Robots and methods of adjustment

Abstract

The present application provides a robot and an adjustment method, which can easily adjust the separation distance of a belt and a restriction portion. The robot includes a power source; and a power transmission mechanism that transmits an output of the power source, the power transmission mechanism including a fixed member; a first pulley that rotates with respect to the fixed member about a first axis; a second pulley that is disposed separately from the first pulley and rotates with respect to the fixed member about a second axis that is parallel to the first axis; a belt that is hung around the first pulley and the second pulley and transmits rotation of one of the first pulley and the second pulley to the other; a restriction member that includes a restriction portion, the restriction portion being disposed in opposition to the belt with a gap at a portion where the first pulley engages with the belt; and a screw that fixes the restriction member to the fixed member with a center axis along the first axis, in which, when viewed from a direction along the first axis, the separation distance of the restriction portion from the belt changes as the restriction member rotates about the center axis.

Description

TECHNICAL FIELD

[0001] The present application relates to a robot and an adjustment method. BACKGROUND

[0002] For example, in Patent Literature 1, a structure is described in which a restriction member is fixed at a partition position separated by a prescribed interval from a timing belt, to restrict the skip of the timing belt engaged with a driven pulley.

[0003] Patent Literature 1: Japanese Patent Application Laid-Open (JP-A) No. 09-032897

[0004] However, in the case of applying Patent Literature 1 to a robot, since the fixing position of the restriction member is determined in Patent Literature 1, it is difficult to adjust the interval of the restriction member from the timing belt to an appropriate interval, and thus it is difficult to improve the drive characteristics of the robot. If the interval is too narrow, the restriction member comes into contact with the timing belt, causing the timing belt to wear and shorten the life, and conversely, if the interval is too wide, it is not possible to restrict the skip of the timing belt. SUMMARY

[0005] The robot of the present application has: a power source; and a power transmission mechanism that transmits the output of the power source, the power transmission mechanism having: a fixed member; a first pulley that rotates with respect to the fixed member about a first axis; a second pulley that is disposed separately from the first pulley, rotates with respect to the fixed member about a second axis parallel to the first axis; a belt that is hung around the first pulley and the second pulley, and transmits the rotation of one of the first pulley and the second pulley to the other; a restriction member that has a restriction portion that is disposed in opposition to the belt separated by a gap at a portion where the first pulley is engaged with the belt; and a screw that has a central axis along the first axis, fixes the restriction member to the fixed member, and in which, when viewed from a direction along the first axis, the separation distance of the restriction portion from the belt changes as the restriction member rotates about the central axis.

[0006] The adjustment method of the present application adjusts a separation distance of a restriction portion and a belt in a power transmission mechanism having a fixed member, a first pulley rotating with respect to the fixed member about a first axis, a second pulley disposed apart from the first pulley, rotating with respect to the fixed member about a second axis parallel to the first axis, the belt passing around the first pulley and the second pulley to transmit rotation of one of the first pulley and the second pulley to the other, a restriction member having the restriction portion, the restriction portion being disposed opposite the belt with a gap between the restriction portion and the belt at a portion where the first pulley engages with the belt, and a screw having a central axis along the first axis, fixing the restriction member to the fixed member, the separation distance of the restriction portion and the belt changing as the restriction member rotates about the central axis when viewed from a direction along the first axis, the adjustment method including an adjustment step of adjusting the separation distance by rotating the restriction member about the central axis in a state where the screw is loosened, and a fixing step of fixing the restriction member to the fixed member by tightening the screw. BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1 is a side view showing the overall structure of a robot according to the first embodiment.

[0008] Figure 2 is a plan view showing a power transmission mechanism possessed by the robot of Figure 1

[0009] Figure 3 is a sectional view showing the power transmission mechanism of Figure 2

[0010] Figure 4 is a bottom view showing a jump tooth suppression mechanism possessed by the drive mechanism of Figure 2

[0011] Figure 5 is a sectional view showing a restriction member possessed by the jump tooth suppression mechanism of Figure 4

[0012] Figure 6 is a flowchart showing a separation distance adjustment process of the belt and the restriction member.

[0013] Figure 7 is a bottom view for explaining the process shown in Figure 6

[0014] Figure 8 is a bottom view for explaining the process shown in Figure 6

[0015] Figure 9 is a bottom view for explaining the process shown in Figure 6 ​​​​​​A plan view of the procedure shown.

[0016] Figure 10 is a plan view showing a power transmission mechanism of the second embodiment.

[0017] Figure 11 is a sectional view showing a power transmission mechanism of the third embodiment.

[0018] Explanation of Reference Numerals

[0019] 10…jig; 100…robot; 110…base; 120…mechanical arm; 121…first arm; 122…second arm; 130…work head; 131…spline nut; 132…ball screw nut; 133…spline shaft; 140…end effector; 151…joint actuator; 152…joint actuator; 161…drive mechanism; 162…drive mechanism; 170…robot control device; 2…motor; 20…output shaft; 3…power transmission mechanism; 31…pulley; 32…pulley; 33…belt; 34…pulley; 341…flange; 342…flange; 35…pulley; 36…belt; 39…shaft; 4…fixed member; 40…insertion hole; 42…screw hole; 5…backlash suppression mechanism; 71…sensor; 72…sensor; 81…limit member; 810…screw hole; 811…limit portion; 811a…central axis; 812…protruding portion; 812a…central axis; 813…protruding portion; 814…insertion hole; 82…limit member; 9…screw; 90…central axis; A…arrow; B…arrow; BB…bearing; D…separation distance; DD…separation distance; H…engagement depth; J1…first rotation axis; J2…second rotation axis; J3…third rotation axis; JJ1…first rotation axis; JJ2…second rotation axis; JJ3…third rotation axis; L…length; S1…adjustment step; S2…fixing step; T1…first speed reducer; T2…second speed reducer. DETAILED DESCRIPTION

[0020] Hereinafter, the robot and the adjustment method of the present application will be described in detail based on the embodiments shown in the drawings. Note that the “parallel” in the present specification includes not only the parallel state but also a state slightly deviated from the parallel state. That is, it also includes a state that can be regarded as the same as the parallel state in terms of technical common sense.

[0021] <First Embodiment>

[0022] Figure 1 is a side view showing the overall structure of the robot according to the first embodiment. Figure 2 is a plan view showing a power transmission mechanism of the robot of Figure 1 Figure 3 is a plan view showing a power transmission mechanism of the robot of Figure 2 ​A cross-sectional view of the power transmission mechanism. Figure 4 It means Figure 2 A bottom view of the tooth skipping suppression mechanism of the drive mechanism. Figure 5 It means Figure 4 A cross-sectional view of the limiting component of the skipped tooth suppression mechanism. Figure 6 This is a flowchart illustrating the process of adjusting the separation distance between the belt and the limiting component. Figures 7 to 9 It is used for explanation Figure 6 The process shown is shown from below.

[0023] Figure 1 The robot 100 shown is a horizontal, multi-jointed robot, used for tasks such as holding, handling, assembling, and inspecting workpieces such as electronic components. However, the application of robot 100 is not particularly limited.

[0024] The robot 100 has a base 110 fixed to the ground and a robotic arm 120 connected to the base 110. The robotic arm 120 has: a first arm 121, the base end of which is connected to the base 110 and rotates relative to the base 110 about a first rotation axis J1 along the vertical direction; and a second arm 122, the base end of which is connected to the front end of the first arm 121 and rotates relative to the first arm 121 about a second rotation axis J2 along the vertical direction.

[0025] A working head 130 is provided at the front end of the second arm 122. The working head 130 has a spline nut 131 and a ball screw nut 132 coaxially disposed at the front end of the second arm 122, and a spline shaft 133 that passes through the spline nut 131 and the ball screw nut 132. The spline shaft 133 is rotatable relative to the second arm 122 about a third rotation axis J3 in the vertical direction, which is its central axis, and is also locating up and down along the third rotation axis J3.

[0026] An end effector 140 is mounted on the lower end of the splined shaft 133. The end effector 140 is freely detachable, and an end effector suitable for the target operation can be appropriately selected. Examples of end effectors 140 include a hand that holds a workpiece by clamping or adsorbing it, and a work tool that performs specified machining on the workpiece.

[0027] Additionally, the robot 100 includes: a joint actuator 151 connecting the base 110 and the first arm 121, and causing the first arm 121 to rotate relative to the base 110 about a first rotation axis J1; and a joint actuator 152 connecting the first arm 121 and the second arm 122, and causing the second arm 122 to rotate relative to the first arm 121 about a second rotation axis J2. Furthermore, the robot 100 includes: a drive mechanism 161 that rotates the spline nut 131 to rotate the spline shaft 133 about a third rotation axis J3; and a drive mechanism 162 that rotates the ball screw nut 132 to move the spline shaft 133 up and down in the direction along the third rotation axis J3.

[0028] Additionally, the robot 100 includes a robot control unit 170, which is disposed within the base 110. The robot control unit 170 controls the actuation of the joint actuators 151 and 152 and the drive mechanisms 161 and 162 based on instructions from a mainframe computer (not shown). The robot control unit 170 independently controls the joint actuators 151 and 152 and the drive mechanisms 161 and 162, thereby enabling the robot 100 to perform the desired tasks.

[0029] The robot control device 170 is, for example, a computer, having a processor for processing information, a memory communicatively connected to the processor, and an external interface. Furthermore, the memory stores various programs that can be executed by the processor, and the processor can read and execute these programs stored in the memory.

[0030] The above provides a brief description of the overall structure of robot 100. Next, based on... Figure 2 and Figure 3 The drive mechanism 161 that rotates the spline nut 131 to rotate the spline shaft 133 about the third rotation axis J3 will be described in detail.

[0031] like Figure 2 and Figure 3 As shown, the drive mechanism 161 includes a motor 2 as a drive source and a power transmission mechanism 3 that transmits the output of the motor 2 to the spline nut 131. The motor 2 is fixed to a fixing member 4 that forms the frame of the second arm 122, and its output shaft 20 rotates about a first rotation axis JJ1 along the vertical direction. The motor 2 is, for example, an AC servo motor. However, there is no particular limitation on the motor 2, and for example, a DC servo motor, a stepper motor, etc., can also be used.

[0032] The power transmission mechanism 3 has a pulley 31 connected to the output shaft 20 of the motor 2 and rotating integrally with the output shaft 20 about the first rotation axis JJl. In addition, the power transmission mechanism 3 has a pulley 32 disposed separately from the pulley 31 and rotating about the second rotation axis JJ2 in the plumb direction. The pulley 32 is disposed on the front end side of the second arm 122 with respect to the pulley 31 between the spline shaft 133 and the pulley 31. These pulleys 31, 32 are each a cogged pulley.

[0033] In addition, the power transmission mechanism 3 has a belt 33 wound around the pulley 31 and the pulley 32 and linking them. The belt 33 is a cogged belt engaging with the pulleys 31, 32. Therefore, when the pulley 31 rotates with the output shaft 20, the rotation is transmitted to the pulley 32 via the belt 33, and the pulley 32 rotates as a slave to the pulley 31. The outer diameter of the pulley 32 is larger than the outer diameter of the pulley 31. Therefore, the pulley 31, the belt 33, and the pulley 32 constitute a first speed reducer Tl that reduces the rotational speed of the output shaft 20.

[0034] In addition, the power transmission mechanism 3 has a pulley 34 as a first pulley disposed in line with the pulley 32 in the direction along the second rotation axis JJ2 and rotating about the second rotation axis JJ2. The pulley 34 is connected to the pulley 32 via a shaft 39 extending along the second rotation axis JJ2 and rotates integrally with the pulley 32. In addition, the outer diameter of the pulley 34 is smaller than the outer diameter of the pulley 32. In addition, the shaft 39 is supported to the fixed member 4 via a bearing BB interposed between the pulley 32 and the pulley 34.

[0035] In addition, the power transmission mechanism 3 has a pulley 35 as a second pulley disposed separately from the pulley 34 and rotating about the third rotation axis JJ3 in the vertical direction. The pulley 35 is disposed on the front end side of the second arm 122 with respect to the pulley 34 and coaxially with the spline shaft 133. That is, the third rotation axis JJ3 coincides with the third turning axis J3. In addition, the spline nut 131 is inserted through and fixed to the pulley 35, and they rotate integrally. These pulleys 34, 35 are each a cogged pulley.

[0036] In addition, the power transmission mechanism 3 has a belt 36 wound around the pulley 34 and the pulley 35 and linking them. The belt 36 is a cogged belt engaging with the pulleys 34, 35. Therefore, when the pulley 34 rotates, the rotation is transmitted to the pulley 35 via the belt 36, and the pulley 35 rotates as a slave to the pulley 34. Note that the outer diameter of the pulley 35 is larger than the outer diameter of the pulley 34. Therefore, the pulley 34, the belt 36, and the pulley 35 constitute a second speed reducer T2 that reduces the rotational speed of the output shaft 20.

[0037] In this power transmission mechanism 3, the output of the motor 2 is transmitted to the spline nut 131 via a first reducer T1 and a second reducer T2. By positioning the first reducer T1 and the second reducer T2 between the motor 2 and the spline nut 131, the rotational speed of the motor 2 can be sufficiently reduced, allowing the spline nut 131 to rotate at the desired speed. Furthermore, the configuration freedom of the motor 2 is increased, and the design of the second arm 122 becomes easier. In particular, by configuring two reducers T1 and T2 between the motor 2 and the spline nut 131, the outer diameter of the pulley 35 can be reduced compared to configuring a single reducer. Therefore, the widening and weight of the front end of the second arm 122 can be suppressed, and a robot 100 with excellent driving characteristics can be achieved.

[0038] Here, in order to increase the transportable weight of the end effector 140, the output of the motor 2 must be increased. However, if the output of the motor 2 is increased, a larger torque is applied to belts 33 and 36 accordingly. Furthermore, corresponding to the amount by which the rotational speed of the output shaft 20 is reduced by the first reducer T1, a larger torque is applied to belt 36 than to belt 33. In addition, to withstand the larger torque, belt 36 is thicker than belt 33, and correspondingly, belt 36 is stiffer and has a larger restoring force. Therefore, belt 36 is more prone to tooth skipping than belt 33. Furthermore, among the pulleys 34 and 35 that mesh with belt 36, tooth skipping is also more likely to occur on the side of pulley 34 with the smaller diameter. Therefore, the power transmission mechanism 3 has a tooth skipping suppression mechanism 5, which is used to suppress tooth skipping of belt 36 on pulley 34, which is most prone to tooth skipping among pulleys 31, 32, 34, and 35. This improves the drive characteristics of the robot 100.

[0039] The skipping tooth suppression mechanism 5 will be described in detail below. Figure 4 As shown, the skipped tooth suppression mechanism 5 has a pair of limiting members 81 and 82 arranged opposite to the pulley 34. When the pulley 34 rotates in the direction of the solid arrow A, the limiting member 81 is located near the position where the belt 36 and the pulley 34 begin to engage, and the limiting member 82 is located near the position where the belt 36 and the pulley 34 cease engagement. Conversely, when the pulley 34 rotates in the direction of the dashed arrow B, the limiting member 82 is located near the position where the belt 36 and the pulley 34 begin to engage, and the limiting member 81 is located near the position where the belt 36 and the pulley 34 cease engagement. Since this part is particularly prone to skipped teeth, this configuration effectively suppresses skipped teeth on the belt 36.

[0040] However, the configuration of limiting components 81 and 82 is not particularly limited. For example, limiting component 82 can be omitted, and only one limiting component 81 can be configured. In this case, depending on the intended use of the robot 100, the limiting component 81 can be configured in a location where teeth are prone to skipping.

[0041] The structures of limiting components 81 and 82 will be described in detail below. However, since they are identical structures, the following description will focus on limiting component 81 and omit the description of limiting component 82.

[0042] like Figure 5 As shown, the limiting member 81 is screwed to the fixing member 4 by a screw 9 having a central axis 90 along the second rotation axis JJ2. Specifically, the fixing member 4 has an insertion hole 40 for the screw 9 to pass through, and the limiting member 81 has a screw hole 810 with an opening on its lower surface that engages with the screw 9. The insertion hole 40 coincides with the screw hole 810, and the screw 9 is inserted into the insertion hole 40 from below and screwed into the screw hole 810. Thus, the limiting member 81 is fixed to the fixing member 4. Therefore, when the screw 9 is loosened, the limiting member 81 can rotate about the central axis 90; conversely, when the screw 9 is tightened, the limiting member 81 is fixed to the fixing member 4 and cannot rotate about the central axis 90.

[0043] This limiting member 81 has a limiting portion 811 and a protrusion 812 arranged along the central axis 90. The limiting portion 811 is arranged opposite to the belt 36 with a gap, and in case of abnormality, it limits the skipping of the belt 36 by contacting the belt 36. By forming a gap, the belt 36 does not contact the limiting portion 811 under normal conditions, thus suppressing wear of the belt 36 and extending the life of the belt 36. On the other hand, the protrusion 812 is formed by protruding downward from the limiting portion 811 and is configured to extend the limiting member 81 to the fixing member 4. That is, the protrusion 812 serves as a spacer to fill the gap between the limiting portion 811 and the fixing member 4. As a result, it becomes easy to fix the limiting member 81 to the fixing member 4.

[0044] Furthermore, both the limiting portion 811 and the protrusion 812 are cylindrical, with the diameter of the limiting portion 811 being larger than the diameter of the protrusion 812. By making the limiting portion 811 and the protrusion 812 cylindrical, they can be formed by cutting, thus enabling easy and inexpensive manufacturing of the limiting component 81. However, the shapes of the limiting portion 811 and the protrusion 812 are not particularly limited. The limiting portion 811 can be, for example, a triangular prism, an elliptical prism, etc., as described later, as long as the shape changes the separation distance DD between the limiting portion 811 and the belt 36 by rotating around the central axis 90.

[0045] Furthermore, the central axis 812a of the protrusion 812 coincides with the central axis 90, while the central axis 811a of the limiting part 811 is separate from the central axis 90. That is, the limiting part 811 is eccentric relative to the central axis 90. Therefore, when the screw 9 is loosened and the limiting member 81 rotates relative to the fixing member 4 about the central axis 90, the limiting part 811 rotates eccentrically about the central axis 90, thereby changing the separation distance DD between the limiting part 811 and the belt 36. By appropriately adjusting this separation distance DD, the skipping of the belt 36 can be effectively limited. In this way, by making the limiting part 811 a structure that can rotate eccentrically about the central axis 90, adjusting the separation distance DD becomes easy. It should be noted that the separation distance DD is not particularly limited, but for example, it is preferable to be shorter than the engagement depth H between the belt 36 and the pulley 34. That is, it is preferable that DD < H (refer to...). Figure 4 Therefore, it is possible to more effectively limit skipped teeth with 36.

[0046] Here, as Figure 5 As shown, the pulley 34 has a pair of flanges 341 and 342 located on both sides of the belt 36. These flanges 341 and 342 restrict the belt 36 from disengaging. Furthermore, when the separation distance of these flanges 341 and 342 is set as D, and the length of the limiting portion 811 along the central axis 90 is set as L, the relationship becomes D > L. Further, the upper end of the limiting portion 811 is located below the upper flange 341, and the lower end is located above the lower flange 342. Therefore, the limiting portion 811 can enter between the flanges 341 and 342, increasing the adjustment range of the separation distance DD. However, this is not a limitation; for example, if the separation distance DD can be adjusted to an appropriate distance (e.g., DD < H) even without the limiting portion 811 entering between the flanges 341 and 342, D ≤ L may also be acceptable.

[0047] The power transmission mechanism 3 has been described above. Next, the method for adjusting the separation distance DD in the power transmission mechanism 3 will be explained. This adjustment method will be explained using the limiting component 81 as an example; the description of the limiting component 82 will be omitted. Figure 6 As shown, the method for adjusting the separation distance DD includes: adjustment step S1, in which the limiting member 81 is rotated around the central axis 90 with the screw 9 loosened to adjust the separation distance DD to a predetermined distance; and fixing step S2, in which the limiting member 81 is fixed to the fixing member 4 by tightening the screw 9. According to this adjustment method, the separation distance DD can be easily adjusted. In particular, in this embodiment, as described below, adjustment step S1 and fixing step S2 are performed simultaneously in one step.

[0048] First, loosen screw 9 so that the limiting member 81 can rotate about the central axis 90. Then, as... Figure 7As shown, a flat clamp 10 is disposed between the limiting part 811 and the belt 36. It should be noted that the thickness of the clamp 10 is designed to be equal to the target value of the separation distance DD. In addition, the clamp 10 is made of a sufficiently hard material such as metal, so that, as will be described later, it will not substantially deform when clamped by the limiting part 811 and the belt 36.

[0049] Next, as Figure 8 As shown, screw 9 is tightened to fix the limiting member 81 to the fixing member 4. At this time, due to the frictional resistance generated at the screw engagement portion of screw 9 and limiting member 81, limiting member 81 and screw 9 rotate together. The rotation of limiting member 81 stops when limiting part 811 abuts against clamp 10 and clamps clamp 10 by limiting part 811 and band 36. Furthermore, if screw 9 is tightened directly, limiting member 81 is fixed to fixing member 4 in the same state, that is, in the state where clamps clamp 10 by limiting part 811 and band 36. From this process, it can be seen that limiting member 81 is configured such that the separation distance DD decreases due to rotation in the screw tightening direction.

[0050] Finally, as Figure 9 As shown, if the clamp 10 is removed between the limiting part 811 and the belt 36, a separation distance DD is formed that is equivalent to the thickness of the clamp 10. According to the adjustment method described above, since only the clamp 10 needs to be configured and the screw 9 tightened, the separation distance DD can be adjusted simply and with high precision. In particular, in this embodiment, since the adjustment step S1 and the fixing step S2 are performed simultaneously in one step, the adjustment process is reduced, and correspondingly, the adjustment becomes easier.

[0051] The robot 100 has been described above. As described above, such a robot 100 has a motor 2 as a power source and a power transmission mechanism 3 for transmitting the output of the motor 2. Furthermore, the power transmission mechanism 3 includes: a fixing member 4; a pulley 34 as a first pulley that rotates relative to the fixing member 4 about a first axis, i.e., a second rotation axis JJ2; a pulley 35 as a second pulley that is separately disposed from the pulley 34 and rotates relative to the fixing member 4 about a second axis, i.e., a third rotation axis JJ3, which is parallel to the second rotation axis JJ2; a belt 36 that is wound around the pulleys 34 and 35 and transmits the rotation of one of the pulleys 34 and 35 to the other; a limiting member 81 that has a limiting portion 811 that is disposed opposite to the belt 36 at the part where the pulley 34 engages with the belt 36, separated by a gap; and a screw 9 that fixes the limiting member 81 to the fixing member 4 along the second rotation axis JJ2 with a central axis 90. Furthermore, when viewed from above along the second rotation axis JJ2, the separation distance DD between the limiting part 811 and the belt 36 changes as the limiting part 81 rotates around the central axis 90. Based on this structure, a robot 100 becomes one where the separation distance DD can be easily adjusted.

[0052] Further, as described above, the separation distance DD is shorter than the meshing depth H of the pulley 34 and the belt 36. Thereby, it is possible to more reliably restrict the skip of the belt 36.

[0053] Further, as described above, the pulley 34 has a pair of flanges 341, 342 located on both sides in the direction along the second rotation axis JJ2 of the belt 36. Thereby, it is possible to restrict the belt 36 from disengaging from the pulley 34.

[0054] Further, as described above, the length L of the restriction portion 811 along the center axis 90 is shorter than the separation distance D of the pair of flanges 341, 342, and the restriction portion 811 enters between the pair of flanges 341, 342 by rotating around the center axis 90. Thereby, it is possible to adjust the separation distance DD without being hindered by the flanges 341, 342.

[0055] Further, as described above, the restriction portion 811 is in a cylindrical shape that is eccentrically arranged with respect to the center axis 90. Thereby, it is possible to form the restriction portion 811 by cutting, and thus it is possible to easily and inexpensively manufacture the restriction member 81.

[0056] Further, as described above, the restriction member 81 has a protrusion portion 812 protruding from the restriction portion 811 and located between the restriction portion 811 and the fixed member 4. Such a protrusion portion 812 serves as a spacer between the restriction portion 811 and the fixed member 4. Thereby, it becomes easy to fix the restriction member 81 to the fixed member 4.

[0057] Further, as described above, the robot 100 has: a base 110; a first arm 121 connected to the base 110 and rotating with respect to the base 110 around a first rotation axis J1; a second arm 122 connected to the first arm 121 and rotating with respect to the first arm 121 around a second rotation axis J2; and a spline shaft 133 arranged to the second arm 122 and rotating with respect to the second arm 122 around a third rotation axis J3. Also, the power transmission mechanism 3 transmits the output of the motor 2 to rotate the spline shaft 133 around the third rotation axis J3. In such a structure, in order to increase the portable weight of the robot 100, it is necessary to increase the output of the motor 2, but if the output of the motor 2 is increased, it is more likely to occur skip. Therefore, it is possible to more significantly exert the restriction effect of the restriction member 81 on the skip, thereby improving the drive characteristics of the robot 100.

[0058] Further, as described above, the power transmission mechanism 3 has: the fixed member 4; the pulley 34 as a first pulley that rotates with respect to the fixed member 4 about a first axis, i.e., a second rotation axis JJ2; the pulley 35 as a second pulley that is disposed separately from the pulley 34 and rotates with respect to the fixed member 4 about a second axis, i.e., a third rotation axis JJ3, that is parallel to the second rotation axis JJ2; the belt 36 that is hung around the pulley 34 and the pulley 35 and transmits rotation of one of the pulley 34 and the pulley 35 to the other; the restriction member 81 that has the restriction portion 811 that is disposed in opposition to the belt 36 with a gap between the belt 36 at a portion where the pulley 34 and the belt 36 engage; and the screw 9 that has the central axis 90 along the second rotation axis JJ2 and fixes the restriction member 81 to the fixed member 4. Further, when viewed from a direction along the second rotation axis JJ2, the separation distance DD of the restriction portion 811 from the belt 36 changes as the restriction member 81 rotates about the central axis 90. According to such a structure, the power transmission mechanism 3 becomes one in which the separation distance DD is easily adjusted.

[0059] Further, as described above, the adjustment method is a method of adjusting the separation distance DD of the restriction portion 811 from the belt 36 in the power transmission mechanism 3. The power transmission mechanism 3 has: the fixed member 4; the pulley 34 as a first pulley that rotates with respect to the fixed member 4 about a first axis, i.e., a second rotation axis JJ2; the pulley 35 as a second pulley that is disposed separately from the pulley 34 and rotates with respect to the fixed member 4 about a second axis, i.e., a third rotation axis JJ3, that is parallel to the second rotation axis JJ2; the belt 36 that is hung around the pulley 34 and the pulley 35 and transmits rotation of one of the pulley 34 and the pulley 35 to the other; the restriction member 81 that has the restriction portion 811 that is disposed in opposition to the belt 36 with a gap between the belt 36 at a portion where the pulley 34 and the belt 36 engage; and the screw 9 that has the central axis 90 along the second rotation axis JJ2 and fixes the restriction member 81 to the fixed member 4, when viewed from a direction along the second rotation axis JJ2, the separation distance DD of the restriction portion 811 from the belt 36 changes as the restriction member 81 rotates about the central axis 90. The adjustment method includes: an adjustment step S1 of adjusting the separation distance DD by rotating the restriction member 81 about the central axis 90 in a state where the screw 9 is loosened; and a fixing step S2 of fixing the restriction member 81 to the fixed member 4 by tightening the screw 9. According to such a method, the separation distance DD can be easily and highly accurately adjusted.

[0060] Further, as described above, in the adjustment step S1, the separation distance DD is adjusted by disposing the jig 10 between the restriction portion 811 and the belt 36 and sandwiching the jig 10 with the restriction portion 811 and the belt 36. According to such a method, by setting the thickness of the jig 10 to a target value of the separation distance DD, the separation distance DD can be easily adjusted to the target value. Therefore, the separation distance DD can be easily and highly accurately adjusted.

[0061] In addition, as described above, when the screw 9 is tightened to fix the restriction member 81 to the fixing member 4, the restriction member 81 is rotated together with the screw 9 around the center axis 90 by the friction between the screw 9 and the restriction member 81, whereby the adjustment step S1 and the fixing step S2 are simultaneously performed. Thus, the adjustment procedure is reduced, and accordingly, the adjustment becomes easier.

[0062] <Second Embodiment>

[0063] Figure 10 is a plan view showing the power transmission mechanism of the second embodiment.

[0064] In the robot 100 of the present embodiment, the same as the above first embodiment except that the structure of the power transmission mechanism 3 is different. Therefore, in the following description, the present embodiment is described with the difference from the above first embodiment as the center, and the same matters are omitted from the description. In addition, in each drawing of the present embodiment, the same reference numerals are attached to the same structures as those of the above embodiments.

[0065] As shown in Figure 10 the power transmission mechanism 3 of the present embodiment has a sensor 71 provided to the restriction member 81 to detect the contact of the restriction portion 811 with the belt 36. Thus, it is possible to detect the abnormality of the power transmission mechanism 3, for example, to be used as a material to judge whether or not maintenance is required, and the like. As the sensor 71, there is no particular limitation, and for example, a force sensor, a strain gauge, a simple switch, or the like can be used. In addition, in the present embodiment, the sensor 71 is disposed to the outer peripheral surface of the restriction portion 811, but the disposition of the sensor 71 is not particularly limited. The above describes the sensor 71, but the same sensor 72 is also provided to the restriction member 82.

[0066] Thus, the power transmission mechanism 3 of the present embodiment has the sensor 71 to detect the contact of the restriction portion 811 with the belt 36. Thus, it is possible to detect the abnormality of the power transmission mechanism 3, for example, to be used as a material to judge whether or not maintenance is required, and the like.

[0067] According to the second embodiment as described above, the same effects as those of the above first embodiment can also be exerted.

[0068] <Third Embodiment>

[0069] Figure 11 is a sectional view showing the power transmission mechanism of the third embodiment.

[0070] In the robot 100 of the present embodiment, the structure of the restriction member 81, 82 is different from the above-described first embodiment, but is the same as the above-described first embodiment in other respects. Therefore, in the following description, the present embodiment will be described focusing on the points of difference from the above-described first embodiment, and the same matters will be omitted from the description. In addition, in each drawing of the present embodiment, the same reference numerals are attached to the structures that are the same as those of the above-described embodiments. In addition, since the restriction members 81, 82 are structures that are the same as each other, the following description will be given taking the restriction member 81 as a representative, and the description of the restriction member 82 will be omitted.

[0071] As shown in FIG. 8, the restriction member 81 is supported by the fixing member 4 on both sides in the direction along the center axis 90, i.e., on the upper end side and the lower end side. Thereby, since the restriction member 81 is supported at both ends by the fixing member 4, the posture of the restriction member 81 is more stable, for example, as compared with the first embodiment of the cantilever support structure. Therefore, the adjustment accuracy of the separation distance DD is improved. Figure 11

[0072] In addition, the restriction member 81 has a restriction portion 811, a protrusion portion 812 protruding downward from the restriction portion 811, and a protrusion portion 813 protruding upward from the restriction portion 811. The protrusion portion 813 is also in a cylindrical shape with the center axis coinciding with the center axis 90. In addition, on the restriction member 81, instead of the screw hole 810, a through hole 814 is formed that penetrates the upper surface and the lower surface thereof for the screw 9 to pass through.

[0073] In addition, on the fixing member 4, in addition to the through hole 40, a screw hole 42 is formed at a position overlapping the through hole 40, into which the screw 9 is screwed. And the screw 9 is inserted into the screw hole 42, passing through the through hole 40 and the through hole 814 from the lower side. Thereby, the restriction member 81 is fixed in a state of being supported at both ends by the fixing member 4.

[0074] In such a power transmission mechanism 3, adjustment of the separation distance DD is performed as follows. First, the screw 9 is loosened, and the restriction member 81 is brought into a state of being rotatable about the center axis 90. Next, the plate-shaped jig 10 is disposed between the restriction portion 811 and the belt 36. Next, the restriction member 81 is rotated about the center axis 90, and brought into a state of sandwiching the jig 10 by the restriction portion 811 and the belt 36. Next, in a state of maintaining this state, the screw 9 is tightened, and the restriction member 81 is fixed to the fixing member 4. And finally, the jig 10 is removed from between the restriction portion 811 and the belt 36. According to the adjustment method as described above, adjustment of the separation distance DD can be performed simply and with high accuracy.

[0075] ​Thus, in the power transmission mechanism 3 of the present embodiment, the restriction member 81 is supported by the fixing member 4 on both sides in the direction along the center axis 90. Thus, since the restriction member 81 is supported at both ends by the fixing member 4, the posture of the restriction member 81 is more stable than, for example, the first embodiment of the cantilever support structure. Thus, the adjustment accuracy of the separation distance DD is improved.

[0076] According to the third embodiment as described above, the same effects as the first embodiment described above can also be achieved.

[0077] The robot and the adjustment method of the present application have been described above based on the illustrated embodiments, but the present application is not limited thereto, and the structure of each part can be replaced with any structure having the same function. In addition, any other structure can be added to the present application. In addition, the power drive mechanism can be applied to any device other than a 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 relative to the first arm about a second rotation axis; as well as A splined shaft, disposed on the second arm, rotates relative to the second arm about a third rotation axis. The second arm has: Fixed components; A motor, connected to the fixed component, has an output shaft; The first pulley is connected to the output shaft of the motor and rotates about the first rotation axis relative to the fixed component; The second pulley is configured separately from the first pulley and rotates relative to the fixed component about a second rotation axis parallel to the first rotation axis. The outer diameter of the second pulley is larger than the outer diameter of the first pulley. The first belt is wound around the first pulley and the second pulley; A third pulley is arranged in the direction along the second rotation axis with the second pulley and rotates about the second rotation axis relative to the fixed member. The outer diameter of the third pulley is smaller than the outer diameter of the second pulley. The fourth pulley is separately configured from the third pulley and rotates relative to the fixed component about a third rotation axis parallel to the second rotation axis. The outer diameter of the fourth pulley is larger than that of the third pulley. The second belt is wound around the third pulley and the fourth pulley; The bearing is located between the second pulley and the third pulley; A limiting member comprising a limiting portion and a protrusion, the limiting portion being disposed opposite to the second belt at the portion where the third pulley engages with the second belt, spaced apart by a gap, the protrusion protruding from the limiting portion and located between the limiting portion and the fixing member; and A screw, with its central axis parallel to the second rotation axis, secures the limiting component to the fixing component. The third pulley has a pair of flanges located on both sides of the second belt along the direction of the second axis of rotation. The length of the limiting portion along the central axis is shorter than the separation distance of the pair of flanges of the third pulley. As the limiting member rotates about the central axis, the separation distance between the limiting portion and the second band changes when viewed from a top view along the second rotation axis, and the limiting portion can enter between the pair of flanges. The protrusion contacts the fixing component at its end. When viewed from above in a direction orthogonal to the direction along the central axis, the end of the protrusion is located in a position that does not overlap with the third pulley.

2. The robot according to claim 1, characterized in that, The separation distance is shorter than the engagement depth between the third pulley and the second belt.

3. The robot according to claim 1, characterized in that, The limiting part is cylindrical and eccentrically positioned relative to the central axis.

4. The robot according to claim 1, characterized in that, The robot has a sensor that detects contact between the limiting part and the second belt.

5. The robot according to claim 1, characterized in that, The limiting component is supported by the fixing component on both sides along the direction of the central axis.

6. 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 relative to the first arm about a second rotation axis; as well as A splined shaft, disposed on the second arm, rotates relative to the second arm about a third rotation axis. The second arm has: Fixed components; A motor, connected to the fixed component, has an output shaft; The first pulley is connected to the output shaft of the motor and rotates about the first rotation axis relative to the fixed component; The second pulley is configured separately from the first pulley and rotates relative to the fixed component about a second rotation axis parallel to the first rotation axis. The outer diameter of the second pulley is larger than the outer diameter of the first pulley. The first belt is wound around the first pulley and the second pulley; A third pulley is arranged in the direction along the second rotation axis with the second pulley and rotates about the second rotation axis relative to the fixed member. The outer diameter of the third pulley is smaller than the outer diameter of the second pulley. The fourth pulley is separately configured from the third pulley and rotates relative to the fixed component about a third rotation axis parallel to the second rotation axis. The outer diameter of the fourth pulley is larger than that of the third pulley. The second belt is wound around the third pulley and the fourth pulley; The bearing is located between the second pulley and the third pulley; The limiting member includes a limiting portion disposed opposite to the second band with a gap between it and a protrusion protruding from the limiting portion and located between the limiting portion and the fixing member; as well as A screw, with its central axis parallel to the second rotation axis, secures the limiting component to the fixing component. The third pulley has a pair of flanges located on both sides of the second belt along the direction of the second axis of rotation. The length of the limiting portion along the central axis is shorter than the separation distance between the pair of flanges of the third pulley, and the limiting portion can enter between the pair of flanges. The protrusion contacts the fixing component at its end. When viewed from above in a direction orthogonal to the direction along the central axis, the end of the protrusion is located in a position that does not overlap with the third pulley.

7. An adjustment method, characterized in that, Adjust the separation distance between the limiting part and the belt in the power transmission mechanism. The power transmission mechanism has: Fixed components; The first pulley rotates about a first axis relative to the fixed component; The second pulley is configured separately from the first pulley and rotates relative to the fixed component about a second axis parallel to the first axis. The belt is wound around the first pulley and the second pulley, transmitting the rotation of one of the first pulley and the second pulley to the other; A limiting member includes the limiting portion, which is disposed opposite to the belt at the portion where the first pulley engages with the belt, separated by a gap. as well as A screw, with its central axis along the first axis, secures the limiting component to the fixing component. When viewed from above along the first axis, the separation distance between the limiting portion and the belt changes as the limiting member rotates about the central axis. The adjustment method includes: The adjustment procedure involves rotating the limiting component around the central axis while the screw is loosened to adjust the separation distance. as well as The fixing step involves tightening the screws to secure the limiting component to the fixing component. In the adjustment step, the separation distance is adjusted by placing a clamp between the limiting part and the belt, and by using the limiting part and the belt to clamp the clamp.

8. The adjustment method according to claim 7, characterized in that, When the screw is tightened to fix the limiting member to the fixing member, the limiting member and the screw are rotated together around the central axis by the friction between the screw and the limiting member, thereby performing the adjustment step and the fixing step simultaneously.

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