Robotic Arms and Robotic Systems

Abstract

To provide: a robot arm capable of suppressing swing of wires laid therein; and a robot system comprising the robot arm.SOLUTION: A robot arm includes: a first member; and a second member translating along an axis located in the first member or rotating around the axis. The first member includes: a base; a drive unit generating drive force; a joint portion having a driven pulley and transmitting the drive force to the second member; a belt transmitting the drive force generated by the drive unit to the driven pulley; a sensor provided in a position overlapping with a region surrounded by the driven pulley and the belt in a plan view along the axis and detecting vibration; a wire routed to the region and coupled to the sensor; and a supporting member provided in the region and supporting the wire.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a robot arm and a robot system. [Background technology]

[0002] Due to rising labor costs and labor shortages, various robots are being introduced into manufacturing sites. Robots are equipped with robotic arms that can perform various movements, automating tasks that have previously been performed by humans.

[0003] For example, Patent Document 1 discloses a SCARA robot including a main body and a horizontally articulated arm connected to the main body. The horizontally articulated arm is composed of a first arm and a second arm. The base end of the first arm is rotatably connected to the main body via a vertically extending rotation shaft. The base end of the second arm is rotatably connected to the tip of the first arm via another vertically extending rotation shaft. The tip of the second arm is provided with an actuating shaft formed by a spline shaft of a ball spline, a mechanism for axially moving the actuating shaft and rotating it around the axis, a Z-axis motor for axially driving the actuating shaft, and an R-axis motor for rotating the actuating shaft around the axis. Driving force is transmitted between the Z-axis motor and the movement mechanism via pulleys, timing belts, etc. Similarly, driving force is transmitted between the R-axis motor and the rotation mechanism via pulleys, timing belts, etc. By transmitting such a driving force, the operating shaft can be moved or rotated, and the chuck member attached to the operating shaft is operated.

[0004] In recent years, there has been a demand for more advanced robots, and this has led to an increasing demand for attaching various functional components to robot arms. Functional components need to be connected to the robot's main body via power lines and communication lines. These wires are laid inside the robot arm to prevent breakage due to contact between the robot arm and an object. Examples of functional components include sensors that detect the movement of the robot arm. Functional components such as sensors often achieve high performance when attached to the tip of the robot arm. For this reason, wires are laid across the robot arm from its base end to its tip. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 7-116974 Summary of the Invention [Problem to be solved by the invention]

[0006] However, driving force transmission components such as timing belts are arranged inside the robot arm. If the wiring of the sensor or other components comes into contact with the driving force transmission components, it can cause disconnection or poor connection. In particular, if the wiring is not fixed, it will swing as the robot arm moves, making it more likely to come into contact with the timing belt or other components. For this reason, there is a need to realize a robot arm that can prevent the swinging of wiring such as sensors, for example, by fixing the wiring inside the robot arm. [Means for solving the problem]

[0007] A robot arm according to an application example of the present invention includes: a first arm that rotates around a first axis; a second arm that rotates around a second axis located on the first arm and parallel to the first axis; and, The aforementioned Second Arm Located in a third axis parallel to the second axis; Translation along an axis or Third shaft of Around Rotation do shaft and, Equipped with The aforementioned Second Arm teeth, With the base, No. 1 Generates driving force No. 1 A drive unit; a second drive unit that generates a second drive force; a first drive pulley connected to the first drive unit; a first driven pulley provided on the shaft; A first pulley is stretched between the first driving pulley and the first driven pulley. Belt and a second drive pulley connected to the second drive unit; a second driven pulley provided on the shaft; an intermediate member having a plurality of intermediate pulleys, the intermediate member being disposed between the second driving portion and the second driven pulley when viewed in a plane along the third axis; an intermediate belt stretched between the second drive pulley and the intermediate member; a second belt wound around the intermediate member and the second driven pulley; The aforementioned Third When viewed in a plane along the axis, No. 1 driven pulley and No. 1 surrounded by a belt a belt region that is a combination of the first region and a second region that is surrounded by the second driven pulley and the second belt; It is located in a position overlapping with At least one of angular velocity and acceleration a sensor for detecting the A columnar support member at least a portion of which is disposed in the belt region when viewed in a plan view along the third axis; When viewed in a plane along the third axis, the belt region is supported by the support member. , a wiring connected to the sensor; The present invention is characterized by having the following.

[0008] A robot arm according to an application example of the present invention includes: a first arm that rotates around a first axis; a second arm that is located on the first arm and rotates around a second axis that is parallel to the first axis; a shaft located on the second arm that translates along or rotates around a third axis parallel to the second axis; Equipped with The second arm is With the base, a first drive unit that generates a first drive force; a second drive unit that generates a second drive force; a first drive pulley connected to the first drive unit; a first driven pulley provided on the shaft; a first belt wound around the first driving pulley and the first driven pulley; a second drive pulley connected to the second drive unit; a second driven pulley provided on the shaft; an intermediate member having a plurality of intermediate pulleys, the intermediate member being disposed between the second driving portion and the second driven pulley when viewed in a plane along the third axis; an intermediate belt stretched between the second drive pulley and the intermediate member; a second belt wound around the intermediate member and the second driven pulley; a columnar support member having one end disposed in an overlapping region included in both a first region surrounded by the first driven pulley and the first belt and a second region surrounded by the second driven pulley and the second belt when viewed in a plane along the third axis; wiring that is supported by the support member in the overlapping region when viewed in a plan view along the third axis; With death, The support member is separate from the base. It is characterized by:

[0009] A robot system according to an application example of the present invention includes: A robot arm according to an application example of the present invention; a control device for controlling the operation of the robot arm; The present invention is characterized by comprising: [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a side view showing a robot system according to an embodiment. [Figure 2] FIG. 2 is a partial cross-sectional view of the second arm shown in FIG. [Figure 3] 2 is a perspective view of the internal structure of the second arm shown in FIG. 1 as viewed from the plus side to the minus side of the z axis. [Figure 4]4 is a partial cross-sectional perspective view of the cross section of the second arm shown in FIG. 3 cut along the xy plane, as viewed from the negative side toward the positive side of the z axis. FIG. [Figure 5] FIG. 2 is a diagram showing an area surrounded by a driven pulley and a belt connected to a shaft. [Figure 6] 2, showing the routing path of the wiring in the internal space. FIG. [Figure 7] FIG. 7 is a partially enlarged perspective view of the vicinity of the support member shown in FIG. 6. [Figure 8] FIG. 10 is a partially enlarged perspective view showing a robot arm according to a first modified example. [Figure 9] FIG. 10 is a partially enlarged perspective view showing a support member of a robot arm according to a second modified example. [Figure 10] FIG. 11 is a partially enlarged cross-sectional view showing a robot arm according to a third modified example. DETAILED DESCRIPTION OF THE INVENTION

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a robot arm and a robot system according to the present invention will now be described in detail with reference to the accompanying drawings.

[0012] 1.Robot System First, a robot system according to an embodiment will be described.

[0013] FIG. 1 is a side view showing a robot system 1 according to an embodiment. For ease of explanation, in each drawing of the present application, three mutually orthogonal axes are set as an x-axis, a y-axis, and a z-axis, each of which is indicated by an arrow. In the following explanation, the direction parallel to the x-axis is referred to as the "x-axis direction," the direction parallel to the y-axis is referred to as the "y-axis direction," and the direction parallel to the z-axis is referred to as the "z-axis direction." In addition, in the following explanation, the tip end side of each illustrated arrow is referred to as "+ (plus)" and the base end side is referred to as "- (minus)." Furthermore, in the following explanation, for ease of explanation, the +z-axis direction is referred to as "up" and the -z-axis direction is referred to as "down."

[0014] 1 includes a robot 2 and a control device 3 that controls the operation of the robot 2. The uses of the robot system 1 are not particularly limited, but examples thereof include workpiece holding, transport, assembly, and inspection.

[0015] 1.1.Robots In this embodiment, the robot 2 is a horizontal articulated robot (SCARA robot). The robot 2 includes a base 21 and a robot arm 20. In this embodiment, the robot arm 20 includes a first arm 22, a second arm 23, a shaft 24, a payload 244, and an end effector 29, which will be described later.

[0016] 1.1.1. Foundation The base 21 is fixed to an installation surface (not shown) with bolts or the like. Examples of the installation surface include a floor, a wall, a ceiling, and the top surface of a table or a stand. The outer shape of the base 21 shown in FIG. 1 is a substantially rectangular parallelepiped. Note that the outer shape of the base 21 is not limited to the shape shown in FIG. 1 and may be any shape.

[0017] The base 21 has a drive unit 261. The drive unit 261 generates a drive force that rotates the first arm 22 about the first axis AX1 relative to the base 21. The drive unit 261 also has an encoder (not shown) that detects the amount of rotation. The rotation angle of the first arm 22 relative to the base 21 can be detected from the output from this encoder.

[0018] 1.1.2.Robot Arm The robot arm 20 is connected to a base 21, and its posture is controlled by a control device 3. This allows the end effector 29 to be held at a desired position and posture to perform various tasks. In the robot arm 20 shown in FIG. 1, a first arm 22, a second arm 23 (first member), a shaft 24 (second member), a payload 244, and an end effector 29 are connected in this order. In the following description, for convenience of explanation, the end effector 29 side of the robot 2 will be referred to as the "tip" and the base 21 side will be referred to as the "base end."

[0019] The first arm 22 is rotatable about a first axis AX1 parallel to the z-axis relative to the base 21. The second arm 23 is provided at the tip of the first arm 22 and is rotatable about a second axis AX2 parallel to the first axis AX1. The shaft 24 is provided at the tip of the second arm 23 and is rotatable about a third axis AX3 parallel to the second axis AX2 and is translatable along the third axis AX3.

[0020] The second arm 23 (first member) has a base 231 (main body), an upper cover 232, a lower cover 233, drive units 262, 263, and 264, a joint unit 240, and an inertial sensor 4.

[0021] The base 231 is the skeleton of the second arm 23 and supports the drive units 262, 263, 264, etc. The upper cover 232 is provided above the base 231 and covers the drive units 262, 263, 264, etc. The lower cover 233 is provided below the base 231 and covers the inertial sensor 4, etc., placed on the lower surface of the base 231.

[0022] The driving unit 262 is located at the base end of the base 231, and generates a driving force that rotates the second arm 23 about the second axis AX2 relative to the first arm 22. The driving unit 262 includes a motor, a reducer, an encoder, etc., which are not shown. The rotation angle of the second arm 23 relative to the first arm 22 can be detected based on the output from the encoder.

[0023] The driving unit 263 is located between the base end and the tip end of the base 231, and generates a driving force that rotates the ball screw nut 241 and translates the shaft 24 in a direction along the third axis AX3. The driving unit 263 includes a motor, a reducer, an encoder, and the like, all of which are not shown. The amount of translation of the shaft 24 relative to the second arm 23 can be detected by the output from the encoder.

[0024] The driving unit 264 is located between the base end and the tip end of the base 231, and generates a driving force that rotates the spline nut 242 and rotates the shaft 24 about the third axis AX3. The driving unit 264 includes a motor, a reducer, an encoder, etc., which are not shown. The amount of rotation of the shaft 24 relative to the second arm 23 can be detected by the output from the encoder.

[0025] The joint unit 240 transmits a driving force to the shaft 24. Specifically, the joint unit 240 converts the driving force from the driving units 263 and 264 into the translational and rotational movements of the shaft 24.

[0026] The shaft 24 is a cylindrical shaft body and is capable of translating relative to the second arm 23 along a third axis AX3 that is aligned in the vertical direction, and is also rotatable about the third axis AX3.

[0027] A ball screw nut 241 and a spline nut 242 are provided midway along the length of the shaft 24, and the shaft 24 is supported by these.

[0028] A payload 244 for mounting an end effector 29 is provided at the tip of the shaft 24. The end effector 29 mounted on the payload 244 is not particularly limited, and examples thereof include a hand for holding an object, a tool for processing an object, and an inspection device for inspecting an object. Note that the robot arm 20 may also be configured without the end effector 29.

[0029] Next, each part of the second arm 23 will be described in detail. FIG. 2 is a partial cross-sectional view of the second arm 23 shown in FIG. 1. FIG. 3 is a perspective view of the internal structure of the second arm 23 shown in FIG. 1, viewed from the positive side toward the negative side of the z-axis. FIG. 4 is a partial cross-sectional perspective view of the cross section of the second arm 23 shown in FIG. 3 cut along the xy plane, viewed from the negative side toward the positive side of the z-axis. FIG. 5 is a diagram showing an area 200 surrounded by driven pulleys 276, 296 connected to the shaft 24 and belts 274, 294. Note that the upper cover 232 is omitted in FIGS. 3 and 4. Also, at least some of the members not described below are omitted in FIGS. 2 to 4.

[0030] 5, the second arm 23 has belts 274, 284, and 294, driving pulleys 275 and 285, and driven pulleys 276, 286, and 296. The joint unit 240 described above has the driven pulley 276 connected to the ball screw nut 241, and the driven pulley 296 connected to the spline nut 242.

[0031] The driving pulley 275 shown in Fig. 5 is connected to the driving unit 263 shown in Fig. 3. The driven pulley 276 shown in Fig. 5 is connected to the ball screw nut 241 shown in Fig. 2. The belt 274 shown in Fig. 5 is an endless belt that is stretched between the driving pulley 275 and the driven pulley 276. The driving force generated by the driving unit 263 is transmitted to the ball screw nut 241 via the driving pulley 275, the belt 274, and the driven pulley 276. This allows the shaft 24 shown in Fig. 2 to translate in the direction along the third axis AX3, that is, in the z-axis direction.

[0032] The drive pulley 285 shown in FIG. 5 is connected to the drive unit 264 shown in FIG. 3. The driven pulley 286 shown in FIG. 5 is a speed reduction pulley that transmits the drive force from the belt 284 to the belt 294 while reducing the rotational speed. The driven pulley 296 shown in FIG. 5 is connected to the spline nut 242 shown in FIG. 2. The belt 284 shown in FIG. 5 is an endless belt that is stretched between the drive pulley 285 and the driven pulley 286. The belt 294 is an endless belt that is stretched between the driven pulley 286 and the driven pulley 296. The drive force generated by the drive unit 264 is transmitted to the spline nut 242 via the drive pulley 285, the belt 284, the driven pulley 286, the belt 294, and the driven pulley 296. This allows the shaft 24 shown in FIG. 2 to rotate around the third axis AX3.

[0033] 2 has a hollow structure, and includes an internal space 235, a top plate 236 (first base) provided above the internal space 235, and a bottom plate 237 (second base) provided below the internal space 235.

[0034] The top plate 236 has a through hole 238 (first through hole) that penetrates in a direction parallel to the third axis AX3. This through hole 238 connects the upper part of the top plate 236, that is, the inside of the upper cover 232, with the internal space 235.

[0035] The bottom plate 237 has a through hole 239 (second through hole) that penetrates in a direction parallel to the third axis AX3. This through hole 239 connects the lower part of the bottom plate 237, i.e., the inside of the lower cover 233, with the internal space 235.

[0036] The through holes 238 and 239 may function as ventilation holes for eliminating the pressure difference between the upper cover 232, the internal space 235, and the lower cover 233.

[0037] The configurations of the base 231, the upper cover 232, and the lower cover 233 are not limited to those described above. For example, at least two of these may be integrated into one body.

[0038] The drive units 262, 263, and 264 are fixed to the upper surface of the top plate 236. Output shafts (not shown) of the drive units 262, 263, and 264 extend into the internal space 235.

[0039] As shown in FIGS. 2 and 5, the interior space 235 accommodates belts 274, 284, 294, drive pulleys 275, 285, and driven pulleys 276, 286, 296.

[0040] In this embodiment, as shown in FIG. 5, the driver 262 is disposed at a position overlapping the second axis AX2 of the base 231. In this embodiment, the driver units 263 and 264 are disposed between the second axis AX2 and the third axis AX3 of the base 231. As shown in FIG. 5, the driver units 263 and 264 are aligned in the x-axis direction on either side of a line L connecting the second axis AX2 and the third axis AX3. By aligning the driver units 263 and 264 in the x-axis direction on either side of the line L, the weight of the second arm 23 can be more evenly distributed. This can suppress abnormal vibrations and other problems that may occur due to the rotation of the second arm 23. The driven pulley 286 is disposed between the driver unit 264 and the driven pulley 296. The arrangement of the driver units 262, 263, and 264 on the base 231 is not limited to the above arrangement.

[0041] The inertial sensor 4 may be an angular velocity sensor that detects angular velocity, an acceleration sensor that detects acceleration, or a composite sensor that detects both. The number of axes along which the angular velocity sensor detects angular velocity is not particularly limited, and may be one, two, or three axes. Similarly, the number of axes along which the acceleration sensor detects acceleration is not particularly limited, and may be one, two, or three axes.

[0042] As shown in Fig. 2, the inertial sensor 4 is provided on the underside of the bottom plate 237. The inertial sensor 4 is provided on the underside of the bottom plate 237 near the third axis AX3. This increases the sensitivity of the inertial sensor 4 to detecting angular velocity and acceleration when the second arm 23 rotates. Specifically, as shown in Fig. 5, the inertial sensor 4 is provided at a position overlapping with the "area 200" defined by the driven pulleys 276, 296 and the belts 274, 294.

[0043] The belts 274 and 294 are respectively wound around driven pulleys 276 and 296 connected to the shaft 24. Therefore, as shown in FIG. 5, when viewed in a plane along the third axis AX3, an area is formed surrounded by the belts 274 and 294 extending from the driven pulleys 276 and 296 in the -y-axis direction. This area is referred to as "area 200." When viewed in a plane along the third axis AX3, the inertial sensor 4 is disposed at a position overlapping with the area 200 on the underside of the bottom plate 237. This arrangement improves the detection sensitivity of the inertial sensor 4. Note that the position overlapping with the area 200 refers to a position where at least a portion of the inertial sensor 4 overlaps with the area 200 when viewed in a plane. In FIG. 5, the area 200 is indicated by a dot.

[0044] Wiring 209 is connected to the inertial sensor 4. Examples of the wiring 209 include a power line that supplies power to drive the inertial sensor 4, a signal line that transmits a control signal that controls the operation of the inertial sensor 4, and a signal line that outputs a detection signal of angular velocity or acceleration detected by the inertial sensor 4. The signal line may be an electrical wiring or an optical wiring such as an optical fiber or an optical waveguide. Therefore, in this specification, "the wiring 209 is connected" refers to an electrical or optical connection. The wiring 209 is routed from inside the base 21 to the inertial sensor 4. Specifically, although not shown, the wiring 209 passes through the inside of the base 21 and the inside of the first arm 22 in this order, and is routed to the inside of an upper cover 232 of the second arm 23, which is provided above the top plate 236. The wiring 209 passes through a through-hole 238 in the top plate 236 , and through-holes 239 in the area 200 and bottom plate 237 in this order, and is routed to the inertial sensor 4 .

[0045] 5, the wiring 209 is routed so as to pass through the region 200 in the internal space 235, and therefore the wiring 209 can be routed over a shorter path length relative to the inertial sensor 4 provided on the underside of the bottom plate 237 shown in Fig. 2. As a result, the weight of the wiring 209 can be reduced, and the influence of disturbances on the signal transmitted by the wiring 209 can be reduced.

[0046] In contrast, conventionally, when wiring is fixed to the inner wall surface of a robot arm, there is a problem that the wiring path length tends to become long. As the wiring path length increases, the weight of the robot arm increases, so from the perspective of reducing the robot arm's weight, it is also necessary to lay the wiring along as short a path as possible. In particular, functional parts often exhibit particularly high performance when attached to the bottom of the robot arm. Meanwhile, timing belts and other components are concentrated inside the robot arm. For this reason, there has been a problem that it is particularly difficult to ensure a wiring path that reaches the bottom of the robot arm while keeping the wiring path length down.

[0047] However, if the wiring 209 is routed in the area 200, the wiring 209 may come into contact with the belts 274 and 294, possibly damaging the wiring 209. In particular, when the second arm 23 rotates, the wiring 209 is likely to swing due to centrifugal force, increasing the probability that the wiring 209 will come into contact with the belts 274 and 294.

[0048] Therefore, in this embodiment, a support member 210 is provided in the region 200 as shown in FIG. 5. The support member 210 is columnar, extending from the top plate 236 through the inside of the belts 274 and 294 as shown in FIG. 4, and extending to the bottom plate 237 as shown in FIG. 2. The wiring 209 is supported by the support member 210. This allows the wiring 209 to be guided along the support member 210 while suppressing swinging of the wiring 209. As a result, the wiring 209 can be appropriately routed over a short path length, and the probability of contact between the wiring 209 and the belts 274 and 294 can be reduced. Furthermore, as shown in FIG. 2, when viewed in a plan view along the X-axis direction, the support member 210 extends from the through hole 238 in the −Z-axis direction and is bent toward the through hole 239 at a position where it overlaps with the belt 294.

[0049] FIG. 6 is a partially enlarged view of FIG. 2, showing the routing path of the wiring 209 in the internal space 235. In FIG.

[0050] The wiring 209 is routed along and supported by the support member 210. "Support" means that the wiring 209 is fixed to the support member 210 to such an extent that swinging of the wiring 209 can be suppressed. The fixing method is not particularly limited, and a method using an adhesive or a method of wrapping the wiring 209 around the support member 210 may be used, but in this embodiment, a method using a cable tie 220 (anchoring member) is adopted. By using the cable tie 220, the work of fixing the wiring 209 to the support member 210 can be easily and quickly performed. Note that, in addition to the cable tie 220, examples of the anchoring member include a clip, a string, a rubber band, and an adhesive tape.

[0051] Fig. 7 is a partially enlarged perspective view of the vicinity of the support member 210 shown in Fig. 6. Note that the clamp 225, the wiring 209, and the binding band 220 are omitted from Fig. 7. Fig. 7 also shows cross sections of some parts.

[0052] The support member 210 shown in FIG. 7 has a columnar shape with a generally constant width, but has a reduced-width portion 215 where the width is partially narrowed. The width of the support member 210 refers to the length in the short direction perpendicular to the longitudinal direction of the columnar support member 210. The reduced-width portion 215 contributes to preventing misalignment of the cable tie 220 when the cable tie 220 is attached to the support member 210. In other words, when the cable tie 220 is attached to the reduced-width portion 215, the cable tie 220 is less likely to come off the reduced-width portion 215. This makes it possible to prevent problems caused by unintended misalignment of the cable tie 220.

[0053] 7 has an upper end 211 (one end) fixed to the upper side of the top plate 236, passes through the through-hole 238, the inside of the belts 274 and 294, and the through-hole 239, and has a lower end 212 (the other end) fixed to the underside of the bottom plate 237. By fixing both ends to the base 231 in this manner, it is possible to suppress the swinging of the support member 210 itself, and as a result, it is possible to suppress the swinging of the wiring 209. Examples of methods for fixing the support member 210 to the base 231 include screw fastening, fixing by fitting, fixing with an adhesive, fixing with a clip, etc. As shown in FIG. 7, the upper end 211 of the support member 210 is plate-shaped along the top plate 236, and a part of the plate is bent toward the through-hole 238.

[0054] Furthermore, although the support member 210 may be integrated with the base 231, the support member 210 shown in Fig. 7 is separate from the base 231. This makes it possible to adopt an assembly sequence in which the belts 274, 294 are looped over and then the support member 210 is attached to the base 231. As a result, it is possible to prevent the support member 210 from getting in the way when looping over the belts 274, 294.

[0055] Furthermore, examples of the constituent material of the support member 210 include metal materials such as iron-based alloys like stainless steel, aluminum-based alloys, and titanium-based alloys, as well as resin materials and ceramic materials.

[0056] Note that support member 210 only needs to pass through region 200, but is preferably provided to avoid the range in which belts 274, 294 swing. The range in which belts 274, 294 swing refers to the amplitude of the deflection of belts 274, 294 when second arm 23 rotates. By setting region 200 to avoid such a range, wiring 209 is less likely to be damaged even when belts 274, 294 swing.

[0057] As shown in Fig. 6, in addition to the wiring 209, wiring 230 that connects various devices in the robot arm 20 to the base 21 is routed above the top plate 236. These wirings 209, 230 are preferably bundled together to suppress swinging that occurs when the second arm 23 rotates. In this embodiment, as shown in Fig. 6, the wirings 209, 230 are bundled together by a clamp 225 fixed to the support member 210. This suppresses swinging of the wirings 209, 230 and also makes it easier to guide the wiring 209 to the vicinity of the support member 210. As a result, the wiring 209 can be routed to the support member 210 over a shorter path.

[0058] The method for fixing clamp 225 to support member 210 is not particularly limited, and examples thereof include screwing, fitting, and adhesive. Fig. 7 shows screw holes 216 for fixing clamp 225, which are provided in upper end portion 211 of support member 210. Clamp 225 may be fixed to base 231 instead of support member 210.

[0059] As described above, the robot arm 20 according to this embodiment includes the second arm 23 (first member) and the shaft 24 (second member). The shaft 24 translates along or rotates around the third axis AX3 located on the second arm 23.

[0060] The second arm 23 also includes a base 231, drive units 263 and 264 that generate a drive force, a joint unit 240, belts 274 and 294, an inertial sensor 4 that detects vibrations, a wiring 209, and a support member 210 that supports the wiring 209. The joint unit 240 has driven pulleys 276 and 296 and transmits the drive force to the shaft 24. The belts 274 and 294 transmit the drive force generated by the drive units 263 and 264 to the driven pulleys 276 and 296. The inertial sensor 4 is provided at a position that overlaps with a region 200 surrounded by the driven pulleys 276 and 296 and the belts 274 and 294 when viewed in a plan view along the third axis AX3. The wiring 209 is routed through the region 200 and connected to the inertial sensor 4. The support member 210 is provided in the region 200 and supports the wiring 209.

[0061] With this configuration, even when the wiring 209 is subjected to centrifugal force, it is possible to suppress the oscillation of the wiring 209. This reduces the probability that the wiring 209 will come into contact with the belts 274 and 294, and it is possible to suppress damage to the wiring 209.

[0062] Furthermore, even when the inertial sensor 4 is disposed in a position overlapping with the region 200 in the lower part of the second arm 23, the path length of the wiring 209 can be reduced by disposing the support member 210 in the region 200. This allows the weight of the wiring 209 to be reduced, and also makes it possible to further reduce the influence of disturbances on the signal transmitted through the wiring 209.

[0063] In this embodiment, the shaft 24 is capable of translation along the third axis AX3 along the vertical direction and rotation about the third axis AX3, but only one of these movements of the shaft 24 may be performed. In addition, in this embodiment, the joint unit 240 has both the ball screw nut 241 and the spline nut 242, but either one of them may be omitted. If the ball screw nut 241 is omitted, the aforementioned region 200 will be limited to the region surrounded by the belt 294 and the driven pulley 296. On the other hand, if the spline nut 242 is omitted, the aforementioned region 200 will be limited to the region surrounded by the belt 274 and the driven pulley 276.

[0064] On the other hand, region 200 in this embodiment is a combination of the region surrounded by belt 294 and driven pulley 296 and the region surrounded by belt 274 and driven pulley 276. Therefore, as shown in FIG. 5, region 200 includes region 201, which is included in both the region surrounded by belt 294 and driven pulley 296 and the region surrounded by belt 274 and driven pulley 276. Inertial sensor 4 may be provided in a position overlapping region 200, but is preferably provided in a position overlapping region 201. This can particularly enhance the detection sensitivity of inertial sensor 4. In FIG. 5, region 201 is shaded.

[0065] 5, when a straight line L is drawn that passes through both the second axis AX2 and the third axis AX3, the area 201 and the straight line L overlap, and the inertial sensor 4 and the straight line L also overlap. From the viewpoint of the detection sensitivity of the inertial sensor 4, such an arrangement is particularly preferable.

[0066] Furthermore, the shape of the support member 210 may be any shape as long as it can support the wiring 209, but in this embodiment, it has a columnar shape that extends and passes through the inside of the belts 274, 294. The wiring 209 is supported along the support member 210.

[0067] According to this configuration, it is possible to suppress the swinging of the wiring 209 while guiding the wiring 209 along the support member 210. As a result, it is possible to appropriately route the wiring 209 while reducing the probability of the wiring 209 coming into contact with the belts 274 and 294.

[0068] In the robot arm 20 according to this embodiment, the base 231 includes a top plate 236 (first base) and a bottom plate 237 (second base) that face each other via an internal space 235. The internal space 235 is a space through which the belts 274, 294 pass. An upper end 211 (one end) of the support member 210 is fixed to the top plate 236, and a lower end 212 (the other end) is fixed to the bottom plate 237.

[0069] This configuration can suppress the swinging of support member 210 itself. Furthermore, because support member 210 is separate from base 231, an assembly sequence can be adopted in which belts 274, 294 are looped over and then support member 210 is attached to base 231. As a result, support member 210 does not get in the way when belts 274, 294 are looped over.

[0070] Furthermore, in the robot arm 20 according to this embodiment, the top plate 236 (first base) has a through hole 238 (first through hole) penetrating in a direction parallel to the third axis AX3, and the bottom plate 237 (second base) has a through hole 239 (second through hole) penetrating in a direction parallel to the third axis AX3. The wiring 209 is routed along a path that passes through the through hole 238, the internal space 235, and the through hole 239.

[0071] According to this configuration, the wiring 209 can be routed over a shorter path length without detouring around the top plate 236 or the bottom plate 237. This allows the wiring 209 to be lighter in weight and also makes it possible to further suppress the effects of disturbances on the signals transmitted through the wiring 209.

[0072] The robot arm 20 according to this embodiment also has a binding band 220 (anchoring member) that fastens the wiring 209 to the support member 210.

[0073] By using the binding band 220, the wiring 209 can be easily fixed to the support member 210.

[0074] In the robot arm 20 according to this embodiment, the support member 210 has a reduced width portion 215 where the width is partially narrowed. A cable tie 220 (anchoring member) fastens the wiring 209 to the reduced width portion 215.

[0075] According to this configuration, the binding band 220 is less likely to move outward from the width-reduced portion 215. This makes it possible to prevent problems caused by unintended displacement of the binding band 220.

[0076] The robot 2 is not limited to the above-mentioned SCARA robot, but may be other robots such as a vertical articulated robot or a Cartesian coordinate robot. The number of arms provided in the vertical articulated robot is also not particularly limited.

[0077] 1.2.Control Device The operation of the robot 2 is controlled by a control device 3. The control device 3 may be disposed outside the base 21 as shown in FIG. 1, or may be built into the base 21. The control device 3 controls the driving of the driving units 261, 262, 263, and 264 in accordance with a pre-stored operation program. In this way, the control device 3 controls the operation of the robot arm 20.

[0078] As described above, the robot system 1 according to this embodiment includes the robot arm 20 and the control device 3 that controls the operation of the robot arm 20.

[0079] According to such a robot system 1, even when the robot arm 20 operates, it is possible to suppress the swinging of the wiring 209 connected to the inertial sensor 4. This makes it possible to prevent damage to the wiring 209. It is also possible to shorten the path length of the wiring 209. As a result, it is possible to realize a robot system 1 that can operate the robot arm 20 at high speed and that is less likely to cause damage to the wiring 209 even in such a case.

[0080] 2. First Modification Next, a robot arm according to a first modified example will be described.

[0081] Fig. 8 is a partially enlarged perspective view showing a robot arm 20A according to the first modified example, in which some parts are shown in cross section.

[0082] The first modification will be described below, focusing on the differences from the previous embodiment, and omitting the description of the similarities. Note that in Fig. 8, the same reference numerals are used to designate the same components as those in the previous embodiment.

[0083] 8, similarly to the above-described embodiment, a base 231 includes a top plate 236 (first base) and a bottom plate 237 (second base) that face each other via an internal space 235. The internal space 235 is a space through which belts 274, 294 pass. An upper end 211 (one end) of a support member 210A is fixed to the top plate 236, and a lower end 212 (the other end) is spaced apart from the bottom plate 237.

[0084] According to this configuration, a gap is created between the lower end 212 of the support member 210A and the bottom plate 237, and the belts 274, 294 can be passed through this gap and draped over the support member 210A. This makes it possible to adopt an assembly sequence in which the support member 210A is fixed to the base 231 in advance, and then the belts 274, 294 are draped over the support member 210A. On the other hand, because the support member 210A is separate from the base 231, the first modified example can also adopt an assembly sequence in which the belts 274, 294 are draped over the support member 210A and then the support member 210A is attached to the base 231, as in the above embodiment.

[0085] If the upper end 211 of the support member 210A is fixed, it is possible to support the wiring 209 while suppressing the swinging of the wiring 209.

[0086] Furthermore, in this first modified example, the upper end 211 of the support member 210A is fixed to the base 231 and the lower end 212 is spaced apart from the base 231, but conversely, the lower end 212 may be fixed to the base 231 and the upper end 211 may be spaced apart from the base 231.

[0087] 3. Second Modification Next, a robot arm according to a second modified example will be described.

[0088] FIG. 9 is a partially enlarged perspective view showing a support member 210B of a robot arm according to a second modified example.

[0089] The second modification will be described below, focusing on the differences from the previous embodiment, and omitting the description of the similarities. Note that in Fig. 9, the same reference numerals are used to designate the same components as those in the previous embodiment.

[0090] The cross-sectional shape of the support member 210B shown in Fig. 9 has a hollow portion 208. The cross-sectional shape is the cross-sectional shape when the support member 210B is cut along a plane perpendicular to the longitudinal direction of the support member 210B. Specifically, as shown in Fig. 9, the cross-sectional shape of the support member 210B is annular surrounding the circular hollow portion 208. At least a portion of the wiring 209 is routed so as to fit within the hollow portion 208.

[0091] According to this configuration, at least a portion of the wiring 209 is contained within the hollow portion 208 and is not exposed to the outside. This particularly reduces the probability that the wiring 209 will come into contact with the belts 274, 294 shown in Fig. 8 or other objects. As a result, the wiring 209 is particularly unlikely to be damaged.

[0092] In addition to the above-mentioned circular ring shape, shapes having hollow portion 208 include a shape with a part of the ring broken (C-shape), a ring whose outer shape is polygonal or a shape with a part of the ring broken, etc. In the case of a C-shape or a shape with a part of the ring broken, wiring 209 can be inserted into hollow portion 208 from the broken part. Therefore, support member 210B having such a cross section is useful in that it makes it easy to route wiring 209.

[0093] 4. Third Modification Next, a robot arm according to a third modified example will be described. FIG. 10 is a partially enlarged cross-sectional view showing a robot arm 20C according to a third modified example.

[0094] The third modification will be described below, focusing on the differences from the previous embodiment, and omitting the description of the similarities. Note that in Fig. 10, the same reference numerals are used to designate the same components as those in the previous embodiment.

[0095] 10, similarly to the above-described embodiment, the wiring 209 is supported by a support member 210. On the other hand, in the robot arm 20C, the wiring 209 is electrically connected to the end effector 29.

[0096] The end effector 29 is attached to the tip of the shaft 24. Therefore, by supporting the wiring 209 with the support member 210, the path length of the wiring 209 can be kept short, as in the above embodiment, and the influence of disturbances on the signals transmitted through the wiring 209 can be suppressed. Furthermore, by supporting the wiring 209 with the support member 210, it is possible to suppress the oscillation of the wiring 209 and prevent damage to the wiring 209.

[0097] The wiring 209 may be a bundle of multiple wires. In this case, the wiring 209 can be connected to both the inertial sensor 4 and the end effector 29. The wiring 209 may also be connected to a functional unit other than the end effector 29. Examples of the functional unit include various sensors such as an image sensor like a camera, a depth sensor, a distance sensor, and a force sensor, as well as a projector that projects an image.

[0098] As described above, the robot arm 20C according to the third modified example includes the second arm 23 (first member) and the shaft 24 (second member). The shaft 24 translates along or rotates around the third axis AX3 located at the tip of the second arm 23.

[0099] 5 that generate driving force, a joint unit 240, belts 274 and 294, a wire 209, and a support member 210 that supports the wire 209. The joint unit 240 has driven pulleys 276 and 296 and transmits the driving force to the shaft 24. The belts 274 and 294 transmit the driving force generated by the drive units 263 and 264 to the driven pulleys 276 and 296. The wire 209 is routed in an area 200 surrounded by the driven pulleys 276 and 296 and the belts 274 and 294. The support member 210 is provided in the area 200 and supports the wire 209.

[0100] With this configuration, even when the wiring 209 is subjected to centrifugal force, it is possible to suppress the oscillation of the wiring 209. This reduces the probability that the wiring 209 will come into contact with the belts 274 and 294, and it is possible to suppress damage to the wiring 209.

[0101] Furthermore, when a functional unit such as an end effector 29 is attached to the tip of the shaft 24, the wiring 209 can be easily connected to the functional unit. Also in the third modified example, the support member 210 is disposed in the region 200, so the path length of the wiring 209 can be kept short. This allows the weight of the wiring 209 to be reduced, and also makes it possible to further reduce the influence of disturbances on the signal transmitted through the wiring 209.

[0102] The robot arm and robot system of the present invention have been described above based on the illustrated embodiments, but the robot arm and robot system of the present invention are not limited to the above embodiments. For example, the parts of the above embodiments may be replaced with any configuration having the same function, any component may be added to the above embodiments, or a plurality of the above embodiments may be combined. [Explanation of symbols]

[0103] 1...Robot system, 2...Robot, 3...Control device, 4...Inertial sensor, 20...Robot arm, 20A...Robot arm, 20C...Robot arm, 21...Base, 22...First arm, 23...Second arm, 24...Shaft, 29...End effector, 200...Area, 201...Area, 208...Hollow portion, 209...Wiring, 210...Support member, 210A...Support member, 210B...Support member, 211...Upper end portion, 212...Lower end portion, 215...Contracted width portion, 216...Screw hole, 220...Bundle band, 225...Clamp, 230...Wiring, 231...Base, 23 2...Upper cover, 233...Lower cover, 235...Internal space, 236...Top plate, 237...Bottom plate, 238...Through hole, 239...Through hole, 240...Joint portion, 241...Ball screw nut, 242...Spline nut, 244...Payload, 261...Drive unit, 262...Drive unit, 263...Drive unit, 264...Drive unit, 274...Belt, 275...Drive pulley, 276...Driven pulley, 284...Belt, 285...Drive pulley, 286...Driven pulley, 294...Belt, 296...Driven pulley, AX1...First axis, AX2...Second axis, AX3...Third axis, L...Straight line

Claims

1. a first arm that rotates around a first axis; a second arm that rotates around a second axis located on the first arm and parallel to the first axis; a shaft located on the second arm, the shaft translating along or rotating around a third axis parallel to the second axis; Equipped with The second arm is With the base, a first drive unit that generates a first drive force; a second drive unit that generates a second drive force; a first drive pulley connected to the first drive unit; a first driven pulley provided on the shaft; a first belt wound around the first driving pulley and the first driven pulley; a second drive pulley connected to the second drive unit; a second driven pulley provided on the shaft; an intermediate member having a plurality of intermediate pulleys, the intermediate member being disposed between the second driving portion and the second driven pulley when viewed in a plane along the third axis; an intermediate belt stretched between the second drive pulley and the intermediate member; a second belt wound around the intermediate member and the second driven pulley; a sensor that detects at least one of angular velocity and acceleration, the sensor being provided at a position that overlaps a belt area that is a combination of a first area surrounded by the first driven pulley and the first belt and a second area surrounded by the second driven pulley and the second belt when viewed in a plane along the third axis; A columnar support member at least a portion of which is disposed in the belt region when viewed in a plan view along the third axis; a wiring supported by the support member in the belt region and connected to the sensor when viewed in a plan view along the third axis; A robot arm comprising:

2. The robot arm according to claim 1 , wherein the sensor overlaps with an overlapping region that is included in both the first region and the second region when viewed in a plan view along the third axis.

3. The robot arm according to claim 1 , wherein the first drive unit and the second drive unit are aligned in a direction intersecting a straight line passing through the second axis and the third axis when viewed in a plan view along the third axis.

4. the sensor is placed below the first belt and the second belt in the vertical direction, The robot arm according to claim 1 , wherein at least a portion of the wiring is routed along a path that extends from the sensor to a position vertically above the first belt and the second belt.

5. When viewed in a plane along the third axis, a rotation axis of the second drive pulley is disposed at a position away from a straight line passing through the second axis and the third axis, 4. The robot arm according to claim 1, wherein a distance between the straight line and the rotation axis of the intermediate member is shorter than a distance between the straight line and the rotation axis of the second drive pulley.

6. the support member has a columnar shape extending through the inside of the first belt or the second belt, The robot arm according to claim 1 , wherein the wiring is supported along the support member.

7. the base includes a first substrate and a second substrate facing each other across an internal space through which the first belt or the second belt passes; 7. The robot arm according to claim 6, wherein one end of the support member is fixed to the first base and the other end is fixed to the second base.

8. the base includes a first substrate and a second substrate facing each other across an internal space through which the first belt or the second belt passes; 7. The robot arm according to claim 6, wherein one end of the support member is fixed to the first base and the other end is spaced apart from the second base.

9. the first base has a first through-hole penetrating in a direction parallel to the third axis, the second base has a second through-hole penetrating in a direction parallel to the third axis, The robot arm according to claim 7 or 8, wherein the wiring is routed along a path that passes through the first through-hole, the internal space, and the second through-hole.

10. The support member has a cross-sectional shape having a hollow portion, 4. The robot arm according to claim 1, wherein at least a portion of the wiring is accommodated in the hollow portion.

11. 4. The robot arm according to claim 1, further comprising a mooring member for fastening the wiring to the support member.

12. The support member has a narrowed width portion where the width is partially narrowed, The robot arm according to claim 11 , wherein the anchoring member anchors the wiring to the reduced width portion.

13. The robot arm according to claim 12 , wherein the width-reduced portion is located in the belt region when viewed in a plan view along the third axis.

14. 4. The robot arm according to claim 1, wherein the support member is separate from the base.

15. a first arm that rotates around a first axis; a second arm that rotates around a second axis located on the first arm and parallel to the first axis; a shaft located on the second arm, the shaft translating along or rotating around a third axis parallel to the second axis; Equipped with The second arm is With the base, a first drive unit that generates a first drive force; a second drive unit that generates a second drive force; a first drive pulley connected to the first drive unit; a first driven pulley provided on the shaft; a first belt wound around the first driving pulley and the first driven pulley; a second drive pulley connected to the second drive unit; a second driven pulley provided on the shaft; an intermediate member having a plurality of intermediate pulleys, the intermediate member being disposed between the second driving portion and the second driven pulley when viewed in a plane along the third axis; an intermediate belt stretched between the second drive pulley and the intermediate member; a second belt wound around the intermediate member and the second driven pulley; a columnar support member having one end disposed in an overlapping region included in both a first region surrounded by the first driven pulley and the first belt and a second region surrounded by the second driven pulley and the second belt when viewed in a plane along the third axis; wiring that is supported by the support member in the overlapping region when viewed in a plan view along the third axis; and A robot arm characterized in that the support member is separate from the base.

16. A robot arm according to any one of claims 1 to 3; a control device for controlling the operation of the robot arm; A robot system comprising:

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