Robot

Abstract

A robot 100 comprises a base 10 and a first arm 20 movably supported with respect to the base 10. The first arm 20 has a body section 21 comprising an upper wall 22 and a lower wall 23 facing each other, a connection wall 24 connecting the upper wall 22 and the lower wall 23, and a rib 25 connected to the connection wall 24 and at least one of the upper wall 22 and the lower wall 23. The upper wall 22, the lower wall 23, and the rib 25 extend in the thickness direction of the connection wall 24, and an opening 26 opening in the thickness direction of the connection wall 24 is formed in the body section 21.

Description

Robot 【0001】 The present disclosure relates to a robot. 【0002】 Conventionally, a horizontally articulated robot described in Japanese Patent Application Laid-Open No. 2014-4638 (hereinafter referred to as Patent Document 1) is known. This horizontally articulated robot includes a base, a first arm that is horizontally rotatably connected to the base, and a second arm that is horizontally rotatably connected to the first arm. The base and the first arm have a casing having a hollow box-shaped rectangular parallelepiped shape. 【0003】 Japanese Patent Application Laid-Open No. 2014-4638 【0004】 In the above configuration, when attempting to increase the strength of the casing, it is conceivable to form ribs that connect the inner walls of the casing. However, such a casing having a hollow box shape with ribs formed inside may be difficult to mold. 【0005】 The robot of the present disclosure includes a base and an arm that is movably supported with respect to the base, and at least one of the arm and the base has a main body portion including a pair of opposing walls facing each other, a connecting wall that connects the pair of opposing walls, and ribs connected to at least one of the pair of opposing walls and the connecting wall. The pair of opposing walls and the ribs extend in the thickness direction of the connecting wall, and an opening that opens in the thickness direction of the connecting wall is formed in the main body portion. 【0006】 According to the present disclosure, it is possible to provide a robot having a main body portion that easily ensures strength and is easy to mold. 【0007】FIG. 1 is a side view of the robot according to Embodiment 1. FIG. 2 is a plan view of the first arm. FIG. 3 is a side view of the first arm. FIG. 4 is a bottom view of the first arm. FIG. 5 is a sectional view taken along line A - A of FIG. 3. FIG. 6 is a sectional view taken along line B - B of FIG. 3. FIG. 7 is a plan view of the second arm. FIG. 8 is a side view of the second arm. FIG. 9 is a bottom view of the second arm. FIG. 10 is a sectional view taken along line C - C of FIG. 8. FIG. 11 is a sectional view taken along line D - D of FIG. 8. FIG. 12 is a perspective view of the robot according to Embodiment 2. FIG. 13 is a sectional perspective view taken along line E - E of FIG. 12. FIG. 14 is a perspective view showing the periphery of the base in the robot. FIG. 15 is a perspective view of the robot according to Embodiment 3. FIG. 16 is a sectional perspective view taken along line F - F of FIG. 15. FIG. 17 is a perspective view of the first arm according to Embodiment 4. FIG. 18 is a sectional perspective view taken along line G - G of FIG. 17. FIG. 19 is a side view of the robot according to Embodiment 5. FIG. 20 is a perspective view showing the periphery of the base of the robot according to Embodiment 6. FIG. 21 is a perspective view showing the periphery of the base of the robot according to Embodiment 7. FIG. 22 is a perspective view showing the periphery of the first arm of the robot according to Embodiment 8. FIG. 23 is a sectional view taken along line H - H of FIG. 22. FIG. 24 is a perspective view showing the periphery of the first arm of the robot according to Embodiment 9. FIG. 25 is a sectional view taken along line I - I of FIG. 24. FIG. 26 is a perspective view showing the periphery of the first arm of the robot, showing a state in which a communication hole is formed in the plate portion. FIG. 27 is a sectional view taken along line J - J of FIG. 26. FIG. 28 is a perspective view showing the periphery of the second arm in the robot, with the cover and the wiring portion omitted. FIG. 29 is a perspective view showing the periphery of the second arm in the robot, with the first cover wall and the wiring portion omitted. FIG. 30 is a perspective view showing the periphery of the second arm in the robot, with the wiring portion omitted. FIG. 31 is a perspective view showing the periphery of the second arm in the robot. FIG. 32 is a sectional view showing the internal structure of the second arm and the cover. FIG. 33 is a side view showing the periphery of the second arm in the robot, with the peripheral wall of the cover and the wiring portion omitted. FIG. 34 is a perspective view showing the periphery of the second arm of the robot provided with a motor cover. FIG. 35 is a perspective view showing the periphery of the second arm of the robot provided with a motor cover, showing a state in which a through hole is formed in the motor cover.FIG. 36 is a perspective view showing the periphery of the first arm of the robot according to Embodiment 11. FIG. 37 is a perspective view showing the periphery of the first arm of the robot provided with a motor cover. FIG. 38 is a perspective view showing the periphery of the first arm of the robot provided with a motor cover, showing a state in which a through hole is formed in the motor cover. FIG. 39 is a cross-sectional view showing the internal structure around the first joint portion of the first arm. FIG. 40 is a perspective view showing the periphery of the first arm of the robot according to Embodiment 12. FIG. 41 is a perspective view of the robot according to Embodiment 13. FIG. 42 is a rear view showing the periphery of the base of the robot. FIG. 43 is a perspective view of the first arm according to Embodiment 14. FIG. 44 is a perspective view showing a state of assembling two main body portions. FIG. 45 is a perspective view of the first arm before forming the joint portion. FIG. 46 is a cross-sectional view taken along the line K-K of FIG. 45. FIG. 47 is a perspective view of the first arm according to Embodiment 15. FIG. 48 is a perspective view showing a state of assembling two main body portions. FIG. 49 is a perspective view of the first arm before forming the joint portion. FIG. 50 is a cross-sectional view taken along the line L-L of FIG. 49. FIG. 51 is a perspective view of the first arm according to Embodiment 16. FIG. 52 is a perspective view showing a state of assembling two main body portions. FIG. 53 is a perspective view of the first arm before forming the joint portion. FIG. 54 is a cross-sectional view taken along the line M-M of FIG. 53. 【0008】 [Description of Embodiments of the Present Disclosure] First, the embodiments of the present disclosure will be listed and described. [1] The robot of the present disclosure includes a base and an arm movably supported with respect to the base, and at least one of the arm and the base has a main body portion including a pair of opposing walls facing each other, a connecting wall connecting the pair of opposing walls, and a rib connected to at least one of the pair of opposing walls and the connecting wall. The pair of opposing walls and the rib extend in the thickness direction of the connecting wall, and an opening that opens in the thickness direction of the connecting wall is formed in the main body portion. 【0009】 According to such a configuration, it is possible to provide a robot having a main body portion that is easy to ensure strength and easy to mold. Specifically, the main body portion can be easily provided by sliding a mold in the thickness direction of the connecting wall. 【0010】[2] In the above [1], it is preferable that the connecting wall is connected to the pair of opposing walls and the ends of the ribs in the thickness direction of the connecting wall. 【0011】 According to such a configuration, by sliding the mold on one side in the thickness direction of the connecting wall, the main body portion can be easily molded. 【0012】 [3] In the above [1], it is preferable that the connecting wall is connected to the pair of opposing walls and near the central portion of the ribs in the thickness direction of the connecting wall. 【0013】 According to such a configuration, the strength of the main body portion can be further enhanced. 【0014】 [4] In any one of the above [1] to [3], the arm has the main body portion, the connecting wall and the pair of opposing walls extend in a first direction which is the extending direction of the arm, and it is preferable that the main body portion has a tapered portion whose dimension in a direction orthogonal to the first direction of the main body portion decreases as it goes toward one side in the first direction. 【0015】 According to such a configuration, by providing a tapered portion on the arm, it becomes possible to reduce the weight and inertia of the arm. 【0016】 [5] In any one of the above [1] to [4], it is preferable that the main body portion has a through hole penetrating the connecting wall. 【0017】 According to such a configuration, by allowing air to pass through the through hole, it becomes easier to cool the main body portion. 【0018】 [6] The robot according to any one of the above [1] to [5] preferably further includes a plate portion attached to the main body portion so as to close the opening. 【0019】 According to such a configuration, it is possible to suppress dust from accumulating inside the opening by the plate portion. Also, by providing the plate portion, the rigidity of the main body portion can be further enhanced. 【0020】[7] Any one of the robots according to [1] to [5] above further includes a resin plate portion attached to the main body portion so as to close the opening, and the plate portion preferably includes a knockout portion capable of forming a communication hole communicating with the opening. 【0021】 According to such a configuration, by mass-producing the robot provided with the plate portion, it is possible to reduce the manufacturing cost of the robot in which dust accumulation inside the opening is suppressed. Further, when dust may enter the inside of the opening, by forming the communication hole, the opening can be opened and the heat dissipation property of the robot can be kept good. 【0022】 [8] Any one of the robots according to [1] to [7] above further includes a motor and a motor holder, the arm has the main body portion, and the motor is preferably fixed to one of the pair of opposing walls of the arm via the motor holder. 【0023】 According to such a configuration, the heat of the motor can be dissipated to the main body portion via the motor holder. 【0024】 [9] The robot according to [8] above further includes a ball screw nut and a ball screw nut holder, the arm has the main body portion, and the ball screw nut is preferably fixed to one of the pair of opposing walls of the arm via the ball screw nut holder. 【0025】 According to such a configuration, the heat of the ball screw nut can be dissipated to the main body portion via the ball screw nut holder. 【0026】

[10] The robot according to [9] above further includes a cover that covers at least a part of the motor holder and the ball screw nut holder, the cover includes a first cover wall parallel to the pair of opposing walls, and the motor holder and the ball screw nut holder are preferably fixed to the first cover wall. 【0027】With such a configuration, the heat of the motor can be dissipated to the cover through the motor holder. The heat of the ball screw nut can be dissipated to the cover through the ball screw nut holder. 【0028】

[11] Any one of the robots from [1] to

[10] further includes a motor for rotating the arm with respect to the base and a speed reducer, and the arm has the main body portion and a blower provided on the pair of opposing walls. It is preferable that the blower generates an air flow around the motor and the speed reducer by the rotation of the arm. 【0029】 With such a configuration, when the arm rotates, the motor and the speed reducer can be cooled. 【0030】

[12] In the above

[11] , it is preferable that the blower includes an inclined wall inclined with respect to the extending direction of the arm. 【0031】 With such a configuration, an air flow is likely to occur around the motor and the speed reducer. 【0032】

[13] In the above

[11] or

[12] , it is preferable that the blower is integrally formed with the main body portion. 【0033】 With such a configuration, by providing the blower, the strength of the main body portion can be increased. 【0034】

[14] The robot of the above [5] further includes a fan attached to the base, the base has the main body portion, and it is preferable that the fan generates wind passing through the through hole. 【0035】 With such a configuration, the base can be cooled. 【0036】

[15] The robot of the above

[14] further includes a wiring box attached to the base, and it is preferable that the wiring box is closed so as not to communicate with the opening. 【0037】 With such a configuration, it is possible to prevent dust from entering the wiring box by the wind generated by the fan. 【0038】

[16] In [2] above, it is preferable that two or more of the main body parts are provided, and the two main body parts are assembled in the thickness direction of the connecting wall. 【0039】 According to such a configuration, the strength of the robot can be further enhanced without impairing the ease of molding. 【0040】 [Details of Embodiments of the Present Disclosure] Embodiments of the present disclosure will be described below. Note that the present disclosure is not limited to these examples, and is intended to be indicated by the claims and to include all modifications within the meaning and scope equivalent to the claims. In the following description, for a plurality of identical members, only some members may be assigned reference numerals, and the reference numerals of other members may be omitted. 【0041】 In each drawing, for convenience of explanation, a part of the configuration may be shown exaggeratedly or simplified. Also, the dimensional ratios of each part may be different in each drawing. Also, "parallel", "perpendicular", and "orthogonal" in this specification include not only the cases of being strictly parallel, perpendicular, or orthogonal, but also the cases of being generally parallel, perpendicular, or orthogonal within the range where the actions and effects in the present embodiment are exhibited. 【0042】 "Opposite" in this specification means that surfaces or members are in a position facing each other, and includes not only the case where they are completely in a facing position, but also the case where they are partially in a facing position. Also, "opposite" in this specification includes both the case where a member different from the two parts is interposed between the two parts and the case where nothing is interposed between the two parts. 【0043】[Embodiment 1] <Overall Configuration of Robot> Embodiment 1 of the present disclosure will be described with reference to FIGS. 1 to 11. In this embodiment, a scalar robot 100 is illustrated. As shown in FIG. 1, the robot 100 includes a base 10, a first arm 20 that is supported so as to be rotatable about a first axis A1 extending vertically with respect to the base 10, a second arm 30 that is supported so as to be rotatable about a second axis A2 extending vertically with respect to the first arm 20, and an operating axis 40 that is supported by the second arm 30 so as to be rotatable and movable in the vertical direction. Here, the first arm 20 and the second arm 30 are examples of arms. 【0044】 The robot 100 includes a first motor 50, a first speed reducer 51, a second motor 52, a second speed reducer 53, a third motor 54, and a fourth motor 55. The first motor 50 is a drive source that generates a driving force for driving the first arm 20. The first speed reducer 51 is configured to reduce the rotation of the first motor 50. The second motor 52 is a drive source that generates a driving force for driving the second arm 30. The second speed reducer 53 is configured to reduce the rotation of the second motor 52. The third motor 54 is a drive source for driving a lifting device that raises and lowers the operating axis 40. The fourth motor 55 is a drive source for driving a rotational drive device that rotates the operating axis 40. 【0045】 The robot 100 includes a cable C1 spanned between the base 10 and the second arm 30. The cable C1 has, for example, a plurality of wirings and the like and a sheath that collectively covers them. 【0046】<First Arm> The first arm 20 is made of, for example, aluminum. As shown in FIGS. 2 to 4, the first arm 20 has an elongated shape. The first arm 20 has a main body portion 21. As shown in FIG. 3, the main body portion 21 includes an upper wall 22 and a lower wall 23 that face each other in the extending direction (vertical direction) of the first axis A1, a connecting wall 24 that connects the upper wall 22 and the lower wall 23, and ribs 25 that are connected to at least one of the upper wall 22 and the lower wall 23 and the connecting wall 24. The upper wall 22 and the lower wall 23 are an example of a pair of opposing walls. The ribs 25 are plate-shaped and are formed in plurality. The upper wall 22, the lower wall 23, and the ribs 25 extend in the thickness direction of the connecting wall 24. The upper wall 22, the lower wall 23, and the connecting wall 24 have a shape that is long in the extending direction of the first arm 20. 【0047】 FIGS. 5 and 6 are cross-sections of the main body portion 21 and show a cross-section orthogonal to the extending direction of the first arm 20. As shown in FIGS. 5 and 6, the connecting wall 24 is disposed near the central portion of the upper wall 22, the lower wall 23, and the ribs 25 in the thickness direction (the left-right direction in the drawing) of the connecting wall 24. Therefore, the cross-section formed by the upper wall 22, the lower wall 23, and the connecting wall 24 has an I-shaped (a shape obtained by rotating an H-shaped by 90°) shape. The main body portion 21 has an opening 26 that opens in the thickness direction of the connecting wall 24. The opening 26 is formed by the upper wall 22, the lower wall 23, and the ribs 25. 【0048】 The first arm 20 can be formed by die casting using a slide. Specifically, the main body portion 21 can be formed by sliding a mold in the thickness direction of the connecting wall 24. Therefore, the first arm 20 of the present embodiment can be easily formed while maintaining the strength as compared with a box-shaped arm of a conventional configuration. 【0049】 As shown in FIG. 3, the main body portion 21 may include end walls 27A and 27B that connect the ends of the upper wall 22, the lower wall 23, and the connecting wall 24 in the extending direction of the first arm 20. 【0050】As shown in FIGS. 2 to 4, the first arm 20 has a first joint portion 28 arranged at one end on the extending direction of the first arm 20 of the main body portion 21, and a second joint portion 29 arranged at one end on the extending direction of the first arm 20 of the main body portion 21. The first joint portion 28 and the second joint portion 29 may be formed, for example, after forming the main body portion 21. As shown in FIG. 1, the first joint portion 28 is a configuration for connecting the first arm 20 to the base 10. The second joint portion 29 is a configuration for connecting the first arm 20 to the second arm 30. 【0051】 <Second Arm> The second arm 30 is made of, for example, aluminum. As shown in FIGS. 7 to 9, the second arm 30 has an elongated shape. The second arm 30 has a main body portion 31. As shown in FIG. 8, the main body portion 31 includes an upper wall 32 and a lower wall 33 facing each other in the extending direction (vertical direction) of the second axis A2, a connecting wall 34 connecting the upper wall 32 and the lower wall 33, and ribs 35 connected to at least one of the upper wall 32 and the lower wall 33 and the connecting wall 34. The upper wall 32 and the lower wall 33 are an example of a pair of opposing walls. The ribs 35 are plate-shaped and are formed in plurality. The upper wall 32, the lower wall 33, and the ribs 35 extend in the thickness direction of the connecting wall 24. The upper wall 32, the lower wall 33, and the connecting wall 34 have a shape that is long in the extending direction of the second arm 30. 【0052】 FIGS. 10 and 11 are cross-sections of the main body portion 31, showing a cross-section orthogonal to the extending direction of the second arm 30. As shown in FIGS. 10 and 11, the connecting wall 34 is arranged near the central portion of the upper wall 32, the lower wall 33, and the ribs 35 in the thickness direction (left-right direction in the drawing) of the connecting wall 34. Therefore, the cross-section formed by the upper wall 32, the lower wall 33, and the connecting wall 34 is in an I-shaped (a shape obtained by rotating an H-shaped by 90°). The main body portion 31 has an opening 36 that opens in the thickness direction of the connecting wall 34. The opening 36 is formed by the upper wall 32, the lower wall 33, and the ribs 35. 【0053】The second arm 30 can be formed by die casting using a slide. Specifically, the main body portion 31 can be formed by sliding a mold in the thickness direction of the connecting wall 34. Therefore, compared with the box-shaped arm of the conventional configuration, the second arm 30 of the present embodiment can be easily formed while maintaining its strength. 【0054】 As shown in FIG. 8, the main body portion 31 may include end walls 37A and 37B that connect the ends of the upper wall 32, the lower wall 33, and the connecting wall 34 in the extending direction of the second arm 30. 【0055】 As shown in FIGS. 7 to 9, the second arm 30 has a first joint portion 38 disposed at one end in the extending direction of the second arm 30 of the main body portion 31 and a second joint portion 39 disposed at one end in the extending direction of the second arm 30 of the main body portion 31. The first joint portion 38 and the second joint portion 39 may be formed, for example, after forming the main body portion 31. As shown in FIG. 1, the first joint portion 38 is a configuration for connecting the second arm 30 to the first arm 20. The second joint portion 39 is a configuration for connecting the second arm 30 to the operating shaft 40. 【0056】 The base 10 has a box shape and houses the wiring of the cable C1 inside. The base 10 is fixed to a predetermined installation surface. A joint portion 10J is provided at the upper end of the base 10. The joint portion 10J is a configuration for connecting the base 10 to the first arm 20. 【0057】[Effects of Embodiment 1] (1-1) As described above, the robot 100 of Embodiment 1 includes a base 10, a first arm 20, and a second arm 30 that are movably supported with respect to the base 10. The first arm 20 has a main body portion 21 including upper and lower walls 22 and 23 facing each other, a connecting wall 24 connecting the upper and lower walls 22 and 23, and ribs 25 connected to at least one of the upper and lower walls 22 and 23 and the connecting wall 24. The upper wall 22, the lower wall 23, and the ribs 25 extend in the thickness direction of the connecting wall 24, and an opening 26 that opens in the thickness direction of the connecting wall 24 is formed in the main body portion 21. The second arm 30 has a main body portion 31 including upper and lower walls 32 and 33 facing each other, a connecting wall 34 connecting the upper and lower walls 32 and 33, and ribs 35 connected to at least one of the upper and lower walls 32 and 33 and the connecting wall 34. The upper wall 32, the lower wall 33, and the ribs 35 extend in the thickness direction of the connecting wall 34, and an opening 36 that opens in the thickness direction of the connecting wall 34 is formed in the main body portion 31. 【0058】 According to such a configuration, it is possible to provide a robot 100 having main body portions 21 and 31 that are easy to ensure strength and easy to mold. Specifically, the main body portions 21 and 31 can be easily provided by sliding a mold in the thickness direction of the connecting walls 24 and 34. 【0059】 In Embodiment 1, the connecting wall 24 is connected near the central portions of the upper wall 22, the lower wall 23, and the ribs 25 in the thickness direction of the connecting wall 24, and the connecting wall 34 is connected near the central portions of the upper wall 32, the lower wall 33, and the ribs 35 in the thickness direction of the connecting wall 34. 【0060】 According to such a configuration, the strength of the main body portions 21 and 31 can be further enhanced. 【0061】 [Embodiment 2] Embodiment 2 of the present disclosure will be described while referring to FIGS. 12 to 14. In the robot 200 of Embodiment 2, the configuration of the base 210 is different from that of Embodiment 1. Since the other configurations and effects are the same as those of Embodiment 1, the same reference numerals as those in Embodiment 1 are given to the members equivalent to those in Embodiment 1, and detailed descriptions are omitted. 【0062】<Base> The base 210 is made of, for example, aluminum. As shown in FIGS. 12 to 14, the base 210 has a main body portion 211. As shown in FIGS. 13 and 14, the main body portion 211 includes a right wall 212 and a left wall 213 that face each other in the left-right direction, a connecting wall 214 that connects the right wall 212 and the left wall 213, and ribs 215 that are connected to at least one of the right wall 212 and the left wall 213 and the connecting wall 214. The right wall 212 and the left wall 213 are an example of a pair of opposing walls. The ribs 215 are plate-shaped and are formed in plurality. The right wall 212, the left wall 213, and the ribs 215 extend in the thickness direction of the connecting wall 214. The right wall 212, the left wall 213, and the connecting wall 214 have a shape that is long in the extending direction (vertical direction) of the first axis A1. 【0063】 As shown in FIG. 13, the connecting wall 214 is connected to the ends (specifically, the front ends) of the right wall 212, the left wall 213, and the ribs 215 in the thickness direction (front-rear direction, left-right direction in the drawing) of the connecting wall 214. Therefore, the cross-section formed by the right wall 212, the left wall 213, and the connecting wall 214 is an angular C shape. As shown in FIG. 14, the main body portion 211 has an opening 216 that opens in the thickness direction of the connecting wall 214. The opening 216 is constituted by the right wall 212, the left wall 213, and the ribs 215. 【0064】 The base 210 can be formed by die-casting using a slide. Specifically, the main body portion 211 can be formed by sliding the mold in the thickness direction of the connecting wall 214. Therefore, the base 210 of the present embodiment can be easily formed while maintaining the strength as compared with the conventional box-shaped base. 【0065】 As shown in FIG. 14, the main body portion 211 may include an end wall 217 that connects the lower ends of the right wall 212, the left wall 213, and the connecting wall 214. The end wall 217 is adapted to be fixed to the installation surface. A joint portion 218 may be provided at the upper end portion of the main body portion 211. The joint portion 218 is a configuration for connecting the base 210 to the first arm 20. 【0066】As shown in FIGS. 13 and 14, a wiring box 56 may be attached to the base 210. The wiring box 56 has an internal space 56A for accommodating the wiring of the cable C1, and the internal space 56A and the opening 216 of the main body 211 are defined. That is, the internal space 56A and the opening 216 do not communicate with each other. 【0067】 [Operation and Effect of Embodiment 2] (2-1) The robot 200 of Embodiment 1 includes a base 210, a first arm 20 and a second arm 30 that are movably supported with respect to the base 210. The base 210 has a main body 211 including a right wall 212 and a left wall, 213 facing each other, a connecting wall 214 connecting the right wall 212 and the left wall 213, and a rib 215 connected to at least one of the right wall 212 and the left wall 213 and the connecting wall 214. The right wall 212, the left wall 213, and the rib 215 extend in the thickness direction of the connecting wall 214, and an opening 216 that opens in the thickness direction of the connecting wall 214 is formed in the main body 211. 【0068】 According to such a configuration, it is possible to provide a robot 200 having a main body 211 that is easy to ensure strength and easy to mold. Specifically, the main body 211 can be easily provided by sliding the mold in the thickness direction of the connecting wall 214. 【0069】 (2-2) In Embodiment 2, the connecting wall 214 is connected to the ends of a pair of the right wall 212, the left wall 213, and the rib 215 in the thickness direction of the connecting wall 214. 【0070】 According to such a configuration, the main body 211 can be easily molded by sliding the mold to one side in the thickness direction of the connecting wall 214. 【0071】 [Embodiment 3] Embodiment 3 of the present disclosure will be described with reference to FIGS. 15 and 16. In the robot 300 of Embodiment 3, the configuration of the base 310 is different from that of Embodiment 1. Since the other configurations and operation and effects are the same as those of Embodiment 1, the same reference numerals as those in Embodiment 1 are assigned to the members equivalent to those in Embodiment 1, and detailed description thereof is omitted. 【0072】<Base> The base 310 is made of, for example, aluminum. As shown in FIGS. 15 and 16, the base 310 has a main body portion 311. As shown in FIG. 16, the main body portion 311 includes a front wall 312 and a rear wall 313 that face each other in the front-rear direction, a connecting wall 314 that connects the front wall 312 and the rear wall 313, and ribs 315 that are connected to at least one of the front wall 312 and the rear wall 313 and the connecting wall 314. The front wall 312 and the rear wall 313 are an example of a pair of opposing walls. The ribs 315 are plate-shaped and a plurality of them are formed. The front wall 312, the rear wall 313, and the ribs 315 extend in the thickness direction of the connecting wall 314. The front wall 312, the rear wall 313, and the connecting wall 314 have a shape that is long in the extending direction (vertical direction) of the first axis A1. 【0073】 The connecting wall 314 is disposed near the central portion of the front wall 312, the rear wall 313, and the ribs 315 in the thickness direction (left-right direction, vertical direction in the drawing) of the connecting wall 314. Therefore, the cross section formed by the front wall 312, the rear wall 313, and the connecting wall 314 is an I-shape (or H-shape). The main body portion 311 has an opening 316 that opens in the thickness direction of the connecting wall 314. The opening 316 is formed by the front wall 312, the rear wall 313, and the ribs 315. 【0074】 The base 310 can be formed by die casting using a slide. Specifically, the main body portion 311 can be formed by sliding the mold in the thickness direction of the connecting wall 314. Therefore, the base 310 of the present embodiment can be easily formed while maintaining the strength as compared with a box-shaped base of a conventional configuration. 【0075】 As shown in FIG. 15, the main body portion 311 may include an end wall 317 that connects the lower end portions of the front wall 312, the rear wall 313, and the connecting wall 314. The end wall 317 is adapted to be fixed to the installation surface. A joint portion 3 may be provided at the upper end portion of the main body portion 311. The joint portion 318 is a configuration for connecting the base 310 to the first arm 20. 【0076】[Embodiment 4] Embodiment 4 of the present disclosure will be described with reference to FIGS. 17 and 18. The robot of Embodiment 4 is configured in the same manner as Embodiment 1 except for the configuration of the first arm 420. Hereinafter, only the configuration of the first arm 420 will be described. 【0077】 <First Arm> The first arm 420 is made of, for example, aluminum. As shown in FIG. 17, the first arm 420 has an elongated shape. The first arm 420 includes a main body portion 421. The main body portion 421 includes a first portion 421A, a second portion 421B, and a tapered portion 421C. The first portion 421A, the second portion 421B, and the tapered portion 421C are connected in a first direction, which is the extending direction of the first arm 420. The tapered portion 421C connects the first portion 421A and the second portion 421B. Hereinafter, with the first direction being the front-rear direction and assuming that the first portion 421A is arranged at the rear end portion of the first arm 420, the configurations of the first portion 421A, the second portion 421B, and the tapered portion 421C will be described. 【0078】 As shown in FIG. 17, a first joint portion 28 is provided in the first portion 421A. The first portion 421A includes an upper wall 422A and a lower wall 423A that face each other in the extending direction of the first axis A1 (vertical direction), a connecting wall 424A that connects the upper wall 422A and the lower wall 423A, and ribs 425A that are connected to at least one of the upper wall 422A and the lower wall 423A and the connecting wall 424A. The upper wall 422A and the lower wall 423A are an example of a pair of opposing walls. The upper wall 422A, the lower wall 423A, and the ribs 425A extend in the thickness direction of the connecting wall 424A. The upper wall 422A, the lower wall 423A, and the connecting wall 424A extend in the front-rear direction. 【0079】 Although not shown in detail, the connecting wall 424A is arranged near the central portion of the upper wall 422A, the lower wall 423A, and the ribs 425A in the thickness direction (left-right direction) of the connecting wall 424A. Therefore, the cross section formed by the upper wall 422A, the lower wall 423A, and the connecting wall 424A is an I-shaped (a shape obtained by rotating an H-shaped by 90°). The first portion 421A has an opening 426A that opens in the thickness direction of the connecting wall 424A. The opening 426A is formed by the upper wall 422A, the lower wall 423A, and the ribs 425A. 【0080】 As shown in FIG. 17, the first portion 421A may include an end wall 427A that connects the rear end portions of the upper wall 422A, the lower wall 423A, and the connecting wall 424A. 【0081】 The second portion 421B is smaller in size in the vertical direction than the first portion 421A. A second joint portion 29 is provided in the second portion 421B. Similar to the first portion 421A, the second portion 421B includes an upper wall 422B and a lower wall 423B (an example of a pair of opposing walls), a connecting wall 424B, and a rib 425B. The cross-section formed by the upper wall 422B, the lower wall 423B, and the connecting wall 424B has an I-shaped (a shape obtained by rotating an H-shaped by 90°). The second portion 421B has an opening 426B that opens in the thickness direction of the connecting wall 424B. The opening 426B is formed by the upper wall 422B, the lower wall 423B, and the rib 425B. 【0082】 The second portion 421B may include an end wall 427B that connects the front end portions of the upper wall 422B, the lower wall 423B, and the connecting wall 424B. 【0083】 The tapered portion 421C includes an upper wall 422C and a lower wall 423C that face each other in the vertical direction, a connecting wall 424C that connects the upper wall 422C and the lower wall 423C, and a rib 425C that is connected to at least one of the upper wall 422C and the lower wall 423C and the connecting wall 424C. The upper wall 422C and the lower wall 423C are an example of a pair of opposing walls. The upper wall 422C, the lower wall 423C, and the rib 425C extend in the thickness direction of the connecting wall 424C. The upper wall 422C, the lower wall 423C, and the connecting wall 424C extend in the front-rear direction. 【0084】 The upper wall 422C is inclined downward as it goes forward. The lower wall 423C is inclined upward as it goes forward. Therefore, the upper wall 422C and the lower wall 423C are inclined so as to approach each other in the vertical direction as they go forward. The rear end portion of the upper wall 422C is connected to the front end portion of the upper wall 422A. The front end portion of the upper wall 422C is connected to the rear end portion of the upper wall 422B. The rear end portion of the lower wall 423C is connected to the front end portion of the lower wall 423A. The front end portion of the lower wall 423C is connected to the rear end portion of the lower wall 423B. 【0085】 As shown in FIG. 18, the connecting wall 424C is disposed near the central portions of the upper wall 422C, the lower wall 423C, and the rib 425C in the thickness direction (left - right direction) of the connecting wall 424C. Therefore, the cross - section formed by the upper wall 422C, the lower wall 423C, and the connecting wall 424C is in an I - shape (a shape obtained by rotating an H - shape by 90°). The tapered portion 421C has an opening 426C that opens in the thickness direction of the connecting wall 424C. The opening 426C is formed by the upper wall 422C, the lower wall 423C, and the rib 425C. 【0086】 As shown in FIG. 17, the connecting wall 424C has a smaller dimension in the vertical direction as it goes forward. The rear end portion of the connecting wall 424C is connected to the front end portion of the connecting wall 424A. The front end portion of the connecting wall 424C is connected to the rear end portion of the connecting wall 424B. 【0087】 As shown in FIG. 18, the tapered portion 421C may include outer ribs 424C1 and 424C2 that extend vertically from the upper wall 422C and the lower wall 423C and are arranged at the same position as the connecting wall 424C in the left - right direction. The outer rib 424C1 extends upward from the upper wall 422C. The outer rib 424C2 extends downward from the lower wall 423C. 【0088】 The first arm 420 can be formed by die - casting using a slide. Specifically, by sliding the mold in the left - right direction, the first part 421A, the second part 421B, and the tapered portion 421C can be formed. Therefore, the first arm 420 of the present embodiment can be easily formed while maintaining the strength as compared with the box - shaped arm of the conventional configuration. 【0089】 In the present embodiment, the height (dimension in the direction orthogonal to the first direction) of the first arm 420 is not constant but changes in the extending direction (the first direction, the front - rear direction) of the first arm 420. Specifically, the height of the first arm 420 becomes smaller as it goes forward (one side of the first direction). According to such a configuration, weight reduction and low inertia of the first arm 420 can be achieved. 【0090】[Operation and Effect of Embodiment 4] (4-1) In Embodiment 4, the first arm 420 has a main body portion 421, and the connecting walls 424A, 424B, 424C and a pair of opposing walls (upper walls 422A, 422B, 422C and lower walls 423A, 423B, 423C) extend in the first direction (front-rear direction) which is the extending direction of the first arm 420, and the main body portion 421 has a tapered portion 421C in which the dimension in the direction orthogonal to the first direction of the main body portion 421 becomes smaller as it goes toward one side (front) in the first direction. 【0091】 According to such a configuration, by providing the tapered portion 421C on the first arm 420, it becomes possible to reduce the weight and inertia of the first arm 420. 【0092】 [Embodiment 5] Embodiment 5 of the present disclosure will be described while referring to FIG. 19. In the robot 500 of Embodiment 5, different from Embodiment 1, through holes 524H and 534H are provided in the main body portions 521 and 531, respectively. Regarding other configurations and operation and effects, since they are the same as those in Embodiment 1, the same reference numerals as those in Embodiment 1 are given to the members equivalent to those in Embodiment 1, and detailed description is omitted. 【0093】 As shown in FIG. 19, the robot 500 includes a base 10, a first arm 520, and a second arm 530. The main body portion 521 of the first arm 520 has a through hole 524H penetrating through the connecting wall 24. The through hole 524H penetrates the connecting wall 24 in the thickness direction of the connecting wall 24 and communicates with the opening 26. The main body portion 531 of the second arm 530 has a through hole 534H penetrating through the connecting wall 34. The through hole 534H penetrates the connecting wall 34 in the thickness direction of the connecting wall 34 and communicates with the opening 36. 【0094】 By providing the through holes 524H and 534H in the main body portions 521 and 531, respectively, when air passes through the through holes 524H and 534H, it becomes easier to cool the main body portions 521 and 531. In particular, since the through hole 524H and the through hole 534H are provided in the first arm 520 and the second arm 530 that horizontally pivot with respect to the base 10, air easily passes through the through holes 524H and 534H due to the operation of the robot 500, and the cooling effect of the first arm 520 and the second arm 530 is enhanced. 【0095】 Also, a rope can be passed through the through holes 524H and 534H, and the robot 500 can be transported by a hoist. 【0096】 [Operation and Effect of Embodiment 5] (5-1) In the robot 500 of Embodiment 5, the main body parts 521 and 531 have through holes 524H and 534H that penetrate the connecting walls 24 and 34, respectively. 【0097】 With such a configuration, when wind passes through the through holes 524H and 534H, it becomes easier to cool the main body parts 521 and 531. 【0098】 [Embodiment 6] Embodiment 6 of the present disclosure will be described while referring to FIG. 20. The robot 600 of Embodiment 6 includes a base 610. The base 610 is configured in the same manner as the base 210 of Embodiment 2, except that a through hole 614H is provided. Hereinafter, members equivalent to those in Embodiment 2 are denoted by the same reference numerals as in Embodiment 2, and detailed description thereof will be omitted. 【0099】 As shown in FIG. 20, the main body part 611 of the base 610 has a through hole 614H that penetrates the connecting wall 214. The through hole 614H penetrates the connecting wall 214 in the thickness direction (front-rear direction) of the connecting wall 214 and communicates with the opening 216. 【0100】 By providing the through hole 614H in the main body part 611, when wind passes through the through hole 614H, it becomes easier to cool the main body part 611. 【0101】 Also, a rope can be passed through the through hole 614H, and the robot 600 can be transported by a hoist. 【0102】 [Embodiment 7] Embodiment 7 of the present disclosure will be described while referring to FIG. 21. The robot 700 of Embodiment 7 includes a base 710. The base 710 is configured in the same manner as the base 310 of Embodiment 3, except that a through hole 714H is provided. Hereinafter, members equivalent to those in Embodiment 3 are denoted by the same reference numerals as in Embodiment 3, and detailed description thereof will be omitted. 【0103】As shown in FIG. 21, the main body portion 711 of the base 710 has a through hole 714H that penetrates the connecting wall 314. The through hole 714H penetrates the connecting wall 314 in the thickness direction (left - right direction) of the connecting wall 314 and communicates with the opening 316. 【0104】 By providing the through holes 714H in the main body portion 711 respectively, when wind passes through the through holes 714H, it becomes easier to cool the main body portion 711. Also, a rope can be passed through the through hole 714H, and the robot 700 can be transported by a hoist. 【0105】 [Embodiment 8] The eighth embodiment of the present disclosure will be described while referring to FIGS. 22 and 23. The robot 800 of Embodiment 8 includes a plate portion 860 in addition to the configuration of the robot 100 of Embodiment 1. For other configurations, functions, and effects, since they are the same as those of Embodiment 1, the same reference numerals as those in Embodiment 1 are assigned to the members equivalent to those in Embodiment 1, and detailed descriptions are omitted. 【0106】 The plate portion 860 is, for example, made of metal. As shown in FIG. 22, the plate portion 860 is attached to the first arm 20 by bolt fastening or the like. As shown in FIG. 23, the plate portion 860 has a plate shape. The plate portion 860 closes the opening 26 of the main body portion 21. 【0107】 In this embodiment, by providing the plate portion 860, it is possible to suppress dust from accumulating inside the opening 26 of the main body portion 21. Therefore, a robot 800 suitable for use in a clean room or the like can be provided. Also, by attaching the plate portion 860 to the main body portion 21, the rigidity of the main body portion 21 can be further enhanced. 【0108】 [Function and Effect of Embodiment 8] (8 - 1) The robot 800 of Embodiment 8 further includes a plate portion 860 attached to the main body portion 21 so as to close the opening (26). 【0109】 According to such a configuration, the plate portion 860 can suppress dust from accumulating inside the opening 26. Also, by providing the plate portion 860, the rigidity of the main body portion 21 can be further enhanced. 【0110】 [Embodiment 9] Embodiment 9 of the present disclosure will be described while referring to FIGS. 24 to 27. The robot 900 of Embodiment 9 includes a resin plate portion 960 in addition to the configuration of the robot 100 of Embodiment 1. Since the other configurations and functions and effects are the same as those of Embodiment 1, the same reference numerals as those in Embodiment 1 are assigned to the members equivalent to those in Embodiment 1, and detailed descriptions thereof are omitted. 【0111】 As shown in FIG. 24, the plate portion 960 is attached to the first arm 20 by bolt fastening or the like. As shown in FIG. 25, the plate portion 960 has a plate shape. The plate portion 960 closes the opening 26 of the main body portion 21. The plate portion 960 has a knockout portion 961 at a portion facing the opening 26. By applying stress to the knockout portion 961 of the plate portion 960 and removing the knockout portion 961, a communication hole 962 (see FIGS. 26 and 27) can be formed in a portion corresponding to the knockout portion 961. The knockout portion 961 is formed thinner, for example, than other portions of the plate portion 960. 【0112】 FIGS. 26 and 27 show the plate portion 960 in which the communication hole 962 has been formed. The communication hole 962 communicates with the opening 26. 【0113】 In the present embodiment, when the communication hole 962 is not formed in the plate portion 960, it is possible to suppress dust from accumulating inside the opening 26 of the main body portion 21. Therefore, it is possible to provide a robot 900 suitable for use in a clean room or the like (hereinafter referred to as a clean specification). Further, when the communication hole 962 is formed in the plate portion 960, air easily passes through the opening 26 and the heat dissipation property is not impaired. 【0114】According to this embodiment, the robot 900 can be made clean by not forming the communication hole 962. On the other hand, when it is not a clean specification, by forming the communication hole 962, the air can easily pass through the opening 26, and the heat dissipation of the robot 900 can be kept good. Thus, although the robot 900 includes the plate portion 960, since the knockout portion 961 is provided in the plate portion 960, it can also be used for applications other than clean rooms. Therefore, it becomes easy to suppress the manufacturing cost of the clean room specification robot 900. 【0115】 [Operational Effects of Embodiment 9] (9-1) The robot 900 of Embodiment 9 further includes a resin plate portion 960 attached to the main body portion 21 so as to close the opening 26. The plate portion 960 includes a knockout portion 961 capable of forming a communication hole 962 communicating with the opening 26. 【0116】 According to such a configuration, by mass-producing the robot 900 provided with the plate portion 960, it is possible to reduce the manufacturing cost of the robot 900 in which dust is suppressed from accumulating inside the opening 26. Also, when dust may enter the inside of the opening 26, by forming the communication hole 962, the opening 26 can be opened, and the heat dissipation of the robot 900 can be kept good. 【0117】 [Embodiment 10] Embodiment 10 of the present disclosure will be described while referring to FIGS. 28 to 35. The robot 100 of Embodiment 10 is configured substantially the same as the robot 500 of Embodiment 5. As shown in FIG. 32, the robot 1000 includes a first arm 520, a second arm 530, and an operating shaft 40. Hereinafter, the same members as those in Embodiment 5 will be denoted by the same reference numerals as those in Embodiment 5, and detailed description will be omitted. In this embodiment, the second motor 52, the third motor 54, and the fourth motor 55 are examples of motors. The second motor holder 52H, the third motor holder 54H, and the fourth motor holder 55H are examples of motor holders. The second arm 530 is an example of an arm. 【0118】As shown in FIG. 28, the robot 1000 includes a second motor 52, a second motor holder 52H, a third motor 54, a third motor holder 54H, a fourth motor 55, and a fourth motor holder 55H. The second motor 52 is fixed to the second arm 530 via the second motor holder 52H. The third motor 54 is fixed to the second arm 530 via the third motor holder 54H. The fourth motor 55 is fixed to the second arm 530 via the fourth motor holder 55H. Each of the motor holders 52H, 54H, and 55H is, for example, made of metal. Each of the motor holders 52H, 54H, and 55H is fixed to the upper wall 32 of the main body portion 531 of the second arm 530, for example, by bolt fastening. 【0119】 As shown in FIG. 32, the first joint portion 38 of the second arm 530 has a cylindrical portion 38A that penetrates the main body portion 531 in the vertical direction. The second motor 52 and the second motor holder 52H are disposed above the cylindrical portion 38A. Inside the cylindrical portion 38A, a second speed reducer 53 is disposed. The output portion 52A of the second motor 52 is connected to the input portion 53A of the second speed reducer 53. The output portion 53B of the second speed reducer 53 is fixed to the second arm 530, for example, by bolt fastening. The fixing portion 53C of the second speed reducer 53 is disposed inside the output portion 53B. The fixing portion 53C is fixed to the second joint portion 29 of the first arm 520, for example, by bolt fastening. 【0120】 The robot 1000 includes a ball screw nut 1041 and a spline nut 1042 attached to the operating shaft 40, and a ball screw nut holder 1041H and a fourth speed reducer 1043. The second joint portion 39 of the second arm 530 has a cylindrical portion 39A that penetrates the main body portion 531 in the vertical direction. The ball screw nut 1041 and the ball screw nut holder 1041H are disposed above the cylindrical portion 39A. Inside the cylindrical portion 39A, the fourth speed reducer 1043 is disposed. 【0121】The ball screw nut 1041 is configured to raise and lower the operating shaft 40. As shown in FIG. 28, the ball screw nut 1041 is fixed to the second joint portion 39 of the second arm 530 via a ball screw nut holder 1041H. The ball screw nut holder 1041H is fixed to the upper wall 32 of the main body portion 531 of the second arm 530, for example, by bolt fastening. The ball screw nut holder 1041H is made of, for example, metal. As shown in FIG. 32, pulleys P1 and P2 are respectively fixed to the ball screw nut 1041 and the output portion 54A of the third motor 54, and a belt B1 is stretched between the pulleys P1 and P2. Thus, as the third motor 54 rotates, the ball screw nut 1041 rotates and the operating shaft 40 moves up and down. 【0122】 The spline nut 1042 is configured to rotate the operating shaft 40. The fourth reduction gear 1043 is configured to reduce the rotation of the fourth motor 55. Pulleys P3 and P4 are respectively fixed to the input portion 1043A of the fourth reduction gear 1043 and the output portion 55A of the fourth motor 55, and a belt B2 is stretched between the pulleys P3 and P4. The fixed portion 1043B of the fourth reduction gear 1043 is fixed to the second joint portion 39 of the second arm 530, for example, by bolt fastening. The output portion 1043C of the fourth reduction gear 1043 is fixed to the spline nut 1042 via connecting members 1044A and 1044B. Thus, when the fourth motor 55 rotates, the rotation of the fourth motor 55 is reduced by the fourth reduction gear 1043 and transmitted to the spline nut 1042. Then, the operating shaft 40 rotates. 【0123】The robot 1000 includes a cover 1070 that covers at least a part of each of the motor holders 52H, 54H, 55H, and the ball screw nut holder 1041H. The cover 1070 includes a first cover wall 1071 parallel to the upper wall 32 and the lower wall 33 of the second arm 530, and a cover peripheral wall 1072 that connects between the first cover wall 1071 and the upper wall 32 of the second arm 530. As shown in FIG. 33, the motor holders 52H, 54H, 55H, and the ball screw nut holder 1041H are fixed to the first cover wall 1071. As shown in FIG. 29, the cover peripheral wall 1072 extends upward from the horizontal edge portion of the upper wall 32 of the second arm 530. The cover peripheral wall 1072 surrounds the motor holders 52H, 54H, 55H, and the ball screw nut holder 1041H in the horizontal direction. 【0124】 As shown in FIG. 30, a through hole 1071A is provided in the first cover wall 1071. As shown in FIG. 31, a wiring portion 1075 is attached to the cover 1070 so as to cover the through hole 1071A (see FIG. 30). The wiring portion 1075 is configured to draw the wiring of the cable C1 into the cover 1070. A bushing 1071B for drawing the wiring of each of the motors 52, 54, 55 into the cover 1070 is provided in the first cover wall 1071. 【0125】 In the present embodiment, each of the motor holders 52H, 54H, 55H is fixed to the second arm 530 and the first cover wall 1071. Therefore, the heat of each of the motors 52, 54, 55 is transmitted to the second arm 530 and the first cover wall 1071 through each of the motor holders 52H, 54H, 55H, making it easier to dissipate the heat of each of the motors 52, 54, 55. Further, the ball screw nut holder 1041H is fixed to the second arm 530 and the first cover wall 1071. Therefore, the heat of the ball screw nut 1041 is transmitted to the second arm 530 and the first cover wall 1071 through the ball screw nut holder 1041H, making it easier to dissipate the heat of the ball screw nut 1041. 【0126】As shown in FIG. 34 , the robot 1000 may further include a motor cover 1077 that covers the second motor 52, the third motor 54, and the fourth motor 55 (see FIG. 31 ). The motor cover 1077 may be attached to the first cover wall 1071. The motor cover 1077 may have a knockout portion 1077A. By applying stress to the knockout portion 1077A and removing it, a through-hole 1077B (see FIG. 35 ) can be formed in the portion corresponding to the knockout portion 1077A. The knockout portion 1077A may be formed thinner than other portions of the motor cover 1077, for example. By not providing the through-hole 1077B, dust and other particles can be prevented from being released from the motors 52, 54, and 55 to the outside of the robot 1000. This means that the robot 1000 can be designed to be clean. Furthermore, by providing the through holes 1077B, heat from the motors 52, 54, and 55 can be easily released to the outside. 【0127】 [Effects and Functions of Embodiment 10] (10-1) The robot 1000 of embodiment 10 further includes motors 52, 54, 55 and motor holders 52H, 54H, 55H, and the second arm 530 has a main body 531. The motors 52, 54, 55 are fixed to one of a pair of opposing walls of the second arm 530 (upper wall 32) via the motor holders 52H, 54H, 55H. 【0128】 With this configuration, heat from the motors 52, 54, and 55 can be dissipated to the main body 531 via the motor holders 52H, 54H, and 55H. 【0129】 (10-2) The robot 1000 of embodiment 10 further includes a ball screw nut 1041 and a ball screw nut holder 1041H, and the second arm 530 has a main body 531, and the ball screw nut 1041 is fixed to one of a pair of opposing walls of the second arm 530 (upper wall 32) via the ball screw nut holder 1041H. 【0130】 With this configuration, heat from the ball screw nut 1041 can be released to the main body 531 via the ball screw nut holder 1041H. 【0131】 (10-3) The robot 1000 of embodiment 10 further includes a cover 1070 that covers at least a portion of the motor holders 52H, 54H, 55H and the ball screw nut holder 1041H, and the cover 1070 includes a first cover wall 1071 that is parallel to a pair of opposing walls (upper wall 32 and lower wall 33), and the motor holders 52H, 54H, 55H and the ball screw nut holder 1041H are fixed to the first cover wall 1071. 【0132】 With this configuration, heat from the motors 52, 54, and 55 can be dissipated to the cover 1070 via the motor holders 52H, 54H, and 55H. Heat from the ball screw nut 1041 can be dissipated to the cover 1070 via the ball screw nut holder 1041H. 【0133】 [Embodiment 11] An eleventh embodiment of the present disclosure will be described with reference to Figures 36 to 39. A robot 1100 of embodiment 11 includes a blower 1180 in addition to the configuration of the robot 500 of embodiment 5. Since other configurations, actions, and effects are similar to those of embodiment 5, the same reference numerals as in embodiment 5 are used for equivalent members to those of embodiment 5, and detailed description thereof will be omitted. In this embodiment, the first arm 520 is an example of an arm. The first motor 50 is an example of a motor. The first reducer 51 is an example of a reducer. 【0134】As shown in FIG. 39 , the first joint 28 of the first arm 520 has a cylindrical portion 28A that vertically penetrates the main body 521. A portion of the first motor 50 and a first motor holder 50H are disposed inside the cylindrical portion 28A. A first reducer 51 is disposed below the cylindrical portion 28A. The first motor holder 50H is made of, for example, metal. The first motor holder 50H holds the first motor 50. The first motor holder 50H is fixed to a fixing portion 51A of the first reducer 51, for example, by bolting. The fixing portion 51A of the first reducer 51 is fixed to the joint 10J of the base 10, for example, by bolting. In other words, the first motor 50 is fixed to the base 10, not the first arm 520. The output portion 50A of the first motor 50 is connected to the input portion 51B of the first reducer 51. The output portion 51C of the first reducer 51 is fixed to the first joint portion 28 of the first arm 520 by, for example, bolting. 【0135】 36 , the blower 1180 includes a motor blower 1181 and a reducer blower 1182. The motor blower 1181 is provided on the upper wall 22 of the first arm 520. The motor blower 1181 has a shape that is elongated in the extension direction of the first arm 520. Two motor blowers 1181 are arranged side by side in a direction (hereinafter referred to as the width direction) that is perpendicular to both the extension direction of the first arm 520 and the extension direction of the first axis A1 (the up-down direction). 【0136】The motor blower 1181 includes a fixed wall 1181A, an inclined wall 1181B, a first guide wall 1181C, and a second guide wall 1181D. The fixed wall 1181A is substantially parallel to the upper wall 22 and is fixed to the upper wall 22 by, for example, bolting. The inclined wall 1181B extends upward from the fixed wall 1181A. The inclined wall 1181B is inclined with respect to the extension direction of the first arm 520. Specifically, the inclined wall 1181B is inclined so that the closer it is to the first axis A1 in the extension direction of the first arm 520, the closer it is to the center position in the width direction of the first arm 520. The first guide wall 1181C extends from the upper edge of the inclined wall 1181B to the outside of the first arm 520 in the width direction. The second guide wall 1181D connects the fixed wall 1181A, the inclined wall 1181B, and the first guide wall 1181C. The second guide wall 1181D is disposed at the end of the motor blower 1181 on the opposite side to the first axis A1 in the extension direction of the first arm 520. 【0137】 With the above configuration, when the first arm 520 rotates, air is collected by the motor blower 1181, and a flow of air (wind) can be generated from the motor blower 1181 to the first motor 50. Here, the inclined wall 1181B guides the wind to flow toward the first motor 50. The first guide wall 1181C guides the air collected by the motor blower 1181 so that it does not flow upward. The second guide wall 1181D guides the air collected by the motor blower 1181 so that it does not flow in the direction opposite the first motor 50 in the extension direction of the first arm 520. Therefore, wind is sent to the first motor 50 every time the first arm 520 rotates, allowing the first motor 50 to be cooled. 【0138】 Two motor blowers 1181 are provided approximately symmetrically with respect to the center position in the width direction of the first arm 520. This allows the first motor 50 to be cooled by the motor blowers 1181 regardless of whether the first arm 520 rotates clockwise or counterclockwise. 【0139】Note that motor blower 1181 may be formed integrally with main body 521 of first arm 520. In particular, fixed wall 1181A may be omitted, and inclined wall 1181B and second guide wall 1181D may extend directly from upper wall 22 of first arm 520. In this case, the work of fixing motor blower 1181 to first arm 520 can be omitted. Furthermore, by integrally molding motor blower 1181, the strength of first arm 520 can be increased. 【0140】 The reducer blower section 1182 is provided on the lower wall 23 of the first arm 520. The reducer blower section 1182 has a shape that is long in the extension direction of the first arm 520. Two reducer blower sections 1182 are arranged side by side in the width direction. 【0141】 The reducer blower section 1182 includes a fixed wall, an inclined wall 1182B, a first guide wall 1182C, and a second guide wall 1182D. The fixed wall is substantially parallel to the bottom wall 23 and is fixed to the bottom wall 23 by, for example, bolting. The inclined wall 1182B extends downward from the fixed wall. The inclined wall 1182B is inclined with respect to the extension direction of the first arm 520. Specifically, the inclined wall 1182B is inclined so that the closer it is to the first axis A1 in the extension direction of the first arm 520, the closer it is to the center position in the width direction of the first arm 520. The first guide wall 1182C extends from the lower edge of the inclined wall 1182B to the outside of the first arm 520 in the width direction. The second guide wall 1182D connects the fixed wall, the inclined wall 1182B, and the first guide wall 1182C. The second guide wall 1182D is disposed at the end of the reducer blower section 1182 on the opposite side to the first axis A1 in the extension direction of the first arm 520. 【0142】According to the above configuration, when the first arm 520 rotates, air is collected by the reducer blower unit 1182, and an air flow (wind) can be generated from the reducer blower unit 1182 to the first reducer 51. Here, the inclined wall 1182B guides the wind to flow toward the first reducer 51. The first guide wall 1182C guides the air collected by the reducer blower unit 1182 to prevent it from flowing downward. The second guide wall 1182D guides the air collected by the reducer blower unit 1182 to prevent it from flowing in the opposite direction from the first reducer 51 in the extension direction of the first arm 520. Therefore, every time the first arm 520 rotates, wind is sent to the first reducer 51, thereby cooling the first reducer 51. 【0143】 Two reducer blowers 1182 are provided approximately symmetrically with respect to the center position in the width direction of the first arm 520. This allows the reducer blowers 1182 to cool the first reducer 51 regardless of whether the first arm 520 rotates clockwise or counterclockwise. 【0144】 It should be noted that reducer blower section 1182 may be formed integrally with main body section 521 of first arm 520. In particular, the fixed wall may be omitted, and inclined wall 1182B and second guide wall 1182D may extend directly from bottom wall 23 of first arm 520. In this case, it is possible to omit the work of fixing reducer blower section 1182 to first arm 520. Furthermore, by integrally molding reducer blower section 1182, the strength of first arm 520 can be increased. 【0145】As shown in FIG. 37 , the robot 1100 may further include a motor cover 1185 that covers the first motor 50 (see FIG. 36 ). As shown in FIG. 39 , the motor cover 1185 may be attached to the first motor holder 50H. As shown in FIG. 37 , the motor cover 1185 may have a knockout portion 1185A. By applying stress to the knockout portion 1185A and removing it, a through-hole 1185B (see FIGS. 38 and 39 ) can be formed in the portion corresponding to the knockout portion 1185A. The knockout portion 1185A may be formed thinner than other portions of the motor cover 1185, for example. By not providing the through-hole 1185B, it is possible to prevent dust and other particles from being released from the first motor 50 to the outside of the robot 1100. This means that the robot 1100 can be made clean. Furthermore, providing the through-hole 1185B facilitates the release of heat from the first motor 50 to the outside. 【0146】 [Action and effect of embodiment 11] (11-1) The robot 1100 of embodiment 11 further includes a first motor 50 that rotates the first arm 520 relative to the base 10, and a first reducer 51. The first arm 520 has a main body 521 and an air blower 1080 provided on a pair of opposing walls (upper wall 22 and lower wall 23). The air blower 1080 generates an air flow around the first motor 50 and the first reducer 51 by rotating the first arm 520. 【0147】 With this configuration, the first motor 50 and the first reducer 51 can be cooled when the first arm 520 rotates. 【0148】 (11-2) In the eleventh embodiment, the blower 1180 includes inclined walls 1181B and 1182B that are inclined with respect to the extension direction of the first arm 520. 【0149】 With this configuration, airflow is more likely to occur around the first motor 50 and the first reducer 51 . 【0150】 (11-3) In the eleventh embodiment, the blower 1180 may be integrally molded with the main body 521 . 【0151】According to this configuration, the provision of the blower 1180 can increase the strength of the main body 521 . 【0152】 [Embodiment 12] A twelfth embodiment of the present disclosure will be described with reference to Fig. 40. A robot 1200 of embodiment 12 includes a blower 1280 instead of the blower 1180 of embodiment 11. Other configurations, functions, and effects are similar to those of embodiment 11, and therefore, the same reference numerals as those of embodiment 11 are used to designate equivalent members, and detailed description thereof will be omitted. 【0153】 40 , the blower 1280 includes a motor blower 1281 and a reducer blower 1282. The motor blower 1281 is provided on the upper wall 22 of the first arm 520. The motor blower 1281 has a shape that is elongated in the extension direction of the first arm 520. Two motor blowers 1281 are arranged side by side in a direction (hereinafter referred to as the width direction) that is perpendicular to both the extension direction of the first arm 520 and the extension direction of the first axis A1 (the up-down direction). 【0154】 The motor blower 1281 includes a fixed wall 1281A, an inclined wall 1281B, and a first guide wall 1281C. The fixed wall 1281A is substantially parallel to the upper wall 22 and is fixed to the upper wall 22 by, for example, bolting. The inclined wall 1281B extends upward from the fixed wall 1281A. The inclined wall 1281B is inclined with respect to the extension direction of the first arm 520. Specifically, the inclined wall 1281B is inclined so that the closer it is to the first axis A1 in the extension direction of the first arm 520, the further it is from the center position in the width direction of the first arm 520. The first guide wall 1281C extends from the upper edge of the inclined wall 1281B to the outside of the first arm 520 in the width direction. 【0155】With the above configuration, when the first arm 520 rotates, an air flow (wind) can be generated along the inclined wall 1281B from the first motor 50 toward the second axis A2. Here, the first guide wall 1281C guides the air flowing from the first motor 50 toward the second axis A2 so as not to flow upward. Therefore, each time the first arm 520 rotates, the air around the first motor 50 flows toward the second axis A2, thereby cooling the first motor 50. 【0156】 Two motor blowers 1281 are provided approximately symmetrically with respect to the center position in the width direction of first arm 520. This allows first motor 50 to be cooled by motor blowers 1281 regardless of whether first arm 520 rotates clockwise or counterclockwise. 【0157】 Note that motor blower 1281 may be formed integrally with main body 521 of first arm 520. In particular, fixed wall 1281A may be omitted, and inclined wall 1281B may extend directly from upper wall 22 of first arm 520. In this case, the work of fixing motor blower 1281 to first arm 520 can be omitted. Furthermore, by integrally molding motor blower 1281, the strength of first arm 520 can be increased. 【0158】 The reducer blower section 1282 is provided on the lower wall 23 of the first arm 520. The reducer blower section 1282 has a shape that is long in the extension direction of the first arm 520. Two reducer blower sections 1282 are arranged side by side in the width direction. 【0159】The reducer blower section 1282 includes a fixed wall, an inclined wall 1282B, and a first guide wall 1282C. The fixed wall is substantially parallel to the bottom wall 23 and is fixed to the bottom wall 23 by, for example, bolting. The inclined wall 1282B extends downward from the fixed wall. The inclined wall 1282B is inclined with respect to the extension direction of the first arm 520. Specifically, the inclined wall 1282B is inclined so that the closer it is to the first axis A1 in the extension direction of the first arm 520, the further it is from the center position in the width direction of the first arm 520. The first guide wall 1282C extends from the lower edge of the inclined wall 1282B to the outside of the first arm 520 in the width direction. 【0160】 With the above configuration, when the first arm 520 rotates, an air flow (wind) can be generated from the first reducer 51 toward the second axis A2 along the inclined wall 1282B. Here, the first guide wall 1282C guides the air flowing from the first reducer 51 toward the second axis A2 so as not to flow downward. Therefore, every time the first arm 520 rotates, the air around the first reducer 51 flows toward the second axis A2, thereby cooling the first reducer 51. 【0161】 Two reducer blowers 1282 are provided approximately symmetrically with respect to the center position in the width direction of the first arm 520. This allows the reducer blowers 1282 to cool the first reducer 51 regardless of whether the first arm 520 rotates clockwise or counterclockwise. 【0162】 It should be noted that reducer blower section 1282 may be formed integrally with main body section 521 of first arm 520. In particular, the fixed wall may be omitted, and inclined wall 1282B may extend directly from bottom wall 23 of first arm 520. In this case, it is possible to omit the work of fixing reducer blower section 1282 to first arm 520. Furthermore, by integrally molding reducer blower section 1282, the strength of first arm 520 can be increased. 【0163】[Embodiment 13] A thirteenth embodiment of the present disclosure will be described with reference to Figures 41 and 42. A robot 1300 of embodiment 13 includes a fan F1 in addition to the configuration of the robot 600 of embodiment 6. Since the other configurations, functions, and effects are the same as those of embodiment 6, the same reference numerals as those of embodiment 6 are used to designate the same members as those of embodiment 6, and detailed description thereof will be omitted. 【0164】 <Fan> As shown in FIG. 41 , the robot 1300 includes a fan F1 attached to the base 610. The fan F1 is attached to the connecting wall 214 of the base 610 via a hood portion F2. The fan F1 faces the connecting wall 214 in the thickness direction (front-rear direction) of the connecting wall 214. That is, as shown in FIG. 42 , the fan F1 is disposed opposite the through-hole 614H provided in the connecting wall 214 and the opening 216 communicating with the through-hole 614H. Therefore, as the fan F1 rotates, air flows through the through-hole 614H provided in the connecting wall 214 and the opening 216 communicating with the through-hole 614H, thereby cooling the base 610. 【0165】 In addition, a wiring box 56 is attached to the rear of the base 610. The wiring box 56 has an internal space that houses the wiring of the cable C1, and this internal space is defined by the opening 216 of the main body 611. In other words, the internal space of the wiring box 56 does not communicate with the opening 216. This prevents dust from entering the internal space of the wiring box 56 due to the wind generated by the fan F1. 【0166】 [Operations and Effects of Embodiment 13] (13-1) The robot 1300 of embodiment 13 further includes a fan F1 attached to the base 610, the base 610 having the main body 611, and the fan F1 generates air that passes through the through-holes 614H. 【0167】 With this configuration, the base 610 can be cooled. 【0168】(13-2) The robot 1300 of the thirteenth embodiment further includes a wiring box 56 attached to the base 610 , and the wiring box 56 is closed so as not to communicate with the opening 216 . 【0169】 With this configuration, it is possible to prevent dust from entering the wiring box 56 due to the wind generated by the fan F1. 【0170】 [Embodiment 14] Embodiment 14 of the present disclosure will be described with reference to Figures 43 to 46. The robot of embodiment 14 has the same configuration as embodiment 1, except for the configuration of the first arm 1420. Only the configuration of the first arm 1420 will be described below. 【0171】 As shown in FIG. 43 , the first arm 1420 includes two main bodies, namely, a first main body 1421A and a second main body 1421B. The first main body 1421A and the second main body 1421B are assembled in a direction perpendicular to the extension direction of the first arm 1420 (hereinafter referred to as the width direction). The first arm 1420 has a first joint 28 at one end of the first arm 1420 in the extension direction. The first joint 28 has a tubular portion 28A that penetrates the first main body 1421A and the second main body 1421B in a direction perpendicular to both the extension direction and the width direction of the first arm 1420 (the up-down direction). The first arm 1420 has a second joint 29 at the other end of the first arm 1420 in the extension direction. The second joint portion 29 has a shape recessed downward from the upper surfaces of the first main body portion 1421A and the second main body portion 1421B. 【0172】 The first main body portion 1421A includes an upper wall 1422A and a lower wall 1423A that face each other in the vertical direction, a connecting wall 1424A that connects the upper wall 1422A and the lower wall 1423A, and a rib 1425A that connects at least one of the upper wall 1422A and the lower wall 1423A to the connecting wall 1424A. The upper wall 1422A and the lower wall 1423A are an example of a pair of opposing walls. The upper wall 1422A, the lower wall 1423A, and the rib 1425A extend in the thickness direction (width direction) of the connecting wall 1424A. The upper wall 1422A, the lower wall 1423A, and the connecting wall 1424A extend in the extension direction of the first arm 1420. 【0173】 46 , the connecting wall 1424A is connected to the ends of the upper wall 1422A, the lower wall 1423A, and the rib 1425A in the width direction. Therefore, the cross section formed by the upper wall 1422A, the lower wall 1423A, and the connecting wall 1424A has an angular C-shape. The first main body portion 1421A has an opening 1426A that opens in the width direction. The opening 1426A is formed by the upper wall 1422A, the lower wall 1423A, and the rib 1425A. 【0174】 As shown in FIG. 43, the first main body portion 1421A may include an upper wall 1422A, a lower wall 1423A, and end walls 1427A1 and 1427A2 that connect the ends of the connecting wall 1424A in the extension direction of the first arm 1420. 【0175】 The second main body portion 1421B is configured similarly to the first main body portion 1421A. That is, as shown in FIG. 46 , the second main body portion 1421B includes an upper wall 1422B, a lower wall 1423B (an example of a pair of opposing walls), a connecting wall 1424B, and a rib 1425B. The cross section formed by the upper wall 1422B, the lower wall 1423B, and the connecting wall 1424B is angularly C-shaped. The second main body portion 1421B has an opening 1426B that opens in the width direction. As shown in FIG. 43 , the second main body portion 1421B may include end walls 1427B1 and 1427B2. 【0176】 44 and 45, the first arm 1420 is configured by assembling a first main body portion 1421A and a second main body portion 1421B in the width direction, for example, by bolt fastening. In detail, as shown in Fig. 46, the first main body portion 1421A and the second main body portion 1421B are assembled in the width direction so that the connecting wall 1424A and the connecting wall 1424B abut against each other. 【0177】 As shown in Figures 44 and 45, the tubular portion 28A of the first joint portion 28 may be constructed, for example, by combining a half-split tubular portion 28A1 formed on the first main body portion 1421A and a half-split tubular portion 28A2 formed on the second main body portion 1421B. 【0178】The second joint portion 29 (see FIG. 43) may be formed after the first main body portion 1421A and the second main body portion 1421B are assembled together (see FIG. 45). 【0179】 The above-described configuration of first arm 1420 can improve the rigidity of first arm 1420 compared to when the first arm is formed from only one main body portion in which a pair of opposing walls and a connecting wall form an angular C-shaped cross section. Also, molding is easier compared to when the first arm is formed from one main body portion in which a pair of opposing walls and a connecting wall form an I-shaped cross section (a shape obtained by rotating an H-shape by 90 degrees), for example. 【0180】 [Effects and functions of embodiment 14] (14-1) In embodiment 14, two or more main body portions are provided, and the two main body portions (first main body portion 1421A and second main body portion 1421B) are assembled in the thickness direction (width direction) of connecting walls 1424A and 1424B. 【0181】 This configuration allows the strength of the robot to be further increased without compromising ease of molding. 【0182】 [Embodiment 15] Embodiment 15 of the present disclosure will be described with reference to Figures 47 to 50. The robot of embodiment 15 has the same configuration as embodiment 1, except for the configuration of the first arm 1520. Only the configuration of the first arm 1520 will be described below. Below, explanations of actions and effects that overlap with embodiment 14 will be omitted. 【0183】As shown in FIG. 47 , the first arm 1520 has two main bodies, namely, a first main body 1521A and a second main body 1521B. The first main body 1521A and the second main body 1521B are assembled in a direction perpendicular to the extension direction of the first arm 1520 (hereinafter referred to as the width direction). The first arm 1520 has a first joint 28 at one end of the first arm 1520 in the extension direction. The first joint 28 has a tubular portion 28A that penetrates the first main body 1521A and the second main body 1521B in a direction perpendicular to both the extension direction and the width direction of the first arm 1520 (the up-down direction). The first arm 1520 has a second joint 29 at the other end of the first arm 1520 in the extension direction. The second joint portion 29 has a shape recessed downward from the upper surfaces of the first main body portion 1521A and the second main body portion 1521B. 【0184】 50 , the first main body portion 1521A includes an upper wall 1522A and a lower wall 1523A that face each other in the vertical direction, a connecting wall 1524A that connects the upper wall 1522A and the lower wall 1523A, and a rib 1525A that connects at least one of the upper wall 1522A and the lower wall 1523A to the connecting wall 1524A. The upper wall 1522A and the lower wall 1523A are an example of a pair of opposing walls. The upper wall 1522A, the lower wall 1523A, and the rib 1525A extend in the thickness direction (width direction) of the connecting wall 1524A. The upper wall 1522A, the lower wall 1523A, and the connecting wall 1524A extend in the extension direction of the first arm 1520. 【0185】 The connecting wall 1524A is connected to the ends of the upper wall 1522A, the lower wall 1523A, and the rib 1525A in the width direction. Therefore, the cross section formed by the upper wall 1522A, the lower wall 1523A, and the connecting wall 1524A has an angular C-shape. The first main body portion 1521A has an opening 1526A that opens in the width direction. The opening 1526A is formed by the upper wall 1522A, the lower wall 1523A, and the rib 1525A. 【0186】 As shown in FIG. 47, the first main body portion 1521A may include an upper wall 1522A, a lower wall 1523A, and end walls 1527A1 and 1527A2 that connect the ends of the connecting wall 1524A in the extension direction of the first arm 1520. 【0187】 The second main body portion 1521B is configured similarly to the first main body portion 1521A. That is, as shown in FIG. 50 , the second main body portion 1521B includes an upper wall 1522B, a lower wall 1523B (an example of a pair of opposing walls), a connecting wall 1524B, and a rib 1525B. The cross section formed by the upper wall 1522B, the lower wall 1523B, and the connecting wall 1524B is angularly C-shaped. The second main body portion 1521B has an opening 1526B that opens in the width direction. As shown in FIG. 47 , the second main body portion 1521B may include end walls 1527B1 and 1527B2. 【0188】 48 and 49, first arm 1520 is configured by assembling first body portion 1521A and second body portion 1521B in the width direction, for example, by bolt fastening. In detail, as shown in Fig. 50, first body portion 1521A and second body portion 1521B are assembled in the width direction so that opening 1526A and opening 1526B are in communication with each other. 【0189】 The first joint portion 28 and the second joint portion 29 (see FIG. 47) may be formed after the first main body portion 1521A and the second main body portion 1521B are assembled (see FIG. 49). 【0190】 According to the configuration of first arm 1520 as described above, openings 1526A and 1526B are not open to the outside, so dust and the like are less likely to accumulate in first arm 1520. Furthermore, the cross-sectional shape of first arm 1520 can be made box-shaped without impairing formability, and the strength of first arm 1520 can be increased. 【0191】 [Embodiment 16] Embodiment 16 of the present disclosure will be described with reference to Figures 51 to 54. The robot of embodiment 16 has the same configuration as embodiment 1, except for the configuration of the first arm 1620. Only the configuration of the first arm 1620 will be described below. The effects of embodiment 16 are substantially the same as those of embodiment 15, and therefore will not be described again. 【0192】As shown in FIG. 51 , the first arm 1620 includes two main bodies, namely, a first main body 1621A and a second main body 1621B. The first main body 1621A and the second main body 1621B are assembled in a direction perpendicular to the extension direction of the first arm 1620 (the vertical direction). The first arm 1620 includes a first joint 28 at one end of the first arm 1620 in the extension direction. The first joint 28 includes a tubular portion 28A that penetrates the first main body 1621A and the second main body 1621B in the vertical direction. The first arm 1620 includes a second joint 29 at the other end of the first arm 1620 in the extension direction. The second joint 29 has a shape that is recessed downward from the top surface of the first main body 1621A. 【0193】 As shown in FIG. 54 , the first main body 1621A includes a right wall 1622A and a left wall 1623A that face each other in a direction (hereinafter referred to as the width direction) perpendicular to both the extension direction and the up-down direction of the first arm 1620, a connecting wall 1624A connecting the right wall 1622A and the left wall 1623A, and a rib 1625A connected to at least one of the right wall 1622A and the left wall 1623A and the connecting wall 1624A. The right wall 1622A and the left wall 1623A are an example of a pair of opposing walls. The right wall 1622A, the left wall 1623A, and the rib 1625A extend in the thickness direction (up-down direction) of the connecting wall 1624A. The right wall 1622A, the left wall 1623A, and the connecting wall 1624A extend in the extension direction of the first arm 1620. 【0194】 The connecting wall 1624A is connected to the ends (upper ends) of the right wall 1622A, the left wall 1623A, and the rib 1625A in the vertical direction. Therefore, the cross section formed by the right wall 1622A, the left wall 1623A, and the connecting wall 1624A has an angular C-shape. The first main body portion 1621A has an opening 1626A that opens in the vertical direction. The opening 1626A is formed by the right wall 1622A, the left wall 1623A, and the rib 1625A. 【0195】 As shown in FIG. 51, the first main body portion 1621A may include a right wall 1622A, a left wall 1623A, and end walls 1627A1 and 1627A2 that connect the ends of the connecting wall 1624A in the extension direction of the first arm 1620. 【0196】 The second main body portion 1621B is configured similarly to the first main body portion 1621A. That is, as shown in FIG. 54 , the second main body portion 1621B includes a right wall 1622B and a left wall 1623B (an example of a pair of opposing walls), a connecting wall 1624B, and a rib 1625B. The cross section formed by the right wall 1622B, the left wall 1623B, and the connecting wall 1624B is angularly C-shaped. The second main body portion 1621B has an opening 1626B that opens in the vertical direction. As shown in FIG. 51 , the second main body portion 1621B may include end walls 1627B1 and 1627B2. 【0197】 52 and 53, first arm 1620 is configured by assembling first body portion 1621A and second body portion 1621B in the vertical direction, for example, by bolting. In detail, as shown in Fig. 54, first body portion 1621A and second body portion 1621B are assembled in the vertical direction so that opening 1626A and opening 1626B are in communication with each other. 【0198】 As shown in FIG. 52, the tubular portion 28A of the first joint portion 28 may be formed, for example, by combining a first tubular portion 28A3 formed on the first main body portion 1621A and a second tubular portion 28A4 formed on the second main body portion 1621B. 【0199】 The second joint portion 29 (see FIG. 51) may be formed after the first main body portion 1621A and the second main body portion 1621B are assembled together (see FIG. 53). 【0200】 Other Embodiments (1) The robot according to the present disclosure does not have to be a SCARA robot, but may be, for example, a Cartesian robot or a vertical articulated robot. 【0201】 (2) In the robot of the present disclosure, the pair of opposing walls does not necessarily have to be perpendicular to the connecting wall. 【0202】 (3) In the above embodiment, bolt fastening is used as an example of a method for fastening members. However, methods other than bolt fastening may be used to fasten members. 【0203】100: Robot 10: Base 10J: Joint section 20: First arm (arm) 21: Main body section 22: Upper wall (opposing wall) 23: Lower wall (opposing wall) 24: Connecting wall 25: Rib 26: Opening 27A, 27B: End wall 28: First joint section 29: Second joint section 30: Second arm (arm) 31: Main body section 32: Upper wall (opposing wall) 33: Lower wall (opposing wall) 34: Connecting wall 35: Rib 36: Opening 37A, 37B: End wall 38: First joint section 39: Second joint section 40: Actuating shaft 50: First motor (motor) 51: First reducer (reduction gear) 52: Second motor (motor) 53: Second reducer 54: Third motor (motor) 55: Fourth motor (motor) A1: First axis A2: Second axis C1: Cable 200: Robot 210: Base 211: Main body 212: Right wall (opposing wall) 213: Left wall (opposing wall) 214: Main body 214: Connecting wall 215: Rib 216: Opening 217: End wall 218: Joint 56: Wiring box 56A: Internal space 300: Robot 310: Base 311: Main body 312: Front wall (opposing wall) 313: Rear wall (opposing wall) 314: Connecting wall 315: Rib 316: Opening 317: End wall 318: Joint 420: First arm (arm) 421: Main body 421A: First part 422A: Upper wall (opposing wall) 423A: Lower wall (opposing wall) 424A: Connecting wall 425A: Rib 426A: Opening 427A: End wall 421B: Second portion 422B: Upper wall (opposing wall) 423B: Lower wall (opposing wall) 424B: Connecting wall 425B: Rib 426B: Opening 427B: End wall 421C: Tapered portion 422C: Upper wall (opposing wall) 423C: Lower wall (opposing wall) 424C: Connecting wall 424C1,424C2: Outer rib 425C: Rib 426C: Opening 500: Robot 520: First arm (arm) 521: Main body part 524H: Through hole 530: Second arm (arm) 531: Main body part 534H: Through hole 600: Robot 610: Base 611: Main body part 614H: Through hole 700: Robot 710: Base 711: Main body part 714H: Through hole 800: Robot 860: Plate part 900: Robot 960: Plate part 961: Knockout part 962: Communication hole 1000: Robot 38A: Cylinder part 39A: Cylinder part 52A: Output part 53A: Input part 53B: Output part 53C: Fixing part 54A: Output part 55A: Output part 52H: Second motor holder (motor holder) 54H: Third motor holder (motor holder) 55H: Fourth motor holder (motor holder) 1041: Ball screw nut 1041H: Ball screw nut holder 1042: Spline nut 1043: Fourth reducer 1043A: Input section 1043B: Fixing section 1043C: Output section 1044A, 1044B: Connecting member 1070: Cover 1071: First cover wall 1071A: Through hole 1071B: Bushing 1072: Cover peripheral wall 1075: Wiring section 1077: Motor cover 1077A: Knockout section 1077B: Through hole B1, B2: Belt P1, P2, P3,P4: Pulley 1100: Robot 28A: Cylinder 50A: Output section 51A: Fixed section 51B: Input section 51C: Output section 50H: First motor holder 1180: Blower section 1181: Blower section for motor 1181A: Fixed wall 1181B: Inclined wall 1181C: First guide wall 1181D: Second guide wall 1182: Blower section for reducer 1182B: Inclined wall 1182C: First guide wall 1182D: Second guide wall 1185: Motor cover 1185A: Knockout section 1185B: Through hole 1200: Robot 1280: Blower section 1281: Blower section for motor 1281A: Fixed wall 1281B: Inclined wall 1281C: First guide wall 1282: Reducer blower section 1282B: Inclined wall 1282C: First guide wall 1300: Robot F1: Fan F2: Hood section 1420: First arm (arm) 1421A: First main body section (main body section) 1422A: Upper wall (opposing wall) 1423A: Lower wall (opposing wall) 1424A: Connecting wall 1425A: Rib 1426A: Opening 1427A1, 1427A2: End wall 28A1: Half cylinder section 1421B: Second main body section (main body section) 1422B: Upper wall (opposing wall) 1423B: Lower wall (opposing wall) 1424B: Connecting wall 1425B: Rib 1426B: Opening 1427B1, 1427B2: End wall 28A2: Half-cylinder portion 1520: First arm (arm) 1521A: First main body portion (main body portion) 1522A: Upper wall (opposing wall) 1523A: Lower wall (opposing wall) 1524A: Connecting wall 1525A: Rib 1526A: Opening 1527A1, 1527A2: End wall 1521B: Second main body portion (main body portion) 1522B: Upper wall (opposing wall) 1523B: Lower wall (opposing wall) 1524B: Connecting wall 1525B: Rib 1526B: Opening 1527B1, 1527B2: End wall 1600: First arm (arm) 1621A: First main body portion (main body portion) 1622A: Right wall (opposing wall) 1623A: Left wall (opposing wall) 1624A: connecting wall 1625A: rib 1626A: opening 1627A1,1627A2: End wall 28A3: First tube 1621B: Second body (body) 1622B: Right wall (facing wall) 1623B: Left wall (facing wall) 1624B: Connecting wall 1625B: Lift 1626B: Opening 1627B1, 1627B2: End wall 28A4: Second tube,

Claims

[Claim 1] Bass and, It comprises an arm that is movably supported with respect to the base, The base has a main body comprising a pair of opposing walls facing each other, a connecting wall connecting the pair of opposing walls, and a rib connected to at least one of the pair of opposing walls and the connecting wall. The pair of opposing walls and the ribs extend in the thickness direction of the connecting wall, The robot has an opening formed in the main body that opens in the thickness direction of the connecting wall. [Claim 2] The robot according to claim 1, wherein the connecting wall is connected to the pair of opposing walls and the ends of the ribs in the thickness direction of the connecting wall. [Claim 3] The robot according to claim 1, wherein the connecting wall is connected to the pair of opposing walls and the ribs in the thickness direction of the connecting wall near the center. [Claim 4] (delete) [Claim 5] The robot according to any one of claims 1 to 3, wherein the main body portion has a through hole that penetrates the connecting wall. [Claim 6] The robot according to any one of claims 1 to 3, further comprising a plate portion attached to the main body portion so as to close the opening. [Claim 7] The main body further comprises a resin plate portion attached to the main body portion so as to close the aforementioned opening, The robot according to any one of claims 1 to 3, wherein the plate portion is provided with a knockout portion capable of forming a communication hole that communicates with the opening. [Claim 8] (delete) [Claim 9] (delete) [Claim 10] (delete) [Claim 11] (delete) [Claim 12] (delete) [Claim 13] (delete) [Claim 14] The base further comprises a fan that can be attached to the base, The robot according to claim 5, wherein the fan generates airflow that passes through the through-hole. [Claim 15] The base further comprises a wiring box that is attached to the base, The robot according to claim 14, wherein the wiring box is closed so as not to communicate with the opening. [Claim 16] The aforementioned main body is provided in two or more parts. The robot according to claim 2, wherein the two main body parts are assembled in the thickness direction of the connecting wall. [Claim 17] Bass and, It comprises an arm that is movably supported with respect to the base, The arm has a main body comprising a pair of opposing walls facing each other, a connecting wall connecting the pair of opposing walls, and a rib connected to at least one of the pair of opposing walls and the connecting wall. The pair of opposing walls and the ribs extend in the thickness direction of the connecting wall, The main body portion has an opening that opens in the thickness direction of the connecting wall, The aforementioned arm is rotatable around the pivot axis, A robot in which the thickness direction of the connecting wall is perpendicular to the extension direction of the pivot axis. [Claim 18] The robot according to claim 17, wherein the connecting wall is connected to the pair of opposing walls and the ends of the ribs in the thickness direction of the connecting wall. [Claim 19] The robot according to claim 17, wherein the connecting wall is connected to the pair of opposing walls and the ribs in the thickness direction of the connecting wall near the center. [Claim 20] The connecting wall and the pair of opposing walls extend in a first direction which is the extension direction of the arm. The robot according to any one of claims 17 to 19, wherein the main body portion has a tapered portion whose dimension in the direction perpendicular to the first direction decreases as it moves toward one side of the first direction. [Claim 21] The robot according to any one of claims 17 to 19, wherein the main body portion has a through hole that penetrates the connecting wall. [Claim 22] The robot according to any one of claims 17 to 19, further comprising a plate portion attached to the main body portion so as to close the opening. [Claim 23] The main body further comprises a resin plate portion attached to the main body portion so as to close the aforementioned opening, The robot according to any one of claims 17 to 19, wherein the plate portion is provided with a knockout portion capable of forming a communication hole that communicates with the opening. [Claim 24] It further includes a motor and a motor holder, The robot according to any one of claims 17 to 19, wherein the motor is fixed to one of the pair of opposing walls of the arm via the motor holder. [Claim 25] It further includes a ball screw nut and a ball screw nut holder, The robot according to claim 24, wherein the ball screw nut is fixed to one of the pair of opposing walls of the arm via the ball screw nut holder. [Claim 26] The motor holder and the ball screw nut holder are further provided with a cover that covers at least a portion of them. The cover comprises a first cover wall parallel to the pair of opposing walls, The robot according to claim 25, wherein the motor holder and the ball screw nut holder are fixed to the first cover wall. [Claim 27] The system further comprises a motor for rotating the arm relative to the base, and a reduction gear. The arm has a blower section provided on the pair of opposing walls, The robot according to any one of claims 17 to 19, wherein the blowing unit generates an airflow around the motor and the reduction gear by the rotation of the arm. [Claim 28] The robot according to claim 27, wherein the air blowing section includes an inclined wall that is inclined with respect to the extension direction of the arm. [Claim 29] The robot according to claim 27, wherein the blowing unit is integrally molded with the main body. [Claim 30] The aforementioned main body is provided in two or more parts. The robot according to claim 18, wherein the two main body parts are assembled in the thickness direction of the connecting wall.