CN103890452A - 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

technical field

The invention relates to a gear transmission device.

Background technique

Conventionally, there is known an eccentric oscillating type gear transmission in which an external gear meshed with an internal pin of the internal gear is oscillatingly rotated in conjunction with the eccentric rotation of the eccentric portion of the crankshaft, thereby achieving deceleration relative to the input rotational speed. The output rotation (for example, refer to Patent Document 1).

In the gear transmission described in Patent Document 1, a plurality of internally toothed pins that mesh with two externally toothed gears are provided. Each internal tooth pin has a first engaging portion, a second engaging portion, and a connecting portion connecting the two engaging portions. Both ends in the axial direction of each meshing portion are subjected to drum finishing ( FIG. 3 and FIG. 6 of Patent Document 1). Accordingly, the edge stress generated between the tooth surface of each externally toothed gear and the outer peripheral surfaces of the axially opposite end portions of each meshing portion of the internally toothed pin is reduced. In addition, in FIG. 7 of Patent Document 1, not only the inner tooth pin but also the tooth surfaces at both end portions of each external gear are given crown dressing. According to this, the edge stress generated between the tooth surfaces of the both ends of each externally toothed gear and the outer peripheral surfaces of the axially opposite ends of the respective meshing portions of the internally toothed pins is further reduced.

However, in the gear transmission shown in FIG. 3 and FIG. 6 of Patent Document 1, it is necessary to carry out drum-shaped finishing processing on both ends of the first meshing part in each internal gear pin, and to carry out drum-shaped finishing processing on both ends of the second meshing part. There is a problem that the cost increases due to the process of performing crowning processing on the part and connecting the two meshing parts through the connecting part. Furthermore, as shown in FIG. 7 of Patent Document 1, when both ends of each externally toothed gear are crowned, the man-hours required for the crowning process increase and the cost increases.

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open Publication No. 2009-293650

Contents of the invention

An object of the present invention is to provide a gear transmission capable of suppressing edge stress between an externally toothed gear and an internally toothed pin, and suppressing an increase in cost.

The gear transmission device of the present invention includes: an outer cylinder having an inner peripheral surface, on which a plurality of pin grooves extending in the axial direction are arranged at predetermined intervals along the circumferential direction; inner tooth pins arranged on the inner peripheral surface In each of the plurality of pin grooves; a crankshaft having a first eccentric portion and a second eccentric portion arranged in alignment with each other in the axial direction with a specified phase difference, and is arranged so as to be able to rotate about the axis in the outer cylinder. The center rotates; the first external tooth gear has an outer peripheral surface provided with first external teeth, and is installed on the first eccentric part, and the first external tooth gear makes the first external teeth and the internal teeth The pin meshes with the eccentric rotation of the first eccentric part to swing and rotate; the second external tooth gear has an outer peripheral surface provided with second external teeth and is installed on the second eccentric part. The externally toothed gear swings and rotates in conjunction with the eccentric rotation of the second eccentric portion while the second externally toothed gear meshes with the internally toothed pin; The swinging rotation of the second externally toothed gear is transmitted to rotate relative to the outer cylinder.

The first external tooth has a first processed portion at any one end in the axial direction. The tooth surface of the first processed portion is processed so that an axial end portion closer to the tooth surface is located radially inward. The second external tooth has a second processed portion at any one end in the axial direction. The tooth surface of the second processed portion is processed so that an axial end portion closer to the tooth surface is located radially inward.

Each internal tooth pin has a first diameter reduction portion and a second diameter reduction portion. The first reduced-diameter portion is processed such that a portion facing the end portion of the first external tooth on a side not provided with the first processed portion in the radial direction decreases in diameter toward the axial direction. The second reduced-diameter portion is processed such that a portion facing the end portion of the second external tooth on a side not provided with the second processed portion in the radial direction decreases in diameter toward the axial direction.

Description of drawings

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

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

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

4 is an enlarged perspective view for explaining a structure near a meshing portion of an internal pin and an external gear in the gear transmission shown in FIG. 1 , and is a partially cutaway view of the structure.

5 shows a gear transmission according to a second embodiment of the present invention, and is an enlarged cross-sectional view showing a structure near a meshing portion of an internal pin and an external gear.

Detailed ways

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

<First Embodiment>

(The overall structure of the gear transmission)

In the gear transmission 1 according to the first embodiment, the first externally toothed gear 14 is oscillatingly rotated in conjunction with the first eccentric portion 10 a of the crankshaft 10 , and the second externally toothed gear 16 is connected to the second eccentric portion of the crankshaft 10 . 10b is interlocked to swing and rotate, thereby obtaining an output rotation decelerated with respect to the input rotation speed.

As shown in Figure 1, the gear transmission device 1 includes an outer cylinder 2, a plurality of inner tooth pins 3, a support 4, an input shaft 8, a plurality (for example, 3) crankshafts 10, a first outer gear 14, a second outer toothed gear 16 and a plurality (eg 3) of transfer gears 20 .

As shown in FIG. 2 , the outer cylinder 2 is a member constituting 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 peripheral surface of the outer cylinder 2 . Each pin groove 2b extends in the axial direction of the outer cylinder 2, and has a semicircular cross-sectional shape in a cross-section perpendicular to the axial direction. These pin grooves 2 b are arranged at equal intervals in the circumferential direction on the inner peripheral surface of the outer cylinder 2 .

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

As shown in FIG. 1 , the holder 4 is accommodated in the outer cylinder 2 in a state of being arranged coaxially with the outer cylinder 2 . The base 4 rotates about the same axis with respect to the outer cylinder 2 . Specifically, the holder 4 is supported so as to be rotatable relative to the outer cylinder 2 by a pair of holder bearings 6 provided so as to be spaced apart from each other in the axial direction. In the present embodiment, the holder 4 includes a base portion 4 a, an end plate portion 4 b, and a plurality (for example, three) of shaft portions 4 c. However, it is not limited to this structure.

The base portion 4 a is disposed on one end side of the outer cylinder 2 in the axial direction within the outer cylinder 2 . A circular through-hole 4d is formed in the radial center portion of the base portion 4a. Around the through hole 4d, 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.

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

The three shaft parts 4c are provided integrally with the base part 4a, and extend linearly from the base part 4a toward the end plate part 4b side. These three shaft portions 4 c are arranged at equal intervals in the circumferential direction (see FIG. 2 ). Each shaft part 4c is fastened to the end plate part 4b by the bolt 4h (refer FIG. 1). Thereby, the base part 4a, the shaft part 4c, and the end plate part 4b are integrated.

The input shaft 8 functions as an input unit, and rotation is input to the input unit 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 axes of the outer cylinder 2 and the holder 4 . The input shaft 8 rotates about its axis. An input gear 8 a is provided on the outer peripheral surface of the front end portion of the input shaft 8 .

Three crankshafts 10 are arranged at equal intervals around the input shaft 8 in the outer cylinder 2 (see FIG. 2 ). Each crankshaft 10 is attached to the corresponding attachment hole 4e of the base portion 4a and the attachment hole 4g of the end plate portion 4b (see FIG. 1 ). Specifically, an axially inner portion of a predetermined length from one axial end of each crankshaft 10 is mounted in the mounting hole 4e of the base 4a via the first crankshaft bearing 12a. On the other hand, the other end portion in the axial direction of each crankshaft 10 is mounted in the mounting hole 4g of the end plate portion 4b via the second crank bearing 12b. Each crankshaft 10 is supported by two crankshaft bearings 12a and 12b so as to be rotatable about its axis relative to the carrier 4 .

Each crankshaft 10 has a first eccentric portion 10a and a second eccentric portion 10b arranged axially between portions supported by two crankshaft bearings 12a, 12b. The first eccentric portion 10a and the second eccentric portion 10b each have a cylindrical shape. The first eccentric portion 10a and the second eccentric portion 10b are each eccentric from the axis of the crankshaft 10 by a predetermined amount of eccentricity, and are arranged to have a predetermined angular phase difference from each other. In addition, at one end of the crankshaft 10 , that is, at an axially outer portion than a portion mounted in the mounting hole 4 e of the base 4 a , a fitted portion 10 c for mounting the transmission gear 20 is provided.

As shown in FIGS. 1 and 2 , the first externally toothed gear 14 is arranged in the closed space inside the outer cylinder 2 . The first externally toothed gear 14 is attached to the first eccentric portion 10a of each crankshaft 10 via a first roller bearing 18a. When each crankshaft 10 rotates and the first eccentric portion 10 a rotates eccentrically, the first externally toothed gear 14 is oscillatingly rotated while meshing with the internally toothed pin 3 in conjunction with the eccentrically rotated.

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

As shown in FIG. 2 , the central portion through hole 14 b is provided in the radially central portion of the first externally toothed gear 14 . The input shaft 8 is inserted into the center through-hole 14b with play.

Three first eccentric portion insertion holes 14 c are provided around the central portion through hole 14 b at equal intervals in the circumferential direction of the first external gear 14 . The first eccentric portion 10a of the corresponding crankshaft 10 is inserted into each of the first eccentric portion insertion holes 14c in a state where the first roller bearing 18a is attached.

Three shaft portion insertion holes 14 d are provided at equal intervals in the circumferential direction around the central portion through hole 14 b in the first externally toothed gear 14 . Each shaft portion insertion hole 14d is arranged 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 shaft portion insertion hole 14d with play. The detailed structure of the first external teeth 14a will be described later.

The second externally toothed gear 16 is disposed in the closed space inside the outer cylinder 2 . The second externally toothed gear 16 is attached to the second eccentric portion 10b of each crankshaft 10 via a second roller bearing 18b. The first externally toothed gear 14 and the second externally toothed gear 16 are aligned in the axial direction corresponding to the arrangement of the first eccentric portion 10a and the second eccentric portion 10b. When each crankshaft 10 rotates and the second eccentric portion 10 b rotates eccentrically, the second externally toothed gear 16 is oscillatingly rotated while meshing with the internally toothed pin 3 in conjunction with the eccentrically rotated.

The second externally toothed gear 16 has a size slightly smaller than the inner diameter of the outer cylinder 2 . In the present embodiment, the second externally toothed gear 16 has second external teeth 16a, a central portion through hole 16b, a plurality (for example, three) of second eccentric portion insertion holes 16c, and a plurality (for example, three) of shaft portions. Insertion hole 16d. However, it is not limited to this structure. These have the same structure as the 1st external tooth 14a of the 1st external gear 14, the center part penetration hole 14b, the some 1st eccentric part insertion hole 14c, and the some shaft part insertion hole 14d. The second eccentric portion 10b of the corresponding crankshaft 10 is inserted into each second eccentric portion insertion hole 16c in a state where the second roller bearing 18b is attached. The detailed structure of the second external teeth 16a will be described later.

Each transmission gear 20 transmits the rotation of the input gear 8 a to the corresponding crankshaft 10 . Each transmission gear 20 is externally fitted to a fitted portion 10 c provided at one end portion of the corresponding crankshaft 10 . Each transmission gear 20 rotates integrally with the crankshaft 10 around the same axis as the rotation axis of the crankshaft 10 . Each transmission gear 20 has external teeth 20a meshing with the input gear 8a.

(Structure of internal tooth pin)

As shown in FIGS. 2 to 4 , each internal tooth pin 3 has a substantially cylindrical shape. Each internal tooth pin 3 is formed by cutting and/or grinding one rod-shaped metal member. In the present embodiment, the outer peripheral surface of each inner tooth pin 3 is subjected to crowning processing by cutting and/or grinding. Accordingly, the outer diameters of the axially opposite end portions of each internally toothed pin 3 are smaller than the outer diameters of the portions between these end portions. Specifically, it is as follows.

Each internally toothed pin 3 has: a first reduced diameter portion 31 located at one of its axial end portions; a second reduced diameter portion 32 located at the other axial end portion; The columnar part (middle part) 33 . In each internally toothed pin 3 , the first diameter-reduced portion 31 , the columnar portion 33 and the second diameter-reduced portion 32 are arranged in sequence along the axial direction and integrally formed. The cross sections perpendicular to the axial direction of the first diameter reducing portion 31 , the second diameter reducing portion 32 and the columnar portion 33 are circular.

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 approaches one of the end edges 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 approaches the other end edge in the axial direction. Therefore, in each inner tooth pin 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 protruding outward. The outer peripheral surfaces of the first reduced diameter portion 31 and the second reduced diameter portion 32 are smoothly curved at their respective end edges.

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 FIGS. 3 and 4 , the portion on the side of the first diameter-reduced portion 31 from the vicinity of the axial center of the columnar portion 33 is provided on the first external teeth 14 a of the first external tooth gear 14 . The positions facing each other in the radial direction, and the first external teeth 14a mesh with this position. On the other hand, the portion on the side of the second diameter-reduced portion 32 from the vicinity of the center in the axial direction of the columnar portion 33 is provided at a position facing the second external teeth 16a of the second external tooth gear 16 in the radial direction, and the second The two external teeth 16a are engaged with this part.

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

(structure of external teeth)

As shown in FIG. 2 , the first external teeth 14 a are provided on the outer peripheral surface of the first externally toothed gear 14 . The tooth surface of the first external tooth 14 a has a smooth and continuous wave shape in the entire circumferential direction on a section perpendicular to the axial direction (the section shown in FIG. 2 ). That is, the tooth surfaces of the first external teeth 14a are alternately arranged in the circumferential direction with tops on the outer side in the radial direction and bottoms on the inner side in the radial direction.

Each top and each bottom are substantially arc-shaped on a section perpendicular to the axial direction. The plurality of tops and the plurality of bottoms form a smooth curved surface as a whole. Here, the boundary between the top and the bottom adjacent to each other is the tooth surface in the middle between the top (peak) of the outermost top and the bottom of the innermost bottom in the radial direction of the first externally toothed gear 14 position on the

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

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

The first external tooth body portion 141 is a portion whose tooth surface is parallel to the axial direction. The first external tooth body portion 141 extends from a boundary portion with the first processed portion 142 to an end edge of the tooth surface on the opposite side of the first processed portion 142 in the axial direction. The first external tooth body portion 141 faces the first diameter-reduced portion 31 of the internal tooth pin 3 in the radial direction, and faces a part of the columnar portion 33 of the internal tooth pin 3 in the radial direction. A part of the first external teeth main body portion 141 is located on the side of the second external teeth 16 a from the first reduced diameter portion 31 of the internal tooth pin 3 in the axial direction. The axial length of the first external teeth body portion 141 is greater 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 body portion 161 extends from a boundary portion with the second processed portion 162 to an end edge of the tooth surface on the opposite side of the second processed portion 162 in the axial direction. The second external tooth main body portion 161 faces the second diameter-reduced portion 32 of the internal tooth pin 3 in the radial direction, and faces a 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 teeth main body portion 161 is located on the side of the first external teeth 14 a from the second reduced diameter portion 32 of the internal tooth pin 3 . The axial length of the second external teeth body portion 161 is greater than the axial length of the second processed portion 162 .

The first processed portion 142 and the second processed portion 162 are disposed at positions adjacent to each other in the axial direction. The first processed portion 142 and the second processed portion 162 are respectively provided on the inner end portion of the first external tooth 14a and the inner end portion of the second external tooth 16a. That is, the first processed portion 142 is provided on the end portion on the second external tooth 16a side among the axial end portions of the first external tooth 14a. The second processed portion 162 is provided on the end portion on the side of the first external tooth 14 a among the axial end portions of the second external tooth 16 a.

The first processed portion 142 is a portion processed into a curved shape so that the tooth surface is closer to the second external tooth 16 a side in the axial direction, so that it is located radially inward. That is, the tooth surface of the first processed portion 142 is processed so that the axial end portion (end edge of the tooth surface) of the tooth surface is closer to the radially inner side. In the present embodiment, the first processed portion 142 is provided over the entire circumferential direction of the first external teeth 14a. That is, the first processed part 142 is provided on all tops and bottoms arranged in the circumferential direction. The first processed portion 142 faces a part of the columnar portion 33 of the inner tooth pin 3 in the radial direction of the inner tooth pin 3 .

The second processed portion 162 is a portion processed into a curved shape so that the side of the first external tooth 14a in the axial direction is located so that the tooth surface is located radially inward. That is, the tooth surface of the second processed portion 162 is processed so that the closer to the axial end portion (end edge of the tooth surface) of the tooth surface is, the more radially inward it is. In the present embodiment, the second processed portion 162 is provided over the entire circumferential direction of the second external teeth 16a. That is, the second processed portion 162 is provided on all tops and bottoms arranged in the circumferential direction. The second processed portion 162 faces a part of the columnar portion 33 of the inner tooth pin 3 in the radial direction of the inner tooth pin 3 .

The first reduced diameter portion 31 is not opposed to the first processed portion 142 and the second processed portion 162 in the radial direction of the inner gear pin 3 . The second reduced diameter portion 32 is not opposed to the first processed portion 142 and the second processed portion 162 in the radial direction of the inner gear pin 3 .

In the first processing part 142 and the second processing part 162, the processing depth of the top part and the processing depth of the bottom part may be about the same level, but it is not limited thereto. For example, it is also possible to make the processing depth of the top larger than that of the bottom.

In addition, it is preferable that the protrusion amount of the top end (peak) of the top of the first external teeth 14 a is adjusted radially outward so as to suppress contact with the internal tooth pin 3 when the first external tooth gear 14 swings and rotates. The same applies to the tip of the tip of the second external tooth 16a.

(action)

Next, the operation of the gear transmission 1 will be described. First, rotation is input to the input shaft 8 of the gear transmission 1 , for example, by driving a motor not shown in the figure. Accordingly, the input gear 8 a rotates together with the input shaft 8 . The rotation of this input gear 8 a is transmitted to each crankshaft 10 through each transmission gear 20 .

Next, as each crankshaft 10 rotates, the first eccentric portion 10 a and the second eccentric portion 10 b of each crankshaft 10 rotate eccentrically. Accordingly, in conjunction with the eccentric rotation of the first eccentric portion 10a, the first externally toothed gear 14 oscillates and rotates while meshing with the portion of the cylindrical portion 33 of the internally toothed pin 3 on the side of the first diameter-reduced portion 31 , and, In conjunction with the eccentric rotation of the second eccentric portion 10b, the second externally toothed gear 16 swings and rotates while meshing with a portion of the columnar portion 33 of the internally toothed pin 3 on the side of the second diameter-reduced portion 32 . The swinging rotation of the first externally toothed gear 14 and the second externally toothed gear 16 is transmitted to the base 4 through each crankshaft 10 , and the entire base 4 rotates relative to the outer cylinder 2 at a rotational speed decelerated from the input rotation.

<Second Embodiment>

5 shows a gear transmission 1 according to a second embodiment of the present invention, and is an enlarged cross-sectional view showing the structure near the meshing portion of the internal pin 3 and the external gears 14 and 16 . In addition, in the following description, the same code|symbol as 1st Embodiment is attached|subjected to the same structure as 1st Embodiment, and description is abbreviate|omitted.

As shown in FIG. 5 , in the second embodiment, each internally toothed pin 3 has: a first reduced diameter portion 34 and a second reduced diameter portion 35 located near the center in the axial direction; The first columnar portion 36 is located at one of the axially outer end portions; and the second columnar portion 37 is located at the other axially outer end portion than the second diameter-reduced portion 35 .

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 so as to decrease in diameter from the boundary with the first columnar portion 36 toward the second reduced diameter portion 35 in the axial direction. The second reduced diameter portion 35 is processed so as to decrease in diameter from the boundary with the second columnar portion 37 toward the first reduced diameter portion 34 side in the axial direction. 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 protruding 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 at their boundary portions. The outer diameter of each internally toothed pin 3 is smallest at the boundary portion between the first diameter reducing portion 34 and the second diameter reducing portion 35 .

The first processed portion 142 of the first external tooth 14a is provided at an outer end portion located outside one of the first external teeth 14a in the axial direction. The first processed portion 142 is a portion processed so that the outer side of one of the tooth surfaces closer to the axial direction is located radially inward. That is, the tooth surface of the first processed portion 142 is processed so that the axial end portion (end edge of the tooth surface) of the tooth surface is closer to the radially inner side.

The second processed portion 162 of the second external tooth 16a is provided at the outer end portion located on the other outer side in the axial direction in the second external tooth 16a. The second processed portion 162 is a portion processed so that the tooth surface thereof is located radially inward as it gets closer to the other outer side in the axial direction. That is, the tooth surface of the second processed portion 162 is processed so that the closer to the axial end portion (end edge of the tooth surface) of the tooth surface is, the more radially inward it is.

The first reduced diameter portion 34 is not opposed to the first processed portion 142 and the second processed portion 162 in the radial direction of the inner gear pin 3 . The second reduced diameter portion 35 is not opposed to the first processed portion 142 and the second processed portion 162 in the radial direction of the inner gear pin 3 . The first reduced-diameter portion 34 faces an end portion of the first external tooth 14 a not provided with the first processed portion 142 (inner end portion in the axial direction) in the radial direction of the inner tooth pin 3 . The second reduced-diameter portion 35 faces the end portion (the inner end portion in the axial direction) of the second external tooth 16 a not provided with the second processed portion 162 in the radial direction of the inner tooth pin 3 .

As described above, in the first and second embodiments, any one end portion of the first external tooth 14a is provided with the first processed portion 142, and any one end portion of the second external tooth 16a is provided with the second processing portion. processing part 162. In addition, in each internally toothed pin 3, a first reduced diameter portion 31 ( 34) and the second reduced diameter portion 32 (35). That is, in order to suppress the generation of edge stress between the first external teeth 14a, the second external teeth 16a, and the respective internal tooth pins 3, in the first external teeth 14a, the second external teeth 16a, and the respective internal tooth pins 3, all Minimal parts are required for processing. For example, taking the first embodiment as an example to describe in detail, in each internal gear pin 3 , only the both end portions 31 and 32 are subjected to the crowning process, and the middle portion 33 is not subjected to the crowning process. In addition, among the first external teeth 14a and the second external teeth 14b, only the ends adjacent to each other in the axial direction (the inner end of the first external teeth 14a and the inner end of the second external teeth 16a) are given Drum finishing processing. Accordingly, it is possible to suppress the generation of edge stress between the first external teeth 14 a and the second external teeth 16 a and the respective internal tooth pins 3 , and to suppress an increase in processing costs.

In addition, in the first and second embodiments, compared with the gear transmission described in FIG. 7 of Patent Document 1, in addition to the advantage of reducing the number of processed parts by half, there is also an advantage of easy processing dimension management. Specifically, it is as follows.

In order to obtain the effect of crown trimming, it is necessary to make the amount of trimming in the direction of the tooth line (the axial direction of the inner tooth pin 3 ) (the amount of protrusion or depression in the direction of the tooth line) within the tolerance. In the gear transmission described in FIG. 7 of Patent Document 1, the crowning processing position of the internal tooth pin and the crowning processing position of the external tooth are opposed to each other in the radial direction. When there are such processing locations facing each other in the radial direction, a processing tolerance of 1/2 of the tolerance of the above-mentioned correction amount is required for each processing location. That is, when there are processing portions facing each other in the radial direction, a processing tolerance of 1/2 of the processing tolerance required for the drum truing processing portion in the present embodiment is required for each processing portion. If it is not possible to process with a processing tolerance of 1/2 of the tolerance of the above-mentioned correction amount, it is necessary to expand the tolerance range of the amount of drum trimming, which sometimes reduces the effect of drum trimming.

On the other hand, in the first and second embodiments, the crowning processing position of the internal tooth pin and the crowning processing position of the external tooth pin do not face each other in the radial direction. Therefore, the processing tolerance of the first diameter-reduced portion 31 ( 34 ) and the second diameter-reduced portion 32 ( 35 ) in the inner tooth pin may be the tolerance of the above-mentioned correction amount. Moreover, due to the large machining tolerance, there is no need to expand the tolerance range of the drum dressing amount. Therefore, in the first and second embodiments, compared with the gear transmission described in FIG. 7 of Patent Document 1, there is an advantage that program management of machining is easier.

In the first embodiment, the first processed portion 142 is provided at the end portion on the side of the second external tooth 16a among the axial end portions of the first external tooth 14a, and the second processed portion 162 is provided at the end portion of the second external tooth 16a. At the ends on the side of the first external teeth 14a among the two ends in the axial direction, the first diameter-reducing portion 31 is provided on one of the ends in the axial direction of each inner-tooth pin 3 , and the second diameter-reduction portion 32 is provided on each inner-tooth pin. 3 at the other axial end.

In this structure, diameter-reduced portions 31, 32 are provided at both ends in the axial direction of each internally toothed pin 3. Compared with the case where the diameter-reduced portions 34, 35 are provided at the middle portion in the axial direction of the second embodiment, the Simpler. According to this, the processing cost can be reduced more effectively.

As mentioned above, although embodiment of this invention was described, this invention is not limited to these embodiment, Various changes, improvement, etc. are possible in the range which does not deviate from the summary.

For example, in the above-mentioned embodiment, the case where the outer peripheral surfaces (tooth surfaces) of the first diameter-reducing portion and the second diameter-reduction portion have a curved shape protruding outward is illustrated, but the present invention is not limited thereto. The outer peripheral surfaces of the first reduced diameter portion and the second reduced diameter portion may be, for example, in the shape of a truncated cone.

In addition, in the above-described embodiment, the case where the tooth surfaces of the first processed portion 142 and the second processed portion 162 are processed into a curved shape so as to be located radially inward as they get closer to the axial ends is illustrated, but It is not limited to this. The tooth surfaces of the first processed portion 142 and the second processed portion 162 may be, for example, inclined surfaces inclined at an acute angle with respect to the axial direction on a cross section (a cross section parallel to the axial direction) shown in FIG. 3 .

In addition, in the said embodiment, the case where the input shaft 8 was provided in the radial center was illustrated, but it is not limited to this. The input shaft 8 may also be provided at a position offset radially from the center.

In addition, in the above-mentioned embodiment, the case where a plurality of (for example, three) crankshafts are provided was exemplified, but a configuration in which, for example, one crankshaft is provided at the center in the radial direction may also be employed. In this case, a structure 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 can be adopted. For example, cables and the like are disposed in the cylinder.

In the described embodiment, the mount rotates relative to the tub. That is, a structure in which the base is fixed and the outer cylinder is rotated relative to the base may be employed, or a structure in which the base is fixed and the base is rotated relative to the outer cylinder may be employed.

In addition, the specific embodiments described above will be outlined.

The gear transmission device includes: an outer cylinder having an inner peripheral surface, on which a plurality of pin slots extending in the axial direction are arranged at predetermined intervals along the circumferential direction; inner tooth pins are arranged in the plurality of pin slots In each of the above; a crankshaft having a first eccentric portion and a second eccentric portion arranged in alignment with each other in the axial direction with a specified phase difference, and is arranged to be rotatable centering on the shaft inside the outer cylinder; An externally toothed gear having an outer peripheral surface provided with first external teeth and mounted on the first eccentric portion, the first externally toothed gear engages the first external teeth with the internally toothed pins while Linked with the eccentric rotation of the first eccentric part to swing and rotate; the second external tooth gear has an outer peripheral surface provided with second external teeth and is installed on the second eccentric part, and one side of the second external tooth gear The second external tooth is meshed with the internal tooth pin to swing and rotate in conjunction with the eccentric rotation of the second eccentric part; and the support is passed through the first external tooth gear and the second external tooth The swinging rotation of the gear is transmitted, rotating relative to the outer cylinder.

The first external tooth has a first processed portion at any one end in the axial direction. The tooth surface of the first processed portion is processed so that an axial end portion closer to the tooth surface is located radially inward. The second external tooth has a second processed portion at any one end in the axial direction. The tooth surface of the second processed portion is processed so that an axial end portion closer to the tooth surface is located radially inward.

Each internal tooth pin has a first diameter reduction portion and a second diameter reduction portion. The first reduced-diameter portion is processed such that a portion facing the end portion of the first external tooth on a side not provided with the first processed portion in the radial direction decreases in diameter toward the axial direction. The second reduced-diameter portion is processed such that a portion facing the end portion of the second external tooth on a side not provided with the second processed portion in the radial direction decreases in diameter toward the axial direction.

In this structure, the first processed portion is provided at any one end of the first external tooth, and the second processed portion is provided at any one end of the second external tooth. In addition, in each internally toothed pin, a first reduced-diameter portion and a second diameter-reduced portion are respectively provided at positions facing the end portion not provided with the first processed portion and the end portion not provided with the second processed portion in the radial direction. Reduced diameter. That is, in order to suppress the generation of edge stress between the first external teeth, the second external teeth, and the respective internal tooth pins, the required minimum parts are processed. Accordingly, it is possible to suppress the generation of edge stress between the first external teeth and the second external teeth and the respective internal tooth pins, and to suppress an increase in processing cost.

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

In this configuration, diameter-reduced portions are provided at both axial ends of each inner tooth pin. According to this structure, compared with the case where the diameter-reduced part is provided in the axially intermediate part of an internal tooth pin, machining is simpler, Therefore, a machining cost can be reduced more effectively.

Symbol Description

1 gear transmission

2 outer cylinder

2b Pin slot

3 Internal tooth pin

31, 34 The first reduced diameter part

32, 35 Second diameter reduction part

33 columnar part

36 The first columnar part

37 Second columnar part

4 support

10 crankshaft

10a The first eccentric part

10b Second eccentric part

14 The first external gear

14a The first outer tooth

141 Main part of the first external tooth

142 The first processing department

16 Second external gear

16a Second external tooth

161 Main part of the second external tooth

162 Second Processing Department

20 Transmission gear

Claims (2)

1. a gear drive, is characterized in that comprising:

Urceolus, has inner peripheral surface, is provided with multiple cotter ways of extension vertically at this inner peripheral surface along circumferential with appointed interval;

Interior alligator, is disposed in each of described multiple cotter ways;

Bent axle, has the first eccentric part and the second eccentric part that configure along described axially-aligned with the phase difference of specifying each other, and is provided in described urceolus and can centered by axle, rotates;

The first external tooth gear, has the outer circumferential face that is provided with the first external tooth, and is installed in described the first eccentric part, and this first external tooth gear closes described the first external tooth and described internal tooth pin rodent on one side, on one side the swing rotary with the eccentric rotary interlock of described the first eccentric part;

The second external tooth gear, has the outer circumferential face that is provided with the second external tooth, and is installed in described the second eccentric part, and this second external tooth gear closes described the second external tooth and described internal tooth pin rodent on one side, on one side the swing rotary with the eccentric rotary interlock of described the second eccentric part; And

Bearing, is passed by the swing rotary of described the first external tooth gear and described the second external tooth gear, with respect to described urceolus rotation, wherein,

Described the first external tooth has the first processing department in described axial any one of them end,

It is offside in radially inner side that the flank of tooth of described the first processing department is processed to more to approach the axial end portion of this flank of tooth,

Described the second external tooth has the second processing department in described axial any one of them end,

It is offside in radially inner side that the flank of tooth of described the second processing department is processed to more to approach the axial end portion of this flank of tooth,

Each interior alligator has the first diameter reducing part and the second diameter reducing part,

Described the first diameter reducing part be processed to be not provided with described the first processing department a side described the first external tooth end diametrically position in opposite directions along with towards axial and undergauge,

Described the second diameter reducing part be processed to be not provided with described the second processing department a side described the second external tooth end diametrically position in opposite directions along with towards axial and undergauge.

2. gear drive according to claim 1, is characterized in that:

Described the first processing department is arranged on the end of described the second outside flanks in described the first external tooth,

Described the second processing department is arranged on the end of described the first outside flanks in described the second external tooth,

Described the first diameter reducing part is arranged on described one of them the axial end in each interior alligator,

Described the second diameter reducing part is arranged on the described axial the other end in each interior alligator.

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