JP2009287725A - Eccentric type reduction gear - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an eccentric type reduction gear wherein an eccentric portion and an intermediate portion of a crank shaft are held by a bearing, for suppressing an increase in the axial length of the crank shaft by increasing the number of roller members which can be arranged in the bearing. <P>SOLUTION: A first specified member 56 having a first cavity portion 56a into which a first eccentric portion 23a is inserted is arranged at one end of the crank shaft 23. A second specified member 57 having a second cavity portion 57a into which the first eccentric portion 23a is inserted is arranged between the first eccentric portion 23a and the intermediate portion 23e. The first specified member 56 and the second specified member 57 restrict the position of a first external tooth bearing 53 holding a first external gear 28a, in the axial direction of the crank shaft 23. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an eccentric speed reducer in which a plurality of external gears meshing with pin internal teeth rotate eccentrically with rotation of a crankshaft, and an eccentric portion and an intermediate portion of the crankshaft are rotatably held by bearings.

  In various industrial machines and the like, an eccentric type reduction gear is used as a reduction gear capable of realizing a large reduction ratio. As such an eccentric type reduction gear, a plurality of external gears meshing with pin internal teeth rotate eccentrically with the rotation of the crankshaft, and the eccentric portion and the intermediate portion of the crankshaft are rotatably held by bearings. A type speed reducer is known (see Patent Document 1). In the eccentric type speed reducer disclosed in Patent Document 1, two external gears formed as pinions (44) mesh with pin internal teeth (internal tooth pin (31)), and the crankshaft (48) It rotates eccentrically with the rotation. Further, the two eccentric portions (48a) of the crankshaft (48) are rotatably held with respect to the external gear via roller bearings (50). And the intermediate part of the crankshaft (48) formed as the large diameter part (48b) arrange | positioned between both eccentric parts (48a) is rotatably hold | maintained by the roller bearing (54).

JP 2007-85524 A (page 5-9, FIG. 1, FIG. 5-6)

  In the eccentric type speed reducer disclosed in Patent Document 1, the eccentric part and the intermediate part of the crankshaft are rotatably held by roller bearings. And as especially clearly disclosed in FIGS. 5 and 6 of Patent Document 1, in these roller bearings, the roller member is held by a cage. In a bearing that holds a roller member by such a cage, the number of roller members that can be arranged is limited in order to provide the cage. On the other hand, it is conceivable to omit the cage from the viewpoint of relaxing the limitation on the number of roller members that can be arranged in the bearing that holds the eccentric part and the intermediate part of the crankshaft.

  However, when the cage is omitted as described above, a separate structure for defining the position of the roller member in the axial direction of the crankshaft is required. As a structure for defining the position of the roller member by means other than the cage, a pair of flanges integrally formed on the crankshaft can be provided so as to hold the roller member at both ends. However, in this case, in addition to providing the flanges at positions corresponding to both ends of the roller member, in order to prevent stress concentration at the inner peripheral side of each flange, the portion continuing to the outer periphery of the crankshaft. Therefore, there is a problem that the axial length of the crankshaft becomes long.

  In view of the above circumstances, the present invention can increase the number of roller members that can be disposed in the bearing in the eccentric type reduction gear in which the eccentric portion and the intermediate portion of the crankshaft are rotatably held by the bearing. An object of the present invention is to provide an eccentric type speed reducer that can prevent the crankshaft from becoming longer in the axial direction.

  In order to achieve the above object, an eccentric speed reducer according to a first aspect of the present invention includes a case, a plurality of pin internal teeth formed as pin-shaped members disposed on the inner periphery of the case, and housed in the case. In addition, a first external gear and a second external gear provided on the outer periphery with external teeth meshing with the pin internal teeth, and a crank hole formed in the first external gear and the second external gear And a crankshaft that rotates the first external gear and the second external gear eccentrically by rotating, and the crankshaft formed in the crankshaft and disposed in the crank hole. A first eccentric portion and a second eccentric portion provided so as to be eccentric with respect to the rotation center line, and a first eccentric portion that rotatably holds the first eccentric portion with respect to the first external gear in the crank hole. 1 external bearing and the second eccentric part in front A second external gear bearing rotatably held with respect to the second external gear in the crank hole; a base carrier rotatably holding one end side of the crankshaft; and the other end side of the crankshaft. An end carrier that is rotatably held, a support that is disposed between the base carrier and the end carrier, connects the base carrier and the end carrier, is fixed to the base carrier, and a pinion is attached. And an intermediate bearing that is disposed between the first external gear and the second external gear and rotatably holds an intermediate portion of the crankshaft. In the eccentric speed reducer according to the first aspect of the present invention, the first gap member into which the first eccentric portion is inserted is formed, the first defining member disposed on one end side of the crankshaft, and the first eccentric member. And a second defining member formed between the first eccentric portion and the intermediate portion, wherein the first defining member and the second defining member are further provided. And the position of the first external bearing in the axial direction of the crankshaft is defined.

  According to this invention, the first defining member into which the first eccentric portion is inserted is disposed on one end side of the crankshaft, the second defining member is disposed between the first eccentric portion and the intermediate portion, and the second defining member is disposed. The member abuts on the step portion in which the intermediate portion of the crankshaft is formed. And the position in the axial direction of the crankshaft of the 1st external tooth bearing arrange | positioned between a 1st prescription | regulation member and a 2nd prescription | regulation member is prescribed | regulated by these prescription | regulation members. For this reason, it is not necessary to provide a cage for holding the roller member in the first external tooth bearing, and the number of roller members in the first external tooth bearing can be increased, and the filling rate of the roller member can be increased. . In addition, since the position of the first external tooth bearing in the crankshaft direction is defined by the defining member having a structure in which the gap portion inserted into the first eccentric portion is provided, it is integrated with the crankshaft such as the flange portion. There is no need for a bearing holding structure to be formed or the aforementioned notch formed together with the flange, and the crankshaft is also prevented from being elongated in the axial direction.

  Therefore, according to the present invention, it is possible to provide an eccentric type speed reducer that can increase the number of roller members that can be disposed on the bearing that holds the eccentric portion and can prevent the crankshaft from becoming longer in the axial direction. can do.

  An eccentric type speed reducer according to a second aspect of the invention is the eccentric type speed reducer according to the first aspect of the invention, wherein the crankshaft is notched along the circumferential direction on the outer periphery between the first eccentric part and the intermediate part. The first cutout portion is formed, and the first cutout portion and at least a part of the second defining member are arranged so as to overlap in a direction perpendicular to the axial direction of the crankshaft.

  According to the present invention, the first notch is formed in the outer peripheral portion of the crankshaft continuing from the first eccentric portion to the intermediate portion, and the first notch and the second defining member are perpendicular to the crankshaft direction. It is arranged by overlapping. For this reason, stress concentration is prevented in a portion that is stepped from the first eccentric portion of the crankshaft to the intermediate portion, and the length of the crankshaft in the axial direction is suppressed from being increased, The second defining member can be arranged efficiently. In addition, when providing a collar part integrally in a crankshaft, although a pair of notch part is required in the position corresponding to the both ends of a roller member, in the structure of this invention, it arrange | positions and overlaps with a 2nd prescription | regulation member. Since it is only necessary to provide the first cutout portion, the length of the crankshaft can be shortened.

  The eccentric speed reducer according to a third aspect of the present invention is the eccentric speed reducer according to the first aspect or the second aspect, wherein a third gap portion into which the second eccentric portion is inserted is formed, on the other end side of the crankshaft. A third defining member disposed; and a fourth defining member formed between the second eccentric portion and the intermediate portion, wherein a fourth gap portion into which the second eccentric portion is inserted is formed. And the third defining member and the fourth defining member define a position of the second external tooth bearing in the axial direction of the crankshaft.

  According to this invention, the third defining member into which the second eccentric portion is inserted is disposed on the other end side of the crankshaft, the fourth defining member is disposed between the second eccentric portion and the intermediate portion, and the fourth The defining member comes into contact with the step portion in which the intermediate portion of the crankshaft is formed. And the position in the axial direction of the crankshaft of the 2nd external tooth bearing arrange | positioned between a 3rd prescription | regulation member and a 4th prescription | regulation member is prescribed | regulated by these prescription | regulation members. For this reason, it is not necessary to provide a cage for holding the roller member in the second external tooth bearing, the number of roller members in the second external tooth bearing can be increased, and the filling rate of the roller member can be increased. . In addition, since the position of the second external tooth bearing in the crankshaft direction is defined by the defining member having a structure provided with a gap portion inserted in the second eccentric portion or the intermediate portion, There is no need for an integrally formed bearing holding structure or the aforementioned notch formed together with the flange, and the crankshaft is also prevented from being elongated in the axial direction.

  An eccentric type speed reducer according to a fourth aspect of the invention is the eccentric type speed reducer according to the third aspect of the invention, wherein the crankshaft is notched along the circumferential direction at the outer periphery between the second eccentric portion and the intermediate portion. The second cutout portion is formed, and the second cutout portion and at least a part of the fourth defining member are arranged to overlap each other in a direction perpendicular to the axial direction of the crankshaft.

  According to the present invention, the second cutout portion is formed in the outer peripheral portion of the crankshaft continuing from the second eccentric portion to the intermediate portion, and the second cutout portion and the fourth defining member are perpendicular to the crankshaft direction. It is arranged by overlapping. For this reason, stress concentration is prevented from occurring in a stepped portion extending from the second eccentric portion of the crankshaft to the intermediate portion, and the length of the crankshaft in the axial direction is suppressed from being increased, The fourth defining member can be arranged efficiently. Further, there is no need to provide a pair of notches at positions corresponding to both ends of the roller member as in the case where the flange is provided integrally with the crankshaft, and the second notch is arranged so as to overlap the fourth defining member. Therefore, the length of the crankshaft can be shortened.

  An eccentric type speed reducer according to a fifth aspect of the invention is the eccentric type speed reducer according to the fourth aspect of the invention, wherein a fifth gap portion into which the intermediate portion is inserted is formed and arranged in contact with the second defining member. A sixth defining member formed with a defining member and a sixth gap portion into which the intermediate portion is inserted, and disposed in contact with the fourth defining member, wherein the fifth defining member and the sixth defining member are provided. The position of the intermediate bearing in the axial direction of the crankshaft is defined by the member.

  According to this invention, the position in the axial direction of the crankshaft of the intermediate bearing disposed between the fifth defining member and the sixth defining member and holding the intermediate portion is also defined by these defining members. For this reason, it is not necessary to provide a cage for holding the roller member even in the intermediate bearing, and the number of roller members in the intermediate bearing can be increased and the filling rate of the roller member can be increased. In the intermediate portion, it is not necessary to provide a flange portion integral with the crankshaft or a notch portion formed with the flange portion, and the crankshaft is further prevented from being elongated in the axial direction.

  According to the present invention, in the eccentric type speed reducer in which the eccentric portion and the intermediate portion of the crankshaft are rotatably held by the bearing, the number of roller members that can be arranged on the bearing can be increased, and the crankshaft can be axially moved. It is possible to provide an eccentric type speed reducer that can suppress an increase in length.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The eccentric speed reducer according to the embodiment of the present invention can be widely applied to various industrial machines such as industrial robots and various machine tools, construction machines, and the like. For example, in a windmill, since the diameter of a blade (blade) tends to increase in recent years, yaw driving that is a driving device for swinging to turn the nacelle of the windmill in accordance with the wind direction. As a device, a reduction gear with a high output specification (large load capacity) is required while suppressing an increase in size. For this reason, the eccentric type speed reducer according to the present embodiment is preferably used as such a yaw drive device for a windmill. In addition to this example, a plurality of external gears meshing with the pin internal teeth rotate eccentrically with the rotation of the crankshaft, and an eccentric type in which the eccentric portion and the intermediate portion of the crankshaft are rotatably held by bearings. The speed reducer can be widely applied.

(Overall configuration of eccentric type reducer)
FIG. 1 is a cross-sectional view showing an eccentric speed reducer 1 according to an embodiment of the present invention. The eccentric speed reducer 1 is used, for example, as a windmill yaw drive device for turning a nacelle of a windmill, and decelerates rotation input from a motor 100 (partially indicated by a broken line in FIG. 1). Then transmit and output. The eccentric speed reducer 1 includes a case 11, a pin internal tooth 22, a front speed reduction part 12, a rear speed reduction part 13, an output shaft 14, and the like.

  As shown in FIG. 1, the eccentric speed reducer 1 has a pinion 101 attached to an output shaft 14 that is positioned so as to protrude from the case 11 at one end disposed on the lower side, and is disposed on the upper side. The motor 100 is attached to the case 11 on the end side. In the eccentric speed reducer 1, the rotational force input from the motor 100 disposed on the upper side is decelerated and transmitted via the front speed reducer 12 and the rear speed reducer 13 disposed in the case 11 and output. Output to the pinion 101 attached to the shaft 14. If the eccentric speed reducer 1 is used as a windmill yaw drive device, the eccentric speed reducer 1 is arranged so that the pinion 101 meshes with a gear fixed to the top of the tower of the windmill. And the eccentric type reduction gear 1 act | operates with the rotational drive force from the motor 100, and the pinion 101 rotates, and the nacelle of a windmill turns. In the following description, in the eccentric type reduction gear 1, the lower output side where the output shaft 14 is disposed is one end side, and the upper input side where the motor 100 is disposed is the other end side. explain.

(Configuration of case and pin internal teeth)
As shown in FIG. 1, the case 11 of the eccentric speed reducer 1 includes a cylindrical first case portion 11a and a second case portion 11b arranged on the other end side of the first case portion 11a. The edges are connected with bolts. In the case 11, a front-stage reduction unit 12, a rear-stage reduction unit 13, and the like are accommodated. In addition, the front stage reduction part 12 is arrange | positioned inside the 2nd case part 11b, and the rear stage reduction part 13 is arrange | positioned inside the 1st case part 11a, The front stage reduction part 12, the rear stage reduction part 13, and the output shaft 14 Are arranged in series along the axial direction which is the direction of the rotation center line P of the eccentric speed reducer 1 (illustrated by a one-dot chain line in FIG. 1). The case 11 has an opening at one end (the end of the first case 11a), and the motor 100 is fixed to the other end (the end of the second case 11b) as described above.

  FIG. 2 is an enlarged cross-sectional view showing the rear-stage deceleration unit 13 and its vicinity in FIG. 3 is a cross-sectional view taken along line AA in FIG. As shown in FIGS. 1 to 3, a pin groove 52 is provided on the inner periphery of the first case portion 11 a of the case 11. A plurality of pin grooves 52 are formed on the inner circumference of the case 11, and are provided at equal intervals along the circumferential direction on the inner circumference of the case 11. Each pin groove 52 is formed as a groove that has a semicircular arc cross section and whose longitudinal direction extends parallel to the rotation center line P.

  A plurality of pin internal teeth 22 are provided, and as shown in FIGS. 1 to 3, the pin internal teeth 22 are formed as pin-shaped members (round bar-shaped members) and arranged in pin grooves 52 provided on the inner periphery of the case 11. Has been. In FIG. 1 to FIG. 3, the pin inner teeth 22 are shown not in cross section but in outer shape. The pin internal teeth 22 are arranged so that the longitudinal direction thereof is parallel to the rotation center line P, and are arranged in a state of being fitted into the pin grooves 52 at equal intervals on the inner periphery of the case 11. It is configured to mesh with the external teeth 31 of the tooth gear 28.

(Structure of the front reduction gear)
As shown in FIG. 1, the front speed reduction unit 12 includes a one-stage planetary gear mechanism to which the rotational driving force from the motor 100 is transmitted and a spur gear 49, and the planetary gear mechanism includes the sun gear 15. , A carrier 16, a planetary gear 17, a ring gear 18 and the like.

  As shown in FIG. 1, a plurality of planetary gears 17 (three in this embodiment) are arranged around the rotating shaft 100a of the motor 100 arranged so as to protrude toward the inside of the case 11 and rotate. It is located in the radial direction (direction perpendicular to the rotation center line P) of the eccentric speed reducer 1 with respect to the shaft 100a. Each planetary gear 17 is connected to the rotary shaft 100a by meshing with a gear formed on the outer periphery of the end of the rotary shaft 100a. The carrier 16 is formed as a planetary frame that rotatably holds a plurality of planetary gears 17 at positions of equal angles along the circumferential direction around the rotation shaft 100a and performs a revolving operation. The ring gear 18 is provided as a ring-shaped gear that is fixed to the second case portion 11 b and has teeth formed on the inner periphery, and is configured to mesh with the planetary gear 17. The sun gear 15 is disposed on the rotation center line P, meshes with the spur gear 49 at one end side thereof, and is connected to the inner peripheral portion of the carrier 16 by spline coupling at the other end side.

  As shown in FIG. 1, a plurality of spur gears 49 (three in this embodiment) are arranged around the spur gear 49 so as to mesh with the sun gear 15, and the radial direction of the eccentric speed reducer 1 with respect to the sun gear 15. Is located. The spur gear 49 is fixed to the other end side of the crankshaft 23 of the rear-stage speed reduction unit 13. Accordingly, the spur gear 49 is configured to transmit a rotational force that rotates the crankshaft 23.

(Configuration of the rear stage deceleration unit)
As shown in FIG. 1, the rear speed reduction unit 13 is configured to be operated by a rotational driving force input from the motor 100 and transmitted through the front speed reduction unit 12 to transmit rotation to the output shaft 14. ing. As shown in FIGS. 1 to 3, the rear speed reduction unit 13 includes a crankshaft 23, a base carrier 25, an end carrier 26, a support 27, a first external gear 28 a and a second external gear 28 b. External gear 28, support bolt 29, plate 39, first external gear bearing 53, second external gear bearing 54, intermediate bearing 41, first to sixth defining members (56, 57, 59, 60, 58) , 61) and the like.

  As shown in FIGS. 1 to 3, a plurality of crankshafts 23 (three in the present embodiment) are arranged at equal angular positions along the circumferential direction around the rotation center line P. Are arranged so as to be parallel to the rotation center line P. Each crankshaft 23 is disposed so as to penetrate a crank hole 30 formed in a first external gear 28a and a second external gear 28b, which will be described later, and rotates to form a first external gear 28a. The second external gear 28b is provided as a shaft member that rotates eccentrically. And the crankshaft 23 will perform a revolution operation | movement with rotation of the 1st external gear 28a and the 2nd external gear 28b accompanying self rotation (autorotation). Further, each crankshaft 23 is disposed so as to also penetrate a crank plate hole 42 formed in a plate 39 to be described later. In FIGS. 1 and 2, the crankshaft 23 is shown not in cross section but in its outer shape.

  In addition, the crankshaft 23 is formed with a first eccentric portion 23a, a second eccentric portion 23b, a first shaft portion 23c, a second shaft portion 23d, and an intermediate portion 23e. The eccentric part 23a, the intermediate part 23e, the second eccentric part 23b, and the second shaft part 23d are provided in series in this order. The intermediate portion 23e has a larger diameter than the first eccentric portion 23a and the second eccentric portion 23b in the entire circumference, and a step portion is provided between the intermediate portion 23e and the first eccentric portion 23a and the second eccentric portion 23b. Is formed. The first eccentric portion 23a and the second eccentric portion 23b are formed such that a cross section perpendicular to the axial direction is a circular cross section, and the center positions of the first eccentric portion 23a and the second eccentric portion 23b are the rotation center lines of the crankshaft 23 (first shaft portion). 23c and the center position of the second shaft portion 23d). The first eccentric portion 23a is disposed in the crank hole 30 of the first external gear 28a, and the second eccentric portion 23b is disposed in the crank hole 30 of the second external gear 28b.

  A first shaft portion 23c provided on one end side of the crankshaft 23 is rotatably held via a roller bearing 34 with respect to a base carrier 25 described later, and a second shaft disposed on the other end side. The portion 23d is rotatably held via a roller bearing 35 with respect to an end carrier 26 described later. Further, a spur gear 49 is connected to the second shaft portion 23d on the other end side of the crankshaft 23 by spline coupling at an end portion thereof so as to protrude from the roller bearing 35 to the other end side. Further, the intermediate portion 23e disposed between the first eccentric portion 23a and the second eccentric portion 23b in the crankshaft 23 is formed such that a cross section perpendicular to the axial direction is a circular cross section, and its center position Is provided so as to coincide with the rotation center line of the crankshaft 23.

  As shown in FIGS. 1 to 3, the external gear 28 includes a first external gear 28 a and a second external gear 28 b that are accommodated in the case 11 in a state of being arranged in parallel. Each of the first external gear 28a and the second external gear 28b is formed with a crank hole 30 through which the crankshaft 23 passes and a column through hole 48 through which a column 27 described later passes. The first external gear 28a and the second external gear 28b are arranged so that the positions of the crank hole 30 and the column through hole 48 correspond to each other in the direction parallel to the rotation center line P.

  The crank holes 30 of the first external gear 28a and the second external gear 28b are formed as circular holes, and correspond to the crankshaft 23 in the circumferential direction of the first external gear 28a and the second external gear 28b. A plurality (three in the present embodiment) are arranged at equal angle positions along. The column through hole 48 corresponds to a cross-sectional shape of the column 27 described later, and is formed as a hole having a cross-sectional shape in which a corner portion is formed in an arc shape and has a triangular cross section that extends outward in the radial direction. Yes. A plurality of (three in the present embodiment) pillar through holes 48 are arranged at equal angular positions along the circumferential direction of the external gear 28 corresponding to the pillars 27. Moreover, the support | pillar through-hole 48 is alternately formed with the hole 30 for cranks in the circumferential direction of the 1st external gear 28a and the 2nd external gear 28b. In addition, the support | pillar 27 has penetrated the support | pillar through-hole 48 in the loose-fit state.

  In addition, external teeth 31 that mesh with the pin internal teeth 22 are provided on the outer circumferences of the first external gear 28a and the second external gear 28b. In the present embodiment, the number of teeth of the external teeth 31 of the first external gear 28 a and the second external gear 28 b is provided to be one less than the number of teeth of the pin internal teeth 22. For this reason, every time the crankshaft 23 rotates, the meshing between the meshing external teeth 31 and the pin internal teeth 22 is shifted, and the first external gear 28a and the second external gear 28b are eccentrically oscillated and rotated. Has been. The difference in the number of teeth between the external teeth 31 and the pin internal teeth 22 is not limited to one and may be plural.

  As well shown in FIGS. 2 and 3, the first external bearing 53 has the first eccentric portion 23a of the crankshaft 23 connected to the first external gear 28a in the crank hole 30 of the first external gear 28a. It is provided as a bearing that is rotatably held. The first external tooth bearing 53 includes a plurality of roller members 53a configured as needle roller members or cylindrical roller members. The first external tooth bearing 53 is not provided with a cage, and the first external tooth bearing 53 is constituted by a plurality of roller members 53a.

  As shown in FIG. 2, the second external gear bearing 54 rotates the second eccentric portion 23b of the crankshaft 23 relative to the second external gear 28b in the crank hole 30 of the second external gear 28b. It is provided as a bearing that can be freely held. Similar to the first external tooth bearing 53, the second external tooth bearing 54 includes a plurality of roller members 54 a configured as needle roller members or cylindrical roller members. The second external tooth bearing 54 is also not provided with a cage, and the second external tooth bearing 54 is constituted by a plurality of roller members 54a.

  As shown in FIG. 2, the intermediate bearing 41 is disposed between the first external gear 28 a and the second external gear 28 b, and the first eccentric portion 23 a and the second eccentric portion with respect to the crankshaft 23. 23b. The intermediate bearing 41 is provided as a bearing that rotatably holds the intermediate portion 23e of the crankshaft 23. And the intermediate bearing 41 is not provided with the holder | retainer similarly to the 1st external tooth bearing 53 and the 2nd external tooth bearing 54, and is a some roller member comprised as a needle roller member or a cylindrical roller member. 41a is provided. The intermediate bearing 41 composed of a plurality of roller members 41a is formed on a plate 39, which will be described later, via an outer ring 55 that is a cylindrical member formed with an inner peripheral surface on which the roller member 41a rolls. It is held in the crank plate hole 42.

  The first to sixth defining members (56, 57, 59, 60, 58, 61) are arranged in the axial direction of the crankshaft 23 of the first external tooth bearing 53, the second external tooth bearing 54, and the intermediate bearing 41. It is provided as a defining member that defines the position. In the present embodiment, the first to sixth defining members (56, 57, 59, 60, 58, 61) are each provided as a metal washer.

  FIG. 4 is a plan view of the first defining member 56 (FIG. 4A) and a sectional view taken along line DD (FIG. 4B), and a plan view of the third defining member 59 (FIG. c)) and its EE line arrow sectional view (Drawing 4 (d)). As shown in FIGS. 2, 4 (a), and 4 (b), the first defining member 56 is formed as a thin flat ring-shaped member, and is disposed on one end side of the crankshaft 23. The first defining member 56 is formed with a first gap portion 56a into which the first eccentric portion 23a of the crankshaft 23 is inserted. In the present embodiment, the first gap portion 56a is illustrated as a circular hole defined by a cylindrical inner peripheral surface in the first defining member 56. And the 1st prescription | regulation member 56 is the position corresponding to the part of the one end side of the 1st eccentric part 23a, the surface of the one end side opposes the other end side of the roller bearing 34, and the surface of the other end side is 1st. It arrange | positions so that the one end side of the roller member 53a of the bearing 53 for external teeth may be opposed.

  Further, as shown in FIGS. 2, 4 (c) and 4 (d), the third defining member 59 is formed as a thin flat ring-shaped member having the same shape as the first defining member 56. It is arranged on the other end side of the shaft 23. The third defining member 59 is formed with a third gap 59a into which the second eccentric portion 23b of the crankshaft 23 is inserted. In the present embodiment, the third gap portion 59a is exemplified as a circular hole defined by a cylindrical inner peripheral surface in the third defining member 59. The third defining member 59 has a surface on one end side facing the other end side of the roller member 54a of the second external tooth bearing 54 at a position corresponding to the other end portion of the second eccentric portion 23b. The other end surface is disposed so as to face one end side of the roller bearing 35.

  FIG. 5 is a plan view of the second defining member 57 (FIG. 5A), a cross-sectional view taken along the line F-F (FIG. 5B), and a plan view of the fourth defining member 60 (FIG. c)) and its GG line arrow sectional drawing (Drawing 5 (d)) are shown. As shown in FIGS. 2, 5A and 5B, the second defining member 57 is formed as a thin flat ring-shaped member, and the first eccentric portion 23a and the intermediate portion 23e of the crankshaft 23 are formed. Between. The second defining member 57 is formed with a second gap portion 57a into which the first eccentric portion 23a of the crankshaft 23 is inserted. In the present embodiment, the second gap 57a is defined by a portion defined by the cylindrical inner peripheral surface of the second defining member 57 and a tapered inner peripheral surface forming a part of a conical curved surface. The thing formed as a circular hole comprised with a part is illustrated. And the 2nd prescription | regulation member 57 has the surface of the one end side facing the other end side of the roller member 53a of the bearing 53 for 1st external teeth, and the other end side is the one end side of the 5th prescription | regulation member 58 mentioned later. Or the step of the intermediate portion 23e of the crankshaft 23.

  Further, the fourth defining member 60 is formed as a thin flat ring-shaped member having the same shape as the second defining member 57 as shown in FIGS. 2, 5 (c) and 5 (d). It arrange | positions between the 2nd eccentric part 23b of the axis | shaft 23, and the intermediate part 23e. The fourth defining member 60 is formed with a fourth gap 60a into which the second eccentric portion 23b of the crankshaft 23 is inserted. In the present embodiment, the fourth gap 60a is defined by a portion defined by the cylindrical inner peripheral surface in the fourth defining member 60 and a tapered inner peripheral surface forming a part of a conical curved surface. The thing formed as a circular hole comprised with a part is illustrated. The fourth defining member 60 has a surface on one end abutting against a surface on the other end side of a sixth defining member 61 described later, or a step portion of the intermediate portion 23e of the crankshaft 23, and a surface on the other end side. It arrange | positions so that the one end side of the roller member 54a of the 2nd external tooth bearing 54 may be opposed.

  FIG. 6 is a plan view of the fifth defining member 58 (FIG. 6A) and its HH arrow sectional view (FIG. 6B), and a plan view of the sixth defining member 61 (FIG. c)) and its II line | wire arrow sectional drawing (FIG.6 (d)) are shown. As shown in FIG. 2, FIG. 6A and FIG. 6B, the fifth defining member 58 is formed as a thin flat ring-shaped member, and comes into contact with the second defining member 57 as described above. Placed in. The fifth defining member 58 is formed with a fifth gap 58a into which the intermediate portion 23e of the crankshaft 23 is inserted. In the present embodiment, the fifth gap portion 58a is exemplified as a fifth hole 58a formed as a circular hole defined by a cylindrical inner peripheral surface. The fifth defining member 58 is in a position corresponding to the one end side portion of the intermediate portion 23e, the one end side surface abutting the other end side surface of the second defining member 57, and the other end side surface. It arrange | positions so that the one end side of the roller member 41a of the intermediate bearing 41 may be opposed.

  The sixth defining member 61 is formed as a thin flat ring-shaped member having the same shape as the fifth defining member 58, and is disposed so as to contact the fourth defining member 60 as described above. The sixth defining member 61 is formed with a sixth gap portion 61a into which the intermediate portion 23e of the crankshaft 23 is inserted. In the present embodiment, the sixth gap portion 61a is exemplified as a sixth hole 61a formed as a circular hole defined by a cylindrical inner peripheral surface. The sixth defining member 61 has a surface corresponding to the other end portion of the intermediate portion 23e, the surface on the one end side facing the other end side of the roller member 41a of the intermediate bearing 41, and the surface on the other end side. Is arranged so as to be in contact with the surface on one end side of the fourth defining member 60.

  As shown in FIG. 2, the first to sixth defining members (56, 57, 59, 60, 58, 61) are arranged as described above in the axial direction of the crankshaft 23. Therefore, the position of the first external bearing 53 in the axial direction of the crankshaft 23 is defined by the first defining member 56 and the second defining member 57. The position of the second external tooth bearing 54 in the axial direction of the crankshaft 23 is defined by the third defining member 59 and the fourth defining member 60. Further, the intermediate bearing 41 disposed between the fifth defining member 58 and the sixth defining member 61 is positioned by the fifth defining member 58 and the sixth defining member 61 in the axial direction of the crankshaft 23. It will be specified.

  FIG. 7 is an enlarged view of a part (two places) in FIG. 2, and is an enlarged cross-sectional view (FIG. 7A) of a region C circled by a broken line and a region B circled by a broken line. FIG. 7 is an enlarged sectional view (FIG. 7B). As shown in FIG. 7 (b), the crankshaft 23 has a first notch portion that is notched over the entire circumference along the circumferential direction at the outer periphery between the first eccentric portion 23a and the intermediate portion 23e. 62 is formed. In the present embodiment, the first notch 62 is illustrated as a curved surface in which the axial sectional shape of the crankshaft 23 is an arcuate curve. The second defining member 57 described above is arranged so that the first notch 62 and the second defining member 57 overlap in a direction perpendicular to the axial direction of the crankshaft 23. The second defining member 57 is arranged so as to overlap the entire width of the first notch 62 in the axial direction of the crankshaft 23. Further, the second defining member 57 is disposed so that the above-described tapered inner peripheral surface defining a part of the second gap portion 57 a faces the first cutout portion 62. Thereby, it is comprised so that interference with the 1st notch part 62 and the 2nd space | gap part 57a may be prevented.

  Further, as well shown in FIG. 7A, the crankshaft 23 has a second notch that is notched over the entire circumference along the circumferential direction at the outer periphery between the second eccentric portion 23b and the intermediate portion 23e. A notch 63 is formed. In the present embodiment, the second notch 63 is exemplified as a curved surface in which the axial cross-sectional shape of the crankshaft 23 is an arcuate curve. The fourth defining member 60 described above is arranged such that the second notch 63 and the fourth defining member 60 overlap in a direction perpendicular to the axial direction of the crankshaft 23. The fourth defining member 60 is arranged so as to overlap the entire width of the second notch 63 in the axial direction of the crankshaft 23. Further, the fourth defining member 60 is disposed such that the above-described tapered inner peripheral surface defining a part of the fourth gap 60 a faces the second notch 63. Thereby, it is comprised so that interference with the 2nd notch part 63 and the 4th space | gap part 60a may be prevented.

  When the first to sixth defining members (56, 57, 59, 60, 58, 61) are inserted into the crankshaft 23 and arranged, the fifth defining member 58 and the sixth defining member 61 are used. Is configured so that it can be inserted from either one end side or the other end side of the crankshaft 23. On the other hand, the first defining member 56 and the second defining member 57 are configured to be insertable from one end side of the crankshaft 23, and the third defining member 59 and the fourth defining member 60 are inserted from the other end side of the crankshaft 23. It is configured to be possible.

  As shown in FIGS. 1 and 2, the plate 39 is provided as a flat plate-like member having a circular outer periphery, and is disposed between the first external gear 28a and the second external gear 28b. Yes. The plate 39 is disposed in a state where a gap is formed between the outer periphery of the plate 39 and the pin inner teeth 22 (that is, the plate 39 faces the pin inner teeth 22 via the gap). . The plate 39 is provided with a crank plate hole 42 formed as a circular hole at a position of an equal angle along the circumferential direction around the rotation center line P. The plate 39 holds the intermediate bearing 41 through the outer ring 55 in the crank plate hole 42. Thereby, the crankshaft 23 is rotatably held by the intermediate portion 23e with respect to the plate 39 via the intermediate bearing 41.

  As shown in FIGS. 1 and 2, the base carrier 25 is formed integrally with the output shaft 14 on one end side thereof and is disposed in the case 11. On the other end side, the base carrier 25 is formed with a crank holding hole 50 in which the first shaft portion 23 c of the crankshaft 23 is disposed via the roller bearing 34. The crank holding hole 50 is formed at a position of an equal angle along the circumferential direction around the rotation center line P. With the crank holding hole 50, the base carrier 25 holds one end side of each crankshaft 23 rotatably at the first shaft portion 23c via the roller bearing 34.

  Further, the base carrier 25 is rotatably held on the outer peripheral side with respect to the inner peripheral side of the first case portion 11 a in the case 11 via the roller bearing 36. As shown in FIG. 1, a positioning member 44 provided as a ring-shaped member disposed along the outer periphery of the base carrier 25 is fixed to the base carrier 25. And the roller bearing 36 is arrange | positioned in the state which the one end side engaged with the positioning member 44, and the other end side engaged with the one end side of the 1st case part 11a. The positioning member 44 defines the position of the roller bearing 36 relative to the base carrier 25. In the present embodiment, the output shaft 14 is fixed to the base carrier 25 by being formed integrally with the base carrier 25.

  As shown in FIGS. 1 and 2, the end carrier 26 is connected to the base carrier 25 through a support 27 and is provided as a disk-shaped member. The end carrier 26 is rotatably held on the outer peripheral side with respect to the inner peripheral side of the case 11 via a ball bearing 37. The ball bearing 37 has one end engaged with the other end of the first case portion 11 a in the case 11, and the other end engaged with the edge 26 a projecting in a flange shape on the other end of the end carrier 26. It is arranged in the state. Further, the end carrier 26 is formed with a crank through-hole 43 in which the second shaft portion 23d on the other end side of the crankshaft 23 is disposed at an equal angle position along the circumferential direction with the rotation center line P as the center. Has been. In the crank through-hole 43, the other end side of the crankshaft 23 is rotatably held by a second shaft portion 23d via a roller bearing 35.

  Since the external gear 28, the crankshaft 23, etc. are arranged as described above, when the rotational driving force is transmitted from the spur gear 49 and the crankshaft 23 rotates together with the spur gear 49, the crankshaft 23 rotates. Accordingly, a load acts on the first external gear 28a and the second external gear 28b from the first eccentric portion 23a and the second eccentric portion 23b. Due to this load, the first external gear 28a and the second external gear 28b rotate eccentrically so as to swing, and the crank corresponding to the eccentric rotation of the first external gear 28a and the second external gear 28b. The shaft 23 performs a revolving operation while rotating. As described above, the crankshaft 23 that performs this rotational operation is supported at one end side and the other end side by the base carrier 25 and the end carrier 26, respectively, and its intermediate portion 23e is supported by the plate 39 via the intermediate bearing 41. It is supported.

  As shown in FIGS. 1 to 3, the column 27 is disposed between the base carrier 25 and the end carrier 26, and is provided as a columnar portion that connects the base carrier 25 and the end carrier 26 via a plate 39. It has been. A plurality (three in this embodiment) of the columns 27 are arranged at equal angular positions along the circumferential direction around the rotation center line P, and the axial directions thereof are parallel to the rotation center line P. Are arranged as follows. In addition, the support | pillar 27 and the crankshaft 23 are alternately arrange | positioned along the circumferential direction centering on the rotation centerline P. As shown in FIG.

  Each support column 27 includes a base-side support column portion 27 a formed integrally with the base carrier 25 and an end-side support column portion 27 b formed integrally with the end carrier 26. The base side column part 27 a is provided on the other end side of the base carrier 25 so as to protrude toward the other end side. On the other hand, the end side column part 27 b is provided so as to protrude toward one end side at one end side of the end carrier 26. Further, the base-side column part 27a and the end-side column part 27b have a triangular cross section in which a corner portion is formed in an arc shape and spreads radially outward in a cross section perpendicular to the rotation center line P. The cross-sectional shape is formed. The base-side column part 27a and the end-side column part 27b sandwich the thick part 39a that is disposed on the outer side in the radial direction on the plate 39 and formed as a part that is slightly thicker than the other parts ( Are held so as to be sandwiched). In addition, a concave portion is formed on the other end side of the base side column portion 27a and one end side of the end portion column portion 27b, and a protruding portion that engages with the concave portion is formed. Are formed in a protruding shape on one end side and the other end side of the thick portion 39a of the plate 39, respectively.

  As shown in FIGS. 2 and 3, a pillar pin hole 51 into which a pillar pin 40 described later is press-fitted is formed in the thick part 39 a of the pillar 27 and the plate 39. The support pin hole 51 is formed as a hole that opens to the other end side of the end carrier 26 and extends from the end carrier 26 to the base carrier 25 through the support 27 and the plate 39. As shown in FIG. 3, the support pin 40 is formed as a round bar-like (columnar) member that is press-fitted into the support pin hole 51. When the support pins 40 are press-fitted into the support pin holes 51, the circumferential positions of the base carrier 25 and the end carrier 26 are matched.

  Further, a pillar bolt hole 47 into which the pillar bolt 29 is inserted is formed in the thick portion 39 a of the pillar 27 and the plate 39. The strut bolt hole 47 is provided as a hole that opens to the other end side of the end carrier 26, passes through the end carrier 26 and the end side strut portion 27 b toward one end side, and further includes the plate 39 and the base side strut portion. It is formed as a hole extending through 27 a to the base carrier 25. A female screw portion is formed on the inner periphery of the portion arranged in the base carrier 25 and the base side column portion 27 a in the column bolt hole 47.

  As shown in FIGS. 1 to 3, the column bolt 29 has a threaded portion 29a formed as a male threaded portion on one end side, and a head having a hexagonal hole for tightening with a hexagonal wrench or the like on the other end. On the side. The column bolt 29 is provided as a bolt member that couples the column 27 and the base carrier 25 by screwing. The column bolt 29 couples the column 27 and the base carrier 25 so that the column carrier is supported by the column 27. 25 and the end carrier 26 are connected to each other.

  When the base carrier 25 and the end carrier 26 are connected by the connection with the support bolt 29, the support pin 40 is first press-fitted into the support pin hole 51 as described above, and the base carrier 25 and the end carrier 26 are connected. Positioning in the circumferential direction is performed. With this alignment, the support bolt 29 is inserted into the support bolt hole 47 from the other end of the end carrier 26. And the screw part 29a of the one end side of the support | pillar bolt 29 is screwed with the above-mentioned female screw part formed in the base carrier 25 in the support | pillar bolt hole 47 and the base side support | pillar part 27a. At this time, the head of the support bolt 29 engages with the other end of the end carrier 26 where the support bolt hole 47 is opened. The base carrier 25, the plate 39, and the end carrier 26 are connected by the connection by the support bolt 29.

  Further, the column bolt 29 is screwed into the base carrier 25 and the base side column portion 27a, and a clamping force for connecting the base carrier 25 and the end carrier 26 is generated, whereby the positioning member 44 fixed to the base carrier 25 is obtained. And the end carrier 26 sandwich the case 11 via the roller bearing 36 and the ball bearing 37. The end carrier 26 and the positioning member 44 sandwich the case 11 via the roller bearing 36 and the ball bearing 37, so that the base carrier 25 and the end carrier 26 are rotatably held with respect to the case 11. It will be.

(Eccentric reducer operation)
Next, the operation of the above-described eccentric speed reducer 1 will be described. The eccentric speed reducer 1 operates when the motor 100 is operated. When the operation of the motor 100 is started, the rotating shaft 100a of the motor 100 rotates. When the rotating shaft 100a rotates, the planetary gear 17 connected thereto rotates and revolves while meshing with the ring gear 18, whereby the carrier 16 rotates and the sun gear 15 connected to the carrier 16 rotates. Then, each spur gear 49 that meshes with the sun gear 15 rotates.

  When each spur gear 49 rotates, each crankshaft 23 to which each spur gear 49 is fixed at the end on the other end side rotates, and the first eccentric portion 23a and the second eccentric portion 23b rotate with each crankshaft 23. With this rotation, as described above, the first external gear 28 a and the second external gear 28 b rotate eccentrically while shifting the mesh with the pin internal teeth 22. Then, with the eccentric rotation of the first external gear 28a and the second external gear 28b, the second external gear bearing 54 is second with respect to the first external gear 28a with the first external gear bearing 53. The crankshaft 23 rotated and held with respect to the external gear 28b with respect to the plate 39 by the intermediate bearing 41 performs a revolving operation around the rotation center line P. At this time, the positions of the first external tooth bearing 53, the second external tooth bearing 54, and the intermediate bearing 41 in the axial direction of the crankshaft 23 are the first to sixth defining members (56, 57, 59, 60, 58, 61). The revolving operation of the crankshaft 23 causes the output shaft 14 to rotate together with the base carrier 25, the plate 39, and the end carrier 26 that are connected by the support column 27 and the support bolt 29, and rotatably hold the crankshaft 23. Torque is output from the pinion 101.

(Effect of eccentric type reduction gear)
According to the eccentric type reduction gear 1 described above, the first defining member 56 into which the first eccentric portion 23a is inserted is disposed on one end side of the crankshaft 23, and the first eccentric member 23a and the intermediate portion 23e are arranged between the first eccentric portion 23a and the intermediate portion 23e. The fifth defining member 58 in which the 2 defining member 57 is disposed and the intermediate portion 23 e is inserted comes into contact with the second defining member 57. And the position in the axial direction of the crankshaft 23 of the 1st external tooth bearing 53 arrange | positioned between the 1st defining member 56, the 2nd defining member 57, and the 5th defining member 58 is these defining members. (56, 57). For this reason, it is not necessary to provide a cage for holding the roller member 53a in the first external tooth bearing 53, the number of the roller members 53a in the first external tooth bearing 53 is increased, and the filling rate of the roller member 53a is increased. Can be increased. Further, the position of the first external tooth bearing 53 in the crankshaft direction is defined by the defining members (56, 57) having a structure provided with the gaps (56a, 57a) inserted into the first eccentric portion 23a. Further, there is no need for a bearing holding structure formed integrally with the crankshaft 23, such as a flange, or a notch formed with the flange, and the crankshaft 23 is also prevented from being elongated in the axial direction. The

  Further, according to the eccentric type reduction gear 1, the first notch 62 is formed in the outer peripheral portion of the crankshaft 23 continuing from the first eccentric portion 23 a to the intermediate portion 23 e, and the first notch 62 and the second specified portion are defined. The member 57 is disposed so as to overlap with the direction perpendicular to the crankshaft direction. For this reason, stress concentration at the portion of the crankshaft 23 that continues from the first eccentric portion 23a to the intermediate portion 23e is prevented from being concentrated, and the length of the crankshaft 23 in the axial direction is suppressed from increasing. The 1 notch part 62 and the 2nd prescription | regulation member 57 can be arrange | positioned efficiently. In addition, when providing a collar part integrally in the crankshaft 23, although a pair of notch part is required in the position corresponding to the both ends of a roller member, in the structure of this embodiment, the 2nd prescription | regulation member 57 and Since it is only necessary to provide the first cutout portion 62 disposed so as to overlap, the length of the crankshaft 23 can be shortened.

  Further, according to the eccentric type speed reducer 1, the third defining member 59 into which the second eccentric portion 23b is inserted is disposed on the other end side of the crankshaft 23, and the second eccentric portion 23b and the intermediate portion 23e are arranged between the second eccentric portion 23b and the intermediate portion 23e. The sixth defining member 61 into which the 4 defining member 60 is arranged and the intermediate portion 23 e is inserted contacts the fourth defining member 60. And the position in the axial direction of the crankshaft 23 of the 2nd external tooth bearing 54 arrange | positioned between the 3rd prescription | regulation member 59, the 4th prescription | regulation member 60, and the 6th prescription | regulation member 61 is these prescription | regulation members. (59, 60). For this reason, it is not necessary to provide a cage for holding the roller member 54a in the second external tooth bearing 54, and the number of roller members 54a in the second external tooth bearing 54 is increased, and the filling rate of the roller member 54a is increased. Can be increased. Further, the position of the second external tooth bearing 54 in the crankshaft direction is defined by the defining members (59, 60) having a structure provided with the gaps (59a, 60a) inserted into the second eccentric portion 23b. Further, there is no need for a bearing holding structure formed integrally with the crankshaft 23, such as a flange, or a notch formed with the flange, and the crankshaft 23 is also prevented from being elongated in the axial direction. The

  Further, according to the eccentric speed reducer 1, the position of the intermediate bearing 41, which is disposed between the fifth defining member 58 and the sixth defining member 61 and holds the intermediate portion 23e, in the axial direction of the crankshaft 23 is also determined by these. It will be defined by the defining members (58, 61). For this reason, it is not necessary to provide a cage for holding the roller member 41a in the intermediate bearing 41, and the number of the roller members 41a in the intermediate bearing 41 can be increased and the filling rate of the roller member 41a can be increased. In the intermediate portion 23e, it is not necessary to provide a flange portion integral with the crankshaft 23 or a notch portion formed together with the flange portion, and the crankshaft 23 is further suppressed from being elongated in the axial direction.

  Further, according to the eccentric type speed reducer 1, the second notch portion 63 is formed on the outer peripheral portion of the crankshaft 23 continuous from the second eccentric portion 23b to the intermediate portion 23e. The member 60 is disposed so as to overlap in a direction perpendicular to the crankshaft direction. For this reason, stress concentration at the portion of the crankshaft 23 that continues from the second eccentric portion 23b to the intermediate portion 23e is prevented from being concentrated, and the axial length of the crankshaft 23 is prevented from being increased. The two notches 63 and the fourth defining member 60 can be efficiently arranged. Further, there is no need to provide a pair of notches at positions corresponding to both end portions of the roller member as in the case where the flange portion is provided integrally with the crankshaft 23, and the second portion disposed so as to overlap the fourth defining member 60. Since only the notch 63 needs to be provided, the length of the crankshaft 23 can be shortened.

  Therefore, according to the present embodiment, it is possible to increase the number of roller members (53a, 54a, 41a) that can be disposed on the bearings (53, 54, 41) that hold the eccentric portions (23a, 23b) and the intermediate portion 23e. At the same time, the eccentric speed reducer 1 can be provided that can prevent the crankshaft 23 from becoming longer in the axial direction.

(Modification)
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. For example, the following modifications can be implemented.

(1) In the present embodiment, an explanation has been given by taking an example of an eccentric type speed reducer in which the crankshaft is arranged along the circumferential direction centering on the rotation center line. However, this need not be the case, and the crankshaft rotates. The present invention can also be applied to a center crank type speed reducer arranged on the center line. In this case, a plurality of guide crankshafts are arranged along the circumferential direction centering on the rotation center line on which the crankshaft is arranged, and the guide crankshaft rotates with the rotation of the external gear accompanying the rotation of the crankshaft (autorotation). ), The eccentric speed reducer that rotates the base carrier and the end carrier can be configured.

(2) In the present embodiment, the eccentric type reduction gear that is fixed by being provided integrally with the base carrier has been described as an example, but this need not be the case, and the output shaft may be the base. It may be an eccentric speed reducer provided as a separate member from the carrier and fixed to the base carrier.

(3) In the present embodiment, the description has been given by taking as an example a structure in which the support column is composed of a base-side support column part formed integrally with the base carrier and an end-side support column part formed integrally with the end carrier. However, this need not be the case. For example, it may be an eccentric reduction gear that is formed as a separate member from the base carrier and the end carrier, is fixed to the base carrier, and is provided with a column that connects the base carrier and the end carrier via a plate. .

(4) In the present embodiment, the case where two eccentric portions formed on the crankshaft are provided has been described as an example. However, this need not be the case, and there are three eccentric portions formed on the crankshaft. Two or more eccentric type reduction gears may be provided.

(5) In the present embodiment, an explanation has been given of an example of an eccentric type reduction gear provided with three crankshafts and struts. However, this need not be the case, and an eccentric type reduction gear provided with four or more crankshafts and posts. It may be a machine.

(6) In the present embodiment, the first gap portion of the first regulating member, the second gap portion of the second regulating member, the third gap portion of the third regulating member, the fourth gap portion of the fourth regulating member, The case where the fifth gap portion of the 5 defining member and the sixth gap portion of the sixth defining member are formed as circular holes has been described as an example, but this need not be the case. The first to sixth voids may be formed as voids other than the holes. For example, the first to sixth defining members are configured as members having a shape in which a part of the ring-shaped portion is missing. Thus, the first to sixth void portions formed as void portions having shapes other than the holes may be used.

  The present invention is an eccentric type speed reducer in which a plurality of external gears meshing with pin internal teeth rotate eccentrically with rotation of the crankshaft, and the eccentric portion and intermediate portion of the crankshaft are rotatably held by bearings. It can be widely applied.

It is sectional drawing of the eccentric type reduction gear which concerns on one embodiment of this invention. It is sectional drawing which expands and shows the back | latter stage deceleration part and its vicinity in the eccentric type reduction gear shown in FIG. It is AA arrow sectional drawing of FIG. It is the top view and sectional drawing about the 1st prescription | regulation member and 3rd prescription | regulation member in the eccentric type reduction gear shown in FIG. It is the top view and sectional drawing about the 2nd defining member and the 4th defining member in the eccentric type reduction gear shown in FIG. It is the top view and sectional drawing about the 5th defining member and the 6th defining member in the eccentric type reduction gear shown in FIG. It is an expanded sectional view about the area | region circled with the broken line in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Eccentric reducer 11 Case 14 Output shaft 22 Pin internal tooth 23 Crankshaft 23a 1st eccentric part 23b 2nd eccentric part 23e Intermediate part 25 Base carrier 26 End part carrier 27 Support | pillar 28a 1st external gear 28b 2nd external tooth Gear 30 Crank hole 31 External tooth 41 Intermediate bearing 53 First external tooth bearing 54 Second external tooth bearing 56 First defining member 56a First gap portion 57 Second regulating member 57a Second gap portion 101 Pinion

Claims (5)

Case and
A plurality of pin internal teeth disposed on the inner periphery of the case and formed as a pin-shaped member;
A first external gear and a second external gear, which are housed in the case and have external teeth meshing with the pin internal teeth on the outer periphery;
A crankshaft that passes through a hole for a crank formed in the first external gear and the second external gear and rotates the first external gear and the second external gear eccentrically by rotating. ,
A first eccentric portion and a second eccentric portion which are formed on the crankshaft, disposed in the hole for crank and provided eccentric to the rotation center line of the crankshaft;
A first external bearing for rotatably holding the first eccentric portion in the crank hole with respect to the first external gear;
A second external tooth bearing for rotatably holding the second eccentric portion with respect to the second external gear in the crank hole;
A base carrier for rotatably holding one end side of the crankshaft;
An end carrier for rotatably holding the other end of the crankshaft;
A strut disposed between the base carrier and the end carrier and connecting the base carrier and the end carrier;
An output shaft fixed to the base carrier and to which a pinion is attached;
An intermediate bearing disposed between the first external gear and the second external gear and rotatably holding an intermediate portion of the crankshaft;
An eccentric speed reducer with
A first defining member formed with a first gap portion into which the first eccentric portion is inserted and disposed on one end side of the crankshaft;
A second gap member is formed into which the first eccentric portion is inserted, and a second defining member is disposed between the first eccentric portion and the intermediate portion;
Further comprising
The eccentric speed reducer, wherein the first defining member and the second defining member define a position of the first external tooth bearing in the axial direction of the crankshaft. The eccentric speed reducer according to claim 1,
The crankshaft is formed with a first cutout portion cut out along a circumferential direction on the outer periphery between the first eccentric portion and the intermediate portion,
The eccentric speed reducer, wherein the first cutout portion and at least a part of the second defining member overlap each other in a direction perpendicular to the axial direction of the crankshaft. The eccentric speed reducer according to claim 1 or 2,
A third gap member formed with a third gap portion into which the second eccentric portion is inserted, and disposed on the other end side of the crankshaft;
A fourth gap member is formed into which the second eccentric portion is inserted, and a fourth defining member is disposed between the second eccentric portion and the intermediate portion;
Further comprising
The eccentric speed reducer characterized in that a position of the second external tooth bearing in the axial direction of the crankshaft is defined by the third defining member and the fourth defining member. The eccentric speed reducer according to claim 3,
The crankshaft is formed with a second cutout portion cut out along the circumferential direction at the outer periphery between the second eccentric portion and the intermediate portion,
The eccentric speed reducer, wherein the second cutout portion and at least a part of the fourth defining member are arranged to overlap each other in a direction perpendicular to the axial direction of the crankshaft. The eccentric speed reducer according to claim 4,
A fifth defining member formed with a fifth gap portion into which the intermediate portion is inserted and disposed in contact with the second defining member;
A sixth gap member, in which a sixth gap is formed, into which the intermediate portion is inserted, and is disposed in contact with the fourth gap member;
With
An eccentric type speed reducer characterized in that a position of the intermediate bearing in the axial direction of the crankshaft is defined by the fifth defining member and the sixth defining member.

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