JP7229526B2 - Embedded magnet type motor, position estimation device and position estimation method - Google Patents

Description

The present invention relates to an embedded magnet motor, a position estimation device and a position estimation method.

In recent years, linear and rotatable two-degree-of-freedom motors have been proposed. For example, the electromagnetic actuator described in Patent Document 1 constitutes a driving mechanism using, as driving force, the resultant force of two magnetomotive forces generated by crossed conductors. This electromagnetic actuator changes the direction of the resultant force of two magnetomotive forces (Lorentz force) by adjusting the direction of the current flowing through the crossed conductors, and independently controls different driving modes.

JP 2015-163004 A

By the way, the electromagnetic actuator described in Patent Document 1 is a motor of a surface magnet type or a type called SPM (Surface Permanent Magnet) in which a magnet is attached to the surface of a shaft that is a mover. SPM type motors are not suitable for high-speed rotation because the magnets attached to the surface tend to peel off. Therefore, the inventors considered changing the electromagnetic actuator described in Patent Document 1 to an embedded magnet type or a type called IPM (Interior Permanent Magnet). In the embedded magnet type motor or IPM type motor, the magnets are embedded in the shaft, so there is no fear that the magnets will come off due to high-speed rotation.

However, when the magnetic pole portion of the electromagnetic actuator described in Patent Document 1 is changed to the IPM type, for example, if magnets with different polarities are inserted side by side in the space provided in the axial direction of the shaft, the N pole and S pole will be short-circuited, and the magnetic flux decreases. When arranging a plurality of magnets by such a method, it is difficult to assemble them with high accuracy.

SUMMARY OF THE INVENTION The present invention has been made to solve such problems, and provides a two-degree-of-freedom embedded magnet motor or the like that is easy to assemble and that can rotate at high speed.

An embedded magnet type motor according to the present invention comprises: a first winding body including a first conductor wire extending in a first spiral direction about a reference axis; and a second winding body including a second conductor wire extending in a second spiral direction centered on, and facing at least a part of the stator in a radial direction orthogonal to the reference axis, the fixed a mover that is relatively movable in an axial direction along the reference axis and relatively rotatable in a circumferential direction about the reference axis with respect to the element; a first magnet group in which magnetic poles different in the circumferential direction are alternately arranged; a second magnet group arranged downstream of the first magnet group in the axial direction and in which magnetic poles different in the circumferential direction are alternately arranged; A first magnet holding portion that holds the first magnet group so that the first magnet group is embedded and has a magnetic permeability higher than that of air, and a second magnet group so that the second magnet group is embedded. a second magnet holding portion having a magnetic permeability higher than that of air; a magnetic flux barrier portion disposed between the first magnet group and the second magnet group and having a magnetic permeability lower than that of the first magnet holding portion and the second magnet holding portion.

With such a configuration, the electromagnetic actuator has the IPM-type magnetic pole portions connected in the axial direction. Therefore, the electromagnetic actuator has a configuration that is easy to assemble.

In the embedded magnet type motor, it is preferable that the magnetic flux barrier section is formed in a cylindrical shape. This facilitates processing of the magnetic flux barrier portion.

In the above-described embedded magnet type motor, the magnetic flux barrier section has a first magnetic flux barrier section and a second magnetic flux barrier section arranged side by side in the axial direction, and the mover has the first magnetic flux barrier section in the axial direction. an intermediate portion disposed between the magnetic flux barrier portion and the second magnetic flux barrier portion and having a higher magnetic permeability than the first magnetic flux barrier portion and the second magnetic flux barrier portion; , the first magnetic flux barrier portion is disposed between at least one of the first winding body and the second winding body in the radial direction, and has a higher magnetic permeability than the first magnetic flux barrier portion; The second magnetic flux barrier portion is connected to the first magnetic flux coupling portion and the second magnet holding portion and the intermediate portion, and is located between at least one of the first winding body and the second winding body in the radial direction. and a second magnetic flux coupling portion having a magnetic permeability higher than that of the second magnetic flux barrier portion.

In the interior magnet type motor, it is preferable that the intermediate portion is formed in a cylindrical shape. This facilitates processing of the intermediate portion.

In the embedded magnet type motor, at least one of the first magnetic flux coupling portion and the second magnetic flux coupling portion is preferably formed in a cylindrical shape. This makes these configurations easier to process.

In the embedded magnet type motor, the intermediate portion and at least one of the first magnetic flux coupling portion and the second magnetic flux coupling portion may be integrally formed.

In the interior magnet type motor, the mover is disposed upstream of the first magnet group in the axial direction, and has a third magnetic flux barrier portion having a lower magnetic permeability than the first magnet holding portion; a third magnetic flux guide portion disposed upstream of the third magnetic flux barrier portion in the direction and having a magnetic permeability higher than that of the third magnetic flux barrier portion; A third magnetic flux having a magnetic permeability higher than that of the third magnetic flux barrier portion and disposed so as to sandwich the third magnetic flux barrier portion between at least one of the first winding body and the second winding body in the radial direction. A connecting part may be provided. This improves the efficiency of the embedded magnet motor.

In the embedded magnet type motor, at least one of the third magnetic flux barrier portion, the third magnetic flux guide portion, and the third magnetic flux coupling portion may be formed in a cylindrical shape.

In the interior magnet type motor, the mover is disposed downstream of the second magnet group in the axial direction, and has a fourth magnetic flux barrier portion having a lower magnetic permeability than the second magnet holding portion; a fourth magnetic flux guide portion disposed downstream of the fourth magnetic flux barrier portion in the direction and having a higher magnetic permeability than the fourth magnetic flux barrier portion; A fourth magnetic flux that is disposed so as to sandwich the fourth magnetic flux barrier portion between at least one of the first winding body and the second winding body in the radial direction and has a magnetic permeability higher than that of the fourth magnetic flux barrier portion A connecting part may be provided. This improves the efficiency of the embedded magnet motor.

In the embedded magnet type motor, at least one of the fourth magnetic flux barrier portion, the fourth magnetic flux guide portion, and the fourth magnetic flux coupling portion is preferably formed in a cylindrical shape. This makes these configurations easier to process.

In the embedded magnet type motor, the stator is wound with a conductor wire that constitutes the first winding body or the second winding body, and the conductor wire that constitutes the first winding body is wound in the axial direction. The yoke unit may have a plurality of yoke units that are connected to each other and that the conductor wires that constitute the second winding body are connected to each other. As a result, the stator has a structure that is easy to assemble.

In the interior magnet type motor, the plurality of yoke units preferably have the same shape when projected in the axial direction. This facilitates processing of the yoke unit.

In the above-described embedded magnet type motor, the first winding body has a plurality of first conductor members extending in parallel in an insulated state along the first spiral direction, and the second conductor extends along the second spiral direction. It may have a plurality of second conductor members extending in parallel in an insulated state along the spiral direction. Thereby, the embedded magnet type motor can realize, for example, a two-degree-of-freedom three-phase AC motor.

In the interior magnet type motor, the mover may be arranged radially inwardly of the stator. This makes it possible to realize a two-degree-of-freedom motor with the mover as an axis.

In the interior magnet type motor, the first winding body may be arranged between the second winding body and the mover in the radial direction. Thereby, the stator having the first winding bodies and the second winding bodies in the radial direction can be constructed.

In the interior magnet type motor, the second winding body may be arranged downstream of the first winding body in the axial direction. Thereby, a stator having the first winding body and the second winding body in the axial direction can be constructed.

The embedded magnet type motor includes a driver circuit for applying a position estimation signal having a position estimation frequency higher than a drive AC voltage to the first winding body and the second winding body; a filter circuit for detecting the position estimation signal from currents flowing through the first winding body and the second winding body; an ammeter for measuring a current value of the detected position estimation signal; and an arithmetic circuit for estimating a relative positional relationship between the first winding body or the second winding body and the mover. As a result, the embedded magnet motor can perform position estimation with a simple configuration.

A position estimating device according to the present invention includes: a first winding body including a first conductor extending in a first spiral direction centered on a reference axis; a second winding body including second conductors extending in two helical directions; and a stator relatively movable in a linear direction along the reference axis and centered on the reference axis with respect to the stator. A position estimating device for estimating the relative positional relationship between the stator and the mover of an embedded magnet type motor comprising a mover relatively rotatable in the circumferential direction as a driver circuit for applying a position estimation signal having a frequency for position estimation higher than a driving alternating current to the first winding body and the second winding body; and the first winding body and the second winding body. a filter circuit for detecting the position estimation signal from the current flowing through the wire; an ammeter for measuring the current value of the detected position estimation signal; and based on the current value, the first winding body or and an arithmetic circuit for estimating a relative positional relationship between the second winding body and the mover.

With such a configuration, the position estimation device achieves position estimation of a two-degree-of-freedom embedded magnet motor that can be easily assembled and rotated at high speed with a simple configuration.

A position estimation method according to the present invention includes: a first winding body including a first conductor extending in a first spiral direction centered on a reference axis; a second winding body including second conductors extending in two helical directions; and a stator relatively movable in a linear direction along the reference axis and centered on the reference axis with respect to the stator. A position estimating method for estimating the relative positional relationship between the stator and the mover of an embedded magnet type motor comprising a mover relatively rotatable in the circumferential direction as an applying step of applying a position estimation voltage having a position estimation frequency higher than a driving alternating current to the first winding body and the second winding body; a filtering step for detecting the position estimation current of the position estimation frequency from the current flowing through the winding body; a current measurement step for measuring a current value of the detected position estimation current; and an estimation step of estimating a relative positional relationship between the first winding body or the second winding body and the mover.

With such a configuration, the position estimating method and the position estimating device achieve position estimation of a two-degree-of-freedom embedded magnet motor that can be easily assembled and rotated at high speed with a simple configuration.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a two-degree-of-freedom embedded magnet motor or the like that can be easily assembled and rotated at high speed.

1 is a schematic perspective view showing a basic configuration of an electromagnetic actuator according to Embodiment 1; FIG. 2 is a plan view of a plane perpendicular to the reference axis of the electromagnetic actuator according to the first embodiment; FIG. 2 is a cross-sectional view of a plane parallel to a reference axis of the electromagnetic actuator according to the first embodiment; FIG. 3 is a perspective view of a core portion according to Embodiment 1; FIG. 4 is an exploded perspective view of a magnetic pole unit according to the first embodiment; FIG. FIG. 4 is a perspective view showing the arrangement of magnets in the magnetic pole portion; FIG. 4 is a cross-sectional view showing q-axis magnetic flux in a plane perpendicular to the reference axis in the magnetic pole portion; FIG. 4 is a cross-sectional view showing d-axis magnetic flux in a plane perpendicular to the reference axis in the magnetic pole portion; FIG. 4 is a cross-sectional view showing q-axis magnetic flux in a plane parallel to the reference axis in the magnetic pole portion; FIG. 4 is a cross-sectional view showing d-axis magnetic flux in a plane parallel to the reference axis in the magnetic pole portion; 4 is a diagram showing the relationship between the electrical angle in the rotational direction of the electromagnetic actuator and the torque according to the first embodiment; FIG. 4 is a diagram showing the relationship between the electrical angle in the linear motion direction and the thrust of the electromagnetic actuator according to the first embodiment; FIG. 3 is an exploded perspective view of the stator portion according to the first embodiment; FIG. 4 is a first plan view of a yoke unit according to the first embodiment; FIG. FIG. 4 is a second plan view of the yoke unit according to the first embodiment; 1 is a perspective view of a first winding body according to Embodiment 1; FIG. FIG. 4 is a perspective view of a second winding body according to the first embodiment; 3 is a block diagram of a control circuit; FIG. 1 is a basic circuit diagram of an electromagnetic actuator according to a first embodiment; FIG. FIG. 8 is an exploded perspective view of a first winding body, a second winding body, and a core portion according to a second embodiment; FIG. 11 is an exploded perspective view of a core portion and a stator portion according to a third embodiment; FIG. 11 is a perspective view of a first winding body according to a third embodiment; FIG. 11 is a perspective view of a second winding body according to a third embodiment; FIG. 11 is a perspective view of a first winding body and a second winding body according to a third embodiment;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described through embodiments of the invention, but the invention according to the scope of claims is not limited to the following embodiments. Moreover, not all the configurations described in the embodiments are essential as means for solving the problems. For clarity of explanation, the following descriptions and drawings are omitted and simplified as appropriate. In each drawing, the same elements are denoted by the same reference numerals, and redundant description is omitted as necessary.

<Embodiment 1>
Embodiment 1 will be described below with reference to the drawings. FIG. 1 is a schematic perspective view showing a basic configuration of an electromagnetic actuator according to Embodiment 1. FIG. The electromagnetic actuator 10 according to the first embodiment is an embodiment of an embedded magnet motor. An electromagnetic actuator 10 according to the first embodiment has a core portion 11 and a stator portion 12 . The core portion 11 is a mover of an electromagnetic actuator configured by a member rotationally symmetrical with respect to the reference axis A. As shown in FIG. The stator portion 12 is a stator of an electromagnetic actuator configured to surround a core portion along a predetermined cylindrical surface. The stator portion 12 is also called a yoke portion.

The core portion 11 and the stator portion 12 are installed relative to the reference axis A so as to be linearly movable and rotatable. Therefore, for example, the stator portion 12 is held by an arbitrary case to maintain its posture, and the core portion 11 does not come into contact with the stator portion 12, and is linearly moved and rotated while maintaining a preset distance. supported by et al. With such a configuration, the electromagnetic actuator has two degrees of freedom in the linear motion direction and in the rotational direction.

Electromagnetic actuator 10 is connected to a control circuit for driving core portion 11 . The control circuit is connected to the stator section 12 on the upstream side (lower left side in the figure) and applies a predetermined voltage. In the stator portion 12, a conducting wire is wired from the upstream side to the downstream side (upper right side in the drawing) in a predetermined spiral shape, and the conducting wire is further wired from the downstream side to the upstream side. The conductors are arranged so that a current flowing from the upstream side to the downstream side and a current flowing from the downstream side to the upstream side alternately flow in parallel to generate a Lorentz force. The technology of the two-degree-of-freedom motor in which the conductive wires are wired in a spiral shape is already known to those skilled in the art, and a detailed description thereof will be omitted here. When a voltage is applied to the stator portion 12 from the control circuit, a driving force is generated in the core portion 11 . The control circuit will be described later.

For convenience in explaining the positional relationship of the components, FIG. 1 is attached with a right-handed orthogonal coordinate system and a cylindrical coordinate system superimposed. In FIG. 2 and subsequent figures, when an orthogonal coordinate system or a cylindrical coordinate system is attached, the X-axis, Y-axis, and Z-axis directions of FIG. 1 and the X-axis, Y-axis, and Z-axis directions of these orthogonal coordinate systems are consistent with each other. The axial direction of the rotation axis, which is the reference axis of the electromagnetic actuator, coincides with the Z-axis direction, the radial direction of the electromagnetic actuator is indicated by arrow R, and the circumferential direction of the electromagnetic actuator is indicated by arrow θ. . In the following description, the “inner peripheral side” refers to the side closer to the reference axis A along the arrow R than the “outer peripheral side”. The positive direction in the circumferential direction is the direction from the positive side of the Y-axis to the positive side of the X-axis, as indicated by the arrow in the drawing. In the following description, "upstream side" means the Z-axis minus side, and "downstream side" means the Z-axis plus side.

The configuration of the electromagnetic actuator will be further described with reference to FIGS. 2 and 3. FIG. 2 is a plan view of a plane perpendicular to the reference axis A. FIG. 3 is a cross-sectional view of a plane parallel to the reference axis A. FIG. FIG. 3 shows section III shown in the figure.

The stator portion 12 has a plurality of yoke units 121 and a plurality of yoke connecting portions 125 as main components. The yoke units 121 and the yoke connecting portions 125 are alternately connected along the reference axis A. As shown in FIG.

The yoke unit 121 includes a plurality of coils in which a first conductive wire, which is a component of the first winding body 14 , is wound around the inner circumference of a cylindrical magnetic body, and a second coil, which is a component of the second winding body 15 . It has a plurality of coils and teeth 124 around which two conducting wires are wound. The first winding body 14 is composed of a plurality of coils arranged around the reference axis A. As shown in FIG. The second winding body 15 is composed of a plurality of coils arranged around the reference axis A and on the outer peripheral side of the first winding body 14 . A plurality of teeth 124 are arranged on the inner peripheral side of the first winding body 14, and the inner peripheral surface of the teeth 124 forms a first cylindrical surface with a diameter D1. A detailed configuration of the yoke unit 121 will be described later.

The yoke connecting portion 125 is formed of a cylindrical magnetic material, and is connected to the adjacent yoke units 121 at the two planar portions.

The core portion 11 has, as main components, an axis 111 extending along the reference axis A and a magnetic pole portion 13 fixed around the axis 111 . The magnetic pole portion 13 is cylindrical and has an outer diameter of D2. Diameter D2 is smaller than diameter D1 of the first cylindrical surface formed by teeth 124 . That is, the magnetic pole portion 13 has a second cylindrical surface with a diameter D2 smaller than the diameter D1, and the second cylindrical surface faces the first cylindrical surface with a space therebetween.

Further details of the core portion will now be described. 4 is a perspective view of a core portion according to the first embodiment; FIG. The magnetic pole portion 13 is fixed to the center portion of the shaft 111 of the core portion 11 . The magnetic pole portion 13 is engaged with engaging members 112 at both ends in the axial direction. Thereby, the magnetic pole portion 13 and the shaft 111 are fixed to each other. The magnetic pole portion 13 has a first magnetic pole unit 130A and a second magnetic pole unit 130B axially connected downstream of the first magnetic pole unit 130A. The first magnetic pole unit 130A and the second magnetic pole unit 130B are collectively referred to as the magnetic pole unit 130. As shown in FIG. Similarly, in the following description, when the numerals of the reference numerals of the constituent elements are the same but the alphabetic characters at the end are different, the constituent elements may be collectively referred to only by the numerals of the numerals, omitting the alphabetical characters.

Next, the configuration of each magnetic pole unit will be described with reference to FIG. FIG. 5 is an exploded perspective view of the magnetic pole unit 130. FIG. The first magnetic pole unit 130A mainly includes a first magnet holding portion 131A, a magnet 133, a first magnetic flux barrier portion 135A, a third magnetic flux barrier portion 135C, a first magnetic flux guide portion 136A and a third magnetic flux guide portion 136C. ing. The second magnetic pole unit 130B mainly includes a second magnet holding portion 131B, a magnet 133, a second magnetic flux barrier portion 135B, a fourth magnetic flux barrier portion 135D, a second magnetic flux guide portion 136B and a fourth magnetic flux guide portion 136D. ing. Each of these configurations of the magnetic pole unit 130 has a positioning portion 134, and is fixed by each adjacent configuration and the positioning portion 134 without positional deviation.

The first magnet holding portion 131A and the second magnet holding portion 131B are made of a magnetic material having a second cylindrical surface 131S with a diameter D2, and hold a magnet group made up of a plurality of magnets 133 inside. . The magnetic material that forms the magnet holding portion 131 is, for example, a ferromagnetic material such as iron, stainless steel, or silicon steel plate. In this embodiment, the magnet holder 131 has a magnet group composed of four rectangular plate-shaped magnets 133 . The four magnets 133 constituting the magnet group are embedded at positions rotated by 90 degrees around the reference axis A and at equal distances from the reference axis A. As shown in FIG. At this time, the four magnets 133 are arranged along each surface of the quadrangular prism formed with the reference axis A as the central axis. The magnet holder 131 shown in the figure holds the magnets 133 so that the main surfaces of the magnets 133 are parallel to the XZ plane or the YZ plane. Also, the shortest distance from the reference axis A to the magnet 133 is configured to be the same. The axial length of the magnet 133 is the same as the axial length of the magnet holding portion 131, and is configured to form the same end face. Here, the magnet is “embedded” means that at least a portion of the magnet is embedded in the magnet holding portion 131, and a portion of the magnet is exposed on the surface of the magnet holding portion 131. good too. Moreover, the axial length of the magnet 133 may be shorter than that of the magnet holder 131 as long as it is fixed at a predetermined position inside the magnet holder 131 .

The magnet holder 131 has air gaps 132 at both ends of the magnet 133 in the circumferential direction. The air gap 132 is formed in contact with the end face of the magnet 133 in the circumferential direction. By configuring the air gap 132 in this way, the air gap 132 prevents short-circuiting of the magnetic flux at the end face of the magnet 133 . The polarity of magnet 133 will be described later.

The magnetic flux barrier portion 135 is a plate-like member made of a material having a lower magnetic permeability than the magnet holding portion 131 . The outer diameter of the magnetic flux barrier portion 135 is the same diameter D2 as that of the magnet holding portion 131 . A material having a magnetic permeability lower than that of the magnet holding portion is typically a non-magnetic material such as aluminum, copper, paper, etc., when iron or the like having a relatively high magnetic permeability is used for the magnet holding portion. It should be noted that the magnetic flux barrier section 135 may be configured by providing a space in place of such a material or in addition to such a material.

The magnetic flux barrier portion 135 is arranged in contact with the axial end surface of the magnet holding portion 131 . As a result, the magnetic flux barrier portion 135 comes into contact with the axial end surface of the magnet 133 . Therefore, the magnetic flux barrier portion 135 holds the magnet 133 in the axial direction. Magnetic flux barrier portion 135 suppresses magnetic flux flowing between magnet holding portion 131 and magnetic flux guide portion 136 by being interposed between magnet holding portion 131 and magnetic flux guide portion 136 . If the axial length of the magnet 133 is shorter than that of the magnet holding portion 131 , an air gap exists between the magnet 133 and the contact surface between the magnet holding portion 131 and the magnetic flux barrier portion 135 .

The magnetic flux guide portion 136 is a cylindrical member made of the same material as the magnet holding portion 131 . The material equivalent to that of the magnet holding portion 131 does not have to be the same material as that of the magnet holding portion 131, and may be a member having a magnetic permeability higher than that of the magnet 133, the magnetic flux barrier portion 135, and the like. The outer diameter of the magnetic flux guide portion 136 is the same diameter D2 as that of the magnet holding portion 131 . The magnetic flux guide portion 136 is adjacent to the magnetic flux barrier portion 135 on the side opposite to the side in contact with the magnet 133 . A magnetic flux coupling portion 137 that protrudes toward the magnet holding portion 131 is provided on the inner peripheral side of the magnetic flux guide portion 136 . The magnetic flux coupling portion 137 is formed so as to extend along the inner peripheral side of the magnetic flux barrier portion 135 and is configured to come into contact with the magnet holding portion 131 . In other words, the magnetic flux coupling portion 137 is arranged so as to sandwich the magnetic flux barrier portion 135 with at least one of the first winding body 14 and the second winding body 15 in the radial direction.

As shown in FIG. 5, in this embodiment, the first magnetic pole unit 130A and the second magnetic pole unit 130B have the same configuration. In the first magnetic pole unit 130A, the third magnetic flux guide portion 136C, the third magnetic flux barrier portion 135C, the first magnet holding portion 131A, the first magnetic flux barrier portion 135A, and the first magnetic flux guide portion 136A are connected in this order from the upstream side. ing. In the second magnetic pole unit 13B, the second magnetic flux guide portion 136B, the second magnetic flux barrier portion 135B, the second magnet holding portion 131B, the fourth magnetic flux barrier portion 135D, and the fourth magnetic flux guide portion 136D are connected in this order from the upstream side. ing. The first magnetic flux guide portion 136A and the second magnetic flux guide portion 136B are connected to each other. In other words, the magnetic pole unit 130 is configured by axially connecting elements each having a diameter D2. Since each component is formed in a cylindrical shape in this way, each component of the magnetic pole unit 130 can be easily lathe-processed. The magnetic flux coupling portion 137 may be included in the magnet holding portion 131 instead of the magnetic flux guide portion 136, or may be configured as a separate component. Further, although the first magnetic flux guide portion 136A and the second magnetic flux guide portion 136B in the present embodiment are intermediate portions formed separately, they may be integrally formed intermediate portions.

Next, the polarity of magnet 133 will be described with reference to FIG. FIG. 6 is a perspective view showing the arrangement of magnets in the magnetic pole portion. In the drawing, the outer diameter of the magnetic pole portion 13 is indicated by a dotted line, and the magnet 133 of the magnet holding portion 131 is shown transparently. In the following description, the four magnet group of the first magnetic pole unit 130A may be referred to as the first magnet group, and the four magnet group of the second magnetic pole unit 130B may be referred to as the second magnet group.

The magnets 133 shown in the figure are divided into magnets 133N and magnets 133S according to the polarities on the outer peripheral side. The magnet 133N has the letter "N" indicating polarity on the main surface on the outer peripheral side. Alternatively, when the outer main surface of the magnet 133N is not shown, the character indicating the polarity is shown in brackets "(S)" on the inner main surface, and the outer main surface is An "N" is indicated by an arrow pointing toward it. The magnets 133S are similarly labeled with letters indicating the opposite polarity to the magnets 133N described above.

As shown in the figure, in the magnetic pole portion 13, the magnets 133N and the magnets 133S contained inside are arranged so that the polarities of the magnets 133N and 133S adjacent to each other in the axial direction or the circumferential direction are different from each other. That is, for example, in the present embodiment, different magnetic poles are alternately arranged in the circumferential direction of the first magnet group and the second magnet group, and the two magnetic pole units 130 are connected to each other in the axial direction. By rotating 90 degrees in the rotational direction, different magnetic poles are arranged adjacent to each other even in the axial direction.

The magnetic pole unit 130 is thus constructed by connecting a plurality of elements in the axial direction. The magnetic pole portion 13 shown in FIG. 4 is configured by connecting a plurality of magnetic pole units 130 in the axial direction. Furthermore, as shown in FIG. 6, when the magnetic pole portion 13 is configured by connecting a plurality of magnetic pole units 130, adjacent magnets 133 are arranged so that the polarities thereof are different. That is, according to the present embodiment, a magnetic pole portion can be configured in which different magnetic poles are alternately arranged. With such a configuration, in this embodiment, the IPM type magnetic pole portion having the magnet 133 inside can be easily assembled.

Next, the states of the q-axis magnetic flux and the d-axis magnetic flux acting on the magnetic pole portion 13 will be described with reference to FIGS. 7 to 10. FIG. There is a technique called dq conversion for controlling the current of a general three-phase motor. By using this dq transformation, the U-phase, V-phase and W-phase coils can be virtually transformed into d-axis and q-axis coils. The d-axis magnetic flux and the q-axis magnetic flux indicate the magnetic flux generated by this virtual coil, and the d-axis current and q-axis current indicate the current flowing through these virtual coils. Note that the dq transform is a known technique, and detailed description thereof will be omitted in the present embodiment.

The q-axis magnetic flux in the plane perpendicular to the reference axis (the plane parallel to the XY plane) will be described with reference to FIG. FIG. 7 is a cross-sectional view showing q-axis magnetic flux in a plane perpendicular to the reference axis in the magnetic pole portion. In the figure, the q-axis magnetic flux Φq is indicated by a dotted arrow. The magnetic flux Φq flows through the magnets 133 (magnets 133N and 133S) and the cross-sectional shape of the air gap 132 adjacent to the magnets 133, respectively, on the outer circumference side and the inner circumference side of the magnets. That is, on the plane perpendicular to the reference axis A, the magnet 133 held inside the magnetic body and the air gap 132 adjacent to the end of the magnet 133 form a magnetic path of the magnetic flux Φq. Further, the magnet holding portion 131 has a magnetic body with a suitable thickness for allowing the magnetic flux Φq to flow in the formed magnetic path, and does not have an element that hinders the magnetic flux Φq.

Next, the d-axis magnetic flux in the plane orthogonal to the reference axis will be described with reference to FIG. FIG. 8 is a cross-sectional view showing d-axis magnetic flux in a plane perpendicular to the reference axis in the magnetic pole portion. In the figure, the d-axis magnetic flux Φd is indicated by a dotted arrow. The magnetic flux Φd, for example, passes through the magnet 133N, flows toward the magnet 133S, and then passes through the magnet 133S. Also, the magnetic flux Φd flows through the air gap 132 at the end of the magnet 133 . As shown in the figure, the magnetic flux Φd passes through the magnet 133 and the air gap 132 , which have relatively lower magnetic permeability than the magnetic material of the magnet holder 131 .

As described above, in the plane orthogonal to the reference axis A, the magnetic flux Φq flows through the magnetic material having higher magnetic permeability than the magnet 133 and the air gap 132 . On the other hand, the magnetic flux Φd passes through the magnet 133 and the air gap 132 which have a lower magnetic permeability than the magnetic material forming the magnet holding portion 131 . Therefore, the magnetic flux Φq becomes larger than the magnetic flux Φd. Therefore, the inductance Lq applied to the magnetic flux Φq is larger than the inductance Ld applied to the magnetic flux Φd. In this manner, by providing a difference in the ease of flow of the magnetic flux Φq and the magnetic flux Φd, the electromagnetic actuator 10 according to the present embodiment generates reluctance torque (rotational force) in the rotational direction at the magnetic pole portion 13 .

Next, the q-axis magnetic flux in a plane parallel to the reference axis A will be described with reference to FIG. FIG. 9 is a sectional view showing q-axis magnetic flux in a plane parallel to the reference axis in the magnetic pole portion 13 . The cross section shown in the figure shows a cross section parallel to the XZ plane as an example of a plane parallel to the reference axis A. FIG. In the figure, the q-axis magnetic flux Φq is indicated by a dotted arrow. The magnetic flux Φq flows through the magnets 133 and the magnetic flux barrier portions 135 adjacent to the magnets 133 at four locations along the cross-sectional shapes of the magnets 133 and the magnets 133 . That is, on the plane perpendicular to the reference axis A, the magnet 133 held inside the magnetic body and the magnetic flux barrier portion 135 adjacent to the end of the magnet 133 form a magnetic path of the magnetic flux Φq. Further, the magnet holding portion 131 has a magnetic body with a suitable thickness for allowing the magnetic flux Φq to flow in the formed magnetic path, and does not have an element that hinders the magnetic flux Φq. To give a more specific example, in the first magnetic pole unit 130A, one magnetic flux Φq flows from the first magnetic flux guide portion 136A to the first magnetic flux coupling portion 137A, the first magnet holding portion 131A, and the third magnetic flux coupling portion 137C. Then, it flows through the third magnetic flux guide portion 136C. As another specific example, in the second magnetic pole unit 130B, one magnetic flux Φq flows from the second magnetic flux guide portion 136B to the second magnetic flux coupling portion 137B, the second magnet holding portion 131B, and the fourth magnetic flux coupling portion 137D. Then, it flows through the fourth magnetic flux guide portion 136D.

Next, the d-axis magnetic flux in a plane parallel to the reference axis will be described with reference to FIG. FIG. 10 is a cross-sectional view showing the d-axis magnetic flux in the plane parallel to the reference axis in the magnetic pole portion 13 . FIG. 10 is a cross-sectional view showing d-axis magnetic flux in a cross section parallel to the XZ plane. In the figure, the d-axis magnetic flux Φd is indicated by a dotted arrow. The magnetic flux Φd flows from the magnetic pole unit 130 on the right side to the magnetic pole unit 130 on the left side through the magnet 133 or the magnetic flux barrier section 135 . That is, the magnetic flux Φd passes through the magnet 133 and the magnetic flux barrier portion 135, which have relatively lower magnetic permeability than the magnetic material of the magnet holding portion 131. FIG.

As described above, in the plane parallel to the reference axis A, the magnetic flux Φq flows through the magnetic material having higher magnetic permeability than the magnet 133 and the air gap 132 . On the other hand, the magnetic flux Φd passes through the magnet 133 and the magnetic flux barrier portion 135 which have a lower magnetic permeability than the magnetic material forming the magnet holding portion 131 . Therefore, the magnetic flux Φq becomes larger than the magnetic flux Φd. Therefore, the inductance Lq applied to the magnetic flux Φq is larger than the inductance Ld applied to the magnetic flux Φd. In other words, the magnetic pole portion 13 is set so that the ease of flow of the magnetic flux Φq is different from the ease of flow of the magnetic flux Φd. In this manner, by providing a difference in the ease of flow of the magnetic flux Φq and the magnetic flux Φd, the electromagnetic actuator 10 according to the present embodiment generates reluctance force (thrust force) in the linear motion direction in the magnetic pole portion 13 .

電磁アクチュエータ１０は、第１巻線体と第２巻線体の２種類の三相コイルを有し、第１巻線体のｄ軸電流及びｑ軸電流と、第２巻線体のｄ軸電流及びｑ軸電流が設けられている。従って、電磁アクチュエータ１０には、第１巻線体の電気角β１と第２巻線体の電気角β２とが設けられている。次に、電磁アクチュエータ１０が発生する力について説明する。発明者らは、本実施の形態にかかる電磁アクチュエータ１０の構造をコンピュータ上でシミュレーションし、コア部１１とステータ部１２との間に発生する回転方向の力（回転力）と直動方向の力（推力）を算出した。 In general IPM motors, not only magnet torque (magnetic force) but also reluctance torque (reluctance force) can be used by appropriately determining the electrical angle related to the ratio of d-axis current and q-axis current. The electrical angle β is defined by the following formula.

The electromagnetic actuator 10 has two types of three-phase coils, a first winding body and a second winding body. Current and q-axis current are provided. Therefore, the electromagnetic actuator 10 is provided with an electrical angle β1 of the first winding body and an electrical angle β2 of the second winding body. Next, the force generated by the electromagnetic actuator 10 will be described. The inventors simulated the structure of the electromagnetic actuator 10 according to the present embodiment on a computer, and found that the force in the rotational direction (rotational force) and the force in the linear motion direction generated between the core portion 11 and the stator portion 12 (thrust) was calculated.

Next, the relationship between the rotational force generated by the electromagnetic actuator 10 and the electrical angle β will be described with reference to FIG. 11 . FIG. 11 shows the results of a computer simulation of the structure of the electromagnetic actuator 10 according to the present embodiment by the inventors, and the calculation of the force in the rotational direction (rotational force) generated between the core portion 11 and the stator portion 12. This is the result. In the graph shown in the drawing, the horizontal axis indicates the electrical angle β, and the vertical axis indicates the torque. In the following description, the electrical angle β indicates the electrical angle β1 of the first winding body and the electrical angle β2 of the second winding body. For example, the electrical angle β=40 degrees indicates that the electrical angle β of the first winding body is 40 degrees and the electrical angle β2 of the second winding body is 40 degrees.

The three curves plotted on the graph are, from the bottom, the rotational reluctance torque, the magnet torque and the sum of these. That is, the reluctance torque is approximately 0.15 Nm at an electrical angle of 0 degrees, gradually increases as the electrical angle increases, and reaches 0.5 Nm near an electrical angle of 45 degrees. From there, it gradually decreases as the electrical angle increases, reaching 0 Nm at an electrical angle of 90 degrees. On the other hand, the magnet torque is 1 Nm from 0 to 30 electrical degrees, and then gradually decreases to 0 Nm at 90 electrical degrees. Summing up the reluctance torque and the magnet torque, the rotational force of the electromagnetic actuator 10 draws a curve with a maximum torque of about 1.43 Nm near an electrical angle of 40 degrees.

Next, the relationship between the thrust generated by the electromagnetic actuator 10 and the electrical angle β will be described with reference to FIG. 12 . FIG. 12 shows the results of a computer simulation of the structure of the electromagnetic actuator 10 according to the present embodiment by the inventors, and the calculation of the force (thrust force) in the linear motion direction generated between the core portion 11 and the stator portion 12. This is the result. In the graph shown in the figure, the horizontal axis indicates the electrical angle β, and the vertical axis indicates the thrust force. The three curves plotted on the graph are the reluctance force in the linear direction, the magnet force and the sum of these from the bottom. That is, the reluctance force is approximately 5 N at an electrical angle of 0 degrees, gradually increases as the electrical angle increases, and reaches approximately 28 N near an electrical angle of 50 degrees. From there, it gradually decreases as the electrical angle increases, reaching 0 Nm at an electrical angle of 90 degrees. On the other hand, the magnet force is approximately 59 N from 0 to 20 electrical degrees, and then gradually decreases to 0 Nm at 90 electrical degrees. Summing up the reluctance force and the magnet force, the thrust force of the electromagnetic actuator 10 draws a curve with a maximum thrust force of approximately 80 N near an electrical angle of 40 degrees.

Thus, the simulation showed that the electromagnetic actuator 10 not only generated reluctance torque in the rotational direction, but also generated reluctance force in the linear direction. That is, this simulation showed that the electromagnetic actuator 10 generates a reluctance force in the linear motion direction by providing the magnetic flux barrier portion 135 in the magnetic pole portion 13 .

Next, the configuration of the stator section 12 will be described in detail. 13 is an exploded perspective view of a stator portion according to the first embodiment; FIG. In the stator portion 12, along the reference axis A, yoke units 121 and yoke connecting portions 125 are alternately connected. In the drawing, the yoke unit 121 arranged at the end on the Z-axis minus side (upstream side) is indicated as a yoke unit 121a. In addition, the stator portion 12 includes a yoke unit 121a, a yoke connecting portion 125, a yoke unit 121b, a yoke connecting portion 125, a yoke unit 121c, .・ is connected with

The yoke unit 121a is shown by omitting part of the coil. As shown in the figure, the yoke unit 121 has a cylindrical back yoke 122 and a coil yoke 123 extending from the inner peripheral surface of the back yoke 122 toward the inner peripheral side. The back yoke 122 and the coil yoke 123 can be integrally molded, for example, by pressing a plate made of a magnetic material. In this embodiment, six coil yokes 123 are provided. A plurality of connected yoke units 121 have the same shape when projected in the axial direction. Therefore, for example, the plurality of yoke units 121 can be formed by pressing a plate material containing a magnetic material as a main component.

The yoke connecting portion 125 is made of a cylindrical magnetic body. Like the back yoke 122 and the coil yoke 123, the yoke connecting portion 125 can be formed by pressing a plate made of a magnetic material. By providing the yoke connecting portion 125 between the yoke units 121 in this manner, the stator portion 12 can be easily processed.

Next, the configuration of adjacent yoke units 121 will be described with reference to FIGS. 14 and 15. FIG. 14 is a first plan view of a yoke unit according to the first embodiment; FIG. FIG. 14 is a plan view of the yoke unit 121a, viewed along the Z-axis. Also, FIG. 14 is partially shown as a cross section.

The yoke unit 121a has six coil yokes 123 provided every 60 degrees in the rotational direction. Of the six coil yokes 123, two opposing coil yokes 123 are provided parallel to the X-axis. Teeth 124 are provided on the inner peripheral side of the coil yoke 123 . The coil yoke 123 has a coil, which is a constituent element of the first winding body 14, wound on the inner peripheral side thereof, and does not conduct electricity with the first winding body 14 on the outer peripheral side of the first winding body 14. , the coil, which is a component of the second winding body 15, is wound. An insulating member may be provided between the conductor wire that forms the first winding body 14 and the conductor wire that forms the second winding body 15 so as not to conduct electricity.

By the way, the electromagnetic actuator 10 according to this embodiment is a three-phase AC motor. Therefore, the first winding body 14 has coils corresponding to each of the U-phase, V-phase and W-phase. In the figure, coil 14U corresponds to the U phase, coil 14V corresponds to the V phase, and coil 14W corresponds to the W phase. In other words, AC currents with different phases are applied to the coil 14U of the first winding body 14 and to the coils 14V and 14W. In the figure, coils 14U are wound around coil yokes 123 parallel to the X-axis. A coil 14V corresponding to the V phase is wound around the adjacent coil yoke 123 rotated 60 degrees in the negative θ direction in the circumferential direction. A coil 14W corresponding to the phase is wound.

Like the first winding body 14, the second winding body 15 also has coils 15U, 15V, and 15W corresponding to the U-phase, V-phase, and W-phase, respectively. In the figure, a yoke unit 121a has two coil yokes 123 parallel to the X-axis, each of which has a coil 15W wound thereon. The coil 15U corresponding to the U phase is wound around the adjacent coil yoke 123 rotated 60 degrees in the negative θ direction in the circumferential direction, and the V coil 15U is wound around the adjacent coil yoke 123 rotated 60 degrees in the negative θ direction. A coil 15V corresponding to the phase is wound.

Next, the yoke unit 121b will be explained. 15 is a second plan view of the yoke unit according to the first embodiment; FIG. FIG. 15 is a plan view of the yoke unit 121b, viewed along the Z-axis. The coil yoke 123 of the yoke unit 121b shown in FIG. 15 is rotated 30 degrees in the circumferential direction as compared with the yoke unit 121a shown in FIG. In this manner, the stator portion 12 of the electromagnetic actuator 10 is connected with the coil yoke 123 of the adjacent yoke unit rotated by 30 degrees. As a result, the stator portion 12 suitably generates q-axis magnetic flux in the magnetic pole portion 13 .

In the figure, coils 14U are wound on the inner circumference sides of two coil yokes 123 that are inclined 30 degrees in the negative θ direction with respect to the X-axis. A coil 14V corresponding to the V phase is wound around the adjacent coil yoke 123 rotated 60 degrees in the negative θ direction in the circumferential direction. A coil 14W corresponding to the phase is wound. That is, the first winding body 14 of the yoke unit 121b adjacent to the yoke unit 121a is arranged at a position relatively rotated in the minus θ direction by 30 degrees.

In the drawing, coils 15W are wound around the outer circumferences of two coil yokes 123 that are inclined 30 degrees in the plus θ direction with respect to the X-axis. The coil 15U corresponding to the U phase is wound around the adjacent coil yoke 123 rotated 60 degrees in the negative θ direction in the circumferential direction, and the V coil 15U is wound around the adjacent coil yoke 123 rotated 60 degrees in the negative θ direction. A coil 15V corresponding to the phase is wound. That is, the second winding body 15 of the yoke unit 121b adjacent to the yoke unit 121a is arranged at a position rotated by 30 degrees in the positive θ direction.

Next, the configuration of the coils of the first winding body 14 will be described with reference to FIG. 16 . 16 is a perspective view of a first winding body according to Embodiment 1. FIG. FIG. 16 shows the extracted coils of the first winding body 14 of the stator section 12 . The darkly shaded coil shown in the figure is the coil 14U. The coil 14V is the coil 14V that is shown at a position adjacent to the coil 14U by rotating it by 60 degrees in the minus .theta. A coil 14W that is not hatched (white) is shown at a position adjacent to the coil 14V by rotating it in the minus θ direction by 60 degrees. As shown in the figure, the coil 14U, the coil 14V, and the coil 14W are arranged such that they are sequentially rotated 30 degrees in the negative θ direction as they move in the positive direction of the Z axis. Therefore, as indicated by an arrow 14R shown around the first winding body 14, each coil of the first winding body 14 extends around the reference axis A in the same direction as the right-handed screw (right-hand spiral direction). spirally connected. That is, the first winding body 14 is composed of a plurality of first conductor members extending in parallel along the right spiral direction. The first winding body 14 has first conductor members of at least three phases, U phase, V phase and W phase, which are insulated from each other.

Next, the configuration of the coils included in the second winding body 15 will be described with reference to FIG. 17 . 17 is a perspective view of a second winding body according to Embodiment 1. FIG. FIG. 17 shows the extracted coils of the second winding body 15 of the stator section 12 . The darkly shaded coil shown in the drawing is the coil 15U. A coil 15V is shown at a position adjacent to the coil 15U by rotating it by 60 degrees in the minus .theta. direction and shaded lighter than the coil 15U. A coil 15W that is not hatched (white) is shown at a position adjacent to the coil 15V by rotating it by 60 degrees in the minus .theta. direction. As shown in the figure, the coil 15U, the coil 15V, and the coil 15W are arranged so as to rotate 30 degrees in the positive θ direction in order as they move in the positive direction of the Z axis. Therefore, as indicated by an arrow 15L shown around the second winding body 15, each coil of the second winding body 15 is spirally wound around the reference axis A in the same direction as the left-handed screw (left-handed spiral direction). It is connected to the. That is, the second winding body 15 is composed of a plurality of second conductor members extending in parallel along the left spiral direction. The second winding body 15 has second conductive wire members of at least three phases, U phase, V phase and W phase, which are insulated from each other.

The coils of the first winding body 14 are spirally connected in the right spiral direction. That is, the first winding body 14 is set so that an in-phase current flows in the right spiral direction. Therefore, the coil yoke 123 around which the coil 14U is wound generates an in-phase magnetic field in the right spiral direction on the inner peripheral side of the teeth 124 . Therefore, the first winding body 14 can apply to the magnetic pole portion 13 a magnetomotive force in the left-hand spiral direction perpendicular to the right-hand spiral direction. Similarly, the coils of the second winding body 15 are spirally connected in a leftward spiral direction intersecting the spiral direction of the first winding body 14 . Therefore, the first winding body 14 can apply to the magnetic pole portion 13 a magnetomotive force in the right-hand spiral direction perpendicular to the left-hand spiral direction. Therefore, the electromagnetic actuator 10 can constitute an electromagnetic actuator having two degrees of freedom.

As described above, according to the embodiment, it is possible to provide an interior magnet type motor that is easy to assemble. Further, by connecting a plurality of coils in a spiral manner as described above, the electromagnetic actuator can improve the line space factor. In addition, as described above, the two-degree-of-freedom magnetic pole portion having different magnetic poles alternately arranged and two sets of winding bodies formed by intersecting a plurality of conducting wires in a state of being electrically insulated from each other are arranged. Since the technology of electromagnetic actuators is already known, a detailed description of the drive principle is omitted here.

(Position estimation function)
Next, the position estimation function of the electromagnetic actuator 10 will be described. The electromagnetic actuator 10 drives the magnetic pole portion 13 by applying an AC voltage to the stator portion 12 to generate a magnetic field in the coil yoke 123 . At this time, since the magnet 133 built in the magnetic pole portion 13 is displaced, the inductance of the U-phase to W-phase coils varies. It is possible to detect variations in the magnetic field due to the displacement of . The control circuit that drives the electromagnetic actuator 10 according to the present embodiment has a function of estimating the position of the mover by detecting variations in this magnetic field.

A control circuit having a position estimation function will be described with reference to FIG. FIG. 18 is a block diagram of the control circuit. The control circuit 300 is connected to the stator portion 12 of the electromagnetic actuator 10 and drives the core portion 11 . The control circuit 300 has a driver circuit 310 and a position estimation circuit 320 as main components.

The driver circuit 310 is a power supply circuit including a three-phase AC power supply for driving the mover, and includes a drive circuit for applying AC voltages of different phases to each of the U-phase, V-phase and W-phase layers. . In addition to the AC voltage for driving the mover, the driver circuit 310 has a function of generating an AC voltage having a frequency higher than that of the driving AC voltage in order to estimate the position of the mover. . In the following description, the AC voltage for estimating the position of the mover will be referred to as a position estimation signal. The frequency of the position estimation signal (frequency for position estimation) is preferably a frequency that can be clearly distinguished from the driving AC voltage. For example, the position estimation frequency is about several tens of times the frequency of the driving AC voltage. Also, the voltage of the position estimation signal is a small value of about 5% to 20% compared to the AC voltage for driving.

The position estimation circuit 320 has a configuration for estimating the position of the mover. The position estimation circuit 320 has a high-pass filter 321, an ammeter 322 and an arithmetic circuit 323 as main components.

A high-pass filter 321 is a filter circuit for extracting a position estimation signal from the current flowing through the stator section 12 . Note that the high-pass filter 321 may be a band-pass filter instead of the high-pass filter. Ammeter 322 measures the current value of the position estimation signal extracted by high-pass filter 321 . The arithmetic circuit 323 performs arithmetic operations for estimating the position of the mover, that is, the relative positional relationship between the first winding body 14 or the second winding body 15 and the magnetic pole portion 13 from the current value measured by the ammeter 322. I do. Note that the ammeter 322 is used not only for position estimation but also for drive control of the electromagnetic actuator 10 . That is, the ammeter 322 is used for current feedback control when the electromagnetic actuator 10 is driven. Therefore, there is no need to provide a separate ammeter 322 for the position estimation function shown here.

Next, the principle for estimating the position of the mover will be described. 19 is a basic circuit diagram of the electromagnetic actuator according to the first embodiment; FIG. FIG. 19 schematically shows an operation circuit of the electromagnetic actuator 10. As shown in FIG. The electromagnetic actuator 10 has a control circuit 300 . The control circuit 300 has a circuit connected to the first winding body 14 and a circuit connected to the second winding body 15, respectively.

As shown in FIG. 19, the first winding body 14 of the electromagnetic actuator 10 has a U-phase coil 14U, a V-phase coil 14V, and a W-phase coil 14W. The control circuit 300 has an AC power supply for applying an AC voltage to these coils.

For example, a voltage E _{in_U} is applied to the coil 14U. The current flowing through the coil 14U at this time is I _{in_U} . Also, the inductance of the coil 14U is L _{in — U} (α _in ). Here, α _in is the mechanical angle of the left spiral direction of the magnetic pole portion 13 . Similarly, voltage E _{in_V} is applied to coil 14V. The current flowing through the coil 14V at this time is I _{in_V} . Also, the inductance of the coil 14V is L _{in — V} (α _in ). A voltage E _{in_W} is applied to the coil 14W. The current flowing through the coil 14W at this time is I _{in_W} . Also, the inductance of the coil 14W is L _{in — W} (α _in ).

The voltage, current and inductance of the coil 15U, the coil 15V and the coil 15W of the second winding body 15 are shown similarly to the first winding body 14 described above. A voltage E _{out_U} is applied to the coil 15U. The current flowing through the coil 15U at this time is _{Iout_U} . Also, the inductance of the coil 15U is L _{out — U} (α _out ). Here, α _out is the mechanical angle of the right spiral direction of the magnetic pole portion 13 . Similarly, voltage E _{out_V} is applied to coil 15V. The current flowing through the coil 15V at this time is _{Iout_V} . Also, the inductance of the coil 15V is L _{out — V} (α _out ). A voltage E _{out_W} is applied to the coil 15W. The current flowing through the coil 15W at this time is _{Iout_W} . Also, the inductance of the coil 15W is L _{out — W} (α _out ).

ここで、ｆ_ｉｎは第１巻線体１４に印加する位置を推定するための交流電圧の周波数（位置推定用周波数）であり、ｔは時間であり、ｆ_ｏｕｔは第２巻線体１５に印加する位置を推定するための交流電圧の周波数である。また、ｚは直動方向の位置であり、ｌ_ｍはｚ方向における磁石の極性１周期分の長さであり、θは回転方向の角度を示す。 The voltage, current and mechanical angle shown in FIG. 19 have the following relationships.

Here, f _in is the frequency of the AC voltage applied to the first winding body 14 for estimating the position (frequency for position estimation), t is the time, and f _out is the frequency of the second winding body 15. This is the frequency of the AC voltage for estimating the applied position. Also, z is the position in the rectilinear direction, _lm is the length of one cycle of the polarity of the magnet in the z direction, and θ is the angle in the rotational direction.

The first term on the right side of equations (1) to (6) is a voltage for generating rotational force or thrust, and depends on the position of the mover, that is, the mechanical angle α _in or α _out . The second term on the right side of equations (1) to (6) is the voltage for generating the position estimation signal and is time dependent. As a result, a high-frequency current for position estimation flows through each coil together with the current for driving.

By the way, in the IPM type electromagnetic actuator 10, the inductance of each coil varies according to the position of the mover. Therefore, the position estimation circuit 320 extracts the position estimation signal using the high-pass filter 321 and measures the current value (position estimation current) of the extracted position estimation signal. Thereby, the position estimation circuit 320 estimates the position of the mover.

More specifically, the position estimation circuit 320 uses the first winding body 14 to estimate the position of the mover in the left spiral direction, which is the driving direction of the first winding body 14 . Similarly, the position estimation circuit 320 uses the second winding body 15 to estimate the position of the mover in the right spiral direction, which is the driving direction of the second winding body 15 . The position estimation circuit 320 estimates the movement of the mover by combining the positions estimated using the first winding body 14 and the second winding body 15 in this way.

上式において、第３項である近似式は、機械角α_ｉｎおよびα_ｏｕｔの変動に対して位置推定信号の周波数ｆ_ｉｎおよびｆ_ｏｕｔが充分に大きい場合を示している。 The relationship between voltage and current in the electromagnetic actuator 10 is shown below.

In the above equation, the approximation expression, which is the third term, indicates the case where the frequencies f _in and f _out of the position estimation signal are sufficiently large with respect to the fluctuations of the mechanical angles α _in and α _out .

さらに、式（１２）から位置推定信号の成分を抽出すると、抽出された位置推定用電流の値である電流値Ｉ´_ｉｎ＿Ｕは以下となる。

From the above equation, for example, the current value I _{in_U} in the U-phase coil 14U of the first winding body 14 is as follows.

Furthermore, when the component of the position estimation signal is extracted from Equation (12), the current value _{I'in_U} , which is the value of the extracted current for position estimation, is as follows.

Thus, the amplitude of the current value _{I'in_U} of the position estimation signal in the coil 14U depends on the mechanical angle _αin . Similarly, the current values of the position estimation signals in coils 14V and 14W also depend on the mechanical angle _αin . On the other hand, the current values of the position estimation signals in coils 15U, 15V and coil 15W depend on the mechanical angle α _out . Therefore, the position estimation circuit 320 calculates the amplitude of the current value of the position estimation signal for each coil as described above. Thereby, the position estimation circuit 320 estimates the position of the mover.

The position estimation function of the electromagnetic actuator 10 has been described above. According to the present embodiment, the electromagnetic actuator 10 can realize a sensorless electromagnetic actuator by having a position estimation circuit in place of the Hall element and resolver for position estimation.

Although the first embodiment has been described above, the electromagnetic actuator 10 according to the embodiment is not limited to the configuration described above. For example, in the electromagnetic actuator 10, the back yoke 122 and the yoke connecting portion 125 may be one component instead of being separate components. In the above example, the stator portion 12 surrounds the core portion 11, but the yoke unit 121 of the stator portion 12 has a configuration in which the coil yoke 123 protrudes outward from the back yoke 122. The core portion 11 may have a hollow cylindrical shape so as to surround the stator portion with the outer circumference of the stator portion 12 . Further, the stator portion 12, which is the stator in the above description, may be moved, and the core portion 11, which is the mover, may be fixed. In that case, the member having the first winding body and the second winding body (stator portion 12 described above) is referred to as a mover, and has the above-described first magnet holding portion and second magnet holding portion. You may call the member (core part 11) which is in a stator.

As described above, according to the present embodiment, it is possible to provide a two-degree-of-freedom embedded magnet motor that can be easily assembled and rotated at high speed. Further, according to the present embodiment, it is possible to provide a two-degree-of-freedom embedded magnet motor that is easy to assemble and has a position estimation function. Moreover, such a position estimation function can be realized without adding a new ammeter.

<Embodiment 2>
Next, Embodiment 2 will be described with reference to FIG. The electromagnetic actuator according to the second embodiment differs from the first embodiment in that the first winding body and the second winding body are arranged in series with the reference axis A, respectively. Along with this, the electromagnetic actuator according to the second embodiment has a first magnetic pole portion corresponding to the first winding body and a second magnetic pole portion corresponding to the second winding body, respectively. Different from form 1.

Main points different from the first embodiment will be described with reference to FIG. 20 is an exploded perspective view of a first winding body, a second winding body, and a core portion according to the second embodiment. FIG. FIG. 20 extracts and displays the coils of the stator section.

The electromagnetic actuator according to the second embodiment shown in FIG. 20 has a first winding body 24 and a second winding body 25. As shown in FIG. The first winding body 24 has the same configuration as the first winding body 14 according to the first embodiment, and coils are connected in series in the right spiral direction. The second winding body 25 has a cylindrical shape similar to that of the first winding body 24 and is coaxially arranged in a row with the first winding body 24 . The coils of the second winding body 25 are connected in series in the left spiral direction. Although not shown, the yoke plates of the first winding body 24 and the second winding body 25 can be made smaller in diameter than the yoke unit 121 according to the first embodiment. Also, the yoke plate used for the first winding body 24 and the yoke plate used for the second winding body 25 may be the same.

The electromagnetic actuator according to the second embodiment shown in FIG. 20 has core portions 21 . The core portion 21 has a shaft 111, a first magnetic pole portion 13R and a second magnetic pole portion 13L. The first magnetic pole portion 13R is a magnetic pole portion corresponding to the first winding body 24, and the second magnetic pole portion 13L is a magnetic pole portion corresponding to the second winding body 25. As shown in FIG. The first magnetic pole portion 13R and the second magnetic pole portion 13L are fixed to the shaft 111, respectively. The first magnetic pole portion 13R and the second magnetic pole portion 13L each have the same configuration as the magnetic pole portion 13 according to the first embodiment.

As described above, according to the second embodiment, it is possible to provide a two-degree-of-freedom electromagnetic actuator that is easy to assemble, has high efficiency, and is compact in the radial direction.

<Embodiment 3>
Next, Embodiment 3 will be described with reference to FIGS. Embodiment 3 differs from Embodiment 1 in the form of the stator section.

21 is an exploded perspective view of a core portion and a stator portion according to a third embodiment; FIG. The stator portion 32 has a first winding body 34 and a second winding body 35 .

22 is a perspective view of a first winding body according to a third embodiment; FIG. A first winding body 34 according to the third embodiment differs from that of the first embodiment in that it has spiral conductors instead of multiple coils. As shown in the figure, the first winding body 34 is formed by processing a conductive wire having a rectangular cross section into a right-handed spiral so as to correspond to a cylindrical surface having a reference axis A as a central axis. The first winding bodies 34 are arranged adjacent to each other so that the conducting wire 34U corresponding to the U phase, the conducting wire 34V corresponding to the V phase, and the conducting wire 34W corresponding to the W phase are not energized with each other.

23 is a perspective view of a second winding body according to a third embodiment; FIG. As with the first winding body 34, the second winding body 35 according to the third embodiment is formed by processing a conductive wire having a rectangular cross section into a cylindrical shape, and has a cylindrical surface with the reference axis A as the central axis. Correspondingly, it is processed into a left-handed spiral shape. The second winding bodies 35 are arranged adjacent to each other so that the conducting wire 35U corresponding to the U phase, the conducting wire 35V corresponding to the V phase, and the conducting wire 35W corresponding to the W phase are not energized with each other.

24 is a perspective view of a first winding body and a second winding body according to a third embodiment; FIG. As shown in the figure, in the electromagnetic actuator according to the third embodiment, the second winding body 35 is arranged on the outer peripheral side of the first winding body 34 . As a result, the first winding body 34 can apply a magnetomotive force in the left-hand spiral direction perpendicular to the right-hand spiral direction to the magnetic pole portion 13 . Similarly, the second winding body 35 can provide a right spiral magnetomotive force. Therefore, the electromagnetic actuator according to this embodiment can constitute an electromagnetic actuator having two degrees of freedom. As described above, according to the embodiment, it is possible to provide an electromagnetic actuator having an IPM type magnetic pole portion which is easy to assemble.

It should be noted that the present invention is not limited to the above embodiments, and can be modified as appropriate without departing from the scope of the invention.

10 Electromagnetic actuators 11, 21 Core portions 12, 32 Stator portion 13 Magnetic pole portion 111 Shaft 112 Engaging member 121 Yoke unit 122 Back yoke 123 Coil yoke 124 Teeth 125 Yoke connecting portion 130 Magnetic pole unit 131 Magnet holding portion 132 Air gap 133 Magnet 134 Positioning portion 135 Magnetic flux barrier portion 136 Magnetic flux guide portion 137 Magnetic flux coupling portion 300 Control circuit 310 Driver circuit 320 Position estimation circuit 321 High-pass filter 322 Ammeter 323 Arithmetic circuit A Reference axis Φd, Φq Magnetic flux

Claims (19)

A first winding body including a first conductor wire extending in a first spiral direction centered on a reference axis and a first winding body extending in a second spiral direction centered on the reference axis and intersecting with the first spiral direction a stator having a second winding body including two conductors;
facing at least part of the stator in a radial direction perpendicular to the reference axis, relatively movable with respect to the stator in an axial direction along the reference axis, and circumferentially centered on the reference axis a mover relatively rotatable in a direction,
The mover includes a first magnet group in which different magnetic poles are alternately arranged in the circumferential direction;
a second magnet group arranged downstream of the first magnet group in the axial direction and having different magnetic poles alternately arranged in the circumferential direction;
a first magnet holding portion that holds the first magnet group so that the first magnet group is embedded and has a magnetic permeability higher than that of air;
The second magnet group is held so that the second magnet group is embedded, the magnetic poles of the first magnet group and the magnetic poles of the second magnet group adjacent in the axial direction are arranged so as to be different, and air is provided. a second magnet holder having a higher magnetic permeability;
a magnetic flux barrier portion disposed between the first magnet group and the second magnet group in the axial direction and having a lower magnetic permeability than the first magnet holding portion and the second magnet holding portion;
Embedded magnet type motor. The magnetic flux barrier section is formed in a cylindrical shape,
The embedded magnet type motor according to claim 1. The magnetic flux barrier section has a first magnetic flux barrier section and a second magnetic flux barrier section arranged side by side in the axial direction,
an intermediate portion of the mover disposed between the first magnetic flux barrier portion and the second magnetic flux barrier portion in the axial direction and having a magnetic permeability higher than that of the first magnetic flux barrier portion and the second magnetic flux barrier portion;
It is connected to the first magnet holding portion and the intermediate portion, and is arranged so as to sandwich the first magnetic flux barrier portion between at least one of the first winding body and the second winding body in the radial direction. , a first magnetic flux coupling portion having a higher magnetic permeability than the first magnetic flux barrier portion;
It is connected to the second magnet holding portion and the intermediate portion, and is arranged so as to sandwich the second magnetic flux barrier portion between at least one of the first winding body and the second winding body in the radial direction. , a second magnetic flux coupling portion having a higher magnetic permeability than the second magnetic flux barrier portion;
The embedded magnet type motor according to claim 1 or 2. The intermediate portion is formed in a cylindrical shape,
The embedded magnet type motor according to claim 3. At least one of the first magnetic flux coupling portion and the second magnetic flux coupling portion is formed in a cylindrical shape,
The embedded magnet type motor according to claim 3 or 4. The intermediate portion and at least one of the first magnetic flux coupling portion and the second magnetic flux coupling portion are integrally formed,
The embedded magnet type motor according to any one of claims 3 to 5. the mover is disposed upstream of the first magnet group in the axial direction and has a magnetic permeability lower than that of the first magnet holding portion; and
a third magnetic flux guide portion arranged upstream of the third magnetic flux barrier portion in the axial direction and having a magnetic permeability higher than that of the third magnetic flux barrier portion;
The third magnetic flux barrier section is connected to the first magnet holding section and the third magnetic flux guide section and sandwiched between at least one of the first winding body and the second winding body in the radial direction. and a third magnetic flux coupling portion having a magnetic permeability higher than that of the third magnetic flux barrier portion.
The embedded magnet type motor according to any one of claims 3 to 6. At least one of the third magnetic flux barrier portion, the third magnetic flux guide portion, and the third magnetic flux coupling portion is formed in a cylindrical shape,
The embedded magnet type motor according to claim 7. the mover is disposed downstream of the second magnet group in the axial direction, and has a fourth magnetic flux barrier portion having a lower magnetic permeability than the second magnet holding portion;
a fourth magnetic flux guide portion arranged downstream of the fourth magnetic flux barrier portion in the axial direction and having a magnetic permeability higher than that of the fourth magnetic flux barrier portion;
The fourth magnetic flux barrier section is connected to the second magnet holding section and the fourth magnetic flux guide section, and is sandwiched between at least one of the first winding body and the second winding body in the radial direction. and a fourth magnetic flux coupling portion having a magnetic permeability higher than that of the fourth magnetic flux barrier portion.
The embedded magnet type motor according to any one of claims 3 to 8. At least one of the fourth magnetic flux barrier portion, the fourth magnetic flux guide portion, and the fourth magnetic flux coupling portion is formed in a cylindrical shape,
The embedded magnet type motor according to claim 9. The stator is wound with a conductor wire that constitutes the first winding body or the second winding body, and the conductor wires that constitute the first winding body are connected to each other in the axial direction, Having a plurality of yoke units in which the conductors constituting the second winding body are connected to each other,
The embedded magnet type motor according to any one of claims 1 to 10. the plurality of yoke units each have the same shape when projected in the axial direction;
The embedded magnet type motor according to claim 11. The first winding body has a plurality of first conductor members extending in parallel in an insulated state along the first spiral direction,
The second conductor has a plurality of second conductor members extending in parallel in an insulated state along the second spiral direction,
The embedded magnet type motor according to claim 11 or 12. The mover is arranged radially inner than the stator,
The embedded magnet type motor according to any one of claims 1 to 13. The first winding body is arranged between the second winding body and the mover in the radial direction,
The embedded magnet type motor according to any one of claims 1 to 14. The second winding body is arranged downstream of the first winding body in the axial direction,
The embedded magnet type motor according to any one of claims 1 to 14. a driver circuit that applies a position estimation signal having a position estimation frequency higher than a drive AC voltage to the first winding body and the second winding body;
a filter circuit for detecting the position estimation signal from currents flowing through the first winding body and the second winding body;
an ammeter that measures the current value of the detected position estimation signal;
17. The arithmetic circuit for estimating the relative positional relationship between the first winding body or the second winding body and the mover based on the current value. The embedded magnet type motor according to the item. A first winding body including a first conductor extending in a first spiral direction centered on a reference axis, and a second conductor intersecting the first spiral direction and extending in a second spiral direction centered on the reference axis. a stator having a second winding body including
a movable element relatively movable in a linear direction along the reference axis and relatively rotatable in a circumferential direction about the reference axis with respect to the stator; , a position estimation device for estimating the relative positional relationship between the stator and the mover,
a driver circuit that applies a position estimation signal having a position estimation frequency higher than a driving alternating current to the first winding body and the second winding body;
a filter circuit for detecting the position estimation signal from currents flowing through the first winding body and the second winding body;
an ammeter that measures the current value of the detected position estimation signal;
and an arithmetic circuit for estimating a relative positional relationship between the first winding body or the second winding body and the mover based on the current value. A first winding body including a first conductor extending in a first spiral direction centered on a reference axis, and a second conductor intersecting the first spiral direction and extending in a second spiral direction centered on the reference axis. a stator having a second winding body including
a movable element relatively movable in a linear direction along the reference axis and relatively rotatable in a circumferential direction about the reference axis with respect to the stator; , a position estimation method for estimating the relative positional relationship between the stator and the mover,
an application step of applying a position estimation voltage having a position estimation frequency higher than that of the driving alternating current to the first winding body and the second winding body;
a filtering step for detecting the position estimation current of the position estimation frequency from the currents flowing through the first winding body and the second winding body;
a current measurement step of measuring a current value of the detected position estimation current;
and an estimating step of estimating a relative positional relationship between the first winding body or the second winding body and the mover based on the current value.

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