JP2010014240A - Eccentric reduction gear - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten axial dimensions, and to restrain reduction in lubricity of a crankshaft bearing, in an eccentric reduction gear in which a crank transmission gear is fixed to a crankshaft. <P>SOLUTION: The crank transmission gear 49 meshing with an input gear 15 is fixed to the other end side of the crankshaft 23. The crank transmission gear 49 is provided with a gear through-hole 56 penetratingly formed so as to be opposed to a second crankshaft bearing 35 for rotatably holding the other end side of the crankshaft 23 to an end part carrier 26. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention provides an eccentric in which a plurality of external gears meshing with pin internal teeth rotate eccentrically with rotation of a crankshaft, and a crank transmission gear is fixed to a crankshaft rotatably held by a carrier. It relates to a type reduction gear.

  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 reducer, a plurality of external gears meshing with the pin internal teeth rotate eccentrically with the rotation of the crankshaft and are held rotatably on the carrier (end carrier, base carrier) in the case. There is known an eccentric type speed reducer in which a crank transmission gear is fixed to a crankshaft (see Patent Document 1). In the eccentric speed reducer disclosed in Patent Document 1, in the case (casing (158)), the two external gears (124) mesh with the pin inner teeth (pin (128A)), and the eccentric body shaft. It rotates eccentrically with the rotation of the crankshaft formed as (120). The crankshaft rotatably held with respect to the end carrier formed as the first flange body (152) and the base carrier formed as the second flange body (131) has a helical transmission gear (118). ) Formed as a crank transmission gear.

JP 2007-100903 (5th page, FIG. 1)

  In the eccentric type speed reducer disclosed in Patent Document 1, a crank transmission gear is fixed to a crankshaft, and the crank transmission gear is disposed close to the end carrier. Thus, by reducing the gap between the crank transmission gear and the carrier, the dimension of the eccentric type reduction gear in the axial direction (that is, the direction of the rotation center line of the eccentric reduction gear) can be shortened. However, when the clearance between the crank transmission gear and the carrier becomes small as in the eccentric type reduction gear disclosed in Patent Document 1, the lubricating oil in the case with respect to the crankshaft bearing that rotatably holds the crankshaft with respect to the carrier. Is difficult to flow and the lubricity of the crankshaft bearing is reduced.

  In view of the above circumstances, the present invention can reduce the axial dimension of an eccentric type reduction gear in which a crank transmission gear is fixed to a crankshaft, and also suppress a decrease in lubricity of the crankshaft bearing. An object of the present invention is to provide an eccentric type reduction gear that can be used.

  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 tooth 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 via the first crankshaft bearing; An end carrier that rotatably holds the other end side of the crankshaft via a second crankshaft bearing, and is disposed between the base carrier and the end carrier, and the base carrier and the end carrier A shaft that is fixed to the base carrier and to which a pinion is attached, a crank transmission gear that is fixed to the other end of the crankshaft, and an axial direction parallel to the axial direction of the crank transmission gear And an input gear that meshes with the crank transmission gear. In the eccentric speed reducer according to the first aspect of the present invention, the crank transmission gear is provided with a gear through hole formed so as to penetrate at least a part thereof to the second crankshaft bearing. It is characterized by.

  According to this invention, the gear transmission through hole that faces the second crankshaft bearing is formed in the crank transmission gear. For this reason, the lubricating oil in the case easily flows to the second crankshaft bearing through the gear through hole. The lubricating oil that has flowed to the second crankshaft bearing further flows along the crankshaft, and is supplied to the second external tooth bearing, the first external tooth bearing, and the first crankshaft bearing. . Even if the crank transmission gear is arranged close to the end carrier, the lubricating oil is smoothly applied to the bearings arranged along the crankshaft because the crank transmission gear is provided with a gear through hole. Can be supplied to. For this reason, the gap between the crank transmission gear and the end carrier can be reduced to fix the crank transmission gear to the crankshaft, and the axial dimension of the eccentric reduction gear can be shortened. Therefore, according to the present invention, in the eccentric type reduction gear in which the crank transmission gear is fixed to the crankshaft, the axial dimension can be shortened, and the deterioration of the lubricity of the crankshaft bearing and the external tooth bearing is also suppressed. can do.

  An eccentric speed reducer according to a second aspect of the invention is the eccentric speed reducer according to the first aspect of the invention, wherein the gear through hole is formed in the second crankshaft bearing around the rotation center line of the crankshaft in the crank transmission gear. A plurality of elements are arranged along the circumference of the opposing circles.

  According to the present invention, since the plurality of gear through holes of the crank transmission gear are arranged along the circumference of the circle facing the second crank shaft bearing, the dispersed gear through holes are changed to the second crank shaft bearing. On the other hand, lubricating oil can be supplied efficiently. Then, the lubricating oil is efficiently supplied also to the first external tooth bearing, the second external tooth bearing, and the first crankshaft bearing. For this reason, the lubricity of each bearing arranged along the crankshaft can be further improved.

  An eccentric speed reducer according to a third aspect of the present invention is the eccentric speed reducer according to the second aspect, wherein the gear through hole is formed in a long hole shape extending along the circumference of the circle, and the adjacent gear through hole A bridging portion that is disposed between and provided to bridge an inner circumferential side portion and an outer circumferential side portion of the crank transmission gear is formed in a rib shape extending in the radial direction of the circle. To do.

  According to the present invention, the bridging portion that bridges the inner peripheral portion and the outer peripheral portion of the crank transmission gear is formed in a rib shape between adjacent gear through holes formed in a long hole shape. For this reason, the rigidity of the whole crank transmission gear can be reduced by utilizing the configuration of the gear through hole. As a result, the load acting on the crank transmission gear from the input gear can be dispersed and easily released, and the contact of the crank transmission gear with respect to the input gear can be improved.

  According to the present invention, in the eccentric type speed reducer in which the crank transmission gear is fixed to the crankshaft, the axial dimension can be shortened, and the deterioration of the lubricity of the crankshaft bearing can be suppressed.

  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 reduction gear according to the present embodiment is preferably used as a yaw drive device for a windmill. In addition to this example, in the case, a plurality of external gears meshing with the pin internal teeth rotate eccentrically with the rotation of the crankshaft, and the crank transmission gear is mounted on the crankshaft rotatably held by the carrier. The fixed eccentric type reduction gear can be widely applied.

(First embodiment)
FIG. 1 is a cross-sectional view showing an eccentric type speed reducer 1 according to the first 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, transmits, and outputs the rotation input from the motor 100 disposed on the upper side. 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 positioned so as to protrude from the case 11 on one end side disposed on the lower side, and the other end side disposed on the upper side. The motor 100 is attached to the case 11. 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. When 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 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.

  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. The case 11 accommodates a front-stage reduction unit 12, a rear-stage reduction unit 13, and the like. The front-stage reduction unit 12, the rear-stage reduction unit 13, and the output shaft 14 have a rotation center line P (see FIG. 1). In FIG. 1, they are arranged in series along an axial direction which is a direction indicated by a one-dot chain line. 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.

  The second case portion 11b is provided with an oil supply port for supplying lubricating oil into the case 11, and an oil supply cap 19a is attached to the oil supply port by screwing. On the other hand, the first case portion 11a is provided with a plurality of oil discharge ports for discharging the lubricating oil supplied from the oil supply port 19a and enclosed in the case 11, and each oil discharge port has an oil discharge port cap 19b. (Only one is shown in FIG. 1) is attached by screwing. Hexagonal holes that open toward the outside of the case 11 are formed in the oil supply port cap 19a and the oil discharge port cap 19b for the operation of attaching and detaching the caps (19a, 19b) to the case 11.

  FIG. 2 is an enlarged cross-sectional view showing the rear-stage deceleration unit 13 and its vicinity in FIG. As shown in FIG. 1 and FIG. 2, a plurality of pin inner teeth 22 are provided, and are fitted into a pin groove 52 formed on the inner periphery of the first case portion 11 a to be attached to the inside of the case 11. It is arranged around the circumference. Pin internal teeth 22 (in FIG. 1 and FIG. 2, the external shape is shown in cross section) are formed as pin-shaped members (round bar-shaped members), and are arranged so that their longitudinal directions are parallel to the rotation center line P. In addition, they are arranged at equal intervals along the circumferential direction on the inner periphery of the case 11 and are configured to mesh with external teeth 31 of an external gear 28 described later.

  As shown in FIG. 1, the front speed reduction unit 12 is configured as a one-stage planetary gear mechanism to which the rotational driving force from the motor 100 is transmitted, and includes an input gear 15, a carrier 16, a planetary gear 17, a ring gear 18, and the like. It is prepared for. A plurality of (three in this embodiment) planetary gears 17 are arranged around the rotating shaft 100a of the motor 100 arranged so as to protrude toward the inside of the case 11, and are formed on one end side of the rotating shaft 100a. And is located in the radial direction of the eccentric speed reducer 1 (a direction perpendicular to the rotation center line P) with respect to the rotation 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 having teeth formed on the inner periphery and meshing with the planetary gear 17, and is fixed to a portion formed so as to project inward from a plurality of locations in the second case portion 11b. ing.

  As shown in FIGS. 1 and 2, the input gear 15 is provided as a shaft-shaped gear member and is disposed on the rotation center line P. The input gear 15 is formed with a gear portion 15a meshing with a crank transmission gear 49, which will be described later, on one end side, and a spline connected to the inner peripheral portion of the carrier 16 on the other end side. As a result, the input gear 15 is configured to input to the crank transmission gear 49 the rotational driving force from the rotating shaft 100a that has been transmitted by being decelerated via the planetary gear 17, the ring gear 18, and the carrier 16. . Note that an end portion of the input gear 15 that protrudes from the gear portion 15a toward the one end side is rotatably held with respect to the end carrier 26 via a ball bearing.

  As shown in FIGS. 1 and 2, the rear speed reduction unit 13 includes a crank transmission gear 49, a crankshaft 23, a base carrier 25, an end carrier 26, a column 27, a first external gear 28 a and a second external gear 28 b. The external gear 28, the first crankshaft bearing 34, the second crankshaft bearing 35, the first external gear bearing 53, the second external gear bearing 54, and the like.

  FIG. 3 shows a plan view of the crank transmission gear 49 (FIG. 3A) and a cross-sectional view taken along the line AA (FIG. 3B). As shown in FIGS. 1 to 3, the crank transmission gear 49 is provided as a spur gear. A plurality of crank transmission gears 49 (three in this embodiment) are arranged around the input gear 15 so as to mesh with the gear portion 15 a of the input gear 15. It is located in the radial direction. The crank transmission gear 49 and the input gear 15 are arranged so that their axial directions are parallel to each other. Further, a through hole is formed in the central portion of the crank transmission gear 49, and a spline groove 55 is formed in an inner peripheral portion of the crank transmission gear 49 that defines the through hole. In the spline groove 55, the crank transmission gear 49 is fixed to the other end side of the crankshaft 23 by spline coupling. Thereby, the crank transmission gear 49 is configured to transmit a rotational force for rotating the crankshaft 23. The crank transmission gear 49 is disposed close to the end carrier 26 via a small gap.

  Also, a plurality of gear through holes 56 are formed in the crank transmission gear 49 shown in FIGS. The gear through-hole 56 is formed in the crank transmission gear 49 so that the crank transmission gear 49 elastically deforms when the meshing with the input gear 15 and the tooth surface 58 of the crank transmission gear 49 follows the tooth surface of the input gear 15. It penetrates in the axial direction. The gear through hole 56 is formed so as to partially face the second crankshaft bearing 35 that rotatably holds the other end of the crankshaft 23 with respect to the end carrier 26. The gear through hole 56 faces the second crankshaft bearing 35 in a direction parallel to the rotation center line P. Further, the gear through-hole 56 is formed so as to expand outwardly so as to form a part of a conical curved surface at an edge portion opened to one end side surface and the other end side surface of the crank transmission gear 49. A tapered opening 56a is provided. The crank transmission gear 49 is configured so that the lubricating oil in the case 11 can easily flow through the gear through hole 56 by providing the tapered open portion 56a spreading outward. Has been.

  FIG. 4 is a plan view of the crank transmission gear 49 similar to FIG. In FIG. 4, the positions of the outer periphery and inner periphery of the second crankshaft bearing 35 facing the crank transmission gear 49 are indicated by broken lines. Further, in FIG. 4, the position of the rotation center line Q of the crankshaft 23 indicated by a one-dot chain line in FIG. As shown in FIG. 4, the plurality of gear through holes 56 are formed in a circle R (two in FIG. 4) facing the second crankshaft bearing 35 around the rotation center line Q of the crankshaft 23 in the crank transmission gear 49. It is arranged along the circumference of a virtual circle (shown by a dotted line). Each gear through hole 56 is formed in a long hole shape extending along the circumference of the circle R. As described above, the gear through hole 56 is formed in a long hole shape along the circle R, so that a large opening area can be efficiently ensured in the portion of the gear through hole 56 facing the second crankshaft bearing 35. Can do.

  Further, as shown in FIGS. 3 and 4, the bridging portion 57 arranged along the circle R between the adjacent gear through holes 56 in the crank transmission gear 49 is formed on the inner peripheral side of the crank transmission gear 49. This portion is provided so as to bridge the outer peripheral portion. And this bridge | crosslinking part 57 is formed in the rib shape extended in the radial direction of the circle | round | yen R (it is formed in the bone member shape comprised as a frame | skeleton part extended in the radial direction of the circle | round | yen R). Thus, the rigidity of the crank transmission gear 49 can be reduced because the bridging portion 57 disposed between the gear through holes 56 is formed in a rib shape. As a result, the load acting from the gear portion 15a of the input gear 15 is easily dispersed as a whole in the crank transmission gear 49 (the load is restrained from being concentrated locally and released to the entire crank transmission gear 49. Easier). Even when the output shaft 14 is inclined and the influence of the inclination is applied to the crank transmission gear 49 via the base carrier 25, the end carrier 26, and the crankshaft 23, the tooth surface 58 is connected to the input gear 15. The crank transmission gear 49 is elastically deformed so as to follow the tooth surface. For this reason, uneven contact is less likely to occur between the crank transmission gear 49 and the input gear 15, and the contact of the crank transmission gear 49 with respect to the input gear 15 can be improved.

  As shown in FIGS. 1 and 2, 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. It is arranged so that (the direction of the rotation center line Q) is parallel to the rotation center line P. Each crankshaft 23 (in FIG. 1 and FIG. 2, the outer shape is shown not in cross section) is disposed so as to penetrate the crank holes 30 formed in the first external gear 28 a and the second external gear 28 b, respectively. It is provided as a shaft member that rotates and rotates the first external gear 28a and the second external gear 28b 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, the crankshaft 23 is formed with a first eccentric portion 23a, a second eccentric portion 23b, a first shaft portion 23c, and a second shaft portion 23d, and the first shaft portion 23c and the first eccentric portion are formed from one end side. 23a, the second eccentric portion 23b, and the second shaft portion 23d are provided in series in this order. 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 each center position is provided to be eccentric with respect to the rotation center line Q of the crankshaft 23. It has been. 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 with respect to the base carrier 25 via a first crankshaft bearing 34 configured as a roller bearing. A second shaft portion 23d provided on the other end side of the crankshaft 23 is rotatably held with respect to the end carrier 26 via a second crankshaft bearing 35 configured as a roller bearing. The second crankshaft bearing 35 is disposed in a crank through hole 43 formed as a through hole in the end carrier 26, and faces the gear through hole 56 of the crank transmission gear 49 through the crank through hole 43. As described above, the crank transmission gear 49 is fixed to the second shaft portion 23d at the end portion located so as to protrude from the second crankshaft bearing 35 to the other end side.

  As shown in FIGS. 1 and 2, 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. The first external gear 28a and the second external gear 28b are respectively formed with a crank hole 30 through which the crankshaft 23 passes and a column through hole 48 through which the column 27 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 holes 48 are formed as holes corresponding to the cross-sectional shape of the column 27, and a plurality (three in this embodiment) are arranged at equal angle positions along the circumferential direction of the external gear 28 corresponding to the columns 27. Has been. 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, each time the crankshaft 23 rotates, the meshing between the meshing external teeth 31 and the pin internal teeth 22 is shifted, and the external gears 28 (28a, 28b) are eccentrically rotated. The difference in the number of teeth between the external teeth 31 and the pin internal teeth 22 may be plural.

  As shown in FIG. 2, the first external gear bearing 53 rotates the first eccentric portion 23a of the crankshaft 23 with respect to the first external gear 28a in the crank hole 30 of the first external gear 28a. It is provided as a bearing that can be freely held. The first external tooth bearing 53 includes a plurality of roller members 53a configured as needle roller members or cylindrical roller members. The second external tooth bearing 54 is a bearing that rotatably holds the second eccentric portion 23b of the crankshaft 23 with respect to the second external gear 28b in the crank hole 30 of the second external gear 28b. Is provided. 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.

  As shown in FIGS. 1 and 2, the base carrier 25 has an output shaft 14 integrally formed at one end thereof and is disposed in the case 11 (the output carrier 14 is integrally formed to form the base carrier 25). 25). The base carrier 25 is formed with a crank holding hole 50 on the other end side, and the crank holding hole 50 allows one end side of each crankshaft 23 to freely rotate at the first shaft portion 23c via the first crankshaft bearing 34. Hold on. The crank holding hole 50 is formed at a position of an equal angle along the circumferential direction around the rotation center line P. 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 11a via the roller bearing 36. A positioning member 44 provided as a ring-shaped member disposed along the outer periphery of the base carrier 25 is fixed. The roller bearing 36 is positioned with one end side engaged with the positioning member 44 and the other end side engaged with one end side of the first case portion 11a. A plurality of seals 59 are arranged between the outer periphery of the base carrier 25 and the inner periphery of the case 11 and are sealed so that the lubricating oil in the case 11 does not leak to the outside.

  As shown in FIGS. 1 and 2, the end carrier 26 is connected to the base carrier 25 via a support column 27 and is provided as a disk-shaped member. The end carrier 26 is rotatably held with respect to the inner peripheral side of the case 11 via a ball bearing 37 on the outer peripheral side thereof. The ball bearing 37 has one end engaged with the other end of the first case 11 a of the case 11, and the other end engaged with the edge 26 a protruding 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 the second shaft portion 23d via the second crankshaft bearing 35.

  As shown in FIGS. 1 and 2, 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. A plurality (three in this embodiment) of the support columns 27 are arranged at equal angular positions along the circumferential direction around the rotation center line P, and are arranged so that the axial direction thereof is parallel to the rotation center line P. ing. 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 is formed integrally with the base carrier 25 and is provided so as to protrude on the other end side of the base carrier 25. The support column 27 is formed with a support pin hole 51 that opens to the other end side of the end carrier 26 and extends to the support column 27 and into which a round bar (columnar) support pin 40 is press-fitted. As 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, the support column 27 is formed with a support bolt hole 47 that opens to the other end side of the end carrier 26 and extends to the base carrier 25 and into which a support bolt 29 indicated by a broken line in the drawing is inserted. An internal thread portion is formed on the back side of the support bolt hole 47. The column bolt 29 has a screw portion formed as a male screw portion on one end side and a head portion on which the hexagonal hole for tightening is provided on the other end side. The column bolt 29 is configured to couple the end carrier 26 and the base carrier 25 via the column 27 by screwing the screw portion with the female screw portion of the column bolt hole 47. When the base carrier 25 and the end carrier 26 are connected by the coupling with the support bolt 29, the positioning member 44 fixed to the base carrier 25 and the end carrier 26 are rolled by the tightening force generated at that time. The case 11 is clamped via the bearing 36 and the ball bearing 37 (held so as to be clamped). By this clamping, the base carrier 25 and the end carrier 26 are held rotatably with respect to the case 11.

  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 planetary gear 17 connected to the rotating shaft 100 a rotates and revolves while meshing with the ring gear 18, whereby the carrier 16 rotates and the input gear connected to the carrier 16. 15 rotates. When the input gear 15 rotates, each crank transmission gear 49 that meshes with the input gear 15 rotates, and the first eccentric portion 23a and the second eccentric portion 23b rotate together with each crankshaft 23 to which each crank transmission gear 49 is fixed. Along with this rotation, a load acts on the external gear 28 (28a, 28b) from the first and second eccentric portions (23a, 23b), and the external gear 28 (28a, 82b) is pin internal teeth 22. And rotate eccentrically so as to swing while shifting the mesh. As the external gear 28 (28a, 28b) rotates eccentrically, the first external gear bearing 53 uses the second external gear bearing 54 as the second external gear 28b. On the other hand, each of the crankshafts 23 which are held in rotation performs a revolution operation around the rotation center line P. By the revolving operation of the crankshaft 23, the output shaft 14 rotates together with the base carrier 25 and the end carrier 26 that are connected by the support column 27 and rotatably hold the crankshaft 23, and a large torque is output from the pinion 101. It will be.

  Further, during the operation described above, the lubricating oil flows in the case 11 with the operation of the crankshaft 23, the base carrier 25, the end carrier 26, and the like. The lubricating oil in the vicinity of the crank transmission gear 49 flows through the gear through hole 56 and flows toward the end carrier 26 side. Since the gear through hole 56 is formed with a tapered opening 56a, the lubricating oil easily flows into the gear through hole 56 and passes therethrough. The lubricating oil that has passed through the gear through hole 56 further passes through the crank through hole 43 and flows to the second crankshaft bearing 35. As a result, the lubricating oil is supplied to the second crankshaft bearing 35. The lubricating oil that has passed through the crank through-hole 43 also flows to the second external tooth bearing 54, the first external tooth bearing 53, and the first crankshaft bearing 34 along the axial direction of the crankshaft 23. It will follow. Thereby, sufficient lubricating oil is circulated and supplied to each bearing (34, 35, 53, 54) arranged along the crankshaft 23.

  According to the eccentric speed reducer 1 described above, the gear transmission gear 49 is formed with a gear through hole 56 that faces the second crankshaft bearing 35. For this reason, the lubricating oil in the case 11 easily flows to the second crankshaft bearing 35 through the gear through hole 56. The lubricating oil that has flowed up to the second crankshaft bearing 35 further flows along the crankshaft 23 and is supplied to the second external gear bearing 54, the first external gear bearing 53, and the first crankshaft bearing 34. Will be. Even if the crank transmission gear 49 is arranged close to the end carrier 26, the bearings (34) arranged along the crankshaft 23 are provided due to the structure in which the gear transmission hole 49 is provided in the crank transmission gear 49. , 35, 53, 54) can be smoothly supplied. For this reason, the clearance between the crank transmission gear 49 and the end carrier 26 can be reduced to fix the crank transmission gear 49 to the crankshaft 23, and the axial dimension of the eccentric speed reducer 1 can be shortened. . Therefore, according to the present embodiment, in the eccentric type reduction gear 1 in which the crank transmission gear 49 is fixed to the crankshaft 23, the axial dimension can be shortened, and the crankshaft bearings (34, 35) and the external teeth can be reduced. The reduction in lubricity of the bearings (53, 54) can also be suppressed.

  Further, according to the eccentric type reduction gear 1, a plurality of the gear through holes 56 of the crank transmission gear 49 are arranged along the circumference of the circle R facing the second crankshaft bearing 35. Lubricating oil can be efficiently supplied from the through hole 56 to the second crankshaft bearing 35. The lubricating oil is efficiently supplied also to the first external tooth bearing 53, the second external tooth bearing 54, and the first crankshaft bearing 34. For this reason, the lubricity of each bearing (34, 35, 53, 54) arrange | positioned along the crankshaft 23 can further be improved.

  Further, according to the eccentric type reduction gear 1, the bridging portion 57 that bridges the inner peripheral portion and the outer peripheral portion of the crank transmission gear 49 is formed between the adjacent gear through holes 56 formed in a long hole shape. It is formed in a rib shape. For this reason, the overall rigidity of the crank transmission gear 49 can be reduced by utilizing the configuration of the gear through hole 56. As a result, the load acting on the crank transmission gear 49 from the input gear 15 can be dispersed and easily released, and the contact of the crank transmission gear 49 with the input gear 15 can be improved.

(Second Embodiment)
Next, an eccentric type speed reducer according to a second embodiment of the present invention will be described. The eccentric speed reducer of the second embodiment is configured similarly to the eccentric speed reducer 1 of the first embodiment, but differs from the first embodiment in the configuration of the crank transmission gear 60. Hereinafter, only the crank transmission gear 60 having a configuration different from that of the crank transmission gear 49 of the first embodiment will be described, and description of the same configuration as that of the other first embodiment will be omitted.

  FIG. 5 shows a plan view of the crank transmission gear 60 (FIG. 5A) and a cross-sectional view taken along line B-B (FIG. 5B). As shown in FIG. 5, the crank transmission gear 60 is provided as a spur gear. A plurality of crank transmission gears 60 (three in this embodiment) are arranged around the input gear so as to mesh with the gear portion of the input gear having the same configuration as the input gear 15 of the first embodiment. Is located in the radial direction of the eccentric speed reducer. The crank transmission gear 60 and the input gear are arranged so that their axial directions are parallel to each other. Further, a through hole is formed in the central portion of the crank transmission gear 60, and a spline groove 69 is formed in an inner peripheral portion of the crank transmission gear 60 that defines the through hole. In the spline groove 69, the crank transmission gear 60 is fixed to the other end side of the crankshaft having the same configuration as the crankshaft 23 of the first embodiment by spline coupling. Thereby, the crank transmission gear 60 is configured to transmit a rotational force for rotating the crankshaft. The crank transmission gear 60 is disposed close to the end carrier having the same configuration as the end carrier 26 of the first embodiment via a small gap.

  In addition, a plurality of gear through holes (61 to 64) are formed in the crank transmission gear 60 shown in FIG. The gear through holes 61 and 62 and the gear through holes 63 and 64 are disposed so as to face each other in the diameter direction of the crank transmission gear 60. The gear through holes 61 and 62 are arranged on the outer side in the radial direction of the crank transmission gear 60, and the gear through holes 63 and 64 are arranged on the inner side in the radial direction of the crank transmission gear 60. The gear through holes (61 to 64) are arranged so that the crank transmission gear 60 is elastically deformed when engaged with the input gear so that the tooth surface 66 of the crank transmission gear 60 follows the tooth surface of the input gear. The gear 60 is formed to penetrate in the axial direction. In the gear through holes (61 to 64), the edge portions opened on the one end side surface and the other end side surface of the crank transmission gear 60 expand outward to form a part of a conical curved surface. The taper-shaped opening part (61a, 62a, 63a, 64a) formed in this way is provided. In the crank transmission gear 60, the tapered open portions (61 a, 62 a, 63 a, 64 a) that extend outward are provided in this way, so that the inside of the case having the same configuration as the case 11 of the first embodiment is provided. The lubricating oil is configured to easily flow through the gear through holes (61 to 64).

  FIG. 6 is a plan view of a crank transmission gear 60 similar to FIG. The gear through holes (63, 64) are formed so as to partially face the second crankshaft bearing 35 that holds the other end of the crankshaft rotatably with respect to the end carrier. In FIG. 6, the positions of the outer periphery and the inner periphery of the second crankshaft bearing 35 are indicated by broken lines, and the position of the rotation center line Q of the crankshaft is indicated by dots. Further, as shown in FIG. 6, the plurality of gear through holes (61 to 64) are formed in a circle R (see FIG. 6) facing the second crankshaft bearing 35 around the rotation center line Q of the crankshaft in the crank transmission gear 60. 6 are arranged along the circumference of a virtual circle indicated by a two-dot chain line. Each gear through hole (61 to 64) is formed in a long hole shape extending along the circumference of the circle R. Further, as shown in FIGS. 5 and 6, the crank transmission gear 60 is provided with a bridging portion 65 that bridges the inner peripheral portion and the outer peripheral portion. In this bridging portion 65, a portion including the shortest path from the inner peripheral portion to the outer peripheral portion through the adjacent gear through holes (61 and 64, 64 and 62, 62 and 63, 63 and 61). A portion extending in the circumferential direction of the crank transmission gear 60 is included.

  Further, at least one of the plurality of gear through holes (61 to 64) shown in FIG. 5 is disposed in any radial direction of the crank transmission gear. In FIG. 5A, a single gear through-hole (61-64) is a portion where only one gear through-hole (61-64) is arranged in the radial direction of the crank transmission gear 60. Arranged portions (67a, 67b, 67c, 67d) are indicated by broken lines in the figure. The plurality of gear through-holes (61-64) are gear through-holes (61, 62) in which the lengths in the radial direction of the single arrangement portions (67a-67d) are arranged outside in the radial direction of the crank transmission gear 60. The gear through-holes (63, 64) arranged on the inner side are larger than those of the above. In FIG. 5A, the radial dimension C of the gear through-hole 61 disposed on the outer side in the radial direction and the radial dimension of the gear through-hole 62 disposed on the inner side in the radial direction. Although D is illustrated by double-ended arrows, the length dimension D is configured to be larger than the length dimension C (that is, D> C).

  Further, in FIG. 5A, a plurality of arrangement portions, which are portions in which a plurality of gear through holes (61 to 64) are arranged in the radial direction of the crank transmission gear 60 by a plurality of gear through holes (61 to 64). (68a, 68b, 68c, 68d) are indicated by broken lines in the figure. The plurality of gear through-holes (61 to 64) have a single arrangement portion (the sum of the lengths in the radial direction of the plurality of arrangement portions (68a to 68d) is communicated with any of the plurality of arrangement portions (68a to 68d) ( 67a to 67d) are configured to be smaller than the length in the radial direction of the portion (67c, 67d) located on the inner side in the radial direction of the crank transmission gear 60. Further, the plurality of gear through holes (61 to 64) has a single arrangement in which the sum of the lengths in the radial direction of the plurality of arrangement portions (68a to 68d) communicates with any one of the plurality of arrangement portions (68a to 68d). Among the portions (67a to 67d), the length (67a, 67b) located on the outer side in the radial direction of the crank transmission gear 60 is configured to be larger than the length in the radial direction. In FIG. 5A, the length dimensions E and F of the plurality of arrangement portions 68a are illustrated by double-ended arrows, but the sum (E + F) of the length dimension E and the length dimension F is the plurality of arrangement portions 68a. Among the singularly arranged portions (67a, 67c) in which the hole communicates with any of 68a, the length is set to be smaller than the length D in the radial direction of the portion 67c located inside in the radial direction (that is, E + F <D) Has been. Further, the sum (E + F) of the length dimension E and the length dimension F is a portion 67a located on the outer side in the radial direction among the singularly disposed portions (67a, 67c) in which the holes communicate with any of the plurality of disposed portions 68a. It is comprised so that it may become larger than the length dimension C of radial direction (namely, E + F> C).

  According to the eccentric reduction gear of the second embodiment described above, the gear transmission gear 60 is formed with gear through holes (63, 64) facing the second crankshaft bearing 35. For this reason, the lubricating oil in the case 11 easily flows to the second crankshaft bearing 35 through the gear through holes (64, 64). Since the gear through holes (61, 62) are also opened near the second crankshaft bearing 35, the lubricating oil in the case 11 also passes through the gear through holes (61, 62) and passes through the second crankshaft. Flows up to the bearing 35. The lubricating oil that has flowed up to the second crankshaft bearing 35 further flows along the crankshaft and is supplied to the second external tooth bearing, the first external tooth bearing, and the first crankshaft bearing. Become. Further, even if the crank transmission gear 60 is arranged close to the end carrier, each of the crank transmission gears 60 arranged along the crankshaft 23 because of the structure in which the crank transmission gear 60 is provided with gear through holes (61 to 64). Lubricating oil can be smoothly supplied to the bearing. For this reason, the gap between the crank transmission gear 60 and the end carrier can be reduced to fix the crank transmission gear 60 to the crankshaft, and the axial dimension of the eccentric reduction gear can be shortened. Therefore, according to the present embodiment, in the eccentric type reduction gear in which the crank transmission gear 60 is fixed to the crankshaft, the axial dimension can be shortened, and the lubricity of the crankshaft bearing and the external tooth bearing is reduced. Can also be suppressed.

  Moreover, according to this eccentric type reduction gear, since the plurality of gear through holes (61 to 64) of the crank transmission gear 60 are arranged along the circumference of the circle R facing the second crankshaft bearing 35, the dispersion Lubricating oil can be efficiently supplied to the second crankshaft bearing 35 from the disposed gear through holes (61 to 64). Then, the lubricating oil is efficiently supplied also to the first external tooth bearing, the second external tooth bearing, and the first crankshaft bearing. For this reason, the lubricity of each bearing arranged along the crankshaft can be further improved.

  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 present invention may be applied to a center crank type eccentric speed reducer in which a crankshaft is disposed on a rotation center line. Further, the output shaft may not be integrated with the carrier but may be provided as a separate member from the carrier. Moreover, the support | pillar which connects a base carrier and an edge part carrier does not need to be integrally formed in a base carrier, and may be formed as a member different from a carrier. Also, the number of crankshafts and struts may be two or less or four or more. Further, the number of eccentric parts of the crankshaft and the number of external gears need not be two. Further, the crank transmission gear may not be a spur gear but may be a helical gear. Further, the gear through hole is not limited to those exemplified in the first and second embodiments, and the shape, the number, and the position can be variously changed.

  The present invention provides an eccentric in which a plurality of external gears meshing with pin internal teeth rotate eccentrically with rotation of a crankshaft, and a crank transmission gear is fixed to a crankshaft rotatably held by a carrier. As a type speed reducer, it can be widely applied.

It is sectional drawing of the eccentric type reduction gear in 1st Embodiment of this invention. It is sectional drawing which expands and shows the back | latter stage deceleration part and its vicinity of the eccentric type reduction gear shown in FIG. It is the top view and sectional drawing of the crank transmission gear of the eccentric type reduction gear shown in FIG. FIG. 4 is a plan view of the crank transmission gear shown in FIG. 3. It is the top view and sectional view of a crank transmission gear in a 2nd embodiment of the present invention. FIG. 6 is a plan view of the crank transmission gear shown in FIG. 5.

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 25 Base carrier 26 End carrier 27 Support | pillar 28a 1st external gear 28b 2nd external gear 30 Crank Hole 31 external tooth 34 first crankshaft bearing 35 second crankshaft bearing 49 crank transmission gear 53 first external tooth bearing 54 second external tooth bearing 56 gear through hole 101 pinion

Claims (3)

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 via a first crankshaft bearing;
An end carrier for rotatably holding the other end side of the crankshaft via a second crankshaft bearing;
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;
A crank transmission gear fixed to the other end of the crankshaft;
An input gear arranged so that an axial direction thereof is parallel to an axial direction of the crank transmission gear, and meshing with the crank transmission gear;
An eccentric speed reducer with
An eccentric type speed reducer characterized in that the crank transmission gear is provided with a gear through hole formed so as to penetrate at least a part thereof to the second crankshaft bearing. The eccentric speed reducer according to claim 1,
In the crank transmission gear, a plurality of the gear through holes are arranged along a circumference of a circle facing the second crankshaft bearing around the rotation center line of the crankshaft. Type reducer. The eccentric speed reducer according to claim 2,
The gear through hole is formed in a long hole shape extending along the circumference of the circle,
A bridging portion that is disposed between the adjacent gear through holes and is provided so as to bridge an inner peripheral portion and an outer peripheral portion of the crank transmission gear is formed in a rib shape extending in the radial direction of the circle. Eccentric reducer characterized by being

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