JPS6112448Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a breather device for a power transmission system, and more specifically, to a breather device for a power transmission system. This invention relates to a breather device that prevents an abnormal increase in the internal pressure by communicating the inside and outside of the case when the internal pressure increases due to the above.

[Conventional technology]

In automobile transmissions or axle pipes, internal pressure increases due to the rotation of gears and shaft members housed inside the case, and a breather device is used to prevent lubricating oil from leaking from the oil seal due to this increase in internal pressure. is provided in the case.

For example, as shown in FIG. 4, a conventional breather device includes a breather tube 2 embedded in a case 1, a cap 5 that covers the upper end of the breather tube 2, and a cap 5 formed on the upper end of the breather tube 2. The compression spring 3 is disposed between the flange 2f and a claw 5f formed at the lower end of the cap 5, and biases the cap 5 in a direction to close the upper opening of the breather tube 2. . Under normal conditions, the upper opening of the breather tube 2 is closed by the cap 5 by the spring force of the compression spring 3, and when the internal pressure of the case increases, the cap 5 is pushed up against the spring force of the compression spring 3. , the inside and outside of the case 1 are communicated with each other to prevent an abnormal increase in internal pressure.

[Problem that the invention attempts to solve]

However, in the breather device with the conventional configuration described above, the compression spring 3 is disposed outside the breather tube 2 and is always in contact with the outside air. There was a problem in that the compression spring 3 was easily rusted due to the presence of the spring 3, which was difficult to discharge, and the rusting of the compression spring 3 led to malfunction of the breather device.

Therefore, an object of the present invention is to prevent the compression spring that biases the cap in the closing direction from rusting, thereby maintaining good breather function over a long period of time.

[Means for solving problems]

Therefore, the present invention employs the following configuration as a means for solving the above-mentioned problems.

That is, in the present invention, a compression spring that biases the cap in the direction of closing the upper opening of the breather tube is disposed inside the breather tube, and the compression spring is configured so that it does not always come into contact with the outside air when the cap is in the closed state. Features.

Specifically, using FIG. 1 as an example,
An end wall 2b having a small-diameter opening 2a is formed at the upper end of a breather tube 2 installed in a case 1 of a power transmission system.

On the other hand, the cap 5 that covers the upper end of the breather tube 2 includes a shaft 4a that passes through the small diameter opening 2a and extends inside the breather tube 2, and a flange-like locking portion 4b located at the lower end of the shaft 4a.
A spring receiver 4 consisting of the following is integrally provided.

Furthermore, a small diameter opening 2 is provided between the locking portion 4b of the spring receiver 4 and the end wall 2b of the breather tube 2.
A compression spring 3 is provided that biases the cap 5 in the direction of closing a. Due to the arrangement structure of the compression spring 3, when the cap is closed, the compression spring 3
is constructed so that it does not come into contact with the outside air.

[Effect]

According to the main stage described above, under normal conditions, the cap 5 of the breather device closes the small diameter opening 2a of the breather tube 2 by the spring force of the compression spring 3, and the inside and outside of the case 1 are shut off. When the internal pressure of the case 1 increases, the cap 5 is pushed up against the spring force of the compression spring 3, thereby communicating the inside and outside of the case 1 to prevent an abnormal increase in the internal pressure.

The compression spring 3 is disposed inside the breather tube 2 and is normally isolated from the outside air. Moreover, as the gears and shaft members housed inside the case 1 rotate, a portion of the lubricating oil inside the case 1 becomes droplets and reaches the inside of the breather tube 2, and is supplied to the compression spring 3.

Further, as in the conventional case, a compression spring 3 is provided between the outer circumferential surface of the breather tube 2 and the inner circumferential surface of the cap 5.
Since there is no water, the muddy water that enters is immediately drained away.

Therefore, the compression spring 3 is prevented from rusting.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

1 and 2 are longitudinal sectional views showing a breather device for a power transmission system according to an embodiment of the present invention in different operating states.

In the figure, 1 is a case such as a transmission or a differential gear or an axle tube containing an axle, and the base of a breather tube 2 is implanted in a hole formed in the case 1. At the upper end of the breather tube 2, an end wall 2b having a small diameter opening 2a is provided.
is formed.

On the other hand, a cap 5 covering the upper end of the breather tube 2 has a shaft 4a extending into the interior of the breather tube 2 through the small diameter opening 2a.
A spring receiver 4 consisting of a flange-like locking portion 4b located at the lower end of the shaft 4a is integrally provided on the top inner surface 5a by suitable means such as screwing or welding.

Further, a compression spring 3 is disposed between the flange-like locking portion 4b of the spring receiver 4 and the end wall 2b of the breather tube 2, and urges the cap 5 in a direction to close the small diameter opening 2a. .

The seal between the breather tube 2 and the cap 5 is made between the top inner surface 5a of the cap 5 and the periphery of the small diameter opening 2a formed at the upper end of the breather tube 2, that is, the upper surface of the end wall 2b,
Particularly in this embodiment, the sealing material 6 is disposed on the upper surface side of the end wall of the breather tube 2 to improve sealing performance.

The outer circumferential wall 5b of the cap 5 has an inner diameter slightly larger than the outer diameter of the breather tube 2, and its lower end surface is extended downward to a position close to the outer surface of the case 1. A bottleneck 7 having a slight gap is formed between the outer peripheral surface and the outer surface of the case 1. The presence of this bottleneck 7 helps prevent muddy water from entering the interior of the breather tube.

Further, the flange-like locking portion 4b of the spring receiver 4
has an outer diameter slightly smaller than the inner diameter of the breather tube 2, and receives most of the lubricating oil splashed from inside the case 1.
It is adapted to be turned over and returned into the case 1 by a concave portion 4c formed on its lower surface.

In the power transmission system breather device configured as described above, the internal pressure of case 1 is
Under normal conditions, the sum of the dead weight of the breather tube 2 and the spring force of the compression spring 3, which is smaller than the closing force of the cap 5, the small diameter opening 2a of the breather tube 2 is closed by the cap 5, as shown in FIG. The inside and outside of case 1 are in a state of being cut off. In this state, a part of the lubricating oil splashed from inside the case 1 is spread between the flange-like locking part 4b of the spring receiver 4 and the inner circumferential surface of the breather tube 2, as shown by the arrow (dashed line). is supplied to the upper compression spring 3 through the gap. This lubricating oil serves to prevent the compression spring 3 from rusting. In addition, most of the lubricating oil other than the amount required for rust prevention is received by the flange-like locking part 4b of the spring receiver 4, as shown by the arrow (solid line), and by the concave part formed on the lower surface of the flange-like locking part 4b. 4c and returned into the case 1. Therefore, the lubricating oil splashed from inside the case 1 is prevented from directly reaching the sealing surface between the breather tube 2 and the cap 5, and no lubricating oil leaks out of the breather tube.

Further, the bottleneck 7 prevents muddy water from entering the interior of the breather chamber 2, and even if muddy water enters the bottleneck 7, the breather chamber 2
Between the outer peripheral surface of the cap 5 and the outer peripheral wall 5b of the cap 5,
Since there is no compression spring 3 as in the conventional case, the muddy water that has entered is immediately discharged. Therefore, muddy water accumulated on the inner circumference of the cap 5 does not adhere to the sealing surface between the breather tube 2 and the cap 5 and deteriorate the breather function, unlike in the conventional case.

Then, as the gears and shaft members rotate, case 1
When the internal pressure of the cap 5 overcomes the closing force of the cap 5, the second
As shown in the figure, the cap 5 is pushed up against the spring force of the compression spring 3. As a result, a ventilation path is formed within the breather device, and the air inside the case 1 is discharged to the outside as indicated by the arrow (solid line), so that an abnormal increase in the internal pressure of the case 1 is prevented.

In this way, the breather function is achieved when the internal pressure of the case 1 increases, and (a) since the compression spring 3 is disposed inside the breather tube 2, the compression spring 3 is not activated in the normal cap closed state. (b) A portion of the lubricating oil splashed from inside the case 1 into the breather tube 2 is supplied to the compression spring 3; (c) The cap 5, the breather tube 2, and the case 1 form a bottleneck 7 that prevents muddy water from entering the case; There is no need to worry about the spring 3 rusting.

FIG. 3 shows a breather device for a power transmission system according to another embodiment of the present invention.

In FIG. 3, parts corresponding to those in FIG. 1 are designated by the same reference numerals as in FIG. 1.

In this embodiment, a seal portion S is formed between the lower end of the outer circumferential wall 5b of the cap 5 and a seal member 8 provided on the outside of the breather tube 2 or on the case 1 side.

In this embodiment, since the seal portion S is provided at the lower end of the cap outer peripheral wall 5b, the inside of the cap outer peripheral wall 5b is always isolated from the outside air under normal conditions.
It is also possible to prevent muddy water from adhering to the breather cube 2. Further, there is no need to form a bottleneck inside the cap 5 as in the above-described embodiments.

Further, since the seal portion S is formed with a widening slope, even if muddy water should enter between the cap 5 and the breather tube 2, the muddy water can be smoothly discharged.

[Effect of idea]

As described above, according to the present invention, it is possible to prevent rusting of the compression spring, which is a cause of malfunction of the breather device, and in turn, it is possible to maintain good breather function over a long period of time, and to extend the life of the breather device. It is possible to extend the lifespan.

Furthermore, compared to conventional devices, leakage of lubricating oil from the breather device can be prevented.

[Brief explanation of the drawing]

Figures 1 and 2 show a breather device for a power transmission system according to an embodiment of the present invention in different operating states. Vertical cross-sectional view when internal pressure increases, 3rd
The figure is a longitudinal sectional view corresponding to FIG. 1 showing a breather device for a power transmission system according to another embodiment of the present invention, and FIG. 4 is a longitudinal sectional view corresponding to FIG. 1 showing a conventional breather device for a power transmission system. FIG. Explanation of symbols, 1... Case, 2... Breather tube, 2a... Small diameter opening, 2b... Breather tube end wall, 3... Compression spring, 4... Spring receiver, 4a... Shaft, 4b... Flange-shaped locking part, 5
...Cap, 5a...Cap top inner surface, 5b
... Cap outer peripheral wall, 6 ... Seal material, 7 ... Bottle, 8 ... Seal member.

Claims (1)

[Scope of utility model registration request] An end wall having a small-diameter opening is formed at the upper end of the breather tube embedded in the case of the power transmission system, and an end wall having a small-diameter opening is formed in the cap covering the upper end of the breather tube, and an end wall is formed inside the breather tube by passing the small-diameter opening into the cap that covers the upper end of the breather tube. A spring bearing consisting of an extending shaft and a flange-shaped locking part located at the lower end of the shaft is integrally provided, and the small diameter opening is further provided between the locking part of the spring bearing and the end wall of the breather tube. A breather device for a power transmission system, characterized in that a compression spring is disposed to bias the cap in a closing direction so that the compression spring does not come into contact with outside air when the cap is closed.