speed reducer

Abstract

To improve the stiffness and an attenuation property of a speed reducer.SOLUTION: A speed reducer has a case 210 with an outer diameter D having an inner teeth 212, a plurality of crank shafts 410 coaxially with a center axis F0 of the case, separated only by a diameter D2, separated from each other in a circumferential direction, and having an outer tooth 430, a plurality of outer members 300 having an outer tooth engaged with the inner tooth of the case and eccentrically moved by the crank shaft, and a carrier 220 rotatably supporting the crank shafts and rotated with respect to the case by the crank shafts. The crank shaft has an eccentric body with a diameter dc1, crank journals 411 and 412 with a diameter dc2, rollers 433 and 434 of diametrical dimensions dr1 in which n1 is disposed around an eccentric body, and rollers 431 and 432 of diametrical dimensions dr2 in which n2 is disposed around the crank journals. The expression 5.5≤D / dc1≤7.0 is established.SELECTED DRAWING: Figure 1

Description

Technical Field

[0005] , circle , , ,

[0004] , , , It is positioned and rotates around a crank axis parallel to the central axis of the case. , , , , , , , , 1 , , condition , , , , On the circle ,

[0006] , A mounting flange with an outer diameter D is provided around the outer circumference of the aforementioned case, ,

[0001] The present invention relates to a technology suitable for use in a speed reducer.

Background Art

[0002] In Patent Document 1, a speed reduction device is disclosed that includes an external gear, an internal gear that meshes internally with the external gear, a casing in which the internal gear is provided, and a carrier that rotates relative to the casing.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] There is a demand to provide a speed reducer with high torsional rigidity and high damping performance. Conventionally, a tapered bearing has been used for the crank journal part, so it has been impossible to increase the diameter of the crank journal part and the high filling ratio, and it has been difficult to increase the rigidity and damping of the speed reducer.

[0005] The present invention has been made in view of the above circumstances, and aims to achieve the object of increasing the rigidity and damping of the speed reducer.

Means for Solving the Problems

[0006] The speed reducer according to one aspect of the present invention is circle cylinder <![CDATA[ condition ]]in can be a case having an internal tooth with an outer diameter D 1 and, A mounting flange with an outer diameter D is provided around the outer circumference of the aforementioned case, concentric with the central axis of the case and having a diameter D2 On the circle spaced apart from each other in the circumferential direction at It is positioned and rotates around a crank axis parallel to the central axis of the case.Multiple crankshafts having external teeth, A plurality of external tooth members having external teeth that mesh with the internal teeth of the case and which move eccentrically by the crankshaft, A carrier that rotatably supports the crankshaft and rotates relative to the case by the crankshaft, It has, The aforementioned crankshaft An eccentric body with diameter dc1, A crank journal with a diameter of dc2, n1 is arranged around the aforementioned eccentric body with a diameter of dr1 Needle bearing Koro and, The aforementioned crank journal has n2 rods arranged around it with a diameter of dr2. Needle bearing Koro and, It has, The aforementioned Mounting flange The diameter D and the diameter dc1 of the eccentric body are 5.5 ≤ D / dc1 ≤ 7.0 Set to the range, The aforementioned case The outer diameter D1 and the diameter dc1 of the eccentric body are 4.5 ≤ D1 / dc1 ≤ 6.0 Set to the range, The aforementioned case Concentric with the central axis The aforementioned crankshaft Circles on which lines are placed The diameter D2 and the diameter dc1 of the eccentric body are 2.0 ≤ D2 / dc1 ≤ 3.0 Set to the range, The diameter dc1 of the eccentric body and the diameter dimension dr1 of the roller are, 6.0 ≤ dc1 / dr1 ≤ 9.0 Set to the range, The aforementioned Mounting flange The diameter D and the diameter dc2 of the crank journal are 6.0 ≤ D / dc² ≤ 7.5 Set to the range, The aforementioned case The outer diameter D1 and the diameter dc2 of the crank journal 5.0 ≤ D1 / dc2 ≤ 6.5 Set to the range, before Record Direct Set the diameter D2 and the diameter dc2 of the crank journal to 2.5 ≤ D2 / dc2 ≤ 3.5 within the range of Set the diameter dc2 of the crank journal and the diameter dimension dr2 of the roller to 6.0 ≤ dc2 / dr2 ≤ 9.0 within the range of Set the diameter dc2 of the crank journal and the diameter dc1 of the eccentric body to 0.85 ≤ dc2 / dc1 ≤ 1.0 within the range of Set the diameter dc1 of the eccentric body, the diameter dr1 of the roller, and the number n1 of rollers to 0.7 ≤ n1·dr1 / π(dc1 + dr1) ≤ 0.9 within the range of Set the number n1 of rollers to 15.3 ≤ n1 ≤ 28.3 within the range of Set the diameter dc2 of the crank journal, the diameter dr2 of the roller, and the number n2 of rollers to 0.7 ≤ n2·dr2 / π(dc2 + dr2) ≤ 0.9 within the range of Set the number n2 of rollers to 15.3 ≤ n2 ≤ 28.3 within the range of Determine to be provided The speed reducer according to one aspect of the present invention includes a case having an outer diameter D with internal teeth, a plurality of crank shafts that are concentric with the central axis of the case, separated by a diameter D2, and spaced apart from each other in the circumferential direction and have external teeth, a plurality of external tooth members that have external teeth meshing with the internal teeth of the case and perform eccentric motion by the crank shafts, a carrier that rotatably supports the crank shafts and rotates with respect to the case by the crank shafts, and has The crank shaft has an eccentric body with a diameter dc1, a crank journal with a diameter dc2, A roller with diameter dr1 is arranged around the aforementioned eccentric body, n1 of which are n1. Two rollers with diameter dr2 are arranged around the crank journal, Having 、 5.5 ≤ D / dc1 ≤ 7.0 dea ru.

[0007] According to one aspect of the present invention, when viewed in the axial direction of the case, the cross-sectional area of ​​the crank eccentric body is increased relative to the cross-sectional area of ​​the case, that is, the crankshaft is made thicker as a balance for the reduction gear, thereby increasing the number of rollers arranged around the eccentric body. This increases the number of rollers (needles) that come into contact with the eccentric body, reduces the load applied to each roller, and improves the damping performance of the reduction gear. Furthermore, by reducing the variation in the load applied to multiple rollers and simultaneously making the crankshaft thicker, rigidity can be improved. In other words, this gearbox improves rigidity and damping characteristics by increasing the number of physical contacts through a thicker crankshaft and the placement of numerous small-diameter rollers in the bearings.

[0008] A gearbox according to one aspect of the present invention comprises a cylindrical case having an outer diameter D1 and internal teeth, and a plurality of crankshafts having external teeth, which are concentric with the central axis of the case, spaced apart by a diameter D2, and spaced apart from each other in the circumferential direction. A plurality of external tooth members having external teeth that mesh with the internal teeth of the case and which move eccentrically by the crankshaft, A carrier that rotatably supports the crankshaft and rotates relative to the case by the crankshaft, It has, The aforementioned crankshaft An eccentric body with diameter dc1, A crank journal with a diameter of dc2, A roller with diameter dr1 is arranged around the aforementioned eccentric body, n1 of which are n1. Two rollers with diameter dr2 are arranged around the crank journal, It has, Outer diameter D1 of the aforementioned case and, The diameter dc1 of the eccentric body Relationship of, 4.5 ≤ D1 / dc1 ≤ 6.0 By setting the roller diameter dr1 to a certain range, the number of rollers n1 is increased, thereby increasing the number of contacts between the rollers and the eccentric body, and reducing the unevenness in the load that each roller receives from the eccentric part. tosu ru.

[0009] According to one aspect of the present invention, when viewed in the axial direction of the case, the cross-sectional area of ​​the crank eccentric body is increased relative to the cross-sectional area of ​​the case, that is, the crankshaft is made thicker as a balance for the reduction gear, thereby increasing the number of rollers arranged around the eccentric body. At the same time, by setting the thickness of the rollers within an appropriate range, the number of rollers (needles) in contact with the eccentric body is increased, and the load applied to each roller is reduced, thereby improving the damping performance of the reduction gear. Furthermore, by reducing the variation in the load applied to multiple rollers and simultaneously making the crankshaft thicker, rigidity can be improved. In other words, this gearbox improves rigidity and damping characteristics by increasing the number of physical contacts through a thicker crankshaft and the placement of numerous small-diameter rollers in the bearings.

[0010] A gearbox according to one aspect of the present invention comprises a case with an outer diameter D having internal teeth, Multiple crankshafts having external teeth are concentric with the central axis of the aforementioned case, spaced apart by a diameter D2, and spaced apart from each other in the circumferential direction, A plurality of external tooth members having external teeth that mesh with the internal teeth of the case and which move eccentrically by the crankshaft, A carrier that rotatably supports the crankshaft and rotates relative to the case by the crankshaft, It has, The aforementioned crankshaft An eccentric body with diameter dc1, A crank journal with a diameter of dc2, A roller with diameter dr1 is arranged around the aforementioned eccentric body, n1 of which are n1. Two rollers with diameter dr2 are arranged around the crank journal, It has, For the aforementioned case The distance between the crankshafts Diameter D2 and, The diameter dc1 of the eccentric body Relationship of, 2.0 ≤ D2 / dc1 ≤ 3.0 By setting the range, the diameter dimension dr1 of the roller is reduced, and the number of rollers n1 is increased, thereby increasing the number of contacts between the roller and the eccentric body, and reducing the unevenness in the load that each roller receives from the eccentric part. .

[0011] According to one aspect of the present invention, when viewed in the axial direction of the case, the cross-sectional area of ​​the crank eccentric body is made larger than the cross-sectional area of ​​the case, and the crankshaft is positioned away from the central axis of the reduction gear. In other words, by making the crankshaft thicker and positioning it outward as a balance for the reduction gear, the number of rollers arranged around the eccentric body can be increased. At the same time, by setting the thickness of the rollers within an appropriate range, the number of rollers (needles) in contact with the eccentric body can be increased, and the load applied to each roller can be reduced, thereby improving the damping performance of the reduction gear. Furthermore, by reducing the variation in the load applied to multiple rollers and simultaneously making the crankshaft thicker, rigidity can be improved. In other words, this gearbox improves rigidity and damping characteristics by increasing the number of physical contacts through a thicker crankshaft and the placement of numerous small-diameter rollers in the bearings.

[0012] A gearbox according to one aspect of the present invention comprises a case with an outer diameter D having internal teeth, Multiple crankshafts having external teeth are concentric with the central axis of the aforementioned case, spaced apart by a diameter D2, and spaced apart from each other in the circumferential direction, A plurality of external tooth members having external teeth that mesh with the internal teeth of the case and which move eccentrically by the crankshaft, A carrier that rotatably supports the crankshaft and rotates relative to the case by the crankshaft, It has, The aforementioned crankshaft An eccentric body with diameter dc1, A crank journal with a diameter of dc2, A roller with diameter dr1 is arranged around the aforementioned eccentric body, n1 of which are n1. Two rollers with diameter dr2 are arranged around the crank journal, It has, The diameter dc1 of the eccentric body and, The diameter dimension of the aforementioned roller dr1 Relationship of, 6.0 ≤ dc1 / dr1 ≤ 9.0 By setting the range and increasing the number of rollers n1, the number of contacts between the rollers and the eccentric body is increased, thereby reducing the unevenness in the load that each roller receives from the eccentric part. ru.

[0013] According to one aspect of the present invention, when viewed in the axial direction of the case, the cross-sectional area of ​​the crank eccentric body is increased relative to the cross-sectional area of ​​the case, that is, the crankshaft is made thicker as a balance for the reduction gear, thereby increasing the number of rollers arranged around the eccentric body. At the same time, by setting the thickness of the rollers within an appropriate range, the number of rollers (needles) in contact with the eccentric body is increased, and the load applied to each roller is reduced, thereby improving the damping performance of the reduction gear. Furthermore, by reducing the variation in the load applied to multiple rollers and simultaneously making the crankshaft thicker, rigidity can be improved. In other words, this gearbox improves rigidity and damping characteristics by increasing the number of physical contacts through a thicker crankshaft and the placement of numerous small-diameter rollers in the bearings.

[0014] A gearbox according to one aspect of the present invention comprises a case with an outer diameter D having internal teeth, Multiple crankshafts having external teeth are concentric with the central axis of the aforementioned case, spaced apart by a diameter D2, and spaced apart from each other in the circumferential direction, A plurality of external tooth members having external teeth that mesh with the internal teeth of the case and which move eccentrically by the crankshaft, A carrier that rotatably supports the crankshaft and rotates relative to the case by the crankshaft, It has, The aforementioned crankshaft An eccentric body with diameter dc1, A crank journal with a diameter of dc2, A roller with diameter dr1 is arranged around the aforementioned eccentric body, n1 of which are n1. Two rollers with diameter dr2 are arranged around the crank journal, It has, The outermost diameter D of the aforementioned case and , the diameter dc2 of the crank journal Relationship of, 6.0 ≤ D / dc² ≤ 7.5 By setting the roller diameter dr2 to a certain range, the number of rollers n2 is increased, the number of contacts between the rollers and the crank journal is increased, and the unevenness in the load that each roller receives from the crank journal is reduced. ru.

[0015] According to one aspect of the present invention, by increasing the cross-sectional area of ​​the crank journal relative to the cross-sectional area of ​​the case when viewed in the axial direction of the case, that is, by making the crankshaft thicker as a balance for the reduction gear, the number of rollers arranged around the crank journal can be increased. At the same time, by setting the thickness of the rollers within an appropriate range, the number of rollers (needles) in contact with the crank journal can be increased, and the load applied to each roller can be reduced, thereby improving the damping performance of the reduction gear. Furthermore, by reducing the variation in the load applied to multiple rollers and simultaneously making the crankshaft thicker, rigidity can be improved. In other words, this gearbox improves rigidity and damping characteristics by increasing the number of physical contacts through a thicker crankshaft and the placement of numerous small-diameter rollers in the bearings.

[0016] A gearbox according to one aspect of the present invention comprises a cylindrical case having an outer diameter D1 and internal teeth, and a plurality of crankshafts having external teeth, which are concentric with the central axis of the case, spaced apart by a diameter D2, and spaced apart from each other in the circumferential direction. A plurality of external tooth members having external teeth that mesh with the internal teeth of the case and which move eccentrically by the crankshaft, A carrier that rotatably supports the crankshaft and rotates relative to the case by the crankshaft, It has, The aforementioned crankshaft An eccentric body with diameter dc1, A crank journal with a diameter of dc2, A roller with diameter dr1 is arranged around the aforementioned eccentric body, n1 of which are n1. Two rollers with diameter dr2 are arranged around the crank journal, It has, Outer diameter D1 of the aforementioned case and , the diameter dc2 of the crank journal Relationship of 5.0 ≤ D1 / dc2 ≤ 6.5 By setting the roller diameter dr2 to a certain range, the number of rollers n2 is increased, the number of contacts between the rollers and the crank journal is increased, and the unevenness in the load that each roller receives from the crank journal is reduced. ru.

[0017] According to one aspect of the present invention, by increasing the cross-sectional area of ​​the crank journal relative to the cross-sectional area of ​​the case when viewed in the axial direction of the case, that is, by making the crankshaft thicker as a balance for the reduction gear, the number of rollers arranged around the crank journal can be increased. At the same time, by setting the thickness of the rollers within an appropriate range, the number of rollers (needles) in contact with the crank journal can be increased, and the load applied to each roller can be reduced, thereby improving the damping performance of the reduction gear. Furthermore, by reducing the variation in the load applied to multiple rollers and simultaneously making the crankshaft thicker, rigidity can be improved. In other words, this gearbox improves rigidity and damping characteristics by increasing the number of physical contacts through a thicker crankshaft and the placement of numerous small-diameter rollers in the bearings.

[0018] A gearbox according to one aspect of the present invention comprises a case with an outer diameter D having internal teeth, Multiple crankshafts having external teeth are concentric with the central axis of the aforementioned case, spaced apart by a diameter D2, and spaced apart from each other in the circumferential direction, A plurality of external tooth members having external teeth that mesh with the internal teeth of the case and which move eccentrically by the crankshaft, A carrier that rotatably supports the crankshaft and rotates relative to the case by the crankshaft, It has, The aforementioned crankshaft An eccentric body with diameter dc1, A crank journal with a diameter of dc2, A roller with diameter dr1 is arranged around the aforementioned eccentric body, n1 of which are n1. Two rollers with diameter dr2 are arranged around the crank journal, It has, Diameter D2 and , the diameter dc2 of the crank journal Relationship of, 2.5 ≤ D2 / dc2 ≤ 3.5 By setting the roller diameter dr2 to a certain range, the number of rollers n2 is increased, the number of contacts between the rollers and the crank journal is increased, and the unevenness in the load that each roller receives from the crank journal is reduced. ru.

[0019] According to one aspect of the present invention, when viewed in the axial direction of the case, the cross-sectional area of ​​the crank journal is made larger than the cross-sectional area of ​​the case, and the crankshaft is positioned away from the central axis of the reduction gear. In other words, by making the crankshaft thicker and positioning it outward as a balance for the reduction gear, the number of rollers arranged around the crank journal can be increased. At the same time, by setting the thickness of the rollers within an appropriate range, the number of rollers (needles) in contact with the crank journal can be increased, and the load applied to a single roller can be reduced, thereby improving the damping performance of the reduction gear. Furthermore, by reducing the variation in the load applied to multiple rollers and simultaneously making the crankshaft thicker, rigidity can be improved. In other words, this gearbox improves rigidity and damping characteristics by increasing the number of physical contacts through a thicker crankshaft and the placement of numerous small-diameter rollers in the bearings.

[0020] A gearbox according to one aspect of the present invention comprises a case with an outer diameter D having internal teeth, Multiple crankshafts having external teeth are concentric with the central axis of the aforementioned case, spaced apart by a diameter D2, and spaced apart from each other in the circumferential direction, A plurality of external tooth members having external teeth that mesh with the internal teeth of the case and which move eccentrically by the crankshaft, A carrier that rotatably supports the crankshaft and rotates relative to the case by the crankshaft, It has, The aforementioned crankshaft An eccentric body with diameter dc1, A crank journal with a diameter of dc2, A roller with diameter dr1 is arranged around the aforementioned eccentric body, n1 of which are n1. Two rollers with diameter dr2 are arranged around the crank journal, It has, The diameter of the crank journal dc2 and , the diameter dimension of the roller dr2 Relationship of, 6.0 ≤ dc² / dr² ≤ 9.0 By setting the range and increasing the number of rollers n2, the number of contacts between the rollers and the crank journal is increased, thereby reducing the unevenness in the load that each roller receives from the crank journal. ru.

[0021] According to one aspect of the present invention, by increasing the cross-sectional area of ​​the crank journal relative to the cross-sectional area of ​​the case when viewed in the axial direction of the case, that is, by making the crankshaft thicker as a balance for the reduction gear, the number of rollers arranged around the crank journal can be increased. At the same time, by setting the thickness of the rollers within an appropriate range, the number of rollers (needles) in contact with the crank journal can be increased, and the load applied to each roller can be reduced, thereby improving the damping performance of the reduction gear. Furthermore, by reducing the variation in the load applied to multiple rollers and simultaneously making the crankshaft thicker, rigidity can be improved. In other words, this gearbox improves rigidity and damping characteristics by increasing the number of physical contacts through a thicker crankshaft and the placement of numerous small-diameter rollers in the bearings.

[0022] A gearbox according to one aspect of the present invention comprises a case with an outer diameter D having internal teeth, Multiple crankshafts having external teeth are concentric with the central axis of the aforementioned case, spaced apart by a diameter D2, and spaced apart from each other in the circumferential direction, A plurality of external tooth members having external teeth that mesh with the internal teeth of the case and which move eccentrically by the crankshaft, A carrier that rotatably supports the crankshaft and rotates relative to the case by the crankshaft, It has, The aforementioned crankshaft An eccentric body with diameter dc1, A crank journal with a diameter of dc2, A roller with diameter dr1 is arranged around the aforementioned eccentric body, n1 of which are n1. Two rollers with diameter dr2 are arranged around the crank journal, It has, The diameter dc2 of the crank journal and the diameter dc1 of the eccentric body Relationship of, 0.85 ≤ dc² / dc¹ ≤ 1.0 By setting the number of rollers n1 and n2 within a certain range, the load balance on the crankshaft is optimized so that the rigidity of the rollers and the carrier does not decrease. .

[0023] According to one aspect of the present invention, by increasing the cross-sectional area of ​​the crank eccentric body and the crank journal relative to the cross-sectional area of ​​the case, that is, by making the crankshaft thicker as a balance for the reduction gear, the number of rollers arranged around the eccentric body and the crank journal can be increased. At the same time, by setting the thickness of the rollers within an appropriate range, the number of contact points between the rollers (needles) on the eccentric body and the crank journal can be increased, and the load applied to a single roller can be reduced, thereby improving the damping performance of the reduction gear. Furthermore, by reducing the variation in the load applied to multiple rollers and simultaneously making the crankshaft thicker, rigidity can be improved. In addition, by setting the thickness of the eccentric body, crank journal, and rollers within an appropriate range, the damping characteristics can be improved. In other words, this gearbox improves rigidity and damping characteristics by increasing the number of physical contacts through a thicker crankshaft and the placement of numerous small-diameter rollers in the bearings.

[0024] A gearbox according to one aspect of the present invention comprises a case with an outer diameter D having internal teeth, Multiple crankshafts having external teeth are concentric with the central axis of the aforementioned case, spaced apart by a diameter D2, and spaced apart from each other in the circumferential direction, A plurality of external tooth members having external teeth that mesh with the internal teeth of the case and which move eccentrically by the crankshaft, A carrier that rotatably supports the crankshaft and rotates relative to the case by the crankshaft, It has, The aforementioned crankshaft An eccentric body with diameter dc1, A crank journal with a diameter of dc2, A roller with diameter dr1 is arranged around the aforementioned eccentric body, n1 of which are n1. Two rollers with diameter dr2 are arranged around the crank journal, It has, before The diameter dc1 of the eccentric body and the diameter dr1 of the roller and number n1 and Relationship of 、 0.7≦ n1·dr1 / π(dc1+dr1) ≦0.9 By setting the range to increase the number of rollers n1 and setting the occupancy rate of the rollers on the eccentric body, the number of contacts between the rollers and the eccentric body is increased, thereby reducing the unevenness in the load that each roller receives from the eccentric body. ru.

[0025] According to one aspect of the present invention, by increasing the cross-sectional area of ​​the crank eccentric body relative to the cross-sectional area of ​​the case, that is, by making the crankshaft thicker as a balance for the reduction gear, the number of rollers arranged around the eccentric body can be increased. At the same time, by setting the thickness and number of rollers within an appropriate range, the number of rollers (needles) in contact with the eccentric body can be increased, and the load applied to each roller can be reduced, thereby improving the damping performance of the reduction gear. Furthermore, by reducing the variation in the load applied to multiple rollers and simultaneously making the crankshaft thicker, rigidity can be improved. In other words, this gearbox improves rigidity and damping characteristics by increasing the number of physical contacts through a thicker crankshaft and the placement of numerous small-diameter rollers in the bearings.

[0026] A gearbox according to one aspect of the present invention comprises a case with an outer diameter D having internal teeth, Multiple crankshafts having external teeth are concentric with the central axis of the aforementioned case, spaced apart by a diameter D2, and spaced apart from each other in the circumferential direction, A plurality of external tooth members having external teeth that mesh with the internal teeth of the case and which move eccentrically by the crankshaft, A carrier that rotatably supports the crankshaft and rotates relative to the case by the crankshaft, It has, The aforementioned crankshaft An eccentric body with diameter dc1, A crank journal with a diameter of dc2, A roller with diameter dr1 is arranged around the aforementioned eccentric body, n1 of which are n1. Two rollers with diameter dr2 are arranged around the crank journal, It has, before The number of notes n1 is 15.3 ≤ n1 ≤ 28.3 By setting it within this range, the number of contacts between the roller and the eccentric body is increased, and the unevenness in the load that each roller receives from the eccentric body is reduced. ru.

[0027] According to one aspect of the present invention, by setting the number of rollers arranged around the eccentric body of the crank to an appropriate range, the number of rollers (needles) in contact with the eccentric body is increased, and the load applied to a single roller is reduced, thereby improving the damping performance of the reduction gear. Furthermore, by reducing the variation in the load applied to multiple rollers and simultaneously increasing the thickness of the crankshaft, rigidity can be improved. In other words, this gearbox improves rigidity and damping characteristics by increasing the number of physical contacts through a thicker crankshaft and the placement of numerous small-diameter rollers in the bearings.

[0028] A gearbox according to one aspect of the present invention comprises a case with an outer diameter D having internal teeth, Multiple crankshafts having external teeth are concentric with the central axis of the aforementioned case, spaced apart by a diameter D2, and spaced apart from each other in the circumferential direction, A plurality of external tooth members having external teeth that mesh with the internal teeth of the case and which move eccentrically by the crankshaft, A carrier that rotatably supports the crankshaft and rotates relative to the case by the crankshaft, It has, The aforementioned crankshaft An eccentric body with diameter dc1, A crank journal with a diameter of dc2, A roller with diameter dr1 is arranged around the aforementioned eccentric body, n1 of which are n1. Two rollers with diameter dr2 are arranged around the crank journal, It has, before The diameter dc2 of the crank journal and the diameter dr2 of the roller and Number of rollers n2 Relationship , 0.7≦ n2·dr2 / π(dc2+dr2) ≦0.9 By setting it within this range, the number of contacts between the roller and the crank journal is increased, and the unevenness in the load that each roller receives from the crank journal is reduced. ru.

[0029] According to one aspect of the present invention, by increasing the cross-sectional area of ​​the crank journal relative to the cross-sectional area of ​​the case, that is, by making the crankshaft thicker as a balance for the reduction gear, the number of rollers arranged around the crank journal can be increased. At the same time, by setting the thickness of the rollers within an appropriate range, the number of rollers (needles) in contact with the crank journal can be increased, and the load applied to each roller can be reduced, thereby improving the damping performance of the reduction gear. Furthermore, by reducing the variation in the load applied to multiple rollers and simultaneously making the crankshaft thicker, rigidity can be improved. In other words, this gearbox improves rigidity and damping characteristics by increasing the number of physical contacts through a thicker crankshaft and the placement of numerous small-diameter rollers in the bearings.

[0030] A gearbox according to one aspect of the present invention comprises a case with an outer diameter D having internal teeth, Multiple crankshafts having external teeth are concentric with the central axis of the aforementioned case, spaced apart by a diameter D2, and spaced apart from each other in the circumferential direction, A plurality of external tooth members having external teeth that mesh with the internal teeth of the case and which move eccentrically by the crankshaft, A carrier that rotatably supports the crankshaft and rotates relative to the case by the crankshaft, It has, The aforementioned crankshaft An eccentric body with diameter dc1, A crank journal with a diameter of dc2, A roller with diameter dr1 is arranged around the aforementioned eccentric body, n1 of which are n1. Two rollers with diameter dr2 are arranged around the crank journal, It has, before Number of records n2 of , 15.3 ≤ n² ≤ 28.3 By setting it within this range, the number of contacts between the roller and the crank journal is increased, and the unevenness in the load that each roller receives from the crank journal is reduced. ru.

[0031] According to one aspect of the present invention, by setting the number of rollers arranged around the crank journal to an appropriate range, the number of rollers (needles) in contact with the crank journal is increased, and the load applied to a single roller is reduced, thereby improving the damping performance of the reduction gear. Furthermore, by reducing the variation in the load applied to multiple rollers and simultaneously increasing the thickness of the crankshaft, rigidity can be improved. In other words, this gearbox improves rigidity and damping characteristics by increasing the number of physical contacts through a thicker crankshaft and the placement of numerous small-diameter rollers in the bearings.

[0032] A gearbox according to one aspect of the present invention comprises a case with an outer diameter D having internal teeth, A crankshaft having an eccentric body with a diameter dc1 that is spaced by a diameter D2 from the central axis of the aforementioned case, It has, The crankshaft is made thicker relative to the outermost diameter D of the case, and the diameter dc1 of the eccentric body is increased. like, 5.5 ≤ D / dc1 ≤ 7.0 Let's assume that.

[0033] According to one aspect of the present invention, when viewed in the axial direction of the case, the cross-sectional area of ​​the crank eccentric body is increased relative to the cross-sectional area of ​​the case, that is, the crankshaft is made thicker as a balance for the reduction gear, thereby increasing the number of rollers arranged around the eccentric body. This increases the number of rollers (needles) that come into contact with the eccentric body, reduces the load applied to each roller, and improves the damping performance of the reduction gear. Furthermore, by reducing the variation in the load applied to multiple rollers and simultaneously making the crankshaft thicker, rigidity can be improved. In other words, this gearbox improves rigidity and damping characteristics by increasing the number of physical contacts through a thicker crankshaft and the placement of numerous small-diameter rollers in the bearings.

[0034] A gearbox according to one aspect of the present invention comprises a cylindrical case having an outer diameter D1 and internal teeth, and a crankshaft having an eccentric body and a crank journal with a diameter dc2, spaced a distance D2 from the central axis of the case, It has, The crankshaft is made thicker relative to the outer diameter D1 of the case, and the diameter dc1 of the eccentric body is increased. like , 4.5 ≤ D1 / dc1 ≤ 6.0 Let's assume that.

[0035] According to one aspect of the present invention, when viewed in the axial direction of the case, the cross-sectional area of ​​the crank eccentric body is increased relative to the cross-sectional area of ​​the case, that is, the crankshaft is made thicker as a balance for the reduction gear, thereby increasing the number of rollers arranged around the eccentric body. At the same time, by setting the thickness of the rollers within an appropriate range, the number of rollers (needles) in contact with the eccentric body is increased, and the load applied to each roller is reduced, thereby improving the damping performance of the reduction gear. Furthermore, by reducing the variation in the load applied to multiple rollers and simultaneously making the crankshaft thicker, rigidity can be improved. In other words, this gearbox improves rigidity and damping characteristics by increasing the number of physical contacts through a thicker crankshaft and the placement of numerous small-diameter rollers in the bearings.

[0036] A gearbox according to one aspect of the present invention comprises a case with an outer diameter D having internal teeth, A crankshaft having an eccentric body with a diameter dc1 that is spaced by a diameter D2 from the central axis of the aforementioned case, It has, The crankshaft, which is spaced apart from the case by a diameter D2, is made thicker, and the diameter dc1 of the eccentric body is increased. like , 2.0 ≤ D2 / dc1 ≤ 3.0 Let's assume that.

[0037] According to one aspect of the present invention, when viewed in the axial direction of the case, the cross-sectional area of ​​the crank eccentric body is made larger than the cross-sectional area of ​​the case, and the crankshaft is positioned away from the central axis of the reduction gear. In other words, by making the crankshaft thicker and positioning it outward as a balance for the reduction gear, the number of rollers arranged around the eccentric body can be increased. At the same time, by setting the thickness of the rollers within an appropriate range, the number of rollers (needles) in contact with the eccentric body can be increased, and the load applied to each roller can be reduced, thereby improving the damping performance of the reduction gear. Furthermore, by reducing the variation in the load applied to multiple rollers and simultaneously making the crankshaft thicker, rigidity can be improved. In other words, this gearbox improves rigidity and damping characteristics by increasing the number of physical contacts through a thicker crankshaft and the placement of numerous small-diameter rollers in the bearings.

[0038] A gear reducer according to one aspect of the present invention comprises a case having internal teeth, A crankshaft that is spaced by a diameter D2 from the central axis of the aforementioned case, It has, The aforementioned crankshaft An eccentric body with diameter dc1, The rollers with diameter dr1 are arranged around the eccentric body, Equipped with The crankshaft, which is spaced apart from the case by a diameter D2, is made thicker, and the diameter dc1 of the eccentric body and the diameter dimension dr1 of the roller are set, and the roller and the eccentric body Increase the number of contacts like , 6.0 ≤ dc1 / dr1 ≤ 9.0 Let's assume that.

[0039] According to one aspect of the present invention, when viewed in the axial direction of the case, the cross-sectional area of ​​the crank eccentric body is increased relative to the cross-sectional area of ​​the case, that is, the crankshaft is made thicker as a balance for the reduction gear, thereby increasing the number of rollers arranged around the eccentric body. At the same time, by setting the thickness of the rollers within an appropriate range, the number of rollers (needles) in contact with the eccentric body is increased, and the load applied to each roller is reduced, thereby improving the damping performance of the reduction gear. Furthermore, by reducing the variation in the load applied to multiple rollers and simultaneously making the crankshaft thicker, rigidity can be improved. In other words, this gearbox improves rigidity and damping characteristics by increasing the number of physical contacts through a thicker crankshaft and the placement of numerous small-diameter rollers in the bearings.

[0040] A gearbox according to one aspect of the present invention comprises a case with an outer diameter D having internal teeth, A crankshaft that is spaced by a diameter D2 from the central axis of the aforementioned case, It has, The aforementioned crankshaft A crank journal with a diameter of dc2, Two rollers with diameter dr2 are arranged around the crank journal, Equipped with, By increasing the diameter of the crankshaft relative to the outermost diameter D of the case, increasing the diameter dc2 of the crank journal, and decreasing the diameter dr2 of the rollers, the number of rollers n2 is increased, thereby increasing the number of contacts between the rollers and the crank journal. like , 6.0 ≤ D / dc² ≤ 7.5 Let's assume that.

[0041] According to one aspect of the present invention, by increasing the cross-sectional area of ​​the crank journal relative to the cross-sectional area of ​​the case when viewed in the axial direction of the case, that is, by making the crankshaft thicker as a balance for the reduction gear, the number of rollers arranged around the crank journal can be increased. At the same time, by setting the thickness of the rollers within an appropriate range, the number of rollers (needles) in contact with the crank journal can be increased, and the load applied to each roller can be reduced, thereby improving the damping performance of the reduction gear. Furthermore, by reducing the variation in the load applied to multiple rollers and simultaneously making the crankshaft thicker, rigidity can be improved. In other words, this gearbox improves rigidity and damping characteristics by increasing the number of physical contacts through a thicker crankshaft and the placement of numerous small-diameter rollers in the bearings.

[0042] A gearbox according to one aspect of the present invention comprises a cylindrical case having an outer diameter D1 and internal teeth, and a crankshaft having a crank journal with a diameter dc2 and spaced by a diameter D2 from the central axis of the case, It has, The crankshaft is made thicker than the outer diameter D1 of the case, and the diameter dc2 of the crank journal is increased. like , 5.0 ≤ D1 / dc2 ≤ 6.5 Let's assume that.

[0043] According to one aspect of the present invention, by increasing the cross-sectional area of ​​the crank journal relative to the cross-sectional area of ​​the case when viewed in the axial direction of the case, that is, by making the crankshaft thicker as a balance for the reduction gear, the number of rollers arranged around the crank journal can be increased. At the same time, by setting the thickness of the rollers within an appropriate range, the number of rollers (needles) in contact with the crank journal can be increased, and the load applied to each roller can be reduced, thereby improving the damping performance of the reduction gear. Furthermore, by reducing the variation in the load applied to multiple rollers and simultaneously making the crankshaft thicker, rigidity can be improved. In other words, this gearbox improves rigidity and damping characteristics by increasing the number of physical contacts through a thicker crankshaft and the placement of numerous small-diameter rollers in the bearings.

[0044] A gearbox according to one aspect of the present invention comprises a case with an outer diameter D having internal teeth, A crankshaft having a crank journal with a diameter dc2, spaced by a diameter D2 from the central axis of the aforementioned case, It has, The crankshaft, which is spaced apart from the case by a diameter D2, is made thicker, and the diameter dc2 of the crank journal is increased. like , 2.5 ≤ D2 / dc2 ≤ 3.5 Let's assume that.

[0045] According to one aspect of the present invention, when viewed in the axial direction of the case, the cross-sectional area of ​​the crank journal is made larger than the cross-sectional area of ​​the case, and the crankshaft is positioned away from the central axis of the reduction gear. In other words, by making the crankshaft thicker and positioning it outward as a balance for the reduction gear, the number of rollers arranged around the crank journal can be increased. At the same time, by setting the thickness of the rollers within an appropriate range, the number of rollers (needles) in contact with the crank journal can be increased, and the load applied to a single roller can be reduced, thereby improving the damping performance of the reduction gear. Furthermore, by reducing the variation in the load applied to multiple rollers and simultaneously making the crankshaft thicker, rigidity can be improved. In other words, this gearbox improves rigidity and damping characteristics by increasing the number of physical contacts through a thicker crankshaft and the placement of numerous small-diameter rollers in the bearings.

[0046] A gearbox according to one aspect of the present invention comprises a case with an outer diameter D having internal teeth, A crankshaft that is spaced by a diameter D2 from the central axis of the aforementioned case, It has, The aforementioned crankshaft A crank journal with a diameter of dc2, A roller with diameter dr2 is arranged around the crank journal, Equipped with, Compared to the aforementioned case, the crankshaft is made thicker, and the diameter dc2 of the crank journal and the diameter dc1 of the eccentric body are set to optimize the load balance on the crankshaft. like , 6.0 ≤ dc² / dr² ≤ 9.0 Let's assume that.

[0047] According to one aspect of the present invention, by increasing the cross-sectional area of ​​the crank journal relative to the cross-sectional area of ​​the case when viewed in the axial direction of the case, that is, by making the crankshaft thicker as a balance for the reduction gear, the number of rollers arranged around the crank journal can be increased. At the same time, by setting the thickness of the rollers within an appropriate range, the number of rollers (needles) in contact with the crank journal can be increased, and the load applied to each roller can be reduced, thereby improving the damping performance of the reduction gear. Furthermore, by reducing the variation in the load applied to multiple rollers and simultaneously making the crankshaft thicker, rigidity can be improved. In other words, this gearbox improves rigidity and damping characteristics by increasing the number of physical contacts through a thicker crankshaft and the placement of numerous small-diameter rollers in the bearings.

[0048] A gearbox according to one aspect of the present invention comprises a case with an outer diameter D having internal teeth, A crankshaft that is spaced by a diameter D2 from the central axis of the aforementioned case, It has, The aforementioned crankshaft An eccentric body with diameter dc1, A crank journal with a diameter of dc2, Equipped with, Compared to the aforementioned case, the crankshaft is made thicker, and the diameter dc2 of the crank journal and the diameter dc1 of the eccentric body are set to optimize the load balance on the crankshaft. like , 0.85 ≤ dc² / dc¹ ≤ 1.0 Let's assume that.

[0049] According to one aspect of the present invention, by increasing the cross-sectional area of ​​the crank eccentric body and the crank journal relative to the cross-sectional area of ​​the case, that is, by making the crankshaft thicker as a balance for the reduction gear, the number of rollers arranged around the eccentric body and the crank journal can be increased. At the same time, by setting the thickness of the rollers within an appropriate range, the number of contact points between the rollers (needles) on the eccentric body and the crank journal can be increased, and the load applied to a single roller can be reduced, thereby improving the damping performance of the reduction gear. Furthermore, by reducing the variation in the load applied to multiple rollers and simultaneously making the crankshaft thicker, rigidity can be improved. In addition, by setting the thickness of the eccentric body, crank journal, and rollers within an appropriate range, the damping characteristics can be improved. In other words, this gearbox improves rigidity and damping characteristics by increasing the number of physical contacts through a thicker crankshaft and the placement of numerous small-diameter rollers in the bearings.

[0050] A gearbox according to one aspect of the present invention comprises a case with an outer diameter D having internal teeth, A crankshaft that is spaced by a diameter D2 from the central axis of the aforementioned case, It has, The aforementioned crankshaft An eccentric body with diameter dc1, A roller with diameter dr1 is arranged around the aforementioned eccentric body, n1 of which are n1. Equipped with, By increasing the diameter of the crankshaft compared to the aforementioned case, setting the diameter dc1 of the eccentric body and the diameter dr1 of the rollers, the number of rollers n1 is increased, and the occupancy rate of the rollers on the eccentric body is set, thereby increasing the number of contacts between the rollers and the eccentric body. like , 0.7≦ n1·dr1 / π(dc1+dr1) ≦0.9 Let's assume that.

[0051] According to one aspect of the present invention, by increasing the cross-sectional area of ​​the crank eccentric body relative to the cross-sectional area of ​​the case, that is, by making the crankshaft thicker as a balance for the reduction gear, the number of rollers arranged around the eccentric body can be increased. At the same time, by setting the thickness and number of rollers within an appropriate range, the number of rollers (needles) in contact with the eccentric body can be increased, and the load applied to each roller can be reduced, thereby improving the damping performance of the reduction gear. Furthermore, by reducing the variation in the load applied to multiple rollers and simultaneously making the crankshaft thicker, rigidity can be improved. In other words, this gearbox improves rigidity and damping characteristics by increasing the number of physical contacts through a thicker crankshaft and the placement of numerous small-diameter rollers in the bearings.

[0052] A gearbox according to one aspect of the present invention comprises a case with an outer diameter D having internal teeth, A crankshaft that is spaced by a diameter D2 from the central axis of the aforementioned case, It has, The aforementioned crankshaft An eccentric body with diameter dc1, A roller with diameter dr1 is arranged around the aforementioned eccentric body, n1 of which are n1. Equipped with, The number of rollers n1 is set as an arrangement corresponding to the eccentric body, and the number of contacts between the rollers and the eccentric body is increased. like , 15.3 ≤ n1 ≤ 28.3 Let's assume that.

[0053] According to one aspect of the present invention, by setting the number of rollers arranged around the eccentric body of the crank to an appropriate range, the number of rollers (needles) in contact with the eccentric body is increased, and the load applied to a single roller is reduced, thereby improving the damping performance of the reduction gear. Furthermore, by reducing the variation in the load applied to multiple rollers and simultaneously increasing the thickness of the crankshaft, rigidity can be improved. In other words, this gearbox improves rigidity and damping characteristics by increasing the number of physical contacts through a thicker crankshaft and the placement of numerous small-diameter rollers in the bearings.

[0054] A gearbox according to one aspect of the present invention comprises a case with an outer diameter D having internal teeth, A crankshaft that is spaced by a diameter D2 from the central axis of the aforementioned case, It has, The aforementioned crankshaft A crank journal with a diameter of dc2, Two rollers with diameter dr2 are arranged around the crank journal, Equipped with, By increasing the thickness of the crankshaft compared to the aforementioned case, and by setting the diameter dc2 of the crank journal and the diameter dr2 of the rollers, the number of rollers n2 is increased, and the occupancy rate of the rollers in the crank journal is set, thereby increasing the number of contacts between the rollers and the crank journal. like , 0.7≦ n2·dr2 / π(dc2+dr2) ≦0.9 Let's assume that.

[0055] According to one aspect of the present invention, by increasing the cross-sectional area of ​​the crank journal relative to the cross-sectional area of ​​the case, that is, by making the crankshaft thicker as a balance for the reduction gear, the number of rollers arranged around the crank journal can be increased. At the same time, by setting the thickness of the rollers within an appropriate range, the number of rollers (needles) in contact with the crank journal can be increased, and the load applied to each roller can be reduced, thereby improving the damping performance of the reduction gear. Furthermore, by reducing the variation in the load applied to multiple rollers and simultaneously making the crankshaft thicker, rigidity can be improved. In other words, this gearbox improves rigidity and damping characteristics by increasing the number of physical contacts through a thicker crankshaft and the placement of numerous small-diameter rollers in the bearings.

[0056] A gearbox according to one aspect of the present invention comprises a case with an outer diameter D having internal teeth, A crankshaft that is spaced by a diameter D2 from the central axis of the aforementioned case, It has, The aforementioned crankshaft A crank journal with a diameter of dc2, Two rollers with diameter dr2 are arranged around the crank journal, Equipped with, The number of rollers n2 is set to correspond to the crank journal, increasing the number of contacts between the rollers and the crank journal. like , 15.3 ≤ n² ≤ 28.3 Let's assume that.

[0057] According to one aspect of the present invention, by setting the number of rollers arranged around the crank journal to an appropriate range, the number of rollers (needles) in contact with the crank journal is increased, and the load applied to a single roller is reduced, thereby improving the damping performance of the reduction gear. Furthermore, by reducing the variation in the load applied to multiple rollers and simultaneously increasing the thickness of the crankshaft, rigidity can be improved. In other words, this gearbox improves rigidity and damping characteristics by increasing the number of physical contacts through a thicker crankshaft and the placement of numerous small-diameter rollers in the bearings. [Effects of the Invention]

[0058] According to the present invention, it is possible to achieve the effect of increasing the rigidity and damping of the gearbox. [Brief explanation of the drawing]

[0059] [Figure 1] This is a cross-sectional view along the crank axis showing a first embodiment of the reduction gear according to the present invention. [Figure 2] This is a cross-sectional view along line II-II in Figure 1. [Modes for carrying out the invention]

[0060] A first embodiment of the gearbox according to the present invention will be described below with reference to the drawings. Figure 1 is a cross-sectional view showing the speed reducer in this embodiment, and Figure 2 is a cross-sectional view showing the speed reducer along the line II-II in Figure 1. In the figures, reference numeral 100 denotes the speed reducer.

[0061] As shown in Figures 1 and 2, the reduction gear 100 according to this embodiment comprises a housing cylinder 200, a gear section (external tooth member) 300, and three crank assemblies 400. The housing cylinder 200 houses the gear section 300 and the three crank assemblies 400. In this embodiment, the speed reducer 100 is an eccentric oscillating speed reducer.

[0062] The housing cylinder 200 includes an outer cylinder portion (case) 210, a carrier portion (carrier) 220, and two main bearings 230. The carrier portion 220 is located inside the outer cylinder portion 210. The two main bearings 230 are located between the outer cylinder portion 210 and the carrier portion 220. The two main bearings 230 enable relative rotational motion between the outer cylinder portion 210 and the carrier portion 220. In this embodiment, the output section of the reduction gear 100 is exemplified by either the outer cylinder portion 210 or the carrier portion 220.

[0063] Figure 1 shows the central axis (main shaft) F0 of the reduction gear 100, which is defined as the rotational axis of the two main bearings 230. When the outer cylinder portion 210 is fixed, the carrier portion 220 rotates around the main shaft F0. When the carrier portion 220 is fixed, the outer cylinder portion 210 rotates around the main shaft F0. In other words, one of the outer cylinder portion 210 and the carrier portion 220 can rotate relative to the other of the outer cylinder portion 210 and the carrier portion 220 around the main shaft F0.

[0064] A mounting flange 215 is provided around the outer circumference of the cylindrical outer cylinder portion 210. Multiple mounting holes 216 are formed on the periphery of the mounting flange 215, spaced apart from each other. The mounting flange 215 is used, for example, when mounting the speed reducer 100 as a spigot.

[0065] The outer cylinder portion 210 includes an outer cylinder 211 and a plurality of internal tooth pins (internal teeth) 212. The outer cylinder 211 defines a cylindrical internal space in which the carrier portion 220, the gear portion 300, and the crank assembly 400 are housed. Each internal tooth pin 212 is a cylindrical member extending substantially parallel to the main shaft F0. Each internal tooth pin 212 is fitted into a groove formed in the inner wall of the outer cylinder 211. Thus, each internal tooth pin 212 is properly held by the outer cylinder 211.

[0066] Multiple internal tooth pins 212 are arranged at approximately constant intervals around the main spindle F0. The half-circumferential surface of each internal tooth pin 212 protrudes from the inner wall of the outer cylinder 211 toward the main spindle F0. Therefore, the multiple internal tooth pins 212 function as internal teeth that mesh with the gear section 300.

[0067] The carrier portion 220 includes a base portion 221, an end plate portion 222, a positioning pin 223, and a fixing bolt 224. The carrier portion 220 has an overall cylindrical shape. A through hole 229 is formed in the carrier portion 220 that is concentric with the main spindle F0. The base 221 includes a base plate portion 225 and three shaft portions 226. Each of the three shaft portions 226 extends from the base plate portion 225 toward the end plate portion 222. Screw holes 227 and reamed holes 228 are formed on the tip surface of each of the three shaft portions 226. Positioning pins 223 are inserted into the reamed holes 228. As a result, the end plate portion 222 is precisely positioned relative to the base 221. Fixing bolts 224 are screwed into the screw holes 227. As a result, the end plate portion 222 is properly fixed to the base 221.

[0068] The gear section 300 is positioned between the base plate section 225 and the end plate section 222. The three shaft sections 226 pass through the gear section 300 and are connected to the end plate section 222.

[0069] The gear section 300 includes two gears 310 and 320. Gear 310 is positioned between the base plate section 225 and gear 320. Gear 320 is positioned between the end plate section 222 and gear 310.

[0070] Gear 310 is approximately identical to gear 320 in shape and size. Gears 310 and 320 rotate around the outer cylinder 211 while meshing with the internal tooth pin 212. Therefore, the centers of gears 310 and 320 rotate around the main shaft F0.

[0071] The rotational phase of gear 310 is shifted by approximately 180° from the rotational phase of gear 320. Gear 310 meshes with half of the internal tooth pins 212 of the outer cylinder portion 210, while gear 320 meshes with the remaining half of the internal tooth pins 212. Therefore, the gear portion 300 can rotate the outer cylinder portion 210 or the carrier portion 220.

[0072] In this embodiment, the gear section 300 includes two gears 310 and 320. Alternatively, the gear section may use more than two gears. Furthermore, alternatively, the gear section may use one gear.

[0073] Each of the three crank assemblies 400 includes a crankshaft 410, four bearings 421, 422, 423, and 424, and a transmission gear (external teeth) 430. The transmission gear 430 may be a general spur gear. In the reduction gear 100 of this embodiment, the transmission gear 430 is not limited to a particular type.

[0074] The transmission gear 430 receives the driving force generated by the drive source (e.g., a motor) directly or indirectly. The reduction gear 100 can appropriately set the transmission path of the driving force from the drive source to the transmission gear 430 according to its operating environment and conditions. Therefore, this embodiment is not limited to a specific drive transmission path from the drive source to the transmission gear 430.

[0075] Figure 1 shows the crank axis (transmission axis) F2. The transmission axis F2 is approximately parallel to the main spindle F0. The crankshaft 410 rotates around the transmission axis F2. In Figure 1, the distance between the transmission axis F2 and the main spindle F0 is indicated by the symbol "D2h".

[0076] The crankshaft 410 includes two journals (crank journals) 411, 412 and two eccentric sections (eccentric bodies) 413, 414. The journals 411, 412 extend along the transmission shaft F2. The central axes of the journals 411, 412 coincide with the transmission shaft F2. The eccentric sections 413, 414 are formed between the journals 411, 412. Each of the eccentric sections 413, 414 is eccentric from the transmission shaft F2.

[0077] Journal 411 is inserted into bearing 421. Bearing 421 is positioned between journal 411 and end plate portion 222. Thus, journal 411 is supported by the end plate portion 222 and bearing 421. Journal 412 is inserted into bearing 422. Bearing 422 is positioned between journal 412 and base portion 221. Thus, journal 412 is supported by the base portion 221 and bearing 422. In this embodiment, bearing 421 is a needle bearing, with a plurality of rollers 431 arranged around journal 411. Bearing 422 is a needle bearing, with a plurality of rollers 432 arranged around journal 412.

[0078] The eccentric portion 413 is inserted into the bearing 423. The bearing 423 is positioned between the eccentric portion 413 and the gear 310. The eccentric portion 414 is inserted into the bearing 424. The bearing 424 is positioned between the eccentric portion 414 and the gear 320. In this embodiment, bearing 423 is a needle bearing, with a plurality of rollers 433 arranged around the eccentric portion (eccentric body) 413. Bearing 424 is a needle bearing, with a plurality of rollers 434 arranged around the eccentric portion (eccentric body) 414.

[0079] When a driving force is applied to the transmission gear 430, the crankshaft 410 rotates around the transmission shaft F2. As a result, the eccentric parts 413 and 414 rotate eccentrically around the transmission shaft F2. The gears 310 and 320, connected to the eccentric parts 413 and 414 via bearings 423 and 424, oscillate within the circular space defined by the outer cylinder 210. Since the gears 310 and 320 mesh with the internal tooth pins 212, a relative rotational motion is caused between the outer cylinder 210 and the carrier 220.

[0080] In this embodiment, the relationship between the dimensions and size of the gearbox 100 is set as follows.

[0081] Outer diameter D of mounting flange 215 Outer diameter D1 of outer cylinder (case) 210 The diameter D2 of the circle is the radius D2h, which is concentric with the main shaft F0 on which the crank axis (transmission shaft) F2 is located. Diameter dc1 of eccentric parts (eccentric bodies) 413, 414 Diameter dc2 of journals (crank journals) 411, 412 Diameter dimension dr1 of rollers 433,434 around eccentric parts (eccentric bodies) 413,414 Diameter dimension of rollers 431 and 432 around journal (crank journal) 411 and 412 dr2

[0082] 5.5≦D / dc1≦7.0 (Formula 1)

[0083] By setting it as shown in Equation 1, the crankshaft 410 becomes thicker relative to the outermost diameter of the case 210. In other words, compared to conventionally used speed reducers, the crankshaft 410 is made thicker to improve its rigidity. At the same time, by increasing the diameter dc1 of the eccentric parts (eccentric bodies) 413 and 414 and decreasing the roller diameter dr1, the number n1 of rollers 433 and 434 arranged around the eccentric parts (eccentric bodies) 413 and 414 is increased. Here, the diameter ratio of the crankshaft 410 can be set to match the size of the reduction gear 100.

[0084] This increases the number of line contacts between the roller 433 and the eccentric portion (eccentric body) 413. Increasing the number of contacts between the roller 433 and the eccentric portion 413 increases rigidity and reduces the unevenness in the load that each roller 433 receives from the eccentric portion 413, thereby suppressing the drop in damping as a bearing 423. Furthermore, setting the range as described above improves torsional rigidity compared to cases where the range is smaller. Conversely, setting it larger than this range is undesirable because it prevents the through-hole 229 from having the required diameter, and the roller diameter dr1 becomes too small, reducing durability.

[0085] Similarly, the number of line contacts between the roller 434 and the eccentric portion (eccentric body) 414 is increased. Increasing the number of contacts between the roller 434 and the eccentric portion 414 increases rigidity and reduces the unevenness in the load received by each roller 434 from the eccentric portion 414, thereby suppressing the drop in damping as a bearing 424. Furthermore, setting the range as described above improves torsional rigidity compared to cases where the range is smaller. Conversely, setting it larger than this range is undesirable because it prevents the through-hole 229 from having the required diameter, and the roller diameter dr1 becomes too small, reducing durability.

[0086] 4.5≦ D1 / dc1 ≦6.0 (Formula 2)

[0087] By setting it as shown in Equation 2, the crankshaft 410 becomes thicker relative to the case 210. In other words, the rigidity is improved by making the crankshaft 410 thicker compared to conventionally used speed reducers. At the same time, by increasing the diameter dc1 of the eccentric parts (eccentric bodies) 413 and 414 and decreasing the roller diameter dr1, the number n1 of rollers 433 and 434 arranged around the eccentric parts (eccentric bodies) 413 and 414 is increased.

[0088] This increases the number of line contacts between the roller 433 and the eccentric portion (eccentric body) 413. Increasing the number of contacts between the roller 433 and the eccentric portion 413 increases rigidity and reduces the unevenness in the load that each roller 433 receives from the eccentric portion 413, thereby suppressing the drop in damping as a bearing 423. Furthermore, setting the range as described above improves torsional rigidity compared to cases where the range is smaller. Conversely, setting it larger than this range is undesirable because it prevents the through-hole 229 from having the required diameter, and the roller diameter dr1 becomes too small, reducing durability.

[0089] Similarly, the number of line contacts between the roller 434 and the eccentric portion (eccentric body) 414 is increased. Increasing the number of contacts between the roller 434 and the eccentric portion 414 increases rigidity and reduces the unevenness in the load received by each roller 434 from the eccentric portion 414, thereby suppressing the drop in damping as a bearing 424. Furthermore, setting the range as described above improves torsional rigidity compared to cases where the range is smaller. Conversely, setting it larger than this range is undesirable because it prevents the through-hole 229 from having the required diameter, and the roller diameter dr1 becomes too small, reducing durability.

[0090] 2.0≦ D2 / dc1 ≦3.0 (Formula 3)

[0091] By setting it as shown in Equation 3, the crankshaft 410 is made thicker relative to the case 210, and its arrangement is set accordingly. In other words, compared to conventionally used speed reducers, the crankshaft 410 is made thicker to improve its rigidity. At the same time, by increasing the diameter dc1 of the eccentric parts (eccentric bodies) 413 and 414 and decreasing the roller diameter dr1, the number n1 of rollers 433 and 434 arranged around the eccentric parts (eccentric bodies) 413 and 414 is increased. Furthermore, the crankshaft 410, rollers 433 and 434, and carrier 220 can be arranged so that their rigidity is not reduced without them becoming unnecessarily small.

[0092] This increases the number of line contacts between the roller 433 and the eccentric portion (eccentric body) 413. Increasing the number of contacts between the roller 433 and the eccentric portion 413 increases rigidity and reduces the unevenness in the load that each roller 433 receives from the eccentric portion 413, thereby suppressing the drop in damping as a bearing 423. Furthermore, setting the range as described above improves torsional rigidity compared to cases where the range is smaller. Conversely, setting it larger than this range is undesirable because it prevents the through-hole 229 from having the required diameter, and the roller diameter dr1 becomes too small, reducing durability.

[0093] Similarly, the number of line contacts between the roller 434 and the eccentric portion (eccentric body) 414 is increased. Increasing the number of contacts between the roller 434 and the eccentric portion 414 increases rigidity and reduces the unevenness in the load received by each roller 434 from the eccentric portion 414, thereby suppressing the drop in damping as a bearing 424. Furthermore, setting the range as described above improves torsional rigidity compared to cases where the range is smaller. Conversely, setting it larger than this range is undesirable because it prevents the through-hole 229 from having the required diameter, and the roller diameter dr1 becomes too small, reducing durability.

[0094] 6.0≦dc1 / dr1≦9.0 (Formula 4)

[0095] By setting it as shown in Equation 4, the crankshaft 410 is made thicker than the case 210, and its arrangement is set accordingly. In other words, the crankshaft 410 is made thicker to improve its rigidity. At the same time, by setting the thickness of the rollers 433 and 434 arranged around the eccentric parts (eccentric bodies) 413 and 414 to a predetermined range relative to the diameter dc1 of the eccentric parts (eccentric bodies) 413 and 414, the number of rollers 433 and 434 n1 is increased compared to conventionally used speed reducers. Furthermore, the crankshaft 410, rollers 433 and 434, and carrier 220 can be arranged so that their rigidity is not reduced without them becoming unnecessarily small.

[0096] This increases the number of line contacts between the roller 433 and the eccentric portion (eccentric body) 413. Increasing the number of contacts between the roller 433 and the eccentric portion 413 increases rigidity and reduces the unevenness in the load that each roller 433 receives from the eccentric portion 413, thereby suppressing the drop in damping as a bearing 423. Furthermore, setting the range as described above improves torsional rigidity compared to cases where the range is smaller. Conversely, setting it larger than this range is undesirable because it prevents the through-hole 229 from having the required diameter, and the roller diameter dr1 becomes too small, reducing durability.

[0097] Similarly, the number of line contacts between the roller 434 and the eccentric portion (eccentric body) 414 is increased. Increasing the number of contacts between the roller 434 and the eccentric portion 414 increases rigidity and reduces the unevenness in the load received by each roller 434 from the eccentric portion 414, thereby suppressing the drop in damping as a bearing 424. Furthermore, setting the range as described above improves torsional rigidity compared to cases where the range is smaller. Conversely, setting it larger than this range is undesirable because it prevents the through-hole 229 from having the required diameter, and the roller diameter dr1 becomes too small, reducing durability.

[0098] 6.0≦D / dc2≦7.5 (Formula 5)

[0099] By setting it as shown in Equation 5, the crankshaft 410 becomes thicker relative to the outermost diameter of the case 210. In other words, the rigidity is improved by making the crankshaft 410 thicker than that of conventionally used speed reducers. At the same time, by increasing the diameter dc2 of the journals (crank journals) 411 and 412 and decreasing the roller diameter dr2, the number n2 of rollers 431 and 432 arranged around the journals (crank journals) 411 and 412 is increased. Here, the diameter dimension ratio of the crankshaft 410 can be matched to the size of the speed reducer 100.

[0100] This increases the number of line contacts between the roller 431 and the journal (crank journal) 411. Increasing the number of contacts between the roller 431 and the journal 411 increases rigidity and reduces the unevenness in the load that each roller 431 receives from the journal 411, thereby suppressing the drop in damping of the bearing 421. Furthermore, setting the range as described above improves torsional rigidity compared to cases where the range is smaller. Conversely, setting it larger than this range is undesirable because it prevents the through-hole 229 from having the required diameter, and the roller diameter dr2 becomes too small, reducing durability.

[0101] Similarly, the number of line contacts between the roller 432 and the journal (crank journal) 412 is increased. Increasing the number of contacts between the roller 432 and the journal 412 increases rigidity and reduces the unevenness in the load that each roller 432 receives from the journal 412, thereby suppressing the drop in damping as a bearing 424. Furthermore, setting the range as described above improves torsional rigidity compared to cases where the range is smaller. Conversely, setting it larger than this range is undesirable because it prevents the through-hole 229 from having the required diameter, and the roller diameter dr2 becomes too small, reducing durability.

[0102] 5.0≦ D1 / dc2 ≦6.5 (Formula 6)

[0103] By setting it as shown in Equation 6, the crankshaft 410 becomes thicker relative to the case 210. In other words, the rigidity is improved by making the crankshaft 410 thicker compared to conventionally used reducers. At the same time, by increasing the diameter dc2 of the journals (crank journals) 411 and 412 and decreasing the roller diameter dr2, the number n2 of rollers 431 and 432 arranged around the journals (crank journals) 411 and 412 is increased.

[0104] This increases the number of line contacts between the roller 431 and the journal (crank journal) 411. Increasing the number of contacts between the roller 431 and the journal 411 increases rigidity and reduces the unevenness in the load that each roller 431 receives from the journal 411, thereby suppressing the drop in damping of the bearing 421. Furthermore, setting the range as described above improves torsional rigidity compared to cases where the range is smaller. Conversely, setting it larger than this range is undesirable because it prevents the through-hole 229 from having the required diameter, and the roller diameter dr2 becomes too small, reducing durability.

[0105] Similarly, the number of line contacts between the roller 432 and the journal (crank journal) 412 is increased. Increasing the number of contacts between the roller 432 and the journal 412 increases rigidity and reduces the unevenness in the load that each roller 432 receives from the journal 412, thereby suppressing the drop in damping as a bearing 424. Furthermore, setting the range as described above improves torsional rigidity compared to cases where the range is smaller. Conversely, setting it larger than this range is undesirable because it prevents the through-hole 229 from having the required diameter, and the roller diameter dr2 becomes too small, reducing durability.

[0106] 2.5≦ D2 / dc2 ≦3.5 (Formula 7)

[0107] By setting it as shown in Equation 7, the crankshaft 410 is made thicker relative to the case 210, and its arrangement is set accordingly. In other words, compared to conventionally used reducers, the crankshaft 410 is made thicker to improve its rigidity. At the same time, by increasing the diameter dc2 of the journals (crank journals) 411 and 412 and decreasing the roller diameter dr2, the number n2 of rollers 431 and 432 arranged around the journals (crank journals) 411 and 412 is increased. Furthermore, the crankshaft 410, rollers 431 and 432, and carrier 220 can be arranged so that their rigidity is not reduced without them becoming unnecessarily small.

[0108] This increases the number of line contacts between the roller 431 and the journal (crank journal) 411. Increasing the number of contacts between the roller 431 and the journal 411 increases rigidity and reduces the unevenness in the load that each roller 431 receives from the journal 411, thereby suppressing the drop in damping of the bearing 421. Furthermore, setting the range as described above improves torsional rigidity compared to cases where the range is smaller. Conversely, setting it larger than this range is undesirable because it prevents the through-hole 229 from having the required diameter, and the roller diameter dr2 becomes too small, reducing durability.

[0109] Similarly, the number of line contacts between the roller 432 and the journal (crank journal) 412 is increased. Increasing the number of contacts between the roller 432 and the journal 412 increases rigidity and reduces the unevenness in the load that each roller 432 receives from the journal 412, thereby suppressing the drop in damping as a bearing 424. Furthermore, setting the range as described above improves torsional rigidity compared to cases where the range is smaller. Conversely, setting it larger than this range is undesirable because it prevents the through-hole 229 from having the required diameter, and the roller diameter dr2 becomes too small, reducing durability.

[0110] 6.0≦ dc2 / dr2 ≦9.0 (Formula 8)

[0111] By setting it as shown in Equation 8, the crankshaft 410 is made thicker relative to the case 210, and its arrangement is set accordingly. In other words, the crankshaft 410 is made thicker to improve its rigidity. At the same time, by setting the thickness of the rollers 431 and 432 arranged around the journals (crank journals) 411 and 412 to a predetermined range relative to the diameter dc2 of the journals (crank journals) 411 and 412, the number of rollers 431 and 432 n2 is increased compared to conventionally used reducers. Furthermore, the crankshaft 410, rollers 431 and 432, and carrier 220 can be arranged so that their rigidity is not reduced without them becoming unnecessarily small.

[0112] This increases the number of line contacts between the roller 431 and the journal (crank journal) 411. Increasing the number of contacts between the roller 431 and the journal 411 increases rigidity and reduces the unevenness in the load that each roller 431 receives from the journal 411, thereby suppressing the drop in damping of the bearing 421. Furthermore, setting the range as described above improves torsional rigidity compared to cases where the range is smaller. Conversely, setting it larger than this range is undesirable because it prevents the through-hole 229 from having the required diameter, and the roller diameter dr2 becomes too small, reducing durability.

[0113] Similarly, the number of line contacts between the roller 432 and the journal (crank journal) 412 is increased. Increasing the number of contacts between the roller 432 and the journal 412 increases rigidity and reduces the unevenness in the load that each roller 432 receives from the journal 412, thereby suppressing the drop in damping as a bearing 424. Furthermore, setting the range as described above improves torsional rigidity compared to cases where the range is smaller. Conversely, setting it larger than this range is undesirable because it prevents the through-hole 229 from having the required diameter, and the roller diameter dr2 becomes too small, reducing durability.

[0114] 0.85≦ dc2 / dc1 ≦1.0 (Formula 9)

[0115] By setting it as shown in Equation 9, the crankshaft 410 is made thicker relative to the case 210, and its arrangement is set accordingly. In other words, the crankshaft 410 is made thicker to improve its rigidity. At the same time, the balance between the thickness of the eccentric parts (eccentric bodies) 413, 414 and the thickness of the journals (crank journals) 411, 412 is adjusted to optimize the load balance on the crankshaft 410 axis. Furthermore, by setting the relationship between the number and thickness of the rollers 433, 434 and rollers 431, 432 arranged around the eccentric parts (eccentric bodies) 413, 414 and the journals (crank journals) 411, 412 to a predetermined range, the number of rollers 433, 434 n1 and the number of rollers 431, 432 n2 are made larger and more appropriate compared to conventionally used speed reducers. Furthermore, the crankshaft 410 and rollers 431-434 are not made unnecessarily small, and the carrier 220 does not have a thin-walled shape, thus preventing a decrease in their rigidity.

[0116] 0.7≦ n1·dr1 / π(dc1+dr1) ≦0.9 (Equation 10)

[0117] By setting it as shown in Equation 10, the ratio of the circumferential length occupied by the number n1 of rollers 433,434 to the perimeter length of the eccentric parts (eccentric bodies) 413,414, that is, the occupancy rate of the rollers 433,434 in the eccentric parts (eccentric bodies) 413,414 can be set to a predetermined range. Therefore, the crankshaft 410 is made thicker than the case 210, and its arrangement is set accordingly. In other words, the crankshaft 410 is made thicker to improve its rigidity. At the same time, by setting the thickness of the rollers 433 and 434 arranged around the eccentric parts (eccentric bodies) 413 and 414 to a predetermined range relative to the thickness of the eccentric parts (eccentric bodies) 413 and 414, the number n1 of rollers 433 and 434 is increased compared to conventionally used speed reducers. Furthermore, the crankshaft 410 and rollers 433 and 434 are not made unnecessarily small, and the carrier 220 does not become thin-walled, so that their rigidity is not reduced.

[0118] This increases the number of line contacts between the roller 433 and the eccentric portion (eccentric body) 413. Increasing the number of contacts between the roller 433 and the eccentric portion 413 increases rigidity and reduces the unevenness in the load that each roller 433 receives from the eccentric portion 413, thereby suppressing the drop in damping as a bearing 423. Furthermore, setting the value within the above range improves torsional rigidity compared to cases where the value is smaller. Conversely, setting the value larger than this range is undesirable because it compromises the bearing cage strength.

[0119] Similarly, the number of line contacts between the roller 434 and the eccentric portion (eccentric body) 414 is increased. Increasing the number of contacts between the roller 434 and the eccentric portion 414 increases rigidity and reduces the unevenness in the load received by each roller 434 from the eccentric portion 414, thereby suppressing the drop in damping as a bearing 424. Furthermore, setting the value within the above range improves torsional rigidity compared to cases where the value is smaller. Conversely, setting the value larger than this range is undesirable because it compromises the bearing cage strength.

[0120] 15.3≦n1≦28.3 (Formula 11)

[0121] By setting it as shown in Equation 11, the occupancy rate of the rollers 433 and 434 in the eccentric parts (eccentric bodies) 413 and 414 can be set to a predetermined range as the number n1. Therefore, the crankshaft 410 is made thicker than the case 210, and its arrangement is set accordingly. In other words, the crankshaft 410 is made thicker to improve its rigidity. At the same time, by setting the thickness of the rollers 433 and 434 arranged around the eccentric parts (eccentric bodies) 413 and 414 to a predetermined range relative to the thickness of the eccentric parts (eccentric bodies) 413 and 414, the number n1 of rollers 433 and 434 is increased compared to conventionally used speed reducers. Furthermore, the crankshaft 410 and rollers 433 and 434 are not made unnecessarily small, and the carrier 220 does not become thin-walled, so that their rigidity is not reduced.

[0122] This increases the number of line contacts between the roller 433 and the eccentric portion (eccentric body) 413. Increasing the number of contacts between the roller 433 and the eccentric portion 413 increases rigidity and reduces the unevenness in the load that each roller 433 receives from the eccentric portion 413, thereby suppressing the drop in damping as a bearing 423. Furthermore, setting the range as described above improves torsional rigidity compared to cases where the range is smaller. Conversely, setting it larger than this range is undesirable because it prevents the through-hole 229 from having the required diameter.

[0123] Similarly, the number of line contacts between the roller 434 and the eccentric portion (eccentric body) 414 is increased. Increasing the number of contacts between the roller 434 and the eccentric portion 414 increases rigidity and reduces the unevenness in the load received by each roller 434 from the eccentric portion 414, thereby suppressing the drop in damping as a bearing 424. Furthermore, setting the range as described above improves torsional rigidity compared to cases where the range is smaller. Conversely, setting it larger than this range is undesirable because it prevents the through-hole 229 from having the required diameter.

[0124] 0.7≦ n2·dr2 / π(dc2+dr2) ≦0.9 (Equation 12)

[0125] By setting it as shown in Equation 12, the ratio of the circumferential length occupied by the rollers 431 and 432, which are arranged in a number n2, to the perimeter length of the journals (crank journals) 411 and 412, that is, the occupancy rate of the rollers 431 and 432 in the journals (crank journals) 411 and 412, can be set to a predetermined range. Therefore, the crankshaft 410 is made thicker than the case 210, and its arrangement is set accordingly. In other words, the crankshaft 410 is made thicker to improve its rigidity. At the same time, by setting the thickness of the rollers 431 and 432 arranged around the journals (crank journals) 411 and 412 to a predetermined range relative to the thickness of the journals (crank journals) 411 and 412, the number n2 of rollers 431 and 432 is increased compared to conventionally used speed reducers. Furthermore, the crankshaft 410 and rollers 431 and 432 are not made unnecessarily small, and the carrier 220 does not become thin-walled, so that their rigidity is not reduced.

[0126] This increases the number of line contacts between the roller 431 and the journal (crank journal) 411. Increasing the number of contacts between the roller 431 and the journal 411 increases rigidity and reduces the unevenness in the load that each roller 431 receives from the journal 411, thereby suppressing the drop in damping of the bearing 421. Furthermore, setting the value within the above range improves torsional rigidity compared to cases where the value is smaller. Conversely, setting the value larger than this range is undesirable because it compromises the bearing cage strength.

[0127] Similarly, the number of line contacts between the roller 432 and the journal (crank journal) 412 is increased. Increasing the number of contacts between the roller 432 and the journal 412 increases rigidity and reduces the unevenness in the load that each roller 432 receives from the journal 412, thereby suppressing the drop in damping as a bearing 424. Furthermore, setting the value within the above range improves torsional rigidity compared to cases where the value is smaller. Conversely, setting the value larger than this range is undesirable because it compromises the bearing cage strength.

[0128] 15.3≦n2≦28.3 (Formula 13)

[0129] By setting it as shown in Equation 13, the occupancy rate of the rollers 431 and 432 in the journals (crank journals) 411 and 412 can be set to a predetermined range as the number n2. Therefore, the crankshaft 410 is made thicker than the case 210, and its arrangement is set accordingly. In other words, the crankshaft 410 is made thicker to improve its rigidity. At the same time, by setting the thickness of the rollers 431 and 432 arranged around the journals (crank journals) 411 and 412 to a predetermined range relative to the thickness of the journals (crank journals) 411 and 412, the number n2 of rollers 431 and 432 can be increased compared to conventionally used reducers. Furthermore, the crankshaft 410 and rollers 431 and 432 are not made unnecessarily small, and the carrier 220 does not become thin-walled, so that their rigidity is not reduced.

[0130] This increases the number of line contacts between the roller 431 and the journal (crank journal) 411. Increasing the number of contacts between the roller 431 and the journal 411 increases rigidity and reduces the unevenness in the load that each roller 431 receives from the journal 411, thereby suppressing the drop in damping of the bearing 421. Furthermore, setting the range as described above improves torsional rigidity compared to cases where the range is smaller. Conversely, setting it larger than this range is undesirable because it prevents the through-hole 229 from having the required diameter.

[0131] Similarly, the number of line contacts between the roller 432 and the journal (crank journal) 412 is increased. Increasing the number of contacts between the roller 432 and the journal 412 increases rigidity and reduces the unevenness in the load that each roller 432 receives from the journal 412, thereby suppressing the drop in damping as a bearing 424. Furthermore, setting the range as described above improves torsional rigidity compared to cases where the range is smaller. Conversely, setting it larger than this range is undesirable because it prevents the through-hole 229 from having the required diameter.

[0132] In the speed reducer 100 of this embodiment, by thickening the crankshaft 410 to improve rigidity and setting the rollers 431 to 434 to a predetermined thickness and increasing the numbers n1 and n2, in response to the size perception of the speed reducer 100, uneven loads on the rollers 431 to 434 can be reduced to prevent a decline in attenuation, and while maintaining durability, it becomes possible to increase rigidity and increase attenuation.

[0133] Furthermore, in this embodiment, since the rigidity and attenuation performance of the speed reducer are improved, in applications such as robots, it leads to an increase in operating speed and suppression of vibrations during operation stop. At the same time, by increasing the friction inside the speed reducer, the effect of improving controllability can also be achieved.

[0134] The principles of the various embodiments described above may be combined to conform to the requirements for the speed reducer.

Industrial Applicability

[0135] As an example of the utilization of the present invention, all gear devices having a crankshaft and a cylindrical roller bearing can be cited.

Explanation of Signs

[0136] 100…Speed reducer 200…Housing cylinder 210…Outer cylinder part (case) 211…Outer cylinder 212…Internal gear pin (internal gear) 215…Mounting flange 216…Mounting hole 220…Carrier part (carrier) 221…Base part 222…End plate part 223…Pin 224…Fixing bolt 225…Substrate part 226…Shaft part 227…Thread hole 228…Reamer hole 229…Through hole [[ID=​​​​ 320... Gear 400... Crank assembly 410... Crank axle 411... Journal (Crank Journal) 412... Journal (Crank Journal) 413...Eccentric part (eccentric body) 414...Eccentric part (eccentric body) 421~424…Bearings 430... Transmission gear (external teeth) 431~434... Koro D…Outer diameter D1…Outer diameter D2…Diameter D2h…radius dc1…Diameter dc2…diameter dr1…Diameter dimension dr2…Diameter dimensions F0…Center axis (main axis) F2... Crank axis (transmission axis) n1... Number of items n2... Number of items

Claims

[Claim 1] A cylindrical case having internal teeth and an outer diameter D1, A mounting flange with an outer diameter D is provided around the outer circumference of the aforementioned case, A plurality of crankshafts having external teeth that are concentric with the central axis of the case, arranged circumferentially spaced apart from each other on a circle with diameter D2, and rotating around a crankshaft parallel to the central axis of the case, A plurality of external tooth members having external teeth that mesh with the internal teeth of the case and which move eccentrically by the crankshaft, A carrier that rotatably supports the crankshaft and rotates relative to the case by the crankshaft, It has, The aforementioned crankshaft An eccentric body with diameter dc1, A crank journal with a diameter of dc2, A needle bearing with diameter dr1, with n1 rollers arranged around the eccentric body, Two needle bearing rollers, with a diameter of dr2, are arranged around the crank journal, It has, The outer diameter D of the mounting flange and the diameter dc1 of the eccentric body are, 5.5≦D / dc1≦7.0 Set to the range, The outer diameter D1 of the case and the diameter dc1 of the eccentric body are, 4.5≦D1 / dc1≦6.0 Set to the range, The diameter D2 of the circle where the crank axis is positioned, which is concentric with the central axis of the case, and the diameter dc1 of the eccentric body are defined as follows: 2.0≦D2 / dc1≦3.0 Set to the range, The diameter dc1 of the eccentric body and the diameter dimension dr1 of the roller are, 6.0≦dc1 / dr1≦9.0 Set to the range, The outer diameter D of the mounting flange and the diameter dc2 of the crank journal are, 6.0≦D / dc2≦7.5 Set to the range, The outer diameter D1 of the case and the diameter dc2 of the crank journal are 5.0≦D1 / dc2≦6.5 Set to the range, The diameter D2 and the diameter dc2 of the crank journal are 2.5≦D2 / dc2≦3.5 Set to the range, The diameter dc2 of the crank journal and the diameter dimension dr2 of the roller are, 6.0≦dc2 / dr2≦9.0 Set to the range, The diameter dc2 of the crank journal and the diameter dc1 of the eccentric body are 0.85≦dc2 / dc1≦1.0 Set to the range, The diameter dc1 of the eccentric body and the diameter dr1 and number n1 of the rollers are, 0.7≦n1・dr1 / π(dc1+dr1)≦0.9 Set to the range, The number of rollers n1 is 15.3≦n1≦28.3 Set to the range, The diameter dc2 of the crank journal, the diameter dr2 of the roller, and the number n2 of the rollers are, 0.7≦n2・dr2 / π(dc2+dr2)≦0.9 Set to the range, The number of rollers n2 is 15.3≦n2≦28.3 Set to the range, reducer.

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