Patent Description:
<CIT> discloses a robot including a link portion whose base end side in the longitudinal direction is rotatably coupled to a predetermined member. The link part is manufactured from a welded steel pipe and formed into a cylindrical shape, and a cross-sectional shape in a direction perpendicular to the longitudinal direction is an elliptical shape or a shape in which at least one of corners of a rectangular shape are curved. The welded portion of the welded steel pipe is formed at a portion having a small stress set based on a stress distribution indicating the magnitude of the stress of the link portion.

<CIT> discloses a robot comprising an articulated arm; and a base unit to which the articulated arm is operably coupled, the base unit comprising: a rotating portion; a motor mounted on the rotating portion and configured to rotate the rotating portion about a first axis; an arm connector located at a first portion of the rotating portion, wherein the articulated arm is connected to the arm connector to swing about a second axis; and a rib connecting the arm connector to a second portion of the rotating portion, wherein the motor is located between the first portion and the second portion of the rotating portion. Some further robots are disclosed in <CIT> and <CIT>.

The present disclosure provides a robot effective for downsizing.

According to the invention, a robot according to claim <NUM> is provided.

Some further embodiments of such a robot are defined in the dependent claims.

According to the present disclosure, a robot effective for downsizing can be provided.

Hereinafter, embodiments will be described in detail with reference to the drawings. In the description, the same element or the element having the same function is denoted by the same reference numeral, and the overlapping description is omitted.

A robot <NUM> shown in <FIG> is a so-called a vertical articulated robot, which automatically performs various operations on a work object. As a specific example of the robot <NUM>, an industrial robot that automatically performs various kinds of transportation, processing, assembly, and the like on a part, an assembly, or the like in a production line of a product is exemplified, but the use of the robot <NUM> is not limited to industrial use. The robot <NUM> comprises a base unit <NUM> and an articulated arm <NUM>.

The base unit <NUM> includes a base <NUM>, a rotating unit <NUM>, and an actuator <NUM>. The base <NUM> is fixed to a floor surface or the like of the work area. The base <NUM> may be fixed on a moving body such as an automated guided vehicle (AGV). The rotating unit <NUM> is attached to the base <NUM> to rotate about an axis Ax1 (first axis).

In the following description of the structure of the robot <NUM>, "upper" and "lower" are used to indicate the arrangement relationship. The "upper" and "lower" mean "upper" and "lower" in a state where the axis Ax1 is vertical and the rotating unit <NUM> is positioned above the base <NUM>, but the base unit <NUM> does not necessarily have to be arranged in this manner. For example, the base unit <NUM> may be arranged such that the rotating unit <NUM> is located below the base <NUM>, or the rotating unit <NUM> is located at a side of the base <NUM>. For example, the base <NUM> may be fixed to a ceiling surface of the work area, or the base <NUM> may be fixed to a wall surface of the work area.

The actuator <NUM> includes a motor and a speed reducer, and rotates the rotating unit <NUM> around the axis Ax1.

As shown in <FIG>, the articulated arm <NUM> is of the serial link type and has arms <NUM>, <NUM>, and <NUM>, a tool attachment portion <NUM>, and actuators <NUM>, <NUM>, <NUM>, <NUM>, and <NUM>.

The articulated arm <NUM> is operably coupled to the base unit <NUM>. In an example, an arm <NUM> (first arm) is coupled to the rotating unit <NUM> and swings about an axis Ax2 (second axis) passing through the coupling portion of the arm <NUM> and the rotating unit <NUM>. The axis Ax2 may cross (e.g., cross orthogonally) the axis Ax1. Here, "cross" includes a relationship of skew lines such as a so-called three-dimensional crossing. The same applies to the following description.

An arm <NUM> (second arm) is coupled to a tip portion of the arm <NUM> and swings about an axis Ax3 (third axis) through a coupling portion of the arm <NUM> and the arm <NUM>. The axis Ax3 may be parallel to the axis Ax2.

The arm <NUM> has an arm base <NUM> and a rotating arm <NUM>. The arm base <NUM> is coupled to a tip portion of the arm <NUM> and swings around the axis Ax3. The rotating arm <NUM> is coupled to a tip portion of the arm base <NUM> and extends from the arm base <NUM> along an axis Ax4 that crosses (e.g., cross orthogonally) the axis Ax3 and rotates about the axis Ax4.

An arm <NUM> is coupled to a tip portion of the arm <NUM> and rotates about an axis Ax4 along the arm <NUM> and swings about an axis Ax5 that crosses (e.g., cross orthogonally) the axis Ax4. For example, the arm <NUM> is coupled to a tip portion of the rotating arm <NUM> and swings about the axis Ax5 through a coupling portion of the arm <NUM> and the rotating arm <NUM>.

The tool attachment portion <NUM> is provided at a tip portion of the arm <NUM>. A tool (not shown) for work is attached to the tool attachment portion <NUM>. The tool attachment portion <NUM> rotates about an axis Ax6 along the arm <NUM> across the axis Ax5. Specific examples of the tool include a suction nozzle for sucking a workpiece, a hand for gripping a workpiece, a welding torch, a screw fastening tool (for example, an electric driver), and a polishing tool (for example, a grinder).

Each of the actuators <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> includes, for example, a motor and a speed reducer, similar to the actuator <NUM>, to drive the articulated arm <NUM>. For example, the actuator <NUM> swings the arm <NUM> about the axis Ax2, the actuator <NUM> swings the arm <NUM> about the axis Ax3, the actuator <NUM> rotates the arm <NUM> about the axis Ax4, the actuator <NUM> swings the arm <NUM> about the axis Ax5, and the actuator <NUM> rotates the tool attachment portion <NUM> about the axis Ax6.

Next, the structure of the rotating unit <NUM> will be described in more detail. The rotating unit <NUM> has a rotating base <NUM> (rotating portion), an arm connector <NUM>, and a rib <NUM>. The rotating base <NUM> is made of, for example, a metal material, and is mounted on the base <NUM> via the actuator <NUM> so as to rotate around the axis Ax1.

As shown in <FIG>, the actuator <NUM> has a body <NUM> and an output shaft <NUM>. The output shaft <NUM> protrudes from the body <NUM> and the actuator <NUM> rotates the output shaft <NUM> relative to the body <NUM>. The body <NUM> comprises a motor <NUM> of the rotary type and a speed reducer <NUM>. The speed reducer <NUM> (or a transmitter) reduces the rotation speed of the motor <NUM> and transmits it to the output shaft <NUM>.

The actuator <NUM> is provided in (or mounted on) the rotating unit <NUM>. That the actuator <NUM> is provided in the rotating unit <NUM> means that the body <NUM> is attached to the rotating unit <NUM>. For example, the body <NUM> is attached to the rotating unit <NUM> with the output shaft <NUM> facing vertically downward along the axis Ax1. The output shaft <NUM> passes through the rotating unit <NUM> and is attached to the base <NUM>.

In the example of <FIG>, the body <NUM> is disposed directly above the output shaft <NUM>, but is not necessarily limited thereto. In a non-claimed example, the body <NUM> may be attached to the rotating base <NUM> at an eccentric position with respect to the output shaft <NUM> (with respect to the axis Ax1) (see <FIG>).

As shown in <FIG> and <FIG>, the rotating base <NUM> may have an actuator housing <NUM> that opens upward to receive the actuator <NUM>. The body <NUM> is accommodated within the actuator housing <NUM> and is fixed to the bottom of the actuator housing <NUM>.

As shown in <FIG>, the arm connector <NUM> is provided in (or located at) a first portion P1 of the rotating base <NUM> away from the actuator <NUM>. For example, the first portion P1 is separated from the actuator <NUM> in one direction crossing (e.g., cross orthogonally) the axis Ax2 in a horizontal plane. Hereinafter, for convenience of description, the one direction is referred to as "front", and a direction opposite to the one direction is referred to as "rear".

For example, the first portion P1 is a portion of the circumference of the actuator housing <NUM> located in front of the actuator <NUM>. The arm connector <NUM> is integrally formed with the rotating base <NUM> by, for example, a metal material, and protrudes upward from the first portion P1. The arm connector <NUM> has main surfaces <NUM> and <NUM> perpendicular to the axis Ax2. The main surfaces <NUM> and <NUM> are opposite to each other.

The arm <NUM> is connected to the arm connector <NUM> to swing around the axis Ax2. The arm <NUM> overlaps one side (e.g., the main surface <NUM> side) of the arm connector <NUM> along the axis Ax2. The actuator <NUM> is fixed to the main surface <NUM> side of the arm connector <NUM>, and the arm <NUM> is connected to the arm connector <NUM> via the actuator <NUM>.

The rib <NUM> (first rib) straddles the actuator <NUM> and connects the arm connector <NUM> to a second portion P2 of the rotating base <NUM>. For example, the rib <NUM> partially surrounds the actuator <NUM> and connects the arm connector <NUM> to the second portion P1. The rib <NUM> may straddle the actuator <NUM> in a plane including the axis Ax1. The actuator <NUM> is located between the first portion P1 and the second portion P2 of the rotating base <NUM> such that the second portion P2 sandwiches the actuator <NUM> with the first portion P1. For example, the second portion P2 is a portion of a circumference of the actuator housing <NUM> located behind the actuator <NUM>. The rib <NUM> is connected to a rear portion of the arm connector <NUM> and the second portion P2 of the rotating base <NUM> via vertically above the actuator <NUM>. The rib <NUM> is provided outside the operation region MR of the arm <NUM> around the axis Ax2.

As shown in <FIG>, an undercut 151b is formed on a lower surface 151a of the rib <NUM> so as to be inclined or curved away from the actuator <NUM> toward the first portion P1 from the second portion P2. This reduces the weight of the rib <NUM>. The undercut 151b does not necessarily have to be formed over the entire width of the rib <NUM>. In the examples of <FIG>, the undercut 151b is not formed in a part of the rib <NUM> facing the operation region MR (hereinafter, referred to as an "outer part"). The outer portion protrudes downward from the undercut 151b.

When at least a part of the actuator <NUM> is located between the first portion P1 and the second portion P2, it can be said that the actuator <NUM> is located between the first portion P1 and the first portion P2, and the rib <NUM> is straddling the actuator <NUM>. For example, as shown in <FIG>, even when the body <NUM> is not vertically above the output shaft <NUM>, at least the output shaft <NUM> is located between the first portion P1 and the second portion P2, so that the second portion P2 sandwiches the actuator <NUM> with the first portion P1, and the rib <NUM> is straddling the actuator <NUM>. In the configuration of <FIG>, the rotation of an output shaft <NUM> of the motor <NUM> is transmitted to an input shaft <NUM> of the speed reducer <NUM> via transmission elements <NUM> and <NUM> such as gears, and the output shaft <NUM> rotates according to the rotation of the input shaft <NUM>.

The rib <NUM> may be detachable from the arm connector <NUM> and the rotating base <NUM>. Detachable means that attachment and detachment can be repeated without destruction of the connection portion. For example, the rib <NUM> is a separate member from the rotating base <NUM>, and the rotating unit <NUM> further includes one or more fastening members <NUM> (e.g., bolts or nuts) for removably attaching the rib <NUM> to the second portion P2 and one or more fastening members <NUM> (e.g., bolts or nuts) for removably attaching the rib <NUM> to the arm connector <NUM>. The rib <NUM> increases the stiffness of the arm connector <NUM>.

The rotating unit <NUM> may further comprise a rib <NUM> (second rib). The rib <NUM> is connected to the rotating base <NUM> and the rib <NUM> at a position where the rib <NUM> is located between the rib <NUM> and the operation region MR of the arm <NUM>. The rib <NUM> is connected to a portion of a circumference of the actuator housing <NUM> (hereinafter, referred to as a "third portion P3"), and the rib <NUM>. The third portion P3 and the operation region MR sandwiches the rib <NUM>.

The rib <NUM> may be fixed to the rib <NUM> and may be detachable from the rotating base <NUM>. For example, the rotating unit <NUM> comprises a rib unit <NUM> separated from the rotating base <NUM> and detachable from the rotating base <NUM>, and the rib unit <NUM> includes the ribs <NUM> and <NUM>. In addition to the fastening members <NUM> and <NUM> described above, the rotating unit <NUM> may further include one or more fastening members <NUM> (e.g., bolts or nuts) that removably fasten the rib <NUM> to the third portion P3. The rib <NUM> further increases the stiffness of the arm connector <NUM>. As the undercut 151b is formed on the lower surface 151a of the rib <NUM>, an undercut 152b is formed on the lower surface 152a of the rib <NUM> so as to be inclined or curved away from the actuator <NUM> toward the rib <NUM>. This reduces the weight of the rib <NUM>.

The rotating unit <NUM> may further include a rib <NUM> connected to the rotating base <NUM> and the arm connector <NUM> at a position sandwiching the actuator <NUM> with the rib <NUM>. The rib <NUM> further increases the stiffness of the arm connector <NUM>. The rib <NUM> may be curved to at least partially surround the actuator <NUM>.

The rotating unit <NUM> may further include a cover <NUM> covering the rotating base <NUM> and the ribs <NUM> and <NUM> (see <FIG>). The cover <NUM> may be made of a metal material or a resin material.

The configurations of the rib unit <NUM> shown in <FIG> are merely examples, and can be appropriately changed. For example, a rib unit 150A shown in <FIG> further includes <NUM> corresponding to the rib <NUM>, a rib <NUM> corresponding to the rib <NUM>, and a thin part <NUM> that covers an opening surrounded by the rib <NUM>, the rib <NUM>, and the periphery of the actuator housing <NUM>. The thin part <NUM> is integrally formed with the rib <NUM> and <NUM>. In the rib unit 150A, the undercut 151b is not formed in the rib <NUM>, and the undercut 152b is not formed in the rib <NUM>. A rib unit 150B shown in <FIG> is a modification of the rib unit 150A where the undercuts 151b and 152b are formed in the ribs <NUM> and <NUM>, respectively. The rib <NUM> corresponds to the rib <NUM>. The rib <NUM> corresponds to the rib <NUM>. In a rib unit 150C shown in <FIG>, the rib <NUM> corresponding to the rib <NUM> does not have the undercut 151b. The rib unit 150C does not have the rib <NUM>. The rib unit 150C has a bracket <NUM> instead of the rib <NUM>. The bracket <NUM> protrudes from a lower portion of the rib <NUM> in a direction opposite to the operation region MR, and is connected to the periphery of the actuator housing <NUM>. Although not shown in <FIG>, the rib units 150A, 150B, and 150C may also be removably fastened to the arm connector <NUM> and the rotating base <NUM> by one or more fastening members. For example, the bracket <NUM> is removably attached to the third portion P3 by one or more fastening members (not shown).

Next, structure of the arm <NUM> will be described in more detail. The arm <NUM> has a proximal portion <NUM>, a tip portion <NUM>, and an outer shell <NUM>. The proximal portion <NUM> is made of, for example, a metal material, and is connected to the arm connector <NUM>. The tip portion <NUM> is made of, for example, a metal material. The arm <NUM> is connected to the tip portion <NUM>.

The outer shell <NUM> is a hollow portion extending along an axis crossing (e.g., cross orthogonally) the axes Ax2 and Ax3 and connecting the proximal portion <NUM> and the tip portion <NUM>. The outer shell <NUM> includes a main body <NUM> having a plurality of openings and a cover <NUM> covering the main body <NUM>. The main body <NUM> is integrally formed with the proximal portion <NUM> and the tip portion <NUM> by, for example, a metal material.

The cover <NUM> may be made of a metal material or a resin material. As shown in <FIG>, the cover <NUM> is thinner than the main body <NUM>, and constitutes a plurality of thin parts 215a for covering the plurality of openings, respectively. As shown in <FIG>, the thin parts 215a may be integrated with the main body <NUM>.

As shown in <FIG>, the main body <NUM> includes frames <NUM> and <NUM> and one or more connection frames <NUM>. The frame <NUM> (first frame) and the frame <NUM> (second frame) face each other across a virtual plane VP1 including the axes Ax2 and Ax3, and connect the proximal portion <NUM> and the tip portion <NUM>, respectively. With the tip portion <NUM> positioned vertically above the proximal portion <NUM>, the frame <NUM> faces forward and the frame <NUM> faces rearward.

The aforementioned plurality of openings may include an opening <NUM> formed in the frame <NUM> and may include an opening <NUM> formed in the frame <NUM>. The aforementioned plurality of openings may include both of the openings <NUM> and <NUM>.

The one or more connection frames <NUM> connect the frame <NUM> and the frame <NUM> between the axis Ax2 and the axis Ax3. The one or more connection frames <NUM> may include a brace frame that is oblique to the frame <NUM> and the frame <NUM>. The one or more connection frames <NUM> may include a proximal connection frame connected to the frame <NUM>, the frame <NUM>, and the proximal portion <NUM>. The one or more connection frames <NUM> may include a tip connection frame connected to the frame <NUM>, the frame <NUM>, and the tip portion <NUM>. The one or more connection frames <NUM> may include two connection frames that intersect each other.

The aforementioned plurality of openings may include an opening that is at least partially surrounded by the one or more connection frames <NUM>. The main body <NUM> may be configured such that the connection frame <NUM> does not pass through a region overlapping the arm <NUM> and a region overlapping the arm connector <NUM>.

Hereinafter, the configuration of the one or more connection frames <NUM> will be exemplified in more detail. As shown in <FIG> and <FIG>, the main body <NUM> has a plurality of connection frames <NUM>, <NUM>, and <NUM> facing the arm connector <NUM> along the axis Ax2 and connection frames <NUM>, <NUM>, <NUM>, and <NUM> facing away from the arm connector <NUM> along the axis Ax2.

A connection frame <NUM> is connected to the frame <NUM>, the frame <NUM>, and the tip portion <NUM>. Therefore, the connection frame <NUM> corresponds to the tip connection frame. The connection frame <NUM> obliquely intersects the frame <NUM> and the frame <NUM>. Therefore, the connection frame <NUM> also corresponds to the brace frame.

The connection frame <NUM> forms two openings <NUM> and <NUM>. An opening <NUM> is surrounded by the tip portion <NUM>, the frame <NUM>, and the connection frame <NUM>. An opening <NUM> is surrounded by the tip portion <NUM>, the frame <NUM>, and the connection frame <NUM>. The connection portion between the connection frame <NUM> and the tip portion <NUM> is located closer to the frame <NUM> between the frame <NUM> and the frame <NUM>. Thus, the opening <NUM> is larger than the opening <NUM>. At least a portion of the opening <NUM> is located in a region MR2 of the arm <NUM> overlapping the arm <NUM>. The connection frame <NUM> is inclined away from the axis Ax3 toward the frame <NUM> from the frame <NUM>. This further increases the size of the opening <NUM>, which contributes to a reduction in the weight of the arm <NUM> and ensures a large movable range of the arm <NUM> with respect to the arm <NUM>.

A connection frame <NUM> is connected to the frame <NUM>, the frame <NUM>, and the proximal portion <NUM>. Therefore, the connection frame <NUM> corresponds to the proximal connection frame. The connection frame <NUM> obliquely intersects the frame <NUM> and the frame <NUM>. Therefore, the connection frame <NUM> also corresponds to the brace frame.

The connection frame <NUM> forms two openings <NUM> and <NUM>. An opening <NUM> is surrounded by the proximal portion <NUM>, the frame <NUM>, and the connection frame <NUM>. An opening <NUM> is surrounded by the proximal portion <NUM>, the frame <NUM>, and the connection frame <NUM>. The connection portion between the connection frame <NUM> and the proximal portion <NUM> is located closer to the frame <NUM> between the frame <NUM> and the frame <NUM>. Thus, the opening <NUM> is larger than the opening <NUM>.

At least a portion of the opening <NUM> is located in a region of the arm <NUM> that overlaps the arm connector <NUM>. The connection frame <NUM> is inclined away from the axis Ax2 toward the frame <NUM> from the frame <NUM>. This further increases the size of the opening <NUM>, which contributes to a reduction in the weight of the arm <NUM> and ensures a large movable range of the arm <NUM> with respect to the arm connector <NUM>.

The connection frame <NUM> obliquely crosses the frame <NUM> and the frame <NUM> between the connection frame <NUM> and the connection frame <NUM>. Therefore, the connection frame <NUM> corresponds to the brace frame. The connection frame <NUM> intersects the connection frame <NUM> in the vicinity of the frame <NUM>.

The connection frame <NUM> further forms two openings <NUM> and <NUM>. An opening <NUM> is surrounded by the connection frame <NUM>, the frame <NUM>, the connection frame <NUM>, and the frame <NUM>. An opening <NUM> is surrounded by the connection frame <NUM>, the frame <NUM>, the connection frame <NUM>, and the frame <NUM>.

A connection frame <NUM> is connected to the frame <NUM>, the frame <NUM>, and the tip portion <NUM>. Therefore, the connection frame <NUM> corresponds to the tip connection frame. The connection frame <NUM> is bent to protrude toward the tip portion <NUM> and connected to the tip portion <NUM>. The connection frame <NUM> forms two openings <NUM> and <NUM>. An opening <NUM> is surrounded by the tip portion <NUM>, the frame <NUM>, and the connection frame <NUM>. An opening <NUM> is surrounded by the tip portion <NUM>, the frame <NUM>, and the connection frame <NUM>.

The connection frame <NUM> is located closest to the proximal portion <NUM> among the connection frames <NUM>, <NUM>, <NUM>, and <NUM>. The connection frame <NUM> obliquely intersects the frame <NUM> and the frame <NUM>. Therefore, the connection frame <NUM> corresponds to the brace frame.

Since the connection frame <NUM> is not connected to the proximal portion <NUM>, one opening <NUM> is formed between the connection frame <NUM> and the proximal portion <NUM>. The opening <NUM> is surrounded by the proximal portion <NUM>, the frame <NUM>, the connection frame <NUM>, and the frame <NUM>. The opening <NUM> can be used for cable wiring and the like.

The connection frame <NUM> obliquely crosses the frame <NUM> and the frame <NUM> between the connection frame <NUM> and the connection frame <NUM>. Therefore, the connection frame <NUM> corresponds to the brace frame. The connection frame <NUM> intersects the connection frame <NUM> in the vicinity of the frame <NUM>, and intersects the connection frame <NUM> in the vicinity of the frame <NUM>.

The connection frame <NUM> is located between the connection frame <NUM> and the connection frame <NUM>. One end of the connection frame <NUM> is connected to the frame <NUM>. The other end of the connection frame <NUM> is connected to the connection frame <NUM> and is connected to the frame <NUM> via the connection frame <NUM>.

The connection frames <NUM> and <NUM> form three openings <NUM>, <NUM>, and <NUM>. An opening <NUM> is surrounded by the connection frame <NUM>, the connection frame <NUM>, and the frame <NUM>. An opening <NUM> is surrounded by the connection frame <NUM>, the frame <NUM>, the connection frame <NUM>, and the connection frame <NUM>. An opening <NUM> is surrounded by the connection frame <NUM>, the frame <NUM>, and the connection frame <NUM>.

As described above, the robot <NUM> includes the base unit <NUM> and the articulated arm <NUM>. The base unit <NUM> includes the rotating base <NUM>, the actuator <NUM> provided on the rotating base <NUM> to rotate the rotating base <NUM> about the axis Ax1, and the arm connector <NUM> provided on the first portion P1 of the rotating base <NUM> away from the actuator <NUM>. The articulated arm <NUM> has the arm <NUM> connected to the arm connector <NUM> to swing about the axis Ax2. The base unit <NUM> further comprises the rib <NUM> that connects the arm connector <NUM> and the second portion P2 of the rotating base <NUM> straddling the actuator <NUM>.

To downsize the base unit <NUM> of the robot <NUM>, the arm connector <NUM> and the actuator <NUM> need to be brought into close proximity. However, downsizing the arm connector <NUM> due to its proximity to the actuator <NUM> reduces stiffness. In contrast, in the robot <NUM>, the base unit <NUM> further includes the rib <NUM>, and the rib <NUM> strides the actuator <NUM> to connect the arm connector <NUM> and the rotating base <NUM>. With this structure, it is possible to bring the arm connector <NUM> and the actuator <NUM> close to each other while maintaining the stiffness of the arm connector <NUM>, thereby downsizing the base unit <NUM>. Therefore, it is effective for downsizing.

The rib <NUM> may be detachable from the arm connector <NUM> and the rotating base <NUM>. In this case, both downsizing and maintainability are achieved.

The axis Ax2 may cross the axis Ax1, the arm <NUM> may overlap one side of the arm connector <NUM> along the axis Ax2, and the rib <NUM> may be provided outside an operation region of the arm <NUM> around the axis Ax2. In some examples, the arm <NUM> may occupy the operation region while swinging about the axis Ax2, and the rib <NUM> may be located adjacent to the operation region of the arm <NUM>. In this case, both the wide movable range of the arm <NUM> and the stiffness of the arm connector <NUM> are achieved.

The robot <NUM> may further include the rib <NUM> connected to the rotating base <NUM> and the rib <NUM> at a position at which the rib <NUM> is interposed between the rib <NUM> and the operation region MR of the arm <NUM>. In this case, it is possible to further improve the stiffness of the arm connector <NUM> while maintaining a wide movable region of the arm <NUM>.

The rib <NUM> may be fixed to the rib <NUM> and may be detachable from the rotating base <NUM>. The rib <NUM> may be removably connected to the rotating base <NUM>. In this case, both downsizing and maintainability can be achieved.

The arm <NUM> may have the proximal portion <NUM> connected to the arm connector <NUM>, the tip portion <NUM>, and the hollow outer shell <NUM>. The outer shell <NUM> may connect the proximal portion <NUM> and the tip portion <NUM>. The outer shell <NUM> may include the main body <NUM> having a plurality of openings and the thin parts 215a covering the openings, respectively. In this case, the weight of the arm <NUM> can be reduced while maintaining the stiffness of the arm <NUM>. Further, the reduction in weight of the arm <NUM> enables further downsizing of the base unit <NUM>. Therefore, it is effective for further downsizing.

The articulated arm <NUM> further may have the arm <NUM> connected to the tip portion <NUM> to swing about the axis Ax3 parallel to the axis Ax2, and the main body <NUM> may include the frame <NUM>, the frame <NUM>, and the one or more connection frames <NUM>. The frame <NUM> and the frame <NUM> face each other across a virtual plane VP1 including the axis Ax2 and the axis Ax3, and connect the tip portion <NUM> and the proximal portion <NUM>, respectively. The one or more connection frames <NUM> connect the frame <NUM> and the frame <NUM> between the axis Ax2 and the axis Ax3. In this case, the stiffness of the arm <NUM> in the swing direction around the axis Ax2 can be freely adjusted by the number and arrangement of the one or more connection frames <NUM>.

The one or more connection frames <NUM> may include the frames <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> (the brace frame) that is oblique to the frame <NUM> and the frame <NUM>. In this case, the stiffness of the arm <NUM> in the swing direction around the axis Ax2 is improved.

The one or more connection frames <NUM> may include the connection frame <NUM> (proximal connection frame) connected to the frame <NUM>, the frame <NUM>, and the proximal portion <NUM>. In this case, the stiffness of the arm <NUM> at the tip portion <NUM> where the moment of the arm <NUM> is concentrated is improved.

The one or more connection frames <NUM> may include the connection frames <NUM> and <NUM> (tip connection frame) connected to the frame <NUM>, the frame <NUM>, and the tip portion <NUM>. In this case, the stiffness of the arm <NUM> at the tip portion <NUM> where the moment of the arm <NUM> is concentrated is improved.

The one or more connection frames <NUM> may include two connection frames <NUM> that intersect each other. In this case, the stiffness of the arm <NUM> in the swing direction around the axis Ax2 is further improved.

The main body <NUM> may be configured such that the connection frame <NUM> does not pass through a region overlapping the arm <NUM> and a region overlapping the arm connector <NUM>. In this case, both the wide movable range of the arm <NUM> and the stiffness of the arm <NUM> are achieved.

Claim 1:
A robot (<NUM>) comprising:
an articulated arm (<NUM>); and
a base unit (<NUM>) to which the articulated arm (<NUM>) is operably coupled,
the base unit (<NUM>) comprising:
a base (<NUM>);
a rotating portion (<NUM>);
an actuator (<NUM>) configured to rotate the rotating portion (<NUM>) about a first axis (Ax1), wherein the actuator (<NUM>) comprises a body (<NUM>) attached to the rotating portion (<NUM>) and an output shaft (<NUM>) protruding from the body (<NUM>), wherein the body (<NUM>) comprises a motor (<NUM>) and a speed reducer (<NUM>) configured to transmit a rotation of the motor (<NUM>) to the output shaft (<NUM>) to rotate the output shaft (<NUM>) about the first axis (Ax1), wherein the output shaft (<NUM>), the speed reducer (<NUM>), and the motor (<NUM>) are aligned along the first axis (Ax1), and wherein the output shaft (<NUM>) passes through the rotating portion (<NUM>) and is attached to the base (<NUM>);
an arm connector (<NUM>) located at a first portion (P1) of the rotating portion (<NUM>), wherein the articulated arm (<NUM>) is connected to the arm connector (<NUM>) to swing about a second axis (Ax2); and
a rib (<NUM>) straddling the actuator (<NUM>) in a plane including the first axis (Ax1) and connecting the arm connector (<NUM>) to a second portion (P2) of the rotating portion (<NUM>), wherein the actuator (<NUM>) is located between the first portion (P1) and the second portion (P2) of the rotating portion (<NUM>).