JPH0349715B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement of an arm drive mechanism for an industrial robot device.

[Prior Art] First, a conventional power transmission means of a gear-driven robot arm will be explained with reference to FIGS. 2a and 2b. Second
Figure a is an internal structural diagram of the robot arm showing the driving means for the robot arm. In the figure, 1 is an input-side gear that is fitted and fixed to the input shaft 2 and rotates as the input shaft 2 rotates, and 3 is fitted and fixed to the output shaft 4 that is a support shaft and meshes with the input-side gear 1. This is a rotatable output gear, and the number of teeth of the output gear 3 is greater than the number of teeth of the input gear 1 for deceleration.

Note that the axial directions of the input shaft 2 and the output shaft 4, which is a support shaft, are perpendicular to each other. Reference numerals 5 and 6 denote bearings using a bearing or the like, which rotatably support the input shaft 2 and the output shaft 4, respectively, and are fixed to the input arm 7 of the industrial robot device. The input shaft 2, the input gear 1, the output gear 3, the bearing 5, a part of the bearing 6, a part of the output shaft 4, etc. are housed inside the input arm 7. Reference numeral 8 designates an output side arm that is integrally fixed to the output shaft 4 and swings around the axis of the output shaft 4 as the output shaft 4 rotates.This output side arm 8 is an input side arm. It is pivoted on 7. These input side gear 1, input shaft 2, output side gear 3, output shaft 4, bearings 5, 6, input side arm 7, and output side arm 8 constitute an arm system 9. Further, a gear mechanism 10 is constituted by two gears, an input side gear 1 and an output side gear 3.

In the figure, the input shaft 2, input side arm 7, part of the output side arm 8, etc. are omitted.

The power transmission means of a gear-driven robot arm in a conventional industrial robot device is configured as described above, and when the input shaft 2 is rotated by power from a power source (not shown) and the input side gear 1 is rotated, The output gear 3 meshed with the input gear 1 rotates while being reduced in speed according to the reduction ratio of the gear, and the torque is increased in accordance with the reduction ratio. As the output side gear 3 rotates, the output side arm 8 which is integrally fixed to the output shaft 4 via the output side 4 swings, whereby the output side arm 8 is connected to the input side arm 7. In contrast, the required relative position and relative angle will be obtained.

Therefore, the driving force is transmitted from the input arm 7 via the gear mechanism 10 to the output arm 8 which is pivotally supported by the input arm 7.

[Problems to be Solved by the Invention] It is generally desired that the robot arm of an industrial robot device be thin in shape to avoid interference with peripheral devices. In the power transmission means, since the joint between the input side arm 7 and the output side arm 8 is driven from only one side, a large load torque is applied to the output side gear 3. As a result, the output side gear 3
is large, and the input arm 7 that accommodates it must also be large, which poses a problem in that miniaturization of the joints of the robot and the shape of the arm system 9 is restricted.

Furthermore, since it is of a cantilever type in which the output shaft 4 is supported only by the bearing 6, there is also the problem that the rigidity is weak and failures are likely to occur.

The present invention solves the above-mentioned problems and aims to provide an industrial robot device having a robot arm with a narrow arm shape under the same arm system load conditions.

[Means for Solving the Problems] An industrial robot device according to the present invention includes a robot arm that transmits driving force to an output arm that is pivotally supported by an input arm via a gear mechanism.
The input side arm is provided on both sides of the output side arm so as to be pivotally supported across the output side arm, and
A gear mechanism for transmitting driving force to the support shaft of the output arm is separately provided on the input arm on both sides of the output arm.

[Function] In this invention, the output side arm is supported on both sides, and the support shaft is driven by a gear mechanism provided separately on both input side arms, so the gear mechanism can be miniaturized. As a result, the shapes of the robot joints and arm system can be made smaller.

[Example] Hereinafter, an example of the present invention will be described with reference to FIGS.
This will be explained with reference to b. FIG. 1a is an internal structural diagram of the robot arm showing the driving means for the robot arm. In the figure, 1a and 1b are input side gears that rotate with the rotation of input shafts 2a and 2b, respectively, and 3a and 3b are input side gears 1a and 3b, respectively.
It is a rotatable output side gear which is fitted and fixed to output shafts 4a and 4b which mesh with the output side gears 1b and are support shafts, and the number of teeth of each of the output side gears 3a and 3b is equal to the number of teeth of the input side gears 1a and 1b. It slows down by increasing the number.

Note that the axial directions of the input shaft 2a and the output shaft 4a, and the input shaft 2b and the output shaft 4b are perpendicular to each other, and the axes of the output shafts 4a and 4b are aligned. 5a, 6
a is a bearing using a bearing or the like that rotatably supports the input shaft 2a and the output shaft 4a, respectively;
Similarly to the bearings 5a and 6a, the bearings b and 6b are also bearings that rotatably support the input shaft 2b and the output shaft 4b, respectively. Reference numeral 7a designates an input side arm of one of the robot arms of the industrial robot device, and includes an input shaft 2a and an input side gear 1.
A gear mechanism 1 composed of a and an output gear 3a
0a, a bearing 5a, a part of the output shaft 4a, a part of the bearing 6a, etc. are housed inside, and the bearings 5a and 6a are fixed.

On the other hand, 7b is one input side arm of the robot arms whose configuration is symmetrical to this input side arm 7a, and includes an input shaft 2b, a gear mechanism 10b composed of an input side gear 1b and an output side gear 3b, and a bearing. 5b, a part of the output shaft 4b, a part of the bearing 6b, etc. are housed inside, and the bearings 5b and 6b are fixed.
A robot arm 8 is integrally fixed to the output shafts 4a, 4b, which are support shafts, and swings around the axes of the output shafts 4a, 4b as the output shafts 4a, 4b rotate. It is one of the output side arms, and is pivotally supported by the input side arms 7a and 7b from both sides. These input side gears 1a, 1b,
Input shafts 2a, 2b, output gears 3a, 3b, output shafts 4a, 4b, bearings 5a, 5b, 6a, 6b, input arms 7a, 7b, and output arm 8 constitute an arm system 9. .

In addition, the gear mechanism 10a is operated by two gears, the input side gear 1a and the output side gear 3a, and the input side gear 1b
The gear mechanism 1 is made up of two gears: and the output side gear 3b.
0 respectively, and output shafts 4a, which are support shafts,
4b, the number of gears is not limited to two, and may be a gear train using three or more gears. In addition, Fig. 1 a and b are as follows.
Input shafts 2a, 2b, input side arms 7a, 7b, part of output side arm 8, etc. are omitted from illustration.
Moreover, the reduction ratios of the input side gear 1a and the output side gear 3a, and the input side gear 1b and the output side gear 3b are completely the same. Therefore, it is desirable that the input side gears 1a, 1b have the same number of teeth, and the output side gears 3a, 3b have the same number of teeth.

Next, the operation of the above-described embodiment configured as above will be explained. Due to the power from a power source (not shown), the operation timing, rotational speed, and rotational acceleration completely match and synchronized rotation in the opposite direction (for example, the first
When the input shafts 2a, 2b are rotated in the opposite direction by rotating the input gears 1a, 1b in the opposite direction, the output gears 3a, 3a, 3b meshing with the input gears 1a, 1b, 3b is decelerated in accordance with the reduction ratio of the gear and rotates in the same direction at the same speed, and the torque is increased in accordance with the reduction ratio. Through the rotation of the output side gears 3a, 3b, the output shafts 4a, 4b, which are support shafts, are rotated.
The output side arm 8 which is integrally fixed to the input side arms 7a and 7b swings, whereby the output side arm 8 obtains a required relative position and relative angle with respect to the input side arms 7a and 7b.

Therefore, the load on the arm system 9 configured as shown in FIGS. 1 a and b is distributed to the gear mechanisms 10 a and 10 b of the arm system 9 configured as shown in FIGS. 1 a and b, and the load on the arm system 9 configured as shown in FIGS. Gear mechanism (1 in Figure 2 a, b)
Each gear can be made smaller compared to 0). moreover,
When each gear 1a, 1b, 3a, 3b is a reduction gear that generates thrust force during driving, such as a spiral bevel gear, the teeth of the output gears 3a and 3b may be twisted. Select the directions appropriately, and turn the input side gears 1a, 1.
By matching b to this value, the thrust forces can be canceled out, and as a result, the bearings 6a and 6b can be made smaller.

In addition, in the above embodiment, each gear 1a, 1b, 3
Although a reduction mechanism using a bevel gear with curved teeth has been described as a and 3b, it is obvious that similar actions and effects can be obtained by a reduction mechanism using a trochoid gear, a worm gear, or the like.

Further, in the above embodiment, the case where the output shafts 4a and 4b are provided on the output side of the output side gears 3a and 3b, respectively, has been described, but the output shafts 4a and 4b are
The output side arm 8 may be fitted and fixed to this shaft as a single shaft.

Furthermore, although the gear mechanisms 10a and 10b are assumed to constitute a speed reduction mechanism, the same effect as described above can be obtained by configuring a speed increasing or the same speed mechanism by appropriately selecting the number of teeth of each gear mechanism. It will be done.

By the way, the means for supporting the output side arm 8 has conventionally been a cantilever type in which it is supported by only one bearing (bearing 6 in Fig. 2a), but in this invention, two Since it is supported by the bearings 6a and 6b, the robot arm is rigid, and even if a slightly excessive external force is applied to the output arm 8, the robot arm is unlikely to break down.

[Effects of the Invention] As explained above, this invention pivots both sides of the output arm across the input arm, and
Separate gear mechanisms are installed on each input arm on both sides, and the drive force is transmitted from both sides to the support shaft, so the load is distributed and components such as gear shafts and bearings are made smaller. This has the effect of making the joints and arm system of the robot arm of industrial robot equipment thinner.

[Brief explanation of drawings]

Fig. 1a is an internal structural diagram of a robot arm showing an embodiment of the present invention, Fig. 1b is a view taken along the - line in Fig. 1a, and Fig. 2a is an internal structure of a conventional robot arm. The structural diagram, FIG. 2b, is a view taken along the - line in FIG. 2a. In the figure, 4a and 4b are support shafts (output shafts),
7a and 7b are robot arms (input side arms),
8 is a robot arm (output side arm), 10a,
10b is a gear mechanism. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. In an industrial robot device equipped with a robot arm that transmits driving force via a gear mechanism to an output side arm that is pivotally supported on an input side arm, the output side arm is held between the output side arm and the What is claimed is: 1. An industrial robot device characterized in that input side arms are provided on both sides to support the support shaft, and gear mechanisms for transmitting driving force to the support shaft are provided on each side of the input side arms. 2. The industrial robot apparatus according to claim 1, wherein the gear mechanism is a speed reduction mechanism.