WO2009018793A2 - Actuator - Google Patents

Abstract

The invention relates to an actuator comprising a shaft drive (1) setting a shaft (2) in rotation, wherein at least one rope (3) can be wound onto or off the shaft, the rope having a rope length and two rope ends, wherein the rope ends (3') can each be connected to a rope attachment support (4, 5). In the region of the rope attachment point a means is provided, by which the rope forces acting along the ropes each engage in tangential points diametrically opposed with respect to a shaft axis of the shaft, in that upon a rotation of the shaft for the purpose of winding the rope onto the shaft both rope ends spaced from the shaft can be moved relative to the shaft toward the shaft at equal speeds, and in that the ropes during winding around the shaft have contact, or have contact in a plurality of layers around the shaft while the axial position to the shaft remains the same and the winding radius increases.

Description

 actuator

Technical area

The invention relates to an actuator with a shaft drive in rotation staggering shaft drive, about whose shaft at least one band or rope-like element, hereinafter referred to rope, up and / or unwindable, which has a rope length and has two cable ends, wherein the cable ends are each connectable to a cable mounting bearing, the cable mounting bearings are relatively diametrically opposed to the shaft, the rope connected to the shaft between two cable mounting bearings takes a taut state and the rope along its rope length in a localized rope area between the two cable ends at a cable attachment point connected to the shaft.

State of the art

Actuators for transmission primarily of tensile forces, for example between a mechanical fixed abutment and a relative to the abutment movably mounted object, are known in manifold variety. A very simple embodiment of such an actuator is connected to a fixed counter bearing, motor-driven shaft around which a traction means, for example in the form of a rope, is wound with appropriate shaft rotation. Is the loose end of the rope, for example, with an otherwise loose stored Object firmly connected, so the object is pulled in the direction of the fixed abutment by the motor-assisted rope rewind. A disadvantage of such an actuator arrangement is the direct load action directly on the shaft, which applies to form suitable stable and / or stable storage. Of course, such actuator systems from the field of mechanical drive technology and with regard to the formation of micromechanical actuator systems in the field of precision mechanics and micromechanics arbitrarily complicated constructed, motor-assisted tensile stresses between corresponding abutment-generating actuators are known to the drive or the locomotion kinematic Serve systems.

Of particular interest for the control of moving mechanisms and their operation in an industrial environment, such as the operation of grippers, levers, flaps, slides, etc. but especially for the realization of movable prostheses for the purpose of replication, for example, a human hand, or for the implementation of any articulated robot kinematics, as used in industrial robotic arms or artificial locomotion mechanisms are so-called muscle-like actuators, which are able to contract under large force generation and only able to generate low restoring forces, so that a corresponding pulling apart of such muscle-like, in the compressed state transferred actuators can be achieved only by external force in the elongated state.

DE 2300104 B2 describes a device with which a chain link fence can be tensioned. For this purpose, a hollow post with radial bores is provided, in which a winding shaft is mounted. Individual wire mesh fence segments are interconnected by means of tension wires, which are guided by the radial holes in the post and by diametrical holes of the winding shaft. The chain link fence can be tensioned by turning the winding shaft manually. The tensioning wire winds on the winding shaft. In contrast to the actuator described below, the winding of the tension wire is completely uncontrolled, so that along the Winding shaft occurring tilting moments can lead to deflections of the winding shaft. This is counteracted by the fact that support disks are provided along the winding shaft and the shaft is mechanically robust with its large diameter compared to the wire. Furthermore, this device is structurally and functionally not suitable for continuous winding and unwinding but only for one-time clamping and occasional retightening.

The actuator described below, which is intended to combine properties, for example with regard to a muscle-like function, combines a mechanically very simple design and action principle, and also has the highest degree of integration capability in mechanically complex systems and, moreover, its size can be scaled almost arbitrarily ,

Such an actuator is described in DE 10 2006 012 431 A1, the disclosure of which is expressly referred to here. The actuator has a shaft drive which sets a shaft in rotation about whose shaft at least one band-shaped or rope-like element can be wound up and / or unwound, which has a length and two element or cable ends. The ribbon or rope-like element has a high tensile strength in the longitudinal direction and transverse elasticity to be wound on waves with the smallest possible radii. Basically suitable for this purpose are commercially available steel cables or steel wire wires, as they are known in the form of strings of stringed instruments from the field of music. Also, whole bundles of fine steel wire fibers can be used in a suitable manner, as used for example as a "leader" in fishing sport.Also made of plastic or nylon ropes, as they are available as a commercial fishing or kite cords are However, higher steel strips can be used instead of commercially available steel wire or plastic cords, by means of which both high tensile forces and also considerable thrust forces are transferable without the multiplicity of The term "rope" is used hereafter for the purpose of simplifying the description of possible embodiments for the formulation "band or rope-like element" chosen in the claim formulation.

The rope is preferably formed in one piece and has a rope length limited by two rope ends. In a not necessarily central, located between the two cable ends, locally limited cable area, the rope is connected to the shaft. The connection of the cable to the shaft is preferably designed in the form of a fixed connection, so that the cable, for example, is fixed selectively along the length thereof to the shaft.

The two cable ends are each connectable to a cable mounting bearing, which are substantially diametrically opposed to the shaft, so that the rope always assumes a tensioned state. The term "cable mounting bearing" is to be understood generally and is intended to describe a force application point at which a force generatable along the cable extension can be transmitted to an arbitrary area connected to the force application point or to any object connected to the force application point either tensile or shear forces transmitted and thus generate depending on the design of the bearing, for example. By attaching to a peripheral edge of a hub torque.

By rotation of the shaft, the rope begins to wind up on the shaft, whereby the cable ends connected to the cable fixing bearings are pulled in the direction of the shaft. If, however, the shaft is rotated by the shaft drive in the opposite direction to the winding direction oriented, so there is a corresponding development of the rope from the shaft. It would also be conceivable to connect two cable pieces with their respective ends to the shaft, as if the cable were formed in one piece as described above. It is also possible to attach more than one rope to a shaft of a shaft drive to the transferable along the cable strands tensile and possibly shear forces in the Sum to increase or rope ends coming from several opposite directions together.

For example, assume that both cable mounting bearing are relatively loose relative to the shaft drive, which is spatially fixed, for example, to a mechanical support structure or a fixed mechanical abutment, the loosely mounted cable mounting bearings each move at the same speed on the shaft.

Likewise, it is possible, the shaft drive including shaft and one of the two mounting bearings relative to the other mounting bearing, which is fixed, for example, to a mechanical counter-bearing or on a suitably shaped support structure, loosely so that when shaft rotation both the shaft drive and shaft as also the loosely guided rope mounting bearing in the case of a rope winding on the shaft to be moved in the direction of the fixed cable mounting bearing.

Regardless of the above-described storage possibilities of the shaft drive relative to the two cable mounting bearings acting through the shaft drive along the shaft on the rope force moment is almost lossless converted into a force acting on the two cable mounting bearing force, and, and this is the particular advantage of Aktorprinzips that along the ropes occurring rope forces F are not absorbed by the shaft of the shaft drive. For this reason, the shaft can have extremely small diameters and even low-power shaft drives are able to generate large rope forces in this way. This is ultimately the reason that the actuator itself can be made small and lightweight and thus ideal for purposes of miniaturization.

Presentation of the invention

The use of the above actuator principle has shown that the essential success of the actuator depends on how evenly the rope or the at least two diametrically opposite cable strands on the shaft and from this be settled again. Thus, force moments acting on the shaft can only be excluded if the cable strands are always brought into contact relative to the shaft axis at two diametrically opposite points of contact. For this purpose, special precautions should be taken, especially in cases where a considerable rope length has already been wound onto the shaft.

According to the solution, therefore, an actuator with the features of the preamble of claim 1 is characterized in that in the region of the cable attachment point, a means is provided by which the rope forces acting along the cables attack each with respect to a shaft axis of the shaft diametrically opposed tangent points that at a Rotation of the shaft for the purpose of winding the rope on the shaft both spaced from the shaft shaft ends are movable relative to the shaft on the shaft at equal speeds, and that the ropes when winding by the means in one layer and in a helical arrangement about the shaft in abutment be brought or multilayer, with constant axial position relative to the shaft with increasing winding radius around the shaft.

The advantage of the actuator according to the invention is to be seen in that provided by the provided in the region of the cable attachment means means that the rope ordered, ie positively guided to form a fixed by the means of the application pattern is guided around the shaft. In addition, to simplify the explanation of the actuator according to the invention, it is assumed that two cable strands are unwound or unwound around the shaft, although it is in principle possible to have more than two cable strands, ie 3, 4 and more cable strands in a correspondingly equivalent manner around the shaft , according to forcibly guided up or unwind. In all cases, the means to be specified in more detail below ensure that the contact points of the cable strands are diametrically opposed along the peripheral edge of the shaft with respect to the shaft axis or are distributed equally at the peripheral edge, so that the tensile forces acting on the shaft via the individual cable strands Compensate largely completely at the location of the shaft, so that the shaft is exposed to no force moments. To facilitate Explanation of the actuator according to the invention will be made in the following to specific embodiments, which are illustrated in the following figures. However, the general inventive concept underlying the actuator should not be limited by the specific embodiments.

Brief description of the invention

The invention will now be described by way of example without limitation of the general inventive idea by means of embodiments with reference to the drawings. Show it:

1 actuator with shaft and cable (general principle explanation),

2a, b show preferred winding methods along the shaft with a) two cable strands and b) four cable strands,

3a-e embodiments for cable attachment to or along a shaft,

Fig. 4 showing a winding device with a longitudinal to

Shaft movably arranged guide ring,

5 embodiment with a doppelhelikalen guide contour along the shaft,

6 embodiment with helical spring-like trained leadership

Backstage,

Fig. 7 showing an orderly winding two cable strands along a shaft in the way spatially guided cable mounting bearing and

Fig. 8a, b actuator representation with fuse for tensioning the cable strands. Ways to carry out the invention, industrial usability

FIG. 1 schematically shows an actuator which is described in DE 10 2006 012 431 A1 and provides a shaft drive 1 consisting of an electric motor, a motor-driven shaft 2 and a cable 3 connected to the shaft 2, wherein the cable 3 has two cable ends 3 ', which are each connected to cable mounting bearings 4, 5. The cable mounting bearings 4, 5 are located diametrically opposite relative to the shaft 2 and constitute fastening points for the cable ends 3 '. The shaft drive 1 designed as an electric motor is controlled via an electronic control unit 6 with respect to the rotational direction and rotational speed of the shaft 2. For fastening and receiving the dead weight of the shaft drive 1, hereinafter referred to as motor, the motor 1 is supported with a corresponding support structure 7.

Due to the spatial arrangement of the relative to the shaft 2 diametrically opposite cable mounting bearings 4, 5, the cable 3 is wound on rotation of the shaft 2 in the manner shown in Figure 1 on the shaft 2. It is important to ensure that the cable 3 always assumes an at least slightly tensioned state between the corresponding cable mounting bearings 4, 5. The output torque M generated with the shaft 2 is in each case converted into a force F acting on the cable mounting bearings 4, 5 virtually loss-free. Due to acting on the shaft 2 respectively from opposite directions and equal forces F shaft 2 remains almost powerless, so that it can be designed with very small diameter and driven by low-power motors, although it is still able to generate high rope forces ,

In the embodiment according to Figure 1, the support structure 7 provides for receiving the dead weight of the motor 1 and the torque M. generated by the shaft rotation and the associated winding process. In order to ensure that the cable 3 with its two cable sections diametrically opposite the shaft 2 is wound as single as possible around the shaft 2 in a manner in which the two cable sections of the cable 3 are always connected to two respective tangential points of the shaft 2 opposite the shaft axis abutment, the cable 3 is fixed by means of a fixing ring 12 firmly fitting to the shaft 2, so that the stretched around the shaft 2 cable sections each have a rope longitudinal extension, with the shaft an angle ß with 90 ° <ß <0 °, preferably 70th ° <β <20 ° (see FIG. 2a, top illustration). In Figure 2a, bottom view, a view in the wavelength direction is shown, based on the diametrically opposite to the shaft 2 contact points P1 and P2 of the cable sections 3 are illustrated. It is obvious that with a sufficiently dimensioned diameter small shaft 2, the force acting on the shaft 2 forces or moments of force cancel each other or are negligible.

According to the embodiment and arrangement with two cable sections for wrapping around the shaft 2, it is also possible according to the embodiment in Figure 2 b to arrange four cable strands in a corresponding arrangement around the shaft 2 and wind up, in which case the longitudinal extents of the individual cable strands relative to the shaft longitudinal axis of the shaft 2 include an angle ß in the order described above. In this way it can be ensured that the cable sections can be brought into contact helically around the shaft 2 in a single-layer sequence. Also in Figure 2b, bottom view, it can be seen that the respective four contact points P1 to P4 contribute in pairs in diametrical comparison to a complete force compensation at the location of the shaft 2.

For the orderly installation of the rope 3 in the single-layer, helical manner shown in Figure 2, it is advantageous to use cables that have a certain dimensional stability, so that when winding a respective aufzuwickelnder cable section along a side edge of an already wound on the shaft 2 piece of rope can slide off self-centering. In principle, it is possible to form the shaft 2 with a smooth shaft surface, however, an embodiment not shown is conceivable in which the shaft 2 provides groove-shaped recesses, which as it were helically rotate around the shaft 2, in which the ropes 3 when winding independently lay down. In the case of an arrangement according to FIG. 2a, the shaft provides two recesses of double helical groove-shaped or concave shape, where, in the case of FIG. 2b, the shaft respectively provides four groove-shaped recess tracks.

In the figures 3a to e different embodiments for a fixation of the rope 3 on the shaft 2 are shown. FIG. 3a, left-hand illustration, illustrates that the cable 3 can not necessarily be fastened to the shaft 2 in a continuous manner but also in a split form. Thus, the loose cable ends 112 of the two cable sections are fixed with a secured by a locking screw 13 mounting ring 12 fixed to the shaft 2, the cable ends 112 are formed thickened advantageously, for example by means of a knot or by melting the rope ends, so that slipping the cable ends 112 can be excluded by the fastening ring 12. Figure 3a right illustration shows an alternative way of fastening the rope 3 longitudinally to the shaft 2 by the rope 3 in the region of the mounting ring 12 around the shaft 2, half wrapped around and pressed firmly against the shaft 2 with the mounting ring 12.

In the embodiment shown in Figure 3c, the shaft 2 has a feedthrough channel 10, through which the cable 3 is threaded. In order to avoid that the cable 3 suffers bruising, in particular in edge regions of the shaft 2 and thus could suffer damage, the edge regions of the feedthrough channel 10 are rounded.

In Figure 3d in conjunction with Figure 3e, a preferred embodiment for attaching the rope 3 at an end face of the shaft 2 is shown, which is releasably fixed at the same time with the drive shaft 113 of an electric motor 3. Thus, the drive shaft 113, as it were the schematic diagram in Figure 3c, a feedthrough channel 10, through which the cable 3 is threaded through in the manner shown in Figure 3e. In addition, the drive shaft 113 has a blind hole-like receiving opening for the front end of the shaft 2, which can be releasably fixed by means of a grub screw 13 to the drive shaft 113. A cover-like design fastening ring 12 is thereby slipped over the drive shaft 113 in the manner shown in Figure 3e and secured against the shaft 2 with the grub screw 13 described above. All edges over which the cable 3 runs within the fastening device shown in Figures 3 d and e are rounded, so that the cable 3 is not subject to any risk of buckling. The frontal opening 114 within the lid-like fastening ring 12 is formed rounded and ensures the largest possible bending or radius of curvature of the rope. Also, the orthogonal oriented to the wavelength extension face of the mounting ring 12 causes the rope 3, starting at the location of the cable outlet at the front opening 114 along the shaft 2 in doppelhelikaler, single-layer arrangement conforms directly along the shaft surface.

In Figure 4, the shaft 2 is shown in a perspective view, along which a band-shaped cable 9 is fixed by means of a mounting ring 12 and is wound in a double-helical arrangement about the shaft 2 in the manner shown. Thus, the band-shaped cable 9 does not wrap over each other and meet the Bandanlegebereiche both diametrically opposed belt sections axially at the same height on the shaft 2 a loose, axially to the shaft 2 movably arranged guide sleeve or a guide ring 14 is provided which provides two diametrically opposite openings through which the band-shaped rope 9 passes.

Of course, it is possible to provide the axially movable guide ring 14 shown in FIG. 4 for three, four or more cable feeds correspondingly with openings whose shape and size are respectively adapted to the cable to be wound onto the shaft 2. The band-shaped rope 9 shown in FIG. 4 is preferably designed as einrundendes steel strip with which when pulling on the shaft 2 high tensile and lower unwinding shear forces can be transmitted.

5 shows an embodiment of the controlled cable guide is shown in the form of a double helical coil spring, which comprises the shaft 2 radially, preferably slightly spaced. The shaft 2 is connected in Figure 5 end to an electric motor 1 and as in the preceding embodiments, the mounting ring 12 provides for the fixation of the cable 3 along the shaft, which also serves to fix the doppelhelikalen formed as a spiral spring guide slot 104 at the same time. To better distinguish the rope guides, the left half of the rope is gray and the right half of the rope black, but it is the same type of rope or the same rope. With such a device causing the rope winding, it is not absolutely necessary that the rope 3 is always taut. Thus, the double-helical guide slot 104, preferably made of commercially available compression springs or of steel, ensures that the winding points come to rest uniformly and always diametrically opposite one another axially along the shaft 2.

In contrast, only a simple helical guide slot 104 is shown in the embodiment shown in Figure 6, along which an additional sleeve-like guide ring 14 is axially slidably mounted, which has at least two diametrically opposite openings 101 each to the cable feedthrough. For sliding support of the sleeve-like guide ring 14 is a peripheral edge of the guide ring 14 radially superior slide cam 102 which is in sliding engagement with the coil spring assembly, whereby this is moved during the winding and unwinding in a defined manner in the axial direction relative to the shaft 2. In addition, two web-like projections 103, which come into contact with the respective cable sections, thereby preventing that on the one hand, the sleeve-like guide ring 14 jammed and on the other hand, the cable 3 wound around the sleeve. Of course, it is possible to combine the measures described above for the controlled winding of the rope 3 along the shaft 2 in a suitable form. Thus, the shaft 2 may be provided in all described embodiments in the manner explained above, each with groove-shaped, the shaft helically circumferential depressions, in which the cable sections are able to nestle during winding.

An alternative approach for a controlled winding of the cable 3 along the shaft 2 follows the embodiment shown in Figure 7, which shows a winding operation of a rope 3 along a shaft 2 in three different winding positions I, II and III. Thus, here a drive motor 1 is shown with an attached shaft 2, to which a cable 3 is fixedly attached by means of a fixing ring 12. For better differentiation of the respective winding positions, the left half of the rope is gray and the right half of the rope colored black, but this is the same type of rope or rope. The three different winding positions relate to the fully developed position in the position I, in the position III, the fully wound position and in the position Il a corresponding center position. An orderly winding of the cable 3 along the shaft 2 can be ensured by the cable always remains at an angle α relative to the orthogonal with respect to the wavelength extension is arranged. This requires that the cable fixing bearing, on which the respective cable ends are guided, are guided during the winding process along the straight line G drawn in dashed lines. The angle α is at the same time the pitch angle of the shaft 2 rotating double helix of Aufwickelmusters. Ideally, this angle is calculated by specifying the shaft diameter and the cross-sectional dimensions of the rope wound on load on the shaft in the following form:

wobei d_s der Wellendurchmesser und dc_e die Höhe und d_Cc die Breite des unter Spannung auf der Welle 2 aufliegenden Seils sind.

where d _{s is} the shaft diameter and dc _{e is} the height and d _{cc is} the width of the rope resting under tension on the shaft 2.

FIG. 8 shows an actuator which provides an additional device for a permanent cable pretension. The actuator provides, as in the embodiment of Figure 1 before an electric motor 1, at the shaft 2, a cable 3 is wound, which is fastened via a fastening ring 12 on the shaft 2. Reference is made to the right-hand illustration in FIG. 8 for a plan view in the shaft direction, which shows a spring 116, the ends of which are fixed on the one hand to the housing of the electric motor 1 and on the other hand to a grinding wheel 115 are fixed, which in turn is attached to the shaft 117. The connection between grinding wheel 115 and the shaft 117 is made either non-positively or via a friction clutch with a defined frictional torque. By unwinding the rope 3, the spring 116 is tensioned. If the rope 3 slackens, the torque stored in the spring 116 rotates the shaft 2 until the rope 3 is tensioned and the cable force prevents further rotation.

LIST OF REFERENCE NUMBERS

Shaft angle, motor

wave

Rope 'rope end, 5 rope mounting bearing electronic control unit

Supporting structure band-shaped rope, steel band 0 Feed-through channel 2 Fixing ring 3 Grub screw

Guide ring 01 Opening 2 Sliding cam 3 Web-like extension 4 Guide slot 12 Cable end 13 Drive shaft 14 Frontal opening 15 Grinding wheel 16 Spring 17 Shaft

Claims

claims 1. Actuator with a shaft in rotation staggering shaft drive to the shaft at least one band or rope-like element, hereinafter referred to rope, up and / or unwound, which has a rope length and two rope ends, the rope ends respectively can be connected to a cable mounting bearing, the cable mounting bearing relative to the shaft are substantially diametrically opposite, connected to the shaft rope between two rope mounting bearings a taut state and connected the rope along its rope length in a localized rope area between the two cable ends at a cable attachment to the shaft is, wherein at the cable attachment location, a limiting element is designed and placed such that cable forces attack each with respect to a shaft axis of the shaft diametrically opposed tangent points, and that upon rotation of the shaft for the purpose of winding the rope on the Both shaft ends spaced from the shaft shaft ends are movable relative to the shaft on the shaft at the same speeds, characterized in that the cable ends during winding through the Restrictive element in one layer and placed in a helical arrangement around the shaft in abutment or be placed in multiple layers, with a constant axial position relative to the shaft and with an increasing winding radius around the shaft to the plant. 2. Actuator according to claim 1, characterized in that the means in the form of a limiting element has a fastening ring which surrounds the shaft at the cable attachment point and fixed the rope relative to the shaft so that the tensioned around the shaft ends have a rope longitudinal extension, the with the shaft an angle ß with 90 ° <ß <0 °, preferably 70 ° <ß <20 °. 3. Actuator according to claim 1 or 2, characterized in that the means comprises a shaft surrounding the guide ring, which is mounted longitudinally movable axially to the shaft and having at least two diametrically opposed openings through which one end of the rope is guided loose. 4. Actuator according to one of claims 1 to 3, characterized in that the means comprises a guide slot provided along the shaft, which forcibly guides the cable ends during winding on the shaft to form a single-layer loop formed in a helical arrangement. 5. Actuator according to claim 4, characterized in that the guide slot is formed in the form of a doppelhelikalen guide contour which surrounds the shaft helically in the nature of two groove-shaped depressions. 6. Actuator according to claim 4 or 5, characterized in that the guide slot is formed spiral spring-like and the shaft rotates in doppelhelikaler training. 7. Actuator according to claim 4, characterized in that the guide slot a shaft at least partially axially helical comprehensive coil spring arrangement provides that has a shaft radially and axially surrounding helical gear, in which a sleeve-like guide means is mounted axially sliding, the at least two diametrically opposite Has openings for each cable entry. 8. Actuator according to claim 7, characterized in that on the radially outer peripheral edge of the sleeve-like guide means a radially outwardly projecting the peripheral edge Sliding cam is provided which can be brought into sliding engagement with the coil spring assembly. 9. Actuator according to claim 7 or 8, characterized in that in each case in the region of an opening a peripheral edge radially projecting web-like extension is provided on which each of the guided through the opening side slidably abuts and is prevented from uncontrolled around the peripheral edge of sleeve-like guide to wrap. 10. Actuator according to one of claims 4 to 9, characterized in that the guide slot provides an axial extent along the shaft and at the site of the cable attachment point is connected on one side adjacent to the shaft. 11 actuator according to one of claims 1 to 10, characterized in that the cable fixing bearing relative to the fixed to a Support shaft mounted shaft drive together with shaft are loosely mounted or that the shaft drive together with the shaft and one of the cable mounting bearing are mounted loosely relative to the other, fixedly attached to a support structure cable mounting bearings. 12. Actuator according to claim 2 and 11, characterized in that the cable fixing bearings are guided along an orthogonal to the shaft oriented linear guide such that the angle ß is selected in an unwound state of the shaft so that ß remains virtually unchanged during the winding and is approximately equal to the pitch angle of the helical winding on the shaft. 13. Actuator according to one of claims 1 to 11, characterized in that the shaft drive along shaft along a linear guide is mounted so linearly movable, that the weight of the shaft drive of the linear guide is receivable, and that a first cable mounting bearing and the shaft drive together wave linearly movable relative on the other rope attachment bearing, which is fixedly mounted on a support structure are stored. 14. Actuator according to claim 13, characterized in that the linear guide is firmly connected to the support structure. 15. Actuator according to one of claims 1 to 14, characterized in that the rope in the form of a steel cable, steel wire rope, a plastic or nylon cord, a steel or plastic band is formed. 16. Actuator according to one of claims 1 to 15, characterized in that the shaft drive is designed as an electric motor with an output shaft. 17. Actuator according to one of claims 1 to 16, characterized in that the cable for attachment to the shaft projects through a shaft passing through the radial bore. 18. Actuator according to one of claims 1 to 16, characterized in that the cable for attachment to the shaft by means of a fastening means on the outer circumference of the shaft is fixable. 19. Actuator according to one of claims 2 to 18, characterized in that the rope is fixed relative to the shaft so that the rope longitudinal extension relative to the shaft includes an optimum angle α:

where d _{s is} the shaft diameter and dc _{e is} the height and dc _{c is} the width of the rope resting under tension on the shaft.