JP5652669B2 - Field yoke assembly and linear motor - Google Patents

Description

  The disclosed embodiments relate to a field yoke assembly and a linear motor including the same.

  Patent Document 1 describes a coreless linear motor. This linear motor includes a field yoke in which a plurality of permanent magnets having different polarities are arranged next to each other, and a permanent magnet array and a magnetic gap, and is disposed opposite to each other, and a plurality of coil groups in a concentrated winding. Is fixed by a resin mold, and includes a coreless armature having an armature coil formed in a flat plate shape, with one of the field yoke and the armature as a stator and the other as a mover. The field yoke and the armature are moved relatively.

JP 2001-86726 A

  The linear motor includes a field yoke assembly having a substantially U-shaped cross section including two flat field yokes and a field yoke fixing plate that supports them in a cantilever shape in parallel. Inside the field yokes of the field yoke assembly, a plurality of permanent magnets arranged so as to have different polarities alternately in the relative movement direction are fixed so as to have different polarities from the opposing permanent magnets.

  In the linear motor configured as described above, if a strong permanent magnet is used to obtain a high output, the field yoke is greatly deflected by the attractive force between the magnets arranged opposite to each other. There is a risk that the gap cannot be secured. In order to reduce this bending, it is necessary to increase the rigidity of the field yoke by increasing the thickness of the field yoke, but there is a problem that it is difficult to reduce the size and weight of the motor.

  The present invention has been made in view of such problems, and an object thereof is to provide a field yoke assembly and a linear motor capable of obtaining a high output while achieving a reduction in size and weight.

  In order to solve the above-described problem, according to one aspect of the present invention, the field and the armature can be moved relatively by using one of the field and the armature as a mover and the other as a stator. A field yoke assembly used for a linear motor, two yoke plates arranged opposite to each other, and a yoke fixing portion that supports the two yoke plates in a cantilever shape at one end of the yoke plate There is provided a field yoke assembly configured such that the gap between the two yoke plates is larger at the other end than at the one end.

  According to the present invention, a high output can be obtained while reducing the size and weight of a linear motor.

It is a perspective view showing the appearance of the linear motor concerning one embodiment. It is the front view of the linear motor seen from the arrow A in FIG. 1, and is the figure which permeate | transmitted a part of mover and represented the cross section. It is a front view showing the field yoke assembly before and after attachment of a permanent magnet. It is a front view showing the field yoke assembly before and after attachment of the permanent magnet in a modification in which the yoke plate itself is processed into a warped shape in advance. It is explanatory drawing showing the bending method with the rolling roller of the yoke plate of the curved shape, and the grinding method with a grinding machine etc. It is a front view showing the field yoke assembly before and after the attachment of the permanent magnet in a modified example in which the yoke plate is supported in an expanded shape by the yoke fixing portion. Front view showing a field yoke assembly before, after, and after driving a linear magnet in a modification in which a plate having a low coefficient of thermal expansion is bonded to the outside of a yoke plate It is.

  Hereinafter, an embodiment will be described with reference to the drawings.

<Configuration of linear motor>
As shown in FIGS. 1 and 2, the linear motor 100 according to the present embodiment includes a stator 1 serving as a field and a mover 2 having an armature 3. The stator 1 has two yoke plates 11, a yoke fixing portion 12, a plurality of permanent magnets 13, and a plate 15. The two yoke plates 11 are the same long and substantially rectangular flat plates, and are arranged so as to face each other over the longitudinal direction of the stator 1. The yoke fixing portion 12 has a substantially U-shaped cross-sectional shape in the width direction of the stator 1 and is provided over the entire longitudinal direction. One side of the two yoke plates 11 (the lower side in FIGS. 1 and 2). The end portions are connected to support the yoke plate 11 in a cantilever shape.

  Each of the plurality of permanent magnets 13 is formed of a substantially rectangular flat plate that is short in the longitudinal direction of the stator 1, and is provided in a pair so as to oppose each opposing surface of each yoke plate 11. . Such a plurality of sets of permanent magnets 13 are arranged in parallel at a predetermined interval along the longitudinal direction of the stator 1, that is, permanent magnet rows 14 along the longitudinal direction are respectively provided on the inner side surfaces of the yoke plates 11. Is provided. In the two permanent magnets 13 facing each other in the same set, the directions of the magnetic poles are opposite to each other in the facing direction, that is, the width direction of the stator 1, and the two permanent magnets 13 adjacent in the longitudinal direction of the stator 1. However, the directions of the magnetic poles are opposite to each other.

  A groove 12a is formed on the upper surface of the yoke fixing portion 12 in the longitudinal direction, and the width of the groove 12a is set to be approximately the same as the interval between the pair of permanent magnets 13 described above. For this reason, as shown in FIG. 3, the shape which looked at the stator 1 whole from the front is a substantially U shape.

  The plate 15 is a flat plate having substantially the same shape as the yoke plate 11, and is formed thinner than the yoke plate 11 in this example. The plates 15 are respectively fixed to the outside of the two yoke plates 11 and are made of a metal material different from that of the yoke plates 11.

  As shown in FIG. 2, the mover 2 includes an armature base 21, a printed circuit board 22, a plurality of armature coils 24, and a mold resin 25. The armature base 21 has a substantially rectangular parallelepiped shape, and the length in the longitudinal direction is shorter than the length of the stator 1. The printed circuit board 22 is a substantially rectangular thin plate having the same length as the armature base 21, and wirings for supplying electric power to the plurality of armature coils 24 are printed thereon. The armature coil 24 is an air-core type concentrated winding coreless coil. Each armature coil 24 is fixed to the printed circuit board 22 by a mold resin 25.

  As shown in FIG. 2, the entire armature coil 24 fixed to one surface of the printed circuit board 22 by the mold resin 25 constitutes the armature 3, and the upper side of the substantially plate-like armature 3 is The entirety that is inserted into and fixed to the groove 21 a on the lower surface of the armature base 21 constitutes the mover 2. The coreless linear motor 100 is configured in a state where the armature 3 provided on the lower side of the mover 2 is inserted between the two permanent magnet rows 14 in the stator 1. The configuration of the armature 3 is not limited to the above. For example, the armature coils 24 may be arranged on both sides of the printed board 22.

  The linear motor 100 has a configuration in which a field including a permanent magnet array 14 is provided on the stator 1 side, and an armature 3 is provided on the mover 2 side. Each armature is provided by supplying any one of U-phase, V-phase, and W-phase three-phase AC power to the plurality of armature coils 24 provided in the armature 3 on the mover 2 side in an appropriate phase. The coil 24 receives a propulsive force from the permanent magnet row 14 sandwiching both axial sides thereof. Due to this propulsive force, the entire mover 2 moves relative to the stator 1 along its longitudinal direction.

<Configuration of field yoke assembly>
As shown in FIG. 3, the two yoke plates 11, the yoke fixing portion 12, and the plate 15 constitute a field yoke assembly 30. The stator 1 is assembled by fixing the permanent magnet 13 to the field yoke assembly 30 by bonding or the like. As described above, the plate 15 is a plate made of a metal different from the yoke plate 11, and a metal material having a higher thermal expansion coefficient than the yoke plate 11, for example, aluminum is used when the yoke plate 11 is made of iron. The two yoke plates 11 to which the plate 15 is fixed due to high temperature are at one end (lower side in FIG. 3 (a)) from one end (lower side in FIG. 3 (a)) to the other side (upper side in FIG. 3 (a)). It curves so as to warp outward toward the portion 11b. Thereby, the clearance gap between the two yoke plates 11 becomes larger between the other side edge part 11b than between one side edge part 11a. The gap difference is, for example, about zero comma number mm, but in FIG. 3 (a), the gap difference is greatly enlarged for easy understanding (the same applies to the following figures). As a result, the field yoke assembly 30 has a substantially U-shaped spread shape in which the shape seen from the front is widened on the open side.

  The field yoke assembly 30 after the permanent magnet 13 is attached to the yoke plate 11 is shown in FIG. The two yoke plates 11 are deformed so as to warp inward from the one end portion 11a on the fixed side to the other end portion 11b on the open side by the attractive force between the permanent magnets 13 attached to the opposing surfaces. To do. As a result, the gap between the two yoke plates 11 is not different between the other end portion 11b and the one end portion 11a, and the gap between the two yoke plates 11 is substantially constant (that is, substantially parallel).

  Various methods for fixing the plate 15 and the yoke plate 11 are conceivable. For example, the plate 15 is superposed on the yoke plate 11, and in this state, the plate 15 and the yoke plate 11 are rolled by applying high pressure with a rolling roller at a high temperature. A method is conceivable. As a result, the metal structure of the plate 15 and the metal structure of the yoke plate 11 are interatomic bonded, and the yoke plate 11 to which the plate 15 is joined is formed. The plate 15 and the yoke plate 11 may be joined by welding. Thereafter, when the yoke plate 11 to which the plate 15 is bonded is cooled to room temperature, the plate 15 having a large thermal expansion coefficient is thermally contracted at a larger rate than the yoke plate 11, so that the yoke plate 11 and the plate 15 are warped outward. Transforms into

<Effect of embodiment>
The field yoke assembly 30 of the present embodiment has plates 15 fixed to the outer sides of the two yoke plates 11 respectively. The plate 15 is made of a metal material having a higher coefficient of thermal expansion than the yoke plate 11. The field yoke assembly 30 uses the difference in thermal expansion coefficient between the yoke plate 11 and the plate 15 to deform the two yoke plates 11 to warp outward, and the gap between the two yoke plates 11 is The other side end portion 11b is configured to be larger than the one side end portion 11a where the yoke fixing portion 12 is disposed.

  In this way, by forming the field yoke assembly 30 in an expanded shape in advance, after the permanent magnet 13 is attached, the gap between the two yoke plates 11 is made substantially constant by the attractive force. be able to. Therefore, even when a strong magnet is used as the permanent magnet 13, it is possible to use the relatively thin yoke plate 11 with low rigidity, so that high output can be obtained while reducing the size and weight of the linear motor 100. Can do.

<Modification>
The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit and technical idea of the present invention. Hereinafter, such modifications will be described in order.

(1) When the yoke plate itself is processed into a warped shape in the above embodiment, a metal material plate 15 having a higher thermal expansion coefficient than the yoke plate 11 is fixed to the outside of the yoke plate 11 at a high temperature. The yoke plate 11 was deformed into a shape warped outward using the difference in coefficient of thermal expansion when cooling to room temperature, but the yoke plate 11 itself warped outward in advance by plastic working or the like. You may process into a shape. An example of the field yoke assembly of this modification is shown in FIG.

  As shown in FIG. 4A, the field yoke assembly 30A includes two yoke plates 11 and a yoke fixing portion 12 that supports one end portion 11a of the yoke plates 11 in a cantilever shape. . The two yoke plates 11 are formed in advance by machining so as to warp outward from the one end portion 11a on the fixed portion side toward the other end portion 11b on the open side.

  As shown in FIG. 4B, when the permanent magnets 13 are attached to the opposing surfaces of the two yoke plates 11, the two yoke plates 11 are fixed to the one side end by the attractive force between the permanent magnets 13. It deform | transforms so that it may warp inward toward the other side edge part 11b which is an open side from 11a. As a result, the gap between the two yoke plates 11 is not different between the other end portion 11b and the one end portion 11a, and the gap between the two yoke plates 11 is substantially constant (that is, substantially parallel).

  As the processing of the yoke plate 11, for example, bending using a rolling roller, cutting using a grinding machine, or the like can be used. For example, in bending with a rolling roller, as shown in FIG. 5A, a plurality of upper and lower rolling rollers 31 are arranged along a desired curved shape of the warp of the yoke plate 11, and the material 11A of the yoke plate 11 is moved up and down. The material 11A is plastically processed into a yoke plate 11 having a desired warpage by gradually passing between the rolling rollers 31 and extending and rolling to gradually bend. Further, for example, in the cutting process, as shown in FIG. 5B, the material 11A of the yoke plate 11 is cut by a grinding machine or the like, and the yoke plate 11 having a desired warp is cut out from the material 11A.

  In this modification, the yoke plate 11 of the field yoke assembly 30A is processed in advance into a shape warped outward. Thus, even when a strong magnet is used as the permanent magnet 13 of the field magnet 14, it is possible to use the relatively thin yoke plate 11 having low rigidity. Therefore, high output can be obtained while reducing the size and weight of the linear motor 100.

(2) When the yoke plate is supported by the yoke fixing portion in an expanded form In the above embodiment, the yoke plate 11 is warped, but the yoke plate 11 itself is a flat plate, and the yoke is fixed for support. By making the shape of the portion 12 into a substantially trapezoidal shape, the field yoke assembly may be expanded. An example of this modification is shown in FIG.

  As shown in FIG. 6A, the field yoke assembly 30B includes two flat yoke plates 11 and a yoke fixing portion 12A that supports one end portion 11a of the yoke plates 11 in a cantilever shape. It consists of. The yoke fixing portion 12A is formed in an inverted isosceles trapezoidal shape in which the cross-sectional shape in the width direction is longer in the upper base than the lower base, and has side surfaces that are inclined outward on both sides in the width direction. The two yoke plates 11 are supported by inclined side surfaces on both sides of the yoke fixing portion 12A, and are linearly expanded from the one end portion 11a supported by the yoke fixing portion 12A toward the other end portion 11b on the open side. We are open.

  As shown in FIG. 6B, when the permanent magnets 13 are attached to the opposing surfaces of the two yoke plates 11, the two yoke plates 11 are fixed to the one side end by the attractive force between the permanent magnets 13. It deform | transforms so that it may warp inside toward the other side edge part 11b which is an open side from 11a. As a result, the gap between the two yoke plates 11 is not different between the other end portion 11b and the one end portion 11a, and the gap between the two yoke plates 11 is substantially constant (that is, substantially parallel). Therefore, even when a strong magnet is used as the permanent magnet 13, it is possible to use the relatively thin yoke plate 11 with low rigidity, so that high output can be obtained while reducing the size and weight of the linear motor 100. Can do.

(3) When a plate having a low coefficient of thermal expansion is bonded to the outside of the yoke plate In the above embodiment, a plate 15 made of a metal material having a high coefficient of thermal expansion is bonded to the outside of the yoke 11, and the coefficient of thermal expansion with the plate 15 is The two yoke plates 11 warped outward due to the difference were warped inward so as to return to the original state by the attractive force of the permanent magnets 13 attached to the opposing surfaces, and the gap between the two yoke plates 11 was made constant. On the other hand, a plate made of a metal material having a low coefficient of thermal expansion is attached to the outside of the yoke 11, and the two yoke plates 11 warped inward by the attractive force between the permanent magnets attached to the opposing surface are used to drive the linear motor 100. The gap between the two yoke plates 11 may be made constant during driving by curving outward so as to return to the original due to the difference in thermal expansion coefficient with the plate at the generated heat temperature. An example of the field yoke assembly of this modification is shown in FIG.

  As shown in FIG. 7A, the field yoke assembly 30C includes two yoke plates 11, a yoke fixing portion 12 that supports one end portion 11a of the yoke plates 11 in a cantilever shape, and 2 And a dissimilar metal plate 16 fixed to the outside of one yoke plate 11.

  The plate 16 is made of a metal material having a thermal expansion coefficient smaller than that of the yoke plate 11, for example, invar when the yoke plate 11 is made of iron, and is fixed to the outside of the yoke plate 11 at room temperature (room temperature) and bonded. The As shown in FIG. 8 (b), the two yoke plates 11 to which the plate 16 is fixed are attached to the opposite surface by attaching the permanent magnet 13 to the other end portion 11a by the attractive force between the permanent magnets 13. The two yoke plates 11 are bent so as to warp inward toward the side end portion 11b, and the other end portion 11b of the two yoke plates 11 is bent inward by a predetermined amount from the one side end portion 11a.

  When the mover 2 is incorporated into the stator 1 and the linear motor 100 is assembled and the armature 3 of the mover 2 is energized, the linear motor 100 is driven and the temperature of the linear motor 100 rises. As a result, the yoke plate 11 expands at a larger rate than the plate 16 due to the difference in expansion coefficient, and the yoke plate 11 is deformed so as to warp outward, thereby canceling the bending due to the attractive force between the permanent magnets 13. As a result, as shown in FIG. 8C, the two yoke plates 11 can be returned to a substantially parallel flat plate shape.

  In this way, when the linear motor 100 is stopped (at room temperature), the magnetic gap between the field and the armature 3 is small, but when driven (at high temperature), the magnetic gap is set to a suitable gap. For example, in a linear motor that is continuously driven, the driving stability can be increased.

(4) Others In the above-described embodiments and modifications, the linear motor 100 has been described by taking as an example the case where the field is configured as a fixed part and the armature 3 is configured as a movable part. The linear motor 100 may be configured with the armature 3 as a fixed portion.

  In addition to those already described above, the methods according to the above-described embodiments and modifications may be used in appropriate combination.

  In addition, although not illustrated one by one, the present invention is implemented with various modifications within a range not departing from the gist thereof.

DESCRIPTION OF SYMBOLS 1 Stator 2 Movable element 3 Armature 11 Yoke plate 12 Yoke fixing part 12A Yoke fixing part 13 Permanent magnet 14 Permanent magnet row 15 Plate 16 Plate 30 Field yoke assembly 30A Field yoke assembly 30B Field yoke assembly 30C Field yoke assembly 100 Linear motor

Claims (7)

A field yoke assembly used in a linear motor capable of relatively moving the field and the armature, using either the field or the armature as a mover and the other as a stator,
Two yoke plates that are arranged opposite to each other and on which a plurality of the permanent magnets are attached so that the opposite permanent magnets have different polarities ;
A yoke fixing portion that supports the two yoke plates in a cantilever shape at one end of the yoke plate;
The two yoke plates are
The gap between the two yoke plates is the other than the one side end so that the gap between the two yoke plates is substantially constant due to the attractive force between the permanent magnets when the permanent magnet is attached. A field yoke assembly characterized in that the side end portion is configured to be larger. 2. The field yoke assembly according to claim 1, further comprising a plate fixed to the outside of the two yoke plates and made of a metal material different from that of the yoke plates. The yoke plate is
2. The field yoke assembly according to claim 1, wherein the field yoke assembly is machined into a shape that warps outward from the one side end toward the other side end. The yoke plate has a flat plate shape,
The yoke fixing part is
2. The two yoke plates are supported in an expanded manner such that a gap between the two yoke plates is larger at the other end than at the one end. Field yoke assembly. The plate is
3. The field yoke assembly according to claim 2 , wherein the field yoke assembly is made of a metal material having a thermal expansion coefficient larger than that of the yoke plate. The plate is
3. The field yoke assembly according to claim 2 , wherein the field yoke assembly is made of a metal material having a smaller coefficient of thermal expansion than the yoke plate. A linear motor capable of relatively moving the field and the armature, using either the field or armature as a mover and the other as a stator.
The field is
A field yoke assembly according to any one of claims 1 to 6 ;
A plurality of yokes disposed on the inner sides of two opposingly arranged yoke plates of the field yoke assembly so as to alternately have different polarities in the moving direction and different in polarity from the opposing magnets. And a permanent motor.

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