JPS6077683A - Flat motor using curved piezoelectric actuator - Google Patents

Abstract

PURPOSE:To flatten the entire motor by bending a thin piezoelectric plate having electrodes on both side surfaces, engaging fixedly a ring frame, resonating the frame and rotating a wheel. CONSTITUTION:A piezoelectric plate 1 of disc shape formed with electrodes on both front and back side surfaces is bent and deformed, engaged with a ring- shaped frame 2, bonded fixedly at the periphery, thereby forming a bent piezoelectric actuator. The frame 2 of the actuator is engaged along the inner periphery of the wheel 3. A rotary supporting plate 8 having a rotational shaft 4 is bonded fixedly onto the upper surface of the frame 2, and a case plate 9 is covered on the upper and lower surfaces of the wheel 3. The shaft 4 and the plate 9 are electrically connected to the electrodes of the plate 1. When an AC voltage is applied therebetween, the wheel 3 is rotated, thereby obtaining a large rotary torque from a pulley 5.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in motors, and an object of the present invention is to provide a piezoelectric motor that has a flat plate shape that can be conveniently accommodated in equipment and consumes less power.

Conventional motors have a mechanism that converts the interaction between the magnetic poles, which occurs when current flows through the magnetic poles of the cylindrical rotor and stator, into rotational force. , and the length of the cylinder in the axial direction was required to obtain rotational torque.

Since the ultrasonic vibrator has a cylindrical shape, it has been difficult to flatten the entire motor. As devices become lighter, thinner, shorter, and smaller, the need for flat plate motors is increasing, and finding solutions to these needs has become an important technical issue.

This invention solves the above-mentioned conventional technical problem. A piezoelectric thin plate having electrodes on both the front and back surfaces is bent and fixed to fit into a ring-shaped frame, and an alternating current signal applied between the electrodes is used to This purpose was achieved by a curved piezoelectric actuator that causes its body to resonate in the radial direction and rotates a ring whose conduit is a buckling spring fitted to the diameter of a frame body.

Embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1 FIGS. 1 and 2 show an embodiment of a parallel motor using a curved piezoelectric actuator according to the present invention. A piezoelectric plate 1 made of Pb(ZrTi)O3-based ceramic, which is a disk with a diameter of 40 nm and a thickness of 0.5 m and is polarized with electrodes on both the front and back sides, is used as a decoy with a radius of curvature R, and a ring with an outer diameter of 44 m and a thickness of 2 fi. The curved piezoelectric actuator was made by fitting into the shaped frame 2 and fixing the periphery with adhesive. Outer diameter 60m
The frame 2 of the piezoelectric actuator is curved along the inner diameter of the radial ring 3, which has an inner diameter of 56 xx and a radial blade 31 with a width of 2, a length of 6 tm, and a thickness of 1 u. were fitted. The radial blade 3□ is bent and deformed along the inner diameter in one direction, either counterclockwise or clockwise. The upper surface of the actuator frame 2 has a distance of 43 ψ, 0.
A rotary support plate 8 having a rotary shaft 40 was adhesively fixed to the center of a disk having a thickness of 5 sm. A case plate 9 was placed over the upper and lower surfaces of the ring 3, the rotation shaft 4 was passed through an insulating bushing, and a pulley 5 was attached. The rotating shaft 4 and the case plate 9 are electrically connected to two electrodes of the piezoelectric plate 1, and 17KH is applied between them.
When a swirling voltage of g and 10 ports is applied, the spiral ring 3 moves at 4 per second.
We were able to create a flat plate motor that rotates at high rotational speed and can obtain large rotational torque from pulley 5.

Example 2 In Example 1, the outer circumference of the flat plate motor was too thick, so an example in which the outer diameter was downsized to 50 mψ is shown in Figure 2. The curved piezoelectric actuator is the same as in Example 1. However, a conical ring 3 with an outer diameter of 40 fl and a thickness of 2 mm was inserted into the concave side of the piezoelectric plate 1. The 31012 conical blades had an outer diameter of 28 fl,
A radial ring 3 with a thickness of 2 m and a rotating shaft 4 fixed vertically at the center.
The blades are attached radially, and the tips of the blades are all slightly bent in one direction. Since the radial blades 31 are in firm contact with the inner periphery of the ring-shaped frame 2 of the actuator, considerable friction is generated to rotate the radial ring 3. The actuator and the ring 3 are housed in a case 10, and the convex center of the actuator is placed in the case 1 through a rubber sheet cushion.
0, the gear 11 was attached to the rotating shaft 4, and an AC voltage of 17 KH, 10 volts was applied between the lead wires 6 and 7. The flat plate motor rotated at a speed of about 4 revolutions per second, and the gear 11 was attached to the rotating shaft 4. 11, a large rotational torque was obtained.

As explained above, the piezoelectric thin plate, which has voltages on both the front and back sides, is bent and deformed and fitted and fixed to the ring frame, and the AC voltage applied between the electrodes causes the frame to resonate in the radial direction. By using a structure that rotates a wide wheel whose conduit is a crimped buckling spring, we were able to create an extremely thin and light motor. The piezoelectric motor of the present invention rotates at a low speed of several hundred r, p, m, while
The rotational torque is large, and the rotation speed starts with little fluctuation.
It is a useful motor that exhibits characteristics that are essentially different from conventional motors, such as the response being so fast that stops feel discontinuous and no inertial response observed at all.

Note that the term buckling spring used in this specification refers to a spring body that vibrates in a bending mode when a flat plate is bent and deformed in advance and is subjected to an elastic force in the longitudinal direction. This is a general term for springs that vibrate in a bending mode, since the same effect can be obtained even with springs that vibrate in a bending mode when an elastic force is applied to the spring, which is placed diagonally to the direction of the bending direction.

[Brief explanation of the drawing]

FIG. 1 is a cross section illustrating an embodiment of a flat plate motor using a curved piezoelectric actuator according to the present invention.
9 M t-+ i2 +fsX+2. tliFz A
trz −匍ff+? ;';li! 71 ``Figure 113 is a sectional view of a flat plate motor showing another embodiment of the present invention, and Figure 4 is a partial plan view of the flat plate motor. 1...Piezoelectric plate, 2... ...Frame, 3...
...Width, 4...Rotation axis. Figure 1 Figure 4

Claims (1)

[Claims] A piezoelectric thin plate having electrodes on both the front and back surfaces is bent and fixed to a ring-shaped frame, and an alternating current voltage is applied between the electrodes.
A flat plate motor using a curved piezoelectric actuator, which causes a frame body to resonate in the radial direction and rotates a ring whose convergence is a buckling spring crimped to the diameter of the frame body.