摘要:
A method for controlling the driving of an ultrasonic motor (110), including the steps of (i) sweeping a driving frequency of the pair of AC driving voltage signals from a starting frequency higher than a frequency of the vibrator (3) of the ultrasonic motor (110) in a stationary state when the ultrasonic motor (110) is started driving ; (ii) supplying supply power to the ultrasonic motor (110), the supply power being initially a minimum supply power capable of realizing a predetermined maximum rotation speed of the ultrasonic motor (110) under a standard load ; and (iii) when the driving frequency exceeds a frequency which is capable of realizing a maximum rotational power of the ultrasonic motor (110) by a current supply power, shifting the driving frequency toward sufficiently higher than the resonance frequency of the vibrator (3) in a stationary state, and increasing the supply power supplied to the ultrasonic motor (110) in a stepwise manner.
摘要:
An acceleration sensor includes: a piezoelectric vibrator including a piezoelectric element having a first principal surface and a second principal surface opposed each other, a first and a second electrode formed on the first and the second principal surface, and conductive protrusions made of a metal material or a ceramic material and formed by a thermal spraying process; and a holding body for holding the piezoelectric vibrator via - the conductive protrusions.
摘要:
A bimorph element (104) is formed by bonding first and second piezoelectric bodies (101, 102) together with an elastic shim (103) interposed between. The bimorph element (104) is firmly held by a base frame (105) which has a recess and a groove at the bottom of the recess. The elastic shim 103 has an extending portion (103a) which is firmly inserted in the groove and its end portion is inserted in the recess of the base frame (105). A space between the recess and the end portion of the bimorph element is filled by an elastic support member (108).
摘要:
A method for controlling a moving velocity of an ultrasonic motor comprising a vibration body for causing ultrasonic vibration in response to two AC driving voltage signals having a common frequency, a common amplitude and phases different from each other; and a moving body in contact with the vibration body and moved by the ultrasonic vibration. The method includes step A of detecting a velocity of the moving body; step B comparing the velocity detected in step A with a predetermined velocity; and step C for adjusting the frequency of the two AC driving voltage signals and the amplitude of or the phase difference between the two AC driving voltage signals, based on the comparison result to allow the velocity of the moving body to be closer to the predetermined velocity.
摘要:
An ultrasonic motor comprising vibrating body (1), piezoelectric body (2) for exciting an elastic travelling wave in the vibrating body and moving body (4) driven by the elastic travelling wave provides plural vibration amplitude detection electrodes for detecting an amplitude of vibration of the vibrating body these output signals from which are utilized to identify the magnitude of vibration amplitude of the vibrating body and the ultrasonic motor is controlled using the magnitude of vibration amplitude as a control index.