CN117628125A

CN117628125A - Gear transmission device

Info

Publication number: CN117628125A
Application number: CN202311511979.4A
Authority: CN
Inventors: 高桥昌宏
Original assignee: Nabtesco Corp
Current assignee: Nabtesco Corp
Priority date: 2015-04-14
Filing date: 2016-04-07
Publication date: 2024-03-01
Also published as: KR102580787B1; JP6659232B2; CN106051060A; DE102016205517A1; TWI695939B; KR20160122639A; TW201641838A; JP2016200263A

Abstract

The invention provides a gear transmission device, wherein the meshing precision of a pair of gears which are meshed in an orthogonal state for changing the rotation direction can be improved, so that the assembly cost can be reduced. The gear transmission device (1) has a rotation direction changing mechanism (20), a reduction mechanism (80), and a main housing (10) to which the rotation direction changing mechanism (20) and the reduction mechanism (80) are attached. The rotation direction conversion mechanism (20) has a 1 st gear (32) and a 2 nd gear (42) which is disposed in an orthogonal posture to the 1 st gear (32) and meshes with the 1 st gear (32). The speed reduction mechanism (80) has an output shaft from which rotation transmitted from the 1 st gear (32) to the 2 nd gear (42) is output. The 1 st gear (32) and the 2 nd gear (42) are rotatably supported by the main housing (10).

Description

Gear transmission device

The present application is a divisional application of the application having the application date 2016, 4 and 7, the application number 201610213401.4 and the name of "gear transmission".

Technical Field

The present invention relates to a gear transmission.

Background

A reduction mechanism is known, which includes: a carrier for holding the crankshaft so as to be rotatable; an external gear engaged with the crankshaft; an internal gear having a different number of teeth from the external gear, and the external gear is caused to oscillate in the internal gear. In such a reduction mechanism, an eccentric body is provided on the crankshaft, and the eccentric body is engaged with the external gear. When the crankshaft rotates, the eccentric body eccentrically rotates, and the external gear engaged with the eccentric body swings.

In such a reduction mechanism, the internal gear rotates while restraining the external gear from rotating by restraining the carrier from rotating. In such a configuration, the internal gear is used as the output shaft, and the rotation of the crankshaft can be decelerated and output. In addition, when the rotation of the carrier is not restricted but the rotation of the internal gear is restricted, the external gear revolves while rotating. In this case, the carrier coupled to the external gear via the crankshaft also rotates. In such a configuration, the carrier is used as the output shaft, and the rotation of the crankshaft can be decelerated and output.

In such a reduction mechanism, the rotation of the rotary shaft of the motor is transmitted to the crankshaft and then to the output shaft (internal gear or carrier).

In industrial robots and machine tools, it is sometimes desirable to have a structure in which the rotation shaft of a motor and the output shaft of a reduction mechanism are in an orthogonal relationship. In this case, a relay shaft disposed in a posture orthogonal to the input shaft of the torque input to the motor may be generally used. Specifically, the rotation direction of the input shaft may be changed by meshing a gear provided on the input shaft with a gear provided on the relay shaft. A gear transmission device in which such a rotation direction conversion mechanism and a reduction mechanism are combined is incorporated in a robot or the like. By meshing a pair of bevel gears or a pair of hypoid gears, torque can be transmitted from an input shaft disposed orthogonal to the relay shaft. For example, patent document 1 discloses such a gear transmission.

Prior art literature

Patent literature

Patent document 1: international publication No. 2007/125835

Disclosure of Invention

Problems to be solved by the invention

In the gear transmission disclosed in patent document 1, a housing for holding an input shaft, a housing for holding a relay shaft, and a reduction mechanism are mounted on a base that is placed on the ground or the like. The housing for holding the input shaft holds the input shaft inside the housing via a bearing.

The housing is fastened to the base in a state of being inserted into a hole formed in the base.

However, in this structure, the hole formed in the base is in contact with the outer peripheral surface of the housing, the inner peripheral surface of the housing is in contact with the outer ring of the bearing, and the inner ring of the bearing is in contact with the outer peripheral surface of the input shaft. As a result, the tolerance stack of many elements tends to reduce the accuracy of the engagement between the gear of the input shaft and the gear of the relay shaft. Therefore, the adjustment work for obtaining the desired accuracy may take a lot of labor and time, and the assembly cost may increase.

The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a gear transmission device capable of improving meshing accuracy of a pair of gears meshing in an orthogonal state for changing a rotation direction, thereby reducing assembly costs.

Solution for solving the problem

The gear transmission device of the present invention includes a rotation direction conversion mechanism including a 1 st gear and a 2 nd gear disposed in a posture orthogonal to the 1 st gear and engaged with the 1 st gear, a speed reduction mechanism including an output shaft from which rotation transmitted from the 1 st gear to the 2 nd gear is output, and a main housing to which the rotation direction conversion mechanism and the speed reduction mechanism are attached, wherein the 1 st gear and the 2 nd gear are rotatably supported by the main housing.

In the gear transmission device, the 1 st gear may be provided on an input shaft and rotate integrally with the input shaft, the 2 nd gear may be provided on a relay shaft and rotate integrally with the relay shaft, the relay shaft may be disposed in a posture orthogonal to the input shaft, the main housing may have an input shaft bearing hole into which the input shaft is inserted and a relay shaft bearing hole into which the relay shaft is inserted, the 1 st gear may be rotatably supported by the main housing via the input shaft and rotatably supported by the relay shaft bearing hole, and the 2 nd gear may be rotatably supported by the main housing.

More specifically, the input shaft may be rotatably supported by a bearing provided in the input shaft bearing hole, and the relay shaft may be rotatably supported by a bearing provided in the relay shaft bearing hole.

According to the gear transmission device of the present invention, the 1 st gear and the 2 nd gear in the rotation direction changing mechanism are rotatably supported in the common main housing, and elements interposed between the main housing and the 1 st and 2 nd gears are suppressed, so that tolerance accumulation is suppressed. As a result, the meshing accuracy of the pair of gears meshing in an orthogonal state for changing the rotation direction can be improved, and the assembly cost can be reduced.

In the gear transmission device, at least one of the bearing provided in the input shaft bearing hole and the bearing provided in the intermediate shaft bearing hole may be provided so as to partially protrude from the corresponding bearing hole.

According to this configuration, the part of the bearing protruding from the bearing hole can be used for positioning the member, and the assembling workability can be improved.

Specifically, the bearing provided in the input shaft bearing hole may be provided so as to partially protrude from the input shaft bearing hole. The 1 st gear may be located on the inner side of the main housing than a bearing provided in the input shaft bearing hole, the input shaft may extend from the bearing provided in the input shaft bearing hole to the outside of the main housing, a sub-housing covering the input shaft may be provided on the radially outer side of a portion of the input shaft extending from the bearing to the outside of the main housing, and the sub-housing may be locked to a portion of the bearing protruding from the bearing.

In this case, since the bearing can be used for positioning the sub-housing, workability in assembly can be improved.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, the meshing accuracy of the pair of gears meshing in an orthogonal state for changing the rotation direction can be improved, and the assembly cost can be reduced.

Drawings

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

Fig. 2 is a cross-sectional view of the main housing of the gear assembly of fig. 1.

Description of the reference numerals

1. A gear transmission; 10. a main housing; 11A, bearing holes for input shafts; 12C, a bearing hole for the relay shaft; 20. a rotation direction changing mechanism; 30. an input shaft unit; 31. an input shaft; 32. 1 st gear; 33. a 1 st main bearing; 35. a sub-housing; 40. a relay shaft unit; 41. a relay shaft; 42. a 2 nd gear; 43. a 3 rd gear; 80. a speed reducing mechanism.

Detailed Description

An embodiment of the present invention will be described below with reference to the drawings.

Fig. 1 shows a cross-sectional view of a gear assembly 1 according to an embodiment of the invention. As shown in fig. 1, the gear transmission 1 includes: a rotation direction changing mechanism 20; a speed reducing mechanism 80; an intermediate gear mechanism 60 interposed between these rotation direction changing mechanisms 20 and the reduction mechanism 80; and a main housing 10 to which the respective mechanisms 20, 60, 80 are mounted.

The rotation direction changing mechanism 20 includes an input shaft unit 30 and a relay shaft unit 40. In the gear transmission 1, the rotation output from the input shaft unit 30 is transmitted to the relay shaft unit 40. At this time, the rotation direction of the input shaft unit 30 is changed by the relay shaft unit 40. The rotation whose direction is changed by the relay shaft unit 40 is transmitted to the intermediate gear mechanism 60, and then transmitted to the reduction mechanism 80.

Fig. 2 shows the main housing 10. As shown in fig. 2, the main housing 10 has a 1 st hole 11 for accommodating the input shaft unit 30, a 2 nd hole 12 for accommodating the intermediate shaft unit 40, a 3 rd hole 13 for accommodating the intermediate gear mechanism 60, and a 4 th hole 14 for guiding wiring and the like to the outside of the gear transmission 1.

In fig. 2, reference numeral L1 denotes a 1 st axis. The 1 st axis L1 is located on the rotation center of the rotation output from the reduction mechanism 80. Reference numeral L2 denotes a 2 nd axis orthogonal to the 1 st axis L1. The main casing 10 is formed with a 1 st flat surface 16 on which the reduction mechanism 80 is placed and which positions the reduction mechanism 80, and a 2 nd flat surface 17 which abuts against the installation surface when the gear transmission 1 is installed on the installation surface. The 1 st flat surface 16 and the 2 nd flat surface 17 extend along the 2 nd axis L2.

The 1 st hole 11 of the holes 11 to 14 extends from the outer side toward the inner side of the main casing 10 along the 2 nd axis L2. The 1 st hole 11 has an input shaft bearing hole 11A located on the outer side of the main casing 10 and a 1 st gear housing hole 11B located on the inner side of the main casing 10 and having a diameter smaller than that of the input shaft bearing hole 11A. A stepped surface 11C is formed between the input shaft bearing hole 11A and the 1 st gear housing hole 11B.

The 2 nd hole 12 extends along the 1 st axis L1 from the 2 nd flat surface 17 toward the 1 st flat surface 16 side. The 2 nd hole 12 is formed at a position offset from the 1 st axis L1 toward the 1 st hole 11 side along the 2 nd axis L2 direction. The 2 nd hole 12 and the 1 st hole 11 intersect at a part, and communicate with each other at a part. The 2 nd hole 12 includes an inlet hole 12A that opens to the 2 nd flat surface 17, a 2 nd gear accommodating hole 12B that is formed on the 1 st flat surface 16 side of the inlet hole 12 and communicates with the 1 st hole 11 (1 st gear accommodating hole 11B), and a relay shaft bearing hole 12C that is formed on the 1 st flat surface 16 side of the 2 nd gear accommodating hole 12B. The relay shaft bearing hole 12C is formed so as to face the outer peripheral portion of the 1 st flat surface 16 through the wall portion of the main casing 10 without penetrating the 1 st flat surface 16.

The 3 rd hole 13 is formed in a ring shape centering on the 1 st axis L1. The 3 rd hole 13 and the 2 nd hole 12 are partially intersected and partially communicated with each other. In addition, the 3 rd hole 13 is opened to the 1 st flat surface 16. The 4 th hole 14 is a hole formed coaxially with the 1 st axis L1, and is formed on the inner peripheral side of the 3 rd hole 13. Here, a cylindrical peripheral wall 18 for dividing the 3 rd hole 13 and the 4 th hole 14 is formed in the main casing 10. The peripheral wall 18 extends from the 2 nd flat surface 17 toward the 1 st flat surface 16. An inner peripheral portion of the 3 rd hole 13 is defined by an outer peripheral surface of the 2 nd peripheral wall portion 18, and an outer peripheral portion of the 4 th hole 14 is defined by an inner peripheral surface of the peripheral wall portion 18. The 4 th hole 14 opens at the 1 st flat surface 16 side end of the peripheral wall portion 18 and opens at the 2 nd flat surface 17.

As shown in fig. 1, the input shaft unit 30 has: an input shaft 31; a 1 st gear 32 provided at one end of the input shaft 31 and rotating integrally with the input shaft 31; a 1 st main bearing 33 provided on one end side of the input shaft 31 at a position closer to the other end side than the 1 st gear 32; a 1 st sub bearing 34 provided on the other end side of the input shaft 31; and a sub-housing 35 inserted (sleeved) on the outer peripheral surfaces of the 1 st main bearing 33 and the 1 st sub-bearing 34. The 1 st main bearing 33 and the 1 st sub bearing 34 are each configured as a thrust angular ball bearing in the present embodiment.

In the input shaft unit 30, the input shaft 31 is inserted into the 1 st hole 11 from the 1 st gear 32 side in a state where the 1 st main bearing 33 is provided. The 1 st gear 32 is disposed inside the 1 st gear housing hole 11B in the 1 st hole 11, and the 1 st main bearing 33 is inserted (fitted) into the input shaft bearing hole 11A in the 1 st hole 11 and positioned by abutting against the stepped surface 11C. Thus, the input shaft 31 is rotatably supported by the input shaft bearing hole 11A (main housing 10) from the radially outer side thereof via the 1 st main bearing 33. As a result, the 1 st gear 31 is rotatably supported by the main casing 10. The input shaft 31 is formed with a drive shaft insertion hole 31A extending from the other end portion to one end portion side on the outer side of the main casing 10. A drive shaft of a motor, not shown, is inserted into the drive shaft insertion hole 31A. Thereby, the input shaft 31 rotates by the rotation of the motor.

The input shaft 31 extends from the 1 st main bearing 33 toward the outside of the main housing 10. The sub-housing 35 is provided radially outward of a portion of the input shaft 31 extending outward from the 1 st main bearing 33, and is formed in a cylindrical shape to cover the input shaft 31 from the radially outward side. As shown in fig. 1, the 1 st main bearing 33 of the present embodiment is provided so that part thereof protrudes outward along the axial direction from the input shaft bearing hole 11A. An opening at one end of the sub-housing 35 is engaged with or inserted into the outer peripheral surface of the protruding portion of the 1 st main bearing 33. Thereby, the sub-housing 35 is positioned by the 1 st main bearing 33.

The sub-housing 35 has an outer peripheral surface of the 1 st sub-bearing 34 provided on the other end side of the input shaft 31 inserted therein. Thus, the other end portion of the input shaft 31 is rotatably supported by the sub-housing 35 from the radially outer side thereof via the 1 st sub-bearing 34.

The sub-housing 35 is fastened to the main housing 10 by a bolt, not shown, with an opening at one end thereof engaged with the 1 st main bearing 33. Thereby, the input shaft unit 30 is fixed to the main casing 10.

The relay shaft unit 40 has: a relay shaft 41; a 2 nd gear 42 and a 3 rd gear 43 provided between the one end portion 41a and the other end portion 41b of the relay shaft 41 and rotating integrally with the relay shaft 41; a 2 nd sub bearing 44 provided at one end 41a of the relay shaft 41; a 2 nd main bearing 45 provided at the other end 41b of the relay shaft 41; and a fixing plate 46 coupled to the relay shaft 41 via a 2 nd main bearing 45 and fixing the relay shaft unit 40 to the main casing 10.

The relay shaft 41 is disposed in a posture orthogonal to the input shaft 31, and similarly, the 2 nd gear 42 is disposed in a posture orthogonal to the 1 st gear 31 and is engaged with the 1 st gear 32. The 2 nd gear 42 is provided on the one end 41a side of the relay shaft 41, and the 3 rd gear 43 is provided on the other end 41b side of the relay shaft 41. The 2 nd sub-bearing 44 and the 2 nd main bearing 45 are each configured as a thrust angular ball bearing in the present embodiment.

The relay shaft unit 40 is inserted into the 2 nd hole 12 from the one end 41a side of the relay shaft 41 in a state where the above-described respective members are integrated. The 2 nd sub-bearing 44 provided at the one end 41a of the relay shaft 41 is inserted (fitted) into the relay shaft bearing hole 12C in the 2 nd hole 12, and is positioned by abutting against the bottom surface of the relay shaft bearing hole 12C. In this state, the 2 nd gear 42 and the 3 rd gear 43 are disposed in the 2 nd gear housing hole 12B in the 2 nd hole 12, and the 2 nd gear 42 is engaged with the 1 st gear 32. The fixing plate 46 is fastened to the main casing 10 with a bolt, not shown, in a state where the outer peripheral portion thereof abuts against the outer peripheral portion of the inlet hole 12A of the 2 nd hole 12. Thereby, the relay shaft unit 40 is fixed to the main casing 10.

In the present embodiment, the 2 nd sub-bearing 44 is provided so that part thereof protrudes from the relay shaft bearing hole 12C to the outside of the hole 12C along the axial direction thereof. Similarly, the 2 nd main bearing 45 is provided so that part thereof protrudes from a bearing hole formed in the fixing plate 46 to the outside of the hole along the axial direction thereof. The 2 nd sub-bearing 44 and the 2 nd main bearing 45 may not protrude from the corresponding bearing holes.

In a state where the relay shaft unit 40 is fixed to the main casing 10, as described above, the one end 41a of the relay shaft 41 is inserted into the relay shaft bearing hole 12C via the 2 nd sub bearing 44. Thus, the one end 41a of the relay shaft 41 is rotatably supported by the relay shaft bearing hole 12C (main casing 10) from the radially outer side thereof via the 2 nd sub bearing 44. As a result, the 2 nd gear 42 is rotatably supported by the main casing 10.

On the other hand, the other end 41b of the intermediate shaft 41 is rotatably supported by the fixed plate 46 from the radially outer side thereof via the 2 nd main bearing 45. In the present embodiment, the relay shaft 41 is supported in the axial direction by fastening the fixing plate 46 to the main casing 10, so that the axial load of the relay shaft 41 is supported, and the relay shaft unit 40 is prevented from coming off from the 2 nd hole 12.

As described above, the rotation direction changing mechanism 20 is completed by fixing the input shaft unit 30 and the relay shaft unit 40 to the common main casing 10. In the rotation direction changing mechanism 20, the 1 st gear 32 of the input shaft 31 of the input shaft unit 30 and the 2 nd gear 42 of the relay shaft 41 of the relay shaft unit 40 are engaged. The input shaft 31 and the relay shaft 41 are orthogonal. Thereby, the rotational direction of the input shaft 31 is changed. As the 1 st gear 32 and the 2 nd gear 42, bevel gears or hypoid gears may be used. In the present embodiment, the 3 rd gear 43 is a spur gear.

The intermediate gear mechanism 60 has: a 4 th gear 62 rotatably supported by a center bearing 61 formed of a thrust angular ball bearing provided on the outer peripheral surface of the peripheral wall portion 18; an annular flange 63 having an outer peripheral edge portion fixed to an inner peripheral edge portion of the 4 th gear 62 on the 1 st flat surface 16 side by bolts; a cylindrical shaft portion 64 extending from the inner peripheral edge portion of the flange portion 63 toward the 1 st flat surface 16 side along the 1 st axis L1; a 5 th gear 65 provided on the outer peripheral portion of the distal end portion of the shaft portion 64; and a bearing engaging portion 66 extending further along the 1 st axis L1 from the tip end portion of the shaft portion 64.

The 4 th gear 62 is a spur gear, is accommodated in the 3 rd hole 13, and meshes with the 3 rd gear 43 of the relay shaft unit 40. The flange 63 extends from a fixed position with the 4 th gear 62 toward the peripheral wall 18, and an inner peripheral edge thereof is located opposite to an axial end of the peripheral wall 18. The shaft portion 64 extends along the 1 st axis L1 from the inner peripheral edge portion of the flange portion 63, and is exposed to the outside from the 1 st flat surface 16. In the present embodiment, the flange 63, the shaft 64, the 5 th gear 65, and the bearing engaging portion 66 are integrally formed.

In the intermediate gear mechanism 60, the 4 th gear 62 rotates about the 1 st axis L1 due to the rotation of the 3 rd gear 43 of the relay shaft unit 40. Thereby, the intermediate gear mechanism 60 rotates as a whole. The 5 th gear 65 transmits the rotation to the reduction mechanism 80. In the present embodiment, the 5 th gear 65 is constituted as a spur gear.

The speed reducing mechanism 80 includes: a crankshaft 81 having eccentric bodies 81a, 81b formed thereon; external gears 82a,82b engaged with the eccentric bodies 81a, 81b and revolving around the crankshaft 81 with rotation of the crankshaft 81; an inner gear 90 surrounding the outer gears 82a,82b and having inner pins meshing with the outer teeth. The number of teeth of the inner tooth pin is different from the number of teeth of the outer tooth.

A 6 th gear 83 that rotates integrally with the crankshaft 81 is fixed to the crankshaft 81. The 6 th gear 83 is meshed with the 5 th gear 65 of the intermediate gear mechanism 60. The crankshaft 81 is supported by a pair of tapered roller bearings 84a, 84b so as to be rotatable relative to the carriers 85a, 85b but not axially displaceable. When the crankshaft 81 rotates, the eccentric bodies 81a and 81b eccentrically rotate. When the eccentric bodies 81a and 81b eccentrically rotate, the external gears 82a and 82b revolve around the crankshaft 81.

The carriers 85a and 85b are disposed so as to sandwich the external gears 82a and 82b, and are fixed to each other by bolts 86. In the present embodiment, the gear frames 85a, 85b are supported by a pair of thrust angular ball bearings 86a, 86b so that the internal gear 90 can rotate and cannot be displaced in the axial direction. A thrust angular ball bearing 100 is provided between the carrier 85a and the bearing engagement portion 66 of the intermediate gear mechanism 60, and the entire intermediate gear mechanism 60 is supported by the thrust angular ball bearing 100 so as to be rotatable relative to the carrier 85 a.

The carrier 85a has a columnar portion 87 for coupling with the carrier 85 b. The bolt 86 is inserted into the columnar portion 87. The columnar portion 87 passes through the through holes formed in the external gears 82a,82 b. The carriers 85a and 85b are coupled to the external gears 82a and 82b via the crankshaft 81 so as not to rotate relative to the external gears 82a and 82b. The crankshaft 81 and the columnar portion 87 are formed in plurality in the circumferential direction with respect to the centers of the thrust angular ball bearings 86a and 86b, and the external gears 82a and 82b are formed with a plurality of through holes through which the crankshaft 81 and the columnar portion 87 pass, but this is not shown.

In the reduction mechanism 80, the number of teeth of the external gears 82a,82b is smaller than the number of teeth of the internal teeth pin (for example, 1 less). Thus, each time the crankshaft 81 rotates, the external teeth and the internal tooth pins are engaged with each other, and the external gears 82a and 82b are eccentrically rotated to oscillate relatively to the internal gear 90. Here, in the present embodiment, the gear frame 85a is fixed to the main casing 10 by bolts 88. Thus, the rotation of the external gears 82a,82b is restrained. Thus, when the crankshaft 81 rotates, the external gears 82a,82b revolve without rotating. In this revolution, the external gears 82a,82b rotate the internal gear 90 with respect to the carriers 85a, 85 b. Thereby, the internal gear 90 rotates.

The plate 92 is fixed to the internal gear 90 by bolts 91. The reduction mechanism 80 outputs rotation using the plate 90 as an output shaft. A cylinder 93 is provided in the center of the plate 92. After passing through the reduction mechanism 80, the tube 93 passes through the shaft portion 64 of the intermediate gear mechanism 60 and the 4 th hole 14 to reach the 2 nd flat surface 17. The inside of the barrel 93 can be penetrated by a power supply cable or the like.

The operation of the gear transmission 1 of the present embodiment will be described. In the gear transmission device 1, when the input shaft 31 rotates due to the rotation of the drive shaft of a motor, not shown, in the rotation direction changing mechanism 20, the 1 st gear 32 rotates integrally with the input shaft 31. The rotation of the 1 st gear 32 rotates the 2 nd gear 42 of the relay shaft 41, and the relay shaft 41 rotates. Thereby, the 3 rd gear 43 also rotates. When the rotation of the input shaft 31 is transmitted from the 1 st gear 32 to the 2 nd gear 42, the rotation direction is changed by the 1 st gear 32 and the 2 nd gear 42.

The rotation of the relay shaft 41 is input from the 4 th gear 62 to the intermediate gear mechanism 60, and the rotation speed is converted and then output from the 5 th gear 65. Then, the rotation of the 5 th gear 65 is transmitted to the crankshaft 81 via the 6 th gear 83. The crankshaft 81 rotates about its central axis, and the eccentric bodies 81a and 81b revolve around the central axis. When the eccentric bodies 81a and 81b revolve, the external gears 82a and 82b revolve while being meshed with the internal gear 90 via the internal pins. In the present embodiment, the rotation of the external gears 82a,82b is restrained. Accordingly, when the external gears 82a and 82b revolve while meshing with the internal gear 90, the internal gear 90 rotates due to the difference in the number of teeth between the external gears 82a and 82b and the internal gear 90.

(Effect)

In the gear transmission 1 of the present embodiment described above, the 1 st gear 32 and the 2 nd gear 42 are rotatably supported by the main casing 10 in the rotation direction changing mechanism 20. Specifically, the 1 st gear 32 is provided on the input shaft 31, rotates integrally with the input shaft 31, the 2 nd gear 42 is provided on the relay shaft 41, rotates integrally with the relay shaft 41, and the relay shaft 41 is disposed in a posture orthogonal to the input shaft 31. The input shaft 31 is rotatably supported by the main housing 10 via a 1 st main bearing 33, and the 1 st main bearing 33 is provided in an input shaft bearing hole 11A formed in the main housing 10, whereby the 1 st gear 32 is rotatably supported by the housing 10. The relay shaft 41 is rotatably supported by the main casing 10 via a 2 nd sub-bearing 44, and the 2 nd sub-bearing 44 is provided in a relay shaft bearing hole 12C formed in the main casing 10, whereby the 2 nd gear 42 is rotatably supported by the main casing 10.

According to this configuration, the 1 st gear 32 and the 2 nd gear 42 in the rotation direction changing mechanism 20 are rotatably supported by the common main casing 10, and thus elements interposed between the main casing 10 and the 1 st gear 32 and the 2 nd gear 42 are suppressed, and thus tolerance accumulation is suppressed. As a result, the meshing accuracy of the pair of gears meshing in an orthogonal state for changing the rotation direction can be improved, and the labor and time required for the adjustment work for obtaining the desired accuracy can be reduced, and the assembly cost can be reduced.

In particular, since the inner ring and the outer ring of the bearing are usually precisely machined, the machining cost for obtaining a desired centering state can be suppressed even if the inner peripheral surface of the input shaft bearing hole 11A is inserted into the outer peripheral surface of the 1 st main bearing 33 and the input shaft 31 is supported by the inner peripheral surface of the 1 st main bearing 33.

The 1 st gear 32 is located inside the main housing 10 with respect to the 1 st main bearing 33 provided in the input shaft bearing hole 11A, and the input shaft 31 extends from the 1 st main bearing 33 to the outside of the main housing 10. A sub-housing 35 covering the input shaft 31 is provided radially outside of a portion of the input shaft 31 extending from the 1 st main bearing 33 to the outside of the main housing 10, and the sub-housing 35 is locked to a portion of the 1 st main bearing 33 protruding from the input shaft bearing hole 11A. As a result, according to the present embodiment, the 1 st main bearing 33 can be used for positioning the sub-housing 35, and therefore, there is an effect that workability of assembly can be improved.

While the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment.

For example, in the above embodiment, the following structure is described: the rotation of the external gears 82a,82b is restrained by restraining the rotation of the carrier 85a, and the internal gear 90 rotates. However, the present invention can also be applied to a structure in which the carriers 85a, 85b rotate by restraining the rotation of the internal gear 90.

Claims

1. A gear transmission device, wherein,

the gear transmission device includes:

a rotation direction changing mechanism;

a speed reducing mechanism;

a main casing to which the rotation direction changing mechanism and the speed reducing mechanism are attached; and

an intermediate gear mechanism interposed between the rotation direction changing mechanism and the reduction mechanism,

the rotation direction conversion mechanism has a 1 st gear and a 2 nd gear which is disposed in an orthogonal posture to the 1 st gear and is meshed with the 1 st gear,

the reduction mechanism has an output shaft from which rotation transmitted from the 1 st gear to the 2 nd gear is output,

the 1 st gear is arranged on the input shaft and rotates integrally with the input shaft,

the 2 nd gear is provided on a relay shaft, rotates integrally with the relay shaft, is disposed in a posture orthogonal to the input shaft,

the main housing has an input shaft bearing hole into which the input shaft is inserted and a relay shaft bearing hole into which the relay shaft is inserted,

the 1 st gear is rotatably supported by the main housing by rotatably supporting the input shaft in the bearing hole for the input shaft, the 2 nd gear is rotatably supported by the main housing by rotatably supporting the relay shaft in the bearing hole for the relay shaft,

the bearing hole for the intermediate shaft is arranged at a position overlapping with the 1 st gear when viewed in the axial direction of the input shaft,

the 2 nd gear is arranged between one end part and the other end part of the relay shaft, one end part of the relay shaft is inserted into the bearing hole for the relay shaft,

the rotation transmitted from the 1 st gear to the 2 nd gear is transmitted from the position of the relay shaft on the other end side than the 2 nd gear to the reduction mechanism,

the main housing has a flat surface on which the reduction mechanism and the positioning of the reduction mechanism are placed on the opposite side of the 2 nd gear side via the bearing hole for the relay shaft, the reduction mechanism is placed on the flat surface,

a 3 rd gear is arranged between one end part and the other end part of the relay shaft, the 2 nd gear is arranged on one end part side of the relay shaft, the 3 rd gear is arranged on the other end part side of the relay shaft,

the intermediate gear mechanism has: a 4 th gear engaged with the 3 rd gear; an annular flange portion fixed to an inner peripheral edge portion of the 4 th gear on the flat surface side and extending toward a side separated from the 4 th gear; a cylindrical shaft portion extending from an inner peripheral edge portion of the flange portion; a 5 th gear provided on an outer peripheral portion of a distal end portion of the shaft portion,

the 5 th gear transmits rotation to the reduction mechanism,

the 4 th gear is rotatably supported by a center bearing provided on the outer peripheral surface of the peripheral wall portion of the main casing.

2. The gear assembly of claim 1, wherein,

the input shaft is rotatably supported by a bearing provided in the input shaft bearing hole, and the relay shaft is rotatably supported by a bearing provided in the relay shaft bearing hole.

3. The gear assembly of claim 2, wherein,

at least one of the bearings provided in the bearing holes for the input shaft is provided so as to partially protrude from the corresponding bearing hole.

4. A gear assembly according to claim 3, wherein,

the bearing provided in the bearing hole for the input shaft is provided so as to partially protrude from the bearing hole for the input shaft,

the 1 st gear is located at a position closer to the inner side of the main housing than the bearing provided in the bearing hole for the input shaft, the input shaft extends from the bearing provided in the bearing hole for the input shaft to the outside of the main housing,

a sub-housing covering the input shaft is provided radially outside of a portion of the input shaft extending from the bearing to the outside of the main housing,

the sub-housing is engaged with the protruding portion of the bearing.