WO2020178472A1

WO2020178472A1 - Core unit for an electric linear motor, electric linear motor, manufacturing method and elevator

Info

Publication number: WO2020178472A1
Application number: PCT/FI2019/050174
Authority: WO
Inventors: Tero Hakala; Tero Purosto; Tuukka Korhonen; Marko MINKKINEN
Original assignee: Kone Corp
Current assignee: Kone Corp
Priority date: 2019-03-05
Filing date: 2019-03-05
Publication date: 2020-09-10
Anticipated expiration: 2021-09-05

Abstract

A core unit (33) for an electric linear motor (100), an electric linear motor (100), a manufacturing method, and an elevator (200) are presented. The core unit (30) comprises a first magnetic core (33), and a first finger joint portion (34) for providing magnetic path to a first further core unit.

Description

CORE UNIT FOR AN ELECTRIC LINEAR MOTOR, ELECTRIC LINEAR MOTOR, MANUFACTURING METHOD AND ELEVATOR

FIELD OF THE INVENTION

The present invention relates in general to electric linear motors. In particular, however, not exclusively, the present invention concerns electric linear motors of elevators.

BACKGROUND

Electric linear motors typically have relatively long stator beam which is fixed with respect to its surroundings. Furthermore, the motor comprises a mover, or a rotor, which is configured to be moved along the stator beam by injecting al ternating electrical current to the windings of the motor for establishing a moving magnetic field. The moving magnetic field then generates a force by which the mover can be moved with respect to and along the stator beam.

In known solutions, the cores of the mover and the stator of the stator beam are made of electrical steel, such as of magnetic material, to its final shape. How ever, in some known solutions, the mover and the stator are made by metal casting.

In the known solutions, however, the mover and the stator tend to be large and heavy, and require a lot of work in order to bring the motor to its place of instal lation and to assemble it for use. For example, in case of electric linear motors of elevators, welding the considerably large pieces of the motor within the ele vator shaft may be required. Furthermore, in the known solutions, the manufac turing tolerances of the motor parts are very strict and in case of any inaccura cies, the errors tend to accumulate in the motor and can thus affect to operation of the motor, such as of the magnetic circuit. Typically, different parts of the motor are arranged in contact with each other by bringing parallel contact sur faces of two consecutive parts together to form a contact area therebetween.

There is thus still a need to develop electric linear motors for at least alleviating some of the drawbacks of the known solutions. SUMMARY

An objective of the present invention is to provide a core unit for an electric linear motor, an electric linear motor, a manufacturing method and an elevator. An other objective of the present invention is that the core unit, the electric linear motor, the manufacturing method, and the elevator facilitate the assemble and manufacture of the motor.

The objectives of the invention are reached by a core unit, an electric linear motor, a manufacturing method, and an elevator as defined by the respective independent claims. According to a first aspect, a core unit for an electric linear motor is provided. The core unit comprises a first magnetic core, and a first finger joint portion for providing magnetic path to a first further core unit.

In various embodiments, the first finger joint portion may comprise joint elements protruding from the core unit. The joint elements may, preferably, define“the fingers” of the finger joint portion, that is, the joint elements may be adapted to be coupled, or to be arranged overlapped in a direction perpendicular with re spect to a longitudinal direction of the fingers, with joint elements of a further core unit or any element comprising such corresponding joint elements.

The core unit may comprise at least five, preferably at least ten, joint elements, preferably, evenly spaced with respect to each other. The at least five joint ele ments may, preferably, be arranged consecutively with respect to each other in the direction perpendicular with respect to the longitudinal direction of the joint elements and may have spaces between the joint elements adapted for receiv ing the joint elements of the further core unit or any element. In some embodi- ments, alternatively or in addition, sides of the joint elements may be parallel with respect to each other, wherein said sides extend away from the core unit. In various embodiments, alternatively or in addition, a length of the joint ele ments may be at least one millimeter, preferably two millimeters, or even five millimeters in the longitudinal direction of the joint elements. In various embodiments, the core unit may comprise a first end and an opposite second end, wherein the finger joint portion is arranged to the first end. The joint elements may, preferably, protrude or extend away from the core unit at the first end and substantially to the side of the core unit with respect to the longitudinal direction of the core unit, that is, the direction defined by the first and second ends.

In addition, the core unit may comprise at least one permanent magnet coupled to the first magnetic core. The first magnetic core may be adapted such that a first groove is arranged next to the at least one permanent magnet for providing cooling surface and/or directing a leakage flux. In some embodiments, the first groove may be arranged by providing a rounding shape to an edge of the first magnetic core to be arranged next to the permanent magnet. Alternatively or in addition, at least one side of the first magnetic core may be adapted such that a second groove is arranged to extend in a longitudinal direction of the core unit and next to the at least one permanent magnet for directing a leakage flux. In some embodiments, the second groove may be arranged by providing a round ing shape to an edge of the first magnetic core to be arranged next to the per manent magnet.

In various embodiments, the core unit may define an end of a magnetic tooth at the second end, wherein said end of the magnetic tooth is adapted for facing an air gap of the motor. The coil core may, preferably, be arranged such that an electromagnetic engagement or coupling may be established over the air gap between the mover and the stator of the electric linear motor.

In some embodiments, the core unit may comprise a second magnetic core and a second finger joint portion for providing magnetic path to a second further core unit. Furthermore, the first and the second magnetic cores may comprise the first and second finger joint portions, respectively, and the first and the second magnetic cores comprising the first and second finger joint portions may prefer ably be identical, respectively. The identical magnetic cores may, thus, be ar ranged next to each other, such as, optionally, having a permanent magnet or magnets therebetween, by having the first magnetic core in one position and the second magnetic core rotated 180 degrees with respect to the first magnetic core around an imaginary longitudinal axis of the second magnetic core.

In various embodiments, the at least one coil may be arranged around at least one of the following: the first magnetic core, the second magnetic core. Further more, the coil may also be arranged, or be wound, around the at least one per manent magnet. In various embodiments, the at least one permanent magnet may be arranged between the first and second magnetic cores.

In various embodiments, the core unit may comprise attachment means for at taching the core unit to a body part of the electric linear motor. The attachment means may comprise, for example, holes in the first and/or the second magnetic cores through which a bolt or a screw may be arranged so as to attach the core unit to the body part of the electric linear motor.

In some embodiments, the first magnetic core may comprise a second finger joint portion for providing magnetic coupling to a second further core unit. The core unit may, thus, be made substantially of one piece of material. Additionally, there may be the at least one permanent magnet arranged coupled to such core unit, for example, to a side of the core unit or inside to core unit.

In some embodiments, the core unit may comprise a liquid silicone rubber ele ment arranged for providing electrical insulation at least between the coil and the first magnetic material of the core unit. The liquid silicone rubber element may further be arranged at at least one side of the coil with respect to the longi tudinal direction of the core unit to provide electrical insulation.

In an embodiment, the second groove may be adapted for attaching the liquid silicone rubber element to the core unit while simultaneously providing directing of the leakage flux.

According to a second aspect, an electric linear motor is provided. The electric linear motor comprising a body part, and at least two core units, such as in ac cordance with the first aspect. The core units comprise first magnetic cores and finger joint portions. Furthermore, the core units are attached to the body part by attachment means and the finger joint portions of the at least two core units are coupled to each other for providing the magnetic path between said core units.

The electric linear motor may, in addition to the core unit or core units, comprise a plurality of different elements necessary or optional for obtaining the motor. The core unit, as referred to herein, may preferably refer to a part forming portion of a magnetic circuit of the motor. For example, the core unit or units may be shaped such as to direct or guide magnetic flux in a desired manner in the mag netic circuit and, thus, in the electric linear motor. In some embodiments, the body part may comprise aluminum and may be con figured for providing cooling for the core units. The cooling may occur through surfaces of the core unit and the body part being in contact with each other when attached to each other by the attachment means.

In various embodiments, the electric linear motor may comprise a mover which comprises the body part and the at least two core units. The electric linear motor may further comprise a stator beam along which the mover is configured to be moved. However, in some embodiments, the stator beam may comprise the body part and the core unit or units may be comprised in the stator of the stator beam.

According to a third aspect, a manufacturing method is provided. The method comprises

- obtaining a first magnetic core, and

- providing a first finger joint portion, wherein the first finger joint portion is cou pled to the first magnetic core.

In some embodiments, the obtaining may comprise additively manufacturing, such as utilizing a metal 3D printing technique, the first magnetic core and the first finger joint portion as a single-piece object.

In some other embodiments, the obtaining may comprise producing the first magnetic core by utilizing electrical steel sheets. The first finger joint portion may be provided integrally to the first magnetic portion, or it may be produced and attached separately to the first magnetic portion.

In various embodiments, the method may comprise obtaining a support structure for additive manufacturing of the first magnetic core, providing the first magnetic core on the support structure, providing the first finger joint portion to the first magnetic core, and disengaging the first magnetic core comprising the first fin ger joint portion from the support structure. In some embodiments, the disen gaging may comprise cracking the first magnetic core from the support structure for providing a rough surface at a first end of the first magnetic core, wherein the first finger joint portion may be arranged to the first end, for example, next to the rough surface. In some embodiments, alternatively or in addition, the disengaging comprises sawing the first magnetic core from the support structure.

According to a fourth aspect, an elevator is provided. The elevator comprises an electric linear motor. The electric linear motor comprises a body part and at least two core units according to the first aspect or any embodiment thereof. The core units are attached to the body part by attachment means, and wherein the finger joint portions of the at least two core units are coupled to each other for providing the magnetic path between said core units. The electric linear motor further com prises a mover arranged to be moved along a stator beam comprising a stator. The elevator further comprises at least one elevator car coupled to the mover of the motor for moving the at least one elevator car along the stator.

The present invention provides a core unit, an electric linear motor and a man ufacturing method. The present invention provides advantages over known so lutions such that by providing magnetic path between the core units by finger joints, the effective air gap is smaller because the surface area of the joint gets larger due to the finger joint. From the point of view of the magnetic circuit of the motor, the finger joint lowers the reluctance of the joint compared to known so lutions. The finger joint also facilitates the manufacturing of the core unit be cause the tolerances do not have to be so strict as there can remain gaps at the end of the joint elements of the finger joint because the magnetic flux can flow between the sides of the joint element, that is, in perpendicular direction with respect to the longitudinal direction of the joint element. Thus, inaccuracies in the manufacturing of the core units do not accumulate.

Various other advantages will become clear to a skilled person based on the following detailed description.

The expression "a number of” may herein refer to any positive integer starting from one (1 ).

The expression "a plurality of” may refer to any positive integer starting from two (2), respectively.

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 un-recited 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 inven tion 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.

BRIEF DESCRIPTION OF FIGURES

Some embodiments of the invention are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings.

Figure 1 illustrates schematically an electric linear motor according to an em bodiment of the present invention.

Figures 2A and 2B illustrate schematically a mover and a stator beam according to an embodiment of the present invention.

Figures 3A and 3B illustrate schematically a mover and a stator beam according to an embodiment of the present invention.

Figures 4A-4C illustrate schematically a core unit according to an embodiment of the present invention.

Figures 5A and 5B illustrate schematically a core unit according to an embodi ment of the present invention.

Figure 6 illustrates schematically an electric linear motor according to an em bodiment of the present invention.

Figures 7A and 7B illustrate schematically a finger joint between core units ac cording to an embodiment of the present invention.

Figures 8A and 8B illustrate schematically a liquid silicone rubber element ac cording to an embodiment of the present invention. Figures 9A and 9B illustrate schematically a liquid silicone rubber element ac cording to an embodiment of the present invention.

Figures 10A and 10B illustrate flow diagrams of methods according to embodi ments of the present invention.

Figure 1 1 illustrates core units according to an embodiment of the present in vention.

Figure 12 illustrates schematically an elevator according to an embodiment of the present invention.

DETAILED DESCRIPTION OF SOME EMBODIMENTS

Figure 1 illustrates schematically an electric linear motor 100 according to an embodiment of the present invention. The electric linear motor 100 may com prise a mover 20 or movers 20 configured to be moved with respect to a stator beam 10 or beams 10 comprising a stator or stators, such as illustrated with the two-headed arrow 23 in Fig. 1 . Preferably, an air gap 15 may be arranged be tween the mover 20 and the stator beam 10.

In various embodiments, the mover 20 or movers 20 may be configured to be moved along the stator beam 10 by an electromagnetic engagement or coupling between the mover 20 and the stator or stators of the stator beam 10. By the electromagnetic engagement a force may be generated which may be utilized for moving the mover 20 with respect to the stator beam 10. Establishing of the electromagnetic engagement may be based on, for example, injecting electrical current, such as alternating electrical current, into a winding or windings com prised in the mover 20 and/or stator or stators of the stator beam 10. The winding or windings may be, for example, three-phase windings. The winding or wind ings may comprise coils for producing a desired magnetic field when current is being injected into the coils.

In various embodiments, the air gap 15 may be regulated by controlling the cur rent being injected into the windings. Flowever, there may additionally be guiding elements, such as rollers or sliding surfaces for regulating the width of the air gap 15.

Figures 2A and 2B illustrate schematically a mover 20 and a stator beam 10 according to an embodiment of the present invention. In Fig. 2A, the mover 20 may comprise a plurality of magnetic teeth 22 arranged attached to a body part 21 of the mover 20. Furthermore, the mover 20 may, optionally, comprise coil 45 or coils 45 arranged around one, several or each magnetic teeth 22. Alterna tively or in addition, one, several or each of the magnetic teeth 22 may, option ally, comprise at least one permanent magnet 40. In various embodiments, the magnetic teeth 22 of the mover 20 or movers 20 may comprise magnetic core(s).

In some embodiments, the mover 20 may comprise a plurality of core units 30. The core units 30 may be arranged consecutively in contact or coupled with each other to form a part of the mover 20 which is utilized in establishing the electromagnetic engagement. The core units 30 may, preferably, form at least a part of one magnetic tooth 22.

In Fig. 2B, the stator beam 10 may comprise at least one stator 13 comprising a plurality of stator teeth 12. Furthermore, the stator beam 10 may comprise a body part 1 1 to which the stator 13 may be attached. The stator 13 may, prefer ably, be made of magnetic material, such as of ferromagnetic material. In some embodiments, the stator 13 may, alternatively or in addition, comprise a plurality of core units 30, such as described in connection with Fig. 2A with respect to the mover 20.

Figures 3A and 3B illustrate schematically a mover 20 and a stator beam 10 according to an embodiment of the present invention. In Fig. 3A, the mover 20 may comprise a plurality of magnetic teeth 22 arranged attached to a body part 21 of the mover 20. The magnetic teeth 22 of the mover 20 or movers 20 may, preferably, comprise magnetic core(s). In some embodiments, the mover 20 may, alternatively or in addition, comprise a plurality of core units, such as de scribed in connection with Fig. 2A.

In Fig. 3B, the stator beam 10 may comprise at least one stator 13 comprising a plurality of stator teeth 12. Furthermore, the stator beam 10 may comprise a body part 1 1 to which the stator 13 may be attached. The stator 13 may, prefer ably, be made of magnetic material, such as of ferromagnetic material. Further more, the stator 13 may, optionally, comprise coil 45 or coils 45 arranged around one, several or each magnetic teeth 12 of the stator 13. Alternatively or in addi tion, one, several or each of the magnetic teeth 12 may, optionally, comprise at least one permanent magnet 40. In various embodiments, the magnetic teeth 12 of the stator 13 or stators 13 may comprise magnetic core(s). In some embodiments, the stator 13 may, alternatively or in addition, comprise a plurality of core units 30, such as described in connection with Fig. 2A with respect to the mover 20.

Figures 4A-4C illustrate schematically a core unit 30 for an electric linear motor 100 according to an embodiment of the present invention. Fig. 4A illustrates the core unit 30 from a perspective view, Fig. 4B from a first side, and Fig. 4C from a second side being perpendicular with respect to the first side. The core unit 30 may comprise a first magnetic core 33, and a first finger joint portion 34 for providing magnetic path to a first further core unit (not shown). The first finger joint portion 34 may preferably comprise joint elements 36 protruding from the core unit 30. The joint elements 36 may, preferably, be evenly spaced with re spect to each other, however, not necessarily. Thus, there may be gaps 38 be tween the joint elements 36. According to one embodiment, there are at least five, preferably at least ten, joint elements 36 being arranged to the first finger joint portion 34. In various embodiment, a length of the joint elements 36 is at least one millimeter, preferably two millimeters, or even five millimeters.

In various embodiments, the joint elements 36 may extend directly away from the core unit 30, that is, perpendicularly with respect to a surface of the core unit 30. However, in some other embodiments, the joint elements 36 may extend in an angle other than 90 degrees with respect to said surface of the core unit 30, that is, for example, 80, 75, 70 or 45 degrees.

According to an embodiment, sides of the joint elements 36 may be parallel with respect to each other which said sides extend away from the core unit 30. This may mean that opposite sides of one joint element 36 are arranged to be or to extend in parallel with respect to each other.

In various embodiments, the core unit 30 may comprise a first end 31 and an opposite second end 32, wherein the finger joint portion 34 is arranged to the first end 31 .

In various embodiments, the core unit 30 may comprise at least one permanent magnet 40 coupled to, or at least be next to or even in contact with, the first magnetic core 33.

In some embodiments, the first magnetic core 33 may, optionally, be adapted such that a first groove 61 is arranged next to the at least one permanent magnet 40 for providing cooling surface and/or directing a leakage flux related to the magnetic operation of the motor.

In some embodiments, at least one side of the first magnetic core 33 may, alter natively or in addition, be adapted such that a second groove 62 is arranged to extend in a longitudinal direction 39 of the core unit 30 and next to the at least one permanent magnet 40 for directing the leakage flux.

In various embodiments, the core unit 30 may define an end of a magnetic tooth at the second end 32, wherein said end of the magnetic tooth is adapted for facing an air gap 15 of the motor 100. This means that the core unit 30 in ac cordance with Figs. 4A-4C, or with any embodiment of the core unit 30 as de scribed herein, may be utilized in an electric linear motor 100, such as shown in Figs. 1 -3B.

Figures 5A and 5B illustrate schematically a core unit 30 according to an em bodiment of the present invention. The core unit 30 may comprise a second magnetic core 53 and a second finger joint portion 54 for providing magnetic path to a second further core unit (not shown). In an embodiment, the first 33 and the second 53 magnetic cores comprise the first 34 and second 54 finger joint portions, respectively, and the first 33 and the second 53 magnetic cores comprising the first 34 and second finger 54 joint portions may be identical, re spectively. The identical magnetic cores may, thus, be arranged next to each other, such as, optionally, having a permanent magnet 40, 41 or magnets 40,

41 therebetween, by having the first magnetic core 33 in one position and the second magnetic core 53 rotated 180 degrees with respect to the first magnetic core 33 around an imaginary longitudinal axis 69 of the second magnetic core 53.

According to an embodiment, at least one coil 45 may be arranged around at least one of the following: the first magnetic core 33, the second magnetic core 53. Furthermore, the at least one permanent magnet 40, 41 may be arranged between the first 33 and second magnetic 53 cores, that is, the coil 45 may thus also be arranged around the permanent magnet 40, 41 .

In various embodiments, whether comprising only the first magnetic core 33 or the first and the second magnetic cores 33, 53, the core unit 30 may comprise attachment means 71 , 72 for attaching the core unit 30 to a body part 1 1 , 21 of the electric linear motor 100. In an embodiment, the attachment means 71 , 72 comprise at least one hole 71 being arranged to the core unit 30, such as to the first end 31 , and a bolt 72 or a screw 72 for arranging through the hole 71 , and for attaching the core unit 30 to the body part 1 1 , 21 .

According to an embodiment, the first magnetic core 33 may comprise, in addi tion to the first finger joint portion 34, a second finger joint portion 54 for providing magnetic coupling to a second further core unit (not shown). The core unit 33 may, thus, be made substantially of one piece of material. Additionally, there may be the at least one permanent magnet 40, 41 arranged coupled to such core unit 33, for example, to a side of the core unit 33 or inside to core unit 33. Thus, the core unit 33 may be such as it comprises the first 33 and the second 53 magnetic cores being integrated into one core unit 30.

In some embodiments, the first magnetic core 33 may comprises flanges 74 or extending elements 74 in order to keep the coil 45 and/or electrical insulation elements, such as a liquid silicon rubber element 90, in its position.

Figure 6 illustrates schematically an electric linear motor 100 according to an embodiment of the present invention. The electric linear motor 100 may com prise a body part 1 1 , 21 , and at least two core units 30. The core units 30 may comprise first magnetic cores 33 and finger joint portions 34. The core units 30 may be attached to the body part 1 1 , 21 by attachment means 71 , 72. The finger joint portions 34, 54 of the at least two core units 30 may be coupled to each other for providing the magnetic path between said core units 30. According to an embodiment, at least one coil 45 may be arranged around the core unit 30, that is, around both of the magnetic cores 33, 53. Furthermore, the at least one permanent magnet 40, 41 may be arranged between the first 33 and second magnetic 53 cores, that is, the coil 45 may thus also be arranged around the permanent magnet 40, 41 .

In Fig. 6, the core units 30 form a part of the mover 20 of the electric linear motor 100, that is, they may be attached to the body part 21 of the mover 20. Flowever, the core units 30 may, alternatively, form a part of the stator 10, that is, they may be attached to the body part 1 1 of the stator 13 and/or stator beam 10. The stator 13 may comprise a plurality of stator teeth 12. The electromagnetic engagement or coupling in the motor 100 may, preferably, be arranged between the teeth 22 of the mover 20 and the teeth 12 of the stator 13, having therebetween the air gap 15 at least during movement of said motor portions with respect to each other.

In various embodiments, the body part 1 1 , 21 may be adapted to conform with the shape of the core unit 30 or units 30 as illustrated in the example shown in Fig. 6. Alternatively or in addition, the body part 1 1 , 21 may comprise attachment holes or positions for the attachment means 71 , 72 so that the core units 30 may easily be arranged to the correct positions, such as, the finger joints 35 may be formed between consecutive core units 30. According to an embodiment, the body part 1 1 , 21 may comprise aluminum and may be configured for providing cooling for the core units 30, preferably, through the contact area between the body part 1 1 , 21 and the core unit 30 when attached to each other.

In some embodiments, the electric linear motor 100 may comprise a mover 20 comprising the body part 21 and the at least two core units 30 as illustrated in Fig. 6. The electric linear motor may further comprise a stator beam 10 along which the mover 20 may be configured to be moved as described hereinbefore with respect to Fig. 1 .

Figures 7A and 7B illustrate schematically a finger joint 35 between core units 30 according to an embodiment of the present invention. Fig. 7A illustrates the core units 30 being coupled by the finger joint portions 34, 54 thereof. In this case, the finger joint 35 includes the second finger joint portion 54 of the core unit 30 on the left and the first finger joint portion 34 of the core unit 30 on the right. As can be seen, the joint elements 36 overlap with respect to each forming the coupling and providing the magnetic path. There may be gaps 38 between the joint elements 36 of the finger joint portion 34, 54.

Fig. 7B illustrates the finger joint 35 in more detail. As can be seen, there may be provided low reluctance paths 80 for the magnetic flux in both the longitudinal direction of the joint elements 36 as well as in the perpendicular direction with respect to said longitudinal direction. Even if some of the joint elements 36, at their end, would not abut against the other core unit, the magnetic flux may still flow in said perpendicular direction across the finger joint 35. Therefore, the ef fective air gap in the joint becomes smaller as the magnetic flux may also flow in said perpendicular direction. The finger joint 35 increases the surface area between the core units 30 and, thus, lowers the reluctance of the magnetic cir cuit, that is including the finger joint 35, of the motor 100. Still further, the finger joint 35 facilitates the manufacturing the core units 30 because the tolerances are not as strict as for in known solutions for reasons given above, such as the joint elements 36 not needing to abut. The inaccuracies in manufacturing of the core units 30 do not, thus, accumulate because there can be some space be tween the end of the joint elements 36 and the consecutive core unit 30.

Figures 8A and 8B illustrate schematically a liquid silicone rubber element 90 according to an embodiment of the present invention. The liquid silicone rubber element 90 may, preferably, be arranged for providing electrical insulation at least between the coil 45 and the first magnetic material 33. Fig. 8A illustrates, from a perspective view, a part of an electrical machine, such as of an electric linear motor 100, comprising a coil 45 adapted for producing, when being in jected with an electrical current, a magnetic field. The electric linear motor 100 may be such a motor, however, not limited to such motors as described herein with respect to various embodiments of the present invention.

Typically, in known electrical machines, such as motors, in order to obtain a machine that is as light as possible without sacrificing the efficiency, material between the coil 45, such as of copper, and the magnetic core 33 should be minimized. Coil material generates resistive losses, which represent the biggest portion of the total losses in the magnetic circuit insulation papers are used between copper and magnetic core. In these known solutions, there will be empty space on coil ends. Once that empty space is taken in use, insulation will come more complex. Often used solution is plastic bobbin on the coil ends and on other complex areas. In that case, insulation tape and/or paper is primary insulation material and plastic bobbin is secondary insulation material.

The liquid silicon rubber element 90, however, combines a separate bobbin and an insulation material. Fig. 8B illustrates in more detail the liquid silicone rubber element 90 arranged around the first magnetic core 33. The coil 45 may then be arranged, such as wound, around the element 90, wherein the element 90 func tions as a primary insulation material. Liquid silicone rubber is a good material for electrical motors because it can stand high and low temperatures and its insulting properties are good. Typical, breakdown voltage of the iquid silicone rubber is of the order of 20-22 kilovolts per millimeter. Liquid silicone rubber is also flexible and slightly stretchy, which enables greater tolerances to be used and makes the installation easier. The liquid silicon rubber element 90 can advantageously be utilized even with magnetic cores having complex three-di mensional shapes.

According to various embodiments, the liquid silicone rubber element 90 may be utilized with core units 30 according to various embodiments of the present invention comprising a coil 45 or coils 45, that is, the core unit 30 may comprise a liquid silicone rubber element 90 arranged for providing electrical insulation at least between the coil and the first magnetic material. In addition, the liquid sili cone rubber element 90 may further be arranged at at least one side of the coil 45 with respect to the longitudinal direction 39 of the core unit 30 to provide electrical insulation.

In various embodiments, the second groove 62 may adapted for attaching the liquid silicone rubber element 90 to the core unit 30.

Figures 9A and 9B illustrate schematically a liquid silicone rubber element 90 according to an embodiment of the present invention. Fig. 9A illustrates a portion of an electric linear motor 100, such as a mover 20 and a stator beam 10 com prising a coil 45 or coils 45. In some embodiments, said portion is such an elec tric linear motor 100 as illustrated and described in connection with Figs. 1 -3B and 6, for instance. As can be seen, the liquid silicone rubber element 90 may be arranged over a plurality of consecutive magnetic teeth 12, 22 of said portion of the electric linear motor. Said portion of the electric linear motor in Figs. 9A and 9B may comprise at least one permanent magnet 40 arranged to the teeth 12, 22. Furthermore, said portion may comprise core units 30 in accordance with various embodiments of the present invention.

Step 1000 refers to a start-up phase of the method. Suitable equipment and components are obtained and systems assembled and configured for operation.

Step 1010 refers to obtaining a first magnetic core 33.

Step 1020 refers to providing a first finger joint portion 34, wherein the first finger joint portion 34 is coupled to the first magnetic core 33.

In various embodiments, the obtaining of the first magnetic core 33 may be per formed by manufacturing, such as machining, the core 33 from a solid piece of material or of a stack of electrical steel sheets. The finger joint portion 34 may be manufactured separately and then attached to the first magnetic core 33 or, alternatively, manufactured as a single-piece object.

According to an embodiment, the obtaining may comprise additively manufac turing, such as utilizing a metal 3D printing technique, for example, selective laser melting, the first magnetic core 33 and the first finger joint portion 34 as a single-piece object, such as, as a core unit 30. The material for 3D printing may be, for example, an alloy including iron and silicon, that is, ferrosilicon, or an alloy including iron and cobalt, that is, ferrocobalt.

According to some embodiments, the method may comprise obtaining 1015 a support structure for additive manufacturing of the first magnetic core 33, that is, prior to obtaining the first magnetic core 33. In addition, the method may com prise providing 1018 the first magnetic core 33 on the support structure. Addi tionally, the method may comprise providing 1020 the first finger joint portion 34 to the first magnetic core 33, and, at least after providing the first magnetic core 33 to the support structure, disengaging 1025 the first magnetic core 33 com prising the first finger joint portion 34 from the support structure.

In some embodiments, the disengaging may comprise cracking the first mag netic core 33 from the support structure for providing a rough surface 73 at a first end 31 of the first magnetic core 33, wherein the first finger joint portion 34 is arranged to the first end 31 . In an embodiment, the support structure may be a honeycomb-type of a support structure which facilitates the cracking by mak ing it easier and more accurate.

3D printing may be utilized to provide shape(s) to the first magnetic core 33 to conform with the shape of, for example, a body part 1 1 , 21 of the motor 100 in which the first magnetic core 33 is to be used.

In some embodiments, the disengaging comprises sawing the first magnetic core 33 from the support structure.

Method execution is stopped at step 1099.

Figure 1 1 illustrates actual core units 30 according to an embodiment of the present invention. In Fig. 1 1 , there are two core units 30 comprising magnetic cores 33, 53 and finger joint portions 34, 54. Furthermore, the core unit 30 are manufactured by utilizing additive manufacturing method and further being cracked from the support structure in accordance with some embodiments of the present invention.

Figure 12 illustrates schematically an elevator 200 according to an embodiment of the present invention. The elevator 200 may comprise an electric linear motor 100 comprising a body part 1 1 , 21 , and at least two core units 30 according to an embodiment of the present invention. The core units 30 may be attached to the body part 1 1 , 21 by attachment means 71 , 72, such as screws or bolts. The finger joint portions 34, 54 of the at least two core units 30 may be coupled to each other to form a finger joint 35 for providing the magnetic path between said core units 30.

The electric linear motor 100 may further comprise a mover 20 arranged to be moved, such as driven by a frequency converter or an inverter, along a stator beam 10 comprising a stator 13. The elevator 200 may further comprise at least one elevator car 210 coupled to the mover 20 of the motor 100 for moving the at least one elevator car 210 along the stator beam 10.

The electric linear motor 100 may further comprise a mover 20 or movers 20 arranged or coupled to the elevator car 210 or cars 210. The mover 20 or movers 20 may be arranged to be in electromagnetic engagement with the stator 13 or stators 13 comprised in the stator beam 10 along which the mover 20 is arranged to be moved, thus enabling the movement of the elevator car 210 with which the mover 20 has been mechanically coupled with.

There may be two or more elevator cars 210 arranged to be moved in the ele vator shaft 220 by an electric linear motor 100, the elevator cars 210 being cou pled to respective mover 20 or movers 20. The electric linear motor 100 may comprise a stator 13 or stators 13 comprised in a stator beam 10 or beams 10, in this case two. A stator beam 10 may be arranged vertically or horizontally, that is, in Fig. 12, the elevator 100 comprises vertical stator beams 10 and hori zontal stator beams 10. Flowever, the stator beam 10 or beams 10 may also be arranged to any direction(s) in which the elevator car 210 is desired to be moved.

The elevator shaft 220 may refer herein to the elevator car pathway which, as described above, may include vertical parts, horizontal parts, and/or parts hav ing a third direction different with respect to vertical and horizontal directions. For example, the part of the elevator shaft 220 depicted in Fig. 12 may essentially comprise two vertical parts and one horizontal part. It should be noted, however, that the elevator shaft 10 may in some cases comprise only one wall or a structure arranged to accommodate the necessary equipment such as the stator beam 10. Thus, the elevator shaft 220 or the elevator car pathway 220 does not necessarily have to define a substantially closed volume, that is, sur rounded by wall elements or glass or any other structures as long as there is at least a support structure to support the stator beam(s) 10.

The specific examples provided in the description given above should not be construed as limiting the applicability and/or the interpretation of the appended claims. Lists and groups of examples provided in the description given above are not exhaustive unless otherwise explicitly stated.

Claims

1. A core unit (30) for an electric linear motor (100), the core unit (30) com prising

- a first magnetic core (33), and - a first finger joint portion (34) for providing magnetic path to a first further core unit.

2. The core unit (30) according to claim 1 , wherein the first finger joint portion (33) comprises joint elements protruding from the core unit (30).

3. The core unit (30) according to claim 2, comprising at least five joint ele- ments (36), preferably, evenly spaced with respect to each other.

4. The core unit (30) according to claim 2 or 3, wherein a length of the joint elements (36) is at least one millimeter, preferably two millimeters, or even five millimeters.

5. The core unit (30) according to any one of claims 2-4, wherein sides of the joint elements (36) are parallel with respect to each other, wherein said sides extend away from the core unit.

6. The core unit (30) according to any one of the preceding claims, wherein the core unit (30) comprises a first end (31 ) and an opposite second end (32), wherein the finger joint portion (34) is arranged to the first end (31 ).

7. The core unit (30) according to any one of claims 1 -6, comprising at least one permanent magnet (40, 41 ) coupled to the first magnetic core (33).

8. The core unit (30) according to claim 7, wherein the first magnetic core (33) is adapted such that a first groove (61 ) is arranged next to the at least one per manent magnet (40, 41 ) for providing cooling surface and/or directing a leakage flux.

9. The core unit (30) according to claim 7 or 8, wherein at least one side of the first magnetic core (33) is adapted such that a second groove (62) is ar ranged to extend in a longitudinal direction of the core unit (30) and next to the at least one permanent magnet (40, 41 ) for directing a leakage flux.

10. The core unit (30) according to claim 9, defining an end of a magnetic tooth (12, 22) at the second end (32), wherein said end of the magnetic tooth (12, 22) is adapted for facing an air gap (15) of the motor (100).

1 1 . The core unit (30) according to any one of the preceding claims, comprising a second magnetic core (53) and a second finger joint portion (54) for providing magnetic path to a second further core unit.

12. The core unit (30) according to claim 1 1 , wherein the first (33) and the second (53) magnetic cores comprise the first (34) and second (54) finger joint portions, respectively, and the first (33) and the second (53) magnetic cores comprising the first (34) and second finger (54) joint portions are identical, re spectively.

13. The core unit (30) according to unit according to any one of the preceding claims, wherein at least one coil (45) is arranged around at least one of the following: the first magnetic core (33), the second magnetic core (53).

14. The core unit (30) according to claims 7 and 13, wherein the at least one permanent magnet (40, 41 ) is arranged between the first (33) and second (53) magnetic cores.

15. The core unit (30) according to any one of the preceding claims, comprising attachment means (71 , 72) for attaching the core unit (30) to a body part (1 1 , 21 ) of the electric linear motor (100).

16. The core unit (30) according to any one of claims 1 -10, wherein the first magnetic core (33) comprises a second finger joint portion (54) for providing magnetic coupling to a second further core unit.

17. The core unit (30) according to any one of the preceding claims, comprising a liquid silicone rubber element arranged for providing electrical insulation at least between the coil and the first magnetic material.

18. The core unit (30) according to claim 17, wherein the liquid silicone rubber element is further arranged at at least one side of the coil with respect to the longitudinal direction of the core unit to provide electrical insulation.

19. The core unit (30) according to claims 9, and 17 or 18, wherein the second groove is adapted for attaching the liquid silicone rubber element to the core unit.

20. An electric linear motor (100) comprising

- a body part (1 1 , 21 ), and

- at least two core units (30), wherein the core units (30) comprise first magnetic cores (33) and finger joint portions (34), wherein the core units (30) are attached to the body part (1 1 , 21 ) by attachment means (71 , 72), and wherein the finger joint portions (34) of the at least two core units (30) are coupled to each other for providing the magnetic path between said core units (30).

21 . The electric linear motor (100) according to claim 20, wherein the body part (1 1 , 21 ) comprises aluminum and is configured for providing cooling for the core units (30).

22. The electric linear motor (100) according to claim 20 or 21 , comprising a mover (20) comprising the body part (21 ) and the at least two core units (30), and wherein the electric linear motor (100) further comprises a stator beam (10) along which the mover (20) is configured to be moved.

23. A manufacturing method comprising

- obtaining a first magnetic core (33), and

- providing a first finger joint portion (34), wherein the first finger joint portion (34) is coupled to the first magnetic core (33).

24. The method according to claim 23, wherein the obtaining comprises addi- tively manufacturing, such as utilizing a metal 3D printing technique, the first magnetic core (33) and the first finger joint portion (34) as a single-piece object.

25. The method according to claim 23 or 24, comprising

- obtaining a support structure for additive manufacturing of the first magnetic core (33),

- providing, such as printing, the first magnetic core (33) on the support structure, - providing the first finger joint portion (34) to the first magnetic core (33), and

- disengaging the first magnetic core (33) comprising the first finger joint portion (34) from the support structure.

26. The method according to 25, wherein the disengaging comprises cracking the first magnetic core (33) from the support structure for providing a rough sur face at a first end (31 ) of the first magnetic core (33), wherein the first finger joint portion (34) is arranged to the first end (31 ).

27. The method according to 25, wherein the disengaging comprises sawing the first magnetic core (33) from the support structure.

28. An elevator (200) comprising an electric linear motor (100) comprising

- a body part (1 1 , 21 );

- at least two core units (30) according to any one of claims 1 -19, wherein the core units (30) are attached to the body part (11 , 21 ) by attachment means (71 , 72), and wherein the finger joint portions (34) of the at least two core units (30) are coupled to each other for providing the magnetic path between said core units (30); and

- a mover (20) arranged to be moved along a stator beam (10) comprising a stator (13); wherein the elevator (200) comprises at least one elevator car (210) coupled to the mover (20) of the motor (100) for moving the at least one elevator car (210) along the stator (10).