ELEVATOR SYSTEM WITH AIR-BEARING LINEAR MOTOR

Abstract

An elevator system has an elevator shaft, an elevator car and a drive device for displacing the elevator car within the elevator shaft. The drive device is a linear motor that has a stationary part secured to a shaft wall of the elevator shaft and a movable part secured to the elevator car. The drive device has an air bearing between the stationary part and the movable part that keeps the stationary part spaced apart from the movable part via an air gap therebetween.

Claims

1-14. (canceled)

15. An elevator system comprising: an elevator shaft; an elevator car displaceable in the elevator shaft; a drive device for displacing the elevator car within the elevator shaft; wherein the drive device includes a linear motor having a stationary part secured to a shaft wall of the elevator shaft and a movable part secured to the elevator car; and wherein the drive device has an air bearing formed between the stationary part and the movable part, the air bearing keeping the stationary part spaced apart from the movable part via an air gap created therebetween.

16. The elevator system according to claim 15 wherein the air bearing is an aerostatic air bearing having an air supply that presses pressurized air into the air gap between the stationary part and the movable part.

17. The elevator system according to claim 15 wherein the air bearing creates the air gap with a gap width of less than 0.1 mm.

18. The elevator system according to claim 15 wherein the stationary part of the linear motor is flexibly displaceable on the shaft wall in a direction orthogonal to a surface of the stationary part facing the movable part and/or the movable part of the linear motor is flexibly displaceable on the elevator car in a direction orthogonal to a surface of the movable part facing the stationary part.

19. The elevator system according to claim 15 wherein the stationary part includes active electromagnets that can be energized and wherein the movable part includes passive permanent magnets.

20. The elevator system according to claim 15 wherein the elevator car has a backpack construction and the movable part of the linear motor is arranged on a rear side of the backpack construction.

21. The elevator system according to claim 15 wherein the elevator system has at least two of the elevator car and the at least two elevator cars are displaceable within the elevator shaft.

22. The elevator system according to claim 15 wherein the elevator shaft has vertical regions and non-vertical regions for displacing the elevator car.

23. The elevator system according to claim 15 wherein the linear motor is a vertical linear motor with the stationary part extending vertically for displacing the elevator car vertically.

24. The elevator system according to claim 15 wherein the linear motor is a horizontal linear motor with stationary part extending horizontally for displacing the elevator car horizontally.

25. The elevator system according to claim 15 wherein the drive device includes a horizontal linear motor having another stationary part extending horizontally and another movable part secured to the elevator car for displacing the elevator car horizontally.

26. The elevator system according to claim 15 wherein the drive device includes an additional linear motor producing a compensating force on the elevator car that counteracts a tilting moment acting on the elevator car.

27. The elevator system according to claim 15 wherein the drive device has a brake coating adjacent to the air gap.

28. The elevator system according to claim 15 including a controller for activating and deactivating the air bearing in a controllable manner.

29. The elevator system according to claim 15 wherein the air bearing has a plurality of air bearing segments arranged one behind another along a movement path of the elevator car in the elevator shaft, and wherein the air bearing segments are individually activated and deactivated in a controllable manner.

Description

DESCRIPTION OF THE DRAWINGS

[0061] FIG. 1 is a lateral sectional view of an elevator system according to one embodiment of the present invention.

[0062] FIG. 2 is a front view of an elevator system according to one embodiment of the present invention.

[0063] The drawings are merely schematic and not to scale. Identical reference signs refer to identical or equivalent features in the various figures.

DETAILED DESCRIPTION

[0064] FIGS. 1 and 2 schematically show components of an elevator system 1 in a lateral and frontal sectional view respectively. The elevator system 1 has an elevator shaft 3 in which at least one elevator car 5 can be displaced in a vertical region 21. Two of the elevator 5 are shown as elevator cars 5′ and 5″ in FIG. 2. In order to be able to displace the elevator car 5, a drive device 7 is provided. The drive device 7 comprises a linear motor 9 with a stationary part 13 secured to a wall 11 of the elevator shaft 3 and a movable part 15 secured to the elevator car 5. Furthermore, the drive device has an air bearing 17 which is formed between the stationary part 13 and the movable part 15 of the linear motor 9 in order to space these two parts 13, 15 apart from one another via an air gap 19 therebetween.

[0065] In the example shown in FIG. 2, the elevator system 1 with its elevator shaft 3 has two of the vertical region 21 being vertical regions 21′, 21″ that extend in parallel with one another and are horizontally spaced apart from one another, as well as two non-vertical, in particular horizontal regions 23′, 23″ that extend in parallel with one another and are vertically spaced apart from one another. The two horizontal regions 23′, 23″ interconnect the two vertical regions 21′, 21″.

[0066] Multiple elevator cars 5′, 5″ can be displaced independently of one another in the elevator shaft 3 constructed in two parts in this way. For example, an elevator car 5′ can travel upward in one of the vertical regions 21′. Arriving at an upper end of the vertical region 21′, this elevator car 5′ can be displaced horizontally through the horizontal area 23′ there toward the other vertical region 21″. The elevator car 5′ can then be displaced downward through this vertical region 21″ in order to ultimately be able to reach its initial position in the first-mentioned vertical region 21′ again through the other horizontal region 23″ located there.

[0067] In order to be able to displace the elevator car 5 accordingly, the drive device 7 has a plurality of linear motors 9.

[0068] In particular, vertical linear motors 25 are provided to apply a force 27 directed vertically upward to the elevator car 5. This force 27 can overcompensate for a weight of the elevator car 5 so that the elevator car 5 can be moved upward.

[0069] In the examples shown, components for a vertical linear motor 25 are provided in each of the two vertical regions 21 (21′, 21″) of the elevator shaft 3, which motor extends substantially along the entire length of the vertical region 21 and is thus designed for a displacement of the elevator car 5 along a movement path that extends over the entire length of the vertical region 21.

[0070] The vertical linear motor 25 has a stationary part 29 attached to the wall 11 of the elevator shaft 3 and a movable part 31 attached to the elevator car 5. In the example shown, the stationary part 29 is designed as an active part of the vertical linear motor 25 in order to generate temporally and/or spatially varying magnetic fields. For this purpose, the stationary part 29 is divided into a large number of linear motor segments 33 (see FIG. 2). The linear motor segments 33 are anchored to the wall 11 of the elevator shaft 3 vertically one above the other in a linear arrangement. In each linear motor segment 33 there is an electromagnet 35 in the form of a coil that can be energized, for example. The energizing of the electromagnets 35 in the various linear motor segments 33 can be controlled in an open or closed loop for example by a controller 37 (for reasons of clarity, wiring of the linear motor segments 33 to the controller 37 has not been shown). The movable part 31 of the vertical linear motor 25 is designed as a passive part and has permanent magnets 39 for generating magnetic fields that are constant over time.

[0071] Furthermore, the drive device 7 has horizontal linear motors 41. The horizontal linear motors 41 are designed to generate temporally varying magnetic fields by means of which a horizontally directed force 43 can be exerted on the elevator cars 5. In the example shown, components of the horizontal linear motors 41 are located on each of the horizontal regions 23′, 23″ of the elevator shaft 3 in order to be able to displace the elevator cars 5′, 5″ through one of these horizontal regions 23′, 23″ in each case.

[0072] The horizontal linear motors 41 also have a stationary part 45 and a movable part 47. The stationary part 43 is in turn attached to the wall 11 of the elevator shaft 3 and designed as an active part with electromagnets 35 provided therein. The stationary part 43 extends over the entire width of the two vertical regions 21′, 21″ of the elevator shaft 3 that are arranged next to one another, including the horizontal region 23′, 23″ in between. In this case, linear motor segments 33 can be arranged horizontally next to one another. The movable part 47 is attached to the elevator car 5′, 5″ as a passive part.

[0073] In addition, the drive device 7 has additional linear motors 49 (FIG. 2). These additional linear motors 49 are designed to bring about compensating forces 51 on the elevator car 5 which counteract a tilting moment of the elevator car 5. For this purpose, the additional linear motors 49 can be arranged in such a way that the compensating forces 51 they produce act laterally at a distance from the forces 27 produced by the vertical linear motor 25, so that overall a torque is produced on the elevator car 5 which can compensate as far as possible for the tilting moments acting in the elevator car 5.

[0074] In the example shown, the additional linear motors 49 are designed as additional linear motors extending in the vertical direction and are spaced laterally apart from a relevant associated vertical linear motor 25. Together with the associated vertical linear motor 25, a pair of forces 27, 51 directed vertically upward or downward can thus be exerted on the elevator car 5 with the aid of the additional linear motor 49, between which forces a torque acting on the elevator car 5 is established which can compensate for a tilting moment occurring, for example, due to inhomogeneous loading of the elevator car 5.

[0075] Components of additional linear motors 53 are also provided on the horizontal regions 23′, 23″ of the elevator shaft 3. With the aid of stationary parts 54 arranged vertically on the wall 11 and movable parts 56 arranged vertically on the elevator car 5 of such additional linear motors 53, holding forces 55 can be generated which correspond to the weight of the elevator car 5, so that the weight of the elevator car 5 can be held by means of these additional linear motors 53 while it is moved horizontally through the horizontal regions 23′, 23″ by means of the horizontal linear motor 41.

[0076] Considerable forces are exerted on the elevator car 5 by the various linear motors 9. Not only do forces 27, 43, 51, 55 act in the vertical direction or horizontal direction in planes parallel to a movement path of the elevator car 5, but there are also forces that pull the elevator car 5 toward the stationary parts 13 of the linear motors 9. In particular, due to the magnetic fields brought about in the linear motors 9, attractive forces act between the relevant stationary part 13 and the associated movable part 15.

[0077] In order to still be able to move the stationary and movable parts 13, 15 relative to one another with little friction, the air bearing 17 with the air gap 19 is formed between them. The air bearing 17 is preferably designed as an aerostatic air bearing. For this purpose, the air bearing 17 has an air supply (FIG. 1 enlarged area) by means of which pressurized gas can be pressed into the air gap 19. For this purpose, the air supply 57 can have a compressor 59 and/or a pressure reservoir 61. Pressurized gas generated or stored there can be passed through lines (not shown for reasons of clarity) of the air supply 57 to nozzles 63, which in the example shown open into the adjacent air gap 19 at a surface of the stationary part 13 of the linear motor 9.

[0078] By adjusting different parameters such as a geometric arrangement and dimensioning of the nozzles 63 and adjusting the pressure of the supplied gas to 4,000-5,000 hPa, for example, the air bearing 17 can be designed in such a way that the air gap 19 has a gap width S in the range of 0.01-0.05 mm, for example. The air gap 19 acts as a plain bearing between the stationary part 13 and the movable part 15 of the linear motor 9.

[0079] The stationary part 13 and/or the movable part 15 can preferably be held so as to flexibly displaceable on the wall 11 or on the elevator car 5. For this purpose, a flexible sheet metal 65 can be provided for example on a rear side of a supporting structure 67 accommodating the electromagnets 35. For example, the coils forming the electromagnets 35 can be molded into the supporting structure 67 from a cured resin. A surface of such a supporting structure 67 that faces the air gap 19 can be very smooth. The supporting structure 67 of the stationary part 13 of the linear motor 9 can be held from behind by the flexible sheet metal 65 such that the entire supporting structure 67 including the electromagnet 35 can be flexibly and resiliently displaced slightly orthogonally to the movable part 15 of the linear motor 9. Inaccuracies in the arrangement of the stationary and the movable parts 13, 15 relative to one another can hereby be at least partially compensated for.

[0080] In the example shown, the car 5 of the elevator system 1 is designed with a backpack construction. The respective movable parts 15, 31, 47, 56 of the different linear motors 9, 25, 41, 49, 53 are arranged in a rear part of the elevator car 5, in particular on a frame 69 holding the elevator car 5 from behind.

[0081] In the example shown, a brake coating 71 is also provided in the drive device 7 adjacent to the air gap 19. The brake coating 71 can be provided for example on a surface of a further supporting structure 75, for example consisting of cured resin, in which the permanent magnets 39 of the movable parts 31, 47, 56 of the linear motors 9, 25, 41, 49 are accommodated. The brake coating 71 can be a layer or a component made of a polymer material or an elastomeric material, for example.

[0082] In this case, the air bearing 17 can be activated and deactivated in a locally controllable manner via the controller 37, for example. For this purpose, the air bearing 17 can be divided into a large number of air bearing segments 73 which can be supplied with compressed air in an individually controllable manner. For this purpose, for example controllable valves (not shown) can be provided in compressed air lines. The air bearing segments 73 can be arranged one above the other or next to one another along a movement path of the elevator car 5. Accordingly, if necessary, one or more of the air bearing segments 73 can be deactivated locally at the position at which an elevator car 5 is currently located. Without the air gap 19 created by the relevant air bearing segment 73, the movable part 15 presses against the stationary part 13 of the relevant linear motor 9. Because of the brake coating 71 arranged between the two parts 13, 15, a braking effect can thus be brought about on the elevator car 5 that was previously being displaced. In other words, with a suitable design and controllability of the respective air bearing segments 73, the air bearing 17 can provide an additional functionality as a braking means for braking movements of the elevator car 5 at different locations of the elevator shaft 3.

[0083] Finally, it should be noted that terms such as “comprising,” “having,” etc. do not preclude other elements or steps, and terms such as “a” or “an” do not preclude a plurality. Furthermore, it should be noted that features or steps that have been described with reference to one of the above embodiments may also be used in combination with other features or steps of other embodiments described above.

[0084] In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope.