EP2497959B1 - Fluid-actuated rotary drive - Google Patents

Abstract

The fluid-operated rotary drive device has a stator body (2) and a driving body that is rotated relative to a stator about a rotational axis (4). A rigid coupling bar (48) is extended between the two movable end sections (33) of the bellows. The rigid bar is connected with a movable side of an end section by a hinge unit (51) and is also connected with another movable side of end section by another spaced hinge unit (52).

Description

The invention relates to a fluid-operated rotary drive device comprising a stator body and a driven body rotatable relative to the stator about a rotational axis, further comprising a rotatably connected to the driven body and pivotable about the axis of rotation drive arm, and with two each having an arcuate longitudinal extension bellows, with each other facing concave longitudinal sides are arranged side by side, wherein they each have a stator fixed to the stationary end portion and a related, spaced from the axis of rotation to the drive arm motion-coupled movable end portion, wherein the two bellows are at least partially variable in length by controlled internal Fluidbeaufschlagung to their with movable end portions exert a pivoting force on the drive arm.

One from the DE 10149395 A1 known rotary drive device of this type comprises two circular arc-shaped bellows, which are fixed at one end fixed to a stator and the other end to a pivotable drive arm. The drive arm is rotatably connected to a pivot axis which forms a force tap for tapping a rotary movement and thus acts as a driven body. By controlled fluid loading of the interiors of the two bellows of the drive arm can be driven to pivotal movement be to produce a desired rotational movement of the output body. During such a process, an opposing extension and shortening of the two bellows takes place, wherein the arranged on the drive arm end portions of the bellows, which can be referred to as movable end portions directly join the pivotal movement of the drive arm.

A certain inadequacy of this known rotary drive device is that the bellows must have a high elasticity in order to deform in accordance with the desired pivotal movement of the drive arm can. With a high elasticity of the bellows, the problem of a radial expansion is connected when the rotary drive device is operated with high fluid pressures. This can lead to non-linear pivoting movements of the drive arm and, accordingly, impair the output side rotational movement. To counteract the problem, the pleat wall of the bellows can be supported radially by support means. However, this has a relatively complex and expensive construction of the rotary drive device result.

From the DE 43 12 503 A1 goes out a bellows, which is made in one piece from plastic or rubber. A fold-like structured wall of the bellows is integrally connected end to end with a fastening component.

In the DE 43 28 522 A1 a swing-wing drive is described which has a rotor disposed in a stator housing, which is provided with a radially projecting wing. Between the stator housing and the rotor two arcuate bellows are arranged, which are supported on the one hand stationary on the stator housing and on the other hand on the wing. By alternating fluid loading of the two bellows, the rotor can be driven to a rotary motion. The driving force is in each case introduced by the bellows directly into the wing of the rotor.

A similarly constructed drive device is from the US 3,977,648 known. There is also the possibility to equip a rotor with a plurality of radially projecting wings, so that it can be acted upon by a larger number of bellows at the same time. The individual bellows can be structured in one piece.

From the DE 10 2006 022 855 A1 It is already known to produce the gripping body of a mechanically operating gripper device in one piece by a generative manufacturing process.

The invention has for its object to provide a fluid-operated rotary drive device of the type mentioned, which favors the production of uniform rotational movements at low cost and long life.

To achieve this object, the invention provides that extends between the two movable end portions of the bellows, a rigid coupling web, which is articulated via a first hinge means with a movable end portion and a spaced therefrom second hinge means with the other movable end portion, and that the drive arm is pivotally connected to the coupling web at a radial distance from the axis of rotation via a third hinge means spaced from the first and second hinge means, each hinge means defines a hinge axis parallel to the axis of rotation.

In this way, the two bellows act with their movable end portions not directly, but indirectly with the interposition of a connecting coupling web drivingly together with the drive arm. The coupling web is pivotable relative to the movable end portion of each bellows and at the same time relative to the drive arm, which is ensured by the hinge devices. An associated advantage is that the length variation of the bellows with respect to the pivoting movement of the drive arm is decoupled in a certain way, so that no relevant tension can occur. Even if the structure of the bellows has no particularly high elasticity and thus the deformation capacity of the bellows is limited, can be achieved by the hinge structure relatively large tilt angle of the drive arm. With the help of the joint structure can be realized if necessary, an advantageous motion translation. If the bellows structurally rather stiff, this has the advantage that they do not tend to radial expansion even at high internal pressure, so that uniform rotational movements can be generated without complex support measures.

Due to its advantageous structure, the rotary drive device also allows a precise rotational positioning of the output body and, if necessary, an exact regulation of the force acting on the drive arm pivoting force and thus the tappable on the output body torque. Incidentally, can be generated with the rotary drive device according to the invention with a small size and low weight, a comparatively high output torque.

Advantageous developments of the invention will become apparent from the dependent claims.

The two bellows are expediently rigidly fastened to the stator body with their stationary end sections. Such an attachment can be particularly easily realized by the bellows, for example, integrally formed on the stator body.

The stator body expediently engages with a holding section between the two stationary end sections of the bellows. In this way, there is the advantageous possibility to arrange the two stationary end portions on opposite sides of the holding portion and in close proximity to each other. The holding portion can be used advantageously to form therein a fluid channel system, by means of which the bellows are controlled in the interior can be acted upon with pressure medium to activate them as needed.

Preferably, each bellows has a fold-like structured and therefore denoted as a fold wall peripheral wall. This is expediently attached to the holding portion of the stator body with simultaneous sealing in one piece.

It is expedient if each bellows has a peripheral fold wall whose fold depth is greater in the region of the convex longitudinal side opposite the respective adjacent bellows than in the area of the concave longitudinal side. The fold depth in the area of the concave longitudinal side can even be zero. In particular, each bellows may have a peripheral fold wall which is structured such that it is unfolded in the region of its concave longitudinal side and thereby bendable, but at the same time length-invariant. With such a structure, the length variation of each bellows evoked by controlled fluid loading manifests itself in an elongation or shortening, especially in the area of the convex longitudinal side, while the pleat wall is progressively less or not changed in length as the wall areas are closer to the concave longitudinal side ,

The axis of rotation of the driven body expediently extends between the two bellows, in particular at the same distance from both bellows, if one bases on the non-fluid-loaded initial state of the bellows. The two bellows can in particular be arranged such that they each extend in a piece-wide arcuate manner about the axis of rotation of the output body.

Output body and drive arm are preferably formed integrally with each other. The output body may be formed, for example, disk, plate or plate-shaped.

The output body is suitable as a carrier for any component to be positioned by means of a reciprocating rotary movement. Such a component may be, for example, a gripping device for releasably gripping objects. Incidentally, there is also the possibility of forming the driven body directly as part of a component to be moved rotationally, for example as a base body of a gripping device, on which at least one pivotable gripping element is arranged.

In a particularly simple embodiment of the rotary drive device, the articulation axes of all three articulation devices are each stationary transversely to their axial direction with respect to the two arranged by a respective hinge means hinged components. The articulated by a joint device components are therefore supported radially with respect to each other with respect to the associated hinge axis against each other, so that between the hinged components only a pivoting movement is possible.

In particular, for generating relatively large output rotational angle of the driven body, it has proved to be advantageous if the exclusively possible relative pivoting mobility relates only to the articulated via the first joint means and the second joint means to each other components. In contrast, it is provided with respect to the third articulation device that its articulation axis is movable transversely to an imaginary connecting straight line in a plane perpendicular to the axis of rotation of the output body, which plane extends between the articulation axes of the first and second articulation device. In particular, it is provided in this case that the hinge axis of the third hinge device is movable relative to the drive arm in respect of the axis of rotation of the driven body radial direction.

In this way, the coupling web is mounted on the drive arm such that it is pivotable relative to the drive arm on the one hand, but on the other hand can also be moved translationally relative to the drive arm. In this way, Verklemmungstendenzen is counteracted between the coupling web and the drive arm.

Such a bearing can be realized in an advantageous manner by virtue of the fact that a bearing pin defining the axis of rotation is formed on the coupling web and is rotatable and at the same time engages axially displaceable in a formed on the drive arm slot.

A particularly advantageous construction of the bellows each provides a pleat wall whose structural rigidity is selected such that radial expansion is prevented during the internal pressure action occurring during operation, even without additional external support structures, and only length changes can take place at least partially.

Expediently, at least one separate fluid control channel opens into the interior space of each bellows, so that an independent internal fluid admission of the two bellows is possible. The two bellows can thus, for example, alternately ventilated in opposite directions and vented to generate a reciprocating rotary motion of the output body. The bellows are in particular arranged so that each of them can actively bring about a rotational movement of 45 ° of the output body and at the same time allows a rotational movement in the opposite direction by the same angular range. In particular, in this way it is possible to let the bellows work against each other to control the system stiffness and / or the tappable torque can.

Due to the inherent resilience of the pleated wall of each bellows, in principle, an operation is possible in that at the same time always only one bellows is actuated. In order to shift the driven body, starting from a starting position in one direction of rotation, only one of the bellows is actively acted upon with pressure medium in this case. The return to the starting position is done by a pressure relief of this bellows due to its inherent elasticity. Deviating from this, however, the Return to the starting position also with the support of the other bellows by synchronizing the bleeding process of one bellows with a simultaneous ventilation process of the other bellows.

The terms vent and aeration are used at this point regardless of whether a gaseous or a liquid pressure medium is used as the drive medium for the bellows. Particularly advantageous is the rotary drive device for operation with compressed air.

Conveniently, it is ensured solely by the structure of each bellows that the controlled internal pressure application has an arcuate and in particular arcuate length variation of the bellows result. In this way, an additional external forced guidance of the bellows is unnecessary.

If necessary, the rotary drive device can be equipped with a position detection device in order to be able to detect one or more rotational positions of the output drive body. The position detection device can also be designed as a displacement measuring system. In this case, in particular a refinement is recommended as a film potentiometer.

The rotary drive device can be produced in a particularly cost-effective manner using a generative production method. The additive manufacturing can refer to all or even only a few components of the rotary drive device. Preferably, at least one structural unit containing the stator body and the two bellows is produced in one piece by using a generative manufacturing method.

Among various known methods of generative production is especially the so-called selective laser sintering for producing the rotary drive device. Selective laser sintering is a process in which spatial structures are produced by sintering from a powdery starting material. This is a generative layer construction process. The structural unit is built up layer by layer. Due to the effect of the laser beams any three-dimensional geometries can be generated even with complex undercuts. The basis for the manufacturing process are three-dimensional geometric data of the desired structure, which are processed as layer data, for example as CAD data.

Basically, the term "generative manufacturing processes" is often understood as rapid prototyping or rapid manufacturing processes for the rapid and cost-effective production of products. The production takes place directly on the basis of computer-internal data models, in particular of informal powders by means of chemical and / or physical processes. Although these are original methods, no special tools are required for the realization of a specific product, in which the geometry of the product to be produced is implemented.

Appropriately, a plastic material is used as the material for the structural unit generated by generative production, wherein in particular polyamide is recommended.

Using a generative manufacturing process, the rotary drive device also has the advantageous possibility of connecting a plurality of generatively manufactured components to one another by conventional measures. So can For example, joint axes of the joint devices can be realized by subsequently introduced axle bolts.

Incidentally, the joint means can also be constructed in one piece as a whole, for example in the manner of so-called film hinges. Here, the articulated interconnected components are integrally formed with each other, wherein the material thickness is reduced in the region of the hinge means for defining a hinge axis, so that there is the possibility to pivot the mutually articulated components by mutual bending relative to each other.

Figur 1

eine bevorzugte erste Ausführungsform der erfindungsgemäßen Drehantriebsvorrichtung in einer perspektivischen Darstellung,

Figur 2

die Drehantriebsvorrichtung aus Figur 1 in einer Seitenansicht mit Blickrichtung gemäß Pfeil II und teilweise aufgebrochen,

Figur 3

eine Draufsicht der Drehantriebsvorrichtung mit Blickrichtung gemäß Pfeil III aus Figur 2,

Figur 4

eine Unteransicht der Drehantriebsvorrichtung mit Blickrichtung gemäß Pfeil IV aus Figur 2,

Figur 5

einen Querschnitt durch die Drehantriebsvorrichtung, rechtwinkelig zur Drehachse des Abtriebskörpers und gemäß Schnittlinie V-V aus Figur 2,

Figur 6

eine weitere Ausführungsform der Drehantriebsvorrichtung in einer perspektivischen Darstellung,

Figur 7

eine Seitenansicht der Drehantriebsvorrichtung aus Figur 6 mit Blickrichtung gemäß Pfeil VII,

Figur 8

eine Draufsicht der Drehantriebsvorrichtung der Figuren 6 und 7 mit Blickrichtung gemäß Pfeil VIII aus Figur 7,

Figur 9

einen Querschnitt durch die Drehantriebsvorrichtung der Figuren 6 bis 8 gemäß Schnittlinie IX-IX aus Figuren 7 und 10, und

Figur 10

einen nichtlinearen Längsschnitt durch die Drehantriebsvorrichtung der Figuren 6 bis 9 gemäß Schnittlinie X-X aus Figur 8.

The invention will be explained in more detail with reference to the accompanying drawings. In this show:

FIG. 1

A preferred first embodiment of the rotary drive device according to the invention in a perspective view,

FIG. 2

the rotary drive device FIG. 1 in a side view looking in the direction of arrow II and partially broken,

FIG. 3

a plan view of the rotary drive device with viewing direction according to arrow III FIG. 2 .

FIG. 4

a bottom view of the rotary drive device as seen from arrow IV FIG. 2 .

FIG. 5

a cross section through the rotary drive device, perpendicular to the axis of rotation of the driven body and according to section line VV FIG. 2 .

FIG. 6

a further embodiment of the rotary drive device in a perspective view,

FIG. 7

a side view of the rotary drive device FIG. 6 looking in the direction of arrow VII,

FIG. 8

a plan view of the rotary drive device of FIGS. 6 and 7 looking in the direction of arrow VIII FIG. 7 .

FIG. 9

a cross-section through the rotary drive device of FIGS. 6 to 8 according to section line IX-IX FIGS. 7 and 10 , and

FIG. 10

a non-linear longitudinal section through the rotary drive device of FIGS. 6 to 9 according to section line XX FIG. 8 ,

The following statements relate, unless otherwise specified in individual cases, to all embodiments shown in the drawing.

The generally designated by reference numeral 1 rotary drive device is designed for actuation by means of fluid force and can be driven by means of a fluidic and preferably gaseous pressure medium. Preferably, compressed air is provided as drive medium.

The rotary drive device 1 has a stator body 2, which is expediently equipped with at least one attachment interface 3, with the aid of which it can be fastened to an arbitrary support structure (not shown any further). Such a support structure may for example be the movable arm of a handling robot.

The rotary drive device 1 furthermore has a driven body 5 which can be rotated relative to the stator body 2 about an axis of rotation 4. The rotational movement of the driven body 5 illustrated in the drawing by a double arrow is referred to as output rotary motion 6.

The output body 5 can in principle have any desired design. In the embodiment of FIGS. 1 to 5 it is shaped like a dish. Preferably, it has at least one attachment interface 7, represented by way of example by two attachment holes, on which a component to be driven for rotational movement can be fixed in a preferably detachable manner. Such a component is embodied, for example, as a gripping device designed to grip objects.

It is readily possible to carry out the output body 5 as an integral part of a component to be driven in a rotary motion. Such a solution is in the embodiment of FIGS. 6 to 10 realized. There, the output body 5 forms the base body of a fluid-operated gripping device 8, which is also rotated by turning the output body 5 simultaneously. The gripping device 8 has, for example, a plurality of gripping elements 12 pivotably mounted on the output body 5, which can be pivoted by an integrated actuator 13 of the gripping device 8 which can be actuated by fluid force in order to carry out a gripping operation. The actuator 13 is designed as an example as a bellows actuator and can be controlled by a communicating with him and in particular the driven body 5 passing through actuation channel 14 controlled by a fluidic pressure medium.

To generate the output rotary motion 6, a torque can be introduced into the output body 5. This is done with the help of a rotatably connected to the output body 5 drive arm 15 which projects in a transverse to the axis of rotation 4 and in particular perpendicular direction extending from the output body 5. The drive arm 15 has a force introduction section 16 arranged at a radial distance from the rotation axis 4, to which it can be acted upon by a transverse force denominatable as a pivoting force, which runs in a main plane 17 perpendicular to the rotation axis 4 and at the same time is oriented transversely to an imaginary connecting line. which connects the axis of rotation 4 with the force introduction portion 16. Depending on the direction in which a pivoting force is introduced into the force introduction section 16, the drive arm 15 can be driven to a pivoting movement 17 about the axis of rotation 4, which is directed either clockwise or counterclockwise. In particular, it is also possible to drive the drive arm 15 to an oscillating pivoting movement 17.

By the drive arm 15 is rotatably connected to the output body 5, resulting from a pivoting movement 17 of the drive arm 15 directly the rotary output movement 6 of the output body. 5

The drive arm 15 and the driven body 5 are expediently formed integrally with each other, wherein they form in particular a structural unit, which is produced by applying a generative manufacturing process.

In the embodiment of FIGS. 1 to 5 the stator body 2 is provided with two bearing brackets 18a, 18b, between which the drive arm 15 with a force introduction section 16 opposite bearing portion 22 engages, wherein through the bearing plates 18 a, 18 b and the bearing portion 22 a not further illustrated bearing pin is inserted, which defines the axis of rotation 4. The output body 5 is seated on a protruding from the drive arm 15 and in particular angled support arm 21st

In the embodiment of FIGS. 6 to 10 the drive arm 15 has a bearing section 22 opposite the outer force introduction section 16, which is connected to the output body 5 via a sleeve-shaped connection section 23 coaxial with the rotation axis 4, wherein the connection section 23 for defining the rotation axis 4 of at least one of the stator body 2 worn bearing eye 24 is included.

The drive arm 15 expediently has a straight line between the bearing section 22 and the force introduction section 16. It may be formed plate-like, with its main plane of expansion in the embodiment of FIGS. 1 to 5 parallel to the axis of rotation 4 and in the embodiment of FIGS. 6 to 10 perpendicular to the axis of rotation 4 runs.

To generate the force acting on the drive arm 15 pivoting forces and thus for generating the output movement 6, the rotary drive device 1 with two bellows 25, 26 is provided, which are referred to better distinction hereinafter as the first bellows 25 and second bellows 26. Each bellows 25, 26 has an arcuate longitudinal extension and thus an arcuate longitudinal axis 27th

The two bellows 25, 26 are arranged alongside one another in such a way that their longitudinal axes 27 extend in one and the same plane perpendicular to the axis of rotation 4, in particular in the main plane 19.

Each bellows 25, 26 has a concave longitudinal side 28 facing its center of curvature and a convex longitudinal side 29 facing away from the center of curvature. The two bellows 25, 26 are aligned so that their concave longitudinal sides 28 face one another.

Each bellows 25, 26 has two in the axial direction of its longitudinal axis 27 mutually oppositely oriented end portions, one of which is designated as a fixed end portion 32 and the other as a movable end portion 33.

Each bellows 25, 26 has a peripheral wall having a fold structure, which will be referred to below as a fold wall 34. By way of example, the stationary and movable end sections 32, 33 are formed by end sections of the pleated wall 34 of the relevant bellows 25, 26. Each fold wall 34 peripherally surrounds and encloses a bellows interior 35.

Each bellows 25, 26 is preferably fixed rigidly to the stator body 2 with its stationary end section 32.

The stator body 2 expediently has a holding section 36 on which both stationary end sections 32 are fixed. The holding portion 36 engages in particular between the two stationary end portions 32 and has two mutually oppositely oriented end faces 37, to each of which one of the stationary end portions 32 connects. The holding portion 36 is in the same plane as the longitudinal axes 27 of the two bellows 25, 26th

Preferably, the two bellows 25, 26 and their folding walls 34 are integrally connected to each other via the holding portion 36 arranged therebetween. In an advantageous manner, the stator body 12, together with the two bellows 25, 26, can form an integral structural unit, which is produced by using a generative manufacturing method.

The fold walls 34 are attached to the stator body 2 in a fluid-tight manner. Thus, the bellows 25, 26 in the region of the fixed end portions 32 are sealed by the stator 2.

Also in the area of the movable end sections 33, the bellows 25, 26 are closed in a fluid-tight manner. Each bellows 25, 26 has there a closure wall 38, to which the associated fold wall 34 under sealing and preferably in one piece, in particular in the context of a generative manufacturing process, is attached.

In this way, the bellows inner spaces 35 each hermetically sealed by a peripheral fold wall 34, a closure wall 38 and the stator 2 to the environment.

However, each bellows interior 35 can be acted upon controlled by a drive medium. In this case, in particular, an individual, independent fluid admission of the two bellows 25, 26 can be performed. This is made possible by the fact that in each bellows interior 35 one of two fluid control channels 43, 44 opens, which the stator body 2 prevail and open, each with a connection opening to an outer surface 45 of the stator 2. With the interposition of external fluid channels, a control valve device controlling the connection to a pressure source and a pressure sink can be connected to the connection openings, which is in particular able to control the fluid admission of the two bellows internal spaces independently of one another.

The fluid loading of a bellows interior 35 has the consequence that the associated bellows 25 or 26 at least partially undergoes an extension in the axial direction of its longitudinal axis 27. The pleat wall 34 is axially stretched at least partially in such fluid application. Accordingly, the bellows length is reduced when the bellows interior 35 is depressurized again.

The change in length of the bellows 25, 26 manifests itself in a displacement of the movable end portion 33 of the respective bellows 25, 26 according to double arrow 46 in the axial direction of the associated longitudinal axis 27. The movable end portion 33 moves along a curved path, which is due to the particular structure the fold wall 34 is due.

On the one hand, the pleated wall 34 of each bellows 25, 26 has such a structural rigidity that it experiences no radial expansion at the operating pressures of the drive medium occurring in its interior, but only permits changes in length. The changes in length result from a widening and contraction of the folds 47 of the pleated wall 34 that follow one another in the axial direction of the longitudinal axis 27. With an important factor for the change in length along a curved trajectory in the exemplary embodiment, the radially measured fold depth of the folds 47 in the region of the convex longitudinal side 29 is substantially greater than in the region of the concave longitudinal side 28 FIG. 9 illustrated by the second embodiment that the fold depth at the concave longitudinal side 28 is only a fraction of that in the region of the outer convex longitudinal side 29.

In the embodiment of FIGS. 1 to 5 the depth of fold in the area of the concave longitudinal side 28 is even reduced to zero. In the region of the concave longitudinal side 28 there is no folding at all here and the fold wall 28 has there an unfolded, in particular strip-shaped, wall section, which does not allow any elongation at length.

This means that when fluid is applied to a bellows interior 35, the change in length of a bellows 25, 26 increases from the radially inner cross-sectional area to the radially outer cross-sectional area, the term "radial" referring to the center of curvature of the arch structure of the bellows 25, 26 concerned.

In particular, in the embodiment of FIGS. 1 to 5 has a Fluidbeaufschlagung the bellows interior 35 with the result that the pleated wall 34 undergoes no change in length at its inner concave longitudinal side 28, but there is only bent to the extent in which the pleated wall 34 in its radially outer region by unfolding or Lengthwise extension of the pleat wall 34 is extended.

For power transmission between the bellows 25, 26 and the drive arm 15 is the rotary drive device 1 with a the two movable end portions 33 of the bellows 25, 26 connecting rigid coupling web 48 equipped. The coupling web 48, which expediently has a rectilinear extent, is articulated via a first joint 51 on the movable end portion 33 of the first bellows 25. In addition, the coupling web 48 is articulated at a location spaced from the first joint device 51 via a second joint device 52 at the movable end portion 33 of the second bellows 26.

Each of the two hinge devices 51, 52 defines a hinge axis 54, which runs parallel to the axis of rotation 4 of the output body 5, which simultaneously defines a pivot axis of the drive arm 15.

Due to the two hinge devices 51, 52, the coupling web 48 is pivotable on the one hand relative to the movable end section 33 of the first bellows 25 and on the other hand relative to the movable end section 33 of the second bellows 26. As a pivot axis, the respectively associated hinge axis 54 functions.

The drive arm 15 is pivotally connected to the coupling web 48 at its force introduction section 16 and, therefore, at a location radially spaced from the axis of rotation 4, by means of a third articulation device 53. The third articulation device 53 likewise defines a joint axis 54, which runs parallel to the axis of rotation 4 and thus to the articulation axes 54 of the first and second articulation devices 51, 52.

The third articulation device 53 is arranged at a distance from the first and second articulation devices 51, 52, wherein the distance to the first articulation device 51 is, in particular, the same as the distance to the second articulation device 52. Preferably, the third hinge device 53 is located between the first and second hinge devices 51, 52. Due to the third hinge device 53, the coupling web 58 is mounted pivotably relative to the drive arm 15.

The first and second hinge devices 51, 52 are each designed so that between the hinged together components 33, 48 each thrust and tensile forces in relation to the associated hinge axis 34 radial direction are transferable. The first and second articulation device 51, 52 thus defines in each case exclusively a pivoting degree of freedom between the coupling web 48 and the associated movable end section 33.

In both exemplary embodiments, the third articulation device 53 is designed in such a way that the coupling web 48, by means of the associated joint axis 54, can introduce transverse forces into the drive arm 15, which are aligned at right angles to an imaginary connecting straight line which extends between the axis of rotation 4 and the articulation axis 54 of the third Joint device 53 extends. These forces act as pivoting forces, which, taking into account the lever arm defined by the drive arm 15, generate the torque that can be picked up on the output body 5.

If the length of a bellows 25 or 26 is increased by fluid loading of a bellows interior 35, the associated movable end section 33 is displaced, wherein its movement is introduced into the drive arm 15 via the associated first or second articulation device 51, 52 and the third articulation device 53, so that this experiences a swivel force.

Since the two bellows 25, 26 are forcibly coupled via the coupling web 48, they always carry out opposing deflection movements 46 in their longitudinal direction. In other words, therefore, the extension of each bellows a simultaneous shortening of the other bellows result. This results in the advantageous effect that the drive arm 15 at each angular position in each of its two possible pivoting directions can be acted upon by a pivoting force. Thus, the drive arm 15 can always be acted upon actively in both directions. In this case, a simultaneous application in both directions is possible to achieve a stiffening of the system.

All embodiments have in common that the axis of rotation 4, viewed in its axial direction, between the two bellows 25, 26 extends and in particular with at least substantially the same distance from these two bellows 25, 26th

Particularly useful is an arrangement of the axis of rotation 4 in the region of the two stationary end portions 32nd

With regard to the third articulation device 53, there is the possibility of an embodiment in which, as in the case of the first and second articulation devices 51, 52, an all-round radial support between the coupling web 48 and the drive arm 15 with respect to the associated articulation axis 54 is present. Such an embodiment is in the embodiment of FIGS. 1 to 5 realized. Thus, between the coupling web 48 and the drive arm 15 only pivotal movements about the hinge axis 54 of the third hinge device 53 possible.

One has thus in the embodiment of FIGS. 1 to 5 a solution in which the hinge axes 54 of all hinge devices 51, 52, 53 are arranged transversely to their axial direction stationary with respect to each both by a respective hinge means 51, 52, 53 hinged to each other components.

The joint axis 54 of the third joint device 53 is thus supported in particular such that its distance from the axis of rotation 4 is independent of the operating state of the two bellows 25, 26 and in particular independent of the instantaneous pivot position of the drive arm 15 constant.

An alternative design, which exemplifies based FIGS. 6 to 10 is illustrated, allows the hinge axis 54 of the third hinge means 53 a translational movement degree of freedom in a plane perpendicular to the axis of rotation 4 and thereby transversely to an imaginary straight line connecting the hinge axes 54 of the first and second hinge means 51, 52 with each other .. Der.translatorische Bewegungsfreiheitsgrad in particular a linear degree of freedom of movement, wherein the corresponding linear movement in FIG. 9 at 55 is illustrated by a double arrow.

Particularly advantageous is an embodiment in which the hinge axis 54 of the third hinge device 53 relative to the drive arm 15 in respect of the axis of rotation 4 radial direction is linearly movable.

To ensure the described properties, the third articulation device 53 can, for example, be designed in such a way that the drive arm 15 has an elongated hole 56 which ensures the translational degree of freedom of movement, in which a bearing pin 57 fixedly arranged on the coupling web 48 is linear displaceable and - under definition of the hinge axis 54 - at the same time also rotatably received.

In the embodiment of the FIGS. 6 to 10 realized variant of a third joint device 53 promises large swivel angle for the drive arm 15 at already relatively low deflection of the bellows 25, 26. The relative mobility between the two bellows 25, 26 is improved because the drive arm 15 in the radial direction with respect to the axis of rotation 4 no Blocking of the coupling web 48 causes.

For attachment of the first and second hinge devices 51, 52, the two bellows 25, 26 are expediently provided at their movable end sections 33, each with a bearing flange 58, which is in particular formed integrally with the associated closure wall 38. Out FIGS. 1 and 6 is clearly seen that the bearing flange 58 may be fork-shaped, so that the coupling web 48 can engage between two bearing legs of the bearing flange 58.

To realize the first and second hinge means 51, 52 of the coupling web 48 is expediently interspersed at its two opposite end portions of a respective axis of rotation 4 parallel bearing bore, which is aligned with formed in the bearing flange 58 bearing bores, wherein in the mutually aligned bearing bores a joint axis 54 defining bearing pin 61 is inserted. Such a bearing pin 61 can in a comparable manner also for the realization of the third articulation device 53 of the in FIGS. 1 to 5 shown embodiment can be used.

Drive arm 15 and coupling web 48 may for example be arranged so that the drive arm 15 engages on a longitudinal side of the coupling web 48 outside. This is the embodiment of the FIGS. 6 to 10 the case.

At the in FIGS. 1 to 5 In the embodiment shown, the coupling web 48 has a window 62 into which the drive arm 15 is inserted with its force introduction section 16 and in the region of which the bearing pin 57 acting as hinge axis 54 is arranged.

Notwithstanding the embodiments, all hinge devices 51, 52, 53 may also be realized in one piece and in particular using a generative manufacturing process.

If there is an additive manufacturing, in particular the method of selective laser sintering is used.

As a material for the rotary drive device 1, in particular as far as it is generatively manufactured components, in particular a plastic material in question, preferably polyamide.

In order to detect the rotational position or the rotational angle of the output body 5, the rotary drive device 1 can be equipped with a position detection device, in particular with a displacement measuring system. The position detection can be realized in particular by detecting at least one pivot position of the drive arm 15. In FIG. 5 At 63, a receiving hole 63 formed in the drive arm 15 can be seen, in which an actuator of a position detecting device can be fixed.

The rotary drive devices 1 of both embodiments are each equipped with two generatively manufactured bellows 25, 26, which allow expansion of a rotational movement of the output body 5 by up to 90 °. The bellows 25, 26 are arranged so that each bellows 25 or 26 can actively bring about a rotational movement of 45 ° and at the same time allows a rotational movement by 45 ° in the opposite direction. Thus, the bellows 25, 26 also work against each other, so that the torque or the stiffness is adjustable.

For the two bellows 25, 26, a forced operation is unnecessary. The bow-shaped length variation results solely from the special shape of the pleat wall 34 alone.

Especially in this context, it is advantageous if the fold wall 34 has a substantially rectangular cross-section, as for example in the sectional view of FIG. 10 is expressed. The wall sections on the concave longitudinal side 28 and on the convex longitudinal side 29 expediently each have a course parallel to the longitudinal axis 4.

Claims (15)

1. Fluid-actuated rotary actuator device, comprising a stator body (12) and a driven body (5) which is rotatable about an axis of rotation (4) relative to the stator body (12), further comprising a drive arm (15) which is non-rotatably connected to the driven body (5) and pivotable about the axis of rotation (4), and further comprising two bellows (25, 26), each having an arcuate longitudinal dimension, which are arranged one beside the other with their concave longitudinal sides (28) facing one another, wherein each of them comprises a stationary end section (32) secured to the stator body (2) and a movable end section (33) located opposite the former at a distance from the axis of rotation (4) and motion-coupled to the drive arm (15), wherein the two bellows (25, 26) are at least in some regions variable in length by controlled internal fluid application in order to apply a pivoting force to the drive arm (15) with their movable end sections (33), characterised in that a rigid coupling web (48) extends between the two movable end sections (33) of the bellows (25, 26), which web (48) is connected to the one movable end section (33) via a first joint device (51) and to the other movable end section (33) via a second joint device (52) located at a distance therefrom, and in that the drive arm (15) is hinged to the coupling web (48) at a radial distance from the axis of rotation (4) via a third joint device (53) located at a distance from the first and second joint devices (51, 52), each of the joint devices (51, 52, 53) defining a joint axis parallel to the axis of rotation (4).
2. Rotary actuator device according to claim 1, characterised in that the two bellows (25, 26) are rigidly secured to the stator body (2) by their stationary end sections (32).
3. Rotary actuator device according to claim 1 or 2, characterised in that the stator body (2) engages with a retaining section (36) between the two stationary end sections (32) of the bellows (25, 26), in particular in such a way that the two stationary end sections (32) are placed on opposite sides of the retaining section (36), wherein fluid control passages (43, 44) communicating with the bellows interiors (35) of the bellows (25, 26) expediently pass through the retaining section (36).
4. Rotary actuator device according to claim 3, characterised in that each bellows (25, 26) has a peripheral corrugation wall (34) one end of which is integrally secured to the retaining section (36) while forming a seal.
5. Rotary actuator device according to any of claims 1 to 4, characterised in that each bellows (25, 26) has a peripheral corrugation wall (34) which is structured such that the corrugation height is greater in the region of the convex longitudinal side (29) than in the region of the concave longitudinal side (28).
6. Rotary actuator device according to any of claims 1 to 5, characterised in that each bellows (25, 26) has a peripheral corrugation wall (34) which is structured such that it is bendable but variable in length in the region of its concave longitudinal side (28).
7. Rotary actuator device according to any of claims 1 to 6, characterised in that the axis of rotation (4) as viewed in the axial direction of said axis of rotation (4) extends between the two bellows (25, 26), in particular in the proximity of the two stationary end sections (32).
8. Rotary actuator device according to any of claims 1 to 7, characterised in that the driven body (5) and the drive arm (15) are designed as a single piece.
9. Rotary actuator device according to any of claims 1 to 8, characterised in that the joint axes (54) of all joint devices (51, 52, 53) are, at right angles to their axial direction, arranged to be stationary with respect to each pair of components (33, 48, 15) which are hinged to one another by a joint device (51, 52, 53).
10. Rotary actuator device according to any of claims 1 to 9, characterised in that the joint axis (54) of the third joint device (53) is supported in such a way that its distance from the axis of rotation (4) remains constant irrespective of the operating state of the two bellows (25, 26).
11. Rotary actuator device according to any of claims 1 to 8, characterised in that the joint axis (54) of the third joint device (53) is movable in a plane perpendicular to the axis of rotation (4) at right angles to an imaginary straight connecting line which connects the joint axes (54) of the first and second joint devices (51, 52) to one another.
12. Rotary actuator device according to any of claims 1 to 8 or according to claim 11, characterised in that the joint axis (54) of the third joint device (53) is movable relative to the drive arm (15) in a direction which is radial with respect to the axis of rotation (4).
13. Rotary actuator device according to any of claims 1 to 12, characterised in that each of the bellows (25, 26) has a corrugation wall (34), the structural rigidity of which prevents a radial expansion and only allows changes in length at least in some regions.
14. Rotary actuator device according to any of claims 1 to 13, characterised in that at least one dedicated fluid control passage (43, 44) which expediently passes through the stator body (2), in particular in such a way that an independent internal application of fluid to the two bellows (25, 26) is possible, terminates into the bellows interior (35) of each bellows (25, 26).
15. Rotary actuator device according to any of claims 1 to 14, characterised in that at least one structural unit containing the stator body (2) and the two bellows (25, 26) is produced in one piece using a generative manufacturing method, in particular selective laser sintering, the structural unit expediently consisting of polyamide.

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