JPH07290384A - Industrial robot - Google Patents

Abstract

PURPOSE:To independently adjust the tension of a drive belt and the tension of an earth belt by providing an arm drive section positioning means adjusting the position of the other arm drive section in the longitudinal direction of one arm and a tension exciting means applying force to the earth belt from the direction perpendicular to the belt feed direction. CONSTITUTION:The second arm drive section 2 itself on a rotary shaft is moved via the operation of the screw-like second arm drive section positioning means 41 to change the tension of a drive belt 4 for transmitting the driving force to the second arm. Another tensioner 17 is used to excite the tension of an earth belt 13 for earth regulation. The drive belt 4 and the earth belt 13 can be separately adjusted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an industrial robot, and more particularly, in a full-earth type horizontal articulated robot, an action shaft attached to the tip of the arm and capable of vertical movement and rotation is referred to as the first arm and the Always 1 regardless of 2 arm postures
The present invention relates to an industrial robot that maintains a constant rotation angle according to the command value of.

[0002]

2. Description of the Related Art In a full-earth type robot, a drive source for driving a second arm is fixed to a base without being fixed to either the first arm or the second arm. Attempting to reduce the influence of the movement of the first arm when driving the second arm.

The above-mentioned full-earth type robot generally has an RZ axis (also referred to as an action axis, to which a tool or the like can be attached) which moves vertically in the tip portion of the second arm and rotates itself. This RZ
The drive mechanism for driving the shaft is usually fixed and disposed on the second arm.

Here, in the above-mentioned full-earth type robot, the first arm and the second arm are connected to each other by floating support shafts, and the floating shafts always keep the same angular relationship with the base. In addition, the driving mechanism for the RZ axis is also kept in the same angular relationship with this axis, so that the relationship between the first arm and the second arm in the RZ axis is canceled, and the first arm and the second arm are canceled. Even if the positions of the two arms are moved, the precise control can be easily realized without causing fluctuation during the movement of the RZ axis.

[0005]

However, in this structure, the drive belt for driving the second arm serves as a guide for the grounding position inside the first arm, and this axis is the same as that of the base. The earth belt used as the shaft center angle maintaining means for maintaining the rotation angle of is provided, and it is necessary to adjust the tension in each.

However, unless the tension in the drive system is set to be considerably large, the robot positioning accuracy will be deteriorated. On the other hand, the tension of the earth belt may be small, and the smaller the tension, the better the mechanism. It can be simplified. Therefore, the tension adjusting mechanism for the drive belt and the earth belt must not be uniform.

The present invention is a completely new concept invented in the above background, and an object thereof is to provide an industrial robot in which the tension of the drive belt and the ground belt can be adjusted independently and freely.

[0008]

In the present invention, the above object is preferably achieved by a base and a base supported by the base so as to rotate in a horizontal plane with one longitudinal end as a rotation center. 1 arm, a 2nd arm supported by the other longitudinal end of the 1st arm, a rotation axis set in the vertical direction at the longitudinal end of the 2nd arm, and about the above 1st arm A second arm drive unit for driving the second arm, which is arranged at the center of rotation and is prevented from rotating with respect to the base, and a drive for transmitting a driving force from the second arm drive unit to the second arm. A belt, a shaft core for rotatably supporting the first arm and the second arm, a base fixed pulley provided on the base with the rotation shaft of the first arm as a center, and The earth pulley attached to the shaft core and the base A pulley, an earth belt passed over the earth pulley, a rotary shaft drive means that is rotatably provided on the second arm and rotates the rotary shaft, and a rotation angle of the rotary shaft drive means is the axis. A rotary shaft drive part angle maintaining means for maintaining the same rotation angle as the core, a second arm drive part positioning means for adjusting the position of the second arm drive part in the longitudinal direction of the first arm, and It is achieved by an industrial robot including a tension urging unit that applies a force to the earth belt in a direction perpendicular to the belt feeding direction. In the present invention, preferably, the tension urging means includes a disk and a roller attached to the disk to apply a force to the earth belt. Further, in the present invention, preferably, the roller applies a force to the earth belt by rotating the disk of the tension urging means. In the present invention, preferably the second
The arm driving unit positioning means is a screw screw.

[0009]

According to the above construction, the second arm drive section is positioned in the longitudinal direction of the first arm by the second arm drive section positioning means such as a screw screw so that the tension of the drive belt can be controlled independently. Can be adjusted.

Further, the tension urging means can independently and independently adjust the tension of the earth belt by applying a force to the earth belt in a direction perpendicular to the belt extending direction.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. The examples described below are
Since it is a preferred specific example of the present invention, various technically preferable limitations are attached, but the scope of the present invention is, unless otherwise stated to limit the present invention, in the following description.
It is not limited to these modes.

An embodiment of the industrial robot of the present invention will be described with reference to FIGS. 1 to 3. FIG. 1 shows an axial center angle maintaining means 100 in a preferred embodiment of an industrial robot of the present invention.
And the rotary shaft drive unit angle maintaining means 200 and the like. FIG. 2 shows the working shaft 10 in the second arm, the rotary shaft drive part angle maintaining means 200, and the axial drive part angle maintaining means 300.
Is shown. FIG. 3 shows the first arm 3 and the second arm 11.
The structure of the drive system of FIG.

First, the first arm 3, the second arm 11 and the drive system in the embodiment will be described with reference to FIG.
The first arm drive unit 1 in FIG. 3 includes a motor that drives the first arm 3 and a speed reduction mechanism. The first arm driving unit 1 is fixed to the base B, transmits the rotational force to the drive rotation shaft, and the transmitted driving force moves the entire first arm 3. .

The second arm drive unit 2 is composed of a motor for driving the second arm 11 and a speed reduction mechanism connected to the motor output shaft. The second arm drive unit 2 is fixed to the base B in the rotation direction similarly to the first arm drive unit 1. The decelerated driving force of the motor is transmitted to the driving belt driving pulley 5 to rotate the pulley 5. The first arm driving unit 1 and the second arm driving unit 2 are arranged corresponding to the tip 3b of the first arm 3.

The drive belt 4 is a drive belt drive pulley 5
It is suspended between the second shaft driving pulley 6 and the driving force generated by the second arm driving section 2 is transmitted to the second shaft driving pulley 6. As the drive belt 4, for example, a steel belt or the like is used. The second shaft drive pulley 6 is located at the tip 3a of the first arm 3 and is rotatable, and the inside of the second shaft drive pulley 6 is hollow so as to hold other mechanisms. There is.

The central portion of the second arm 11 is fixed to the second shaft drive pulley 6. A working shaft 10 is attached to the tip 11a of the second arm 11, and the working shaft 10 is also provided on the opposite side 1 of the working shaft 11a.
1b has a Z-axis motor 9 and an R-axis motor 8. The Z-axis motor 9 and the R-axis motor 8 are preferably the second arm 11
Is set on. The working shaft 10 is a so-called tool mounting shaft, and is capable of moving in the vertical direction (Z-axis direction) and rotating in the axial direction (R direction). A tool or the like is detachably attached to the action shaft 10. Z
The shaft motor 9 moves the working shaft 10 in the vertical direction (Z-axis direction).
It is an axial driving means for moving to. Further, the R-axis motor 8 is a rotating shaft driving means for rotating the working shaft 10 in the axial direction (R direction).

Next, the operation of these drive systems will be described with reference to FIG. The force rotated by the first arm driving unit 1 is transmitted to the first arm 3, and the first arm 3 moves to the first arm 3.
The arm drive unit 1 can be rotated about the rotation center.

On the other hand, the second arm drive section 2 is fixed in the same phase as the first arm drive section 1, so that the posture of the second arm 11 does not change even when the first arm 3 rotates. It has become. That is, the drive belt drive pulley 5 is rotated by the second arm drive unit 2, the drive force is transmitted to the second shaft drive pulley 6 by using the drive belt 4 as a transmission means, and the second shaft drive pulley 6 is rotated. To be By this rotation, the second arm 11 fixed or attached to the second shaft drive pulley 6 can be rotated. A mechanism on the second arm 11 (not shown in FIG. 3) drives the R-axis motor 8 to rotate the action shaft 10.
Further, by driving the Z-axis motor 9, the working shaft 10 can move up and down in the Z direction.

Next, the means for regulating the postures of the R-axis motor 8 and the Z-axis motor 9 will be described with reference to FIG. These R-axis motor 8 and Z-axis motor 9 are used for the second arm 1
It is rotatably provided with respect to 1. FIG. 1 shows a shaft center angle maintaining means 100, a rotary shaft drive part angle maintaining means 200, and an axial drive part angle maintaining means 3 in an embodiment of the present invention.
00 is shown in the drawing.

First, the shaft center angle maintaining means 100 will be described. The shaft center angle maintaining means 100 is a means for maintaining the earth receiving shaft 15 as the shaft center at the same rotation angle with respect to the base B in FIG. The base fixing pulley 12, the earth belt 13, and the earth receiving pulley 14 shown in FIG.
Is incorporated in the first arm 3 of the.

The earth receiving shaft 15 is incorporated in the rotating shaft of the second arm 11 supported by the tip 3a of the first arm 3. The other parts are incorporated in the second arm 11. The base fixing pulley 12 is in a fixed positional relationship with the base B of FIG. Then, as shown in the drawing, a concentric opening 12a is formed in the center of the pulley 12.
Are provided so as to surround the first arm driving unit 1 and the like shown in FIG. 3 described above. The earth belt 13 is a timing belt (toothed belt), and is suspended between the base fixed pulley 12 and the earth receiving pulley 14. The earth belt tension urging means 17 has a structure in which a disk 72 and two urging rollers 70 and 71 are arranged on the outer periphery of the disk 72. The two urging rollers 70 and 71 contact the earth belt 13 and are grounded. The belt 13 is urged from the outer periphery in a direction substantially orthogonal to it, most preferably in a right-angled direction.

The earth receiving pulley 14 is a pulley located substantially at the tip 3a of the first arm 3, and the earth receiving shaft 15 is attached to the center of the pulley. Earth bearing 1
Reference numeral 5 is also called a shaft core, and the earth receiving pulley 14 and the earth pulley 16 are attached to the earth receiving pulley 14 so as to rotate integrally with the earth pulley 16.

Next, the rotary shaft drive section angle maintaining means 200 will be described. The rotary shaft drive unit angle maintaining means 200 is
This is a means for maintaining the rotation angle of the R-axis motor 8 which is the rotation shaft driving means at the same rotation angle as the earth receiving shaft 15 which is the above-mentioned shaft core.

The earth pulley 16 is a direction regulating pulley, and a Z-axis direction regulating belt 18 is suspended on the earth pulley 16. The Z-axis direction regulation pulley 19 has the Z-axis motor 9 at the center of rotation. Z-axis direction regulation pulley 19
A Z-axis direction regulation belt 18 is suspended from the ground pulley 16 so that the rotation of the ground pulley 16 is the rotation of the Z-axis direction regulation pulley 19. The Z-axis direction regulation belt 18 is also referred to as a rotation axis direction regulation belt. The R axis direction regulation belt 20 is used for the Z axis direction regulation pulley 1.
It is suspended between 9 and the R-axis direction regulation pulley 21.
The R-axis direction regulation belt 20 is a rotation axis direction regulation belt. At the center of the R-axis direction regulation pulley 21, the R-axis motor 8
Is fixed. The R axis direction regulation pulley 21 is a rotation axis direction regulation pulley.

Next, the axial drive section angle maintaining means 300 will be described. The axial driving section angle maintaining means 300 is
This is a means for maintaining the rotation angle of the Z-axis motor 9 as the axial drive means at the same rotation angle as the earth receiving shaft 15 which is the above-mentioned shaft core. Z-axis direction regulating pulley 1 described above
9 and a Z-axis direction regulation belt 18.

Next, a mechanism for transmitting power from the R-axis motor 8 and the Z-axis motor 9 to the working shaft 10, which is a rotating shaft, will be described with reference to FIG. The mechanism described in FIG. 2 is
All are stored in the second arm 11.

The input shaft of the R-axis speed reducer 22 is connected to the output shaft of the R-axis motor 8. The output shaft of the R-axis motor 8 is attached to the rotating shaft of the R-axis drive pulley 23. Therefore, the R-axis speed reducer 22 reduces the rotation of the R-axis motor 8 at a predetermined ratio and transmits it to the R-axis drive pulley 23.

Based on the rotation of the output shaft of the R-axis motor 8,
The R-axis drive belt 24 suspended by the R-axis drive pulley 23 is moved. The output shaft of the Z-axis motor 9 is directly attached to the rotary shaft of the Z-axis drive pulley 25. The Z-axis drive pulley 25 includes a Z-axis drive belt 2
6 is suspended, and a ball screw nut pulley 29 is suspended on the other side of the Z-axis drive belt 26. The ball screw nut pulley 29 is rotated based on the output of the Z-axis motor 9.

On the other hand, a spline nut pulley 30 is suspended on the other side of the R-axis drive belt 24. As a result, the spline nut pulley 30 is rotated with a predetermined reduction ratio by the rotation of the output shaft of the R-axis motor 8. A ball screw nut 28 is attached to the center of rotation of the ball screw nut pulley 29. The ball screw nut 28 is screwed onto the screw portion of the working shaft 10 and
The action shaft 10 moves up and down in the Z direction by the rotation of the ball screw nut 28 driven by the shaft motor 9.

The center of rotation of the spline nut pulley 30 is provided with a spline engagement portion (not shown), and the action shaft 10 is rotated in the R direction by the rotation of the spline nut pulley 30 driven by the R-axis motor 8. It is designed to be rotated around the center.

Next, the operation of the above configuration will be described. First of FIG. 3 of the industrial robot in the embodiment of the present invention.
Consider a case where the arm 3 moves. Since the base fixing pulley 12 of FIG. 1 is fixed to the base B of FIG. 3,
Due to the movement of the first arm 3, the rotation angle of the ground receiving pulley 14 suspended on the ground belt 13 and the ground receiving shaft 15 attached to the ground receiving pulley 14 does not depend on the posture of the first arm 3. It is immutable. The earth belt tension urging means 17 also called a tensioner
By the action of, the ground pulley 14 and the base fixed pulley 12
Since the earth belt 13 is hung with a proper tension between and, the relationship of the rotation angles of these pulleys is kept constant.

On the other hand, since the direction of the earth pulley 16 attached to the earth receiving shaft 15 is unchanged, Z
The Z-axis direction regulation pulley 19 suspended together with the axial direction regulation belt 18 also faces in a fixed direction regardless of the posture of the first arm 3. Therefore, since the Z-axis motor 9 is fixed to the rotation center of the Z-axis direction regulation pulley 19, the direction of the Z-axis motor 9 in the axis center direction is also the first arm 3.
It faces a certain direction regardless of the posture.

Similarly, the R-axis direction regulating pulley 21 suspended by the R-axis direction regulating belt 20 with respect to the Z-axis direction regulating pulley 19 also faces a certain direction regardless of the posture of the first arm 3. . Therefore, since the R-axis motor 8 is fixed to the R-axis direction regulation pulley 21 at the center of rotation, the R-axis motor 9 also faces a certain direction. Then, the R-axis speed reducer 22 and the R-axis drive pulley 23 in which the drive shaft is attached to the shaft of the R-axis motor 8 in FIG.
Also faces a certain direction regardless of the posture of the first arm 3. Then, through the R-axis drive belt 24, the spline nut pulley 30 has a predetermined rotation angle.
That is, according to this configuration, the direction of the action shaft 10, which is also referred to as the rotation shaft, always faces the same direction regardless of the posture of the first arm 3. Then, by operating the R-axis motor 8, the working shaft 10 is passed through the R-axis speed reducer 22.
It becomes possible to have an arbitrary angle by controlling the angle to a predetermined angle.

On the other hand, the Z-axis drive pulley 25 is also rotated by the rotation of the Z-axis motor 9 fixed coaxially with the Z-axis direction control pulley 19. Through this, the ball screw nut pulley 29 is rotated, and accordingly the ball screw nut 28 is rotated, so that the working shaft 10 screwed into the ball screw nut 28 moves up and down.

Now, consider a case where the first arm 3 moves without driving the R-axis motor 8 and the Z-axis motor 9. Then, since the R-axis motor 8 and the Z-axis motor 9 continue to maintain the predetermined angle, the action shaft 10 eventually does not generate the vertical force and the turning force, so that the predetermined angle is maintained.

When the R-axis motor 8 is rotated,
Since the action shaft 10 is rotated with respect to the ball screw nut 28, either vertical force is applied to the ball screw nut 28. In order to avoid such a problem, it is necessary to move the Z-axis motor 9 in accordance with the rotation of the R-axis motor 8 and consequently control the ball screw nut 28 so as not to receive the force. Such control may be performed so that the ball screw nut pulley 29 is rotated by the same angle with respect to the spline nut pulley 30. Therefore, the calculation is extremely easy.

Next, specific examples of the first arm 3 and the second arm 11, the action shaft 10 and the mechanism for maintaining the postures thereof will be described with reference to FIGS. 4 and 5. FIG. 4 illustrates a specific configuration of the first arm 3 in the embodiment of the present invention. A speed reducing mechanism 48 is connected to the output shaft of the first arm motor 45 of the first arm driving section 1, and the first arm 3 is directly connected to the output shaft of the speed reducing mechanism 48.

Further, a speed reducing mechanism 44 is connected to the output shaft of the second arm motor 43 of the second arm drive unit 2, and the output shaft of the speed reducing mechanism 44 is connected to the drive belt drive pulley 5. . Here, the first arm motor 45 and the speed reducer structure 48 form the first arm drive unit 1 of FIG. Further, the second arm motor 43 and the reduction mechanism 44 are
The second arm drive unit 2 of FIG. 3 is formed. The second arm drive unit 2 is attached to the second arm drive unit holding unit 40 via the second arm drive unit support bearing 42 so as to float with respect to the movement of the first arm 3.

The second arm driving section holding section 40 holds the second arm driving section 2 rotatably, and is provided substantially at the center of rotation of the first arm 3 in order to reduce the moment of inertia of the first arm 3. ing.

A second arm drive portion positioning means 41 including a screw screw is screwed from the longitudinal direction of the first arm 3. This second arm drive section positioning means 41
Is also called a holding tension adjusting screw. By rotating the second arm drive portion positioning means 41, the second arm drive portion 2 is movable with respect to the drive belt 4 in the longitudinal direction of the first arm 3, whereby the tension of the drive belt 4 is adjusted. You can do it.

On the other hand, the earth belt 13 suspended on the base fixed pulley 12 is suspended on the earth receiving pulley 14, and the earth receiving shaft 15 attached to the rotation center of the earth receiving pulley 14 is the earth receiving shaft 15. Is supported by a support bearing 46 at the bottom of the. The second shaft drive pulley support bearing 51 is attached between the first arm 3 and the second shaft drive pulley 6, and is rotatably supported by the first arm 3.

The earth receiving shaft upper part supporting bearing 49 and the earth receiving shaft middle part supporting bearing 50 are attached between the second shaft drive pulley 6 and the earth receiving shaft 15 so as to support the earth receiving shaft 15. . Therefore, the second shaft drive pulley support bearing 51 and the second shaft drive pulley 6
The earth receiving shaft 15 is supported by the first arm 3 through the earth receiving shaft upper part supporting bearing 49 and the earth receiving shaft middle part supporting bearing 50.

As shown in FIG. 3, the second shaft drive pulley 6
An opening is provided at the center of rotation of the ground receiving shaft 1
5 penetrates. The second arm 11 is directly fixed to the upper end of the second shaft drive pulley 6.

Next, a specific example of the mechanism inside the second arm 11 will be described with reference to FIG. As shown in FIG. 1, the ground receiving shaft 15 does not engage with the second arm 11,
The upper end of the earth receiving shaft 15 is attached to the center of rotation of the earth pulley 16. Z-axis motor support bearing 60
Is a bearing that is provided between the housing of the second arm 11 and the Z-axis motor 9 and rotatably supports the Z-axis motor 9. The R-axis motor support bearing 61 is a bearing that is provided between the housing of the second arm 11 and the R-axis motor 8 and rotatably supports the R-axis motor 8.

As described above, the Z-axis direction regulation belt 18 is suspended between the Z-axis direction regulation pulley 19 and the ground pulley 16, and the Z-axis direction regulation pulley and R
The R axial regulation belt 20 is provided between the axial regulation pulley 21 and
Is suspended. And the drive shaft of the Z-axis motor 9 has Z
An axis drive pulley 25 is attached, and an R axis drive pulley 23 is attached to the output shaft of the R axis motor 8 via an R axis reducer 22.

By adopting the above configuration, the mechanism of the first arm 3 and the mechanism of the second arm 11 described above are combined. In addition, in the above mechanism, as shown in FIG.
The base fixing pulley 12 and the ground receiving pulley 14 shown in
The turn ratio must be 1: 1. Further, the earth pulley 1 on which the Z-axis direction regulation belt 18 is suspended.
6 and the Z-axis direction regulation pulley 19, and the Z-axis direction regulation pulley 19 and the R-axis direction regulation pulley 21 on which the R-axis direction regulation belt is suspended also need to have a turning ratio of 1: 1 respectively.

Specifically, the radius of these pulleys is the first
It is advantageous from the viewpoint of accuracy and the like that the arm 3 and the second arm 11 have as large a capacity as possible. In the full-earth type robot, in order to change the tension of the driving belt for transmitting the driving force to the second arm 11, the second arm driving unit 2 itself on the rotating shaft is positioned by the second arm driving unit such as a screw screw. It is moved by operating the means 41. In addition, another tensioner (tension urging means) 17 is used to urge the tension of the earth belt for ground regulation. This allows
The drive belt 4 and the earth belt 13 can be separately adjusted, and the mechanism can be simplified. In the embodiment of the present invention, the Z-axis motor 9 and the R-axis motor 8 attached to the second arm 11 in the full-earth type robot are designed so that the deviation angle is invariable with respect to the rotation of the first arm 3. Therefore, the control of the robot control mechanism does not depend on the angles of the first arm and the second arm, and the action axis 1
The Z axis (vertical direction) and the R axis (rotational direction) regarding 0 can be controlled.

That is, the first arm and the second arm are connected to each other by the floating support shafts, and the floating shafts are always kept in the same angular relationship with the base. The relationship between the (R axis) and the first arm and the second arm is maintained, and the drive mechanism of the RZ axis also cancels the same angular relationship as this axis, and the positions of the first arm and the second arm. Precise control can be easily realized without causing fluctuation during movement even by movement.

The present invention is not limited to the above embodiment. In the present invention, for example, the pulley and the belt are preferably used in the illustrated embodiment, but instead of this, a driving force transmitting means such as a combination of a gear and a chain may be used.

[0050]

As described above, according to the present invention, the tension of the drive belt and the earth belt can be adjusted independently and freely, so that the drive system and the ground maintenance system have an optimum and independent structure. Can be taken, which contributes to cost optimization.

[Brief description of drawings]

FIG. 1 is a diagram showing a shaft center angle maintaining means and a rotary shaft drive part angle maintaining means in a preferred embodiment of an industrial robot of the present invention.

FIG. 2 is a view showing a working shaft in a second arm, a rotation shaft driving unit angle maintaining unit, and an axial direction driving unit angle maintaining unit.

FIG. 3 is a diagram showing a driving portion and the like of a first arm and a second arm.

FIG. 4 is a view showing a mechanism of a first arm and a second arm drive part positioning means (screw screw).

FIG. 5 is a view showing a mechanism of a second arm.

FIG. 6 is a view showing a tension urging means for an earth belt.

[Explanation of symbols]

1 1st arm drive part 2 2nd arm drive part 3 1st arm 4 drive belt 8 R axis motor (rotation axis drive means) 9 Z axis motor (axial direction drive means) 10 working axis (rotation axis) 11 2nd arm 13 earth belt 15 earth receiving shaft (shaft core) 16 earth pulley (direction regulation pulley) 17 earth belt tension urging means 18 Z axis direction regulation belt (rotation axis direction regulation belt) 20 R axis direction regulation belt (rotation axis direction regulation belt) ) 21 R axis direction regulation pulley (rotation axis direction regulation pulley) 41 screw screw (second arm drive section positioning means, holding tension adjusting screw) 71 roller 72 disk 100 axis center angle maintaining means 200 rotation angle drive section angle maintaining means 300 Axial drive unit angle maintaining means

Claims (4)

[Claims] 1. A base, a first arm supported by the base so as to rotate on a horizontal plane with one end in the longitudinal direction as a rotation center, and supported by the other end in the longitudinal direction of the first arm. A second arm, a rotation axis set in the vertical direction at a longitudinal end of the second arm, and arranged about the rotation center of the first arm to prevent rotation with respect to the base. A second arm drive section for driving the second arm, a drive belt for transmitting a drive force from the second arm drive section to the second arm, and the first arm and the second arm being rotatable. A shaft core to be supported, a base fixed pulley provided about the rotation axis of the first arm on the base substantially as a center, an earth pulley attached to the shaft core, the base fixed pulley and the earth pulley With the earth belt passed to A rotary shaft driving unit that is rotatably provided on the second arm and that rotates the rotary shaft; and rotation that maintains the rotary angle of the rotary shaft driving unit at the same rotary angle as the shaft core. Axial drive section angle maintaining means, second arm drive section positioning means for adjusting the position of the second arm drive section in the longitudinal direction of the first arm, and a direction perpendicular to the belt feeding direction to the earth belt. An industrial robot, comprising: a tension urging means for applying a force. 2. The industrial robot according to claim 1, wherein the tension urging means includes a disk and a roller attached to the disk to apply a force to the earth belt. 3. The industrial robot according to claim 2, wherein the roller applies a force to the earth belt by rotating a disk of the tension urging means. 4. The second arm drive section positioning means comprises:
The industrial robot according to claim 1, which is a screw.