JP2015021554A - Eccentric oscillation type gear device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress an axial length and eliminate rattling of a transmission gear against a crank shaft.SOLUTION: An eccentric oscillation type gear device 1 includes: a crank shaft 20 having an eccentric part 20a; an oscillation gear 24 interlocked with the eccentric part 20a; an outer cylindrical portion 2 having an internal tooth pin 3 engaged with a tooth part of the oscillation gear 24; a carrier 4 rotatably supporting the crank shaft 20; a main bearing 6 permitting relative rotation between the outer cylindrical portion 2 and the carrier 4; and a transmission gear 18 having an inner hole 18a. The crank shaft 20 is press-fitted into the inner hole 18a of the transmission gear 18 so that displacement of the transmission gear 18 relative to the crank shaft 20 is restricted.

Description

  The present invention relates to an eccentric oscillating gear device.

  2. Description of the Related Art Conventionally, an eccentric oscillating gear device as described in Patent Document 1 is known as a speed reducer capable of obtaining a large reduction ratio. As shown in FIG. 5, in the gear device disclosed in Patent Document 1, the rotational driving force of the motor 61 is transmitted to the crankshaft 64 via the input shaft 62 and the transmission gear 63 to rotate the crankshaft 64. Let The transmission gear 63 is splined to the end of the crankshaft 64. For this reason, the transmission gear 63 is regulated so as not to rotate with respect to the crankshaft 64. A pair of retaining rings 65 are attached to the crankshaft 64 so as to sandwich the transmission gear 63. By these retaining rings 65, the transmission gear 63 is restricted from moving in the axial direction with respect to the crankshaft 64.

JP 2010-286098 A

  In the gear device described in Patent Document 1, the transmission gear 63 is sandwiched between a pair of retaining rings 65 to restrict the displacement of the transmission gear 63 with respect to the crankshaft 64. For this reason, it is necessary to project the crankshaft 64 from the transmission gear 63. Therefore, the axial length of the gear device becomes long. In addition, since the transmission gear 63 is splined to the crankshaft 64, there is play in the axial direction and the rotational direction, causing wear and vibration.

  Accordingly, the present invention has been made in view of the above points, and an object of the present invention is to reduce the axial length of the eccentric oscillating gear device and eliminate play of the transmission gear relative to the crankshaft. There is.

  In order to achieve the above object, the present invention provides a crankshaft having an eccentric portion, a swinging gear having a tooth portion and interlocking with the eccentric portion, and an internal tooth meshing with the tooth portion of the swinging gear. An outer cylinder part, an inner cylinder part that rotatably supports the crankshaft, a main bearing that allows relative rotation between the outer cylinder part and the inner cylinder part, and a transmission gear having an inner hole, An eccentric oscillating gear device in which the crankshaft is press-fitted into the inner hole of the transmission gear so that the displacement of the transmission gear relative to the crankshaft is regulated.

  In the present invention, when the crankshaft rotates due to the rotation of the transmission gear, the swinging gear swings and rotates in conjunction with the rotation of the eccentric portion. At this time, the oscillating gear oscillates and rotates while the tooth portion of the oscillating gear meshes with the inner teeth of the outer cylinder portion, and accordingly, relative rotation occurs between the inner cylinder portion and the outer cylinder portion. At this time, the transmission gear does not rattle with respect to the crankshaft. In other words, the displacement of the transmission gear relative to the crankshaft is regulated by press-fitting the crankshaft into the inner hole of the transmission gear. For this reason, the transmission gear does not rattle with respect to the crankshaft. Therefore, the transmission gear can be prevented from being worn at a portion in contact with the crankshaft, and vibration of the transmission gear can be suppressed. Further, since it is not necessary to attach a retaining ring for restricting the movement of the transmission gear in the axial direction to the crankshaft, it is not necessary to project the crankshaft from the transmission gear. For this reason, the axial direction length of a gear apparatus can be shortened by that much.

  Here, the inner hole is formed with a locking portion for locking the transmission gear in the rotational direction with respect to the crankshaft, except for a portion in close contact with the outer surface of the crankshaft by press-fitting. It may be.

  In this mode, the transmission gear is fixed to the crankshaft by press-fitting the crankshaft into the inner hole of the transmission gear, while the transmission is performed at a place other than the portion that is in close contact with the outer surface of the crankshaft by press-fitting. A locking portion for locking the transmission gear with respect to the crankshaft in the rotational direction is formed in the inner hole of the gear. For this reason, even if torque that transmits driving force from the transmission gear to the crankshaft is generated, it is possible to reliably prevent the transmission gear from being displaced in the rotational direction with respect to the crankshaft. Therefore, it is possible to more reliably avoid a situation in which the transmission gear rotates in the rotation direction in response to the rotational torque even though the crankshaft is press-fitted into the inner hole of the transmission gear.

  The transmission gear may include a gear main body having external teeth and a protruding portion protruding in the axial direction from the gear main body. The crankshaft may be press-fitted in at least a portion of the inner hole located at the protruding portion. The locking portion may be formed in a portion of the inner hole located in the gear body.

  In this aspect, when the torque for rotating the transmission gear is received by the external teeth of the gear body, the locking portion located in the gear body of the inner hole is locked to the crankshaft. Therefore, the force for rotating the transmission gear by the rotational torque can be reliably received at the locking portion. And since the crankshaft is press-fitted in at least a portion located in the protruding portion of the inner hole, the area of the portion that comes into close contact with the outer surface of the crankshaft can be increased by press-fitting. Therefore, the rattling prevention effect by press-fitting can be exhibited more effectively.

  A crank bearing may be fitted on the crankshaft. In this case, a positioning member sandwiched between the transmission gear and the crank bearing may be provided.

  In this aspect, the position of the transmission gear with respect to the crankshaft is determined by bringing the transmission gear into contact with the positioning member. Therefore, the axial position of the transmission gear with respect to the crankshaft can be accurately positioned.

  A male spline part for spline coupling the transmission gear may be formed at the end of the crankshaft. A female spline portion having a shape corresponding to the male spline portion may be formed in the inner hole. The convex part of the said female spline part may be fitted in the slope formed in the recessed part of the said male spline part.

  In this aspect, the transmission gear is constrained with respect to the crankshaft when the convex portion of the female spline portion is fitted to the slope formed in the concave portion of the male spline portion. Therefore, the transmission gear can be positioned in the axial direction by using the slope formed in the concave portion of the male spline portion.

  As described above, according to the present invention, in the eccentric oscillating gear device, it is possible to suppress the axial length and eliminate the play of the transmission gear with respect to the crankshaft.

It is a figure which shows the structure of the eccentric rocking | fluctuation type gear apparatus which concerns on embodiment of this invention. It is a figure for demonstrating the fixing structure of the transmission gear in the said gear apparatus. It is a figure which shows the principal part of the eccentric rocking | fluctuation type gear apparatus which concerns on other embodiment of this invention. It is a figure which shows the principal part of the eccentric rocking | fluctuation type gear apparatus which concerns on other embodiment of this invention. It is a figure which shows the structure of the conventional eccentric rocking | fluctuation type gear apparatus.

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

  The gear device 1 according to the present embodiment is a gear device that is applied as a speed reducer to, for example, a swivel unit such as a swivel trunk or arm joint of a robot or a swivel unit of various machine tools. The gear device 1 is provided, for example, between a base and a revolving body that revolves relative to the base, and provides a driving force at a rotational speed that is decelerated at a predetermined ratio with respect to the input rotational speed. It is a gear transmission which transmits by.

  As shown in FIG. 1, the gear device 1 of the present embodiment includes an outer cylinder portion 2, an internal tooth pin 3, a carrier 4 as an inner cylinder portion, a main bearing 6, a crankshaft 20, and a crank bearing 22. And a swing gear 24 and a transmission gear 18 fixed to the crankshaft 20. Since a plurality of crankshafts 20 are provided as will be described later, a plurality of transmission gears 18 are also provided.

  The outer cylinder portion 2 is configured to be fixed to one counterpart member (for example, a base of a robot), and also functions as a case of the gear device 1. This outer cylinder part 2 is formed in the substantially cylindrical shape which has an internal peripheral surface. The outer cylinder part 2 is fastened to the base of the robot with bolts or the like.

  A large number of internal tooth pins 3 are arranged at equal intervals in the circumferential direction on the inner peripheral surface of the outer cylindrical portion 2. The internal tooth pin 3 functions as an internal tooth with which the external tooth of the rocking gear 24 made of an external gear meshes. The number of teeth of the oscillating gear 24 is slightly smaller than the number of internal tooth pins 3. In the present embodiment, a plurality of (for example, two) oscillating gears 24 are used.

  The carrier 4 is configured to be fixable to the other partner member (for example, a revolving body of a robot). That is, the carrier 4 is fastened to the revolving body of the robot with a bolt or the like not shown. The carrier 4 is accommodated in the outer cylinder part 2 in a state of being arranged coaxially with the outer cylinder part 2. The carrier 4 is supported so as to be relatively rotatable with respect to the outer tube portion 2 by a pair of main bearings 6 that are separated from each other in the axial direction. Therefore, the carrier 4 rotates relative to the outer cylinder portion 2 around the same axis. When the carrier 4 rotates relative to the outer cylinder portion 2, the revolving body of the robot revolves with respect to the base.

  In the present embodiment, an example is shown in which the carrier 4 is fastened to the revolving body and revolved, and the outer cylinder portion 2 is fixed to the base and fixed, but the reverse arrangement may be employed. That is, the outer cylinder part 2 may be fastened by the turning body, and the carrier 4 may be fastened by the base. In this case, the outer cylinder portion 2 rotates relative to the carrier 4 so that the turning body of the robot turns relative to the base.

  The carrier 4 includes a base portion 32 and an end plate portion 34. The base portion 32 includes a substrate portion 32a disposed in the outer tube portion 2 in the vicinity of the end portion of the outer tube portion 2, and a plurality of shaft portions 32b extending in the axial direction from the substrate portion 32a toward the end plate portion 34. Have The shaft portion 32 b is fastened to the end plate portion 34 by the bolt 5. Thereby, the base 32 and the end plate part 34 are integrated. An accommodation space 33 for accommodating the oscillating gear 24 is formed between the substrate portion 32 a and the end plate portion 34. In addition, a through hole 4 a that penetrates in the axial direction across the substrate portion 32 a and the end plate portion 34 is provided in the center portion in the radial direction of the carrier 4.

  A plurality of crankshafts 20 (for example, three in this embodiment) are provided, and each crankshaft 20 is arranged at equal intervals in the circumferential direction of the carrier 4. Each crankshaft 20 is rotatably supported by the carrier 4 via a pair of crank bearings 22 and is arranged in a posture parallel to the rotational axis of the carrier 4 in this state.

  The crankshaft 20 includes a shaft main body 20c and a plurality (two in this embodiment) of eccentric portions 20a formed integrally with the shaft main body 20c. The plurality of eccentric portions 20a are arranged so as to be aligned in the axial direction at a position between the pair of journal portions 20d to which the crank bearings 22 are respectively attached. Each eccentric portion 20a is formed in a columnar shape eccentric from the axis of the shaft main body 20c by a predetermined amount of eccentricity. And each eccentric part 20a is formed in the crankshaft 20 so that it may have a phase difference of a predetermined angle mutually. In addition, the eccentric part 20a may be provided 1 or 3 or more.

  The oscillating gear 24 is attached to each eccentric part 20a of the crankshaft 20 via a roller bearing 28a. The oscillating gear 24 is formed to be slightly smaller than the inner diameter of the outer cylinder portion 2, and meshes with the internal tooth pin 3 on the inner surface of the outer cylinder portion 2 in conjunction with the rotation of the eccentric portion 20a when the crankshaft 20 rotates. While swinging and rotating.

  The oscillating gear 24 has a central portion through hole 24b, a plurality of eccentric portion insertion holes 24c, and a plurality of shaft portion insertion holes 24d. The central portion through hole 24 b is formed in the central portion in the radial direction of the swing gear 24. The central through hole 24b can be omitted.

  The eccentric portion insertion holes 24c are provided at equal intervals in the circumferential direction around the central through hole 24b in the swing gear 24. The eccentric portions 20a of the respective crankshafts 20 are inserted into the respective eccentric portion insertion holes 24c with the roller bearings 28a interposed therebetween.

  The shaft portion insertion holes 24 d are provided at equal intervals in the circumferential direction around the central portion through hole 24 b in the swing gear 24. Each shaft portion insertion hole 24d is formed at a position between the eccentric portion insertion holes 24c adjacent in the circumferential direction. Each shaft portion 32b of the carrier 4 is inserted into each shaft portion insertion hole 24d with play.

  The end portion of the crankshaft 20 on the substrate portion 32a side is formed as a journal portion 20d to which one crank bearing 22 is attached. On the other hand, the end portion of the crankshaft 20 on the side of the end plate portion 34 is formed as an extending portion 20e extending from the other journal portion 20d to which the other crank bearing 22 is mounted. That is, the shaft body 20c of the crankshaft 20 has a pair of journal portions 20d and an extending portion 20e.

  In this embodiment, the extending portion 20e protrudes outward from the carrier 4 along the axial direction of the carrier 4. However, the extension portion 20e is not limited to the form protruding to the outside of the carrier 4, and when there is no interference of the transmission gear 18 with respect to the carrier 4, the extension portion 20e is It may be in a form that falls within the range.

  A transmission gear 18 is attached to the extending portion 20e. That is, an inner hole 18a is formed in the transmission gear 18, and the transmission gear 18 is fixed to the extension 20e in a state where the extension 20e is inserted into the inner hole 18a.

  The transmission gear 18 includes a gear main body 18c having external teeth 18b and a protrusion 18d protruding in the axial direction from the gear main body 18c. The gear body 18c is formed in a disc shape, and external teeth 18b are formed on the outer peripheral portion. The protruding portion 18d is formed in a cylindrical shape concentric with the gear main body 18c so as to protrude from one surface of the gear main body 18c. The inner hole 18a is formed so as to penetrate the transmission gear 18 from the gear body 18c to the protrusion 18d. The external teeth 18b of the transmission gear 18 mesh with an input gear (not shown), and the transmission gear 18 is rotated by the driving force received from the input gear. The transmission gear 18 transmits the driving force received from the input gear to the crankshaft 20.

  Here, the attachment structure of the transmission gear 18 to the crankshaft 20 will be specifically described.

  As shown also in FIG. 2, the extension part 20e which is one end part of the crankshaft 20 (or the shaft main body 20c) is spline-processed, and thereby, the extension part 20e is arranged in the circumferential direction. A male spline portion 38 having a plurality of recesses 38a is formed. That is, a plurality of concave portions 38a extending in the axial direction of the crankshaft 20 (or the shaft main body 20c) are formed on the outer peripheral surface of the extending portion 20e at intervals in the circumferential direction. Each recess 38a is formed over a predetermined length from the end surface of the extending portion 20e (or the end surface of the crankshaft 20 or the end surface of the shaft body 20c).

  The inner surface of the concave portion 38a in the axial direction (the portion opposite to the end surface of the extending portion 20e) has a sloped surface 38b so that it gradually becomes shallower toward the inner side in the axial direction. In other words, the inclined surface 38b is inclined toward the outer side in the radial direction of the shaft body 20c as it goes to the back of the male spline portion 38 (to the left in FIG. 2). As the inclined surface 38b, for example, a hobbed-up portion generated when the extending portion 20e is cut by a cutting machine having a hob for spline processing can be employed.

  Note that the method of forming the slope 38b is not particularly limited, and the slope 38b may be formed on the bottom of the recess 38a by other formation methods. Moreover, the structure by which the slope 38b was abbreviate | omitted may be sufficient. In this case, the depth of the concave portion 38a may be substantially constant in the axial direction, and the inner end portion of the concave portion 38a may be substantially vertical.

  In the extending part 20e, a part of the outer surface of the part formed as the convex part 38c between the adjacent concave parts 38a, 38a is cut off. For this reason, in the convex part 38c, the site | part of the edge part side of the extension part 20e is one step lower compared with the site | part inside an axial direction. And in the site | part of the edge part side where this outer surface became low, the inner peripheral surface of the inner hole 18a of the transmission gear 18 does not closely_contact | adhere, but between the inner peripheral surface of the inner hole 18a and the outer surface of the extension part 20e. A slight gap is formed. The gap is formed in a range including at least a portion corresponding to the gear body 18c in the inner hole 18a.

  In addition, although the site | part which became one step lower is formed in the convex part 38c, the level | step difference is not necessarily required. There may be no step, or, contrary to the present embodiment, the outer peripheral surface 20f of the crankshaft 20 is formed one step higher on the inner side in the axial direction than the end portion side portion of the extending portion 20e. Also good.

  Of the inner hole 18a of the transmission gear 18, the inner peripheral surface of the portion located in the gear body 18c is subjected to spline gear cutting, whereby the inner peripheral surface of the portion of the inner hole 18a is A female spline portion 40 having a plurality of convex portions 40a arranged in the circumferential direction is formed. That is, a plurality of convex portions 40a extending in the axial direction (or thickness direction) of the transmission gear 18 are formed on the inner peripheral surface of the inner hole 18a at intervals in the circumferential direction. Each convex part 40a is formed in a shape suitable for the concave part 38a of the male spline part 38. The convex portion 40a of the female spline portion 40 is inserted into the concave portion 38a of the male spline portion 38. In this state, the transmission gear 18 cannot rotate about the axis of the crankshaft 20, Displacement in the direction is restricted. That is, the convex portion 40 a of the female spline portion 40 functions as a locking portion that locks the transmission gear 18 with respect to the crankshaft 20 in the rotation direction of the crankshaft 20.

  Of the inner hole 18a of the transmission gear 18, the inner peripheral surface 18e of the portion located in the protruding portion 18d is in close contact with the outer peripheral surface 20f of the axially inner portion of the extending portion 20e. That is, the extending part 20e is press-fitted into the inner hole 18a of the transmission gear 18 so as to be restrained by the protruding part 18d. Thereby, the displacement of the transmission gear 18 in the axial direction and the rotational direction with respect to the crankshaft 20 is restricted. In the inner hole 18a of the transmission gear 18, the rotation of the transmission gear 18 in the rotation direction of the crankshaft 20 is regulated separately from the portion where the crankshaft 20 is press-fitted and the outer peripheral surface 20f of the crankshaft 20 is in close contact. A stop (projection 40a) is provided.

  In addition, in the site | part by the side of the edge part in the extension part 20e, since a clearance gap is slightly formed between the inner peripheral surface 18e of the inner hole 18a, when press-fitting the extension part 20e into the inner hole 18a, It can be pushed into the inner hole 18a with a relatively weak force.

  The transmission gear 18 is attached to the crankshaft 20 so that the end surface of the extending portion 20e is substantially flush with one surface of the transmission gear 18. That is, at the time of press-fitting, by applying a flat jig (not shown) to the one surface of the transmission gear 18, the tip of the crankshaft 20 (extension part 20e) does not protrude from the inner hole 18a. can do. In this way, the transmission gear 18 can be positioned in the axial direction.

  In the present embodiment, the edge on the tip side of the crankshaft 20 (that is, the edge of the convex portion 38c of the male spline portion 38) is chamfered. However, the present invention is not limited to this, and the chamfering is performed. It does not have to be applied.

  Next, the operation of the gear device 1 according to the present embodiment will be described.

  When each transmission gear 18 is driven by an input gear (not shown), each crankshaft 20 rotates about its own axis. That is, a driving force for rotating the crankshaft 20 is input to the transmission gear 18. As the crankshaft 20 rotates, the eccentric portion 20a of the crankshaft 20 rotates eccentrically. As a result, the swing gear 24 swings and rotates while meshing with the internal tooth pin 3 on the inner surface of the outer cylinder portion 2 in conjunction with the eccentric rotation of the eccentric portion 20a. In the present embodiment, since the outer cylinder portion 2 is fixed to the base and does not move, the carrier 4 also rotates around the axis by the swinging rotation of the swinging gear 24. As a result, the carrier 4 and the swivel body rotate relative to the outer cylinder portion 2 and the base at a rotational speed decelerated from the input rotation.

  As described above, in the present embodiment, when the crankshaft 20 is rotated by the rotation of the transmission gear 18, the swinging gear 24 swings and rotates in conjunction with the rotation of the eccentric portion 20a. At this time, the oscillating gear 24 rotates while the outer teeth of the oscillating gear 24 mesh with the inner teeth pins 3 of the outer cylinder portion 2, so that the carrier 4 and the outer cylinder portion 2 are linked together. A relative rotation occurs. At this time, the transmission gear 18 does not rattle with respect to the crankshaft 20. That is, when the crankshaft 20 is press-fitted into the inner hole 18 a of the transmission gear 18, the displacement of the transmission gear 18 with respect to the crankshaft 20 is restricted. For this reason, the transmission gear 18 does not rattle against the crankshaft 20. Therefore, the transmission gear 18 can be prevented from being worn at a portion in contact with the crankshaft 20, and vibration of the transmission gear 18 can be suppressed. Further, since it is not necessary to attach a retaining ring for restricting the movement of the transmission gear 18 in the axial direction to the crankshaft 20, it is not necessary to project the crankshaft 20 from the transmission gear 18. For this reason, the axial direction length of the gear apparatus 1 can be shortened by that much.

  Further, in the present embodiment, the transmission gear 18 is fixed to the crankshaft 20 by press-fitting the crankshaft 20 into the inner hole 18a of the transmission gear 18, while being closely attached to the outer peripheral surface 20f of the crankshaft 20 by press-fitting. In a portion other than the portion where the transmission gear 18 is formed, a convex portion 40a is formed in the inner hole 18a of the transmission gear 18 so that the transmission gear 18 is locked to the crankshaft 20 in the rotation direction. For this reason, even if a torque for transmitting the driving force from the transmission gear 18 to the crankshaft 20 is generated, the transmission gear 18 can be prevented from being displaced in the rotational direction with respect to the crankshaft 20. Therefore, even when the crankshaft 20 is press-fitted into the inner hole 18a of the transmission gear 18, the situation where the transmission gear 18 rotates in the rotation direction due to the rotational torque is more reliably avoided. Can do.

  Moreover, in this embodiment, the transmission gear 18 has the gear main body 18c and the protrusion part 18d, and the convex part 40a is formed in the site | part located in the gear main body 18c among the inner holes 18a. For this reason, when the torque for rotating the transmission gear 18 is received by the external teeth 18b of the gear main body 18c, the convex portion 40a located in the gear main body 18c of the inner hole 18a is locked to the crankshaft 20. Therefore, the force that rotates the transmission gear 18 by the rotational torque can be reliably received at the convex portion 40a. Since the crankshaft 20 is press-fitted in at least a portion of the inner hole 18a located at the protruding portion 18d, the area of the portion that is in close contact with the outer peripheral surface 20f of the crankshaft 20 can be increased by press-fitting. Therefore, the rattling prevention effect by press-fitting can be exhibited more effectively.

  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 transmission gear 18 is positioned at a predetermined position of the crankshaft 20 using a jig (not shown) when the transmission gear 18 is assembled to the crankshaft 20. Instead of this configuration, as shown in FIG. 3, a positioning member 42 for positioning the transmission gear 18 at a predetermined position of the crankshaft 20 may be provided.

  Specifically, the positioning member 42 is sandwiched between one crank bearing 22 and the transmission gear 18 after being externally fitted to the extending portion 20 e of the crankshaft 20. Since the crank bearing 22 is in contact with a washer 44 provided at a position adjacent to the eccentric portion 20a, the position of the crank bearing 22 is fixed at a predetermined position. Since the positioning member 42 that contacts the crank bearing 22 is also determined at a predetermined position, the transmission gear 18 is determined at a predetermined position by contacting the positioning member 42. Therefore, the axial position of the transmission gear 18 with respect to the crankshaft 20 can be accurately positioned.

  Further, the transmission gear 18 is positioned at a predetermined position with respect to the crankshaft 20 by using the female spline portion 40 formed in the inner hole 18 a of the transmission gear 18 and the male spline portion 38 of the crankshaft 20. May be. As described above, the bottom surface of the recessed portion 38a of the extending portion 20e (the portion opposite to the end surface of the extending portion 20e) has a sloped surface 38b so that the inner surface gradually becomes shallower inward in the axial direction. ing. For this reason, as shown in FIG. 4, the end portion of the convex portion 40 a of the female spline portion 40 abuts on the inclined surface 38 b of the bottom surface of the concave portion 38 a of the male spline portion 38. On the other hand, it is fixed at a predetermined position. That is, when the inclined surface 38b is strongly pressed against the convex portion 40a of the female spline portion 40, a so-called rust effect is generated in which a large frictional force is generated on the contact surface, so that the transmission gear 18 is applied to the crankshaft 20. It is restrained in the state where it bites.

  In this embodiment, the transmission gear 18 is restrained with respect to the crankshaft 20 when the convex portion 40 a of the female spline portion 40 is fitted to the inclined surface 38 b formed in the concave portion 38 a of the male spline portion 38. Therefore, the transmission gear 18 can be positioned in the axial direction by using the slope 38b formed in the recess 38a of the male spline portion 38.

  In the embodiment, the configuration in which the convex portion 40a of the female spline portion 40 is provided as a locking portion where the transmission gear 18 is locked in the rotation direction with respect to the crankshaft 20 has been described. Instead of this configuration, a key groove may be formed in the inner hole 18a of the transmission gear 18, and the convex portion 38c of the male spline portion 38 may be locked in this key groove. In this case, the side surface of the key groove functions as a locking portion.

  In the embodiment, the crankshaft 20 has the extending portion 20e that protrudes toward the end plate portion 34, and the transmission gear 18 is arranged on the end plate portion 34 side. Instead of this configuration, the extension 20e of the crankshaft 20 may be disposed on the substrate portion 32a side, and the transmission gear 18 may be disposed on the substrate portion 32a side.

  In the above embodiment, the two oscillating gears 24 and 24 are provided, but the present invention is not limited to this. For example, a configuration in which one oscillating gear 24 is provided, or a configuration in which three or more oscillating gears 24 are provided may be employed.

  In the above embodiment, the plurality of crankshafts 20 are arranged around the central through hole 4a. However, the present invention is not limited to this. For example, a center crank type in which one crankshaft 20 is disposed at the center of the carrier 4 may be used.

DESCRIPTION OF SYMBOLS 1 Eccentric oscillation type gear apparatus 2 Outer cylinder part 3 Internal tooth pin 4 Carrier 6 Main bearing 18 Transmission gear 18a Inner hole 18b External tooth 18c Gear main body 18d Protrusion part 18e Inner peripheral surface 20 Crankshaft 20a Eccentric part 20c Shaft main body 20d Journal Part 20e Extension part 20f Outer peripheral surface 22 Crank bearing 24 Oscillating gear 32 Base part 32a Substrate part 32b Shaft part 34 End plate part 38 Male spline part 38a Concave part 38b Slope 38c Convex part 40 Female spline part 40a Convex part 42 Positioning member

Claims (5)

A crankshaft having an eccentric portion;
A rocking gear having a tooth portion and interlocking with the eccentric portion;
An outer cylinder portion having an inner tooth meshing with the tooth portion of the swing gear;
An inner cylinder portion for rotatably supporting the crankshaft;
A main bearing that allows relative rotation between the outer tube portion and the inner tube portion;
A transmission gear having an inner hole,
An eccentric oscillating gear device in which the crankshaft is press-fitted into the inner hole of the transmission gear so that displacement of the transmission gear relative to the crankshaft is regulated.   The inner hole is formed with a locking portion for locking the transmission gear in the rotation direction with respect to the crankshaft at a portion other than a portion in close contact with the outer surface of the crankshaft by press fitting. The eccentric oscillating gear device according to Item 1. The transmission gear has a gear main body having external teeth, and a protrusion protruding in the axial direction from the gear main body,
The crankshaft is press-fitted in at least a portion of the inner hole located at the protruding portion,
The eccentric oscillating gear device according to claim 2, wherein the locking portion is formed in a portion of the inner hole located in the gear main body. A crank bearing is fitted on the crankshaft,
The eccentric rocking | fluctuation type gear apparatus of any one of Claims 1-3 provided with the positioning member pinched | interposed between the said transmission gearwheel and the said crank bearing. At the end of the crankshaft, a male spline part for spline coupling the transmission gear is formed,
A female spline portion having a shape corresponding to the male spline portion is formed in the inner hole,
The eccentric oscillating gear device according to any one of claims 1 to 3, wherein a convex portion of the female spline portion is fitted to a slope formed in a concave portion of the male spline portion.

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