摘要:
A drive unit 20, comprising a moving body 24 and a friction drive member 26 fixedly attached at each end of a piezoelectric element 22 in the layer direction, is disposed between a pair of fixed friction members 14 having a plurality of divided contact parts 15 divided by notches 14s formed at equal spacing along the movement path of the friction drive member 26. The divided contact parts 15 are arrayed so as to be slightly inserted into the movement path of the friction drive member 26, and become elastically deformed when in contact with the friction drive member 26 so as to exert a force on friction drive member 26 in reaction thereto. This exerted force remains uniform regardless of the relative position of the friction drive member 26.
摘要:
A drive device using an electromechanical transducer having inconsiderable loss of drive energy and excellent drive efficiency even with variation in load in which an elastic member is arranged between a driven member frictionally coupled to a drive member and a frictional member fitted to an opening of the driven member whereby drive force is transmitted from the drive member to the driven member with no loss of energy, a frictional force between the drive member and the driven member is periodically changed, an average frictional force is increased when a shift between a phase of variation in a drive velocity and a phase of variation in the frictional force is null, when the shift between the phases is 180.degree., the average frictional force is adjusted to decrease whereby the drive efficiency can be promoted, and when the device is stopped, the drive device can be protected against unintentional external force bringing the drive member and the driven member into fixing contact with each other by an electromechanical transducer.
摘要:
A drive device using a piezoelectric transducer for correcting a shift of a position of a drive system based on a change in an environmental state such as environmental temperature, in which a drive member coupled to the piezoelectric transducer is driven by causing displacements having different speeds by applying drive pulses of saw tooth waves to the piezoelectric transducer thereby moving a slider block frictionally coupled to the drive member, an amount of a shift of a position of the slider block based on the change in the environmental temperature is previously stored to a memory, when a change in temperature is detected by a temperature sensor, the amount of the shift of the position of the slider block is calculated in accordance with the change in temperature and the shift of the position of the slider block is corrected by driving the piezoelectric transducer in a direction of correcting the shift amount by driving a fine adjustment circuit.
摘要:
A drive device which repeats charging and discharging at different velocities by applying drive pulses to a piezoelectric transducer, causes vibrations with different velocities in the piezoelectric transducer to cause contraction and expansion displacements in a driving member fixedly coupled with the piezoelectric transducer for moving a member frictionally coupled to the driving member. In order to provide stable driving force, stable driving velocity and precise movement, a piezoelectric transducer constituted by stacking a plurality of unit elements is divided into a plurality of blocks having different numbers of lamination layers for driving. A change in impedance by the division is compensated by a compensation circuit, or a plurality of driving circuits corresponding to the impedance are provided and a block and a driving circuit of the piezoelectric transducer are selected in accordance with the driving velocity and moving distance for driving.
摘要:
An actuator using vibration caused by a piezoelectric element. The actuator includes: an driving rod bonded to one of the piezoelectric element; a engaging member for engaging frictionally with the driving rod; and a control circuit for applying the piezoelectric element with a driving voltage. The control circuit is provided with a drive circuit which generates a first set of the driving voltage for driving the engaging member, and with a friction reducing circuit which generates a second set of the driving voltage for reducing a frictional force exerting between the driving rod and the engaging member.
摘要:
A surface acoustic wave motor with high energy efficiency, which may efficiently execute recovery of energy of surface acoustic waves propagated to the ends of piezoelectric substrate and re-excitation by the recovered energy, includes a comb-shaped electrode having interdigital structure for generating surface acoustic waves and two unindirectional comb-shaped electrodes having interdigital structure for recovering and re-exciting surface acoustic wave energy arranged on a piezoekextric substrate, and a slider disposed between the comb-shaped electrode for generating surface acoustic waves and the unindirectional comb-shaped electrodes for recovering and re-exciting surface acoustic wave energy. The surface acoustic wave generated by the comb-shaped electrode is recovered as electric power by unindirectional comb-shaped electrode arranged at one end of the piezoelectric substrate, and applied to the unindirectional comb-shaped electrode arranged at the other end thereof to re-excite the piezoelectric substrate.
摘要:
An apparatus having a drive device using an electromechanical transducer capable of being used in an environment in vacuum, at high temperatures and shielded from outside, an environment where electromagnetic waves are shielded or the like, where a drive shaft and a slider block frictionally coupled thereto are arranged at the inside of a hermetically-sealed vessel, one end of a drive shaft is made to penetrate a wall face portion of the hermetically-sealed vessel and the drive shaft is coupled with a piezoelectric element arranged at the outside of the vessel, the wall face portion of the hermetically-sealed vessel where the drive shaft penetrates is made elastically deformable, a portion between the wall face portion and the drive shaft is shielded in airtight by an adhesive agent and elongation and contraction displacements having different velocities are caused at the piezoelectric element whereby the slider block frictionally coupled with the drive shaft and members fixed to the slider block at the inside of the hermetically-sealed vessel are moved in a predetermined direction.
摘要:
A movable stage utilizing an electromechanical transducer. An actuator as a drive source thereof is composed of piezoelectric elements, drive member fixed thereto and a movable member friction-coupled with the drive member. When a drive pulse is applied to the piezoelectric element to cause it to show reciprocal displacements at different rates in the thickness direction, the movable member frictionally coupled with the drive member moves in the predetermined direction to move the movable table coupled with the movable member in the predetermined direction. The movable stage comprising the movable table moving in the two axes or three axes can be constituted by providing the actuator in the two axes or three axes crossing with each other.
摘要:
A smooth impact drive mechanism utilizing an electromechanical conversion element, in which a preheating voltage to preheat the electromechanical conversion element is impressed thereto before the impression of a drive voltage to the electromechanical conversion element, in order to realize stable drive characteristics by reducing fluctuation in the speed of the moving unit. In addition, drive parameters are changed in accordance with the temperature of the electromechanical conversion element. Furthermore, drive parameters are changed in accordance with the moving speed of the moving unit.
摘要:
A driving apparatus includes an electromechanical conversion element that expands and contracts through the application of a drive voltage, the electromechanical conversion element includes a first end and a second end. The apparatus further includes a support member that is fixed to the first end of the electromechanical conversion element in a direction of expansion or contraction of the electromechanical conversion element; a drive member that is fixed to the second end of the electromechanical conversion element in the direction of expansion or contraction; an engaging member that engages with the drive member with a friction force; and a drive circuit that drives the electromechanical conversion element. The drive circuit generates a rectangular waveform drive voltage and applies the rectangular waveform drive voltage to the electromechanical conversion element to cause the electromechanical conversion element to expand and contract at different speeds to thereby move the support member and the engaging member relative to each other.