JP2006077980A - Reduction gear mounted on revolute joint part of industrial robot - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem on shortening a service life caused by generation of high heat, of a reduction gear in accompany with high-speed operation of a robot or the like. <P>SOLUTION: In this reduction gear 100 of a revolute joint part of an industrial robot, a first stage reduction mechanism 10 is composed of a spur gear type reduction part, and a second stage reduction mechanism 30 is composed of an eccentric rocking type reduction part, and the output from the eccentric rocking type reduction part is taken out from an internal gear body or a support. This reduction gear is mounted on the revolute joint part of the industrial robot rotated by the output from the eccentric rocking type reduction part, or 20 RPM or more, when input rotational frequency to a first input gear part is 2,000 RPM or more. A reduction ratio of the first stage reduction mechanism is determined to rotate each crank shaft under less than 1,000 RPM when the revolute joint part is rotated by the output from the eccentric rocking type reduction part, of 20 RPM or more. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a reduction gear attached to a joint portion of an industrial robot with reduced heat generation.

2. Description of the Related Art Conventionally, a two-stage speed reducer in which a spur gear is provided at the front stage of an eccentric oscillating speed reducer is known as a joint drive speed reducer for a robot. This speed reducer can avoid the resonance phenomenon of the robot in the precision work area such as welding work by appropriately selecting the reduction ratio of the front stage in relation to the natural frequency of the robot joint drive system and the motor rotation speed. It has an effect. Therefore, the reduction ratio of the front stage of the reduction gear is selected from the relationship between the natural frequency, the motor rotation speed, and the necessary total reduction ratio (see, for example, Patent Document 1). On the other hand, the output speed of the conventional speed reducer has been used at about 0 to 15 RPM. Since the motor rotation speed at that time was about 0 to 1500 RPM, high heat that would cause a problem in practical use was not generated in the speed reducer. Therefore, the reduction ratio of the front spur gear was not selected from the viewpoint of heat generation. There wasn't.
JP-A-62-2586

However, in recent years, with the speeding up of the robot and the like, the output speed of the speed reducer has increased to about 0 to 40 RPM, and the motor speed to be used has increased to about 0 to 6000 RPM. Thus, high heat, which is a practical problem, is generated in the reduction gear in the entire work area, and the problem of shortening the life of the reduction gear has arisen. The present invention aims to solve such a problem.
The main cause of heat generation in the speed reducer is, as a matter of common sense, the portion that causes the sliding contact of the eccentric oscillation type speed reducer, that is, the external gear body that meshes with the internal teeth of the internal gear body and the internal gear body. It is thought that this is caused by the meshing contact with the external teeth of the roller, and is not caused by the rolling contact portion, that is, the rotation condition of the crankshaft engaged with the external gear body through the normal rolling bearing. It was done.
However, the inventor has found that the main cause of the heat generation is caused by the rotation condition of the crankshaft. For example, if it is desired to use the motor rotation speed (input rotation speed to the two-stage reduction gear) as 4000 RPM and the final output rotation speed of the two-stage reduction gear as 35 RPM, the total reduction ratio is about 1/114. If the reduction ratio of the reduction mechanism is 1 / 2.5, the reduction ratio of the subsequent reduction mechanism is 1/46, and the crank rotation speed is 1600 RPM (= 4000 / 2.5), resulting in high heat. It is. That is, grease (or lubricating oil) is scattered by centrifugal force due to the high-speed rotation of the crankshaft, and the grease does not sufficiently reach the engagement portion between the crankshaft and the external gear body or the rolling bearing portion. It was clarified that even in the rolling bearing part, slipping occurred and high heat was generated, and iron in the reducer entered the engaging part and rolling bearing part to promote heat generation. . Moreover, since the above heat generation reduces the viscosity of the lubricant, not only the lubrication performance is deteriorated but also a vicious cycle of further promoting the scattering of the lubricant by the centrifugal force is caused.
The present invention has been made on the basis of such knowledge, and limits the number of rotations of the crankshaft so as to minimize the scattering of grease from the above-mentioned engaging portion and rolling bearing portion. Is a solution.

  The speed reducer attached to the joint portion of the industrial robot according to the first aspect of the invention is a speed reducer including a first speed reduction mechanism and a second speed reduction mechanism, and the first speed reduction mechanism decelerates rotation from the motor. And the second stage reduction mechanism engages with the internal gear body, the external gear body meshing with the internal gear body, and the external gear body. A crankshaft that eccentrically swings the external gear body with respect to the internal gear body, and an eccentric rocker that has a support body that supports the crankshaft and outputs output from the internal gear body or the support body Reduction gear attached to the joint of an industrial robot that rotates the output from the eccentric rocking reduction gear at 20 RPM or higher when the input rotational speed to the first stage reduction gear is 2000 RPM or higher. In the machine, from the eccentric rocking reduction gear As the crankshaft rotates not exceed 1000RPM when rotates the force as above 20 RPM, the reduction ratio of the first stage reduction mechanism is selected.

  The speed reducer attached to the joint portion of the industrial robot of the invention of claim 2 is a speed reducer including a first speed reduction mechanism and a second speed reduction mechanism, and the first speed reduction mechanism decelerates rotation from the motor. And the second stage reduction mechanism engages with the internal gear body, the external gear body meshing with the internal gear body, and the external gear body. A crankshaft that eccentrically swings an external gear body with respect to the internal gear body, and an eccentric rocker that has a support body that supports the crankshaft and outputs output from the internal gear body or the support body When the rotational speed input to the first stage speed reducer is 2000 RPM to 4000 RPM, the output from the eccentric rocking speed reducer is attached to the joint part of an industrial robot that rotates at 20 RPM to 40 RPM. Before the reducer As the crankshaft rotates not exceed 1000RPM when rotates the output from the eccentric oscillating-type speed reducer as 20RPM to 40 RPM, the reduction ratio of the first stage reduction mechanism is selected.

  The speed reducer attached to the joint portion of the industrial robot of the invention of claim 3 is a speed reducer including a first speed reduction mechanism and a second speed reduction mechanism, and the first speed reduction mechanism decelerates rotation from the motor. And the second stage reduction mechanism engages with the internal gear body, the external gear body meshing with the internal gear body, and the external gear body. A crankshaft that eccentrically swings an external gear body with respect to the internal gear body, and an eccentric rocker that has a support body that supports the crankshaft and outputs output from the internal gear body or the support body When the rotational speed input to the first stage speed reducer is 4001 to 6000 RPM, the output from the eccentric oscillating speed reducer is attached to the joint part of an industrial robot that rotates at 20 RPM to 40 RPM. In the decelerator, the eccentricity The output from Doshiki reducer as the crankshaft rotates not exceed 1000RPM when being rotated as 20RPM to 40 RPM, the reduction ratio of the first stage reduction mechanism is selected.

  In the reduction gear attached to the joint portion of the industrial robot according to the fourth aspect of the invention, the reduction ratio of the first stage reduction mechanism is between 1/3 and 1 / 6.5.

  In the reduction gear attached to the joint portion of the industrial robot according to the fifth aspect of the invention, the reduction ratio of the second stage reduction mechanism is between 1/20 and 1/60.

  The reduction gear attached to the joint portion of the industrial robot of the invention of claim 6 has a total reduction ratio, which is a product of the reduction ratio of the first stage reduction mechanism and the reduction ratio of the second stage reduction mechanism, from 1/90 to 1 / Up to 300.

  The speed reduction attached to the joint portion of the industrial robot of the invention of claim 7 is a product of the speed reduction ratio of the first speed reduction mechanism and the speed reduction ratio of the second speed reduction mechanism, and the total speed reduction ratio is from 1/90 to 1/200. Until.

  In the speed reducer attached to the joint portion of the industrial robot according to the eighth aspect of the invention, the total reduction ratio, which is the product of the reduction ratio of the first stage reduction mechanism and the reduction ratio of the second stage reduction mechanism, is 1/150 to 1 / Up to 300.

  The reduction gear attached to the joint portion of the industrial robot according to the ninth aspect of the invention has an output from the eccentric rocking reduction gear of 30 RPM to 40 RPM.

  According to the speed reducer attached to the joint portion of the industrial robot of the present invention, the reduction ratio of the first stage speed reduction mechanism is selected to limit the rotation of the crankshaft of the eccentric oscillation type speed reducer that is the second speed reduction mechanism. Therefore, even when it is attached to the joint part of an industrial robot and used at a higher input rotation speed or output rotation speed to the speed reducer, heat generation is suppressed and a reduction in life is prevented.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is an overall view of the industrial robot 50. The industrial robot 50 includes a J1 axis joint part 51, a J2 axis joint part 52, a J3 axis joint part 53, a J4 axis joint part 54, a J5 axis joint part 55, and a J6 axis joint part 56. Each joint part includes a speed reducer. Is attached. The base end arm 58 (swivel head) is attached to be rotatable on the J1 axis joint portion 51 of the base 59. A first arm 200 to be described later is rotatably attached on the J2 axis joint portion 52 of the proximal arm 58.
FIG. 2 is a diagram showing a cross-sectional structure of the speed reducer attached to the J3 axis joint part 53 of the industrial robot according to the first embodiment of the present invention. FIG. It is the figure which expressed the diagram in the concrete structure. 4 is a cross-sectional view taken along the line IV-IV in FIG. 2, 3, and 4, the speed reducer 100 and the electric motor 1 are attached to a J3 axis joint portion 53 of an industrial robot in which the first arm 200 and the second arm 300 rotate relatively. The speed reducer 100 includes a first stage speed reduction mechanism (front stage side speed reduction mechanism) 10 and a second stage speed reduction mechanism (back stage side speed reduction mechanism) 30 that reduce the rotational speed from the electric motor 1.
The first speed reduction mechanism 10 includes a first input gear portion 3 and a flat gear having three second spur gears 5 that mesh with the first input gear portion 3 and are equally distributed around the first input gear portion 3. It is comprised from the gear-type reduction part. The second-stage reduction mechanism 30 has two external gear bodies having an internal gear body 9 having internal teeth 7 composed of a plurality of pins as internal teeth and external teeth 11 meshing with the internal teeth 7 of the internal gear body 9. 13. Three crankshafts 15 each provided with the second spur gear 5 and engaged with the external gear body 13 to cause the external gear body 13 to swing eccentrically with respect to the internal gear body 9; It is composed of an eccentric oscillating speed reducer having a support 17 that supports the three crankshafts 15.
The case of the electric motor 1 and the internal gear body 9 are attached to the first arm 200 with bolts 40. A support 17 is attached to the second arm 300 with a bolt 40.

The speed reducer 100 has an input rotational speed to the first input gear unit 3 of 2000 RPM or higher (when the rotational speed of the output shaft of the electric motor 1 is 2000 RPM or higher, the output from the eccentric oscillating speed reducer (this embodiment) In this embodiment, the internal gear body 9 is fixed, and the output rotation is taken out from the support body 17.) It is attached to the J3-axis joint 53 of an industrial robot that rotates at 20 RPM or more. The reduction ratio of the first stage reduction mechanism 10 (the first input gear portion 3 and the second spur gear 5 and the rotation speed) is set so that each crankshaft 15 rotates without exceeding 1000 RPM when the output is rotated at 20 RPM or more. Is selected between 1/3 and 1 / 6.5, and the reduction ratio of the second stage reduction mechanism 30 (ratio between the rotational speed of the crankshaft 15 and the output rotational speed of the support 17) is 1. / 20 to 1 It is chosen between 60 and the total reduction ratio which is the product of the reduction ratio and the reduction ratio of the second-stage reduction mechanism 30 of the first stage reduction mechanism 10 and between the 1/90 to 1/300.
As a specific setting, for example, when it is desired to use the motor rotation speed (input rotation speed to the first stage reduction mechanism) as 3000 RPM and the final output rotation speed of the second stage reduction gear as 30 RPM, the total reduction ratio is about 1/100. Yes, if the reduction ratio of the first stage reduction mechanism is 1 / 3.6, the reduction ratio of the second stage reduction mechanism is 1/28, and the crank rotation speed is 833 RPM (= 3000 / 3.6). As a result, heat generation is limited.

FIG. 5 is a diagram schematically showing cross sections taken along arrows VV in FIGS. 2 and 3. In FIG. 5, as indicated by a two-dot chain line W, the tooth portion pitch circle size of the second spur gear 5 is at most half the distance between the rotation centers of the crankshafts 15 (rotation centers are indicated by reference numeral 15). I can only take it. The tooth part pitch circle dimension of the first input gear part 3 is arranged at the center part of the limited tooth part pitch circle dimension of the three second spur gears 5. Therefore, the maximum value of the ratio of the tooth portion pitch circle radius of the second spur gear 5 and the tooth portion pitch circle radius of the first input gear portion 3 is the distance between both ends (P1 and P2) of each crankshaft distance and each crank. It can be obtained from a trigonometric function for the triangle (P1-P2-P3) specified by the connecting center (rotation center of the first input gear portion 3) P3, which is theoretically 6.46 times.
As described above, the spur gear type reduction unit according to the first embodiment of the present invention is provided on each of the three crankshafts that mesh with the first input gear unit 3 and the first input gear unit 3, respectively. The spur gear is composed of three second spur gears 5 equally distributed around the first input gear unit 3. In the spur gear reduction unit, the first input gear unit 3 and the three second spur gears 5 The maximum reduction ratio that can be obtained is 1 / 6.5 even if correction of the tooth profile is attempted. Therefore, the upper limit of the reduction ratio of the first stage reduction mechanism 10 is set to 1 / 6.5.
In order to rotate each crankshaft 15 so as not to exceed 1000 RPM, it is better that the reduction ratio of the first stage reduction mechanism 10 is larger. However, in consideration of a practically preferred lower limit and a limited upper limit, The reduction ratio of the first stage reduction mechanism 10 is selected between 1/3 and 1 / 6.5.
When the input rotation speed to the first input gear unit 3 is set to 2000 RPM or more and the output from the eccentric oscillation type reduction unit is rotated to 20 RPM or more, the reduction ratio of the first stage reduction mechanism 10 in the joint part of the industrial robot and the The total reduction ratio, which is the product of the reduction ratio of the two-stage reduction mechanism 30, is considered to be used between about 1/90 and about 1/300. In this case, the reduction ratio of the second reduction mechanism 30 is If it is selected between 1/20 and 1/60, the total reduction ratio can be satisfied in relation to the reduction ratio of the first stage reduction mechanism 10.

The rolling bearing 21 is provided between the support body 17 and the internal gear body 9 so that they can rotate relatively. The seal member 23 is provided between the support 17 and the internal gear body 9 so that grease and lubricating oil inside the speed reducer do not leak to the outside from between them. The rolling bearing 25 is provided between the crankshaft 15 and the support body 17 so that they can rotate relatively. The rolling bearing 27 is provided between the crankshaft 15 and the external gear body 11 so that they can rotate relatively. The support 17 includes a pair of plate-like portions 28 and a column portion 29 that couples the pair of plate-like portions 28. The pair of plate-like portions 28 are provided with the hollow holes 16. A hollow hole 14 is provided in the external gear body 11.
In the present embodiment, the internal gear body 9 is fixed and the output rotation is taken out from the support body 17, but the support body 17 is fixed and the output rotation is taken out from the internal gear body 9. There may be. Moreover, it can also be attached to each joint part of J1 axis | shaft of an industrial robot, J2 axis | shaft, J4 axis | shaft, J5 axis | shaft, and J6 axis | shaft.
Further, as will be described later with reference to FIG. 8, the first stage reduction mechanism 10 may have a two-stage structure. By adopting a two-stage structure, the reduction ratio of the first stage reduction mechanism 10 can be reduced to a ratio 1/12 larger than 1 / 6.5, and the input rotational speed to the first stage reduction mechanism 10 is higher. It becomes possible to cope even if it becomes.
As described above, since the reduction ratio of the first stage reduction mechanism is selected and the rotation of the crankshaft is limited so as not to exceed 1000 RPM, the rotation speed input to the reduction gear is attached to the joint portion of the industrial robot. Even when the output rotational speed is increased, heat generation from the crankshaft portion is suppressed, and a reduction in life can be prevented.

When the input rotational speed to the first input gear unit 3 is 2000 RPM to 4000 RPM, the rotational speed reduction gear is attached to the joint portion of an industrial robot that rotates the output from the eccentric rocking reduction gear as 20 RPM to 40 RPM. The reduction ratio (first input gear) of the first stage reduction mechanism 10 is set so that each crankshaft 15 does not exceed 1000 RPM when the output from the eccentric rocking reduction gear is rotated at 20 RPM to 40 RPM. The reduction ratio between the portion 3 and the second spur gear 5 is selected between 1/3 and 1 / 6.5, and the reduction ratio of the second stage reduction mechanism 30 (the rotation speed of the crankshaft 15 and the support 17) The ratio of the output rotational speed) is selected between 1/20 and 1/60, and the total reduction ratio, which is the product of the reduction ratio of the first stage reduction mechanism 10 and the reduction ratio of the second stage reduction mechanism 30, is set to 1. / 90 to 1/200.
As a specific setting, for example, when it is desired to use the motor rotation speed (input rotation speed to the first stage reduction mechanism) as 4000 RPM and the final output rotation speed of the second stage reduction gear as 35 RPM, the total reduction ratio is about 1/114. Yes, if the reduction ratio of the first-stage speed mechanism is 1 / 4.5, the reduction ratio of the second-stage reduction mechanism is 1/25, and the crank rotation speed is 889 RPM (= 4000 / 4.5). The heat generation is limited.
When the input rotation speed to the first input gear unit 3 is 2000 RPM to 4000 RPM and the output from the eccentric rocking reduction gear is rotated at 20 RPM to 40 RPM, the reduction ratio of the first stage reduction mechanism 10 in the joint portion of the industrial robot The total reduction ratio that is the product of the reduction ratio of the second stage reduction mechanism 30 is considered to be used between about 1/90 and about 1/200. In this case, the reduction ratio of the second reduction mechanism 30 Is selected between 1/20 and 1/60, the total reduction ratio can be satisfied in relation to the reduction ratio of the first stage reduction mechanism 10. As described above, since the reduction ratio of the first stage reduction mechanism is selected and the rotation of the crankshaft is limited so as not to exceed 1000 RPM, the rotation speed input to the reduction gear is attached to the joint portion of the industrial robot. Even when the output rotational speed is increased, heat generation from the crankshaft portion is suppressed, and a reduction in life can be prevented.

When the input rotation speed to the first input gear unit 3 is 4001 RPM to 6000 RPM, the first input gear unit 3 is attached to the joint portion of the industrial robot that rotates the output from the eccentric rocking reduction gear as 20 RPM to 40 RPM. The reduction ratio (first input gear) of the first stage reduction mechanism 10 is set so that each crankshaft 15 does not exceed 1000 RPM when the output from the eccentric rocking reduction gear is rotated at 20 RPM to 40 RPM. The reduction ratio between the portion 3 and the second spur gear 5 is selected between 1/3 and 1 / 6.5, and the reduction ratio of the second stage reduction mechanism 30 (the rotation speed of the crankshaft 15 and the support 17) The ratio of the output rotational speed) is selected between 1/20 and 1/60, and the total reduction ratio, which is the product of the reduction ratio of the first stage reduction mechanism 10 and the reduction ratio of the second stage reduction mechanism 30, is set to 1. / 150 to 1/300.
As a specific setting, for example, when it is desired to use the motor rotation speed (input rotation speed to the first stage reduction mechanism) as 6000 RPM and the final output rotation speed of the second stage reduction mechanism as 40 RPM, the total reduction ratio is about 1/150. Yes, if the reduction ratio of the first stage reduction mechanism is 1 / 6.3, the reduction ratio of the second stage reduction mechanism is 1/24, and the crank rotation speed is low-speed rotation of 952 RPM (= 6000 / 6.3). Heat generation is limited.
When the input rotation speed to the first input gear unit 3 is 4001 RPM to 6000 RPM and the output from the eccentric rocking type reduction unit is rotated at 20 RPM to 40 RPM, the reduction ratio of the first stage reduction mechanism 10 in the joint part of the industrial robot The total reduction ratio that is the product of the reduction ratio of the second stage reduction mechanism 30 is considered to be used between about 1/150 and about 1/300. In this case, the reduction ratio of the second reduction mechanism 30 Is selected between 1/20 and 1/60, the total reduction ratio can be satisfied in relation to the reduction ratio of the first stage reduction mechanism 10.
As described above, since the reduction ratio of the first stage reduction gear is selected and the rotation of the crankshaft is limited so as not to exceed 1000 RPM, the rotational speed input to the reduction gear is attached to the joint portion of the industrial robot. Even when the output rotational speed is increased, heat generation from the crankshaft portion is suppressed, and a reduction in life can be prevented.

Next, the structure of the drive system of the tip part of the articulated industrial robot of FIG. 1, that is, the J4 to J6 axis joint parts 54, 55 and 56 in front of the second arm 300 will be described with reference to FIG.
Three operations (twisting, swinging, and rotating operations to be described later) of the robot tip are two stages arranged in the three electric motors and the J4 axis joint 54, the J5 axis joint 55, and the J6 axis joint 56. It is driven by a speed reducer.
The rotating shaft arm 311 is rotatable (twisted) with respect to the second arm base 309 by the J4 shaft joint 54. The wrist 313 is attached to the tip of the rotary shaft arm 311 and can be rotated (run-out motion) by the J5 shaft joint portion 55.
The grip portion 315 is attached to the tip of the wrist portion 313 and can be rotated (rotated) by the J6 axis joint portion 56. A gripping device provided in the gripper 315 grips a workpiece (not shown) in a detachable manner. At the tip of the wrist 313, there are six degrees of freedom, and the workpiece can be conveyed and positioned freely. The rotation shafts constituting the six degrees of freedom are each driven by a motor and a two-stage reduction type speed reducer according to an embodiment of the present invention to which the rotation of the motor is input, to reduce the rotational speed of the motor. Is driving precisely.

Three motors 317a, 317b, and 317c are arranged on the second arm base 309, and two-stage reduction type speed reducers 319a, 319b, and 319c are connected to each motor via transmission gears. The rotation of each motor is transmitted to three transmission shafts 323a, 323b, and 323c arranged concentrically through a pair of spur gears 321a, 321b, and 321c. Of these, the rotation of the outermost transmission shaft 323a is transmitted to the rotary shaft arm 311 via the two-stage reduction type reduction gear 319a, and is responsible for the motion of the J4 axis joint. The rotation of the intermediate transmission shaft 323b is transmitted to the two-stage reduction type speed reducer 319b via the transmission bevel gear 325, and on the J5 axis joint that is a rotation axis perpendicular to the J4 axis joint of the wrist 313. It is converted into a rotational motion at. The rotation of the innermost transmission shaft 323c is transmitted to a two-stage reduction type reduction gear 319c attached to the tip of the wrist 313 via a transmission bevel gear 327, a pair of transmission spur gears 329, and a transmission bevel gear 331. The The gripping portion 315 is rotated on the J6 axis with the number of rotations reduced by a two-stage reduction type speed reducer 319c.
In this case, the input rotation speed of each of the two-stage reduction gears 319a, 319b and 319c to the first reduction gear is 4000 RPM to 6000 RPM or 6001 RPM or more, and the output from the eccentric rocking reduction gear is 20 RPM to 60 RPM. Or when rotating at 61 RPM or more, the reduction ratio of the first stage reduction mechanism is reduced to 1/3 to 1 / 6.5, the reduction ratio of the second stage reduction mechanism is set to 1/20 to 1/50, It is preferable that the total reduction ratio is set to 1/90 to 1/300 and the maximum rotation speed of the crankshaft is set to 1000 RPM or less, or 900 RPM or less.

  Next, a description will be given of the optimum configuration of the two-stage reduction gear according to the use / use conditions attached to the six joint portions (J1, A2, J3, J4, J5, J6). .

Industrial robots that perform spot welding work, arc welding work, and assembly work have short movements between works and a short drive time at the maximum number of revolutions. Therefore, during the work, the second stage reduction mechanism on the J1, J2, and J3 axes What is necessary is just to set the reduction ratio of a front stage reduction gear so that the average rotation speed of the crankshaft of this can be set to 1000 RPM or less.
However, in industrial robots that perform painting work and transport work, the electric motor is driven at a high rotational speed for a long time during the work, and a high load is often applied when a workpiece is gripped. In this case, a large load is applied to the crankshaft portion of the rear stage reduction mechanism on the J1, J2, and J3 axes, and heat generation increases. Therefore, it is preferable to suppress the heat generation at the crankshaft portion by setting the maximum rotation speed of the crankshaft to 900 RPM or less. Therefore, in this case, the reduction ratio of the front reduction gear may be set so that the maximum rotation speed of the crankshaft can be set to 900 RPM or less.
That is, for the J1, J2, and J3 axes of industrial robots that perform painting and transporting operations, it is preferable that the maximum rotational speed of the crankshaft of the rear stage reduction mechanism be 900 RPM or less.

In industrial robots that perform spot welding work, arc welding work, and assembly work, low speed operation and high speed quick operation on the J4, J5 and J6 axes are required, and the electric motor is driven at high speed continuously for a long time. Heat generation at the crankshaft portion of the rear stage reduction mechanism becomes significant. Therefore, it is preferable to suppress the heat generation at the crankshaft portion by setting the maximum rotation speed of the crankshaft to 900 RPM or less. Therefore, in this case, the reduction ratio of the front reduction gear may be set so that the maximum rotation speed of the crankshaft can be set to 900 RPM or less.
That is, for the J4, J5, and J6 axes of industrial robots that perform spot welding work, arc welding work, and assembly work, it is preferable to set the maximum rotational speed of the crankshaft of the rear stage reduction mechanism to 900 RPM or less.
Further, since the electric motor can be reduced in size by using the high-speed rotating electric motor, the weight of the second arm portion can be reduced and the burden on the J1, J2, and J3 axes can be reduced.

Next, the speed reducer attached to the J4 axis joint part of the industrial robot according to the second embodiment of the present invention will be described with reference to FIG. This speed reducer has a configuration in which a spur gear speed reduction mechanism is further provided on the final output side of the speed reducer according to the first embodiment. The same parts as those of the structure of the speed reducer according to the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
The reduction gear 100 and the electric motor 1 are attached to a J4 axis joint portion 54 of an industrial robot in which the second arm 300 and the rotation axis arm 311 rotate relatively. The reduction gear 100 and the electric motor 1 are provided on the second arm 300 shifted from the rotation axis of the rotation shaft arm 311. The rotary shaft arm 311 is rotatably supported by the second arm 300 with a bearing 404.
The speed reducer 100 basically includes a first stage reduction mechanism 10 and a second stage reduction mechanism 30 that reduce the rotational speed from the electric motor 1. A spur gear 401 is fixed to the support 17 of the second stage reduction mechanism 30. The spur gear 402 is fixed to the rotary shaft arm 311 and meshes with the spur gear 401. The pitch circle diameter of the tooth portion of the spur gear 402 is larger than the pitch circle diameter of the tooth portion of the spur gear 401, and the rotation of the support body 17 is decelerated to 1 / 1.5 to ¼ so that the rotary shaft arm 311 is rotated. Has been communicated to.
In this embodiment, when the input rotational speed to the first stage speed reducer is 2000 RPM to 6000 RPM or 6001 RPM or higher and the output from the eccentric rocking type speed reducer is rotated at 20 RPM to 60 RPM or 61 RPM or higher, The reduction ratio of the first reduction mechanism 10 is 1/3 to 1 / 6.5, the reduction ratio of the second reduction mechanism is 1/20 to 1/50, and the total reduction ratio is 1/90 to 1/1 /. It is preferable to set it to 300 so that the maximum rotation speed of the crankshaft is 1000 RPM or less, or 900 RPM or less.
The spur gear 402, the second arm 300, and the rotary shaft arm 311 have a hollow center 403, and the hollow 403 can be inserted with wiring, piping, etc. required by an industrial robot. Yes.

Next, the speed reducer attached to the J3 axis joint of the industrial robot according to the third embodiment of the present invention will be described with reference to FIG. This speed reducer employs a two-stage spur gear type speed reducer as the first speed reduction mechanism of the speed reducer according to the first embodiment. The same parts as those of the structure of the speed reducer according to the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
The speed reducer 100 and the electric motor 1 are attached to a J3 axis joint portion 53 of an industrial robot in which the first arm 200 and the second arm 300 rotate relatively. The reducer 100 includes a first stage reduction mechanism 10 and a second stage reduction mechanism 30 that reduce the number of revolutions from the electric motor 1. The first stage reduction mechanism 30 is an intermediate shaft having a spur gear 501 fixedly provided on the output shaft of the electric motor 1, a spur gear 502 fixedly provided on the crankshaft 15, a spur gear 503, and a spur gear 504. 505. Further, by making the first stage reduction mechanism 10 a two-stage structure, the reduction ratio of the first stage reduction mechanism 10 can be reduced to a ratio 1/12 larger than 1 / 6.5. Even if the input rotation speed to 10 becomes higher, it becomes possible to cope.
The crankshaft 15 is rotatably supported by the support 17 by a bearing 506. The spur gear 503 meshes with the spur gear 501, and the spur gear 504 meshes with the spur gear 502.
The pitch circle diameter of the tooth portion of the spur gear 503 is larger than the pitch circle diameter of the tooth portion of the spur gear 501, and the pitch circle diameter of the tooth portion of the spur gear 502 is larger than the pitch circle diameter of the tooth portion of the spur gear 504. It has become. The rotation of the electric motor 1 is reduced to 1/2 to 1/5 and transmitted to the intermediate shaft 505, and the rotation of the intermediate shaft 505 is reduced to 1/2 to 1/5 and transmitted to the crankshaft 15.
In this embodiment, when the input rotational speed to the first stage speed reducer is 4000 RPM to 6000 RPM, or 6001 RPM or higher and the output from the eccentric rocking speed reducer is rotated at 20 RPM to 60 RPM, or 61 RPM or higher, The reduction ratio of the first reduction mechanism 10 is 1/3 to 1/12, the reduction ratio of the second reduction mechanism is 1/20 to 1/50, and the total reduction ratio is 1/90 to 1/500. It is preferable to set the maximum rotation speed of the crankshaft to 1000 RPM or less, or 900 RPM or less.

Next, a reduction gear attached to a J1-axis joint part of an industrial robot according to a fourth embodiment of the present invention will be described with reference to FIG. This speed reducer is a modified form of the speed reducer according to the first embodiment, and transmits the rotational driving force of the electric motor only to one specific crankshaft. The same parts as those of the structure of the speed reducer according to the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
The speed reducer 100 and the electric motor 1 are attached to a J1 axis joint portion of an industrial robot in which a base end arm 58 (a turning head) and a base 59 rotate relatively. The reducer 100 includes a first stage reduction mechanism 10 and a second stage reduction mechanism 30 that reduce the number of revolutions from the electric motor 1. The first speed reduction mechanism 10 includes a spur gear 601 fixedly provided on the output shaft of the electric motor 1 and a spur gear 602 fixedly provided on only one specific crankshaft 15. Accordingly, the rotational driving force of the electric motor 1 is first transmitted to only one specific crankshaft 15 of the second stage reduction mechanism 30. The pitch circle diameter of the tooth portion of the spur gear 602 is larger than the pitch circle diameter of the tooth portion of the spur gear 601. The rotation of the electric motor 1 is reduced to 1/2 to 1/5 and transmitted to one crankshaft 15.
The hollow intermediate gear body 603 meshes with the spur gear 602 and meshes with a spur gear (not shown) different from the spur gear 602 provided on the other two crankshafts (not shown). Accordingly, the rotation transmitted to the intermediate gear body 603 is distributed and transmitted to the other two crankshafts. The intermediate gear body 603 is rotatably supported by the base end arm 58 with a bearing 604. The hollow cylindrical cover 605 is sealed with a bolt 607 on the support 17 of the reducer 100 whose outer periphery is in contact with an oil seal 606 provided on the proximal arm 58 and whose other end rotates with respect to the base 59. And sealed. In the cover 605, wiring, piping, and the like 608 required by the industrial robot are inserted.
In this embodiment, when the input rotational speed to the first stage reduction gear is 2000 RPM to 4000 RPM and the output from the eccentric rocking reduction gear is rotated at 20 RPM to 60 RPM, the reduction ratio of the first stage reduction mechanism 10 Is set to 1/3 to 1 / 6.5, the reduction ratio of the second stage reduction mechanism is set to 1/20 to 1/40, and the total reduction ratio is set to 1/90 to 1/200. It is preferable that the maximum rotational speed of the engine is 1000 RPM or less, or 900 RPM or less.

1 is an overall view of an industrial robot 50. FIG. It is a diagram which shows the cross-section of the reduction gear attached to the joint part of the industrial robot which concerns on the 1st Embodiment of this invention. FIG. 3 is a diagram expressing the diagram of FIG. 2 in a specific structure. FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. 3. It is a diagram which shows roughly each VV arrow cross section of FIG. 2 and FIG. It is a diagram which shows the drive system of the joint parts 54, 55, and 56 of FIG. It is a diagram which shows the cross-section of the reduction gear attached to the joint part of the industrial robot which concerns on the 2nd Embodiment of this invention. It is a diagram which shows the cross-section of the reduction gear attached to the joint part of the industrial robot which concerns on the 3rd Embodiment of this invention. It is sectional drawing of the reduction gear attached to the joint part of the industrial robot which concerns on the 4th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Reducer 10 ... 1st stage reduction mechanism 3 ... 1st input gear part 5 ... 2nd spur gear 30 ... 2nd stage reduction mechanism 9 ... ... Internal gear body 13 ... External gear body 15 ... Crankshaft 17 ... Support body 200 ... First arm 300 ... Second arm

Claims (9)

  A speed reducer including a first speed reduction mechanism and a second speed reduction mechanism, wherein the first speed reduction mechanism decelerates rotation from a motor and transmits the reduced speed to the second speed reduction mechanism. A two-stage reduction mechanism engages with an internal gear body, an external gear body meshing with the internal gear body, and the external gear body to cause the external gear body to perform an eccentric oscillating motion with respect to the internal gear body. An eccentric oscillating speed reducer having a crankshaft and a support body that rotatably supports the crankshaft, and outputting an output from the internal gear body or the support body, When the input rotational speed is 2000 RPM or more, in the reducer attached to the joint portion of the industrial robot that rotates the output from the eccentric oscillating speed reducer at 20 RPM or more, the output from the eccentric oscillating speed reducer is 20 RPM. When the rotation is As link shaft rotates not exceed 1000 RPM, speed reducer attached to the articulated portion of the industrial robot, characterized in that the reduction ratio of the first stage reduction mechanism is selected.   A speed reducer including a first speed reduction mechanism and a second speed reduction mechanism, wherein the first speed reduction mechanism decelerates rotation from a motor and transmits the reduced speed to the second speed reduction mechanism. A two-stage reduction mechanism engages with an internal gear body, an external gear body meshing with the internal gear body, and the external gear body to cause the external gear body to perform an eccentric oscillating motion with respect to the internal gear body. An eccentric oscillating speed reducer having a crankshaft and a support body that rotatably supports the crankshaft, and outputting an output from the internal gear body or the support body, When the input rotational speed is 2000 RPM to 4000 RPM, an output from the eccentric oscillating speed reducer is attached to a joint of an industrial robot that rotates the output from the eccentric oscillating speed reducer at 20 RPM to 40 RPM. 20 RPM to 40 RP The reduction gear attached to the joint portion of the industrial robot is characterized in that the reduction ratio of the first stage reduction mechanism is selected so that the crankshaft rotates without exceeding 1000 RPM when being rotated as .   A speed reducer including a first speed reduction mechanism and a second speed reduction mechanism, wherein the first speed reduction mechanism decelerates rotation from a motor and transmits the reduced speed to the second speed reduction mechanism. A two-stage reduction mechanism engages with an internal gear body, an external gear body meshing with the internal gear body, and the external gear body to cause the external gear body to perform an eccentric oscillating motion with respect to the internal gear body. An eccentric oscillating speed reducer having a crankshaft and a support body that rotatably supports the crankshaft, and outputting an output from the internal gear body or the support body, When the input rotational speed is 4001 to 6000 RPM, the output from the eccentric oscillating speed reducer can be attached to the joint of an industrial robot that rotates the output from the eccentric oscillating speed reducer at 20 RPM to 40 RPM. From 20 RPM to 40 RPM As the crank shaft when it is rotated to rotate not exceed 1000 RPM, speed reducer attached to the articulated portion of the industrial robot, characterized in that the reduction ratio of the first stage reduction mechanism is selected.   The reduction gear attached to the joint part of the industrial robot according to any one of claims 1 to 3, wherein a reduction ratio of the first stage reduction mechanism is between 1/3 and 1 / 6.5.   The reduction gear attached to the joint part of the industrial robot according to claim 4, wherein a reduction ratio of the second stage reduction mechanism is between 1/20 and 1/60.   The total reduction ratio, which is the product of the reduction ratio of the first stage reduction mechanism and the reduction ratio of the second stage reduction mechanism, is between 1/90 and 1/300. A reducer attached to the joint of an industrial robot.   The total reduction ratio, which is the product of the reduction ratio of the first stage reduction mechanism and the reduction ratio of the second stage reduction mechanism, is between 1/90 and 1/200. A reducer attached to the joint of an industrial robot.   The total reduction ratio, which is the product of the reduction ratio of the first stage reduction mechanism and the reduction ratio of the second stage reduction mechanism, is between 1/150 and 1/300. A reducer attached to the joint of an industrial robot.   The speed reducer attached to the joint portion of the industrial robot according to any one of claims 1 to 3, wherein an output from the eccentric rocking type speed reducer is 30 RPM to 40 RPM.

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