JP5403007B2 - Linear motor armature and linear motor - Google Patents

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 includes an armature core having a main tooth, a notched auxiliary tooth provided at a stroke direction end of the armature core, and a detection for detecting a position of the armature core. And a mold resin that molds the auxiliary teeth in a state in which the end surface where the auxiliary teeth are cut out is exposed, and the detection unit is provided in a space where the auxiliary teeth are cut out. It attaches to the end surface exposed from the mold resin 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 main teeth, a notched auxiliary tooth provided at an end in a stroke direction of the armature core, a detection unit for detecting a position of the armature core, and at least the notch of the auxiliary tooth. A mold resin that molds the auxiliary teeth with the end face exposed, and the detection unit is provided in a space in which the auxiliary teeth are cut out, and is exposed from the mold resin of the auxiliary teeth. Attached to the end face .

  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. 2A is a schematic front view illustrating an arrangement relationship between auxiliary teeth and detection units. FIG. 2B is a schematic plan view showing an arrangement relationship between auxiliary teeth and detection units. FIG. 2C is a schematic perspective view illustrating an arrangement relationship between auxiliary teeth and detection units. FIG. 3A is a diagram illustrating an example of a method of attaching the detection unit. FIG. 3B is a diagram illustrating another example of a method of attaching the detection unit. FIG. 4 is a schematic perspective view illustrating another example of the arrangement relationship between the auxiliary teeth and the detection unit. FIG. 5 is a schematic perspective view illustrating another example of the arrangement relationship between the auxiliary teeth and the detection unit. FIG. 6A is a schematic perspective view illustrating another example of the arrangement relationship between the auxiliary teeth and the detection unit. FIG. 6B is a schematic perspective view illustrating another example of the arrangement relationship between the auxiliary teeth and the detection unit. FIG. 6C is a schematic perspective view illustrating another example of the arrangement relationship between the auxiliary teeth and the 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 23a and 23b, a mold resin 24, and a detection unit 25. In the following, the moving direction of the armature 20, that is, the positive direction and the negative direction of the X axis will be referred to as the 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.

  In this embodiment, as shown in FIG. 1A, when the interval between the permanent magnet 12 and the auxiliary teeth 23a, 23b is larger than the interval between the permanent magnet 12 and the main teeth 21b, that is, the auxiliary teeth 23a, 23b. Shows an example in which is shorter than the main teeth 21b. However, the length of the auxiliary teeth 23a and 23b may be equal to that of the main teeth 21b.

  Here, as for the armature 20 which concerns on a present Example, some auxiliary teeth 23a and 23b are notched. The armature 20 according to the present embodiment is configured to suppress the reduction of the effective stroke by providing the detection unit 25 in the space where the auxiliary teeth 23a and 23b are cut out. This will be specifically described with reference to FIGS. 2A to 2C.

  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 end surfaces of the auxiliary teeth 23a facing the negative Y-axis direction and the end surfaces of the yoke 21a facing the positive X-axis direction, respectively. In addition, the detection part 25 is attached to the end surface exposed from the mold resin 24 of the auxiliary teeth 23a. This point will be described later with reference to FIG. 3A.

  The detection unit 25 is a detection unit that detects the relative position of the armature 20 with respect to the field unit 10. In the present embodiment, the detection unit 25 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 detection unit 25. Note that the detection unit lead wire 27 is connected to the detection unit 25 (see FIG. 1B).

  Such a detection unit 25 is provided in the space where the auxiliary teeth 23a are notched in FIG. 1B. Thereby, the linear motor 1 which concerns on a present Example can suppress reduction of the effective stroke of the armature 20. FIG.

  In the example shown in FIG. 1B, the detection unit 25 is provided in the space where the auxiliary teeth 23a are cut out, but the arrangement of the detection unit 25 is not limited to this. That is, a part of the detection unit 25 may be provided outside the space where the auxiliary teeth 23a are notched. For example, a part of the detection unit 25 may protrude in the negative direction of the X direction in FIG. 1B. Even in this case, since the detection unit 25 can be provided in the space where the auxiliary teeth 23a are notched, reduction of the effective stroke of the armature 20 can be suppressed.

  Below, the arrangement | positioning relationship between the auxiliary teeth 23a and the detection part 25 is concretely demonstrated using FIG. 2A-FIG. 2C. 2A to 2C are a schematic front view, a schematic plan view, and a schematic perspective view showing the arrangement relationship between the auxiliary teeth 23a and the detection unit 25, respectively.

  As shown in FIGS. 2A to 2C, the auxiliary teeth 23 a are notched so as to reach from one end surface to the other end surface in the stroke direction, that is, from one end surface on the X axis negative direction side to the other end surface on the X axis positive direction side. The cutout portion 100a is provided.

  The notch 100a includes a side s1 (Z-axis negative direction side) facing the field part 10, a side s2 (Y-axis positive direction side) adjacent to the side s1 facing the field part 10, and the field part 10. Opposite side s1 opposite side s3 (Z-axis positive direction side) is opened. That is, the auxiliary teeth 23a have a shape in which the left half is cut away when viewed from the positive X-axis direction. The detection part 25 is provided with respect to the notch part 100a of the auxiliary teeth 23a.

  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.

  Therefore, in this embodiment, the detection unit 25 is provided in the space where the auxiliary teeth 23a are notched. 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, the reduction of the effective stroke can be suppressed while maintaining the thrust of the armature 20. it can.

  Further, in the present embodiment, the notch portion 100a is open on the side facing the field portion 10. Moreover, the whole detection part 25 is provided in the notch part 100a. For this reason, the detection accuracy of the magnetic field by the detection unit 25 is unlikely to decrease.

  Further, in this embodiment, the auxiliary teeth 23a and 23b have the same shape as shown in FIG. 1B and are symmetrical with respect to the center of the armature core 21 when viewed from the Z-axis direction. Has been placed. For this reason, even if it is a case where some auxiliary teeth 23a and 23b are notched, cogging can be reduced with good balance.

  Further, the auxiliary teeth 23a and 23b are not only cut out, but the length, thickness, and the like are optimized according to the cut out shape so that the effect of reducing cogging is not reduced as much as possible. For this reason, the installation space of the detection part 25 can be ensured, maintaining the effect of cogging reduction as much as possible.

  In addition, the detection part 25 may be provided in the position away from the auxiliary teeth 23a. Thereby, since the detection part 25 becomes difficult to receive to the influence of the auxiliary teeth 23a, the detection accuracy of the detection part 25 improves.

  In the present embodiment, the detection unit 25 is a magnetic field detection unit, but the detection unit may be a detection unit other than the magnetic field detection unit. For example, a predetermined marking is applied to the surface of the permanent magnet 12 facing the armature 20, and an infrared sensor or the like that detects the relative position of the armature core 21 by optically detecting the marking is provided as a detection unit. May be.

  Next, the attachment direction of the detection unit 25 will be described with reference to FIG. 3A. FIG. 3A is a diagram illustrating an example of a method for attaching the detection unit 25.

  The detection unit 25 according to the present embodiment is unitized, and the detection unit 25 is detachably provided on the auxiliary teeth 23a and 23b molded by the mold resin 24.

  For example, as shown in FIG. 3A, screw holes 231 are formed in the auxiliary teeth 23a along the negative Y-axis direction from the end surface exposed from the mold resin 24. A similar screw hole 251 is also formed in the detection unit 25. And the detection part 25 can be attached with respect to the auxiliary | assistant teeth 23a by inserting the screw which is not shown in figure into the screw hole 231 of the auxiliary | assistant teeth 23a, and the screw hole 251 of the detection part 25. FIG.

  As described above, if the detection unit 25 is detachably provided, the detection unit 25 can be easily replaced, for example, when the detection unit 25 deteriorates or breaks down. Can be improved.

  The notch 100a (see FIG. 2A) of the auxiliary teeth 23a is opposed not only to the side s1 facing the field part 10, but also to the side s2 adjacent to the field s1 and the field part 10. The side s3 opposite to the side s1 is also open. For this reason, the attaching / detaching operation of the detection unit 25 can be easily performed.

  Moreover, as shown to FIG. 3A, the detection part 25 is provided in the position close | similar to the field magnet part 10 among the auxiliary teeth 23a. Thereby, the detection accuracy of the magnetic field by the detection part 25 can be improved.

  In FIG. 3A, the detection unit 25 is provided on the auxiliary teeth 23a, but the method of attaching the detection unit 25 is not limited to this. FIG. 3B is a diagram illustrating another example of a method for attaching the detection unit 25.

  As shown in FIG. 3B, the detection unit 25 may be provided in the yoke 21a, for example. In such a case, a screw hole 212 is formed along the positive direction of the X axis from the end surface of the yoke 21a exposed from the mold resin 24, and not shown in both the screw hole 212 of the yoke 21a and the screw hole 251 of the detection unit 25. What is necessary is just to let a screw pass.

  Note that the detection unit 25 may be provided in a state of floating in the mold resin 24.

  As described above, in the present embodiment, since the detection unit 25 is provided in the space where the auxiliary teeth 23a are notched, reduction of the effective stroke can be suppressed.

  By the way, the method of notching the auxiliary teeth and the arrangement of the detection units are not limited to those shown in the first embodiment. Accordingly, in the second embodiment, another example of how to cut out the auxiliary teeth and the arrangement of the detection units will be described.

  4 and 5 are schematic perspective views illustrating another example of the arrangement relationship between the auxiliary teeth and the 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 illustrated in FIG. 4, the armature 20a includes an auxiliary tooth 23a_1 instead of the auxiliary tooth 23a according to the first embodiment.

  The auxiliary tooth 23a_1 includes a notch 100b. The notch 100b is the same as the notch 100a according to the first embodiment, from one end surface to the other end surface in the stroke direction of the auxiliary teeth 23a_1, that is, the other end surface on the X axis negative direction side to the other end surface on the X axis negative direction side. Notched to reach up to.

  The notch 100b is open on the side facing the field part 10 (Z-axis negative direction side) and on the opposite side of the side facing the field part 10 (Z-axis positive direction side). In this way, the auxiliary teeth 23a_1 may have a shape in which the middle portion is vertically cut when viewed from the positive direction of the X-axis.

  In such a case, the auxiliary teeth 23a_1 and the yoke 21a are molded with a mold resin (not shown) so that the end surface of the auxiliary teeth 23a_1 facing the notch 100b and the end surface of the yoke 21a in the stroke direction are exposed. And the detection part 25 is detachably attached to the end surface of the auxiliary teeth 23a_1 or the yoke 21a exposed from the mold resin (not shown), as in the first embodiment.

  Although not shown, the armature 20a includes auxiliary teeth having the same shape as the auxiliary teeth 23a_1 instead of the auxiliary teeth 23b according to the first embodiment. Similar to the first embodiment, these auxiliary teeth are arranged symmetrically with respect to the center of the armature core 21 when viewed from the Z-axis direction. Thereby, cogging can be reduced with good balance.

  Moreover, as shown in FIG. 5, the armature 20b is good also as noting all the auxiliary teeth provided in the stroke direction both ends of the armature core 21, and providing the detection part 25 in the notched space. .

  In addition, although illustration is abbreviate | omitted, the auxiliary | assistant tooth provided in the X-axis positive direction side becomes a shape which is not cut out. Specifically, the auxiliary teeth provided on the X-axis negative direction side have a substantially rectangular parallelepiped shape whose width in the Y-axis direction is substantially the same as that of the main teeth 21b.

  4 and 5, the detection unit 25 may be provided in a state of floating in the mold resin 24.

  Further, another example of the arrangement relationship between the auxiliary teeth and the detection unit will be further described with reference to FIGS. 6A to 6C. 6A to 6C are schematic perspective views illustrating another example of the arrangement relationship between the auxiliary teeth and the detection unit.

  As shown in FIG. 6A, the auxiliary teeth 23a_2 included in the armature 20c include a through hole that penetrates from one end surface to the other end surface in the stroke direction as the notch portion 100c. Thus, the notch 100c may be a through hole that is not open on either side in the Z-axis direction or the Y-axis direction. The detection unit 25 is provided in the notch 100c.

  Moreover, as shown to FIG. 6B, the auxiliary teeth 23a_3 with which the armature 20d is provided are provided with the notch part 100d. The notch 100d is notched so as to reach from the one end surface to the other end surface in the stroke direction, and the side facing the field portion 10 (Z-axis negative direction side) is open. As described above, the cutout portion 100d may have a shape in which only the side facing the field portion 10 is opened. The detection unit 25 is provided in the notch 100d.

  Moreover, as shown to FIG. 6C, the auxiliary teeth 23a_4 with which the armature 20e is provided are provided with the notch part 100e. The notch 100e is notched so as to reach from the one end surface to the other end surface in the stroke direction, and is adjacent to the side facing the field portion 10 (Z-axis negative direction side) and the side facing the field portion 10. Only the side (Y-axis positive direction side) is opened. As described above, the cutout portion 100e may have a shape in which only the side facing the field portion 10 and the side adjacent to the side facing the field portion 10 are opened. The detection unit 25 is provided in the notch 100e.

  In each of the embodiments described above, an example in which the auxiliary teeth are formed integrally with the armature core has been described. However, the present invention is not limited to this, and the auxiliary teeth are separated from the armature core. It may be formed.

  In each of the embodiments described above, the detection unit 25 is used, but a magnetic field detection unit that is a unit member including the detection unit 25 may be used instead of the detection unit 25.

  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 Detection part 26 Motor lead wire 27 Detection unit lead wires 100a to 100e Notch

Claims (9)

An armature core with main teeth;
A cut-out auxiliary teeth provided to the stroke direction end of the armature core,
A detection unit for detecting the position of the armature core ;
A mold resin that molds the auxiliary teeth in a state where at least the cut end face of the auxiliary teeth is exposed ;
The linear motor armature according to claim 1, wherein the detection unit is provided in a space in which the auxiliary teeth are notched and is attached to an end surface of the auxiliary teeth exposed from the mold resin . The auxiliary teeth are
2. The armature for a linear motor according to claim 1, further comprising a cutout portion cut out so as to reach from the one end surface to the other end surface in the stroke direction. The notch is
The armature of the linear motor according to claim 2, wherein a side facing a field portion where a plurality of magnets are arranged side by side is opened. The notch is
4. The armature for a linear motor according to claim 3, wherein one of the sides adjacent to the side facing the field part is further opened. The notch is
The armature of the linear motor according to claim 3 or 4, wherein the side opposite to the side facing the field part is further opened. The auxiliary teeth are
6. The armature cores are respectively provided at both ends in the stroke direction, have the same shape, and are arranged point-symmetrically with respect to the center of the armature core. The armature of the linear motor as described in any one of. The auxiliary teeth are
Provided at both ends of the armature core in the stroke direction,
2. The armature for a linear motor according to claim 1, wherein any one of the auxiliary teeth is cut away. Prior Symbol detector, linear motor armature according to any one of claims 1 to 7, characterized in that it is detachably attached to the end face exposed from the mold resin of 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;
A cut-out auxiliary teeth provided to the stroke direction end of the armature core,
A detection unit for detecting the position of the armature core ;
A mold resin that molds the auxiliary teeth in a state where at least the end surface of the auxiliary teeth cut out is exposed ;
The linear motor is characterized in that the detection unit is provided in a space where the auxiliary teeth are notched and is attached to an end surface of the auxiliary teeth exposed from the mold resin .

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