WO2019150718A1

WO2019150718A1 - Linear motor and method for manufacturing linear motor

Info

Publication number: WO2019150718A1
Application number: PCT/JP2018/042986
Authority: WO
Inventors: 康太郎和田; 達矢吉田
Original assignee: 住友重機械工業株式会社
Priority date: 2018-01-31
Filing date: 2018-11-21
Publication date: 2019-08-08
Also published as: TW201935819A; TWI713283B; JPWO2019150718A1

Abstract

A linear motor 100 is provided with: a movable element 50 that includes a field magnet 52; and a stator 10 that includes a plurality of coil modules 20 connected in the movable direction of the movable element 50. Each of the coil modules 20 includes a plurality of coils 26 arrayed in the movable direction.

Description

Linear motor and linear motor manufacturing method

The present invention relates to a linear motor and a method for manufacturing the linear motor.

A linear motor is used to convert electrical energy into linear motion. One type of linear motor is a moving magnet type linear motor in which a magnet travels along a coil. For example, Patent Document 1 describes a moving magnet type linear slider having an armature coil as a stator and a field magnet as a mover.

International Publication No. 2005/122369

The present inventor has obtained the following recognition regarding a moving magnet type linear motor (hereinafter simply referred to as a linear motor).
In many cases, the linear motor has different movable strokes of the mover depending on the application. Therefore, it is necessary for the linear motor to prepare armature coils having different lengths according to a desired movable stroke. That is, in order to cope with various applications, it is necessary to manufacture armature coils having different lengths for each application.

In some cases, an armature coil is manufactured by resin molding a plurality of coils arranged in a movable direction. This is uneconomical because it is necessary to prepare molds having different lengths for each application. Further, when the armature coil is particularly long, there is a problem that it is difficult to manufacture with a normal mold or resin molding equipment. From these, the present inventors have recognized that there is room for improvement in the linear motor from the viewpoint of facilitating the manufacture of the armature coil.
Such a problem may occur not only in an armature coil manufactured by resin molding but also in an armature coil manufactured by another method.

The present invention has been made in view of such problems, and an object thereof is to provide a linear motor that facilitates the manufacture of armature coils.

In order to solve the above-described problems, a linear motor according to an aspect of the present invention includes a mover including a field magnet and a stator including a plurality of coil modules connected in the moving direction of the mover. The coil module includes a plurality of coils arranged in a movable direction.

Another aspect of the present invention is a method of manufacturing a linear motor. This method is a method of manufacturing the above-described linear motor, in which a plurality of coils are accommodated in the case 22, a resin is poured into the case accommodating the plurality of coils, a coil module is formed, and the plurality of coils It includes arranging the modules in the movable direction and fixing them to the beam member, and electrically connecting the wiring member 34 to the coil 26.

According to the present invention, it is possible to provide a linear motor that facilitates the manufacture of armature coils.

It is a top view which shows the linear motor which concerns on embodiment of this invention. FIG. 2 is a sectional view taken along line AA in FIG. 1. It is a top view which shows schematically the stator of the linear motor of FIG. FIG. 2 is an explanatory diagram schematically illustrating wiring of the stator of FIG. 1. It is process drawing explaining the manufacturing process of the stator of the linear motor of FIG. It is sectional drawing of the linear motor which concerns on a 1st modification. It is sectional drawing of the linear motor which concerns on a 2nd modification. It is sectional drawing of the linear motor which concerns on a 3rd modification.

Hereinafter, the present invention will be described based on preferred embodiments with reference to the drawings. In the embodiment and the modification, the same or equivalent components and members are denoted by the same reference numerals, and repeated description is appropriately omitted. In addition, the dimensions of the members in each drawing are appropriately enlarged or reduced for easy understanding. Also, in the drawings, some of the members that are not important for describing the embodiment are omitted.

In the following description, “parallel” and “vertical” include not only perfect parallel and vertical, but also include cases in which they deviate from parallel and vertical within an error range. Further, “substantially” means that they are the same in an approximate range.
In addition, terms including ordinal numbers such as first and second are used to describe various components, but this term is used only for the purpose of distinguishing one component from other components. However, the constituent elements are not limited.
In addition, the linear motor includes one in which the mover moves on a curved track such as an arc, and is not limited to one in which the mover moves on a linear track.

[Embodiment]
A linear motor 100 according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing a linear motor 100 according to an embodiment. FIG. 2 is a side sectional view of the linear motor 100 taken along the line AA.

Hereinafter, description will be made mainly based on the XYZ rectangular coordinate system. The X-axis direction corresponds to the left-right direction in FIG. 1 and corresponds to the direction perpendicular to the page in FIG. The Y-axis direction corresponds to the vertical direction of the drawing in FIGS. The Z-axis direction corresponds to the direction perpendicular to the paper surface in FIG. 1, and corresponds to the left-right direction on the paper surface in FIG. The Y-axis direction and the Z-axis direction are each orthogonal to the X-axis direction. The positive direction of each of the X axis, Y axis, and Z axis is defined in the direction of the arrow in each figure, and the negative direction is defined in the direction opposite to the arrow. Further, the positive direction side of the X axis may be referred to as “right side”, and the negative direction side of the X axis may be referred to as “left side”. Also, the positive direction side of the Y axis may be referred to as “front side”, the negative direction side of the Y axis as “rear side”, the positive direction side of the Z axis as “upper side”, and the negative direction side of the Z axis as “lower side”. is there. Such notation of the direction does not limit the use posture of the linear motor 100, and the linear motor 100 can be used in any posture depending on the application.

(Linear motor)
The linear motor 100 includes a stator 10 and a mover 50. The mover 50 forms a magnetic circuit in the magnetic gap 60. The linear motor 100 functions as an energy conversion mechanism that generates thrust in the movable direction in the stator 10 in the magnetic gap 60. In the embodiment, the movable direction is arranged to coincide with the X-axis direction.

(Movable element)
First, the mover will be described. The mover 50 includes a pair of field magnets 52, a pair of yokes 54, and a spacer 56. The field magnet 52 and the pair of yokes 54 constitute a magnetic circuit that forms a field magnetic field in the magnetic gap 60. The magnetic gap 60 is a gap between the pair of field magnets 52.

The pair of yokes 54 are plate-like members that extend in the X-axis direction and the Y-axis direction and are thin in the Z-axis direction. In plan view, the pair of yokes 54 has a substantially rectangular outline having two sides parallel to the X-axis direction and two sides parallel to the Y-axis direction. The pair of yokes 54 is formed of various known soft magnetic materials. The pair of yokes 54 are arranged in parallel with each other apart in the Z-axis direction.

The spacer 56 is disposed in an upper region between the pair of yokes 54 and holds the distance between the pair of yokes 54 in the Z-axis direction. The pair of yokes 54 are fixed to the spacer 56 by a fixing tool 58 (for example, bolts) through a plurality of through holes provided in the vicinity of the upper end thereof.

The field magnet 52 functions as a magnetic flux supply source that forms a field magnetic field in the magnetic gap 60. The field magnet 52 may include one or more magnets. The field magnet 52 may be configured by arranging a plurality of magnets in a Halbach array. A plurality of magnetic poles are provided on the surface of the field magnet 52 at predetermined intervals in the X-axis direction. In the embodiment, six magnetic poles are provided. The field magnet 52 may be formed of various known magnet materials. In this example, the field magnet 52 is formed of a rare earth magnet material such as NdFeB. The field magnet 52 may be fixed to the yoke 54 by a known means such as adhesion.

(stator)
The stator 10 includes a plurality of coil modules 20 extending in the X-axis direction, a beam member 30, a second beam member 31, and a wiring member 34. The plurality of coil modules 20 are arranged in the X-axis direction, which is the movable direction. For example, the coil module 20 is a substantially plate-like member that has a substantially rectangular shape in plan view and is thin in the Z-axis direction. In this example, the coil module 20 is arranged so that the long side is along the X-axis direction and the short side is along the Y-axis direction in plan view.

The coil module 20 includes a coil assembly 24 and a case 22. The coil assembly 24 includes a plurality of coils 26 arranged in the X-axis direction and a connector 36. The plurality of coils 26 are integrated by being wrapped in resin 24m. When the case 22 is provided, as an example, the coil assembly 24 is formed by injecting a resin 24m into the case 22 in which a plurality of coils 26 are arranged. It is not essential to provide the case 22. When the case 22 is not provided, as an example, the coil assembly 24 is formed by insert molding in which a resin 24m is injected into a mold in which a plurality of coils 26 are arranged. These manufacturing methods are merely examples, and the coil assembly 24 may be formed by various other manufacturing methods.

The coil 26 has two sides parallel to the X-axis direction and two sides parallel to the Y-axis direction, and has a substantially rectangular outline with four corners rounded into an R shape. The coil 26 may have a contour formed by a curve such as an ellipse as a whole having no side, or may have contours of various other shapes. The coil 26 may be an iron core coil, but in this example, is an air core coil. The coil 26 is composed of a wire wound around the Z axis. When a drive current is supplied to the coil 26, the coil 26 functions as an armature coil that generates a magnetic flux in the Z-axis direction and causes the field magnet 52 to generate a thrust in the X-axis direction.

The connector 36 includes electrodes electrically connected to the lead wires of the plurality of coils 26. The connector 36 may be connected to lead wires (lead wires) of the plurality of coils 26 before the insert molding, and may be integrated with the plurality of coils 26 by insert molding. Alternatively, the connector 36 may be connected to the lead wires of the plurality of coils 26 after the insert molding. In this case, the lead wire may be directly taken out from the coil 26 and the connector 36 may be connected to the tip of the lead wire.

The case 22 is provided so as to cover the periphery of the coil assembly 24. The case 22 suppresses outflow of gas generated from the coil 26 and the resin 24m surrounding the coil 26 to the outside. The case 22 is a rectangular parallelepiped box composed of a box-shaped case main body 22b having five open upper surfaces and a lid 22c covering the upper surface of the case main body 22b. The lid 22c may be fixed to the upper surface of the case body 22b that houses the coil assembly 24, for example, by welding. The case 22 may be formed of a metal material such as nonmagnetic stainless steel or a nonmetal material such as ceramic.

Next, the wiring member 34 will be described. FIG. 3 is a plan view schematically showing the stator 10. FIG. 4 is an explanatory diagram for explaining the wiring of the stator 10. The wiring member 34 functions as a path for supplying current from the drive circuit 40 to the coil 26. The current from the drive circuit 40 flows to the coil 26 through the wiring member 34, the connector 36, and the lead wire 26 b connected to the electrode of the connector 36. The wiring member 34 is, for example, a wire module or a printed wiring board. In the embodiment, the wiring member 34 is a printed wiring board on which another connector (not shown) for connecting to the connector 36 is mounted. In the embodiment, the wiring member 34 is accommodated in a passage recess 30b of the beam member 30 described later.

The full excitation method and the partial excitation method can be considered as methods for supplying drive current to the plurality of coil modules 20. The full excitation method is a method for supplying a drive current to all the coils constituting one phase. The full excitation system has a feature that wiring is relatively easy. The partial excitation method is a method for selectively supplying a drive current to the coil 26 in the vicinity of the mover 50. The partial excitation method has a feature that wasteful power is small. In the embodiment, a partial excitation method is adopted. As shown in FIG. 4, each coil module 20 is connected to the drive circuit 40 independently of the other modules.

The beam member 30 and the second beam member 31 function as a beam for connecting the plurality of coil modules 20 and for imparting a desired rigidity to the stator 10. In this example, the beam member 30 and the second beam member 31 are bar-shaped members having a rectangular cross section extending in the X-axis direction. As shown in FIG. 2, the beam member 30 is provided with a passage recess 30b extending in the X-axis direction. The passage recess 30b is a recess that is open on the coil module 20 side and recedes upward. The passage recess 30 b accommodates the connector 36 and the wiring member 34. The beam member 30 is disposed on the upper surface of the coil module 20, and the second beam member 31 is disposed on the lower surface of the coil module 20. The plurality of coil modules 20 are fixed to the beam member 30 and the second beam member 31 by fixing members 32 such as bolts. The beam member 30 may be formed as a seamless integrated member, or a plurality of members may be integrated. The same applies to the second beam member 31.

Next, the number of coils 26 (hereinafter simply referred to as the number of coils) constituting the coil module 20 will be described. In the case of three-phase driving, the number of coils is desirably an integer multiple of three. Note that the number of coils is not necessarily an integer multiple of 3, and the number of coils may be set arbitrarily. That is, the coil module 20 may be configured with a number of coils 26 other than an integral multiple of 3 as necessary. In particular, in the case of partial excitation using a moving magnet type, it is only necessary to excite the integer number of coils 26, so that modules other than the integer number of 3 may be modularized.

In the case of a motor with a long movable stroke, if the number of coils is three, the number of coil modules increases and the manufacturing cost increases, so six coils are desirable. In the case of a motor having a short movable stroke, if the number of coils is 6 or more, the stator may become unnecessarily long. Therefore, the number of coils is preferably 3.

If one coil module 20 becomes too long, the possibility that the coil module 20 warps and contacts the mover 50 increases. From this viewpoint, the number of coils is desirably six or less.

Next, an example of the manufacturing process of the linear motor 100 will be described. FIG. 5 is a process diagram illustrating the manufacturing process S80 of the linear motor 100. FIG. In particular, the manufacturing process S80 includes processes S82 to S92 for manufacturing the stator 10.

In step S82, the air core coil 26 is manufactured by winding a wire whose surface is insulated.

In step S84, the plurality of coils 26 are accommodated in the case main body 22b. A connector 36 is attached to the plurality of coils 26 before or after being accommodated in the case body 22b. In the embodiment, the connector 36 is attached to the coil 26 before being accommodated in the case main body 22b. The connector 36 is integrated with the coil 26 by the resin 24m poured in the next process.

In step S86, the resin 24m is poured into the case main body 22b in which the plurality of coils 26 are accommodated to integrate the plurality of coils 26 to form the coil assembly 24.
In step S88, the lid 22c is placed over the case body 22b that houses the coil 26 into which the resin 24m has been poured.

In step S90, the lid 22c is fixed to the case body 22b by, for example, welding. The lid 22c is provided with an opening 22e, and the connector 36 is exposed from the opening 22e with the lid 22c fixed.

In step S92, the plurality of coil modules 20 are arranged in the X-axis direction, the connector 36 is electrically connected to the wiring portion of the wiring member 34, and the beam member 30 and the second beam member 31 are fixed. In this way, the stator 10 is manufactured.

The linear motor 100 is manufactured by inserting the stator 10 manufactured in this way into the magnetic gap 60 of the mover 50 manufactured separately. This manufacturing process S80 is only an example, and another process may be added, a part of the process may be changed or deleted, or the order of the processes may be changed.

As shown in FIG. 1, the wall surface of the case 22 is doubled between the coil module 20 and the adjacent coil module 20. The outflow of gas from the resin 24m can be reduced as compared with the case without such a wall surface.

The operation of the linear motor 100 configured as described above will be described. When an alternating drive current is supplied from the drive circuit 40 to the coil module 20, the coil module 20 generates a moving magnetic field in the movable direction and applies a thrust in the movable direction to the field magnet 52 of the mover 50. The linear motor 100 drives the drive target connected to the mover 50 by this thrust.

The outline of one embodiment of the present invention is as follows. The linear motor 100 according to an aspect of the present invention includes a mover 50 including a field magnet 52 and a stator 10 including a plurality of coil modules 20 connected in a moving direction of the mover 50. The coil module 20 includes a plurality of coils 26 arranged in a movable direction.

According to this aspect, when the design is performed by changing the movable stroke of the linear motor 100, it is possible to cope with the change by changing the number of coil modules 20 to be connected, so that the design can be standardized and the design man-hours can be reduced. When manufacturing by changing the movable stroke of the linear motor 100, the number of coil modules 20 to be connected can be changed, so that molds, jigs and manufacturing equipment can be shared. Since the coil module 20 can be made into a length suitable for manufacturing, when the long linear motor 100 is manufactured, the jigs and the coil module 20 can be easily handled. Further, the operation of connecting the coil modules 20 can be performed at the site where the linear motor 100 is installed.

The number of coils of the plurality of coils 26 may be an integer multiple of three. In this case, compared with the case where the number of coils is other than an integral multiple of 3, the possibility that the stator becomes unnecessarily long due to unnecessary coils can be reduced.

The number of coils of the plurality of coils 26 may be 6 or less. In this case, since the coil module 20 can be shortened compared with the case where the number of coils is seven or more, the possibility that the coil module 20 warps and contacts the mover 50 can be reduced.

The coil module 20 includes a connector 36 including electrodes that are electrically connected to the plurality of coils 26. In this case, when connecting the coil module 20, the connector 36 can be easily connected to the wiring portion of the wiring member 34. If the connector is detachable, the existing linear motor can be easily disassembled and reused. When changing the stroke of the existing linear motor, the additional coil module 20 can be easily connected. Compared to the case where the existing linear motor is discarded and a new linear motor is installed, the wasteful resources can be greatly reduced.

Another aspect of the present invention is a method of manufacturing a linear motor. This method includes housing a plurality of coils 26 in a case 22, forming a coil module 20 by pouring a resin 24m into the case 22 housing a plurality of coils 26, and arranging the plurality of coil modules 20 in a movable direction. It includes fixing to the beam member 30 and electrically connecting the wiring member 34 to the coil 26.

According to this aspect, when the design is performed by changing the movable stroke of the linear motor 100, it is possible to cope with the change by changing the number of coil modules 20 to be connected, so that the design can be standardized and the design man-hours can be reduced. When manufacturing by changing the movable stroke of the linear motor 100, the number of coil modules 20 to be connected can be changed, so that molds, jigs and manufacturing equipment can be shared.

Forming the coil module 20 may include fixing the lid 22c to the case body 22b into which the resin 24m is poured. In this case, since the lid 22c is fixed to the case main body 22b, gas generation from the resin 24m can be suppressed.

As described above, the example of the embodiment of the present invention has been described in detail. The above-described embodiments are merely specific examples for carrying out the present invention. The contents of the embodiments do not limit the technical scope of the present invention, and many design changes such as changes, additions, deletions, and the like of components are made without departing from the spirit of the invention defined in the claims. Is possible. In the above-described embodiment, the contents that can be changed in design have been described with the notation “in the embodiment”, “in the embodiment”, etc., but there is no such description. The content is not unacceptable to design changes. Moreover, the hatching given to the cross section of drawing does not limit the material of the hatched object.

Hereinafter, modified examples will be described. In the drawings and description of the modification, the same reference numerals are given to the same or equivalent components and members as those in the embodiment. The description overlapping with the embodiment will be omitted as appropriate, and the configuration different from the embodiment will be described mainly.

(First modification)
FIG. 6 is a cross-sectional view showing a linear motor 200a according to a first modification, and corresponds to FIG. The linear motor 200a is different from the linear motor 100 in that the second beam member 31 is not provided, and the other configurations are the same. It is not essential to provide the second beam member 31.

(Second modification)
In the linear motor 100, the example in which the beam member 30 and the second beam member 31 are not coupled has been described. However, the present invention is not limited to this. FIG. 7 is a cross-sectional view showing a linear motor 200b according to a second modification, and corresponds to FIG. The linear motor 200b is different from the linear motor 100 in that a beam member 30B, a second beam member 31B, and a spacer 35 are provided instead of the beam member 30 and the second beam member 31, and the other configurations are the same. is there. The beam member 30B and the second beam member 31B project from the coil module 20 in the negative direction along the Y axis, and a spacer 35 is provided between these projecting portions. The beam member 30B and the second beam member 31B are integrally coupled with the spacer 35 interposed therebetween.

In the linear motor 200b, the beam member 30B and the second beam member 31B have an entry portion 30e that enters the magnetic gap 60. The entry portion 30e may be, for example, a plate-like portion that extends in the X-axis direction and the Y-axis direction and is thin in the Z-axis direction. The entry portion 30e is provided so as to cover all or part of the coil module 20. By having the approach part 30e, the curvature of the coil module 20 can be suppressed. The approach portion 30e can be applied to the embodiment and other modifications.

(Third Modification)
FIG. 8 is a cross-sectional view showing a linear motor 200c according to a third modification, and corresponds to FIG. The linear motor 200c is different from the linear motor 200b in that it includes a beam member 30C instead of the beam member 30B, the second beam member 31B, and the spacer 35, and the other configurations are the same. The beam member 30C has a shape in which the beam member 30B, the second beam member 31B, and the spacer 35 are seamlessly integrated.

(Fourth modification)
In the embodiment, the example in which the process of manufacturing the coil module 20 and the process of connecting the coil module 20 are continuously provided has been described, but the present invention is not limited to this. Moreover, it is not essential to provide the above-mentioned beam member. For example, in the process of manufacturing the coil module 20, the coil module 20 that does not include a beam member may be manufactured. The coil module 20 without the beam member manufactured in this way may be stored for each specification such as size. In this case, the step of connecting the coil modules 20 may be provided in another factory. The stored coil module 20 having a desired specification may be transported to another factory, and the coil module 20 may be connected there.

(Other variations)
The linear motor 100 may be configured by combining coil modules 20 having different numbers of coils.
The linear motor 100 may include a linear coil module 20 and a curved coil module.
The pair of yokes 54 and the spacers 56 may be formed seamlessly and integrally.
One of the pair of field magnets 52 sandwiching the coil module 20 may not be provided.
Each of the above-described modifications has the same operations and effects as the embodiment.

10 ·· Stator, 18 · Coil, 20 · Coil module, 22 · Case, 22b · Case body, 22c ·· Lid, 24 · Coil assembly, 24m ·· Resin, 26 · Coil, 30・・ Beam member, 31 ・・ Second beam member, 34 ・・ Wiring member, 36 ・・ Connector, 50 ・・ Mover, 52 ・・ Field magnet, 54 ・・ Yoke, 60 ・・ Magnetic gap, 100 ..Linear motor.

Claims

A mover including a field magnet;
A stator including a plurality of coil modules coupled in a movable direction of the mover;
With
The linear motor, wherein the coil module includes a plurality of coils arranged in the movable direction.
2. The linear motor according to claim 1, wherein the number of coils of the plurality of coils is an integer multiple of three.
3. The linear motor according to claim 1, wherein the number of coils of the plurality of coils is 6 or less.
The linear motor according to any one of claims 1 to 3, wherein the coil module includes a connector including electrodes electrically connected to the plurality of coils.
A method of manufacturing the linear motor according to claim 1,
Housing a plurality of coils in a case;
Pouring resin into a case containing a plurality of coils to form a coil module;
Arranging a plurality of coil modules in the movable direction and fixing them to the beam member;
Electrically connecting a wiring member to the coil;
The manufacturing method of the linear motor characterized by including.
Forming a coil module
The method for manufacturing a linear motor according to claim 5, further comprising fixing a lid to a case into which resin is poured.