JPS6025692A - Wrist device for industrial robot - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an industrial robot, and particularly to an improvement in a device for driving the wrist of the industrial robot.

[Prior art]

As a conventional device for this purpose, the one shown in FIGS. 1 to 3 is 1y). In the figure, (1) is the first →J・-homotor, (2) is the second servo mode, and (3) is the eighth
The servo mode (4N) is fixed to the output shaft of the first servo mode (1), and the pulley (5) is fixed to the output shaft of the first servo mode (1).
4) is the belt that transmits the rotation to the pulley (6), (7) is the box body, (8) is the pulley fixed to the output shaft of the second servo model (2), and (9) is the pulley ( 8) A belt that transmits the rotation to the pulley θ0, (@ is a box body, U is a pulley fixed to the output shaft of the 8th servo model (3), (2)
is a belt that transmits the rotation of pulley 01) to pulley 03,
Akatsuki is 'cylindrical body, 04), QG is pulley (a), Q
The bevel gears 0L3.0η are fixed to the bevel gears 041 and QQ, respectively, and the bevel gears QQ and 01 are respectively fixed to the bevel gears 041 and QQ.
and (E), 01) are respectively pulley (6), bevel gear 0 fathom,
and a bearing that supports the pulley OO2 bevel gear 0ω, (A),
@, (E) are bevel gear Qq, bevel gear αη, and pulley 0, respectively.
The drive shaft that transmits the rotation of 3, (c), (c),
C33 is a bearing that supports the drive shaft (4), a fort,
(2) and I2B, (to) support the drive shafts (c) and (a), respectively; T3]) is the second link that surrounds the drive shafts (a) and (e), etc.

(7) is the bearing that supports the second link C (D), the first link that supports the second link 6υ at one end, - is the first box fixed to the internal gear Ql, which will be described later. ) is the bearing rotatably supported between the first boxes, (to) is the spur gear fixed to the drive shaft C), 0 to is the internal gear that meshes with the spur gear (C), and 2 is the drive shaft 4 is the cylindrical spur gear that meshes with the spur gear (to), 2) is the bevel gear that is fixed to the spur gear (g), G11) and θ are the spur gears (to). ) and the bearing that supports the heavy weights, 03 is the bevel gear that meshes with the bevel gear), - is the bevel gear that is fixed to the boss of the bevel gear ■, (B) and (Zo is the bevel gear (goods), Pulley (
t4'h is the bevel gear that meshes with the bevel gear (41), and θ is the bevel gear that supports the rotation of the pulley (c). υ is a pulley fixed to the boss of the bevel gear η, and 9 is a pulley that transmits the rotation of υ to the pulley.
The belt, which is fixed to the boss of the pulley wheel, is attached to the second box body, - and O is the pulley ring and the second box body. The bevel gear fixed to the pulley (9) is the bevel gear (59) that meshes with the bevel gear.
a> is an output shaft constituting an output member fixed to a bevel gear, a bearing rotatably supports the bevel gear 1591 and the output shaft (59a), and h~ is a pulley. The bearing that supports the bevel gear and the bevel gear is the bearing that supports the second box body. Spur gear 2, internal gear ■, and first box body 1
1i + 9 etc., the first device, spur gear ■, (2) and bevel gear (41, t43 and pulley (c), (e) and the second box, etc., the second device, heavy double wheel , 'GI7) and pulley,
An eighth device is constituted by - and the umbrella m, - and the output shaft (59a), etc.

It should be noted that the rotational axis of the first box (1) of the first device and the rotational axis of the second box (1) of the second device intersect with each other, and the rotational axis of the second box (1) of the second device The axis and the rotation axis of the output shaft (59a) of the eighth device are perpendicular to each other. The decoy is the second link C311, the eighth link, the fourth link (711), the fourth servo mode with a reducer, and the opposite side of the fourth servo mode. The fifth servo mode with a reducer drives the link (6→1rlb), and (7 is a frame that rotatably supports the first link (641).

Next, the operation Iζ will be explained. First servo motor 71
/ (1) (7) Rotation is Boo 1 (4) , (a)
and the bevel gear a The operation of the first device is performed by rotating the .

Next tζThe rotation of the second servo mode (2) is controlled by the pulley (8).
), Ql and bevel gears QB, Qη, the signal is sequentially decelerated and the axis is changed, and is transmitted to the drive shaft.It is further decelerated and the axis is changed by the tongue and spur gear (to), C31, and bevel gears @* and @3. The operation of the second device is performed by rotating the second box 1 (g) via one wheel of the pulley θ. The rotation of the 8th servo mode (3) is by Boo IJ
Ql), the drive shaft (
c) transmission gear, bevel gear ■, f1 gear and pulley t5n
.

The operation of the eighth device is performed by sequentially decelerating and changing the axis 1 through the gear and bevel gear 2 to rotate the output shaft (59a) 1b.

Here, the first device and the second device, and the second device and the eighth device are rotating on axes that are perpendicular to each other. A workpiece (not shown) fixed to the output shaft (59, 11) by the above-mentioned first to eighth devices 1 performs a so-called wrist motion with a degree of freedom. Furthermore, the rotation of the fourth servo mode example rotates the second link o11 via the fourth link (711, ff18 link (71), and the fifth servo mode rotates the first link cho 1. do.

4th. The industrial robot performs movements with five degrees of freedom by the fifth servo mode (eg, u; 1) and the movement of the second link (3) 1 and the first link by its drive system and the above-mentioned wrist movement.

By the way, the spur gear ■, the internal gear Q, and the box body of ff11 (
The first gear consists of the spur gear end ■ and the bevel gear -
(to), a pulley (to) -, and a second box body (which is perpendicular to the axis of the second device consisting of a bevel gear) @no and a pulley 151111i rumor It is perpendicular to the axis of the eighth device consisting of a bevel gear, an output shaft (59a), etc., and in order to obtain wrist movement with 8 degrees of freedom, a large number of pulleys, spur gears, bevel gears, and bearings have to be used, which not only increases the number of parts, but also poses a risk of decreasing accuracy due to assembly errors in each part, and not only complicates the wrist area but also increases its weight. Therefore, the strength of each link that supports the wrist part must be increased, and the mounting f? There was a drawback that H became large.

[Summary of the invention]

This invention was made to eliminate the drawbacks of the conventional ones as described above, and includes a first drive shaft, a cylindrical second drive shaft concentrically surrounding the first drive shaft, and a second drive shaft concentrically surrounding the first drive shaft. A cylindrical eighth drive shaft concentrically surrounds the second drive shaft, and a first opening at one end that is coupled to the third drive shaft and can rotate concentrically with the eighth drive shaft. a box body, a second box body supported by the first box body on an axis obliquely intersecting the rotational axis of the first box body, and a second box body of the second box body; an output member rotatably supported on the second box A on an axis obliquely intersecting the axis; A transmission shaft is connected to the bottom of the box body, and the other end is driven by the second drive shaft through the first gear group, and the transmission shaft is concentric with and surrounds this transmission shaft. a cylindrical shaft; a second gear group for transmitting the rotation of the first drive shaft to one end of the cylindrical shaft; a first gear coupled to the other end of the cylindrical shaft; and a harmonic reducer whose input side is coupled to the second gear and whose output side is not coupled to the output member. It is an object of the present invention to provide a wrist device for an industrial robot that can reduce the number of parts, improve accuracy, and significantly reduce bank crash of the output shaft of the eighth device.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

In Figures 4 to 6, (a), (a), and (support) are drive shafts that transmit the rotation of bevel gear 0υ and bevel gear αη pupu 03, respectively. The drive shaft cover is inside, and the drive shaft (goods) is inside the same hollow drive shaft (goods).
The interior is triple-axed. (c), cut and (
stomach).

(B) are hollow drive shafts (A) and (C) respectively.
f+' support which supports, - is drive shaft (to) 1ζ
The first 9-box body is rotatably supported by a bearing (2).

) is a bevel gear stuck to the drive shaft plow, (foundation)
is a bevel gear that meshes with the bevel gear IQ on an axis obliquely intersecting the rotational axis of the bevel gear; ■ is a bearing that supports the bevel gear; (7)
3) is a harmonic reducer (hereinafter referred to as a reducer); (78a) is an input shaft of the reducer (731) formed in a hollow shape and is fixed to the bevel gear C3; (78b) is the reducer; It is the output shaft of ffa+, constitutes a transmission shaft, and coaxially passes through the input shaft (78a). (For example, the output shaft (
78b), the opening is the second box (the bearing that rotatably supports the drop), the umbrella 116 wheel is fixed to the drive shaft (a), and the @ force is Bevel gear (c)
A bevel gear meshing with the bevel gear f1e on the same axis as (47a)
Is this bevel gear Gl? ) is a hollow shaft fixed to the shaft, the state is this shaft.

(47a) A bevel gear coupled to one end side, - is a bevel gear that is coaxial with the bevel gear (C) and meshes with the bevel gear -, (G) is a bevel gear that is connected to the input shaft (80a). The coupled harmonic reducer (80b) is an output shaft which becomes the output side of the harmonic reducer and also serves as the output part of the wrist part, and the output shaft (80b) is a bearing that supports this output shaft (80b). □□□ is a bearing that supports the input shaft (78a), 141 is a bearing that supports the bevel gear and the shaft (47a), and 1611 (621 is a bearing that rotatably supports the boss part of bevel gear 9). be.

Here, the first box body (■) etc. is used as the first device, the bevel gear ha (c), the shaft (48a), the second box body etc. as the second device, the bevel gear OQ0η-I5 is in harmony with the luster. Reducer and output shaft (8
0b) etc.] m s device is configured.

Note that the rotation axis of the first box of the first device and the rotation axis of the second box of the second device intersect at a predetermined inclination angle,
In addition, the rotation axis of the second box body and the output shaft of the eighth device (
The rotational axes of 80b) also intersect at a predetermined angle of inclination. Note that explanations of other symbols are omitted as they are the same as in the conventional device.

In the configuration as described above, the rotation of the first servo mode (1) is sequentially decelerated and axis-converted via the pulleys (+11, (Th+) and bevel gears 0, 0Q) and the drive shaft (I). ) to rotate the first box body, and the operation of the first device is performed.The rotation of the second servo mode (21) is transmitted to the pulley (81, (1(l) and bevel gear ae
, The axis is sequentially converted through the force a and transmitted to the drive shaft @ to the bevel gear (4, the lζ axis is further converted by the trowel to resemble a bevel gear, and further the deceleration J is transmitted from the input shaft (73a)
73), the output shaft (73b) Jζ fixed second box body ((to) is rotated L7, the second device cannot operate. The rotation is transmitted to the reduction tongue drive shaft (E) via the pulley α1) and Q3, and the bevel gear 61.

(4η, M, t5!I), the harmonic reducer diagram is sequentially reduced and axis-converted and fixed to the bevel gear f59),
Further, the output shaft (80b) is rotated, and the third device cannot operate.

Here, the husband's turn II of the first, second and eighth devices
L! 1iIII lines intersect each other at a predetermined angle of inclination 1I
It is rotating on the I11 line. Workpiece (not shown) fixed to the output shaft (80a) by the first to eighth devices described above
performs a wrist motion with so-called 8 degrees of freedom.

Furthermore, by the rotation of the fourth servo mode 188) and the fifth servo mode 4, the second link G and the first link (6
1 rotates in the same manner as before, and in conjunction with the Joki hand movement, the industrial robot performs movements with six degrees of freedom. 'In addition, since the harmonic reducer iaa+ is configured with a high reduction ratio and extremely small backlash, the bevel gear 14194ηIWI 159) leading to the input shaft (soa), the drive shaft (c) and the shaft (47a) will transmit extremely low torque. Further, the backlash of the stiff transmission system can be almost ignored because the backlash of the harmonic reduction gear i8() is extremely small and the reduction ratio is extremely high.

By the way, in the explanation in Section 1, the first link 11 is rotatably supported at one end, and the second link □D is rotatably supported at the other end of this lx1 link. Although the present invention has been described with respect to an industrial robot having the present invention, it goes without saying that it can also be used for well-known rectangular coordinate type, polar coordinate type, multi-joint type industrial robots, and the like.

〔Effect of the invention〕

As described above, the present invention includes a first drive shaft, a cylindrical second drive shaft concentrically surrounding the first drive shaft, and a cylindrical second drive shaft concentrically surrounding the second drive shaft. an eighth drive shaft shaped like
a first box with an opening at one end connected to the third drive shaft and concentrically with the eighth drive shaft; an axis obliquely intersecting the rotation axis of the first box; a second box rotatably supported by the first box; the second box rotates on an axis obliquely intersecting the rotation axis of the second box; an output member that is movably supported, one end of which is coupled to the bottom of the second box concentrically with the rotation axis of the second box, and the other end of which is connected to the m2 via the first gear group; a cylindrical shaft concentrically surrounding the transmission shaft; a second gear group transmitting the rotation of the first drive shaft to one end of the cylindrical shaft; a gear Ij i coupled to the other end of the cylindrical shaft; a second gear meshed with the first gear and disposed concentrically with the output member; and an input side coupled to the second gear. , the output side is the above output member [ζ
Since the coupled harmonic reducer is biased, many pulleys and spur gears are not required, the number of parts can be reduced, and the integration error of each part can be improved, in other words, the accuracy of the device can be improved. This has the effect of reducing the weight of the parts and reducing the load on the links.

Moreover, since the harmonic reducer is placed in the final stage reduction section of the output member, the backlash of the drive system leading to the input shaft of the harmonic reducer can be ignored, and the backlash of the harmonic reducer is extremely low. Utilizing the characteristic of being small, backlash of the output member can be significantly reduced, and the operational accuracy of the output member can be significantly improved.

Moreover, the shafts and gears of the transmission system leading to the harmonic reducer only need to transmit low torque, which has the effect of making it possible to downsize the 4ilb and gears.

[Brief explanation of the drawing]

Fig. 1 is a partial cross-sectional plan view of a device that drives the wrist portion of a conventional industrial robot, Fig. 2 is a partial side cross-sectional view taken in the A top direction of Fig. 1, Fig. 8 is an overall side view, and Fig. The figure is a partially sectional side view of one embodiment of the present invention, and FIG.
FIG. 6 is a partial cross-sectional plan view taken in the direction B in the figure, and FIG. 6 is an overall side view. . (1)...first servo mode, (2)...second servo mode
(3)...Third servo mode, (A)...Drive shaft, (5)...Drive shaft, (3)...Drive shaft, (3T...Second servo mode) Link, (41UGllP's Wings of State...juryozaku, (
47a)...axis, ■...first link, fI→...first box, (scream...second box, (73) measurement...harmonic reducer, (78a, ) (80a) ・=Input shaft, (
78b) (80b) ... Output shaft. In the drawings, the same reference numerals indicate the same or equivalent parts. Agent Masuo Oiwa Figure 2 Figure 3 Figure 3 Figure 5 Figure 0

Claims (1)

[Claims] a first drive shaft; a second cylindrical drive shaft concentrically surrounding the first drive shaft; an eighth cylindrical drive shaft concentrically surrounding the second drive shaft; This eighth box is connected to the driving shaft and has an opening at one end and is rotatable concentrically with the third driving force axis, and the first box is obliquely perpendicular to the rotation axis of the first box. a second box rotatably supported by the first box on its axis; and a second box rotatably supported by the first box on its axis; A rotatably supported output member, one end of which is connected to the bottom of the second box concentrically with the rotational axis of the second box, and the other end of which connects the first gear group. a cylindrical shaft concentrically surrounding the transmission shaft, a second shaft that transmits the rotation of the first drive shaft to one end of the cylindrical shaft; a gear group, a first gear coupled to the other end of the cylindrical shaft, a nail meshed with the first gear, a second gear disposed concentrically with the output member, and the second gear. A wrist device for an industrial robot comprising a harmonic reduction gear A whose input side is connected to the gear of the invention and whose output side is connected to the output member.