TW201335512A - Gear transmission device - Google Patents

Abstract

First outer teeth (14a) each have a first machined section (142) at one of the ends thereof, and the tooth surface of the first machined section (142) is machined so that the tooth surface extends inward in the radial direction as the tooth surface extends toward an end thereof in the axial direction. Second teeth (16a) each have a machined section (162) at one of the ends thereof, and the tooth surface of the second machined section (162) is machined so that the tooth surface extends inward in the radial direction as the tooth surface extends toward an end thereof in the axial direction. Inner tooth pins (3) are each provided with: a first reduced diameter section (31) provided at the portion of the inner tooth pin (3) which corresponds in the radial direction to an end of each of the first outer teeth (14a), the end being on the side on which the first machined section (142) is not provided; and a second reduced diameter section (32) provided at the portion of the inner tooth pin (3) which corresponds in the radial direction to an end of each of the second outer teeth (16a), the end being on the side on which the second machined section (162) is not provided.

Description

Gear transmission

The invention relates to a gear transmission.

Conventionally, an eccentric oscillating type gear transmission (for example, refer to Patent Document 1) which is engaged with an internal tooth pin of an internal gear by interlocking with an eccentric rotation of a crankshaft is known. The tooth gear swings and rotates to obtain an output rotation that decelerates the input speed.

In the gear transmission described in Patent Document 1, a plurality of internal tooth pins that mesh with two external gears are provided. Each of the internal tooth pins has a first meshing portion, a second meshing portion, and a connecting portion that connects the first meshing portion and the second meshing portion. The ridge processing is applied to both axial end portions of the meshing portions (Fig. 3 and Fig. 6 of Patent Document 1). Thereby, the edge stress generated between the tooth surface of each of the externally toothed gears and the outer peripheral surface of the inner toothed pin at both axial end portions of the respective meshing portions is reduced. Further, in the seventh drawing of Patent Document 1, the notch is not only the inner pin but also the tooth surfaces of the both end portions of the externally toothed gear are embossed, and the teeth at the both end portions of the external gear are further reduced. The edge stress generated between the surface and the outer peripheral surface of the axial end portions of the respective meshing portions of the inner tooth pin.

However, in the gear transmission described in the third and sixth drawings of Patent Document 1, since both ends of the first meshing portion of each of the internal tooth pins are required to be embossed, both ends of the second meshing portion are required. Since the ridge processing is applied and the process of joining the meshing portions is connected by the connecting portion, there is a problem that the cost is increased. In addition, as shown in the seventh drawing of Patent Document 1, when the burring process is applied to both end portions of the externally toothed gears, the number of man-hours required for the bulging process is increased, and the cost is increased.

[Advanced technical literature] [Patent Literature]

[Patent Document 1] JP-A-2009-293650

SUMMARY OF THE INVENTION An object of the present invention is to provide a gear transmission apparatus which can suppress an increase in the amount of edge stress between an externally toothed gear and an internal toothed pin while suppressing an increase in cost.

The gear transmission device of the present invention comprises: an outer cylinder having inner circumferential surfaces of a plurality of pin grooves extending in the axial direction at predetermined intervals; a plurality of inner tooth pins disposed in the plurality of pin grooves Each of the crankshafts has a first eccentric portion and a second eccentric portion arranged in the axial direction with a predetermined phase difference, and is disposed to be rotatable about the shaft in the outer cylinder; the first external gear The outer peripheral surface of the first outer tooth is attached to the first eccentric portion, and the first outer tooth meshes with the inner tooth pin to swing and rotate in conjunction with the eccentric rotation of the first eccentric portion; The second externally toothed gear has an outer peripheral surface on which the second external tooth is provided, and is attached to the second eccentric portion, and the second external tooth meshes with the internal toothed pin to interlock with the eccentric rotation of the second eccentric portion. The oscillating rotation is performed; and the carrier is conveyed by the oscillating rotation of the first externally toothed gear and the second externally toothed gear, and the outer cylinder is relatively rotated.

The first external tooth system has the first processing at one end of the axial direction unit. The tooth surface of the first processed portion is processed to be located radially inward with the end portion in the axial direction of the tooth surface. The second external tooth system has a second processed portion at one of the axial ends. The tooth surface of the second processed portion is processed to be located radially inward with the end portion in the axial direction of the tooth surface.

Each of the internal tooth pins has a first reduced diameter portion and a second reduced diameter portion. The first reduced diameter portion is processed such that a portion that faces in the radial direction and an end portion of the first external tooth on the side where the first processed portion is not provided is reduced in diameter in the axial direction. The second reduced diameter portion is processed to be reduced in diameter in the axial direction at a portion facing the end portion of the second external tooth on the side where the second processed portion is not provided.

Hereinafter, a gear transmission 1 according to an embodiment of the present invention will be described in detail with reference to the drawings. The gear transmission 1 is used as a speed reducer, and is applied to, for example, a rotating portion of a robot, a rotating portion such as a wrist joint, a rotating portion of various machine tools, and the like.

<First embodiment> (The overall construction of the gear transmission)

In the gear transmission 1 of the first embodiment, the first externally toothed gear 14 is oscillated and rotated in conjunction with the first eccentric portion 10a of the crankshaft 10, and the second external gear 16 and the second eccentric portion of the crankshaft 10 are provided. 10b swings in conjunction with the rotation to obtain an output rotation that is decelerated more than the input rotational speed.

As shown in Fig. 1, the gear transmission 1 includes an outer cylinder 2, a plurality of internal tooth pins 3, a carrier 4, an input shaft 8, a plurality of (for example, three) crankshafts 10, and a first externally toothed gear 14, 2 external gear 16 and a plurality (for example, 3) The gear 20 is conveyed.

As shown in Fig. 2, the outer cylinder 2 constitutes the outer surface of the gear transmission 1, and has a substantially cylindrical shape. A plurality of pin grooves 2b are formed on the inner circumferential surface of the outer cylinder 2. Each of the pin grooves 2b extends in the axial direction of the outer cylinder 2, and has a semicircular cross-sectional shape in a cross section orthogonal to the axial direction. These pin grooves 2b are arranged at equal intervals in the circumferential direction on the inner circumferential surface of the outer cylinder 2.

Each of the internal tooth pins 3 is attached to a corresponding pin groove 2b. Specifically, each of the internal tooth pins 3 is fitted into a corresponding pin groove 2b. The axial direction of each of the internal tooth pins 3 extends along the axial direction of the outer cylinder 2. Therefore, the plurality of internal tooth pins 3 are arranged at equal intervals along the circumferential direction of the outer cylinder 2. In the pin groove 2b, each of the internal tooth pins 3 is rotatable about its axis. The first externally toothed gear 14 and the second externally toothed gear 16 mesh with the internal toothed pins 3. The detailed structure of the internal tooth pin 3 will be described later.

As shown in Fig. 1, the carrier 4 is housed in the outer cylinder 2 in a state of being placed coaxially with the outer cylinder 2. The carrier 4 is rotated relative to the outer cylinder 2 about the same axis. Specifically, the carrier 4 is supported by the carrier bearing 6 so as to be relatively rotatable relative to the outer cylinder 2 by being disposed apart from each other in the axial direction. In the present embodiment, the carrier 4 includes a base portion 4a, an end plate portion 4b, and a plurality of (for example, three) shaft portions 4c. However, it is not limited to this configuration.

The base portion 4a is disposed in the outer tube 2 at one end side in the axial direction of the outer tube 2. A circular through hole 4d is provided in a radial central portion of the base portion 4a. A plurality of (for example, three) crankshaft mounting holes 4e (hereinafter simply referred to as mounting holes 4e) are provided at equal intervals in the circumferential direction around the through hole 4d.

The end plate portion 4b is provided separately from the base portion 4a in the axial direction, and is disposed in the outer tube 2 at the other end portion of the outer tube 2 in the axial direction. The through hole 4f is disposed on the end plate The radial center portion of the portion 4b. Around the through hole 4f, a plurality of (for example, three) crankshaft mounting holes 4g (hereinafter simply referred to as mounting holes 4g) are provided at positions corresponding to the plurality of mounting holes 4e of the base portion 4a. The closed space is formed in the outer cylinder 2, and the closed space is surrounded by the inner surface of both the end plate portion 4b and the base portion 4a facing each other and the inner circumferential surface of the outer cylinder 2.

The three shaft portions 4c are integrally provided on the base portion 4a, and linearly extend from the base portion 4a toward the end plate portion 4b side. The three shaft portions 4c are arranged at equal intervals in the circumferential direction (see Fig. 2). Each of the shaft portions 4c is locked to the end plate portion 4b by a bolt 4h (see Fig. 1). Thereby, the base portion 4a, the shaft portion 4c, and the end plate portion 4b are integrated.

The input shaft 8 functions as an input portion for inputting rotation by a drive motor (not shown). The input shaft 8 is inserted into the through hole 4f of the end plate portion 4b and the through hole 4d of the base portion 4a. The input shaft 8 is arranged such that its axis coincides with the axis of the outer cylinder 2 and the carrier 4. The input shaft 8 rotates about its axis. The input gear 8a is provided on the outer peripheral surface of the tip end portion of the input shaft 8.

The three crankshafts 10 are disposed around the input shaft 8 at equal intervals in the outer cylinder 2 (see FIG. 2). Each of the crankshafts 10 is attached to a mounting hole 4e of the corresponding base portion 4a and a mounting hole 4g of the end plate portion 4b (see Fig. 1). Specifically, a portion of each of the crankshafts 10 that is axially inner with respect to one end in the axial direction is attached to the mounting hole 4e of the base portion 4a via the first crank bearing 12a. On the other hand, the other end of the crankshaft 10 in the axial direction is attached to the attachment hole 4g of the end plate portion 4b via the second crank bearing 12b. Each of the crankshafts 10 is supported by two crank bearings 12a, 12b for pivoting the carrier 4.

Each of the crankshafts 10 has a first eccentric portion 10a and a second eccentric portion 10b that are disposed between the portions supported by the two crank bearings 12a and 12b so as to be aligned in the axial direction. Each of the first eccentric portion 10a and the second eccentric portion 10b has a cylindrical shape. Each of the first eccentric portion 10a and the second eccentric portion 10b is eccentric from the axial center of the crankshaft 10 by a predetermined eccentric amount, and is disposed to have a phase difference of a predetermined angle from each other. Moreover, the fitted portion 10c to which the transmission gear 20 is attached is provided at a portion closer to the axially outer side than the one end portion of the crank shaft 10, that is, the portion that is attached to the attachment hole 4e of the base portion 4a.

As shown in FIGS. 1 and 2, the first externally toothed gear 14 is disposed in the closed space in the outer cylinder 2. The first externally toothed gear 14 is attached to the first eccentric portion 10a of each of the crankshafts 10 via the first rolling bearing 18a. When the first external gear 14 rotates and the first eccentric portion 10a is eccentrically rotated, the first external gear 14 is oscillated and rotated while meshing with the internal tooth pin 3 in conjunction with the eccentric rotation.

The first externally toothed gear 14 has a size smaller than the inner diameter of the outer cylinder 2. In the present embodiment, the first externally toothed gear 14 has a first external tooth 14a, a central portion through hole 14b, a plurality of (for example, three) first eccentric portion insertion holes 14c, and a plurality of (for example, three) shaft insertion holes. 14d. However, it is not limited to this configuration.

As shown in FIG. 2, the center portion through hole 14b is provided in the radial center portion of the first externally toothed gear 14. The input shaft 8 is inserted into the center portion through hole 14b in a state of having a play.

The three first eccentric portion insertion holes 14c are provided around the center portion through hole 14b at equal intervals in the circumferential direction of the first externally toothed gear 14. The first eccentricity of the corresponding crankshaft 10 is set in a state in which the first rolling bearing 18a is inserted The portion 10a is inserted into each of the first eccentric portion insertion holes 14c.

The three shaft insertion holes 14d are provided around the center portion through hole 14b at equal intervals in the circumferential direction of the first externally toothed gear 14. Each of the shaft insertion holes 14d is disposed at a position between the three first eccentric portion insertion holes 14c in the circumferential direction. The corresponding shaft portion 4c is inserted into each of the shaft portion insertion holes 14d in a state of having a play. The detailed structure of the first outer teeth 14a will be described later.

The second externally toothed gear 16 is disposed in the closed space in the outer cylinder 2 . The second externally toothed gear 16 is attached to the second eccentric portion 10b of each of the crankshafts 10 via the second rolling bearing 18b. The first externally toothed gear 14 and the second externally toothed gear 16 are arranged in the axial direction so as to correspond to the arrangement of the first eccentric portion 10a and the second eccentric portion 10b. When the second external gear 16 rotates and the second eccentric portion 10b is eccentrically rotated, the second external gear 16 is oscillated and rotated while meshing with the internal tooth pin 3 in conjunction with the eccentric rotation.

The second externally toothed gear 16 has a size smaller than the inner diameter of the outer cylinder 2. In the present embodiment, the second externally toothed gear 16 has a second external tooth 16a, a central portion through hole 16b, a plurality of (for example, three) second eccentric portion insertion holes 16c, and a plurality of (for example, three) shaft insertion holes. 16d. However, it is not limited to this configuration. These members have the same structure as the first outer teeth 14a of the first externally toothed gear 14, the center portion through hole 14b, the plurality of first eccentric portion insertion holes 14c, and the plurality of shaft portion insertion holes 14d. The second eccentric portion 10b of the corresponding crankshaft 10 is inserted into each of the second eccentric portion insertion holes 16c in a state in which the second rolling bearing 18b is inserted. The detailed structure of the second external teeth 16a will be described later.

Each of the transmission gears 20 transmits the rotation of the input gear 8a to the corresponding crankshaft 10. Each of the communication gears 20 is externally embedded in the corresponding crankshaft 10 One of the ends of the fitted portion 10c. Each of the transmission gears 20 rotates integrally with the crankshaft 10 about the same axis as the rotation axis of the crankshaft 10. Each of the transmission gears 20 has external teeth 20a that mesh with the input gear 8a.

(Structure of internal tooth pin)

As shown in Figs. 2 to 4, each of the internal tooth pins 3 has a substantially cylindrical shape. Each of the internal tooth pins 3 is formed by cutting and/or grinding a single rod-shaped metal material. In the present embodiment, the outer peripheral surface of each inner tooth pin 3 is subjected to a grinding process of cutting and/or polishing. Therefore, the outer diameters of the axial end portions of the inner tooth pins 3 are smaller than the outer diameters of the portions between the inner teeth. Specifically, it is as follows.

Each of the internal tooth pins 3 has a first reduced diameter portion 31 at an end portion on one side in the axial direction, a second reduced diameter portion 32 at an end portion on the other side in the axial direction, and a plurality of reduced diameter portions. A columnar portion (intermediate portion) 33 between 31 and 32. In each of the internal tooth pins 3, the first reduced diameter portion 31, the columnar portion 33, and the second reduced diameter portion 32 are integrally formed in this order in the axial direction. The first reduced diameter portion 31, the columnar portion 33, and the second reduced diameter portion 32 are circular in cross section orthogonal to each other in the axial direction.

The columnar portion 33 has a cylindrical shape whose outer diameter is constant in the axial direction. The first reduced diameter portion 31 has a tapered shape. The outer diameter of the first reduced diameter portion 31 gradually decreases as it goes toward the end side on one side in the axial direction. The second reduced diameter portion 32 has a tapered shape. The outer diameter of the second reduced diameter portion 32 gradually decreases as it goes toward the other end side in the axial direction. Therefore, in each of the internal tooth pins 3, the outer diameter of the columnar portion 33 is the largest. The outer peripheral surface of the first reduced diameter portion 31 and the outer peripheral surface of the second reduced diameter portion 32 are curved surfaces that are convex outward. The outer peripheral surface of the first reduced diameter portion 31 and the outer peripheral surface of the second reduced diameter portion 32 are smoothly curved toward the respective end sides.

The columnar portion 33 is a portion where the first externally toothed gear 14 and the second externally toothed gear 16 mesh. Specifically, as shown in FIG. 3 and FIG. 4 , the portion on the side of the first reduced diameter portion 31 is provided in the radial direction and the first externally toothed gear 14 from the vicinity of the center in the axial direction of the columnar portion 33 . The first outer teeth 14a are in a position facing each other, and the first outer teeth 14a are engaged with the portions. On the other hand, the portion on the side of the second reduced diameter portion 32 is provided at a position facing the second outer teeth 16a of the second externally toothed gear 16 in the radial direction from the vicinity of the center in the axial direction of the columnar portion 33. 2 The external teeth 16a are engaged with the portion.

The first reduced diameter portion 31 is provided at a position facing the axially outer end portion of the first external tooth 14a in the radial direction. The second reduced diameter portion 32 is provided at a position facing the axially outer end portion of the second external tooth 16a in the radial direction.

(Structure of external teeth)

As shown in FIG. 2, the first external teeth 14a are provided on the outer peripheral surface of the first externally toothed gear 14. The tooth surface of the first external tooth 14a is a cross section (cross section shown in Fig. 2) orthogonal to the axial direction, and has a waveform that is smoothly connected in the entire circumferential direction. In other words, the tooth flanks of the first outer teeth 14a are alternately arranged in the circumferential direction on the tooth tips on the radially outer side and the valley portions on the radially inner side.

Each of the tooth tops and each of the valley portions has a substantially circular arc shape in a cross section orthogonal to the axial direction. A plurality of tooth tops and a plurality of valley portions form a smooth curved surface as a whole. Here, the boundary between the tooth top and the valley portion adjacent to each other is in the radial direction of the first externally toothed gear 14, at the tip end (the crown) of the outermost tooth top and the bottom of the innermost toothed portion. The part on the tooth surface of the center.

The number of teeth of the first external teeth 14a is set to be smaller than the number of the inner tooth pins 3 less. In the present embodiment, the number of teeth of the first external teeth 14a is set to be one less than the number of the internal tooth pins 3. However, it is not limited to this configuration. The second external teeth 16a have the same structure as the above-described first external teeth 14a.

As shown in FIGS. 3 and 4, the first external teeth 14a mesh with the portion of the columnar portion 33 of the internal tooth pin 3 on the side of the first reduced diameter portion 31. The second external teeth 16a mesh with a portion on the second reduced diameter portion 32 side of the columnar portion 33 of the internal tooth pin 3. The first outer teeth 14 a have a first outer tooth main body portion 141 and a first processed portion 142 . The second external teeth 16 a have a second outer tooth main portion 161 and a second processed portion 162 .

The first external tooth main body portion 141 is a portion whose tooth surface is parallel to the axial direction. The first external tooth main body portion 141 is an end edge extending in the axial direction from a boundary portion with the first processed portion 142 to a tooth surface opposite to the first processed portion 142 . The first external tooth main body portion 141 faces the first reduced diameter portion 31 of the internal tooth pin 3 in the radial direction, and faces the part of the columnar portion 33 of the internal tooth pin 3 in the radial direction. In the axial direction, a part of the first external tooth main body portion 141 is located closer to the second external teeth 16a than the first reduced diameter portion 31 of the internal tooth pin 3. The length of the first external tooth main body portion 141 in the axial direction is longer than the axial length of the first processed portion 142.

The second external tooth main body portion 161 is a portion whose tooth surface is parallel to the axial direction. The second external tooth main body portion 161 is an end edge of the tooth surface extending from the boundary portion with the second processed portion 162 to the opposite side of the second processed portion 162 in the axial direction. The second external tooth main body portion 161 faces the second reduced diameter portion 32 of the internal tooth pin 3 in the radial direction, and faces the part of the columnar portion 33 of the internal tooth pin 3 in the radial direction. In the axial direction, a part of the second external tooth main body portion 161 is located closer to the first external tooth 14a than the second reduced diameter portion 32 of the internal tooth pin 3. Second external tooth body The length of the axial direction of 161 is longer than the length of the axial direction of the second processed portion 162.

The first processed portion 142 and the second processed portion 162 are provided at positions adjacent to each other in the axial direction. The first processed portion 142 and the second processed portion 162 are respectively provided at the inner end portion of the first outer tooth 14a and the inner end portion of the second outer tooth 16a. In other words, the first processed portion 142 is provided at an end portion on the second outer teeth 16a side of both end portions of the first external teeth 14a in the axial direction. The second processed portion 162 is provided at an end portion on the first outer teeth 14a side of both end portions in the axial direction of the second external teeth 16a.

The first processed portion 142 is processed into a curved portion so that the tooth surface thereof is located radially inward in the axial direction of the second external teeth 16a. In other words, the tooth surface of the first processed portion 142 is processed so as to be located radially inward with the end portion (the edge of the tooth surface) facing the axial direction of the tooth surface. In the present embodiment, the first processed portion 142 is provided integrally with the first outer teeth 14a in the circumferential direction. In other words, the first processed portion 142 is provided on all of the tooth tips and the valley portions arranged in the circumferential direction. The first processed portion 142 faces the part of the columnar portion 33 of the internal tooth pin 3 in the radial direction of the inner tooth pin 3 .

The second processed portion 162 is processed into a curved portion so that the tooth surface thereof is located radially inward in the axial direction on the first external tooth 14a side. In other words, the tooth surface of the second processed portion 162 is processed so as to be located radially inward with the end portion (the edge of the tooth surface) facing the axial direction of the tooth surface. In the present embodiment, the second processed portion 162 is provided integrally with the second outer teeth 16a in the circumferential direction. In other words, the second processed portion 162 is provided on all of the tooth tips and the valley portions arranged in the circumferential direction. The second processed portion 162 faces the portion of the columnar portion 33 of the internal tooth pin 3 in the radial direction of the internal tooth pin 3 .

The first reduced diameter portion 31 and the first processed portion 142 and the second processed portion 162 are not opposed to each other in the radial direction of the internal tooth pin 3 . The second reduced diameter portion 32 and the first processed portion 142 and the second processed portion 162 are not opposed to each other in the radial direction of the internal tooth pin 3 .

In the first processed portion 142 and the second processed portion 162, the machining depth at the top of the tooth and the machining depth at the valley portion may be substantially equal, but the invention is not limited thereto. For example, the machining depth at the top of the tooth may be deeper than the machining depth at the valley portion.

In addition, when the first externally toothed gear 14 swings and rotates, the tip end (the crown) of the first external tooth 14a is adjusted so as to suppress the contact with the internal toothed pin 3, and the amount of protrusion to the outside in the radial direction is adjusted. good. The same applies to the tip end of the tooth at the second external tooth 16a.

(action)

Next, the operation of the gear transmission 1 will be described. First, the rotation is input to the input shaft 8 of the gear transmission 1 by, for example, driving of a motor (not shown). Thereby, the input gear 8a rotates together with the input shaft 8. The rotation of the input gear 8a is transmitted to each of the crankshafts 10 via the respective transmission gears 20.

Then, as the crank shaft 10 rotates, the first eccentric portion 10a and the second eccentric portion 10b of each of the crankshafts 10 are eccentrically rotated. With the eccentric rotation of the first eccentric portion 10a, the first externally toothed gear 14 is oscillated and rotated while meshing with the portion of the cylindrical portion 33 of the internal toothed pin 3 on the side of the first reduced diameter portion 31, and 2 The eccentric rotation of the eccentric portion 10b is interlocked, and the second externally toothed gear 16 is oscillated and rotated while meshing with the portion of the columnar portion 33 of the internal tooth pin 3 on the second reduced diameter portion 32 side. The swinging rotation of the first externally toothed gear 14 and the second externally toothed gear 16 is transmitted to the carrier 4 via each of the crankshafts 10 The body 4 as a whole rotates relative to the outer cylinder 2 at a rotational speed that is decelerated from the input.

<Second embodiment>

Fig. 5 is a cross-sectional view showing the structure of the vicinity of the meshing portion of the internal tooth pin 3 and the externally toothed gears 14, 16 in the gear transmission 1 according to the second embodiment of the present invention. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and their description will be omitted.

As shown in Fig. 5, in the second embodiment, each of the internal tooth pins 3 has a first reduced diameter portion 34 and a second reduced diameter portion 35 located near the center of the axial direction thereof, and is located at a ratio of the first reduced diameter portion 34. The first columnar portion 36 closer to the outer end portion on one side of the axial direction and the second columnar portion 37 located at the outer end portion on the other side of the second reduced diameter portion 35 in the axial direction.

The first columnar portion 36 has a cylindrical shape, and its outer diameter is constant in the axial direction. The second columnar portion 37 has a cylindrical shape, and its outer diameter is constant in the axial direction. The first reduced diameter portion 34 is processed to be reduced in diameter as it goes from the side of the second reduced diameter portion 35 in the axial direction from the boundary of the first columnar portion 36. The second reduced diameter portion 35 is processed to be reduced in diameter as it goes from the boundary with the second columnar portion 37 in the axial direction of the first reduced diameter portion 34 side. The outer peripheral surface of the first reduced diameter portion 34 and the outer peripheral surface of the second reduced diameter portion 35 are curved surfaces that are convex outward. The outer peripheral surface of the first reduced diameter portion 34 and the outer peripheral surface of the second reduced diameter portion 35 are smoothly curved toward the boundary portion of each other. The outer diameter of each internal tooth pin 3 is the smallest boundary portion between the first reduced diameter portion 34 and the second reduced diameter portion 35.

The first processed portion 142 of the first external tooth 14a is provided at an outer end portion on the outer side of the axial direction of the first external tooth 14a. The first processed portion 142 is processed such that its tooth surface is located radially inward as it goes outward on one side in the axial direction. Part. In other words, the tooth surface of the first processed portion 142 is processed so as to be located radially inward with the end portion (the edge of the tooth surface) facing the axial direction of the tooth surface.

The second processed portion 162 of the second external tooth 16a is provided at the outer end portion on the outer side of the other side in the axial direction of the second external tooth 16a. The second processed portion 162 is processed so that the tooth surface is located radially inward of the outer side of the other side in the axial direction. In other words, the tooth surface of the second processed portion 162 is processed so as to be located radially inward with the end portion (the edge of the tooth surface) facing the axial direction of the tooth surface.

The first reduced diameter portion 34 and the first processed portion 142 and the second processed portion 162 are not opposed to each other in the radial direction of the internal tooth pin 3 . The second reduced diameter portion 35 and the first processed portion 142 and the second processed portion 162 are not opposed to each other in the radial direction of the internal tooth pin 3 . The first reduced diameter portion 34 faces the end portion (the inner end portion in the axial direction) where the first processed portion 142 is not provided in the radial direction of the inner tooth pin 3 and the first outer tooth 14a. The second reduced diameter portion 35 faces the end portion (the inner end portion in the axial direction) where the second processed portion 162 is not provided in the radial direction of the inner tooth pin 3 and the second outer tooth 16a.

As described above, in the first and second embodiments, the first processed portion 142 is provided at one end portion of the first external teeth 14a, and the second processed portion 162 is provided at the second external teeth 16a. Set at the end of either side. Further, in each of the internal tooth pins 3, the first reduced diameter portion 31 (34) and the second reduced diameter portion 32 (35) are respectively provided in the radial direction and the end portion where the first processed portion 142 is not provided, and the second portion is not provided. A portion where the end portions of the processed portion 162 face each other. In other words, in order to suppress occurrence of edge stress between the first external teeth 14a and the second external teeth 16a and the internal tooth pins 3, the first external teeth 14a, the second external teeth 16a, and the internal tooth pins 3 are necessary. Processing is applied to the lowest part. For example, in the first embodiment, as an example, in each of the internal tooth pins 3, only the both end portions 31 and 32 are applied. The processing is performed, and the intermediate portion 33 is not subjected to the ridge processing. Further, the first outer teeth 14a and the second outer teeth 14b are embossed only at the end portions adjacent to each other in the axial direction (the inner end portions of the first outer teeth 14a and the inner end portions of the second outer teeth 16a). . Thereby, it is possible to suppress an increase in processing cost while suppressing generation of edge stress between the first external teeth 14a and the second external teeth 16a and the internal tooth pins 3.

Further, in the first and second embodiments, in addition to the gear transmission described in the seventh embodiment of Patent Document 1, the processing size is simplified, in addition to the halving of the machining portion. Specifically, it is as follows.

In order to obtain the effect of the ridge processing, it is necessary that the trimming amount (the amount of reduction or the amount of recess in the direction of the tooth line) of the tooth intersection direction (the axial direction of the internal pin 3) is within the tolerance. In the gear transmission described in the seventh aspect of Patent Document 1, the raised position of the internal teeth and the raised position of the external teeth are opposed to each other in the radial direction. In this way, in the case where the machining portions are opposed to each other in the radial direction, the machining tolerance of 1/2 of the tolerance of the dressing amount is required for each machining portion. That is, in the case where the machining portions are opposed to each other in the radial direction, the machining tolerance of 1/2 of the machining tolerance required in the raised machining portion of the present embodiment is required for each of the machining portions. In the case where it is impossible to machine the machining tolerance of 1/2 of the tolerance of the trimming amount, it is necessary to increase the tolerance range of the amount of the bulging, and there is a case where the effect of the bulging is reduced.

On the other hand, in the first and second embodiments, the raised position of the internal teeth and the raised position of the external teeth are not opposed to each other in the radial direction. Therefore, the machining tolerance of the first reduced diameter portion 31 (34) or the second reduced diameter portion 32 (35) of the internal tooth pin may be the tolerance of the trimming amount. Also, because the machining tolerances are widened, so It is not necessary to increase the tolerance range of the amount of bulge. In this way, in the first and second embodiments, the machining size management is simplified as compared with the gear transmission described in the seventh embodiment of Patent Document 1.

In the first embodiment, the first processed portion 142 is provided at an end portion on the second external teeth 16a side of the axial end portions of the first external teeth 14a, and the second processed portion 162 is provided at the second external teeth 16a. The end portion on the first outer tooth 14a side of the axial end portions, the first reduced diameter portion 31 is provided at one end portion of each of the inner tooth pins 3 in the axial direction, and the second reduced diameter portion 32 is provided at each inner tooth The other end of the axial direction of the pin 3.

In the present configuration, the reduced diameter portions 31 and 32 are provided at both end portions in the axial direction of each of the internal tooth pins 3, and compared with the case where the reduced diameter portions 34 and 35 are provided in the axially intermediate portion as in the second embodiment. Processing becomes easier. Thereby, the processing cost can be reduced more effectively.

The embodiments of the present invention have been described above, but the present invention is not limited to the embodiments, and various modifications and improvements can be made without departing from the scope of the invention.

For example, in the above-described embodiment, the outer peripheral surface (tooth surface) of the first reduced diameter portion and the second reduced diameter portion is a curved shape that is convex outward, but the present invention is not limited thereto. The outer peripheral surface of the first reduced diameter portion and the second reduced diameter portion may be, for example, a truncated cone shape or the like.

In addition, in the above-described embodiment, the tooth surface of the first processed portion 142 and the second processed portion 162 is processed into a curved portion so as to be radially inward toward the axial end portion. But this is not limited. The tooth surfaces of the first processed portion 142 and the second processed portion 162 may be, for example, The cross section (the cross section parallel to the axial direction) shown in Fig. 3 is an inclined surface inclined to the axial direction at an angle of, for example, an acute angle.

Further, in the above-described embodiment, the case where the input shaft 8 is provided at the center of the radial direction is exemplified, but the present invention is not limited thereto. The input shaft 8 can also be disposed at a position that is radially offset from the center.

Further, in the above-described embodiment, a case where a plurality of (for example, three) crankshafts are provided is exemplified. However, for example, one crankshaft may be provided at the center of the radial direction. In this case, a configuration in which the cylindrical body is fitted into the through hole 4d, the through hole 4f, the through hole 14b, and the through hole 16b may be employed. In the cylinder, for example, a cable or the like is disposed.

In the above embodiment, the carrier is relatively rotated about the outer cylinder. That is, it may be a form in which the carrier is fixed, and the outer cylinder is relatively rotated with respect to the carrier, or may be a form in which the outer cylinder is fixed and the carrier is relatively rotated toward the outer cylinder.

Further, the above specific embodiments will be briefly described.

The gear transmission includes: an outer cylinder having inner circumferential surfaces of a plurality of pin grooves extending in the axial direction at a predetermined interval; a plurality of internal tooth pins disposed in each of the plurality of pin grooves; The crankshaft has a first eccentric portion and a second eccentric portion that are arranged in the axial direction with a predetermined phase difference, and is provided to be rotatable about the shaft in the outer cylinder; the first externally toothed gear is The outer peripheral surface provided with the first outer teeth is attached to the first eccentric portion, and the first outer teeth are meshed with the inner eccentric pin so as to rotate in conjunction with the eccentric rotation of the first eccentric portion; The second externally toothed gear has an outer peripheral surface on which the second external tooth is provided, and is attached to the second eccentric portion, and the second external tooth meshes with the internal toothed pin to interlock with the eccentric rotation of the second eccentric portion. The oscillating rotation is performed; and the carrier is conveyed by the oscillating rotation of the first externally toothed gear and the second externally toothed gear, and the outer cylinder is relatively rotated.

The first external tooth system has a first processed portion at one of the axial ends. The tooth surface of the first processed portion is processed to be located radially inward with the end portion in the axial direction of the tooth surface. The second external tooth system has a second processed portion at one of the axial ends. The tooth surface of the second processed portion is processed to be located radially inward with the end portion in the axial direction of the tooth surface.

Each of the internal tooth pins has a first reduced diameter portion and a second reduced diameter portion. The first reduced diameter portion is processed such that a portion that faces in the radial direction and an end portion of the first external tooth on the side where the first processed portion is not provided is reduced in diameter in the axial direction. The second reduced diameter portion is processed to be reduced in diameter in the axial direction at a portion facing the end portion of the second external tooth on the side where the second processed portion is not provided.

In this configuration, the first processed portion is provided at one end of the first external tooth, and the second processed portion is provided at one end of the second external tooth. Further, in each of the internal tooth pins, the first reduced diameter portion and the second reduced diameter portion are respectively provided in a portion facing the end portion where the first processed portion is not provided and the end portion where the second processed portion is not provided. In other words, in order to suppress occurrence of edge stress between the first external teeth and the second external teeth and the internal tooth pins, the first outer teeth, the second external teeth, and the internal tooth pins are required to be the minimum necessary portions. Apply processing. Thereby, it is possible to suppress an increase in processing cost while suppressing occurrence of edge stress between the first external teeth and the second external teeth and the internal tooth pins.

In the gear transmission, the first processing portion is provided on an end portion of the first external tooth on the second external tooth side, and the second processing portion is provided in the first outer one of the second external teeth. The end portion on the tooth side, the first reduced diameter portion is provided at one end portion of the internal tooth pin in the axial direction, and the second reduced diameter portion is provided at the other end portion of the internal tooth pin in the axial direction. .

In this configuration, the reduced diameter portion is provided at both end portions of the inner tooth pin in the axial direction. In the present configuration, since the processing is made simpler than the case where the reduced diameter portion is provided in the axially intermediate portion of the internal tooth pin, the processing cost can be more effectively reduced.

1‧‧‧Gear transmission

2‧‧‧Outer tube

2b‧‧‧ pin slot

3‧‧‧ internal gear

31, 34‧‧‧1st reduced diameter

32, 35‧‧‧2nd reduction section

33‧‧‧ Column

36‧‧‧1st columnar

37‧‧‧2nd columnar

4‧‧‧ Carrier

10‧‧‧ crankshaft

10a‧‧‧1st eccentric

10b‧‧‧2nd eccentric

14‧‧‧1st external gear

14a‧‧‧1st external tooth

141‧‧‧1st external tooth body

142‧‧1 first processing department

16‧‧‧2nd external gear

16a‧‧‧2nd external tooth

161‧‧‧2nd external tooth body

162‧‧‧2nd Processing Department

20‧‧‧Communication gear

Fig. 1 is a cross-sectional view showing a gear transmission according to a first embodiment of the present invention.

Fig. 2 is a cross-sectional view taken along line II-II of Fig. 1.

Fig. 3 is an enlarged cross-sectional view showing the structure in the vicinity of the meshing portion of the internal tooth pin and the external gear of the gear transmission shown in Fig. 1.

Fig. 4 is an enlarged perspective view showing the structure in the vicinity of the meshing portion of the internal gear pin and the external gear of the gear transmission shown in Fig. 1, and is a view showing a part of the configuration.

Fig. 5 is a cross-sectional view showing the structure of the vicinity of the meshing portion of the inner tooth pin and the outer tooth gear, showing the gear transmission device according to the second embodiment of the present invention.

2‧‧‧Outer tube

3‧‧‧ internal gear

4a‧‧‧ base

4b‧‧‧End Plate Department

4c‧‧‧Axis

6‧‧‧ Carrier bearing

14a‧‧‧1st external tooth

16a‧‧‧2nd external tooth

31‧‧‧1st reduced diameter

32‧‧‧2nd reduction section

33‧‧‧ Column

141‧‧‧1st external tooth body

142‧‧1 first processing department

161‧‧‧2nd external tooth body

162‧‧‧2nd Processing Department

Claims (2)

A gear transmission device comprising: an outer cylinder having inner circumferential surfaces of a plurality of pin grooves extending in the axial direction at a predetermined interval; an inner tooth pin disposed in each of the plurality of pin grooves; a crank shaft The first eccentric portion and the second eccentric portion are arranged such that they are arranged in the axial direction with a predetermined phase difference, and are arranged to be rotatable about the shaft in the outer cylinder; the first externally toothed gear has a setting The outer peripheral surface of the first external tooth is attached to the first eccentric portion, and the first external tooth is meshed with the eccentric portion of the first eccentric portion while being meshed with the internal tooth pin; the second external tooth The gear has an outer peripheral surface on which the second external teeth are provided, and is attached to the second eccentric portion, and the second external tooth meshes with the internal tooth pin to swing in a manner to interlock with the eccentric rotation of the second eccentric portion. And the carrier is conveyed by the swinging rotation of the first externally toothed gear and the second externally toothed gear, and the outer cylinder is relatively rotated; the first external tooth is at one end of the axial direction a first processing portion; the tooth surface of the first processing portion is processed to be in the axial direction of the tooth surface The end portion is located radially inward; the second external tooth has a second processed portion at one of the axial ends; the tooth surface of the second processed portion is machined to the axis of the tooth surface Located radially inward of the end; Each of the internal tooth pins has a first reduced diameter portion and a second reduced diameter portion, and the first reduced diameter portion is processed into an end portion of the first external tooth in a radial direction and a side where the first processed portion is not provided. The opposing portion is reduced in diameter in the axial direction; the second reduced diameter portion is processed so as to be opposed to the end portion of the second external tooth on the side where the second processed portion is not provided in the radial direction The axial direction is reduced. The gear transmission according to the first aspect of the invention, wherein the first processing unit is provided at an end of the first external tooth on the second external tooth side; and the second processing unit is provided in the second external portion. An end portion of the first outer tooth side of the tooth; the first reduced diameter portion is provided at one end portion of the inner tooth pin in the axial direction; and the second reduced diameter portion is provided in each inner tooth pin The other end of the axial direction.