Showing papers on "Piezoelectric motor published in 1985"

A Piezoelectric Ultrasonic Motor

Abstract: A piezoelectric ultrasonic motor is constructed by tightly contacting a rotor to a piezoelectric ultrssonic resonator with eliptical vibrstion (PUREV). The PUREV successfully operated with a torsion coupler in which a torsional mode coupled with a bending mode is excited by the same frequency longitudinal vibration. The typical values of the present motor are 120 r.p.m. with no load, and 90 r.p.m. with a load of 13 kg-cm, under a 40 kHz/100 volt sinsoidal voltage, i.e. 12 watts with 80% efficiency. These values correspond to a high output power density of 80 W/kg over the limit value 30 W/kg expected in the ordinary motors.

Piezoelectric vibrating elements and piezoelectric electroacoustic transducers

Abstract: A piezoelectric speaker including a plurality of piezoelectric vibrating elements, each including a piezoelectric vibrating plate and a weight connected to near the point of center of gravity thereof through a viscoelastic layer, and having the vibramotive force designed to be taken out of the outer edge thereof, which are connected at their peripheral ends to each other through connectors, one of said elements being connected at its peripheral edge directly to a cone type acoustic radiator to give thereto a vibramotive force mainly in a high-frequency portion, and the remaining elements adjacent thereto producing a vibramotive force adapted to share middle- and low-frequency portions for energization of said cone type acoustic radiator.

Underwater piezoelectric arrangement

Abstract: Underwater piezoelectric arrangement in which it comprises two piezoelectric elements made of piezoelectric ceramic-polymer composites and juxtaposed to form a single layer structure, one of the element(s) having larger hydrophone constant than that of the other element(s), and by noise cancelling of the piezoelectric assembly there can be selectively detected only charges or voltages generated by acoustic waves which acts on each element.

Ultrasonic transducer using piezoelectric composite

Abstract: An ultrasonic transducer using a piezoelectric composite in which a plurality of piezoelectric poles are arranged in matrix maintaining a gap and a polymer is charged into the gap. The piezoelectric poles are arranged maintaining a pitch which is shorter than a wavelength of a sound wave at a fundamental resonance frequency of the transducer in a medium. Further the pitch may be changed in a direction in which the piezoelectric poles are arranged, in order to restrain the grating lobe from generating.

Torsional mode ultrasonic vibrator

Abstract: A torsional mode ultrasonic vibrator is formed by integrally combining a piezoelectric thickness vibrating element and a cylindrical torsional mode resonator. Furthermore, a torsional mode piezoelectric motor is provided in such a manner that a rotor and a stator are pressed to each other so that a rotational torque can be generated by the vibration at the contacting surfaces therebetween and a piezoelectric thickness vibrator and a torsional mode ultrasonic vibrator formed by an integral combination of a torsion coupler and a torsional mode ultrasonic resonator are used as the source of the ultrasonic vibration.

Flexible piezoelectric transducer assembly

Abstract: A flexible piezoelectric transducer assembly for producing sonar signals for transmission underwater and for detecting reflected sonar signals. The assembly includes a generally flat, flexible casing formed with a plurality of compartments, each of which is for receiving a piezoelectric element. A plurality of piezoelectric elements are disposed in each of the compartments and are coupled by way of conductors to electronic circuitry which produces electrical signals for stressing the piezoelectric elements and which processes electrical signals produced by the piezoelectric element in response to reflected sonar signals. The piezoelectric elements are spaced apart in the casing to allow flexing and bending, while also maintaining high packing density. The piezoelectric elements are also selected to have low cross-coupling characteristics.

Piezoelectric ratio weighing device

Abstract: A piezoelectric device is used to determine a ratio of a second weight with an original weight where the second weight is less than the original weight. A piezoelectric driver is resiliently attached to a base that is isolated from vibrations. A piezoelectric receiver and a reed are resiliently attached to the piezoelectric driver so that (1) the read is moved in response to motion of the piezoelectric driver, and (2) the piezoelectric receiver gives an electric signal out proportional to motion of the system. The entire system is set to operate on the leading edge of the resonant frequency for the system. By applying an oscillating sine wave voltage, such as 140 hertz, to the piezoelectric driver, and by applying an unknown mass to the tip of the reed, a first output is obtained from the piezoelectric receiver which represents the original weight. Next by removing part of the mass by any convenient means, such as heat, a second output is obtained that represents the second weight. By a ratio of the second output/first output (or a signal equivalent to the weights being measured), the percent of the mass remaining is determined.

Piezoelectric scanning device

Abstract: A piezoelectric scanning device comprises X-direction and Y-direction piezoelectric drive sections coupled to mutually perpendicular Z-direction piezoelectric clamping members. The selective application of voltages to the piezoelectric elements included in the X-direction and Y-direction drive sections and the Z-direction clamping members enables movement of the scanning device in two directions.

Piezoelectric linear motor

Abstract: PURPOSE:To obtain a piezoelectric motor which has high efficiency by utilizing space wave or bulk wave by superposing two piezoelectric vibrators having dividing areas, an acoustic material and a vibration transmitting member in the thicknesswise direction to form a stator, and plane contacting it with a slider. CONSTITUTION:Elliptical piezoelectric vibrators 1, 2 polarized in the thicknesswise direction by dividing plural pairs of regions circumferential direction and alternately inverting the divided regions are prepared, and superposed so that the center of the divided region of the other vibrator is disposed on the boundary of the divided regions of one vibrator. Further, a base 3 made of an acoustic material is superposed thereon to form a stator 7, and a vibration transmitting member such as an annular projection is provided on the surface. A vibrator 15 is plane contacted at the sliding surface with the member 4. Thus, efficient space or bulk wave excited by the vibrator is directly utilized for the drive force.

Electric switch device comprising at least a piezoelectric organ

Abstract: A piezoelectric component (11) which operates as a mechanical/electrical transducer comprises a signal input (14) of a circuit (12) which possesses a control signal output and contains a digital bandpass filter (32) with a transmission range of, for example, 0.5 to 10 Hz and preferably 2 to 4 Hz. In this way, piezoelectric voltages outside the transmission range (32) are ineffective, which thus almost completely avoids disturbance due to temperature, impact, vibrations and sound waves. Apart from its function as a mechanical/electric transducer to perform control processes, the piezoelectric component (11) can also be used as an electromechanical transducer in order to produce sound waves, thus providing an audible signal in return. The circuit (12) possesses for this purpose a sound-frequency oscillator (42) and manually-operated means (30, 40, 41, 43) in order to connect provisionally this oscillator (42) to the piezoelectric component (11).

Piezoelectric motor of spiral mode drive

Abstract: PURPOSE:To reversely move instantaneously a movable element by press-bonding a piezoelectric vibrator of slide mode onto the slide surface of the movable element CONSTITUTION:Twisting piezoelectric vibrators 4, 5 of slide mode are contained in a case 11, and a clamping bolt 6 and the pawls 12 of the case 11 are engaged with the bolt 6 so that the vibrators 4, 5 do not rotate The disc surfaces of a twisting slide plate 7 are formed of sheaths 13, and a rotor 10 in which bearings are mounted in the bores is press-bonded Press-bonding elements 14 are of laminated piezoelectric elements, and when the same signal as applied to the plate 7 is applied, the rotor 10 is press-bonded to the disc surface of the periodic twisting plate 7 through the bearings When the applied signal is in positive phase, the rotor 10 is rotated in positive direction, and when the applied signal to the element 14 is in reverse phase, the rotor 10 is instantaneously rotated reversely

Piezoelectric motor of standing wave type

Abstract: PURPOSE:To obtain a strong torque by a small-sized motor by obtaining a slide torque in combination of vibrators of a standing wave of bending mode and a twisting mode. CONSTITUTION:A twisting coupler 3, a thickness vibrator 1 and a terminal board 1 are superposed on a twisting resonator 4, and the legs are coupled with a supporting cylinder 2 to form a ring-shaped vibrator. A twisting coupler for vibrating it is composed to radially attach a toothed plate on one side of a doughnut-shaped disc 4 in the shape that the disc 4 is equally divided into three sections. The positive or engative polarized surfaces of doughnut-shaped piezoelectric vibrators 6, 7 are opposed, a terminal board 81 is interposed therebetween a cap bolt 10 is inserted into a washer 9, and a cap bolt 10 is engaged with the threaded hole of the vibrator. A sinusoidal voltage is applied to lead wirings 11, 12 connected with the boards 81, 82.

Motor of electronic timepiece

Abstract: PURPOSE:To reduce the size and thickness of a motor by providing rotary position detecting means in a piezoelectric motor which has an elastic unit, a piezoelectric element and a rotor to use as the motor of a timepiece for the piezoelectric motor and to eliminate the influence of an external magnetic field. CONSTITUTION:A ring-shaped elastic unit 2 is mounted on the back with piezoelectric elements 5, 6, which has a structure for applying alternating electric field in a thicknesswise direction by electrodes 7, 8 with the unit 2 as an earth electrode. A bearing 3 is secured to the unit 2. Further, a light emitting diode 10 formed on a substrate 9, a through hole formed at the rotor 1 and a phototransistor 12 provided on the bearing 3 are provided in a rotating position detecting structure of the rotor 1.

Composite piezoelectric vibrator with trapezoidal cross section

Abstract: A piezoelectric vibrator capable of vibrating in an expansion mode of vibration comprising a piezoelectric vibrating element, composed of a vibrateable substrate, made of a constant elastic metal, a thin film of piezoelectric material and an exciting electrode layer. The substrate has a generally trapezoidal cross-sectional representation, as viewed in a direction perpendicular to the direction of propagation of vibrations, with one of the opposite surfaces thereof adjacent the thin film being greater than the other of said opposite surfaces.

Piezoelectric electroacoustic transducing device

Abstract: PURPOSE:To inexpensively mass-produce a piezoelectric electroacoustic transduc er which is small in size, light in weight, high in reliability, and good in manufac turing yield with high performance having constant quality, by forming an enclosure and sound producing and receiving element of the same material integrally. CONSTITUTION:A piezoelectric plate 11 for sound production or sound reception, electrodes 12 and 12', elastic plate 13, and box body 15 are united integrally and the parts except the electrodes 12 and 12' are constituted of a piezoelectric ceramic material. At the time of sound production, AC electric signals are inputted to electrode terminals 14 and 14' and the piezoelectric plate 11 put between the electrodes 12 and 12' tends to extend and shrink in the lateral direction due to a piezoelectric effect. Since the piezoelectric plate 11 is joined to the piezoelectric inert elastic plate 13 integrally, the piezoelectric plate, electrodes 12 and 12', and elastic plate 13 are deformed by bending upward or downward integrally. Thus input electric signals are converted into acoustic energy and sounds are transmitted to the outside through through-holes 16 provided in the upper part of the enclosure 15.

Hollow piezoelectric motor

Abstract: PURPOSE:To improve the operating efficiency with a simple structure by obtaining the frictional force of a stator and rotor sections by supplying a pressing force for pressing the sections through bearings. CONSTITUTION:The first and second bents 1a, 1b for forming a mounting space of parts of a hollow cylindrical base 1 which forms the outer wall of a hollow piezoelectric motor are provided at both ends. The base 1, a buffer plate 2, a piezoelectric unit 3 and a vibration plate 4 form a stator section A of the motor, and a rotary plate 5, and a drive member 6 form a rotor section B corresponding to the section A. A bearing 7, a spring 8 and a spring retainer 9 are held to move circumferentially and axially on the inner periphery of the base 1.

Piezoelectric motor of twisting mode drive

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.

Piezoelectric driven direct current latching relay.

Abstract: not available for EP0164682Abstract of corresponding document: US4553061A direct current latching relay comprised of bender-type piezoelectric drive members each of which is a three terminal member formed of two piezoelectric plate elements separated by a conductive plane. Each piezoelectric plate element is separately electrically charged with an input pulsed d.c. switching signal of the same polarity as the pre-poling field previously induced in the piezoelectric plate element. By electrically charging one of the piezoelectric plate elements with a switching signal electric field of the same polarity as the pre-poling field, the bender-type drive members are member made to bend in one direction. Alternatively, by charging the opposite plate of the drive member again with a direct current electric charging field of the same polarity as the pre-poling field previously induced in the plate, the bender-type drive member can be caused to bend in the opposite direction. The bender-type piezoelectric drive member when bent engages and drives a push rod which actuates a snap-action switching contact mechanism from either an open circuit state or to a closed circuit state or vice versa. Pulsed direct current charging fields are applied to the piezoelectric plate element of the bender-type drive member and a high resistance discharge resistor is connected across each of the piezoelectric plate members so as to automatically discharge the plate members shortly after their excitation. As a result, no long term depolarization of the piezoelectric plate members occurs and because of the pulsed short term nature of the charging fields, no long term deformation (creep) develops in the plate elements over extended periods of usage of the relay.