EP0736151A1

EP0736151A1 - System for a friction gear

Info

Publication number: EP0736151A1
Application number: EP94928285A
Authority: EP
Inventors: Michael Hörmann
Original assignee: Marantec Antriebs und Steuerungstechnik GmbH and Co KG
Current assignee: Marantec Antriebs und Steuerungstechnik GmbH and Co KG
Priority date: 1993-10-01
Filing date: 1994-10-04
Publication date: 1996-10-09
Also published as: DE9415948U1; WO1995009993A1; JPH09503278A; CA2173242A1

Abstract

The invention concerns a friction drive for a transmission belt, the friction drive having a frictional roller (1) and a device (2, 3) for the control of the transmission belt (4) at a large angle of contact using two deflection elements (2, 3). In order to ensure low-slip operation whatever the required load, the friction drive experiences an increased frictional force between the transmission belt (4) and the frictional roller (1) by virtue of the fact that the deflection elements which guide the transmission belt round the frictional roller with a large angle of contact execute a motion relative to the frictional roller under the tensile strain which occurs in the working strand of the transmission belt, this motion increasing the contact surface and, in particular, the contact pressure between the transmission belt and the frictional roller.

Description

Device for a friction gear

The invention relates to a friction drive for a rope or belt-shaped drive train with a friction roller, preferably driven by an electric motor, and with a guide device for guiding the drive train with a large wrap angle - in particular greater than 180 ° - around the wrap circumference zone by means of two deflection elements, whose guide surfaces guiding the drive train are arranged facing away from the looped circumference of the friction roller in the direction of the striving strands of the drive train, and with a reversing device deflecting the drive train at its end region facing away from the driven friction roller.

Friction drive, i.e. the transfer of forces via friction, seen here in contrast to positive locking, is a fundamentally known concern. It is also known that a large wrap angle between the driving friction roller and the driven drive train is favorable for the transmission of forces that is as slip-free as possible.

Based on this consideration, the object of the invention is to create a drive with a driven drive train that works as slip-free as possible and in particular is able to transmit a back and forth movement via a strand, such as that used to actuate Garage doors between closing and opening movement is required. there The run of the drive train referred to can be coupled to a connecting member which in turn is connected to the door leaf to be moved, in particular via a joint. The door leaf can have one or more parts, in particular can be moved overhead, or can also be designed to be carried along in the horizontal plane between the closing and opening movements.

Frictional cable drives are known in principle, also in the sense of the above application. It is always problematic to transfer the movement quantity of the driving roller to the movement quantity of the drive train with as little loss as possible.

From DE-PS 325667 (FIG. 2 relating to the prior art) it is already known to design the wrap angle of a driving friction roller to be large in that the friction roller in the sense of the outgoing dreams of a drive train to be driven with regard to the resulting driving forces oppositely directed deflection elements are provided. It is also known - DE-PS 344 096 - to take measures in order to put the drive train under a certain tension with regard to the drive unit and the deflection device. This is to ensure the required normal force between the strand and the driving or driven roller element for the low-slip transmission of movements over a strand of the type in question.

According to the invention, the problem is solved in such a way that at least one of the deflection elements is guided to be displaceable on the friction roller in one of the strands of the drive train under tension.

Accordingly, it is not only the arrangement of the deflection elements in the sense of a large wrap angle of the friction roller, but also the tensile stress in one of the strands of the drive train is used for the wrap angle and / or the contact pressure of the drive train on the friction roll to increase.

This idea assumes that the drive train is guided encompasses a translatory space, ie the drive force applied to the drive train via the friction roller is passed on to a translationally distant location. In the sense of a back and forth door leaf movement, for example, this force is transmitted along a translational path. Another idea is to convert the force transmitted to the drive train into a rotary one, for example by connecting the drive train at its end region facing away from the drive roller to a friction roller, which in this case is to be regarded as an output, for example Transmission of drive forces from a drive motor unit to a shaft to which the door leaf is connected in particular via a cable connection and / or with a weight compensation device connected in parallel.

The drive train designed as a rope or belt is preferably under tension, so that the normal force on the wrapping surface of the friction roller is as high as possible. Such a pretension can in principle be achieved in that components involved in the drive train guide are appropriately pretensioned, which relates in particular to the friction roller itself and / or the deflection roller arranged opposite it in the longitudinal direction of the strand. However, it is also possible to arrange or store the deflection elements in a prestressed, spring-loaded manner. Another possibility is to arrange the rollers and deflection elements practically rigid and to ensure the tensile stress in the drive train through its inherent elasticity with appropriate arrangement.

In a further particularly preferred embodiment, it is ensured that the deflection elements can be displaced relative to the driving friction roller in such a way that the associated deflection element moves towards the circumference or the jacket wall of the driving friction roller under tensile load on a strand, so that the drive train insofar as it is exposed to a pressure load between the deflection element and the friction roller. This ensures the degree of wrap between the drive train and the friction roller and additionally provides a contact pressure in the sense of increasing the normal force component for the transmission of the friction force. This under load of the "Pressing component" taking place in the drive train can be ensured by various measures, for example, by a possibility of displacing the drive train running in the direction of the strands of the drive train straying from the deflecting elements, approximately perpendicular to its axis of rotation or by an in the aforementioned sense under the forces acting on the drive train on the axis of rotation of the drive roller for directed movement of the respective deflection element concerned, in particular such that both deflection elements are mounted about a pivot axis running parallel to the axis of rotation of the friction roller. This pivot axis can run coaxially with the axis of the friction roller.

In principle, it would be possible to design the drive train in an open-ended manner. However, an endless formation is preferably provided.

Similar to the friction roller, the deflection elements can be designed as a rotary body, that is to say rollers. However, this is not necessary because sliding guidance on appropriately shaped guide surfaces of the deflection elements is also possible. In this context, the surface structuring of the friction roller and the deflection elements can be specifically designed so that the forces to be transmitted from the drive roller to the drive train occur with the highest possible coefficient of friction, while those friction coefficients occurring between the drive train and deflection elements are kept as low as possible. Such a design can be achieved, for example, in the form of a rubber-like surface structuring of the friction roller and the hardest and smoothest possible design of the guide surfaces of the deflection elements.

The sketch shows a friction wheel drive with a spring-loaded deflection roller and a driven center roller, to which two deflection elements, in the form of rollers or solid bars with a smooth surface, are assigned in such a way that a large angle of wrap around the drive roller is achieved, as can be seen in the drawing . The "deflection roller" at the end of the endless belt loop that is translationally facing away from the drive roller can also be fixed the body should be formed. A normal force component required for the transmission of the frictional force between the drive train and the outer surface of the drive roller can itself result from an elastic tension of the rope or belt-shaped strand itself, but one can also by corresponding spring loaded, displaceable mounting in the area of the drive roller, the deflection roller and / or exert forces corresponding to the deflection elements on the drive train.

In a preferred embodiment, the two deflection elements can be connected to one another and designed to be displaceable approximately in the longitudinal direction of the drive train. If a load occurs in one of the strands, the drive train tries to move the next adjacent deflecting body in such a way that it runs along the circumference of the drive roller over a distance, and thereby through a normal component onto the drive roller or the type located in between ¬ drivetrain acts. This results in an increased extrusion. The other deflecting body is taken along accordingly when stored together and thus ensures that the angle of wrap around the drive jacket surface of the drive roller is maintained overall.

Instead of the above-described storage of the deflection bodies, the axis of the drive roller can also be mounted in a floating manner in the longitudinal direction of the drive train, because then a tensile stress occurring in the strand presses the driven roller against the deflection bodies, with a similar effect as described.

As a drive, a small, high-speed drive motor can be operated directly on a worm gear arranged coaxially to the friction wheel via a worm drive. In principle, however, the application of the drive rotation movement is optional.

As already mentioned, the movement of the drive train can be exploited, in particular in the area of a straight, longitudinally running strand, for the reciprocating movement of a carriage, to which, for example, a door leaf is attached. is closed. However, the transmission of a rotational movement from one shaft to another can also be provided. As an example of this, reference is made to the transmission of motion from a drive motor to a shaft to which a door leaf is connected, for example via cable drums arranged on the shaft, which carry a rope engaging the door leaf. In order to keep the reaction torque to the drive or the drive motor small, it is expedient to keep the distance between the output axis of the motor or here the axis of rotation of the friction roller on the one hand and the shaft for the movement of the door leaf on the other hand large. For this reason, a corresponding transmission path for the driving force will be provided, which, given the above considerations, is expediently carried out via an endless drive train. In this case, the driven part, which is to be driven away from the drive roller, is spaced correspondingly far apart and is designed similarly with regard to the transmission of frictional force via the drive train, as is the case in the area of the drive roller, ie also in the area of an driven friction roller connected to the aforementioned shaft two deflecting bodies are provided which ensure the intended large wrap angle and the normal force required for the transmission of the output force by means of normal force required by friction.

In the context of the above-mentioned drive and / or drive design, a "coupling" can be realized in a simple and elegant manner by designing the or one of the deflecting bodies or, of course, the drive roller or the drive roller so that they can be displaced such that simple displacement movement transversely to the respective deflection axis, whatever the voltage generated in the drive train is rendered ineffective, so that the train moves slidably with respect to the drive and / or driven roller without any significant power transmission.

In the case of a load-dependent relative movement between the drive roller and deflection body, a "crowning" can be provided for guiding the strand, but in the circumferential region of the guide body facing away from the drive roller because the pressure effect between the guide body and drive roller is as large as possible should be designed. Another possibility of guiding the drive train is in the area of the drive roller and / or the deflection body. or the deflecting roller or driven roller, to be provided on the side of the strand, protruding disks or the like.

It is particularly important that the respective deflection element leads to an increase in the system according to pressure and / or area of the drive train to the circumference of the friction roller under tensile stress, so that the product of normal force and friction factor increases with increasing force transmission torque. For this purpose, at least one of the deflecting elements can be displaced under the tension of the drive train in such a way that the abutment on the friction roller is improved in a frictionally locking manner in the sense of the above parameters.

The invention is explained in more detail below on the basis of the exemplary embodiments which can be seen from the accompanying drawings, preferred embodiments result - particularly with reference to these drawings - formulated subclaims.

Show it:

Figure 1 is a schematic plan view of a friction drive;

Figure 2 shows a preferred embodiment of the friction roller;

3 a b c functional diagrams of the drive according to FIG. 1 under load;

FIG. 4 shows a basic diagram of a support for deflection elements;

Figure 5 shows the embodiment of Figure 3 to illustrate derivable signals; Figure 6 shows a preferred embodiment of the friction roller;

Figure 7 and 8 side view and top view of a practical schematic embodiment of the drive in use on a door drive.

In Figure 1, the drive roller 1 is driven by an electric motor in a manner not shown. The deflecting elements 2 and 3, which are designed as sliding bodies in the exemplary embodiment shown, are arranged with their resultant drive train 4 - here presupposed here in principle as a broadband-shaped belt - receiving supporting surfaces of the resulting receiving surface of the friction roller 1, such that the wrap angle of the according to the drawing around the deflection elements and the friction roller driven drive train 4 is well over 180 °. This ensures a largely slip-free circumferential transmission force from the friction roller 1 to the drive train 4. As can be seen, the wrapped circumference 10 of the friction roller by means of the deflection elements 2, 3 by means of their guide surfaces 8, 9 is correspondingly large.

The striving strands 11 and 12 of the drive train 4 can - as shown in FIG. 1 - be deflected by means of roller-shaped conversion rollers 20 and 21 in order, for example, to be able to operate a translatory drive shown in FIGS. 7 and 8.

FIG. 2 is intended to represent a preferred embodiment of the friction roller 1 as a sectional view along the line II-II in FIG. 1, specifically in connection with FIG. 6, such that the circumference of the friction roller is formed by a particularly friction-resistant covering, and indeed in connection with the belt-shaped or belt-shaped drive train used here and its structure. Such a circumferential covering 19 of the friction roller 1 is in turn connected as conclusively as possible to the base body of the friction roller 1, for example via a polygonal circumferential configuration, as can be seen from FIG. 6.

FIG. 3 shows several tensile forces in the two runs 11 and 12 of the drive train 4 of different types, evident effects on a carrier 13, the conforming or contact conditions' between the drive train 4 and the friction roller 1 due to the deflection elements 2 and 3, which are mounted on a carrier 13, which acts on the tensile force in the drive train 4 reacted by a change of position.

A tensile force in one of the strands 11, 12 of the drive train can be used to use the deflection elements 2, 3 or at least one of these to change the position of the friction roller 1, namely in the direction of a radial reduction in distance. For this reason, a displaceability between the deflection element and the friction roller, which is formed approximately in the direction of the strand, is fundamentally useful. With regard to force-transmitting actuations of the drive train by the friction roller both in one and in the other direction of movement, it is advisable to arrange the deflecting elements, which in principle can each be displaceably supported, on a common carrier. An approximately linear displaceability of the carrier can be provided approximately perpendicular to the axis of the friction roller, but in a preferred embodiment the carrier can be pivoted to the axis of the friction roller 1. This can be done by a concrete bearing axially parallel or coaxial to the axis of rotation of the friction roller, but a "floating" bearing can also be provided, which results from the fact that the drive train 4 is stretched around the friction roller 1 and the deflection elements 2 and 3 by means of a reversing device 17 facing away from the friction roller 1, exerts corresponding forces on the drive arrangement comprising the friction roller 1 and deflection elements 2 and 3, which bring about the spatial relative association between the deflection elements 2, 3 and the friction roller.

The deflecting elements could be designed as rollers, in the exemplary embodiment shown they are designed as sliding bodies which are so far fixed with regard to the conveying movement of the drive train 4. They are either fixedly or pivotably mounted on the carrier 13 and have extensions 14 in the direction of the strands 11 and 12 of the drive train 4, which accommodate the friction roller between them, as shown in FIG. 3. A tensile load on one of the strands 11 or 12 leads to a pivoting of the deflection elements 2 and 3 supporting carrier 13 about the axis of rotation of the friction roller 1 such that the wrap angle between the drive train 4 and the circumference of the friction roller 1 is maintained and, in addition, an increased normal force occurs between the drive train 4 and the friction roller 1 in the area in which the continuation 14 of the strand 11 or 12 of the drive train 4 tensioned due to the tensile load exerts pressure on the circumference of the friction roller 1 due to a pivoting movement of the carrier 13. For this purpose, reference is expressly made to the illustrated exemplary embodiments.

It can be seen that, due to the displaceability of the deflecting elements according to the invention in relation to the friction roller, dependent contact forces and thus generally higher static frictional forces can be transmitted between the drive train and the friction roller.

FIG. 4 illustrates in two views rotated by 90 ° the formation of deflection devices on a carrier which is held in its position dependent on the tensile force solely by the wrapping of the drive train between deflection elements and friction roller.

FIG. 5 illustrates that the tension-dependent pivot position of the carrier 13 of the deflection devices 2 and 3 can be damped from the outside, whereby the leg springs 23 can be coupled with a load-dependent display, for example for the reporting of resistances in the range of motion by the Drive train reciprocatingly movable object, in particular door leaf.

The views according to FIGS. 7 and 8 illustrate a practical embodiment of the friction drive on the basis of a linearly reciprocating object, for example a door leaf. In a guide rail 22, a slide-shaped driver 24 is coupled to the drive train 4, which is guided around a roller 17 as a reversing device, around converter rollers 20 and 21 to a drive unit, generally designated 25, which has a drive motor 26, the via a worm gear, not shown, on a Friction roller 1 acts. The friction roller 1 is assigned deflection elements 2 and 3 on a carrier 13 in the manner described. The dreams Jl and 12 of the drive train 4 are diverted via the conversion rollers 20, 21 into the plane of the guide rail. The reversing device designed as a roller for the drive train 4 is under the adjustable load of a spring 7, which stresses the strands of the drive train 4.

Claims

EXPECTATIONS

1. friction drive for a rope or belt-shaped drive train (4) with a - preferably electromotive - driven friction roller (1) and with a guide device (2, 3; 13) for guiding the drive train (4) with a large wrap angle - in particular greater than 180 ° - around the circumferential circumferential zone by means of two deflecting elements (2, 3), the guide surfaces (8, 9) of which guide the drive train (4) and the wrapped circumference (10) of the friction roller (1) in the direction of the striving strands (11 , 12) of the drive train (4) are arranged facing away, and with a reversing device deflecting the drive train (4) at its end region facing away from the driven friction roller (1), characterized in that at least one of the deflection elements (2, 3) under tension in one of the strands (11, 12) of the drive train (4) is displaceably guided onto the friction roller (1).

2. Friction drive according to claim 1, characterized in that both deflecting elements (2, 3) are angeord¬ net on a common support (13) which is displaceably guided relative to the friction roller (1).

3. Friction drive according to claim 1 or 2, characterized in that the deflecting elements (2, 3) or their carrier (13) approximately in the strand direction of the Drive train (4) are or is linearly displaceable.

4. Friction drive according to claim 1 or 2, characterized in that the deflecting elements (2, 3) or their carrier (13) are guided or is pivotable about an axis parallel to that of the friction roller (1).

5. Friction drive according to claim 4, characterized in that the carrier (13) for the deflecting elements (2, 3) is pivotally guided about an axis extending coaxially to the axis of rotation of the friction roller (1).

6. Friction drive according to one of claims 1 to 5, characterized in that the deflecting elements (2, 3) or their carrier (13) floating through the drive train (4) in relation to the stationary friction roller (1) leads ge are or is.

7. Friction drive according to one of claims 1 to 6, characterized in that the deflecting elements are designed as rollers rotatable about the axis parallel to the axis of rotation of the friction roller (1).

8. Friction drive according to one of claims 1 to 6, characterized in that the deflecting elements (2, 3) are designed as a fixed, on a carrier (13) formed or arranged Gleitköφer (2, 3).

9. Friction drive according to one of claims 1 to 6, characterized in that the deflecting elements (2, 3) on a support (13) are pivotally mounted.

10. Friction drive according to claim 8 or 9, characterized in that the deflecting elements (2, 3) are sliding bodies, which deviate from the approximately circular segment-shaped sliding surface in the direction of the strands (11, 12) of the drive train (4) from the sliding surface Continues (14).

11. Friction drive according to one of claims 8 to 10, characterized in that the extensions (14) of the friction roller (1) facing, adapted to the friction roller circumference curved surfaces (15).

12. Friction drive according to one of claims 8 to 11, characterized in that the strutting strands (11, 12) of the drive train (4) facing surfaces (16) are approximately flat.

13. Friction drive according to one of claims 1 to 12, characterized in that the drive train (4) is under spring tension in the strand direction, in particular by a deflection elements (2, 3) and / in the strand direction of the drive train on the friction roller (1) or the spring (7) acting on the reversing device (17).

14. Friction drive according to one of claims 1 to 13, characterized in that with belt-shaped (broadband) design of the drive train (4) least one of the drive train receiving peripheral or sliding guide surfaces of the friction roller (1), the deflection elements ( 2, 3) and / or the reversing device (7) are spherical or are formed on both sides of the receiving surfaces with side cheeks protruding beyond the receiving surface (radially).

15. Friction drive according to one of claims 1 to 14, characterized in that the reversing device is designed essentially the same as the friction rollers (1) deflecting elements (2, 3) drive design in such a way that the driven roller provided instead of the friction roller forms the transmission output element.

16. Friction drive according to one of claims 1 to 15, characterized in that the friction roller (1) is provided with a friction lining (19) which - preferably over a polygonal circumferential design of the friction roller - is brought onto the friction roller and preferably with one Cross knurled toothing is provided.

17. Friction drive according to one of claims 1 to 16, characterized in that from the friction roller (1) or the associated deflecting elements (2, 3) striving strands (11, 12) of the drive train (4) via reversing rollers (20, 21 ) are deflected in the direction of a guide rail (22).