WO2020085162A1

WO2020085162A1 - Magnetic power transmission structure

Info

Publication number: WO2020085162A1
Application number: PCT/JP2019/040626
Authority: WO
Inventors: 佳弘仲田; 石黒　浩; 平田　勝弘; 酒井　昌彦; 明部矢; 阿部　哲也
Original assignee: 国立大学法人大阪大学
Priority date: 2018-10-26
Filing date: 2019-10-16
Publication date: 2020-04-30
Also published as: JP7349160B2; JPWO2020085162A1

Abstract

A magnetic power transmission structure according to one aspect of the present invention is provided with a shaft member extending along an axial direction, and a cylindrical member having a hollow part passing through in the axial direction and an inner peripheral surface, the shaft member being inserted into the hollow part. Provided to an outer peripheral surface of the shaft member is a protuberance that protrudes diametrically outward and that is formed encircling the axis in a spiral formation. Provided to the inner peripheral surface of the cylindrical member are: a protruding unit that includes a protrusion protruding diametrically inward; and a magnet that is arranged so as to be adjacent to the protruding unit while encircling the axis, and that includes a first surface facing the protuberance and a second surface facing the first surface. The first surface of the magnet is magnetized to a first magnetic pole, and the second surface of the magnet is magnetized to a second magnetic pole opposite to the first magnetic pole.

Description

Magnetic power transmission structure

The present invention relates to the technology of a magnetic power transmission structure.

▽ Conventionally, the feed screw mechanism is known as a mechanism that converts rotational motion into translational motion. The lead screw mechanism is a mechanical element indispensable for driving and positioning an object, and is widely used in various applications. A general feed screw mechanism includes a screw and a nut, and is configured such that when either one is rotated, the other is propelled.

Machine tools often use a ball screw mechanism that reduces friction and improves efficiency by inserting a ball between the screw shaft and nut. In recent years, robots that combine this ball screw mechanism and a motor have been used. Actuators have also been developed. However, since a general feed screw mechanism and a ball screw mechanism transmit power by a contact force, they have problems such as generation of vibration and noise and heat generation due to friction.

To solve this problem, a magnetic screw mechanism that transmits power using magnetic force has been proposed. In the magnetic screw mechanism, power can be transmitted in a non-contact manner between the screw and the nut by using magnetic force. That is, it is possible to prevent friction between the screw and the nut when transmitting power. Therefore, according to the magnetic screw mechanism, it is possible to solve the above problems, improve the power transmission efficiency, and realize high-speed driving.

Also, this magnetic screw mechanism has the flexibility of an external force against the external force due to its magnetic properties. Therefore, according to the magnetic screw mechanism, it is possible to ensure safety at the time of contact by performing step-out at the time of overload. Therefore, in recent years, it is particularly expected to be applied as a drive source for the next-generation industrial robots and service robots that work together with humans.

Publication of JP-A-2016-025700 Japanese Patent Laid-Open No. 11-031615 International Publication No. 2018/092906

Patent Document 1 proposes a magnetic screw actuator including a magnetic nut and a magnetic screw as an example of the magnetic screw mechanism. In this magnetic screw actuator, a magnetic screw having two spiral magnetic poles of different polarities is used, but it is difficult to manufacture such a spirally magnetized magnetic screw. Further, the intermediate rotor of the magnetic nut is an annular body in which a large number of magnetic poles of S poles and N poles are alternately arranged, and each magnetic pole is formed by a magnet piece magnetized in the radial direction. . Therefore, a large number of magnet pieces are used to form the intermediate rotor, which increases the manufacturing cost. For these reasons, the magnetic screw mechanism proposed in Patent Document 1 has a problem of poor productivity.

On the other hand, Patent Document 2 proposes a method of forming a magnetic nut with a plurality of ring-shaped magnets and a yoke with a thread formed on the inner peripheral surface. According to this method, the magnetic nut can be manufactured without using many magnet pieces, so that the manufacturing cost of the magnetic screw mechanism can be suppressed. However, in the method proposed in Patent Document 2, a plurality of link-shaped magnets are arranged at intervals in the axial direction, and a yoke is arranged between adjacent magnets. Therefore, if a back yoke is arranged outside the radial direction of the magnetic screw as a magnetic shield, a closed magnetic circuit is formed between each magnet and the back yoke, and the magnetic force of the magnet acts on the screw shaft side. It becomes difficult and the thrust of the magnetic screw mechanism drops. Further, since the machining accuracy of the magnet is lower than the machining accuracy of the yoke, there is a gap between the adjacent yokes, and the screw threads of the screw shaft correspond to the screw threads of each yoke with high accuracy. Was difficult. For these reasons, the magnetic screw mechanism proposed in Patent Document 2 has a problem of poor practicality.

On the other hand, in Patent Document 3, a cylindrical member configured by a plurality of magnets that are arranged so as to be divided around the axis and a plurality of magnetic pole members that are respectively arranged inside in the radial direction corresponding to each magnet, A magnetic power transmission structure including a shaft member that is inserted into the hollow portion of the tubular member has been proposed. Specifically, in the magnetic power transmission structure, the plurality of magnets include a magnet having an N pole on the inner side in the radial direction and a magnet having an S pole on the inner side in the radial direction. The surface of is provided with protrusions along different spirals depending on the magnet to be magnetized. On the outer peripheral surface of the shaft member, a spiral ridge corresponding to each spiral is provided. In the magnetic power transmission structure, by rotating either one of the tubular member and the shaft member, the positional relationship between each protrusion and each ridge is shifted in the translational direction to generate a magnetic force in the translational direction. , Which allows the other to be translated.

In the magnetic power transmission structure, the magnetic pole members are magnetized by the magnets divided around the shaft so that the protrusions of the magnetic pole members can be used as magnetic poles. Therefore, one magnet can form a plurality of magnetic poles, and it is not necessary to prepare a magnet for each magnetic pole. Further, by appropriately processing each magnetic pole member to form the protrusion, the magnetic pole can be easily provided on each magnetic pole member. Therefore, according to Patent Document 3, since the number of magnets to be used can be reduced with respect to the number of magnetic poles to be formed and each magnetic pole can be easily formed, the magnetic screw mechanism with high productivity can be obtained. Can be provided. In addition, in the magnetic power transmission structure, the magnets and the magnetic pole members are arranged not in the axial direction but in the radial direction. The deviation can be prevented. Further, even if the back yoke is arranged on the outer side in the radial direction of the tubular member, a closed magnetic circuit does not occur between each magnet and the back yoke, and a magnetic circuit including each magnetic pole member is formed. The thrust of the mechanism does not decrease. Therefore, according to Patent Document 3, it is possible to provide a highly practical magnetic screw mechanism.

However, the present inventors have found that the magnetic screw mechanism proposed in Patent Document 3 has the following problems. That is, in the tubular member, in order to magnetize each magnetic pole member, each magnet is arranged on the outer side in the radial direction of each magnetic pole member. The machining accuracy of this magnet is lower than that of the material of the magnetic pole member (for example, electromagnetic soft iron, silicon steel, amorphous magnetic alloy, etc.), and in one example, a deviation of about 0.1 mm occurs between the magnets. Therefore, even if each magnetic pole member is manufactured with high precision, the positional deviation of each magnetic pole member around the axis is likely to be affected by the dimensional error of each magnet. Therefore, it is difficult to control the dimensional accuracy of the distance between each protrusion of each magnetic pole member and each protrusion of the shaft member. Due to this, the performance of the magnetic screw mechanism may easily vary. In addition, since the number of magnets used tends to increase relatively, there is a problem that the number of parts tends to increase.

In one aspect, the present invention has been made in view of such circumstances, and an object thereof is to provide a magnetic screw mechanism having a simpler structure and easy to manage dimensional accuracy.

The present invention adopts the following configurations in order to solve the above problems.

That is, a magnetic power transmission structure according to one aspect of the present invention has a shaft member and an outer peripheral surface, a shaft member extending along the axial direction, and a cylinder having a hollow portion penetrating in the axial direction and an inner peripheral surface. A tubular member, into which the shaft member is inserted in the hollow portion, wherein the outer peripheral surface of the shaft member is a ridge protruding outward in the radial direction of the shaft. A protruding unit provided with a spiral formed around the shaft, the inner peripheral surface of the tubular member including a protruding unit protruding inward in the radial direction, the protruding unit and the shaft. A magnet including a first surface facing the ridge and a second surface facing the first surface, the magnet being disposed so as to be adjacent to each other around the ridge, and the first surface of the magnet is a first surface. Is magnetized to a magnetic pole, and the second surface of the magnet has a second surface opposite to the first magnetic pole. It is magnetized to the magnetic pole.

In the above configuration, the outer peripheral surface of the shaft member extending in the axial direction is a ridge protruding outward in the radial direction, and is provided with a ridge formed in a spiral shape around the axis. On the other hand, the inner peripheral surface of the tubular member into which the shaft member is inserted is disposed so as to be adjacent to the convex unit including the convex portion protruding inward in the radial direction and the convex unit around the axis, and And a magnet including a first surface facing the first surface and a second surface facing the first surface. The first surface of the magnet is magnetized to the first magnetic pole, and the second surface is magnetized to the second magnetic pole opposite to the first magnetic pole. That is, when the first surface is magnetized to the N pole, the second surface is magnetized to the S pole, and when the first surface is magnetized to the S pole, the second surface is magnetized to the N pole. Be magnetized.

Accordingly, in the above-described configuration, since the protrusion of the shaft member is formed in a spiral shape, the protrusion of the shaft member is translated in the translational direction (that is, the shaft by rotating either one of the tubular member and the shaft member). Direction). Further, the magnetic flux generated from the magnet passes through the shaft member (projection), the convex unit (projection), and the tubular member at the portion where the convex portion of the tubular member and the projecting strip of the shaft member face each other. Then, a magnetic circuit that returns to the magnet is formed (the direction of the magnetic flux depends on the polarity of each surface). That is, by arranging the convex unit and the magnet adjacent to each other on the inner peripheral surface of the tubular member, the convex unit serves as a consequent pole, and the magnetic circuit is formed in the shaft member, the magnet, the convex unit, and the tubular member. Form. Due to this magnetic circuit, a magnetic force is generated in which the convex portion of the tubular member and the ridge of the shaft member attract each other. Therefore, when one of the tubular member and the shaft member is rotated to shift the projection of the shaft member in the translational direction with respect to the tubular member, the convex portion of the tubular member causes the projection of the shaft member to project. The other can be moved so as to maintain the state of facing each other. For example, when the shaft member is rotated, the tubular member can be moved in the translational direction so as to follow the deviation of the protrusion of the shaft member. Therefore, the magnetic power transmission structure according to the above configuration can operate as a magnetic screw mechanism.

In the magnetic power transmission structure according to the above configuration, the magnet for forming the magnetic circuit is not arranged radially outside the convex unit, but is arranged adjacent to the convex unit around the axis. Therefore, the influence of the dimensional error of the magnet can be prevented from affecting the dimensional accuracy of the distance between the convex portion of the convex unit (cylindrical member) and the protrusion of the shaft member. That is, according to the above configuration, the dimensional accuracy of the distance between the convex portion of the convex unit and the ridge of the shaft member can be controlled while ignoring the dimensional error of the magnet. In addition, in the above-described configuration, it is sufficient to dispose either the convex unit or the magnet on the outer side in the radial direction when viewed from the shaft member, rather than disposing both the convex unit and the magnet. be able to. Therefore, according to the above configuration, it is possible to provide a magnetic screw mechanism having a simpler structure and easy to control the dimensional accuracy. As a result, it is possible to mass-produce a magnetic screw mechanism that is cheaper and has high practicality while suppressing variations in performance.

Note that "around the axis" refers to the rotation direction (circumferential direction) around the axis. Further, the “radial direction” refers to the direction of a plane perpendicular to the axial direction (that is, the direction of the radius of the circle centered on the axis). The term “spiral” broadly includes shapes that can be drawn by translating in the axial direction while rotating around the axis. That is, “spiral” refers to a shape in which a point on a tangent line parallel to the axis shifts in either direction when rotated around the axis. The "magnet" may be a permanent magnet or an electromagnet formed by a coil. The magnet may be skew magnetized. The number of protrusions of the shaft member may be one, or two or more. The number of ridges of the shaft member may not be particularly limited and may be appropriately selected according to the embodiment. At least a portion of the tubular member through which the magnetic flux passes (including the convex unit) and at least a portion of the shaft member through which the magnetic flux passes are made of a magnetic material (hereinafter, also referred to as “magnetic material”).

In the magnetic power transmission structure according to the one aspect, a plurality of the convex portions of the convex unit may be provided, and the plurality of convex portions of the convex unit may be arranged apart from each other in the axial direction. . With this configuration, it is possible to provide a magnetic screw mechanism with higher output. The respective convex portions of the convex unit may be arranged so as to correspond to the axial arrangement of the protrusions of the shaft member. That is, the interval between the protrusions in the axial direction may match the interval between the protrusions in the axial direction. However, the arrangement of the protrusions in the protrusion unit is not limited to this example, and the interval between the protrusions in the axial direction does not have to match the interval between the protrusions in the axial direction. The number of convex portions in the convex unit is not particularly limited and may be appropriately selected according to the embodiment.

In the magnetic power transmission structure according to the one aspect, the convex unit may have a concave portion provided between the convex portions adjacent to each other in the axial direction, and the concave portion of the convex unit has a non-magnetic portion. The material may be filled. According to this configuration, it is possible to suppress damage to the convex portion of the convex unit.

In the magnetic power transmission structure according to the one aspect, the convex unit may be integrally formed on the inner peripheral surface of the tubular member. According to this configuration, the number of parts can be further suppressed, and thus a magnetic screw mechanism having a simpler structure can be provided.

In the magnetic power transmission structure according to the one aspect, the first surface of the magnet may include a convex portion that protrudes inward in the radial direction. With this configuration, it is possible to provide a magnetic screw mechanism with higher output.

In the magnetic power transmission structure according to the above aspect, a plurality of the convex portions of the magnet may be provided, and the plurality of convex portions of the magnet may be arranged apart from each other in the axial direction. With this configuration, it is possible to provide a magnetic screw mechanism with higher output. In addition, each convex part of a magnet may be arrange | positioned so that it may correspond in the axial direction of the protrusion of a shaft member. That is, the interval between the protrusions in the axial direction may match the interval between the protrusions in the axial direction. However, the arrangement of the protrusions in the magnet may not be limited to such an example, and the interval between the protrusions in the axial direction may not match the interval between the protrusions in the axial direction. The number of convex portions in the magnet may not be particularly limited and may be appropriately selected according to the embodiment.

In the magnetic power transmission structure according to the one aspect, a plurality of the convex units may be provided, a plurality of the magnets may be provided, and the respective convex units are arranged with a space around the axis. Well, the inner peripheral surface of the tubular member may further be provided with a plurality of groove portions respectively arranged between the pair of convex units adjacent to each other around the axis, and each magnet may be provided with each groove portion. May be located at. With this configuration, it is possible to provide a magnetic screw mechanism with higher output.

In the magnetic power transmission structure according to the one aspect, the outer peripheral surface of the shaft member may be provided with a recessed portion arranged between the protrusions in the axial direction, and the recessed portion of the shaft member may be provided. May be filled with a non-magnetic material. According to this configuration, by filling the concave portion with the non-magnetic material, it is possible to reduce the possibility that the protrusion of the shaft member will be damaged.

The magnetic power transmission structure according to the one aspect further includes a first covering member that is arranged radially inward of the inner peripheral surface of the tubular member and that covers the convex unit of the tubular member. Good. According to this configuration, the protrusion of the convex unit is covered with the first covering member with respect to the protrusion of the shaft member, so that contact between the protrusion of the shaft member and the protrusion of the convex unit can be suppressed. . Therefore, it is possible to reduce the possibility that the convex portion of the convex unit is damaged.

The magnetic power transmission structure according to the one aspect may further include a second covering member that is arranged radially outside the outer peripheral surface of the shaft member and that covers the protrusion of the shaft member. According to this structure, the protrusion of the shaft unit is covered with the second coating member on the protrusion of the convex unit, so that contact between the protrusion of the shaft member and the protrusion of the convex unit can be suppressed. . Therefore, it is possible to reduce the possibility that the protrusion of the shaft member will be damaged.

A magnetic power transmission structure according to one aspect of the present invention has a shaft and an outer peripheral surface, a shaft member extending along the axial direction, and a cylinder having a hollow portion and an inner peripheral surface penetrating in the axial direction. A tubular member, into which the shaft member is inserted in the hollow portion, wherein the outer peripheral surface of the shaft member is a ridge protruding outward in the radial direction of the shaft. A protrusion formed in a spiral shape around the axis is provided, and the inner peripheral surface of the tubular member includes protrusions protruding inward in the radial direction, and arranged apart from each other around the axis. A plurality of convex units, a plurality of groove portions respectively disposed between the pair of convex units adjacent to each other around the axis, and arranged in each of the groove portions, and face one of the pair of convex units And a first surface facing the first surface, A plurality of magnets each including a second surface facing the other of the convex units of the above-mentioned convex unit, the first surface of each magnet being magnetized to a first magnetic pole, and the first surface of each magnet being The two surfaces are magnetized by a second magnetic pole which is opposite to the first magnetic pole. In the magnetic power transmission structure according to this configuration, each magnet is arranged between the adjacent convex units. As a result, while the convex portion of each convex unit faces the protrusion of the shaft member, the magnetic flux generated from each magnet causes one convex unit (convex portion), the shaft member (protrusion), and the other convex unit. A magnetic circuit is formed that passes through the (convex portion) and returns to each magnet (the direction of the magnetic flux depends on the polarity of each surface). Except for the configuration of the magnetic circuit, the magnetic power transmission structure according to the present configuration operates in the same manner as the magnetic power transmission structure according to the above configuration, and the effects can be obtained. Therefore, according to the said structure, a magnetic screw mechanism with a simpler structure and whose dimensional accuracy is easy to manage can be provided.

In the magnetic power transmission structure according to the one aspect, a plurality of the convex portions of each convex unit may be provided, and the plurality of convex portions of each convex unit are arranged apart from each other in the axial direction. You may With this configuration, it is possible to provide a magnetic screw mechanism with higher output. Note that the arrangement and number of the convex portions of each convex unit may be the same as in the above configuration.

Further, an actuator according to one aspect of the present invention, a magnetic power transmission structure according to any one of the above, a rotating device for rotating the tubular member or the shaft member of the magnetic power transmission structure, Equipped with. With this configuration, it is possible to provide an actuator that uses a magnetic screw mechanism that has a simpler structure and whose dimensional accuracy is easy to control.

The actuator according to the one aspect may further include a position sensor configured to be able to measure the position of the tubular member, and a control device, wherein the control device is the tubular device obtained by the position sensor. The rotating device may be driven so that the tubular member moves to a desired position based on the information on the position of the member. According to this configuration, it is possible to control the position of the actuator.

The actuator according to the one aspect further includes a position sensor configured to measure the position of the tubular member, a rotation sensor configured to measure the inclination of the shaft member, and a control device. Often, the control device generates a desired force in the tubular member based on information on the position of the tubular member obtained by the position sensor and information on the inclination of the shaft member obtained by the rotation sensor. Thus, the rotating device may be driven. With this configuration, output control of the actuator can be performed. The inclination of the shaft member means the rotation angle of the shaft member, that is, the angle around the axis of the shaft member with respect to the tubular member.

The actuator according to the one aspect further includes a position sensor configured to measure the position of the tubular member, a rotation sensor configured to measure the inclination of the shaft member, and a control device. Often, the control device is configured such that the tubular force is obtained in a state in which a desired force is obtained, based on information on the position of the tubular member obtained by the position sensor and information on the inclination of the shaft member obtained by the rotation sensor. The rotating device may be driven to move the member to a desired position. With this configuration, output control of the actuator can be performed.

According to the present invention, it is possible to provide a magnetic screw mechanism having a simpler structure and easy to control dimensional accuracy.

FIG. 1 is an exploded view schematically illustrating a magnetic power transmission structure according to an embodiment. FIG. 2 is a perspective view schematically illustrating the magnetic power transmission structure according to the embodiment. FIG. 3 is a cross-sectional view schematically illustrating a cross section along the axial direction of the magnetic power transmission structure according to the embodiment. FIG. 4 is a partially cutaway perspective sectional view schematically illustrating the magnetic power transmission structure according to the embodiment. FIG. 5 schematically illustrates a state in which the tubular member of the magnetic power transmission structure according to the embodiment is viewed along the axial direction. FIG. 6 is a partial cross-sectional perspective view for explaining the operation principle of the magnetic power transmission structure according to the embodiment. FIG. 7 is a development view for explaining the operation principle of the magnetic power transmission structure according to the embodiment. FIG. 8 is a diagram for explaining the operation principle of the magnetic power transmission structure according to the embodiment, and is a diagram schematically illustrating a state in which the magnetic power transmission structure is viewed along the axial direction. Is. 9A is a partial cross-sectional view taken along the line A1-A1 of FIG. 9B is a partial cross-sectional view taken along the line B1-B1 of FIG. FIG. 10 schematically illustrates the actuator according to the embodiment. FIG. 11 schematically illustrates the hardware configuration of the control device according to the embodiment. FIG. 12A illustrates the relationship between the position of the cylindrical member and the output when the inclination of the shaft member is constant. FIG. 12B illustrates the relationship between the inclination of the shaft member and the output when the position of the tubular member is constant. FIG. 12C illustrates an example of correspondence data according to the embodiment. FIG. 13 schematically illustrates a software configuration of the control device according to the embodiment. FIG. 14 illustrates an example of control of the actuator by the control device according to the embodiment. FIG. 15 illustrates an example of actuator control by the control device according to the embodiment. FIG. 16 illustrates an example of actuator control performed by the control device according to the embodiment. FIG. 17A illustrates an example of the magnetization direction of each magnet. FIG. 17B illustrates an example of the magnetization direction of each magnet. FIG. 18 schematically illustrates a state in which the magnetic power transmission structure according to the modification is viewed along the axial direction. FIG. 19 is a partial cross-sectional view schematically illustrating the magnetic power transmission structure according to the modification. FIG. 20 is a partial cross-sectional view schematically illustrating the magnetic power transmission structure according to the modification. FIG. 21 is a partial cross-sectional view schematically illustrating the magnetic power transmission structure according to the modification. FIG. 22A illustrates an example of the shape of the concave portion of the convex unit. FIG. 22B illustrates an example of the shape of the concave portion of the convex unit. FIG. 23 illustrates an example of the shape of each magnet.

Hereinafter, an embodiment according to one aspect of the present invention (hereinafter, also referred to as “this embodiment”) will be described with reference to the drawings. However, the present embodiment described below is merely an example of the present invention in all respects. Various modifications or changes may be made without departing from the scope of the present invention. That is, in implementing the present invention, a specific configuration according to the embodiment may be appropriately adopted. Note that, in the following description, for convenience of description, the description will be given based on the orientation in the drawing.

§1 Configuration Example First, the configuration of the magnetic power transmission structure 1 according to the present embodiment will be described with reference to FIGS. 1 to 4. FIG. 1 is an exploded view schematically illustrating a magnetic power transmission structure 1 according to this embodiment. FIG. 2 is a perspective view schematically illustrating the magnetic power transmission structure 1 according to this embodiment. FIG. 3 schematically illustrates a cross section along the axial direction of the magnetic power transmission structure 1 according to this embodiment. FIG. 4 is a partially cutaway perspective sectional view schematically illustrating the magnetic power transmission structure 1 according to the present embodiment.

As shown in each drawing, the magnetic power transmission structure 1 according to the present embodiment has a shaft 31 and penetrates in the axial direction with a shaft member 3 extending along the axial direction (the left-right direction in FIG. 3). The tubular member 2 has a hollow portion 21, and the shaft member 3 is inserted into the hollow portion 21. The tubular member 2 corresponds to the nut of the magnetic screw mechanism, and the shaft member 3 corresponds to the screw of the magnetic screw mechanism. Accordingly, the magnetic power transmission structure 1 according to the present embodiment can be used as a magnetic screw that converts rotational movement into translational movement. Hereinafter, each component will be described.

[Shaft member]
First, the shaft member 3 will be described. In this embodiment, the shaft member 3 includes a main body portion 30 extending in the axial direction and formed in a cylindrical shape. The main body portion 30 is solid and includes a shaft 31 passing through the center and an outer peripheral surface 32 that is an outer surface. Thus, in the present embodiment, the shaft member 3 has the shaft 31 and the outer peripheral surface 32 and is configured to extend along the axial direction.

The outer peripheral surface 32 of the shaft member 3 is provided with a ridge 33 that projects radially outward of the shaft 31 and that is formed spirally around the axis. "Around the axis" refers to the rotation direction (circumferential direction) about the axis 31. The radial direction refers to the direction of a plane perpendicular to the axial direction (that is, the direction of the radius of the circle centering on the axis 31). The spiral shape broadly includes a shape that can be drawn by translating in the axial direction while rotating around the axis. That is, the spiral shape refers to a shape in which a point on a tangent line parallel to the axis 31 shifts in either direction when rotated around the axis.

As shown in each drawing, in this embodiment, the number of the protrusions 33 of the shaft member 3 is one. In addition, in the present embodiment, the protrusion 33 continuously extends from one end to the other end in the axial direction. The axial range in which the protrusion 33 is provided may be appropriately determined according to the embodiment. As shown in FIG. 3, in the range where the protrusions 33 are provided on the outer peripheral surface 32 of the shaft member 3, there are provided recesses 35 arranged between the protrusions 33 in the axial direction. The shapes and dimensions of the protrusions 33 and the recesses 35 may not be particularly limited and may be appropriately determined according to the embodiment. In the present embodiment, the protrusion 33 is formed in a rectangular cross section.

Such a shaft member 3 can be manufactured using a magnetic material. As the material of the shaft member 3, for example, a soft magnetic material (electromagnetic soft iron, silicon steel, amorphous magnetic alloy, etc.), carbon steel or the like can be used as a magnetic material. As an example of a manufacturing method, for example, a columnar magnetic material is prepared, and the outer peripheral surface of the prepared magnetic material is appropriately cut, so that the shaft member 3 having the protrusions 33 can be manufactured. A known ball screw may be used for the shaft member 3. Thereby, the manufacturing cost of the magnetic power transmission structure 1 can be suppressed.

[Cylindrical member]
Next, the tubular member 2 will be described with further reference to FIG. FIG. 5 schematically illustrates a state in which the tubular member 2 according to the present embodiment is viewed along the axial direction.

As shown in each drawing, the tubular member 2 according to the present embodiment includes a cylindrical main body portion 20 extending along the axial direction. The main body portion 20 includes a hollow portion 21 penetrating in the axial direction and an inner peripheral surface 22 that is an inner surface adjacent to the hollow portion 21. Thereby, in this embodiment, the tubular member 2 is configured to have the hollow portion 21 and the inner peripheral surface 22.

In the present embodiment, the inner peripheral surface 22 of the tubular member 2 is provided with a plurality of convex units 23, a plurality of groove portions 24, and a plurality of magnets 25. In the example shown by each figure, two convex units 23, two groove portions 24, and two magnets 25 are provided. The respective convex units 23 are arranged around the axis so as to be separated from each other. Each groove 24 is arranged between a pair of convex units 23 adjacent to each other around the axis. Each magnet 25 is arranged in each groove 24 so as to be adjacent to each convex unit 23 around the axis.

(Convex unit)
Each convex unit 23 has a base portion formed in an arc shape and extending along the axial direction, and a plurality of convex portions 231 projecting radially inward from the inner surface (inner peripheral surface) of the base portion. Is included. The number of the convex portions 231 is not particularly limited and may be appropriately selected according to the embodiment.

In the present embodiment, the convex portions 231 are arranged apart from each other in the axial direction. As shown in FIG. 3, in the present embodiment, the protrusions 231 are arranged so as to correspond to the axial arrangement of the protrusions 33 of the shaft member 3. That is, the interval between the convex portions 231 in the axial direction matches the interval between the protrusions 33 in the axial direction. The inner surface of the base of each convex unit 23 is further provided with a concave portion 232 arranged between the convex portions 231 in the axial direction.

The shapes and dimensions of the convex portions 231 and the concave portions 232 may not be particularly limited and may be appropriately determined according to the embodiment. As shown in FIG. 3, in the present embodiment, the cross section of each convex portion 231 along the axial direction is formed in a rectangular shape. On the other hand, the cross section of each groove 24 is formed in an arc shape. Further, as shown in FIG. 5, the shape of each convex portion 231 when viewed along the axial direction is formed in an arc shape.

Each of the protrusions 231 may be spirally formed around the axis so as to correspond to the protrusion 33 of the shaft member 3, or may be formed to extend along the axis. The axial dimension of each convex unit 23 may be appropriately determined according to the embodiment, and may or may not be the same as the axial dimension of the main body portion 20 of the tubular member 2. Good. For example, each convex unit 23 may be formed shorter than the main body 20 in the axial direction.

Each convex unit 23 is formed using a magnetic material. Similar to the shaft member 3, as the material of each convex unit 23, for example, a soft magnetic material, carbon steel or the like can be used as a magnetic material. Each convex unit 23 can be manufactured by appropriately cutting a magnetic material. In the present embodiment, each convex unit 23 is integrally formed on the inner peripheral surface 22 of the main body portion 20 of the tubular member 2.

(magnet)
On the other hand, each magnet 25 extends in the axial direction and is arranged in each groove 24 formed between the convex units 23. As shown in FIG. 5, the cross section of each magnet 25 perpendicular to the axial direction is formed in an arc shape of approximately 90 degrees. Correspondingly, the cross section of each convex unit 23 is formed in an arc shape having an angle of approximately 90 degrees or slightly smaller than 90 degrees, so that the cross section of each groove portion 24 is the same as each magnet 25 or each magnet 25. It is formed in an arc shape having an angle slightly larger than 25. As a result, each magnet 25 is formed in each groove 24 so as to be adjacent to each convex unit 23 around the axis. The axial dimension of each magnet 25 may be appropriately determined according to the embodiment, and may or may not match the axial dimension of the main body portion 20 of the tubular member 2. Good. For example, each magnet 25 may be formed to be shorter than the main body 20 in the axial direction.

Each magnet 25 includes an inner curved surface 251 facing the inner side in the radial direction and facing the protrusion 33 of the shaft member 3, and an outer curved surface 252 facing the inner curved surface 251. Further, each magnet 25 faces the first side surface 255 and the first side surface 255 that face one of the pair of convex units 23 adjacent to each other around the axis, and faces the other of the pair of convex units 23. The second side surface 256 is included. Each curved surface (251, 252) is smooth and each side surface (255, 256) is flat. That is, in this embodiment, unlike the respective convex units 23, the inner curved surface 251 is not provided with a convex portion.

In the present embodiment, the inner curved surface 251 is magnetized to the first magnetic pole, and the outer curved surface 252 is magnetized to the second magnetic pole opposite to the first magnetic pole. That is, when the inner curved surface 251 is magnetized to the N pole, the outer curved surface 252 is magnetized to the S pole, and when the inner curved surface 251 is magnetized to the S pole, the outer curved surface 252 is magnetized to the N pole. Be magnetized. In both cases, the operating principle of the magnetic power transmission structure 1 is the same. Therefore, hereinafter, for convenience of description, it is assumed that the inner curved surface 251 is magnetized to the S pole and the outer curved surface 252 is magnetized to the N pole, and the description of the other case will be appropriately omitted. The inner curved surface 251 is an example of the “first surface” in the present invention, and the outer curved surface 252 is an example of the “second surface” in the present invention. Each magnet 25 may be a permanent magnet or an electromagnet formed of a coil. Further, each magnet 25 may be skew-magnetized.

(Production method)
Such a tubular member 2 can be manufactured, for example, as follows. That is, a columnar magnetic material for forming the main body 20 is prepared. Like the shaft member 3, the magnetic material to be prepared may be a soft magnetic material, carbon steel, or the like. Next, the prepared magnetic material is appropriately processed to form each convex unit 23 and each groove 24 in the main body 20 together with the hollow portion 21. On the surface of the portion of each convex unit 23, the teeth forming each convex portion 231 are carved by cutting or the like. Then, each magnet 25 is prepared, and each prepared magnet 25 is arranged in each groove 24. Thereby, the tubular member 2 can be manufactured.

In the present embodiment, the inner diameter of the hollow portion 21 of the tubular member 2 including the convex units 23 and the magnets 25 is set to be slightly larger than the outer diameter of the shaft member 3 including the protrusions 33. As a result, the shaft member 3 is inserted into the hollow portion 21 without the protrusions 231 of the tubular member 2 and the magnets 25 interfering with the protrusions 33 of the shaft member 3, and the protrusion units 23 and the magnets 25 are inserted. The protrusions 33 can be arranged radially inward.

Also, in the present embodiment, the axial length of the tubular member 2 is set to be shorter than the axial length of the shaft member 3. Therefore, in the present embodiment, as illustrated in FIGS. 1 to 4, when the shaft member 3 is inserted into the tubular member 2, the shaft member 3 is attached to the shaft member 3 from both sides of the opening of the tubular member 2. The both ends are arranged so as to project.

In the example shown in FIG. 5, each groove portion 24 is slightly larger than each magnet 25, so that a gap is formed between each side surface (255, 256) of each magnet 25 and each convex unit 23. It is provided. However, the dimension of each groove 24 is not limited to such an example, and may be appropriately determined according to the embodiment. For example, the grooves 24 and the magnets 25 may be formed to have substantially the same size so that there is almost no gap between the side surfaces (255, 256) and the convex units 23.

§2 Operation Example Next, an operation example of the magnetic power transmission structure 1 according to the present embodiment will be described with reference to FIGS. 6 to 8, 9A and 9B. FIG. 6 is a partial cross-sectional perspective view for explaining the operation principle of the magnetic power transmission structure 1 according to this embodiment. FIG. 7 is a development view for explaining the operation principle of the magnetic power transmission structure 1 according to this embodiment. FIG. 8 schematically illustrates a state in which the magnetic power transmission structure 1 according to the present embodiment is viewed along the axial direction. 9A is a partial cross-sectional view taken along the line A1-A1 of FIG. 9B is a partial cross-sectional view taken along the line B1-B1 of FIG. In this operation example, for convenience of description, the tubular member 2 is fixed so as not to be rotatable about the axis and capable of translation in the axial direction, and the shaft member 3 is rotatable about the axis and translated in the axial direction. It is assumed to be fixed to be impossible.

In the scenes shown in each drawing, each convex portion 231 formed on each convex unit 23 of the tubular member 2 faces the ridge 33 of the shaft member 3. In this state, the magnetic flux emitted from the outer curved surface 252 of each magnet 25 magnetized to the N pole enters each convex portion 231 of each convex unit 23 via the main body portion 20. The body portion 20 can function as a back yoke (magnetic shield) by being made of a magnetic material. The magnetic flux that has entered each convex portion 231 is emitted from each convex unit 23 and enters the protrusion 33 of the shaft member 3. The magnetic flux that has entered the ridge 33 reaches the portion facing each magnet 25 through the ridge 33 and / or via the shaft, and from this portion, the inside of each magnet 25 magnetized to the S pole. It is emitted toward the curved surface 251.

That is, in the present embodiment, each convex unit 25 and each magnet 25 are arranged adjacent to each other on the inner peripheral surface 22 of the tubular member 2, so that each convex unit 25 becomes a consequent pole. The magnetic flux emitted from each magnet 25 passes through the tubular member 2 (main body portion 20), each convex unit 23 (convex portion 231), and the shaft member 3 (protruding ridge 33) in this order, and then returns to each magnet 25. A return magnetic circuit is formed. As shown in FIG. 7, by this magnetic circuit, the surface of each protrusion 231 acts as an N pole, whereas the portion of the ridge 33 facing each protrusion 231 acts as an S pole. Further, the portion of the ridge 33 facing each magnet 25 acts as an N pole. Even when the inner curved surface 251 is magnetized to the N pole and the outer curved surface 252 is magnetized to the S pole, the magnetic circuit is formed in the same manner as the above although the direction of the magnetic flux is opposite. As a result, in the present embodiment, a magnetic attractive force acts between each convex portion 231 of the tubular member 2 and the protrusion 33 of the shaft member 3. Thus, the tubular member 2 and the shaft member 3 constitute a magnetic screw mechanism.

In this state, when the shaft member 3 is rotated counterclockwise, the protrusions 33 of the shaft member 3 are formed in a spiral shape, so that the shaft member 3 has an axial direction (left and right direction in FIG. 9A) with respect to the tubular member 2. Translate to. In this embodiment, the protrusion 33 is formed in a right spiral. Therefore, in the example of FIG. 9A, the protrusion 33 translates to the right. As a result, the ridge 33 of the shaft member 3 moves so as to be displaced in the axial direction with respect to each convex portion 231 of the tubular member 2. With respect to this movement, the attractive force of each magnet 25 acts so as to maintain the positional relationship between the protrusion 33 and each convex portion 231. Therefore, unless a load exceeding the action of this magnetic force is applied, the tubular member 2 translates in the axial direction by the amount of translation of the protrusion 33. That is, in the example of FIG. 9A, the tubular member 2 translates to the right so as to follow the translation of the ridge 33 to the right.

With the above operation, in the magnetic power transmission structure 1 according to the present embodiment, the tubular member 2 can be translated in the axial direction by rotating the shaft member 3. The rotation direction of the shaft member 3 may not be limited to the counterclockwise direction. The shaft member 3 may be rotated clockwise. When the shaft member 3 is rotated clockwise, in the example of FIG. 9A, the ridge 33 translates leftward, and the tubular member 2 follows the translation of the ridge 33 and translates leftward. That is, the moving direction of the tubular member 2 can be determined by the rotation direction of the shaft member 3.

Also, in the above operation example, it is assumed that the tubular member 2 is fixed so as not to rotate around the axis, and the shaft member 3 is rotatably fixed to the shaft split. However, the fixed state of the tubular member 2 and the shaft member 3 may not be limited to such an example. The tubular member 2 may be fixed rotatably around the axis, and the shaft member 3 may be fixed non-rotatably around the axis. In this case, by rotating the tubular member 2 around the axis, the positional relationship between the tubular member 2 and the shaft member 3 can be shifted in the translational direction (axial direction).

§3 Example of Use Next, as an example of use of the magnetic power transmission structure 1 according to the present embodiment, an actuator using the magnetic power transmission structure 1 will be described with reference to FIG. 10. FIG. 10 schematically illustrates an example of the configuration of the actuator 100 using the magnetic power transmission structure 1 according to this embodiment.

In the present embodiment, the actuator 100 includes a flat plate-shaped base plate 101, and three rectangular fixing members 102 to 104 are arranged side by side in the axial direction on the base plate 101. One end of the shaft member 3 is rotatably fixed to the fixed member 102 via a bearing 105. The shaft member 3 is also rotatably fixed to each fixing member (103, 104) arranged on the other end side. A rotary motor 111 is attached to the other end of the shaft member 3, and a coupling 106 is attached so as to sandwich the rotary motor 111 and the fixed member 104. Thereby, the shaft member 3 is fixed rotatably and non-translatably.

On the other hand, the tubular member 2 is arranged between the pair of fixing members (102, 103). A linear guide 107 extending along the axial direction is provided on the surface of the base plate 101, and the bottom surface of the tubular member 2 is attached to the linear guide 107. As a result, the tubular member 2 is fixed so as not to rotate and to translate. Further, four output shafts 112 extending ahead of the fixing member 102 are attached to the surface of the tubular member 2 on the one end side, and a rod end 113 is attached to the tip of the output shaft 112. There is. The output shaft 112 and the rod end 113 form an output shaft.

The rotary motor 111 is an example of a “rotating device” and rotates the shaft member 3 clockwise or counterclockwise. A commercially available rotary motor may be used as the rotary motor 111. A rotation sensor 117 for measuring the rotation amount of the rotation motor 111 is attached to the rotation shaft of the rotation motor 111 so that the inclination of the shaft member 3 can be specified. The type of rotation sensor 117 may not be particularly limited and may be appropriately selected according to the embodiment. For the rotation sensor 117, for example, a known rotary encoder may be used. The inclination of the shaft member 3 means the rotation angle of the shaft member 3, that is, the angle around the axis of the shaft member 3 with respect to the tubular member 2. In the example of FIG. 10, the rotation sensor 117 is attached to the other end of the shaft member 3. However, the arrangement of the rotation sensor 117 is not limited to such an example, and may be appropriately selected according to the embodiment. The rotation sensor 117 may be attached to the bearing 105 so as to be arranged near one end of the shaft member 3, for example. When the rotation sensor 117 is attached to the rear end of the rotation motor 111, a measurement error may occur due to the reduction gear (not shown) attached to the rotation motor 111. On the other hand, when the rotation sensor 117 is attached to the bearing 105, the rotation of the shaft member 3 can be directly measured. Therefore, the rotation amount of the shaft member 3 by the rotation motor 111 can be accurately measured.

A position sensor 116 is attached to the base plate 101 so that the position of the tubular member 2 with respect to the shaft member 3 can be specified. However, the arrangement of the position sensor 116 is not limited to such an example, and may be appropriately selected according to the embodiment. The position sensor 116 may be attached to the tubular member 2, for example. For this position sensor 116, for example, a known linear encoder may be used. The type of position sensor 116 is not particularly limited, and may be appropriately selected according to the embodiment.

This actuator 100 can operate as follows. That is, by driving the rotation motor 111, the shaft member 3 can be rotated clockwise or counterclockwise. Then, according to the rotation of the shaft member 3, the tubular member 2 can be translated in the axial direction as described above. Therefore, in the actuator 100 according to the present embodiment, by driving the rotary motor 111, the output shaft formed of the output shaft 112 and the rod end 113 can be translated.

[Control device]
(Hardware configuration)
Next, an example of the control device for controlling the operation of the actuator 100 as described above will be described with reference to FIG. FIG. 11 schematically illustrates the hardware configuration of the control device 9 according to the present embodiment.

As illustrated in FIG. 11, the control device 9 according to the present embodiment includes a control unit 91 and a control unit 91 that include a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and the like. The computer is electrically connected to a storage unit 92 that stores a program 921 to be executed and the like, and an external interface 93 for connecting to an external device. However, in FIG. 11, the external interface is described as “external I / F”.

In the magnetic power transmission structure 1 described above, when the position of the tubular member 2 with respect to the shaft member 3 and the inclination of the shaft member 3 are determined, the protrusion 33 of the shaft member 3 and each convex unit 23 of the tubular member 2 are formed. Since the positional relationship with each convex portion 231 is determined, the force in the propulsion direction that acts on the tubular member 2 (hereinafter also referred to as “output”) is determined. Therefore, the control device 9 according to the present embodiment stores, in the storage unit 92, correspondence data 922 indicating the relationship between the position z of the tubular member 2, the inclination θ of the shaft member 3, and the output F acting on the tubular member 2. keeping.

Here, the correspondence data 922 will be described with reference to FIGS. 12A to 12C. FIG. 12A shows the relationship between the position z of the tubular member 2 and the output F when the inclination θ of the shaft member 3 is constant. Further, FIG. 12B shows a relationship between the inclination θ of the shaft member 3 and the output F when the position z of the tubular member 2 is constant. Further, FIG. 12C shows an example of the correspondence data 922.

For example, after the actuator 100 is manufactured, the shaft member 3 is tilted at the inclination θ and the tubular member 2 is arranged at the position za. Then, while keeping the inclination θ of the shaft member 3 constant, the tubular member 2 is moved at predetermined intervals, and the force acting on the tubular member 2 is measured as the output F. As a result, data showing the relationship between the position z of the tubular member 2 and the output F as illustrated in FIG. 12A can be obtained. In the example of FIG. 12A, at the position za, when the shaft member 3 is tilted at the angle θ, each convex portion 231 of the tubular member 2 and the protrusion 33 of the shaft member 3 face each other. The position of the tubular member 2 is shown. Further, L indicates the interval between the ridges adjacent to each other in the axial direction of the protrusion 33.

Similarly, after the actuator 100 is manufactured, the tubular member 2 is placed at the position z and the shaft member 3 is tilted at the inclination θa. Then, while the position z of the tubular member 2 is kept constant, the shaft member 3 is tilted at every predetermined angle, and the force acting on the tubular member 2 is measured as the output F. As a result, data showing the relationship between the inclination θ of the shaft member 3 and the output F as illustrated in FIG. 12B can be obtained. In the example of FIG. 12B, the inclination θa is set such that when the tubular member 2 is at the position z, the convex portions 231 of the tubular member 2 and the protrusions 33 of the shaft member 3 face each other. The inclination of the member 3 is shown.

Then, by obtaining the data as shown in FIGS. 12A and 12B, correspondence data 922 showing the relationship between the position z of the tubular member 2 and the inclination θ of the shaft member 3 and the output F illustrated in FIG. 12C. Can be obtained. It should be noted that such correspondence data 922 may be given as an approximate function, or may be given as tabular data.

Further, the control device 9 according to the present embodiment is connected to the rotation motor 111, the position sensor 116, and the rotation sensor 117 via each external interface 93. Therefore, the control device 9 can acquire the values of the position z of the tubular member 2 and the inclination θ of the shaft member 3 based on the outputs of the position sensor 116 and the rotation sensor 117. Then, the control device 9 refers to the correspondence data 922, identifies the output F of the actuator 100 to be driven based on the values of the position z of the tubular member 2 and the inclination θ of the shaft member 3, and determines the output F as the output F. The rotation motor 111 is driven at the corresponding rotation direction and speed (PWM input). Thereby, the control device 9 can control the operation of the actuator 100. A specific control method will be described in detail in a control example described later.

The specific hardware configuration of the control device 9 may be omitted, replaced, or added as appropriate depending on the embodiment. The control device 9 may be a general-purpose information processing device such as a desktop PC (Personal Computer) or a tablet PC, as well as an information processing device designed specifically for the provided service. Further, the control device 9 may be configured by one or a plurality of information processing devices.

(Software configuration)
Next, an example of the software configuration of the control device 9 according to the present embodiment will be described with reference to FIG. FIG. 13 schematically illustrates an example of the software configuration of the control device 9 according to this embodiment. In the present embodiment, the control unit 91 of the control device 9 loads the program 921 stored in the storage unit 92 into the RAM. Then, the control unit 91 interprets and executes the program 921 loaded in the RAM by the CPU to control each component. Accordingly, the control device 9 operates as a computer including the position control unit 911 and the force control unit 912 as a software module.

The position control unit 911 controls the operation of the actuator 100 so as to move the tubular member 2 to the desired position z _target . On the other hand, the force control unit 912 controls the operation of the actuator 100 so that the desired output F _target is obtained from the tubular member 2. In this embodiment, an example in which all of these software modules are realized by a general-purpose CPU has been described. However, some or all of these software modules may be implemented by one or more dedicated processors. Further, regarding the software configuration of the control device 9, depending on the embodiment, omission, replacement, and addition of software modules may be appropriately performed. Each software module will be described in detail in an operation example described later.

(Example of control)
Next, an example of operation control of the actuator 100 by the control device 9 according to the present embodiment will be described. The control device 9 controls the operation of the actuator 100 by the following three methods.

(1) Position Control First, an example of position control of the tubular member 2 (output shaft) by the control device 9 will be described with reference to FIG. FIG. 14 illustrates an example of a method of controlling the position of the tubular member 2 by the control device 9. In the example of FIG. 14, the control device 9 controls the operation of the actuator 100 only by the information of the position z of the tubular member 2 obtained by the position sensor 116.

Specifically, the control unit 91 of the control device 9 operates as the position control unit 911 and acquires the value of the position z of the tubular member 2 based on the output of the position sensor 116. Further, the control unit 91 receives the value of the desired position z _target of the tubular member 2. The value of the desired position z _target may be acquired as appropriate. For example, the value of the desired position z _target may be obtained by an input from another computer, or a desired operation algorithm (for example, when the external force acts on the output shaft, the position of the tubular member 2 is kept constant). It may be obtained by calculating according to

Subsequently, the control unit 91, based on the difference between the value of the desired position z _{target and} the value of the position z acquired from the position sensor 116, a rotation motor for moving the tubular member 2 to the desired position z _target. The rotation direction of 111 is specified. Then, the control unit 91 gives the rotation motor 111 a command to drive the specified rotation direction at a predetermined speed.

The predetermined speed for driving the rotary motor 111 may be arbitrary. For example, the control unit 91 may give a command to the rotary motor 111 to drive at a speed according to the magnitude of the difference between the value of the desired position z _{target and} the value of the position z acquired from the position sensor 116. Further, for example, the control unit 91 gives the rotation motor 111 a command to drive at a constant speed regardless of the magnitude of the difference between the desired position z _target value and the position z value acquired from the position sensor 116. May be.

Accordingly, the actuator 100 is controlled so that the tubular member 2 moves to the desired position z _target . When performing this control, the control device 9 does not use the output of the rotation sensor 117. Therefore, when adopting this control method, the rotation sensor 117 may be omitted.

(2) Force Control Next, an example of force control of the actuator 100 by the control device 9 will be described with reference to FIG. FIG. 15 illustrates an example of a method of controlling the force of the actuator 100 by the control device 9. In the example of FIG. 15, the control device 9 acquires the information of the position z of the tubular member 2 from the position sensor 116, and acquires the information of the inclination θ of the shaft member 3 from the rotation sensor 117. Then, the control device 9 controls the operation of the actuator 100 based on these pieces of information (output) so that the force F generated on the tubular member 2 (output shaft) of the actuator 100 has a desired value.

Specifically, the control unit 91 of the control device 9 operates as the force control unit 912 and acquires the value of the position z of the tubular member 2 based on the output of the position sensor 116. Further, the control unit 91 acquires the value of the inclination θ of the shaft member 3 based on the output of the rotation sensor 117. Further, the control unit 91 receives the value of the desired force F _target generated by the tubular member 2 (output shaft). The value of the desired force F _target may be acquired as appropriate. For example, the value of the desired force F _target may be obtained by input from another computer, or a desired operation algorithm (for example, the tubular member 2 may be operated like a spring, that is, an external force may be applied to the output shaft). When the tubular member 2 is displaced due to the action of, the force corresponding to the amount of displacement is generated in the tubular member 2 in the direction of the original position.).

Subsequently, the control unit 91 refers to the correspondence data 922, and according to the value of the position z of the tubular member 2 and the value of the inclination θ of the shaft member 3 acquired from the position sensor 116, the tubular member 2 is obtained. The value of the force F generated on the (output shaft) is specified. Further, the control unit 91 causes the tubular member 2 (output shaft) to obtain the desired force based on the difference between the value of the force F generated on the tubular member 2 (output shaft) and the value of the desired force F _target . The rotation direction and speed of the rotary motor 111 are determined so as to generate the force F _target . Then, the control unit 91 gives the rotation motor 111 a command to drive in the determined rotation direction and speed. As a result, the actuator 100 is controlled so that the desired force F _target is obtained via the output shaft.

(3) Position and Force Control Next, an example of the position and force control of the tubular member 2 (output shaft) by the control device 9 will be described with reference to FIG. FIG. 16 illustrates an example of a method of controlling the position and force of the tubular member 2 by the control device 9. In the example of FIG. 16, the control device 9 acquires information on the position z of the tubular member 2 from the position sensor 116, and acquires information on the inclination θ of the shaft member 3 from the rotation sensor 117. Then, the control device 9 of the actuator 100 moves the tubular member 2 (output shaft) to the desired position z _target in a state where the desired force F _target is obtained, based on these pieces of information (output). Control movements.

Specifically, the control unit 91 of the control device 9 acquires the value of the position z of the tubular member 2 based on the output of the position sensor 116. Further, the control unit 91 acquires the value of the inclination θ of the shaft member 3 based on the output of the rotation sensor 117.

Next, the control unit 91 operates as the position control unit 911 and receives the value of the desired position z _target of the tubular member 2. The value of the desired position z _target may be appropriately acquired as described above. Then, the control unit 91, based on the difference between the value of the desired position z _{target and} the value of the position z acquired from the position sensor 116, the value of the desired force F _target generated in the tubular member 2 (output shaft). To decide.

The method of determining the value of the desired force F _target may be appropriately selected according to the embodiment. For example, the control unit 91 may determine the value of the desired force F _target so that the tubular member 2 (output shaft) operates like a spring. In other words, when an external force acts on the output shaft and the tubular member 2 is displaced, the control section 91 applies a force in the direction of the original position (desired position z _target ) according to the difference in the values of the position. The value of the desired force F _target may be determined to be generated. Further, for example, the control unit 91 may fix the value of the desired force F _target to a constant value.

Subsequently, the control unit 91 operates as the force control unit 912, and by referring to the correspondence data 922, the value of the position z of the tubular member 2 and the value of the inclination θ of the shaft member 3 acquired from the position sensor 116. According to, the value of the force F generated in the tubular member 2 (output shaft) is specified. Further, the control unit 91 causes the tubular member 2 (output shaft) to obtain the desired force based on the difference between the value of the force F generated on the tubular member 2 (output shaft) and the value of the desired force F _target . The rotation direction and speed of the rotary motor 111 are determined so as to generate the force F _target . Then, the control unit 91 gives the rotation motor 111 a command to drive in the determined rotation direction and speed. As a result, the actuator 100 is controlled to move the tubular member 2 (output shaft) to the desired position z _target in a state where the desired force F _target is obtained. For convenience of description, the rotation sensor 117 is attached to the shaft member 3 in FIGS. 15 and 16. However, the position of the rotation sensor 117 is not limited to such an example, and may be attached to the rear end of the rotation motor 111 as in FIG. 10 or may be attached to the bearing 105.

§4 Features As described above, in the magnetic power transmission structure 1 according to the present embodiment, the magnets 25 for forming the magnetic circuit are not arranged on the outer side in the radial direction of the convex units 23, and the convex units 23 are not arranged. It is arranged so as to be adjacent to 23 around the axis. Therefore, the influence of the dimensional error of each magnet 25 can be prevented from affecting the dimensional accuracy of the distance between each convex portion 231 of each convex unit 23 and the protrusion 33 of the shaft member 3. That is, it is possible to manage the dimensional error of the distance between each convex portion 231 of each convex unit 23 and the ridge 33 of the shaft member 3 without considering the influence of the dimensional error of each magnet 25. In addition, in the present embodiment, either the convex unit 23 or the magnet 25 may be arranged on the radially outer side when viewed from the shaft member 3, instead of arranging both the convex unit 23 and the magnet 25. It is possible to reduce the number of parts. In the present embodiment, each convex unit 23 is formed integrally with the inner peripheral surface 22 of the tubular member 2, so that the number of parts can be further suppressed. Specifically, the magnetic power transmission structure 1 can be configured with four parts, namely the tubular member 2 having the two convex units 23 formed on the inner peripheral surface 22, the two magnets 25, and the shaft member 3. it can. Therefore, according to the present embodiment, it is possible to provide a magnetic screw mechanism having a simpler structure and easy to control the dimensional accuracy. As a result, it is possible to mass-produce a magnetic screw mechanism that is cheaper and more practical, while suppressing variations in performance.

In the present embodiment, each magnet 25 may be a magnet widely used in rotary motors and the like. Therefore, each magnet 25 can be obtained at low cost. Further, in each convex unit 23, each convex portion 231 is magnetized by each magnet 25 and functions as a magnetic pole. The step of providing the magnetic poles is merely the step of providing the convex portions 231 on the inner peripheral surface of the convex unit 23. Therefore, the magnetic poles formed on the tubular member 2 side, that is, the number of the convex portions 231 can be easily adjusted. Thereby, the magnitude of the output can be appropriately adjusted by the magnetic screw mechanism. Therefore, according to the present embodiment, it is possible to provide a magnetic screw mechanism having excellent productivity and high practicality.

§5 Modifications Although the embodiments of the present invention have been described in detail above, the above description is merely an example of the present invention in all respects. It goes without saying that various improvements and modifications can be made without departing from the scope of the present invention. Moreover, regarding each component of the magnetic power transmission structure 1, the component may be appropriately omitted, replaced, or added depending on the embodiment. The shape and size of each component of the magnetic power transmission structure 1 may be appropriately set according to the embodiment. For example, the following changes are possible. The following modifications can be combined as appropriate. Further, in the following, the same reference numerals are used for the same constituent elements as those in the above-described embodiment, and the description of the same points as those in the above-described embodiment is appropriately omitted.

<5.1>
In the above embodiment, the tubular member 2 is provided with two convex units 23, two groove portions 24, and two magnets 25. However, the numbers of the convex units 23, the groove portions 24, and the magnets 25 provided on the tubular member 2 are not limited to two, and may be three or more. Further, the numbers of the convex units 23, the groove portions 24, and the magnets 25 provided on the tubular member 2 are not limited to a plurality, and may be one. Further, if the above magnetic circuit can be formed, the numbers of the convex units 23 and the magnets 25 do not have to match each other. For example, a plurality of magnets 25 may be arranged in one groove 24.

In addition, in the above implementation, a plurality of convex portions 231 are provided on the inner surface of each convex unit 23. In the example shown in FIG. 9A, each convex unit 23 is provided with five convex portions 231. However, the number of the convex portions 231 provided in each convex unit 23 is not limited to such an example, and may be 6 or more, or 4 or less. Moreover, the number of the convex portions 231 provided in each convex unit 23 may not be plural, and may be one.

<5.2>
The shape and size of each component of the magnetic power transmission structure 1 according to the above-described embodiment may be appropriately changed according to the embodiment.

For example, in the above embodiment, the main body 30 of the shaft member 3 is solid. However, the shape of the main body portion 30 may not be limited to such an example. The magnetic flux of each magnet 25 hardly reaches the central portion of the shaft member 3. Therefore, the central portion of the shaft member 3 is a portion that hardly affects the magnetic action. Therefore, the main body portion 30 may be formed into a hollow shape, for example, in a cylindrical shape. As a result, the weight of the shaft member 3 can be reduced with almost no effect on the magnetic action. From the viewpoint of strength, when the main body 30 of the shaft member 3 is formed hollow, a non-magnetic material such as a resin material may be filled in the hollow.

Further, in the above embodiment, the number of the protrusions 33 of the shaft member 3 is one. However, the number of protrusions 33 is not limited to one and may be appropriately selected according to the embodiment. For example, the shaft member 3 may be formed with two or more ridges 33.

Further, in the above embodiment, the protrusions 33 are continuous from one end to the other end in the axial direction. However, the ridge 33 does not have to be limited to such a shape and may be partially interrupted. Further, in the above embodiment, the protrusion 33 is formed in the right spiral. However, the form of the ridge 33 may not be limited to such an example. The ridge 33 may be formed in a left spiral.

Further, in the above-described embodiment, each convex unit 23 is integrally formed on the inner peripheral surface 22. However, the form of each convex unit 23 may not be limited to such an example. Each convex unit 23 may be formed separately from the inner peripheral surface 22 of the main body 20. In this case, each convex unit 23 may be appropriately attached to the inner peripheral surface 22 of the main body portion 20. For example, the tubular member 2 may include a fixture for fixing each convex unit 23 in a predetermined position.

Also, in the above-described embodiment, the cross-sectional shape of each convex portion 231 of each convex unit 23 along the axial direction is rectangular. However, the sectional shape of each convex portion 231 is not limited to the rectangular shape, and may be appropriately selected according to the embodiment. The cross-sectional shape along the axial direction of each convex portion 231 may be, for example, a triangular shape, a trapezoidal shape, or the like. From the viewpoint of ease of processing, the cross-sectional shape of each convex portion 231 along the axial direction is preferably rectangular as in the above embodiment.

Further, in the above-described embodiment, each convex portion 231 of each convex unit 23 is formed in an arc shape when viewed along the axial direction. However, the shape of each convex portion 231 viewed from the axial direction is not limited to such an example, and may be appropriately selected according to the embodiment. The shape of each convex portion 231 viewed from the axial direction may be, for example, a trapezoidal shape.

Further, in the above-described embodiment, the interval between the convex portions 231 in the axial direction matches the interval between the protrusions 33 in the axial direction. However, the arrangement of the convex portions 231 in the convex unit 23 need not be limited to this example, and may be appropriately determined according to the embodiment. The distance between the protrusions 231 in the axial direction may not match the distance between the protrusions 33 in the axial direction.

Further, in the above embodiment, each magnet 25 is formed in an arc shape having a cross section of approximately 90 degrees. However, the shape of each magnet 25 may not be limited to such an example. The shape of each magnet 25 may be appropriately determined according to the embodiment as long as the magnetic circuit as described above can be configured.

Further, in the above embodiment, the outer shape of the tubular member 2 is circular. However, the outer shape of the tubular member 2 is not limited to such an example, and may be appropriately selected according to the embodiment. The inner peripheral surface 22 side and the outer peripheral surface side of the tubular member 2 may have different shapes. Further, a housing or the like may be appropriately provided outside the tubular member 2.

<5.3>
In the above embodiment, the magnetic material is used as an example of the material of each of the tubular member 2 and the shaft member 3. However, the material of each of the tubular member 2 and the shaft member 3 is not limited to the magnetic material. For example, a non-magnetic material may be used in the portions of the tubular member 2 and the shaft member 3 that have little influence on the configurations of the magnetic circuits.

The non-magnetic material may be, for example, a resin material or a non-magnetic metallic material. Examples of the resin material include ABS (acrylonitrile butadiene styrene copolymer), PLA (polylactic acid), nylon, polyacetal, PEEK (polyetheretherketone), and PPS (polyphenylene sulfide). Examples of the non-magnetic metallic material include copper, stainless steel, and aluminum.

<5.4>
In the above embodiment, the inner curved surface 251 of each magnet 25 is magnetized to the first magnetic pole, and the outer curved surface 252 is magnetized to the second magnetic pole opposite to the first magnetic pole. The method of performing the magnetization need not be particularly limited. The magnetization of each magnet 25 may be appropriately performed depending on the embodiment.

17A and 17B exemplify the magnetization direction of each magnet 25. FIG. 17A shows an example in which each magnet 25 is manufactured by radial magnetization. 17B shows an example in which each magnet 25 is manufactured by parallel magnetization. The method of magnetizing the magnets 25 may be either radial magnetization or parallel magnetization.

However, it is relatively difficult to accurately manufacture a magnet having an arcuate cross section in which the magnetic flux is directed in the normal direction by radial magnetization as shown in FIG. 17A. Therefore, from the viewpoint of suppressing the manufacturing cost, it is preferable to manufacture each magnet 25 by parallel magnetization as shown in FIG. 17B. In this case, each magnet 25 may be configured by connecting a plurality of parallel magnetized magnets around an axis. As a result, a magnet having an arc-shaped cross section in which the magnetic flux is directed in the normal direction can be manufactured at a pseudo low cost.

<5.5>
In the actuator 100 according to the above-described embodiment, the rotary motor 111 (rotary motor) is used as a rotating device for rotating the shaft member 3. However, the type of rotating device is not limited to such an example, and may be appropriately selected according to the embodiment.

Further, in the above embodiment, the rotary motor 111 is attached to the shaft member 3. The shaft member 3 is rotatably and non-translatably fixed, whereas the tubular member 2 is non-rotatably and translatably fixed. However, the fixing form of the tubular member 2 and the shaft member 3 may not be limited to such an example. One of the tubular member 2 and the shaft member 3 may be fixed rotatably and non-translatably, and the other may be fixed non-rotatably and translatable. Thereby, by rotating either one of the tubular member 2 and the shaft member 3, the output in the translational direction can be obtained from the other.

For example, by attaching the rotary motor 111 to the tubular member 2, the actuator 100 may be configured so that the tubular member 2 rotates. Further, like the rotary motor, the tubular member 2 is housed in the housing, and the spacer and the coil are arranged between the housing and the tubular member 2 so that the tubular member 2 rotates in the housing. It may be configured.

Further, for example, the actuator 100 may be configured such that one of the tubular member 2 and the shaft member 3 is translated in the axial direction and the rotational movement is taken out from the other. The translation of one of the tubular member 2 and the shaft member 3 may be performed manually, or by a linear motor or a fluid pressure cylinder, for example. In addition, as an example of a configuration in which the rotational movement is taken out, the shaft member 3 is floated so that the shaft member 3 is translated by the force of the wave, whereby the tubular member 2 is rotated to generate power. You may do it. Further, the magnetic power transmission structure 1 may be used as an active suspension of an automobile or the like.

<5.6>
In the above embodiment, the inner curved surface 251 of each magnet 25 is magnetized to the first magnetic pole, and the outer curved surface 252 is magnetized to the second magnetic pole. However, the magnetizing direction of each magnet 25 is not limited to such an example, and the first side surface 255 is magnetized to the first magnetic pole and the second side surface 256 is magnetized to the second magnetic pole. May be.

FIG. 18 schematically illustrates a state in which the magnetic power transmission structure 1A according to the present modification is viewed along the axial direction. In this modification, the first side surface 255 of each magnet 25A is magnetized to the first magnetic pole, and the second side surface 256 is magnetized to the second magnetic pole. That is, when the first side surface 255 is magnetized to the N pole, the second side surface 256 is magnetized to the S pole, and when the first side surface 255 is magnetized to the S pole, the second side surface 256. Is magnetized to the N pole. In both cases, the operating principle of the magnetic power transmission structure 1A is the same. Therefore, hereinafter, for convenience of description, it is assumed that the first side surface 255 is magnetized to the N pole and the second side surface 256 is magnetized to the S pole, and the description of the other case is appropriately omitted. In this modification, the first side surface 255 is an example of the “first surface” in the present invention, and the second side surface 256 is an example of the “second surface” in the present invention. The positional relationship between the first side surface 255 and the second side surface 256 may be interchanged.

Further, in this modification, the main body portion 20A of the tubular member 2A is made of a non-magnetic material. As the material of the main body portion 20A, as the non-magnetic material, for example, a resin material, a non-magnetic metallic material, or the like may be used. As described above, examples of the resin material include ABS, PLA, nylon, polyacetal, PEEK, PPS and the like. Examples of the non-magnetic metallic material include copper, stainless steel, and aluminum. Each convex unit 23 made of a magnetic material is appropriately attached to the inner peripheral surface of the main body 20A.

Except for these points, each magnet 25A is similar to each magnet 25 according to the above-described embodiment, and main body 20A is similar to the main body 20 according to the above-described embodiment. Further, the tubular member 2A according to the present modified example is configured similarly to the tubular member 2 according to the above-described embodiment, and the magnetic power transmission structure 1A in the present modified example is the magnetic power transmission according to the above-described embodiment. It has the same structure as the structure 1.

That is, the magnetic power transmission structure 1A according to the present modification is a tubular member 2A having a shaft member 3 extending along the axial direction and a hollow portion 21 penetrating in the axial direction, and the hollow portion 21 has a shaft. And a tubular member 2A into which the member 3 is inserted. The outer peripheral surface 32 of the shaft member 3 is provided with a ridge 33 spirally formed around the axis. On the other hand, the inner peripheral surface 22 of the cylindrical member 2A is provided with a plurality of convex units 23, a plurality of groove portions 24, and a plurality of magnets 25A. Each convex unit 23 includes a convex portion 231 that protrudes inward in the radial direction, and is arranged so as to be spaced around the axis. Each groove 24 is arranged between a pair of convex units 23 adjacent to each other around the axis. Each magnet 25A is arranged in each groove 24, faces the first side surface 255 facing one of the pair of convex units 23, and the first side surface 255, and faces the other of the pair of convex units 23. The second side surface 256 is included.

In the example of FIG. 18, two convex units 23, two groove portions 24, and two magnets 25A are provided. However, the numbers of the convex units 23, the groove portions 24, and the magnets 25A are not limited to two, and may be three or more. Further, the number of the convex portions 231 provided in each convex unit 23 may be plural or may be one. When each convex unit 23 is provided with a plurality of convex portions 231, the convex portions 231 are arranged so as to be separated from each other in the axial direction.

In the magnetic power transmission structure 1A according to this modification, the following magnetic circuit is formed in the state where the convex portion 231 of each convex unit 23 of the tubular member 2A faces the protrusion 33 of the shaft member 3. It is formed. That is, as shown in FIG. 18, the magnetic flux emitted from the first side surface 255 of each magnet 25A magnetized to the N pole enters one of the pair of convex units 23 and enters the convex portion 231. To reach. The magnetic flux that has reached the convex portion 231 of the one convex unit 23 is emitted from the one convex unit 23 and enters the protrusion 33 of the shaft member 3. The magnetic flux that has entered the ridge 33 reaches the portion facing the other convex unit 23 through the inside of the ridge 33 and / or via the shaft, and from this portion to the convex portion 231 of the other convex unit 23. It is released toward. The magnetic flux that has entered the convex portion 231 of the other convex unit 23 reaches the second side surface 256 of each magnet 25A magnetized to the S pole via the other convex unit 23.

As a result, in the present modification, the magnetic flux emitted from each magnet 25A passes through the convex unit 23 on one side, the shaft member 3 and the convex unit 23 on the other side in this order, and returns to each magnet 25A again. To be done. Even when the first side surface 255 of each magnet 25A is magnetized to the S pole and the second side surface 256 is magnetized to the N pole, the magnetic circuit is the same as the above although the direction of the magnetic flux is opposite. It is formed. This magnetic circuit operates in the same manner as the above embodiment. Therefore, according to this modification, the cylindrical member 2A and the shaft member 3 constitute a magnetic screw mechanism that operates in the same manner as in the above embodiment.

In this modification, magnetic flux passes between each side surface (255, 256) of each magnet 25A and each convex unit 23. Therefore, when a gap is formed between each side surface (255, 256) and each convex unit 23, the magnetic resistance of the gap weakens the magnetic force of the magnetic circuit formed. Therefore, the gap is made relatively small, or the grooves 24 and the magnets 25A have the same shape so that no gap is formed between each side surface (255, 256) and each convex unit 23. Preferably.

<5.7>
In the above embodiment, no other member is arranged between the tubular member 2 and the shaft member 3. Therefore, the convex portions 231 of the convex units 23 may come into contact with the protrusions 33 of the shaft member 3, and either or both may be damaged. In order to prevent this, a member for suppressing this contact may be arranged between the tubular member 2 and the shaft member 3.

FIG. 19 is a partial cross-sectional view schematically illustrating the magnetic power transmission structure 1B according to this modification. The magnetic power transmission structure 1B according to the present modification is different from the magnetic power transmission structure according to the above-described embodiment except that the cylindrical protection member 7 is arranged between the tubular member 2 and the shaft member 3. It has the same structure as the structure 1. The shape of the protective member 7 is not particularly limited as long as it can be arranged between the convex portion 231 of the tubular member 2 and the protrusion 33 of the shaft member 3, and is appropriately selected according to the embodiment. May be done. Further, as the material of the protective member 7, for example, aluminum, aluminum alloy, magnesium alloy, engineering plastic, or the like may be used.

FIG. 20 is a partial cross-sectional view schematically illustrating a magnetic power transmission structure 1C according to another modification. In the magnetic power transmission structure 1C according to the present modification, the non-magnetic material 81 is filled in the recesses 232 provided between the adjacent projections 231 in the axial direction of each projection unit 23. When a gap is provided between each convex unit 23 and each magnet 25, the non-magnetic material 81 may be filled also in this gap. Further, the non-magnetic material 82 is filled in the recesses 35 provided between the protrusions 33 in the axial direction of the outer peripheral surface 32 of the shaft member 3. Except for these points, the magnetic power transmission structure 1C has the same configuration as the magnetic power transmission structure 1 according to the above-described embodiment.

Each non-magnetic material (81, 82) may be any material that does not adversely affect the magnetic circuit formed between the tubular member 2 and the shaft member 3, and is, for example, a resin material or a non-magnetic metallic material. May be Examples of the resin material include ABS, PLA, nylon, polyacetal, PEEK, PPS and the like. Examples of the non-magnetic metallic material include copper, stainless steel, and aluminum.

The method of filling each recess (232, 35) with each non-magnetic material (81, 82) may be appropriately selected according to the embodiment. For example, each non-magnetic material (81, 82) softened by heating is poured into each recess (232, 35), and each non-magnetic material (81, 82) poured is cooled and solidified to form each recess ( 232, 35) may be filled with each non-magnetic material (81, 82). Further, by forming each non-magnetic material (81, 82) having the same shape as each recess (232, 35) and fitting each formed non-magnetic material (81, 82) into each recess (232, 35). The recesses (232, 35) may be filled with the non-magnetic material (81, 82).

At this time, it is preferable to fill each non-magnetic material (81, 82) so that the inner peripheral surface 22 of the tubular member 2 and the outer peripheral surface 32 of the shaft member 3 are flush with each other. That is, each of the recesses (232, 35) is arranged such that the surface of the non-magnetic material 81 is flush with the surface of each convex portion 231 and the surface of the non-magnetic material 82 is flush with the surface of the protrusion 33. It is preferably filled with a non-magnetic material (81, 82). When a gap is provided between each convex unit 23 and each magnet 25, the nonmagnetic material 81 is also filled in this gap so that the inner peripheral surface 22 of the tubular member 2 is flush. preferable. Thereby, in the tubular member 2 and the shaft member 3, it is possible to sufficiently suppress the unevenness due to the respective convex portions 231 and the protrusions 33. Therefore, it is possible to prevent at least one of the protrusions 231 and the protrusions 33 from being damaged due to the contact between the protrusions 231 and the protrusions 33.

Further, each non-magnetic material (81, 82) may be filled so that each convex portion 231 and the protrusion 33 are embedded. Accordingly, in the tubular member 2 and the shaft member 3, the projections and depressions 231 and the projections 33 can be eliminated, so that at least one of the projections 231 and the projections 33 can be reliably prevented from being damaged. it can.

Note that the form using the non-magnetic material is not limited to such an example, and may be appropriately changed according to the embodiment. For example, either one of the non-magnetic materials (81, 82) may be omitted. When a gap exists between the magnet 25 and the convex unit 23 adjacent to each other in the circumferential direction (around the axis), the nonmagnetic material 81 may be filled in the gap. Further, the inner peripheral surface 22 of the tubular member 2 may be filled with the non-magnetic material 81 so that the surface of each magnet 25 and the surface of each convex portion 231 are flush with each other.

FIG. 21 is a partial cross-sectional view schematically illustrating the configuration of a magnetic power transmission structure 1D according to another modification. The magnetic power transmission structure 1D according to this modification has the same configuration as the magnetic power transmission structure 1 according to the above-described embodiment, except that the magnetic power transmission structure 1D further includes a first covering member 85 and a second covering member 86. is doing.

The first covering member 85 and the second covering member 86 are each formed in a cylindrical shape. The outer diameter of the first covering member 85 is substantially the same as the inner diameter of the portion of the tubular member 2 including the convex portions 231. As a result, the first covering member 85 is arranged radially inward of the inner peripheral surface 22 of the tubular member 2, and covers the shaft member 3 with each convex unit 23. On the other hand, the inner diameter of the second covering member 86 is almost the same as the outer diameter of the portion of the shaft member 3 including the protrusions 33, and the outer diameter of the second covering member 86 is slightly larger than the inner diameter of the first covering member 85. It is getting smaller. As a result, the second covering member 86 is arranged radially outside the outer peripheral surface 32 of the shaft member 3 and covers the tubular member 2 with the ridge 33.

The material of each covering member (85, 86) may be a material which does not adversely affect the magnetic circuit formed between the tubular member 2 and the shaft member 3, like the non-magnetic material (81, 82). For example, a resin material or a non-magnetic metallic material may be used. The same resin material or metal material as the non-magnetic material (81, 82) may be used for each covering member (85, 86). The size and shape of each covering member (85, 86) may be appropriately determined according to the embodiment, and may be formed in a sheet shape, for example.

The form in which the covering member is used is not limited to such an example, and may be appropriately changed according to the embodiment. For example, one of the covering members (85, 86) may be omitted. The non-magnetic material may be applied to the omitted one of the covering members (85, 86). The form using this covering member may be applied together with the form using the above-mentioned non-magnetic material.

According to the modified examples illustrated in FIGS. 20 and 21, it is possible to reduce the possibility that the protrusions 231 and the protrusions 33 will be damaged. Furthermore, according to each modification, the following operational effects can be obtained. That is, each non-magnetic material (81, 82) and each covering member (85, 86) can act as a reinforcing member for the tubular member 2 and the shaft member 3, respectively. This can alleviate the stress concentration in the recesses (232, 35), so that the strength of the tubular member 2 and the shaft member 3 against the force of bending the shaft can be increased.

Further, in the tubular member 2 and the shaft member 3, by reducing the unevenness due to the respective convex portions 231 and the protrusions 33, the inner peripheral surface 22 of the tubular member 2 and the outer peripheral surface 32 of the shaft member 3 can be easily cleaned. Become. Therefore, each of the magnetic power transmission structures (1C, 1D) can be used in a scene requiring cleaning such as transportation of food or medicine.

Further, in the tubular member 2 and the shaft member 3, the unevenness due to the respective projections 231 and the protrusions 33 is reduced to perform steam sterilization on the inner peripheral surface 22 of the tubular member 2 and the outer peripheral surface 32 of the shaft member 3. Will be able to. Thereby, the sterility of the tubular member 2 and the shaft member 3 can be improved.

By using a material such as stainless steel for each non-magnetic material (81, 82) and each covering member (85, 86), it is possible to suppress the generation of rust due to the cleaning and steam sterilization. In the magnetic power transmission structure 1C, when the protrusions 231 and the protrusions 33 are exposed from the nonmagnetic materials (81, 82), the exposed portions may be plated. As a result, it is possible to suppress the generation of rust on each convex portion 231 and the protrusion 33.

<5.8>
In the above embodiment, the convex unit 23 having the convex portions 231 can be manufactured by cutting the magnetic material curved in an arc shape so as to form the concave portions 232. At this time, the shape of each recess 232 may not be particularly limited and may be appropriately selected according to the embodiment.

22A and 22B schematically illustrate an example of the shape of each recess 232. The convex unit 23E illustrated in FIG. 22A and the convex unit 23F illustrated in FIG. 22B have the same configuration as the convex unit 23 according to the above-described embodiment, except that the shapes of the respective concave portions 232 are different. ing.

In the example of FIG. 22A, each concave portion 232 of the convex unit 23E is formed so that the bottom surface becomes flat. Each concave portion 232 of the convex unit 23E can be easily formed by wire electric discharge machining. On the other hand, in the example of FIG. 22B, each concave portion 232 of the convex unit 23F is formed so that the bottom surface is curved according to the curve of the convex unit 23F. Each concave portion 232 of the convex unit 23F can be formed by, for example, a circular cutting machine adapted to the maximum cutting diameter. From the viewpoint of manufacturing cost, the shape of each recess 232 is preferably flat as illustrated in FIG. 22A.

<5.9>
In the above embodiment, the inner curved surface 251 of each magnet 25 is formed smoothly. However, the shape of the inner curved surface 251 of each magnet 25 is not limited to such an example, and may be appropriately selected according to the embodiment. The inner curved surface 251 of each magnet 25 may be provided with a convex portion that protrudes inward in the radial direction, similarly to each convex unit 23.

FIG. 23 schematically illustrates a magnet 25G according to this modification. The magnet 25G has the same configuration as each magnet 25 according to the above-described embodiment, except that the inner curved surface 251 includes a convex portion 258 that projects inward in the radial direction. The magnet 25G can be used as a substitute for each of the magnets 25.

In this modification, the inner curved surface 251 is provided with a plurality of convex portions 258. Accordingly, the inner curved surface 251 is further provided with a concave portion 259 arranged between the adjacent convex portions 258 in the axial direction. Similar to the modification, the recess 259 may be filled with a non-magnetic material. The number of protrusions 258 is not particularly limited and may be appropriately selected according to the embodiment. Moreover, the number of the convex portions 258 may not be plural, and may be one.

The convex portions 258 are arranged apart from each other in the axial direction. The protrusions 258 may be arranged so as to correspond to the axial arrangement of the protrusions 33 of the shaft member 3. That is, the interval between the protrusions 258 in the axial direction may match the interval between the protrusions 33 in the axial direction. However, the interval of the protrusions 258 in the axial direction need not be limited to such an example, and may not be the same as the interval of the protrusions 33 in the axial direction.

The shapes and dimensions of the convex portions 258 and the concave portions 259 may be set similarly to the convex portions 231 and the concave portions 232 of the convex unit 23. Each convex portion 258 may be formed in a spiral shape around the axis so as to correspond to the protrusion 33 of the shaft member 3, or may be formed to extend along the axis. According to this modification, by providing the convex portion 258 on the inner curved surface 251 of the magnet 25G, it is easy to form a magnetic circuit between the magnet 25G and the protrusion 33 of the shaft member 3, and a magnetic screw having a higher output can be obtained. The mechanism can be configured.

1 ... Magnetic power transmission structure,
2 ... Cylindrical member, 20 ... Main body,
21 ... Hollow part, 22 ... Inner peripheral surface,
23 ... convex unit, 231, ... convex portion, 232 ... concave portion,
24 ... groove,
25 ... Magnet, 251 ... Inner curved surface, 252 ... Outer curved surface,
255 ... 1st side surface, 256 ... 2nd side surface,
3 ... Shaft member,
31 ... Shaft, 32 ... Outer peripheral surface,
33 ... ridge, 35 ... recess,
100 ... actuator,
101 ... base plate,
102, 103, 104 ... fixing member,
105 ... Bearing, 106 ... Coupling,
107 ... Linear guide,
111 ... rotary motor,
112 ... Output shaft, 113 ... Rod end,
116 ... Position sensor, 117 ... Rotation sensor,
9 ... Control device,
91 ... Control unit, 911 ... Position control unit, 912 ... Force control unit,
92 ... storage unit, 921 ... program, 922 ... correspondence data,
93 ... External interface

Claims

A shaft member having an axis and an outer peripheral surface and extending along the axial direction;
A tubular member having a hollow portion and an inner peripheral surface penetrating in the axial direction, wherein the shaft member is inserted into the hollow portion, and a tubular member,
Equipped with
The outer peripheral surface of the shaft member is provided with a ridge that protrudes outward in the radial direction of the shaft, the ridge being formed in a spiral shape around the shaft,
On the inner peripheral surface of the tubular member, a convex unit including a convex portion that protrudes inward in the radial direction, a convex unit that is arranged adjacent to the convex unit around the axis, and faces the protrusion. A magnet including a surface and a second surface facing the first surface,
The first surface of the magnet is magnetized to a first magnetic pole,
The second surface of the magnet is magnetized to a second magnetic pole opposite to the first magnetic pole,
Magnetic power transmission structure.
A plurality of the convex portions of the convex unit are provided,
The plurality of convex portions of the convex unit are arranged apart from each other in the axial direction,
The magnetic power transmission structure according to claim 1.
The convex unit has a concave portion provided between the convex portions adjacent to each other in the axial direction,
The concave portion of the convex unit is filled with a non-magnetic material,
The magnetic power transmission structure according to claim 2.
The convex unit is integrally formed on the inner peripheral surface of the tubular member,
The magnetic power transmission structure according to any one of claims 1 to 3.
The first surface of the magnet includes a convex portion protruding inward in the radial direction.
The magnetic power transmission structure according to any one of claims 1 to 4.
A plurality of the convex portions of the magnet are provided,
The plurality of convex portions of the magnet are arranged apart from each other in the axial direction,
The magnetic power transmission structure according to claim 5.
The convex unit is provided in plural,
A plurality of the magnets are provided,
The respective convex units are arranged with a space around the axis,
The inner peripheral surface of the tubular member is further provided with a plurality of groove portions respectively arranged between the pair of convex units adjacent to each other around the axis,
The magnets are arranged in the groove portions,
The magnetic power transmission structure according to any one of claims 1 to 6.
The outer peripheral surface of the shaft member is provided with a concave portion arranged between the protrusions in the axial direction,
The recess of the shaft member is filled with a non-magnetic material,
The magnetic power transmission structure according to any one of claims 1 to 7.
Further comprising a first covering member which is arranged radially inward of the inner peripheral surface of the tubular member and which covers the convex unit of the tubular member,
The magnetic power transmission structure according to any one of claims 1 to 8.
Further comprising a second covering member that is arranged radially outside the outer peripheral surface of the shaft member and that covers the protrusion of the shaft member.
The magnetic power transmission structure according to any one of claims 1 to 9.
A shaft member having an axis and an outer peripheral surface and extending along the axial direction;
A tubular member having a hollow portion and an inner peripheral surface penetrating in the axial direction, wherein the shaft member is inserted into the hollow portion, and a tubular member,
Equipped with
The outer peripheral surface of the shaft member is provided with a ridge that protrudes outward in the radial direction of the shaft, the ridge being formed in a spiral shape around the shaft,
The inner peripheral surface of the tubular member includes a plurality of convex units that respectively include convex portions that project inward in the radial direction and are spaced apart from each other around the axis, and a pair of the convex units that are adjacent to each other around the axis. A plurality of groove portions respectively arranged between the convex units, a first surface arranged in each of the groove portions and facing one of the pair of convex units, and facing the first surface, A plurality of magnets each including a second surface facing the other of the convex units,
The first surface of each magnet is magnetized to a first magnetic pole,
The second surface of each magnet is magnetized to a second magnetic pole opposite to the first magnetic pole,
Magnetic power transmission structure.
A plurality of the convex portions of each convex unit are provided,
The plurality of protrusions of each of the protrusion units are arranged to be separated in the axial direction,
The magnetic power transmission structure according to claim 11.