JPH07280042A - Reduction gear of small planetary gear - Google Patents

Abstract

PURPOSE:To facilitate the precise assembly of a planetary gear mechanism relative to a case, miniaturize the device, and improve the transmission performance and the service life by stably holding a carrier. CONSTITUTION:Planetary gear mechanisms 11, 21 of one or more stages are internally provided between an input shaft 4 and an output shaft 6 on the center axis in a case 1 consisting of an input side case 2 and an output side case 3 which are connected to each other between the respective faucet joint parts 2a, 3a where the revolving motion of a plurality of planetary gears 16, 26 which are externally engaged with sun gears 13, 23 to be rotated on the center axis and internally engaged with internal gears 14, 24 fixed to the case 1 is transmitted to carriers 18, 28 through the respective planetary pins 17, 27. A bearing 31 is arranged on the outer circumference of the prescribed carrier 18, and an outer wheel of the bearing 31 is fitted to and supported by the inner circumference of the respective faucet joint parts 2a, 3a of the input side case 2 and the output side case 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small planetary gear reducer equipped with a planetary gear mechanism having one or more stages.

[0002]

2. Description of the Related Art As a planetary gear speed reducer,
As disclosed in Japanese Patent No. 81 and Japanese Utility Model Publication No. 4-48345, the case externally meshes with a sun gear that is rotationally driven on the central axis and also internally meshes with an internal gear fixed to the case. It is well known that one or more stages of planetary gear mechanisms, in which the revolution movements of a plurality of planetary gears are transmitted to the carrier via each planet pin, are internally provided between the input shaft and the output shaft on the central axis. Is.

In the above structure, the case is composed of an input side case and an output side case connected between the spigot parts to enable disassembly and assembly of the internal planetary gear mechanism, and the output shaft is stabilized. Is supported by the case through two rows of front and rear bearings, and the intermediate carrier is supported on one side by the sun gear and the internal gear of the stage via the planetary gears of the stage, and on the other side by the next side. It is integrated with the sun gear of the next stage and supported by the planetary gear of the next stage.

[0004]

However, in the conventional planetary gear reducer, the processing of the bearing portion of the planetary gear mechanism and the processing of the spigot portion of the case are performed individually, so the tolerance accuracy becomes unsatisfactory. The precise assembly of the planetary gear mechanism becomes difficult and the number of processing steps increases, the two rows of front and rear bearings provided for the stable support of the output shaft hinder the miniaturization of the device, and the support of the intermediate carrier. Due to the structure, the carrier shaft is liable to be shaken due to a gap between respective parts in the planetary gear mechanism or a slight machining error, which causes a vibration noise of the reducer and an early damage.

The object of the present invention is to reduce the size of the planetary gear mechanism by facilitating the precise assembly of the planetary gear mechanism to the case, enabling the miniaturization of the device, and further holding the carrier stably to improve the transmission performance and life. To provide a machine.

[0006]

According to a first aspect of the present invention, there is provided a small planetary gear reducer, which comprises a case including an input-side case and an output-side case connected between spigot parts, on a central axis line. A plurality of planetary gears that are externally meshed with the sun gear that is rotationally driven and that are internally meshed with the internal gear that is fixed to the case are transmitted to the carrier through the planet pins. In a planetary gear reducer in which a planetary gear mechanism is internally mounted between an input shaft and an output shaft on a central axis, a bearing is arranged around a specific carrier and an outer ring of the bearing has an input side case and an output side case. It is characterized in that it is fitted and supported on the inner circumference of each spigot part.

In the small planetary gear reducer of the second aspect of the present invention, in the above construction, the internal gear is inserted into the case at a predetermined position along the inner periphery of the spigot portion.

A small planetary gear reducer according to a third aspect of the present invention has the above structure, wherein at least the outer periphery of the carrier at the final stage is
It is supported on the inner circumference of the case via bearings on both sides of the planetary gear.

In the small planetary gear reducer according to a fourth aspect of the present invention, in the above structure, at least the output side of the carriers on both sides of the planetary gear are at least on the output side, and the sun gear of the stage is integrated with the carrier of the preceding stage on the inner circumference of the carrier. The shaft is supported by bearings.

[0010]

In the small planetary gear reducer according to claim 1,
The rotation of the input shaft is decelerated via the sun gear, the planetary gears and the carrier in each planetary gear mechanism, and finally transmitted to the output shaft.

In the above construction, since the outer ring of the bearing arranged on the outer periphery of the specific carrier is fitted and supported on the inner periphery of the spigot portion of the input side case and the output side case, the carrier which is the inner ring fitting portion of the bearing is The processing of the outer periphery and the processing of the spigot portion of the case are necessarily performed in association with each other, and a high tolerance precision can be obtained in the fitting structure between the outer ring of the bearing and the inner circumference of the spigot portion of the case. The coaxiality can be easily obtained for each element of each planetary gear mechanism.

In the small planetary gear reducer of claim 2,
In each spigot portion of the case, an internal gear having an outer diameter equal to that of the outer ring of the bearing is inserted before the carrier with a bearing is inserted into the case.

In the small planetary gear reducer of claim 3,
The carrier is stably supported by the case via the front and rear two rows of bearings, and when it is the final stage carrier, the output shaft integrated with the carrier is further supported by the front and rear two rows of bearings as in the conventional case. Eliminates the need to be supported by.

Further, in a small planetary gear reducer according to a fourth aspect of the invention, the sun gear shaft of the stage, and hence the extension of the carrier of the preceding stage, has a bearing on the inner periphery of the carrier, at least on the output side on both sides of the planetary gear. The carrier of the stage and the carrier of the preceding stage are mutually supported and stabilized. By combining such a carrier support structure with the carrier support structure described in claim 3, a more stable carrier support structure and excellent assembling property can be obtained.

[0015]

EXAMPLES The present invention will be specifically described below based on examples.

[Embodiment 1] FIG. 1 is a sectional view of a small planetary gear reducer according to Embodiment 1 of the present invention. In the figure,
Two-stage planetary gear mechanisms 11 and 21 are installed in the case 1,
The case 1 is composed of an input side case 2 and an output side case 3, and spigot portions 2a, 3a are provided at respective inner ends.

In the first stage planetary gear mechanism 11, the input shaft 4 is supported by the case 1 on the central axis line via bearings 5, and the sun gear 13 is mounted on the sun gear shaft 12 connected to the input shaft 4. An internal gear 14 is provided on the inner circumference of the case 1, is inserted along the inner circumference of the spigot portion 2a of the input side case 2, and is fixed by a pin or a key.
Are evenly arranged so as to externally mesh with the sun gear 13 and internally mesh with the internal gear 14, and the planet pins 17 of each planetary gear 16 are supported by the carrier 18, and the output side flange 18b of the carrier 18 has a second The sun gear shaft 22 of the stepped planetary gear mechanism 21 is connected on the central axis.

Next, in the second stage planetary gear mechanism 21, the sun gear 23 is provided on the sun gear shaft 22 connected to the first-side output side flange 18b, and the internal gear is provided on the inner periphery of the case 1. 24 is inserted along the inner circumference of the spigot portion 3a of the output side case 3 and is fixed by a pin or a key so that the plurality of planetary gears 26 externally mesh with the sun gear 23 and internally mesh with the internal gear 24. And the planet pins 27 of each planet gear 26 are supported by a carrier 28.
The output shaft 6 is connected to the output side flange 28b of the carrier 28 on the central axis without bearing support by the case 1.

The outer peripheries of the output flange 18b of the first stage and the input flange 28a and the output flange 28b of the second stage are supported on the inner periphery of the case 1 via bearings 31, 32 and 33, and the second stage. The sun gear shaft 22 is supported on the inner circumference of the second-stage output side flange 28b via a bearing 34. In particular, the outer ring of the bearing 31 arranged on the outer circumference of the output flange 18b of the first stage is fitted and supported on the inner circumferences of the spigot portions 2a and 3a of the input case 2 and the output case 3 and is fitted to the fitting portion. A precise spigot joint is formed, and after the fitting, the input side case 2 and the output side case 3 are fixed with bolts 7.

Incidentally, each planetary gear mechanism 11 to the case 1,
The interior of 21 is preferably carried out sequentially from the output side to the input side, in which case the above-mentioned bearings 31, 32, 33, 34 arranged at predetermined positions serve for accurate positioning and support of the respective parts. Together with the bearing 31, which constitutes the spigot joint, in particular, the planetary gear mechanisms 11, 21 and the input shaft 4
Also, it contributes to positioning for obtaining the coaxiality of the output shaft 6 and the like.

FIG. 3 is a sectional view of a conventional planetary gear reducer. In this figure, this conventional example has the same basic configuration as that of the two-stage planetary gear mechanisms 11 and 21 as in Example 1, but the case 1 is connected to the input side case 2, the intermediate case 8 and the intermediate case 8. It is composed of the output side case 3, and there is no bearing in the spigot joints. The outer circumference and the inner circumference of the first stage carrier 18 and the second stage carrier 28 are the case 1 inner circumference and the sun gear shaft 22. The configuration is different from that of the first embodiment in that it is not supported via bearings and that the output shaft 6 is supported by the case 1 via two rows of front and rear bearings 9.

[Second Embodiment] FIG. 2 is a sectional view of a small planetary gear reducer according to a second embodiment of the present invention. In the figure,
The second embodiment is the same as the first embodiment in the basic configuration of the two-stage planetary gear mechanisms 11 and 21, but the input shaft 4 integrated with the rotating shaft of the flat motor 9 is provided without the bearing support by the case 1. That is connected to the sun gear shaft 12 of the first stage, that the outer periphery of the output-side flange 18b of the first stage is not supported by the inner periphery of the case 1 via the bearing, and that of the second stage sun gear shaft 22 is the bearing 35 and the bearing 36. The points supported on the inner circumferences of the second-stage input side flange 28a and the second-stage input side flange 28b, respectively, and the outer ring of the bearing 32 arranged on the outer circumference of the second-stage input side flange 28a are the input side case 2 Also, the configuration is different from that of the first embodiment in that it is fitted and supported on the inner periphery of each of the spigot portions 2a and 3a of the output side case 3, and a precise spigot joint is formed at the fitted portion.

Since the operation of the second embodiment is basically the same as that of the first embodiment, detailed description thereof will be omitted.

[0024]

Since the small planetary gear reducer according to claim 1 of the present invention is configured as described above, a high tolerance accuracy is provided in the fitting structure between the outer ring of the bearing and the inner periphery of each spigot of the case. In addition to being obtained, coaxiality can be easily obtained for each element of each planetary gear mechanism, and the planetary gear mechanism is accurately positioned with respect to the case at the same time as the above fitting, which enables precise and workable assembly. Become.

In the small planetary gear reducer of claim 2,
The internal gear can be easily attached to the case, and a high tolerance precision can be obtained in the mounting process of the internal gear in combination with the fitting structure having a high tolerance precision between the outer ring of the bearing and the inner circumference of each spigot portion of the case.

In the small planetary gear reducer of claim 3,
The carrier is stably supported in the case via the two rows of front and rear bearings, and the output shaft can be shortened and the device can be miniaturized. In addition, the arrangement of each bearing enables accurate adjustment of each element of each planetary gear mechanism. Positioning becomes easy.

Further, in the small planetary gear reducer according to the fourth aspect of the invention, the carrier of the stage and the carrier of the preceding stage are stabilized to suppress the runout of the carrier shaft, and the arrangement of each bearing allows the planetary gears to be arranged. Accurate positioning of the various elements of the mechanism is facilitated, thus resulting in less vibration noise, longer life and high speed rotation.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a small planetary gear reducer according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a small planetary gear reducer according to a second embodiment of the present invention.

FIG. 3 is a cross-sectional view of a planetary gear reducer according to a conventional example.

[Explanation of symbols]

 1 case 2 input side case 2a inlay part 3 output side case 3a inlay part 4 input shaft 6 output shaft 11 planetary gear mechanism 13 sun gear 14 internal gear 16 planet gear 17 planet pin 18 carrier 21 planetary gear mechanism 23 sun gear 24 Toothed gear 26 Planetary gear 27 Planetary pin 28 Carrier 31 Bearing

Claims (4)

[Claims] 1. An internal gear that is externally meshed with a sun gear that is rotationally driven on a central axis and is fixed to the case, the case including an input-side case and an output-side case connected between the spigot parts. A planetary gear mechanism of one or more stages in which the revolution movements of a plurality of internally meshing planetary gears are transmitted to the carrier via each planet pin is internally provided between the input shaft and the output shaft on the central axis. In a planetary gear reducer, the small planetary gear reducer is characterized in that a bearing is arranged on the outer periphery of a specific carrier, and the outer ring of the bearing is fitted and supported on the inner periphery of the spigot portion of the input side case and the output side case. Machine. 2. The small planetary gear reducer according to claim 1, wherein the internal gear is inserted into the case at a predetermined position along the inner circumference of the spigot. 3. The small planetary gear reducer according to claim 1, wherein at least the outer periphery of the final stage carrier is supported on the inner periphery of the case via bearings on both sides sandwiching the planetary gear. 4. The sun gear shaft of the stage integrated with the preceding stage carrier is supported via a bearing on the inner circumference of the carrier at least on the output side of the carriers on both sides of the planetary gear. Small planetary gear reducer described.