JPS62241689A - Robot arm - 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 The present invention relates to an arm for an industrial robot, and more particularly to a robot arm in which a motor of a novel configuration that effectively utilizes the arm shank is integrally installed in the internal space of the arm.

Industrial robots, which are generally used for purposes such as factory automation, have one arm or several arms connected together, and each joint of this arm is connected to the output shaft of a reducer coupled to a motor. It is configured to drive the arm. Normally, the arm drive motor is DC.
Servomotor.

Rotary motors such as AC servo motors are used, but
In order to turn a heavy arm and drive a load, it is necessary to use a large motor that generates high torque and a reduction gear. Conventional robots are inevitably large and heavy, and also have joints. It also had the disadvantage of being locally large and visually lacking in smartness.

On the other hand, in recent years, robot control has become more precise.

Research into direct drive, which directly drives the arm with the shaft output of the motor, without the use of a reducer, which can cause backlash, decrease in rigidity, and deterioration in positioning accuracy due to the advancement of high-speed and high-torque drives. A 1m launcher has been promoted, and various motors suitable for this mechanism have been proposed. The important performance required of the motor to implement this direct drive is a maximum of 100 (r.p, II
1) Generation of large torque and small inertia in a relatively low speed region. The direct drive motors that have been proposed in the past have a configuration in which the rotor surface area is increased to increase torque, that is, a rotor with a large diameter and a stiff and narrow configuration, or an outer structure in which the rotor is located outside of the stator. It had a rotor-type configuration. However, if the rotor itself is simply made larger like this, the torque increases, but the motor itself becomes heavier and larger, and the rotor volume also increases, which increases inertia, which is disadvantageous when performing high-speed precision control. It has some defects and gaps, and cannot be said to have a structure that is necessarily suitable for use as a robot arm drive motor. Also, the larger the motor, the more r! ! The shape of the s part was designed to increase the overall weight of the robot without losing its smartness. There were also problems with restrictions such as location and space.

The present invention has been made to improve the above-mentioned drawbacks, and aims to provide a robot arm in which a motor of a new configuration that can generate an extremely large torque even in a low-speed rotation range is integrated into the arm. A further object of the present invention is to provide a robot arm that enables direct drive in which the arm is directly driven by the output of an internal motor.

A further object of the present invention is to provide a robot arm in which the main body of the robot arm can be used as a motor arm, and the number of parts and weight can be significantly reduced.

Furthermore, the present invention has a newly configured motor integrated into the robot arm, which makes it possible to create a robot arm that is lightweight, smart, and has good controllability, and is also cost-effective due to the ability to significantly reduce the number of parts. The purpose is to provide.

Examples of Pt5l according to the present invention are shown in FIGS. 1 to 3 below.
This will be explained in detail with reference to the drawings. In the figure, (1) shows a robot, for example, an S CAR RA (horizontal articulated) type robot. This robot (1) has a first robot arm (2) and a second robot arm (3).

The first arm (2) is connected to a column (5) fixed to the base (4). Further, the second arm (3) is connected to the first arm (2), and has a wrist arm (7) having a chuck (6) at its end.
) is installed. The robot arm (2) includes an arm body (8) having an internal space, and an arm body (8) having an internal space.
8) as a housing and a motor (10) integrally installed in the internal space of the housing. This motor (10
) is a driving wheel-shaped body (1) disposed at one end of the internal space.
1), an idle ring-shaped body (12) arranged at the other end, a belt-shaped rotor (13) installed between these two ring-shaped bodies (11) and (12), and a straight ring of this belt-shaped rotor (13). Four stators (14) arranged near the #1 section, (14),
It consists of (14) and (14). The driving wheel-like body (11) is attached directly to the pongee (15) of the support column (5), and external teeth (16) are formed on its outer periphery. (12) is attached to a pongee (18) provided on the arm body (8) via a bearing (17) so as to idle without resistance.

The belt-shaped rotor (13) has straight parts (19), (19) and curved Al11 parts (20), (2), which have different structures and materials.
0), and each connected bin (21,), (21)
are connected in an oval shape. Said shift #i department (19)
, (19) are formed, for example, in a plate-like body made of laminated silicon steel plates, and near the surface there are a plurality of conductor rods (22), (22), (2) made of, for example, aluminum.
2),... are buried at predetermined intervals. The song #afflS (20) is the song #afflS (20), which includes the annular body (1
1) It is formed of a flexible member such as a material for polymer synthesis, rubber, or soft plastic so as to flexibly follow the curved surface. Moreover, this flexible curved part (20) and the ring-shaped body (11) are constructed in a so-called timing belt structure, and the inner periphery of the curved part (20) is provided with the outer part of the ring-shaped body (11). Internal tooth (2) of the same pinch that meshes with tooth (16)
3) is formed. The stator (14), (1
4), (14), and (14) are the belt-shaped rotor (1
3), the straight portions (19) and (19) are disposed over substantially the entire length thereof, with a slight gap between them. This stator (14) is connected to a control device (not shown),
For example, it is formed of a laminate of silicon steel plates, and inside it there are induction windings (24), (24), (24), etc.
are wound at predetermined intervals.

Next, the operation of the above configuration will be explained. Stator (14).

Conductor rods (22) embedded in the straight parts (19), (19) of the strip rotor (13) by energizing (14), (14), (14).

An induced current is generated in the straight parts (19), (1
9) starts moving in the left-right direction in the drawing, and along with this movement, the flexible curved portion (20) rotationally drives the ring-shaped body (11). This ring-shaped body (11) is the pillar (5) of the robot (]).
) Since it is directly connected to the pongee (15) of the robot arm (2), the rotation of this ring-shaped body (11) directly drives the robot arm (2) to turn.

Next, a second embodiment of the robot 7-m of the present invention will be explained in detail with reference to drawings 4 to 7, in which the same parts as in the first embodiment are denoted by the same reference numerals. The explanation will be omitted. In the figure, (3o) is a belt-shaped rotor. This belt-shaped rotor (30) has a plurality of independent r! (32), (32) have. Timing bell of this belt rotor (30)) (
32) is installed over the ring-shaped body (33) and the other ring-shaped body (not shown). The independent piece (31) that records 11 is
For example, it is formed by laminating silicon copper plates, as shown in Figure 7 (
As shown in A), near both surfaces there are conductive rods (34), (34), etc. made of aluminum, for example.
... is buried. Moreover, this independent piece (31) is rotatably attached to the timing belts (32), (32) via a connecting pin (35), as shown in FIG. 7(B). The annular body (33) is connected to a drive shaft (36) as shown in FIG. 4, and external teeth (37) are formed on its outer periphery to mesh with the timing bell (32). As shown in FIG. 6, the independent piece (31) has adjacent pieces touching each other at its straight parts (38) and (38) to form a single plate-like body, and at its curved part (39). The shape is determined so that it follows the curved surface of the annular body (33) and rotates without mechanical contact friction resistance. That is, a 1/4 circle having a radius equal to the thickness is formed flat at both ends, and the connecting pin (35) is positioned at 172 of the piece's height.

Next, the performance of the above configuration will be explained. Stator (14).

(14), (14), and (1, 4) are energized, each independent piece (31) is located in the straight portion (38), (3B) of the strip rotor (30).

(31), ...... conductor rod (34), (34
), . . . , an induced current is generated, and the belt-shaped rotor (30) starts moving in the left-right direction in the drawing in accordance with a command from a control device (not shown).

The operation of this belt-shaped rotor (30) is performed as shown in FIG. In other words, in the straight part, the stator (1
Each independent piece (31) is excited by the induced current of 4) and (14) and becomes an independent magnet, and adjacent independent pieces come into surface contact with each other and become substantially similar to one plate-shaped body. On the other hand, each independent piece (31), (31) of this belt-shaped rotor (30)
. . . enters the curved portion (39) and moves away, following the curve of the annular body (33) with almost no mechanical contact resistance or frictional resistance. At this time, the power of the band rotor (30) is transmitted to the ring body (33) via the timing bell (32) and then to the drive shaft (36). This rotation of the drive shaft (36) causes the robot 7-arm (2
) is driven in rotation.

Incidentally, in each of the above embodiments, a structure in which the stator is disposed at the diametrical portion of the strip-shaped rotor has been described, but the invention is not limited to this, and the stator is arranged over the entire length of the strip-shaped rotor. may also be,
The VT configuration of the motor and the power transmission means are not limited to the embodiments, and any configuration may be used as long as it does not depart from the gist of the present invention.Furthermore, as a robot to which the present invention is applied, Although the explanation has been given using a horizontal multi-m-axis robot as an example, the present invention may also be applied to a vertical multi-m-articulated robot. In this case, if the motor has an induction type electric drive structure as in the example, even if gravity fluctuations occur due to the vertical rotation of the robot arm, the drive current will automatically increase or decrease due to the characteristics of the motor, so gravity fluctuations will be handled specially. Compensation is provided without the need for additional equipment.

As is clear from the above explanation, according to the present invention, by integrally installing a motor of a new configuration in the internal space of the robot arm, a lightweight and smart robot arm that drives the arm itself can be obtained. be able to. Furthermore, by effectively utilizing the arm length, the stator arm can be made longer, so the effective rotor surface area can also be increased, making it possible to generate extremely large torque.

Therefore, it has the effect of enabling a direct drive in which the arm is directly driven by the output of the motor.

Moreover, especially if the robot arm main body is used as it is as a motor mechanism as in the embodiment, it is possible to obtain a robot arm in which the number of parts and the number of bases are significantly reduced.

Furthermore, if the straight part and curved part of the strip rotor are made of different materials and structures as in the example of fjSl, only a limited turning range can be obtained, but the magnetic flux efficiency and current efficiency of the straight part are It has excellent practical effects, such as being extremely good and being relatively easy to manufacture. Further, as in the second embodiment, if the belt-shaped rotor is configured such that the independent sides are connected in an infinite orbital manner, it is possible to obtain excellent versatility without limiting the turning range.

[Brief explanation of drawings]

FIG. 1 shows a perspective view of a SCARA type robot using the robot arm of the present invention, FIGS. 2 and 3 show a first embodiment of the robot arm of the present invention, and FIG. 2 is a cross-sectional view thereof. FIG. 3 shows an enlarged sectional view of the same main part. Figure 4 to IjS
FIG. 7 shows a second embodiment of the robot arm of the present invention, FIG. 4 is a cross-sectional view of the main part thereof, FIG. 5 is a longitudinal cross-sectional view taken along the line V-V in FIG. 7 (A) is an enlarged sectional view of the independent side, (B)
shows a sectional view taken along line bb in (A). (1) ...Robot, (2>, (3> ...Robot arm, (8)
... Arm body, (10) ... Motor, (11), (12) ... Ring-shaped body, (13) ...
...Striped rotor, (14), (14), (14), (
14)... Stator, (19), (19)...
...Straight section, (20), (20)...Curved section,
(22), (22), ・・・・・・・・・Conductor rod, (
24), (24),...Induction winding,
(30)...Band-shaped rotor, (31), (31),...Independent side,
(33)... ring-shaped body,

Claims (2)

[Claims] (1) An arm body having an internal space, a ring-shaped body installed inside the arm body and disposed at substantially both ends of the internal space, a belt-shaped rotor installed in the ring-shaped body, and the vicinity of the straight part of the belt-shaped rotor 1. A robot arm comprising: a stator disposed in a stator; and a motor having a stator. (2) The robot arm according to claim 1, wherein the arm body is a motor housing.