EP3290381A1 - Compact drive assembly for an escalator or a moving walkway - Google Patents

Abstract

A drive arrangement (25) for a moving walk or an escalator (1) is described. The drive arrangement (25) has two sprockets (27) arranged parallel to one another, each with an outer toothing (29) provided on an outer circumference for driving a respective conveyor chain (3) engaging the outer toothing (29). Furthermore, the drive arrangement (25) has a motor unit (35), at least one inner toothing (49) provided on an inner circumference, which is arranged in a rotationally fixed manner relative to the outer toothing (29) of at least one of the sprockets (27) and one of the motor unit (35). to be driven pinion (47), which engages in the internal toothing (49) on. The drive arrangement (25) is, among other things, small-sized and low-wear.

Description

The present invention relates to a drive assembly for an escalator or moving walk.

Escalators and moving walkways are used to transport people, for example, in buildings between different height levels or within a constant height level. For example, escalators, which are sometimes referred to as escalators, used to transport people, for example, in a building from one floor to another floor. Moving walkways can be used to carry people, for example, within a floor in a horizontal plane or only slightly inclined plane.

Escalators and moving walkways usually have a plurality of kiting units on which e.g. People can stand and be transported by passenger transport system. On escalators, the kiting units are also referred to as stairs. For driving platforms, the kiting units are commonly referred to as pallets. The kiting units are regularly using a conveyor such. a conveyor chain or a plurality of conveyor chains connected to each other and can be displaced during normal operation of the passenger transport system, for example by means of the conveyor in a row continuously along a circulating travel path. A conveyor chain of an escalator is sometimes referred to as a step band. A conveyor chain of a moving walkway is sometimes referred to as a pallet conveyor.

The conveyor chains are regularly driven by means of specially designed drive arrangements. A drive assembly generally includes a motor unit by means of which one or more sprockets are rotated, which in turn engage at least one of the conveyor chains. The engine unit generally has a motor, usually an electric motor, and usually a transmission. The motor unit is coupled to the sprocket or the sprockets in such a way that the normally fast-rotating motor transmits its power to the sprocket wheel (s). A sprocket in this case typically has an outer toothing on an outer circumference. The outer toothing generally has a multiplicity of teeth which protrude outwardly from a sprocket body essentially radially and via which the sprocket can engage in the conveyor chain or in links of the conveyor chain. Thus, a force-transmitting connection can occur between the sprocket and the conveyor chain. Thus, by means of its motor unit, the drive assembly can slowly drive the sprocket (s) in rotation and with high torque move the conveyor chain and thus the tread units attached thereto.

A drive train in the engine unit between the engine and the driven sprocket usually includes a directly flanged to the engine worm gear and another reduction gear. This reduction gear generally comprises either a gear transmission or a sprocket gear, which is usually designed in one stage.

In the CH 612 894 is a drive unit described within the step band of escalators. In this case, a reduction gear in the form of a gear transmission is formed in a motor unit. Due to space constraints usually available in escalators or moving walkways, the gear transmission generally has to be small in size, so that it is often heavily loaded. This can jeopardize a longevity of the drive arrangement. Optionally, several gear stages may be necessary to achieve a sufficiently high for the operation of the escalator or the moving walk gear ratio. Multi-stage transmissions can require a large amount of space.

In the WO 2012/146539 A1 an escalator or a moving walkway is described in which a drive unit drives sprockets via a sprocket gear. However, since such a sprocket gear may run the risk of a drive chain tearing, official regulations such as the European standard EN115 may require that a sprocket drive gear assembly be provided with a safety brake. This in turn can complicate the structure of the drive assembly and increase system costs.

There may be, inter alia, a need for a drive assembly for an escalator or moving walkway, and a need for an escalator or moving walk equipped with such a drive arrangement in which the disadvantages set out at the outset can be at least partially avoided. In particular, there may be a need for a drive arrangement which requires little installation space, is simple in construction, as far as possible requires no additional complex safety measures, and / or can be operated reliably over long periods of time.

Such a need may be met by the subject matter of any one of the independent claims. Advantageous embodiments are defined in the dependent claims and the following description.

According to a first aspect of the invention, a drive arrangement for a moving walkway or an escalator is proposed which has two sprockets arranged parallel to one another, a motor unit and at least one pinion to be driven by the motor unit. The sprockets each have an outer toothing provided on an outer circumference for driving a respective conveyor chain engaged with the outer toothing. The drive arrangement is further equipped with at least one inner toothing provided on an inner circumference. The internal toothing is rotatably arranged relative to the outer toothing of at least one of the sprockets. The pinion to be driven by the motor unit engages in the internal toothing.

According to a second aspect of the invention, there is provided a moving walk or escalator comprising two conveyor chains, a plurality of tread units each attached to both conveyor chains, and a drive assembly according to an embodiment of the first aspect of the invention for driving the conveyor chains.

Possible features and advantages of embodiments of the invention may be considered, inter alia, and without limiting the invention, as being based on the ideas and findings described below.

Embodiments of the moving walkways or escalators described herein are designed by means of their drive arrangement to move conveyor chains in order to be able to displace conveyor units attached to the conveyor units such as steps or pallets along a travel path. The conveyor chains together with the tread units are sometimes referred to as a conveyor belt and can move in a closed ring between a supply and a return. At longitudinal ends of the travel, i. In the region of the flow and the return, deflection wheels or pulleys are provided in order to divert a direction of movement of the conveyor belt by about 180 ° can. In the area of the drive arrangement, these deflecting wheels are regularly designed as sprockets which can be driven by means of a motor unit. The sprockets can be rotated by the motor unit. Since an external toothing is provided on the outer circumference of the sprockets, which engages in suitable receptacles or recesses in the conveyor chain, the conveyor chain can be displaced together with the tread units attacking it in this way and thus the load of passengers standing on the tread units are conveyed.

In such a constellation, on the one hand, a truss receiving the conveyor belt should be as narrow as possible in order to require as little installation space as possible in a building receiving the moving walk or the escalator. On the other hand, it is usually desirable to design the kiting units as wide as possible in order to be able to carry many passengers.

Therefore, it is regularly undesirable to arrange the drive assembly laterally next to the conveyor belt, as this would either increase the width of the escalator or a possible width of the tread units would be reduced. Instead, it is preferred to accommodate the drive assembly as far as possible between the flow and the return of the conveyor belt. In this area of the escalator or the moving walk, however, only little space is regularly available for the drive arrangement. Thus, the drive assembly should on the one hand have small dimensions, on the other hand, however, can cause the necessary forces or torques on the sprockets in order to promote the loaded conveyor belt can.

These seemingly contradictory requirements can be met with a drive arrangement according to embodiments of the present invention.

In order to be able to convey the conveyor belt of the escalator or of the moving walk, the drive arrangement has two sprockets whose outer toothing arranged on the outer circumference is in engagement with the conveyor chain of the conveyor belt. The sprockets can thereby at least on its outer periphery, i. with respect to the external teeth, possibly even with respect to their entire geometry, be formed in substantially the same manner as conventional sprockets. Accordingly, no modifications to the conveyor belt and in particular to the conveyor chain need to be made.

For example, the two sprockets of the drive assembly may be identical. In particular, they may rotate about a common axis of rotation and be spaced from each other with respect to the direction of the axis of rotation. A distance between the sprockets may be equal to or slightly larger or smaller than a width of the tread units.

A basic geometry of a sprocket is substantially round, for example, with a diameter of between 20cm and 100cm, preferably between 40cm and 80cm, wherein along the outer circumference, however, radially outwardly projecting teeth are provided which form the external teeth. The teeth are designed and dimensioned such that they can engage in recesses in the conveyor chain to be conveyed by the sprocket and thus cause a form fit between the sprocket and the conveyor chain. For example, the teeth may have a tooth height between 0.5cm and 10cm, preferably between 1 and 5cm, radial length, i. measured in the radial direction. Further, the teeth may have a tooth thickness between 5cm and 50cm, preferably between 25cm and 45cm, circumferential length, i. measured in the circumferential direction of the sprocket. In addition, the teeth may have a tooth width between 0.5cm and 15cm, preferably between 1cm and 8cm, width, i. measured in the direction of the axis of rotation.

An outer contour of the sprocket of the drive assembly according to the invention thus substantially corresponds to that of a conventional sprocket. In contrast to However, a conventional sprocket is provided on an inner periphery of a further toothing. This toothing is formed as an internal toothing, ie their teeth protrude radially inwardly towards the axis of rotation of the sprocket.

As explained in more detail below, this internal toothing may be an integral part of the sprocket or in the form of additional components rotatably connected to the sprocket and thus rotatably disposed relative to the external teeth.

In contrast to conventional drive assemblies for escalators or moving walks, in which a motor unit usually drives a sprocket connected to the central axis or shaft, it is now proposed to drive at least one of the sprockets using a driven by the motor unit pinion, which cooperates with the internal teeth and over this can put the rotatably connected with her sprocket in rotation.

The motor unit can have one or more motors here. Preferably, electric motors are used, which can be physically small and powerful. The engine unit may also have a transmission. For example, one or more gear stages can be flanged to the motor unit. The transmission can cause a desired reduction and thus an increase in torque.

The pinion may have an outer toothing which is adapted in its geometry to the internal toothing on the sprocket, i. outwardly projecting teeth of the pinion can come with teeth of the internal teeth in precisely fitting engagement. The pinion is preferably significantly smaller in terms of a number of teeth and a diameter than the sprocket, for example, in particular less than a radius of the inner circumference or even smaller than half the radius of the inner circumference, along which the internal toothing is formed. The sprocket and the pinion are arranged such that they can rotate about mutually parallel axes of rotation.

According to one embodiment, the inner circumference, on which the inner toothing is formed, or the pitch circle radius of the Internal toothing at least 70%, preferably at least 80% or at least 90% of the outer circumference or the pitch radius of the outer toothing on which the outer toothing is formed, amount.

In other words, the internal toothing may be arranged relatively close to the external toothing, i. e.g. be significantly closer to the external teeth than at the central axis of rotation. Thus, the forces transmitted from the pinion to the sprocket are introduced close to its outer circumference and therefore need to be substantially less than in conventional constellations in which the forces causing the sprocket to rotate were centrally introduced to a shaft and thus close to the axis of rotation.

In particular, according to one embodiment, the pinion and the internal toothing may be configured such that the pinion engages the internal toothing in a reduced ratio of at least 5: 1, preferably at least 10: 1 or even at least 20: 1.

In other words, the number of teeth of the internal teeth can be at least five times greater than the number of teeth of the pinion or the inner diameter of the internal toothing be five times greater than the outer diameter of the toothing of the pinion. Thus, the torque of this driving motor is not only preferably introduced near the outer teeth in the sprocket by the pinion, but there is also a significant reduction. A fast rotating pinion can thus rotate the sprocket slower but with higher torque. In this case, preferably acts a low surface pressure between tooth flanks of the pinion and tooth flanks of the internal teeth. As a result, wear on the drive assembly can be reduced. In addition, smoothness of the driven over the sprocket conveyor belt can be improved. Overall, using the proposed drive arrangement, a very high reduction ratio can be achieved with preferably only one gear stage.

According to one embodiment, the pinion may be driven by the motor unit via a worm gear. Of course, a bevel gear instead of the worm gear can be used.

A worm gear can here be understood as a special worm gear, which has a helical so-called worm, which rotates during rotation a gripping gear which is also referred to as a worm wheel. The worm can be directly or indirectly connected to a shaft of the motor of the motor unit and rotated by this. The worm wheel can be connected directly or indirectly with the pinion engaging in the internal toothing. Finally, the rotation of the motor shaft can be transmitted via the pinion to the sprocket via the worm gear. The worm gear can in this case a significant reduction of, for example, more than 10: 1, preferably more than 25: 1 or more than 30: 1 cause.

In particular, according to one embodiment, the worm gear can be configured self-locking.

In this case, a self-locking means in mechanics a resistance caused by friction against slippage or twisting of two adjacent bodies. Once the static friction is exceeded, the bodies are no longer self-locking. In a worm gear, self-locking is caused by the sliding friction between worm and worm wheel, but typically occurs only at high gear ratios, low gear speeds, and helical pitch angle, for example, less than 5 ° (i.e., y <5 °).

Due to the self-locking property of the worm gear can be preferably achieved that even in the event that, for example, the motor of the motor unit fails, the driven by the motor via the worm gear pinion can not rotate uncontrollably. Instead, the pinion engaged with the loaded sprocket is inhibited from rotating by the worm gear. The sprocket can thus not rotate uncontrollably even in case of failure of the engine and thus the conveyor belt will not move uncontrollably. An additional safety brake for braking an uncontrolled rotation of the sprocket can thus be dispensed with.

According to one embodiment, the internal toothing is arranged on an inner circumference of the sprocket. In other words, the internal teeth should be an integral part of the sprocket and be formed on the inner circumference.

For example, the sprocket may be formed as a one-piece component, e.g. as a metal casting component. On the outer circumference of this component, the generally larger teeth of the outer toothing are then formed and on the inner circumference, the smaller teeth of the internal toothing are formed. The internal toothing is rotatably connected with the external teeth due to this integrated structure. It need no separate components rotatably connected to each other. As a result, labor and cost and a possible wear can be kept low. In addition, there is no risk of failure of the connections between adjacent components. Furthermore, a vorzuhaltender space can be kept minimal by the integral configuration of the external teeth and the internal teeth on a common, the sprocket-forming component. The teeth of the external teeth and / or the internal teeth can be produced inexpensively and precisely, for example by water jet cutting or laser beam cutting.

According to one embodiment, the sprocket can have a greater width at its inner circumference than at its outer circumference. In other words, where the internal toothing is formed on its inner periphery, the sprocket can have a larger width measured in the axial direction than where the outer toothing is formed on its outer circumference.

The width of the external toothing is usually given by the geometry of the conveyor chain with which the external toothing is to cooperate. In order to be able to transmit forces from the small pinion meshing with the internal toothing better to the sprocket, it may be advantageous to make the internal toothing wider than the external toothing. As a result, for example, a surface pressure between the pinion and the internal teeth can be kept low. This can minimize the risk of dimpling (so-called pitting). For example, the width of the inner toothing on the inner circumference at least 20%, preferably at least 50% or at least 100%, be greater than the width of the outer toothing on the outer circumference of the sprocket.

According to one embodiment, the drive arrangement may alternatively or additionally comprise a sprocket fixed non-rotatably to the sprocket. The internal toothing can be arranged at least partially on an inner circumference of the ring gear.

In other words, to be provided in the drive assembly internal teeth are not or at least not exclusively on the inner circumference of the sprocket itself, but it can be provided a complementary component in the form of a ring gear, on the inner circumference of the internal teeth is formed, and this sprocket can rotatably with be connected to the sprocket. If appropriate, toothing may be provided on the toothed rim exclusively on its inner circumference and an outer circumference without toothing, i. be formed in a circle geometry, so that the ring gear can also be referred to as an internal ring gear.

The sprocket may rotatably but reversibly releasably connected to the sprocket, for example by screwing or the like. Thus, the sprocket can be replaced as a separate component, for example, wear or defects. Alternatively, the sprocket may be attached to the sprocket irreversibly releasably, for example by riveting, welding, etc.

For example, the sprocket may be arranged laterally next to the sprocket and lateral flanks of the sprocket and the sprocket may preferably adjoin one another. The sprocket can then abut flat on one side of the sprocket and be rotatably connected thereto. Dimensions of the sprocket, in particular a width of the sprocket, can be chosen such that the internal teeth of the sprocket can interact well with the outer teeth of the pinion and thereby excessive surface pressures are avoided.

According to one embodiment, the sprocket may be formed with a plurality of sprocket plates stacked side by side.

In other words, the sprocket need not be integrally formed, but may be composed of a plurality of sprocket plates, which are sometimes referred to as slats. For this purpose, the sprocket plates, for example beforehand be punched or cut from thin metal sheets and then stacked next to each other to form together as a "laminated core" the sprocket. This can considerably facilitate a production.

The individual sprocket plates can, for example, have a thickness of between 0.2 mm and 10 mm, preferably between 1 mm and 5 mm. Overall, typically between two and twenty-five, preferably between three and ten sprocket plates can be stacked side-by-side so that the resulting sprocket can have a total width of between a few millimeters and a few centimeters. The sprocket or the sprocket plates forming it can be made of a resistant material, in particular of metal such as steel.

According to one embodiment, the sprocket is disposed on a side of the sprocket facing the motor unit.

In other words, the sprocket should be arranged laterally next to the sprocket on the side facing the motor unit. In this way, for example, to be bridged by the gearbox of the motor unit to be bridged distances between the sprocket engaged with the sprocket and the motor of the motor unit. As a result, mechanical forces or moments and thus ultimately wear can be kept low. In addition, a space of the entire drive assembly can be kept small.

According to one embodiment, it may be particularly advantageous to receive at least a portion of the motor unit spatially between the two sprockets of the drive assembly.

In other words, it may be preferable to arrange the motor unit in the region of the feed line or the return of the conveyor belt between the chain wheels conveying the conveyor chain. In this case, the motor unit is accommodated in a volume which anyway has to be provided for the conveyor belt or for the sprockets, and uses within this volume free areas for receiving the motor, the transmission, etc. The motor unit increases thus not the vorzuhaltenden for the escalator or the moving pavilion space.

In particular, when the motor unit is arranged between the two sprockets, it may be advantageous to arrange a sprocket to be provided on at least one of the sprockets on the side facing the motor unit side of the sprocket. In this case, then the ring gear as well as the motor unit is included in the volume between the two sprockets. The sprocket thus does not protrude laterally over the volume swept by the conveyor belt, but is added to save space within this volume and thus does not increase the installation space.

According to one embodiment, an internal toothing is respectively formed on the inner circumference of both sprockets, which is in each case arranged in a rotationally fixed relative to the outer toothing of the respective sprocket. In this case, the drive arrangement has two pinions to be driven by the motor unit, one of which engages in one of the internal toothings.

In other words, not only on one of the two sprockets an internal toothing is formed, but the drive assembly has on both sprockets internal teeth, which are rotatably connected to the external teeth of the sprockets. The motor unit in this case drives not only a single pinion, but two pinions, each of which meshes with internal teeth of one of the sprockets and thereby drives the associated sprocket. By synchronously driving both sprockets, a symmetrical load distribution within the drive assembly can be effected. The two sprockets can in this case, but not necessarily, rotatably coupled to each other.

According to one embodiment, the motor unit in such a configuration may comprise at least two separate motors. Each of the motors may each be configured to drive only one of the two pinions.

In other words, while it may be possible to drive both pinions with a single motor, it may be advantageous, at least in some constellations, to each to drive the pinion with a separate, associated engine. Each individual motor then only needs to provide half of the power to be provided by the drive assembly. As a result, the two engines can be significantly smaller than a single engine, which would have to provide the overall performance. Such smaller engines may possibly be more easily accommodated in the volume available in an escalator or moving walkway. In addition, such smaller engines can usually be purchased as standardized engines, whereas larger, more powerful engines often have to be developed only application-specific. Of course, more than two motors, each with a pinion can be used, which split on the two sprockets, driving the same.

It should be understood that some of the possible features and advantages of the invention are described herein with respect to different embodiments of the drive assembly or the escalator. A person skilled in the art will recognize that the features can be suitably combined, transmitted, adapted or replaced in order to arrive at further embodiments of the invention.

• Fig. 1 zeigt eine Übersichtsansicht einer Fahrtreppe.
• Fig. 2 zeigt eine perspektivische Ansicht eines Endbereichs einer Fahrtreppe.
• Fig. 3 zeigt eine perspektivische Ansicht einer Antriebsanordnung gemäß einer Ausführungsform der vorliegenden Erfindung.
• Fig. 4 zeigt eine Seitenansicht auf Verzahnungen einer Antriebsanordnung gemäß einer Ausführungsform der vorliegenden Erfindung.
• Fig. 5 zeigt eine perspektivische Ansicht auf Verzahnungen einer Antriebsanordnung gemäß einer alternativen Ausführungsform der vorliegenden Erfindung.
• Fig. 6 zeigt eine Schnittansicht durch die Verzahnungen der Antriebsanordnung aus Fig. 5 entlang der Linie A-A.

Embodiments of the invention will now be described with reference to the accompanying drawings, in which neither the drawings nor the description are to be construed as limiting the invention.

• Fig. 1 shows an overview of an escalator.
• Fig. 2 shows a perspective view of an end portion of an escalator.
• Fig. 3 shows a perspective view of a drive assembly according to an embodiment of the present invention.
• Fig. 4 shows a side view of gears of a drive assembly according to an embodiment of the present invention.
• Fig. 5 shows a perspective view of gears of a drive assembly according to an alternative embodiment of the present invention.
• Fig. 6 shows a sectional view through the teeth of the drive assembly Fig. 5 along the line AA.

The figures are only schematic and not to scale. Like reference numerals designate like or equivalent features throughout the several figures.

Fig. 1 shows an exemplary escalator 1, by means of which persons can be transported between two levels E1, E2, for example. Fig. 2 shows a perspective view of an end portion of such escalator. 1

The escalator 1 has two annularly closed conveyor chains 3. The two conveyor chains 3 are composed of a plurality of chain links. The two conveyor chains 3 can be displaced along a travel in traversing directions 5. The conveyor chains 3 are parallel to each other and are spaced apart in a direction transverse to the direction of travel 5.

Between the two conveyor chains 3, several tread units 7 extend in the form of treads. Each tread unit 7 is fastened near each of its lateral ends to one of the conveyor chains 3 and can thus be moved in the traverse directions 5 by means of the conveyor chains 3. The guided on the conveyor chains 3 tread units 7 thereby form a conveyor belt 9. To be able to relocate the conveyor chains 3, the escalator 1 has a drive assembly 25 (which in FIG. 1 only indicated very schematically).

In the area of a lower access 11 and in the region of an upper access 13, the conveyor chains 3 of the conveyor belt 9 are deflected by means of deflection wheels 15, 17. The guide wheels 15, 17 are held rotatably supported by bearings 21 on a supporting structure 19, which is usually in the form of a truss structure.

The escalator 1 further has a handrail 23, which is generally driven together with the conveyor chains 3 and thus moves synchronously with the conveyor belt 9.

FIG. 3 illustrates an embodiment of a drive assembly 25 according to the invention.

The drive assembly 25 has two mutually parallel sprockets 27, which can take over the deflecting function of the local deflection wheels 17, for example, at the upper end of the conveyor belt 9. Each sprocket 27 has at its outer periphery an external toothing 29 with radially outwardly projecting teeth 31. These teeth 31 are sized and shaped so that they, as in the FIG. 2 represented, in recesses 33 of the conveyor chain 3, for example, recesses 33 in or between adjacent chain links, can intervene.

The drive assembly 25 further includes a motor unit 35. The motor unit 35 has an electric motor 37 and a gear 39. The gear 39 is configured as a worm gear 41 in which a worm 43 driven by a shaft of the electric motor 37 meshes with a worm gear 45 and rotates it. The worm wheel 45 drives a pinion 47 via a common shaft.

In contrast to conventional drive arrangements for moving walks or escalators, however, the drive assembly 25 does not drive the sprocket 27 via a centrally located shaft. Instead, the pinion 47 interacts directly with an internal toothing 49 on the sprocket 27. The internal teeth 49 is rotatably connected to the external teeth 29 of the sprocket 27. An inner circumference, on which the inner toothing 49 is provided, runs essentially parallel to the outer circumference, on which the outer toothing 29 of the sprocket 27 is provided. In this case, viewed in the radial direction, the internal toothing 49 extends relatively closely spaced from the external toothing 29, ie the internal toothing 49 is clearly closer to the external toothing 29 than to the center point of the sprocket 27.

Because the drive arrangement 25 presented here transmits the drive power provided by it via the pinion 47 and the internal toothing 49 near the external toothing 29 to the sprocket 27, several advantages can be achieved.

For example, acting on the drive assembly 25 and in particular on the pinion 47 forces and torques can be kept low. In particular, surface pressures between tooth flanks of the pinion 47 and the internal teeth 49 can be kept low. Fast-rotating in this case is only the pinion 47, which minimizes, inter alia, wear and a smooth running can be maximized. Components of the proposed transmission 49 do not necessarily have to run in an oil bath. A simple grease lubrication may suffice. The direct drive causes at most low friction losses. Due to the internal teeth, the teeth have a low Hertzian pressure and thus a low risk of pitting.

Furthermore, the drive assembly 25 can be arranged in large parts between the adjacent sprockets 27 and thus in or near a covered by the conveyor belt 9 volume. In this case, the pinion 47 can act directly on the sprocket 27, without thereby increasing the overall width of the escalator 1 or a similarly equipped moving walk would be increased.

In addition, a total elasticity and a transmission play within the drive train formed by the drive train 25 is extremely low, since a torque caused by the motor 37 can be transmitted to the sprocket 27 very directly via a minimum of components.

In particular, if the worm gear 41 is designed to be self-locking, can be further dispensed with an additional provision of a braking device for hedging, for example, in the event that the motor 37 fails. As soon as the motor 37 ceases to rotate the worm 43 of the worm gear 41, the self-locking of the worm gear 41 prevents further rotation of the sprocket 27 coupled thereto via the pinion 47.

At the in Fig. 3 illustrated embodiment of the drive assembly 25, the internal teeth 49 is formed by means of a separate component in the form of a ring gear 51. The sprocket 51 is rotatably connected to the sprocket 27 by means of fastening screws 53.

At the in Fig. 3 illustrated embodiment, the ring gear 51 on one side of the sprocket 27 opposite to the side facing the motor unit 35 side of the sprocket 27 is arranged. Although this slightly increases the overall width of the drive assembly 25, this can bring benefits, such as ease of maintenance or replacement of the sprocket 51.

However, to minimize the overall width of the drive assembly 25, it may also be contemplated that the sprocket 51 on the opposite side of the sprocket 27, i. on the side facing the motor unit 35. The sprocket 51 is then closer to the gear 39 and is in particular within the volume covered by the conveyor belt 9, so that no additional space must be provided for him.

Another way to provide the internal teeth 49 is shown schematically in FIG FIG. 4 shown. In this case, the internal toothing 49 is not provided on a separate component in the form of, for example, a toothed rim 51, but is itself formed on the inner periphery of the sprocket 27 as an integral part of the sprocket 27.

Optionally, the sprocket 27 can thereby on the inner circumference, i. in the area of the internal teeth 49, be wider than on the outer circumference, i. on the external teeth to avoid excessive surface pressures between teeth 55 of the driving small pinion 47 and teeth 57 of the internal teeth 49.

In the Fig. 5 and 6 is a further variant for implementing the internal teeth 49 in perspective view and in a sectional view along the lines AA Fig. 5 illustrated. In this case, similar to the embodiment of FIG. 3 , the internal teeth 49 in turn formed on a separate sprocket 51. The ring gear 51 is not formed in one piece. Instead, the sprocket 51 composed of several thin sprocket plates 59. The sprocket plates 59 have substantially all the same shape and are stacked side by side in alignment with each other so that they together form inwardly projecting teeth 57 and thus the internal teeth 49.

At the in Fig. 3 In the illustrated embodiment, the drive assembly 25 has only one pinion 47 which meshes with only one of the sprockets 27 and which is driven by a motor unit 35 having a single motor 37. The driven by the pinion 47 sprocket 27 is rigidly connected in this case via a shaft 61 to the second sprocket 27, so that these two sprockets 27 are driven together.

However, embodiments of the drive assembly 25 are conceivable in which the motor unit 35 drives two pinions 47 and each of these pinion 47 drives one of the sprockets 27. In this case, an internal toothing 49 is provided on each sprocket 27. In such an embodiment, the two sprockets 27 need not necessarily be rigidly connected.

In this case, the motor unit 35 may have a single, sufficiently powerful motor 37. Alternatively, two separate motors may be provided. Each motor then drives one of the pinions 47 and can accordingly be less powerful and thus smaller.

In order to protect the internal teeth 49 and / or the pinion 47 against excessive wear, a cover can also be provided, by means of which it can be prevented that excessive dust and / or dirt in the region of the internal teeth 49 passes and thus excessive Abrieberscheinungen would. Such a cover could, for example, be fastened to a frame 63 holding the drive arrangement 25. The cover could, for example, have brushes or the like which largely cover an area adjacent to the internal teeth 49 and in particular adjacent to the rotating pinion 47 and thus inhibit penetration of dirt particles.

Finally, it should be noted that terms such as "comprising,""comprising," etc., do not exclude other elements or steps, and terms such as "a" or "an" do not exclude a multitude. It should also be appreciated that features or steps described with reference to any of the above embodiments may also be used in combination with other features or steps of other embodiments described above. Reference signs in the claims are not to be considered as limiting.

LIST OF REFERENCE NUMBERS

1

escalator

3

conveyor chain

5

traversing

7

tread unit

9

conveyor belt

11

lower access

13

upper access

15

guide wheel

17

guide wheel

19

carrying structure

21

camp

23

handrail

25

drive arrangement

27

Sprocket

29

external teeth

31

Teeth of the external toothing

33

recess

35

motor unit

37

engine

39

transmission

41

worm gear

43

slug

45

worm

47

pinion

49

internal gearing

51

sprocket

53

mounting screws

55

Teeth of the pinion

57

Teeth of the internal toothing

59

Sprocket sheets

61

wave

63

frame

Claims (15)

Drive assembly (25) for a moving walk or an escalator (1), comprising: two mutually parallel sprockets (27) each having an outer periphery provided on outer teeth (29) for driving in each case one with the outer toothing (29) engaged conveyor chain (3); at least one provided on an inner circumference internal toothing (49) which is rotatably relative to the outer toothing (29) of at least one of the sprockets (27) is arranged; a motor unit (35); at least one of the motor unit (35) to be driven pinion (47) which engages in the internal toothing (49). A drive assembly according to claim 1, wherein the pinion (47) is to be driven by the motor unit (35) via a worm gear (41) or bevel gear. Drive arrangement according to claim 2, wherein the worm gear (41) is self-locking. Drive arrangement according to one of the preceding claims, wherein the internal toothing (49) on an inner circumference of the sprocket (27) is arranged. Drive arrangement according to claim 4, wherein the sprocket (27) has a greater width at its inner circumference than at its outer periphery. Drive arrangement according to one of the preceding claims, further comprising a sprocket (51) fixed non-rotatably to the sprocket (27), wherein the internal toothing (49) is at least partially disposed on an inner circumference of the sprocket (51). Drive arrangement according to claim 6, wherein the sprocket (51) with a plurality of side by side stacked sprocket plates (59) is formed. Drive arrangement according to claim 6 or 7, wherein the sprocket (51) on a side facing the motor unit (35) side of the sprocket (27) is arranged. Drive arrangement according to one of the preceding claims, wherein at least a portion of the motor unit (35) between the sprockets (27) is arranged. Drive arrangement according to one of the preceding claims, wherein the inner circumference, on which the internal toothing (49) is formed, at least 70% of the outer circumference, on which the outer toothing (29) is formed, is. Drive arrangement according to one of the preceding claims, wherein the pinion (47) with the internal toothing (49) in a reduced ratio of at least 5: 1, preferably 10: 1 or more preferably 20: 1 is engaged. Drive arrangement according to one of the preceding claims, wherein in each case an internal toothing (49) is formed on the inner circumference of both sprockets (27), which in each case rotationally fixed relative to the outer toothing (29) of the respective sprocket (27) is arranged; and wherein the drive arrangement (25) has at least two pinions (47) to be driven by the motor unit (35), one of which engages in one of the internal toothings (49). Drive assembly according to claim 12, wherein the motor unit (35) has at least two separate motors (37) and each of the motors (37) is each adapted to drive only one of the pinions (47). Moving walkway or escalator (1) comprising: two conveyor chains (3); a plurality of tread units (7) each attached to both conveyor chains (3); a drive assembly (25) according to any one of claims 1 to 13 for driving the conveyor chains (3). Moving walkway or escalator (1) according to claim 14,
wherein the pinion (47) is to be driven by the motor unit (35) via a self-locking worm gear (41),
wherein the internal toothing (49) is arranged on an inner circumference of the sprocket (27) and / or the internal toothing (49) is arranged at least partially on an inner circumference of a toothed ring (51) fixed in a rotationally fixed manner to the sprocket (27),
wherein at least a portion of the motor unit (35) between the sprockets (27) is arranged, and
wherein the inner circumference on which the internal toothing (49) is formed amounts to at least 70% of the outer circumference on which the external toothing (29) is formed.

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