vernier motor

Abstract

To provide a linear type vernier motor that can easily adjust the thrust and size of the motor and achieve low detent.SOLUTION: A movable element 30 that is configured as a field magnet is configured of a polar anisotropic magnet, etc. in which a permanent magnet 33 moves a magnetic flux to and from adjacent magnetic portions 34. For example, an inner portion 31a, which is a rear side portion of the permanent magnet 33 with respect to a stator 20, is configured of a non-magnetic material.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a linear Vernier motor.

Background Art

[0002] As a linear Vernier motor, it includes a stator in which a plurality of magnetic pole portions are arranged linearly, and a mover in which a plurality of magnetic pole portions are also arranged linearly and are combined to linearly operate with respect to the stator. The stator is composed of, for example, an armature having a magnetic pole portion with a coil. The mover is composed of, for example, a field magnet having a permanent magnet and a magnetic portion with a magnetic pole portion. Further, since the Vernier motor has a configuration in which a magnetic deceleration effect is obtained during magnetic transmission between the stator and the mover, a high linear thrust can be obtained (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in a conventional general configuration, the combination of the number of pole pairs of each magnetic pole of the stator and the mover that can achieve the desired low detent of the Vernier motor is limited. That is, in order to achieve the desired low detent of the Vernier motor, the number of magnetic poles is limited and the thrust and size of the motor become stepwise. Therefore, the inventor has been studying a configuration that can finely adjust them.

[0005] An object of the present disclosure is to provide a Vernier motor that can achieve low detent and easily adjust the thrust and size of the motor.

Means for Solving the Problems

[0006] The Vernier motor for solving the above problems includes an armature (20) in which a plurality of pairs of first magnetic pole parts (21) including coils (22) and magnetic members (23) are provided linearly, and a plurality of pairs of second magnetic pole parts (32) including permanent magnets (33, 33a to 33c) and magnetic parts (34) are provided linearly. A field magnet (30), and a magnetic deceleration effect is obtained when magnetic transmission occurs between the first and second magnetic pole parts based on energization of the coil, and a linear Vernier motor that obtains a linear thrust in the axial direction (L1) by the relative linear movement of the armature and the field magnet, wherein the field magnet is composed of a pole anisotropic magnet or a Halbach array magnet that allows magnetic flux to flow back and forth between the permanent magnet and the adjacent magnetic part, and relative to the armature to the the first located on the back side back side part (31a) and the second back side part (31b) located on the back side of the magnetic part with respect to the armature of at least a part of is formed of a non-magnetic part and the first back side part (31a) and the second back side part (31b) are separate members from each other .

[0007] According to the above configuration, the permanent magnet of the field magnet is composed of a pole anisotropic magnet or a Halbach array magnet, and magnetic flux induction is mainly performed so that magnetic flux flows back and forth between the permanent magnet and the adjacent magnetic part. Here, if a part of the magnetic flux passes through the back side part of the permanent magnet and the magnetic part and acts on the magnetic part and the permanent magnet that are farther away than the adjacent ones, it becomes a ripple, which can be a factor in increasing the ripple. Considering this, by configuring at least a part of the back side part of the permanent magnet and the magnetic part with respect to the armature as a non-magnetic part, it is possible to suppress the generation of unnecessary magnetic flux that leads to an increase in ripple. That is, the ripple can be suppressed to a small value and low detent can be achieved. In addition, even if the back side part of the permanent magnet and the magnetic part is a non-magnetic part, the influence on the thrust of the motor is small, and the thrust can be maintained. Thus, suppressing the thrust maintenance and the ripple rate without relying on the combination of the number of magnetic poles leads to an increase in the degree of freedom of the combination of the number of magnetic poles, and it can be said that the thrust and the physical size of the motor can be easily finely adjusted.

Brief Description of the Drawings

[0008]

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Embodiment for Carrying out the Invention

[0009] (First Embodiment) Hereinafter, a first embodiment of a Vernier motor will be described. (Overall Configuration of Vernier Motor M1) As shown in FIG. 1, the Vernier motor M1 of the present embodiment is configured as a linear type Vernier motor that obtains a linear thrust. The Vernier motor M1 includes a housing 10, a stator 20, and a mover 30. In the present embodiment, the stator 20 side is configured as an armature, and the mover 30 side is configured as a field magnet. The Vernier motor M1 is configured such that the mover 30 reciprocates linearly with respect to the stator 20 along its own axis L1 direction (hereinafter simply referred to as the axial direction).

[0010] (Configuration of Housing 10) The housing 10 includes a cylindrical case 11 extending along the axial direction and a pair of disk-shaped end housings 12 that close both ends of the case 11, respectively. Bearings 13 are provided at the centers of the end housings 12, respectively. The bearing 13 supports the mover 30 so as to be movable along the axial direction.

[0011] (Configuration of Stator 20) As shown in FIGS. 1 and 2, the stator 20 is fixed to the inner peripheral surface of the case 11. The stator 20 is configured in a substantially annular shape that extends along the axial direction as a whole. The stator 20 has an axial length shorter than the axial length of the case 11 in the same direction, and is configured to have a length of about 1 / 3 to 1 / 2, for example.

[0012] The stator 20 has six magnetic pole portions 21 (first magnetic pole portions) in the present embodiment. Each magnetic pole portion 21 is arranged so as to be linearly arranged in the axial direction. Each magnetic pole portion 21 is configured to have a magnetic pole of one pole pair. Each magnetic pole portion 21 includes a coil 22, a magnetic plate 23 (magnetic member), and a permanent magnet 24, respectively.

[0013] The coil 22 has a winding shape in which the conductor wire winds around the axis L1. Note that the coil 22 will be described including an insulator (not shown) made of an insulating resin material. Magnetic plates 23 are respectively arranged in contact with both sides of the coil 22 in the axial direction. The magnetic plate 23 is made into an annular plate shape from a magnetic metal material such as a soft magnetic material. The outer peripheral edge of the magnetic plate 23 is in contact with the inner peripheral surface of the case 11. The inner peripheral edge of the magnetic plate 23 faces the outer peripheral surface of the mover 30 with a predetermined gap therebetween.

[0014] On the radially inner side of the coil 22, the outer peripheral surface of a permanent magnet 24 is arranged in contact therewith. The permanent magnet 24 is made into an annular shape from one magnetic material. Also, both end faces of the permanent magnet 24 in the axial direction are respectively arranged in contact with the magnetic plates 23 on both sides of the coil 22. The inner peripheral surface of the permanent magnet 24 and the inner peripheral edge of the magnetic plate 23 are flush.

[0015] As shown in FIG. 3, the permanent magnet 24 has a magnetization pattern such that the magnetic flux at the axially central portion is locally directed radially on the inner peripheral surface facing the mover 30. The permanent magnet 24 of the present embodiment is composed of a magnet with pole anisotropy in which the inner peripheral surface of the central portion divided into three equal parts in the axial direction appears as an N pole, and both end faces in the axial direction in contact with the magnetic plate 23 appear as S poles. Also, in the present embodiment, one-third of the axial length of the permanent magnet 24 and the thickness of two magnetic plates 23 are configured to be equal.

[0016] As shown in FIG. 2, as the stator 20, the magnetic plates 23 of the magnetic pole portions 21 adjacent in the axial direction are arranged in contact with each other. Between the adjacent magnetic pole portions 21, the two magnetic plates 23 overlap. All six magnetic pole portions 21 used for the stator 20, including the permanent magnet 24, have the same configuration. Also, the coils 22 of the six magnetic pole portions 21 are set as U phase, -W phase, V phase, -U phase, W phase, -V phase in order from one side in the axial direction. Corresponding three-phase currents are supplied to the six coils 22. Thus, the stator 20 composed of the armature of the present embodiment is configured.

[0017] (Configuration of the mover 30) As shown in FIGS. 1 and 2, the mover 30 is configured in a substantially circular bar shape that extends long along the axial direction. The central portion of the mover 30 in the axial direction is disposed inside the stator 20 in the radial direction. The mover 30 is provided so as to be capable of reciprocating linearly in the axial direction with respect to the stator 20. The mover 30 includes a shaft portion 31 and a magnetic pole portion 32 (second magnetic pole portion). The shaft portion 31 is configured to be longer than the case 11 in the axial direction. Both axial ends of the shaft portion 31 are respectively supported by the bearings 13 of the end housings 12. A plurality of magnetic pole portions 32 are integrally provided at the central portion of the shaft portion 31 in the axial direction.

[0018] The plurality of magnetic pole portions 32 are arranged so as to be linearly aligned in the axial direction on the outer peripheral surface of the shaft portion 31. The total length of the plurality of magnetic pole portions 32 in the axial direction is configured to be longer than the length of the stator 20 in the same direction. The plurality of magnetic pole portions 32 are eight magnetic pole portions in the present embodiment. Five of the eight magnetic pole portions 32 are configured to have an axial length equal to the length of the stator 20 in the same direction. That is, the six magnetic pole portions 21 of the stator 20 and the five magnetic pole portions 32 of the mover 30 are always in a relationship of facing each other in the radial direction. When the number of pole pairs of the armature is "m" and the number of pole pairs of the field magnet is "n", "n = m ± 1" holds for a Vernier motor. The number of pole pairs of the magnetic pole portion 21 of the stator 20, which is the armature, is "m = 6", and the number of pole pairs of the magnetic pole portion 32 of the mover 30, which is the field magnet, is "n = 5", and this is satisfied in the present embodiment.

[0019] Each magnetic pole portion 32 includes a permanent magnet 33 and a magnetic portion 34, respectively. As a whole of the eight magnetic pole portions 32, the permanent magnets 33 and the magnetic portions 34 are alternately provided in the axial direction. Note that eight permanent magnets 33 are provided, and nine magnetic portions 34 are provided so as to be disposed on both sides of the permanent magnet 33. The permanent magnet 33 and the magnetic portion 34 are set to have the same axial length. One permanent magnet 33 and one adjacent magnetic portion 34 function as a pair of magnetic pole portions.

[0020] The permanent magnet 33 is formed in an annular shape from a single magnetic material. Both end faces of the permanent magnet 33 in the axial direction are respectively arranged in contact with the magnetic parts 34 on both sides. As shown in FIG. 3, the permanent magnet 33 has a magnetization pattern on the outer peripheral surface facing the stator 20 such that the magnetic flux at the central portion in the axial direction is locally directed radially. The permanent magnet 33 of the present embodiment is composed of a magnet with pole anisotropy such that the outer peripheral surface of the central portion divided into three equal parts in the axial direction appears as the S pole, and both end faces in the axial direction in contact with the magnetic parts 34 appear as the N pole.

[0021] As shown in FIGS. 2 and 4, the inner portion 31a of the permanent magnet 33 that constitutes a part of the shaft portion 31 is made of a non-magnetic metal material such as aluminum or SUS in the present embodiment. In the present embodiment, the permanent magnet 33 and the inner portion 31a are integrally fabricated by combining different materials.

[0022] The magnetic part 34 is formed in an annular shape from a magnetic metal material. The outer peripheral surface of the magnetic part 34 and the outer peripheral surface of the permanent magnet 33 are flush. The inner portion 31b of the magnetic part 34 that constitutes a part of the shaft portion 31 is made of a magnetic metal material in the present embodiment. In the present embodiment, the magnetic part 34 and the inner portion 31b are fabricated as an integral part from a single magnetic metal material such as a soft magnetic material.

[0023] Then, the entire magnetic pole portion 32 having eight permanent magnets 33 and nine magnetic parts 34 is accommodated in the cylindrical member 35. The cylindrical member 35 is formed in a cylindrical shape from a non-magnetic metal material such as aluminum or SUS. The cylindrical member 35 is fixed to each of the magnetic parts 34 located on both sides in the axial direction, for example, and is integrally configured. In this way, the mover 30 composed of the field magnet of the present embodiment is configured.

[0024] (Manufacturing procedure of the mover 30) As shown in FIGS. 1 and 4, in the mover 30 of the present embodiment, a disk-shaped component X1 in which the permanent magnet 33 and the inner portion 31a are integrally formed, and a disk-shaped component X2 in which the magnetic portion 34 and the inner portion 31b are integrally formed are used. Eight components X1 including the permanent magnet 33 and seven components X2 including the magnetic portion 34 are used. Further, a component X3 in which a disk portion composed of the magnetic portion 34 and the inner portion 31b is integrally formed is used for the shaft end portion constituting the end side portion of the shaft portion 31. Two components X3 are used. Then, the component X1 and the component X2 are alternately inserted into the cylindrical member 35 and stacked, and the component X3 is disposed on both axial sides. The permanent magnet 33 and the magnetic portion 34 are alternately arranged, and the inner portions 31a and 31b of the permanent magnet 33 and the magnetic portion 34 are integrated as the shaft portion 31. By fixing both axial end portions of the cylindrical member 35 to the magnetic portion 34 of the disk portion of the component X3 by caulking or the like, an integral mover 30 is manufactured.

[0025] (Operation of the present embodiment) The operation of the present embodiment will be described. In the Vernier motor M1 of the present embodiment, due to the above structure, when the mover 30 moves, for example, one magnetic pole portion 32 in one axial direction, the magnetic flux density distribution in the air gap moves six magnetic pole portions 21 of the stator 20 in the other axial direction (one block in this case). Since the six magnetic pole portions 21 of the stator 20 and the five magnetic pole portions 32 of the mover 30 are set to have the same length, the operation of the mover 30 due to one cycle change when current is applied to each coil 22 of the stator 20 is one magnetic pole portion 32. That is, the operation of the mover 30 is a decelerated operation by 1 / 5. In the Vernier motor M1 in which such a magnetic deceleration effect during magnetic transmission from the stator 20 to the mover 30 can be obtained, a high-thrust motor output can be obtained.

[0026] Also, in the present embodiment, a permanent magnet 33 of the mover 30 uses an anisotropic magnet or the like, and magnetic flux induction is mainly performed between the permanent magnet 33 and the adjacent magnetic part 34 so that magnetic flux travels back and forth. Here, if a part of the magnetic flux passes through the shaft part 31 inside the permanent magnet 33 and the magnetic part 34 in the radial direction and acts on the magnetic part 34 and the permanent magnet 33 that are farther away than the adjacent ones, it becomes ripple and can be a factor in increasing the ripple. Therefore, in the present embodiment, the inner part 31a of the permanent magnet 33 that constitutes a part of the shaft part 31 is made a non-magnetic part, and the back-and-forth movement of the magnetic flux between the distant magnetic part 34 and the permanent magnet 33 is suppressed. By optimizing the magnetic flux path in the mover 30 in this way, the generation of unnecessary magnetic flux that leads to an increase in ripple is suppressed.

[0027] FIG. 5 shows the thrust and ripple rate of the Vernier motor in each aspect. The first embodiment is shown at "A1". For the comparative examples "B" and "C" as comparison targets, in the comparative example "C", the magnetic pole part of the mover is composed only of the magnetic part 34 without using the permanent magnet 33 described above. Further, in the comparative example "B", the same permanent magnet 33 and magnetic part 34 as described above are used as the magnetic pole part of the mover, but the shaft part 31 such as the inner part 31a of the permanent magnet 33 is made of a magnetic metal material. The thrust of the comparative example "C" is set to "1", the magnitude of the ripple with respect to the unit thrust is defined as the ripple rate, and the ripple rate of the comparative example "C" is set to "1", and each aspect is compared. Note that the combination of the number of magnetic poles of the stator and the number of magnetic poles of the mover is the same setting.

[0028] In the comparative example "B", sufficient high thrust is obtained with respect to the comparative example "C", and the ripple rate is also greatly suppressed. However, in the aspect of the comparative example "B", since the shaft part 31 such as the inner part 31a of the permanent magnet 33 is a magnetic material, the suppression of the magnetic flux leading to ripple is not achieved, and there is still room for improvement particularly in terms of the ripple rate.

[0029] In contrast, in the first embodiment "A1" of the present invention, it is possible to suppress the ripple rate even more sufficiently than in the comparative example "B". Also, the combination of the number of poles of the stator 20 and the number of poles of the mover 30 in this embodiment is a combination that can originally have a small ripple rate. In other words, if the number of poles of each of the stator 20 and the mover 30 is changed, there is also a combination in which the ripple rate increases. Suppressing the ripple rate without relying on the combination of the number of poles as in this embodiment also leads to an increase in the degree of freedom in the combination of the number of poles. Moreover, in the first embodiment "A1", a high thrust equivalent to that of the comparative example "B" can be obtained, and it is possible to maintain the high thrust.

[0030] Note that in FIG. 5, the thrust and ripple rate of the second embodiment "A2" and the third embodiment "A3" described later are also shown together. (Effect of this embodiment) The effect of this embodiment will be described.

[0031] (1-1) The permanent magnet 33 of the mover 30 in this embodiment is composed of a radially anisotropic magnet, and magnetic flux induction is mainly performed so that magnetic flux travels back and forth between adjacent magnetic parts 34. As described above, if a part of the magnetic flux passes through the inner parts 31a and 31b, which are the back-side parts of the permanent magnet 33 and the magnetic part 34, and acts on the magnetic part 34 and the permanent magnet 33 that are farther away than the adjacent ones, it becomes ripple, which can be a factor in increasing the ripple. Considering this, in this embodiment, by configuring the inner part 31a of the permanent magnet 33 as a non-magnetic part, the generation of unnecessary magnetic flux that leads to an increase in ripple is suppressed. That is, the ripple can be suppressed to a small value, and low detent can be achieved. Also, the influence of making the inner part 31a of the permanent magnet 33 a non-magnetic part on the thrust of the Vernier motor M1 is small, and the thrust can be maintained. Suppressing the thrust maintenance and the ripple rate without relying on the combination of the number of poles in this way leads to an increase in the degree of freedom in the combination of the number of poles, and it can also be said that it is easy to finely adjust the thrust and physical size of the Vernier motor M1.

[0032] (1-2) The mover 30 includes a part where a component X1 as a first component including a permanent magnet 33 and a component X2 as a second component including a magnetic part 34 are stacked axially and is integrally formed. That is, since relatively small components X1 and X2 obtained by axially dividing the mover 30 into a plurality are handled, effects such as facilitation of manufacturing the mover 30 can be expected.

[0033] (1-3) The components X1 and X2 constituting a part of the mover 30 are housed in a cylindrical member 35 for integration. Therefore, effects such as easy assembly of each component X1 and X2 and easy regulation of the shape of the integrated part using each component X1 and X2 can be expected.

[0034] (1-4) Since the entire inner part 31a of the annular permanent magnet 33 becomes a non-magnetic part, effective suppression of unnecessary magnetic flux crossing the shaft part 31 can be achieved. It is possible to more reliably suppress ripple.

[0035] (Second Embodiment) Hereinafter, a second embodiment of the Vernier motor will be described. (Configuration of the Stator 20 and the Mover 30) As shown in FIGS. 6 and 7, the Vernier motor M2 of this embodiment is configured in the same manner as the first embodiment for the stator 20. For the mover 30, the inner part 31a of the permanent magnet 33 and the inner part 31b of the magnetic part 34 that constitute a part of the shaft part 31 are changed.

[0036] In this embodiment, the inner part 31a of the permanent magnet 33 is made of a magnetic metal material. The permanent magnet 33 and the inner part 31a are manufactured by integrally combining different materials. The inner part 31b of the magnetic part 34 is made of a non-magnetic metal material in this embodiment. The magnetic part 34 and the inner part 31b are manufactured by integrally combining different materials. That is, the inner parts 31a and 31b of the permanent magnet 33 and the magnetic part 34 are in a state swapped with those in the first embodiment. Also in this embodiment, the component X1 including the permanent magnet 33 and the component X2 including the magnetic part 34 are inserted into the cylindrical member 35, and the rotor 30 is integrally formed.

[0037] (Operation of this embodiment) The operation of this embodiment will be described. Also in this embodiment, the inner part 31b of the magnetic part 34 that constitutes a part of the shaft portion 31 of the rotor 30 is a non-magnetic part, and the reciprocation of magnetic flux between the distant magnetic part 34 and the permanent magnet 33 is suppressed. Also in this configuration, similar to the first embodiment, by optimizing the magnetic flux path in the rotor 30, the generation of unnecessary magnetic flux that would lead to an increase in ripple is suppressed.

[0038] Therefore, as shown in "A2" of the second embodiment in FIG. 5, similar to the first embodiment, it is possible to sufficiently suppress the ripple rate. This also leads to an increase in the degree of freedom in combining the number of magnetic poles of the stator 20 and the rotor 30. Moreover, it is possible to maintain a high thrust also in the second embodiment "A2".

[0039] (Effect of this embodiment) The effect of this embodiment will be described. (2-1) Also in this embodiment, the same effects as the effects (1-1) to (1-3) of the first embodiment can be obtained.

[0040] (2-2) Since the entire inner part 31b of the annular magnetic part 34 becomes a non-magnetic part, in this embodiment as well, effective suppression of unnecessary magnetic flux crossing the shaft part 31 can be achieved. Similar to the first embodiment, it is possible to more reliably suppress ripple.

[0041] (Third Embodiment) Hereinafter, a third embodiment of the Vernier motor will be described. (Configuration of the Stator 20 and the Rotor 30) As shown in FIGS. 8 and 9, the Vernier motor M3 of this embodiment is configured in the same manner as the first embodiment for the stator 20. For the rotor 30, both the inner parts 31a and 31b of the permanent magnet 33 and the magnetic part 34 that form part of the shaft part 31 are made of a non-magnetic metal material. The permanent magnet 33 and the inner part 31a are manufactured by integrally combining different materials. The same applies to the magnetic part 34 and the inner part 31b, which are manufactured by integrally combining different materials. Also in this embodiment, the component X1 including the permanent magnet 33 and the component X2 including the magnetic part 34 are inserted into the cylindrical member 35, and the rotor 30 is integrally formed.

[0042] (Operation of this Embodiment) The operation of this embodiment will be described. Also in this embodiment, both the inner parts 31a and 31b of the permanent magnet 33 and the magnetic part 34 that form part of the shaft part 31 of the rotor 30 are non-magnetic parts, and the reciprocation of magnetic flux between the distant magnetic part 34 and the permanent magnet 33 is suppressed. Also in this configuration, similar to the first embodiment, by optimizing the magnetic flux path in the rotor 30, the generation of unnecessary magnetic flux that leads to an increase in ripple is suppressed.

[0043] Therefore, as shown in "A3" of this third embodiment in FIG. 5, similar to the first and second embodiments, it is possible to sufficiently suppress the ripple rate. This also leads to an increase in the degree of freedom in combining the number of magnetic poles of the stator 20 and the rotor 30. Moreover, it is possible to maintain a high thrust also in this third embodiment "A3".

[0044] (Effects of the present embodiment) The effects of the present embodiment will be described. (3-1) Also in the present embodiment, the same effects as the effects (1-1) to (1-3) of the first embodiment can be obtained.

[0045] (3-2) Since the entire inner portions 31a and 31b of the annular permanent magnet 33 and the magnetic portion 34 are non-magnetic portions, an effective suppression of unnecessary magnetic flux crossing the shaft portion 31 can also be achieved in the present embodiment. Similar to the first embodiment, it is possible to more reliably suppress ripple.

[0046] (Modification example) Each of the above embodiments can be implemented with the following modifications. The above embodiments and the following modification examples can be implemented in combination with each other as long as they do not technically conflict.

[0047] · In the magnetic pole portion 32 of the mover 30, the component X1 having the permanent magnet 33 and the component X2 having the magnetic portion 34 are inserted into the cylindrical member 35 and integrally formed, but the components X1 and X2 may be fixed to each other using an adhesive. In this case, the cylindrical member 35 can also be omitted.

[0048] · As shown in FIG. 10, the shaft portion 31 of the mover 30 may be made from a single long shaft material, and the annular permanent magnet 33 and the annular magnetic portion 34 may be mounted on the outer peripheral surface. This mode is particularly applicable when both the inner portions 31a and 31b of the permanent magnet 33 and the magnetic portion 34 constituting a part of the shaft portion 31 are made of non-magnetic metal materials, as in the mover 30 of the third embodiment shown in FIG. 8. The shaft portion 31 can be made from a single long shaft material such as non-magnetic metal or non-magnetic resin. In this way, effects such as being able to increase the rigidity of the shaft portion 31 can be expected. Of course, as in the first and second embodiments shown in FIGS. 2 and 6, even if the inner portions 31a and 31b of the permanent magnet 33 and the magnetic portion 34 are made of different materials, a single long shaft portion 31 may be prepared in advance, and then the permanent magnet 33 and the magnetic portion 34 may be mounted.

[0049] · As shown in FIGS. 11 and 12, each permanent magnet 33a, 33b may be used for the mover 30. Although the permanent magnet 33 used for the mover 30 is composed of one anisotropic magnet, as shown in FIG. 11, a permanent magnet 33a composed of two anisotropic magnets divided in the axial direction may be used. Also, as shown in FIG. 12, a permanent magnet 33b composed of a Halbach array magnet of three magnetic materials divided in the axial direction may be used. Of course, each permanent magnet 33a, 33b has the same function as the above-described permanent magnet 33.

[0050] · As shown in FIG. 13, a permanent magnet 33c inclined so that both axial end faces expand toward the stator 20 side may be used. The permanent magnet 33c is composed of, for example, a Halbach array magnet. The permanent magnet 33c with inclined both axial end faces can be expected to have an effect of making the change in the axial magnetic flux distribution gentle.

[0051] · Although not shown, not only the change of each permanent magnet 33a to 33c of the permanent magnet 33 used for the mover 30, but also the permanent magnet 24 used for the stator 20 may be changed in the same manner as each permanent magnet 33a to 33c.

[0052] · As shown in FIG. 14, a slit 23a extending in the axial direction may be provided on the inner peripheral surface of the magnetic plate 23 of the stator 20, that is, the surface facing the mover 30. Also, a slit 34a extending in the axial direction may be provided on the outer peripheral surface of the magnetic portion 34 of the mover 30, the surface facing the stator 20. A plurality of each slit 23a, 34a are provided, for example, at equal intervals in the circumferential direction. Each slit 23a, 34a has the same function, and effects such as magnetic flux rectification can be expected. Although not shown, the same effect can be expected by providing ridges instead of each slit 23a, 34a.

[0053] · As shown in FIGS. 15 to 18, a mode in which long members 36a, 36b extending in the entire axial direction of the shaft portion 31 of the mover 30 are arranged inside the shaft portion 31 may be used. In the embodiments shown in FIGS. 15 and 16, the long member 36a is made of a non-magnetic material and also functions as a non-magnetic portion. If the long member 36a is made of a metallic material, effects such as enhancing the rigidity of the shaft portion 31 of the mover 30 can be expected. Also, if the long member 36a is made of a resin material, effects such as reducing the weight of the shaft portion 31 of the mover 30 can be expected. In the embodiments shown in FIGS. 17 and 18, the long member 36b is made of a magnetic material. If the long member 36b is made of a metallic material, effects such as enhancing the rigidity of the shaft portion 31 of the mover 30 can be expected. Note that the embodiments shown in FIGS. 15 and 17 are applications to the first embodiment in which the inner portion 31a of the permanent magnet 33 is a non-magnetic material. Also, the embodiments shown in FIGS. 16 and 18 are applications to the second embodiment in which the inner portion 31b of the magnetic portion 34 is a non-magnetic material.

[0054] Also, as shown in FIG. 19, a plurality of rod-shaped members 37a made of a non-magnetic material may be used as an example of the long member 36a. The plurality of rod-shaped members 37a are provided at equal intervals in the circumferential direction at an intermediate position in the radial direction of the shaft portion 31. Also, as shown in FIG. 20, a cylindrical member 37b made of a non-magnetic material may be used as an example of the long member 36a. Note that the inner portion 37c of the cylindrical member 37b may be formed of a magnetic material or may be formed as a void. Also, as shown in FIG. 21, a cylindrical member 37b and an inner portion 37c shown in FIG. 20 may both be made of a non-magnetic material, that is, a cylindrical member 37d may be used. The cylindrical member 37d is provided at the center of the shaft portion 31.

[0055] ·Although at least a part of the shaft portion 31 of the mover 30 is made of a non-magnetic metal material, it may be changed to a non-magnetic resin material to form a non-magnetic portion. Also, the non-magnetic portion may be formed by post-processing a magnetic material into a non-magnetic material. Also, the non-magnetic portion may be formed as a void, such as by making a part or the whole of the shaft portion 31 of the mover 30 hollow.

[0056] ·The above combination of the number of magnetic poles of the stator 20, which is an armature, and the number of magnetic poles of the mover 30, which is a field magnet, is an example and may be changed as appropriate. When the number of pole pairs of the armature is "m" and the number of pole pairs of the field magnet is "n", a configuration in which "n = m ± 1", which is a Vernier motor, holds may be sufficient.

[0057] ·The radial relationship between the stator 20 and the rotor 30 may be configured in reverse, such that the stator 20 is on the radially inner side and the rotor 30 is on the radially outer side. ·Although the stator 20 is constituted by the armature and the rotor 30 is constituted by the field magnet, conversely, the stator 20 may be constituted by the field magnet and the rotor 30 may be constituted by the armature.

[0058] ·The expression "at least one" used in the present disclosure means "one or more" of the desired options. As an example, the expression "at least one" used in the present disclosure means "only one option" or "both of the two options" if the number of options is two.

Explanation of Reference Numerals

[0059] M1 to M3 Vernier motors, L1 shaft, 20 stator (armature), 21 magnetic pole portion (first magnetic pole portion), 22 coil, 23 magnetic plate (magnetic member), 30 rotor (field magnet), 31 shaft portion (rear side portion), 31a, 31b inner portion (rear side portion), 32 magnetic pole portion (second magnetic pole portion), 33, 33a to 33c permanent magnets, 34 magnetic portion

Claims

1. An armature (20) in which a plurality of first magnetic pole parts (21) of a pair of poles including a coil (22) and a magnetic member (23) are provided linearly, A field magnet (30) in which a plurality of second magnetic pole parts (32) of a pair of poles including permanent magnets (33, 33a to 33c) and a magnetic part (34) are provided linearly, and A linear Vernier motor (M1 to M3) configured to obtain a magnetic deceleration effect during magnetic transmission between the first and second magnetic pole parts based on energization of the coil, and obtaining a linear thrust in the axial direction (L1) by a relative linear movement of the armature and the field magnet, The field magnet is composed of a pole anisotropic magnet or a Halbach array magnet that allows magnetic flux to flow back and forth between the permanent magnet and the adjacent magnetic part, and at least a part of a first back side part (31a) located on the back side of the permanent magnet with respect to the armature and a second back side part (31b) located on the back side of the magnetic part with respect to the armature is composed of a non-magnetic part, The first back side part (31a) and the second back side part (31b) are separate members from each other, Vernier motor.

2. The armature is configured as an annular stator (20), The field magnet is configured as a mover (30) disposed inside the stator in the radial direction, The Vernier motor according to claim 1.

3. The field magnet includes a part where a first component (X1) including the permanent magnet and a second component (X2) including the magnetic part are stacked in the axial direction and is integrally configured, The Vernier motor according to claim 2.

4. The first and second components are configured to be accommodated in a cylindrical member (35), The Vernier motor according to claim 3.

5. The field magnet is configured such that the permanent magnet and the magnetic part are each annular, and the permanent magnet and the magnetic part are mounted on a long shaft part (31), The Vernier motor according to claim 2.

6. The field magnet is configured such that the permanent magnet is annular, and an inner part (31a) of the permanent magnet is configured as the non-magnetic part, The Vernier motor according to claim 2.

7. The field magnet is configured such that the magnetic part is annular, and an inner part (31b) of the magnetic part is configured as the non-magnetic part, The Vernier motor according to claim 2.

8. The field magnet has an annular shape for both the permanent magnet and the magnetic part, and inner parts (31a, 31b) of both the permanent magnet and the magnetic part are configured as the non-magnetic part. The Vernier motor according to claim 2.

9. The field magnet has a shaft part (31a) extending in the axial direction, and long members (36a, 36b) extending over the entire axial direction are arranged in the shaft part. The Vernier motor according to claim 2.

10. The long member is made of a non-magnetic material. The Vernier motor according to claim 9.

11. The long member is made of a magnetic material. The Vernier motor according to claim 9.

12. The field magnet is configured to have a slit (34a) or a rib extending in the axial direction on the opposing surface of the magnetic part on the armature side. The Vernier motor according to claim 2.

13. The armature is configured to have a slit (23a) or a rib extending in the axial direction on the opposing surface of the magnetic member on the field magnet side. The Vernier motor according to claim 2.

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