ELECTRIC LINEAR MOTOR

Abstract

The invention refers to a linear electric motor comprising at least one linear stator having stator teeth, which stator is designed to be located in a fixed correlation to an environment and extending over a movement path and, the linear electric motor further comprising at least one mover co-acting with and moving along the stator. According to the invention at least the top portion of the stator teeth facing the mover is inclined with respect to the normal of the stator beam.

Claims

1. A linear electric motor comprising at least one linear stator having stator teeth, which stator is designed to be located in a fixed correlation to an environment and extending over a movement path, the linear electric motor further comprising at least one mover co-acting with and moving along the stator, characterized in that at least the top portion of the stator teeth facing the mover is inclined with respect to the normal of the stator beam.

2. The linear electric motor according to claim 1, wherein the stator teeth are inclined only a half of their total length at the maximum.

3. The linear electric motor according to claim 1, wherein the central line of the stator teeth is curved.

4. The linear electric motor according to claim 1, wherein the base portion of the stator teeth is wider than their top portions facing the mover.

5. The linear electric motor according to claim 1, wherein the stator teeth are inclined over the upper part of their length, preferably over their entire length.

6. The linear electric motor according to claim 1, wherein the inclination is in the downwards direction.

7. The linear electric motor according to claim 1, wherein the base portion of the stator teeth is wider than their top portions facing the mover.

8. The linear electric motor according to claim 1, wherein at least or only the top portion of the stator teeth facing the mover is inclined.

9. The elevator comprising at least one elevator car running in an elevator shaft which elevator does not have a counterweight and in which elevator the elevator car is suspended and driven by a linear electric motor according to claim 1, wherein the stator of the linear electric motor is designed to be located in a fixed correlation to an environment and extending over a vertical movement path of the elevator car in the shaft, and wherein the at least one mover of the linear electric motor is configured to be connected to the at least one elevator car.

10. The elevator according to claim 9, wherein the mover has electro-magnetic mover components of the linear electric motor, which electro-magnetic mover components co-act with the linear stator, preferably with the stator iron, and which electro-magnetic mover components are controlled to drive the elevator car along the movement path in the shaft.

11. The elevator according to claim 10, wherein the electro-magnetic mover components are at the same time controlled to regulate an air gap between the mover and the stator.

12. The elevator according to claim 9, wherein at least two stators are fixed to a stator beam comprising a support structure for the at least two stators and at least one fastening element to fix the support structure to the environment, e.g. the elevator shaft.

13. The elevator according to claim 9, wherein the at least one mover is located on one side of the elevator car for a rucksack-suspension.

14. The elevator according to claim 9, wherein the mover is in a direction perpendicular to the stator beam releasable from the stator beam.

15. The elevator according to claim 9, wherein one or more wireless charging stations is/are located along the length of the stator beam, and the elevator car has a battery as well as a wireless battery charger adapted to interact with the wireless charging station(s), that battery being further configured to energize the electro-magnetic mover components.

16. The elevator according to claim 9, being configured to be installed as a high rise elevator with a vertical length of more than 50 m, preferably more than 100 m.

17. The linear electric motor according to claim 2, wherein the central line of the stator teeth is curved.

18. The linear electric motor according to claim 2, wherein the base portion of the stator teeth is wider than their top portions facing the mover.

19. The linear electric motor according to claim 3, wherein the base portion of the stator teeth is wider than their top portions facing the mover.

20. The linear electric motor according to claim 2, wherein the stator teeth are inclined over the upper part of their length, preferably over their entire length.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The patent or application file contains at least one color drawing. Copies of this patent or patent application publication with color drawing will be provided by the USPTO upon request and payment of the necessary fee.

[0045] The invention is now described hereinafter with respect to the enclosed drawing. In this drawing

[0046] FIG. 1 shows a side view of an elevator shaft with a linear elevator motor according to the invention comprising two parallel stator beams,

[0047] FIG. 2 shows a horizontal cross-section of the parts of the elevator motor and the guide rails in the area between the elevator car and the shaft wall of FIG. 1,

[0048] FIG. 3 shows a cross-section through a stator beam and a mover of FIG. 4,

[0049] FIG. 4 shows a schematic drawing of the function of a switching permanent magnet motor (FSPM) used as the elevator motor, whereby the stator has stator teeth pointing downwards,

[0050] FIG. 5 shows an alternative embodiment of a stator with rounded teeth, whose ends point downwards,

[0051] FIG. 6 shows a vertical cut through a stator and mover with the corresponding magnetic flux lines, whereby the stator teeth have an enlarged base, and

[0052] FIG. 7 shows a side view of an elevator having two elevator shafts which are connected at their upper and lower ends with horizontal passages.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0053] It is emphasized that identical parts or parts with the same functionality are designated by the same reference numbers in all figures.

[0054] FIG. 1 shows an elevator 10 comprising an elevator shaft 12 wherein an elevator car 16 moves up and down as an element to be moved. The elevator 10 has a linear elevator motor 14. The linear elevator motor 14 comprises stators 50 (see FIG. 3) located in a side face of a stator beam 18 which is mounted with fastening elements 20 to a shaft wall 22 of the elevator shaft 12. In this example, the elevator 10 has two parallel stator beams 18, which can be seen in FIG. 2.

[0055] The elevator car 16 comprises two movers 24, 26 located one above the other. The lower mover 24 is located in the lower half of the elevator car whereas the upper mover 26 is located in the upper half of the elevator car. These two movers 24, 26 comprise electro-magnetic components as e.g. irons, windings and permanent magnets 70, 71, 72, 74, 76 (FIG. 4) which co-act with stator poles 52 located in the side faces of the stator beam 18, formed by stator teeth. Accordingly, the elevator car travels upwards and downwards via corresponding control of both movers 24, 26 co-acting with the stator beams 18.

[0056] Of course, the elevator car has a corresponding set of two movers 24, 26 for each vertical stator beam 18 so that the elevator car 16 has in total four movers, two lower movers 24 and two upper movers 26 to co-act with two stator beams 18.

[0057] Of course, each stator beam 18 may have one or several stators 50 as it is shown in FIGS. 2 and 3.

[0058] Although it is preferred that the stator beams 18 and movers 24, 26 of the elevator 10 of FIG. 1 also form an electro-magnetic guide for the elevator car 16 so that any guide rollers and guide rails can be omitted, FIG. 2 shows in one embodiment optional car guides 32, 34 of the elevator car 16 co-acting with optional guide rails 28 running vertically along the shaft wall 22 of FIG. 1. The shaft wall 22 comprises two parallel guide rails 28, 30 co-acting with corresponding car guides 32, 34. Each car guide 32, 34 has a set of guide rollers co-acting with the car guide rails 28, 30. As these car guides 32, 34 in connection with the car guide rails 28, 30 are configured for a rucksack type suspension, the corresponding guide system 28, 30, 32, 34 is configured to keep the car 16 horizontally in connection with the shaft wall 22 as these both car guide rails 28, 30 are the only guide rails of the elevator car 16 in the shaft 12. The vertical stator beams 18 as well as the movers 24, 26 of the elevator car 16 are shown in more detail in FIG. 3. Generally, guide rails with a round cross-section may be used which are surrounded by rollers of the car guide, thereby fixing the car horizontally in connection with the guide rail.

[0059] According to FIG. 3 the vertical stator beam 18 comprises a metal support structure 40 with a square cross-section. On each side the support structure 40 carries a metal stator rod 50 comprising stator teeth 52, which form the four side faces 42, 44, 46, 48 of the stator beam 18. Each of these stator rods (or bars) 50 with the stator teeth 52 forms a stator of the linear motor 14 so that the stator beam 18 shown in FIG. 3 comprises four stators. The stator teeth 52 co-act with windings 74, 76 (FIG. 4) and mover irons 70,72 and permanent magnets 71 located along counter-faces 54 in the four arms 56, 58, 60, 62 of the C-type profile of the mover 24, 26. This C-type profile of the mover surrounds the stator beam 18 but leaves an opening 64 for the adaption of the fastening elements 20, as the mover 24, 26 travels along the shaft 12.

[0060] The stator rods 50 on all four side faces 42, 44, 46, 48 have the same pitch d. Anyway, the first and third side face 42, 46 of the stator beam also have an identical teeth position in vertical direction whereas the second and fourth side face 44, 48 have the same pitch but the teeth position is vertically offset with respect to the stator teeth 52 on the first and third side face 42, 46 by a pitch.

[0061] Via this arrangement, it is ensured that on one hand, the horizontal forces between the stators 50 on opposite sides eliminate each other whereas the vertical offset of the pitches of the side faces oriented rectangular leads to a better efficiency and a smoother run of the elevator motor, as a moving step of such a motor 14 is a half pitch. By the fact that four stators 50 are located within the stator beam 18 the force generated between the movers 24, 26 and the stator beam 18 is multiplied by four, thereby achieving less horizontal ripples and a smoother movement of the movers 24, 26 with respect to the vertical stator beam 18.

[0062] FIG. 4 shows the operation principle of the flux switching permanent magnet motor formed by the movers 24, 26 and the stators 50a in the stator beam 18. The stator 50a comprises a stator rod 51 which, preferably as a one-piece part comprises stator teeth 52a which are spaced apart by teeth gaps 53. The pitch d of the stator teeth 52 is identical throughout the length of the stator rod 50. The stator teeth 52a are pointing downwards with respect to the horizontal plane with an acute angle . The angle with respect to the longitudinal direction of the stator rod 51a is 90. Via this measure the magnetic field generated between stator and mover produces a pulling force on the mover in upwards directions which facilitates the carrying of the car weight against the gravitational force.

[0063] The stator 50a in the stator beam 18 in a longer vertical shaft 12 can be comprised of one single stator rod 50 with a corresponding length or by several stator rod parts located one above each other end-to-end, according to the required shaft length. In the connecting areas of stator rod parts located end-to-end above each other the pitch d has to be maintained.

[0064] The mover 24, 26 comprises on each counter face 54 a succession of two mover irons 70, 72 between which one thin magnet 71 is located. This package of mover irons 70, 72 and magnet 71 is followed by two windings 74, 76 which are controlled as to produce a magnetic field with opposite direction. This succession 70, 71, 72, 74, 76 of mover irons, permanent magnets and windings is repeated according to the length of the mover. The movement of the mover 24, 26 with respect to the stator rod is accomplished by controlling the both windings 74, 76 to switch the flux direction to the opposite so that with each switching, the mover 24, 26 moves half of the pitch d of the stator teeth 52. Thus, the mover 24, 26 can be controlled to move according to the arrows in upwards or downwards direction with respect to the stator rod 50.

[0065] FIG. 5 shows a second embodiment of a stator 50b with a stator rod 51b carrying rounded stator teeth 52b extending to the mover in a pitch d, separated by teeth gaps 53. Of course, the ratio of pitch d and the tooth gap 53 may vary from the drawing, particularly being larger than shown. The rounded stator teeth 52b better match the flux lines of the generated magnetic field and lead to a more economical motor design. The tip 55 of the teeth 52b is pointing downwards in an angle so as to provide a better pulling force on the mover against the gravitational force.

[0066] FIG. 6 shows a third embodiment of a stator 50c with a stator rod 51 carrying stator teeth 52c which are connected to the rod 51, preferably as a single piece via an extended base portion 90 with a wider width w2 followed by the downwards directed top portion 95 of the tooth 52c with a smaller width w1. The stator teeth gaps 53 are preferably filled with a polymer material to reduce the collecting of dirt in the gaps 53.

[0067] On the other side the mover 24, 26 has mover teeth 80 formed by two armature irons 82, 84 embedding a core magnet 86. The gaps 87 between the mover teeth 80 is at least partially filled with an armature winding. The drawing shows the magnetic flux lines of this motor arrangement. By the form and the orientation of the downwards directed stator teeth 52c the generated magnetic field exerts a pulling force in upwards direction to the mover against the car weight so that this arrangement is optimized to carry the car weight with less of armature material on the stator as well as on the mover side.

[0068] FIG. 7 shows an elevator 100 having two elevator shafts 102, 104 which are connected by an upper horizontal passage 106 at the top end of both shafts 102, 104 as well as a lower horizontal passage 108 at the bottom end of both elevator shafts 102, 104. Thus, the both elevator shafts 102, 104 with the upper and lower horizontal passage 106, 108 form a closed loop whereby the movement of the elevator cars 16a-16d is only allowed in one direction according to the arrows shown in the figure. By this measure it is ensured that cars run only in one direction in each of the shafts which lead to a higher transport capacity and to an easier control of the cars in the shaft.

[0069] In both elevator shafts 102, 104, vertical stator beams 18, 114 e.g. according to one of the previous embodiments, or according to FIG. 7 are located which co-act with movers 24, 26 located at the elevator cars 16a-16d. Each shaft 102, 104 may comprise preferably two, three or four parallel stator beams 18, 114. The figure shows landing doors 110 located in the first elevator shaft 102 as well as in the second elevator shaft 104. The cars 16a-16d are horizontally moved in the horizontal passages 106, 108 in a not specified manner by horizontal moving mechanisms.

[0070] The inventive elevator concept is preferably designed for high-rise elevators having 20 floors or more. Accordingly, the two shafts 102, 104 are able to accommodate a much larger number of elevator cars than the four cars 16a-16d shown in the figure. Each car 16a-16d is able to move largely independent of the others within the two shafts 102, 104 except the fact that collisions between cars have to be avoided. By the fact that in the first elevator shaft 102 the elevator cars 16a-16d only drive downwards and in the second elevator shaft 104 only drive upwards, the probability of mutual affection is decreased. Furthermore, by this circular moving scheme, the transport capacity of both shafts is drastically increased on one hand because now the two elevator shafts may comprise much more elevator cars than in conventional systems and on the other hand, because in each elevator shaft, all elevator cars only move in the same direction, avoiding counter-movements of cars which reduce an economic shaft use and necessitate extensive anti-collision control.

[0071] It is not shown in the figures but is evident for the skilled person that the elevator car has a gripping device which grips the guide faces of guide rails or of the vertical stator beams 114 when the power of the power source (and eventually in case of a power failure of the mains) goes off thus ensuring that the car cannot fall downwards when the movers are not energized any longer.

[0072] Accordingly, also in this new multi-shaft multi-car arrangement of the invention, the safety of the elevator cars 16a-16d is always ensured independent whether the car is currently supported by the movers 126 and the vertical stator beams 114 or by any optional support rollers of the elevator car on horizontal guide tracks located in the horizontal passages 106, 108.

[0073] The invention can be carried out within the scope of the appended patent claims. Thus, the above-mentioned embodiments should not be understood as delimiting the invention.

LIST OF REFERENCE NUMBERS

[0074] 10 elevator [0075] 12 elevator shaft [0076] 14 elevator motor [0077] 16 elevator car [0078] 18 stator beam [0079] 20 fastening elements [0080] 22 shaft wall/shaft side [0081] 24 lower mover [0082] 26 upper mover [0083] 28 first guide rail [0084] 30 second guide rail [0085] 32 first car guide [0086] 34 second car guide [0087] 40 support structure [0088] 42 first side face [0089] 44 second side face [0090] 46 third side face [0091] 48 fourth side face [0092] 50 stator [0093] 51 stator rod [0094] 52 stator teeth [0095] 53 teeth gaps [0096] 54 counter face of mover [0097] 56 first arm of C-profile mover [0098] 58 second arm of C-profile mover [0099] 60 third arm of C-profile mover [0100] 62 fourth arm of C-profile mover [0101] 70 first mover iron [0102] 71 permanent magnet [0103] 72 second mover iron [0104] 74 first winding [0105] 76 second winding [0106] 80 mover teeth [0107] 82 upper armature iron [0108] 84 lower armature iron [0109] 86 core magnet of the mover teeth [0110] 87 mover tooth gap with armature winding [0111] 88 stator rod vertically extending stator part [0112] 90 base teeth portion [0113] 92 top teeth portion [0114] 100 elevator (second embodiment) [0115] 102 first elevator shaft [0116] 104 second elevator shaft [0117] 106 upper horizontal passage [0118] 108 lower horizontal passage [0119] 110 landing door [0120] 114 stator beam (second embodiment) [0121] W1 width 1 of the downwards oriented top portion [0122] W2 width 2 of the base portion when meeting the stator rod [0123] downwards tilting angle of the stator teeth or of their top portion [0124] 15