JP2741711B2 - Planetary gear reducer - Google Patents

Description

The present invention relates to an improvement of a planetary gear reducer.

(Prior Art) A conventional planetary gear reducer will be described with reference to FIGS. 2 and 3. FIG. FIG. 2 is a longitudinal sectional view of a known planetary gear reducer for a control device, and FIG. 3 is a sectional view taken along line III-III of FIG.

The hollow input shaft 1 is provided with eccentric bodies 3a, 3b, 3c on the outer periphery thereof with a predetermined phase difference (120 ° in this example).
External gears 5a, 5b, 5c are arranged on the outer periphery of the eccentric bodies 3a, 3b, 3c via rolling bearings. The external gears 5a, 5b, 5c are provided with a plurality of inner roller holes 6 on the circumference, and the inner pins 7 are loosely fitted into the holes 6 via the inner rollers 8. The external gear 5
External teeth 9 such as a trochoid tooth shape and an arc tooth shape are provided on the outer periphery of a, 5b, and 5c, and the external teeth are in internal mesh with an external pin 11 provided on the internal gear 10. In this case, the outer pin 11 may be provided with an outer roller (not shown).

The inner pin 7 is fitted into the output shaft flange 2 (output shaft). In this known example, one rotation of the input shaft 1 is one rotation of the eccentric bodies 3a, 3b, 3c, but the rotation of the external gears 5a, 5b, 5c is restricted by the inner pin 7 through the inner roller hole 6. The external gear 5a, 5b, 5c
When the difference in the number of teeth (number of teeth) is one, one rotation of the input shaft 1 causes the external teeth 9 of the external gears 5a, 5b, 5c and the external pin 11 constituting the internal teeth of the internal gear 10 to move outward. The gears 5a, 5b, and 5c are displaced by meshing with one tooth. Therefore, one rotation of the input shaft 1 is reduced to 1 / the number of teeth of the external gears 5a, 5b, 5c, and the rotation is transmitted to the output shaft flange 2 via the inner pin 7.

On the other hand, when the output shaft flange 2 is fixed in FIG. 2, the rotation of the input shaft 1 is similarly reduced and taken out as the rotation of the internal gear 10. In this case, if the difference between the number of teeth of the external gears 5a, 5b, 5c and the number (number of teeth) of the external pins 11 is one, the rotation of the input shaft 1 causes the external teeth 9 of the external gears 5a, 5b, 5c to rotate. And the external pin 11, which is the internal tooth of the internal gear 10, meshes and shifts (shifts) by one tooth of the internal gear 10. Therefore, one rotation of the input shaft 1 is reduced to 1 / number of teeth of the internal gear 10 (that is, 1 / number of teeth of the external gears 5a, 5b, 5c + 1) and appears as rotation of the internal gear 10. Generally, the output shaft flange 2 is attached to a rotating shaft of a mating machine to reduce the rotation of the input shaft and transmit it as a large torque.

The casing 15 is integrated with the internal gear 10 and is attached to a casing of a mating machine by inserting a bolt into a mounting bolt hole 16 and tightening the bolt. The output shaft flange 2 is rotatably held on the inner peripheral surface of the casing 15 by a cross roller bearing 12. The reason why the cross roller bearing is used here is to make the structure in the axial direction compact,
To increase rigidity, the preload is
This is performed by the holding plate 13 on the outer ring side of the holding member 12 and the holding plate mounting bolts 14.

Now, in the above-described structure, when the side surface 15a of the casing 15 is used as the installation surface, the holding plate 13 for applying a preload to the cross roller bearing 12 needs to be located inside the side surface 15a. Further, the holding plate mounting bolts 14 need to be located radially outside the outer ring of the cross roller bearing 12, and the bolt mounting holes 16 in the casing of the mating machine have to be located further radially outside the holding plate 13. For this reason, the outer diameter and width of the casing 15 had to be very large. Moreover, since the cross roller bearing 12 is provided so as to be displaced with respect to the width direction of the planetary gear reducer, the width direction is further widened. Further, since the inner pin 7 is of a cantilever type, the rigidity of the inner pin 7 is reduced, and a high load cannot be applied.

(Problems to be Solved by the Invention) In the planetary gear reducer, the structure is made more compact to reduce the weight, and the inner pin has a double-sided structure to improve the rigidity of the inner pin and to easily adjust the preload of the bearing. It is an object to provide a planetary gear reducer.

(Means for Solving the Problems According to the Invention) The internal gear has an arc tooth shape, the external gear has a trochoid tooth shape, and the like, and the planetary gear which takes out the rotation of the external gear by a constant speed gear mechanism comprising a combination of an internal pin and an internal pin hole. In the speed reducer, an outer ring of a tapered roller bearing is provided integrally or separably on a casing constituting an internal gear, and an output shaft flange holding an internal pin is disposed on both sides of the external gear train so as to sandwich the output gear. The outer peripheral surface of the shaft flange is used as the inner ring of the tapered roller bearing, and a screw portion is provided at the tip of the inner pin, and both output shaft flanges are made to be able to freely contact and separate by a tightening member screwed into the screw portion. The gap between the bearings can be adjusted. The output shaft flange that holds the inner pins should have bolt holes for mounting to the mating machine between the inner pins of the inner pin row. More was freely the mounting direction.

(Example) A description will be given based on FIG. The present invention is an improvement of the bearing between the output shaft flange and the internal gear and the output shaft flange itself. Therefore, similarly to the known planetary gear reducer shown in FIG. 2, the input shaft 1 is provided with the eccentric bodies 3a, 3b, 3c. The external gears 5a, 5b, 5c are fitted on the outside of the eccentric bodies 3a, 3b, 3c, and the external gears 5a, 5b, 5c are engaged with the external pins 11 constituting the internal gear on the outside. The points are the same.

Now, in FIG. 1, reference numerals 22 and 26 denote output shaft flanges and external gears.
It is composed of a pair of left and right members sandwiching 5a, 5b, 5c. The output shaft flanges 22 and 26 are provided with inward tapered surfaces 22a and 26a on the outer peripheral surface, respectively, and the inner pin 21 and the bolt (tightening member) 27 penetrating through the inner roller holes of the external gears 5a, 5b and 5c. It is tightened so that the distance between them can be adjusted.

On both sides of the internal gear 24 meshing with the external gears 5a, 5b, 5c, a bearing outer ring 25 is fastened with bolts inserted into mounting bolt holes 29. The bearing outer ring 25 has an outward tapered surface on its inner peripheral surface.
25a, the tapered surface 25a and the output shaft flanges 22, 26
Between the tapered surfaces 22a and 26a provided on the outer peripheral surface of
3 are arranged.

The inner pin 21 has a flange at one end and a screw hole into which a bolt 27 is screwed at the other end, and both ends thereof are supported by the output shaft flanges 22 and 26 as described above. These output shaft flanges 22 and 26 are provided with bolt holes 28,
A mounting bolt is screwed into 8, and attached to the other machine.

Left and right output shaft flanges 22 and 26 have inner pin 21 and bolt 27
The output shaft flanges 22 and 26 are brought into contact with and separated from each other by using the inner pin 21 as a guide by adjusting the tightening force of the bolt 27 to adjust the distance. Thus, an appropriate preload can be applied to the tapered roller 23.

Although the internal gear 24 and the bearing outer ring 25 are formed as separate members in the embodiment, they may be formed integrally.

Further, by forming a male screw at the other end of the inner pin 21 and screwing a nut into the screw portion, the output shaft flanges 22 and 2 are formed.
6 may be adjusted to each other.

With the above configuration, the side surface 25b of the bearing outer ring 25 is used as an installation surface on a casing (not shown) of the mating machine, and a bolt is inserted into an installation bolt hole 29 provided in the bearing outer ring 25 and the internal gear 24. And install it on the other machine.

In addition, a rotating part (for example, a robot arm or the like) of a counterpart machine is attached by bolt holes 28 provided in the left and right output shaft flanges 22 or 26. As a result, the rotation input from the input shaft 1 is reduced and output to the output shaft flanges 22 and 26 supported by the tapered rollers 23.

In addition, since the output shaft flanges 22 and 26 form a pair on the left and right, even if the mounting relationship between the casing and the rotating part of the mating machine is reversed, it can be easily mounted.

(Effects of the Invention) 1) Since the output shaft flanges 22 and 26 and the bearing outer ring 25 held by the internal gear are held by the tapered rollers 23, the cross roller bearing of the conventional structure and the parts necessary for mounting the same (the holding plate and the holding plate) No holding plate mounting bolt) is required, and thus the structure is reduced in size and weight.

2) The output shaft flanges 22 and 26 have a double-supported structure by fitting with the inner pin 21.
Since the rigidity can be further improved as compared with, a high load can be applied.

3) By providing the bolt holes 28 in the output shaft flanges 22 and 26, the mounting direction to the mating machine can be freely changed left and right.

4) Since the output shaft flanges 22 and 26 can freely contact and separate the inner pin 21 from the guide by adjusting the tightening of the bolt 27, the appropriate preload to the taper roller 23 can be easily adjusted at the final stage of the assembly of the speed reducer.

[Brief description of the drawings]

 FIG. 1 is a longitudinal sectional view of a planetary gear reducer according to the present invention. FIG. 2 is a longitudinal sectional view of a known planetary gear reducer. FIG. 3 is a sectional view taken along the line III-III in FIG. In the figure: 1 ... input shaft, 2 ... output shaft flange 3a, 3b, 3c ... eccentric body 5a, 5b, 5c ... external gear, 6 ... inner roller hole 7 ... inner pin, 8 ... Internal roller 9 External teeth 10 Internal gear 11 External pin 12 Cross roller bearing 13 Holding plate 14, Holding plate mounting bolt 15 Casing, 16 Mounting bolt hole 21 …… Inner pin, 22 …… Output shaft flange 22a …… Taper surface, 23 …… Taper roller 24 …… Internal gear, 25 …… Bearing outer ring 25a …… Taper surface, 26 …… Output shaft flange 26a …… Taper Surface 27 bolts 28 bolt holes 29 bolt holes

Claims (2)

(57) [Claims] A planetary gear reducer in which the internal gear has an arc tooth shape, the external gear has a trochoidal tooth shape or the like, and the rotation of the external gear is taken out by a constant speed gear mechanism comprising a combination of an internal pin and an internal pin hole. An outer ring of a tapered roller bearing is provided integrally or separably on a casing constituting an internal gear, and an output shaft flange holding an internal pin is arranged on both sides with the external gear train interposed therebetween. While the outer peripheral surface is used as the inner ring of the tapered roller bearing,
A planet having a threaded portion at the tip of the inner pin, wherein a gap between the tapered roller bearings can be adjusted by making both output shaft flanges freely accessible and disengageable by a fastening member screwed into the threaded portion. Gear reducer. 2. An output shaft flange for holding an inner pin, wherein a mounting bolt hole for mounting to an opposing machine is provided between the inner pins of the inner pin row so that the mounting direction can be freely changed. The planetary gear reducer according to 1).