JP2010065803A - Eccentrically oscillating gear device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an eccentrically oscillating gear device, capable of reducing the operation load for adjustment operation in assembling and the manufacturing cost while suppressing backlash in a rotating direction of a carrier. <P>SOLUTION: The eccentrically oscillating gear device includes a carrier 4 which rotates relatively to an outer cylinder 2 by transmitting oscillating rotation of a first external tooth gear 14 and a second external tooth gear 16 thereto; and a first crank bearing 12a and a second crank bearing 12b each of which supports a crankshaft 10 to be rotatable relative to the carrier 4. The carrier 4 includes a shaft part 4c inserted to shaft part insert holes 14d and 16d of both the external tooth gears 14 and 16 so as to transmit the oscillating rotation of both the gears 14 and 16, and each of the crank bearings 12a and 12b is formed of a deep groove ball bearing or cylindrical roller bearing. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an eccentric oscillating gear device.

  2. Description of the Related Art Conventionally, an eccentric oscillating gear device is known in which an output rotation decelerated from an input rotation is obtained by oscillating and rotating an external gear while meshing with an internal tooth of an outer cylinder by an eccentric portion of a crankshaft. (For example, refer to Patent Document 1).

  FIG. 5 shows a structure of an eccentric oscillating gear device according to a conventional example disclosed in Patent Document 1. In this conventional eccentric oscillating gear device, a plurality of crankshafts 104 are provided in the outer cylinder 102 so as to be rotatable around the respective axes, and each crankshaft 104 has two eccentric portions 104a arranged in the axial direction. , 104b. External gears 107a and 107b are attached to the eccentric portions 104a and 104b of the crankshaft 104, and the input shaft 109 is inserted into the through holes 108a and 108b in the center of the external gears 107a and 107b. A plurality of input gears 110 are provided so as to mesh with a gear portion 109 a provided at the distal end portion of the input shaft 109, and each input gear 110 is externally fitted to the end portion of each crankshaft 104. ing.

  A carrier 112 is provided in the outer cylinder 102 so as to be rotatable relative to the outer cylinder 102. The carrier 112 has a pair of end plate portions 112a and 112b disposed on both sides in the axial direction of the external gears 107a and 107b, and a plurality of shaft portions 112c connecting the end plate portions 112a and 112b. Each shaft portion 112c is inserted into a corresponding one of the plurality of insertion holes 108c provided in the external gears 107a and 107b. Each shaft portion 112c is disposed such that the inner surface of the insertion hole 108c does not contact the outer surface of the shaft portion 112c when the external gears 107a and 107b are swung. Each crankshaft 104 is rotatably supported with respect to the carrier 112 by crank bearings 114a and 114b at both axial ends.

  When rotation is input from the input shaft 109 to each crankshaft 104 via each input gear 110, each external gear 107a, 107b is interlocked with the eccentric rotation of the eccentric portions 104a, 104b of each crankshaft 104. Then, while rotating and rotating while meshing with the inner teeth 102a on the inner surface of the outer cylinder 102, the rotating rotations of the external gears 107a and 107b are transmitted to the carrier 112 via the crankshaft 104 and the crank bearings 114a and 114b. The carrier 112 rotates relative to the outer cylinder 102, and a decelerated output rotation is obtained from the carrier 112.

In this conventional eccentric oscillating gear device, in order to suppress backlash in the rotation direction of the carrier 112 when rotation is transmitted from each crankshaft 104 to the carrier 112 via the crank bearings 114a and 114b, Tapered bearings are used as the bearings 114a and 114b. That is, the taper bearing can eliminate the rattling that may occur in the bearing by adjusting the preload, and as a result, the backlash in the rotational direction of the carrier 112 caused by the rattling in the bearing. (Rattle) can be reduced.
JP 2005-325865 A

  However, the conventional eccentric oscillating gear device has problems that adjustment work during assembly takes time and manufacturing costs increase.

  That is, in the above-described conventional eccentric oscillating gear device, it is necessary to perform the preload adjustment work of the crank bearings 114a and 114b. Therefore, the adjustment work at the time of assembling the gear device takes time and the crank bearings 114a and 114b are used. Since the taper bearing used is relatively expensive, the manufacturing cost of the gear device increases.

  The present invention has been made to solve the above-described problems, and its purpose is to reduce the work load and manufacturing cost for adjustment work during assembly while suppressing backlash in the rotation direction of the carrier. Another object of the present invention is to provide an eccentric oscillating gear device that can be used.

  In order to achieve the above object, an eccentric oscillating gear device according to the present invention has an outer cylinder having inner teeth provided on an inner surface thereof, a circumferentially spaced apart inner cylinder, and an eccentric portion. A plurality of crankshafts rotatably provided around the respective shafts, an input gear provided on each crankshaft for inputting rotation to the provided crankshaft, and the eccentricity of each crankshaft An external gear having a through hole at a position shifted outward from the center of swinging, and being rotated in conjunction with the eccentric rotation of the eccentric part while meshing with the inner teeth, and the outer cylinder And a carrier that rotates relative to the outer cylinder by transmitting the oscillating rotation of the external gear, and the crankshaft is rotatable with respect to the carrier. Supporting clan And the carrier has a shaft portion that is inserted into the through-hole of the external gear so that the oscillating rotation of the external gear is transmitted, and the crank bearing is a deep groove ball bearing or a cylinder. Consists of roller bearings.

  In this eccentric oscillating gear device, when rotation is input to the input gear from the outside, the rotation can be transmitted from the input gear to the crankshaft to rotate the crankshaft, and the eccentric portion of the crankshaft The external gear can be swung and rotated in conjunction with the eccentric rotation. In this eccentric oscillating gear device, the rotation of the external gear can be transmitted from the crankshaft to the carrier via the crank bearing, but the rotation of the external gear can be transmitted to the carrier through the shaft portion. Even if there is shakiness in the crank bearing, it is possible to prevent the carrier from causing backlash in the rotational direction due to the shakiness. Due to this, instead of the conventionally used taper bearing, a deep groove ball bearing or a cylindrical roller bearing that does not require preload adjustment work and is less expensive than a taper bearing is used as a crank bearing. Can do. That is, the deep groove ball bearing or the cylindrical roller bearing is unavoidably caused by some shakiness unlike the tapered bearing. However, in this configuration, since rotation is transmitted to the carrier through the shaft portion, even if there is some backlash in the crank bearing, there is no relation to the backlash of the carrier. For this reason, since some shakiness in a crank bearing can be permitted, it is not necessary to perform preload adjustment work for eliminating shakiness like a taper bearing, and it has a feature that it is relatively inexpensive. Deep groove ball bearings or cylindrical roller bearings can be used as crank bearings. Therefore, in this eccentric oscillating gear device, it is possible to reduce the work burden and the manufacturing cost for the adjustment work during assembly while suppressing backlash in the rotation direction of the carrier.

  In the eccentric oscillating gear device, the shaft portion is inserted with play in the through-hole of the external gear, and one of the outer surfaces of the shaft portion is rotated during the oscillating rotation of the external gear. It is preferable that the portion is disposed so as to contact the inner surface of the through hole.

  If comprised in this way, rotation of an external gear can be transmitted to a career | carrier as rotation around the axis | shaft, releasing the rocking | fluctuation of an external gear by the play of the shaft part in the through-hole of an external gear.

  In the eccentric oscillating gear device, the carrier has a pair of sandwiching portions disposed on both sides in the axial direction of the external gear, and the pair of sandwiching portions and the shaft portion include the pair of sandwiching portions. It is preferable that they are detachably coupled to each other with the shaft portion sandwiched therebetween.

  When the shaft portion is non-detachably coupled to one of the pair of sandwiching portions, the shaft portion is worn when the shaft portion is worn as the swinging rotation of the external gear is transmitted to the carrier through the shaft portion. And the sandwiching part connected to it must be replaced as a unit. On the other hand, in this structure, since a shaft part and a pair of clamping part are mutually detachable, when a shaft part is worn out, only a shaft part can be replaced | exchanged. As a result, in this configuration, compared to the case where the shaft portion and the sandwiching portion are detachably coupled, the replacement portion can be reduced, and the cost required for the replacement can be reduced.

  In this case, the pair of sandwiching portions and the shaft portion are fastened to each other by bolts, and a bolt hole for screwing the bolt penetrates in one of the pair of sandwiching portions in the axial direction. It is preferable that it is provided.

  According to this structure, when the counterpart member that is driven by rotation of the carrier is attached to the outside of the one sandwiched portion provided with the bolt hole, the counterpart member is utilized using the bolt hole of the one sandwiched portion. The bolts on the member side can be screwed together to fasten one of the sandwiched portions and the mating member. Accordingly, it is not necessary to separately provide a bolt hole for fastening the mating member in one of the sandwiched portions, and it is possible to reduce the labor for forming the bolt hole, and the bolt hole in one of the sandwiched portions. It is possible to eliminate the need for a space.

  As described above, according to the eccentric oscillating gear device of the present invention, it is possible to reduce work load and manufacturing cost for adjustment work during assembly while suppressing backlash in the rotation direction of the carrier.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a sectional view along an axial direction of an eccentric oscillating gear device according to an embodiment of the present invention, and FIG. 2 is an II-II in FIG. 1 of the eccentric oscillating gear device according to this embodiment. It is sectional drawing along a line. First, with reference to FIG.1 and FIG.2, the structure of the eccentric rocking | fluctuation type gear apparatus by this embodiment is demonstrated.

  The eccentric oscillating gear device according to the present embodiment (hereinafter simply referred to as a gear device) is applied as a speed reducer to a turning portion of a turning barrel or arm joint of a robot or a turning portion of various machine tools, for example. The first external gear 14 is oscillated and rotated in conjunction with the first eccentric portion 10a of the crankshaft 10, and the second external gear 16 is oscillated and rotated in conjunction with the second eccentric portion 10b. It is comprised so that the output rotation decelerated from may be obtained. In the following description of the present embodiment, an example in which a gear device is applied to a robot arm joint will be described.

  Specifically, as shown in FIG. 1, the gear device of the present embodiment includes an outer cylinder 2, an internal tooth pin 3, a carrier 4, a carrier bearing 6, an input shaft 8, a crankshaft 10, A first crank bearing 12a, a second crank bearing 12b, an input gear 13, a first external gear 14, a second external gear 16, a first roller bearing 18a, and a second roller bearing 18b are provided. ing.

  The outer cylinder 2 functions as a case constituting the outer surface of the gear device, and is formed in a substantially cylindrical shape. A flange 2a is provided on the outer surface of the outer cylinder 2, and the flange 2a is fastened to one arm (not shown) at the arm joint of the robot. On the inner surface of the outer cylinder 2, a large number of internal teeth pins 3 are provided as shown in FIG. This internal tooth pin 3 is included in the concept of the internal tooth of the present invention. Each internal tooth pin 3 is arranged in a posture extending in the axial direction of the outer cylinder 2, and these are arranged at equal intervals in the circumferential direction of the outer cylinder 2.

  As shown in FIG. 1, the carrier 4 is accommodated in the outer cylinder 2 in a state of being coaxial with the outer cylinder 2, and can be relatively rotated around the same axis with respect to the outer cylinder 2. It has become. The carrier 4 is fixed to the other arm portion 50 at the arm joint of the robot. When the carrier 4 and the outer cylinder 2 are relatively rotated, the one arm portion and the other arm constituting the arm joint of the robot. The arm portion 50 is adapted to pivot on the same axis.

  Specifically, the carrier 4 is supported so as to be relatively rotatable with respect to the outer cylinder 2 by a pair of carrier bearings 6 that are provided apart from each other in the axial direction.

  The carrier 4 includes a first sandwiching portion 4a, a second sandwiching portion 4b, and three shaft portions 4c.

  The first sandwiching portion 4 a is formed in a substantially disc shape, and is disposed in the outer cylinder 2 in the vicinity of one end portion in the axial direction of the outer cylinder 2 and supported by the one carrier bearing 6. . The other arm portion 50 is attached to the first sandwiching portion 4a. The first sandwiching portion 4a is provided with a central portion through hole 4d penetrating in the axial direction at the radial center portion thereof, and three crankshaft mounting holes 4e (hereinafter referred to as the center portion through hole 4d). The mounting holes 4e are simply provided in the circumferential direction at equal intervals. Since each mounting hole 4e is formed with a bottom and does not penetrate the first sandwiching portion 4a, the sealing of each mounting hole 4e is unnecessary. Further, the first sandwiching portion 4a is provided with three bolt holes 4f for screwing bolts 4r, which will be described later, so as to penetrate in the axial direction. It arrange | positions at intervals and is arrange | positioned between each said attachment holes 4e. A bolt 4r described later is screwed into the bolt hole 4f from the inner side in the axial direction of the outer cylinder 2 to a predetermined depth, and the other arm portion 50 is attached to the first sandwiching portion 4a. The mounting bolt 52 of the arm portion 50 can be screwed into the bolt hole 4f from the side opposite to the bolt 4r.

  The second sandwiching portion 4 b is formed in a substantially disc shape, and is disposed in the outer cylinder 2 in the vicinity of the other end portion in the axial direction of the outer cylinder 2. The second sandwiching portion 4 b is supported by the other carrier bearing 6. In the outer cylinder 2, a space surrounded by both end faces of the second sandwiching part 4b and the first sandwiching part 4a facing each other and the inner surface of the outer cylinder 2 is formed. A first external gear 14 and the second external gear 16 are arranged. That is, the second sandwiching portion 4b and the first sandwiching portion 4a are arranged separately on both axial sides of the external gears 14 and 16. In the second sandwiching portion 4b, a central portion through hole 4g having the same diameter as the central through hole 4d of the first sandwiching portion 4a is provided at the central portion in the radial direction so as to penetrate in the axial direction. Around the central through hole 4g, three crankshaft mounting holes 4h (hereinafter simply referred to as mounting holes 4h) are provided at positions corresponding to the three mounting holes 4e of the first sandwiching portion 4a. Since each mounting hole 4h is formed with a bottom and does not penetrate through the second sandwiching portion 4b, sealing of each mounting hole 4h is unnecessary. In addition, in the second sandwiching portion 4b, three fitting holes 4i for fitting the heads of bolts 4r described later are provided so as to penetrate in the axial direction, and these three fitting holes 4i are It arrange | positions in the position corresponding to the three bolt holes 4f of the said 1st clamping part 4a.

  As shown in FIG. 1, the three shaft portions 4c are sandwiched between the first sandwiching portion 4a and the second sandwiching portion 4b, and are equally spaced in the circumferential direction of the outer cylinder 2 as shown in FIG. Is provided. Each shaft part 4c is arrange | positioned with the attitude | position extended in parallel with the axial direction of the outer cylinder 2, and has a circular cross section. Each shaft portion 4c includes a shaft pin 4k and a bush 4m. The shaft pin 4k has a bolt insertion hole 4n penetrating in the axial direction. The bush 4m is formed in a cylindrical shape, and is attached to the shaft pin 4k so as to cover the outer periphery of the shaft pin 4k. And the axial direction both ends of the shaft pin 4k are not covered with the bush 4m, but are exposed. One end of the shaft pin 4k is fitted in a recess 4p provided in the first sandwiching portion 4a, and the other end of the shaft pin 4k is fitted in a recess 4q provided in the second sandwiching portion 4b. Yes. Thereby, positioning of each shaft part 4c is possible.

  The first sandwiching portion 4a, the second sandwiching portion 4b, and each shaft portion 4c are connected to each shaft portion 4c with the first sandwiching portion 4a and the second sandwiching portion 4b sandwiching each shaft portion 4c therebetween. It is united by being fastened by a bolt 4r at a corresponding location. In this state, the head of each bolt 4r is fitted in the corresponding fitting hole 4i of the second sandwiching portion 4b, and the axially intermediate portion thereof is inserted into the bolt insertion hole 4n of the corresponding shaft portion 4c. The tip portion is inserted and screwed into the corresponding bolt hole 4f of the first sandwiching portion 4a. In addition, if the fastening by each volt | bolt 4r is cancelled | released, it will become possible to isolate | separate the 1st clamping part 4a, the 2nd clamping part 4b, and each shaft part 4c from each other.

  The input shaft 8 is inputted with rotation by an external drive motor (not shown), and the tip portion of the input shaft 8 passes through the central through hole 4g of the second sandwiching portion 4b. It is inserted in a space surrounded by 4a and the second sandwiching portion 4b. 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 its axis. A gear portion 8 a is provided on the outer peripheral surface of the distal end portion of the input shaft 8.

  Three crankshafts 10 are provided in the outer cylinder 2, and each crankshaft 10 includes a corresponding mounting hole 4e of the first sandwiching portion 4a and a corresponding mounting hole 4h of the second sandwiching portion 4b. Are arranged around the input shaft 8 in the outer cylinder 2 at equal intervals in the circumferential direction.

  Specifically, one end of each crankshaft 10 in the axial direction is attached to the corresponding attachment hole 4e of the first sandwiching portion 4a via the first crank bearing 12a. The other end portion in the axial direction is attached to the corresponding attachment hole 4h of the second sandwiching portion 4b via the second crank bearing 12b. That is, each crankshaft 10 is supported by both crank bearings 12a and 12b so as to be rotatable about the respective axes with respect to the carrier 4. Both the first crank bearing 12a and the second crank bearing 12b are deep groove ball bearings. This deep groove ball bearing is somewhat inexpensive, although it causes some backlash. After fitting into the mounting hole 4e (4h), the end of the crankshaft 10 is inserted inside the inner ring member. It has the feature that it does not require troublesome adjustment work.

  And the crankshaft 10 has the 1st eccentric part 10a and the 2nd eccentric part 10b arrange | positioned so that it may arrange in the axial direction between the both ends supported by both crank bearings 12a and 12b at intervals. Yes. The first eccentric portion 10a and the second eccentric portion 10b are each formed in a cylindrical shape eccentric from the axis of the crankshaft 10 by a predetermined amount of eccentricity, and have a predetermined angle phase difference therebetween. Has been placed. Further, a fitted portion 10c is provided in a portion of the crankshaft 10 located between the first eccentric portion 10a and the second eccentric portion 10b.

  The input gear 13 is for receiving the rotation of the gear portion 8a of the input shaft 8 and inputting the rotation to each crankshaft 10, and comprises a spur gear. A total of three input gears 13 are provided corresponding to the three crankshafts 10, and each input gear 13 is externally fitted to the fitted portion 10c of the corresponding crankshaft 10, and It is united. The input gear 13 may be formed integrally with the crankshaft 10. The three input gears 13 are arranged between the first external gear 14 and the second external gear 16 in a space surrounded by the first sandwiching portion 4a and the second sandwiching portion 4b in the outer cylinder 2. It is arranged. Each input gear 13 has an external tooth 13a that meshes with the gear portion 8a of the input shaft 8, and rotation is transmitted from the gear portion 8a of the input shaft 8 so that the shaft is integrally formed with the crankshaft 10. It is designed to rotate around.

  As described above, the first external gear 14 is disposed in the space surrounded by the first sandwiching portion 4 a and the second sandwiching portion 4 b in the outer cylinder 2, and the first eccentricity of each crankshaft 10. The first roller bearing 18a is attached to the portion 10a. When each crankshaft 10 is rotated, the first eccentric portion 10a is interlocked with the eccentric rotation of the first eccentric portion 10a while meshing with the inner tooth pin 3 on the inner surface of the outer cylinder 2. It is designed to rotate dynamically.

  The first external gear 14 is provided with external teeth 14a, an external gear central portion through hole 14b, three first eccentric portion insertion holes 14c, and three shaft portion insertion holes 14d. The shaft portion insertion hole 14d is included in the concept of the through hole of the present invention.

  The external teeth 14 a mesh with the internal tooth pins 3, and are provided in a number slightly smaller than the number of the internal tooth pins 3.

  The external gear central portion through hole 14 b is provided in the radial central portion of the first external gear 14.

  The three first eccentric portion insertion holes 14c are arranged at equal intervals in the circumferential direction around the central portion through hole 14b in the first external gear 14. The first eccentric portion 10a of each crankshaft 10 is inserted into each first eccentric portion insertion hole 14c in a state where the first roller bearing 18a is interposed.

  The three shaft portion insertion holes 14d are respectively disposed at positions shifted by a predetermined distance radially outward from the center of oscillation of the first external gear 14. Further, the three shaft portion insertion holes 14d are arranged at equal intervals in the circumferential direction around the central portion through hole 14b, and each shaft portion insertion hole 14d has the three first eccentric portion insertion holes 14c. It is arrange | positioned in the position between, respectively. Each shaft portion insertion hole 14d is formed in a circular shape, and the corresponding shaft portion 4c of the carrier 4 is inserted into each shaft portion insertion hole 14d with play. The shaft portion 4c is disposed so that a part of the outer surface of the shaft portion 4c always contacts the inner surface of the shaft portion insertion hole 14d when the first external gear 14 rotates and rotates. Thus, when the first external gear 14 swings and rotates, the swing of the first external gear 14 is released by the play of each shaft portion 4c in each shaft portion insertion hole 14d. The rotation of the gear 14 is transmitted as rotation around the shaft from the inner surface of each shaft portion insertion hole 14d to the carrier 4 through each shaft portion 4c.

  The second external gear 16 is arranged side by side in the axial direction with the first external gear 14 in a space surrounded by the first sandwiching portion 4 a and the second sandwiching portion 4 b in the outer cylinder 2. In addition, it is attached to the second eccentric portion 10b of each crankshaft 10 via a second roller bearing 18b, and the inner surface of the outer cylinder 2 is interlocked with the eccentric rotation of the second eccentric portion 10b when each crankshaft 10 rotates. Oscillating and rotating while meshing with the internal tooth pin 3. Due to the fact that the second external gear 16 is attached to the second eccentric portion 10b having a phase difference with the first eccentric portion 10a, the first external gear 14 attached to the first eccentric portion 10a and It swings and rotates with a phase difference. The second external gear 16 is configured in the same manner as the first external gear 14.

  Next, the operation of the gear device according to the present embodiment will be described.

  First, the input shaft 8 is rotated by driving a drive motor (not shown), whereby rotation is input to each input gear 13 from the gear portion 8a of the input shaft 8. Thereby, each crankshaft 10 is rotated with respect to the carrier 4 while being supported by the first crank bearing 12a and the second crank bearing 12b together with the input gear 13, and accordingly, the first eccentric portion 10a of each crankshaft 10 and The second eccentric portion 10b rotates eccentrically. In conjunction with the eccentric rotation of the first eccentric portion 10a, the first external gear 14 swings and rotates while meshing with the internal tooth pin 3 on the inner surface of the outer cylinder 2, and in conjunction with the eccentric rotation of the second eccentric portion 10b. Thus, the second external gear 16 swings and rotates while meshing with the internal tooth pin 3 on the inner surface of the outer cylinder 2. At this time, the first external gear 14 and the second external gear 16 swing and rotate while having a phase difference. In the present embodiment, each crankshaft 10 thus transmits only the eccentric rotational drive to the first external gear 14 and the second external gear 16.

  Then, the swinging rotation of the first external gear 14 and the second external gear 16 is transmitted to the carrier 4 through each shaft portion 4c. At this time, rotation is transmitted to the shaft portion 4c from the portion of the inner surface of the shaft portion insertion holes 14d, 16d of both the external gears 14, 16 that is in contact with the outer surface of the shaft portion 4c, and the both external gears 14, 16 are also transmitted. Is released by the play of the shaft portion 4c in the shaft portion insertion holes 14d, 16d. Then, when the rotation is transmitted to the carrier 4, the carrier 4 rotates relative to the outer cylinder 2 at a rotational speed decelerated from the input rotation. In the present embodiment, the rotation drive transmission from the first external gear 14 and the second external gear 16 to the carrier 4 is thus performed through each shaft portion 4 c of the carrier 4. Then, each shaft portion 4c of the carrier 4 is in contact with the inner surface of each shaft portion insertion hole 14d, 16d of both external gears 14, 16 having different rotational phases, so that the carrier 4 is back in its rotation direction. The shaft portions 4c are held by both external gears 14 and 16 so that rush does not occur.

  As described above, in this embodiment, when rotation is input from the outside to each input gear 13 through the input shaft 8, the rotation is transmitted from each input gear 13 to each crankshaft 10 to be transmitted to each crankshaft 10. And the first external gear 14 and the second external gear 16 are oscillated and rotated in conjunction with the eccentric rotation of the first eccentric portion 10a and the second eccentric portion 10b of each crankshaft 10. be able to. In this embodiment, the rotations of the external gears 14 and 16 are not transmitted from the respective crankshafts 10 to the carrier 4 via the first crank bearing 12a and the second crank bearing 12b, but instead of the external gears 14. , 16 can be transmitted to the carrier 4 through each shaft portion 4c, so that even if there is rattling in the first crank bearing 12a and the second crank bearing 12b, the carrier is caused by the rattling. 4 can prevent backlash in the rotational direction. As a result, instead of the conventionally used taper bearing, a deep groove ball bearing that does not require preload adjustment work and is less expensive than the taper bearing is used as the first crank bearing 12a and the second crank bearing. It can be used as the bearing 12b. That is, unlike the taper bearing, the deep groove ball bearing is unavoidably caused by some shakiness, but in the present embodiment, since the rotation is transmitted to the carrier 4 through each shaft portion 4c, the first crank bearing 12a Even if there is some backlash in the second crank bearing 12b, it does not relate to the backlash of the carrier 4. For this reason, since some shakiness in the 1st crank bearing 12a and the 2nd crank bearing 12b can be permitted, it is not necessary to perform preload adjustment work for eliminating shakiness like a taper bearing. Deep groove ball bearings having the feature of being relatively inexpensive can be used as the first crank bearing 12a and the second crank bearing 12b. Therefore, in the present embodiment, it is possible to reduce the work load and the manufacturing cost for the adjustment work during assembly while suppressing backlash in the rotation direction of the carrier 4.

  In the present embodiment, each shaft portion 4c of the carrier 4 is inserted in a state where there is play in the corresponding shaft portion insertion holes 14d, 16d of both external gears 14, 16, and both external gears Since the part of the outer surface of each shaft portion 4c is always in contact with the inner surface of the corresponding shaft portion insertion hole 14d, 16d during the swing rotation of the shafts 14, 16, both the external gears 14, 16 The rotation of the external gears 14 and 16 can be transmitted to the carrier 4 through each shaft portion 4c as rotation about its axis while releasing the swing of the shaft by the play of the shaft portion 4c in the shaft portion insertion holes 14d and 16d. .

  Further, in the present embodiment, the first sandwiching portion 4a, the second sandwiching portion 4b and the shaft portion 4c of the carrier 4 are mutually connected by the bolt 4r with the sandwiching portions 4a and 4b sandwiching the shaft portion 4c therebetween. It is fastened detachably. When the shaft portion 4c is detachably coupled to one of the sandwiching portions 4a and 4b, the rotation of the first external gear 14 and the second external gear 16 is transmitted to the carrier 4 through the shaft portion 4c. Accordingly, when the shaft portion 4c is worn, the shaft portion 4c and the sandwiching portion coupled to the shaft portion 4c must be replaced as a unit. On the other hand, in this embodiment, since the shaft part 4c and the both sandwiching parts 4a and 4b are detachable from each other, only the shaft part 4c can be exchanged when the shaft part 4c is worn. As a result, in this embodiment, compared with the case where the shaft portion 4c and the sandwiching portion 4a or 4b are detachably coupled, the replacement portion can be reduced, and the cost required for the replacement can be reduced. .

  Moreover, in this embodiment, since the bolt hole 4f is provided in the 1st clamping part 4a so that it may penetrate in an axial direction, the said other arm part 50 as a partner member is outside the 1st clamping part 4a. When attaching to the first arm 4, the first sandwiching portion 4 a and the other arm portion 50 can be fastened by screwing the mounting bolt 52 of the other arm portion 50 using the bolt hole 4 f. Accordingly, it is not necessary to separately provide a bolt hole for fastening the other arm portion 50 in the first sandwiching portion 4a, and the labor for forming the bolt hole can be reduced, and the first sandwiching portion can be reduced. The space for providing the bolt hole in 4a can be made unnecessary.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes meanings equivalent to the scope of claims for patent and all modifications within the scope.

  For example, one end portion of the crankshaft 10 protrudes from the second sandwiching portion 4b of the carrier 4 as in a modification of the above-described embodiment shown in FIG. While the part 10d is provided, the input gear 13 may be externally fitted to the fitted part 10d.

  Specifically, in this modified example, the mounting hole 4e is not provided in the first sandwiching portion 4a, the first crank bearing 12a is not provided, and the first crank bearing 10 is further provided with the first pinion portion 4a. A portion supported by the crank bearing 12a is also not provided. On the other hand, the second sandwiching portion 4b is provided with three crankshaft mounting holes 4s (hereinafter referred to as mounting holes 4s) instead of the three mounting holes 4h. Each mounting hole 4s is provided so as to penetrate the second sandwiching portion 4b in the axial direction. One end of each crankshaft 10 protrudes outside the second sandwiching portion 4b through the corresponding mounting hole 4s, and a fitted portion 10d is provided at the end of the protruding crankshaft 10. That is, the fitted portion 10c as in the above embodiment is not provided between the first eccentric portion 10a and the second eccentric portion 10b of each crankshaft 10. The input gear 13 is externally fitted to the fitted portion 10d by sprue coupling. That is, in this modification, each input gear 13 is disposed outside the carrier 4 and meshed with the gear portion 8a of the input shaft 8 at that position.

  A crank bearing 12c made of a deep groove ball bearing is provided in the mounting hole 4s, and a portion of the crankshaft 10 positioned between the second eccentric portion 10b and the fitted portion 10d is rotated by the crank bearing 12c. Supported as possible. In this modification, the crankshaft 10 is supported with respect to the carrier 4 so as to be rotatable around the single crank bearing 12c.

  Moreover, in this modification, as shown in FIG. 4, the shaft part insertion hole 14d of the 1st external gear 14 is each provided between each 1st eccentric part insertion hole 14c, and a total of six are provided. Yes. The second external gear 16 is also provided with a total of six shaft portion insertion holes 16 d in the same form as the shaft portion insertion holes 14 d of the first external gear 14. A total of six shaft portions 4c of the carrier 4 are provided corresponding to the shaft portion insertion holes 14d and 16d, and each shaft portion 4c is inserted through the corresponding shaft portion insertion holes 14d and 16d, respectively. .

  Also in this modified example, each crankshaft 10 transmits only the eccentric rotational drive to the first external gear 14 and the second external gear 16, and from the first external gear 14 and the second external gear 16. Transmission of rotation driving to the carrier 4 is performed through each shaft portion 4 c of the carrier 4. The configuration other than the above according to this modification is the same as the configuration according to the above embodiment.

  In this modified example, while suppressing backlash in the rotation direction of the carrier 4, it is possible to obtain the same effect as in the above embodiment that the work burden and the manufacturing cost for the adjustment work at the time of assembly can be reduced. Other effects similar to those of the above-described embodiment can also be obtained.

  Moreover, in the said embodiment and modification, although the deep groove ball bearing was used as the crank bearings 12a, 12b, 12c, you may use a cylindrical roller bearing as these crank bearings 12a, 12b, 12c instead. Although this cylindrical roller bearing also has some shakiness as with the deep groove ball bearing, it does not require troublesome preload adjustment work and is relatively inexpensive, so it is the same as when using the above deep groove ball bearing. An effect can be obtained.

It is sectional drawing along the axial direction of the eccentric rocking | fluctuation type gear apparatus by one Embodiment of this invention. It is sectional drawing along the II-II line in FIG. 1 of the eccentric rocking | fluctuation type gear apparatus by one Embodiment of this invention. It is sectional drawing along the axial direction of the eccentric rocking | fluctuation type gear apparatus by the modification of one Embodiment of this invention. It is sectional drawing along the IV-IV line in FIG. 3 of the eccentric rocking | fluctuation type gear apparatus by the modification of one Embodiment of this invention. It is sectional drawing along the axial direction of the eccentric rocking | fluctuation type gear apparatus by an example of the past.

Explanation of symbols

2 Outer cylinder 3 Internal tooth pin (internal tooth)
4 Carrier 4a First sandwiching portion 4b Second sandwiching portion 4c Shaft portion 4f Bolt hole 4p Bolt 10 Crankshaft 10a First eccentric portion (eccentric portion)
10b Second eccentric part (eccentric part)
12a First crank bearing (crank bearing)
12b Second crank bearing (crank bearing)
12c Crank bearing 13 Input gear 14 First external gear (external gear)
16 Second external gear (external gear)
14d, 16d Shaft part insertion hole (through hole)

Claims (4)

An outer cylinder with inner teeth on the inner surface;
A plurality of crankshafts that are spaced apart from each other in the circumferential direction in the outer cylinder, have eccentric portions, and are rotatably provided around their respective axes;
An input gear provided on each crankshaft, for inputting rotation to the provided crankshaft;
External teeth attached to the eccentric part of each crankshaft, oscillating and rotating in conjunction with the eccentric rotation of the eccentric part while meshing with the inner teeth, and having a through hole at a position shifted outward from the oscillation center Gears,
A carrier that is provided so as to be coaxial with the outer cylinder, and that rotates relative to the outer cylinder by transmitting a swinging rotation of the external gear;
A crank bearing that rotatably supports each crankshaft with respect to the carrier;
The carrier has a shaft portion that is inserted into a through hole of the external gear so that the swinging rotation of the external gear is transmitted,
The crank bearing is an eccentric oscillating gear device comprising a deep groove ball bearing or a cylindrical roller bearing.   The shaft portion is inserted in a state where there is play in the through hole of the external gear, and a part of the outer surface of the shaft portion contacts the inner surface of the through hole when the external gear swings and rotates. The eccentric oscillating gear device according to claim 1, wherein the eccentric oscillating gear device is arranged so as to. The carrier has a pair of sandwiching portions arranged on both sides in the axial direction of the external gear,
The eccentric swing type according to claim 1 or 2, wherein the pair of sandwiching portions and the shaft portion are detachably coupled to each other with the pair of sandwiching portions sandwiching the shaft portion therebetween. Gear device. The pair of sandwiching portions and the shaft portion are fastened to each other by bolts,
The eccentric rocking | fluctuation type gear apparatus of Claim 3 with which the bolt hole for screwing together the said volt | bolt is provided in one of the said pair of clamping parts so that an axial direction may be penetrated.

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