JP2003275987A - Scara type robot - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small SCARA type robot that increases the positioning accuracy of an arm. <P>SOLUTION: A flexible tube 71 containing wiring is arranged in an inverted U bend between a second arm 24 and a base 22. Root portions 71b near a bend portion 71a of the flexible tube 71 are interconnected with a connecting stay 81. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a SCARA type robot in which wiring and piping are bridged between a rotary arm and a base.

[0002]

2. Description of the Related Art As a conventional SCARA type robot of this type, there is, for example, one constructed as shown in FIGS. FIG. 12 is a side view of a conventional SCARA robot, FIG. 13 is a plan view of the same, and FIG. 14 is a sectional view of a flexible tube.

In these drawings, a conventional SCARA robot shown by reference numeral 1 is used in a clean room, and a first arm 3 is provided on a base 2 so as to be horizontally rotatable. A second arm 4 is provided on the upper side of the rotation end of the first arm 3 so as to be horizontally rotatable. In the base 2, a motor (not shown) for driving the first arm 3 is provided inside the housing 5, and a speed reducer 6 for connecting the output shaft of the motor and the first arm 3 is provided at the upper part. It is provided.

In this speed reducer 6, the housing 6a has a base 2
A first support shaft (not shown) that is fixed to the first arm 3 and projects downward from the base end portion of the first arm 3 is rotatably supported.
Power is transmitted from the motor in the base 2 to the first support shaft via the speed reducer 6, whereby the first arm 3 rotates with respect to the base 2. The pivot end of the first arm 3 is provided with a second support shaft (not shown) extending upward, and the second arm 4 is connected via the second support shaft.

The second arm 4 is provided with a working shaft 7 at its rotating end, and various driving devices (not shown) are mounted inside a cover 8 attached to the upper part thereof. The drive device includes a motor for rotating the second arm 4 with respect to the first arm 3, a motor for vertically moving the working shaft 7, and a motor for rotating the working shaft 7. For example, a motor. Although not shown, the work shaft 7 has, for example, a suction nozzle for mounting electronic components on the lower end,
A chuck for gripping the work, a nozzle for supplying paste solder, and the like are attached.

The motor for driving the second arm 4 is provided so that the output shaft is located on the same axis as the second support shaft on the rotating end side of the first arm 3, The second arm 4 is connected to the second support shaft of the first arm 3 via a speed reducer 9 provided below the base end portion of the arm 4. That is, when the output shaft of this motor rotates, the second
The arm 4 rotates with respect to the first arm 3. The load of the second arm 4 is determined by the housing 9a of the speed reducer 9.
It is transmitted to the second support shaft via and is supported by the first arm 3.

A power supply cable (motor wire) for each motor provided on the second arm 4 and a cable (resolver wire) for a motor rotation position detector are provided between the upper portion of the cover 8 and the base 2. It is wired through the inside of the flexible tube 10 which is bridged over. This flexible tube 1
In addition to the above-described wiring, an air suction tube (user pipe) for sucking air from the suction nozzle when the suction nozzle is attached to the work shaft 7 and the work shaft 7
A cable (user wiring) for supplying power to an electrically driven tool or the like attached to, a suction pipe for sucking dust generated from each device of the second arm 4, and the like are also passed.

The flexible tube 10 is formed of a flexible plastic in a bellows shape. As shown in FIG. 14, a motor wire 11, a resolver wire 12, a user wire 13 and a user pipe 14 are provided inside. 1
The harness 15 is passed through in the state of being housed in the harness 15, and three suction pipes 16 are passed adjacent to the harness 15. The harness 15 is formed of flexible plastic into a cylindrical shape.

A plurality of wirings and pipes are housed in one flexible tube 10 as described above.
This is to prevent dust generated by the wirings and pipes slidingly contacting each other when the arms 3 and 4 of FIG. The three suction pipes 16
The portion to be sucked by is the cover 8 of the second arm 4.
The internal space of the second arm 4 and the joint portion of the base end portion of the second arm 4,
The work shaft penetrating portion of the rotating end of the second arm 4 and the like.

Both ends of the flexible tube 10 are attached to the cover 8 of the second arm 4 and the housing 5 of the base 2 by rotary clamps 17, respectively.
In order to easily bend when the first and second arms 3 and 4 rotate, they are bent so as to have an inverted U shape in the side view shown in FIG. The conventional flexible tube 10 is formed by bending a straight U-shape into an inverted U-shape and is assembled. Both ends of the flexible tube 10 are held by the clamps 17, so that the flexible tube 10 is elastically deformed to form an inverted U-shape. The shape is kept in a shape.

The rotary clamp 17 has a cylindrical boss 17a to which the tip of the flexible tube 10 is fixed.
And a base member 17b that rotatably supports the boss 17a via a bearing (not shown). When the base member 17b is fixed to the second arm 4 or the base 2, and when the first and second arms 3 and 4 rotate, both ends of the flexible tube 10 together with the boss 17a form the second. It can rotate with respect to the arm 4 or the base 2.

The rotary clamp 1 having the bearing as described above
The both ends of the flexible tube 10 are supported by 7 because the reaction force in the twisting direction applied from the flexible tube 10 to both arms 3 and 4 when the first and second arms 3 and 4 are rotated. This is because the both ends of the flexible tube 10 are prevented from slidingly contacting the second arm 4 and the base 2 and dust is generated when the arm is rotated.

[0013]

In the conventional SCARA-type robot 1 having the above-described structure, when further downsizing is attempted, when the first and second arms 3 and 4 are largely rotated. There is a problem that the positioning accuracy is lowered. This occurs in the flexible tube 10 when the first arm 3 and the second arm 4 largely rotate and the flexible tube 10 bends so that the distance between its one end and the other end becomes short. It is considered that the stress causes a reaction force to be applied to the second arm 4 and the base 2.

Since both ends of the flexible tube 10 are rotatably supported with respect to the second arm 4 and the base 2 as shown by an arrow A in FIG.
It acts mainly in the horizontal direction and in the direction in which the interval becomes longer. By the reaction force A being applied to the second arm 4 and the base 2 in this way, a bending moment M for urging the arms 3 and 4 in the counterclockwise direction in FIG.

The reaction force A has a greater influence as the rigidity of the speed reducers 6 and 9 and the supporting bearings provided at the joints becomes lower. That is, since the SCARA robot 1 is downsized and the rigidity thereof is reduced, the bending moments M cause the arms 3 and 4 to incline with respect to the horizontal direction. As a result, the work shaft 7 is vertically moved. The angle with respect to changes, and the positioning accuracy deteriorates.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a small-scale SCARA robot in which the positioning accuracy of the arm is high.

[0017]

In order to achieve this object, a SCARA robot according to the present invention has a flexible structure in which wiring is housed between an arm that rotates with respect to a base and the base. In a SCARA type robot in which a pipe having the above is bent in a U shape and bridged, the root parts in the vicinity of the bent part of the pipe are connected to each other by a connecting stay. According to the present invention, the bent portion of the wiring housing pipe is held at a constant curvature by the connecting stay. Therefore, by bending the linearly shaped pipe for storing wiring into an inverted U-shape, it is possible to restrict the opening of both ends of the pipe by the connecting stay due to the internal stress generated in the pipe.

A scalar type robot according to a second aspect of the present invention is the scalar type robot according to the first aspect of the present invention, in which the inner ring side member and the outer ring side member of the bearing in the arm support system are A first housing and a second housing having peripheral walls extending in the vertical direction outside the radial direction of the bearing are provided, and the peripheral walls of the both housings are located on the same axial line and inside and outside the radial direction. The bearing is interposed between these peripheral walls. According to the present invention, two types of bearings are provided in the support system of the arm so as to be located inside and outside in the radial direction.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) An embodiment of a SCARA robot according to the present invention will be described in detail below with reference to FIGS. 1 to 9. FIG. 1 is a side view of a SCARA robot according to the present invention, and FIG. 2 is a plan view of the same, showing the wiring storage pipe in a broken state. 3 is a front view of a SCARA robot according to the present invention, FIG. 4 is an enlarged cross-sectional view showing a connecting portion between a base and a first arm and a flexible tube, and FIG. 5 is a second arm and a flexible tube. It is sectional drawing which expands and shows the connection part of. FIG. 6 is an enlarged plan view showing the connecting stay, FIG. 7 is a cross-sectional view of a flexible tube, and FIG. 8 is a view for explaining the operation of the SCARA robot according to the present invention. The first arm and the second arm are arranged in a straight line, and the figure (b) shows the state in which the distance between both ends of the flexible tube is the longest, and the figure (c).
Shows a state in which the distance between both ends of the flexible tube is the shortest. FIG. 9 is a side view of the flexible tube.

In these figures, the reference numeral 21 is a SCARA type robot according to this embodiment. This SCARA type robot 21 is used in a clean room, and is composed of a first arm 23 and a second arm 24 which rotate in a horizontal direction with respect to a base 22 so that the work shaft 2 can be operated.
5 moves in the horizontal direction, the work shaft 25 moves in the vertical direction by the elevating device 26 provided on the second arm 24, and the work shaft 25 rotates by the rotation drive device 27. Although not shown, the working shaft 25 has, for example, a vacuum suction nozzle for mounting electronic components, a chuck for gripping a work, or a nozzle for supplying paste solder at the lower end.

The base 22 is formed by providing a plate 32 on a box-shaped housing 31, and the first arm driving device 3 is provided inside the housing 31.
3 is provided. As shown in FIGS. 1 and 2, the first arm 23 has a base end portion (the end portion on the right side in FIG. 1) supported by a first arm driving device 33 in the base 22 to rotate. The second arm 24 is attached to the end portion via the second arm driving device 34. The first arm driving device 33 includes a first arm driving motor 35 supported by the plate 32 of the base 22 in a state where the axial direction is parallel to the vertical direction, and an upper end portion of the motor 35. It is composed of a fixed first arm drive speed reducer 36.

As shown in FIG. 4, the speed reducer 36 is a Harmonic Drive (registered trademark) speed reducer, which reduces the rotation of the motor 35 to reduce the rotation of the motor 35 and the first support shaft 37 on the first arm side.
The wave generator 38 is fixed to the upper end of the rotary shaft 39 of the motor 35, and the flexspline 40 is fixed to the first support shaft 37 by a fixing bolt 41. This reducer 3
The circular spline 42 of No. 6 is fixed to the speed reducer housing 43 provided on the plate 32 of the base 22. The first support shaft 37 is rotatably supported by the reduction gear housing 43 by a bearing 44, and an upper end portion protruding upward from the reduction gear housing 43 is fixed to the first arm 23.

The second arm drive device 34 includes a second arm drive speed reducer 46 supported by the first arm 23 via a second support shaft 45, and the second arm drive device. And a second arm driving motor 47 provided above the speed reducer 46. The second arm drive speed reducer 46 has a structure similar to that of the first arm drive speed reducer 36. The second arm drive speed reducer 46 reduces the rotation of the second arm drive motor 47 to reduce the rotation speed of the second arm drive motor 47. 2 support shaft 4
5 is transmitted. The second support shaft 45 is the reduction gear 4
6 is rotatably supported by a housing 48 (not shown), and a lower end portion protruding downward from the reduction gear housing 48 is fixed to the first arm 23.

The second arm driving motor 47 has the same structure as that of the first arm driving motor 35, and the upper portion of the second arm 24 is in a state where the axial direction is parallel to the vertical direction. Supported by. The rotation of the rotation shaft (not shown) of the motor 47 causes the second support shaft 45 to be decelerated and rotated by the second arm drive speed reducer 46. Then second
The arm 24 rotates with respect to the first arm 23.

The second arm 24, as shown in FIG.
A work shaft 25 is provided at a rotating end opposite to the base end connected to the first arm 23, and the second arm driving device 34, and an elevating device 26 and a rotation driving device 27 described later. A cover 49 for covering the above is attached.

The working shaft 25 is connected to the upper connecting rod 25.
a and a ball spline shaft 25b connected to the lower end of the connecting rod 25a. The connecting rod 25 extends vertically through the shaft center of the rotary drive device 27, and the ball screw nut 51 of the elevating device 26 is rotatably connected to the upper end of the connecting rod 25. The connecting portion between the connecting rod 25a and the ball screw nut 51 allows the working shaft 25 to rotate, but is configured so that the working shaft 25 does not move vertically with respect to the ball screw nut 51. There is.

A ball spline nut 52 is connected to the ball spline shaft 25b, and the rotary drive device 27 is connected via the ball spline nut 52 and the hollow shaft 53.
Output shaft 54 is connected. The connecting portion between the ball spline shaft 25b and the ball spline nut 52 is
The rotation of the ball spline nut 52 is transmitted to the ball spline shaft 25b, but the vertical movement of the ball spline shaft 25b is not restricted.

The elevating device 26 having the ball screw nut 51 is connected to the elevating motor 55 supported by the second arm 24 such that the axial direction is parallel to the vertical direction, and the rotating shaft of the motor 55. The ball screw shaft 56 and the ball screw nut 51 screwed onto the ball screw shaft 56 are included. The upper end of the connecting rod 25a is rotatably supported by a connecting plate 51a integrally provided with the ball screw nut 51. As shown in FIG. 3, a tie bar 57 is provided between the connecting plate 51a and the plate 55a at the upper end of the lifting motor 55 so as to prevent the connecting plate 51a and the ball screw nut 51 from rotating. ing.

The elevating motor 55 includes the first and second motors.
The same motors as the arm driving motors 35 and 47 are used, and are mounted on the substantially central portion of the second arm 24 in the longitudinal direction. When the lifting motor 55 rotates, the ball screw shaft 56 rotates, and the work shaft 25 moves vertically together with the ball screw nut 51. The rotary drive device 27 is composed of a speed reducer 61 having a tubular output shaft 54 connected to the ball spline nut 52, and a rotary drive motor 62 provided above the speed reducer 61.

As the speed reducer 61, one equivalent to the speed reducers 36 and 46 for driving the first and second arms is used, and the rotation of the rotation driving motor 62 is decelerated and transmitted to the output shaft 54. belongs to. That is, when the rotation driving motor 62 rotates, the output shaft 54 of the speed reducer 61 is rotated.
Rotates, and this rotation is transmitted to the work shaft 25 by the ball spline nut 52, and the work shaft 25 rotates. The ball spline nut 52 is fitted to the work shaft 25 so as to be movable in the vertical direction, so that the lifting and lowering operation of the work shaft 25 by the lifting device 26 is not hindered.

The SCARA type robot 2 configured as described above
1, the first arm 23 is rotated by the power of the first arm driving motor 35, and the second arm 24 is rotated by the power of the second arm driving motor 47 with respect to the first arm 23. Move. Further, in the SCARA type robot 21, the work shaft 25 is moved up and down by the power of the lifting motor 55, and the work shaft 25 is rotated by the power of the rotation drive motor 62.

Each motor 47, 5 on the second arm 24
5, 62 power supply cables (motor wires) and each motor 4
The cables (resolver wires) of the rotation detectors (not shown) provided at 7, 55, 62 are provided in order to prevent dust generated by sliding contact between the cables during arm rotation from scattering in the clean room. The flexible tube 71 laid between the second arm 24 and the base 22.
Is wired inside. This flexible tube 7
In addition to the wiring, a cable (user wiring) for supplying power to an electrically driven tool attached to the working shaft 25, or when a suction nozzle is attached to the working shaft 25 An air suction tube (user piping) for sucking air from the suction nozzle, and an air supply tube (user piping) for supplying pressurized air to this tool when a pneumatically driven tool is attached to the work shaft 25. ) And a suction pipe for sucking dust generated from each device of the second arm 24.

The flexible tube 71 is the same as the conventional one, and is formed into a bellows shape with flexible plastic. As shown in FIG. 7, the motor wire 72 and the resolver wire 73 are internally provided. User wiring 74 is 1
The harness 75 is passed through in a state of being housed in the harness 75, and four user pipes 76 and two suction pipes 77 are passed through so as to be adjacent to the harness 75. As the harness 75, the same harness as the conventional one is used, and is formed in a cylindrical shape from flexible plastic.

The motor wire 72 and the resolver wire 73
Is guided from one of the motors 47, 55, 62 to the one end of the flexible tube 71 through the inside of the cover 49, and passes through the flexible tube 71 and the base 22 to drive the first arm from the rear part of the base 22. It is led out of the base 22 together with the motor wire of the motor 35 and the resolver wire. A cable clamp provided at the lead-out portion is shown by reference numeral 78 in FIG. One end of the user wiring 74 is connected to a connector (not shown) provided on the cover 49 of the second arm 24, and is guided into the base 22 from inside the cover 49 through the flexible tube 71. Motor wire 72
Similarly to the above, the base 22 is led out of the rear of the base 22.

The flexible tube 71 is used in a state in which a linearly shaped one is bent in an inverted U-shape that opens downward, and as shown in FIG. 1, in the vicinity of the bent portion 71a. The connecting stays 81 are attached to the root portions 71b, 71b (portions extending in the vertical direction) of the base portion 71b, and the distal end portion (lower end portion) of the root portion 71b is attached to the second arm 24 and the base 22 by rotary clamps 82, It is rotatably attached via 82. The flexible tube 71 constitutes the wiring pipe according to the present invention.

The connecting stay 81 is shown in FIGS.
As shown in FIG.
It is composed of a base portion 84 in which a through hole 83 through which 1b penetrates is formed, and a connecting plate 86 fixed to the base portion 84 by a fixing bolt 85. The base portion 84 is attached to two root portions 71b of the flexible tube 71, and these base portions 84 are connected by a connecting plate 86. The base portion 84 is formed of plastic having elasticity, and the through hole 83 is formed to open laterally on the other side portion opposite to the one side portion to which the connecting plate 86 is attached. A clamp 87 is fixed to the other side portion. Also, the base 84 is
Through hole 83 when clamp 87 is not attached
The through hole 83 has a hole diameter slightly larger than the outer diameter of the flexible tube 71 so that the flexible tube 71 can be inserted thereinto, and the clamp tube 87 is attached by narrowing the open portion to hold the flexible tube 71. Has been done.

As shown in FIGS. 4 and 5, the rotary clamp 82 includes a plug 88 provided at the tip of the flexible tube 71, a boss 89 to which the plug 88 is screwed, and a boss 89. The base ring 91 is rotatably supported by the bearing 90. The rotary clamp 82 provided on the base 22 is shown in FIG.
As shown in, the base ring 91 is fixed to the plate 32 of the base 22 by fixing bolts 92. On the other hand, the rotary clamp 82 provided on the second arm 24
As shown in FIG. 5, the base ring 91 penetrates the upper wall 49 a of the cover 49 of the second arm 24 to cover the cover 49.
It is inserted inside and is fixed to a supporting stay 93 provided inside the cover 49 by a fixing bolt 94. The supporting stay 93 is fixed to the plate 55a at the upper end of the lifting motor 55 by a fixing bolt 95.

In addition to the rotary clamp 82, the supporting stay 93 also supports the wiring passing through the flexible tube 71. That is, the support stay 9
3, a wiring support bracket indicated by reference numeral 96 in FIG. 5 is provided on the way, and the wiring led out downward from the flexible tube 71 in the cover 49 is supported via the bracket 96. The other end of this wiring, that is, the end led out from the flexible tube 71 into the base 22 is supported by the housing 31 of the base 22 via a bracket (not shown). The four user pipes 76 passing through the flexible tube 71 are
As shown in FIG. 1, the second arm 24 is connected to an air joint 97 outside the cover 49 by passing under the base end portion of the second arm 24.
The suction pipe 77 of the book is connected to suction members 98 and 99 provided at the base end portion and the rotation end portion of the second arm 24.

The air joint 97 has a pipe connection port 97a.
(See FIG. 2) is supported by the base ring 91 of the rotary clamp 82 via a plate-shaped bracket 100 in a state of pointing upward. The pipe connecting port 97a is connected to a suction nozzle on the work shaft 25 side or another pipe (not shown) extending from a pneumatically driven tool. Of the two suction members 98, 99, the suction member 98 provided at the base end portion of the second arm 24 is mainly a joint portion of the base end portion (of the second arm driving speed reducer 46). (In housing 48)
From the work shaft penetrating portion (inside the housing of the speed reducer 61) of the rotating end of the second arm 24, and the other suction member is configured to suck air.

In the scalar type robot 21 configured as described above, since both ends of the flexible tube 71 are connected to the second arm 24 and the base 22 via the rotary clamps 82, In the case where the second arm 23, 24 rotates and the flexible tube 71 is twisted, both ends of the flexible tube 71 rotate with respect to the second arm 24 and the base 22. Further, when the arms 23 and 24 are rotated as shown in FIG. 8 and the distance between the both ends of the flexible tube 71 changes, the bending portion 71 a of the flexible tube 71 is prevented from changing its curvature by the connecting stay 81. Since it is regulated, as shown by a chain double-dashed line in FIG. 9, the base portion 71b of the flexible tube 71 below the connecting stay 81 is bent by elastic deformation.

The above-mentioned interval when both arms 23 and 24 extend linearly as shown in FIG. 8 (a) is indicated by symbol D1 in FIG. 8 and FIG. 9, and as shown in FIG. The distance when the parts are most distant from each other is indicated by D2. Further, as shown in FIG. 8C, the distance when the both end portions are closest to each other is indicated by D3. That is, when the arm is rotated, the second arm 2 is caused by the stress generated in the flexible tube 71 by bending the root portion 71b below the connecting stay 81 as described above.
The reaction force is applied from the flexible tube 71 to the base 4 and the base 22.

Therefore, in the SCARA type robot 21, although the flexible tube 71 is bent in an inverted U-shape from the natural state where the flexible tube 71 is linear, the flexible tube 71 is flexible in this bending state. The connecting stay 81 prevents the both ends of the flexible tube 71 from opening due to the internal stress generated in the tube 71.
Since it can be regulated by the second arm 24
The reaction force applied to the base 22 from the flexible tube 71 can be reduced by the internal stress as compared with the conventional case.

(Second Embodiment) As shown in FIGS. 10 and 11, a reinforcing member can be provided at the supporting portion of each arm. FIG. 10 is a side view showing another embodiment of the SCARA type robot, and FIG. 11 is an enlarged sectional view showing a supporting portion of the arm. In these figures, the same or equivalent members as those described with reference to FIGS. 1 to 9 are designated by the same reference numerals and detailed description thereof will be appropriately omitted.

In the SCARA type robot 21 shown in FIG. 10, reinforcing bearings 101 and 102 are provided on the supporting portions of the first and second arms 23 and 24 as shown in FIG. In the reinforcing bearing 101 provided in the supporting portion of the first arm 23, the inner ring 103 is fitted and supported in the first housing 104, and the outer ring 105 is held in the second housing 106.
Is fitted and supported. The first housing 10
Reference numeral 4 denotes a disk-shaped member, and the first arm 23 (a member on the inner ring side of the bearing 44 in the first arm driving speed reducer 36) in a state where the first support shaft 37 penetrates the shaft center portion. It is fixed to the lower surface of the with a fixing bolt 107. The outer peripheral portion of the first housing 104 is integrally formed with a peripheral wall 104a made of a cylinder extending in the axial direction (vertical direction), and is connected to the inner ring 103 via the peripheral wall 104a.

The second housing 106 is formed in an annular shape, and the first arm driving speed reducer 36 is formed in a state where a gap is formed between the second housing 106 and the lower surface of the first housing 104.
It is fixed to the housing 43 (a member on the outer ring side of the bearing 44 in the speed reducer 36) by a fixing bolt 108.
Further, the outer peripheral portion of the second housing 106 is formed such that a peripheral wall 106a formed of a cylinder extending in the axial direction is located radially outside the peripheral wall 104a of the first housing 104. It is connected to the outer ring 105 through.

That is, the reinforcing bearing 101 is formed on the first and second housings 104 and 106 so as to be located inside and outside in the radial direction.
It is interposed between 6a. An annular stopper plate 109 for holding the reinforcing bearing 101 on the second housing 106 is fixed to the peripheral wall 106 a of the second housing 106 by fixing bolts 110. In this embodiment, the second housing 106
The suction member 111 is attached to the first housing 1
04 and the second housing 106, and the space inside the housing 43 of the speed reducer 36 sucks air by the suction member 111, and the bearings 44, 10
1 and the dust generated at the sliding portion in the speed reducer 36 are prevented from scattering in the clean room.

In the reinforcing bearing 102 provided on the supporting portion of the second arm 24, the inner ring 112 has the first housing 1
The outer ring 114 is fitted and supported by the second housing 115. The first housing 113 is formed in a cylindrical shape in which the housing 48 of the second arm driving speed reducer 46 is housed, and the second bolt 24 (the speed reducer 46
The inner bearing 117 is fixed to the outer ring side member). A peripheral wall 113 composed of a lower end portion of the first housing 113
The inner ring 112 is fitted to the outer peripheral surface of a.

The second housing 115 is formed in an annular shape and is fixed to the upper surface of the first arm 23 (a member on the inner ring side of the bearing 117 in the speed reducer 46) by a fixing bolt 118. A cylindrical peripheral wall 115a extending upward is integrally formed on the outer peripheral portion. This peripheral wall 115
a is the peripheral wall 113a of the first housing 113
The outer race 114 of the reinforcing bearing 102 is formed on the outer side in the radial direction, the outer race 114 of the reinforcing bearing 102 is fitted to the inner circumferential surface, and the bearing holding stopper plate 119 is provided on the upper surface.
It is fixed by 0. In FIG. 11, 121 indicates a flexspline of the second arm driving speed reducer 46, 122 indicates a wave generator, and 123 indicates a circular spline.

The space inside the speed reducer 46 and the first space
Air is sucked into the space surrounded by the second housings 113 and 115 by the suction member 98 provided at the base end portion of the second arm 24, and the bearings 102 and 11 are
7 and the dust generated from the sliding parts in the speed reducer 46 are not scattered in the clean room. In order to further suppress the scattering of dust, the SCARA robot 21 according to the present embodiment has the first housing 131 and the first housing 131 at the rotating end of the second arm 24 as shown in FIG. The second housing 132 is provided so as to surround the speed reducer 61 for the rotating device.
Air is sucked by the suction member 99 from the space inside 1,132.

Reinforcing bearings 101, 102 interposed as described above on the supporting portions of the first and second arms 23, 24.
Is a so-called four-point contact type, which is capable of supporting a load in the radial direction, a load in the thrust direction, and a load in the direction in which the axis is inclined (moment load). The reinforcing bearings 101 and 102 may be composed of one cross roller bearing and a pair of angular bearings. This bearing 101, 10
By providing a non-contact type seal member (not shown) between the inner ring and the outer ring of No. 2, it is possible to more effectively prevent the sliding powder from being scattered because the inside of the bearing is also sucked. Will be able to.

As shown in the second embodiment, the bearing 4 supporting the first arm 23 and the second arm 24.
First and second housings 104 and 113 and second and second housings 106 and 115 are provided on the inner and outer ring members of 4, 117.
And peripheral walls 104a and 113 formed on these housings so as to be located inside and outside in the radial direction.
a, 106a, 115a between the reinforcing bearings 101, 10
2, the bearings 44 and 117 are positioned inside and outside in the radial direction in the support system of both arms 23 and 24, that is, the bearings 44 and 117 are positioned inside and the reinforcing bearing 10 is provided.
Two types are provided so that 1, 102 are located outside. Therefore, the SCARA robot 21 according to this embodiment can improve the rigidity of the supporting portions of the first and second arms 23 and 24, and thus can firmly support both arms even if the size is reduced. become.

In the first and second embodiments described above, the SCARA type robot 21 used in the clean room is used.
However, the present invention is not limited to such a limitation and can be applied to a SCARA robot used in any environment. In addition, the scalar type robot 21 shown in the first and second embodiments is
When it is used in an environment in which it is not necessary to suppress the scattering of the amount of sliding, it is possible to supply air from the outside to the joint portion and adopt a so-called air purge type configuration. By adopting this configuration, a dustproof / dripproof SCARA robot can be formed. Particularly in the second embodiment, the bearing 1
By providing a contact-type seal member between the inner and outer races 01 and 102, the dustproof and dripproof properties can be enhanced.

[0053]

As described above, according to the present invention, the bent portion of the wiring containing pipe is held at a constant curvature by the connecting stay. Therefore, by bending the linearly formed pipe for storing wiring into an inverted U-shape, it is possible to restrict the opening of both ends of the pipe by the connecting stay due to the internal stress generated in the pipe.

Therefore, the reaction force applied from the pipe to the arm and the base when the arm is rotated is reduced by the amount of the internal stress as compared with the conventional case, so that the rigidity of the joint portion of the arm is relatively high. Even with a small SCARA robot that becomes extremely low, the positioning accuracy of the arm can be improved.

According to the second aspect of the present invention, the bearing is provided in the support system of the arm so that the bearing is located inside and outside in the radial direction.
Since a variety of types are provided, it is possible to provide a small-scale SCARA robot in which the rigidity of the arm supporting portion is improved and the positioning accuracy of the arm is further improved.

[Brief description of drawings]

FIG. 1 is a side view of a SCARA type robot according to the present invention.

FIG. 2 is a plan view of a SCARA type robot according to the present invention.

FIG. 3 is a front view of a SCARA type robot according to the present invention.

FIG. 4 is an enlarged cross-sectional view showing a connection portion between a base, a first arm and a flexible tube.

FIG. 5 is an enlarged sectional view showing a connection portion between a second arm and a flexible tube.

FIG. 6 is an enlarged plan view showing a connecting stay.

FIG. 7 is a cross-sectional view of a flexible tube.

FIG. 8 is a diagram for explaining the operation of the SCARA robot according to the present invention.

FIG. 9 is a side view of a flexible tube.

FIG. 10 is a side view showing another embodiment of the SCARA type robot.

FIG. 11 is an enlarged sectional view showing a supporting portion of the arm.

FIG. 12 is a side view of a conventional SCARA robot.

FIG. 13 is a plan view of a conventional SCARA robot.

FIG. 14 is a cross-sectional view of a conventional flexible tube.

[Explanation of symbols]

21 ... SCARA type robot, 22 ... Base, 23 ... First arm, 24 ... Second arm, 36, 46 ... Reducer, 37
... first support shafts 43,48 ... housings 44,11
7, 101, 102 ... Bearing, 45 ... Second support shaft, 71 ...
Flexible tube, 71a ... Bent portion, 71b ... Root portion, 72 ... Motor wire, 73 ... Resolver wire, 74 ... User wiring, 81 ... Connecting stay, 104, 113 ... First housing, 106, 115 ... Second housing,
104a, 106a, 113a, 115a ... Peripheral wall.

Claims (2)

[Claims] 1. A SCARA robot in which a flexible pipe containing a wire is bent and bridged in a U shape between an arm that rotates with respect to a base and the base, A scalar type robot characterized in that root portions near the bent portion of the pipe are connected to each other by a connecting stay. 2. The scalar type robot according to claim 1, wherein the member on the inner ring side and the member on the outer ring side of the bearing in the support system of the arm have peripheral walls extending in the vertical direction outside the radial direction of the bearing. A first housing and a second housing are provided, and the peripheral walls of the both housings are formed so as to be located on the same axis and radially inside and outside, respectively.
A scalar type robot characterized by having a bearing interposed between these peripheral walls.