JP3789671B2 - Linear motor stator and manufacturing method thereof - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a stator for a linear motor and a method for manufacturing the same, and more particularly to a stator for a linear motor that drives a reciprocating compressor and a method for manufacturing the same.
[0002]
[Prior art]
Conventionally, this type of linear motor is disclosed in, for example, Japanese Patent Laid-Open No. 10-146037 [H02K 33/18]. As schematically shown in FIGS. 11 (a) and 11 (b), this motor has a cylindrical outer yoke 1 made of a wound iron core, and is provided inside the outer yoke 1 with a predetermined gap from the outer yoke 1. A cylindrical inner yoke 2 made of a wound core, and a pair of side yokes 3 made of laminated steel plates that are in close contact with the end faces of the outer yoke 1 and the inner yoke 2 and connect and integrate the outer yoke 1 and the inner yoke 2 together. 3, a permanent magnet 4 fixed inside the outer yoke 1, a movable coil 6 disposed in the gap 5 between the permanent magnet 4 and the inner yoke 2, and a coil support 7 that supports the movable coil 6, The shaft 8 is connected and integrated, and is displaced in the axial direction in the inner circumferential yoke 2.
[0003]
That is, the outer yoke 1 and the inner yoke 2 constituting the stator of the linear motor are both formed of wound iron cores, and the side yoke 3 that is closely connected to and integrated with the end surfaces of the yokes 1 and 2 is a laminated steel plate. Therefore, there is an advantage that the loss due to the eddy current is reduced, and as a result, the motor efficiency is improved.
[0004]
[Problems to be solved by the invention]
However, in the above-described structure, the outer yoke 1 and the inner yoke 2 are constituted by the wound iron core, so that a portion where the magnetic flux flows at right angles to the steel plate is generated near the junction between the circumferential front surface and the side yoke. In other words, there are new problems that eddy current loss increases, assembly and manufacturing are very complicated and troublesome, and cost is increased.
[0005]
SUMMARY OF THE INVENTION Therefore, a main object of the present invention is to provide a linear motor stator that is easy to assemble and manufacture, is inexpensive in terms of cost, and is efficient with reduced eddy current loss, and a method for manufacturing the same.
[0006]
[Means for Solving the Problems]
The present invention relates to a stator for a linear motor having a cylindrical outer yoke and a cylindrical inner yoke disposed inside the outer yoke with a predetermined gap therebetween. The inner yoke is a columnar holding member, A plurality of laminated block bodies each fixed to a plurality of mounting surfaces formed on the outer surface of the member, and each laminated block body is formed by laminating magnetic steel plates bent in a convex shape toward the center in the radial direction. A stator of a linear motor.
[0007]
Further, the present invention provides a stator for a linear motor having a cylindrical outer yoke and a cylindrical inner yoke disposed inside the outer yoke with a predetermined gap therebetween, and the inner yoke is disposed at the periphery of the stator. A linear steel sheet comprising: a magnetic steel plate having a plurality of substantially parallel slit-shaped holes provided radially with respect to the center; and a columnar laminate having a plurality of through holes obtained by laminating magnetic steel plates. This is a motor stator.
[0008]
According to another aspect of the present invention, there is provided a linear motor stator having a cylindrical outer yoke and a cylindrical inner yoke disposed inside the outer yoke with a predetermined gap therebetween. (A) The inner yoke is attached to the outer surface. A step of manufacturing a columnar holding member having a plurality of surfaces, (b) a step of manufacturing a plurality of laminated block bodies formed by laminating curved magnetic thin plates in a radial direction, and (c) attachment of the holding member. And a step of fixing a plurality of laminated block bodies to the surface, respectively.
[0009]
Further, the present invention provides a stator for a linear motor having a cylindrical outer yoke and a cylindrical inner yoke arranged with a predetermined gap inside the outer yoke, wherein (a) the inner yoke is a peripheral portion thereof. A step of manufacturing a magnetic steel plate having a plurality of substantially parallel slit-shaped holes provided radially with respect to the center, and (b) laminating the magnetic steel plates in the axial direction and fixing the plurality of holes to penetrate. And a step of manufacturing a columnar laminated body. A method for manufacturing a stator for a linear motor.
[0010]
[Action]
When a linear motor stator is constituted by a cylindrical outer yoke and a cylindrical inner yoke arranged on the inner side of the outer yoke with a predetermined gap, particularly an inner yoke located inside the outer yoke. Is formed by fixing a plurality of block bodies formed by radially laminating magnetic steel plates curved toward the center on each mounting surface of a columnar holding member. It can be performed at low cost, and loss due to eddy current can be reduced. In addition, a magnetic steel sheet having a plurality of slit-shaped holes provided radially around its center is fixed in an axial direction, and a plurality of through holes are filled with a magnetic material. The same applies to the case of forming a columnar laminated body serving as a circumferential yoke.
[0011]
【The invention's effect】
According to the present invention, a laminated block body formed by laminating magnetic steel plates bent convexly with respect to the center in the radial direction or a magnetic having a plurality of slit-shaped holes radially around the center with respect to the center. Since a linear motor stator can be manufactured by arranging a laminate formed by laminating steel plates in the axial direction, not only reducing eddy current loss, but also improving the dimensional accuracy of the stator and reducing manufacturing costs. Is possible.
[0012]
The above object, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.
[0013]
【Example】
An embodiment according to the present invention will be described below with reference to FIGS.
First, a moving magnet (MM) type linear motor 10 according to the first embodiment shown in FIG. 1A includes a fixed portion 12 and a movable portion 14 that can move in the horizontal direction indicated by an arrow in the figure with respect to the fixed portion 12. And consists of The fixed portion 12 includes a doughnut-shaped stator storage case 16 composed of a regular octagonal outer cylinder 16 a and a circular inner cylinder 16 b formed of a non-magnetic material such as stainless steel, and is stored in the storage case 16. It includes a stator 18 that is held.
[0014]
The stator 18 includes regular octagonal outer yokes 20, 20,... Formed by laminating magnetic steel plates in the circumferential direction, and a cylindrical inner periphery disposed inside the outer yoke 20 with a predetermined gap therebetween. There is a yoke 22, a bottom yoke 24 formed by laminating a ring-shaped magnetic steel plate that connects and integrates the bottoms of both yokes 20 and 22, and an inner peripheral yoke 22 and a gap d inside the outer yoke 20. A front yoke 26 formed by stacking ring-shaped magnetic steel plates to be fixed together, and a stator coil 28 located between the bottom yoke 24 and the front yoke 26 and disposed inside the outer yoke 20. The
[0015]
The inner circumferential yoke 22 of the stator 18 has a plurality of, for example, eight laminated block bodies 32, 32,... Formed by laminating magnetic steel plates 30 curved in a convex shape toward the center in the radial direction. Each of the laminated block bodies 32 is attached and fixed to a mounting surface formed on the outer surface by using a screw or an adhesive, and the cross-sectional shape having a through hole 34 in the center includes a star-shaped columnar magnetic holder 36, for example. The four laminated block bodies 32, 32, 32, 32 are fixed to a columnar magnetic holding body 36 having a substantially rhombic cross section, and curved in an arc shape to form each laminated block body 32. The magnetic steel plates 30 thus obtained are shown in FIGS. 9 (a) and 9 (b), respectively.
[0016]
On the other hand, as shown in FIG. 1 (b), the movable portion 14 that is displaced in the horizontal direction is provided with a bottomed cylindrical movable holding body 38, penetrating through the center of the bottom of the movable holding body 38, and accommodated in the stator. It includes a shaft portion 40 that passes through the inner cylinder 16 b of the case 16 and a cylindrical permanent magnet 42 that is fixed to the open end of the movable holding body 38. The permanent magnet 42 has a pair of permanent magnet pieces 42a and 42b each having a magnetization vector opposite in the radial direction arranged and fixed in the axial direction.
[0017]
In such a configuration, when an alternating current is applied to the stator coil 28, the magnetic flux generated by the current according to the direction of the current acts on the permanent magnet pieces 42a and 42b of the movable portion 14, and the magnetic flux is strengthened. The permanent magnet 42 moves and the movable part 14 is displaced rightward or leftward. Therefore, air or a refrigerant can be compressed by connecting, for example, a piston that slides in a cylinder of a reciprocating compressor to the shaft portion 40 of the MM type linear motor 10.
[0018]
In this first embodiment, each laminated block body 32 constituting the cylindrical inner yoke 22 of the stator 18 is made of a magnetic steel plate 30 whose cross-sectional shape is curved in an arc as shown in FIG. Although formed by laminating in the radial direction, as a modification, as shown in FIG. 7 (b) or (c), a magnetic steel sheet 30 whose cross-sectional shape is bent in a U shape or a square shape is laminated in the radial direction. May be formed. In this case, in the former, the columnar magnetic holding body 36 for mounting and fixing the respective laminated block bodies 32 has a starfish shape in cross section, and in the latter, a star shape in cross section may be used.
[0019]
Next, a second embodiment shown in FIG. 2 will be described.
Compared with the first embodiment shown in FIGS. 1A and 1B, the second embodiment is different in the configuration of the inner peripheral yoke 22 of the stator 18 and the other configurations are the same. The same figure number is attached to and the description thereof is omitted. That is, as shown in FIGS. 2A and 2B, the inner circumferential yoke 22 in this embodiment is formed by laminating circular magnetic steel plates 30 in the axial direction and fixing with caulking or an adhesive. . Each magnetic steel plate 30 is formed with a circular hole 30a at the center and eight groups of arc-shaped slit holes 30b that are convex with respect to the center are formed around the circular hole 30a. When the magnetic steel plates 30 are laminated in the axial direction, they may be laminated so that the slit holes 30b,... Overlap, but may be laminated while sequentially shifting the slit holes 30b.
[0020]
As yet another modification, it is possible to form a circular magnetic steel sheet by combining fan-shaped magnetic steel sheets, and to have a laminated structure, and further, a slit that penetrates the columnar metal body of an integral body. A hole may be provided.
Further, the shape of the slit hole 30b may be an arc shape as in this embodiment shown in FIG. 8 (a), but may be a straight shape as shown in FIG. 8 (b) or (c). . Furthermore, the strength and performance can be improved by filling each slit hole 30b with an appropriate magnetic material. As the magnetic material, for example, a synthetic resin material may be mixed with magnetic powder.
[0021]
10A and 10B, a circular hole 30a is formed at the center and a circular group is formed with four groups of arc-shaped slit holes 30b,... A quarter portion of the inner steel yoke 22 configured by laminating and fixing the magnetic steel plate 30 in the axial direction and the magnetic steel plate 30 serving as a unit unit is shown as an illustrative view.
Further, a third embodiment shown in FIG. 3 will be described.
[0022]
As shown in FIGS. 3A and 3B, the third embodiment is a moving iron (MI) type linear motor. Compared with the first embodiment, the permanent magnet 42 is connected to the front yoke of the stator 18. 26 is the same as the other structure except that the movable iron core 44 is fixed to the inner surface side of the movable holding body 38 and the movable iron core 44 is formed by laminating a ring-shaped magnetic steel plate on the opening end of the movable holding body 38. A number is assigned and description thereof is omitted.
[0023]
In this embodiment, the dimension of the front yoke 26 is increased in accordance with the length dimension of the permanent magnet 40, and the laminated thickness of the movable iron core 44 is ½ of the length dimension of the permanent magnet 40. In this embodiment, the laminated block body 32 in which the inner circumferential yoke 22 of the stator 18 is laminated in the radial direction with the magnetic steel plates 30 curved in an arc like the first embodiment is mounted and fixed to the magnetic holding body 36. However, as in the second embodiment, a circular magnetic steel sheet 30 in which a plurality of groups of slit holes 30b... Are formed in the periphery of the center hole may be laminated in the axial direction.
[0024]
A fourth embodiment shown in FIG. 4 will be described.
As shown in FIGS. 4A and 4B, this embodiment is a moving coil (MC) type linear motor. Compared with the first embodiment, the front yoke 26 is removed and the inner side of the outer yoke 20 is removed. A cylindrical permanent magnet 42 is fixed to a movable holding body 38, and a movable coil 46 is attached to the opening end of the movable holding body 38. The description is omitted.
[0025]
In this case as well, the inner peripheral yoke 22 of the stator 18 may be configured by laminating a circular magnetic steel plate 30 having a plurality of groups of slit holes 30b...
A fifth embodiment shown in FIG. 5 will be described.
As shown in FIGS. 5A and 5B, this embodiment is a moving magnet (MM) type linear motor, and in the first embodiment, all the parts constituting the fixed portion 12 and the movable portion 14 are correct. Since it is an octagonal shape, the other components are the same as those in the first embodiment, and the same reference numerals are assigned to omit the description. In addition to the MM type, a polygonal structure can be adopted for a moving iron (MI) type and a moving coil (MC) type linear motor.
[0026]
Finally, a sixth embodiment shown in FIG. 6 will be described.
As shown in FIGS. 6A and 6B, this embodiment is a moving coil (MC) type linear motor, which is only a modification of the fourth embodiment. That is, in the fourth embodiment, the bottom yoke 24 is deleted and a gap is provided in the front and rear. Also in this case, the inner yoke 22 may have a slit structure as in the second embodiment.
[Brief description of the drawings]
FIGS. 1A and 1B are illustrative views showing different cross-sectional shapes of a first embodiment of an MM type linear motor embodying the present invention.
FIGS. 2A and 2B are illustrative views showing different cross-sectional shapes of a second embodiment according to the present invention. FIGS.
FIGS. 3A and 3B are illustrative views showing different cross-sectional shapes of a third embodiment according to the present invention. FIGS.
4 (a) and 4 (b) are illustrative views showing different cross-sectional shapes of a fourth embodiment according to the present invention.
FIGS. 5A and 5B are illustrative views showing different cross-sectional shapes of a fifth embodiment according to the present invention. FIGS.
FIGS. 6A and 6B are illustrative views showing different cross-sectional shapes of a sixth embodiment according to the present invention. FIGS.
FIGS. 7A, 7B and 7C are plan views of inner yokes (laminate structures) of different embodiments according to the present invention. FIGS.
FIGS. 8A, 8B, and 8C are plan views of inner yokes (slit structures) according to different embodiments of the present invention. FIGS.
FIGS. 9A and 9B are oblique views showing an inner circumferential yoke (laminate structure) according to an embodiment of the present invention and a magnetic steel plate curved in an arc shape forming the yoke.
FIGS. 10A and 10B are oblique views showing an inner yoke (slit structure) according to another embodiment of the present invention and a part of a circular magnetic steel sheet forming the yoke.
FIGS. 11A and 11B are a cross-sectional view of a main part and a vertical cross-sectional view showing a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Linear motor 12 ... Fixed part 14 ... Movable part 16 ... Stator storage case 18 ... Stator 20 ... Outer yoke 22 ... Inner yoke 28 ... Stator coil 30 ... Magnetic steel plate 30a ... Center hole 30b ... Slit hole 32 ... Laminated block body 34 ... through hole 36 ... magnetic holder 38 ... movable holder 40 ... movable shaft 42 ... permanent magnet 44 ... movable iron core 46 ... movable coil

Claims (13)

A linear motor stator having a cylindrical outer yoke and a cylindrical inner yoke arranged with a predetermined gap inside the outer yoke,
The inner yoke is a columnar holding member,
A plurality of laminated block bodies respectively fixed to a plurality of mounting surfaces formed on the outer surface of the holding member;
Each of the laminated block bodies is formed by laminating magnetic steel plates bent convexly toward the center in a radial direction. The stator of a linear motor according to claim 1, wherein the magnetic steel plate constituting each of the laminated block bodies is bent in a circular arc shape, a square shape, or a U shape in cross section. The stator of the linear motor according to claim 1, wherein the holding member is made of a magnetic material. 4. The linear motor stator according to claim 1, wherein the laminated block body is fixed to the mounting surface of the holding member by screws or an adhesive, respectively. 5. A linear motor stator having a cylindrical outer yoke and a cylindrical inner yoke arranged with a predetermined gap inside the outer yoke,
The inner yoke has a magnetic steel plate having a plurality of substantially parallel slit-shaped holes provided radially at the periphery of the inner yoke, and a columnar laminate having a plurality of through holes obtained by laminating the magnetic steel plates. A linear motor stator comprising a body. A linear motor stator having a cylindrical outer yoke and a cylindrical inner yoke arranged with a predetermined gap inside the outer yoke,
The stator of a linear motor, wherein the inner peripheral yoke is formed of a columnar magnetic metal body having a plurality of substantially parallel slit-shaped through holes provided radially at the periphery of the inner yoke. The stator of the linear motor according to claim 5 or 6, further comprising a magnetic material in the plurality of through-holes of the inner peripheral yoke. The linear motor stator according to claim 7, wherein the magnetic material is a synthetic resin material mixed with magnetic powder. In a linear motor stator having a cylindrical outer yoke and a cylindrical inner yoke arranged with a predetermined gap inside the outer yoke,
(A) a step of manufacturing a columnar holding member having a plurality of mounting surfaces on the outer surface of the inner yoke;
(B) producing a plurality of laminated block bodies formed by laminating curved magnetic thin plates in the radial direction;
(C) A method for manufacturing a stator of a linear motor, comprising: fixing each of the plurality of laminated block bodies to the mounting surface of the holding member. In a linear motor stator having a cylindrical outer yoke and a cylindrical inner yoke arranged with a predetermined gap inside the outer yoke,
(A) a step of manufacturing a magnetic steel plate having a plurality of substantially parallel slit-like holes provided radially around the center of the inner peripheral yoke, and (b) the magnetic steel plate in the axial direction. A method of manufacturing a linear motor stator, comprising: a step of stacking and fixing a plurality of holes to pass through and manufacturing a columnar stacked body. The linear motor stator manufacturing method according to claim 10, further comprising: (c) filling the plurality of through holes with a magnetic material. In a linear motor stator having a cylindrical outer yoke and a cylindrical inner yoke arranged with a predetermined gap inside the outer yoke,
(A) the inner peripheral yoke has a step of manufacturing a columnar magnetic metal body; and (b) a plurality of axially penetrating radial magnetic metal members disposed in the periphery of the magnetic metal body with respect to the axial center. And a step of manufacturing a substantially parallel slit-like hole. (C) The method of manufacturing a stator for a linear motor according to claim 12, further comprising a step of filling the plurality of slit-shaped holes penetrating with a magnetic material.

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