robot

Abstract

The present invention provides a robot that allows for easy adjustment of the tension of the annular member constituting the power transmission section. [Solution] The robot comprises a plurality of rotatably connected arms, a motor for rotationally driving the arms, a first rotational transmission member, a second rotational transmission member, and a first annular member wrapped around the first and second rotational transmission members, a power transmission unit arranged in the power transmission path from the motor to the arms and transmitting the rotational driving force of the motor, and a first adjustment unit that adjusts the tension of the first annular member by adjusting the distance between the first rotation axis of the first rotational transmission member and the second rotation axis of the second rotational transmission member, the arms having an arm base that houses the motor, the first rotational transmission member, the second rotational transmission member, and the first annular member, and the first adjustment unit is located outside the arm base.

Description

Technical Field

[0001] The present invention relates to a robot.

Background Art

[0002] In recent years, in factories, due to the soaring labor costs and labor shortages, robots having robot arms are used to perform operations such as material transportation, manufacturing, processing, and assembly, and the automation of operations that have been performed manually is being attempted.

[0003] For example, Patent Document 1 below discloses a robot that transmits the rotational driving force of a motor to an arm by a pulley-belt mechanism in which a belt is wound around a pair of pulleys. In this robot, a tensioner is pressed against a portion of the belt between the pair of pulleys, and the tension of the belt is adjusted by adjusting the degree of deflection of the belt. The tensioner is disposed inside the arm together with the pulley-belt mechanism.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in a winding transmission device in which an annular member is wound around a pair of rotary transmission members such as a pulley-belt mechanism, when an adjustment portion for the tension of the annular member is provided inside the arm, it is troublesome to operate the adjustment portion.

Means for Solving the Problems

[0006] The robot according to an application example of the present invention is a plurality of arms rotatably connected, and a motor that rotationally drives the arm A power transmission unit comprising a first rotation transmission member, a second rotation transmission member, and a first annular member wrapped around the first rotation transmission member and the second rotation transmission member, arranged in the power transmission path from the motor to the arm, and transmitting the rotational driving force of the motor, A first adjustment unit adjusts the tension of the first annular member by adjusting the distance between the first rotation axis of the first rotation transmission member and the second rotation axis of the second rotation transmission member, Equipped with, The arm has an arm base that houses the motor, the first rotation transmission member, the second rotation transmission member, and the first annular member. The first adjustment unit is located on the outside of the arm base. [Brief explanation of the drawing]

[0007] [Figure 1] This is a perspective view showing a robot and a robot system comprising the robot according to the first embodiment of the present invention. [Figure 2] This is a left side view showing a part of the robot in Figure 1. [Figure 3] This is a right side view showing a part of the robot in Figure 1. [Figure 4] This is a cross-sectional view along the line IV-IV in Figure 2. [Figure 5] This is a cross-sectional view along the VV line in Figure 1. [Figure 6] This is a cross-sectional view along the line VI-VI in Figure 1. [Figure 7] This is a cross-sectional view along the line VII-VII in Figure 2. [Figure 8] This is a left side view showing the adjustment section of the robot in Figure 1. [Figure 9] Figure 8 is a perspective view showing the adjustment section. [Figure 10] This is a left side view showing the adjustment section of the second embodiment. [Modes for carrying out the invention]

[0008] Embodiments of the present invention will be described below with reference to the drawings. Note that the following description does not limit the technical scope or the meaning of terms as defined in the claims. Furthermore, the dimensional ratios in the drawings are exaggerated for illustrative purposes and may differ from actual ratios.

[0009] <First Embodiment> Figure 1 is a perspective view showing a robot 10 and a robot system 1 comprising the robot 10 according to this embodiment. Figure 2 is a left side view showing a part of the robot 10 in Figure 1. Figure 3 is a right side view showing a part of the robot 10 in Figure 1. Figure 4 is a cross-sectional view along the line IV-IV in Figure 2. Figure 5 is a cross-sectional view along the line VV in Figure 1. Figure 6 is a cross-sectional view along the line VI-VI in Figure 1. Figure 7 is a cross-sectional view along the line VII-VII in Figure 2.

[0010] For the sake of clarity, in the following diagrams, the x, y, and z axes are represented by arrows as three mutually orthogonal axes. In this embodiment, the x-axis is an axis along one of the horizontal directions, the y-axis is an axis along a direction perpendicular to the x-axis in the horizontal direction, and the z-axis is an axis along the vertical direction. The tip of each arrow shown is referred to as the "positive side (+)" and the base end as the "negative side (-)". The z-axis direction + is referred to as "up" or "upward", and the z-axis direction - is referred to as "down" or "downward".

[0011] Furthermore, in this specification, descriptions such as "orthogonal," "parallel," "same position, height, dimensions, etc.," and "symmetrical" all mean that they are "orthogonal," "parallel," "same position, height, dimensions, etc.," and "symmetrical" to a degree that allows for manufacturing tolerances. Specifically, "orthogonal" means substantially orthogonal, and includes the range in which the angle between two lines or two planes is 80 degrees or more and 100 degrees or less. "Parallel" means substantially parallel, and includes the range in which the angle between two lines or two planes is 0 degrees or more and 10 degrees or less. "Same dimensions" means that the two dimensions are substantially the same, and includes the range in which the error between the two dimensions is ±10%. "Symmetrical" means substantially symmetrical, and includes the range in which, when one of the two elements is superimposed on the other, the ratio of the overlapping area to the total area of ​​the other is 90% or more and 100% or less.

[0012] In Figure 7, the second motor 151, located on the y-axis side of the cross-section in Figure 7, is hypothetically shown by a dashed line.

[0013] Robot 10 in robot system 1 is a parallel link type robot and is used in the broad sense of food manufacturing, including, for example, food handling, food plating, food packaging, and food processing. In this case, the workpiece (object to be worked on) in robot system 1 is food or food packaging. However, the application of robot system 1 and the type of workpiece are not limited to the above.

[0014] Referring to Figure 1, the robot system 1 comprises a robot 10 and a control device 20 that controls the operation of each part of the robot 10. The robot 10 has a base 110 on which a drive unit 140 is provided, and a robot arm 200 that is rotatably connected to the base 110 via joints 125 and rotates relative to the base 110 by the drive of the drive unit 140. The robot arm 200 includes a plurality of arms 121, 122, 123, 124 that are sequentially rotatably connected, a plurality of joints 126, 127, 128, link mechanisms 131, 132, and a plurality of drive units 150, 160, 170. The parts of the robot system 1 will be described in detail below.

[0015] The base 110 is a support that supports the robot arm 200. The base 110 is installed on a horizontal plane (installation surface) parallel to the x-y plane, such as the floor or ceiling of a factory.

[0016] Hereinafter, the arm 121 of the robot arm 200 will also be referred to as the "first arm 121", the arm 122 as the "second arm 122", the arm 123 as the "third arm 123", and the arm 124 as the "fourth arm 124". Also, the joint 125 will be referred to as the "first joint 125", the joint 126 as the "second joint 126", the joint 127 as the "third joint 127", and the joint 128 as the "fourth joint 128". Further, in the robot 10, the robot arm 200, each of the arms 121, 122, 123, 124, etc., the side of the base 110 is also referred to as the "base end side" or "base end portion", and the opposite side is also referred to as the "tip side" or "tip portion".

[0017] The shapes of the first arm 121, the second arm 122, the third arm 123, and the fourth arm 124 are not particularly limited, but in this embodiment, the overall shapes are each long and similar shapes without being particularly defined.

[0018] The first arm 121 is provided above the base 110 along a first axis A1 parallel to the z-axis direction. The base end portion (lower end portion) of the first arm 121 is rotatably connected to the base 110 via the first joint 125 around the first axis A1. When the first arm 121 rotates in a predetermined direction with respect to the base 110 by the drive of the drive unit 140, the entire robot arm 200, that is, the first arm 121 and the second joint 126, the second arm 122, the third joint 127, the third arm 123, the fourth joint 128, the fourth arm 124, the link mechanisms 131, 132, etc. provided on the tip side of the first arm 121, rotate counterclockwise or clockwise around the first axis A1.

[0019] The base end of the second arm 122 is rotatably connected to the tip (upper end) of the first arm 121 via the second joint 126, around the second axis A2 which extends in a direction nonparallel to the first axis A1, and in this embodiment in a direction perpendicular to the first axis A1 (the x-axis direction when the rotation angle of the first arm 121 is as shown in Figure 1). The second arm 122 extends along the direction perpendicular to the second axis A2.

[0020] The portion of the third arm 123 between its base and tip is rotatably connected to the tip of the second arm 122 via a third joint 127, so as to be around a third axis A3 parallel to the second axis A2. The third arm 123 extends in a direction perpendicular to the third axis A3.

[0021] The base end of the fourth arm 124 is connected to the tip of the third arm 123 via the fourth joint 128, so as to be rotatable (oscillating) around the fourth axis A4 which is parallel to the second axis A2.

[0022] An end effector E1 is detachably provided at the tip of the fourth arm 124 for holding a workpiece (e.g., food) by gripping or suction. The end effector E1 is mounted on the tip of the fourth arm 124 so as to be rotatable around a fifth axis A5 parallel to the z-axis direction. The end effector E1 may or may not be a component of the robot 10.

[0023] Hereinafter, the direction along the first axis A1 will also be referred to as the "first direction D1," the direction along the second axis A2 will also be referred to as the "second direction D2," and the direction perpendicular to the first direction D1 and the second direction D2 will also be referred to as the "third direction D3." In this embodiment, the first direction D1 coincides with the z-axis direction. In this embodiment, the second direction D2 and the third direction D3 are directions parallel to the xy-plane, and their orientation changes with the rotation of the first arm 121. The first direction D1, the second direction D2, and the third direction D3 are illustrated with arrows in each figure. For the first direction D1, the second direction D2, and the third direction D3, the tip of each arrow will be referred to as the "positive side (+ side)," and the base end as the "negative side (- side)."

[0024] The drive unit 140 rotates the first arm 121. Hereinafter, the drive unit 140 will also be referred to as the "first drive unit 140". The drive unit 150 rotates the second arm 122. Hereinafter, the drive unit 150 will also be referred to as the "second drive unit 150". The drive unit 160 rotates the third arm 123. Hereinafter, the drive unit 160 will also be referred to as the "third drive unit 160". The second drive unit 150 and the third drive unit 160 are installed on the first arm 121. The drive unit 170 rotates the end effector E1. Hereinafter, the drive unit 170 will also be referred to as the "fourth drive unit 170". The fourth drive unit 170 is installed on the fourth arm 124.

[0025] The first drive unit 140 and the fourth drive unit 170 each include a motor and a power transmission unit that transmits the rotational driving force (hereinafter simply referred to as "power") of the motor, although these are not shown. The drive of each motor is controlled by a control device 20, which will be described later, via a motor driver, which is not shown. The power transmission unit preferably includes a reduction gear that transmits the power of the motor at a reduced rotational speed. Examples of reduction gears include gear devices such as planetary gears and harmonic drive gears, and winding transmission devices. A winding transmission device is a device that transmits power by wrapping an annular member around a pair of rotational transmission members. Examples of combinations of rotational transmission members and annular members include a pulley-belt mechanism in which the rotational transmission member is composed of a pulley and the annular member is composed of a belt, a sprocket-chain mechanism in which the rotational transmission member is composed of a sprocket and the annular member is composed of a chain, and a wheel-wire mechanism in which the rotational transmission member is composed of a wheel and the annular member is composed of a wire. Details of the configuration of the second drive unit 150 and the third drive unit 160 will be described later.

[0026] The link mechanism 131 transmits the power output by the third drive unit 160 to the third arm 123. As shown in Figure 2, the link mechanism 131 includes a plate-shaped link 131a, a rod-shaped link 131b, a pivot 131c, and a pivot 131d.

[0027] As will be described in detail later, the base end of link 131a is positioned on the second axis A2, and link 131a extends in a direction perpendicular to the second axis A2 and rotates around the second axis A2 independently of the second arm 122 by the drive of the third drive unit 160. The tip of link 131a is rotatably connected to the base end of link 131b via pivot 131c around an axis parallel to the second axis A2. The tip of link 131b is rotatably connected to the base end of the third arm 123 via pivot 131d around an axis parallel to the second axis A2.

[0028] The length of the line L1 connecting the second axis A2 and the central axis of pivot 131c is the same as the length of the line L2 connecting the third axis A3 and the central axis of pivot 131d. The distance between the second axis A2 and the third axis A3 is the same as the distance between the central axis of pivot 131c and the central axis of pivot 131d. Therefore, when viewed from the second direction D2 (the x-axis direction in the state shown in Figure 2), the second axis A2, the central axis of pivot 131c, the central axis of pivot 131d, and the third axis A3 form a parallelogram.

[0029] Therefore, when viewed from the second direction D2, the line L1 is parallel to the line L2. Consequently, when the link 131a rotates due to the drive of the third drive unit 160, the line L1 also rotates accordingly, and the third arm 123 rotates around the third axis A3 so that the line L2 becomes parallel to the line L1.

[0030] As shown in Figure 1, the link mechanism 132 is provided on the second direction D2+ side of the link mechanism 131. The link mechanism 132 maintains a constant posture of the fourth arm 124 so that the fifth axis A5, which is the rotation axis of the end effector E1 mounted on the fourth arm 124, is always parallel to the z-axis direction. As shown in Figure 3, the link mechanism 132 has a rod-shaped link 132a, a plate-shaped link 132b, a rod-shaped link 132c, a pivot 132d, a pivot 132e, a pivot 132f, and a pivot 132g. The shape of link 132b in plan view is a triangle with rounded corners, but is not limited to this.

[0031] Link support members 121e are provided at the ends of the first arm 121 on the second direction D2+ side and the third direction D3+ side (the ends opposite to the side facing the fourth arm 124), projecting above the upper end of the first arm 121. The base end of the link 132a is rotatably connected by a pivot 132d to the tip (upper end) of the link support member 121e around a rotation axis parallel to the second axis A2.

[0032] The tip of link 132a and one corner of link 132b are rotatably connected by pivot 132e around an axis of rotation parallel to the second axis A2. The other corner of the plate-shaped link 132b and the base end of link 132c are rotatably connected by pivot 132f around an axis of rotation parallel to the second axis A2. The tip of link 132c and the portion of the base end of the fourth arm 124 separated from the fourth joint 128 are rotatably connected by pivot 132g around an axis of rotation parallel to the second axis A2. The remaining corner of link 132b is rotatably connected to the third arm 123 via the third joint 127 around the third axis A3.

[0033] The length of the line L3 connecting the second axis A2 and the central axis of pivot 132d is the same as the length of the line L4 connecting the third axis A3 and the central axis of pivot 132e. The distance between the second axis A2 and the third axis A3 is the same as the distance between the central axis of pivot 132d and the central axis of pivot 132e. Therefore, when viewed from the second direction D2 (the x-axis direction in the state shown in Figure 3), line L3 is parallel to line L4.

[0034] Furthermore, the length of the line L5 connecting the third axis A3 and the central axis of pivot 132f is the same as the length of the line L6 connecting the fourth axis A4 and the central axis of pivot 132g. The distance between the third axis A3 and the fourth axis A4 is the same as the distance between the central axis of pivot 132f and the central axis of pivot 132g. Therefore, when viewed from the second direction D2 (the x-axis direction in the state shown in Figure 3), line L5 is parallel to line L6.

[0035] The angle of line L3 with respect to the xy-plane does not change with the rotation angles (positions) of the second arm 122 and the third arm 123. Therefore, the angle of line L4 with respect to the xy-plane remains constant. Consequently, the position of link 132b also remains constant. Consequently, the angle of line L5 with respect to the xy-plane also remains constant. Therefore, the angle of line L6 with respect to the xy-plane also remains constant. Thus, the position of the fourth arm 124 is kept constant regardless of the rotation angles (positions) of the second arm 122 and the third arm 123.

[0036] As described above, by controlling the rotation angles of the first arm 121, the second arm 122, and the third arm 123, the position of the end effector E1 in the xyz coordinate system can be adjusted while keeping the fifth axis A5, which is the rotation axis of the end effector E1, parallel to the z-axis direction. Furthermore, by rotating the end effector E1 around the fifth axis A5, the workpiece held by the end effector E1 can be rotated. Note that the specific shapes of each arm 121, 122, 123, 124, link mechanism 131, and link mechanism 132 are not particularly limited to the shapes shown in the figure.

[0037] As shown in Figure 1, the control device 20 is connected to the robot 10 by wire or wireless means to enable the transmission and reception of signals, and controls the operation of each part of the robot 10. The control device 20 includes a processor such as a CPU (Central Processing Unit), a storage unit composed of volatile memory such as RAM (Random Access Memory), non-volatile memory such as ROM (Read Only Memory), and a communication unit that transmits and receives signals with the robot 10. In this embodiment, the control device 20 is located outside the robot 10. However, the control device 20 may be installed on a base 110 or the like.

[0038] Next, the first arm 121, the second joint 126, the second drive unit 150, and the third drive unit 160 will be described in detail.

[0039] The first arm 121 has an arm base 121a on which the second drive unit 150 and the third drive unit 160 are installed.

[0040] As shown in Figure 1, the arm base 121a includes a bottom plate portion 121b having an upper surface parallel to the xy plane, and a pair of side plate portions 121c and 121d connected to both ends of the bottom plate portion 121b in a second direction D2 and extending along the z axis. The arm base 121a is a housing that has an open upper surface (a surface parallel to the xy plane), and a shape in which parts of the positive and negative sides of the third direction D3 (surfaces parallel to the xz plane), which are perpendicular to the side plate portions 121c and 121d, are open. Inside the housing, a space is formed that can accommodate the main parts of the second drive unit 150 and the third drive unit 160.

[0041] As shown in Figure 4, the shape of the base plate portion 121b in a top view is a rectangle with rounded corners. In this embodiment, the first axis A1 is located at the center of the base plate portion 121b in a top view.

[0042] One side plate portion 121c is connected to the end of the bottom plate portion 121b on the second direction D2- side. One side plate portion 121c has a flat main body portion 121f parallel to the first direction D1 and the third direction D3, and a pair of protrusions 121g projecting from both ends of the main body portion 121f in the third direction D3 toward the other side plate portion 121d.

[0043] The other side plate portion 121d is connected to the end of the bottom plate portion 121b on the second direction D2+ side. The other side plate portion 121d has a shape that coincides with the other side plate portion 121c when rotated 180 degrees around the first axis A1 as the central axis. In other words, the pair of side plate portions 121c and 121d are rotationally symmetric with respect to the first axis A1. Therefore, parts of the same shape can be used for the pair of side plate portions 121c and 121d.

[0044] However, the shape of the arm base 121a of the first arm 121 is not limited to the above. For example, the arm base 121a may further have a front plate portion attached to the end of the bottom plate portion 121b on the third direction D3- side and extending in the z-axis direction, or a back plate portion attached to the end of the bottom plate portion 121b on the third direction D3+ side and extending in the z-axis direction. Also, the arm base 121a may be formed by integrally forming the bottom plate portion 121b, the side plate portion 121c, and the side plate portion 121d, for example, by forming a desired shape from a single metal plate by press working or the like. Furthermore, the first axis A1 may be located off-center from the center when viewed from above the first arm 121.

[0045] As shown in Figure 7, the second joint 126, which connects the second arm 122 to the first arm 121 so as to be rotatable around the second axis A2, is provided on the upper part of a pair of side plate portions 121c and 121d. The second joint 126 has a shaft 126a provided along the second axis A2, a bearing portion 126b that rotatably holds one end of the shaft 126a, and a bearing portion 126c that rotatably holds the other end of the shaft 126a.

[0046] The shaft 126a is located in the center of the bottom plate portion 121b in the third direction D3 when viewed from the first direction D1 (z-axis direction), and extends along the second direction D2 from one side plate portion 121c to the other side plate portion 121d. Therefore, in this embodiment, the second axis A2, which is the central axis of the shaft 126a, is perpendicular to the first axis A1. The base end of the second arm 122 is fixed to the portion of the shaft 126a between the pair of side plate portions 121c and 121d, and the second arm 122 rotates in conjunction with the shaft 126a. Each bearing portion 126b, 126c includes a bearing whose inner ring is fixed to the outer circumference of the shaft 126a, and a bearing holder that holds the outer ring of the bearing and is attached to the arm base 121a of the first arm 121. The bearing portion 126b is attached to the upper part of the side plate portion 121c of the first arm 121. The bearing portion 126c is attached to the upper part of the side plate portion 121d of the first arm 121.

[0047] Furthermore, a through hole 131h is formed at the base end of the link 131a of the link mechanism 131, with a diameter larger than the diameter of the shaft 126a, and passing through the link 131a in the thickness direction. The link 131a is positioned on the second direction D2+ side of the second arm 122, spaced apart from the second arm 122, with the shaft 126a inserted through the through hole 131h.

[0048] Furthermore, a second drive unit 150 and a third drive unit 160 are installed on the arm base 121a of the first arm 121. The second drive unit 150 includes a second motor 151, a second power transmission unit 152 that transmits power from the second motor 151 to the shaft 126a, and adjustment units 157 and 158. Adjustment unit 157 corresponds to the first adjustment unit, and adjustment unit 158 ​​corresponds to the second adjustment unit. Similarly, the third drive unit 160 includes a third motor 161, a third power transmission unit 162 that transmits power from the third motor 161 to the link 131a of the link mechanism 131, and adjustment units 167 and 168.

[0049] As shown in Figure 4, the second motor 151 and the third motor 161 are positioned between a pair of side plates 121c and 121d, and on the bottom plate 121b. That is, the second motor 151 and the third motor 161 are housed in the arm base 121a. However, parts of the second motor 151 and the third motor 161 may protrude outside the arm base 121a.

[0050] The second motor 151 includes a rotor and stator (not shown), a second output shaft 151a fixed to the rotor, and a second housing 151b that houses the rotor and stator and exposes the tip of the second output shaft 151a. As shown in Figure 7, the second motor 151 is mounted on the upper surface of the bottom plate portion 121b via a mount 151c. As shown in Figures 1, 2, and 4, the second motor 151 is installed such that the second output shaft 151a extends along the second direction D2 and the second output shaft 151a protrudes from the second housing 151b toward the second direction D2-. Furthermore, the second motor 151 is positioned toward the third direction D3- side of the second axis A2 when viewed from the first direction D1 (z-axis direction).

[0051] Similarly, the third motor 161 includes a rotor and stator (not shown), a third output shaft 161a fixed to the rotor, and a third housing 161b that houses the rotor and stator and exposes the tip of the third output shaft 161a. As shown in Figure 7, the third motor 161 is mounted on the upper surface of the bottom plate portion 121b via a mount 161c. As shown in Figures 3 and 4, the third motor 161 is installed such that the third output shaft 161a extends along the second direction D2 and the third output shaft 161a protrudes from the third housing 161b toward the second direction D2+. Furthermore, the third motor 161 is positioned toward the third direction D3+ side than the second axis A2 when viewed from the first direction D1 (z-axis direction).

[0052] However, the configuration and arrangement of the second motor 151 and the third motor 161 are not limited to those described above.

[0053] In this embodiment, the second power transmission section 152 of the second drive unit 150 includes a reduction gear that transmits the power of the second motor 151 at a reduced rotational speed. In this embodiment, the reduction gear is composed of a multi-stage reduction type winding transmission device, more specifically a multi-stage reduction type pulley-belt mechanism. If a gear device were used as the reduction gear, it would be necessary to periodically apply lubricating oil between the gears to suppress gear wear. In contrast, if a pulley-belt mechanism is used as the reduction gear, it is not necessary to apply lubricating oil between the pulley and the belt. Therefore, maintenance of the robot 10 is made easier, and it is possible to suppress the leakage or scattering of lubricating oil from the robot 10 and contaminating the workpiece or installation surface. As mentioned above, if the workpiece is food or food packaging, the adhesion or contamination of lubricating oil must be avoided, and separate sufficient preventive measures would be necessary, but in this embodiment, such measures are not necessary or simpler measures suffice.

[0054] Furthermore, winding drive systems are lighter and less expensive compared to gear systems such as planetary gears and harmonic drive gears. Therefore, the robot arm 200 can be made lighter and the robot 10 can be made less expensive. As the robot arm 200 becomes lighter, the inertial force during rotational drive of the first arm 121 and other components of the robot arm 200 is reduced, allowing the rotational drive of the first arm 121 and other components to be performed at a higher speed, thereby improving work efficiency by increasing the work speed.

[0055] Specifically, as shown in Figure 5, the second power transmission unit 152, as a reduction gear, includes an input-side rotational transmission member 153a provided on the second output shaft 151a, a first-stage rotating shaft 153s positioned diagonally upward from the second output shaft 151a, an output-side rotational transmission member 153b provided on the first-stage rotating shaft 153s, and an annular member 153c wrapped around the input-side rotational transmission member 153a and the output-side rotational transmission member 153b. Hereinafter, these will also be referred to as the "first-stage reduction gear." The input-side rotational transmission member 153a is a small-diameter pulley, the output-side rotational transmission member 153b is a large-diameter pulley with a diameter greater than that of the input-side rotational transmission member 153a, and the annular member 153c is an endless belt. The first-stage rotating shaft 153s corresponds to the first rotating shaft.

[0056] Furthermore, the second power transmission unit 152, as a reduction gear, includes an input-side rotational transmission member 154a provided on the first-stage rotating shaft 153s, a second-stage rotating shaft 154s located above the first-stage rotating shaft 153s, an output-side rotational transmission member 154b provided on the second-stage rotating shaft 154s, and an annular member 154c wrapped around the input-side rotational transmission member 154a and the output-side rotational transmission member 154b. Hereinafter, these will also be referred to as the "second-stage reduction gear." The input-side rotational transmission member 154a is a small-diameter pulley with the same diameter as the input-side rotational transmission member 153a of the first stage. The output-side rotational transmission member 154b is a large-diameter pulley with the same diameter as the output-side rotational transmission member 153b of the first stage. The annular member 154c is an endless belt with the same width, thickness, and circumference as the annular member 153c of the first stage. The second stage input-side rotational transmission member 154a corresponds to the first rotational transmission member, the output-side rotational transmission member 154b corresponds to the second rotational transmission member, and the rotational shaft 154s corresponds to the second rotational shaft.

[0057] Furthermore, the second power transmission unit 152, as a reduction gear, includes an input-side rotational transmission member 155a provided on the second-stage rotating shaft 154s, an output-side rotational transmission member 155b provided on the shaft 126a of the second joint 126, and an annular member 155c wrapped around the input-side rotational transmission member 155a and the output-side rotational transmission member 155b. Hereinafter, these will also be referred to as the "third-stage reduction gear." The input-side rotational transmission member 155a is a small-diameter pulley, the output-side rotational transmission member 155b is a large-diameter pulley with a diameter greater than the diameter of the input-side rotational transmission member 155a, and the annular member 155c is an endless belt. As shown in Figure 7, the output-side rotational transmission member 155b is provided between the second arm 122 and the side plate portion 121c. Furthermore, the third-stage input-side rotational transmission member 155a corresponds to the third rotational transmission member, the output-side rotational transmission member 155b corresponds to the fourth rotational transmission member, and the shaft 126a corresponds to the third rotation axis.

[0058] The diameter of the third-stage input-side rotational transmission member 155a is greater than the diameter of the first-stage input-side rotational transmission member 153a. The diameter of the third-stage output-side rotational transmission member 155b is greater than the diameter of the first-stage output-side rotational transmission member 153b. The width of the third-stage annular member 155c is greater than the width of the first-stage annular member 153c, and the thickness of the third-stage annular member 155c is greater than the thickness of the first-stage annular member 153c.

[0059] The end of the first stage rotating shaft 153s on the second direction D2- side is provided with a bearing portion 153t that rotatably holds the first stage rotating shaft 153s. The bearing portion 153t is provided on an adjustment portion 157 that adjusts the tension of the second stage annular member 154c. Details of the bearing portion 153t and the adjustment portion 157 will be described later. The first stage rotating shaft 153s has the first stage output side rotation transmission member 153b and the second stage input side rotation transmission member 154a provided on it, spaced apart from each other, in order toward the second direction D2+ side.

[0060] Similarly, the end of the second stage rotating shaft 154s on the second direction D2- side is provided with a bearing portion 154t that rotatably holds the second stage rotating shaft 154s. The bearing portion 154t is provided in the adjustment portion 158 that adjusts the tension of the third stage annular member 155c. Details of the bearing portion 154t and the adjustment portion 158 will be described later. The second stage rotating shaft 154s has the input side rotation transmission member 155a of the third stage and the output side rotation transmission member 154b of the second stage provided on it, spaced apart from each other, in the direction of the second direction D2+.

[0061] Furthermore, the input-side rotational transmission members 153a, 154a, 155a, output-side rotational transmission members 153b, 154b, 155b, and annular members 153c, 154c, 155c that constitute the second power transmission unit 152 are all positioned between the pair of side plate portions 121c, 121d of the first arm 121. In other words, they are housed in the arm base 121a of the first arm 121. Therefore, even if foreign matter such as shavings of the annular members 153c, 154c, 155c are scattered from the second power transmission unit 152, the side plate portions 121c, 121d function as protective walls, suppressing the scattering of foreign matter outside the arm base 121a. As mentioned above, when the workpiece is food or food packaging, the adhesion or contamination of foreign matter must be avoided, so applying the robot 10 with the above configuration to food manufacturing is meaningful.

[0062] As a result, when the second output shaft 151a rotates due to the drive of the second motor 151, the first stage input-side rotation transmission member 153a of the second power transmission unit 152 rotates in conjunction with it. In conjunction with this, the first stage annular member 153c, the output-side rotation transmission member 153b, the first stage rotating shaft 153s, and the second stage input-side rotation transmission member 154a rotate. Further in conjunction with this, the second stage annular member 154c, the output-side rotation transmission member 154b, the rotating shaft 154s, and the third stage input-side rotation transmission member 155a rotate. Further in conjunction with this, the third stage annular member 155c, the output-side rotation transmission member 155b, and the shaft 126a of the second joint 126 rotate. As a result, the second arm 122 rotates.

[0063] Similarly, the third power transmission unit 162 includes a reduction gear that reduces and transmits the rotational speed of the third motor 161. In this embodiment, the reduction gear is composed of a multi-stage reduction type winding transmission device, more specifically a multi-stage reduction type pulley-belt mechanism.

[0064] Specifically, as shown in Figure 6, the third power transmission unit 162, as a reduction gear, includes an input-side rotational transmission member 163a provided on the third output shaft 161a of the third motor 161, a first-stage rotating shaft 163s located diagonally upward from the third output shaft 161a, an output-side rotational transmission member 163b provided on the first-stage rotating shaft 163s, and an annular member 163c wrapped around the input-side rotational transmission member 163a and the output-side rotational transmission member 163b. Hereinafter, these will also be referred to as the "first-stage reduction gear".

[0065] Furthermore, the third power transmission unit 162, as a reduction gear, includes an input-side rotational transmission member 164a provided on the first-stage rotating shaft 163s, a second-stage rotating shaft 164s located above the first-stage rotating shaft 163s, an output-side rotational transmission member 164b provided on the second-stage rotating shaft 164s, and an annular member 164c wrapped around the input-side rotational transmission member 164a and the output-side rotational transmission member 164b. Hereinafter, these will also be referred to as the "second-stage reduction gear."

[0066] Furthermore, the third power transmission unit 162, as a reduction gear, includes an input-side rotational transmission member 165a provided on the second-stage rotating shaft 164s, an output-side rotational transmission member 165b provided on the shaft 126a of the second joint 126 via a bearing portion 166, and an annular member 165c wrapped around the input-side rotational transmission member 165a and the output-side rotational transmission member 165b. Hereinafter, these will also be referred to as the "third-stage reduction gear." As shown in Figure 7, the output-side rotational transmission member 165b is provided between the link 131a and the side plate portion 121d.

[0067] In this embodiment, the bearing section 166 is composed of two bearings 166a. The outer ring of each bearing 166a is fixed to the inner circumferential surface of the output-side rotation transmission member 165b, and the inner ring of each bearing 166a is fixed to the outer circumferential surface of the shaft 126a of the second joint 126. In addition, the link 131a is fixed to the side surface of the output-side rotation transmission member 165b. As a result, the link 131a rotates in conjunction with the third drive unit 160, independently of the rotation of the shaft 126a of the second joint 126.

[0068] The end of the first stage rotating shaft 163s on the second direction D2+ side is provided with a bearing portion 163t that rotatably holds the first stage rotating shaft 163s. The bearing portion 163t is provided on an adjustment portion 167 that adjusts the tension of the second stage annular member 164c. Details of the bearing portion 163t and the adjustment portion 167 will be described later. The first stage rotating shaft 163s is provided with the first stage output side rotation transmission member 163b and the second stage input side rotation transmission member 164a, spaced apart from each other, in order toward the second direction D2- side.

[0069] Similarly, the end of the second stage rotating shaft 164s on the second direction D2+ side is provided with a bearing portion 164t that rotatably holds the second stage rotating shaft 164s. The bearing portion 164t is provided in the adjustment portion 168 that adjusts the tension of the third stage annular member 165c. Details of the bearing portion 164t and the adjustment portion 168 will be described later. The second stage rotating shaft 164s has the input side rotation transmission member 165a of the third stage and the output side rotation transmission member 164b of the second stage provided on it, spaced apart from each other, in the direction of the second direction D2-.

[0070] The input-side rotational transmission members 163a, 164a, 165a, output-side rotational transmission members 163b, 164b, 165b, and annular members 163c, 164c, 165c that constitute the third power transmission section 162 are all positioned between the pair of side plate portions 121c, 121d of the first arm 121. In other words, they are housed in the arm base 121a of the first arm 121.

[0071] As a result, when the third output shaft 161a rotates due to the drive of the third motor 161, the first stage input-side rotation transmission member 163a rotates in conjunction with it. In conjunction with this, the first stage annular member 163c, the output-side rotation transmission member 163b, the first stage rotating shaft 163s, and the second stage input-side rotation transmission member 164a rotate. Further in conjunction with this, the second stage annular member 164c, the output-side rotation transmission member 164b, the rotating shaft 164s, and the third stage input-side rotation transmission member 165a rotate. Further in conjunction with this, the third stage annular member 165c and the output-side rotation transmission member 165b rotate. As a result, the link 131a of the link mechanism 131 rotates.

[0072] Thus, both the second power transmission unit 152 and the third power transmission unit 162 are composed of a three-stage reduction pulley-belt mechanism. In this embodiment, the second power transmission unit 152 and the third power transmission unit 162 use the same type of input-side rotational transmission members (small diameter pulleys), output-side rotational transmission members (large diameter pulleys), annular members (belts), and bearings, which are located in the same stage.

[0073] In other words, the input-side rotational transmission members (small-diameter pulleys) located on the same stage in the second power transmission unit 152 and the third power transmission unit 162 are identical in terms of pulley type (such as V-pulleys and toothed pulleys), dimensions (such as diameter and width), and material. Similarly, the output-side rotational transmission members (large-diameter pulleys) located on the same stage in the second power transmission unit 152 and the third power transmission unit 162 are identical in terms of pulley type (such as V-groove belts and toothed belts (cogged belts)), dimensions (such as width, thickness, and circumference), and material.

[0074] However, the configuration of the second power transmission unit 152 and the third power transmission unit 162 is not limited to the above. For example, the reduction gear may be other winding transmission devices such as a sprocket-chain mechanism or a wheel-wire mechanism. Also, the second power transmission unit 152 and the third power transmission unit 162 may not include a reduction gear and may transmit the power output by the second motor 151 and the third motor 161 without reduction. Furthermore, the type, type, performance, dimensions, etc. of corresponding components in the second power transmission unit 152 and the third power transmission unit 162 may differ.

[0075] Next, the bearing sections 153t, 154t, 163t, 164t, and the adjustment sections 157, 158, 167, 168 will be described in detail. Hereafter, bearing sections 153t and 163t will also be referred to as "first-stage bearing sections 153t and 163t," and bearing sections 154t and 164t will also be referred to as "second-stage bearing sections 154t and 164t." Similarly, adjustment sections 157 and 167 will also be referred to as "first-stage adjustment sections 157 and 167," and adjustment sections 158 and 168 will also be referred to as "second-stage adjustment sections 158 and 168."

[0076] As shown in Figure 7, the first stage bearing section 153t of the second power transmission section 152 rotatably supports one end of the first stage rotating shaft 153s. The other end of the rotating shaft 153s is a free end. The bearing section 153t includes bearings 61 and 62, whose inner rings are fixed to the rotating shaft 153s, and a cylindrical bearing holder 63 into which the bearings 61 and 62 are fitted and which holds the outer rings of the bearings 61 and 62.

[0077] Bearing 61 is provided at the end of the rotating shaft 153s on the second direction D2- side. Bearing 62 is spaced apart from bearing 61 on the second direction D2+ side and is positioned between bearing 61 and the first stage output-side rotation transmission member 153b.

[0078] The bearing holder 63 includes a first cylindrical portion 63a into which a bearing 61 is fitted, a second cylindrical portion 63b into which a bearing 62 is fitted, and a third cylindrical portion 63c located between the first cylindrical portion 63a and the second cylindrical portion 63b. The inner diameter of the first cylindrical portion 63a and the inner diameter of the second cylindrical portion 63b are the same and larger than the inner diameter of the third cylindrical portion 63c. The outer diameter of the first cylindrical portion 63a and the outer diameter of the second cylindrical portion 63b are the same and smaller than the outer diameter of the third cylindrical portion 63c.

[0079] The rotating shaft 153s is cantilevered by the bearing portion 153t. Therefore, the first stage adjustment portion 157, described later, allows rotation of the rotating shaft 153s while easily adjusting the position of the rotating shaft 153s in the first direction D1 with a simple structure.

[0080] A cylindrical member 67 is provided between bearing 61 and bearing 62, which abuts against the inner rings of bearing 61 and bearing 62. Furthermore, the rotating shaft 153s has a step located on the second direction D2+ side of the inner ring of bearing 62, which abuts against the inner ring of bearing 62. Additionally, by pressing a cylindrical member (not shown) against the inner ring of bearing 61 from the second direction D2- side and fixing it in place, preload can be applied to the inner rings of bearings 61 and 62. As a result, even with a cantilever support, the bearing holder 63 can reliably hold bearings 61 and 62 with a simple configuration, suppressing axial runout of the rotating shaft 153s.

[0081] The other bearing sections 154t, 163t, and 164t have the same components as bearing section 153t. That is, each bearing section 154t, 163t, and 164t also has bearings 61 and 62 whose inner rings are fixed to the corresponding rotating shaft, and a cylindrical bearing holder 63 into which bearings 61 and 62 are fitted and which holds the outer rings of bearings 61 and 62. Bearing sections 154t, 163t, and 164t also have the same functions and effects as bearing section 153t described above.

[0082] The second bearing portion 154t of the second power transmission unit 152 is positioned in the same orientation as the first bearing portion 153t. The first bearing portion 163t of the third power transmission unit 162 is positioned in the same orientation as the first bearing portion 153t of the second power transmission unit 152, rotated 180 degrees around the first shaft A1 as the central axis. Similarly, the second bearing portion 164t of the third power transmission unit 162 is positioned in the same orientation as the second bearing portion 154t of the second power transmission unit 152, rotated 180 degrees around the first shaft A1 as the central axis.

[0083] One side plate portion 121c has a through hole 64a that penetrates the side plate portion 121c in the thickness direction and in which the second cylindrical portion 63b of the first stage bearing holder 63 of the second power transmission portion 152 is positioned, and a through hole 64b that penetrates the side plate portion 121c in the thickness direction and in which the second cylindrical portion 63b of the second stage bearing holder 63 is positioned. The diameters of each through hole 64a and 64b are larger than the diameters of each second cylindrical portion 63b.

[0084] Similarly, the other side plate portion 121d has a through hole 65a that penetrates the other side plate portion 121d in the thickness direction and into which the second cylindrical portion 63b of the first stage bearing holder 63 of the third power transmission portion 162 is positioned, and a through hole 65b that penetrates the side plate portion 121c in the thickness direction and into which the second cylindrical portion 63b of the second stage bearing holder 63 is positioned. The diameters of each through hole 65a and 65b are larger than the diameters of each second cylindrical portion 63b.

[0085] The first-stage adjustment unit 157 of the second drive unit 150 holds the first-stage bearing 153t and adjusts the position of the bearing 153t in the first direction D1. This adjusts the distance ΔL21 between the first-stage rotating shaft 153s, on which the second-stage input-side rotation transmission member 154a is provided, and the second-stage rotating shaft 154s, on which the second-stage output-side rotation transmission member 154b is provided. As a result, the tension of the second-stage annular member 154c is adjusted. In this specification, "distance between axes" refers to the distance between the central axes (rotational central axes) of both shafts.

[0086] Similarly, the second stage adjustment section 158 of the second drive unit 150 holds the second stage bearing section 154t and adjusts the position of the bearing section 154t in the first direction D1. This adjusts the distance ΔL31 between the second stage rotating shaft 154s, on which the third stage input-side rotation transmission member 155a is provided, and the shaft 126a of the second joint 126, on which the third stage output-side rotation transmission member 155b is provided. As a result, the tension of the third stage annular member 155c is adjusted.

[0087] The tension of the first annular member 153c can be adjusted, for example, by using the mount 151c as a motor position adjustment unit and adjusting the position of the second motor 151 using the mount 151c.

[0088] Let's consider a case where a tensioner is provided in the second annular member 154c, located between the input-side rotation transmission member 154a and the output-side rotation transmission member 154b. By pressing this tensioner against the annular member 154c to adjust the degree of deflection of the annular member 154c, the tension of the annular member 154c is adjusted without changing the interaxial distance ΔL21. In such a case, the tensioner needs to be positioned between the input-side rotation transmission member 154a and the output-side rotation transmission member 154b, and therefore the input-side rotation transmission member 154a and the output-side rotation transmission member 154b need to be separated by a sufficiently long distance in the first direction D1. For this reason, the arm base 121a becomes larger in the first direction D1. Furthermore, space is needed to install the tensioner and its moving and pressing mechanism on the side of the annular member 154c in the third direction D3, so the arm base 121a also becomes larger in the third direction D3.

[0089] In contrast, in this embodiment, the first-stage adjustment unit 157 adjusts the tension of the annular member 154c by holding the first-stage bearing unit 153t and adjusting the interaxial distance ΔL21. Since the first-stage adjustment unit 157 is positioned approximately coaxially with the rotating shaft 153s, the arm base 121a can be miniaturized in the first direction D1. Furthermore, since the installation space for the tensioner and its moving and pressing mechanism is not required, the arm base 121a can be miniaturized in the third direction D3.

[0090] Figure 8 is a left side view showing the adjustment units 157 and 158 of the robot 10 in Figure 1. Figure 9 is a perspective view showing the adjustment unit 157 in Figure 8.

[0091] As shown in Figure 8, the first adjustment section 157 is provided on the outer side surface of the side plate portion 121c of the arm base 121a. The adjustment section 157 includes a rotating member 71 that is rotatable around a pivot point R2 located away from the center R1 of the bearing portion 153t, a fixing member 72 that is located away from the rotating member 71 downward (towards the first direction D1-) and fixed to the outer side surface of the side plate portion 121c, and a screw member 73 that is screwed into the fixing member 72, contacts the rotating member 71, and rotates to rotate the rotating member 71 around the pivot point R2 and adjust the distance between the axes ΔL21.

[0092] As shown in Figure 9, the rotating member 71 includes a flat rotating body portion 74 parallel to the side surface of the side plate portion 121c, and a plate-shaped rotating upright portion 75 connected to the lower end (first direction D1-side) of the rotating body portion 74 and projecting in the direction toward the rotating body portion 74 from the side plate portion 121c (second direction D2-side). Such a rotating member 71 can be made, for example, by bending a single plate or by welding two plates together.

[0093] As shown in Figure 8, the rotating body portion 74 extends in the third direction D3, straddling the first axis A1 when viewed from the second direction D2. A through hole (not shown) is formed at the end of the rotating body portion 74 on the third direction D3 side. A pivot member 74a, such as a screw or pin, is fixed to the side plate portion 121c with the screw or pin inserted through this through hole. As a result, the rotating member 71 rotates along the outer side surface of the side plate portion 121c, with the central axis of the pivot member 74a as the pivot point R2.

[0094] As shown in Figures 7 and 8, a holder insertion hole 74b is formed approximately in the center of the rotating body 74 in the third direction D3, penetrating the rotating body 74 in the thickness direction, and through which the second cylindrical portion 63b of the first-stage bearing holder 63 can be inserted. The bearing holder 63 is fixed to the rotating body 74 by multiple screws or the like with the holder insertion hole 74b inserted through it. As a result, the first-stage bearing portion 153t and the rotating shaft 153s rotate around the pivot point R2 in conjunction with the rotating member 71. Consequently, the position of the first-stage rotating shaft 153s in the first direction D1 changes. In addition, the first cylindrical portion 63a and the third cylindrical portion 63c of the bearing portion 153t are located outside the arm base 121a. In this way, at least a part of the bearing portion 153t is located outside the arm base 121a, so lubricating oil can be easily supplied to the bearings 61 and 62 of the bearing portion 153t. Furthermore, by injecting lubricating oil through the gap between the inner and outer rings of the outer bearing 61, sufficient lubricating oil can be supplied to the inner bearing 62. Also, the entire bearing portion 153t may be exposed to the outside.

[0095] As shown in Figure 8, the rotating body portion 74 has through holes 74h1, 74h2, 74h3, 74h4, 74h5, and 74h6, which are multiple elongated holes that penetrate the rotating body portion 74 in the thickness direction. These through holes 74h1, 74h2, 74h3, 74h4, 74h5, and 74h6 are formed in an arc shape centered on the pivot point R2.

[0096] In the third direction D3, the positions of the through holes 74h1 and 74h2 are between the position of the first-stage bearing portion 153t and the position of the pivot point R2. Hereafter, when viewed from the second direction D2, the straight line connecting the center R1 of the bearing portion 153t and the pivot point R2 will be called "straight line L74". When viewed from the second direction D2, the through holes 74h1 and 74h2 are formed on opposite sides of each other with straight line L74 as the boundary line. Furthermore, when viewed from the second direction D2, the through holes 74h1 and 74h2 are symmetrical with respect to straight line L74.

[0097] The through holes 74h3 and 74h4 are located between the bearing portion 153t and the end of the rotating body portion 74 on the third direction D+ side. Viewed from the second direction D2, the through holes 74h3 and 74h4 are formed on opposite sides of each other with respect to the straight line L74. Furthermore, viewed from the second direction D2, the through holes 74h3 and 74h4 are symmetrical with respect to the straight line L74. The arc lengths of the arc-shaped through holes 74h3 and 74h4 are longer than the arc lengths of the arc-shaped through holes 74h1 and 74h2.

[0098] The through holes 74h5 and 74h6 are located between the through holes 74h3 and 74h4 and the end of the rotating body portion 74 on the third direction D+ side. Viewed from the second direction D2, the through holes 74h5 and 74h6 are formed on opposite sides of each other with respect to the straight line L74. Furthermore, viewed from the second direction D2, the through holes 74h5 and 74h6 are symmetrical with respect to the straight line L74. The arc lengths of the arc-shaped through holes 74h5 and 74h6 are longer than the arc lengths of the arc-shaped through holes 74h3 and 74h4.

[0099] Each of the through holes 74h1, 74h2, 74h3, 74h4, 74h5, and 74h6 is screwed into the side plate portion 121c with each screw 74c inserted through it. By loosening each screw 74c from the side plate portion 121c, the rotating member 71 becomes rotatable within the range restricted by the multiple through holes 74h1, 74h2, 74h3, 74h4, 74h5, and 74h6. Then, by tightening each screw 74c from the side plate portion 121c, the rotating member 71 becomes fixed to the side plate portion 121c. Thus, in this embodiment, the rotating member 71 is fixed to the side plate portion 121c at six points, but the number of fixing points is not limited to six; it may be one to five points, or seven or more points.

[0100] The rotating upright portion 75 extends from the end of the rotating main body portion 74 on the third direction D3+ side toward the third direction D3- side. As shown in Figure 9, the rotating upright portion 75 has a through hole 75h that penetrates the rotating upright portion 75 in the thickness direction (first direction D1). The through hole 75h is an elongated hole that extends in the third direction D3. As shown in Figure 8, when viewed from the second direction D2, the through hole 75h is located on the third direction D3+ side of the center R1 of the first stage bearing portion 153t.

[0101] As shown in Figure 9, the fixing member 72 is separated from the rotating member 71 downward (towards the first direction D1-). The fixing member 72 includes a flat fixing body portion 76 parallel to the side surface of the side plate portion 121c, and a fixing upright portion 77 connected to the upper end (towards the first direction D1+) of the fixing body portion 76 and projecting in the direction toward the fixing body portion 76 from the side plate portion 121c (towards the second direction D2-). Such a fixing member 72 can be made, for example, by bending a single plate or by welding two plates together.

[0102] The fixed main body portion 76 is fixed to the side plate portion 121c by multiple screws. The fixed upright portion 77 faces the rotating upright portion 75 in the first direction D1. The fixed upright portion 77 has a screw hole 77h that penetrates the fixed upright portion 77 in the thickness direction (first direction D1). The through hole 75h of the rotating upright portion 75 and the screw hole 77h of the fixed upright portion 77 partially overlap when viewed from the first direction D1.

[0103] In this embodiment, the threaded member 73 extends in a first direction D1 and includes a male threaded portion 73a that screws into the threaded hole 77h of the fixed upright portion 77 and passes through the through hole 75h of the rotating upright portion 75, a screw head 73b provided at the upper end of the male threaded portion 73a and located above the rotating upright portion 75, and a washer 73c located between the screw head 73b and the rotating upright portion 75 and in contact with the upper surface of the rotating upright portion 75. The washer 73c is inserted through the male threaded portion 73a. The inner diameter of the washer 73c is smaller than the screw head 73b, and the outer diameter of the washer 73c is larger than the width of the through hole 75h of the rotating upright portion 75 in a second direction D2.

[0104] As shown in Figure 8, when viewed in the direction in which the first rotation axis 153s extends (second direction D2), the pivot point R2, the fixing member 72, and the screw member 73 are located on opposite sides of each other, with the straight line L95 passing through the first rotation axis 153s and the second rotation axis 154s as the boundary.

[0105] On the outer side surface of the side plate portion 121c, there is a mark 91 indicating the position of the rotating member 71 such that a predetermined tension is applied to the second annular member 154c. Here, "predetermined tension" refers to a tension such that, for example, the tension of the annular member 154c is insufficient, preventing it from slipping (free-spinning) relative to the input-side rotation transmission member 154a and the output-side rotation transmission member 154b, or conversely, the tension of the annular member 154c is excessive, preventing it from hindering the rotation of the input-side rotation transmission member 154a and the output-side rotation transmission member 154b. In other words, "predetermined tension" is a tension within an appropriate range that allows the power of the motor 151 to be transmitted with high efficiency.

[0106] The appropriate tension range varies depending on the conditions of the belt used as the annular member 154c, such as the type of belt, width, thickness, material, elasticity, and other configuration and characteristics. Users may select and use belts with different conditions depending on their purpose. Furthermore, the appropriate tension range also differs depending on the weight of the robot arm 200 and the weight of the workpiece held by the end effector E1. Therefore, in this embodiment, multiple marks 91 are provided in the rotational direction of the rotating member 71. That is, a scale 92 is provided on the outer side surface of the side plate portion 121c to indicate the position of the rotating member 71 in steps, corresponding to the tension of the second annular member 154c. This allows the position of the rotating member 81 to be adjusted to a position where appropriate tension is applied to the annular member 154c, corresponding to the configuration of the second annular member 154c and the weight of the workpiece, etc.

[0107] Next, the method of adjusting using the first-stage adjustment section 157 will be explained. For example, when replacing the second-stage annular member 154c, the user performs the following steps. First, the user loosens each screw 74c that fixes the rotating body 74. Next, the user rotates the screw member 73 in a way that loosens it relative to the fixed upright section 77. As a result, the screw head 73b moves upward (towards the first direction D1+) along with the male screw portion 73a. Then, the gap between the screw head 73b and the upper surface of the rotating upright section 75 widens.

[0108] Next, the user rotates the rotating member 71 around the pivot point R2 in a direction that separates it from the fixed member 72 (clockwise in Figure 8). This moves the first stage rotating shaft 153s upward, and the distance ΔL21 between the first stage rotating shaft 153s and the second stage rotating shaft 154s decreases. As a result, the distance between the input-side rotation transmission member 154a and the output-side rotation transmission member 154b decreases, and the tension of the second stage annular member 154c (see Figure 7) decreases. Consequently, the annular member 154c can be easily removed from the second stage input-side rotation transmission member 154a and the output-side rotation transmission member 154b. Note that during this operation, the output-side rotation transmission member 153b moves upward along with the rotating shaft 153s, so the tension of the annular member 153c increases slightly, but this is not a problem as it returns to normal when the rotating member 71 is rotated counterclockwise in Figure 8.

[0109] Next, the user wraps the new annular member 154c around the second stage input-side rotation transmission member 154a and output-side rotation transmission member 154b. Then, the user rotates the screw member 73 to tighten it against the fixed upright portion 77. This causes the screw head 73b to move downward (towards the first direction D1-) along with the male screw portion 73a. As a result, the screw head 73b presses against the washer 73c. ​​The washer 73c is in contact with the upper surface of the rotating upright portion 75 and pushes the rotating upright portion 75 downward. As a result, the rotating member 71 rotates around the pivot point R2 in a direction approaching the fixed member 72 (counterclockwise in Figure 8), and the first stage rotation axis 153s moves downward. With this movement, the distance between the input-side rotation transmission member 154a and the output-side rotation transmission member 154b increases, and the tension of the annular member 154c increases. Then, the position of the rotating member 71 is adjusted to the position of the mark 91 which represents the desired tension. While maintaining this state, the user tightens each screw 74c of the rotating member 71 against the side plate portion 121c. This fixes the position of the rotating member 71 relative to the side plate portion 121c. In this way, the tension of the new annular member 154c can be adjusted to a predetermined tension that allows for proper power transmission while replacing the annular member 154c with a new one.

[0110] Furthermore, the removal of the annular member 154c and the installation of a new annular member 154c can be performed by passing it through the gaps between the ends of the rotating shafts 153s and 163s, and the gaps between the ends of the rotating shafts 154s and 164s, which are located on the first axis A1.

[0111] Thus, since the adjustment unit 157 is located on the outside of the arm base 121a, the user can easily operate the adjustment unit 157. On the other hand, since the main parts of the second motor 151 and the second power transmission unit 152 are housed in the arm base 121a of the first arm 121, contact between the main parts of the second motor 151 and the second power transmission unit 152 and surrounding objects can be suppressed. Furthermore, if a predetermined tension is to be applied to the second annular member 154c, the rotating member 71 can be positioned to the desired tension using the mark 91 provided on the outer side surface of the arm base 121a. Therefore, there is no need to measure the tension of the annular member 154c inside the arm base 121a with a measuring instrument, and the predetermined tension, i.e., the appropriate tension, can be easily applied to the annular member 154c.

[0112] Furthermore, when the annular member 154c is wrapped around the input-side rotation transmission member 154a and the output-side rotation transmission member 154b and tensioned, the distance between the axes ΔL21 is increased as described above. In this case, as the distance between the axes ΔL21 increases, the tension applied to the annular member 154c increases, but at the same time, the reaction force that the annular member 154c applies to the rotating member 71 via the rotating shaft 153s and the bearing portion 153t also increases. The reaction force is a force in the direction that reduces the distance between the axes ΔL21, that is, in the direction that moves the rotating member 71 away from the fixed member 72. When the distance between the axes ΔL21 is increased, the screw member 73 is in contact with the upper surface of the rotating upright portion 75, so this reaction force can be absorbed by the fixed member 72 via the screw member 73. Therefore, the force required by the user to increase the distance between the axes ΔL21 can be reduced.

[0113] Furthermore, the contact point between the screw member 73 and the rotating member 71 corresponds to the point where the user applies force to increase the interaxial distance ΔL21, and the center R1 of the first-stage bearing portion 153t corresponds to the point where the reaction force of the annular member 154c acts. The distance between the point of application of force and the fulcrum R2 is longer than the distance between the point of application and the fulcrum R2. Therefore, when increasing the interaxial distance ΔL21, the force applied by the user to the point of application of force is less than the reaction force from the annular member 154c acting on the point of application. Thus, the force required by the user to increase the interaxial distance ΔL21 can be reduced.

[0114] The second-stage adjustment unit 158 ​​has the same main components as the first-stage adjustment unit 157, but the arrangement and orientation of each component are different. In the following, for the second-stage adjustment unit 158, the same names will be used for components that are the same as those in the first-stage adjustment unit 157, and explanations will be omitted as appropriate. The differences from the first-stage adjustment unit 157 will be the main focus of the explanation. Furthermore, the operation method for adjustment using the adjustment unit 158 ​​is almost the same as the operation method for adjustment using the adjustment unit 157 described above, so a detailed explanation will be omitted.

[0115] The second adjustment section 158 is located above the adjustment section 157 and is provided on the outer side surface of the side plate portion 121c of the arm base 121a. The second adjustment section 158 includes a rotating member 81 that is rotatable around a pivot point R4 located away from the center R3 of the second bearing portion 154t, a fixing member 82 that is located away from the rotating member 81 upward (towards the first direction D1+) and is fixed to the outer side surface of the side plate portion 121c, and a screw member 83 that is screwed into the fixing member 82, contacts the rotating member 81, and rotates to rotate the rotating member 81 around the pivot point R2 to adjust the distance between the axes ΔL31.

[0116] The rotating member 81 has a shape obtained by rotating the rotating member 71 of the first stage adjustment section 157 by 180 degrees in a plane that includes the first direction D1 and the third direction D3. Therefore, in the rotating member 81, the pivot point R4 is located on the third direction D3+ side of the center R3 of the second stage bearing section 154t. In addition, the rotating upright section 85 of the rotating member 81 is connected to the upper (first direction + side) end of the rotating main body section 84. Furthermore, the through hole 85h formed in the rotating upright section 85 is located on the third direction D3- side of the center R3 of the bearing section 154t.

[0117] The fixing member 82 has a shape obtained by rotating the fixing member 72 of the first stage adjustment section 157 by 180 degrees in a plane that includes the first direction D1 and the third direction D3. Furthermore, the fixing member 82 is fixed to the side plate section 121c while being spaced upward (towards the first direction D1+) from the rotating member 81 and positioned on the third direction D3- side of the bearing section 126b of the second joint 126.

[0118] The fixed upright portion 87 of the fixing member 82 is connected to the lower end (first direction D1-side) of the fixing main body portion 86, and a screw hole 87h is formed that penetrates the fixed upright portion 87 in the thickness direction (first direction D1). The through hole 85h of the rotating upright portion 85 and the screw hole 87h of the fixed upright portion 87 partially overlap when viewed from the first direction D1.

[0119] In this embodiment, the threaded member 83 extends in a first direction D1 and includes a male threaded portion 83a that screws into the threaded hole 87h of the fixed upright portion 87 and passes through the through hole 85h of the rotating upright portion 75, a threaded head 83b provided at the upper end of the male threaded portion 83a and located above the fixed upright portion 87, and a nut 83c located between the fixed upright portion 87 and the rotating upright portion 85 and in contact with the upper surface of the rotating upright portion 85. The nut 83c is fixed to the male threaded portion 83a while inserted through it. The outer diameter of the nut 83c is greater than the width of the through hole 85h of the rotating upright portion 85 in a second direction D2. Note that the outer diameter of the nut 83c refers to the diameter of the inscribed circle of the nut 83c.

[0120] Looking in the direction in which the second stage rotation axis 154s extends (second direction D2), the pivot point R4, the fixing member 82, and the screw member 83 are located on opposite sides of each other, with the straight line L95 passing through the second stage rotation axis 154s and the shaft 126a as the boundary. Specifically, looking in the second direction D2, with the straight line L95 as the boundary, the fixing member 72 of the first stage, the screw member 73, and the pivot point R4 of the second stage are located on one side (third direction D3+ side), while the pivot point R2 of the first stage, the fixing member 82, and the screw member 83 are located on the other side (third direction D3- side). Also, the direction from the rotating member 71 of the first stage toward the fixing member 72 is the opposite direction to the direction from the rotating member 81 of the second stage toward the fixing member 82. This allows the arm base 121a to be miniaturized in the direction in which the input side rotation transmission member 154a and the output side rotation transmission member 154b are aligned (first direction D1).

[0121] When the user loosens the threaded member 83 from the fixed upright portion 87 to reduce the distance between the axes ΔL31, the nut 83c moves upward (towards the first direction D1+) along with the male threaded portion 83a. As a result, the nut 83c moves away from the rotating upright portion 85. Therefore, the user can rotate the rotating member 81 around the pivot point R4 in a direction approaching the fixed member 82 (counterclockwise in Figure 8). Consequently, the rotating shaft 154s and the input-side rotation transmission member 155a move upward, and the tension of the annular member 155c decreases.

[0122] On the other hand, if the user tightens the threaded member 83 against the fixed upright portion 87 to increase the distance between axes ΔL31, the nut 83c moves downward (towards the first direction D1-) together with the male threaded portion 83a. As a result, the nut 83c comes into contact with the rotating upright portion 85, and the rotating member 81 rotates (clockwise in Figure 8) in a direction that moves away from the fixed member 82 around the pivot point R4. Consequently, the rotating shaft 154s and the input side rotation transmission member 155a move downward, and the tension of the annular member 155c increases.

[0123] On the outer side surface of the side plate portion 121c, there is a mark 93 indicating the position of the rotating member 81 such that a predetermined tension is applied to the third annular member 155c. In this embodiment, there are multiple marks 93 in the rotational direction of the rotating member 81. That is, on the outer side surface of the side plate portion 121c, there is a scale 94 that indicates the position of the rotating member 81 in steps, corresponding to the tension applied to the third annular member 155c.

[0124] When operating the adjustment unit 158, the output-side rotation transmission member 154b also moves upward or downward along with the rotation shaft 154s. Therefore, if an annular member 154c is wrapped between the output-side rotation transmission member 154b and the input-side rotation transmission member 154a, the tension of the annular member 154c will also change. Accordingly, it is preferable to appropriately combine the adjustment by the adjustment unit 157 and the adjustment by the adjustment unit 158 ​​to balance the tension of the annular member 154c and the tension of the annular member 155c.

[0125] As shown in Figure 7, the first stage adjustment unit 167 of the third drive unit 160 holds the first stage bearing 163t and adjusts the position of the first stage bearing 163t in the first direction D1. This adjusts the distance ΔL22 between the first stage rotating shaft 163s, on which the second stage input-side rotation transmission member 164a is provided, and the second stage rotating shaft 164s, on which the second stage output-side rotation transmission member 164b is provided. As a result, the tension of the second stage annular member 164c is adjusted.

[0126] As shown in Figure 3, the first-stage adjustment section 167 has the same components as the first-stage adjustment section 157 of the second drive unit 150. That is, the first-stage adjustment section 167 has a rotating member 71, a fixed member 72, and a screw member 73. As shown in Figure 7, when viewed from the third direction D3, the first-stage adjustment section 167 of the third drive unit 160 is the same assembly as the first-stage adjustment section 157 of the second drive unit 150 rotated 180 degrees around the first axis A1 as the central axis. The method of operation for adjustment using the adjustment section 167 is almost the same as the method of operation for adjustment using the adjustment section 157 described above, so a detailed explanation is omitted.

[0127] Similarly, the second stage adjustment section 168 of the third drive unit 160 holds the second stage bearing section 164t and adjusts the position of the second stage bearing section 164t in the first direction D1. This adjusts the distance ΔL32 between the second stage rotating shaft 164s, on which the third stage input-side rotation transmission member 165a is provided, and the shaft 126a, on which the third stage output-side rotation transmission member 165b is provided. As a result, the tension of the third stage annular member 165c is adjusted.

[0128] As shown in Figure 3, the second stage adjustment section 168 has the same components as the second stage adjustment section 158 of the second drive unit 150. That is, the second stage adjustment section 168 has a rotating member 81, a fixed member 82, and a screw member 83. As shown in Figure 7, when viewed from the third direction D3, the second stage adjustment section 168 of the third drive unit 160 is the same assembly as the second stage adjustment section 158 of the second drive unit 150 rotated 180 degrees around the first axis A1 as the central axis. The method of operation for adjustment using the adjustment section 168 is almost the same as the method of operation for adjustment using the adjustment section 158 described above, so a detailed explanation is omitted.

[0129] Furthermore, the tension of the first annular member 163c of the third power transmission unit 162 can be adjusted, for example, by making the mount 161c function as a motor position adjustment unit and adjusting the position of the third motor 161 using the mount 161c.

[0130] Therefore, the same assembly can be used for one side plate section 121c, the second power transmission section 152, the first stage adjustment section 157, and the second stage adjustment section 158, and for the other side plate section 121d, the third power transmission section 162, the first stage adjustment section 167, and the second stage adjustment section 168. This reduces the number of parts that need to be prepared to manufacture the robot 10 during production, allowing for efficient manufacturing of the robot 10. As a result, the productivity of the robot 10 is improved. Furthermore, during use, the number of parts that need to be prepared for replacement of deteriorated or malfunctioning parts is reduced, simplifying the maintenance of the robot 10.

[0131] The configuration of the adjustment unit 157 is not limited to the above. For example, the adjustment unit 157 may adjust the distance ΔL21 between axes not by rotating the bearing unit 153t around the pivot point R2, but by moving the bearing unit 153t linearly along the first direction D1, the third direction D3, and directions intersecting these directions. The same applies to the other adjustment units 158, 167, and 168. Furthermore, the specific configurations of the rotating members 71, 81, the fixed members 72, 82, and the screw members 73, 83 are not limited to the above. For example, the rotating members 71, 81 and the fixed members 72, 82 may be block-shaped instead of plate-shaped.

[0132] Furthermore, the robot system 1 may be equipped with a tension measuring device capable of measuring the tension of the annular members 154c, 155c, 164c, and 165c, and a display unit that displays the detected value of the tension measuring device, allowing the user to adjust the positions of the rotating members 71 and 81 according to the detected value displayed on the display unit. In this case, the control device 20 may present an appropriate tension range to the user via the display unit based on information about the configuration and characteristics of the annular members 154c, 155c, 164c, and 165c, such as their type, width, thickness, material, and elastic force, as well as information about the weight of the workpiece. Examples of tension measuring devices include ultrasonic types and acceleration sensor types.

[0133] Furthermore, the reasons and timing for operating the adjustment units 157, 158, 167, and 168 are not limited to those described above. Adjustment unit 157 may be used, for example, to adjust (restore) the tension of the annular member 154c, etc., when it has loosened due to reasons such as when it is used to manufacture heavy workpieces, when the robot arm 200 is operated continuously at a relatively high speed, when the robot 10 is used for a long period of time, or when the temperature, humidity, etc. of the environment in which the robot 10 is installed rises or falls and load is placed on the annular member 154c, etc., or when repairing, reinforcing, or replacing the annular member 154c, etc. Adjustment unit 157 may also be used to adjust the tension of the annular member 154c in accordance with changes in the weight of the workpiece held by the end effector E1. This ensures that the robot 10 operates more appropriately according to the weight of the workpiece, etc. The same applies to the other adjustment units 158, 167, and 168.

[0134] Furthermore, if the power transmission section of the first drive unit 140 is configured as a winding transmission device, the adjustment sections 157 and 158 may be applied to the first drive unit 140. This allows for adjustment of the distance between the axes of a pair of rotational transmission members constituting the winding transmission device of the first drive unit 140, and adjustment of the tension of the annular member wrapped around the pair of rotational transmission members. In this case, the adjustment section is provided on the outside of the base 110, such as on the top surface or side of the base 110.

[0135] As described above, the robot 10 comprises a plurality of rotatably connected arms 121, 122, 123, and 124, a motor 151 that rotationally drives arm 122, a power transmission unit 152 positioned in the power transmission path from motor 151 to arm 122 and transmitting the rotational driving force of motor 151, and an adjustment unit 157 (first adjustment unit). The power transmission unit 152 has a first rotational transmission member 154a, a second rotational transmission member 154b, and a first annular member 154c wrapped around the first rotational transmission member 154a and the second rotational transmission member 154b. The first adjustment unit 157 adjusts the tension of the first annular member 154c by adjusting the distance ΔL21 between the first rotation axis 153s of the first rotational transmission member 154a and the second rotation axis 154s of the second rotational transmission member 154b. The arm 121 has an arm base 121a that houses the motor 151, the first rotation transmission member 154a, the second rotation transmission member 154b, and the first annular member 154c. The first adjustment unit 157 is located on the outside of the arm base 121a.

[0136] Thus, since the first adjustment unit 157 is located on the outside of the arm base 121a, the user can easily adjust the tension of the first annular member 154c. On the other hand, since the arm base 121a houses the motor 151, the first rotation transmission member 154a, the second rotation transmission member 154b, and the first annular member 154c, contact between these components and surrounding objects can be suppressed.

[0137] Furthermore, the first adjustment unit 157 allows for a smaller arm base 121a compared to the case where a tensioner is used to adjust the degree of deflection of the first annular member 154c by pressing the portion of the first annular member 154c between the first rotation transmission member 154a and the second rotation transmission member 154b to adjust the interaxial distance ΔL21.

[0138] Furthermore, the power transmission unit 152 further has a bearing portion 153t that rotatably supports one end of the first rotating shaft 153s, and the first adjustment unit 157 is installed on the side of the arm base 121a so that the position of the bearing portion 153t relative to the arm base 121a can be adjusted.

[0139] Therefore, the first adjustment unit 157 can be positioned outside the arm base 121a while allowing rotation of the first rotation axis 153s.

[0140] Furthermore, at least a portion of the bearing portion 153t is located outside the arm base 121a.

[0141] Therefore, maintenance of the bearing portion 153t, such as injecting lubricating oil into the bearings 61, 61 of the bearing portion 153t, can be easily performed.

[0142] The first adjustment unit 157 also includes a rotating member 71, a fixed member 72, and a screw member 73. The rotating member 71 holds the bearing portion 153t and is mounted on the side surface of the arm base 121a so as to be rotatable around a pivot point R2 located away from the center R1 of the bearing portion 153t. The fixed member 72 is located away from the rotating member 71 and is fixed to the side surface of the arm base 121a. The screw member 73 is screwed into the fixed member 72, contacts the rotating member 71, and rotates to rotate the rotating member 71 around the pivot point R2, thereby adjusting the distance between the axes ΔL21. Viewed in the direction in which the first rotation axis 153s extends, the pivot point R2, the fixed member 72, and the screw member 73 are located on opposite sides of each other, with the straight line L95 passing through the first rotation axis 153s and the second rotation axis 154s as the boundary.

[0143] This allows the fixed member 72 to receive the reaction force from the first annular member 154c to the rotating member 71 via the screw member 73 when the interaxial distance ΔL21 is increased. Furthermore, the distance from the fulcrum R2 to the contact point (point of force application) between the screw member 73 and the rotating member 71 can be made longer than the distance from the fulcrum R2 to the center R1 (point of application) of the bearing portion 153t. As a result, the force required when increasing the interaxial distance ΔL21 can be reduced. In addition, since the fulcrum R2, fixed member 72 and screw member 73 are aligned in a direction intersecting the straight line L95, the arm base 121a can be made smaller in the direction in which the first rotation transmission member 154a and the second rotation transmission member 154b are aligned.

[0144] Furthermore, a mark 91 is provided on the side surface of the arm base 121a to indicate the position of the rotating member 71 to which a predetermined tension is applied to the first annular member 154c.

[0145] Therefore, the user only needs to adjust the position of the rotating member 71 while looking at the mark 91, and does not need to adjust the position of the rotating member 71 while checking the tension of the first annular member 154c housed in the arm base 121a. As a result, the tension of the first annular member 154c can be easily set to a predetermined tension by the first adjustment unit 157.

[0146] Furthermore, the second rotational transmission member 154b is located on the output side of the transmission path than the first rotational transmission member 154a, and the diameter of the second rotational transmission member 154b is larger than the diameter of the first rotational transmission member 154a.

[0147] Therefore, by increasing the torque using the power transmission unit 152 and adjusting the tension of the first annular member 154c to an appropriate tension using the first adjustment unit 157, the torque increased by the power transmission unit 152 can be transmitted more reliably.

[0148] The power transmission unit 152 further includes a third rotational transmission member 155a provided on the second rotational shaft 154s, a fourth rotational transmission member 155b, and a second annular member 155c wrapped around the third rotational transmission member 155a and the fourth rotational transmission member 155b. The robot 10 further includes a second adjustment unit 158 ​​that adjusts the tension of the second annular member 155c by adjusting the axial distance ΔL31 between the second rotational shaft 154s and the third rotational shaft 126a of the fourth rotational transmission member 155b. The third rotational transmission member 155a, the fourth rotational transmission member 155b, and the second annular member 155c are housed in the arm base 121a. The second adjustment unit 158 ​​is located on the outside of the arm base 121a.

[0149] Therefore, the tension of the second annular member 155c can also be easily adjusted. Furthermore, even when the power transmission section 152 is multi-stage, the configuration allows for adjustment of the inter-axis distances ΔL21 and ΔL31, thus preventing the arm base 121a from becoming larger.

[0150] <Second Embodiment> Figure 10 is a left side view showing the adjustment units 257 and 258 of this embodiment.

[0151] The first stage adjustment section 257 of this embodiment differs from the adjustment section 157 of the first embodiment in the configuration of the screw member 273, and the second stage adjustment section 258 of this embodiment differs from the adjustment section 158 of the first embodiment in the configuration of the screw member 283. The following mainly describes the differences from the above embodiment, and components similar to those in the above embodiment are denoted by the same reference numerals, and their descriptions are omitted as appropriate.

[0152] The first-stage screw member 273 further includes a cylindrical member 273e and a spring 273f, in addition to the male screw portion 73a, screw head 73b, and washer 73c.

[0153] The cylindrical member 273e has a male threaded portion 73a located inside, situated between the threaded head 73b and the washer 73c. ​​The axial length of the cylindrical member 273e is set to such a length that, when the spring 273f (described later) is compressed and the length of the spring 273f matches the length of the cylindrical member 273e, appropriate tension is applied to the second annular member 154c.

[0154] The spring 273f has a cylindrical member 273e and a male threaded portion 73a arranged inside, and is located between the threaded head 73b and the washer 73c. ​​The natural length of the spring 273f is longer than the axial length of the cylindrical member 273e.

[0155] As the male threaded portion 73a is tightened against the fixed upright portion 77 to increase the distance between the axes ΔL21, a reaction force from the second annular member 154c acts on the rotating member 71, compressing the spring 273f. The spring 273f, compressed to a length shorter than its natural length, pushes against the washer 73c. ​​The washer 73c pushes against the rotating upright portion 75. As a result, the rotating member 71 rotates in a direction that approaches the fixed member 72 around the pivot point R2 (counterclockwise in Figure 10).

[0156] Furthermore, the male threaded portion 73a is tightened against the fixed upright portion 77 until the length of the spring 273f is equal to the length of the cylindrical member 273e. This applies a predetermined tension to the second annular member 154c.

[0157] The second-stage screw member 283 has a male threaded portion 83a and a screw head 83b, and has a washer 283c instead of a nut 83c. The screw member 283 also further has a nut 283d, a cylindrical member 283e, and a spring 283f.

[0158] The washer 283c is inserted through the male threaded portion 83a. The washer 283c is positioned between the fixed upright portion 87 and the rotating upright portion 85, and is in contact with the upper surface of the rotating upright portion 85.

[0159] The nut 283d is positioned between the fixed upright portion 87 and the washer 283c while screwed onto the male threaded portion 83a.

[0160] The cylindrical member 283e has a male threaded portion 83a inside and is located between the nut 283d and the washer 283c. The axial length of the cylindrical member 283e is set to a length such that when the spring 283f (described later) is compressed and the length of the spring 283f matches the length of the cylindrical member 283e, appropriate tension is applied to the third annular member 155c.

[0161] The spring 283f has a cylindrical member 283e and a male threaded portion 83a arranged inside, and is located between the nut 283d and the washer 283c. The natural length of the spring 283f is longer than the axial length of the cylindrical member 283e.

[0162] As the male threaded portion 83a is tightened against the fixed upright portion 87 to increase the distance between the axes ΔL31, a reaction force from the third annular member 155c acts on the rotating member 81, compressing the spring 283f. The spring 283f, compressed to a length shorter than its natural length, pushes against the washer 283c. The washer 283c pushes against the rotating upright portion 85. As a result, the rotating member 81 rotates around the pivot point R4 in a direction away from the fixed member 82 (clockwise in Figure 10).

[0163] Furthermore, the male threaded portion 83a is tightened against the fixed upright portion 87 until the length of the spring 283f is the same as the length of the cylindrical member 283e. This applies a predetermined tension to the third annular member 155c. In this way, the springs 273f and 283f may be used to push the rotating members 71 and 81, thereby increasing the distances between the axes ΔL21 and ΔL31. Alternatively, the cylindrical members 273e and 283e may be used to identify the springs 273f and 283f that apply a predetermined tension to the annular members 154c and 155c.

[0164] As described above, the robot 10 having the adjustment parts 257 and 258 of this embodiment also achieves the same effects as the robot 10 of the first embodiment. Furthermore, unlike the adjustment parts 157 and 158 in the robot 10 of the first embodiment, the adjustment parts 257 and 258 of this embodiment have springs 273f and 283f. Therefore, the tension applied to the annular members 154c and 155c can be changed gradually when the screw members 73 and 83 are rotated. As a result, it is possible to suppress the breakage of the annular members 154c and 155c when the screw members 73 and 83 are rotated too much.

[0165] Furthermore, in the robot 10 shown in Figure 10, although not shown, the adjustment units 167 and 168 of the third drive unit 160 can also be configured in the same way as the adjustment units 257 and 258, and the effects are as described above.

[0166] The configuration of the robot system 1 is not limited to the above. For example, the robot 10 is not limited to a parallel link type robot, but may be other robots such as a horizontal articulated robot (SCARA robot), a 6-axis vertical articulated robot, a dual-arm robot, or a self-propelled robot.

[0167] Furthermore, in cases where the two power transmission units are not arranged side by side, such as the second power transmission unit 152 and the third power transmission unit 162, the rotating shaft of the rotary transmission member may be supported from both ends, and adjustment units may be provided at both ends of the rotating shaft.

[0168] Although the robot system and robot of the present invention have been described above in the illustrated embodiments, the present invention is not limited to these embodiments. Furthermore, each part of the robot system and robot can be replaced with any structure capable of performing similar functions. In addition, any structure may be added to the robot system and robot. [Explanation of symbols]

[0169] 1...Robot system, 10...Robot, 20...Control device, 61...Bearing, 62...Bearing, 63...Bearing holder, 63a...First cylindrical part, 63b...Second cylindrical part, 63c...Third cylindrical part, 64a...Through hole, 64b...Through hole, 65a...Through hole, 65b...Through hole, 67...Cylindrical member, 71...Rotating member, 72...Fixed member, 73...Screw member, 73a...Male threaded part, 73b...Screw head, 73c...Washer, 74...Rotating body part, 74a...Pivot member, 74b...Holder insertion hole, 74c...Screw, 74h1...Through hole, 74h2...Through hole, 74h3...Through hole, 74h4...Through hole, 74h 5…Through hole, 74h6…Through hole, 75…Rotating upright part, 75h…Through hole, 76…Fixed main body part, 77…Fixed upright part, 77h…Screw hole, 81…Rotating member, 82…Fixed member, 83…Screw member, 83a…Male threaded part, 83b…Screw head, 83c…Nut, 84…Rotating main body part, 85…Rotating upright part, 85h…Through hole, 86…Fixed main body part, 87…Fixed upright part, 87h…Screw hole, 91…Mark, 92…Scale, 93…Mark, 94…Scale, 110…Base, 121…First arm, 121a…Arm base, 121b…Bottom plate part, 121c…Side plate part, 121d…Side plate part, 121e…Link support part Material, 121f...Main body, 121g...Protruding part, 122...Second arm, 123...Third arm, 124...Fourth arm, 125...First joint, 126...Second joint, 126a...Shaft (Third rotation axis), 126b...Bearing part, 126c...Bearing part, 127...Third joint, 128...Fourth joint, 131...Link mechanism, 131a...Link, 131b...Link, 131c...Pivot, 131d...Pivot, 131h...Through hole, 132...Link mechanism, 132a...Link, 132b...Link, 132c...Link, 132...Pivot, 132e...Pivot, 132f...Pivot, 132 g...pivot, 140...first drive unit, 150...second drive unit, 151...second motor, 151a...second output shaft, 151b...second housing, 151c...mount, 152...second power transmission section, 153a...input side rotation transmission member, 153b...output side rotation transmission member, 153c...annular member, 153s...rotating shaft (first rotating shaft), 153t...bearing section, 154a...input side rotation transmission member (first rotation transmission member), 154b...output side rotation transmission member (second rotation transmission member), 154c...annular member (first annular member), 154s...rotating shaft (second rotating shaft), 154t...bearing section,155a...Input side rotation transmission member (3rd rotation transmission member), 155b...Output side rotation transmission member (4th rotation transmission member), 155c...Annular member (2nd annular member), 157...Adjustment section (1st adjustment section), 158...Adjustment section (2nd adjustment section), 160...3rd drive unit, 161...3rd motor, 161a...3rd output shaft, 161b...3rd housing, 161c...Mount, 162...3rd power transmission 163a... Input side rotation transmission member, 163b... Output side rotation transmission member, 163c... Annular member, 163s... Rotating shaft, 163t... Bearing part, 164a... Input side rotation transmission member, 164b... Output side rotation transmission member, 164c... Annular member, 164s... Rotating shaft, 164t... Bearing part, 165a... Input side rotation transmission member, 165b... Output side rotation transmission member, 165c... Annular member, 166... Bearing section, 166a...Bearing, 167...Adjustment section, 168...Adjustment section, 170...Fourth drive unit, 200...Robot arm, 257...Adjustment section, 258...Adjustment section, 273...Screw member, 273e...Cylindrical member, 273f...Spring, 283...Screw member, 283c...Washer, 283d...Nut, 283e...Cylindrical member, 283f...Spring, A1...First axis, A2...Second axis, A3...Third axis , A4...4th axis, A5...5th axis, D1...1st direction, D2...2nd direction, D3...3rd direction, E1...end effector, R1...center, R2...fulcrum, R3...center, R4...fulcrum, L1...straight line, L 2...straight line, L3...straight line, L4...straight line, L5...straight line, L6...straight line, L74...straight line, L95...straight line, ΔL21...distance between axes, ΔL22...distance between axes, ΔL31...distance between axes, ΔL32...distance between axes,

Claims

1. Multiple arms that are rotatably connected, A motor that rotates the aforementioned arm, A power transmission unit comprising a first rotation transmission member, a second rotation transmission member, and a first annular member wrapped around the first and second rotation transmission members, arranged in the power transmission path from the motor to the arm, and transmitting the rotational driving force of the motor, A first adjustment unit adjusts the tension of the first annular member by adjusting the distance between the first rotation axis of the first rotation transmission member and the second rotation axis of the second rotation transmission member, Equipped with, The arm has an arm base that houses the motor, the first rotation transmission member, the second rotation transmission member, and the first annular member. The robot is characterized in that the first adjustment unit is located on the outside of the arm base.

2. The power transmission unit further includes a bearing that rotatably supports one end of the first rotating shaft, The robot according to claim 1, wherein the first adjustment unit is installed on the side of the arm base so as to be able to adjust the position of the bearing portion relative to the arm base.

3. The robot according to claim 2, wherein at least a portion of the bearing portion is located outside the arm base.

4. The first adjustment unit is, A rotating member is provided on the side of the arm base, which holds the bearing portion and is rotatable around a pivot point spaced apart from the center of the bearing portion. A fixing member is located away from the rotating member and is fixed to the side surface of the arm base, A screw member that is screwed into the fixed member, contacts the rotating member, and rotates to rotate the rotating member around the pivot point, thereby adjusting the distance between the axes, It has, The robot according to claim 2 or 3, wherein, viewed in the direction in which the first rotation axis extends, the pivot point, the fixing member, and the screw member are located on opposite sides of each other with a straight line passing through the first rotation axis and the second rotation axis as the boundary.

5. The robot according to claim 4, wherein a mark is provided on the side surface of the arm base indicating the position of the rotating member at which a predetermined tension is applied to the first annular member.

6. The second rotational transmission member is located on the output side of the transmission path than the first rotational transmission member. The robot according to any one of claims 1 to 3, wherein the diameter of the second rotational transmission member is larger than the diameter of the first rotational transmission member.

7. The power transmission unit further comprises a third rotational transmission member provided on the second rotational shaft, a fourth rotational transmission member, and a second annular member wrapped around the third rotational transmission member and the fourth rotational transmission member. The system further includes a second adjustment unit that adjusts the tension of the second annular member by adjusting the distance between the second rotation shaft and the third rotation shaft of the fourth rotation transmission member, The third rotation transmission member, the fourth rotation transmission member, and the second annular member are housed in the arm base. The robot according to any one of claims 1 to 3, wherein the second adjustment unit is located outside the arm base.

Images