JPH06123337A - Plural input and plural output reduction gear - Google Patents

Abstract

PURPOSE:To provide a single unified reduction gear with the simple structure, in which plural reduced rotation output can be obtained from plural rotation input. CONSTITUTION:A plural input and plural output reduction gear is provided with plural input shafts 10, 12 for leading the rotation input, and plural reduction gear mechanisms 14, 16a-16c:28, 30a-30c for respectively reducing plural rotation input at a predetermined reduction ratio, and differential gear elements 18, 18a, 18b for differentially connecting the same plural number of reduction gear mechanisms to each other, and output shafts 32, 34 for outputting plural reduced rotation output, and a housing means for housing them.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speed reducer having a compact structure for decelerating a plurality of rotation inputs to obtain a plurality of individual rotation outputs, and reducing the number of structural elements. , Which is applicable to a deceleration output device using a drive source as a driving source, and has industrial utility as a joint part of an industrial robot, especially a wrist joint part, etc.
The present invention relates to a multiple output speed reducer.

[0002]

2. Description of the Related Art There are various types of reduction gears that use various motors as rotation drive sources and reduce rotation inputs from the motors at a desired reduction ratio to obtain rotation outputs. For example, a speed reducer using a multi-stage gear, a belt / pulley type speed reducer, a chain / sprocket type speed reducer, etc. are typical typical speed reducers of the past, and recently, servo devices have been used as driving means in joints of industrial robots. It is decelerated from the rotation input of the motor to the rotation output according to the operating speed of each joint and the required torque, and the output is obtained on the same axis, and the joint is driven by the reduced rotation output. Speed reducers are also commonly used.

[0003]

However, the conventional speed reducer obtains one decelerated rotation output from one rotation input. Therefore, a conventional reduction gear of this type is used in, for example, an industrial robot. When it is used as a driving means in a joint, when the joint has a plurality of operating axes, it is necessary to dispose a servo motor and a speed reducer in pairs for each axis.

Where it is necessary to design the outer shape to be small from the viewpoint of robot operation, such as the wrist joint of an industrial robot, it is impossible to provide all drive sources for each axis in the wrist joint. Therefore, after all, install a rotary drive source such as a servomotor not in the vicinity of each output shaft of the wrist, but in a place where there are few restrictions on the external dimensions such as the rear end region of the arm equipped with the wrist at the tip. However, it has been necessary to adopt a configuration in which the rotational input is transmitted from the rotational drive source to a speed reducer incorporated in the area of the wrist through a drive shaft extending in the arm. As a result, with respect to the wrist joint portion having a large number of operating axes such as two or three axes, the drive shaft and the speed reducer have a hollow coaxial structure so that another shaft system is penetrated and arranged inside one shaft system. There is a problem in that the structure such as the above must be integrated and a compact drive mechanism must be realized, and the structure becomes extremely complicated and difficult to design.

Therefore, an object of the present invention is to completely change the structure of the speed reducer so that one united speed reducer can obtain the same plurality of rotation outputs from a plurality of rotation inputs and simply the conventional plurality of speed reducers. Multiple inputs and multiple outputs that achieved a compact overall structure including a drive source for rotary input by introducing a reduction element shared between multiple input and output systems, rather than combining and consolidating To provide a speed reducer.

[0006]

SUMMARY OF THE INVENTION According to the present invention, a plurality of rotation inputs that are coaxially input are decelerated by a plurality of reduction gear mechanisms to obtain a plurality of rotation outputs, and a plurality of reduction gear mechanisms are provided. By incorporating gear elements shared by each other, the number of actuating structural elements in the device is reduced, and a plurality of reduction gear mechanisms described above are collectively incorporated in one housing to form a unit. It is what

That is, according to the present invention, a plurality of input shaft means for introducing a plurality of rotation inputs and a plurality of decelerations for decelerating each of the plurality of rotation inputs introduced from the plurality of input shaft means at a predetermined reduction ratio. Gear means, a differential gear element for differentially connecting the plurality of reduction gear means to each other, and a plurality of deceleration rotation outputs same as the rotation input through the plurality of reduction gear means and the differential gear element. Multiple input / multiple output configured to include an output shaft unit for taking out the input shaft unit, a case unit integrally storing the input shaft unit, the plurality of reduction gear units, the differential gear element, and the output shaft unit. A speed reducer is provided.

[0008]

According to the multiple input / multiple output speed reducer having the above-described structure, a compact multiple input / multiple output speed reducer can be obtained because the plurality of speed reducing gear means share one differential gear element with each other. Therefore, it can be applied as a joint shaft of an industrial robot and used as a compact speed reducer. Hereinafter, the present invention, based on the embodiments shown in the accompanying drawings,
Furthermore, it demonstrates in detail.

[0009]

1 is a perspective view showing the structure of a multiple input, multiple output speed reducer according to an embodiment of the present invention, FIG. 2 is a perspective three-dimensional view showing the assembled state of the same, and FIG. FIG. 4 is a schematic mechanism diagram showing a state in which the multiple input / multiple output reducer according to the present invention is incorporated in a wrist joint of an industrial robot, and FIG. 4 is a schematic cross-sectional view showing a modified example of the reducer shown in FIG.

Referring to FIGS. 1 and 2, the multi-input, multi-output speed reducer according to this embodiment is an embodiment configured as a speed reducer for decelerating two rotary inputs to obtain two rotary outputs. , And has a first rotation input shaft 10 and a second rotation input shaft 12. The former first rotary input shaft 10 extends axially through the central portion of the latter second rotary input shaft 12, and has a cylindrical pinion 14 having spur teeth or helical teeth at its tip.
As a sun gear on the input side. On the other hand, the second rotary input shaft 12 also has a small bevel gear 28 as an input-side sun gear at the tip.

The cylindrical pinion 14 of the first rotary input shaft 10 has a driven gear 16 having three identical gear elements arranged at equal intervals on a circumference having a number of teeth larger than the number of teeth thereof.
a, 16b, 16c, these three driven gears 16a, 16b, 16c are all internal teeth 1 of a ring gear 18 formed as an annular internal tooth sun gear.
8a is arranged in a planetary gear system at three points.

However, the above three driven gears 16
a, 16b, and 16c are attached to external elements, that is, three shafts 22 provided on a fixed disk member 20 that is connected to an equipment frame or the like to form a fixed element so as to be rotatable through bearings. However, the ring gear 18 is provided in a configuration in which planetary movement is blocked. Therefore, the rotation input of the cylindrical pinion 14 is generated by the three driven gears 16a to 16a.
6c causes each driven gear to rotate, and at this time, the three driven gears 16a to 16c are rotated in accordance with a reduction ratio corresponding to the tooth number ratio with the tooth number of the cylindrical pinion 14, and further,
Reduced rotation according to the reduction ratio between the number of teeth of each gear of the driven gears 16a to 16c and the number of teeth of the ring gear 18 that is the sun gear is transmitted to the ring gear 18 to generate the reduced rotation of the ring gear 18. . That is, the cylindrical pinion 14, the driven gears 16 a to 16 c, and the ring gear 18 form a first reduction gear system. Here, the ring gear 18 has another inner tooth 18b which is concentrically formed on the inner back side and is cut into a tooth shape together with the inner tooth 18a.

The small bevel gear 28 attached to the tip of the second rotary input shaft 12 forms the sun gear, and also the beveled internal teeth 18b of the ring gear 18 which also forms the outer sun gear. Bevel gears 30a, 30b, 3 which are three planetary gears having the same gear specifications that mesh with each other in an oblique state.
It meshes with 0c. At this time, three planet bevel gears 30a, 3a,
The number of teeth of each of 0b and 30c is formed to be large, and therefore, each of these three bevel gears 30a to 30c rotates at a rotational speed that is reduced from the rotational input of the small bevel gear 28 according to the tooth ratio.

The three planetary bevel gears 30a to 30c, each of which rotates as described above, are provided so as to mesh with the internal teeth 18b of the ring gear 18, which is the sun gear, in an oblique manner as described above. However, from such an oblique arrangement, rotation is performed at equal intervals on the single coupling member 32 with one generatrix of a cone having an apex on the center line of the second rotation input shaft 12 as each rotation center. These three bevel gears 30a to 30c, which are rotatably attached via bearings and are integrated by the same coupling member 32, by the meshing with the internal teeth 18b of the ring gear 18 forming the sun gear, The planetary motion or revolution is integrally provided relative to the ring gear 18 in a freely rotatable manner. That is, the small bevel gear 28, the three planetary bevel gears 30a to 30c, and the sun ring gear 18 having the internal teeth 18b form a second reduction gear system. And the sun ring gear 1
8 has a special configuration that functions as a common reduction gear element in the above-described first and second reduction gear systems. Therefore, this sun ring gear 18 is provided as a common functional element for the two reduction gear systems. By so doing, a compact double-input / double-output speed reducer is formed, and conversely, when the sun ring gear 18 is removed, both the first and second speed reducing gear means decelerate their respective rotary inputs. It is configured to lose its ability.

Now, the above-mentioned first and second rotation inputs are
The orbital rotation of the coupling member 32 that is decelerated and couples the three bevel gears 30a to 30c in the second reduction gear system is taken out as a first decelerated rotation output, and any one of these three bevel gears 30a to 30c is extracted. It can be understood that the rotation rotation of the bevel gear 30a in the illustrated example can be taken out as the second deceleration rotation output.

Here, the first and second rotation inputs are Ip-
1, Ip-2, 1st, 2nd deceleration rotation output is Op-1,
Op-2, the number of teeth of the pinion 14 is Z1s, the number of teeth of the small bevel gear 28 is Z2s, the number of teeth of each of the driven gears 16a to 16c is Z1p, and the number of inner teeth 18a of the ring gear 18 is Z.
1r, the number of teeth of the internal teeth 18b of the ring gear 18 is Z2r,
Further, when the number of teeth of each of the three bevel gears 30a to 30c is Z2p, the relationships of the following equations (1) and (2) can be obtained from the principle of the well-known planetary gear mechanism.

[0017]

In FIGS. 1 and 2, the output shaft 34 projects only from the bevel gear 30a that obtains the first decelerated rotation output Op-2, and the other bevel gear 30.
The output shafts b and 30c are rotatably fitted to the coupling member 32 via a rotary bearing, and have a structure that is not in a protruding state. Then, the first and second rotation input shafts 10,
Reference numeral 12 indicates an individual unit to be applied if each is connected to a rotary drive source such as an individual servo motor and the number of teeth of each reduction gear in the above formulas (1) and (2) is appropriately selected and set. It is possible to obtain a desired decelerated rotation output in the device.

Although not shown in FIGS. 1 and 2, the first and second reduction gear systems described above are housed in a container-shaped device housing to form a single reduction device. It goes without saying that it will be configured.

FIG. 3 shows an application example in which such a multiple input / multiple output speed reducer is incorporated in a drive mechanism for a wrist joint of an industrial robot. In FIG. 3, the wrist joint portion is provided with the hollow chamber 42 of the robot arm 40 and the drive shaft 4
The two rotation inputs transmitted by the robot arms 4 and 46 are converted in direction by an appropriate bevel gear mechanism 48, and then the robot arm 4 concerned.
It is mounted in a wrist joint housing composed of a first wrist housing 50 fixed to the tip of 0 and a second wrist housing 52 pivotally attached to the first wrist housing 50 via a rotary bearing 54. Multiple input, multiple output speed reducer 60
Is configured to obtain two decelerated rotation outputs Op-1 and Op-2.

Here, the first deceleration rotation output Op-1 is
The second deceleration rotation output Op-2 is extracted as the rotation output of the second wrist housing 52, and is extracted as the rotation output of the wrist flange 56 attached to the output element 62 formed by the rotating bevel gear of the reduction gear 60. ing. Reference numeral 58 is a rotary bearing of the output element 62 of the speed reducer 60. In this embodiment, two rotation inputs are introduced from the member side corresponding to the fixed member 20 of the speed reducer shown in FIGS. 1 and 2, and two rotation outputs are obtained from the opposite side to the introduction side. There is.

As is apparent from this configuration, a single speed reducer 60 is incorporated in the wrist joint housing, and this is used for two rotation inputs of the servo motor input from the robot arm system via the drive shafts 44 and 46. When coupled at the input end side, it is possible to obtain two decelerated rotation outputs,
As in the conventional wrist joint, there is an advantage that the wrist joint can be easily configured by eliminating the complexity and complexity of disposing the two reduction gears in a narrow space.

FIG. 4 is a cross-sectional view showing the structure of another embodiment according to the present invention. In this embodiment, unlike the above-mentioned embodiment, two rotary inputs are arranged so that two rotary inputs are arranged opposite to each other in a coaxial arrangement. The input is made from the shafts 110 and 122. Note that the other reduction gear elements have the same configuration as that of the first embodiment described above, and the reference numbers of the respective gear elements of the embodiments of FIGS. 1 and 2 are shown so that the correspondence can be easily understood. It is designated by the reference number with 100 added. Thus, FIG.
Also in the embodiment shown in (1), the single reduction gear transmission is configured to obtain two reduced rotation outputs from two rotation inputs.

[0024]

As is apparent from the above description, according to the present invention, a plurality of sets of reduction gear systems are housed inside a single housing body, and further reduction gears shared by these plurality of reduction systems are provided. By using the elements, it is possible to reduce the number of structural parts and to obtain a compact new dual-input and dual-output reduction gear transmission. Therefore, it is possible to obtain a deceleration device that can be easily incorporated into various devices such as a joint part of an industrial robot and that can obtain a plurality of deceleration outputs from a plurality of inputs that occupy a small space.

[Brief description of drawings]

FIG. 1A is an exploded perspective view showing the configuration of a multiple input, multiple output reduction gear transmission according to an embodiment of the present invention. (B) is
It is a partial sectional view.

FIG. 2 is a perspective three-dimensional view showing an assembled state of the device.

FIG. 3 is a schematic mechanism diagram showing a state in which a multiple input / multiple output reduction gear device according to the present invention is incorporated in a wrist joint of an industrial robot.

FIG. 4 is a schematic cross-sectional view showing a modified example of the speed reducer of FIG.

[Explanation of symbols]

 10 ... 1st rotation input shaft 12 ... 2nd rotation input shaft 14 ... Cylindrical pinion 16a-16c ... Driven gear 18 ... Ring gear 18a ... Internal tooth 18b ... Other internal tooth 20 ... Fixed disk member 22 ... Shaft 28 ... Small bevel gears 30a, 30b, 30c ... Bevel gear 32 ... Coupling member 34 ... Output shaft 50 ... First wrist housing 52 ... Second wrist housing

Claims (1)

[Claims] 1. An input shaft means for introducing a plurality of rotation inputs; a plurality of reduction gear means for reducing each of the plurality of rotation inputs introduced from the plurality of input shaft means at a predetermined reduction ratio; Differential gear elements for differentially connecting the reduction gear means to each other, and output shaft means for extracting the rotation inputs and the plurality of reduced rotation outputs through the plurality of reduction gear means and the differential gear elements. A plurality of input shaft means, the plurality of reduction gear means, the differential gear element, and a case means that integrally houses the output shaft means.
Multiple output speed reducer.