Industrial robot

Abstract

This industrial robot is equipped with a hollow reduction gear (21) disposed in a joint section and a reduction mechanism (22) for reducing the rotation of a motor and transmitting it to the hollow reduction gear (21). The input shaft (23) of the hollow reduction gear (21) is housed in the case body (25) of the hollow reduction gear (21), and a part of the fixed shaft (27), which is disposed at the center in the diameter direction of the hollow reduction gear (21), is disposed on the inner circumference side of the input shaft (23). The input rotation shaft (30) of the reduction mechanism (22) is provided with a retained support part (30c) that is rotatably held and supported in the case body (25), and is connected to the input shaft (23) inside the case body (25) and is also connected to the motor outside the case body (25). To prevent leakage of lubricant from the inside of the case body (25), a seal member (32) is positioned on the outer side of the retaining support member (30c), and the inner surface of the seal member (32) is in contact with the outer surface of the retaining support member (30c). The outer diameter of the retaining support member (30c) is smaller than the outer diameter of the fixed shaft (27).

Description

Technology Field

[0001] The present invention relates to an industrial robot. Background Technology

[0002] Conventionally, an industrial robot for transporting a glass substrate in a vacuum is known (see, for example, Patent Document 1). The industrial robot described in Patent Document 1 has two hands on which a substrate is mounted, an arm to which the two hands are connected, a swing arm to which the arm is connected, and a main body to which the swing arm is connected. The arm has two tip-side arms to which each of the two hands is rotatably connected toward the tip side, and a common arm part to which the base side of the two tip-side arms is rotatably connected and which is rotatably connected to the tip side of the swing arm.

[0003] The industrial robot described in Patent Document 1 comprises a first driving mechanism and a second driving mechanism that rotate the front-side arm portion relative to the common arm portion and rotate the hand relative to the front-side arm portion, and a third driving mechanism that rotates the common arm portion relative to the swing arm. The third driving mechanism comprises a motor and a reduction gear connected to the motor. The reduction gear is positioned at the joint portion connecting the swing arm and the common arm portion. The reduction gear is a hollow wave gear device. That is, the reduction gear is a hollow reduction gear. The input shaft of the reduction gear is formed in a hollow shape and is positioned at the center in the diameter direction of the reduction gear.

[0004] In the industrial robot described in Patent Document 1, the input shaft of the reduction gear is rotatably held and supported in the case body of the reduction gear. A pulley is fixed to one end of the input shaft and disposed outside the case body. Grease is contained inside the case body as a lubricant. An annular seal member is disposed on the outer circumference of the input shaft to prevent grease from leaking from inside the case body. The inner surface of the seal member contacts the outer surface of the input shaft with a predetermined contact pressure. A cylindrical fixed shaft is disposed on the inner circumference of the input shaft. Wiring, etc., extending from the first driving mechanism and the second driving mechanism are disposed on the inner circumference of the fixed shaft. Prior art literature

[0005] Japanese Patent Publication No. 2023-54398 The problem to be solved

[0006] In the industrial robot described in Patent Document 1, wiring and the like are arranged on the inner circumference of the fixed shaft in the reduction gear placed in the joint section, so the outer diameter of the fixed shaft tends to increase. Consequently, in this industrial robot, the outer diameter of the input shaft, which is arranged on the inner circumference of the fixed shaft, also tends to increase. If the outer diameter of the input shaft increases, even if the rotational speed of the input shaft is constant, the speed of the outer circumference of the input shaft (peripheral speed) increases, making it easy for heat to be generated between the outer circumference of the input shaft and the inner circumference of the seal member. If heat is generated between the outer circumference of the input shaft and the inner circumference of the seal member, the temperature of the grease contained in the case body rises, and there is a risk that the viscosity of the grease will decrease. Therefore, in the case of the industrial robot described in Patent Document 1, for example, if the industrial robot is used under strict operating conditions, the viscosity of the grease contained in the case body decreases, and there is a risk that the grease will leak from the inside of the case body.

[0007] Therefore, the objective of the present invention is to provide an industrial robot in which a hollow reduction gear is disposed in a joint portion, capable of suppressing leakage of lubricant from the inside of the hollow reduction gear's case body even when the industrial robot is used, for example, under severe operating conditions. means of solving the problem

[0008] To solve the above problem, an industrial robot of one embodiment of the present invention comprises an industrial robot having a joint portion, wherein the industrial robot comprises a motor, a hollow reduction gear disposed in the joint portion, and a reduction mechanism for reducing the rotation of the motor and transmitting it to the hollow reduction gear. The hollow reduction gear comprises an input shaft formed in a hollow shape, a case body that rotatably holds and supports the input shaft, and a cylindrical fixed shaft that is fixed to the case body and disposed at the center of the diameter direction of the hollow reduction gear. The reduction mechanism comprises an input rotating shaft connected to the input shaft and the motor, and an annular seal member for preventing leakage of lubricant from the inside of the case body. The input shaft is disposed inside the case body, and a part of the fixed shaft is disposed on the inner circumference of the input shaft. The input rotating shaft has a retained support portion that is rotatably held and supported by the case body. It is connected to the input shaft inside the case body and is connected to the motor outside the case body. The axis of the input shaft and the axis of the input rotating shaft are disposed at positions offset from each other, and the seal member is retained It is characterized by being positioned on the outer side of the support member, the inner surface of the seal member contacting the outer surface of the support member to be held, and the outer diameter of the support member to be held being smaller than the outer diameter of the fixed shaft.

[0009] In the industrial robot of this type, the reduction mechanism for reducing the rotation of a motor and transmitting it to a hollow reduction gear comprises an input shaft of the hollow reduction gear and an input rotating shaft connected to the motor, and the axis of the input shaft and the axis of the input rotating shaft are positioned offset from each other. Furthermore, in this type, the input shaft is positioned inside the case body, and the input rotating shaft is connected to the input shaft inside the case body and is also connected to the motor outside the case body. Additionally, in this type, the outer diameter of the support portion of the input rotating shaft, which is contacted by the inner circumferential surface of a seal member to prevent leakage of lubricant from inside the case body, is smaller than the outer diameter of the fixed shaft.

[0010] Therefore, in this configuration, wiring, for example, is arranged on the inner side of a cylindrical fixed shaft positioned on the inner side of the input shaft, so that even if the outer diameters of the fixed shaft and the input shaft are large, it becomes possible to reduce the outer diameter of the support portion holding the input rotating shaft. Consequently, in this configuration, it becomes possible to reduce the speed (peripheral speed) of the outer surface of the support portion holding the input shaft that contacts the inner surface of the seal member. As a result, in this configuration, it becomes possible to suppress heat generation between the outer surface of the support portion holding the input rotating shaft and the inner surface of the seal member. Therefore, in this configuration, even if an industrial robot is used under strict operating conditions, for example, it becomes possible to suppress the decrease in viscosity of the lubricant contained in the case body and to suppress leakage of the lubricant from the inside of the case body.

[0011] Furthermore, in this configuration, since the rotation of the motor is reduced by a reduction mechanism and transmitted to a hollow reduction gear, it becomes possible to lower the rotational speed of the input shaft rotating inside the case body. Consequently, in this configuration, it becomes possible to suppress heat generation inside the case body. As a result, in this configuration, even when an industrial robot is used under strict operating conditions, for example, it becomes possible to effectively suppress the decrease in viscosity of the lubricant contained in the case body and effectively suppress the leakage of the lubricant from inside the case body. Effects of the invention

[0012] As described above, in one embodiment of the present invention, in an industrial robot having a hollow reduction gear disposed in a joint portion, it is possible to suppress leakage of lubricant from the inside of the hollow reduction gear's case body even when the industrial robot is used, for example, under strict operating conditions. Brief explanation of the drawing

[0013] FIG. 1 is a plan view of an industrial robot according to an embodiment of the present invention. Figure 2 is a side view of the industrial robot illustrated in Figure 1. FIG. 3 is a cross-sectional view for explaining the internal configuration of the base of the arm and the swing arm shown in FIG. 2. Figure 4 is an enlarged view of section E of Figure 3. Specific details for implementing the invention

[0014] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0015] (Composition of industrial robots)

[0016] FIG. 1 is a plan view of an industrial robot (2) according to an embodiment of the present invention. FIG. 2 is a side view of the industrial robot (2) shown in FIG. 1.

[0017] The industrial robot (2) of this type (hereinafter referred to as “Robot (2)”) is a robot for transporting, for example, a glass substrate (3) for an organic EL (organic electroluminescence) display or a glass substrate (3) for a liquid crystal display (hereinafter referred to as “Substrate (3)”) that is a transport object. The robot (2) is a horizontal multi-joint robot used in a manufacturing system for displays. The robot (2) transports the substrate (3) in a vacuum.

[0018] The robot (2) is equipped with a hand (4, 5) on which a substrate (3) is mounted, an arm (6) to which the hand (4, 5) is connected, a swing arm (7) to which the arm (6) is connected, and a main body (8) to which the swing arm (7) is connected. The robot (2) of this type is equipped with two hands (4, 5). The hands (4, 5) are rotatably connected to the front end of the arm (6). The base end of the arm (6) is rotatably connected to the front end of the swing arm (7). The base end of the swing arm (7) is rotatably connected to the main body (8). The swing arm (7) of this type is an arm support to which the base end of the arm (6) is rotatably connected.

[0019] The arm (6) is provided with two tip-side arm sections (10, 11) to which each of the two hands (4, 5) is rotatably connected to the tip side, and a common arm section (12) to which the base sides of the two tip-side arm sections (10, 11) are rotatably connected and which is rotatably connected to the tip side of the swing arm (7). The arm (6) of this form is composed of two tip-side arm sections (10, 11) and one common arm section (12). The hand (4) is rotatably connected to the tip side of the tip-side arm section (10). The hand (5) is rotatably connected to the tip side of the tip-side arm section (11).

[0020] The hand (4) is rotatably oriented in the up-and-down direction with respect to the tip-side arm (10) as the axis of rotation. The hand (5) is rotatably oriented in the up-and-down direction with respect to the tip-side arm (11) as the axis of rotation. The tip-side arm (10, 11) is rotatably oriented in the up-and-down direction with respect to the common arm (12) as the axis of rotation. The common arm (12) is rotatably oriented in the up-and-down direction with respect to the swing arm (7) as the axis of rotation. The swing arm (7) is rotatably oriented in the up-and-down direction with respect to the main body (8) as the axis of rotation.

[0021] The hand (4) is positioned above the hand (5). The tip arm (10) is positioned above the hand (4). The tip arm (11) is positioned below the hand (5). The common arm (12) is positioned below the tip arm (11). The common arm (12) is positioned above the swing arm (7). The swing arm (7) is positioned above the main body (8).

[0022] The main body (8) is provided with a case body (13) formed in a cylindrical shape with a bottom, and a cover body (14) that covers the opening at the top of the case body (13). The outer diameter of the cover body (14) is larger than the outer diameter of the case body (13). The outer circumference portion of the cover body (14) is formed as a flange portion (14b) that widens outward in the diameter direction of the case body (13). In this form, the portion above the lower surface of the flange portion (14b) of the robot (2) is placed in a vacuum chamber, and the hands (4, 5), arm (6), and swing arm (7) are placed in a vacuum area VR (in a vacuum). Meanwhile, the portion below the lower surface of the flange portion (14b) of the robot (2) is placed in an air area (AR) (in an air).

[0023] The tip-side arm (10, 11) is formed in a block shape with a relatively thin thickness in the vertical direction, with a shape that is long and slender when viewed from the vertical direction. The common arm (12) is formed in a block shape that is approximately V-shaped. The central part (apex part) of the common arm (12) formed in an approximately V-shape is rotatably connected to the tip side of the swing arm (7). In addition, the base side of the tip-side arm (10) is rotatably connected to one tip side of the common arm (12) formed in an approximately V-shape, and the base side of the tip-side arm (11) is rotatably connected to the other tip side of the common arm (12). The swing arm (7) is formed in a block shape that is relatively thin in the vertical direction, with a shape that is long and slender when viewed from the vertical direction.

[0024] The tip-side arm portions (10, 11) and the common arm portion (12) are formed in a hollow shape. That is, the arm (6) is formed in a hollow shape. In addition, the swing arm (7) is formed in a hollow shape. The interior of the tip-side arm portions (10, 11) formed in a hollow shape is a vacuum. Meanwhile, the interior of the common arm portion (12) and the swing arm (7) formed in a hollow shape is at atmospheric pressure. In addition, the interior of the main body portion (8) is at atmospheric pressure.

[0025] In the horizontal direction, the distance between the rotation center of the common arm (12) relative to the swing arm (7) and the rotation center of the front arm (10) relative to the common arm (12), and the distance between the rotation center of the front arm (10) relative to the common arm (12) and the rotation center of the hand (4) relative to the front arm (10) are equal, and the distance between the rotation center of the common arm (12) relative to the swing arm (7) and the rotation center of the front arm (11) relative to the common arm (12), and the distance between the rotation center of the front arm (11) relative to the common arm (12) and the rotation center of the hand (5) relative to the front arm (11) are equal. In addition, in the horizontal direction, the distance between the center of rotation of the common arm (12) with respect to the swing arm (7) and the center of rotation of the front arm (10) with respect to the common arm (12), and the distance between the center of rotation of the common arm (12) with respect to the swing arm (7) and the center of rotation of the front arm (11) with respect to the common arm (12) are the same.

[0026] The arm (6) is capable of being extended relative to the swing arm (7) between a position where the tip of the hand (4, 5) is extended away from the joint portion (16), which is the connection portion between the swing arm (7) and the common arm portion (12) (i.e., the connection portion between the arm (6) and the swing arm (7)), and a position where the tip of the hand (4, 5) is contracted towards the joint portion (16). In this form, when the part of the arm (6) on the tip side arm portion (10) is extended so that the tip of the hand (4) is moved away from the joint portion (16), the part of the arm (6) on the tip side arm portion (11) is contracted, and when the part of the arm (6) on the tip side arm portion (11) is extended so that the tip of the hand (5) is moved away from the joint portion (16), the part of the arm (6) on the tip side arm portion (10) is contracted. When the arm (6) extends relative to the swing arm (7), the hands (4, 5) move linearly in a horizontal direction while facing a certain direction relative to the swing arm (7).

[0027] The robot (2) is equipped with an arm driving mechanism that rotates the arm (6) relative to the swing arm (7) while moving the hands (4, 5) linearly in a horizontal direction relative to the swing arm (7), a swing arm driving mechanism that rotates the swing arm (7) relative to the main body (8), and a swing arm lifting mechanism that raises the swing arm (7) relative to the main body (8). The swing arm driving mechanism is equipped with a motor and a reduction gear, etc., which are housed in a case body (13). The swing arm lifting mechanism raises the swing arm (7) together with the swing arm driving mechanism. The swing arm lifting mechanism is housed in a case body. The swing arm lifting mechanism is equipped with a motor and a ball screw, etc., which rotates by the power of the motor. The configuration of the arm driving mechanism is described below.

[0028] (Composition of arm drive mechanism)

[0029] FIG. 3 is a cross-sectional view for explaining the base portion of the arm (6) and the internal configuration of the swing arm (7) shown in FIG. 2. FIG. 4 is an enlarged view of portion E of FIG. 3.

[0030] The arm driving mechanism extends and retracts the arm (6) relative to the swing arm (7) to move the hands (4, 5) linearly in the horizontal direction (i.e., by extending and retracting the arm (6), the hands (4, 5) are moved linearly in the horizontal direction relative to the swing arm (7)) and rotates the common arm portion (12) relative to the swing arm (7). The arm driving mechanism is equipped with a common arm portion driving mechanism (18) that rotates the common arm portion (12) relative to the swing arm (7). Additionally, the arm driving mechanism is equipped with a first front arm portion driving mechanism that rotates the front arm portion (10) relative to the common arm portion (12) and rotates the hand (4) relative to the front arm portion (10), and a second front arm portion driving mechanism that rotates the front arm portion (11) relative to the common arm portion (12) and rotates the hand (5) relative to the front arm portion (11).

[0031] The common arm drive mechanism (18) is equipped with a motor (20), a hollow reduction gear (21) (hereinafter referred to as "reduction gear (21)") disposed in the joint part (16), and a reduction mechanism (22) for reducing the rotation of the motor (20) and transmitting it to the reduction gear (21). The motor (20) is a servo motor. The motor (20) is disposed inside the swing arm (7). A pulley (19) is fixed to the output shaft of the motor (20). The reduction gear (21) and the reduction mechanism (22) reduce the rotation of the motor (20) and transmit it to the common arm (12).

[0032] The reduction gear (21) is an eccentric oscillating type reduction gear (RV reduction gear). The reduction ratio of the reduction gear (21) is, for example, 1 / 30. A through hole is formed at the center of the reduction gear (21) in the diameter direction. The through hole penetrates the reduction gear (21) in the vertical direction. The lower part of the reduction gear (21) is placed inside the swing arm (7). The reduction gear (21) is provided with an input shaft (23) and an output shaft (24) formed in a hollow shape, a case body (25) that rotatably holds and supports the input shaft (23) and the output shaft (24), a magnetic fluid seal (26) placed on the outer circumference of the output shaft (24), and a cylindrical fixed shaft (27) placed at the center of the reduction gear (21) in the diameter direction.

[0033] The input shaft (23) is positioned so that its axial direction and vertical direction align. The input shaft (23) is rotatably supported in the lower part of the case body (25) through a bearing. The output shaft (24) is positioned so that its axial direction and vertical direction align. The output shaft (24) is positioned above the input shaft (23). The output shaft (24) is rotatably supported in the upper part of the case body (25) through a bearing. The input shaft (23) and the output shaft (24) are positioned on the same axis. The output shaft (24) is fixed to the base of the common arm (12). Specifically, the upper surface of the output shaft (24) is fixed to the lower surface of the base of the common arm (12). A through hole is formed in the base of the common arm (12) that leads to the inner circumference of the output shaft (24).

[0034] The case body (25) is fixed to the front end of the swing arm (7). Specifically, the upper end of the case body (25) is fixed to the upper surface of the front end of the swing arm (7). The fixed shaft (27) is fixed to the case body (25). The fixed shaft (27) is positioned so that its axial direction and vertical direction coincide. A portion of the fixed shaft (27) is positioned on the inner side of the input shaft (23). The inner side of the fixed shaft (27) is connected to the inner side of the output shaft (24). The inner side of the fixed shaft (27) and the inner side of the output shaft (24) are formed as through holes formed at the center of the diameter direction of the reduction gear (21). The inner diameter of the output shaft (24) is larger than the inner diameter of the fixed shaft (27).

[0035] The input shaft (23) is positioned inside the case body (25). That is, the input shaft (23) is housed in the case body (25). An input gear (23b) is integrally formed on the input shaft (23). The reduction gear (21) is equipped with three gears (28) that mesh with the input gear (23b), a crankshaft to which the gears (28) are fixed, and an RV gear installed on the crankshaft. The gears (28) are spur gears. The three gears (28) are housed in the case body (25). The three gears (28) are arranged on concentric circles centered on the axis of the input shaft (23). Additionally, the three gears (28) are arranged at a 120° pitch centered on the axis of the input shaft (23). Grease as a lubricant is housed in the part of the case body (25) where the input shaft (23) and gears (28) are positioned.

[0036] The magnetic fluid seal (26) functions to prevent air from entering the vacuum region (VR) from the inside of the swing arm (7). As described above, the magnetic fluid seal (26) is positioned on the outer circumference of the output shaft (24). The magnetic fluid seal (26) is held and supported in the case body (25). Specifically, the magnet and pole piece of the magnetic fluid seal (26) are fixed to the inner circumference of the upper part of the case body (25). Magnetic fluid is held and supported between the inner circumference of the pole piece and the outer circumference of the output shaft (24).

[0037] The reduction mechanism (22) is positioned inside the swing arm (7). The reduction mechanism (22) is equipped with an input rotation shaft (30) connected to the input shaft (23) and the motor (20), a shaft holding support member (31) that rotatably holds and supports the input rotation shaft (30), and a seal member (32) to prevent leakage of lubricant (i.e., leakage of grease) from the inside of the case body (25). The input rotation shaft (30) is positioned so that the axial direction and the vertical direction of the input rotation shaft (30) coincide. The axis of the input rotation shaft (30) is positioned at a location offset from the axis of the input shaft (23). That is, the axis of the input shaft (23) and the axis of the input rotation shaft (30) are positioned at a location offset from each other.

[0038] The shaft-holding support member (31) is formed in a cylindrical shape. The shaft-holding support member (31) is positioned so that its axial direction and vertical direction coincide. The shaft-holding support member (31) is fixed to the case body (25). Specifically, the shaft-holding support member (31) is fixed to the bottom surface of the case body (25). A through hole is formed in the bottom surface of the case body (25) that extends from the bottom surface (lower surface) of the case body (25) into the interior of the case body (25), and the upper end of the shaft-holding support member (31) is positioned inside this through hole. A part of the input rotation shaft (30) is positioned on the inner circumference side of the shaft-holding support member (31). A bearing that rotatably supports the input rotation shaft (30) is positioned on the inner circumference side of the shaft-holding support member (31). The input rotation shaft (30) is rotatably held and supported in the case body (25) through a bearing and a shaft holding support member (31).

[0039] At the upper end (one end) of the input rotating shaft (30), a gear (30b) is integrally formed and disposed inside the case body (25). The gear (30b) meshes with the input gear (23b). That is, the input rotating shaft (30) is connected to the input shaft (23) inside the case body (25). The outer diameter of the gear (30b) is smaller than the outer diameter of the input gear (23b). At the lower end (the other end) of the input rotating shaft (30), a pulley (33) disposed outside the case body (25) is fixed. That is, the reduction mechanism (22) is equipped with a pulley (33). A belt (34) is stretched over the pulley (19) and the pulley (33) which are fixed to the output shaft of the motor (20). That is, the input rotating shaft (30) is connected to the motor (20) outside the case body (25). The outer diameter of the pulley (33) is larger than the outer diameter of the gear (30b).

[0040] As described above, the input rotation shaft (30) is rotatably held and supported in the case body (25) through a bearing and a shaft holding support member (31). A portion of the input rotation shaft (30) positioned on the inner side of the shaft holding support member (31) is formed as a retained support portion (30c) that is rotatably held and supported in the case body (25). That is, the input rotation shaft (30) is equipped with a retained support portion (30c). The retained support portion (30c) is formed in a cylindrical shape. Specifically, the retained support portion (30c) is formed in a stepped cylindrical shape. The outer diameter of the retained support portion (30c) is smaller than the outer diameter of the fixed shaft (27).

[0041] The seal member (32) is a rubber oil seal formed in an annular shape. The seal member (32) is positioned on the inner circumference side of the shaft holding support member (31). Specifically, the seal member (32) is positioned on the inner circumference side of the upper portion of the shaft holding support member (31). Additionally, the seal member (32) is positioned on the outer circumference side of the input rotating shaft (30). Specifically, the seal member (32) is positioned on the outer circumference side of the support member to be held (30c). The inner surface of the seal member (32) is in contact with the outer surface of the support member to be held (30c) with a predetermined contact pressure.

[0042] As described above, the outer diameter of the retained support member (30c) is smaller than the outer diameter of the fixed shaft (27). In this form, the outer diameter of the portion where the inner surface of the seal member (32) of the retained support member (30c) contacts is formed as the maximum outer diameter of the retained support member (30c), which is formed as a stepped cylindrical shape, and the outer diameter of the portion where the inner surface of the seal member (32) of the retained support member (30c) contacts is smaller than the outer diameter of the fixed shaft (27).

[0043] The first end-side arm drive mechanism and the second end-side arm drive mechanism, like the common arm drive mechanism (18), are equipped with a motor corresponding to the motor (20), a reduction gear corresponding to the reduction gear (21), and a reduction gear mechanism corresponding to the reduction gear mechanism (22). The motor of the first end-side arm drive mechanism and the motor of the second end-side arm drive mechanism are positioned inside the common arm (12). The wiring drawn from the motor of the first end-side arm drive mechanism and the wiring drawn from the motor of the second end-side arm drive mechanism are wired to pass through the inner circumference of the output shaft (24) and the inner circumference of the fixed shaft (27).

[0044] The reduction gear of the first end-side arm drive mechanism is positioned in the joint portion (36) which serves as the connection between the common arm portion (12) and the end-side arm portion (10), and the reduction gear of the second end-side arm drive mechanism is positioned in the joint portion (37) which serves as the connection between the common arm portion (12) and the end-side arm portion (11). The output shaft of the reduction gear of the first end-side arm drive mechanism is fixed to the lower surface of the base portion of the end-side arm portion (10) through a rotating shaft (38) (see FIG. 1) formed in a cylindrical shape. The output shaft of the reduction gear of the second end-side arm drive mechanism is fixed to the lower surface of the base portion of the end-side arm portion (11).

[0045] The first tip-side arm drive mechanism comprises a pulley that is positioned inside the base side of the tip-side arm (10) and fixed to one tip side of the common arm (12) via a fixing member (39), a pulley that is positioned inside the tip side of the tip-side arm (10) and fixed to the base side of the hand (4), and a belt that spans these two pulleys. The fixing member (39) is positioned outside the tip-side arm (10) and the common arm (12). A support shaft that rotatably supports the pulley is installed inside the base side of the tip-side arm (10) and inside the tip side of the tip-side arm (10).

[0046] The second tip-side arm drive mechanism is provided with a pulley that is positioned inside the base side of the tip-side arm (11) and fixed to the other tip-side of the common arm (12) via a fixing member (40), a pulley that is positioned inside the tip-side of the tip-side arm (11) and fixed to the base side of the hand (5), and a belt that spans these two pulleys. The fixing member (40) is positioned outside the tip-side arm (11) and the common arm (12). A support shaft that rotatably supports the pulley is installed inside the base side of the tip-side arm (11) and inside the tip-side of the tip-side arm (11).

[0047] (Main effect of this form)

[0048] As described above, in this embodiment, the axis of the input shaft (23) of the reduction gear (21) and the axis of the input rotation shaft (30) of the reduction mechanism (22) are positioned at a misaligned position. In addition, in this embodiment, the input shaft (23) is positioned inside the case body (25) of the reduction gear (21), and the input rotation shaft (30) is connected to the input shaft (23) inside the case body (25) and is also connected to the motor (20) outside the case body (25). Furthermore, in this embodiment, the outer diameter of the retaining support portion (30c) of the input rotation shaft (30), which contacts the inner circumference of the seal member (32) to prevent grease leakage from inside the case body (25), is smaller than the outer diameter of the fixed shaft (27) of the reduction gear (21).

[0049] Therefore, in this form, wiring is arranged on the inner side of the fixed shaft (27) which is positioned on the inner side of the input shaft (23), so that even if the outer diameters of the fixed shaft (27) and the input shaft (23) are large, it is possible to reduce the outer diameter of the retained support member (30c). Accordingly, in this form, it is possible to slow down the speed of the outer surface of the retained support member (30c) that contacts the inner surface of the seal member (32). As a result, in this form, it is possible to suppress heat generation between the outer surface of the retained support member (30c) and the inner surface of the seal member (32). Therefore, in this form, even if the robot (2) is used under strict operating conditions, for example, it is possible to suppress the decrease in viscosity of the grease contained in the case body (25) and suppress leakage of grease from the inside of the case body (25).

[0050] In addition, in this embodiment, the first end-side arm drive mechanism and the second end-side arm drive mechanism are equipped with a motor corresponding to the motor (20), a reduction gear corresponding to the reduction gear (21), and a reduction gear mechanism corresponding to the reduction gear mechanism (22), just like the common arm drive mechanism (18). Therefore, in this embodiment, even if the robot (2) is used under strict operating conditions, for example, it is possible to suppress the leakage of grease from the inside of the case body of the reduction gear of the first end-side arm drive mechanism, and it is also possible to suppress the leakage of grease from the inside of the case body of the reduction gear of the second end-side arm drive mechanism.

[0051] In this form, the rotation of the motor (20) is reduced by the reduction mechanism (22) and transmitted to the reduction gear (21). Therefore, in this form, it is possible to reduce the rotational speed of the input shaft (23) rotating inside the case body (25). Accordingly, in this form, it is possible to suppress heat generation inside the case body (25). As a result, in this form, even if the robot (2) is used under strict operating conditions, for example, the decrease in viscosity of the grease contained in the case body (25) is effectively suppressed, and the leakage of lubricant from inside the case body (25) is effectively suppressed.

[0052] Likewise, in this form, even if the robot (2) is used under strict operating conditions, for example, it is possible to effectively suppress the leakage of grease from the inside of the case body of the first end-side arm drive mechanism, and also to effectively suppress the leakage of grease from the inside of the case body of the second end-side arm drive mechanism.

[0053] In this form, the reduction gear (21) is an eccentric oscillating type reduction gear. Therefore, in this form, it is possible to reduce the reduction ratio of the reduction gear (21) compared to, for example, when the reduction gear (21) is a hollow wave gear device. Accordingly, in this form, compared to when the reduction gear (21) is a hollow wave gear device, it is possible to reduce the rotational speed of the input shaft (23) rotating inside the case body (25) more effectively, thereby effectively suppressing heat generation inside the case body (25). As a result, in this form, even when the robot (2) is used under strict operating conditions, for example, the decrease in viscosity of the grease contained in the case body (25) is more effectively suppressed, and the leakage of grease from inside the case body (25) is more effectively suppressed.

[0054] Likewise, in this form, even if the robot (2) is used under strict operating conditions, for example, it is possible to more effectively suppress the leakage of grease from inside the case body of the first end-side arm drive mechanism, and also to more effectively suppress the leakage of grease from inside the case body of the second end-side arm drive mechanism.

[0055] (Other embodiments)

[0056] Although the above-described form is an example of a suitable form of the present invention, it is not limited thereto, and various modifications are possible within the scope that does not alter the essence of the present invention.

[0057] In the above-described form, the reduction gear (21) may be a hollow reduction gear other than an eccentric oscillating type reduction gear. For example, the reduction gear (21) may be a hollow oscillating gear device. In addition, in the above-described form, a gear (30b) formed separately from the input rotation shaft (30) may be fixed to the input rotation shaft (30). In addition, in the above-described form, a pulley (33) may be formed integrally with the input rotation shaft (30).

[0058] In the above-described configuration, the first end-side arm drive mechanism does not need to be equipped with a reduction mechanism equivalent to the reduction mechanism (22), and the second end-side arm drive mechanism does not need to be equipped with a reduction mechanism equivalent to the reduction mechanism (22). In this case, the lower end of the input shaft of the reduction gear of the first end-side arm drive mechanism and the second end-side arm drive mechanism is positioned outside the case body of the reduction gear, and a belt is stretched over a pulley fixed to the lower end of the input shaft of the reduction gear and a pulley fixed to the output shaft of the motor.

[0059] In addition, in the above-described form, if the first end-side arm driving mechanism or the second end-side arm driving mechanism is equipped with a reduction mechanism corresponding to the reduction mechanism (22), the common arm driving mechanism (18) does not need to be equipped with the reduction mechanism (22). In this case, the lower end of the input shaft (23) is positioned outside the case body (25), and a belt (34) is stretched over a pulley and a pulley (19) that are fixed to the lower end of the input shaft (23).

[0060] In the above-described form, the robot (2) does not need to be equipped with a swing arm (7). In this case, the apex portion of the common arm (12), which is formed in a roughly V shape, is rotatably connected to the main body (8). In this case, the main body (8) is an arm support portion to which the base side of the arm (6) is rotatably connected. Furthermore, in the above-described form, the common arm (12) is formed in a roughly V-shaped block shape, but the common arm (12) may be formed in a block shape with a relatively thin thickness in the vertical direction, with the shape of the common arm (12) being a long, slender elliptical or rectangular shape when viewed from the vertical direction.

[0061] In the above-described form, the robot (2) may have two arms instead of an arm (6): an arm to which a hand (4) is rotatably connected to the tip side, and an arm to which a hand (5) is rotatably connected to the tip side. In this case, the arm is composed of, for example, two arm parts that are rotatably connected to each other. Also, in this case, for example, the robot (2) does not have a swing arm (7), and the base sides of the two arms are rotatably connected to the main body part (8).

[0062] In the above-described form, the number of hands provided by the robot (2) may be one. In this case, the robot (2) is provided with, for example, one arm to which the hand is rotatably connected to the tip side, and a main body part to which the base side of the arm is rotatably connected. In this case, the arm is composed of, for example, two or three arm parts that are rotatably connected to each other. Additionally, depending on the configuration of the robot (2), something other than wiring may be disposed on the inner circumference side of the fixed shaft (27). For example, as disclosed in Japanese Patent Publication No. 2020-69577, a hollow pivot shaft to which a pulley is fixed at the upper and lower ends may be disposed on the inner circumference side of the fixed shaft (27).

[0063] In the above-described form, the object to be transported by the robot (2) may be something other than a glass substrate. For example, the object to be transported by the robot (2) may be a semiconductor wafer, etc. Also, in the above-described form, the hand (4, 5), arm (6), and swing arm (7) may be placed in the atmosphere. That is, the robot (2) may transport the object to be transported in the atmosphere. Also, in the above-described form, the robot (2) is a horizontal multi-joint type robot for transporting the object to be transported, but the robot (2) may be a vertical multi-joint type robot used for other purposes, such as a welding robot.

[0064] (Composition of the present technology)

[0065] In addition, the present technology can be configured as follows.

[0066] (1) In an industrial robot equipped with joints,

[0067] The apparatus comprises a motor, a hollow reduction gear disposed in the joint portion, and a reduction mechanism for reducing the rotation of the motor and transmitting it to the hollow reduction gear.

[0068] The above hollow reduction gear comprises an input shaft formed in a hollow shape, a case body that rotatably holds and supports the input shaft, and a cylindrical fixed shaft that is fixed to the case body and positioned at the center in the diameter direction of the hollow reduction gear.

[0069] The above reduction gear mechanism comprises an input rotating shaft connected to the input shaft and the motor, and an annular seal member for preventing leakage of lubricant from the inside of the case body.

[0070] The above input shaft is positioned inside the case body, and

[0071] A portion of the above fixed shaft is positioned on the inner circumference side of the above input shaft, and

[0072] The above-mentioned input rotational shaft has a retained support member that is rotatably retained and supported in the case body, and is connected to the input shaft inside the case body and is also connected to the motor outside the case body.

[0073] The axis of the input shaft and the axis of the input rotation shaft are positioned at a misaligned position, and

[0074] The above seal member is positioned on the outer side of the above-mentioned retained support member, and

[0075] The inner surface of the above seal member contacts the outer surface of the above-mentioned retained support member, and

[0076] An industrial robot characterized in that the outer diameter of the above-mentioned support member is smaller than the outer diameter of the above-mentioned fixed shaft.

[0077] (2) At one end of the input rotating shaft, a gear is formed or fixed and disposed inside the case body, and

[0078] An industrial robot described in (1), characterized in that a pulley disposed outside the case body is formed or fixed at the other end of the input rotating shaft.

[0079] (3) A hand on which a return object is mounted, an arm rotatably connected to the front end of the hand, and an arm support rotatably connected to the base end of the arm.

[0080] At least, an industrial robot according to (1) or (2) characterized in that the connection between the arm and the arm support part is the joint part.

[0081] (4) An industrial robot described in any one of (1) to (3) characterized in that the above hollow reduction gear is an eccentric oscillating reduction gear.

[0082] In this form, for example, a gear disposed inside the case body is formed or fixed at one end of the input rotating shaft, and a pulley disposed outside the case body is formed or fixed at the other end of the input rotating shaft.

[0083] In the present embodiment, the industrial robot comprises, for example, a hand on which a conveying object is mounted, an arm rotatably connected to the front end of the hand, and an arm support member rotatably connected to the base end of the arm, and at least, the connection between the arm and the arm support member is a joint.

[0084] In this configuration, for example, the hollow reducer is an eccentric oscillating type reducer. In this case, compared to the case where the hollow reducer is a hollow wave gear device, for example, it becomes possible to reduce the reduction ratio of the hollow reducer. Consequently, compared to the case where the hollow reducer is a hollow wave gear device, it becomes possible to lower the rotational speed of the input shaft rotating inside the case body, thereby effectively suppressing heat generation inside the case body. As a result, even when an industrial robot is used under strict operating conditions, for example, the decrease in viscosity of the lubricant contained in the case body can be suppressed more effectively, and the leakage of the lubricant from inside the case body can be suppressed more effectively. Explanation of the symbols

[0085] 2: Robot (Industrial Robot) 3: Substrate (glass substrate, object to be returned) 4, 5: Hand 6: Cancer 7: Swing arm (arm support) 16, 36, 37: Joints 20: Motor 21: Reducer (Hollow Reducer) 22: Reduction mechanism 23: Input axis 25: Case type 27: Fixed axis 30: Input rotation axis 30b: Gear 30c: retained support 32: Absence of time 33: Pull Out

Claims

Claim 1 An industrial robot having a joint section comprises a motor, a hollow reduction gear disposed in the joint section, and a reduction mechanism for reducing the rotation of the motor and transmitting it to the hollow reduction gear. The hollow reduction gear comprises an input shaft formed in a hollow shape, a case body that rotatably holds and supports the input shaft, and a cylindrical fixed shaft that is fixed to the case body and disposed at the center in the diameter direction of the hollow reduction gear. The reduction mechanism comprises an input rotating shaft connected to the input shaft and the motor, and an annular seal member for preventing leakage of lubricant from the inside of the case body. The input shaft is disposed inside the case body, and a part of the fixed shaft is disposed on the inner circumference of the input shaft. The input rotating shaft has a retained support member that is rotatably held and supported by the case body. It is connected to the input shaft inside the case body and is connected to the motor outside the case body. The axis of the input shaft and the axis of the input rotating shaft are positioned offset from each other. An industrial robot characterized by being disposed, wherein the seal member is disposed on the outer side of the retained support member, the inner surface of the seal member contacts the outer surface of the retained support member, and the outer diameter of the retained support member is smaller than the outer diameter of the fixed shaft. Claim 2 An industrial robot according to claim 1, characterized in that a gear disposed inside the case body is formed or fixed at one end of the input rotating shaft, and a pulley disposed outside the case body is formed or fixed at the other end of the input rotating shaft. Claim 3 An industrial robot according to claim 1 or 2, comprising a hand on which a conveying object is mounted, an arm rotatably connected to the front end of the hand, and an arm support member rotatably connected to the base end of the arm, wherein at least the connection part between the arm and the arm support member is the joint member. Claim 4 An industrial robot characterized in that, in claim 1 or 2, the hollow reducer is an eccentric oscillating type reducer.

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