JPH01252179A - Ultrasonic motor - Google Patents
Ultrasonic motorInfo
- Publication number
- JPH01252179A JPH01252179A JP63076701A JP7670188A JPH01252179A JP H01252179 A JPH01252179 A JP H01252179A JP 63076701 A JP63076701 A JP 63076701A JP 7670188 A JP7670188 A JP 7670188A JP H01252179 A JPH01252179 A JP H01252179A
- Authority
- JP
- Japan
- Prior art keywords
- spring
- ultrasonic motor
- spring constant
- pressurizing
- pressure
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000002783 friction material Substances 0.000 abstract description 17
- 230000003746 surface roughness Effects 0.000 abstract description 8
- 230000000750 progressive effect Effects 0.000 abstract 2
- 238000005299 abrasion Methods 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 5
- 239000000463 material Substances 0.000 description 3
- 238000005452 bending Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000005684 electric field Effects 0.000 description 2
- 230000007774 longterm Effects 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 101000623801 Homo sapiens Protein misato homolog 1 Proteins 0.000 description 1
- 102100023096 Protein misato homolog 1 Human genes 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
Landscapes
- General Electrical Machinery Utilizing Piezoelectricity, Electrostriction Or Magnetostriction (AREA)
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明は圧電体を用いて駆動力を発生する超音波モータ
に関する。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an ultrasonic motor that generates driving force using a piezoelectric material.
従来の技術
近年、圧電セラミック等の圧電体により構成した振動体
に弾性振動を励振し、これを駆動力として移動体を回転
させる超音波モータが注目されている。2. Description of the Related Art In recent years, ultrasonic motors have attracted attention, which excite elastic vibrations in a vibrating body made of a piezoelectric material such as a piezoelectric ceramic, and rotate a moving body using this as a driving force.
以下、図面を参照しながら超音波モータの従来技術につ
いて説明を行う。第6図は円板形超音波モータの断面図
である。振動体3は円板形のステンレス鋼などで作られ
た弾性体1の円板面の一方に、圧電体として円板膨圧電
体2を貼合せて構成している。なお、振動体3は支持体
4に固定されている。移動体7は耐摩耗性材料の摩擦材
6と、ステンレス鋼などで作られた弾性体6を、互いに
貼合せられて構成している。移動体子は、コイルばね8
により、摩擦材6を介して振動体3を加圧接触している
。コイルばね8は止め輪1oによジ設定加圧力を得るよ
うに、設定たわみ量を与えた状態で固定されている。な
お、移動体7に損失なく回転運動を伝えるため、ベアリ
ング9を配置している。圧電体2に交流電界を印加する
と、振動体3の円周方向に進行する曲げ振動の進行波が
励起され、移動体7は、振動体3と摩擦材6の間の摩擦
係数と、前記ばね8による加圧力によって決まる摩擦力
により、駆動され回転する。故に、超音波モータの起動
トルクは前記摩擦力によって決まる。Hereinafter, the conventional technology of an ultrasonic motor will be explained with reference to the drawings. FIG. 6 is a sectional view of the disc-shaped ultrasonic motor. The vibrating body 3 is constructed by laminating a disk expansion piezoelectric body 2 as a piezoelectric body to one of the disk surfaces of a disk-shaped elastic body 1 made of stainless steel or the like. Note that the vibrating body 3 is fixed to a support body 4. The movable body 7 is constructed by pasting together a friction material 6 made of a wear-resistant material and an elastic body 6 made of stainless steel or the like. The moving body is a coil spring 8
As a result, the vibrating body 3 is brought into pressure contact via the friction material 6. The coil spring 8 is fixed with a predetermined amount of deflection so as to obtain a predetermined pressing force on the retaining ring 1o. Note that a bearing 9 is provided in order to transmit rotational motion to the moving body 7 without loss. When an alternating current electric field is applied to the piezoelectric body 2, a traveling wave of bending vibration that advances in the circumferential direction of the vibrating body 3 is excited, and the movable body 7 It is driven and rotated by the frictional force determined by the pressure applied by 8. Therefore, the starting torque of the ultrasonic motor is determined by the frictional force.
従って、前記摩擦係数と加圧力によって決まる摩擦力が
一定であれば、超音波モータは安定な動作をする。しか
し、従来は第7図に示すように、ばね定数がほぼ一定の
コイルばねを加圧用ばねとして用いていた几め、たわみ
量と加圧力は比例関係にあっ友。たわみ量は、初期設定
時の不安定さ及び、回転時における摩擦材6と振動体3
との接触面における、表面粗さやうねりにより設定九わ
み量がその許容領域からはずれることがあり、前記のた
わみ量と加圧力の関係から加圧力許容領域をはずれるこ
ととなり、振動体3と移動体7との加圧力を変化させて
いた。さらに、円周方向に均一に加圧できなかった。そ
の結果、トルク、効率などの特性が得にくかった。また
、超音波モータの長期の動作により、摩擦材6が摩耗し
、コイルばねの初期のたわみ量が小さくなジ、そのため
、加圧力が比例的に変化し、超音波モータの出力が小さ
くなるという欠点があった。Therefore, if the friction force determined by the friction coefficient and the pressing force is constant, the ultrasonic motor operates stably. However, as shown in Figure 7, in the past, a coil spring with a nearly constant spring constant was used as a pressurizing spring, and the amount of deflection and pressurizing force were in a proportional relationship. The amount of deflection is determined by the instability at the initial setting and the friction material 6 and vibrating body 3 during rotation.
The set deflection amount may deviate from the allowable range due to surface roughness or waviness on the contact surface with the vibrating body 3, and the relationship between the deflection amount and the pressurizing force described above may cause the set deflection amount to deviate from the allowable pressurizing force range, and the vibration body 3 The pressurizing force with body 7 was changed. Furthermore, it was not possible to apply pressure uniformly in the circumferential direction. As a result, it was difficult to obtain characteristics such as torque and efficiency. In addition, due to long-term operation of the ultrasonic motor, the friction material 6 wears out and the initial deflection of the coil spring becomes small, which causes the pressing force to change proportionally and the output of the ultrasonic motor to decrease. There were drawbacks.
発明が解決しようとする課題
以上、説明したように従来の超音波モータは、振動体と
移動体の加圧用ばねとして、加圧力許容領域でのばね定
数がほぼ一定のコイルばねを用いていたため、摩擦材の
表面の粗さやうねりおよび摩耗によジ、加圧力が比例的
に変化し、その結果、安定な動作ができないという問題
点があった。Problems to be Solved by the Invention As explained above, conventional ultrasonic motors have used coil springs whose spring constant is approximately constant in the pressurizing force allowable range as springs for pressurizing the vibrating body and the movable body. There is a problem in that the surface roughness, waviness, and wear of the friction material cause the pressing force to change proportionally, resulting in unstable operation.
本発明はかかる点に鑑み、安定な動作をする超音波モー
タを提供することを目的としている。In view of this point, it is an object of the present invention to provide an ultrasonic motor that operates stably.
課題を解決するための手段
振動体と移動体との加圧方法として、加圧力許容領域の
ばね定数が、加圧力許容領域以下のはね定数よジも小さ
いばねを用いて、前記移動体を前記振動体上に加圧接触
して設置することに上り、超音波モータの動作の安定化
をはかる。Means for Solving the Problem As a method of pressurizing the vibrating body and the movable body, a spring whose spring constant in the pressurizing force permissible region is smaller than the spring constant below the pressurizing force permissible region is used to press the vibrating body and the movable body. The ultrasonic motor is placed in pressure contact with the vibrating body to stabilize the operation of the ultrasonic motor.
作用
加圧力許容領域でのばね定数が、加圧力許容領域以下で
のばね定数よりも小さいばねを用いて、前記移動体を前
記振動体上に加圧接触して設置することにより、摩擦材
の表面の粗さやうねりおよび摩耗で、前記はねのたわみ
量が変動しても、前記加圧力の変化を小さくすることに
より、超音波モータの安定な動作を実現する。By using a spring whose spring constant in the applied pressure permissible range is smaller than the spring constant below the applied pressure permissible range, the movable body is placed in pressurized contact with the vibrating body, thereby reducing the friction material. Even if the amount of deflection of the spring changes due to surface roughness, waviness, and wear, stable operation of the ultrasonic motor is realized by reducing the change in the pressing force.
実施例
以下、図面に従って本発明の実施例について詳細な説明
を行う。EXAMPLES Hereinafter, examples of the present invention will be described in detail with reference to the drawings.
(実施例1〕
第1図は、本発明の超音波モータに使用する加圧用はね
の特性図である。ばね定数は同図の特性曲線で示してい
る。加圧力許容領域でのはね定数を、加圧力許容領域以
下でのはね定数よりも小さく設定するために、特性曲線
のゆるやかな傾きを持った部分を利用している。従って
、設定たわみ量が摩擦材の表面の粗さやうねりおよび摩
耗によジ変動しても、振動体と移動体の加圧力の変化は
小さい。第2図(&)にこれを実施するためのさらばね
の平面図、第2図(b)にさらばねの断面図を示してい
る。さらにこのさらばねは、円錐形状のため、円周方向
に均一に加圧することができる。(Example 1) Fig. 1 is a characteristic diagram of the pressurizing spring used in the ultrasonic motor of the present invention.The spring constant is shown by the characteristic curve in the figure. In order to set the constant to be smaller than the spring constant below the allowable pressure range, the part with a gentle slope of the characteristic curve is used.Therefore, the set deflection amount depends on the roughness of the surface of the friction material. Even if the pressure changes due to waviness and wear, the change in the pressing force between the vibrating body and the moving body is small. Figure 2 (&) is a plan view of a platen spring for implementing this, and Figure 2 (b) is A cross-sectional view of the bellows spring is shown.Furthermore, since the bellows spring has a conical shape, pressure can be applied uniformly in the circumferential direction.
第6□□□は、本発明の超音波モータの実施例の断面図
である。振動体3は弾性体1と圧電体2で構成され、移
動体7は弾性体6と摩擦材6で構成される。振動体3は
支持体4で固定されている。圧電体2に交流電界を印加
すれば、振動体3の円周方向に進行する曲げ振動の進行
波が励振され、これを駆動力として移動体7を回転させ
る。さらばね11.11’は第1図に示すように、加圧
力許容領域でのはね定数を、加圧力許容領域以下のばね
定数よりも小さく設定しであるので、設定たわみ量が摩
擦材の表面の粗さやうねりおよび摩耗で変動しても、振
動体と移動体の加圧力の変化は小さく、そのため、超音
波モータの特性変化は小さい。6th □□□ is a sectional view of an embodiment of the ultrasonic motor of the present invention. The vibrating body 3 is composed of an elastic body 1 and a piezoelectric body 2, and the movable body 7 is composed of an elastic body 6 and a friction material 6. The vibrating body 3 is fixed with a support body 4. When an alternating current electric field is applied to the piezoelectric body 2, a traveling wave of bending vibration traveling in the circumferential direction of the vibrating body 3 is excited, and this is used as a driving force to rotate the movable body 7. As shown in Fig. 1, the spring constant of the springs 11 and 11' is set to be smaller than the spring constant in the pressure permissible range below the pressure permissible range, so that the set amount of deflection of the friction material is Even if there are variations due to surface roughness, waviness, and wear, the changes in the pressing force between the vibrating body and the moving body are small, and therefore the characteristics of the ultrasonic motor do not change much.
同図では、加圧力の設定がしやすいように、同特性の嘔
らばねを2枚重ねて、設定たわみ量を太きくしている。In the figure, two springs with the same characteristics are stacked to increase the set deflection amount so that the pressing force can be easily set.
なお、1枚、又は2枚以上複数枚のさらばねを重ねるこ
とも可能である。Note that it is also possible to stack one or more than two bellows springs.
このように、加圧力許容領域のばね定数が、加圧力許容
領域以下のばね定数よりも小さいさらばねを用いて、移
動体を振動体上に加圧接触して設置することにより、摩
擦材の表面の粗さやうねりおよび摩耗で、設定たわみ量
が変動しても、前記710圧力の変化を小さくすること
により、超音波モータの安定な動作を実現している。In this way, by installing the movable body in pressure contact with the vibrating body using a bell spring whose spring constant in the pressurizing force permissible area is smaller than the spring constant below the pressurizing force permissible area, the friction material can be Even if the set deflection amount fluctuates due to surface roughness, waviness, and wear, stable operation of the ultrasonic motor is achieved by reducing the change in the 710 pressure.
(実施例2)
基本構成は実施例1と同様であるが、実施例1で設置し
ている加圧用ばねを、内径部を中心に放射状に複数本の
切り欠きを設けたさらばねに変えて構成したものである
。(Example 2) The basic configuration is the same as in Example 1, but the pressure spring installed in Example 1 was replaced with a bell spring with multiple notches radially centered around the inner diameter. It is composed of
第3図(&)に、本発明の超音波モータに使用する加圧
用ばねの平面図、第3図Φ)に前記ばねの断面図を示し
ている。このように放射状に複数本の切り欠き11aを
設けたさらばねは、円錐形状であり円周方向に均一に加
圧できる。しかも、加圧力許容領域でのたわみ量が、従
来のさらばねに比べて数倍大きくすることができる。FIG. 3(&) shows a plan view of a pressure spring used in the ultrasonic motor of the present invention, and FIG. 3(Φ) shows a sectional view of the spring. The bell spring having a plurality of radial notches 11a has a conical shape and can be pressurized uniformly in the circumferential direction. Furthermore, the amount of deflection in the pressurizing force permissible region can be increased several times compared to conventional bell springs.
第4図は、前記加圧用ばねの特性図である。ばね定数は
同図の特性曲線であり、加圧力許容領域でのばね定数を
、加圧力許容領域以下でのばね定数よジも小さく設定し
である。しかも、前記加圧用ばねは前記切り欠きの効果
により加圧力許容領域のたわみ量が大きくなっている。FIG. 4 is a characteristic diagram of the pressure spring. The spring constant is the characteristic curve shown in the same figure, and the spring constant in the pressurizing force permissible region is set to be smaller than the spring constant below the pressurizing force permissible region. Moreover, the amount of deflection of the pressurizing spring in the pressurizing force permissible region is increased due to the effect of the notch.
そのため、設定たわみ量が摩擦材の表面の粗さやうねり
および摩耗により変動しても、振動体と移動体の加圧力
の変化は小さい。Therefore, even if the set deflection amount changes due to surface roughness, waviness, and wear of the friction material, the change in the pressing force between the vibrating body and the moving body is small.
このように、加圧力許容領域のばね定数が、加圧力許容
領域以下のばね定数よりも小さいさらばねを用いて、移
動体を振動体上に加圧接触して設置することにより、摩
擦材の表面の粗嘔やうねりおよび摩耗で、設定たわみ量
が変動しても、前記加圧力の変化を小さくすることによ
り、超音モータの安定な動作を実現している。In this way, by installing the movable body in pressure contact with the vibrating body using a bell spring whose spring constant in the pressurizing force permissible area is smaller than the spring constant below the pressurizing force permissible area, the friction material can be Even if the set deflection amount fluctuates due to roughness, waviness, or wear on the surface, stable operation of the ultrasonic motor is achieved by reducing the change in the pressing force.
発明の効果 本発明によれば、加圧力許容領域のばね定数が。Effect of the invention According to the present invention, the spring constant in the pressurizing force permissible region is as follows.
加圧力許容領域以下のばね定数よりも小さいさらばねを
用いることにより、摩擦材の表面の粗さおよびうねりや
、超音波モータの長時間動作による摩耗により、前記ば
ねの設定たわみ量が変動しても、振動体と移動体の加圧
力の変化を小さくすることができるので、安定な動作を
する超音波モータを実現できる。By using a bellows spring whose spring constant is smaller than the allowable pressure range, the set deflection amount of the spring may fluctuate due to surface roughness and waviness of the friction material or wear due to long-term operation of the ultrasonic motor. Also, since the change in the pressing force between the vibrating body and the movable body can be reduced, it is possible to realize an ultrasonic motor that operates stably.
第1図は本発明の一実施例の超音波モータに用いるさら
ばねの特性図、第2図e)(b)は同さらばねの平面図
および断面図、第3図(IL)<b)は切欠部を設けた
さらばねの平面図および断面肉、第4図は本発明の超音
波モータに用いる切欠部を設けたざらばねの特性図、第
6図は第1図および第4図に示したばね特性のさらばね
を用いた超音波モータの断面図、第6図は従来例の超音
波モータの断面図、第7図は従来の加圧用はねであるコ
イルばねの特性図である。
1・・・・・・弾性体、2・・・・・・圧電体、3・・
・・・・振動体、4・・・・・・支持体、6・・・・・
・摩擦材、6・・・・・・弾性体、7・・・・・・移動
体、8・・・・・・コイルばね、9・・・・・・Rアリ
ング、1o・・・・・・止め輪、11.11’・・・・
・・さらばね。
代理人の氏名 弁理士 中 尾 敏 男 ほか1名第1
図
たりみ量
第2図
(α)
tb)
If、 /f’−−−さら1;゛ね
第3図 11山−を刃り欠き(aン
(bン
第4図
たわJI−量→
/、6− ロー生体
11.11″−から1よね
第6図
第7図
r:1F)み里Fig. 1 is a characteristic diagram of a bell spring used in an ultrasonic motor according to an embodiment of the present invention, Fig. 2 e) (b) is a plan view and a sectional view of the same bell spring, and Fig. 3 (IL) 4 is a characteristic diagram of a spring with a notch used in the ultrasonic motor of the present invention, and FIG. FIG. 6 is a sectional view of an ultrasonic motor using a bell spring with the spring characteristics shown, FIG. 6 is a sectional view of a conventional ultrasonic motor, and FIG. 7 is a characteristic diagram of a coil spring that is a conventional pressure spring. 1...Elastic body, 2...Piezoelectric body, 3...
... Vibrating body, 4... Support body, 6...
・Friction material, 6...Elastic body, 7...Moving body, 8...Coil spring, 9...R ring, 1o...・Retaining ring, 11.11'...
...Farewell. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Measurement amount Fig. 2 (α) tb) If, /f'---Sara 1; /, 6- Low body 11.11''- to 1 Yone Figure 6 Figure 7 r: 1F) Misato
Claims (3)
とから構成される振動体に弾性進行波を励振することに
より、前記振動体上に加圧接触して設置された移動体を
移動させる構成であって、加圧力許容領域のばね定数が
、前記加圧力許容領域以下のばね定数よりも小さい加圧
用ばねを用いて、前記移動体を前記振動体上に加圧接触
して設置したことを特徴とする超音波モータ。(1) A moving body installed in pressurized contact with the vibrating body by driving the piezoelectric body with an alternating current voltage and exciting an elastic traveling wave in the vibrating body composed of a piezoelectric body and an elastic body. The movable body is brought into pressure contact with the vibrating body using a pressurizing spring whose spring constant in a pressurizing force permissible area is smaller than a spring constant below the pressurizing force permissible area. An ultrasonic motor characterized by having been installed.
特徴とする請求項1に記載の超音波モータ。(2) The ultrasonic motor according to claim 1, characterized in that a bell spring is installed as the pressurizing spring.
数本の切り欠き、またはスリットを設けた円錐形状のさ
らばねを設置したことを特徴とする請求項2に記載の超
音波モータ。(3) The ultrasonic motor according to claim 2, wherein a conical spring having a plurality of notches or slits radially arranged around the inner diameter portion is installed as the pressurizing spring.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP63076701A JPH01252179A (en) | 1988-03-30 | 1988-03-30 | Ultrasonic motor |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP63076701A JPH01252179A (en) | 1988-03-30 | 1988-03-30 | Ultrasonic motor |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH01252179A true JPH01252179A (en) | 1989-10-06 |
Family
ID=13612815
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP63076701A Pending JPH01252179A (en) | 1988-03-30 | 1988-03-30 | Ultrasonic motor |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH01252179A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5463265A (en) * | 1991-05-08 | 1995-10-31 | Canon Kabushiki Kaisha | Vibration driven motor |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS62126877A (en) * | 1985-11-27 | 1987-06-09 | Canon Inc | Vibration wave motor |
-
1988
- 1988-03-30 JP JP63076701A patent/JPH01252179A/en active Pending
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS62126877A (en) * | 1985-11-27 | 1987-06-09 | Canon Inc | Vibration wave motor |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5463265A (en) * | 1991-05-08 | 1995-10-31 | Canon Kabushiki Kaisha | Vibration driven motor |
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