JPS6315677A - Ultrasonic motor-generator - Google Patents

Abstract

PURPOSE:To enable mutual conversion between electric energy and mechanical energy in simple constitution, by a method wherein ultrasonic torsional vibration is produced in a piezo-electric torsional vibrator by electric energy, and a rotor is rotated by interaction to ultrasonic vertical vibration. CONSTITUTION:A stator 1 comprises an ultrasonic elliptic vibrator provided with a piezo-electric vertical vibrator 4 to which voltage of AC power source 20 is applied, and piezo-electric torsional vibrators 2, 3 to which an electric system 21 is connected, and a rotor 22 to which a mechanical system 24 is connected is press-fonded to the stator 1. Ultrasonic torsional vibration is produced in the piezo-electric torsional vibrators 2, 3 by the electric system 21 or the mechanical system 24, and at the same time the piezo-electric vertical vibrator 4 is vibrated electrically so that mutual conversion between electric energy of the electric system 21 and rotational energy of the mechanical system 24 is performed by pumping action.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ultrasonic motor generator using ultrasonic vibrations.

[Conventional technology]

In recent years, devices that convert electrical energy into mechanical energy using ultrasonic vibrations of piezoelectric elements have attracted attention, and research and development is underway. An example of such a device is an ultrasonic motor that converts this ultrasonic vibration into rotational motion. An ultrasonic motor consists of a stator of an ultrasonic vibrator and a rotor that is crimped onto the stator. It rotates.

The present inventor has previously devised various ultrasonic vibrators that generate ultrasonic elliptical vibrations in this way, and one example uses a piezoelectric element that generates ultrasonic thickness vibrations. The piezoelectric element is arranged so that its thickness direction is parallel to the rotational axis of the rotor, and an AC voltage is applied to the piezoelectric element to generate ultrasonic vibration (hereinafter referred to as ultrasonic vibration) in a direction parallel to the central axis of the ultrasonic transducer. This method generates longitudinal vibrations (called longitudinal vibrations) and converts them into ultrasonic elliptical vibrations using conversion means having a specific structure (Japanese Patent Application No. 172,429/1982). Other examples include:
Since the above-mentioned ultrasonic elliptical vibration is considered to consist of ultrasonic longitudinal vibration and ultrasonic torsional vibration centered on the central axis of the ultrasonic vibrator, a disk-shaped piezoelectric element that generates ultrasonic thickness vibration and a disc-shaped piezoelectric element that generates ultrasonic torsional vibration are arranged so that their respective central axes coincide with the central axis of the ultrasonic vibrator, and alternating current voltages with the same frequency and phase synchronization are simultaneously applied to them. , ultrasonic longitudinal vibration and ultrasonic torsional vibration generated from these are synthesized to generate ultrasonic elliptical vibration (Japanese Patent Application No. 59-240823).

An ultrasonic electric motor using such an ultrasonic vibrator can be made compact because it has a low rotational speed but can obtain a large torque.
In addition, it has excellent features such as low power loss, simple configuration, and reduction in motor cost.

[Problem that the invention seeks to solve]

By the way, in electric motors and generators, especially AC rotating machines, that utilize electromagnetic interaction using coils, the electric action and power generation action are reversible, so they can be combined to generate mechanical energy. Motor-generators that allow mutual conversion with electrical energy currently exist and are in use. Such a motor generator provides rotational energy to a mechanical system connected to it by supplying electric power (air energy), and the rotational energy possessed by the mechanical system is greater than the rotational energy generated by the supplied electrical energy. When the electrical energy supply becomes large, or when the supply of electrical energy is stopped while the mechanical system is rotating, electrical energy is generated and consumed, resulting in a braking action, which reduces the electrical energy supplied to the mechanical system. It can be rotated or stopped according to the energy required.

On the other hand, a piezoelectric element has a reversible function in that it deforms when a voltage is applied to it, and generates a voltage when it is deformed. Therefore, we connected two Langevin-type ultrasonic transducers (longitudinal mode ultrasonic transducers) with the same characteristics, which are commonly used as ultrasonic generators, in series by crimping their end faces, and connected one ultrasonic transducer to an AC current. When a driving voltage of occurs. In other words, in such a device, one ultrasonic transducer converts electrical energy into mechanical energy, and the other ultrasonic transducer converts mechanical energy into electrical energy. Mutual conversion with mechanical energy becomes possible.

Extending this idea, ultrasonic motors can also be thought of as being able to exchange electrical energy with mechanical energy. Incidentally, in such an ultrasonic electric motor, a rotor is crimped onto a stator equipped with an ultrasonic vibrator, and the ultrasonic vibrator generates ultrasonic elliptical vibration in the stator to rotate the rotor. TL
) In order to act as a, an alternating voltage must be generated in the ultrasonic vibrator when the rotor is rotated in one direction, similar to a motor generator that uses electromagnetic interaction using a coil. . However, in order to generate AC voltage in the piezoelectric vibrator, ultrasonic vibrations with a high natural frequency determined by the ultrasonic vibrator must be generated, and such ultrasonic waves are generated from the low speed rotation of the rotor in one direction. Words that cause vibrations are difficult.

In other words, when the rotor is rotated in one direction, the end face of the stator that is crimped simply tries to rotate together with the rotor, and no ultrasonic vibration is generated, and the rotation of this end face of the stator is at its limit. When this happens, slippage will occur between this end face and the rotor, resulting in wear.

Of course, if the rotor is vibrated in its circumferential direction, ultrasonic vibrations will occur, but this is not a reverse effect of the electric action that rotates the rotor.

Therefore, in order to stop the rotation of the rotor connected to the mechanical system, we stop supplying AC voltage to the piezoelectric vibrator. In order to consume the rotational energy of this mechanical system, it is necessary to due to friction with the stator,
Therefore, these wears are unavoidable. This wear rate increases as the inertia of the mechanical system increases.

An object of the present invention is to provide an ultrasonic motor generator that utilizes the reversible function of a piezoelectric vibrator to enable mutual exchange of electrical energy and mechanical energy.

c. Means for Solving Problems] In order to achieve the above object, the present invention provides an ultrasonic ellipse comprising a piezoelectric longitudinal vibrator to which an alternating current voltage is applied and a piezoelectric torsional vibrator to which an electric system is connected. A rotor connected to a mechanical system is crimped onto a stator consisting of a vibrator, and the electric system or the mechanical system generates ultrasonic torsional vibration in the piezoelectric torsional vibrator and at the same time generates a vertical piezoelectric vibrator. It vibrates electrically, and its pumping action enables mutual conversion between the electrical energy of the electrical system and the rotational energy of the mechanical system.

[Effect]

When an alternating current voltage is applied to the piezoelectric vertical vibrator, longitudinal vibration occurs on the end face of the stator. Although the amplitude of this longitudinal vibration is very small, its acceleration is extremely large. In the extension phase of this longitudinal vibration, the end face of the stator is pressed against the rotor and the stator cannot extend. However, in the contraction phase of longitudinal vibration, the stator contracts with a large acceleration, so the rotor cannot follow this contraction, and the rotor ends up floating above the end face of the stator.

In other words, due to the ultrasonic longitudinal vibration generated in the piezoelectric longitudinal vibrator,
The end face of the stator generates longitudinal vibration, and the rotor is pressed against the end face of the stator and the rotor is lifted from the end face of the stator every cycle. In this case, when the rotor is pressed against the end face of the stator, a strong frictional force is generated between the two.

With an AC voltage applied to the piezoelectric longitudinal vibrator in this way, if an AC voltage with the same frequency and a predetermined phase as this AC voltage is applied from the electrical system to the piezoelectric torsion vibrator, ultrasonic torsional vibration will be generated in the piezoelectric torsion vibrator. occurs, and the stator end face undergoes torsional vibration around its central axis.The composite vibration of this torsional vibration and the previous longitudinal vibration is elliptical vibration, but the longitudinal vibration is in the extension phase and the stator end face is pressed against the rotor. During this time, the stator end face rotates due to torsional vibration, and the rotor also rotates accordingly. In the next contraction phase of longitudinal vibration, the rotor rises from the end face of the stator, and the rotor continues to rotate due to inertia, but the stator is released from the twisted state by torsional vibration and returns to its original state. This operation is performed for each period of vertical and torsional vibration, and thus the rotor rotates. This is the electric action of the present invention.

In addition, when the rotor is rotated by the rotational energy of the mechanical system while an AC voltage is applied to the piezoelectric vertical vibrator, when the stator end face is pressed against the rotor in the extension phase of the longitudinal vibration, the stator rotates as the rotor rotates. The end face rotates, causing twisting in the stator. In the next contraction phase of the longitudinal vibration, the rotor rises from the end face of the stator, so the stator is released from the twisted state caused by the rotation of the rotor and returns to its original state. This operation is performed for each period of longitudinal vibration, and therefore ultrasonic torsional vibration is generated in the stator. This ultrasonic torsional vibration is transmitted to the piezoelectric torsional vibrator, which generates an alternating current voltage. This is the power generation effect of the present invention.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a configuration diagram showing an embodiment of an ultrasonic motor generator according to the present invention, where ■ is a stator, 2°3 is a piezoelectric torsional vibrator, 4 is a piezoelectric longitudinal vibrator, and 5 to 10 are piezoelectric bodies. Motoko, 11
~13 is an electrode, 14-17 is an ultrasonic vibrator, 18.19
20 is an AC voltage source, 21 is an electric system, 22 is a rotor, 23 is a shaft, and 24 is a mechanical system.

In the figure, the piezoelectric torsion vibrator 2 includes one ring-shaped electrode 11 and 2° ring-shaped piezoelectric elements 5.
6 are integrated. These piezoelectric elements5.
6 are arranged so that twisting deformation occurs in the circumferential direction due to voltage application, and twisting deformation occurs in mutually opposite directions as shown by arrows.

The piezoelectric torsional vibrator 3 also has a similar configuration. Further, the piezoelectric vertical vibrator 4 is formed by integrating a ring-shaped electrode 12 and two ring-shaped piezoelectric elements 7 and 8 sandwiching the ring-shaped electrode 12. These piezoelectric elements are arranged so that expansion and contraction deformation occurs in the thickness direction when a voltage is applied, and expansion and contraction deformation occur in mutually opposite directions as shown by arrows. That is, the piezoelectric elements 5 and 6 and the piezoelectric elements 7 and 8 are arranged so that their polarization directions are opposite to each other.

The ultrasonic vibrators 14 to 17 are cylindrical and made of aluminum or the like.

- These piezoelectric torsional vibrators 2.3, piezoelectric longitudinal vibrators 4, and ultrasonic vibrators 14 to 17 are arranged so that their central axes coincide with each other. 15 - piezoelectric longitudinal vibrator 4 - ultrasonic vibrator 16 - piezoelectric torsional vibrator 3 - ultrasonic vibrator 17 are stacked in this order and integrated to form an ultrasonic vibrator as stator 1.

Each electrode 1 of the piezoelectric torsional vibrator 2.3 and the piezoelectric longitudinal vibrator 4
Terminals 18 and 19 are taken out from 1.12, and the ultrasonic vibrators 14 to 17 are electrically connected to each other and grounded together. The terminal 18 is connected to the electrical system 2, which will be described later.
1 is connected. An alternating current voltage source 20 is connected to the terminal 19, and an alternating current voltage (2) is applied to each piezoelectric element 7.8 of the piezoelectric longitudinal vibrator 4 via the electrode 12. This results in
The piezoelectric elements 7.8 expand and contract in the same phase, and the thickness of the piezoelectric longitudinal vibrator 4 expands and contracts to generate ultrasonic longitudinal vibrations.

Here, when the frequency of the applied AC voltage (■) is made to match the natural frequency of the ultrasonic vibrators 14 to 17, the ultrasonic vibrators 14 to 17 enter a resonant state, and this ultrasonic longitudinal vibration 15, it is propagated to the ultrasonic vibrator 14 via the piezoelectric torsional vibrator 2, and similarly, it is propagated to the ultrasonic vibrator 17 via the ultrasonic vibrator 16 and the piezoelectric torsional vibrator 3.

Therefore, the natural frequency of the ultrasonic vibrators 14 to 17 is f'
Q. If the wavelength is λ, by setting the distance MH from the piezoelectric longitudinal vibrator 4 to the end face (that is, the stator end face) 14a of the ultrasonic vibrating body 14 to λ/4, the stator end face 14a is It will be located in the vibration. For this reason, the stator end face 14a vibrates in a direction parallel to the central axis of the stator l (that is, in the vertical direction), but the end face 17a of the ultrasonic vibrator 17 is fixed, and the stator 1 is If the electrode 12 is configured symmetrically,
Since the ultrasonic longitudinal vibrations propagated from the piezoelectric longitudinal vibrator 4 to the ultrasonic vibrator 14 and the ultrasonic longitudinal vibrations propagated to the ultrasonic vibrator 17 are in phase, the longitudinal vibrations due to these are transmitted to the stator end face 14a. This appears as an addition, and therefore, this stator end face 14a undergoes a large vertical vibration.

The rotor 22 is crimped onto the stator end face 14a with a predetermined crimping force. This crimping method may be achieved, for example, by inserting a bolt through the center hole of the stator 1 and thereby tightening the rotor 22 to the stator end face 14a. A shaft 23 is integrally provided with the rotor 22, and a mechanical system 24 is connected to this shaft 23.

In this way, while the rotor 22 is crimped to the stator l, an AC voltage (2) with a frequency of 1, which is equal to the natural frequency f0 of the ultrasonic vibrators 14 to 17, is applied from the AC voltage source 20 to the piezoelectric vertical vibrator 4. When applied, ultrasonic longitudinal vibration occurs in the piezoelectric longitudinal vibrator 4, and the stator end face 14a longitudinally vibrates. The amplitude of this vibration is very small, about ±1 μm, but the acceleration is extremely large, about 104 times the acceleration of gravity g. Therefore, when the ultrasonic longitudinal vibration is in the extension phase in which the stake 1 is extended, the stator end face 14a is pressed against the rotor 22, and the extension of the stake 1 is prevented, but in the contraction phase in which the ultrasonic longitudinal vibration is in the contraction phase in which the stator 1 is contracted. When , the stator end face 14
Since the acceleration of the vibration of a is very large, the rotor 22 cannot follow the contraction of the stator 1, and the rotor 22 is in a state of floating above the stator end surface L4a. This state of the rotor 22 is carried out every cycle of ultrasonic longitudinal vibration (therefore, one cycle of the AC voltage V applied to the piezoelectric longitudinal vibrator 4), and therefore the rotor 22 is crimped against the stator end face 14a. Repeat surfacing.

Therefore, when the rotor 22 is not provided, the stator end face 14a performs sinusoidal longitudinal vibration over time due to ultrasonic longitudinal vibration, but as described above, the rotor 22
By being crimped, the stator end face 14a is displaced only when the piezoelectric longitudinal vibrator 4 contracts, and therefore the stator end face 14a performs longitudinal vibration as if the longitudinal vibration of the sine wave was half-wave rectified. Note that the pressing force No of the rotor 22 against the stator 1 at this time is expressed as follows.

However, e33: 18.6N/VmR: Radius of piezoelectric element 7.8 Vrms: Effective value of AC voltage from AC voltage source 20 = Thickness of piezoelectric element 7.8 Also, when rotor 22 is crimped Assuming that the longitudinal vibration of the stator end face 14a when the stator is not in use is a=a and sinωt, the amplitude a0 is as follows.

Cρfo L However, C: Propagation speed of ultrasonic longitudinal vibration in the ultrasonic vibrators 14 to 17 ρ: Density of the ultrasonic vibrators 14 to 17 Further, H=λ/4 and C=λ". Since the frequency f of the applied voltage from the AC voltage source 21 is equal to the natural frequency ".," H-□... (3)
It becomes f.

In this configuration, the electric system 21 is used as an AC voltage supply source, and by supplying AC voltage V' to the piezoelectric torsional vibrator 2, the rotor 22 rotates and operates as an electric motor. This will be explained below with reference to FIG. In addition, in the same figure, 25 and 26 are changeover switches, 27 to 30 are resistors,
31 is an AC voltage source, and parts corresponding to those in FIG. 1 are given the same reference numerals. Furthermore, in the figure, the piezoelectric torsional vibrator 2.3 and the piezoelectric longitudinal vibrator 4 are schematically illustrated.

When the embodiment shown in FIG. 1 is operated as a motor, the electric system 21 serves as means for supplying alternating current voltage to the piezoelectric torsion vibrator 2. FIG. 2 shows a specific example of this electrical system 21, in which selector switches 25, 26, resistors 2
7 to 30 and an AC voltage source 31. The changeover switch 25 is closed to the A side when rotating the rotor 22, and closed to the A2 side when the rotor 22 is stopped. resistance 2
7 is a braking resistor. Further, the changeover switch 26 is used to select the resistors 28 to 30 in parallel relationship, and the AC voltage generated by the AC voltage source 31 is transferred to the changeover switch 26.
The voltage is applied to the piezoelectric torsional vibrator 2 through any of the resistors 28 to 30 selected in the above.

The resistors 28 to 30 define the rotation speed of the rotor 22.

In order to rotate the rotor 22, set the changeover switch 25 to the A1 side, and turn the changeover switch 26 to aI+aZ=”
An alternating current voltage v' is applied to the piezoelectric torsion vibrator 2 between each of the three sides. Therefore, as explained earlier, the piezoelectric longitudinal vibrator 4 generates ultrasonic longitudinal vibration, but at the same time, the piezoelectric torsion vibrator 2 generates an ultrasonic wave that twists the stator 1 about the central axis of the stator 1. Causes torsional vibration.

That is, as shown in FIG. 1, the piezoelectric torsional vibrator 2 consists of two ring-shaped piezoelectric elements 5.6 and a ring-shaped electrode ll sandwiched between them.
When an alternating current voltage is applied to the piezoelectric element 5.6, the piezoelectric element 5.6 undergoes twisting deformation in the circumferential direction about its central axis. The amount of torsional deformation changes with the frequency of the alternating current voltage V', but the piezoelectric elements 5 and 6 are arranged so that their deformation directions are opposite to each other, and the end face of the ultrasonic vibrator 17 is 17a is fixed, the piezoelectric element 6 is twisted such that its end face on the ultrasonic vibrating body 15 side is fixed and its end face on the electrode 11 side is displaced in the circumferential direction. Moreover, the piezoelectric element 5
The twisting direction of is opposite to the twisting direction of the piezoelectric element 6, but
Since one end face of the piezoelectric element 5 is fixed via the electrode 11 to the end face where the piezoelectric element 5 is twisted, as the piezoelectric element 5 is twisted, a reaction force causes the superposition of the piezoelectric element 5 to The end face of the acoustic wave vibrator 14 is twisted in the same direction as the piezoelectric element 6 with respect to the electrode 11 . From the above, by applying the AC voltage v', the ultrasonic vibrator 1 of the piezoelectric torsional vibrator 2
The fourth side end face is displaced in the circumferential direction, and the amount of displacement changes moment by moment depending on the frequency of the applied alternating current voltage V'.

As a result, ultrasonic torsional vibration is generated from the piezoelectric torsional vibrator 2 and propagated to the stator end face 14a via the ultrasonic vibrator 14, and the stator end face 14a is displaced (i.e., rotated) in the circumferential direction about its central axis. .

Note that the other piezoelectric torsional vibrator 3 does not necessarily have to be provided. However, by providing this, as explained earlier, the stator l can be connected to the piezoelectric longitudinal vibrator 4.
Furthermore, the torsional vibration at the stator end face 14a can be made larger than in the case where only the piezoelectric torsional vibrator 2 is provided. In other words, when only the piezoelectric torsional vibrator 2 is provided, the piezoelectric torsional vibrator and the stator end surface 14a torsionally vibrate in opposite directions with respect to the middle between the piezoelectric torsional vibrator 2 and the stator end surface 14a. Two piezoelectric elements 9, 1 with different
When a piezoelectric torsion vibrator 3 in which the voltage 0 is arranged opposite to the piezoelectric torsion vibrator 2 is added, and the same AC voltage as that of the piezoelectric torsion vibrator 2 is applied to it, the piezoelectric longitudinal vibrator 4 becomes piezoelectric. The torsional oscillators 2.3 generate torsional vibrations in mutually opposite directions, and the amplitude of the torsional vibration of the stator end face 14a, which is further away from the piezoelectric longitudinal oscillator 4 than the piezoelectric torsional oscillator 2, becomes larger.

Therefore, in FIG. 2, the stator end face 14a is connected to the ultrasonic longitudinal vibration from the piezoelectric longitudinal vibrator 4 and the piezoelectric torsional vibrator 2.3.
Due to the ultrasonic torsional vibration from , vertical vibration and torsional vibration are performed at the same time, and overall, these combined vibrations are performed. Here, if the ultrasonic longitudinal vibration and the ultrasonic torsional vibration have the same frequency but a phase difference of 90'', elliptic vibration occurs.

Hereinafter, ultrasonic longitudinal vibrations are generated from the piezoelectric longitudinal vibrator 4 and the piezoelectric torsional vibrator 2, respectively, so that the stator end surface 14a vibrates elliptically.
Ultrasonic torsional vibration is generated, but in this case,
In other words, ultrasonic elliptical vibration is applied to this stator end face 14a. In addition, the frequency and phase of the ultrasonic torsional vibration are determined by the AC voltage V applied to the piezoelectric torsional vibration J element 2.
′ frequency and phase match. Therefore, the AC voltage {circle around (2)} applied to the piezoelectric torsional vibrator 2 has the same frequency and is out of phase by 90'' with respect to the AC voltage {circle over (2)} applied to the piezoelectric longitudinal vibrator 4.

Here, the ultrasonic torsional vibration is b=b, )cosωt,
Assuming that the effective value of the AC voltage V' is V'rms and the propagation speed of the ultrasonic torsional vibration in the ultrasonic torsional vibrator 14 is C1, the following equation is obtained. Therefore, from equations (2) and (4) above,
When the rotor 22 is not crimped to the stator 1,
The end face 14a is subjected to ultrasonic elliptic vibration whose ellipticity δ is expressed by the following equation (5).

・・・・・・・・・・・・(5) However, the right side of equation (5) when Vrms=V'rms is δ. Then, the ellipticity δ is set as follows.

δ. −0,26°≦δ≦δ. +0.26° In order to cause the stator end face 14a to torsionally vibrate with maximum amplitude in response to ultrasonic torsional vibration, the piezoelectric torsional vibrator 2 is adjusted so that the stator end face 14a is located at the antinode of this ultrasonic torsional vibration. Set the position.

Therefore, if the wavelength of ultrasonic torsional vibration at the ultrasonic vibrator 14 is λ', then the distance h (Fig. 1) from the piezoelectric torsional vibrator 2 to the end surface 14a of the ultrasonic vibrator 14 is λ'/4. , and C,=λ'f, so r. Here, if the ultrasonic vibrators 14 to 17 are aluminum cylinders, C=5000 m/sec.

Since Cs = 3040m/sec, the above (3
), (by formula 63, H>h ・・・・・・・・・・・・−(7
).

Next, the rotation of the rotor 22 due to the elliptical vibration of the end surface 14a of the ultrasonic vibrator 14 will be explained.

First, in FIG. 3, if the plane including the stator end face 14a when no ultrasonic longitudinal vibration or ultrasonic torsional vibration is applied is the reference plane 32, then when ultrasonic elliptical vibration due to these ultrasonic vibrations is applied, , this stator end face 1
4a vibrates elliptically with an ellipticity δ expressed by the above equation (5). FIG. 3(a) shows a point P on this stator end face 14a.
It vibrates in an elliptical trajectory as shown by the dashed arrow.

FIG. 3(b) shows a state in which the rotor 22 is pressed onto the stator 1. Although the stator end surface 14a moves up and down with respect to the reference surface 32 due to ultrasonic longitudinal vibration, the rotor 22 is crimped to the stator l so as to prevent the stator end surface 14a from moving upward from the reference surface 32. Therefore, the stator end face 14
Looking at the displacement of a certain point P on a, this point P is within the reference plane 32 during the half period in which the ultrasonic longitudinal vibration attempts to lift the stator end face 14a above the reference plane 32. However, in this half cycle, the stator end face 14a is displaced in a certain direction due to the ultrasonic torsional vibration, and therefore the point P is displaced on the reference plane 32 as indicated by the broken line arrow. In the remaining half period of the ultrasonic longitudinal vibration, the stator end face 14a descends from the reference plane 32, and therefore, the point P, as shown by the dashed arrow,
It is displaced along the trajectory of half the ellipse.

Therefore, the ultrasonic longitudinal vibration moves the stator end face 14a to the reference plane 3.
2, the rotor 22 is pressed against the stator end surface 14a, and due to the frictional force between them,
As shown in FIG. 4(a), the rotor 22 is displaced together with the end surface 14a in the direction of the arrow. This displacement is the ultrasonic vibrator 1
The rotational force is applied to the rotor 22 in the circumferential direction with respect to the central axis of the rotor 22 .

Next, in the next half cycle of the ultrasonic longitudinal vibration, the stator end face 14a
falls from the reference plane 32, but the rotor 22 cannot follow this. For this reason, as shown in FIG. 4(b), the rotor 22 is in a state of floating above the stator end face 14a, and attempts to rotate in the same direction as in the case of FIG. 4(a).

Also, at this time, the ultrasonic torsional vibration is caused by the stator end face 14a.
is displaced in the opposite direction (arrow). Then, in the next half cycle of the ultrasonic longitudinal vibration, the stator end face 14a rises again and presses against the rotor 22, resulting in the state shown in FIG. 4(a).

In this way, the states shown in FIGS. 4(a) and 4(b) are reversed every cycle of ultrasonic vibration, and the rotor 22 rotates in a constant direction. The pressing force against the rotor 22 at this time is NO shown in the above equation (1).

Incidentally, the larger the amplitude b0 of the ultrasonic torsional vibration, the larger the rotation angle of the rotor 22 in one period. Therefore, from the above equation (4), the larger the effective value V'r+ss of the AC voltage v' applied to the ultrasonic torsional transducer 2, the larger the rotation speed n of the rotor 22. By the way, the effective value V
The maximum rotational speed n0 for 'rmS is expressed as follows.

πzC1ρR・l ・・・・・・・・・・・・ (8) This maximum rotation speed n0 means that when the ultrasonic longitudinal vibration is in the extension phase, the stator end face 14a rotates in one direction due to the ultrasonic torsional vibration, The rotation speed when the phase difference between the ultrasonic longitudinal vibration and the ultrasonic torsional vibration is exactly 90° so that the stator end face 14a rotates in the opposite direction due to the ultrasonic torsional vibration when the ultrasonic longitudinal vibration is in the contraction phase. It is. However, if the phase difference between these ultrasonic vibrations and ultrasonic torsional vibrations is made to differ by more than 90 degrees, as shown in FIG.
a has a tilted elliptical vibration, so in the case of the same figure,
It attempts to rotate slightly in the opposite direction during the extension phase of the ultrasonic longitudinal vibration, and then rotates in the desired direction. As a result, the rotation speed n of the rotor 22 is 00 as expressed by the above equation (8).
becomes smaller than

The slope of the elliptical vibration shown in FIG. 5 differs depending on the phase difference between the ultrasonic longitudinal vibration and the ultrasonic torsional vibration. Therefore, as shown in FIG. 2, since the piezoelectric vibrator electrically acts as a capacitor, by selecting the resistors 28 to 30 with the changeover switch 26, the phase of the AC voltage V' changes and the piezoelectric twisting occurs. The phase of the vibration also changes, and as a result, the rotation speed of the rotor 22 can be changed.

Furthermore, when the phase of the alternating current voltage V' applied to the ultrasonic torsion transducer 2 is reversed, the direction of the elliptical orbit indicated by the broken line arrow in FIG. 3 is reversed, and therefore the rotational direction of the rotor 22 is reversed.

The above is an explanation of the electric operation of the embodiment shown in FIG.

Next, the power generation effect will be explained with reference to FIG. In this figure, parts corresponding to those in FIG. 1 are given the same reference numerals.

In FIG. 6, the machine+d system 24 in this case is one that generates mechanical energy, such as a water wheel.
As a result, the rotor 22 is rotationally driven. Additionally, the electrical system 21 is any load that consumes the power generated in this embodiment.

In this case as well, the AC voltage V is applied from the AC voltage source 20 to the ultrasonic longitudinal vibrator 4, so that ultrasonic longitudinal vibrations are generated. The rotor 22 is connected to the stator 1 in FIG.
As explained in FIG. 4, the rotor 22 is crimped against the stator end face 14a and floats repeatedly due to the ultrasonic longitudinal vibration, as explained earlier. ing.

Now, looking at the state in which the rotor 22 is crimped to the stator end face 14a, as shown in FIG. 7(a),
Due to the pressing force applied to the rotor 22 and the frictional force between the rotor 22 and the stator end surface 14a, as the rotor 22 rotates in the direction of the arrow, the stator end surface 14a also rotates in the same direction. As a result, in FIG. 6, the ultrasonic torsion transducer 2 is twisted with respect to the end surface on the side of the ultrasonic vibrator 15.

For this reason, in FIG. 1, the piezoelectric elements 5 and 6 are twisted to the same extent and in the same direction. Since this twisting direction coincides with the polarization direction of the piezoelectric elements 5 and 6, a voltage is generated in each piezoelectric element 5 and 6 in a direction corresponding to the polarization direction and the twisting direction, but these polarization directions are opposite to each other. Therefore, the potentials of the surface of the electrode 11 on the piezoelectric element 5 side and the surface on the piezoelectric element 6 side due to these voltages are equal. Therefore, the voltage E is output from the piezoelectric torsional vibrator 2. In this case, the value of the voltage generated in the piezoelectric elements 5 and 6 increases depending on the amount of twisting of the piezoelectric elements 5 and 6 as the rotor 22 rotates.

Next, when the ultrasonic longitudinal vibration is in the contraction phase, the stator end face 1
4a descends from the reference surface 32, as shown in FIG. 7(b), the rotor 22 floats above the stator end surface 14a, and the stake end surface 14a becomes released from the rotor 22, causing twisting. to return to the original state. As a result, the voltage generated in the piezoelectric element 5.6 is attenuated. Then, when the stator end face 14a rises due to the ultrasonic longitudinal vibration and is pressed against the rotor 22 again, a voltage is generated in the piezoelectric torsional vibrator 2 due to the rotation of the rotor 22.

In this way, the voltage output from the piezoelectric torsional oscillator 2 changes by one period for each period of ultrasonic longitudinal vibration, and therefore, from this piezoelectric torsional oscillator 2, the ultrasonic wave generated in the piezoelectric longitudinal oscillator 4 Because of the vibration of the acoustic longitudinal vibration, an alternating current voltage E having the same frequency and synchronized in phase can be obtained. This AC voltage E is continuously obtained as long as the rotor 22 is rotated by the mechanical system 24.

The relationship between the torsional vibration of the piezoelectric element and the induced voltage is reversible. Therefore, when the rotational speed of the rotor 22 is 00, the effective value of the AC voltage E output from the piezoelectric longitudinal vibrator 2 is as described above. It is equal to V'rms obtained from equation (8).

The above is the power generation effect of the embodiment shown in FIG.

High frequency power can also be generated if the mechanical system 24 is, for example, a DC motor or a commercial AC motor.

By the way, since this embodiment has a power generation function, in FIG.
0, apply AC voltage ■, close the changeover switch 25 to the A1 side, apply AC voltage V' to the piezoelectric torsional vibrator 2 to rotate the rotor 22, and then turn the changeover switch 25
is switched to the A2 side and the AC voltage V' to the piezoelectric torsional vibrator 2 is changed.
When the stator l is cut off, the stator end face 14a performs only longitudinal vibration, and the stator l does not generate any rotational force to the rotor 22.

However, the rotor 22 attempts to maintain its rotating state due to the inertia of the mechanical system 24. This state is exactly the same as the state in which power generation is performed as explained in FIGS. 6 and 7.

Therefore, the piezoelectric torsional vibrator 2 generates alternating current power, which is supplied to the resistor 27 via the changeover switch 25 and is consumed as Joule heat in the resistor 27.

That is, the rotational energy of the mechanical system is converted into electrical energy and consumed by the resistor 27, and by appropriately setting the resistance value of the resistor 27, the rotor 22 is
It can be stopped quickly without causing a slip with 4a.

Furthermore, while the rotor 22 is being driven to rotate, the load on the rotor 22 (mechanical system 24) may vary. Now rotor 2
If the load No. 2 is reduced, the rotational energy for this load increases and becomes larger than the rotational energy commensurate with the electrical energy supplied from the electrical system 21. This means that the rotational energy is equivalently larger than the electrical energy, and the rotational speed of the rotor 22 increases. Then, due to the increase in the rotational speed of the rotor 22, the stator end face 14a is twisted more than the twist caused by the ultrasonic torsional vibration generated by the AC voltage V', and ultrasonic torsional vibration is generated in the stator l by the amount of this twist. As a result, electrical energy is generated in the piezoelectric torsional vibrator 2, which is consumed by the electrical system 21, and the rotation speed of the rotor 22 decreases.

Conversely, the load on the rotor 22 increases, equivalently increasing the load on the mechanical system 24.
When the rotational energy of the rotor 22 becomes smaller than the electrical energy, the rotational speed of the rotor 22 becomes lower than the rotational speed that should be generated by the ultrasonic torsional vibration generated by the supplied electrical energy. For this reason, the rotation of the rotor 22 limits the torsional vibration of the stator end face 14a, but the current from the electrical system 21 increases to compensate for this. As a result, the rotation speed of the rotor 22 increases.

In this way, the rotor 22 is always maintained in a stable rotating state.

〔Effect of the invention〕

As explained above, according to the present invention, ultrasonic torsional vibration is caused in a piezoelectric torsional vibrator by electric energy,
In combination with ultrasonic longitudinal vibration, the rotor can be rotated, and the rotation of the rotor can generate ultrasonic torsional vibration, which can generate electrical energy in the piezoelectric torsional vibrator, and the structure is simple, small, and inexpensive. An ultrasonic motor generator can be provided.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the ultrasonic motor generator according to the present invention, Fig. 2 is a block diagram showing the electric operation of this embodiment, and Fig. 3 is a stator to which the rotor in Fig. 2 is crimped. FIG. 4 is an explanatory diagram showing the vibration of the end surface of the stator, FIG. 4 is an explanatory diagram showing the rotational movement of the rotor due to the vibration of the stator end surface, FIG. 5 is an explanatory diagram of the speed change action of the embodiment shown in FIG. 1, and FIG. FIG. 1 is a block diagram showing the power generation action of the embodiment shown in FIG. 1, and FIG. 7 is an explanatory diagram showing the process of generating torsional vibration of the stator due to rotation of the rotor in FIG. 5. 1... Stator (ultrasonic vibrator), 2...
...Piezoelectric torsional vibrator, 4...Piezoelectric longitudinal vibrator, 1
4-17... Ultrasonic vibrator, 20...
AC voltage source, 21...Electrical system, 22...
・Rotor, 24... Mechanical system. Figure 1\17a Figure 2 Figure 3 tσノ
(b)(a)
Figure 4 (b) Figure 5 Figure 6

Claims (4)

[Claims] (1) A rotor to which a mechanical system is connected is crimped to a stator consisting of an ultrasonic vibrator equipped with a piezoelectric longitudinal vibrator to which an AC voltage is applied and a piezoelectric torsional vibrator to which an electrical system is connected, and the rotor to which the mechanical system is connected is crimped. to generate ultrasonic longitudinal vibration in the piezoelectric longitudinal vibrator, and to generate ultrasonic torsional vibration in the piezoelectric torsional vibrator by the electric system or the mechanical system, and to combine the electric energy of the electric system with the electric energy of the electric system. An ultrasonic motor generator characterized by being configured to enable mutual conversion with rotational energy of a mechanical system. (2) In claim (1), the electrical system is an alternating current voltage supply source, and when the rotational energy of the mechanical system is smaller than the electrical energy of the electrical system, The piezoelectric torsional vibrator generates ultrasonic torsional vibration due to the applied alternating current voltage, the rotor rotates due to the combined vibration of the ultrasonic torsional vibration and the ultrasonic longitudinal vibration, and the rotational energy is transferred to the When the electric energy is larger than the electric energy, as the rotor rotates, an ultrasonic torsional vibration that is greater than the ultrasonic torsional vibration caused by the application of the AC voltage from the AC voltage source is generated in the piezoelectric torsional vibrator. An ultrasonic motor generator characterized in that a voltage is generated in a piezoelectric torsion vibrator to enable power generation. (3) In claim (2), the alternating current voltages applied to the piezoelectric longitudinal vibrator and the piezoelectric torsional vibrator have the same frequency, and the composite vibration has an ellipticity δ of δ_o −0.2δ_o≦δ≦δ_o+0.2δ_o However, δ_o=bo/ao=8/π・C_s/C・μao: Amplitude of ultrasonic longitudinal vibration bo: Amplitude of ultrasonic torsional vibration C_s: Propagation speed of ultrasonic torsional vibration C: Propagation speed of ultrasonic longitudinal vibration in ultrasonic vibrator μ: Ultrasonic elliptical vibration with friction coefficient on the crimped surface of rotor and stator. Generator. (4) In claim (1), the mechanical system is a drive device that rotates the rotor, and the rotation of the rotor causes ultrasonic torsional vibration in the piezoelectric torsional vibrator. An ultrasonic motor generator, wherein the electric power generated in the piezoelectric torsional vibrator can be transmitted to the electric system.