circumference of the displacement space 26, seen in cross section, has an annular shape and is embedded in the displacement piston 34 from the radial inside. In this way, it comes to lie very close to the peripheral wall 5 towards the actuating piston 12.
  • Its driving magnet arrangement 41 is embedded in the radially outer circumferential surface, likewise runs along the entire circumference of the associated cylinder space 4 and consequently also preferably has an annular shape in cross section. Since it is also arranged in the immediate radial vicinity of the peripheral wall 5, the radial distance between the two entraining magnet arrangements 41, 42 is very small, which ensures a high magnetic connecting force even with a small size.
  • the two entrainment magnet arrangements 41, 42 each represent a sleeve-like hollow cylindrical structure. They are each constructed in several parts and consist of a plurality of individual ring magnets 43, 44 arranged axially in succession. Between axially adjacent ring magnets of a respective driving magnet arrangement 41, 42 there is expediently also an annular disk 45 made of, in particular, magnetizable material such as steel.
  • the ring magnets 43, 44 are all preferably axially polarized, being within a respective driving magnet arrangement 41,42 the alignment is made so that the poles of the same name axially successive ring magnets 43 and 44 face each other.
  • the number of ring magnets 43, 44 is the same in both entraining magnet devices 41, 42, so that ring magnets 43, 44 are radially opposite each other in pairs. It is expediently provided that the orientation of the ring magnets 43, 44 in the two driving magnet arrangements 41, 42 is opposite, so that poles of the ring magnets 43, 44 of the two driving magnet arrangements 41, 42 opposite one another in the radial direction lie opposite one another. It has been shown that such an arrangement delivers high magnetic forces with a compact design.
  • a further reduction in wear is achieved if the displacement piston 34 in the displacement space without a seal 26 runs.
  • no special sealing elements such as sealing rings are provided. It does not interfere with the effectiveness of the arrangement if a certain amount of fluid flows through the radial running gaps 46 between the displacement piston 34 and the walls 5, 28 flanking it radially during operation. Apart from this, a state similar to that in the case of labyrinth seals expediently arises in the area of this running gap 46, so that the flow is negligible.
  • the magnet device 40 and the two entraining magnet arrangements 41, 42 are of such a permanent magnetic type, the ring magnets 43, 44 of permanent magnet rings are formed. The entire arrangement enables long strokes. For a strong braking effect, 2 viscous oil can be used in the fluid brake cylinder.

Description

Die Erfindung betrifft eine Kolben-Zylinder-Anordnung, mit einem pneumatischen Arbeitszylinder, der ein Zylindergehäuse, einen darin axial beweglich angeordneten Betätigungskolben und ein mit diesem gekoppeltes, zur Verbindung mit einer zu bewegenden Last außerhalb dem Zylindergehäuse dienendes Abtriebsteil aufweist, mit einem radial neben dem Arbeitszylinder angeordneten und insbesondere als Ölbremszylinder ausgeführten hydraulischen Fluidbremszylinder, der einen Verdrängungskolben aufweist, der axial beweglich in einem Bremsgehäuse angeordnet ist und dort ein zu verdrängendes Hydraulikfluid beaufschlagt, und mit einer Mitnahmeeinrichtung, über die der Betätigungskolben des Arbeitszylinders mit dem Verdrängungskolben des Fluidbremszylinders synchron bewegungsgekoppelt ist, wobei die Mitnahmeeinrichtung in Radialrichtung durch die umfangsseitige Wand des Zylindergehäuses hindurch zwischen dem Betätigungskolben und dem Verdrängungskolben wirkt, indem sie als Magneteinrichtung ausgebildet ist, über die der Betätigungskolben berührungslos magnetisch mit dem Verdrängungskolben gekoppelt ist und die an den beiden Kolben angeordnete, einander radial gegenüberliegende erste und zweite Mitnahme-Magnetanordnungen aufweist.The invention relates to a piston-cylinder arrangement, having a pneumatic working cylinder which has a cylinder housing, an actuating piston arranged axially movably therein and an output part coupled to it, which is used for connection to a load to be moved outside the cylinder housing, with a radially adjacent to the Working cylinder arranged and in particular designed as an oil brake cylinder hydraulic fluid brake cylinder, which has a displacement piston, which is axially movably arranged in a brake housing and acts on a hydraulic fluid to be displaced there, and with a driving device, via which the actuating piston of the working cylinder is synchronously motionally coupled to the displacement piston of the fluid brake cylinder , wherein the driver device acts in the radial direction through the peripheral wall of the cylinder housing between the actuating piston and the displacement piston by acting as a magnet device device is formed, via which the actuating piston is magnetically coupled to the displacement piston in a contactless manner and which has arranged on the two pistons, radially opposite first and second driving magnet arrangements.

Eine Anordnung dieser Art geht aus der DE-A-37 19 814 hervor. Der dort beschriebene Linearantrieb wird zum Transport einer Last, d.h. eines beliebigen Gegenstandes, eingesetzt, wobei der Vorschub von Druckluft erzeugt wird, die in das Zylindergehäuse zur Beaufschlagung des Betätigungskolbens eingeleitet wird. Die zu bewegende Last kann an einem Abtriebsteil befestigt werden, das hier von einem auf dem Zylindergehäuse laufenden Schlitten gebildet ist. Der Fluidbremszylinder hat im Sinne einer Arbeitsleistung keine Eigenfunktion. Seine Aufgabe ist es, die Einhaltung einer gleichmäßigen Vorschubgeschwindigkeit zu gewährleisten und/oder die Bewegung des Betätigungskolbens abzubremsen. Der Verdrängungskolben befindet sich in einem Verdrängungsraum, der Bestandteil einer geschlossenen, mit einem oder mehreren Drosselventilen ausgestatteten Fluidstrecke ist. Beim Bewegen des Betätigungskolbens wird der Verdrängungskolben mitbewegt und dadurch Hydraulikfluid aus dem Verdrängungsraum ausgeschoben. Über die Einstellung der Drosselventile kann der dem Verdrängungskolben entgegengesetzte fluidische Widerstand und damit letztlich die Geschwindigkeit des Betätigungskolbens reguliert werden. Die die beiden Kolben koppelnde Mitnahmeeinrichtung umfaßt an den beiden Kolben angeordnete Mitnahme-Magnetanordnungen, die radial nebeneinanderliegend angeordnet sind, so daß sich Abschnitte dieser Mitnahme-Magnetanordnungen gegenüberliegen, die sich gegenseitig anziehen. Auf diese Weise liegt eine berührungslose, praktisch starre Verbindung vor, die beim Verlagern des Betätigungskolbens ein synchrones, d.h. gleichgerichtetes Mitbewegen des Verdrängungskolbens zur Folge hat.An arrangement of this type is apparent from DE-A-37 19 814. The linear drive described there is used to transport a load, ie any object, whereby the feed of compressed air is generated, which is introduced into the cylinder housing to act on the actuating piston. The load to be moved can be attached to an output part, which is formed here by a slide running on the cylinder housing. The fluid brake cylinder has no self-function in terms of work performance. Its task is to ensure that the feed speed is maintained at a constant rate and / or to slow down the movement of the actuating piston. The displacement piston is located in a displacement space which is part of a closed fluid path equipped with one or more throttle valves. When the actuating piston is moved, the displacement piston is also moved and hydraulic fluid is thereby pushed out of the displacement space. The fluidic resistance opposite the displacement piston and thus ultimately the speed of the actuating piston can be regulated by adjusting the throttle valves. The entraining device coupling the two pistons comprises entraining magnet arrangements arranged on the two pistons, which are arranged radially next to one another, so that sections of these entraining magnet arrangements oppose one another, which attract one another. In this way, there is a contactless, practically rigid connection which, when the actuating piston is displaced, results in a synchronous, ie rectified, movement of the displacement piston.

Die bekannte Kolben-Zylinder-Anordnung läßt sich wegen Platzmangels häufig nicht einsetzen. Auch scheint die bekannte Anordnung für große Hublängen wenig geeignet, da die seitlich am Abtriebsteil angreifende Bremskraft des Fluidbremszylinders zu Querbelastungen des Abtriebsteils führen kann, was den Verschleiß zwischen dem Abtriebsteil und dem zugeordneten Zylindergehäuse begünstigt. Ferner kann das Problem auftreten, daß bei zu hoher Bremskraft und/oder zu hoher Antriebskraft die magnetische Verbindung abreißt und die Funktion der Kolben-Zylinder-Anordnung beeinträchtigt ist.The known piston-cylinder arrangement can often not be used due to lack of space. The known arrangement also appears to be unsuitable for long stroke lengths, since the braking force of the fluid brake cylinder acting laterally on the driven part can lead to transverse loads on the driven part, which favors wear between the driven part and the associated cylinder housing. Furthermore, the problem may arise that if the braking force and / or the driving force are too high, the magnetic connection breaks off and the function of the piston-cylinder arrangement is impaired.

Es ist die Aufgabe der vorliegenden Erfindung, eine Kolben-Zylinder-Anordnung der eingangs genannten Art zu schaffen, die bei kompakter Bauweise und hoher Verbindungskraft auch bei großen Hublängen verschleißarm arbeitet.It is the object of the present invention to create a piston-cylinder arrangement of the type mentioned at the outset which, with a compact design and high connecting force, works with little wear, even with large stroke lengths.

Diese Aufgabe wird dadurch gelöst, daß das Zylindergehäuse und das Bremsgehäuse eine koaxiale Baueinheit bilden, wobei der im außen liegenden Gehäuse angeordnete Kolben ein Ringkolben ist und die an diesem Ringkolben angeordnete zweite Mitnahme-Magnetanordnung die am anderen Kolben angeordnete erste Mitnahme-Magnetanordnung radial außerhalb koaxial umschließt.This object is achieved in that the cylinder housing and the brake housing form a coaxial structural unit, the piston arranged in the outer housing being an annular piston and the second driving magnet arrangement arranged on this annular piston and the first driving magnet arrangement arranged on the other piston radially outside coaxially encloses.

Auf diese Weise ergibt sich eine äußerst kompakte Anordnung, bei der die Kraftübertragung zwischen dem Betätigungskolben und dem Verdrängungskolben über den Umfang gesehen gleichförmig ist, so daß sich die im Betrieb auftretenden Seiten- und/oder Kippkräfte gegenseitig ausgleichen. Die Mitnahmekopplung findet im Bereich innerhalb der axialen Baulänge des Zylindergehäuses statt und überschreitet diese auch bei großen Hublängen des Arbeitszylinders nicht. Auch bei großem Hub treten kaum Querkräfte oder Kippmomente auf, so daß ein verschleißarmer Betrieb möglich ist. Indem sich die Mitnahme-Magnetanordnungen koaxial umschließen, kann auch bei geringer Baugröße eine hohe magnetische Verbindungskraft gewährleistet werden.This results in an extremely compact arrangement in which the power transmission between the actuating piston and the displacement piston is uniform over the circumference, so that the lateral and / or tilting forces occurring during operation compensate each other. The coupling takes place in the area within the axial length of the cylinder housing and This does not exceed even with long stroke lengths of the working cylinder. Even with a large stroke, there are hardly any lateral forces or tilting moments, so that low-wear operation is possible. By coaxially enclosing the entraining magnet arrangements, a high magnetic connecting force can be ensured even with a small size.

Eine Kolben-Zylinder-Anordnung mit koaxial zueinander angeordneten Betätigungskolben und Verdrängungskolben zeigt zwar schon die BE-A-804 905. Um dort eine synchrone Bewegungskopplung zwischen den beiden Kolben zu erzielen, ist die Mitnahmeeinrichtung als starre mechanische Einrichtung ausgebildet. Sie umfaßt zwei mit dem Verdrängungskolben fest verbundene Führungsstangen, die über ein Joch starr mit der das Abtriebsteil bildenden Kolbenstange verbunden sind. Dies hat den Nachteil, daß auch im Bereich vor der Anordnung ein relativ breiter Handhabungsraum freigehalten werden muß, um eine ungestörte Bewegung des verbindenden Joches zu ermöglichen.BE-A-804 905 already shows a piston-cylinder arrangement with actuating pistons and displacement pistons arranged coaxially to one another. In order to achieve a synchronous motion coupling between the two pistons there, the driving device is designed as a rigid mechanical device. It comprises two guide rods which are firmly connected to the displacement piston and which are rigidly connected via a yoke to the piston rod forming the driven part. This has the disadvantage that a relatively wide handling space must also be kept free in the area in front of the arrangement in order to enable an undisturbed movement of the connecting yoke.

Vorteilhafte Weiterbildungen der Erfindung sind in den Unteransprüchen aufgeführt.Advantageous developments of the invention are listed in the subclaims.

Bei einer vorteilhaften Weiterbildung ist vorgesehen, daß beide Mitnahme-Magnetanordnungen im Querschnitt gesehen Ringgestalt haben und eine hülsenartige Struktur bilden.In an advantageous development, it is provided that both entraining magnet arrangements have a ring shape when viewed in cross section and form a sleeve-like structure.

Der Verdrängungskolben kann dichtungslos im Verdrängungsraum angeordnet sein, so daß sich wie bei Labyrinthdichtungen allein durch den geringen Laufspalt zwischen Verdrängungskolben und Verdrängungsraum ein für die vorliegenden Zwecke ausreichender Dichteffekt einstellt.The displacement piston can be arranged without a seal in the displacement space, so that, as in the case of labyrinth seals, the small gap between the displacement piston and Displacement space sets a sealing effect sufficient for the present purposes.

Nachfolgend wird die Erfindung anhand der beiliegenden Zeichnung näher erläutert. In dieser zeigen:

Figur 1
eine bevorzugte Bauform der erfindungsgemäßen Kolben-Zylinder-Anordnung in schematischer Darstellung im Längsschnitt und
Fig. 2
einen Querschnitt durch die Anordnung aus Fig. 1 entlang Schnittlinie II-II.
The invention is explained in more detail below with reference to the accompanying drawing. In this show:
Figure 1
a preferred design of the piston-cylinder arrangement according to the invention in a schematic representation in longitudinal section and
Fig. 2
a cross section through the arrangement of FIG. 1 along section line II-II.

Die beispielsgemäße Kolben-Zylinder-Anordnung vereinigt einen pneumatischen Arbeitszylinder 1 und einen hydraulischen Fluidbremszylinder 2 zu einer kompakten, einheitlich handhabbaren Baueinheit.The piston-cylinder arrangement according to the example combines a pneumatic working cylinder 1 and a hydraulic fluid brake cylinder 2 to form a compact, uniformly manageable structural unit.

Beginnend mit dem Arbeitszylinder 1 verfügt dieser über ein Zylindergehäuse 3, das einen Zylinderraum 4 begrenzt. Es setzt sich aus einer sich axial erstreckenden umfangsseitigen Wand 5 und zwei stirnseitigen Wänden 6,7 zusammen. Die umfangsseitige Wand 5 bildet praktisch ein Zylinderrohr, das durch von den stirnseitigen Wänden 6,7 gebildete Zylinderdeckel verschlossen ist. Beim Ausführungsbeispiel ist die umfangsseitige Wand 5 hohlzylindrisch gestaltet und verfügt sowohl radial innen als auch radial außen über eine kreisförmige Querschnittskontur.Starting with the working cylinder 1, it has a cylinder housing 3 which delimits a cylinder space 4. It is composed of an axially extending peripheral wall 5 and two end walls 6, 7. The peripheral wall 5 practically forms a cylinder tube which is closed by cylinder covers formed by the end walls 6, 7. In the exemplary embodiment, the peripheral wall 5 is of hollow cylindrical design and has a circular cross-sectional contour both radially on the inside and radially on the outside.

Im Zylinderraum 4 ist in Richtung der Längsachse 8 der Anordnung hin und her bewegbar ein Betätigungskolben 12 angeordnet. Er unterteilt beim Ausführungsbeispiel den Zylinderraum 4 in zwei axial aufeinanderfolgende Arbeitsräume 13,14. Im Bereich seines Außenumfanges trägt er zweckmäßigerweise mindestens eine Dichtungs- und/oder Führungseinrichtung 15, die mit der Innenfläche der umfangsseitigen Wand 5 zusammenarbeitet.In the cylinder space 4, an actuating piston 12 is arranged to be movable back and forth in the direction of the longitudinal axis 8 of the arrangement. In the exemplary embodiment, it divides the cylinder space 4 into two axially successive working spaces 13, 14. In the area of its outer circumference, it expediently carries at least one sealing and / or guiding device 15, which cooperates with the inner surface of the peripheral wall 5.

Ein beim Ausführungsbeispiel als Kolbenstange 16 ausgebildetes Abtriebsteil 17 ist am Betätigungskolben 12 angebracht, erstreckt sich in Längsrichtung 8 und ist durch eine (7) der stirnseitigen Wände des Zylindergehäuses 3 nach außen geführt. Es ist prinzipiell möglich, die Kolbenstange 16 zusätzlich auch an der entgegengesetzten stirnseitigen Wand 6 herauszuführen, wenn zwei Kraftabgriffsmöglichkeiten geboten werden sollen. Der außerhalb des Zylindergehäuses 3 liegende Abschnitt der Kolbenstange 16 verfügt über eine Befestigungseinrichtung 18, über die eine zu bewegende Last, das heißt ein Werkstück oder ein sonstiger Gegenstand, insbesondere lösbar festlegbar ist.An output part 17 designed as a piston rod 16 in the exemplary embodiment is attached to the actuating piston 12, extends in the longitudinal direction 8 and is guided outwards through one (7) of the end walls of the cylinder housing 3. In principle, it is also possible to additionally lead out the piston rod 16 on the opposite end wall 6 if two force tapping options are to be offered. The section of the piston rod 16 lying outside the cylinder housing 3 has a fastening device 18 by means of which a load to be moved, that is to say a workpiece or another object, can in particular be detachably fixed.

Im Durchdringungsberich der Kolbenstange 16 wartet die zugeordnete stirnseitige Wand 7 zweckmäßigerweise mit einer Führungs- und/oder Dichtungsanordnung 22 für die Kolbenstange 16 auf.In the penetration area of the piston rod 16, the associated end wall 7 expediently has a guide and / or sealing arrangement 22 for the piston rod 16.

Der Arbeitszylinder 1 des Ausführungsbeispiels ist doppeltwirkender Art, weshalb in beide Arbeitsräume 13,14 jeweils eine gehäuseseitig ausgebildete Anschlußöffnung 23,23' einmündet, über die eine Zufuhr und/oder Abfuhr von Druckluft möglich ist. Entsprechende Druckluftleitungen sind in der Zeichnung der Einfachheit halber weggelassen worden. Somit kann der Betätigungskolben 12 mit seinem Abtriebsteil 17 in Richtung der Längsachse 8 gemäß Doppelpfeil 24 hin und her bewegt werden.The working cylinder 1 of the exemplary embodiment is double-acting, which is why a connection opening 23, 23 ′ formed on the housing side opens into both working spaces 13, 14, via which a supply and / or discharge of compressed air is possible. Corresponding compressed air lines have been omitted in the drawing for the sake of simplicity. The actuating piston 12 can thus be moved back and forth with its driven part 17 in the direction of the longitudinal axis 8 according to the double arrow 24.

Vor allem wenn sehr geringe Kolbengeschwindigkeiten zu realisieren sind, bereiten Pneumatikzylinder ab und an Probleme bei der Einhaltung konstanter Geschwindigkeiten. Es besteht überdies die Gefahr des Eintretens des sogenannten stick-slip-Effektes, infolge dessen sich der Kolben ruckartig fortbewegt. Zur Ausschaltung dieser Probleme verfügt die erfindungsgemäße Kolben-Zylinder-Anordnung über den bereits erwähnten, dem Arbeitszylinder 1 parallelgeschalteten hydraulischen Fluidbremszylinder 2. Sein Arbeitsmedium ist beispielsgemäß Öl, so daß man hier von einem Ölbremszylinder sprechen kann. Er verfügt über ein Bremsgehäuse 25, das beim Ausführungsbeispiel in platzsparender Weise in koaxialer Anordnung um das Zylindergehäuse 3 des Arbeitszylinders 1 koaxial herumgelegt ist. Man erkennt die Koaxialanordnung besonders gut in Fig. 2. Das Bremsgehäuse 25 begrenzt einen im Querschnitt ringförmigen Verdrängungsraum 26, der somit eine insgesamt im wesentlichen hohlzylindrische Gestalt hat und den Zylinderraum 4 radial außen koaxial umschließt. Man könnte den Verdrängungsraum 26 als Ringraum bezeichnen.Especially when very low piston speeds can be achieved, pneumatic cylinders occasionally cause problems in maintaining constant speeds. There is also the risk of occurrence of the so-called stick-slip effect, as a result of which the piston moves jerkily. To eliminate these problems, the piston-cylinder arrangement according to the invention has the aforementioned hydraulic fluid brake cylinder 2, which is connected in parallel with the working cylinder 1. Its working medium is, for example, oil, so that one can speak of an oil brake cylinder here. It has a brake housing 25 which, in the exemplary embodiment, is placed coaxially around the cylinder housing 3 of the working cylinder 1 in a space-saving manner in a coaxial arrangement. The coaxial arrangement can be seen particularly well in FIG. 2. The brake housing 25 delimits a displacement space 26 with an annular cross section, which thus has an overall essentially hollow cylindrical shape and coaxially encloses the cylinder space 4 radially on the outside. One could call the displacement space 26 an annular space.

Zugunsten einer materialsparenden Bauweise stellt beim Ausführungsbeispiel die umfangsseitige Wand 5 des Zylindergehäuses 3 zugleich die innere hohlzylindrische Umfangswand 27 des Bremsgehäuses 25 dar, der radial beabstandet außen eine äußere Umfangswand 28 in koaxialer Anordnung gegenüberliegt. Deren Innenfläche ist bevorzugt kreisförmig konturiert, wie im übrigen auch die Außenfläche, die bei einem nicht dargestellten Ausführungsbeispiel aber auch rechteckig konturiert sein kann, so daß die Anordnung nach außen hin einen Quaderblock repräsentiert.In favor of a material-saving design, the circumferential wall 5 of the cylinder housing 3 in the exemplary embodiment also represents the inner hollow cylindrical circumferential wall 27 of the brake housing 25, which is located radially spaced on the outside from an outer circumferential wall 28 in a coaxial arrangement. Their inner surface is preferably circularly contoured, as is the outer surface, which in an exemplary embodiment not shown can also be rectangularly contoured, so that the arrangement represents a block of blocks towards the outside.

Zum stirnseitigen Abschluß des Verdrängungsraumes 26 sind zwei Abschlußwände 32,33 vorgesehen. Eine jeweilige dieser Abschlußwände 32,33 ist beim Ausführungsbeispiel einstückig mit der zugeordneten stirnseitigen Wand 6,7 des Zylindergehäuses 3 ausgebildet, so daß die Anzahl der Bauteile reduziert wird. Es liegen praktisch zwei Gehäusedeckel vor, die einen gleichzeitigen Abschluß der Stirnseiten beider Gehäuse 3,25 ermöglichen.Two end walls 32, 33 are provided for the end closure of the displacement space 26. In the exemplary embodiment, a respective one of these end walls 32, 33 is formed in one piece with the associated end wall 6, 7 of the cylinder housing 3, so that the number of components is reduced. There are practically two housing covers, which enable a simultaneous termination of the front sides of both housings 3.25.

In dem Verdrängungsraum 26 ist ein auch als Bremskolben bezeichenbarer Verdrängungskolben 34 angeordnet, der ebenfalls in Richtung der Längsachse 8 gemäß Doppelpfeil 24 hin und her bewegbar ist. Er ist entsprechend der Querschnittsgestalt des Verdrängungsraumes 26 mit ringförmigem Querschnitt ausgestattet und bildet einen Ringkolben, dessen axiale Länge beim Ausführungsbeispiel zumindest im wesentlichen der axialen Länge des Betätigungskolbens 12 entspricht. Er ist kolbenstangenlos ausgebildet und verfügt demzufolge über keinerlei mechanische Verbindung zur Umgebung hin.A displacement piston 34, which can also be referred to as a brake piston, is arranged in the displacement space 26 and can likewise be moved back and forth in the direction of the longitudinal axis 8 according to the double arrow 24. It is equipped with an annular cross-section in accordance with the cross-sectional shape of the displacement space 26 and forms an annular piston, the axial length of which in the exemplary embodiment corresponds at least substantially to the axial length of the actuating piston 12. It is designed without a piston rod and therefore has no mechanical connection to the surroundings.

Der den Verdrängungskolben 34 aufnehmende Verdrängungsraum 26 ist vollständig mit einem hydraulischen Fluid, hier: mit Öl, gefüllt. Die beiden durch den Verdrängungskolben 34 voneinander abgeteilten Teilkammern 35,36 des Verdrängungsraumes 26 stehen überdies über mindestens einen Fluidkanal 37 miteinander in Verbindung. Letzterer mündet beim Ausführungsbeispiel im Bereich der beiden Abschlußwände 32,33 über eine Öffnung 31,31' in die jeweils zugeordnete Teilkammer 35,36 ein. Auf diese Weise liegt zwischen den beiden Teilkammern 35,36 eine geschlossene Fluidstrecke vor. In diese ist beim Ausführungsbeispiel eine Drosselstelle insbesondere in Gestalt eines Drosselventils 38 eingebaut, wobei sich die Drosselungsintensität vorzugsweise veränderlich einstellen läßt. Das Drosselventil 38 ist gemäß Fig. 1 in den Fluidkanal 37 eingeschaltet, der extern radial neben der äußeren Umfangswand 28 verläuft. Er kann natürlich auch in diese äußere Umfangswand 28 oder an anderer Stelle in das Bremsgehäuse 25 oder das Zylindergehäuse 3 integriert sein.The displacement chamber 26 receiving the displacement piston 34 is completely filled with a hydraulic fluid, here: with oil. The two partial chambers 35, 36 of the displacement space 26, which are separated from one another by the displacement piston 34, are also connected to one another via at least one fluid channel 37. The latter opens in the exemplary embodiment in the region of the two end walls 32, 33 through an opening 31, 31 'into the respectively assigned subchamber 35, 36. In this way, there is a closed fluid path between the two partial chambers 35, 36. In the exemplary embodiment, a throttle point is built into this, in particular in the form of a throttle valve 38, the throttling intensity preferably being adjustable. The throttle valve 38 is switched on according to FIG. 1 in the fluid channel 37, which runs radially externally next to the outer peripheral wall 28. It can of course also be integrated in this outer circumferential wall 28 or elsewhere in the brake housing 25 or the cylinder housing 3.

Über eine Mitnahmeeinrichtung 39 sind der Betätigungskolben 12 und der Verdrängungskolben 34 in axialer Richtung 8 bewegungsgekoppelt. Jede Axialbewegung des Betätigungskolbens 12 führt gleichzeitig auch der Verdrängungskolben 34 aus. Dabei wirkt die Mitnahmeeinrichtung 39 in Radialrichtung bezüglich der Längsachse 8 durch die umfangsseitige Wand 5 hindurch unmittelbar zwischen den beiden Kolben 12,26. Während des üblichen Gebrauches der Anordnung stellen somit die beiden Kolben 12,34 eine in Axialrichtung 8 praktisch starre Einheit dar.The actuating piston 12 and the displacement piston 34 are coupled in motion in the axial direction 8 via a driving device 39. Each axial movement of the actuating piston 12 also executes the displacement piston 34 at the same time. The driving device 39 acts in the radial direction with respect to the longitudinal axis 8 through the circumferential side Wall 5 through directly between the two pistons 12,26. During normal use of the arrangement, the two pistons 12, 34 thus represent a practically rigid unit in the axial direction 8.

Wird im Betrieb der Betätigungskolben 12 durch Druckbeaufschlagung in Axialrichtung verlagert, so wird der Verdrängungskolben 34 synchron mitbewegt. Hierbei verdrängt der Verdrängungskolben 34 aus der in Bewegungsrichtung zugeordneten Teilkammer hydraulisches Fluid, das über den Fluidkanal 37 in die andere Teilkammer zurückgeführt wird, wobei im Drosselventil 38 eine Drosselung stattfindet. Dies hat zur Folge, daß der Verdrängungskolben 34 gegen einen konstanten Druck bewegt werden muß, was insgesamt dazu führt, daß der Betätigungskolben 12 und das mit diesem verbundene Abtriebsteil 17 auch bei sehr niedrigen Geschwindigkeiten mit gleichförmiger Bewegung verlagert werden. Über die Einstellung des Drosselventils 38 läßt sich dabei auf die gewünschte Geschwindigkeit Einfluß nehmen. Da beim Ausführungsbeispiel die Drosselwirkung bei beiden Bewegungsrichtungen des Verdrängungskolbens 34 vorliegt, stellt sich auch bei beiden Bewegungsrichtungen des Betätigungskolbens 12 die entsprechende Bremswirkung ein. Es wäre natürlich auch möglich, anstelle des einfachen Drosselventils 38 ein Drosselrückschlagventil vorzusehen, so daß eine Drosselung lediglich in einer Richtung erfolgt und der Rückhub ungedrosselt mit maximaler Geschwindigkeit vorgenommen werden kann.If, during operation, the actuating piston 12 is displaced in the axial direction by pressurization, the displacement piston 34 is moved synchronously. Here, the displacement piston 34 displaces hydraulic fluid from the partial chamber assigned in the direction of movement, which is returned via the fluid channel 37 to the other partial chamber, throttling taking place in the throttle valve 38. This has the consequence that the displacement piston 34 has to be moved against a constant pressure, which overall leads to the actuating piston 12 and the driven part 17 connected to it being displaced with uniform movement even at very low speeds. The desired speed can be influenced by adjusting the throttle valve 38. Since in the exemplary embodiment the throttling effect is present in both directions of movement of the displacement piston 34, the corresponding braking effect also occurs in both directions of movement of the actuating piston 12. It would of course also be possible to provide a throttle check valve instead of the simple throttle valve 38, so that throttling takes place only in one direction and the return stroke can be carried out unthrottled at maximum speed.

Die Mitnahmeeinrichtung 39 ist beim Ausführungsbeispiel als Magneteinrichtung 40 ausgebildet. Auf diese Weise erübrigt sich eine mechanische Verbindung zwischen den beiden Kolben 12,34. Abgesehen von dem so erzielten vereinfachten Aufbau und der problemlosen Montage vermeidet man auf diese Weise auch Dichtheitsprobleme, da die radial zwischen den beiden Kolben 12,34 liegende Wand 5 über den gesamten Umfang geschlossen ausgebildet sein kann.The driving device 39 is designed as a magnetic device 40 in the exemplary embodiment. In this way, a mechanical connection between the two pistons 12, 34 is unnecessary. In addition to the simplified structure achieved in this way and the problem-free assembly, tightness problems are also avoided in this way, since the wall 5 lying radially between the two pistons 12, 34 can be designed to be closed over the entire circumference.

Über die Magneteinrichtung 40 sind die beiden Kolben 12,34 berührungslos magnetisch fest miteinander verbunden. Beispielsgemäß ist vorgesehen, daß die Magneteinrichtung 40 eine am Betätigungskolben 12 angeordnete erste Mitnahme-Magnetanordnung 41 und eine dieser koaxial radial außen gegenüberliegende, am Verdrängungskolben 34 angeordnete zweite Mitnahme-Magnetanordnung 42 aufweist. Die Ausgestaltung ist so getroffen, daß sich die beiden Mitnahme-Magnetanordnungen 41,42 gegenseitig anziehen, so daß erst bei einer im Betrieb normalerweise nicht auftretenden entgegengesetzt gerichteten Axialbelastung der beiden Kolben 12,34 ein Abreißen der magnetischen Kopplung auftreten kann. Dies verhindert im übrigen auch bei versehentlicher Überbelastung eine mechanische Beschädigung der gesamten Anordnung.Via the magnet device 40, the two pistons 12, 34 are magnetically connected to one another without contact. According to the example, it is provided that the magnet device 40 has a first driving magnet arrangement 41 arranged on the actuating piston 12 and a second driving magnet arrangement 42 arranged radially on the outside and coaxially opposite the displacement piston 34. The configuration is such that the two entraining magnet arrangements 41, 42 attract each other, so that the magnetic coupling can only be torn off when the opposed axial load of the two pistons 12, 34, which normally does not occur during operation. This also prevents mechanical damage to the entire arrangement, even in the event of accidental overloading.

Die äußere Zweite Mitnahme-Magnetanordnung erstreckt sich beim Ausführungsbeispiel über den gesamten Ringumfang des Verdrängungsraumes 26, besitzt im Querschnitt gesehen eine Ringgestalt und ist von der radialen Innenseite her in den Verdrängungskolben 34 eingelassen. Auf diese Weise kommt sie sehr nahe an der umfangsseitigen Wand 5 zum Betätigungskolben 12 hin zu liegen. Dessen Mitnahme-Magnetanordnung 41 ist in die radial außen liegende Umfangsfläche eingelassen, verläuft ebenfalls entlang des gesamten Umfanges des Zugeordneten Zylinderraumes 4 und hat demzufolge im Querschnitt ebenfalls bevorzugt eine Ringgestalt. Da sie ebenfalls in unmittelbarer radialer Nähe zur umfangsseitigen Wand 5 angeordnet ist, ist der radiale Abstand zwischen den beiden Mitnahme-Magnetanordnungen 41,42 sehr gering, was auch bei geringer Baugröße eine hohe magnetische Verbindungskraft gewährleistet.The outer second entrainment magnet arrangement extends in the exemplary embodiment over the entire ring circumference of the displacement space 26, seen in cross section, has an annular shape and is embedded in the displacement piston 34 from the radial inside. In this way, it comes to lie very close to the peripheral wall 5 towards the actuating piston 12. Its driving magnet arrangement 41 is embedded in the radially outer circumferential surface, likewise runs along the entire circumference of the associated cylinder space 4 and consequently also preferably has an annular shape in cross section. Since it is also arranged in the immediate radial vicinity of the peripheral wall 5, the radial distance between the two entraining magnet arrangements 41, 42 is very small, which ensures a high magnetic connecting force even with a small size.

Beim Ausführungsbeispiel stellen die beiden Mitnahme-Magnetanordnungen 41,42 jeweils eine hülsenartige hohlzylindrische Struktur dar. Sie sind jeweils mehrteilig aufgebaut und bestehen aus einer Mehrzahl axial aufeinanderfolgend angeordneter einzelner Ringmagnete 43,44. Zwischen axial benachbarten Ringmagneten einer jeweiligen Mitnahme-Magnetanordnung 41,42 befindet sich zweckmäßigerweise noch eine Ringscheibe 45 aus insbesondere magnetisierbarem Material wie Stahl. Die Ringmagnete 43,44 sind alle vorzugsweise axial polarisiert, wobei innerhalb einer jeweiligen Mitnahme-Magnetanordnung 41,42 die Ausrichtung so getroffen ist, daß gleichnamige Pole axial aufeinanderfolgender Ringmagnete 43 bzw. 44 einander Zugewandt sind. Die Anzahl der Ringmagnete 43,44 ist in beiden Mitnahme-Magneteinrichtungen 41,42 gleich, so daß sich Ringmagnete 43,44 jeweils paarweise radial gegenüberliegen. Dabei ist zweckmäßigerweise vorgesehen, daß die Ausrichtung der Ringmagnete 43,44 in den beiden Mitnahme-Magnetanordnungen 41,42 entgegengesetzt ist, so daß sich in Radialrichtung ungleichnamige Pole der Ringmagnete 43,44 der beiden Mitnahme-Magnetanordnungen 41,42 gegenüberliegen. Es hat sich gezeigt, daß eine derartige Anordnung bei kompakter Bauweise hohe Magnetkräfte liefert.In the exemplary embodiment, the two entrainment magnet arrangements 41, 42 each represent a sleeve-like hollow cylindrical structure. They are each constructed in several parts and consist of a plurality of individual ring magnets 43, 44 arranged axially in succession. Between axially adjacent ring magnets of a respective driving magnet arrangement 41, 42 there is expediently also an annular disk 45 made of, in particular, magnetizable material such as steel. The ring magnets 43, 44 are all preferably axially polarized, being within a respective driving magnet arrangement 41,42 the alignment is made so that the poles of the same name axially successive ring magnets 43 and 44 face each other. The number of ring magnets 43, 44 is the same in both entraining magnet devices 41, 42, so that ring magnets 43, 44 are radially opposite each other in pairs. It is expediently provided that the orientation of the ring magnets 43, 44 in the two driving magnet arrangements 41, 42 is opposite, so that poles of the ring magnets 43, 44 of the two driving magnet arrangements 41, 42 opposite one another in the radial direction lie opposite one another. It has been shown that such an arrangement delivers high magnetic forces with a compact design.

Bei der beispielsgemäßen Anordnung erfolgt über den gesamten Umfang des Betätigungskolbens 12 eine gleichmäßige Kraftübertragung auf den Verdrängungskolben 34, so daß weder der Betätigungskolben 12 noch das Abtriebsteil 17 von nennenswerten Kippmomenten beaufschlagt werden. Die Kontaktbereiche zwischen Betätigungskolben 12 und umfangsseitiger Wand 5 sowie zwischen Abtriebsteil 17 und Führungs- und/oder Dichtungsanordnung 22 bleiben auf diese Weise vor nennenswertem Verschleiß verschont.In the arrangement according to the example, uniform force transmission to the displacement piston 34 takes place over the entire circumference of the actuating piston 12, so that neither the actuating piston 12 nor the driven part 17 are subjected to significant tilting moments. The contact areas between the actuating piston 12 and the peripheral wall 5 and between the driven part 17 and the guide and / or sealing arrangement 22 are thus spared significant wear.

Eine weitere Verschleißminderung ergibt sich, wenn der Verdrängungskolben 34 dichtungslos im Verdrängungsraum 26 läuft. In diesem Falle sind keine speziellen Dichtelemente wie Dichtringe vorgesehen. Es stört die Wirksamkeit der Anordnung nicht, wenn die radialen Laufspalte 46 zwischen dem Verdrängungskolben 34 und den ihn radial flankierenden Wänden 5,28 im Betrieb von einer gewissen Fluidmenge durchströmt werden. Abgesehen davon stellt sich im Bereich dieser Laufspalte 46 zweckmäßigerweise ein Zustand ähnlich dem bei Labyrinthdichtungen ein, so daß die Durchströmung vernachlässigbar ist.A further reduction in wear is achieved if the displacement piston 34 in the displacement space without a seal 26 runs. In this case, no special sealing elements such as sealing rings are provided. It does not interfere with the effectiveness of the arrangement if a certain amount of fluid flows through the radial running gaps 46 between the displacement piston 34 and the walls 5, 28 flanking it radially during operation. Apart from this, a state similar to that in the case of labyrinth seals expediently arises in the area of this running gap 46, so that the flow is negligible.

Bei einem kolbenstangenlos ausgebildeten Verdrängungskolben 34 besteht zum einen der Vorteil, daß zwischen dem Verdrängungsraum 26 und der Umgebung keine dynamisch beanspruchten Dichtungen erforderlich sind, im Bereich derer im Laufe der Zeit verschleißbedingt Öl austreten könnte. Zum anderen ergeben sich beidseits des Verdrängungskolbens 34 in den beiden Teilkammern 35,36 identische Kammerquerschnitte, so daß im Rahmen der Fluidverdrängung zwischen den beiden Teilkammern 35,36 keine Volumen-Ausgleichsmaßnahmen zu treffen sind. Dies vereinfacht den Aufbau beträchtlich.In the case of a displacement piston 34 designed without a rod, there is on the one hand the advantage that no dynamically stressed seals are required between the displacement space 26 and the surroundings, in the area of which oil could escape due to wear over time. On the other hand, identical chamber cross sections result on both sides of the displacement piston 34 in the two subchambers 35, 36, so that no volume compensation measures need to be taken as part of the fluid displacement between the two subchambers 35, 36. This considerably simplifies the construction.

Abschließend sei noch darauf hingewiesen, daß es sich bei der Magneteinrichtung 40 und den beiden Mitnahme-Magnetanordnungen 41,42 um solche permanentmagnetischer Art handelt, wobei die Ringmagnete 43,44 von Permanentmagnetringen gebildet sind. Die gesamte Anordnung ermöglicht lange Hübe. Für eine starke Bremswirkung kann im Fluidbremszylinder 2 zähes Öl verwendet werden.Finally, it should also be pointed out that the magnet device 40 and the two entraining magnet arrangements 41, 42 are of such a permanent magnetic type, the ring magnets 43, 44 of permanent magnet rings are formed. The entire arrangement enables long strokes. For a strong braking effect, 2 viscous oil can be used in the fluid brake cylinder.

Claims (7)

  1. Piston-cylinder assembly , with a pneumatic operating cylinder (1), having a cylinder housing (3), an actuating piston (12) mounted so as to be axially moveable within this housing, and coupled to the piston an output member (17) connecting with a load to be moved outside the cylinder housing (3), with mounted radially next to the operating cylinder (1) an hydraulic fluid brake cylinder (2) in particular in the form of an oil dashpot, with a displacing piston (34), mounted so as to be axially moveable in a brake housing (25) and acting there upon a hydraulic fluid to be displaced, and with a driving device (39) via which the actuating piston (12) of the fluid brake cylinder (2) is synchronously motion-coupled to the displacing piston (34) of the fluid brake cylinder, wherein the driving device (39) acts radially through the peripheral wall (5) of the cylinder housing (3) between the actuating piston (12) and the displacing piston (34), in that it is designed as a magnetic device (40), through which the actuating piston (12) is magnetically coupled without contact to the displacing piston (34), and which has radially-opposite first and second driving magnet assemblies located on the two pistons (12, 34), characterized in that the cylinder housing (3) and the brake housing (25) form a coaxial basic unit, wherein the piston (34) mounted in the outer housing (25) is an annular piston, and the second driving magnet assembly (42) mounted on this annular piston coaxially encloses and is radially outside the first driving magnet assembly (41) mounted on the other piston (12).
  2. Piston-cylinder assembly according to claim 1, characterized in that both driving magnet assemblies (41, 42), viewed in cross-section, have an annular shape and form a sleeve-shaped structure.
  3. Piston-cylinder assembly according to claim 1 or 2, characterized in that the peripheral wall (5) of the cylinder housing (93) simultaneously forms the inner hollow-cylindrical peripheral wall (27) of the brake housing (25).
  4. Piston-cylinder assembly according to any of claims 1 to 3, characterized in that the displacing piston (34) is annular in form and is mounted in a displacement space (26) which is annular in shape and coaxially surrounds and is radially external to the cylinder space (4) accommodating the actuating piston (12).
  5. Piston-cylinder assembly according to claim 4, characterized in that the displacing piston (34) is mounted in the displacement space (26) without seals.
  6. Piston-cylinder assembly according to any of claims 1 to 5, characterized in that the displacing piston (34) is designed as a rodless piston.
  7. Piston-cylinder assembly according to any of claims 1 to 6, characterized in that the output member (17) is formed by a piston rod (16) guided out from the cylinder housing (3) at one or more of its end faces.
EP93101175A 1992-04-30 1993-01-27 Actuator Expired - Lifetime EP0567727B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4214575A DE4214575A1 (en) 1992-04-30 1992-04-30 PISTON CYLINDER ARRANGEMENT
DE4214575 1992-04-30

Publications (2)

Publication Number Publication Date
EP0567727A1 EP0567727A1 (en) 1993-11-03
EP0567727B1 true EP0567727B1 (en) 1995-12-06

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EP93101175A Expired - Lifetime EP0567727B1 (en) 1992-04-30 1993-01-27 Actuator

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DE (2) DE4214575A1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102004024499A1 (en) * 2004-05-18 2005-12-15 Rexroth Mecman Gmbh Pneumatic transportation mechanism for moving items, has case formed of single pipe extending up to at least two planes from end to end

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE804905A (en) * 1973-09-17 1974-01-16 Vlemings Karel AIR CYLINDER WITH HYDRAULIC BRAKE
DE3719814A1 (en) * 1987-06-13 1988-12-22 Ingbuero Ramcke Gmbh Hydropneumatic linear drive

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DE59301072D1 (en) 1996-01-18
EP0567727A1 (en) 1993-11-03

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