WO2020136890A1

WO2020136890A1 - Multijoint robot

Info

Publication number: WO2020136890A1
Application number: PCT/JP2018/048546
Authority: WO
Inventors: 慶早川
Original assignee: ヤマハ発動機株式会社
Priority date: 2018-12-28
Filing date: 2018-12-28
Publication date: 2020-07-02
Also published as: JP7199450B2; JPWO2020136890A1

Abstract

This multijoint robot is provided with: a base part; a first arm part rotatably coupled to the base part; and a second arm part rotatably coupled to the first arm part. The multijoint robot is provided with: a first motor and a second motor each provided in the base; a first power transmission mechanism that comprises a first speed reducer and transmits rotational force generated by the first motor to the first arm part; and a second power transmission mechanism that comprises a second speed reducer and transmits rotational force generated by the second motor to the second arm part via the first arm part. The first speed reducer is disposed between the base part and the first arm part, and the second speed reducer is disposed between the first arm part and the second arm part.

Description

Articulated robot

The present invention relates to an articulated robot.

An articulated robot is known as an industrial robot. Patent Document 1 discloses a SCARA robot (horizontal articulated robot) as an example of the articulated robot.

The SCARA robot disclosed in Patent Document 1 is capable of rotating at a base portion fixed on a base, a first arm portion rotatably supported by the base portion, and a tip end of the first arm portion. A second arm portion connected to the second arm portion, and an operation shaft held at the tip of the second arm portion so as to be vertically movable and rotatable about a vertical axis.

This SCARA robot is provided with a motor and a speed reducer for driving the first arm portion in the base portion, and a motor and a speed reducer for driving the second arm portion in the second arm portion, and an operating shaft. A motor for driving and a speed reducer are provided. An arch-shaped wiring pipe is provided between the base portion and the second arm portion, and wiring of electric parts such as a motor mounted on the second arm portion is provided from the second arm portion to the base through the wiring pipe. Is assigned to the department.

The above structure of the SCARA robot is typical of SCARA robots, but it has the following problems. That is, since the motor is mounted on the second arm portion, the weight of the second arm portion is relatively heavy and is easily affected by inertia, and a high-output motor is required to increase the driving speed. Even if the actuating shaft is omitted, it is difficult to make the second arm portion thin (thickness in the vertical direction), and the SCARA robot should be applied for the purpose of performing work by inserting the tip of the arm portion into a narrow space. Is difficult.

JP, 2005-85393, A

The present invention has been made in view of the above-described problems, and enables an articulated robot to be driven at a higher speed without increasing the output of a motor, and by making the arm portion thinner. The purpose is to expand the applications.

Further, according to the present invention, the base portion, the first arm portion rotatably connected to the base portion about the first rotation axis, and the first arm portion rotatable about the second rotation axis. A multi-joint robot including a second arm portion connected to the first arm, the first motor and the second motor respectively provided on the base, and a first reducer, and rotation generated by the first motor. A first power transmission mechanism that transmits a force to the first arm portion and a second speed reducer, and rotational force generated by the second motor is transmitted to the second arm portion via the first arm portion. A second power transmission mechanism for transmitting the second power transmission mechanism, wherein the first reduction gear is disposed between the base portion and the first arm portion, and the second reduction gear includes the first arm portion and the first arm portion. It is arranged between the two arm portions.

FIG. 1 is a side view of an industrial robot to which the articulated robot according to the present invention is applied. FIG. 2 is a sectional view of the industrial robot. FIG. 3 is a perspective view of the industrial robot (a state viewed from diagonally below). FIG. 4 is a perspective view of the industrial robot (a state viewed from diagonally below). FIG. 5 is an enlarged cross-sectional view of the industrial robot. FIG. 6 is an enlarged cross-sectional view of the industrial robot. FIG. 7 is an exploded perspective view of the industrial robot. FIG. 8 is a sectional view of the first speed reducer unit. FIG. 7 is a sectional view of the industrial robot showing the wiring structure. FIG. 10 is a bottom view of the industrial robot showing the wiring structure. FIG. 11 is a perspective view from above of the industrial robot showing the wiring structure. FIG. 12 is a detailed view showing the connector portion of the wiring structure.

1 to 4 show an industrial robot to which an articulated robot according to the present invention is applied. FIG. 1 is a side view, FIG. 2 is a sectional view, and FIGS. 3 and 4 are perspective views. 1 shows an industrial robot. In each drawing, an XYZ rectangular coordinate system is shown for convenience of description. In this example, the Z direction is the vertical direction.

The industrial robot 1 is a compound robot including a SCARA robot (horizontal articulated robot) 2 which is a kind of an articulated robot, and a single-axis robot 3 that linearly moves the SCARA robot 2. is there. In this example, the single-axis robot 3 moves (elevates) the SCARA robot 2 in the Z direction.

[Configuration of single-axis robot 3]
The uniaxial robot 3 includes a hollow casing 10 including a structure extending in the Z direction, a slider 12 movably supported along the casing 10 in the Z direction, and a drive mechanism 14 for driving the slider 12. Including and

The slider 12 is movably supported by a pair of guide rails (not shown) extending in the Z direction fixed to the inner wall surface of the casing 10. A slit-shaped opening 10a extending in the Z direction is formed on the side surface of the casing 10, and the slider 12 is exposed to the outside through the opening 10a.

The drive mechanism 14 is a so-called feed screw mechanism, and includes a nut member 12a incorporated in the slider 12, a screw shaft 16 inserted into the nut member 12a and extending parallel to the guide rail, and the screw shaft 16 And an electric motor 18 connected to one end of the. That is, the drive mechanism 14 rotates the screw shaft 16 by the motor 18 and converts the rotational movement of the screw shaft 16 into the linear movement of the slider 12 in the Z direction via the nut member 12a and the guide rail. With this configuration, the slider 12 moves in the Z direction.

[Structure of SCARA robot 2]
The SCARA robot 2 includes a base portion 20 and a robot arm 22 connected to the base portion 20. The base unit 20 is fixed to the slider 12 of the single-axis robot 3, and thus the SCARA robot 2 moves in the Z direction together with the slider 12 as the slider 12 moves.

The robot arm 22 is rotatably connected to the base unit 20 about a first rotation axis Ax1 and a first arm section 23 is rotatable about the second rotation axis Ax2. It is provided with a connected second arm portion 24 and a tool mounting portion 25 mounted on the second arm portion 24 so as to be rotatable around a third rotation axis Ax3. The tool mounting portion 25 is a portion to which an end effector according to various uses such as a robot hand is detachably mounted, and is provided at the tip end portion of the second arm portion 24. The first rotation axis Ax1, the second rotation axis Ax2, and a third rotation axis Ax3 described later are virtual axes that extend in the Z direction and are parallel to each other.

The SCARA robot 2 includes a first motor 31 that is a drive source for the first arm portion 23, and a first power transmission mechanism PT1 that transmits the rotational force generated by the first motor 31 to the first arm portion 23. ing. Further, the SCARA robot 2 includes a second motor 32 that is a drive source of the second arm portion 24, and a second power transmission mechanism PT2 that transmits the rotational force generated by the second motor 32 to the second arm portion 23. Is equipped with. Further, the SCARA robot 2 includes a third motor 33 that is a drive source of the tool mounting portion 25, and a third power transmission mechanism PT3 that transmits the rotational force generated by the third motor 31 to the tool mounting portion 25. There is.

All the first to third motors 31 to 33 are mounted on the base unit 20. The base portion 20 is provided with a casing 201 made of a hollow and box-shaped rigid structure having an opening at the bottom, and the motors 31 to 33 are arranged around the first rotation axis Ax1 as a center, and , Is fixed to the ceiling portion 202 of the casing 201 via the bracket. Specifically, the first motor 31 is arranged at a position adjacent to the first rotation axis Ax1 in the X direction. The second motor 32 and the third motor 33 are arranged at positions aligned in the Y direction with the first rotation axis Ax1 interposed therebetween. That is, the first to

third motors

31, 32, 33 are arranged around the first rotation axis Ax1 at 90° intervals. A cover 203 is detachably fixed to the lower surface of the casing 201.

[Configuration of the first power transmission mechanism PT1]
FIG. 5 is a sectional view of an essential part of the industrial robot 1. As shown in this figure, the first power transmission mechanism PT1 rotates the output shaft 31a of the first motor 31 and the first speed reducer 40 interposed between the base portion 20 and the robot arm 22. The first transmission mechanism 46 for transmitting to the first reduction gear 40.

The first speed reducer 40 includes a speed reducer body 42 including a wave gear speed reducing mechanism, and a casing 44 including a rigid structure in which the speed reducer body 42 is incorporated, and extends along the first rotation axis Ax1. It has a substantially annular structure penetrating therethrough.

The casing 44 includes a ceiling-shaped cylindrical upper casing 45a having a peripheral wall portion and a bottomed cylindrical lower casing 45b having a peripheral wall portion, and a labyrinth-shaped gap 44a is formed between the peripheral wall portions. As described above, the upper and

lower casings

45a and 45b have a hollow structure in which they are arranged to face each other. The upper casing 45a is fixed to the lower surface 232 of the later-described casing 231 of the first arm portion 23, and the lower casing 45b is fixed to the upper surface of the casing 201 of the base portion 20.

The speed reducer main body 42 is a well-known wave gear speed reducing mechanism, and is incorporated inside the casing 44. The speed reducer main body 42 includes a wave generator 43a, a circular spline 43b, a flex spline 43c, and a bearing 43d that connects the circular spline 43b and the flex spline 43c in a relatively rotatable state.

The wave generator 43a has a structure in which upper and

lower casings

45a and 45b are rotatably held via bearings 43e, and bearings (not shown) are fitted onto the outer circumference of an elliptical cam. The circular spline 43b is an annular rigid body having internal teeth, is arranged radially outside the wave generator 43a, and is fixed to the lower casing 45b. The flex spline 43c is a thin-walled metal elastic body having external teeth that mesh with the internal teeth of the circular spline 43b, is disposed between the wave generator 43a and the circular spline 43b, and is fixed to the upper casing 45a. ing.

The wave generator 43a is an input unit for the rotational force of the first motor 31, and the upper casing 45a to which the flex spline 43c is fixed is an output unit for the rotational force after deceleration. That is, the first speed reducer 40 decelerates the rotational speed of the rotational driving force input to the wave generator 43a (input unit) and outputs it from the upper casing 45a (output unit).

The first transmission mechanism 46 is a belt transmission mechanism. That is, the first transmission mechanism 46 includes a pulley 47a fixed to the output shaft 31a of the first motor 31, a pulley 47b fixed to the wave generator 43a of the first speed reducer 40, and these

pulleys

47a and 47b. And a transmission belt 48 that is stretched around.

With the configuration of the first power transmission mechanism PT1 as described above, the rotation of the output shaft 31a of the first motor 31 is transmitted to the input portion (wave generator 43a) of the first speed reducer 40 and is rotated by the first speed reducer 40. The speed is reduced and transmitted to the first arm portion 23. As a result, the first arm portion 23 rotates (turns) around the first rotation axis Ax1 at a predetermined rotation speed with respect to the base portion 20.

[Configuration of Second Power Transmission Mechanism PT2]
As shown in FIG. 2, the second power transmission mechanism PT2 includes a second reduction gear 50 provided between the first arm portion 23 and the second arm portion 24, and the base portion 20 to the first arm portion. The rotation of the first transmission shaft 56 extending through the inner side of the first reduction gear 40 over 23 and the rotation of the output shaft 32a (not shown) of the second motor 32 is performed by the first transmission shaft 56 in the base portion 20. And a second transmission mechanism 57 that transmits the rotation of the first transmission shaft 56 to the second speed reducer 50 in the first arm portion 23.

FIG. 6 is an enlarged cross-sectional view of the industrial robot 1. As shown in this figure, the second speed reducer 50 includes a speed reducer main body 52 including a wave gear speed reducing mechanism, and a casing 54 including the speed reducer main body 52 and a rigid structure. Has a substantially annular structure penetrating along the second rotation axis Ax2. The basic structure of the second speed reducer 50 is substantially the same as the structure of the first speed reducer 40 as follows.

The casing 54 includes a ceiling-shaped cylindrical upper casing 55a having a peripheral wall portion and a bottomed cylindrical lower casing 55b having a peripheral wall portion, and a labyrinth-shaped gap 54a is formed between the peripheral wall portions. As described above, the upper and

lower casings

55a and 55b have a hollow structure in which they are arranged to face each other. The upper casing 55a is fixed to the lower surface 232 of the later-described casing 231 of the first arm portion 23, and the lower casing 55b is fixed to the upper surface 243 of the later-described casing 241 of the second arm portion 24.

The speed reducer main body 52 includes a wave generator 53a rotatably held in upper and

lower casings

55a and 55b via bearings 53e, and a circular spline fixed to a lower casing 55b arranged radially outside the wave generator 53a. 53b, a flex spline 53c disposed between the wave generator 53a and the circular spline 53b and fixed to the upper casing 55a, and the circular spline 53b and the flex spline 53c are connected in a relatively rotatable state. And a bearing 53d that operates.

The wave generator 53a is an input unit of the rotational force of the second motor 32, and the upper casing 55a to which the flex spline 53c is fixed is an output unit of the rotational force after deceleration. That is, the second speed reducer 50 decelerates the rotational speed of the rotational driving force input to the wave generator 53a (input unit) and causes the upper casing 55a (output unit) to output the rotational speed. In addition, in the second reduction gear 50, since the upper casing 45a is fixed to the first arm portion 23, the lower casing 45b to which the circular spline 53b is fixed is relatively rotated, so that the rotational force is generated by the second arm portion 24. Be transmitted to.

The second transmission mechanism 57 is a belt transmission mechanism. That is, as shown in FIGS. 3, 5, and 6, the second transmission mechanism 57 includes a pulley 58 a fixed to the output shaft 32 a of the second motor 32 and a lower end portion of the first transmission shaft 56 in the base portion 20. A pulley 58b fixed to the pulley 58b and a transmission belt 59 wound around the

pulleys

58a and 58b. Further, the second transmission mechanism 57 includes a pulley 61 a fixed to the upper end of the first transmission shaft 56 in the first arm portion 23, a pulley 61 b fixed to the wave generator 53 a of the second reduction gear 50, The transmission belt 62 is stretched around the

pulleys

61a and 61b.

The first transmission shaft 56 is a hollow shaft and extends in the Z direction through the first speed reducer 40 of the first power transmission mechanism PT1 and the pulley 47b of the first transmission mechanism 46. The first transmission shaft 56 is held by the upper casing 45a of the first reduction gear 40 and the pulley 47b of the first transmission mechanism 46 in a relatively rotatable state via

bearings

64a and 64b (see FIG. 8). More specifically, a bearing 64a is arranged between the upper casing 45a and the first transmission shaft 56, and a bearing 64b is arranged between the pulley 47b and the first transmission shaft 56. The transmission shaft 56 is secured to the inner rings of the

bearings

64a and 64b on the upper and lower sides of the

bearings

64a and 64b. It should be noted that the pulley 47b is fixed to the wave generator 43a of the first speed reducer 40, and therefore, the first transmission shaft 56 can be said to be held by the first speed reducer 40 such that relative rotation is possible.

With such a configuration of the second power transmission mechanism PT2, the rotation of the output shaft 32a of the second motor 32 is transmitted to the input portion (wave generator 53a) of the second speed reducer 50 through the first arm portion 23, and The rotation speed is reduced by the two reduction gears 50 and transmitted to the second arm portion 24. As a result, the second arm portion 24 rotates (turns) around the second rotation axis Ax2 at a predetermined rotation speed with respect to the first arm portion 23.

[Configuration of Third Power Transmission Mechanism PT3]
As shown in FIG. 2, the third power transmission mechanism PT3 is coaxial with the third reduction gear 70 provided between the second arm portion 24 and the tool mounting portion 25 and the first transmission shaft 56. A second transmission shaft 76 that is disposed and extends through the inside of the first speed reducer 40 from the base portion 20 to the first arm portion 23, and from the first arm portion 23 to the second arm portion 24. The rotation of the third transmission shaft 77 extending through the inside of the second reduction gear 50 and the output shaft 33a (not shown) of the third motor 33 is transmitted to the second transmission shaft 76 in the base portion 20. Then, the rotation of the second transmission shaft 76 is transmitted to the third transmission shaft 77 in the first arm portion 23, and the rotation of the third transmission shaft 77 is transmitted to the third reduction gear 70 in the second arm portion. And a third transmission mechanism 78.

As shown in FIGS. 5 and 6, the third speed reducer 70 includes a speed reducer main body 72 including a wave gear speed reducing mechanism, and a casing 74 including the reducer main body 72 and including a rigid structure. Including, the whole has a substantially annular structure penetrating along the third rotation axis Ax3. The basic structure of the third speed reducer 70 is common to the structure of the first and

second speed reducers

40 and 50 as follows.

The casing 74 includes a ceiling-shaped cylindrical upper casing 75a having a peripheral wall portion and a bottomed cylindrical lower casing 75b having a peripheral wall portion, and a labyrinth-shaped gap 74a is formed between the peripheral wall portions. As described above, the upper and

lower casings

75a and 75b have a hollow structure in which they are arranged to face each other. The upper casing 75a is fixed to the lower surface 242 of the later-described casing 241 of the second arm portion 24, and the lower casing 75b is fixed to the upper portion of the tool mounting portion 25.

The speed reducer main body 72 includes a wave generator 73a rotatably held in upper and

lower casings

75a and 75b via bearings 73e, and a circular spline fixed to a lower casing 75b arranged radially outside the wave generator 73a. 73b, a flex spline 73c arranged between the wave generator 73a and the circular spline 73b and fixed to the upper casing 75a, and the circular spline 73b and the flex spline 73c are connected in a relatively rotatable state. And a bearing 73d for

The wave generator 73a is an input unit for the rotational force of the third motor 33, and the upper casing 75a to which the flex spline 73c is fixed is an output unit for the rotational force after deceleration. That is, the third speed reducer 70 decelerates the rotational speed of the rotational driving force input to the wave generator 73a (input unit) and outputs it from the wave generator 73a (output unit). In the third reducer 70, since the upper casing 75a is fixed to the second arm portion 24, the lower casing 75b to which the circular spline 73b is fixed is relatively rotated, so that the rotational force is applied to the tool mounting portion 25. Be transmitted to.

The third transmission mechanism 78 is a belt transmission mechanism. That is, as shown in FIGS. 3, 5 and 6, the third transmission mechanism 78 includes a pulley 79 a fixed to the output shaft 33 a of the third motor 33 and a lower end portion of the second transmission shaft 76 in the base portion 20. A pulley 79b fixed to the pulley 79b and a transmission belt 80 wound around the

pulleys

79a and 79b. Further, the third transmission mechanism 78 includes a pulley 82a fixed to the upper end of the second transmission shaft 76, a pulley 82b fixed to the upper end of the third transmission shaft 77, and these pulleys in the first arm portion 23. 82a, 82b and a transmission belt 83 that is stretched around. Further, the third transmission mechanism 78 includes a pulley 84 a fixed to the lower end of the third transmission shaft 77 in the second arm portion 24, a pulley 84 b fixed to the wave generator 73 a of the third reduction gear 70, The transmission belt 85 is stretched around the

pulleys

84a and 84b.

The second transmission shaft 76 is a hollow shaft having an outer diameter smaller than the inner diameter of the first transmission shaft 56, and penetrates the inside of the first transmission shaft 56 to extend in the Z direction. The second transmission shaft 76 and the first transmission shaft 56 are arranged concentrically around the first rotation axis Ax1.

The second transmission shaft 76 is held on the first transmission shaft 56 via

bearings

86a and 86b (see FIG. 8) so as to be capable of relative rotation. More specifically,

bearings

86a and 86b are respectively arranged between the first transmission shaft 56 and the second transmission shaft 76 at both ends of the first transmission shaft 56, and the second transmission shaft 76 is provided by a retaining member such as a C ring. On the upper and lower sides of the

bearings

86a and 86b, respectively, are prevented from coming off from the inner rings of the

bearings

86a and 84b.

The third transmission shaft 77 is a hollow shaft and extends in the Z direction through the pulley 61b of the third transmission mechanism 78 of the second power transmission mechanism PT2 and the second reduction gear 50. The third transmission shaft 77 is held by the pulley 61b of the third transmission mechanism 78 and the lower casing 55b of the second speed reducer 50 via

bearings

88a, 88b (see FIG. 6) in a relatively rotatable state. Specifically, a bearing 88a is arranged between the pulley 61b and the third transmission shaft 77, and a bearing 88b is arranged between the lower casing 55b and the third transmission shaft 77, respectively. The transmission shaft 77 is secured to the inner rings of the

bearings

88a and 88b at the upper and lower sides of the

bearings

88a and 88b. It should be noted that the pulley 61b is fixed to the wave generator 53a of the second speed reducer 50, and therefore, it can be said that the third transmission shaft 77 is held by the second speed reducer 50 so as to be capable of relative rotation.

With such a configuration of the third power transmission mechanism PT3, the rotation of the output shaft 33a of the third motor 33 is changed by the input portion (wave generator 73a) of the third reduction gear 70 through the first arm portion 23 and the second arm portion 24. Is transmitted to the tool mounting portion 25 while the rotational speed is reduced by the third reducer 70. As a result, the tool mounting portion 25 rotates about the third rotation axis Ax3 with respect to the second arm portion 24 at a predetermined rotation speed.

In addition, inside the second transmission shaft 76 of the third power transmission mechanism PT3, a first hollow shaft that penetrates the second transmission shaft 76 and extends from the base portion 20 to the first arm portion 23 is formed. One wiring protection shaft 90 is arranged. Further, inside the third transmission shaft 77, a second wiring protection shaft 94, which is a hollow shaft, extends through the third transmission shaft 77 and extends from the first arm portion 23 to the second arm portion 24. Are arranged. The first wiring protection shaft 90, the second transmission shaft 76, and the first transmission shaft 56 are hollow shafts (cylindrical bodies) each having a circular cross section, and the first wiring protection shaft 90, the second transmission shaft 76, and the first transmission shaft. The shafts 56 are arranged concentrically around the first rotation axis Ax1 in this order from the inside. Further, the second wiring protection shaft 94 and the third transmission shaft 77 are both hollow shafts (cylindrical bodies) having a circular cross section, and the second wiring protection shaft 94 and the third transmission shaft 77 have the second rotation axis Ax2. It is arranged from the inside in this order in a concentric circle with the center.

The first and second

wiring protection shafts

90 and 94 protect electric wires and electric wires such as air piping arranged in the SCARA robot 2 as described later.

The first wiring protection shaft 90 is rotatably supported by a coupling member 91 fixed to the pulley 79b of the third power transmission mechanism PT3 via a bearing 92, and also has a C ring or the like with respect to the second transmission shaft 76. It is prevented by the retaining member. The second wiring protection shaft 94 is rotatably supported by a connecting member 95 fixed to the pulley 84a of the third power transmission mechanism PT3 via a bearing 96, and is C relative to the second transmission shaft 76. It is retained by a retaining member such as a ring.

The upper end of the first wiring protection shaft 90 is provided with a notch cut out in a semicircular shape in plan view. The upper end of the first wiring protection shaft 90 is fitted into a semicircular recess in plan view formed on the lower surface of the cover 234a of the casing 231 of the first arm 23. As a result, the first wiring protection shaft 90 rotates together with the first arm portion 23 with respect to the first transmission shaft 56 and the second transmission shaft 76.

Similarly, the upper end of the second wiring protection shaft 94 is also provided with a notch cut out in a semicircular shape in plan view. An upper end portion of the second wiring protection shaft 94 is fitted into a semicircular recess in plan view formed on the lower surface of the cover 234b of the casing 231 of the first arm portion 23. As a result, the second wiring protection shaft 94 rotates together with the first arm portion 23 with respect to the third transmission shaft 77. The cutout portions of the first and second wiring protection shafts 90 face each other in the longitudinal direction of the first arm portion 23.

[Structures of the first arm portion 23 and the second arm portion 24]
The first arm portion 23 has a casing 231 formed of a hollow box-shaped structure that extends in the horizontal direction (direction orthogonal to the Z direction) and has a rectangular rigidity in a side view. The first reduction gear 40 is fixed to a base end portion (right end portion in FIG. 2) of the casing 231. Specifically, the first reduction gear 40 is fixed to the casing 231 by fastening the upper casing 45a of the first reduction gear 40 to the lower surface 232 of the casing 231 with a bolt. The lower surface 232 of the casing 231 has an opening 232a opened at the center of the region where the first speed reducer 40 is fixed, and the first power transmission shaft 56 and the third power transmission of the second power transmission mechanism PT2. The second transmission shaft 76 of the mechanism PT3 is inserted into the casing 231 through the opening 232a together with the pulley 61a and the pulley 82a.

On the other hand, the second reduction gear 50 is fixed to the tip portion (the left end portion in FIG. 2) of the casing 231. Specifically, the upper casing 55a of the second reduction gear 50 is fastened to the lower surface 232 of the casing 231 with a bolt, so that the second reduction gear 50 is fixed to the casing 231. The lower surface 232 of the casing 231 has an opening 232b at the center of the area where the second speed reducer 50 is fixed, and the third transmission shaft 77 of the third power transmission mechanism PT3 is connected to the pulley 82b and the pulley 61b. At the same time, it is inserted into the casing 231 through the opening 232b. In the casing 231, the transmission belt 62 is wound around the pulley 61a and the pulley 61b, and the transmission belt 83 is wound around the pulley 82a and the pulley 82b.

Note that

openings

233a and 233b are formed in the upper surface 233 of the casing 231 at the base end portion and the tip end portion of the casing 231. The

openings

233a and 233b are closed by

covers

234a and 234b that are detachably fastened to the upper surface 233 with bolts.

The second arm portion 24 has a casing 241 formed of a hollow box-shaped structure having rigidity extending in the horizontal direction (direction orthogonal to the Z direction). The second reduction gear 50 is fixed to the base end portion (the right end portion in FIG. 2) of the casing 241. Specifically, the lower casing 45b of the second reduction gear 50 is fastened to the upper surface 243 of the casing 241 with a bolt, so that the second reduction gear 50 is fixed to the casing 231. The upper surface 243 of the casing 241 has an opening 243a opened at the center of the region where the second speed reducer 50 is fixed, and the third transmission shaft 77 of the third power transmission mechanism PT3 together with the pulley 84a. It is inserted into the casing 241 through the opening 243a.

On the other hand, the third reduction gear 70 is fixed to the tip portion (left end portion in FIG. 2) of the casing 241. Specifically, the upper casing 75a of the third reducer 70 is fixed to the lower surface 242 of the casing 241 with a bolt, so that the third reducer 70 is fixed to the casing 241. An opening 242b is opened in the central portion of the lower surface 242 of the casing 241 where the third speed reducer 70 is fixed, and the pulley 84b of the third power transmission mechanism PT3 is inside the casing 241 through the opening 242b. Has been inserted into. In the casing 241, the transmission belt 85 is stretched around the pulley 84a and the pulley 84b.

An opening 242a is formed on the lower surface 242 of the base end of the casing 241, and an opening 243b is formed on the upper surface 243 of the tip. The opening 242a is closed by a cover 244 that is detachably bolted to the lower surface 242, and the opening 243b is closed by a cover 245 that is detachably bolted to the upper surface 243.

[Wiring structure of SCARA robot 2]
Inside the SCARA robot 2, electric wires for driving the first to third motors 31 to 33, electric wires for driving the tool mounted on the tool mounting portion 25, and/or a flexible pipe (tube). ) Is laid out. The pipe is used for supplying and discharging compressed air, for example.

9 to 11 show a wiring structure in the SCARA robot 2, and mainly show a wiring structure of electric wires and/or pipes for driving the tool.

Electric wires and/or pipes (hereinafter, referred to as electric wires 100) for driving the tool are introduced into the casing 201 from the upper portion of the base portion 20 together with the electric wires for driving the first to third motors 31 to 33. Has been done.

The electric wires 100 are inserted into the inside from the lower end portion of the first wiring protection shaft 90, and are introduced into the casing 231 of the first arm portion 23 through the first wiring protection shaft 90. The electric wires 100 are arranged in the casing 231 along the longitudinal direction from the base end portion of the first arm portion 23 toward the tip end portion thereof, and are inserted into the inside thereof from the upper end portion of the second wiring protection shaft 94. The second wiring protection shaft 94 is introduced into the casing 241 of the second arm portion 24.

A partition plate 236 for partitioning the second and

third transmission mechanisms

57, 78 and the space above them is provided inside the casing 231 of the first arm portion 23. As shown in FIGS. 9 and 11, the electric wires 100 are arranged in a straight line along the upper surface of the partition plate 236 without any slack, and are fixed to the partition plate 236 by a wire fixing member 237 such as a binding band. ing. As a result, the electric wires 100 are prevented from moving around in the casing 231 and coming into contact with the second and

third transmission mechanisms

57 and 78 as the first arm portion 23 turns.

In the casing 241 of the second arm portion 24, the electric wires 100 are arranged along the longitudinal direction from the base end portion of the second arm portion 24 toward the tip end portion thereof, and the electric wires 100 of the pulley 84b and the third reducer 70 are provided. It is introduced into the tool mounting portion 25 through the inside. A guide member 246 for guiding the electric wires 100 is provided inside the casing 241, and the electric wires 100 are arranged along the guide member 246. Specifically, the electric wires 100 led out from the lower end of the second wiring protection shaft 94 are arranged so as to pass through the inside of the transmission belt 85 from the lower side to the upper side at a position between the

pulleys

84a and 84b, The pulley 84b is inserted into the third speed reducer 70 from above.

[About unit structure]
In the above-described SCARA robot 2, some of the parts (elements) that form the first to third power transmission mechanisms PT1 to PT3 with the first speed reducer 40 as a main part are assembled in advance to the first speed reducer 40. Thus, the part of the components including the first reduction gear 40 is constructed as one unitized component (referred to as the first reduction gear unit U1). In addition, the second speed reducer 50 is included by pre-assembling a part of the components forming the second and third power transmission mechanisms PT2 and PT3 with respect to the second speed reducer 50. Some of the parts are constructed as one unitized part (referred to as a second reduction gear unit U2). In addition, a part of the parts that form the third power transmission mechanism PT3 is assembled in advance to the third speed reducer 70, so that the part of the parts including the third speed reducer 70 is a unitized part. (Referred to as a third speed reducer unit U3). When the SCARA robot 2 is assembled or maintained, the speed reducer units U1 to U3 are attached to and detached from the first arm portion 23 and the second arm portion 24, as shown in FIG. ing. In this example, the first reduction gear unit U1 corresponds to the "first assembly" of the present invention, and the second reduction gear unit U2 corresponds to the "second assembly" of the present invention.

The following is a description of the first to third speed reducer units U1 to U3, although there are some points that overlap with the above description.

FIG. 8 is a sectional view showing the first reduction gear unit U1. As shown in FIGS. 7 and 8, the pulley 47b of the first transmission mechanism 46 is fixed to the lower end of the wave generator 43a of the first reduction gear 40. A first transmission shaft 56 is provided so as to pass through the inside of the first speed reducer 40 and the pulley 47b. The first transmission shaft 56 is held in a relatively rotatable state with respect to the upper casing 45a of the first reduction gear 40 and the pulley 47b of the first transmission mechanism 46 via

bearings

64a and 64b, and these

bearings

64a and 64b. The upper and lower sides of the

bearings

64a and 64b are prevented from coming off from the inner rings.

The upper end of the first transmission shaft 56 projects above the upper casing 45a, and the pulley 61a of the second transmission mechanism 57 is fixed to this projecting portion. The lower end of the first transmission shaft 56 projects below the pulley 47b, and the pulley 58b of the second transmission mechanism 57 is fixed to this projecting portion.

The second transmission shaft 76 is arranged inside the first transmission shaft 56. The second transmission shaft 76 is held by the first transmission shaft 56 via the

bearings

86a and 86b so as to be capable of relative rotation. It has been stopped.

The upper end of the second transmission shaft 76 protrudes above the pulley 61a, and the pulley 82a of the third transmission mechanism 78 is fixed to this protruding portion. The lower end of the second transmission shaft 76 projects below the pulley 58b, and the pulley 79b of the third transmission mechanism 78 is fixed to this projecting portion.

Then, the first wiring protection shaft 90 is arranged inside the second transmission shaft 76. The first wiring protection shaft 90 is rotatably supported by a connecting member 91 fixed to the pulley 79b via a bearing 92, and is prevented from coming off from the second transmission shaft 76.

As described above, the first reduction gear unit U1 is different from the first reduction gear 40 in that the first and

second transmission shafts

56 and 76, the first wiring protection shaft 90, and the

pulleys

47b, 58b, 61a, 79b, and 81a. Have a structure assembled in advance. Then, when assembling the SCARA robot 2, as shown in FIG. 7, a portion below the first speed reducer 40, that is, a portion of the

pulleys

47b, 58b, 79b is provided on the upper surface of the casing 201 of the base portion 20. The lower casing 45b of the first speed reducer 40 is fastened to the casing 201 with bolts in this state. As a result, the first reduction gear unit U1 is assembled to the base portion 20. In addition, a portion above the first reduction gear 40, that is, a portion of the

pulleys

61a and 82a is inserted into the opening 232a of the casing 231 of the first arm portion 23, and in this state, the upper casing 45a of the first reduction gear 40 is It is fastened to the casing 231 with bolts. As a result, the first reduction gear unit U1 is assembled to the first arm portion 23.

Although the second reducer unit U2 does not show a sectional view of a single unit, as shown in FIGS. 4 and 7, the second reducer unit 50 has a third transmission shaft 77 and a second wiring protection for the second reducer 50. The shaft 94 and the

pulleys

61b, 82b, 84a have a structure assembled in advance. That is, the pulley 61b of the second transmission mechanism 57 is fixed to the upper end of the wave generator 53a of the second reduction gear 50, and the third transmission shaft 77 is inserted so as to penetrate the inside of the second reduction gear 50 and the pulley 61b. It is provided. The third transmission shaft 77 is held in a relatively rotatable state via bearings with respect to the lower casing 55b of the second speed reducer 50 and the pulley 61b of the second transmission mechanism 57, and the bearings are provided on the upper and lower sides of these bearings. It is locked against the inner ring of.

The upper end of the third transmission shaft 77 protrudes above the pulley 61b, and the pulley 82b of the third transmission mechanism 78 is fixed to this protruding portion. The lower end of the third transmission shaft 77 projects below the lower casing 55b, and the pulley 84a of the third transmission mechanism 78 is fixed to this projecting portion.

The second wiring protection shaft 94 is arranged inside the third transmission shaft 77. The second wiring protection shaft 94 is rotatably supported by a coupling member 95 fixed to the pulley 84b via a bearing 96, and is prevented from coming off from the third transmission shaft 77.

As shown in FIG. 7, at the time of assembling the SCARA robot 2, a portion of the second reduction gear unit U2 above the second reduction gear 50, that is, a portion of the

pulleys

61b and 82b is located in the first arm portion 23. It is inserted into the opening 232b of the casing 231, and in this state, the upper casing 55a of the second reduction gear 50 is fastened to the casing 231 with bolts. As a result, the second reduction gear unit U2 is assembled to the first arm portion 23. Further, a portion below the second reduction gear 50, that is, a portion of the pulley 84a is inserted into the opening 243a of the casing 241 of the second arm portion 24, and in this state, the lower casing 55b of the second reduction gear 50 is the casing. It is fastened to 241 with a bolt. As a result, the second reduction gear unit U2 is assembled to the second arm portion 24.

Although a sectional view of the third speed reducer unit U3 alone is omitted, as shown in FIGS. 6 and 7, the pulley 84b and the tool mounting portion 25 are assembled in advance to the third speed reducer 70, respectively. It has a structured structure. That is, the pulley 84b of the third transmission mechanism 78 is fixed to the upper end of the wave generator 73a of the third reduction gear 70, and the tool mounting portion 25 is fixed to the lower casing 75b of the third reduction gear 70.

Then, when assembling the SCARA robot 2, as shown in FIG. 7, a portion of the third reduction gear unit U3 above the third reduction gear 70, that is, a portion of the pulley 84b is located in the second arm portion 24. It is inserted into the opening 242b of the casing 241, and in this state, the upper casing 75a of the third reduction gear 70 is fastened to the casing 241 with bolts.

[Operational effects of SCARA robot 2]
According to the SCARA robot 2 applied to the industrial robot 1 described above, as described above, the first and

second motors

31 and 32 that drive the first and

second arm portions

23 and 24, and the tool mounting portion. A third motor 33 that drives 25 is all mounted on the base portion 20. Therefore, the weight of the robot arm 22, especially the weight of the second arm portion 24 is reduced, and thus the inertia of the robot arm 22 is effectively reduced. Therefore, the robot arm 22 can be operated at a relatively high speed without using high-output motors as the first and

second motors

31 and 32.

Moreover, according to the SCARA robot 2, the first speed reducer 40 is arranged between the base section 20 and the first arm section 23, and the second speed reducer 50 is connected to the first arm section 23 and the second arm section 24. The third speed reducer 70 is disposed between the second arm portion 24 and the tool mounting portion 25. Therefore, while the first to third motors 32 to 33 are all mounted on the base portion 20, the positional accuracy of the first and

second arm portions

23 and 24 and the tool mounting portion 25 during operation is kept high. be able to. That is, for example, the second speed reducer 50 is directly connected to the second motor 32, the rotational speed of the rotational force generated by the second motor 32 is reduced to a predetermined speed, and then the rotational force is transmitted to the second arm portion 24 by belt transmission. It is also possible to do. However, in this case, it is conceivable that an error occurs in the rotational speed in the process of transmitting the rotational force from the second speed reducer 50 to the second arm portion 24, and the positional accuracy of the second arm portion 24 deteriorates. On the other hand, the first reduction gear 40 is directly fixed to the first arm portion 23, the second reduction gear 50 is directly fixed to the second arm portion 24, and the third reduction gear 70 is directly fixed to the tool mounting portion 25. According to the SCARA robot 2 of the above-described embodiment, the rotational force after deceleration is immediately transmitted to the

arm portions

23, 24 and the tool mounting portion 25, so that the first and

second arm portions

23, 24 and the tool are The mounting portion 25 can be reliably operated at the rotation speed after deceleration. Therefore, it is possible to maintain the positional accuracy of the first and

second arm portions

23, 24 and the tool mounting portion 25 during operation at a higher level.

Further, according to the SCARA robot 2, since no motor is mounted on the second arm portion 24 or the tool mounting portion 25, the tip portion of the robot arm 22 is thinned (thinned in the Z direction) accordingly. can do. Further, the robot arm 22 can be moved in the Z direction by operating the single-axis robot 3. Therefore, according to the SCARA robot 2, it is possible to make the robot arm 22 penetrate into a narrow area, which is difficult for the SCARA robot of the related art to penetrate, thereby expanding the application of the SCARA robot 2. be able to.

Also, in the SCARA robot 2, all the electric wires 100 for the tool mounted on the tool mounting portion 25 are routed inside the SCARA robot 2. Therefore, like the conventional SCARA robot in which the electric wires for the tool are installed in the arch-shaped wiring pipe provided over the base portion and the arm portion, the electric wires (wiring Piping) is not swung around. Therefore, it is advantageous in operating the robot arm 22 at a high speed, and is less likely to be restricted by the surrounding environment in which the SCARA robot 2 is used, so that the application of the SCARA robot 2 can be expanded in this respect as well.

Moreover, since the wires 100 are routed along the first rotation axis Ax1, the second rotation axis Ax2, and the third rotation axis Ax3 in the joint portion of the robot arm 22, as shown in FIG. The wires 100 need not be provided with an extra length (play), and the wires 100 can be routed from the base portion 20 to the tool mounting portion 25 at a distance as short as possible. That is, when the wires 100 are routed at positions deviated from the first rotation axis Ax1, the second rotation axis Ax2, and the third rotation axis Ax3, in order to follow the movement of the robot arm 22 by that amount, It is necessary to provide extra length (play) for the electric wires 100, but the electric wires 100 are routed along the first rotation axis Ax1, the second rotation axis Ax2, and the third rotation axis Ax3. Then there is almost no need for that. Therefore, according to the SCARA robot 2, the total length of the electric wires 100 can be shortened, and it is possible to avoid the inconvenience that the extra length portion of the electric wires 100 is rubbed and damaged by the peripheral member inside the robot arm 22. it can.

Moreover, the electric wires 100 are arranged inside the first

wiring protection shafts

90 and 94 at the positions of the first and second rotation shafts Ax1 and Ax2, and the electric wires 100 of the third transmission mechanism 78 rotating at a relatively high speed. There is no direct contact with the second and

third transmission shafts

76, 77. Therefore, even when the wires 100 are routed along the first and second rotation axes Ax1 and Ax2, the wires 100 do not come into contact with and damage the second and

third transmission shafts

76 and 77. .. As described above, the upper ends of the first and second

wiring protection shafts

90 and 94 are fitted in the recesses of the semicircular shape in plan view formed in the casing 231 (

covers

234a and 234b) of the first arm portion 23. Therefore, the first and second

wiring protection shafts

90 and 94 themselves do not rotate. Therefore, even if the electric wires 100 come into contact with the first and second

wiring protection shafts

90 and 94, they will not be damaged.

Further, in the SCARA robot 2, as described above, some parts including the first speed reducer 40 are constructed as one unitized part (first speed reducer unit U1) and include the second speed reducer 50. Some of the parts are constructed as one unitized part (second speed reducer unit U2), and some of the parts including the third speed reducer 70 are made into one unitized part (third speed reducer unit). It is built as U3). When the SCARA robot 2 is assembled or maintained, the first to third speed reducer units U1 to U3 are attached to and detached from the first arm unit 23 and the second arm unit 24 in units. It has become. Therefore, according to the SCARA robot 2, there is also an advantage that the assembling property and the maintainability are very good. In particular, if the aging work is performed in advance so that the unit can adjust the grease to the speed reducer, it is not necessary to test-run the SCARA robot 2 only for the aging work after the SCARA robot 2 is assembled or after maintenance. It is possible to significantly reduce the total assembly time and maintenance time.

In the wiring structure of the SCARA robot 2 shown in FIG. 9, for example, a connector 110 as shown in FIG. 12 is provided in the middle of the electric wires 100, and the electric wires of the portions corresponding to the units U1 to U3 are provided. It is preferable to be able to separate from the electric wires of the other parts. Specifically, it is preferable to provide the connector 110 at the positions P1 to P5 indicated by the circular frame in FIG. 9 in the electric wires 100. Here, P1 and P2 are positions of both ends of the first wiring protection shaft 90 of the electric wires 100, P3 and P4 are positions of both ends of the second wiring protection shaft 94 of the electric wires 100, and P5. Is the position of the upper part of the pulley 84b. According to this configuration, when the SCARA robot 2 is assembled or maintained, a part of the electric wires 100 can be attached/detached together with the units U1 to U3, so that the SCARA robot 2 can be more easily assembled and maintained. improves.

[Modification]
Although the embodiment of the industrial robot 1 to which the SCARA robot 2 according to the present invention is applied has been described above, the SCARA robot 2 is an example of the preferred embodiment of the articulated robot according to the present invention, and the SCARA robot 2 The specific configuration of the industrial robot 1 including this and the industrial robot 1 can be appropriately changed without departing from the scope of the present invention. For example, the following modes can be adopted.

(1) In the embodiment, the SCARA robot 2 is fixed to the slider 12 of the single-axis robot 3 so that the SCARA robot 2 moves in the Z direction. However, the SCARA robot 2 may be one in which the base portion 20 is directly fixed on the ground surface and used.

(2) The SCARA robot 2 of the embodiment has a configuration in which the second arm portion 24 is located above the first arm portion 23, but the second arm portion 24 is located below the first arm portion 23. It may be located. In this case, the internal/external relationship between the first transmission shaft 56 and the second transmission shaft 76 is reversed from that in the above embodiment, and the upper and lower positions of the second transmission mechanism 57 and the first transmission shaft 56 in the first arm portion 23 are reversed. It may be configured to reverse the relationship.

(3) In the embodiment, the first and second

wiring protection shafts

90 and 94 are cylindrical bodies, but the first wiring protection shaft 90 has the first rotation axis Ax1 in the space where the electric wires 100 are routed. The hollow shaft is not limited to a cylindrical body as long as it can exist. Similarly, the second wiring protection shaft 94 is not limited to a cylindrical body as long as it is a hollow shaft in which the second rotation axis Ax2 can exist in the space where the electric wires 100 are routed, and a cylinder of any other shape. It may be a shape. For example, in the first and second

wiring protection shafts

90 and 94, a cylindrical body having an irregular shape in which only a portion supported by bearings has a cylindrical shape and the other portions have a polygonal cross section, and It may be made of a tubular body partially provided with a notch. In the embodiment, the upper ends of the first and second

wiring protection shafts

90 and 94 are fitted into the semicircular recesses in plan view formed in the casing 231 (

covers

234a and 234b) of the first arm 23. By being combined, the first arm portion 23 is non-rotatably connected to the first arm portion 23, but the shape of the connecting portion (the shape of the recess) is not limited to a semicircle, and may be a polygon. Good. Further, the connection structure of the first and second

wiring protection shafts

90 and 94 to the first arm portion 23 is such that the first and second

wiring protection shafts

90 and 94 are non-rotatably connected to the first arm portion 23. If possible, the structure is not limited to the structure in which the upper portions of the first and second

wiring protection shafts

90 and 94 are fitted in the recesses as in the embodiment, and other structures may be used.

(4) In the embodiment, the electric wires 100 are arranged inside the SCARA robot 2, but the electric wires 100 may be provided outside the SCARA robot 2 if necessary. In this case, the first and second

wiring protection shafts

90 and 94 can be omitted. When the first and second

wiring protection shafts

90 and 94 are omitted, the second transmission shaft 76 and the third transmission shaft 77 do not have to be hollow shafts and may be solid shafts.

(5) In the embodiment, the first to

third transmission mechanisms

46, 57, 78 are belt transmission mechanisms, but any one or all of the first to

third transmission mechanisms

46, 57, 78 are gear-transmitted. It is also possible to employ a mechanism.

(6) In the embodiment, the example in which the present invention is applied to the SCARA robot 2 (horizontal articulated robot) has been described, but the present invention is also applicable to other articulated robots such as a vertical articulated robot.

[Summary of the Invention]
The present invention described above is summarized as follows.

An articulated robot according to one aspect of the present invention includes a base portion, a first arm portion rotatably connected to the base portion about a first rotation axis, and a second arm portion for the first arm portion. A multi-joint robot including a second arm unit rotatably connected about a rotation axis, the first motor including a first motor and a second motor respectively provided on the base, and the first reducer. A first power transmission mechanism that transmits a rotational force generated by a motor to the first arm portion, and a rotational force generated by the second motor including a second speed reducer are transmitted to the first arm portion via the first arm portion. A second power transmission mechanism that transmits to two arm portions, the first reduction gear is arranged between the base portion and the first arm portion, and the second reduction gear is the first arm. And a second arm portion.

According to this articulated robot, the first and second motors that drive the first and second arm parts are all mounted on the base part. Therefore, the weight of the first and second arm portions is reduced, which reduces the inertia of the first and second arm portions. Therefore, it is possible to operate the first and second motors at a relatively high speed without using high-output motors as the first and second motors. Further, since the motor is not mounted on the second arm portion, the tip of the second arm portion can be thinned.

The articulated robot includes a tool mounting portion that is rotatably connected to the second arm portion about a third rotation axis, a third motor provided on the base, and a third reducer. And a third power transmission mechanism that transmits the rotational force generated by the three motors to the tool mounting section via the first arm section and the second arm section. It may be arranged between the second arm portion and the tool mounting portion.

According to this articulated robot, it becomes possible to provide the tool mounting portion on the second arm portion while suppressing the weight increase of the first and second arm portions. Therefore, even in the configuration in which the tool mounting portion is provided in the second arm portion, the first and second arm portions can be operated at a relatively high speed without using high-output motors as the first and second motors. Is possible.

In the multi-joint robot according to each of the above aspects, the first speed reducer has an annular structure in which a central portion penetrates along the first rotation axis, and the first power transmission mechanism outputs the output of the first motor. The second power transmission mechanism includes a first transmission mechanism that transmits the rotation of the shaft to the first reduction gear, and the second power transmission mechanism extends through the inside of the first reduction gear from the base portion to the first arm portion. The rotation of the extending first transmission shaft and the output shaft of the second motor is transmitted to the first transmission shaft at the base portion, and the rotation of the first transmission shaft is transmitted at the first arm portion. And a second transmission mechanism that is transmitted to the second speed reducer.

According to this configuration, a compact configuration is achieved in which the inside of the first reduction gear is used as a transmission path of the rotational force from the second motor to the second arm portion.

In this case, in the one including the tool mounting portion, the third motor, and the third power transmission mechanism, the second reduction gear has an annular structure in which a central portion penetrates along the second rotation axis. The third power transmission mechanism is disposed concentrically with the first transmission shaft and extends through the inside of the first speed reducer from the base portion to the first arm portion. The rotation of the transmission shaft, the third transmission shaft extending through the inside of the second reduction gear from the first arm portion to the second arm portion, and the rotation of the output shaft of the third motor are The second transmission shaft is transmitted to the base portion, the rotation of the second transmission shaft is transmitted to the third transmission shaft of the first arm portion, and the rotation of the third transmission shaft is transmitted to the second arm portion. And a third transmission mechanism that is transmitted to the third speed reducer.

With this configuration, a compact configuration is achieved in which the insides of the first and second speed reducers are used as a transmission path of the rotational force from the third motor to the tool mounting portion.

In this case, the first transmission shaft, the second transmission shaft, and the third transmission shaft are hollow shafts, and the articulated robot includes the first transmission shaft and the second transmission shaft from the base portion. And electric wires arranged so as to reach the second arm via the one arm portion and the inside of the third transmission shaft.

According to this configuration, the wires are arranged along the rotation center (first rotation axis) of the first arm portion, so that the wire length from the base portion to the first arm portion is as short as possible. It becomes possible to do. In the present invention, the electric wires are a concept including electric wires and/or flexible pipes (such as air tubes).

In this case, a hollow first wiring protection shaft that penetrates the insides of the first transmission shaft and the second transmission shaft from the base portion to the first arm portion and surrounds the electric wires is provided. Is preferred.

With this configuration, it is possible to prevent damage to the electric wires due to contact between the electric wires and the first transmission shaft (or the second transmission shaft) that may rotate at a relatively high speed.

The articulated robot includes a hollow second wiring protection shaft that penetrates the inside of the third transmission shaft from the first arm portion to the second arm portion and surrounds the electric wires. Is preferred.

With this configuration, it is possible to prevent damage to the wires due to contact between the wires and the third transmission shaft that may rotate at a relatively high speed.

In the articulated robot of each aspect described above, the first reduction gear, the first transmission shaft, the second transmission shaft, and an element fixed to the first reduction gear in the first transmission mechanism. An element of the second transmission mechanism fixed to the first transmission shaft, and an element of the third transmission mechanism fixed to the second transmission shaft are attached to the base portion and the first arm portion. It is preferable to construct a first assembly that is detachably attached to the main body and that is assembled using the first speed reducer as a main member.

With this configuration, during assembly or maintenance of the articulated robot, the first assembly including the first reduction gear can be integrally attached to and detached from the base portion and the first arm portion. Therefore, it contributes to the improvement of the assembling property and the maintainability of the articulated robot.

In this case, in the case where the first wiring protection shaft is provided, it is preferable that the first wiring protection shaft further constructs the assembly together with the first speed reducer.

With this configuration, it is possible to attach/detach the first wiring protection shaft to/from the base portion and the first arm portion together with the first reduction gear and the like.

In this case, in the case where the electric wires are provided, the electric wires are to separate a portion of the electric wires arranged inside the first transmission shaft and the second transmission shaft from other portions. It is preferable to have a connector capable of

According to this configuration, at the time of assembling or maintaining the articulated robot, it becomes possible to attach/detach a part of the electric wires together with the first assembly including the first speed reducer. Therefore, it further contributes to the improvement of the assembling property and the maintainability of the articulated robot.

In the articulated robot of each aspect described above, the second reduction gear, the third transmission shaft, an element of the second transmission mechanism fixed to the second reduction gear, and the third transmission mechanism. The element fixed to the third transmission shaft is assembled by using the second speed reducer as a main member, which can be integrally attached to and detached from the first arm portion and the second arm portion. Suitably, a second assembly is constructed.

With this configuration, during assembly or maintenance of the articulated robot, the second assembly including the second reduction gear can be integrally attached to and detached from the first arm section and the second arm section. Therefore, it contributes to the improvement of the assembling property and the maintainability of the articulated robot.

In this case, in the case where the second wiring protection shaft is provided, it is preferable that the second wiring protection shaft further constructs the second assembly together with the second speed reducer.

With this configuration, the second wiring protection shaft can be attached to and detached from the first arm portion and the second arm portion together with the second speed reducer.

In this case, as for the electric wires including the electric wires, the electric wires include a connector capable of separating a portion of the electric wires arranged inside the third transmission shaft from other portions. Is preferred.

According to this configuration, at the time of assembling or maintaining the articulated robot, it is possible to attach/detach a part of the electric wires together with the second assembly including the second speed reducer. Therefore, it further contributes to the improvement of the assembling property and the maintainability of the articulated robot.

Claims

A base portion; a first arm portion rotatably connected to the base portion about a first rotation axis; and a second arm portion rotatably connected to the first arm portion about a second rotation axis. An articulated robot having an arm part,
A first motor and a second motor respectively provided on the base;
A first power transmission mechanism including a first speed reducer for transmitting the rotational force generated by the first motor to the first arm portion;
A second power transmission mechanism that includes a second speed reducer and transmits the rotational force generated by the second motor to the second arm portion via the first arm portion,
The first speed reducer is disposed between the base portion and the first arm portion,
The multi-joint robot, wherein the second reduction gear is arranged between the first arm portion and the second arm portion.
The articulated robot according to claim 1,
A tool mounting portion that is rotatably connected to the second arm portion about a third rotation axis;
A third motor provided on the base;
And a third power transmission mechanism that includes a third speed reducer and transmits the rotational force generated by the third motor to the tool mounting portion via the first arm portion and the second arm portion. ,
The multi-joint robot, wherein the third reduction gear is arranged between the second arm portion and the tool mounting portion.
The articulated robot according to claim 1 or 2,
The first reduction gear has an annular structure in which a central portion penetrates along the first rotation axis,
The first power transmission mechanism includes a first transmission mechanism that transmits rotation of an output shaft of the first motor to the first speed reducer,
The second power transmission mechanism is
A first transmission shaft extending through the inside of the first speed reducer from the base portion to the first arm portion;
A second transmission of the rotation of the output shaft of the second motor to the first transmission shaft at the base portion, and the rotation of the first transmission shaft to the second reduction gear at the first arm portion. A multi-joint robot characterized by including a transmission mechanism.
The articulated robot according to claim 3,
The tool mounting portion, the third motor, and the third power transmission mechanism,
The second reduction gear has an annular structure in which a central portion penetrates along the second rotation axis,
The third power transmission mechanism is
A second transmission shaft disposed concentrically with the first transmission shaft and extending through the inside of the first speed reducer from the base portion to the first arm portion;
A third transmission shaft extending through the inside of the second speed reducer from the first arm portion to the second arm portion;
The rotation of the output shaft of the third motor is transmitted to the second transmission shaft at the base portion, and the rotation of the second transmission shaft is transmitted to the third transmission shaft at the first arm portion. A multi-joint robot comprising: a third transmission mechanism that transmits rotation of three transmission shafts to the third speed reducer in the second arm portion.
The articulated robot according to claim 4,
The first transmission shaft, the second transmission shaft and the third transmission shaft are hollow shafts,
The articulated robot reaches the second arm from the base portion via the insides of the first transmission shaft and the second transmission shaft, the one arm portion, and the inside of the third transmission shaft. An articulated robot characterized by comprising electric wires arranged in the.
The articulated robot according to claim 5,
A hollow first wiring protection shaft that penetrates the insides of the first transmission shaft and the second transmission shaft from the base portion to the first arm portion and surrounds the electric wires is provided. And an articulated robot.
The articulated robot according to claim 5 or 6, wherein
An articulated joint, comprising a hollow second wiring protection shaft that penetrates the inside of the third transmission shaft from the first arm portion to the second arm portion and surrounds the electric wires. robot.
The articulated robot according to any one of claims 4 to 7,
The first reduction gear, the first transmission shaft, the second transmission shaft, an element of the first transmission mechanism fixed to the first reduction gear, and the first transmission mechanism of the first transmission mechanism. The element fixed to the transmission shaft and the element fixed to the second transmission shaft of the third transmission mechanism can be integrally attached to and detached from the base portion and the first arm portion. A multi-joint robot, characterized in that a first assembly assembled by using the first speed reducer as a main member is constructed.
The articulated robot according to claim 8,
An articulated robot comprising the first wiring protection shaft, wherein the first wiring protection shaft further constructs the first assembly together with the first speed reducer.
The articulated robot according to claim 8 or 9,
The electric wires include the electric wires, and the electric wires can separate a portion of the electric wires arranged inside the first transmission shaft and the second transmission shaft from other portions. A multi-joint robot characterized by having various connectors.
The articulated robot according to any one of claims 4 to 10,
The second reduction gear, the third transmission shaft, an element of the second transmission mechanism fixed to the second reduction gear, and an element of the third transmission mechanism fixed to the third transmission shaft. Means to construct a second assembly that is detachably attached to the first arm portion and the second arm portion and that is assembled with the second speed reducer as a main member. A multi-joint robot characterized by this.
The articulated robot according to claim 11,
An articulated robot comprising the second wiring protection shaft, wherein the second wiring protection shaft further constructs the second assembly together with the second speed reducer.
The articulated robot according to claim 11 or 12,
The electric wires are provided with a connector capable of separating a portion of the electric wires arranged inside the third transmission shaft from other portions. An articulated robot characterized by the following.