JP2013194846A - Eccentric oscillation type gear device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an eccentric oscillation type gear device reducing the number of management item numbers of a transmission gear and a crankshaft.SOLUTION: An eccentric oscillation type gear device 10 includes: a crankshaft 46 having journal parts 46d, 46e and eccentric parts 46a, 46b; a transmission gear 44 attached to the crankshaft 46 to transmit a driving force from a driving source to the crankshaft 46; oscillation gears 48a, 48b having through-holes in which the eccentric parts 46a, 46b are inserted, and teeth are provided; a case 12; and a carrier 14. In the crankshaft 46, a main part 55, to which the eccentric parts 46a, 46b and the journal parts 46d, 46e are disposed, and a sub part 56, which is disposed to an end of the main part 55 to be capable of being fitted and to which the transmission gear 44 can be attached, are separately formed, and the main part 55 and the sub part 56 are assembled with each other.

Description

  The present invention relates to an eccentric oscillating gear device.

  Conventionally, as disclosed in Patent Documents 1 to 3 below, an eccentric oscillating gear device that can be used for a joint portion of an industrial robot or the like is known. The eccentric oscillating gear device disclosed in Patent Documents 1 to 3 includes a case having internal teeth, a carrier inserted into the case and rotatable with respect to the case, an eccentric portion, and the carrier. A crankshaft that is rotatably supported, a transmission gear attached to an end of the crankshaft, and a swing gear that is fitted to an eccentric portion and swings while meshing with the internal teeth of the case. When the motor is driven and the crankshaft rotates about the axis via the transmission gear, the swing gear swings, and accordingly, the carrier rotates relative to the case. And since the case is fixed to the proximal arm of the industrial robot by bolts and the carrier is fixed to the distal arm by bolts, when the motor is driven, the rotation speed is reduced at a predetermined ratio. The distal arm can be rotated relative to the proximal arm.

JP 2001-221198 A JP 2001-254787 A JP 2005-47006 A

  As disclosed in Patent Documents 1 to 3, the crankshaft of the eccentric oscillating gear device has a pair of journal portions to which a pair of crank bearings are respectively attached. It is rotatably supported on the carrier by a crank bearing. Further, the tip end portion of the crankshaft continuing from one of the journal portions is splined, and a transmission gear is attached to the splined tip portion. In the eccentric oscillating gear devices disclosed in these Patent Documents 1 to 3, the outer diameters of the journal portion and the eccentric portion differ depending on the model, and the length of the tip end portion of the crankshaft subjected to the spline processing is the gear. It differs depending on the configuration of the mating member to which the device is attached. For this reason, even if the number of teeth of the transmission gear is the same, if the outer diameter of the journal portion is different, transmission gears having fitting holes corresponding to the journal portion must be prepared respectively. There is a problem that the number of transmission gear management products increases. In addition, even if the outer diameter of the journal part is the same, if the length of the tip part of the crankshaft subjected to spline processing is different, a crankshaft corresponding to the length must be prepared respectively. There is a problem that the number of crankshaft management products increases.

  Accordingly, the present invention has been made in view of the above prior art, and an object of the present invention is to provide an eccentric oscillating gear device capable of reducing the number of managed gears and transmission gears.

  In order to achieve the above object, the present invention provides a gear device for generating a relative rotation at a rotational speed reduced with respect to an input rotational speed between a first member and a second member. A crankshaft having a journal portion and an eccentric portion with which the crank bearing contacts, a transmission gear attached to the crankshaft for transmitting a driving force from a driving source to the crankshaft, and a through hole into which the eccentric portion is inserted. A swing gear having a hole and a tooth portion; a case configured to be attachable to one of the first member and the second member; and the first member and the second member. A carrier that can be attached to the other of the two, the carrier rotatably supports the crankshaft, and the case has internal teeth that mesh with teeth of the swing gear, Case and said case A is rotatable relative to each other concentrically by the swing of the swing gear accompanying the rotation of the crankshaft, and the crankshaft includes a main portion provided with the eccentric portion and the journal portion. The main part and the sub part are assembled with each other, and the sub part provided to be fitted to the end of the main part and configured to be attached to the transmission gear is formed separately. This is an eccentric oscillating gear device having the above structure.

  In the present invention, the crankshaft is divided into a main part provided with a journal part and an eccentric part, and a sub part configured to be able to attach a transmission gear, and the main part and the sub part are formed separately. Yes. And the sub part is assembled | attached to the main part. For this reason, the main part and the sub part can be managed separately and independently. In this case, for the main part, for example, the part number of the main part is set for each of the journal parts having different outer diameters and eccentric parts, and the sub part is made common to each main part, for example. Can do. And about a transmission gear, what is necessary is just to comprise so that attachment with respect to this common subpart is possible. Therefore, the size of the fitting hole of the transmission gear changes due to the different outer diameters of the journal portions, thereby avoiding a situation where the number of teeth is a different management product number even though the number of teeth is the same. Therefore, it is possible to suppress an increase in the number of managed product numbers of the transmission gear.

  For the main part provided with the eccentric part and the journal part, the common part is not affected by the specifications of the customer, and the length of the sub part fitted to the tip part of the main part is set to the customer's specification. The configuration can be changed according to the specification. For this reason, the main part of the crankshaft, which requires particularly troublesome machining, does not depend on the specifications of the customer, and therefore, prospective production can be performed before an order is confirmed. Then, when the order is confirmed, the sub part is manufactured and assembled to the main part to manufacture the crankshaft. Therefore, since it is sufficient to produce only the secondary part after the order is confirmed, the lead time required for production of the crankshaft after the order is confirmed can be shortened. Furthermore, it is possible to assemble an eccentric oscillating gear device using only the main part that does not depend on the customer's specifications as a temporary crankshaft. After confirmation, the sub part and the transmission gear according to the customer specifications can be attached before shipping. Thereby, the manufacturing lead time of the product itself can be shortened.

  In the eccentric oscillating gear device, it is preferable that the sub-portion is splined to attach the transmission gear.

  In this aspect, in the journal part provided in the main part of the crankshaft, the crank bearing is in contact, and the journal part is separated from the sub part. Therefore, the size of the spline and the outer diameter of the journal portion can be set independently. As a result, it is possible to avoid a situation in which the transmission gear cannot be shared even if the outer diameters of the journal portions are different even when the number of teeth is the same. That is, when the crankshaft is an integral part, the splined part is continuous with the journal part, so the size of the spline is determined by the outer diameter of the journal part. However, the transmission gear cannot be shared for crankshafts with the same outer diameter but different journal diameters. On the other hand, in the case of the configuration in which the journal portion and the spline-processed portion are separated as in the present embodiment, a situation in which the size of the spline is determined by the outer diameter of the journal portion does not occur. As a result, if the number of teeth is the same, the transmission gear can be shared even when the outer diameter of the journal portion of the crankshaft is different.

  It is preferable that the sub part is fitted in a recess formed on the front end surface of the main part. In this aspect, the sub part can be fixed to the main part by fitting the sub part into the recess formed in the front end surface of the main part. Therefore, the sub part (transmission gear) can be easily positioned with respect to the main part.

  Positioning means for determining an axial position of the sub part with respect to the main part may be provided. In this aspect, the sub part can be easily and reliably positioned with respect to the main part in the axial direction.

  As described above, according to the present invention, it is possible to reduce the number of managed product numbers of the transmission gear and the crankshaft.

It is sectional drawing which shows the structure of the eccentric rocking | fluctuation type gear apparatus which concerns on embodiment of this invention. It is a fragmentary sectional view which shows the structure of the crankshaft and transmission gear which are used for the eccentric rocking | fluctuation type gear apparatus which concerns on other embodiment of this invention. It is a fragmentary sectional view which shows the structure of the crankshaft and transmission gear which are used for the eccentric rocking | fluctuation type gear apparatus which concerns on other embodiment of this invention. It is a fragmentary sectional view which shows the structure of the crankshaft and transmission gear which are used for the eccentric rocking | fluctuation type gear apparatus which concerns on other embodiment of this invention. It is sectional drawing which shows partially the structure of the eccentric rocking | fluctuation type gear apparatus which concerns on other embodiment of this invention.

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

  As shown in FIG. 1, the eccentric oscillating gear device 10 according to the present embodiment is input with a case 12 and a carrier 14 that can rotate relative to the case 12 inside the case 12. And a speed reduction mechanism 18 for decelerating the rotational speed at a predetermined rotational speed ratio. In the gear device 10, a first arm (not shown), which is a first member (mating member), is fastened to the case 12, and a second member (mating member), which is not shown, is connected to the carrier 14. Two arms are fastened. That is, the first arm and the second arm constitute a robot arm, and the eccentric oscillating gear device 10 is constituted as a speed reducer used for a joint of the robot arm.

  The case 12 has a case main body 12a formed in a cylindrical shape, and a flange portion 12b provided outside the case main body 12a. The flange portion 12b is shorter in the axial direction than the case main body 12a, and has a shape projecting outward from the axial central portion of the case main body 12a. The flange portion 12b may have a shape protruding outward from the axial end portion of the case main body 12a.

  A large number of pin grooves (internal tooth grooves) 12d are formed at equal intervals in the circumferential direction on the inner peripheral surface of the case body 12a, and pin-shaped inner teeth 24 are fitted into the pin grooves 12d, respectively. .

  Bolt insertion holes 12c are provided in the flange portion 12b at equal intervals in the circumferential direction. The case 12 and the first arm are fastened to each other by screwing a bolt (not shown) inserted through the bolt insertion hole 12c into the screw hole of the first arm (not shown). A motor (not shown) that is a drive source is fixed to the first arm.

  The carrier 14 is supported on the case 12 by a pair of main bearings 26 arranged at intervals in the axial direction, and can rotate concentrically with the case 12. That is, the carrier 14 rotates relative to the case 12 around the axis of the case 12. The main bearings 26 are each constituted by an angular ball bearing.

  The carrier 14 includes a disc-shaped end plate portion 30 and a base portion 31 fastened to the end plate portion 30. The base portion 31 includes a substrate portion 32 and a shaft portion 33 projecting from one surface of the substrate portion 32.

  A plurality of shaft portions 33 are provided, and these shaft portions 33 are arranged at equal intervals in the circumferential direction. The shaft portion 33 and the end plate portion 30 are fastened to each other by a bolt 34 in a state where the tip surface of the shaft portion 33 is in contact with the end plate portion 30. In this state, a space having a predetermined width in the axial direction is formed between the base portion 31 and the end plate portion 30.

  A bolt fastening hole 33 a is provided in the shaft portion 33, and the bolt 34 inserted into the bolt insertion hole 30 a of the end plate portion 30 from the opposite side to the shaft portion 33 is screwed into the bolt fastening hole 33 a of the shaft portion 33. Has been. A pin 36 for positioning the end plate portion 30 with respect to the base portion 31 is disposed so as to straddle the shaft portion 33 and the end plate portion 30. That is, the pin 36 is inserted into the insertion hole 30 b formed in the end plate portion 30 and is inserted into the pin hole 33 b formed in the distal end surface of the shaft portion 33.

  A second arm that is a counterpart member is attached to the base 31. That is, a bolt insertion hole is formed in the second arm, and a fastening hole 31 a is formed on the outer surface of the base portion 31 at a position corresponding to the bolt insertion hole. And the 2nd arm and the base 31 are mutually fastened by screwing the unillustrated mounting bolt inserted in the bolt insertion hole of the 2nd arm to the fastening hole 31a of the base 31.

  The substrate portion 32 is formed with a central through hole 32a penetrating the central portion in the radial direction of the base portion in the thickness direction. The substrate portion 32 is provided with a hole portion 32b so that one end portion of a crankshaft 46 described later is inserted and the second crank bearing 52 is attached. A plurality of the holes 32b are provided around the central through hole 32a.

  The end plate portion 30 is formed with a through hole 30c penetrating the center in the axial direction. The through hole 30 c of the end plate portion 30 has substantially the same inner diameter as the central through hole 32 a of the substrate portion 32.

  The speed reduction mechanism 18 includes a transmission gear 44, a crankshaft 46, and a swing gear (a first swing gear 48a and a second swing gear 48b). The first oscillating gear 48 a and the second oscillating gear 48 b each have external teeth that are teeth that mesh with the internal teeth 24 of the case 12.

  The transmission gear 44 is attached to the end of the crankshaft 46 and is provided on an unillustrated input shaft for inputting a driving force for rotating the carrier 14 (a driving force using a motor (not shown) as a driving source). Is engaged with a drive gear (not shown). Accordingly, the driving force is transmitted to the crankshaft 46 via the transmission gear 44, whereby the crankshaft 46 is interlocked with the rotation of the input shaft. Note that the input shaft may be arranged such that the distal end portion is inserted into the through hole 30 c of the end plate portion 30.

  The crankshaft 46 is disposed in parallel with the input shaft, is rotatably supported by the end plate portion 30 via the first crank bearing 51, and is freely rotatable on the substrate portion 32 via the second crank bearing 52. It is supported by. In other words, the first crank bearing 51 is disposed between the end plate portion 30 and the crank shaft 46, and the second crank bearing 52 is disposed between the substrate portion 32 and the crank shaft 46. Both the first crank bearing 51 and the second crank bearing 52 are constituted by tapered roller bearings.

  The crankshaft 46 includes a shaft main body 46c and eccentric portions (first eccentric portion 46a and second eccentric portion 46b) disposed in an intermediate portion in the axial direction of the shaft main body 46c. The shaft body 46c has a pair of journal portions (a first journal portion 46d and a second journal portion 46e) with which the crank bearings 51 and 52 come into contact. The first journal part 46d and the second journal part 46e have the same cross-sectional shape (circular shape), are formed on the same axis, and are spaced apart from each other in the axial direction. A first crank bearing 51 is attached to the first journal portion 46d, and a second crank bearing 52 is attached to the second journal portion 46e. The crank bearings 51 and 52 are for holding the crankshaft 46 rotatably with respect to the carrier 14.

  The first and second eccentric portions 46a and 46b are disposed adjacent to each other in the axial direction between the first journal portion 46d and the second journal portion 46e. The first eccentric part 46a is adjacent to the first journal part 46d, and the second eccentric part 46b is adjacent to the second journal part 46e. The first journal portion 46d, the first eccentric portion 46a, the second eccentric portion 46b, and the second journal portion 46e are formed by machining one bar, and are integrally formed.

  The first and second eccentric portions 46a and 46b are eccentric with respect to the crankshaft center that is the shaft center of the shaft body 46c. The first and second eccentric parts 46a and 46b are out of phase with each other. That is, the eccentric direction of the first eccentric portion 46a with respect to the crank shaft center and the eccentric direction of the second eccentric portion 46b with respect to the crank shaft center are different from each other, and the phase angle is shifted by 180 degrees. Further, the plurality of crankshafts 46 are assembled so that the eccentric directions of the respective first eccentric portions 46a coincide.

  The crankshaft 46 includes a main portion 55 and a sub portion 56, and the main portion 55 and the sub portion 56 are formed separately. That is, the main portion 55 is obtained by machining one bar, and the sub-portion 56 is obtained by machining another bar. The main portion 55 is provided with eccentric portions 46a and 46b and journal portions 46d and 46e. On the other hand, the sub-portion 56 is configured so that the transmission gear 44 can be attached thereto.

  The first journal portion 46 d constitutes one end portion of the main portion 55, and the second journal portion 46 e constitutes the other end portion of the main portion 55. A concave portion 55 a is formed on the end surface of the first journal portion 46 d, that is, the front end surface of the main portion 55. The recess 55a is formed in the first journal portion 46d so as to have a circular cross section coaxial with the axis of the shaft main body 46c and to extend from the front end surface in the axial direction toward the back side of the main portion 55. ing.

  The sub portion 56 is formed in a rod shape, and one end portion of the sub portion 56 has a shape that can be fitted into the concave portion 55 a of the main portion 55. For example, the outer diameter of the sub part 56 is a dimension corresponding to the inner diameter of the recess 55a. And the one end part of the sub part 56 is inserted in the recessed part 55a of the main part 55, and it becomes the structure by which the main part 55 and the sub part 56 were mutually assembled | attached. The fitting of the sub part 56 to the main part 55 is a fitting by press fitting, shrink fitting, plastic bonding or the like.

  Spline processing is applied to the end of the sub part 56, and the transmission gear 44 is splined. The transmission gear 44 is fixed by a retaining ring 57 so as not to be displaced. Spline processing may be performed over the entire length of the sub-portion 56 (see FIG. 2).

  The shape (cross-sectional shape) of the recess 55a provided in the main portion 55 may be made common to a plurality of crankshafts 46 having different outer diameters of the journal portions 46d and 46e and different configurations of the eccentric portions 46a and 46b. . That is, the crankshafts 46 having different product numbers may have the recesses 55a having the same cross-sectional shape. In this case, the sub part 56 can be made common to the main part 55 of the crankshaft 46 of different product numbers. In addition, about the main part 55, it is set as the structure which has the cross-sectional shape from which the recessed part 55a differs in the crankshaft 46 from which a product number differs, and the aspect which makes common the outer diameter of the edge part by which the spline process was performed among the subparts 56 It is also possible. Even in this case, the transmission gear 44 can be shared.

  The sub part 56 can change the length of the axial direction suitably according to the other party member, customer specifications, etc. For example, as shown in FIG. 2, it is good also as a shape longer than the subpart 56 shown in FIG. In other words, since the crankshaft 46 is separated into the main portion 55 and the sub-portion 56, it is not necessary to prepare all the crankshafts 46 having specifications according to the counterpart member, customer specifications, etc. While the portion 55 is a common member, only the sub-portion 56 can be changed according to customer specifications.

  As shown in FIGS. 3 and 4, the recess 55a may be formed so as to extend beyond the first journal portion 46d and into the first eccentric portion 46a. In this case, it is possible to adjust the amount of insertion of the sub-part 56 into the recess 55a in accordance with the counterpart member, customer specifications, and the like. In order to adjust the amount of insertion, the spacer 59 is preferably accommodated in the recess 55a. The spacer 59 functions as positioning means for determining the axial position of the sub part 56 with respect to the main part 55. Note that the spacer 59 may be omitted.

  As shown in FIG. 1, the end plate portion 30 has a plurality of through holes 30d around a central through hole 30c. These through holes 30d are arranged at equal intervals in the circumferential direction around the central through hole 30c. A plurality of crankshafts 46 are also provided and arranged at equal intervals in the circumferential direction. Each crankshaft 46 passes through the through hole 30 d of the end plate portion 30 and is inserted into the hole portion 32 b of the substrate portion 32.

  Both the first oscillating gear 48 a and the second oscillating gear 48 b are disposed in the space between the substrate portion 32 and the end plate portion 30 of the carrier 14. The first oscillating gear 48 a and the second oscillating gear 48 b are respectively provided with a first through hole 48 c formed at the center, a second through hole 48 d through which the shaft portion 33 can pass, and the eccentricity of the crankshaft 46. A third through hole 48e through which the portions 46a and 46b can penetrate is formed.

  Roller bearings 60 are attached to the first and second eccentric portions 46a and 46b. In this state, the first eccentric portion 46a is inserted into the third through hole 48e of the first swing gear 48a, and the second eccentric portion. 46b is inserted through the third through hole 48e of the second swing gear 48b. The first and second swing gears 48 a and 48 b rotate while meshing with the internal teeth 24 of the case 12 as the first and second eccentric portions 46 b swing due to the rotation of the crankshaft 46. In the present embodiment, two swing gears 48a and 48b are provided. However, the present invention is not limited to this configuration, and one or three or more swing gears 48a and 48b may be provided. Good.

  In the eccentric oscillating gear device 10 according to the present embodiment, the input shaft is driven by the driving force of the motor, and when the input shaft rotates, the transmission gear 44 rotates. As a result, the crankshaft 46 also rotates integrally, and when the crankshaft 46 rotates, the first oscillating gear 48a rotates while meshing with the internal teeth 24 as the first eccentric portion 46a oscillates. As the portion 46 b swings, the second swing gear 48 b rotates while meshing with the internal teeth 24. As a result, the carrier 14 having the shaft portion 33 penetrating the second through hole 48d of both the oscillating gears 48a and 48b rotates relative to the case 12. As a result, the second arm rotates relative to the first arm. The rotational speed of the second arm (carrier 14) is a rotational speed that is decelerated at a predetermined ratio with respect to the rotational speed of the input shaft. That is, the speed reduction mechanism 18 rotates the carrier 14 relative to the case 12 at a rotational speed that is reduced at a predetermined ratio with respect to the rotational speed of the input shaft.

  As described above, in the present embodiment, the crankshaft 46 includes the main portion 55 provided with the journal portions 46d and 46e and the eccentric portions 46a and 46b, and the sub-portion 56 configured so that the transmission gear 44 can be attached. The main part 55 and the sub part 56 are formed separately. The sub part 56 is assembled to the main part 55. For this reason, the main part 55 and the sub part 56 can be managed separately and independently. In this case, for the main part 55, for example, the part number of the main part 55 is set for each of the different outer diameters and eccentric parts 46a, 46b of the journal parts 46d, 46e. The unit 55 can be shared. The transmission gear 44 may be configured to be attachable to the common sub-portion 56. Accordingly, the size of the fitting hole of the transmission gear 44 changes due to the different outer diameters of the journal portions 46d and 46e, thereby avoiding a situation where the transmission gear 44 has the same number of teeth but different management product numbers. can do. Therefore, an increase in the number of managed product numbers of the transmission gear 44 can be suppressed.

  In addition, the main portion 55 provided with the eccentric portions 46a and 46b and the journal portions 46d and 46e has a common configuration that is not affected by the specifications of the customer, and is connected to the front end portion of the main portion 55. It can be set as the structure which changes the length of the part 56 according to a customer's specification. For this reason, in the crankshaft 46, the main portion 55 that requires particularly troublesome processing does not depend on the specifications of the customer, and therefore it is possible to perform prospective production before the order is confirmed. When the order is confirmed, the sub part 56 is manufactured and assembled to the main part 55 to manufacture the crankshaft 46. Therefore, since it is sufficient to produce only the sub part 56 after the order is confirmed, the lead time required for production of the crankshaft 46 after the order is confirmed can be shortened.

  Further, in the journal portions 46 d and 46 e provided in the main portion 55 of the crankshaft 46, the crank bearings 51 and 52 are in contact with each other, and the journal portions 46 d and 46 e are separated from the sub portion 56. Therefore, the size of the spline and the outer diameter of the journal portions 46d and 46e can be set independently. As a result, since the outer diameters of the journal portions 46d and 46e are different, it is possible to avoid a situation in which the transmission gear 44 cannot be shared even when the number of teeth is the same. That is, in the case where the crankshaft 46 is integral, the splined portion is configured to be continuous with the journal portions 46d and 46e, so the spline size is determined by the outer diameter of the journal portions 46d and 46e. Therefore, even if the number of teeth is the same, the transmission gear 44 cannot be shared with respect to the crankshaft 46 in which the journal portions 46d and 46e have different outer diameters. On the other hand, when the journal portions 46d and 46e are separated from the splined portions as in this embodiment, the spline size is determined by the outer diameters of the journal portions 46d and 46e. It does not happen. As a result, if the number of teeth is the same, the transmission gear 44 can be shared even when the outer diameters of the journal portions 46d and 46e of the crankshaft 46 are different.

  In the present embodiment, the sub-part 56 can be fixed to the main part 55 by fitting the sub-part 56 into the recess 55 a formed on the distal end surface of the main part 55. Therefore, positioning of the sub part 56 (transmission gear 44) with respect to the main part 55 can be performed easily and reliably.

  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 sub-part 56 of the crankshaft 46 is formed in a rod shape whose outer diameter is constant over the entire axial direction, but is not limited thereto. As shown in FIG. 5, the sub-portion 56 has a step portion 56 a formed in the intermediate portion in the axial direction, a small diameter portion on one side with respect to the step portion 56 a, and the other side with respect to the step portion 56 a. It is good also as a structure which has a large diameter part which becomes. The small diameter portion has a cross-sectional shape that is fitted into a recess 55 a formed in the main portion 55. The stepped portion 56a functions as a positioning means for determining the axial position of the sub portion 56 with respect to the main portion 55 because the step portion 56a comes into contact with the distal end surface of the main portion 55 when the small diameter portion is fitted into the concave portion 55a. The large-diameter portion is splined over the entire axial direction, and the transmission gear 44 is splined to the large-diameter portion.

  In the above embodiment, the sub-part 56 is configured to be fitted into the recess 55a of the main part 55, but the main part 55 is formed with a through hole (not shown) penetrating in the axial direction instead of the recess 55a. It is good also as a structure by which the subpart 56 is inserted by this through-hole.

DESCRIPTION OF SYMBOLS 10 Eccentric oscillating gear apparatus 12 Case 12d Pin groove 14 Carrier 18 Reduction mechanism 24 Internal tooth 26 Main bearing 30 End plate part 31 Base part 32 Substrate part 33 Shaft part 44 Transmission gear 46 Crankshaft 46a 1st eccentric part 46b 2nd eccentricity Part 46c shaft body 46d first journal part 46e second journal part 48a first oscillating gear 48b second oscillating gear 51 first crank bearing 52 second crank bearing 55 main part 55a concave part 56 sub part 56a step part 59 spacer

Claims (4)

A gear device for generating a relative rotation at a rotational speed reduced with respect to an input rotational speed between a first member and a second member,
A crankshaft having a journal portion and an eccentric portion with which the crank bearing contacts;
A transmission gear attached to the crankshaft and transmitting a driving force from a driving source to the crankshaft;
A rocking gear having a through-hole into which the eccentric part is inserted and having a tooth part;
A case configured to be attachable to one of the first member and the second member;
A carrier configured to be attachable to the other of the first member and the second member,
The carrier rotatably supports the crankshaft, and the case has internal teeth that mesh with teeth of the swing gear;
The case and the carrier are concentrically rotatable relative to each other by the swing of the swing gear accompanying the rotation of the crankshaft,
The crankshaft includes a main portion provided with the eccentric portion and the journal portion, and a sub-portion provided to be fitted to an end portion of the main portion and configured to be able to attach the transmission gear. An eccentric oscillating gear device in which the main part and the sub part are assembled to each other.   The eccentric oscillating gear device according to claim 1, wherein the sub part is splined to attach the transmission gear.   The eccentric oscillating gear device according to claim 1 or 2, wherein the sub-portion is fitted in a recess formed in a front end surface of the main portion.   The eccentric oscillating gear device according to any one of claims 1 to 3, further comprising positioning means for determining an axial position of the sub part with respect to the main part.

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