robot

Abstract

The present application provides a driving mechanism and a robot, which can inhibit the fourth belt wheel from being large-sized and achieve a large reduction ratio. The driving mechanism has: a first belt wheel rotating around a first shaft; a motor rotating the first belt wheel around the first shaft; a second belt wheel arranged separately from the first belt wheel and rotating around a second shaft parallel to the first shaft; a first belt hanging around the first and second belt wheels and transmitting power of the motor from the first belt wheel to the second belt wheel; a third belt wheel arranged in line with the second belt wheel in a direction along the second shaft and rotating around the second shaft integrally with the second belt wheel; a fourth belt wheel arranged separately from the third belt wheel and rotating around a third shaft parallel to the second shaft; a second belt hanging around the third and fourth belt wheels and transmitting power of the motor from the third belt wheel to the fourth belt wheel; and a first bearing located between the second and third belt wheels and supporting the second and third belt wheels.

Description

[0001] This application is a divisional application of the patent application with application number 202210096580.3, titled "Drive mechanism and robot", and filed on January 26, 2022. TECHNICAL FIELD

[0002] The present application relates to a drive mechanism and a robot. BACKGROUND

[0003] For example, Patent Literature 1 describes a SCARA robot having a drive mechanism that includes a first pulley fixed to a rotating shaft of a direct motor, a ball screw fixed to a spline shaft, a second pulley fixed to the ball screw, and a belt wound around the first pulley and the second pulley. In such a SCARA robot, when the rotating shaft of the direct motor rotates, the rotational driving force of the first pulley is transmitted to the second pulley via the belt, and the spline shaft rotates.

[0004] Patent Literature 1: Japanese Patent Application Publication No. 2019-118978

[0005] However, in the drive mechanism configured in this way, in a case where it is desired to greatly decelerate the rotational speed of the ball screw with respect to the rotational speed of the rotating shaft of the direct motor, it is necessary to increase the pulley ratio of the first pulley to the second pulley, and thus there is a technical problem in that the diameter of the second pulley becomes large, and accordingly, the front end portion of the SCARA robot becomes hypertrophied. SUMMARY

[0006] The drive mechanism of the present application has: a first pulley that rotates around a first shaft;

[0007] a motor that rotates the first pulley around the first shaft;

[0008] a second pulley that is arranged separately from the first pulley and rotates around a second shaft that is parallel to the first shaft;

[0009] a first belt that is wound around the first pulley and the second pulley and transmits the power of the motor from the first pulley to the second pulley;

[0010] a third pulley that is arranged in line with the second pulley in a direction along the second shaft and rotates around the second shaft integrally with the second pulley;

[0011] a fourth pulley that is arranged separately from the third pulley and rotates around a third shaft that is parallel to the second shaft;

[0012] a second belt that is wound around the third pulley and the fourth pulley and transmits the power of the motor from the third pulley to the fourth pulley; and

[0013] A first bearing is located between the second pulley and the third pulley and supports the second pulley and the third pulley.

[0014] The robot of the present application has the above-described drive mechanism. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a side view showing the overall configuration of a robot according to a first embodiment.

[0016] Figure 2 is a plan view showing the internal structure of a second arm possessed by the robot of Figure 1

[0017] Figure 3 is a sectional view showing a drive mechanism possessed by the second arm of Figure 2

[0018] Figure 4 is a sectional view showing a drive mechanism possessed by a robot according to a second embodiment.

[0019] Figure 5 is a sectional view showing a drive mechanism possessed by a robot according to a third embodiment.

[0020] Figure 6 is a sectional view showing a drive mechanism possessed by a robot according to a fourth embodiment.

[0021] BRIEF DESCRIPTION OF DRAWINGS

[0022] 100: robot; 110: base; 120: arm; 130: first arm; 140: second arm; 141: housing; 150: work head; 151: spline nut; 152: ball screw nut; 153: spline shaft; 160: end effector; 171: joint actuator; 172: joint actuator; 181: drive mechanism; 182: drive mechanism; 190: robot control device; 2: motor; 21: output shaft; 31: first pulley; 32: second pulley; 33: third pulley; 34: fourth pulley; 41: first belt; 42: second belt; 51: first speed reducer; 52: second speed reducer; 61: first bearing; 611: inner ring; 612: outer ring; 613: ball; 62: second bearing; 621: inner ring; 622: outer ring; 623: ball; 7: shaft portion; 8: link portion; 81: first bearing support portion; 82: second bearing support portion; 83: connection portion; 9: brake; J1: first rotation axis; J2: second rotation axis; J3: third rotation axis; JJ1: first shaft; JJ2: second shaft; JJ3: third shaft. DETAILED DESCRIPTION

[0023] ​​Next, the driving mechanism and the robot according to the present application will be described in detail based on the embodiments shown in the drawings.

[0024] Further, for convenience of explanation, the X-axis, the Y-axis, and the Z-axis are illustrated as three axes orthogonal to each other in each drawing. In addition, hereinafter, the upper side of each drawing, that is, the arrow side of the Z-axis is set as the upper side in the vertical direction, and the lower side of each drawing, that is, the side opposite to the arrow of the Z-axis is set as the lower side in the vertical direction. Note that the meaning of "parallel" in the present application includes a state slightly deviated from parallel, in addition to the case of parallel. That is, the meaning thereof also includes a state regarded as the same as parallel in technical common sense. Similarly, the meaning of "orthogonal" in the present application includes a state slightly deviated from orthogonal, in addition to the case of orthogonal. That is, the meaning thereof also includes a state regarded as the same as orthogonal in technical common sense.

[0025] First Embodiment

[0026] Figure 1 is a side view showing the overall configuration of the robot according to the first embodiment. Figure 2 is a plan view showing the internal structure of the second arm possessed by the robot of Figure 1 Figure 3 is a plan view showing the internal structure of the second arm possessed by the robot of Figure 2

[0027] Figure 1 The robot 100 shown in FIG. 1 is an SCARA robot, for example, used in each work such as holding, conveying, assembling, and inspecting of workpieces such as electronic parts. However, the use of the robot 100 is not particularly limited.

[0028] The robot 100 has a base 110 fixed to the floor and an arm 120 connected to the base 110. In addition, the arm 120 has a first arm 130 having a base end portion connected to the base 110, the first arm 130 being rotatable relative to the base 110 about a first rotation axis J1 along the vertical direction, and a second arm 140 having a base end portion connected to a front end portion of the first arm 130, the second arm 140 being rotatable relative to the first arm 130 about a second rotation axis J2 along the vertical direction. The first rotation axis J1 is parallel to the second rotation axis J2.

[0029] ​​Further, a work head 150 is provided at the front end portion of the second arm 140. The work head 150 has a spline nut 151 and a ball screw nut 152 which are coaxially arranged at the front end portion of the second arm 140, and a spline shaft 153 which is inserted through the spline nut 151 and the ball screw nut 152. The spline shaft 153 is rotatable with respect to the second arm 140 about a third rotation axis J3 which is a central axis in the vertical direction, and is vertically movable along the third rotation axis J3. The third rotation axis J3 is parallel to the first rotation axis Jl and the second rotation axis J2.

[0030] However, the work head 150 is not particularly limited. For example, it can be configured such that two shafts are provided, one of which is rotatable about the third rotation axis J3 and the other of which is vertically movable in the axial direction parallel to the third rotation axis J3.

[0031] Further, an end effector 160 is attached to the lower end portion of the spline shaft 153. The end effector 160 can be appropriately selected from among end effectors which are detachable and suitable for a target work. As the end effector 160, for example, a hand which holds a workpiece by gripping or suction, a work tool which performs a predetermined process on a workpiece, or the like can be cited.

[0032] Further, the robot 100 has a joint actuator 171 which links the base 110 and the first arm 130 and rotates the first arm 130 about the first rotation axis Jl with respect to the base 110, and a joint actuator 172 which links the first arm 130 and the second arm 140 and rotates the second arm 140 about the second rotation axis J2 with respect to the first arm 130. Further, the robot 100 has a drive mechanism 181 which rotates the spline nut 151 to rotate the spline shaft 153 about the third rotation axis J3, and a drive mechanism 182 which rotates the ball screw nut 152 to vertically move the spline shaft 153 in the direction along the third rotation axis J3.

[0033] Further, the robot 100 has a robot control device 190 which is arranged in the base 110 and controls the driving of the joint actuators 171, 172 and the drive mechanisms 181, 182 based on an instruction from a host computer not shown. The robot control device 190 independently controls the joint actuators 171, 172 and the drive mechanisms 181, 182, respectively, so that the robot 100 can perform a desired work. The robot control device 190 has, for example, a processor constituted by a computer and processing information, a memory communicably connected to the processor, and an external interface. Further, various programs executable by the processor are stored in the memory, and the processor can read and execute various programs stored in the memory, and the like.

[0034] The overall configuration of the robot 100 has been described above. Next, the operation of the robot 100 will be described based on the configuration described above. Figure 2 andFigure 3 The drive mechanism 181 that rotates the spline nut 151 and causes the spline shaft 153 to rotate about the third rotation axis J3 will be described in detail.

[0035] like Figure 2 and Figure 3 As shown, the drive mechanism 181 has a motor 2 as a drive source. The motor 2 is fixed to the housing 141 of the second arm 140, and its output shaft 21 rotates about a first axis JJ1 along the vertical direction. The motor 2 is an AC servo motor. However, there is no particular limitation on the type of motor 2, and for example, a DC servo motor, a stepper motor, etc., can also be used.

[0036] Furthermore, the drive mechanism 181 has a first pulley 31 disposed on the output shaft 21 of the motor 2 and rotating integrally with the output shaft 21 around the first shaft JJ1. The lower end of the output shaft 21 is a free end, and the first pulley 31 can be removed from this lower end side. It should be noted that in this embodiment, the first pulley 31 is directly disposed on the output shaft 21, but it is not limited to this. It is also possible that a power transmission mechanism or a reducer, such as a gear, is disposed between them.

[0037] Additionally, the drive mechanism 181 has a second pulley 32 that is separately configured from the first pulley 31 and rotates about a second axis JJ2 parallel to the first axis JJ1. The second pulley 32 is configured relative to the first pulley 31 on the front end side of the second arm 140 and is located between the spline shaft 153 and the first pulley 31. Furthermore, the second pulley 32 and the first pulley 31 are arranged in a direction along the XY plane. However, the configuration of the second pulley 32 is not particularly limited.

[0038] Furthermore, the drive mechanism 181 has a first belt 41 that is wound around and connects the first pulley 31 and the second pulley 32. Therefore, when the first pulley 31 rotates, its rotation is transmitted to the second pulley 32 via the first belt 41, and the second pulley 32 rotates in response to the first pulley 31. The outer diameter of the second pulley 32 is larger than the outer diameter of the first pulley 31. Therefore, the first pulley 31, the first belt 41, and the second pulley 32 constitute a first speed reducer 51 that reduces the rotational speed of the output shaft 21 of the motor 2.

[0039] Additionally, the drive mechanism 181 has a third pulley 33 arranged with the second pulley 32 in the direction along the second axis JJ2 and rotating about the second axis JJ2. The third pulley 33 rotates integrally with the second pulley 32. The outer diameter of the third pulley 33 is smaller than the outer diameter of the second pulley 32.

[0040] Further, the drive mechanism 181 has a fourth pulley 34 that is arranged separately from the third pulley 33 and rotates around a third shaft JJ3 that is parallel to the first shaft JJ1 and the second shaft JJ2. The fourth pulley 34 is arranged on the front end side of the second arm 140 with respect to the third pulley 33 and is arranged coaxially with the spline shaft 153. That is, the third shaft JJ3 coincides with the third turning shaft J3. Further, the spline nut 151 is inserted through and fixed to the fourth pulley 34, and they rotate integrally. Further, the fourth pulley 34 and the third pulley 33 are arranged in the direction along the X-Y plane. However, the arrangement of the fourth pulley 34 is not particularly limited.

[0041] Further, the drive mechanism 181 has a second belt 42 that is hung on the third pulley 33 and the fourth pulley 34 and links them. Thus, when the third pulley 33 rotates, its rotation is transmitted to the fourth pulley 34 via the second belt 42, and the fourth pulley 34 rotates driven by the third pulley 33. The outer diameter of the fourth pulley 34 is larger than that of the third pulley 33. Thus, the third pulley 33, the second belt 42, and the fourth pulley 34 constitute a second speed reducer 52 that reduces the rotational speed of the output shaft 21 of the motor 2.

[0042] Note that, as the configuration of the drive mechanism 181, it is not limited to this, and for example, an idler that applies tension to the second belt 42 can be provided.

[0043] In such a drive mechanism 181, the driving force of the motor 2 is transmitted to the spline nut 151 via the first speed reducer 51 and the second speed reducer 52. As such, by interposing the first speed reducer 51 and the second speed reducer 52 between the motor 2 and the spline nut 151, the spline nut 151 can be caused to rotate at a desired rotational speed. Further, the degree of freedom of arrangement of the motor 2 is improved, and the second arm 140 is easily designed.

[0044] In particular, by arranging two speed reducers between the motor 2 and the spline nut 151, the outer diameter of the fourth pulley 34 can be suppressed to be small compared to the case where one speed reducer is arranged. Thus, the enlargement and weight increase of the front end portion of the second arm 140 can be suppressed, and a robot 100 having excellent driving characteristics can be realized. For example, in the case where it is desired to reduce the rotational speed of the fourth pulley 34 with respect to the output shaft 21 to 1 / 9, in the configuration of the present embodiment, it is sufficient to set the pulley ratio of the first speed reducer 51 to 3 and the pulley ratio of the second speed reducer 52 to 3. Thus, excessive enlargement of the fourth pulley 34 can be suppressed. In contrast, in the case where only the second speed reducer 52 is provided, that is, in the case where the first speed reducer 51 is omitted and the third pulley 33 is arranged on the output shaft 21, it is necessary to set the pulley ratio of the second speed reducer 52 to 9, resulting in excessive enlargement of the fourth pulley 34.

[0045] Further, the drive mechanism 181 has a first bearing 61 disposed between the second pulley 32 and the third pulley 33. Further, the drive mechanism 181 has a second bearing 62 disposed on the lower side of the third pulley 33 in a manner that sandwiches the third pulley 33 between the first bearing 61. That is, on the second shaft JJ2, the second bearing 62, the third pulley 33, the first bearing 61, and the second pulley 32 are arranged in this order from the lower side. The first bearing 61 and the second bearing 62 respectively support the second pulley 32 and the third pulley 33 so as to be rotatable about the second shaft JJ2. The second pulley 32 is cantilevered supported by the first bearing 61 from the lower side, and the third pulley 33 is supported at both ends from the upper and lower sides by the first bearing 61 and the second bearing 62.

[0046] Here, the rotation speed of the output shaft 21 is reduced by the first speed reducer 51, and accordingly, a greater torque than that of the first belt 41 is applied to the second belt 42. Thus, in order to maintain durability, it is necessary to make the rigidity of the second belt 42 greater than that of the first belt 41, and accordingly, the tension of the second belt 42 also becomes greater, and as a result, a greater radial load than that of the second pulley 32 is applied to the third pulley 33. Thus, as in the present embodiment, by supporting the third pulley 33 at both ends by the first bearing 61 and the second bearing 62, it is possible to more effectively suppress displacement of the third pulley 33 due to the radial load described above. Thus, the rotation of the third pulley 33 is stabilized. Further, compared to a case in which the third pulley 33 is cantilevered supported by one bearing, it is also possible to downsize the first bearing 61 and the second bearing 62. However, it is not limited thereto, and the second bearing 62 can be omitted.

[0047] Note that, as the first bearing 61 and the second bearing 62, there is no particular limitation. In the present embodiment, a deep groove ball bearing is used as the first bearing 61 and the second bearing 62. According to the deep groove ball bearing, it is possible to bear a radial load, axial loads in two directions, or a combined load thereof, and it is also possible to cope with high-speed rotation. Further, since it is widely used, it is also possible to realize cost reduction.

[0048] Further, the first bearing 61 has an inner ring 611 and an outer ring 612 disposed concentrically, and a plurality of balls 613 disposed therebetween. Similarly, the second bearing 62 has an inner ring 621 and an outer ring 622 disposed concentrically, and a plurality of balls 623 disposed therebetween. Further, the outer rings 612, 622 of the first bearing 61 and the second bearing 62 are respectively fixed to the housing 141 of the second arm 140, and are inserted into and fixed to the inner rings 611, 621 along the shaft portion 7 of the second shaft JJ2. Also, the second pulley 32 and the third pulley 33 are fixed to this shaft portion 7. With such a configuration, the second pulley 32 and the third pulley 33 are integrally rotatable about the second shaft JJ2.

[0049] Note that the upper end of the shaft portion 7 is a free end. Thus, as described later, the first belt 41 can be removed from the second pulley 32 without being hindered by the shaft portion 7.

[0050] Next, the fixation of the first bearing 61 and the second bearing 62 to the second arm 140 is described. The drive mechanism 181 has a link portion 8 that links the outer rings 612, 622 of the first bearing 61 and the second bearing 62 to each other. Also, the link portion 8 is fixed to the housing 141 of the second arm 140. Thus, the first bearing 61 and the second bearing 62 are commonly fixed to the housing 141 of the second arm 140. According to such a configuration, the fixation of the first bearing 61 and the second bearing 62 to the second arm 140 becomes easy. However, the method of fixation of the first bearing 61 and the second bearing 62 to the second arm 140 is not particularly limited.

[0051] The link portion 8 has a first bearing support portion 81 that supports the outer ring 612 of the first bearing 61, a second bearing support portion 82 that supports the outer ring 622 of the second bearing 62 and is fixed to the housing 141 of the second arm 140, and a connection portion 83 that connects the first bearing support portion 81 and the second bearing support portion 82. Here, the second bearing support portion 82 is formed integrally with the connection portion 83, and the connection portion 83 is threadedly fixed to the first bearing support portion 81. However, the configuration of the link portion 8 is not limited to this, and for example, the first bearing support portion 81, the second bearing support portion 82, and the connection portion 83 can be configured by mutually different members.

[0052] In addition, the connection portion 83 connects the first bearing support portion 81 and the second bearing support portion 82 by passing through the inside of the second belt 42 that is looped around the third pulley 33 and the fourth pulley 34. That is, the link portion 8 links the first bearing 61 and the second bearing 62 by passing through the inside of the second belt 42.

[0053] The configuration of the drive mechanism 181 is described above. According to the drive mechanism 181, the attachment and detachment of the first belt 41 can be easily performed at the time of repair, maintenance, inspection, and the like. Specifically, by detaching the first pulley 31 from the output shaft 21, the first belt 41 is loosened, and the first belt 41 can be detached from the first pulley 31 and the second pulley 32. At the time of attachment, the reverse procedure is performed, and after the first belt 41 is looped around the first pulley 31 and the second pulley 32, the first pulley 31 is fixed to the output shaft 21. As such, according to the drive mechanism 181, the attachment and detachment of the first belt 41 can be performed by attaching and detaching only the first pulley 31. Thus, the attachment and detachment of the first belt 41 becomes easy.

[0054] In addition, by detaching the work head 150 from the second arm 140 and releasing the fourth pulley 34, the second belt 42 can be detached from the third pulley 33 and the fourth pulley 34. At the time of attachment, the reverse procedure is performed, and after the second belt 42 is wound around the third pulley 33 and the fourth pulley 34, the work head 150 is inserted and fixed to the housing 141 of the second arm 140. In this way, according to the drive mechanism 181, the attachment and detachment of the second belt 42 can be performed by attaching and detaching the work head 150 alone. Thus, the attachment and detachment of the second belt 42 becomes easy. In particular, in the present embodiment, the link portion 8 links the first bearing 61 and the second bearing 62 through the inside of the second belt 42. Thus, the detachment of the second belt 42 is not hindered by the link portion 8, and the second belt 42 can be smoothly detached.

[0055] In addition, for example, in the case where a idler that applies tension to the second belt 42 is provided, by releasing the idler, the second belt 42 can be detached from the third pulley 33 and the fourth pulley 34 without detaching the work head 150.

[0056] Here, once the belt is released, tension needs to be applied again at the time of reattachment, and this operation is troublesome. Thus, in the case where the second belt 42 needs to be detached in order to detach the first belt 41, the operation of applying tension to the first belt 41 and the second belt 42 again is required, and much effort is consumed. The same is true in the case where the first belt 41 needs to be detached in order to detach the second belt 42. In contrast, in the drive mechanism 181, neither the second belt 42 needs to be detached in order to detach the first belt 41, nor the first belt 41 needs to be detached in order to detach the second belt 42. Thus, the trouble of the operation of applying tension again at the time of reattachment of the belt is reduced.

[0057] The above describes the robot 100. As described above, the drive mechanism 181 included in such a robot 100 has the first pulley 31 that rotates around the first shaft JJ1, the motor 2 that rotates the first pulley 31 around the first shaft JJ1, the second pulley 32 that is arranged separately from the first pulley 31 and rotates around the second shaft JJ2 that is parallel to the first shaft JJ1, the first belt 41 that transmits the power of the motor 2 from the first pulley 31 to the second pulley 32 by being hung on the first pulley 31 and the second pulley 32, the third pulley 33 that is arranged in line with the second pulley 32 in the direction along the second shaft JJ2 and rotates around the second shaft JJ2 integrally with the second pulley 32, the fourth pulley 34 that is arranged separately from the third pulley 33 and rotates around the third shaft JJ3 that is parallel to the second shaft JJ2, the second belt 42 that transmits the power of the motor 2 from the third pulley 33 to the fourth pulley 34 by being hung on the third pulley 33 and the fourth pulley 34, and the first bearing 61 that is located between the second pulley 32 and the third pulley 33 and supports the second pulley 32 and the third pulley 33. According to such a configuration, even in a case where a large reduction ratio is desired, it is possible to suppress the outer diameter of the fourth pulley 34 to be small. Thus, it is possible to suppress the enlargement and weight increase of the front end portion of the second arm 140, and it is possible to realize a robot 100 having excellent drive characteristics. In addition, neither the second belt 42 nor the first belt 41 needs to be removed in order to remove the other. Therefore, the removal of the first belt 41 becomes easy. In addition, the trouble of reapplying tension to the belt when reinstalling the belt is reduced.

[0058] In addition, as described above, the drive mechanism 181 has the second bearing 62 that is arranged so as to sandwich the third pulley 33 between the first bearing 61 and supports the third pulley 33. Thereby, the third pulley 33 is supported at both ends by the first bearing 61 and the second bearing 62. Thus, it is possible to more effectively suppress the displacement of the third pulley 33 caused by the tension of the second belt 42, and the rotation of the third pulley 33 is stabilized. In addition, it is possible to downsize the first bearing 61 and the second bearing 62 compared to a case where the third pulley 33 is cantilevered supported by only the first bearing 61.

[0059] In addition, as described above, the drive mechanism 181 has the linking portion 8 that links the first bearing 61 and the second bearing 62 through the inside of the second belt 42. Thereby, the removal of the second belt 42 can be performed without being hindered by the linking portion 8.

[0060] In addition, as described above, the robot 100 has the drive mechanism 181. Thus, the robot 100 can enjoy the effects of the drive mechanism 181, and can exhibit high maintainability.

[0061] Second Embodiment

[0062] In addition, as described above, the drive mechanism 181 has the linking portion 8 that links the first bearing 61 and the second bearing 62 through the inside of the second belt 42. Thereby, the removal of the second belt 42 can be performed without being hindered by the linking portion 8.Figure 4 is a sectional view showing a drive mechanism that the robot according to the second embodiment has.

[0063] In the robot 100 according to the present embodiment, the configuration of the second bearing 62 and the constitution of the link portion 8 are different from those of the robot 100 according to the first embodiment described above, and the rest are the same as those of the robot 100 according to the first embodiment described above. Note that, in the following description, the present embodiment will be described focusing on the points of difference from the above-described embodiments, and the description of the same matters will be omitted. Also, in the following description, the same reference numerals will be attached to the same constitutions as those of the above-described embodiments. Figure 4

[0064] As shown in FIG. 18, in the drive mechanism 181 according to the present embodiment, the second bearing 62 is disposed on the upper side of the second pulley 32 so as to sandwich the second pulley 32 between the first bearing 61 and the second bearing 62. Thus, the second pulley 32 is supported at both ends from above and below by the first bearing 61 and the second bearing 62, and the third pulley 33 is cantilevered supported from the upper side by the first bearing 61. According to such a constitution, the second pulley 32 can be supported in a more stable posture, and the rotation of the second pulley 32 is stabilized. Also, the first bearing 61 and the second bearing 62 can be downsized compared to the case where the second pulley 32 is cantilevered supported by the first bearing 61 alone. Figure 4

[0065] Also, the link portion 8 has a first bearing support portion 81 that supports the outer ring 612 of the first bearing 61 and is fixed to the housing 141 of the second arm 140, a second bearing support portion 82 that supports the outer ring 622 of the second bearing 62, and a connection portion 83 that connects the first bearing support portion 81 and the second bearing support portion 82. Here, the first bearing support portion 81 is formed integrally with the connection portion 83, and the connection portion 83 is threadedly fixed to the second bearing support portion 82. However, the constitution of the link portion 8 is not limited thereto.

[0066] Also, the connection portion 83 passes through the inside of the first belt 41 that is looped around the first pulley 31 and the second pulley 32 to connect the first bearing support portion 81 and the second bearing support portion 82. That is, the link portion 8 links the first bearing 61 and the second bearing 62 by passing through the inside of the first belt 41. Thus, the work of removing the first belt 41 from the first pulley 31 and the second pulley 32 by removing the first pulley 31 from the output shaft 21 is not hindered by the link portion 8, and the work can be smoothly performed.

[0067] ​​As described above, in the drive mechanism 181 of the present embodiment, the second bearing 62 is provided as described above, and the second bearing 62 supports the second pulley 32 in a manner of sandwiching the second pulley 32 between the first bearing 61. Thus, the second pulley 32 is supported at both ends by the first bearing 61 and the second bearing 62. Thus, the rotation of the second pulley 32 is more stable. In addition, the first bearing 61 and the second bearing 62 can be downsized compared to a case in which the second pulley 32 is cantilevered supported by only the first bearing 61.

[0068] In addition, as described above, the drive mechanism 181 has the linking portion 8 that links the first bearing 61 and the second bearing 62 through the inside of the first belt 41. Thus, the attachment and detachment of the first belt 41 can be performed without being hindered by the linking portion 8.

[0069] The same effects as those of the above-described first embodiment can be also obtained by the second embodiment.

[0070] Third Embodiment

[0071] Figure 5 is a cross-sectional view illustrating a drive mechanism that a robot related to the third embodiment has.

[0072] In the robot 100 of the present embodiment, the drive mechanism 181 has the brake 9 in addition to the above, and the rest is the same as the robot 100 of the above-described first embodiment. Note that, in the following description, the present embodiment is described focusing on the points of difference from the above-described embodiments, and the description of the same matters is omitted. In addition, in the following description, the same reference numerals are attached to the same configurations as those of the above-described embodiments. Figure 5 In the following description, the same reference numerals are attached to the same configurations as those of the above-described embodiments.

[0073] As shown in Figure 5 , the drive mechanism 181 of the present embodiment has the brake 9 that restricts the rotation of each of the pulleys 31, 32, 33, 34. The brake 9 is provided to the shaft portion 7, and restricts the rotation of each of the pulleys 31, 32, 33, 34 by restricting the rotation of the shaft portion 7. As the brake 9, there is no particular limitation as long as it can be switched between a state of restricting the rotation of the shaft portion 7 and a state of allowing the rotation of the shaft portion 7.

[0074] In particular, the brake 9 is provided on the lower side of the second bearing 62. Thus, for example, compared to a case in which the brake 9 is provided on the upper side of the second pulley 32, the brake 9 can be provided in the vicinity of the bearing because there is no member interposed therebetween. Thus, the rotation of the shaft portion 7 can be stably restricted by the brake 9. In addition, by providing the brake 9 on the lower side of the second bearing 62, the attachment and detachment of the first belt 41 is hardly affected.

[0075] The same effects as those of the first embodiment described above can be obtained by the third embodiment.

[0076] Fourth Embodiment

[0077] Figure 6 is a cross-sectional view showing a drive mechanism that the robot according to the fourth embodiment has.

[0078] In the robot 100 of the present embodiment, the drive mechanism 181 has a brake 9 in addition to the above, and the rest is the same as the robot 100 of the second embodiment described above. Note that, in the following description, the present embodiment will be described focusing on the points of difference from the above-described embodiments, and the description of the same matters will be omitted. Also, in the following description, the same reference numerals will be attached to the same components as those of the above-described embodiments. Figure 6

[0079] As shown in Figure 6 , the drive mechanism 181 of the present embodiment has a brake 9 that restricts the rotation of each pulley 31, 32, 33, 34. The brake 9 is provided to the shaft portion 7 and restricts the rotation of each pulley 31, 32, 33, 34 by restricting the rotation of the shaft portion 7. As the brake 9, there is no particular limitation as long as it can be switched between a state of restricting the rotation of the shaft portion 7 and a state of allowing the rotation of the shaft portion 7.

[0080] In particular, the brake 9 is disposed on the upper side of the second bearing 62. Thereby, for example, compared to the case where the brake 9 is disposed on the lower side of the third pulley 33, since no component is interposed therebetween, the brake 9 can be disposed in the vicinity of the bearing. Thus, the rotation of the shaft portion 7 can be stably restricted by the brake 9. In addition, the brake 9 is fixed to the housing 141 of the second arm 140 via the link portion 8 on the inner side of the first belt 41 when viewed in the Z-axis direction. Thereby, the brake 9 hardly affects the attachment and detachment of the first belt 41.

[0081] The same effects as those of the first embodiment described above can be obtained by the fourth embodiment.

[0082] The drive mechanism and the robot of the present application have been described based on the illustrated embodiments, but the present application is not limited thereto, and the configuration of each part can be replaced with any configuration having the same function. In addition, any other configuration can be added to the present application. In addition, the drive mechanism can be applied to any device other than the robot.​

Claims

1. A robot, characterized in that, have: Base; The first arm is connected to the base and rotates about a first rotation axis relative to the base; The second arm is connected to the first arm and rotates about a second rotation axis relative to the first arm; A shaft is disposed on the second arm and rotates relative to the second arm about a third rotation axis; as well as A joint actuator connects the first arm and the second arm. The second arm has: case; The motor is fixed to the housing; The first pulley is connected to the motor and rotates around the first shaft; The second pulley is configured separately from the first pulley and rotates about a second axis parallel to the first axis; The first belt is wound around the first pulley and the second pulley; The third pulley is arranged and configured with the second pulley in the direction along the second axis, and rotates about the second axis; The shaft portion allows the second pulley and the third pulley to rotate integrally around the second shaft; The fourth pulley is configured separately from the third pulley and rotates about a third axis parallel to the second axis; The shaft is inserted through the spline nut, and the spline nut is connected to the fourth pulley; The second belt is wound around the third pulley and the fourth pulley; The first bearing has an inner ring and an outer ring concentrically arranged with the inner ring, and is located between the second pulley and the third pulley, and contacts the shaft portion; The second bearing has an inner ring and an outer ring concentrically arranged with the inner ring, and contacts the shaft portion; as well as The support portion has a first bearing support portion supporting the outer ring of the first bearing and a second bearing support portion supporting the outer ring of the second bearing, and is fixed to the housing. The third pulley is located between the first bearing and the second bearing, and is configured to be sandwiched between the first bearing and the second bearing. When the second bearing is viewed along a direction orthogonal to the second axis, the second bearing does not coincide with the third pulley. The outer diameter of the second pulley is larger than the outer diameter of the first pulley. The second pulley and the third pulley are different components from the support portion.

2. A robot, characterized in that, have: Base; The first arm is connected to the base and rotates about a first rotation axis relative to the base; The second arm is connected to the first arm and rotates about a second rotation axis relative to the first arm; A shaft is disposed on the second arm and rotates relative to the second arm about a third rotation axis; as well as A joint actuator connects the first arm and the second arm. The second arm has: case; The motor is fixed to the housing; The first pulley is connected to the motor and rotates around the first shaft; The second pulley is configured separately from the first pulley and rotates about a second axis parallel to the first axis; The first belt is wound around the first pulley and the second pulley; The third pulley is arranged and configured with the second pulley in the direction along the second axis, and rotates about the second axis; The fourth pulley is configured separately from the third pulley and rotates about a third axis parallel to the second axis; The shaft is inserted through the spline nut, and the spline nut is connected to the fourth pulley; The second belt is wound around the third pulley and the fourth pulley; The first bearing has an inner ring and an outer ring concentrically arranged with the inner ring, and is located between the second pulley and the third pulley; The second bearing has an inner ring and an outer ring concentrically arranged with the inner ring, and is arranged with the third pulley in a direction along the second axis; as well as The support portion has a first bearing support portion supporting the outer ring of the first bearing and a second bearing support portion supporting the outer ring of the second bearing, and is fixed to the housing. The third pulley is located between the first bearing and the second bearing, and is configured to be sandwiched between the first bearing and the second bearing. When the second bearing is viewed along a direction orthogonal to the second axis, the second bearing does not coincide with the third pulley. The outer diameter of the second pulley is larger than the outer diameter of the first pulley. The second pulley and the third pulley are different components from the support portion.

3. The robot according to claim 1 or 2, characterized in that, When the first bearing is viewed along a direction orthogonal to the second axis, the first bearing does not coincide with the second pulley.

4. The robot according to claim 1 or 2, characterized in that, The motor has a motor body and an output shaft. When the motor body is viewed along a direction orthogonal to the first shaft, the motor body does not coincide with the first bearing.

5. The robot according to claim 1 or 2, characterized in that, The motor has a motor body and an output shaft. When the motor body is viewed along a direction orthogonal to the first axis, the motor body does not coincide with the third pulley.

6. The robot according to claim 1 or 2, characterized in that, The tension of the second belt is greater than that of the first belt.

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