JP2017044319A - Eccentric oscillation type gear device and industrial robot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an eccentric oscillation type gear device capable of attaining high compactness while maintaining a large transmission capacity.SOLUTION: An eccentric oscillation type gear device G1 comprises a casing 10, a carrier 20 rotating relatively to the casing, an oscillatory gear 30, and a crank shaft 40 rotating the oscillatory gear to oscillate, the crank shaft having a hollow part 40P2 and the carrier having a shaft member 20S to be inserted into the hollow part. The gear device further comprises an outer bearing 72 arranged between an outer periphery of the crank shaft and an inner periphery of the carrier, and an inner bearing 74 arranged between an inner periphery of the crank shaft and an outer periphery of the shaft member.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an eccentric oscillating gear device and an industrial robot incorporating the gear device.

  Patent Document 1 discloses an eccentric oscillating gear device.

  The eccentric oscillating gear device includes a casing, a carrier that rotates relative to the casing, an oscillating gear, and a crankshaft that oscillates and rotates the oscillating gear.

  The crankshaft has a hollow portion. A shaft member integrated with the carrier is disposed in the hollow portion. The crankshaft is supported by a pair of bearings disposed between the crankshaft and the shaft member. The bearing is composed of a tapered roller bearing.

Japanese Patent No. 5122450 (FIG. 4)

  However, in the case of the gear device having the structure as disclosed in Patent Document 1, it is difficult to secure a large transmission capacity, particularly with respect to the support of the crankshaft. There has been a problem of increasing the size.

  The present invention has been made to solve such a conventional problem, and provides an eccentric oscillating gear device that can achieve compactness while maintaining a large transmission capacity. That is the issue.

  The present invention provides an eccentric oscillating gear device comprising a casing, a carrier that rotates relative to the casing, an oscillating gear, and a crankshaft that oscillates and rotates the oscillating gear. The casing or the carrier has a shaft member inserted into the hollow portion, and the gear device further includes an outer periphery of the crankshaft, an inner periphery of the casing or the carrier, and The above-mentioned problems are solved by comprising an outer bearing disposed between the inner bearing and an inner bearing disposed between the inner periphery of the crankshaft and the outer periphery of the shaft member. .

  In the present invention, the crankshaft has a hollow portion, and the casing or the carrier has a shaft member inserted into the hollow portion. An outer bearing is disposed between the outer periphery of the crankshaft and the inner periphery of the casing or the carrier, and an inner bearing is disposed between the inner periphery of the crankshaft and the outer periphery of the shaft member.

  Thereby, since an outer side bearing can be arrange | positioned on the outer periphery of a crankshaft, transmission capacity can be ensured large. Further, since the inner bearing can be arranged on the inner periphery of the crankshaft, compactness can be realized.

  ADVANTAGE OF THE INVENTION According to this invention, the eccentric rocking | fluctuation type gear apparatus which can implement | achieve compactness can be obtained, maintaining a large transmission capacity.

Sectional drawing which shows the eccentric rocking | fluctuation type gear apparatus which concerns on an example of embodiment of this invention. Sectional drawing which shows the eccentric rocking | fluctuation type gear apparatus which concerns on other embodiment of this invention. Sectional drawing which shows the eccentric rocking | fluctuation type gear apparatus which concerns on other embodiment of this invention. Sectional drawing which shows the example of the industrial robot in which the eccentric rocking | fluctuation type gear apparatus of FIG. 3 was integrated. The principal part expanded sectional view which expands and shows a part of FIG.

  Hereinafter, an example of an embodiment of the present invention will be described in detail based on the drawings.

  FIG. 1 is a cross-sectional view showing an eccentric oscillating gear device G1 according to an example of an embodiment of the present invention.

  The eccentric oscillating gear device G1 oscillates the casing 10, the carrier 20 that rotates relative to the casing 10, an external gear (oscillating gear) 30 whose axis oscillates, and the external gear 30. A crankshaft 40 that is dynamically rotated.

  The crankshaft 40 of the gear device G1 is formed in a cylindrical shape, and is arranged such that its own axis C40 coincides with an axis C50 of an internal gear 50 described later. A tap hole 40T is formed in the axial end 40E of the crankshaft 40. A power input member 52 (in this example, a spur gear) for inputting power from a drive source (for example, a motor) is connected to the crankshaft 40. The power input member 52 is connected by screwing a bolt 53 into the tap hole 40T. That is, the crankshaft 40 constitutes the input shaft of the gear device G1.

  The crankshaft 40 includes two eccentric bodies 54 for swinging the external gear 30. The axis C54 of the eccentric body 54 is eccentric with respect to the axis C40 of the crankshaft 40. The two eccentric bodies 54 are eccentric with a phase difference of 180 ° from each other in order to balance the oscillation of the external gear 30. The configuration related to the support of the crankshaft 40 will be described in detail later.

  An eccentric body bearing 56 is disposed between the eccentric body 54 and the external gear 30. In the gear device G1, the eccentric body bearing 56 is configured by rollers 56C that do not have an inner ring and an outer ring. The rollers 56C are held by a retainer 56R. The external gear 30 is incorporated on the outer periphery of the eccentric body 54 via the rollers 56C. Therefore, the axis C30 of the external gear 30 swings.

The external gear 30 that is a oscillating gear is in mesh with the internal gear 50 that is a non-oscillating gear.
The axis C50 of the internal gear 50 is fixed (does not swing). The internal gear 50 includes an internal gear main body 50A integrated with the casing 10 (first casing body 11 to be described later), and a pin groove 50B formed along the axial direction on the inner periphery of the internal gear main body 50A. And a cylindrical internal pin 50 </ b> C that is rotatably incorporated in the pin groove 50 </ b> B and constitutes the internal tooth of the internal gear 50. The number of internal teeth of the internal gear 50 (the number of internal teeth pins 50C) is slightly larger (only 1 in this example) than the number of external teeth of the external gear 30.

  The carrier 20 is disposed on the axially counter-force input side of the external gear 30. The carrier 20 is a member that rotates relative to the casing 10. The configurations of the casing 10 and the carrier 20 will be described in detail later.

  A main bearing 60 is disposed between the casing 10 and the carrier 20. The main bearing 60 is a bearing that supports the casing 10 and the carrier 20 so as to be relatively rotatable. In the gear device G1, the main bearing 60 includes a cross roller bearing. The main bearing 60 is composed of a rolling surface 60A on the carrier 20 side corresponding to the inner ring, a rolling surface 60B on the casing 10 side corresponding to the outer ring, and rollers 60C that roll on the rolling surfaces 60A and 60B. ing. Since the main bearing 60 is composed of a cross roller bearing, the carrier 20 can be supported in the axial direction and the radial direction with only one main bearing 60.

  On the other hand, a plurality of inner pins 62 penetrates the external gear 30 at a position offset from the axis C30. The external gear 30 has a plurality of inner pin holes 30A through which the inner pins 62 penetrate. Since the inner pin 62 penetrates the external gear 30, it moves in synchronization with the rotation of the external gear 30. The inner pin 62 protrudes integrally from the carrier 20 in a cantilever state.

  In the gear device G1, an inner roller 64 is fitted on the inner pin 62 as a sliding acceleration member. A part of the inner roller 64 is in contact with the inner pin hole 30 </ b> A of the external gear 30. The outer diameter of the inner roller 64 is smaller than the inner diameter of the inner pin hole 30A, and a gap δ30A is secured between the inner roller 64 and the inner pin hole 30A. The swinging component of the external gear 30 is absorbed by the gap δ30A secured between the inner roller 64 and the inner pin hole 30A.

  Here, the structure regarding the support of the crankshaft 40 will be described.

  In brief, the crankshaft 40 of the gear device G1 has a large-diameter hollow portion 40P2. The casing 10 or the carrier 20 (in this example, the carrier 20) integrally includes a shaft member 20S that is inserted into the large-diameter hollow portion 40P2. The gear device G1 includes an outer bearing 72 disposed between the outer periphery 40A of the crankshaft 40 and the inner periphery 20R2 of the casing 10 or the carrier 20 (carrier 20 in this example). Further, the gear device G1 includes an inner bearing 74 disposed between the inner periphery (large-diameter hollow portion 40P2) of the crankshaft 40 and the outer periphery 20S1 of the shaft member 20S.

  This will be described in more detail below.

  As already described, the crankshaft 40 of the gear device G1 is formed in a cylindrical shape as a whole. However, the outer diameter and inner diameter of the crankshaft 40 are not constant.

  The crankshaft 40 has a small-diameter hollow portion 40P1 having a small hollow diameter D40P1 and a large-diameter hollow portion 40P2 having a hollow diameter D40P2 larger than the hollow diameter D40P1 of the small-diameter hollow portion 40P1.

  The small-diameter hollow portion 40P1 is formed on the axial reaction force input side of the crankshaft 40. The large-diameter hollow portion 40P2 is formed on the axial power input side of the crankshaft 40. Both the small-diameter hollow portion 40P1 and the large-diameter hollow portion 40P2 are formed in parallel with the axis C40 of the crankshaft 40.

  The casing 10 of the gear device G1 includes a first casing body 11 integrated with the internal gear main body 50A, a second casing body 12 disposed on the axial direction reaction power input side of the first casing body 11, The first casing body 11 includes a third casing body 13 disposed on the axial power input side.

  The first casing body 11 is located on the radially outer side of the external gear 30 and also serves as the internal gear main body 50A of the internal gear 50 as described above. The 2nd casing body 12 is formed in ring shape, and the rolling surface 60B of the said main bearing 60 is formed in the inner periphery. The 3rd casing body 13 is comprised by the substantially disc shaped member which has 13 A of opening parts in radial direction center, and has covered the axial direction power input side of gear apparatus G1.

  The first casing body 11 is formed with a connecting tap hole 11T. The first casing body 11 and the second casing body 12 are connected by a bolt 15 inserted from the second casing body 12 side being screwed into the connecting tap hole 11T of the first casing body 11. The first casing body 11 and the third casing body 13 are coupled by a bolt (not shown) inserted from the third casing body 13 side being screwed into the coupling tap hole 11T of the first casing body 11. . An O-ring 70 is disposed between the first casing body 11 and the second casing body 12. An O-ring 71 is disposed between the first casing body 11 and the third casing body 13. An oil seal 17 is disposed between the second casing body 12 and the carrier 20.

  With such a configuration, the casing 10 seals the inside of the gear device G1 on the radially outer side of the crankshaft 40. A lubricant is enclosed in the gear device G1.

  The carrier 20 of the gear device G1 includes a disc-shaped flange portion 20F, a ring portion 20R formed integrally and projecting on the outer peripheral portion of the flange portion 20F toward the axial external gear 30, and a flange portion 20F. A shaft member 20S integrally formed on the axial external gear 30 side on the shaft center C20F (= the axis C20R of the ring portion 20R = the axis C40 of the crankshaft 40 = the axis C50 of the internal gear 50). And a plurality of inner pins 62 that are integrally projected to the axial external gear 30 side at a position that is offset from the axis C20F of the flange portion 20F.

  The outer peripheral surface 20R1 of the ring portion 20R of the carrier 20 faces the inner periphery of the second casing body 12 in the radial direction. A rolling surface 60A on the carrier 20 side of the main bearing 60 is formed on the outer peripheral surface 20R1 of the ring portion 20R.

  The shaft member 20S of the carrier 20 is inserted into the large-diameter hollow portion 40P2 of the crankshaft 40. The outer periphery 20S1 of the shaft member 20S faces the large-diameter hollow portion 40P2. Reference numeral 20T denotes a tap hole for connecting a mating member (driven member) (not shown).

  In the gear unit G1 having the crankshaft 40, the casing 10, and the carrier 20 having the above-described configuration, the outer bearing 72 of the gear unit G1 includes the outer periphery 40A at the end of the crankshaft 40 on the side opposite to the axial power input and the carrier. 20 (the ring portion 20R) is disposed between the inner periphery 20R2.

  The outer bearing 72 includes a ball bearing having an inner ring 72A, an outer ring 72B, and a rolling element 72C. Positioning of the outer bearing 72 on the axial direction reaction power input side is performed by contact between an outer ring 72B of the outer bearing 72 and a flange portion 20F (described later) of the carrier 20. Positioning of the outer bearing 72 on the axial power input side is performed by a shoulder 40W1 formed adjacent to the eccentric body 54 via a holding plate 57 of the retainer 56R of the eccentric body bearing 56.

  On the other hand, the inner bearing 74 of the gear device G1 is a shaft member integrated with the carrier 20 and the large-diameter hollow portion 40P2 of the crankshaft 40, that is, the inner periphery of the end portion on the axial power input side of the crankshaft 40. It arrange | positions between the outer periphery 20S1 of 20S.

  The inner bearing 74 is composed of a self-aligning roller bearing having an inner ring 74A, an outer ring 74B, and two sets of roller rows 74C. At the boundary between the small diameter hollow portion 40P1 and the large diameter hollow portion 40P2 of the crankshaft 40, a wall surface 40W2 constituted by a surface perpendicular to the shaft is formed in a ring shape. The wall surface 40W2 constitutes a positioning surface of the inner bearing 74 on the axial reaction force input side. Positioning of the inner bearing 74 on the axial power input side is performed by a retaining ring 75 fitted in the shaft member 20S.

  In the present gear device G1, the eccentric body bearing 56 disposed between the external gear (oscillating gear) 30 and the crankshaft 40 does not overlap with the inner bearing 74 when viewed from the radial direction. The inner bearing 74 is located closer to the axial power input side (non-carrier side) than the eccentric body bearing 56.

  Specifically, in the gear device G1, the shaft member 20S extends from one axial side (reaction power input side) of the external gear 30 to the other side (power input side). The inner bearing 74 is disposed in a portion where the shaft member 20S extends beyond the external gear 30 in the axial direction.

  More specifically, the shaft member 20S extends from one side (reverse power input side) in the axial direction of the casing 10 of the gear device G1 to the other side (power input side). That is, the shaft member 20 </ b> S extends beyond the axial end surface 13 </ b> E of the casing 10 of the gear device G <b> 1 to the outside of the gear device G <b> 1. The inner bearing 74 is disposed in a portion where the shaft member 20S extends to the outside of the gear device G1.

  As described above, in the gear device G1, the power input member 52 (a member to which power from the drive source is input) is coupled to the end 40E on the power input side of the crankshaft 40. The inner bearing 74 overlaps the power input member 52 as viewed from the radial direction. In the present embodiment, the entire inner bearing 74 is disposed inside the large-diameter hollow portion 40P2. However, a part of the inner bearing 74 may be disposed on the inner periphery of the power input member 52. That is, the inner bearing 74 may be disposed across the inner periphery of the large-diameter hollow portion 40P2 and the inner periphery of the power input member 52.

  Further, in the gear device G1, a main bearing 60 that supports the casing 10 and the carrier 20 so as to be relatively rotatable is disposed between the casing 10 and the carrier 20. The main bearing 60 overlaps the outer bearing 72 when viewed from the radial direction. That is, in this gear device G1, the main bearing 60 and the outer bearing 72 are located on substantially the same plane Pc.

  As already described, in the gear device G1, the shaft member 20S is integrated with the carrier 20 (not the casing 10). Further, the outer bearing 72 is disposed between the outer periphery 40A of the crankshaft 40 and the inner periphery 20R2 of the carrier 20 (not the inner periphery of the casing 10).

  In the gear device G <b> 1, the outer bearing 72 is disposed closer to the axial reaction power input side than the inner bearing 74.

  Next, the operation of the eccentric oscillating gear device G1 according to this embodiment will be described.

  First, the operation of the power transmission system of the eccentric oscillating gear device G1 will be described. A power input member 52 is connected to an axial end 40E of the crankshaft 40 (input shaft) via a tap hole 40T and a bolt 53. The crankshaft 40 receives power from the drive source side via the power input member 52 and rotates. When the crankshaft 40 rotates, the eccentric body 54 formed integrally with the crankshaft 40 rotates.

  When the eccentric body 54 rotates, the shaft center C30 of the external gear 30 incorporated in the outer periphery of the eccentric body 54 via the eccentric body bearing 56 swings. The external gear 30 is in mesh with the internal gear 50.

  The number of external teeth of the external gear 30 is one less than the number of internal teeth of the internal gear 50 (the number of internal pins 50C). As a result, the external gear 30 has a difference in the number of teeth (one tooth) with respect to the internal gear 50 that is meshed with the shaft center C30 once every time the crankshaft 40 rotates once. Out of phase and spinning. This rotation component is transmitted to the inner roller 64 and the inner pin 62 penetrating the external gear 30, and the inner pin 62 revolves around the axis C <b> 50 of the internal gear 50.

  Due to the revolution of the inner pin 62, the carrier 20 in which the inner pin 62 is integrated rotates (spins) around the axis C50 of the internal gear 50. The rotation of the carrier 20 drives the mating member (driven member) connected to the carrier 20 by utilizing the tap hole 20T.

  Here, in the gear device G1 according to the present embodiment, the crankshaft 40 has a hollow portion (large-diameter hollow portion 40P2), and the casing 10 or the carrier 20 (the carrier 20 in this example) has the large-diameter hollow portion. The shaft member 20S inserted into the portion 40P2 is integrally provided. An outer bearing 72 is disposed between the outer periphery 40A of the crankshaft 40 and the inner periphery 20R2 of the carrier 20, and between the inner periphery (large-diameter hollow portion 40P2) of the crankshaft 40 and the outer periphery 20S1 of the shaft member 20S. An inner bearing 74 is arranged.

  Therefore, since the outer bearing 72 can be disposed on the “outer periphery” of the crankshaft 40, the outer diameter of the outer bearing 72 can be set large. For example, in the present gear device G1, the inner diameter D72A of the inner ring 72A of the outer bearing 72 is larger than the outer diameter d74B of the outer ring 74B of the inner bearing 74. In other words, the outer bearing 72 has a larger diameter as the entire outer bearing 72 is positioned more radially outward than the inner bearing 74. As a result, a large transmission capacity can be secured and the support rigidity of the crankshaft 40 can be maintained high.

  In the present embodiment, this advantage is utilized to configure the outer bearing 72 with a ball bearing. As a result, the gear unit G1 can be configured at a lower cost and with a smaller power loss (compared to, for example, a case where a roller-type rolling element is used as the bearing of the crankshaft 40). Since the power loss tends to increase as the diameter of the bearing increases, it is advantageous that the bearing of the crankshaft 40 can be constituted by a ball bearing.

  However, in the present invention, the outer diameter or inner diameter of the outer bearing 72 and the outer diameter or inner diameter of the inner bearing 74 are not particularly limited (the outer bearing 72 is not necessarily larger than the inner bearing 74). Absent). For example, the inner diameter of the hollow portion (large diameter hollow portion 40P2 in the above example) where the inner bearing of the crankshaft is arranged is outside the outer periphery (outer periphery 40A on the reaction power input side in the above example) on the side where the outer bearing is arranged. For example, the outer diameter of the outer bearing may be set to be smaller than the outer diameter of the inner bearing by enlarging it so as to be much larger than the diameter.

  Here, the inner bearing 74 of the present embodiment is disposed on the “inner circumference” of the crankshaft 40 and supports the crankshaft 40 from the radially inner side. For this reason, the crankshaft 40 is designed at an arbitrary axial position of the crankshaft 40 without depending on the arrangement position of members (external gear 30, power input member 52, etc.) incorporated in the crankshaft 40. Can be supported. Therefore, compactness (especially axial compactness) can be realized, and more flexible design can be realized.

  Specifically, for example, in this gear device G1, in consideration of the fact that the power input member 52 is connected to the axial direction end 40E of the crankshaft 40, the shaft member 20S is intentionally connected to the external gear 30. An inner bearing 74 is disposed in a portion that extends from one side in the axial direction (reaction power input side) to the other side (power input side) and the shaft member 20S extends beyond the external gear 30 in the axial direction. Yes. As a result, the inner bearing 74 overlaps with the power input member 52 in the radial direction, and accordingly, the axial compactness of the entire apparatus can be realized. Further, the power input member 52 can be stably supported.

  On the other hand, in the gear device G1, the inner bearing 74 is arranged so as not to overlap with the eccentric body bearing 56 (bearing disposed between the swinging gear and the crankshaft) when viewed from the radial direction. Yes. Thereby, when the inner bearing 74 is press-fitted into the large-diameter hollow portion 40P2, the deformation of the crankshaft 40 due to the press-fitting is prevented from adversely affecting the eccentric body bearing 56.

  The outer bearing 72 is originally arranged on the carrier 20 having a large thickness in the axial direction. Therefore, even if it is arranged outside the crankshaft 40, the compactness in the axial direction is not impaired. By arranging the outer bearing 72 having a large diameter, the transmission capacity can be increased.

  In the gear device G1, the main bearing 60 that supports the casing 10 and the carrier 20 so as to be relatively rotatable is disposed between the casing 10 and the carrier 20, and the main bearing 60 and the outer bearing 72 have a diameter. Overlapping from the direction. That is, the main bearing 60 and the outer bearing 72 are located on substantially the same plane Pc. As a result, the gear device G1 can be made compact in the axial direction, the support rigidity around the plane Pc can be maintained high, and the rotational stability of each member can be improved.

  In the gear device G1, the crankshaft 40 has a small-diameter hollow portion 40P1 having a small hollow diameter D40P1, and a large-diameter hollow portion 40P2 having a hollow diameter D40P2 larger than the hollow diameter D40P1 of the small-diameter hollow portion 40P1. doing. And the inner side bearing 74 is arrange | positioned in this large diameter hollow part 40P2.

  Thereby, the outer diameter d74B of the outer ring 74B of the inner bearing 74 can be made larger, and the transmission capacity of the inner bearing 74 can be secured larger. Further, the wall surface 40W2 formed at the boundary between the small-diameter hollow portion 40P1 and the large-diameter hollow portion 40P2 can be used as a positioning surface on the reaction power input side of the inner bearing 74, and the arrangement of positioning members such as retaining rings is omitted. can do.

  In the present embodiment, the outer bearing 72 is arranged at the end of the crankshaft 40 on the carrier 20 side, and the inner bearing 74 is arranged at the end of the crankshaft 40 on the side opposite to the carrier 20. However, in the present invention, the position of the outer bearing 72 and the inner bearing 74 in the axial direction of the crankshaft 40 is not particularly limited. For example, the outer bearing 72 may be disposed at the end of the crankshaft 40 on the side opposite to the carrier 20, or may be disposed in the vicinity of the center in the axial direction of the crankshaft 40 as in an embodiment described later. May be. The same applies to the inner bearing 74, and the arrangement position in the axial direction is not particularly limited. When at least one of the outer bearing 72 and the inner bearing 74 is constituted by a bearing that can support the thrust direction and the radial direction of the crankshaft 40 by only one, such as a self-aligning roller bearing or a cross roller bearing. Alternatively, the outer bearing 72 and the inner bearing 74 may be arranged so as to overlap each other when viewed from the radial direction.

  FIG. 2 shows a configuration example of an eccentric oscillating gear device G101 according to another embodiment of the present invention.

  The parts that are technically common to or corresponding to the embodiment of FIG. 1 are denoted by the same reference numerals in the last two digits, and redundant description will be omitted as appropriate.

  Also in this eccentric oscillating gear device G101, the crankshaft 140 has hollow portions (small-diameter hollow portion 140P1 and large-diameter hollow portion 140P2). The casing 110 or the carrier 120 integrally includes a shaft member 110S that is inserted into the large-diameter hollow portion 140P2. In this example, unlike the previous example, the casing 110 (specifically, a third casing body 113 to be described later) integrally includes the shaft member 110S.

  Note that, as in the example of FIG. 2 and the example of FIG. 3 to be described next, for example, in the case of a structure in which the shaft member does not penetrate the small-diameter hollow portion, Good. That is, there may be a structure in which the small-diameter hollow portion does not actually exist (the portion corresponding to the small-diameter hollow portion is solid) and only the bottomed large-diameter hollow portion exists.

  Gear device G101 includes an outer bearing 172 disposed between outer periphery 140A of crankshaft 140 and inner periphery 120R2 of casing 110 or carrier 120 (carrier 120 in this example). The gear device G101 includes an inner bearing 174 disposed between the inner periphery (large-diameter hollow portion 140P2) of the crankshaft 140 and the outer periphery 110S1 of the shaft member 110S.

  The crankshaft 140 of the gear device G101 has a tap hole 140T for connecting a power input member (not shown) to an end 140E on the side where the carrier 120 is disposed (as opposed to the previous example). Yes. That is, the side on which the carrier 120 is disposed is the power input side.

  In other words, in the gear device G101, contrary to the previous gear device G1, the outer bearing 172 is disposed closer to the axial power input side than the inner bearing 174.

  The casing 110 of the gear device G101 includes a first casing body 111 integrated with the internal gear main body 150A, a second casing body 112 disposed on the carrier 120 side of the first casing body 111, and a first casing body. 111 is constituted by a third casing body 113 disposed on the side opposite to the carrier 120.

  The structure of the 1st, 2nd casing bodies 111 and 112 is the same as that of embodiment of FIG. However, the 3rd casing body 113 is comprised by the disk-shaped member without an opening part. And this 3rd casing body 113 has integrally the shaft member 110S inserted in the large diameter hollow part 140P2 of the crankshaft 140 in the radial direction center. The shaft member 110 </ b> S protrudes from the third casing body 113 by an axial length substantially corresponding to the axial width of the inner bearing 174.

  Thus, the shaft member may be integrated with the carrier as in the previous embodiment, or may be integrated with the casing as in the present embodiment. In addition, as in the above two embodiments, the structure may be integrated with the casing or the carrier from the beginning, or the single shaft member may be connected with the casing or the carrier by bolts or press-fitting. Also good.

  Note that the central portion in the radial direction of the third casing body 113 is shifted by δ 113 toward the non-carrier 120 side (reactive power input side). With this configuration, the third casing body 113 functions as a pressing plate for the inner tooth pin 150 </ b> C and the inner roller 164 in the radially outer portion of the third casing body 113. In addition, a space for forming the protrusion 140 </ b> H on the crankshaft 140 is secured at the radial center of the third casing body 113. The protrusion 140H positions the retainer 156R of the eccentric bearing 156.

  The carrier 120 of the gear unit G101 is formed so as to protrude toward the axial external gear 130 at a position offset from the axis C120R of the ring part 120R and the ring part 120R disposed opposite to the second casing body 112. And a plurality of inner pins 162. That is, the carrier 120 of the gear device G101 does not need to have a disk-like flange portion for projecting the shaft member, and therefore does not have the flange portion that was present in the gear device G1 of FIG. Instead, the opening 120R5 is formed in the ring portion 120R of the carrier 120, and the opening 120R5 is used to input power from the drive source side.

  The gear device G101 includes the crankshaft 140, the casing 110, and the carrier 120 having the above-described configuration, and is disposed between an outer periphery 140A approximately in the center in the axial direction of the crankshaft 140 and an inner periphery of the carrier 120 (the ring portion 120R). An outer bearing 172 is disposed. Further, an inner bearing 174 is provided between the inner periphery (large-diameter hollow portion 140P2) of the end of the crankshaft 140 on the axial direction counter-power input side and the outer periphery 110S1 of the shaft member 110S (integrated with the casing 110). Has been placed.

  In the gear device G101 of FIG. 2, the outer bearing 172 is positioned on the axial power input side (because the carrier 120 does not have a flange portion), the outer ring of the outer bearing 172 is provided on the ring portion 120R of the carrier 120. This is done by contacting the shoulder 120R3.

  The large-diameter hollow portion 140P2 of the crankshaft 140 of the gear device G101 overlaps with the eccentric body bearing 156 when viewed from the radial direction. That is, in the gear device G101, the eccentric body bearing 156 and the inner bearing 174 overlap each other when viewed from the radial direction. Thereby, the protrusion amount of the crankshaft 140 on the side opposite to the carrier 120 from the eccentric body 154 is suppressed, and the gear device G101 is made compact in the axial direction.

  FIG. 3 shows a configuration example of an eccentric oscillating gear device G201 according to still another embodiment of the present invention.

  The gear device G201 of FIG. 3 basically has the same configuration as the gear device G101 of FIG. Therefore, the same two-digit numbers are assigned to the parts that are technically common to or corresponding to the embodiment of FIG.

  A major feature of the gear device G201 is that the main bearing 260 that supports the casing 210 and the carrier 220 in a relatively rotatable manner is not disposed between the casing 210 and the carrier 220. That is, in this gear device G201, on the assumption that the gear device G201 is incorporated in the joint portion of the industrial robot, the main bearing 260 is not disposed between the casing 210 and the carrier 220 of the gear device G201, and the The robot R901 is arranged between the first joint member 981 and the second joint member 982, which are constituent elements of the robot R901.

  This configuration will be described in more detail with reference to FIGS.

  FIG. 4 shows an example of an industrial robot R901 in which the gear device G201 of FIG. 3 is incorporated in the fifth-stage indirect portion. For convenience, the gear device G201 in FIG. 3 is hereinafter referred to as a fifth gear device. This industrial robot R901 is a welding robot called a spot gun having six degrees of freedom.

  A bevel gear 952 as a power input member is connected to an axial end 240E of the crankshaft 240, which is an input shaft of the fifth gear device G201, using the tap hole 240T. The bevel gear 952 is configured to receive power from a motor (not shown) via a bevel pinion 954.

  The carrier 220 of the fifth gear apparatus G201 is connected to the first joint member 981 of the industrial robot R901 via a bolt 984. In this example, the first joint member 981 is an output member of a gear device (fourth gear device) G401 incorporated in the joint portion of the previous stage (fourth stage).

  Further, the casing 210 of the fifth gear apparatus G201 is connected to the second joint member 982 of the industrial robot R901 via a bolt 985. In this example, the second joint member 982 connects the casing 210 of the fifth stage gear unit G201 and the casing 610 of the gear unit (sixth stage gear unit) G601 incorporated in the joint part of the rear stage (sixth stage). It is a joint casing.

  In other words, the fifth stage gear device G201 of the industrial robot shown in FIG. 3 is connected to the first joint member 981 (which is an output member in the previous stage) connected to the carrier 220 and to the casing 210. It can be understood that the second joint member 982 (which is the rear casing 210) is attached.

  In the fifth-stage gear device G201, a main bearing 260 that supports the casing 210 and the carrier 220 so as to be relatively rotatable (not disposed between the casing 210 and the carrier 220) and the first joint member 981 and the second joint It is arranged between the member 982. In this embodiment, the main bearing 260 is constituted by a cross roller bearing.

  More specifically, as shown in FIG. 4, the first joint member 981 has a rotation center line (rotation center line of the output member of the fourth gear device G401 incorporated in the previous joint) C981 and It extends substantially coaxially and reaches the vicinity of the crankshaft 240 of the fifth stage gear device G201.

  The first joint member 981 is connected to the carrier 220 of the fifth gear device G201 via a bolt 984 on one side of the rotation center line C981 across the rotation center line C981 of the first joint member 981. . The first joint member 981 has a pipe shaft portion 981S coaxial with the axis C240 of the crankshaft 240 of the fifth stage gear device G201 on the other side of the rotation center line C981.

  On the other hand, the second joint member 982 is formed of a substantially cylindrical member. The second joint member 982 has an outer fitting portion 982R that surrounds the pipe shaft portion 981S from the outside at the cylindrical end portion 982E.

  The main bearing 260 of the fifth gear device G201 is disposed between the pipe shaft portion 981S of the first joint member 981 and the outer fitting portion 982R of the second joint member 982.

  That is, with the rotation center line C981 of the first joint member 981 interposed therebetween, the fifth step gear device G201 is arranged on one side of the rotation center line C981, and the main bearing 260 of the fifth step gear device G201 is arranged on the other side. Has been. With such a configuration, the carrier 220 and the casing 210 of the fifth stage gear device G201 are supported by the main bearing 260 so as to be relatively rotatable, and in particular, the fifth stage gear device G201 of the rotation center line C981 in particular. The axial dimension LG201 on the gear mechanism side (the side on which the crankshaft 240 and the external gear 230 are located) is made compact.

  The “rotation center line” having the configuration “the fifth stage gear device G201 is disposed on one side of the rotation center line C981 and the main bearing 260 of the fifth stage gear device G201 is disposed on the other side”. Can also be regarded as a rotation center line C622 of an output member (second carrier 622 to be described later) of a sixth-stage gear device G601 incorporated in a “rear stage (sixth stage) joint part” of the joint part. That is, this industrial robot R901 recognizes that “the fifth stage gear device G201 is arranged on one side of the rotation center line C622 and the main bearing 260 of the fifth stage gear device G201 is arranged on the other side”. You can also.

  Further, the industrial robot R901 has the following structure: “A fifth plane gear device G201 is arranged on one side of the plane P901 with the plane P901 including the rotation center line C981 and the rotation center line C622 interposed therebetween, and the fifth stage gear device G201 on the other side. The main bearing 260 of the stepped gear device G201 is disposed. "

  Finally, the configuration of the rear stage of the industrial robot R901 with respect to the fifth stage gear unit G201 will be briefly described.

  Referring mainly to FIG. 5, the sixth-stage gear device G601 subsequent to the fifth-stage gear device G201 has a dedicated motor 605. A motor shaft 605A of the motor 605 is connected to the crankshaft 640 via pulleys 608 and 609. An external gear 630 is incorporated in the crankshaft 640 via an eccentric body 654 and an eccentric body bearing 656 so as to be able to swing and rotate. The external gear 630 is in mesh with the internal gear 650. The number of internal teeth of the internal gear 650 is slightly larger (for example, by 1) than the number of external teeth of the external gear 630. First and second carriers 621 and 622 are disposed on both sides of the external gear 630 in the axial direction. The first and second carriers 621 and 622 are rotatably supported by the casing 610 via main bearings 660A and 660B.

  As described above, the casing 610 of the sixth gear device G601 is connected to the casing 210 of the fifth gear device G201 via the second joint member 982. The external gear 630 has a plurality of inner pins 662 passing therethrough at a position offset from the axis. Since the inner pin 662 passes through the external gear 630, it moves in synchronization with the rotation of the external gear 630. The inner pin 662 is supported by the first and second carriers 621 and 622.

  The inner pin 662 is fitted into the first carrier 621 by a clearance fit. The inner pin 662 is fitted (press-fitted) into the second carrier 622 by an interference fit. An inner roller 664 is fitted on the inner pin 662 as a sliding promotion member.

  Two rows of first and second needle bearings 691 and 692 are arranged in the axial direction between the inner pin 662 and the inner roller 664. The first and second needle bearings 691 and 692 are held via first and second retainers 691R and 692R, respectively. The first and second needle bearings 691 and 692 are positioned in the axial direction by being sandwiched between the first and second carriers 621 and 622 while the first and second retainers 691R and 692R are in contact with each other in the axial direction. ing.

  When the first and second needle bearings 691 and 692 are arranged in this manner between the inner pin 662 and the inner roller 664, relative rotation between the inner pin 662 and the inner roller 664 can be performed very smoothly. Even if an unexpected load is transmitted from the spot gun device 988 side, the influence is minimized, and as a result, the external gear 630 can be smoothly swung and rotated.

  In addition, since the two first and second needle bearings 691 and 692 are incorporated in parallel, the first and second needle bearings 691 and 691 are compared with the configuration in which one long needle bearing is incorporated. 692 can be rotated in a slightly different manner individually. As a result, the load from the spot gun device 988 side can be absorbed better.

  The first and second carriers 621 and 622 rotate by the revolution of the inner pin 662 and the inner roller 664. An attachment 989 having a spot gun device 988 is connected to the second carrier 622 via an adapter 983 connected by a bolt 986. In the sixth stage gear device G601, when the motor shaft 605A of the motor 605 rotates, the first and second carriers 621 and 622 rotate relative to the casing 610 connected to the second joint member 982, The entire attachment 989 connected to the second carrier 622 side rotates around the rotation center line C622 of the second carrier 622 that is the output member of the sixth stage gear device G601.

  In the above embodiment, a) the outer bearing is disposed between the outer periphery of the crankshaft and the inner periphery of the carrier, and the inner bearing is formed between the inner periphery of the crankshaft and the outer periphery of the shaft member integrated with the carrier. A configuration in which the outer bearing is disposed between the outer periphery of the crankshaft and the inner periphery of the carrier, and the inner bearing is integrated with the inner periphery of the crankshaft and the casing. A configuration (configuration shown in FIGS. 2 and 3) disposed between the outer periphery of the members is shown.

  However, the present invention is not limited to this configuration example. For example, c) the outer bearing is disposed between the outer periphery of the crankshaft and the inner periphery of the casing, and the inner bearing is integrated with the inner periphery of the crankshaft and the carrier. Or a configuration in which the outer bearing is disposed between the outer periphery of the crankshaft and the inner periphery of the casing, and the inner bearing is disposed on the inner periphery of the crankshaft and the casing. You may employ | adopt the structure arrange | positioned between the outer periphery of the integrated shaft member.

  Conventionally, this type of eccentric oscillating gear device has various casing structures and carrier structures. That is, in each of the above embodiments, the configuration example in which the carrier is disposed only on one side in the axial direction of the rocking gear is shown. However, as the eccentric rocking gear device, for example, the sixth stage A configuration having carriers on both sides in the axial direction of the oscillating gear is also known as employed in gear devices. In the above embodiment, there is provided an eccentric oscillating gear device called a so-called center crank type in which only one crankshaft is provided on the shaft center of a non-oscillating gear (in the above example, an internal gear). It was shown. However, as an eccentric oscillating gear device, for example, a so-called distribution type in which a plurality of crankshafts having eccentric bodies for oscillating the oscillating gear are provided at positions offset from the axis of the non-oscillating gear, Also known is an eccentric oscillating gear device. Furthermore, in the said embodiment, the structural example in which the rocking | fluctuation gear was comprised with the external gear and the non-oscillation gear was comprised with the internal gear was shown. However, as an eccentric oscillating gear device, for example, a gear device in which this relationship is reversed and an external gear is a non-oscillating gear and an internal gear is an oscillating gear is also known. It is. The present invention can be applied to an eccentric oscillating gear device of any configuration.

  When this type of eccentric oscillating gear device is incorporated into, for example, a joint portion of an industrial robot, as exemplified in the above-described embodiment, the gear device is arranged in accordance with the arrangement of the front and rear joint members and the motor. On the other hand, it is necessary to input and output power from various directions. In addition, it is required to realize high compactness while maintaining a large transmission capacity or high support rigidity.

  For this reason, the design of a gear device having various casing structures and carrier structures is required in response to these requirements. On the other hand, in this type of eccentrically oscillating gear device, as exemplified in the above embodiment, for example, there is a carrier only on one side in the axial direction of the crankshaft, or power is supplied only on one side. There are often input members, and there is often a “difference” in the radial margin between the axial power input side and the counter-power input side of the crankshaft. In the present invention, since the outer bearing is provided on the outer periphery of the crankshaft and the inner bearing is provided on the inner periphery of the crankshaft, the flexibility with respect to the “difference” in the radial direction is extremely high. A dynamic gear device can be designed and can be widely applied to various industrial robots.

G1 ... Gear device 10 ... Case 20 ... Carrier 20S ... Shaft member 30 ... External gear (oscillating gear)
40 ... Crankshaft 40P2 ... (large diameter) hollow part 72 ... Outer bearing 74 ... Inner bearing

Claims (10)

In an eccentric oscillating gear device comprising a casing, a carrier that rotates relative to the casing, an oscillating gear, and a crankshaft that oscillates and rotates the oscillating gear.
The crankshaft has a hollow portion;
The casing or the carrier has a shaft member inserted into the hollow portion,
The gear device further includes:
An outer bearing disposed between the outer periphery of the crankshaft and the inner periphery of the casing or the carrier;
An eccentric oscillating gear device, comprising: an inner bearing disposed between an inner periphery of the crankshaft and an outer periphery of the shaft member. In claim 1,
An eccentric bearing disposed between the swing gear and the crankshaft;
The eccentric oscillating gear device, wherein the eccentric bearing and the inner bearing overlap each other when viewed from the radial direction. In claim 1,
An eccentric bearing disposed between the swing gear and the crankshaft;
The eccentric oscillating gear device, wherein the eccentric bearing and the inner bearing do not overlap each other when viewed from the radial direction. In claim 3,
The shaft member extends from one side in the axial direction of the rocking gear to the other side,
The eccentric oscillating gear device, characterized in that the inner bearing is disposed in a portion where the shaft member extends beyond the oscillating gear in the axial direction. In claim 3 or 4,
A power input member connected to an end of the crankshaft, to which power from a power source is input;
The eccentric oscillating gear device, wherein the power input member and the inner bearing overlap each other when viewed from the radial direction. In any one of Claims 1-5,
A main bearing for rotatably supporting the casing and the carrier is disposed between the casing and the carrier;
The eccentric oscillating gear device, wherein the main bearing and the outer bearing overlap each other when viewed in the radial direction. In any one of Claims 1-6,
The shaft member is integrated with the carrier;
The outer bearing is disposed between the outer periphery of the crankshaft and the inner periphery of the carrier. In any one of Claims 1-7,
The eccentric oscillating gear device, wherein the outer bearing is disposed closer to the axial power input side than the inner bearing. In any one of Claims 1-8,
The crankshaft has a small-diameter hollow portion having a small hollow diameter including 0, and a large-diameter hollow portion having a hollow diameter larger than the hollow diameter of the small-diameter hollow portion,
The eccentric oscillating gear device, wherein the inner bearing is disposed in the large-diameter hollow portion. An industrial robot in which the eccentric rocking gear device according to any one of claims 1 to 5 and 7 to 9 is incorporated in a joint portion,
A first joint member coupled to the carrier;
A second joint member coupled to the casing,
A main bearing that supports the casing and the carrier so as to be relatively rotatable is not disposed between the casing and the carrier, but is disposed between the first joint member and the second joint member, and The speed reduction mechanism of the gear device is arranged on one side of the rotation center line across the rotation center line of the output member of the gear device incorporated in the joint portion at the front stage or the joint portion at the rear stage of the joint portion, and on the other side. An industrial robot, wherein the main bearing is disposed.

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