Conveying device

Abstract

This invention enables high-speed operation while suppressing an increase in the overall size of the device. [Solution] The conveying device 1 includes a fixed base 10, a swivel body 26, two or more servo motors, a conveying arm 50, and two or more reduction gears 40. The swivel body 26 has a large gear 14 which is an external gear. The reduction gear 40 includes a housing 41 integrated with the fixed base 10, a planetary carrier 42 rotatably supported inside the housing 41, an internal gear 43 provided inside the housing 41, a sun gear 44 connected to the output shaft 32 of the servo motor, a plurality of planetary gears 45 arranged around the sun gear 44 and rotatably supported by the planetary carrier 42, and an output gear that rotates integrally with the planetary carrier 45. The planetary gears 45 mesh with the sun gear 44 and also mesh with the internal gear 43. The output gear has a smaller diameter than the large gear 14 and meshes with the large gear 14 on the outside of the large gear 14.

Description

Technical Field

[0001] The present invention relates to a transfer device that transfers a workpiece using a transfer arm.

Background Art

[0002] Conventionally, in a transfer device that swings a transfer arm, an eccentric swing type reduction gear is often adopted in the drive mechanism for swinging the transfer arm (for example, Patent Document 1). Since such an eccentric swing type reduction gear has a small backlash, when adopted in a transfer device, it has an advantage of excellent position accuracy in the transfer operation.

[0003] In addition, a reduction gear using a planetary gear in a drive mechanism such as a joint of a robot is also known (for example, Patent Document 2).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when an industrial robot equipped with an eccentric swing type reduction gear as in Patent Document 1 is assumed to be used as a transfer device for loading a workpiece from a stacker loaded with a workpiece for press working into a press, or for unloading a workpiece processed by a press from the press to a stacker, or for transferring a workpiece from one press to another press among a plurality of presses, in order to improve production efficiency, it is necessary to reciprocate (swing) the transfer arm at a higher speed within a limited area (space). For this purpose, if the swing speed of the transfer arm is increased, the inside of the reduction gear generates heat and the components expand, resulting in a problem that the high-speed operation is limited.

[0006] Furthermore, the reduction gear described in Patent Document 2 suppresses heat generation even when the reciprocating motion of the transport arm is accelerated. However, in order to increase the output torque of the motor in order to realize high-speed rotational motion using an inexpensive and lightweight motor, it is necessary to increase the reduction ratio by linking multiple gears together. Linking multiple gears together in this case involves increasing the distance from the pivot axis of the transport arm to the center of gravity of the motor. In other words, the moment of inertia of the pivot part of the transport device itself increases. This increase in the moment of inertia limits the increase in acceleration and deceleration of the transport arm that is continuously reciprocating within a limited area, and consequently hinders the realization of continuous high-speed transport.

[0007] Therefore, the present invention provides a conveying device that makes it easier to secure a large reduction ratio for the speed reducer and enables high-speed conveying arm that repeatedly performs oscillating motion. [Means for solving the problem]

[0008] The present invention has been made to solve at least some of the above-mentioned problems and can be realized in the following embodiments or applications.

[0009] [1] One aspect of the conveying device according to the present invention is: Fixed base and A swivel body supported on the aforementioned fixed base via a bearing, The rotating body is fixed to the aforementioned fixed base and rotates relative to the aforementioned fixed base. Two or more servo motors, A transport arm configured to rotate together with the aforementioned swivel body to transport a workpiece, Two or more reduction gears fixed to the aforementioned fixed base and connected to the two or more servo motors, Includes, The aforementioned swivel body has a large gear which is an external gear, The reduction gear comprises a housing integrated with the fixed base, a planetary carrier rotatably supported inside the housing, an internal gear provided inside the housing, a sun gear connected to the output shaft of the servo motor, a plurality of planetary gears arranged around the sun gear and rotatably supported by the planetary carrier, and an output gear that rotates integrally with the planetary carrier. The planetary gear meshes with the sun gear and meshes with the internal gear. The output gear is characterized by having a smaller diameter than the large gear and meshing with the large gear on its outer side.

[0010] According to one embodiment of the conveying device, by using planetary gears instead of an eccentric oscillating type reducer that generates a lot of heat, such as the one in Patent Document 1, the rotation speed of the swivel body and conveying arm can be increased while suppressing heat generation. Furthermore, according to one embodiment of the conveying device, by arranging two or more reducers using planetary gears around a large gear which is an external gear, a high reduction ratio can be easily secured.

[0011] [2] In one embodiment of the conveying device, The two or more servo motors include a first servo motor and a second servo motor. The output gear includes a first output gear rotated by the first servo motor and a second output gear rotated by the second servo motor. The aforementioned large gear rotates around the first axis of rotation, The first output gear may be configured to be located opposite the second output gear across the first rotation axis.

[0012] According to one embodiment of the conveying device, because the gears are located opposite each other with the large gear in between, the stress balance of the large gear at the position where it meshes with the first and second output gears is good, and the lifespan of the gears can be extended.

[0013] [3] In one embodiment of the conveying device, The workpiece may be a metal sheet for press working or a product after press working.

[0014] According to one aspect of the transfer device, even when transferring a metal workpiece, it is possible to increase the transfer speed of the workpiece.

Brief Description of the Drawings

[0015] [Figure 1] It is a perspective view of a plurality of transfer devices and a plurality of press machines according to this embodiment. [Figure 2] It is a perspective view of the transfer device according to this embodiment. [Figure 3] It is a cross-sectional view taken along line A-A of FIG. 2. [Figure 4] It is a cross-sectional view taken along line B-B of FIG. 3. [Figure 5] It is a cross-sectional view taken along line C-C of FIG. 3.

Modes for Carrying Out the Invention

[0016] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. Note that the embodiments described below do not unduly limit the content of the present invention described in the claims. Also, not all of the configurations described below are essential constituent elements of the present invention.

[0017] 1. Outline of the Transfer Device FIG. 1 is a perspective view of a plurality of transfer devices 1 and a plurality of press machines 3 according to this embodiment, and FIG. 2 is a perspective view of the transfer device 1 according to this embodiment. In FIG. 2, the upper part of the press machine 3 is omitted and schematically shown. Also, FIG. 2 is a perspective view of the transfer device 1 seen from the opposite side to FIG. 1.

[0018] As shown in Figures 1 and 2, the conveying device 1 is positioned, for example, adjacent to the press machine 3. Alternatively, as shown in Figure 1, for example, multiple conveying devices 1 may be arranged in a production line where multiple press machines 1 are lined up and processed workpieces 2 are sequentially transported to the adjacent press machine 3. Each press machine 3 is equipped with a die 4. For example, the conveying device 1 may be configured to load unprocessed workpieces 2 into the leftmost press machine 3 in Figure 1, transport the processed workpieces 2 sequentially to the press machine 3 on the right, and then the conveying device 1 at the rightmost press machine 3 may unload the completed workpieces 2. By arranging multiple conveying devices 1 in a line of multiple single-stage press machines 3 in this way, production efficiency is improved, and the flexibility of the production line is increased.

[0019] The transport device 1 includes a fixed base 10, a swivel body 26 supported by the fixed base 10 via bearings 16 (Figure 3), two or more servo motors (30, 31) fixed to the fixed base 10 and rotating the swivel body 26 relative to the fixed base 10, a transport arm 50 configured to swivel together with the swivel body 26 to transport the workpiece 2, and two or more reduction gears 40 fixed to the fixed base 10 and connected to the two or more servo motors, respectively.

[0020] In this embodiment, two or more servo motors are described as a first servo motor 30 and a second servo motor 31. There may be three or more servo motors. The first servo motor 30 and the second servo motor 31 are fixed to the fixed base 10 and can rotate the slewing body 26 relative to the fixed base 10. Two or more reduction gears 40 are fixed to the fixed base 10. The number of reduction gears 40 may be three or more, corresponding to the number of servo motors. The transport device 1 may include a control device 6 that controls the operation of the transport device 1, including the servo motors.

[0021] The fixed base 10 is installed, for example, on the factory floor FL. The fixed base 10 has a mounting portion 18 that protrudes laterally from the top of the fixed base 10. The mounting portion 18 has protruding portions 18a and 18b that protrude significantly from the fixed base 10 at positions opposite each other on either side of the first rotation axis 24. The reduction gear 40 is fixed to the protruding portions 18a and 18b of the mounting portion 18, respectively. The first servo motor 30 and the second servo motor 31 are fixed to the mounting portion 18 via the housing 41 (Figure 3) of the reduction gear 40. The first servo motor 30 and the second servo motor 31 can rotate the slewing body 26 around the first rotation axis 24 relative to the fixed base 10. The first rotation axis 24 is, for example, a virtual line at the center of the slewing body 26 and extending vertically. The second rotation axis 34 and the third rotation axis 35 are set parallel to the first rotation axis 24.

[0022] The transport arm 50 is configured to rotate with the swivel body 26 to transport the workpiece 2. The transport arm 50 is fixed to the swivel body 26. The transport device 1 can be a so-called articulated robot, for example, a 6-axis robot. The transport arm 50 includes a plurality of elongated members, for example, a first arm 51, a second arm 52, and an elongated member 53. The transport arm 50 may include, for example, a first drive mechanism 61, a second drive mechanism 62, a third drive mechanism 63, a fourth drive mechanism 64, and a fifth drive mechanism 65. The first to fifth drive mechanisms 61 to 65 may each include a servo motor. One end of the first arm 51 is rotatably connected to the swivel body 26 via a fixed part 60. The fixed part 60 is connected to the swivel body It is integrated with part 26. The first drive mechanism 61 rotates the first arm 51 up and down to raise and lower the free end of the first arm 51. The second arm 52 is rotatably connected to the free end of the first arm 51. The second drive mechanism 62 rotates the second arm 52 up and down relative to the free end of the first arm 51 to raise and lower the free end on the long member 53 side. The third drive mechanism 63 rotates the second arm 52 around its central axis. The long member 53 is connected to the free end of the second arm 52. The fourth drive mechanism 64 rotates the long member 53 up and down to raise and lower the suction member 54. The fifth drive mechanism 65 rotates the long member 53 horizontally. Multiple suction members 54, for example four, are connected to the free end of the long member 53. Multiple suction members 54 adhere to the surface of the workpiece 2 and hold the workpiece 2. Furthermore, the transport arm 50 can appropriately adopt the transport arm structure of a known articulated robot, and the suction member 54 is not limited to a suction mechanism as long as it can hold the workpiece 2; for example, a gripping mechanism may also be used.

[0023] Workpiece 2 can be a metal sheet for press working or a product after press working. The conveying device 1 drives the first servo motor 30 and the second servo motor 31 to rotate the swivel body 26 and the conveying arm 50 horizontally around the first rotation axis 24 to convey the workpiece 2 onto the press machine 3. This conveying operation, for example, uses the first drive mechanism 61 to the fifth drive mechanism 65 to rotate the first arm 51, the second arm 52 and the long member 53 to raise, lower and move the workpiece 2 horizontally, and convey the workpiece 2 to the appropriate position on the die 4 of the adjacent press machine 3. Press-worked products tend to be heavy, and there is a need to improve the productivity of press working. With the conveying device 1, even when conveying a metal workpiece 2 used for press working, it is possible to increase the conveying speed of the workpiece 2. In this embodiment, an example of conveying workpiece 2 to a press machine 3 is described, but it may also be placed adjacent to equipment other than the press machine 3. For example, in the case of a machine tool, workpiece 2 can be a workpiece or material after machining, and in the case of an injection molding machine, workpiece 2 can be a plastic product or an insert.

[0024] The control device 6 is electrically connected to each operating part of the conveying device 1. The control device 6 may receive signals from sensors (not shown) of the conveying device 1. The control device 6 may also be part of the control device of the press machine 3. The control device 6 includes, for example, an operation unit, a calculation unit, a storage unit, a display unit, and an output unit. The control device 6 includes, for example, a processor such as a CPU (Central Processing Unit) or GPU (Graphics Processing Unit), storage media such as ROM (Read Only Memory), RAM (Random Access Memory), or HDD (Hard Disk Drive), a communication interface for high-speed data communication, and a user interface such as a display, touch panel, or keyboard. Part or all of the control device 6 may be located on the cloud via the internet.

[0025] The transport operation in the transport device 1 can be pre-set using the operation unit. The display unit can display the settings and execution status of the transport operation. The calculation unit executes each process necessary to carry out the set transport operation. Then, the transport device 1 can operate according to the transport operation stored in the memory unit based on command signals from the output unit of the control device 6.

[0026] 2. Explanation of the reduction mechanism The deceleration mechanism of the conveying device 1 will be explained in detail using Figures 3 to 5. Figure 3 is a cross-sectional view AA of Figure 2, Figure 4 is a cross-sectional view BB of Figure 3, and Figure 5 is a cross-sectional view CC of Figure 3.

[0027] The fixed base 10 is positioned on the floor FL and supports the swivel body 26 and the transport arm 50 so that they can swivel. The fixed base 10 is substantially cylindrical, for example, penetrating vertically along the first rotation axis 24. The inner ring 16a of the bearing 16 is fixed to the outer peripheral edge of the upper end of the fixed base 10. The outer ring 16b of the bearing 16 is fixed to the inner circumferential surface of the annular end 27 of the swivel body 26. 6 is a rolling bearing comprising balls or rollers between an outer ring 16b and an inner ring 16a. The bearing 16 is arranged, for example, in a single horizontal plane. The bearing 16 is, for example, a cross-roller bearing. The fixed base 10 has, for example, a substantially annular mounting portion 18 that protrudes laterally from the upper outer peripheral edge of the fixed base 10, which is lower than the bearing 16.

[0028] The mounting portion 18 is provided integrally with the fixed base 10. The mounting portion 18 extends from below to above the large gear 14 so as to cover the outside of the large gear 14 and the first and second output gears 46a and 46b. When viewed from above, the mounting portion 18 is roughly circular along the outer edge of the fixed base 10, but has large protruding portions 18a and 18b that project laterally to which the first servo motor 30 and the second servo motor 31 are mounted. The lower inner edge of the mounting portion 18 is below the bearing 16 and extends outward from the outer surface of the fixed base 10. The upper inner end surface of the mounting portion 18 has a small gap with respect to the annular end 27 of the swivel body 26. A sealing member S is fixed in this gap to prevent foreign objects from falling into the internal space of the mounting portion 18. The mounting portion 18 has two large protruding parts 18a and 18b that extend outwards to the side. The first servo motor 30 and the second servo motor 31 are fixed to these parts via the housing 41 of the reduction gear 40.

[0029] The housing 41 is integrated with the fixed base 10. For example, two housings 41 are fixed in positions facing each other with the fixed base 10 in between. The housing 41 is fixed to the mounting portion 18 so as to hang down from the lower surfaces of the protruding portions 18a and 18b of the mounting portion 18. The housing 41 is substantially cylindrical with openings at the top and bottom. The upper end of the housing 41 extends and is fixed to the inside of the mounting portion 18, for example. A first servo motor 30 and a second servo motor 31 are fixed to the lower ends of the two housings 41, respectively. The first servo motor 30 and the second servo motor 31 are fixed to the fixed base 10 via the housing 41 and the mounting portion 18, and are always in a constant position relative to the fixed base 10. While the slewing body 26 is rotating around the first rotation axis relative to the fixed base 10, the first servo motor 30 and the second servo motor 31 maintain a stationary state in a constant position. Therefore, the first servo motor 30 and the second servo motor 31 do not contribute to increasing the moment of inertia of the swivel unit 25 during the swivel motion. The swivel unit 25 is the part that swivels relative to the fixed base 10 and includes a swivel body 26, a fixed part 60, and a transport arm 50. Since the first servo motor 30 and the second servo motor 31 do not contribute to increasing the moment of inertia of the swivel unit 25, the first servo motor 30 and the second servo motor 31 can significantly increase the rotational angular acceleration of the swivel unit 25. In other words, this reduction mechanism makes it possible to increase the acceleration and deceleration of the swivel arm 50, and the transport operation of the transport device 1 can be made faster. Furthermore, because the first servo motor 30 and the second servo motor 31 are in a fixed position, the wiring 36 of the first servo motor 30 and the second servo motor 31 is less affected by the swivel motion even while the swivel unit 25 is performing the swivel motion. Therefore, the risk of the wiring 36 being disconnected during the operation of the transport device 1 can be avoided.

[0030] The swivel body 26 has a large gear 14, which is an external gear. The swivel body 26 comprises a flat disc-shaped portion that covers the upper end of the fixed base 10 from above, and a cylindrical annular end portion 27 that hangs down from the outer peripheral edge of the disc-shaped portion. The annular end portion 27 is provided so as to cover the outside of the outer peripheral edge of the upper end of the fixed base 10. A fixing portion 60 is provided on the upper surface of the swivel body 26, and the base end of the transport arm 50 is rotatably fixed to the fixing portion 60. By rotating the swivel body 26 around the first rotation axis 24 relative to the fixed base 10 by the drive of the first servo motor 30 and the second servo motor 31, the transport arm 50 can be swiveled around the first rotation axis 24. The large gear 14 is provided around the entire circumference of the outer peripheral surface of the annular end portion 27. An outer ring 16b is fixed to the inner peripheral surface of the annular end portion 27 at the same height as the large gear 14.

[0031] An opening 22 may be formed in the fixed base 10 and the swivel body 26 along the first rotation axis 24. The transport device 1 may be configured such that wiring (not shown) extends from the fixed base 10 to the servo motors of the first to fifth drive mechanisms 61 to 65 so as to pass through the opening 22 vertically. According to the transmission device 1, an opening 22 can be provided inside the large gear 14, making it possible to route wiring using the opening 22. The wiring may include signal lines to sensors (not shown). The wiring may also extend to the lower part of the fixed base 10 and be connected to the control device 6.

[0032] The gearbox 40 comprises a housing 41, a planetary carrier 42, an internal gear 43, a sun gear 44, a plurality of planetary gears 45, and a first output gear 46a or a second output gear 46b. In the gearbox 40 and first servo motor 30 on the left side of Figure 3, the output shaft 32 of the first servo motor 30, the planetary carrier 42, and the first output gear 46a rotate around a second rotation axis 34. In the gearbox 40 and second servo motor 31 on the right side of Figure 3, the output shaft 32 of the second servo motor 31, the planetary carrier 42, and the second output gear 46b rotate around a third rotation axis 35. The first rotation axis 24, the second rotation axis 34, and the third rotation axis 35 can be parallel to each other. The second rotation axis 34 and the third rotation axis 35 are located opposite each other with the first rotation axis 24 in between in a plan view (e.g., Figure 5). The distance from the second rotation axis 34 to the first rotation axis 24 is the same as the distance from the third rotation axis 35 to the first rotation axis 24.

[0033] The following description concerns the reduction gear 40 shown on the left in Figures 3 and 5, of two reduction gears 40 with essentially the same configuration. The planetary carrier 42 is rotatably supported inside the housing 41. The planetary carrier 42 is substantially cylindrical and is attached to the housing 41 via bearings located at two locations, upper and lower, on the outer circumference of the planetary carrier 42. The first output gear 46a is integrally fixed to the upper end of the planetary carrier 42. The rotation axis of the output shaft 32 is the second rotation axis 34. Therefore, as the planetary carrier 42 rotates around the second rotation axis 34, the first output gear 46a rotates around the second rotation axis 34. An annular sealing member S is provided between the upper inner surface of the housing 41 (above the bearing) and the outer surface of the planetary carrier 42. The sealing member S is an oil seal, and the sealing member S seals the lubricating oil inside the narrow housing 41, minimizing the amount of oil used in the planetary reduction mechanism.

[0034] The internal gear 43 is located inside the housing 41. The internal gear 43 is integrally formed on the inner surface of the cylindrical housing 41 so as to surround the outer circumference of the planetary carrier 42. The internal gear 43 is formed in a plane perpendicular to the second rotation axis 34, in this case, within a single horizontal plane.

[0035] The sun gear 44 is connected to the output shaft 32 of the first servo motor 30. The sun gear 44 is located on the outer circumference of the upper end of the rod connected to the output shaft 32. The rod extends from the output shaft 32 to the inside of the planetary carrier 42 along the second rotation axis 34. The sun gear 44 is an external gear and transmits the rotation of the output shaft 32 to the reduction gear 40.

[0036] Multiple planetary gears 45 are arranged around the sun gear 44 and rotatably supported by the planetary carrier 42. In this embodiment, there are three planetary gears 45 as shown in Figure 4, but the number is not limited to this, and there may be four or more. The rotation axis 45a of the planetary gear 45 is rotatably supported at the top and bottom by the planetary carrier 42. Alternatively, the rotation axis 45a may be fixed to the planetary carrier 42 at the top and bottom, allowing the planetary gear 45 to rotate relative to the rotation axis 45a. The rotation axis 45a is parallel to the second rotation axis 34. The rotation axis 45a is arranged around the second rotation axis 34, and a portion of the planetary gear 45 is positioned to protrude outward from the outer circumferential surface of the planetary carrier 42. Each planetary gear 45 meshes with the sun gear 44 on the central side of the planetary carrier 42, and meshes with the internal gear 43 at a position protruding from the planetary carrier 42.

[0037] The first output gear 46a rotates integrally with the planetary carrier 42. The first output gear 46a has a smaller diameter than the large gear 14 and meshes with the large gear 14 on its outside. The first output gear 46a is an external gear with a larger outer diameter than the planetary carrier 42. The first output gear 46a is covered on its outside and underside by a protruding portion 18a.

[0038] Therefore, when the transport device 1 drives the first servo motor 30, as shown in Figure 4, the output shaft 32 and the sun gear 44 rotate, the three planetary gears 45 that mesh with the sun gear 44 rotate, and each planetary gear 45 meshes with the internal gear 43, so each planetary gear 45 rolls along the internal gear 43 and rotates the planetary carrier 42 relative to the housing 41. Then, as the planetary carrier 42 rotates, as shown in Figure 5, the first and second output gears 46a and 46b rotate, so that the large gear 14 rotates, and the slewing body 26 (annular end 27) on which the large gear 14 is attached rotates about the first rotation axis 24 relative to the fixed base 10.

[0039] According to the conveying device 1, by utilizing planetary gears 45, heat generation in the reduction gear 40 can be suppressed even when the rotation speed of the slewing body 26 and the conveying arm 50 is increased by the first servo motor 30. Furthermore, according to the conveying device 1, by arranging two or more reduction gears 40 around the slewing body 26 having the large external gear 14, it is possible to ensure a high reduction ratio while suppressing an increase in the overall size of the device. Moreover, since the reduction gears 40 can be positioned opposite each other across the rotation center of the large gear 14, it is easy to control the backlash between the large gear 14 and the first and second output gears 46a and 46b to cancel each other out. In addition, since the tangential stress on the large gear 14 generated between the large gear 14 and the first and second output gears 46a and 46b is in exactly opposite directions, the lifespan of the gears can be extended. Finally, according to the conveying device 1, it is possible to respond to the high speed required for the conveying operation of the workpiece 2 to the press machine 3.

[0040] According to the conveying device 1, the backlash is larger compared to the reduction mechanism in Patent Document 1, so malfunctions due to heat generation are less likely to occur even at high speeds. Furthermore, according to the conveying device 1, a higher reduction ratio can be obtained by using the large gear 14 and the output gear 46 compared to Patent Document 2, which uses a planetary carrier as the output shaft. Therefore, with the same motor output, it is easier to increase the rotational angular acceleration of the slewing body 26 and thus easier to increase the conveying speed.

[0041] In this embodiment, the rotational centerlines of all gears used in the reduction gear 40 are parallel to the first rotational axis 24 of the slewing body 26, but the embodiment is not limited to this, and a configuration that is not parallel may be used with known gear combinations.

[0042] Furthermore, the control device 6 may control the position of two or more servo motors (30, 31) to cancel out the backlash. By canceling out the backlash, high stopping position accuracy can be achieved at the workpiece 2 transfer position even at high speeds. Specifically, although there is backlash between the large gear 14 and the two output gears 46, the backlash during acceleration can be canceled out by controlling the gears to generate a large torque on one of the first output gears 46a and a small reverse torque on the other second output gear 46b, and the backlash can be canceled out by performing the opposite control during deceleration.

[0043] As an alternative, multiple speed reducers 40 may be connected vertically in multiple stages on the second and third rotation axes 34 and 35. By connecting multiple speed reducers 40 in multiple stages in this way, the reduction ratio can be increased. Therefore, for example, even if the first and second servo motors 30 and 31 are inexpensive and lightweight servo motors with low output torque, the output torque can be increased by the multiple speed reducers 40, making it possible to achieve high-speed rotation of the transport arm 50. Moreover, since the multiple speed reducers 40 are stacked along the second and third rotation axes 34 and 35 (perpendicular to the rotation plane of the transport arm 50), the increase in the distance between the first rotation axis 24, which is the rotation axis of the transport arm 50, and the center of gravity of the first and second servo motors 30 and 31 is suppressed. Consequently, the increase in the moment of inertia of the slewing body 26 including the speed reducers 40 is also suppressed, and the acceleration and deceleration of the transport arm 50 can be increased. As a result, continuous high-speed reciprocating motion of the transport arm 50 within a limited area (space), such as between press machines, can be achieved while keeping costs down.

[0044] The present invention is not limited to the embodiments described above, and various further modifications are possible, including configurations that are substantially identical to the configurations described in the embodiments (configurations with the same function, method, and results, or configurations with the same purpose and effect). The present invention also includes configurations in which non-essential parts of the configurations described in the embodiments are replaced. Furthermore, the present invention includes configurations that produce the same effects or achieve the same purpose as the configurations described in the embodiments. Furthermore, the present invention includes configurations that add known technology to the configurations described in the embodiments. [Explanation of symbols]

[0045] 1...Conveying device, 2...Workpiece, 3...Press machine, 4...Mold, 6...Control device, 10...Fixed base, 11...Machine frame, 14...Large gear, 16...Bearing, 16a...Inner ring, 16b...Outer ring, 18...Mounting part, 18a,18b...Protruding part, 22...Opening, 24...First rotation axis, 25...Slewing unit, 26...Slewing body, 27...Annular end, 30...First servo motor, 31...Second servo motor, 32...Output shaft, 34...Second rotation axis, 35...Third rotation axis, 36...Wiring 40…Reduction gear, 41…Housing, 42…Planetary carrier, 43…Internal gear, 44,44a…Sun gear, 45…Planetary gear, 45a…Rotating shaft, 46a…First output gear, 46b…Second output gear, 47…Output shaft, 50…Transport arm, 51…First arm, 52…Second arm, 53…Long member, 54 Suction member, 60…Fixed part, 61…First drive mechanism, 62…Second drive mechanism, 63…Third drive mechanism, 64…Fourth drive mechanism, 65…Fifth drive mechanism, S…Seal member

Claims

1. Fixed base and A swivel body supported on the aforementioned fixed base via a bearing, Two or more servo motors fixed to the aforementioned fixed base and rotating the swivel body relative to the fixed base, A transport arm configured to rotate together with the aforementioned swivel body to transport a workpiece, Two or more reduction gears fixed to the aforementioned fixed base and connected to the two or more servo motors, Includes, The aforementioned swivel body has a large gear which is an external gear, The reduction gear comprises a housing integrated with the fixed base, a planetary carrier rotatably supported inside the housing, an internal gear provided inside the housing, a sun gear connected to the output shaft of the servo motor, a plurality of planetary gears arranged around the sun gear and rotatably supported by the planetary carrier, and an output gear that rotates integrally with the planetary carrier. The planetary gear meshes with the sun gear and meshes with the internal gear. A conveying device characterized in that the output gear has a smaller diameter than the large gear and meshes with the large gear on the outside of the large gear.

2. In the conveying device according to claim 1, The two or more servo motors include a first servo motor and a second servo motor. The output gear includes a first output gear rotated by the first servo motor and a second output gear rotated by the second servo motor. The aforementioned large gear rotates around the first axis of rotation, A conveying device characterized in that the first output gear is located opposite the second output gear with respect to the first rotation axis.

3. In the conveying device according to claim 1 or claim 2, The conveying device is characterized in that the workpiece is a metal sheet for press working or a product after press working.

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