JP2013038825A - Armature of linear motor and linear motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress reduction of an effective stroke.SOLUTION: The armature disclosed in the present application comprises: an armature core equipped with main teeth; supplementary teeth provided at a stroke direction end of the armature core; and a detection part which detects a position of the armature core. In particular, the detection part is provided in a space which is more on a side of the armature core than a face which is not facing the armature core among faces facing a stroke direction of the supplementary teeth, and in a space which is more on a field part side than a face facing a field part of the supplementary teeth.

Description

  The present invention relates to a linear motor armature and a linear motor.

  Conventionally, as a kind of electric motor, a linear motor that moves a mover linearly along a stator by using attraction / repulsive force between magnetic poles is known.

  In such a linear motor, a detector such as a hall sensor may be provided on the mover as a sensor for detecting the position of the mover. Such a detection unit is provided, for example, at the end of the mover in the stroke direction (see Patent Document 1).

JP-A-8-168232

  However, if the detection unit is provided at the end of the mover in the stroke direction, there is a problem that the movable range of the mover, that is, the effective stroke is shortened by the length of the detection unit.

  The disclosed technology has been made in view of the above, and an object thereof is to provide an armature of a linear motor and a linear motor that can suppress a decrease in effective stroke.

  An armature of a linear motor disclosed in the present application is an armature of a linear motor that is disposed to face a field portion in which a plurality of magnets are arranged side by side. The armature core includes main teeth, and the armature. An auxiliary tooth provided at an end of the core in the stroke direction, and a detection unit that detects a position of the armature core, and a surface of the auxiliary tooth facing the stroke direction that is not opposed to the armature core. Is also the space on the armature core side, and the detection portion is provided in the space on the field portion side of the surface facing the field portion of the auxiliary teeth.

  Further, the linear motor disclosed in the present application is a linear motor including a field portion in which a plurality of magnets are arranged side by side, and an armature disposed to face the field portion. An armature core including a main tooth, an auxiliary tooth provided at an end of the armature core in a stroke direction, and a detection unit that detects a position of the armature core, the surface of the auxiliary tooth facing in the stroke direction. The space that is on the armature core side of the surface that does not face the armature core, and the space on the field portion side of the surface that faces the field portion of the auxiliary teeth. The detection unit is provided.

  According to one aspect of the linear motor armature and the linear motor disclosed in the present application, it is possible to suppress a decrease in effective stroke.

FIG. 1A is a schematic side view of the linear motor according to the first embodiment. FIG. 1B is a schematic plan view of the linear motor according to the first embodiment. FIG. 1C is a schematic cross-sectional view of the linear motor according to the first embodiment. FIG. 2 is a schematic side view showing the arrangement relationship between the auxiliary teeth and the magnetic field detection unit. FIG. 3 is a schematic perspective view showing the arrangement relationship between the auxiliary teeth and the magnetic field detection unit. FIG. 4 is a diagram illustrating an example of a method of attaching the magnetic field detection unit. FIG. 5 is a diagram showing an internal configuration of the magnetic field detection unit. FIG. 6A is a diagram illustrating a magnetic flux formed by permanent magnets. FIG. 6B is a diagram illustrating a detection result of the magnetic flux illustrated in FIG. 6A. FIG. 7A is a diagram illustrating a magnetic flux formed by a permanent magnet and auxiliary teeth. FIG. 7B is a diagram illustrating a detection result of the magnetic flux illustrated in FIG. 7A. FIG. 8 is a schematic perspective view showing another example of the arrangement relationship between the auxiliary teeth and the magnetic field detection unit. FIG. 9A is a schematic cross-sectional view illustrating another example of the arrangement relationship between the auxiliary teeth and the magnetic field detection unit. FIG. 9B is a schematic cross-sectional view illustrating another example of the arrangement relationship between the auxiliary teeth and the magnetic field detection unit.

  Exemplary embodiments of a linear motor armature and a linear motor disclosed in the present application will be described below in detail with reference to the accompanying drawings. However, the present invention is not limited to the examples in these examples.

  First, the overall configuration of the linear motor according to the present embodiment will be described with reference to FIGS. 1A to 1C. 1A to 1C are a schematic side view, a schematic plan view, and a schematic cross-sectional view, respectively, of a linear motor according to a first embodiment. 1B is a schematic plan view when the linear motor shown in FIG. 1A is viewed from the positive Z-axis direction. 1C is a schematic cross-sectional view taken along line A-A ′ shown in FIG. 1A.

  In the following, in explaining the relative positional relationship of each component of the linear motor, there are cases where directions are indicated in the vertical direction, the horizontal direction, and the longitudinal direction. The reference for each direction is as shown in FIG. 1A. Suppose that the linear motor is installed on a horizontal plane. Specifically, in FIG. 1A, the positive and negative directions of the X axis are the front and rear of the linear motor, respectively, the positive and negative directions of the Y axis are the left and right directions of the linear motor, and the positive direction of the Z axis, respectively. The negative direction is defined above and below the linear motor.

  As shown in FIGS. 1A to 1C, the linear motor 1 according to this embodiment includes a field magnet portion 10 and an armature 20. In this embodiment, the case where the field unit 10 is a stator and the armature 20 is a mover will be described. Further, the number of magnetic poles and the number of slots are not limited to those shown in FIGS. 1A to 1C.

  The field unit 10 includes a field yoke 11 and a permanent magnet 12. The field yoke 11 is a substantially rectangular parallelepiped member extending along a predetermined direction (here, the X-axis direction). For example, the field yoke 11 is formed by laminating a plurality of thin plate materials such as electromagnetic steel plates, or is simply not laminated. It is made of a plate material. The permanent magnets 12 are arranged side by side on the field yoke 11. In addition, although the case where the field part 10 is provided with the permanent magnet 12 is demonstrated here, the field part 10 may be provided with an electromagnet instead of the permanent magnet 12.

  The armature 20 is a member that is disposed to face the field portion 10 via a gap, and moves linearly along the field portion 10. The armature 20 includes an armature core 21, an armature winding 22, auxiliary teeth 23 a and 23 b, a mold resin 24, and a magnetic field detection unit 25. Hereinafter, the moving direction of the armature 20, that is, the positive direction and the negative direction of the X axis may be referred to as a stroke direction.

  The armature core 21 includes a yoke 21a formed in a substantially rectangular parallelepiped shape and a plurality of main teeth 21b protruding from the yoke 21a toward the field magnet portion 10. The armature core 21 is formed by laminating a plurality of thin plate materials such as electromagnetic steel plates.

  The space between the main teeth 21b is called a slot 21c. The inner peripheral surface of the slot 21c is covered with an insulating material or the like, and the armature winding 22 wound using an insulation-coated electric wire is accommodated in the slot 21c. A motor lead wire 26 is connected to each armature winding 22 (see FIG. 1B).

  The auxiliary teeth 23a and 23b are members provided at both ends of the armature core 21 in the stroke direction in order to reduce cogging which causes a thrust fluctuation. Specifically, the auxiliary teeth 23 a and 23 b have ends fixed to the yoke 21 a and project from the ends toward the field portion 10.

  Here, as shown to FIG. 1A, the space | interval between the permanent magnet 12 and the auxiliary teeth 23a and 23b is larger than the space | interval between the permanent magnet 12 and the main teeth 21b. That is, the auxiliary teeth 23a and 23b are formed so that the length in the vertical direction is shorter than that of the main teeth 21b. Therefore, the armature 20 has an end face (that is, a lower end face of the auxiliary teeth 23a and 23b) facing the field portion 10 of the auxiliary teeth 23a and 23b and an end face (ie, the end face of the main teeth 21b facing the field portion 10 (that is, , A surplus space where none of the main teeth 21b, the armature windings 22 and the auxiliary teeth 23a are arranged exists.

  The mold resin 24 is a resin member that molds the armature core 21, the armature winding 22, and the auxiliary teeth 23a and 23b. As shown in FIGS. 1B and 1C, the mold resin 24 covers the auxiliary teeth 23a so that at least a part of the lower end surface of the auxiliary teeth 23a is exposed. A magnetic field detection unit 25 is attached to the end surface of the auxiliary tooth 23a exposed from the mold resin 24. This point will be described later with reference to FIG.

  The magnetic field detection unit 25 is a unit member that includes a detection unit that detects the relative position of the armature 20 with respect to the field unit 10. In this embodiment, the detection unit is a magnetic field detection unit such as a hall sensor. In the linear motor 1, the energization direction to the armature winding 22 is controlled based on the detection result of the relative position of the armature 20 by the magnetic field detection unit 25. The magnetic field detection unit 25 is connected with a detection portion lead 27 (see FIG. 1B).

  Here, the linear motor 1 according to the present embodiment provides the magnetic field detection unit 25 to the surplus space existing between the lower end surface of the auxiliary teeth 23a and the lower end surface of the main teeth 21b, so that the armature 20 The reduction in effective stroke is to be suppressed.

  Below, the arrangement | positioning relationship between the auxiliary | assistant teeth 23a and the magnetic field detection unit 25 is concretely demonstrated using FIG. 2 and FIG. FIG. 2 is a schematic side view showing the arrangement relationship between the auxiliary teeth 23 a and the magnetic field detection unit 25. FIG. 3 is a schematic perspective view showing the arrangement relationship between the auxiliary teeth and the magnetic field detection unit.

  As shown in FIG. 2, the magnetic field detection unit 25 is a space (a1 to a2 space) from one end surface facing the stroke direction of the auxiliary teeth 23a to the other end surface when viewed from the Y axis positive direction. And it is provided with respect to the space (space of b1-b2) from the surface facing the field part 10 of the auxiliary teeth 23a to the surface facing the field part 10 of the main teeth 21b.

  Here, the conventional armature has a problem that the effective stroke is shortened by the length of the detection unit by providing the detection unit at the end in the stroke direction. In particular, such a problem is easily manifested when an auxiliary tooth is provided at the end of the armature core in the stroke direction as in this embodiment.

  For this reason, in the present Example, the magnetic field detection unit 25 was provided with respect to the surplus space which exists between the lower end surface of the auxiliary teeth 23a and 23b and the lower end surface of the main teeth 21b. Thereby, since the length which members other than the armature core 21 occupy among the lengths of the armature 20 in the stroke direction can be suppressed, it is possible to suppress the decrease in the effective stroke while maintaining the thrust of the armature 20. it can.

  In addition, although the example in the case where the magnetic field detection unit 25 fits in the space (space of a1-a2) from the one end surface which faces the stroke direction of the auxiliary teeth 23a to the other end surface is shown, the magnetic field detection unit 25 is shown. May partially protrude from this range.

  Further, as shown in FIG. 3, the magnetic field detection unit 25 is provided so that the detection unit provided therein is positioned in the space 50a on the right side of the auxiliary tooth 23a in the above space, Of these, a portion located in a space below the auxiliary teeth 23a (a space 50c shown in FIG. 8) is attached to the auxiliary teeth 23a.

  Here, a method for attaching the magnetic field detection unit 25 to the auxiliary teeth 23a and an internal configuration of the magnetic field detection unit 25 will be described with reference to FIGS. FIG. 4 is a diagram illustrating an example of a method for attaching the magnetic field detection unit 25, and FIG. 5 is a diagram illustrating an internal configuration of the magnetic field detection unit 25.

  For example, as shown in FIG. 4, screw holes 231 are formed in the auxiliary teeth 23 a along the positive Z-axis direction from the lower end surface exposed from the mold resin 24. A similar screw hole 251 is also formed in a portion of the magnetic field detection unit 25 located below the auxiliary teeth 23a. And as shown in FIG. 5, the magnetic field detection unit 25 is attached with respect to the auxiliary | assistant teeth 23a by inserting the screw 60 in the screw hole 231 of the auxiliary | assistant teeth 23a, and the screw hole 251 of the magnetic field detection unit 25. As shown in FIG.

  As described above, if the magnetic field detection unit 25 is detachably provided to the molded armature core 21 and the auxiliary teeth 23a, for example, when the magnetic field detection unit 25 deteriorates or breaks down, the magnetic field The detection unit 25 can be easily replaced, and the maintainability of the armature 20 can be improved.

  Moreover, as shown in FIG. 5, the detection part 252 in the magnetic field detection unit 25 is provided so as to be located on the right side of the auxiliary teeth 23a. Specifically, the detection unit 252 receives the auxiliary teeth 23a from the auxiliary teeth 23a in a direction (Y-axis direction) perpendicular to the direction (Z-axis direction) and the stroke direction (X-axis direction) in which the auxiliary teeth 23a face the field magnet unit 10. Is also provided outside.

  In this manner, by providing the detection unit 252 outside the auxiliary teeth 23a, it is possible to appropriately suppress instability of the magnetic field detection accuracy by the detection unit 252.

  That is, when the detection unit 252 is partially located below the auxiliary tooth 23a, the detection unit 252 may be partially affected by the auxiliary tooth 23a, and the detection accuracy of the magnetic field by the detection unit 252 may become unstable. Although it is conceivable that all of the detection unit 252 is positioned below the auxiliary teeth 23a, the detection unit 252 has a space from one end surface facing the stroke direction of the auxiliary teeth 23a to the other end surface (a1 to a2 shown in FIG. 2). In such a case, the detection unit 252 is partially located below the auxiliary teeth 23a.

  Therefore, by providing the detection unit 252 outside the auxiliary teeth 23a, it is possible to appropriately suppress instability of the magnetic field detection accuracy by the detection unit 252.

  In the present embodiment, as shown in FIG. 1C, the permanent magnet 12 is extended to a position facing the detection unit 252. That is, since the permanent magnet 12 is usually disposed below the auxiliary teeth 23a, if the detection unit 252 is provided outside the auxiliary teeth 23a, the detection unit 252 is far from the permanent magnet 12 and the detection accuracy is reduced. There is a risk.

  Therefore, by extending the permanent magnet 12 to a position facing the detection unit 252, it is possible to prevent such a decrease in detection accuracy. However, the permanent magnet 12 may not be extended.

  Further, the armature 20 according to the present embodiment can increase the accuracy of magnetic field detection by the detection unit 252 by providing the detection unit 252 in the vicinity of the auxiliary teeth 23a. This point will be described with reference to FIGS. 6A to 7B.

  FIG. 6A is a diagram showing a magnetic flux formed by the permanent magnets 12, and FIG. 7A is a diagram showing a magnetic flux formed by the permanent magnet 12 and the auxiliary teeth 23a. 6B is a diagram showing the detection result of the magnetic flux shown in FIG. 6A, and FIG. 7B is a diagram showing the detection result of the magnetic flux shown in FIG. 7A. In FIG. 7B, the detection result in the case of FIG. 7A is indicated by a solid line, and the detection result in FIG. 6B is indicated by a dotted line. The moving speed of the armature 20 on the solid line and the dotted line is the same.

  As shown in FIG. 6A, the magnetic flux M formed by the permanent magnets 12 draws a constant parabola from one permanent magnet 12 (N pole) to the other permanent magnet 12 (S pole). The detection result when the detection unit 252 detects the magnetic flux M has a relatively gentle rise as shown in FIG. 6B (see t1 in FIG. 6B).

  On the other hand, as shown in FIG. 7A, when the auxiliary teeth 23a exist in the vicinity of the permanent magnet 12, the magnetic flux M from the permanent magnets 12 is absorbed by the auxiliary teeth 23a. For this reason, the magnetic flux density in the vicinity of the auxiliary teeth 23a is higher than the magnetic flux density in the case shown in FIG. 6A.

  The detection unit 252 which is a magnetic field detection unit outputs an output voltage proportional to the magnetic flux density as a detection result. Therefore, as shown in FIG. 7B, the detection result of the magnetic field by the detection unit 252 has a rapid rise compared to the case shown in FIG. 6B. That is, as shown in FIG. 7B, the time difference from when the detection unit 252 passes the magnetic pole to when the detection unit 252 outputs the detection result is larger than when the auxiliary teeth 23a are not present near the permanent magnet 12. The case where the tooth 23a exists in the vicinity of the permanent magnet 12 is shorter (see t1 and t2 in FIG. 7B).

  Therefore, by providing the detection unit 252 of the magnetic field detection unit 25 in the vicinity of the auxiliary teeth 23a, the time difference is shortened, and the detection accuracy of the magnetic field by the detection unit 252 can be increased.

  As described above, in this embodiment, the space from the one end surface facing the stroke direction of the auxiliary teeth to the other end surface, and the field portion of the main teeth from the surface facing the field portion of the auxiliary teeth. The detection unit is provided in the space up to the opposing surface. Therefore, it is possible to suppress a decrease in the effective stroke of the armature.

  Further, in this embodiment, the detection unit is provided outside the auxiliary teeth in the direction perpendicular to the stroke direction and the direction in which the auxiliary teeth face the magnetic field unit. Destabilization can be appropriately suppressed.

  The space in which the detection unit is provided is not limited to the case described in the present embodiment. Specifically, the space in which a part or all of the detection unit is provided is a space closer to the armature core than the surface that does not face the armature core among the surfaces facing the stroke direction of the auxiliary teeth (from a1 shown in FIG. 2). And the space on the field portion side of the surface facing the field portion of the auxiliary teeth (the space on the field portion side than b1 shown in FIG. 2). . Therefore, the detection unit may be provided between the auxiliary teeth and the field unit as viewed from the Y direction in FIG.

  In this embodiment, the magnetic field detection unit is provided in the space on the right side of the auxiliary teeth (the space 50a shown in FIG. 3), but the space on the left side of the auxiliary teeth (the space 50b shown in FIG. 3). A magnetic field detection unit may be provided.

  Incidentally, the arrangement relationship between the auxiliary teeth and the magnetic field detection unit is not limited to the case shown in the first embodiment. Therefore, in the second embodiment, another example of the arrangement relationship between the auxiliary teeth and the magnetic field detection unit will be described.

  FIG. 8 is a schematic perspective view showing another example of the arrangement relationship between the auxiliary teeth and the magnetic field detection unit. In the following description, parts that are the same as those already described are given the same reference numerals as those already described, and redundant descriptions are omitted.

  As shown in FIG. 8, the magnetic field detection unit 25a according to the second embodiment also has a surplus between the lower end surface of the auxiliary teeth 23a and the lower end surface of the main teeth 21b, similarly to the magnetic field detection unit 25 according to the first embodiment. Provided for space.

  Specifically, the magnetic field detection unit 25a is a space (a1 to a2 space) from one end surface facing the stroke direction of the auxiliary teeth 23a to the other end surface, and is opposed to the field portion 10 of the auxiliary teeth 23a. To a space (b1 to b2 space) from the surface to face to the surface facing the field portion 10 of the main teeth 21b.

  And the magnetic field detection unit 25a which concerns on Example 2 is provided so that it may be located in the space 50c below the auxiliary teeth 23a among said space.

  Thus, the magnetic field detection unit 25a may be provided inside the auxiliary teeth 23a in a direction orthogonal to the direction in which the auxiliary teeth 23a face the field magnet portion 10 and the stroke direction.

  In particular, when the magnetic field detection unit 25a fits in a space from the one end surface facing the stroke direction of the auxiliary teeth 23a to the other end surface (a1 to a2 space), the detection unit 252 is provided even if provided in the space 50c. There is no possibility that the detection accuracy of the magnetic field by becomes unstable.

  The magnetic field detection unit 25a according to the second embodiment is also detachably provided to the molded armature core 21 and the auxiliary teeth 23a, similarly to the magnetic field detection unit 25 according to the first embodiment.

  In each of the above-described embodiments, the case where the magnetic field detection unit is detachably provided to the molded armature core 21 and the auxiliary teeth 23a has been described. However, the present invention is not limited to this. That is, the magnetic field detection unit may be molded together with the armature core 21 and the auxiliary teeth 23a. Hereinafter, this point will be described with reference to FIGS. 9A and 9B. 9A and 9B are schematic cross-sectional views illustrating another example of the arrangement relationship between the auxiliary teeth and the magnetic field detection unit.

  As shown in FIGS. 9A and 9B, the magnetic field detection units 25b and 25c may be provided in a state where they are not in contact with the auxiliary teeth 23a, specifically, in a state where they are floated in the mold resin 24. 9A shows an example where the magnetic field detection unit 25b is provided on the right side of the auxiliary teeth 23a, and FIG. 9B shows an example where the magnetic field detection unit 25c is provided below the auxiliary teeth 23a. ing.

  In each of the embodiments described above, an example in which the detection unit is a magnetic field detection unit has been described. However, the detection unit may be a detection unit other than the magnetic field detection unit. For example, an infrared sensor or the like that detects the relative position of the armature core by performing predetermined marking on the surface of the permanent magnet facing the armature and optically detecting the marking may be provided as the detection unit. .

  Moreover, in each Example mentioned above, although the example in case an auxiliary | assistant tooth | gear was integrally formed with an armature core was demonstrated, it is not restricted to this, An auxiliary | assistant tooth | gear is separate from an armature core. It may be formed.

  In each of the embodiments described above, the magnetic field detection unit 25 is used. However, only the detection unit may be used.

  Further effects and modifications can be easily derived by those skilled in the art. Thus, the broader aspects of the present invention are not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications can be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

DESCRIPTION OF SYMBOLS 1 Linear motor 10 Field part 11 Field yoke 12 Permanent magnet 20 Armature 21 Armature core 21a Yoke 21b Main teeth 21c Slot 22 Armature winding 23a, 23b Auxiliary teeth 24 Mold resin 25 Magnetic field detection unit 251 Screw hole 252 detection 26 Lead wire for motor 27 Lead wire for detector

Claims (6)

An armature of a linear motor disposed opposite to a field portion in which a plurality of magnets are arranged side by side,
An armature core with main teeth;
Auxiliary teeth provided at the stroke direction end of the armature core;
A detection unit for detecting the position of the armature core,
Of the surface facing the stroke direction of the auxiliary teeth, the space is closer to the armature core than the surface not facing the armature core, and more than the surface facing the field portion of the auxiliary teeth. An armature of a linear motor, characterized in that the detection unit is provided in a space on the field side. The detector is
2. The armature for a linear motor according to claim 1, wherein the auxiliary teeth are provided outside the auxiliary teeth in a direction perpendicular to the stroke direction and the direction facing the field portion. The detector is
2. The armature for a linear motor according to claim 1, wherein the auxiliary teeth are provided inside the auxiliary teeth in a direction orthogonal to the stroke direction and a direction facing the field portion.   The linear motor armature according to claim 1, 2 or 3, wherein the detection unit is detachably provided to the molded armature core and the auxiliary teeth. A linear motor comprising a field part in which a plurality of magnets are arranged side by side, and an armature disposed to face the field part,
The armature is
An armature core with main teeth;
Auxiliary teeth provided at the stroke direction end of the armature core;
A detection unit for detecting the position of the armature core,
Of the surface facing the stroke direction of the auxiliary teeth, the space is closer to the armature core than the surface not facing the armature core, and more than the surface facing the field portion of the auxiliary teeth. A linear motor characterized in that the detection unit is provided in a space on the field side. The detector is
The auxiliary teeth are provided outside the auxiliary teeth in a direction perpendicular to the stroke direction and the direction facing the field portion;
The field part is
The linear motor according to claim 5, wherein the magnet extends to a position facing the detection unit.

Images