Vertical articulated robot

Abstract

This invention provides a vertical articulated robot that suppresses the scattering of lubricant contained in the reduction gear within the arm. [Solution] The vertical articulated robot has an arm 224 having a housing 24 with a through hole 31 including a recess 32, a reduction gear 29 provided on the outside of the arm 224 and containing a lubricant, an input member 28 inserted through the through hole 31 and inputting driving force to the reduction gear 29, a bearing 30 positioned in the recess 32 and supporting the input member 28 so as to be rotatable around its axis, and an absorbent member 50 positioned around the through hole 31 on the opposite side of the housing 24 from the reduction gear 29 and absorbing the lubricant, and the housing 24 has an inclined portion 35 between the edge of the through hole 31 and the absorbent member 50.

Description

Technical Field

[0001] The present invention relates to a vertical articulated robot.

Background Art

[0002] Patent Document 1 discloses a vertical articulated robot having a 6-axis arm on a base. Those arms are sequentially connected to be rotatable via joints. In this robot, a first frame and a second frame constituting the joint are connected to be rotatable about a rotation axis via a speed reducer. Further, in order to prevent the oil component of the lubricant accommodated in the speed reducer from leaking to the outside of the joint, a first felt member is provided at a position centered on the rotation axis on the first frame, and a second felt member is provided at a position surrounding the rotation axis on the surface of the second frame facing the first frame.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in a vertical articulated robot having such a configuration, it is impossible to prevent the lubricant leaked from the speed reducer from scattering inside the robot.

Means for Solving the Problems

[0005] A vertical articulated robot according to an application example of the present invention comprises an arm having a housing with a through hole including a recess, a reduction gear provided on the outside of the arm and containing a lubricant, an input member inserted through the through hole and inputting driving force to the reduction gear, a bearing disposed in the recess and supporting the input member so as to be rotatable around an axis, and an absorbent member disposed around the through hole on the side of the housing opposite to the reduction gear and absorbing the lubricant, wherein the housing has an inclined portion between the edge of the through hole and the absorbent member. [Brief explanation of the drawing]

[0006] [Figure 1] This is a perspective view showing the robot system according to the first embodiment. [Figure 2] This is a cross-sectional view showing the inside of the robot according to the first embodiment. [Figure 3] This is a magnified view showing a portion of area B in Figure 2. [Figure 4] Figure 3 shows a cross-sectional view of the robot when its posture changes. [Figure 5A] This figure shows an inclined portion according to a modified example of the first embodiment. [Figure 5B] This is a cross-sectional view along line BB in Figure 5A. [Figure 6] This is a cross-sectional view showing the inclined portion according to the second embodiment. [Figure 7] Figure 6 shows a cross-sectional view when the robot's posture changes. [Figure 8] Figure 6 shows a cross-sectional view when the robot's posture changes. [Figure 9] This is a cross-sectional view showing the inclined portion according to the third embodiment. [Figure 10] Figure 9 shows a cross-sectional view when the robot's posture changes. [Figure 11] Figure 9 shows a cross-sectional view when the robot's posture changes. [Modes for carrying out the invention]

[0007] Embodiments of the present invention will be described below with reference to the drawings. In the following drawings, the scale of each layer and component has been altered from that of the actual dimensions in order to make each layer and component recognizable.

[0008] For the sake of explanation, Figures 1, 4, 7, 8, 10, and 11 illustrate the X, Y, and Z axes as three mutually orthogonal axes. The Z axis is the axis along the vertical direction, with the +Z direction being vertically upward and the -Z direction being vertically downward. The direction along the X axis is called the "X-axis direction," the direction along the Y axis is called the "Y-axis direction," and the direction along the Z axis is called the "Z-axis direction." The tip of the arrow in each axis direction is also called the "+ side," and the base end is called the "- side."

[0009] Furthermore, for the sake of explanation, Figures 2, 3, 5A, 5B, 6, and 9 illustrate the x, y, and z axes as three mutually orthogonal axes. The x, y, and z axes are coordinate axes based on the arm 224, which will be described later. The direction along the x axis is called the "x-axis direction," the direction along the y axis is called the "y-axis direction," and the direction along the z axis is called the "z-axis direction." The tip of the arrow in each axis direction is also called the "+ side," and the base end is called the "- side." The plane parallel to the y and z axes is also called the "yz plane."

[0010] 1. First Embodiment Figure 1 is a perspective view showing a robot system 1 according to the first embodiment. The robot system 1 includes a robot 2 and a controller 20 that controls the driving of the robot 2.

[0011] Robot 2 is a vertical articulated robot with six drive axes. Robot 2 has a base 21 fixed to the floor and a robotic arm 22 connected to the base 21.

[0012] The robot arm 22 has arms 221, 222, 223, 224, 225, and 226. Arm 221 is connected to the base 21 and rotates relative to the base 21 around pivot axis J1. Arm 222 is connected to arm 221 and rotates relative to arm 221 around pivot axis J2. Arm 223 is connected to arm 222 and rotates relative to arm 222 around pivot axis J3. Arm 224 is connected to arm 223 and rotates relative to arm 223 around pivot axis J4. Arm 225 is connected to arm 224 and rotates relative to arm 224 around pivot axis J5. Arm 226 is connected to arm 225 and rotates relative to arm 225 around pivot axis J6.

[0013] In Figure 1, the extension direction of arm 224 is along the Y-axis. Arm 225 is connected to arm 224 on the +Y side. The extension direction of the pivot axis J5 is along the X-axis.

[0014] Robot 2 also has drive mechanisms 231, 232, 233, 234, 235, and 236. Drive mechanism 231 rotates arm 221 around pivot axis J1 relative to base 21. Drive mechanism 232 rotates arm 222 around pivot axis J2 relative to arm 221. Drive mechanism 233 rotates arm 223 around pivot axis J3 relative to arm 222. Drive mechanism 234 rotates arm 224 around pivot axis J4 relative to arm 223. Drive mechanism 235 rotates arm 225 around pivot axis J5 relative to arm 224. Drive mechanism 236 rotates arm 226 around pivot axis J6 relative to arm 225.

[0015] The controller 20 independently controls the drive mechanisms 231 to 236 to cause the robot 2 to perform a predetermined operation. The controller 20 is composed of, for example, a computer and includes a processor that processes information, a memory communicably connected to the processor, and an external interface. Also, various programs executable by the processor are stored in the memory, and the processor can read and execute the various programs and the like stored in the memory.

[0016] Next, the drive mechanism 235 will be described. The drive mechanism 235 is an example of the drive mechanisms of the robot 2.

[0017] The tip of the arm 224 is bifurcated. Of the two branches, the +X side is the first tip 224a and the -X side is the second tip 224b. The arm 225 is supported in a both-side manner from both sides in the direction in which the rotation axis J5 extends by the first tip 224a and the second tip 224b. By supporting the arm 225 in a both-side manner like this, the rotation accuracy of the arm 225 can be improved.

[0018] FIG. 2 is a cross-sectional view showing the inside of the robot 2 according to the first embodiment. FIG. 2 shows the drive mechanism 235 and its periphery in FIG. 1 as viewed from the +Z direction. FIG. 3 is an enlarged view showing a part of the region B in FIG. 2. In the posture of the robot 2 in FIG. 1, the x-axis is parallel to the X-axis, the y-axis is parallel to the Y-axis, and the z-axis is parallel to the Z-axis.

[0019] The drive mechanism 235 includes a pulley 27, an input member 28, a speed reducer 29, and a bearing 30 that supports the input member 28. A part of the drive mechanism 235 is provided at the first tip 224a, and another part of the drive mechanism 235 is provided on the arm 225. The speed reducer 229 is provided outside the arm 224.

[0020] The first tip portion 224a has a housing 24 and a cover 25 attached to the housing 24 as an exterior. The housing 24 faces the arm 225 and is located between the cover 25 and the arm 225. The space S partitioned by the housing 24 and the cover 25 is part of the interior of the arm 224.

[0021] Arm 224 has an internal motor (not shown) that generates a driving force. The driving force is transmitted to the drive mechanism 235 via a rotating belt 26.

[0022] The housing 24 has a through hole 31 that penetrates along the pivot axis J5. The through hole 31 includes a recess 32 on the side facing the reduction gear 29. The recess 32 is cylindrical with respect to the pivot axis J5 and opens towards the reduction gear 29. The bottom portion 32a of the recess 32 has a hole 33, which is part of the through hole 31.

[0023] The housing 24 has an inclined portion 35. The inclined portion 35 is a conical tapered surface with its apex at the -x side of the pivot axis J5 on the +x side of the through hole 31. The inclined portion 35 is inclined with respect to the yz plane. As the inclined portion 35 moves away from the input member 28 in the y-axis direction or z-axis direction, which is the radial direction of the through hole 31, it is inclined in a direction away from the reduction gear 29. That is, in Figure 3, as the inclined portion 35 moves away from the input member 28 on the -y side, it is inclined in a direction away from the reduction gear 29 in the +x direction. The yz plane corresponds to a virtual plane perpendicular to the axis of the input member 28. The axis of the input member 28 coincides with the pivot axis J5.

[0024] The inclined portion 35 is arranged in a ring shape around the through hole 31. The -x side end of the inclined portion 35 is connected to the +x side edge 31a of the through hole 31. In other words, the inclined portion 35 is provided continuously from the through hole 31.

[0025] A bearing 30 is positioned in the recess 32. The bearing 30 has an outer ring 40 and an inner ring 41 as raceways, and balls 42 as rolling elements. The rotation axis Js of the bearing 30 coincides with the pivot axis J5. The outer ring 40 is in contact with the bottom 32a and side surface 32b of the recess 32. That is, in a plan view from the x-axis direction, the inclined portion 35 and the outer ring 40 overlap in part.

[0026] The input member 28 is a rod-shaped object extending along the pivot axis J5. The input member 28 is inserted through the through hole 31 and the inner ring 41 of the bearing 30. The bearing 30 supports the input member 28 so that it can rotate around its axis. The input member 28 is a shaft with sections of different diameters, a so-called stepped shaft. The central axis of the input member 28 coincides with the pivot axis J5.

[0027] The pulley 27 is fixed to the +x end of the input member 28. The pulley 27 receives driving force from the motor via the rotating belt 26. The input member 28 is connected to the reduction gear 29 on the -x side of the bearing 30. The driving force received by the pulley 27 is transmitted to the reduction gear 29 via the input member 28. The input member 28 inputs driving force to the reduction gear 29.

[0028] The reduction gear 29 receives driving force from the input member 28. The reduction gear 29 reduces the driving force received from the input member 28 and outputs it from the output shaft. The output shaft is fixed to the arm 225. The arm 225 receives the driving force output from the reduction gear 29. The arm 225 rotates relative to the arm 224 due to the driving force received from the reduction gear 29.

[0029] The gear reducer 29 reduces the input rotation by meshing multiple gears. The gear reducer 29 contains grease (not shown) as a lubricant inside. The grease suppresses frictional loss between the gears, resulting in smooth operation and reduced heat generation.

[0030] In this embodiment, the gearbox 29 includes a wave generator 44, a flexspline 45, and a circular spline 46. The wave generator 44 is an elliptical cam and is positioned inside the flexspline 45. The wave generator 44 is fixed to the input member and rotates together with the input member. The flexspline 45 is flexible and has external teeth on its outer circumference. The flexspline 45 is fixed to the output shaft of the arm 225 on the -x side. The circular spline 46 is fixed to the housing 24 and has internal teeth. The external teeth of the flexspline 45 and the internal teeth of the circular spline 46 face each other around the axis of the input member and mesh at two points on the gear, respectively.

[0031] As the wave generator 44 rotates, the meshing position of the external and internal teeth shifts, and the flexspline 45 rotates at a reduced speed. As the flexspline 45 rotates, the arm 225 rotates around the pivot axis J5 relative to the arm 224. The reduction gear 29 is a so-called wave drive gear reducer. Thus, the reduction gear 29 is located on the outside of the arm 224. Grease is placed inside the flexspline 45.

[0032] Robot 2 has a sheet 50 on the +x side of the housing 24, that is, on the side of the housing 24 opposite to the reduction gear 29. The sheet 50 is made of felt. The sheet 50 is arranged in an annular shape surrounding the inclined portion 35. That is, the sheet 50 is located around the through hole 31.

[0033] The sheet 50 has two main surfaces that are in a front-to-back relationship with each other in the x-axis direction. The main surface on the -x side is bonded to the housing 24, and the main surface on the +x side 51 is exposed to the space S. The +x end of the inclined portion 35 is adjacent to or in contact with the side surface 52 of the sheet 50 on the rotation axis Js side. That is, the inclined portion 35 is inclined in the direction from the edge 31a of the through hole 31 toward the sheet 50.

[0034] The portion of the housing 24 where the sheet 50 is located is an annular recess 53 surrounding the through hole 31.

[0035] The inner circumferential surface 54 of the recess 53 is connected to the +x side end of the inclined portion 35. That is, the inner circumferential surface 54 is provided continuously from the +x side end of the inclined portion 35. The main surface 51 is located on the +x side of the +x side end of the inclined portion 35.

[0036] Next, the functions of the inclined section 35 and the sheet 50 will be explained using Figure 4. Figure 4 is a cross-sectional view of the robot 2 when its posture changes from Figure 3 so that the +x direction in Figure 3 is vertically downward. In Figure 4, the housing 24 is located vertically downward, i.e., on the -Z side, relative to the reduction gear 29 (not shown in this figure). At this time, the grease in the reduction gear 29 may leak out through the through hole 31 to the inside of the arm 224, i.e., to the space S side. As shown in Figure 4, the leaked grease G adheres to the inclined section 35 due to surface tension and is guided in the direction of arrow 60 by gravity. The direction of arrow 60 is from the through hole 31 toward the sheet 50. Furthermore, when the input member 28 rotates around its axis, centrifugal force is generated in the grease G. In this case, the guidance of the grease G is promoted by the resultant force of centrifugal force and gravity.

[0037] When the grease G reaches the sheet 50, it is absorbed by the sheet 50. Therefore, the sheet 50 is an absorbent member that absorbs the leaked grease G. In addition, the inclined portion 35 functions as a guide portion that guides the grease G.

[0038] With this configuration, if the grease contained in the reduction gear 29 leaks out through the through hole 31, the grease G is guided along the inclined section 35 to the sheet 50. Therefore, it is possible to prevent the leaked grease G from scattering inside the robot 2.

[0039] As a result, there is no need to provide an oil seal on the input member 28 on the housing 24 side of the reduction gear 29. In other words, the arm 224 does not have an oil seal to seal the space between the housing 24 and the input member 28. Therefore, it is possible to prevent an increase in frictional resistance during the rotation of the input member 28 relative to the housing 24. As a result, the torque loss in the motor that generates the driving force can be reduced. This makes it possible to provide a vertical articulated robot with low power consumption. In addition, by not having an oil seal, the axial length of the input member 28 can be shortened. Therefore, a compact vertical articulated robot can be realized.

[0040] Furthermore, in this embodiment, unlike the vertical articulated robot disclosed in Patent Document 1, it is not necessary to provide multiple sheets 50. Therefore, the number of sheets 50 can be minimized.

[0041] Furthermore, in this embodiment, the fit between the bearing 30 and the input member 28 is an interference fit. The method of attaching the bearing 30 to the input member 28 is not particularly limited, but for example, it is press-fit. With this configuration, it is possible to reduce the leakage of grease from the gap between the inner ring 41 and the input member 28.

[0042] Furthermore, as shown in Figure 3, the bearing 30 is a sealed bearing having a seal 43. The seal 43 is annular and is positioned on both sides of the ball 42 in a direction along the rotation axis Js. This configuration reduces the leakage of grease G from between the inner ring 41 and the outer ring 40. Therefore, the leaked grease G can be efficiently guided from between the outer ring 40 and the recess 32 of the bearing 30 to the inclined portion 35. Thus, the grease G can be guided to the seat 50 more reliably.

[0043] Furthermore, since air leaks from inside the reducer 29 through the gap between the bearing 30 and the recess 32, it is possible to prevent an increase in the internal pressure inside the reducer 29. This eliminates the need to provide, for example, a hole in the input member 28 to connect the inside and outside of the reducer 29. Thus, it becomes possible to provide a low-cost vertical articulated robot.

[0044] Furthermore, the sheet 50 is not limited to being made of felt, but may be made of recycled fibers. This makes it possible to provide a vertical articulated robot with a reduced environmental impact.

[0045] Furthermore, the drive mechanism in this embodiment is not particularly limited to drive mechanism 235. The drive mechanism in this embodiment may be any of drive mechanisms 231, 232, 233, 234, or 236, or all of drive mechanisms 231 to 236. Also, if the drive mechanism in this embodiment is drive mechanism 231 or drive mechanism 234, the reduction gear 29 may be of a hollow type, and the input member may be a hollow wave generator integrated with the wave generator of the reduction gear 29.

[0046] 2. Modified form of the first embodiment A modified example of the first embodiment will be described using Figures 5A and 5B. Figure 5A is a view of the inclined portion 35 according to the modified example of the first embodiment, as seen from the +x side. Figure 5B is a cross-sectional view taken along line BB in Figure 5A. In Figures 5A and 5B, components similar to those in the previously described embodiment are denoted by the same reference numerals. Also, in Figures 5A and 5B, the input member 28 is shown in a state with the input member 28 removed. The explanation will focus on the differences from the first embodiment, and similar matters will be omitted from the explanation. The difference between this modified example and the first embodiment is that the inclined portion 35 is provided on a part of the circumferential direction centered on the axis of the input member 28; otherwise, it is the same.

[0047] The housing 24 has a through hole 31, a recess 53 around the through hole 31 where the sheet 50 is positioned, and an inclined portion 35. The surface 55 connecting the opening-side end 54a of the inner circumferential surface 54 of the recess 53 and the edge 31c of the through hole 31 is parallel to the yz plane and annular. The portion formed by the inner circumferential surface 54, the connecting surface 55, and the +x-side end of the through hole 31 is a guide portion 56 that defines the position of the sheet 50. The guide portion 56 protrudes from the edge 31b of the through hole 31 in the axial direction of the input member 28, i.e., towards the +x side.

[0048] The inclined portion 35 is provided on a part of the circumferential direction of the input member 28 of the guide portion 56, centered on the axis. Specifically, when viewed from the +x axis direction, there are four inclined portions 35, each positioned to divide the circumferential direction into four equal parts. The inclined portion 35 is provided between the edge 31b of the through hole 31 and the sheet 50. The inclined portion 35 is a concave bottom portion in which a part of the connecting surface 55 is cut out.

[0049] This configuration allows the sheet 50 to be attached in alignment with the guide section 56. Therefore, the positioning of the sheet 50 becomes easier.

[0050] The number of inclined sections 35 is not limited to four; for example, there may be one or any number.

[0051] Furthermore, the arrangement of the inclined sections 35 is not particularly limited to being equally spaced in the circumferential direction; the spacing between them can be set as appropriate.

[0052] Furthermore, the total length of the inclined portion 35 in the circumferential direction is not particularly limited. For example, the total length of the inclined portion 35 in the circumferential direction may be greater than or less than the total length of the connecting surface 55 in the circumferential direction.

[0053] 3. Second Embodiment A second embodiment will be described using Figures 6 to 8. Figure 6 is a cross-sectional view showing the inclined portion 35 according to the second embodiment. Figures 7 and 8 are cross-sectional views when the posture of the robot 2 is changed from Figure 6 so that the +x direction in Figure 6 is vertically downward or vertically upward. In Figures 6 to 8, the same reference numerals are used for components that are the same as those in the previously described embodiment. The explanation will focus on the differences from the first embodiment, and similar matters will be omitted from the explanation. The difference between this embodiment and the first embodiment is that the inclined portion 35 includes multiple inclined portions; otherwise, they are the same.

[0054] The housing 24 has a through hole 31, a recess 53 around the through hole 31 in which the sheet 50 is positioned, and an inclined portion 35 between the edge 31a of the through hole 31 and the sheet 50. The inclined portion 35 includes a first inclined portion 36, a second inclined portion 37 located further away from the through hole 31 than the first inclined portion 36, and a connecting portion 39 positioned between the first inclined portion 36 and the second inclined portion 37 and connecting them.

[0055] The first inclined portion 36 is connected to the +x-side edge 31a of the through hole 31 and is arranged in an annular shape around the through hole 31. The connecting portion 39 is connected to the outer circumference of the first inclined portion 36 and is arranged in an annular shape when viewed from the x-axis direction. The second inclined portion 37 is connected to the outer circumference of the connecting portion 39 and is arranged in an annular shape when viewed from the x-axis direction. The outer circumference of the second inclined portion 37 is connected to the inner circumferential surface 54 of the recess 53 when viewed from the x-axis direction.

[0056] The first inclined portion 36 and the second inclined portion 37 are inclined in a direction away from the reduction gear 29 as they move away from the input member 28 in the y-axis direction or z-axis direction, which is the radial direction of the through hole 31. That is, in Figure 6, as they move away from the input member 28 on the -y side, they are inclined in a direction away from the reduction gear 29 in the +x direction. The connecting portion 39 is parallel to the yz plane. That is, the angle at which the connecting portion 39 is inclined with respect to the yz plane is smaller than the angle at which the first inclined portion 36 is inclined with respect to the yz plane, and the angle at which the second inclined portion 37 is inclined with respect to the yz plane. However, the connecting portion 39 may be inclined, but in this case, it is desirable that the angle of inclination be small.

[0057] As shown in Figure 7, when the leaked grease G is in the second inclined section 37, the grease G can be guided in the direction of arrow 61 when arm 224 is positioned vertically below arm 225. The direction of arrow 61 is from the through hole 31 toward the sheet 50.

[0058] On the other hand, as shown in Figure 8, when the leaked grease G is in the first inclined section 36, when the arm 224 is positioned vertically above the arm 225, the grease G can be guided in the direction of arrow 62 and returned to the bearing 30 side. The direction of arrow 62 is the opposite direction to that of arrow 61. With this configuration, the discharge direction can be changed depending on the position of the grease G.

[0059] 4. Third Embodiment A third embodiment will be described using Figures 9 to 11. Figure 9 is a cross-sectional view showing the inclined section 35 according to the third embodiment. Figures 10 and 11 are cross-sectional views when the posture of the robot 2 changes from Figure 9 so that the +x direction in Figure 9 becomes vertically upward. In Figures 9 to 11, the same reference numerals are used for components that are the same as those in the previously described embodiments. The explanation will focus on the differences from the first embodiment, and similar items will be omitted from the explanation. The difference between this embodiment and the previously described embodiments is that the inclined section 35 has multiple inclined sections, and the direction of inclination differs from that of the multiple inclined sections. Otherwise, it is the same as the previously described embodiments.

[0060] The housing 24 has a through hole 31, a recess 53 around the through hole 31 where the sheet 50 is positioned, and an inclined portion 35 between the edge 31a of the through hole 31 and the sheet 50. The inclined portion 35 includes a first inclined portion 36 and a second inclined portion 38 provided at a position further away from the input member 28 than the first inclined portion 36.

[0061] The first inclined portion 36 is connected to the +x-side edge 31a of the through hole 31 and is arranged in an annular shape around the through hole 31. The second inclined portion 38 is connected to the outer circumference of the first inclined portion 36 and is arranged in an annular shape when viewed from the x-axis direction. The outer circumference of the second inclined portion 38 is connected to the inner circumferential surface 54 of the recess 53 when viewed from the x-axis direction.

[0062] The first inclined portion 36 is inclined in a direction away from the reduction gear 29 as it moves away from the input member 28 in the y-axis direction or z-axis direction, which are the radial directions of the through hole 31. That is, in Figure 9, as it moves away from the input member 28 on the -y side, it is inclined in a direction away from the reduction gear 29 in the +x direction. The second inclined portion 38 is inclined in the -x direction, that is, as it moves away from the input member 28, it is in a direction closer to the reduction gear 29.

[0063] As shown in Figure 10, when the leaked grease G is in the second inclined section 38, the grease G can be guided in the direction of arrow 63 when the arm 224 is positioned vertically above the arm 225. The direction of arrow 63 is from the connection between the first inclined section 36 and the second inclined section 38 toward the seat 50.

[0064] On the other hand, as shown in Figure 11, when the leaked grease G is in the first inclined section 36, when the arm 224 is positioned vertically above the arm 225, the grease G can be guided in the direction of arrow 64 and returned to the bearing 30. The direction of arrow 64 is from the connection between the first inclined section 36 and the second inclined section 38 toward the bearing 30. With this configuration, the discharge direction can be changed depending on the position of the grease G.

[0065] The embodiments of the vertical articulated robot have been described above with reference to the figures, but the embodiments are not limited to these, and the configuration of each part can be replaced with any configuration having a similar function. In addition, other arbitrary components may be added to these embodiments. Furthermore, each embodiment may be combined as appropriate. [Explanation of Symbols]

[0066] 1…Robot system, 2…Robot, 20…Controller, 21…Base, 22…Robot arm, 24…Housing, 25…Cover, 26…Rotating belt, 27…Pulley, 28…Input member, 29…Gear reducer, 30…Bearing, 31…Through hole, 31a, 31b, 31c…Edge, 32…Recess, 32a…Bottom, 32b…Side, 33…Hole, 35…Inclined section, 36…First inclined section, 37…Second inclined section, 38…Second inclined section, 39…Connecting section, 40…Outer ring 41...Inner ring, 42...Ball, 43...Seal, 44...Wave generator, 45...Flex spline, 46...Circular spline, 50...Seat, 51...Main surface, 52...Side surface, 53...Recess, 54...Inner circumferential surface, 54a...End, 55...Connecting surface, 56...Guide part, 60~64...Arrow, 221~226...Arm, 224a...First tip, 224b...Second tip, 231~236...Drive mechanism, G...Grease, J1~J6...Rotating shaft, S...Space

Claims

1. An arm having a housing with a through hole including a recess, A reduction gear provided on the outside of the aforementioned arm and containing a lubricant, An input member inserted through the through hole and inputting driving force to the reduction gear, A bearing is disposed in the recess and supports the input member so that it can rotate around its axis, On the side of the housing opposite to the reduction gear, an absorbing member is arranged around the through hole to absorb the lubricant, A vertical articulated robot characterized in that the housing has an inclined portion between the edge of the through hole and the absorbent member.

2. The housing has a guide portion that protrudes in the axial direction of the input member at the edge of the through hole, The vertical articulated robot according to claim 1, wherein the inclined portion is provided in the guide portion on a part of the circumferential direction of the input member.

3. The inclined portion includes a first inclined portion, a second inclined portion provided at a position further away from the input member than the first inclined portion, and a connecting portion connecting the first inclined portion and the second inclined portion. The first inclined portion and the second inclined portion are inclined in a direction away from the reduction gear as they move away from the input member. The vertical articulated robot according to claim 1 or 2, wherein the angle at which the connection portion is inclined with respect to a virtual plane perpendicular to the axis of the input member is smaller than the angle at which the first inclined portion and the second inclined portion are inclined with respect to a virtual plane perpendicular to the axis.

4. The inclined portion includes a first inclined portion and a second inclined portion provided at a position further away from the input member than the first inclined portion. The first inclined portion is inclined in a direction away from the reduction gear as it moves away from the input member. The vertical articulated robot according to claim 1 or 2, wherein the second inclined portion is inclined in a direction that moves closer to the reduction gear as it moves away from the input member.

5. The vertical articulated robot according to claim 1 or 2, wherein the bearing is a sealed bearing and is press-fitted to the input member.

6. A vertical articulated robot according to claim 1 or 2, which does not have an oil seal for sealing the space between the housing and the input member.

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