JPS60210176A - Vibration wave motor - Google Patents

Abstract

PURPOSE:To obtain a high output by using the peripheral surface of a vibrator as a contacting surface of a moving element in a motor for driving the element by generating a vibration wave with an elecrostrictive element, and disposing the electrostrictive elements on both sides of the vibrator, thereby generating a large twisting vibration. CONSTITUTION:Polarized ring-shaped electrostrictive elements 12, 12' are respectively bonded to the planar surfaces of both sides of a ring-shaped vibrator 31, a frequency voltage is applied to the elements 12, 12' to allow the vibrator 31 to generate a traveling vibration wave and a twisting vibration. A movable elment 35 energized by a spring 20 is frictionally contacted with the peripheral surface of the inner or outer peripheral surface side of the vibrator 31, and rotatably driven by the traveling vibration wave. Thus, twice twisting vibration is obtained as compared with the case that the electrostrictive element is secured to one side of the vibrator 31, thereby obtaining high output.

Description

【発明の詳細な説明】 本発明は進行性振動波により駆動する回転型の振動波モ
ータの構造に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of a rotary vibration wave motor driven by progressive vibration waves.

振動波モータは、電歪素子に周波電圧を印加したときに
生ずる振動運動を回転運動又は−次元運動に変換するも
ので、従来の電磁モータに比べて巻線を必要としないた
め、構造が簡単で小型になり、低速回転時にも高トルク
が得られるという利点があり、近年注目されている。A vibration wave motor converts the vibration motion generated when a frequency voltage is applied to an electrostrictive element into rotational motion or -dimensional motion, and has a simpler structure than conventional electromagnetic motors because it does not require windings. It has been attracting attention in recent years because it has the advantage of being small in size and being able to obtain high torque even when rotating at low speeds.

第１図、第２図は従来の振動波モータの駆動原理を示す
もので、第１図は上記モータの振動波の発生状態を示し
ている。振動体ｌ（通常は金属）に接着された電歪素子
２ａ、２ｂは、振動体１の片側、適度に離れた所に、空
間的に入／４の位相ずれを満足するように配置されてい
る。1 and 2 show the driving principle of a conventional vibration wave motor, and FIG. 1 shows the state in which vibration waves are generated by the motor. The electrostrictive elements 2a and 2b bonded to the vibrating body 1 (usually metal) are arranged on one side of the vibrating body 1 at a moderate distance from each other so as to spatially satisfy a phase shift of /4. There is.

振動体ｌを電歪素子２ａ、２ｂの一方の電極とし、電歪
素子２ａには、交流電源３ａからＶ＝ＶＯｓｉｎωｔ、
電歪素子２ｂには９０＠移相器３ｂを通して入／４位相
のずれたＶ＝＝Ｖｏｓｉｎ　（ωｔ±π／２）の交流電
圧を印加する前記式中の（＋）　（−）が移動体５を動
かす方向によって移相器３ｂで切換えられる。今、（−
）側に切換えてあり、電歪素子２ｂにはＶ＝Ｖｏｓｉｎ
　（ωを一π／２）の電圧が印加されているとする。電
歪素子２ａだけが単独で電圧Ｖ＝ＶＯｓｉｎωｔにより
振動した場合は、同図（ａ）に示すような定在波による
振動が起り、電歪素子２ｂだけが単独で電圧Ｖ＝Ｖ６　
ｓｉｎ　（ωｔ−ｔｃ／　２）により振動した場合は、
同図（ｂ）に示すような定在波による振動が起る。上記
位相のずれた２つの交流電圧を同時に各々の電歪素子２
ａ、２２ｂに印加すると振動波は進行性になる。（イ）
は時間ｔ＝２ｎ　π　／　ω　、　（口　）　はＥ＝π
／２ω＋２ｎπ／ω、（ハ）は ｔ＝π／ω＋２ｎπ／ω、（ニ）は ｔ＝３π／２ω＋２ｎπ／ωの時のもので、振動波の波
面はＸ方向に進行する。The vibrating body l is used as one electrode of the electrostrictive elements 2a and 2b, and the electrostrictive element 2a is supplied with V=VO sin ωt from the AC power source 3a.
An AC voltage of V==Vosin (ωt±π/2) with a phase shift of 4 is applied to the electrostrictive element 2b through the phase shifter 3b. It is switched by the phase shifter 3b depending on the direction in which the phase shifter 5 is moved. Now, (−
) side, and the electrostrictive element 2b has V=Vosin
Assume that a voltage of (ω = 1/2) is applied. When the electrostrictive element 2a alone vibrates with the voltage V=VOsinωt, vibrations due to standing waves as shown in FIG.
If it oscillates due to sin (ωt-tc/2),
Vibration occurs due to standing waves as shown in FIG. 2(b). The above two phase-shifted AC voltages are simultaneously applied to each electrostrictive element 2.
When applied to a and 22b, the vibration wave becomes progressive. (stomach)
is time t=2n π/ω, (mouth) is E=π
/2ω+2nπ/ω, (c) is when t=π/ω+2nπ/ω, (d) is when t=3π/2ω+2nπ/ω, and the wavefront of the vibration wave advances in the X direction.

このような進行性の振動波は縦波と横波を伴なっており
、第２図に示すように振動体ｌの質点Ａについて着目す
ると、縦振幅Ｕと横振幅Ｗで反時計方向の回転楕円運動
をしている。振動体ｌの表面には移動体５が加圧接触し
ており振動面の頂点にだけ接触することになるから（実
際には、ある幅をもって面接触している）、頂点におけ
る質点Ａ　、　Ａ　′、　−−−−−一の楕円運動の縦
振幅Ｕの成分に駆動され、移動体５は矢印Ｎ方向に移動
する。Such progressive vibration waves are accompanied by longitudinal waves and transverse waves, and if we focus on the mass point A of the vibrating body l as shown in Fig. 2, we can see that it forms an ellipse of revolution in the counterclockwise direction with a longitudinal amplitude U and a transverse amplitude W. I'm exercising. Since the movable body 5 is in pressurized contact with the surface of the vibrating body 1 and is in contact only with the apex of the vibrating surface (actually, it is in surface contact with a certain width), the mass points A and A at the apex are ', ----- Driven by the component of the longitudinal amplitude U of the one elliptical motion, the moving body 5 moves in the direction of the arrow N.

９０°移相器により＋９０″位相をずらせば振動波は−
Ｘ方向に進行し、移動体５はＮ方向と逆向きに移動する
。If the phase is shifted by +90″ using a 90° phase shifter, the vibration wave becomes -
Moving in the X direction, the moving body 5 moves in the opposite direction to the N direction.

この振動波モータを使って回転運動を起こさせるような
回転型振動波モータの構造を第３図に示す。第４図はそ
の断面図である。第３図において１１は主に金属よりな
る弾性を有する振動体、１２は振動体１１に接合される
電歪素子、１５は振動体１１に加圧接触する移動体、１
６は回転円板（回転軸）、１７は振動体１１を支持する
吸振体、１８は固定体である。FIG. 3 shows the structure of a rotary vibration wave motor that uses this vibration wave motor to generate rotational motion. FIG. 4 is a sectional view thereof. In FIG. 3, 11 is an elastic vibrating body mainly made of metal, 12 is an electrostrictive element joined to the vibrating body 11, 15 is a movable body that presses into contact with the vibrating body 11, and 1
6 is a rotating disk (rotating shaft), 17 is a vibration absorber that supports the vibrating body 11, and 18 is a fixed body.

電歪素子２と同様の構造よりなる電歪素子１２に外部電
源より周波電圧を印加し、振動体１１か共振するような
駆動周波数とする。バネ２ｏによりスラスト軸受９を介
して振動体１１に加圧接触する移動体１５には摩擦力が
作用し、移動体１５に接合されている回転軸１６は回転
する。固定カバー２１はビス２２により固定体１８に固
定され、電歪素子１２と固定体１８の間に吸振体１７を
挿入する事で振動体１１の超音波振動を固定体１８に伝
えないような構造となっている。A frequency voltage is applied from an external power source to an electrostrictive element 12 having the same structure as the electrostrictive element 2, and a driving frequency is set such that the vibrating body 11 resonates. Frictional force acts on the movable body 15 which is pressed into contact with the vibrating body 11 via the thrust bearing 9 by the spring 2o, and the rotating shaft 16 joined to the movable body 15 rotates. The fixed cover 21 is fixed to the fixed body 18 with screws 22, and has a structure in which the ultrasonic vibration of the vibrating body 11 is not transmitted to the fixed body 18 by inserting a vibration absorber 17 between the electrostrictive element 12 and the fixed body 18. It becomes.

しかしながら、この振動波モータを回転させた際には振
動体１１がリング状をなしているため、第２図に示す様
なモードの振動をするだけではなく、振動体１１がリン
グ面に垂直な方向に曲げ振動を生じるとともにリング面
の円周方向のまわりに第５図に示すようなねじりが発生
し、リング面に垂直な曲げ振動とリング面の円周方向の
まわりのねじりがともに発生する。ここで振動波モータ
においてはリング面に垂直な方向に生じる曲げ振動によ
る進行波を利用して移動体１５を駆動°していたためリ
ング面の円周方向のまわりに発生する振動のねじり成分
による進行波を有効に利用していなかったため、円周方
向のまわりに発生する振動のねじり成分のエネルギーが
損失することになった。However, when this vibration wave motor is rotated, since the vibrating body 11 has a ring shape, it not only vibrates in the mode shown in Fig. 2, but also vibrates in a direction perpendicular to the ring surface. Bending vibration occurs in the direction, and twisting occurs around the circumferential direction of the ring surface as shown in Figure 5, and both bending vibration perpendicular to the ring surface and twisting around the circumferential direction of the ring surface occur. . Here, in the vibration wave motor, since the movable body 15 is driven using the traveling wave caused by the bending vibration generated in the direction perpendicular to the ring surface, the movement is caused by the torsional component of the vibration generated around the circumferential direction of the ring surface. Because the waves were not used effectively, the energy of the torsional component of vibration generated around the circumference was lost.

したがって振動波モータの効率が低下するという欠点が
あった。Therefore, there is a drawback that the efficiency of the vibration wave motor is reduced.

更には振動体１１のリング面の円周方向のまわりの振動
のねじり成分の振幅は第５図に示すようにリング面の内
径側から外径側にうつるにつれて大きくなるため振動体
１１の表面上に発生する質点の楕円運動は内径側から外
径側に行くに従って大きくなる。その結果移動体１５か
おもにリング面の外径側の部分に接触し、振動体１１の
リング面の内径側の部分には接触しなくなる。Furthermore, since the amplitude of the torsional component of the vibration around the circumferential direction of the ring surface of the vibrating body 11 increases from the inner diameter side to the outer diameter side of the ring surface as shown in FIG. The elliptical motion of the mass point that occurs in the curve increases from the inner diameter side to the outer diameter side. As a result, the movable body 15 mainly contacts the outer diameter side portion of the ring surface, and does not contact the inner diameter side portion of the ring surface of the vibrating body 11.

すなわち移動体１５と振動体１１の接触面積は実質的に
小さくなり振動体１の進行波が移動体１５に伝わる効率
が低下して充分な出力が得られなくなるという欠点があ
った。That is, the contact area between the movable body 15 and the vibrating body 11 becomes substantially small, and the efficiency with which the traveling waves of the vibrating body 1 are transmitted to the movable body 15 decreases, resulting in a disadvantage that sufficient output cannot be obtained.

本発明は上述の従来の振動波モータの振動のねじり成分
による振動の損失を有効に利用することができ、振動体
と移動体の実質上の接触面積を大きくし、かつ電歪素子
の面積も大きくすることにより高出力・高効率を得るこ
とかできる振動波モータを提供することを目的とするも
のである。The present invention can effectively utilize the vibration loss due to the torsional component of the vibration of the conventional vibration wave motor described above, increase the substantial contact area between the vibrating body and the moving body, and reduce the area of the electrostrictive element. The object of the present invention is to provide a vibration wave motor that can obtain high output and high efficiency by increasing its size.

ここで本発明は振動波モータにおける電歪素子の配置を
特徴とするものである。Here, the present invention is characterized by the arrangement of the electrostrictive element in the vibration wave motor.

第６図は本発明の第１の実施例の振動波モータの断面図
である。第６図において３１は振動体、３５は移動体、
３６は回転円板（回転軸）で、その他の第４図と同様な
構成となっている部分については同じ符号を付し説明を
省略する。FIG. 6 is a sectional view of a vibration wave motor according to a first embodiment of the present invention. In FIG. 6, 31 is a vibrating body, 35 is a moving body,
Reference numeral 36 denotes a rotating disk (rotating shaft), and other parts having the same configuration as in FIG. 4 are designated by the same reference numerals and explanations thereof will be omitted.

第７図（ａ）、（ｂ）は、本発明の駆動原理を説明する
説明図で、（ａ）に示す様に、振動体１１と電歪素子１
２　、１２″は点線に示す様な断面の運動を行う。その
際、（ｂ）に示す様に、移動体３５を振動体３１の内径
面にあてると、振動体１１の振動の捩り成分を駆動に用
いる事ができる。本実施例では、振動体１１と移動体３
１の接触面はリンク面に垂直ではなく、ある傾きをもた
せ自動調心作用を有するような構造としている。FIGS. 7(a) and 7(b) are explanatory views for explaining the driving principle of the present invention. As shown in FIG. 7(a), the vibrating body 11 and the electrostrictive element 1
2 and 12'' move in a cross section as shown by the dotted line. At that time, as shown in (b), when the moving body 35 is applied to the inner diameter surface of the vibrating body 31, the torsional component of the vibration of the vibrating body 11 is It can be used for driving.In this embodiment, the vibrating body 11 and the moving body 3
The contact surface of No. 1 is not perpendicular to the link surface, but has a certain inclination so as to have a self-aligning effect.

第８図は電歪素子１２．１２／の配置を示す平面図で、
（ａ）は従来から用いてきた電歪素子で、０６位相極を
１２ａが、±９０°位相極を１２ｂが示していて、それ
ぞれ入／４離れている。これは、複数個の電歪素子でも
、電歪素子を複数に位相差的に分極処理したものでも良
い。これを振動体３１の両面に接合する。但し、電歪素
子１２と１２″は回転軸方向から見て、同じ位置に、同
じ電歪素子か対応する様に接合しなければならない。FIG. 8 is a plan view showing the arrangement of electrostrictive elements 12.12/,
(a) is an electrostrictive element that has been used conventionally, and 12a indicates the 06 phase pole, and 12b indicates the ±90° phase pole, which are spaced apart by 1/4. This may be a plurality of electrostrictive elements or a plurality of electrostrictive elements polarized in a phase difference manner. This is bonded to both sides of the vibrating body 31. However, the electrostrictive elements 12 and 12'' must be joined at the same position and in correspondence with each other when viewed from the direction of the rotation axis.

本実施例中、振動体３１の内径面に移動体３５との接触
面を持って来たが、振動体３１の外径面を移動体３５と
の接触面としても良い。また、電歪素子の配置は、第８
図（ａ）に示す従来から知られているパターンに限らず
、例えば、第８図（ｂ）に示す様に、内側と外側の２列
の電歪素子を入／４位相をずらせて配置したものでも良
い。In this embodiment, the contact surface with the movable body 35 is provided on the inner diameter surface of the vibrating body 31, but the contact surface with the movable body 35 may be made on the outer diameter surface of the vibrator 31. Furthermore, the arrangement of the electrostrictive element is
In addition to the conventionally known pattern shown in Figure 8(a), for example, as shown in Figure 8(b), two rows of electrostrictive elements, inner and outer, are arranged with an input/4 phase shift. Anything is fine.

但し、対応する電歪素子が回転軸方向から見て、同じ位
置に来る様、電歪素子１２と１２′を接合するのは同じ
である。この場合、電歪素子の全面積は（ａ）より大き
くとれるので加振力は大きくなる。However, the electrostrictive elements 12 and 12' are joined in the same manner so that the corresponding electrostrictive elements are located at the same position when viewed from the direction of the rotation axis. In this case, the total area of the electrostrictive element can be larger than that shown in (a), so the excitation force becomes larger.

以上、説明した様に、本発明に依れば振動体の内径又は
外径面を、移動体との接触面とし、電歪素子を２枚（２
群）振動体を挟んで接合する事で、２倍の大きな振動体
の捩り振幅を駆動に利用し、更に振動体の厚さに応じて
移動体との接触面積を拡大できるので、高出力が得られ
、ひいては効率アップとなる。また、本実施例に依れば
前記接触面がリング面に対して傾いているので、自動調
心性を有し、回転ムラの少ない安定した出力が得られる
。As explained above, according to the present invention, the inner diameter or outer diameter surface of the vibrating body is used as the contact surface with the moving body, and two electrostrictive elements (2
Group) By joining the vibrating body between them, the torsional amplitude of the vibrating body, which is twice as large, can be used for driving, and the contact area with the moving body can be expanded according to the thickness of the vibrating body, resulting in high output. This results in increased efficiency. Further, according to this embodiment, since the contact surface is inclined with respect to the ring surface, it has self-aligning property and stable output with little rotational unevenness can be obtained.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図、第２図は振動波モータの駆動原理説明図、第３
図、第４図はそれぞれ従来例の斜視図及び断面図、第５
図は従来例の説明図、第６図は本発明実施例の断面図、
第７図は本発明実施例の説明図、第８図は電歪素子の配
置を示す平面図゛である。 １．１１．３１は振動体、５，１５．３５は移動体、２
　、１２　、１２’は電歪素子、１７は吸振体である。 出願人　キャノン株式会社 （ 第７図 （０） （ｂ） １４　ｉFigures 1 and 2 are explanatory diagrams of the driving principle of the vibration wave motor, and Figure 3 is
Figure 4 is a perspective view and sectional view of the conventional example, and Figure 5 is a perspective view and a sectional view of the conventional example, respectively.
The figure is an explanatory diagram of a conventional example, and FIG. 6 is a sectional view of an embodiment of the present invention.
FIG. 7 is an explanatory diagram of an embodiment of the present invention, and FIG. 8 is a plan view showing the arrangement of electrostrictive elements. 1.11.31 is a vibrating body, 5, 15.35 is a moving body, 2
, 12, 12' are electrostrictive elements, and 17 is a vibration absorber. Applicant Canon Co., Ltd. (Figure 7 (0) (b) 14 i

Claims (1)

【特許請求の範囲】[Claims] （１）リング状振動体の平面部に複数の電歪素子の位相
差的に接合し、又は複数に位相差的に分極処理された電
歪素子を接合し、該電歪素子に周波電圧を印加して該振
動体に進行性振動波を発生させ、その進行性振動波によ
り、前記振動体に加圧接触させた移動体を摩擦駆動する
モータにおいて、 前記振動体の内径面又は外径面を、前記移動体との接触
面とし、該電歪素子で前記振動体を挟む様に、接合して
成るモータ。(1) A plurality of electrostrictive elements are joined to the plane part of the ring-shaped vibrating body in a phase difference manner, or a plurality of electrostrictive elements polarized in a phase difference manner are joined, and a frequency voltage is applied to the electrostrictive element. A motor that generates a progressive vibration wave in the vibrating body by applying an electric current to the vibrating body, and uses the progressive vibration wave to frictionally drive a movable body that is brought into pressurized contact with the vibrating body. is a contact surface with the moving body, and the electrostrictive element is joined to sandwich the vibrating body.