DE8531110U1 - Gearbox for converting a rotary into a translatory movement - Google Patents

Description

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I I t I

Description

The invention relates to a transmission having the features of the preamble of claim 1.

A gear of this type is described in German utility model 84 15 934, in which both thrust and tensile forces can be transmitted in a form-fitting manner due to the meshing of the two strands. The connection of the sections arranged one behind the other in a row per strand is only intended to guide them and not to transmit force. Various examples of such a connection are given; hinge axes guided by correspondingly adjacent, overlapping sections of the sections/articulated connections between the sections without independent axes in the form of so-called snap hinges or by gluing them onto a band that runs along the strand and is opposite the toothed side of the sections. It is also known - DE-AS 21 62 983 - to attach the sections to a flexible steel band using riveted connections.

These connections are complicated and expensive; if you look at them from the point of view of a certain tensile load, they prove to be disadvantageous:

While in the case of compressive loads the forces practically run along a straight vector laid over the gear teeth, in the case of tensile loads the forces under shear stress on the gear teeth must be guided through the body of the sections, which lies outside the gear teeth. Due to the constant play between the gear engagements of the sections, tensile loads on the connection between the sections are more or less unavoidable depending on the design of this connection. In the case of sections arranged in an appropriately overlapping manner

A corresponding bearing load occurs on the axes guided by the sections, the snap hinges give way accordingly and the connection via bands running through the longitudinal direction of the strand has the disadvantage that the tensile forces introduced via the worm thread formation in the engagement area between the sections have a relatively large lever arm to the bands, so that the sections tend to move transversely to the guide in this area under a correspondingly high torque, which results in a correspondingly high friction load in this guide area.

The invention is based on the object of simplifying the connection between the sections of each of the two strands in terms of manufacturing technology and at the same time designing it in such a way that the tensile force transmission is improved in terms of magnitude and frictional resistance.

Starting from a transmission with the features of the preamble of claim 1, this object is achieved according to the invention by its characterizing features.

According to the invention, the sections arranged in series of each of the two strands are connected to one another with the aid of a highly flexible and highly tensile-resistant, length-stable structure, such as a wire rope, which is arranged continuously in the strand direction and which is passed through the bodies of the sections. If the sections are made of metal, for example, a corresponding elongated hole would have to be provided through which the wire rope is passed and fixed to the sections with the aid of a solder. In a particularly preferred embodiment, however, the sections are made of a plastic.

which is pressed, injected or cast around the ropes. This results in a much simpler, cost-saving production and also creates the possibility of the connecting structure, especially the wire rope, in the vicinity of the thread.

formation and/or the gearing, so that on the one hand the lever arm between the force-introducing attack of the worm on the thread formation and the connection formed is reduced and on the other hand the shear load between the gearing engagements can be reduced when the sections are subjected to tensile load. This makes it possible to match the tensile load capacity of the gear to that of the shear load capacity without the material strength, which is sufficient for the maximum pressure load, having to be made correspondingly higher for a correspondingly high tensile load and thus shear force introduction into the teeth of the gearing.

The connection between the sections according to the invention can be limited to a connecting structure or a wire rope, which does not necessarily have to be arranged symmetrically to the body of the sections when viewed transversely to the guide direction. Two wire ropes can also be arranged in parallel per strand, which can then be arranged in a spatially advantageous manner in the two corner areas between the thread formations, the teeth and the guide surfaces of the sections that engage the guide.

Advantageous embodiments of the invention emerge from the subclaims in connection with the embodiment shown in the drawing, to which particular reference is made and whose following description explains the invention in more detail.

Show it:

Fig. 1 a principle cross-sectional view of the
transmission;

Fig. 2 a cross-sectional view in the area of
Guide;

a» at &bgr; ■* · · ·

Figure 3 shows an embodiment of the connection of the sections of a strand of the motion transmission device with two parallel wire ropes.

Figure 1 shows a drive motor 1, the output shaft 11 of which ends in a worm 4 via a coupling, which is schematically indicated at 3. This worm engages in a corresponding screw thread, half of which engages in sections 14 of two strands 7 and 8 of a motion transmission element, designated overall by 5. This motion transmission element 5 is guided in a straight line in a guide 6, shown broken off. The strands 7 and 8 of the motion transmission element 5 are inevitably brought together by guide surfaces before the engagement area with the worm 4. The strand 7 is stored in a drum at 18, the strand 8 is - here for demonstration purposes accommodated in a storage unit parallel to the guide 6.

The sections 14 of each strand 7 or 8 of the motion transmission member 5 are provided with a toothing 9 on the surfaces facing each other, which is shown in a trapezoidal shape in the exemplary embodiment. However, this toothing 9 is selected, for example, such that the positive engagement with regard to the force transmission in the direction of the guide 6 practically does not generate any force component running transversely to the longitudinal direction of the guide. This can be achieved easily with an involute toothing or the like.

The guide 6 has a longitudinal slot 12 through which a drag link or the like is guided, which forms the connection between the end of the motion transmission link 5 facing away from the drive motor and a

Direction of the guide 6 produces an object to be taken along, in particular a single-leaf overhead door leaf.

In the area of the screw 4 or its end facing the motor shaft 11, the strands 7 and 8 of the moving member 5 are guided and stored away from each other. In this way, a space-saving arrangement of the entire drive device is achieved.

Due to the high reduction ratio between the worm 4 and the screw thread 10 adapted to the worm, half of which is located in sections 14 of the strand 7 and half in those of the strand 8 of the motion transmission element 5, an additional reduction gear is not required. This drive device is therefore particularly inexpensive to manufacture. In addition, there is the advantage that resistance that occurs when an obstacle occurs in the path of movement of the object moved by the motion element 5 results in an additional axial load on the worm and thus on the motor shaft 11, which can be used to switch the direction of rotation of the drive motor 1 off or on, for example, by the motor itself being mounted so that it can be displaced against an elastic resistance.

It is readily understandable that, due to the toothing 9, via which the sections 14 of the strands 7 and 8 of the motion transmission device ? mesh, a tensile and compressive load can be transmitted. As the drawing shows, the sections 14 of the strands 7 and 8 are arranged offset from one another in such a way that a section 14 of, for example, the strand 7 bridges two adjacent sections 14 of the strand 8. This ensures that tensile and compressive forces are transmitted in a form-fitting manner via the toothing of the sections 14.

Figures 2 and 3 show - omitted in Figure 1 - an example of the special type of connection of the sections 14 provided in each of the strands 7 and 8 of the motion transmission device 5. Within each of the sections of a strand 7 or 8, two wire ropes 19 and 20 are arranged, running parallel in the longitudinal direction of the strand, which are embedded in the body of the sections 14 outside the toothing 9 and the thread formation 10, preferably in the vicinity of the toothing 9 and the thread formation 10, in order to be able to absorb the tensile forces introduced via the thread formation 10 by the worm 4 or the drive motor 1 with a small lever arm, on the one hand, and to transmit the forces introduced into the body of the sections 14 via the toothing 9 when tensile. The length-stable tensile load capacity of the wire ropes In particular, a play-related load on the toothing 9 in the direction of pull is absorbed, or the tensile force introduced via the toothing 9 is offered a particularly resistant path in the body area of the sections 14, so that the material properties of the sections 14 can be measured according to the load when transmitting compressive forces, while the shear stress on the toothing teeth is reduced.

In principle, a single wire rope per strand 7 or 8 can be sufficient, which should then preferably be arranged in the area between the thread formation 10 and the guide surface of the sections 14 opposite the toothing 9. In the embodiment shown, two parallel wire ropes 19 and 20 are provided, each of which runs in one of the corner areas of the sections 14, which are formed between the thread formation 10, the guide 6 and the toothing 9, as illustrated in Figure 2.

Here, the wire ropes 19 and 20 are located in a material surplus area of the sections 14 and at the same time in the vicinity of the thread formation 10 to reduce the tilting moment exerted on the sections 14 by the introduction of force at 10 and in the vicinity of the toothing 9 to absorb tensile loads introduced into the body of the sections 14 via the toothing.

In this way, the sections are relieved of the tensile load on their material, the wire rods form a reinforcing insert for the sections 14, which is practically only effective under tensile load/ the magnitude of the torque exerted on the sections 14 by the screw 4 with regard to the connection and thus the frictional force between the sections 14 and the guide 6 is reduced.

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Claims (8)

&bull;1 ■ Dipl.-Ing. Otto Flügel, Dipl.-Ing. Manfred Säger, patent attorneys, Cosimastr. 81, D-8 Munich 81 Hörmann KG Drive and control technology
Remser Brook Il
4834 Harsewinkel 12.882/fl/km GEARBOX FOR TRANSFERRING A ROTARY
IN A TRANSLATORY MOVEMENT EXPECTATIONS 1. Gear for converting a rotary movement into a traversing movement, preferably connected to an electric drive motor unit, in particular for opening and closing a door or gate, for example a garage door with an overhead movable door leaf, with a rotary drive and a movement transmission member which is held in a translationally movable manner and which is connected to the drive in the area of a guide via a threaded connection and, viewed in the direction of movement, is designed to be longitudinally divided into at least two strands, which are guided separately at one end outside the guide so as to be deformable transversely to the guide direction and are held together at the other end so as to prevent them from moving away from one another laterally, and each of which consists of a series of sections arranged one behind the other and connected to one another via a connecting element which is continuous in the longitudinal direction of the strand and is deformable transversely to the guide direction, each of which bridges two adjacent sections of the respective opposite strand, the sections of the strands engaging with one another via a toothing in such a way that each section of one strand engages with each of the opposite sections of the other strand in the when brought together , engages in a form-fitting manner in the direction of tension and compression, characterized net that the connecting element is designed in the form of at least one wire rope (19, 20) or similar highly flexible and tensile-loadable, length-stable structure, which is passed through the sections (14) and to which the sections (14) are fixed by engagement with the rope sheath surface. 2. Gear according to claim 1, characterized in that the wire rope (19, 20) is arranged in the vicinity of the thread formation (10) of the sections (14) provided for the force-introducing engagement of a slag (4). 3. Transmission according to claim 1 or 2, characterized in that the wire rope (19, 20) is arranged in the vicinity of the toothing (9) of the sections (14). 4. Gear according to one of claims 1 to 3, characterized in that two wire cables (19, 20) are provided in parallel per strand (7, 8), each of which is arranged in one of the corner regions of the sections (14) located between the guide (6) and the thread formation (λθ) (Fig. 2). 5. Gear according to claim 4, characterized in that each of the two wire cables (19, 20) provided for each strand (7, 8) is arranged symmetrically distributed in the vicinity of the thread formation (10) and the toothing (9). 6. Gear according to one of claims 1 to 5, characterized in that the sections (14) consist of plastic and are formed, in particular pressed, injected or cast, around the wire rope or ropes (19/20) of the associated strand (7, 8). 7. Transmission according to one of claims 1 to 6, characterized in that the wire cable or cables (19/20) are formed with raised protruding spiral structures on the surface. 8. Gearbox according to one of claims 1 to 7, characterized in that the wire rope or ropes (19/20) of both strands (7, 8) are connected to a connecting member which is arranged at the working end .