JPH04101681A - Ultrasonic motor - Google Patents

Abstract

PURPOSE:To improve availability of space in a motor by employing a hollow bolt thereby providing a through-hole. CONSTITUTION:A hollow tightening bolt 7 is employed. In other words, a retaining flange part 20 is provided at one end of the bolt 7 whereas an external thread 19 to be screwed by a nut 8 is provided at the other end and a through- hole 17 is made in the center over the entire length. When the tightening bolt 7 is inserted into through-holes 11-16 of a torsional oscillator 21 or a rotor 6 and the nut 8 is screwed to the external thread 19 of the bolt 7 to assemble a motor, a through-hole 17 is provided in the center of the motor. The through- hole can be utilized as a space for passing a cord.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ultrasonic motor that outputs rotational force using ultrasonic vibration energy.

[Background Art] FIG. 3 shows an exploded perspective view of a conventional ultrasonic motor C using a bolted Langevin type piezoelectric vibrator and a torsion coupler. A piezoelectric vibrator 50 is constructed by stacking piezoelectric elements 41 on both sides of an electrode plate 42 and sandwiching the piezoelectric elements 41 between aluminum blocks 43 and 44 from both sides. 45 are stacked, a rotor 46 is stacked on the torsion coupler 45, a tightening bolt 48 is inserted through a hole drilled in the center of each of these members, and a nut 49 is screwed onto the bolt 48 via a spring 47. The clamping force of this bolt 48 causes the piezoelectric vibrator 5 to
0 is a Langevin type piezoelectric vibrator.

Therefore, due to the action of the torsional coupler 45, a part of the longitudinal vibration generated by the piezoelectric vibrator 50 is converted into flexural vibration, and further, at the contact portion of the torsional coupler 45 with the rotor 46, the flexural vibration is converted into torsional vibration. converted into vibration. The rotor 4G is rotated by the torsional vibration of the torsional coupler 45, and rotational force is output from the ultrasonic motor.

4 and 5 show a partially exploded perspective view and sectional view of a conventional ultrasonic motor D using a bolted Langevin type torsional vibrator and a laminated piezoelectric actuator. The torsional vibrator 21 has metal blocks 3 and 4 arranged on both sides of piezoelectric elements 1 and 2 that have been polarized in the circumferential direction, and the piezoelectric elements 1 and 2 have opposite phases to each other. Excited strain vibration in the circumferential direction. The laminated piezoelectric actuator 5 is bonded to one end of this torsional vibrator 21, and furthermore, on the laminated piezoelectric actuator 5,
The rotor 6 and the presser support 10 are stacked on top of each other. Furthermore, the spring 9 is passed through the tightening ports 57 inserted through the through holes 11 to 16 of the piezoelectric elements 1 and 2, the metal blocks 3 and 4, the rotor 6, and the presser support 10, and the nut 8 is inserted into the male thread 19 of the bolt 57. The internal screws 18 of the bolts 57 and nuts 8 are screwed together and tightened, and the torsional vibrator 21 is clamped by the tightening force of the bolt 57 and nut 8 to form a Langevin type piezoelectric vibrator. It is pressed into contact with the

Thus, the torsional vibration of the torsional vibrator 21 and the longitudinal vibration of the laminated piezoelectric actuator 5 are combined.

Since the period of torsional vibration and the period of longitudinal vibration are synchronized, only torsional vibration in one direction is transmitted to the rotor.
The rotor is rotated.

[Problem to be solved by the invention] However, it is difficult to incorporate an ultrasonic motor into various devices.
When wiring a cord from another electrical system beyond the installation location of the ultrasonic motor, with a bolt-fastened Langevin-type ultrasonic motor that has a tightening port inserted through the center, the bolt will obstruct the cord from entering the motor. I couldn't get it to connect.

Therefore, the cord must be routed outside the ultrasonic motor, and a space for wiring is required around the ultrasonic motor in the housing where the ultrasonic motor is housed, so extra wiring space must be provided. It was necessary, and the space was inefficiently used.

Furthermore, this wiring space hinders miniaturization of the device into which the ultrasonic motor is incorporated, and the cord does not fit well.

[Means for Solving the Problems] The ultrasonic motor of the present invention outputs rotational force using a Langevin piezoelectric vibrator to which a clamping force is applied by a clamping port. The structure is characterized by having a through hole extending through the entire length.

[Function] In the present invention, in an ultrasonic motor using a Langevin piezoelectric vibrator inserted through a tightening port,
Since the tightening port is hollow and has a through hole that penetrates the entire motor, it is possible to route the cord through the motor by passing a separate electrical cord through this bolt.

Therefore, the space inside the motor can be used for wiring, and the efficiency of using the space inside the motor can be improved.

Furthermore, since it can be wired inside the motor, there is no need to provide space around the ultrasonic motor for wiring a separate electrical system cord, which contributes to the miniaturization of equipment in which the ultrasonic motor is installed. By wiring the cord, the cord will fit better.

[Example code] Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

What is shown in FIG. 1 is an embodiment of an ultrasonic motor A using a sliding vibrator 21 and a laminated piezoelectric actuator 5. In FIG. The structure of this ultrasonic motor A is the same as that of the conventional ultrasonic motor D shown in FIGS. 4 and 5, except for the structure of the tightening port 7, so the structure is the same as that of the conventional ultrasonic motor D. The same reference numerals are given to the same reference numerals, and a detailed explanation thereof will be omitted. In this embodiment, the tightening bolt 7
However, as shown in FIG. 1, it has a hollow shape.

That is, a flange 20 for preventing removal is provided on the outer periphery of one end of the bolt 7, and a brochure screw 19 for screwing with the nut 8 is threaded on the outer periphery of the other end. A through hole 17 is bored through the entire length. Then, this tightening port 7 is connected to the torsion vibrator 2.
1 and rotor 6, etc., and bolt 7
When the motor is assembled by screwing the nut 8 onto the male thread 19 of the
7 is formed. Therefore, this through hole 17 can be used as a space for passing a cord or the like.

What is shown in FIG. 2 is a cross-sectional view of a small manipulator B having a built-in ultrasonic motor, and a pair of ultrasonic motors Al and A2 are housed in a housing 32 with a telescopic portion 31 in between. The telescopic part 31 is the output shaft 3 of the ultrasonic motor A2.
3, and when the telescoping section 31 is driven by the ultrasonic motor A2 to extend or contract, the portion to the left of the telescoping section 31 in FIG. 2 moves in the α direction. The cord 34 of the ultrasonic motor A1 is routed toward the control unit and the like through a space (not shown) in the extensible portion 31 and a through hole 17 of the ultrasonic motor A2. Therefore, ultrasonic motor A
There is no need for space for wiring around housing 3.
The manipulator B can be made thinner by making the inner diameter of the ultrasonic motors Al and A2 equal to the outer diameters of the ultrasonic motors Al and A2. Note that 35 is the code of the ultrasonic motor A2.

In the above embodiment, the type of ultrasonic motor corresponding to the conventional example shown in FIGS. 4 and 5 was explained, but the third embodiment
In an ultrasonic motor of the same type as the conventional example shown in the figure, a through hole may be formed over the entire length of the tightening bolt so that a cord can be wired through the through hole.

[Effects of the Invention] According to the ultrasonic motor of the present invention, it is possible to wire a separate electrical cord to the through hole of the tightening bolt. Therefore, the space inside the motor can be used for wiring. Improves space usage efficiency.

Furthermore, since it can be wired inside the motor, there is no need to provide space around the ultrasonic motor for wiring a separate electrical cord, making it possible to further downsize the equipment in which the ultrasonic motor is incorporated. By wiring the cord inside the motor, the cord can be stored better.

Furthermore, even if there is a limit to the space in which the ultrasonic motor is installed, the cord can be routed inside the ultrasonic motor, making it easier to incorporate the ultrasonic motor and making it easier to design a compact device.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a schematic sectional view of a manipulator incorporating the same ultrasonic motor, FIG. 3 is an exploded perspective view of a conventional example, and FIG. FIG. 5 is a partially exploded perspective view showing another conventional example, and FIG. 5 is a sectional view of the same. 5...Laminated piezoelectric actuator 7...Tightening bolt 21...Piezoelectric vibrator 17...Through hole

Claims (1)

[Claims] (1) In an ultrasonic motor that outputs rotational force using a Langevin-type piezoelectric vibrator that is applied with a clamping force by a tightening bolt, the bolt has a hollow structure to provide a through hole that runs through the entire length. An ultrasonic motor characterized by: