JPH0569376A - Arm driving device - Google Patents

Abstract

PURPOSE:To provide an arm driving device equipped with a enhance assembly accuracy and a mechanical rigidity. CONSTITUTION:A single motor shaft 2 is fixed to as bracket 1, and motor housings 7, 8 constituting the first and second motors 5, 6 are supported rotatably on the motor shaft 2, and a link mechanism 25 equipped with an arm member 26 is coupled rigidity with these motor housings 7, 8. Thus an arm driving device is formed. The motor driving force given when motor driving power supply is applied, rocks the link mechanism 25 with rotation of the motor housings 7, 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an arm driving device, and can be suitably used for a driving device such as a robot arm.

[0002]

2. Description of the Related Art Conventionally, various drive devices for causing a robot arm to perform a predetermined operation have been proposed. 2 to 4 show an arm drive device of a type in which a working arm is driven by a motor via a link mechanism. In these drawings, the arm drive device 20 includes a pair of first and second motors 22A and 22B provided on a bifurcated support bracket 21 and the motors 22A and 2B.
The link mechanism 25 is fixed to the 2B motor shafts 23A and 23B, and is oscillated by the rotational driving of the motor shafts 23A and 23B, and the arm portion 26 integrally provided on the link mechanism 25. ing.

The first and second motors 22A, 22
As shown in FIG. 4, B is arranged such that the motor shafts 23A and 23B are located on the same axis, and the link side 25A of the link mechanism 25 is provided at the tip of each motor shaft 23A and 23B. , 25B
Each end is connected. The motors 25A and 25B are respectively provided with housings 30A and 30B integrally formed with the support bracket 21. Reference numerals 31A and 31B in FIG. 4 are stators, 32A and 3A.
2B shows a rotor.

The link mechanism 25 includes a link side 25A,
In addition to 25B, two link sides 25C and 25D are connected to each other via a pin or the like to be assembled. One end of the link side 25C is further extended outward so that the arm portion 26 is integrally formed. It is configured to be provided. This arm part 26
The finger member 2 for performing a predetermined work is attached to the tip of the finger.
7 is attached.

In the above conventional structure, the first and the second
When the motors 25A, 25B are operated to rotationally drive the motor shafts 23A, 23B, the link mechanism 25 connected to the motor shafts 23A, 23B follows the drive amount of the motor shafts 23A, 23B, The position of the finger member 27 can be displaced by a predetermined distance by moving along a preset locus.

[0006]

However, the arm drive device having the conventional structure has the following problems.

That is, as described above, the motor shafts 23A and 23B are respectively connected to the motors 25A and 25B.
It is difficult to maintain the coaxial precision with high precision because it is provided corresponding to the above and is arranged on the same axis line, and eventually the precision of the movement locus of the finger member 27 is lowered. Further, precision adjustment requires considerable skill, which not only prolongs the assembling work but also requires high-precision machining of the components themselves.

Further, since the link mechanism 25 is connected to the motor shafts 23A and 23B, the mechanical rigidity is insufficient.

[0009]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to eliminate the cause of the accuracy deterioration in the above-mentioned conventional example, to facilitate the processing of the constituent parts, and to improve the mechanical rigidity. An object of the present invention is to provide a durable motor drive device.

[0010]

In order to achieve the above object, the present invention provides a pair of motors arranged coaxially with each other, a link mechanism connected to these motors, and an arm equipped to this link mechanism. An arm driving device for driving the arm in a predetermined manner through a link mechanism by driving the motor, the motor shafts constituting the pair of motors are constituted by a single motor shaft, and the motor shafts are fixedly arranged. In addition, the motor housing side is configured to be rotatable, and the link mechanism is connected to the motor housing.

[0011]

When a predetermined power source is turned on to drive the motor, the motor shaft is fixedly mounted on the bracket, so that the motor shaft is not rotationally driven and a rotational force is applied to the motor housing. As a result, with the rotation of the motor housing, the link mechanism connected to the motor housing performs a predetermined operation, and the arm portion moves on a predetermined movement locus.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. The same reference numerals are used for the same or equivalent components as those of the conventional example, and the description will be omitted or simplified. FIG. 1 shows a cross-sectional view of an essential part substantially corresponding to FIG. 4 in the above-mentioned conventional structure. In this figure, the support bracket 1 does not have a bifurcated structure, but is provided with a protruding portion 1B protruding upward from the upper surface of the base portion 1A. A through hole 1C is provided on the upper end side of the protruding portion 1B in the left-right direction in the drawing. One motor shaft 2 is fixed to the support bracket 1 while being inserted into the through hole 1C.

Motor housings 7 and 8 constituting first and second motors 5 and 6 are rotatably supported on the left and right sides of the motor shaft 2 along bearings 4 along the outer circumference of the motor shaft 2. ing.

One end sides of link sides 25A and 25B forming a link mechanism are connected to the facing surfaces of the motor housings 7 and 8 in the upper part in the figure via fixing screws 10 and 11, respectively. The other structure is substantially the same as that of the conventional example.

In the above-described structure of this embodiment, when the motor driving power source (not shown) is turned on, the rotational driving force acts on the motor shaft. However, as described above, since the motor shaft 2 is fixedly supported by the support bracket 1, the motor shaft 2 is not rotationally driven. Therefore, the rotational force of the motor shaft 2 is located on the outer periphery of the motor shaft 2 via the bearing 4. 7 and 8 will be given.

The motor housings 7 and 8 include link sides 2
Since 5A and 25B are connected, when the motor housings 7 and 8 are rotationally driven, the link sides 25A and 25B also move together with the corresponding motor housings 7 and 8,
As a result, the entire link mechanism 25 is displaced. When the link mechanism 25 is displaced in this way, the finger member 27 provided on the arm member 26 is also displaced at the same time, and as a result, the finger member 27 is displaced on a predetermined locus by driving the motor.

According to such an embodiment, the motor shaft 2 is made of a single member, and the motor shaft 2 is fixed to the bracket 1, so that the swinging of the link mechanism 25 can be prevented. 7, 8
It is possible to perform by using the
It is possible to solve the difficulty of disposing the two motor shafts on the same axis with a simple structure, and to realize highly accurate displacement of the finger member 27.

Further, the support bracket 1 does not have a bifurcated structure, but is provided with a projecting portion 1B and supports the motor shaft 2 in a through hole 1C projecting from the projecting portion 1B. The shape can be simplified compared to
Moreover, there is an effect that high precision machining can be performed more easily.

Further, since the link sides 25A and 25B are integrally fixed to the motor housings 7 and 8 by screws, it is expected that the link sides 25A and 25B have higher rigidity than the conventional example, and the durability is improved. You can

Further, reduction of the number of expensive parts such as the motor shaft 2 which requires high-precision machining makes it possible to reduce the manufacturing cost of the entire apparatus, reduce the number of assembling steps, and reduce accuracy error. It is more advantageous in avoiding it.

In the present invention, the motor shaft 2 is fixed and the motor housings 7 and 8 are rotated. As long as such operation is possible, the support structure for the motor shaft 2 and the motor housings 7 and 8 is provided. Also, the shapes of the motor housings 7 and 8 are not limited to the illustrated configuration examples, and various design changes can be made.

In addition, in the above description of the embodiment, the example mainly used for driving the robot arm has been described, but the present invention can be suitably used as the structure of a general mechanical device having a link mechanism. ..

[0023]

The present invention is constructed as described above, and
According to this, a single motor shaft 2
It is possible to eliminate the coaxial arrangement work, which is a cause of deterioration in accuracy in the conventional example that employs two motor shafts, by using the motor housings 7, 8 and the link sides 25A, 25B.
There is an effect that the mechanical rigidity can be increased by connecting with and the assembling accuracy can be improved by reducing the number of parts.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of essential parts showing an embodiment of a motor drive device according to the present invention.

FIG. 2 is an overall perspective view showing a conventional structure of an arm drive device.

FIG. 3 is a side view showing a conventional structure of an arm driving device.

FIG. 4 is a sectional view similar to FIG. 1, showing a main part of the conventional structure.

[Explanation of symbols]

 1 Support Bracket 2 Motor Shaft 5 First Motor 6 Second Motor 7, 8 Motor Housing 25 Link Mechanism 25A, 25B, 25C, 25D Link Side 26 Arm Member 27 Finger Member

Claims (1)

[Claims] 1. A pair of motors arranged coaxially with each other, a link mechanism connected to these motors, and an arm portion mounted on the link mechanism, and driven by the motors via the link mechanism. In an arm drive device for operating an arm in a predetermined manner, the motor shafts constituting the pair of motors are constituted by a single motor shaft, the motor shafts are fixedly arranged, and the motor housing side is rotatably constituted. An arm drive device characterized in that the link mechanism is connected to a housing.