JP2712895B2 - Air breather for planetary gear transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air breather for a planetary gear type transmission.

[0002]

2. Description of the Related Art As a conventional planetary gear type transmission, for example, there is one shown in FIG. This is because the rotation input from the input shaft 8 and the sun gear 6 rotates the pinion gear 10 interposed between the ring gear 68 fixed to the case 84 and connects with the pinion carrier 12 holding the pinion gear 10. The output shaft (not shown) performs reduced rotation in the same direction as the input shaft 8.

A lubricating oil is sealed in the case 84 to perform lubrication, absorb heat, and reduce noise.

As a result, the temperature inside the case 84 rises due to friction between the gears and the like, and the air expands, causing the case 8 to expand.
If the pressure in the case 4 is too high, the lubricating oil may leak to the outside from the joint of the case 84 or the connecting portion between the case 84 and the input / output shaft. Provided.

[0005] Inside the case 84, lubricating oil is atomized by agitation due to rotation of the gears 6 and 10, and the case 8
If the breather pipe 18 is provided directly on the case 4, the lubricating oil in the form of mist blows out of the case 84 from the breather pipe 18, so that, for example, as disclosed in JP-A-60-215158, Air chamber 66 at 84
If necessary, a baffle plate 63 is attached between the air chamber 66 and the case 84, and the breather pipe 18 is provided in the air chamber 66 so that the lubricating oil directly reaches the breather pipe 18, Did not blow out.

[0006]

However, in the above-mentioned conventional air breather 79, only a part of the case 84 has a convex portion protruding in the axial direction by the volume of the air chamber 66.
Due to the structure that is not preferable in terms of space efficiency, there is a problem that design and manufacturing restrictions are likely to occur on the entire device using the planetary gear type transmission so as not to interfere with the convex portion, and thus the cost is increased. there were.

The present invention has been made in view of such a point, and an object of the present invention is to provide a structure with good space efficiency without providing an air breather with a convex portion such that only a part of a case projects.

[0008]

Means for Solving the Problems To achieve the above object, an invention according to claim 1 includes a first shaft inserted into a case, a sun gear connected to the first shaft, A ring gear fixed to the case, a pinion gear interposed between the sun gear and the ring gear, a pinion carrier holding the pinion gear, inserted into the case, and connected to the pinion carrier. A planetary gear transmission comprising a second shaft and a lubricating oil sealed in the case, wherein the air gear of the planetary gear transmission communicates between the inside and outside of the case. An air chamber is provided therebetween, a first communication means for communicating the air chamber with the outside of the case is provided in the case, and a second communication means for communicating the air chamber and the inside of the case is provided with the ring gear. Or those provided on at least one of said case.

According to a second aspect of the present invention, there is provided an air breather according to the first aspect, wherein an air chamber provided between the ring gear and the case is provided at an outer peripheral portion of the ring gear. Are provided in the groove.

[0010]

In the planetary gear type transmission according to the first aspect of the present invention, when the temperature inside the case rises and the air inside the case expands, the air containing the mist-like lubricating oil inside the case is removed. The second communication means discharges the air into the air chamber, and the mist lubricating oil is returned to the liquid in the air chamber, and the air is discharged outside the case through the first communication means. Conversely, when the temperature inside the case decreases and the air inside the case shrinks, the air outside the case is sucked into the air chamber from the first communication means, and is sucked into the case from the air chamber through the second communication means. .

[0011] In the planetary gear type transmission according to the second aspect of the invention, when the temperature in the case rises and the air in the case expands, the air in the case is moved from the second communication means to the outer periphery of the ring gear. The air is discharged to the air chamber formed by the groove of the portion, and is discharged from the air chamber to the outside of the case through the first communication means. Conversely, when the temperature inside the case decreases and the air inside the case shrinks, the air outside the case is sucked into the case from the first communication means into the air chamber through the second communication means from the air chamber.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 show an embodiment of the present invention.
FIG. 1 is an axial sectional view of a planetary gear type transmission 1. That is, the case 4 includes the outer peripheral portion of the substantially disk-shaped portion 24b and the cylindrical
The first member 24 is integrally formed with one end of the cylindrical member 24a, and the outer periphery of a substantially disk-shaped second member 34 is fastened to the other end of the cylindrical portion 24a with bolts 30. A sealing material 32 is provided at the fastening portion.

At the center of the first member 24 and the second member 34, there are provided convex portions 24c and 34c protruding outside the case 4. The convex portion 24c of the first member has a hole so that the input shaft can be inserted, and the convex portion 3c of the second member 34 is formed.
4c has a hole so that the output shaft can be inserted.
An outer peripheral portion of a ring gear 28 is fixed to an inner peripheral portion of the cylindrical portion 24a, and a pin 26 is provided and fastened to the substantially disk-shaped portion 24b. The outer periphery of the ring gear 28 is provided with a groove 15 cut in a substantially U-shape in the circumferential direction, and an air chamber 16 is formed between the case 4 and the ring gear 28.

An input shaft (first shaft) 8 is inserted into a hole provided in the convex portion 24c. A bearing 38 is interposed between the input shaft 8 and the convex portion 24c. A sealing material 40 is provided.

The input shaft 8 inserted in the case 4 is provided with a sun gear 6, which is in a cylindrical space formed by the ring gear 28.

A pinion gear 10 is provided between the sun gear 6 and the ring gear 28.
28. The pinion gear 10 has a pinion shaft 10a fixed to a pinion carrier 12, and a rotatable pinion gear 10b provided on the pinion shaft 10a via a bearing 10c.

The pinion carrier 12 includes a disk-shaped portion 12a to which the pinion shaft portion 10a is fixed, and the disk-shaped portion 1a.
2a has a shape in which one end of the cylindrical portion 12b is fitted to the inner peripheral portion. A bearing 36 is interposed between the cylindrical portion 12b and the second member 34, and the cylindrical portion 12b is A spline 12e for fitting an output shaft (second shaft) (not shown) is formed in the inner peripheral portion.

A breather pipe (first communication means) 18 for communicating the air chamber 16 with the outside of the case 4 is provided above the cylindrical portion 24a of the first member 24. A lubricating oil (not shown) is enclosed in the case 4.

FIG. 2 shows a cross section taken along line AA in FIG.
FIG. 3 shows a BB cross section in FIG. That is, in order to allow the air chamber 16 to communicate with the inside of the case 4, the ring gear 28 has a groove (second communication means) 51 and the second member 3.
4, grooves (second communication means) 52 are provided at three places: below the case 4, above the right side, and above the left side. The groove 51 is provided in a portion in contact with the case 4, and a groove 52 is provided in the second member 34 so that the groove 51 and the case 4 communicate with each other.

That is, the inside of the case 4 and the outside of the case 4 are communicated by the air breather 77 including the breather pipe 18, the air chamber 16, the groove 51, and the groove 52.

The rotation of the input shaft 8 is transmitted to a pinion gear 10 meshing with the sun gear 6, and the pinion gear 10 rotates in a direction opposite to that of the sun gear 6. The pinion carrier 12 is decelerated and rotates in the same direction as the sun gear 6.
A lubricating oil (not shown) is sealed in the case 4 and is stirred by the rotation of the sun gear 6 and the pinion gear 10, and a part of the lubricating oil is in a mist state.

With the above configuration, when the temperature inside the case 4 rises and the air inside the case 4 expands, the air containing the mist-like lubricating oil inside the case 4 is discharged from the grooves 52 and 51 to the air chamber 16. . In the air chamber 16, the atomized lubricating oil is returned to the liquid, and the air is discharged outside the case 4 through the breather pipe 18. The lubricating oil returned to the liquid is
It returns into the case 4 through the lower grooves 51 and 52. Here, since the distance between the breather pipe 18 and the grooves 51 and 52 is sufficiently long, the air containing the mist-like lubricating oil discharged from the grooves 51 and 52 to the air chamber 16 reaches the breather pipe 18. By this time, the lubricating oil returns to the liquid in the air chamber 16 and is prevented from being discharged from the breather pipe 18 to the outside of the case 4.

Conversely, when the temperature inside the case falls and the air inside the case 4 shrinks, the air outside the case 4 is sucked into the air chamber 16 from the breather pipe 18 and passes through the grooves 51 and 52 from the air chamber 16. It is sucked into the case 4.

As described above, the air breather of this embodiment has a structure in which only a part of the case does not have a protruding portion as in the prior art, so that the space efficiency is improved, and the degree of freedom in designing and manufacturing the entire apparatus is improved. And the cost can be reduced.

Further, in the present embodiment, the groove 15 is formed to provide the air chamber 16 on the outer periphery of the ring gear 28,
The rigidity of the ring gear 28 is reduced, so that the tooth contact between the ring gear 28 and the pinion gear 10 can be improved, and there is also an effect of reducing noise and vibration generated from the planetary gear shift.

In the present embodiment, the breather pipe 18 is formed on the upper part of the case 4. However, the breather pipe 18 is not limited to the upper part of the case 4, and may be provided anywhere on the case 4 if it is not directly immersed in the lubricating oil. Is also good. At this time, if the mist lubricating oil reaches the breather pipe 18, it can be prevented by providing a baffle plate or the like.

The air chamber 16 formed by the groove 15 provided in the ring gear 28 may also be formed by providing a groove in the inner peripheral portion of the case 4, for example, in order to secure the rigidity of the case 4. Even if it is necessary to increase the wall thickness, the rate of increase in the outer diameter of the case 4 is small, and there is almost no restriction on the design and manufacturing as compared with the conventional structure in which the convex portions are provided. Of course, by forming the air chamber 16 by the groove 15 provided on the outer peripheral portion of the ring gear 28 and the groove provided on the inner peripheral portion of the case, the capacity of the air chamber can be increased.

In this embodiment, the input shaft 8 and the sun gear 6 are provided integrally, but they may be provided separately.

[0030]

As described above, in the planetary gear type transmission according to the first aspect of the present invention, the air chamber for the air breather is provided between the ring gear and the case. A device that uses a planetary gear type transmission, which is advantageous in terms of space efficiency as compared to a case in which an air chamber is formed by providing a convex part in a part of the case to provide an air breather like the planetary gear type transmission The overall design and manufacturing flexibility are increased, and costs can be reduced.

In the planetary gear type transmission according to the invention set forth in claim 2, in addition to the above effects, the rigidity of the ring gear is reduced, and the contact between the ring gear and the pinion gear is improved. Therefore, noise and vibration emitted from the planetary gear type transmission can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a planetary gear type transmission to which the present invention is applied.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is a sectional view taken along line BB in FIG. 2;

FIG. 4 is a sectional view of a conventional planetary gear type transmission.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Planetary gear type transmission, 4, 84 ... Case, 6 ... Sun gear, 8 ... Input shaft (1st shaft), 10 ... Pinion gear, 12
... pinion carrier, 15 ... groove, 28, 68 ... ring gear, 16, 66 ... air chamber, 18 ... breather pipe (first
Communication means), 51 ... groove (second communication means), 52 ... groove (second communication means), 77, 79 ... air breather.

Claims (2)

(57) [Claims] 1. A first shaft inserted into a case, a sun gear connected to the first shaft, a ring gear fixed to the case, and a pinion interposed between the sun gear and the ring gear. A planetary gear type transmission comprising: a gear; a pinion carrier that holds the pinion gear; a second shaft inserted into the case and connected to the pinion carrier; and lubricating oil sealed in the case. An air breather for a planetary gear type transmission that communicates between the inside and outside of the case, wherein an air chamber is provided between the ring gear and the case, and the first communication communicates the case with the air chamber and the outside of the case. A planetary gear type wherein a second communication means for communicating the air chamber with the inside of the case is provided on at least one of the ring gear and the case. Air breather of the speed machine. 2. An air breather for a planetary gear transmission according to claim 1, wherein an air chamber provided between said ring gear and said case is provided.
An air breather for a planetary gear type transmission, characterized in that the groove is formed in an outer peripheral portion of a ring gear.