JPH03178573A - Ultrasonic linear motor - Google Patents

Abstract

PURPOSE:To move an element to be moved over the length of a movable driver by moving the driver in the traveling direction of a traveling wave in a contact part with a stationary base, and moving the element to be moved by the driver in the same direction as the traveling direction. CONSTITUTION:When a traveling wave of a circumferential direction indicated by an arrow D is generated on the surface of a movable driver 2, the driver 2 is moved in the traveling direction D of a traveling wave at the contact part with a stationary base 1 by reaction force, and an element 4 to be driven is moved in the same direction as the moving direction of the driver 2 by the wave at the contact part of the driver 2 with the element 4 to be driven. That is, the driver 2 is moved to one end side of the base 1 from the state before driving, and the element 4 to be driven is moved at a distance of the sum of the distance moved by the wave of the driver 2 and the moving distance of the driver 2. The moving speed of the element 4 to be driven at this time is twice as fast as the moving speed of the driver 2 as added to the speed of the driver 2 moved by the wave.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an ultrasonic linear motor that generates a traveling wave by the piezoelectric action of a piezoelectric element and moves a driven object using the traveling wave.

(Prior Art) The principle of a so-called ultrasonic motor will be explained with reference to FIG. When a traveling wave is generated, a rotating force is generated at the contact portion with the driven body 12 in the direction of arrow B, causing the driven body 12 to move in the traveling wave direction A.
and move it in the opposite direction C.

A conventional example of a near motor using this principle is shown in FIG. 7, in which a driving body equipped with a piezoelectric element is configured as a fixed driving body 21, and a driven body 22 is movably mounted on the fixed driving body 21. The driven body 22 is moved over the length range of the fixed driving body 21.

(Problems to be Solved by the Invention) However, in the above conventional example, the fixed driving body 21 is required to have a length equal to the moving range of the driven body 22, which requires a large number of expensive piezoelectric elements, leading to an increase in manufacturing costs. Furthermore, there is a problem in that the moving speed of the driven body 22 is also limited to the speed of the traveling wave of the fixed driving body 21.

It is an object of the present invention to reduce manufacturing costs by reducing the amount of piezoelectric elements by making it possible to move the driven body over the length of the driving body, and to reduce manufacturing costs by reducing the traveling wave velocity of the driving body.
An object of the present invention is to provide an ultrasonic linear motor capable of moving a driven object at twice the speed or more.

(Means for Achieving the Object) In order to achieve the above object, the present invention is configured as follows.

That is, the present invention provides: a fixed base, which is disposed on the fixed base, generates traveling waves in mutually opposite directions at a contact part with the fixed base and other parts due to piezoelectric action, and prevents contact with the fixed base. a movable driving body that is movable in the traveling direction of the traveling wave at the contact portion; a driven body that is moved in the same direction as the moving direction of the movable driving body by the traveling wave at the contact portion with the movable driving body; It consists of

(Function) In the present invention, the movable driving body generates traveling waves in opposite directions at the contact portion between the fixed base and the driven body through piezoelectric action, and the movable driving body generates traveling waves in the opposite directions at the contact portion with the fixed base. The movable drive body moves the driven body in the same direction.

Therefore, the driven object moves a distance equal to the distance moved by the traveling wave of the movable driver plus the moving distance of the movable driver, and the moving speed of the movable driver is equal to the speed traveled by the traveling wave of the movable driver. move at the combined speed of

(Example) Below, an ultrasonic linear motor according to an example of the present invention will be described with reference to the drawings.

First, a first embodiment will be described with reference to FIGS. 1 to 3.

Referring to FIG. 1, a plurality of cylindrical movable drive bodies 2 are arranged on a fixed base 1 in a line in the moving direction of a driven body, which will be described later. This movable drive body 2 has a built-in piezoelectric element (the path shown in the figure), and generates a traveling wave in the circumferential direction on the surface of the movable drive body 2 by piezoelectric action. 3 is a code.

A driven object (in this example, a movable table) is placed on the movable driving body 2.
4 is placed.

The embodiment configured as described above operates as follows.

Referring to FIG. 2, when a traveling wave in the circumferential direction shown by the arrow is generated on the surface of the movable driver 2, the movable driver 2 moves in the traveling direction of the traveling wave at the contact portion with the fixed base 1. The upper driven body 2 is fixed in FIG. 6 because it is moved by the reaction force,
This is a case where the driving body 11 is movable. ), the driven body 4 is moved in the same direction as the moving direction of the movable drive body 2 by the traveling wave at the contact portion between the movable drive body 2 and the wave body 4.

That is, from the state before driving shown in FIG. 3(a) to the state shown in FIG.
As shown in b), the movable driving body 2 moves to one end side of the fixed base 1, and the driven body 4 moves a distance equal to the distance moved by the traveling wave of the movable driving body 2 plus the moving distance of the movable driving body 2. do. Moreover, the moving speed of the wave body 4 at this time is
The moving speed of the movable driving body 2 is twice as high as the moving speed of the movable driving body 2 due to the traveling wave. When the traveling wave of the movable driving body 2 is reversed, the movable driving body 2 and the driven body 4 move to the other end side of the fixed base 1, as shown in FIG. 3(C).

The structure of the movable drive body 2 is not limited to the cylindrical shape as in the above embodiment.

For example, as shown in FIG. 4(a), a plate-shaped movable driving body 2
b, or as shown in FIG. 4(b), a plurality of rectangular prism-shaped movable drive bodies 2C are moved in opposite directions at the contact portions between the movable drive bodies 2b, 2c, the driven body 4, and the fixed base 1. Even if waves are generated, the same effects as in the first embodiment can be obtained.

In addition, in the embodiment shown in FIGS. 5(a) and 5(b), the first fixed base 1, the ↓th movable drive body 2, the second fixed base 5, the second movable drive body 6, and the driven body 4 It is composed of polymerized and arranged
As shown in FIG. 5(b), the first movable driver 2 moves with respect to the fixed base 1 of the second work, the second movable driver 2 moves the second fixed base 5, and the first movable driver 2 moves with respect to the fixed base 1 of the second work. The second movable drive body 6 moves relative to the second fixed base 5, and the driven body 4 is moved by the second movable drive body 6. That is, by configuring in multiple stages, both the moving distance and moving speed of the driven object can be further increased.

(Effects of the Invention) As explained above, the present invention allows the movable drive body to move in the direction opposite to the traveling direction of the traveling wave at the contact portion with the fixed base,
At the same time, in order to move the driven body in the same direction as the moving direction of the movable driving body by the traveling wave of the movable driving body, the driven body is moved by the distance traveled by the traveling wave of the movable driving body plus the moving distance of the movable driving body. The driven body moves a distance, and the driven body moves at a speed equal to the moving speed of the movable driving body and the speed at which it is moved by the traveling wave of the movable driving body. That is, it is possible to move the driven object beyond the length of the movable driver, reducing the amount of piezoelectric elements, thereby reducing manufacturing costs, and it is possible to move the driven object at a speed exceeding the traveling wave velocity of the movable driver. It becomes possible to move it.

Moreover, by providing the above-mentioned structure in multiple stages, both the moving distance and the moving speed of the driven object can be further increased.

[Brief explanation of drawings]

FIG. 1 is a perspective view of the first embodiment of the present invention, FIG. 2 is a partially enlarged view of the above embodiment, and FIGS. 3(a), (b), and (c) are operational state diagrams of the above embodiment. 4(a) and 4(b) are front views of other embodiments, FIGS. 5(a) and 5(b) are working state diagrams of still further embodiments, and FIG. 6 is an explanation of the principle of the ultrasonic motor. FIG. 7 shows a conventional example. Fixed base 2, al: Movable drive body code 4: Movable body movable base

Claims (2)

[Claims] (1) A fixed base, which is disposed on the fixed base, and generates traveling waves in opposite directions at the contact part with the fixed base and other parts due to piezoelectric action, and generates traveling waves at the contact part with the fixed base. It consists of a movable driving body that is movable in the direction of movement of waves, and a driven body that is moved in the same direction as the moving direction of the movable driving body by the traveling waves at the contact portion with the movable driving body. An ultrasonic linear motor characterized by: (2) An ultrasonic linear motor characterized in that the ultrasonic linear motor according to claim 1 is formed in multiple stages.