Horizontal articulated robot and adjustment method

Abstract

To provide a robot and an adjustment method which can easily adjust a separation distance between a belt and a regulation part.SOLUTION: The robot comprises a power source and a power transmission mechanism that transmits output of the power source. The power transmission mechanism has: a stationary member; a first pulley that rotates around a first shaft with respect to the stationary member; a second pulley, arranged away from the first pulley, which rotates around a second shaft which is parrel to the first shaft with respect to the stationary member; a belt, wound around the first pulley and the second pulley, through which rotation at one side is transmitted to the other side; a regulation member comprising a regulation part arranged oppositely to the belt across a clearance, at a portion at which the first pully engages with the belt; and a screw having a center shaft disposed along the first shaft, which fixes the regulation member to the stationary member. In a planar view from a direction along the first shaft, when the regulation member rotates around the center shaft, a separation distance between the regulation part and the belt changes.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention provides Horizontal articulated The present invention relates to a robot and an adjustment method. [Background technology]

[0002] For example, Patent Document 1 describes a structure in which a regulating member is fixed at a position spaced a predetermined distance from a timing belt in order to regulate tooth skipping of the timing belt meshing with a driven pulley. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 09-032897 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when Patent Document 1 is applied to a robot, it is difficult to adjust the gap between the regulating member and the timing belt to an appropriate gap because the fixed position of the regulating member is fixed in Patent Document 1, making it difficult to improve the robot's drive characteristics. If the gap is too narrow, the regulating member and the timing belt come into contact, causing wear on the timing belt and shortening its lifespan. Conversely, if the gap is too wide, it becomes impossible to regulate timing belt tooth skipping. [Means for solving the problem]

[0005] The robot of the present invention comprises: a power source; a power transmission mechanism that transmits the output of the power source, The power transmission mechanism includes a fixed member and a first pulley that rotates about a first axis relative to the fixed member; a second pulley that is spaced apart from the first pulley and that rotates relative to the fixed member about a second axis that is parallel to the first axis; a belt that is wound 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 regulating member including a regulating portion disposed opposite the belt across a gap at a portion where the first pulley and the belt mesh; a screw having a central axis aligned with the first axis and configured to fix the restricting member to the fixing member; In a plan view from a direction along the first axis, the regulation member rotates around the central axis, thereby changing the distance between the regulation portion and the belt.

[0006] The adjustment method of the present invention includes: a first pulley that rotates about a first axis relative to the fixed member; a second pulley that is spaced apart from the first pulley and that rotates relative to the fixed member about a second axis that is parallel to the first axis; a belt that is wound 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 regulating member including a regulating portion disposed opposite the belt across a gap at a portion where the first pulley and the belt mesh; a screw having a central axis aligned with the first axis and configured to fix the restricting member to the fixing member; An adjustment method for adjusting a separation distance between a regulating portion and a belt in a power transmission mechanism in which the separation distance between the regulating portion and the belt changes as the regulating member rotates around the central axis in a plan view from a direction along the first axis, adjusting the separation distance by rotating the regulating member around the central axis while the screw is loosened; and fastening the screw to fix the restricting member to the fixing member. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a side view showing the overall configuration of a robot according to a first embodiment. [Figure 2] 2 is a top view showing a power transmission mechanism of the robot of FIG. 1. FIG. [Figure 3] FIG. 3 is a cross-sectional view showing the power transmission mechanism of FIG. 2. [Figure 4] 3 is a bottom view showing a tooth skipping suppression mechanism included in the drive mechanism of FIG. 2. FIG. [Figure 5] 5 is a cross-sectional view showing a restricting member of the tooth skipping suppression mechanism of FIG. 4. [Figure 6] 10 is a flowchart showing a process for adjusting the distance between the belt and the regulating member. [Figure 7] FIG. 7 is a bottom view for explaining the step shown in FIG. 6. [Figure 8] FIG. 7 is a bottom view for explaining the step shown in FIG. 6. [Figure 9] FIG. 7 is a bottom view for explaining the step shown in FIG. 6. [Figure 10] FIG. 10 is a bottom view showing the power transmission mechanism of the second embodiment. [Figure 11] FIG. 10 is a cross-sectional view showing a power transmission mechanism according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] The robot and adjustment method of the present invention will be described in detail below with reference to the embodiments shown in the accompanying drawings. Note that the term "parallel" in this specification means not only parallel but also a state slightly deviated from parallel. In other words, it also means a state that can be considered the same as parallel according to common technical knowledge.

[0009] First Embodiment FIG. 1 is a side view showing the overall configuration of a robot according to a first embodiment. FIG. 2 is a top view showing a power transmission mechanism of the robot of FIG. 1. FIG. 3 is a cross-sectional view showing the power transmission mechanism of FIG. 2. FIG. 4 is a bottom view showing a tooth skipping suppression mechanism of the drive mechanism of FIG. 2. FIG. 5 is a cross-sectional view showing a regulating member of the tooth skipping suppression mechanism of FIG. 4. FIG. 6 is a flowchart showing a process for adjusting the separation distance between a belt and a regulating member. FIGS. 7 to 9 are bottom views for explaining the process shown in FIG. 6.

[0010] 1 is a SCARA robot, and is used for tasks such as holding, transporting, assembling, and inspecting workpieces such as electronic components, etc. However, the use of the robot 100 is not particularly limited.

[0011] The robot 100 has a base 110 fixed to the floor surface and a robot arm 120 connected to the base 110. The robot arm 120 also has a first arm 121 whose base end is connected to the base 110 and which rotates around a first rotation axis J1 that is vertical to the base 110, and a second arm 122 whose base end is connected to a tip end of the first arm 121 and which rotates around a second rotation axis J2 that is vertical to the first arm 121.

[0012] A working head 130 is provided at the tip of the second arm 122. The working head 130 has a spline nut 131 and a ball screw nut 132 that are coaxially arranged at the tip of the second arm 122, and a spline shaft 133 that is inserted 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 that is its central axis and extends in the vertical direction, and is also movable up and down along the third rotation axis J3.

[0013] An end effector 140 is attached to the lower end of the spline shaft 133. The end effector 140 is detachable and can be selected appropriately for the intended task. Examples of the end effector 140 include a hand that clamps and holds a workpiece by suction, and a work tool that performs a predetermined processing on the workpiece.

[0014] The robot 100 also includes a joint actuator 151 that connects the base 110 and the first arm 121 and rotates the first arm 121 about a first rotation axis J1 relative to the base 110, and a joint actuator 152 that connects the first arm 121 and the second arm 122 and rotates the second arm 122 about a second rotation axis J2 relative to the first arm 121. The robot 100 also 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 raise and lower the spline shaft 133 in a direction along the third rotation axis J3.

[0015] The robot 100 also has a robot control device 170 that is disposed within the base 110 and controls the driving of the joint actuators 151, 152 and the drive mechanisms 161, 162 based on commands from a host computer (not shown). The robot control device 170 controls the joint actuators 151, 152 and the drive mechanisms 161, 162 independently, thereby allowing the robot 100 to perform a desired task.

[0016] The robot control device 170 is configured, for example, by a computer, and has a processor for processing information, a memory communicatively connected to the processor, and an external interface. The memory also stores various programs that can be executed by the processor, and the processor can read and execute the various programs stored in the memory.

[0017] The above is a brief description of the overall configuration of the robot 100. Next, 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 with reference to FIGS.

[0018] As shown in FIGS. 2 and 3, 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 fixed member 4 that constitutes the frame of the second arm 122, and its output shaft 20 rotates around a first rotation axis JJ1 that is aligned in the vertical direction. The motor 2 is, for example, an AC servo motor. However, the motor 2 is not particularly limited, and for example, a DC servo motor, a stepping motor, or the like may also be used.

[0019] The power transmission mechanism 3 is connected to the output shaft 20 of the motor 2 and has a pulley 31 that rotates integrally with the output shaft 20 about a first rotation axis JJ1. The power transmission mechanism 3 also has a pulley 32 that is spaced apart from the pulley 31 and rotates about a second rotation axis JJ2 that is aligned in the vertical direction. The pulley 32 is located on the tip side of the second arm 122 relative to the pulley 31, and is positioned between the spline shaft 133 and the pulley 31. These pulleys 31 and 32 are each a toothed pulley.

[0020] The power transmission mechanism 3 also includes a belt 33 that is wound around and connects the pulleys 31 and 32. The belt 33 is a toothed belt that meshes with the pulleys 31 and 32. Therefore, when the pulley 31 rotates together with the output shaft 20, the rotation is transmitted to the pulley 32 via the belt 33, and the pulley 32 rotates following 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 form a first reducer T1 that reduces the rotation speed of the output shaft 20.

[0021] The power transmission mechanism 3 also includes a pulley 34 serving as a first pulley that is arranged alongside the pulley 32 in a direction along the second rotation axis JJ2 and rotates about the second rotation axis JJ2. The pulley 34 is connected to the pulley 32 via a shaft 39 that extends along the second rotation axis JJ2, and rotates integrally with the pulley 32. The outer diameter of the pulley 34 is smaller than the outer diameter of the pulley 32. The shaft 39 is journaled to the fixed member 4 via a bearing BB between the pulley 32 and the pulley 34.

[0022] The power transmission mechanism 3 also includes a second pulley, pulley 35, which is spaced apart from pulley 34 and rotates about a third rotation axis JJ3 that is aligned in the vertical direction. Pulley 35 is located on the distal end side of the second arm 122 relative to pulley 34 and is coaxial with spline shaft 133. In other words, the third rotation axis JJ3 coincides with the third pivot axis J3. A spline nut 131 is inserted and fixed to pulley 35, and the pulleys rotate integrally. Each of these pulleys 34 and 35 is a toothed pulley.

[0023] The power transmission mechanism 3 also includes a belt 36 that is wound around and connects the pulleys 34 and 35. The belt 36 is a toothed belt that meshes with the pulleys 34 and 35. Therefore, when the pulley 34 rotates, the rotation is transmitted to the pulley 35 via the belt 36, and the pulley 35 rotates following the pulley 34. 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 form a second reducer T2 that reduces the rotation speed of the output shaft 20.

[0024] In this power transmission mechanism 3, the output of the motor 2 is transmitted to the spline nut 131 via the first reducer T1 and the second reducer T2. By providing the first and second reducers T1 and 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 a desired rotational speed. This also increases the degree of freedom in arranging the motor 2, making it easier to design the second arm 122. In particular, by providing two reducers T1 and T2 between the motor 2 and the spline nut 131, the outer diameter of the pulley 35 can be made smaller than when a single reducer is provided. This prevents the tip of the second arm 122 from becoming bulky and heavy, resulting in a robot 100 with excellent drive characteristics.

[0025] Here, to increase the payload capacity of the end effector 140, the output of the motor 2 must be increased. However, increasing the output of the motor 2 results in a correspondingly larger torque being applied to the belts 33 and 36. Furthermore, because the rotation speed of the output shaft 20 is reduced by the first reducer T1, a larger torque is applied to the belt 36 than to the belt 33. Furthermore, the belt 36 is thicker than the belt 33 to withstand the larger torque, and therefore the belt 36 is stiffer and has a greater restoring force. Therefore, the belt 36 is more susceptible to tooth skipping than the belt 33. Furthermore, among the pulleys 34 and 35 that mesh with the belt 36, tooth skipping is more likely to occur on the pulley 34 side, which has a smaller diameter. Therefore, the power transmission mechanism 3 includes a tooth skipping suppression mechanism 5 for suppressing tooth skipping of the belt 36 at the pulley 34, which is the most susceptible to tooth skipping among the pulleys 31, 32, 34, and 35. This improves the driving characteristics of the robot 100.

[0026] The tooth skipping suppression mechanism 5 will be described in detail below. As shown in Fig. 4, the tooth skipping suppression mechanism 5 has a pair of regulating members 81, 82 arranged opposite the pulley 34. When the pulley 34 rotates in the direction of the solid arrow A, the regulating member 81 is located near the position where the meshing between the belt 36 and the pulley 34 starts, and the regulating member 82 is located near the position where the meshing between the belt 36 and the pulley 34 ends. Conversely, when the pulley 34 rotates in the direction of the dashed arrow B, the regulating member 82 is located near the position where the meshing between the belt 36 and the pulley 34 starts, and the regulating member 81 is located near the position where the meshing between the belt 36 and the pulley 34 ends. position Since this is a location where tooth skipping is particularly likely to occur, such an arrangement can effectively prevent tooth skipping of the belt 36.

[0027] However, there is no particular limitation on the arrangement of the regulating members 81 and 82. For example, the regulating member 82 may be omitted, and only one regulating member 81 may be arranged. In this case, the regulating member 81 may be arranged in a location where tooth skipping is likely to occur, depending on the intended use of the robot 100.

[0028] The structures of the regulating members 81 and 82 will be described in detail below, but since they have the same configuration, the regulating member 81 will be described below as a representative, and the description of the regulating member 82 will be omitted.

[0029] As shown in FIG. 5 , the restricting member 81 is fixed to the fixed member 4 by a screw 9 having a central axis 90 aligned with the second rotation axis JJ2. Specifically, the fixed member 4 has an insertion hole 40 through which the screw 9 is inserted, and the restricting member 81 has a threaded hole 810 that opens to the lower surface and threads with the screw 9. The insertion hole 40 overlaps with the threaded hole 810, and the screw 9 is inserted through the insertion hole 40 from below and threadedly inserted into the threaded hole 810. This fixes the restricting member 81 to the fixed member 4. Therefore, when the screw 9 is loosened, the restricting member 81 becomes rotatable about the central axis 90, and conversely, when the screw 9 is tightened, the restricting member 81 is fixed to the fixed member 4 and cannot rotate about the central axis 90.

[0030] The regulating member 81 has a regulating portion 811 and a protruding portion 812 arranged along the central axis 90. The regulating portion 811 is arranged opposite the belt 36 across a gap, and the belt 36 comes into contact with the regulating portion 811 in the event of an abnormality, thereby restricting tooth skipping of the belt 36. By forming a gap, the belt 36 does not come into contact with the regulating portion 811 under normal conditions, thereby suppressing wear on the belt 36 and extending the life of the belt 36. Meanwhile, the protruding portion 812 is formed to protrude downward from the regulating portion 811 and is arranged to extend the regulating member 81 to the fixed member 4. In other words, the protruding portion 812 functions as a spacer that fills the gap between the regulating portion 811 and the fixed member 4. This makes it easier to fix the regulating member 81 to the fixed member 4.

[0031] Furthermore, both the restricting portion 811 and the protruding portion 812 are cylindrical, with the restricting portion 811 having a larger diameter than the protruding portion 812. By making the restricting portion 811 and the protruding portion 812 cylindrical in this way, they can be formed by cutting, and the restricting member 81 can be manufactured easily and inexpensively. However, the shapes of the restricting portion 811 and the protruding portion 812 are not particularly limited. The restricting portion 811 may have any shape, such as a triangular prism or an elliptical prism, as long as the separation distance DD from the belt 36 changes when the restricting portion 811 rotates about the central axis 90, as will be described later.

[0032] Further, while the central axis 812a of the protruding portion 812 coincides with the central axis 90, the central axis 811a of the restricting portion 811 is spaced apart from the central axis 90. That is, the restricting portion 811 is eccentric with respect to the central axis 90. Therefore, when the screw 9 is loosened and the restricting member 81 is rotated around the central axis 90 with respect to the fixing member 4, the restricting portion 811 eccentrically rotates around the central axis 90, whereby the separation distance DD between the restricting portion 811 and the belt 36 changes. By appropriately adjusting this separation distance DD, the tooth skipping of the belt 36 can be effectively restricted. Thus, by configuring the restricting portion 811 to be eccentrically rotatable around the central axis 90, the adjustment of the separation distance DD becomes easy. The separation distance DD is not particularly limited, but for example, it is preferably shorter than the meshing depth H between the belt 36 and the pulley 34. That is, it is preferably DD < H (see FIG. 4). Thereby, the tooth skipping of the belt 36 can be more effectively restricted.

[0033] Here, as shown in FIG. 5, the pulley 34 has a pair of flanges 341 and 342 located on both sides of the belt 36. The detachment of the belt 36 is restricted by these pair of flanges 341 and 342. When the separation distance between these flanges 341 and 342 is D and the length along the central axis 90 of the restricting portion 811 is L, the relationship D > L holds. Furthermore, the upper end of the restricting portion 811 is located below the upper flange 341, and the lower end is located above the lower flange 342. Therefore, the restricting portion 811 can enter between the flanges 341 and 342, and the adjustment range of the separation distance DD increases. However, it is not limited to this. For example, when the separation distance DD can be adjusted to an appropriate distance (for example, DD < H) even without allowing the restricting portion 811 to enter between the flanges 341 and 342, D ≦ L may be satisfied.

[0034] The power transmission mechanism 3 has been described above. Next, a method for adjusting the separation distance DD in this power transmission mechanism 3 will be described. This adjustment method will also be described focusing on the restriction member 81, and a description of the restriction member 82 will be omitted. As shown in FIG. 6 , the method for adjusting the separation distance DD includes an adjustment step S1 in which, with the screw 9 loosened, the restriction member 81 is rotated around the central axis 90 to adjust the separation distance DD to a predetermined distance, and a fixing step S2 in which the screw 9 is tightened to fix the restriction member 81 to the fixing member 4. This adjustment method makes it possible to easily adjust the separation distance DD. In particular, in this embodiment, the adjustment step S1 and the fixing step S2 are performed simultaneously in one step, as described below.

[0035] First, the screw 9 is loosened to allow the regulating member 81 to rotate around the central axis 90. Next, as shown in FIG. 7, a flat jig 10 is placed between the regulating portion 811 and the belt 36. The thickness of the jig 10 is designed to be equal to the target value of the separation distance DD. The jig 10 is made of a sufficiently hard material such as metal, and as will be described later, it will not substantially deform when sandwiched between the regulating portion 811 and the belt 36.

[0036] Next, as shown in Fig. 8, the screw 9 is tightened to fix the regulating member 81 to the fixed member 4. At this time, the frictional resistance generated at the threaded portion between the screw 9 and the regulating member 81 causes the regulating member 81 to rotate together with the screw 9, and the rotation of the regulating member 81 stops when the regulating portion 811 abuts against the jig 10 and the jig 10 is sandwiched between the regulating portion 811 and the belt 36. Then, if the screw 9 is tightened in this state, the regulating member 81 will be fixed to the fixed member 4 in this state, that is, with the jig 10 sandwiched between the regulating portion 811 and the belt 36. As can be seen from this process, the regulating member 81 is positioned so that the separation distance DD decreases as the regulating member 81 rotates in the screw tightening direction.

[0037] Finally, as shown in Fig. 9, when the jig 10 is removed from between the restricting portion 811 and the belt 36, a separation distance DD equal to the thickness of the jig 10 is formed. According to the adjustment method described above, the separation distance DD can be adjusted simply and accurately by simply placing the jig 10 and tightening the screws 9. In particular, in this embodiment, the adjustment step S1 and the fixing step S2 are performed simultaneously in one step, which reduces the number of adjustment steps and makes the adjustment easier.

[0038] The robot 100 has been described above. As described above, the robot 100 includes a motor 2 serving as a power source and a power transmission mechanism 3 that transmits the output of the motor 2. The power transmission mechanism 3 includes a fixed member 4, a pulley 34 serving as a first pulley that rotates around a second rotation axis JJ2 that is a first axis relative to the fixed member 4, a pulley 35 serving as a second pulley that is spaced apart from the pulley 34 and rotates around a third rotation axis JJ3 that is a second axis parallel to the second rotation axis JJ2 relative to the fixed member 4, 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 regulating member 81 that includes a regulating portion 811 that is disposed opposite the belt 36 across a gap at the portion where the pulley 34 and the belt 36 mesh, and a screw 9 whose central axis 90 is along the second rotation axis JJ2 and that fixes the regulating member 81 to the fixed member 4. In plan view from the direction along the second rotation axis JJ2, the rotation of the regulating member 81 around the central axis 90 changes the separation distance DD between the regulating portion 811 and the belt 36. With this configuration, the robot 100 can easily adjust the separation distance DD.

[0039] As described above, the separation distance DD is shorter than the meshing depth H between the pulley 34 and the belt 36. This makes it possible to more reliably prevent tooth skipping of the belt 36.

[0040] 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. This makes it possible to prevent the belt 36 from coming off the pulley 34.

[0041] As described above, the length L of the restricting portion 811 along the central axis 90 is shorter than the separation distance D between the pair of flanges 341, 342, and the restricting portion 811 enters between the pair of flanges 341, 342 by rotating around the central axis 90. This allows the separation distance DD to be adjusted without being obstructed by the flanges 341, 342.

[0042] As described above, the restricting portion 811 has a cylindrical shape and is disposed eccentrically with respect to the central axis 90. This allows the restricting portion 811 to be formed by cutting, making the manufacture of the restricting member 81 inexpensive and easy.

[0043] As described above, the restricting member 81 has a protruding portion 812 that protrudes from the restricting portion 811 and is located between the restricting portion 811 and the fixed member 4. Such a protruding portion 812 functions as a spacer between the restricting portion 811 and the fixed member 4. This makes it easier to fix the restricting member 81 to the fixed member 4.

[0044] As described above, the robot 100 includes the base 110, the first arm 121 connected to the base 110 and rotatable about the first rotation axis J1 relative to the base 110, the second arm 122 connected to the first arm 121 and rotatable about the second rotation axis J2 relative to the first arm 121, and the spline shaft 133 disposed on the second arm 122 and rotatable about the third rotation axis J3 relative to the second arm 122. The power transmission mechanism 3 transmits the output of the motor 2 to rotate the spline shaft 133 about the third rotation axis J3. With this configuration, the output of the motor 2 must be increased to increase the payload capacity of the robot 100. However, increasing the output of the motor 2 increases the likelihood of tooth skipping. Therefore, the effect of the restricting member 81 in restricting tooth skipping is more pronounced, thereby improving the driving characteristics of the robot 100.

[0045] As described above, the power transmission mechanism 3 includes the fixed member 4, the pulley 34 as a first pulley that rotates around the second rotation axis JJ2, which is a first axis relative to the fixed member 4, the pulley 35 as a second pulley that is arranged at a distance from the pulley 34 and rotates around the third rotation axis JJ3, which is a second axis parallel to the second rotation axis JJ2, relative to the fixed member 4, the 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, the regulating member 81 that has a regulating portion 811 that is arranged opposite the belt 36 across a gap at the portion where the pulley 34 and the belt 36 mesh, and a screw 9 whose central axis 90 is along the second rotation axis JJ2 and that fixes the regulating member 81 to the fixed member 4. In plan view from the direction along the second rotation axis JJ2, the rotation of the regulating member 81 around the central axis 90 changes the separation distance DD between the regulating portion 811 and the belt 36. With this configuration, the power transmission mechanism 3 can easily adjust the separation distance DD.

[0046] As described above, the adjustment method is performed by assembling the fixed member 4, the pulley 34 as a first pulley that rotates around the second rotation axis JJ2, which is a first axis, relative to the fixed member 4, the pulley 35 as a second pulley that is disposed apart from the pulley 34 and rotates around the third rotation axis JJ3, which is a second axis parallel to the second rotation axis JJ2, relative to the fixed member 4, and the pulley 34 and the pulley 35 as a second pulley. 5 a belt 36 that is wound around the pulley 34 and the pulley 35 and transmits the rotation of one of the pulleys 34 and 35 to the other; a regulating member 81 that has a regulating portion 811 that is arranged opposite the belt 36 across a gap at the portion where the pulley 34 and the belt 36 mesh; and a screw 9 that has a central axis 90 that is aligned with the second rotation axis JJ2 and that fixes the regulating member 81 to the fixed member 4. death, The adjustment method adjusts the separation distance DD between the restricting portion 811 and the belt 36 in the power transmission mechanism 3 in which the separation distance DD between the restricting portion 811 and the belt 36 changes as the restricting member 81 rotates about the central axis 90 in a plan view from the direction along the second rotation axis JJ2, and includes an adjusting step S1 in which the restriction member 81 is rotated about the central axis 90 with the screw 9 loosened to adjust the separation distance DD, and a fixing step S2 in which the screw 9 is tightened to fix the restriction member 81 to the fixed member 4. According to this method, the separation distance DD can be adjusted easily and accurately.

[0047] As described above, in the adjustment step S1, the jig 10 is placed between the restricting portion 811 and the belt 36, and the jig 10 is sandwiched between the restricting portion 811 and the belt 36, thereby adjusting the separation distance DD. According to this method, the thickness of the jig 10 is set to the target value of the separation distance DD, so that the separation distance DD can be easily adjusted to the target value. Therefore, the separation distance DD can be easily and accurately adjusted.

[0048] Furthermore, as described above, when the screw 9 is tightened to fix the restricting member 81 to the fixed member 4, the friction between the screw 9 and the restricting member 81 causes the restricting member 81 to rotate around the central axis 90 together with the screw 9, thereby simultaneously performing the adjustment step S1 and the fixing step S2. This reduces the number of adjustment steps, making the adjustment easier.

[0049] Second Embodiment FIG. 10 is a bottom view showing the power transmission mechanism of the second embodiment.

[0050] The robot 100 of this embodiment is the same as the first embodiment described above, except for the configuration of the power transmission mechanism 3. Therefore, in the following description, the differences between this embodiment and the first embodiment will be mainly described, and a description of the same points will be omitted. Furthermore, in each drawing of this embodiment, the same reference numerals are used to designate the same components as those in the above-described embodiment.

[0051] As shown in FIG. 10 , the power transmission mechanism 3 of this embodiment has a sensor 71 provided on the regulating member 81 that detects contact between the regulating portion 811 and the belt 36. This makes it possible to detect abnormalities in the power transmission mechanism 3 and can be used, for example, to determine whether maintenance is necessary. The sensor 71 is not particularly limited, and examples that can be used include a force sensor, a strain gauge, and a simple switch. In this embodiment, the sensor 71 is provided on the outer peripheral surface of the regulating portion 811, but the location of the sensor 71 is not particularly limited. The sensor 71 has been described above, but a similar sensor 72 is also provided on the regulating member 82.

[0052] As described above, the power transmission mechanism 3 of the present embodiment has the sensor 71 that detects contact between the regulating portion 811 and the belt 36. This makes it possible to detect an abnormality in the power transmission mechanism 3, and can be used as information for determining, for example, whether or not maintenance is required.

[0053] The second embodiment as described above can also achieve the same effects as the first embodiment.

[0054] <Third embodiment> FIG. 11 is a cross-sectional view showing a power transmission mechanism according to the third embodiment.

[0055] The robot 100 of this embodiment is similar to the first embodiment described above, except that the configurations of the regulating members 81 and 82 are different. Therefore, in the following description, the differences between this embodiment and the first embodiment will be mainly described, and a description of similar points will be omitted. Furthermore, in each drawing of this embodiment, the same components as those in the above-described embodiment are denoted by the same reference numerals. Furthermore, since the regulating members 81 and 82 have the same configuration, the following description will focus on the regulating member 81, and a description of the regulating member 82 will be omitted.

[0056] 11, the restricting member 81 is supported by the fixed member 4 on both sides in the direction along the central axis 90, i.e., on the upper end side and the lower end side. As a result, the restricting member 81 is supported at both ends by the fixed member 4, and the posture of the restricting member 81 is more stable compared to, for example, the first embodiment having a cantilever support structure. This improves the adjustment accuracy of the separation distance DD.

[0057] The restricting member 81 also has a restricting portion 811, a protruding portion 812 that protrudes downward from the restricting portion 811, and a protruding portion 813 that protrudes upward from the restricting portion 811. The protruding portion 813 is cylindrical like the protruding portion 812, and its central axis coincides with the central axis 90. In addition, instead of the screw holes 810, the restricting member 81 has insertion holes 814 that penetrate the upper and lower surfaces thereof and through which the screws 9 are inserted.

[0058] Furthermore, in addition to the insertion hole 40, the fixing member 4 is formed with a screw hole 42 that screws into the screw 9 at a position overlapping the insertion hole 40. The screw 9 is inserted from below through the insertion hole 40 and the insertion hole 814 and is screwed into the screw hole 42. As a result, the restricting member 81 is fixed in a state in which it is supported by the fixing member 4 at both ends.

[0059] In such a power transmission mechanism 3, the separation distance DD is adjusted as follows. First, the screw 9 is loosened to allow the regulating member 81 to rotate about the central axis 90. Next, a plate-shaped jig 10 is placed between the regulating portion 811 and the belt 36. Next, the regulating member 81 is rotated about the central axis 90 to sandwich the jig 10 between the regulating portion 811 and the belt 36. Next, while maintaining this state, the screw 9 is tightened to fix the regulating member 81 to the fixed member 4. Finally, the jig 10 is removed from between the regulating portion 811 and the belt 36. According to the adjustment method described above, the separation distance DD can be adjusted simply and accurately.

[0060] Thus, in the power transmission mechanism 3 of the present embodiment, the restricting member 81 is supported by the fixed member 4 on both sides in the direction along the central axis 90. As a result, the restricting member 81 is supported at both ends by the fixed member 4, and the posture of the restricting member 81 is more stable compared to, for example, the first embodiment having a cantilever support structure. This improves the adjustment accuracy of the separation distance DD.

[0061] The third embodiment as described above can also achieve the same effects as the first embodiment.

[0062] While the robot and adjustment method of the present invention have been described above based on the illustrated embodiment, the present invention is not limited to this, and the configuration of each part can be replaced with any configuration having a similar function. Furthermore, any other components may be added to the present invention. Furthermore, the power drive mechanism may be applied to any equipment other than a robot. [Explanation of symbols]

[0063] 10...jig, 100...robot, 110...base, 120...robot 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...fixing member, 40...insertion hole, 42...screw hole, 5...tooth skipping prevention mechanism, 71...sensor, 72...sensor, 81...regulating member, 810...screw hole, 811...regulating portion, 811a...central axis, 812...protruding portion, 812a...central axis, 813...protruding portion, 814...insertion hole, 82...regulating member, 9...screw, 90...central axis, A...arrow, B...arrow, BB...bearing, D...separation distance, DD...separation distance, H...engagement depth, J1...first rotating shaft, J2...second rotating shaft, J3...third rotating shaft, JJ1...first rotating shaft, JJ2...second rotating shaft, JJ3...third rotating shaft, L...length, S1...adjusting step, S2...fixing step, T1...second reducer, T2...second reducer

Claims

1. A base, a first arm connected to the base and rotatable about a first rotation axis relative to the base; a second arm connected to the first arm and rotating about a second rotation axis relative to the first arm; a spline shaft disposed on the second arm and rotating about a third rotation axis relative to the second arm, The second arm is A fixing member; a motor connected to the fixed member and having an output shaft; a first pulley connected to the output shaft of the motor and rotating about a first axis relative to the fixed member; a second pulley that is disposed apart from the first pulley, rotates relative to the fixed member about a second axis that is parallel to the first axis, and has an outer diameter larger than that of the first pulley; a first belt that is wound around the first pulley and the second pulley; a third pulley arranged alongside the second pulley in a direction along the second axis and rotating around the second axis relative to the fixed member; a fourth pulley that is disposed apart from the third pulley, that rotates relative to the fixed member about a third axis that is parallel to the second axis, and that has an outer diameter larger than that of the third pulley; a second belt that is wound around the third pulley and the fourth pulley; a bearing located between the second pulley and the third pulley; a regulating member including a regulating portion disposed opposite the second belt across a gap at a portion where the third pulley and the second belt mesh; a screw having a central axis aligned with the second axis and configured to fix the restricting member to the fixing member; When viewed from above in a direction along the second axis, the regulating member rotates around the central axis, thereby changing a distance between the regulating portion and the second belt, A horizontal articulated robot characterized in that the rotation direction of the screw in the direction of tightening the screw and the rotation direction of the regulating member in the direction of reducing the separation distance between the regulating portion and the second belt are the same.

2. The horizontal articulated robot according to claim 1 , wherein the separation distance is shorter than a depth of engagement between the third pulley and the second belt.

3. 3. The horizontal articulated robot according to claim 1, wherein the third pulley has a pair of flanges located on both sides of the second belt in a direction along the second axis.

4. The horizontal articulated robot according to claim 3 , wherein the length of the restricting portion along the central axis is shorter than the distance between the pair of flanges, and the restricting portion enters between the pair of flanges by rotating about the central axis.

5. 5. The horizontal articulated robot according to claim 1, wherein the restricting portion has a cylindrical shape and is disposed eccentrically with respect to the central axis.

6. The horizontal articulated robot according to claim 1 , wherein the regulating member has a protruding portion that protrudes from the regulating portion and is positioned between the regulating portion and the fixing member.

7. The horizontal articulated robot according to claim 6 , wherein the protrusion is cylindrical, and the central axis of the protrusion coincides with the central axis of the screw.

8. 8. The horizontal articulated robot according to claim 6, wherein the entire end surface of the protrusion on the fixed member side is in contact with the fixed member.

9. The horizontal articulated robot according to claim 1 , further comprising a sensor that detects contact between the regulating portion and the second belt.

10. 10. The horizontal articulated robot according to claim 1, wherein the regulating member is supported by the fixed member on both sides in a direction along the central axis.

11. A fixing member; a first pulley that rotates about a first axis relative to the fixed member; a second pulley disposed apart from the first pulley and configured to rotate relative to the fixed member about a second axis parallel to the first axis; a belt that is wound 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 regulating member including a regulating portion disposed opposite the belt across a gap at a portion where the first pulley and the belt mesh; a screw having a central axis aligned with the first axis and configured to fix the restricting member to the fixing member; an adjusting method for adjusting a separation distance between a regulating portion and a belt in a power transmission mechanism in which the separation distance between the regulating portion and the belt changes as the regulating member rotates around the central axis in a plan view from a direction along the first axis, adjusting the separation distance by rotating the restriction member around the central axis while the screw is loosened; and fastening the screw to fix the restricting member to the fixing member, In the adjusting step, a jig is disposed between the regulating portion and the belt, and the jig is sandwiched between the regulating portion and the belt, thereby adjusting the separation distance; When the screw is tightened to fix the regulating member to the fixed member, the friction between the screw and the regulating member causes the regulating member to rotate around the central axis together with the screw, thereby performing the adjusting step; thereafter, with the jig sandwiched between the regulating portion and the belt, the screw is further tightened to fix the regulating member to the fixed member; An adjustment method characterized in that the direction of rotation of the screw in the direction of tightening the screw and the direction of rotation of the regulating member in the direction of reducing the separation distance between the regulating portion and the belt are the same.

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