Eccentric oscillating gear device and method for assembling eccentric oscillating gear device

Abstract

The invention provides an eccentric swing type gear device which can obtain good operability in assembly work when a crankshaft bearing uses a separation type bearing. An eccentric oscillating gear device (10) is provided with: a crankshaft (14) having an eccentric part (12); and a crankshaft bearing (22A) that supports the crankshaft (14) at a position offset in the axial direction with respect to the eccentric portion (12), the crankshaft bearing (22A) being a separate bearing in which an inner ring (56) can be separated in the axial direction with respect to the rolling body (50). The restricting member (60) is capable of restricting the rolling body (50) from moving in the axial direction with respect to the inner ring (56) in a state where the outer ring (54) of the crankshaft bearing (22A) is separated from the rolling body (50).

Description

[0001] This application claims priority based on Japanese Patent Application No. 2023-209661 filed on December 12, 2023. The entire content of this Japanese application is incorporated herein by reference. Technical Field

[0002] The present invention relates to an eccentric swing type gear device and an assembling method of the eccentric swing type gear device. Background Art

[0003] Patent Document 1 discloses an eccentric swing type gear device including: a crankshaft having an eccentric portion; a crankshaft bearing that supports the crankshaft at a position axially offset from the eccentric portion; and a wheel carrier that supports the crankshaft bearing. This crankshaft bearing uses a separable bearing in which the inner ring is axially separable relative to the rolling elements. The outer ring of the crankshaft bearing in Patent Document 1 is integrally provided with the wheel carrier by the same component as the wheel carrier, and the inner ring is integrally provided with the crankshaft by the same component as the crankshaft.

[0004] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2021-67325

[0005] When using the above separable bearing as the crankshaft bearing, during the assembly process of the gear device, axial movement of the rolling elements disposed on the inner ring is allowed in a state where the outer ring is separated from the rolling elements. Therefore, if the rolling elements on the inner ring are significantly axially displaced during the assembly process, there will be a problem of deteriorated operability during the assembly operation. Summary of the Invention

[0006] Therefore, one object of the present invention is to provide an eccentric swing type gear device that can achieve good operability during the assembly operation when a separable bearing is used as the crankshaft bearing.

[0007] The eccentric swing type gear device of the present invention includes: a crankshaft having an eccentric portion; and a crankshaft bearing that supports the crankshaft at a position axially offset from the eccentric portion, the crankshaft bearing being a separable bearing in which the inner ring is axially separable relative to the rolling elements, and the eccentric swing type gear device includes a restricting member that can restrict axial movement of the rolling elements relative to the inner ring in a state where the outer ring of the crankshaft bearing is separated from the rolling elements.

[0008] According to the present invention, good operability can be achieved during the assembly operation when a separable bearing is used as the crankshaft bearing. Brief Description of the Drawings

[0009] Figure 1 It is a side view cross-sectional view showing the gear device of the first embodiment.

[0010] Figure 2 IsFigure 1 Partial enlarged view.

[0011] Figure 3 It is the first explanatory diagram of the assembly method of the first embodiment.

[0012] Figure 4 It is the second explanatory diagram of the assembly method of the first embodiment.

[0013] Figure 5 It is the third explanatory diagram of the assembly method of the first embodiment.

[0014] Figure 6 It is the explanatory diagram of the assembly method of the second embodiment.

[0015] Figure 7 It is the partial enlarged view of the gear device of the third embodiment.

[0016] In the figure: 10 - Eccentric swing type gear device, 12 - Eccentric part, 14 - Crankshaft, 22A - First crankshaft bearing, 22B - Second crankshaft bearing, 24A - First wheel carrier, 24B - Second wheel carrier, 26 - Crankshaft gear, 50 - Rolling element, 52 - Retainer, 54 - Outer ring, 56 - Inner ring, 60 - Limiting component, 62 - Hard component, 64 - Soft component, 70 - Contact part, 72 - Positioning part, 76 - Axial clearance. Detailed embodiments

[0017] Hereinafter, embodiments of the eccentric swing type gear device (hereinafter, also simply referred to as the gear device) of the present invention will be described. The same or equivalent components are denoted by the same reference signs, and repeated descriptions are omitted. In each drawing, for the sake of convenience of explanation, the components are appropriately omitted, enlarged, and reduced. Observe the drawings according to the orientation of the reference signs.

[0018] Reference Figure 1 . The gear device 10 is assembled as a part of the driven machine to the driven machine. The driven machine is, for example, various machines such as industrial machines (machine tools, construction machines, etc.), robots (industrial robots, service robots, etc.), handling equipment (conveyors, vehicles, etc.).

[0019] The gear device 10 includes: a crankshaft 14 having at least one eccentric portion 12; a swing gear 16 swung by the eccentric portion 12; a meshing gear 18 meshing with the swing gear 16; and a housing 20 disposed radially outside the swing gear 16. In addition, the gear device 10 further includes: crankshaft bearings 22A and 22B that support the crankshaft 14 at positions axially offset from the eccentric portion 12 of the crankshaft 14; and wheel carriers 24A and 24B that support the crankshaft bearings 22A and 22B. Hereinafter, the direction along the swing center C16A of the swing gear 16 is referred to as the axial direction of the swing gear 16, and the radial direction and the circumferential direction with the swing center C16A as the center of the circle are referred to as the radial direction and the circumferential direction of the swing gear 16, respectively.

[0020] In the present embodiment, a distributive eccentric swing type gear device 10 will be described. This type of gear device 10 includes a plurality of crankshafts 14 disposed at positions radially offset from the swing center C16A of the swing gear 16, and a crankshaft gear 26 fixed to at least one crankshaft 14.

[0021] The gear device 10 includes an input member that inputs rotation from an external drive source and an output member that outputs rotation to an external driven member. Here, an example in which the crankshaft gear 26 is an input member and the second wheel carrier 24B described later is an output member will be described. The drive source is, for example, a motor, but in addition to this, it may also be a gear motor, an engine, or the like.

[0022] In the present embodiment, the number of crankshafts 14 is three, but only one of them is illustrated. The plurality of crankshafts 14 are arranged at intervals in the circumferential direction of the swing gear 16. The plurality of crankshafts 14 penetrate the swing gear 16 and the wheel carriers 24A and 24B in the axial direction of the swing gear 16.

[0023] The crankshaft 14 includes at least one (here, two) eccentric portions 12 and shaft portions 28A and 28B provided on both axial sides with respect to the eccentric portion 12. The shaft portions 28A and 28B include an input side shaft portion 28A (one side shaft portion) provided on one side in the axial direction with respect to the eccentric portion 12 ( Figure 1 the right side of the paper surface in the figure) and an output side shaft portion 28B (the other side shaft portion) provided on the other side in the axial direction with respect to the eccentric portion 12 ( Figure 1 the left side of the paper surface in the figure). In this specification, for the sake of convenience of explanation, one side in the axial direction is referred to as the input side, and the other side in the axial direction is referred to as the output side. In the present embodiment, the eccentric portion 12 is formed integrally with the shaft portions 28A and 28B by the same components as the shaft portions 28A and 28B, but it may also be separately provided from the shaft portions 28A and 28B.

[0024] The axis C12 of the eccentric portion 12 is eccentric with respect to the rotation center line C14 of the crankshaft 14. The eccentric portion 12 is circular with the axis C12 as the center. The eccentric portion 12 rotates about the rotation center line C14 of the crankshaft 14, causing the oscillating gear 16 to oscillate. Here, "oscillation" means that the gear center C16B of the oscillating gear 16 rotates about the oscillation center C16A. The number of the eccentric portions 12 is not particularly limited and can be any one of one and three or more.

[0025] The number of the crankshaft gears 26 in the present embodiment is three, but only one of them is illustrated. The number of the crankshaft gears 26 can also be one. A plurality of crankshaft gears 26 are respectively fixed to a plurality of crankshafts 14. A common transmission gear 30 meshes with the respective crankshaft gears 26 of the plurality of crankshafts 14. The rotation output from the drive source is distributed to each crankshaft 14 via the transmission gear 30. The transmission gear 30 is provided, for example, on the outer peripheral portion of the output shaft 32 of the drive source.

[0026] A central hole 26a through which the input side shaft portion 28A of the crankshaft 14 passes is formed in the central portion of the crankshaft gear 26. The axial position of the crankshaft gear 26 with respect to the crankshaft 14 is fixed by a gear fixing member 34 such as a snap ring mounted on the crankshaft 14. The crankshaft gear 26 is integrally rotatably coupled to the crankshaft 14 through a coupling structure 36. The coupling structure 36 exemplifies a spline structure, but in addition to this, it can also be a keyway structure or the like.

[0027] In the present embodiment, the oscillating gear 16 is an external gear and the meshing gear 18 is an internal gear. The oscillating gears 16 are respectively provided corresponding to the plurality of eccentric portions 12 and are supported on the corresponding eccentric portions 12 via eccentric bearings 38. The meshing gear 18 of the present embodiment includes a meshing gear main body 18a integrated with the housing 20 and a plurality of tooth portions 18b provided on the meshing gear main body 18a and meshing with the oscillating gear 16. The plurality of tooth portions 18b in the present embodiment are formed integrally with the meshing gear main body 18a by the same member as the meshing gear main body 18a. In addition to this, the plurality of tooth portions 18b can also be constituted by a plurality of pins rotatably supported on the meshing gear main body 18a.

[0028] The crankshaft bearings 22A and 22B include a first crankshaft bearing 22A that supports the input side shaft portion 28A of the crankshaft 14 and a second crankshaft bearing 22B that supports the output side shaft portion 28B of the crankshaft 14. An eccentric bearing restricting member 39 is disposed between each of the crankshaft bearings 22A and 22B and the eccentric bearing 38. The eccentric bearing restricting member 39 contacts the eccentric bearing 38 from the axially outer side to restrict the eccentric bearing 38 from moving axially outward. The eccentric bearing restricting member 39 is provided separately from the crankshaft 14.

[0029] The wheel carriers 24A and 24B include a first wheel carrier 24A that supports the first crankshaft bearing 22A and a second wheel carrier 24B that supports the second crankshaft bearing 22B. A first shaft hole 24Aa into which the input side shaft portion 28A of the crankshaft 14 is inserted is formed in the first wheel carrier 24A. A second shaft hole 24Ba into which the output side shaft portion 28B of the crankshaft 14 is inserted is formed in the second wheel carrier 24B. The first wheel carrier 24A and the second wheel carrier 24B are connected together via a pin body 40 that passes through the oscillating gear 16. The pin body 40 is integrated with one of the first wheel carrier 24A and the second wheel carrier 24B (here it is the second wheel carrier 24B), and is fixed by a fixing member 42 such as a bolt in a state of abutting against the other wheel carrier (here it is the first wheel carrier 24A).

[0030] A main bearing 44 is disposed between the housing 20 and the wheel carriers 24A and 24B. The main bearing 44 exemplifies an angular contact ball bearing, but its specific example is not particularly limited, and it may also be composed of a crossed roller bearing, a ball bearing, etc.

[0031] An example of the operation of the above gear device 10 will be described. If the transmission gear 30 rotates by the output of the drive source, the rotation of the transmission gear 30 is transmitted to at least one crankshaft 14 via the crankshaft gear 26. At this time, the rotation of the transmission gear 30 is decelerated by the crankshaft gear 26 and then transmitted to the crankshaft 14. If the crankshaft 14 rotates, the oscillating gear 16 is oscillated by the eccentric portion 12 of the crankshaft 14. If the oscillating gear 16 oscillates, the meshing position of the oscillating gear 16 and the meshing gear 18 changes in the circumferential direction. Thus, every time the crankshaft 14 rotates once, one of the oscillating gear 16 and the meshing gear 18 (here it is the oscillating gear 16) rotates self, and this self-rotation component is output by the output member (here it is the second wheel carrier 24B). At this time, the output rotation that has decelerated the input rotation input to the crankshaft 14 at a reduction ratio corresponding to the tooth number difference between the oscillating gear 16 and the meshing gear 18 is output by the output member.

[0032] Reference Figure 2 Hereinafter, the components related to one crankshaft 14 (crankshaft bearings, wheel carriers, crankshaft gear 26, etc.) will be described. And when explaining the positional relationship between these components, the axial direction, radial direction, and circumferential direction of this crankshaft 14 are mainly used for the explanation. And when explaining these components, the terms "axially outer side" and "axially inner side" are sometimes used. Here, the axially outer side means the side that is far from the eccentric portion 12 in the axial direction of the crankshaft 14, and the axially inner side means the side that is close to the eccentric portion 12 in the axial direction. And hereinafter, regarding the same structure of the first crankshaft bearing 22A and the second crankshaft bearing 22B, the first crankshaft bearing 22A will be referred to for the explanation.

[0033] The crankshaft bearings 22A and 22B include a plurality of rolling elements 50, a retainer 52 that holds the plurality of rolling elements 50 so as to be rotatable, and an outer ring 54 and an inner ring 56 on which the plurality of rolling elements 50 roll.

[0034] The retainer 52 is capable of rotating together with the plurality of rolling elements 50 about the rotation center line C14 of the crankshaft 14. The plurality of rolling elements 50 and the retainer 52 constitute a rolling element unit 58.

[0035] The outer ring 54 is integrated with the wheel carriers 24A and 24B. Here, "integrated" means that regardless of whether the two components mentioned are the same or different components, as long as they are configured as one body. The outer ring 54 of the first crankshaft bearing 22A is integrated with the first wheel carrier 24A, and the outer ring 54 of the second crankshaft bearing 22B is integrated with the second wheel carrier 24B. In the present embodiment, the outer ring 54 is formed integrally with the wheel carriers 24A and 24B by the same components as the wheel carriers 24A and 24B, and is formed by the inner peripheral portions of their shaft holes 24Aa and 24Ba. In addition, the outer ring 54 may be separately provided from the wheel carriers 24A and 24B and fixed to the shaft holes 24Aa and 24Ba of the wheel carriers 24A and 24B by interference fit or the like. The outer ring 54 has an outer raceway surface 54a on which the rolling elements 50 roll and an outer movement restricting portion 54b that restricts the rolling elements 50 from moving axially outward. The outer raceway surface 54a has a shape in which its inner diameter gradually decreases toward the axially outer side. The outer movement restricting portion 54b of the present embodiment is provided axially outside with respect to the rolling elements 50 and has a stepped shape that protrudes radially inward with respect to the outer raceway surface 54a.

[0036] The inner ring 56 is integrated with the crankshaft 14. In the present embodiment, the inner ring 56 is formed integrally with the crankshaft 14 by the same components as the crankshaft 14, and is formed by its outer peripheral portion. In addition, the inner ring 56 may be separately provided from the crankshaft 14 and fixed to the outer peripheral portion of the crankshaft 14 by interference fit or the like. The inner ring 56 has an inner raceway surface 56a on which the rolling elements 50 roll and an inner movement restricting portion 56b that restricts the rolling elements 50 from moving axially inward. The inner raceway surface 56a has a shape in which its outer diameter gradually decreases toward the axially outer side. The inner movement restricting portion 56b of the present embodiment is provided axially inside with respect to the rolling elements 50 and has a stepped shape that protrudes radially outward with respect to the inner raceway surface 56a.

[0037] The crankshaft bearings 22A and 22B are split-type bearings that can separate the outer ring 54 and the inner ring 56 in the axial direction relative to the rolling element 50. The first crankshaft bearing 22A and the second crankshaft bearing 22B are both split-type bearings. Here, an example of using a tapered roller bearing as the split-type bearing is shown, but the specific example is not particularly limited, and an angular contact ball bearing or the like can also be used. In the case of a tapered roller bearing, the rolling element 50 is a tapered roller, and in the case of an angular contact ball bearing, the rolling element 50 is a sphere.

[0038] When constituting a separable bearing, the outer ring 54 does not include an inner movement limiting portion (flange portion) which is provided on the axial inner side relative to the rolling element 50 and limits the relative movement of the outer ring 54 toward the axial outer side relative to the rolling element 50. Thus, by moving the outer ring 54 relative to the rolling element 50 toward the axial outer side, the outer ring 54 can be separated from the rolling element 50 in the axial direction. Furthermore, when constituting a separable bearing, the inner ring 56 does not include an outer movement limiting portion (flange portion) which is provided on the axial outer side relative to the rolling element 50 and limits the relative movement of the rolling element 50 toward the axial outer side relative to the inner ring 56. Thus, by moving the rolling element 50 relative to the inner ring 56 toward the axial outer side, the rolling element 50 can be separated from the inner ring 56 in the axial direction. The conditions for separation of the components of such a separable bearing only need to be satisfied at least during the assembly process of the gear device 10.

[0039] The gear device 10 includes a limiting member 60 capable of limiting the axial movement of the rolling element 50 relative to the inner ring 56 of the first crankshaft bearing 22A. The limiting member 60 abuts against the rolling element 50 from the axial outer side, thereby limiting the axial movement of the rolling element 50. The condition of "limiting axial movement" is as long as Figure 4 The condition is satisfied only when the outer ring 54 of the first crankshaft bearing 22A is separated from the rolling element 50 during the assembly process of the gear device 10 shown. This is because, in this state, the axial movement of the rolling element 50 toward the axial outside relative to the inner ring 56 is allowed, thereby causing the rolling element 50 to be offset relative to the inner ring 56. This condition of "limiting axial movement" may not be satisfied when the gear device 10 is in operation after the gear device 10 is assembled.

[0040] The limiting component 60 is provided separately from the inner ring 56. The limiting component 60 of the present embodiment is mounted on the crankshaft 14 on the same side (here, the input side) as the crankshaft gear 26 in the axial direction of the eccentric portion 12 of the crankshaft 14. The limiting component 60 is in a shape that surrounds the crankshaft 14. As a shape that satisfies this condition, the limiting component 60 of the present embodiment is in a continuous ring shape around the entire circumference of the rotation center line C14 of the crankshaft 14. In addition, the limiting component 60 may also be in a notched ring shape with a portion of its circumference missing.

[0041] The restricting member 60 includes a hard component 62 mounted on the crankshaft 14 and a soft component 64 that is softer than the hard component 62. The material of the hard component 62 is preferably a metal-based material, but it may also be made of a resin-based material or the like. When the gear device 10 is operating, if the gear pair of the gear device 10 meshes and generates heat, the restricting member 60 may become high temperature based on heat conduction. Here, the gear pair refers to, for example, not only the combination of the crankshaft gear 26 and the drive gear 30, but also the combination of the oscillating gear 16 and the meshing gear 18. When a metal-based material is used as the material of the hard component 62, creep of the hard component 62 in a high-temperature environment can be suppressed compared to when a resin-based material is used, and loosening of the hard component 62 caused thereby can be suppressed.

[0042] The metal-based material here refers to a material mainly composed of metal (including alloys). In addition to the case of being composed only of metal, it also includes the case of being composed of a composite material of metal and other materials (for example, fiber-reinforced metal, etc.). The metals used here are, for example, iron-based materials such as cast iron and steel, and aluminum-based materials such as aluminum alloy. The resin-based material here refers to a material mainly composed of resin. In addition to the case of being composed only of resin, it also includes the case of being composed of a composite material of resin and other materials (for example, fiber-reinforced resin, etc.). The resins used here are, for example, plastic-based materials such as general engineering plastics and special engineering plastics.

[0043] The soft component 64 is made of a rubber material, a sponge material, a gel material, etc. that are softer than the hard component 62. The soft component 64 is provided at a portion of the hard component 62 that axially faces the crankshaft bearings 22A and 22B. As a portion that satisfies this condition, the soft component 64 of the present embodiment is provided at the first radially extending portion 68A (described later) of the hard component 62. When the soft component 64 is made of an elastic material such as a rubber material, it can be integrated with the hard component 62, for example, by bonding (such as vulcanization bonding).

[0044] The hard component 62 includes an axially extending portion 66 and radially extending portions 68A and 68B. The radially extending portions 68A and 68B include a first radially extending portion 68A that extends radially outward from the inner end portion of the axially extending portion 66 and a second radially extending portion 68B that extends radially inward from the outer end portion of the axially extending portion 66.

[0045] The axial extension 66 of the restricting member 60 (hard component 62) is fixed to the outer peripheral portion of the crankshaft 14 by an interference fit. Thereby, the restricting member 60 is detachably mounted on the crankshaft 14. Since the restricting member 60 is fixed by an interference fit, the restricting member 60 can be fixed even without forming a groove portion in the outer peripheral portion of the crankshaft 14. And, as will be described later, even without the crankshaft gear 26 that restricts the restricting member 60 from moving axially outward, the restricting member 60 can be fixed to the crankshaft 14, so there is also an advantage of improving the degree of assembly freedom.

[0046] The soft component 64 constitutes an abutting portion 70 against which the retainer 52 or the rolling element 50 of the first crankshaft bearing 22A can abut. The retainer 52 or the rolling element 50 abuts against the abutting portion 70, whereby the restricting member 60 can restrict the rolling element 50 from moving axially. Here, an example is shown in which the object directly abutted by the abutting portion 70 of the restricting member 60 is the retainer 52. The retainer 52 abuts against the abutting portion 70, whereby the movement of the retainer 52 axially outward is restricted, and the rolling element 50 abuts against the retainer 52, whereby the movement of the rolling element 50 axially outward is restricted. By forming the abutting portion 70 with the soft component 64, wear caused by sliding with the restricting member 60 can be suppressed as compared with the case where the retainer 52 or the rolling element 50 abuts against the hard component 62.

[0047] The second radial extension 68B of the hard component 62 constitutes a positioning portion 72 that is axially positioned with respect to the crankshaft 14. The positioning portion 72 abuts against a part of the crankshaft 14 from the axial outside, so as to be positioned with respect to the crankshaft 14. The "part of the crankshaft 14" here is a stepped portion 74 provided on the outer peripheral portion of the crankshaft 14 so as to protrude radially outward, but it may also be its end face portion. In the present embodiment, the stepped portion 74 is provided to protrude radially outward from the axial inner end of the convex spline portion formed by the coupling structure 36. In the present embodiment, the crankshaft gear 26 disposed axially outside the restricting member 60 restricts the restricting member 60 from moving axially outward. Through this positioning portion 72, the restricting member 60 can be restricted from moving axially toward the crankshaft bearings 22A, 22B side, and an axial gap 76 can be stably formed between the abutting portion 70 of the restricting member 60 and the crankshaft bearings 22A, 22B.

[0048] The axial clearance 76 is provided to prevent wear caused by sliding between the components (rolling elements 50, cage 52) of the first crankshaft bearing 22A that rotate relative to the crankshaft 14 and the restricting member 60. The axial clearance 76 is provided over the entire circumference around the rotational center line C14 of the crankshaft 14 between the first crankshaft bearing 22A and the restricting member 60. The axial dimension L76 of the axial clearance 76 is a size of 0 or more and is larger than the positive axial internal clearance of the first crankshaft bearing 22A. Here, the axial internal clearance refers to the amount of axial play of the rolling elements 50 relative to the outer ring 54 and the inner ring 56 of the first crankshaft bearing 22A. Here, an example where the axial internal clearance is zero is shown. The axial dimension L76 of the axial clearance 76 refers to the axial dimension of the portion with the smallest axial dimension between the first crankshaft bearing 22A and the restricting member 60.

[0049] In a state where the rolling elements 50 are in contact with the inner side movement restricting portion 56b in the inner ring 56 of the first crankshaft bearing 22A, the axial clearance 76 of the present embodiment is provided between the first crankshaft bearing 22A and the restricting member 60. In this state, in the present embodiment, a clearance 78 is provided between the outer side movement restricting portion 54b in the outer ring 54 of the first crankshaft bearing 22A and the rolling elements 50. The axial dimension L76 of the axial clearance 76 is larger than the minimum axial dimension L78 of this clearance 78.

[0050] By having such an axial gap 76, the restricting member 60 satisfies the position condition of being set at a position where it does not contact the retainer 52. This position condition is satisfied in the state where the gear device 10 is assembled. This position condition only needs to be satisfied in the state where the restricting member 60 is arranged downward with respect to the retainer 52. Consider the case where the retainer 52 is allowed to be axially displaced relative to the rolling elements 50. At this time, in terms of satisfying the above position condition, it is only necessary that the restricting member 60 is set at a position where it does not contact the retainer 52 when the retainer 52 is at the outermost axial position within the range where it can relatively move with respect to the rolling elements 50. And, in terms of satisfying this position condition, it is only necessary that the restricting member 60 is set at a position where it does not contact the retainer 52 that moves together with the rolling elements 50 when the rolling elements 50 are at the outermost axial position within the range where they can relatively move with respect to the crankshaft 14 and the first wheel carrier 24A. Regarding this "when the rolling elements 50 are at the outermost axial position within the range where they can relatively move", when the rolling elements 50 are tapered rollers, it can be the position where their outward axial movement is restricted by the tapered outer raceway surface 54a, or the position where their movement is restricted by the outer movement restricting portion 54b. In addition to this, regarding this "when the rolling elements 50 are at the outermost axial position within the range where they can relatively move", when the rolling elements 50 are cylindrical rollers, it can be the position where the outward axial movement of the rolling elements 50 is restricted by contacting a straight surface 77 that is continuous from the inner raceway surface 56a to the outside in the axial direction and extends along the axial direction. Thus, the outer movement restricting portion 54b of the outer ring 54 is not necessary.

[0051] The effects of the above gear device 10 will be described. When a separable bearing is used for the first crankshaft bearing 22A, during the assembly process of the gear device 10, when the rolling elements 50 and the outer ring 54 are in a separated state, the axial movement of the rolling elements 50 (rolling element unit 58) on the inner ring 56 is allowed. If this causes the rolling elements 50 on the inner ring 56 to be significantly axially displaced, it takes time to restore them to their original state. And, depending on the amount of displacement of the rolling element unit 58 including the rolling elements 50, the rolling element unit 58 may fall off from the crankshaft 14. Thus, due to the large displacement of the rolling elements 50 on the inner ring 56, there may be a problem of deteriorated operability during the assembly operation.

[0052] At this point, the gear device 10 of the present embodiment includes a restricting member 60 that can restrict the axial movement of the rolling elements 50 relative to the inner ring 56 of the first crankshaft bearing 22A. Therefore, during the assembly process of the gear device 10, even when the outer ring 54 is separated from the rolling elements 50, the restricting member 60 can be used to suppress large axial displacement of the rolling elements 50 on the inner ring 56. Furthermore, even when a separable bearing is used for the first crankshaft bearing 22A, by suppressing problems caused by the displacement of the rolling elements 50, good operability can be obtained in the assembly operation of the gear device 10.

[0053] Moreover, if the rolling elements 50 are significantly displaced from the predetermined positions on the inner ring 56 of the first crankshaft bearing 22A and the outer ring 54 is covered on the rolling elements 50 in this state, the raceway surfaces 54a, 56a of the outer ring 54 and the inner ring 56 may be damaged. Here, according to the present embodiment, since the restricting member 60 can suppress large displacement of the rolling elements 50, it is possible to avoid damage to the raceway surfaces 54a, 56a of the outer ring 54 and the inner ring 56 caused by this displacement.

[0054] The inner ring 56 of the crankshaft bearing 22A is integrally provided with the crankshaft 14 by the same component as the crankshaft 14. Thereby, the number of components around the crankshaft bearing 22A can be reduced, and thus a reduction in product cost can be achieved. And when the inner ring 56 is integrally provided with the crankshaft 14 by the same component as the crankshaft 14, if an outer movement restricting portion for restricting the axial outward movement of the rolling elements 50 relative to the inner ring 56 is directly formed on the crankshaft 14, the processing difficulty will increase. Here, according to the present embodiment, even if the outer movement restricting portion is not directly formed on the crankshaft 14, by installing the restricting member 60 on the crankshaft 14, the axial movement of the rolling elements 50 relative to the inner ring 56 can be restricted. Therefore, it is possible to restrict the axial movement of the rolling elements 50 relative to the inner ring 56 without increasing the processing difficulty of the crankshaft 14.

[0055] Next, an assembly method of the gear device 10 will be described. The assembly method of the gear device 10 mainly includes a restricting member assembly step S10 of assembling the restricting member 60 to the crankshaft 14 (refer to Figure 3 ) and a first assembly step S12 of assembling an output side bearing structure 80 (second bearing structure) including the crankshaft 14, the second crankshaft bearing 22B, and the second carrier 24B (refer to Figure 3 and Figure 4 ). In addition to this, the assembly method further includes a second assembly step S14 of assembling an input side bearing structure 82 (first bearing structure) including the crankshaft 14, the first crankshaft bearing 22A, and the first carrier 24A (refer to Figure 4 and Figure 5) and a gear assembly process S16 of assembling the crankshaft gear 26 onto the crankshaft 14 (refer to Figure 5 ).

[0056] Refer to Figure 3 . Hereinafter, in order to distinguish the common components (rolling elements 50, retainer 52, outer ring 54, and inner ring 56) between the first crankshaft bearing 22A and the second crankshaft bearing 22B, the components of the first crankshaft bearing 22A are labeled with "first", and the components of the second crankshaft bearing 22B are labeled with "second". In the restricting member assembly process S10, the rolling element unit 58 is pre-arranged on the inner raceway surface 56a of the first inner ring 56 of the first crankshaft bearing 22A integrated with the crankshaft 14, so as to assemble the first rolling element 50 onto the crankshaft 14. At this time, the rolling element unit 58 is relatively moved axially inward with respect to the crankshaft 14, so that the rolling element unit 58 is arranged on its first inner ring 56. In the restricting member assembly process S10, in a state where the rolling element 50 (rolling element unit 58) is assembled onto the crankshaft 14, the restricting member 60 that restricts the axial movement of the first rolling element 50 is fixed to the crankshaft 14, so as to assemble it onto the crankshaft 14. In the present embodiment, before and after the restricting member assembly process S10, a sub-assembly 84 formed by combining the swing gear 16, the meshing gear 18, the housing 20, and the eccentric bearing 38 is assembled onto the crankshaft 14. In subsequent processes, the crankshaft 14 represents the sub-assembly 84 on which the crankshaft 14 is assembled.

[0057] Refer to Figure 3 and Figure 4 . The first assembly process S12 is a process of assembling the output-side bearing structure 80 so that the crankshaft 14 is supported by the second wheel carrier 24B via the second crankshaft bearing 22B. After the first assembly process S12, a sub-assembly 84 assembled with the output-side bearing structure 80 can be obtained.

[0058] The first assembly process S12 of the present embodiment is performed in a state where the second wheel carrier 24B with the input side facing upward is placed on the workbench 86. At this time, by arranging the rolling element unit 58 on the outer raceway surface 54a of the second outer ring 54 of the second crankshaft bearing 22B integrated with the second wheel carrier 24B, the second rolling element 50 is pre-assembled onto the second wheel carrier 24B. In this state, the crankshaft 14 (sub-assembly 84) integrated with the second inner ring 56 of the second crankshaft bearing 22B is moved downward in the vertical direction, so that the output-side shaft portion 28B of the crankshaft 14 is inserted into the second shaft hole 24Ba of the second wheel carrier 24B. Thus, in a state where the first rolling element 50 and the restricting member 60 are assembled onto the crankshaft 14, the crankshaft 14 integrated with the second inner ring 56 is mounted on the second rolling element 50 assembled onto the second wheel carrier 24B. Thus, the output-side bearing structure 80 is assembled, and the first assembly process S12 is completed.

[0059] In the case where the second outer ring 54 of the second crankshaft bearing 22B and the second wheel carrier 24B are separately formed, the output side shaft portion 28B of the crankshaft 14 can be inserted in advance into the second shaft hole 24Ba of the second wheel carrier 24B that is not integrated with the second outer ring 54. Thereafter, the second outer ring 54 can be fitted into the second shaft hole 24Ba from the output side, so that the second outer ring 54 and the second wheel carrier 24B can be integrated. Thus, the output side bearing structure 80 is assembled, and the first assembly process S12 is completed. During the above-described first assembly process S12, the rolling elements 50 and the restricting members 60 are maintained in a state of being assembled to the crankshaft 14.

[0060] Reference Figure 4 and Figure 5 . The second assembly process S14 is a process of assembling the input side bearing structure 82 so that the first wheel carrier 24A is supported by the crankshaft 14 via the first crankshaft bearing 22A. By performing the second assembly process S14, a sub-assembly 84 having the input side bearing structure 82 assembled thereto can be obtained.

[0061] The second assembly process S14 of the present embodiment is performed in a state where the second wheel carrier 24B with the input side facing upward is placed on the workbench 86. At this time, as described above, the first rolling elements 50 of the first crankshaft bearing 22A are pre-assembled to the crankshaft 14. In this state, in the present embodiment, the first wheel carrier 24A integrated with the first outer ring 54 of the first crankshaft bearing 22A is moved downward in the vertical direction, so that the input side shaft portion 28A of the crankshaft 14 is inserted into the first shaft hole 24Aa of the first wheel carrier 24A. In the present embodiment, the crankshaft 14 is inserted into the first shaft hole 24Aa of the first wheel carrier 24A until the pin body 40 integrated with the second wheel carrier 24B abuts against the first wheel carrier 24A. Then, the fixing member 42 (reference Figure 1 ) is used and the pin body 40 is used to connect the first wheel carrier 24A and the second wheel carrier 24B. Thus, with the restricting members 60 assembled to the crankshaft 14, the first outer ring 54 of the first crankshaft bearing 22A is mounted on the first rolling elements 50 assembled to the crankshaft 14. Here, the first outer ring 54 integrated with the first wheel carrier 24A is mounted on the first rolling elements 50 assembled to the crankshaft 14. Thus, the input side bearing structure 82 is assembled, and the second assembly process S14 is completed.

[0062] When the first outer ring 54 of the first crankshaft bearing 22A is separately formed from the first carrier 24A, the first outer ring 54 can be pre-mounted on the first rolling elements 50 assembled to the crankshaft 14, and then the first carrier 24A and the first outer ring 54 can be integrated. At this time, the first outer ring 54 can be inserted into the first shaft hole 24Aa of the first carrier 24A to integrate the first carrier 24A and the first outer ring 54. In addition to this, the input-side shaft portion 28A of the crankshaft 14 can be pre-inserted into the first shaft hole 24Aa of the first carrier 24A that is not integrated with the first outer ring 54. After that, the first outer ring 54 can be fitted into the first shaft hole 24Aa of the first carrier 24A from the input side, so that the first outer ring 54 and the first carrier 24A can be integrated. Thus, the input-side bearing structure 82 is assembled, and the second assembly process S14 is completed. During the above second assembly process S14, the state where the rolling elements 50 and the restricting member 60 are assembled to the crankshaft 14 is maintained.

[0063] Reference Figure 5 。The gear assembly process S16 of the present embodiment is performed in a state where the second carrier 24B with the input side facing upward is placed on the workbench 86. In the gear assembly process S16, the input-side shaft portion 28A of the crankshaft 14 is inserted into the central hole 26a of the crankshaft gear 26. Then, the gear fixing member 34 is installed on the crankshaft gear 26 to fix the crankshaft gear 26 to the crankshaft 14. Thus, the gear assembly process S16 is completed.

[0064] Next, the effects of the above assembly method will be described. During the second assembly process S14, the first outer ring 54 and the first rolling elements 50 of the first crankshaft bearing 22A are in a separated state. At this time, the first rolling elements 50 (rolling element unit 58) can be largely displaced axially outward from the crankshaft 14. For example, when a part of a worker accidentally touches the first rolling elements 50 (rolling element unit 58). In the second assembly process S14 of the present embodiment, since the crankshaft 14 on which the restricting member 60 is assembled in addition to the first rolling elements 50 is used, the large displacement of the rolling elements 50 can be suppressed by the restricting member 60 during the second assembly process S14.

[0065] As Figure 3As shown, when the output side shaft portion 28B of the crankshaft 14 is inserted into the second shaft hole 24Ba of the second wheel carrier 24B placed on the workbench 86, the second rolling elements 50 of the second crankshaft bearing 22B are assembled on the second wheel carrier 24B. The axial position of the rolling elements 50 is restricted by the outer side movement restricting portion 54b of the second outer ring 54 of the second crankshaft bearing 22B integrated with the second wheel carrier 24B placed on the workbench 86. Therefore, even if a separable bearing is used for the second crankshaft bearing 22B, during the process of performing the first assembling step S12, it is not easy to cause the problem of misalignment of the second rolling elements 50, and there is no need for a restricting member 60 for suppressing such misalignment.

[0066] In contrast, during the process of moving the crankshaft 14 in the first assembling step S12, the first rolling elements 50 of the first crankshaft bearing 22A assembled on the input side shaft portion 28A of the crankshaft 14 are liable to be misaligned relative to the crankshaft 14. Here, in the present embodiment, in the first assembling step S12, the crankshaft 14 on which, in addition to the first rolling elements 50 of the first crankshaft bearing 22A, a restricting member 60 is also assembled, is used. Therefore, in the first assembling step S12 where misalignment of the first rolling elements 50 of the first crankshaft bearing 22A is liable to be a problem, the large misalignment can be suppressed by the restricting member 60, which is advantageous.

[0067] Assume that the second assembling step S14 → the first assembling step S12 → the gear assembling step S16 are performed in sequence. At this time, in the second assembling step S14, when moving the crankshaft 14 on which the second rolling elements 50 separated from the second outer ring 54 of the second crankshaft bearing 22B are assembled, it is easy to cause the problem of misalignment of the second rolling elements 50 relative to the crankshaft 14. At this time, in the second assembling step S14 and the first assembling step S12, the operation is performed in a state where the first wheel carrier 24A with the output side facing upward is placed on the workbench 86. Then, in the gear assembling step S16, in order to place the second wheel carrier 24B with the input side facing upward on the workbench 86, it is necessary to turn the sub-assembly 84 upside down. Here, as a countermeasure against the misalignment of the second rolling elements 50 of the second crankshaft bearing 22B relative to the crankshaft 14 in the second assembling step S14, it can be considered to assemble a restricting member 60 for restricting the misalignment of the second rolling elements 50 on the crankshaft 14. At this time, in the second assembling step S14 where misalignment of the rolling elements 50 relative to the crankshaft 14 is liable to be a problem, although the large misalignment can be suppressed by the restricting member 60, there will be a problem that the sub-assembly 84 needs to be turned upside down.

[0068] In contrast, consider a case where the first assembly process S12 → the second assembly process S14 → the gear assembly process S18 are performed in sequence as in the present embodiment. At this time, in the first assembly process S12, when moving the crankshaft 14 with the first rolling elements 50 separated from the first outer ring 54 of the first crankshaft bearing 22A assembled thereon, the problem of displacement of the first rolling elements 50 is likely to occur. At this time, as described above, in the process of performing the first assembly process S12 → the second assembly process S14 → the gear assembly process S16, the orientation of the sub-assembly 84 can be maintained without inverting the sub-assembly 84 upside down. Therefore, in the first assembly process S12 where displacement of the first rolling elements 50 relative to the crankshaft 14 is likely to be a problem, while suppressing such large displacement using the restricting member 60, without inverting the sub-assembly 84 upside down, particularly good operability can be obtained in the assembly operation.

[0069] The above effects are obtained by satisfying the following first condition and second condition. The first condition means that when fixing the crankshaft gear 26 to the input side shaft portion 28A of the crankshaft 14, the restricting member 60 is installed on the input side shaft portion 28A of the crankshaft 14 that is on the same side as the crankshaft gear 26 in the axial direction with respect to the eccentric portion 12 of the crankshaft 14. The second condition means that during the assembly of the gear device 10, when sequentially performing the first assembly process S12 → the second assembly process S14, the first rolling elements 50 of the first crankshaft bearing 22A and the restricting member 60 are pre-assembled to the input side shaft portion 28A of the crankshaft 14 in the first assembly process S12. It can be understood that as long as the first condition related to the structure of the gear device 10 is satisfied, the above effects can be obtained when the second condition related to the assembly method of the gear device 10 is satisfied.

[0070] Other features of the gear device 10 will be described. Refer to Figure 1 An input side member 90 is installed on the gear device 10 and is disposed on the input side with respect to the gear device 10. The input side member 90 is, for example, a connector that connects the gear device 10 and a drive source. At least a part of an enclosure space 92 for enclosing a lubricant is provided inside the gear device 10. The enclosure space 92 of the present embodiment is formed by being surrounded by the gear device 10 and the input side member 90.

[0071] Refer to Figure 2 An outer channel 94 is formed axially outside the first crankshaft bearing 22A between the first shaft hole 24Aa of the first wheel carrier 24A and the crankshaft 14. Among the lubricants that are to flow axially inward into the outer channel 94, there may be contaminants generated in the enclosure space 92. Such contaminants are generated, for example, due to the meshing of the crankshaft gear 26 and the transmission gear 30.

[0072] The first radially extending portion 68A of the restricting member 60 is restricted from protruding from the outer peripheral portion side of the crankshaft 14 toward the first shaft hole 24Aa side of the first wheel carrier 24A, thereby forming a labyrinth seal that locally narrows the radial dimension of the outer passage 94. Here, an example of a so-called straight-through labyrinth seal is shown in which a part forming the labyrinth seal protrudes only from a portion radially opposed to the outer passage 94. Thus, the inflow of contaminants toward the first crankshaft bearing 22A side in the outer passage 94 is blocked by the first radially extending portion 68A of the restricting member 60, which is advantageous for extending the life of the first crankshaft bearing 22A. From the viewpoint of effectively blocking the inflow of contaminants, the first radially extending portion 68A of the restricting member 60 preferably has a continuous annular shape extending over the entire circumference around the rotation center line C14 of the crankshaft 14. Also, from the same viewpoint, the first radially extending portion 68A of the restricting member 60 preferably protrudes to a position axially overlapping with the axially outer end portion 52a of the retainer 52, and more preferably protrudes radially outward beyond the outer end portion 52a.

[0073] (Second Embodiment)

[0074] Reference Figure 6 The method of assembling the gear device 10 of the present embodiment differs from that of the first embodiment in that, in addition to including the above-described first assembling step S12, second assembling step S14, and gear assembling step S16, it further includes a disassembling step S18 of disassembling the restricting member 60 from the crankshaft 14. The disassembling step S18 is performed during the period from after the second assembling step S14 to before the gear assembling step S16. The restricting member 60 is disassembled from the crankshaft 14 by moving the restricting member 60 axially outward relative to the crankshaft 14. Thus, even if the restricting member 60 is disassembled, the input-side bearing structure 82 including the first wheel carrier 24A, the first crankshaft bearing 22A, and the crankshaft 14 has already been assembled in the second assembling step S14. Therefore, the axial movement of the rolling elements 50 of the first crankshaft bearing 22A axially outward is restricted by the inner ring 56, and the rolling elements 50 do not deviate axially outward from the inner ring 56. Therefore, while large deviation of the rolling elements 50 on the inner ring 56 during assembly can be suppressed, the structure of the gear device 10 can be simplified. Also, with respect to the restricting member 60, a structure that only needs to withstand restricting the axial movement of the rolling elements 50 during assembly can be adopted, and thus the structure can be simplified.

[0075] (Third Embodiment)

[0076] Reference Figure 7The difference between the gear device 10 of the present embodiment and the gear device 10 of the first embodiment is that it includes a clearance forming member 100 mounted on the first wheel carrier 24A. The clearance forming member 100 of the present embodiment includes an axially extending portion 102 fixed to the axially extending hole 24Aa of the first wheel carrier 24A by interference fit and a radially extending portion 104 protruding radially inward from the axially extending portion 66. The radially extending portion 104 of the clearance forming member 100 protrudes from the side of the axially extending hole 24Aa of the first wheel carrier 24A toward the outer peripheral portion side of the crankshaft 14.

[0077] The clearance forming member 100 cooperates with the restricting member 60 to form a labyrinth clearance 106 in the outer passage 94. The labyrinth clearance 106 is formed in the outer passage 94 to be radially zigzag and axially inward as it approaches the first crankshaft bearing 22A side. In achieving this, the labyrinth clearance 106 includes a radial clearance 106a and an axial clearance 106b that are alternately arranged in the outer passage 94 toward the first crankshaft bearing 22A side.

[0078] The radial clearance 106a is formed to extend axially. The radial clearance 106a is formed between the portion (here, the axially extending portion 66 of the restricting member 60) that is radially opposed to the radially extending portion 104 of the clearance forming member 100 and the radially extending portion 104 of the clearance forming member 100. In addition, the radial clearance 106a is also formed between the portion (here, the axially extending portion 102 of the clearance forming member 100) that is radially opposed to the first radially extending portion 68A of the restricting member 60 and the first radially extending portion 68A of the restricting member 60. The axial clearance 106b is formed to extend radially. The axial clearance 106b is formed between the radially extending portion 104 of the clearance forming member 100 and the first radially extending portion 68A of the restricting member 60. By forming such a labyrinth clearance 106, the inflow of contaminants into the first crankshaft bearing 22A side through the outer passage 94 can be significantly reduced.

[0079] Next, a modified example of the above gear device will be described.

[0080] As a specific type of the eccentric swing type gear device, the distribution type has been exemplified above. Its type is not particularly limited. For example, it may also be a center crank type in which the crankshaft 14 is disposed on the swing center C16A of the swing gear 16. In this case, the crankshaft 14 may also be an input member.

[0081] The housing 20 can also be used as the output member instead of the wheel carriers 24A and 24B. The internal gear can be used as the oscillating gear 16 instead of the external gear, and the external gear can be used as the meshing gear 18 instead of the internal gear. The gear device 10 can also function as a speed increasing device. In this case, the wheel carriers 24A and 24B or the housing 20 can be used as the input member instead of the crankshaft gear 26 (crankshaft 14), and the crankshaft gear 26 (crankshaft 14) can be used as the output member instead of the wheel carriers 24A and 24B or the housing 20.

[0082] So far, the case where the crankshaft bearings 22A and 22B are separable bearings in which both the outer ring 54 and the inner ring 56 are axially separable relative to the rolling elements 50 has been described by way of example. When the crankshaft bearings 22A and 22B are separable bearings, at least the inner ring 56 is axially separable relative to the rolling elements 50. The outer ring 54 is not limited to being axially separable relative to the rolling elements 50, but may also be radially separable.

[0083] The restricting member 60 can also be mounted on the crankshaft 14 on the side opposite to the crankshaft gear 26 in the axial direction of the eccentric portion 12 of the crankshaft 14. In this case, in the embodiment, the restricting member 60 can restrict the axial movement of the rolling elements 50 relative to the inner ring 56 of the second crankshaft bearing 22B. Also, the restricting member 60 can be provided corresponding to the first crankshaft bearing 22A and the second crankshaft bearing 22B, respectively. In this case, each restricting member 60 is provided to restrict the axial movement of the rolling elements 50 of the corresponding crankshaft bearings 22A and 22B.

[0084] So far, the case where the restricting member 60 includes the hard component 62 and the soft component 64 has been described by way of example, but it may only include the hard component 62. In this case, the abutting portion 70 of the restricting member 60 can be provided on the hard component 62.

[0085] The specific method for mounting the restricting member 60 on the crankshaft 14 is not particularly limited. The restricting member 60 can also be installed on the crankshaft 14 by being fitted into a groove provided in the outer peripheral portion of the crankshaft 14. In this case, the restricting member 60 only needs to be fitted into the crankshaft 14 by clearance fit, interference fit, etc.

[0086] The specific shape of the restricting member 60 is not particularly limited. For example, the restricting member 60 may not have a positioning portion 72 for being positioned relative to the crankshaft 14. Also, the position of the positioning portion 72 of the restricting member 60 is not particularly limited. For example, in the case where the restricting member 60 is formed of a snap ring, the inner peripheral end portion thereof can also form the positioning portion 72.

[0087] An axial clearance 76 may not be provided between the first crankshaft bearing 22A and the restricting member 60.

[0088] It is also possible to omit the second wheel carrier 24B among the first wheel carrier 24A and the second wheel carrier 24B. At this time, in the above assembly method, only the second assembly process S14 among the first assembly process S12 and the second assembly process S14 needs to be performed. Moreover, when the eccentric swing type gear device is a center crank type without the crankshaft gear 26, there is no gear assembly process S16 in the above assembly method.

[0089] The rolling element 50 and the restricting member 60 of the first crankshaft bearing 22 may be assembled to the crankshaft 14 in the restricting member assembly process S10 as long as it is performed before the second assembly process S14. Above, as an example, the case where the restricting member assembly process S10 is performed before the first assembly process S12 has been described, but it may also be performed during the period after the first assembly process S12 and before the second assembly process S14.

[0090] In the embodiment, the case where the first assembly process S12 → the second assembly process S14 are performed in sequence has been described as an example, but the second assembly process S14 → the first assembly process S12 may also be performed in sequence. At this time, in the second assembly process S14, after placing the first wheel carrier 24A with the output side facing upward on the workbench 86, the rolling element unit 58 may be disposed on the outer ring 54 of the first crankshaft bearing 22A integrated with the first wheel carrier 24A, so that the rolling element 50 is assembled to the first wheel carrier 24A. Moreover, at this time, in the second insertion process S14A of the second assembly process S14, the crankshaft 14 integrated with the inner ring 56 of the first crankshaft bearing 22 may be moved downward in the vertical direction in this state, so that the input side shaft portion 28A of the crankshaft 14 is inserted into the first shaft hole 24Aa.

[0091] The above embodiments and modification examples are for illustration. These abstract technical ideas should not be interpreted restrictively as the content of the embodiments and modification examples. Regarding the content of the embodiments and modification examples, various design changes such as changes, additions, and deletions of constituent elements can be made. In the above embodiments, regarding the content that allows such design changes, the mark of "embodiment" is emphasized. However, it does not mean that the content without such a mark is not allowed to be designed and changed. The hatching marked in the cross-section of the drawings is not used to limit the material of the object marked with hatching. The structures and numerical values mentioned in the embodiments and modification examples naturally include structures and numerical values that can be regarded as the same considering manufacturing errors and the like. A constituent element that is composed of one component in the embodiment may also be composed of multiple components. Similarly, a constituent element that is composed of multiple components in the embodiment may also be composed of one component.

Claims

1. An eccentric swing type gear device, characterized in that: have: a crankshaft having an eccentric portion; and a crankshaft bearing supporting the crankshaft at a position offset in the axial direction relative to the eccentric portion, The crankshaft bearing is a separable bearing whose inner ring is axially separable from the rolling element. The eccentric oscillating gear device includes a restricting member capable of restricting the rolling element from moving in the axial direction relative to the inner ring in a state where the outer ring of the crank bearing is separated from the rolling element.

2. The eccentric oscillating gear device according to claim 1, characterized in that: The inner ring is formed as a single unit with the crankshaft by using the same component as the crankshaft.

3. The eccentric oscillating gear device according to claim 1, characterized in that: A crankshaft gear fixed to the crankshaft is provided, The restriction member is mounted on the same side of the crankshaft as the crank gear in the axial direction with respect to the eccentric portion.

4. The eccentric oscillating gear device according to claim 1, characterized in that: The restricting member is provided at a position where the restricting member does not come into contact with a retainer that retains a rolling element of the crankshaft bearing in a state in which the eccentric oscillating gear device is assembled.

5. The eccentric oscillating gear device according to claim 1, characterized in that: The limiting component comprises: an abutment portion capable of abutting against a retainer of the crankshaft bearing or the rolling element; and The positioning portion is positioned in the axial direction relative to the crankshaft.

6. The eccentric oscillating gear device according to claim 5, characterized in that: The restriction member is fixed to the crankshaft by interference fit.

7. The eccentric oscillating gear device according to claim 1, characterized in that: The limiting member includes a contact portion capable of contacting the retainer of the crankshaft bearing or the rolling element. The limiting member includes a hard component mounted on the crankshaft and a soft component softer than the hard component. The abutting portion is formed by the soft component.

8. A method for assembling an eccentric oscillating gear device, the eccentric oscillating gear device comprising: A crankshaft having an eccentric portion; a first crankshaft bearing supporting the crankshaft at a position offset in the axial direction relative to the eccentric portion; and a first wheel carrier, supporting the first crankshaft bearing, The first crankshaft bearing is a separable bearing in which the first inner ring is axially separable from the first rolling element. The assembly method of the eccentric oscillating gear device is characterized by comprising the following steps: a limiting member assembling step of assembling the first rolling element and a limiting member capable of limiting axial movement of the first rolling element relative to the first inner ring on the crankshaft integrated with the first inner ring; and an assembling step of assembling a first bearing structure including the crankshaft, the first crankshaft bearing and the first wheel carrier, The assembling step is performed after the restricting member assembling step, and the first outer ring of the first crankshaft bearing is mounted on the first rolling element assembled on the crankshaft in a state where the restricting member is assembled on the crankshaft.

9. The method for assembling an eccentric oscillating gear device according to claim 8, characterized in that: The method further includes a disassembly step of disassembling the restriction member from the crankshaft after the assembling step.

10. The method for assembling an eccentric oscillating gear device according to claim 8, characterized in that: The eccentric oscillating gear device further comprises: a second crankshaft bearing supporting the crankshaft at a position offset from the eccentric portion in an axial direction opposite to the first crankshaft bearing; and a second wheel carrier, supporting the second crankshaft bearing, The assembling method of the eccentric oscillating gear device further includes another assembling step, which is performed before the assembling step and assembles a second bearing structure including the crankshaft, the second crankshaft bearing and the second wheel carrier. The other assembly process is performed after the limiting component assembly process, and the crankshaft assembled with the first rolling element and the limiting component and integrated with the second inner ring of the second crankshaft bearing is installed on the second rolling element of the second crankshaft bearing assembled on the second wheel frame.

Images