JPS60232894A - Wrist mechanism in automatic machine - 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 [Field of Application of the Invention] The present invention relates to a wrist mechanism in an automatic machine such as a robot.

[Background of the invention]

Industrial robots are widely used for painting work, welding work, etc., and are especially effective when working in harsh atmospheres. Furthermore, in this type of robot, the wrist mechanism is one of the keys to determining the effectiveness of the robot's work.

Figures 1 and 2 show the wrist mechanism of a conventional robot of this type. As shown in the figure, a bevel gear 12 is fixed to the tip of a central shaft 11 of the triple shafts that rotate coaxially. A configuration in which rotational force is transmitted from this bevel gear 12 to a bevel gear 15 that rotates around the bending shaft 1A via a bevel gear 16 rotatably supported by the bending shaft 11, thereby driving the twist shaft 16. It's Toshide. On the other hand, bending axis 1
4 has a configuration in which driving force is transmitted from an h7 bevel gear 22 fixed to the tip of an intermediate shaft 21 of the triple shaft, and driven via a bevel gear 23 fixed to the bending shaft 11. Reference numeral 16 is a twist shaft that meshes with the bevel gear 15, to which work parts such as a VC coating nozzle or a welding torch are attached.

24 is a cover attached to the outside of the bearings 47, 48 of the twist shaft 16; 42. A5. /iA, 46 are bearings attached to the center @111 bending shaft 14, respectively. 32 is a gear case that covers these gears, shaft tips, bearings, etc.

The entire wrist is rotated by a triple-shaft outermost shaft 31 fixed to a gear case 32. The bending shaft 14 is rotatably supported on a bearing support 33 that projects from the inner wall of the gear case 32 in a cantilevered manner.

Furthermore, since the cover 2A surrounding the twisting shaft 16 rotates together with the bending shaft 14, a notch 24a is formed to prevent the cover 24 from interfering with the gears, shafts, etc.

According to the structure shown in FIGS. 1 and 2, there is a problem when it is desired to increase the weight of the wrist load. Since it is supported by a6, it is difficult to ensure the necessary rigidity for the wrist. In order to extend the life of a bearing, the structure of that part must be made thicker, but according to this, the bending axis 1
40 The diameter of the bearings at both ends is large, and due to the structure, it is natural that the bevel gear 13, 23 and bearing 43 are inserted into the bending shaft 14.
,．． There were problems such as the inability to incorporate 114 and the like.

Further, since the cover 24 surrounding the wrist 16 is provided with a notch 24a, it is necessary to cover the wrist with a bellows type cover or the like to prevent internal gears from being exposed.

In this way, wrist mechanisms used not only in industrial robots but also in robots of this type must be able to withstand adverse environmental conditions such as heat and arm spatter in order to ensure workability. Ta.

Also, since there is a possibility of contact with the workpiece during work,
Flexible covers such as bellows, which deform unstably depending on the posture of the wrist, were not suitable for practical use.

[Purpose of the invention]

The present invention has been made in view of the problems in the prior art mentioned above, and has high rigidity at the wrist, and can withstand harsh environments by forming part of the cover covering exposed parts such as gears with a rigid cover. To provide a robot wrist mechanism.

[Summary of the invention]

The wrist mechanism for an automatic machine according to the present invention has a central shaft connected to a drive source, an intermediate shaft provided so as to cover the outer periphery of the central shaft, and an outer shaft provided so as to further cover the outer periphery of the central shaft. a triple shaft for supporting the central shaft; a first bevel gear attached to the tip of the central shaft; a second bevel gear attached to the tip of the intermediate shaft; and a wrist mechanism that meshes with the second bevel gear. The song consists of a two-stage bevel gear that rotates around an axis and consists of a large-diameter bevel gear that meshes with the first bevel gear, and a small-diameter bevel gear that meshes with the twist shaft bevel gear attached to the tip of the wrist. , and a rigid cover that covers exposed parts such as these bevel gear parts and the bending shaft.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described in detail with reference to FIGS. Also in FIG. 3, the three coaxially rotating axes include a twisting axis 51 which is the central axis and a bending axis 6 which is the intermediate axis.
1. It consists of an outer shaft 71 that rotates the entire wrist, and is connected to a drive source of an automatic machine (not shown). A first bevel gear 52 is attached to these twisting shafts 51, and a bending shaft 61v
In C, the second bevel gear 62 is attached. 72 is a gear case attached to the outer shaft, in which a bending shaft 55 is installed.
, a gear train for driving the twisting shaft 57, etc. are housed, and bearings 85 and 86 for supporting the bending shaft are provided on both side walls of the gear case 720. The bending shaft 551C is for driving a bending shaft, and has a fixed third bevel gear 63 that meshes with the bevel gear 62, and is rotatably supported by two-stage bevel gears 53 and 51 for driving a twisting shaft. .

In the two-stage bevel gear having these bevel gears 53 and 54, one bevel gear 53 has a large diameter and meshes with the first bevel gear 52, and the other bevel gear 54 has a large diameter and meshes with the first bevel gear 52.
It is integrated with 3 and has a small diameter, and has a twist shaft 57.
It meshes with the bevel gear 56.

Therefore, the twisting shaft 57 is housed in a twisting shaft support case 6AMC fixed to both ends of the bending shaft 550 so as to enclose the gears 72, and is attached to be rotatable around the bending shaft 55. Further, the first bevel gear 52 is a bevel gear provided at the tip of the twist shaft 51, and meshes with a bevel gear 53, which is a two-stage bevel gear. A bevel gear 56 is formed at the inner end of the twist shaft 57, and the other bevel gear (small diameter one) 54 of the two-stage bevel gear meshes with it.

Figure 4 is a cross-sectional view when viewed from the direction of arrow A in Figure 3, and Figure 5 shows the state with the cover attached, but as shown in these figures, the gear Rigid covers 65 and 73 are fixed to the twist shaft support case 64 and the gear case 72 with screws 65a and 73a to cover the exposed parts.

Note that 81 to 88 are @ receiving parts provided in each rotating part.

In this embodiment, as shown in the figure, a support bearing 85.
86 is provided on both side walls of the gear case 720, so if a large size bearing is required, such as when increasing the wrist load, the large size bearing can be easily installed on the wall. It becomes possible to do so. Also,
A twist shaft 57 is installed in a twist shaft support case 64 that is fixed to both ends of the bending shaft 550 so as to wrap around the gear case 72.
Since the wrist weight is accommodated, it is possible to sufficiently secure the rigidity required as the wrist load increases.

Of the gear train that drives the twisting shaft 57, the bending shaft 5
Since the gear supported by 5IIC is composed of two-stage bevel gears 53 and 54, the twist shaft 57 can be bent and the shaft 5 can be bent without interference between the twist shaft support case 64 and the gears, shafts, etc.
5, and exposed parts such as gears can be covered with rigid covers 65 and 73. FIG. 5 shows the condition, and it can withstand use under adverse conditions.

〔Effect of the invention〕

As is clear from the above-described embodiments, according to the present invention, parts can be easily changed when the load on the wrist increases, sufficient rigidity of the wrist can be ensured, and exposed parts such as gears can be easily replaced. 6E') with a rigid cover, which has the advantage of being able to withstand use in adverse environments.

[Brief Description of the Drawings] Figures 1 and 2 are diagrams for explaining the wrist mechanism of a conventional robot, with Figure 1 being a vertical sectional view showing its internal configuration, and Figure 2 being A plan view showing a state in which the cover is turned over;
3 to 5 are diagrams for explaining one embodiment of the present invention, in which FIG. 3 is a longitudinal sectional view showing the internal structure, and FIG. 4 is a view taken from the direction of the arrow in FIG. 3. FIG. 5 is a plan view showing a state in which the cover is attached. 53.54...2-stage bevel gear, 55...Bending shaft, 5
2.56, 62.63...Bevel gear, 57...Twist shaft, 61.71...Rotation drive shaft, 64...Twist shaft 1st mouth ? ■ 1 3121 ↓A $ 4 Figure door 5 Figure 7 7J 64

Claims (1)

[Claims] A wrist mechanism in an automatic machine such as a robot, which includes a central shaft connected to the drive source of the automatic machine, an intermediate shaft provided like a cypress on the outer periphery of the central shaft, and an outer side provided so as to cover the outer periphery. a triple shaft for supporting the wrist mechanism; a first bevel gear attached to the tip of the central shaft; a second bevel gear attached to the tip of the intermediate shaft; a third bevel gear that meshes with the bevel gear and rotates the bending axis of the wrist mechanism; a bevel gear formed on the outside of a large diameter that rotates around the bending axis and meshes with the first bevel gear; Consists of a two-stage bevel gear consisting of a small-diameter inner bevel gear that meshes with a bevel gear formed inside a twisting shaft attached to the tip of the wrist, and a rigid cover that covers exposed parts such as these bevel gears and the bending shaft. A wrist mechanism in an automatic machine characterized by: