JPH0535288B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a planetary gear device used as a reduction gear.

Configuration of conventional example and its problems Figure 1 shows a conventional planetary gear device, and the input shaft 1
A sun gear 2 formed as shown in FIG. 1 meshes with a planetary gear 3, which in turn meshes with an internal gear 4. When the input shaft 1 rotates, the rotation is transmitted to the planetary gears 3, but since the internal gear 4 meshing with this is fixed, the first and second annular gears holding the plurality of planetary gears 3 The carrier plates 5, 6 rotate, and therefore the output shaft 7, which is integrally fixed to the first carrier plate 5, rotates. That is, the force transmitted from the input shaft 1 is transmitted to the bearing portions 9 and 10 of the first and second carrier plates via the shaft 8 rotatably inserted through the planetary gear 3, and is transmitted to the output shaft 7. However, in order for the force to act evenly on the bearings 9 and 10, the first and second carrier plates 5 and 6 must have a structure with high rigidity in the direction of rotation of the carrier plates. Therefore, as shown in FIG.
A cylindrical support part 11 having a substantially triangular cross section with a hole 11a in the center is provided protruding from the support part 11.
The structure was such that a step portion 13 of a support 12 of the first carrier plate 5 having a substantially triangular cross section was fitted into the support 1a. 14 is a small diameter portion provided at the tip of the stepped portion 13;
The rear end portion of the small diameter portion 14 inserted into the circular hole 15 of the support portion 11 is caulked to join the first and second carrier plates 5, 6 together. With this structure, if the gap between the planetary gear 3 and the support column 12 is small, the diameter of the stepped portion 13 cannot be made large, resulting in weak strength. 12 becomes taller,
There was a problem that the bending moment acting on the base 16 of the stepped portion 13 became large, resulting in weak strength.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned conventional problems, and aims to provide a planetary gear device that is strong in strength.

Structure of the Invention In order to achieve the above object, the present invention provides a sun gear formed on an input shaft, a plurality of planetary gears that mesh with the sun gear, a front gear that meshes with these planetary gears, and a front gear that meshes with the planetary gears. first and second carrier plates that hold both upper and lower ends of a shaft that is freely inserted; the first carrier plate is provided with a support having a small diameter portion at its tip; and the upper surface of the second carrier plate a recessed portion and a hole located within the recessed portion, the small diameter portion of the support post is inserted into the hole within the recessed portion, and the side portion of the support near the small diameter portion and on the side in the rotation direction of the carrier plate, The structure is such that it engages with the side wall of the recess, thereby increasing the strength of the device.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 3 and 4. FIG. 3 shows a planetary gear device of the present invention, in which 21 is an input shaft, 22 is a sun gear formed integrally with the input shaft 21, 23 is a sun gear 22 and an internal gear, 24 is a planetary gear meshing with The shaft is rotatably inserted into the planetary gear, and its upper and lower ends are fixed to the first and second carrier plates 26 and 27, respectively.The first and second carrier plates 26 and 27 are connected to the first carrier plate. It is integrated by the struts 28 of the plate 26. The column 28 has a reduced diameter portion 29 at its tip, while the second carrier plate 27 has a recess 31 formed in its upper surface and a circular hole 30 located within the recess 31. The small diameter portion 29 at the tip of the support column 28 is inserted into the circular hole 30 of the second carrier plate 27 and caulked.
A side portion 28a of the support column 28 near the small diameter portion 29 and on the carrier plate rotation direction side engages with the side wall 31a of the recess 31.

Next, the effect will be explained. The rotation of the input shaft 21 is transmitted to the sun gear 22 and the planetary gears 23.
Since the internal gear 24 is fixed, the carrier plates 26, 27 rotate, and therefore the output shaft 32, which is fixed to the first carrier plate 26, rotates.
rotates. The force applied from the input shaft 21 is transmitted to the bearing portions 33 and 34 of the first and second carrier plates via the shaft 25, and at this time, the force applied from the input shaft 21 is transmitted to the bearing portions 33 and 34 of the first and second carrier plates. The force is transmitted to the stepped portion 29 of the strut 28 of the plate 26, but since the side portion 28a of the strut 28 on the carrier plate rotation direction side is engaged with the side wall 31a of the recess 31, the side wall 31a also has the side portion of the strut 31. Force is transmitted through 28a, and the force is not concentratedly applied to the small diameter portion 29 of the support column 28, and the rigidity of the first and second carrier plates 26 and 27 can be increased. Furthermore, since the base of the stepped portion 29, which is the weakest portion in terms of strength, is located at the lowest part of the support column 28, no large bending moment is generated in the stepped portion 29, resulting in a strong structure.

Effects of the Invention As explained above, according to the present invention, the strength of the connection between the first carrier plate and the second carrier plate by the support is increased, and a structurally strong planetary gear device can be obtained.

[Brief explanation of the drawing]

1 and 2 show a conventional planetary gear device, FIG. 1 is a sectional view, FIG. 2 is a plan view of a second carrier plate, and FIGS. 3 and 4 are planetary gears according to the present invention. One embodiment of the device is shown, with FIG. 3 being a sectional view and FIG. 4 being a plan view of the second carrier plate. 21...Input shaft, 22...Sun gear, 23...
Planetary gear, 24...Internal gear, 25...Shaft, 26
...First carrier plate, 27... Second carrier plate, 28... Support column, 28a... Side part of support column, 29... Small diameter portion, 30... Circular hole, 31
...Concavity.

Claims (1)

[Claims] 1. Holds a sun gear formed on an input shaft, a plurality of planetary gears that mesh with the sun gear, an internal gear that meshes with these planetary gears, and both upper and lower ends of a shaft that is rotatably inserted through the planetary gears. first and second carrier plates, the first carrier plate is provided with a support having a small diameter portion at its tip, and the second carrier plate has a recess on the upper surface thereof and a hole located in the recess. A planetary gear device, wherein a small diameter portion of the support is inserted into a hole in the recess, and a side portion of the support near the small diameter portion and on a rotational direction side of the carrier plate is engaged with a side wall of the recess.