JP3877014B2

JP3877014B2 - Series of two-stage planetary gear reducers

Info

Publication number: JP3877014B2
Application number: JP12689996A
Authority: JP
Inventors: 博亀田
Original assignee: Harmonic Drive Systems Inc
Current assignee: Harmonic Drive Systems Inc
Priority date: 1996-05-22
Filing date: 1996-05-22
Publication date: 2007-02-07
Anticipated expiration: 2016-05-22
Also published as: JPH09310737A

Description

【０００１】
【発明の属する技術分野】
本発明は２段型遊星歯車減速機に関し、特に、シリーズ化された２段型遊星歯車減速機の各サイズにおける構成部品の共通化を図ることにより、部品点数の削減、製造価格の低減および組立工数の短縮等のために有利な構成を備えた２段型遊星歯車減速機のシリーズに関するものである。
【０００２】
【従来の技術】
２段型遊星歯車減速機としては、本願人により図３に示す構成のものが提案されている。この２段型遊星歯車減速機１は、前段遊星歯車機構２と後段遊星歯車機構３とを備えている。後段遊星歯車機構３は、内周面に内歯４が形成された環状の内歯歯車５と、当該内歯歯車５の内周面における内歯４の両側の部分に配置した一対の主軸受け６、７によってそれぞれ回転自在に支持された第１および第２のキャリア片８、９と、これら第１および第２のキャリア片８、９の間に架け渡した複数本の遊星軸１０の回りにそれぞれ回転自在に支持され、内歯４に噛み合っている複数の遊星歯車１１と、第１のキャリア片８、９を貫通して装置軸線１ａの方向に延びているピニオン軸１２の外周に形成され、遊星歯車１１に噛み合っている太陽歯車１３と、第２のキャリア片９に連結されていると共に装置軸線１ａの方向に延びている出力軸１４とを備えている。
【０００３】
前段遊星歯車機構２は、後段遊星歯車機構３の第１のキャリア片８の内周面に形成した内歯１５と、この内歯１５に噛み合っている複数の遊星歯車１６と、これらの遊星歯車１６を回転自在に支持しているキャリア１７と、装置軸線方向に延びるピニオン軸１８の外周に形成され、遊星歯車１６に噛み合っている太陽歯車１９とを有している。そして、キャリア１７は後段側のピニオン軸１２に連結されている。
【０００４】
【発明が解決しようとする課題】
このような構成の遊星歯車装置においては次のような解決すべき課題がある。すなわち、この構成の２段型遊星歯車減速機は、歯車を始めとして多数の高精度部品によって構成されている。このために、製造価格を低減することが要望されている。
【０００５】
そこで、本発明の課題は、製造価格を低減することの可能な構造を備えた２段型遊星歯車減速機のシリーズを実現することにある。
【０００６】
【課題を解決するための手段】
本発明は、同一構造でサイズの異なる複数の２段型遊星歯車減速機からなる２段型遊星歯車減速機のシリーズであって、各サイズの２段型遊星歯車減速機は、前段減速部セットを含む前段遊星歯車機構と、後段減速部セットを含む後段遊星歯車機構から構成されている。
【０００７】
前記後段遊星歯車機構は、後段内歯歯車と、当該後段内歯歯車の両側に配置した一対の主軸受けによってそれぞれ回転自在に支持された第１および第２のキャリア片からなる後段キャリアと、これら第１および第２のキャリア片の間に架け渡した複数本の後段遊星軸の回りに後段遊星軸受けを介して回転自在に支持され、前記後段内歯歯車に噛み合っている複数の後段遊星歯車と、前記第１のキャリア片を貫通して装置軸線方向に延びている後段ピニオン軸の外周に形成され、前記後段遊星歯車に噛み合っている後段太陽歯車と、前記第２のキャリア片に連結されていると共に装置軸線方向に延びている出力軸とを備えている。
【０００８】
前記前段遊星歯車機構は、前記第１のキャリア片に連結された前段内歯歯車と、前記後段ピニオン軸に連結された前段キャリアと、この前段キャリアに固着した複数の前段遊星軸の回りに前段遊星軸受けを介して回転自在に支持され、前記前段内歯に噛み合っている複数の前段遊星歯車と、前記後段ピニオン軸に対して同軸状態に配列されている入力ピニオン軸の外周に形成され、前記前段遊星歯車に噛み合っている前段太陽歯車とを備えている。
【０００９】
上記の構成に加えて、前記後段内歯歯車は内周面に内歯が形成されたリング状歯車であり、装置ハウジングに連結固定されており、前記前段内歯歯車も内周面に内歯が形成されたリング状歯車であって、前記第１のキャリア片の環状端面に連結固定されており、これら後段内歯歯車および前段内歯歯車は同一の歯数となっている。また、前記前段減速部セットは、前記前段内歯歯車、前段遊星軸、前段遊星軸受け、および前段遊星歯車からなり、前記後段減速部セットは、前記後段内歯歯車、後段遊星軸、後段遊星軸受け、および後段遊星歯車からなっている。
【００１０】
さらには、第１のサイズの２段型遊星歯車減速機に組み込まれる前記前段減速部セットは、当該第１のサイズよりも小さな第２のサイズの２段型遊星歯車減速機に組み込まれる前記後段減速部セットと共用のものとしてある。
【００１１】
ここで、前記第１のサイズの２段型遊星歯車減速機に組み込まれる前記後段減速部セットは、当該第１のサイズより大きな第３のサイズの２段型遊星歯車減速機に組み込まれる前記前段減速部セットと共用のものとすることができる。
【００１２】
このように構成した本発明の２段型遊星歯車減速機によって、サイズ・速比の異なる同一構造の２段型遊星歯車減速機のシリーズを製造した場合には、型番（サイズ）・速比にわたる部品の共通化を図ることができる。すなわち、前段減速部セットは、例えば、当該２段遊星歯車減速機よりもサイズの小さい２段型遊星歯車減速機の後段減速部セットとして用いることができる。また、当該２段型遊星歯車減速機の後段減速部セットは、これよりもサイズの大きな２段型遊星歯車減速機の前段減速部セットとして用いることができる。
【００１３】
この結果、単位生産期間内における各サイズおよび各サイズ毎の各速比の２段型遊星歯車減速機の総生産台数（プロダクトミックス）が、従来における２段型遊星歯車減速機のシリーズと同一であっても、シリーズの最小サイズ付近の前段減速部セット、および最大サイズ付近の後段減速部セットを除き、シリーズ全体を通して、これらの減速部セットが最低２回使用されるので、生産部品点数をほぼ半減でき、その生産数量がほぼ倍増することになる。
【００１４】
このことは、当該部品の加工ロッドサイズの倍増、在庫点数と数量の減少、歯切工具・治具・取付具の設備数の減少、および製造管理の簡素化を容易にして、製造価格を大幅に低減できることを意味する。
【００１５】
また、本発明を適用した２段型遊星歯車減速機の設計においては、前後のサイズにわたる単位セット（減速部セット）の重用によって、一層単純な構造の採用を可能にし、更に、同一寸法・公差の多用となり、設計工程並びに検図を含む管理労力の軽減にも役立つ。さらには、同一寸法・公差の多用は、関連部品の機械加工に際し、加工工数の低減、治工具種類の縮小や製造価格の低減に繋がるという利点も得られる。
【００１６】
【発明の実施の形態】
図１には、本発明を適用した２段型遊星歯車減速機を示してある。この図に示すように、２段型遊星歯車減速機２０は、円筒状の装置ハウジング２１の内部に、前段遊星歯車機構２２と後段遊星歯車機構２３とが組み込まれた構成となっている。
【００１７】
後段遊星歯車機構２３は、内周面に内歯２４が形成されたリング状の後段内歯歯車２５と、当該後段内歯歯車２５の内周面における内歯２４の両側の部分に配置した一対の主軸受け２６、２７によってそれぞれ回転自在に支持された第１および第２のキャリア部分２８Ａ、２８Ｂからなる後段キャリア２９と、これら第１および第２のキャリア部分２８Ａ、２８Ｂの間に架け渡した複数本の後段遊星軸３０の回りにそれぞれ、ニードルベアリングからなる後段遊星軸受け３０Ａを介して回転自在に支持され、内歯２４に噛み合っている複数の後段遊星歯車３１と、第１のキャリア部分２８Ａを貫通して装置軸線２０ａの方向に延びている後段ピニオン軸３２の外周に形成され、後段遊星歯車３１に噛み合っている後段太陽歯車３３と、第２のキャリア部分２８Ｂに対して一体形成され、装置軸線２０ａの方向に延びている出力軸３４とを備えている。
【００１８】
前段遊星歯車機構２２は、後段側の第１のキャリア部分２８Ａの環状をした段状端面２８ａに連結固定されたリング状の前段内歯歯車３５と、この内周面に形成した内歯３５ａに噛み合っている複数の前段遊星歯車３６と、これらの前段遊星歯車３６を、前段遊星軸受け３６Ａを介して回転自在に支持している前段遊星軸３７Ａと、この前段遊星軸３７Ａを支持しているキャリア３７と、装置軸線２０ａの方向に延びる入力ピニオン軸３８の外周に形成され、遊星歯車３６に噛み合っている太陽歯車３９とを有している。そして、キャリア３７は後段ピニオン軸３２に連結されている。
【００１９】
ここで、後段内歯歯車２５と前段内歯歯車３５は同一の歯数となるように設定されている。
【００２０】
また、図２（Ａ）において斜線で示すように、前段内歯歯車３５、前段遊星軸３７Ａ、前段遊星軸受け３６Ａ、および前段遊星歯車３６からなる前段減速部セット２２Ａは、当該２段型遊星歯車減速機２０よりも小さいサイズの同一構造の２段型遊星歯車減速機に組み込まれる後段減速部セットと共用のものとしてある。同様に、後段内歯歯車２５、後段遊星軸３０、後段遊星軸受け３０Ａおよび後段遊星歯車３１からなる後段減速部セット２３Ａは、当該２段型遊星歯車減速機よりも大きなサイズの同一構造の２段型遊星歯車減速機に組み込まれる前段減速部ユニットと共用のものとしてある。
【００２１】
例えば、図２（Ｂ）に概念的に示すように、２段型遊星歯車減速機２０の各サイズからなるシリーズにおいて、サイズが小さい側から大きい側に向けて、減速機２０（１）、２０（２），２０（３）、２０（４）・・・を含むものとする。この場合、例えば、減速機２０（１）の後段減速部セット２３Ａ（１）は、２サイズ上の減速機２０（３）における前段減速部セットと共用とされる。
【００２２】
また、同様に、減速機２０（２）の後段減速部セット２３Ａ（２）は、２サイズ上の減速機２０（４）における前段減速部セットと共用とされる。このことは、逆に表現すると、減速機２０（４）の前段減速部セットは２サイズ小さい減速機２０（２）の後段減速部セットと共用とされることになる。
【００２３】
なお、後段側のキャリア２９は、従来における図３に示すような左右一対のキャリア８、９を一体化した構成となっている。これに加えて、このように一体化したキャリア２９と出力軸３４とを一体化した構成の一部材として製作されている。複数本の遊星軸３０は打ち込みピンからなっており、内歯２４を挟み左右に位置しているキャリア部分２８Ａ、２８Ｂの間に打ち込み固定したものである。
【００２４】
また、前段側キャリア３７に後段ピニオン軸３２が締結された締結体は、当該締結体の軸端、すなわち、ピニオン軸３２の軸端３２ａが鋼球によって支持されている。図示の例では、ピニオン軸３２の軸端３２ａが対峙しているキャリア２９の環状端面２９ａには、軸線２０ａの方向に溝２９ｂが掘られ、そこに鋼球２９ｃが装着されている。そして、ピニオン軸の軸端３２ａの側には、鋼球２９ｃの表面に当接した円錐状内周面３２ｂを備えた溝が形成されている。このように、ピニオン軸３２の軸端３２ａの側は、鋼球２９ｃによって支持されている。
【００２５】
一方、２段型遊星歯車減速機２０では、その一方の主軸受け２７に対する予圧を次のように付与している。すなわち、当該主軸受け２７の内輪２７ａの環状端面には、止め輪４１が配置されている。この止め輪４１は、内輪２７ａに当たっている側の端面は平坦な環状端面である。しかし、反対側の環状端面には、その内周側の部分に環状傾斜面が形成されている。
【００２６】
この止め輪４１が嵌まる止め輪溝４２が後段側キャリア２９の外周面に形成されている。この止め輪溝４２には、止め輪４１の環状傾斜面に対応する環状傾斜面が形成されている。止め輪４１を広げて止め輪溝４２に装着すると、止め輪４１が半径方向の内側に向けて弾性復帰する。この弾性復帰力が発生すると、傾斜面相互のくさび効果によって、内輪２７ａを軸線方向に押し付ける押し付け力が発生する。
【００２７】
【発明の効果】
以上説明したように、本発明の２段型遊星歯車減速機においては、前段遊星歯車機構の前段内歯歯車および後段遊星歯車機構の後段内歯歯車をリング状の歯車とすると共に、その歯数を同一としてある。また、前段遊星歯車機構を構成している前段内歯歯車、前段遊星軸、前段遊星軸受、および前段遊星歯車からなる前段減速部セットを、当該２段型遊星歯車減速機よりも小さいサイズの同一構造の２段型遊星歯車減速機に組み込まれる後段減速部セットと共用のものとしてある。あるいは、後段遊星歯車機構を構成している後段内歯歯車、後段遊星軸、後段遊星軸受けおよび後段遊星歯車からなる後段減速部セットを、当該２段型遊星歯車減速機よりも大きなサイズの同一構造の２段型遊星歯車減速機に組み込まれる前段減速部セットと共用のものとしてある。
【００２８】
従って、このように構成した本発明の２段型遊星歯車減速機によって、サイズ・速比の異なる同一構造の２段型遊星歯車減速機のシリーズを製造した場合には、型番（サイズ）・速比にわたる部品の共通化を図ることができる。この結果、単位生産期間内における各サイズおよび各サイズ毎の各速比の２段型遊星歯車減速機の総生産台数（プロダクトミックス）が、従来における２段型遊星歯車減速機のシリーズと同一であっても、シリーズの最小サイズ付近の前段減速部セット、および最大サイズ付近の後段減速部セットを除き、シリーズ全体を通して、これらの減速部セットが最低２回使用されるので、生産部品点数をほぼ半減でき、その生産数量がほぼ倍増することになる。このようにして、本発明によれば、２段型遊星歯車装置を廉価に製造することが可能になる。
【図面の簡単な説明】
【図１】（Ａ）は本発明を適用した２段型遊星歯車減速機の概略断面図、（Ｂ）はその歯車の配列及び主軸受けの配置を模式的に示す説明図である。
【図２】（Ａ）は図１の減速機の前段減速部セットおよび後段減速部セットの部分を斜線で表した説明図、（Ｂ）は減速部セットの共用化を示す説明図である。
【図３】２段型遊星歯車減速機を示す概略断面構成図である。
【符号の説明】
２０２段型遊星歯車減速機
２１装置ハウジング
２２前段側遊星歯車機構
２２Ａ前段減速部セット
２３後段側遊星歯車機構
２３Ａ後段減速部セット
２４内歯
２５後段内歯歯車
２６、２７主軸受け
２８Ａ、２８Ｂキャリア部分
２９後段キャリア
３０後段遊星軸
３１後段遊星歯車
３２後段ピニオン軸
３３後段太陽歯車
３４出力軸
３５前段内歯歯車
３６前段遊星歯車
３６Ａ前段遊星軸受け
３７前段キャリア
３７Ａ前段遊星軸
３８入力ピニオン軸
３９前段太陽歯車[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a two-stage planetary gear speed reducer, and in particular, by reducing the number of parts, reducing the manufacturing cost, and assembling by sharing components in each size of a series of two-stage planetary gear speed reducers. The present invention relates to a series of two-stage planetary gear reducers having an advantageous configuration for shortening man-hours and the like.
[0002]
[Prior art]
As the two-stage planetary gear speed reducer, the structure shown in FIG. 3 has been proposed by the present applicant. The two-stage planetary gear reducer 1 includes a front planetary gear mechanism 2 and a rear planetary gear mechanism 3. The rear stage planetary gear mechanism 3 includes an annular internal gear 5 having an inner tooth 4 formed on the inner peripheral surface, and a pair of main bearings disposed on both sides of the inner tooth 4 on the inner peripheral surface of the internal gear 5. First and second carrier pieces 8 and 9 rotatably supported by 6, 7 and around the plurality of planetary shafts 10 spanned between the first and second carrier pieces 8 and 9, respectively. Are formed on the outer periphery of a plurality of planetary gears 11 meshed with the inner teeth 4 and the pinion shaft 12 extending through the first carrier pieces 8 and 9 in the direction of the device axis 1a. And a sun gear 13 meshing with the planetary gear 11 and an output shaft 14 connected to the second carrier piece 9 and extending in the direction of the device axis 1a.
[0003]
The front planetary gear mechanism 2 includes inner teeth 15 formed on the inner peripheral surface of the first carrier piece 8 of the rear planetary gear mechanism 3, a plurality of planetary gears 16 meshed with the inner teeth 15, and these planetary gears. And a sun gear 19 which is formed on the outer periphery of a pinion shaft 18 extending in the apparatus axial direction and meshes with the planetary gear 16. The carrier 17 is connected to the pinion shaft 12 on the rear stage side.
[0004]
[Problems to be solved by the invention]
The planetary gear device having such a configuration has the following problems to be solved. That is, the two-stage planetary gear speed reducer having this configuration is constituted by a large number of high-precision parts including gears. For this reason, it is desired to reduce the manufacturing price.
[0005]
Accordingly, an object of the present invention is to realize a series of two-stage planetary gear reducers having a structure capable of reducing the manufacturing cost.
[0006]
[Means for Solving the Problems]
The present invention is a series of two-stage planetary gear speed reducers composed of a plurality of two-stage planetary gear speed reducers having the same structure and different sizes. And a rear planetary gear mechanism including a rear reduction gear set.
[0007]
The rear planetary gear mechanism includes a rear internal gear, a rear carrier composed of first and second carrier pieces rotatably supported by a pair of main bearings disposed on both sides of the rear internal gear, and A plurality of rear planetary gears rotatably supported via a rear planetary bearing around a plurality of rear planetary shafts spanned between the first and second carrier pieces and meshing with the rear internal gear; A rear-stage sun gear that is formed on an outer periphery of a rear-stage pinion shaft that extends through the first carrier piece and extends in the apparatus axis direction, and is connected to the second-stage carrier gear. And an output shaft extending in the apparatus axial direction.
[0008]
The front stage planetary gear mechanism includes a front stage internal gear connected to the first carrier piece, a front stage carrier connected to the rear stage pinion shaft, and a plurality of front stage planetary shafts fixed to the front stage carrier. A plurality of front planetary gears rotatably supported through planetary bearings and meshing with the front inner teeth, and formed on the outer periphery of the input pinion shaft arranged coaxially with the rear pinion shaft, And a front sun gear meshing with the front planetary gear.
[0009]
In addition to the above structure, the rear stage internal gear is ring-shaped gear internal teeth formed on an inner circumferential surface, is connected and fixed to the housing, the inner peripheral surface also the front internal gear internal teeth Is formed and connected and fixed to the annular end surface of the first carrier piece, and the rear internal gear and the front internal gear have the same number of teeth. The front stage reduction unit set includes the front stage internal gear, the front stage planetary shaft, the front stage planetary bearing, and the front stage planetary gear, and the rear stage reduction unit set includes the rear stage internal gear, the rear stage planetary shaft, and the rear stage planetary bearing. , And rear planetary gears.
[0010]
Furthermore, the front stage reduction unit set incorporated in the first-size two-stage planetary gear speed reducer includes the rear stage incorporated in the second-stage two-stage planetary gear speed reducer that is smaller than the first size. Shared with the reduction gear set.
[0011]
Here, the first second-stage reduction gear unit set to be incorporated into the two-stage type planetary gear reducer size, the front to be incorporated into the two-stage planetary gear speed reducer of large third size than the first size It can be shared with the speed reducer set.
[0012]
When a series of two-stage planetary gear reducers having the same structure with different sizes and speed ratios is manufactured by the two-stage planetary gear speed reducer of the present invention configured as described above, the model number (size) and speed ratio are covered. Parts can be shared. That is, the front deceleration section sets, for example, can be used as a rear stage speed reducer set of two-stage planetary reduction gear smaller in size than the two-stage planetary reduction gear. Further, subsequent deceleration section sets the two-stage planetary reduction gear can be used as a pre-stage speed reducing portion sets the size of the large two-stage planetary reduction gear than this.
[0013]
As a result, the total production number (product mix) of the two-stage planetary gear reducers of each size and each speed ratio in each unit production period is the same as the conventional two-stage planetary gear reducer series. even, front deceleration portion set near the minimum size of the series, and except for the rear stage speed reducer set near the maximum size, throughout the series, since these deceleration portion set is used at least twice, the production of parts substantially The production volume can be almost doubled.
[0014]
This greatly doubles the machining rod size of the part, reduces the number of stocks and quantities, reduces the number of gear cutting tools, jigs and fixtures, and simplifies manufacturing management , greatly increasing the manufacturing price. It means that it can be reduced.
[0015]
In the design of a two-stage planetary gear reducer to which the present invention is applied, it is possible to adopt a simpler structure by using a unit set (reduction unit set) over the front and rear sizes, and also to have the same dimensions and tolerances. It is also useful for reducing management effort including design process and drawing. Furthermore, the heavy use of the same dimensions and tolerances also has the advantage of reducing the number of processing steps, reducing the types of jigs and tools, and reducing the manufacturing price when machining related parts.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a two-stage planetary gear reducer to which the present invention is applied. As shown in this figure, the two-stage planetary gear speed reducer 20 has a configuration in which a front-stage planetary gear mechanism 22 and a rear-stage planetary gear mechanism 23 are incorporated in a cylindrical device housing 21.
[0017]
The rear stage planetary gear mechanism 23 is a pair of ring-shaped rear stage internal gears 25 in which inner teeth 24 are formed on the inner peripheral surface and a pair of portions disposed on both sides of the inner teeth 24 on the inner peripheral surface of the rear stage internal gear 25. Between the first carrier portion 28A and the second carrier portion 28B, and the rear carrier 29 composed of the first and second carrier portions 28A and 28B rotatably supported by the main bearings 26 and 27, respectively. A plurality of rear planetary gears 31 that are rotatably supported around a plurality of rear planetary shafts 30 via respective rear planetary bearings 30A made up of needle bearings and mesh with the inner teeth 24, and a first carrier portion 28A. A second-stage sun gear 33 that is formed on the outer periphery of the second-stage pinion shaft 32 that extends in the direction of the device axis 20a and meshes with the second-stage planetary gear 31; It is integrally formed with respect Yaria portion 28B, and an output shaft 34 extending in the direction of the device axis 20a.
[0018]
The front planetary gear mechanism 22 includes a ring-shaped front internal gear 35 connected and fixed to the annular stepped end surface 28a of the first carrier portion 28A on the rear stage side, and an internal tooth 35a formed on the inner peripheral surface. A plurality of front stage planetary gears 36 engaged with each other, a front stage planetary axis 37A that rotatably supports these front stage planetary gears 36 via a front stage planetary bearing 36A, and a carrier that supports the front stage planetary axis 37A 37 and a sun gear 39 formed on the outer periphery of the input pinion shaft 38 extending in the direction of the device axis 20 a and meshing with the planetary gear 36. The carrier 37 is connected to the rear-stage pinion shaft 32.
[0019]
Here, the rear internal gear 25 and the front internal gear 35 are set to have the same number of teeth.
[0020]
2A, the front-stage reduction gear set 22A including the front-stage internal gear 35, the front-stage planetary shaft 37A, the front-stage planetary bearing 36A, and the front-stage planetary gear 36 includes the two-stage planetary gear. It is used in common with the rear stage reduction gear set incorporated in the two-stage planetary gear reduction machine of the same structure having a size smaller than that of the reduction gear 20. Similarly, the rear stage reduction gear set 23A composed of the rear stage internal gear 25, the rear stage planetary shaft 30, the rear stage planetary bearing 30A, and the rear stage planetary gear 31 has two stages of the same structure having a larger size than the two-stage planetary gear reducer. This is used in common with the previous stage reduction unit incorporated in the type planetary gear reducer.
[0021]
For example, as conceptually shown in FIG. 2 (B), in a series of sizes of the two-stage planetary gear speed reducer 20, the speed reducers 20 (1), 20 from the smaller size side toward the larger side. (2), 20 (3), 20 (4). In this case, for example, the rear-stage reduction unit set 23A (1) of the reduction gear 20 (1) is shared with the front-stage reduction unit set in the two- size reduction gear 20 (3).
[0022]
Similarly, the rear-stage reduction unit set 23A (2) of the reduction gear 20 (2) is shared with the front-stage reduction unit set in the two- size reduction gear 20 (4). In other words, this means that the front-stage reduction unit set of the reduction gear 20 (4) is shared with the rear-stage reduction unit set of the reduction gear 20 (2) that is two sizes smaller.
[0023]
The rear-stage carrier 29 has a structure in which a pair of left and right carriers 8 and 9 as shown in FIG. In addition to this, the carrier 29 and the output shaft 34 integrated as described above are manufactured as one member. The plurality of planetary shafts 30 are driven pins, and are driven and fixed between carrier portions 28A and 28B located on the left and right sides with the inner teeth 24 therebetween.
[0024]
Further, in the fastening body in which the rear stage pinion shaft 32 is fastened to the front stage side carrier 37, the shaft end of the fastening body, that is, the shaft end 32a of the pinion shaft 32 is supported by a steel ball. In the illustrated example, a groove 29b is dug in the direction of the axis 20a on the annular end surface 29a of the carrier 29 facing the shaft end 32a of the pinion shaft 32, and a steel ball 29c is attached thereto. And the groove | channel provided with the conical inner peripheral surface 32b contact | abutted to the surface of the steel ball 29c is formed in the shaft end 32a side of a pinion shaft. Thus, the shaft end 32a side of the pinion shaft 32 is supported by the steel ball 29c.
[0025]
On the other hand, in the two-stage planetary gear speed reducer 20, a preload is applied to one main bearing 27 as follows. That is, the retaining ring 41 is disposed on the annular end surface of the inner ring 27 a of the main bearing 27. The retaining ring 41 is a flat annular end surface on the end surface that is in contact with the inner ring 27a. However, an annular inclined surface is formed on the inner peripheral side portion of the opposite annular end surface.
[0026]
A retaining ring groove 42 into which the retaining ring 41 is fitted is formed on the outer peripheral surface of the rear carrier 29. An annular inclined surface corresponding to the annular inclined surface of the retaining ring 41 is formed in the retaining ring groove 42. When the retaining ring 41 is expanded and mounted in the retaining ring groove 42, the retaining ring 41 is elastically returned toward the inner side in the radial direction. When this elastic restoring force is generated, a pressing force that presses the inner ring 27a in the axial direction is generated due to the wedge effect between the inclined surfaces.
[0027]
【The invention's effect】
As described above, in the two-stage planetary gear speed reducer of the present invention, the front internal gear of the front planetary gear mechanism and the rear internal gear of the rear planetary gear mechanism are ring-shaped gears, and the number of teeth Are the same. In addition, the front stage reduction gear set including the front stage internal gear, the front stage planetary shaft, the front stage planetary bearing, and the front stage planetary gear constituting the front stage planetary gear mechanism has the same size smaller than that of the two stage type planetary gear speed reducer. It is used in common with a rear speed reduction unit set incorporated in a two-stage planetary gear speed reducer having a structure. Alternatively, the rear stage reduction gear set including the rear stage internal gear, the rear stage planetary shaft, the rear stage planetary bearing, and the rear stage planetary gear constituting the rear stage planetary gear mechanism has the same structure having a size larger than that of the two-stage planetary gear speed reducer. The two-stage planetary gear reducer is used in common with the preceding stage reduction unit set.
[0028]
Therefore, when a series of two-stage planetary gear reducers having the same structure with different size / speed ratios is manufactured by the two-stage planetary gear reducer of the present invention configured as described above, the model number (size) / speed It is possible to make the parts common to the ratio. As a result, the total production number (product mix) of the two-stage planetary gear reducers of each size and each speed ratio for each size in the unit production period is the same as the conventional two-stage planetary gear reducer series. even, front deceleration portion set near the minimum size of the series, and except for the rear stage speed reducer set near the maximum size, throughout the series, since these deceleration portion set is used at least twice, the production of parts substantially The production volume can be almost doubled. Thus, according to the present invention, it is possible to inexpensively manufacture a two-stage planetary gear device.
[Brief description of the drawings]
FIG. 1A is a schematic sectional view of a two-stage planetary gear reducer to which the present invention is applied, and FIG. 1B is an explanatory view schematically showing the arrangement of gears and the arrangement of main bearings.
FIG. 2A is an explanatory diagram showing hatched portions of a front speed reduction unit set and a rear speed reduction unit set of the speed reducer of FIG. 1, and FIG. 2B is an explanatory diagram showing sharing of the speed reduction unit set.
FIG. 3 is a schematic sectional view showing a two-stage planetary gear reducer.
[Explanation of symbols]
20 Two-stage planetary gear reducer 21 Device housing 22 Front-stage planetary gear mechanism 22A Front-stage reduction gear set 23 Rear-stage planetary gear mechanism 23A Rear-stage reduction gear set 24 Internal teeth 25 Rear-stage internal gears 26, 27 Main bearings 28A, 28B Carrier Portion 29 Rear stage carrier 30 Rear stage planetary gear 31 Rear stage planetary gear 32 Rear stage pinion shaft 33 Rear stage sun gear 34 Output shaft 35 Front stage internal gear 36 Front stage planetary gear 36A Front stage planetary bearing 37 Front stage carrier 37A Front stage planetary shaft 38 Input pinion shaft 39 Front stage sun gear

Claims

A series of two-stage planetary gear reducers consisting of a plurality of two-stage planetary gear reducers having the same structure and different sizes,
Each size two-stage planetary gear speed reducer is composed of a front planetary gear mechanism including a front- stage reduction gear set and a rear-stage planetary gear mechanism including a rear- stage reduction gear set ,
The rear planetary gear mechanism includes a rear internal gear, a rear carrier composed of first and second carrier pieces rotatably supported by a pair of main bearings disposed on both sides of the rear internal gear, and A plurality of rear planetary gears rotatably supported via a rear planetary bearing around a plurality of rear planetary shafts spanned between the first and second carrier pieces and meshing with the rear internal gear; A rear-stage sun gear that is formed on an outer periphery of a rear-stage pinion shaft that extends through the first carrier piece and extends in the apparatus axis direction, and is connected to the second-stage carrier gear. And an output shaft extending in the apparatus axial direction,
The front stage planetary gear mechanism includes a front stage internal gear connected to the first carrier piece, a front stage carrier connected to the rear stage pinion shaft, and a plurality of front stage planetary shafts fixed to the front stage carrier. A plurality of front planetary gears rotatably supported through planetary bearings and meshing with the front inner teeth, and formed on the outer periphery of the input pinion shaft arranged coaxially with the rear pinion shaft, A pre-stage sun gear meshing with the pre-stage planetary gear,
The rear internal gear is a ring-shaped gear having internal teeth formed on the inner peripheral surface, and is connected and fixed to a device housing. The front internal gear is also a ring gear having internal teeth formed on the inner peripheral surface. The second stage internal gear and the front stage internal gear have the same number of teeth, and are connected and fixed to the annular end surface of the first carrier piece.
The front stage reduction unit set includes the front stage internal gear, a front stage planetary shaft, a front stage planetary bearing, and a front stage planetary gear,
The rear stage reduction gear set consists of the rear stage internal gear, the rear stage planetary shaft, the rear stage planetary bearing, and the rear stage planetary gear.
The front stage reduction unit set incorporated in the first size two-stage planetary gear speed reducer is the rear stage reduction part set incorporated in the second size two-stage planetary gear speed reducer that is smaller than the first size. A series of two-stage planetary gear reducers characterized by being used in common.

In claim 1,
The rear-stage reduction unit set incorporated in the first-size two-stage planetary gear reducer is the front-stage reduction unit set incorporated in the third-size two-stage planetary gear reducer that is larger than the first size. A series of two-stage planetary gear reducers characterized by being used in common.