JPH07150925A - Breather - Google Patents

Abstract

PURPOSE:To provide a breather device wherein a breather can be arranged without forming any hole on a casing, and lubricating oil is not leaked to the outside even if a rotational part such as a gear is rotated at high speed by adopting the simple structure. CONSTITUTION:In a breather wherein a breather passage 4 formed by an axial thin hole to be communicated with the inside and the outside of a casing is provided on the shaft core of a rotary shaft 3 journalled by penetrating a casing 6, a presser plate 1 wherein radial breather grooves 2 are formed on an end surface 5 on the casing inside of the rotary shaft 3 so as to be communicated. with the breather passage 4, drops of lubricating oil are returned into the casing by air flow generated by the pump action of the radial breather grooves 2 when the rotary shaft 3 is rotated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a breather, which does not need to be provided with a hole or the like in a casing, can sufficiently prevent oil leakage to the outside, and has good breathability. Is.

[0002]

2. Description of the Related Art In a case where a gear device is provided in a casing, the pressure in the casing rises due to the rise in temperature due to the friction heat generated when the gears mesh with each other. May be leaked.
Further, as the gear rotates, the lubricating oil attached to the gear may be scattered by the centrifugal force and leak to the outside of the casing. For this reason, conventionally, in this type of gear device, a breather device that communicates the inside and the outside of the casing is provided in order to prevent an increase in pressure due to a temperature increase in the casing. As such a conventional example, for example, there is one described in Japanese Utility Model Laid-Open No. 61-116265. In this example, the vehicle final reduction gear is provided with a breather that communicates the inside and outside of the casing, and the small chamber immediately inside the breather and the oil-tight chamber are connected by a passage to increase the temperature in the casing when the gears are meshed. The lubricating oil in the oil-tight chamber is sucked into the small chamber due to the pressure difference between the increased pressure and the external pressure in the small chamber, and the bearing can be strongly lubricated by the lubricating oil. However, in such a conventional breather device, it is necessary to form a hole in the casing in order to install the breather, which causes a reduction in the strength of the casing. In addition, the lubricating oil from the rotating parts such as the bearing may be directly scattered from the breather to the outside by the high speed centrifugal force, or may be jetted to the outside from the small chamber having a low pressure. Further, in order to prevent those lubricating oils from directly scattering from the breather to the outside due to centrifugal force, it is necessary to further complicate the structure of the breather.

[0003]

Therefore, according to the present invention, it is possible to eliminate the inconveniences of the above-described conventional breather device and install the breather without forming a hole or the like in the casing. By adopting a simple configuration, a breather device is provided in which lubricating oil does not leak to the outside of the casing even when a rotating part such as a gear rotates at a high speed.

[0004]

Therefore, in the present invention, as a means for solving the above-mentioned conventional problems, an axial direction in which the shaft center of a rotary shaft that penetrates the casing and is axially supported communicates with the inside and outside of the casing. With the provision of a breather passage consisting of pores, a pressing plate having a radial breather groove engraved so as to communicate with the breather passage is fixed to the end surface of the rotating shaft on the casing inner side. The radial breather groove may be configured such that the groove cross-sectional area gradually decreases from the central portion toward the outer peripheral portion.

[0005]

According to the present invention, the radial breather grooves 2 of the pressing plate 1 fixed to the end surface 5 of the rotary shaft 3 as described above communicate with the breather passage 4 provided at the axial center of the rotary shaft 3. When the rotating shaft such as the input shaft 3 is rotated at a high speed, the radial breather groove 2 diffuses air in the outer peripheral direction by the pumping action of the centrifugal force, so that the breather groove 2 or the inlet of the breather passage 4 is provided. The lubricating oil that has penetrated into the casing is pushed back into the casing, which assists the centrifugal force of the lubricating oil to diffuse into the casing. Further, even if a lubricating oil drop tries to leak outward from the breather passage 4 while the casing internal pressure is still high after the rotation shaft 3 is stopped, it is impossible for the pressing plate 1 to directly escape to the breather passage 4. It must go through the radial breather groove 2 orthogonal to the breather passage 4, and the chance of leakage almost disappears. Therefore, by making a hole in the casing,
Without installing a breather with a complicated structure, it is possible to surely prevent leakage of lubricating oil and secure sufficient ventilation performance by drilling holes in the axis of the rotating shaft and fixing the pressing plate that is easy to manufacture. A breather device that does this can be provided.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment provided with a breather of the present invention used for an engine accessory or the like, and (A) is an overall view of a vicinity of a rotary shaft provided with the breather of the present invention,
(B) is a perspective view of a pressing plate which constitutes a main part of the breather of the present invention. Bearing 7 penetrating through casing 6
A breather passage 4 composed of axial pores communicating with the inside and outside of the casing 6 is provided at the axis of the rotating shaft 3 which is rotatably supported via. At the inside of the casing of the rotary shaft 3, an input gear 1 for transmitting a driving force from a deceleration or speed increasing device (not shown) to an auxiliary machine.
3, an input pulley 10 supported on the outside of the casing 6 via a bearing 7 is spline-fitted to the outside, and is fixed by a pulley fixing bolt 9. A seal ring 8 blocks the inside and outside of the casing 6. A pressing plate 1 having a radial breather groove 2 ... Engraved therein is fixed to an end surface 5 of the rotating shaft 3 on the inner side of the casing so as to communicate with the breather passage 4 to form a breather. Reference numeral 12 denotes a screw hole for fixing the pressing plate 1 to the end surface 5 of the rotary shaft 3 on the inner side of the casing with a mounting screw 11.

Next, the operation of the first embodiment of the present invention thus constructed will be described. The radial breather grooves 2, ... Of the pressing plate 1 fixed to the end surface 5 of the rotary shaft 3 rotate as described above. Since it is constructed so as to communicate with the breather passage 4 provided at the shaft center of the shaft 3, when the rotating shaft such as the input shaft 3 rotates at high speed, the radial breather grooves 2 ... Is diffused in the outer peripheral direction to push back the lubricating oil that has infiltrated to the vicinity of the inlet of the breather groove 2 ... Or the breather passage 4 back into the casing, helping to disperse the lubricating oil into the casing due to the centrifugal force. . Further, even if a lubricating oil drop tries to leak outward from the breather passage 4 while the casing internal pressure is still high after the rotation shaft 3 is stopped, it is impossible for the pressing plate 1 to directly escape to the breather passage 4. The radial breather groove 2, ... Orthogonal to the breather passage 4 has to be passed, and the chance of leakage almost disappears.

Next, a second embodiment of the present invention will be described. 2 is fixed to the end surface 5 of the rotary shaft 3 on the inner side of the casing and communicates with the breather passage 4 so as to form a breather. Is a perspective view of a modified example of the pressing plate 1 in which the breather grooves 2 ...
Is configured such that the groove cross-sectional area gradually decreases from the central portion toward the outer peripheral portion.

In the second embodiment, the radial breather grooves 2 provided on the pressing plate 1 are constructed so that the groove cross-sectional area gradually decreases from the central portion toward the outer peripheral portion. The pressing plate 1 that rotates with the rotation of the rotating shaft 3
Since the speed in the air inside the breather groove 2 ... increases as it flows in the outer peripheral direction by the pumping action due to the rotational centrifugal force, a strong push-back of the invading lubricating oil into the casing,
Dispersion of the lubricating oil into the casing due to the centrifugal force is sufficiently assisted by the inclined walls of the breather grooves 2 ... Each of which the groove width gradually decreases. Of course, the breather of the present invention described above may be adopted not only in the engine auxiliary machine but also in a device having a gear in the casing of this kind.

[0010]

As described above, according to the present invention, it is possible to form and make a hole in the axis of the rotating shaft without forming a hole in the casing or installing a breather having a complicated structure. By easily fixing the pressing plate, it is possible to provide a breather device that can surely prevent leakage of lubricating oil and ensure sufficient ventilation performance.

[Brief description of drawings]

1A and 1B show a first embodiment in which a breather of the present invention is applied, FIG. 1A is an overall view of the vicinity of a rotary shaft to which the breather of the present invention is applied, and FIG. 1B is a breather of the present invention. It is a perspective view of the press plate which comprises the principal part of.

FIG. 2 is a perspective view of a pressing plate 1 according to a second embodiment of the present invention.

[Explanation of symbols]

 1 Holding plate 2 Breather groove 3 Rotating shaft 4 Breather passage 5 End face 6 Casing 7 Bearing 8 Seal ring 9 Pulley fixing bolt 10 Input pulley 11 Mounting screw 12 Screw hole 13 Input gear

Claims (2)

[Claims] 1. A breather passage formed of axial pores communicating with the inside and outside of the casing is provided at the axis of a rotating shaft that is pierced through the casing, and the end face of the rotating shaft on the inner side of the casing is provided with the breather passage. The breather is characterized in that a pressing plate having a radial breather groove is fixed so as to communicate with the breather passage. 2. The breather according to claim 1, wherein the radial breather groove is configured such that the groove cross-sectional area gradually decreases from the central portion toward the outer peripheral portion.