WO2021149420A1

WO2021149420A1 - Electric motor with two degrees of freedom

Info

Publication number: WO2021149420A1
Application number: PCT/JP2020/047259
Authority: WO
Inventors: 禎之八田; 康孝藤本
Original assignee: 国立大学法人横浜国立大学
Priority date: 2020-01-22
Filing date: 2020-12-17
Publication date: 2021-07-29
Also published as: JPWO2021149420A1

Abstract

Provided is an electric motor (100) with two degrees of freedom that is able to achieve low loss and high output. The present invention has a first stator (10), a second stator (20), a first rotor (40), and a drive shaft (30). N-pole magnets (41) of N-pole regions of the first rotor (40) are arranged in a line along a right-tilting direction with intervals therebetween. S-pole magnets (42) of S-pole regions of the first rotor (40) are arranged in a line along the right-tilting direction with intervals therebetween, and are positioned so as not to overlap with the N-pole magnets (41) of the N-pole regions in a θ direction. N-pole magnets (31) of N-pole regions of the drive shaft (30) are positioned along the right-tilting direction and a Z-axis direction. S-pole magnets (32) of S-pole regions of the drive shaft (30) are positioned along the right-tilting direction and the Z-axis direction.

Description

2 degrees of freedom motor

The present invention relates to a two-degree-of-freedom motor.

In recent years, automation such as performing human work with robots has been promoted. In order to realize human work, the robot needs to be a multi-degree-of-freedom system composed of a plurality of degrees of freedom, but the number of motors mounted on the robot increases. As the number of motors increases, the size of the robot increases, so it is preferable that one motor can realize a plurality of degrees of freedom. Therefore, for example, Patent Document 1 discloses a two-degree-of-freedom motor (motor).

JP-A-2015-163004

Further improvements are desired in the motors used for robots and the like from the viewpoint of low loss and high output.

An object of the present invention is to provide a two-degree-of-freedom motor capable of achieving low loss and high output.

The invention disclosed in this application in order to solve the above problems has various aspects, and the outline of typical ones of these aspects is as follows.

(1) An annular first stator forming a rotating magnetic field, an annular second stator forming a rotating magnetic field, a plurality of first magnetic poles magnetized to the first polarity, and a second magnetic pole different from the first polarity. It includes a plurality of magnetically magnetized second magnetic poles and is provided with an annular gap with respect to the inner peripheral surface of the first stator, and is rotated by a rotating magnetic field formed by the first stator. It includes a moving annular first rotor, a plurality of the first magnetic poles, and a plurality of the second magnetic poles, and has an annular gap with respect to the inner peripheral surfaces of the first rotor and the second stator. The plurality of first magnetic poles of the first rotor have at least a drive shaft that is supported so as to be linearly movable and rotatably movable, and the plurality of first magnetic poles of the first rotor are inclined in the axial direction toward the circumferential direction. The plurality of second magnetic poles of the first rotor are arranged side by side with a distance from each other, and the plurality of second magnetic poles of the first rotor are spaced apart from each other along the direction in which the plurality of first magnetic poles of the first rotor are arranged. They are lined up and arranged so as not to overlap the plurality of first magnetic poles of the first rotor in the circumferential direction, and the plurality of first magnetic poles of the drive shaft intersect in the first direction and the first direction. A two-degree-of-freedom electric motor arranged along a second direction, and the plurality of second magnetic poles of the drive shaft are arranged along the first direction and the second direction.

In (2) and (1), the two-degree-of-freedom motor in which the first direction is the inclination direction and the second direction is the axial direction.

(3) In (2), the plurality of first magnetic poles of the drive shaft are arranged side by side at intervals along the inclination direction, and the plurality of second magnetic poles of the drive shaft are arranged side by side. The plurality of first magnetic poles of the drive shaft are arranged at intervals along the direction in which the plurality of first magnetic poles are arranged, and are arranged so as not to overlap the plurality of first magnetic poles of the drive shaft in the circumferential direction. Electric motor.

(4) In (1) to (3), in the drive shaft, the plurality of first magnetic poles and unmagnetized non-magnetized portions are alternately arranged in the inclined direction and the axial direction. A two-degree-of-freedom electric motor in which the plurality of second magnetic poles and the non-magnetized portion are alternately arranged in the inclined direction and the axial direction.

(5) In (1), the plurality of the first magnetic poles and the plurality of the second magnetic poles are included, and an annular gap is provided with respect to the inner peripheral surface of the second stator and the outer peripheral surface of the drive shaft. A two-degree-of-freedom motor further comprising an annular second rotor that is rotationally moved by a rotating magnetic field formed by the second stator.

(6) In (5), the first direction is the first inclination direction which is inclined in the first axial direction toward the first circumferential direction, and the second direction is the opposite direction of the first circumferential direction. It is a second tilting direction that tilts in the first axial direction toward a certain second circumferential direction, and the plurality of first magnetic poles of the first rotor are arranged at intervals along the first tilting direction. The plurality of second magnetic poles of the first rotor are arranged at intervals along the first inclination direction, and do not overlap with the plurality of first magnetic poles of the first rotor in the circumferential direction. The plurality of first magnetic poles of the second rotor are arranged at intervals along the second tilt direction, and the plurality of second magnetic poles of the second rotor are arranged in the second rotor direction. A two-degree-of-freedom electric motor arranged so as to be spaced apart from each other along the second inclination direction and not to overlap with the plurality of first magnetic poles of the two rotors in the circumferential direction.

(7) In (6), each of the plurality of first magnetic poles and the plurality of second magnetic poles of the drive shaft has an end portion along the first tilt direction and an end portion along the second tilt direction. A two-degree-of-freedom motor that has a shape.

(8) In (6) or (7), the plurality of first magnetic poles of the drive shaft are arranged at intervals in the axial direction, and the plurality of second magnetic poles of the drive shaft are shafts. Two-degree-of-freedom motors that are spaced apart from each other in the direction.

(9) In (6), each of the plurality of first magnetic poles and the plurality of second magnetic poles of the drive shaft has a shape having an end portion along the circumferential direction and an end portion along the axial direction. A two-degree-of-freedom motor in which the ends are alternately arranged so as to be adjacent to each other in the circumferential direction and the axial direction.

According to the aspects (1) to (9) of the present invention, it is possible to provide a two-degree-of-freedom motor capable of achieving low loss and high output.

It is a perspective view which shows the 2 degree of freedom motor which concerns on 1st Embodiment. It is a front view which shows the 2 degree of freedom motor which concerns on 1st Embodiment. FIG. 3 is a cross-sectional view taken along the line III-III cut surface of FIG. It is a perspective view which shows the 1st rotor of 1st Embodiment. It is a figure which shows the magnet arrangement of the drive shaft of 1st Embodiment, and is the development plan view of the outer peripheral surface of the drive shaft. It is a figure which shows the magnet arrangement of the drive shaft of 1st Embodiment, and is the development plan view of the outer peripheral surface of the drive shaft. It is a figure which shows the magnet arrangement of the 1st rotor of 1st Embodiment, and is the development plan view of the outer peripheral surface of the 1st rotor. It is a figure which shows the magnetic force acting on the drive shaft with the rotational movement of a 1st rotor. It is a perspective view which shows the 2 degree of freedom motor which concerns on 2nd Embodiment. It is a front view which shows the 2 degree of freedom motor which concerns on 2nd Embodiment. It is sectional drawing in the XI-XI cut plane of FIG. It is a figure which shows the magnet arrangement of the drive shaft of 2nd Embodiment, and is the development plan view of the outer peripheral surface of the drive shaft. It is a figure which shows the magnet arrangement of the drive shaft of 2nd Embodiment, and is the development plan view of the outer peripheral surface of the drive shaft. It is a figure which shows the magnet arrangement of the 1st rotor of 2nd Embodiment, and is the development plan view of the outer peripheral surface of the 1st rotor. It is a figure which shows the magnet arrangement of the 2nd rotor of 2nd Embodiment, and is the development plan view of the outer peripheral surface of the 2nd rotor. It is a figure which shows the magnetic force acting on the drive shaft with the rotational movement of a 1st rotor. It is a figure which shows the magnetic force acting on the drive shaft with the rotational movement of a 2nd rotor. It is a figure which shows the relationship between the phase angle [deg] of a 1st rotor and a 2nd rotor with respect to a drive shaft, and a thrust [N] when a 1st rotor and a 2nd rotor rotate in the same direction. It is a figure which shows the relationship between the phase angle [deg] of the 1st rotor and the 2nd rotor with respect to a drive shaft, and the rotational force [Nm] when the 1st rotor and the 2nd rotor rotate in the same direction. It is a figure which shows the magnetic force acting on the drive shaft with the rotational movement of a 2nd rotor. It is a figure which shows the relationship between the phase angle [deg] of the 1st rotor and the 2nd rotor with respect to a drive shaft, and a thrust [N] when the 1st rotor and the 2nd rotor rotate in opposite directions. It is a figure which shows the relationship between the phase angle [deg] of the 1st rotor and the 2nd rotor with respect to a drive shaft, and the rotational force [Nm] when the 1st rotor and the 2nd rotor rotate in opposite directions. .. It is a figure which shows the magnet arrangement of the drive shaft of the 1st modification of 2nd Embodiment, and is the development plan view of the outer peripheral surface of the drive shaft. It is a figure which shows the magnetizer which magnetizes the drive shaft of the 1st modification of 2nd Embodiment. It is a perspective view which shows the 2 degree of freedom motor which concerns on 2nd modification of 2nd Embodiment. It is a figure which shows the magnet arrangement of the drive shaft of the 2nd modification of 2nd Embodiment, and is the development plan view of the outer peripheral surface of the drive shaft. It is a figure which shows the magnet arrangement of the drive shaft of the 2nd modification of 2nd Embodiment, and is the development plan view of the outer peripheral surface of the drive shaft.

Hereinafter, each embodiment of the present invention will be described in detail based on the drawings.

[Overall configuration of the two-degree-of-freedom motor 100 according to the first embodiment]
First, with reference to FIGS. 1 to 4, an outline of the overall configuration of the two-degree-of-freedom motor according to the first embodiment will be described. FIG. 1 is a perspective view showing a two-degree-of-freedom motor according to the first embodiment. FIG. 2 is a front view showing a two-degree-of-freedom motor according to the first embodiment. FIG. 3 is a cross-sectional view taken along the line III-III cut surface of FIG. FIG. 4 is a perspective view showing the first rotor of the first embodiment.

The two-degree-of-freedom motor 100 is a so-called radial gap type motor, and has a first stator 10, a second stator 20, a drive shaft 30, and a first rotor 40, as shown in FIGS. 1 to 3.

The two-degree-of-freedom motor 100 is a motor capable of independently generating a thrust in the Z-axis direction and a rotational force in the θ direction. Here, the Z-axis direction is the direction in which the drive shaft 30 extends. In the first embodiment, as shown in FIG. 1 and the like, the direction from the first stator 10 side to the second stator 20 side is the + Z direction, and the opposite direction is the −Z direction. Further, the circumferential direction of the drive shaft 30 is set to the θ direction. In the first embodiment, as shown in FIG. 1 and the like, when the + Z direction is viewed, the clockwise direction is the + θ direction, and the opposite direction is the −θ direction.

[Outline of 1st stator 10 and 2nd stator 20]
The first stator 10 is annular and forms a rotating magnetic field. Specifically, in the first stator 10, a plurality of armatures (not shown) composed of a coil and an iron core around which the coil is wound are arranged at intervals in the θ direction, and the phases are sequentially arranged on the plurality of armatures. It is a structure that forms a rotating magnetic field by supplying a staggered current. The rotating magnetic field allows the first stator 10 to rotationally move the first rotor 40.

Similarly, the second stator 20 is annular and forms a rotating magnetic field. Specifically, in the second stator 20, a plurality of armatures (not shown) composed of a coil and an iron core around which the coil is wound are arranged at intervals in the θ direction, and the phases are sequentially arranged on the plurality of armatures. It is a structure that forms a rotating magnetic field by supplying a staggered current. The second stator 20 can drive the drive shaft 30 by the rotating magnetic field.

The first stator 10 and the second stator 20 are provided at different positions in the Z-axis direction. Further, the first stator 10 and the second stator 20 can be controlled independently.

[Overview of the first rotor 40]
As shown in FIG. 4, the first rotor 40 is an annular rotating body. Further, the first rotor 40 has an annular gap with respect to the outer peripheral surface of the drive shaft 30 and the inner peripheral surface of the first stator 10, and is rotatably supported. The first rotor 40 may be rotatably supported by a bearing (not shown) incorporated in the first stator 10.

On the outer peripheral surface of the first rotor 40, the north pole region including a plurality of north pole magnets 41 (first magnetic poles) magnetized on the north pole (first polarity) and the south pole (second polarity) are magnetized. It includes an S pole region including a plurality of S pole magnets 42 (second magnetic poles). In the inner peripheral surface of the first rotor 40, the portion corresponding to the north pole region of the outer peripheral surface is the south pole region, and the portion corresponding to the south pole region of the outer peripheral surface is the north pole region. That is, the inner peripheral surface of the N-pole magnet 41 is the S pole, and the inner peripheral surface of the S-pole magnet 42 is the N pole. The N-pole magnet 41 and the S-pole magnet 42 are preferably permanent magnets. The N-pole magnet 31 and the S-pole magnet 32, which will be described later, may also be permanent magnets.

As shown in FIG. 4, each of the plurality of N-pole magnets 41 and S-pole magnets 42 included in the first rotor 40 has an arc shape. Further, as shown in FIG. 4, the width of one N-pole magnet 41 and one S-pole magnet 42 in the θ direction is 45 °, and eight of these magnets are arranged to form one circumference of the first rotor 40. It was decided to. Note that FIG. 4 shows a configuration in which an N-pole magnet 41 and an S-pole magnet 42 that are adjacent to each other in the circumferential direction are connected to each other, but the present invention is not limited to this, and they may be separated from each other. In this case, the N-pole magnet 41 and the S-pole magnet 42 may be supported by a non-magnetized tubular housing or the like.

The north pole region and the south pole region of the first rotor 40 are provided so as to face the outer peripheral surface of the drive shaft 30 and the inner peripheral surface of the first stator 10, respectively. That is, the north pole region and the south pole region of the outer peripheral surface of the first rotor 40 are magnetically affected by the first stator 10, and the north pole region and the south pole region of the inner peripheral surface of the first rotor 40 are driven. It is provided so as to magnetically affect the shaft 30. The details of the magnet arrangement in the first rotor 40 will be described later.

The first rotor 40 rotates relative to the first stator 10 by the same drive system as the so-called SPM (Surface Permanent Magnet Motor) motor. That is, the position of the magnetic flux formed by the phase change of the three-phase current supplied to the armature of the first stator 10 of the first rotor 40 changes, and the first rotor 40 rotates and moves with the change of the position of the magnetic flux.

[Overview of drive shaft 30]
The drive shaft 30 is arranged with an annular gap with respect to the inner peripheral surfaces of the first stator 10 and the second stator 20. Further, on the outer peripheral surface of the drive shaft 30, an N-pole region including a plurality of N-pole magnets 31 magnetized on the N-pole and an S-pole region including an S-pole magnet 32 magnetized on the S pole are provided. ing. Further, as shown in FIG. 1, the width of one N-pole magnet 31 and one S-pole magnet 32 in the θ direction is 90 °, and four of these magnets are arranged to form one circumference of the drive shaft 30. I decided. The details of the magnet arrangement on the drive shaft 30 will be described later.

The N-pole region on the outer peripheral surface of the drive shaft 30 receives a repulsive force from the N-pole region on the inner peripheral surface of the first rotor 40 and a force attracted to the S-pole region on the inner peripheral surface of the first rotor 40. Further, the S pole region on the outer peripheral surface of the drive shaft 30 receives a force attracted to the N pole region on the inner peripheral surface of the first rotor 40, and also receives a repulsive force from the S pole region on the inner peripheral surface of the first rotor 40. receive. When a phase difference occurs in the θ direction between the magnet arrangement of the first rotor 40 and the magnet arrangement of the drive shaft 30 due to the rotational movement of the first rotor 40, the drive shaft 30 repels the first rotor 40. You will receive the power to do and the power to attract. As a result, the drive shaft 30 is driven.

[Magnet arrangement of drive shaft 30]
5 and 6 are views showing the magnet arrangement of the drive shaft of the first embodiment, and are developed plan views of the outer peripheral surface of the drive shaft. In FIGS. 5 and 6, the N-pole magnet 31 is shown by narrow diagonal lines, and the S-pole magnet 32 is shown by hatching consisting of a plurality of wide diagonal lines, and the unmagnetized portion (hereinafter, non-magnetized portion) is shown. The magnetized part) is shown in white.

As shown in FIG. 5, the drive shaft 30 has an N-pole region extending along the right inclination direction (first direction) and an S-pole region extending along the N-pole region on the outer peripheral surface thereof. The north pole region and the south pole region are arranged alternately. Here, the rightward tilting direction is defined as a direction that tilts in the + Z direction toward the + θ direction (first circumferential direction). Further, the left tilt direction described later is defined as a direction that tilts in the + Z direction toward the −θ direction (second circumferential direction). Further, in the first embodiment, as shown in FIG. 5, the inclination angle in the right inclination direction with respect to the θ direction is α.

In the first embodiment, the N-pole region is a band-shaped region including the N-pole magnet 31 and the non-magnetized portion 33. Similarly, the S pole region is a band-shaped region including the S pole magnet 32 and the non-magnetized portion 34.

In the N-pole region, the N-pole magnets 31 are arranged side by side at intervals along the right-inclining direction. Further, in the N-pole region, the non-magnetized portions 33 are arranged side by side at intervals from each other along the right-inclining direction. As described above, in the N-pole region, the N-pole magnet 31 and the non-magnetized portion 33 are alternately arranged side by side.

In the S pole region, S pole magnets 32 are arranged side by side at intervals along the right inclination direction. Further, in the S pole region, the non-magnetized portions 34 are arranged side by side at intervals from each other along the right inclination direction. In this way, in the S pole region, the S pole magnet 32 and the non-magnetized portion 34 are arranged alternately side by side.

Further, the N-pole magnet 31 included in the N-pole region of the drive shaft 30 and the non-magnetized portion 34 included in the S-pole region of the drive shaft 30 are arranged alternately in the Z-axis direction. Similarly, the S-pole magnet 32 included in the S-pole region of the drive shaft 30 and the non-magnetized portion 33 included in the N-pole region of the drive shaft 30 are arranged alternately in the Z-axis direction.

That is, as shown in FIG. 6, the drive shaft 30 has an N-pole region extending along the Z-axis direction (a second direction intersecting the first direction) and an S-pole region extending along the Z-axis direction. It can also be regarded as a configuration that includes. The N-pole region extending along the Z-axis direction is a region including the N-pole magnet 31 and the non-magnetized portion 34. The S pole region extending along the Z-axis direction is a region including the S pole magnet 32 and the non-magnetized portion 33.

Further, in the drive shaft 30, the planar shapes of the N-pole magnet 31, the S-pole magnet 32, and the

non-magnetized portions

33, 34 in the developed plan view are respectively extended in the Z-axis direction and tilted to the right. It was a parallelogram including a side (end) extending in the direction.

[Magnetic arrangement of the first rotor 40]
FIG. 7 is a view showing the magnet arrangement of the first rotor of the first embodiment, and is a developed plan view of the outer peripheral surface of the first rotor. The first rotor 40 has a magnetic pole arrangement similar to that shown in FIG. 7 even when viewed from the inner peripheral surface side. In FIG. 7, similarly to FIG. 5 and the like, the N-pole magnet 41 is shown by a plurality of narrow diagonal lines, the S-pole magnet 42 is shown by a plurality of wide diagonal lines, and the non-magnetized portion 43 is white. Shown without.

In the first embodiment, the magnet arrangement of the first rotor 40 is substantially the same as the magnet arrangement of the drive shaft 30. That is, in the first rotor 40, the plurality of N-pole magnets 41 are arranged so as to be arranged at intervals along the right-inclining direction and at intervals along the Z-axis direction. Further, the plurality of S pole magnets 42 are also arranged so as to be arranged at intervals along the right-inclining direction and at intervals along the Z-axis direction. Further, the N-pole magnet 41 is arranged so as not to overlap with the S-pole magnet 42 in the θ direction.

Further, the shapes of the N-pole magnet 41 and the S-pole magnet 42 of the first rotor 40 are almost the same as those of the N-pole magnet 31 and the S-pole magnet 32 of the drive shaft 30.

[Drive principle of drive shaft 30: θ direction]
The drive shaft 30 rotates relative to the second stator 20 in the same drive system as the so-called SPM (Surface Permanent Magnet Motor) motor. That is, when a rotating magnetic field is formed by passing an electric current through the second stator 20, a force in the θ direction acts on the drive shaft 30. As a result, the drive shaft 30 rotates and moves in the θ direction. By changing the direction of the current flowing through the second stator 20, the drive shaft 30 can be rotationally moved in either the + θ direction or the −θ direction.

As described above, in the two-degree-of-freedom motor 100 according to the first embodiment, the drive shaft 30 can be rotationally moved by driving the second stator 20 without driving the first stator 10. That is, the rotational force in the θ direction can be generated independently.

[Drive principle of drive shaft: Z-axis direction]
FIG. 8 is a diagram showing the magnetic force acting on the drive shaft 30 as the first rotor 40 rotates and moves. As described above, when a rotating magnetic field is formed by the first stator 10, a rotational force in the θ direction acts on the first rotor 40. The rotational movement of the first rotor 40 in the θ direction causes a phase difference in the θ direction between the magnet arrangement of the first rotor 40 and the magnet arrangement of the drive shaft 30. At that time, a magnetic force is generated on the drive shaft 30.

Specifically, when the first rotor 40 rotates in the −θ direction, a magnetic force F is generated on the drive shaft 30 in a direction orthogonal to the right tilting direction, as shown in FIG. As shown in FIG. 8, the magnetic force F is the resultant force of the thrust F × cos α acting in the + Z direction and the rotational force F × sin α acting in the −θ direction.

The magnetic force F is generated according to the _{phase difference θ mr1} shown in the equation (1). In the formula (1), θ _r1 and θ _m indicate the rotation angles of the first rotor 40 and the drive shaft 30 in the θ direction, and z _m indicates the position of the drive shaft 30 in the Z axis direction. Further, θ _rp and θ _mp indicate the period of magnet arrangement (width of one magnet in the θ direction) of each of the first rotor 40 and the drive shaft 30 in the θ direction. l _p indicates the period of magnet arrangement in the Z-axis direction (width of one magnet in the Z-axis direction). In the first embodiment, θ _rp = 45 ° and θ _mp = 90 °.

[Number 1]
θ _mr1 = θ _r1 _{-θ m} + (π / l _p ) × z _m ... (1)

As described above, in the configuration of the first embodiment, the drive shaft 30 has a rotational force in the θ direction due to the rotating magnetic field formed by the second stator 20 and a Z-axis direction generated by the rotational movement of the first rotor 40. Thrust and rotational force in the θ direction act.

In order to move the drive shaft 30 independently and linearly, the rotational force in the θ direction due to the rotating magnetic field formed by the second stator 20 and the rotational force F × Sinα in the −θ direction generated by the rotational movement of the first rotor 40 are required. It is preferable to control the first stator 10 and the second stator 20 so as to cancel each other out. When the rotational forces cancel each other out, the drive shaft 30 only moves linearly relative to the first stator 10 and the second stator 20. As a result, thrust in the Z-axis direction can be generated independently.

In the two-degree-of-freedom motor 100, since the first stator 10, the second stator 20, the first rotor 40, and the drive shaft 30 are physically non-contact with each other, loss due to friction can be prevented. As a result, high output can be realized. Further, by adopting a configuration in which two stators, which are output units, are provided, it is possible to output a higher output. Further, since the magnets included in the first rotor 40 and the drive shaft 30 are rectangular, the configuration is simpler and easier to manufacture as compared with the configuration in which the spiral magnet is adopted. Further, since the north pole region and the south pole region of the first rotor 40 and the drive shaft 30 include a non-magnetized portion, the amount of magnets used can be reduced. As a result, the cost can be reduced.

[Overall configuration of the two-degree-of-freedom motor 200 according to the second embodiment]
Next, the two-degree-of-freedom motor 200 according to the second embodiment will be described with reference to FIGS. 9 to 22. The definitions of each direction such as the Z-axis direction, the θ direction, and the rightward inclination direction are the same as those in the first embodiment, and the description thereof will be omitted. Further, the N-pole magnet and the S-pole magnet will be described with reference to the same reference numerals as those in the first embodiment.

FIG. 9 is a perspective view showing a two-degree-of-freedom motor according to the second embodiment. FIG. 10 is a front view showing a two-degree-of-freedom motor according to the second embodiment. FIG. 11 is a cross-sectional view of the XI-XI cut plane of FIG. FIG. 12 is a view showing the magnet arrangement of the drive shaft of the second embodiment, and is a developed plan view of the outer peripheral surface of the drive shaft. FIG. 13 is a view showing the magnet arrangement of the drive shaft of the second embodiment, and is a developed plan view of the outer peripheral surface of the drive shaft. FIG. 14 is a view showing the magnet arrangement of the first rotor of the second embodiment, and is a developed plan view of the outer peripheral surface of the first rotor. FIG. 15 is a view showing the magnet arrangement of the second rotor of the second embodiment, and is a developed plan view of the outer peripheral surface of the second rotor.

The two-degree-of-freedom motor 200 is an electric motor capable of independently generating a thrust in the Z-axis direction and a rotational force in the θ direction, similar to the two-degree-of-freedom motor 100. The two-degree-of-freedom motor 200 has a first stator 210, a second stator 220, a drive shaft 230, a first rotor 240, and a second rotor 250.

[Overview of 1st stator 210 and 2nd stator 220]
The first stator 210 has a different number of slots from the first stator 10 shown in FIG. 1 and the like, but has the same other basic structures, is annular, and forms a rotating magnetic field. The first stator 210 can drive the first rotor 240 by forming a rotating magnetic field.

Similarly, the second stator 220 has a different number of slots from the second stator 220 shown in FIG. 1 and the like, but has the same other basic structures, is annular, and forms a rotating magnetic field. .. The second stator 220 can drive the second rotor 250 by forming a rotating magnetic field.

The first stator 210 and the second stator 220 are provided at different positions in the Z-axis direction. Further, the first stator 210 and the second stator 220 can be controlled independently.

[Overview of the first rotor 240 and the second rotor 250]
Although the appearance is not shown, the first rotor 240 is an annular rotating body. Further, the first rotor 240 has an annular gap with respect to the outer peripheral surface of the drive shaft 230 and the inner peripheral surface of the first stator 210, and is rotatably supported.

The second rotor 250 is also an annular rotating body. The second rotor 250 has an annular gap with respect to the outer peripheral surface of the drive shaft 230 and the inner peripheral surface of the second stator 220, and is rotatably supported.

The first rotor 240 has a band-shaped N-pole region including a plurality of N-pole magnets 41 magnetized on the N-pole and a band-shaped S including a plurality of S-pole magnets 42 magnetized on the S-pole on the outer peripheral surface. Includes polar region. In the inner peripheral surface of the first rotor 240, the portion corresponding to the north pole region of the outer peripheral surface is the south pole region, and the portion corresponding to the south pole region of the outer peripheral surface is the north pole region. That is, the inner peripheral surface of the N-pole magnet 41 is the S pole, and the inner peripheral surface of the S-pole magnet 42 is the N pole.

The north pole region and the south pole region of the first rotor 240 are provided so as to face the outer peripheral surface of the drive shaft 230 and the inner peripheral surface of the first stator 210, respectively. That is, the north pole region and the south pole region of the outer peripheral surface of the first rotor 240 are magnetically affected by the first stator 210, and the north pole region and the south pole region of the inner peripheral surface of the first rotor 240 are driven. It is provided so as to magnetically affect the shaft 230. The details of the magnet arrangement in the first rotor 240 will be described later.

Similarly, the second rotor 250 has a band-shaped N-pole region containing a plurality of N-pole magnets 41 magnetized on the N-pole and a band-shaped S-pole containing a plurality of S-pole magnets 42 magnetized on the S pole. Includes area.

The north pole region and the south pole region of the second rotor 250 are provided so as to face the outer peripheral surface of the drive shaft 230 and the inner peripheral surface of the second stator 220, respectively. That is, the north pole region and the south pole region of the second rotor 250 are magnetically affected by the second stator 220 and magnetically with respect to the north pole region and the south pole region drive shaft 230 of the second rotor 250. It is provided to influence. The details of the magnet arrangement in the second rotor 250 will be described later.

As shown in FIG. 10, each of the plurality of N-pole magnets 41 and S-pole magnets 42 included in the second rotor 250 has an arc shape. Further, as shown in FIG. 10, the width of one N-pole magnet 41 and one S-pole magnet 42 in the θ direction is 45 °, and eight of these magnets are arranged to form one circumference of the second rotor 250. It was decided to. The same applies to the first rotor 240.

[Overview of drive shaft 230]
The drive shaft 230 is arranged with an annular gap with respect to the inner peripheral surfaces of the first rotor 240 and the second rotor 250. Further, on the outer peripheral surface of the drive shaft 230, a band-shaped N-pole region including a plurality of N-pole magnets 31 magnetized on the N-pole and a band-shaped S-pole including an S-pole magnet 32 magnetized on the S pole The area is provided. Further, in the drive shaft 230, the width of one N-pole magnet 31 and one S-pole magnet 32 in the θ direction is 180 °, and two of these magnets are arranged side by side to form one circumference of the drive shaft 230. And said. The details of the magnet arrangement on the drive shaft 230 will be described later.

The N-pole region on the outer peripheral surface of the drive shaft 230 receives a repulsive force from the N-pole region on the inner peripheral surfaces of the first rotor 240 and the second rotor 250, and the inner peripheral surfaces of the first rotor 240 and the second rotor 250. Receives a force that attracts the S pole region of. Further, the S pole region on the outer peripheral surface of the drive shaft 230 receives a force attracting the N pole region on the inner peripheral surfaces of the first rotor 240 and the second rotor 250, and the inner circumference of the first rotor 240 and the second rotor 250. Receives a repulsive force from the S pole region of the surface.

When a phase difference occurs in the θ direction between the magnet arrangement of the first rotor 240 and the magnet arrangement of the drive shaft 230 due to the rotational movement of the first rotor 240, the drive shaft 330 repels the first rotor 240. You will receive the power to do and the power to attract. Further, when a phase difference occurs in the θ direction between the magnet arrangement of the second rotor 250 and the magnet arrangement of the drive shaft 230 due to the rotational movement of the second rotor 250, the drive shaft 230 is moved from the second rotor 250. It will receive the above-mentioned repulsive force and attractive force. In this way, the drive shaft 230 is driven by receiving a magnetic force from the first rotor 240 and the second rotor 250.

[Magnet arrangement of drive shaft 230]
12 and 13 are views showing the magnet arrangement of the drive shaft of the second embodiment, and are developed plan views of the outer peripheral surface of the drive shaft. In FIGS. 12 and 13, the N-pole magnet 31 is shown by narrow diagonal lines, the S-pole magnet 32 is shown by hatching consisting of a plurality of wide diagonal lines, and the non-magnetized portion is shown in white. There is.

As shown in FIG. 12, the drive shaft 230 has an N-pole region extending along the right inclination direction and an S-pole region extending along the N-pole region on the outer peripheral surface thereof. The north pole region and the south pole region are arranged alternately. Further, in the second embodiment, as shown in FIG. 12, the inclination angle in the right inclination direction with respect to the θ direction is α.

In the second embodiment, the N-pole region is a region including the N-pole magnet 31 and the non-magnetized portion 33. Similarly, the S pole region is a region including the S pole magnet 32 and the non-magnetized portion 34.

Further, the N-pole magnet 31 included in the N-pole region of the drive shaft 230 and the non-magnetized portion 34 included in the S-pole region of the drive shaft 230 are arranged alternately side by side in the left inclination direction. Similarly, the S pole magnet 32 included in the S pole region of the drive shaft 230 and the non-magnetized portion 33 included in the N pole region of the drive shaft 230 are arranged alternately side by side in the left inclination direction.

That is, as shown in FIG. 13, the drive shaft 230 can be regarded as having a configuration including an N pole region extending along the left tilt direction and an S pole region extending along the left tilt direction. The north pole region extending along the left inclination direction is a region including the north pole magnet 31 and the non-magnetized portion 34. The S pole region extending along the left inclination direction is a region including the S pole magnet 32 and the non-magnetized portion 33.

Further, in the drive shaft 230, the planar shapes of the N-pole magnet 31, the S-pole magnet 32, and the

non-magnetized portions

33, 34 in the developed plan view are respectively extended to the right and tilted to the left. A parallelogram (diamond) including a side (end) extending in the direction was used.

[Magnetic arrangement of the first rotor 240]
FIG. 14 is a view showing the magnet arrangement of the first rotor of the second embodiment, and is a developed plan view of the outer peripheral surface of the first rotor. The first rotor 240 has the magnet arrangement shown in FIG. 14 even when viewed from the inner peripheral surface side.

In the second embodiment, the magnet arrangement of the first rotor 240 is the same as that of the first rotor 40 of the first embodiment. That is, in the first rotor 240, the plurality of N-pole magnets 41 are arranged so as to be arranged at intervals along the right inclination direction (first inclination direction) and along the Z-axis direction. Similarly, the plurality of S pole magnets 42 are arranged so as to be arranged at intervals along the right inclination direction and along the Z-axis direction. Further, the N-pole magnet 41 is arranged so as not to overlap with the S-pole magnet 42 in the θ direction.

[Magnetic arrangement of the second rotor 250]
FIG. 15 is a view showing the magnet arrangement of the second rotor of the second embodiment, and is a developed plan view of the outer peripheral surface of the second rotor. The second rotor 250 has the magnet arrangement shown in FIG. 15 even when viewed from the inner peripheral surface side.

In the second rotor 250, as shown in FIG. 15, the plurality of N-pole magnets 41 are arranged at intervals along the left inclination direction (second inclination direction) and are arranged along the Z-axis direction. Have been placed. Similarly, the plurality of S pole magnets 42 are arranged so as to be arranged at intervals along the left inclination direction and along the Z-axis direction. Further, the N-pole magnet 41 is arranged so as not to overlap with the S-pole magnet 42 in the θ direction.

[Drive principle of drive shaft 230: θ direction]
FIG. 16 is a diagram showing the magnetic force acting on the drive shaft as the first rotor rotates and moves. FIG. 17 is a diagram showing a magnetic force acting on the drive shaft as the second rotor rotates and moves.

When a rotating magnetic field is formed by the first stator 210, a rotational force in the θ direction acts on the first rotor 240. The rotational movement of the first rotor 240 in the θ direction causes a phase difference in the θ direction between the magnet arrangement of the first rotor 240 and the magnet arrangement of the drive shaft 230. At that time, a magnetic force is generated on the drive shaft 230.

Specifically, when the first rotor 240 rotates in the −θ direction, a magnetic force F is generated on the drive shaft 230 in a direction orthogonal to the right tilting direction, as shown in FIG. As shown in FIG. 16, the magnetic force F is the resultant force of the thrust F × cos α acting in the + Z direction and the rotational force F × sin α acting in the −θ direction.

The magnetic force F shown in FIG. 16 is generated according to the _{phase difference θ mr1 shown in the above equation (1).} In the second embodiment, θ _rp = 90 ° and θ _mp = 180 °.

Further, when a rotating magnetic field is formed by the second stator 220, a rotational force in the θ direction acts on the second rotor 250. The rotational movement of the second rotor 250 in the θ direction causes a phase difference in the θ direction between the magnet arrangement of the second rotor 250 and the magnet arrangement of the drive shaft 230. At that time, a magnetic force is generated on the drive shaft 230.

Specifically, when the second rotor 250 rotates in the −θ direction, that is, when it rotates in the same direction as the first rotor 240, the drive shaft 230 has the drive shaft 230 with respect to the left tilt direction as shown in FIG. A magnetic force F is generated in the direction orthogonal to each other. As shown in FIG. 16, the magnetic force F is the resultant force of the thrust F × cos α acting in the −Z direction and the rotational force F × sin α acting in the −θ direction.

The magnetic force F shown in FIG. 17 is generated according to the _{phase difference θ mr2 shown in the equation (2).} In the formula (2), θ _r2 and θ _m indicate the rotation angles of the second rotor 250 and the drive shaft 230 in the θ direction, and z _m indicates the position of the drive shaft 230 in the Z axis direction. Further, θ _rp and θ _mp indicate the period of magnet arrangement (width of one magnet in the θ direction) of each of the second rotor 250 and the drive shaft 230 in the θ direction. l _p indicates the period of magnet arrangement in the Z-axis direction (width of one magnet in the Z-axis direction). In the second embodiment, θ _rp = 90 ° and θ _mp = 180 °.

[Number 2]
θ _mr2 = θ _r2 _{-θ m-} (π / l _p ) × z _m ... (2)

As described above, in the configuration of the second embodiment, the drive shaft 230 has the thrust in the Z-axis direction and the rotational force in the θ direction generated by the rotational movement of the first rotor 240, and the rotational movement of the second rotor 250. The thrust in the Z-axis direction and the rotational force in the θ direction, which are generated by the above, act.

In order to rotate the drive shaft 230 independently, the thrust F × cos α in the + Z direction generated by the rotational movement of the first rotor 240 and the thrust F × cos α in the −Z direction generated by the rotation of the second rotor 250 cancel each other out. It is preferable to control the first stator 210 and the second stator 220 so as to match. When the thrusts cancel each other out, the drive shaft 230 only rotationally moves relative to the first stator 210 and the second stator 220. As a result, the rotational force in the θ direction can be generated independently.

FIG. 18 is a diagram showing the relationship between the phase angle [deg] of the first rotor and the second rotor with respect to the drive shaft and the thrust [N] when the first rotor and the second rotor rotate in the same direction. Is.

As shown in FIG. 18, the first stator 210 and the second stator 210 and the second stator 210 and the second are so that the thrust in the Z-axis direction generated by the rotational movement of the first rotor 240 and the thrust in the Z-axis direction generated by the rotation of the second rotor 250 cancel each other out. By controlling the stator 220, the drive shaft 230 does not move in the Z-axis direction.

FIG. 19 shows the relationship between the phase angle [deg] of the first rotor and the second rotor with respect to the drive shaft and the rotational force [Nm] when the first rotor and the second rotor rotate in the same direction. It is a figure.

As shown in FIG. 19, the drive shaft 230 is rotationally moved by the rotational force in the θ direction generated by the rotational movement of the first rotor 240 and the rotational force in the θ direction generated by the rotational movement of the second rotor 250.

[Drive principle of drive shaft 230: Z-axis direction]
FIG. 20 is a diagram showing the magnetic force acting on the drive shaft as the second rotor rotates and moves.

When the second rotor 250 rotates in the + θ direction, that is, when it rotates in the direction opposite to that of the first rotor 240, the drive shaft 230 has a magnetic force in a direction orthogonal to the left tilt direction, as shown in FIG. F occurs. As shown in FIG. 20, the magnetic force F is the resultant force of the thrust F × cos α acting in the + Z direction and the rotational force F × sin α acting in the + θ direction.

In order to move the drive shaft 230 independently and linearly, a rotational force F × sin α in the −θ direction generated by the rotational movement of the first rotor 240 and a rotational force F × sin α in the + θ direction generated by the rotation of the second rotor 250. It is preferable to control the first stator 210 and the second stator 220 so that the two stators cancel each other out. Since the rotational forces cancel each other out, the drive shaft 230 moves only linearly relative to the first stator 210 and the second stator 220. Thereby, the thrust in the Z direction can be generated independently.

FIG. 21 shows the relationship between the phase angle [deg] of the first rotor and the second rotor with respect to the drive shaft and the thrust [N] when the first rotor and the second rotor rotate in opposite directions. It is a figure.

As shown in FIG. 21, the drive shaft 230 moves in the linear direction due to the thrust in the Z-axis direction generated by the rotational movement of the first rotor 240 and the thrust in the Z-axis direction generated by the rotation of the second rotor 250.

FIG. 22 shows the relationship between the phase angle [deg] of the first rotor and the second rotor with respect to the drive shaft and the rotational force [Nm] when the first rotor and the second rotor rotate in opposite directions. It is a figure which shows.

As shown in FIG. 22, the first stator 210 and the second stator 210 and the second stator 210 and the second are so that the rotational force in the θ direction generated by the rotational movement of the first rotor 240 and the rotational force in the θ direction generated by the rotation of the second rotor 250 cancel each other out. By controlling the stator 220, the drive shaft 230 does not rotate in the θ direction.

[First modification of the second embodiment]
FIG. 23 is a view showing the magnet arrangement of the drive shaft of the first modification of the second embodiment, and is a developed plan view of the outer peripheral surface of the drive shaft. The two-degree-of-freedom motor according to the first modification of the second embodiment has the same configuration as the drive shaft 230 shown in FIGS. 9 to 17, except that the magnet arrangement in the drive shaft 330 is different. ..

As shown in FIG. 23, the drive shaft 330 includes an N-pole region and an S-pole region on the outer peripheral surface thereof, similarly to the drive shaft 230. In the N-pole region, the N-pole magnet 31 is arranged along the right-tilt direction and the left-tilt direction. Similarly, in the S pole region, the S pole magnet 32 is arranged along the right tilt direction and the left tilt direction. That is, the N-pole magnet 31 and the S-pole magnet 32 are parallelograms (diamonds) including sides (ends) along the right-tilt direction and the left-tilt direction.

Further, the plurality of N pole magnets 31 are arranged at intervals in the Z-axis direction. Similarly, the plurality of S pole magnets 32 are arranged at intervals in the Z-axis direction.

In the drive shaft 330, similarly to the drive shaft 230, the thrust in the Z-axis direction and the rotational force in the θ direction act due to the rotational movement of the first rotor 240 and the second rotor 250. Thereby, linear movement or rotational movement can be generated independently.

FIG. 24 is a diagram showing a porcelain that magnetizes the drive shaft of the first modification of the second embodiment. The magnetizer 80 is a device that generates a magnetic field that magnetizes the outer peripheral surface of the drive shaft 330. It has a plurality of magnetized portions 81 having a shape that conforms to the shape of the magnet included in the drive shaft 330. The outer peripheral surface of the drive shaft 330 is magnetized by arranging the drive shaft 330 whose outer peripheral surface is not magnetized on the magnetized portion 81 of the magnetizer 80 and generating a magnetic field. By using the magnetizer 80 shown in FIG. 24, it is possible to magnetize a half circumference of the drive shaft 330 by one magnetizing operation. Therefore, in the first modification of the second embodiment, the north pole region and the south pole region shown in FIG. 23 can be formed on the outer peripheral surface of the drive shaft 330 by two magnetizing operations.

In the configuration of the first modification of the second embodiment, as compared with the configuration shown in FIG. 16 and the like, the number of magnets used is small, so that the output is reduced, but the manufacturing process is simplified.

Next, the two-degree-of-freedom motor 300 according to the second modification of the second embodiment will be described with reference to FIGS. 25 to 27. FIG. 25 is a perspective view showing a two-degree-of-freedom motor according to a second modification of the second embodiment. 26 and 27 are views showing the magnet arrangement of the drive shaft of the second modification of the second embodiment, and are developed plan views of the outer peripheral surface of the drive shaft. The two-degree-of-freedom motor according to the second modification of the second embodiment is the same as the configuration shown in FIGS. 9 to 17, except that the magnet arrangement in the drive shaft 430 is different.

As shown in FIGS. 25 and 26, the drive shaft 430 includes an N-pole region and an S-pole region on the outer peripheral surface thereof, similarly to the drive shaft 230. The N-pole magnet 31 included in the N-pole region and the S-pole magnet 32 included in the S-pole region are rectangular (rectangular) including a side (end) along the Z-axis direction and a side (end) along the θ direction. be. Further, the N-pole magnet 31 and the S-pole magnet 32 are alternately arranged so as to be adjacent to each other at the ends in the θ direction and the Z-axis direction.

In the magnetic pole arrangement of the drive shaft 430, it is considered that the north pole region and the south pole region are magnetically provided along the right tilt direction and the left tilt direction with respect to the first rotor 240 and the second rotor 250. Can be done.

As shown in FIG. 27, since the N-pole magnet 31 and the S-pole magnet 32 are provided equivalently in the region surrounded by the thick line, the magnetic force received from the first rotor 240 and the second rotor 250 is applied in the region. It will be offset. That is, the region magnetically surrounded by the thick line with respect to the first rotor 240 and the second rotor 250 is a region equivalent to the non-magnetic pole portion. Therefore, in the magnet arrangement shown in FIG. 26, it can be regarded as magnetically equivalent to the magnet arrangement shown in FIG. 16 with respect to the first rotor 240 and the second rotor 250. Therefore, by using the drive shaft 430, the thrust in the Z-axis direction and the rotational force in the θ direction can be independently generated with the rotational movement of the first rotor 240 and the second rotor 250.

In the drive shaft 430, since the shape of each magnet is simpler than that of the drive shaft 230, processing is easy and the manufacturing cost can be suppressed.

Although each embodiment and modification according to the present invention have been described above, the specific configuration shown in each of these embodiments and modification is shown as an example, and the technical scope of the present invention is limited thereto. It is not intended to be done. Those skilled in the art may appropriately modify these disclosed embodiments, and it should be understood that the technical scope of the invention disclosed herein also includes such modifications.

Claims

An annular first stator forming a rotating magnetic field and
An annular second stator that forms a rotating magnetic field,
A plurality of first magnetic poles magnetized to the first polarity and a plurality of second magnetic poles magnetized to a second polarity different from the first polarity are included with respect to the inner peripheral surface of the first stator. An annular first rotor that is provided with an annular gap and that rotates and moves due to a rotating magnetic field formed by the first stator.
A plurality of the first magnetic poles and a plurality of the second magnetic poles are included, and the first rotor and the second stator are provided with an annular gap with respect to the inner peripheral surfaces of the first rotor and the second stator. A drive shaft that is rotatably supported and
Have at least
The plurality of first magnetic poles of the first rotor are arranged side by side at intervals from each other along an inclination direction in which the first magnetic poles are inclined in the axial direction toward the circumferential direction.
The plurality of second magnetic poles of the first rotor are arranged at intervals along the direction in which the plurality of first magnetic poles of the first rotor are arranged, and the plurality of first magnetic poles of the first rotor are arranged in the circumferential direction. It is arranged so that it does not overlap with one magnetic pole,
The plurality of first magnetic poles of the drive shaft are arranged along a first direction and a second direction intersecting the first direction.
The plurality of second magnetic poles of the drive shaft are arranged along the first direction and the second direction.
2 degree of freedom motor.
The first direction is the inclination direction.
The second direction is the axial direction,
The two-degree-of-freedom motor according to claim 1.
The plurality of first magnetic poles of the drive shaft are arranged side by side at intervals along the inclination direction.
The plurality of second magnetic poles of the drive shaft are arranged at intervals along the direction in which the plurality of first magnetic poles of the drive shaft are arranged, and are arranged with the plurality of first magnetic poles of the drive shaft in the circumferential direction. Arranged so that they do not overlap,
The two-degree-of-freedom motor according to claim 2.
In the drive shaft, the plurality of first magnetic poles and unmagnetized non-magnetized portions are alternately arranged in the inclined direction and the axial direction, and the plurality of second magnetic poles and the non-magnetized portion are arranged alternately. Are alternately arranged in the inclined direction and the axial direction.
The two-degree-of-freedom motor according to any one of claims 1 to 3.
A plurality of the first magnetic poles and the plurality of second magnetic poles are included, and are provided with an annular gap with respect to the inner peripheral surface of the second stator and the outer peripheral surface of the drive shaft. Further having an annular second rotor that is rotationally moved by a rotating magnetic field formed by the second stator.
The two-degree-of-freedom motor according to claim 1.
The first direction is a first inclination direction that inclines in the first axial direction toward the first circumferential direction.
The second direction is a second inclination direction that inclines in the first axial direction toward the second circumferential direction, which is the opposite direction of the first circumferential direction.
The plurality of first magnetic poles of the first rotor are arranged at intervals along the first tilt direction.
The plurality of second magnetic poles of the first rotor are arranged so as to be spaced apart from each other along the first inclination direction and do not overlap with the plurality of first magnetic poles of the first rotor in the circumferential direction. And
The plurality of first magnetic poles of the second rotor are arranged so as to be spaced apart from each other along the second inclination direction.
The plurality of second magnetic poles of the second rotor are arranged so as to be spaced apart from each other along the second inclination direction and do not overlap with the plurality of first magnetic poles of the two rotors in the circumferential direction. Yes,
The two-degree-of-freedom motor according to claim 5.
Each of the plurality of first magnetic poles and the plurality of second magnetic poles of the drive shaft has a shape having an end portion along the first tilt direction and an end portion along the second tilt direction.
The two-degree-of-freedom motor according to claim 6.
The plurality of first magnetic poles of the drive shaft are arranged so as to be spaced apart from each other in the axial direction.
The plurality of second magnetic poles of the drive shaft are arranged so as to be spaced apart from each other in the axial direction.
The two-degree-of-freedom motor according to claim 6 or 7.
Each of the plurality of first magnetic poles and the plurality of second magnetic poles of the drive shaft has a shape having an end portion along the circumferential direction and an end portion along the axial direction, and each of the plurality of first magnetic poles and the plurality of second magnetic poles has a shape having an end portion along the circumferential direction. Alternating so that the ends are adjacent,
The two-degree-of-freedom motor according to claim 6.