Smooth-running drive for an elevator

Abstract

The invention relates to an elevator, for example a passenger elevator. In particular, the invention relates to an elevator comprising a car (42) and a drive unit (40), wherein the drive unit (40) is connected to the car (42) via at least one toothed belt (50) and can move same via the toothed belt (50), wherein the toothed belt has a first pattern (62) of parallel grooves with a first orientation (68) and a second pattern (72) of parallel grooves with a second orientation (78). The invention is characterized in that the first orientation (68) and the second orientation (78) form an angle ranging from 20° to 160° in the first and second direction.

Description

[0001] Smooth-running drive for an elevator

[0002] Field of the invention

[0003] The present invention relates to an elevator and the drive therefor. The drive is low-wear and allows for very smooth and precise control of the elevator.

[0004] Background of the invention

[0005] The drive of an elevator, i.e., the lifting of the car, is usually achieved via steel cables and pulleys. Heavy counterweights are usually used. Various motors, predominantly electric motors, are used.

[0006] US Patent 5,921,351 discloses a belt-driven elevator. A plurality of driven belts is provided, as the belt drive comprises several elements, each element extending the height of one floor. The belts each have a rib pattern, with the ribs oriented perpendicular to the drive direction. This creates a uniform wave pattern transverse to the direction of the belt drive. Such a belt can have disadvantages when it comes to precisely guiding elevators, especially when belts are to be guided over a long length in the shaft.

[0007] The present invention aims to overcome such disadvantages in the prior art in a simple and economical manner and to provide an improved drive.

[0008] CONFIRMATION COPY This object is achieved by an elevator according to claim 1. Advantageous further developments are specified in the subclaims.

[0009] Further description

[0010] The invention relates to an elevator with a car and a drive unit. This can be a passenger elevator or a freight elevator. The drive unit raises the car. The car itself is typically designed as a passenger car with side walls and a car door. However, the car could also be fully or partially open. It could also be a transport unit designed for loads.

[0011] The drive unit should be connected to the car via at least one toothed belt and be able to move the car via this toothed belt. The movement should at least include raising the car. The connection can be direct or indirect, but typically the drive unit is connected to a drive gear that moves the toothed belt.

[0012] According to the invention, the toothed belt should have a first pattern of parallel grooves and a second pattern of parallel grooves. These grooves can be designed in a type of wave shape with peaks and valleys, for example, be essentially sinusoidal. The grooves can also follow a different pattern, for example a triangular pattern. The toothed belt can also have grooves with a square or rectangular cross-section. The grooves of the first pattern should have a first orientation. Orientation here is understood to mean the wave direction, i.e. an axis perpendicular to the parallel groove pattern. The second pattern can be designed in the same way and therefore has a second orientation. Typically, the toothed belts have mirror axes perpendicular to this orientation, so that a rotation of 180 degrees makes no difference. However, within angles smaller than 180 degrees, the orientation must be clearly defined.The orientation can be determined by an imaginary propagation direction of the waves perpendicular to the wave crest.

[0013] According to the invention, the first pattern and the second pattern should be oriented relative to each other such that an angle between 20° and 160° exists between the first orientation and the second orientation. An angle range of 30° to 90°, in particular 45° to 70°, is also expedient.

[0014] A groove can be provided between the first pattern of parallel grooves and the second pattern of parallel grooves. This groove facilitates the guidance of the timing belt; for example, a guide roller can be inserted into the groove. Furthermore, the provision of a groove has manufacturing advantages.

[0015] The drive unit can be designed in a manner typical for elevators. It can theoretically be driven by an internal combustion engine, but an electric motor is usually used. This motor can transmit its power to the toothed belt or a corresponding drive wheel via a gear. It is also possible, and is even favored by the present invention, to use a gearless drive motor.

[0016] If the timing belt is not ideally seated on a driven associated gear, high forces are required to correct the seat and even re-establish drive. This applies to a conventional timing belt, which only has an initial pattern of parallel lines. Such a timing belt can only be used with a gearless motor to a limited extent. However, a gearless motor has numerous advantages; in particular, it is less expensive than a motor with a gear and takes up less space. The use of the timing belt according to the invention therefore favors the use of a gearless motor, particularly for elevator applications, where a noticeable or audible jerk in the drive can easily create a feeling of uncertainty among elevator users.

[0017] The drive is conveniently provided by a first gear, over which the timing belt runs. According to the invention, such a gear is conveniently located at the end of a shaft connected to the motor. A direct connection is also conceivable. This is advantageous, and the invention makes it possible to eliminate the need for a deflection gear. Thus, a gearbox can be dispensed with entirely. This saves space and costs.

[0018] The lightweight construction made possible by the invention (especially the drive motor and shaft) can also be installed below the shaft ceiling to save space. The entire structure (especially the drive motor and shaft) can be supported or entirely carried by two posts, particularly guide posts.

[0019] The drive is also conveniently provided by two gears, a first gear and a second gear, each of which is driven by a toothed belt. Both gears can be connected directly to the drive motor via a shaft.

[0020] It is also practical if at least one deflection pulley is provided on the elevator car. For example, it is possible to fix the toothed belt at a fixed point above the car, for example at the top of the elevator shaft. From this point, the toothed belt can then be guided down around the car to the deflection pulley, and from this deflection pulley it can be fed to a drive wheel, which is also located at the top of the shaft. This allows a type of pulley system to be implemented, since the drive wheel is only subjected to a pulling force equivalent to half the weight of the car. Even more practical is to guide the car via several pulleys. For this purpose, a deflection pulley can be provided in the upper area of ​​the car and one in the lower area of ​​the car. A driven gear can be guided at the top of the elevator shaft, and a deflection gear at the bottom of the elevator shaft.This allows the car to be guided safely up and down. The drive wheel can also exert a downward pulley motion through the deflection at the bottom of the elevator shaft. Furthermore, the car as a whole is guided safely up and down. Additionally, one of the car's pulleys can be used, as explained, to minimize the tensile forces on the drive unit and implement a pulley system.

[0021] Such a design, however, results in a single timing belt controlling the movement of the car, and this belt is longer than the entire travel length of the car—depending on the design, even twice or three times as long. As the absolute length of the timing belt increases, so does its extensibility. Therefore, especially for such a design, it is advantageous to use a timing belt that runs securely over the drive pulley and the multiple idler pulleys, even when slightly stretched.

[0022] An elevator is usually installed within an enclosed elevator shaft. The car is then guided inside this elevator shaft. It is advantageous if the drive unit is also located within this shaft. This allows the length of the timing belt to be limited beyond what is unavoidable.

[0023] It is also practical if the timing belt is routed directly, usually vertically, from the drive pulley to a deflection pulley on the car. It would be conceivable to have a further deflection, so that the tensile force is not transferred directly from the car to the drive pulley. However, such a deflection potentially leads to additional stretching of the timing belt. The deflection itself also exposes the timing belt to additional mechanical stress, which can change its structure and thus complicate smooth and precise guidance, especially during extended periods of elevator operation.

[0024] A toothed belt according to the present invention is expediently made of plastic, entirely or partially, and preferably more than 50% of its weight. Fiber-reinforced plastic and layered structures, such as plastic deposited on a fiber web, are suitable.

[0025] Further features, as well as advantages of the invention, will become apparent from the following drawings and the accompanying description. In the figures and the accompanying descriptions, features of the invention are described in combination. However, these features can also be encompassed by a subject matter according to the invention in other combinations. Each disclosed feature is therefore also to be considered as disclosed in technically reasonable combinations with other features. Some of the figures are slightly simplified and schematic.

[0026] Fig. 1 shows a sketchy perspective view of an elevator

[0027] Fig. 2 shows two alternatives for an elevator drive in sketchy views

[0028] Fig. 3 shows the drive surface of a toothed belt in plan view

[0029] Fig. 4 shows a horizontal section through an elevator shaft. Fig. 1 shows a schematic perspective overall view of an elevator that can be used in the context of the present invention. A variety of other elevator designs are also conceivable. The elevator comprises the elevator shaft 10. This is preferably constructed over a rectangular base area, i.e., has a cuboid shape overall. A square base area is also expedient. The elevator shaft can be provided by a building, for example, cast from concrete, or it can be manufactured independently of the building using its own components. For example, an elevator shaft can be manufactured from posts and struts and inserted panels. Such panels can be made of plastic, metal, or glass. The elevator shaft can also be designed for retrofitting to an existing building.

[0030] The elevator shaft comprises a front wall 12, adjoining a side wall 14, adjoining the rear wall 16, and opposite the side wall 14, the side wall 18. In accordance with the shaft design, all side walls have a substantially rectangular, flat shape. The side walls are constructed above the floor 20.

[0031] Access openings are provided in the side walls, namely access opening 22 on a first level in the front wall 12. Above this, access opening 24 is arranged in the side wall 18. As a further access opening, access opening 26 is provided on a higher level in the front wall 12. The access openings are typically each closed with shaft doors. All access openings can be provided on one side, for example, all in the front wall 12, or the access openings can be provided in different side walls. The elevator construction shown even allows access openings to be provided in all four shaft walls. The shaft 10 is delimited at the top by the ceiling 28. However, it would be quite conceivable, particularly within the scope of the present invention, to provide a ceilingless shaft.

[0032] The internal scaffold 30 is erected within the shaft 10. This consists of a first post 32, located in one corner of the shaft. The second post 34 is located in the diagonally opposite corner. The two posts are connected by the cross brace 36, which runs diagonally in the upper area of ​​the shaft. It can run directly below the ceiling 28.

[0033] The cross member 36 can support various components; symbolically represented here are drive rollers 38A and 38B, which are provided at the ends of the cross member 36 adjacent to the posts 32 and 34. The cross member 36 can also support a drive unit 40. The drive unit 40 will typically comprise an electric motor that can drive the drive rollers 38 via suitable drive means, for example, corresponding shafts. Drive rollers are particularly suitable for driving toothed belts that can raise and lower an elevator car. This will be explained in more detail below.

[0034] Fig. 2 shows, in a symbolic and simplified representation, two practical drive options for an elevator car. According to option (A), the elevator car 42 is equipped with a deflection pulley 44 above its center. An upper support 46 (for example, the cross member or the shaft ceiling) carries a drive pulley 38. A winding or unwinding unit is provided next to the drive pulley 38, by which the toothed belt 50 can be wound or unwound.

[0035] The toothed belt 50 is guided over the drive pulley 38 and forms a positive connection with the pulley. For this purpose, the pulley is expediently equipped with teeth that correspond to the teeth of the toothed belt. Accordingly, the toothed belt can be wound up or unwound. As the toothed belt unwinds, the cabin 42 moves downward, while sections of the toothed belt 50 are guided over the deflection pulley 44. The end of the toothed belt is firmly anchored to the upper bracket 46. In this respect, the principle of a pulley block is used.

[0036] If a one-meter-long section of the toothed belt 50 is unwound, the car 42 will only move half a meter downward. The upward movement is similar, so that the drive roller 38 only has to bear half the car's load. As clearly visible in the sketch, the application of the pulley principle requires a long toothed belt 50. Of course, the car 42 would be held in place by guide devices in practice, which, however, are not shown here for simplicity.

[0037] Option (B) represents a more complex but also more advantageous design for raising and lowering a cabin. In this case, a significantly longer toothed belt must be provided for the same travel path of the cabin.

[0038] A lower deflection pulley 52 is attached to the lower area of ​​the shaft, usually at ground level. Furthermore, a lower deflection pulley 54 is attached to the lower area of ​​the cabin. The toothed belt 50 is guided from the lower anchor point 56 to the lower deflection pulley 54 and then returned to ground level. There, the toothed belt 50 is guided through the lower deflection pulley 52 and to the drive pulley 38 mounted above. From this drive pulley, the toothed belt 50 is guided to the cabin 42, where it is deflected at the upper deflection pulley 44. The toothed belt finally ends at the upper anchor point 58, which can be attached to the shaft ceiling. In this way, a type of circumferential toothed belt guide is created. If one meter of toothed belt is fed downwards by the drive pulley 38, the cabin 42 will lower by half a meter. In this respect, the pulley principle is also applied here. At the same time, the toothed belt is guided upwards from the lower deflection pulley 52.In this case, tension is exerted on the car via the lower deflection pulley 54. This ensures good guidance of the car, regardless of the additional guide devices usually provided. The raising or lowering height is also very easy to control. Furthermore, no winding or unwinding device is required for the timing belt.

[0039] However, the advantages of this design come at the cost of requiring a long timing belt. The timing belt must be at least three times as long as the shaft height.

[0040] The length of the timing belt is not without its problems. Regardless of the material from which the timing belt is made, a certain amount of expansion under tension is unavoidable. The timing belt naturally also relaxes when the tension is reduced. The length of the timing belt can also change under the influence of temperature or humidity.

[0041] In the variant shown as option (B), the height guidance of the cabin is no longer as precise as desired. Furthermore, the engagement of the toothed belt with the rollers suffers. Both the drive roller 38 and the idler pulleys (in the example, rollers 44, 52, and 54) will generally offer a toothed rolling surface to guide the belt smoothly. However, if the belt expands, for example, secure engagement with such a rolling surface is no longer possible.

[0042] This can cause the timing belt to jump off a pulley. At the very least, it can make the height guide unreliable. It can also happen that the timing belt, moving from a non-engaged position, is suddenly brought back into engagement with one or all of the pulleys due to the application of force (for example, when raising the car). Such sudden engagement results in increased wear. Furthermore, the jerking can be felt in the car, which does not give users the feeling of safe elevator operation.

[0043] Such difficulties, which occur particularly in the elevator constructions shown, can be avoided within the scope of the present invention with an improved toothed belt.

[0044] These aspects are particularly relevant when using a gearless drive, as explained above. Good engagement of the timing belt with the drive wheel is especially important where only one driven wheel is used.

[0045] Fig. 3 shows a plan view of the drive side 60 of a toothed belt 50 according to the invention. The first wave pattern 62 can be seen on the right side of the toothed belt. This consists of first wave troughs 64, the lower two of which are highlighted with reference numerals. Behind each wave trough extends a wave crest; two first wave crests 66 of the first wave pattern are also highlighted. The first wave pattern 62 has an overall first orientation 68. This is the direction perpendicular to the wave crests, which can be thought of as the propagation direction of the waves.

[0046] The timing belt has a centerline 70. The second wave pattern 72 extends to the left of the centerline. This second wave pattern 72 includes second wave troughs 74, the first two of which are again highlighted with reference numerals. Adjacent to the wave troughs are second wave crests, two of which are again highlighted with reference numerals 76. The second wave pattern 72 has a second orientation 78 overall.

[0047] As can easily be seen, the second orientation 78 deviates from the first orientation. Both orientations form an acute angle to each other. This angle a (alpha) is approximately 60 degrees.

[0048] It is also possible to use toothed belts 50 in which a groove is provided in the region of the center line 70, so that the first wave crests 66 are spaced from the second wave crests 76 in the region of the groove.

[0049] Fig. 4 shows a horizontal section through the shaft 90 of an elevator according to the invention. The view is from above onto the shaft floor 92. The shaft is surrounded by the first shaft wall 94 and the adjacent second shaft wall 96. Opposite the first shaft wall 94 are the third shaft wall 98 and the first shaft door 100. Opposite the second shaft wall 96 are the fourth shaft wall 102 and the second shaft door 104. The shaft is constructed entirely with a frame, thus suitable, for example, for retrofitting an elevator, and is supported by corner posts. The corner posts 106A, 106B, 106C, and 106D are visible.

[0050] Guide posts are provided at two diametrically opposite corners, which can be connected to the corner posts by connecting elements. Connecting element 108 connects guide post 110 to corner post 106D. Opposite is guide post 112, which is connected to corner post 106B by connecting element 114.

[0051] The guide posts 110 and 112 form the inner framework and correspond to the posts 32 and 34 in the schematic representation of Fig. 1 . The guide posts are designed here as T-beams. Not only can they carry a cross brace in their upper area, but they also serve to guide the car along their length. Accordingly, the base of the T-beam points towards the interior of the shaft. The view takes in the drive elements in the upper shaft area. There you can see the shaft 80, which drives the first drive wheel 82 and the second drive wheel 84. A drive motor 86 for driving the shaft is shown schematically. Also shown schematically is a gearbox 88, which, however, can also be omitted within the scope of the present invention.

[0052] Overall, one can see how a reliable and precise elevator can be manufactured that is low in wear and gives users a feeling of high security at all times.

[0053]

[0054] 10 shafts

[0055] 12 front wall

[0056] 14 Side wall

[0057] 16 Rear wall

[0058] 18 Side wall

[0059] 20 floor

[0060] 22 Access opening

[0061] 24 Access opening

[0062] 26 Access opening

[0063] 28 Ceiling

[0064] 30 internal scaffolding

[0065] 32 first post

[0066] 34 second post

[0067] 36 Cross brace

[0068] 38 Drive shaft

[0069] 40 drive

[0070] 42 cabins

[0071] 44 pulley

[0072] 46 upper bracket

[0073] 48 Reel

[0074] 50 timing belts

[0075] 52 lower pulley on the floor

[0076] 54 lower pulley of the cabin

[0077] 56 Anchor point

[0078] 58 Anchor point

[0079] 60 Drive side of the timing belt

[0080] 62 first wave pattern

[0081] 64 first trough

[0082] 66 first wave crest

[0083] 68 first orientation center line second wave pattern second wave trough second wave crest second orientation drive shaft first drive wheel second drive wheel motor gear unit shaft shaft floor first shaft wall second shaft wall third shaft wall first shaft door fourth shaft wall second shaft doorA corner post B corner post C corner post D corner post connecting element guide post guide post connecting element

Claims

An elevator comprising a cabin (42) and a drive unit (40), wherein the drive unit (40) is connected to the cabin (42) via at least one toothed belt (50) and can move the cabin via the toothed belt (50), the toothed belt having a first pattern (62) of parallel grooves of a first orientation 68 and a second pattern (72) of parallel grooves with a second orientation (78), characterized in that the first orientation (68) and the second orientation (78) form an angle between 20° and 160°, and in that a gearless motor is provided in the drive unit (40). An elevator according to the preceding claim, wherein a groove is provided between the first pattern (68) and the second pattern (78). An elevator according to any of the preceding claims, wherein the drive is effected via a first gear (38) over which the toothed belt (50) runs.Elevator according to any of the preceding claims, wherein at least one deflection pulley (44, 54) is provided on the cabin. Elevator according to the preceding claim, which has an elevator shaft (90) having an upper end region and a lower end region, wherein the driven gear (38, 82, 84) is located in the upper end region and wherein a deflection pulley (52) is located in the lower end region and the cabin has two deflection pulleys (44, 54). Elevator according to any of the preceding claims, wherein the elevator has an elevator shaft (90) and the cabin (42) is located in the shaft. The interior of this elevator shaft is guided, and the drive unit (40) is also provided in the shaft. Elevator according to one of the preceding claims, wherein the toothed belt (50) is guided vertically from the drive pulley (38) to a first deflection pulley (44) of the cabin. Elevator according to one of the preceding claims, wherein the toothed belt (50) is made of plastic. Elevator according to one of the preceding claims, wherein the cabin (42) is equipped with cabin doors which can interact with shaft doors (100, 10). Elevator according to one of the preceding claims, which is guided by a first guide rail (110) and a second guide rail (112), wherein the guide rails are connected in the upper region by a crossbeam (36), and the crossbeam (36) supports the drive unit (40).

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