JPS60148386A - Piezoelectric motor of twisting mode drive - Google Patents

Abstract

PURPOSE:To reduce the wear of sliding surfaces upon generating of a vibration torque by employing a supersonic vibrator of twisting mode integrally composed with a piezoelectric thickness vibrator, a twisting coupler and a twisting mode resonator, thereby planely contacting a rotor with a stator at the bonding surfaces. CONSTITUTION:A twisting coupler 3, a thickness vibrator 1 and a terminal board 1 are superposed on a twisting resonator 4, contained in a cylindrical motor case 6, and clamped to the threaded hole of the bottom of the resonator 4 through a cap bolt 5, thereby forming a stator. A rotor 7 is formed of an aluminum disc, and a rotational shaft projected from the center of the disc. When a cover 8 is secured by screws to the motor case 6, the surface of the rotor 7 is press-bonded to the end face of the resonator 4. When a sinusoidal voltage is applied through lead wirings 12, 13, the rotor 7 is rotated.

Description

[Detailed Description of the Invention] [Technical Field - Object of the Invention] The present invention relates to the improvement of a piezoelectric device, and in order to reduce the wear of the sliding surface due to the generation of sliding torque, The purpose of the present invention is to provide an FE'im motor that reduces the burden of sliding pressure.

[Background technology]

A pressure motor that is crimped onto a rotor-like stator and generates rotational torque by ultrasonic vibration between N contact surfaces has an inclined plate called a vibrating piece between the rotor and stake, without directly crimping the end faces of the stake. Place the ultrasonic transducer vertically.
! (Convert 1 to the rotational torque in the vertical plane. There is a piezoelectric motor called the "glitter type", but the drawback is that the sliding surface of the vibrating piece is subject to severe wear.

A method that compensates for this drawback is called the surface wave type or traveling wave type, and there is a piezoelectric motor that rotates the rotor by generating a traveling wave with the rotor surface and stator surface directly pressed together. It is difficult to generate traveling waves. In order to generate traveling waves, it is necessary to suppress the generation of reflected waves and unidirectional waves, so the drawback is that the generation efficiency is low.

[Summary of the invention]

This invention solves the above-mentioned drawbacks of the prior art.
In a piezoelectric motor in which the rotor is crimped onto the stator and rotational torque is generated by ultrasonic vibration between the contact surfaces of the two, and this is used as the driving force, the rotational torque source generated by the ultrasonic vibration includes a piezoelectric thickness vibrator, a torsion coupler, and a rotor. This objective has been achieved by a torsion mode driven piezoelectric motor characterized by using a torsion mode ultrasonic vibrator in which torsion resonators are integrally connected. Embodiment q of the present invention will be described below with reference to the drawings.

〔Example〕

Embodiment 1 FIG. 1 shows an embodiment of a piezoelectric motor for driving a twisting motor according to the present invention. 1 is outer diameter 35 IIIe inner diameter 15YIm
#It is a two-thickness oscillator made of Pb (ZrTi) On-based doughnut-shaped piezoelectric heptaramic with a thickness of 2II DII, and between the positively polarized surfaces facing each other, the outer diameter is 35 mm, and the inner diameter is 1"5 m and 111 m. A terminal board 2 made of phosphor bronze with a thickness of 0.1 mm was sandwiched.

Outer diameter 3.5 ram a inner diameter 1! rtm *thickness 1
Cut 8 grooves radially in the vicinity of one open end of a 5 am aluminum cylinder, 3 deep, 2 wide, and 8 grooves, and insert a plate 2 mm thick, 9 wide, 7 mm high, and 11 mm high into these grooves. The torsion connector 3 is constructed by vertically fitting the eight plates, and twisting and deforming the tips of the eight tooth-shaped plates using the axis of the aluminum cylinder as the rotation axis. Then, the end surface of the deformed toothed plate 31 is brought into contact with the bottom surface of the torsional resonator 4. The torsional resonator 4 is a cylinder with a garden.
It has the function of causing torsional vibration applied to the bottom surface to resonate in the body, and the length of the cylinder is important in determining the resonant wave number, regardless of the diameter and wall thickness of the cylinder. Here, the torsion resonator 4 is a trapezoidal cylinder with a body length of 70 mm, an outer diameter of 50 mm at the tip, and an inner diameter of 36 mm.

The torsion resonator 4 described above has a torsion coupler 3. Thickness vibrator 1
and the terminal plate 2 are placed in a cylindrical motor nurse 6, and a cap bolt 5 with a diameter of 10 mm and a length of 40 mm is inserted from the bottom.
A torque wrench was used to tighten the screw hole on the bottom of the torsional resonator 4 with a force of 150 KB@cm. In this way, a stator for a piezoelectric motor driven in torsional mode was completed.

The rotor 7 is made of an aluminum disc with a diameter of 501RIna and a thickness of 10 gates, and a 1011111 plate protruding from the center of it.
Diameter.

It consists of a rotating shaft with a length of 20 mm. A coil spring 10 was fitted to the rotating shaft to form an inner retainer for a ball bearing 9 embedded in the center of a 6Ω motor case lid 8, and an output gear 11 was screwed to the tip of the shaft and then fixed with a bottle. When the lid 8 is fixed to the motor case 6 with screws, the surface of the rotor 7 is pressed against the end surface of the torsional resonator 4. When a sine wave voltage of approximately 10 volts and 24.5 KH2 is applied to the assembled motor through the leads li1[12, 13, the rotor 7 rotates powerfully and a rotational output is obtained from the gear at the tip.

The number of rotations is several revolutions per second, which is quiet, but if the same wave number is slightly changed, rotation will occur, and if the frequency of 101+ changes, the rotation will stop, so frequency control is important.

Furthermore, if you touch the periphery of the cylinder of the resonator 4 with your hand, the Q will decrease and the rotation will stop, so a type of brake that lightly applies hard rubber along the circumference can be installed.

In addition, the electrical high frequency input to operate the motor is
Forward and reverse rotation is possible by switching to two slightly different wave numbers of the same type.Embodiment 2 In the torsion mode driven piezoelectric motor of the present invention, the torsion resonator plays the most important function. . It is about 40mm for 80III+1.39KH2 for KHzK of the resonator, but as the length becomes shorter, the amplitude of torsional vibration becomes smaller, so it is appropriate that the length l is 50 or more and the frequency is 35KH2 or less. . Since the resonator tends to become longer in this way, the overall length of the piezoelectric motor may become longer. An embodiment that solves this problem will be described below.

The components are almost the same as in the first embodiment. Thickness vibrator 20
are stacked on the torsion coupler 22 and the washer 24, and are fixed together by strongly tightening the cap bolt 26 inside the cylindrical torsion resonator 25. Here, the torsion connector 22 is the one according to the first embodiment.
Similarly, since the vertical vibrator is a body with respect to the toothed plate 23 of K, the length is set to 35#llI+ so that the vertical resonance frequency is close to the torsional resonance. At first glance, the torsional resonator 25 looks like the teeth of a motor, but when the torsional vibration is excited by the toothed plate 23 of the connector 22, which is tightened with a pole on the bottom, and the body resonates, the free surface of the tip Large amplitude occurs. The rotor rotates when the four-piece 28 is crimped to the tip surface.
The ball bearing 27 is inserted through the coil spring 29, and is fixed with a nut 31.
The output gear 30 is formed integrally with the quadrupler 28.

With this method, the size of the piezoelectric motor driven in torsion mode could be reduced to about 273 mm. The resonator of the torsional mode-driven piezoelectric motor of the present invention must be designed to a size that allows only the torsional mode and vertical mode to be excited without parasitizing other modes such as the bending mode. If the design includes a vibrator, reverse rotation can be achieved by slightly changing the excitation frequency.

〔Effect of the invention〕

As explained above, in a piezoelectric motor in which the rotor is viewed from the stator and a rotational torque is generated between the contact surfaces of the two by ultrasonic slow motion, and this is used as a driving force, the rotational torque source by ultrasonic vibration is piezoelectric thickness vibrator, torsion coupler,
Since the configuration uses a torsional mode ultrasonic resonator that integrates a torsional mode resonator and a torsional mode resonator, the rotor and stakes can be crimped in surface contact, which increases the frictional force and reduces the crimping force per unit area. Not only can it be made light and therefore prevent wear on the sliding IUI, but it can also be easily rotated in reverse by switching between the 1st and 4th wave numbers of the drive, which is an advantage not possible with the "Kiratsuki type". Of course, in the case of a "surface wave type motor", it is possible to rotate in the opposite direction, but even though the frequency is the same, the phase is 90°.
Compared to having to use two different high-pitched wave inputs at the same time, the reverse rotation force method of the torsion mode driven piezoelectric motor of the present invention is simple and has great effects.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view for explaining an example of a piezoelectric motor driven in a torsion mode according to the present invention, and FIG. 2 is a vertical cross-sectional view showing another embodiment of a piezoelectric motor driven in a torsion mode according to the present invention. It is. 1.20...Thickness vibrator, 3.22...
・Torsion connector, 3.23...dentate plate, 4,25
...Torsional resonator, 5.26...Cap bolt, 7.28...Quarter. 11 72 threshold

Claims (1)

[Scope of Claims] (1) In a piezoelectric motor that is crimped onto a rotor-like stator and generates a rotational torque due to ultrasonic vibrations of 11tJ ItC between the contact surfaces of the two, and uses this as a driving force, the rotational torque due to the ultrasonic vibrations is used. A torsion mode driven piezoelectric motor characterized in that a torsion mode ultrasonic vibrator in which a piezoelectric thickness vibrator, a torsion coupler, and a torsion mode resonator are integrated and connected is used as a source. (2. In claim (1), the twisting mechanism is characterized in that the motor is rotated in the opposite direction by switching the electrical and electrical high-frequency input for operating the motor to two IM waves that are slightly different from each other. A mode-driven piezoelectric motor. (8) In claim (1), a brake is provided along the circumference of the torsional resonator and brought into contact with the cylindrical surface of the resonator to increase the quality factor Q of the vibration system. A piezoelectric motor driven in a torsional mode, which is characterized by the ability to suppress or stop rotation by lowering the rotation.