TWI698599B - Eccentric oscillating gear device and manufacturing method thereof - Google Patents

Abstract

The invention provides an eccentric swing type gear device capable of increasing the load capacity of a journal bearing and a manufacturing method thereof. The eccentric oscillating gear device (1) includes: a housing (10) with internal teeth (12) on the inner periphery; a gear carrier (20) that is freely rotatably held in the housing (10); The crankshaft (30) holding the gear carrier (20); the swing gear (40), which is held on the crankshaft (30), and has external teeth (42) meshing with the internal teeth (12), using the crankshaft ( 30) Perform swing. The journal bearings (31a, 31b) of the crankshaft (30) are held on the gear carrier (20) via journal bearings (51, 52). The eccentric bodies (32a, 32b) of the crankshaft (30) are held on the swing gear (40) via bearings (61, 62) for eccentric bodies. The outermost radius (Rj) of the rolling elements (51C, 52C) of the journal bearings (51, 52) will be from the central axis of the crankshaft (30) to the anti-eccentric part of the eccentric body (32a, 32b). The distance and the thickness of the bearing (61, 62) for the eccentric body inserted into the eccentric body are added together to obtain a large summed distance (Rc).

Description

Eccentric swing type gear device and manufacturing method thereof

The present invention relates to an eccentric swing type gear device and a manufacturing method thereof.

For an eccentric oscillating gear device including a housing with internal teeth on the inner peripheral side and a oscillating gear with external teeth meshing with the internal teeth, there is an eccentric oscillating gear device having the following structure: The inner teeth of the casing are meshed while swinging and rotating, and with the swinging and rotating of the swinging gear, the gear frame supported by the casing rotates freely.

In this type of gear device, the rotation of the housing is restricted. A crankshaft is supported on the gear frame, and the crankshaft supports the swing gear. An eccentric body is provided on the crankshaft, and the eccentric body is matched with the through hole provided in the swing gear. As the eccentric body rotates, the oscillating gear oscillates while its external teeth mesh with the internal teeth of the housing. The rotation of the swing gear is transmitted through the crankshaft gear carrier. Thereby, the carrier rotates (for example, refer to Patent Document 1 and Patent Document 2).

As shown in Patent Document 1 and Patent Document 2, in this type of gear device, there are cases where the gear carrier includes a base portion having a disc shape and a base portion protruding from a shaft portion provided on one surface of the base portion. A disc-shaped end plate that is fastened against the top end of the shaft of the base.

In this type of structure, usually, the shaft and the end plate are fastened by bolts. In addition, the journal on the one end side of the crankshaft is rotatably held in the through hole formed in the base plate via the journal bearing, and the journal on the other end of the crankshaft is rotatably held on the end plate via the journal bearing. Department of the through hole. As journal bearings, tapered roller bearings are generally used.

A tapered roller bearing has: an inner ring; an outer ring; a plurality of rolling elements in a tapered shape held between the inner ring and the outer ring; and a retainer that holds the plurality of rolling elements arranged at predetermined intervals. In this type of tapered roller bearing, usually, the outer ring is configured to be freely separated from the rolling elements. On the other hand, in the state where the outer ring is separated in this way, the retainer and the rolling elements held on the retainer are usually kept in a state of being attached to the inner ring. Specifically, flanges are formed at one end and the other end in the axial direction of the inner ring, respectively, and the rolling elements are sandwiched between these flanges. Thus, the retainer and the rolling elements retained in the retainer are maintained in a state of being mounted on the inner ring.

In addition, the swing gear is arranged between the above-mentioned base plate portion and the end plate portion, between which the eccentric body of the crankshaft is inserted into the through hole of the swing gear. Generally, a bearing for the eccentric body is arranged between the eccentric body and the through hole of the swing gear. As bearings for eccentric bodies, cylindrical roller bearings are generally used.

As disclosed in Patent Document 1 and Patent Document 2, in this type of gear device, there are cases where the eccentric body of the crankshaft is composed of two eccentric bodies, and two swing gears are provided. In this case, one eccentric body of the two eccentric bodies is rotatably held by one of the two swing gears via the eccentric body bearing. The other eccentric body of the two eccentric bodies is rotatably held in the other gear of the two swing gears via the eccentric body with a bearing.

Prior art literature Patent literature

Patent Document 1: Japanese Patent Publication No. 2 013-185631

Patent Document 2: Japanese Patent Publication No. 014-190451

However, as disclosed in Patent Document 1 and Patent Document 2, in conventional gear devices of this type, the reverse deviation from the central axis of the crankshaft to the eccentric body arranged on the end plate side The distance between the center side portion and the thickness dimension of the bearing for the eccentric body inserted into the eccentric body are added to obtain the added distance ratio. The rolling element of the journal bearing arranged between the through hole of the end plate and the journal of the crankshaft The outermost circumference has a large radius. In addition, the anti-eccentric side portion is a portion of the eccentric body on the side opposite to the eccentric side portion, that is, the portion protruding outward in the radial direction.

Fig. 5 shows a diagram illustrating the above-mentioned dimensional relationship of a conventional gear device. In FIG. 5, reference numeral 100 denotes a gear carrier, and shows a state before the base portion 101 and the end plate portion 102 of the gear carrier 100 are fastened. Reference numeral 110 denotes a crankshaft. The crankshaft 110 has two eccentric bodies 111a and 111b, and the eccentric body 111b is arranged on the side of the end plate 102. A cylindrical roller bearing 112 as a bearing for the eccentric body is inserted into the eccentric body 111b. In addition, in FIG. 5, a tapered roller bearing 114b as a journal bearing with the outer ring separated is inserted into the journal 113b adjacent to the eccentric body 111b in the crankshaft 110. That is, in FIG. 5, a state where the inner ring of the tapered roller bearing 114b is inserted into the journal 113b and the retainer is held on the inner ring and the rolling elements held by the retainer are shown.

In FIG. 5, the reference sign Rc' represents the distance from the central axis of the crankshaft 110 to the anti-eccentric side portion of the eccentric body 111b arranged on the end plate portion 102 side and the cylindrical roller bearing inserted into the eccentric body 111b (eccentric The thickness dimension of the body bearing) 112 is added to obtain the added distance. In addition, the reference sign Rj' denotes the outermost peripheral radius of the rolling element of the tapered roller bearing (journal bearing) 114b arranged between the through hole of the end plate 102 and the journal 113b of the crankshaft 110. According to the figure, it is clear that the addition distance Rc' is larger than the outermost radius Rj' of the rolling element.

As shown in Figure 5, in the structure with this dimensional relationship, the cylindrical roller bearing 112 can be inserted into the inner ring held in the eccentric body 111b of the crankshaft 110 and the rolling elements of the tapered roller bearing 114b can be retained. Insert the journal 113b of the crankshaft 110. In this state, as shown by the arrow in the figure, the swing gear 120 having the through hole for inserting the eccentric body 111b is passed through the rolling elements of the tapered roller bearing 114b, so that the cylindrical roller bearing 112 can be inserted into the swing gear 120的through hole. After that, the outer ring can be mounted on the rolling elements of the tapered roller bearing 114b. By being able to execute the assembly sequence explained above, the Line assembly.

However, this structure can obtain advantages in assembling operations, but the radial dimension of the tapered roller bearing 114b as a journal bearing is restricted, thereby restricting the increase in the load capacity of the bearing. The increase in the load capacity of the journal bearing is expected, for example, when the eccentricity of the eccentric body of the crankshaft is increased. That is, when the eccentricity of the eccentric body of the crankshaft is increased, the force in the radial direction and the thrust direction transmitted from the crankshaft to the carrier increases. Therefore, in order to properly maintain the crankshaft, it is expected that the load capacity of the journal bearing will increase.

The present invention was made in consideration of the above-mentioned actual situation, and aims to provide an eccentric oscillating gear device and a manufacturing method thereof that can increase the load capacity of a journal bearing disposed between the journal bearing of the crankshaft and the carrier.

The present invention is an eccentric oscillating gear device. The eccentric oscillating gear device includes: a housing with internal teeth on the inner peripheral side; a gear holder rotatably held in the housing; and a gear holder rotatably held in the gear holder The crankshaft; and a swing gear, which is held on the crankshaft and has external teeth meshing with the internal teeth, swings by the crankshaft, the crankshaft has a journal and an eccentric body disposed adjacent to the journal, in A through hole for inserting the shaft portion is formed in the gear carrier, and a journal bearing is arranged between the through hole of the gear carrier and the shaft portion, and the journal bearing is rotatably held by the journal bearing via the journal bearing. In the gear carrier, a through hole for inserting the eccentric body is formed in the swing gear, a bearing for the eccentric body is arranged between the through hole of the swing gear and the eccentric body, and the eccentric body is free to rotate via the bearing for the eccentric body The ratio of the outermost circumference radius of the rolling element of the journal bearing to the anti-eccentric side portion of the eccentric body from the central axis of the crankshaft and the thickness of the bearing for the eccentric body inserted into the eccentric body The addition distance obtained by adding the dimensions is large.

According to the eccentric oscillating gear device of the present invention, the radial dimension of the journal bearing is increased plus. Thereby, the load capacity of the journal bearing arranged between the journal bearing of the crankshaft and the carrier can be increased.

In the above-mentioned eccentric swing type gear device, a transmission gear may be provided on a part of the journal part on the side opposite to the eccentric body side.

According to this structure, the transmission gear is supported by the journal bearing after the load capacity is increased. Thus, the supporting rigidity of the transmission gear can be largely ensured.

In addition, in the above-mentioned eccentric swing type gear device, the above-mentioned journal bearing may be a tapered roller bearing.

According to this structure, the tapered roller bearing supports the crankshaft from the axial direction. As a result, the movement of the crankshaft in the axial direction can be restricted.

In addition, in the eccentric oscillating gear device, the journal bearing may have: an inner ring mounted on the journal neck portion; an outer ring mounted on the through hole of the gear carrier; A rolling element group of a plurality of rolling elements between the ring and the outer ring, and the journal bearing is configured such that the rolling element group can be freely separated from the inner ring.

According to this structure, in the journal bearing, the rolling element group can be detached freely from the inner ring, and therefore, the variation of the assembly sequence increases. As a result, the assemblability of the gear device can be improved.

In addition, in the above-mentioned eccentric oscillating gear device, it is also possible that the outermost circumference radius of the inner ring of the journal bearing is smaller than the summed distance.

In addition, the present invention is a method of manufacturing an eccentric oscillating gear device. The eccentric oscillating gear device includes: a housing with internal teeth on the inner peripheral side; a gear carrier rotatably held in the housing; and rotatably held A crankshaft in the gear carrier; and a swing gear, which is held on the crankshaft, has external teeth meshing with the internal teeth, and is oscillated by the crankshaft. The manufacturing method of the eccentric swing type gear device includes the following steps: The process of installing the bearing for the eccentric body in the eccentric body of the crankshaft; The process of installing the inner ring of the bearing on the shaft neck of the crankshaft; moving the swing gear from the shaft neck side to the eccentric body side by passing the inner ring through the through hole formed in the swing gear The process of inserting the bearing for the eccentric body installed in the eccentric body into the through hole; the process of assembling the rolling element group and the outer ring to the inner ring.

According to the manufacturing method of the present invention, in the eccentric oscillating gear device, even the ratio of the outermost circumference radius of the rolling element of the journal bearing is the distance from the central axis of the crankshaft to the part of the anti-eccentric side of the eccentric body and that of the eccentric body When the thickness dimension of the bearing for eccentric body is added and the added distance is large, the gear device can be manufactured efficiently. Therefore, it is possible to efficiently manufacture a gear device capable of increasing the load capacity of the journal bearing disposed between the journal bearing of the crankshaft and the gear carrier.

According to the present invention, it is possible to provide an eccentric swing type gear device capable of increasing the load capacity of the journal bearing arranged between the journal bearing of the crankshaft and the gear carrier.

1: Eccentric swing type gear device

10: Shell

11: Shell body

12: Internal teeth

13: pin groove

20: Gear frame

21: Board Department

22: Shaft

23: base

24: End plate

25: Bolt

26: main bearing

27: Through hole for the first journal

28: Through hole for the second journal

29a: first retaining ring

29b: second retaining ring

30: crankshaft

31: Shaft body

31a: first journal

31b: second journal

32a: The first eccentric body

32b: second eccentric body

33: Spur gear

36a: eccentric side part

36b: Anti-eccentric side part

38a: eccentric side part

38b: Anti-eccentric side part

40: swing gear

40a: The first swing gear

40b: Second swing gear

42: External tooth

42a: First external tooth

42b: second external tooth

44a: Through hole for the first eccentric body

44b: Through hole for the second eccentric body

45a: Through hole for the first shaft

45b: Through hole for the second shaft

51: The first journal bearing

51A: inner circle

51B: Outer ring

51C: rolling element

51D: Retainer

51E: rolling element group

52: The second journal bearing

52A: inner circle

52B: Outer ring

52C: rolling element

52D: Retainer

52E: Rolling element group

52F: Flange

61: Bearing for the first eccentric body

61A: rolling element

61B: retainer

62: Bearing for the second eccentric body

62A: rolling element

62B: Retainer

100: Reference number/gear carrier

101: base

102: End plate

110: Reference number / crankshaft

111a: eccentric body

111b: eccentric body

112: Cylindrical roller bearing

113b: journal

114b: Tapered roller bearing

120: swing gear

ac: central axis

aca: reference number/central axis

acb: reference number/central axis

L1: Central axis

Rc: Adding distance

Rc': Adding distance

Rir: the outermost radius of the inner ring

Rj: The outermost radius of the rolling element

Rj': the outermost radius of the rolling element

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

2(A) and (B) are diagrams schematically showing the journal bearings of the eccentric swing type gear device of FIG. 1. FIG.

Fig. 3 is a diagram illustrating a method of manufacturing the eccentric oscillating gear device of Fig. 1;

Fig. 4 is a diagram illustrating a method of manufacturing the eccentric oscillating gear device of Fig. 1;

Fig. 5 is a diagram illustrating the dimensional relationship of a conventional eccentric oscillating gear device.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

(Structure of eccentric swing gear device)

The eccentric swing type gear device 1 of the present embodiment shown in FIG. 1 (hereinafter referred to as the gear device 1) includes: a housing 10 having internal teeth 12 on the inner peripheral side; 20; the crankshaft 30 held in the gear carrier 20 freely rotating; and the swing gear 40, which is held on the crankshaft 30, and has external teeth 42 meshing with the internal teeth 12, and is oscillated by the crankshaft 30.

The casing 10 has a casing main body 11 formed in a cylindrical shape with open ends. The above-mentioned internal teeth 12 are provided on the inner peripheral surface of the casing body 11. In the figure, the reference sign L1 denotes the center axis of the housing body 11, and in detail denotes the center axis of the inner peripheral surface of the housing body 11 provided with the internal teeth 12. Hereinafter, when only denoted as the "axial direction", the direction refers to a direction extending on the central axis L1 or a direction parallel to the central axis L1. In addition, the direction orthogonal to the center axis L1 is called the radial direction, and the direction around the center axis L1 is called the circumferential direction.

The internal teeth 12 are formed in a pin shape, and the internal teeth 12 are fitted and installed in the pin grooves 13 which are arranged along the circumferential direction in as many as those formed in the entire area of the inner peripheral surface of the housing body 11. The internal teeth 12 are arranged such that the longitudinal direction thereof is parallel to the direction of the central axis L1. The internal teeth 12 are configured to be arranged at equal intervals in the circumferential direction on the inner peripheral surface of the housing body 11 and mesh with the external teeth 42 of the above-mentioned swing gear 40.

The gear frame 20 includes a base 23 having a disc-shaped base 21 and a shaft 22 protrudingly provided on one surface of the base 21; and is fastened in a state of abutting against the top end of the shaft 22 of the base 23 The end plate portion 24 of a circular plate shape. A plurality of shaft portions 22 are formed in a state of being arranged along the circumferential direction. The end plate portion 24 abuts on the top end of each shaft portion 22 and is fastened to each shaft portion 22. In the example shown in the figure, the end plate portion 24 and the shaft portion 22 are fastened by bolts 25 that straddle the end plate portion 24 and the shaft portion 22.

The carrier 20 is rotatably supported on the inner peripheral surface of the housing body 11 via a pair of main bearings 26 arranged on the outer peripheral side of the base plate portion 21 and the outer peripheral side of the end plate portion 24. Thereby, the carrier 20 can rotate freely with respect to the housing 10 about the center axis L1 as a center. In this embodiment, the main bearing 26 is constituted by an angular contact ball bearing.

The crankshaft 30 includes: a shaft main body 31 having a central axis; two eccentric bodies, namely a first eccentric body 32a and a second eccentric body 32b; and a spur gear 33 as a transmission gear. In the shaft main body 31, a first journal portion 31a is formed on one end side (base plate portion 21 side), and on the other end side (The end plate portion 24 side) is formed with a second journal portion 31b.

In the carrier 20, a first journal through hole 27 for inserting the first journal 31a is formed in the base portion 21, and a second journal for inserting the second journal 31b is formed on the end plate portion 24 Use through holes 28. The through hole 27 for the first journal and the through hole 28 for the second journal extend in the axial direction. A first eccentric body 32a and a second eccentric body 32b are provided in a portion of the shaft main body 31 between the first journal portion 31a and the second journal portion 31b.

A first journal bearing 51 is arranged between the first journal through hole 27 and the first journal 31a. Thus, the first journal portion 31a is rotatably held by the carrier 20 via the first journal bearing 51. In addition, a second journal bearing 52 is arranged between the second journal through hole 28 and the second journal 31b. Thereby, the second journal portion 31b is rotatably held in the carrier 20 via the second journal bearing 52.

In this embodiment, the first journal bearing 51 is configured as a tapered roller bearing. The first journal bearing 51 includes: an inner ring 51A mounted on the first journal 31a; an outer ring 51B mounted on the through hole 27 for the first journal; held between the inner ring 51A and the outer ring 51B The rolling element group 51E is composed of a plurality of rolling elements 51C in a tapered shape and a retainer 51D holding the plurality of rolling elements 51C in a state where the plurality of rolling elements 51C are arranged at predetermined intervals.

Similarly, in this embodiment, the second journal bearing 52 is configured as a tapered roller bearing. The second journal bearing 52 includes: an inner ring 52A mounted on the second journal 31b; an outer ring 52B mounted on the through hole 28 for the second journal; held between the inner ring 52A and the outer ring 52B The rolling element group 52E is composed of a plurality of rolling elements 52C having a tapered shape and a retainer 52D holding the plurality of rolling elements 52C in a state where the plurality of rolling elements 52C are arranged at predetermined intervals.

FIG. 2 shows the second journal bearing 52 enlarged and schematically. As shown in FIG. 2(A) and FIG. 2(B), the second journal bearing 52 of the present embodiment is configured such that the rolling element group 52E can be freely detached from the inner ring 52A. Specifically, in the second journal bearing 52, after the outer ring 52B is detachably detached from the rolling element group 52E, the rolling element group 52E can be detachably detached from the inner ring 52A.

In this embodiment, the radial dimension (radius) of the outer peripheral surface of the inner ring 52A gradually decreases from one end to the other end in the axial direction. A flange portion 52F is formed at the end of the inner ring 52A on the side with a larger radial dimension in the axial direction. On the other hand, no flange is formed at the end on the side opposite to the end on the side where the flange 52F is formed (the end on the side with the smaller radial dimension). As a result, the rolling element group 52E can be separated from the end of the inner ring 52A on the side where the flange is not formed.

When the rolling element group 52E is separated from the inner ring 52A, the state in which the retainer 52D holds the plurality of rolling elements 52C in the rolling element group 52E is maintained. In addition, the rolling element group 52E can be assembled in the inner ring 52A by inserting the rolling element group 52E into the inner ring 52A. In this embodiment, the second journal bearing 52 is generally configured as described above to enable the rolling element group 52E to be freely detached and detached, and the first journal bearing 51 may also have the same structure.

Returning to FIG. 1, a first retaining ring 29 a is provided on the inner peripheral surface of the through hole 27 for the first journal. The first retaining ring 29a restricts the axial direction of the first journal bearing 51 by abutting against the outer ring 51B of the first journal bearing 51 from the axial outer side (the side opposite to the opposite side of the swing gear 40) Movement on the outside. Similarly, a second retaining ring 29b is provided on the inner peripheral surface of the through hole 28 for the second journal. The second retaining ring 29b restricts the axial direction of the second journal bearing 52 by abutting against the outer ring 52B of the second journal bearing 52 from the axial outer side (the side opposite to the opposite side of the swing gear 40) Movement on the outside.

The first eccentric body 32 a and the second eccentric body 32 b in the crankshaft 30 are integrally formed with the shaft body 31. The first eccentric body 32a and the second eccentric body 32b are arranged in a state of being arranged along the axial direction. Among them, the first eccentric body 32a is arranged adjacent to the first journal portion 31a, and the second eccentric body 32b is arranged adjacent to the second journal portion 31b.

Each eccentric body 32a, 32b is formed in a disk shape (or cylindrical shape). The eccentric bodies 32 a and 32 b are eccentric with respect to the shaft main body 31. In detail, in the figure, the reference symbol ac represents the central axis of the shaft body 31, the reference symbol aca represents the central axis of the first eccentric body 32a, and the reference symbol acb represents the central axis of the second eccentric body 32b. As shown in this isometric axis, the first eccentric body The central axis aca of 32a and the central axis acb of the second eccentric body 32b are offset from the central axis ac of the shaft body 31. When viewed along the central axis ac of the shaft body 31, the central axis aca of the first eccentric body 32a and the central axis acb of the second eccentric body 32b are symmetrically arranged with the central axis ac of the shaft body 31 as the center.

The reference numeral 36a in the figure denotes the eccentric side portion of the first eccentric body 32a that is eccentric (protruding) to the outermost in the direction from the central axis ac of the shaft main body 31 to the central axis aca of the first eccentric body 32a. The reference numeral 36b indicates the anti-eccentric side portion of the first eccentric body 32a that is located on the side opposite to the eccentric side portion 36a. Similarly, the reference numeral 38a in the figure denotes the eccentric side of the second eccentric body 32b that is eccentric (protruding) to the outermost in the direction from the central axis ac of the shaft body 31 to the central axis acb of the second eccentric body 32a Part, the reference numeral 38b denotes the anti-eccentric side portion of the second eccentric body 32b located on the side opposite to the eccentric side portion 38a. The eccentric bodies 32 a and 32 b are inserted into the through holes formed in the swing gear 40, thereby holding the swing gear 40. The details are discussed later.

In addition, the second journal portion 31b of the shaft body 31 protrudes from the end plate portion 24 of the carrier 20 toward the outer side in the axial direction through the second journal bearing 52. The above-mentioned spur gear 33 is fixed to the portion protruding from the end plate portion 24 in the second journal portion 31b. That is, the spur gear 33 is provided in a part of the second journal portion 31b on the side opposite to the second eccentric body 32b side. The rotation is transmitted from the input gear (not shown) to the spur gear 33, thereby rotating the crankshaft 30.

In addition, in this embodiment, in the carrier 20, three through holes 27 for the first journal and three through holes 28 for the second journal are formed, and the three crankshafts 30 are rotatably held in the carrier 20. . Therefore, regarding the first journal bearing 51, the second journal bearing 52 and the spur gear 33, there are also three respectively.

Next, the swing gear 40 is composed of a first swing gear 40a and a second swing gear 40b. The swing gears 40 a and 40 b are arranged in the axial direction, and are arranged in a space formed between the base plate portion 21 and the end plate portion 24 of the carrier 20. The first swing gear 40a is arranged on the side of the base plate portion 21, and the second swing gear 40b is arranged on the side of the end plate portion 24.

A first external tooth 42a of the external teeth 42 is formed on the outer periphery of the first swing gear 40a. A second external tooth 42b of the external teeth 42 is formed on the outer periphery of the second swing gear 40b. The number of teeth of the first external teeth 42a and the second external teeth 42b is less than the number of teeth of the internal teeth 12 of the housing 10 (for example, one less). Thus, due to the eccentric rotation of the eccentric bodies 32a and 32b, the swing gears 40a and 40b swing and rotate with respect to the housing 10 while meshing the external teeth 42 with the internal teeth 12.

In this embodiment, the first swing gear 40a is formed with three first eccentric body through holes 44a for inserting the first eccentric body 32a of the crankshaft 30 and a first shaft for inserting the shaft portion 22 of the gear carrier 20 Part with through hole 45a. The second swing gear 40b is formed with three second eccentric body through holes 44b for inserting the second eccentric body 32b of the crankshaft 30, and a second shaft through hole 45b for inserting the shaft 22 of the carrier 20.

A first eccentric body bearing 61 is arranged between the first eccentric body through hole 44a and the first eccentric body 32a. Thereby, the first eccentric body 32a is rotatably held in the first swing gear 40a via the first eccentric body bearing 61. In addition, a second eccentric body bearing 62 is arranged between the second eccentric body through hole 44b and the second eccentric body 32b, and the second eccentric body 32b is rotatably held in the second swing through the second eccentric body bearing 62 Gear 40b.

In this embodiment, the first eccentric body bearing 61 is configured as a cylindrical roller bearing (needle roller bearing). Specifically, in this example, the first eccentric body bearing 61 is composed of a plurality of cylindrical rolling elements 61A and a cage 61B that holds the plurality of rolling elements 61A. Therefore, in a state where the first eccentric body bearing 61 is arranged between the first eccentric body through hole 44a and the first eccentric body 32a, each rolling element 61A approaches or abuts against the first eccentric body through hole 44a. It is close to or abuts against the first eccentric body 32a.

Similarly, in this embodiment, the second eccentric body bearing 62 is configured as a cylindrical roller bearing (needle roller bearing). Furthermore, in this example, the bearing 62 for the second eccentric body is also composed of a plurality of cylindrical rolling elements 62A and a retainer 62B holding the plurality of rolling elements 62A. Therefore, in a state where the second eccentric body bearing 62 is arranged between the second eccentric body through hole 44b and the second eccentric body 32b, each rolling element 62A approaches or abuts against the second eccentric body through hole 44b. The second eccentric body 32b is close to or abuts against it.

Here, in FIG. 1, the reference sign Rc represents the distance from the central axis (ac) of the crankshaft 30 to the anti-eccentric side portion 38b of the second eccentric body 32b and the bearing for the second eccentric body inserted into the eccentric body 32b Add the thickness dimensions of 62 to get the added distance. In addition, the reference sign Rj denotes the outermost peripheral radius (the maximum oscillating radius of gyration) of the rolling element 52C of the second journal bearing 52 inserted into the second journal 31b of the crankshaft 30. In this embodiment, the rolling element 52C is formed in a tapered shape such that its central axis is inclined with respect to the central axis of the second journal bearing 52. In addition, the outer peripheral edge of the end of the rolling element 52C that becomes one of the large diameters extends outward in the radial direction with respect to the central axis of the second journal bearing 52. The outermost radius Rj refers to the distance from the central axis of the second journal bearing 52 to the outer peripheral edge of the end of the rolling element 52C that becomes one of the major diameters.

As can be seen from FIG. 1, in this embodiment, the outermost radius Rj of the rolling element 52C of the second journal bearing 52 is greater than the addition distance Rc. In addition, the reference sign Rir in the figure denotes the outermost peripheral radius of the inner ring 52A of the second journal bearing 52. The outermost radius Rir of the inner ring 52A is smaller than the addition distance Rc. In addition, in this embodiment, the outermost radius of the rolling element 51C of the first journal bearing 51 is also greater than the distance from the central axis of the crankshaft 30 to the anti-eccentric side portion 36b of the first eccentric body 32a and the distance inserted into the eccentric body The thickness dimension of the bearing 61 for the first eccentric body of 32a is added to obtain a large added distance.

In the gear device 1 having the above structure, when torque from a motor, not shown, is transmitted to the spur gear 33, the crankshaft 30 rotates. At this time, the first eccentric body 32a and the second eccentric body 32b of the crankshaft 30 respectively perform eccentric rotation. When the eccentric bodies 32a, 32b rotate eccentrically, the respective swing gears 40a, 40b revolve (revolve) around the center axis of the carrier 20 as a center. At this time, the swing gears 40 a and 40 b rotate with respect to the housing 10 while having their outer teeth 42 meshing with the inner teeth 12 of the housing 10. As a result, the carrier 20 supporting the swing gears 40 a and 40 b via the crankshaft 30 rotates with respect to the housing 10.

This type of gear device 1 can be used as a reducer for the rotating body, arm joints, etc. of a robot Revolving parts, revolving parts of various machine tools, etc. As a specific example, by fixing the housing 10 to the base of the robot and connecting the gear frame 20 with the revolving body of the robot, the revolving body can be rotated with respect to the base with high torque and controlled with high precision. The rotation.

(Manufacturing method of eccentric swing gear device)

Next, a method of manufacturing the aforementioned gear device 1 will be described with reference to FIGS. 3 and 4.

In the manufacturing method of the gear device 1 of this embodiment, first, assembling is performed as shown in FIG. 3 until the crankshaft 30 is erected on the base 23 placed on the working surface. At this time, first, the base 23 is placed on the work surface so that the base plate 21 of the base 23 of the carrier 20 abuts on the work surface. The first retaining ring 29 a is provided on the inner peripheral surface of the first journal through hole 27 of the base plate portion 21.

Next, the first eccentric body bearing 61 is inserted and installed in the first eccentric body 32a of the crankshaft 30 separated from the base 23, and the second eccentric body bearing 62 is inserted and installed in the second eccentric body 32b. In addition, the first eccentric body bearing 61 is inserted into the first eccentric body through hole 45 a of the first swing gear 40 a, and the first swing gear 40 a is held by the crankshaft 30.

Next, the first journal bearing 51 is inserted and installed in the first journal 31 a of the crankshaft 30. The first journal bearing 51 is mounted on the first journal 31a in a state where the inner ring 51A, the outer ring 51B, and the rolling element group 51E are integrated. In addition, only the inner ring 52A of the second journal bearing 52 is inserted and mounted to the second journal 31b of the crankshaft 30.

Next, the first journal bearing 51 held by the crankshaft 30 is inserted into the first journal through hole 27 of the base plate portion 21, and the outer ring 51B is press-fitted to abut the first retaining ring 29a. Thus, it is placed in the state shown in FIG. 3.

Next, as shown in FIGS. 3 and 4, the second swing gear 40b is made to pass through the second eccentric body through hole 44b formed in the second swing gear 40b by the inner ring 52A of the second journal bearing 52 Moving from the second journal portion 31b side to the second eccentric body 32b side, the second eccentric body bearing mounted to the second eccentric body 32b is inserted into the second eccentric body through hole 44b 62.

Then, as shown in FIG. 4, the rolling element group 52E is assembled to the inner ring 52A of the second journal bearing 52, and the outer ring 52B is assembled to the rolling element group 52E. In the example shown in the figure, the outer ring 52B of the second journal bearing 52 is inserted into the through hole 28 for the second journal of the end plate portion 24. Therefore, the outer ring 52B is assembled in the rolling element group 52E while being held by the end plate portion 24. After that, by fastening the end plate portion 24 and the shaft portion 22 of the base portion 23 with the bolt 25, the assembly operation is completed. Thus, the gear device 1 is manufactured.

(effect)

According to the gear device 1 of this embodiment described above, the outermost radius Rj of the rolling element 52C of the second journal bearing 52 is greater than the distance from the central axis of the crankshaft 30 to the anti-eccentric portion 38b of the second eccentric body 32b and The thickness dimension of the bearing 62 for the second eccentric body inserted into the eccentric body 32b is added, and the added distance Rc is large. According to this structure, the radial dimension of the second journal bearing 52 is increased. In addition, the first journal bearing 51 is also the same. Thereby, the load capacity of the journal bearings 51, 52 arranged between the journal bearings 51, 52 of the crankshaft 30 and the carrier 20 can be increased.

In addition, a spur gear 33 as a transmission gear is provided at a portion of the second journal portion 31b of the crankshaft 30 inserted into the second journal bearing 52 on the side opposite to the side of the second eccentric body 32b. As a result, the spur gear 33 is supported by the second journal bearing 52 whose load capacity has been increased. Therefore, the support rigidity of the spur gear 33 can be largely ensured.

In addition, the journal bearings 51 and 52 are tapered roller bearings, and therefore, they support the crankshaft 30 from the axial direction. Thereby, the movement of the crankshaft 30 in the axial direction can be restricted.

In addition, the second journal bearing 52 includes: an inner ring 52A installed on the second journal 31b; an outer ring 52B installed in the second journal through hole 28 of the gear carrier 20; including an inner ring 52A and The rolling element group 52E of the plurality of rolling elements 52C between the outer ring 52B, and the second journal bearing 52 are configured so that the rolling element group 52E can be detachably separated from the inner ring 52A. According to this, the assemblability of the gear device 1 can be improved by increasing the variation of assembly.

In addition, in the manufacturing method of this embodiment, as described above, the following steps are performed: the step of mounting the second eccentric body bearing 62 on the second eccentric body 32b of the crankshaft 30; and the inner ring 52A of the second journal bearing 52 The process of installing on the second journal portion 31b of the crankshaft 30; the second swing gear 40b passes through the second eccentric body through hole 44b formed in the second swing gear 40b from the second journal portion The step of moving the side 31b to the side of the second eccentric body 32b and inserting the bearing 62 for the second eccentric body into the through hole 44b for the second eccentric body; the step of assembling the rolling element group 52E and the outer ring 52B to the inner ring 52A.

According to this manufacturing method, the outermost radius Rj of the rolling element 52C of the second journal bearing 52 is greater than the portion from the central axis of the crankshaft 30 to the anti-eccentric side portion of the second eccentric body 32b, even if it is the gear device 1 of this embodiment. When the distance of 38b and the thickness of the second eccentric body bearing 62 inserted into the eccentric body 32b are added together to obtain a large summed distance Rc, the gear device 1 can be manufactured efficiently.

That is, in the case of the structure in which the outermost radius Rj of the rolling element 52C of the second journal bearing 52 is greater than the added distance Rc, the following assembly sequence is also conceived: on the crankshaft 30, the second swing gear 40b is mounted to the second After the bearing 62 for the eccentric body, the second journal bearing 52 is mounted on the second journal 31b of the crankshaft 30, and then the second journal bearing 52 is inserted into the second journal through hole 28 of the end plate portion 24. However, this assembly sequence takes labor and time. With respect to this assembly sequence, in the manufacturing method of this embodiment, the following steps are performed: the second swing gear 40b is made to pass through the second eccentric body through hole 44b formed in the second swing gear 40b by the inner ring 52A The second journal portion 31b side moves toward the second eccentric body 32b side, and the second eccentric body bearing 62 is inserted into the second eccentric body through hole 44b. As a result, the assembly sequence can be simplified, and therefore, the gear device 1 can be manufactured efficiently. Therefore, the gear device 1 capable of increasing the load capacity of the journal bearings 51 and 52 can be efficiently manufactured.

In addition, in this embodiment, the outermost peripheral radius Rir of the inner ring 52A of the second journal bearing 52 is smaller than the addition distance Rc. According to this, the second swing gear can be reliably made so that the inner ring 52A passes through the second eccentric body through hole 44b formed in the second swing gear 40b. The process of 40b moving from the second journal portion 31b side to the second eccentric body 32b side. Therefore, the assembly work can be performed smoothly.

Above, an embodiment of the present invention has been described, but the present invention is not limited to the above-mentioned embodiment. For example, in the above-mentioned embodiment, an example in which the gear device 1 is provided with three crankshafts 30 has been described, but the number of crankshafts 30 is not particularly limited.

In addition, for example, in the above-mentioned embodiment, in the second journal bearing 52, a flange portion 52F is formed at the end of the inner ring 52A on the side with a larger radial dimension in the axial direction. The end on the side opposite to the end on the side where the flange 52F is formed (the end on the side with the smaller radial dimension) is not formed with a flange. As a result, the rolling element group 52E can be separated from the end of the inner ring 52A on the side where the flange is not formed. However, it is also possible that flanges are formed on both ends of the inner ring 52A in the axial direction to deform the flanges at the end of the inner ring 52A on the side with the smaller radial dimension, thereby rolling The body group 52E can be separated from the inner ring 52A.

1: Eccentric swing type gear device

10: Shell

11: Shell body

12: Internal teeth

13: pin groove

20: Gear frame

21: Board Department

22: Shaft

23: base

24: End plate

25: Bolt

26: main bearing

27: Through hole for the first journal

28: Through hole for the second journal

29a: first retaining ring

29b: second retaining ring

30: crankshaft

31: Shaft body

31a: first journal

31b: second journal

32a: The first eccentric body

32b: second eccentric body

33: Spur gear

36a: eccentric side part

36b: Anti-eccentric side part

38a: eccentric side part

38b: Anti-eccentric side part

40: swing gear

40a: The first swing gear

40b: Second swing gear

42: External tooth

42a: First external tooth

42b: second external tooth

44a: Through hole for the first eccentric body

44b: Through hole for the second eccentric body

45a: Through hole for the first shaft

45b: Through hole for the second shaft

51: The first journal bearing

51A: inner circle

51B: Outer ring

51C: rolling element

51D: Retainer

51E: rolling element group

52: The second journal bearing

52A: inner circle

52B: Outer ring

52C: rolling element

52D: Retainer

52E: Rolling element group

61: Bearing for the first eccentric body

61A: rolling element

61B: retainer

62: Bearing for the second eccentric body

62A: rolling element

62B: Retainer

ac: central axis

aca: reference number/central axis

acb: reference number/central axis

L1: Central axis

Rc: Adding distance

Rj: The outermost radius of the rolling element

Rir: the outermost radius of the inner ring

Claims (4)

An eccentric oscillating gear device comprising: a housing with internal teeth on the inner circumference side; a gear holder rotatably held in the housing; a crankshaft rotatably held in the gear holder; and a swing gear that holds The crankshaft has external teeth meshing with the internal teeth and is oscillated by the crankshaft. The crankshaft has a journal portion and an eccentric body disposed adjacent to the journal portion, and the gear frame is formed with an insert for inserting In the through hole of the journal, a journal bearing is arranged between the through hole of the carrier and the journal, and the journal is rotatably held in the carrier via the journal bearing and swings The gear is formed with a through hole for inserting the eccentric body, a bearing for the eccentric body is arranged between the through hole of the swing gear and the eccentric body, and the eccentric body is rotatably held by the swing gear via the bearing for the eccentric body , The journal bearing has: an inner ring mounted on the journal; an outer ring mounted on the through hole of the gear carrier; and a rolling element including a plurality of rolling elements held between the inner ring and the outer ring The journal bearing is configured to enable the rolling elements to be assembled and disassembled freely and separated from the inner ring. The outermost peripheral radius ratio of the rolling elements of the journal bearing will be from the central axis of the crankshaft to the eccentric body. The distance between the eccentric side portion and the thickness dimension of the bearing for the eccentric body inserted into the eccentric body are added to obtain a large summed distance, and the outermost peripheral radius of the inner ring of the journal bearing is smaller than the summed distance. The eccentric oscillating gear device of claim 1, wherein a transmission gear is provided on a part of the journal portion on the side opposite to the side of the eccentric body. Such as the eccentric swing type gear device of claim 1 or 2, wherein the above-mentioned journal bearing is a tapered roller bearing. An eccentric oscillating gear device manufacturing method, the eccentric oscillating gear device comprising: a housing with internal teeth on the inner peripheral side; a gear carrier held in the housing freely rotatably; and a gear holder rotatably held in the gear carrier A crankshaft; and a swing gear, which is held on the crankshaft, has external teeth that mesh with the internal teeth, and is oscillated by the crankshaft. The manufacturing method of the eccentric swing gear device includes the steps of: mounting the eccentric body bearing on The process of the eccentric body of the crankshaft; the process of installing the inner ring of the journal bearing on the journal of the crankshaft; the swing gear is moved from the journal in such a way that the inner ring passes through the through hole formed in the swing gear The process of moving the part side to the side of the eccentric body to insert the bearing for the eccentric body mounted on the eccentric body into the through hole; and the process of assembling the rolling element group and the outer ring to the inner ring; and the journal The outermost radius of the inner ring of the bearing is smaller than the sum of the distance from the central axis of the crankshaft to the anti-eccentric side portion of the eccentric body and the thickness dimension of the bearing for the eccentric body inserted into the eccentric body. .

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