JPH0526302A - Speed change gear - Google Patents

Abstract

PURPOSE:To manufacture transmissions, having a large change gear ratio and capable of miniaturization, with simple structure and moreover easily. CONSTITUTION:High-speed and low-speed rotation shafts 10 and 7 are provided on the same shaft line through a case 1, a sun gear 11 is formed on the high- speed rotation shaft 10 in the case 1, and also an internal gear 14 is fixed to the case 1 to be provided on the inner side of the case 1 corresponding to the sun gear 11. Plural epicyclic gears 18, engaged with both the internal gear 14 and the sun gear 11, are provided, small-difference gears 23 having a diameter smaller than that of the epicyclic gears 18 are fitted to one side of these epicyclic gears 18, and an internal gear 24, with which these small-difference gears 23 are engaged, is formed integrally with the low-speed rotary shaft 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planetary gear type transmission that is suitable for a transmission such as a robot and can be miniaturized.

[0002]

2. Description of the Related Art Conventionally, in order to obtain a large gear ratio in a planetary gear type transmission, a plurality of planetary gear type transmission mechanisms are connected.

[0003]

However, the device in which a plurality of sets of planetary gear type speed change mechanisms are connected as described above has a problem in that it is difficult to reduce the size because the structure is complicated.

[0004]

In order to solve the above-mentioned problems, in the present invention, a high-speed rotating shaft and a low-speed rotating shaft are provided on the same axis penetrating the case, and the high-speed rotating shaft in this case is connected to the sun. A gear is formed, and an internal gear is fixed to the case inside the case corresponding to the sun gear.
A plurality of planetary gears that mesh with both the internal gear and the sun gear are provided, and a small differential gear having a smaller diameter than the planetary gear is provided on one side of each of the planetary gears. A gear is formed by integrally forming a toothed gear with the low-speed rotating shaft.

It is further preferable that the lateral width of the planetary gear is larger than the outer diameter of the gear.

Further, in order to make the operation of the device of the present invention smooth, a high speed rotating shaft and a low speed rotating shaft are provided on the same axis through the case, and a sun gear is formed on the high speed rotating shaft in this case. An inner race having the same outer diameter as the pitch circle of the sun gear is provided on each side of the sun gear, and an internal gear is fixedly provided to the case inside the case corresponding to the sun gear. Ring-shaped outer races having the same inner diameter as the pitch circle of the toothed gear are provided on both sides of the internal gear, and a plurality of planetary gears that mesh with both the internal gear and the sun gear are provided. A pitch circle wheel having an outer diameter equal to the pitch circle of the planetary gear is provided on both sides of the gear so that the inner race and the outer race are in rolling contact with each other, and the one side of each planetary gear is idled. The small diameter of the small difference gear provided from the gear, it is preferable to form the internal gear each of these small differences gears meshing respectively with said low speed rotational shaft integrally.

[0007]

As described above, according to the present invention, a transmission having a large gear ratio and capable of being downsized can be obtained by a set of planetary gear mechanisms. Therefore, since the device of the present invention has a simple structure, it is easy to manufacture and can be easily downsized.

When the lateral width of the planetary gear is made larger than the outer diameter of the gear, the twisting phenomenon occurring in the planetary gear can be suppressed and the meshed state of the gear can be always maintained correctly.

Further, if a meshing portion of the planetary gears is provided with a rolling contact mechanism between the pitch circle wheel having the same pitch circle diameter as that of each gear and the inner and outer races, the meshing of the respective gears is always smooth and smooth. The operation of this transmission can be made smooth.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In the figure, 1 is a substantially hollow cylindrical case, 2 is a case body, 3 is a case lid, 4 is a case lid 3, and a case body 2
It is a bolt to be fastened to.

In this embodiment, the low-speed rotating shaft 7 is attached to the case body 2 via two ball bearings 5 and 6 provided in a boss portion 2a having a frusto-conical shape protruding from one side of the case body 2. A ball bearing 8 is provided at the inner end of the shaft 7 so as to penetrate therethrough and to be rotatable, and the boss portion 3a of the case lid 3 is provided.
A ball bearing 9 is provided inside the high-speed rotating shaft 1 which penetrates the case lid 3 by these ball bearings 8 and 9.
0 is provided on the same axis as the low speed rotation shaft 7.

Further, a sun gear 11 is formed on a high-speed rotating shaft 10 in the case 1, and inner races 12, 1 having the same outer diameter as the pitch circle P ₁ (see FIG. 5) of the sun gear 11 are formed.
3 is provided by fitting on the shaft 10, a hollow cylindrical internal gear 14 is provided inside the case body 2 corresponding to the sun gear 11, and the internal gear 14 is fixed by a bolt 15 screwed into the case body 2. The ring-shaped outer races 16 and 17 having the same inner diameter as the pitch circle P ₂ (see FIG. 5) of the internal gear 14 are fixed on both sides of the internal gear 14.
A plurality of (three in this embodiment) planetary gears 18 that mesh with both the internal gear 14 and the sun gear 11 are provided at equal circumferential positions. The lateral width of this planetary gear 18 is
It is better to make it larger than the outer diameter of.

On both sides of the planetary gear 18, pitch circle wheels 19, 20 having the same outer diameter as the pitch circle P ₃ of the planetary gear 18 (see FIG. 5) are provided, and the inner races 12, 13 and The outer races 16 and 17 are brought into rolling contact with each other. In the case of this embodiment, the pitch circle wheel 19 is formed integrally with the planetary gear 18, and the pitch circle wheel 20 is assembled so that the planetary gear 18 can be formed.
It is formed in a ring shape separate from the pitch gear wheel 2 by fitting it to the step portion of the planetary gear 18 and then tightening the presser disc 21 to the side surface of the planetary gear 18 with the application bolt 22.
0 is fixed to the planetary gear 18.

A small differential gear 23 having a smaller diameter than the planet gears 18 is provided on one side (left side in FIG. 1) of each planet gear 18.
Internal gear 2 with which each of these small difference gears 23 meshes
4 is formed integrally with the low-speed rotating shaft 7.

Next, the operation of the device of the present invention constructed as described above will be explained. As shown in FIG. 5, when the high-speed rotating shaft 10 rotates in the direction of arrow D, the sun gear 1 integrated with the shaft 10
Since 1 also rotates in the direction of arrow D, the planetary gear 18 meshing therewith rotates in the direction of arrow E and the internal gear 1
Since 4 is fixed, the planetary gear 18 revolves as shown by an arrow F.

When the planetary gear 18 operates in this way, the small difference gear 23 formed integrally with the planetary gear 18 also rotates in the direction of arrow E and in the direction of arrow F, as shown in FIG. Revolve around. Since the small difference gear 23 meshes with the internal gear 24, the internal gear 24 is driven by the rotation of the small gear 23 in the arrow E direction and the revolution in the arrow F direction. However, this rotation in the direction of arrow E and arrow F
Since the directional revolutions cancel each other out, the internal gear 24 becomes a very decelerated rotation. Therefore, the low-speed rotation shaft 7 integrated with the internal gear 24 is rotated at a significantly reduced speed.

Now, the number of teeth Z ₁ of the sun gear 11 is 10, the number of teeth Z ₂ of the planetary gear 18 is 20, the number of teeth Z ₃ of the internal gear 14 is 50, and the number of teeth Z _{4 of the} differential gear 23 is Z _4. Is 19, the speed reduction ratio R is expressed by the following equation. _{R = Z 1 / (Z 1} + Z 3) × {1- (Z 4 / Z 2)} = 10 / (10 + 50) × {1- (19/20)} = 10/60 × 1/20 = 1 / 120≈0.0083 That is, the reduction ratio in this case is 1/120, which is very large. From the above equation, it can be seen that in order to increase the gear ratio of this device, the difference between the number of teeth Z ₂ of the planetary gear 18 and the number of teeth Z ₄ of the small difference gear 23 should be reduced.

The above description is for the case where the input is from the high speed rotating shaft 10 side and the output is from the low speed rotating shaft 7 side. It goes without saying that the speeded-up rotation is output from the high-speed rotation shaft 10 side.

[0019]

As described above, according to the present invention, a transmission having a large gear ratio and capable of being miniaturized can be obtained by a set of planetary gear mechanisms. Therefore, since the device of the present invention has a simple structure, it is easy to manufacture and can be easily downsized.

When the lateral width of the planetary gear is larger than the outer diameter of the gear, the twisting phenomenon occurring in the planetary gear can be suppressed and the meshed state of the gear can be always maintained correctly.

Further, if a rolling contact mechanism between a pitch circle wheel equal to the pitch circle diameter of each gear and the inner and outer races is provided in the meshing portion of the planetary gear, the meshing of the gears is always reasonably and smoothly performed. The operation of this transmission can be made smooth.

Therefore, according to the present invention, it is possible to easily manufacture a transmission having a large gear ratio and a small size with a simple structure, despite the simple mechanism. can get.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of a device of the present invention.

FIG. 2 is a front view of the device of the present invention viewed from the high-speed rotating shaft side.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is a sectional view taken along line BB of FIG.

5 is a sectional view taken along line CC of FIG.

[Explanation of symbols]

1 case 2 Case body 3 case lid 4 volt 5,6 ball bearing 7 Low speed rotating shaft 8,9 ball bearing 10 High-speed rotating shaft 11 sun gear 12,13 Inner race 14 Internal gear 15 volts 16,17 outer race 18 planetary gears 19,20 pitch circle wheel 21 Presser disk 22 volts 23 Small differential gear 24 Internal gear

Claims (3)

[Claims] 1. A high-speed rotating shaft and a low-speed rotating shaft are provided on the same axis line through the case, a sun gear is formed on the high-speed rotating shaft in the case, and the sun gear is internally formed in the case corresponding to the sun gear. A toothed gear is fixedly provided on the case, a plurality of planetary gears that mesh with both the internal gear and the sun gear are provided, and a small differential gear having a smaller diameter than the planetary gear is provided on one side of each of the planetary gears. 2. An internal gear, which meshes with each of the small difference gears, is integrally formed with the low-speed rotation shaft. 2. The transmission according to claim 1, wherein the lateral width of the planetary gear is larger than the outer diameter of the gear. 3. A high-speed rotating shaft and a low-speed rotating shaft are provided on the same axis penetrating the case, a sun gear is formed on the high-speed rotating shaft in the case, and a pitch circle of the sun gear is arranged on both sides of the sun gear. And inner races each having an outer diameter of the same diameter as that of the sun gear and an inner gear fixed to the inner side of the case corresponding to the sun gear, and having an inner diameter equal to the pitch circle of the inner gear. Ring-shaped outer races are provided on both sides of the internal gear, and a plurality of planet gears that mesh with both the internal gear and the sun gear are provided. A pitch circle wheel having an outer diameter is provided so as to make rolling contact with the inner race and the outer race, respectively.
A transmission gear characterized in that a small differential gear having a diameter smaller than that of the planetary gear is provided on one side of each planetary gear, and an internal gear to which each of these small differential gears meshes is integrally formed with the low-speed rotation shaft. .