JP2898464B2 - Ultrasonic motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic motor for generating a rotational driving force using an electrostrictive vibrator.

[0002]

2. Description of the Related Art An ultrasonic motor has a very high electro-mechanical conversion efficiency and can generate a large driving torque even at a low speed. Above all, composite oscillator type ultrasonic motors that stably generate rotational torque even at low speed and are easy to control are expected to be used in various fields.

Conventionally, as one example of the structure of this type of ultrasonic motor, an ultrasonic motor having a structure shown in FIG. 2 has been known.
The ultrasonic motor 12 shown in FIG. 2 has a stator 24 in which a stator bottom 22, an annular torsional vibrator 20, a hollow stator holder 18, an annular vertical vibrator 16 and a hollow stator head 14 are connected by a center bolt 25. And the rotor 26. The rotor 26 is supported by a center bolt 25 via a bearing 35 and is connected to the stator 24. The stator 24 and the rotor 26 are connected to each other in a sliding state. A friction material is interposed between the stator 24 and the rotor 26. The center bolt 25 has a spring member 28 locked by a first spring receiver 29 and a second spring receiver 30.
, And the spring member 28 presses the rotor 26 against the stator head 14 via a friction material. The second spring receiver 30 is locked by a nut 10 via a washer 34, and reference numeral 36 is a washer.

[0004] In the ultrasonic motor 12 having the above structure,
The torsional vibrator 20 generates a rotational driving force for the rotor 26, and the vertical vibrator 16 controls the contact between the stator 24 and the rotor 26. That is, when a voltage is applied to the torsional vibrator 20 while the stator head 14 and the rotor 26 are pressed and touched by the spring force of the spring member 28, the torsional vibrator 20 rotates the rotor 26 by a small angle due to the torsional force. After the rotation, the rotor 26 is
When the pressing force on the stator head 14 is reduced,
The amount of torsion of the torsional vibrator 20 is canceled out and disappears. Here, when a voltage is applied to the torsional vibrator 20 again, the rotor 2
6 rotates again by a small angle. The rotor 26 can be continuously rotated in a fixed direction by repeatedly performing the elliptical motion including the combination of the vibration of the torsional vibrator 20 and the vibration of the longitudinal vibrator 16. High torque is easily obtained and the driving noise is quiet.

[0005] Then, by forming spokes or the like on the rotor 26 and connecting the rotor 26 to an object requiring a rotational movement, the rotational force of the ultrasonic motor 12 can be effectively taken out and used.

[0006]

Generally, an ultrasonic motor is a low-noise, quiet, high-quality motor. However, the bearing 35, washer 36, spring receiver 29, and the like, also made of metal, come into contact with the center bolt 25, which is metal, and rub against each other when driven. In addition, since the ultrasonic motor is driven by using the longitudinal vibration and the torsional vibration, the center bolt 25 is inevitably small, but vibrates in the longitudinal direction according to the generated longitudinal vibration and torsional vibration, or Vibration tilted with respect to the direction was caused. Due to these complicated vibrations of the center bolt, noise is generated between the center bolt 25 and various metal parts in contact with the center bolt 25. Such noise hinders the high quality of the ultrasonic motor, which is quiet. Furthermore, the contact between the vibrating center bolt 25 and various metal parts causes abnormal wear of these center bolts and other parts. This abnormal wear not only causes uneven rotation of the motor, but also reduces the durability of the ultrasonic motor.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide an ultrasonic motor which suppresses noise generated from a center bolt, has high silence, and has high durability.

[0008]

The ultrasonic motor of the present invention, in order to solve the problems], said a cylindrical stator having a longitudinal vibrator with torsional vibrator at integrated center bolt stator center
The bolt is rotatably supported around the circumference of the bolt , and is rotatably pressed against the end of the stator to be connected to the stator.
In the ultrasonic motor provided with the annular rotor, the
The center bolt is located between the rotor and the center bolt.
Allow rotation of the rotor in the circumferential direction and allow the rotor
It is characterized in that a cylindrical collar made of a resin that comes into contact is provided . Further, the ultrasonic motor of the present invention
The ultrasonic motor according to claim 1, wherein the center bolt is
A washer, a spring receiver, the washer and the spring receiver
Press the rotor against the front of the stator via
At least a spring member is inserted and the resin collar
However, in addition to the inside of the rotor, the washer and the
It is noted that it was extended between the support and the center bolt.
Sign.

[0009]

According to the ultrasonic motor of the present invention, the center bolt, which is a noise source at the time of driving, and the rotor and the wire that rub against the center bolt are used.
A resin collar is interposed between metal parts such as a washer and a spring receiver . This prevents the center bolt and these metal parts from directly rubbing each other, and the center bolt and the metal parts vibrated during driving. As
Relatively large noise generated when metals rub against each other is not generated.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIG. The same members as those of the conventional ultrasonic motor shown in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted.

An ultrasonic motor 41 shown in FIG. 1 includes a stator bottom 22, an annular torsional vibrator 20, a hollow stator holder 18, an annular longitudinal oscillator 16, and a stator head 14.
And a stator 24 continuously connected by a center bolt 25,
And a rotor 26. The rotor 26 is rotatably supported by a center bolt 25 via a bearing 35 and is connected to the stator 24. The center bolt 25 is locked by a first spring receiver 29 and a second spring receiver 30 .
A spring member 28 is mounted, and the spring member 28 presses the rotor 26 against the stator head 14 via a friction material 40. Therefore, the rotor 26 is pressed against the stator 24 and is slidably rotated. Reference numeral 36 is Ri washer der interposed between the bearing 35 and the first spring bearing 29, the spring member 28, the washer 36
And presses the rotor 26 through the first spring receiver 29.
It is configured as follows. The ultrasonic motor 41 can be supported and fixed by fixing a flange 32 provided at a node of torsional vibration.

In the ultrasonic motor of the present invention, a collar 38 is mounted on the center bolt 25.
The collar 38 includes at least the center bolt 25 and the rotor 2.
6 between the bearing 35 and
I have. The collar 38 is cylindrical and has a center bolt 2 inside.
5 is of a size to be inserted. For example, if the center bolt 25 has a diameter of 5 mm, the inner diameter is 5 mm.
mm, a thickness of 0.5 mm and an outer diameter of 6 mm can be used. (In this case, the inner diameter of the bearing 35 is 6 mm.) The material of the collar 38 is excellent in heat resistance and wear resistance.
A material with low elasticity can be applied. For example, polyacetal (specifically, Duracon: Polyplastics Co., Ltd.
), A fluorinated resin (specifically, Teflon: manufactured by DuPont-Mitsui Fluorochemicals Co., Ltd.), a phenol resin such as Bakelite, and various resins such as polyethylene, polyamide, and polyimide.

In the ultrasonic motor 41 having the above structure, the torsional vibrator 20 generates a rotational driving force for the rotor 26,
The vertical vibrator 16 controls the contact between the stator 24 and the rotor 26. That is, when a voltage is applied to the torsional vibrator 20 in a state in which the stator head 14 and the rotor 26 are in press contact with the spring force of the spring member 28 , the torsional vibrator 20 causes the rotor 26 to become minute by the torsional force. Rotate an angle. After the rotation, the rotor 26 is
When the pressing force on the stator head 14 is reduced,
The amount of torsion of the torsional vibrator 20 is canceled out and disappears. Here, when a voltage is applied to the torsional vibrator 20 again, the rotor 2
6 rotates again by a small angle. By repeatedly performing the elliptical motion including the combination of the vibration of the torsional vibrator 20 and the vibration of the longitudinal vibrator 16, the rotor 26 can be continuously rotated in a fixed direction, and a high torque can be easily obtained even at a low speed. it can. Moreover, in the case of the ultrasonic motor 41 of this embodiment, the center bolt 25 and the bearing 3
Since the collar 38 is interposed between the members 5, the center bolt 25 and the bearing 35, both of which are made of metal, do not come into direct contact with each other. Has features. Further, even if the center bolt 25 causes longitudinal vibration or tilts and vibrates, the center bolt 25 and various metal parts such as the bearing 35 do not directly rub against each other. Does not occur. Therefore, rotation unevenness due to abnormal wear does not occur, and the durability performance of the ultrasonic motor 41 is improved.

Since the collar 38 prevents direct contact between the center bolt 25 and the metal part, the collar 38 covers not only the entire side surface of the center bolt 25 but also at least the bearing 35 and the center bolt. It suffices if it is interposed between 25. This is because the center bolt 25 and the bearing 35 to which the vibration from the rotating rotor 26 is directly rubbed are the most rubbed. Therefore, even if the collar 38 is interposed between the center bolt 25 and the bearing 35, sufficient quietness can be obtained. This is because it can be increased. Further, in addition to the center bolt 25 and the bearing 35, the collar 38 is provided with a washer 36 and the first spring receiver 2.
A remarkable effect can be obtained only by interposing between them.

[0015]

According to the ultrasonic motor of the present invention, there are provided a center bolt , a rotor which is a metal part which rubs against the center bolt ,
Since a resin collar is interposed between the washer and the spring receiver , it is possible to suppress the generation of noise that occurs when metals rub against each other. Therefore, the ultrasonic motor of the present invention has high silence and high quality. Therefore,
The ultrasonic motor of the present invention is particularly excellent as a motor for winding curtains and blinds, which is required for its quietness. In particular, since the center bolt and the metal parts that rub against the center bolt do not directly rub against each other, abnormal wear does not occur on the parts such as the center bolt, so that not only rotation unevenness does not occur but also durability performance is improved.

[Brief description of the drawings]

FIG. 1 is a partially exploded perspective view of an ultrasonic motor according to the present embodiment.

FIG. 2 is a side view of a conventional ultrasonic motor.

[Explanation of symbols]

12 Ultrasonic Motor 16 Vertical Vibrator 20 Torsional Vibrator 24 Stator 25 Center Bolt 26 Rotor 28 Spring Member 29 First Spring Bearing (Spring Bearing ) 30 Second Spring Bearing 35 Bearing 38 Collar 41 Ultrasonic Motor

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-184166 (JP, A) JP-A-2-211075 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) H02N 2/00

Claims (2)

(57) [Claims] 1. A cylindrical stator having a vertical vibrator and a torsional vibrator, and a center bolt integrated with the stator, which is rotatably supported around the center bolt .
One, the ultrasonic motor and a circular rotor which stator and continuously provided is rotatably pressure contact with the end portion of the stator, said between said rotor and said center bolt Sentaboru
To allow rotation of the rotor in the circumferential direction of the rotor.
An ultrasonic motor comprising a resin-made cylindrical collar in contact with a motor. 2. The center bolt has a washer and a bar.
And the spring through the washer and the spring receiver.
And a spring member for pressing the rotor against the front portion of the stator.
Inserted at least, The resin collar, in addition to the inside of the rotor,
Between the washer and the spring bolt and the center bolt
The ultrasonic mode according to claim 1, wherein the ultrasonic mode is extended.
Ta.