JP2023011178A - linear motor - Google Patents

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

The present invention relates to a linear motor capable of accurately measuring the temperature of armature coils.

2. Description of the Related Art In a semiconductor manufacturing apparatus, a liquid crystal manufacturing apparatus, or an inspection apparatus for semiconductor elements and liquid crystal displays, a biaxial stage apparatus, a so-called XY stage, is used as a conveying apparatus for various parts. The XY stage includes an X stage that moves in a predetermined direction (X direction) with respect to the surface plate, and a Y stage that moves in a direction orthogonal to the X direction (Y direction).
The X stage and Y stage include drive units driven by linear motors or the like. A linear motor includes a magnetic field generating member having a permanent magnet supported by a yoke such that the north pole and the south pole are opposed to each other, and a coil member having a coil crossing the magnetic field.
By applying a current to the coil of the linear motor, the interaction between the magnetic field generated by the permanent magnet and the magnetic field generated by the coil enables relative movement between the magnetic field generating member and the coil member.

The linear motor as described above has a structure in which, for example, the magnetic field generating member is the stator and the coil member is the mover. In such linear motors, it is common practice to increase the current flowing through the coils in order to increase the speed of the conveying device. 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 peripheral members.
As a countermeasure, a jacket member is attached so that a space is formed on both sides of the mold member containing the coil, and a coolant is passed through the space formed by the mold member and the jacket member to cool the coil ( Patent document 1).

Moreover, when cooling a coil, the technique which adjusts the refrigerant|coolants flow amount according to the heat_generation|fever of a coil is proposed (patent document 2).

JP 2017-184492 A JP 2007-325412 A

Patent Document 1 does not disclose a temperature measurement technique, and it is unclear how the temperature is measured.

The technique 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 a method for measuring the temperature of the coil member using the mold member and the jacket member is not disclosed.

Conventionally, in a linear motor similar to the moving-coil linear motor according to Patent Document 1, the inventors provided a notch in a part of a molded member that constitutes a mover, placed a temperature sensor thereon, and formed a coil. The temperature was measured (see Figure 3).
However, the distance between the coil and the temperature sensor is large, and there is a problem that the temperature rise due to the coil cannot be sufficiently detected.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a linear motor including a coil member having a mold member and a jacket member, and capable of accurately measuring the temperature of the coil.

A linear motor according to the present invention includes a magnetic field generating member having a magnetic gap for generating a magnetic field in a predetermined direction, a coil through which a current flows in a direction traversing the magnetic field, a mold member enclosing the coil and having a rectangular cross section, and the a coil member having a jacket member fixed to a surface of the mold member facing the magnetic field generating member, and having a space between the mold member and the jacket member in which a coolant can flow is formed; The coil member has a temperature sensor for measuring the temperature of the coil and a heat conducting member for conducting heat generated from the coil to the temperature sensor.

ADVANTAGE OF THE INVENTION According to this invention, the temperature of the coil of a linear motor can be measured accurately.

In the linear motor according to the present invention, the molded member includes a coil-encapsulating portion that encloses the coil and a base that is connected to the coil-encapsulating portion, and the temperature sensor is arranged in a notch formed in the base. and the plate-like heat conducting member extends from the temperature sensor into a space in which the coolant can flow.

ADVANTAGE OF THE INVENTION According to this invention, the temperature of the coil of a linear motor can be measured accurately.

In the linear motor according to the present invention, the molded member includes a coil-encapsulating portion that encloses the coil and a base that is connected to the coil-encapsulating portion, and the temperature sensor is arranged in a notch formed in the base. In addition, the notch has a hole extending from the notch to the vicinity of the coil, and the rod-shaped heat conducting member is arranged in the hole from the temperature sensor. .

ADVANTAGE OF THE INVENTION According to this invention, the temperature of the coil of a linear motor can be measured accurately.

In the linear motor according to the present invention, the molded member includes a coil-encapsulating portion that encloses the coil and a base that is connected to the coil-encapsulating portion, and the temperature sensor is arranged in a notch formed in the base. and has a hole extending from the notch to the vicinity of the coil, a rod-shaped heat conduction member extending from the temperature sensor is arranged in the hole, and the rod-shaped heat conduction member is positioned between the coil and the temperature sensor. is characterized in that a heat conductive grease is interposed in the

ADVANTAGE OF THE INVENTION According to this invention, the temperature of the coil of a linear motor can be measured accurately.

A linear motor according to the present invention is characterized in that the heat conducting member is made of copper.

ADVANTAGE OF THE INVENTION According to this invention, the temperature of the coil of a linear motor can be measured accurately.

The linear motor of the present invention is characterized by being a moving coil type linear motor having a coil as a mover and a magnetic field generating member as a stator.

ADVANTAGE OF THE INVENTION According to this invention, the temperature of the coil which comprises the needle|mover of a moving-coil linear motor can be measured accurately.

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

ADVANTAGE OF THE INVENTION According to this invention, the temperature of the coil of a linear motor can be measured accurately.

ADVANTAGE OF THE INVENTION According to this invention, the temperature of the coil of a linear motor can be measured accurately.

1 is a plan view of a linear motor according to an embodiment of the invention; FIG. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1; It is a perspective view which shows an example of a coil member. It is an exploded perspective view showing an example of a coil member. It is a perspective view showing an example of a temperature sensor. FIG. 4 is a plan view showing an example of a coil member; FIG. 7 is a cross-sectional view taken along the line BB of FIG. 6; FIG. 4 is a plan view showing the coil member of the present invention; FIG. 9 is a sectional view taken along line CC of FIG. 8; FIG. 4 is a plan view showing an example of the coil member of the present invention; FIG. 11 is a cross-sectional view taken along line DD of FIG. 10; 1 is a cross-sectional view showing an example of a coil member of the present invention; FIG.

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

1 is a plan view of a linear motor according to an embodiment of the present invention, FIG. 2 is a cross-sectional view along the line AA of FIG. 1, FIG. 3 is a perspective view showing an example of a coil member, and FIG. 4 is an example of a coil member. 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 line BB of FIG.
The linear motor of the present invention comprises a stator 1 having a plurality of divided units 3 and a mover 2 having multilayer coils driven within a magnetic gap g formed therein.
This linear motor is constructed by connecting a plurality of divided units 3 along the moving direction of the mover 2 (vertical direction in FIG. 1), and each divided unit 3 has the same structure. However, the lengths do not have to be the same. As shown in FIG. 2, the mover 2 includes a coil member 4 having a multiphase coil, which will be described later, and a holder 5 for supporting the coil member 4. As shown in FIG. The holder 5 is connected to a driven member (not shown).
According to this linear motor, the mover 2 is provided with a magnetic field detection element such as a Hall element 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. can be done.

A divided unit 3 that constitutes the stator 1 includes a non-magnetic frame 31 and a permanent magnet that is a magnetic field generating member 32 . The nonmagnetic frame 31 has a base member 311 and a pair of side members 312 . A base member 311 has a prism shape, and a flat plate-like side member 312 is arranged on the side. The non-magnetic frame 31 has a U-shaped cross section.
A base member 311 and side members 312 that constitute the non-magnetic frame are made of a non-magnetic material such as an aluminum alloy.
A groove 313 extending in the movable direction of the mover 2 is formed in the base member 311 . The groove 313 is provided in the widthwise central portion of the base member 311 . The width and depth of the groove 313 are set so as to accommodate a part of the coil member 4, which will be described later.

The magnetic field generating member 32 includes a yoke 33 , main magnets 34 and auxiliary magnets 35 . The yoke 33 has a flat plate shape and is made of ferromagnetic material such as SS material. A plurality of main magnets 34 are fixed to one surface of the yoke 33 at predetermined intervals along the moving direction of the mover 2 . The magnetization direction of the main magnet 34 is the thickness direction (the direction perpendicular to the moving direction of the mover 2).
The N poles and S poles of the main magnets 34 are alternately arranged 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 perpendicular to the magnetization direction of the main magnet 34 . The auxiliary magnets 35 are arranged so that magnetic poles of the same polarity 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 nonmagnetic frame 31 .
The main magnet 34 and the auxiliary magnet 35 facing each other across the magnetic gap g are arranged so that their different poles face each other, forming a Halbach arrangement. The direction of the magnetic field of the magnetic air gap g is the opposite direction of the magnets.
Known permanent magnets can be used for the main magnet 34 and the auxiliary magnet 35 . An example is a rare earth magnet. R (R is at least one element selected from rare earth elements such as Nd). An RTB based sintered magnet containing T (T is Fe or Fe and Co) and B (boron) as essential components is preferable as the main magnet 34 and the auxiliary magnet 35 .
Here, RTB based sintered magnets are essential materials for reducing the size and weight of linear motors, increasing efficiency and saving energy (improving energy efficiency).

A mover 2 includes a holder 5 and a coil member 4 . A coil member 4 of the mover 2 is driven within a 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) in the mover 2 to detect the magnetic pole position and change 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 coils. The coil member 4 is hereinafter referred to as the movable coil member 4 .

Next, the moving coil member 4 will be described in detail. 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. As shown in FIG. The moving coil member 4 includes a mold member 41 , a pair of jacket members 42 and a multilayer coil 6 . The movable coil member 4 has a rectangular plate shape.

The mold member 41 has a T-shape in cross section and is composed of a coil enclosing portion 41b enclosing the multilayer coil 6 and a base portion 41a connected to the coil enclosing portion. Jacket members 42 are fixed to both side surfaces of the coil enclosing portion 41b. there is Mold member 41 is formed by molding a coil with resin.
A coolant inlet 411 and a coolant outlet 414 are provided in the mold member 41 (base portion 41a). The inlet 411 and the outlet 414 extend vertically.
The molding member 41 has high rigidity, electrical insulation, and resistance to coolant, and is made of, for example, glass epoxy.

If the multilayer coil 6 is a three-layer coil, six flat air-core coils are arranged so that the effective conductor portions of the U-phase coil, V-phase coil, and W-phase coil do not overlap in plan view.
The plurality of air-core coils are connected so that thrust is generated in the arrangement direction of the air-core coils when the coils of each phase are energized. Some of the coil wires that form the air-core coil carry current along the direction perpendicular to the moving direction of the mover 2 . In other words, part of the coil wire is configured so that current flows across the magnetic field generated in the stator 1 .

The molded member 41 (coil enclosing portion 41 b ) has a coolant injection hole 412 and a coolant discharge hole 413 . The refrigerant injection hole 412 and the refrigerant discharge hole 413 penetrate both sides of the coil inner portion 41b. The top surfaces of the coolant injection hole 412 and the coolant discharge hole 413 are respectively. It communicates with the inlet 411 and the outlet 412 . The refrigerant supplied from the injection port 411 is injected into the movable coil member 4 through the refrigerant injection hole 412 . Further, the coolant that has flowed inside the moving coil member is discharged to the outside through the coolant discharge hole 413 and the discharge port 414 .

Mold member 41 includes fitting groove 421 and screw hole 423 . The fitting groove portion 421 is arranged so as to surround the multiphase coil 6 , the coolant injection hole 412 and the coolant discharge hole 413 . A screw hole 423 is formed in the bottom of the fitting groove portion 421 . A concave portion 424 is formed inside the fitting groove portion 421 to form a coolant flow path with the jacket 42 .

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 enclosing portion 41b of the molded member 41. As shown in FIG. The jacket member 42 includes a fitting protrusion 425 and a plurality of holes 422 . Since the fitting convex portion 425 has the same concave and convex shape as the groove shape of the fitting groove portion 421, the fitting groove portion 421 and the fitting convex portion 425 are formed by fixing the jacket member 42 to the mold member 41. Mate. Thereby, the inside of the fitting protrusion 425 is sealed.
Since the concave portion 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 coolant flow path 431 .

A notch 43 reaching the coil enclosing portion 41b is formed in the base portion 41a of the molded member 41, and the temperature sensor 100 is mounted on the bottom surface of the notch 43. As shown in FIG.
The notch 43 is formed by cutting a part of the base 41 a in the longitudinal direction of the mold member 41 . The bottom surface of the notch 43 is a flat portion.
The temperature sensor 100 consists of a main body 104 , an electrode 102 , a metal plate 101 and a fixing hole 103 . The main body 104 is made of resin, for example, and contains an electronic circuit including a hall element and the like. The metal plate 101 fixes the main body 104 to the place where the temperature is to be measured by screws or the like through the fixing holes 103, and efficiently transmits the temperature of the place to be measured to the electronic circuit.
The electrode 102 is connected to an electric wire or the like for transmitting temperature sensor information related to temperature measurement to an external circuit. The temperature sensor 100 is fixed to the bottom of the notch 43 by a fixing hole in the metal plate 103 with a screw 105 or the like.
With such a configuration, the heat generated by the coil is transferred to the temperature sensor via the resin forming the mold member 41 .
In the configuration of FIG. 6 (see FIG. 7), there is a constant gap between the temperature sensor 100 and the coil 6 and the coolant flow path 431, so that the heat generated by the coil 6 is transmitted to the temperature sensor 100 via the mold resin. As a result, heat transfer is not sufficient, and accurate temperature measurement may be difficult.

Embodiment 1
8 is a plan view (partially see-through view) of the moving coil member 5 according to Embodiment 1 of the present invention, and FIG. 9 is a sectional view taken along line CC of FIG. Description of the same parts as in FIGS. 1 to 7 will be omitted.
The moving 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 mounted on the bottom portion of the notch 53. As shown in FIG. A metal plate 101 of the temperature sensor 100 is fixed to the bottom of the notch 53 with screws 105 . One end of a heat conducting member 55 formed by bending a plate-like copper plate into an L shape is fixed to the metal plate 101 , and is fixed together with the metal plate 101 to the bottom of the notch with a screw 105 . The other end of heat conducting member 55 is inserted into coolant channel 431 . The change in temperature due to the heat generated by the coil 6 is transmitted to the heat conducting member 55 via the coolant flowing in the coolant flow path 431 or the heat generated by the coil 6 via the mold resin. Information on temperature change is transmitted to the temperature sensor 100 via the metal plate 101 .
The molding resin between the heat conducting member 55 and the coil 6 is very thin, and heat is easily conducted.
In Embodiment 1, the heat generated by the coil 6 is more easily transferred to the temperature sensor 100 than the conventional moving coil member 4 shown in FIGS.

Embodiment 2
10 is a plan view (partially see-through view) of the moving coil member 6 according to Embodiment 2 of the present invention, and FIG. 11 is a cross-sectional view taken along line DD of FIG.
The difference from the first embodiment is that the heat-conducting member is not an L-shaped plate material but a rod-like one (columnar in the second embodiment). The material is copper.
The heat conducting member 75 has a female screw portion corresponding to the screw 105 on one end surface, and a notch formed in the base portion 71a of the movable coil member 7 (molded member 71) by the screw 105 passed through the screw hole 103 of the metal plate 101. It is fixed to the bottom of 73.
A circular hole corresponding to the cylindrical heat conducting member 75 is bored in the bottom of the notch 73 of the movable coil member 7 (molding member 71), and the heat conducting member 75 is inserted and arranged.
The heat conducting member 75 may be placed in the coil encapsulating portion 71b of the mold member 71 of the movable coil member 7 by opening a hole after the mold member 71 is formed, or may be embedded when the mold member 71 is formed. Also good.
Since there is mold resin between the heat conducting 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-conducting member 75 can be brought close to the coil 6 , so that the heat generated by the coil can be quickly transferred to the temperature sensor 100 .

Embodiment 3
FIG. 12 is a sectional view of the moving coil member 8 according to Embodiment 3 of the present invention. 11 is a cross-sectional view of the same position as the DD plane of FIG. 10 according to Embodiment 2. FIG.
The third embodiment differs from the second embodiment in that a cylindrical hole corresponding to the heat conducting member 75 penetrates and reaches the coil 6 .
A space is formed between the heat conducting member 75 and the coil 6, and conductive grease 80 (for example, silicon grease) is injected into the space.
Since the heat generated from the coil 6 is transmitted to the heat conducting member 75 and the metal plate 101 via the conductive grease, the heat generated by the coil can be quickly detected.

In this specification, the present invention has been described using a linear motor having a moving coil member with a plurality of coils, but the present invention can also be applied to a VCM type linear motor using a single coil.

In this specification, the present invention has been described with respect to a moving coil type linear motor, but the present invention can also be applied to a moving magnet type linear motor using a coil as a stator.

The disclosed embodiments are illustrative and not restrictive. The technical scope of the present invention is indicated by the scope of claims, and is intended to include meanings equivalent to the scope of claims and all modifications.

1 Stator 2 Mover 3 Divided Units 4, 5, 7, 8 Moving Coil Member 6 Coil 10 Moving Coil Type Linear Motor 41, 51, 71, 81 Mold Member 42 Jacket Members 43, 53, 73 Notch 55 Heat Transfer Member (L-shaped)
75 heat-conducting member (cylindrical)
100 temperature sensor

Claims (7)

A magnetic field generating member having a magnetic gap for generating a magnetic field in a predetermined direction, a coil through which a current flows in a direction transverse to the magnetic field, a mold member enclosing the coil and having a rectangular cross section, and the magnetic field generating member of the mold member a coil member having a jacket member fixed to the surface on the opposite side, wherein a space is formed between the mold member and the jacket member so that a coolant can flow; A linear motor, comprising: a temperature sensor for measuring the temperature of the coil; and a heat conducting member for transferring heat generated from the coil to the temperature sensor. The molded member includes a coil encapsulating portion that encloses the coil and a base that is connected to the coil encapsulating portion. 2. The linear motor according to claim 1, wherein said plate-like heat conducting member extends from said temperature sensor in a space. The molded member includes a coil encapsulating portion enclosing the coil and a base portion connected to the coil encapsulating portion. The temperature sensor is arranged in a notch formed in the base portion, 2. The linear motor according to claim 1, further comprising a hole reaching the vicinity of said coil, and said rod-shaped heat conducting member extending from said temperature sensor is arranged in said hole. The molded member includes a coil encapsulating portion enclosing the coil and a base portion connected to the coil encapsulating portion. The temperature sensor is arranged in a notch formed in the base portion, It has a hole that reaches near the coil, a rod-shaped heat-conducting member is arranged in the hole from the temperature sensor, and heat-conducting grease is interposed between the rod-shaped heat-conducting member and the coil. 2. A linear motor according to claim 1, characterized in that: 5. A linear motor according to claim 1, wherein said heat conducting member is made of copper. 6. The linear motor according to any one of claims 1 to 5, wherein the linear motor is a moving coil type linear motor having a coil as a mover and a magnetic field generating member as a stator. 7. A linear motor according to any one of claims 1 to 6, wherein said coil is a coil array in which a plurality of one coils are connected in series.

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