JPS62193577A - Ultrasonic motor - Google Patents

Abstract

PURPOSE:To enable the rotational angle of a rotor to be exactly determined without oscillation loss, by providing a part of an oscillator with holes or grooves, and by inserting pins or sheets into the holes or the grooves to fix the position of the oscillator. CONSTITUTION:An oscillator 1 consists of the main unit 2 of the oscillator and a piezoelectric unit 3, and voltage is applied to the piezoelectric unit 3, and the oscillator 1 is vibrated, to be a driving power source. On the upper section of the oscillator 1, a rotor is rotatably set. On the upper section of the oscillator 1, a plurality of grooves 2a are arranged. The rotation of the oscillator 1 is stopped by inserting stationary sheets 6a set on a stationary unit 6, into the grooves 2a.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to an ultrasonic motor using ultrasonic vibration as a driving source.

2. Description of the Related Art An ultrasonic motor that utilizes ultrasonic vibration consists of a vibrating body serving as a driving source and a rotor provided above the vibrating body. By extracting an external force from the rotor provided at the top, the vibrating body receives a force in a direction opposite to the moving direction of the rotor as a reaction.

The vibrating body of an ultrasonic motor does not come into contact with any other medium other than the rotor to extract external force because energy escapes to the outside through the contact surface and the existence of the contact surface hinders vibration. things are desirable. However, unless the reaction force is prevented, it will be impossible for the rotor to extract power from the rotor.

Conventionally, a material that does not inhibit vibration, such as rubber or felt, is placed on the bottom of the vibrating body, and rotation is prevented by the frictional force between the felt and the vibrating body.

Generally, ultrasonic motors are characterized by low speed rotation and high torque, so the above-mentioned fixing methods are insufficient, and methods of fixing with adhesives such as silicone rubber have been used.

The above-mentioned method has drawbacks such as low reliability, increased loss of the vibrating body, and failure to improve the accuracy of rotor movement, so there has been a demand for an improvement in the fixing method.

Problems to be Solved by the Invention An object of the present invention is to improve the method of fixing a vibrating body in an ultrasonic motor, and to enable accurate determination of the rotation angle of the rotor without vibration loss. .

Means for Solving the Problems In an ultrasonic motor consisting of a vibrating body using a piezoelectric material and a rotor driven in contact with the vibrating body, a hole or groove is provided in a part of the vibrating body, and the hole or groove is The position of the vibrating body is fixed by inserting a bottle or plate from the outside.

Function If the above-mentioned fixing structure is used, since the pin contacts only a small part of the vibrating body, the vibration of the vibrating body is not prevented in any way, and the position cannot be securely fixed in the circumferential direction. It is possible.

Example Figure 2 shows the basic configuration of an ultrasonic motor.

The vibrating body 1 in the figure consists of a vibrating body main body 2 and a piezoelectric body 3, and a voltage is applied to the piezoelectric body 3 to vibrate the vibrating body 1 and use it as a driving force source. Furthermore, the rotor 4 provided on the upper part of the vibrating body 1 is rotated left and right, and an output is taken out from the shaft 4&. Further, a holder 5 (
mechanical stator).

As shown in detail in FIG. 1, a plurality of grooves 2a are provided in the upper part of the vibrating body 1. By inserting a fixed plate 6a provided on the fixed body 6 into the groove, the rotation of the vibrating body 1 is stopped.

The fixed body 6 is fixed to the holder 6 shown in FIG. 2, for example.

The fixed plate 6a is made of a material whose properties are mechanically contradictory to the material of the vibrating body 2, such as metal, such as plastics or hard rubber.

It must be made of reinforced plastic.

If it is made of metal or the like, the vibration contact noise will be large and contact vibration wear will occur. If the number of vibrating pieces is too large, the vibration of the vibrating body 1 will be reduced, so it is necessary to minimize the number of vibrating pieces. According to experiments, four sheets were sufficient to prevent the problem.

It is also necessary to pay sufficient attention to the mechanical precision of the grooves and plates of the vibrating body 1. If the gap is too large, the rotation precision of the rotor 4 will be reduced, and if the gap precision is small, the vibrator will come into contact and reduce the efficiency of the vibrator. Accuracy of 0.1 mm or less is required.

Here, the vibrating body 1 and the rotor 4 need to be pressed against each other, but this pressing force can be achieved, for example, by configuring either one of them with a magnet and magnetically coupling them using magnetic attraction force. Configure it so that you can get it.

Furthermore, it is not limited to a groove as shown in FIG. 1, but may also be a hole as shown in FIG. In the configuration example shown in FIG. 3, the vibrating body 7 has a hole 7a.
is provided, and a fixing pin (not shown) is inserted into this to fix it. It is desirable that the hole 7a be provided on a so-called neutral plane 8 that neither expands nor contracts when the vibrating body vibrates.

Note that the above embodiments have been shown for rotary motors, but
The present invention is similarly applicable to the case of IJ near motors.

Effects of the Invention By using the vibrating body fixing method according to the present invention, the number of parts can be reduced in the ultrasonic motor configuration.

Improved reliability: 2) Improved rotational angle accuracy is obtained, and the practical effect is significant.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view of essential parts of an ultrasonic motor in one embodiment of the present invention, FIG. 2 is an exploded perspective view showing the configuration of the ultrasonic motor, and FIG. 3 is a perspective view of another embodiment of the present invention. It is. 1... vibrating body, 2... vibrating body main body, 2
a...Groove, 3...Piezoelectric body, 4...
...Rotor, 5...Holder, 6...Fixed body, 6a...Fixed plate. Figure 1 Figure 3

Claims (5)

[Claims] (1) In an ultrasonic motor consisting of a vibrating body using a piezoelectric material and a rotor driven in contact with the vibrating body, a hole or groove is provided in a part of the vibrating body, and a pin is inserted into the hole or groove. Alternatively, an ultrasonic motor characterized in that the position of the vibrating body is fixed by inserting a plate-shaped fixing means. (2) The ultrasonic motor according to claim 1, characterized in that a hole or groove is provided near a location where the vibration of the vibrating body is least. (3) The ultrasonic motor according to claim 1, wherein holes or grooves are provided perpendicularly to the sliding surface of the vibrating body and the rotor in contact with the vibrating body. (4) The ultrasonic motor according to claim 2, wherein the holes or grooves are provided on the neutral surface of the vibrating body. (5) A large number of grooves are provided on the top surface of the vibrating body (the surface in contact with the stator), and a plate for fixing the motor is inserted into the grooves.
2. The ultrasonic motor according to claim 1, further characterized in that either the vibrator or the rotor is made of a magnet and are connected to each other by magnetic coupling force.