WO2014030292A1 - Eccentrically rocking-type gear device - Google Patents

Eccentrically rocking-type gear device Download PDF

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Publication number
WO2014030292A1
WO2014030292A1 PCT/JP2013/004462 JP2013004462W WO2014030292A1 WO 2014030292 A1 WO2014030292 A1 WO 2014030292A1 JP 2013004462 W JP2013004462 W JP 2013004462W WO 2014030292 A1 WO2014030292 A1 WO 2014030292A1
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WO
WIPO (PCT)
Prior art keywords
outer cylinder
gear
carrier
eccentric
gear device
Prior art date
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PCT/JP2013/004462
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French (fr)
Japanese (ja)
Inventor
江児 中村
Original Assignee
ナブテスコ株式会社
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Publication date
Application filed by ナブテスコ株式会社 filed Critical ナブテスコ株式会社
Priority to CN201380043885.7A priority Critical patent/CN104583645B/en
Priority to KR1020157026574A priority patent/KR20150117296A/en
Priority to KR1020197023270A priority patent/KR20190095559A/en
Priority to DE112013003689.4T priority patent/DE112013003689B4/en
Priority to KR20157006953A priority patent/KR20150038700A/en
Publication of WO2014030292A1 publication Critical patent/WO2014030292A1/en

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    • 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
    • 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

Definitions

  • the present invention relates to an eccentric oscillating gear device.
  • an eccentric oscillating gear device that reduces the rotational speed at a predetermined reduction ratio between two mating members.
  • the eccentric oscillating gear device includes an outer cylinder fixed to one counterpart member, and a carrier disposed in the outer cylinder and fixed to the other counterpart member.
  • the carrier rotates relative to the outer cylinder by the swinging rotation of the swinging gear attached to the eccentric part of the crankshaft.
  • An object of the present invention is to suppress the shortening of the life of the oscillating gear by suppressing an increase in the surface pressure of the tooth surface of the oscillating gear.
  • An eccentric oscillating gear device is a gear device that transmits a driving force by converting a rotational speed at a predetermined rotational speed ratio between a first member and a second member, An eccentric portion, an oscillating gear having an insertion hole into which the eccentric portion is inserted and a tooth portion, an outer cylinder configured to be attachable to one of the first member and the second member, A carrier configured to be attachable to the other of the first member and the second member.
  • the outer cylinder has an internal tooth that meshes with the tooth portion of the swing gear.
  • the carrier is arranged on the radially inner side of the outer cylinder while holding the rocking gear.
  • the outer cylinder and the carrier are concentrically rotatable relative to each other by the swinging of the swinging gear accompanying the rotation of the eccentric part.
  • the backlash angle is set to 2 to 3 minutes so that the backlash angle of the carrier with respect to the outer cylinder becomes approximately 1 minute due to thermal expansion of the oscillating gear in use. ing.
  • An eccentric oscillating gear device (hereinafter referred to as a gear device) 1 according to this embodiment is applied as a speed reducer to, for example, a revolving part of a revolving trunk or arm joint of a robot, a revolving part of various machine tools, or the like. is there.
  • the gear device 1 is used in a rotational speed range of, for example, 80 rpm to 200 rpm (80 rpm or more and 200 rpm or less).
  • gear device 1 when the input shaft 8 rotates, the crankshaft 10 rotates, and the oscillating gears 14 and 16 oscillate and rotate in conjunction with the eccentric portions 10a and 10b of the crankshaft 10.
  • an output rotation decelerated from the input rotation is obtained.
  • relative rotation can be generated between the base of the robot (one counterpart member) and the turning drum (the other counterpart member).
  • the gear device 1 includes an outer cylinder 2, a carrier 4, an input shaft 8, a plurality of (for example, three) crankshafts 10, and a swing gear (first The oscillating gear 14 and the second oscillating gear 16) and a plurality of (for example, three) transmission gears 20 are provided.
  • the outer cylinder 2 constitutes the outer surface of the gear device 1 and has a substantially cylindrical shape.
  • the outer cylinder 2 is fastened to, for example, a robot base (not shown; first member).
  • a large number of pin grooves 2 b are formed on the inner peripheral surface of the outer cylinder 2.
  • Each pin groove 2b is disposed so as to extend in the axial direction of the outer cylinder 2, and has a semicircular cross-sectional shape in a cross section orthogonal to the axial direction.
  • These pin grooves 2 b are arranged on the inner peripheral surface of the outer cylinder 2 at equal intervals in the circumferential direction.
  • the outer cylinder 2 has a large number of internal tooth pins 3.
  • Each internal tooth pin 3 is attached to a pin groove 2b.
  • each internal tooth pin 3 is fitted in the corresponding pin groove 2 b and is arranged in a posture extending in the axial direction of the outer cylinder 2.
  • the many internal tooth pins 3 are arranged at equal intervals along the circumferential direction of the outer cylinder 2.
  • the first external teeth 14 a of the first oscillating gear 14 and the second external teeth 16 a of the second oscillating gear 16 are engaged with these internal tooth pins 3.
  • the outer cylinder 2 is provided with a flange portion.
  • the flange portion is formed with an insertion hole 2c for inserting a fastener (bolt) for fixing to the base of the robot, for example.
  • the carrier 4 is accommodated inside the outer cylinder 2 in a state of being arranged coaxially with the outer cylinder 2.
  • the carrier 4 is fastened to, for example, a revolving drum (not shown; second member) of the robot.
  • the carrier 4 rotates relative to the outer cylinder 2 around the same axis as the outer cylinder 2.
  • the carrier 4 is disposed on the radially inner side of the outer cylinder 2.
  • the carrier 4 is supported so as to be relatively rotatable with respect to the outer cylinder 2 by a pair of main bearings 6 provided to be separated from each other in the axial direction.
  • the carrier 4 includes a base portion having a substrate portion 4a and a plurality of (for example, three) shaft portions 4c, and an end plate portion 4b.
  • the substrate portion 4a is disposed in the outer cylinder 2 in the vicinity of one end portion in the axial direction.
  • a circular through hole 4d is provided in the central portion in the radial direction of the substrate portion 4a.
  • a plurality of (for example, three) crankshaft mounting holes 4e (hereinafter simply referred to as mounting holes 4e) are provided at equal intervals in the circumferential direction.
  • a fastening hole 4i for fastening an unillustrated fastener (bolt) for fixing the carrier 4 to, for example, a rotating drum of the robot is formed in the substrate portion 4a.
  • the end plate portion 4b is provided to be spaced apart from the substrate portion 4a in the axial direction, and is disposed in the vicinity of the other end portion in the axial direction in the outer cylinder 2.
  • a through hole 4f is provided at the radial center of the end plate portion 4b.
  • a plurality of (for example, three) crankshaft mounting holes 4g (hereinafter simply referred to as mounting holes 4g) are provided around the through hole 4f.
  • Each mounting hole 4g is arranged at a position corresponding to each mounting hole 4e of the substrate portion 4a.
  • a closed space surrounded by both inner surfaces of the end plate portion 4 b and the substrate portion 4 a facing each other and the inner peripheral surface of the outer cylinder 2 is formed.
  • the plurality of shaft portions 4c are provided integrally with the substrate portion 4a, and linearly extend from one main surface (inner surface) of the substrate portion 4a toward the end plate portion 4b.
  • the plurality of shaft portions 4c are arranged at equal intervals in the circumferential direction (see FIG. 2A).
  • Each shaft portion 4c is fastened to the end plate portion 4b by a bolt 4h (see FIG. 1). Thereby, the board
  • the input shaft 8 functions as an input unit for inputting a driving force of a driving motor (not shown).
  • the input shaft 8 is inserted into the through hole 4f of the end plate portion 4b and the through hole 4d of the substrate portion 4a.
  • the input shaft 8 is arranged such that its axis coincides with the axes of the outer cylinder 2 and the carrier 4 and rotates around the axis.
  • An input gear 8 a is provided on the outer peripheral surface of the distal end portion of the input shaft 8.
  • the plurality of crankshafts 10 are arranged at equal intervals around the input shaft 8 in the outer cylinder 2 (see FIG. 2A).
  • Each crankshaft 10 is supported by a pair of crank bearings 12a and 12b so as to be rotatable about the axis with respect to the carrier 4 (see FIG. 1).
  • the first crank bearing 12a is attached to a portion on the inner side in the axial direction by a predetermined length from one axial end of each crankshaft 10.
  • the first crank bearing 12a is mounted in the mounting hole 4e of the substrate portion 4a.
  • a second crank bearing 12b is attached to the other axial end of each crankshaft 10.
  • the second crank bearing 12b is mounted in the mounting hole 4g of the end plate portion 4b.
  • Each crankshaft 10 has a shaft body 10c and eccentric parts 10a and 10b formed integrally with the shaft body 10c.
  • the 1st eccentric part 10a and the 2nd eccentric part 10b are arrange
  • Each of the first eccentric portion 10a and the second eccentric portion 10b has a columnar shape, and both of the first eccentric portion 10a and the second eccentric portion 10b protrude radially outward from the shaft body 10c in a state of being eccentric with respect to the shaft center of the shaft body 10c.
  • the first eccentric portion 10a and the second eccentric portion 10b are each eccentric from the shaft center by a predetermined eccentric amount, and are disposed so as to have a phase difference of a predetermined angle.
  • a fitted portion 10d to which the transmission gear 20 is attached is provided at one end portion of the crankshaft 10, that is, a portion outside the axial direction of the portion attached in the attachment hole 4e of the substrate portion 4a.
  • the first oscillating gear 14 is disposed in the closed space in the outer cylinder 2 and is attached to the first eccentric portion 10a of each crankshaft 10 via a first roller bearing 18a.
  • first roller bearing 18a When each crankshaft 10 rotates and the first eccentric portion 10a rotates eccentrically, the first swing gear 14 swings and rotates while meshing with the internal tooth pin 3 in conjunction with the eccentric rotation.
  • the first oscillating gear 14 has a size slightly smaller than the inner diameter of the outer cylinder 2.
  • the first swing gear 14 includes a first external tooth 14a, a central through hole 14b, a plurality (for example, three) of first eccentric portion insertion holes 14c, and a plurality (for example, three) of shaft portion insertion holes 14d. And have.
  • the first external teeth 14 a have a wave shape that is smoothly continuous over the entire circumferential direction of the oscillating gear 14.
  • the central through hole 14b is provided in the central portion in the radial direction of the first oscillating gear 14.
  • the input shaft 8 is inserted into the central through hole 14b with play.
  • the plurality of first eccentric portion insertion holes 14 c are provided at equal intervals in the circumferential direction around the central through hole 14 b in the first swing gear 14.
  • the first eccentric portions 10a of the respective crankshafts 10 are inserted into the first eccentric portion insertion holes 14c with the first roller bearings 18a interposed therebetween.
  • the plurality of shaft portion insertion holes 14d are provided at equal intervals in the circumferential direction around the central through hole 14b in the first swing gear 14. Each shaft portion insertion hole 14d is disposed at a position between adjacent first eccentric portion insertion holes 14c in the circumferential direction. The corresponding shaft portion 4c is inserted into each shaft portion insertion hole 14d with play.
  • the second oscillating gear 16 is disposed in the closed space in the outer cylinder 2 and is attached to the second eccentric portion 10b of each crankshaft 10 via a second roller bearing 18b.
  • the first oscillating gear 14 and the second oscillating gear 16 are provided side by side in the axial direction corresponding to the arrangement of the first eccentric portion 10a and the second eccentric portion 10b.
  • the second swinging gear 16 swings and rotates while meshing with the internal tooth pin 3 in conjunction with the eccentric rotation.
  • the second oscillating gear 16 has a size slightly smaller than the inner diameter of the outer cylinder 2 and has the same configuration as the first oscillating gear 14. That is, the second oscillating gear 16 includes a second external tooth 16a, a central through hole 16b, a plurality of (for example, three) second eccentric portion insertion holes 16c, and a plurality of (for example, three) shaft portion insertion holes 16d. Have. These have the same structure as the first external teeth 14a, the central through hole 14b, the plurality of first eccentric portion insertion holes 14c, and the plurality of shaft portion insertion holes 14d of the first swing gear 14. The second eccentric portion 10b of the crankshaft 10 is inserted into each second eccentric portion insertion hole 16c with the second roller bearing 18b interposed therebetween.
  • Each transmission gear 20 transmits the rotation of the input gear 8a to the corresponding crankshaft 10.
  • Each transmission gear 20 is externally fitted to a fitted portion 10d provided at one end of the corresponding shaft body 10c of the crankshaft 10.
  • Each transmission gear 20 rotates integrally with the crankshaft 10 about the same axis as the rotation axis of the crankshaft 10.
  • Each transmission gear 20 has external teeth 20a that mesh with the input gear 8a.
  • the backlash angle is an angle at which when the torque is applied to the carrier 4 while the input shaft is fixed, the carrier 4 rotates around the axis while the torque is zero. That is, since there is a gap between the external teeth 14a and 16a of the swing gears 14 and 16 in the carrier 4 and the internal tooth pin 3 in the outer cylinder 2, as shown in FIG. When the torque is applied to the outer teeth 14a and 16a, the outer teeth 14a and 16a are slightly rotated with the torque zero until the outer teeth 14a and 16a mesh with the inner tooth pin 3. This rotation angle is an angle corresponding to the size of the gap between the external teeth 14a, 16a and the internal tooth pin 3.
  • the torsion angle of the carrier 4 becomes a magnitude corresponding to the magnitude of the applied torque.
  • the carrier 4 can be rotated while the torque is zero at a backlash angle corresponding to the size of the gap, and the magnitude of the backlash angle affects the positioning accuracy (stopping accuracy) of the robot. Therefore, in general, the shapes of the outer cylinder and the swing gear are set so that the backlash angle is about 1 minute (1 / 60th of a degree).
  • the backlash angle is set to 2 to 3 minutes before use. That is, the outer cylinder 2 radiates heat to the outside air or radiates heat to a mating member (for example, the base of the robot), and therefore has a smaller amount of thermal expansion than the rocking gears 14 and 16 and the internal tooth pin 3. For this reason, when the gear device 1 is operated, the clearance (clearance) between the external teeth 14a, 16a of the rocking gears 14, 16 and the internal tooth pin 3 tends to be narrowed. Thereby, in the gear apparatus 1 of this embodiment, when the clearance becomes narrower than before use due to the temperature rise during use, the backlash angle is set to approximately 1 minute. For example, by reducing the outer diameter of the internal tooth pin 3 as compared with the conventional one, a clearance corresponding to the clearance reduction due to heat generation can be added in advance.
  • FIG. 4 shows a change from the state before use of the backlash angle due to heat generation during use.
  • the temperature of the outer cylinder 2 rises to about 70 to 80 ° C. Therefore, when the backlash angle is 2 minutes before use (for example, 20 ° C.), the backlash angle at 70 ° C. is less than 1 minute (about 0.6 minutes).
  • the backlash angle at 70 ° C. is about 1.2 minutes. Therefore, if the backlash angle in the state before use is 2 to 3 minutes (2 minutes or more and within 3 minutes), the backlash angle during use is about 1 minute (0.6 minutes or more and 1. Within 2 minutes).
  • the backlash angle is set to 2 to 3 minutes, so that when the gear device 1 is operated, the rocking gears 14 and 16 are heated to expand.
  • the backlash angle of the carrier 4 with respect to the outer cylinder 2 can be reduced to about 1 minute. Therefore, when used, the backlash angle of the carrier 4 with respect to the outer cylinder 2 does not become excessive, so that the stopping accuracy of the eccentric oscillating gear device 1 can be maintained. And since it can suppress that the surface pressure of the tooth surface of rocking gears 14 and 16 becomes high, reduction of the life of rocking gears 14 and 16 can be controlled. That is, it is possible to optimize the backlash angle during actual use.
  • the relative rotational speed between the outer cylinder 2 and the carrier 4 is 80 rpm to 200 rpm.
  • the rotation speed is used in a high speed region of 80 rpm to 200 rpm, the temperature of the oscillating gears 14 and 16 after the start of use is fast. Therefore, the time until the normal backlash angle (approximately 1 minute) is reached after the start of use is also short, and the warm-up operation time can be shortened or eliminated.
  • the present invention is not limited to the above-described embodiment, and various modifications and improvements can be made without departing from the spirit of the present invention.
  • the two swing gears 14 and 16 are provided.
  • the present invention is not limited to this.
  • a configuration in which one oscillating gear is provided or a configuration in which three or more oscillating gears are provided may be employed.
  • the input shaft 8 is disposed at the center of the carrier 4, and the plurality of crankshafts 10 are disposed around the input shaft 8.
  • the configuration is not limited to this.
  • a center crank type in which the crankshaft 10 is disposed at the center of the carrier 4 may be used. In this case, as long as the input shaft 8 is provided so as to mesh with the transmission gear 20 attached to the crankshaft 10, the input shaft 8 may be disposed at any position.
  • the outer cylinder 2 is coupled to the base of the robot
  • the carrier 4 is coupled to the revolving drum of the robot
  • the carrier 4 rotates with respect to the outer cylinder 2.
  • the configuration is not limited to this.
  • the carrier 4 may be coupled to the base of the robot and the outer cylinder 2 may be coupled to the swivel drum of the robot so that the outer cylinder 2 rotates with respect to the carrier 4.
  • the oscillating gear becomes hotter than the outer cylinder due to heat generation. For this reason, the clearance between the internal teeth disposed on the outer cylinder and the tooth portion of the oscillating gear tends to be narrower during use than before use. Therefore, when the backlash angle of the oscillating gear with respect to the outer cylinder is set to approximately 1 minute as in a normal eccentric oscillating gear device, the clearance (play) becomes narrow due to heat generated by the oscillating gear. This leads to an increase in the surface pressure of the tooth surface of the oscillating gear, and as a result, the fatigue strength is reduced. On the other hand, in this embodiment, the backlash angle is set to 2 to 3 minutes.
  • the backlash angle can be reduced to approximately 1 minute. Accordingly, since the backlash angle of the carrier with respect to the outer cylinder does not become excessive during use, the stopping accuracy can be maintained as the eccentric oscillating gear device. In addition, an increase in the surface pressure of the tooth surface of the oscillating gear can be suppressed, and a reduction in the life of the oscillating gear can be suppressed.
  • the relative rotational speed between the outer cylinder and the carrier may be 80 rpm to 200 rpm.
  • the rotation speed is used in a high speed range of 80 rpm to 200 rpm, the temperature of the rocking gear rises quickly after the start of use. Therefore, the time until the normal backlash angle (approximately 1 minute) is reached after the start of use is also short, and the warm-up operation time can be shortened or eliminated.

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Abstract

An eccentrically rocking-type gear device (1) is provided with: an eccentric section (10a); a rocking gear (14) having an insertion hole into which the eccentric section (10a) is inserted and also having external teeth (14a); an outer cylinder (2); and a carrier (4). The outer cylinder (2) has internal tooth pins (3) meshing with the external teeth (14a) of the rocking gear (14). The carrier (4) is disposed on the inside radially of the outer cylinder (2) while holding the rocking gear (14). The outer cylinder (2) and the carrier (4) can be concentrically rotated relative to each other by the rocking of the rocking gear (14) caused by the rotation of the eccentric section (10a). The backlash angle of the carrier (4) relative to the outer cylinder (2) is set in the range of two to three minutes so that the backlash angle becomes about one minute due to the thermal expansion of the rocking gear (14) during use.

Description

偏心揺動型歯車装置Eccentric oscillating gear unit
　本発明は、偏心揺動型歯車装置に関する。 The present invention relates to an eccentric oscillating gear device.
　従来、下記特許文献１に開示されているように、二つの相手部材間で所定の減速比で回転数を減速する偏心揺動型歯車装置が知られている。この偏心揺動型歯車装置は、一方の相手部材に固定される外筒と、外筒内に配置されるとともに、もう一方の相手部材に固定されるキャリアとを備えている。キャリアは、クランク軸の偏心部に取り付けられた揺動歯車の揺動回転によって、外筒に対して相対的に回転する。 Conventionally, as disclosed in Patent Document 1 below, an eccentric oscillating gear device that reduces the rotational speed at a predetermined reduction ratio between two mating members is known. The eccentric oscillating gear device includes an outer cylinder fixed to one counterpart member, and a carrier disposed in the outer cylinder and fixed to the other counterpart member. The carrier rotates relative to the outer cylinder by the swinging rotation of the swinging gear attached to the eccentric part of the crankshaft.
特開２００６－７７９８０号公報JP 2006-77980 A
　近年、ロボットの使用環境の変化により、ロボットの稼働率が上げられる傾向にあり、これに伴い減速機についても高速化が要求されている。偏心揺動型歯車装置の使用時には、キャリア内の温度が外筒の温度よりも高くなる。このため、使用時には揺動歯車が熱膨張する。この熱膨張により、揺動歯車の外歯と外筒の内歯との間のすき間が狭くなり、揺動歯車の歯面の面圧が高くなる。その結果、揺動歯車の寿命が短くなる。 In recent years, there has been a tendency that the operating rate of the robot is increased due to changes in the usage environment of the robot, and accordingly, speeding up of the reduction gear is also required. When the eccentric oscillating gear device is used, the temperature in the carrier becomes higher than the temperature of the outer cylinder. For this reason, the rocking gear thermally expands during use. Due to this thermal expansion, the gap between the outer teeth of the swing gear and the inner teeth of the outer cylinder is narrowed, and the surface pressure of the tooth surface of the swing gear is increased. As a result, the life of the oscillating gear is shortened.
　本発明の目的は、揺動歯車の歯面の面圧が高くなることを抑制することにより、揺動歯車の寿命が短くなることを抑制することである。 An object of the present invention is to suppress the shortening of the life of the oscillating gear by suppressing an increase in the surface pressure of the tooth surface of the oscillating gear.
　本発明の一局面に従う偏心揺動型歯車装置は、第１の部材と第２の部材との間で所定の回転数比で回転数を変換して駆動力を伝達する歯車装置であって、偏心部と、前記偏心部が挿入される挿通孔を有すると共に歯部を有する揺動歯車と、前記第１の部材及び前記第２の部材の一方に取り付け可能に構成される外筒と、前記第１の部材及び前記第２の部材の他方に取り付け可能に構成されるキャリアと、を備える。前記外筒は、前記揺動歯車の前記歯部と噛み合う内歯を有している。前記キャリアは、前記揺動歯車を保持した状態で前記外筒の径方向内側に配置される。前記外筒と前記キャリアとは、前記偏心部の回転に伴う前記揺動歯車の揺動によって同心状に互いに相対的に回転可能である。この偏心揺動型歯車装置では、使用時における前記揺動歯車の熱膨張によって前記外筒に対する前記キャリアのバックラッシ角度が略１分になるように、前記バックラッシ角度は２分～３分に設定されている。 An eccentric oscillating gear device according to one aspect of the present invention is a gear device that transmits a driving force by converting a rotational speed at a predetermined rotational speed ratio between a first member and a second member, An eccentric portion, an oscillating gear having an insertion hole into which the eccentric portion is inserted and a tooth portion, an outer cylinder configured to be attachable to one of the first member and the second member, A carrier configured to be attachable to the other of the first member and the second member. The outer cylinder has an internal tooth that meshes with the tooth portion of the swing gear. The carrier is arranged on the radially inner side of the outer cylinder while holding the rocking gear. The outer cylinder and the carrier are concentrically rotatable relative to each other by the swinging of the swinging gear accompanying the rotation of the eccentric part. In this eccentric oscillating gear device, the backlash angle is set to 2 to 3 minutes so that the backlash angle of the carrier with respect to the outer cylinder becomes approximately 1 minute due to thermal expansion of the oscillating gear in use. ing.
本発明の実施形態に係る偏心揺動型歯車装置の構成を示す断面図である。It is sectional drawing which shows the structure of the eccentric rocking | fluctuation type gear apparatus which concerns on embodiment of this invention. （Ａ）図１のＩＩ－ＩＩ線における断面図であり、（Ｂ）は（Ａ）の部分拡大図である。(A) It is sectional drawing in the II-II line of FIG. 1, (B) is the elements on larger scale of (A). バックラッシ角度を説明するための図である。It is a figure for demonstrating a backlash angle. 外筒の温度変化に伴うバックラッシ角度の変化を説明するための図である。It is a figure for demonstrating the change of the backlash angle accompanying the temperature change of an outer cylinder.
　以下、本発明の実施形態に係る偏心揺動型歯車装置について図面を参照して詳細に説明する。
　本実施形態の偏心揺動型歯車装置（以下、歯車装置と称する）１は、例えばロボットの旋回胴や腕関節等の旋回部、各種工作機械の旋回部等に減速機として適用されるものである。この歯車装置１は、例えば、８０ｒｐｍ～２００ｒｐｍ（毎分８０回転以上で且つ毎分２００回転以下）の回転数範囲で使用される。 Hereinafter, an eccentric oscillating gear device according to an embodiment of the present invention will be described in detail with reference to the drawings.
An eccentric oscillating gear device (hereinafter referred to as a gear device) 1 according to this embodiment is applied as a speed reducer to, for example, a revolving part of a revolving trunk or arm joint of a robot, a revolving part of various machine tools, or the like. is there. The gear device 1 is used in a rotational speed range of, for example, 80 rpm to 200 rpm (80 rpm or more and 200 rpm or less).
　本実施形態に係る歯車装置１は、入力軸８が回転することによってクランク軸１０が回転し、クランク軸１０の偏心部１０ａ，１０ｂに連動して揺動歯車１４，１６が揺動回転することにより、入力回転から減速した出力回転を得るように構成されている。この歯車装置１では、例えばロボットのベース（一方の相手部材）と旋回胴（他方の相手部材）との間で、相対回転を生じさせることができる。 In the gear device 1 according to the present embodiment, when the input shaft 8 rotates, the crankshaft 10 rotates, and the oscillating gears 14 and 16 oscillate and rotate in conjunction with the eccentric portions 10a and 10b of the crankshaft 10. Thus, an output rotation decelerated from the input rotation is obtained. In the gear device 1, for example, relative rotation can be generated between the base of the robot (one counterpart member) and the turning drum (the other counterpart member).
　図１及び図２（Ａ）に示すように、歯車装置１は、外筒２と、キャリア４と、入力軸８と、複数（例えば３つ）のクランク軸１０と、揺動歯車（第１揺動歯車１４及び第２揺動歯車１６）と、複数（例えば３つ）の伝達歯車２０とを備えている。 As shown in FIGS. 1 and 2A, the gear device 1 includes an outer cylinder 2, a carrier 4, an input shaft 8, a plurality of (for example, three) crankshafts 10, and a swing gear (first The oscillating gear 14 and the second oscillating gear 16) and a plurality of (for example, three) transmission gears 20 are provided.
　外筒２は、歯車装置１の外面を構成するものであり、略円筒形状を有している。外筒２は、例えばロボットのベース（図示省略；第１の部材）に締結される。外筒２の内周面には、多数のピン溝２ｂが形成されている。各ピン溝２ｂは、外筒２の軸方向に延びるように配置され、軸方向に直交する断面において半円形の断面形状を有している。これらのピン溝２ｂは、外筒２の内周面に周方向に等間隔で並んでいる。 The outer cylinder 2 constitutes the outer surface of the gear device 1 and has a substantially cylindrical shape. The outer cylinder 2 is fastened to, for example, a robot base (not shown; first member). A large number of pin grooves 2 b are formed on the inner peripheral surface of the outer cylinder 2. Each pin groove 2b is disposed so as to extend in the axial direction of the outer cylinder 2, and has a semicircular cross-sectional shape in a cross section orthogonal to the axial direction. These pin grooves 2 b are arranged on the inner peripheral surface of the outer cylinder 2 at equal intervals in the circumferential direction.
　外筒２は、多数の内歯ピン３を有している。各内歯ピン３は、ピン溝２ｂにそれぞれ取り付けられている。具体的に、各内歯ピン３は、対応するピン溝２ｂにそれぞれ嵌め込まれており、外筒２の軸方向に延びる姿勢で配置されている。これにより、多数の内歯ピン３は、外筒２の周方向に沿って等間隔で並んでいる。これらの内歯ピン３には、第１揺動歯車１４の第１外歯１４ａ及び第２揺動歯車１６の第２外歯１６ａが噛み合う。 The outer cylinder 2 has a large number of internal tooth pins 3. Each internal tooth pin 3 is attached to a pin groove 2b. Specifically, each internal tooth pin 3 is fitted in the corresponding pin groove 2 b and is arranged in a posture extending in the axial direction of the outer cylinder 2. Thereby, the many internal tooth pins 3 are arranged at equal intervals along the circumferential direction of the outer cylinder 2. The first external teeth 14 a of the first oscillating gear 14 and the second external teeth 16 a of the second oscillating gear 16 are engaged with these internal tooth pins 3.
　外筒２には、フランジ部が設けられており、このフランジ部は、例えばロボットのベースに固定するための締結具（ボルト）を挿通するための挿通孔２ｃが形成されている。 The outer cylinder 2 is provided with a flange portion. The flange portion is formed with an insertion hole 2c for inserting a fastener (bolt) for fixing to the base of the robot, for example.
　キャリア４は、外筒２と同軸上に配置された状態で外筒２の内側に収容されている。キャリア４は、例えばロボットの旋回胴（図示省略；第２の部材）に締結される。キャリア４は、外筒２に対して、外筒２と同じ軸回りに相対回転する。具体的に、キャリア４は、外筒２の径方向内側に配置されている。この状態で、キャリア４は、軸方向に互いに離間して設けられた一対の主軸受６によって、外筒２に対して相対回転可能に支持されている。 The carrier 4 is accommodated inside the outer cylinder 2 in a state of being arranged coaxially with the outer cylinder 2. The carrier 4 is fastened to, for example, a revolving drum (not shown; second member) of the robot. The carrier 4 rotates relative to the outer cylinder 2 around the same axis as the outer cylinder 2. Specifically, the carrier 4 is disposed on the radially inner side of the outer cylinder 2. In this state, the carrier 4 is supported so as to be relatively rotatable with respect to the outer cylinder 2 by a pair of main bearings 6 provided to be separated from each other in the axial direction.
　キャリア４は、基板部４ａと複数（例えば３つ）のシャフト部４ｃとを有する基部と、端板部４ｂと、を備えている。 The carrier 4 includes a base portion having a substrate portion 4a and a plurality of (for example, three) shaft portions 4c, and an end plate portion 4b.
　基板部４ａは、外筒２内において軸方向の一端部近傍に配置されている。基板部４ａの径方向中央部には、円形の貫通孔４ｄが設けられている。貫通孔４ｄの周囲には、複数（例えば３つ）のクランク軸取付孔４ｅ（以下、単に取付孔４ｅという）が、周方向に等間隔で設けられている。 The substrate portion 4a is disposed in the outer cylinder 2 in the vicinity of one end portion in the axial direction. A circular through hole 4d is provided in the central portion in the radial direction of the substrate portion 4a. Around the through hole 4d, a plurality of (for example, three) crankshaft mounting holes 4e (hereinafter simply referred to as mounting holes 4e) are provided at equal intervals in the circumferential direction.
　基板部４ａには、キャリア４を例えばロボットの旋回胴に固定するための図略の締結具（ボルト）を締結するための締結孔４ｉが形成されている。 A fastening hole 4i for fastening an unillustrated fastener (bolt) for fixing the carrier 4 to, for example, a rotating drum of the robot is formed in the substrate portion 4a.
　端板部４ｂは、基板部４ａに対して軸方向に離間して設けられており、外筒２内において軸方向の他端部近傍に配置されている。端板部４ｂの径方向中央部には貫通孔４ｆが設けられている。貫通孔４ｆの周囲には、複数（例えば３つ）のクランク軸取付孔４ｇ（以下、単に取付孔４ｇという）が設けられている。各取付孔４ｇは、それぞれ基板部４ａの取付孔４ｅと対応する位置に配置されている。外筒２内には、端板部４ｂ及び基板部４ａの互いに対向する双方の内面と、外筒２の内周面とで囲まれた閉空間が形成されている。 The end plate portion 4b is provided to be spaced apart from the substrate portion 4a in the axial direction, and is disposed in the vicinity of the other end portion in the axial direction in the outer cylinder 2. A through hole 4f is provided at the radial center of the end plate portion 4b. A plurality of (for example, three) crankshaft mounting holes 4g (hereinafter simply referred to as mounting holes 4g) are provided around the through hole 4f. Each mounting hole 4g is arranged at a position corresponding to each mounting hole 4e of the substrate portion 4a. In the outer cylinder 2, a closed space surrounded by both inner surfaces of the end plate portion 4 b and the substrate portion 4 a facing each other and the inner peripheral surface of the outer cylinder 2 is formed.
　複数のシャフト部４ｃは、基板部４ａと一体的に設けられており、基板部４ａの一主面（内側面）から端板部４ｂ側へ直線的に延びている。この複数のシャフト部４ｃは、周方向に等間隔で配設されている（図２（Ａ）参照）。各シャフト部４ｃは、ボルト４ｈによって端板部４ｂに締結されている（図１参照）。これにより、基板部４ａ、シャフト部４ｃ及び端板部４ｂが一体化されている。 The plurality of shaft portions 4c are provided integrally with the substrate portion 4a, and linearly extend from one main surface (inner surface) of the substrate portion 4a toward the end plate portion 4b. The plurality of shaft portions 4c are arranged at equal intervals in the circumferential direction (see FIG. 2A). Each shaft portion 4c is fastened to the end plate portion 4b by a bolt 4h (see FIG. 1). Thereby, the board | substrate part 4a, the shaft part 4c, and the end plate part 4b are integrated.
　入力軸８は、図略の駆動モータの駆動力が入力される入力部として機能する。入力軸８は、端板部４ｂの貫通孔４ｆ及び基板部４ａの貫通孔４ｄに挿入されている。入力軸８は、その軸心が外筒２及びキャリア４の軸心と一致するように配置されており、軸回りに回転する。入力軸８の先端部の外周面には入力ギア８ａが設けられている。 The input shaft 8 functions as an input unit for inputting a driving force of a driving motor (not shown). The input shaft 8 is inserted into the through hole 4f of the end plate portion 4b and the through hole 4d of the substrate portion 4a. The input shaft 8 is arranged such that its axis coincides with the axes of the outer cylinder 2 and the carrier 4 and rotates around the axis. An input gear 8 a is provided on the outer peripheral surface of the distal end portion of the input shaft 8.
　複数のクランク軸１０は、外筒２内において入力軸８の周囲に等間隔で配置されている（図２（Ａ）参照）。各クランク軸１０は、一対のクランク軸受１２ａ，１２ｂにより、キャリア４に対して軸回りに回転可能に支持されている（図１参照）。具体的には、各クランク軸１０の軸方向の一端から所定長さだけ軸方向内側の部分に第１クランク軸受１２ａが取り付けられている。この第１クランク軸受１２ａは、基板部４ａの取付孔４ｅに装着されている。一方、各クランク軸１０の軸方向の他端部には、第２クランク軸受１２ｂが取り付けられている。この第２クランク軸受１２ｂは、端板部４ｂの取付孔４ｇに装着されている。これにより、クランク軸１０は、基板部４ａ及び端板部４ｂに回転可能に支持されている。 The plurality of crankshafts 10 are arranged at equal intervals around the input shaft 8 in the outer cylinder 2 (see FIG. 2A). Each crankshaft 10 is supported by a pair of crank bearings 12a and 12b so as to be rotatable about the axis with respect to the carrier 4 (see FIG. 1). Specifically, the first crank bearing 12a is attached to a portion on the inner side in the axial direction by a predetermined length from one axial end of each crankshaft 10. The first crank bearing 12a is mounted in the mounting hole 4e of the substrate portion 4a. On the other hand, a second crank bearing 12b is attached to the other axial end of each crankshaft 10. The second crank bearing 12b is mounted in the mounting hole 4g of the end plate portion 4b. Thereby, the crankshaft 10 is rotatably supported by the board | substrate part 4a and the end plate part 4b.
　各クランク軸１０は、軸本体１０ｃと、この軸本体１０ｃに一体的に形成された偏心部１０ａ，１０ｂとを有する。第１偏心部１０ａと第２偏心部１０ｂは、両クランク軸受１２ａ，１２ｂによって支持された部分の間に軸方向に並んで配置されている。第１偏心部１０ａと第２偏心部１０ｂは、それぞれ円柱形状を有しており、いずれも軸本体１０ｃの軸心に対して偏心した状態で軸本体１０ｃから径方向外側に張り出している。第１偏心部１０ａと第２偏心部１０ｂは、それぞれ軸心から所定の偏心量で偏心しており、互いに所定角度の位相差を有するように配置されている。 Each crankshaft 10 has a shaft body 10c and eccentric parts 10a and 10b formed integrally with the shaft body 10c. The 1st eccentric part 10a and the 2nd eccentric part 10b are arrange | positioned along with the axial direction between the parts supported by both crank bearings 12a and 12b. Each of the first eccentric portion 10a and the second eccentric portion 10b has a columnar shape, and both of the first eccentric portion 10a and the second eccentric portion 10b protrude radially outward from the shaft body 10c in a state of being eccentric with respect to the shaft center of the shaft body 10c. The first eccentric portion 10a and the second eccentric portion 10b are each eccentric from the shaft center by a predetermined eccentric amount, and are disposed so as to have a phase difference of a predetermined angle.
　クランク軸１０の一端部、すなわち、基板部４ａの取付孔４ｅ内に取り付けられる部分の軸方向外側の部位には、伝達歯車２０が取り付けられる被嵌合部１０ｄが設けられている。 A fitted portion 10d to which the transmission gear 20 is attached is provided at one end portion of the crankshaft 10, that is, a portion outside the axial direction of the portion attached in the attachment hole 4e of the substrate portion 4a.
　第１揺動歯車１４は、外筒２内の前記閉空間に配設されているとともに、各クランク軸１０の第１偏心部１０ａに第１ころ軸受１８ａを介して取り付けられている。第１揺動歯車１４は、各クランク軸１０が回転して第１偏心部１０ａが偏心回転すると、この偏心回転に連動して内歯ピン３に噛み合いながら揺動回転する。 The first oscillating gear 14 is disposed in the closed space in the outer cylinder 2 and is attached to the first eccentric portion 10a of each crankshaft 10 via a first roller bearing 18a. When each crankshaft 10 rotates and the first eccentric portion 10a rotates eccentrically, the first swing gear 14 swings and rotates while meshing with the internal tooth pin 3 in conjunction with the eccentric rotation.
　第１揺動歯車１４は、外筒２の内径よりも少し小さい大きさを有している。第１揺動歯車１４は、第１外歯１４ａと、中央部貫通孔１４ｂと、複数（例えば３つ）の第１偏心部挿通孔１４ｃと、複数（例えば３つ）のシャフト部挿通孔１４ｄとを有している。第１外歯１４ａは、揺動歯車１４の周方向全体に亘って滑らかに連続する波形状を有している。 The first oscillating gear 14 has a size slightly smaller than the inner diameter of the outer cylinder 2. The first swing gear 14 includes a first external tooth 14a, a central through hole 14b, a plurality (for example, three) of first eccentric portion insertion holes 14c, and a plurality (for example, three) of shaft portion insertion holes 14d. And have. The first external teeth 14 a have a wave shape that is smoothly continuous over the entire circumferential direction of the oscillating gear 14.
　中央部貫通孔１４ｂは、第１揺動歯車１４の径方向中央部に設けられている。中央部貫通孔１４ｂには、入力軸８が遊びを持った状態で挿通されている。 The central through hole 14b is provided in the central portion in the radial direction of the first oscillating gear 14. The input shaft 8 is inserted into the central through hole 14b with play.
　複数の第１偏心部挿通孔１４ｃは、第１揺動歯車１４において中央部貫通孔１４ｂの周囲に周方向に等間隔で設けられている。各第１偏心部挿通孔１４ｃには、第１ころ軸受１８ａが介装された状態で各クランク軸１０の第１偏心部１０ａがそれぞれ挿通されている。 The plurality of first eccentric portion insertion holes 14 c are provided at equal intervals in the circumferential direction around the central through hole 14 b in the first swing gear 14. The first eccentric portions 10a of the respective crankshafts 10 are inserted into the first eccentric portion insertion holes 14c with the first roller bearings 18a interposed therebetween.
　複数のシャフト部挿通孔１４ｄは、第１揺動歯車１４において中央部貫通孔１４ｂの周りに周方向に等間隔で設けられている。各シャフト部挿通孔１４ｄは、周方向において、隣り合う第１偏心部挿通孔１４ｃ間の位置にそれぞれ配設されている。各シャフト部挿通孔１４ｄには、対応するシャフト部４ｃが遊びを持った状態で挿通されている。 The plurality of shaft portion insertion holes 14d are provided at equal intervals in the circumferential direction around the central through hole 14b in the first swing gear 14. Each shaft portion insertion hole 14d is disposed at a position between adjacent first eccentric portion insertion holes 14c in the circumferential direction. The corresponding shaft portion 4c is inserted into each shaft portion insertion hole 14d with play.
　第２揺動歯車１６は、外筒２内の前記閉空間に配設されているとともに各クランク軸１０の第２偏心部１０ｂに第２ころ軸受１８ｂを介して取り付けられている。第１揺動歯車１４と第２揺動歯車１６は、第１偏心部１０ａと第２偏心部１０ｂの配置に対応して軸方向に並んで設けられている。第２揺動歯車１６は、各クランク軸１０が回転して第２偏心部１０ｂが偏心回転すると、この偏心回転に連動して内歯ピン３に噛み合いながら揺動回転する。 The second oscillating gear 16 is disposed in the closed space in the outer cylinder 2 and is attached to the second eccentric portion 10b of each crankshaft 10 via a second roller bearing 18b. The first oscillating gear 14 and the second oscillating gear 16 are provided side by side in the axial direction corresponding to the arrangement of the first eccentric portion 10a and the second eccentric portion 10b. When each crankshaft 10 rotates and the second eccentric portion 10b rotates eccentrically, the second swinging gear 16 swings and rotates while meshing with the internal tooth pin 3 in conjunction with the eccentric rotation.
　第２揺動歯車１６は、外筒２の内径よりも少し小さい大きさを有しており、第１揺動歯車１４と同様の構成となっている。すなわち、第２揺動歯車１６は、第２外歯１６ａ、中央部貫通孔１６ｂ、複数（例えば３つ）の第２偏心部挿通孔１６ｃ及び複数（例えば３つ）のシャフト部挿通孔１６ｄを有している。これらは、第１揺動歯車１４の第１外歯１４ａ、中央部貫通孔１４ｂ、複数の第１偏心部挿通孔１４ｃ及び複数のシャフト部挿通孔１４ｄと同様の構造を有している。各第２偏心部挿通孔１６ｃには、第２ころ軸受１８ｂが介装された状態でクランク軸１０の第２偏心部１０ｂが挿通されている。 The second oscillating gear 16 has a size slightly smaller than the inner diameter of the outer cylinder 2 and has the same configuration as the first oscillating gear 14. That is, the second oscillating gear 16 includes a second external tooth 16a, a central through hole 16b, a plurality of (for example, three) second eccentric portion insertion holes 16c, and a plurality of (for example, three) shaft portion insertion holes 16d. Have. These have the same structure as the first external teeth 14a, the central through hole 14b, the plurality of first eccentric portion insertion holes 14c, and the plurality of shaft portion insertion holes 14d of the first swing gear 14. The second eccentric portion 10b of the crankshaft 10 is inserted into each second eccentric portion insertion hole 16c with the second roller bearing 18b interposed therebetween.
　各伝達歯車２０は、入力ギア８ａの回転を対応するクランク軸１０に伝達するものである。各伝達歯車２０は、対応するクランク軸１０の軸本体１０ｃにおける一端部に設けられた被嵌合部１０ｄにそれぞれ外嵌されている。各伝達歯車２０は、クランク軸１０の回転軸と同じ軸回りにこのクランク軸１０と一体的に回転する。各伝達歯車２０は、入力ギア８ａと噛み合う外歯２０ａを有している。 Each transmission gear 20 transmits the rotation of the input gear 8a to the corresponding crankshaft 10. Each transmission gear 20 is externally fitted to a fitted portion 10d provided at one end of the corresponding shaft body 10c of the crankshaft 10. Each transmission gear 20 rotates integrally with the crankshaft 10 about the same axis as the rotation axis of the crankshaft 10. Each transmission gear 20 has external teeth 20a that mesh with the input gear 8a.
　ここで、本実施形態に係る歯車装置１におけるキャリア４のバックラッシ角度について説明する。バックラッシ角度とは、入力軸を固定した状態でキャリア４にトルクを加えたときに、トルクがゼロの状態でキャリア４が軸回りに回動する角度のことである。すなわち、キャリア４内の揺動歯車１４，１６の外歯１４ａ，１６ａと外筒２内の内歯ピン３との間には、図２（Ｂ）に示すようにすき間があるため、キャリア４にトルクを加えると、外歯１４ａ，１６ａが内歯ピン３に噛み合うまでトルクゼロの状態のまま僅かに回動する。この回動角度は、外歯１４ａ，１６ａと内歯ピン３との間のすき間の大きさに応じた角度となる。そして、図３に示すように、外歯１４ａ，１６ａが内歯ピン３に噛み合った状態では、キャリア４のねじれ角は、加えられたトルクの大きさに応じた大きさとなる。このように、キャリア４には、前記すき間の大きさに応じたバックラッシ角度でトルクゼロのまま回動が可能であり、このバックラッシ角度の大きさはロボットの位置決め精度（停止精度）に影響する。そこで、一般には、バックラッシ角度が約１分（６０分の１度）になるように、外筒及び揺動歯車の形状が設定されている。 Here, the backlash angle of the carrier 4 in the gear device 1 according to the present embodiment will be described. The backlash angle is an angle at which when the torque is applied to the carrier 4 while the input shaft is fixed, the carrier 4 rotates around the axis while the torque is zero. That is, since there is a gap between the external teeth 14a and 16a of the swing gears 14 and 16 in the carrier 4 and the internal tooth pin 3 in the outer cylinder 2, as shown in FIG. When the torque is applied to the outer teeth 14a and 16a, the outer teeth 14a and 16a are slightly rotated with the torque zero until the outer teeth 14a and 16a mesh with the inner tooth pin 3. This rotation angle is an angle corresponding to the size of the gap between the external teeth 14a, 16a and the internal tooth pin 3. As shown in FIG. 3, when the external teeth 14 a and 16 a are engaged with the internal tooth pin 3, the torsion angle of the carrier 4 becomes a magnitude corresponding to the magnitude of the applied torque. As described above, the carrier 4 can be rotated while the torque is zero at a backlash angle corresponding to the size of the gap, and the magnitude of the backlash angle affects the positioning accuracy (stopping accuracy) of the robot. Therefore, in general, the shapes of the outer cylinder and the swing gear are set so that the backlash angle is about 1 minute (1 / 60th of a degree).
　これに対し、本実施形態の歯車装置１では、使用前の状態でバックラッシ角度が２分～３分になるように設定されている。すなわち、外筒２は、外気に放熱したり、締結される相手部材（例えばロボットのベース）に放熱するため、揺動歯車１４，１６及び内歯ピン３に比べて熱膨張量が小さい。このため、歯車装置１を作動させると、揺動歯車１４，１６の外歯１４ａ，１６ａと内歯ピン３との間のすき間（クリアランス）が狭くなる傾向にある。これにより、本実施形態の歯車装置１では、使用時の昇温により、クリアランスが使用前に比べて狭くなったときに、バックラッシ角度が略１分となる設定となっている。例えば内歯ピン３の外径を従来のものに比べて小さくすることにより、発熱によるクリアランス減少分に相当するクリアランスを予め付加しておくことができる。 On the other hand, in the gear device 1 of the present embodiment, the backlash angle is set to 2 to 3 minutes before use. That is, the outer cylinder 2 radiates heat to the outside air or radiates heat to a mating member (for example, the base of the robot), and therefore has a smaller amount of thermal expansion than the rocking gears 14 and 16 and the internal tooth pin 3. For this reason, when the gear device 1 is operated, the clearance (clearance) between the external teeth 14a, 16a of the rocking gears 14, 16 and the internal tooth pin 3 tends to be narrowed. Thereby, in the gear apparatus 1 of this embodiment, when the clearance becomes narrower than before use due to the temperature rise during use, the backlash angle is set to approximately 1 minute. For example, by reducing the outer diameter of the internal tooth pin 3 as compared with the conventional one, a clearance corresponding to the clearance reduction due to heat generation can be added in advance.
　図４は、使用時の発熱に伴うバックラッシ角度についての使用前の状態からの変化を示している。使用時には、外筒２の温度は７０～８０℃程度にまで上昇する。したがって、使用前の状態（例えば２０℃）でバックラッシ角度が２分である場合、７０℃でのバックラッシ角度が１分未満（約０．６分）となる。また、使用前の状態でバックラッシ角度が３分である場合には、７０℃でのバックラッシ角度が約１．２分となる。したがって、使用前の状態でのバックラッシ角度が２～３分（２分以上で、且つ３分以内）であれば、使用中のバックラッシ角度は約１分（０．６分以上で、且つ１．２分以内）となる。特に、本実施形態では、８０ｒｐｍ～２００ｒｐｍで使用される歯車装置となっているので、この温度に達するまでに余り時間がかからず、バックラッシの大きな状態で使用されることは少ない。なお、図４において、使用前の状態でのバックラッシ角度が３分の場合のデータは推測値である。 FIG. 4 shows a change from the state before use of the backlash angle due to heat generation during use. At the time of use, the temperature of the outer cylinder 2 rises to about 70 to 80 ° C. Therefore, when the backlash angle is 2 minutes before use (for example, 20 ° C.), the backlash angle at 70 ° C. is less than 1 minute (about 0.6 minutes). When the backlash angle is 3 minutes before use, the backlash angle at 70 ° C. is about 1.2 minutes. Therefore, if the backlash angle in the state before use is 2 to 3 minutes (2 minutes or more and within 3 minutes), the backlash angle during use is about 1 minute (0.6 minutes or more and 1. Within 2 minutes). In particular, in the present embodiment, since the gear device is used at 80 rpm to 200 rpm, it does not take much time to reach this temperature, and it is rarely used in a state of large backlash. In FIG. 4, data when the backlash angle in the state before use is 3 minutes is an estimated value.
　図４に示す比較例１のように、使用前の状態でのバックラッシ角度が１分の場合には、６０℃以上において、温度上昇によってもバックラッシ角度が下がらず、下げ止まっている。これは、６０℃付近で既にすき間がなくなってしまった状態を表していると推測される。一方、比較例２は、使用前の状態でのバックラッシ角度が６分の場合を示している。この比較例２では、外筒の温度が上昇した使用中においてもバックラッシ角度が略４分あり、ロボットの位置決め精度（停止精度）が悪いものとなる。 As in Comparative Example 1 shown in FIG. 4, when the backlash angle in the state before use is 1 minute, at 60 ° C. or higher, the backlash angle does not decrease even when the temperature rises, and has stopped decreasing. This is presumed to represent a state in which the gap has already disappeared around 60 ° C. On the other hand, the comparative example 2 has shown the case where the backlash angle in the state before use is 6 minutes. In Comparative Example 2, the backlash angle is about 4 minutes even during use when the temperature of the outer cylinder is increased, and the positioning accuracy (stopping accuracy) of the robot is poor.
　以上説明したように、本実施形態の歯車装置１では、バックラッシ角度が２分～３分に設定されているので、歯車装置１を作動させることによって揺動歯車１４，１６が昇温して膨張した場合に、外筒２に対するキャリア４のバックラッシ角度を略１分にすることができる。したがって、使用時においては外筒２に対するキャリア４のバックラッシ角度が過大になることがないため、偏心揺動型歯車装置１として停止精度を維持することができる。しかも、揺動歯車１４，１６の歯面の面圧が高くなることを抑制することができるため、揺動歯車１４，１６の寿命の低減を抑制することができる。すなわち、実使用時におけるバックラッシ角度の最適化を図ることができる。 As described above, in the gear device 1 of the present embodiment, the backlash angle is set to 2 to 3 minutes, so that when the gear device 1 is operated, the rocking gears 14 and 16 are heated to expand. In this case, the backlash angle of the carrier 4 with respect to the outer cylinder 2 can be reduced to about 1 minute. Therefore, when used, the backlash angle of the carrier 4 with respect to the outer cylinder 2 does not become excessive, so that the stopping accuracy of the eccentric oscillating gear device 1 can be maintained. And since it can suppress that the surface pressure of the tooth surface of rocking gears 14 and 16 becomes high, reduction of the life of rocking gears 14 and 16 can be controlled. That is, it is possible to optimize the backlash angle during actual use.
　また本実施形態では、外筒２とキャリア４との間の相対回転数が８０ｒｐｍ～２００ｒｐｍである。この態様では、８０ｒｐｍ～２００ｒｐｍという高速領域での回転数で使用されるため、使用開始後の揺動歯車１４，１６の昇温も早い。したがって、使用開始後に通常のバックラッシ角度（略１分）になるまでの時間も短く、暖機運転の時間を短く又は無くすことができる。 In this embodiment, the relative rotational speed between the outer cylinder 2 and the carrier 4 is 80 rpm to 200 rpm. In this embodiment, since the rotation speed is used in a high speed region of 80 rpm to 200 rpm, the temperature of the oscillating gears 14 and 16 after the start of use is fast. Therefore, the time until the normal backlash angle (approximately 1 minute) is reached after the start of use is also short, and the warm-up operation time can be shortened or eliminated.
　なお、本発明は、前記実施形態に限られるものではなく、その趣旨を逸脱しない範囲で種々変更、改良等が可能である。例えば、前記実施形態では、２つの揺動歯車１４，１６が設けられた構成としたが、これに限られるものではない。例えば、１つの揺動歯車が設けられる構成、又は３つ以上の揺動歯車が設けられる構成であってもよい。 Note that the present invention is not limited to the above-described embodiment, and various modifications and improvements can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, the two swing gears 14 and 16 are provided. However, the present invention is not limited to this. For example, a configuration in which one oscillating gear is provided or a configuration in which three or more oscillating gears are provided may be employed.
　前記実施形態では、入力軸８がキャリア４の中央部に配設され、複数のクランク軸１０が入力軸８の周囲に配設されている。しかし、この構成に限られるものではない。例えば、クランク軸１０がキャリア４の中央部に配設されたセンタークランク式であってもよい。この場合、入力軸８がクランク軸１０に取り付けられた伝達歯車２０に噛み合うように設けられれば、入力軸８はどの位置に配設されていてもよい。 In the above embodiment, the input shaft 8 is disposed at the center of the carrier 4, and the plurality of crankshafts 10 are disposed around the input shaft 8. However, the configuration is not limited to this. For example, a center crank type in which the crankshaft 10 is disposed at the center of the carrier 4 may be used. In this case, as long as the input shaft 8 is provided so as to mesh with the transmission gear 20 attached to the crankshaft 10, the input shaft 8 may be disposed at any position.
　前記実施形態では、外筒２がロボットのベースに結合されるとともにキャリア４がロボットの旋回胴に結合され、かつ、キャリア４が外筒２に対して回動する構成となっている。しかし、この構成に限られるものではない。例えば、キャリア４がロボットのベースに結合されるとともに外筒２がロボットの旋回胴に結合され、外筒２がキャリア４に対して回動する構成としてもよい。 In the above embodiment, the outer cylinder 2 is coupled to the base of the robot, the carrier 4 is coupled to the revolving drum of the robot, and the carrier 4 rotates with respect to the outer cylinder 2. However, the configuration is not limited to this. For example, the carrier 4 may be coupled to the base of the robot and the outer cylinder 2 may be coupled to the swivel drum of the robot so that the outer cylinder 2 rotates with respect to the carrier 4.
　ここで、前記実施形態について概説する。 Here, the embodiment will be outlined.
　一般に偏心揺動型歯車装置の使用時には、外筒よりも揺動歯車の方が発熱によって高温となる。このため、外筒に配設された内歯と揺動歯車の歯部とのすき間は、使用中において、使用前に比べて狭くなる傾向にある。したがって、通常の偏心揺動型歯車装置のように、外筒に対する揺動歯車のバックラッシ角度が略１分に設定される場合には、揺動歯車の発熱によって前記すき間（遊び）が狭くなると、揺動歯車の歯面の面圧上昇に繋がり、その結果として疲労強度が低減してしまう。これに対し、本実施形態では、バックラッシ角度が２分～３分に設定されているので、偏心揺動型歯車装置を作動させることによって揺動歯車が昇温して膨張すると、外筒に対するキャリアのバックラッシ角度を略１分にすることができる。したがって、使用時においては外筒に対するキャリアのバックラッシ角度が過大になることがないため、偏心揺動型歯車装置として停止精度を維持することができる。しかも、揺動歯車の歯面の面圧が高くなることを抑制することができて、揺動歯車の寿命の低減を抑制することができる。 Generally, when an eccentric oscillating gear device is used, the oscillating gear becomes hotter than the outer cylinder due to heat generation. For this reason, the clearance between the internal teeth disposed on the outer cylinder and the tooth portion of the oscillating gear tends to be narrower during use than before use. Therefore, when the backlash angle of the oscillating gear with respect to the outer cylinder is set to approximately 1 minute as in a normal eccentric oscillating gear device, the clearance (play) becomes narrow due to heat generated by the oscillating gear. This leads to an increase in the surface pressure of the tooth surface of the oscillating gear, and as a result, the fatigue strength is reduced. On the other hand, in this embodiment, the backlash angle is set to 2 to 3 minutes. Therefore, when the eccentric gear device is operated to raise the temperature of the oscillation gear and expand, The backlash angle can be reduced to approximately 1 minute. Accordingly, since the backlash angle of the carrier with respect to the outer cylinder does not become excessive during use, the stopping accuracy can be maintained as the eccentric oscillating gear device. In addition, an increase in the surface pressure of the tooth surface of the oscillating gear can be suppressed, and a reduction in the life of the oscillating gear can be suppressed.
　ここで、前記外筒と前記キャリアとの間の相対回転数は、８０ｒｐｍ～２００ｒｐｍであってもよい。 Here, the relative rotational speed between the outer cylinder and the carrier may be 80 rpm to 200 rpm.
　この態様では、８０ｒｐｍ～２００ｒｐｍという高速領域での回転数範囲で使用されるため、使用開始後の揺動歯車の昇温も早い。したがって、使用開始後に通常のバックラッシ角度（略１分）になるまでの時間も短く、暖機運転の時間を短く又は無くすことができる。 In this embodiment, since the rotation speed is used in a high speed range of 80 rpm to 200 rpm, the temperature of the rocking gear rises quickly after the start of use. Therefore, the time until the normal backlash angle (approximately 1 minute) is reached after the start of use is also short, and the warm-up operation time can be shortened or eliminated.
　以上説明したように、本実施形態によれば、揺動歯車の歯面の面圧が上昇することを抑制することができるため、揺動歯車の寿命が短くなることを抑制することができる。 As described above, according to the present embodiment, it is possible to suppress an increase in the surface pressure of the tooth surface of the oscillating gear, and thus it is possible to suppress the life of the oscillating gear from being shortened.
　１　偏心揺動型歯車装置
　２　外筒
　３　内歯ピン
　４　キャリア
　６　主軸受
　１０　クランク軸
　１０ａ　第１偏心部
　１０ｂ　第２偏心部
　１０ｃ　軸本体
　１２ａ　第１クランク軸受
　１２ｂ　第２クランク軸受
　１４　第１揺動歯車
　１４ａ　外歯
　１６　第２揺動歯車
　１６ａ　外歯 DESCRIPTION OF SYMBOLS 1 Eccentric oscillation type gear apparatus 2 Outer cylinder 3 Internal tooth pin 4 Carrier 6 Main bearing 10 Crankshaft 10a 1st eccentric part 10b 2nd eccentric part 10c Shaft body 12a 1st crank bearing 12b 2nd crank bearing 14 1st oscillation Gear 14a External tooth 16 Second swing gear 16a External tooth

Claims (2)

  1. 　第１の部材と第２の部材との間で所定の回転数比で回転数を変換して駆動力を伝達する歯車装置であって、
    　偏心部と、
    　前記偏心部が挿入される挿通孔を有すると共に歯部を有する揺動歯車と、
    　前記第１の部材及び前記第２の部材の一方に取り付け可能に構成される外筒と、
    　前記第１の部材及び前記第２の部材の他方に取り付け可能に構成されるキャリアと、を備え、
    　前記外筒は、前記揺動歯車の前記歯部と噛み合う内歯を有しており、
    　前記キャリアは、前記揺動歯車を保持した状態で前記外筒の径方向内側に配置され、
    　前記外筒と前記キャリアとは、前記偏心部の回転に伴う前記揺動歯車の揺動によって同心状に互いに相対的に回転可能であり、
    　使用時における前記揺動歯車の熱膨張によって前記外筒に対する前記キャリアのバックラッシ角度が略１分になるように、前記バックラッシ角度は２分～３分に設定されている偏心揺動型歯車装置。     A gear device that transmits a driving force by converting a rotational speed at a predetermined rotational speed ratio between a first member and a second member,
    An eccentric part,
    An oscillating gear having an insertion hole into which the eccentric part is inserted and having a tooth part;
    An outer cylinder configured to be attachable to one of the first member and the second member;
    A carrier configured to be attachable to the other of the first member and the second member,
    The outer cylinder has inner teeth that mesh with the teeth of the swing gear,
    The carrier is disposed on the radially inner side of the outer cylinder while holding the swing gear,
    The outer cylinder and the carrier are concentrically rotatable relative to each other by the swinging of the swinging gear accompanying the rotation of the eccentric part,
    An eccentric oscillating gear device in which the backlash angle is set to 2 to 3 minutes so that the backlash angle of the carrier with respect to the outer cylinder becomes approximately 1 minute due to thermal expansion of the oscillating gear in use.
  2. 　前記外筒と前記キャリアとの間の相対回転数は、８０ｒｐｍ～２００ｒｐｍである請求項１に記載の偏心揺動型歯車装置。 The eccentric oscillating gear device according to claim 1, wherein a relative rotational speed between the outer cylinder and the carrier is 80 rpm to 200 rpm.
PCT/JP2013/004462 2012-08-24 2013-07-23 Eccentrically rocking-type gear device WO2014030292A1 (en)

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KR1020197023270A KR20190095559A (en) 2012-08-24 2013-07-23 Eccentrically rocking-type gear device
DE112013003689.4T DE112013003689B4 (en) 2012-08-24 2013-07-23 Orbital eccentric device and method for maintaining positioning accuracy
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TWI572795B (en) 2017-03-01
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JP5466739B2 (en) 2014-04-09
JP2014043874A (en) 2014-03-13
CN104583645B (en) 2016-04-27
TW201420921A (en) 2014-06-01
DE112013003689T5 (en) 2015-04-09
DE112013003689B4 (en) 2023-01-12
KR20190095559A (en) 2019-08-14
CN104583645A (en) 2015-04-29

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