Linear motor

Abstract

To provide a linear motor which can accurately measure a temperature of a coil in the linear motor including a coil member having a mold member and a jacket member.SOLUTION: The linear motor comprises: a magnetic field generation member having a magnetic gap in which a magnetic field is generated in a predetermined direction; and a coil member having a coil in which current flows in a direction crossing the magnetic field, a mold member including the coil therein and having a rectangular cross section; and a jacket member fixed to a surface on a side facing the magnetic field generation member of the mold member, in which a space in which coolant can flow is formed between the mold member and the jacket member, wherein the coil member has a temperature sensor which measures a temperature of the coil, and a heat conduction member which conducts heat generated from the coil to the temperature sensor.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present invention relates to a linear motor capable of accurately measuring the temperature of an armature coil.

Background Art

[0002] In semiconductor manufacturing equipment, liquid crystal manufacturing equipment, or inspection equipment for semiconductor elements, liquid crystal displays, etc., a two-axis stage device, a so-called X-Y stage, is used as a transfer device for various components. The X-Y stage includes an X stage that moves in a predetermined direction (X direction) with respect to a base plate and a Y stage that moves in a direction (Y direction) orthogonal to the X direction. The X stage and the Y stage include drive units driven by a linear motor or the like. The linear motor includes a magnetic field generating member having a permanent magnet supported by a yoke so that the N pole and the S pole face each other, and a coil member having a coil that crosses the magnetic field. The linear motor can relatively move the magnetic field generating member and the coil member by the interaction between the magnetic field by the permanent magnet and the magnetic field generated in the coil when an electric current is passed through the coil.

[0003] The linear motor as described above has, for example, a structure in which the magnetic field generating member is a stator and the coil member is a mover. In such a linear motor, in order to increase the speed of the transfer device, it is generally performed to increase the current flowing through the coil. When the current flowing through the coil is increased, problems such as an increase in the heat generation amount of the coil, an increase in electrical resistance, and thermal deformation of peripheral members occur. As a countermeasure, a jacket member is attached so that spaces are formed on both sides of a mold member that encloses the coil, and the coil is cooled by passing a refrigerant through the space formed by the mold member and the jacket member (Patent Document 1).

[0004] In addition, a technique for adjusting the amount of refrigerant flowing according to the heat generation amount of the coil when cooling the coil has been proposed (Patent Document 2).

Prior Art Documents

Patent Document

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] Patent Document 1 does not disclose the technology of temperature measurement, and it is unclear how the temperature measurement is carried out.

[0007] The technology disclosed in Patent Document 2 is a cooling method using a cooling pipe, and a sensor is arranged in the immediate vicinity of the coil, but the temperature measurement method in the coil member using the mold member and the jacket member is not disclosed.

[0008] Conventionally, the inventors have provided a notch in a part of the mold member constituting the mover in a linear motor similar to the movable coil type linear motor according to Patent Document 1, and placed a temperature sensor to measure the temperature of the coil (see FIG. 3). However, a problem has occurred in that the distance between the coil and the temperature sensor is large, and the temperature rise due to the coil cannot be sufficiently detected.

[0009] The present invention has been made in view of such circumstances, and an object thereof is to provide a linear motor capable of accurately measuring the temperature of a coil in a linear motor including a coil member having a mold member and a jacket member.

Means for Solving the Problems

[0010] The linear motor according to the present invention includes a magnetic field generating member having a magnetic gap in which a magnetic field is generated in a predetermined direction, a coil through which a current flows in a direction crossing the magnetic field, a mold member that encloses the coil and has a rectangular cross section, and a jacket member fixed to a surface of the mold member on a side facing the magnetic field generating member, and includes a coil member in which a space through which a refrigerant can flow is formed between the mold member and the jacket member, and the coil member is characterized by having a temperature sensor that measures the temperature of the coil and a heat conducting member that transmits heat generated from the coil to the temperature sensor.

[0011] According to the present invention, the temperature of the coil of the linear motor can be accurately measured.

[0012] In the linear motor according to the present invention, the mold member includes a coil enclosing portion that encloses the coil and a base portion that is connected to the coil enclosing portion, the temperature sensor is disposed in a notch formed in the base portion, and a plate-shaped heat conducting member extends from the temperature sensor into the space through which the refrigerant can flow.

[0013] According to the present invention, the temperature of the coil of the linear motor can be accurately measured.

[0014] In the linear motor according to the present invention, the mold member includes a coil enclosing portion that encloses the coil and a base portion that is connected to the coil enclosing portion, the temperature sensor is disposed in a notch formed in the base portion, and the notch A hole at the bottom has, and the Hole portion A rod shaped heat conducting member is disposed.

[0015] According to the present invention, the temperature of the coil of the linear motor can be accurately measured.

[0016] The linear motor according to the present invention, wherein the mold member comprises a coil containing portion for containing the coil and a base portion connected to the coil containing portion, the temperature sensor is disposed in a notch formed in the base portion, and the notch At the bottom of the coi To the loop reaches Penetrate has a hole portion, and the Penetrate hole portion A rod is provided with a rod-shaped heat conductive member, and a heat conductive grease is interposed between the rod-shaped heat conductive member and the coil.

[0017] According to the present invention, the temperature of the coil of the linear motor can be accurately measured.

[0018] The linear motor according to the present invention is characterized in that the heat conductive member is made of copper.

[0019] According to the present invention, the temperature of the coil of the linear motor can be accurately measured.

[0020] The linear motor of the present invention is a movable coil type linear motor in which the coil is a mover and the magnetic field generating member is a stator.

[0021] According to the present invention, the temperature of the coil constituting the mover of the movable coil type linear motor can be accurately measured.

[0022] The linear motor of the present invention is characterized in that the coil is a coil series in which a plurality of single coils are connected in series.

[0023] According to the present invention, the temperature of the coil of the linear motor can be accurately measured.

Advantages of the Invention

[0024] According to the present invention, the temperature of the coil of the linear motor can be accurately measured.

Brief Description of the Drawings

[0025]

Figure 1

Figure 2

Figure 3

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Figure 6

Figure 7

Figure 8

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Figure 10

Figure 11

Figure 12

[0026] Hereinafter, the present invention will be described in detail based on the drawings showing its embodiments.

[0027] FIG. 1 is a plan view of a linear motor according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the A-A axis of FIG. 1, FIG. 3 is a perspective view showing an example of a coil member, FIG. 4 is an exploded perspective view showing an example of a coil member, FIG. 5 is a perspective view showing an example of a temperature sensor, FIG. 6 is a plan view showing an example of a coil member, and FIG. 7 is a sectional view taken along the line B-B of FIG. 6. The linear motor of the present invention includes a stator 1 having a plurality of divided units 3 and a mover 2 having a multilayer coil driven in a magnetic gap g formed therein. This linear motor is formed by connecting a plurality of divided units 3 along the moving direction of the mover 2 (the vertical direction in FIG. 1), and each divided unit 3 has the same structure. However, the lengths do not necessarily have to be the same. As shown in FIG. 2, the mover 2 includes a coil member 4 having a polyphase coil described later and a holder 5 for instructing it. The holder 5 is connected to a driven member (not shown). According to this linear motor, a magnetic field detection element such as a Hall element is provided on the mover 2 to detect the magnetic pole position, and by changing the direction of the current flowing through each coil, the mover 2 can be moved in the moving direction.

[0028] The divided unit 3 constituting the stator 1 includes a non-magnetic frame 31 and a permanent magnet as a magnetic field generating member 32. The non-magnetic frame 31 has a base member 311 and a pair of side members 312. The base member 311 has a prismatic shape, and flat plate-shaped side members 312 are arranged on the sides. The non-magnetic frame 31 has a U-shaped cross section. The base member 311 and the side member 312 constituting the non-magnetic frame are made of a non-magnetic material such as an aluminum alloy, for example. A groove 313 extending in the moving direction of the mover 2 is formed in the base member 311. The groove 313 is provided at the central portion in the width direction of the base member 311. The width and depth of the groove 313 are set to dimensions into which a part of the coil member 4 described later can fit.

[0029] The magnetic field generating member 32 includes a yoke 33, a main magnet 34, and an auxiliary magnet 35. The yoke 33 has a flat plate shape and is made of a ferromagnetic material such as an SS material. A plurality of main magnets 34 are fixed at predetermined intervals along the moving direction of the mover 2 on one surface of the yoke 33. The magnetization direction of the main magnet 34 is in the thickness direction (the direction perpendicular to the moving direction of the mover 2). The N poles and S poles of the main magnet 34 are arranged alternately along the moving direction of the mover 2. The magnetization direction of the auxiliary magnet 35 is parallel to the moving direction of the mover 2 and orthogonal to the magnetization direction of the main magnet 34. The auxiliary magnet 35 is arranged such that the like-pole magnetic poles face each other with the main magnet 34 interposed therebetween. The other surface of the yoke 33 is fixed to the side member 312 of the non-magnetic frame 31. The main magnet 34 and the auxiliary magnet 35 facing each other across the magnetic gap g are arranged such that the opposite magnetic poles face each other, forming a Halbach array. The direction of the magnetic field in the magnetic gap g is the direction in which the magnets face each other. Known permanent magnets can be used for the main magnet 34 and the auxiliary magnet 35. As an example, a rare-earth magnet. R (R is an element composed of at least one selected from rare-earth elements such as Nd). T (T is Fe or Fe and Co) and B (boron) are essential components of the R-T-B sintered magnet, which is preferable as the main magnet 34 and the auxiliary magnet 35. Here, the R-T-B sintered magnet is an indispensable material for reducing the size and weight of the linear motor and improving its efficiency and energy conservation (improvement of energy efficiency).

[0030] The mover 2 includes a holder 5 and a coil member 4. The coil member 4 of the mover 2 is driven within the magnetic gap g formed in the stator 1. The holder 5 is connected to a driven member (not shown). The linear motor 10 can move the mover 2 by providing a magnetic field detection element (not shown) on the mover 2 to detect the magnetic pole position and changing the direction of the current flowing through each coil. This linear motor 10 is a moving coil type linear motor having a mover 2 including a coil. Hereinafter, the coil member 4 will be referred to as a moving coil member 4.

[0031] Next, the moving coil member 4 will be described in detail. FIG. 3 is a perspective view showing an example of the moving coil member 4, and FIG. 4 is an exploded perspective view showing an example of the moving coil member 4. The moving coil member 4 includes a mold member 41, a pair of jacket members 42, and a multilayer coil 6. The moving coil member 4 has a rectangular plate shape.

[0032] The mold member 41 has a T-shaped cross-section and is composed of a coil-containing portion 41b that encloses the multi-layer coil 6 and a base portion 41a connected to the coil-containing portion. Jacket members 42 are fixed to both side surfaces of the coil-containing portion 41b. The mold member 41 is formed by molding the coil with resin. The mold member 41 (base portion 41a) is provided with a refrigerant inlet 411 and a discharge port 414. The inlet 411 and the discharge port 414 extend in the vertical direction. The mold member 41 is highly rigid, has electrical insulation properties, and has resistance to refrigerants. For example, glass epoxy or the like is used.

[0033] In the case of a three-layer coil, the multi-layer coil 6 is arranged such that six flat-shaped hollow coils are arranged as a U-phase coil, a V-phase coil, and a W-phase coil so that the effective conductor portions do not overlap in plan view. When current is applied to the coils of each phase, the plurality of hollow coils are connected so that a thrust force in the arrangement direction of the hollow coils is generated. A part of the coil wire forming the hollow coil has a current flowing along a direction perpendicular to the moving direction of the mover 2. In other words, a part of the coil wire is configured such that a current flows across the magnetic field generated in the stator 1.

[0034] The mold member 41 (coil-containing portion 41b) has a refrigerant injection hole 412 and a refrigerant discharge hole 413. The refrigerant injection hole 412 and the refrigerant discharge hole 413 penetrate both surfaces of the coil-containing portion 41b. The top surfaces of the refrigerant injection hole 412 and the refrigerant discharge hole 413 are respectively. Communicate with the inlet 411 and the discharge port 412. The refrigerant supplied from the inlet 411 is injected into the inside of the movable coil member 4 through the refrigerant injection hole 412. Further, the refrigerant that has flowed through the inside of the movable coil member is discharged to the outside through the refrigerant discharge hole 413 and the discharge port 414.

[0035] The mold member 41 includes a fitting groove portion 421 and a screw hole 423. The fitting groove portion 421 is arranged so as to surround the polyphase coil 6, the refrigerant injection hole 412, and the refrigerant discharge hole 413. A screw hole 423 is formed at the bottom of the fitting groove portion 421. Inside the fitting groove portion 421, a recess 424 is formed to form a refrigerant flow path with the jacket 42.

[0036] The jacket member 42 has a rectangular plate shape. The outer diameter dimension of the jacket member 42 is substantially the same as that of the coil inclusion portion 41b of the mold member 41. The jacket member 42 includes a fitting convex portion 425 and a plurality of holes 422. Since the fitting convex portion 425 has the same shape as the groove shape of the fitting groove portion 421 but with opposite concavities and convexities, when the jacket member 42 is fixed to the mold member 41, the fitting groove portion 421 and the fitting convex portion 425 are fitted together. Thereby, the inside of the fitting convex portion 425 is sealed. Since the recess 424 is formed in the fitting groove portion 421 of the mold member 41, a space 431 is formed inside the fitting groove portion 421 and the fitting convex portion 425, and this space becomes the refrigerant flow path 431.

[0037] A notch 43 reaching the coil inclusion portion 41b is formed in the base portion 41a of the mold member 41, and the temperature sensor 100 is placed on the bottom surface of the notch 43. The notch 43 is formed by cutting a part of the base portion 41a in the longitudinal direction of the mold member 41. The bottom surface of the notch 43 is a flat portion. The temperature sensor 100 includes a main body portion 104, electrodes 102, a metal plate 101, and a fixing hole 103. The main body portion 104 is formed of, for example, resin and includes an electronic circuit such as a hall element inside. The metal plate 101 fixes the main body portion 104 to the temperature measurement location with screws or the like through the fixing hole 103 and efficiently transmits the temperature of the temperature measurement location to the electronic circuit. The electrodes 102 are connected to wires or the like that transmit information of the temperature sensor related to temperature measurement to an external circuit. The temperature sensor 100 is fixed to the bottom of the notch 43 with screws 105 or the like through the fixing hole of the metal plate 103. With such a configuration, the heat generated by the coil is transmitted to the temperature sensor through the resin constituting the mold member 41. In the configuration of FIG. 6 (see FIG. 7), there is a certain interval between the temperature sensor 100, the coil 6, and the refrigerant flow path 431. Since the heat generated by the coil 6 is transmitted to the temperature sensor 100 through the mold resin, the heat transfer is not sufficient, and it may be difficult to measure the temperature accurately.

[0038] Embodiment 1 FIG. 8 is a plan view (partial transparent view) of the movable coil member 5 according to Embodiment 1 of the present invention, and FIG. 9 is a cross-sectional view taken along line C-C of FIG. 8. Explanation of the same parts as in FIGS. 1 to 7 is omitted. The movable coil member 5 includes a mold member 51, a pair of jacket members 42, and a multilayer coil 6. A notch 53 is formed in the base portion 51a of the mold member 51, and the temperature sensor 100 is placed at the bottom of the notch 53. The metal plate 101 of the temperature sensor 100 is fixed to the bottom of the notch 53 by a screw 105. One end of a heat conduction member 55 formed by bending a plate-shaped copper plate into an L shape is fixed to the metal plate 101 and is fixed to the bottom of the notch together with the metal plate 101 by a screw 105. The other end of the heat conduction member 55 is inserted into the refrigerant flow path 431. The temperature change due to the heat generated by the coil 6 is transmitted to the temperature sensor 100 as temperature change information through the refrigerant flowing in the refrigerant flow path 431, or after the heat generated by the coil 6 is transmitted to the heat conduction member 55 through the mold resin, it is transmitted through the metal plate 101. The mold resin between the heat conduction member 55 and the coil 6 is very thin, facilitating heat conduction. Compared with the conventional movable coil member 4 shown in FIGS. 6 and 7, in Embodiment 1, the heat generated by the coil 6 is more easily transmitted to the temperature sensor 100.

[0039] Embodiment 2 FIG. 10 is a plan view (partial transparent view) of the movable coil member 6 according to Embodiment 2 of the present invention, and FIG. 11 is a cross-sectional view taken along line D-D of FIG. 10. The difference from Embodiment 1 is that the heat conduction member is not an L-shaped plate material but a rod shape (cylindrical shape in Embodiment 2). The material is copper. The heat conduction member 75 has a female screw portion corresponding to the screw 105 on one end face, and is fixed to the bottom of the notch 73 formed in the base portion 71a of the movable coil member 7 (mold member 71) by the screw 105 passed through the screw hole 103 of the metal plate 101. A circular hole corresponding to the cylindrical heat conduction member 75 is drilled in the bottom of the notch 73 of the movable coil member 7 (mold member 71), and the heat conduction member 75 is inserted and arranged. Note that the heat conduction member 75 may be arranged by making a hole after forming the mold member 71 in the coil inclusion portion 71b of the mold member 71 of the movable coil member 7, or may be embedded when forming the mold member 71. Since there is a mold resin between the heat conduction member 75 and the coil 6, the circular hole is not a through hole penetrating to the coil 6. The other end face of the heat conduction member 75 can be brought close to the coil 6, and the heat generated by the coil can be quickly transmitted to the temperature sensor 100.

[0040] Embodiment 3 FIG. 12 is a cross-sectional view of the movable coil member 8 according to Embodiment 3 of the present invention. It is a cross-sectional view at the same position as the D-D plane of FIG. 10 according to Embodiment 2. The difference between Embodiment 3 and Embodiment 2 is that the cylindrical hole corresponding to the heat conduction member 75 penetrates and reaches the coil 6. A space is formed between the heat conduction member 75 and the coil 6, and a conductive grease 80 (for example, silicone grease, etc.) is injected into the space. The heat generated from the coil 6 is transmitted to the heat conduction member 75 and the metal plate 101 through the conductive grease, so that the heat generated by the coil can be quickly detected.

[0041] In this specification, the present invention has been described using a linear motor having a movable coil member provided with a plurality of coils, but the present invention can also be applied to a VCM type linear motor using one coil.

[0042] In this specification, the present invention has been described with respect to a moving coil type linear motor, but the present invention is also applicable to a moving magnet type linear motor having a coil as a stator.

[0043] The disclosed embodiments are illustrative and not restrictive. The technical scope of the present invention is indicated by the scope of the claims, and it is intended that meanings equivalent to the scope of the claims and all modifications be included.

Explanation of Reference Numerals

[0044] 1 Stator 2 Mover 3 Dividing unit 4, 5, 7, 8 Moving coil members 6 Coil 10 Moving coil type linear motor 41, 51, 71, 81 Mold members 42 Jacket member 43, 53, 73 Notches 55 Heat conducting member (L-shaped) 75 Heat conducting member (cylindrical) 100 Temperature sensor

Claims

1. A magnetic field generating member having a magnetic gap that generates a magnetic field in a predetermined direction, a coil through which a current flows in a direction crossing the magnetic field, a mold member that encloses the coil and has a rectangular cross-section, and a jacket member fixed to a surface of the mold member on a side facing the magnetic field generating member, the coil member having a space in which a refrigerant can flow formed between the mold member and the jacket member, the coil member having a temperature sensor that measures the temperature of the coil and a heat conducting member that transmits heat generated from the coil to the temperature sensor, the mold member being composed of a coil enclosing portion that encloses the coil and a base portion connected to the coil enclosing portion, the temperature sensor being disposed in a notch formed in the base portion, and a plate-like heat conducting member extending from the temperature sensor into the space in which the refrigerant can flow. A linear motor characterized by this.

2. A magnetic field generating member having a magnetic gap that generates a magnetic field in a predetermined direction, a coil through which a current flows in a direction crossing the magnetic field, a mold member that encloses the coil and has a rectangular cross-section, and a jacket member fixed to a surface of the mold member on a side facing the magnetic field generating member, the coil member having a space in which a refrigerant can flow formed between the mold member and the jacket member, the coil member having a temperature sensor that measures the temperature of the coil and a heat conducting member that transmits heat generated from the coil to the temperature sensor, the mold member being composed of a coil enclosing portion that encloses the coil and a base portion connected to the coil enclosing portion, the temperature sensor being disposed in a notch formed in the base portion, the notch having a hole at the bottom, and a rod-like heat conducting member being disposed in the hole. A linear motor characterized by this.

3. A magnetic field generating member having a magnetic gap in which a magnetic field is generated in a predetermined direction, a coil through which a current flows in a direction crossing the magnetic field, a mold member having a rectangular cross-section and enclosing the coil, and a jacket member fixed to a surface of the mold member facing the magnetic field generating member, the coil member having a space in which a refrigerant can flow between the mold member and the jacket member, the coil member having a temperature sensor for measuring the temperature of the coil and a heat conducting member for transmitting heat generated from the coil to the temperature sensor, the mold member comprising a coil enclosing portion enclosing the coil and a base portion connected to the coil enclosing portion, the temperature sensor being disposed in a notch formed in the base portion and having a through hole portion reaching the coil at the bottom of the notch, a rod-shaped heat conducting member being disposed in the through hole portion, and a heat conducting grease being interposed between the rod-shaped heat conducting member and the coil. A linear motor characterized by that.

4. The linear motor according to any one of claims 1 to 3, characterized in that the heat conducting member is copper.

5. The linear motor according to any one of claims 1 to 4, characterized in that the linear motor is a movable coil type linear motor having a coil as a mover and a magnetic field generating member as a stator.

6. The linear motor according to any one of claims 1 to 5, characterized in that the coil is a coil series in which a plurality of single coils are connected in series.

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