JPH0434267Y2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Industrial Application Field The present invention relates to a planetary gear device consisting of two sets of internal gears, a pinion carrier, and a sun gear.

(b) Conventional technology For example, as a conventional planetary gear device,
There is one shown in Publication No. 183168. The planetary gear device shown here has an internal gear, a pinion carrier, and a sun gear, which are arranged on the outer periphery of a rotating shaft. The sun gear is rotatably supported on the rotating shaft via a bush. This allows the sun gear to be centered and supported in the radial direction. Further, the internal gear is centered and supported by a flange portion that is integral with the rotating shaft.

(c) Problems to be Solved by the Invention However, the conventional planetary gear device as described above has a problem in that the diameter of the sun gear cannot be made smaller than a predetermined value. In other words, the rotating shaft has a diameter necessary to transmit a predetermined torque, and a sun gear is supported on the outer periphery of the shaft via a bushing. It has a thickness. For this reason, the outer diameter of the sun gear cannot be made smaller than a predetermined value, and the selectable gear ratios for a predetermined internal gear are limited.

Note that Japanese Utility Model Application Publication No. 50-85679 shows a planetary gear device in which a bushing is not arranged on the inner diameter of the sun gear, but in this case, the coupling strength between one pinion carrier and the rotating shaft is There is a problem that the gear cannot be sufficiently lubricated. The present invention aims to solve these problems.

(d) Means for solving the problems The planetary gear device according to the present invention includes the first internal gear 14, the first pinion carrier 18, and the first
A first planetary gear set 10 including a sun gear 20 and a second planetary gear set 12 including a second internal gear 22, a second pinion carrier 26, and a second sun gear 28 are arranged on the outer periphery of the rotating shaft 30, The first sun gear and the second sun gear are integrally formed, and the first internal gear, the second internal gear, the first pinion carrier, and the second pinion carrier are connected to the rotating shaft, or a shaft or hole concentric thereto. It is centered and supported, and the first
The sun gear and the second sun gear have no centering structure other than gear meshing, and a clearance 31 is provided between the inner diameter portions of the first sun gear and the second sun gear and the rotating shaft to prevent them from coming into contact with each other. The first sun gear has a larger diameter than the second sun gear, and the first pinion carrier and the rotating shaft are connected by a spline 90, and a part of this spline is connected to the first sun gear in the axial direction. The sun gear has oil holes 72, 74, 7 that communicate from the inner diameter side to the outer diameter side.
6 is provided, and oil reservoir portions 70, 78, and 80 for supplying oil to the oil holes are formed in the sun gear inner diameter portion. Note that reference numerals in parentheses indicate corresponding members in the embodiments described later.

(E) Function A clearance is provided between the inner diameter of both sun gears and the rotating shaft, and this clearance shall be the minimum size that will prevent the two from coming into contact even if the sun gears become eccentric due to gear backlash, etc. be able to. Therefore, the inner diameter of the sun gear can be made smaller compared to the case where a bush is disposed, and the outer diameter of the sun gear can be made smaller accordingly.
This allows a larger gear ratio to be obtained. In addition, since the spline that connects the first pinion carrier and the rotating shaft is located on the inner diameter of the first sun gear, even if the axial length of the spline is increased to ensure the necessary strength, the entire planetary gear The axial dimension of will not increase. Since this spline is disposed on the side of the large-diameter first sun gear, the thickness of the sun gear can be ensured, and problems regarding strength will not occur. Furthermore, since the sun gear is provided with an oil reservoir and an oil hole, sufficient lubrication can be achieved.

(F) Embodiment FIG. 1 shows a planetary gear device of a power transmission mechanism for an automatic transmission according to an embodiment of the present invention, and FIG. 2 shows a skeleton diagram of the entire structure of this power transmission mechanism. First, the overall structure of the power transmission mechanism of the automatic transmission shown in FIG. 2 will be explained. This power transmission mechanism includes an input shaft 93 to which rotational force from an engine output shaft 91 is transmitted via a torque converter 99;
The rotating shaft 30, which is an output shaft that transmits the driving force to the final drive device, the first planetary gear set 10, the second planetary gear set 12, the multi-disc clutch 58, the multi-disc clutch 95, the multi-disc brake 49, the one-way clutch 46, and It has a band brake 97. These members are connected as shown in FIG. 2, and the first planetary gear set 10, second planetary gear set 12, etc. have a structure as shown in FIG. (described later). This power transmission mechanism can realize three forward speeds and one reverse speed by operating the clutches 58 and 95, the brakes 49 and 97, and the one-way clutch 46 in combination as shown in the table shown in FIG. In addition, such a power transmission mechanism itself is
For example, JP-A-54-132062, JP-A-60-
This is shown in Publication No. 82448, etc.

Next, based on FIG. 1, the first planetary gear set 1
0, the specific structure of the second planetary gear set 12, etc. will be explained.

The first planetary gear set 10 is the first internal gear 1
4, a first pinion carrier 18 that rotatably supports the first pinion gear 16, and a first sun gear 2.
It is composed of 0. Further, the second planetary gear set 12 includes a second internal gear 22, a second pinion carrier 26 that rotatably supports the second pinion gear 24, and a second sun gear 28. The first sun gear 20 and the second sun gear 28 are integrally formed. The first sun gear 20 has a larger diameter than the second sun gear 28. The first sun gear 20 and the second sun gear 28 are hollow, and a rotating shaft 30 passes through the inner diameter portions. 1st
A gap 31 is formed between the inner diameter portions of sun gear 20 and second sun gear 28 and the outer diameter portion of rotating shaft 30 so that the two do not come into contact with each other. An oil reservoir portion 70 formed by a recessed groove is provided at the center of the inner diameter portion of the first sun gear 20 and the second sun gear 28. An oil hole 72 is provided so as to communicate with the oil reservoir 70. Oil holes 74 and 76 are also provided in the first sun gear 20 and the second sun gear 28. The oil holes 74 and 76 also communicate with the oil reservoir 78 and the oil reservoir 80.
A connecting drum 32 is connected to the first sun gear 20 so as to rotate together with the first sun gear 20, and the axial position of the connecting drum 32 is regulated by a ring 34 and a snap ring 36. A needle bearing 38 is provided at the end of the first sun gear 20,
This supports the thrust force between the first sun gear 20 and the first pinion carrier 18. Further, a needle bearing 40 is provided at the end of the second sun gear 28, thereby supporting the thrust force between the second sun gear 28 and the flange 42. The flange 42 has its outer diameter connected to the second internal gear 22 so as to rotate together with the second internal gear 22, and its axial position is regulated by a snap spring 44. Further, the inner diameter part of the flange 42 is connected to the rotating shaft 30.
and spline connection. The second pinion gear rear 26 is integrally joined to the inner race 48 of the one-way clutch 46 by electron beam welding. Inner race 48 is multi-plate brake 4
It is formed integrally with the hub 50 of No. 9. The outer race 47 of the one-way clutch 46 is centered and fixed to a casing (not shown). The first pinion carrier 18 is coupled to the rotating shaft 30 by a spline 90. The spline 90 extends toward the inner diameter side of the first sun gear 20. Further, the flange 52 is also spline connected to the rotating shaft 30. A needle bearing 54 is provided between the first pinion carrier 18 and the flange 52.
is provided. The outer diameter portion of the flange 52 is coupled to the first internal gear 14 so as to rotate together with the first internal gear 14, and its axial position is regulated by a snap spring 56. A spline 60 with which a clutch plate of a multi-plate clutch 58 engages is integrally provided on the outer diameter portion of the first internal gear 14.

The first pinion carrier 18 and the second internal gear 22 rotate together with the rotating shaft 30, and the other first sun gear 20, second sun gear 28, first internal gear 14, and second pinion carrier 26 rotate together with the rotating shaft 30. It rotates independently of the brake, or is fixed by a multi-disc brake 49 or the like. As a result, the rotating shaft 30 rotates at a predetermined gear ratio relative to the rotation of the first internal gear 14 or the first sun gear 20 and the second sun gear 28.
When the first planetary gear set 10 and the second planetary gear set 12 operate as described above, the first planetary gear set 10 of the first planetary gear set 10
The internal gear 14 is supported by the rotating shaft 30 via the flange 52, and the first pinion carrier 18 is splined and supported by the rotating shaft 30, so that the first sun gear 20 is supported by the rotating shaft 30.
It is supported by meshing with the first pinion gear 16 supported by the pinion carrier 18, and no special support structure is required. Further, regarding the second planetary gear set 12, the second internal gear 22 is connected to the rotating shaft 30 via the flange 42.
Since the second pinion carrier 26 is supported by a casing (not shown) via an inner race 48, a one-way clutch 46, and an outer race 47, it provides special support for the second sun gear 28. does not require any structure. Although the first sun gear 20 and the second sun gear 28 are not supported by the rotating shaft 30, they rotate while being maintained concentrically therewith. 1st
Sun gear 20, second sun gear 28, and rotating shaft 30
A gap 31 is always maintained between the two, and there is no interference between the two. Since the gap 31 can be made as small as possible without interference between the two, the pitch diameter on the second sun gear 28 side in this embodiment can be made small. This results in
Even if the pitch diameter of the second internal gear 22 is determined, it is possible to obtain a gear ratio as large as possible. Further, since bushings for supporting the first sun gear 20 and the second sun gear 28 are not required, the cost is also reduced.

(G) Effect of the invention As explained above, according to the invention, the large and small sun gears formed integrally are each supported by meshing with the pinion gear, so that the sun gear is supported on the rotating shaft. This eliminates the need for a bushing for the sun gear, making it possible to reduce the pitch diameter of the sun gear and reducing the price. Therefore, even if the axial length of the spline is increased to ensure the necessary strength, the axial dimension of the entire planetary gear device will not increase. Since this spline is disposed on the side of the large-diameter first sun gear, the thickness of the sun gear is ensured, and no strength problems occur. Furthermore, since the sun gear is provided with an oil reservoir and an oil hole, sufficient lubrication can be achieved.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing a planetary gear system that is an embodiment of the present invention, Fig. 2 is a diagram showing the power transmission mechanism of an automatic transmission as a skeleton diagram, and Fig. 3 is a diagram showing the combination of elements that operate at each gear stage. FIG. 10...First planetary gear set, 12...Second planetary gear set, 14...First internal gear, 18...
1st pinion carrier, 20... 1st sun gear,
22...Second internal gear, 26...Second pinion carrier, 28...Second sun gear, 30...
... Rotating shaft, 31... Clearance, 70, 78, 80...
...Oil pool, 72, 74, 76...Oil hole, 90...
…spline.

Claims (1)

[Claims for Utility Model Registration] A first planetary gear set consisting of a first internal gear, a first pinion carrier and a first sun gear, and a second planetary gear set consisting of a second internal gear, a first pinion carrier and a second sun gear. and are arranged on the outer periphery of the rotating shaft, and the first sun gear and the second sun gear
In a planetary gear device formed integrally with the sun gear, a first internal gear, a second internal gear,
The first pinion carrier and the second pinion carrier are supported in a manner centered with respect to the rotating shaft, or a shaft or hole concentric therewith, and the first sun gear and the second sun gear are centered in a manner other than gear meshing. The first sun gear has no structure, and a clearance is provided between the inner diameter portions of the first sun gear and the second sun gear and the rotating shaft to prevent them from coming into contact with each other, and the first sun gear is larger than the second sun gear. The first pinion carrier and the rotating shaft are connected by a spline, and a part of the spline is located on the inner diameter of the first sun gear so as to overlap with the first sun gear in the axial direction. A planetary gear device characterized in that the sun gear is provided with an oil hole that communicates from the inner diameter side to the outer diameter side, and an oil reservoir portion that supplies oil to the oil hole is formed in the inner diameter portion of the sun gear.