JPH10103453A - Air breather structure of automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a normal letting air in/out through a ventilation structure from being hindered even when unfavorable conditions such as a rapid rise in temperature, excessive filling of oil and forgetting mixing defoaming agent comes one after another. SOLUTION: A second through hole 23 is formed on the upper part of a bulkhead part 13 partitioning space on the side of a transmission case 11 and space on the side of an extension case 12. Because the mutual upper space recovers pressure balance through the second through hole 23 even in a state that oil foams, a fuel-level height rises and a first through hole 14 sinks under oil, a situation that a pressure rise on the side of the transmission case 11 pushes out oil to the side of the extension case 12 through the first through hole 14, the oil surface of the extension case 12 is raised and the oil surface comes to the height of a groove structure 25 is evaded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air breather structure for an automatic transmission that cancels a difference in pressure between inside and outside by making a housing space communicate with outside air.

[0002]

2. Description of the Related Art In a housing of an automatic transmission, oil for operating a transmission mechanism of the automatic transmission hydraulically to lubricate and cool the transmission mechanism is stored. The housing of the automatic transmission is provided with an air breather structure for communicating the housing space with the outside air. The ingress and egress of air through the air breather structure offset the temperature change of the automatic transmission and the pressure difference between the inside and outside of the housing due to the ingress and egress of oil.

An example of an air breather structure of an automatic transmission is disclosed in Japanese Utility Model Laid-Open Publication No. Sho 59-118847. Here, the casing of the automatic transmission is divided into a first casing part and a second casing part by a partition part having a communication hole formed in the center side.
A rotating element that is axially linked to the speed change mechanism stored in the housing is stored in the second housing. The ventilation structure that communicates the space inside the housing with the outside air communicates not with the first housing but with the second housing. The ventilation structure includes a small space formed by covering a hollow space formed in the partition with a lid member. The small space communicates with the second housing on the downstream side in the rotation direction of the rotating element.

[0004]

The temperature of the oil contained in the automatic transmission rises to a temperature exceeding 130 ° C. during operation. On the other hand, at the time of startup in the extremely cold season, the oil may be exposed to a temperature of 0 ° C. or lower. Such a wide temperature change causes a change in the volume of the oil due to thermal expansion and also greatly changes the properties of the oil. Therefore, the air breather structure of the automatic transmission needs to discharge only the air from which the oil has been separated when the air in the housing is discharged to the outside, even if such a change in the volume or properties of the oil occurs. .

[0005] Further, when changing oil in an automatic transmission, the amount of oil to be filled is strictly measured. However, even if an overfill is performed by mistake, the air breather structure of the automatic transmission needs to discharge only the air from which the oil has been separated. In addition, when the temperature of the oil rises during operation, the oil easily foams. Therefore, an antifoaming agent is mixed with the oil to suppress the apparent rise in the oil level due to the foaming and the air suction of the oil pump. However, even if the user mistakenly forgets to mix the defoamer, the air breather structure of the automatic transmission needs to discharge only the air separated from the oil.

Further, as shown in Japanese Utility Model Laid-Open Publication No. Sho 59-118847, when a rotating element interlocked with a transmission mechanism of an automatic transmission is stored in a second housing portion, excessive rotation or foaming may occur. When the oil level of the second housing part rises and comes into contact with the lower part of the rotating element, the oil is scraped up by the rotation of the rotating element, and the oil enters the ventilation structure provided at the upper part of the second housing part. The normal air discharge to the outside may be hindered.

The present invention can discharge only the air from which oil has been separated, even under the adverse conditions of a rapid temperature rise, excessive filling of oil, and forgetting to mix the defoamer.
It is an object of the present invention to provide an oil breather structure of an automatic transmission in which normal ventilation of air by a ventilation structure is not hindered even when a rotating element of a second housing part is immersed in oil and rotates at high speed.

[0008]

According to a first aspect of the present invention, there is provided a first housing portion for storing a transmission mechanism of an automatic transmission, and a first housing portion provided at a lower portion.
An automatic transmission having a second housing part separated from the first housing part by a partition part provided with a communication hole, and a ventilation structure for communicating the second housing part with the outside air to offset a pressure difference between the inside and the outside. In the above air breather structure, a second communication hole is provided in the partition wall portion so as to allow the upper space of the first housing portion and the upper space of the second housing portion to communicate with each other to balance the mutual pressure.

According to a second aspect of the present invention, in the configuration of the first aspect, the partition portion is formed integrally with one of the first housing portion and the second housing portion.

According to a third aspect of the present invention, there is provided a first housing for storing a transmission mechanism of an automatic transmission, a second housing for storing a rotating element which is axially interlocked with the transmission mechanism, and a first housing. A first communication hole that allows oil to move between the first housing and the second housing, and a partition that separates the first housing from the second housing; In an air breather structure of an automatic transmission having a ventilation structure for canceling a pressure difference between inside and outside by communicating with each other, an upper space of the first housing portion and an upper space of the second housing portion are communicated to balance each other's pressure. A second communication hole to be provided in the partition portion, and a small space communicating with the second housing portion through two or more communication paths arranged at a distance in a rotation direction of the rotating element is provided in the ventilation structure. It is.

According to a fourth aspect of the present invention, the small space in the third aspect has a constricted structure in which a cross-sectional area is reduced in the middle of two or more spaces communicating with the respective communication paths.

According to a fifth aspect of the present invention, there is provided a first housing for storing a transmission mechanism of an automatic transmission, a second housing for storing a rotating element which is axially interlocked with the transmission mechanism, and a first housing. A first communication hole that allows oil to move between the first housing and the second housing, and a partition that separates the first housing from the second housing; In an air breather structure of an automatic transmission having a ventilation structure for canceling a pressure difference between inside and outside by communicating with each other, an upper space of the first housing portion and an upper space of the second housing portion are communicated to balance each other's pressure. A second communication hole to be provided is provided in the partition, and a small space communicating with the second housing through a communication path extending upward from the center of the rotating element in a radial direction is provided in the ventilation structure.

[0013] The invention of claim 6 is the invention of claim 3, 4, or 5.
The second communication hole in the above configuration is arranged so as to be displaced from the position immediately above the communication path in the rotation direction of the rotary element.

According to a seventh aspect of the present invention, there is provided the first aspect of the invention.
In the configuration of 4, 5, or 6, a first hollow space having an opening area larger than that of the second communication hole is formed in a portion of the inner wall of the second housing portion facing the second communication hole.

According to the invention of claim 8, the second recessed space formed in the partition which partitions the first casing and the second casing of the automatic transmission, and the second recessed space fixed to the partition are formed. Wrap,
In an air breather structure of an automatic transmission having a lid member forming a small space communicating with both the outside of the automatic transmission and the second housing portion, a sheet-like sealing member for sealing an edge of the second hollow space is provided. Prior to assembling the lid member, the lid member is attached and fixed to one surface of the lid member.

[0016]

According to the air breather structure of the automatic transmission according to the first aspect, air or oil flows in and out through the second communication hole,
Since the pressure in the upper space of the first housing portion and the pressure in the upper space of the second housing portion are balanced, even if the pressure rise of the first housing portion occurs in a state where the first communication hole is submerged in oil, It is difficult for the oil of one housing part to be pushed out to the second housing part through the first through hole. Therefore, the oil level of the second casing does not rise to the height of the entrance communicating with the ventilation structure, and the possibility that oil enters the ventilation structure is low.

In the air breather structure for an automatic transmission according to the present invention, since the partition is integrated with one of the first housing and the second housing, the first housing and the second housing are combined. Are connected, partitioning of the first housing portion and the second housing portion by the partition wall is achieved.

In the air breather structure for an automatic transmission according to the third aspect, even if the oil of the second casing is scattered,
Since it is rare that the scattered lump of oil blocks two or more communication paths at the same time, the ventilation structure can maintain the communication state of the air to the outside without being hindered by the oil. Also, two or more communication paths are simultaneously blocked by separate oil lumps,
Even when the oil is about to enter the ventilation structure, unlike the case where the communication path is closed due to the rise in the oil level of the second casing, the oil lumps are removed from the communication path in a short time, and the small space is removed. Before the oil is filled, the communication state between the second housing portion and the outside air is restored.

In the air breather structure of the automatic transmission according to the fourth aspect, since the constricted structure bends the flow of the air flowing into the small space, the oil collides with the wall surface of the small space and separates when the air mixed with the oil flows. Is done.

In the air breather structure for an automatic transmission according to the fifth aspect, since communication with the outside is ensured on the center side of the second housing portion through the communication path, the rotating element in contact with the oil rotates at a high speed and the second element rotates. Even in a state where the oil of the two housing parts is scattered and covers the inner peripheral surface of the second housing part by centrifugal force, a high air ratio is secured near the entrance of the communication path, and the oil enters the ventilation structure. Don't worry. In addition, since the communication path is formed in the upward radiation direction, even if the communication path is blocked by an oil mass, the normal housing air communication between the second housing portion and the outside is restored with the rotation of the rotating element. Then, the oil that has lost the backup of the pressure of the second housing part flows down from the communication path to the second housing part due to gravity.

In the air breather structure for an automatic transmission according to the present invention, since the arrangement of the second communication hole is displaced from a position immediately above the communication path, the second housing hole is stopped from the first housing portion through the second communication hole. Even if the oil flows out to the body, the oil does not flow down near the entrance of the communication path. Also,
Since the arrangement of the second communication hole is shifted from the position immediately above the communication path in the rotation direction of the rotary element, the oil flows out from the first housing portion to the second housing portion through the second communication hole while the rotary element is rotating. In this case, the oil that flows out is guided by the rotation of the rotating element, moves away from the entrance of the communication path, and is not guided near the entrance.

In the air breather structure for an automatic transmission according to the present invention, since the first recessed space is formed in a portion facing the second communication hole, the first housing portion is connected to the second housing through the second communication hole. When the oil suddenly flows out to the portion, the oil is temporarily captured in the first hollow space and gradually flows out to the second housing portion. Therefore, in both the stopped state and the rotating state, the change in the state of the oil in the second housing portion is suppressed, and it is possible to prevent the oil from dripping near the entrance of the ventilation structure due to the change in the state of the oil. Further, even when the rotating element in contact with the oil rotates at a high speed and the oil covers the inner peripheral surface of the second housing portion, the edge of the first recessed space forms a shadow, and the outlet of the second through-hole is formed of the oil. To avoid being blocked. Accordingly, the pressure loss and the flow path resistance of the second through-hole are kept low, and the movement of air and oil through the second through-hole becomes smooth.

In the air breather structure for an automatic transmission according to the present invention, sealing of the small space and the corner of the ceiling of the communication path is realized by a sheet-shaped sealing member. The seal member is fixed to one side of the lid member before the assembly, and the mounting of the seal member is completed only by positioning and fixing the lid member at a predetermined position of the partition.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An air breather structure according to an embodiment will be described with reference to FIGS. 1 is a partial cross-sectional view of the automatic transmission, FIG. 2 is a plan view of a connection surface on a transmission case side, FIG. 3 is a cross-sectional view taken along the air breather of FIG.
FIG. 4 is an explanatory view of a connecting surface on the extension case side, and FIG. 5 is an explanatory view of a lid member in a small space. 4A is a plan view, and FIG. 4B is a cross-sectional view taken along line BB. In FIG. 5, (a)
Is a plan view, and (b) is an AA cross-sectional view.

As shown in FIG. 1, an extension case (second casing) 12 is connected to an output side of a transmission case (first casing) 11. The partition 13 integrally formed with the transmission case 11
The housing space of the automatic transmission is partitioned and divided into the transmission case 11 side and the extension case 12 side. The first communication hole 14 formed in the lower part of the partition 13 is
The oil in the transmission case 11 and the extension case 12 can be moved. Oil pan 2 connected to the bottom side of transmission case 11
Reference numeral 4 forms a space for collecting the oil discharged into the transmission case 11 and the extension case 12.

A transmission mechanism 20 including a plurality of sets (not shown) of a planetary gear set, a multi-plate brake, a multi-plate clutch and the like is stored in the transmission case 11. A torque converter case (not shown) containing a torque converter is connected to the transmission case 11 on the side opposite to the extension case 12. Transmission mechanism 20
Is lubricated by oil supplied through an oil passage provided at the center of the output shaft 19.

A parking gear 15 fixed to an output shaft 19 is stored in the extension case 12.
A seal mechanism (not shown) is provided at an end (not shown) of the extension case 12 to seal the outer periphery of the propeller shaft connected to the output shaft 19 to ensure a sealed state of the automatic transmission. The mechanism in the extension case 12 including the parking gear 15 is also lubricated by the oil supplied through the oil passage of the output shaft 19.

A second through hole 23 is formed in the upper part of the partition 13. The second through hole 23 is a round hole extending from the extension case 12 side of the transmission case 11 to the innermost portion 26 of the spline 27, and connects the upper space of the transmission case 11 and the upper space of the extension case 12. Spline 27
The friction plate 28 on the stop side of the multiple disc brake of the transmission mechanism 20 is held so as to be movable in the axial direction.

As shown in FIG. 2, the oil breather 3
0 is disposed at an angular position shifted from the second through hole 23 in the normal rotation direction of the parking gear 15. The opening 21 of the through hole to which the oil breather 30 is attached is
Communicates with the second recessed space 16 provided at the upper part. A path from the oil breather 30 to the groove structure 25 through the opening 21 and the second recessed space 16 forms a ventilation structure. By the air flowing in and out through the ventilation structure, the pressure balance between the housing space of the automatic transmission and the outside is maintained. As shown in FIG. 3, the cover member 17 is attached to the connection surface 32 at the edge of the second recessed space 16 by the screw member 18. As shown in FIG. 5, the cover member 17 has a through hole 36 into which the screw member 18 is inserted. Prior to assembly, the rubber sheet 37 is provided on the side of the fan-shaped iron plate 36 facing the connection surface 32.
Is affixed as a seal member. And the lid member 1
7 forms the ceiling of the groove structure 25 shown in FIG. 2 and forms a through-hole that opens downward toward the central axis side of the extension case 12.

The transmission case 11 shown in FIG.
Is connected to the connecting surface 39 of the extension case 12 shown in FIG. As shown in FIG. 4B, the first hollow space 22 having a larger opening area than the second through hole 23 is provided on the extension case 12 side so as to face the second through hole 23 of the transmission case 11. Is formed. When the transmission case 11 and the extension case 12 are connected,
The first hollow space 22 communicates with the space in the extension case 12 through the narrow portion 38.

Incidentally, the oil level of the automatic transmission is
In a stopped state before starting, the lower portion of the transmission mechanism 11 and the first communication hole 14 occupy the lower portion of the transmission case 11 and the oil pan 24 shown in FIG. Further, an antifoaming agent is mixed in the oil sealed in the automatic transmission, so that even if the oil temperature increases, the foaming property does not increase so much. However, when the high temperature operation is continued for a long time in a state where the antifoaming agent is forgotten to be mixed with the oil and the oil temperature is significantly increased, the oil foams to increase the apparent volume, and the apparent oil in the transmission case 11 is increased. There is a possibility that the surface height is increased to make contact with the transmission mechanism 20. When the oil is agitated by the transmission mechanism 20 rotating at a high speed, a strong foaming state is caused, and the apparent volume and thermal expansion coefficient of the oil are increased. Then, when the oil level further rises and the first through-hole 14 sinks below the oil level, the ingress and egress of air through the first through-hole 14 are prevented. At this time, if the communication between the transmission case 11 side and the extension case 12 side is only the first communication hole, the pressure rise on the transmission case 11 side causes a state in which oil is pushed out to the extension case 12 side through the first through hole 14. As a result, oil containing air bubbles overflows from the transmission case 11 side to the extension case 12 side, and the oil level of the extension case 12 is increased.

If the operation is stopped after the high load operation is continued for a long time in a state where the defoaming agent is forgotten to be mixed into the oil, a large amount of hot oil is returned from a torque converter (not shown), Since the cooling by the oil circulation of the machine is also stopped, adverse conditions are further increased, and the temperature and pressure in the transmission case are temporarily increased as compared with during operation, so that the oil containing air bubbles is transmitted from the transmission case 11 side to the extension case 12.
May be pushed further to the side.

According to the oil breather structure of this embodiment,
Even under such bad conditions, the transmission case 11 and the extension case 1
Since the pressure balance of 2 is ensured, the amount of oil pushed out to the extension case 12 side is suppressed. In addition, due to the following features, a normal air communication state between the extension case 12 and the air breather 30 in the external space is maintained.

That is, the second hollow space 16 and the lid member 1
The small space surrounded by 7 communicates with the space in the extension case 12 through two groove structures 25 arranged at a distance, so that one groove structure 25 is temporarily closed with oil. Also, the communication between the inside of the extension case 12 and the external space by air is ensured through the other groove structure 25. Also, the second hollow space 16 and the lid member 17
Since the small space surrounded by the space forms an oil and air separation space, the air mixed with the oil droplets flowing through the narrow groove structure 25 lowers the flow velocity in the small space to separate the oil droplets. In the small space surrounded by the second recessed space 16 and the lid member 17, the small space is cut off by a rib structure 34 which also serves to reinforce the partition wall 13 and the thickness around the female screw 33 for fixing the screw member 18. Since the constricted structure having a reduced area is formed, the air mixed with the inflowing oil is bent by bending the flow path thereof to collide the oil with the wall surface and is separated. The lower groove structure 25 has a lower height, so that oil is more likely to enter the upper groove structure 25 than the upper groove structure 25. However, the oil that has entered the lower groove structure 25 is constricted to the opening 21 side. It is difficult to reach the space.

When the parking gear 15 rotates at a high speed in a state where the lower portion of the parking gear 15 is in contact with the oil that has overflowed to the lower portion of the extension case 12, the oil scraped up by the parking gear 15 causes the inner periphery of the extension case 12 to rotate. Is annularly covered and flows along the rotation direction of the parking gear 15. However, since the groove structure 25 (the entrance of the ventilation structure) is open on the center side, the air-rich portion on the center side communicates with the small space through the groove structure 25 to allow the air to reach the oil breather 30. Has been maintained.

Further, since the second through-hole 23 is arranged not at the top of the transmission case 11 but at a position shifted in the rotation direction (arrow) of the parking gear 15, the projection of the top of the transmission case is avoided. The mountability of the automatic transmission is ensured. Since the groove structure 25 is disposed closer to the center in the horizontal direction than the second through hole 23, the transmission case 11 is passed through the second through hole 23 not only while the parking gear 15 is rotating but also when the parking gear 15 is stopped. The oil that has flowed from the side to the extension case 12 side does not flow down near the entrance of the groove structure 25. Therefore, the situation where the oil that has flowed out is pushed into the second hollow space 16 is avoided.

The edge of the first hollow space 22 formed in the extension case 12 forms a shadow for the oil scattered by the parking gear, and blows out from the transmission case 11 side to the extension case 12 side through the second through hole 23. Do not block the flow of oil or air. Further, when the pressure inside the transmission case 11 becomes negative, air is supplied through the second through-hole 23, and the pressure balance is quickly restored. When the transmission mechanism 20 rotates at a high speed, the oil supplied from the oil passage of the output shaft 19 and scattered to the outside and the oil scraped up by the transmission mechanism 20 make the inner peripheral surface of the transmission case 11 cylindrical. It will be in the state of covering. At this time, if the pressure at the innermost portion 26 of the spline 27 is higher than the inside of the extension case 12, the oil mixed with air bubbles blows out to the extension case 12 through the second communication hole 23. The first recessed space 22 of the extension case 12 separates oil and air, and allows oil to flow out gently from the end of the constriction 38. The oil flowing out of the constricted portion 38 is guided downward along the inner periphery of the extension case 12 and does not approach the groove structure 25 (the entrance of the communication path).

Since the rubber member 37 is integrated with the cover member 17, the rubber sheet 37 can be mounted and removed together with the rubber sheet 37, and it is necessary to position the rubber sheet 37 at the time of assembly, as in the case where separate members are overlapped. There is no.

[0039]

According to the first aspect of the present invention, even if the first through hole is completely sunk in the oil due to the oil level rising, etc.
Since the pressure in the upper space of the first housing portion and the pressure in the upper space of the second housing portion are balanced through the second communication hole, the oil level of the second housing portion rises due to an increase in the temperature and pressure of the first housing portion. Is suppressed. Therefore, the oil level of the second casing does not increase to the height of the entrance of the ventilation structure, and the normal communication state of the ventilation structure is maintained. However, even when the volume and properties of the oil change due to the temperature rise, only the air from which the oil has been separated is discharged to the outside through the ventilation structure.

According to the second aspect of the present invention, the partition wall is integrated with one of the first housing and the second housing.
The positioning of the partition is completed only by positioning the housing and the second housing. In addition, since the second through-hole is formed in the partition, it is not necessary to provide a conduit that bypasses the partition and protrudes outside the first housing and the second housing.

According to the third aspect of the present invention, the pressure in the upper space of the first housing and the pressure in the upper space of the second housing are balanced through the second communication hole. As a result, the oil level of the second casing cannot be raised to such an extent that two or more communication paths sink. Then, although there is a possibility that the oil lumps scattered by the rotation of the rotating element temporarily block the communication path, the ventilation structure communicates with the second housing portion through two or more communication paths through a small space. Therefore, even if one communication path is closed, the normal communication state of the ventilation structure is maintained through the other communication path.

According to the fourth aspect of the present invention, since a small space is provided with a constricted structure to separate oil from air mixed with oil, even if some oil enters the ventilation structure through the communication path, the oil is discharged to the outside. Is avoided.

According to the fifth aspect of the present invention, the pressure in the upper space of the first casing and the pressure in the upper space of the second casing are balanced through the second communication hole. The pushing of the oil to the second housing part due to the rise of the oil is suppressed, and the communication path opened to the center side sinks so that the second
The oil level in the housing cannot rise. In addition, since the entrance of the communication path is arranged on the center side with a lot of air avoiding the outer peripheral side where the oil scattered by the rotating element is unevenly distributed, the oil mass may approach the communication path in the rotating state of the rotating element. Is maintained low, and the normal communication state by the ventilation structure is maintained.

According to the sixth aspect of the present invention, regardless of whether the rotating element is in the stopped state or the rotating state, the second through the second communication hole.
Since the oil that has flowed out to the housing portion side is unlikely to drool down to the opening of the communication path, the oil does not easily enter the ventilation structure, and the normal communication state by the ventilation structure is maintained.

According to the seventh aspect of the present invention, since the first recessed space is provided to reduce the change in the flow rate of the oil flowing out to the second casing, a large amount of oil flows out at once through the second communication hole. Also, the situation of invading the ventilation structure is avoided.
In addition, since the edge of the first hollow space prevents oil scattered in the second housing and prevents access to the second communication hole,
Even when the rotating element rotates at a high speed and the oil thickly covers the inner peripheral surface of the second casing, the second through-hole is isolated from the oil to achieve the pressure balance through the second through-hole in a short time.

According to the eighth aspect of the present invention, since the small space is formed by attaching the lid member to the second hollow space formed in the partition, the small space having a complicated shape or the small space having a relatively large volume is formed. Also, a communication path (groove structure) in a direction in which it is difficult to form a through hole can be easily formed. In addition, since the sealing member is integrated with the lid member, positioning of the sealing member is not required when assembling the lid member in the second recessed space of the partition wall, so that the assembling operation is easy and there is no fear of displacement.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view of an automatic transmission.

FIG. 2 is a plan view of a connection surface on a transmission case side.

FIG. 3 is a sectional view taken along the air breather of FIG. 2;

FIG. 4 is an explanatory diagram of a connection surface on an extension case side.

FIG. 5 is an explanatory diagram of a lid member in a small space.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Transmission case 12 Extension case 13 Partition part 14 1st through-hole 15 Parking gear 16 2nd recessed space 17 Cover member 18 Screw member 19 Output shaft 20 Transmission mechanism 21 Opening 22 1st recessed space 23 2nd communication hole 24 Oil pan 25 Groove structure 26 Innermost part 27 Spline 28 Friction plate 30 Oil breather 31, 32, 39 Connecting surface 33 Female screw 34 Rib structure 37 Rubber sheet 38 Neck

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masahiko Kaneda Nissan Motor Co., Ltd., 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Prefecture (72) Inventor Ma Hoshino 2 Nihonsan Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Prefecture

Claims (8)

[Claims] 1. A first housing section for housing a transmission mechanism of an automatic transmission, and a partition section having a first communication hole provided in a lower portion, thereby forming a first housing.
In an air breather structure of an automatic transmission having a second housing part separated from a housing part and a ventilation structure for communicating the second housing part with the outside air to offset a pressure difference between inside and outside, the first housing part An air breather structure for an automatic transmission, characterized in that a second communication hole is provided in the partition wall for communicating the upper space of the first case and the upper space of the second housing part to balance the mutual pressure. 2. The air breather structure of an automatic transmission according to claim 1, wherein said partition portion is formed integrally with one of said first housing portion and said second housing portion. 3. A first housing for storing a transmission mechanism of an automatic transmission, a second housing for storing a rotating element that is axially interlocked with the transmission mechanism, and a first housing and a second housing. A first communication hole that allows oil to move between the two parts is provided at a lower portion thereof to partition the first housing part and the second housing part; In an air breather structure of an automatic transmission having a ventilation structure for canceling a pressure difference, a second communication hole that connects an upper space of a first housing portion and an upper space of a second housing portion and balances mutual pressures. Wherein a small space communicating with the second housing portion through two or more communication paths arranged at a distance in the rotation direction of the rotating element is provided in the ventilation structure. Transmission air breather structure. 4. The air breather for an automatic transmission according to claim 3, wherein the small space has a constricted structure in which a cross-sectional area is reduced between two or more spaces communicating with the respective communication paths. Construction. 5. A first housing for storing a transmission mechanism of an automatic transmission, a second housing for storing a rotating element that is axially interlocked with the transmission mechanism, a first housing and a second housing. A first communication hole that allows oil to move between the two parts is provided at a lower portion thereof to partition the first housing part and the second housing part; In an air breather structure of an automatic transmission having a ventilation structure for canceling a pressure difference, a second communication hole that connects an upper space of a first housing portion and an upper space of a second housing portion and balances mutual pressures. An air breather for an automatic transmission, wherein a small space communicating with the second housing portion is provided in the ventilation structure through a communication path extending upward from the center of the rotating element in a radial direction. Construction. 6. The air breather for an automatic transmission according to claim 3, wherein the second communication hole is arranged so as to be shifted in a rotational direction of the rotary element from a position immediately above the communication path. Construction. 7. A first hollow space having an opening area larger than that of the second communication hole is formed in a portion of the inner wall of the second housing portion facing the second communication hole. 3,
7. An air breather structure for an automatic transmission according to 4, 5, or 6. 8. An automatic transmission, comprising: a second recessed space formed in a partition portion that partitions a first housing portion and a second housing portion of an automatic transmission; and a second recessed space fixed to the partition portion to cover the second recessed space. And a lid member forming a small space communicating with both the outside and the second housing portion of the automatic transmission. The air breather structure of the automatic transmission, wherein a sheet-shaped sealing member for sealing an edge of the second hollow space is provided by the lid member. An air breather structure for an automatic transmission, wherein the air breather structure is attached and fixed to one surface of the lid member prior to assembling.