JPS62218088A - Joint drive for industrial robot - Google Patents
Joint drive for industrial robotInfo
- Publication number
- JPS62218088A JPS62218088A JP61061637A JP6163786A JPS62218088A JP S62218088 A JPS62218088 A JP S62218088A JP 61061637 A JP61061637 A JP 61061637A JP 6163786 A JP6163786 A JP 6163786A JP S62218088 A JPS62218088 A JP S62218088A
- Authority
- JP
- Japan
- Prior art keywords
- gear
- reducer
- electric motor
- reduction
- speed
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000003638 chemical reducing agent Substances 0.000 claims description 68
- 230000000052 comparative effect Effects 0.000 description 9
- 230000010355 oscillation Effects 0.000 description 9
- 238000010586 diagram Methods 0.000 description 7
- 230000001133 acceleration Effects 0.000 description 6
- 238000002474 experimental method Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 3
- 230000005284 excitation Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 230000007935 neutral effect Effects 0.000 description 3
- 239000006096 absorbing agent Substances 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- 101100361281 Caenorhabditis elegans rpm-1 gene Proteins 0.000 description 1
- 241001272720 Medialuna californiensis Species 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16H—GEARING
- F16H1/00—Toothed gearings for conveying rotary motion
- F16H1/28—Toothed gearings for conveying rotary motion with gears having orbital motion
- F16H1/32—Toothed gearings for conveying rotary motion with gears having orbital motion in which the central axis of the gearing lies inside the periphery of an orbital gear
- F16H2001/323—Toothed gearings for conveying rotary motion with gears having orbital motion in which the central axis of the gearing lies inside the periphery of an orbital gear comprising eccentric crankshafts driving or driven by a gearing
Landscapes
- Manipulator (AREA)
- Retarders (AREA)
Abstract
(57)【要約】本公報は電子出願前の出願データであるた
め要約のデータは記録されません。(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は産業ロボットの関節駆動装置、特にロボット駆
動系の共振振動の発生を防止するものに関する。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a joint drive device for an industrial robot, and particularly to one that prevents the occurrence of resonance vibrations in a robot drive system.
（従来の技術とその問題点）
産業ロボットにおいては、一般に、作業に適した出力ト
ルクを得るため、アーム等の関節部の駆動系には、高速
低トルクの電動サーボモータまたは電動パルスモータと
、この出力を低速高トルクに変換する減速装置とを用い
ている。(Conventional technology and its problems) In industrial robots, in order to obtain output torque suitable for the work, the drive system of joints such as arms is generally equipped with a high-speed, low-torque electric servo motor or electric pulse motor. A reduction gear is used to convert this output into low speed and high torque.
また、そのような減速装置は、例えば、減速比１／１２
０程度の大減速比を有していること、また、歯車間のガ
タ、すなわち、いわゆるハックラッシュが小さいこと、
さらに、慣性を小さくするため軽量であること等が要求
される。Further, such a speed reduction device has a speed reduction ratio of 1/12, for example.
It has a large reduction ratio of about 0, and the backlash between gears, that is, the so-called hacklash, is small.
Furthermore, it is required to be lightweight in order to reduce inertia.
このような要求を満たす従来の減速装置としては、例え
ば、特開昭５９−１７５９８６号公報に開示されている
ような調和歯車装置（商品名：ハーモニノクドライブ）
および特開昭５９−１０６７４４号公報に開示されてい
るような偏心揺動型の遊星歯車減速機がある。前者の減
速比は一般に１／８０〜１ ／３２０程度であり、後者
の減速比は一般に１／６〜１ ／２００程度である。ま
た、前者は後者に比し減速比当りの外径、重量が小さく
、かつ、はとんどのロボットアームの関節部の駆動用減
速装置として必要な減速比および機械的強度を満足して
いる。したがって、ロボットアームの関節部駆動用減速
機のほとんどは調和歯車装置単体が適用され、まれに、
調和歯車装置でも得られないほどの大減速比を必要とす
るもの、すなわち、小容量高速回転（例えば、出力が１
０００ワツト以下で回転数が５０００ｒｐｍ）型のモー
タをロボットアームの駆動に用いる場合のように１ ／
６２５程度の減速比を必要とするもの、については特開
昭５６−１５２５９４号公転に開示されているように調
和歯車装置に前段減速装置を結合したものが用いられて
いる。As a conventional speed reduction device that satisfies such requirements, for example, a harmonic gear device (product name: Harmoninoku Drive) as disclosed in Japanese Patent Application Laid-open No. 175986/1986 is available.
There is also an eccentric oscillation type planetary gear reducer as disclosed in Japanese Patent Application Laid-Open No. 59-106744. The reduction ratio of the former is generally about 1/80 to 1/320, and the reduction ratio of the latter is generally about 1/6 to 1/200. Furthermore, the former has a smaller outer diameter and weight per reduction ratio than the latter, and satisfies the reduction ratio and mechanical strength required as a reduction gear for driving the joints of most robot arms. Therefore, most reduction gears for driving the joints of robot arms use a single harmonic gear device, and in rare cases,
Items that require a large reduction ratio that cannot be obtained even with harmonic gearing, i.e., small capacity, high speed rotation (for example, output of 1
1 / 2,000 watts or less and a rotation speed of 5,000 rpm) type motor is used to drive a robot arm.
For those requiring a speed reduction ratio of about 625, a harmonic gear system coupled to a pre-stage speed reduction system is used, as disclosed in Japanese Patent Laid-Open Publication No. 152594/1983.
しかしながら、上述した各減速装置をロボットの関節装
置に用いた場合、減速装置に入力する電動モータ回転数
が低い領域で減速装置とロボットアーム等とがねじり共
振を起こすという問題点があった。共振現象としては、
ロボットアームの関節部近傍にねじり振動が現れること
が多く、その結果、ロボットアームの先端位置が定まら
なくなる。共振が生じる理由は、電動モータのトルク伝
達機構である上記各減速装置の剛性が低いため、そのよ
うな減速装置を含む駆動系（電動モータ、減速装置およ
びロボットアームから構成される系）の固有ねじり振動
数ｆＯが一般に数ヘルツ（Ｈｚ）と低くなり、したがっ
て、歯切の加工誤差等に起因して振動する減速装置の振
動周波数が、電動モータの低回転数域で上記固有ねじり
振動数ｆＯと一致するためと考えられていた。However, when each of the above-mentioned speed reducers is used as a joint device of a robot, there is a problem that the speed reducer and the robot arm etc. cause torsional resonance in a region where the rotational speed of the electric motor input to the speed reducer is low. As a resonance phenomenon,
Torsional vibrations often appear near the joints of a robot arm, and as a result, the position of the tip of the robot arm becomes unstable. The reason why resonance occurs is that the rigidity of each of the reduction gears mentioned above, which is the torque transmission mechanism of the electric motor, is low. The torsional frequency fO is generally as low as several hertz (Hz), and therefore, the vibration frequency of the reduction gear, which vibrates due to machining errors in gear cutting, is lower than the above-mentioned natural torsional frequency fO in the low rotational speed range of the electric motor. It was thought that this would match the
このような問題点に対し、特開昭５８−２１１８８１号
公報には、発生した振動を打ち消すように電動モータの
速度指令信号を変化させる電気的制御方式が提案されて
いる。しかしながら、このような方式においてはフィー
ドバンクゲインを大きくすると系が不安定となり、特に
剛性の低いロボット駆動系においては、逆に発振し易く
なるという問題を生じるため、ゲインを大きくできず、
したがって、充分な振動打ち消し効果を得られない。ま
た、特開昭５９−１７５９８６号公報には高張力を与え
たタイミングベルトで減速機を駆動し、該ベルトで振動
を吸収する方式のものが提案されている。しかしながら
、この方式においてはタイミングベルトが破断するとい
う危険がある。To address these problems, Japanese Patent Laid-Open No. 58-211881 proposes an electrical control method that changes the speed command signal of the electric motor so as to cancel out the generated vibrations. However, in this type of system, increasing the feed bank gain makes the system unstable, and conversely causes the problem of oscillation, especially in robot drive systems with low rigidity, so it is not possible to increase the gain.
Therefore, a sufficient vibration canceling effect cannot be obtained. Further, Japanese Patent Application Laid-Open No. 59-175986 proposes a system in which a reduction gear is driven by a timing belt with high tension and vibrations are absorbed by the belt. However, in this method there is a risk that the timing belt will break.
また、特開昭５９−１１５１８９号公報には減速機の主
軸にばねとおもりから成る吸振器を取り付ける方式が提
案されている。しかし、この方式においては遠心力によ
り吸振器が破損したり、ロボットの負荷荷重に対応して
おもり等を調整しなければならないという問題点がある
。さらに、これらのものは、複雑になり、部品数も多く
なるという問題点がある。Furthermore, Japanese Patent Application Laid-Open No. 59-115189 proposes a system in which a vibration absorber consisting of a spring and a weight is attached to the main shaft of a speed reducer. However, this method has problems such as damage to the vibration absorber due to centrifugal force and the need to adjust weights and the like according to the load applied to the robot. Furthermore, these devices have the problem of being complicated and having a large number of parts.
（発明の目的）
そこで、本発明は、共振現象を実用域から外す共振防止
構造にするとともに、その構造を簡単にしたロボットの
関節駆動装置を提供することを目的とする。(Objective of the Invention) Therefore, an object of the present invention is to provide a robot joint drive device that has a resonance prevention structure that removes the resonance phenomenon from the practical range and has a simplified structure.
（発明の構成）
発明者らは、ロボットアームの関節駆動装置に用いる減
速機のばね定数、固有ねじり振動数、トルク変動等と共
振現象との関係につき種々研究を行った。(Structure of the Invention) The inventors conducted various studies on the relationship between the resonance phenomenon and the spring constant, natural torsional frequency, torque fluctuation, etc. of the reducer used in the joint drive device of the robot arm.
先ず、中立位置付近くいわゆるロストモーション位置）
の回転ばね定数ＫＮ（第７図参照）の高い減速機をロボ
ットアームの関節駆動装置に用いることによりロボット
の駆動系の固有ねじり振動数ｆｏを実用域から外すこと
が可能か否かについて試算した。しかし、減速機の中立
位置付近の回転ばね定数に１は、大きなものでもロボッ
トアーム自体の回転ばね定数Ｋｒの１／１０〜１１５で
あるため、駆動系全体のばね定数に＝ＫＩ！・Ｋｒ／（
Ｋｊｌ！＋Ｋｒ）は大して太き（できず、その結果、駆
動系の固有ねじり振動数ｆｏ＝１／２π・ｈでアコ７（
ここに、Ｊは駆動系の慣性モーメント）も大して大きく
できない。したがって、減速機の中立位置付近のばね定
数ＫＪを高めること、すなわち剛性を高めることによっ
ては、駆動系の固有ねしり振動数ｒＯを実用域から外す
ことは不可能であるとの結論に達した。First, near the neutral position (so-called lost motion position)
A trial calculation was made to determine whether it is possible to remove the natural torsional frequency fo of the robot drive system from the practical range by using a reducer with a high rotational spring constant KN (see Figure 7) in the joint drive device of the robot arm. . However, the rotational spring constant of 1 near the neutral position of the reducer is 1/10 to 115 of the rotational spring constant Kr of the robot arm itself, even if it is large, so the spring constant of the entire drive system is = KI!・Kr/(
Kjl! +Kr) is very thick (cannot be done, and as a result, the drive system's natural torsional frequency fo = 1/2π・h is Ako7(
Here, J is the moment of inertia of the drive system) and cannot be made very large. Therefore, we came to the conclusion that it is impossible to remove the drive system's natural torsion frequency rO from the practical range by increasing the spring constant KJ near the neutral position of the reducer, that is, by increasing its rigidity. .
そこで、発明者等は、振動発生の原因である減速機のト
ルク変動を無くすことを試みた。具体的には偏心揺動型
の遊星歯車減速機を用い、トルク変動を阻止ないし減す
るよう、この減速機の内歯歯車と外歯歯車の歯に高精度
の仕上げ加工を施し、かつ、トルク変動が生してもこれ
を吸収するよう、偏心入力軸の軸受部やトルク取出ピン
の軸支部等に環状溝を設け、該溝にゴムリングを装着し
た。Therefore, the inventors attempted to eliminate torque fluctuations in the reducer, which are the cause of vibrations. Specifically, an eccentric oscillating planetary gear reducer is used, and the teeth of the internal gear and external gear of this reducer are finished with high precision to prevent or reduce torque fluctuations. In order to absorb any fluctuations that may occur, an annular groove was provided in the bearing part of the eccentric input shaft, the shaft support of the torque take-off pin, etc., and a rubber ring was attached to the groove.
巳かしながら、このような対策を施しても実用域での共
振を防ぐことはできず、しかも、共振が生じる時の電動
モータ回転数は、そのような対策を施さない場合とほと
んど同じであることがわがった。However, even with such countermeasures, it is not possible to prevent resonance in practical applications, and furthermore, the electric motor rotation speed when resonance occurs is almost the same as without such countermeasures. I realized something.
このような実験結果から、一定の機構の減速機であれば
、はぼ一定のトルク変動特性、すなわちロボットの駆動
系に対する加振周波数特性を有するとの結論が導かれた
。また、斯かる結論から、ロボット駆動系に組み込む減
速装置の機構を変更することによりトルク変動特性を実
用域外に置くことができるとの仮説の下に種々の実験を
行った。These experimental results led to the conclusion that a reduction gear with a fixed mechanism has approximately constant torque fluctuation characteristics, that is, excitation frequency characteristics for the robot drive system. In addition, based on this conclusion, various experiments were conducted under the hypothesis that the torque fluctuation characteristics could be brought out of the practical range by changing the mechanism of the reduction gear incorporated in the robot drive system.
これらの実験の内容および結果については後述するが、
これらの実験結果から仮説は実証され、下記の結論に到
達した。The content and results of these experiments will be discussed later, but
The hypothesis was verified from these experimental results, and the following conclusions were reached.
従来の常識では全く考えられなかった構成、すなわち、
偏心揺動型の遊星歯車減速機は、内歯歯車と外歯歯車の
歯数差が１であって、単独でもｌ／２００程度の減速比
にできるが、この減速比を数十分の一程度とし、これに
所定範囲の減速比を有する前段減速比をわざわざ設けて
歯車装置を構成し、これをロボットアームの駆動系に組
み込むという構成により共振現象の生じる範囲を電動モ
ータの実用域から外すことができる。A configuration that was completely unthinkable according to conventional common sense, that is,
In an eccentric oscillating planetary gear reducer, the difference in the number of teeth between the internal gear and the external gear is 1, and even when used alone, it can achieve a reduction ratio of about 1/200, but this reduction ratio can be reduced to a few tenths of a second. By constructing a gear device by intentionally providing a pre-stage reduction ratio with a reduction ratio within a predetermined range, and incorporating this into the drive system of the robot arm, the range in which resonance occurs is removed from the practical range of electric motors. be able to.
なお、偏心揺動型の遊星歯車減速機に前段減速機を設け
た減速装置は、米国特許第４．３４８．９１８号明細書
に開示されているようにクローラ車両の走行装置等に採
用されている。しかしながら、そのような走行装置等は
採用する減速機の重量、バックラソシ等の問題をほとん
ど考慮しなくともよい。Incidentally, a reduction gear in which an eccentric oscillating planetary gear reduction gear is provided with a front stage reduction gear has been adopted in a crawler vehicle traveling device, etc., as disclosed in U.S. Pat. No. 4.348.918. There is. However, in such a traveling device, there is little need to consider problems such as the weight of the reducer used and backlash.
したがって、単に減速機の終減速比の変更を容易にする
ため、あるいは単に低速大トルクを出力するため、前段
減速機を設けているのである。これに対し、高速性、位
置精度等を要求され、且つ、全体構造の剛性が低いロボ
ットにおいては、減速機の重量、バンクラッシュを小さ
くすることが重要であるため、関節部に、減速辻占たり
の重量が調和歯車装置より大きい偏心揺動型の遊星歯車
減速機を用い、さらに重量、バックランシュを増大させ
る要素となる前段減速機をわざわざ設けることは従来考
えられなかったのである。Therefore, the pre-stage reduction gear is provided simply to facilitate changing the final reduction ratio of the reduction gear, or simply to output low-speed large torque. On the other hand, in robots that require high speed, positional accuracy, etc. and have low rigidity of the overall structure, it is important to reduce the weight of the reducer and reduce bank lash. Conventionally, it was unthinkable to use an eccentric oscillation type planetary gear reducer whose weight is larger than that of a harmonic gear unit, and to take the trouble to provide a pre-stage reducer which would further increase the weight and backlash.
発明者らはさらに種々研究を重ねた結果、下記の構成を
有する本発明に到達した。As a result of further various studies, the inventors have arrived at the present invention having the following configuration.
本発明に係る産業ロボットの関ｆｌｆｆ駆動装置は、ロ
ボットの第１部材と、第１部材に回動自在に支持された
ロボットの第２部材と、第１部材に一体的に取り付けら
れた電動モータの回転を減速して第２部材に伝達する歯
車減速装置と、を備えた産業ロボットの関節駆動装置に
おいて、前記歯車減速装置が、前記電動モータの回転数
を減速する前段減速機と、前段減速機の出力の回転数を
更に減速して前記第２部材に出力する後段の遊星歯車減
速機と、から構成され、前記遊星歯車減速機が、複数の
偏心入力軸を円周上に等配支持したフランジ、前記各偏
心入力軸と係合しその回転により偏心揺動させられる外
歯歯車および外歯歯車と噛み合い外歯歯車の歯数より１
つ多い歯数を有する内歯歯車を存し、前記前段減速機が
前記電動モータの出力軸に取着された入力歯車および前
記各偏心入力軸に取着された出力歯車を有する平行軸減
速機に構成され、前記遊星歯車減速機の減速比を１／１
５〜１／６０とし、かつ前記歯車減速装置全体の減速比
を１／４０〜１ ／３２０としたことを特徴としている
。The industrial robot GFF drive device according to the present invention includes a first member of the robot, a second member of the robot rotatably supported by the first member, and an electric motor integrally attached to the first member. A joint drive device for an industrial robot comprising: a gear reduction device that reduces the rotation speed of the electric motor and transmits the rotation speed to a second member; a planetary gear reducer at a later stage that further reduces the rotational speed of the output of the machine and outputs it to the second member, and the planetary gear reducer supports a plurality of eccentric input shafts at equal intervals on the circumference. 1 from the number of teeth of the external gear that meshes with the external gear and the external gear that engages with each of the eccentric input shafts and is eccentrically oscillated by the rotation of the external gear.
A parallel shaft reduction gear comprising an internal gear having a large number of teeth, wherein the pre-stage reduction gear has an input gear attached to the output shaft of the electric motor and an output gear attached to each of the eccentric input shafts. The reduction ratio of the planetary gear reducer is set to 1/1.
5 to 1/60, and the reduction ratio of the entire gear reduction device is 1/40 to 1/320.
（実施例）
以下、本発明に係る産業ロボットの関節駆動装置を図面
に基づいて説明する。第１図ないし第３図は本発明の第
１実施例を示す図である。(Example) Hereinafter, a joint drive device for an industrial robot according to the present invention will be explained based on the drawings. 1 to 3 are diagrams showing a first embodiment of the present invention.
まず、構成について説明する。第１図は本発明に係る産
業ロボットの関節駆動装置を用いたロボットの関節部の
全体概略図である。１は電動モータであり、電動モータ
１のフランジ２は減速装置３の筒体４に固定されている
。筒体４は第１部材としての第１アーム５の先端部５ａ
に固定されている。電動モータ１の出力の回転軸７は減
速装置３の入力回転軸８ （第２図）に連結され、減速
装置３の出力は軸１０に伝達され、軸１０は円筒体１１
を貫通して第２部材としての第２アーム１２に固定され
ている。第２アーム１２の端部の筒状体１３と第１アー
ム５の先端部５ａの下面から下方に突出する円筒型の突
出体１５との間には一対のベアリング１６が介装され、
第２アーム１２は第１アーム５に回動自在に支持されて
いる。突出体１５の内周面と円筒体１１の中央部の外周
面との間には一対のベアリング１７が介装されている。First, the configuration will be explained. FIG. 1 is an overall schematic diagram of a joint portion of a robot using a joint drive device for an industrial robot according to the present invention. 1 is an electric motor, and a flange 2 of the electric motor 1 is fixed to a cylindrical body 4 of a reduction gear device 3. The cylindrical body 4 is a distal end portion 5a of a first arm 5 as a first member.
Fixed. The output rotation shaft 7 of the electric motor 1 is connected to the input rotation shaft 8 (FIG. 2) of the reduction gear 3, and the output of the reduction gear 3 is transmitted to the shaft 10, which is connected to the cylindrical body 11.
It penetrates through and is fixed to the second arm 12 as a second member. A pair of bearings 16 are interposed between the cylindrical body 13 at the end of the second arm 12 and a cylindrical protrusion 15 that protrudes downward from the lower surface of the tip 5a of the first arm 5.
The second arm 12 is rotatably supported by the first arm 5. A pair of bearings 17 are interposed between the inner peripheral surface of the protruding body 15 and the outer peripheral surface of the central portion of the cylindrical body 11.
円筒体１１の上部および下部の内面と軸１０との間には
それぞれ一対のヘアリング１８が介装されている。した
がって、減速装置３は電動モータ１の回転数を減速して
ロボットの被駆動部すなわち第２アーム１２を回動させ
る。また、電動モータ１、減速装置３、第２アーム１２
および第２アームに接続された負荷は駆動系を構成する
。A pair of hair rings 18 are interposed between the upper and lower inner surfaces of the cylindrical body 11 and the shaft 10, respectively. Therefore, the speed reducer 3 reduces the rotational speed of the electric motor 1 to rotate the driven portion of the robot, that is, the second arm 12. In addition, an electric motor 1, a reduction gear 3, a second arm 12
The load connected to the second arm constitutes a drive system.
減速装置３は第２図および第３図に示すように、電動モ
ータ１の回転数を減速する前段減速機２０と、前段減速
機２０に連結され、回転数をさらに減速する後段減速機
２１と、から構成されている。前段減速機２０は通常の
平行軸型減速機であり、平歯歯車により構成されている
。As shown in FIGS. 2 and 3, the speed reducer 3 includes a first stage reducer 20 that reduces the rotation speed of the electric motor 1, and a second stage speed reducer 21 that is connected to the first stage speed reducer 20 and further reduces the rotation speed. , is composed of. The front speed reducer 20 is a normal parallel shaft type speed reducer, and is composed of spur gears.
電動モータ１の回転軸７の先端部７ａはテーパ軸であり
、先端にねじ７ｂを有する。ねじ部７ｂにはモータ出力
軸の一部を構成する連絡軸７Ｃが螺合されている。８は
入力回転軸であり、先端部８ａに前段減速機２０のピニ
オン２２が設けられると共にモータ回転軸７を貫通させ
る孔８ｂを有し、且つ孔８ｂは回転軸７のテーパ部と係
合するテーバ孔部を存する。人力回転軸８は電動モータ
１の回転軸７の先端部７ａにナツト２３によりねじ止め
される。回転軸７の先端部７ａは入力回転軸８に半月キ
ー２４により固定されている。このような構成により入
力回転軸８の先端部８ａの軸径はモータ回転軸７の軸径
より小さくすることができ、したがって、ピニオン２２
の歯数はモータ回転軸７に歯車を直接装着させる場合に
比べ、少なくすることができ、容量の割に回転軸径の大
きい市販電動モータ１を用いる場合であっても、所定の
前段減速比を得ることができる。ピニオン２２に噛み合
う３個の平歯車２５は、後述する３本の入力クランク軸
３０にそれぞれ結合している。The tip 7a of the rotating shaft 7 of the electric motor 1 is a tapered shaft, and has a screw 7b at the tip. A communication shaft 7C, which constitutes a part of the motor output shaft, is screwed into the threaded portion 7b. Reference numeral 8 designates an input rotation shaft, which has a pinion 22 of the pre-stage reducer 20 at its tip 8a and has a hole 8b through which the motor rotation shaft 7 passes, and the hole 8b engages with a tapered portion of the rotation shaft 7. There is a taber hole. The manual rotation shaft 8 is screwed to the tip 7a of the rotation shaft 7 of the electric motor 1 with a nut 23. The tip 7a of the rotating shaft 7 is fixed to the input rotating shaft 8 with a half-moon key 24. With such a configuration, the shaft diameter of the tip end 8a of the input rotation shaft 8 can be made smaller than the shaft diameter of the motor rotation shaft 7, so that the pinion 22
The number of teeth can be reduced compared to the case where gears are directly attached to the motor rotation shaft 7, and even when using a commercially available electric motor 1 with a large rotation shaft diameter relative to its capacity, the predetermined pre-stage reduction ratio can be reduced. can be obtained. Three spur gears 25 that mesh with the pinion 22 are respectively coupled to three input crankshafts 30, which will be described later.
遊星歯車減速機２１は筒体４に固定して設けられた内歯
歯車２８と、内歯歯車２８に噛み合う一対の外歯歯車２
９と、外歯歯車２９に係合して外歯歯車２９を揺動回転
させる偏心入力軸としての３本の入力クランク軸３０と
、から構成されている。また、内歯歯車２８はピン歯３
１を用いたビン歯車で構成され、かつ外歯歯車２９の歯
数より１つだけ多い歯数を有している。３３は円板状の
フランジであり、フランジ３３は遊星歯車減速機２１の
前端部を構成し、かつ、入力クランク軸３０を円周上に
等配しベアリング３４を介して軸支している。３５はブ
ロック体であり、ブロック体３５はその中心部に軸方向
の円筒状孔３７を有し、入力回転軸８が遊嵌されている
。同様に外歯歯車２９およびフランジ３３の中心部にも
孔が設けられている。ブロック体３５はその後端部に凹
み３６を設けたフランジ部３５ａを有し、軸ＩＯのフラ
ンジ部ｔＯａに対向している。凹み３６とフランジ部３
９とによって形成された空洞内には、前段減速機２０が
収納されている。ブロック体３５のフランジ部３５ａに
は入力クランク軸３０を円周上に等配しベアリング４１
を介して軸支している。入力クランク軸３０の延在部３
０ａは凹み３６内に突出し、平歯車２５に固定されてい
る。The planetary gear reducer 21 includes an internal gear 28 fixed to the cylinder 4 and a pair of external gears 2 meshing with the internal gear 28.
9, and three input crankshafts 30 as eccentric input shafts that engage with the external gear 29 and swing and rotate the external gear 29. Further, the internal gear 28 has pin teeth 3
1, and has one more tooth than the external gear 29. Reference numeral 33 denotes a disc-shaped flange, which constitutes the front end of the planetary gear reducer 21 and supports the input crankshaft 30 evenly distributed on the circumference via bearings 34. 35 is a block body, and the block body 35 has an axial cylindrical hole 37 in its center, into which the input rotating shaft 8 is loosely fitted. Similarly, holes are provided in the centers of the external gear 29 and the flange 33. The block body 35 has a flange portion 35a provided with a recess 36 at its rear end, and faces the flange portion tOa of the shaft IO. Recess 36 and flange part 3
A pre-stage reduction gear 20 is housed in the cavity formed by 9 and 9. The input crankshaft 30 is equally distributed on the circumference of the flange portion 35a of the block body 35, and bearings 41
It is pivoted through. Extension part 3 of input crankshaft 30
0a protrudes into the recess 36 and is fixed to the spur gear 25.
入力クランク軸３０は円板部３３とブロック体３５の中
央部に軸支され、入力クランク軸３０の中央には１８０
°の位相差をもつ一対のクランク部４２を有し、各クラ
ンク部４２はヘアリング４３を介して外歯歯車２９を偏
心揺動させるようにしている。ここで、前述したフラン
ジ３３と、ブロック体３５とは支持体４４を構成する。The input crankshaft 30 is pivotally supported at the center of the disk portion 33 and the block body 35.
It has a pair of crank parts 42 having a phase difference of .degree., and each crank part 42 causes the external gear 29 to swing eccentrically through a hair ring 43. Here, the flange 33 and the block body 35 described above constitute a support body 44.
フランジ３３、ブロック体３５およびフランジ部１０ａ
は複数のポルト４６および固定ナツト４７により同時に
一体的に固定されている。Flange 33, block body 35 and flange portion 10a
are simultaneously and integrally fixed by a plurality of ports 46 and fixing nuts 47.
電動モータｌの回転は回転軸７および入力軸８を介して
前段減速機２０のビニオン２２に伝達され、前段減速機
２０で減速される。前段減速機２０の出力は平歯車２５
により遊星歯車減速機２１のクランク軸３０に入力され
る。次いで、クランク軸３０の回転により偏心揺動させ
られる外歯歯車２９と、この外歯歯車２９と噛み合い外
歯歯車２９より１つ多い歯数を有する内歯歯車２８とに
よりさらに減速され、外歯歯車２９のゆっくりした自転
運動はキャリアとして作用する支持体４４から軸１０に
伝達されアーム１２が回動される。The rotation of the electric motor I is transmitted to the binion 22 of the front speed reducer 20 via the rotation shaft 7 and the input shaft 8, and is decelerated by the front speed reducer 20. The output of the front stage reducer 20 is the spur gear 25
is input to the crankshaft 30 of the planetary gear reducer 21. Next, the external gear 29 is eccentrically oscillated by the rotation of the crankshaft 30, and the internal gear 28 meshes with the external gear 29 and has one more tooth than the external gear 29. The slow rotational motion of the gear 29 is transmitted from the support 44 acting as a carrier to the shaft 10, and the arm 12 is rotated.
本実施例においては、電動モータ１の通常制御回転数は
Ｏ〜１１０００ｒｐ 、前段減速機２０の減速比ｉ、は
１／３、遊星歯車減速機２１の減速比１２は１／４０．
減速装置３の終域速比ｉは１／１２０、電動モータ１、
減速装置３および第２７−ム１２を含んで構成される駆
動系の固有ねじり振動数ｒ０は約８．４ヘルツである。In this embodiment, the normal control rotational speed of the electric motor 1 is 0 to 11000 rpm, the reduction ratio i of the front stage reduction gear 20 is 1/3, and the reduction ratio 12 of the planetary gear reduction gear 21 is 1/40.
The final speed ratio i of the reduction gear 3 is 1/120, the electric motor 1,
The natural torsional frequency r0 of the drive system including the speed reducer 3 and the 27th arm 12 is approximately 8.4 hertz.
したがって、電動モータ１は産業ロボットの駆動系の固
有ねじり振動数に対応する回転数（８，４ヘルツに相当
する５００ｒｐｍ）を通常制御域（０〜１１０００ｒｐ
）内に有している。また、前段減速機２０は電動モー
タ１の通常制御域における毎秒最高回転数（１１０００
ｒｐに相当する毎秒１６．７回転）を、駆動系の固有ね
じり振動数ｆＯ以下になるよう（毎秒５．６回転）に減
速する減速比１１（１／３）を有している。Therefore, the electric motor 1 has a rotation speed (500 rpm corresponding to 8.4 Hz) corresponding to the natural torsional frequency of the drive system of the industrial robot in the normal control range (0 to 11000 rpm).
). In addition, the pre-stage reducer 20 operates at the maximum rotation speed (11,000 rotations per second) in the normal control range of the electric motor 1.
It has a reduction ratio of 11 (1/3) that reduces the rotation speed (16.7 rotations per second corresponding to rp) to below the natural torsional frequency fO of the drive system (5.6 rotations per second).
減速機４０（７）回転ばね定数に、は約３７．５ｋｇ−
ｍ ／分である。The rotational spring constant of reducer 40 (7) is approximately 37.5 kg-
m/min.
次に、作用について説明する。Next, the effect will be explained.
電動モータ１を０〜１１０００ｒｐの通常回転数で回転
させると、減速比１１が１７３の前段減速機２０の出力
回転数はＯ〜３３３ｒｐｍとなり、減速比１２が１／４
０の後段減速機２１の出力回転数はＯ〜８．’３ｒｐｍ
となり、この範囲では共振現象が生じない。共振は実用
域外、すなわち電動モータ１の出力回転数が１５００ｒ
ｐｍ近辺（このときの前段減速機２０の出力回転数は１
５００ｒｐｍ Ｘ １ ／ ３ ＝５０Ｏｒｐｍ近辺、
遊星歯車減速機２１の出力回転数は１５００ｒｐｍ Ｘ
１ ／ ３ Ｘｌ ／ ４０ ＝ １２．５ｒｐｍ近
辺）で生じる。このように共振現象が電動モータ１の実
用域外で生じる理由は明らかではないが、実験結果から
推定すると上記実施例のように内歯歯車と外歯歯車の歯
数差が１の遊星差動歯車装置は入力軸（クランク軸３０
）の１回転当たり１のトルク変動が生じ、したがって、
これに減速比１１が１／３の前段減速機２０を取り付け
ると電動モータ１の回転ｉが実用域外である１５００ｒ
ｐｍを中心とした付近で１５００Ｘ （１／３） Ｘ１
＝５００程度の毎分当たりトルク変動が生じ、このトル
ク変動数が駆動系の固有振動数８４４ヘルツ（５００振
動／分）にほぼ一致して共振を起こすものと考えられる
。When the electric motor 1 is rotated at a normal rotation speed of 0 to 11000 rpm, the output rotation speed of the front stage reducer 20 with a reduction ratio 11 of 173 is 0 to 333 rpm, and the reduction ratio 12 is 1/4.
The output rotation speed of the rear stage reducer 21 is 0 to 8. '3rpm
Therefore, within this range, no resonance phenomenon occurs. Resonance is outside the practical range, that is, the output rotation speed of electric motor 1 is 1500 r.
around pm (at this time, the output rotation speed of the front stage reducer 20 is 1
500 rpm X 1/3 = around 50 Orpm,
The output rotation speed of the planetary gear reducer 21 is 1500 rpm
1/3 Xl/40 = around 12.5 rpm). Although it is not clear why the resonance phenomenon occurs outside the practical range of the electric motor 1, it is estimated from the experimental results that the planetary differential gear in which the difference in the number of teeth between the internal gear and the external gear is 1 as in the above embodiment The device is an input shaft (crankshaft 30
) results in a torque variation of 1 per revolution, thus:
When a pre-stage reducer 20 with a reduction ratio 11 of 1/3 is attached to this, the rotation i of the electric motor 1 is 1500 r, which is outside the practical range.
1500X (1/3) X1 around pm
It is thought that a torque fluctuation of approximately 500 vibrations per minute occurs, and this torque fluctuation frequency approximately matches the natural frequency of 844 hertz (500 vibrations/minute) of the drive system, causing resonance.
これに対し、内歯と外歯の歯数差が２の調和歯車装置の
場合は、実験結果から推定すると、入力軸（ウェーブジ
ェネレータ）の１回転当たり２のトルク変動が生じ、し
たがって、これに減速比１／３の前段減速機を取り付け
ると、電動モータの回転数が７５０ｒｐｍ付近で７５０
ｘ １ ／ ３ ｘ ２ ＝５００の毎分当たりトル
ク変動が生じ、駆動系の固有振動数ｆｏが上記実施例と
同様８．４ヘルツ（５００振動／毎分）であるならば電
動モータの回転数が実用域内である７５０ｒｐｍ付近で
共振が生じるものと考えられる。この場合、毎分当たり
加振数がおおよそ５００のときに共振が生じるのである
から、調和歯車減速機に減速比ｉ、＝１／６程度の前段
減速機を設けることにより共振時の電動モータの回転数
を実用域外である１５００ｒｐｍを中心とする付近にま
で上げることも考えられる。しかし、調和歯車減速機の
減速比１２は最小でも１／８０程であるから、終域速比
ｉは最小でも１ ／４８０となり、１〜１１０００ｒｐ
を実市域とする電動モータが一般に必要とする減速比ｉ
（１／１２０程度）を満足できないため、実用できない
ことになる。On the other hand, in the case of a harmonic gear device in which the difference in the number of teeth between internal and external teeth is 2, it is estimated from the experimental results that a torque fluctuation of 2 occurs per revolution of the input shaft (wave generator), and therefore, When a front stage reducer with a reduction ratio of 1/3 is installed, the rotation speed of the electric motor will be 750 rpm at around 750 rpm.
If a torque fluctuation of x 1 / 3 x 2 = 500 per minute occurs and the natural frequency fo of the drive system is 8.4 hertz (500 vibrations/min) as in the above example, then the rotational speed of the electric motor is It is thought that resonance occurs around 750 rpm, which is within the practical range. In this case, resonance occurs when the number of excitations per minute is approximately 500, so by providing a front-stage reducer with a reduction ratio i, = 1/6, in the harmonic gear reducer, the electric motor at resonance can be It is also conceivable to increase the rotational speed to around 1500 rpm, which is outside the practical range. However, since the reduction ratio 12 of the harmonic gear reducer is at least about 1/80, the final speed ratio i is at least 1/480, which is 1 to 11000 rpm.
The reduction ratio i generally required for an electric motor with
(approximately 1/120), it cannot be put to practical use.
なお、電動モータ１および前段減速機２０の振動は駆動
系の発振に影響を及ぼさない。これは、これらの振動は
小さいこと、後段部２１を介することにより吸収される
こと等によるものと考えられる。Note that the vibrations of the electric motor 1 and the front speed reducer 20 do not affect the oscillation of the drive system. This is considered to be due to the fact that these vibrations are small and are absorbed through the rear stage section 21.
（実験例）
前述の実施例の減速装置のほかに次表の比較例１〜３に
示す減速装置について実施した振動測定試験について説
明する。比較例１．２の偏心揺動型の！星歯車減速機は
、クランク軸および外歯歯車の揺動によるアンバランス
を防いで振動の振幅を小さくするため、前述の実施例同
様に外歯歯車を２枚としこれらを１８０度の位相差をも
って組み付けたもので、かつ、内歯歯車が外歯歯車の歯
数より１つ多い歯数を有するものを用いた。また、調和
歯車減速機は内歯歯車が外歯歯車の歯数より２つ多い歯
数を有するものを用いた。それぞれの減速装置の減速段
数、減速比ｉ、、ｉ２、回転ばね定数に＋（第７図参照
）および慣性モーメントＪは次表に示しである。(Experimental Example) A vibration measurement test conducted on the speed reduction devices shown in Comparative Examples 1 to 3 in the following table in addition to the speed reduction devices of the above-mentioned examples will be described. Comparative Example 1.2 of the eccentric swing type! The star gear reducer has two external gears with a phase difference of 180 degrees, as in the previous embodiment, in order to prevent unbalance caused by the rocking of the crankshaft and external gears and reduce the amplitude of vibration. An assembled gear was used in which the internal gear had one more tooth than the external gear. Further, the harmonic gear reducer used has an internal gear having two more teeth than an external gear. The number of reduction stages, reduction ratio i, i2, rotational spring constant (see FIG. 7), and moment of inertia J of each reduction gear are shown in the following table.
（注１）：遊星歯車減速は偏心揺動型の遊星歯車減速機
を、平歯歯車減速は平行軸型の
平歯歯車列減速機を示す。(Note 1): Planetary gear reduction refers to an eccentric oscillation type planetary gear reduction gear, and spur gear reduction refers to a parallel shaft type spur gear train reduction gear.
実験は第５図に示す全体構成図によって実施した。すな
わち、電動サーボモータ５１の出力軸５１ａに減速装置
５２を取付け、減速装置５２の出力軸５２ａにロボット
の被駆動部（第２アーム）の慣性モーメントＪに相当す
る慣性負荷としてフライホイール５３が取付けられた。The experiment was conducted using the overall configuration diagram shown in FIG. That is, the reduction gear 52 is attached to the output shaft 51a of the electric servo motor 51, and the flywheel 53 is attached to the output shaft 52a of the reduction gear 52 as an inertial load corresponding to the moment of inertia J of the driven part (second arm) of the robot. It was done.
フライホイール側面５３ａの半径上の位置に、円周方向
の加速度および振幅を測定できる圧電素子を利用した加
速度ピンクアップ５４を取り付けた。この加速度ピック
アップ５４の出力はインジケータ５６に連結されている
。モータ５Ｌ Ｊ速装置５２およびフライホイール５３
から成る駆動系の固有振動数ｆ０は約８．４ヘルツにな
るよう調整しである。電動モータの回転数を変化させて
、その時のフライホイールの加速度の大きさを測定した
。測定結果は第４図に示す。横軸は電動サーボモータ５
１の回転数であり、縦軸は加速度ピックアップ５４で検
出された円周方向の加速度（単位二Ｇ）を示す。An acceleration pink-up 54 using a piezoelectric element capable of measuring acceleration and amplitude in the circumferential direction was attached to a position on the radius of the flywheel side surface 53a. The output of this acceleration pickup 54 is coupled to an indicator 56. Motor 5L J speed device 52 and flywheel 53
The natural frequency f0 of the drive system consisting of is adjusted to be about 8.4 hertz. The rotation speed of the electric motor was varied and the magnitude of the acceleration of the flywheel at that time was measured. The measurement results are shown in Figure 4. The horizontal axis is electric servo motor 5
1, and the vertical axis indicates acceleration in the circumferential direction (unit: 2 G) detected by the acceleration pickup 54.
比較例１、比較例２および比較例３においては、共振の
ピークはそれぞれ、電動モータ５１の回転数が、略７５
０ｒｐｍ、略５００ｒｐｍおよび略２５Ｏｒｐｍのとき
であり、電動モータ５１の通常制御回転数０〜１１００
０ｒｐの範囲で共振が起こっている。しかしながら、本
発明に係る減速装置を用いた実施例の場合には、電動モ
ータの実用域外である１５００ｒｐｍを中心とする近傍
で共振現象が生じる。In Comparative Example 1, Comparative Example 2, and Comparative Example 3, the resonance peak occurs when the rotational speed of the electric motor 51 is approximately 75.
0 rpm, approximately 500 rpm, and approximately 25 Orpm, and the normal control rotation speed of the electric motor 51 is 0 to 1100.
Resonance occurs in the 0rp range. However, in the case of the embodiment using the speed reduction device according to the present invention, a resonance phenomenon occurs around 1500 rpm, which is outside the practical range of the electric motor.
比較例２と比較例３の対比から、共振時における電動モ
ータ５１の回転数は内歯歯車と外歯歯車の歯数差が１の
遊星歯車減速機が歯数差２の調和歯車装置の２倍となる
ことが認められる。また、実施例、比較例１および比較
例２の対比から、共振時における電動モータ５１の回転
数は前段減速機の減速比１１に比例していることが認め
られる。From the comparison between Comparative Example 2 and Comparative Example 3, the rotational speed of the electric motor 51 during resonance is higher than that of the planetary gear reducer in which the difference in the number of teeth between the internal gear and the external gear is 1, compared to that of the harmonic gear device in which the difference in the number of teeth is 2. It is accepted that the amount will be doubled. Further, from the comparison between the example, comparative example 1, and comparative example 2, it is recognized that the rotational speed of the electric motor 51 during resonance is proportional to the reduction ratio 11 of the front speed reducer.
なお、このような実験結果から前述のように各減速機の
トルク変動特性が推定され、かかる推定を用いて実験装
置の固有ねじり振動数ｆ０を逆算すると、実験で用いた
減速機のいずれを組込んだ場合も約８．４１１ｚとなる
。これは、共振が駆動系の剛性が最も低い時、即ち、負
荷状態が減速機のいわゆるロストモーションの範囲内に
ある時に生じ、その時のロストモーションばね定数に！
！が実験で用いたいずれの減速機の場合もおおよそ等し
いためと考えられる。As mentioned above, the torque fluctuation characteristics of each reducer are estimated from these experimental results, and when the natural torsional frequency f0 of the experimental equipment is calculated backwards using this estimation, it is possible to determine which of the reducers used in the experiment is assembled. Even if it is included, it will be about 8.411z. This occurs when the drive system has the lowest rigidity, that is, when the load condition is within the so-called lost motion range of the reducer, and the lost motion spring constant at that time!
! This is thought to be because they are approximately the same for all reducers used in the experiment.
次に、本発明に係る産業ロボットの関節駆動装置の第２
実施例を図面に基づいて説明する。Next, the second joint drive device for an industrial robot according to the present invention will be described.
Examples will be described based on the drawings.
第６図において、５０は本発明の第２実施例の関節駆動
装置である。関節駆動袋Ｎ５０は電動モータ１、前段減
速機２０および遊星歯車減速機２１が軸方向に順次配設
され、電動モータ１の出力軸７には入力回転軸８が取着
されている。入力回転軸８のモータ１側端には前段減速
機２０の入力歯車２２が一体に設けられ、その中間には
大歯車５１ａと小歯車５１ｂを有する第１のアイドルギ
ヤ５１が回転巨在に支持されている。遊星歯車減速機２
１のクランク軸３０の一端はモータ１側に突出した延在
部３０ａを有する。延在部３０ａのモータ１側端には第
２のアイドルギヤ５２が回転自在に支持され、その中間
には前段減速ａ２０の出力歯車２５が固着されている。In FIG. 6, 50 is a joint drive device according to a second embodiment of the present invention. In the joint drive bag N50, an electric motor 1, a pre-stage reducer 20, and a planetary gear reducer 21 are sequentially arranged in the axial direction, and an input rotating shaft 8 is attached to an output shaft 7 of the electric motor 1. The input gear 22 of the pre-stage reducer 20 is integrally provided at the end of the input rotating shaft 8 on the motor 1 side, and a first idle gear 51 having a large gear 51a and a small gear 51b is rotatably supported in the middle thereof. has been done. Planetary gear reducer 2
One end of the crankshaft 30 has an extending portion 30a that projects toward the motor 1 side. A second idle gear 52 is rotatably supported at the end of the extending portion 30a on the motor 1 side, and the output gear 25 of the first stage reduction gear a20 is fixed in the middle thereof.
第２のアイドルギヤ５２は入力歯車２２と噛み合いこれ
より歯数の多い大歯車５２ａおよび第１アイドルギヤ５
１の大歯車５１ａと噛み合いこれより歯数の少ない小歯
車５２ｂを有する。出力歯車２５は第１フイドルギヤ５
１の小歯車５１ｂと噛み合いこれより多い歯数を有する
。入力回転軸８、入力歯車２２、出力歯車２５、延在部
３０ａ、および第１、第２のアイドルギヤ５１．５２は
前段減速機２０としての平行軸減速機を構成する。アイ
ドルギヤ５１．５２を入れることにより、容量の割に回
転軸径の大きい市販電動モータ１を用いる場合であって
も、所定の前段減速比を得ることができる。他の構成お
よび作用は前述した第１実施例と同じであるので、該実
施例の説明に用いた符号を第６図に付け、その説明を省
略する。The second idle gear 52 meshes with the input gear 22, and a large gear 52a with a larger number of teeth than the input gear 22 and the first idle gear 5.
It has a small gear 52b which meshes with the large gear 51a of No. 1 and has a smaller number of teeth than the large gear 51a. The output gear 25 is the first fiddle gear 5
It meshes with the small gear 51b of No. 1 and has a larger number of teeth. The input rotating shaft 8, the input gear 22, the output gear 25, the extension portion 30a, and the first and second idle gears 51 and 52 constitute a parallel shaft reduction gear as the pre-stage reduction gear 20. By inserting the idle gears 51 and 52, a predetermined pre-stage reduction ratio can be obtained even when a commercially available electric motor 1 having a large rotary shaft diameter relative to its capacity is used. Since the other configurations and operations are the same as those of the first embodiment described above, the reference numerals used in the explanation of this embodiment are added to FIG. 6, and the explanation thereof will be omitted.
なお、本発明においては、前段減速機の減速比はロボッ
トのねじり発振周波数（固有ねじり振動数近辺の周波数
をいう）と電動モータの毎秒光たり最高回転数との比よ
り大きければよい。例えばロボットの固有ねじり振動数
ｆｏが５〜９ヘルツの場合であって電動モータ回転数が
最高２’０００ｒｐｍのときは、前段減速比ｉ、を１
／３．７〜１ ／６．７、後段減速比１２を１／３０〜
１／６０から選択することにより終域速比ｉが１ ／１
１０〜１ ／３２０であってロボットに発振を生じさせ
ない減速装置を得る。同様（「。が５〜９ Ｈｚの場合
）に電動モータ回転数が最高４０００ｒｐｍのときは、
前段減速比１１を１ ／７．４〜１ ／１３．３、後段
減速比１２を１／３゜〜１／６０から選択することによ
り、終域速比ｉが１ ／２１０〜１ ／６４０であって
ロボットに発振を生じさせない減速装置を得ることがで
きる。In the present invention, the reduction ratio of the pre-stage reduction gear only needs to be larger than the ratio between the robot's torsional oscillation frequency (a frequency near the natural torsional vibration frequency) and the electric motor's maximum rotational speed per second. For example, when the robot's natural torsional frequency fo is 5 to 9 Hz and the electric motor rotation speed is 2'000 rpm at maximum, the first stage reduction ratio i is set to 1.
/3.7 to 1 /6.7, rear reduction ratio 12 to 1/30
By selecting from 1/60, the final speed ratio i becomes 1/1.
To obtain a speed reduction device that has a speed of 10 to 1/320 and does not cause oscillation in a robot. Similarly (when "." is 5 to 9 Hz), when the electric motor rotation speed is maximum 4000 rpm,
By selecting the front stage reduction ratio 11 from 1/7.4 to 1/13.3 and the rear stage reduction ratio 12 from 1/3° to 1/60, the final speed ratio i can be set from 1/210 to 1/640. Therefore, it is possible to obtain a deceleration device that does not cause oscillation in the robot.
（発明の効果）
以上説明したように、本発明によれば、簡単な構造によ
り共振現象を電動モータの実用域から外すことができる
。本発明によれば遊星歯車減速機の減速比は１／６〜１
／２００、単位入力回転当たりの出力加振数は１つであ
るから、前段減速機との組み合わせによりロボット用と
して必要とされる減速比のほとんどを満足し、かつ、ロ
ボットに発振を生じさせない関節駆動装置を得ることが
できる。(Effects of the Invention) As described above, according to the present invention, the resonance phenomenon can be removed from the practical range of electric motors with a simple structure. According to the present invention, the reduction ratio of the planetary gear reducer is 1/6 to 1
/200, the number of output excitations per unit input rotation is one, so in combination with the front stage reducer, this joint satisfies most of the reduction ratios required for robots and does not cause oscillations in the robot. A driving device can be obtained.
第１図乃至第５図は本発明に係る産業ロボットの関節駆
動装置の第１実施例を説明する図であり、第１図はその
全体概略説明図、第２図はその要部断面図、第３図は第
２図のＩ［［−１１１矢視断面図、第４図は本発明に係
る産業ロボットの関節駆動装置の実施例および比較例の
性能を説明する図、第５図は第４図に係る実験例の全体
構成図、第６図は本発明の第２実施例を示す要部断面図
、第７図は減速装置一般の回転ばね定数を示す特性図で
ある。
ｌ・・・・・・電動モータ、
３・・・・・・減速装置、
５・・・・・・第１アーム（第１部材）、１２・・・・
・・第２アーム（第２部材）、２０・・・・・・前段減
速機、
２１・・・・・・後段減速機、
２８・・・・・・内歯歯車、
２９・・・・・・外歯歯車、
３０・・・・・・入力クランク軸（偏心入力軸）、３３
．３５ａ・・・・・・フランジ。1 to 5 are diagrams for explaining a first embodiment of the joint drive device for an industrial robot according to the present invention, FIG. 1 is an overall schematic explanatory diagram, FIG. 2 is a sectional view of the main parts thereof, FIG. 3 is a sectional view taken along arrow I[[-111 in FIG. 2, FIG. FIG. 4 is an overall configuration diagram of an experimental example, FIG. 6 is a sectional view of a main part showing a second embodiment of the present invention, and FIG. 7 is a characteristic diagram showing a rotational spring constant of a general reduction gear device. l...Electric motor, 3...Reduction device, 5...First arm (first member), 12...
...Second arm (second member), 20...First stage reducer, 21... Second stage reducer, 28...Internal gear, 29...・External gear, 30...Input crankshaft (eccentric input shaft), 33
．． 35a...Flange.
Claims (1)
たロボットの第２部材と、第１部材に一体的に取り付け
られた電動モータの回転を減速して第２部材に伝達する
歯車減速装置と、を備えた産業ロボットの関節駆動装置
において、前記歯車減速装置が、前記電動モータの回転
数を減速する前段減速機と、前段減速機の出力の回転数
を更に減速して前記第２部材に出力する後段の遊星歯車
減速機と、から構成され、前記遊星歯車減速機が、複数
の偏心入力軸を円周上に等配支持したフランジ、前記各
偏心入力軸と係合しその回転により偏心揺動させられる
外歯歯車および外歯歯車と噛み合い外歯歯車の歯数より
１つ多い歯数を有する内歯歯車を有し、前記前段減速機
が前記電動モータの出力軸に取着された入力歯車および
前記各偏心入力軸に取着された出力歯車を有する平行軸
減速機に構成され、前記遊星歯車減速機の減速比を１／
１５〜１／６０とし、かつ前記歯車減速装置全体の減速
比を１／４０〜１／３２０としたことを特徴とする産業
ロボットの関節駆動装置。A first member of the robot, a second member of the robot rotatably supported by the first member, and a gear that decelerates the rotation of an electric motor integrally attached to the first member and transmits the rotation to the second member. In the joint drive device for an industrial robot, the gear reduction device includes a pre-stage reducer that reduces the rotation speed of the electric motor; a second-stage planetary gear reducer that outputs output to two members; It has an external gear that is eccentrically oscillated by rotation and an internal gear that meshes with the external gear and has one more teeth than the external gear, and the pre-stage reducer is attached to the output shaft of the electric motor. The parallel shaft reducer has an input gear attached to the input shaft and an output gear attached to each of the eccentric input shafts, and the reduction ratio of the planetary gear reducer is set to 1/1.
15 to 1/60, and a reduction ratio of the entire gear reduction device is 1/40 to 1/320.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61061637A JPS62218088A (en) | 1986-03-18 | 1986-03-18 | Joint drive for industrial robot |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61061637A JPS62218088A (en) | 1986-03-18 | 1986-03-18 | Joint drive for industrial robot |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6324000A Division JP2561227B2 (en) | 1994-12-02 | 1994-12-02 | Decelerator for joint drive of industrial robot |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62218088A true JPS62218088A (en) | 1987-09-25 |
| JPH0513795B2 JPH0513795B2 (en) | 1993-02-23 |
Family
ID=13176915
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61061637A Granted JPS62218088A (en) | 1986-03-18 | 1986-03-18 | Joint drive for industrial robot |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS62218088A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07299791A (en) * | 1994-12-02 | 1995-11-14 | Teijin Seiki Co Ltd | Deceleration device for joint drive of industrial robot |
| JP2007211976A (en) * | 2007-02-02 | 2007-08-23 | Nabtesco Corp | Speed reducer |
| US8435149B2 (en) | 2006-02-07 | 2013-05-07 | Nabtesco Corporation | Reduction gear device |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB927684A (en) * | 1960-10-20 | 1963-06-06 | Merritt & Company Engineering | Epicyclic gearing |
| JPS56152594A (en) * | 1980-04-25 | 1981-11-26 | Meidensha Electric Mfg Co Ltd | Reduction gear for manipulator |
| JPS57121490A (en) * | 1980-12-19 | 1982-07-28 | Kuka Shiyubuaisuanraagen Unto | Gearing for hinge head coupled with jib of manipulator |
| JPS59106744A (en) * | 1982-12-07 | 1984-06-20 | Sumitomo Heavy Ind Ltd | Method and device for installing eccentric body in planetary gear mechanism |
| JPS59108853U (en) * | 1983-01-14 | 1984-07-23 | 東洋精密造機株式会社 | Motor-directly connected planetary gear reduction device |
-
1986
- 1986-03-18 JP JP61061637A patent/JPS62218088A/en active Granted
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB927684A (en) * | 1960-10-20 | 1963-06-06 | Merritt & Company Engineering | Epicyclic gearing |
| JPS56152594A (en) * | 1980-04-25 | 1981-11-26 | Meidensha Electric Mfg Co Ltd | Reduction gear for manipulator |
| JPS57121490A (en) * | 1980-12-19 | 1982-07-28 | Kuka Shiyubuaisuanraagen Unto | Gearing for hinge head coupled with jib of manipulator |
| JPS59106744A (en) * | 1982-12-07 | 1984-06-20 | Sumitomo Heavy Ind Ltd | Method and device for installing eccentric body in planetary gear mechanism |
| JPS59108853U (en) * | 1983-01-14 | 1984-07-23 | 東洋精密造機株式会社 | Motor-directly connected planetary gear reduction device |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH07299791A (en) * | 1994-12-02 | 1995-11-14 | Teijin Seiki Co Ltd | Deceleration device for joint drive of industrial robot |
| US8435149B2 (en) | 2006-02-07 | 2013-05-07 | Nabtesco Corporation | Reduction gear device |
| JP2007211976A (en) * | 2007-02-02 | 2007-08-23 | Nabtesco Corp | Speed reducer |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0513795B2 (en) | 1993-02-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPH0429986Y2 (en) | ||
| WO1986005470A1 (en) | Joint driving apparatus for industrial robots | |
| EP0781383B1 (en) | Driving unit for an industrial robot | |
| JP2561227B2 (en) | Decelerator for joint drive of industrial robot | |
| JP2827166B2 (en) | Planetary gear reducer | |
| JPS62218088A (en) | Joint drive for industrial robot | |
| JPS62218087A (en) | Reduction gear for industrial robot | |
| JP2841060B2 (en) | Industrial Robot Joint Device | |
| JP2590404B2 (en) | Industrial Robot Joint Device | |
| JP2742912B2 (en) | Industrial Robot Joint Device | |
| JPS63109994A (en) | Wrist mechanism for industrial robot | |
| JP2534231B2 (en) | Industrial robot joint drive | |
| JPH10586A6 (en) | Industrial Robot Joint Device | |
| JPH10184799A (en) | Speed increasing pendulum type motion absorber | |
| JP3046958B2 (en) | Eccentric oscillating planetary gear reducer | |
| JP4831319B2 (en) | Motor with reduction gear | |
| JPH1029189A (en) | Joint device for industrial robot | |
| JP2590404C (en) | ||
| JP2561227C (en) | ||
| JPH0914350A (en) | Device and method for damping torsion vibration | |
| JPS6332441Y2 (en) | ||
| JPH03245777A (en) | Driver | |
| SU1088923A2 (en) | Electric vibratory net-driver | |
| JPS59113342A (en) | Reduction gear | |
| SU1611462A1 (en) | Vibration exciter |