Breather structure of vehicle transmission

Abstract

To provide a breather structure of a vehicle transmission which inhibits entry of an oil into a breather chamber and achieves simplification of the structure of the breather chamber.SOLUTION: In a breather structure of a transmission 2, a part of a partition wall 5W is expanded to the clutch chamber 8A side to form a space part 45 in which a manual shaft 37 enters. A breather chamber 46 communicating with the outside of a transmission case 3 is provided above the space part 45. The breather chamber 46 is disposed at the clutch chamber 8A side relative to the manual shaft 37 in an axial direction of an input shaft 21.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a breather structure for a vehicle transmission. [Background technology]

[0002] 2. Description of the Related Art A transmission mounted on a vehicle has a breather chamber that communicates between the outside air and the inside of the transmission case in order to release pressure when pressure inside the transmission case increases.

[0003] A known example of a conventional transmission breather structure is the transmission breather structure described in Patent Document 1. This transmission breather structure has a breather chamber formed in the mating surface between the upper wall of the transmission case and the upper wall of the torque converter case.

[0004] The breather chamber has a slit-shaped groove portion that opens downward on the inner surface of the upper wall portion of the transmission case at a position offset axially toward the other end from a specific rotating body of the transmission mechanism to which oil is supplied, and at least a part of the parking member is accommodated in this groove portion. A communication portion that connects the breather chamber to the groove portion is provided above the parking member.

[0005] According to this breather structure, when dynamic pressure is generated in the breather chamber flowing from the opening toward the connecting portion while the vehicle is traveling, this dynamic pressure can easily discharge the oil in the breather chamber through the connecting portion and return it to the internal space through the groove portion. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2015-34567 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the transmission breather structure described in Patent Document 1, a breather chamber is formed at the mating surface between the top wall of the transmission case and the top wall of the torque converter case, so that oil scooped up by a specific rotating body easily enters the breather chamber and is easily blown out to the outside of the transmission case.

[0008] For this reason, it is necessary to form a communication portion or a groove portion for returning the oil in the breather chamber to the internal space, which makes the structure of the breather chamber complicated.

[0009] The present invention has been made in light of the above-mentioned circumstances, and aims to provide a breather structure for a vehicle transmission that can prevent oil from entering the breather chamber and simplify the structure of the breather chamber. [Means for solving the problem]

[0010] The present invention provides a breather structure for a transmission including a transmission case in which a clutch chamber, in which a clutch is accommodated, and a transmission chamber, in which a transmission mechanism including a plurality of rotating shafts is accommodated, are separated by a partition wall, and a parking lock mechanism is accommodated in the transmission chamber and has a manual shaft that rotates by operating a shift lever, wherein a portion of the partition wall bulges toward the clutch chamber to form a space into which the manual shaft enters, a breather chamber that communicates with the outside of the transmission case is provided at an upper portion of the space, and the breather chamber is positioned on the clutch chamber side relative to the manual shaft in the axial direction of the rotating shaft. Effect of the Invention

[0011] As described above, according to the present invention, the intrusion of oil into the breather chamber can be suppressed, and the structure of the breather chamber can be simplified. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a rear view of a vehicle transmission equipped with a breather mechanism according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a view of a vehicle transmission equipped with a breather mechanism according to one embodiment of the present invention, viewed from the left side with the left case removed. [Diagram 3] FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 2, showing a vehicle transmission equipped with a breather mechanism according to one embodiment of the present invention. [Figure 4] FIG. 4 is a diagram showing a state in which a transmission mechanism and a differential gear are removed from the light case of FIG. 2 in a vehicle transmission equipped with a breather mechanism according to one embodiment of the present invention. [Diagram 5] FIG. 5 is a perspective view of a light case showing a breather chamber with a plate removed in a vehicle transmission equipped with a breather mechanism according to one embodiment of the present invention. [Figure 6] FIG. 6 is a view of a breather device and its surroundings, seen from the left, in a vehicle transmission equipped with a breather mechanism according to one embodiment of the present invention. [Figure 7] 7 is a cross-sectional view taken along the line VII-VII of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] A breather structure for a vehicle transmission according to one embodiment of the present invention is a breather structure for a transmission that includes a transmission case in which a clutch chamber in which a clutch is accommodated and a transmission chamber in which a transmission mechanism including a plurality of rotating shafts is accommodated are separated by a partition wall, and a parking lock mechanism that is accommodated in the transmission chamber and has a manual shaft that rotates by operating a shift lever, wherein a portion of the partition wall bulges toward the clutch chamber to form a space into which the manual shaft enters, and a breather chamber that communicates with the outside of the transmission case is provided at the top of the space, and the breather chamber is positioned on the clutch chamber side relative to the manual shaft in the axial direction of the rotating shaft.

[0014] As a result, the breather structure for a vehicle transmission according to one embodiment of the present invention can suppress the intrusion of oil into the breather chamber, and can simplify the structure of the breather chamber. EXAMPLES

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A breather structure for a vehicle transmission according to an embodiment of the present invention will now be described with reference to the drawings.

[0016] 1 to 7 are diagrams showing a breather structure for a vehicle transmission according to one embodiment of the present invention. In Figures 1 to 7, the up, down, front, rear, left and right directions are based on the vehicle transmission when installed in a vehicle, and the front to back direction of the vehicle is the front-to-rear direction, the left to right direction of the vehicle (vehicle width direction) is the left to right direction, and the up and down direction of the vehicle (vehicle height direction) is the up and down direction.

[0017] First, the configuration will be described. 1, an engine 1 as an internal combustion engine and a transmission 2 connected to the engine 1 are provided in an engine room (not shown) of a vehicle. The transmission 2 of this embodiment constitutes a vehicle transmission.

[0018] The transmission 2 includes a transmission case 3 , which includes a left case 4 and a right case 5 .

[0019] Flange portions 4A, 5A are formed on the mating surfaces of the left case 4 and the right case 5, and the left case 4 and the right case 5 are integrated by fastening the flange portions 4A and 5A with bolts 30A.

[0020] As shown in Fig. 2, a transmission mechanism 6 is housed in the transmission case 3. Specifically, the transmission mechanism 6 is disposed in a transmission chamber 8B defined by the left case 4 and the right case 5, and a clutch 7 is housed in a clutch chamber 8A defined by the right case 5 (see Fig. 3).

[0021] A differential gear 10 is housed in a space on the rear side of a transmission chamber 8B defined by the left case 4 and the right case 5, and the differential gear 10 is disposed behind the transmission mechanism 6.

[0022] 2 and 3, a partition wall 5W is provided in the light case 5, and the partition wall 5W is formed on a surface that is approximately perpendicular to the direction in which the axial centers of an input shaft 21 and a counter shaft 22 (described later) extend. The transmission case 3 is partitioned by the partition wall 5W into a clutch chamber 8A that houses the clutch 7 and a transmission chamber 8B that houses the speed change mechanism 6.

[0023] As shown in FIG. 1, the left case 4 is provided with a peripheral wall 4B that surrounds the speed change mechanism 6 in the up-down and front-rear directions.

[0024] The light case 5 is provided with a peripheral wall 5C that surrounds the clutch chamber 8A in the up-down and front-rear directions, and a flange portion 5A is formed at the left end of the peripheral wall 5C. As shown in Fig. 2, the peripheral wall 5C has a bottom wall 5D, an upper wall 5E, a front wall 5F, and a rear wall 5G.

[0025] The transmission 2 inputs the power of the engine 1 to the transmission mechanism 6 via a clutch 7 arranged in a clutch chamber 8A, changes gears in the transmission mechanism 6 by the operation of a synchronizer not shown, and transmits the changed rotation (rotational speed) by a differential device 10 via left and right drive shafts not shown to left and right drive wheels not shown.

[0026] The transmission mechanism 6 is housed in a transmission chamber 8B defined by the left case 4 and the right case 5, and includes an input shaft 21, a counter shaft 22, a reverse shaft 23 and an intermediate shaft 24 that extend in parallel with each other.

[0027] The input shaft 21 can be connected to a crankshaft (not shown) of the engine 1 via a clutch 7 , and the power of the engine 1 is transmitted to the input shaft 21 via the clutch 7 .

[0028] As shown in FIG. 3, the input shaft 21 is provided with an input gear group 21A including, for example, a first-speed input gear to a sixth-speed input gear.

[0029] The counter shaft 22 is provided with a counter gear group 22A including a 1st speed counter gear to a 6th speed counter gear, and a final drive gear 22F that meshes with the final driven gear 11 described later, and the counter gears constituting each gear stage of the counter gear group 22A mesh with the input gear of the input gear group 21A that constitutes the same gear stage.

[0030] 2, a reverse gear 23A is provided on the reverse shaft 23, and the reverse gear 23A meshes with a reverse gear (not shown) provided on the input shaft 21 and the counter shaft 22. The gear shift stages are not limited to six gear stages.

[0031] The differential device 10 has a final driven gear 11, a differential case 12 to which the final driven gear 11 is fixed, a pinion shaft (none of which are shown) housed in the differential case 12, a pair of pinion gears rotatably supported on the pinion shaft, and a pair of side gears that mesh with the pinion gears, and the side gears are respectively connected to left and right drive shafts (not shown).

[0032] The intermediate shaft 24 is provided with a final drive gear 24A, a motor output gear (not shown), and a parking gear 24B that is formed integrally with the motor output gear.

[0033] As shown in FIG. 1, the left case 4 is provided with a motor housing portion 4D, and a motor generator 27 is housed in the motor housing portion 4D.

[0034] As shown in FIG. 2, a motor shaft 27A of the motor generator 27 is disposed obliquely above the front side of the intermediate shaft 24, and a motor input gear 27B is provided on the motor shaft 27A.

[0035] The motor input gear 27B meshes with the motor output gear of the intermediate shaft 24. As a result, the power of the motor generator 27 is transmitted from the motor shaft 27A through the motor input gear 27B, the motor output gear, the intermediate shaft 24, and the final drive gear 24A to the final driven gear 11, and then transmitted from the differential 10 to the left and right drive wheels via the left and right drive shafts.

[0036] On the other hand, the power of the engine 1 is transmitted from the input shaft 21 via the input gear group 21A, the counter gear group 22A, the counter shaft 22 and the final drive gear 22F to the final driven gear 11, and then transmitted from the differential 10 to the left and right drive wheels via the left and right drive shafts.

[0037] The right ends of the input shaft 21, the counter shaft 22, the reverse shaft 23, the intermediate shaft 24 and the differential case 12 are rotatably supported on the partition wall 5W of the right case 5 via bearings not shown, and the left ends of the input shaft 21, the counter shaft 22, the intermediate shaft 24 and the differential case 12 are rotatably supported on the left side wall 4W (see FIG. 1) of the left case 4 via bearings not shown.

[0038] In this embodiment, the input shaft 21, the counter shaft 22, the reverse shaft 23 and the intermediate shaft 24 form a rotating shaft.

[0039] Lubricating oil is stored at the bottom of the transmission case 3, and the final driven gear 11 is immersed in the lubricating oil. Therefore, when the final driven gear 11 rotates counterclockwise in Fig. 2 while the vehicle is moving forward, the lubricating oil scooped up by the final driven gear 11 flows from the rear wall 5G of the peripheral wall 5C along the upper wall 5E to the front wall 5F side, as shown by lubricating oil O1. In addition, the lubricating oil O1 flowing from the rear wall 5G to the front wall 5F side along the upper wall 5E flows along the partition wall 5W.

[0040] As shown in FIG. 4, inside the peripheral wall 5C, the light case 5 has a parking lock mechanism 31 attached to a partition wall 5W.

[0041] The parking lock mechanism 31 includes a parking gear 24B, a parking pole 32, a parking rod 33, a parking cam 34, a cam spring 35, a parking support 36, a manual shaft 37, a detent plate 38, a detent spring 39 and a retainer 40 (see FIG. 2).

[0042] As shown in FIGS. 2 and 4, a plurality of teeth 24a are provided on the outer periphery of the parking gear 24B at equal intervals in the circumferential direction.

[0043] A parking pole shaft 41 passes through the lower end of the parking pole 32, and the parking pole 32 is supported by the parking pole shaft 41 so as to be able to swing freely.

[0044] 2, the retainer 40 is disposed so as to sandwich the parking pole 32 between itself and the partition wall 5W, and is fixed to the partition wall 5W by a bolt 30B. The parking pole shaft 41 is attached to the partition wall 5W and the retainer 40.

[0045] As shown in FIG. 4, a claw portion 32a is formed on the parking pole 32, and the claw portion 32a meshes with the tooth portion 24a of the parking gear 24B when the parking pole 32 swings rightward (clockwise in FIG. 4) around the parking pole shaft 41.

[0046] When the parking pole 32 swings left (counterclockwise in FIG. 4) around the parking pole shaft 41, the claw portion 32a is released from meshing with the tooth portion 24a.

[0047] That is, the parking pawl 32 swings between an engagement position where the claw portion 32a engages with the teeth portion 24a and a release position where the claw portion 32a is separated from the teeth portion 24a.

[0048] When the claw portion 32a meshes with the tooth portion 24a, the rotation of the parking gear 24B is restricted, and the rotation of the intermediate shaft 24 is restricted.

[0049] The intermediate shaft 24 has a final drive gear 24A that meshes with the final driven gear 11, and is linked to the drive wheels via the differential device 10.

[0050] As a result, when the claw portion 32a and the tooth portion 24a mesh, the rotation of the intermediate shaft 24 is restricted, the rotation of the final driven gear 11 of the differential device 10 is restricted, and the rotation of the drive wheels via the drive shaft is restricted, thereby maintaining the vehicle stopped.

[0051] The parking pawl 32 is biased by a return spring 43 in a direction in which the claw portion 32a moves away from the tooth portion 24a.

[0052] The parking rod 33 has a bent portion midway, but basically extends in the front-rear direction along the partition wall 5W of the light case 5. The front end portion is inserted and connected to the lever plate 44 so as to be freely rotatable.

[0053] The lever plate 44 is attached to the upper end of the manual shaft 37 and protrudes radially (horizontally) outward from the manual shaft 37. The parking rod 33 is inserted into the protruding tip of the lever plate 44.

[0054] The lower end of the manual shaft 37 protrudes from the front wall 5F below the light case 5, and one end of a cable member (not shown) is connected to the protruding lower end of the manual shaft 37. The other end of the cable member is connected to a shift lever operated by the driver.

[0055] The cable member transmits the movement of the shift lever when it is switched between the parking position and the non-parking position to the manual shaft 37, causing the manual shaft 37 to rotate.

[0056] The parking rod 33 is movable back and forth in conjunction with the lever plate 44 .

[0057] The parking cam 34 is attached to the rear end of the parking rod 33. The parking rod 33 passes through the parking cam 34, and the parking cam 34 is movable along the axial direction of the parking rod 33.

[0058] A stopper portion 33b is formed on the parking rod 33, and a cam spring 35 is disposed between the stopper portion 33b and the parking cam 34. The cam spring 35 is fitted onto the parking rod 33 and is freely expandable and contractable along the parking rod 33. The movement of the front end portion is restricted by the stopper portion 33b, and the rear end portion is in contact with the parking cam 34.

[0059] The parking cam 34 is formed in a tapered shape that tapers toward the parking pole 32 side.

[0060] The parking support 36 is fixed to the rear side of the retainer 40 (the partition wall 5W side) and is provided integrally with the retainer 40.

[0061] The parking cam 34 is supported by the parking support 36 and moves in the front-rear direction along the shape of the parking support 36, causing the parking pole 32 to swing between an engagement position and a release position.

[0062] The detent plate 38 is attached to the lower part of the manual shaft 37 so as to be located lower than the lever plate 44, and is formed in a sector shape that swings around the manual shaft 37 as the manual shaft 37 rotates.

[0063] A pair of engagement grooves (not shown) are formed on the outer periphery of the detent plate 38. In the transmission 2, the shift positions selected by the shift lever are, for example, P (parking) position, R (reverse) position, N (neutral) position, D (drive) position, and M (manual) position, and are arranged in this order.

[0064] When the driver shifts the gear to the parking position, the manual shaft 37 rotates, causing the detent plate 38 to swing, and the roller member 39A engages with the engagement groove for the parking position.

[0065] In this engaged state, the parking pole 32 swings and is in an engagement position where the claw portion 32a engages with the teeth portion 24a of the parking gear 24B, and the engagement state is maintained by the engagement of the engagement groove with the roller member 39A.

[0066] On the other hand, when the driver shifts into the non-parking position, the manual shaft 37 rotates and the detent plate 38 swings. When the roller member 39A engages with the engagement groove for the non-parking position, the parking cam 34 retreats from the parking support 36, the parking pole 32 swings, and the claw portion 32a of the parking pole 32 is in a release position disengaged from the tooth portion 24a of the parking gear 24B.

[0067] The detent plate 38 and the detent spring 39 constitute a detent mechanism, and when the driver shifts between the parking position and the non-parking position, the roller member 39A engages with and disengages from the engagement groove for the parking position or the engagement groove for the non-parking position, giving the driver a switching sensation (a so-called clicking sensation) when performing the shift operation.

[0068] Furthermore, when the shift operation is completed, the roller member 39A engages with the engagement groove for the parking position or the engagement groove for the non-parking position, thereby positioning the manual shaft 37 in the rotational direction.

[0069] 3, the front portion of the partition wall 5W bulges toward the clutch chamber 8A, and the bulging portion forms a space 45. That is, the space 45 in this embodiment is formed at the front end portion of the light case 5.

[0070] In this embodiment, the bulging portion that forms the space 45 is referred to as the bulging portion of the partition 5W, and the portion of the partition 5W other than this bulging portion is referred to as a partition portion 5w.

[0071] Specifically, the space 45 is surrounded by the manual-shaft-side partition wall 5H, the vertical wall 5I, and the front wall 5F. The manual-shaft-side partition wall 5H is located closer to the clutch chamber 8A than the front end 5a of the partition wall portion 5w of the partition wall 5W in the axial direction of the input shaft 21, and separates the clutch chamber 8A from the space 45.

[0072] The vertical wall 5I extends in the axial direction of the input shaft 21, connects the front end 5a of the partition wall portion 5w of the partition wall 5W to the rear end of the manual shaft side partition wall 5H, and separates the clutch chamber 8A from the space 45. As shown in Fig. 4, the vertical wall 5I extends in the vertical direction along the manual shaft 37. Similarly, the manual shaft side partition wall 5H also extends in the vertical direction along the manual shaft 37.

[0073] The manual shaft 37 is housed in the space 45. More specifically, the manual shaft 37 is disposed so that a portion of it enters the space 45. The manual shaft 37 penetrates the lower part of the front wall 5F and protrudes to the outside of the light case 5, and a boss-shaped lower support part 5J that rotatably supports the lower part of the manual shaft 37 is provided at the lower part of the front wall 5F (see FIG. 4).

[0074] An upper support portion 5K is provided on the upper portion of the manual shaft side partition wall 5H so as to protrude into the space portion 45. The upper support portion 5K protrudes from the manual shaft side partition wall 5H toward the transmission chamber 8B. The upper end portion of the manual shaft 37 is rotatably supported by the upper support portion 5K.

[0075] In other words, the lower support part 5J and the upper support part 5K are disposed within the space part 45, and the manual shaft 37 is rotatably supported by the lower support part 5J and the upper support part 5K so as to be accommodated in the space part 45.

[0076] As shown in FIGS. 3 and 5, a breather chamber 46 is provided in the upper part of the space 45, and the breather chamber 46 is disposed closer to the clutch chamber 8A than the manual shaft 37 in the axial direction of the input shaft 21.

[0077] The breather chamber 46 is separated from the transmission chamber 8B by a plate 47. The plate 47 is disposed on the transmission chamber 8B side away from an upper portion of the manual shaft side partition wall 5H in the axial direction of the input shaft 21 (see FIG. 7).

[0078] 6, the plate 47 is formed in an L-shape having a vertically elongated portion 47A and a horizontally elongated portion 47B so as to wrap around the periphery of the upper support portion 5K. The vertically elongated portion 47A is disposed between the upper support portion 5K and the front wall 5F and extends downward therefrom.

[0079] The horizontally long portion 47B is disposed between the upper support portion 5K and the upper wall 5E and extends rearward therefrom. A plate attachment portion 5L is provided on the manual shaft side partition wall 5H below the front side of the upper support portion 5K (see FIG. 5), and the lower portion of the vertically long portion 47A is fixed to the plate attachment portion 5L by a bolt 30C.

[0080] The horizontally elongated portion 47B extends downward so as to be located behind the upper support portion 5K. This downward extension forms a notch 47a in the horizontally elongated portion 47B, and the upper support portion 5K is disposed between the vertically elongated portion 47A and the notch 47a.

[0081] The back surface (right side surface) of the rear end portion of the horizontally elongated portion 47B abuts and overlaps with the surface (left side surface) of the front end portion 5a of the partition portion 5w of the partition wall 5W, and the surface of the horizontally elongated portion 47B is continuous with the partition wall 5W so as to be approximately flush with the surface of the partition portion 5w of the partition wall 5W.

[0082] 5, the upper support part 5K and the upper part of the vertical wall 5I arranged behind it are connected by a rib 5M. In other words, the rib 5M is connected to the upper part of the manual shaft side partition wall 5H, the upper support part 5K, and the upper part of the manual shaft side partition wall 5H, forming a horizontal surface.

[0083] As shown in FIG. 7, the rib 5M is a wall extending horizontally so as to separate the breather chamber 46 from a space 48 below the breather chamber 46, and the space 48 below the breather chamber 46 communicates with the transmission chamber 8B.

[0084] The left edge of the rib 5M does not abut against the horizontal portion 47B of the plate 47, but is formed to be spaced a predetermined distance from the horizontal portion 47B. The lower space 48 is the space between the vertical wall 5I and the manual shaft 37, and has a boss disposed below, forming a space surrounded on all sides.

[0085] An air vent 5m is formed in the rib 5M at a position on the manual shaft side bulkhead 5H side, and the air vent 5m communicates with the internal space of the breather chamber 46 and the lower space 48. The breather chamber 46 and the transmission chamber 8B communicate with each other via the lower space 48 and the air vent 5m.

[0086] That is, the breather chamber 46 is surrounded by the upper part of the manual shaft side partition wall 5H, the upper support part 5K, the upper part of the vertical wall 5I, the rib 5M, and the horizontally elongated part 47B of the plate 47.

[0087] A lower end 47b of the horizontally elongated portion 47B of the plate 47 is located at the same height as the lower surface of the rib 5M, and the air hole 5m is covered from the transmission chamber 8B side by the horizontally elongated portion 47B.

[0088] As a result, the rib 5M and the plate 47 form a gap through which air can enter the breather chamber 46 from the space 48 below the breather chamber 46.

[0089] 7, a gap is formed between the lower end 47b of the horizontally elongated portion 47B and the rib 5M, and the breather chamber 46 and the transmission chamber 8B also communicate with each other through this gap. The breather chamber 46 and the transmission chamber 8B also communicate with each other through gaps between the vertically elongated portion 47A, the upper support portion 5K, and the front wall 5F.

[0090] The gap between the vertical portion 47A, the upper support portion 5K and the front wall 5F is positioned on the opposite side of the final driven gear 11 from the breather chamber 46 and opens downward, thereby more effectively preventing oil from entering the breather chamber 46.

[0091] 3, the manual shaft side partition 5H on the clutch chamber 8A side with respect to the rib 5M in the axial direction of the input shaft 21 has a bulging wall 5N. That is, a part of the manual shaft side partition 5H bulges toward the clutch chamber 8A side more than the manual shaft side partition 5H. This increases the volume of the breather chamber 46 by the amount of the bulging wall 5N.

[0092] As shown in FIG. 7, a breather hole 5b is formed above the manual shaft side partition wall 5H and the plate 47, and the breather chamber 46 communicates with the outside of the transmission case 3 via the breather hole 5b.

[0093] Specifically, the breather chamber 46 has a ceiling wall 5p located above the manual shaft side partition wall 5H and the plate 47. The ceiling wall 5p is formed from the front part of the upper wall 5E of the light case 5.

[0094] The breather hole 5b extends from the ceiling wall 5p to an upper surface 5c of the light case 5 located above the ceiling wall 5p.

[0095] A breather pipe 50 is connected to an upper end of the breather hole 5b, and the breather chamber 46 communicates with the outside of the transmission case 3 through the breather hole 5b and the breather pipe 50. The breather hole 5b in this embodiment constitutes a communication portion.

[0096] The breather pipe 50 takes in outside air from the outside of the transmission case 3 through the breather hole 5b and the breather chamber 46 into the transmission chamber 8B when the pressure inside the transmission case 3 (that is, the transmission chamber 8B) is low.

[0097] On the other hand, when the pressure in the transmission chamber 8B becomes high, the breather pipe 50 releases the pressure (air) inside the transmission chamber 8B to the outside of the transmission case 3 through the breather chamber 46 and the breather hole 5b.

[0098] Next, the effect of the breather structure of the transmission 2 of this embodiment will be described. The breather structure of the transmission 2 of this embodiment includes a transmission case 3 in which a clutch chamber 8A in which the clutch 7 is housed and a transmission chamber 8B in which the transmission mechanism 6 comprising an input shaft 21, a counter shaft 22, a reverse shaft 23 and an intermediate shaft 24 are housed are separated by a partition wall 5W.

[0099] In addition, the breather structure of the transmission 2 is equipped with a parking lock mechanism 31 that is housed in the transmission chamber 8B and has a manual shaft 37 that rotates by operating the shift lever, and the right end portions (end portions) of the input shaft 21, counter shaft 22, reverse shaft 23, intermediate shaft 24 and differential case 12 are each rotatably supported by the partition wall 5W.

[0100] In addition, the breather structure of the transmission 2 is such that a part of the partition wall 5W bulges toward the clutch chamber 8A to form a space 45 into which the manual shaft 37 fits.

[0101] A breather chamber 46 that communicates with the outside of the transmission case 3 is provided at the upper part of the space 45, and the breather chamber 46 is disposed closer to the clutch chamber 8A than the manual shaft 37 in the axial direction of the input shaft 21.

[0102] Here, as shown in FIG. 3, a dead space exists between the partition wall 5W and the clutch 7.

[0103] This dead space is utilized, and by forming a space 45 that expands the transmission chamber 8B toward the clutch chamber 8A by bulging the partition 5W toward the clutch chamber 8A, and by arranging the manual shaft 37 in the space 45, the installation space for the manual shaft 37 inside the transmission case 3 can be increased.

[0104] In other words, since there is a dead space between the partition wall 5W and the clutch 7, a space for forming the space portion 45 in the transmission chamber 8B can be secured by the amount of the dead space.

[0105] By forming the breather chamber 46 on the rear side of the manual shaft 37, the breather chamber 46 can be disposed on the clutch chamber 8A side with respect to the partition wall portion 5w of the partition wall 5W and the manual shaft 37.

[0106] Therefore, the oil that is thrown forward by the final driven gear 11 and flows along the partition wall portion 5w of the partition wall 5W can be prevented from entering the breather chamber 46.

[0107] In other words, the oil that is thrown forward by the final driven gear 11 and flows along the partition portion 5w of the partition 5W flows forward along the partition 5W and is unlikely to be directed rightward from the partition portion 5w of the partition 5W. For this reason, by forming the breather chamber 46 on the clutch chamber 8A side with respect to the partition portion 5w of the partition 5W, the oil is unlikely to reach the breather chamber 46.

[0108] As a result, the oil can be prevented from blowing out from the breather chamber 46 through the breather hole 5b and the breather pipe 50 to the outside of the transmission case 3.

[0109] Furthermore, since it is possible to prevent oil from entering the breather chamber 46, it is not necessary to form a complicated oil return structure in the breather chamber 46. Therefore, the structure of the breather chamber 46 can be simplified.

[0110] In this way, the breather structure of the transmission 2 of this embodiment prevents oil from entering the breather chamber 46, and allows the breather chamber 46 to be simplified.

[0111] Furthermore, according to the breather structure of the transmission 2 of this embodiment, the space 45 is separated from the clutch chamber 8A by the manual shaft side partition 5H, which is located closer to the clutch chamber 8A than the partition portion 5w of the partition 5W in the axial direction of the input shaft 21.

[0112] The breather chamber 46 is surrounded by an upper portion of the partition wall 5H on the manual shaft side and a plate 47 disposed away from the upper portion of the partition wall 5H on the manual shaft side in the axial direction of the input shaft 21 from the clutch chamber 8A side.

[0113] In addition, a breather hole 5b that communicates between the breather chamber 46 and the outside of the transmission case 3 is provided above the manual shaft side partition wall 5H and the plate 47.

[0114] This allows the plate 47 to block the oil flowing along the partition wall portion 5w of the partition wall 5W, and prevents the oil from entering the breather chamber 46 more effectively.

[0115] In addition, the rear end of the horizontally elongated portion 47B abuts against the front end 5a of the partition wall 5W, and the horizontally elongated portion 47B is continuous with the partition wall portion 5w of the partition wall 5W so as to be substantially flush with the partition wall portion 5w of the partition wall 5W. This allows oil flowing along the partition wall portion 5w of the partition wall 5W to flow forward by the plate 47, and makes it possible to more effectively prevent oil from entering the breather chamber 46.

[0116] According to the breather structure of the transmission 2 of this embodiment, the space 45 extends in the axial direction of the input shaft 21 and is separated from the clutch chamber 8A by a vertical wall 5I that connects the partition portion 5w of the partition 5W and the manual shaft side partition 5H. An upper support portion 5K that rotatably supports the upper end of the manual shaft 37 is provided on the upper part of the manual shaft side partition 5H.

[0117] The upper support part 5K, the upper part of the manual shaft side partition wall 5H, and the upper part of the vertical wall 5I are connected by ribs 5M, and the breather chamber 46 is surrounded by the upper part of the manual shaft side partition wall 5H, the upper support part 5K, the upper part of the vertical wall 5I, the ribs, and the plate 47.

[0118] As a result, the upper support portion 5K that supports the upper end portion of the manual shaft 37 can be reinforced by the rib 5M, and the supporting rigidity of the manual shaft 37 can be increased.

[0119] Furthermore, in addition to utilizing the upper support part 5K that supports the upper end part of the manual shaft 37 and the ribs 5M that reinforce the upper support part 5K, the breather chamber 46 can be formed in the space part 45 by the upper part of the manual-shaft side partition wall 5H and the upper part of the vertical wall 5I, so that the breather chamber 46 of a simple structure can be effectively formed in the space part 45.

[0120] Further, according to the breather structure of the transmission 2 of this embodiment, the breather hole 5b that communicates the space 45 and the breather chamber 46 is formed in the rib 5M.

[0121] As a result, good communication between the transmission chamber 8B and the breather chamber 46 can be maintained by utilizing the rib 5M, and only air can be discharged from the breather chamber 46 by the breather chamber 46 having a simple structure.

[0122] According to the breather structure of the transmission 2 of this embodiment, the space 45 is formed at the front end of the light case 5, and the breather chamber 46 has a ceiling wall 5p located above the manual shaft side partition 5H and the plate 47.

[0123] The breather hole 5b extends from the ceiling wall 5p to an upper surface 5c of the light case 5 located above the ceiling wall 5p, and a breather pipe 50 is connected to the upper end of the breather hole 5b.

[0124] This allows the breather hole 5b and the breather pipe 50 to be disposed on the front side of the light case 5. Therefore, when an actuator or a shift tower that controls the transmission 2 is disposed above the light case 5, the breather pipe 50 can be easily disposed while avoiding the actuator or the shift tower.

[0125] Although an embodiment of the invention has been disclosed, it will be apparent to one of ordinary skill in the art that modifications may be made therein without departing from the spirit and scope of the invention, and it is intended that all such modifications and equivalents be included in the following claims. [Explanation of symbols]

[0126] 2. Transmission (vehicle transmission) 5b Breather hole (connection part) 5c Top (top of transmission case) 5H Manual shaft side bulkhead 5I Vertical wall 5K Upper support part (support part) 5M Rib 5p Ceiling Wall 6. Transmission mechanism 7. Clutch 8A Clutch chamber 8B Gearbox compartment 21 Input shaft (rotating shaft) 22 Countershaft (rotating shaft) 23 Reverse shaft (rotation shaft) 24 Intermediate shaft (rotating shaft) 31 Parking lock mechanism 37 Manual Shaft 45 Space section 46 Breather Room 47 Plate 50 Breather pipe

Claims

1. A breather structure for a transmission comprising: a transmission case in which a clutch chamber in which a clutch is accommodated and a transmission chamber in which a transmission mechanism including a plurality of rotating shafts is accommodated are separated by a partition; and a parking lock mechanism accommodated in the transmission chamber and having a manual shaft that rotates by operation of a shift lever, a portion of the partition wall bulges toward the clutch chamber to form a space into which the manual shaft is inserted, a breather chamber communicating with the outside of the transmission case is provided at an upper portion of the space, 13. A breather structure for a vehicle transmission, comprising: a breather chamber disposed on a side of the manual shaft that faces the clutch chamber in an axial direction of the rotating shaft;

2. the space is separated from the clutch chamber by a manual shaft side partition wall that is located closer to the clutch chamber than the partition wall in the axial direction of the rotating shaft, the breather chamber is surrounded by an upper portion of the partition wall on the manual shaft side and a plate that is disposed away from the upper portion of the partition wall on the manual shaft side in the axial direction of the rotating shaft from the clutch chamber side, 2. The breather structure for a vehicle transmission according to claim 1, wherein a communication portion that communicates the breather chamber with the outside of the transmission case is provided above the manual shaft side partition wall and the plate.

3. the space portion extends in an axial direction of the rotating shaft, and is separated from the clutch chamber by a vertical wall connecting the partition wall and the manual shaft side partition wall, a support portion that rotatably supports an upper end portion of the manual shaft is provided on an upper portion of the manual shaft side partition wall, the support portion, an upper portion of the manual shaft side partition wall, and an upper portion of the vertical wall are connected to each other by a rib, 3. The breather structure for a vehicle transmission according to claim 2, wherein the breather chamber is surrounded by an upper portion of the partition wall on the manual shaft side, the support portion, an upper portion of the vertical wall, the rib, and the plate.

4. 4. The breather structure for a vehicle transmission according to claim 3, wherein the rib is formed with a communication hole that communicates the space with the breather chamber.

5. The space is formed at an end of the transmission case, the breather chamber has a ceiling wall located above the manual shaft side partition wall and the plate, The communication portion extends from the ceiling wall to an upper surface of the transmission case located above the ceiling wall, 5. The breather structure for a vehicle transmission according to claim 2, wherein a breather pipe is connected to an upper end of the communication portion.

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