JPS6334339B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotation drive device for rotating a rotated member.

Conventionally, for example, a rotational drive device shown in FIGS. 1 and 2 has been used. That is, a first gear 53 and a second gear 54 rotated by a rotary drive machine 52 via a reducer 51 are meshed with each other, and a worm 5, for example, is rotated integrally with the second gear 54.
5 and a worm wheel 56, and a rotating shaft 57 that rotates integrally with the worm wheel 56.
A rotated member 58 is disposed at the end of the rotatable member 58 . A support member is connected to the surface A of the rotated member 58, and the support member is rotated appropriately. By the way, in this type of rotary drive device, the rotated member 58
The distance between the surface A and the mounting surface B of the fixed frame 59;
Za is a distance; the maximum value of Za is often limited by various factors such as workability and relationship with other equipment. On the other hand, in order to reliably support the rotated member even when an eccentric load is applied to the rotated member, the minimum value of Zb, the distance between the bearings that rotationally support the rotated member, is limited by the mechanical structure. . Now, if the configuration is as shown in FIGS. 1 and 2, the value of Zb can be selected to be quite large even when the value of Za is relatively small. However, since the rotational axis of the rotary drive machine is approximately perpendicular to the rotational axis of the rotated member, the distance Ya from the rotation center of the rotated member to the end of the rotary drive machine is large, and this part is a so-called dead space. It was becoming.
When arranging a rotary drive device in this way, the dead space mentioned above must be taken into account, and even when it is desired to place other equipment near the rotary drive device, it may not be possible to arrange various equipment as desired. . In addition, the protruding parts of the rotary drive machine sometimes get in the way of work, and workability is not good. As shown in Figure 1, when a rotary drive and a reducer are installed at the end of the rotating shaft in the _Z2 direction with the bearing spacing set to Zb, the dimension of the rotary drive in the Z direction is It was impractical because of the large size.

An object of the present invention is to provide a rotary drive device that eliminates the above-mentioned conventional drawbacks.

The present invention will be explained in detail below with reference to the illustrated embodiments. In FIGS. 3 and 4, reference numeral 1 denotes a fixed frame whose one end is open, for example, in the _Z1 direction, and in the case shown, a lower half 101 and an upper half 102 are integrally fastened. . 2 is a rotary drive machine, for example, an electric motor, supported inside the fixed frame 1; 3 is an elliptical disk integrally supported on the output shaft of the rotary drive machine 2; 4 is a large number of anti-friction members. For example, the cylindrical body 5 is an elastic bushing integrally fastened to the rotated member 7, and external teeth 501 of an appropriate pitch are formed on the outer periphery of the elastic bushing 5. Reference numeral 6 denotes a gear body to which the fixed frame 1 is fastened, and internal teeth 601 are formed on the circular inner peripheral portion of the gear body. Although the inner teeth 601 and the outer teeth 501 have the same pitch, the inner teeth 601
The number of teeth is slightly increased. As shown in detail in FIG. 3, the internal teeth 601 and external teeth 501 located near the long axis of the elliptical disk 3 mesh with each other. 7 is a rotated member that covers the opening of the fixed frame 1 and covers the base side of the fixed frame 1; in the illustrated case, the rotated member 70 is divided into three
Members 1 to 703 are integrally fastened. Reference numerals 8 and 9 denote bearings disposed at a distance of Zd from the opening side of the fixed frame 1 and the base side of the fixed frame 1. For example, the bearings 8 and 9 are radial ball bearings. In this case, it is preferable to provide a thrust bearing 11 to counter the load in the _Z2 direction.
103 and 704 are respectively arranged at the overlapping parts of the fixed frame 1 and the rotated member 7,
A through hole 12 through which at least the rotary drive machine 2 can be inserted;
13 is a cover that covers the through hole 704 of the rotated member 7;
1 is a sealing member for protecting the bearing 9, and 14 is a rotation detector, such as a rotary encoder, which outputs a signal corresponding to the amount of rotation of the rotated member 7.

When the rotary drive machine 2 is driven in the above manner, the elliptical disc 3 rotates, thereby sequentially moving the meshing position between the external teeth 501 of the elastic bushing 5 and the internal teeth 601 of the gear body 6, and The elastic bush 5 rotates at a reduction ratio according to the difference in the number of teeth between the teeth 601 and the external teeth 501. As a result, the rotated member 7 that integrally supports the elastic bush 5 rotates.

Note that when installing the rotary drive machine 2, repairing the rotary drive machine after operation of the device, or adjusting the rotation detector 14, the work can be easily accomplished by removing the cover 12. Of course, if a cover is provided to cover the through hole 704, other members will not enter through the through hole 704, which is advantageous since it will not damage the bearing or other parts of the device or cause an accident.

In addition, if the reduction mechanism is configured by the elliptical disc 3, anti-friction member 4, elastic bush 5, and gear body 6, the reduction ratio can be increased to approximately 100:1 despite the small space.
The ratio can be selected from 1 to 300:1, and it is suitable if the above-mentioned rotated member is used as a revolving body of a revolving robot that requires particularly fine rotational accuracy. Note that, in spite of this, it is also possible to directly connect the rotated member and the rotary drive machine. It is also possible to connect the rotated member and the rotary drive machine via a rotation transmission mechanism, such as a tension belt and a pulley, a chain and a sprocket, or an appropriate reducer, but in this case, the rotary drive machine and the rotated drive machine can also be connected. The respective rotational axes of the members are maintained substantially parallel.

Furthermore, if a rotation detector is provided, appropriate control can be performed by inputting an output signal corresponding to the amount of rotation of the rotated member to the control device, but the rotation detector can be omitted. Further, the number of through holes provided in the fixed frame and the rotated member may be two or more. Here, the term "through hole" refers to the provision of a space that communicates the inner and outer parts of the fixed frame and the rotated member, respectively, in a substantially radial direction. Although there is a drawback that the rotation angle decreases, a through hole is still formed even when the upper half of the rotated member and the lower half supporting the bearing 9 are connected by a plurality of members. In this case, since the rotated member is rotated, it is preferable that a plurality of members connecting the upper half and the lower half of the rotated member are arranged approximately concentrically with respect to the rotation axis. Furthermore, it is also possible to employ a rotary drive machine operated by pressure fluid.

As described above, according to the present invention, the bearing that rotationally supports the rotated member is provided on the opening side of the fixed frame body in which one end that supports the rotary drive machine is open, and on the base side of the fixed frame body. Since the bearings are spaced apart from each other, the rotating member can be supported reliably, and the above-mentioned spacing between the bearings is based on the dimension of the base side of the fixed frame necessary to house the rotary drive machine. Because of this,
Although the spacing between the bearings can be selected to be large, the rotary drive device can have a compact structure with relatively small axial dimensions. Furthermore, since at least a through hole through which the rotary drive device can be inserted is provided in the overlapping portion of each of the fixed frame and the rotated member, regardless of whether the rotary drive device is being assembled or after the device has been assembled, The rotary drive device can be freely attached and removed through the through hole, and therefore maintenance of the rotary drive device is extremely easy.

Of course, since the rotary drive machine is arranged inside the fixed frame so that the respective rotational axes of the rotary drive machine and the rotated member are approximately parallel, the planar space of the device protrudes in one direction unlike the conventional one. This eliminates the need for so-called dead space, allowing other equipment to be placed anywhere near the rotary drive device, and making effective use of the factory site.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view showing a conventional device, FIG. 2 is a cross-sectional view taken along the line - in FIG. 1, FIG. 3 is a partially cutaway front view showing an embodiment of the present invention, and FIG. FIG. 4 is an upper half view of the cross section taken along the line - in FIG. 3; 1...Fixed frame body, 2...Rotary drive machine, 7...
Rotated member, 12...Cover, 103,704...
...through hole.

Claims (1)

[Claims] 1. In a rotary drive device in which the rotational axis of the rotary drive machine and the rotational axis of the rotated member are disposed substantially parallel and connected, the rotary drive machine is supported inside a fixed frame body with one end open, and A rotated member that extends over the base side of the fixed frame from the opening is rotatably supported by a bearing provided on the opening side and a bearing provided on the base side of the fixed frame, and the fixed frame and A rotary drive device, in which at least a through hole through which a rotary drive device can be inserted is provided in each overlapping portion of rotated members.