1359236 六、發明說明 【發明所屬之技術領域】 本發明係關於擺動齒輪裝置，詳而言之，係關於可利 用於要求高定位精度、平順的旋轉及安靜性之機器人、工 作機械、液晶暨半導體製造裝置等而具有高精度及高減速 比的擺動齒輪裝置。 【先前技術】 以往，關於輕量、緊致、不須使用複雜的機構及構造 即可獲得高精度及高減速比的齒輪裝置，已知的是波動齒 輪裝置。波動齒輪裝置，是以具備波動產生器的構造爲代 表，該波動產生器，是讓彈性撓曲嚙合式的可撓性外齒齒 輪局部地嚙合於環狀的剛性內齒齒輪，並利用彈性的可撓 性’而使其嚙合位置依兩齒輪的齒數差沿圓周方向移動 (參照專利文獻1)。 代表性的擺動齒輪裝置，其具體構造係具備：環狀的 剛性內齒齒輪、配置於其內側之杯狀的可撓性外齒齒輪、 嵌入其內側之橢圓形的波動產生器。可撓性外齒齒輪，是 被波動產生器撓曲成橢圓形，而使其橢圓形的長軸方向的 兩端部分的外齒嚙合於內齒齒輪內周面的內齒。若藉由馬 達旋轉軸等使波動產生器旋轉，兩齒輪的嚙合位置會沿圓 周方向移動。一般而言，由於內齒齒輪是固定的，故從杯 狀的可撓性外齒齒輪，會按照兩齒輪的齒數差而輸出大幅 減速後的旋轉》 -5- 1359236 波動產生器，係具備橢圓形的凸輪部和軸承。該凸輪 部的作用，是讓可撓性外齒齒輪的外齒往半徑方向撓曲以 局部地嚙合於剛性內齒齒輪的內齒。軸承係具備滾珠、內 環以及外環。內環是固定於凸輪部的外周，外環是嵌合於 可撓性外齒齒輪的外齒的背面側，隨著凸輪部的旋轉而配 合可撓性外齒齒輪發生彈性變形。 〔專利文獻1〕日本特開平1 0- 1 1 0790號公報 【發明內容】 在習知代表性的波動齒輪裝置，在波動產生器，由於 是使用內環呈橢圓形且外環可彈性變形的特殊軸承，而有 無法使用市售軸承的問題。另外，由於該軸承的外環厚度 薄，在有過負載作用時，起因於在軸承的滾珠和滾珠之間 發生的外環撓曲，可能發生剛性內齒齒輪和可撓性外齒齒 輪的嚙合瞬間移位之棘齒效應（跳齒）現象。另外，由於高 速旋轉側的波動產生器的凸輪部的長軸長度相對於剛性內 齒齒輪的內周的直徑的比例大，而有慣性力矩變大的傾 向。 本發明的目的是爲了提供一種齒輪裝置，其可使用市 售的軸承，即使有過負載作用著仍不致發生棘輪效應現 象，且能減低高速旋轉側的慣性力矩。 本發明的擺動齒輪裝置，爲了解決上述課題，係具 備：環狀的剛性內齒齒輪、配置於該剛性內齒齒輪的內側 之環狀的可撓性外齒齒輪、嵌入該可撓性外齒齒輪的內側 -6- 1359236 之擺動產生器；讓前述可撓性外齒齒輪撓曲 剛性內齒齒輪的中心而對置的2處局部地讓 藉由前述擺動產生器的旋轉使兩齒輪的嚙合 向移動，藉此在前述剛性內齒齒輪及前述可 之間產生相對旋轉而構成的擺動齒輪裝置， 前述擺動產生器係具有2個圓形輪廓的 心輥係具備：繞該擺動產生器的旋轉軸以既 旋轉之圓形輪廓的偏心凸輪、嵌合於該偏心 軸承、以及配置於該軸承的外周之轉輪，2 疊配置成使各偏心輥的圓形輪廓的中心朝互 以前述既定量偏離前述旋轉軸； 藉由使前述偏心輥的外周面接觸前述可 的內周面，而以該可撓性外齒齒輪和前述剛 前述2處局部地嚙合的方式讓可撓性外齒齒 可撓性外齒齒輪的嚙合位置的曲率半徑F ⑴（2)。 2χ( ε +R) = mxZc (1) 2x7T xR + 4x ε =π xmxZf (2) 其中， R:可撓性外齒齒輪的嚙合位置的曲率 ε :偏心輥的偏心量 m :剛性內齒齒輪及可撓性外齒齒輪的 ，在隔著前述 兩齒輪嚙合， 位置沿圓周方 撓性外齒齒輪 其特徵在於： 偏心輥，各偏 定量偏心進行 凸輪的外周之 個偏心輥是重 相相反的方向 撓性外齒齒輪 性內齒齒輪在 輪燒曲時，該 L是滿足下式 徑 數 13592361359236 VI. Description of the Invention [Technical Field] The present invention relates to a swing gear device, and more particularly to a robot, a work machine, a liquid crystal and a semiconductor that can be utilized for requiring high positioning accuracy, smooth rotation and quietness. A swing gear device having a high precision and a high reduction ratio, such as a manufacturing device. [Prior Art] Conventionally, a gear device having a high precision and a high reduction ratio can be obtained with a light weight, a compact, and a complicated mechanism and structure, and a wave gear device is known. The wave gear device is represented by a structure having a wave generator which partially engages a flexible flexural meshing flexible externally toothed gear to an annular rigid internally toothed gear and utilizes elasticity. The flexible portion is moved in the circumferential direction in accordance with the difference in the number of teeth of the two gears (see Patent Document 1). A typical rocking gear device has a specific structure including an annular rigid internally toothed gear, a cup-shaped flexible externally toothed gear disposed inside, and an elliptical wave generator embedded in the inner side. The flexible externally toothed gear is an internal tooth that is deflected into an elliptical shape by the wave generator, and the external teeth of the both end portions in the long axis direction of the elliptical shape are engaged with the inner peripheral surface of the internal gear. When the wave generator is rotated by the motor rotating shaft or the like, the meshing positions of the two gears move in the circumferential direction. In general, since the internal gear is fixed, the cup-shaped flexible external gear will output a large deceleration according to the difference in the number of teeth of the two gears. -5- 1359236 Wave generator with ellipse Shaped cam and bearing. The cam portion functions to deflect the external teeth of the flexible externally toothed gear in the radial direction to partially mesh with the internal teeth of the rigid internally toothed gear. The bearing has a ball, an inner ring and an outer ring. The inner ring is fixed to the outer circumference of the cam portion, and the outer ring is fitted to the back side of the external teeth of the flexible externally toothed gear, and the flexible externally toothed gear is elastically deformed in accordance with the rotation of the cam portion. [Patent Document 1] Japanese Laid-Open Patent Publication No. Hei No. Hei. No. Hei. No. Hei. No. Hei. Special bearings, but there are problems with the use of commercially available bearings. In addition, due to the thin outer ring thickness of the bearing, the engagement of the rigid internal gear and the flexible external gear may occur due to the outer ring deflection occurring between the ball and the ball of the bearing during an overload. The ratcheting effect (jumping tooth) phenomenon of instantaneous displacement. Further, since the ratio of the major axis length of the cam portion of the wave generator on the high-speed rotation side to the diameter of the inner circumference of the rigid internally toothed gear is large, there is a tendency that the moment of inertia becomes large. SUMMARY OF THE INVENTION An object of the present invention is to provide a gear unit which can use a commercially available bearing so that ratcheting does not occur even if an overload is applied, and the moment of inertia on the high speed rotating side can be reduced. In order to solve the above problems, the swing gear device of the present invention includes an annular rigid internal gear, an annular externally toothed gear disposed inside the rigid internally toothed gear, and the flexible external tooth. a swing generator of the inner side of the gear -6 - 1359236; let the flexible external tooth gear flex the center of the rigid internally toothed gear at two opposite positions to partially engage the two gears by the rotation of the aforementioned swing generator a rocking gear device configured to move relative to each other between the rigid internally toothed gear and the arranging device, wherein the oscillating generator has two circular contoured core rollers: rotating around the oscillating generator The eccentric cam having a circular contour that rotates, the eccentric bearing that is fitted to the eccentric bearing, and the outer circumference of the bearing are arranged in a stack so that the centers of the circular contours of the eccentric rollers are aligned with each other. Deviating from the rotation axis; by allowing the outer circumferential surface of the eccentric roller to contact the inner circumferential surface, the flexible external gear is partially meshed with the aforementioned two places to allow flexibility An outer radius of curvature of the flexible teeth meshing position of teeth of the gear F ⑴ (2). 2χ( ε +R) = mxZc (1) 2x7T xR + 4x ε =π xmxZf (2) where R: curvature of the meshing position of the flexible externally toothed gear ε: eccentricity of the eccentric roller m: rigid internal gear And the flexible externally toothed gear, which is meshed with the two gears, and is circumferentially flexible. The externally toothed gear is characterized by: an eccentric roller, each of which is eccentrically biased to perform an outer circumference of the cam, and the eccentric roller is opposite in phase When the direction of the flexible external gear gear internal gear is burned, the L is equal to the following formula: 1359236
Zc :剛性內齒齒輪的齒數 Zf:可撓性外齒齒輪的齒數。 另外，本發明的擺動齒輪裝置，爲了解決上 係具備：環狀的剛性內齒齒輪、配置於該剛性內 內側之環狀的可撓性外齒齒輪、嵌入該可撓性外 內側之擺動產生器；讓前述可撓性外齒齒輪撓曲 前述剛性內齒齒輪的中心而對置的2處局部地讓 合，藉由前述擺動產生器的旋轉使兩齒輪的嚙合 周方向移動，藉此在前述剛性內齒齒輪及前述可 齒輪之間產生相對旋轉而構成的擺動齒輪裝置， 於： 前述擺動產生器係具有2個圓形輪廓的偏心 心輥係具備：繞該擺動產生器的旋轉軸以既定量 旋轉之圓形輪廓的偏心凸輪、嵌合於該偏心凸輪 軸承、以及配置於該軸承的外周之轉輪，2個偏 疊配置成使各偏心輥的圓形輪廓的中心朝互相相 以前述既定量偏離前述旋轉軸： 藉由使前述偏心輥的外周面接觸前述可撓性 的內周面，而以該可撓性外齒齒輪的齒寬中央部 性內齒齒輪在前述2處局部地嚙合的方式讓可撓 輪撓曲時，在未嚙合剛性內齒齒輪的狀態下之該 齒齒輪的假想開口部的曲率半徑R〇以及偏心量e 下式（3)(4)。 述課題， 齒齒輪的 齒齒輪的 ，在隔著 兩齒輪嚙 位置沿圓 撓性外齒 其特徵在 輥，各偏 偏心進行 的外周之 心輥是重 反的方向 外齒齒輪 和前述剛 性外齒齒 可撓性外 〇係滿足 1359236 2χ( ε 〇 + R〇) = mx {Zc + (Zc - Zf)x0.5xb/S} (3) 2%π xR〇 + 4xe 〇= π xmxZf (4) 其中，Zc : Number of teeth of rigid internal gears Zf: Number of teeth of flexible external gears. In addition, the swing gear device of the present invention includes a ring-shaped rigid internally toothed gear, a ring-shaped flexible externally toothed gear disposed inside the rigid inner side, and a wobble formed in the outer side of the flexible outer side. The two flexible external gears are flexibly bent at the center of the rigid internal gear to face the two places, and the rotation of the swing generator is used to move the meshing circumferential direction of the two gears. a oscillating gear device configured by a relative rotation between the rigid internally toothed gear and the movable gear, wherein: the oscillating generator has an eccentric roller system having two circular contours: a rotation axis around the oscillating generator An eccentric cam that quantitatively rotates a circular contour, is fitted to the eccentric cam bearing, and a rotating wheel disposed on an outer circumference of the bearing, and two offsets are arranged such that the centers of the circular contours of the eccentric rollers face each other The predetermined amount of deviation from the rotation axis is obtained by contacting the outer peripheral surface of the eccentric roller with the flexible inner peripheral surface, and the tooth width central portion of the flexible externally toothed gear When the flexible wheel is flexed in the manner of partially engaging the two places, the radius of curvature R 假 of the imaginary opening of the tooth gear and the eccentricity e in the state in which the rigid internal gear is not meshed is expressed by the following formula (3) ( 4). The problem is that the tooth gear of the tooth gear is characterized by a circular flexible external tooth at a position interposed between the two gears, and the outer peripheral core roller is in the direction of the reciprocal tooth and the rigid external tooth. The tooth flexible outer 满足 system satisfies 1359236 2χ( ε 〇+ R〇) = mx {Zc + (Zc - Zf)x0.5xb/S} (3) 2%π xR〇+ 4xe 〇= π xmxZf (4) among them,
Ro:可撓性外齒齒輪的假想開口部的曲率半徑 ε 〇 :假想開口部的偏心量 m :剛性內齒齒輪及可撓性外齒齒輪的模數 Z c :剛性內齒齒輪的齒數Ro: radius of curvature of the imaginary opening of the flexible externally toothed gear ε 〇 : eccentricity of the imaginary opening m: modulus of the rigid internal gear and the flexible external gear Z c : number of teeth of the rigid internal gear
Zf:可撓性外齒齒輪的齒數 b:可撓性外齒齒輪的齒寬 S:可撓性外齒齒輪的底面至齒寬中央的長度。 依據上述構造，偏心凸輪爲圓形輪廓，因此不須使用 具備橢圓形的內環和可彈性變形的外環之特殊軸承’作爲 嵌合於偏心凸輪的外周的軸承可使用市售的軸承。另外， 偏心輥是在軸承的外周具備轉輪，且使該轉輪的外周面和 可撓性外齒齒輪的內周面接觸，因此不須使用在可撓性外 齒齒輪的外齒背面具備可彈性變形的薄型外環之軸承，而 能抑制起因於可彈性變形的薄型外環的徺曲而發生之棘齒 效應現象。再者，擺動產生器具有2個偏心輥，且是重疊 配置成使各偏心輥的圓形輪廓的中心朝互相相反的方向以 既定量偏離前述旋轉軸，因此不須使用橢圓形的凸輪，而 能降低偏心凸輪的直徑相對於剛性內齒齒輪的內周直徑的 比例，因此可減低高速旋轉側的慣性力矩。 依據本發明的擺動齒輪裝置，可使用市售的軸承，即 -9- 1359236 使有過負載作用著仍不致發生棘輪效應現象，且能減低高 速旋轉側的慣性力矩。 【實施方式】 以下參照圖式來說明本發明的一實施形態之擺動齒輪 裝置。 第1圖係本發明的一實施形態之擺動齒輪裝置的分解 立體圖。如第1圖所示，擺動齒輪裝置10是由：環狀的 剛性內齒齒輪20、可彈性變形的環狀的可撓性外齒齒輪 30、擺動產生器40所構成。 剛性內齒齒輪20係具備：形成於內周面的內齒部 21、用來將該剛性內齒齒輪20固定於固定構件（未圖示） 之固定用螺栓孔22。可撓性外齒齒輪30呈杯狀，並具 備：形成於杯體的開口側的外周面之外齒部31、用來連 接於輸出旋轉軸（未圖示）之輸出旋轉軸安裝用螺栓孔33。 在外齒部31形成齒寬WW的外齒。擺動產生器40具備2 個偏心輥41和輸入旋轉軸安裝部45。 第2圖係本發明的一實施形態之擺動齒輪裝置的截面 圖，是包含擺動產生器的旋轉軸和被擺動產生器撓曲之可 撓性外齒齒輪的長軸之平面的截面圖。第3圖係第2圖的 Α-Α線截面圖。如第2圖及第3圖所示，擺動齒輪裝置 10是在剛性內齒齒輪20的內側配置可撓性外齒齒輪30， 在可撓性外齒齒輪30嵌入擺動產生器40以使可撓性外齒 齒輪30發生撓曲，藉此，形成於剛性內齒齒輪20的內齒 -10- I359236 部21的內齒和形成於可撓性外齒齒輪30的外齒部31的 外齒，在隔著剛性內齒齒輪20的中心而對置之2處’亦 即嚙合位置P及Q進行嚙合。 剛性內齒齒輪20是由剛性體構成。可撓性外齒齒輪 30，其整體是由可撓性材料構成亦可，但至少除了設置於 杯狀底面的環狀的輸出旋轉軸安裝部32以外是由可撓性 材料構成，且形成可彈性變形的薄型構造。輸出旋轉軸安 裝部32是形成比其他部分厚，並設有輸出旋轉軸安裝用 螺栓孔33。另外，外齒部31也是形成可彈性變形。 擺動產生器40具有2個圓形輪廓的偏心輥41。偏心 輥41係具備：繞擺動產生器的旋轉軸XX以既定量偏心 而進行旋轉之圓形輪廓的偏心凸輪42、嵌合於偏心凸輪 42的外周之軸承43、配置於軸承43外周之轉輪44。偏 心凸輪42是固定在輸入旋轉軸安裝部45。 第4圖係2個偏心輥的配置狀態的示意說明圖。如第 4圖所示，2個偏心輥41是重疊配置成，使各偏心輥的圓 形輪廓的中心41a朝互相相反的方向以既定量（ε)偏離擺 動產生器40的旋轉軸XX。由於擺動產生器40具有這樣 的形狀，若在可撓性外齒齒輪30的內側嵌入擺動產生器 4〇，偏心輥41的外周面會接觸可撓性外齒齒輪30的外齒 部31的內周面而使可撓性外齒齒輪30發生撓曲，可撓性 外齒齒輪30的外齒和剛性內齒齒輪20的內齒會在隔著剛 性內齒齒輪20中心而對置的2處進行嚙合（參照第3 圖）。 -11 - 1359236 如以上所說明，本實施形態的擺動齒輪裝置10，不 同於習知之波動齒輪裝置的波動產生器（具備：橢圓形的 凸輪和具有可彈性變形的外環的軸承），其所具備的擺動 產生器40，是具有2個圓形輪廓的偏心輥41，且重疊配 置成使各偏心輥41的圓形輪廓的中心41a朝互相相反的 方向以前述既定量偏離擺動產生器40的旋轉軸XX。因 此，本實施形態的擺動齒輪裝置10，偏心輥41所使用的 偏心凸輪42爲圓形輪廓，不須使用具備橢圓形的內環和 可彈性變形的外環之特殊軸承，因此嵌合於偏心凸輪42 外周的軸承43可使用市售的軸承。另外，由於不須使用 在可撓性外齒齒輪的外齒背面具備可彈性變形的薄型外環 之軸承，藉由在軸承43外側設置轉輪44，可抑制起因於 可彈性變形的薄型外環的撓曲而發生之棘齒效應現象。再 者，由於偏心凸輪42的直徑相對於剛性內齒齒輪20直徑 的比例降低，可減低高速旋轉側的慣性力矩。 接著，使用第5圖來說明擺動齒輪裝置10的動作。 第5圖係本發明的一實施形態之擺動齒輪裝置的動作的說 明圖。 本實施形態的擺動齒輪裝置10,是在擺動產生器40 的輸入旋轉軸安裝部45安裝輸入旋轉軸，若藉由馬達等 進行驅動，擺動產生器40就會開始旋轉。 如第5圖所示，在旋轉前，剛性內齒齒輪20之斜線 所示的內齒、和可撓性外齒齒輪30之塗黑所示的外齒互 相嚙合。若擺動產生器40進行90度旋轉，嚙合位置會沿 -12- 1359236 圓周方向移動90度。本實施形態的擺動齒輪裝置1〇，剛 性內齒齒輪20的內齒齒數和可撓性外齒齒輪3〇的外齒齒 數的差爲2齒，若使擺動產生器40在嚙合位置沿圓周方 向移動的狀態下進行3 60度旋轉，爲了使嚙合位置回到剛 性內齒齒輪20的斜線所示的內齒，可撓性外齒齒輪30必 須旋轉外齒齒數加上2齒的量。亦即，在擺動產生器40 旋轉360度時，和斜線所示的內齒嚙合的對象是和塗黑所 示的外齒隔2齒的外齒。結果，可撓性外齒齒輪30是以 2齒的分量朝與擺動產生器40的旋轉方向相反的方向進 行相對旋轉。本實施形態的擺動齒輪裝置1 0，由於將剛 性內齒齒輪20固定成無法進行相對旋轉，而能夠從可撓 性外齒齒輪30輸出對應於內齒和外齒的齒數差而大幅減 速後的旋轉。 在此，在可撓性外齒齒輪30的內側嵌入擺動產生器 40，並使偏心輥41的外周面接觸可撓性外齒齒輪30的內 周面，而以可撓性外齒齒輪30和剛性內齒齒輪20在2處 進行局部地嚙合的方式讓可撓性外齒齒輪30撓曲時，可 撓性外齒齒輪30的嚙合位置的曲率半徑R滿足下式 (1)(2)。 (1) 2x( e +R) = mxZc (2) 2χ π xR + 4x ε = π xmxZf 其中，R爲可撓性外齒齒輪30的嚙合位置的曲率半 -13- 1359236 徑，ε爲偏心輥41的偏心量，m爲剛性內齒齒輪20及可 撓性外齒齒輪30的模數，Zc爲剛性內齒齒輪20的齒 數，Zf爲可撓性外齒齒輪30的齒數。 用第6圖來說明上述式（1)。第6圖係顯示本發明的 一實施形態之擺動齒輪裝置的剛性內齒齒輪的節圓（Pitch circle)和變形後的可撓性外齒齒輪的嚙合位置的輪廓關係 的說明圖。如第6圖所示，剛性內齒齒輪20的節圓211 爲圓形，其直徑，如式（1)的右邊所示，是將剛性內齒齒 輪20的齒數Zc乘上該齒輪的模數m來求出。 另一方面，在可撓性外齒齒輪3 0的內側嵌入擺動產 生器40，可撓性外齒齒輪30的外齒和剛性內齒齒輪20 的內齒在嚙合位置P及嚙合位置Q這2處嚙合的狀態下 之可撓性外齒齒輪30的嚙合位置的輪廓，是用第6圖之 變形後的可撓性外齒齒輪30的嚙合位置的輪廓312來表 示。從第6圖可看出，變形後的可撓性外齒齒輪3 0的嚙 合位置的輪廓312的長軸長度，亦即嚙合位置P及Q間 的距離，可使用嚙合位置的半徑曲率R及偏心量e而依照 式（1)左邊的算式來求出。因此，可撓性外齒齒輪30的嚙 合位置的曲率半徑R滿足上述式（1)。 另外，在可撓性外齒齒輪30和剛性內齒齒輪20的嚙 合位置，由於可撓性外齒齒輪3 0是以變形的狀態，亦即 外齒呈傾斜狀態來嚙合於內齒，通常，可在第1圖所示的 可撓性外齒齒輪30的齒寬WW的中央進行兩齒輪的嚙 合。因此，變形後的可撓性外齒齒輪30的嚙合位置的輪 -14- 1359236 廓312，通常是和變形後的可撓性外齒齒輪30的齒寬WW 的中央部的輪廓一致。 接著用第7圖來說明上述式（2)。第7圖係顯示本發 明的一實施形態之擺動齒輪裝置的可撓性外齒齒輪的變形 前後的嚙合位置的輪廓的說明圖。如第7圖所示，由於可 撓性外齒齒輪30本來呈杯狀，變形前的可撓性外齒齒輪 30的節圓31 1呈圓形，其輪廓長度（圓周），如式（2)的右 邊所示，能利用可撓性外齒齒輪30的齒數Zf和該齒輪的 模數m來求出。 另一方面，變形後的可撓性外齒齒輪30的嚙合位置 的輪廓312是如第7圖所示，由於可撓性外齒齒輪30的 嚙合位置的輪廓長度在變形前後不會改變，用嚙合位置的 曲率半徑R及偏心量ε來表示之式（2)左邊（變形後的可撓 性外齒齒輪30的嚙合位置的輪廓312長度），和用齒數Zf 和模數m來表示之式（2)右邊（變形前的可撓性外齒齒輪30 的節圓311的圓周）’當然會相等。因此，可撓性外齒齒 輪30的嚙合位置的曲率半徑R滿足上述式（2)。 如以上所說明，本發明的擺動齒輪裝置10，可撓性 外齒齒輪 30的嚙合位置的曲率半徑 R滿足上述式 (1)(2)。 另外’在可撓性外齒齒輪30的內側嵌入擺動產生器 4〇’使偏心輥41的外周面和可撓性外齒齒輪30的內周面 接觸，以使可撓性外齒齒輪30的齒寬WW的中央部和剛 性內齒齒輪20在2處進行局部地嚙合的方式讓可撓性外 -15- 1359236 齒齒輪30撓曲時，在未嚙合剛性內齒齒輪的狀態下之該 可撓性外齒齒輪30的假想開口部的曲率半徑RQ及偏心量 ε 〇滿足以下式（3)、（4)。 (3) 2χ(ε 〇 + R〇) = mx{Zc + (Zc - Zf)x0.5xb/S} (4) 2x7T xR〇 + 4x ε 〇= π xmxZf 其中，R〇爲可撓性外齒齒輪30的假想開口部的曲率 半徑’ ε 〇爲假想開口部的偏心量，m爲剛性內齒齒輪2 0 及可撓性外齒齒輪30的模數，Zc爲剛性內齒齒輪20的 齒數，Zf爲可撓性外齒齒輪3〇的齒數，b爲可撓性外齒 齒輪30的齒寬WW的長度，S爲可撓性外齒齒輪30的底 面至齒寬WW中央的長度。 換言之，在可撓性外齒齒輪30的內側嵌入擺動產生 器40，使偏心輥41的外周面和可撓性外齒齒輪30的內 周面接觸，藉此以可撓性外齒齒輪30和剛性內齒齒輪20 局部地嚙合的方式讓可撓性外齒齒輪30撓曲，而使可撓 性外齒齒輪30的嚙合位置的曲率半徑R滿足上述式（1)(2) 時，假定在該變形狀態的可撓性外齒齒輪30未嚙合剛.性 內齒齒輪20的情況下的假想開口部的曲率半徑“及偏心 量ε 〇滿足以下式（3)、（4)。 用第8(a)(b)圖來說明上述式（3)及（4)。第8(a)圖係顯 示本發明的一實施形態之擺動齒輪裝置的變形後的可撓性 外齒齒輪的嚙合位置及開口部的輪廓和剛性內齒齒輪的節 -16- 1359236 圓的關係之說明圖；第8(b)圖係變形後的可撓性外齒齒輪 的側視圖。如第8 (a)圖所示，變形後的可撓性外齒齒輪 30的開口部的輪廓313的長軸長度，是比剛性內齒齒輪 20的節圓211的直徑更長。因此，變形後的可撓性外齒 齒輪30的開口部的輪廓313的曲率半徑rg變得比嚙合位 置的曲率半徑R小，偏心量ε 〇則變得比偏心量ε大。於 是，變形後的可撓性外齒齒輪30的開口部的輪廓313的 長軸長度，可根據R〇及ε〇而依式（3)左邊的算式求出。 另外，變形後的可撓性外齒齒輪30的開口部的輪廓313 的長軸長度，如式（3)右邊所示，可將變形後的可撓性外 齒齒輪30的開口部輪廓313從剛性內齒齒輪20的節圓 211超出的長度，加上剛性內齒齒輪20的節圓211的直 徑而求出。該超出長度（一側的量），是相當於以第8(b)圖 所示的b/2(第1圖所示的可撓性外齒齒輪30的齒寬WW 的一半長度）爲斜邊的直角三角形的高度。因此，變形後 的可撓性外齒齒輪30的開口部輪廓313的曲率半徑R0及 偏心量e 〇滿足式（3)。 另外，由於可撓性外齒齒輪30的嚙合位置的輪廓長 度在變形前後不會改變，用及來表示變形後的可撓 性外齒齒輪30的開口部輪廓313的長度之式（4)左邊，和 用齒數Zf及模數m來表示變形前的可撓性外齒齒輪30 的節圓311的圓周之式（4)右邊，兩者當然是相等的。因 此’變形後的可撓性外齒齒輪30的開口部輪廓313的曲 率半徑R〇及偏心量ε 〇滿足式（4)。 -17- 1359236 另外’滿足上述式（3 )(4)之變形後的可撓性外齒齒輪 3〇的開口部，如上述般，是假定在變形狀態的可撓性外 齒齒輪30未嚙合剛性內齒齒輪20的情況的假想開口部， 但由於實際上是和剛性內齒齒輪2〇嚙合，變形後的可撓 性外齒齒輪3〇的開口部的輪廓313從剛性內齒齒輪20的 節圓211超出的部分，亦即在第8(a)圖以嚙合分岐點212 的开^式來表不之2點間的圓弧部分成爲干涉狀態，在可撓 性外齒齒輪30的開口部，該部分整體會和剛性內齒齒輪 20嚙合，而使可撓性外齒齒輪30更加變形。在此，連結 嚙合分岐點212和可撓性外齒齒輪30的中心（和剛性內齒 齒輪20的中心一致）的直線、與包含變形後的可撓性外齒 齒輪30的開口部的輪廓313的長軸的直線兩者的夾角0 (參照第8(a)圖），可由式（5)來求出。 (5)0 scos·1〔 {(mxZc/2)2- R〇2+e 〇2}/(mxZcxe 〇)〕 因此，在實際的擺動齒輪裝置10的內齒和外齒的嚙 合位置，在變形後的可撓性外齒齒輪30的開口部的輪廓 313當中，角度20所對應的範圍的圓弧部分是和剛性內 齒齒輪20嚙合。 以上雖是說明本發明的實施形態，但本發明並不侷限 於上述實施形態，在申請專利範圍所記載的範圍內當然能 做各種的變更。 -18- 1359236 【圖式簡單說明] 第1圖係本發明的一實施形態之擺動齒輪裝置的分解 立體圖。 第2圖係本發明的一實施形態之擺動齒輪裝置的截面 圖。 第3圖係第2圖的A-A線截面圖。 第4圖係顯示2個偏心輥的配置狀態的示意說明圖。 φ 第5圖係本發明的一實施形態之擺動齒輪裝置的動作 說明圖。 第6圖係顯示本發明的一實施形態之擺動齒輪裝置的 剛性內齒齒輪的節圓和變形後的可撓性外齒齒輪的嚙合輪 廓的關係之說明圖。 第7圖係顯示本發明的一實施形態之擺動齒輪裝置的 可撓性外齒齒輪的變形前的節圓和變形後的嚙合輪廓的關 係之說明圖》 • 第8(a)圖係顯示本發明的一實施形態之擺動齒輪裝置 的變形後的可撓性外齒齒輪的嚙合位置及開口部輪廓和剛 . 性內齒齒輪的節圓的關係之說明圖；第8(b)圖係變形後的 可撓性外齒齒輪的側視圖。 【主要元件符號說明】 1〇 :擺動齒輪裝置 20 :剛性內齒齒輪 21 :內齒部 -19- 1359236 22:固定用螺栓孔 30:可撓性外齒齒輪 31 :外齒部 32:輸出旋轉軸安裝部 33:輸出旋轉軸安裝用螺栓孔 40 :擺動產生器 4 1 :偏心輥 4 1 a :偏心輥的圓形輪廓的中心 4 2 :偏心凸輪 43 :軸承 44 :轉輪 45:輸入旋轉軸安裝部 2 1 1 :剛性內齒齒輪的節圓 2 1 2 :嚙合分岐點 3 1 1 :變形前的可撓性外齒齒輪的節圓 312:變形後的可撓性外齒齒輪的嚙合位置的輪廓 3 1 3 :變形後的可撓性外齒齒輪的開口部輪廓 P、Q :嚙合位置 WW:可撓性外齒齒輪的齒寬 XX :擺動產生器的旋轉軸Zf: Number of teeth of the flexible externally toothed gear b: Tooth width of the flexible externally toothed gear S: Length of the bottom surface of the flexible externally toothed gear to the center of the tooth width. According to the above configuration, since the eccentric cam has a circular contour, it is possible to use a commercially available bearing without using a special bearing having an elliptical inner ring and an elastically deformable outer ring as a bearing fitted to the outer periphery of the eccentric cam. Further, since the eccentric roller is provided with a reel on the outer circumference of the bearing and the outer peripheral surface of the reel is in contact with the inner peripheral surface of the flexible externally toothed gear, it is not necessary to use the outer teeth of the flexible externally toothed gear. The elastically deformable thin outer ring bearing can suppress the ratcheting effect caused by the distortion of the elastically deformable thin outer ring. Furthermore, the oscillating generator has two eccentric rollers, and is arranged in an overlapping manner such that the centers of the circular contours of the eccentric rollers are offset from each other in the opposite directions to each other, so that it is not necessary to use an elliptical cam. The ratio of the diameter of the eccentric cam to the inner peripheral diameter of the rigid internally toothed gear can be reduced, so that the moment of inertia on the high-speed rotating side can be reduced. According to the oscillating gear device of the present invention, a commercially available bearing, i.e., -9- 1359236, can be used to prevent the ratcheting effect from occurring under an excessive load, and the moment of inertia on the high-speed rotating side can be reduced. [Embodiment] Hereinafter, a swing gear device according to an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is an exploded perspective view showing a rocking gear device according to an embodiment of the present invention. As shown in Fig. 1, the rocking gear device 10 is composed of a ring-shaped rigid internally toothed gear 20, an elastically deformable annular flexible externally toothed gear 30, and a swing generator 40. The rigid internally toothed gear 20 includes an internal tooth portion 21 formed on the inner circumferential surface, and a fixing bolt hole 22 for fixing the rigid internal gear 20 to a fixing member (not shown). The flexible externally toothed gear 30 has a cup shape and includes a tooth portion 31 formed on the outer peripheral surface of the opening side of the cup body, and an output rotary shaft mounting bolt hole for connecting to the output rotary shaft (not shown). 33. External teeth of the tooth width WW are formed in the outer tooth portion 31. The swing generator 40 is provided with two eccentric rollers 41 and an input rotary shaft mounting portion 45. Fig. 2 is a cross-sectional view showing a plane of a rocking gear device according to an embodiment of the present invention, which is a plane including a rotating shaft of a swing generator and a long axis of a flexible externally toothed gear that is deflected by a swing generator. Fig. 3 is a cross-sectional view of the Α-Α line of Fig. 2. As shown in FIGS. 2 and 3, in the swing gear device 10, the flexible externally toothed gear 30 is disposed inside the rigid internally toothed gear 20, and the swinging generator 40 is fitted in the flexible externally toothed gear 30 to make it flexible. The external external gear 30 is deflected, whereby the internal teeth formed in the internal teeth-10-I359236 of the rigid internally toothed gear 20 and the external teeth formed in the external toothing 31 of the flexible externally toothed gear 30 are At two positions opposite to each other across the center of the rigid internally toothed gear 20, that is, the meshing positions P and Q are engaged. The rigid internally toothed gear 20 is formed of a rigid body. The flexible externally toothed gear 30 may be made of a flexible material as a whole, but may be formed of a flexible material at least in addition to the annular output rotary shaft mounting portion 32 provided on the cup-shaped bottom surface, and may be formed of a flexible material. A thin, elastically deformed construction. The output rotary shaft mounting portion 32 is formed thicker than the other portions, and is provided with an output rotary shaft mounting bolt hole 33. In addition, the external tooth portion 31 is also formed to be elastically deformable. The swing generator 40 has two circular contoured eccentric rollers 41. The eccentric roller 41 includes an eccentric cam 42 that is circularly contoured around the rotation axis XX of the swing generator with a predetermined eccentricity, a bearing 43 that is fitted to the outer circumference of the eccentric cam 42, and a runner that is disposed on the outer circumference of the bearing 43. 44. The eccentric cam 42 is fixed to the input rotary shaft mounting portion 45. Fig. 4 is a schematic explanatory view showing an arrangement state of two eccentric rollers. As shown in Fig. 4, the two eccentric rollers 41 are arranged in an overlapping manner such that the centers 41a of the circular contours of the eccentric rollers are deviated from the rotational axis XX of the oscillating generator 40 by a predetermined amount (?) in mutually opposite directions. Since the swing generator 40 has such a shape, when the swing generator 4 is fitted inside the flexible externally toothed gear 30, the outer peripheral surface of the eccentric roller 41 contacts the inside of the external tooth portion 31 of the flexible externally toothed gear 30. The flexible externally toothed gear 30 is deflected by the circumferential surface, and the external teeth of the flexible externally toothed gear 30 and the internal teeth of the rigid internally toothed gear 20 are opposed to each other across the center of the rigid internally toothed gear 20 Engage (see Figure 3). -11 - 1359236 As described above, the swing gear device 10 of the present embodiment is different from the wave generator of the conventional wave gear device (having an elliptical cam and a bearing having an elastically deformable outer ring), The oscillating generator 40 is provided as an eccentric roller 41 having two circular contours, and is disposed so as to overlap such that the center 41a of the circular contour of each eccentric roller 41 is offset from the swing generator 40 by the aforementioned amount in the opposite directions. Rotate the axis XX. Therefore, in the oscillating gear device 10 of the present embodiment, the eccentric cam 42 used in the eccentric roller 41 has a circular contour, and it is not necessary to use a special bearing having an elliptical inner ring and an elastically deformable outer ring, so that it is fitted to the eccentricity. A commercially available bearing can be used for the bearing 43 on the outer circumference of the cam 42. Further, since it is not necessary to use a bearing having a thin outer ring which is elastically deformable on the back surface of the external teeth of the flexible externally toothed gear, by providing the runner 44 outside the bearing 43, it is possible to suppress the thin outer ring which is caused by the elastic deformation. The phenomenon of ratcheting caused by the deflection. Further, since the ratio of the diameter of the eccentric cam 42 to the diameter of the rigid internally toothed gear 20 is lowered, the moment of inertia on the high speed rotating side can be reduced. Next, the operation of the swing gear device 10 will be described using FIG. Fig. 5 is an explanatory view showing the operation of the swing gear device according to the embodiment of the present invention. In the swing gear device 10 of the present embodiment, the input rotary shaft is attached to the input rotary shaft mounting portion 45 of the swing generator 40, and when the motor is driven by a motor or the like, the swing generator 40 starts to rotate. As shown in Fig. 5, before the rotation, the internal teeth indicated by the oblique lines of the rigid internally toothed gear 20 and the external teeth indicated by the blackening of the flexible externally toothed gear 30 mesh with each other. If the swing generator 40 is rotated by 90 degrees, the meshing position is moved by 90 degrees in the circumferential direction of -12 - 1359236. In the swing gear device 1 of the present embodiment, the difference between the number of internal teeth of the rigid internally toothed gear 20 and the number of external teeth of the flexible externally toothed gear 3 is 2 teeth, and if the swing generator 40 is in the circumferential direction at the meshing position In the moving state, the rotation is 3 60 degrees, and in order to return the meshing position to the internal teeth indicated by the oblique line of the rigid internal gear 20, the flexible externally toothed gear 30 must rotate the number of external teeth plus the amount of 2 teeth. That is, when the swing generator 40 is rotated 360 degrees, the object engaged with the internal teeth indicated by the oblique lines is the external teeth separated from the external teeth shown by the black teeth. As a result, the flexible externally toothed gear 30 is relatively rotated in a direction opposite to the rotational direction of the swing generator 40 by the component of the two teeth. In the rocking gear device 10 of the present embodiment, since the rigid internally toothed gear 20 is fixed so as not to be relatively rotatable, the flexible externally toothed gear 30 can be outputted in response to the difference in the number of teeth of the internal and external teeth. Rotate. Here, the swing generator 40 is fitted inside the flexible externally toothed gear 30, and the outer peripheral surface of the eccentric roller 41 is brought into contact with the inner peripheral surface of the flexible externally toothed gear 30, and the flexible externally toothed gear 30 and When the rigid externally toothed gear 20 is partially meshed at two places, when the flexible externally toothed gear 30 is deflected, the radius of curvature R of the meshing position of the flexible externally toothed gear 30 satisfies the following formula (1) (2). (1) 2x( e +R) = mxZc (2) 2χ π xR + 4x ε = π xmxZf where R is the curvature of the meshing position of the flexible externally toothed gear 30, half--13 - 1359236, and ε is the eccentric roller The eccentricity of 41 is m, the modulus of the rigid internally toothed gear 20 and the flexible externally toothed gear 30, Zc is the number of teeth of the rigid internally toothed gear 20, and Zf is the number of teeth of the flexible externally toothed gear 30. The above formula (1) will be described using Fig. 6. Fig. 6 is an explanatory view showing a contour relationship between a pitch circle of a rigid internally toothed gear of the rocking gear device according to the embodiment of the present invention and a meshing position of the deformed flexible externally toothed gear. As shown in Fig. 6, the pitch circle 211 of the rigid internally toothed gear 20 is circular, and its diameter, as shown on the right side of the formula (1), is the number of teeth Zc of the rigid internally toothed gear 20 multiplied by the modulus of the gear. m to find. On the other hand, the swing generator 40 is fitted inside the flexible externally toothed gear 30, and the external teeth of the flexible externally toothed gear 30 and the internal teeth of the rigid internally toothed gear 20 are at the meshing position P and the meshing position Q. The contour of the meshing position of the flexible externally toothed gear 30 in the engaged state is represented by the contour 312 of the meshing position of the flexible externally toothed gear 30 after the modification of Fig. 6. As can be seen from Fig. 6, the length of the long axis of the contour 312 of the meshing position of the deformed flexible externally toothed gear 30, that is, the distance between the engaging positions P and Q, can be the radius curvature R of the meshing position and The eccentricity e is obtained by the equation on the left side of the equation (1). Therefore, the radius of curvature R of the engagement position of the flexible externally toothed gear 30 satisfies the above formula (1). Further, in the meshing position of the flexible externally toothed gear 30 and the rigid internally toothed gear 20, since the flexible externally toothed gear 30 is in a deformed state, that is, the external teeth are inclined to engage the internal teeth, usually, The meshing of the two gears can be performed at the center of the tooth width WW of the flexible externally toothed gear 30 shown in Fig. 1 . Therefore, the wheel-14-1359236 profile 312 of the meshing position of the deformed flexible externally toothed gear 30 generally coincides with the contour of the central portion of the tooth width WW of the deformed flexible externally toothed gear 30. Next, the above formula (2) will be described using Fig. 7. Fig. 7 is an explanatory view showing the outline of the meshing position before and after the deformation of the flexible externally toothed gear of the rocking gear device according to the embodiment of the present invention. As shown in Fig. 7, since the flexible externally toothed gear 30 is originally cup-shaped, the pitch circle 31 1 of the flexible externally toothed gear 30 before deformation is circular, and its contour length (circumference) is as in the formula (2). The right side of the magnetic external gear 30 can be obtained by using the number of teeth Zf of the flexible externally toothed gear 30 and the modulus m of the gear. On the other hand, the contour 312 of the meshing position of the deformed flexible externally toothed gear 30 is as shown in Fig. 7, since the contour length of the meshing position of the flexible externally toothed gear 30 does not change before and after the deformation, The radius of curvature R and the eccentric amount ε of the meshing position indicate the left side of the equation (2) (the length of the contour 312 of the meshing position of the deformed flexible externally toothed gear 30), and the expression of the number of teeth Zf and the modulus m. (2) The right side (the circumference of the pitch circle 311 of the flexible externally toothed gear 30 before deformation) is of course equal. Therefore, the radius of curvature R of the meshing position of the flexible external tooth gear 30 satisfies the above formula (2). As described above, in the swing gear device 10 of the present invention, the radius of curvature R of the meshing position of the flexible externally toothed gear 30 satisfies the above formula (1) (2). Further, 'the oscillating generator 4' is fitted inside the flexible externally toothed gear 30 so that the outer peripheral surface of the eccentric roller 41 and the inner peripheral surface of the flexible externally toothed gear 30 are brought into contact with each other to make the flexible externally toothed gear 30 When the central portion of the tooth width WW and the rigid internal tooth gear 20 are partially meshed at two places, the flexible outer-15-1359236 tooth gear 30 is flexed, and the rigid internal tooth gear is not engaged. The radius of curvature RQ and the eccentricity ε 〇 of the virtual opening of the flexible externally toothed gear 30 satisfy the following formulas (3) and (4). (3) 2χ(ε 〇+ R〇) = mx{Zc + (Zc - Zf)x0.5xb/S} (4) 2x7T xR〇+ 4x ε 〇= π xmxZf where R〇 is a flexible external tooth The radius of curvature 'ε 〇 of the virtual opening of the gear 30 is the eccentric amount of the virtual opening, m is the modulus of the rigid internally toothed gear 20 and the flexible externally toothed gear 30, and Zc is the number of teeth of the rigid internally toothed gear 20, Zf is the number of teeth of the flexible externally toothed gear 3〇, b is the length of the tooth width WW of the flexible externally toothed gear 30, and S is the length from the bottom surface of the flexible externally toothed gear 30 to the center of the tooth width WW. In other words, the swing generator 40 is fitted inside the flexible externally toothed gear 30 so that the outer peripheral surface of the eccentric roller 41 and the inner peripheral surface of the flexible externally toothed gear 30 are in contact with each other, whereby the flexible externally toothed gear 30 and The rigid externally toothed gear 20 is partially meshed in such a manner that the flexible externally toothed gear 30 is flexed, and when the radius of curvature R of the meshing position of the flexible externally toothed gear 30 satisfies the above formula (1)(2), it is assumed that The radius of curvature "and the eccentric amount ε 〇 of the virtual opening portion when the flexible externally toothed gear 30 in the deformed state is not engaged with the rigid externally toothed gear 20 satisfy the following formulas (3) and (4). (a) (b) The above formulas (3) and (4) are shown. Fig. 8(a) is a view showing the meshing position of the deformed flexible externally toothed gear of the rocking gear device according to the embodiment of the present invention. And an explanatory view of the relationship between the contour of the opening and the section of the rigid internally toothed gear - 16 - 1359236; the 8th (b) is a side view of the deformed flexible externally toothed gear. Figure 8 (a) As shown, the long axis length of the contour 313 of the opening portion of the deformed flexible externally toothed gear 30 is smaller than the pitch circle 211 of the rigid internally toothed gear 20. Therefore, the radius of curvature rg of the contour 313 of the opening portion of the deformed flexible externally toothed gear 30 becomes smaller than the radius of curvature R of the meshing position, and the eccentric amount ε 〇 becomes larger than the eccentric amount ε. Therefore, the length of the major axis of the contour 313 of the opening of the deformed flexible externally toothed gear 30 can be obtained by the equation on the left side of the equation (3) based on R 〇 and ε 。. The long axis length of the outline 313 of the opening portion of the externally toothed gear 30, as shown on the right side of the formula (3), can cut the opening profile 313 of the deformed flexible externally toothed gear 30 from the pitch circle of the rigid internally toothed gear 20. The excess length of 211 is obtained by adding the diameter of the pitch circle 211 of the rigid internally toothed gear 20. The excess length (the amount of one side) is equivalent to b/2 shown in Fig. 8(b). The half length of the tooth width WW of the flexible externally toothed gear 30 shown in Fig. 1 is the height of the right-angled triangle of the oblique side. Therefore, the radius of curvature R0 of the opening profile 313 of the deformed flexible externally toothed gear 30 is shown. And the eccentric amount e 〇 satisfies the formula (3). In addition, since the contour length of the meshing position of the flexible externally toothed gear 30 is The shape does not change before and after, and the length of the opening profile 313 of the deformed flexible externally toothed gear 30 is indicated by the left side of the equation (4), and the number of teeth Zf and the modulus m are used to indicate the flexibility before deformation. The circumference of the pitch circle 311 of the externally toothed gear 30 is the right side of the formula (4), and the two are of course equal. Therefore, the radius of curvature R 〇 and the eccentricity ε of the opening profile 313 of the deformed flexible externally toothed gear 30 are ε. 〇 〇 ( ( ( ( -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 -17 The virtual external gear 30 does not mesh with the imaginary opening of the rigid internal gear 20, but actually meshes with the rigid internal gear 2〇, and the contour 313 of the opening of the deformed flexible externally toothed gear 3〇 The portion exceeding the pitch circle 211 of the rigid internally toothed gear 20, that is, the arc portion between the two points indicated by the opening pattern of the meshing point 212 in the eighth (a) diagram becomes an interference state, and is flexible. The opening of the external external gear 30, which is integrally engaged with the rigid internal gear 20 to provide flexibility The external gear 30 is more deformed. Here, the straight line connecting the meshing branch point 212 and the center of the flexible externally toothed gear 30 (which coincides with the center of the rigid internally toothed gear 20) and the contour 313 of the opening including the deformed flexible externally toothed gear 30 are provided. The angle 0 between the straight lines of the long axis (see Fig. 8(a)) can be obtained by the equation (5). (5) 0 scos·1 [ {(mxZc/2)2- R〇2+e 〇2}/(mxZcxe 〇)] Therefore, in the meshing position of the internal teeth and the external teeth of the actual swing gear device 10, Among the contours 313 of the opening portion of the deformed flexible externally toothed gear 30, the arc portion of the range corresponding to the angle 20 is meshed with the rigid internally toothed gear 20. The embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. -18- 1359236 [Brief Description of the Drawings] Fig. 1 is an exploded perspective view showing a rocking gear device according to an embodiment of the present invention. Fig. 2 is a cross-sectional view showing a rocking gear device according to an embodiment of the present invention. Fig. 3 is a cross-sectional view taken along line A-A of Fig. 2. Fig. 4 is a schematic explanatory view showing an arrangement state of two eccentric rollers. Fig. 5 is a view showing the operation of the rocking gear device according to the embodiment of the present invention. Fig. 6 is an explanatory view showing the relationship between the pitch circle of the rigid internally toothed gear of the rocking gear device according to the embodiment of the present invention and the meshing contour of the deformed flexible externally toothed gear. Fig. 7 is an explanatory view showing the relationship between the pitch circle before deformation and the meshing contour after deformation of the flexible externally toothed gear of the rocking gear device according to the embodiment of the present invention. • Fig. 8(a) shows the present Description of the relationship between the meshing position of the flexible externally toothed gear and the pitch contour of the rigid internal gear and the pitch of the rigid internal gear in the swing gear device according to the embodiment of the present invention; FIG. 8(b) Side view of the flexible external gear. [Description of main component symbols] 1〇: Swing gear device 20: Rigid internal gear 21: Internal toothing -19- 1359236 22: Fixing bolt hole 30: Flexible external gear 31: External toothing 32: Output rotation Shaft mounting portion 33: Output rotary shaft mounting bolt hole 40: Swing generator 4 1 : Eccentric roller 4 1 a : Center of circular contour of eccentric roller 4 2 : Eccentric cam 43 : Bearing 44 : Rotor 45: Input rotation Shaft mounting portion 2 1 1 : pitch circle 2 1 2 of the rigid internally toothed gear: meshing point 3 1 1 : pitch circle 312 of the flexible externally toothed gear before deformation: meshing of the deformed flexible externally toothed gear Position profile 3 1 3 : Opening profile of the deformed flexible externally toothed gear P, Q: Engagement position WW: Tooth width of the flexible externally toothed gear XX: Rotation axis of the oscillating generator