Rotation device

Abstract

To provide a rotation device which facilitates a work for improving driving efficiency.SOLUTION: A reduction gear 1 includes: a case 2; a first main bearing 41 and a second main bearing 42 provided on opposite sides of the case 2; and a carrier 3 supported on the case 2 via the main bearings 41, 42 in a rotational manner. The carrier 3 includes a substrate-side lubricant inlet hole 63 and an end panel side lubricant inlet hole 64 in communication with outside and with a housing part 65 defined between the carrier 3 and the case 2. Minimum opening widths Ds, De of the lubricant inlet holes 63, 64, respectively, are larger than a width between an outer race 43 and a holder 50 of each of the main bearings 41, 42 and a width between the inner race 44 and the holder 50.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a rotating device. [Background technology]

[0002] Conventionally, a so-called eccentric oscillating reduction gear has been known as a rotating device. This type of rotating device includes an internal gear (casing member), two carriers rotatably supported by the internal gear via bearings and arranged opposite each other in the direction of the rotation axis, a crankshaft (shaft body) rotatably supported by the carriers and having an eccentric portion, and an oscillating external gear arranged between the carriers. The oscillating external gear is rotatably supported by the crankshaft and meshes with the internal gear. In this way, the eccentric oscillating reduction gear has a tight combination of oscillating external gears and bearings.

[0003] A rolling bearing is used to rotatably support the internal gear and the carrier. The rolling bearing includes an outer race provided on the internal gear side, an inner race provided on the carrier side, a plurality of rolling elements disposed between the outer race and the inner race, and a cage that holds the rolling elements. In such a reduction gear transmission, the inside of the carrier is sufficiently filled with lubricant. This reduces the sliding resistance of the oscillating external gear and the meshing resistance between the internal gear and the oscillating external gear, thereby improving the drive efficiency of the rotating device. To fill the inside of the carrier with lubricant, the lubricant is injected, for example, through a gap in the bearing. The gap in the bearing is between the outer race and the cage, and between the inner race and the cage. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-124730 Summary of the Invention [Problem to be solved by the invention]

[0005] However, even if lubricant is injected through the gap in the bearing as in the conventional technology described above, the gap is narrow and it is difficult to actively inject the lubricant into the inside of the carrier, which has led to the problem that the work of improving the drive efficiency of the rotating device is cumbersome.

[0006] The present invention provides a rotation device that can facilitate the work of improving drive efficiency. [Means for solving the problem]

[0007] A rotation device according to one aspect of the present invention includes a cylindrical first rotating body, a pair of rolling bearings provided on the first rotating body and arranged on both sides of the first rotating body in the axial direction, a second rotating body arranged radially inside the first rotating body and supported by the first rotating body via the rolling bearings so as to be rotatable about a rotation axis, and a mechanical unit arranged radially inside the second rotating body, wherein the second rotating body includes an accommodating section configured between the first rotating body and the second rotating body and accommodating the mechanical unit, and a rotary shaft connected to the accommodating section and extending between the second rotating body and the accommodating section. and a hole portion arranged in the first rotating body, the rolling bearing having an outer race arranged on the first rotating body side, an inner race arranged on the second rotating body side, a plurality of rolling elements arranged between the outer race and the inner race, and a retainer arranged between the outer race and the inner race and holding the plurality of rolling elements, wherein the minimum opening width among the opening widths perpendicular to the direction in which the hole portion extends is larger than the width between the outer race and the retainer and the width between the inner race and the retainer.

[0008] This configuration allows lubricant, for example, to be easily injected from outside the second rotating body into the storage space inside the second rotating body through the hole. Furthermore, the maximum opening width of the hole is larger than the width between the outer race and the cage and the width between the inner race and the cage. This allows lubricant to be more actively injected through the hole than between the outer race and the cage or the inner race and the cage. This facilitates the task of improving the drive efficiency of the rotating device.

[0009] In the above configuration, another mechanism is provided outside the second rotating body and transmits power to the mechanism, and the hole is provided in a position exposed from the other mechanism when viewed from the axial direction.

[0010] In the above configuration, the second rotating body has a first wall portion and a second wall portion that face each other on both sides of the axial direction across the accommodating portion, and the hole portion has a first hole portion provided in the first wall portion and a second hole portion provided in the second wall portion.

[0011] In the above configuration, the first hole portion is disposed radially inward of the second hole portion.

[0012] In the above configuration, the first hole portion and the second hole portion are provided in plurality, and the first hole portion and the second hole portion are respectively arranged side by side in the circumferential direction around the rotation axis.

[0013] In the above configuration, the device is provided with a housing that covers the second rotating body, and has another storage section partitioned by the housing and the second rotating body, the other mechanism section is stored in the other storage section, and the hole section is connected to the other storage section.

[0014] In the above configuration, the first rotating body has internal teeth on its inner surface, the second rotating body has a first carrier and a second carrier that face each other in the axial direction, the mechanism portion includes a crankshaft rotatably supported by the first carrier and the second carrier, and an oscillating external gear that is accommodated in the accommodation portion and rotatably supported by the crankshaft and meshes with the internal teeth, and the hole portion is arranged in close proximity to the internal teeth.

[0015] In the above configuration, the hole portion has a first hole portion provided in the first carrier and a second hole portion provided in the second carrier, and the first hole portion is positioned radially inward from the second hole portion. [Effects of the Invention]

[0016] The above-described gearing can facilitate the task of improving drive efficiency. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 2 is a cross-sectional view of a drive device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a view taken along the arrow II in FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. [Figure 4] FIG. 3 is an exploded perspective view of a second main bearing in the embodiment of the present invention. [Figure 5] FIG. 4 is an enlarged view of a portion V in FIG. 3. [Figure 6] FIG. 6 is a view taken along the arrow VI in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0018] Next, an embodiment of the present invention will be described with reference to the drawings.

[0019] <Drive unit> FIG. 1 is a cross-sectional view of a driving device 100 in which a reduction gear transmission 1 related to a rotation device is used. As shown in FIG. 1, the driving device 100 includes a reduction gear transmission 1, an electric motor 101 connected to the reduction gear transmission 1 and disposed on both sides of the reduction gear transmission 1, and a driven member 102.

[0020] The electric motor 101 includes a motor body 103, a motor shaft 104 extending from the motor body 103, and a motor spur gear 105 provided on the motor shaft 104. The motor body 103 is, for example, a brushless motor. However, the motor body 103 is not limited to this, and may be any motor that generates rotational force. For example, a hydraulic motor or the like may also be used as the motor body 103.

[0021] The motor body 103 is attached to a housing 70 (described later) of the reduction gear 1. The motor shaft 104 protrudes through the housing 70 toward the reduction gear 1. A motor spur gear 105 is provided at the protruding tip of the motor shaft 104. The driven member 102 is, for example, the arm of a collaborative robot 106. The collaborative robot 106 is a "robot that works in cooperation with workers" in fields such as factory automation (FA).

[0022] <Deceleration device> Fig. 2 is a view taken along the line II in Fig. 1. Fig. 3 is a cross-sectional view taken along the line III-III in Fig. 2. As shown in Figures 1 to 3, the reduction gear 1 reduces the rotation speed of an electric motor 101 and outputs it. The reduction gear 1 is a so-called eccentric oscillating reduction gear. The reduction gear 1 includes a cylindrical case 2, a carrier 3 rotatably provided radially inside the case 2, and a reduction mechanism 4 connected to the carrier 3. The central axis of the case 2 and the rotation axis of the carrier 3 coincide with each other.

[0023] In the following description, the central axis and rotation axis will be referred to as the first rotation axis A1. The direction parallel to the first rotation axis A1 will be referred to as the axial direction. The rotation direction of the carrier 3 will be referred to as the circumferential direction. The radial direction of the case 2, which is perpendicular to the axial and circumferential directions, will be referred to simply as the radial direction. The central side of the case 2 in the axial direction will be referred to as the central side of the axial direction. The side opposite the central side in the axial direction will be referred to as the outer side in the axial direction.

[0024] <Case> The case 2 is made of, for example, spheroidal graphite cast iron (ductile cast iron). For example, FCD450 is used as the spheroidal graphite cast iron. An outer flange portion 2a that protrudes radially outward is integrally formed on the outer peripheral surface of the case 2. A plurality of bolt holes 2b are formed in the outer flange portion 2a. The bolt holes 2b are arranged at equal intervals in the circumferential direction. Bolts (not shown) are inserted into the bolt holes 2b and tightened to the driven member 102 to fix the reduction gear device 1.

[0025] The outer peripheral surface of the case 2, closer to the electric motor 101 than the outer flange portion 2a, functions as a fitting portion 2e into which the housing 70, described below, is fitted. An O-ring groove 2f is formed around the entire circumference of the fitting portion 2e. An O-ring (not shown) is fitted into the O-ring groove 2f. This ensures a seal between the case 2 and the housing 70. A plurality of pin grooves 2c are formed in the inner peripheral surface 2d of the case 2 along the axial direction. The pin grooves 2c are arranged at equal intervals in the circumferential direction. An internally toothed pin 5 is fitted into each pin groove 2c. The internally toothed pin 5 functions as an internal tooth that meshes with oscillating external gears 15 and 16 of the reduction mechanism 4, which will be described later.

[0026] On the inner peripheral surface 2d of the case 2, case bearing retaining surfaces 22a, 22b (first case bearing retaining surface 22a, second case bearing retaining surface 22b) are formed on both axial sides of the pin groove 2c via step surfaces 21a, 21b (first step surface 21a, second step surface 21b), respectively. Each of the case bearing retaining surfaces 22a, 22b is formed in an annular shape radially outward from the pin groove 2c. Of the two case bearing retaining surfaces 22a, 22b, the first case bearing retaining surface 22a is provided with a first main bearing 41. Of the two case bearing retaining surfaces 22a, 22b, the second case bearing retaining surface 22b is provided with a second main bearing 42.

[0027] <Main bearing> The main bearings 41, 42 have the same configuration and are arranged symmetrically about the axial center of the case 2. For this reason, in the following explanation, only the second main bearing 42 will be explained, and the first main bearing 41 will be assigned the same reference numeral as the second main bearing 42 and will not be explained in detail.

[0028] Fig. 4 is an exploded perspective view of the second main bearing 42. Fig. 5 is an enlarged view of a portion V in Fig. 3. 3 to 5, the second main bearing 42 is a so-called tapered roller bearing. The second main bearing 42 includes an annular outer race 43 fitted onto the first case bearing retaining surface 22a, an annular inner race 44 arranged radially inside the outer race 43, a plurality of rolling elements 45 arranged between the outer race 43 and the inner race 44, and a cage 50 that retains the plurality of rolling elements 45 at equal intervals in the circumferential direction.

[0029] The outer race 43 is formed in an annular shape centered on the first rotation axis A1. The outer race 43 has a triangular cross section along the axial direction. An end face 43a on the axial center side of the outer race 43 of each main bearing 41, 42 abuts against the corresponding stepped surface 21a, 21b. This positions each main bearing 41, 42 in the axial direction relative to the case 2. An outer ring raceway surface 43b inclined with respect to the axial direction is formed on the inner peripheral surface of the outer race 43. Specifically, the outer ring raceway surface 43b is inclined so that the inner diameter gradually increases toward the outside in the axial direction. The outer race 43 of each of the main bearings 41, 42 is located closer to the center in the axial direction than the inner race 44.

[0030] The inner race 44 is integrally formed with an inner race body 46 having a triangular cross section along the axial direction and a protrusion 47 that protrudes toward the center in the axial direction from the end of the inner race body 46 that is closest to the center in the axial direction. The inner circumferential surface 46a of the inner race body 46 and the inner circumferential surface 47a of the protrusion 47 are located on the same plane and are parallel to the axial direction. The outer circumferential surface 47b of the protrusion 47 is also parallel to the axial direction. An inner ring raceway surface 46b that is inclined relative to the axial direction is formed on the outer peripheral surface of the inner race body 46. Specifically, the inner ring raceway surface 46b is inclined so that the outer diameter gradually increases toward the outside in the axial direction. The inner ring raceway surface 46b faces the outer ring raceway surface 43b.

[0031] A flange 48 that protrudes radially outward is integrally formed on the axially outer end of the inner ring raceway surface 46b. The flange 48 protrudes axially outward beyond the outer race 43. The flange 48 has a triangular cross section along the axial direction. That is, the flange 48 has a flange inner peripheral surface 48a that is continuous with the inner ring raceway surface 46b and a flange outer peripheral surface 48b that faces radially outward. The flange inner peripheral surface 48a is perpendicular to the inner ring raceway surface 46b. The flange outer peripheral surface 48b is aligned along the axial direction.

[0032] Each rolling element 45 is a tapered roller having a truncated cone shape. The central axis A2 of the rolling element 45 is inclined with respect to the axial direction so as to follow the inclination direction of the outer ring raceway surface 43b and the inner ring raceway surface 46b. The rolling elements 45 are arranged at equal intervals in the circumferential direction. The movement of each rolling element 45 in the direction of the central axis A2 is restricted when the outer axial end face 45a of each rolling element 45 abuts against the flange inner peripheral surface 48a. As a result, each rolling element 45 revolves around the first rotation axis A1 while rolling on the outer ring raceway surface 43b and the inner ring raceway surface 46b.

[0033] The cage 50 is integrally formed with an annular small diameter ring 51 located closer to the center in the axial direction than the rolling elements 45, a large diameter ring 52 located axially outward than the rolling elements 45, and a plurality of pillar portions 53 connecting the small diameter ring 51 and the large diameter ring 52. The small diameter ring 51 is located radially between the outer ring raceway surface 43b and the inner peripheral surface 47a of the protrusion 47 of the inner race 44. The large diameter ring 52 faces the flange outer peripheral surface 48b in the radial direction. The large diameter ring 52 is located axially outward than the outer race 43.

[0034] The pillars 53 extend in the axial and radial directions and are arranged at equal intervals in the circumferential direction. The rolling elements 45 are arranged in pockets 54 defined by the pillars 53, the small diameter ring 51, and the large diameter ring 52. In this way, the rolling elements 45 are held by the cage 50.

[0035] In each of the main bearings 41, 42, a first gap G1 is formed between the outer race 43 and the cage 50, and a second gap G2 is formed between the inner race 44 and the cage 50. More specifically, the first gap G1 is the gap between the outer ring raceway surface 43b and the column portion 53. The width of the first gap G1 is the width between the outer ring raceway surface 43b and the column portion 53. The second gap G2 is the gap between the rib outer peripheral surface 48b and the large diameter ring 52. The width of the second gap G2 is the width between the rib outer peripheral surface 48b and the large diameter ring 52. In other words, the width between the outer race 43 and the cage 50 and the width between the inner race 44 and the cage 50 refer to the outer axial widths of both axial sides of each of the main bearings 41, 42. The carrier 3 is rotatably supported on the case 2 via the main bearings 41 and 42.

[0036] <Career> The carrier 3 includes a disk-shaped base plate portion (an example of a first carrier in the claims) 7 and an end plate portion (an example of a second carrier in the claims) 8, which are arranged axially opposite each other. The base plate portion 7 and the end plate portion 8 are made of, for example, spheroidal graphite cast iron (ductile cast iron). For example, FCD450 is used as the spheroidal graphite cast iron.

[0037] <Board section> FIG. 6 is a view taken along the arrow VI in FIG. 3 and 6, the base plate portion 7 is formed in a disk shape. A base plate bearing holding surface 7c is formed on the outer peripheral surface 7a of the base plate portion 7 at a location facing the first case bearing holding surface 22a in the radial direction. The base plate bearing holding surface 7c is formed in an annular shape radially inward from the outer peripheral surface 7a via a step portion 7b.

[0038] An inner race 44 of the first main bearing 41 is fitted onto the base plate bearing holding surface 7c. An outer end face 44a of the inner race 44 of the first main bearing 41 in the axial direction abuts against the stepped portion 7b. This positions the first main bearing 41 in the axial direction relative to the base plate portion 7. A seal portion 24 is provided between the outer peripheral surface 7a of the base plate portion 7 and the inner peripheral surface 2d of the case 2, on the opposite side of the first main bearing 41 from the end plate portion 8. The seal portion 24 ensures sealing between the base plate portion 7 and the case 2.

[0039] A base plate shaft insertion hole 7d is formed in the radial center of the base plate portion 7. A shaft bearing 20 is provided in the base plate shaft insertion hole 7d. The shaft bearing 20 is, for example, a tapered roller bearing. A plurality of crank insertion recesses 7e (for example, three in this embodiment) are formed around the base plate shaft insertion hole 7d in the base plate portion 7. Each crank insertion recess 7e is formed on a first end face 7f of the base plate portion 7 on the end plate portion 8 side. The crank insertion recesses 7e are arranged at equal intervals in the circumferential direction. A crank bearing 18 is provided in each crank insertion recess 7e. The crank bearing 18 is, for example, a tapered roller bearing.

[0040] Three pillar portions 9 are formed on the first end face 7f of the base plate portion 7 so as to protrude toward the end plate portion 8. The pillar portions 9 are formed in a triangular prism shape so that the circumferential width gradually increases toward the radially outer side as viewed in the axial direction. Each pillar portion 9 is disposed between adjacent crank insertion recesses 7e in the circumferential direction. The three pillar portions 9 are disposed at equal intervals in the circumferential direction.

[0041] Three female screw portions 26 are formed on the tip surface 9a of each column portion 9. The three female screw portions 26 are arranged at each corner of the column portion 9 when viewed in the axial direction. One post pin hole 27 is formed on the tip surface 9a of each column portion 9. The post pin hole 27 is arranged on the radially outer side of the tip surface 9a of the column portion 9 and between two female screw portions 26 that are adjacent in the circumferential direction. These female screw portions 26 and post pin holes 27 are used to integrate the base plate portion 7 and the end plate portion 8 (details will be described later).

[0042] A recess 61 is formed in the radial center of a second end face 7g of the base plate 7, which is opposite the end plate 8. The recess 61 is formed in a circular shape when viewed in the axial direction. A plurality of mounting holes 59 are formed in the outer periphery of the second end face 7g of the base plate 7. The mounting holes 59 are arranged at equal intervals in the circumferential direction. A driven member 102 (see FIG. 1) is attached to the second end face 7g of the base plate 7 using each mounting hole 59. A crank through hole 62 is formed in the radial center of each crank insertion recess 7e in the base plate portion 7. The crank through hole 62 passes through the base plate portion 7 in the axial direction and communicates with each crank insertion recess 7e and the recess 61.

[0043] A plurality of (for example, three in this embodiment) substrate-side lubricant inlet holes 63 are formed in the substrate portion 7. The substrate-side lubricant inlet holes 63 are arranged around the substrate shaft insertion hole 7d at regular intervals in the circumferential direction. In other words, the substrate-side lubricant inlet holes 63 are arranged at regular intervals in the circumferential direction around the first rotation axis A1. More specifically, the substrate-side lubricant inlet holes 63 are arranged radially inward of the crank through holes 62 and between two circumferentially adjacent crank through holes 62. The substrate-side lubricant inlet holes 63 axially penetrate the substrate portion 7 and communicate with the second end face 7g of the substrate portion 7 and the recess 61.

[0044] The substrate-side lubricant inlet hole 63 is formed in a uniform circular shape when viewed in the axial direction. The minimum opening width Ds of the substrate-side lubricant inlet hole 63 is larger than the width of the first gap G1 and the width of the second gap G2 in each of the main bearings 41, 42. The minimum opening width Ds of the substrate-side lubricant inlet hole 63 is the width perpendicular to the direction of the axis Ahs of the substrate-side lubricant inlet hole 63, and is the smallest of these widths. Since the substrate-side lubricant inlet hole 63 is formed in a uniform circular shape when viewed in the axial direction, the minimum opening width Ds of the substrate-side lubricant inlet hole 63 is the same as the diameter of the substrate-side lubricant inlet hole 63.

[0045] <End plate> 2 and 3, the end plate portion 8 is formed in a disk shape. An end plate bearing retaining surface 8c is formed on the outer peripheral surface 8a of the end plate portion 8 at a location facing the second case bearing retaining surface 22b in the radial direction. The end plate bearing retaining surface 8c is formed in an annular shape radially inward from the outer peripheral surface 8a via a stepped portion 8b.

[0046] The inner race 44 of the second main bearing 42 is fitted onto the end plate bearing retaining surface 8c. The axially outer end face 44a of the inner race 44 of the second main bearing 42 abuts against the stepped portion 8b via the spacer 66. This positions the second main bearing 42 in the axial direction relative to the end plate portion 8. An end plate shaft insertion hole 8d is formed in the radial center of the end plate portion 8. The end plate shaft insertion hole 8d is arranged coaxially with the base plate shaft insertion hole 7d. A shaft bearing 20 is provided in each end plate shaft insertion hole 8d, similar to the base plate shaft insertion hole 7d.

[0047] A plurality of crank insertion holes 8e (for example, three in this embodiment) are formed around the end plate shaft insertion hole 8d in the end plate portion 8. The crank insertion holes 8e are arranged at equal intervals in the circumferential direction. Each crank insertion hole 8e is arranged coaxially with the crank insertion recess 7e of the base plate portion 7. That is, the central axes A2 of the crank insertion hole 8e and the crank insertion recess 7e, which are opposed in the axial direction, are parallel to the first rotation axis A1. A crank bearing 18 is provided in each crank insertion hole 8e, similar to the crank insertion recess 7e.

[0048] The end plate portion 8 is formed with three bolt insertion holes 76 and three end plate pin holes 77 at locations axially opposing the column portion 9 of the base plate portion 7. The three bolt insertion holes 76 are arranged coaxially with the female thread portion 26 of the column portion 9. The end plate pin hole 77 is arranged coaxially with the column pin hole 27.

[0049] Bolts 91 are inserted into these three bolt insertion holes 76 from the side opposite to the base plate portion 7, and each bolt 91 is tightened into the female thread portion 26. Pins 92 are inserted or press-fitted into the end plate pin holes 77 and the column pin holes 27. This allows the base plate portion 7 and end plate portion 8 to be positioned with high precision, and then the end plate portion 8 is fixed to the base plate portion 7. With the end plate 8 fixed to the base plate 7, a housing portion 65 is formed between the base plate 7 and the end plate 8. The housing portion 65 has a width equal to the height of the column 9, and is defined by the base plate 7, the end plate 8, and the case 2. In other words, the housing portion 65 is located between the first main bearing 41 provided on the base plate 7 and the second main bearing 42 provided on the end plate 8.

[0050] A plurality of (for example, three in this embodiment) end plate side lubricant inlet holes 64 are formed in the end plate portion 8. The end plate side lubricant inlet holes 64 are arranged at regular intervals in the circumferential direction around the first rotation axis A1. More specifically, the end plate side lubricant inlet holes 64 are arranged at regular intervals in the circumferential direction on the outer periphery of the end plate portion 8, radially inward of the second main bearing 42.

[0051] The end plate side lubricant inlet hole 64 is disposed near the second main bearing 42 and near a radially outer corner of the column portion 9 of the base plate portion 7 when viewed from the axial direction. In other words, the end plate side lubricant inlet hole 64 is disposed radially side by side with the second main bearing 42. Therefore, the end plate side lubricant inlet hole 64 is disposed radially outward of the base plate side lubricant inlet hole 63. The end plate side lubricant inlet hole 64 is disposed close to the internal tooth pin 5 of the case 2.

[0052] The end plate side lubricant inlet hole 64 penetrates the end plate portion 8 in the axial direction and communicates with the storage portion 65. The end plate side lubricant inlet hole 64 is formed in a uniform circular shape when viewed in the axial direction. The minimum opening width De of the end plate side lubricant inlet hole 64 is larger than the width of the first gap G1 and the width of the second gap G2 in each of the main bearings 41, 42. The minimum opening width De of the end plate side lubricant inlet hole 64 is the width perpendicular to the direction of the axis Ahe of the end plate side lubricant inlet hole 64 and is the smallest of these widths. Because the end plate side lubricant inlet hole 64 is formed in a uniform circular shape when viewed in the axial direction, the minimum opening width De of the end plate side lubricant inlet hole 64 is the same as the diameter of the end plate side lubricant inlet hole 64.

[0053] <Deceleration mechanism> The reduction mechanism 4 reduces the rotation of the electric motor 101 at a fixed ratio to rotate the carrier 3. The reduction mechanism 4 mainly comprises an input shaft 80 inserted into the base shaft insertion hole 7d and the end plate shaft insertion hole 8d, an input spur gear 82 provided on the input shaft 80, three crankshafts 13 inserted into the crank insertion recesses 7e of the base portion 7 and the crank insertion holes 8e of the end plate portion 8, a transmission spur gear 14 provided on the crankshafts 13, and two oscillating external gears 15, 16 (a first oscillating external gear 15 and a second oscillating external gear 16) provided between the base portion 7 and the end plate portion 8.

[0054] The input shaft 80 is rotatably supported by the carrier 3 (base plate portion 7 and end plate portion 8) via each shaft bearing 20. An end portion 80a of the input shaft 80 on the end plate portion 8 side protrudes outward in the axial direction from the end plate portion 8. External teeth 80b are formed on the protruding end portion 80a of the input shaft 80.

[0055] A support shaft 81 that protrudes axially outward is integrally formed at an end 80a of the input shaft 80. The support shaft 81 is disposed coaxially with the input shaft 80. The diameter of the support shaft 81 is smaller than the diameter of the input shaft 80. An input spur gear 82 is fitted and fixed to the support shaft 81. External teeth 82a are formed on the outer periphery of the input spur gear 82. The external teeth 82a are meshed with a motor spur gear 105 of the electric motor 101. As a result, the input shaft 80 rotates as the motor shaft 104 rotates.

[0056] The crankshaft 13 is rotatably supported by the carrier 3 (the base plate portion 7 and the end plate portion 8) via crank bearings 18. The crankshaft 13 has a shaft main body 13c that rotates about a central axis A2, and a first eccentric portion 13a and a second eccentric portion 13b formed in the axial center of the shaft main body 13c. Hereinafter, the central axis A2 will be referred to as the second rotation axis A2 of the crankshaft 13. Both axial ends of the shaft body 13c are rotatably supported by the carrier 3 (the base plate portion 7 and the end plate portion 8) via crank bearings 18. An end portion 13d of the shaft body 13c on the end plate portion 8 side protrudes outward in the axial direction from the end plate portion 8 via the crank bearing 18.

[0057] The first eccentric portion 13a and the second eccentric portion 13b are eccentric from the second rotation axis A2. The first eccentric portion 13a and the second eccentric portion 13b are disposed adjacent to each other in the axial direction between the two crank bearings 18. In other words, the first eccentric portion 13a and the second eccentric portion 13b are disposed adjacent to each other in the axial direction between the base plate portion 7 and the end plate portion 8. The first eccentric portion 13a and the second eccentric portion 13b are disposed with a phase angle shift of 180°. The inner peripheral surface of each of the eccentric portions 13a, 13b is fitted with a roller bearing 19. The roller bearing 19 is, for example, a cylindrical roller bearing. The first oscillating external gear 15 and the second oscillating external gear 16 are rotatably supported on each of the crankshafts 13 via the roller bearings 19.

[0058] The first oscillating external gear 15 and the second oscillating external gear 16 are disposed in the accommodating portion 65. The first oscillating external gear 15 and the second oscillating external gear 16 overlap in the axial direction. Through holes 15a, 16a are formed in the first oscillating external gear 15 and the second oscillating external gear 16. The outer peripheral surfaces of roller bearings 19 are fitted into the through holes 15a, 16a, respectively. As a result, when the first eccentric portion 13a and the second eccentric portion 13b are oscillatingly rotated by the rotation of the crankshaft 13, the first oscillating external gear 15 and the second oscillating external gear 16 are oscillatingly rotated via the roller bearings 19.

[0059] The first oscillating external gear 15 and the second oscillating external gear 16 are respectively formed with openings 15b, 16b to avoid interference with the column portion 9. Shaft insertion holes 15c, 16c are formed in the radial centers of the first oscillating external gear 15 and the second oscillating external gear 16. External teeth 15d, 16d are formed on the outer periphery of the first oscillating external gear 15 and the outer periphery of the second oscillating external gear 16, respectively. The number of teeth of each of the external teeth 15d, 16d is, for example, one less than the number of internal tooth pins 5 of the case 2.

[0060] A transmission spur gear 14 is fitted and fixed to the end 13d of each crankshaft 13 (each shaft body 13c). The shaft body 13c and the transmission spur gear 14 are coaxially arranged and integrated. External teeth 17 are formed on the outer periphery of the transmission spur gear 14. The external teeth 17 are meshed with the external teeth 80b of the input shaft 80.

[0061] As described above, the reduction gear mechanism 4 is roughly divided into an internal mechanism portion (an example of a mechanism portion in the claims) 85 housed inside the carrier 3 (housing portion 65), and an external mechanism portion (an example of another mechanism portion in the claims) 86 provided outside the carrier 3. The internal mechanism portion 85 includes the internally toothed pin 5, each crankshaft 13, each oscillating externally toothed gear 15, 16, and the input shaft 80. The external mechanism portion 86 includes the external teeth 80b of the input shaft 80, the input spur gear 82, and the transmission spur gear 14.

[0062] 2, the end plate side lubricant inlet hole 64 formed in the end plate portion 8 of the carrier 3 is exposed from the external mechanism portion 86 when viewed in the axial direction. More specifically, the end plate side lubricant inlet hole 64 is disposed at a location where the outer circumferential edge of the end plate side lubricant inlet hole 64 and the outer circumferential edge of the transmission spur gear 14 slightly overlap when viewed in the axial direction.

[0063] <Housing> Returning to FIG. 1 , a housing 70 is provided on the end plate 8 side of the reduction gear transmission 1 so as to cover the end plate 8. The housing 70 is formed in a cylindrical shape with a bottom, and includes a peripheral wall 71 and a bottom wall 72. The peripheral wall portion 71 is formed in a stepped shape. The peripheral wall portion 71 has a large-diameter peripheral wall 71a provided on the opening 70a side of the housing 70, a step portion 71b formed on the bottom wall portion 72 of the large-diameter peripheral wall 71a, and a small-diameter peripheral wall 71c connected to the large-diameter peripheral wall 71a via the step portion 71b. The outer diameter of the small-diameter peripheral wall 71c is smaller than the outer diameter of the large-diameter peripheral wall 71a.

[0064] An outer flange 73 extending radially outward is formed at the tip of the large-diameter peripheral wall 71a on the side opposite the bottom wall 72. The inner circumferential surface of the large-diameter peripheral wall 71a is fitted into the fitting portion 2e of the case 2 with the opening 70a facing the reduction gear 1. At this time, the outer flange 73 of the housing 70 abuts against the outer flange 2a of the case 2. This positions the case 2 and the housing 70 in the axial direction. By fitting the large-diameter peripheral wall 71a into the case 2, a lubricant reservoir 74 is formed inside the housing 70, partitioned by the housing 70, the case 2, and the end plate 8.

[0065] An electric motor 101 is attached to the surface of the bottom wall 72 opposite to the reduction gear mechanism 4. A shaft insertion hole 72a is formed through the bottom wall 72 at the location where the electric motor 101 is attached. A motor shaft 104 is inserted into this shaft insertion hole 72a. As a result, the motor shaft 104 protrudes through the housing 70 toward the reduction gear 1. In addition to the shaft insertion hole 72a, a lubricant injection hole 72b is formed through the bottom wall portion 72. Lubricant L (shown by hatching in FIG. 1) is injected into the lubricant reservoir 74 through this lubricant injection hole 72b.

[0066] <Lubricant filling path> Next, the filling path of the lubricant L will be described with reference to FIG. The lubricant L poured into the lubricant reservoir 74 flows into the accommodation portion 65 through the end plate-side lubricant inlet hole 64 (see arrow Y1 in FIG. 1). At this time, in addition to the end plate-side lubricant inlet hole 64, other paths through which the lubricant flows from the lubricant reservoir 74 into the interior (accommodation portion 65) of the carrier 3 include the first gap G1 and the second gap G2 of the second main bearing 42 (see FIG. 5). However, the minimum opening width De of the end plate-side lubricant inlet hole 64 is larger than the width of the first gap G1 and the width of the second gap G2. Therefore, the lubricant L actively flows into the accommodation portion 65 through the end plate-side lubricant inlet hole 64.

[0067] Moreover, the end plate side lubricant inlet hole 64 is exposed from the external mechanism part 86 (transmission spur gear 14) when viewed from the axial direction. Therefore, resistance to the lubricant L flowing into the end plate side lubricant inlet hole 64 is reduced compared to, for example, a case where the end plate side lubricant inlet hole 64 is formed in a recessed portion of the transmission spur gear 14. Therefore, the lubricant L flows smoothly into the end plate side lubricant inlet hole 64.

[0068] The end plate side lubricant inlet holes 64 are arranged at regular intervals in the circumferential direction on the outer periphery of the end plate portion 8, radially inward of the second main bearing 42. That is, the end plate side lubricant inlet holes 64 are arranged close to the internally toothed pins 5 of the case 2. As a result, the lubricant L flowing into the accommodating portion 65 is filled in the accommodating portion 65 sequentially, starting from the vicinity of the internally toothed pins 5. For this reason, the lubricant L is actively applied to the internally toothed pins 5 and the meshing portions of the external teeth 15d, 16d of the oscillating external gears 15, 16.

[0069] The substrate-side lubricant inlet 63 formed in the substrate portion 7 functions as an air vent when the lubricant L flows into the storage portion 65. Here again, the minimum opening width Ds of the substrate-side lubricant inlet 63 is larger than the width of the first gap G1 and the width of the second gap G2 in the first main bearing 41. Therefore, air is more actively released from the substrate-side lubricant inlet 63 than from the first gap G1 and the second gap G2. As a result, the lubricant L flows smoothly into the storage portion 65. When the storage portion 65 is filled with the lubricant L, the lubricant L also flows into the substrate-side lubricant inlet 63 (see arrow Y2 in FIG. 1).

[0070] Here, the end plate side lubricant inlet hole 64 is arranged radially outward of the substrate side lubricant inlet hole 63. Therefore, the path from the end plate side lubricant inlet hole 64 to the substrate side lubricant inlet hole 63 is more complex than when the end plate side lubricant inlet hole 64 and the substrate side lubricant inlet hole 63 are arranged coaxially. As a result, the lubricant L is distributed evenly throughout the carrier 3.

[0071] <Operation of the reduction gear> Next, the operation of the reduction gear 1 will be described. In the reduction gear transmission 1, a portion of the external teeth 15d, 16d of each of the oscillating external gears 15, 16 meshes with the internal tooth pin 5 of the case 2. When the electric motor 101 is driven in this state, the rotation of the motor shaft 104 is transmitted to the input shaft 80 via the motor spur gear 105 and the input spur gear 82. This causes the input shaft 80 to rotate.

[0072] As the input shaft 80 rotates, the transmission spur gears 14 that mesh with the external teeth 80b of the input shaft 80 rotate. The crankshafts 13 rotate integrally with the transmission spur gears 14 about the second rotation axis A2. As a result, each of the oscillating external gears 15, 16 is oscillated and rotated. Here, the number of teeth of each of the external teeth 15d, 16d is, for example, one less than the number of the internal pins 5. Therefore, each of the oscillating external gears 15, 16 is rotated on its axis such that the meshing points of each of the external teeth 15d, 16d with respect to the internal pin 5 (case 2) are sequentially shifted in the circumferential direction. This rotation is decelerated relative to the rotation of the crankshaft 13.

[0073] As each of the oscillating external gears 15, 16 rotates, each of the crankshafts 13 also rotates about the second rotation axis A2 while revolving around the first rotation axis A1. Each of the crankshafts 13 is rotatably supported by the carrier 3 (base plate portion 7, end plate portion 8). Therefore, the carrier 3 rotates as each of the crankshafts 13 revolves. The interior of the reduction gear 1 (inside the case 2, inside the carrier 3) is filled with lubricant L, allowing the carrier 3 to rotate smoothly.

[0074] As the carrier 3 rotates, the reduction gear transmission 1 reduces the rotation of the electric motor 101 and outputs the reduced rotation to the driven member 102. This drives the driven member 102. If the driven member 102 were fixed, the reduction gear transmission 1 would be able to reduce the rotation of the electric motor 101 and output it from the case 2.

[0075] In this way, the carrier 3 in the above-described reduction gear transmission 1 is formed with the substrate-side lubricant inlet hole 63 and the end plate-side lubricant inlet hole 64, which communicate with the outside of the carrier 3 and the internal storage section 65. Therefore, the lubricant L can easily flow into the inside of the carrier 3 via the end plate-side lubricant inlet hole 64, for example. Moreover, the minimum opening width Ds of the substrate-side lubricant inlet hole 63 and the minimum opening width De of the end plate-side lubricant inlet hole 64 are larger than the widths of the first gap G1 and the second gap G2 in each of the main bearings 41, 42. Therefore, the lubricant L can be more actively injected, for example, from the end plate-side lubricant inlet hole 64 than from the first gap G1 or the second gap G2 in each of the main bearings 41, 42. This makes it possible to facilitate the work of improving the drive efficiency of the reduction gear transmission 1.

[0076] The end plate-side lubricant inlet hole 64 is exposed from the external mechanism part 86 when viewed in the axial direction. In this way, even in a reduction gear transmission 1 equipped with the external mechanism part 86, it is possible to prevent the external mechanism part 86 from interfering with the injection of the lubricant L into the substrate-side lubricant inlet hole 63. This allows the lubricant L to be injected more actively from the substrate-side lubricant inlet hole 63.

[0077] The base plate portion 7 and end plate portion 8 that constitute the carrier 3 are arranged opposite each other in the axial direction with the accommodation portion 65 in between. The base plate portion 7 and end plate portion 8 are formed with a substrate-side lubricant inlet hole 63 and an end plate-side lubricant inlet hole 64, respectively. Therefore, when the lubricant L is caused to flow into the accommodation portion 65 through the substrate-side lubricant inlet hole 63, the substrate-side lubricant inlet hole 63 can function as an air vent. By venting air through the substrate-side lubricant inlet hole 63, the lubricant L can flow smoothly into the accommodation portion 65.

[0078] The end plate-side lubricant inlet hole 64 is disposed radially outward of the substrate-side lubricant inlet hole 63. Therefore, the path from the end plate-side lubricant inlet hole 64 to the substrate-side lubricant inlet hole 63 can be made more complex than when the end plate-side lubricant inlet hole 64 and the substrate-side lubricant inlet hole 63 are disposed coaxially. As a result, the lubricant L can be distributed evenly throughout the carrier 3. There are three substrate-side lubricant inlet holes 63 and three end plate-side lubricant inlet holes 64. The substrate-side lubricant inlet holes 63 and the end plate-side lubricant inlet holes 64 are arranged at regular intervals in the circumferential direction around the first rotation axis A1. By using the multiple end plate-side lubricant inlet holes 64, the lubricant L can be made to flow into the storage section 65 quickly and smoothly.

[0079] The reduction gear 1 includes a housing 70 that covers the end plate 8. The housing 70, the case 2, and the end plate 8 form a lubricant reservoir 74. The end plate-side lubricant inlet hole 64 is connected to this lubricant reservoir 74. Therefore, by filling the lubricant reservoir 74 with lubricant L, the lubricant L can be injected into the storage portion 65 via the lubricant reservoir 74. This allows a sufficient amount of lubricant L for the reduction gear 1 to be retained, and also makes it easier to improve the drive efficiency of the reduction gear 1.

[0080] The end plate-side lubricant inlet holes 64 are arranged at regular intervals in the circumferential direction on the outer periphery of the end plate portion 8, radially inward of the second main bearing 42. That is, the end plate-side lubricant inlet holes 64 are arranged close to the internally toothed pins 5 of the case 2. As a result, the lubricant L flowing into the accommodating portion 65 can be filled into the accommodating portion 65 sequentially, starting from the vicinity of the internally toothed pins 5. For this reason, the lubricant L can be actively applied to the internally toothed pins 5 and the meshing portions of the external teeth 15d, 16d of the oscillating external gears 15, 16. This improves the drive efficiency of the reduction gear transmission 1.

[0081] The present invention is not limited to the above-described embodiment, and includes various modifications to the above-described embodiment without departing from the spirit of the present invention.

[0082] For example, in the above embodiment, a so-called eccentric oscillation type reduction gear transmission 1 has been described as a rotating device. However, the present invention is not limited to this, and the configuration of the reduction gear transmission 1 described above can be adopted in various rotating devices in which two rotating bodies (a first rotating body and a second rotating body) are provided so as to be rotatable relative to each other via rolling bearings.

[0083] In the above embodiment, the reduction mechanism 4 has been described as having two oscillating external gears 15, 16. The reduction mechanism 4 has been described as having three crankshafts 13. However, this is not limited to this, and the reduction mechanism 4 may have at least one oscillating external gear. The number of crankshafts 13 may also be plural.

[0084] In the above embodiment, the main bearings 41, 42 are so-called tapered roller bearings. However, this is not limitative, and various rolling bearings can be used as the main bearings 41, 42. In the above embodiment, the case 2, the base plate 7, and the end plate 8 are each formed from spheroidal graphite cast iron. For example, the case where FCD450 is used as the spheroidal graphite cast iron has been described. However, this is not limited to this, and various materials can be used for the case 2, the base plate 7, and the end plate 8.

[0085] In the above embodiment, the substrate-side lubricant inlet hole 63 and the end plate-side lubricant inlet hole 64 are formed in a uniform circular shape when viewed in the axial direction. However, this is not limiting, and the substrate-side lubricant inlet hole 63 and the end plate-side lubricant inlet hole 64 do not have to be circular when viewed in the axial direction.

[0086] For example, if the substrate side lubricant inlet hole 63 and the end plate side lubricant inlet hole 64 are elliptical when viewed from the axial direction, the minimum opening widths Ds, De of the substrate side lubricant inlet hole 63 and the end plate side lubricant inlet hole 64 are the lengths of the minor axes. The substrate-side lubricant inlet hole 63 and the end plate-side lubricant inlet hole 64 do not have to be uniformly formed. In this case, the minimum opening widths Ds and De of the substrate-side lubricant inlet hole 63 and the end plate-side lubricant inlet hole 64 are the minimum widths seen from the extending direction of the lubricant inlet hole 63, 64 at the locations where the opening cross-sectional areas of the lubricant inlet holes 63, 64 are smallest.

[0087] In the above embodiment, the case where, for example, three substrate-side lubricant inlet holes 63 and three end plate-side lubricant inlet holes 64 are formed has been described. The case where the substrate-side lubricant inlet holes 63 are arranged around the substrate shaft insertion hole 7d at regular intervals in the circumferential direction has been described. The case where the end plate-side lubricant inlet holes 64 are arranged on the outer periphery of the end plate portion 8, radially inward from the second main bearing 42, at regular intervals in the circumferential direction has been described. However, this is not a limitation, and the numbers and locations of the substrate-side lubricant inlet holes 63 and end plate-side lubricant inlet holes 64 can be determined as desired.

[0088] In the above embodiment, a case has been described in which the housing 70 is provided on the end plate 8 side of the reduction gear transmission 1 so as to cover this end plate 8. A case has been described in which the lubricant reservoir 74 formed by the housing 70 is utilized to allow the lubricant L to flow into the accommodating portion 65 through the end plate-side lubricant inlet hole 64. However, this is not limiting, and the housing 70 may not be provided.

[0089] In this case, the lubricant L may be injected directly from the end plate side lubricant inlet hole 64. It is also possible to inject the lubricant L directly from the substrate side lubricant inlet hole 63. When the lubricant L is injected directly from the substrate side lubricant inlet hole 63, the end plate side lubricant inlet hole 64 functions as an air vent when the lubricant L flows into the storage section 65. When the housing 70 is not provided, only one of the substrate-side lubricant inlet hole 63 and the end plate-side lubricant inlet hole 64 may be formed. Even in this configuration, the lubricant L can easily flow into the storage section 65 through the substrate-side lubricant inlet hole 63 or the end plate-side lubricant inlet hole 64.

[0090] Among the embodiments disclosed in this specification, those that are comprised of multiple objects may be integrated, and conversely, those that are comprised of a single object may be separated into multiple objects. Regardless of whether they are integrated, it is sufficient that they are configured to achieve the object of the invention. [Explanation of symbols]

[0091] 1...Reduction gear (rotating gear) 2...Case (first rotating body) 3...Carrier (second rotating body) 5...Internal tooth pin (mechanism, internal tooth gear) 7... Board portion (first wall portion, first carrier) 8...End plate portion (second wall portion, second carrier) 13...Crankshaft (mechanical part) 15...First oscillating external gear (mechanism, oscillating external gear) 16... Second oscillating external gear (mechanism, oscillating external gear) 41...First main bearing (rolling bearing) 42...Second main bearing (rolling bearing) 43...Outer Race 44...Inner race 45...Rolling element 50...Cage 63...substrate side lubricant inlet hole (hole portion, first hole portion) 64...End plate side lubricant inlet hole (hole portion, second hole portion) 65...Storage section 70…Housing 74...Lubricant reservoir (other storage area) 80...Input shaft (mechanical part) 80b...External teeth (other mechanism parts) 85...Internal mechanism section (mechanism section) 86...External mechanism (other mechanism) 105...Motor spur gear (other mechanism parts) A1...First rotation axis (rotation axis) Ds: Minimum opening width of lubricant inlet hole on the substrate side De: Minimum opening width of the lubricant inlet hole on the end plate G1...First gap G2: Second gap

Claims

1. a cylindrical first rotor; a pair of rolling bearings provided on the first rotor and arranged on both sides of the first rotor in the axial direction; a second rotor disposed radially inside the first rotor and supported by the first rotor via the rolling bearing so as to be rotatable about a rotation axis; a mechanical portion disposed radially inside the second rotor; Equipped with a housing portion configured between the first rotating body and the second rotating body and housing the mechanical portion; a hole portion disposed in the second rotor and communicating with an outside of the second rotor and the accommodation portion; and The rolling bearing is an outer race disposed on the first rotating body side; an inner race disposed on the second rotating body side; a plurality of rolling elements disposed between the outer race and the inner race; a cage disposed between the outer race and the inner race and configured to hold the plurality of rolling elements; and a minimum opening width of the opening widths perpendicular to the extending direction of the hole portion is larger than a width between the outer race and the cage and a width between the inner race and the cage; Rotating device.

2. another mechanism portion provided outside the second rotating body and transmitting power to the mechanism portion; The hole is provided at a position exposed from the other mechanism when viewed from the axial direction. The rotating device according to claim 1 .

3. the second rotating body has a first wall portion and a second wall portion that face each other on both sides in the axial direction with the accommodation portion interposed therebetween, The hole portion is a first hole provided in the first wall portion; a second hole provided in the second wall portion; having The rotating device according to claim 1 or 2.

4. The first hole portion is disposed radially inward of the second hole portion. The rotating device according to claim 3 .

5. a plurality of the first holes and a plurality of the second holes; The first hole portion and the second hole portion are respectively arranged side by side in a circumferential direction around the rotation axis. The rotating device according to claim 4.

6. a housing that covers the second rotating body, another storage section defined by the housing and the second rotating body; the other mechanism unit is accommodated in the other accommodation unit, The hole communicates with the other storage portion. The rotating device according to claim 2 .

7. the first rotor has internal teeth on its inner circumferential surface, the second rotor has a first carrier and a second carrier that face each other in the axial direction, The mechanism unit includes: a crankshaft rotatably supported by the first carrier and the second carrier; an oscillating external gear that is accommodated in the accommodation portion and rotatably supported by the crankshaft and that meshes with the internal teeth; Including, The hole is disposed adjacent to the internal tooth. The rotating device according to claim 1 .

8. The hole portion is a first hole provided in the first carrier; a second hole portion provided in the second carrier; and The first hole portion is disposed radially inward of the second hole portion. The rotating device according to claim 7.

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