JPS60215158A - Air-breather for transmission - Google Patents

Abstract

PURPOSE:To eliminate a leak of lubricating oil, by forming a vent hole in a casing end face, making a baffle plate extend from the casing end face to the inside, while forming an air chamber in the outside of the vent hole, and connecting an air pipe to the air chamber. CONSTITUTION:A vent hole 9 is formed in an end face of a casing 10, while a baffle plate 13 is made to extend from the end face of the casing 10 to the inside so as to cover the scattering direction of lubricating oil, then an air chamber 16 is formed in the outside of the vent hole 9, and an air pipe 12, leading to the atmosphere, is connected to this air chamber 16. With this constitution, a possible flow of the lubricating oil into the air chamber 16 is checkable before it happens, so that a leak of the oil out of the air pipe 12 is surely precentable from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention provides for exposing the inside of a casing of an automobile transmission, etc. to the atmosphere.
This invention relates to an air breather for a transmission that conducts electricity.

(Prior Art) Conventionally, in a transmission for an automobile, an air breather is installed at a position where lubricating oil is difficult to scatter in order to conduct the inside of the transmission casing to the atmosphere.

Figure 1 shows a partial cross-section of an example of a conventional air breather structure, taking an auxiliary transmission for a four-wheel drive vehicle as an example.
The engine power transmitted to the drive shift shaft 1 is transferred to a two-wheel drive state in which power is transmitted only to the rear drive shaft 3 by a two-wheel/four-wheel switching device inside the casing 2, or a two-wheel drive state in which power is transmitted only to the rear drive shaft 3, or a rear drive shaft 3 and a front drive shaft 4.
The vehicle is switched to a four-wheel drive state in which power is transmitted to both of the front wheels, and the power is transmitted from the front 1 to the drive shaft 4 by rotating a sprocket 5 on the rear drive shaft 3 and driving a chain 6 meshed with this sprocket 5. There is.

The air breather that conducts the inside of the casing 1 to the atmosphere has a ventilation hole 9 formed in the casing end face 8 at the mounting part of the bearing 7 that supports the rear drive shaft 3, and a ventilation hole 9 formed on the outside of this ventilation hole 9 by attaching another casing 10. The air chamber 11 is formed into a partition, and a downward U-shaped air pipe 12 communicating with the outside is connected to the air chamber 11.

However, in the structure of such a conventional air breather, the lubricating oil is scattered by the rotational drive of the chain 6 and directly lands on the inner wall of the casing end 8 in which the vent hole 9 is formed. There is a problem in that lubricating oil flows into the air chamber 11 through the ventilation hole 9 and accumulates therein, and leaks out from the air pipe 12.

(Object of the Invention) The present invention has been made in view of such conventional problems, and provides an air breather for a transmission that allows the inside of the casing to be communicated to the atmosphere without causing leakage of lubricating oil. The purpose is to

(Structure of the invention) To achieve this object, the present invention provides an air breather for a transmission that communicates the inside of the casing with the atmosphere, in which a ventilation hole is formed in the end face of the casing, and lubricating oil is scattered toward the ventilation hole when the gear rotates. A baffle plate is extended inward from the casing to cover the entire direction, an air chamber is formed outside the ventilation hole, and an air pipe communicating with the atmosphere is connected to the air chamber.

(Embodiment) FIG. 2 is a cross-sectional explanatory view showing an embodiment of the present invention at a portion of a casing where an air breather is attached.

First, to explain the configuration, 2 is a casing with a casing end face 8, and there is another casing 2' on the left side of the casing 2, and another casing 1 on the right side of the casing 2.
0 is installed. A rear drive shaft 3 is rotatably mounted inside the casing 2 while being supported by a bearing 7, and a sprocket (~5) is provided on the rear drive shaft 11 and the foot 3 is relatively rotatable, and a chain 6 is engaged with the sprocket 5. Power is transmitted to a front drive shaft (not shown).

A ventilation hole 9 is provided in the axial direction in the casing end surface 8 which is the upper right side of the chain 6, and the casing end surface 8 is provided in a direction that prevents lubricating oil from scattering toward the ventilation hole 9 due to the rotational drive of the chain 6. A baffle plate 13 is integrally extended to prevent scattered lubricating oil from directly adhering to the vent hole 9.

As is clear from FIG. 3, which shows the section II-m in FIG. It has a shape with a frontage.

Referring again to FIG. 2, another casing 10 is attached to the outside of the ventilation hole 9, and the air chamber 16 and the oil chamber 17 are separated and communicated vertically by the interposition of the partition wall 15. A downwardly open U-shaped air pipe 12 is connected to the air chamber 16 of the lower side to communicate with the atmosphere, and the lower air chamber 17 is connected to the casing 2 through an oil drain hole 18 provided in the casing end surface 8. A cover 19 is attached to the inside of this oil handling hole 18 to prevent lubricating oil from entering.

Next, to explain the operation of the above embodiment, in the shift state of the four-wheel drive, the lubricating oil scraped up by the rotational drive of the chain 6 flows onto the inner circumferential surface of the casing 2 as shown by the arrow 14 in FIG. However, since the baffle plate 13 extends in a direction that covers the vent hole 9 for the air chamber 16 of the air breather and prevents the lubricating oil from scattering, the vent hole 9 The lubricating oil that scatters near the baffle plate 1q hits the lower side of the baffle plate 13 and is prevented from entering the ventilation hole 9, and the baffle plate 13 has a sufficient length to prevent the lubricating oil from entering. J
Therefore, it is possible to almost eliminate lubricating oil from entering the air chamber 16 through the ventilation hole 9.

In addition, the lubricating oil that has passed along the inner wall of the casing 2 is
Even if the oil flows into the air chamber 16 side, there is an oil chamber 17 partitioned off by a partition wall 15 below the air chamber 16.
, all the lubricating oil that flows in from the vent hole 9 accumulates in the lower oil chamber 17 , and even if the lubricating oil accumulates in the oil chamber 17 , the air pipe 12 It is possible to reliably prevent lubricant oil from adhering to the air chamber 16 to which the air chamber 16 is connected. Furthermore, since an oil handling hole 18 is formed at the bottom of the oil chamber 17, the lubricating oil accumulated in the oil chamber 17 is also returned into the casing 2 through the oil handling hole 18, and the lubrication from the air pipe 12 is Oil leakage can be reliably prevented.

In the above embodiment, a cover 19 provided as a separate part is fixed inside with screws or the like in order to prevent lubricating oil from flowing into the oil drain hole 18. casing 2
It may be formed integrally with. Also, oil chamber 1
An oil drain hole may be formed to supply the lubricating oil accumulated in the bearing 7 to the bearing 7 portion. Furthermore, although the above-described embodiments have been exemplified by an auxiliary transmission exclusively for four-wheel drive, the present invention is not limited thereto, and can be applied as is to an air breather used for any suitable transmission.

(Effects of the Invention) As described above, according to the present invention, in an air breather for a transmission that communicates the inside of the casing with the atmosphere, a ventilation hole is formed in the end face of the casing, and lubricating oil is directed toward the ventilation hole by gear rotation, etc. The baffle plate extends inward from the end face of the casing to cover the scattering direction, forming an air chamber outside the vent hole, and an air pipe communicating with the atmosphere is connected to this air chamber, so that the air outside the casing is It is possible to prevent lubricating oil from entering into the air vent communicating with the air chamber by interposing the buffer plate, thereby suppressing the lubricating oil from flowing into the air chamber. In addition, if the air chamber is formed by separating the air chamber and oil chamber, which are communicated vertically through a partition wall, even if lubricating oil flows into the air chamber, it will lubricate the oil chamber formed below through the partition wall. By collecting oil, lubricating oil is completely removed from the air chamber connected to the air pipe,
The interior of the casing can be made conductive to the atmosphere while reliably preventing leakage of lubricating oil from the air pipe.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an example of a conventional air breather structure for a sub-transmission for a four-wheel drive vehicle, FIG. 2 is a cross-sectional explanatory diagram showing an embodiment of the present invention, and FIG. ■-■ It is a sectional view. 2.2-. 10: Casing 3 Ni drive shaft 5: Sprocket 6: Chain 7: Bearing 8: Casing end face 9: Ventilation hole 12: Air pipe 13: Buffel plate 15: Partition wall 16: Air chamber 17: Oil chamber 18; Oil removal patent application Person: Fuji Iron Works Co., Ltd. Susumu Takeuchi, Patent Attorney, Nissan Motor Co., Ltd.

Claims (2)

[Claims] (1) In an air breather for a transmission that conducts the inside of the casing to the atmosphere, a ventilation hole is formed on the end surface of the casing, and a buffel plate is installed on the end surface of the casing to cover the direction in which lubricating oil is scattered toward the ventilation hole due to gear rotation, etc. An air breather for a transmission, characterized in that an air chamber is formed on the outside of the ventilation hole, and an air pipe that communicates with the atmosphere is connected to the air chamber. (2) The air breather for a transmission according to claim 1, wherein the air chamber is a separated chamber that is vertically communicated with each other through a partition wall.