JPH1066361A - Ultrasonic motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic motor which reduces the wear of the sliding friction surface between a vibration element and a moving element, improves the durability and facilitates the increase of an output with high cost performance. SOLUTION: An ultrasonic motor is composed of a vertical vibration element 1 which consists of metal elements with a piezoelectric element 2 between them and which generates an elastic vibration, a distortion vibration element 3 which converts the vertical vibration of the vertical vibration element 1 into a distortion vibration partially and forms an elliptical locus on a protrusion 3a formed on it, a magnet 6 which is provided on the surface of the protrusion 3a of the distortion vibration element 3 and a disc-type friction member 5 bonded to the surface of a rotor 4 which is brought into contact with the protrusion 3a of the distortion vibration element 3. A magnetic field obtained by the magnet 6 is applied to a sliding friction surface existing between the friction member 5 and the protrusion 3a of the distortion vibration element 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic motor which uses elastic vibration in an ultrasonic band as a driving source and can take out a reciprocating motion due to the vibration as a specific one-way motion by a frictional force.

[0002]

2. Description of the Related Art Conventionally, there are a standing wave type ultrasonic motor and a traveling wave type ultrasonic motor as ultrasonic motors.
The former forms a vibrating body by sandwiching piezoelectric ceramics that generate longitudinal vibration with metal, and elastic deformation when a moving body is pierced by a vibrator attached to one end of the vibrating body. The driving force is generated by conversion. In the latter, a vibrating body is formed by bonding piezoelectric ceramics and an elastic body such as a metal, and a moving body is brought into pressure contact with the vibrating body.

[0003]

The conventional ultrasonic motors described above have the following problems. That is, the former uses a longitudinal vibrator having a large vibration energy as a vibrating body, and thus has an advantage that the driving efficiency is large and the output is large, but the output transmission unit is limited to the same place where the contact area is small. As a result, the output transmission portion is greatly worn, and it has been difficult to put it to practical use.

[0004] On the other hand, the latter has the advantage that the contact area is larger and the contact portion is less worn than the former, but there is a problem in drive efficiency. Conventional ultrasonic motors
In order to improve the wear resistance of the contact surface, the contact surface of the metal elastic body with the rotor is coated with tungsten carbide or the like, and a ceramic film or the like is also formed on the surface of the moving body. Therefore, the manufacturing process becomes complicated, the manufacturing cost increases, and there is a problem in economy.

Further, when the pressing force of the ultrasonic motor is increased, the wear between the vibrating body and the moving body increases,
It is difficult to increase the output. The purpose of the present invention is
It was made to eliminate the above problems,
It is an object of the present invention to provide an ultrasonic motor that is economically advantageous, in which the wear of a sliding friction surface between a vibrating body and a moving body is reduced, durability is improved, and output is easily increased.

[0006]

According to a first aspect of the present invention, there is provided a vibrating body driven by elastic vibration in an ultrasonic band as a driving source, and a sliding friction with the vibrating body. In an ultrasonic motor comprising a moving body that is movable or rotatable in a predetermined direction by vibration from the vibrating body, at least one of the vibrating body and the moving body is made of a magnetic material, and the vibrating body and the An ultrasonic motor provided with magnetic field generating means for applying a magnetic field to a sliding friction surface near a sliding friction surface existing between moving bodies.

In order to achieve the above object, a second aspect of the present invention relates to the invention, wherein the magnetic field generating means is a member in which at least one of the vibrating body itself and the moving body itself is magnetized, or 2. The ultrasonic motor according to claim 1, wherein the magnet is a magnet provided on at least one of the sliding friction surfaces of the moving body, or a magnet arranged close to the vibrating body and the moving body. It is.

According to the first or second aspect of the present invention, since a magnetic field acts on the sliding friction surface between the vibrating body and the moving body, wear of the sliding friction surface is reduced and durability is improved. At the same time, the output can be easily increased, which is economically advantageous.

According to a third aspect of the present invention, there is provided a longitudinal vibration body for generating elastic vibration, and a torsional vibration body for converting a part of the longitudinal vibration obtained from the longitudinal vibration body into torsional vibration. And an ultrasonic motor provided with a moving body for forming an elliptical trajectory, which is provided on the upper part of the torsional vibrating body so as to make sliding friction. An ultrasonic motor characterized in that a magnetic field generating means for applying a magnetic field to a dynamic friction surface is formed.

According to the third aspect of the present invention, the magnetic field generated by the magnetic field generating means acts on the sliding friction surface between the torsional vibrator and the friction material. Thus, wear of the sliding friction surface is reduced.

In order to achieve the above object, an invention according to claim 4 is an annular shape in which a plurality of teeth are formed along a circumferential surface, and each of the teeth generates a vibration made of a magnetic material. A vibrating body, provided slidably with respect to each tooth portion of the vibrating body, a rotor rotatable by vibration from the vibrating body, and disposed close to the outer peripheral side of the vibrating body and the rotor; An ultrasonic motor having a magnetic field generating means for applying a magnetic field to the sliding friction surface.

In order to achieve the above object, the invention according to claim 5 has a plurality of teeth formed along a circumferential surface, has a magnetic field generating means formed on each tooth, and generates vibration. An ultrasonic motor comprising: an annular vibrating body; and a rotor slidably provided on each tooth portion of the vibrating body and rotatable by vibration from the vibrating body.

In order to achieve the above object, an invention according to claim 6 is an annular vibrator for generating vibration made of a magnetic material having a plurality of teeth formed along a circumferential surface; An ultrasonic motor including a rotor provided slidably with respect to each tooth portion of a body, rotatable by vibration from the vibrating body, and having a magnetic field generating means formed in a circumferential direction.

According to the invention corresponding to any one of claims 4 to 6, the magnetic field generated by the magnetic field generating means itself acts on the sliding friction surface between the vibrating body and the rotor. The wear of the sliding friction surface is reduced as compared with the ultrasonic motor.

In order to achieve the above object, an invention according to claim 7 is provided in a partially opened spherical cavity, which generates a surface wave vibration and has a plurality of grooves at predetermined intervals. An ultrasonic motor comprising: a stator in which magnetic field generating means are formed at edges of each groove; and a spherical rotor slidably disposed in an arbitrary direction on an inner peripheral surface of the stator. It is.

According to a seventh aspect of the present invention, since a plurality of magnetic field generating means are provided on the inner surface of the stator, the contact surface of the stator which comes into sliding contact with the surface of the rotor as the rotor rotates is worn. Can be reduced.

To achieve the above object, an invention according to claim 8 is provided in a cavity which is curved in one direction,
A plurality of grooves are formed at predetermined intervals while generating surface wave vibrations, magnets are formed at the edges of each groove, and a stator curved in one direction, and an arbitrary inner circumferential surface of the stator. An ultrasonic motor having a spherical rotor arranged to be slidable in a direction.

According to the invention, since the magnet is formed on the inner surface of the stator, the wear of the contact surface between the rotor and the stator can be reduced. In order to achieve the above object, an invention according to claim 9 is provided in a cavity which is curved in one direction, generates a surface wave vibration, and has a plurality of grooves formed at predetermined intervals, A stator curved in one direction, a spherical rotor rotatably disposed on an inner peripheral surface of the stator so as to be rotatable in an arbitrary direction, and a rotatable bearing for the rotor, and a magnetic field generating means on a roller or a ball. Is an ultrasonic motor including a bearing formed with a bearing.

According to the ninth aspect of the present invention, since the magnetic field generating means is formed on the roller or ball of the bearing, the wear of the contact surface between the rotor and the stator can be reduced. In order to achieve the above object, the invention corresponding to claim 10 is
A spherical rotor rotatably arranged in any direction,
The outer peripheral surface of the rotor is in surface contact with each other in the X-axis direction and the Y-axis direction perpendicular to each other, a plurality of teeth are formed along the circumferential surface, and a magnetic field generating means is formed on each of the teeth. And an ultrasonic motor having a stator for applying surface wave vibration to the rotor.

According to the tenth aspect of the present invention, since the magnetic field generating means is formed on the plurality of teeth of the stator, wear of the contact surface between the rotor and the stator can be reduced. In order to achieve the above object, an invention corresponding to claim 11 is
A rotor whose outer peripheral surface is spherical in at least six clamped portions, a housing accommodating the rotor and having a plurality of cavities, and applying a magnetic field to a contact surface accommodated in each of the cavities and in contact with the rotor Magnetic field generating means, at least three clamp members for clamping the rotor by arranging so as to hold the rotor by pressing one end against the outer peripheral surface of the rotor toward the center of the rotor, and the clamps; An ultrasonic motor having at least six piezoelectric members that house the other end of the member and each of the cavities and are respectively disposed in two axial directions of a tangential plane of the rotor and generate surface wave vibration. is there.

According to the eleventh aspect of the present invention, since the magnetic field generating means is formed on the clamp member, wear due to contact with the rotor is reduced, and the contact friction force is increased, so that the force due to slip is increased. Transmission loss can be reduced.

In order to achieve the above object, an invention corresponding to claim 12 includes a pair of supporting members having an L-shaped cross section, a rotating shaft rotatably supported between the supporting members, At least four vibrators disposed between the support members and generating surface wave vibration to rotate the rotation shaft;
An ultrasonic motor comprising: magnetic field generating means for applying a magnetic field to a contact surface of each of the vibrators with the rotating shaft.

According to the twelfth aspect of the present invention, the contact portion between the magnetic field generating means of the piezoelectric body and the rotating shaft forms a part of a magnetic circuit, so that both abrasion due to friction can be reduced. The structure can withstand long-term operation.

In order to achieve the above object, the invention according to claim 13 is directed to a linear movable magnetic body, and first, second, and third piezoelectric bodies for applying vibration to the movable magnetic body. A base supporting the first, second, and third piezoelectric bodies in a substantially T-shape and supporting one end of the first and second piezoelectric bodies so as to contact the movable magnetic body; An ultrasonic motor comprising a magnetic field generating means for applying a magnetic field to a contact portion.

According to the thirteenth aspect of the present invention, since the magnetic field generating means is formed at the contact portion of the base with the movable magnetic body, the base and the movable magnetic body are more movable than the conventional magnetic field generating means. Wear of the magnetic material is reduced.

[0026]

Embodiments of the present invention will be described below with reference to the drawings. [First Embodiment] FIG. 1 is a perspective view showing a main part of an ultrasonic motor according to a first embodiment of the present invention. This is a torsional connector type ultrasonic motor that employs a standing wave method as a type of elastic wave.
It includes a piezoelectric body 2, a torsional vibrator 3, a rotor 4, a friction material 5, and a magnet 6 that constitute a moving body MV.

This ultrasonic motor comprises a longitudinal vibrator 1 having a tangential drive component on a side surface of a moving body MV having a center of rotation.
To apply force to rotate the moving body MV.
That is, by using the longitudinal vibrator 1 using the piezoelectric material as the driving material, the vibration energy is transferred from the vibrator V to the mover MV via the frictional force of the contact portion between the mover MV and the vibrator V. This realizes the rotational movement of the body MV.

More specifically, the vertical vibrator 1 is a vertical vibrator that generates elastic vibration, and has a structure in which the piezoelectric body 2 is sandwiched between metals. The torsional vibrator 3 is entirely made of a magnetic material, and converts a part of the longitudinal vibration of the longitudinal vibrator 1 into torsional vibration to form an elliptical locus on the projection 3 a at the upper end of the torsional vibrator 3. On the surface of the projection 3a of the torsional vibrator 3, a magnet 6 having a polarity as shown in the figure is provided. A friction material 5 made of a disc-shaped magnetic material is adhered to a surface of the disc-shaped rotor 4 that comes into contact with the projection 3a of the torsional vibrator 3.

The magnet 6 shown in FIG. 1 may be magnetized on the projection 3a itself without being provided on the surface of the projection 3a of the torsional vibrator 3. Because of this configuration,
Part of the longitudinal vibration from the longitudinal vibrator 1 is converted into torsional vibration by the torsional vibrator 3 and transmitted to the rotor 4.
Rotates.

As described above, the magnet 3 is provided on the surface of the projection 3a provided at the upper end of the torsional vibrator 3 in contact with the disk-shaped friction material 5.
, The magnetic field generated by the magnet 6 itself becomes
Since it acts on the protrusion 3a of the torsional vibrator 3 and the sliding friction surface of the friction material 5, wear of the sliding friction surface is reduced as compared with the conventional standing wave type ultrasonic motor.

A conventional standing wave type ultrasonic motor is shown in FIG.
No magnet is formed on the projection 3a, and in this case, the output transmitting portion, that is, the projection 3a and the wear material 5 are greatly worn. The reason for this is that the standing wave type ultrasonic motor is driven based on the principle that the rotor 4 is driven by pushing the rotor 4 and that a vertical vibrator having a large vibration energy is used as the vibrating body.

In the present embodiment, as is clear from the principle and the experimental results described below, wear of the sliding friction surface is reduced. Hereinafter, this will be described. First, the principle of reducing wear by magnetism will be described with reference to FIG.
When magnetism acts on the sliding surface, gas adsorption, particularly oxygen adsorption, becomes active, and an oxide film is generated. When this oxide film intervenes on the sliding surface,
It has been confirmed that adhesion is reduced, wear powder becomes finer, and wear is reduced. The effect depends on the chemical composition or magnetic properties of the sliding material. That is, there is a difference in sensitivity to the environment such as the reaction to oxygen and the temperature depending on the material (or the chemical component contained in the material), and the effect is different for each material. A transition metal having a vacancy in the electron orbit or a ferromagnetic material containing a transition metal as a main component, for example, a steel material, is in a chemically non-equilibrium state and is in a state of being easily bonded to other elements. When magnetism acts on a sliding body made of such a material, the action of binding (ionic bond or covalent bond) with other elements is activated, and oxygen adsorption is promoted.
It is said that this reduces wear.

When magnetism acts on a ferromagnetic material, an attractive force proportional to the square of the magnetic flux density is generated. As the suction force increases, the friction force between the sliding surfaces also increases. Next, a test apparatus used to confirm the above-described principle (friction and wear characteristics by magnetism) will be described with reference to FIG.

FIG. 3A shows a pin-on-disk type test apparatus 20 using an electromagnetic coil, in which a rotating shaft 21 is disposed so as to be rotatable in a vertical direction, and an upper end of the rotating shaft 21 is a motor (M). It is configured so that the torque from the motor 22 is transmitted. A rotating plate 23 having a pin test piece insertion hole is inserted through the lower end of the rotating shaft 21, and the rotating plate 23 is rotated by two nuts 24 screwed to the lower end of the rotating shaft 21.
It is supported detachably. On the outer peripheral side of the rotating shaft 21, a cylindrical test piece support is supported by a fixing part (not shown), which is detachably attached to a cylindrical member 25 made of a magnetic material and a lower end of the cylindrical member 25 by bolts and nuts. And a circular ring-shaped holding plate 26 made of a magnetic material. 4 between the cylindrical member 25 and the holding plate 26.
A disk test piece 27 of a circular ring shape shown in FIG. 4B and made of a material to be described later is inserted, and a pin test piece of the material shown in FIG. The lower end of the piece 28 is inserted and the pin test piece 2
8 is configured such that a predetermined load is applied to the lower surface of the disk test piece 27, and the pin test piece 28 slides on the lower surface of the disk test piece 27 as the rotating plate 23 rotates. . Then, the cylindrical member 25 and the holding plate 26
A cylindrical electromagnetic coil 29 is disposed on the outer peripheral side of the disk test piece 27 and the pin test piece 28, and a magnetic field of a desired magnetic flux density is applied to a sliding surface of the disk test piece 27 and the pin test piece 28. It can be applied. In addition, the pin test piece 2
The disk test piece 27 and the pin test piece 28
A search coil 31 for measuring the density of the magnetic flux applied to the sliding surface is provided.

FIG. 3B shows a pin-on-disk type test apparatus 30 using a permanent magnet, which is different from FIG. 3A in that the electromagnetic coil 29 is not provided and a predetermined magnetic field is applied. A permanent magnet 32 generated and a return yoke 33 for forming a magnetic circuit of a magnetic flux generated from the permanent magnet 32 are provided.

The test conditions at the time of performing a test using the test apparatus as described above are as follows. Sliding speed is 10 (cm /
s), the load is 20 (N) or 100 (N), and the surface pressure is 1.
0 (N / mm ² ) or 10 (N / mm ² )
The temperature is room temperature, the type of magnetic field is either AC (50 HZ) or DC, or a permanent magnet, and the magnetic flux density is 0 to 100 (mT).

FIG. 5 (a) shows a wear characteristic diagram (slip distance l (m) and wear amount w (mg) of a pin test piece made of a hard steel wire (SWRH60A) under the above test conditions. FIG. 5 (b) is a wear characteristic diagram (a diagram showing the relationship between the slip distance l (m) and the wear amount w (mg)) of a disk test piece made of spheroidal graphite cast iron (FCD700).

In the characteristic diagram of FIG. 5, B = less wear
FIG. 6 is an enlarged view of the wear characteristics of 40, 60, 80, and 100 (mT). As is apparent from this figure, the amount of abrasion greatly changes when the slip distance 1 is 100 to 200 (mm). In this figure, the expected wear in a region with a large amount of wear can be defined as “severe wear”, and the wear in a region with a small amount of wear can be defined as “mild wear”.
This is because, by applying a magnetic field, gas adsorption is promoted, and the transition from severe wear to mild wear is accelerated.

FIG. 7 is a diagram showing the relationship between the magnetic flux density and the wear amount ratio (specific wear amount). As is apparent from this figure, when the magnetic flux density is between 40 and 100 (mT), the magnetic flux density becomes zero. 1/2 of the rope material (hard steel wire SWRH69A) compared to the case,
It is about 1/100 for sheave material (spheroidal graphite cast iron FCD700).

FIG. 8 shows a cross-sectional profile of the disk test piece (FCD700) after the test.
(N), when the magnetic flux density B = 40 to 100 (mT),
It can be seen that the abrasion is less than B = 0,20 (mT).

Further, the relationship between the magnetic flux density and the frictional force ratio is as shown in FIG. 9, and the frictional force is increased, so that the slip is further reduced. In the above-described embodiment, as the magnetic field generating means,
Although the case where the permanent magnet 6 is used has been described, the present invention can be similarly applied to a case where an electromagnetic coil is used instead of the permanent magnet 6.

The characteristic diagrams (FIGS. 5 to 8) described in the first embodiment are all typical examples of the embodiment.
Even if this is another material, the same tendency is shown, so the attachment of the drawing and the description thereof are omitted.

In the above-described embodiment, the case where an oxide magnet having a residual magnetic flux density of 100 mT is used as the permanent magnet 6 has been described as an example. To 1.45 T, rare earth magnets of 0.65 to 1.20 T, oxide magnets of 0.20 to 0.45 T, bond magnets of 0. 065 to 0.90 T.

In the description of FIG. 1, the case where the disk-shaped wear material 5 is adhered to the surface of the rotor 4 has been described. However, the wear material 5 may not be provided on the surface of the rotor 4.
In this case, the sliding friction surface makes contact between the magnet 6 and the rotor 4. Further, as shown in FIG. 1, the magnet 6 is not formed on the projection 3a of the torsional vibrator 3 and a magnet is formed on the wear material 5, or when the wear material 5 is not provided on the rotor 4, a magnet is formed on the rotor 4. Even if it is formed, the same effect as described above can be obtained.

[Second Embodiment] FIGS. 10A and 10B show an example in which the present invention is applied to a known traveling wave type ultrasonic motor. FIG. 10A is a sectional view of a main part thereof, and FIG. In this configuration, an annular magnet 7 is disposed on the outer peripheral portions of the vibrating body V and the moving body MV via a predetermined gap. In this case, the vibrating body V is an annular metal elastic body 8 made of a magnetic material having a plurality of teeth (not shown) formed at equal intervals in the circumferential direction;
The piezoelectric body 9 is adhered to the bottom surface of the metal elastic body 8.

The moving body MV has an annular rotor 10 having the same diameter as the vibrating body V, and a friction material 11 adhered to a surface of the rotor 10 that slides on the vibrating body V. By forming a closed magnetic path between the magnet 7, the rotor 10 and the metal elastic body 8 in this way, the magnetic field generated by the magnet 7 acts on the sliding friction surface between the vibrating body V and the friction material 11. As in the first embodiment, the sliding friction surface has less wear than the conventional traveling wave type ultrasonic motor.

[Third Embodiment] FIG. 11 shows an example in which the present invention is applied to a known traveling wave type ultrasonic motor similar to that shown in FIG. It is magnetized so as to have an N pole on the inner circumference side and an S pole on the outer circumference side in the diameter direction. Other points are the same as those in FIG.

As a result, the third embodiment also has the above-described second embodiment.
As in the first embodiment, the sliding friction surface has less wear than the conventional traveling wave type ultrasonic motor. Fourth Embodiment FIG. 12 shows an example in which the present invention is applied to a known traveling wave type ultrasonic motor similar to that shown in FIG. Magnetized,
For example, the magnets are alternately magnetized to different polarities, such as N, S, N, S, for each tooth, or NN, SS when the number of teeth is odd, or magnetized plurally. It is something to do. Other points are the same as those in FIG.

As a result, the fourth embodiment also has the above-mentioned second embodiment.
As in the first embodiment, the sliding friction surface has less wear than the conventional traveling wave type ultrasonic motor. Fifth Embodiment FIG. 13 shows an example in which the present invention is applied to a known traveling wave type ultrasonic motor similar to FIG.
This is a view in which two types of moving bodies MV of the rotor 3 and the rotor 14 are virtually arranged on the same vibrating body V, and are actually used in combination separately. The rotor 13 is annular and is magnetized so that the polarity of N and the polarity of S are alternately formed in the circumferential direction.

The rotor 14 has an annular shape and is magnetized in the circumferential direction. For example, the rotor 14 is magnetized such that the inner circumference has N polarity and the outer circumference has S polarity. Other points are the same as those in FIG.

As a result, the fifth embodiment also has the above-described second embodiment.
As in the first embodiment, the sliding friction surface has less wear than the conventional traveling wave type ultrasonic motor. Sixth Embodiment FIG. 14 shows an ultrasonic motor adapted to be applied to, for example, a joint of a manipulator.
And (b) are a sectional view and a front view thereof, and (c)
Is a diagram for explaining the principle. This embodiment also includes a moving body MV and a vibrating body V, similar to the above-described embodiment, and the vibrating body V is fixed to the arm 41 and has a spherical shape so as to form a cavity therein. A vibrating body case 42 that can be divided and provided; and a linear surface vibrator that is attached to the inner surface of the vibrating body case 42 and generates a surface wave vibration that is arranged in a cross shape so that the traveling directions of the surface waves are orthogonal to each other. And two arc-shaped stators 43, 44 in which slit-shaped grooves 43a, 44a are formed at regular intervals on the surface of a rotor 45, which will be described later, and are adhered between the grooves of the stators 43, 44, respectively. A magnet 47 is provided.

The moving body MV has a spherical rotor 45 provided in surface contact with the inner surfaces of the stators 43 and 44 so as to be rotatable in an arbitrary direction, and an arm 46 integrally connected to a part of the rotor 45. It has.

With this configuration, the rotor 4
When the stator 43 or 44 is brought into contact with the outer peripheral surface of the stator 5 to generate surface wave vibration, the rotation axis Z perpendicular to the circumferential direction in which the stator 43 or 44 extends is obtained.
, The arm 46 can be rotated in two orthogonal directions θx and θy. In this case, since the plurality of magnets 47 are provided on the inner surfaces of the stators 43 and 44, the contact between the stators 43 and 44 comes into contact with the surface of the rotor 45 as the rotor 45 rotates as in the above-described embodiment. Surface wear can be reduced.

Seventh Embodiment FIGS. 15A and 15B show an ultrasonic motor similar to FIG. 14, wherein FIG. 15A is a perspective view showing stators 43 and 44 and a magnet 47, and FIG. FIG. 4 is a plan view showing a relationship between a rotor 45 and stators 43 and 44. The inner surfaces of the stators 43 and 44 are formed into spherical surfaces having substantially the same curvature as the rotor 45, and are curved in only one direction, and are in line contact with the rotor 45. Specifically, the stators 43 and 44 come into contact with the rotor 45 along a curve 48 and have a straight surface in a direction perpendicular to the curve 48.

As a result, not only the advantage that the manufacture of the stators 43 and 44 is facilitated, but also the magnets 47 are formed on the inner surfaces of the stators 43 and 44 similarly to the above-described embodiment, Wear of the contact surfaces of the stators 43 and 44 can be reduced.

[Eighth Embodiment] FIGS. 16A and 16B show an ultrasonic motor similar to FIG. 15, wherein FIG. 16A is a perspective view showing stators 43 and 44 and a magnet 47, and FIG. FIG. 4 is a plan view showing a relationship between a rotor 45 and stators 43 and 44. The difference from FIG. 15 is that a V-shaped groove 49 is formed on the surfaces of the stators 43 and 44 along the contact direction, and the other points are the same as FIG. With such a configuration, the stators 43 and 44 have two curves 5
0, the contact area between the rotor 45 and the stators 43 and 44 increases, and the driving force of the rotor 45 increases.
Since the magnets 47 are formed on the inner surfaces of the rotors 3 and 44, the wear of the contact surfaces between the rotor 45 and the stators 43 and 44 can be reduced.

[Ninth Embodiment] FIG. 17 is a front view of an ultrasonic motor, in which a ball or roller 51 of a bearing arranged opposite to a stator 43, 44 is formed of a magnet, and the bearing is a rotor 45. Is contacted. Thus, the rotor 45 can be rotatably supported by the stators 43 and 44 and the bearing.
Note that a mark 53 for detecting the origin is formed on the rotor 45, and a mark 53 for detecting the rotation angle of the rotor 45 in the rotation direction of the stators 43 and 44 is formed on the outer periphery of the rotor 45.
Two non-contact encoders 52 are provided. In addition,
An arm 46 is integrally connected to a part of the rotor 45.

As in the previous embodiment, the stators 43, 4
4 has a magnet 47 formed on the inner surface thereof.
Wear of the contact surfaces of the stator 43 and the stator 43, 44 can be reduced. Tenth Embodiment FIGS. 18A and 18B show a rotary ultrasonic motor. FIG. 18A is a perspective view of the rotary ultrasonic motor, and FIG. 18B is an enlarged perspective view of a stator which is a part of the configuration. This is because a spherical rotor 55 having an arm 54 and rotatably supported in an arbitrary direction by a support member (not shown) is provided on the surface of the rotor 55 in the X and Y axis directions orthogonal to each other. The stators (vibrators) 56 and 57 are in contact with each other. The stator 56 has an annular metal elastic body 58.
N-pole in the diametric direction and on the inner peripheral side with respect to each tooth portion 58a,
A magnet is formed by being magnetized so as to be an S pole on the outer peripheral side, and a piezoelectric body 5
9, and the stator 57 has the same configuration as the stator 56.

In the ultrasonic motor having such a configuration,
Driving the stator 56 rotates the rotor 55 around the X axis, and driving the stator 57 rotates the rotor 55 around the Y axis. Thus, by rotating the rotor 55 by the stators 56 and 57, the arm 54 can be rotated in an arbitrary direction.
By rotating the rotor 55, the stators 56, 5
When the rotor 7 comes into surface contact with the rotor 7, the contact surface is worn. However, since the magnets are formed on the teeth of the metal elastic bodies of the stators 56 and 57, the magnets are formed on the teeth of the stators 56 and 57. The abrasion is reduced as compared with the conventional example in which no metal is formed.

[Eleventh Embodiment] FIG. 19 is a partial sectional view of an ultrasonic motor, which comprises a moving body MV and a vibrating body V. The moving body MV has a substantially spherical shape (a part of which is connected to an arm 60). The part to be clamped has a spherical surface).
have. A housing having a plurality of (in this case, eight, specifically, four in the figure and four, not shown, arranged in the direction of the paper) a plurality of vibrating bodies V for housing piezoelectric bodies 62a 62 and each cavity 62a of the housing 62
One end of the clamping piezoelectric body 63 and the moving piezoelectric body 64 accommodated in the piezoelectric body 63 and the outer peripheral surface of the rotor 61 are in contact with each other, and the other end is connected to one end of each of the piezoelectric bodies 63 and 64 via a hinge 65. Clamp members 66a to 66, which are magnetized to have characteristics as shown in the drawing and supported by a metal elastic body (not shown) to form a closed magnetic circuit.
d and virtual clamp members 66e to 66h (not shown)
(Either of these and the clamp members 66a to 66-6
6d) and a hinge 67 disposed between the bottom surface of the cavity 62a and the other ends of the piezoelectric bodies 63 and 64). Consists of Then, the clamp member 66a
The circuit is formed such that when the magnets incorporated in the rotors 66h to 66h are brought into contact with the outer surface of the rotor 61, a portion between the contact points of the rotor 61 becomes a part of the magnetic circuit.

The hinges 65 and 67 are provided at both ends of the piezoelectric bodies 63 and 64 in order to reduce bending stress and shear force acting on the piezoelectric bodies 63 and 64. With such a configuration, the following operation and effect can be obtained. First, the clamp member 66e and the clamp members 66a and 66d (not shown) are pressed against the surface of the rotor 61 by using the piezoelectric body 63 for clamping, and the clamp member 66f and the clamp members 66c and 66b (not shown) operate the piezoelectric body 63 for clamp. Consider a case where the pressing on the rotor 61 is released. Clamp members 66a, 6
6d, 66e, 66h piezoelectric body for movement attached to 66h
4 is operated so that a rotational component of the rotor 61 around the Y axis remains.

Before the arm 60 rotates a predetermined amount, the clamping piezoelectric members 63 a, 66 d, 66 e, and 66 h are actuated and pressed by the rotor 61. The moving piezoelectric body 64 attached to the clamp members 66a, 66d, 66e, and 66h is made to work so that the rotational component around the Y axis of the rotor 61 remains at the same time as the contact with the rotor 61. Clamp members 66a, 66d, 66
At the same time when the e and 66h come into contact with the rotor 61, the clamp members 66a, 66d, 66e and 66h actuate the clamp piezoelectric body 63 to release the pressing on the rotor 61. Move in the anti-rotation direction with just the same. Hereinafter, the same operation is repeated to rotate the rotor 61 by the same amount as the rotation amount around the Y axis. What has been described above is about the rotation of the rotor 61 around the Y axis.
The rotation of the rotor 61 around an axis in an arbitrary direction can be performed.

As a result, according to the eleventh embodiment, the rotor 61 can be rotated about an axis in an arbitrary direction, and the magnets are embedded in the clamp members 66a to 66h of the rotor 61, and the rotor 61 is closed via the rotor 61. Since the path is formed, the wear due to the contact between the clamp members 66a to 66h and the rotor 61 is reduced, and the loss of power transmission due to slippage can be reduced because the contact friction force increases.

In the embodiment shown in FIG. 19, the rotor 61 having the arm 60 is clamped by eight sets of clamp members. The rotor 61 having the arm 60 is clamped by six sets of clamp members. Can be similarly implemented.

The hinges 65, 67 are provided at both ends of the piezoelectric bodies 63, 64 in order to reduce bending stress and shear force acting on the piezoelectric bodies 63, 64. [Twelfth Embodiment] FIG. 20 shows an ultrasonic motor that operates like a scale insect. A support member 71 made of a pair of magnetic materials having an L-shaped cross section and a pair of clamp members 72 are shown.
, Four spring members 73, a rotating shaft 74, four piezoelectric bodies 75 a, 75 b, 75 c, 75 d, and each piezoelectric body 75 a
It is composed of magnets adhered to the surfaces of 75d so as to have N and S polarities as shown in the figure. The two ends of the clamp members 72 are connected by a clamp member 72 having a spring member 73, and one end of a piezoelectric body 75 is fixed near both ends of the support member 71, respectively.
A magnet is attached to the other end of 5d. in this case,
The configuration is such that the polarities of the contact portions of the magnets of the adjacent piezoelectric bodies 75 are different, and a magnetic circuit is formed between the piezoelectric body 75, the support member 71, and the rotating shaft 74.

The embodiment having such a configuration has the following operational effects. When the pressing force of the piezoelectric body 75a is set to the minimum state, the pressing force of the piezoelectric bodies 75b and 75c is set between the two, and the pressing force is changed clockwise with time, the rotating shaft 74 is displaced in the maximum pressing direction. While rotating like a counterclockwise waffle motor. Counterclockwise rotation can be achieved by changing the point at which the maximum pressing force acts counterclockwise.

As described above, according to the twelfth embodiment, the contact portions between the magnets of the piezoelectric bodies 75a to 75d and the rotating shaft 74 form a part of the magnetic circuit. And a structure that can withstand long-term operation.

[Thirteenth Embodiment] FIG. 21 shows a linear type ultrasonic motor. A moving body MV composed of a linear movable magnetic body 110, a base 111 composed of a magnetic material having a substantially B-shaped cross section, The first, second, and third piezoelectric bodies 112, 1 are respectively provided on other sides except the bottom side of the base 111.
13 and 114 are fixed and formed of a vibrating body V combined in a substantially T-shape, and a contact portion 111a of the base 111 which comes into contact with the movable magnetic body 110 is magnetized to N polarity or S
Polarized, and the side facing the piezoelectric bodies 112 to 114 is S
The magnet 115 magnetized to the polarity or the N polarity is formed.

In such a configuration, the vibrating body V
That is, by driving the piezoelectric bodies 112, 113, and 114, the base 111 vibrates while drawing oblique, elliptical, and circular trajectories, so that the movable magnetic body 110 moves on the contact portion 111a of the base 111.

According to the thirteenth embodiment, the base 111
Since the magnet 115 is formed in the contact portion 111a of
The contact portion 11 is compared with a conventional magnet having no magnet.
1a and the wear of the movable magnetic body 110 are reduced.

The magnet 115 can be magnetized so as to have N and S polarities along the contact portion 111a of the base 111, unlike FIG.
A similar effect can be obtained since a closed magnetic path is formed between the points a.

[Fourteenth Embodiment] FIG. 22 shows a linear type ultrasonic motor similar to FIG. 21, in which a moving body MV comprising a linear movable magnetic body 110 and a magnetic material having a substantially U-shaped cross section are provided. , A connecting body 120 fixed to the base 121, and first and second piezoelectric bodies 122 and 12 fixed to each other in a straight line with the connecting body 120 interposed therebetween.
3, a third piezoelectric body 124 having one end fixed to the connecting body 120 so that the piezoelectric bodies 122 and 123 are at right angles,
The movable magnetic body 11 fixed to the other end of the third piezoelectric body 124
The driving member 125 is made of a superalloy that contacts and supports the contact member 0. The driving member 125 and the piezoelectric body 124 each include a vibrating body V having a magnet magnetized to have a polarity as shown in the drawing. I have.

In such a structure, the vibrating body V
That is, by driving the piezoelectric bodies 122, 123, and 124, the base 121 vibrates while drawing oblique, elliptical, and circular trajectories.
Move up.

According to the fourteenth embodiment, since the distal end of the third piezoelectric member 124 and the driving member 125 fixed to the distal end of the piezoelectric member 124 are formed with magnets, respectively.
The driving member 1 is compared with the conventional one in which the magnet is not formed.
25 and the wear of the movable magnetic body 110 are reduced.

It should be noted that the magnets formed on the driving member 125 and the piezoelectric member 124 as shown in FIG. A similar effect can be obtained since a closed magnetic path is formed between the magnetic poles 125.

[Modification] In the embodiment described above,
Although an example in which a permanent magnet is used as the magnetic field generating means and an example in which a magnetic material itself is magnetized to form a magnet have been described, this may be replaced with an electromagnet. Further, the magnetic field generating means may be formed not only on one of the contact part of the vibrating body V or the contact part of the moving body MV but also on both.

Further, the contact portion of the vibrating body V and the moving body MV
At least one of the contact portions is made of, for example, a ferromagnetic material or an austenitic stainless material such as JIS SUS, which is not limited to this, and abrasion powder changes to a ferromagnetic material during sliding even if it is a paramagnetic material. You may comprise.

Further, the ferromagnetic material or the paramagnetic material may be provided or coated only on the contact portion (sliding portion) of the wear material of the above-described embodiment.

[0079]

According to the present invention described above, the wear of the sliding friction surface between the vibrating body and the moving body is reduced, the durability is improved, and the output is easily increased, which is economically advantageous. An ultrasonic motor can be provided.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a first embodiment of an ultrasonic motor according to the present invention.

FIG. 2 is a view for explaining the principle of the ultrasonic motor according to the embodiment shown in FIG. 1;

FIG. 3 is a diagram showing a schematic configuration of a test apparatus for testing a test piece based on the principle of FIG. 2;

FIG. 4 is a view showing the test piece of FIG. 3;

FIG. 5 is a wear characteristic diagram for explaining the effect of magnetic flux density on wear characteristics tested by the test apparatus of FIG. 3;

6 is a characteristic diagram in which a part of the wear characteristic diagram of FIG. 5 is enlarged.

FIG. 7 is a characteristic diagram showing a relationship between a magnetic flux density and a wear amount ratio tested by the test device of FIG. 3;

FIG. 8 is a view showing a cross-sectional profile of a test piece after a test performed by the test apparatus of FIG. 3;

FIG. 9 is a view showing magnetic-frictional force characteristics for explaining the operation and effect of the embodiment of FIG. 1;

FIG. 10 is a view for explaining a second embodiment of the ultrasonic motor according to the present invention.

FIG. 11 is a view for explaining a third embodiment of the ultrasonic motor according to the present invention.

FIG. 12 is a view for explaining a fourth embodiment of the ultrasonic motor according to the present invention.

FIG. 13 is a diagram illustrating a fifth embodiment of the ultrasonic motor according to the present invention.

FIG. 14 is a view for explaining a sixth embodiment of the ultrasonic motor according to the present invention.

FIG. 15 is a view for explaining a seventh embodiment of the ultrasonic motor according to the present invention.

FIG. 16 is a view for explaining an eighth embodiment of the ultrasonic motor according to the present invention.

FIG. 17 is a view for explaining a ninth embodiment of an ultrasonic motor according to the present invention.

FIG. 18 is a view for explaining a tenth embodiment of the ultrasonic motor according to the present invention.

FIG. 19 is a diagram illustrating an eleventh embodiment of the ultrasonic motor according to the present invention.

FIG. 20 is a diagram for explaining a twelfth embodiment of the ultrasonic motor according to the present invention.

FIG. 21 is a view for explaining a thirteenth embodiment of the ultrasonic motor according to the present invention.

FIG. 22 is a diagram illustrating a fourteenth embodiment of the ultrasonic motor according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... longitudinal vibration body, 2 ... piezoelectric body, 3 ... torsional vibration body, 6 ... magnet, 9 ... piezoelectric body, 10 ... rotor, 11 ... friction material, 12 ... ferromagnetic body, 13, 14 ... rotor, 41 , 46 ... arm, 42 ... vibrating body case, 43, 44 ... stator, 45 ... rotor, 47 ... magnet, 48 ... curve, 49 ... groove, 50 ... curve, 51 ... ball or roller, 54 ... arm, 55 ... rotor , 56, 57: Stator (vibrating body), 58: Metal elastic body, 59: Piezoelectric body, 60: Arm, 61: Rotor, 62: Housing, 63, 64: Piezoelectric body, 65, 67: Hinge, 66: Clamp Member: 71: support member, 72: clamp member, 73: spring member, 74: rotating shaft, 75: piezoelectric body, 110: movable magnetic body, 111: base, 112, 113, 114: piezoelectric body, 115: magnet, 121 ... Scan, 122, 123 ... piezoelectric, 125 ... driving member.

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Takeshi Uchida 1 Toshiba-cho, Fuchu-shi, Tokyo Toshiba Corporation Fuchu Plant

Claims (13)

[Claims] 1. A vibrating body driven by elastic vibration in an ultrasonic band as a driving source, and a movable body provided to be slidably rubbed against the vibrating body and capable of moving or rotating in a predetermined direction by vibration from the vibrating body. In an ultrasonic motor composed of a body, at least one of the vibrating body and the moving body is made of a magnetic material, and a magnetic field is applied to the sliding friction surface near a sliding friction surface existing between the vibrating body and the moving body. An ultrasonic motor comprising a magnetic field generating means for applying. 2. The magnetic field generating means is a member in which at least one of the vibrating body itself and the moving body itself is magnetized, or provided on at least one of a sliding friction surface of the vibrating body and the moving body. 2. The ultrasonic motor according to claim 1, wherein the ultrasonic motor is a magnet or a magnet disposed close to the vibrating body and the moving body. 3. A torsional vibrator for generating an elastic vibration, a torsional vibrator for converting a part of the longitudinal vibration obtained from the longitudinal vibrator to torsional vibration, and a sliding friction on an upper portion of the torsional vibrator. An ultrasonic motor provided with a moving body that forms an elliptical trajectory, wherein at least one of the torsional vibrator and the sliding friction surface of the moving body has magnetic field generating means for applying a magnetic field to the sliding friction surface. Ultrasonic motor characterized. 4. A plurality of teeth are formed along a circumferential surface,
And an annular vibrating body in which each tooth portion generates a vibration made of a magnetic material; and a rotor slidably provided with respect to each tooth portion of the vibrating body, the rotor being rotatable by vibration from the vibrating body. An ultrasonic motor including a magnetic field generating means disposed close to the outer peripheral side of the vibrator and the rotor and applying a magnetic field to the sliding friction surface. 5. A plurality of teeth are formed along a circumferential surface,
An annular vibrating body having magnetic field generating means formed on each tooth portion and generating vibration; and a slidably provided for each tooth portion of the vibrating body, rotating by the vibration from the vibrating body. Ultrasonic motor with a possible rotor. 6. An annular vibrating body for generating vibration made of a magnetic material having a plurality of teeth formed along a circumferential surface, and slidably provided on each tooth of the vibrating body. An ultrasonic motor including a rotor rotatable by vibration from the vibrating body and having a magnetic field generating means formed in a circumferential direction. 7. A magnetic field generating means which is disposed in a partially open spherical cavity, generates a surface wave vibration, and has a plurality of grooves formed at predetermined intervals, and a magnetic field generating means at an edge of each groove. An ultrasonic motor comprising: a stator formed with a sphere; and a spherical rotor slidably disposed in an arbitrary direction on an inner peripheral surface of the stator. 8. A plurality of grooves are provided in a cavity which is curved in one direction, generates a surface wave vibration, and has a plurality of grooves formed at predetermined intervals, and a magnet is formed at an edge of each groove. ,
An ultrasonic motor comprising: a stator curved in one direction; and a spherical rotor disposed on an inner peripheral surface of the stator so as to be rotatable in an arbitrary direction. 9. A stator which is disposed in a cavity which is curved in one direction, generates a surface wave vibration, has a plurality of grooves formed at predetermined intervals, and has a stator which is curved in one direction. An ultrasonic motor including a spherical rotor disposed on the inner peripheral surface so as to be slidable in an arbitrary direction, a bearing rotatably supporting the rotor, and a roller or a ball having a magnetic field generating means formed thereon. . 10. A spherical rotor rotatably disposed in an arbitrary direction and an outer peripheral surface of the rotor, which are in surface contact with each other in an X-axis direction and a Y-axis direction orthogonal to each other, and An ultrasonic motor having a plurality of teeth formed along the plurality of teeth, a magnetic field generating means formed on each of the teeth, and a stator for applying surface wave vibration to the rotor. 11. A rotor whose outer peripheral surface has at least six spherically clamped portions, a housing for accommodating the rotor and having a plurality of cavities, a housing accommodated in each of the cavities, and contact with the rotor. Magnetic field generating means for applying a magnetic field to the surface is formed, and one end is pressed against the outer peripheral surface of the rotor in the direction of the center of the rotor so as to hold the rotor and clamp the rotor.
Clamp members and the other end of each of the clamp members and the cavity are respectively housed in each of the cavities.
An ultrasonic motor, comprising: at least six piezoelectric members arranged in an axial direction and generating surface wave vibration. 12. A pair of supporting members having an L-shaped cross section, a rotating shaft rotatably supported between the supporting members, and a rotating shaft disposed between the rotating shaft and the supporting member to generate surface wave vibration. An ultrasonic motor comprising: at least four vibrators for rotating the rotating shaft; and magnetic field generating means for applying a magnetic field to a contact surface of each of the vibrating bodies with the rotating shaft. 13. A linear movable magnetic body, and first, second, and third movable vibrators for applying vibration to the movable magnetic body.
And a base for combining the first, second, and third piezoelectric bodies in a substantially T-shape, and supporting one end of the first and second piezoelectric bodies so as to be in contact with the movable magnetic body. An ultrasonic motor comprising a magnetic field generating means for applying a magnetic field to a contact portion with a movable magnetic body.