Jig supporting reduction gear of robot and method of replacing reduction gear using jig

There is a demand for further improving efficiency of a task of replacing the reduction gear of the robot. A jig configured to support a reduction gear connecting a first element and a second element of a robot to be enabled to perform a speed reduction operation on each other, when the second element is separated from the first element includes a fixed portion removably mounted to the first element or the second element, a movable portion rotationally or translationally movably mounted to the fixed portion, and a support mounted to the movable portion and configured to suspend and support the reduction gear in a gravity direction.

RELATED APPLICATIONS

The present application claims priority to Japanese Application Number 2019-072307, filed Apr. 4, 2019, the disclosure of which is hereby incorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a jig supporting a reduction gear of a robot and a method of replacing a reduction gear by using a jig.

2. Description of the Related Art

A jig is known that supports a reduction gear provided in a robot to replace the reduction gear (e.g., JP 2013-78815 A). There is a demand for further improving efficiency of a work of replacing the reduction gear of the robot.

SUMMARY OF THE INVENTION

In an aspect of the present disclosure, a jig is configured to support a reduction gear when a second element of a robot is separated from a first element of the robot, wherein the reduction gear is configured to connect the first element and the second element each other so as to perform a speed-reduction operation, wherein the jig comprises a fixed portion detachably attached to the first element or the second element, a movable portion attached to the fixed portion so as to be rotationally or linearly movable, and a support attached to the movable portion and configured to suspend the reduction gear in a gravity direction to support the reduction gear.

In another aspect of the present disclosure, a method of replacing a reduction gear using the above-described jig includes fixing the support to the reduction gear mounted to one of the first element and the second element separated from each other, removing the reduction gear from the one of the first element and the second element and suspending the reduction gear in the gravity direction by the support to support the reduction gear, and moving the reduction gear supported by the support away from the one of the first element and the second element by moving the movable portion with respect to the fixed portion.

According to the present disclosure, an operator can move the reduction gear suspended from the support closer to and away from an attachment portion in the robot, by moving the movable portion. Due to this, it is not necessary to move the reduction gear by a heavy machine, whereby it is possible to improve efficiency of a work of replacing the reduction gear.

DETAILED DESCRIPTION

Embodiments of the present disclosure will now be described in detail with reference to the drawings. Note that, in the various embodiments described below, similar elements are denoted by the same reference numerals, and redundant description thereof will be omitted. Further, in the following description, upward and downward directions may refer to the upward and downward directions in the gravity direction (i.e., the vertical direction).

First, with reference toFIG.1toFIG.6, a jig10according to an embodiment will be described. The jig10is used for replacing a reduction gear202built in a robot200. In the present embodiment, the robot200is a vertical articulated robot, and includes a base204, a rotary barrel206, a lower arm208, an upper arm210, and a wrist220. The base204is fixed on a floor of a Work cell. The rotary barrel206is provided at the base204to as to be rotatable about an axis A1. The axis A1is parallel to a vertical direction, for example.

The lower arm208includes a proximal end part212and a distal end part214opposite the proximal end part212, wherein the proximal end part212is connected to the rotary barrel206so as to be rotatable about an axis A2. The axis A2is orthogonal to the axis A1. The upper arm210includes a proximal end part216and a distal end part218opposite the proximal end part216, wherein the proximal end part216is connected to the distal end part214of the lower arm208so as to be rotatable about an axis A3. The axis A3is parallel to the axis A2.

The wrist220is rotatably provided at the distal end part218of the upper arm210, and an end effector (welding torch, robot hand, paint applicator, etc., not illustrated) configured to perform a work (welding, handling, painting, etc.) on a workpiece is detachably attached to a distal end part of the wrist. The wrist220rotatably supports the end effector.

A servomotor (not illustrated) and a reduction gear (e.g., the reduction gear202) are built in each constituent element (i.e., the base204, rotary barrel206, lower arm208, upper arm210, wrist220) of the robot200. The reduction gear connects a first constituent element and a second constituent element of the constituent elements of the robot200, each other, so as to perform a speed-reduction operation therebetween. The servomotor rotates the first and second elements relative to each other via the reduction gear.

A cable222is wired on the robot200. Specifically, the cable222is led out from the rotary barrel206, and a connector (not illustrated) provided at a distal end of the cable222is connected to a connector (not illustrated) provided in the proximal end part216of the upper arm210. The cable222includes e.g. a signal line transmitting a signal to a servomotor for driving the wrist220or the end effector attached to the wrist220. The cable222is restrained by fittings224provided at the vicinity of each joint.

The reduction gear202connects the lower arm208and the upper arm210each other so as to perform a speed-reduction operation therebetween. Specifically, the reduction gear202is interposed between the distal end part214of the lower arm208and the proximal end part216of the upper arm210, wherein an input side of the reduction gear202is mounted to the distal end part214of the lower arm208by a fastener (not illustrated) such as a bolt, while an output side of the reduction gear202is mounted to the proximal end part216of the upper arm210with a fastener (not illustrated) such as a bolt.

In a state in which the lower arm208and the upper arm210are connected to each other via the reduction gear202, the reduction gear202is received in a hole228(FIG.3) formed at the proximal end part216of the upper arm210, and in a hole230(FIG.1andFIG.3) formed at the distal end part214of the lower arm208. The holes228and230are circular holes, and disposed to be concentric with each other with respect to the axis A3when the lower arm208and the upper arm210are connected.

The jig10suspends the reduction gear202therefrom to support it, and facilitates a replacement of the reduction gear202by moving the reduction gear202being suspended. The jig10includes a fixed portion12, a movable portion14, and a support16. The fixed portion12is detachably attached to the upper arm210. More specifically, the fixed portion12is attached to the proximal end part216of the upper arm210by a plurality of fasteners (e.g., bolts)18.

As illustrated inFIG.4, the fixed portion12includes a flat-plate shaped first part20and a flat-plate shaped second part22extending substantially orthogonally to the first part20. A circular recess20aand a plurality of through holes20bare formed in the first part20. The recess20ais formed to be recessed inward from an end face20cof the first part20, and has a radius substantially the same as the hole228formed in the proximal end part216of the upper arm210.

The through holes20bare disposed along a wall surface20adefining the recess20a. In the present embodiment, the through holes20bare disposed so as to align along the wall surface20ain two rows having an inner-row closer to the wall surface20aand an outer-row farther away from the wall surface20athan the inner row.

The second part22includes an inner surface22athat faces toward the first part20and an outer surface22bopposite the inner surface22a, wherein fittings24and26are fixed to the outer surface22b. The fitting24defines a bottomed hole28when fixed to the outer surface22b. The fitting26defines a through hole30aligned with the hole28in a direction of an axis A4when fixed to the outer surface22b.

In the present embodiment, the plurality of fasteners18are inserted into the through holes20bof the inner-row formed in the first part20and fastened to fastening holes (specifically, tap holes)232formed in the proximal end part216of the upper arm210, whereby the fixed portion12is detachably fixed to the proximal end part216of the upper arm210.

Note that the fixed portion12is configured to be attached to and detached from the proximal end part216of the upper arm210in a state in which the lower arm208and the upper arm210are connected to each other. Thus, the first part20of the fixed portion12is configured to be inserted into a gap formed between the distal end part214of the lower arm208and the proximal end part216of the upper arm210when the lower arm208and the upper arm210are connected to each other (in other words, the first part20has a smaller thickness than the gap).

The fastening holes232are used to fasten a stopper (not illustrated) for restricting rotation of the upper arm210with respect to the lower arm208, and formed in the proximal end part216so as to align around the hole228(or around the axis A3) at substantially equal intervals. The through holes20bof the inner-row and the outer-row in the first part20are disposed to align at the same intervals as the fastening holes232.

As described above, in the present embodiment, the fixed portion12is fixed to the upper arm210by making use of the fastening holes232formed at the robot200for a predetermined application (e.g., for fastening the stopper). Note that, if the jig10is mounted to a robot of a type different from the robot200, the jig10can be mounted to the different type of robot by using the through holes20bof the outer-row in the first part20for fastening the fasteners18. By selecting the inner-row and the outer-row of the through holes20bin this way, it is possible to apply the jig10to different types of robots.

The movable portion14is attached to the fixed portion12so as to be rotationally and linearly movable. Specifically, the movable portion14includes a rotating member32and a linear-motion member34. The rotating member32is a substantially L-shaped rod member having a circular cross section, and is attached to the fixed portion12so as to be rotatable about the axis A4. The axis A4is substantially orthogonal to the rotational axis A3of the upper arm210.

The rotating member32includes a first arm32aextending linearly along the axis A4and a second arm32bextending linearly in a direction orthogonal to the axis A4. The first arm32ais rotatably received in the hole28in the fitting24and the through hole30in the fitting26, and attached to the fixed portion12via the fittings24and26so as to be rotatable. A pair of stoppers36are provided at the second arm32b. These stoppers36are spaced apart from each other and protrude outward from the second arm32b.

The linear-motion member34is provided on the second arm32bso as to be linearly movable. Specifically, as illustrated inFIG.4andFIG.5, the linear-motion member34includes a main body38, rolling elements40rotatably provided inside the main body38, and a suspension tool42fixed to a lower side of the main body38. The main body38is a hollow member having a cylindrical inner circumferential surface38a.

The rolling elements40are e.g. balls (or rollers), and rotatably provided at the inner circumferential surface38aof the main body38so as to protrude inward from the inner circumferential surface38a. The second arm32bis inserted into the main body38so as to contact each rolling element40, whereby the linear-motion member34can be linearly moved along the second arm32b.

Movement of the linear-motion member34with respect to the second arm32bis restricted by the pair of stoppers36provided at the second arm32b. The stoppers36prevent the linear-motion member34from moving to the first arm32aor dropping off from a distal end of the second arm32b. The suspension tool42is so-called an eye bolt or the like, and provided so as to protrude downward from the lower side of the main body38.

The support16is attached to the movable portion14, and suspends the reduction gear202therefrom in the gravity direction to support it. Specifically, the support16includes a suspending device44and a mounting member46. The suspending device44is a device such as so-called a chain block, and includes a suspending wire48, a housing section50, and hooks52and54. The suspending wire48is a high tensile wire member that can withstand the gravitational force of the reduction gear202, such as a metal chain or a high tensile rope.

The housing section50is hollow, and the suspending wire48is wound up to be housed in the housing section50. Specifically, a winding core56is rotatably provided in the housing section50, and the suspending wire48is wound around the winding core56. At one end of the winding core56, a handle56aprotruding outward of the housing section50is provided, and the operator can rotate the winding core56by gripping and rotating the handle56a.

If the operator rotates the handle56ain one direction from the state illustrated inFIG.4, the suspending wire48, which has been wound up around the winding core56, is pulled out from the housing section50so as to downwardly move the hook54suspended from a distal end of the suspending wire48, as illustrated inFIG.6. On the other hand, if the operator rotates the handle56ain the other direction from the state illustrated inFIG.6, the suspending wire48is wound around the winding core56to move the hook54upward.

The hook52is fixedly provided on an outer circumferential surface of the housing section50. The hook52is a substantially C-shaped member formed of e.g. a metal, and suspended from the suspension tool42. On the other hand, the hook54is fixedly provided at the distal end of the suspending wire48. Similar to the hook52, the hook54is a substantially C-shaped member formed of e.g. a metal.

The mounting member46includes a first member58, a second member60, and a suspension tool62. The first member58has a substantial L shape, and includes a first arm58aand a second arm58bthat is substantially orthogonal to the first arm58a. The second arm58bextends downward from one end of the first arm58a. The suspension tool62is fixedly provided on a top face of the other end of the first arm58a. The suspension tool62is a so-called eye bolt, and provided so as to protrude upward from the other end of the first arm58a. The suspension tool62is suspended from the hook54.

As illustrated inFIG.2andFIG.4, the second member60is a substantially rectangular flat plate member elongating in a lateral direction. A slot60aand a plurality of fastening holes (such as tap holes)60bare formed in the second member60. The slot60ais elongated in the lateral direction. The fastening holes60bare divided into two rows on an upper side and a lower side of the slot60a, and disposed to align along the slot60a.

The second arm58bof the first member58is fixed to the second member60by a pair of fasteners (such as bolts)64. The pair of fasteners64is inserted into a pair of through holes (not illustrated) formed in the second arm58b, and one of the pair of fasteners64is fastened to the fastening hole60bdisposed on the upper side of the slot60a, while the other one of the pair of fasteners64is fastened to the fastening hole60bdisposed on the lower side of the slot60a. In this way, the first member58and the second member60are firmly fixed to each other. Note that, by changing the pair of fastening holes60bto be fastened by the fasteners64, it is possible to adjust the position of the second member60with respect to the first member58in the lateral direction.

The mounting member46is detachably attached to the reduction gear202. Specifically, as illustrated inFIG.2, a pair of fasteners (such as bolts)66are disposed on both the right and left sides of the second arm58b, and right-side one of the pair of fasteners66is inserted into the slot60a, while the left-side one of the pair of fastener66is inserted into a through hole (not illustrated) formed in the second member60so as to be separate leftward from the slot60a. Then, the pair of fasteners66are fastened, at their distal ends, to a pair of fastening holes (not illustrated) formed in the reduction gear202.

In this way, the mounting member46is firmly fixed to the reduction gear202, and the support16can suspend the reduction gear202in the gravity direction to support the reduction gear202when the reduction gear202is separated away from the upper arm210as illustrated inFIG.3andFIG.4. Note that, since the distance between the pair of fasteners66can be adjusted due to the slot60a, and the mounting member46can be mounted to reduction gears having various diameters and including fastening holes with various pitches.

Next, a method of replacing the reduction gear202of the robot200using the jig10will be described. First, in a state in which the lower arm208and the upper arm210connected to each other, the operator fixes the fixed portion12of the jig10to the proximal end part216of the upper arm210by the fasteners18. Then, the operator removes the fasteners, which have fastened the lower arm208and the reduction gear202together, while suspending the upper arm210by a heavy machine (not illustrated) such as a crane, and separates the lower arm208away from the reduction gear202.

As a result, as illustrated inFIG.1, the upper arm210and the reduction gear202fixed to the proximal end part216of the upper arm210are separated from the lower arm208and suspended by the heavy machine. At this time, the heavy machine may suspend the upper arm210such that the axis A4of the jig10is substantially parallel with the vertical direction.

In this regard, the operator carries out a work of separating the upper arm210from the lower arm208in a state in which the cable222is connected to a connector provided at the proximal end part216. Accordingly, the upper arm210separated from the lower arm208is suspended by the heavy machine at a position away from the lower arm208to the extent that the cable222can be kept connected to the connector.

Then, the operator fixes the mounting member46of the support16to the reduction gear202fixed to the upper arm210by the fasteners66. The operator then removes the fasteners, which have fastened the upper arm210and the reduction gear202together, so as to separate the reduction gear202away from the upper arm210. Thus, the reduction gear202is suspended in the gravity direction and supported by the support16.

Here, when the reduction gear202is suspended from the support16, the center of gravity of the reduction gear202and the suspension tool62of the mounting member46are aligned in the gravity direction. In order to achieve such alignment between the center of gravity of the reduction gear202and the suspension tool62, the first member58is configured to have a substantial L shape.

According to this configuration, when the reduction gear202is suspended from the support16, the reduction gear202can be prevented from inclining with respect to the gravity direction and supported in a stable orientation. Note that, by changing the fastening holes60bto be fastened by the fasteners64to adjust the position of the second member60with respect to the first member58in the lateral direction, it is possible to more effectively prevent the reduction gear202from being inclined with respect to the gravity direction.

Then, the operator moves the reduction gear202supported by the support16away from the upper arm210by moving the movable portion14with respect to the fixed portion12. Specifically, the operator rotates the rotating member32of the movable portion14about the axis A4from the position illustrated inFIG.1andFIG.2to the position illustrated inFIG.3andFIG.4.

Due to this, the support16and the reduction gear202supported by the support16are moved away from the upper arm210in the horizontal direction. In this manner, the rotating member32of the movable portion14rotates with respect to the fixed portion12to move the support16and the reduction gear in the horizontal direction. Note thatFIG.3andFIG.4illustrate an example in which the rotating member32is rotated approximately 180° from the position illustrated inFIG.1andFIG.2.

Here, by linearly moving the linear-motion member34along the second arm32bas necessary, the operator can move the reduction gear202along the second arm32bin the horizontal direction. Specifically, the operator applies a force to the reduction gear202or support16in the horizontal direction, for example. Due to this, the linear-motion member34of the movable portion14linearly moves along the second arm32b, whereby the reduction gear202is moved in the horizontal direction together with the support16.

As described above, the linear-motion member34can linearly move with respect to the fixed portion12to move the support16and the reduction gear202in the horizontal direction. According to this configuration, the operator can adjust the position of the reduction gear202in the horizontal direction as necessary in a case where the operator desires to further move the reduction gear202away from (or toward) the fixed portion12after the rotation of the rotating member32.

After rotating the rotating member32, the operator rotates the handle56aof the suspending device44in one direction from the state illustrated inFIG.4so as to draw the suspending wire48out of the housing section50. As a result, it is possible to downwardly move the mounting member46and the reduction gear202that are suspended from the distal end of the suspending wire48via the hook54, as illustrated inFIG.6. As an example, the operator operates the suspending device44so as to move the reduction gear202downward until it is placed on the floor of the work cell.

The operator then removes the fastener66fixing the mounting member46and the reduction gear202, and removes the mounting member46from the reduction gear202. The operator then fixes a new reduction gear202to the mounting member46by the fastener66. The operator then rotates the handle56aof the suspending device44in the other direction.

By this operation, the suspending wire48is wound around the winding core56, whereby the mounting member46and the new reduction gear202is moved upward from the position illustrated inFIG.6to the position illustrated inFIG.4. Thus, the suspending device44can move the mounting member46and the reduction gear202so as to be reciprocated along the gravity direction. In this way, the new reduction gear202is suspended from the support16in the gravity direction and supported by the support16.

Then, the operator moves the new reduction gear202supported by the support16toward the upper arm210by moving the movable portion14with respect to the fixed portion12. Specifically, the operator rotates the rotating member32of the movable portion14from the position illustrated inFIG.3andFIG.4to the position illustrated inFIG.1andFIG.2.

As a result, the new reduction gear202can be disposed at the proximal end part216of the upper arm210, which is an attachment portion to which the reduction gear202is to be attached. At this time, the operator may move the new reduction gear202in the horizontal direction along the second arm32bvia the linear-motion member34so as to adjust the position of the new reduction gear202, as necessary, in order to position the new reduction gear202at the proximal end part216of the upper arm210.

The operator then fixes the output side of the new reduction gear202to the proximal end part216of the upper arm210by the fasteners, and subsequently, fixes the input side of the new reduction gear202to the distal end part214of the lower arm208. In this way, the operator can replace the reduction gear202using the jig10.

As described above, according to the present embodiment, by moving the movable portion14, the operator can move the reduction gear202suspended from the support16closer to and away from the attachment portion (in this embodiment, the proximal end part216) in the robot200to which the reduction gear is to be attached. According to this configuration, it is not necessary to move the reduction gear202by the heavy machine, the work of replacing the reduction gear202can be made more efficient.

Further, according to the present embodiment, it is possible to move the reduction gear202while being stably suspended and supported by the support16. Thus, the operator can more safely replace the reduction gear202which is a heavy load of a relatively high weight.

Further, the fixed portion12can be attached to and detached from the constituent element of the robot200(in the present embodiment, the upper arm210). According to this configuration, the operator can fix the fixed portion12to the upper arm210by making use of the fastening holes232formed in the robot200for a predetermined application (e.g., for fastening the stopper). Thus, another jig for fixing the jig10is unnecessary, and the operator can easily and quickly attach and detach the fixed portion12to and from the constituent element of the robot200.

Further, in the present embodiment, the fixed portion12is configured to be attachable to and detachable from the upper arm210while the lower arm208and the upper arm210connected to each other. According to this configuration, since the jig10can be mounted to the upper arm210before the upper arm210is suspended by the heavy machine, it is possible to improve the work-efficiency. Further, due to the recess20aformed at the fixed portion12, it is possible to prevent the fixed portion12from interfering with the reduction gear202or a component of the robot200, when attaching the fixed portion12while the lower arm208and the upper arm210are connected to each other.

Further, in the present embodiment, the fixed portion12is fixed to the proximal end part216, which is a part of the upper arm210close to the rotational axis A3(i.e., the reduction gear202) of the upper arm210with respect to the lower arm208. According to this configuration, since the jig10can be disposed close to the reduction gear202, it is possible to miniaturize each component (the movable portion14, the support16) of the jig10.

Further, in the present embodiment, the movable portion14rotates with respect to the fixed portion12by the action of the rotating member32to move the support16in the horizontal direction. According to this configuration, the operator can easily move the reduction gear202of a heavy load, with a relatively small force. Further, in the present embodiment, the movable portion14includes the linear-motion member34in addition to the rotating member32, whereby rotating and linearly moving with respect to the fixed portion12to move the support16in the horizontal direction. According to this configuration, the operator can adjust the position of the reduction gear202more finely, by moving the reduction gear202suspended from the support16in a plurality of directions.

Further, in the present embodiment, by operating the suspending device44, the operator can reciprocatedly move the mounting member46along the gravity direction. According to this configuration, it is possible to expand a range within which the reduction gear202can be moved, and improve the efficiency of the replacement of the reduction gear202.

Next, a jig70according to another embodiment will be described with reference toFIG.7toFIG.9. The jig70includes a fixed portion72, a guide mechanism74, a movable portion76, and a support16. The fixed portion72is detachably attached to the proximal end part216of the upper arm210, using a plurality of fasteners18.

As illustrated inFIG.8, the fixed portion72is a flat plate member bent in a substantial L shape, and includes a first part78and a second part80that is substantially orthogonal to the first part78. The first part78is disposed to extend upward from the proximal end part216, and formed with a circular recess78aand a plurality of through holes78b. The recess78ais formed at a lower end of the first part78, and has substantially the same radius as the hole228formed in the proximal end part216of the upper arm210.

The through holes78bare disposed along a wall surface78adefining the recess78a. In the present embodiment, the through holes78bare disposed so as to align along the wall surface78ain two rows having an inner-row closer to the wall surface78aand an outer-row farther away from the wall surface78athan the inner-row. The second part80includes an inner surface80afacing toward the first part78and an outer surface80bopposite the inner surface80a.

In the present embodiment, the plurality of fasteners18are inserted into the through holes78bof the inner-row formed in the first part78, and fastened to the fastening holes232formed in the proximal end part216of the upper arm210, whereby the fixed portion72is detachably fixed to the proximal end part216of the upper arm210.

Similar to above-described the fixed portion12, the fixed portion72is configured to be attached to and detached from the proximal end part216of the upper arm210while the lower arm208and the upper arm210are connected to each other. Accordingly, the first part78. of the fixed portion72has a thickness smaller than a gap formed between the distal end part214of the lower arm208and the proximal end part216of the upper arm210when the lower arm208and the upper arm210are connected to each other, and thereby being insertable into the gap.

The guide mechanism74includes a rail82, support arms84and86, and an end plate88. The rail82extends along an axis A5, and a proximal end of the rail82is fixed to the outer surface80bof the second part80, while a distal end of the rail82is fixed to the end plate88. The axis A5is substantially parallel to the rotational axis A3of the upper arm210.

As illustrated inFIG.9, the rail82includes an upper wall82a, a pair of side walls82bextending downward from both side edges of the upper wall82aso as to be opposite to each other, and a pair of collars82cprotruding from the pair of side walls82b. The upper wall82a, the side walls82b, and the collars82cdefine a recess82dof a substantially T-shaped cross section inside the rail82.

As illustrated inFIG.8, the support arm84is disposed at one side of the rail82so as to be separate away from the rail82, and a proximal end of the support arm84is fixed to the outer surface80bof the second part80, while a distal end of the support arm84is fixed to the end plate88. On the other hand, the support arm86is disposed at the other side of the rail82so as to be separate away from the rail82, and a proximal end of the support arm86is fixed to the outer surface80bof the second part80, while a distal end of the support arm86is fixed to the end plate88. The support arms84and86extend linearly along the axis A5. The end plate88extends in a direction orthogonal to the axis A5, and integrally connects the rail82and the support arms84and86to each other.

The movable portion76is guided by the guide mechanism74to linearly move along the axis A5with respect to the fixed portion72. Specifically, as illustrated inFIG.9, the movable portion76includes a main body90extending in a vertical direction, a flange92protruding from an upper end of the main body90to both sides of the main body90, and an annular suspension tool94provided at a lower end of the main body90.

The flange92is housed in the recess82dof the rail82. A plurality of rollers96are interposed between the flange92and the collars82c. The rollers96are each provided in the rail82so as to be rotatable about an axis orthogonal to the axis A5, and disposed to align along the axis A5.

The flange92engages the collars82cvia the rollers96, by which the movable portion76is prevented from falling off from the rail82, and the guide mechanism74smoothly guides a linear-movement of the movable portion76along the axis A5. The suspension tool94is so-called an eye bolt. The main body90, the flange92, and the suspension tool94are integrally coupled to each other so as to form the movable portion76that is a single monolithic member.

The support16is attached to the movable portion76. Specifically, as illustrated inFIG.8, the hook52of the support16is suspended from the suspension tool94of the movable portion76, whereby the support16is suspended from the movable portion76. The movable portion76linearly moves with respect to the fixed portion72so as to move the support16and the reduction gear202supported by the support16in the horizontal direction.

By linearly moving the movable portion76of the jig70, the operator can move the reduction gear202suspended from the support16closer to and away from the attachment portion (the proximal end216) in the robot200where the reduction gear is to be attached. According to this configuration, similar as the above-described jig10, since it is not necessary to move the reduction gear202by the heavy machine, the work of replacing the reduction gear202can be made more efficient.

Next, a jig100according to still another embodiment will be described with reference toFIG.10toFIG.13. The jig100differs from the above-described jig70in a movable portion102. Specifically, as illustrated inFIG.11, the movable portion102includes a first linear-motion member104and a second linear-motion member106.

The first linear-motion member104is attached to the fixed portion72via the guide mechanism74, and is guided by the guide mechanism74so as to linearly move along the axis A5with respect to the fixed portion72. Specifically, the first linear-motion member104includes a rail108, and engaging sections110,112and114that are fixedly provided on a top face108eof the rail108so as to protrude upward from the top face108e.

The rail108extends along an axis A6orthogonal to the axis A5. Specifically, as illustrated inFIG.13, the rail108includes an upper wall108a, a pair of side walls108bextending downward from both side edges of the upper wall108aso as to be opposite to each other, and a pair of collars108cprotruding from the pair of side walls108b. The upper wall108a, the side walls108b, and the collars108cdefine a recess108dhaving a substantially T-shaped cross section inside the rail108.

Referring again toFIG.11, the engaging section110is disposed at a substantially center part of the top face108eof the rail108, and engages the rail82so as to be linearly movable. Specifically, as illustrated inFIG.12, the engaging section110includes a main body116and a flange118protruding from an upper end of the main body116to both sides. The main body116extends upward from the top face108eof the rail108. The flange118is housed inside the recess82dof the rail82, and the rollers96are interposed between the flange118and the collars82cof the rail82.

As illustrated inFIG.11, the engaging section112is disposed at one side of the engaging section110so as to be separate away from the engaging section110, and includes a through hole112ain which the support arm84is slidably received. On the other hand, the engaging section114is disposed at the other side of the engaging section110so as to be separate away from the engaging section110, and includes a through hole114ain which the support arm86is slidably received.

Note that rolling elements, a low-friction material, a lubricant, or the like may be provided inside the through holes112aand114ain order to allow smooth sliding motion relative to the support arms84and86. In this way, the engaging sections110,112and114respectively engage the rail82, the support arms84and86, whereby the first linear-motion member104is guided to linearly move along the axis A5without falling off from the guide mechanism74.

The second linear-motion member106is movably attached to the first linear-motion member104, and guided by the rail108of the first linear-motion member104so as to move along the axial line A6with respect to the fixed portion72. Specifically, as illustrated inFIG.13, the second linear-motion member106includes the main body90, the flange92, and the suspension tool94similar as the above-described movable portion76. A plurality of rollers120are interposed between the flange92of the second linear-motion member106and the collars108cof the rail108.

The rollers120are each provided in the rail108so as to be rotatable about an axis orthogonal to an axis A6(i.e., parallel to the axis A5), and disposed to align along the axis A6. The flange92of the second linear-motion member106engages the collars108cvia the rollers120, whereby the second linear-motion member106is guided by the rail108to linearly move along the axis A6while being prevented from falling off from the rail108.

The support16is attached to the movable portion102. Specifically, as illustrated inFIG.10andFIG.11, the hook52of the support16is suspended from the suspension tool94of the second linear-motion member106, whereby the support16is suspended from the second linear-motion member106. By the first linear-motion member104linearly moving along the axis A5and by the second linear-motion member106linearly moving along the axis A6, the movable portion102moves the support16and the reduction gear202supported by the support16in the horizontal direction along the axes A5and A6.

According to the present embodiment, by linearly moving the movable portion102of the jig100, the operator can move the reduction gear202suspended from the support16closer to and away from the attachment portion (the proximal end216) of the robot200to which the reduction gear is to be attached. According to this configuration, similar as the above-described jig10, it is not necessary to move the reduction gear202by the heavy machine, the work of replacing the reduction gear202can be made more efficient.

Further, in the present embodiment, the movable portion102includes the first linear-motion member104linearly movable along the axis A5, and the second linear-motion member106linearly movable along the axis A6. According to this configuration, the operator can more finely adjust the position of the reduction gear202by moving the reduction gear202suspended from the support16in a plurality of directions.

Next, a jig130according to still another embodiment will be described with reference toFIG.14andFIG.15. The jig130differs from the above-described jig10in a movable portion132. Specifically, the movable portion132includes the first rotating member32, a support member134, a second rotating member136, and the linear-motion member34. The first rotating member32is rotatably attached to the fixed portion12via the fitting24(FIG.2) and the fitting26, similar as the above-described jig10.

The support member134is substantially L-shaped, and includes a first part138and a second part140orthogonal to the first part138. The first part138extends substantially parallel to the second arm32bof the first rotating member32, and includes a receiving hole138aextending linearly along the extension direction of the first part138. The distal end of the second arm32bis unrotatably received in the receiving hole138a, whereby the support member134is fixed to the first rotating member32.

Note that the first part138may be unrotatably fixed to the second arm32bby a fastener such as a bolt, or the second arm32band the receiving hole138amay be formed in polygonal shapes such that the second arm32bunrotatably engages a wall surface of the receiving hole138a. The second part140is formed integrally with the first part138, and extends linearly upward from one end of the first part138. The second part140is formed with a receiving hole140aextending linearly in the extension direction of the second part140.

The second rotating member136is attached to the first rotating member32so as to be rotatable about an axis A7. Specifically, the second rotating member136includes a first arm136aextending linearly along the axis A7and a second arm136bextending linearly in a direction orthogonal to the axis A7. The first arm136ais rotatably received, at its lower end, in a receiving hole140aformed in the second part140of the support member134. Due to this, the second rotating member136is rotatable about the axis A7. The axis A7is parallel to the axis A4and rotates about the axis A4together with the first rotating member32.

The second arm136bis inserted into the main body38of the linear-motion member34so as to contact the rolling elements40(FIG.5) of the linear-motion member34, whereby the linear-motion member34can linearly move along the second arm136b. Note that, in the embodiment illustrated inFIG.15, although the pair of stoppers36described above is not illustrated, in order to limit the movement range of the linear-motion member34, the pair of stoppers36may be provided on the second arm136b, similar as the above-described jig10.

The support16is attached to the linear-motion member34of the movable portion132. In the present embodiment, by the first rotating member32rotating around the axis A4, by the second rotating member136rotating around the axis A7, and by the linear-motion member34linearly moving along the second arm136b, the movable portion132moves the support16and the reduction gear202supported by the support16in the horizontal direction.

According to the present embodiment, the operator can move the reduction gear202suspended from the support16closer to and away from the attachment portion (the proximal end part216) in the robot200to which the reduction gear is to be mounted, by moving the movable portion132of the jig130. According to this configuration, similar as the above-described jig10, since it is not necessary to move the reduction gear202by the heavy machine, the work of replacing the reduction gear202can be made more efficient.

Further, in the present embodiment, the movable portion132includes the first rotating member32rotating about the axis A4, and the second rotating member136rotating about the axis A7. According to this configuration, the operator can easily rotate the reduction gear202of a heavy load in two directions by a relatively small force, and finely adjust the position of the reduction gear202.

Note that, in the embodiments described above, the jigs10,70,100, and130are fixed to the proximal end part216of the upper arm210. However, the jig10,70,100, or130can be fixed to the distal end part214of the lower arm208. Such an embodiment is illustrated inFIG.16andFIG.17.

In the embodiment illustrated inFIG.16andFIG.17, the fixed portion12of the jig10is detachably fixed to the distal end part214of the lower arm208by the fasteners18. For example, fastening holes (not illustrated) for a predetermined application (e.g., for fastening the stopper) are formed in the distal end part214of the lower arm208, and the fixed portion12can be fixed to the distal end part214by inserting the fasteners18into the through holes20bof the fixed portion12so as to be fastened to the fastening holes formed in the distal end part214.

In such an embodiment, similar as the above-described embodiments, by moving the movable portion14of the jig10, the operator can move the reduction gear202suspended from the support16closer to and away from the attachment portion (the proximal end part216) to which the reduction gear is to be mounted. It should be understood that the jig70,100, or130can be similarly fixed to the distal end part214of the lower arm208.

Note that, for smooth rotation of the rotating member32or136, rolling elements, a low-friction material, a lubricant, or the like may be provided in the hole28of the fitting24, the through hole30of the fitting26, or the receiving hole140adescribed above. Further, in the jig10or130, a locking mechanism may be provided that locks the rotating member32when the rotating member32is rotated by a predetermined angle (e.g., 180°) from the position illustrated inFIG.1andFIG.2. Such a locking mechanism may be e.g. a snap-fit mechanism, and include a first engaging part provided at the rotating member32and a second engaging part provided at the fitting24or26.

Similarly, in the jig130, a locking mechanism may be provided that locks the second rotating member136at a predetermined angle with respect to the second part140of the support member134. Such a locking mechanism may be e.g. a snap-fit mechanism, and include a first engaging part provided at the second rotating member136and a second engaging part provided at the second part140.

Further, in the jig10, a locking mechanism may be provided that locks the linear-motion member34at a predetermined position with respect to the second arm32b. Similarly, in the jig70(or100), a locking mechanism may be provided that locks the movable portion76(or the engaging section110) at a predetermined position with respect to the rail82. Further, in the jig100, a locking mechanism may be provided that locks the second linear-motion member106at a predetermined position with respect to the rail108. The locking mechanism for the linear-motion member34, the movable portion76, the engaging section110, or the second linear-motion member106may be a snap-fit mechanism or may include a pair of magnets that attract each other.

In the embodiments described above, a case is described in which the fasteners18are used to fix the fixed portion12to the upper arm210or the lower arm208. However, any member or structure may be employed that can fix the fixed portion12to the upper arm210or the lower arm208. For example, the fixed portion12may be fixed to the upper arm210or the lower arm208by engagement between a first engaging part formed at the fixed portion12and a second engaging part formed at the upper arm210or the lower arm208. Similarly, any member or structure may be employed in place of the fastener64or66.

The suspending device44may be omitted from the support16, and the mounting member46may be directly fixed to the movable portion14,76,102, or132. Further, the linear-motion member34may be omitted from the movable portion14or132. The linear-motion member34may include a low-friction material, a lubricant, or the like, instead of the rolling elements40. The mounting member46is not limited to the above-described configuration, but may have any structure attachable to the reduction gear202. Similarly, the fixed portion12or72is not limited to the above-described configuration, but may have any structure attachable to the upper arm210or the lower arm208.

In the above-described embodiments, the jig10,70,100, or130is attached to the lower arm208or the upper arm210in order to replace the reduction gear202that connects the lower arm208and the upper arm210. However, the jig10,70,100, or130may be used to replace any reduction gear that connects a first constituent element and a second constituent element of the robot200so as to perform a speed-reduction operation, for example, a reduction gear that connects the rotary barrel206and the lower arm208, or a reduction gear that connects the upper arm210and the wrist220.

Although the present disclosure has been described above through the embodiments, the embodiments described above are not intended to limit the claimed invention.