JPH03155374A - Ultrasonic motor - Google Patents

Abstract

PURPOSE:To obtain a highly efficient miniature ultrasonic motor having simple structure by connecting a piezoelectric vibrator producing thickness slip displacement and a piezoelectric vibrator producing a displacement in the direction of thickness or a potential in the longitudinal direction, in series, and then fixing the opposite ends thereof. CONSTITUTION:Upon application of +E1 voltage onto the electrode C of a slip vibrator 2, a slip displacement is produced to push up an insulator 3. Upon application of +E2 voltage onto the electrode A of a longitudinal vibrator 1, the vibrator 1 elongates in the longitudinal direction to move the insulator 3 to the right. The insulator 3 lowers upon interruption of voltage from the slip vibrator 2. Upon interruption of voltage from the longitudinal vibrator 1, the insulator 3 moves to the left thus completing one cycle. In such a manner, upper face of the insulator 3 moves along the sides of a rectangle or a rhomb thus moving the vibrators 1, 2. Vertical vibrator 1 and horizontal vibrator 2 can be arranged on one plane.

Description

[Detailed description of the invention] skin 4 water disaster The present invention relates to an ultrasonic motor.

BACKGROUND OF THE INVENTION In recent years, piezoelectric displacement elements have been actively developed and applied. Piezoelectric elements are attracting attention as actuators for precision positioning because they can relatively easily achieve displacement accuracy on the order of submicrons through voltage control.

By incorporating an electrostrictive element or a magnetostrictive element into an elastic body, ultrasonic waves excited on the surface are utilized, and the powerful vibrational energy of the ultrasonic waves generates a traveling wave accompanied by elliptical vibration. JP-A-58-148682 proposes a motor device that utilizes surface acoustic waves that are generated and converted into rotational or rectilinear motion of a moving body. However, since the motor device disclosed in the publication uses surface acoustic waves, it requires a high frequency, and the displacement is small.Also, it requires a driving wave with a correct phase difference, which has the disadvantage of high circuit cost. there were.

Also, IEICE Technical Report, US88-61 p, p29-36
(rotating inchworm type actuator), an ultrasonic motor has been proposed that uses a vertically moving vibrator and a horizontally moving vibrator to obtain rotational force. Since the vibrator is placed in a separate location, the structure is complicated and large.

Purpose The present invention was made in view of the above-mentioned circumstances.
In particular, the purpose of this invention is to provide an ultrasonic motor that is efficient, has a simple structure, and is easy to downsize.

In order to achieve the above object, the present invention provides a piezoelectric vibrator that causes thickness sliding displacement and a piezoelectric vibrator that causes thickness direction displacement or longitudinal potential, which are connected in series, and both ends are fixed. It is characterized by

Hereinafter F1 will be explained based on an embodiment of the present invention 6 Fig. 1 is a configuration diagram for explaining an embodiment of the present invention, in which 1 is a longitudinal displacement vibrator, 2 is a sliding direction displacement A vibrator, 3 is an insulator, and 4 is a rigid body.

A and B are the electrodes of vibrator 1, D and C are the electrodes of vibrator 2,
As shown in the figure, a longitudinal displacement vibrator 1 and a sliding direction displacement vibrator 2 are fixed to each other with an insulator 3 in between. In addition, 2
The insulator 3 may be omitted if the electrodes of two vibrators do not touch each other. Both ends are fixed to the walls of a rigid body (stator) 4 to prevent movement.

The polarization direction (F,) of the longitudinal vibrator 1 is perpendicular to the electrodes as shown in the figure, and the polarization direction (F2) of the vertical displacement vibrator 2 is parallel to the electrodes.

FIG. 2 is a diagram showing the operating principle, and the B and D electrodes are always grounded. As shown in FIG. 2(a).

When a voltage of +E is applied to the electrode C of the sliding vibrator 2, a deflection occurs and the insulator 3 is pushed upward.

Next, as shown in FIG. 2(b), when voltages of +E and V are applied to the electrode A of the longitudinal vibrator 1, the vibrator 1 extends in the longitudinal direction and moves the insulator 3 to the right.

Next, as shown in FIG. 2(c), when the voltage across the sliding oscillator 2 is cut off, the insulator 3 moves downward. Next, as shown in FIG. 2(d), when the voltage of the longitudinal vibrator l is cut off, the insulator 3
moves to the left and completes one cycle. When the voltage is switched in this way, the upper surface of the insulator 3 moves along the sides of the rectangle or rhombus.

Therefore, when drive elements as shown in FIG. 1 are arranged and a moving element is pressed onto them, the vibrator moves.

Also, if they are arranged in a circle, it is possible to make a rotary motor. In addition, although an example of pulse-wave skating was shown above,
Add a sine wave to electrodes A and C, and set the phase difference between A and C to 90'.
Even if you shift it, it will behave the same way. At this time, by adjusting the length, it is possible to move in a resonant state, and the moving speed can be increased.

Layer 12 As is clear from the above description, according to the present invention, since the vertical motion vibrator and the horizontal motion vibrator can be arranged on the same plane, miniaturization (especially thinning) is facilitated.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing essential components for explaining an embodiment of the present invention, and FIG. 2 is a diagram for explaining the operating principle of the present invention. DESCRIPTION OF SYMBOLS 1... Longitudinal displacement vibrator, 2... Full direction displacement vibrator, 3... Insulator, 4... Rigid body. Figure 1 Figure 2

Claims (1)

[Claims] 1. An ultrasonic motor characterized in that a piezoelectric vibrator that causes thickness shear displacement and a piezoelectric vibrator that causes thickness direction displacement or longitudinal potential are connected in series and both ends are fixed.