200905104 九、發明說明 【發明所屬之技術領域】 本發明是偏心擺動減速裝置。 【先前技術】 具備以下構件的偏心擺動減速裝置（譬如，請參考專 利文獻1)已廣爲大眾所熟知：太陽旋轉體；和偏心體軸驅 動體，該偏心體軸驅動體是藉由上述太陽旋轉體而旋轉； 和偏心軸，該偏心軸是與該偏心體軸驅動體一體地旋轉； 和擺動體，該擺動體是藉由上述偏心軸而攏動旋轉；及托 架體，該托架體是與該擺動體的自轉部分同步。 此外，相同的申請人已針對該專利文獻1之構造提出 一種改良的構造。 第5圖、第6圖中顯示上述經改良的偏心擺動減速裝置 〇 該偏心擺動減速裝置1 2，是在輸入軸1 4形成有太陽齒 輪（太陽旋轉體）16。太陽齒輪16同時與複數個（在本例中 爲3個）傳動齒輪（偏心體軸驅動體）1 8嚙合。200905104 IX. Description of the Invention [Technical Field of the Invention] The present invention is an eccentric oscillating reduction device. [Prior Art] An eccentric oscillating reduction device having the following components (for example, refer to Patent Document 1) is well known to the public: a sun rotating body; and an eccentric body shaft driving body by which the sun is Rotating body and rotating; and an eccentric shaft that rotates integrally with the eccentric body drive body; and an oscillating body that is rotated by the eccentric shaft; and a bracket body, the bracket The body is synchronized with the rotation portion of the oscillating body. Further, the same applicant has proposed an improved configuration for the configuration of Patent Document 1. In the fifth and sixth figures, the modified eccentric oscillating reduction gear unit 〇 is shown. The eccentric oscillating reduction gear unit 12 has a sun gear (sun rotor) 16 formed on the input shaft 14. The sun gear 16 is simultaneously meshed with a plurality of (in this example, three) transmission gears (eccentric body shaft drive bodies) 18.
各傳動齒輪1 8 ’是分別組裝入所設置的複數支（在本 例中爲3支）偏心體軸20。在各偏心體軸20，偏心體22A、 22B是設置於180°的相位。當輸入軸14旋轉時，將由前述 傳動齒輪1 8來驅動3支偏心體軸2 0，而使位於該3支偏心體 軸20之軸方向上相同位置的3個偏心體群22A、或22B分別 在相同的相位朝同一方向旋轉。2個外齒齒輪（擺動體）24A 200905104 、24B ’是分別嵌合於該偏心體22A、22B的外周。因此 ，該2個外齒齒輪24 A、24B，是對應於各偏心體22 A、22 B 的動作而以1 80°的相位差形成偏心旋轉。 偏心體22A、22B與外齒齒輪24A、24B之間的嵌合， 是隔著滾珠或滾柱（在本例中爲滾柱）2 6 A、2 6 B而轉動嵌 合。外齒齒輪24A、24B是內接嵌合於內齒齒輪28。 內齒齒輪28與殼體30形成一體化，其內齒是由滾柱狀 的銷28P所構成。外齒齒輪24A、24B與內齒齒輪28，是 設定成少數的齒數差（譬如1〜6)。 在外齒齒輪24 A、24B的軸方向兩側，配置有第1、第 2托架（托架體）32、34。2個外齒齒輪24A、24B，是藉由配 置於該第1、第2托架32、34與該2個外齒齒輪24A、24B之 間的間隔件25來限制其軸方向的移動。第1、第2托架32、 34是透過螺栓40及托架銷42而相互連結，其整體是隔著圓 錐滾柱軸承36、3 8而可旋轉地由殼體30所支承。 該構造的偏心擺動減速裝置12，可藉由透過傳動齒輪 18來減速輸入軸14的旋轉後傳達至各偏心體軸20，而使各 偏心體軸2 0的偏心體2 2 A、2 2 B分別在相同相位旋轉，進 而促使外齒齒輪24A、24B擺動。如此一來，由於產生外 齒齒輪24A、24B與內齒齒輪28間的嚙合位置依序偏移， 故可伴隨著偏心體軸20的旋轉而在該外齒齒輪24A、24B 與內齒齒輪2 8間引發相當於齒數差的相對位移。當殼體 3〇(內齒齒輪28)被固定時，上述的相對位移可從一對第1 、第2托架32、34側抽出，當第1、第2托架32、34的自轉 200905104 受到拘束時’上述相對位移可被當成殼體30側的旋轉（框 架旋轉）而抽出。 [專利文獻1]日本特開2004-138094號公報 【發明內容】 [發明主題] [發明欲解決之課題] 但是’在上述構造的偏心擺動減速裝置中，譬如是著 眼於軸方向的縮短’但在如同後述實施形態之構造般將傳 動齒輪1 8配置於外齒齒輪2 4 A、2 4 B間的場合中，卻具有 該傳動齒輪1 8的外周緣與間隔件2 5的內周緣產生千涉，致 使傳動齒輪1 8的尺寸無法增大的問題。因此，當欲在第一 段減速部（太陽齒輪16與傳動齒輪18)中獲得一定程度以上 之減速比時’如同已説明的第5圖構造，必須使傳動齒輪 1 8的配置位置形成於不會與間隔件25產生干涉的位置（圖 示例中外齒齒輪24A的軸方向外側），而具有導致減速裝 置整體的軸方向長度變長的問題。 本發明正是爲了解決上述習知問題而硏發的發明，本 發明的課題爲：不拘泥於間隔件的存在，可藉由將傳動齒 輪配置在與間隔件於軸方向上相同的位置而縮短裝置整體 的軸方向長度，並可藉由合理地消除該間隔件與傳動齒輪 之間的千涉，並無損於間隔件原本的定位功能，且可將相 當巨大的傳動齒輪在軸方向上配置在與間隔件相同的位置 ，而取得第一段減速部的大減速比。 200905104 [解決課題之手段] 本發明是具有以下構件的的偏心擺動減速裝置：太陽 旋轉體；和偏心體軸驅動體，該偏心體軸驅動體是藉由該 太陽旋轉體而旋轉；和偏心體軸’該偏心體軸是與該偏心 體軸驅動體一體地旋轉；和擺動體，該擺動體是藉由該偏 心體軸而擺動旋轉；及托架體，該托架體與該擺動體的自 轉部分同步’本發明可藉由以下的構造來解決前述課題·· 具備間隔件’該間隔件配置在與前述偏心體軸驅動體於軸 方向上相同的位置，並可限制擺動體之軸方向的移動，前 述間隔件形成：該裝置半徑方向的最內部成爲包含前述偏 心體軸驅動體之裝置半徑方向最外部的圓周內側，並形成 可停止對前述托架體旋轉的構造。 根據本發明’間隔件是形成：其半徑方向最內部成爲 包含偏心體軸驅動體之最外部的圓周內側。如此一來，由 於是將偏心體軸擺動體配置在與間隔件於軸方向上相同的 位置（可縮短裝置之軸方向長度的狀態下），並以特定的部 分充分地確保該間隔件之半徑方向的寬度，故可將間隔件 與偏心體軸驅動體間干涉部分之半徑方向的寬度設定成較 小。因此，可收容上述的大型傳動齒輪，並獲得第一段減 速部（也就是指：由太陽旋轉體與偏心體軸驅動體所構成 的減速部）的大減速比。 [發明的效果] -8 - 200905104 根據本發明可獲得：既可使第一段維持高減速比，且 軸方向長度更短的偏心擺動減速裝置。 【實施方式】 [實施型態] 以下，根據圖面來詳細地說明本發明之實施形態的其 中一例。 第1圖’是顯示本發明實施形態中偏心擺動減速裝置 之其中一例的剖面圖，第2圖爲沿著第1圖中箭號π - ϋ線 的剖面圖。而第1圖是相當於沿著第2圖中箭號I - I線的 剖面圖。 該偏心擺動減速裝置112具備·太陽齒輪（太陽旋轉體 )1 1 6，該太陽齒輪（太陽旋轉體）1 1 6設於輸入軸1 1 4 ;和傳 動齒輪（偏心體軸驅動體）1 1 8，該傳動齒輪（偏心體軸驅動 體）1 1 8是藉由該太陽齒輪1 1 6而旋轉；和偏心體軸1 2 0，該 偏心體軸1 2 0是與該傳動齒輪1 1 8 —體地旋轉；和外齒齒輪 (擺動體）124Α、124Β，該外齒齒輪（擺動體）124Α、124Β 是利用該偏心體軸120而擺動旋轉；及第1、第2托架（托架 體）132、134，該第1、第2托架（托架體）132、134與該外 齒齒輪124Α、124Β的自轉部分同步。 以下，進行更詳細的說明。 輸入軸114，可與圖面中未顯示之馬達的輸出軸連結 。在輸入軸114的前端一體地形成有太陽齒輪116。太陽齒 輪1 16同時與複數個（在本例中爲2個）傳動齒輪1 1 8嚙合。 200905104 各傳動齒輪π 8是分別組裝入複數設置（在本例中爲2 支）的偏心體軸1 2 0，2支偏心體軸1 2 0可同時且朝同方向驅 動。在各偏心體軸120，以180°的相位設有偏心體122Α、 12 2Β，且該偏心體122Α、122Β是分別並列於軸方向。此 外，在各軸之軸方向的相同位置，各軸的偏心體1 2 2 Α群 、及偏心體1 22B群是分別以相同的相位而組裝成可朝相 同方向旋轉。 外齒齒輪124A是分別嵌合於2個偏心體122A的外周 ，而外齒齒輪124B則分別嵌合於2個偏心體122B的外周 。偏心體122A、122B與外齒齒輪124A、124B之間的嵌合 是隔著滾柱126A、126B而轉動嵌合，如此一來，外齒齒 輪124A、124B，是以180度的相位差而分別內接嚙合於內 齒齒輪128。而外齒齒輪124A、124B在軸方向並列配置2 個（12 4A、124B)的作法，是爲了確保傳達容量。各外齒齒 輪124A、124 B之軸方向的位置，是由斜角滾珠軸承136、 138及間隔件125所限制。針對間隔件125的構造，將於稍 後詳述。 內齒齒輪128是與殼體130形成一體化，其內齒是由滾 柱狀的銷128P所構成。外齒齒輪124A、124B與內齒齒輪 128，是設定成少量的齒數差（譬如，1〜6左右的齒數差） 。而在該例中，相當於內齒齒輪1 2 8之內齒的銷1 2 8 P，雖 然是採用2個一組的間歇設置方式（每設置2個便空出2個空 位之意）組裝，就嚙合所產生的動作而言，可獲得與不具 上述「間歇設置」時（譬如，第6圖所示的例子）完全相同 -10- 200905104 的動作。前述「少量的齒數差」是指··在不採用上述間歇 設置的狀態下之外齒與內齒的齒數差。 在外齒齒輪124A、124B的軸方向兩側，配置著第1、 第2托架132、134。第丨、第2托架132、134，是隔著從螺 栓140及第2托架134側形成—體突出的托架銷i34A而互相 連結，其整體是隔著前述斜角滾珠軸承1 3 6、1 3 8而可旋轉 地由殼體130所支承。 前述偏心體軸120’是隔著滾針150、152而由第1、第 2托架1 3 2、1 3 4所支承。滾針丨5 〇、1 5 2是藉由：分別將偏 心體軸120當作內輪使用，將第}、第2托架丨32、！ 34作爲 外輪使用’而構成「滾針軸承（needle bearing)」。但由於 滾針1 5 0、1 5 2無法單獨授受推力方向的反作用力，因此在 該實施形態中’爲了偏心體軸1 2 0之軸方向的定位而採用 以下的構造。 亦即’在偏心體軸1 2 0形成有階梯部1 7 〇、！ 7 2。除此 之外，利用該階梯部1 70、1 72，而在該階梯部丨70、i 72與 第1、第2托架1 3 2、1 3 4之間配置有用來限制偏心體軸1 2 〇 之軸方向移動的墊片174、176。 墊片174、176’是藉由抵接於第1'第2托架132、134 的方式而透過階梯部1 7 0、1 7 2來執行偏心體軸1 2 〇之軸方 向的定位’並藉由將滾柱1 26A、傳動齒輪丨丨8、另—個滾 柱1 2 6 B挾持於其間的方式，執行1 2 6 A、1 1 8、1 2 6 B之軸 方向的定位。而墊片174、176是配置成：可對第1、第2托 架132、134 ;及階梯部170、172的其中任—個相對旋轉。 -11 - 200905104 而圖面中的圖號1 6 7、1 6 9，是用來限制滾針1 5 0、1 5 2 之軸方向移動的滾針保持具。此外，圖號1 42是用來連結 第1、第2托架132、134與配合構件（被驅動機械）的螺栓孔 ，：180爲治具安裝部，該治具安裝部是用來安裝治具（圖示 省略），而該治具是在加工偏心體軸1 2 0時，用來停止其旋 轉的。 在此’針對間隔件1 2 5的構造進行說明。而外齒齒輪 124Α的外齒中，被間隔件125所遮蔽的部分應該以虛線的 方式來表示，但爲了方便則以實線來繪製。 間隔件1 2 5是形成：其裝置半徑方向的最內部（圖示例 中Ρ101〜Ρ1 04的4個位置），成爲包含傳動齒輪1 18之裝置 半徑方向的最外部（圖示例中S101、S102的2個位置）之圓 周R 1 0 1內側的形狀。間隔件1 2 5整體呈環狀，且其內周側 爲了避免與傳動齒輪1 1 8之間的干涉，而具有可在與該傳 動齒輪1 18間確保間隙5的第1凹部125Α(2個位置）。此外 ，該間隔件125具有：呈現沿著托架銷134Α外周局部之形 狀的第2凹部125Β(4個位置）。藉由其中的第2凹部1ΜΒ與 托架銷1 3 4 Α之間的卡合，使間隔件1 2 5與第1、第2托架 132、134在圓周方向上形成一體化，如此一來，可構成使 間隔件125對第1、第2托架132、134停止旋轉的構造。 接著，說明該偏心擺動減速裝置1 1 2的作用。 當輸入軸1 14旋轉時，透過與該輸入軸1 14嚙合的傳動 齒輪1 1 8同時使2支偏心體軸1 20減速旋轉。如此一來，一 體安裝於各偏心體軸120的偏心體122A群及122B群則以 -12- 200905104 相同相位旋轉，而外齒齒輪12 4 A、12 4 B則是在內接於內 齒齒輪128的狀態下各自擺動旋轉。內齒齒輪128與殼體 1 3 0形成一體化’由於呈現固定狀態’因此當偏心體軸1 2 0 旋轉時是透過偏心體122A、122B而使外齒齒輪124A、 124B擺動旋轉，並使該外齒齒輪124A、124B與內齒齒輪 1 2 8的嚙合位置產生依序偏移的現象。 此時，由於外齒齒輪124A、124B的齒數略少於內齒 齒輪128，故對呈固定狀態的內齒齒輪128形成相當於齒數 差的相位偏移（自轉）。因此’偏心體軸1 2 0是以相當於該 自轉部分的速度而在輸入軸的周圍形成公轉’支承著 該偏心體軸120的第1、第2托架132、134則是以相當於該 公轉速度的速度來旋轉。由於第1、第2托架132、134是透 過螺栓140及托架銷134A而連結，故第1、第2托架132、 134形成一體（形成一個大型塊狀體）且緩慢地旋轉，並驅 動透過螺栓孔1 42所連結之圖面中未顯示的配合機械（被驅 動機械）。 再者，如同該實施形態，當殼體1 3 0 (內齒齒輪1 2 8 )被 固定時，外齒齒輪1 2 4 A、1 2 4 B與內齒齒輪1 2 8之間的相對 位移可從第1、第2托架132、134側取出，當形成第1、第2 托架1 3 2、1 3 4的自轉受到拘束的構造時，可透過該第1、 第2托架1 3 2、1 3 4的自轉拘束’將該相對位移作爲殼體1 3 〇 側的旋轉（框架旋轉）而取出。 在此，該實施形態的偏心擺動減速裝置1 1 2，於外齒 齒輪124A、124B的兩側具有第1、第2托架132、134，並 -13- 200905104 藉由該第1'第2托架132、134從兩端支承2支偏心體軸120 ’可在支持剛性高且外齒齒輪i 2 4 A、1 2 4 B穩定的狀態下 擺動旋轉。 由於2個外齒齒輪124A、124B，是被一對第}、第2托 架1 3 2、1 3 4所挾持’且間隔件]2 5配置於其軸方向的中央 ’因此無須特別設置額外的扣環等定位手段，便可限制軸 方向的移動。 在此’間隔件1 2 5 ’由於其裝置半徑方向的最內部 P101〜P1 04是形成包含傳動齒輪118之裝置半徑方向最外 部S101、S102的圓周R101的內側，在該最內部pi〇i〜 P 1 04的附近是形成：可於半徑方向上確保極大的厚度 w 1 0 1，並可對位於該間隔件1 2 5兩側的外齒齒輪1 24 A、 124B執行良好的地位。因此，在傳動齒輪118之最外部 S 101、Sl〇2的外側是形成：可充分地確保極薄寬度W1 02 ，只需如此可確保傳動齒輪1 1 8的大尺寸。因此，可將減 速比設成：第一段減速部（太陽齒輪1 16及傳動齒輪1 18)可 確保的高減速比。因此，可沒有阻礙地將傳動齒輪118與 間隔件1 2 5配置在軸方向的相同位置，並縮短軸方向長度 〇 由於可藉由托架銷1 3 4 A與第2之凹部1 2 5 B ’使間隔件 1 2 5對第1、第2托架1 3 2、1 3 4停止旋轉（一體地作動）’故 可於該間隔件1 2 5與傳動齒輪1 1 8之間形成：持續維持確保 著特定間隙6的狀態。因此，在運轉中間隔件1 2 5不會與 傳動齒輪1 1 8接觸。 -14- 200905104 而在該實施形態中，如以上所述，隨著可確保第一段 減速部（太陽齒輪1 1 6與傳動齒輪11 8 )的大減速比，並藉由 將傳動齒輪1 1 8配置於2個外齒齒輪1 2 4 A、1 2 4 B之間而獲 得「可縮短軸方向的好處」，但在本發明中，就如何活用 上述好處的這一點並無特殊的限制。亦即，該好處如同文 字所描述，除了有助於實現縮短裝置的軸方向之外，如該 實施形態所示，該部分亦可用於治具安裝部1 8 0的形成， 該治具安裝部1 8 0是用來安裝加工偏心體軸1 2 0時防止其旋 轉的治具（圖示省略）。如此一來，由於能以一次來夾取偏 心體軸120與偏心體122A、122B而執行高精度的加工，而 形成可縮短加工時間、降低加工成本及提高加工精度。不 僅如此，譬如當軸方向的長度允許與現有者相同時，上述 的好處亦可轉朝增加傳達容量的方向活用。 接下來’採用第3圖、第4圖來說明本發明的其他實施 形態。 在該偏心擺動減速裝置2 1 2中，間隔件225是由在圓周 方向上非連續的2個構件22 5 - 1、225-2所構成。各構件 22 5-1、225-2’其各裝置半徑方向的最內部S201、S2〇2是 配置成：包含傳動齒輪218之裝置半徑方向最外部S2〇i、 S202的圓周R201的內側。而以上所述「圓周方向上非連 續」的用語，其含意爲「是藉由2個以上的構件（並非單一 構件）在圓周方向上所構成，而不是在軸方向上」。 各構件225-1、225-2具有第2之凹部225-1B、225-2B ，該第2之凹部225 - 1 B、225-2B各自具有沿著托架銷234 -15- 200905104 外周之局部的形狀，藉由托架銷23 4A及上述第2之凹部 225B-1B、225-2B，可停止間隔件 225-1、255-2對第 1、第 2托架232、234的旋轉° 根據該實施形態，由於在傳動齒輪2 1 8之最外部S 2 0 1 、S2 02的裝置半徑方向外側完全不存在間隔件，因此關於 傳動齒輪2 1 8的設計，可確保最大限度的設計裕度（彈性） 。針對上述的其他構造，由於基本上與先前所說明的實施 形態相同，因此在圖中針對相同或者相當的部位，標示後 2碼相同的圖號並省略其說明。 就間隔件的形狀而言’上述實施形態中所示的形狀僅 是其中一種範例罷了’可考慮採用各式各樣的形狀。舉例 來說，除了可以採用第2實施形態所示之2個以上的構件來 作爲間隔件之外，也不排除倂用環狀的間隔件。 此外，所配置之間隔件的數量也沒有特殊的限制。 [產業上的利用性] 本發明可在傳統上導入該種偏心擺動減速裝置的領域 中’作爲既可實現高減速比’又可更進一步縮短軸方向長 度的改良品使用。 【圖式簡單說明】 第1圖：爲本發明實施形態之其中一例的偏心擺動減 速裝置的縱剖面圖。 第2圖：爲沿著上述減速裝置之箭號π _ π線的剖面圖 -16- 200905104 第3圖：爲本發明另一種實施形態之範例的偏心擺動 減速裝置的剖面圖。 第4圖：爲沿著第3圖之箭號IV-IV線的剖面圖。 第5圖：爲顯示習知偏心擺動減速裝置之其中一例的 剖面圖。 第6圖：爲沿著第5圖之箭號VI-VI線的剖面圖。 【主要元件符號說明】 1 1 2 :偏心擺動減速裝置 1 1 4 :輸入軸 116 :太陽齒輪（太陽旋轉體） 1 1 8 :傳動齒輪（偏心體軸驅動體） 1 2 0 .偏心體軸 1 2 2 A、1 2 2 B :偏心體 124A、124B :外齒齒輪（擺動體） 1 2 5 :間隔件 1 2 6 A、1 2 6 B :滾柱 1 2 8 :內齒齒輪 130 :殼體 132:第1托架（托架體） 1 3 4 :第2托架（托架體） 1 3 6、1 3 8 :斜角滾珠軸承 1 4 0 :螺栓 -17- 200905104 142 :螺栓孔 1 5 0、1 5 2 :滾針（軸承） P 1 0 1〜P 1 0 4 :間隔件的最內部 S 1 0 1、S 1 0 2 :傳動齒輪的最外部 R1 0 1 :圓周 -18-Each of the transmission gears 18' is assembled into a plurality of (in this example, three) eccentric body shafts 20, respectively. In each of the eccentric body shafts 20, the eccentric bodies 22A and 22B are disposed at a phase of 180°. When the input shaft 14 rotates, the three eccentric body shafts 20 are driven by the aforementioned transmission gears 18, and the three eccentric body groups 22A or 22B located at the same position in the axial direction of the three eccentric body shafts 20 are respectively Rotate in the same direction in the same phase. Two externally toothed gears (rocking bodies) 24A 200905104 and 24B' are fitted to the outer circumferences of the eccentric bodies 22A and 22B, respectively. Therefore, the two externally toothed gears 24 A and 24B are eccentrically rotated by a phase difference of 180° in accordance with the operation of each of the eccentric bodies 22 A and 22 B . The fitting between the eccentric bodies 22A and 22B and the externally toothed gears 24A and 24B is rotatably fitted via balls or rollers (rollers in this example) 2 6 A and 2 6 B. The externally toothed gears 24A, 24B are internally fitted to the internally toothed gear 28. The internal gear 28 is integrated with the housing 30, and the internal teeth are formed by a roller-shaped pin 28P. The externally toothed gears 24A, 24B and the internally toothed gear 28 are set to have a small number of teeth (e.g., 1 to 6). The first and second brackets (carrier bodies) 32 and 34 are disposed on both sides of the externally toothed gears 24 A and 24B in the axial direction. The two externally toothed gears 24A and 24B are disposed on the first and the second. The spacers 25 between the brackets 32, 34 and the two externally toothed gears 24A, 24B restrict movement in the axial direction. The first and second brackets 32 and 34 are coupled to each other via the bolt 40 and the bracket pin 42, and are entirely rotatably supported by the casing 30 via the tapered roller bearings 36 and 38. The eccentric oscillating speed reducer 12 of this configuration can be transmitted to the eccentric body shafts 20 by transmitting the rotation of the input shaft 14 through the transmission gear 18, and the eccentric bodies 2 2 A, 2 2 B of the eccentric body shafts 20 Rotating in the same phase respectively causes the externally toothed gears 24A, 24B to swing. As a result, since the meshing positions between the externally toothed gears 24A, 24B and the internal gear 28 are sequentially shifted, the externally toothed gears 24A, 24B and the internally toothed gear 2 can be accompanied by the rotation of the eccentric body shaft 20. 8 causes a relative displacement equivalent to the difference in the number of teeth. When the casing 3 (the internal gear 28) is fixed, the above relative displacement can be extracted from the pair of first and second brackets 32, 34, and the rotation of the first and second brackets 32, 34 is 200,905,104. When restrained, the above relative displacement can be extracted as the rotation of the casing 30 side (frame rotation). [Problem to be Solved by the Invention] However, in the eccentric oscillating reduction device having the above-described structure, for example, attention is paid to shortening in the axial direction. In the case where the transmission gear 18 is disposed between the externally toothed gears 2 4 A, 2 4 B as in the configuration of the embodiment to be described later, the outer circumference of the transmission gear 18 and the inner circumference of the spacer 25 are thousands. The problem that the size of the transmission gear 18 cannot be increased. Therefore, when it is desired to obtain a reduction ratio of a certain degree or more in the first stage deceleration portion (the sun gear 16 and the transmission gear 18), as in the fifth configuration shown, it is necessary to form the arrangement position of the transmission gear 18. The position at which the spacer 25 interferes (the outer side in the axial direction of the externally toothed gear 24A in the illustrated example) has a problem that the axial length of the entire reduction gear unit becomes long. The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to reduce the presence of a spacer without arranging the transmission gear in the same position as the spacer in the axial direction. The axial length of the device as a whole, and can reasonably eliminate the interference between the spacer and the transmission gear, and does not impair the original positioning function of the spacer, and can arrange a relatively large transmission gear in the axial direction. The same position as the spacer is used to obtain a large reduction ratio of the first stage of the speed reduction portion. 200905104 [Means for Solving the Problem] The present invention is an eccentric oscillating speed reducing device having a member: a sun rotating body; and an eccentric body shaft driving body which is rotated by the sun rotating body; and an eccentric body a shaft 'the eccentric body shaft is integrally rotated with the eccentric body shaft driving body; and a swinging body that is oscillated and rotated by the eccentric body shaft; and a bracket body, the bracket body and the swinging body In the present invention, the above-described problem can be solved by the following structure: A spacer is provided. The spacer is disposed at the same position in the axial direction as the eccentric body drive body, and the axial direction of the swing body can be restricted. In the movement, the spacer is formed such that the innermost portion of the device in the radial direction is the innermost circumference of the outer periphery in the radial direction of the device including the eccentric body shaft driving body, and is configured to stop the rotation of the bracket body. According to the present invention, the spacer is formed such that the innermost portion in the radial direction thereof becomes the outermost circumference inner side including the eccentric body shaft driving body. In this case, the eccentric body shaft oscillating body is disposed at the same position as the spacer in the axial direction (the state in which the axial length of the device can be shortened), and the radius of the spacer is sufficiently ensured by a specific portion. Since the width of the direction is set, the width in the radial direction of the interference portion between the spacer and the eccentric body shaft drive body can be set small. Therefore, the large-sized transmission gear described above can be accommodated, and the large reduction ratio of the first-stage deceleration portion (that is, the deceleration portion composed of the solar rotating body and the eccentric body shaft driving body) can be obtained. [Effects of the Invention] -8 - 200905104 According to the present invention, it is possible to obtain an eccentric oscillating speed reducing device which can maintain a high reduction ratio in the first stage and a shorter length in the axial direction. [Embodiment] [Embodiment] Hereinafter, an example of an embodiment of the present invention will be described in detail based on the drawings. Fig. 1 is a cross-sectional view showing an example of an eccentric oscillating reduction gear according to an embodiment of the present invention, and Fig. 2 is a cross-sectional view taken along line π - ϋ in the first drawing. The first figure is a cross-sectional view corresponding to the arrow I - I along the second drawing. The eccentric oscillating reduction gear unit 112 includes a sun gear (solar rotating body) 1 1 6 , the sun gear (solar rotating body) 1 16 is provided on the input shaft 1 1 4 , and the transmission gear (eccentric body shaft driving body) 1 1 8, the transmission gear (eccentric body shaft drive body) 1 18 is rotated by the sun gear 1 16; and the eccentric body shaft 1 2 0, the eccentric body shaft 1 2 0 is the transmission gear 1 1 8 - body rotation; and external gear (swing body) 124 Α, 124 Β, the external gear (swing body) 124 Α, 124 Β is oscillated and rotated by the eccentric body shaft 120; and the first and second brackets (bracket The first and second brackets (frame bodies) 132 and 134 are synchronized with the rotation portions of the externally toothed gears 124A and 124B. Hereinafter, a more detailed description will be given. The input shaft 114 is coupled to an output shaft of a motor not shown in the drawing. A sun gear 116 is integrally formed at the front end of the input shaft 114. The sun gear 1 16 is simultaneously meshed with a plurality of (in this case, 2) transmission gears 1 18 . 200905104 Each transmission gear π 8 is an eccentric body shaft 1 2 0 which is respectively assembled into a plurality of sets (in this example, 2 pieces), and the two eccentric body axes 1 2 0 can be driven simultaneously and in the same direction. In each of the eccentric body shafts 120, eccentric bodies 122A and 122b are provided at a phase of 180°, and the eccentric bodies 122A and 122B are respectively arranged in the axial direction. Further, at the same position in the axial direction of each axis, the eccentric body 1 2 2 Α group and the eccentric body 1 22B group of each axis are assembled in the same phase so as to be rotatable in the same direction. The externally toothed gears 124A are fitted to the outer circumferences of the two eccentric bodies 122A, respectively, and the externally toothed gears 124B are fitted to the outer circumferences of the two eccentric bodies 122B, respectively. The fitting between the eccentric bodies 122A and 122B and the externally toothed gears 124A and 124B is rotatably fitted via the rollers 126A and 126B. Thus, the externally toothed gears 124A and 124B are respectively separated by a phase difference of 180 degrees. The inner joint is meshed with the internal gear 128. The external gears 124A and 124B are arranged in parallel in the axial direction (12 4A, 124B) in order to secure the transmission capacity. The position of the outer teeth gears 124A, 124B in the axial direction is limited by the angled ball bearings 136, 138 and the spacers 125. The construction of the spacer 125 will be described in detail later. The internal gear 128 is formed integrally with the housing 130, and the internal teeth are formed by a cylindrical pin 128P. The externally toothed gears 124A and 124B and the internally toothed gear 128 are set to have a small difference in the number of teeth (for example, a difference in the number of teeth of about 1 to 6). In this example, the pin 1 2 8 P corresponding to the internal tooth of the internal gear 1 28 is assembled by using a two-group intermittent setting method (two empty spaces for each two). In the case of the action generated by the meshing, it is possible to obtain the same operation as that of the above-mentioned "intermittent setting" (for example, the example shown in Fig. 6) - 200905104. The "small amount of difference in the number of teeth" means that the number of teeth of the external teeth and the internal teeth is different in the state where the above-described intermittent setting is not employed. The first and second brackets 132 and 134 are disposed on both sides of the external gears 124A and 124B in the axial direction. The second and second brackets 132 and 134 are connected to each other via a bracket pin i34A that protrudes from the bolt 140 and the second bracket 134 side, and the entire diagonal ball bearing 1 3 6 is interposed therebetween. 138 is rotatably supported by the housing 130. The eccentric body shaft 120' is supported by the first and second brackets 1 3 2, 1 3 4 via the needle rollers 150 and 152. The needle rollers 丨 5 〇 and 1 5 2 are used by using the eccentric body shaft 120 as the inner wheel, respectively, and the second and second brackets 丨 32, ! 34 is used as an outer wheel to constitute a "needle bearing". However, since the needle rollers 150 and 125 cannot separately transmit the reaction force in the thrust direction, in the embodiment, the following structure is employed for the positioning of the eccentric body axis 1 0 0 in the axial direction. That is, the step portion 1 7 〇 is formed on the eccentric body axis 1 2 0! 7 2. In addition, the step portions 1 70 and 1 72 are used to restrict the eccentric body shaft 1 between the step portions 丨 70 and i 72 and the first and second brackets 1 3 2 and 1 34. 2 Shims 174, 176 that move in the direction of the axis of the crucible. The spacers 174 and 176' transmit the alignment of the eccentric body axis 1 2 〇 in the axial direction by the step portions 1 7 0 and 1 7 2 by abutting against the first 'second brackets 132 and 134'. The positioning in the axial direction of 1 2 6 A, 1 18 and 1 2 6 B is performed by holding the roller 1 26A, the transmission gear 8 and the other roller 1 2 6 B therebetween. The spacers 174, 176 are arranged such that any one of the first and second brackets 132, 134 and the step portions 170, 172 can be rotated relative to each other. -11 - 200905104 and the drawing numbers 1 6 7 and 1 6 9 in the drawing are needle roller holders for restricting the movement of the needle rollers 1 50 and 1 5 2 in the axial direction. Further, reference numeral 1 42 is a bolt hole for connecting the first and second brackets 132 and 134 and the mating member (driven machine), and 180 is a jig attachment portion for mounting the jig. The tool (not shown) is used to stop the rotation of the eccentric body axis when it is processed. Here, the structure of the spacer 1 25 will be described. The portion of the external teeth of the externally toothed gear 124 that is shielded by the spacer 125 should be indicated by a broken line, but is drawn with a solid line for convenience. The spacer 1 2 5 is formed so that the innermost portion of the device in the radial direction (four positions of Ρ101 to Ρ1 04 in the example of the figure) becomes the outermost portion of the radial direction of the device including the transmission gear 18 (S101 in the example) The shape of the inner side of the circumference R 1 0 1 of the two positions of S102). The spacer 1 2 5 has an annular shape as a whole, and the inner peripheral side has a first recess 125 可 (2) that can ensure a gap 5 with the transmission gear 1 18 in order to avoid interference with the transmission gear 1 18 . position). Further, the spacer 125 has a second recess 125 (four positions) which is formed in a shape partially along the outer circumference of the bracket pin 134. By the engagement between the second recess 1 ΜΒ and the bracket pin 1 3 4 ,, the spacer 1 25 and the first and second brackets 132 and 134 are integrated in the circumferential direction, thus The structure in which the spacer 125 stops rotating the first and second brackets 132 and 134 can be configured. Next, the action of the eccentric oscillating speed reducing device 1 12 will be described. When the input shaft 1 14 rotates, the two eccentric body shafts 1 20 are simultaneously decelerated by the transmission gears 1 18 engaged with the input shafts 14 . In this way, the eccentric body 122A group and the 122B group integrally mounted on the eccentric body shafts 120 rotate in the same phase with -12-200905104, and the external gears 12 4 A, 12 4 B are connected to the internal gears. In the state of 128, each swings and rotates. The internal gear 128 is integrated with the housing 1300. [Because it assumes a fixed state", when the eccentric shaft 1 2 0 rotates, the external gears 124A, 124B are oscillated and rotated by the eccentric bodies 122A, 122B, and the The meshing position of the externally toothed gears 124A, 124B and the internally toothed gear 1 28 is sequentially displaced. At this time, since the number of teeth of the externally toothed gears 124A and 124B is slightly smaller than that of the internally toothed gear 128, a phase shift (rotation) corresponding to the difference in the number of teeth is formed to the internally toothed gear 128 in a fixed state. Therefore, the 'eccentric body axis 120 is formed to revolve around the input shaft at a speed corresponding to the rotation portion', and the first and second brackets 132 and 134 that support the eccentric body shaft 120 correspond to the The speed of the revolution speed is rotated. Since the first and second brackets 132 and 134 are coupled by the bolt 140 and the bracket pin 134A, the first and second brackets 132 and 134 are integrally formed (one large block body is formed) and slowly rotated. A mating machine (driven machine) not shown in the plane connected by the bolt holes 1 42 is driven. Furthermore, as in this embodiment, when the housing 1 30 (the internal gear 1 2 8 ) is fixed, the relative displacement between the external gear 1 2 4 A, 1 2 4 B and the internal gear 1 2 8 It can be taken out from the first and second brackets 132 and 134, and the first and second brackets 1 can be transmitted when the rotation of the first and second brackets 1 3 2, 1 3 4 is restricted. 3, 1 3 4 Rotational restraint 'This relative displacement is taken out as the rotation of the casing 1 3 side (frame rotation). Here, the eccentric oscillating speed reduction device 1 1 2 of this embodiment has the first and second brackets 132 and 134 on both sides of the externally toothed gears 124A and 124B, and 13-200905104 by the first 'secondary The brackets 132 and 134 support the two eccentric body shafts 120' from both ends, and can swing and rotate in a state where the support rigidity is high and the externally toothed gears i 2 4 A and 1 2 4 B are stable. Since the two externally toothed gears 124A and 124B are held by the pair of the second and second brackets 1 3 2 and 1 3 4 and the spacers 25 are disposed at the center of the axial direction thereof, there is no need to additionally set an extra The positioning means such as the buckle can limit the movement in the axial direction. Here, the 'interval member 1 2 5 ' is the inner side of the circumference R101 of the outermost portion S101, S102 in the radial direction of the device including the transmission gear 118 due to the innermost portion P101 to P1 04 of the device radial direction, in the innermost pi〇i~ The vicinity of P 1 04 is formed: an extremely large thickness w 1 0 1 can be secured in the radial direction, and a good position can be performed on the externally toothed gears 1 24 A, 124B located on both sides of the spacer 1 2 5 . Therefore, the outer side of the outermost portions S101, S1〇2 of the transmission gear 118 is formed such that the extremely thin width W1 02 can be sufficiently ensured, and only the large size of the transmission gear 1 18 can be ensured. Therefore, the deceleration ratio can be set to a high reduction ratio that can be ensured by the first stage reduction unit (sun gear 1 16 and transmission gear 1 18). Therefore, the transmission gear 118 and the spacer 1 25 can be disposed at the same position in the axial direction without hindrance, and the length in the axial direction can be shortened because the bracket pin 1 3 4 A and the second recess 1 2 5 B can be used. 'The spacers 1 2 5 stop the rotation of the first and second brackets 1 3 2, 1 3 4 (integrally actuated)' so that it can be formed between the spacer 1 2 5 and the transmission gear 1 1 8 : lasting The state in which the specific gap 6 is ensured is maintained. Therefore, the spacer 1 2 5 does not come into contact with the transmission gear 1 18 during operation. -14- 200905104 In this embodiment, as described above, as the large reduction ratio of the first stage speed reduction portion (the sun gear 1 16 and the transmission gear 11 8 ) can be ensured, and the transmission gear 1 1 is 8 is disposed between the two externally toothed gears 1 2 4 A and 1 2 4 B to obtain "the advantage of shortening the axial direction". However, in the present invention, there is no particular limitation on how to utilize the above advantages. That is, the benefit is as described in the text, and in addition to contributing to shortening the axial direction of the device, as shown in this embodiment, the portion can also be used for the formation of the fixture mounting portion 180, the fixture mounting portion. 1 800 is a jig (not shown) for preventing the rotation of the eccentric body shaft 1 2 0. In this way, since the eccentric body shaft 120 and the eccentric bodies 122A and 122B can be gripped at a time to perform high-precision machining, the formation can be shortened, the processing cost can be reduced, and the machining accuracy can be improved. Not only that, for example, when the length of the axial direction is allowed to be the same as the existing one, the above-mentioned benefits can also be utilized in the direction of increasing the transmission capacity. Next, other embodiments of the present invention will be described using Figs. 3 and 4 . In the eccentric oscillating speed reducing device 2 1 2, the spacer 225 is composed of two members 225-1 and 225-2 which are discontinuous in the circumferential direction. The innermost portions S201 and S2〇2 of the respective members 22 to 5-1 and 225-2' in the radial direction of the respective devices are disposed so as to be disposed inside the circumference R201 including the outermost sides S2〇i and S202 of the transmission gear 218 in the radial direction of the device. The term "non-continuous in the circumferential direction" as used above means "is composed of two or more members (not a single member) in the circumferential direction, not in the axial direction". Each member 225-1, 225-2 has a second recess 225-1B, 225-2B, and each of the second recesses 225-1B, 225-2B has a portion along the outer circumference of the bracket pin 234-15-200905104. By the bracket pin 23 4A and the second recesses 225B-1B and 225-2B, the rotation of the spacers 225-1 and 255-2 to the first and second brackets 232 and 234 can be stopped. In this embodiment, since the spacer is not present outside the device in the radial direction of the outermost portions S 2 0 1 and S2 02 of the transmission gear 2 18 , the design of the transmission gear 2 18 ensures maximum design margin. (elastic). The other configurations described above are basically the same as those of the previously described embodiment, and therefore the same reference numerals are used for the same or corresponding parts in the drawings, and the description thereof will be omitted. As far as the shape of the spacer is concerned, the shape shown in the above embodiment is only one of the examples. It is conceivable to adopt various shapes. For example, in addition to the two or more members shown in the second embodiment, as the spacer, the annular spacer may not be excluded. In addition, there is no particular limitation on the number of spacers to be configured. [Industrial Applicability] The present invention can be used as an improved product in which the eccentric oscillating speed reducing device is conventionally introduced as a high reduction ratio and a further shortening of the axial length. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a longitudinal sectional view showing an eccentric oscillating deceleration device according to an embodiment of the present invention. Fig. 2 is a cross-sectional view taken along the line π _ π of the above-described reduction gear unit. -16- 200905104 Fig. 3 is a cross-sectional view showing an eccentric oscillating speed reduction device according to another example of the present invention. Fig. 4 is a cross-sectional view taken along line IV-IV of the arrow of Fig. 3. Fig. 5 is a cross-sectional view showing an example of a conventional eccentric oscillating reduction device. Figure 6 is a cross-sectional view taken along line VI-VI of Figure 5. [Description of main component symbols] 1 1 2 : Eccentric swing reduction gear 1 1 4 : Input shaft 116 : Sun gear (solar rotating body) 1 1 8 : Transmission gear (eccentric body shaft drive) 1 2 0 . Eccentric shaft 1 2 2 A, 1 2 2 B : eccentric body 124A, 124B: external gear (swing body) 1 2 5 : spacer 1 2 6 A, 1 2 6 B : roller 1 2 8 : internal gear 130 : shell Body 132: 1st bracket (bracket body) 1 3 4 : 2nd bracket (bracket body) 1 3 6, 1 3 8 : Angled ball bearing 1 4 0 : Bolt-17- 200905104 142 : Bolt hole 1 5 0, 1 5 2 : Needle roller (bearing) P 1 0 1 to P 1 0 4 : The innermost part of the spacer S 1 0 1 , S 1 0 2 : the outermost part of the transmission gear R1 0 1 : circumference -18 -