The present invention relates in general to elevators. In particular, however not exclusively, the present invention concerns a linear motor for an elevator, for a conveyor, such as an escalator, for a moving walk, or for an inclined elevator.
There are known elevators with linear motors arranged to move an elevator car in the elevator shaft. in the known solutions, the stator of the linear motor comprises coils with magnetic cores.
One drawback in the known attempts is that the stator becomes very heavy and costly due to having lots of magnetic core material therein. Furthermore, the stator has a complex structure due to the magnetic cores in the coils. This is especially problematic in elevators having long elevator shafts, for example, in tall buildings. Furthermore, the magnetic cores cause transverse forces in the motor which must be compensated. Thus, there is still a need to develop linear motors used in elevators.
An objective of the present invention is to provide a linear motor and an elevator. Another objective of the present invention is that the linear motor and the elevator at least alleviate some of the drawbacks in the known elevators.
The objectives of the invention are reached by a linear motor and an elevator as defined by the respective independent claims.
According to a first aspect, a linear motor is provided. The linear motor comprises a stator and a mover adapted to move along the stator. One of the stator and the mover comprises a plurality of non-magnetic core coils, such as air core coils, arranged in at least one row of coils in a longitudinal direction of the one of the stator and the mover. Furthermore, the other of the stator and the mover comprises permanent magnets arranged in at least two adjacent rows of permanent magnets in a longitudinal direction of the other of the stator and the mover, wherein the adjacent rows of permanent magnets are separated by a gap dimensioned for receiving the at least one of row of coils.
It is to be understood that the gap must be dimensioned such that it enables movement of the rows of permanent magnets and the rows of coils relative to each other. Thus, in various embodiments, there is an air gap between said rows.
Optionally, at least one of the adjacent rows of permanent magnets may be arranged, such as at least partly or substantially completely, in a form of Halbach array including a strong side and a weak side, wherein the strong side is arranged to face the at least one row of coils.
A Halbach array refers herein to an arrangement of permanent magnets that augments the magnetic field on one side of the array, that is on the strong side, while cancelling the field to near zero, or at least generating a lower field with respect to the strong side, on the other side, that is on the weak side. The strong side and the weak side are, preferably, opposite sides of the array.
In some embodiments, the at least two of the adjacent rows of permanent magnets may be arranged in form of Halbach arrays including the strong sides and the weak sides, wherein the strong sides are arranged to face the at least one row of coils. Furthermore, magnetic poles of the adjacent rows of permanent magnets may be arranged to align with respect to each other.
In some embodiments, the linear motor may comprise at least two adjacent sets of one row of coils and two adjacent rows of permanent magnets. Thus, the linear motor may comprise, for example, two adjacent rows of coils which are respectively sandwiched between two rows of permanent magnets, of which one, two, or even all of them may be arranged partly or completely in form of Halbach arrays.
In various embodiments, the plurality of non-magnetic core coils may be arranged in at least two adjacent rows of coils in the longitudinal direction of the one of the stator and the mover, wherein the rows are arranged to be separated by a second gap. Furthermore, the permanent magnets may be arranged in at least three adjacent rows of permanent magnets in the longitudinal direction of the other of the stator and the mover, wherein the adjacent rows of permanent magnets are separated by gaps dimensioned for receiving the at least two adjacent rows of coils, respectively. Thus, two of the adjacent rows of permanent magnets are outermost rows and at least one of the adjacent rows of permanent magnets is a middle row. Further still, one or both of the outermost rows may be arranged in form of Halbach arrays including strong sides and weak sides, wherein each of the strong sides may be arranged to face one of the at least two rows of coils. Magnetic poles of the adjacent rows of permanent magnets may, preferably, be arranged to align with respect to each other.
In some embodiments, the permanent magnets of the at least one middle row may comprise two portions separated in the direction of motor normal N by a support portion of ferromagnetic material. The magnetic poles of the two portions are arranged to align. The two portions may thus substantially sandwich the support portion.
The second gap must also be dimensioned such that it enables movement of the rows of permanent magnets and the rows of coils relative to each other. Thus, in various embodiments, there is an air gap between said rows.
In addition, in the at least one middle row, the permanent magnets, such as typical permanent magnets which may not be in the form of a Halbach array, may be arranged by turns with reversed magnetic poles in the direction of motor normal, and to have magnetic poles of the permanent magnets aligned with the magnetic poles of the permanent magnets of the outermost rows.
In various embodiments, coil openings, or particularly surface normals thereof, of the plurality of non-magnetic core coils may be arranged in a direction of motor normal, or to face in said direction, for providing main flux in a transverse direction of the stator.
Alternatively or in addition, the permanent magnets in the adjacent rows may be arranged by turns with reversed magnetic poles in the direction of motor normal, and having magnetic poles of the adjacent rows of permanent magnets aligned with respect to each other.
In various embodiments, the non-magnetic core coils may have been manufactured by additive manufacturing.
In some embodiments, the non-magnetic core coils may be tilted with respect to a perpendicular direction relative to both the longitudinal direction and a motor normal, for example, the non-magnetic core coils being tilted with respect to a first direction.
In various embodiments, the stator may comprise, in the longitudinal direction of the stator, the plurality of air core coils arranged in two adjacent rows separated by a gap, and wherein the mover may comprise permanent magnets arranged in three adjacent rows separated by two gaps dimensioned to receive the air core coils.
According to a second aspect, an elevator is provided. The elevator may comprise an elevator shaft and an elevator car adapted to move in the elevator shaft, wherein the elevator comprises a linear motor according to the first aspect.
In various embodiments, the elevator shaft may be equipped with a charging station comprising at least one second coil and a power stage to modulate the at least one second coil. The at least one, or a plurality of, second coil(s) may be arranged to be located adjacent to at least one of the non-magnetic core coils, such as air core coils, to face the at least one of the non-magnetic core coils when the elevator car is present at the charging station. The non-magnetic core coils are optionally arranged to the mover. Furthermore, the power stage is configured to modulate the at least one second coil when the elevator car is present at the charging station for transferring electrical power wirelessly between, such as from the at least one second coil to the non-magnetic core coil.
Alternatively or in addition, the elevator shaft may be equipped with a direction changing position comprising at least one third coil arranged to align with the plurality of non-magnetic core coils of the one of the stator and the mover when the elevator car is present at the direction changing position, thereby enabling the wireless power transfer between the non-magnetic core coils and the at least one third coil. The elevator shaft may further comprise equipment including an actuator configured for changing movement direction of the elevator car. Thereby electrical power may be supplied therebetween, particularly from the non-magnetic core coils via the third coil to the actuator.
The present invention provides a linear motor and an elevator. The present invention provides advantages over known solutions in that the stator or the mover becomes lighter and less costly due to having coils with non-magnetic cores, such as air core coils. Furthermore, the utilization of non-magnetic cores decreases the amount of transverse forces in the motor.
Furthermore, in some preferable embodiments, by utilizing a Halbach array, a much higher propulsion force density per magnet material may be achieved than in the known solutions in which Halbach arrays are not used. By utilizing Halbach arrays, thinner magnets may be used to produce the same force compared to conventional permanent magnets.
Various other advantages will become clear to a skilled person based on the following detailed description.
The expression “a plurality of” may refer to any positive integer starting from two (2), that is, being at least two.
The terms “first”, “second” and “third” are herein used to distinguish one element from other element, and not to specially prioritize or order them, if not otherwise explicitly stated.
The exemplary embodiments of the present invention presented herein are not to be interpreted to pose limitations to the applicability of the appended claims. The verb “to comprise” is used herein as an open limitation that does not exclude the existence of also unrecited features. The features recited in depending claims are mutually freely combinable unless otherwise explicitly stated.
The novel features which are considered as characteristic of the present invention are set forth in particular in the appended claims. The present invention itself, however, both as to its construction and its method of operation, together with additional objectives and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
Some embodiments of the invention are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings.
The elevator 100 may comprise a plurality of landing floors 19, such as having landing floor doors, which the elevator car 5 or cars 5 may be arranged to serve.
However, even though in
In various embodiments, the linear motor 10 may comprise one stator 20 or a plurality of stators 20. Furthermore, there may be one mover 15 or, preferably, a plurality of movers 15 arranged to be coupled to the elevator car 10 for moving the elevator car 10 along the stator or stators 20. Details of the linear motor 10 according to some embodiments of the present invention will be described hereinbelow.
The elevator 100 may, in addition, comprise an elevator control unit 1000. The elevator control unit 1000 may, preferably, be at least communicatively and, optionally, electrically, coupled to various components and sub-systems of the elevator 100, as illustrated in
The processor of the elevator control unit 1000 may be configured to implement various tasks related to the operation of the elevator 100. The implementation of the method may be achieved by arranging the processor to execute at least some portion of computer program code stored in the memory causing the processor, and thus the elevator control unit 1000, to perform various tasks related to the operation of the elevator 100. The processor is thus arranged to access the memory and retrieve and store any information therefrom and thereto. For sake of clarity, the processor herein refers to any unit suitable for processing information and control the operation of the elevator control unit 1000, among other tasks. The operations may also be implemented with a microcontroller solution with embedded software. Similarly, the memory is not limited to a certain type of memory only, but any memory type suitable for storing the described pieces of information may be applied in the context of the present invention.
In
Alternatively, the stator 20 or stators 20 may comprise the non-magnetic core coils, such as air core coils. Furthermore, the mover 15 may comprise permanent magnets arranged thereto. In such cases, the non-magnetic core coils may be controlled by an electrical converter or converters arranged to the elevator shaft.
The mover 15 or movers 15 may be arranged to the back wall of the car 5, that is to provide a rucksack type elevator car, or, alternatively, the mover 15 or movers 15 may be arranged to side wall or walls of the elevator car 5.
Alternatively, the elevator 100 may comprise guide rail or rails (not shown) and elevator car 5 may be provided with guide shoes (not shown), such as sliding shoes or rotating guide rollers, arranged to control the lateral movement of the elevator car 5, that is movement in the first X and/or the second Y directions (the second direction Y being shown in
There may or may not be a counterweight coupled to the elevator car 5 being utilized in various embodiments of the present invention.
The coil openings of the plurality of non-magnetic core coils 25 may, preferably, be arranged in a direction of motor normal N for providing main flux in a transverse direction of the stator 20, in
The first direction X is preferably substantially perpendicular relative to both the longitudinal direction Z and the second direction Y.
Furthermore, in
The permanent magnets 28 in the adjacent rows 27 may, preferably, be arranged by turns with reversed magnetic poles in the direction of motor normal N, and having magnetic poles of the adjacent rows of permanent magnets 27 aligned with respect to each other. The magnetic poles being reversed in turns is illustrated in a non-limiting example in
The linear motor 10 may thus be operated by injecting alternating current to the plurality of non-magnetic core coils 25 which generate an electromagnetic coupling, or traveling magnetic field, with the permanent magnets 28, and therefore enables movement of the stator 20 and the mover 15 relative to each other as is known per se. Known control methods, such as vector or field-oriented control may be utilized.
Furthermore, in various embodiments, at least one, preferably at least two, of the rows of permanent magnets 27 may be arranged, at least partly or substantially completely, in a form of Halbach array including a strong side and a weak side, the strong side facing the at least one row of coils 24.
The coil openings of the plurality of non-magnetic core coils 25 may, preferably, be arranged in a direction of motor normal N for providing main flux in a transverse direction of the stator 20, in
Furthermore, in
In some embodiments, the permanent magnets 28 of the at least one middle row may comprise two portions separated in the direction of motor normal N by a support portion of ferromagnetic material. The magnetic poles of the two portions are arranged to align.
The permanent magnets 28 in the adjacent rows 27 may, preferably, be arranged by turns with reversed magnetic poles in the direction of motor normal N, and having magnetic poles of the adjacent rows of permanent magnets 27 aligned with respect to each other. The magnetic poles being reversed in turns is illustrated in a non-limiting example in
The linear motor 10 may thus be operated by injecting alternating current to the plurality of non-magnetic core coils 25 which generate an electromagnetic coupling, or traveling magnetic field, with the permanent magnets 28, and therefore enables movement of the stator 20 and the mover 15 relative to each other as is known per se. Known control methods, such as vector or field-oriented control may be utilized.
Furthermore, in various embodiments at least the outermost rows of permanent magnets 27 may be arranged in a form of Halbach array including a strong side and a weak side, the strong side facing one of the at least two rows of coils 24.
Regarding
The structure in accordance with any one of
Furthermore, the structure shown in
Still further, the structure shown in
In various embodiments, in the linear motor 10 with or without Halbach array(s) 40, the non-magnetic core coils 25 may be manufactured by additive manufacturing, such as by 3D printing. This provides advantages in that the additively manufactured coils enable manufacturing space efficient machinery, simpler structure, and it further facilitates heat optimization of the coils 25.
By 3D printing the conductive materials, such as copper, and the insulation material, such as between the turns of the coil(s), a solid structure is possible to be manufactured which can carry loads without additional strengthening structures. In the conventional coils, to achieve a tight radius in the inner curves, a small diameter wire needs to be used. This challenge is overcome by utilizing 3D printing. 3D printing enables the use of space more efficiently as the center hole and distance between coils can be minimized and the coil ends can be shortened. 3D printing can also enable the use of bigger cross-section area of conductive material, such as copper, and vary the cross-section so that loss distribution can be optimized.
Regarding
In
Furthermore, the other of the stator 20 and the mover 15 comprising the permanent magnets 28 arranged in at least two adjacent rows of permanent magnets 27 may further comprise, in the wireless charging arrangement 200, at least one second coil 26. In some embodiments, the at least one, or a plurality of, second coil(s) 26 may be similar, non-magnetic core coils, such as air core coils, as in the one of the stator 20 and the mover 15, that is second non-magnetic core coils.
The coil(s) 26 may preferably be arranged to align with the plurality of non-magnetic core coils 25 of the one of the stator 20 and the mover 15 at a charging station 201 or stations 201, thereby enabling the wireless power transfer between the non-magnetic core coils 25 and the second, optionally non-magnetic core, coil(s) 26. The wireless charging arrangement 200 provides the advantage that there is no need to provide separate charging coils to said one of the stator 20 and the mover 15 comprising the plurality of non-magnetic core coils 25 which saves space and is cost-efficient.
In an embodiment, the mover 15 is provided with the non-magnetic core coils 25 and the stator 20 is provided with permanent magnets. Charging station 201 comprises the second, optionally non-magnetic core, coil(s) 26 and a charger, which comprises a power stage 210 (e.g. solid state switches arranges in a H-bridge) coupled to the second coil(s) 26. The second coil(s) 26 may be located outside of the outermost rows of the permanent magnets, such that the outermost rows of the permanent magnets are disposed in a gap between the second coil(s) 26 and the non-magnetic core coils 25 of the mover 15 when the elevator car 5 has stopped to the charging station 201. In this position, the second coil(s) 26 and the non-magnetic core coils 25 are aligned such that an inductive coupling may be established between the non-magnetic core coils 25 and the second coil(s) 26. Consequently, electrical power may be supplied to the energy storage 14 of the elevator car 5 through antiparallel-connected diodes of the electrical converter unit 12 by modulating the second coil(s) 26 with the power stage 210 of the charger.
In various embodiments, the charging station 201 or stations 201 may be arranged to be located on or below the level of a landing floor 19 or floors 19.
In
Regarding the elevator shaft 30, it may be such as defining substantially closed volume in which the elevator car 5 is adapted and configured to be moved. The walls may be, for example, of concrete, metal or at least partly of glass, or any combination thereof. The elevator shaft 30 herein refers basically to any structure or pathway along which the elevator car 5 is configured to be moved.
As can be seen in
In similar manner as described in connection with
The equipment at the direction changing positions 300 may in some embodiments comprise, for example, an actuator 320 or actuators 320 configured to rotate stator 20 or stators 20 for one position to another in order to change the movement direction of the elevator car 5. According to one example, the elevator car 5 may be moved to a direction changing position 300 in vertical direction, then stopped at the position 300. Subsequently, the actuator 320 or actuators 320 may be arranged to rotate while substantially simultaneously rotating the mover(s) 15 of the elevator car 5. The actuator 320 or actuators 320 may be operated by providing electrical power between the non-magnetic core coils 25 of the linear motor 10 and the third, optionally non-magnetic core, coil(s) 310 at the direction changing position 300.
In an embodiment, the mover 15 is provided with non-magnetic core coils 25, and the stator 20 is provided with permanent magnets, and actuators 320 are provided with additional power transfers coils, such as third coils 310. The power transfer coils are located aligned with the non-magnetic core coils 25 when the elevator car 5 is in the direction changing position 300. In this position 300, inductive coupling is established between the non-magnetic core coils 25 and the additional power transfer coils, and electrical power may be supplied to the actuator 320 from the energy storage 14 of the elevator car 5, by modulating the non-magnetic core coils 25 with electrical converter unit 12.
In case of a non-limiting example, a linear motor 10 may comprise a stator 20 and a mover 15 adapted to move along the stator 20. One of the stator 20 and the mover 15, for example, the one being the mover 15, comprises a plurality of non-magnetic core coils 25, such as air core coils, arranged in at least one row of coils 24 in a longitudinal direction Z of the one of the stator 20 and the mover 15. The other of the stator 20 and the mover 15, for example the other being the stator 20, may comprise permanent magnets 28 arranged in at least two adjacent rows of permanent magnets 27 in a longitudinal direction Z of the other of the stator 20 and the mover 15, wherein the adjacent rows of permanent magnets 27 are separated by a gap dimensioned for receiving the at least one of row of coils 24. The non-magnetic core coils 25 have advantageously been manufactured by additive manufacturing, such as by 3D printing, which provides advantages in that the additively manufactured coils enable manufacturing space efficient machinery, simpler structure, and it further facilitates heat optimization of the coils 25.
In case of another non-limiting example, a linear motor 10 may comprise a stator 20 and a mover 15 adapted to move along the stator 20. One of the stator 20 and the mover 15, for example, the one being the mover 15, comprises a plurality of non-magnetic core coils 25, such as air core coils, arranged in at least one row of coils 24 in a longitudinal direction Z of the one of the stator 20 and the mover 15. The other of the stator 20 and the mover 15, for example the other being the stator 20, may comprise permanent magnets 28 arranged in at least two adjacent rows of permanent magnets 27 in a longitudinal direction Z of the other of the stator 20 and the mover 15, wherein the adjacent rows of permanent magnets 27 are separated by a gap dimensioned for receiving the at least one of row of coils 24. The non-magnetic core coils 25 may advantageously be tilted with respect to a perpendicular direction relative to both the longitudinal direction Z and the direction of motor normal N, in some cases the perpendicular direction being a first direction X. Thus, the benefit of tilting the coils 25 is that the guide rails and/or related elements may be manufactured which can withstand or generate less force for guiding the elevator car 5. This may entail utilizing cheaper and/or lighter materials, for instance. Also by reducing needed guide forces, the ride comfort can be increased.
In case of a further non-limiting example, an elevator 100 may comprise a linear motor 10 which comprises a stator 20 and a mover 15 adapted to move along the stator 20. One of the stator 20 and the mover 15, for example, the one being the mover 15, may comprise a plurality of non-magnetic core coils 25, such as air core coils, arranged in at least one row of coils 24 in a longitudinal direction Z of the one of the stator 20 and the mover 15. The other of the stator 20 and the mover 15, for example the other being the stator 20, may comprise permanent magnets 28 arranged in at least two adjacent rows of permanent magnets 27 in a longitudinal direction Z of the other of the stator 20 and the mover 15, wherein the adjacent rows of permanent magnets 27 are separated by a gap dimensioned for receiving the at least one of row of coils 24. Furthermore, the elevator 100 of the example may comprise at least one second coil 26, optionally a set of second non-magnetic core coils, arranged to the one of the stator 20 and the mover 15. For example, the at least one second coil 26 may be arranged to be located on or below the level of a landing floor 19 or floors 19. The at least one second coil 26 may be preferably arranged to align with the plurality of non-magnetic core coils 25 of the one of the stator 20 and the mover 15 at a charging station 201 or stations 201, thereby enabling the wireless power transfer between the non-magnetic core coils 25 and the at least one second coil 26. The second coils 26 may, however not necessarily, be identical to the non-magnetic core coils 25. The wireless charging arrangement 200 provides the advantage that there is no need to provide separate charging coils to said one of the stator 20 and the mover 15 comprising the plurality of non-magnetic core coils 25 which saves space and is cost-efficient.
In case of a still further non-limiting example, an elevator 100 may comprise a linear motor 10 which comprises a stator 20 and a mover 15 adapted to move along the stator 20. One of the stator 20 and the mover 15, for example, the one being the stator 20, comprises a plurality of non-magnetic core coils 25, such as air core coils, arranged in at least one row of coils 24 in a longitudinal direction Z of the one of the stator 20 and the mover 15. The other of the stator 20 and the mover 15, for example the other being the mover 15, may comprise permanent magnets 28 arranged in at least two adjacent rows of permanent magnets 27 in a longitudinal direction Z of the other of the stator 20 and the mover 15, wherein the adjacent rows of permanent magnets 27 are separated by a gap dimensioned for receiving the at least one of row of coils 24. Furthermore, the elevator 100 of the further example may comprise a set of third, optionally non-magnetic core, coils 310 arranged to said one of the stator 20 and the mover 15 arranged to be located at direction changing position 300 and arranged to align with the plurality of non-magnetic core coils 25 of the one of the stator 20 and the mover 15, thereby enabling the wireless power transfer between the non-magnetic core coils 25 and the third coils 310. Optionally, the third coils 310 are identical to the non-magnetic core coils 25. The elevator 100 may further comprise equipment including an actuator 320 at the direction changing position 300 configured for changing movement direction of the elevator car 5. The direction changing positions 300 provides the advantage that there is no need to provide separate wireless power transfer coils to said one of the stator 20 and the mover 15 comprising the plurality of non-magnetic core coils 25 which saves space and is cost-efficient.
Number | Date | Country | Kind |
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19197248.8 | Sep 2019 | EP | regional |