JP4918052B2 - Eccentric oscillating gear unit - Google Patents

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. 4 shows the 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 crankshaft 104 having two eccentric portions 104a and 104b arranged in the axial direction in the outer cylinder 102 is provided so as to be rotatable around the axis. External gears 108a and 108b are attached to the eccentric portions 104a and 104b via needle bearings 106a and 106b, respectively. A carrier 112 is provided in the outer cylinder 102 so as to be relatively rotatable with respect to the outer cylinder 102 by a pair of bearings 110a and 110b. The external gears 108a and 108b are connected to the pair of bearings 110a. , 110b is restricted from moving outward in the axial direction.

  When the input rotation is transmitted to the crankshaft 104, the external gears 108a and 108b are oscillated and rotated while meshing with the internal teeth 102a on the inner surface of the outer cylinder 102 in conjunction with the eccentric portions 104a and 104b. The swinging rotation of each of the external gears 108 a and 108 b is transmitted to the carrier 112 and rotated relative to the outer cylinder 102, and an output rotation is obtained from the carrier 112. A transmission gear 118 (intermediate gear) is provided between the two eccentric portions 104a and 104b of the crankshaft 104 and meshes with a cylindrical gear 116 provided at the radial center in the outer cylinder 102. The rotation of the shaft 104 is also transmitted to the cylindrical gear 116 via the transmission gear 118. The cylindrical gear 116 transmits the input rotation to another crankshaft (not shown) disposed around the cylindrical gear 116. As with the crankshaft 104, the other crankshaft includes two eccentric portions for swinging and rotating the external gears 108a and 108b, and a transmission gear meshing with the cylindrical gear 116 between the eccentric portions. Have That is, the transmission gear 118 provided on the crankshaft 104 transmits the input rotation to the transmission gear of another crankshaft via the cylindrical gear 116.

In this conventional eccentric oscillating gear device, when the crankshaft 104 is installed, there may be some deviation in the axial position. As described above, when the axial displacement of the crankshaft 104 occurs, the transmission gear 118 is also displaced in the axial direction, but the external gears 108a and 108b are moved outward in the axial direction by the pair of bearings 110a and 110b. Therefore, the axial end surface of the transmission gear 118 is pressed against the axial end surface of the external gear 108a or 108b, and the resistance increases and the rotational torque of the crankshaft 104 may increase. There is. Such an increase in rotational torque, like the crankshaft 104, may occur even when an axial misalignment occurs on another crankshaft (not shown). Therefore, in this conventional eccentric oscillating gear device, by providing the separating member 120 that axially separates the two external gears 108a and 108b, a large gap of a predetermined amount is provided between the external gears 108a and 108b. Is forming. This gap prevents the end face of the transmission gear 118 from being pressed against the end face of the external gear 108a or 108b even if the transmission gear 118 is displaced in the axial direction together with the crankshaft 104. Is allowed to move in the axial direction.
JP-A-9-57678

  However, the conventional eccentric oscillating gear device has problems that the number of parts increases and the device becomes large.

  That is, in the above-described conventional eccentric oscillating gear device, the separation member 120 is provided in order to provide a gap between the two external gears 108a and 108b. Therefore, the number of parts is increased by the separation member 120. To do. Further, the separation member 120 has a large gap of a predetermined amount so that the end face of the transmission gear 118 is not pressed against the end face of the external gear 108a or 108b even if the transmission gear 118 is displaced in the axial direction together with the crankshaft 104. Since it is formed between the two external gears 108a and 108b, the eccentric oscillating gear device is enlarged in the axial direction.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an eccentric oscillating gear device capable of suppressing an increase in the number of components and an increase in the size of the device. Is to provide.

  In order to achieve the above object, an eccentric oscillating gear device according to the present invention has a first eccentric portion and a second eccentric portion arranged so as to be aligned in the axial direction, and is provided rotatably around an axis. A crankshaft, a transmission gear that is externally fitted to the crankshaft so as to be movable in the axial direction, and that rotates integrally with the crankshaft about the same axis as the rotation shaft of the crankshaft; An outer cylinder, a first external gear attached to the first eccentric portion of the crankshaft and oscillating in conjunction with the eccentric rotation of the first eccentric portion while meshing with the inner teeth, and the crankshaft A second external gear which is attached to the second eccentric portion and meshes with the internal teeth and swings and rotates in conjunction with the eccentric rotation of the second eccentric portion; the transmission gear; the first external gear; The second external gear is sandwiched from both sides in the axial direction, and the gears are moved in the axial direction. A pair of restricting members for restricting the rotation of the first external gear and the second external gear are transmitted relative to the outer cylinder by being transmitted coaxially with the first external gear and the second external gear. And have a career to do.

  In the eccentric oscillating gear device, the transmission gear, the first external gear, and the second external gear are restricted from moving in the axial direction between the pair of regulating members, and the transmission gear is axially moved with respect to the crankshaft. Therefore, even if the crankshaft is misaligned in the axial direction, only the crankshaft is misaligned in the axial direction, and the transmission gear and both external gears are maintained at predetermined positions. Is done. In this case, the axial end surface of the transmission gear contacts the axial end surface of the first external gear or the second external gear, but can be prevented from being pressed. For this reason, it can prevent that the rotational torque of a crankshaft increases.

  In this eccentric oscillating gear device, since the transmission gear is externally fitted to the crankshaft so as to be movable in the axial direction as described above, the first external gear and the second external gear are conventionally used. It is not necessary to provide a separation member for forming a large gap of a predetermined amount with the gear. For this reason, an increase in the number of parts can be suppressed as long as the separation member is not provided, and the shaft is not required to provide a large gap between the first external gear and the second external gear. An increase in the size of the eccentric oscillating gear device in the direction can be suppressed.

  In the eccentric oscillating gear device, the transmission gear may be splined to the crankshaft.

  With this configuration, the transmission gear can move in the axial direction with respect to the crankshaft, and a specific structure capable of transmitting the rotation of the input gear from the transmission gear to the crankshaft can be configured. it can.

  In the eccentric oscillating gear device, the transmission gear may be externally fitted to a portion of the crankshaft located between the first eccentric portion and the second eccentric portion.

  With this configuration, the rotational force is transmitted from the input gear to the crankshaft via the transmission gear, as compared with the case where the transmission gear is fitted on the end portion of the crankshaft closer to the ends than both eccentric portions. At this time, the force received from the transmission gear can be received at a portion closer to the central portion in the axial direction of the crankshaft.

  In the eccentric oscillating gear device, the transmission gear may be externally fitted to a portion of the crankshaft that is positioned closer to the end in the axial direction than the first eccentric portion and the second eccentric portion. .

  With this configuration, it is easier to insert and remove the transmission gear in the axial direction from the end of the crankshaft than when the transmission gear is externally fitted between the eccentric portions of the crankshaft. Can be easily replaced.

  In the eccentric oscillating gear device, each of the restricting members may include an outer ring member of a carrier bearing that supports the carrier so as to be rotatable relative to the outer cylinder.

  In the eccentric oscillating gear device, each of the restricting members may be an inner ring member of a carrier bearing that supports the carrier so as to be rotatable relative to the outer cylinder.

  In the eccentric oscillating gear device, the carrier includes two carrier members arranged so as to sandwich the transmission gear, the first external gear, and the second external gear from both sides in the axial direction. Each of the regulating members may consist of a part of each of the carrier members.

  As described above, according to the eccentric oscillating gear device of the present invention, it is possible to suppress an increase in the number of parts and an increase in size of the device.

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

  FIG. 1 is a cross-sectional view along the axial direction of an eccentric oscillating gear device according to an embodiment of the present invention, and FIG. 2 is taken along the line II-II of the eccentric oscillating gear device shown in FIG. FIG. First, with reference to FIG.1 and FIG.2, the structure of the eccentric rocking | fluctuation type gear apparatus by one Embodiment of this invention 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 configured to obtain a reduced output rotation. 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, a carrier 4, a carrier bearing 6, an input shaft 8, a crank shaft 10, and a first crank bearing 12a. The second crank bearing 12b, the first external gear 14, the second external gear 16, the first roller bearing 18a, the second roller bearing 18b, and the transmission gear 20 are provided.

  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, 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 coaxially arranged with the outer cylinder 2 so as to rotate relative to the outer cylinder 2 around the same axis. It has become. The carrier 4 is fixed to the other arm portion (not shown) at the arm joint of the robot, and the carrier 4 and the outer cylinder 2 rotate relative to each other to form the one of the arm joints of the robot. The arm portion and the other arm portion pivot on each other on the same axis.

  Specifically, the carrier 4 is supported by the carrier bearing 6 so as to be rotatable relative to the outer cylinder 2. A pair of carrier bearings 6 are provided apart in the axial direction. Each carrier bearing 6 has an outer ring member 6 a fixed to the inner surface of the outer cylinder 2 and an inner ring member 6 b provided integrally on the outer periphery of the carrier 4.

  The carrier 4 includes a base portion 4a, an end plate portion 4b, and three shaft portions 4c.

  The base 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 of the base portion 4a in the radial direction, and three crankshaft mounting holes 4e (hereinafter simply referred to as mounting holes 4e) are provided around the through hole 4d of the base portion 4a. It is provided at equal intervals in the direction. An inner ring member 6b of the one carrier bearing 6 is integrally provided on the outer peripheral portion of the base portion 4a.

  The end plate portion 4b is provided to be separated from the base 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. In the outer cylinder 2, a closed space surrounded by both end surfaces of the end plate portion 4 b and the base portion 4 a facing each other and the inner surface of the outer cylinder 2 is formed. Further, a through hole 4f having the same diameter as the through hole 4d of the base portion 4a is provided at the radial center of the end plate portion 4b, and three crankshafts are provided around the through hole 4f of the end plate portion 4b. Mounting holes 4g (hereinafter simply referred to as mounting holes 4g) are provided at positions corresponding to the three mounting holes 4e of the base portion 4a. An inner ring member 6b of the other carrier bearing 6 is integrally provided on the outer peripheral portion of the end plate portion 4b.

  The three shaft portions 4c are integrally provided on the base portion 4a, and are formed in a columnar shape extending linearly from the base portion 4a toward the end plate portion 4b. As shown in FIG. 2, the three shaft portions 4c are arranged at equal intervals in the circumferential direction, and each shaft portion 4c is fastened to the end plate portion 4b by bolts 4h. Thereby, the base part 4a, the shaft part 4c, and the end plate part 4b are integrated.

  The input shaft 8 functions as an input portion to which rotation is input by a drive motor (not shown) provided on one arm portion (not shown), and the end of the input shaft 8 passes through a through hole 4f of the end plate portion 4b. The portion is inserted into the closed space in the outer cylinder 2. 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. An input gear 8 a is provided on the outer peripheral surface of the end portion of the input shaft 8 inserted into the closed space in the outer cylinder 2.

  Three crankshafts 10 are provided, and each crankshaft 10 is attached to the corresponding mounting hole 4e of the base portion 4a and the mounting hole 4g of the end plate portion 4b, thereby causing the crankshaft 10 to move within the outer cylinder 2. The input shaft 8 is arranged at equal intervals around the input shaft 8.

  Specifically, one end of each crankshaft 10 in the axial direction is attached to the corresponding attachment hole 4e of the base 4a via the first crank bearing 12a, while the other end is an end plate portion. 4b is mounted in the corresponding mounting hole 4g 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 axis with respect to the carrier 4.

  The first crank bearing 12a is a tapered roller bearing in which a truncated cone roller 12e is held between the inner surface of the outer ring member 12c and the outer surface of the inner ring member 12d. In the first crank bearing 12a, the outer surface of the outer ring member 12c is in contact with the inner surface of the mounting hole 4e of the base portion 4a. On the other hand, the inner surface of the inner ring member 12 d is in contact with the outer surface of one end of the crankshaft 10. Further, the end surface of the outer ring member 12c located on the outer side in the axial direction of the crankshaft 10 is in contact with the retaining ring 13a fitted in the groove portion 4k of the inner surface of the mounting hole 4e of the base portion 4a. The first crank bearing 12a is prevented from coming off by the retaining ring 13a. Further, a washer 13b is interposed between the end surface of the inner ring member 12d located on the inner side in the axial direction of the crankshaft 10 and the end surface of the first eccentric portion 10a.

  The second crank bearing 12b is a tapered roller bearing similar to the first crank bearing 12a. In the second crank bearing 12b, the outer surface of the outer ring member 12f is in contact with the inner surface of the mounting hole 4g of the end plate portion 4b. On the other hand, the outer surface of the inner ring member 12g is in contact with the outer surface of the other end portion of the crankshaft 10. An end surface of the outer ring member 12f located on the outer side in the axial direction of the crankshaft 10 is in contact with a retaining ring 13c fitted in a groove portion 4m on the inner surface of the mounting hole 4g of the end plate portion 4b. The second crank bearing 12b is prevented from coming off by the retaining ring 13c. Further, a washer 13d is interposed between the end surface of the inner ring member 12g located on the inner side in the axial direction of the crankshaft 10 and the end surface of the second eccentric portion 10b.

  The crankshaft 10 includes a first eccentric portion 10a and a second eccentric portion 10b that are arranged so as to be arranged at predetermined intervals in the axial direction between both ends supported by the crank bearings 12a and 12b. ing. 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 to which the transmission gear 20 is fitted is provided at a portion of the crankshaft 10 located between the first eccentric portion 10a and the second eccentric portion 10b. A spline groove extending in the axial direction is formed on the outer surface of the fitted portion 10c.

  The first external gear 14 is disposed in the closed space in the outer cylinder 2 and is attached to the first eccentric portion 10a of the crankshaft 10 via the first roller bearing 18a. When the 10 rotates, the first eccentric portion 10a rotates and swings while engaging with the inner tooth pin 3 on the inner surface of the outer cylinder 2 in conjunction with the eccentric rotation of the first eccentric portion 10a.

  Specifically, the first external gear 14 is formed to be slightly smaller than the inner diameter of the outer cylinder 2, and includes an external tooth 14a, a central through hole 14b, and three first eccentric portion insertion holes 14c. Three shaft portion insertion holes 14d are provided.

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

  The three first eccentric portion insertion holes 14c are provided 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 first external gear 14 can be moved relative to the first eccentric portion 10a of the crankshaft 10 in the axial direction.

  The three shaft portion insertion holes 14d are provided at equal intervals in the circumferential direction around the central portion through hole 14b in the first external gear 14, and each of the shaft portion insertion holes 14d has the three first first gears 14d. It is arrange | positioned in the position between the eccentric part insertion holes 14c, respectively. Each shaft portion insertion hole 14d is formed in a circular shape, and each shaft portion 4c of the carrier 4 is inserted into each shaft portion insertion hole 14d with play.

  The second external gear 16 is disposed in the closed space in the outer cylinder 2 and is attached to the second eccentric portion 10b of the crankshaft 10 via the second roller bearing 18b. When the 10 rotates, the second eccentric portion 10b rotates in a swinging manner while meshing with the inner tooth pin 3 on the inner surface of the outer cylinder 2 in conjunction with the eccentric rotation of the second eccentric portion 10b. The second external gear 16 has the same structure as the first external gear 14.

  Specifically, the second external gear 16 includes an external tooth 14a of the first external gear 14, a central through hole 14b, three first eccentric part insertion holes 14c, and three shaft part insertion holes 14d. Similar external teeth 16a, a central through hole 16b, three second eccentric portion insertion holes 16c, and three shaft portion insertion holes 16d are provided. However, the input shaft 8 is inserted through the central through hole 16b with play. Further, the second eccentric portion 10b of the crankshaft 10 is inserted in each second eccentric portion insertion hole 16c with the second roller bearing 18b interposed therebetween, and the second external gear 16 is It can move relative to the eccentric portion 10b in the axial direction.

  The transmission gear 20 transmits the rotation of the input gear 8 a to the crankshaft 10, and three transmission gears 20 are provided corresponding to each crankshaft 10. These three transmission gears 20 are disposed between the first external gear 14 and the second external gear 16 in the closed space in the outer cylinder 2. That is, the first external gear 14, the transmission gear 20, and the second external gear 16 are arranged in this order in the closed space in the axial direction. Each transmission gear 20 is configured to rotate while sliding in contact with the axial end surface of the first external gear 14 or the axial end surface of the second external gear 16 at each end surface in the axial direction. .

  Each transmission gear 20 has an external tooth 20a that meshes with the input gear 8a and a fitting portion 20b that fits into the fitted portion 10c of the crankshaft 10. In the present embodiment, each transmission gear 20 is externally fitted so as to be movable in the axial direction with respect to the fitted portion 10c of the corresponding crankshaft 10 in the fitting portion 20b. The crankshaft 10 rotates integrally around the same axis.

  Specifically, the fitting portion 20b is formed by forming a spline groove extending in the axial direction on the inner surface of a circular through hole provided in the radial center of the transmission gear 20, and this fitting portion 20b. Are splined to the fitted portion 10c of the crankshaft 10. Thus, the transmission gear 20 is externally fitted to the fitted portion 10c of the crankshaft 10 so as to be movable in the axial direction.

  In the present embodiment, the first external gear 14, the transmission gear 20, and the second external gear 16 are sandwiched between the outer ring members 6 a and 6 a of the pair of carrier bearings 6 and 6 from both sides in the axial direction. The axial movement of these gears 14, 20, 16 is restricted. That is, in this embodiment, the outer ring member 6a of the carrier bearing 6 functions as a regulating member.

  Specifically, of the outer ring member 6 a of one carrier bearing 6, the end surface located on the axially inner side of the crankshaft 10 abuts the corresponding axial end surface of the first external gear 14, and the other carrier bearing 6. Of the outer ring member 6 a, the end surface located on the inner side in the axial direction of the crankshaft 10 abuts on the corresponding axial end surface of the second external gear 16, and the axial movement of the gears 14, 20, 16 is restricted. As described above, the end surface of the outer ring member 6a of one carrier bearing 6 and the end surface of the first external gear 14 come into contact with each other, and the end surface of the outer ring member 6a of the other carrier bearing 6 and the second external gear 16 The end surfaces of the first external gear 14 rotate while sliding in contact with the end surface of the outer ring member 6a of one carrier bearing 6, and the second end surfaces of the first external gear 14 are in contact with each other. The external gear 16 is configured to rotate while its end surface is in sliding contact with the end surface of the outer ring member 6 a of the other carrier bearing 6.

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

  First, rotation is input to the input shaft 8 of the gear device by driving a drive motor (not shown). Thereby, the input gear 8 a rotates together with the input shaft 8, and the rotation of the input gear 8 a is transmitted to each crankshaft 10 via each transmission gear 20. For this reason, each crankshaft 10 rotates, and the first eccentric portion 10a and the second eccentric portion 10b of the crankshaft 10 rotate eccentrically, thereby interlocking with the first eccentric portion 10a and the first external gear 14. Oscillates and rotates while meshing with the inner tooth pin 3 on the inner surface of the outer cylinder 2, and the second external gear 16 oscillates while meshing with the inner tooth pin 3 on the inner surface of the outer cylinder 2 in conjunction with the second eccentric portion 10b. Dynamic rotation. The oscillating rotation of the first external gear 14 and the second external gear 16 is transmitted to the carrier 4 through the shaft portion 4c, and the entire carrier 4 is rotated with respect to the outer cylinder 2 at a speed reduced from the input rotation. Relative rotation.

  As described above, in the present embodiment, the transmission gear 20, the first external gear 14, and the second external gear 16 are restricted from moving in the axial direction between the outer ring members 6a, 6a of the pair of carrier bearings 6, 6. Since the transmission gear 20 is externally fitted to the crankshaft 10 so as to be movable in the axial direction, even if the crankshaft 10 is displaced in the axial direction, only the crankshaft 10 is The transmission gear 20 is maintained at a predetermined position between the external gears 14 and 16 by being displaced in the direction. In this case, the axial end surface of the transmission gear 20 is in contact with the axial end surface of the first external gear 14 or the second external gear 16 but can be prevented from being pressed. For this reason, it is possible to prevent the rotational torque of the crankshaft 10 from increasing. The displacement of the crankshaft 10 in the axial direction includes an error in the installation position of the crankshaft 10, washers 13b and 13d for holding the crankshaft 10 with respect to the carrier 4, the first crank bearing 12a, and the second crank bearing 12b. And due to dimensional errors of the retaining rings 13a and 13b, processing errors of the grooves 4k and 4m into which the retaining rings 13a and 13c are fitted, and the like.

  Further, in the present embodiment, as described above, the transmission gear 20 is externally fitted to the crankshaft 10 so as to be movable in the axial direction, so that the end surface of the transmission gear 20 is the first external gear 14 or the second outer gear. Since it can be prevented from being pressed against the end face of the toothed gear 16, the separation member for forming a predetermined large gap between the first external gear 14 and the second external gear 16 as in the prior art. May not be provided. For this reason, an increase in the number of parts can be suppressed by the amount that the separation member is not provided, and a large gear device in the axial direction can be provided by not requiring a large gap between the external gears 14 and 16. Can be suppressed.

  In the present embodiment, the transmission gear 20 is splined to the crankshaft 10. Thereby, the transmission gear 20 is movable in the axial direction with respect to the crankshaft 10, and a specific structure capable of transmitting the rotation of the input gear 8a from the transmission gear 20 to the crankshaft 10 is configured. Can do.

  Further, in the present embodiment, the transmission gear 20 is externally fitted to the fitted portion 10c located between the first eccentric portion 10a and the second eccentric portion 10b of the crankshaft 10, so that the crankshaft 10 Compared to the case where the transmission gear 20 is fitted on the end portions of the eccentric portions 10a and 10b, the transmission is transmitted when the rotational force is transmitted from the input gear 8a to the crankshaft 10 via the transmission gear 20. The force received from the gear 20 can be received at a portion closer to the central portion of the crankshaft 10 in the axial direction, and the crankshaft 10 can receive the force from the transmission gear 20 in a more balanced manner.

  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, as in a modification of the above-described embodiment shown in FIG. 3, the transmission gear 20 is a portion of the crankshaft 10 that is positioned closer to one end in the axial direction than the first eccentric portion 10 a and the second eccentric portion 10 b. You may externally fit in the fitting part 10c. The axial movement of the transmission gear 20, the first external gear 14, and the second external gear 16 may be restricted using the inner ring members 6b, 6b of the pair of carrier bearings 6, 6 as restricting members.

  Specifically, in this modification, the transmission gear 20, the first external gear 14, and the second external gear 16 are arranged in this order in the closed space in the outer cylinder 2 in this order. The crankshaft 10 is provided with a first eccentric portion 10a and a second eccentric portion 10b adjacent to each other, and a fitted portion so as to be positioned closer to one end portion in the axial direction than both the eccentric portions 10a and 10b. 10c is provided. The fitting portion 20b of the transmission gear 20 is externally fitted to the fitted portion 10c by spline coupling, and the first external gear 14 is attached to the first eccentric portion 10a via the first roller bearing 18a. The second external gear 16 is attached to the second eccentric portion 10b via the second roller bearing 18b.

  Of the inner ring member 6 b of one carrier bearing 6, the end surface located on the inner side in the axial direction of the crankshaft 10 is in contact with the corresponding axial end surface of the transmission gear 20 and the inner ring member 6 b of the other carrier bearing 6. Of these, the end surface located on the inner side in the axial direction of the crankshaft 10 is in contact with the corresponding axial end surface of the second external gear 16. That is, the transmission gear 20, the first external gear 14, and the second external gear 16 are sandwiched between the end faces of the inner ring members 6 b and 6 b of the carrier bearings 6 and 6 to restrict axial movement. Yes.

  According to the configuration of this modification, the transmission gear 20 is externally fitted to the fitted portion 10c located closer to the axial end than the first eccentric portion 10a and the second eccentric portion 10b of the crankshaft 10. Therefore, compared with the case where the transmission gear 20 is externally fitted between the eccentric portions 10a and 10b of the crankshaft 10, the transmission gear 20 can be easily inserted and removed from the end of the crankshaft 10 in the axial direction. 20 can be easily replaced.

  A fitted portion 10c is provided adjacent to the second external gear 16 on the opposite side of the first external gear 14 with respect to the second external gear 16 in the crankshaft 10, and the transmission gear 20 is externally connected to the fitted portion 10c. The first external gear 14, the second external gear 16, and the transmission gear 20 may be arranged in this order from one end side in the axial direction of the crankshaft 10.

  In addition, the regulating member that regulates the axial movement of the transmission gear 20, the first external gear 14, and the second external gear 16 may be formed of a part of the base portion 4 a and the end plate portion 4 b of the carrier 4. The base part 4a and the end plate part 4b in this case are included in the concept of the carrier member of the present invention.

  Further, a regulating member for regulating the axial movement of the transmission gear 20, the first external gear 14 and the second external gear 16 is provided separately from the base 4a and the end plate 4b of the carrier bearing 6 and the carrier 4. It may be provided.

  Further, the inner ring member 6b of the carrier bearing 6 may be formed separately from the base portion 4a and the end plate portion 4b.

  Further, the external fitting of the transmission gear 20 to the crankshaft 10 is not limited to spline coupling, and any type of external fitting that allows the transmission gear 20 to move in the axial direction with respect to the crankshaft 10 is possible. Also good. For example, a key groove extending in the axial direction is formed in one of the fitted portion of the crankshaft 10 and the fitting portion of the transmission gear 20, and a key extending in the axial direction is formed in the other. The fitting portion of the transmission gear 20 may be externally fitted to the fitted portion of the crankshaft 10 so that the keyway and the key are fitted.

  Further, as in the above-described conventional gear device (see FIG. 4), the input rotation is transmitted from the transmission gear 118 provided on the crankshaft 104 to another crankshaft (not shown) via the cylindrical gear 116. The present invention can be applied.

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 of the eccentric rocking | fluctuation type gear apparatus shown in FIG. It is a fragmentary sectional view 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 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 Base (carrier member)
4b End plate part (carrier member)
6 Carrier bearing 6a Outer ring member 6b Inner ring member 8a Input gear 10 Crankshaft 10a First eccentric part 10b Second eccentric part 14 First external gear 16 Second external gear 20 Transmission gear

Claims (7)

A crankshaft having a first eccentric part and a second eccentric part arranged so as to be aligned in the axial direction, and provided to be rotatable around the axis;
A transmission gear that is externally fitted to the crankshaft so as to be movable in the axial direction, and rotates integrally with the crankshaft about the same axis as the rotation shaft of the crankshaft;
An outer cylinder with inner teeth on the inner surface;
A first external gear attached to the first eccentric portion of the crankshaft and oscillating and rotating in conjunction with the eccentric rotation of the first eccentric portion while meshing with the inner teeth;
A second external gear attached to the second eccentric portion of the crankshaft and oscillating and rotating in conjunction with the eccentric rotation of the second eccentric portion while meshing with the inner teeth;
A pair of restricting members that sandwich the transmission gear, the first external gear and the second external gear from both sides in the axial direction and restrict axial movement of the gears;
Eccentric oscillation provided with a carrier that is provided coaxially with the outer cylinder and that rotates relative to the outer cylinder by transmitting the oscillation rotation of the first external gear and the second external gear. Dynamic gear device.   The eccentric oscillating gear device according to claim 1, wherein the transmission gear is spline-coupled to the crankshaft.   The eccentric oscillating gear device according to claim 1 or 2, wherein the transmission gear is externally fitted to a portion of the crankshaft located between the first eccentric portion and the second eccentric portion.   3. The eccentric rocking according to claim 1, wherein the transmission gear is externally fitted to a portion of the crankshaft that is positioned closer to an end in the axial direction than the first eccentric portion and the second eccentric portion. Dynamic gear device.   5. The eccentric oscillating gear device according to claim 1, wherein each of the regulating members includes an outer ring member of a carrier bearing that supports the carrier so as to be rotatable relative to the outer cylinder.   5. The eccentric oscillating gear device according to claim 1, wherein each of the regulating members includes an inner ring member of a carrier bearing that supports the carrier so as to be relatively rotatable with respect to the outer cylinder. The carrier has two carrier members arranged so as to sandwich the transmission gear, the first external gear and the second external gear from both sides in the axial direction,
5. The eccentric oscillating gear device according to claim 1, wherein each of the restricting members includes a part of each of the carrier members.

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