JP4219320B2 - Robot swivel structure - Google Patents

Description

The present invention, turning the torso of an industrial robot, turning part structure that definitive in arm function clause, that is about the turning part structure of the robot.

The turning portion structure of a conventional robot, for example, there has been known one as described in Patent Documents 1 and 2. Here, the former is disposed between the fixed part and the rotating part, has a hollow hole in the central part, and has two or more crank pins, and the rotational drive applied to the crank pins. An eccentric differential speed reducer that decelerates the force and transmits it to the rotating part to rotate the rotating part, a drive motor attached to the rotating part, a first external gear fixed to the output shaft of the drive motor, A second external gear that is rotatably supported by the speed reducer while maintaining a coaxial relationship with the hollow hole, and a third external gear that meshes directly with the first external gear, and a third external gear that is disposed axially away from the second external gear. A cylindrical body that has an external gear and rotates by receiving a rotational driving force from the first external gear, and is fixed to each crank pin in a state of being directly meshed with the third external gear, and the rotational driving force of the cylindrical body And a fourth external gear for transmitting the gears to the crank pins. It is intended.

The latter is arranged between the fixed part and the rotating part, has a hollow hole in the center part, and has two or more crank pins, and the rotational driving force applied to the crank pins. An eccentric differential type speed reducer that transmits the rotation to the rotating part and rotates the rotating part, a drive motor attached to the rotating part, a first external gear fixed to the output shaft of the drive motor, and the hollow A cylindrical body having a second external gear and a third external gear that are rotatably supported by the speed reducer while maintaining a coaxial relationship with the hole, and that are disposed apart from each other in the axial direction, and the first external gear and the first external gear A second external gear that meshes directly with both external gears and transmits the rotational driving force of the first external gear to the cylindrical body, and is fixed to each crank pin in direct mesh with the third external gear; 5th outside to transmit the rotational driving force of each to the crank pin And the car, but with a.
JP-A-7-108485 JP-A-7-124883

However, in the robot turning portion structure as the former, since the second external gear becomes large, a large noise is disadvantageously generated during turning. The reason for this is that the distance between the output shaft of the drive motor and the center shaft of the speed reducer must be greater than a certain value for reasons such as avoiding interference between the drive motor and the wiring or piping that passes through the hollow hole. This is because the first external gear fixed to the output shaft of the drive motor must have a small diameter in response to a request for downsizing the entire apparatus, and the second external gear inevitably has a large diameter. In order to reduce the diameter of the second external gear, it has been proposed to interpose a fourth external gear as an idle gear between the first external gear and the second external gear, as in the latter case. In this way, in order to rotate the two crank pins synchronously, the first, second, third and fourth external gears and two fifth external gears corresponding to the two crank pins, a total of six As a result, there is a problem that the structure is complicated and the manufacturing cost is high.

This invention aims at providing a turning portion structure of robots that can effectively reduce the noise at the time of turning yet the structure is simple and inexpensive.

Such objects, in a first, in robot swivel unit structure with a driving motor for transmitting a rotational driving force to the arranged reducer and the reduction gear between the fixed portion and the rotating portion, the reduction The machine has a transmission member and an eccentric differential type speed reducer with a hollow hole formed in the center, and the eccentric differential type speed reducer has a large number of pin teeth on the inner periphery and is fixed to the fixed part. Case, two discoid pinions having outer teeth that are accommodated in the case and mesh with the pin teeth and have fewer teeth than the pin teeth , and disposed in the case. A carrier that is rotatably supported and fixed to the rotating part, and both end portions in the axial direction are rotatably supported by the carrier, and two eccentric crank parts at the center part are formed in a pinion. to be inserted respectively, by the rotation By eccentric rotation of the trunnion, and a plurality of crank pins so as to transmit the rotation decelerated in a carrier, the predetermined front hear dynamic motor from the center of the reduction gear and the output shaft to the rotating portion in a radial direction mounting and distance away, also the transmission member, a first external gear of the first transmission member which is fixed to the output shaft of the drive motor, meshes with the first external gear, of the plurality of crank pins It is fixed to a specific one crank pin, when the rotational driving force from said first external gear is reached Den, a second external gear of the second transmission member to rotate the specific one crank pin, the hollow A first cylindrical gear having an external tooth that is coaxial with the hole and meshes with the second external gear, and that rotates by receiving a rotational driving force from the second external gear; and another crank other than the specific one crankpin Pin to pin A third external gear meshing with the external teeth of the first cylindrical gear, and the third external gear transmits the rotational driving force from the first cylindrical gear to the other crank pin, the robot swivel unit structure which is adapted to rotate the crank pin with a particular one of the crank pins can be achieved. Secondly, in the turning part structure of the robot provided with a speed reducer disposed between the fixed part and the rotating part and a drive motor for transmitting the rotational driving force to the speed reducer, the speed reducer includes a transmission member. An eccentric differential reduction gear having a hollow hole formed in the center, the eccentric differential reduction gear having a plurality of pin teeth on the inner periphery and a case fixed to the fixing portion; Two disk-shaped pinions that are housed in the case, mesh with the pin teeth, and have external teeth with fewer teeth than the pin teeth, and are rotatably supported by the case in a state of being disposed in the case. The carrier fixed to the rotating part and both axial end parts are rotatably supported by the carrier, and two eccentric crank parts at the center part are respectively inserted into through holes formed in the pinion, The pinion is biased by the rotation. A plurality of crank pins configured to transmit the reduced speed rotation to the carrier by rotating, and the drive motor is attached to the rotating portion at a predetermined distance in the radial direction from the center of the speed reducer, The transmission member is fixed to a first transmission member fixed to the output shaft of the drive motor and one specific crank pin among a plurality of crank pins, and rotational driving force is transmitted from the first transmission member. A second transmission member for rotating the specific one crankpin, an intermediate gear provided between crank portions of the specific one crankpin, and an outer gear that is coaxial with the hollow hole and meshes with the intermediate gear. A second cylindrical gear having teeth and rotating in response to a rotational driving force from the intermediate gear; and the second circle provided on a crank pin other than the specific one crank pin. The fourth external gear meshes with the external teeth of the toothed gear, and the fourth external gear transmits the rotational driving force from the second cylindrical gear to the other crankpin, and the other crankpin is set to a specific 1 This can be achieved by the turning structure of the robot which is rotated together with one crankpin.

When rotating the rotating part with respect to the fixed part, the drive motor is operated to rotate the output shaft and the first transmission member integrally. In this case, the second transmission member which is fixed to a specific one crank pin receives the first transmission member or et rotational driving force, rotating the specific crank pin. As a result, the eccentric differential speed reducer decelerates the rotational driving force applied to the specific crank pin, transmits it to the rotating part, and rotates the rotating part. At this time, also the crank pin other than the specific crank pin transmits the rotation driving force from the second transmission member, Ru said crankpin also rotates similarly to the specific crank pin. Here, in order to rotate the crankpin, only the first and second transmission members are required, the structure is simplified, the manufacturing cost is reduced, and noise during turning can be effectively reduced.

  As the first and second transmission members, an external gear or a pulley around which a belt is stretched can be used.

Embodiment 1 of the present invention will be described below with reference to the drawings.
1 and 2, reference numeral 11 denotes a main body (base) of an industrial robot as a fixed portion, and a space 12 in which wiring and piping are accommodated is formed in the main body 11. A swiveling body 13 serving as a rotating portion that rotates around a vertical axis is installed above the main body 11, and a hole 14 that extends vertically is formed on the rotating shaft of the swiveling body 13.

  Reference numeral 17 denotes an eccentric differential type speed reducer disposed between the main body 11 and the swivel body 13. The speed reducer 17 has a substantially cylindrical case 19 fixed to the upper end of the main body 11. On the inner periphery of the case 19, a large number of cylindrical pin teeth 20 are provided in a state where only half are embedded in the central portion in the axial direction. These pin teeth 20 extend in the axial direction and are spaced equidistantly in the circumferential direction. Reference numeral 21 denotes two disk-shaped pinions housed in the case 19, and a large-diameter through hole 22 is formed in the center of these pinions 21. Further, external teeth 23 having a smaller number of teeth than the pin teeth 20 of the case 19 are formed on the outer periphery of the pinions 21, and these external teeth 23 mesh with the pin teeth 20. 26 is a carrier disposed in the case 19, and this carrier 26 is disposed on one side flange 27 disposed on one side (lower side) of the pinion 21 and on the other side (upper side) of the pinion 21 in the axial direction. A plurality of axially extending flanges disposed on and fixed to the revolving body 13 and having a lower end integrally connected to the first flange 27 and an upper end detachably connected to the other flange 28 The connecting rods 29 are loosely fitted into loose fitting holes 30 formed in the pinion 21. Reference numeral 32 denotes a pair of bearings interposed between the one and other flanges 27 and 28 and the case 19, and the carrier 26 is rotatably supported by the case 19 by these bearings 32. Further, seal members 33 are interposed between the one-side and other-side flanges 27 and 28 and both ends of the case 19 in the axial direction. Reference numeral 37 denotes two or more axially extending crankshafts arranged here at equal distances in the circumferential direction, here two crankpins. Each crankpin 37 has one axial end (lower end) on one side via a bearing 38. The other end of the flange 27 is rotatably supported by the other flange 28 via a bearing 39. Each crank pin 37 has two crank portions 40 that are eccentric at the center, and these crank portions 40 are inserted into through holes 41 formed in the pinion 21 with needle bearings 42 interposed therebetween. Yes. Reference numeral 43 denotes a cylindrical body. The cylindrical body 43 has one axial end portion (lower end portion) inserted and fixed in the one-side flange 27, and its axial central portion is loose in the through hole 22. Further, the other axial end portion (upper end portion) is loosely fitted in the hole 14 of the swivel body 13. Reference numeral 44 denotes a seal member interposed between the other axial end of the cylindrical body 43 and the swivel body 13. The case 19, the pinion 21, the carrier 26, the crank pin 37, and the cylindrical body 43 as a whole are arranged so that the rotational driving force applied to the crank pin 37 is decelerated and transmitted to the revolving body 13 so that the revolving body 13 is vertically The speed reducer 17 is configured to rotate around a certain axis, and the speed reducer 17 is provided with the cylindrical body 43 as described above, so that a hollow hole 45 communicating the inside of the revolving body 13 and the space 12 at the center. Is formed. The hollow hole 45 is used for passing cables, pipes, etc. here, such as cables 46.

Reference numeral 50 denotes a drive motor (servo motor) attached to the swivel body 13, and an output shaft 51 of the drive motor 50 is arranged in the radial direction from the center of the hollow hole 45 in order to avoid interference with the cables 46. The predetermined distance is larger than the distance from the center of the hollow hole 45 to the rotating shaft of the crankpin 37. As a result, the crank pin 37 is positioned between the output shaft 51 of the drive motor 50 and the cylindrical body 43. A first external gear 52 as a first transmission member is fixed to the distal end of the output shaft 51, and the other axial end (upper end) protruding from the carrier 26 of one particular crank pin 37a out of the crank pins 37. ) Is fixed with a second external gear 53 as a second transmission member, and the external gear 53 and the external gear 52 are directly meshed with each other. As a result, the rotational driving force of the external gear 52 is directly transmitted to the external gear 53 to first rotate the specific crank pin 37a. If the external gears 52 and 53 are directly meshed with each other in this way, the drive motor 50 can be arranged in a wide range around the crankpin 37a. A cylindrical gear 55 serving as a first cylindrical gear having external teeth coaxially with the hollow hole 45 is disposed in the speed reducer 17, specifically between the external gear 53 and the cylindrical body 43. One end portion (lower end portion) in the axial direction of 55 is rotatably supported by the other flange 28 of the speed reducer 17 via a bearing 56. Note that the other axial end portion (upper end portion) of the cylindrical gear 55 is rotatably supported by the swing body 13 via a bearing 57. The external teeth of the cylindrical gear 55 are directly meshed with the external gear 53. As a result, the cylindrical gear 55 rotates by receiving the rotational driving force from the external gear 53 directly. An external gear 58 as a third external gear that directly meshes with the external teeth of the cylindrical gear 55 is fixed to the other axial end (upper end) protruding from the carrier 26 of the crankpin 37b other than the specific crankpin 37a. The external gear 58 directly receives the rotational driving force from the cylindrical gear 55 to rotate the crank pin 37 b and distributes the rotational torque to the two crank pins 37 .

Next, the operation of the first embodiment of the present invention will be described.
When the swivel body 13 is swung with respect to the main body 11, the drive motor 50 is operated to rotate the output shaft 51 and the external gear 52 integrally. At this time, since the external gear 53 is directly meshed with the external gear 52, the rotational drive force is directly received from the external gear 52, and the specific crank pin 37a is first rotated. As a result, the pinion 21 rotates eccentrically (revolves) at the same rotational speed as the crank pin 37a. At this time, the external teeth 23 of the pinion 21 are smaller in number of teeth than the pin teeth 20 of the case 19 and mesh with the pin teeth 20 of the case 19, and the case 19 is fixed to the main body 11 so that the case 19 cannot rotate. Therefore, the rotational driving force applied to the specific crank pin 37 a is decelerated at a high ratio by the case 19 and the pinion 20, taken out by the carrier 26, and transmitted to the revolving body 13. As a result, the revolving structure 13 rotates at a low speed and a large torque around the vertical axis. At this time, the rotational driving force from the external gear 53 is transmitted to the crank pins 37b other than the specific crank pin 37a via the cylindrical gear 55 and the external gear 58 that are directly meshed with each other. 37b also rotates in the same manner as the specific crank pin 37a. Here, since the external gear 53 fixed to the crankpin 37a is located between the external gear 52 (the output shaft 51 of the drive motor 50) and the cylindrical gear 55, these external gears 52 and 53 and the cylindrical gear Any of the gears 55 can have a small diameter, which can effectively reduce noise during turning. Moreover, in order to rotate the two crank pins 37a and 37b, the four gears of the external gears 52, 53 and 58 and the cylindrical gear 55 may be used. As a result, the structure is simplified and the manufacturing is possible. Cost is also low.

3 and 4 are views showing Embodiment 2 of the present invention. In this embodiment, the pulley 60 is used as the first transmission member fixed to the output shaft 51 of the drive motor 50, and the pulley 61 is also used as the second transmission member fixed to the specific crank pin 37a. the rotational driving force to pass over a timing belt 62 to 60 and 61 are to reach transfer from the pulley 60 to 61. Further, in this embodiment, an intermediate gear 63 is provided between the axial center portion of the specific crank pin 37a, more specifically, between the two crank portions 40, and between the pinion 21 and the intermediate gear 63 and the cylindrical body 43. Both end portions are rotatably supported by the carrier 26 via bearings 64, and a cylindrical gear 65 is provided as a second cylindrical gear having external teeth . Then, by directly meshing the intermediate gear 63 and the external teeth of the cylindrical gear 65 , the rotational driving force of the pulley 61 is transmitted to the cylindrical gear 65 via the specific crank pin 37a and the intermediate gear 63. ing. The external gear of this cylindrical gear 65 is directly meshed with an external gear 66 as a fourth external gear provided at the center in the axial direction of the other crank pin 37b. As a result, the crank pin 37b It rotates at the same rotational speed in the same direction as 37a. Since the intermediate gear 63 is provided at the axial center of the crank pin 37a supported at both ends, noise due to meshing with the cylindrical gear 65 is reduced, and the rotational force of the crank pin 37a is reduced. Since it is merely transmitted to the crankpin 37b via the cylindrical gear 65 and the external gear 66, a narrow width is sufficient. In this embodiment, the pulleys 60 and 61, the intermediate gear 63, the cylindrical gear 65, and the five gears of the external gear 66 may be used to rotate the two crank pins 37a and 37b. As a result, the structure is simple and the production cost is low. Further, as described above, the cylindrical gear 65 is housed in the speed reducer 17, and the seal member 67 is provided between the crank pin 37 and the other flange 28, so that the oil and grease in the speed reducer 17 are sealed. Accordingly, the pulleys 60 and 61 can be used as the first and second transmission members. Other configurations and operations are the same as those in the first embodiment.

This invention can be applied to industrial fields turning portion structure of the robot.

It is front sectional drawing which shows Example 1 of this invention. It is II sectional view taken on the line of FIG. It is front sectional drawing which shows Example 2 of this invention. It is II-II arrow sectional drawing of FIG.

Explanation of symbols

11 ... Fixed part 13 ... Rotating part
17… Eccentric differential reducer 37… Crank pin
37a ... Specific crank pin 45 ... Hollow hole
50 ... Drive motor 51 ... Output shaft
52 ... 1st transmission member 53 ... 2nd transmission member
55 ... Cylindrical gear 58 ... External gear

Claims (2)

In robot swivel unit structure with a driving motor for transmitting a rotational driving force to the arranged reducer and the reduction gear between the fixed portion and the rotating portion, wherein the speed reducer and the transmission member, the hollow in the center An eccentric differential reduction gear having a hole formed therein, the eccentric differential reduction gear having a plurality of pin teeth on an inner periphery, and a case fixed to the fixing portion, and housed in the case Two disk-shaped pinions that mesh with the pin teeth and have fewer external teeth than the pin teeth , and are rotatably supported by the case in a state of being disposed in the case , The fixed carrier and both ends in the axial direction are rotatably supported by the carrier, and two eccentric crank parts at the center part are respectively inserted into through holes formed in the pinion, and the pinion is rotated by the rotation. Eccentric rotation Accordingly, a plurality of crank pins so as to transmit the rotation decelerated in a carrier, before the hear dynamic motor mounting by a predetermined distance away in a radial direction from the center of the reduction gear and the output shaft to the rotary part, The transmission member meshes with the first external gear as a first transmission member fixed to the output shaft of the drive motor, and the specific one crank pin among the plurality of crank pins. is secured to, when the rotational driving force from said first external gear is reached Den, a second external gear of the second transmission member to rotate the specific one crank pin, the hollow hole coaxial with the second A first cylindrical gear having external teeth meshing with the external gear, rotating by receiving a rotational driving force from the second external gear, and fixed to another crank pin other than the specific one crank pin; 1st cylindrical gear The third external gear meshes with the external teeth, and the third external gear transmits the rotational driving force from the first cylindrical gear to another crank pin, and the other crank pin is used as one specific crank pin. robot swivel unit structure characterized in that so as to rotate with. In a swivel structure of a robot provided with a speed reducer disposed between a fixed part and a rotating part and a drive motor for transmitting a rotational driving force to the speed reducer, the speed reducer has a transmission member and a hollow hole in a central part. The eccentric differential type reducer has a large number of pin teeth on the inner periphery, and a case fixed to the fixed portion, and is housed in the case. Two disk-shaped pinions that mesh with the pin teeth and have external teeth that have fewer teeth than the pin teeth, and are rotatably supported by the case in a state of being arranged in the case and fixed to the rotating part And both ends in the axial direction are rotatably supported by the carrier, and two eccentric crank parts at the center part are respectively inserted into through holes formed in the pinion, and the pinion is eccentric by the rotation. Rotate A plurality of crank pins configured to transmit the reduced rotation to the carrier, and the output shaft of the drive motor is attached to the rotating portion at a predetermined distance in the radial direction from the center of the speed reducer. When the transmission member is fixed to the first transmission member fixed to the output shaft of the drive motor and one specific crank pin among the plurality of crank pins, and the rotational driving force is transmitted from the first transmission member A second transmission member for rotating the specific one crank pin, an intermediate gear provided between crank portions of the specific one crank pin, and external teeth that are coaxial with the hollow hole and mesh with the intermediate gear. A second cylindrical gear that rotates in response to a rotational driving force from the intermediate gear, and an external tooth of the second cylindrical gear that is provided on a crank pin other than the one specific crank pin. It is composed of a meshing fourth external gear, and the fourth external gear transmits the rotational driving force from the second cylindrical gear to another crank pin to rotate the other crank pin together with a specific one crank pin. A robot swivel structure characterized by that.

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