JP2024042354A - Moving coil type linear motor - Google Patents

Abstract

[Problem] To provide a moving coil type linear motor in which the mover is lightweight and compact and can efficiently dissipate heat generated in the coil. [Solution] The motor has a stator having a magnetic field generating member with a magnetic gap that generates a magnetic field in a specified direction, and a mover 3 having a coil in which a current flows in a direction crossing the magnetic field, the coil is wound around a bobbin structure 60, and rod-shaped cooling fins 65 are arranged inside the coil in a plan view. [Selected Figure] Figure 3

Description

The present invention relates to a cooling structure for a moving coil type linear motor that uses a coreless type armature as a movable element.

2. Description of the Related Art In semiconductor manufacturing equipment, liquid crystal manufacturing equipment, or testing equipment for semiconductor elements, liquid crystal displays, and the like, a two-axis stage device, a so-called XY stage, is used as a conveyance device for various parts. The XY stage includes an X stage that moves in a predetermined direction (X direction) with respect to a surface plate, and a Y stage that moves in a direction perpendicular to the X direction (Y direction).
The X stage and the Y stage include a drive section driven by a linear motor or the like. A linear motor includes a magnetic field generating member having a U-shaped cross section and having a permanent magnet supported by a yoke so that its north and south poles face each other, and a coil member having a coil that crosses the inside of the magnetic field.
A linear motor allows a magnetic field generating member and a coil member to move relative to each other through interaction between a magnetic field generated by a permanent magnet and a magnetic field generated in the coil by passing a current through the coil.

For example, the linear motor described above has a structure in which the magnetic field generating member is the stator and the coil member is the mover, and in order to increase the speed of the conveyance device, it is common to increase the current flowing through the coil. is being carried out.
When the current flowing through the coil is increased, the amount of heat generated by the coil increases, causing problems such as an increase in electrical resistance and thermal deformation of surrounding members.
As a countermeasure against this problem, a technique has been disclosed in which a jacket member having a space formed on both sides of a mold member containing the coil is attached, and a refrigerant is passed through the space formed by the mold member and the jacket member to cool the coil (Patent Document 1).

Furthermore, a technique has been proposed in which heat generated in a coil is radiated using a heat sink (Patent Document 2).

Japanese Patent Application Publication No. 2017-184492 Japanese Patent Application Publication No. 9-19129

According to the technology disclosed in Patent Document 1, it is possible to efficiently remove the heat generated by the coil, but the structure for flowing the refrigerant becomes complicated, which raises concerns about cost increase and increases weight. .

The technique disclosed in Patent Document 2 uses a heat sink, which makes it possible to dissipate the heat generated by the coil with a simple structure, but it is difficult to make it compact.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a moving coil type linear motor in which the moving element is lightweight and compact, and the heat generated by the coil can be efficiently radiated.

The moving coil type linear motor according to the present invention has a stator having a magnetic field generating member and a moving element having a coil, and is characterized in that, in a plan view, it has cooling fins on the inside of the coil.

The coil is wound around a bobbin structure, and the cooling fins are provided on the bobbin structure.

The cooling fins are provided on both planes of the bobbin structure.

The cooling fins are arranged in a staggered manner in a side view of the bobbin structure.

The cooling fin is provided on one plane of the bobbin structure.

The bobbin structure has a body portion and a flange portion, and the cooling fins are provided within the body portion.

The bobbin structure is characterized in that a surface in contact with the coil is coated with an insulator.

The coil is wound around a bobbin, the cooling fins are provided on one plane of a plate-like part of the fin structure, and the bobbin structure is formed by combining the bobbin and the fin structure. The cooling fin is arranged to penetrate through a through hole formed in the bobbin.

The cooling fins are provided on both planes of the plate-shaped portion of the fin structure, and the bobbin structure is configured by combining a pair of the bobbins and the fin structure. .

The bobbin is characterized in that a surface in contact with the coil is coated with an insulator.

The cooling fins are rod-shaped, parallel to the direction of movement of the movable element, and arranged at equal intervals.

The cooling fin is characterized in that it is divided and provided in the movable direction of the movable element.

The cooling fins are provided separately in the movable direction of the movable element, and are arranged in a staggered manner when the bobbin structure is viewed from above.

A plurality of the bobbin structures are arranged in a movable direction of the movable element, and the cooling fins of each bobbin structure are arranged in a staggered manner when the movable element is viewed from above.

The bobbin structure is characterized in that it is molded with a mold member except for the cooling fins or the cooling fins and a plane on which the cooling fins are arranged.

The movable element has a holder that supports the mold member, and the holder has unevenness on a side surface parallel to the moving direction of the movable element.

According to the present invention, it is possible to provide a moving coil type linear motor in which the moving element is lightweight and compact and can efficiently radiate heat generated by the coil.

1 is a top view of a linear motor according to an embodiment of the invention. 2 is a sectional view taken along line AA in FIG. 1. FIG. FIG. 1 is a perspective view showing an example of a mover according to an embodiment of the present invention. 4 is a partially see-through view showing the arrangement of a bobbin structure in the mover shown in FIG. 3 . It is a perspective view of a bobbin structure. It is a top view (a) and a side view (b) of a bobbin structure. 1A is a plan view and FIG.1B is a side view of the bobbin structure with a coil wound thereon, with FIG.1A being a partially see-through view. It is a top view (a) and a side view (b) which show another embodiment of a bobbin structure. 9 is a perspective view showing an example of a mover using the bobbin structure shown in FIG. 8. FIG. It is a top view (a) and a side view (b) which show another embodiment of a bobbin structure. 11 is a sectional view showing a movable element 3 using the bobbin structure shown in FIG. 10. FIG. It is a perspective view showing another embodiment of a bobbin structure. It is a perspective view showing another embodiment of a bobbin structure. It is a perspective view showing another embodiment of a bobbin structure. FIG. 7 is a diagram showing another embodiment of a bobbin structure, in which a top view (a) and a side view (b) of a bobbin, a side view (c) of a fin structure, and a bobbin structure in which a bobbin and a fin structure are combined. It is a side view (d) of. They are a perspective view (a) of a bobbin, a perspective view (b) of a fin structure, and a perspective view (c) of a bobbin structure in which the bobbin and fin structure are combined in the bobbin structure shown in FIG. 15. 1A and 1B are diagrams showing another embodiment of the bobbin structure, and are a plan view and a side view of the bobbin (a), a side view of the fin structure (c), and a side view of the bobbin structure combining the bobbin and the fin structure (d). They are a perspective view (a) of a bobbin in the bobbin structure shown in FIG. 17, a perspective view (b) of a fin structure, and a perspective view (c) of a bobbin structure in which the bobbin and the fin structure are combined. It is a perspective view showing another embodiment of a mover.

The present invention will be described below based on embodiments thereof.

1 is a top view of a linear motor 10 according to an embodiment of the invention, FIG. 2 is a sectional view taken along line AA in FIG. 1, FIG. 3 is a perspective view showing an example of a mover according to an embodiment of the invention, and FIG. is a partially transparent view showing the arrangement of the bobbin structure in the mover shown in FIG. 3 (dashed lines indicate the bobbin structure), FIG. 5 is a perspective view of the bobbin structure, and FIG. ) and side view (b), and FIG. 7 is a plan view (a) and side view (b) of the bobbin structure with a coil wound around it, and the plan view (a) in FIG. 7 is a partially transparent view ( The broken line indicates the coil).

A moving coil type linear motor of the present invention includes a stator having a magnetic field generating member and a movable element having a coil. Specifically, the linear motor 10 of the present invention includes a stator 1 having a plurality of divided units 2 including a magnetic field generating member 22, and a mover having a coil driven within a magnetic gap g formed inside the stator 1. It has 3.
The linear motor 10 of the present invention has a plurality of divided units 2 connected along the movable direction of the movable element 3 (vertical (X) direction in FIG. 1), and each divided unit 2 has a similar structure. However, the lengths do not need to be the same. As shown in FIG. 2, the movable element 3 includes a coil member 4 having a multiphase coil, which will be described later, and a holder 5 that supports the coil member 4.
According to the linear motor 10 of the present invention, the movable element 3 is provided with a magnetic field detection element such as a Hall element to detect the magnetic pole position and change the direction of the current flowing through each coil, thereby moving the movable element 3 in the movable direction. It can be moved. That is, the linear motor 10 of the present invention is a moving coil type linear motor.

The divided unit 2 that constitutes the stator 1 includes a non-magnetic frame 21 and a permanent magnet that is a magnetic field generating member 22. The non-magnetic frame 21 has a base member 211 and a pair of side members 212. The base member 211 has a prismatic shape, and a flat side member 212 is arranged on the side. The non-magnetic frame 21 has a U-shaped cross section. The base member 211 and side members 212 that constitute the non-magnetic frame 21 are made of a non-magnetic material such as an aluminum alloy.
A groove 213 extending in the movable direction of the movable element 3 is formed in the base member 211 . The groove 213 is provided at the center of the base member 211 in the width direction. The depth and width of the groove 213 are set to accommodate a portion of the coil member 4, which will be described later.

The magnetic field generating member 22 includes a yoke 23, a main magnet 24, and an auxiliary magnet 25. The yoke 23 has a flat plate shape and is made of a ferromagnetic material such as SS material. A plurality of main magnets 24 are fixed to one surface of the yoke 23 at predetermined intervals along the movable direction of the movable element 3. The main magnet 24 is magnetized in the thickness direction (direction perpendicular to the movable direction of the movable element 3).
The magnetization direction of the auxiliary magnet 25 is parallel to the movable direction of the movable element 3 and perpendicular to the magnetization direction of the main magnet 24. The auxiliary magnets 25 are arranged so that magnetic poles of the same polarity face each other with the main magnet 24 in between. The other surface of the yoke 23 is fixed to a side member 212 of the nonmagnetic frame 21. The magnetic field generating member 22 has the above configuration and has a U-shaped cross section.
The main magnet 24 and the auxiliary magnet 25, which face each other with a magnetic gap in between, are arranged in a Halbach arrangement such that different poles face each other. The direction of the magnetic field in the magnetic gap g is the direction in which the magnets face each other.
As the main magnet 24 and the auxiliary magnet 25, known permanent magnets can be used. One example is rare earth magnets. Rare earth magnets include R-T-B whose essential components are R (R is an element consisting of at least one selected from rare earth elements such as Nd), T (T is Fe or Fe and Co), and B (boron). A sintered magnet is preferred.
In order to make the linear motor smaller and lighter, and more efficient and energy-saving (improving energy efficiency), it is preferable to use RTB-based sintered magnets for the main magnet 24 and the auxiliary magnet 25.

The mover 3 includes a coil member 4 and a holder 5. The coil member 4 of the mover 3 is disposed within a magnetic gap g formed in the stator 1. The holder 5 is connected to a driven member (not shown). The driven member is, for example, a linear type bearing.

Embodiment 1
The coil member 4 will be explained in detail below. FIG. 3 is a perspective view showing an example of the movable element 3 according to the embodiment of the invention. FIG. 4 is a partially transparent view showing the arrangement of the bobbin structure 60 in the movable element 3 shown in FIG. The movable element 3 includes a coil member 4 and a holder 5. The coil member 4 includes a bobbin structure 60 and a mold member 41 that molds and fixes the bobbin structure 60. A plurality of bobbin structures 60 (three in FIGS. 3 and 4) are arranged at equal intervals along the movable direction of the movable element 3 and fixed with a mold member 41.
The mold member 41 is made of a resin material such as FRP, and is molded by a known method after the bobbin structures 60 are arranged at equal intervals. 5 is a perspective view showing the bobbin structure 60, FIG. 6 is a plan view (a) and a side view (b) of the bobbin structure 60, and FIG. 7 is a plan view of the bobbin structure 60 with the coil wound ( a) and a side view (b). The plan view (a) is a partially transparent view, and the broken lines indicate the coils. The conducting wire forming the coil is coated with a known insulating coating such as enamel.

The bobbin structure 60 includes a body portion 62 and a pair of collar portions 61, and has a rectangular shape in plan view. A coil 63 is wound in a space formed by the pair of collar parts 61 and the outer peripheral surface of the body part 62.
The inner side of the pair of collar portions 61 and the outer peripheral surface of the body portion 62 in the space, that is, the surface in contact with the coil may be coated with an insulating resin 64. By coating with resin 64, insulation can be ensured even if there is damage such as a scratch on the insulation coating of the conductor.
In the embodiments of the present invention, the bobbin structure refers to a structure in which a bobbin and cooling fins (including a fin structure described below) are combined. The bobbin and the cooling fins may be integrated, or the bobbin and the cooling fins may be joined together. The structure and shape of the bobbin, the resin coating of the insulator, etc. are the same as those of the bobbin structure described above.
Cooling fins (hereinafter simply referred to as A fin (sometimes referred to as a "fin") 65 is arranged to protrude from both planes.
Here, the above-mentioned "inside the coil 63 in plan view" means that the cooling fins are arranged in the area inside the coil (in other words, the area inside the outer periphery of the body) shown by the broken line in FIG. 7(a). All you have to do is stay there. For example, as shown in Embodiment 1 shown in FIG. 7, the cooling fins are arranged so as to protrude from both planes of the bobbin structure (outside the body of the bobbin structure), or as shown in FIG. 14 described later. When the cooling fins are arranged inside the body of the bobbin structure as in the sixth embodiment, furthermore, as in the seventh embodiment shown in FIG. 16 described later, the cooling fins are arranged inside the body of the bobbin structure. A case where the coil 63 is disposed both inside and outside the body is also included in "inside the coil 63 in plan view."

The fins 65 are rod-shaped (prismatic) with a square cross section, and the length direction is the width direction (movement direction of the movable element 3) of both planes of the bobbin structure 60 (the outer surfaces of the pair of flanges 61). are arranged parallel to each other. Further, a plurality of fins 65 are arranged in parallel and at equal intervals in the length direction (direction perpendicular to the width direction) of both planes of the bobbin structure 60 (outer surfaces of the pair of flanges 61). There is.
The bobbin structure 60 is preferably made of copper, aluminum, or an alloy thereof, and more preferably made of copper or a copper alloy.
By using these metals and alloys, the heat generated by the coil can be efficiently dissipated.
In FIG. 3, only the fins 65 of the bobbin structure 60 protrude from the plane of the coil member 4 (molded member 41). (plane) may be exposed on the plane of the coil member 4 (mold member 41).
The bobbin structure 60 is sufficiently fixed to the mold member 41 because the space formed by the pair of collar parts 61 and the outer peripheral surface of the body part 62 after winding the coil 63 is also molded.

With this configuration, the heat generated by the coil 63 is radiated from the bobbin structure 60 through the fins 65.

Embodiment 2
FIG. 8 shows another embodiment 2 of the bobbin structure. FIG. 8 is a plan view (a) and a side view (b) of the bobbin structure 70.
Only the parts different from the bobbin structure 60 will be explained. The difference between the bobbin structure 70 and the bobbin structure 60 is that, as shown in the side view (b), between adjacent fins 75 on one plane of the bobbin structure 70, fins 76 on the other plane are arranged. They differ in some respects. That is, they are arranged in a staggered manner when viewed from the side.
FIG. 9 shows an example of a mover 3 using the bobbin structure shown in the second embodiment. In FIG. 9, the bobbin structure 70 located in the center of the figure is arranged so that the plane on the fin 76 side is on the front side in the figure, and the bobbin structure 70 located on the left and right sides in the figure is arranged so that the plane on the fin 75 side is in the figure. It is placed so that it is in front of you. That is, the fins 75 and fins 76 of each bobbin structure 70 arranged in the movable direction of the movable element 3 are arranged in a staggered manner in a plan view.
With such a structure, when the movable element 3 moves, the air flow becomes smooth and the cooling effect can be enhanced.

Embodiment 3
FIG. 10 shows another embodiment 3 of the bobbin structure. FIG. 10 is a plan view (a) and a side view (b) of the bobbin structure 80.
The only difference from the bobbin structure 60 is that the fins 85 are erected only on one side, and the rest is the same as in FIG.
FIG. 11 shows a linear motor having a movable element 3 using a bobbin structure 80, and is a sectional view corresponding to the position AA in FIG.
The difference from FIG. 2 is that the fins 85 for heat radiation protrude only from one side of the movable element 3.

Embodiment 4
FIG. 12 shows another embodiment 4 of the bobbin structure. The difference from the bobbin structures 60, 70, and 80 shown in FIGS. 6, 8, and 10 is that the fins 95 are divided into two in the moving direction of the movable element.
The fins 95 may be on one side of the bobbin structure, like the bobbin structures 60, 70, or 80, or on both sides.
According to the fourth embodiment, since the fins 95 are arranged in segments, the specific surface area of the fins 95 is increased, an improvement in the heat dissipation effect can be expected, and the weight of the bobbin 90 can be reduced.

Embodiment 5
FIG. 13 shows another embodiment 5 of the bobbin structure. In the bobbin structure shown in FIG. 13, the fins 105 are divided into three in the movable direction of the mover, and are arranged in a staggered manner in the plane of the bobbin structure 100.
The fins 105 may be arranged on one plane of the bobbin structure 100, or may be arranged on both planes.
According to the fourth embodiment, since the fins 105 are divided into three parts and arranged in a staggered manner, it is possible to reduce the weight of the bobbin structure 100 and to improve the heat dissipation effect.

Embodiment 6
FIG. 14 shows another embodiment 6 of the bobbin structure. In the bobbin structure of FIG. 14, the fins 115 do not protrude from the bobbin structure 110 and are disposed within the body of the bobbin structure 110.
The bobbin structure 110 has a through hole 120 inside the coil in plan view, in other words, inside the outer periphery of the body part in plan view, and a plurality of fins 115 are provided in the through hole 120 in the movable direction of the mover. are arranged at equal intervals in a direction parallel to the The through hole 120 is formed to penetrate through the winding portion and the plate-like portion.

Embodiment 7
Another embodiment 7 is shown in FIGS. 15 and 16. FIG. 15 shows a top view (a) and a side view (b) of the bobbin 400, a side view (c) of the fin structure 450, and a side view (d) of the bobbin structure 480 in which the bobbin 400 and the fin structure 450 are combined. be.
In Embodiment 7, a fin structure 450 constituting a fin and a bobbin 400 are separated and combined to form a bobbin structure 480.
The bobbin 400 is made of resin, and includes a body portion 420 and a pair of collar portions 410, and has a through hole 430 passing through the body portion 420 and the pair of collar portions 410.
The through holes 430 are sized and spaced such that the fins 470 disposed on the fin structure 450 can be inserted therein.
The fin structure 450 includes a flat base 460 and fins 470 erected on the base 460. A plurality of fins 470 are arranged on the base 460 parallel to the movable direction of the movable element and at equal intervals.
By adopting such a structure, the structure of each component can be simplified, leading to cost reduction.

Embodiment 8
Another embodiment 8 is shown in FIGS. 17 and 18. FIG. 17 shows a top view (a) and a side view (b) of the bobbin 500, a side view (c) of the fin structure 550, and a side view (d) of the bobbin structure 580 in which the bobbin 500 and the fin structure 550 are combined. be.
The difference from the seventh embodiment is that fins 570 are arranged upright on both planes of the base 560 of the fin structure 550, and a bobbin structure 580 is formed by a pair of bobbins 500 sandwiching the fin structure 550 from both sides. That's true.
The structure of the bobbin 500 is similar to the bobbin 400 of the seventh embodiment.
The through holes 530 are sized and spaced such that the fins 570 disposed on the fin structure 550 can be inserted therein.
The fin structure 550 includes fins 570 erected on both planes of a base 560 on a flat plate. A plurality of fins 570 are arranged on both sides of the base 460 in parallel to the movable direction of the movable element and at equal intervals.
In the eighth embodiment, the fins may be arranged in a staggered manner when viewed from the side, as in the second embodiment shown in FIG.
By adopting such a structure, the structure of each component can be simplified, leading to cost reduction.

Embodiment 9
Another embodiment 9 is shown in FIG. FIG. 19 is a perspective view showing another embodiment of the mover.
In the mover shown in FIG. 19, a groove 300 is formed on the side surface of the holder 5 along the movable direction of the mover.
By providing such a groove, it becomes possible to efficiently dissipate the heat transmitted to the holder 5 due to the coil.

The disclosed embodiments should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims rather than the above description, and it is intended that all changes within the meaning and range equivalent to the claims are included.

10 Linear motor 1 Stator 2 Split unit 3 Movable element 22 Magnetic field generating member 4 Coil member 41 Molded member 5 Holder 60, 70, 80, 90, 100, 110, 480, 580 Bobbin structure 65, 75, 85, 95, 105, 115, 470, 570 (Cooling) fin

Claims (16)

A moving coil type linear motor comprising a stator having a magnetic field generating member and a movable element having a coil, and having cooling fins inside the coil in plan view. The moving coil linear motor according to claim 1, wherein the coil is wound around a bobbin structure, and the cooling fins are provided on the bobbin structure. The moving coil linear motor according to claim 2, wherein the cooling fins are provided on both planes of the bobbin structure. 4. The moving coil type linear motor according to claim 3, wherein the cooling fins are arranged in a staggered manner when viewed from the side of the bobbin structure. The moving coil linear motor according to claim 2, wherein the cooling fins are provided on one plane of the bobbin structure. The moving coil type linear motor according to claim 2, wherein the bobbin structure has a body portion and a flange portion, and the cooling fins are provided within the body portion. The moving coil type linear motor according to claim 2, characterized in that the surface of the bobbin structure that contacts the coil is covered with an insulator. The coil is wound around a bobbin, the cooling fins are provided on one plane of a plate-like part of the fin structure, and the bobbin structure is formed by combining the bobbin and the fin structure. 2. The moving coil type linear motor according to claim 1, wherein the cooling fin is arranged to pass through a through hole formed in the bobbin. The cooling fins are provided on both planes of the plate-shaped portion of the fin structure, and the bobbin structure is configured by combining a pair of the bobbins and the fin structure. A moving coil type linear motor according to claim 8. 9. The moving coil type linear motor according to claim 8, wherein the surface of the bobbin in contact with the coil is coated with an insulator. The movable coil type linear motor according to claim 2 or 8, wherein the cooling fins are rod-shaped, and a plurality of cooling fins are arranged in parallel to the movable direction of the movable element at equal intervals. . 9. The movable coil type linear motor according to claim 2, wherein the cooling fins are divided and provided in a movable direction of the movable element. 9. The moving coil type linear motor according to claim 2, wherein the cooling fins are divided in the movable direction of the movable element and are arranged in a staggered manner when the bobbin structure is viewed from above. 9. A plurality of the bobbin structures are arranged in a movable direction of the movable element, and the cooling fins of each bobbin structure are arranged in a staggered manner when the movable element is viewed from above. The moving coil type linear motor described in . The movable coil type according to claim 2 or 8, wherein the bobbin structure is molded with a mold member except for the cooling fins or the cooling fins and a plane on which the cooling fins are arranged. linear motor. 16. The moving coil type linear motor according to claim 15, wherein the movable element has a holder that supports the mold member, and a side surface of the holder has unevenness parallel to the moving direction of the movable element.