JP2002130435A - Breather structure of transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a breather structure of a transmission allowing little infiltration of water without using an exclusive part as a breather. SOLUTION: A shift control shaft 3 and a select control shaft 4 are arranged by penetrating through a control box 2 arranged above the transmission 1, and an air breather passage 7 for allowing air flow on the inside and outside of the transmission 1 is arranged in the shaft direction of the shift control shaft 3 or the select control shaft 4 in its either penetrating part 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a breather structure for a transmission for circulating air inside and outside of a transmission and adjusting the internal pressure thereof to prevent leakage of lubricating oil.

[0002]

2. Description of the Related Art A breather used in a vehicular transmission includes an oil seal provided on a rotating shaft or the like when the internal temperature of the transmission increases due to the operation of the engine and the internal pressure of the transmission increases. It has a function to discharge air in the transmission to the outside so that lubricating oil does not leak from the transmission. Conversely, when the internal temperature of the transmission decreases due to the stop of the engine or cleaning, etc., and the internal pressure of the transmission decreases, external transmission such as water is prevented from being sucked into the transmission by an oil seal or the like. It also has the function of taking in air and reducing the pressure difference between inside and outside.

[0003] The breather of the conventional transmission is provided on the inner wall of the transmission at an upper portion where no lubricating oil is applied.

FIGS. 7 to 9 are sectional views showing the structure of a conventional breather.

[0005] A breather 51 shown in FIG.
And a hose 54 is attached to the nozzle 53. The end of the hose 54 is extended to a portion of the vehicle that is not affected by water or the like. Breather 5 shown in FIG.
5, a top cover 57 having a long portion covering the nozzle 56 is attached to the nozzle 56, and an air breather passage 63 is provided.
With a maze structure to make it difficult for water to enter.

The breather 58 shown in FIG.
A top cover 62 provided with a spring 60 and a valve 61 is attached to 9 and the opening and closing of the valve 61 allows air to flow inside and outside the transmission.

[0007]

However, in the conventional breathers 51, 55, and 58 described above, it is necessary to provide a dedicated part for the purpose of the breather, and there is a problem that manufacturing cost and labor are required. there were.

The breather 5 shown in FIGS.
In 5,58, the penetration resistance of water etc. is not so good,
In particular, during high-pressure car washing, etc., water was sometimes introduced. Therefore, the present invention has been devised to solve the above problem, and an object of the present invention is to provide a breather structure of a transmission in which water or the like is unlikely to enter without using a dedicated part as a breather. .

[0009]

In order to solve the above-mentioned problems,
The present invention provides a shift control shaft and a select control shaft that penetrate a control box provided on an upper portion of a transmission, and an air breather passage for performing air circulation inside and outside the transmission is provided in any of the penetrating portions. It is provided along the axial direction of the shift control shaft or the select control shaft.

[0010] According to the above configuration, the air breather passage is provided in the penetrating portion of the shift control shaft or the select control shaft of the control box originally provided in the transmission, so that the breather structure can be formed only by simple processing. Since it can be formed, there is no need to provide a separate dedicated part as in the related art, and the manufacturing cost and labor can be reduced.

Preferably, an oil seal is provided between the shift control shaft or the select control shaft and the control box, and the air breather passage is formed so as to pass radially outside the oil seal.

Also, in the middle of the air breather passage,
In addition, an oil chamber surrounding the shift control shaft or the select control shaft is provided inside the control box of the oil seal, and the shift control shaft or the select control shaft located inside the control box of the oil chamber is penetrated. It is preferable that the portion is provided with a lubricating oil return passage for returning the oil accumulated in the oil chamber into the transmission.

[0013] Further, a projecting portion of the shift control shaft or the select control shaft projecting outward from the control box is covered with boots,
It is preferable that the inside of the boot be an air chamber and the boot be provided with a breather hole.

Preferably, the boot is formed of an elastic body, and the breather hole is formed of a pipe integrally formed with the boot.

It is preferable that the outer end of the through portion where the air breather passage is opened protrudes into the air chamber from the inner wall surface of the air chamber.

Further, at least one of the shift control shaft and the select control shaft is arranged in a horizontal direction, and the air breather passage is provided above a through portion of one of the shafts arranged in the horizontal direction. Preferably, the lubricating oil return passage is provided in a lower portion of the portion, and the breather hole is formed in a lower portion of the boot.

[0017]

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

FIG. 1 is a sectional view showing a preferred embodiment of a breather structure of a transmission according to the present invention, FIG. 2 is a sectional view taken along line AA of FIG. 1, and FIG. 3 is a sectional view taken along line BB of FIG. FIG. 4 is a schematic view showing the entire transmission.

First, the configuration of the breather structure of the transmission according to the present embodiment will be described.

As shown in FIG.
A control box 2 is provided above a transmission case 10 constituting an outer shell of the control box 2. The internal space of the transmission 1 and the control box 2 communicate with each other. The transmission case 10 and the control box 2 are formed by casting.

The control box 2 is provided with a select control shaft 4 for selecting a fork for moving the synchro sleeve, and a shift control shaft 3 for moving the selected fork in the axial direction.

The control box 2 has through holes 33 through which the shafts 3 and 4 are inserted. The select control shaft 4 is arranged to extend in the vertical direction, and the shift control shaft 3 is arranged to extend in the horizontal direction, and is inserted and supported in each through hole 33 of the control box 2.

As shown in FIGS. 1 to 3, a through hole 33 through which the shift control shaft 3 is inserted is provided with a shaft support portion 34 arranged in order from the inside to the outside of the control box 2 and an oil support. Chamber formation part 3
5 and an oil seal mounting portion 36.

The shaft support 34 has an inner diameter equal to the outer diameter of the shift control shaft 3 so that the shift control shaft 3 slides and rotates.

The oil chamber forming portion 35 is formed so as to have a diameter larger than the inner diameter of the shaft support portion 34, and forms the oil chamber 12 surrounding the shift control shaft 3.

The oil seal mounting portion 36 is formed to have a diameter larger than the inner diameter of the oil chamber forming portion 35, and the ring-shaped oil seal 9 is fitted and mounted on the inner peripheral surface thereof.

By the way, the present invention utilizes an air breather passage for circulating air inside and outside of a transmission by using a through portion where a shift control shaft or a select control shaft is simply inserted and supported in a control box. Is provided.

Therefore, in the present embodiment, the air breather passage 7 is provided above the shift control shaft 3 and the penetrating portion 5 of the control box 2 arranged in the horizontal direction.
Are provided along the axial direction of the shift control shaft 3.

A groove 8a for defining the air breather passage 7 is formed on the upper end surface of the inner peripheral wall of the through hole 33 (see FIG. 2). The groove 8a is recessed upward and formed along the axial direction of the shaft support portion 34.

On the upper end surface of the inner peripheral wall of the oil seal mounting portion 36 (radially outward of the oil seal 9), a groove 8b defining the air breather passage 7 is opened to the inner peripheral surface of the oil chamber forming portion 35. (See FIG. 3).

The air breather passage 7 includes a space defined by the groove 8a and the shift control shaft 3, an upper space of the oil chamber 12, and a space defined by the groove 8b and the oil seal 9.

The shift control shaft 3 has an outer end whose diameter is enlarged. When the shift control shaft 3 is inserted into the through hole 33, the enlarged diameter portion 6 comes into sliding contact with the inner peripheral surface of the oil seal 9. . The positions of the inner end of the enlarged diameter portion 6 and the inner end of the oil seal 9 substantially match.

The penetrating portion 5 (shaft support portion 34) located inside the control box of the oil chamber 12
A lubricating oil return passage 14 for returning the oil accumulated in the oil chamber 12 to the inside of the transmission 1 is provided at a lower portion of the transmission chamber 1.

The lubricating oil return passage 14 is formed by forming a groove 15 in the lower end surface of the inner peripheral wall of the shaft support portion 34 of the through hole 33 (see FIG. 2). The bottom position of the lubricating oil return passage 14 is higher than the bottom position of the oil chamber 12.
When the oil inside the reservoir accumulates above the bottom surface of the lubricating oil return passage 14, the oil is returned.

A boot 17 is provided on the projecting portion 16 of the shift control shaft 3 projecting outward from the control box 2 through the through hole 33. The internal space defined by the boot 17 forms an air chamber 25. The boot 17 serves to prevent water from entering the air breather passage 7,
It has a function of preventing dust and dirt from adhering around the outside opening of the air breather passage 7.

The boot 17 is formed of an elastic material such as rubber. A ridge 22 is formed on the inner peripheral surface of the base end portion 18 of the boot 17 on the control box 2 side.
Outer peripheral surface 1 of control box 2 constituting penetrating portion 5
9 has a locking groove 21 formed along its circumferential direction. The ridge 22 is locked in the locking groove 21 and the boot 1
7 is fixed to the control box 2.

In this embodiment, a hole 24 through which the shift control shaft 3 penetrates is formed at the tip 23 of the boot 17, and a part of the projecting portion 16 of the shift control shaft 3 covers the boot 17. The tip of the protruding portion 16 is exposed to the outside.
The tip of the protruding portion 16 has a shift control lever 2
0 is provided.

The boot 17 is provided with a breather hole 26 for breathing the air in the air chamber 25 to the outside. The breather hole 26 is constituted by a pipe 27 having a predetermined length integrally formed with the boot 17.

Next, the operation of the breather structure of the transmission 1 having the above configuration will be described.

The temperature inside the transmission 1 rises due to the operation of the engine, and the transmission 1
When the internal pressure of the transmission 1
The air in the control box 2 passes through an air breather passage 7 provided in the penetrating portion 5 and reaches an air chamber 25 in the boot 17 as shown by an arrow in FIG. Is done.

At this time, since the air flow hits the oil seal 9 in the oil chamber 12 and is bent upward, the transmission 1 and the control box 2
Even if the lubricating oil is mixed into the air from the inside, the lubricating oil is separated by hitting the side surface of the oil seal 9 in the oil chamber 12 and falls downward, and returns to the transmission 1 through the lubricating oil return passage 14. It is. Therefore, before the lubricating oil accumulates to the height of the air breather passage 7,
Since it returns into the transmission 1 through the lubricating oil return passage 14, it does not leak outside.

Further, as described above, since the air in the transmission 1 is released to the outside, the internal pressure of the transmission 1 is appropriately maintained without increasing, and thus the transmission 1 is provided on a rotating shaft or the like. Leakage of lubricating oil from an oil seal or the like can be prevented.

On the other hand, when the internal pressure of the transmission 1 decreases due to a temperature decrease in the transmission 1 due to a stop of the engine or washing, etc., as shown by an arrow in FIG. The air is sucked into the air chamber 25 and reaches the oil chamber 12 through the upper portion of the air breather passage 7 in the radial outside of the oil seal 9. Then, the air flows into the transmission 1 through the portion of the air breather passage 7 inside the oil chamber 12 (the shaft support portion 34) and the lubricating oil return passage 14.

As a result, the internal pressure of the transmission 1 is properly maintained without lowering, so that it is possible to prevent foreign substances such as external water from being sucked from the oil seal or the like. In addition, regarding the penetration resistance of water and the like when suctioning air,
Since the breather hole 26 is formed downward at the lower end of the boot 17 and is formed by the pipe 27, intrusion of water or the like into the air chamber 25 is very unlikely to occur. Further, since the opening of the air breather passage 7 is formed above the inside of the air chamber 25, even if water or the like enters the air chamber 25, the water flows along the inner wall surface of the air chamber 25. Thus, the air does not flow downward from the breather hole 26 and flow into the air breather passage 7.

Further, since the boot 17 is formed of an elastic body and the breather hole 26 is formed of a pipe 27 formed integrally with the boot 17, water is supplied depending on the length of the pipe 27 during high pressure washing or the like. Is air chamber 2
5 hardly penetrates into the inside. Also, the pressure of the water injected from the washing machine causes the pipe-shaped breather hole 26
Is bent in the direction of the water flow, and the channel inside thereof is closed, so that water does not enter.

In the above-described embodiment, the example in which the air breather passage 7 is formed in the through portion 5 of the shift control shaft 3 arranged in the horizontal direction has been described. An air breather passage may be provided in the through portion.

However, if an air breather passage is provided in the vertically penetrating portion of the select control shaft 4, the air breather passage will also be vertical, and water and the like will easily penetrate. It is preferable to provide an air breather passage 7 in the through portion 5 of the shift control shaft 3.

Further, in this embodiment, the shift control shaft 3 is arranged in the horizontal direction and the select control shaft 4 is arranged in the vertical direction. Is of course applicable.

According to the above configuration, the air breather passage 7 is provided in the through-hole 5 of the shift control shaft 3 or the select control shaft 4 of the control box 2 provided in the existing transmission 1, so that only simple processing is required. Can form a breather structure.

Specifically, in the present embodiment, the control box 2 is formed in the through hole 33 of the mold for casting and molding.
It can be dealt with only by a simple change such as providing a projection for forming the grooves 8a, 8b, 15 and a breather structure can be formed at very low cost. Further, a method of machining the grooves 8a, 8b, 15 without changing the mold is possible. As described above, there is no need to provide a separate dedicated component as in the related art, and the manufacturing cost and labor can be reduced.

As another embodiment, FIG.
As shown by a dashed line, the outer end 28 of the through portion 5 where the air breather passage 7 is opened is connected to the air chamber 2.
It is preferable that the boot 17 be configured so as to protrude inward of the air chamber 25 from the inner wall surface 29 of the boot 17 that defines the boot 5.

According to this, even if water intrudes into the upper part of the boot 17, the water flows along the inner wall surface 29 of the boot 17, and flows along the outer peripheral surface 31 of the projecting penetrating part 5. Therefore, water does not flow into the opening of the air breather passage 7 and water does not enter the air breather passage 7. Therefore, intrusion of water or the like into the transmission 1 can be prevented.

[0053]

In summary, according to the present invention, an air breather passage is provided in a penetrating portion of a shift control shaft or a select control shaft of a control box. As a result, it is possible to provide a transmission breather structure without using special parts. In addition, the air breather passage is provided in the through portion of the shift control shaft or select control shaft arranged in the horizontal direction, and the boot is formed of an elastic body, and the breather hole is formed in a pipe shape at the lower part of the boot. Etc. can be made harder to penetrate.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a preferred embodiment of a breather structure of a transmission according to the present invention.

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

FIG. 3 is a sectional view taken along line BB of FIG. 1;

FIG. 4 is a schematic diagram showing the entire transmission.

FIG. 5 is a cross-sectional view showing a flow when air is released from a breather structure of the transmission according to the present invention.

FIG. 6 is a cross-sectional view showing a flow at the time of sucking air in a breather structure of the transmission according to the present invention.

FIG. 7 is a cross-sectional view showing a conventional breather structure.

FIG. 8 is a sectional view showing another conventional breather structure.

FIG. 9 is a sectional view showing still another conventional breather structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transmission 2 Control box 3 Shift control shaft 4 Select control shaft 5 Penetration part 7 Air breather passage 9 Oil seal 12 Oil chamber 14 Lubricating oil return passage 17 Boot 25 Air chamber 26 Breather hole 28 Outer side end (of penetration part) 29 Inner wall surface (of air chamber)

Claims (7)

[Claims] A shift control shaft and a select control shaft are provided through a control box provided on an upper portion of a transmission, and an air breather passage for performing air circulation inside and outside the transmission is provided in one of the through portions. A breather structure for a transmission, which is provided along the axial direction of the shift control shaft or the select control shaft. 2. An oil seal is provided between the shift control shaft or the select control shaft and the control box, and the air breather passage is formed so as to pass radially outside the oil seal. Transmission breather structure. 3. An oil chamber surrounding the shift control shaft or the select control shaft is provided in the middle of the air breather passage and inside the control box of the oil seal. 3. The breather structure of a transmission according to claim 2, wherein a lubricating oil return passage for returning oil accumulated in the oil chamber to the inside of the transmission is provided in a penetrating portion of the shift control shaft or the select control shaft located in the transmission control shaft. 4. A shift control shaft or a select control shaft, wherein a protruding portion of the shift control shaft or the select control shaft protruding outside the control box is covered with a boot, an inside of the boot is used as an air chamber, and a breather hole is provided in the boot. 4. The breather structure for a transmission according to any one of 1 to 3. 5. The breather structure of a transmission according to claim 4, wherein said boot is formed of an elastic body, and said breather hole is formed of a pipe integrally formed with said boot. 6. The air chamber according to claim 4, wherein an outer end of the through-hole through which the air breather passage is opened projects inward of the air chamber from an inner wall surface of the air chamber. Transmission breather structure. 7. At least one of the shift control shaft and the select control shaft is arranged in a horizontal direction, and the air breather passage is provided above a through portion of one of the shafts arranged in the horizontal direction. 7. The breather structure for a transmission according to claim 5, wherein said lubricating oil return passage is provided at a lower portion of a through portion, and said breather hole is formed at a lower portion of said boot.