EP1848900A2

EP1848900A2 - Electromotive linear drive

Info

Publication number: EP1848900A2
Application number: EP06708323A
Authority: EP
Inventors: Heinrich Dück; Christian Müller
Original assignee: Dewert Antriebs und Systemtechnik GmbH and Co KG
Current assignee: Dewertokin GmbH
Priority date: 2005-02-17
Filing date: 2006-02-16
Publication date: 2007-10-31
Also published as: JP2008530471A; WO2006087365A3; US20090044646A1; AU2006215577A1; WO2006087365A2; AU2006215577A2; DE202005002585U1; JP5114214B2; US8281677B2

Abstract

The invention relates to an electromotive linear drive (10), which contains a speed reduction gear unit that is coupled to a drive motor for driving a spindle (11), a spindle nut (13) being placed on said spindle (11). The linear drive (10) is additionally equipped with a braking assembly (14), in order to regulate the speed of the spindle (11). The aim of the invention is to configure said drive simply in such a way that it is no longer necessary to decouple the drive function of the drive unit, formed by the drive motor and the speed reduction gear, from the spindle (11). According to the invention, the spindle nut (13) is equipped with a braking assembly (14) that comprises a coil spring (17) and the force that is transmitted by the coil spring (17) to a component (16) lying in said spring can be controlled, to allow the speed of the spindle (11) to deviate from the normal speed. Said linear drive (10) is particularly suitable for displacing the mobile components of a piece of furniture.

Description

Electromotive linear drive

The invention relates to an electromotive linear drive with one of a

Drive unit and a Drehzahlreduziergetriebe formed drive unit for driving a spindle on which a spindle in the longitudinal direction of the spindle directionally movable spindle nut is placed, which stands with a synchronously movable lifting tube in an adjustment, on the free, the drive unit remote end mounted a connector is, and that by means of a equipped with a braking and transmission means brake assembly, the linear velocity component of the lifting tube is adjustable at least when the drive motor is switched off.

The electromotive linear drive in question can be used for a variety of

Adjustment functions are used to adjust with the connection part of the lifting tube coupled components. This can be done directly, for example via a lever or a fitting. The adjustment of the connected components is relatively low, since the speed of the spindle when the drive motor is also relatively low. The opposite adjustment movements of a connected component are normally carried out with the drive motor, that is, the adjustment of a connected component depends on the direction of rotation of the spindle or whether the spindle nut is moved in the direction away from the drive unit or towards the drive unit.

There are cases of application in which the normally adjusted by means of the linear drive component is to be abruptly moved automatically into a starting position, that is, by its own weight. For these cases, linear drives are known in which, for example, by a coupling, the drive connection between the drive unit and the spindle is interrupted by a so-called uncoupling. In the industry, this process is called the disengagement of a drive. If the drive connection between the drive unit and the spindle is interrupted or disengaged and the threaded spindle is not self-locking, the connected component abruptly moves into a starting position due to its own weight. Because this particular is to be avoided in the application in the furniture sector, it is already known to equip the disengaging or uncoupling with a brake assembly, so that the speed of the Entkuppeleinheit is rotatably adjustable with respect to the drive housing, so that the speed of the spindle can be controlled, if the drive connection between the drive unit and the spindle is interrupted.

The linear drives in question are to be regarded as mass products, which are to be manufactured as simply as possible and consequently also as inexpensively as possible. In the known linear drives with brake assemblies for controlling the speed of the spindle with the drive motor off not only the brake assemblies are necessary, but also the Entkuppeleinheiten. Consequently, the design effort is relatively high, so that the cost of producing the linear drives are correspondingly high.

The invention has for its object to design a linear drive of the type described in more detail in a structurally simple manner and a minimum number of components so that in the case of a meaningful disengagement the displacement of a component connected to the linear drive component is increased with the drive motor from the normal speed and by the regulation of the linear velocity component of the lifting tube.

The object is achieved by the spindle nut is in operative connection with the brake assembly, that in the adjustment of the lifting tube with the drive motor, the spindle nut frictionally with the spindle in a drive function and is non-rotatably arranged by housing parts of the linear drive, and at least when the drive motor is switched off, the force acting on the spindle nut by the brake unit can be reduced in a regulated manner, so that the spindle nut is capable of rotating, that the linear speed component of the lifting tube can be influenced by the braking force transmitted to the spindle nut by the brake assembly. Due to the operative connection between the brake assembly of the spindle nut according to the invention eliminates the hitherto necessary disengaging or uncoupling of the gear train. In the normal case, that is, in both directions of rotation of the spindle when the drive motor is activated, the spindle nut is secured against rotation by the force acting on the spindle nut of the brake assembly, so that it moves depending on the direction of rotation of the spindle in the longitudinal direction. As a result, a component connected to the linear drive can be adjusted with the speed component resulting from the rotational speed of the spindle, wherein the adjusting movement of the component can also be a pivoting movement. However, if, for example, when lowering the component, the adjustment speed can be increased, the speed is not determined by the speed of the spindle, but by acting on the spindle nut, applied by the brake assembly force, since the spindle nut can rotate relative to the spindle. This is still possible even when the drive motor is switched on. As a result, the speed of the component connected to the linear drive is determined by the linear velocity component of the spindle nut. The spindle nut can also be moved linearly with respect to the spindle during rotation of the spindle. The particular advantage of the arrangement according to the invention lies in the fact that no decoupling or disengaging unit is necessary for adjusting a component with respect to the normal speed of increased speed. In contrast to the previously known embodiments, the adjustment of a component is independent of the spindle no longer by the drive technology decoupling in the area between the drive unit and the spindle, but in the area between the spindle nut and the connecting part of the lifting tube. This free movement of the component can, depending on the design of the linear drive in the region between the spindle nut and the housing or between the spindle nut, a housing part and the housing or between the spindle nut, a guide member and the housing or in the region between the spindle nut and the hub - Roehr lie.

Thus, it is provided in a first embodiment, that the lifting tube is arranged non-rotatably, and that the spindle nut is rotatably supported by means of a bearing element firmly inserted into the lifting tube. This bearing element acts schleißmindernd and is in a preferred embodiment made of a sliding bearing material bearing bush, an axial sliding or rolling bearings. However, it is also possible alternatively to use a rolling bearing and in a preferred embodiment, a needle bearing.

The connection of the lifting tube with the spindle nut can be done in various ways. Thus, it is provided that the lifting tube is fixedly connected to the spindle nut, and that the lifting tube is rotatably mounted with its free end portion in the connecting part. If then the adjustment speed of the connected component is to be increased by reducing the force applied by the braking and transmission means, the lifting tube can rotate synchronously with the spindle nut.

The braking and transmission means described above forward the forces to other components by friction. In a preferred embodiment is a

Braking and transmission means formed by at least one wrap, the closer structure will be explained later. Other braking and transmission means may be frictional clutches such as multi-plate clutches, cone clutches, disc brakes or shoe brakes. Also combinations of several similar or similar or different types of couplings and

Brakes are possible.

In a further embodiment it is provided that the spindle nut is rotatably guided by a housing part, wherein the housing part is rotatably mounted within the housing relative to the housing of the electromotive linear drive. If now the adjustment speed of the connected component to be changed, the housing part can rotate synchronously with the spindle nut relative to the housing by influencing the brake assembly.

According to a further embodiment it is provided that the spindle nut is rotatably guided by a guide member, wherein the guide member is rotatably mounted relative to the housing of the electromotive linear drive. Provided that the adjustment speed of the connected component are changed should, by influencing the brake assembly, the guide member rotate synchronously with the spindle nut relative to the housing.

Advantageously, the braking and transmission means of the brake assembly can be formed from at least one wrap spring, a multi-disc clutch, a cone brake, a disc brake, a jaw brake or the like. These are tried-and-tested components in the industry, which are simple in construction and reliable in operation.

In a preferred embodiment it is provided that the brake assembly consists of at least one rotatably mounted on the spindle nut bushing, at least one bush surrounding the brake and transmission means or a wrap spring and an externally operable handle, wherein an end portion or a central region of the brake - And transmission means or the wrap spring or the wrap springs with the handle is in operative connection or stand. In this case, at least one wrap spring may consist of a helically bent section with a plurality of turns, which has at least one section in the end and / or in the middle region, which deviates from the shape of the helical section. With a first end or a middle region, the wrap spring is non-rotatably connected via a component to the housing or to a housing part or to a guide part of the electromotive linear drive. The other end of the wrap spring is pivotally movable relative to the first or relative to the central region of the wrap around the axis of rotation of the turns, so that the diameter of the wrap around the Drehach- se of the turns pivotally movable so that the diameter of the wrap spring is changeable ,

In this case, all sections of the brake and transmission means or all sections of the wrap spring can be actuated together or in succession, so as to regulate the braking effect together or in a specific order one after the other. In this arrangement, the braking and transmission means transmits the force necessary to Unverdrehbarkeit the spindle nut indirectly to the spindle nut. The braking and transmission means is biased so that the necessary force for the unrotatability of the spindle nut is generated. The Handle is designed so that as sensitive as possible, this force is reduced, since upon actuation of the handle, the wrap is widened, so that the force acting on the bushing force is reduced so that the adjustment speed of a connected component can be controlled.

The brake and transmission means or the wrap can be firmly connected to this handle, but it is provided in a preferred embodiment, that the handle has a shift rod whose central longitudinal axis is parallel and spaced from the central longitudinal axis of the spindle and the axis of rotation relative to the own Center longitudinal axis is offset. In a figurative sense, this creates an eccentric arrangement, so that upon actuation of the handle the brake and transmission means or the wrap spring is already actuated when it rests with one end on a nose and the shift rod acts against this end.

Since the linear drives in question are not only intended to be produced cost-effectively, but also that they are extremely compact, it is provided that the handle still has a switching ring, which rotatably mounted on the mounted on the spindle nut, operatively connected to the wrap spring socket. Gert is and which is actuated by the shift rod, wherein an end portion of the

Wrap is set in the switching ring.

It is also advantageous if the shift rod is designed as a profile bar which has a circular arc-shaped outer contour on at least one longitudinal edge region and a central constriction on at least one side. Through this

Design is an extremely simple storage of the shift rod possible, since it is rotatably mounted with its circular arc-shaped outer contour in a guide channel formed from guide webs of the housing or an attached to the housing flange tube guide channel. The guide webs are adapted to the circular arc-shaped contour of the shift rod and encompass the area by more than 180 °. The constriction at least on one side then allows the rotational movement of the shift rod. In a preferred embodiment, however, the shift rod is provided on each side in the central region with a confiscation. As a result, a symmetrical cross-section is achieved, with respect to the center axis perpendicular to one another. sen. The semicircular outer contour of the shift rod is facing away from the brake and transmission means or the wrap spring in this execution. The shift rod extends substantially over the region of the spindle, so that in each position of the spindle nut on this by the brake and transmission medium or by the wrap spring force can be reduced.

In another embodiment, the shift rod has an annular cross-section or an annular cross-sectional portion, the center of the circle extends along or parallel to the central longitudinal axis of the spindle. To reduce the force acting on the spindle nut, the shift rod can be rotated about an axis of rotation or moved along an axis. A combination of a rotary and a sliding movement of the shift rod may be possible.

Another embodiment provides a shift linkage with more than one shift rod. In this case, the shift rails can move relative to one another both about an axis and in an axis, so that, moreover, a movement relative to the housing of the electromotive linear drive can also take place at the same time. In this case, a shift rod or a shift linkage both by a rigid, such as a rigid and / or torsionally rigid

Element may also be formed by a flexible strand which is flexible at least in one degree of freedom.

Thus, the spindle nut is guided securely in the process along the spindle, it is provided that it has a guide ring in the central region, that on both sides of this guide ring are provided smaller in diameter projections of the spindle nut, that on at least one approach a socket is rotatably mounted, that at least one bush is surrounded by the braking and transmission means or the wrap spring, and that the other bushing is mounted in the bearing element or that the lifting tube is mounted on the other shoulder.

Since the shift rod is arranged in the intermediate space between the movable lifting tube and the fixed flange tube or the housing, it is provided that the flange tube or the housing is equipped with corresponding guide webs for the spindle nut. In this embodiment is still provided the bushing surrounding the wrap spring faces the drive unit and the bushing of the drive unit mounted in the bearing element faces away from the drive unit. The bushes can be made in a preferred manner of a metallic material, such as steel. The spindle is also made of steel, while the spindle nut is made of a plastic.

In addition, it is provided that one of the sockets, preferably the bush surrounded by the braking and transmission means or the wrap spring, is equipped with a switching cam for actuating end switches which determine the end positions of the spindle nut.

This bushing with the switching cam has, in addition to the switching cam, further webs which, like the switching cam, extend in the longitudinal direction of the spindle and extend in longitudinal grooves of the housing, a housing section, a guide part or a flange tube. Thus, a non-rotatable and longitudinally displaceable connection between the first end portion or central region of the braking and transmission means or the wrap spring and the housing is provided.

In a further embodiment, the socket with the switching cam and the

Bars firmly connected to the spindle nut. In this case, the brake and transmission means or the wrap spring is now connected to a housing section, a guide part or a flange tube in such a way that the adjustment speed of the connected component is changed when the force applied by the brake and transmission means or the wrap spring is reduced. For this purpose, said housing section, the guide member or the flange tube is rotatably mounted relative to the housing of the linear drive.

The outer, surrounding the region of the spindle flange tube or the region of the housing is designed in its basic contour oval-shaped, wherein on the inner surface

Webs are formed for storage of the shift rod and for guiding the spindle nut. In a further preferred embodiment, it is provided that the electromotive linear drive is designed as a furniture drive, preferably as a single drive, to adjust adjustable components of furniture, such as slatted frames, hospital and nursing beds and armchairs.

Furthermore, sealing elements are provided at least at the abutting edges of the housing parts, which prevent the penetration of liquids or solids into the housing. In addition, parts of the outer skin of the linear drive can be made corrosion-resistant. Thus, there are other applications, such as adjustment of ventilation flaps, lifting devices, pan and slide elements,

Doors and gates both inside and outside the building, so that the linear drive is protected against weather, dirt and moisture.

The electromotive linear drive has a housing section for receiving the spindle nut and essentially also the spindle. This formed as a flange tube housing portion may be fixedly connected to the housing of the linear drive. In one embodiment, an element in the form of a flange or an adapter is arranged between the flange tube and the housing. The flange tube may be fixedly connected to the flange while these

Flange flange tube assembly is detachably connected to the housing so that in different rotational angular positions, this unit can be fixed to the housing.

Particularly advantageous is an embodiment of the electromotive linear drive, in which one end of the braking and transmission means or the wrap is firmly connected to another ring having a switching cam and in the longitudinal direction of the spindle extending webs, which are guided in longitudinal grooves of the flange tube , And that in the flange pipe limit switches for the end stop of the electric motor are installed in the respective end position, and that the limit switches are actuated by switching cam.

Furthermore, the electromotive linear drive is designed as a single drive, that is, it is equipped with a spindle and a spindle nut mounted thereon. tattet. However, it is also conceivable that the linear drive is designed as a so-called double drive, which is equipped with two spindles and two spindle nuts, which are driven by two drive motors or by a drive motor. If a drive motor is used, the respective speed-reducing gearbox driving the spindle can be switchable via coupling elements.

According to a further embodiment, it is provided that the lifting tube in the connection region with the spindle nut has an internal thread, which is in engagement with an external thread of the spindle nut. Conveniently, the internal thread is a fine thread, so that a very accurate setting of the

Pipe opposite the spindle nut is possible. The spindle nut itself has an internally threaded bore, wherein the threads are formed as a movement thread, preferably as a trapezoidal thread.

Thus the largest possible braking torque by the wrap spring or by the

Rolling springs can be applied, it is provided that a support sleeve is placed on the lifting tube in the spindle nut associated area, which has an inwardly directed annular projection, and that the spindle nut, the lifting tube and the support sleeve mutually aligned recesses, in the form-fitting connection of these components connecting elements, connecting portions, for example, engage or attack feather keys.

As an alternative to this support sleeve, the lifting tube in the end region assigned to the spindle nut could also have a larger outer diameter than the rest of the region. In this case, the support sleeve would be integrated into the lifting tube mutatis mutandis. In another embodiment, the bush with the lifting tube and / or the carrier sleeve could form a one-piece molded part. Alternatively, it would also be possible for the carrier sleeve and the lifting tube to be positively connected to one another, for example by means of threads or deformation sections. In a further development of this embodiment, the carrier sleeve can be attached to the lifting tube and / or have cross-sectional portions which may be web-like. It is provided in this embodiment that one or more wrap springs are placed on the carrier sleeve, wherein each inner diameter in the unmounted state is a little smaller than in the mounted state. As a result, the inner circumferential surface of each wrap spring is frictionally engaged directly with the carrier sleeve. In a preferred embodiment, the bushing is connected by connecting portions, for example by knurls or a tooth profile or connecting elements, for example by a plurality of feather keys with the support sleeve and / or with the lifting tube and / or with the spindle such that at least torques transmitted from the socket to the spindle nut are. The support ring is also provided in this embodiment with a longitudinal slot and arranged loosely between stepped lugs or discs such that it transmits a frictional force of the associated wrap spring on the carrier sleeve, preferably transmits a torque frictionally from the associated wrap spring on the spindle nut.

To secure the position of the arrangement in the region of the connecting elements or connecting portions or the feather keys, a bearing ring is placed on the feather keys, which has an angular cross-section, wherein recesses are formed on the inner circumferential surface, which engage over the feather keys. The area of the smaller diameter of the bearing ring faces the drive motor or the speed reduction gear. On this side adjacent to the bearing ring a disc is attached, so that an open annular groove is formed. In this annular groove engages an approach of the guide flange, so that it is rotatable in the annular groove, but secured against axial displacement.

Another embodiment provides a lifting tube, which has a large wall thickness, at least in one end region, so that the lifting tube forms a one-piece molded part at least with the carrier sleeve and / or the bushing. In continuation of this embodiment, the spindle nut could also have a section which is designed at least as a carrier sleeve and / or as a lifting tube.

The pitch direction of the threads of both the spindle, the spindle nut, and an additional nut are advantageously in a first direction preferably designed as a right-hand thread. Accordingly, the electromotive linear drive is designed so as to generate adjusting forces, preferably in a first direction of movement. In another embodiment, the threads are formed in a second pitch direction, which is opposite to the first pitch direction, so that the linear drive generates an adjusting force in a second direction of movement.

A further embodiment provides that the carrier sleeve is associated with a guide device, whereby the guidance of the brake assembly is favored in the flange tube. For this purpose, grooves or lugs may be formed on the carrier sleeve, which correspond with the guide device. The guide device itself may be formed as a ring or as a ring portion, but is rotatably mounted with the support sleeve rotatable lengthwise and guided with the outer surface in the flange tube.

One end of each wrap spring is angled and engages in a corresponding recess of the guide flange, wherein the second end of each wrap is in operative connection with a switching ring. Each switching ring is rotatably mounted relative to the guide flange such that upon rotation of the switching ring, the diameter of the associated wrap spring is variable. Furthermore, it is provided that the angled end of the wrap spring is associated with an element having a higher strength than the guide flange.

It is further provided that the outer contour of the carrier sleeve is stepped. It is then possible that on each shoulder of the switching ring, the support ring, the

Support disc and the sleeve in the axial direction, so that at least these components are secured against displacement in one direction.

For additional protection against axial displacement, a retaining ring can engage in a groove of the carrier sleeve, so that at least the socket and / or a

Switching ring is secured against axial displacement. It may then be advantageous if the retaining ring is assigned to another disc. It is also advantageous if the carrier sleeve is formed from a metallic or non-metallic material, are placed on the metallic sleeves or sockets, for example made of a hardened steel. It is also advantageous if a control cam is still formed on the guide flange, so that a limit switch can be actuated in order to switch the current flow of the electromotive drive in an end position range. For exact guidance of the arrangement is still provided that webs are integrally formed on the guide flange, which engage slidably in correspondingly shaped longitudinal grooves of the flange tube. It is further provided that the annular projection of the support sleeve forms a spacer element, and that on the side facing away from the spindle nut an additional nut is mounted in the support sleeve. Alternatively, this additional nut could be inserted into the lifting tube or coupled with the spindle nut. The additional nut has a circumferential groove into which a holding element, for example an O-ring is inserted, so that the additional nut is connected to the carrier sleeve. The retaining element is expediently elastic.

In the preferred embodiments, the Hubrohre are firmly connected to the spindle nuts. In such embodiments, it is expedient if the connection parts for connection of the electromotive linear drive are rotatably mounted on adjustable relative to other components components at the free ends of the lifting tubes. It is particularly advantageous if each connection part is designed as a clevis with a central slot and a transverse bore. However, other embodiments of each connecting part are possible, for example, flanges or pins, which have longitudinal and / or transverse bores or steps and threaded heads.

The rotatably mounted connection part is designed in a preferred embodiment as a structural unit, so that it can be used or attached in or at least partially in or on the free end of the lifting tube. This assembly consists essentially of a first component, which is firmly connected to the lifting tube, for example by means of threads or deformations. A second part is then mounted to this first component so that it is rotatable. The rotatable component is equipped with at least one bearing element, which is designed as a rolling bearing and / or as a sliding bearing and / or as a combination thereof, so that Forces are received in both the radial and in the axial direction between the first component and the second component, wherein at least the axial forces can be introduced into the lifting tube.

In the embodiments shown at least one sealing element is still provided, which protects the storage from the outside against the ingress of dust and moisture. Another embodiment also provides a connecting element, which connects the first and the second component with each other and supports each other. In a preferred embodiment, the connecting element is formed by a screw which is passed through the first and second component and is screwed into the second or in the first component. Alternatively, the connecting element may also be a pin or a bolt, which is formed as a one-piece molded part with the first or with the second component.

Reference to the accompanying drawings, the invention will be explained in more detail. Show it:

Figure 1 shows an electromotive linear drive according to the invention in a partial view, the spindle associated area;

Figure 2 shows the area shown in Figure 1 in a sectional view;

FIG. 3 shows an enlarged view of the area marked in FIG. 2, containing the spindle nut;

FIG. 4 is a perspective view of the region according to FIG. 1;

Figure 5 shows the area according to the figure 2 in perspective and in section;

FIG. 6 is a perspective view of the region according to FIG. 3; Figure 7 is an end view in the direction of the arrow VII in Figure 6;

Figure 8 shows a possible embodiment of a wrap spring;

Figure 9 shows a further embodiment of the linear drive according to the invention in sectional view and

FIG. 10 shows the embodiment according to FIG. 9 in a view.

For the sake of simplified illustration, only the part of the linear drive 10 affected by the invention is shown in FIGS. 1 to 6. As the figures show, this area includes a spindle 11 which is driven in rotation by a drive unit, not shown. The drive unit consists of a drive motor in the form of a DC motor and a Drehzahlreduziergetriebe, which consists of a worm drive in a preferred embodiment, since such

Shoots provide a high speed ratio. In the illustrated embodiment, the spindle 11 extends within an outer, fixed to a housing, not shown, flange 12, which may also be integrally formed with the housing. The free, the drive unit remote from the end of the Flanschrohres 12 is closed by an end cap 33. On the spindle 11 a explained in more detail with reference to FIG 3 spindle nut 13 is placed, which is in operative connection with a still further explained brake assembly 14. The spindle nut 13 is connected to a lifting tube 15 such that the lifting tube 15 with respect to the flange tube 12 depending on the direction of rotation of the spindle 11 and retractable.

The braking device 14 consists essentially of a non-rotatably mounted on the spindle nut 13 bushing 16, a bush 16 surrounding wrap spring 17 and a relative to the sleeve 16 rotatable switching ring 18, which can be seen in Figures 6 and 7. Since the inner diameter of the wrap spring 17 after manufacture is smaller than the outer diameter of the bushing 16, a bias is built up due to the elasticity, so that it rests non-positively on the outer circumferential surface of the bush 16. The associated end of the wrap spring 17 is fixedly connected to the switching ring 18. The opposite End of the wrap spring 17 is fixedly connected to a second ring having a switching cam 19 and webs not shown, which are guided in longitudinal grooves of the flange tube 12. In the flange 12 are still housed limit switch 20 for the end of the electric motor in the respective end position. These limit switches 20 are actuated by the switching cam 19.

Contrary to the illustration, the bushing 16 could also be surrounded by more than one wrap spring 17 or loop spring sections 17a, 17b. The wrap springs 17 could form a spring assembly, wherein the individual wrap springs 17 could be coupled together with their facing Stirnendbereichen. However, they can also have a winding-free section in a bending process and be interconnected continuously with a blank.

The spindle nut 13 is provided in the central region with a guide flange 21, which is guided on the inside of the flange tube 12. On both sides of this guide flange 21, the spindle nut 13 is provided with smaller projections 22, 23. On the neck 22 which is surrounded by the wrap 17 bushing 16 is firmly placed. The connection of this approach 22 takes place positively by longitudinal webs which engage in corresponding grooves of the counterpart. On the neck 23, a bush 24 is fixedly mounted, which is mounted in a plain bearing bush 25 which is firmly inserted in the lifting tube 15. As the figure 3 shows, are the

Sockets 16 and 24 designed angular in cross-section. The brake assembly 14 is facing the drive unit, not shown.

Figures 4 and 5 show the part of the linear drive 10 in a perspective view. These figures show that a connection element in the form of a clevis 26 is fixedly mounted on the free end of the lifting tube 15 facing away from the drive unit. Figures 4 and 5 show particularly clearly that the basic contour of the Flanschrohres 12 is oval-shaped, and that the spindle 11 is in an offset to the central longitudinal axis. In particular, Figure 4 shows that on the inside of the flange 12 webs are formed to support a handle 27 for actuating the switching ring 18 and to guide the spindle nut 13. As shown in particular Figures 6 and 7, the handle 27 consists of a switching rod 28 in the form of a profile bar. The shift rod 28 contacts a nose of the shift ring 18, so that it is rotatable relative to the spindle nut 13 to widen the wrap spring 17. The shift rod 28 extends substantially over the region of the spindle 11, so that the switching ring 18 can be rotated in any position of the spindle nut 13. In addition, the shift rod 28 is located in a free space between the lift tube 15 and the flange tube 12. The shift rod 28 is parallel and spaced from the spindle 11. In addition, the

Rotary axis of the shift rod 28 in offset from the central longitudinal axis, so that mutatis mutandis the effect of an eccentric is achieved, whereby the rotation of the switching ring 18 is effected.

FIG. 7 shows that the switching rod 28 consists of two round rods connected to one another via a web or the region facing away from the spindle 11 is circular arc-shaped, at least semicircular, and lies within a channel which is formed from two correspondingly shaped webs 29, 30 , Overall, embrace the webs 29, 30, the shift rod 28 by an angle which is greater than 180 °, so that the shift rod 28 is rotatable in the channel formed from the webs 29, 30 rotatable. For this rotation is possible, the shift rod 28 is provided in the middle region on both sides with recoveries. The region facing the spindle 11 contacts a web 18a of the switching ring 18, since the web 18a is directed outwards. In a manner not shown, the shift rod 28 can be by a lever attached to the outside of the housing or a

Turn the slide. For this purpose, the housing of the linear drive 10 or the flange tube 12 is provided with a corresponding opening. In the region opposite the shift rod 28 area a retaining rail is inserted into the flange tube 12, which may, however, also be formed from integrally formed webs. This support rail includes a linear potentiometer 31 with a slider 32 which is coupled to the spindle nut 13 and moves in synchronism with it in the longitudinal direction of the Flanschrohres 12 to determine the respective position of the spindle nut 13 with the drive motor off.

It should be noted that the spindle 11, the bushing 16 and the lifting tube 15 made

Steel are made while the spindle nut 13 and the housing consist essentially of a plastic. The flange tube 12 may be made of a plastic or aluminum. In normal operation, that is, when the coupled to the linear actuator 10 component is adjusted with the drive motor depending on the direction of rotation of the spindle 11, 17 is transmitted from the prestressed wrap spring such a force on the sleeve 16, that the form-fitting connected spindle nut 13 is not rotates, consequently, in the longitudinal direction of the spindle 11 is moved. However, if the connected component to be lowered at a higher speed, the shift rod 28 is rotated from the outside according to the counterclockwise a little, so that the wrap spring 17 widens, whereby the force exerted on the bush 16 and the resulting force Friction torque is reduced. However, the wrap spring 17 can also be widened so far that no force is transmitted to the bushing 16, so that the connected component is lowered at an increased speed. Once the actuator is released for the shift rod 28, the wrap 17 retracts completely, so that the spindle nut 13 is completely braked and can not turn. The spindle nut 13 is not positively secured against rotation in contrast to the previously known embodiments, but non-positively by the action of the wrap spring 17. The Drehzahlreduziergetriebe can be designed so that it is self-locking, so that the force generated by the connected component with the drive motor off is held by the Drehzahlreduziergetriebe.

Figure 8 shows a preferred embodiment of the wrap spring 17 used. Thereafter, this wrap spring 17 consists of two spaced sections 17a, 17b, which in the illustrated embodiment have the same number of turns and are spaced. The connection is made by a central web 36, which runs parallel and at a distance from the central longitudinal axis of the wrap spring 17, that is, it lies in the region of the turns of the sections 17a and 17b. Furthermore, FIG. 8 shows that the free end regions 34, 35 of the wrap spring 17 or of the sections 17a, 17b are angled outwards. They engage in the adjacent components, as already described.

FIG. 9 shows a longitudinal section of the electromotive linear drive 10. For reasons of simplified illustration, the housing and the flange tube are not shown in this figure. The lifting tube 15 is on the spindle nut 13th associated end region provided with a thread, which is designated by the reference numeral 46. The internal thread is a fine thread in a preferred embodiment and is in engagement with a corresponding external thread of the spindle nut 13. The spindle nut 13 is screwed into the lifting tube 15 and connected via this thread 46 with the lifting tube. The spindle nut 13 additionally has an internally threaded bore, which is equipped with flanks of a movement thread. In the illustrated embodiment, the movement thread is a trapezoidal thread.

On the lifting tube, a support sleeve 37 is placed in the associated end region, which has a stepped inner bore. This carrier sleeve is made of plastic or a metal. The spindle nut 13, the lifting tube 15 and the support sleeve 37 have mutually aligned recesses, in which a plurality of connecting elements in the form of feather keys 42 are used, so that the spindle nut 13, the lifting tube 15 and the support sleeve 37 are firmly connected.

Contrary to this representation, the end region of the lifting tube 15 assigned to the spindle nut 13 could be correspondingly thick-walled, so that in this case the carrier sleeve is integrated in the lifting tube. In a manner also not shown, the support sleeve 37 and the lifting tube 15 could be positively connected to each other, for example by threads or deformation sections.

On the carrier sleeve 37, two wrap springs 17 are placed in the illustrated embodiment at a distance from each other. In the unmounted state, the inner diameter of the wrap springs 17 are a little smaller than in the mounted state. As a result, the inner lateral surfaces of the two wrap springs 17 are directly frictionally engaged with the carrier sleeve 37. In a preferred embodiment according to FIG. 9, the left-hand wrap spring 17 on the left is shown in FIG

Socket 16 attached. The right loop spring 17 in the illustration is placed on a support ring 44. In the illustrated, preferred embodiment, the bushing 16 by connecting elements, for example by a plurality of keys 42 with the support sleeve 37 and / or with the lifting tube and / or with the Spindelmut- ter 13 connected, so that at least torques from the sleeve 16 can be transmitted to the spindle nut 13.

The support ring 44 is provided in the illustrated preferred embodiment with a longitudinal slot and is loosely between staged approaches or discs 40 and transmits the frictional force of the associated wrap spring 17 on the support sleeve 37 and frictionally transmits a torque from the associated wrap 17 on the spindle nut 13th ,

Furthermore, FIG. 9 shows that a bearing ring 43, which has an angular cross-section, is placed on the region of the feather keys 42, wherein recesses are formed on the inner jacket surface, which engage over the feather keys 42. On the front side of the bearing ring 43 with the smaller diameter, a disc 40 is attached, so that an outwardly open annular groove is formed. In this annular groove engages an approach of the guide flange 21, so that it is rotatably mounted in this annular groove, but secured against axial displacement. One end of each wrap spring 17 is angled and engages in a corresponding recess of the guide flange 21 a. The second end of each wrap spring 17 is in operative connection with a switching ring 18. Each switching ring 18 is rotatably mounted relative to the guide flange 21 so that upon rotation of a

Switching ring 18, the diameter of the respective switching ring 18 associated wrap 17 changes.

The carrier sleeve 37 has a stepped outer contour. On the surfaces of a stepped shoulder to the next step paragraph, the switching ring 18, the

Support ring 44, the disc 40 and the sleeve 16 in the axial direction, so that they are secured against displacement in this direction.

Further securing elements, for example in the form of a securing ring 41, engage in a groove of the carrier sleeve 37 and secure at least the bushing 16 and / or a switching ring 18 against axial displacement. It may be advantageous if the retaining ring 41 is still associated with a disc 40. On the guide flange 21, a switching cam 19 is further formed by a non-illustrated limit switch can be actuated to switch in a Endlagenbereich the current flow of an electric motor drive unit, not shown.

There are also webs, not shown, which are integrally formed on the guide flange 21 and which are slidably movable in longitudinal grooves of the flange tube 12. As FIG. 9 shows, the carrier sleeve 37 is provided with an inwardly directed annular shoulder against which an additional nut 38 is supported on the outer side facing away from the spindle 11 or the spindle nut 13.

This additional nut could also be used contrary to the representation in the lifting tube 15 or coupled to the spindle nut 13. The additional nut 38 has a circumferential radial groove into which a holding element 39 is inserted. This holding element connects the additional nut 38 with the carrier sleeve 37. In a simplest way, the holding element 39 is designed to be elastic. In the illustrated embodiment, it is formed by an O-ring.

FIG. 10 shows the position between the guide flange 21 and the switching ring 18 or the switching cam 19. As a result, a compact design and a convenient operation are achieved. In addition, the figure shows that the carrier sleeve 37 projects relative to the switching ring 18.

reference numeral

10 linear drive

11 spindle

12 flange tube

13 spindle nut

14 brake assembly

15 lifting tube

16 socket

17 wrap

17a, 17h) sections

18 switching ring

18a footbridge

19 switching cams

20 limit switches

21 guide flange

22, 23 approaches

24 socket

25 plain bearing bush

26 clevis

27 handle

28 shift rod

29, 30 bridges

31 linear potentiometers

32 grinders

33 end cap

34, 35 end areas

36 middle bridge

37 Carrier sleeve

38 additional nut

39 retaining element (O-ring)

40 slices

41 circlip

42 feather key Bearing ring Support ring Ring-shaped approach thread

Claims

protection claims

1. An electromotive linear drive (10) with a drive unit formed by a drive motor and a Drehzahlreduziergetriebe drive unit for driving a spindle (11) on which in the longitudinal direction of the spindle (11) drehrichtungsab- dependent movable spindle nut (13) is placed with a synchronous movable lifting tube (15) is in an adjustment function, on the free end facing away from the drive unit, a connection part (26) is placed, and that by means of a brake and transmission means (17) equipped brake assembly (14), the linear velocity component of

Stroke tube (15) is adjustable at least when the drive motor is switched off, characterized in that the spindle nut (13) is in operative connection with the brake assembly (14) that in the adjustment of the lifting tube (15) with the drive motor, the spindle nut (13) frictionally with the Brake assembly (14) is in a drive function and is arranged non-rotatably by housing parts of the linear drive (10), and that at least when the drive motor from the brake assembly (14) on the spindle nut (13) acting force is regulated such reduced, so that the spindle nut (13) is rotatable, and that the linear speed component of the lifting tube (15) by the of the brake assembly (14) on the

Spindle nut (13) transmitted braking force can be influenced.

2. Electromotive linear drive according to claim 1, characterized in that the lifting tube (15) is arranged non-rotatably, and that the Spindelmut- ter (13) by means of a fixedly inserted into the lifting tube (15) bearing element

(25) is rotatably mounted.

3. Electromotive linear drive according to claim 1, characterized in that the lifting tube (15) is fixedly connected to the spindle nut (13), and that the lifting tube (15) is rotatably mounted with its free end portion in the connecting part (26).

4. Electromotive linear drive according to claim 2 or 3, characterized in that the bearing element is designed as a made of a sliding bearing material bearing bushing (25), as an axial sliding bearing or as a roller bearing.

5. Electromotive linear drive according to claim 1, characterized in that the spindle nut (13) is rotatably guided by a housing part, wherein the housing part is rotatably supported within the housing relative to the housing of the electromotive linear drive (10).

6. Electromotive linear drive according to claim 1, characterized in that the braking and transmission means of the brake assembly (14) from at least one wrap spring (17), a multi-disc clutch, a cone brake, a disc brake, a shoe brake or the like is formed.

7. Electromotive linear drive according to claim 1, characterized in that the brake assembly (14) consists of at least one rotatably mounted on the spindle nut (13) bushing (16), at least one bushing (16) surrounding the braking and transmission means (17). and an externally operable handle (27), wherein an end portion or a central region of the braking and transmission means or the wrap spring (17) with the handle (27) is in operative connection or stand.

8. Electromotive linear drive according to claim 1, characterized in that the spindle nut (13) is rotatably guided by a guide member, wherein the guide member is rotatably mounted relative to the housing of the electromotive linear drive (10).

9. Electromotive linear drive according to claim 7, characterized in that the wrap spring (17) consists of at least two helically curved portions (17a, 17b) with several turns, and that the sections (17a, 17b) by a central web (36) connected to each other are, which deviates from the helical shape and preferably parallel and spaced from the central longitudinal axis of the wrap spring (17).

10. Electromotive linear drive according to one or more of the preceding claims 7 to 9, characterized in that all sections of the braking and transmission means or all sections (17a, 17b) of the wrap spring (17) are actuated together or successively, so that the Braking effect can be controlled together or in sequence in a specific order.

11. Electromotive linear drive according to claim 7, characterized in that the handle (27) has a switching rod (28) whose central longitudinal axis parallel and at a distance from the central longitudinal axis of the spindle (11) and whose axis of rotation is offset from its central longitudinal axis.

12. Electromotive linear drive according to claim 11, characterized marked, that the switching rod (28) is designed as a profile bar, which has at least one longitudinal edge region a circular arc-shaped outer contour and on at least one side a central constriction.

13. Electromotive linear drive according to claim 12, characterized marked, that the shift rod (28) is rotatably mounted with its circular arc-shaped outer contour in a guide webs (29, 30) of the housing or attached to the housing flange tube (12) guide channel.

14. Electromotive linear drive according to claim 12 or 13, character- ized in that the semicircular outer contour of the shift rod (28) facing away from the wrap spring (17).

15. Electromotive linear drive according to one of the preceding claims 11 to 14, characterized in that the switching rod (28) extends substantially over the region of the spindle (11).

16. Electromotive linear drive according to one of the preceding claims 11 to 14, characterized in that the switching rod (28) has an annular cross-section or a circular cross-section portion, the circle center along or parallel to the central longitudinal axis of the spindle (11), so that to reduce the on the spindle nut (13) acting force the shift rod (28) is rotated about an axis of rotation o- along an axis is displaceable, or that the shift rod (28) is rotatable and displaceable.

17. Electromotive linear drive according to one of the preceding claims 11 to 14, characterized in that the switching rod (28) consists of a plurality of rods which are movable both about an axis and in an axis relative to each other, so that a movement relative to the Housing of the electromotive linear drive (10) is durchfuhrbar.

18. Electromotive linear drive according to one of the preceding claims 11 to 17, characterized in that the shift rod (28) is designed as a shift linkage, and that the shift rod (28) or the shift linkage by a rigid, such as a rigid and / or torsionally rigid

Element and also has a flexible strand which is flexible at least in one degree of freedom.

19. Electromotive linear drive according to claim 1, characterized in that the spindle nut (13) in the central region has a guide flange (21) that on both sides of this guide flange (21) in diameter smaller held projections (22, 23) are provided that at least a projection (22, 23) a sleeve (16, 24) are mounted rotationally fixed, that at least one bushing (16) of the braking and transmitting means (17) is surrounded, and the other socket (24) in the bearing element (25) is stored.

20. An electromotive linear drive according to claim 19, characterized in that the sleeve surrounding the brake and transmission means (17) with switching cam (19) faces the drive unit, and that the bushes (16, 24) are made of a metallic material, preferably made of steel.

21. Electromotive linear drive according to one or more of the preceding claims 1 to 20, characterized in that one of the brake and transmission means or the wrap spring (17) surrounded bushing with a NEN switching cam (19) for actuating the end positions of the spindle nut (13) determining limit switches (20) is provided.

22. Electromotive linear drive according to claim 21, characterized in that the socket with switching cam (19) in the longitudinal direction of the spindle (11) extending webs extending in longitudinal grooves of the housing, a housing portion, a guide member or a Flanschrohres (12).

23. Electromotive linear drive according to claim 21 and / or 22, characterized in that the switching cam (19) or the switching cams and in the longitudinal direction of the spindle (11) extending webs are rotatably connected to the spindle nut (13), and that the Braking and transmission means or the wrap spring (17) with a housing portion, a guide member or a flange (12) in such a compound that at a ner the force applied by the braking and transmission means (17) applied force the adjustment speed of the connected Component is changeable.

24. Electromotive linear drive according to claim 23, characterized marked, that the housing section, the guide member or the flange tube (12) relative to the housing of the linear drive (10) is rotatably mounted.

25. Electromotive linear drive according to one or more of the preceding claims 1 to 24, characterized in that on the spindle on the mother (13) patch, with the braking and transmission means or the

The wrap spring (17) is operatively connected to a bushing (18) rotatable by the shift rod (28) and in which an end region or a middle region of the brake and transmission means or the wrap spring (17) is fixed.

26. Electromotive linear drive according to one of the preceding claims

21 to 25, characterized in that the bushing with the switching cam (19) further in the longitudinal direction of the spindle (11) extending webs, which are guided in longitudinal grooves of the flange tube (12).

27. Electromotive linear drive according to claim 26, characterized in that the first end or a central region of the wrap spring (17) is fixedly connected to the switching cam (19) of the socket.

28. Electromotive linear drive according to one or more of the preceding claims 1 to 27, characterized in that in a free space between the outer flange tube (12) and the lifting tube (15) a holding rail (31) is arranged to the holder of a linear potentiometer (32).

29. Electromotive linear drive according to one or more of the preceding claims 1 to 21, characterized in that the brake assembly (14) one or more wrap springs (17), which are arranged in a row and whose mutually facing Stirnendbereiche are coupled together.

30. Electromotive linear drive according to one or more of the preceding claims 1 to 29, characterized in that the electromotive linear drive (10) is laid out as a furniture drive, preferably as a single drive.

31. Electromotive linear drive according to one or more of the preceding claims 1 to 30, characterized in that at least at the abutting edges of the housing parts of the linear drive (10) sealing elements are provided hen, and that at least parts of the outer skin of the linear drive (10) are formed corrosion resistant ,

32. Electromotive linear drive according to one or more of the preceding claims 1 to 31, characterized in that the electric motor-see linear drive (10) has a housing portion for receiving the spindle nut (13) and also substantially the spindle (11), and that this Housing section is designed as a flange tube (12).

33. Electromotive linear drive according to claim 32, characterized marked, that the flange as a tube (12) formed housing portion fixed to the

Housing of the linear drive (10) is connected or that between the flange tube (12) and the housing an element in the form of a flange or an adapter is arranged, wherein the flange tube (12) is fixedly connected to the flange, and that from the flange and the flange tube (12) formed unit is releasably connected to the housing such that in different angular positions, this unit can be fixed to the housing.

34. Electromotive linear drive according to one or more of the preceding claims 1 to 33, characterized in that one end of the braking and transmission means or the wrap spring (17) is fixedly connected to a further ring having a switching cam (19) and in the longitudinal direction of the spindle (11) extending webs, which are guided in longitudinal grooves of the Flanschrohres (12), and that in the Flanschrohr (12) limit switches (20) are installed for the end of the electric motor in the respective end position, and that the limit switches (20) by switching cam (19) are actuated.

35. Electromotive linear drive according to claim 1, characterized in that the lifting tube (15) in the connecting region with the spindle nut (13) has an internal thread (46) which is in engagement with an external thread of the spindle nut (13).

36. Electromotive linear drive according to claim 35, characterized in that on the lifting tube (15) in the associated region of the spindle nut (13) a support sleeve (37) is placed, which has an inwardly directed, annular projection (45), and that the Spindle nut (13), the lifting tube (15) and the support sleeve (37) mutually aligned recesses in the form-locking connection of these components connecting elements or connecting portions, such as keyways (42) engage or attack.

37. Electromotive linear drive according to claim 35, characterized in that the lifting tube (15) in the associated region of the spindle nut (13) has a larger outer diameter relative to the remaining region.

38. Electromotive linear drive according to one or more of the preceding claims 35 to 37, characterized in that the lifting tube (15) and the carrier sleeve (37) form-fitting, for example, by threaded or deformation sections are positively connected to each other.

39. Electromotive linear drive according to one or more of the preceding claims 35 to 38, characterized in that on the carrier sleeve (37) one or more wrap springs (17) are placed, the inner diameter in the unassembled state are smaller than in the mounted state, so that each inner circumferential surface of a wrap spring (17) can be frictionally engaged directly with the carrier sleeve (37).

40. Electromotive linear drive according to one or more of the preceding claims 35 to 39, characterized in that at least one wrap spring (17) is associated with a bushing (16) and / or a support ring (44), which between an inner circumferential surface of the wrap spring (17 ) And an outer circumferential surface of the support sleeve (37) is arranged.

41. Electromotive linear drive according to claim 40, characterized in that the bushing (16) by connecting elements, for example by feather keys (42) with the support sleeve (37) and / or with the lifting tube (15) and / or with the spindle nut (13). connected is.

42. Electromotive linear drive according to claim 40 or 41, characterized in that the support ring (44) is provided with a longitudinal slot and is so loosely between the formed of the stages approach or discs that a frictional force of the associated wrap spring (17) on the Carrier sleeve (37) is transferable and / or that by a frictional torque from the associated wrap spring (17) on the spindle nut (13) is transferable Ü.

43. Electromotive linear drive according to one or more of the preceding claims 35 to 42, characterized in that on the drive arrangement in the region of the connecting elements or the connecting portions, such as the feather keys (42) a bearing ring (43) is placed, which has an angular cross section, being on the inner lateral surface Recesses are formed, which engage over the connecting elements or the connecting portions (42).

44. Electromotive linear drive according to one or more of the preceding claims 35 to 43, characterized in that on the front side of

Bearing ring with the smaller diameter, a disc (40) is attached, so that an outwardly open annular groove is formed.

45. Electromotive linear drive according to claim 44, characterized marked, that in the annular groove an approach of the guide flange (21) engages such that it is rotatably mounted in the annular groove, but secured against axial displacement.

46. Electromotive linear drive according to one or more of the preceding claims 35 to 45, characterized in that one end of each

Wrap (17) is angled and engages in a corresponding recess of the guide flange (21) and that the second end of each wrap spring (17) with a switching ring (18) is in operative connection.

47. Electromotive linear drive according to claim 46, characterized in that each switching ring (18) relative to the guide flange (21) is rotatably mounted such that upon rotation of a switching ring (18) of the diameter of the respective switching ring (18) associated wrap ( 17) is changeable.

48. Electromotive linear drive according to one or more of the preceding claims 35 to 47, characterized in that the carrier sleeve (37) has a stepped outer contour and that on the annular surface formed by the steps of the switching ring (18), the support ring (44) Disc (40) and the sleeve (16) are supported in the axial direction, so that they against a

Shift at least in this direction are secured.

49. Electromotive linear drive according to claim 48, characterized in that further securing elements, for example in the form of a (41) engage in a groove of the carrier element (37) and that at least the bush (16) and / or the switching ring (18) is secured against axial displacement, wherein optionally the retaining ring (41) is associated with a disc (40).

50. Electromotive linear drive according to one or more of the preceding claims 35 to 49, characterized in that the guide flange (21) has a switching cam (19) through which a limit switch can be actuated, so that in an end position range of the current flow of an electric motor drive unit is switchable.

51. Electromotive linear drive according to one or more of the preceding claims 35 to 50, characterized in that on the guide flange (21) webs are formed, which engage in longitudinal grooves of the flange tube (12) slidably.

52. Electromotive linear drive according to one or more of the preceding claims 35 to 51, characterized in that the end, the spindle nut (13) facing away from the carrier sleeve has a stepped bore into which an additional nut (38) is inserted, or that the additional nut ( 38) inserted into the lifting tube (15) or that the additional nut (38) is coupled to the spindle nut (13).

53. Electromotive linear drive according to claim 52, characterized marked, that the additional nut (38) is circumferentially provided with a circumferential groove into which a retaining element (39) is used to connect the auxiliary nut (38) with the support sleeve (37).

54. Electromotive linear drive according to claim 53, characterized marked, that the holding element (39) is elastic, and preferably consists of an O-ring.