ELEVATOR SYSTEM

Abstract

An elevator system (2) comprises an elevator car (10) configured for traveling within a hoistway (4) between a plurality of landings (8); and at least one energy harvesting device (20) attached to the elevator car (10). The at least one energy harvesting device (20) is configured for converting mechanical energy, in particular kinetic energy, into electric energy.

Claims

1. Elevator system (2) comprising: an elevator car (10) configured for traveling within a hoistway (4) between a plurality of landings (8); and at least one energy harvesting device (20) provided at the elevator car (10); the at least one energy harvesting device (20) is configured for converting mechanical energy, in particular kinetic energy, into electric energy.

2. Elevator system (2) according to claim 1, wherein the at least one elevator car (10) comprises at least one movable elevator car door (12), and wherein the at least one energy harvesting device (20) attached to the at least one movable elevator car door (12).

3. Elevator system (2) according to claim 1, wherein the at least one energy harvesting device (20) is a capacitive energy harvesting device (20) comprising at least one piezoelectric element (38).

4. Elevator system (2) according to claim 1, wherein the at least one energy harvesting device (20) is an inductive energy harvesting device (20) comprising at least one permanent magnet (26) movably arranged within at least one electric coil (24).

5. Elevator system (2) according to claim 4, wherein the at least one permanent magnet (26) is or is comprised in a movable element (27), in particular a rolling element, movably arranged within a casing (22).

6. Elevator system (2) according to claim 5, wherein the at least one energy harvesting device (20) comprises at least one reflector (25a, 25b), in particular at least one elastic reflector (25a, 25b), provided an end of the casing (22) and configured for reflecting the movable element (27) towards a central portion of the casing (22).

7. Elevator system (2) according to claim 4, wherein at least one elastic element (28a, 28b), in particular a spring, is mounted to the at least one movable element (27), and the at least one movable element (27) is movable by compressing and/or expanding the at least one elastic element (28a, 28b).

8. Elevator system (2) according to claim 7 comprising two elastic elements attached to opposing ends of the at least one movable element (27).

9. Elevator system (2) according to claim 4, wherein the at least one permanent magnet (26) comprises neodymium.

10. Elevator system (2) according to claim 1, wherein the at least one energy harvesting device (20) is configured for generating electric energy when moved, accelerated and/or decelerated in a horizontal and/or in a vertical direction.

11. Elevator system (2) according to claim 1, wherein the at least one energy harvesting device (20) is electrically connected to an electric circuit (30) comprising at least one electric rectifier (32), in particular at least one semiconductor diode.

12. Elevator system (2) according to claim 11, wherein the electric circuit (30) comprises an electric storage device (34) configured for storing the electric energy generated by the at least one energy harvesting device (20).

13. Elevator system (2) according to claim 1, wherein the at least one elevator car (10) comprises at least one sensor device (18), and wherein the at least one energy harvesting device (20) is configured for supplying electric energy to the at least one sensor device (18).

14. Elevator system (2) according to claim 1, wherein the at least one energy harvesting device (20) has the shape of a cylinder with outer dimensions corresponding to the outer dimensions of a standard battery cell (40), in particular of one of an A-battery cell, AA-battery cell and a AAA-battery cell.

15. Energy harvesting device (20) configured for converting mechanical energy, in particular kinetic energy, into electric energy, wherein the at least one energy harvesting device (20) has the shape of a cylinder or a coin, with outer dimensions of the at least one energy harvesting device (20) corresponding to the outer dimensions of a coin cell battery (42) or of a standard battery cell (40), in particular of one of an A-battery cell, a AA-battery cell, and a AAA-battery cell.

Description

DRAWING DESCRIPTION

[0031] In the following, exemplary embodiments of the invention are described in more detail with respect to the enclosed figures:

[0032] FIG. 1 schematically depicts an elevator system in which an energy harvesting device according to an exemplary embodiment of the invention may be employed.

[0033] FIG. 2 schematically shows an energy harvesting device according to an exemplary embodiment of the invention.

[0034] FIG. 3 schematically shows an energy harvesting device according to another exemplary embodiment of the invention.

[0035] FIG. 4 schematically shows an energy harvesting device according to yet another exemplary embodiment of the invention.

[0036] FIG. 5 schematically shows an energy harvesting device having the shape of a standard battery cell.

[0037] FIG. 6 schematically shows an energy harvesting device having the shape of a standard coin cell battery.

DETAILED DESCRIPTION

[0038] FIG. 1 schematically depicts an elevator system 2 in which an elevator brake 20 according to an exemplary embodiment of the invention may be employed.

[0039] The elevator system 2 includes an elevator car 10 movably arranged within a hoistway 4 extending between a plurality of landings 8. The elevator car 10 in particular is movable along a plurality of car guide members 14, such as guide rails, extending along the vertical direction of the hoistway 4. Only one of said car guide members 14 is visible in FIG. 1.

[0040] Although only one elevator car 10 is depicted in FIG. 1, the skilled person will understand that exemplary embodiments of the invention may include elevator systems 2 having a plurality of elevator cars 10 moving in one or more hoistways 4.

[0041] The elevator car 10 is movably suspended by means of a tension member 3. The tension member 3, for example a rope or belt, is connected to an elevator drive 5, which is configured for driving the tension member 3 in order to move the elevator car 10 along the height of the hoistway 4 between the plurality of landings 8, which are located on different floors.

[0042] Each landing 8 is provided with a landing door 11, and the elevator car 10 is provided with a corresponding elevator car door 12 for allowing passengers to transfer between a landing 8 and the interior of the elevator car 10 when the elevator car 10 is positioned at the respective landing 8.

[0043] The exemplary embodiment of the elevator system 2 shown in FIG. 1 employs a 1:1 roping for suspending the elevator car 10. The skilled person, however, easily understands that the type of the roping is not essential for the invention and that different kinds of roping, e.g. a 2:1 roping, may be used as well. The elevator system 2 may have a machine room or may be a machine room-less elevator system. The elevator system 2 may use a tension member 3, as it is shown in FIG. 1, or it may be an elevator system without a tension member 3. The elevator drive 5 may be any form of drive used in the art, e.g. a traction drive, a hydraulic drive or a linear drive.

[0044] The elevator system 2 shown in FIG. 1 further includes a counterweight 19 attached to the tension member 3 and moving concurrently and in opposite direction with respect to the elevator car 10 along at least one counterweight guide member 15. The skilled person will understand that the invention may be applied also to elevator systems 2 which do not comprise a counterweight 19.

[0045] The tension member 3 may be a rope, e.g. a steel wire rope, or a belt. The tension member 3 may be uncoated or may have a coating, e.g. in the form of a polymer jacket. In a particular embodiment, the tension member 3 may be a belt comprising a plurality of polymer coated steel cords (not shown). The elevator system 2 may have a traction drive including a traction sheave for driving the tension member 3.

[0046] The elevator drive 5 is controlled by an elevator control 6 for moving the elevator car 10 along the hoistway 4 between the different landings 8.

[0047] Input to the elevator control 6 may be provided via landing control panels 7a, which are provided on each landing 8 in the vicinity the landing doors 11, and/or via an elevator car control panel 7b provided inside the elevator car 10.

[0048] The landing control panels 7a and the elevator car control panel 7b may be connected to the elevator control 6 by means of electric wires, which are not shown in FIG. 1, in particular by an electric bus, such as a field bus/CAN-bus, or by means of wireless data connections.

[0049] The elevator car 10 is equipped with a sensor device 18, which for example may include a position sensor and/or a speed sensor configured for detecting the position and/or the speed of the elevator car 10, respectively. In one embodiment, the sensor device 18 may be located at any desired location in the hoistway 4 or on the elevator equipment.

[0050] The sensor device 18 may be configured for wireless data transmission in order to allow transmitting data from the sensor device 18 to the elevator control 6 without providing a wire connection between the sensor device 18 and the elevator control 6.

[0051] The elevator car 10 is further equipped with an energy harvesting device 20. The energy harvesting device 20 is configured for generating electric energy, which is supplied to the sensor device 18 in order to allow operating the sensor device 18 without connecting the sensor device 18 to an external power supply.

[0052] The harvesting device 20 in particular is configured for converting kinetic energy of the elevator car 10 and/or kinetic energy of the elevator car door 12 into electric energy. In one embodiment, the harvesting device 20 may be located at any desired location in the hoistway 4 or on the elevator equipment.

[0053] The energy harvesting device 20 allows operating the sensor device 18 without running an electric cable to the sensor device 18 for delivering electric power to the sensor device 18. In contrast to conventional batteries, an energy harvesting device 20 according to an exemplary embodiment of the invention does not run out of power but has a long lifetime. In consequence, the need for maintenance is considerably reduced.

[0054] FIG. 2 schematically shows an energy harvesting device 20 according to an exemplary embodiment of the invention.

[0055] The energy harvesting device 20 comprises a movable element 27 including a permanent magnet 26 arranged in a cylindrical electric coil 24. For providing a strong permanent magnet, the permanent magnet 26 may comprise neodymium, it in particular may comprise NdFeB.

[0056] The movable element 27 is supported by two elastic elements 28a, 28b, such as springs, in particular spiral springs, allowing the movable element 27 to move, in particular to oscillate, in a linear motion along a central axis A of the cylindrical electric coil 24 by alternatingly compressing and expanding the elastic elements 28a, 28b.

[0057] The movable element 27 and the elastic elements 28a, 28b may be accommodated in a casing 22 in order to be protected from external influences. The casing 22 in particular may have the shape of a tube, in particular a cylindrical tube, extending along the central axis A through the center of the electric coil 24.

[0058] The ends of the cylindrical coil 24 are electrically connected by electric wires 29a, 29b to a rectifying and storage circuit 30.

[0059] The rectifying and storage circuit 30 comprises an electric rectifier 32, which may include at least one semiconductor diode, and a storage device 34 including a capacitor, a combination of capacitors and/or at least one supercap.

[0060] When the energy harvesting device 20 is accelerated or decelerated along the central axis A of the electric coil 24, the movable element 27 starts to move relatively to the electric coil 24 due to its inertia. In combination with the elastic forces provided by the elastic elements 28a, 28b, which are deformed (compressed or expanded) by the movement of the movable element 27, the movable element 27 starts oscillating along the axial direction, the permanent magnet 26 inducing an oscillating electric voltage within the electric coil 24.

[0061] The induced electric voltage causes an electric current to flow through the electric wires 29a, 29b connected to the ends of the electric coil 24. Said electric current is rectified by the electric rectifier 32 and stored within the storage device 34.

[0062] The electric energy stored within the storage device 34 may be supplied to the sensor device 18 for operating the sensor device 18.

[0063] In an energy harvesting device 20 according to an exemplary embodiment of the invention, the storage device 34 is charged with electric energy every time the elevator car 10 is accelerated or decelerated.

[0064] The energy harvesting device 20 may be attached to the elevator car 10 in a configuration in which the central axis A of the electric coil 24 is oriented in a vertical direction in order to allow for an efficient conversion of the mechanical energy of the vertically moving elevator car 10.

[0065] Alternatively or additionally, an energy harvesting device 20 according to an exemplary embodiment of the invention may be attached to the elevator car door 12, in particular to a panel of the elevator car door 12, in a configuration in which the central axis A of the electric coil 24 is oriented in a horizontal direction for converting the mechanical energy of the (horizontally) moving elevator car door 12 when the elevator car door 12 is opened and/or closed. In one embodiment, the energy harvesting device 20 may be attached to the counterweight 19 or any other moving portion of the elevator system.

[0066] In another configuration, the central axis A of the electric coil 24 may be oriented diagonally in order to allow converting mechanical energy of the vertically moving elevator car 10 as well as mechanical energy of the horizontally moving panel(s) of the elevator car door 12.

[0067] In yet another configuration, the movable element 27 may be supported, e.g. by a plurality of elastic elements 28a, 28b, such that it is movable in two or three dimensions.

[0068] The energy harvesting device 20 is configured so that sufficient electric energy is generated and stored in the course of normal operation of the elevator system 2. As a result, the sensor device 18 may be operated continuously without supplying external electric power to the sensor device 18 or to the storage device 34.

[0069] In consequence, the sensor device 18 may be operated over the lifetime of the elevator system 2 without externally recharging the storage device 34. As a result, the energy harvesting device 20 does not considerably contribute to the costs for maintaining the elevator system 2.

[0070] FIG. 3 schematically depicts an alternative exemplary embodiment of an energy harvesting device 20.

[0071] In the embodiment depicted in FIG. 3, the movable element 27 including the permanent magnet 26 has the shape of a rolling element, such as a roller or a ball, which is rollably supported within the casing 22. The casing 22 in particular may be formed as a tube. Two reflectors 25a, 25b, in particular elastic reflectors 25a, 25b, are provided at the ends of the casing 22 and configured for reflecting the movable element 27 from the ends towards the center of the casing 22.

[0072] As in the embodiment depicted in FIG. 2, the casing 22 is surrounded by an electric coil 22, which is electrically connected via electric wires 29a, 29b to a rectifying and storage circuit 30. The rectifying and storage circuit 30 corresponds to the rectifying and storage circuit 30 depicted in FIG. 2, therefore it is not discussed in detail again.

[0073] When the casing 22 is accelerated or decelerated along the central axis A of the electric coil 24, the movable element 27 starts moving and oscillating between the two reflectors 25a, 25b causing the permanent magnet 26 to induce an (oscillating) electric voltage within the electric coil 24, as it has been described with reference to the embodiment depicted in FIG. 2.

[0074] The embodiment depicted in FIG. 3 is well suited for a horizontal orientation of the casing 22, in particular for an energy harvesting device 20 attached to the horizontally moving panel(s) of the elevator car door 12.

[0075] FIG. 4 schematically depicts yet another exemplary embodiment of an energy harvesting device 20.

[0076] The energy harvesting device 20 depicted in FIG. 4 comprises a piezoelectric element 38 and a mechanical mass 36 mechanically connected to or formed integrally with the piezoelectric element 38.

[0077] The piezoelectric element 38 comprises two electrodes 38a, 38b and a piezoelectric layer 38c sandwiched between the two electrodes 38a, 38b.

[0078] When the mechanical mass 36 is accelerated or decelerated, e.g. since the elevator car 10 and/or a panel of the elevator car door 12 is accelerated or decelerated, the inertia of the mass 36 causes the piezoelectric layer 38c to compress or to expand. Compression and expansion of the piezoelectric layer 38c generate an electric voltage between the two electrodes 38a, 38b.

[0079] Said electric voltage causes an electric current to flow within the electric wires 29a, 29b connected to the electrodes 38a, 38b. Said electric current is supplied to a rectifying and storage circuit 30 from where it is delivered to the sensor device 18, as it has been described for the previous exemplary embodiments depicted in FIGS. 2 and 3.

[0080] An energy harvesting device 20 comprising a piezoelectric element 38 may be mounted to the elevator car 10 in any orientation, in particular including a vertical orientation, which is beneficial for being activated by vertical acceleration and deceleration of the elevator car 10, a horizontal orientation, which is beneficial for being activated by horizontal acceleration and deceleration of elevator car door panels, and a diagonal orientation, which allows activating the piezoelectric element 38 by both, vertical and horizontal acceleration and deceleration.

[0081] Although only one energy harvesting device 20 is depicted in FIG. 1, the skilled person understands that a plurality of energy harvesting devices 20 may arranged at the same elevator car 10. In particular, in case of a plurality of sensor devices 18, each sensor device 18 may be provided with its own energy harvesting device 20 in order to allow for an autonomous operation of the respective sensor device 18. Further, each sensor device 18 may be provided with two or more energy harvesting devices 20 in order to enhance the operational safety of the sensor device 18 due to redundancy.

[0082] For clarity of illustration, the depiction of the rectifying and storage circuit 30 in FIGS. 2 to 4 is not on scale. The skilled person understands that the rectifying and storage circuit 30 usually is much smaller than depicted in FIGS. 2 to 4. The rectifying and storage circuit 30 in particular may be integrated with the casing 22 and/or the electric coil 24 for forming a compact energy harvesting device 20.

[0083] The energy harvesting device 20 may be designed as a cylinder having outer dimensions corresponding to the outer dimensions of a standard battery cell 40 as it is depicted in FIG. 5. The energy harvesting device 20 in particular may have the dimensions of one of an A-battery cell, AA-battery cell and a AAA-battery cell, or any other standardized battery cell.

[0084] Alternatively, the energy harvesting device 20 may be designed as a coin cell battery 42, such as a CR2032 coin cell battery 42. An example of a coin cell battery 42 is depicted in FIG. 6.

[0085] Such a design allows replacing a standard battery cell 40 in any electric device by an energy harvesting device 20 according to an exemplary embodiment of the invention without redesigning the electric device.

[0086] The use of energy harvesting devices 20 according to exemplary embodiments of the invention is not restricted to elevator systems 2. Instead, energy harvesting devices 20 according to exemplary embodiments of the invention may be employed as reliable and maintenance-free electric energy supplies for any kind of electric devices which are regularly accelerated and/or decelerated.

[0087] While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adopt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention shall not be limited to the particular embodiment disclosed, but that the invention includes all embodiments falling within the scope of the dependent claims.

REFERENCES

[0088] 2 elevator system [0089] 3 tension member [0090] 4 hoistway [0091] 5 drive [0092] 6 elevator control [0093] 7a landing control panel [0094] 7b elevator car control panel [0095] 8 landing [0096] 10 elevator car [0097] 11 landing door [0098] 12 elevator car door [0099] 14 car guide member [0100] 15 counterweight guide member [0101] 19 counterweight [0102] 20 energy harvesting device [0103] 22 casing [0104] 24 electric coil [0105] 25a, 25b reflectors [0106] 26 permanent magnet [0107] 27 movable element [0108] 28a, 28b elastic elements [0109] 29a, 29b electric wires [0110] 30 rectifying and storage circuit [0111] 32 electric rectifier [0112] 34 storage device [0113] 36 mass [0114] 38 piezoelectric elements [0115] 38a, 38b electrodes [0116] 38c piezoelectric layer [0117] 40 battery cell