1345871 九、發明說明： 【發明所屬之技術領域】 本發明係有關於振動致動器，特別是有關於利用超音 波振動而使轉動體轉動的振動致動器。 【先前技術】 例如，在專利文獻1中，如第18圖所示，揭示一種利 用超音波振動而使球體狀的轉子101轉動之振動致動器。 將線材102之一端部固定於轉子101的內部，藉由牽引該 線材102使轉子101對定子103加壓接觸，並利用壓電元 件104使定子103產生超音波振動以使轉子101轉動。藉 由用以使轉子101對定子103加壓之線材102穿過定子103 及壓電元件104的內部，而可圖謀該振動致動器整體小型 化。 以此振動致動器而言，係在轉子101之內部形成通過 其轉動中心的穿通孔105,而且線材102之一端部插入此穿 通孔105,並經由軸承106固定於穿通孔105的內壁面，藉 此防止轉子101之轉動所伴隨的線材102之扭轉等的發 生。又，爲了避免線材102妨礙到轉子101之轉動，穿通 孔105係形成爲從轉子101的轉動中心朝向與定子103相 對向之轉子101的表面具有圓錐形。 專利文獻1 :特開2 0 0 6 — 5 9 7 5號公報 【發明內容】 【發明所欲解決之課題】 可是，如同專利文獻1之振動致動器，要在球體狀之 1345871 轉子101的內部，形成通過其轉動中心且從轉動中心朝向 與定子103相對向之轉子101的表面具有圓錐形之穿通孔 105並不容易，而具有費人力且費用昂貴的問題。 又，因爲在穿通孔105的內部需要設置用以固定線材 102之一端部的軸承機構1〇6，所以構造複雜且製作困難。 本發明係爲解決這種問題點而開發者，其目的在於提 供一種雖小型但可容易以簡單構成製作之致動器。 【解決課題之手段】 本發明之振動致動器，係具備有：定子；複數個滾輪， 係分別由定子接觸支持，並共用一支轉軸；連結銷，係將 複數個滾輪之間連結；振動手段，係和定子連結，而且藉 由使定子振動，而使定子和複數個滾輪之接觸部分產生橢 圓或圓運動而使複數個滾輪轉動；以及預壓手段，係其一 端部在複數個滾輪之中間部和連結銷連結，並藉由將連結 銷朝定子牽引，而使複數個滾輪對定子加壓。 此外，「複數個滾輪之中間部」意指複數個滾輪之中位 於最外側的2個滾輪之間。 【發明之效果】 若依據本發明，可實現一種雖小型但能容易以簡單構 成製作的振動致動器。 【實施方式】 以下，根據附加圖面說明本發明之實施形態。 第1實施形態 第1圖表示本發明之第1實施形態的振動致動器。此 1345871 振動致動器係利用超音波振動使轉動體轉動之超音波致動 器，例如係構成在可自走之機器人的手當中的一根手指 者。振動手段3配置於基部支持構件1和定子2之間，而 且在定子2之與振動手段3接觸的面之相反側形成有槽4, 在該槽4的表面係接觸並支撐有作爲手指之關節的2支圓 柱形滾輪5。這2支滾輪5具有相同之大小並彼此平行地配 置，而且各自配置成繞共同的一支轉軸自由轉動。連結銷 6穿通各連結銷6的中心，並利用該連結銷6連結2個滾輪 5之間，此連結銷6在雙方的滾輪5構成共同之一支轉軸。 這些滾輪5具有前端構件7,其固定於雙方之滾輪5的外周 部，並和滾輪5 —體地轉動。又，在振動手段3，連接用 以驅動該振動手段3之驅動電路8。 如第2圖所示，定子2在其中心形成貫穿孔9，而整體 具有大致圓筒形狀。又，在要接觸配置滾輪5之定子2的 表面所形成的槽4，係通過定子2之中心且具有V字形的 截面形狀。 如第3圖所示，基部支持構件1具有：圓筒形之本體 部10’其內部形成有凹部；及圓筒形之插入部U,其形成 有比本體部10直徑還小且和本體部1〇的凹部連通之貫穿 孔。藉由插入部11通過圓筒形之振動手段3內，並以其前 端和定子2之貫穿孔9的內壁面連結，而將振動手段3夾 持於基部支持構件1的本體部！〇和定子2之間，這些定子 2、振動手段3以及基部支持構件1整體上具有大致圓柱形 的外形。 1345871 在此，爲了便於說明，將從基部支持構件1往定子2 之圓柱形的外形之中心軸規定爲Z軸，而X軸朝向對Z軸 垂直的方向延伸，Y軸朝向對Z軸及X軸垂直的方向延伸。 振動手段3係各自位於χγ平面上且彼此重疊之平板 形之第1壓電元件部31及第2壓電元件部32。 在定子2、振動手段3、基部支持構件1之插入部11 以及本體部10的內部，朝向其中心軸方向，即Z軸方向將 桿12穿通。桿12的一端部位於2個滾輪5之間，並在此 桿12之一端部形成大致矩形的板狀部13。藉由連結銷6 貫穿形成於板狀部13之貫穿孔，而使桿12之一端部和連 結銷6連結。在此，連結銷6朝向X軸方向延伸，而且板 狀部13在連結銷6之延伸方向，即X軸方向位於2個滾輪 5的中央部，2個滾輪5配置成對板狀部13相對稱。此外， 建構成藉由連結銷6和各滾輪5之間、及連結銷6和桿12 的板狀部13之間當中的至少一方連結成自由轉動，而使滾 輪5可對桿12轉動。 前端構件7具有突出形成在2個滾輪5間的一對突起 部14及15,這些突起部14及15沿著滾輪5之圓周方向彼 此取間隔作配置。在板狀部1 3，藉由位於面對定子2之面 的相反側之面及位於一方之側部的面各自與突起部14及 15抵接，而構成用以將滾輪5之轉動限制於既定的角度範 圍之抵接面16及17。 這些抵接面16及17和突起部14及15各自構成本發 明之第1限制部和第2限制部 134.5871 此外’板狀部13的抵接面16及17，爲了避免妨礙滾 輪5轉動所伴隨的突起部14及15之移動，而透過倒角成 圓弧形的倒角部相互連接。 桿12之另一端部被固定於彈簧座構件18,其位於基部 支持構件1之本體部10的凹部內，且被收容成可在該凹部 內自由滑動。在本體部1〇之凹部的底面20和彈簧座構件 1 8之間’配置作爲本發明之牽引裝置的彈簧1 9，彈簧！ 9 將彈簧座構件18朝向和本體部1〇之凹部的底面20反方向 彈推。利用此彈簧19之彈推力，而透過彈簧座構件18及 桿12，朝向定子2牽引連結銷6，因而使滾輪5對定子2 加壓接觸。 如第4圖所示’第1壓電元件部31及第2壓電元件部 32經由絕緣片33〜35，以與定子2及基部支持構件1，且 彼此絕緣之狀態配置。第1壓電元件部31具有各自是圓板 形之電極板31a、壓電元件板31b、電極板31c、壓電元件 板31d以及電極板31e依序重疊之構造》同樣地，第2壓 電元件部32具有各自是圓板形之電極板32a、壓電元件板 3 2b、電極板32c、壓電元件板32d以及電極板32e依序重 疊之構造。 配置於第1壓電元件部31之雙面部分的電極板31a及 電極板31e、配置於第2壓電元件部32之雙面部分的電極 板3 2a及電極板32e各自電氣接地。又，從配置於第1壓 電元件部31的一對壓電元件板31b及31d之間的電極板 31c、和配置於第2壓電元件部32的一對壓電元件板32b 1345871 及32d之間的電極板32c各自拉出端子， 連接。 此外，驅動電路8具有檢測手段，其 段3之電壓而監視作用於此振動手段3的 該應力之變化而檢測滾輪5分別到達既定 端部。 如第5圖所示，第1壓電元件部31的 31b及31d之朝向Y軸方向所二分割之部 性，並極化成各自朝向Z軸方向（厚度方 縮之相反的變形舉動，壓電元件板31b和 配置成彼此表裡相反。 第2壓電元件部32的一對壓電元件板 二分割，並極化成整體朝向Z軸方向（厚ί 和收縮之變形舉動，壓電元件板32b和壓 置成彼此表裡相反。 其次，說明本第1實施形態之振動致 用驅動電路8對第1壓電元件部31之電極 電元件部32的電極板32c各自施加使相β 流電壓，並在利用振動手段3產生由Υ軸 和Ζ軸方向的縱向振動所組合之複合振動 和定子2的接觸部分產生在ΥΖ面內的橢Β 2個滾輪5各自以連結銷6爲中心繞X軸 這2個滾輪5同時且朝向同一方向轉動， 著該轉動而對定子2進行傾斜動作。 並和驅動電路8 藉由量測振動手 應力，而且根據 之角度範圍的兩 一對壓電元件板 分彼此具有反極 句）進行膨脹和收 壓電元件板3 1 d 32b及32d未被 寅方向）進行膨脹 電元件板32d配 動器的動作。利 板31c和第2壓 Ϊ偏移90度之交 方向之彎曲振動 時，在各滾輪5 S運動，因而，將 進行轉動驅動。 前端構件7係隨 -10- 1345871 在此，如第6圖所示，藉由前端構件7之一方的突起 部14和與其對應之板狀部13的抵接面16抵接，而限制滾 輪5朝第6圖中順時針方向進一步轉動。又，如第7圖所 示，藉由前端構件7之另一方的突起部15和與其對應之板 狀部13的抵接面17抵接，而限制滾輪5朝第7圖反時針 方向進一步轉動。如此可將滾輪5的轉動限制於既定之角 度範圍。此時，將滾輪5的轉動限制於約90°之角度範圍。 又，因爲振動手段3被夾持於基部支持構件1和定子 2之間，而且將滚輪5對定子2加壓接觸，所以藉由前端構 件7的一對突起部14及15各自和與其對應之桿12的板狀 部13之抵接面16及17抵接，經由連結銷6、滾輪5以及 定子2而作用於振動手段3之應力就發生變化。在此，驅 動電路8因爲藉由量測振動手段3之電壓而監視作用於振 動手段3的應力，所以藉由檢測在前端構件7的一對突起 部14及15各自和對應之抵接面16及17抵接時所產生的 振動手段3之應力變化，而可檢測滾輪5到達既定之角度 範圍的各自之端部。 因此，不必新設置用以檢測滾輪5到達可動極限的極 限感測器等。 在此振動致動器，因爲用連結銷6將圓柱形之2.個滾 輪5之間連結，而且將桿12的一端部和該連結銷6連結並 牽引，而將滾輪5對定子2進行加壓，所以可實現構造簡 單而且可易於製作的振動致動器。 因爲桿12以2個滾輪5之中央部牽引連結銷6，所以 134*5871 可將各個滾輪5對定子2以均勻的力進行加壓。又，藉由 將彈推力大小相異的彈簧配置於本體部10之凹部的底面 20和彈簧座構件18之間，而可易於調整要將2個滾輪5 各自對定子2進行加壓之力的大小。 又，因爲桿12穿過定子2、振動手段3以及基部支持 構件1之內部，而且彈簧座構件18及彈簧19被收容於基 部支持構件1的凹部內，所以達成此振動致動器整體的小 型化》 又，因爲2個滾輪5各自接觸配置於定子2所形成的 截面V字形之槽4的表面，所以利用定子2可穩定地支持 這2個滾輪5。 又，因爲藉由以振動手段3使定子2振動，而2個滾 輪5僅繞共同之一個轉軸轉動，所以可進行穩定的動作， 而且可高精度地控制滾輪5之轉動。因此，藉由使用複數 個該振動致動器，而可實現進行和人手近似之機械手臂。 第2實施形態 其次，參照第8圖，說明本發明之第2實施形態的振 動致動器。本第2實施形態係在第1實施形態的振動致動 器中，於2個滾輪5之兩側，又將2個滾輪5設置成對板 狀部13彼此對稱。即，彼此具有相同之大小及形狀的4個 滾輪5，經由連結銷6連結，而且藉由桿12之板狀部13 和連結銷6連結並被牽引，而使滾輪5對定子2加壓接觸。 桿12之板狀部13在滾輪5的延伸方向位於4個滾輪5之 中央部。此外，在此，省略位於中間部之2個滾輪5的外 -12- 1345871 周部所固定之前端構件7的圖示。 因爲以連結銷6連結圓柱形的4個滾輪5之間，並利 用穿過定子2'振動手段3以及基部支持構件1之內部的桿 12牽引連結銷6，而使滾輪5對定子2加壓接觸，所以和 上述之第1實施形態一樣可實現雖小型但容易以簡單的構 造製作之振動致動器。 此外’在本第2實施形態，因爲使4個滾輪5各自對 定子2加壓接觸，而且利用定子2之振動將這4個滾輪5 進行轉動驅動，並使前端構件7進行傾斜動作，所以實現 高扭矩’而且減少各滾輪5及定子2之接觸部分的磨耗。 又，因爲4個滾輪5不僅配置成對桿12之板狀部13 彼此對稱，而且具有彼此相同的大小及形狀，所以可進行 穩定之轉動。 此外，亦可於4個滾輪5之兩側，又將偶數個滾輪5 設置成對板狀部13彼此對稱。 第3實施形態 其次，參照第9圖’說明本發明之第3實施形態的振 動致動器。本第3實施形態係取代在上述之第2實施形態 中將具有相同之大小的2個滾輪5設置於位於中間部之2 個滾輪5的兩側，而改為將各自具有比滾輪5更小之直徑 的2個滾輪41設置成對板狀部13彼此對稱。在和定子2 之振動手段3接觸的面之相反側的面’沿著連結銷6的延 伸方向形成具有和4個滾輪5及41對應之段差狀的截面形 狀之接觸部42。藉由以桿12牽引連結銷6’而使各滾輪5 1345871 及滾輪41對定子2加壓接觸。 即便是如此構成，亦可得到和上述之第2實施形態一 樣的效果。 此外，在本第3實施形態中，因爲將各自具有比滾輪 5更小之直徑的2個滾輪41配置於2個滾輪5之兩側，所 以可使振動致動器變成更小型。 此外，反之，亦可將具有小直徑的2個滾輪41配置於 中間部，並各自將滾輪5配置於其兩側。 又，亦可在4個滾輪5及41之兩側，又將偶數個滾輪 設置成對板狀部13彼此對稱。此時，新追加之滾輪亦可係 具有和滾輪5及41相同的直徑者，亦可係具有大小和滾輪 5及41相異之直徑者。在任一種情況，都在和定子2之振 動手段3接觸的面之相反側的面，沿著連結銷6的延伸方 向形成具有和這些滾輪對應之截面形狀的接觸部，並使各 滾輪對定子2加壓接觸較佳。 又，雖然在上述之第1〜第3實施形態說明設置偶數 個滾輪的情況，但是未限定如此，亦可設置3個以上之奇 數個滾輪。例如，如第10圖所示，可利用連結銷6將3個 滾輪5相連結並使用。在此情況，在定子2沿著其軸向形 成2個貫穿孔9，而且將分支成2支之桿12的一端部各自 插入貫穿孔9，再以板狀部1 3和連結銷6連結，藉此以桿 12牽引連結銷6，而可使3個滾輪5對定子2加壓接觸。 第4實施形態 在上述之第1實施形態中，亦可取代圓柱形之2個滾 -14- 1345871 輪5，而如第11圖所示，改為使用具有截圓錐形的2個滾 輪51。2個滾輪51之大徑部52配置成彼此相對向。在和 定子2之振動手段3接觸的面之相反側的面，沿著連結銷 6的延伸方向形成具有和2個滾輪51對應之截面形狀的接 觸部53,並使各滾輪51對定子2加壓接觸。此外，未圖示 之前端構件固定於2個滾輪51的外周部。 即便是如此構成，亦可得到和第1實施形態一樣的效 果。 此外，如第12圖所示，亦可2個滾輪51之大徑部52 配置成彼此朝向相反方向。 又，在第11圖及第12圖中之與定子2抵接之各滾輪 51的外周面，亦可形成爲朝向其中心軸呈彎曲狀的缺口， 或朝向該中心軸的相反方向彎曲狀地鼓起。 又，作爲在上述之第2及第3實施形態的各滾輪，亦 可使用此截圓錐形的滾輪51。 第5實施形態 在上述之第1實施形態中，亦可取代圓柱形之2個滾 輪5，而如第13圖所示，改為使用具有半球形的2個滾輪 61。2個滾輪61之平面部62配置成彼此相對向。在和定子 2之振動手段3接觸的面之相反側的面，沿著連結銷6的延 伸方向形成具有和2個滾輪61對應之截面形狀的接觸部 63，並使各滾輪61對定子2加壓接觸。此外，未圖示之前 端構件固定於2個滾輪61的外周部》 即便是如此構成，亦可得到和第1實施形態一樣的效 -15- 1345871 果。 此外，如第14圖所示，亦可2個滾輪61之平面部62 配置成彼此朝向相反方向。 又，作爲在上述之第2及第3實施形態的各滾輪，亦 可使用此半球形的滾輪61。 第6實施形態 雖然在上述之第1〜第5實施形態，矩形的板狀部13 設置於桿12之一端部，但是亦可藉由使該板狀部π之一 對抵接面1 6及1 7的部分呈缺口，而例如如第1 5圖所示， 形成斜的抵接面71及72。在此情況，藉由設置於前端構件 之一對突起部各自和對應的抵接面71及72抵接，滾輪之 轉動係被限制於比90°更大的既定之角度範圍。 即’藉由選擇突起部之突出高度及抵接面的角度，而 可變更限制滾輪之轉動的角度範圍。 此外’突起部亦可取代設置於前端構件，而改爲設置 於和板狀部13相鄰的滾輪。又，亦可將突起部設置於板狀 部13’並將抵接面設置於前端構件或滾輪。 又’未限定爲突起部和抵接面的組合，可設置各種第 1限制部及第2限制部，其藉由彼此卡合而可限制滾輪的 轉動。例如’亦可將突起部和突起部或抵接面和抵接面之 組合作爲第1限制部及第2限制部來利用。 第7實施形態 其次’參照第16圖’說明本發明之第7實施形態的振 動致動器。本第7實施形態，係在第1實施形態之振動致 -16- 1345871 動器，取代桿12，而將線材81和連結銷6連結並牽引。線 材81係在定子2、振動手段3以及基部支持構件1的內部 對其等之中心軸方向，即Z軸方向插入。此線材81之一端 部係在連結銷6之延伸方向，即X軸方向位於2個滾輪5 的中央部，並和連結銷6連結。 線材81之另一端部固定於基部支持構件1之本體部1〇 的凹部內之彈簧座構件18,利用彈簧19之彈推力，而經由 彈簧座構件18及線材81，朝向定子2牽引連結銷6，因而 使滾輪5對定子2加壓接觸。此外，在2個滾輪5之外周 部，固定具有大致平坦之底面的前端構件82。 因爲以連結銷6連結圓柱形的2個滾輪5之間，並利 用穿過定子2、振動手段3以及基部支持構件1之內部的線 材81牽引連結銷6，而使滾輪5對定子2加壓接觸，所以 和上述之第1實施形態一樣可實現一種雖小型但易於以簡 單之構造製作之振動致動器。 因爲線材81以2個滾輪5的中央部牽引連結銷6，所 以可使2個滾輪5對定子2以均勻之力進行加壓接觸。 又，藉由將彈推力之大小相異的彈簧配置於本體部10 之凹部的底面2 0和彈簧座構件1 8之間，或者調整從連結 銷6至彈簧座構件18爲止之線材81的長度，而可易於調 整2個滾輪5對定子2的加壓力之大小。 此外，在第2〜第5實施形態中，亦可藉由取代桿1 2， 而改爲將線材81和連結銷6連結並牽引，使滾輪對定子2 加壓。 -17- 1345871 此外，雖然在上述之第1〜第7實施形態的桿12及線 材81各自利用彈簧19之彈推力牽引，但是亦可取代彈簧 19,而改爲將使用氣壓或油壓之牽引裝置和桿12及線材81 的另一端部連接，並牽引桿12及線材81。 在該使用氣壓或油壓的牽引裝置，可易於控制牽引桿 12及線材81之力的大小’因此，可易於調整2個滾輪5 對定子2的加壓力之大小。 例如’在未驅動振動手段3時，若以對桿12及線材81 之牽引力變成比振動手段3之驅動時還大的方式控制牽引 裝置，可使靜止時的滾輪5和定子2之間的保持扭矩增大。 第8實施形態 其次，參照第17圖，說明本發明之第8實施形態的振 動致動器。本第8實施形態，係在第1實施形態之振動致 動器中，取代桿12,而改為利用由具有彈性之線狀的橡膠、 樹脂、彈簧等所構成之線材91牽引連結銷6的。線材91 穿通定子2、振動手段3以及基部支持構件1的內部，而線 材91之一端部位於2個滾輪5的中央部，並和連結銷6連 結。 又，固定構件92固定於基部支持構件1之本體部10 的凹部內，而線材91之另一端部固定於該固定構件92»線 材91係在伸長至產生既定之張力的狀態安裝，並利用該線 材91之張力向定子2牽引連結銷6，而使滾輪5對定子2 加壓接觸。 如此構成，亦和第1實施形態一樣可實現一種振動致 -18- 1345871 動器，其雖然是小型，亦是簡單之構造並可易於製作，而 且可使各個滾輪5對定子2以均勻之力進行加壓接觸。 又，藉由調整線材91的伸長程度，以變更線材91之 張力的大小’而可易於調整對定子2之2個滾輪5的加壓 力之大小。 此外，在上述之第2〜第5實施形態，亦藉由替代桿 12’將線材91和連結銷6連結並牽引，而可使滾輪對定子 2加壓。 此外，在上述之第1〜第8實施形態，藉由省略前端 構件，而可使滾輪轉動1圈以上。 又，雖然桿12及線材81、91的另一端部位於基部支 持構件1之本體部10的凹部內，但是亦可位於定子2之貫 穿孔9內。 此外，在上述各實施形態，驅動電路8不是量測振動 手段3之電壓，而藉由量測振動手段3的電流、振動頻率 或相位等，而可監視作用於振動手段3的應力。在此情況， 若以將滾輪的轉動限制於既定之角度範圍的方式構成，驅 動電路8可根據振動手段3之應力的變化，而檢測滾輪到 達既定之角度範圍的端部。 又，監視作用於振動手段3的應力且因應於該應力的 變化而檢測滾輪到達既定之角度範圍的端部之檢測手段， 亦可未內建於驅動電路8'而和驅動電路8分開地設置。 此外，雖然使從驅動電路8對各壓電元件部所施加之 交流電壓的相位偏移90度，但是亦可改變，而未限定爲90 -19- 1345871 度。又，亦可改變所施加之交流電壓的電壓値。藉由各式 各樣地控制交流電壓，而可控制在定子2所產生之橢圓振 動。 此外，亦可產生由彼此未正交之複數種振動所組合的 複合振動，並使複數個滾輪繞共同之一支轉軸轉動。 又，亦可不是將分別以不同之壓電元件部所產生的2 種振動合成而產生複合振動，而是將一個壓電元件部極化 成複數個，並個別地控制施加於各極化電極的電壓。即， 亦可對各極化電極施加將相位、振幅等相異之交流電壓合 成的電流，並以單一之壓電元件部產生複合振動。 又，雖然在上述各實施形態，使定子2和滾輪的接觸 部分產生橢圓運動，但是亦可藉由控制各軸向的振幅而產 生圓運動。 又，此振動致動器不僅可應用於機械手臂之手指，例 如可自走之機械人的腳般可應用在具有關節之各部分。 即，可將此振動致動器之滾輪用作關節。 【圖式簡單說明】 第1圖係表示本發明之第1實施形態的振動致動器之 立體圖。 第2圖係表示在第1實施形態之定子的立體圖。 第3圖係表示第1實施形態之振動致動器的剖面圖。 第4圖係表示在第1實施形態所使用之振動手段的構 造之部分剖面圖。 第5圖係表示在第1實施形態所使用之壓電元件手段 -20 - 1345871 的二對壓電元件板之極化方向的立體圖。 第6圖係表示第1實施形態之振動致動器的動作狀態 之剖面圖。 第7圖係表示第1實施形態之振動致動器的動作狀態 之剖面圖。 第8圖係表示在第2實施形態之滾輪附近的構造圖。 第9圖係表示在第3實施形態之滾輪附近的構造圖。 第10圖係表示在第1實施形態的變形例之滾輪附近的 構造圖。 第11圖係表示在第4實施形態之滾輪附近的構造圖。 第12圖係表示在第4實施形態的變形例之滾輪附近的 構造圖。 第1 3圖係表示在第5實施形態之滾輪附近的構造圖。 第1 4圖係表示在第5實施形態的變形例之滾輪附近的 構造圖。 第15圖係表示在第6實施形態之桿的板狀部之圖。 第1 6圖係表示第7實施形態之振動致動器的剖面圖。 第1 7圖係表示第8實施形態之振動致動器的剖面圖。 第18圖係表示以往之振動致動器的剖面圖。 【元件符號說明】 1 基部支持構件 2 定子 3 振動手段 4 槽 -21 - 134-58711345871 IX. Description of the Invention: TECHNICAL FIELD The present invention relates to a vibration actuator, and more particularly to a vibration actuator that rotates a rotating body by ultrasonic vibration. [Prior Art] For example, in Patent Document 1, as shown in Fig. 18, a vibration actuator that rotates a spherical rotor 101 by ultrasonic vibration is disclosed. One end of the wire 102 is fixed to the inside of the rotor 101, and the rotor 101 is brought into pressure contact with the stator 103 by pulling the wire 102, and the piezoelectric element 104 is used to cause ultrasonic vibration of the stator 103 to rotate the rotor 101. The wire 102 for pressurizing the stator 103 by the rotor 101 passes through the inside of the stator 103 and the piezoelectric element 104, and the vibration actuator can be miniaturized as a whole. With the vibration actuator, a through hole 105 passing through the center of rotation thereof is formed inside the rotor 101, and one end of the wire 102 is inserted into the through hole 105, and is fixed to the inner wall surface of the through hole 105 via the bearing 106. Thereby, occurrence of twisting or the like of the wire 102 accompanying the rotation of the rotor 101 is prevented. Further, in order to prevent the wire 102 from interfering with the rotation of the rotor 101, the through hole 105 is formed to have a conical shape from the center of rotation of the rotor 101 toward the surface of the rotor 101 opposed to the stator 103. [Patent Document 1] Japanese Unexamined Patent Application Publication No. Publication No. JP-A------- Internally, it is not easy to form a through-hole 105 having a conical shape through the center of rotation thereof and from the center of rotation toward the surface of the rotor 101 opposed to the stator 103, which is laborious and expensive. Further, since it is necessary to provide the bearing mechanism 1〇6 for fixing one end portion of the wire 102 inside the through hole 105, the structure is complicated and manufacturing is difficult. The present invention has been made in order to solve such a problem, and an object thereof is to provide an actuator which is small but can be easily fabricated in a simple configuration. [Means for Solving the Problem] The vibration actuator of the present invention includes: a stator; a plurality of rollers respectively supported by the stator and sharing a single rotating shaft; and a connecting pin connecting the plurality of rollers; The means is coupled to the stator, and by causing the stator to vibrate, the contact portion of the stator and the plurality of rollers generates an elliptical or circular motion to rotate the plurality of rollers; and the pre-compression means is one end portion of the plurality of rollers The intermediate portion is coupled to the coupling pin, and the plurality of rollers pressurize the stator by pulling the coupling pin toward the stator. Further, "the middle portion of the plurality of rollers" means that among the plurality of rollers is located between the two outermost rollers. [Effect of the Invention] According to the present invention, a vibration actuator which is small in size and can be easily manufactured in a simple configuration can be realized. [Embodiment] Hereinafter, embodiments of the present invention will be described based on additional drawings. First Embodiment A first embodiment of a vibration actuator according to a first embodiment of the present invention is shown. This 1345871 vibration actuator is an ultrasonic actuator that uses ultrasonic vibration to rotate a rotating body, for example, a finger among the hands of a self-propelled robot. The vibration means 3 is disposed between the base supporting member 1 and the stator 2, and a groove 4 is formed on the opposite side of the surface of the stator 2 that is in contact with the vibration means 3, and the surface of the groove 4 is in contact with and supports the joint as a finger. 2 cylindrical rollers 5. The two rollers 5 are of the same size and are arranged parallel to each other, and are each configured to freely rotate about a common one. The connecting pin 6 passes through the center of each of the connecting pins 6, and the connecting pin 6 connects the two rollers 5, and the connecting pin 6 forms a common supporting shaft on both of the rollers 5. These rollers 5 have front end members 7 which are fixed to the outer peripheral portions of the rollers 5 of both sides and which rotate integrally with the rollers 5. Further, the vibration means 3 is connected to the drive circuit 8 for driving the vibration means 3. As shown in Fig. 2, the stator 2 has a through hole 9 at its center and has a substantially cylindrical shape as a whole. Further, the groove 4 formed to contact the surface of the stator 2 on which the roller 5 is placed passes through the center of the stator 2 and has a V-shaped cross-sectional shape. As shown in Fig. 3, the base supporting member 1 has a cylindrical body portion 10' having a recess formed therein, and a cylindrical insertion portion U formed to be smaller than the diameter of the body portion 10 and the body portion A through hole in which the recess of one turn communicates. The insertion portion 11 passes through the cylindrical vibration means 3, and the front end thereof is coupled to the inner wall surface of the through hole 9 of the stator 2, whereby the vibration means 3 is held by the main body portion of the base support member 1! Between the crucible and the stator 2, the stator 2, the vibrating means 3 and the base supporting member 1 as a whole have a substantially cylindrical outer shape. 1345871 Here, for convenience of explanation, the central axis of the cylindrical outer shape from the base support member 1 to the stator 2 is defined as a Z-axis, and the X-axis extends in a direction perpendicular to the Z-axis, and the Y-axis faces the Z-axis and X. The axis extends in the vertical direction. The vibration means 3 is a first piezoelectric element portion 31 and a second piezoelectric element portion 32 which are each in a flat shape which is located on the χγ plane and overlap each other. Inside the stator 2, the vibrating means 3, the insertion portion 11 of the base supporting member 1, and the main body portion 10, the rod 12 is passed through in the direction of the central axis, i.e., the Z-axis direction. One end of the rod 12 is located between the two rollers 5, and a substantially rectangular plate-like portion 13 is formed at one end of the rod 12. One end of the rod 12 is coupled to the joint pin 6 by the connecting pin 6 penetrating through the through hole formed in the plate portion 13. Here, the connecting pin 6 extends in the X-axis direction, and the plate-like portion 13 is located at the center of the two rollers 5 in the extending direction of the connecting pin 6, that is, in the X-axis direction, and the two rollers 5 are disposed to face each other in the plate-like portion 13. symmetry. Further, the structure is configured such that at least one of the connection pin 6 and each of the rollers 5 and the connecting pin 6 and the plate-like portion 13 of the lever 12 are coupled to be rotatable, so that the roller 5 can rotate the lever 12. The front end member 7 has a pair of projections 14 and 15 which are formed to protrude between the two rollers 5, and these projections 14 and 15 are arranged at intervals in the circumferential direction of the roller 5. The plate-like portion 13 is configured to abut the projections 14 and 15 by a surface on the opposite side to the surface facing the stator 2 and a surface on the side of the one, thereby restricting the rotation of the roller 5 to Abutting faces 16 and 17 of a given angular range. The abutting faces 16 and 17 and the projections 14 and 15 respectively constitute the first restricting portion and the second restricting portion 134.5871 of the present invention. Further, the abutting faces 16 and 17 of the plate-like portion 13 are accompanied by the hindrance of the rotation of the roller 5 The protrusions 14 and 15 are moved, and are connected to each other by a chamfered portion chamfered into a circular arc shape. The other end of the rod 12 is fixed to the spring seat member 18, which is located in the recess of the body portion 10 of the base support member 1, and is accommodated to be freely slidable within the recess. A spring 19, which is a traction device of the present invention, is disposed between the bottom surface 20 of the recess of the body portion 1 and the spring seat member 18, and the spring is placed! 9 The spring seat member 18 is urged in the opposite direction to the bottom surface 20 of the recess of the body portion 1〇. By the spring force of the spring 19, the coupling pin 6 is pulled toward the stator 2 through the spring seat member 18 and the rod 12, so that the roller 5 is brought into pressure contact with the stator 2. As shown in Fig. 4, the first piezoelectric element portion 31 and the second piezoelectric element portion 32 are disposed in a state of being insulated from the stator 2 and the base supporting member 1 via the insulating sheets 33 to 35. The first piezoelectric element portion 31 has a structure in which the electrode plates 31a, the piezoelectric element plates 31b, the electrode plates 31c, the piezoelectric element plates 31d, and the electrode plates 31e each having a disk shape are stacked in this order. Similarly, the second piezoelectric element The element portion 32 has a structure in which the electrode plate 32a each having a disk shape, the piezoelectric element plate 32b, the electrode plate 32c, the piezoelectric element plate 32d, and the electrode plate 32e are sequentially stacked. The electrode plate 31a and the electrode plate 31e disposed on both sides of the first piezoelectric element portion 31, and the electrode plate 32a and the electrode plate 32e disposed on both sides of the second piezoelectric element portion 32 are electrically grounded. Further, the electrode plate 31c disposed between the pair of piezoelectric element plates 31b and 31d of the first piezoelectric element portion 31, and the pair of piezoelectric element plates 32b 1345871 and 32d disposed between the second piezoelectric element portion 32 The electrode plates 32c are each pulled out of the terminals and connected. Further, the drive circuit 8 has detection means for monitoring the change in the stress acting on the vibration means 3 by the voltage of the third step, and the detection roller 5 reaches the predetermined end portion. As shown in Fig. 5, the 31b and 31d of the first piezoelectric element portion 31 are divided into two parts in the Y-axis direction, and are polarized so as to be oriented in the Z-axis direction (the deformation behavior is opposite to the thickness contraction, and the piezoelectricity is obtained. The element plates 31b are arranged opposite to each other. The pair of piezoelectric element plates of the second piezoelectric element portion 32 are divided into two, and are polarized integrally toward the Z-axis direction (thickness and contraction deformation action, piezoelectric element plate 32b) The vibration-driven drive circuit 8 of the first embodiment of the present invention is applied to the electrode plate 32c of the electrode element portion 32 of the first piezoelectric element portion 31 to apply a phase-to-phase current voltage. And the composite vibration generated by the longitudinal vibration of the y-axis and the y-axis direction by the vibration means 3 and the ellipses generated in the contact surface of the stator 2 are respectively produced by the vibration means 3, and the two rollers 5 are each centered around the X-axis with the joint pin 6 as a center. The two rollers 5 are simultaneously rotated in the same direction, and the rotation is performed to tilt the stator 2. The driving circuit 8 measures the vibration hand stress, and the two pairs of piezoelectric elements are divided according to the angular range. Each other has a reverse sentence) 3 1 d 32b and 32d are not Yin direction expansion and the piezoelectric element plate) electric element plate 32d is expanded with the operation of the actuator. When the plate 31c and the second plate are bent by 90 degrees in the direction of the bending vibration, the respective rollers 5 S move, and thus the rotational driving is performed. The distal end member 7 is in accordance with -10- 1345871. As shown in Fig. 6, the roller 5 is restricted by the abutment portion 16 of one of the distal end members 7 abutting against the abutting surface 16 of the plate-like portion 13 corresponding thereto. Turn further in the clockwise direction in Figure 6. Further, as shown in Fig. 7, by the other projection portion 15 of the distal end member 7 abutting against the abutting surface 17 of the plate-like portion 13 corresponding thereto, the roller 5 is restricted from rotating further counterclockwise in Fig. 7. . This limits the rotation of the roller 5 to a predetermined angular range. At this time, the rotation of the roller 5 is limited to an angular range of about 90°. Further, since the vibrating means 3 is sandwiched between the base supporting member 1 and the stator 2, and the roller 5 is pressed into contact with the stator 2, the pair of projections 14 and 15 of the distal end member 7 are respectively associated with the same. The abutting faces 16 and 17 of the plate-like portion 13 of the rod 12 abut against each other, and the stress acting on the vibrating means 3 via the connecting pin 6, the roller 5, and the stator 2 changes. Here, since the drive circuit 8 monitors the stress acting on the vibrating means 3 by measuring the voltage of the vibrating means 3, each of the pair of protrusions 14 and 15 of the distal end member 7 and the corresponding abutting surface 16 are detected. And the stress change of the vibration means 3 generated when the 17 is abutted, and the roller 5 can be detected to reach the respective end portions of the predetermined angular range. Therefore, it is not necessary to newly set a limit sensor or the like for detecting that the roller 5 has reached the movable limit. In this vibration actuator, since the cylindrical rollers 2 are connected by the joint pin 6, and one end portion of the rod 12 and the joint pin 6 are coupled and pulled, the roller 5 is added to the stator 2. Pressure, so that a vibration actuator that is simple in construction and can be easily fabricated can be realized. Since the rod 12 pulls the joint pin 6 at the center of the two rollers 5, the 134*5871 can press the respective rollers 5 against the stator 2 with a uniform force. Further, by arranging a spring having a different magnitude of the projectile thrust between the bottom surface 20 of the recessed portion of the body portion 10 and the spring seat member 18, the force for pressing the two rollers 5 against the stator 2 can be easily adjusted. size. Further, since the rod 12 passes through the inside of the stator 2, the vibration means 3, and the base supporting member 1, and the spring seat member 18 and the spring 19 are housed in the concave portion of the base supporting member 1, the entire vibration actuator is small. Further, since the two rollers 5 are in contact with each other on the surface of the groove 4 of the V-shaped cross section formed by the stator 2, the two rollers 5 can be stably supported by the stator 2. Further, since the stator 2 is vibrated by the vibration means 3, and the two rollers 5 are rotated only about one common rotation axis, stable operation can be performed, and the rotation of the roller 5 can be controlled with high precision. Therefore, by using a plurality of the vibration actuators, a robot arm that is similar to a human hand can be realized. (Second Embodiment) Next, a vibration actuator according to a second embodiment of the present invention will be described with reference to Fig. 8. In the second embodiment of the present invention, in the vibration actuator of the first embodiment, the two rollers 5 are provided on both sides of the two rollers 5 so as to be symmetrical with respect to the plate-like portion 13. That is, the four rollers 5 having the same size and shape are connected via the connecting pin 6, and are connected and pulled by the plate-like portion 13 of the rod 12 and the connecting pin 6, so that the roller 5 is pressed into contact with the stator 2. . The plate portion 13 of the rod 12 is located at the central portion of the four rollers 5 in the extending direction of the roller 5. Further, here, the illustration of the front end member 7 fixed to the outer portion of the outer roller -12-1345871 of the two rollers 5 located at the intermediate portion is omitted. The roller 5 is pressed against the stator 2 by joining the cylindrical four rollers 5 with the joint pin 6 and pulling the joint pin 6 by the rod 12 passing through the stator 2' vibrating means 3 and the inside of the base supporting member 1. Since it is in contact with the above-described first embodiment, it is possible to realize a vibration actuator which is small in size and can be easily produced with a simple structure. In the second embodiment, the four rollers 5 are pressed into contact with the stator 2, and the four rollers 5 are rotationally driven by the vibration of the stator 2, and the distal end member 7 is tilted. High torque 'and reduces wear on the contact portions of the rollers 5 and 2 . Further, since the four rollers 5 are not only arranged to be symmetrical with respect to the plate-like portions 13 of the rods 12 but also have the same size and shape as each other, stable rotation can be performed. Further, an even number of rollers 5 may be disposed on both sides of the four rollers 5 so as to be symmetrical to each other with respect to the plate portions 13. Third Embodiment Next, a vibration actuator according to a third embodiment of the present invention will be described with reference to Fig. 9'. In the third embodiment, in place of the above-described second embodiment, two rollers 5 having the same size are provided on both sides of the two rollers 5 located at the intermediate portion, and instead each has a smaller size than the roller 5. The two rollers 41 of the diameter are disposed to be symmetrical to each other with respect to the plate-like portions 13. A contact portion 42 having a sectional shape corresponding to the step of the four rollers 5 and 41 is formed along the extending direction of the connecting pin 6 on the surface opposite to the surface in contact with the vibrating means 3 of the stator 2. The rollers 5 1345871 and the rollers 41 pressurize the stator 2 by pulling the coupling pin 6' with the rod 12. Even in such a configuration, the same effects as those of the second embodiment described above can be obtained. Further, in the third embodiment, since the two rollers 41 each having a smaller diameter than the roller 5 are disposed on both sides of the two rollers 5, the vibration actuator can be made smaller. Further, conversely, two rollers 41 having a small diameter may be disposed in the intermediate portion, and the roller 5 may be disposed on both sides thereof. Further, an even number of rollers may be disposed on both sides of the four rollers 5 and 41 so as to be symmetrical to each other with respect to the plate portions 13. At this time, the newly added roller may have the same diameter as the rollers 5 and 41, or may have a diameter different from that of the rollers 5 and 41. In either case, on the side opposite to the surface in contact with the vibration means 3 of the stator 2, contact portions having cross-sectional shapes corresponding to the rollers are formed along the extending direction of the coupling pin 6, and the roller-to-stator 2 is provided. Pressurized contact is preferred. Further, in the first to third embodiments described above, the case where an even number of rollers are provided is not limited thereto, and three or more odd-numbered rollers may be provided. For example, as shown in Fig. 10, the three rollers 5 can be connected and used by the connecting pin 6. In this case, the stator 2 is formed with two through holes 9 along the axial direction thereof, and one end portion of the rod 12 branched into two is inserted into the through hole 9 and joined by the plate portion 13 and the connecting pin 6. Thereby, the connecting pin 6 is pulled by the rod 12, and the three rollers 5 can be brought into press contact with the stator 2. In the above-described first embodiment, the second embodiment may be replaced by two cylindrical rollers 14-1345871 wheels 5, and as shown in Fig. 11, two rollers 51 having a truncated cone shape are used instead. The large diameter portions 52 of the two rollers 51 are disposed to face each other. On the surface opposite to the surface in contact with the vibration means 3 of the stator 2, a contact portion 53 having a cross-sectional shape corresponding to the two rollers 51 is formed along the extending direction of the coupling pin 6, and the rollers 51 are added to the stator 2 Pressure contact. Further, the front end member is fixed to the outer peripheral portion of the two rollers 51, not shown. Even in such a configuration, the same effect as in the first embodiment can be obtained. Further, as shown in Fig. 12, the large diameter portions 52 of the two rollers 51 may be arranged to face each other in opposite directions. Further, the outer circumferential surface of each of the rollers 51 that abuts on the stator 2 in FIGS. 11 and 12 may be formed as a notch that is curved toward the central axis or curved in a direction opposite to the central axis. muster. Further, as the rollers of the second and third embodiments described above, the truncated conical roller 51 can be used. According to the fifth embodiment, in the first embodiment described above, instead of the two rollers 5 of the cylindrical shape, as shown in Fig. 13, the two rollers 61 having a hemispherical shape are used instead. The portions 62 are arranged to face each other. On the surface opposite to the surface in contact with the vibration means 3 of the stator 2, a contact portion 63 having a cross-sectional shape corresponding to the two rollers 61 is formed along the extending direction of the coupling pin 6, and the rollers 61 are added to the stator 2 Pressure contact. Further, the front end member is not fixed to the outer peripheral portion of the two rollers 61. Even in such a configuration, the same effect as that of the first embodiment can be obtained. Further, as shown in Fig. 14, the flat portions 62 of the two rollers 61 may be arranged to face each other in opposite directions. Further, as the rollers of the second and third embodiments described above, the hemispherical roller 61 can also be used. In the sixth embodiment, in the first to fifth embodiments described above, the rectangular plate-like portion 13 is provided at one end of the rod 12, but one of the plate-like portions π may be abutted against the surface 16 and The portion of 17 is notched, and as shown in Fig. 15, for example, oblique abutting faces 71 and 72 are formed. In this case, by the one of the front end members, the projections abut against the corresponding abutting faces 71 and 72, and the rotation of the roller is limited to a predetermined angular range larger than 90°. That is, the angle range in which the rotation of the roller is restricted can be changed by selecting the protruding height of the protruding portion and the angle of the abutting surface. Further, the projection may be provided instead of the front end member instead of the roller adjacent to the plate portion 13. Further, the protruding portion may be provided on the plate portion 13' and the abutting surface may be provided to the front end member or the roller. Further, it is not limited to a combination of the protruding portion and the abutting surface, and various first restricting portions and second restricting portions can be provided, and the rotation of the roller can be restricted by engaging with each other. For example, the combination of the protrusion and the protrusion or the abutting surface and the abutting surface may be used as the first restricting portion and the second restricting portion. Seventh Embodiment Next, a vibration actuator according to a seventh embodiment of the present invention will be described with reference to Fig. 16 . In the seventh embodiment, the vibration-induced 16-16345871 actuator of the first embodiment is connected to and pulled by the wire member 81 and the connecting pin 6 instead of the rod 12. The wire member 81 is inserted into the center axis direction of the stator 2, the vibration means 3, and the base supporting member 1, that is, in the Z-axis direction. One end of the wire 81 is located in the extending direction of the connecting pin 6, that is, in the central portion of the two rollers 5 in the X-axis direction, and is coupled to the connecting pin 6. The other end of the wire 81 is fixed to the spring seat member 18 in the recess of the body portion 1 of the base support member 1, and the coupling pin 6 is pulled toward the stator 2 via the spring seat member 18 and the wire 81 by the spring force of the spring 19. Thus, the roller 5 is brought into pressure contact with the stator 2. Further, a front end member 82 having a substantially flat bottom surface is fixed to the outer periphery of the two rollers 5. Since the cylindrical pin 2 is joined by the joint pin 6, and the joint pin 6 is pulled by the wire 81 passing through the stator 2, the vibration means 3, and the inside of the base support member 1, the roller 5 is pressed against the stator 2. Since it is in contact with the above-described first embodiment, it is possible to realize a vibration actuator which is small and easy to manufacture with a simple structure. Since the wire 81 pulls the joint pin 6 at the center portion of the two rollers 5, the two rollers 5 can pressurize the stator 2 with a uniform force. Further, the spring having the different magnitude of the projectile thrust is disposed between the bottom surface 20 of the concave portion of the main body portion 10 and the spring seat member 18, or the length of the wire 81 from the joint pin 6 to the spring seat member 18 is adjusted. Moreover, the magnitude of the pressing force of the two rollers 5 on the stator 2 can be easily adjusted. Further, in the second to fifth embodiments, instead of the rod 1 2, the wire 81 and the connecting pin 6 may be connected and pulled, and the roller may be pressed against the stator 2 . -17- 1345871 In addition, in the above-described first to seventh embodiments, the rod 12 and the wire rod 81 are each pulled by the spring thrust of the spring 19, but instead of the spring 19, the air pressure or the oil pressure may be used instead. The device is connected to the other end of the rod 12 and the wire 81, and draws the rod 12 and the wire 81. In the traction device using air pressure or oil pressure, the magnitude of the force of the drawbar 12 and the wire 81 can be easily controlled. Therefore, the amount of pressure applied to the stator 2 by the two rollers 5 can be easily adjusted. For example, when the vibration means 3 is not driven, if the traction means is controlled so that the traction force of the rod 12 and the wire 81 becomes larger than that of the vibration means 3, the holding between the roller 5 and the stator 2 at rest can be maintained. The torque is increased. Eighth Embodiment Next, a vibration actuator according to an eighth embodiment of the present invention will be described with reference to Fig. 17. In the eighth embodiment of the present invention, in the vibration actuator of the first embodiment, instead of the rod 12, the connecting pin 6 is pulled by the wire 91 made of elastic linear rubber, resin, spring or the like. . The wire 91 is passed through the stator 2, the vibration means 3, and the inside of the base supporting member 1, and one end of the wire 91 is located at the center of the two rollers 5, and is coupled to the coupling pin 6. Further, the fixing member 92 is fixed in the concave portion of the body portion 10 of the base supporting member 1, and the other end portion of the wire 91 is fixed to the fixing member 92»the wire 91 is attached to the state in which the predetermined tension is generated, and is utilized. The tension of the wire 91 pulls the coupling pin 6 toward the stator 2, and the roller 5 presses the stator 2 into pressure. According to this configuration, as in the first embodiment, a vibration-induced-18-1345871 actuator can be realized, which is small in size, simple in construction, and easy to manufacture, and can make the respective rollers 5 have uniform force on the stator 2. Pressurize the contact. Further, by adjusting the degree of elongation of the wire member 91, the magnitude of the tension of the wire member 91 can be changed, and the magnitude of the pressing force applied to the two rollers 5 of the stator 2 can be easily adjusted. Further, in the second to fifth embodiments described above, the wire rod 91 and the joint pin 6 are connected and pulled by the replacement rod 12', so that the roller can pressurize the stator 2. Further, in the first to eighth embodiments described above, the roller can be rotated one or more times by omitting the distal end member. Further, although the other end portions of the rod 12 and the wires 81, 91 are located in the concave portion of the body portion 10 of the base supporting member 1, they may be located in the through holes 9 of the stator 2. Further, in each of the above embodiments, the drive circuit 8 does not measure the voltage of the vibration means 3, but by measuring the current, the vibration frequency, the phase, and the like of the vibration means 3, the stress acting on the vibration means 3 can be monitored. In this case, if the rotation of the roller is restricted to a predetermined angular range, the drive circuit 8 can detect the end of the roller up to a predetermined angular range in accordance with the change in the stress of the vibration means 3. Further, the detection means for detecting the stress acting on the vibration means 3 and detecting the end of the roller reaching the predetermined angular range in response to the change in the stress may be provided separately from the drive circuit 8 without being built in the drive circuit 8'. . Further, although the phase of the alternating voltage applied from the driving circuit 8 to each piezoelectric element portion is shifted by 90 degrees, it may be changed, and is not limited to 90 -19 - 1345871 degrees. Also, the voltage 値 of the applied AC voltage can be changed. The elliptical vibration generated in the stator 2 can be controlled by controlling the AC voltage in various ways. Further, it is also possible to generate a composite vibration composed of a plurality of kinds of vibrations which are not orthogonal to each other, and to rotate a plurality of rollers around a common one. Further, instead of synthesizing the two kinds of vibrations generated by the different piezoelectric element portions to generate the composite vibration, one piezoelectric element portion may be polarized into a plurality of pieces, and the applied to each of the polarized electrodes may be individually controlled. Voltage. In other words, a current obtained by combining AC voltages having different phases and amplitudes may be applied to each of the polarized electrodes, and a composite vibration may be generated by a single piezoelectric element portion. Further, in each of the above embodiments, the contact portion between the stator 2 and the roller is caused to have an elliptical motion, but the circular motion can be generated by controlling the amplitude in each axial direction. Moreover, the vibration actuator can be applied not only to the fingers of the robot arm, but also to the various parts of the joint, such as the foot of a self-propelled robot. That is, the roller of the vibration actuator can be used as a joint. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view showing a vibration actuator according to a first embodiment of the present invention. Fig. 2 is a perspective view showing the stator of the first embodiment. Fig. 3 is a cross-sectional view showing the vibration actuator of the first embodiment. Fig. 4 is a partial cross-sectional view showing the configuration of a vibration means used in the first embodiment. Fig. 5 is a perspective view showing a polarization direction of two pairs of piezoelectric element plates of the piezoelectric element means -20 - 1345871 used in the first embodiment. Fig. 6 is a cross-sectional view showing an operation state of the vibration actuator of the first embodiment. Fig. 7 is a cross-sectional view showing an operation state of the vibration actuator of the first embodiment. Fig. 8 is a structural view showing the vicinity of the roller in the second embodiment. Fig. 9 is a structural view showing the vicinity of the roller in the third embodiment. Fig. 10 is a structural view showing the vicinity of a roller in a modification of the first embodiment. Fig. 11 is a structural view showing the vicinity of the roller in the fourth embodiment. Fig. 12 is a structural view showing the vicinity of a roller in a modification of the fourth embodiment. Fig. 13 is a structural view showing the vicinity of the roller in the fifth embodiment. Fig. 14 is a structural view showing the vicinity of the roller in the modification of the fifth embodiment. Fig. 15 is a view showing a plate-like portion of the rod of the sixth embodiment. Fig. 16 is a cross-sectional view showing the vibration actuator of the seventh embodiment. Fig. 17 is a cross-sectional view showing the vibration actuator of the eighth embodiment. Fig. 18 is a cross-sectional view showing a conventional vibration actuator. [Explanation of component symbols] 1 Base support member 2 Stator 3 Vibrating means 4 Slot -21 - 134-5871
5,41,51,61 滾輪 6 連結銷 7,82 前端構件 8 驅動電路 9 貫穿孔 10 本體部 11 插入部 12 桿 13 板狀部 14,15 突起部 16,17,71,72 抵接面 18 彈簧座構件 19 彈簧 20 底面 3 1 第1壓電元件部 32 第2壓電元件部 33 〜35 絕緣片 3 1 a, 3 1 c，3 1 e 電極板 31b，31d 壓電元件板 42,63,53 接觸部 52 大徑部 62 平面部 8 1,91 線材 8 1,91 線材 -225,41,51,61 Roller 6 Connecting pin 7,82 Front end member 8 Drive circuit 9 Through hole 10 Main body portion 11 Insertion portion 12 Rod 13 Plate portion 14, 15 Projection portion 16, 17, 71, 72 Abutment surface 18 Spring seat member 19 Spring 20 bottom surface 3 1 first piezoelectric element portion 32 second piezoelectric element portion 33 to 35 insulating sheet 3 1 a, 3 1 c, 3 1 e electrode plate 31b, 31d piezoelectric element plate 42, 63 , 53 contact part 52 large diameter part 62 flat part 8 1,91 wire 8 1,91 wire-22