WO2015141591A1

WO2015141591A1 - Linear motor

Info

Publication number: WO2015141591A1
Application number: PCT/JP2015/057523
Authority: WO
Inventors: 正喜武富; 栗山　義彦; 正宏増澤; 幸英赤木
Original assignee: 日立金属株式会社
Priority date: 2014-03-19
Filing date: 2015-03-13
Publication date: 2015-09-24
Also published as: JPWO2015141591A1

Abstract

A linear motor is provided in which, even when the total length of the linear motor is large, the movable element is smaller and lighter without the use of additional magnets, and which further has a cooling mechanism. This linear motor is provided with a stator (2) and a movable element (1), and the stator (2) has two plate sections (an upper plate section (21) and a lower plate section (22)) which are magnetically coupled and opposite of each other, the movement region of the movable element (1) being therebetween. On each of the facing surfaces of said two plate sections (21, 22), multiple teeth (21a, 22a) are arranged in a row in the movement direction of the movable element (1) such that the teeth (21a) on one plate section (21) and the teeth (22a) on the other plate section (22) are staggered. The movable element (1) is configured such that multiple magnets (1c, 1d) and multiple yokes (1b) are arranged alternately within a coil (1a) along the movement direction, the magnets (1c, 1d) that are adjacent with a yoke (1b) interposed therebetween are magnetized in opposite directions to each other, and further, and the movable element (1) comprises a cooling unit (a cooling pipe (11)) which cools the coil (1a).

Description

Linear motor

The present invention relates to a linear motor.

For example, in the field of manufacturing semiconductor manufacturing devices and liquid crystal display devices, there is a feeding device that can linearly move an object to be processed such as a large-area substrate at a high speed and accurately position the object at an appropriate moving position. is necessary. This type of feeding device is generally realized by converting the rotational motion of a motor as a drive source into a linear motion by a motion conversion mechanism such as a ball screw mechanism, but since a motion conversion mechanism is interposed, There is a limit to increasing the moving speed. There is also a problem that positioning accuracy is insufficient due to the presence of mechanical errors in the motion conversion mechanism.

In order to cope with this problem, in recent years, a feeding device using a linear motor that can directly extract linear motion output as a driving source has been used. The linear motor includes a linear stator and a mover that moves along the stator. In the above-described feeding device, a moving coil type linear motor (a moving coil type linear motor) in which a large number of plate-like permanent magnets are arranged in parallel at regular intervals to constitute a stator, and an armature having magnetic pole teeth and energizing coils is used as a mover. For example, Patent Document 1) is used.

In the moving coil type linear motor, since the magnet is arranged on the stator, the amount of magnet to be used increases as the total length of the linear motor becomes longer (the moving distance of the mover becomes longer). In recent years, with the increase in the price of rare earths, an increase in the amount of magnets used has caused an increase in cost.

Also, the linear motor generates heat when the coil used for the mover is energized. When the electric resistance of the coil increases due to heat generation, the thrust decreases. In order to suppress this reduction in thrust, the linear motor needs to include a coil cooling mechanism. In response to such a problem, a cooling mechanism for a moving coil type linear motor has been proposed in which the entire coil is covered with a jacket and a refrigerant flows inside the jacket (Patent Document 2).

JP-A-3-139160 JP 2009-219206 A

In a linear motor, the magnetic force acting between the stator and the mover separates not only the thrust force that moves the mover relative to the stator, but also the attracting force in the direction in which the stator and the mover are brought close to each other, and pulling them apart from each other. A repulsive force in the direction is generated. Stress is generated in the stator and the mover due to the suction force and the repulsive force. For this reason, when a jacket that allows a refrigerant to pass therethrough is attached to the coil for cooling, the jacket needs to be rigid enough to withstand the generated stress. On the other hand, in a linear motor of a type in which the coil is movable, the loss of thrust can be suppressed by making the mover lightweight. Therefore, the jacket attached to the mover also needs to be lightweight. Therefore, when molding the jacket with a resin or the like in order to reduce the weight of the jacket, it is necessary to reinforce the resin or the like with glass fibers in order to ensure the rigidity of the entire jacket, leading to an increase in cost.
Furthermore, a structure for reinforcing the jacket (referred to as a core part in Patent Document 2) is required in the hollow part of the air-core coil, and the jacket structure is complicated.

The present invention has been made in view of the circumstances as described above, and even if the total length of the linear motor is long, the amount of use of the magnet does not increase, and the miniaturization and weight reduction of the mover can be realized, and the heat generation of the mover. Can be suppressed. Also, it has a structure that can be cooled with a simple pipe-like structure without a resin molding process such as a jacket when cooling the mover, and even when cooling with a resin molded jacket, glass fiber etc. An object of the present invention is to provide a linear motor equipped with a cooling mechanism that does not necessarily require a fiber reinforced plastic containing.

The linear motor according to the present invention is a linear motor including a stator and a mover, and the stator has two opposing plate-like portions that are magnetically coupled with a moving range of the mover in between. In each of the opposing surfaces of the two plate-like portions, the plurality of tooth portions are movable so that the tooth portions of one plate-like portion and the tooth portions of the other plate-like portion are staggered. A plurality of permanent magnets and a plurality of yokes are alternately arranged in the coil along the movement direction, and the mover is arranged adjacent to each other via the yoke. The magnets are magnetized in directions facing each other, and further include a cooling unit that cools the coil.

In the present invention, the mover has a plurality of permanent magnets and a plurality of yokes alternately arranged in the coil along the moving direction of the mover. Since the permanent magnet is disposed only on the mover, the amount of permanent magnet to be used does not increase even when the total length of the linear motor is increased. Moreover, it has a cooling unit for cooling the coil, and it is possible to remove the heat generated by the coil.

The linear motor according to the present invention is characterized in that the cooling part has a cooling pipe, and the cooling pipe is arranged on the outer surface of the coil.

In the present invention, the cooling part has a cooling pipe, and the cooling pipe is disposed on the outer surface of the coil, so that the heat generation of the coil can be removed with a simple structure.

In the linear motor according to the present invention, the length of the coil and the cooling pipe in the direction perpendicular to the two plate-like portions is the length of the permanent magnet and the yoke in the direction perpendicular to the two plate-like portions. It is characterized by the following.

In the present invention, since the yoke and the permanent magnet protrude from the coil and the cooling pipe or are flush with each other, the gap between the yoke and the tooth portion can be reduced, so that the thrust can be increased.

The linear motor according to the present invention is characterized in that the cooling part is a cooling jacket containing the coil.

In the present invention, since the cooling portion is a cooling jacket that encloses the coil, the coil can be efficiently cooled from the entire outer surface of the coil.

In the linear motor according to the present invention, the length of the cooling jacket in the direction perpendicular to the two plate-like portions is equal to or less than the length of the permanent magnet and the yoke in the direction perpendicular to the two plate-like portions. It is characterized by that.

In the present invention, since the yoke and the permanent magnet protrude from the cooling jacket or are flush with each other, the gap with the tooth portion can be reduced, so that the thrust can be increased.

The linear motor according to the present invention is characterized in that the mover has two permanent magnets and three yokes.

In the present invention, since the mover has a minimum configuration having two permanent magnets and three yokes, the dimension of the mover in the moving direction can be further reduced. In other words, the pitch of the teeth on the stator side can be relatively increased. Further, since permanent magnets are not used for the stator, the amount of permanent magnets used does not increase even when the total length of the linear motor is long.

The linear motor according to the present invention is characterized in that a yoke sandwiched between the two permanent magnets is longer in the moving direction than the other two yokes.

In the present invention, the yoke sandwiched between the two permanent magnets is longer in the moving direction than the other two yokes that are in contact with only one permanent magnet. The length in the direction of movement, that is, the length of the portion facing the teeth, is determined according to the amount of magnetic flux exchanged with the permanent magnet, so even if the amount of current flowing through the coil increases, the yoke is less likely to cause magnetic saturation. As a result, thrust reduction can be suppressed.

The linear motor according to the present invention is characterized in that the length of the yoke sandwiched between the two permanent magnets is twice as long as the other two yokes.

In the present invention, the length in the moving direction of the yoke sandwiched between two permanent magnets is twice as long as the other two yokes that are optimal for the amount of magnetic flux flowing. While reducing the length in the moving direction, it is possible to relax the magnetic saturation of the yoke and obtain a large thrust linear motor.

The linear motor according to the present invention is a linear motor including a stator and a mover, and the stator has two opposing plate-like portions that are magnetically coupled with a moving range of the mover in between. In each of the opposing surfaces of the two plate-like portions, the plurality of tooth portions are movable so that the tooth portions of one plate-like portion and the tooth portions of the other plate-like portion are staggered. The mover has a cooling unit and a plurality of unit movers, and each unit mover has three coils arranged along the move direction, A plurality of permanent magnets and a plurality of yokes are alternately arranged in the coil along the moving direction, and the permanent magnets adjacent via the yoke are magnetized in directions facing each other. To do.

In the linear motor according to the present invention, the cooling section is provided corresponding to each unit mover, and each cooling section has a hollow shape including the coils, and the plurality of permanent magnets and the plurality of yokes. It is characterized by surrounding.

In the present invention, since the cooling unit contains the coil, the coil can be efficiently cooled.

The linear motor according to the present invention is characterized in that the cooling portion is hollow, includes all the coils of the mover, and surrounds the plurality of permanent magnets and the plurality of yokes.

In the present invention, since the cooling unit includes all the coils, the coils can be efficiently cooled.

In the present invention, since the mover is configured to include a plurality of permanent magnets and a plurality of yokes, it is possible to reduce the size of the mover in the moving direction, and no magnet is used for the stator. Therefore, even when the total length of the linear motor is long, there is an effect that the amount of magnets used does not increase.
Furthermore, by providing the coil cooling unit, the coil is efficiently cooled, and the effect of suppressing the reduction in thrust is achieved.

1 is a partially broken perspective view showing an example of a schematic configuration of a linear motor according to Embodiment 1. FIG. 3 is an explanatory diagram illustrating a configuration example of a mover of the linear motor according to Embodiment 1. FIG. 3 is an explanatory diagram illustrating a configuration example of a mover of the linear motor according to Embodiment 1. FIG. 1 is a cross-sectional view illustrating a schematic configuration of a linear motor according to a first embodiment. 1 is a side view illustrating a schematic configuration of a linear motor according to a first embodiment. FIG. 4 is a diagram for explaining the principle of thrust generation of the linear motor according to the first embodiment. FIG. 4 is a diagram for explaining the principle of thrust generation of the linear motor according to the first embodiment. FIG. 4 is a diagram for explaining the principle of thrust generation of the linear motor according to the first embodiment. 6 is an explanatory diagram illustrating a configuration example of a mover of a linear motor according to Embodiment 2. FIG. 6 is an explanatory diagram illustrating a configuration example of a mover of a linear motor according to Embodiment 2. FIG. It is explanatory drawing which shows the structural example of the needle | mover attached to the needle | mover base. 10 is an explanatory diagram illustrating a configuration example of a mover of a linear motor according to Embodiment 3. FIG. 10 is an explanatory diagram illustrating a configuration example of a mover of a linear motor according to Embodiment 3. FIG. FIG. 10 is an explanatory diagram illustrating a configuration example of a mover of a linear motor according to a fourth embodiment. FIG. 10 is an explanatory diagram illustrating a configuration example of a mover of a linear motor according to a fourth embodiment. In Embodiment 4, it is explanatory drawing which shows the structural example of the needle | mover attached to the needle | mover base. FIG. 10 is an explanatory diagram illustrating a configuration example of a mover of a linear motor according to a fifth embodiment. FIG. 10 is an explanatory diagram illustrating a configuration example of a mover of a linear motor according to a fifth embodiment. In Embodiment 5, it is explanatory drawing which shows the structural example of the needle | mover attached to the needle | mover base. FIG. 10 is a plan view illustrating a configuration example of a mover of a linear motor according to a sixth embodiment. It is explanatory drawing about the magnetic saturation of the yoke of a needle | mover. It is explanatory drawing about the magnetic saturation of the yoke of a needle | mover. FIG. 10 is an explanatory diagram illustrating a configuration example of a mover of a linear motor according to a seventh embodiment. FIG. 10 is an explanatory diagram illustrating a configuration example of a mover of a linear motor according to a seventh embodiment. FIG. 10 is an explanatory diagram illustrating a configuration example of a mover of a linear motor according to an eighth embodiment. FIG. 10 is an explanatory diagram illustrating a configuration example of a mover of a linear motor according to an eighth embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1
FIG. 1 is a partially broken perspective view showing an example of a schematic configuration of the linear motor according to the first embodiment. 2A and 2B are explanatory diagrams illustrating a configuration example of the mover 1 of the linear motor according to the first embodiment. 2A is a plan view of the mover 1, and FIG. 2B is a cross-sectional view taken along the line II-II of FIG. 2A. FIG. 3 is a cross-sectional view showing a schematic configuration of the linear motor according to the first embodiment. FIG. 4 is a side view showing a schematic configuration of the linear motor according to the first embodiment.

The linear motor according to the present embodiment includes a mover 1 and a stator 2. The mover 1 includes three yokes 1b, two

permanent magnets

1c and 1d, a coil 1a surrounding them, and a cooling pipe 11 surrounding the coil 1a. The yoke 1b, the permanent magnet 1c, and the permanent magnet 1d are substantially the same shape and have a substantially rectangular parallelepiped shape. As shown in FIG. 1 or 2, the yoke 1b, the permanent magnet 1c, the yoke 1b, the permanent magnet 1d, the yoke 1b, and the yoke 1b, the permanent magnet 1c, or the permanent magnet 1d are alternately arranged in the connecting direction. The yoke 1b, the permanent magnet 1c, and the permanent magnet 1d are aligned and connected so that the short sides are aligned and the long sides are in contact, and the coil 1a is wound around the periphery. The cooling pipe 11 has a substantially rectangular frame shape and is provided in contact with the outer surface of the coil 1a. The yoke 1b is disposed so as to sandwich the permanent magnet 1c and the permanent magnet 1d. The white arrows shown in the

permanent magnets

1c and 1d in FIGS. 2 and 4 indicate the magnetization directions of the

permanent magnets

1c and 1d. The end point of the white arrow indicates the N pole, and the start point indicates the S pole. The permanent magnet 1c and the permanent magnet 1d are magnetized along the coupling direction, and the magnetization directions are opposed to each other. The configuration in which the mover 1 includes three yokes 1b, one permanent magnet 1c, and one permanent magnet 1d as in the present embodiment is the minimum configuration of the mover 1.

The cooling pipe 11 surrounding the outer surface of the coil 1a is for cooling the coil 1a. The cooling pipe 11 includes a liquid supply port 11a through which a refrigerant is sent by a pump provided in a cooling circuit (not shown), and a liquid discharge port 11b that discharges the refrigerant to the cooling circuit. In the cooling pipe 11, for example, a perfluoropolyether refrigerant cooled by a heat exchanger (not shown) flows. The refrigerant supplied from the liquid supply port 11a contacts the outer surface of the coil 1a, flows in the cooling pipe 11 surrounding the coil 1a, and is discharged from the liquid discharge port 11b. Thereby, it becomes possible to cool the whole coil 1a efficiently. The cooling pipe 11 is preferably made of a nonmagnetic metal such as stainless steel, for example.
Further, it is possible to efficiently cool only the coil that generates heat when energized.
Since it is a pipe, the structure for allowing the refrigerant to pass therethrough is simple, and the weight of the cooling unit can be reduced. Moreover, it is not limited to nonmagnetic metals, and may be composed of fiber reinforced plastics or ceramics containing glass fibers or carbon fibers, and may be appropriately set to withstand the acceleration / deceleration speed of the mover 1 or the pressure of the refrigerant. Depending on the case, hard plastic may be used. The refrigerant may be a fluorine-based inert liquid other than perfluoropolyether or a natural refrigerant (pure water). The vertical lengths of the permanent magnet 1c, the permanent magnet 1d, and the yoke 1b (the vertical lengths of the two plate-like portions) are longer than the vertical lengths of the coil 1a and the cooling pipe 11. These lengths may be the same.

As shown in FIG. 3, the stator 2 has a substantially U-shaped cross section (U shape). The stator 2 connects two plate-like portions (upper plate portion 21 and lower plate portion 22) that are parallel to each other with a predetermined distance therebetween, and connects the upper plate portion 21 and the lower plate portion 22. A side plate portion 23 having a plate shape is included. The upper plate portion 21 and the lower plate portion 22 of the stator 2 are magnetically coupled by the side plate portion 23. The upper plate portion 21 includes a plurality of tooth portions 21 a on one surface facing the lower plate portion 22. A plurality of tooth portions 21a are juxtaposed at predetermined intervals. Similarly, the lower plate portion 22 includes a plurality of tooth portions 22 a on the surface facing the upper plate portion 21. A plurality of tooth portions 22a are juxtaposed at predetermined intervals. The tooth part 21a and the tooth part 22a have a substantially rectangular parallelepiped shape. The stator 2 is formed by bending a flat soft magnetic metal, for example, a rolled steel material. In addition to forming the stator 2 by bending, a flat rolled steel material may be joined and fixed by welding, screwing, or the like. The upper plate portion 21, the lower plate portion 22, and the side plate portion 23 may be formed by laminating soft magnetic metal plates such as steel plates. The tooth portion 21a and the tooth portion 22a are each formed in a rectangular parallelepiped shape by laminating soft magnetic metal plates such as steel plates. The tooth portions 21a and the tooth portions 22a formed in a rectangular parallelepiped shape are joined and fixed to the upper plate portion 21 and the lower plate portion 22 by welding or screwing, respectively.

Further, a groove may be provided on one surface of the magnetic steel plate formed in a substantially U shape at a predetermined interval by digging or the like, and the formed land portion may be used as the tooth portion 21a and the tooth portion 22a. If it does in this way, it will become possible to reduce the number of parts of the stator 2 compared with the case where a tooth part is fixed by welding etc. by joining or screwing. Furthermore, slits may be formed in the plate-like member at a predetermined interval, and portions sandwiched between the two slits may be used as the tooth portion 21a and the tooth portion 22a. The plate-like member may be formed in a comb shape, and the comb teeth may be used as the tooth portion 21a and the tooth portion 22a. It is not an essential requirement of the stator 2 to be installed in the direction shown in FIG. It can be used in any orientation that can be installed. It may be placed upside down, placed in a U shape, or placed in a U shape upside down. Between the upper plate portion 21 and the lower plate portion 22 of the stator 2 configured as described above, the mover 1 moves in the direction in which the tooth portions 21a and the tooth portions 22a are arranged.

As shown in FIGS. 3 and 4, it is desirable that the tooth portion 21a and the tooth portion 22a have the same shape and the same dimensions. The ratio between the length L1 of the tooth portion 21a (tooth portion 22a) along the moving direction of the mover 1 and the distance L2 between the two tooth portions 21a (tooth portion 22a) is 1: 1. That is, the width L1 in the juxtaposed direction of the tooth portion 21a (tooth portion 22a) is the same length as the juxtaposed interval L2 of the tooth portion 21a (22a).

The width of the mover 1 in the moving direction excluding the coil 1a and the cooling pipe 11 is narrower than the width (L1 + L2) of the width L1 of the tooth portion 21a (22a) and the interval L2 of the two tooth portions 21a (22a). It is. In FIG. 3, the length of the tooth portion 21a and the tooth portion 22a in the left-right direction in the drawing is slightly longer than the yoke 1b and the

permanent magnets

1c and 1d. In this case, the air gap is virtually shortened by the fringing magnetic flux, and the magnetic flux from the permanent magnet 1c and the permanent magnet 1d of the mover 1 can be efficiently passed through the stator 2. Further, the lengths of the tooth portions 21a and the tooth portions 22a may be the same as the lengths of the yoke 1b, the permanent magnet 1c, and the permanent magnet 1d.

The tooth part 21a and the tooth part 22a are respectively arranged on the opposing surface side of the upper plate part 21 and the lower plate part 22 facing the stator 2 at equal intervals (L2). The longitudinal direction of the tooth part 21a and the tooth part 22a is arranged substantially perpendicular to the moving direction of the mover 1. Further, the tooth portions 21a and the tooth portions 22a are arranged in a staggered manner (in a zigzag manner) along the moving direction of the mover 1 so that the central portions in the moving direction of the mover 1 on the surfaces facing each other do not overlap. . In addition, if the whole surface of the tooth part 21a and the tooth part 22a facing each other overlaps, no thrust is generated in the mover 1.

As shown in FIG. 4, one surface of the mover 1 faces the tooth portion 21a, and the other surface faces the tooth portion 22a. One of the yokes 1b arranged before and after the moving direction is opposed to the tooth portion 21a, and the other is opposed to the tooth portion 22a. The central yoke 1b faces both the

tooth portions

21a and 22a. One tooth portion 21a and one tooth portion 22a are provided for each magnetic period. The tooth portion 21a and the tooth portion 22a are provided at different positions (positions shifted by 1/2 magnetic cycle) at an electrical angle of 180 degrees.
Length in the direction perpendicular to the moving direction of the mover 1 of the yoke 1b and the permanent magnet 1c and permanent magnet 1d (in FIG. 2A, the direction perpendicular to the paper surface, in FIG. 3, the length in the vertical direction of the paper surface: the upper plate portions facing each other 21 and the length of the plate surface of the lower plate portion 22 in the normal direction) are preferably substantially the same. Here, when the yoke 1b is longer than the permanent magnet 1c and the permanent magnet 1d, the magnetic flux of the yoke 1b in the portion protruding from the permanent magnet 1c and the permanent magnet 1d is applied to the plate surface of the upper plate portion 21 or the lower plate portion 22. It does not flow in the normal direction but leaks in a direction parallel to the plate surface. As a result, the amount of magnetic flux flowing from the yoke 1b to the

tooth portion

21a or 22a of the stator 2 is reduced, and the thrust is reduced.
Further, when the length of the permanent magnet 1c and the permanent magnet 1d in the direction perpendicular to the moving direction of the mover 1 is longer than that of the yoke 1b, the plate surface of the upper plate portion 21 or the lower plate portion 22 of the magnetic flux contributing to thrust. Since it becomes difficult to secure a vertical component with respect to, thrust loss occurs. As will be described later, since the thrust of the present invention depends on the amount of magnetic flux flowing between the yoke 1b and the tooth portion 21a and between the yoke 1b and the tooth portion 22a, the permanent magnet 1c and the permanent magnet 1d are projected. The distance between the tooth portion 21a and the yoke 1b and the distance between the tooth portion 22a and the yoke 1b are increased, and the thrust is reduced.
Further, when either the yoke 1b or the permanent magnet 1c or the permanent magnet 1d protrudes, the heat conduction of the protruding portion is deteriorated, and the cooling efficiency is lowered.
Here, “substantially the same” means that the dimensions are the same in designing the structure. In addition, since it includes a processing error due to processing equipment, it is described as substantially the same after including a tolerance in design dimension setting.

5, 6 and 7 are diagrams for explaining the principle of thrust generation of the linear motor according to the first embodiment. For convenience of explanation, the portion along the moving direction of the coil 1a and the cooling pipe 11 of the mover 1 is omitted, and only the cross section of the portion orthogonal to the moving direction is shown. An alternating current is passed through the coil 1a of the mover 1. 5 and 6, black circles indicate energization from the back of the paper to the front, and crosses indicate energization from the front to the back of the paper. When the coil 1a is energized (showing the direction of the current at a certain time when an alternating current is passed), a magnetic flux as shown by the dotted line in FIG. 5 is generated.

When the number of yokes 1b provided in the mover 1 is 3, as shown in FIG. 5, the magnetic flux flowing from the tooth portion 21a flows into the yokes 1b at both ends, passes through the

permanent magnets

1c and 1d, and the yoke 1b in the central portion. Gathered to the tooth portion 22a. If it does in this way, the space | interval (L3) of the moving direction center part of the yoke 1b of both ends can be made smaller than the space | interval (pitch) (L1 + L2) of the parallel direction direction center part of the tooth part 21a arranged in parallel. That is, the length of the mover 1 in the moving direction can be reduced.
In the case of the present invention, one movable element 1 is driven in a single phase, and the pitch of the tooth portions per phase can be relatively increased.
In the three-phase linear motor, in order to suppress the fluctuation range of the three-phase combined thrust that varies depending on the position of the mover 1, the thrust waveform per single phase needs to be substantially a sine wave. It is also necessary to ensure thrust. As one of the means, it is common to reduce the pitch by providing a plurality of magnetic poles in each phase, which simplifies the structure of the mover and makes the stator 2 and the mover 1 smaller and lighter. However, when the pitch is narrowed, the drive frequency is increased and the iron loss of the linear motor itself increases, but the tooth pitch is increased by the configuration of the first embodiment. Can do.

On the other hand, when the number of the yokes 1b included in the mover 1 is four or more, each yoke 1b with respect to the interval (pitch) (L1 + L2) of the central portion in the moving direction of the tooth portions 21a arranged side by side. It is necessary to reduce the distance between the central portions in the moving direction to ½. If it compares in FIG. 5, it is necessary to make it L1 + L2 = L3 / 2 + L3 / 2 = L3, Therefore It becomes difficult to make the length of the moving direction of the needle | mover 1 small. That is, when there are four or more yokes 1b, there are the following problems. When L1 + L2> L3, the interval between adjacent yokes 1b is reduced. Since the field directions of the permanent magnet 1c and the permanent magnet 1d of the adjacent yoke 1b through the permanent magnet 1c and the permanent magnet 1d are opposite to each other, they are attracted and repelled with the one tooth portion 21a (22a). Is performed at a short distance, and the thrust generated between the mover 1 and the stator 2 is reduced.
However, even in this configuration, the configuration of the present invention in which the plurality of yokes 1b, the plurality of permanent magnets 1c, and the permanent magnet 1d are surrounded by the coil 1a does not increase the number of permanent magnets even when the linear motor becomes long.

Next, the principle of thrust generation of the linear motor according to the first embodiment will be described with reference to FIGS. As described above, the flow of magnetic flux as indicated by the dotted line is generated in the mover 1 in FIG. That is, the magnetic flux generated in the left and right yokes 1b passes through the permanent magnet 1c or the permanent magnet 1d and flows into the tooth portion 22a from the central yoke 1b. The magnetic flux flowing into the tooth portion 22a passes through the lower plate portion 22, the side plate portion 23, and the upper plate portion 21, flows into the left and right yokes 1b from the tooth portion 21a, and the above-described magnetic flux loop is generated. By the magnetic flux loop, the tooth portion 21a is excited to the N pole and the tooth portion 22a is excited to the S pole.

Next, generation of magnetic poles and generation of thrust by a permanent magnet will be described with reference to FIG. As shown in FIG. 6, when the permanent magnet 1c and the permanent magnet 1d are arranged so that the magnetization direction is opposed to the yoke 1b, each yoke 1b has a single pole. The central yoke 1b is excited to the N pole, and the left and right yokes 1b are excited to the S pole.
On the other hand, the tooth portion 21a of the stator 2 is excited to the N pole, and the tooth portion 22a is excited to the S pole. The magnetic pole generated in the tooth portion 21a and the tooth portion 22a and the magnetic pole of the yoke 1b excited by the permanent magnet 1c and the permanent magnet 1d are attracted or repelled, so that a thrust toward the left in FIG. To do.

FIG. 7 shows a state where the mover 1 has advanced a distance corresponding to an electrical angle of 180 degrees from the state of FIG. In FIG. 7, the direction of the current flowing through the coil 1a is reversed. As a result, the flow of magnetic flux in FIG. 7 is in the opposite direction to the flow of magnetic flux shown in FIG. For this reason, an S pole is generated at the tooth portion 21a and an N pole is generated at the tooth portion 22a. Since the excitation of the yoke 1b by the permanent magnet 1c and the permanent magnet 1d does not change, the tooth portion 21a and the tooth portion 22a that are attracted / repulsed are opposite to those in FIG. A suction force is generated in the direction of the arrow shown in FIG. 7, and the mover 1 generates a leftward thrust with respect to the paper surface in FIG. 7. When the mover 1 advances a distance corresponding to an electrical angle of 180 degrees from the state of FIG. 7, the state is the same as that of FIG. By repeating the above operation, the mover 1 continues to move.

Next, the improvement of the impact due to the edge effect will be explained. The end effect means that in a linear motor, the influence of magnetic attraction and repulsive force generated at both ends of the mover affects the thrust characteristics (cogging characteristics, detent characteristics) of the motor. Conventionally, in order to reduce the end effect, measures such as making the shape of the tooth portions at both ends different from other shapes have been taken. The end effect occurs because the magnetic flux loop flows in the same direction as the moving direction (see FIG. 2 of Patent Document 1). However, in the linear motor according to the first embodiment, since the loop (magnetic flux loop) including the magnetic path passing through the stator 2 flows in a direction perpendicular to the traveling direction, it is possible to reduce the influence of the end effect. .

As described above, in the linear motor according to the first embodiment, unlike the conventional moving coil linear motor, the stator 2 does not need a permanent magnet, and the permanent magnet 1c and the permanent magnet 1d are used only for the mover 1. Therefore, even when the total length of the linear motor is lengthened, the amount of permanent magnets to be used does not increase and becomes constant, and the cost can be reduced. In addition, the influence of the end effect can be reduced.
The mover 1 has a minimum configuration of two yokes 1b, three permanent magnets 1c, and one permanent magnet 1d. Therefore, it becomes possible to widen the width in the moving direction of the permanent magnet 1c and the permanent magnet 1d provided in the mover 1, and to increase the width in the moving direction of the mover 1 of the tooth portion 21a and the tooth portion 22a. Thereby, it becomes possible to obtain a larger thrust than a stator of the same size having a large number of yokes 1b, permanent magnets 1c, and permanent magnets 1d.

Furthermore, a cooling pipe 11 is provided so as to be in contact with the outer surface of the coil 1a and surround the coil 1a, and the refrigerant flows through the cooling pipe 11. Thereby, since the coil 1a is cooled efficiently, it becomes possible to suppress the thrust drop by heat_generation | fever.

In the first embodiment, the movable element 1 is entirely sandwiched between the upper plate portion 21 and the lower plate portion 22, but in the present invention, the permanent magnet 1c, the permanent magnet 1d, and The yoke 1b only needs to be sandwiched between the upper plate portion 21 and the lower plate portion 22. A part or all of the coil 1 a may protrude from the stator 2 and may not be sandwiched between the upper plate portion 21 and the lower plate portion 22.
Moreover, although the yoke 1b, the permanent magnet 1c, and the permanent magnet 1d are rectangular parallelepiped, it is not limited thereto. Any magnetic flux circuit may be used as long as the magnetic flux generated by the excitation of the coil 1a constitutes a magnetic loop circuit in cooperation with the stator 2. For example, the yoke 1b, the permanent magnet 1c, and the permanent magnet 1d may be regular hexahedrons.

Embodiment 2
8A and 8B are explanatory views showing a configuration example of the mover 1 of the linear motor according to the second embodiment. FIG. 8A is a plan view showing a configuration example of the mover 1. 8B is a cross-sectional view taken along line VIII-VIII in FIG. 8A. In the second embodiment, the movable element 1 in which the longitudinal lengths of the yoke 1b and the

permanent magnets

1c and 1d in the first embodiment are increased. Moreover, the arrangement | sequence of the needle | mover 1 in the case of a three-phase drive is shown. Since other configurations are the same as those of the first embodiment, differences from the first embodiment will be mainly described in the following description.

The mover 1 according to the second embodiment is configured by arranging three similar single-

phase units

1U, 1V, and 1W along the moving direction. The single phase unit corresponding to the U phase is 1 U, the single phase unit corresponding to the V phase is 1 V, and the single phase unit corresponding to the W phase is 1 W.

FIG. 9 is an explanatory view showing a configuration example of the mover 1 attached to the mover base 4. The mover base 4 has a rectangular parallelepiped shape. On one surface of the mover base 4, grooves for fixing the single-

phase units

1U, 1V, 1W are provided. The single-

phase units

1U, 1V, and 1W are fitted and fixed in the grooves. The mover base 4 is made of a nonmagnetic material such as aluminum or nonmagnetic stainless steel. When the mover base 4 is attached to a linear guide or the like, the mover 1 moves directly between the two plate-

like portions

21 and 22 of the stator 2 facing each other.

The mover base 4 includes a liquid supply port 4a, a flow path 4b, and a liquid discharge port 4c. A single-

phase unit

1U, 1V, 1W cooling pipe 11 is connected to the middle of the flow path 4b. The flow path 4b may be a metal pipe embedded in the movable element base 4. Further, the movable element base 4 is constituted by a member divided into two in the thickness direction, grooves are engraved on one surface of each member, the surfaces provided with the grooves are joined together, and the movable element is formed by the engraved grooves. A space formed inside the base 4 may be used as the flow path 4b.

The liquid supply port 4a is connected to a cooling circuit (not shown), and a refrigerant is supplied from a pump (not shown). The refrigerant supplied from the liquid supply port 4a is discharged from the liquid discharge port 4c through the following path and returns to the cooling circuit. The refrigerant supplied from the liquid supply port 4a flows through the flow path 4b and flows into the cooling pipe 11 of the single-phase unit 1U from the liquid supply port 11a of the single-phase unit 1U. The refrigerant flowing through the cooling pipe 11 is discharged from the liquid discharge port 11b of the single-phase unit 1U to the flow path 4b of the mover base 4. The discharged refrigerant flows into the cooling pipe 11 of the single-phase unit 1V from the liquid supply port 11a of the single-phase unit 1V through the flow path 4b. The refrigerant that has flowed through the cooling pipe 11 is discharged from the liquid discharge port 11b of the single-phase unit 1V to the flow path 4b of the mover base 4. The discharged refrigerant flows into the cooling pipe 11 of the single-phase unit 1W from the liquid supply port 11a of the single-phase unit 1W via the flow path 4b. The refrigerant that has flowed through the cooling pipe 11 is discharged to the flow path 4b of the mover base 4 from the liquid discharge port 11b of the single-phase unit 1W. The discharged refrigerant passes through the flow path 4b and is discharged to the outside of the mover base 4 through the liquid discharge port 4c. As described above, when the refrigerant flows, the coils 1a of the single-

phase units

1U, 1V, and 1W are cooled.

In addition, the cooling pipe 11 may be provided only in a portion protruding from the mover base 4 in FIG. The part indicated by the dotted line in FIG. 9 may be a part different from the cooling pipe 11. In the mover base 4, the refrigerant flows through a flow path formed in the mover base 4.

The linear motor according to the second embodiment has the following effects in addition to the effects exhibited by the linear motor according to the first embodiment. Since the longitudinal lengths of the yoke 1b and the

permanent magnets

1c, 1d of the mover 1 are increased, a larger thrust can be obtained. Further, when the movable element 1 of the three-phase drive is used, a larger thrust can be obtained as compared with the case of the single phase.

Embodiment 3
10A and 10B are explanatory diagrams illustrating a configuration example of the mover 1 of the linear motor according to the third embodiment. FIG. 10A is a plan view illustrating a configuration example of the mover 1. FIG. 10B is a cross-sectional view taken along line XX of FIG. 10A. The difference between the third embodiment and the first embodiment is the coil 1a and the cooling structure of the coil 1a. In the third embodiment, the coil 1a is arranged in a cooling jacket 12 having substantially the same shape as the coil 1a, and the coil 1a is cooled by circulating a refrigerant between the inner wall of the cooling jacket 12 and the coil 1a.

The cooling jacket 12 has a rectangular frame shape. A yoke 1b and

permanent magnets

1c and 1d are arranged inside the frame shape of the cooling jacket 12. The frame-like portion of the cooling jacket 12 is a tube having a rectangular cross section. The cross section of the tube in which the coil 1a is housed is slightly larger than the cross section of the coil 1a. Similar to the cooling pipe 11, the cooling jacket 12 includes a liquid supply port 12 a and a liquid discharge port 12 b through which the refrigerant flows. The refrigerant flowing in from the liquid supply port 12a proceeds through the cooling jacket 12 while cooling the coil 1a in the cooling jacket 12, and is discharged from the liquid discharge port 12b.

The cooling jacket 12 may be composed of, for example, two members whose overall shape is divided into two in the thickness direction, and the two members may be joined after the coil 1a is disposed on one of the members. Alternatively, the resin may be molded (for example, injection molding) so as to have a gap between the coil 1a and the inner wall of the cooling jacket 12. The coil 1a is fixed from above and below, right and left, up and down, and left and right by a piece-like protrusion (not shown) protruding from the inner wall of the cooling jacket 12.

In the first embodiment, the coil 1a is cooled only from the outer side surface. However, in the third embodiment, the coil 1a is cooled from the inner side surface, the outer side surface, and both end surfaces. The material of the cooling jacket 12 may be a non-magnetic metal, but may be a resin molded one. The resin used for the cooling jacket 12 does not necessarily require a resin obtained by reinforcing the resin with glass fiber or the like, and does not require strength. The strength may be set as appropriate as long as it can withstand the acceleration / deceleration of the mover 1 and withstand the pressure of the necessary refrigerant. Depending on the conditions, hard plastics can also be used.
Of course, a resin jacket reinforced with glass fiber may be used.

The mover 1 of the linear motor of the present invention excites the yoke 1b of the mover 1 with the coil 1a and moves the mover 1 relative to the stator 2 by interaction with the

tooth portions

21a and 22a. Therefore, unlike the linear motor described in Patent Document 2 in which the magnetic force generated by the coil 1a is moved relative to the movable element 1 and the stator 2 by direct interaction with the magnetic force generated by the

permanent magnets

1c and 1d, the coil 1a And the

permanent magnets

1c and 1d have very little change in stress accompanying the movement of the mover 1.

In the linear motor of Patent Document 2, it is necessary to increase the strength of the coil 1a and the cooling jacket 12 for fixing the coil 1a so as to withstand this change in stress. However, this is not necessary in the present invention, and the strength of the cooling jacket 12 only needs to withstand the pressure of the refrigerant when the refrigerant is passed. Therefore, it is not necessary to reinforce the material of the cooling jacket 12 with glass fiber or the like.

The linear motor according to the third embodiment has the following effects. Since the

permanent magnets

1 c and 1 d are used only for the mover 1, even when the total length of the linear motor is increased, the amount of permanent magnets used is constant without increasing, and the cost can be reduced. In addition, the influence of the end effect can be reduced.
Further, the mover 1 has a minimum configuration of two yokes 1b and three

permanent magnets

1c and 1d. Therefore, it is also possible to increase the width in the moving direction of the

permanent magnets

1c and 1d included in the mover 1, and to increase the width in the moving direction of the mover 1 of the

tooth portions

21a and 22a. Thereby, it becomes possible to obtain a larger thrust than a stator of the same size having a large number of yokes 1b and

permanent magnets

1c and 1d.

Furthermore, since the coil 1a is disposed in the cooling jacket 12 through which the refrigerant flows, the coil 1a is cooled from the inner side surface, the outer side surface, and both end surfaces, so that the coil 1a can be efficiently cooled. Thereby, it becomes possible to suppress the thrust drop by the heat_generation | fever of the coil 1a.

Embodiment 4
11A and 11B are explanatory views showing a configuration example of the mover 1 of the linear motor according to the fourth embodiment. FIG. 11A is a plan view illustrating a configuration example of the mover 1. 11B is a cross-sectional view taken along line XI-XI in FIG. 11A. The mover 1 of the linear motor according to the fourth embodiment is a three-phase array of movers according to the third embodiment. Since other configurations are the same as those of the third embodiment, description thereof is omitted.

FIG. 12 is an explanatory diagram showing a configuration example of the mover 1 attached to the mover base 4 in the fourth embodiment. The difference from the second embodiment shown in FIG. 9 is that the coil 1a is arranged in the cooling jacket 12 having substantially the same shape as the coil 1a, and the refrigerant is circulated between the inner wall of the cooling jacket 12 and the coil 1a. Since the configuration of the mover base 4 is the same as that of the second embodiment, the description thereof is omitted.

The linear motor according to the fourth embodiment has the following effects in addition to the effects exhibited by the linear motor according to the third embodiment. By using three-phase driving, it is possible to obtain a larger thrust than in the case of a single phase.

Embodiment 5
13A and 13B are explanatory diagrams illustrating a configuration example of the mover 1 of the linear motor according to the fifth embodiment. 13A is a plan view showing a configuration example of the mover 1, and FIG. 13B is a cross-sectional view taken along line XIII-XIII in FIG. 13A. FIG. 14 is an explanatory diagram showing a configuration example of the mover 1 attached to the mover base 4 in the fifth embodiment. The difference from the second embodiment (FIGS. 8 and 9) is that the number of yokes 1b and

permanent magnets

1c and 1d is changed. Omitted.

In the linear motor according to the fifth embodiment, since the number of yokes 1b and

permanent magnets

1c and 1d is increased, the mover 1 can be moved more smoothly.

Embodiment 6
FIG. 15 is a plan view showing a configuration example of the mover 1 of the linear motor according to the sixth embodiment. The difference from the first embodiment is the width in the moving direction of the yoke located at the center. In the sixth embodiment, among the three

yokes

1b and 10b arranged along the moving direction of the mover 1, the width in the moving direction of the yoke 10b located in the center and the yoke 1b located on the left and right is different. To do. The width d2 of the yoke 10b is twice the width d1 of the yoke 1b. This is to make it difficult for magnetic saturation to occur when the magnetic flux flowing through the

yokes

1b and 10b increases as the coil current increases. The yoke 1b located on the left and right exchanges the magnetic flux from one

permanent magnet

1c or 1d with the

tooth portion

21a or 22a, whereas the yoke 10b located on the center receives the magnetic flux from the two

permanent magnets

1c and 1d. Exchanges with the

unit

21a or 22a. Therefore, it is preferable that the width d2 of the yoke 10b located at the center is twice the width d1 of the yoke 1b located on the left and right.

16A and 16B are explanatory diagrams for the magnetic saturation of the yoke of the mover 1. FIG. FIG. 16A shows the case of the mover 1 according to the sixth embodiment. FIG. 16B shows the case of the mover 1 according to the first embodiment. A dotted line from the tooth portion 21a through the yoke 1b, the

permanent magnet

1c or 1d to the tooth portion 22a through the

yoke

1b or 10b indicates the flow of magnetic flux. In the sixth embodiment, the yoke sandwiched between the two

permanent magnets

1c and 1d, that is, the yoke 10b located in the center, has a wider width (length) in the moving direction than the yoke 1b in the first embodiment. Therefore, the density of magnetic flux is difficult to increase, and magnetic saturation is difficult to occur. Thus, even if the current of the coil 1a is increased, the yoke 10b is less likely to cause magnetic saturation, and thus the thrust linearity when the current of the linear motor increases is improved. The flow of magnetic flux shown in FIG. 16 is shown as an example.
The width d2 is not limited to twice the width d1. If the width d2 is twice or more, the yoke 10b is less likely to be magnetically saturated. However, even if magnetic saturation does not occur at 10b, magnetic saturation occurs at the yokes 1b at both ends, so the width d2 is preferably twice the width d1. When the width d2 is less than twice, magnetic saturation is less likely to occur in the yoke 10b than when the width d2 is equal to the width d1, but before the yoke 1b at both ends is subjected to magnetic saturation, the magnetic saturation occurs in the yoke 10b. Will happen. Since the dimension in the moving direction of the mover 1 is determined by the widths d1 and d2, how to set the widths d1 and d2 may be determined in consideration of the above points.

In the above-described linear motor, when a three-phase drive configuration is adopted, the pitch between each single-phase unit is n times 2/3 the pitch of the

teeth

21a and 22a of the stator 2 (3 minutes). (Integer multiple of 2). The value of the integer n may be set in consideration of the length of each single-phase unit in the moving direction.

Embodiment 7
17A and 17B are explanatory views showing a configuration example of the mover 1 of the linear motor according to the seventh embodiment. FIG. 17A is a plan view illustrating a configuration example of the mover 1. FIG. 17B is a cross-sectional view taken along line XVII-XVII in FIG. 17A. The mover 1 of the linear motor according to the seventh embodiment has a configuration in which three

unit movers

101, 102, 103 arranged in three phases are connected. Each of the

unit movers

101, 102, 103 has a cooling jacket (cooling unit) 12. The cooling jacket 12 has a ladder shape in which rectangular frames are connected. The inside of the cooling jacket 12 is a cavity (hollow). A coil 1 a is disposed inside each cooling jacket 12. That is, the cooling jacket 12 includes a coil. A yoke 1b and

permanent magnets

1c and 1d are arranged in each space enclosed by a rectangular frame.

The configuration of each of the

unit movers

101, 102, 103 is the same as that of the fourth embodiment. Each phase includes three yokes 1b and a set of

permanent magnets

1c and 1d inside the coil 1a. The yoke 1b and the

permanent magnets

1c and 1d are alternately arranged along the moving direction. The

permanent magnets

1c and 1d sandwiching the central yoke 1b are magnetized along the moving direction, and the directions thereof are opposite to each other. The

unit movers

101, 102, and 103 are fixed by the mover base 4 shown in FIG.

The cooling jacket 12 is provided with a liquid supply port 12a and a liquid discharge port 12b, respectively. During operation of the linear motor, the

unit movers

101, 102, and 103 are cooled by supplying the refrigerant from the liquid supply port 12a and discharging the refrigerant from the liquid discharge port 12b. The refrigerant flowing in from the liquid supply port 12a cools the periphery of each coil 1a in the order of the coil 1a close to the liquid supply port 12a, the central coil 1a, and the coil 1a close to the liquid discharge port 12b, and is discharged from the liquid discharge port 12b. Is done. The configuration of the refrigerant flow path, the liquid supply port 12a, and the liquid discharge port 12b is not limited thereto. For example, the liquid supply port 12a may be provided at a position close to the central coil 1a, and the liquid discharge port 12b may be provided at two positions close to the coils 1a on both sides. In this case, the refrigerant flowing in from the liquid supply port 12a is divided into two, and one of the divided refrigerants cools one of the central coil 1a and the coil 1a at both ends, and discharges it from one liquid discharge port 12b. The same applies to the cooling of the other coil.

The linear motor according to Embodiment 7 has the following effects. Since the mover 1 is composed of the three

unit movers

101, 102, and 103, the winding of the coil 1a of each phase included in each unit mover is more than the case where the mover 1 is constituted by one unit mover. Can also be reduced. As a result, the amount of heat generated by the coil 1a can be reduced. By reducing the number of turns of the coil 1a, the thrust generated in each unit mover is reduced, but by increasing the number of unit movers, the thrust of the entire mover 1 can be ensured. By changing the number of unit movers from one to three, it is possible to reduce the number of turns of each coil 1a from ¼ to ３.

The linear motor according to Embodiment 7 is effective when the required specifications are as follows. With one unit mover, the heat generation is too large and the ambient temperature does not meet the specifications. In this case, the cooling can be performed by increasing the flow rate of the refrigerant, but the flow rate of the refrigerant may not be increased in relation to other devices. In such a case, by reducing the number of turns of the coil 1a and reducing the heat generated by each unit mover, it is possible to ensure an appropriate ambient temperature without increasing the flow rate of the refrigerant. Since the number of unit movers is increased instead of increasing the number of windings of the coil 1a, the necessary thrust can be secured.

Embodiment 8
18A and 18B are explanatory views showing a configuration example of the mover 1 of the linear motor according to the eighth embodiment. FIG. 18A is a plan view showing a configuration example of the mover 1. 18B is a cross-sectional view taken along line XVIII-XVIII in FIG. 18A. The mover 1 of the linear motor according to the eighth embodiment is different from the mover 1 of the seventh embodiment in the structure of the cooling jacket 12. Since the structure other than the structure of the cooling jacket 12 is the same as that of the seventh embodiment, the following description will mainly focus on the cooling jacket 12.

The cooling jacket 12 has a ladder shape in which a plurality of rectangular frame shapes are connected. The inside of the cooling jacket 12 is a cavity. A coil 1 a is disposed inside the cooling jacket 12. As in the seventh embodiment, a yoke 1b and

permanent magnets

1c and 1d are arranged in each space enclosed by a rectangular frame.

The cooling jacket 12 has a structure capable of cooling

unit movers

101, 102, and 103 having three phases together. The cooling jacket 12 is provided with a liquid supply port 12a and a liquid discharge port 12b. During the linear motor operation, the whole movable element 1 is cooled by supplying the refrigerant from the liquid supply port 12a and discharging the refrigerant from the liquid discharge port 12b.

The coolant flow path flows in from the liquid supply port 12a, cools in order from the coil 1a near the liquid supply port 12a to the coil 1a near the liquid discharge port 12b, and then discharges from the liquid discharge port 12b. good. In addition, you may provide a bypass and a branch in a flow path. Further, a plurality of liquid supply ports 12a and a plurality of liquid discharge ports 12b may be provided.

The linear motor according to the eighth embodiment has the following effects in addition to the effects exhibited by the linear motor according to the seventh embodiment. By integrating the cooling jacket 12, it is possible to increase the strength of fixing the

unit movers

101, 102, and 103 together. In addition, since the cooling jacket 12 is integrated, it is possible to efficiently cool the mover 1 as a whole by providing a bypass and a branch.

The technical features (components) described in each embodiment can be combined with each other, and a new technical feature can be formed by combining them.
The embodiments disclosed herein are illustrative in all respects and should not be considered as restrictive. The scope of the present invention is defined not by the above-mentioned meaning but by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

1 Movable Element 1a Coil 1b Yoke 1c, 1d Permanent Magnet (Magnet)
DESCRIPTION OF SYMBOLS 11 Cooling pipe 11a Liquid supply port 11b Drainage port 12 Cooling jacket 12a Liquid supply port 12b Drainage port 2 Stator 21 Upper plate part (plate-shaped part)
21a tooth part 22 lower plate part (plate-like part)
22a tooth part 23 side plate part 4 movable element base 4a liquid supply port 4b flow path 4c drainage port

Claims

In a linear motor having a stator and a mover,
The stator is
Having two plate-like portions facing each other magnetically coupled with the moving range of the mover in between,
On each of the two plate-like portions facing each other, a plurality of tooth portions are staggered between the tooth portions of one plate-like portion and the tooth portions of the other plate-like portion. It is juxtaposed in the moving direction,
The mover is
Inside the coil, a plurality of permanent magnets and a plurality of yokes are alternately arranged along the moving direction,
The permanent magnets adjacent via the yoke are magnetized in directions facing each other,
Furthermore, it has a cooling part which cools the said coil, The linear motor characterized by the above-mentioned.
The linear motor according to claim 1, wherein the cooling unit includes a cooling pipe, and the cooling pipe is disposed on an outer surface of the coil.
A length of the coil and the cooling pipe in a direction perpendicular to the two plate-like portions is equal to or less than a length of the permanent magnet and the yoke in a direction perpendicular to the two plate-like portions. The linear motor according to claim 2.
The linear motor according to claim 1, wherein the cooling unit is a cooling jacket including the coil.
The length of the cooling jacket in the direction perpendicular to the two plate-like portions is equal to or less than the length of the permanent magnet and the yoke in the direction perpendicular to the two plate-like portions. The linear motor described.
The linear motor according to any one of claims 1 to 5, wherein the mover has two permanent magnets and three yokes.
The linear motor according to claim 6, wherein a yoke sandwiched between the two permanent magnets is longer in the moving direction than the other two yokes.
The linear motor according to claim 7, wherein a length of the yoke sandwiched between the two permanent magnets is twice as long as the other two yokes.
In a linear motor having a stator and a mover,
The stator is
Having two plate-like portions facing each other magnetically coupled with the moving range of the mover in between,
On each of the two plate-like portions facing each other, a plurality of tooth portions are staggered between the tooth portions of one plate-like portion and the tooth portions of the other plate-like portion. It is juxtaposed in the moving direction,
The mover is
A cooling unit and a plurality of unit movers;
Each unit mover has three coils arranged along the moving direction,
Inside each coil, a plurality of permanent magnets and a plurality of yokes are alternately arranged along the moving direction,
A linear motor characterized in that the permanent magnets adjacent via the yoke are magnetized in directions facing each other.
The cooling unit is provided corresponding to each unit mover,
10. The linear motor according to claim 9, wherein each cooling unit has a hollow shape including each coil, and surrounds the plurality of permanent magnets and the plurality of yokes.
The linear motor according to claim 9, wherein the cooling section is hollow, includes all the coils of the mover, and surrounds the plurality of permanent magnets and the plurality of yokes.