TRANSPORTATION DEVICE COMPRISING A SAFETY DEVICE FOR LIMITING DECELERATION

Abstract

A transportation device such as an elevator installation, an escalator, or a moving walkway may comprise a person conveying unit and an electromagnetic linear drive for driving the person conveying unit. The electromagnetic linear drive may include a stator segment and a runner element. The runner element can be driven by the force of an electromagnetic field of the stator segment in a first drive direction or in an opposite second drive direction. The runner element is movably mounted on the person conveying unit such that a magnetic resistance in an air gap between the stator segment and the runner element is adjustable depending on a drive force acting between the stator segment and the runner element.

Claims

1.-19. (canceled)

20. A transportation device comprising: a person conveying unit; and an electromagnetic linear drive for driving the person conveying unit, the electromagnetic linear drive including a stator segment, and a runner element, wherein the runner element is configured to be driven by an electromagnetic field of the stator segment in a first drive direction or in a second drive direction opposite the first drive direction, wherein the runner element is movably mounted on the person conveying unit such that a magnetic resistance in an air gap between the stator segment and the runner element is adjustable depending on a drive force acting between the stator segment and the runner element.

21. The transportation device of claim 20 wherein the runner element is movably mounted between a first position and a second position.

22. The transportation device of claim 21 wherein the magnetic resistance in the air gap is smaller in the first position than in the second position.

23. The transportation device of claim 21 wherein the runner element is mounted such that the runner element is forced into the first position when the drive force acts in the first drive direction.

24. The transportation device of claim 21 wherein the runner element is mounted such that the runner element is forced into the second position when the drive force acts in the second drive direction.

25. The transportation device of claim 24 wherein the drive force present between the stator segment and the runner element is solely responsible for forcing the runner element into the second position.

26. The transportation device of claim 20 wherein the runner element is movable in a direction that is transverse to the first and second drive directions.

27. The transportation device of claim 20 wherein the runner element is configured to be displaced or swiveled in a straight line.

28. The transportation device of claim 20 comprising a safety device that moves the runner element out of a field of force of the stator segment upon a change in the drive direction above a predetermined acceleration value or deceleration value, by a self-acting mechanical constraining force.

29. The transportation device of claim 28 wherein the runner element is movably mounted on a runner by way of the safety device between a first position and a second position such that a mounting has elements coordinated with each other that permit relative movements between the runner element and the runner with one or more predetermined mechanical degrees of freedom and that perform the relative movements by mechanical constraining forces.

30. The transportation device of claim 28 wherein the runner element is mounted on a runner by way of the safety device between a first position and a second position such that a mounting has at least one breaking point that can be separated upon exceeding predetermined acceleration forces or deceleration forces.

31. The transportation device of claim 30 wherein the runner element includes at least two parallel oblong holes disposed at an acute angle to a direction of movement of the runner, wherein the runner is displaceably mounted by at least two spaced-apart bolts in the two parallel oblong holes such that the runner element upon reaching or exceeding a preset deceleration of the runner element is moved away from the stator segment by a displacement in the two parallel oblong holes and is moved out from the electromagnetic field of the stator segment.

32. The transportation device of claim 30 wherein the runner includes at least two parallel oblong holes disposed at an acute angle to a direction of movement of the runner, wherein the runner element is displaceably mounted by at least two spaced-apart bolts in the two parallel oblong holes such that the runner element upon reaching or exceeding a preset deceleration of the runner element is moved away from the stator segment by a displacement in the two parallel oblong holes and is moved out from the electromagnetic field of the stator segment.

33. The transportation device of claim 32 wherein the preset deceleration of the runner element during upward travel corresponds at most to gravitational acceleration.

34. The transportation device of claim 20 wherein the runner element is disposed on a runner by way of rotating arms.

35. The transportation device of claim 20 wherein the runner element is a permanent magnet runner element.

36. The transportation device of claim 20 wherein a mounting of the runner element has an end position.

37. The transportation device of claim 20 wherein a mounting of the runner element has damper elements.

38. The transportation device of claim 20 wherein a mounting of the runner element has restoring elements that force the runner element into the first position upon loss of force.

39. The transportation device of claim 20 wherein the runner element is movable in a direction that forms an angle of between 15 and 30 degrees relative to the first and second drive directions.

Description

DESCRIPTION OF THE FIGURES

[0038] FIG. 1 shows as an example of a transportation device an elevator installation designed with a first preferred embodiment of the linear drive according to the invention.

[0039] FIG. 2 shows as a further example of a transportation device an elevator installation designed with another preferred embodiment of the linear drive according to the invention.

[0040] FIG. 3 displays the increasing of the magnetic resistance by decreasing the cross section area of the air gap.

[0041] FIG. 4 displays the increasing of the magnetic resistance by increasing the length of the air gap.

DETAILED DESCRIPTION OF THE DRAWINGS

[0042] In FIG. 1, an elevator installation as the transportation device according to the invention is shown schematically and designated overall as 100. The elevator installation 100 comprises, as the person conveying unit, an elevator car 71, which can move vertically in an elevator shaft 90 in the upward direction 91 and downward direction 92. Likewise, though not shown in detail, the transportation device may be a moving walkway or an escalator with a platform 71 as the person conveying unit.

[0043] The elevator installation 100 is designed with a linear drive 80. This comprises at least one stator 10 and at least one runner 70, each stator 10 having at least one stator segment 20 and each runner 70 having at least one runner element 30. Each stator segment 20 has a separate stator winding 22, whereby a possible winding short circuit in this stator winding can be indicated by a switch 23. The runner element 30 is preferably designed as a permanent magnet. A squirrel-cage runner or a runner with a runner winding would also be conceivable. Between the stator segment 20 and the runner element 30 there stretches an air gap 21 with an air gap length. In the schematic representation, four stator segments 20 are shown, only one of which is provided with more detailed reference numbers.

[0044] The problem in such linear drives, besides a mechanical damaging of the runner, is the possibility of a winding short circuit in a stator winding. Similar to the principle of action of an eddy current brake, a runner moving with respect to the stator winding induces in this case an induction voltage and, because of a short-circuited stator winding, an induction current, whose magnetic force action by Lenz' rule works against the induction source and greatly decelerates the movement of the runner and thus of the elevator car. A defect in the inverter may also bring about a spontaneous reversal of the drive force and thus a massive deceleration. This deceleration may represent a danger in the case of fast speeds of travel.

[0045] A safety device 40 of the electromagnetic linear drive 80 according to the invention should therefore intervene when at least one runner element 30 reaches or exceeds a preset deceleration especially during upward travel due to an electrical or mechanical fault upon passing over a stator segment 20.

[0046] The safety device 40 enables a guided movable mounting of the runner element 30 on the runner 70. For this, the runner element 30 can basically move between a first position 61 and a second position 62. The two positions 61, 62 are shown schematically in detail relative to each other at the left margin of the image in FIG. 1. In the first position 61, the runner element is situated closer to the stator 10 and thus is exposed much more strongly to the magnetic influence of the stator than in the second position 62.

[0047] As shown in FIG. 1, in this embodiment an arrangement of spaced-apart bolts 60 on the runner element 30 engages with a correspondingly spaced-apart arrangement of parallel oblong holes 50 on the runner 70 and can be displaced in parallel in them. The parallel oblong holes 50 enable a guided movement of the runner element 30 with respect to the runner 70. The oblong holes 50 are arranged at an acute angle to the direction of movement of the runner 70, so that a displacement of the runner element 30 opposite the direction of movement of the runner 70 moves the runner element 30 away from the stator segment 20 diagonally to the direction of movement of the runner 70, so that the magnetic force action is interrupted or at least greatly reduced in the direction of movement of the runner 70. The bolts 60 can be arranged both on the runner 70 and on the runner element 30, if the other respective element has the correspondingly spaced-apart oblong holes 50.

[0048] The angle of the parallel oblong holes 50 with respect to the direction of movement of the runner 70 should be chosen advantageously such that, on the one hand, a sufficient transverse movement occurs in order to move the runner element 30 out from the force field, yet on the other hand the constraining force is sufficient to move the runner element 30 against the transversal component of the magnetic force out from the field of the stator segment 20. An angle between 5 and 45 degrees is proposed, especially between 15 and 30 degrees.

[0049] Thanks to the moving of the runner element 30 from the first position to the second position, the action of the force between the runner element 30 and the stator segment 20 in the direction of movement of the runner 70 is interrupted or at least reduced so much that a strong deceleration of the elevator car 71 can no longer be produced. Given a suitable design of the linear drive, the elevator car 71 can continue its travel with the remaining stator segments. Advantageously, furthermore, restoring elements 120 are arranged on the runner elements 30, which can place the runner elements 30 back in the oblong holes 50 once the faulty stator segment 20 has been passed over and/or there is no forcing of the runner element 30 into the second position.

[0050] FIG. 2 shows a schematic representation of another elevator installation 100 with an elevator car 71, which can move in an elevator shaft 90. The same parts as have already been described in connection with FIG. 1 are given the same reference numbers and will not be mentioned again individually. In this exemplary embodiment, the runner element 30 is swivel-mounted on the runner 70. The movement of the runner element 30 in relation to the stator segment 20 is made possible by an arrangement of parallel rotating arms 130, which swivel the runner element 30 out from the magnetic force field in event of a fault by means of rotary bearings 140 arranged on the runner 70 and on the runner element 30 and interrupt the action of the force. Advantageously, the rotary bearings 140 have an end position 110, which may be arranged for example on the bottom plate of the runner 70. FIG. 2 shows the runner element 30 in the first position; the second position is not drawn here explicitly; in the second position, the runner element 30 is swiveled away downward clockwise, so that the distance from the stator segment is increased.

[0051] The length of the rotary arms 130 may also be different and instead of a parallelogram it may represent a general rectangle, so that besides the swivel movement there is an additional rotation of the runner element 30. Likewise, rotational devices and displacement devices, especially rotating arms, oblong holes, rails and bolts can be combined with each other, for example by having rotary bearings interacting with oblong holes in the shape of a circle segment.

[0052] Advantageously, damper elements 120 and restoring elements 121 are additionally arranged in the rotary bearings 140 or on the rotating arms 130 (see FIG. 1).

[0053] A holding system with a predetermined breaking point is also conceivable. In order not to lose the component after a breakage at the predetermined breaking point, the component could be secured by a steel cable. In place of a predetermined breaking point, a latch with roller spring pressure element could also be used. This approach is advantageous in the case of moving walkways.

[0054] FIG. 3 explains schematically the possibility of increasing the magnetic resistance. FIG. 3a shows schematically the stator segment 20 and the runner unit 30. The stator segment 20 has a U-shaped receiving space, with which the runner element 30 engages. F indicates the direction of the magnetic flux. Thanks to the specific overlapping between stator segment 20 and runner element 30, an air gap length l and a cross section area A of the air gap 21 are produced. The air gap 21 and air gap length l here are understood to be the sum of the regions or partial lengths shown on the left and right of the runner element. FIG. 3a shows the runner unit in the first position. By a corresponding mounting, the runner unit 30 can be moved to a second position, as shown in FIG. 3b. The air gap length l will remain unchanged, although the cross section area A is significantly reduced.

[0055] FIG. 4 shows schematically a further possibility for increasing the magnetic resistance. FIG. 4a shows schematically the stator segment 20 and the runner unit 30. The stator segment 20 is arranged parallel to the runner element 30. Thanks to the specific arrangement between the stator segment 20 and the runner element 30, an air gap length l and a cross section area A of the air gap 21 are produced. FIG. 4a shows the runner unit in the first position. By a corresponding mounting, the runner unit 30 can be moved to a second position, as shown in FIG. 4b. The air gap length l will be significantly increased; the cross section area A of the air gap remains largely unchanged.

[0056] It is basically critical that the movement from the first position to the second position takes place in a direction other than the drive direction, in particular with at least one directional component transversely to the drive direction. In the present instance of FIGS. 3 and 4, the drive direction is parallel to the z-direction, but the runner element 30 is moved parallel to the y-direction. Of course, the runner element 30 may also additionally be moved parallel to the z-direction.