Power transmission device, speed reducer, industrial machine, and method of disassembling industrial machine for maintenance

Abstract

To provide a power transmission device which can achieve good maintainability and enables reduction of an entire length in a state that a motor is connected thereto, and to provide a speed reducer, an industrial machine, and a method of disassembling an industrial machine for maintenance.SOLUTION: A power transmission device includes a casing 13, an output rotating body, an input shaft 30, a power transmission mechanism, a shaft seal portion, a casing seal portion, and an end cover 34. The shaft seal portion seals a space between a through hole of the output rotating body and the input shaft 30. The casing seal portion seals a space between the casing 13 and the output rotating body. The end cover 34 is attached to an axial end at the side, with which a transmitted member is connected, of the output rotating body and shields the inside of the end from the outside.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a power transmission device, a reducer, an industrial machine, and a method for disassembly and maintenance of the industrial machine. [Background technology]

[0002] 2. Description of the Related Art A known drive unit used in industrial machinery such as a welding robot has a motor and a reducer that reduces the rotation speed of the motor, which are fixed to a base member (see, for example, Patent Document 1).

[0003] In the drive unit described in Patent Document 1, a substantially cylindrical case of the reducer is fixed to a base member, and a motor arranged at the back of the reducer is fixed to the same base member via an adapter. The reducer includes the case having internal teeth on its inner circumferential surface, a carrier rotatably accommodated inside the case, a crankshaft rotatably supported by the carrier and having an eccentric region that orbits and rotates in response to the rotation of the motor, and an oscillating gear having external teeth with a smaller number of teeth than the internal teeth of the case, meshing with the internal teeth of the case and oscillatingly rotating in response to a rotational force from the eccentric region of the crankshaft. When the oscillating gear oscillates in response to a rotational force from the eccentric region of the crankshaft, its rotation component is output to the carrier via the crankshaft. As a result, the rotation of the motor is decelerated and output to the carrier.

[0004] The carrier of the reducer is fixed at one axial end face (the end face opposite the motor) to a member to which force is to be transmitted, such as a rotating arm of a robot, by bolting. The space between the case of the reducer and the carrier is sealed by a case seal member at the end area on the same side as the member to which force is to be transmitted, and the center hole and crank hole in the end face of the carrier on the same side are sealed by a sealing member. The interior of the reducer and the space surrounded by the adapter and motor facing the end face of the reducer are filled with lubricating liquid to lubricate the mechanical parts inside and outside the reducer. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-38809 Summary of the Invention [Problem to be solved by the invention]

[0006] The reducer described in Patent Document 1 can be separated from the power receiving member while still connected to the motor during maintenance, etc. At this time, the lubricating liquid filled inside the reducer and the adapter does not need to be discharged to the outside, so maintenance work can be performed relatively easily. However, in the reducer described in Patent Document 1, the adapter for fixing the motor to the base member also serves as the lubricating liquid sealing space at the end of the reducer, so the overall length of the reducer when connected to the motor is long. In a power transmission device including this type of reducer, it is desirable to adopt a structure that does not require draining of lubricating fluid during maintenance, while also being able to shorten the overall length of the entire machine when the motor is connected.

[0007] The present invention provides a power transmission device, a reducer, an industrial machine, and a disassembly maintenance method for an industrial machine, which have good maintainability and can further shorten the overall length when a motor is connected. [Means for solving the problem]

[0008] A power transmission device according to one embodiment of the present invention comprises a case fixed to a base member, an output rotor having an axial through hole that is rotatably housed inside the case and has one axial end that serves as a connecting part for connecting a connected member, an input shaft that is inserted into the through hole and connected to a rotating shaft of a motor, a power transmission mechanism that is disposed inside the case surrounded by the output rotor and transmits rotation of the input shaft to the output rotor, a shaft seal that seals the space between the through hole and the input shaft, a case seal that seals the space between the case and the outer peripheral surface of the output rotor, and an end cover that is attached to the end of the output rotor that is the connecting part and that shields the inside of the end from the outside.

[0009] With the above configuration, the inside of the power transmission device is sealed by the shaft seal, case seal, and end cover. This prevents the lubricating liquid filled inside the power transmission device from leaking. Because the inside of the power transmission device is sealed by the power transmission device alone in this way, it becomes possible to connect a motor to the power transmission device without using an adapter. Therefore, when a power transmission device with this configuration is used, it becomes possible to further shorten the overall length when the motor is connected.

[0010] a crankshaft that is rotatably supported inside the carrier and has an eccentric region that orbits in response to the rotation of the input shaft; an oscillating gear that is disposed between first and second outer peripheral surfaces spaced apart in the axial direction of the carrier, and that oscillates together with the eccentric region of the crankshaft and outputs reduced rotation to the carrier while meshing with the internal teeth; a shaft seal that seals between the through hole and the input shaft; a case seal that seals between the case and the first outer peripheral surface and between the case and the second outer peripheral surface; and an end cover that is attached to the end of the carrier that is the connecting portion and that shields the inside of the end from the outside.

[0011] With the above configuration, the inside of the reducer is sealed by the shaft seal, case seal, and end cover. This prevents the lubricating liquid filled inside the reducer from leaking. Because the inside of the reducer is sealed by the reducer alone in this way, it becomes possible to connect the motor to the reducer without using an adapter. Therefore, when a reducer with this configuration is used, it becomes possible to further shorten the overall length when the motor is connected.

[0012] The end of the carrier on the side of the connection portion may be provided with a recess in which a transmission rotor that transmits rotation of the input shaft to the crankshaft is disposed, and the end cover may be attached to the peripheral portion of the recess so as to cover the end of the recess.

[0013] In this case, a recess in which the transmission rotor is disposed is provided at the axial end of the carrier, and an end cover is attached to the outer circumferential edge of the recess, thereby making it possible to seal one axial end of the carrier. Therefore, when this configuration is adopted, one axial end of the carrier can be sealed with an end cover of a simple shape that does not occupy a large amount of space in the axial direction, making it possible to shorten the axial length of the reducer and facilitate its manufacture.

[0014] An axial end portion of the carrier opposite to the connecting portion may be a motor fixing portion to which a motor case of the motor is fixed.

[0015] In this case, the motor is fixed to the motor fixing portion of the carrier, and when the motor is driven in this state, the motor rotates integrally with the carrier, while the reduced rotation is transmitted from the carrier to the connected member. When this configuration is adopted, the motor is fixed directly to the axial end (motor fixing part) of the carrier, so that the axial length of the entire device with the motor connected to the reducer can be shortened compared to when the motor is fixed to the base member via an adapter.

[0016] The input shaft may be provided with a connecting portion that protrudes from the motor fixing portion and is connected to the rotating shaft inside the motor so as to be non-rotatable relative to the rotating shaft.

[0017] In this case, since the input shaft is connected to the rotating shaft of the motor inside the motor, the shaft seal member that seals the gap between the shaft hole and the input shaft can be positioned closer to the motor, which makes it possible to further shorten the axial length of the carrier.

[0018] The connecting portion and the rotating shaft may be connectable by spline fitting.

[0019] In this case, when the motor is fixed to the motor fixing portion of the carrier, the end of the input shaft can be easily connected to the rotating shaft of the motor by inserting the end of the input shaft into the motor. Therefore, when this configuration is adopted, it is easy to assemble the motor to the reducer.

[0020] The carrier includes a first carrier block having a plurality of support pillars arranged approximately along the axial direction on an axial end face of a perforated disc-shaped base portion, a second carrier block formed in a perforated disc shape with the support pillars abutting one axial end face of the first carrier block, and a fastening member which fastens the second carrier block to the support pillars from the other axial end face of the second carrier block, and the motor fixing portion may be provided on the end of the base portion opposite to the side on which the support pillars are arranged.

[0021] In this case, the motor is fixed to the base plate of the first carrier block where the fastening members for fastening the support columns of the first carrier block to the second carrier block are not located. Therefore, the fastening members for fastening the motor to the carrier do not interfere with the fastening members for fastening the support columns of the first carrier block to the second carrier block. Therefore, when this configuration is adopted, it is no longer necessary to extend the axial length of the carrier to avoid the above-mentioned interference, and the axial length of the reducer can be shortened accordingly.

[0022] An industrial machine according to one aspect of the present invention is an industrial machine including a motor, a reducer for reducing the rotation speed of the motor, a base member to which the reducer is fixed, and a transmitted member that rotates upon receiving the output of the reducer, the reducer including a case fixed to the base member and having internal teeth on an inner peripheral surface, a carrier having a through hole penetrating in the axial direction and rotatably housed inside the case, one end in the axial direction being a connecting portion to which a connected member is connected, an input shaft rotatably inserted into the through hole and connected to a rotating shaft of the motor, a crankshaft rotatably supported inside the carrier and having an eccentric region that orbits and rotates upon receiving the rotation of the input shaft, and a first outer peripheral surface and a second outer peripheral surface spaced apart in the axial direction of the carrier. the input shaft includes an oscillating gear disposed between the eccentric region of the crankshaft and the input shaft, which oscillates and rotates together with the eccentric region of the crankshaft and outputs reduced rotation to the carrier while meshing with the internal teeth; a shaft seal portion which seals between the through hole and the input shaft; a case seal portion which seals between the case and the first outer peripheral surface and between the case and the second outer peripheral surface; and an end cover attached to the end of the carrier on the side which is the connecting portion and which shields the inside of the end from the outside, wherein the axial end of the carrier on the side opposite to the side which is the connecting portion is a motor fixing portion to which the motor is fixed, and the input shaft is provided with a connecting portion which protrudes from the motor fixing portion and is connected to the rotating shaft inside the motor so as not to rotate relative to the rotating shaft.

[0023] With the above configuration, the inside of the reducer is sealed by the shaft seal, case seal, and end cover. This prevents the lubricating liquid filled inside the reducer from leaking. Because the inside of the reducer is sealed by the reducer alone in this way, it becomes possible to connect the motor to the reducer without using an adapter. Therefore, when an industrial machine with this configuration is used, it becomes possible to further shorten the overall length when the motor is connected.

[0024] A disassembly and maintenance method for industrial machinery according to one aspect of the present invention is an industrial machinery including a motor, a reducer for reducing the rotation of the motor, a base member to which the reducer is fixed, and a transmitted member that rotates by receiving an output of the reducer, wherein the reducer includes a case fixed to the base member and provided with internal teeth on an inner peripheral surface, a carrier having a through hole penetrating in the axial direction and rotatably housed inside the case, with one end in the axial direction serving as a connecting portion to which a connected member is connected, an input shaft rotatably inserted into the through hole and connected to a rotating shaft of the motor, a crankshaft rotatably supported inside the carrier and having an eccentric region that orbitally rotates by receiving the rotation of the input shaft, an oscillating gear that is arranged between a first outer circumferential surface and a second outer circumferential surface spaced apart from each other in the axial direction of the carrier, and that oscillates together with the eccentric region of the crankshaft and outputs reduced rotation to the carrier while meshing with the internal teeth, a shaft seal portion that seals between the through hole and the input shaft, and a shaft seal portion that seals between the through hole and the input shaft, and a case seal part that seals between the case and the first outer peripheral surface and between the case and the second outer peripheral surface, and an end cover that is attached to an end of the carrier on the side that is the connecting part and that shields the inside of the end from the outside, an axial end of the carrier on the side opposite to the connecting part is a motor fixing part to which the motor is fixed, and the input shaft is provided with a connecting part that protrudes from the motor fixing part and is connected to the rotating shaft inside the motor so as not to rotate relatively. The disassembly and maintenance method for an industrial machine includes a temporary fixing step of attaching a fixing jig to the base member and the force-receiving member to fix the force-receiving member to the base member, a first fastening release step of releasing the force-receiving member from the carrier after the temporary fixing step, a second fastening release step of releasing the force-receiving member from the base member after the temporary fixing step, and a step of removing the reducer together with the motor from the base member after the first fastening release step and the second fastening release step.

[0025] When disassembling an industrial machine using the above method, the reducer can be removed from the base member together with the motor while the force-receiving member is fixed to the base member by the fixing jig. In this case, since the force-receiving member does not need to be removed from the base member, the work of removing the reducer for maintenance can be easily performed even if the force-receiving member is a long or heavy object. In addition, when removing the reducer, there is no need to drain the lubricating liquid for lubricating the machine parts from the reducer, which also greatly contributes to facilitating disassembly for maintenance. Effect of the Invention

[0026] In the above-mentioned power transmission device, reducer, and industrial machine, the inside of the power transmission device (reducer) itself can be sealed by the shaft seal, case seal, and end cover. Therefore, the motor can be connected to the power transmission device (reducer) without using an adapter that also serves as a lubricant filling section. Therefore, the overall length of the motor connected can be shortened while maintaining good maintainability.

[0027] The above-mentioned disassembly and maintenance method for industrial machinery makes it possible to remove the reducer together with the motor from the base member without removing the force-receiving member from the base member, thereby facilitating disassembly work for maintenance of the industrial machinery. [Brief description of the drawings]

[0028] [Figure 1] FIG. 1 is a vertical cross-sectional view of an industrial robot according to an embodiment. [Diagram 2] FIG. 2 is an enlarged cross-sectional view of a reducer used in the industrial robot according to the embodiment. [Diagram 3] 4 is a vertical cross-sectional view showing one step of a disassembly maintenance method for an industrial robot according to an embodiment. FIG. [Figure 4] 10A to 10C are vertical cross-sectional views showing other steps of the disassembly maintenance method for the industrial robot according to the embodiment. [Diagram 5] 13 is a vertical cross-sectional view showing still another process of the disassembly maintenance method for the industrial robot according to the embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Next, an embodiment of the present invention will be described with reference to the drawings.

[0030] FIG. 1 is a vertical cross-sectional view of an industrial robot 1, which is one form of industrial machinery. The industrial robot 1 of this embodiment is a multi-joint robot having multiple rotatable joints. A base portion on the lower end side of the industrial robot 1 is rotatably connected to a base member 2 that is fixed to an installation surface such as a floor, and a rotating arm 3 on the base side. A drive unit 10 is provided at the connection portion between the base member 2 and the rotating arm 3 for operating the rotating arm 3 under the control of a controller (not shown). The drive unit 10 includes a driving motor 11 and a reducer 12 that reduces the speed of rotation of the motor 11. The base portion of the rotating arm 3 is connected to the output side of the reducer 12.

[0031] FIG. 2 is an enlarged cross-sectional view of the reducer 12 of FIG. As shown in FIG. 2, the reducer 12 includes a case 13 having a generally cylindrical shape, a first carrier block 14A and a second carrier block 14B rotatably held on the inner surface of the case 13, an input shaft 30 that axially penetrates the center of the first carrier block 14A and the second carrier block 14B and has one axial end connected to the rotating shaft 11a of the motor 11, multiple (e.g., three) crankshafts 15 rotatably supported on the first carrier block 14A and the second carrier block 14B, and a first oscillating gear 16A and a second oscillating gear 16B that revolve together with the two eccentric regions 15a, 15b of each crankshaft 15. In this embodiment, the first carrier block 14A and the second carrier block 14B constitute a carrier that is an output rotating body. In addition, in this embodiment, the first oscillating gear 16A and the second oscillating gear 16B are provided as oscillating gears, but the number of oscillating gears is not limited to two. It may be one or three or more.

[0032] For ease of explanation, the axial side of the input shaft 30 to which the motor 11 is connected is referred to as the "first end side," and the opposite side is referred to as the "second end side." The first carrier block 14A has a disk-shaped base plate 14Aa with holes and a plurality of support columns 14Ab extending in the axial direction from the end face of the base plate 14Aa toward the second carrier block 14B. The second carrier block 14B is formed in a disk-shaped shape with holes. The end faces of the support columns 14Ab of the first carrier block 14A are butted against the end faces of the second carrier block 14B, and each support column 14Ab is fastened and fixed to the second carrier block 14B by bolts 17, which are fastening members. The bolts 17 are fastened from the second end side of the second carrier block 14B toward the corresponding support column 14Ab. The first carrier block 14A is disposed on the first end side inside the case 13, and the second carrier block 14B is disposed on the second end side inside the case 13. Reference numeral 18 in the drawing denotes a positioning pin for positioning the second carrier block 14B to each support portion 14Ab before fastening with the bolts 17.

[0033] The through hole 29a formed at the center of the base plate portion 14Aa of the first carrier block 14A and the through hole 29b formed at the center of the second carrier block 14B are shaft holes into which the input shaft 30 is inserted. Hereinafter, these through holes 29a and 29b are referred to as "shaft holes 29a and 29b". The input shaft 30 is rotatably supported in the shaft hole 29a on the first carrier block 14A side via a bearing with a sealing function 70. The input shaft 30 is assembled so as to be concentric with the rotation center axis c1 of the first carrier block 14A and the second carrier block 14B. The bearing with a sealing function 70 liquid-tightly seals the gap between the inner peripheral surface of the shaft hole 29a and the input shaft 30. The bearing with a sealing function 70 is a bearing equipped with a shaft seal portion. In this embodiment, the bearing with sealing function 70 is used, but it is also possible to provide a bearing that rotatably supports the input shaft 30 and a shaft seal portion separately. In this embodiment, the shaft seal portion provided in the bearing with sealing function 70 seals the gap between the motor 11 side area (shaft hole 29a) of the shaft holes 29a, 29b and the input shaft 30.

[0034] An axial gap is provided between the base plate portion 14Aa of the first carrier block 14A and the second carrier block 14B. A first oscillating gear 16A and a second oscillating gear 16B are disposed in this gap. The first oscillating gear 16A and the second oscillating gear 16B are formed with escape holes 19 through which the support pillars 14Ab of the first carrier block 14A penetrate. The escape holes 19 are formed sufficiently larger than the outer surface shape of the support pillars 14Ab so that the support pillars 14Ab do not interfere with the rotational movement of the first oscillating gear 16A and the second oscillating gear 16B.

[0035] The case 13 includes a cylindrical case body 13a and a flange portion 13b that protrudes radially outward from the outer circumferential surface of the case body 13a near the first end side. The case body 13a is disposed across the outer peripheral surface of the base plate portion 14Aa of the first carrier block 14A and the outer peripheral surface of the second carrier block 14B. The base plate portion 14Aa of the first carrier block 14A and the second carrier block 14B are rotatably supported via bearings 20 in both axial regions of the case body 13a. In addition, a plurality of pin grooves 21 extending parallel to the rotation center axis c1 of the first and second carrier blocks 14A and 14B are formed on the inner peripheral surface of the central region in the axial direction of the case body 13a (region facing the outer peripheral surfaces of the first oscillating gear 16A and the second oscillating gear 16B). A substantially cylindrical internal tooth pin 22 is rotatably accommodated in each pin groove 21. The plurality of internal tooth pins 22 attached to the inner peripheral surface of the case body 13a face the respective outer peripheral surfaces of the first oscillating gear 16A and the second oscillating gear 16B. In this embodiment, the internal tooth pin 22 constitutes internal teeth that are arranged on the inner circumferential surface of the case 13 .

[0036] 1, the base member 2 includes a base main body 2a that is fixed to an installation surface, and a retaining wall 2b that protrudes upward from the base main body 2a. A substantially circular support hole 90 is formed in the retaining wall 2b. The outer peripheral surface of the case main body 13a on the reducer 12 side is fitted into the support hole 90. The flange portion 13b of the case 13 is abutted against an axial end face of the retaining wall 2b when the case body 13a is fitted into the support hole 90. In this state, the flange portion 13b is fastened and fixed to the retaining wall 2b by bolts 27, which are fastening members.

[0037] The first oscillating gear 16A and the second oscillating gear 16B are formed with an outer diameter slightly smaller than the inner diameter of the case body 13a. External teeth 16Aa, 16Ba that mesh with and contact multiple internally toothed pins 22 arranged on the inner peripheral surface of the case body 13a are formed on the outer peripheral surfaces of the first oscillating gear 16A and the second oscillating gear 16B. The number of teeth of the external teeth 16Aa, 16Ba formed on the outer peripheral surfaces of the first oscillating gear 16A and the second oscillating gear 16B is set to be slightly less (for example, one less) than the number of the internally toothed pins 22 (pin grooves 21).

[0038] The crankshafts 15 are arranged on the same circumference centered on the rotational central axis c1 of the first carrier block 14A and the second carrier block 14B. Each crankshaft 15 is rotatably supported by the first carrier block 14A and the second carrier block 14B via a bearing 23. A pair of shaft support regions are arranged in each crankshaft 15, spaced apart in the axial direction, and two eccentric regions 15a, 15b are arranged between the pair of shaft support regions. The first carrier block 14A is formed with a shaft support hole 31a into which one of the shaft support regions of each crankshaft 15 is inserted, and the second carrier block 14B is formed with a shaft support hole 31b into which the other of the shaft support regions of each crankshaft 15 is inserted. A spur gear 26 for transmitting the rotation of the input shaft 30 to the crankshaft 15 is attached to the end of the crankshaft 15 protruding from the shaft support hole 31b of the second carrier block 14B toward the second end side. The spur gear 26 meshes with external teeth 30 a formed on the outer circumferential surface of the input shaft 30 on the second end side. In this embodiment, the spur gear 26 constitutes a transmission rotor for transmitting the rotation of the input shaft 30 to the crankshaft 15. The transmission rotor is not limited to the spur gear 26, but may be any rotor capable of transmitting the rotation of the input shaft 30 to the crankshaft 15. For example, it may be a rotor that comes into frictional contact with the outer circumferential surface of the input shaft 30.

[0039] The two eccentric regions 15a, 15b of the crankshaft 15 have their respective central axes eccentric to the central axis of the shaft support region. The two eccentric regions 15a, 15b are eccentric so that they are out of phase with each other by 180° around the central axis of the shaft support region (the central axis of the crankshaft 15). Each of the eccentric regions 15a, 15b of the crankshaft 15 penetrates the first oscillating gear 16A and the second oscillating gear 16B, respectively. Each of the eccentric regions 15a, 15b is rotatably engaged with a support hole 25 formed in each of the first oscillating gear 16A and the second oscillating gear 16B via an eccentric bearing 28 (cylindrical roller bearing).

[0040] In the reducer 12 of this embodiment, when the multiple crankshafts 15 rotate in one direction by receiving the rotation of the input shaft 30, the eccentric regions 15a, 15b of the crankshafts 15 revolve in the same direction at a predetermined radius, and accordingly the first oscillating gear 16A and the second oscillating gear 16B revolve (oscillate) in the same direction at the same radius. At this time, the external teeth 16Aa, 16Ba of the first oscillating gear 16A and the second oscillating gear 16B come into contact with the multiple internal tooth pins 22 held on the inner circumference of the case main body 13a so as to mesh with them.

[0041] In the reducer 12 of this embodiment, the number of teeth of each of the external teeth 16Aa, 16Ba of the first oscillating gear 16A and the second oscillating gear 16B is set to be slightly less than the number of the internal tooth pins 22 on the case body 13a side, so that while the first oscillating gear 16A and the second oscillating gear 16B make one revolution, the first oscillating gear 16A and the second oscillating gear 16B receive a reaction force in the rotational direction from the internal tooth pins 22 on the case body 13a side, and rotate by a predetermined pitch in the direction opposite to the revolution direction. As a result, the first and second carrier blocks 14A, 14B engaged with the first oscillating gear 16A and the second oscillating gear 16B via the crankshaft 15 rotate in the same direction and at the same pitch together with the first and second oscillating gears 16A, 16B. As a result, the rotation of the input shaft 30 is reduced to a predetermined reduction ratio and output as the rotation of the first and second carrier blocks 14A, 14B. In this embodiment, the two eccentric regions 15a, 15b of the crankshaft 15 are eccentric so as to be shifted by 180° around the axis, so the rotation phases of the first oscillating gear 16A and the second oscillating gear 16B are shifted by 180°. In this embodiment, the spur gear 26, the crankshaft 15, the first and second oscillating gears 16A, 16B, etc. constitute a power transmission mechanism that is surrounded by the first and second carrier blocks 14A, 14B, which are output rotors. The power transmission mechanism transmits the rotation of the input shaft 30 to the first and second carrier blocks 14A, 14B, which are output rotors.

[0042] A circular recess 33 is formed on the end face of the second end side of the second carrier block 14B, in which the multiple spur gears 26 at the ends of the crankshafts 15 are accommodated. The outer peripheral edge of the recess 33 protrudes toward the second end side from the bottom surface of the recess 33. The central area of ​​the bottom surface of the recess 33 communicates with the shaft hole 29b of the second carrier block 14B. A flat end cover 34 is attached to the outer peripheral edge of the recess 33 protruding toward the second end side from the bottom surface of the recess 33, covering the recess 33 and the shaft hole 29b from the second end side. In this state, the end cover 34 covers the power transmission part between the input shaft 30 and the spur gear 26 and the end of the shaft hole 29b from the second end side. The end cover 34 is formed of, for example, a flat metal plate. The gap between the end cover 34 and the end face of the outer periphery of the recess 33 is sealed by an annular seal member (not shown).

[0043] A plurality of screw holes 35 are provided on the outer peripheral edge of the recess 33 of the second carrier block 14B. The base end face of the rotating arm 3 shown in FIG. 1 is placed from the second end side on a flat end cover 34 attached to the end face of the second carrier block 14B, and the rotating arm 3 is fixed to the end face of the second carrier block 14B by a plurality of bolts 36 which are fastening members. The bolts 36 are fastened into the screw holes 35 on the second carrier block 14B side to fix the rotating arm 3 to the second carrier block 14B.

[0044] Between the end area on the first end side of the case body 13a and the outer circumferential surface 14Aap (first outer circumferential surface) of the substrate portion 14Aa of the first carrier block 14A, a case seal member 44 (case seal portion) that seals the space between them liquid-tight is provided. The case seal member 44 may be fixed to either one of the case body 13a or the substrate portion 14Aa, and the seal portion may be slidably in close contact with the other. In addition, between the end area on the second end side of the case body 13a and the outer circumferential surface 14Bp (second outer circumferential surface) of the second carrier block 14B, a similar case seal member 44 (case seal portion) that seals the space between them liquid-tight is provided. The outer circumferential surface 14Aap of the substrate portion 14Aa on which one case seal member 44 is arranged and the outer circumferential surface 14Bp of the second carrier block 14B on which the other case seal member 44 is arranged are spaced apart in the axial direction of the carrier.

[0045] As described above, the internal space of the reducer 12 is sealed by the bearing 70 with sealing function (shaft seal member), the end cover 34, and the case seal member 44. The internal space of the reducer 12 is filled with a lubricating liquid for lubricating the mechanical parts inside the reducer 12.

[0046] The motor 11 also includes a motor case 50 that houses the motor's rotation drive unit, and a rotating shaft 11a that is connected to the motor's drive unit. The motor case 50 is provided with a mounting flange 52 at an end on the output side, and the mounting flange 52 is formed with a plurality of insertion holes 53. The motor case 50 has an output side end face butted against an end face on the first end side of the first carrier block 14A (substrate part 14Aa) of the reducer 12, and in this state, the motor case 50 is fastened and fixed to the first carrier block 14A by bolts 54 whose shaft parts are inserted into the insertion holes 53. A screw hole 55 into which the bolt 54 is fastened is formed in the end face on the first end side of the first carrier block 14A. In this embodiment, an end portion (an end portion on the first end side) of the substrate portion 14Aa of the first carrier block 14A serves as a motor fixing portion.

[0047] The rotating shaft 11a is positioned inside the motor case 50 with respect to the output side end face of the motor case 50. In other words, the rotating shaft 11a is recessed inside the motor case 50. A shaft insertion hole 56 is formed in approximately the center of the output side end face of the motor case 50. A connecting portion 60 of the input shaft 30, which will be described later, is inserted into this shaft insertion hole 56. A circular fitting hole 57 is formed coaxially with the rotating shaft 11a in the output side end face of the rotating shaft 11a. A female spline is formed on the inner peripheral surface of the fitting hole 57.

[0048] On the other hand, the input shaft 30 on the reducer 12 side has an end on the first end side that protrudes outward beyond the end face on the first end side of the first carrier block 14A. This protruding portion serves as a connecting portion 60 that is connected to the rotating shaft 11a of the motor 11. A male spline is formed on the outer circumferential surface of the connecting portion 60. The connecting portion 60 is fitted into a fitting hole 57 of the rotating shaft 11a through a shaft insertion hole 56 of the motor case 50. The input shaft 30 and the rotating shaft 11a of the motor 11 are prevented from rotating relative to each other by the connecting portion 60 and the fitting hole 57 being spline-fitted.

[0049] The motor 11 has the output side end face of the motor case 50 brought close to the end face of the first end side of the first carrier block 14A, and the connecting portion 60 of the input shaft 30 is inserted into the shaft insertion hole 56 in the end face of the motor case 50. At this time, the motor case 50 is pressed toward the end face of the first carrier block 14A, so that the rotating shaft 11a on the motor 11 side is spline-fitted to the input shaft 30 on the reducer 12 side. Next, in this state, the motor case 50 is fixed to the end face of the first end side of the first carrier block 14A with a plurality of bolts 54.

[0050] In the drive unit 10 in which the motor 11 is assembled to the reducer 12 in this manner, the case 13 of the reducer 12 is fastened to the base member 2 with a bolt 27. The base end of the rotating arm 3 is fastened to the reducer 12 thus fixed to the base member 2 with a bolt 36. The base end of the rotating arm 3 is fixed to the end face on the second end side of the second carrier block 14B.

[0051] <Industrial robot operation> When the rotating arm 3 is rotated, the motor 11 is driven to rotate the input shaft 30 of the reducer 12 in a predetermined direction. The rotation of the input shaft 30 is transmitted to the crankshafts 15 via the spur gears 26. When each crankshaft 15 rotates, the first oscillating gear 16A and the second oscillating gear 16B rotate while meshing with the internal tooth pin 22 on the case 13 side, following the rotation of the eccentric regions 15a and 15b of the crankshaft 15. At this time, the rotation components of the first and second oscillating gears 16A and 16B are output to the rotating arm 3 via the second carrier block 14B. As a result, the output of the motor 11 is reduced to a predetermined reduction ratio by the reducer 12, and the reduced output is transmitted to the rotating arm 3. Since the motor case 50 of the motor 11 is fixed to an end face of the first carrier block 14A of the reducer 12, when the motor 11 is driven, the motor case 50 rotates integrally with the first carrier block 14A.

[0052] <Disassembly and maintenance of industrial robots> 3 to 5 are vertical cross-sectional views showing each step during disassembly and maintenance of the industrial robot 1. FIG. A disassembly and maintenance method for the industrial robot 1 (disassembly method for maintenance) will be described. This disassembly maintenance method includes the following steps (1) to (4). (1) Temporary fixing process (see Figure 3) A fixing jig 91 is attached to the base member 2 and the rotating arm 3, and the rotating arm 3 is fixed to the base member 2 by the fixing jig 91. This restricts the movement (falling, etc.) of the rotating arm 3. (2) First fastening release process (see Figure 4) After the temporary fixing step, the bolts 36 that fix the second carrier block 14B and the rotating arm 3 are removed. (3) Second fastening release process (see Figure 5) After the temporary fixing step, the bolts 27 fixing the case 13 and the base member 2 are removed. (4) Drive unit removal process (see Figure 5) The reducer 12 is removed together with the motor 11 from the base member 2 . When the reducer 12 and motor 11 are removed from the base member 2 using this disassembly maintenance method, the reducer 12 and motor 11 can be easily removed without removing the rotating arm 3 (receiving member), which is a heavy, long object, from the base member 2.

[0053] <Effects of the embodiment> As described above, the reducer 12 of this embodiment can seal the inside of the reducer 12 itself by the bearing 70 with sealing function (shaft seal portion), the case seal member 44 (case seal portion), and the end cover 34. Therefore, the motor 11 can be connected to the reducer 12 without using an adapter that also serves as a lubricant filling portion. Therefore, when the reducer 12 of this embodiment is employed, it is possible to further shorten the overall length with the motor 11 connected while maintaining good maintainability.

[0054] The reducer 12 of this embodiment is also a power transmission device that transmits the rotation of the motor 11 to the transmitted member (the rotating arm 3). The reduction mechanism housed inside the case 13 of the reducer 12 can be replaced with a power transmission mechanism that does not perform reduction in speed. In this case, too, the same effect as described above can be obtained by sealing the inside of the power transmission unit with the bearing 70 with sealing function (shaft seal portion), the case seal member 44 (case seal portion), and the end cover 34.

[0055] In addition, in the reducer 12 of this embodiment, a recess 33 in which a plurality of spur gears 26 are arranged is provided on the end face on the second end side of the second carrier block 14B (carrier), and the recess 33 communicates with the shaft hole 29b. The recess 33 is sealed by the end cover 34. As a result, the recess 33 and the end of the shaft hole 29b are covered from the second end side by the end cover 34. Therefore, when this configuration is adopted, the second end side of the second carrier block 14B can be sealed by the end cover 34 having a simple shape that does not occupy a large space in the axial direction, and the axial length of the reducer 12 can be shortened and the manufacture can be simplified.

[0056] In addition, in the reduction gear 12 of this embodiment, the end portion on the first end side of the first carrier block 14A is configured as a motor fixing portion to which the motor case 50 of the motor 11 is fixed. Therefore, when the motor 11 is driven with the motor case 50 fixed to the end portion of the first carrier block 14A, the motor case 50 rotates integrally with the first carrier block 14A, and the reduced rotation is transmitted from the second carrier block 14B to the rotating arm 3. Therefore, when this configuration is adopted, the motor case 50 is directly fixed to the end portion on the first end side of the first carrier block 14A, so that the axial length of the entire device can be further shortened when the motor 11 is connected to the reduction gear 12.

[0057] Furthermore, in the reducer 12 of this embodiment, a connecting portion 60 is provided at the end of the input shaft 30, which protrudes from the end face of the first carrier block 14A toward the first end side and is connected to the rotating shaft 11a of the motor 11 in the motor case 50 so as not to rotate relative to the input shaft 30. Therefore, compared to the case where the rotating shaft 11a protruding from the motor case 50 is connected to the input shaft 30 in the shaft hole 29a of the first carrier block 14A, the bearing 70 with a sealing function (shaft seal member) that seals the gap between the shaft hole 29a and the input shaft 30 can be disposed closer to the motor 11. Therefore, when this configuration is adopted, the axial length of the first carrier block 14A can be further shortened.

[0058] Furthermore, in the reducer 12 of this embodiment, the connecting portion 60 of the input shaft 30 and the rotating shaft 11a of the motor 11 are connected by spline fitting. Therefore, when fixing the motor case 50 to an end portion (motor fixing portion) of the first carrier block 14A, the connecting portion 60 of the input shaft 30 can be easily connected to the rotating shaft 11a of the motor 11 by inserting the end portion of the input shaft 30 into the shaft insertion hole 56 of the motor case 50. Therefore, when this configuration is adopted, the motor 11 can be easily assembled to the reducer 12.

[0059] In the reducer 12 of this embodiment, the carrier is composed of a first carrier block 14A having a support portion 14Ab protruding from an end face of a base portion 14Aa and a second carrier block 14B against which the support portion 14Ab abuts, and the second carrier block 14B and the support portion 14Ab are fastened and fixed by bolts 17 (fastening members) from the second end side of the second carrier block 14B. The motor fixing portion to which the motor 11 is fixed is provided on the base portion 14Aa of the first carrier block 14A where the bolts 17 are not arranged. Therefore, the bolts 54 (fixing members) for fixing the motor case 50 to the carrier do not interfere with the bolts 17 (fastening members) for fastening the support portion 14Ab and the second carrier block 14B. Therefore, when this configuration is adopted, there is no need to extend the axial length of the carriers (first carrier block 14A and second carrier block 14B) to avoid the above-mentioned interference, and as a result, it is possible to further shorten the axial length of the entire reducer 12.

[0060] Furthermore, the disassembly and maintenance method for the industrial robot 1 (industrial machine) of the present embodiment described above includes a temporary fixing step of fixing the base member 2 and the rotating arm 3 with the fixing jig 91, a first fastening release step of releasing the fastening between the second carrier block 14B and the rotating arm 3 after the temporary fixing step, a second fastening release step of releasing the fastening between the base member 2 and the case 13 of the reducer 12 after the temporary fixing step, and a step of removing the reducer 12 together with the motor 11 from the base member 2. Therefore, when disassembling the industrial robot 1 for maintenance, the reducer 12 can be removed together with the motor 11 from the base member 2 while the rotating arm 3 remains fixed to the base member 2 by the fixing jig 91. At this time, since it is not necessary to remove the rotating arm 3 from the base member 2, even if the rotating arm 3 is a long and heavy member, the work of removing the reducer 12 for maintenance can be easily performed. Furthermore, because the reducer 12 is a single unit with an internally sealed structure, there is no need to drain the lubricating liquid used to lubricate mechanical parts from the reducer 12 when removing the reducer 12. This also greatly contributes to facilitating disassembly for maintenance.

[0061] The present invention is not limited to the above-described embodiment, and various design modifications are possible without departing from the spirit and scope of the present invention. For example, the above embodiment employs the reducer 12 according to the embodiment in the arm operating section of an industrial robot, but the application of the reducer 12 is not limited to industrial robots. The reducer 12 can also be applied to industrial machines other than robots, such as turntables and rotating jigs. In this case, a plate-shaped or block-shaped rotating body can be used as the transmitted member connected to the output rotating body (carrier) instead of the rotating arm 3.

[0062] In addition, among the embodiments disclosed in this specification, those that are configured with multiple objects may be integrated, and conversely, those that are configured with one object may be divided into multiple objects. Regardless of whether they are integrated or not, it is sufficient that they are configured to achieve the object of the invention. [Explanation of symbols]

[0063] 1...industrial robot (industrial machine), 2...base member, 3...rotating arm (connected member), 11...motor, 11a...rotating shaft, 12...reduction gear, 13...case, 14A...first carrier block (carrier, output rotor), 14Aa...base plate portion, 14Aap...outer peripheral surface (first outer peripheral surface), 14Ab...support portion, 14B...second carrier block (carrier, output rotor), 14Bp...outer peripheral surface (second outer peripheral surface), 15...crankshaft a shaft hole, an input shaft, an end cover, a case seal member, a case seal portion, a connecting portion, a bearing with a sealing function, a shaft seal portion, a fixing jig, a fixing member ...

Claims

1. A case fixed to the base member; an output rotor having an axial through hole, rotatably housed inside the case, and having one axial end serving as a connecting portion to which a connected member is connected; an input shaft that is inserted into the through hole and connected to a rotating shaft of a motor; a power transmission mechanism that is disposed inside the case and is surrounded by the output rotor, and that transmits rotation of the input shaft to the output rotor; a shaft seal portion that seals between the through hole and the input shaft; a case seal portion that seals a gap between the case and an outer circumferential surface of the output rotor; an end cover attached to an end portion of the output rotor on the side of the coupling portion and shielding an inside of the end portion from the outside; A power transmission device comprising:

2. a case fixed to a base member and having internal teeth on an inner peripheral surface; a carrier having a through hole penetrating in an axial direction, rotatably housed inside the case, and having one end in the axial direction as a connecting portion to which a connected member is connected; an input shaft rotatably inserted into the through hole and connected to a rotating shaft of a motor; a crankshaft that is rotatably supported inside the carrier and has an eccentric region that orbitally rotates in response to the rotation of the input shaft; an oscillating gear disposed between a first outer peripheral surface and a second outer peripheral surface spaced apart from each other in the axial direction of the carrier, oscillatingly rotating together with the eccentric region of the crankshaft and outputting reduced rotation to the carrier while meshing with the internal teeth; a shaft seal portion that seals between the through hole and the input shaft; a case seal portion that seals between the case and the first outer peripheral surface and between the case and the second outer peripheral surface; an end cover attached to an end portion of the carrier on the side of the connection portion and shielding an inside of the end portion from the outside; A reducer comprising:

3. a recessed portion in which a transmission rotor that transmits rotation of the input shaft to the crankshaft is disposed is provided at the end portion of the carrier that is the coupling portion; The reducer according to claim 2 , wherein the end cover is attached to a peripheral portion of the recess so as to cover the end of the recess.

4. The reducer according to claim 2 , wherein an axial end of the carrier opposite to the connecting portion serves as a motor fixing portion to which the motor is fixed.

5. The reducer according to claim 4 , wherein the input shaft is provided with a connecting portion that protrudes from the motor fixing portion and is connected to the rotating shaft inside the motor so as to be non-rotatable relative to the rotating shaft.

6. The reducer according to claim 5 , wherein the connecting portion and the rotating shaft are connectable by spline fitting.

7. The carrier is a first carrier block having a plurality of support columns provided on an axial end surface of a perforated disk-shaped base portion, the support columns being arranged substantially along the axial direction; a second carrier block formed in a disk shape with a hole, one end face of which in an axial direction is abutted against the support portion; a fastening member that fastens and fixes the second carrier block to the support portion from the other end face side in the axial direction of the second carrier block, The reducer according to claim 4 , wherein the motor fixing portion is provided at an end of the base portion opposite to a side on which the support portion is arranged.

8. A motor; a reducer that reduces the rotation speed of the motor; A base member to which the reducer is fixed; A driven member that rotates by receiving the output of the reducer; An industrial machine comprising: The reducer includes: a case fixed to a base member and having internal teeth on an inner peripheral surface; a carrier having a through hole penetrating in an axial direction, rotatably housed inside the case, and having one end in the axial direction as a connecting portion to which a connected member is connected; an input shaft rotatably inserted into the through hole and connected to a rotating shaft of a motor; a crankshaft that is rotatably supported inside the carrier and has an eccentric region that orbitally rotates in response to the rotation of the input shaft; an oscillating gear disposed between a first outer peripheral surface and a second outer peripheral surface spaced apart from each other in the axial direction of the carrier, oscillatingly rotating together with the eccentric region of the crankshaft and outputting reduced rotation to the carrier while meshing with the internal teeth; a shaft seal portion that seals between the through hole and the input shaft; a case seal portion that seals between the case and the first outer peripheral surface and between the case and the second outer peripheral surface; an end cover attached to an end portion of the carrier on the side of the connection portion and shielding an inside of the end portion from the outside; Equipped with an axial end portion of the carrier opposite to the connecting portion serves as a motor fixing portion to which the motor is fixed; The input shaft is provided with a connecting portion that protrudes from the motor fixing portion and is connected to the rotating shaft inside the motor so as not to rotate relatively.

9. A motor; a reducer that reduces the rotation speed of the motor; A base member to which the reducer is fixed; A driven member that rotates by receiving the output of the reducer; An industrial machine comprising: The reducer includes: a case fixed to a base member and having internal teeth on an inner peripheral surface; a carrier having a through hole penetrating in an axial direction, rotatably housed inside the case, and having one end in the axial direction as a connecting portion to which a connected member is connected; an input shaft rotatably inserted into the through hole and connected to a rotating shaft of a motor; a crankshaft that is rotatably supported inside the carrier and has an eccentric region that orbitally rotates in response to the rotation of the input shaft; an oscillating gear disposed between a first outer peripheral surface and a second outer peripheral surface spaced apart from each other in the axial direction of the carrier, oscillatingly rotating together with the eccentric region of the crankshaft and outputting reduced rotation to the carrier while meshing with the internal teeth; a shaft seal portion that seals between the through hole and the input shaft; a case seal portion that seals between the case and the first outer peripheral surface and between the case and the second outer peripheral surface; an end cover attached to an end portion of the carrier on the side of the connection portion and shielding an inside of the end portion from the outside; Equipped with an axial end portion of the carrier opposite to the connecting portion serves as a motor fixing portion to which the motor is fixed; A disassembly and maintenance method for an industrial machine, the method comprising: providing a coupling portion on the input shaft, the coupling portion protruding from the motor fixing portion and coupled to the rotating shaft inside the motor so as not to rotate relatively thereto, the method comprising: a temporary fixing process of attaching a fixing jig to the base member and the force-receiving member to fix the force-receiving member to the base member; a first fastening release step of releasing the fastening of the force receiving member to the carrier after the temporary fixing step; a second fastening release step of releasing the fastening of the case from the base member after the temporary fixing step; a step of removing the reduction gear together with the motor from the base member after the first fastening / unfastening step and the second fastening / unfastening step; The disassembly maintenance method for an industrial machine is provided.

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