JPS60183982A - piezoelectric motor - Google Patents

Abstract

PURPOSE:To improve the responsiveness with a simple structure by composing a stator of two piezoelectric vibrators divided suitably, and contacting a slider through a vibration transmitting member with the stator. CONSTITUTION:A piezoelectric motor has two piezoelectric vibrators 5, 6 at a stator. The vibrators 5, 6 are divided at least into a pair of ranges that the directions of the polarization are alternately inverted in the moving direction of the slider. The vibrator 5 is superposed and mounted on a stator base 7. A projection 8 and a shaft 9 of vibration transmitting members are formed on the surface of the base 7. A slider is contacted with the projection 8.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a motor that generates driving force using a piezoelectric material.

Conventional configurations and their problems In recent years, piezoelectric motors, which obtain rotational or running motion by exciting various ultrasonic vibrations using electromechanical transducers such as piezoelectric ceramics, have attracted attention because they have a high energy density. Conventional piezoelectric motors that utilize these ultrasonic vibrations will be described below with reference to the drawings.

FIG. 1 is an example of a conventional piezoelectric motor published in Nikkei Mechanical (58, 2, 28), in which a piezoelectric element ring 2 is bonded to the surface of a 91JI ring 1 and integrated. As shown in FIG.
The area is divided into 17 areas according to a division ratio of -', and electrodes are attached and polarized. The directions of polarization are opposite in adjacent regions. Thereafter, the surface of the piezoelectric confectionery is covered with conductive paint and the electrodes are combined into two as shown by diagonal lines. E is a ground terminal.

A moving body 4 to which a slider 3 is fixed is located above the elastic ring 1.

The operation of the conventional piezoelectric motor configured as described above will be described above. The voltage on one side of the piezoelectric element 2 (V sin ωt on the electrode A, and ■ on the other electrode B).

AC signals of CO3oi t are respectively applied. Then, the divided areas alternately expand and contract in the circumferential direction, and elastic ring 1
Bending motion occurs. Figure 3 is an enlarged depiction of the contact situation between a moving body and an elastic body, which is well known as the elliptical motion of particles associated with surface waves (for example, see Nobuo Mikoshiba, 1. Sound wave physics, published by Sanseidosha in 1972). ) If we focus on one point (c) on the surface of the elastic body, point 4 has the major axis 2W and the minor axis 2.
It draws an elliptical trajectory of u. At the vertex where the elastic body contacts the moving body, point 4 has a velocity of -2πfu in the negative direction of the X axis.

As a result, the moving body is driven at a speed V in the direction opposite to the wave propagation due to the frictional force with the elastic body. In order to draw an elliptical locus as a thrust on the surface of an elastic body in this way, it is possible to use Rayleigh waves of surface acoustic waves or bending vibration of the elastic body. For example, the wavelength of surface acoustic waves is as long as 1oCIn, and when the bending vibration of an elastic body is used, the wavelength can be reduced to several tnm.
, the number of vertices that serve as contact points can be increased to several. The driving principle of Rayleigh waves, which are surface acoustic waves, is realized by propagating waves using bending vibrations in a partial region of an elastic body, and creating an elliptical trajectory on the surface of the elastic body. In this surface wave type piezoelectric motor, the top of the wave, which is the contact point, is always in contact with the moving object, so the speed of the moving object is equal to the top speed. Moreover, the magnitude of the output torque is based on the contact area, the load, and the friction coefficient of the contact portion. In addition, this piezoelectric motor is a two-phase
A power supply with a phase shift based on the same principle as a three-phase motor (allows the direction of rotation to be switched more easily.

However, the above configuration has the following drawbacks.

(1) Energy is consumed to repeatedly bend an elastic body with a large Young's modulus, which induces heat generation, resulting in extremely poor linearity.

(2) In addition, in order to extract thrust from a very small amplitude of approximately 0.25 μm or less, the moving object uniformly contacts the peaks and troughs of the stator with different amplitudes, and the speed of the moving object is determined by the integral The speed is low due to the wrong value. Therefore, in order to obtain a practical rotation speed, torque, etc., a large amount of electric power, about 10 to 100 times that of a conventional motor, is required.

(3) The vibration amplitude when the piezoelectric motor is actually driven, which still has a surface waveform, has a maximum vertical component of about 0.5 μm and a horizontal component of thrust of about 0.25 μm, which is the vibration required for thrust. Compared to the generated energy, the ineffective energy is consumed more than twice, resulting in an extremely inefficient structure.

(4) The conventional piezoelectric motor with a surface waveform described above has two sets of drive electrodes, and waves excited by the A electrode are propagated to the B electrode, or conversely, waves excited by the B electrode are propagated to the A electrode. It is propagated as a wave with longitudinal and transverse components, generating an elliptical trajectory on the surface of the elastic body. Due to this driving principle, the effective driving area is always as low as 50%.

(5) Therefore, the elastic ring becomes an infinitely free oscillating system,
Unnecessary higher-order modes in the ring plane are excited at the same time, becoming a source of harsh audible noise.

(6) Since the structure of the surface wave device is still used as the driving principle, the stator has no choice but to have an endless configuration, and the -second-order effect is generated by exciting the -order amplitude and then using the second-order amplitude. It has a configuration with an extremely narrow cutting range that is reluctant to use.

In other words, it is impossible to use the direct and powerful thrust of a disk or rectangular plate due to space waves or bulk waves.

(7) Also, half of the total area always functions as a forcedly excited oscillator, but the other area is open as an infinitely free oscillating system, so the vertical distortion is noticeable especially under heavy loads at the level of actual driving. The distribution becomes uneven, resulting in uneven rotation.

(8) In addition, in this piezoelectric motor, energy is transferred through vibrational contact between the steering wheel and the rotor, and the characteristics of the material used for the contact surface are (a) direct motor life, (1)
) It has an effect on l-lux characteristics, (C) rotational speed, or (d) power efficiency, etc., and in actual driving at a practical word output characteristic level, the usable range is several hours or more. At most, it does not exceed about several hours.
It had many problems not mentioned above.

OBJECT OF THE INVENTION The purpose of the present invention is to solve the various drawbacks listed in (2) by focusing on highly efficient spatial waves or bulk waves excited by piezoelectric ceramic vibrators, and by using this as a driving force, an extremely efficient Our goal is to provide a good and practical piezoelectric motor.

Structure of the Invention The piezoelectric motor according to the present invention includes two piezoelectric vibrators and an acoustic
A stator in which two advantages and one another are overlapped in the thickness direction,
The slider is stacked on the stator in the thickness direction and is in surface contact with the stator, and has a vibration transmitting member on the surface of the stator. Both of the piezoelectric vibrators have thickness direction polarization consisting of one or more pairs of divided regions divided in the slider movement direction, and the directions of these polarizations are opposite to each other in adjacent regions. Both piezoelectric vibrators are arranged so that the vicinity of the boundary of each polarization region on one side is located near the medium temperature of each polarization region on the other side. As above/! When the piezoelectric vibrators of the i: configuration are driven with a voltage of a predetermined forced excitation frequency that is out of phase with each other, the maximum amplitude position of the combined vibration of the identifier by both piezoelectric vibrators moves in a constant direction over time. ,
The slider in contact with the apex receives a driving force in that direction.

DESCRIPTION OF EMBODIMENTS Details VC of embodiments of the present invention will be described with reference to the drawings. The stator has a structure as shown in FIG. 4, for example. On the surface of the disk-shaped first piezoelectric vibrator 5, there are eight electrodes divided into areas of 45', for example.
It is formed on the 0 surface by a method such as printing, vapor deposition, or coating. Back side: Electrode provided on (not shown)
is the first piezoelectric vibrator 6 configured as 0 or more, which may or may not be divided similarly to the above Table 1nj electrode.
Polarization is performed such that the polarization directions of adjacent electrodes are different from each other in the thickness direction. As a result, as shown in FIG. 4, four sets of forced excitation vibrators with eight poles each consisting of regions alternately having glass polarity or glass negative polarity are constructed. After polarization, the electrodes 5a do not need to be divided and are connected so that a voltage can be applied all at once. The disk-shaped second piezoelectric vibrator 6 has the same structure as the first piezoelectric vibrator 5, and includes four sets of forced excitation vibrators with eight poles each having positive or negative polarity at different pressures. .

The minimum amplitude position of the first piezoelectric vibrator 5 or the second piezoelectric vibrator 6 is near the boundary between adjacent electrodes, and the maximum amplitude position is near the center of each electrode. Both piezoelectric vibrators 5°6rrJ, the boundary between adjacent electrodes, which is the minimum amplitude position of the second piezoelectric vibrator 6, is located near the center of the electrode, which is the maximum amplitude position of the first piezoelectric vibrator 6. They are superimposed so that

The first piezoelectric vibrator 5 and the second piezoelectric vibrator 6 configured as described above are mounted on a stator base plate having a thickness equal to or about 100 times as thick as that of the piezoelectric vibrator. The stator base 7 is made of an acoustic absorbing material or friction material made of aluminum, brass, iron, stainless steel, hardened steel, synthetic resin material such as nylon, ceramic material, glass material, or a composite material made of these materials. It is formed using etc. Further, on the surface of the stator base 70,
For example, a protrusion 8 serving as a vibration transmitting member is formed near a position of about 6 mm in diameter, and a shaft 9 is formed at the center.

The structure constructed as described above is used as the stator 10 shown in FIG. As shown in FIG. 5, the output signal oscillated by the oscillator 11 at the forced excitation drive frequency determined by the stator 10 is branched, and one side is directly sent to the amplifier 12.
The other signal is input to the amplifier 14 via the phase shifter 13. The phase shifter 13 shapes a signal whose phase has been shifted within a range of +100 to +170 degrees, which is used for forward rotation or reverse rotation as will be described later. The output signal of the oscillator 11 is directly input to the amplifier 12, and the amplified signal is applied to the first piezoelectric vibrator 5 through lead wires 15 and 16. As a result, the stator 10 has 8 poles and 4 wavelengths corresponding to 4 sets of forced excitation oscillators, with a pair of regions in which the polarization directions of the first piezoelectric oscillator 5 have mutually different glass polarity or negative polarity as one wavelength. A forced excitation wave is generated. The second piezoelectric vibrator 6 is similarly driven by applying the output of the amplifier 14 via the lead wires 16,17.

Figure 6 shows the strain in the vertical direction when an electric signal is applied to the first piezoelectric vibrator 5 and the second piezoelectric vibrator 6 as a change with respect to the circumferential position at a position of about 70% of the maximum diameter. The measured results are shown. For measurement, add He-Ne to measurement piece 1.
Measurement was performed by irradiating gas laser light and using an interference method between incident light and reflected light. FIG. 6 aK shows the measurement results when the first piezoelectric vibrator 6 was driven by applying signals to the lead wires 15 and 16. When 06 ov was applied, the amplitude was about ±0.8 Br. The minimum amplitude position is near the boundary between adjacent electrodes, and the maximum amplitude position is near the center of each electrode. The results of longitudinal strain measured when the second piezoelectric vibrator 6 was driven in the same manner are shown in FIG. When SOV was applied, the amplitude was about ±0.8 μm. The minimum amplitude position is near the boundary between adjacent electrodes, and the maximum amplitude position is near the center of each electrode.

Next, the first piezoelectric vibrator 6 and the second piezoelectric vibrator 6 were simultaneously driven using the configuration shown in FIGS. 4 and 5, and the measurement results are shown in FIG. 6C. In the vertical strain distribution, a, l! : The position where the amplitude is at its maximum has moved to an intermediate position between b and b. The maximum amplitude of vertical strain is approximately 1.3
It's about twice as big. Here, as mentioned above, the second
Since the piezoelectric vibrator 6 is driven with a phase shift of +100 to ±170 degrees with respect to the first piezoelectric vibrator, the maximum amplitude position of the composite wave C moves in a constant direction with time.

A slider 18 is in contact with the top of the solid member 1o. The slider 18 is composed of an elastic body 19 made of a friction material, an elastic material, or the like, and an acoustic material 20 coupled thereto.

When the stator 1o is driven as described above, the apex of the vibration on the side of the stator 10 facing the slider 18 comes into contact with the slider 18, and the apex moves with time.
A force having a lateral component is applied to the slider 18. In this way, the slider 18 repeats positional movement by the lateral component at the driving frequency determined by the stator 1o, and as a result, it is possible to obtain a rotational movement in the range of several to several thousand revolutions per minute lff. The generated torque varies depending on the acoustic material that constitutes the stator, the friction coefficient and contact area of the slider that makes surface contact with the stator, or the magnitude of the load received, or varies from a few tens of qf-cm to several thousand qf-cm. It was possible to obtain a torque in the range of gf-σ. Regarding the direction of rotation, if the rotation obtained when driving the second piezoelectric vibrator by applying a signal whose phase is shifted in the range of +100 to +170 degrees with respect to the reference signal is, for example, positive direction rotation, then the reference signal -100 to -170 against
The direction of rotation obtained when driving by simultaneously applying signals with phase shifts in the range of 0 is rotation in the opposite direction. However, the rotation speed can be arbitrarily selected by selecting the magnitude or phase of the applied signal, or the magnitude of the load received by the contact portion.

Furthermore, according to the configuration shown in FIGS. 4 and 5, the heavy load of straining a metal having a large Young's modulus in the conventional method is eliminated. In the conventional method, the knowledge axis 2u of the elliptical trajectory
In order to increase the thickness of the metal to be bonded, it is possible to increase the thickness by further increasing the thickness of the metal.・The resonance characteristics are attenuated by about 1 sdB each time the thickness increases by 1 mm, so in reality, in order to increase the short axis 2u, which is the thrust force, driving with a large amount of power is required. In cases where the structure has extremely poor linearity/high military performance, the increase in thrust is extremely small.

FIG. 7 shows the distortion in the vertical direction of the stator 1o according to the present invention when an electric signal is applied to the stator 10', using imaginary lines.
The results are shown as changes in the cross-sectional direction. The measurement was carried out using the interferometry method using laser light, similar to the measurement in the circumferential direction. When 50V is applied, 1,8/I near the protrusion 8 which is the vibration transmitting member shown in FIG.
m ) indicates the maximum amplitude of llij degrees. The phase shift turning point of the amplitude, the so-called vibration node, has a diameter of 100%.
It reached a position of 80 to 85% and changed almost linearly, with an amplitude of about 2.5 μm at the end. Furthermore, when the electrical signal application lead wires 15, 16, and 17 were removed from the vicinity of the vibration node, there was no disconnection due to vibration fatigue. Also,
As shown in FIG. 15, which will be described later, in a practical structure, a buffer body 39 is provided at the bottom of the stator 10. In that case, the stator 1o is curved as shown in FIG. 7 using the buffer body 39 as a base, so that an effect is obtained in which the apparent amplitude is expanded.

By setting the support position near the vibration node, a drive with less loss can be realized. As a result, the lateral component that becomes the thrust of the slider 18 increases in the protrusion 8, and the slider 1
8 moves in a certain direction extremely efficiently.

FIG. 8 shows the relationship between the driving voltage and the rotation speed of the piezoelectric motor according to the present invention. For comparison, (a) shows the characteristics of a conventional surface wave type piezoelectric motor. (b) shows the characteristics of the piezoelectric mold according to the present invention without protrusions; (C)
(d) is the characteristic when the length of the protrusion of the piezoelectric motor according to the present invention in the downward direction is 4 mm, and (d) is the characteristic when the length of the protrusion of the piezoelectric motor according to the present invention in the downward direction is 8 mm. The characteristics of each are shown.

By changing the downward length of the protrusion 8 of the identifier member in this way, the desired row speed can be obtained. From these facts, it can be seen that the piezoelectric motor according to the present invention is extremely efficient. In Figure 8, the maximum speed is 360 rpm,
In a prototype model with a larger diameter comb or a model with a smaller diameter lip 36, we were able to measure a speed of about 11,000 rpm.In addition, the power consumption at this time was 1/10 to 1/1 of that of a conventional piezoelectric motor. It became about 100. Furthermore, the power efficiency was also relatively better than that of DC micro motors and the like.

FIG. 9 shows an example of the configuration of the protrusion 8 forming a part of the stator. The contact surface of the protrusion 8 with the slider 18 has a plurality of holes, for example, 1 or more, each having a depth of several μm to several tens of mjn, in the radial direction perpendicular to the moving direction of the slider 18. Etched or machined knife-etched grooves 21 are provided every 10 degrees or several tens of degrees. Thereby, the effect of cleaning deposits caused by rotational wear of the protrusion 8, slider 18, etc. by the groove 21 can be obtained.

The precipitate is guided inside the groove 21 and transported to the outside.

As a result, the friction coefficient of both the contact surfaces of the protrusion 8 and the slider 18 could maintain the initial friction coefficient and contact area, and the generated torque was always constant.

FIG. 10 shows changes in operating time when the materials of the projection 8 and the elastic body 19 of the slider 18 are changed. A is an elastic body 19 made of a composite material such as asbestos with a rubber binder.
This shows the operating time when configured. b is protrusion 8
The operating time is shown when a structural material such as hardened steel is used as the material.

C indicates the operating time when the elastic body 19 is made of a composite material of pulp, silica, etc. with a synthetic resin binder. d indicates the operating time when the protrusion 8 is provided with a knife-etched groove for cleaning precipitated powder due to rotational wear, as shown in FIG.
The initial characteristics can be guaranteed even after approximately 1,000 hours of rotation.

The rotational speed of conventional piezoelectric motors is limited to a few rotations to about 30 rpm. This is based on the driving principle of a surface waveform using a small amplitude called Zabumicron. It is intended for driving purposes.

The piezoelectric motor according to the present invention that directly uses spatial waves or bulk waves that generate strong vibrations has a driving voltage of 22 Orpm when the projection 8 shown in FIG. 4 has a height of, for example, about 8 cm. The number of rotations is obtained. FIG. 11 shows the relationship between the diameter and the number of rotations when the diameter of the protrusion 8 is changed. The piezoelectric motor according to the present invention has a first
As is clear from FIG. 1, any desired number of rotations can be obtained by selecting the diameter or height of the protrusion 8, from several rotations per minute to manual rotation. Furthermore, since it has a linear characteristic up to a driving voltage of about 200V, the rotation speed can be increased by voltage amplifier. In addition, since the construction principle or component parts do not have any magnetic means such as magnets or coils, for example, 400 r
A piezoelectric motor with a speed of about pm or 700 rpm can be used as a motor for magnetic recording/reproducing equipment such as a floppy disk or a video tape recorder, and has no magnetic influence.

FIG. 12 shows a stator having another configuration. In this configuration, between the first piezoelectric vibrator 25, 25' and the second piezoelectric vibrator 26, there is a
The basic structure is that a stator base 27 having a thickness of approximately twice that is attached is attached.O Still, a protrusion 28 is formed on the surface of the stator base 27 near a position that is approximately % of the diameter, and a shaft 29 is formed at the center. has been done. The material and structure of each part are similar to those of the embodiment shown in FIG. First piezoelectric vibrator 25°25
' and the relative arrangement of polarization of the second piezoelectric vibrator 26.

It is completely similar to the stator 10 having the structure shown in FIGS. 4 and 5. The reason why the first piezoelectric vibrator 25, 26' is divided into two pieces and has a small hole is to allow the protrusion 28 and shaft 29 to pass through. Further, as the drive circuit for this stator, the same structure as the circuit shown in FIG. 6 can be used, so a detailed explanation will be omitted. FIG. 13 shows a stator in yet another embodiment. In this embodiment, the first piezoelectric vibrator electrode 31 and the second
Piezoelectric vibrator electric Vj! , 32 and a stator base body 33 having a thickness equal to or approximately 10 times that of the piezoelectric vibrator. Further, on the surface of the stator base body 33, a ring-shaped projection (not shown) and a shaft 34 are formed near 16 at a diameter of about 3A. The materials and structures of each member are the same as those in the embodiment shown in FIG. The relative polarization arrangement of the first piezoelectric vibrator electrode 31 and the second piezoelectric vibrator electrode 32 is not shown in FIGS. 4 and 5, and is exactly the same as that of the 114-piece stator 10. Further, as the drive circuit for this stator, the same structure as the circuit shown in FIG. 5 can be used, so a detailed explanation will be omitted.

FIG. 14 shows a stator in yet another embodiment. In this embodiment, an annular stator base 37 having a thickness equal to or approximately 10 times that of the piezoelectric vibrator is disposed above the annular first piezoelectric vibrator 36 and the annular second piezoelectric vibrator 36. The basic configuration is that the Further, a protrusion 38 is formed on the surface of the stator base 35 near the maximum amplitude in the vertical direction. The material and structure of each member is the fourth
This is similar to the embodiment shown in the figure. The first piezoelectric vibrator 36 and the second
The relative polarization arrangement of the piezoelectric vibrator 36 is exactly the same as that of the stator 10 having the configuration shown in FIGS. 4 and 6. ) Also, as the drive circuit for this stator, the same structure as the circuit shown in FIG. 5 can be used, so a detailed explanation will be omitted.

Using the drive circuit shown in Fig. 5, the stators shown in Figs. 12 and 13 are driven at a forced excitation frequency of 6 o
When the strain in the longitudinal direction was measured when V was applied, the results obtained were exactly the same as those shown in FIG. 6. When these stators were mounted and driven using a configuration substantially similar to that of the piezoelectric motor according to the present invention shown in FIG. 16, which will be described later, rotational motion ranged from several to several thousand rotations per minute. I was able to get The generated torque varies depending on the friction coefficient and contact area of the sliders, etc. that do not make surface contact with the acoustic material forming the stator, the stator, etc., or the size of the load received, but it is
It was possible to obtain torques in the range from cm to several thousand qf-cm.

FIG. 15 shows a more specific structure of the piezoelectric motor in one embodiment of the present invention. The same parts as in FIG. 6 are given the same numbers. The identifier 10 provided with lead wires 15°16.17 is mounted on a frame (not shown) via a buffer 39 so as to be able to vibrate freely. A slider 18 abuts on the stator 10 by pushing a bearing 40 inserted into the shaft 9.

The pressing force adjustment screw 41 is attached to the two ends of the shaft 9, and when the screw is tightened, the chrysanthemum-shaped plate spring 42 is deflected, and the stator 10 and the slider 18 are brought into contact with each other with an arbitrary pressing force. I can do it. As a result, we were able to obtain a torque in the range of several tens of qf - α to several thousand qf = α. Furthermore, a fixing ring 43 is fixed on the slider 18, and the guide link shown by the imaginary line 44, rotation is transmitted to the rotated body.

The piezoelectric motor with the above configuration not only does not take up much of the apparent storage area, but also can be driven in forward or reverse directions at will by simply changing the phase of the drive signal.
Torque within several thousand qf-α can be generated at low to medium speed rotations within rp. However, the rotation speed can be arbitrarily selected up to about several thousand rotations by selecting the magnitude or phase of the applied signal, the magnitude of the load received by the contact portion, the length and diameter of the protrusion, etc. Therefore, there is no need for a speed reducer or the like. Moreover, since it always forms a contact friction pair, there is no moment of inertia, it is rich in minute pulse operation, and is excellent in compactness. Furthermore, since the structure is extremely simple, it is inexpensive.

Effects of the Invention As described above, the piezoelectric motor according to the present invention includes two piezoelectric vibrators in the stator, and both piezoelectric vibrators have at least a pair of piezoelectric vibrators whose polarization directions are alternately reversed in the slider movement direction. The piezoelectric vibrators are divided into two regions and are arranged to be shifted by approximately half a region from each other, and a slider is brought into contact with the stator of the stator through the vibration transmission part opening. By applying a voltage of a predetermined frequency, a vibration wave moving in a fixed direction is generated in the stator, and the slider is driven. It is now possible to configure a motor with an extremely simple structure, making it possible to realize a motor that is small and has good response.

Furthermore, because the structure is such that a lateral component that becomes thrust is obtained by directly exciting a disk-shaped bulk wave, the mechanical displacement increases several times at a constant voltage, and the deflection in the cross-sectional direction increases. Since the entire range is output, it is possible to extract the peak speed without averaging the speed.

[Brief explanation of the drawing]

FIGS. 1 and 2 are a sectional view and a plan view showing the configuration of a conventional piezoelectric motor, respectively, FIG. 3 is a perspective view showing its operation, and FIG. 4 is a piezoelectric motor according to an embodiment of the present invention. FIG. 5 is an exploded perspective view of the stator, and FIGS. 6 and 7 are cross-sectional views showing an outline of a piezoelectric motor using the same stator and its drive circuit.
The figure shows the strain distribution when the piezoelectric motor f,',I constant of Fig. 5 is driven, Fig. 8 is a graph showing the characteristics of the rotation speed with respect to the drive voltage of the piezoelectric motor according to the present invention, and Fig. 9 is the same. A perspective view of the main part of the motor identifier, Fig. 10 is a graph showing the operating time characteristics of the motor, and Fig. 11 shows the rotation speed of the motor 1b with respect to the diameter of the main part of the stator of the piezoelectric motor according to the present invention.
FIG. 15 is an exploded perspective view of the J-stator and a partially sectional front view showing the specific structure of the piezoelectric motor in one embodiment of the present invention. 5.6, 25.25', 26, 30, 35, 36...
... Piezoelectric vibrator, 5a, 31, 32 ... Electrode, 1o ... Stator, 18 ... Slider, 1
1...Oscillator, 12, 14...Amplifier, 1
3... Phase shifter. Name of agent: Patent attorney Toshio Nakao (1st person)
Figure 2 Figure 3 Figure 4 Rod 5 Figure 6 Figure 10-+ Range 7 Figure 8 y! Section J dynamic activation pressure Pfl Figure 9? l 1st ON □□■ 〃θ (Hθαr) Fig. 11 Straight 4 flea (mH) Fig. 12 Fig. 14 Fig. 150 917

Claims (9)

[Claims] (1) Two plate-shaped piezoelectric vibrators, each of which is divided into at least one pair of regions and configured such that the polarization direction of each region is alternately reversed, are placed near the medium heat part of each of the regions in one of the piezoelectric vibrators. The plate-shaped piezoelectric vibrator is arranged so that the boundaries of each region are located, and a base made of an acoustic material or the like is placed.
A vibration transmitting member comprising a stator stacked in multiple layers together with the piezoelectric vibrators and a slider facing the stator, and in contact with the slider on the surface of the stator. A piezoelectric motor characterized by having: (2) The piezoelectric motor according to claim 1, wherein the vibration transmission part is provided near the maximum displacement position of the stator. (3) The diameter of the vibration transmission part is several mm to several 1'O
Claim WJ1 characterized in that it is about mm.
Piezoelectric motor as described in section. (4) The thickness of the vibration transmission member is the same as that of the piezoelectric vibrator or 1
Claim 1 characterized in that it is about 00 times
Piezoelectric motor as described in section. (5) The piezoelectric motor according to claim 1, which has a plurality of grooves with a depth of several βm to several 1ofi on the slider contacting surface of the vibration transmission part. (6) The piezoelectric motor according to claim 1, wherein both piezoelectric vibrators are disk-shaped. (7) It is a good feature that both piezoelectric vibrators are equally divided! The piezoelectric motor described in the section ``Range of Required by J Revised Jt5''. (8) Two pressure 7L oscillators transmit voltage at a predetermined frequency.
A special πF characterized in that it is applied with a very different phase.
A piezoelectric motor according to claim 1. (9) The piezoelectric motor according to claim 1, characterized in that it has an axis at the center of F^゛j constant -f. QC? 2. The piezoelectric motor according to claim 1, wherein the slider comprises an elastic body located on the stator side and an acoustic material bonded to the elastic body. The piezoelectric motor according to claim 1, wherein the lead wire for applying an electric signal is fixed near the vibrating part.