JP2002272150A - Magnetostrictive vibration motor and stator thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetostrictive vibration motor with high efficiency. SOLUTION: This magnetostrictive vibration motor includes a stator 1, and a rotor 2 which is brought into pressure contact with the end of the stator 1 in the axial direction and rotates, based on the vibration. The stator 1 includes a magnetostrictive element 8 which generates vibration by a change in magnetic field, a field coil 9 which is mounted so as to surround the outer periphery of the magnetostrictive element 8 and develops alternating field, based on alternating current, a permanent magnet 10 which is mounted so as to surround the outer periphery of the field coil 9 and develops bias field in one direction, and lower and upper yokes 6, 7, which clamps the magnetostrictive element 8, the field coil 9, and the permanent magnet 10 in the axial direction, and constitutes a magnetic path together with the field coil 9 and the permanent magnet 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetostrictive vibration motor using a magnetostrictive element and its stator.

[0002]

2. Description of the Related Art In recent years, various actuators using magnetostrictive elements (giant magnetostrictive elements) which generate distortion (expansion and contraction) when a magnetic field is changed have been proposed. As for a vibration type motor in which a rotor is rotated by vibration, a magnetostrictive vibration motor utilizing vibration caused by expansion and contraction of a magnetostrictive element has been proposed.

[0003]

However, the proposed magnetostrictive vibration motor is a proposal in which a magnetostrictive element is used instead of a piezoelectric element, and in particular, means and arrangement for changing a magnetic field are considered. And high efficiency has not been achieved.

An object of the present invention is to provide a highly efficient magnetostrictive vibration motor and its stator.

[0005]

According to a first aspect of the present invention, there is provided a magnetostrictive element which generates vibration by a change in a magnetic field based on an alternating current, and a yoke which sandwiches the magnetostrictive element and forms a magnetic path. A magnetostrictive vibration motor, comprising: a stator having a stator having a rotor that is pressed against the stator and rotates based on the vibration.

According to a second aspect of the present invention, there is provided a magnetostrictive element for generating vibration due to a change in a magnetic field, a magnetic field coil provided to surround an outer periphery of the magnetostrictive element and generating an alternating magnetic field based on an alternating current, A bias magnetic field generating means provided so as to surround an outer periphery of the magnetic field coil and generating a bias magnetic field in one direction; and a magnetic path together with the magnetic field coil and the bias magnetic field generating means for holding at least the magnetostrictive element in its axial direction. A magnetostrictive vibration motor, comprising: a stator having a yoke constituting: and a rotor pressed into contact with the axial end of the stator and rotating based on the vibration.

According to a third aspect of the present invention, in the magnetostrictive vibration motor according to the second aspect, a magnetostrictive element through-hole and a yoke through-hole are formed through the magnetostrictive element and the yoke of the stator in an axial direction. The magnetostrictive element and the yoke were fastened with a fastening member that penetrated the two through holes, and a pressure was applied to the magnetostrictive element via the two yokes.

According to a fourth aspect of the present invention, in the magnetostrictive vibration motor according to the third aspect, the fastening member is formed of a metal block having a horn portion for increasing the amplitude of vibration of a contact surface of the rotor. And the two yokes were fastened through.

The invention according to claim 5 is the invention according to claim 3 or 4.
In the magnetostrictive vibration motor described in (1), the fastening member fastens the two yokes via a vibration conversion block in which a slit that generates torsional vibration based on longitudinal vibration is formed.

[0010] The invention according to claim 6 is the invention according to claims 3 to 5
In the magnetostrictive vibration motor according to any one of the above, a slit that generates torsional vibration based on the vibration of the stator is formed in the rotor.

According to a seventh aspect of the present invention, there are provided two groups of magnetostrictive elements which are arranged in the circumferential direction and generate vibration by a change in magnetic field, and are provided so as to surround each of the magnetostrictive elements avoiding the radial direction. A magnetic field coil that generates an alternating magnetic field based on an alternating current, a bias magnetic field generating unit that is provided so as to surround the magnetic field coils avoiding the radial direction, and generates a bias magnetic field in one direction, and at least the magnetostrictive element. A yoke which is held in the radial direction and forms a magnetic path together with the magnetic field coil and the bias magnetic field generating means; and two groups of the magnetic field coils corresponding to the two groups of the magnetostrictive elements have a phase of 90 degrees. A stator that supplies different alternating currents and generates traveling wave vibration in the magnetostrictive element;
A magnetostrictive vibration motor comprising: a rotor that is pressed against the stator in a radial direction and rotates based on the traveling wave vibration.

According to an eighth aspect of the present invention, in the magnetostrictive vibration motor according to the seventh aspect, the diameter of the inner peripheral surface of the yoke disposed radially inside the magnetostrictive element is linear in the axial direction. Forming an inner peripheral taper surface that changes to an outer peripheral surface of the rotor, forming an outer peripheral taper surface capable of making surface contact with the inner peripheral taper surface, and pressing the rotor in the axial direction to form an outer taper surface thereof. The inner peripheral taper surface was brought into surface contact and pressure contact.

The invention according to claim 9 is the invention according to claim 7 or 8.
In the magnetostrictive vibration motor described in (1), the yoke arranged radially outside the magnetostrictive element forms a substantially cylindrical housing.

According to a tenth aspect of the present invention, in the magnetostrictive vibration motor according to the ninth aspect, the yoke disposed radially outside the magnetostrictive element is formed in a substantially bottomed cylindrical shape having a bottom, A detent engaging portion is formed on the bottom portion to be circumferentially engaged with the yoke disposed radially inside the magnetostrictive element.

According to an eleventh aspect of the present invention, in the magnetostrictive vibration motor according to any one of the second to tenth aspects,
The bias magnetic field generating means is a permanent magnet. According to a twelfth aspect of the present invention, there is provided a magnetostrictive element that generates vibration by a change in a magnetic field based on an alternating current, and a yoke that sandwiches the magnetostrictive element and forms a magnetic path, and rotates based on the vibration. The rotor is pressed against the stator.

According to a thirteenth aspect of the present invention, there is provided a magnetostrictive element for generating vibration due to a change in a magnetic field, a magnetic field coil provided to surround an outer periphery of the magnetostrictive element and generating an alternating magnetic field based on an alternating current, A bias magnetic field generating means provided so as to surround an outer periphery of the magnetic field coil and generating a bias magnetic field in one direction; and a magnetic path together with the magnetic field coil and the bias magnetic field generating means for holding at least the magnetostrictive element in its axial direction. And a rotor that rotates based on the vibration is pressed against an axial end.

According to a fourteenth aspect of the present invention, there are provided two groups of magnetostrictive elements which are arranged in the circumferential direction and generate vibration by a change in magnetic field, and are provided so as to surround each of the magnetostrictive elements avoiding the radial direction. A magnetic field coil that generates an alternating magnetic field based on an alternating current, a bias magnetic field generating unit that is provided so as to surround the magnetic field coils avoiding the radial direction, and generates a bias magnetic field in one direction, and at least the magnetostrictive element. A yoke which is held in the radial direction and forms a magnetic path together with the magnetic field coil and the bias magnetic field generating means.
A rotor that supplies alternating currents having a phase difference of 90 degrees to the two groups of magnetic field coils corresponding to the two groups of magnetostrictive elements, generates traveling wave vibrations in the magnetostrictive elements, and rotates based on the traveling wave vibrations Is a stator that is pressed and contacted in the radial direction.

(Operation) According to the first aspect of the present invention,
Vibration is generated in the magnetostrictive element by a change in the magnetic field based on the alternating current. Then, the rotor is driven to rotate based on the vibration. The magnetostrictive element is held by the yoke, and a magnetic path is formed by the yoke, so that generation of leakage magnetic flux is suppressed. Therefore, the output with respect to the supplied alternating current can be increased, and higher efficiency can be achieved.

According to the second aspect of the present invention, a bias magnetic field is generated in one direction by the bias magnetic field generating means, and an alternating magnetic field is generated by the magnetic field coil based on the alternating current. Then, vibration is generated in the magnetostrictive element due to a change in the magnetic field. Then, the rotor is driven to rotate based on the vibration. Then, at least the magnetostrictive element is held by the yoke and a magnetic path is formed by the yoke, so that generation of leakage magnetic flux is suppressed. Therefore, the output with respect to the supplied alternating current can be increased, and higher efficiency can be achieved.

According to the third aspect of the present invention, the magnetostrictive element and the yoke of the stator are formed with a magnetostrictive element through-hole and a yoke through-hole penetrating in the axial direction, and penetrate through both the through-holes. The magnetostrictive element and the yoke are fastened by a fastening member, and a pressure is applied to the magnetostrictive element via the yokes. Thus, by applying a pressure to the magnetostrictive element, the amplitude of the vibration can be increased, and the rotor can be more efficiently rotated. Moreover, since the fastening member is provided through the magnetostrictive element and the yoke as described above, the size can be reduced as compared with the case where the fastening member is provided outside the magnetostrictive element and the yoke.

According to the fourth aspect of the present invention, the two yokes are fastened by the fastening member via a metal block having a horn portion for increasing the amplitude of vibration of the contact surface of the rotor. Is done. Therefore, the amplitude of the vibration generated on the contact surface of the rotor at the horn can be increased, and the rotor can be more efficiently rotated.

According to the fifth aspect of the present invention, the two yokes are fastened by the fastening member via the vibration conversion block in which a slit for generating torsional vibration based on longitudinal vibration is formed. Therefore, the torsional vibration is efficiently generated in the slit based on the vibration generated by the magnetostrictive element, and the rotor can be more efficiently rotated.

According to the invention described in claim 6, the rotor is provided with a slit for generating torsional vibration based on the vibration of the stator. Therefore, the rotor itself can be efficiently rotated by the torsional vibration generated by the rotor itself.

According to the present invention, a bias magnetic field in one direction is generated by each bias magnetic field generating means,
An alternating magnetic field is generated in each magnetic field coil based on the alternating current. Then, a vibration is generated in each magnetostrictive element due to a change in the magnetic field. At this time, alternating currents having phases different from each other by 90 degrees are supplied to the two groups of the magnetic field coils corresponding to the two groups of the magnetostrictive elements, and the traveling waves are generated in the magnetostrictive elements. Then, the rotor is rotationally driven based on the traveling wave vibration. Then, at least the magnetostrictive element is held by the yoke and a magnetic path is formed by the yoke, so that generation of leakage magnetic flux is suppressed. Therefore, the output with respect to the supplied alternating current can be increased, and higher efficiency can be achieved.

According to the eighth aspect of the present invention, the inner peripheral surface of the yoke arranged radially inside the magnetostrictive element has an inner peripheral taper surface whose diameter linearly changes in the axial direction. The outer peripheral surface of the rotor is formed with an outer peripheral taper surface capable of making surface contact with the inner peripheral taper surface, and the rotor is pressurized in the axial direction, and the outer peripheral taper surface is formed on the inner peripheral taper surface. Surface contact and pressure contact are made. This makes it possible to easily bring the rotor into pressure contact with the stator in the radial direction. In addition, since the outer peripheral taper surface is pressed against the inner peripheral taper surface to maintain the axial center position, a bearing for supporting the rotating shaft of the rotor is not required.

According to the ninth aspect of the present invention, since the yoke disposed radially outside the magnetostrictive element also serves as a substantially cylindrical housing, the yoke and the housing are formed as separate members. The manufacturing cost is reduced as compared with that of the conventional method.

According to the tenth aspect of the present invention, the yoke disposed radially outward of the magnetostrictive element is formed in a substantially bottomed cylindrical shape having a bottom, and the bottom has a diameter of the magnetostrictive element. A detent engaging portion which is circumferentially engaged with the yoke arranged on the inner side in the direction is formed. Therefore, a separate member for preventing rotation of the yoke disposed radially inside the magnetostrictive element is not required.

According to the magnetostrictive vibration motor of the eleventh aspect, since the bias magnetic field generation means is a permanent magnet, it can generate a unidirectional bias magnetic field with a simple configuration. According to the twelfth aspect, vibration is generated in the magnetostrictive element by a change in the magnetic field based on the alternating current. Then, the rotor is driven to rotate based on the vibration. The magnetostrictive element is held by the yoke, and a magnetic path is formed by the yoke, so that generation of leakage magnetic flux is suppressed. Therefore, the output with respect to the supplied alternating current can be increased, and higher efficiency can be achieved.

According to the thirteenth aspect, the bias magnetic field generating means generates a one-way bias magnetic field,
An alternating magnetic field is generated in the magnetic field coil based on the alternating current. Then, vibration is generated in the magnetostrictive element due to a change in the magnetic field. Then, the rotor is driven to rotate based on the vibration. Then, at least the magnetostrictive element is held by the yoke and a magnetic path is formed by the yoke, so that generation of leakage magnetic flux is suppressed. Therefore, the output with respect to the supplied alternating current can be increased, and higher efficiency can be achieved.

According to the present invention, a bias magnetic field in one direction is generated by each bias magnetic field generating means, and an alternating magnetic field is generated in each magnetic field coil based on the alternating current. Then, a vibration is generated in each magnetostrictive element due to a change in the magnetic field. At this time, the two groups of magnetic field coils corresponding to the two groups of magnetostrictive elements have 9
An alternating current having a phase difference of 0 degrees is supplied, and a traveling wave oscillation is generated in the magnetostrictive element. Then, the rotor is rotationally driven based on the traveling wave vibration. Then, at least the magnetostrictive element is held by the yoke and a magnetic path is formed by the yoke, so that generation of leakage magnetic flux is suppressed. Therefore, the output with respect to the supplied alternating current can be increased, and higher efficiency can be achieved.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A first embodiment in which the present invention is embodied in a standing wave type magnetostrictive vibration motor will be described below with reference to FIG.

As shown in FIG. 1, the magnetostrictive vibration motor includes a stator 1, a rotor 2, and a housing H. The stator 1 includes a lower metal block 3, an upper metal block 4,
It includes a vibration conversion block 5, a lower yoke 6, an upper yoke 7, a giant magnetostrictive element 8 as a magnetostrictive element, a magnetic field coil 9, a permanent magnet 10 as a bias magnetic field generating means, a bolt 11, and a nut 12. In the present embodiment, the bolt 11 and the nut 12 constitute a fastening member.

The lower and upper metal blocks 3, 4 and the vibration conversion block 5 are formed of an aluminum alloy.
The lower metal block 3 is formed in a substantially cylindrical shape, and a concave portion 3a having a diameter larger than that of the central hole is formed in the center of the lower end side. Further, a plurality of fixing concave portions 3 b formed inward in the radial direction are formed in the circumferential direction on the upper end side of the outer peripheral surface of the lower metal block 3.

The upper metal block 4 has an outer diameter smaller than the outer diameter of the lower metal block 3 and an inner diameter smaller than the lower metal block 3.
And a concave portion 4a having a diameter larger than that of the central hole is formed in the center of the upper end side. By forming the concave portion 4a, the upper portion whose inner diameter is increased constitutes a horn portion 4b for increasing the amplitude of vibration of its upper end surface (rotor contact surface).

The vibration conversion block 5 is formed in a substantially cylindrical shape whose inner and outer diameters are the same as the inner and outer diameters of the lower metal block 3, and has on its outer peripheral surface a plurality of slanted inclined to generate torsional vibrations based on longitudinal vibrations. A slit (recess) 5a is formed.
At the lower end of the outer peripheral surface of the vibration conversion block 5, a fixing recess 5 b that is recessed radially inward is formed at a position corresponding to each fixing recess 3 b of the lower metal block 3.

The lower and upper yokes 6, 7 are made of a magnetic metal material (steel plate). The lower and upper yokes 6 and 7 are formed in a substantially disk shape whose inner and outer diameters are the same as the inner and outer diameters of the lower metal block 3. The center holes of the lower and upper yokes 6, 7 constitute yoke through holes 6a, 7a.

The giant magnetostrictive element 8 is formed in a substantially cylindrical shape whose inner and outer diameters are the same as the inner and outer diameters of the upper metal block 4. The central hole of the giant magnetostrictive element 8 forms a magnetostrictive element through hole 8a. The giant magnetostrictive element 8 is an element that generates distortion (expansion and contraction movement) due to a change in the magnetic field, and generates vibration by repeating the change in the magnetic field.

The outer diameter of the magnetic field coil 9 is smaller than the outer diameter of the lower metal block 3 (the lower and upper yokes 6, 7), and the inner diameter is formed to be substantially the same as the outer diameter of the giant magnetostrictive element 8. The magnetic field coil 9 is provided so as to surround the outer periphery of the giant magnetostrictive element 8. The winding end of the magnetic field coil 9 is connected to an external control device (not shown). And
The magnetic field coil 9 generates an alternating magnetic field based on an alternating current supplied from the control device.

The permanent magnet 10 is formed in a substantially cylindrical shape whose outer diameter is the same as the outer diameter of the lower metal block 3 (lower and upper yokes 6, 7) and whose inner diameter is substantially the same as the outer diameter of the magnetic field coil 9. Have been. The permanent magnet 10 is provided so as to surround the outer periphery of the magnetic field coil 9. This permanent magnet 10 is polarized in the axial direction. In the present embodiment, the lower end of the permanent magnet 10 in the axial direction is set to the N pole, and the upper end of the permanent magnet 10 is set to the S pole.

The lower metal block 3, the vibration conversion block 5, the lower yoke 6, the giant magnetostrictive element 8, the upper yoke 7, and the upper metal block 4 are stacked in this order, and each central hole (yoke through hole 6a) is formed. , 7a and the magnetostrictive element through-hole 8a), and the nut 12 is fastened by being screwed into a bolt 11. At this time, the magnetic field coil 9 and the permanent magnet 10 are arranged so as to surround the outer periphery of the giant magnetostrictive element 8 as described above, and are held between the lower and upper yokes 6 and 7. At this time, a pressurizing force is applied to the giant magnetostrictive element 8 via the lower and upper yokes 6 and 7 to increase the amplitude of its own vibration. In the present embodiment,
Each member 3 to 12 (stator 1) is housed in a housing H. The fixing recess 3b of the housing H,
A fixing projection Ha is formed at a position corresponding to 5b.
The stator 1 is supported in the housing H by fitting the fixing projections Ha and the fixing recesses 3b, 5b.

The outer diameter of the rotor 2 is substantially the same as the outer diameter of the upper metal block 4. An output shaft 2a projecting upward is integrally formed with the rotor 2. A plurality of inclined slits (recesses) 2b that generate torsional vibration based on vibration are formed on the outer peripheral surface of the rotor 2.

Then, the rotor 2 is driven by the disc spring 13
The lower surface is slidably and rotatably pressed against the upper surface of the stator 1, that is, the upper surface of the upper metal block 4. Specifically, the rotor 2 is supported by a bearing 14 fixed to an upper part of the housing H so as to be rotatable and movable in the axial direction so that only the distal end side of the output shaft 2a projects outside the housing H. I have. One end (upper end) of the rotor 2 is urged downward by the other end (lower end) of the disc spring 13 supported by the housing H, and the lower surface thereof comes into pressure contact with the upper surface of the upper metal block 4 (stator 1). Have been.

Here, in the magnetostrictive vibration motor, the vibration conversion block 5 (slit 5a) of the stator 1 is caused by resonance.
Generates a torsional vibration, the rotor 2 (slit 2b) generates substantially no torsional vibration, the first frequency (stator-main mode), and the vibration conversion block 5 (slit 5a) generates almost no torsional vibration. The second frequency (rotor-main mode) at which the slit 2b) generates torsional vibration is set. At the first frequency (stator-main mode), the rotor 2 is driven to rotate forward by the propulsive force of the torsional vibration component generated by the stator 1, and at the second frequency (rotor-main mode), the torsional vibration component generated by the rotor 2 is generated. (The shape of the slits 2b and 5a, etc.) are set so that the rotor (the rotor 2) is driven to rotate in the reverse direction by the propulsive force of the motor.

In the magnetostrictive vibration motor configured as described above, the first frequency (stator-main mode) is applied to the magnetic field coil 9.
Is supplied, an alternating magnetic field is generated based on the alternating current. Then, the unidirectional bias magnetic field generated by the permanent magnet 10 and a change in the magnetic field based on the alternating magnetic field cause a longitudinal vibration of the first frequency in the giant magnetostrictive element 8. Then, the vibration conversion block 5 (slit 5a) generates torsional vibration by resonating with the longitudinal vibration, and the rotor 2 is driven to rotate forward by the propulsive force of the torsional vibration component.

When an alternating current corresponding to the second frequency (rotor-main mode) is supplied to the magnetic field coil 9, an alternating magnetic field is generated based on the alternating current. Then, a longitudinal vibration of the second frequency is generated in the giant magnetostrictive element 8 by a change in a magnetic field based on the one-way bias magnetic field generated by the permanent magnet 10 and the alternating magnetic field. Then, the rotor 2 (slit 2b) resonates with the longitudinal vibration to generate torsional vibration, and the rotor 2 is driven to rotate in the reverse direction by the propulsive force of the torsional vibration component.

Next, the characteristic operation and effect of the first embodiment will be described below. (1) The giant magnetostrictive element 8 is sandwiched between the lower and upper yokes 6, 7, and a magnetic path is formed by the lower and upper yokes 6, 7 (magnetic field coil 9 and permanent magnet 10 → lower side). York 6
(The upper yoke 7) → the giant magnetostrictive element 8 → the upper yoke 7 (the lower yoke 6) → the magnetic field coil 9 and the permanent magnet 10), so that generation of leakage magnetic flux is suppressed. Therefore, the amount of effective magnetic flux with respect to the supplied AC current, and thus the output (amplitude of vibration)
Can be increased, and high efficiency can be achieved.

(2) Since a unidirectional bias magnetic field is generated in the permanent magnet 10, the size of the magnetic field coil 9 is reduced and the value of the alternating current to be supplied is reduced while the giant magnetostrictive element 8 is sufficiently elongated. A large magnetic field in one direction can be generated. Therefore, higher efficiency can be achieved.

(3) The lower and upper yokes 6, 7 and the giant magnetostrictive element 8 are provided with yoke through holes 6a, 7a penetrating in the axial direction.
In addition, a magnetostrictive element through hole 8a is formed. The lower and upper yokes 6, 7 and the giant magnetostrictive element 8 are fastened by screwing a nut 12 to a bolt 11 passing through both through holes 6a to 8a, and the lower and upper yokes 6 , 7
Is applied to the giant magnetostrictive element 8 via. Thus, by applying a pressure to the giant magnetostrictive element 8, the amplitude of the vibration can be increased, and the rotor 2 can be rotated more efficiently. In addition, the bolts 11 constituting the fastening member are connected to the lower and upper yokes 6 and 7 and the giant magnetostrictive element 8.
, The size of the magnetostrictive vibration motor (stator 1) can be reduced as compared with the case where the fastening members are provided outside the lower and upper yokes 6, 7 and the giant magnetostrictive element 8.

(4) The upper metal block 4 is provided with a horn 4b for increasing the amplitude of vibration of its upper end surface (rotor contact surface). Then, the upper and lower yokes 6 and 7 are fastened by the bolts 11 and the nuts 12 via the upper metal block 4. Therefore, the amplitude of the vibration generated on the contact surface of the rotor 2 at the horn portion 4b can be increased, and the rotor 2 can be more efficiently rotated.

(5) On the outer peripheral surface of the vibration conversion block 5,
A plurality of inclined slits (recesses) 5a that generate torsional vibrations based on longitudinal vibrations (vibrations in the stator main mode) are formed. Then, the upper and lower yokes 6 and 7 are fastened by the bolt 11 and the nut 12 via the vibration conversion block 5. Therefore, the torsional vibration is efficiently generated in the slit 5a based on the vibration generated by the giant magnetostrictive element 8, and the rotor 2 can be more efficiently rotated.

(6) On the outer peripheral surface of the rotor 2, there is formed a slit 2b for generating torsional vibration based on vibration (vibration in the rotor main mode). Therefore, the rotor 2 itself can be efficiently rotated by the torsional vibration generated by the rotor 2 itself.

(7) Since the giant magnetostrictive element 8 having a large displacement is used as the magnetostrictive element, the amplitude of vibration can be increased, and the rotor 2 can be more efficiently rotated. (8) Since the permanent magnet 10 is used as a bias magnetic field generating means for generating a unidirectional bias magnetic field, a unidirectional bias magnetic field can be generated with a simple configuration.

(Second Embodiment) A second embodiment in which the present invention is embodied in a traveling wave type magnetostrictive vibration motor will be described below with reference to FIG.

As shown in FIG. 2, the magnetostrictive vibration motor has a stator 20 and a rotor 21. Stator 20
The outer yoke 22, the inner yoke 23, the upper connecting yoke 24, a plurality of giant magnetostrictive elements 25a as magnetostrictive elements,
25b, a plurality of magnetic field coils 26a and 26b, and a plurality of permanent magnets 27 as bias magnetic field generating means.

The outer yoke 22 is formed of a magnetic metal material (steel plate). The outer peripheral side yoke 22 is formed in a substantially cylindrical shape having a bottom and a bottom, and includes a substantially cylindrical outer peripheral cylindrical portion 22a and a disk-shaped bottom portion 22b. The outer yoke 22 also serves as a housing for the magnetostrictive vibration motor. An annular convex portion 22c is formed on the bottom portion 22b of the outer peripheral side yoke 22 so as to protrude upward in an annular shape.
In the upper part of c, an engagement concave portion 22d is formed as an engagement portion that is formed by a plurality of concave portions in the circumferential direction.

The inner peripheral yoke 23 is connected to the outer cylindrical portion 22a.
It is formed in a substantially cylindrical shape with a smaller diameter. The inner peripheral surface of the inner peripheral yoke 23 is an inner peripheral tapered surface 23a whose diameter changes linearly in the axial direction. The inner peripheral tapered surface 23a of the present embodiment is reduced in diameter toward the lower end. The inner and outer diameters at the lower end of the inner peripheral yoke 23 are set to be substantially the same as the inner and outer diameters of the annular convex portion 22c. At the lower end of the inner peripheral yoke 23, an engagement protrusion 23b that can be fitted into the engagement recess 22d is formed at a position corresponding to the engagement recess 22d.

The inner yoke 23 is housed inside the outer cylindrical portion 22a, and the engagement protrusion 2
3b is fitted and arranged in the engaging recess 22d. At this time, the inner peripheral side yoke 23 is prevented from rotating with respect to the outer peripheral side yoke 22 by engaging the engaging convex portion 23b with the engaging concave portion 22d in the circumferential direction.

The upper connecting yoke 24 has a substantially cylindrical tubular portion 24a and an annular disk portion 24b extending radially outward from the upper end of the tubular portion 24a. The outer diameter of the cylindrical portion 24a is set to be the same as the outer diameter of the annular convex portion 22c. The outer diameter of the disk portion 24b is set to be substantially the same as the inner diameter of the outer cylindrical portion 22a.

The upper connecting yoke 24 is housed inside the outer peripheral cylindrical portion 22a, and
The lower end of “a” is disposed in contact with the upper end of the inner peripheral yoke 23. As a result, a substantially cylindrical housing portion (space) 28 surrounded by the outer yoke 22, the inner yoke 23, and the upper connecting yoke 24 is formed.

A plurality of giant magnetostrictive elements 25a and 25b are provided in
(Only two are shown in FIG. 2). The giant magnetostrictive elements 25a and 25b
Is formed in an arc-shaped cross section along the circle of
a, and is pressurized by the outer peripheral surface of the inner peripheral side yoke 23. More specifically, the giant magnetostrictive elements 25a and 25b of the present embodiment are in a state of being in contact with the inner circumferential surface of the outer cylindrical portion 22a and the inner circumferential yoke 23 is press-fitted inside the outer cylindrical portion 22a. And the outer peripheral surface of the inner peripheral side yoke 23, and pressurization is applied. The plurality of giant magnetostrictive elements 25a and 25b are classified into two groups, that is, a first group including two giant magnetostrictive elements 25a and a second group including two giant magnetostrictive elements 25b. Then, the two giant magnetostrictive elements 25a of the first group are arranged close to each other in the circumferential direction.
Further, the two giant magnetostrictive elements 25b of the second group are arranged close to each other in the circumferential direction. And 2 of the first group
The two groups of giant magnetostrictive elements 25a and the two groups of two giant magnetostrictive elements 25b are arranged at predetermined intervals in the circumferential direction to generate traveling wave vibration.

The magnetic field coils 26a and 26b are provided in the housing 28 so as to avoid the radial
a, 25b. The plurality of magnetic field coils 26a and 26b include two groups, that is, a first group including the magnetic field coils 26a corresponding to the two giant magnetostrictive elements 25a and a magnetic field coil 26b corresponding to the two giant magnetostrictive elements 25b. It is classified into the second group. The two magnetic field coils 26a of the first group are wound around the giant magnetostrictive element 25a of the first group so that the winding directions are different. This first
The winding ends of the two magnetic field coils 26a of the group are connected to a first terminal of an external control device (not shown). The two magnetic field coils 26b of the second group are wound around the giant magnetostrictive element 25b of the second group so that the winding directions are different. The winding ends of the two magnetic field coils 26b of the second group are connected to a second terminal of an external control device (not shown). Then, each magnetic field coil 26a, 2
6b generates an alternating magnetic field based on the alternating current supplied from the control device.

The permanent magnet 27 is provided in the housing portion 28 so as to surround the magnetic field coils 26a and 26b, avoiding the radial direction. The permanent magnet 27 is polarized in the radial direction of the stator 20 (the outer cylindrical portion 22a). Incidentally, the permanent magnet 27 of the present embodiment is
Of the stator 20 is set to the N pole, and the radial outside of the stator 20 is set to the S pole.

The rotor 21 is formed in a substantially cylindrical shape, and the outer peripheral surface thereof is formed with an outer peripheral tapered surface 21a that can make surface contact with the inner peripheral tapered surface 23a, that is, the outer peripheral tapered surface 21a whose diameter is reduced toward the lower end side. Have been. This rotor 21 has
An output shaft 21b protruding upward is integrally formed.

The outer peripheral tapered surface 21a of the rotor 21 is brought into surface contact and pressure contact with the inner peripheral tapered surface 23a by a disc spring 29. Specifically, a cover 3 that covers the upper end of the outer yoke 22 substantially covers the opening.
0 is fitted. The rotor 21 is substantially housed in the outer cylindrical portion 22a such that only the distal end side of the output shaft 21b passes through a through hole 30a formed in the cover 30 and projects outside. The rotor 21 is urged downward at the other end (lower end) of the disc spring 29 whose one end (upper end) is supported by the cover 30, and its outer tapered surface 21a comes into surface contact with the inner tapered surface 23a. It is in pressure contact.

In the magnetostrictive vibration motor configured as described above, the two magnetic field coils 26 of the first group are
a and the two magnetic field coils 26b of the second group
When alternating currents with different degrees (shifted) are supplied,
In each of the magnetic field coils 26a and 26b, an alternating magnetic field is generated based on the alternating current. Then, a traveling wave vibration is generated on the inner peripheral taper surface 23a in each of the giant magnetostrictive elements 25a and 25b due to a one-way bias magnetic field generated by the permanent magnet 27 and a change in the magnetic field based on the alternating magnetic field. . Then, the rotor 21 is rotationally driven based on the traveling wave vibration.

Next, the characteristic operation and effect of the second embodiment will be described below. (1) The giant magnetostrictive elements 25a and 25b
The outer peripheral yoke 22, the inner peripheral yoke 23 and the upper connecting yoke 24 constitute a magnetic path (the magnetic field coil 26).
a, 26b and permanent magnet 27 → at least one of yokes 22 to 24 → giant magnetostrictive element 8 → at least one of yokes 22 to 24 → magnetic field coil 9 and permanent magnet 10)
Generation of leakage magnetic flux is suppressed. Therefore, the amount of effective magnetic flux with respect to the supplied alternating current, and the output (amplitude of vibration) can be increased, and high efficiency can be achieved.

(2) Since a unidirectional bias magnetic field is generated by the permanent magnet 27, the giant magnetostrictive elements 25a and 25b can be mounted while reducing the size of the magnetic field coils 26a and 26b and the value of the supplied AC current. A large magnetic field in one direction that can be sufficiently extended can be generated. Therefore,
Further, higher efficiency can be achieved.

(3) The giant magnetostrictive elements 25a and 25b are held by the inner peripheral surface of the outer cylindrical portion 22a and the outer peripheral surface of the inner yoke 23, and are pressurized. By applying a preload to the giant magnetostrictive elements 25a and 25b in this manner, the amplitude of vibration can be increased, and the rotor 21 can be rotated more efficiently. Moreover, the giant magnetostrictive elements 25a, 25
b is an inner peripheral surface of the outer cylindrical portion 22a and an outer peripheral surface of the inner peripheral yoke 23 when the inner peripheral yoke 23 is pressed into the inner peripheral surface of the outer cylindrical portion 22a in a state of being in contact with the inner peripheral surface of the outer cylindrical portion 22a. Thus, the magnetostrictive vibration motor (stator 20) does not require a separate member for applying the pressurization. Therefore, the number of parts is reduced as compared with the case where a separate member for applying the pressurization is required, and the manufacturing cost can be reduced.

(4) The inner peripheral surface of the inner peripheral side yoke 23 is an inner peripheral taper surface 23a whose diameter changes linearly in the axial direction. The outer peripheral surface of the rotor 21 has the inner peripheral taper surface 23a.
The outer peripheral taper surface 21a which can make surface contact with a is formed. The rotor 21 has one end (upper end) side of the cover 3.
The lower end of the disc spring 29 supported at 0 is urged downward so that the outer peripheral tapered surface 21a is in surface contact and pressure contact with the inner peripheral tapered surface 23a. By doing so, the rotor 21 (outer peripheral tapered surface 21a) is
0 can easily be brought into radial contact with the rotor contact surface (the inner peripheral tapered surface 23a). Moreover, the rotor 21
Since the outer peripheral taper surface 21a is pressed against the inner peripheral taper surface 23a to maintain the axial center position, the magnetostrictive vibration motor does not require a bearing for supporting the output shaft 21b of the rotor 21. As a result, the manufacturing cost of the magnetostrictive vibration motor can be reduced.

(5) Since the outer peripheral yoke 22 also serves as the housing of the magnetostrictive vibration motor, the outer yoke 22 and the housing are different from those in which the outer yoke 22 and the housing are formed as separate members.
The manufacturing cost can be reduced.

(6) The outer yoke 22 includes an outer cylindrical portion 22a having a substantially cylindrical shape and a bottom portion 22b having a disk shape.
An annular convex portion 22c is formed on the bottom portion 22b so as to protrude annularly upward. The upper portion of the annular convex portion 22c is circumferentially engaged with the inner peripheral yoke 23 (the engaging convex portion 23b). An engagement recess 22d is formed. Therefore, this magnetostrictive vibration motor (stator 20) does not require a separate member for preventing the inner peripheral yoke 23 from rotating. as a result,
The manufacturing cost of the magnetostrictive vibration motor (stator 20) can be reduced.

(7) Since the giant magnetostrictive elements 25a and 25b having a large displacement are used as the magnetostrictive elements, the amplitude of vibration can be increased and the rotor 21 can be rotated more efficiently.

(8) Since the permanent magnet 27 is used as a bias magnetic field generating means for generating a bias magnetic field in one direction,
A bias magnetic field in one direction can be generated with a simple configuration.

The above embodiments may be modified as follows. In the above embodiments, the permanent magnets 10 and 27 for generating a unidirectional bias magnetic field are provided.
27 may be omitted. Even in this case, effects similar to the effects (1), (3) to (7) of the above embodiments can be obtained.

In the first embodiment, the lower and upper yokes 6, 7 and the yoke through holes 6a, 7 of the giant magnetostrictive element 8 are provided.
a and a nut 12 is screwed into a bolt 11 passing through the through hole 8a of the magnetostrictive element and the lower and upper yokes 6, 6.
7, fastening the giant magnetostrictive element 8 and
However, the lower and upper yokes 6 and 7 and the giant magnetostrictive element 8 may be fastened in another configuration to apply a pressurization to the giant magnetostrictive element 8. For example, the lower metal block 3 and the upper metal block 4 may be fastened by another fastening member that is fastened in the axial direction on the outside in the radial direction, and pressurization may be applied to the giant magnetostrictive element 8. Even in this case, effects similar to the effects (1), (2), (4) to (8) of the first embodiment can be obtained. In addition, by applying a pressure to the giant magnetostrictive element 8, the amplitude of the vibration can be increased, and the rotor 2 can be more efficiently rotated. Also, the giant magnetostrictive element 8
May be changed to a configuration in which no preload is applied. Even in this case, the effects (1), (2), and
The same effects as (4) to (8) can be obtained.

In the first embodiment, the horn portion 4b for increasing the amplitude of the vibration of the upper end surface (the rotor contact surface) of the upper metal block 4 is described. You may change to the upper metal block 4 in which the horn part 4b is not formed. Even in this case, the effects (1) to (3) and (5) to (8) of the first embodiment can be obtained.
The same effect as described above can be obtained.

In the first embodiment, the outer peripheral surface of the vibration conversion block 5 is inclined to generate torsional vibration for driving the rotor 2 to rotate forward based on the vibration (vibration in the stator main mode). A plurality of slits (recesses) 5a are formed, and a slit 2b that generates torsional vibration for reverse rotation driving of the rotor 2 based on vibration (vibration in the rotor main mode) is formed on the outer peripheral surface of the rotor 2. However, the configuration may be changed to one in which one of the slits 2b and 5a is not formed. Even in this case, it is possible to efficiently obtain a rotational force in one direction. Also, slits 2b, 5
The shape of a may be changed to a slit that generates torsional vibration for driving the rotor 2 to rotate forward at a common resonance frequency. In this case, it is necessary to supply an alternating current corresponding to the common resonance frequency to the magnetic field coil 9. This makes it possible to more efficiently obtain a rotational force in one direction.

In the first embodiment, the lower and upper yokes 6, 7 are formed in a substantially disk shape whose inner and outer diameters are the same as the inner and outer diameters of the lower metal block 3. Although the magnetic field coil 9 and the permanent magnet 10 are held, the outer diameter may be reduced so as to hold at least the giant magnetostrictive element 8. For example, the lower and upper yokes 6,
7 is set equal to the outer diameter of the magnetic field coil 9, and the axial length of the permanent magnet 10 is set to the giant magnetostrictive element 8 and the magnetic field coil 9.
From the lower end of the lower yoke to the upper end of the upper yoke. Even in this case, the same effect as that of the first embodiment can be obtained. Moreover,
Since the length of the permanent magnet in the axial direction is increased, the thickness of the permanent magnet in the radial direction can be reduced while obtaining the same bias magnetic field as in the first embodiment, and thus the size of the magnetostrictive vibration motor can be reduced. Can be planned. Further, for example, the outer diameters of the lower and upper yokes 6 and 7 are set to be the same as the outer diameters of the giant magnetostrictive elements 8, and the axial lengths of the magnetic field coil 9 and the permanent magnet 10 are narrowed by the giant magnetostrictive elements 8. The length is from the lower end of the lower yoke to the upper end of the upper yoke. Even if you do this,
The same effects as those of the first embodiment can be obtained. Moreover, since the length of the permanent magnet in the axial direction is increased, the thickness of the permanent magnet in the radial direction can be reduced while obtaining the same bias magnetic field as in the first embodiment. Can be achieved. Further, since the length of the magnetic field coil in the axial direction is increased, the thickness of the magnetic field coil in the radial direction can be reduced while obtaining an alternating magnetic field having the same amplitude as that of the first embodiment. The diameter of the motor can be further reduced.

In the above embodiments, the giant magnetostrictive elements 8, 25a, 25b having a large displacement are used as the magnetostrictive elements, but may be changed to the magnetostrictive elements having a small displacement. Even in this case, the effects (1) to (6) of the above embodiments,
The same effect as (8) can be obtained.

In the above embodiments, the permanent magnets 10 and 27 are used as the bias magnetic field generating means for generating the bias magnetic field in one direction. However, if the bias magnetic field in one direction can be generated, other bias magnetic fields can be generated. The means may be changed. For example, the permanent magnets 10 and 27 may be changed to bias magnetic field generating coils. In this case, it is necessary to supply a direct current to the bias magnetic field generating coil when driving the magnetostrictive vibration motor. Even in this case, effects similar to the effects (1), (3) to (7) of the above embodiments can be obtained. Since the bias magnetic field generating coil generates a bias magnetic field in one direction, the magnetic field coils 9 and 26
It is possible to generate a large magnetic field in one direction enough to sufficiently extend the giant magnetostrictive elements 8, 25a, 25b while reducing the size of the AC current to be supplied and reducing the size of the supplied AC current.

In the second embodiment, the inner peripheral yoke 23 is press-fitted inside the giant magnetostrictive elements 25a and 25b in a state where the giant magnetostrictive elements 25a and 25b are in contact with the inner peripheral surface of the outer cylindrical portion 22a. And pressurized by the inner peripheral surface of the outer cylindrical portion 22a and the outer peripheral surface of the inner peripheral yoke 23. However, the preload may be applied to the giant magnetostrictive elements 25a and 25b by another configuration. .
For example, the giant magnetostrictive elements 25a, 25b are housed in the housing part 28 in a state in which no preload is applied, and then the outer cylindrical part 22a is compressed radially inward to reduce the diameter thereof. Pressurization may be applied to 25b. Even in this case, the effects (1), (2), and
The same effects as (4) to (8) can be obtained. In addition, by applying a preload to the giant magnetostrictive elements 25a and 25b, the amplitude of the vibration can be increased, and the rotor 21 can be rotated more efficiently. Also, the giant magnetostrictive element 25
The configuration in which no preload is applied to a and 25b may be changed. Even in this case, the effect (1) of the second embodiment,
The same effects as (2) and (4) to (8) can be obtained.

In the second embodiment, the inner peripheral surface of the inner peripheral side yoke 23 is an inner peripheral taper surface 23a whose diameter linearly changes in the axial direction. Outer peripheral tapered surface 21a capable of surface contact with peripheral tapered surface 23a
Is formed, and the outer peripheral taper surface 21a is brought into surface contact and pressure contact with the inner peripheral taper surface 23a by urging the rotor 21 downward. However, if the rotor 21 can be pressed against the stator 20 in the radial direction, You may change to another structure. For example, the inner and outer tapered surfaces 23a and 21a are surfaces whose diameters do not change in the axial direction, and the rotor is pressed into the stator (inner yoke) at a predetermined pressure so as to be pressed in the same manner as the pressed contact. The configuration may be changed. Even in this case, the effects (1) to (3) of the second embodiment,
The same effects as (5) to (8) can be obtained. or,
Even in this case, since the rotor is kept at the axial center position, the magnetostrictive vibration motor does not require a bearing for supporting the output shaft of the rotor.

In the second embodiment, the rotor 21
Although the outer peripheral taper surface 21a is pressed against the inner peripheral taper surface 23a to maintain the axial center position,
A bearing may be provided in the through hole 30a of the cover 30, and the output shaft 21b of the rotor 21 may be supported by the bearing. This ensures that the axial center position of the rotor 21 is maintained.

In the second embodiment, the outer yoke 22 also serves as the housing of the magnetostrictive vibration motor. However, the housing of the magnetostrictive vibration motor may be constituted by another member. Even in this case, effects similar to the effects (1) to (4) and (6) to (8) of the second embodiment can be obtained.

In the second embodiment, the outer yoke 22 includes the outer cylindrical portion 22a having a substantially cylindrical shape and the bottom portion 22b having a disk shape.
3 (engaging convex portion 23b) and engaging concave portion 22 circumferentially engaged therewith
Although d is formed, the inner peripheral yoke 23 may be prevented from rotating by another member. Even in this case, the same effects as the effects (1) to (5) and (7) to (8) of the second embodiment can be obtained.

In the second embodiment, four giant magnetostrictive elements 25a and 25b, four magnetic coils 26a and 26b, and four permanent magnets 27 are provided (two groups of two magnets). It may be changed as appropriate. For example, giant magnetostrictive elements 25a and 25b, magnetic field coils 26a and 2
6b, a magnetostrictive vibration motor (stator 20) including eight permanent magnets 27 (two groups of four permanent magnets) may be used. Even in this case, the same effect as the effect of the second embodiment can be obtained.

The magnetostrictive vibration motor of each of the above embodiments is
A stator having a magnetostrictive element that generates vibration by a change in a magnetic field based on an alternating current, a yoke that sandwiches the magnetostrictive element and forms a magnetic path, and is pressed into contact with the stator and rotates based on the vibration. As long as the motor includes a rotor, the motor may be changed to another magnetostrictive vibration motor.

The technical ideas that can be grasped from the above embodiments will be described below together with their effects. (A) The magnetostrictive vibration motor according to any one of claims 1 to 11, wherein the magnetostrictive element is a giant magnetostrictive element. This way,
The amplitude of the vibration can be increased, and the rotor can be more efficiently rotated.

(B) The stator according to any one of claims 12 to 14, wherein the magnetostrictive element is a giant magnetostrictive element. By doing so, the amplitude of the vibration can be increased, and the rotor can be more efficiently rotated.

[0090]

As described in detail above, according to the first to eleventh aspects of the present invention, a highly efficient magnetostrictive vibration motor can be provided.

Further, according to the present invention, it is possible to provide a highly efficient magnetostrictive vibration motor stator.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a magnetostrictive vibration motor according to a first embodiment.

FIG. 2 is an essential part cross-sectional view of a magnetostrictive vibration motor according to a second embodiment.

[Explanation of symbols]

1, 20 ... stator, 2, 21 ... rotor, 4 ... upper metal block (metal block), 5 ... vibration conversion block,
6, 7 ... lower and upper yokes (yoke), 8, 25a,
25b: giant magnetostrictive element (magnetostrictive element), 9, 26a, 26b
... magnetic field coil, 10, 27 ... permanent magnet (bias magnetic field generating means), 11 ... bolt forming a fastening member, 12 ... nut forming a fastening member, 22 ... outer yoke (yoke), 23 ... inner circumference yoke (Yoke), 24: upper connecting yoke (yoke), 2b, 5a: slit, 4b: horn part, 6a, 7a: yoke through hole, 8a: magnetostrictive element through hole, 21a: outer peripheral tapered surface, 22b: bottom portion, 22d … Engaging recess (engaging portion), 23a… inner peripheral taper surface.

Claims (14)

[Claims] 1. A magnetostrictive element (8, 25a, 25b) for generating vibration by a change in a magnetic field based on an alternating current, and a yoke (8, 25a, 25b) forming a magnetic path by sandwiching the magnetostrictive element (8, 25a, 25b). 6, 7, 22 to 24), and a rotor (2, 21) that is pressed into contact with the stator (1, 20) and rotates based on the vibration. Characteristic magnetostrictive vibration motor. 2. A magnetostrictive element (8) that generates vibrations due to a change in a magnetic field, and a magnetic field coil (9) that is provided so as to surround an outer periphery of the magnetostrictive element (8) and generates an alternating magnetic field based on an alternating current. A bias magnetic field generating means (10) provided so as to surround the outer periphery of the magnetic field coil (9) and generating a bias magnetic field in one direction; and at least the magnetostrictive element (8) is held in the axial direction by A stator (1) having a magnetic field coil (9) and yokes (6, 7) forming a magnetic path together with the bias magnetic field generating means (10); and pressing contact with the axial end of the stator (1). And a rotor (2) that rotates based on the vibration. 3. The magnetostrictive vibration motor according to claim 2, wherein the magnetostrictive element through hole (8) penetrates through the magnetostrictive element (8) and the yoke (6, 7) of the stator (1) in the axial direction.
a) and yoke through holes (6a, 7a), and fastening members (11, 12) penetrating both through holes (6a to 8a).
Wherein the magnetostrictive element (8) and the yokes (6, 7) are fastened and pressurized is applied to the magnetostrictive element (8) via the yokes (6, 7). Vibration motor. 4. The magnetostrictive vibration motor according to claim 3, wherein the fastening member (11, 12) has a horn (4b) for increasing the amplitude of vibration of a contact surface of the rotor (2).
A magnetostrictive vibration motor characterized in that the two yokes (6, 7) are fastened via a metal block (4) formed with. 5. The vibration conversion block according to claim 3, wherein the fastening member has a slit formed to generate torsional vibration based on longitudinal vibration. A magnetostrictive vibration motor characterized in that the two yokes (6, 7) are fastened via 5). 6. The magnetostrictive vibration motor according to claim 3, wherein the rotor (2) has a slit (2b) for generating torsional vibration based on the vibration of the stator (1). A magnetostrictive vibration motor characterized by being formed. 7. Two groups of magnetostrictive elements (25) arranged in the circumferential direction and generating vibration by a change in magnetic field.
a, 25b) and each of the magnetostrictive elements (25
magnetic field coils (26a, 26b) provided so as to surround the a.25b) and generating an alternating magnetic field based on an alternating current
And the magnetic field coils (26a, 26a)
b) and a bias magnetic field generating means (27) for generating a bias magnetic field in one direction, and at least the magnetostrictive elements (25a, 25b) held in the radial direction to form the magnetic field coils (26a, 26b). ) And the yoke (22) forming a magnetic path together with the bias magnetic field generating means (27).
To 24), and two groups of the magnetostrictive elements (2
A stator (20) that supplies alternating currents having a phase difference of 90 degrees to the two groups of magnetic field coils (26a, 26b) corresponding to the two groups corresponding to 5a, 25b) and generates traveling wave vibration in the magnetostrictive elements (25a, 25b). ), And a rotor (21) pressed radially against the stator (20) and rotated based on the traveling wave vibration. 8. The magnetostrictive vibration motor according to claim 7, wherein the diameter of the yoke (23) arranged radially inside the magnetostrictive element (25a, 25b) is linear in the axial direction. The inner peripheral taper surface (23a) is formed on the outer peripheral surface of the rotor (21).
3a) is formed with an outer peripheral tapered surface (21a) capable of surface contact, and the rotor (21) is pressed in the axial direction so that the outer peripheral tapered surface (21a) comes into surface contact with the inner peripheral tapered surface (23a). A magnetostrictive vibration motor characterized by being brought into pressure contact. 9. The magnetostrictive vibration motor according to claim 7, wherein the yoke (22) arranged radially outside the magnetostrictive element (25a, 25b) forms a substantially cylindrical housing. A magnetostrictive vibration motor characterized by the following. 10. The magnetostrictive vibration motor according to claim 9, wherein the yoke (22) arranged radially outside the magnetostrictive elements (25a, 25b) is formed in a substantially bottomed cylindrical shape having a bottom. , The magnetostrictive element (25a,
25b) the yoke (23) arranged radially inward
And a detent engaging portion (22d) which is circumferentially engaged with the magnetostrictive vibration motor. 11. The magnetostrictive vibration motor according to claim 2, wherein said bias magnetic field generating means (10, 27) is a permanent magnet. 12. A magnetostrictive element (8, 25a, 25b) that generates vibration by a change in a magnetic field based on an alternating current, and a yoke (8, 25a, 25b) sandwiching the magnetostrictive element (8, 25a, 25b) to form a magnetic path. 6, 7, 22 to 24), wherein the rotor (2, 21) rotating based on the vibration is brought into pressure contact with the stator. 13. A magnetostrictive element (8) that generates vibrations due to a change in a magnetic field, and a magnetic field coil (9) that is provided so as to surround an outer periphery of the magnetostrictive element (8) and generates an alternating magnetic field based on an alternating current.
A bias magnetic field generating means (10) provided so as to surround the outer periphery of the magnetic field coil (9) and generating a unidirectional bias magnetic field; A magnetic field coil (9) and the bias magnetic field generating means (1);
And a yoke (6, 7) constituting a magnetic path together with the rotor (0), wherein the rotor (2) rotating based on the vibration is pressed against an axial end. 14. A group of two magnetostrictive elements (25) that are arranged in a plurality in the circumferential direction and generate vibration by a change in a magnetic field.
a, 25b), and a magnetic field coil (26a, 26b) that is provided so as to surround the magnetostrictive elements (25a, 25b) so as to avoid the radial direction and generates an alternating magnetic field based on an alternating current. Bias magnetic field generating means (27) provided to surround each of the magnetic field coils (26a, 26b) to generate a bias magnetic field in one direction, and at least the magnetostrictive elements (25a, 25b) are held in the radial direction. And a yoke (22 to 24) forming a magnetic path together with the magnetic field coils (26a, 26b) and the bias magnetic field generating means (27), and corresponding to the two groups of the magnetostrictive elements (25a, 25b). An alternating current having a phase difference of 90 degrees is supplied to the magnetic field coils (26a, 26b) of the two groups, and the magnetostrictive elements (25a, 25b)
Wherein a rotor (21) rotating on the basis of the traveling wave vibration is pressed and contacted in the radial direction.