Robot

Abstract

To provide a robot which is effective for reduction of the weight and improvement of rigidity.SOLUTION: A robot according to one aspect of the disclosure includes a link and an actuator which causes the link to rotate around a rotation axis. The link has: a connection part connected to the actuator; a link base part which extends from the connection part, intersecting with the rotation axis; and a protruding part which protrudes from the link base part in a position spaced away from the connection part and an end of the link base part between the connection part and the end of the link base part.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to robots. [Background technology]

[0002] Patent Document 1 discloses a robot including a base, a first structure connected to the base rotatably around a first axis, a second structure connected to the first structure rotatably around a second axis perpendicular to the first axis, and a third structure connected to the second structure rotatably around a third axis parallel to the second axis. The second structure has a main structure, an auxiliary structure, and a connector that connects the main structure to the auxiliary structure. The first structure and the third structure are each sandwiched between the main structure and the auxiliary structure. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-161868 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a robot that is effective in achieving both weight reduction and increased rigidity. [Means for solving the problem]

[0005] A robot according to one aspect of the present disclosure comprises a link and an actuator that rotates the link around a rotation axis, the link having a connection portion connected to the actuator, a link base extending from the connection portion intersecting the rotation axis, and a protrusion protruding from the link base between the connection portion and an end of the link base at a position spaced apart from the connection portion and the end of the link base. Effect of the Invention

[0006] According to the present disclosure, a robot is provided that is effective in achieving both weight reduction and increased rigidity. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view showing an example of a robot. [Diagram 2] FIG. 2 is a perspective view showing an example of a robot. [Diagram 3] FIG. 3 is a cross-sectional view showing an example of the inside of a robot. [Figure 4] FIG. 4 is a perspective view showing an example of a drive link. [Diagram 5] FIG. 5 is a side view showing an example of a drive link. [Figure 6] FIG. 6 is a side view illustrating an example of a driving link. [Figure 7] FIG. 7 is a cross-sectional view that illustrates an example of a seal provided between links. [Figure 8] FIG. 8 is a perspective view illustrating a portion of the robot with the cover removed. [Figure 9] FIG. 9 is a cross-sectional view showing an example of the inside of a rotating link. [Figure 10] FIG. 10 is a perspective view illustrating a portion of the robot with the cover removed. [Figure 11] FIG. 11 is a cross-sectional view that illustrates an example of a bearing provided between links. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment will be described with reference to the drawings. In the description, the same elements or elements having the same functions are denoted by the same reference numerals, and duplicated description will be omitted.

[0009] 1 and 2 show a robot according to an embodiment. The robot 1 shown in FIG. 1 is a vertical articulated robot. The robot 1 automatically performs various tasks on work objects. The robot 1 is, for example, an industrial robot, and in one example, in a product production line, automatically performs various transport, processing, assembly, and the like on parts or assemblies. The use of the robot 1 is not limited to industrial use. Below, an overview of the structure of the robot 1 will be first described, and then some of the members equipped in the robot 1 will be described in detail.

[0010] [Outline of robot structure] The robot 1 includes a base 2 and an articulated arm 4. The base 2 is a portion that supports the articulated arm 4. The articulated arm 4 is rotatably attached to the base 2, and has a serial link type structure.

[0011] The base 2 has a base link 10 and a rotating link 20. The base link 10 is also called a base or a base, and is fixed to an installation surface. The installation surface may be a surface that forms a work area where work is performed by the robot 1, for example, the bottom surface of the work area. The base link 10 may be fixed to a horizontal installation surface. The base link 10 may be fixed to an installation surface on a moving body such as an AGV (Automatic Guided Vehicle).

[0012] The rotating link 20 is connected to the base link 10 so as to rotate (pivot) around a rotation axis Ax1 (pivot axis). The rotating link 20 is attached to the base link 10 so as to be located above the base link 10, for example. The rotation axis Ax1 may be set to pass through the base link 10 and the rotating link 20. The rotating link 20 may be provided on the base link 10 so as to rotate around a vertical rotation axis Ax1.

[0013] In the present disclosure, when describing the structure of the robot 1, "up" and "down" are used to indicate the positional relationship. This "up" and "down" mean "up" and "down" in a state in which the rotation axis Ax1 is vertical and the revolving link 20 is located above the base link 10, but the base 2 does not necessarily have to be disposed in this manner. For example, the base 2 may be disposed so that the revolving link 20 is located below the base link 10, or so that the revolving link 20 is located to the side of the base link 10. The base link 10 may be fixed to a wall surface of the work area, or may be fixed to a ceiling surface of the work area.

[0014] The articulated arm 4 has, for example, an arm link 30, an arm link 60, an arm link 70, and a tool attachment portion 80. Each of the arm link 30, the arm link 60, and the arm link 70 is also simply referred to as an arm.

[0015] The arm link 30 is connected to the revolving link 20 so as to rotate around a rotation axis Ax2. The rotation axis Ax2 intersects with the rotation axis Ax1, for example. In the present disclosure, "intersection" also includes a torsional relationship such as a so-called three-dimensional intersection. The arm link 30 may extend away from the rotation axis Ax2. The arm link 30 (second link) may be aligned with the revolving link 20 (first link) along the rotation axis Ax2. The rotation axis Ax2 may be perpendicular to the rotation axis Ax1. The rotation axis Ax2 may be set to pass through the base end of the arm link 30 and the revolving link 20.

[0016] The arm link 60 is connected to the arm link 30 so as to rotate around a rotation axis Ax3 (second rotation axis) parallel to the rotation axis Ax2. The arm link 60 is connected, for example, to the tip (end) of the arm link 30. The arm link 60 may extend away from the rotation axis Ax3. The arm link 60 (third link) may be aligned with the arm link 30 along the rotation axis Ax3. The rotation axis Ax3 may be set to pass through the tip of the arm link 30 and the base end of the arm link 60.

[0017] The arm link 60 includes an arm base 62 and a pivot arm 64. The arm base 62 (third link) is a link connected to the tip of the arm link 30 so as to rotate around a rotation axis Ax3. The arm base 62 may extend away from the rotation axis Ax3. The arm base 62 may be aligned with the arm link 30 along the rotation axis Ax3. The pivot arm 64 (fourth link) is a link connected to the arm base 62 so as to rotate around a rotation axis Ax4 intersecting the rotation axis Ax3. The pivot arm 64 may extend from the arm base 62 along the direction in which the arm base 62 extends. The rotation axis Ax4 may be perpendicular to the rotation axis Ax3. The rotation axis Ax4 may be set to pass through the arm base 62 and the pivot arm 64.

[0018] The arm link 70 is connected to the arm link 60 so as to rotate about a rotation axis Ax5 intersecting the rotation axis Ax4. The arm link 70 is attached, for example, to the tip of the rotating arm 64 of the arm link 60. The rotation axis Ax5 may be perpendicular to the rotation axis Ax4. The rotation axis Ax5 may be set to pass through the tip of the rotating arm 64 and the arm link 70.

[0019] The tool attachment portion 80 is connected to the arm link 70 so as to rotate about a rotation axis Ax6 intersecting the rotation axis Ax5. The rotation axis Ax6 may be perpendicular to the rotation axis Ax5. The rotation axis Ax6 may be set to pass through the arm link 70 and the tool attachment portion 80. A work tool is attached to the tool attachment portion 80. Specific examples of the work tool include a suction nozzle that sucks up a workpiece, a hand that grips a workpiece, a welding torch, a screw tightening tool, and a polishing tool.

[0020] The robot 1 includes an actuator 110, an actuator 120, an actuator 130, an actuator 140, an actuator 150, and an actuator 160. In Fig. 1, each actuator is simplified and shown typically by a broken line, and in Fig. 2, the illustration of each actuator is omitted. Each actuator may include a motor and a reducer.

[0021] The actuator 110 rotates the pivot link 20 about the rotation axis Ax1 relative to the base link 10. The actuator 120 rotates the arm link 30 about the rotation axis Ax2 relative to the pivot link 20. The actuator 130 (second actuator) rotates the arm base 62 of the arm link 60 about the rotation axis Ax3 relative to the arm link 30.

[0022] The actuator 140 rotates the pivot arm 64 of the arm link 60 about the rotation axis Ax4 relative to the arm base 62. The actuator 150 rotates the arm link 70 about the rotation axis Ax5 relative to the pivot arm 64 of the arm link 60. The actuator 160 rotates the tool attachment portion 80 about the rotation axis Ax6 relative to the arm link 70.

[0023] [Arm Link] Next, a detailed description will be given of the structure of the arm link 30 and some of the members located inside or around the arm link 30. The arm link 30 may include two sub-links. As shown in Fig. 1 or 2, the arm link 30 may have a driving link 40 (link) and an auxiliary link 50 as the two sub-links.

[0024] The driving link 40 (first sub-link) and the auxiliary link 50 (second sub-link) may sandwich the actuator 120 along the rotation axis Ax2. When observed along the rotation axis Ax2, the driving link 40, the actuator 120, and the auxiliary link 50 may be arranged in this order. The driving link 40 and the auxiliary link 50 may sandwich the actuator 130 along the rotation axis Ax3. When observed along the rotation axis Ax3, the driving link 40, the actuator 130, and the auxiliary link 50 may be arranged in this order.

[0025] The auxiliary link 50 may be made of a material (second material) having a smaller rigidity and specific gravity than the material (first material) forming the driving link 40. The rigidity of the material forming the auxiliary link 50 may be smaller than the rigidity of the material forming the driving link 40, and the specific gravity of the material forming the auxiliary link 50 may be smaller than the specific gravity of the material forming the driving link 40. For example, when the material forming the driving link 40 is a material containing iron, the material forming the auxiliary link 50 is a material containing aluminum. The material forming the driving link 40 and the material forming the auxiliary link 50 may have different thermal expansion coefficients (linear expansion coefficients).

[0026] <Driven link> The driving link 40 is a link driven by the actuator 120. For example, a driving force from the actuator 120 is directly transmitted to the driving link 40. The driving link 40 may be connected to the pivot link 20. The actuator 120 rotates the driving link 40 around the rotation axis Ax2 relative to the pivot link 20. FIG. 3 shows a cross section taken along line III-III in FIG. 2. The actuator 120 is connected to any point of the driving link 40. The driving link 40 (second link) may be aligned with the pivot link 20 (first link) along the rotation axis Ax2. The driving link 40 may extend away from the rotation axis Ax2.

[0027] The actuator 120 may be housed in the pivot link 20. The pivot link 20 may have an internal space S2 and an opening 24 (see also FIG. 8 ). The internal space S2 is a space that houses the actuator 120. At least a portion of the actuator 120 may be housed in the internal space S2. The pivot link 20 has a housing 21. The housing 21 is constituted by walls that form the internal space S2. The opening 24 is an opening formed in the housing 21.

[0028] In FIG. 3, the motor of the actuator 120 is indicated by "122", and the reducer of the actuator 120 is indicated by "124". The motor 122 includes a motor body 122a and an output shaft 122b. The motor 122 rotates the driving link 40 around the rotation axis Ax2 relative to the rotating link 20. The motor 122 may be accommodated in the internal space S2 in the rotating link 20. The motor 122 may be arranged such that the motor body 122a is accommodated in the internal space S2 in the rotating link 20. The motor 122 may be installed such that the output shaft 122b is horizontal. The output shaft 122b of the motor 122 is connected to the reducer 124. In one example, the output shaft of the reducer 124 of the actuator 120 is connected to the driving link 40.

[0029] An actuator 130 for driving the arm base 62 of the arm link 60 rotates the arm base 62 relative to the driving link 40 of the arm link 30 around the rotation axis Ax3. The actuator 130 is connected to any location of the driving link 40. For example, a driving force from the actuator 130 is applied to the driving link 40, causing the arm base 62 to rotate relative to the driving link 40. The arm base 62 (second link) of the arm link 60 may be connected to an end of the driving link 40. The arm base 62 (second link) of the arm link 60 may be aligned with the driving link 40.

[0030] The actuator 130 may be housed in the arm base 62 of the arm link 60. The arm base 62 of the arm link 60 may have an internal space S6 and an opening 66 (see also FIG. 10 ). The internal space S6 is a space that houses the actuator 130. At least a portion of the actuator 130 may be housed in the internal space S6. The arm base 62 of the arm link 60 has a housing 65. The housing 65 is constituted by walls that form the internal space S6. The opening 66 is an opening formed in the housing 65.

[0031] In FIG. 3, the motor of the actuator 130 is indicated by "132", and the reducer of the actuator 130 is indicated by "134". The motor 132 includes a motor body 132a and an output shaft 132b. The motor 132 (second motor) rotates the arm base 62 around the rotation axis Ax3 relative to the driving link 40. The motor 132 may be housed in the arm base 62. The motor 132 may be arranged such that the motor body 132a is housed in the internal space S6 in the arm base 62. The motor 132 may be installed such that the output shaft 132b is horizontal. The output shaft 132b of the motor 132 is connected to the reducer 134. In one example, the output shaft of the reducer 134 of the actuator 130 is connected to the driving link 40.

[0032] Fig. 4 shows a perspective view of the drive link 40, and Fig. 5 shows a side view of the drive link 40 seen from a direction along the rotation axis Ax2. Fig. 6 shows a schematic diagram of the side of the drive link 40 seen from a direction perpendicular to a plane including the rotation axis Ax2 and the rotation axis Ax3. As shown in Fig. 4 etc., the drive link 40 is formed to extend between the rotation axis Ax2 and the rotation axis Ax3. The direction in which the entire drive link 40 extends may be along a line segment that connects the rotation axis Ax2 and the rotation axis Ax3 at the shortest distance.

[0033] The driving link 40 may be attached to the actuator 120. The driving link 40 may be attached to the actuator 130. The driving link 40 includes, for example, a connection portion 42, a connection portion 46, a link base portion 44, and a reinforcing portion 48. When the driving link 40 is observed from the rotation axis Ax2 toward the rotation axis Ax3, the connection portion 42, the link base portion 44, and the connection portion 46 are arranged in this order.

[0034] The connection part 42 is a portion that is connected to the actuator 120. For example, an output shaft of the reducer 124 of the actuator 120 is connected to the connection part 42. The connection part 42 may include a connection base part 42a and a surrounding wall 42b. The connection base part 42a and the surrounding wall 42b form a space for accommodating at least a part of the actuator 120 (for example, the reducer 124 of the actuator 120).

[0035] The connection base 42a is a portion that is connected to the actuator 120. For example, an output shaft of the reducer 124 of the actuator 120 is connected to the connection base 42a. The connection base 42a may be formed so as to extend along a plane that intersects with the rotation axis Ax2. The thickness of the connection base 42a may not be constant, and at least a part of each of a pair of main surfaces of the connection base 42a may not be flat. The shape of the connection base 42a may be circular when viewed from the rotation axis Ax2.

[0036] The surrounding wall 42b is a portion that protrudes from the connection base 42a so as to surround at least a portion of the actuator 120. The surrounding wall 42b is formed, for example, in an annular shape so as to surround at least a portion of the reducer 124. The surrounding wall 42b protrudes in a predetermined direction from the outer edge portion (the outer edge and a portion in the vicinity thereof) of the connection base 42a. The surrounding wall 42b protrudes, for example, in the axial direction in which the rotation axis Ax2 extends.

[0037] The connection portion 46 (second connection portion) is a portion that is connected to the actuator 130 (second actuator). For example, an output shaft of the reducer 134 of the actuator 130 is connected to the connection portion 46. The connection portion 46 may include a connection base 46a (second connection base) and a surrounding wall 46b (second surrounding wall). The connection base 46a and the surrounding wall 46b form a space for accommodating at least a portion of the actuator 130 (for example, the reducer 134 of the actuator 130).

[0038] The connection base 46a is a portion connected to the actuator 130. For example, an output shaft of the reducer 134 of the actuator 130 is connected to the connection base 46a. The connection base 46a may be formed to extend along a plane intersecting the rotation axis Ax2. The thickness of at least a part of the connection base 46a may not be constant, and at least a part of each of a pair of main surfaces of the connection base 46a may not be flat. The shape of the connection base 46a may be circular when viewed from the rotation axis Ax3.

[0039] The surrounding wall 46b is a portion that protrudes from the connection base 46a so as to surround at least a portion of the actuator 130. The surrounding wall 46b is formed, for example, in an annular shape so as to surround at least a portion of the reducer 134. The surrounding wall 46b protrudes in a predetermined direction from the outer edge portion (the outer edge and a portion in the vicinity thereof) of the connection base 46a. The surrounding wall 46b protrudes, for example, in the axial direction in which the rotation axis Ax3 extends.

[0040] The link base 44 is a portion that extends from the connection portion 42 and intersects with the rotation axis Ax2. The link base 44 is connected to the connection portion 46, and also intersects with the rotation axis Ax3. The link base 44 may be formed so as to extend along a plane that intersects with the rotation axis Ax2. The thickness of at least a portion of the link base 44 does not have to be constant, and at least a portion of each of a pair of main surfaces of the link base 44 does not have to be flat.

[0041] When viewed in the axial direction of the rotation axis Ax2 and the rotation axis Ax3, the link base 44 is formed to extend along an imaginary line segment connecting the rotation axis Ax2 and the rotation axis Ax3. The connection base 42a of the connection part 42 is connected to the link base 44, and the connection base 46a of the connection part 46 is connected to the link base 44. The connection part 42 (connection base 42a and the surrounding wall 42b), the link base 44, and the connection part 46 (connection base 46a and the surrounding wall 46b) may be formed integrally.

[0042] Here, when viewed from a direction parallel to the rotation axis Ax2 and the rotation axis Ax3, a direction perpendicular to a virtual line passing through the rotation axis Ax2 and the rotation axis Ax3 is defined as the "width direction" of the drive link 40. The link base 44 is formed so that its size in the width direction is smaller in a central portion between the rotation axis Ax2 and the rotation axis Ax3. From the central portion between the rotation axis Ax2 and the rotation axis Ax3, the size of the link base 44 in the width direction increases as it approaches the connection part 42, and the size of the link base 44 in the width direction increases as it approaches the connection part 46.

[0043] The reinforcing portion 48 is formed to increase the rigidity while reducing the weight of the driving link 40. The reinforcing portion 48 may be formed so as to protrude from the link base 44 between the connecting portion 42 and an end portion (an end portion closer to the rotation axis Ax3) of the link base 44. The reinforcing portion 48 is formed integrally with the link base 44, for example, between the connecting portion 42 and the connecting portion 46, so as to protrude from the link base 44. The reinforcing portion 48 may protrude in the same direction as the surrounding wall 42b and the surrounding wall 46b, and may be connected to the surrounding wall 42b and the surrounding wall 46b.

[0044] The reinforcing portion 48 includes a protruding portion 48a. The protruding portion 48a is a portion that protrudes from the link base 44 at a position away from each of the connecting portion 42 and the end portion (the end portion closer to the rotation axis Ax3) of the link base 44. The protruding portion 48a may be formed in an annular shape around an axis Ax0 that intersects with the link base 44. The axis Ax0 is an imaginary axis that intersects with the direction in which the link base 44 extends and passes through the link base 44. When viewed from a direction parallel to the rotation axis Ax2 and the rotation axis Ax3, the protruding portion 48a surrounds the axis Ax0. The axis Ax0 may pass through the center of gravity of a region defined by an opening edge at the inner edge of the annular protruding portion 48a. The length of the line segment connecting the rotation axis Ax2 and the axis Ax0 at the shortest distance may be approximately 0.8 to 1.2 times the length of the line segment connecting the rotation axis Ax3 and the axis Ax0 at the shortest distance.

[0045] At least a part of the protrusion 48a may be formed so that the size in the width direction decreases as the protrusion 48a moves away from the link base 44. Instead of or in addition to the width direction, at least a part of the protrusion 48a may be formed so that the size in the direction in which the link base 44 extends decreases as the protrusion 48a moves away from the link base 44. When viewed from a direction parallel to the rotation axis Ax2 and the rotation axis Ax3, an end face of the protrusion 48a in a direction parallel to the rotation axis Ax2 and the rotation axis Ax3 (an end face along a direction intersecting the axis Ax0) may be located inside the outer edge of the link base 44. In the width direction, the maximum width of the end face of the protrusion 48a is smaller than the minimum width of the link base 44. The protruding height of the protrusion 48a from the link base 44 may be greater than the protruding height of the surrounding wall 42b from the connection base 42a, and may be greater than the protruding height of the surrounding wall 46b from the connection base 46a.

[0046] The reinforcing portion 48 may include one or more ribs 48b. The rib 48b may be formed so as to protrude from the link base 44 and may be connected to at least the protruding portion 48a. As shown in FIG. 4 and the like, the rib 48b may be formed so as to connect the protruding portion 48a and the connecting portion 42. One end of the rib 48b may be connected to the protruding portion 48a, and the other end of the rib 48b may be connected to the connecting portion 42. Unlike the example shown in FIG. 4 and the like, the rib 48b may be connected to the protruding portion 48a without being connected to the connecting portion 42. In one example, the protruding portion 48a and the rib 48b protrude in the same direction as the surrounding wall 42b of the connecting portion 42, and the rib 48b (the other end of the rib 48b) is connected to the surrounding wall 42b. At least in the extending direction of the link base 44, the protruding height of the rib 48b with respect to the link base 44 may increase as the distance from the protruding portion 48a decreases. In a direction intersecting the extending direction of the link base 44, the protruding height of the rib 48b with respect to the link base 44 may also increase as the distance from the protruding portion 48a decreases.

[0047] The reinforcing portion 48 may include one or more ribs 48c (second ribs). The rib 48c may be formed so as to protrude from the link base 44 and may be connected to at least the protruding portion 48a. As shown in FIG. 4 and the like, the rib 48c may be formed so as to connect the protruding portion 48a and the connecting portion 46. One end of the rib 48c may be connected to the protruding portion 48a, and the other end of the rib 48b may be connected to the connecting portion 46. Unlike the example shown in FIG. 4 and the like, the rib 48c may be connected to the protruding portion 48a without being connected to the connecting portion 46. In one example, the protruding portion 48a and the rib 48c protrude in the same direction as the surrounding wall 46b of the connecting portion 46, and the rib 48c (the other end of the rib 48b) is connected to the surrounding wall 46b. At least in the direction in which the link base 44 extends, the protruding height of the rib 48c with respect to the link base 44 may increase as the distance from the protruding portion 48a decreases. In a direction intersecting the extending direction of the link base 44, the protruding height of the rib 48c with respect to the link base 44 may also increase as the distance from the protruding portion 48a decreases.

[0048] The reinforcing portion 48 may have either one or more ribs 48b or one or more ribs 48c, or may have both one or more ribs 48b and one or more ribs 48c. The reinforcing portion 48 may have a protruding portion 48a without having both one or more ribs 48b and one or more ribs 48c. The following describes an example in which both one or more ribs 48b and one or more ribs 48c are provided.

[0049] The protruding height of the end face of the protruding portion 48a facing away from the link base 44 may be approximately constant. The protruding height of a certain point of the reinforcing portion 48 is defined as the shortest distance between the said point and a reference position set in the link base 44 on a line that passes through the said point and is along the axial direction of the rotation axis Ax2.

[0050] The protrusion 48a may be a solid rib (protrusion) instead of a rib (protrusion) formed in an annular shape. When observing a cross section of the protrusion 48a perpendicular to the rotation axis Ax2, the cross section may be annular or solid (a state in which the inside of the object is filled). In one example, the reinforcing portion 48 includes a plurality of ribs 48b as the one or more ribs 48b, and a plurality of ribs 48c as the one or more ribs 48c.

[0051] Each of the multiple ribs 48b is a rib (convex portion) that connects the protruding portion 48a and the surrounding wall 42b of the connection portion 42. Each of the multiple ribs 48b extends from one of the protruding portion 48a and the surrounding wall 42b to the other. When focusing on each rib 48b included in the multiple ribs 48b, one end of the rib 48b is connected to the protruding portion 48a, and the other end of the rib 48b is connected to the surrounding wall 42b.

[0052] The interval between the multiple ribs 48b may increase as the distance from the protrusion 48a increases. The interval between the multiple ribs 48b is defined as the shortest distance between one rib 48b and another rib 48b in the width direction. When three or more ribs 48b are provided, the interval between at least one arbitrarily selected pair of ribs 48b may increase as the distance from the protrusion 48a increases. In three or more ribs 48b, the interval between the pair of ribs 48b may increase as the distance from the protrusion 48a increases for all combinations of pairs of ribs 48b.

[0053] For at least some of the multiple ribs 48b, the protruding height of the rib 48b may decrease as the distance from the protruding portion 48a increases. In other words, for at least some of the multiple ribs 48b, the protruding height of the rib 48b may increase as the distance from the protruding portion 48a decreases. For all of the multiple ribs 48b, the protruding height of the rib 48b may decrease as the distance from the protruding portion 48a increases.

[0054] Each of the multiple ribs 48c (multiple second ribs) is a rib (convex portion) that connects the protruding portion 48a and the surrounding wall 46b of the connection portion 46. Each of the multiple ribs 48c extends from one of the protruding portion 48a and the surrounding wall 46b to the other. When focusing on each rib 48c included in the multiple ribs 48c, one end of the rib 48c is connected to the protruding portion 48a, and the other end of the rib 48c is connected to the surrounding wall 46b.

[0055] The interval between the multiple ribs 48c may increase as the distance from the protruding portion 48a increases. The interval between the multiple ribs 48c is defined as the shortest distance between one rib 48c and another rib 48c in the width direction. When three or more ribs 48c are provided, the interval between at least one arbitrarily selected pair of ribs 48c may increase as the distance from the protruding portion 48a increases. In three or more ribs 48c, the interval between the pair of ribs 48c may increase as the distance from the protruding portion 48a increases for all combinations of pairs of ribs 48c.

[0056] For at least some of the multiple ribs 48c, the protruding height of the rib 48c may decrease as the distance from the protruding portion 48a increases. In other words, for at least some of the multiple ribs 48c, the protruding height of the rib 48c may increase as the distance from the protruding portion 48a decreases. For all of the multiple ribs 48c, the protruding height of the rib 48c may decrease as the distance from the protruding portion 48a increases.

[0057] <Supporting links> Returning to FIG. 3, the auxiliary link 50 is a link that rotates as the driving link 40 is driven. The auxiliary link 50 extends between the rotation axis Ax2 and the rotation axis Ax3, and may rotate around the rotation axis Ax2 together with the driving link 40. The actuator 120 that rotates the arm link 30 may not be connected to the auxiliary link 50, and the driving force of the actuator 120 may not be directly transmitted to the auxiliary link 50. The actuator 130 that rotates the arm link 60 may not be connected to the auxiliary link 50.

[0058] The auxiliary link 50 may be formed to extend along a line segment that connects the rotation axis Ax2 and the rotation axis Ax3 at the shortest distance, similar to the driving link 40. The actuator 120 and the actuator 130 are each located between the driving link 40 and the auxiliary link 50. The actuator 120 may be disposed between the connection portion 42 of the driving link 40 and a base end portion (an end portion through which the rotation axis Ax2 passes) of the auxiliary link 50. The actuator 130 may be disposed between the connection portion 46 of the driving link 40 and a tip end portion (an end portion through which the rotation axis Ax3 passes) of the auxiliary link 50.

[0059] The robot 1 may include a cable harness 90. The cable harness 90 may be connected to at least the actuator 120, for example. The cable harness 90 may be connected to at least the actuator 130 via the internal space S2 of the pivot link 20. The cable harness 90 may include two or more cables. The cable harness 90 may be connected to at least the actuator 120 and the actuator 130. In the cable harness 90, the cable connected to the actuator 120 may be different from the cable connected to the actuator 130. The cable harness 90 may be physically and electrically connected to each of the actuator 120 and the actuator 130. The cable harness 90 may include at least one of a cable that supplies power to the actuator 120, a cable that supplies power to the actuator 130, a cable that transmits a signal between the actuator 120, and a cable that transmits a signal between the actuator 130. The cable harness 90 may be connected to at least the motor 132 via the inside (internal space S2) of the pivot link 20. The cable harness 90 may be connected to at least the motor 122 and the motor 132 .

[0060] The auxiliary link 50 may have a wiring space S5 that guides the cable harness 90. The wiring space S5 may be a space that guides the cable harness 90 from the internal space S2 to the actuator 130. The cable harness 90 may be housed in the wiring space S5 formed by the auxiliary link 50. The auxiliary link 50 may house the cable harness 90 so that the cable harness 90 is not exposed to the outside.

[0061] The opening 24 of the revolving link 20 described above may be an opening that communicates the internal space S2 of the revolving link 20 with the outside of the internal space S2. The opening 24 may communicate the internal space S2 of the revolving link 20 with the wiring space S5. The cable harness 90 may be wired through the opening 24 and the wiring space S5. The opening 66 (second opening) of the arm link 60 described above may be an opening that communicates the internal space S6 (second internal space) of the arm link 60 with the outside of the internal space S6. The opening 66 may communicate the internal space S6 of the arm link 60 with the wiring space S5. The cable harness 90 may be wired from the internal space S2 to the internal space S6 through the opening 24, the wiring space S5, and the opening 66. The wiring space S5 may be a space that guides the cable harness 90 from the inside of the revolving link 20 (internal space S2) to the inside of the arm base 62 (internal space S6).

[0062] The auxiliary link 50 may be attached to the reinforcing portion 48 of the driving link 40. The auxiliary link 50 is fixed, for example, by a fixing member to the end surface of the protruding portion 48a of the reinforcing portion 48 facing the auxiliary link 50. An internal space S4, which is a space inside the annularly formed protruding portion 48a, and a wiring space S5 in the auxiliary link 50 may be communicated with each other at a connection portion between the auxiliary link 50 and the reinforcing portion 48.

[0063] The auxiliary link 50 may include a link body 52 (sub-link body) and a protrusion 58 (sub-protrusion) (see also FIG. 2). The link body 52 is a main body portion of the auxiliary link 50, and is a portion extending between the rotation axis Ax2 and the rotation axis Ax3. The protrusion 58 is a portion protruding from the link body 52 toward the reinforcing portion 48, and may be formed in an annular shape. The protrusion 58 may be attached to the reinforcing portion 48 of the driving link 40. The protrusion 58 may include an end face facing the driving link 40, and the protrusion 58 and the reinforcing portion 48 may be fixed to each other in a state in which the end face of the protrusion 58 is in contact with a corresponding end face of the protrusion 48a of the reinforcing portion 48.

[0064] The auxiliary link 50 may be attached to the driving link 40 in a state in which it is not constrained by the rotating link 20 in a direction intersecting the rotation axis Ax2. The auxiliary link 50 may be fixed to the driving link 40 in a state in which it is movable relative to the rotating link 20 in a direction intersecting the rotation axis Ax2. The robot 1 may include a bearing that holds the auxiliary link 50 so that it rotates about the rotation axis Ax2.

[0065] The auxiliary link 50 may be attached to the driving link 40 in a state in which it is not constrained by the revolving link 20 in a direction intersecting the rotation axis Ax2 and is not constrained by the arm base 62 (arm link 60) in a direction intersecting the rotation axis Ax3. The auxiliary link 50 may be fixed to the driving link 40 in a state in which it is capable of moving relative to the revolving link 20 in a direction intersecting the rotation axis Ax2 and is capable of moving relative to the arm base 62 (arm link 60) in a direction intersecting the rotation axis Ax3. The robot 1 may include a bearing that holds the auxiliary link 50 so that it rotates about the rotation axis Ax3.

[0066] [seal] FIG. 7 is an enlarged view of the portions indicated by "A" and "B" in FIG. 3, and FIG. 7 shows a schematic diagram of a seal installed between the links. The robot 1 may include a seal 170. The seal 170 is a member (sealing member) interposed between the auxiliary link 50 and the revolving link 20 around the opening 24. The seal 170 may be configured to seal between the auxiliary link 50 and the revolving link 20 (to close the gap between the auxiliary link 50 and the revolving link 20). For example, the presence of the seal 170 at the connection portion between the auxiliary link 50 and the revolving link 20 prevents liquid such as water from entering the internal space S2 of the revolving link 20 from the outside through the connection portion, and prevents liquid such as water from entering the wiring space S5.

[0067] The seal 170 may be configured to be interposed between the auxiliary link 50 and the revolving link 20 (to seal between the auxiliary link 50 and the revolving link 20) ​​while allowing relative displacement between the auxiliary link 50 and the revolving link 20 in a direction intersecting the rotation axis Ax2. The seal 170 includes, for example, a first member 172 and a second member 174. Each of the first member 172 and the second member 174 is formed in an annular shape along the rotation axis Ax2. The first member 172 and the second member 174 are arranged to face each other in the axial direction of the rotation axis Ax2. The first member 172 is connected to an inner wall surface that forms the opening 24 in the revolving link 20. The second member 174 is connected to a portion of the base end of the auxiliary link 50 that is attached to the revolving link 20.

[0068] The first member 172 and the second member 174 are in contact with each other while allowing relative displacement between them. The first member 172 includes a seal surface 172a. The seal surface 172a is a surface along a plane intersecting the rotation axis Ax2. The seal surface 172a may be along a plane perpendicular to the rotation axis Ax2. The seal surface 172a is formed in an annular shape around the rotation axis Ax2.

[0069] The second member 174 includes a seal element 174a. The seal element 174a is an element (part) that is in close contact with the seal surface 172a of the first member 172 and displaces along the seal surface 172a in response to the relative displacement between the auxiliary link 50 and the revolving link 20. The seal 170 is configured so that the seal element 174a maintains contact with the seal surface 172a even when the auxiliary link 50 and the revolving link 20 are displaced relative to each other. The seal element 174a is formed in an annular shape around the rotation axis Ax2. The seal element 174a may be formed to extend from the main body of the second member 174 in the radial direction of a circle centered on the rotation axis Ax2 while being inclined toward the rotation axis Ax2.

[0070] The seal 170, including the sealing surface 172a and the sealing element 174a, may be configured in any manner. A first member 172, including the sealing surface 172a, may be provided on the auxiliary link 50, and a second member 174, including the sealing element 174a, may be provided on the pivot link 20.

[0071] The robot 1 may include a seal 180 (second seal) in addition to the seal 170. The seal 180 is a member (sealing member) interposed between the auxiliary link 50 and the arm base 62 of the arm link 60 around the opening 66. The seal 180 may be configured to seal between the auxiliary link 50 and the arm base 62 (to close the gap between the auxiliary link 50 and the arm base 62). For example, the seal 180 is interposed at the connection portion between the auxiliary link 50 and the arm base 62 of the arm link 60, thereby preventing liquid such as water from entering the internal space S6 of the arm link 60 from the outside and liquid such as water from entering the wiring space S5 through the connection portion.

[0072] The seal 180 may be configured to be interposed between the auxiliary link 50 and the arm base 62 (to seal between the auxiliary link 50 and the arm base 62) while allowing relative displacement between the auxiliary link 50 and the arm base 62 in a direction intersecting the rotation axis Ax3. The seal 180 includes, for example, a first member 182 and a second member 184. The first member 182 and the second member 184 are disposed to face each other in the axial direction of the rotation axis Ax3. The first member 182 is connected to an inner wall surface that forms the opening 66 in the arm base 62. The second member 184 is connected to a portion of the tip of the auxiliary link 50 that is attached to the arm base 62.

[0073] The first member 182 and the second member 184 are in contact with each other while allowing relative displacement between them. The first member 182 includes a seal surface 182a. The seal surface 182a is a surface along a plane intersecting the rotation axis Ax3. The seal surface 182a may be along a plane perpendicular to the rotation axis Ax3. The seal surface 182a is formed in an annular shape around the rotation axis Ax3.

[0074] The second member 174 includes a seal element 184a. The seal element 184a is an element (part) that is in close contact with the seal surface 182a of the first member 182 and displaces along the seal surface 182a in response to the relative displacement between the auxiliary link 50 and the arm link 60. The seal 180 is configured such that the seal element 184a maintains contact with the seal surface 182a even when the auxiliary link 50 and the arm link 60 are displaced relative to each other. The seal element 184a is formed in an annular shape around the rotation axis Ax3. The seal element 184a may be formed to extend from the main body of the second member 184 in the radial direction of a circle centered on the rotation axis Ax3 while being inclined toward the rotation axis Ax3.

[0075] The seal 180, including the sealing surface 182a and the sealing element 184a, may be configured in any manner. A first member 182, including the sealing surface 182a, may be provided on the auxiliary link 50, and a second member 184, including the sealing element 184a, may be provided on the arm base 62.

[0076] When the materials forming the driving link 40 and the auxiliary link 50 are different from each other, the difference in the thermal expansion coefficients of the materials may cause the deformation of the driving link 40 and the deformation of the auxiliary link 50 due to thermal expansion or the like to differ. In contrast, the seals 170 and 180 do not restrict the movement of the auxiliary link 50 in a direction intersecting the rotation axis, and therefore can tolerate positional deviations (e.g., deviations of the rotation axis) caused by differences in deformation between the links.

[0077] [Motor maintenance structure] Next, a structure for performing maintenance on the motor of the actuator provided in the robot 1 will be described. The maintenance of the motor may include replacing the motor. Fig. 8 shows the robot 1 in a state where some members have been moved so that the inside of the revolving link 20 can be seen. Fig. 9 is a cross-sectional view showing the inside of the revolving link 20. Fig. 10 shows the robot 1 in a state where some members have been moved so that the inside of the arm base 62 of the arm link 60 can be seen.

[0078] 8, the revolving link 20 is provided with an opening 24. The opening 24 (access opening) may be an opening that allows the motor 122 of the actuator 120 to be inserted into and removed from the revolving link 20 from a direction D1 (first direction) along the rotation axis Ax2. The opening 24 may have a size that allows the motor 122 to be inserted and removed. The housing 21 that forms the internal space S2 of the revolving link 20 may include a pair of side walls that intersect with the rotation axis Ax2, and a peripheral wall that connects parts of the outer edges of the pair of side walls around the rotation axis Ax2. The opening 24 may be provided in one of the pair of side walls that is closer to the auxiliary link 50.

[0079] The motor 122 may be capable of being inserted into and removed from the internal space S2 of the revolving link 20 in a direction D1. The direction D1 is, for example, a direction in which the revolving link 20 and the driving link 40 are aligned on the rotation axis Ax2. The direction D1 may be perpendicular to a plane including the opening 24 (a plane including an opening edge that forms the opening 24). The motor 122 may be inserted into and removed from the internal space S2 with its output shaft 122b horizontal and aligned along the direction D1. The motor 122 is inserted and removed by, for example, an operator.

[0080] The robot 1 may include an access cover 54. The access cover 54 is a cover that covers the opening 24 provided in the revolving link 20. The access cover 54 may be attached to the revolving link 20 so as to cover the motor 122 from the direction D1, and may be configured to be detached from the revolving link 20 so as to allow the motor 122 to be inserted into and removed from the revolving link 20 from the direction D1. The access cover 54 may be a part of the auxiliary link 50. The base end of the auxiliary link 50 may function as the access cover 54. When attaching the motor 122, for example, an operator removes the access cover 54 and then inserts the motor 122 into the internal space S2 so that the output shaft 122b is connected to the reducer 124 housed in the connection portion 42 of the drive link 40.

[0081] In addition to the opening 24, an opening 26 may be provided in the rotating link 20 (housing 21). The opening 26 may be provided in the peripheral wall of the housing 21. The opening 26 (check opening) is an opening that allows the actuator 120 to be viewed from a direction D2 (second direction) intersecting with the rotation axis Ax2. The opening 26 allows an operator to view the motor 122 when inserting or removing the motor 122. The operator may be able to view the motor 122 through the opening 26 from the direction D2. The direction D2 is a direction intersecting a plane including the opening 26 (a plane including an opening edge that forms the opening 26). The opening 26 is formed so as to be located above the motor 122 in a state where it is attached in the internal space S2. At least a part of the component of the direction D2 may be a component that faces vertically downward. The opening 26 may have a size that does not allow the motor 122 to be inserted or removed through the opening.

[0082] The robot 1 may include a check cover 92. The check cover 92 is a cover that covers the opening 26 provided in the revolving link 20. The check cover 92 may be attached to the revolving link 20 so as to cover the motor 122 from the direction D2, and may be configured to be detached from the revolving link 20 so as to make the motor 122 visible from the direction D2. The check cover 92 may be attached to the revolving link 20 so as to cover the motor 122 from above. When attaching the motor 122, for example, an operator removes the check cover 92 and then performs the work while visually checking the state of the output shaft 122b, such as the inclination, through the opening 26.

[0083] The robot 1 may include a check seal 93 (first check seal). The check seal 93 is a seal member interposed between the check cover 92 and the rotating link 20. The check seal 93 may be configured to seal between the check cover 92 and the rotating link 20. The check seal 93 is provided, for example, along an opening edge that forms the opening 26. Providing the check seal 93 prevents a substance such as liquid from entering the internal space S2 from the outside through the connection portion between the check cover 92 and the rotating link 20, and prevents a substance such as liquid from leaking out of the internal space S2.

[0084] In addition to the openings 24 and 26, an opening 28 may be formed in the housing 21. The opening 28 (sub-access opening) may be provided in the peripheral wall of the housing 21. The opening 28 is an opening that allows access to the motor 122 from a direction D3 (third direction) intersecting the directions D1 and D2. The ability to access the motor 122 means that the worker himself can touch the motor 122, or that a tool operated by the worker can touch the motor 122. The direction D3 is a direction intersecting a plane including the opening 28 (a plane including an opening edge that forms the opening 28).

[0085] An actuator 110 may be housed in the internal space S2 of the housing 21. A motor included in the actuator 110 is referred to as a "motor 112", and a reducer included in the actuator 110 is referred to as a "reducer 114". The motor 112 (base motor) is housed in the revolving link 20 and rotates the revolving link 20 around a rotation axis Ax1 (base axis). The opening 28 may have a size that allows the motor 112 to be inserted and removed from the revolving link 20. For example, an operator can insert the motor 112 into the internal space S2 in the revolving link 20 through the opening 28, and can remove the motor 112 from the internal space S2.

[0086] The robot 1 may include a sub-access cover 94. The sub-access cover 94 is a cover that covers the opening 28 provided in the revolving link 20. The sub-access cover 94 may be configured to be attached to the revolving link 20 so as to cover the motor 122 from the direction D3, and to be configured to enable access to the motor 122 from the direction D3 by being detached from the revolving link 20. When attaching the motor 122, for example, an operator removes the sub-access cover 94, and then inserts his / her hand into the internal space S2 through the opening 28 to support the motor 122 from below, and performs the attachment work of the motor 122 so that the output shaft 122b of the motor 122 is connected to the reducer 124.

[0087] As shown in Fig. 9, the lower end of the motor 122 may be located above the upper end of the motor 112. The upper edge of the opening 28 may be located above the upper end of the motor 112, and the lower edge of the opening 28 may be located below the upper end of the motor 122. The upper edge of the opening 28 may be located above the lower end of the motor 122. The relative positions of the motor 112, the motor 122, and the opening 28 refer to the relationship in a state in which the motor 112 and the motor 122 are attached. In Fig. 9, the position of the upper edge of the opening 28 in the axial direction of the rotation axis Ax1 is indicated by "H2", and the position of the lower edge of the opening 28 in the axial direction of the rotation axis Ax1 is indicated by "H1".

[0088] 10, an opening 66 may be provided in the arm base 62. The opening 66 (second access opening) may be an opening that allows the motor 132 of the actuator 130 to be inserted into and removed from the arm base 62 from a direction D11 (third direction) along the rotation axis Ax3. The opening 66 may have a size that allows the motor 132 to be inserted and removed. The housing 65 in the arm base 62 may include at least a pair of side walls that intersect with the rotation axis Ax3. The opening 66 may be provided in one of the pair of side walls of the housing 65, the side wall closer to the auxiliary link 50.

[0089] The motor 132 may be capable of being inserted into and removed from the internal space S6 of the arm base 62 in a direction D11. The direction D11 is, for example, a direction in which the arm base 62 and the driving link 40 are aligned on the rotation axis Ax3. The direction D11 may be perpendicular to a plane including the opening 66 (a plane including an opening edge that forms the opening 66). The motor 132 may be inserted into and removed from the internal space S6 with its output shaft 132b horizontal and aligned along the direction D11. The motor 132 is inserted and removed by, for example, an operator.

[0090] The robot 1 may include an access cover 56 (second access cover). The access cover 56 is a cover that covers the opening 66. The access cover 56 may be configured to be attached to the arm base 62 so as to cover the motor 132 from the direction D11, and to be detachable from the arm base 62 so as to allow the motor 132 to be inserted into and removed from the arm base 62 from the direction D11. The access cover 56 may be a part of the auxiliary link 50. The tip of the auxiliary link 50 may function as the access cover 56.

[0091] When a part of the auxiliary link 50 functions as an access cover 54 that covers the motor 122, and another part of the auxiliary link 50 functions as an access cover 56 that covers the motor 132, the robot 1 includes a connection member 55 that configures the auxiliary link 50 (sub-link). The connection member 55 is a part that connects the access cover 54 and the access cover 56 of the auxiliary link 50 and extends from the access cover 54 to the access cover 56. The connection member 55 is formed, for example, so as to extend along a line segment that connects the rotation axis Ax2 and the rotation axis Ax3 at the shortest distance, and one end of the connection member 55 is connected to the access cover 54, and the other end of the connection member 55 is connected to the access cover 56. The connection member 55 is attached to the drive link 40.

[0092] As described above, the auxiliary link 50 may include the link body 52 and the protrusion 58. The link body 52 may be composed of the access covers 54 and 56 and a part of the connecting member 55, and the protrusion 58 may be composed of another part of the connecting member 55. As described above, the protrusion 58 of the connecting member 55 may be fixed to the reinforcing portion 48 (protrusion 48a) of the driving link 40, thereby attaching the connecting member 55 to the driving link 40.

[0093] The access cover 54 may be formed by a portion of the link body 52 that covers the motor 122 and a portion connected to the seal 170. The above-mentioned seal 170 (first access seal) may be interposed between the pivot link 20 and the access cover 54 while allowing rotation of the auxiliary link 50 relative to the pivot link 20. The access cover 56 may be formed by a portion of the link body 52 that covers the motor 132 and a portion connected to the seal 180. The above-mentioned seal 180 (second access seal) may be interposed between the arm base 62 and the access cover 56 while allowing rotation of the auxiliary link 50 relative to the arm base 62.

[0094] When installing the motor 132, for example, an operator removes the access cover 56 and then inserts the motor 132 into the internal space S6 so that the output shaft 132b is connected to the reducer 134 housed in the connection portion 46 of the drive link 40.

[0095] In addition to the opening 66, an opening 67 may be provided in the arm base 62 (housing 65). The opening 67 (second check opening) is an opening that allows the motor 132 to be viewed from a direction D4 (fourth direction) intersecting with the rotation axis Ax3. The opening 67 allows an operator to view the motor 132 when inserting or removing the motor 132. The operator may be able to view the motor 132 through the opening 67 from the direction D4. The direction D4 is a direction that intersects with a plane including the opening 67 (a plane including an opening edge that forms the opening 67).

[0096] The robot 1 may include a check cover 96 (second check cover). The check cover 96 is a cover that covers an opening 67 provided in the arm base 62. The check cover 96 may be configured to be attached to the arm base 62 so as to cover the motor 132 from the direction D4, and to be detachable from the arm base 62 so as to make the motor 132 visible from the direction D4. When attaching the motor 132, for example, an operator removes the check cover 96 and then performs the work while visually checking the state of the output shaft 132b, such as the inclination, through the opening 67.

[0097] The robot 1 may include a check seal 97 (second check seal). The check seal 97 is a seal member interposed between the check cover 96 and the arm base 62. The check seal 97 may be configured to seal between the check cover 96 and the arm base 62. The check seal 97 is provided, for example, along an opening edge that forms the opening 67. Providing the check seal 97 prevents a substance such as liquid from entering the internal space S6 through the connection portion between the check cover 96 and the arm base 62, and prevents a substance such as liquid from leaking out of the internal space S6.

[0098] The actuator 140 includes a motor 142 (third motor). The motor 142 rotates the swivel arm 64 relative to the arm base 62, for example, around a rotation axis Ax4 (third rotation axis) along the direction in which the arm base 62 extends. The motor 142 may be housed in the arm base 62. The motor 142 may be installed so that its output shaft is horizontal.

[0099] The motor 142 may be capable of being inserted into and removed from the internal space S6 of the arm base 62 in a direction D4 (e.g., a direction along the rotation axis Ax4). The motor 142 may be inserted into and removed from the internal space S6 with its output shaft horizontal and along the rotation axis Ax4. The motor 142 is inserted and removed, for example, by an operator. The opening 67 may have a size that allows the motor 142 to be inserted and removed from the arm base 62. The operator can view the motor 132 through the opening 67, and the motor 142 may be inserted and removed from the arm base 62.

[0100] In addition to the openings 66 and 67, an opening 68 may be provided in the arm base 62 (housing 65). The opening 68 (third check opening) is an opening that allows the motor 142 to be viewed from a direction D5 intersecting the rotation axis Ax4. The opening 68 allows an operator to view the motor 142 when inserting or removing the motor 142. The operator may be able to view the motor 142 through the opening 68 from the direction D5. The direction D5 is a direction that intersects with a plane that includes the opening 68 (a plane that includes an opening edge that forms the opening 68).

[0101] The robot 1 may include a check cover 98 (third check cover). The check cover 98 is a cover that covers an opening 68 provided in the arm base 62. The check cover 98 may be configured to be attached to the arm base 62 so as to cover the motor 142 from the direction D5, and to be detached from the arm base 62 so as to make the motor 142 visible from the direction D5. When attaching the motor 142, for example, the worker removes the check cover 98 and then performs the work while visually checking the state of the motor 142, such as its inclination, through the opening 68.

[0102] In the above example, a case has been described in which the entire drive link 40 is detached from other members to allow the motor 122 and the motor 132 to be inserted or removed. Instead of the entire drive link 40, a cover portion included in the drive link 40 may be detached from the remaining portion of the drive link 40 to allow the motor 122 and the motor 132 to be inserted or removed. As shown in Fig. 3, the link main body 52 of the auxiliary link 50 may include a main body portion 52a and a cover portion 52b (see also Figs. 7 and 8).

[0103] The cover portion 52b may be attached to the main body portion 52a via a fixing member 53c. A part of the seal 170 and a part of the seal 180 described above may be provided on the main body portion 52a. In a state in which the cover portion 52b is removed from the main body portion 52a (before being attached to the main body portion 52a), a worker may perform an attachment operation between the protrusion 58 of the auxiliary link 50 and the reinforcing portion 48 of the driving link 40 via a fixing member. In a state in which the cover portion 52b is removed from the main body portion 52a fixed to the driving link 40 (before being attached to the main body portion 52a), a worker may perform an operation of wiring the cable harness 90.

[0104] By removing the cover portion 52b from the main body portion 52a fixed to the drive link 40, the motor 122 can be taken in and out through the opened wiring space S5 and the opening 24, and the motor 132 can be taken in and out through the opened wiring space S5 and the opening 66. Of the cover portion 52b which is part of the drive link 40, a portion covering the opening 24 from the direction D1 along the rotation axis Ax2 may function as the above-mentioned access cover 54. Of the cover portion 52b which is part of the drive link 40, a portion covering the opening 66 from the direction D11 along the rotation axis Ax3 may function as the above-mentioned access cover 56.

[0105] [Variations] In the arm link 30, the driving link 40 and the auxiliary link 50 may be made of the same material. For example, the driving link 40 may be made of a material containing aluminum, and the auxiliary link 50 may be made of a material containing aluminum. Since the actuators 120 and 130 are connected to the driving link 40, the driving link 40 and the auxiliary link 50 are differently affected by heat from the actuators. As a result, even if the driving link 40 and the auxiliary link 50 are made of the same material, the deformation of the driving link 40 and the deformation of the auxiliary link 50 caused by thermal expansion or the like may differ. Therefore, even if the driving link 40 and the auxiliary link 50 are made of the same material, a seal 170 and a seal 180 that do not restrict movement of the auxiliary link 50 in a direction intersecting the rotation axis may be provided to allow positional deviation (for example, deviation of the rotation axis) caused by the difference in deformation between the links.

[0106] 11, the robot 1 may include a bearing 178 and a bearing 188 instead of the seal 170 and the seal 180. The bearing 178 is a bearing member that holds the auxiliary link 50 so that it rotates about the rotation axis Ax2. By providing the bearing 178, the relative movement of the auxiliary link 50 with respect to the revolving link 20 in the direction intersecting the rotation axis Ax2 may be restricted.

[0107] The bearing 188 (second bearing) is a bearing member that holds the auxiliary link 50 so as to rotate about the rotation axis Ax3 with respect to the arm base 62. By providing the bearing 188, the relative movement of the auxiliary link 50 with respect to the arm base 62 in a direction intersecting the rotation axis Ax3 may be restricted. Each of the bearings 178 and 188 may be any type of bearing member, for example, a ball bearing or a roller bearing. The robot 1 may be provided with the bearing 178 in addition to the seal 170. The robot 1 may be provided with the bearing 188 in addition to the seal 180.

[0108] 1 to 10, the material forming the driving link 40 and the material forming the auxiliary link 50 are different from each other, and the bearings 178 and 188 are not provided. When the material forming the driving link 40 and the material forming the auxiliary link 50 are different from each other, the bearings 178 and 188 may be provided. When the material forming the driving link 40 and the material forming the auxiliary link 50 are the same from each other, the bearings 178 and 188 do not have to be provided, or the bearings 178 and 188 may be provided.

[0109] In one example among the various examples described above, at least a part of the matters described in the other examples may be combined.

[0110] [Summary of this disclosure] This disclosure includes the following configurations [1] to

[17] .

[0111] [1] A robot (1) comprising: a link (40); and an actuator (120) that rotates the link (40) about a rotation axis (Ax2), wherein the link (40) has a connection part (42) connected to the actuator (120), a link base (44) extending from the connection part (42) and intersecting the rotation axis (Ax2), and a protrusion (48a) that protrudes from the link base (44) between the connection part (42) and an end of the link base (44) at a position spaced apart from each of the connection part (42) and the end of the link base (44). In the robot 1, the protrusion 48a imparts high rigidity to the link base 44 while thinning the link base 44. Thus, the robot 1 is effective in achieving both weight reduction and increased rigidity.

[0112] [2] The robot (1) described in [1] above, wherein the link (40) further has a rib (48b) protruding from the link base (44), the rib (48b) being connected to at least the protruding portion (48a). In this case, the link base 44 is reinforced by the protrusion 48a and the rib 48b, which makes it possible to impart even higher rigidity to the link base 44.

[0113] [3] The robot (1) according to the above [2], wherein the rib (48b) connects the protruding portion (48a) and the connecting portion (42). In this case, the reinforcing effect of the portion including the protrusion 48a extends to the connection portion 42, so that the link base 44 can be made thinner while still providing higher rigidity to the link base 44. This is effective in achieving both weight reduction and increased rigidity at the same time.

[0114] [4] The robot (1) according to the above item [2] or [3], wherein the protruding height of the rib (48b) relative to the link base (44) increases as the distance from the protruding portion (48a) decreases, at least in the direction in which the link base (44) extends. In this case, by extending the reinforcing effect of the portion including the protrusion (48a) from the protrusion (48a) to a position distal to the protrusion (48a) while increasing the protruding height of the rib (48b) as the distance to the protrusion (48a) decreases, it is possible to further achieve both weight reduction and increased rigidity.

[0115] [5] The robot (1) described in [4] above, wherein the protruding height of the rib (48b) from the link base (44) increases as the distance from the protruding portion (48a) decreases, even in a direction intersecting the extension direction of the link base (44). In this case, by increasing the protruding height of the rib (48b) in accordance with the reduction in the distance to the protruding portion (48a) in the intersecting direction, it is possible to further achieve both weight reduction and increased rigidity.

[0116] [6] The robot (1) described in [3] above, wherein the connection portion (42) has a connection base (42a) connected to the link base (44) and connected to the actuator (120), and a surrounding wall (42b) protruding from the connection base (42a) so as to surround at least a portion of the actuator (120), the protrusion (48a) and the rib (48b) protruding in the same direction as the surrounding wall (42b), and the rib (48b) is connected to the surrounding wall (42b). In this case, the surrounding wall 42b imparts high rigidity to the connecting base 42a, while the connecting base 42a can be made thinner. Furthermore, by connecting the protruding portion 48a to the surrounding wall 42b via the rib 48b, the rigidity of the entire link 40 can be further improved. This is therefore effective in achieving both weight reduction and improved rigidity at the same time.

[0117] [7] The robot (1) described in [6] above, wherein the link (40) has a plurality of ribs (48b) including a rib (48b), each of the plurality of ribs (48b) connecting the protrusion (48a) and the surrounding wall (42b), and the spacing between the plurality of ribs (48b) increases as the distance from the protrusion (48a) increases. In this case, it is possible to improve both the bending rigidity and the torsional rigidity of the link base portion (44).

[0118] [8] The robot (1) according to any one of the above [1] to [7], wherein the protrusion (48a) is formed in a ring shape around an axis (Ax0) intersecting the link base (44). In this case, the weight of the protrusion (48a) can be reduced.

[0119] [9] The robot (1) according to any one of [3] to [6] above, further comprising: a second link (60, 62) connected to an end of the link (40); and a second actuator (130) that rotates the second link (60, 62) around a second rotation axis (Ax3) parallel to the rotation axis (Ax2), wherein the link (40) further has a second connection portion (46) connected to the second actuator (130) and a second rib (48c) that connects the protrusion (48a) and the second connection portion (46). In this case, by connecting the protrusion (48a) to the connecting portion (42) and the second connecting portion (46) via the rib (48b) and the second rib (48c), it is possible to impart higher rigidity to the link base (44) while reducing the thickness of the link base (44). The increased rigidity of the link base (44) also contributes to improved positioning accuracy of the tips of the second links (60, 62).

[0120]

[10] The connection portion (42) has a connection base (42a) connected to the link base (44) and connected to the actuator (120), and a surrounding wall (42b) protruding from the connection base (42a) so as to surround at least a portion of the actuator (120). The second connection portion (46) has a second connection base (46a) connected to the link base (44) and connected to the second actuator (130), and a surrounding wall (42b) protruding from the connection base (42a) so as to surround at least a portion of the actuator (120). and a second surrounding wall (46b) protruding from the second connection base (46a) so as to surround at least a portion of the surrounding wall (42b) (42c), wherein the protrusion (48a), the rib (48b), and the second rib (48c) protrude in the same direction as the surrounding wall (42b) and the second surrounding wall (46b), the rib (48b) is connected to the surrounding wall (42b), and the second rib (48c) is connected to the second surrounding wall (46b). In this case, the surrounding wall (42b) can impart high rigidity to the connection base (42a) while thinning the connection base (42a). Similarly, the second surrounding wall (46b) can impart high rigidity to the second connection base (46a) while thinning the second connection base (46a). Furthermore, by connecting the protrusion (48a) to the surrounding wall (42b) and the second surrounding wall (46b) via the rib (48b) and the second rib (48c), the rigidity of the entire link (40) can be further improved. This is therefore effective in achieving both weight reduction and improved rigidity at the same time.

[0121]

[11] The robot (1) described in

[10] above, wherein the link (40) has a plurality of ribs (48b) including a rib (48b) and a plurality of second ribs (48c) including a second rib (48c), each of the plurality of ribs (48b) connecting the protrusion (48a) and the surrounding wall (42b), each of the plurality of second ribs (48c) connecting the protrusion (48a) and the second surrounding wall (46b), the spacing between the plurality of ribs (48b) increasing with the distance from the protrusion (48a), and the spacing between the plurality of second ribs (48c) increasing with the distance from the protrusion (48a). In this case, both the bending rigidity and the torsional rigidity of the link base portion (44) can be further improved.

[0122]

[12] The robot (1) according to any one of the above [9] to

[11] , further comprising a sub-link (50) extending between the rotation axis (Ax2) and the second rotation axis (Ax3) and rotating together with the link (40) about the rotation axis (Ax2), wherein the actuator (120) and the second actuator (130) are each located between the link (40) and the sub-link (50), and the sub-link (50) is attached to the protrusion (48). In this case, the actuator (120) and the second actuator (130) can be housed between the link (40) and the sub-link (50), thereby reducing irregularities in the appearance of the robot (1).

[0123]

[13] The robot (1) described in

[12] above, further comprising a cable harness (90) connected to at least a second actuator (130) via a space accommodating the actuator (120), wherein the sub-link (50) has a wiring space (S5) for guiding the cable harness (90) from the space accommodating the actuator (120) to the second actuator (130). In this case, the space inside the sub-link (50) can be effectively utilized for wiring the cable harness (90).

[0124]

[14] The robot (1) described in

[13] above, wherein the protrusion (48a) is formed in a ring shape around an axis (Ax0) intersecting the link base (44), and an internal space (S4) of the protrusion (48a) and a wiring space (S5) are connected to each other at a connection portion between the sub-link (50) and the protrusion (48). In this case, the weight of the arm link (30) can be further reduced.

[0125]

[15] The robot (1) described in any one of

[12] to

[14] above, wherein the sub-link (50) has a sub-link main body (52) extending between the rotation axis (Ax2) and the second rotation axis (Ax3) and a sub-protrusion (58) protruding from the sub-link main body (52) toward the protrusion (48), and the sub-protrusion (58) is attached to the protrusion (48). In this case, the sub-link (50) can be easily positioned relative to the link (40).

[0126]

[16] The robot (1) according to any one of the above

[12] to

[14] , further comprising: a bearing (178) that holds the sub-link (50) so as to rotate about the rotation axis (Ax2); and a second bearing (188) that holds the sub-link (50) so as to rotate about a second rotation axis (Ax3) relative to the second link (60, 62). In this case, the link (40) can be reinforced by the sub-link (50).

[0127]

[17] The robot (1) according to any one of the above

[12] to

[14] , wherein the link (40) is formed from a first material, and the sub-link (50) is formed from a second material having a lower rigidity and specific gravity than the first material. In this case, different materials are used for areas where rigidity is required and areas where high rigidity is not required, so that it is possible to achieve both weight reduction and improved rigidity at the same time.

[0128]

[18] The robot (1) according to any one of [9] to

[14] above, further comprising: a base link (10) fixed to an installation surface; and a rotating link (20) connected to the base link (10) so as to rotate about a rotating axis (Ax1) intersecting the rotation axis (Ax2), wherein the link (40) is connected to the rotating link (20), the actuator (120) rotates the link (40) about the rotation axis (Ax2) relative to the rotating link (20), and the second link (60, 62) extends away from the second rotation axis (Ax3). In this case, by achieving both weight reduction and rigidity improvement in the link of the robot (1) closer to the installation surface, it is possible to achieve weight reduction and rigidity improvement of the entire robot. [Explanation of symbols]

[0129] 1...robot, 10...base link, 20...swivel link, S2...internal space, 24, 28...opening, 30...arm link, 40...driving link, 42, 46...connection portion, 42a, 46a...connection base, 42b, 46b...enclosure wall, 44...link base, 48...reinforcement portion, 48a...protrusion, S4...internal space, Ax0...axis, 48b, 48c...rib, 50...auxiliary link, S5...wiring space, 52...link body, 58...protrusion, 54...access cover, 55...connection member, 56...access cover, 6 0...arm link, 62...arm base, S6...internal space, 66, 67...opening, 64...swivel arm, 90...cable harness, 92, 96, 98...check cover, 93, 97...check seal, 94...sub-access cover, Ax1 to Ax4...rotation axis, 110, 120, 130, 140...actuator, 112, 122, 132, 142...motor, 170, 180...seal, 172a, 182a...seal surface, 174a, 184a...seal element, 178, 188...bearing.

Claims

1. Links, an actuator that rotates the link about a rotation axis; Equipped with The link is: A connection portion connected to the actuator; a link base portion extending from the connection portion and intersecting the rotation axis; a protrusion protruding from the link base at a position separated from each of the connection portion and the end portion of the link base, between the connection portion and the end portion of the link base, robot.

2. The link further includes a rib protruding from the link base, The rib is connected to at least the protrusion. The robot according to claim 1.

3. The rib connects the protrusion and the connection portion. The robot according to claim 2.

4. At least in a direction in which the link base extends, a protruding height of the rib relative to the link base increases as a distance from the protruding portion decreases. The robot according to claim 2 or 3.

5. Also in a direction intersecting the extending direction of the link base, the protruding height of the rib with respect to the link base increases as the distance from the protruding portion decreases. The robot according to claim 4.

6. The connection portion is a connection base connected to the link base and connected to the actuator; a surrounding wall protruding from the connection base so as to surround at least a portion of the actuator; having The protrusion and the rib protrude in the same direction as the surrounding wall, The rib is connected to the surrounding wall. The robot according to claim 3.

7. The link has a plurality of ribs including the rib, Each of the plurality of ribs connects the protrusion and the surrounding wall, The spacing between the ribs increases with increasing distance from the protrusion. The robot according to claim 6.

8. The protrusion is formed in an annular shape around an axis that intersects with the link base. The robot according to any one of claims 1 to 3.

9. a second link connected to an end of the link; a second actuator that rotates the second link about a second rotation axis that is parallel to the rotation axis; Further comprising: The link is: A second connection portion connected to the second actuator; A second rib connecting the protruding portion and the second connection portion. The robot according to claim 3.

10. The connection portion is a connection base connected to the link base and connected to the actuator; a surrounding wall protruding from the connection base so as to surround at least a portion of the actuator; having The second connection portion is a second connection base connected to the link base and connected to the second actuator; a second surrounding wall protruding from the second connection base so as to surround at least a portion of the second actuator; having the protrusion, the rib, and the second rib protrude in the same direction as the surrounding wall and the second surrounding wall, The rib is connected to the surrounding wall, The second rib is connected to the second surrounding wall. The robot according to claim 9.

11. the link has a plurality of ribs including the rib and a plurality of second ribs including the second rib, Each of the plurality of ribs connects the protrusion and the surrounding wall, Each of the plurality of second ribs connects the protrusion and the second surrounding wall, The spacing between the ribs increases as the distance from the protruding portion increases, The intervals between the second ribs increase as the distance from the protruding portion increases. The robot according to claim 10.

12. a sub-link extending between the rotation axis and the second rotation axis and rotating about the rotation axis together with the link; each of the actuator and the second actuator is located between the link and the sub-link; The sub-link is attached to the protrusion. The robot according to claim 9.

13. a cable harness connected to at least the second actuator via a space that accommodates the actuator; The sub-link has a wiring space for guiding the cable harness from a space accommodating the actuator to the second actuator. The robot of claim 12.

14. The protrusion is formed in an annular shape around an axis that intersects with the link base, an internal space of the protrusion and the wiring space communicate with each other at a connection portion between the sub-link and the protrusion; The robot according to claim 13.

15. The sub-link is A sub-link body extending between the rotation axis and the second rotation axis; A sub-projection portion projecting from the sub-link body toward the projection portion; having The sub-projection is attached to the projection. The robot according to any one of claims 12 to 14.

16. a bearing that holds the sub-link so as to rotate about the rotation axis; a second bearing that holds the sub-link so as to rotate about the second axis of rotation relative to the second link; Further comprising: The robot according to any one of claims 12 to 14.

17. the link is formed from a first material; The sub-link is formed of a second material having a smaller rigidity and specific gravity than the first material. The robot according to any one of claims 12 to 14.

18. A base link fixed to an installation surface; a pivot link connected to the base link so as to rotate about a pivot axis that intersects the rotation axis; Further comprising: The link is connected to the pivot link; The actuator rotates the link about the rotation axis relative to the pivot link, The second link extends away from the second axis of rotation. The robot according to any one of claims 9 to 14.

Images