JP7487616B2 - Power transmission - Google Patents

Description

The present invention relates to a power transmission device.

Power transmission devices such as transmissions mounted on vehicles are configured to supply lubricating oil to shafts, gears, etc. by scooping up the lubricating oil stored in the bottom of a case member with rotating gears, thereby lubricating the shafts, gears, etc.

For this reason, it is necessary to store a predetermined amount of lubricating oil at the bottom of the case member and ensure that the oil level is at or above a predetermined height.

However, if the oil level of the lubricating oil is kept above a certain level, the agitation resistance of the gears immersed in the lubricating oil increases. For this reason, it is necessary to suppress the increase in the agitation resistance of the gears.

Conventionally, the lubrication structure of a transmission described in Patent Document 1 is known as a structure that suppresses an increase in the stirring resistance of gears.

In a conventional transmission lubrication structure, the case member is divided into a first storage chamber and a second storage chamber by a partition wall, and a third-speed output gear and a third-speed gear are installed in the second storage chamber and are aligned vertically and mesh with each other.

A first oil separator is installed around the third-speed output gear located below the third-speed gear along the outer circumferential surface of the third-speed output gear, and a second oil separator is installed around the third-speed gear located above the third-speed output gear.

A first communication hole and a third communication hole are formed in the lower part and the vertical center of the partition wall, which connect the first storage chamber and the second storage chamber and allow lubricating oil to flow between the first storage chamber and the second storage chamber.

The lubricating oil scooped up by the third-speed output gear is supplied along the first oil separator to the meshing portion between the third-speed output gear and the third-speed gear, then flows from the meshing portion along the second oil separator and is introduced into the first storage chamber via the third communication hole. The lubricating oil introduced into the first storage chamber is returned from the first storage chamber to the second storage chamber via the first communication hole.

In the lubrication structure of conventional transmissions, the oil stored in the case member circulates between the first and second storage chambers, lowering the level of the lubricating oil in the second storage chamber and reducing the stirring resistance of the third-speed output gear, which is immersed in the lubricating oil.

JP 2016-3761 A

However, in the lubrication structure of conventional transmissions, the lubricating oil guided by the first oil separator to the meshing portion between the third-speed output gear and the third-speed gear collides with the meshing portion.

As a result, it is difficult for the lubricating oil to circulate from the second storage chamber to the first storage chamber, and the level of the lubricating oil in the second storage chamber may become high. This increases the stirring resistance of the third-speed output gear, which is immersed in the lubricating oil, and may cause the power transmission efficiency of the transmission to deteriorate.

The present invention was made in light of the above-mentioned circumstances, and aims to provide a power transmission device that can reliably reduce the amount of lubricating oil stored at the bottom of the case member and reduce the stirring resistance of the gears.

The present invention relates to a power transmission device comprising: a case member at the bottom of which lubricating oil is stored; a rotating shaft having a plurality of gear members and rotatably supported by the case member; an oil separator installed along an outer peripheral surface of the plurality of gear members; a guide portion provided on the oil separator so as to be located radially outward of a predetermined gear member of the plurality of gear members; and a catch tank in which lubricating oil scooped up by the predetermined gear member is stored, the catch tank having a side wall and an opening provided at an upper end of the side wall, the guide portion extending from a lower end of the guide portion toward an upper end thereof so as to move away from a central axis of rotation of the predetermined gear member, The side wall of the catch tank is located on an extension line of the direction in which the guide portion extends, the specified gear member is composed of the gear member having the largest diameter among the plurality of gear members, a notch or opening is formed in the lower part of the oil separator that opens from the lower end in the direction in which the guide portion extends along the circumferential direction of the specified gear member, the catch tank has a covering portion that covers the lower parts of at least one or more gear members among the plurality of gear members excluding the specified gear member, and the lower part of the specified gear member protrudes downward through the notch or opening of the oil separator and is immersed in lubricating oil .

In this way, the present invention can reliably reduce the amount of lubricating oil stored at the bottom of the case member, thereby reducing the stirring resistance of the gears.

FIG. 1 is a vertical cross-sectional view of a power transmission device according to an embodiment of the present invention, taken along the axis of an input shaft. FIG. 2 is a rear view of the center case of the power transmission device according to one embodiment of the present invention with the rear case removed from the center case. FIG. 3 is a view of the counter shaft, the oil separator, and the parking lock mechanism of the power transmission device according to one embodiment of the present invention, viewed obliquely from below and rear on the right side. FIG. 4 is a view of the counter shaft, oil separator, parking lock mechanism, and catch tank of the power transmission device according to one embodiment of the present invention, viewed obliquely from above and rear on the left. FIG. 5 is a top view of the counter shaft, the oil separator, the parking lock mechanism, and the catch tank of the power transmission device according to one embodiment of the present invention. FIG. 6 is a bottom view of the counter shaft, the oil separator, the parking lock mechanism, and the catch tank according to one embodiment of the present invention. FIG. 7 is a cross-sectional view taken along the line VII-VII of FIG. FIG. 8 is a diagram showing the positional relationship between the catch tank, the oil separator, and the detent plate when the power transmission device according to one embodiment of the present invention is viewed from the vehicle width direction. FIG. 9 is a rear view of the center case of a power transmission device according to one embodiment of the present invention with the rear case removed, showing the state in which the counter shaft, oil separator, parking lock mechanism and catch tank have been removed. FIG. 10 is a front view of an oil separator for a power transmission device according to one embodiment of the present invention.

The power transmission device according to one embodiment of the present invention includes a case member at the bottom of which lubricating oil is stored, a rotating shaft having multiple gear members and rotatably supported by the case member, an oil separator installed along the outer circumferential surface of the multiple gear members, a guide portion provided on the oil separator so as to be positioned radially outward of a specific gear member among the multiple gear members, and a catch tank in which lubricating oil scooped up by the specific gear member is stored, the catch tank having a side wall and an opening provided at the upper end of the side wall, the guide portion extends from the lower end of the guide portion toward the upper end thereof so as to move away from the central axis of rotation of the specific gear member, and the side wall of the catch tank is located on an extension line of the direction in which the guide portion extends.

As a result, the power transmission device according to one embodiment of the present invention can reliably reduce the amount of lubricating oil stored at the bottom of the case member, thereby reducing the stirring resistance of the gears.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A power transmission device according to an embodiment of the present invention will now be described with reference to the drawings.
1 to 10 are diagrams showing a power transmission device according to an embodiment of the present invention. In Fig. 1 to 10, the up, down, front, rear, left and right directions are based on the power transmission device installed in a vehicle, the front and rear direction of the vehicle is the front-rear direction, the left and right direction of the vehicle (vehicle width direction) is the left and right direction, and the up and down direction of the vehicle (vehicle height direction) is the up and down direction.

First, the configuration will be described.
1, a vehicle 1 is equipped with a transmission 2, and an engine 3 is connected to the transmission 2. The transmission 2 and the engine 3 are installed vertically below a floor panel 1A of the vehicle 1. That is, the vehicle 1 of this embodiment is a rear-wheel drive vehicle. The engine 3 burns fuel and converts thermal energy into mechanical energy.

The transmission 2 includes a transmission case 4, which includes a front case 6, a center case 7, a rear case 8, and an extension case 9. In this embodiment, the transmission 2 constitutes a power transmission device, and the transmission case 4 constitutes a case member.

The front case 6 houses a torque converter 10, which has a front cover 11 and a pump shell 12 connected to the front cover 11.

The front cover 11 is connected to the crankshaft 3S of the engine 3 via a drive plate 13, and the front cover 11 and the pump shell 12 rotate together with the crankshaft 3S.

The torque converter 10 includes a pump impeller 14 fixed to the pump shell 12 and a turbine runner 15 facing the pump impeller 14. The turbine runner 15 is connected to a turbine shaft 16 via a turbine hub (not shown).

Hydraulic oil is supplied to the torque converter 10, and when power is transmitted from the engine 3 to the pump shell 12, the centrifugal force caused by the rotation of the pump impeller 14 causes the hydraulic oil inside the torque converter 10 to flow from the pump impeller 14 toward the turbine runner 15.

This flow of hydraulic oil rotates the turbine runner 15, and the power of the engine 3 is transmitted from the turbine runner 15 to the turbine shaft 16.

A stator 15S is installed between the pump impeller 14 and the turbine runner 15. The stator 15S amplifies the power of the engine 3 by converting the flow of work from the turbine runner 15 toward the pump impeller 14 to follow the direction of rotation of the pump impeller 14.

A partition wall 21A is formed in the front case 6. The partition wall 21A divides the internal space of the front case 6 into a torque converter chamber 22 that houses the torque converter 10 and a clutch chamber 23 that houses the friction clutch 31.

The turbine shaft 16 is rotatably supported by the partition wall 21A. An oil pump 26 is housed in the torque converter chamber 22 of the front case 6, and the oil pump 26 is, for example, a trochoid type oil pump.

A dry friction clutch 31 is housed in the clutch chamber 23 of the front case 6, and the friction clutch 31 is installed at the front end of the input shaft 41. The input shaft 41 is housed in the front case 6, the center case 7, and the rear case 8, and extends in the fore-and-aft direction of the vehicle 1.

The front end of the input shaft 41 is supported for relative rotation to the rear end of the turbine shaft 16, and the rear end of the input shaft 41 is supported for relative rotation to the output shaft 42.

As shown in Figures 1 and 9, a partition wall 21B is provided in the center case 7. As shown in Figure 9, the partition wall 21B has a through hole 21a through which the input shaft 41 passes, a bearing support portion 21b that rotatably supports the input shaft 41 via bearing 35A, a bearing support portion 21c that rotatably supports the axial tip end of the counter shaft 46 via bearing 35B, and a bearing support portion 21d that rotatably supports the reverse shaft 43 (see Figure 2) via bearing 35C.

As shown in FIG. 1, the friction clutch 31 has a clutch wheel disc 32 that is connected to the turbine shaft 16 and rotates integrally with the turbine shaft 16, and a clutch disc 33 that is mounted on the input shaft 41 and is rotatable integrally with the input shaft 41 and is movable in the axial direction of the input shaft 41.

When the clutch disc 33 is engaged with the clutch wheel disc 32, the friction clutch 31 transmits the power of the engine 3 to the input shaft 41 via the torque converter 10, and when the clutch wheel disc 32 is separated from the clutch disc 33, the friction clutch 31 cuts off the power transmitted from the engine 3 to the input shaft 41.

As shown in FIG. 1, the center case 7 and the rear case 8 house a counter shaft 46, which is installed below the input shaft 41. In this embodiment, the counter shaft 46 constitutes a rotating shaft.

On the input shaft 41, from the friction clutch 31 side toward the output shaft 42, a fourth-speed input gear 41A, a third-speed input gear 41B, a second-speed input gear 41C, a first-speed input gear 41D, and a reverse input gear 41E are installed, which constitute the gears for shifting.

The diameters of the input gears 41A to 41D are such that the fourth-speed input gear 41A is the largest, followed by the third-speed input gear 41B, the second-speed input gear 41C, and the first-speed input gear 41D. In other words, the first-speed input gear 41D has the smallest diameter.

A fifth-speed clutch gear 42A is provided at the front end of the output shaft 42, and the fifth-speed clutch gear 42A is composed of a dog that rotates integrally with the output shaft 42.

The counter shaft 46 is provided with a fourth-speed counter gear 46A, a third-speed counter gear 46B, a second-speed counter gear 46C, a first-speed counter gear 46D, and a counter drive gear 46E, arranged from the friction clutch 31 side toward the output shaft 42.

The counter gear 46A to the first-speed counter gear 46D are meshed with the fourth-speed input gear 41A to the first-speed input gear 41D, which respectively constitute the same gear stage. The counter drive gear 46E is meshed with the counter driven gear 42B provided on the output shaft 42.

The diameters of the counter gears 46A to 46D are such that the fourth-speed counter gear 46A is the smallest, followed by the third-speed counter gear 46B, the second-speed counter gear 46C, and the first-speed counter gear 46D. In other words, the diameter of the first-speed counter gear 46D is the largest. The counter drive gear 46E is formed to be approximately the same size as the fourth-speed counter gear 46A.

In this embodiment, the 4th-speed counter gear 46A, the 3rd-speed counter gear 46B, the 2nd-speed counter gear 46C, and the 1st-speed counter gear 46D constitute gear members. The 1st-speed input counter gear 46D constitutes a specified gear, and the 2nd-speed counter gear 46C constitutes an adjacent gear.

The power of the crankshaft 3S of the engine 3 is transmitted from the turbine shaft 16 of the torque converter 10 to the input shaft 41, and then transmitted from the input gears 41A, 41B, 41C, and 41D that constitute the same gear stage to the counter shaft 46 via the counter gears 46A, 46B, 46C, and 46D.

The power of the engine 3 transmitted to the counter shaft 46 is transmitted from the counter drive gear 46E of the counter shaft 46 via the counter driven gear 42B to the output shaft 42. The differential device, the drive shaft, and the driven rear wheels are all connected to the output shaft 42 via a propeller shaft (not shown).

As a result, the power transmitted to the output shaft 42 is transmitted to the differential device via the propeller shaft, distributed to the left and right drive shafts by the differential device, and then transmitted to the driven rear wheels.

The reverse input gear 41E is connected to a reverse driven gear (not shown) provided on the counter shaft 46 via a reverse idler gear (not shown) provided on the reverse shaft 43.

As shown in FIG. 1, an oil separator 50 is installed inside the center case 7 and the rear case 8. As shown in FIG. 3 and FIG. 4, the oil separator 50 is installed along the outer circumferential surfaces of the counter gears 46B, 46C, and 46D.

Lubricating oil is stored in the bottom of the transmission case 4. Figure 2 shows the lubricating oil O stored in the rear case 8 of the transmission case 4.

As shown in Figures 3 and 5, the oil separator 50 has a cover portion 50A, a shielding portion 50B, and a guide portion 50C.

The cover portion 50A extends along the outer periphery of the second-speed counter gear 46C and the third-speed counter gear 46B, and has a gear-side cover portion 50P that covers the lower portions of the second-speed counter gear 46C and the third-speed counter gear 46B.

The cover portion 50A has an axle side cover portion 50Q that covers the lower portion of the counter shaft 46 between the second-speed counter gear 46C and the first-speed counter gear 46D, and the lower portion of the axle side cover portion 50Q is located higher than the lower portion of the gear side cover portion 50P. The shielding wall portion 50B is provided at the rear end portion of the axle side cover portion 50Q.

As shown in FIG. 5, the guide portion 50C is provided at the rear end of the shielding portion 50B and protrudes rearward from the shielding portion 50B so as to be positioned radially outward from the first-speed counter gear 46D.

As shown in FIG. 6, a notch 50a is formed in the lower part of the oil separator 50, and the notch 50a is cut out along the circumferential direction of the first-speed counter gear 46D from the lower end 50b in the direction in which the guide part 50C extends.

The lower part of the first-speed counter gear 46D protrudes downward through the notch 50a and is submerged in lubricating oil O (see Figure 2).

When the oil separator 50 is not installed in the transmission case 4 and the engine 3 is stopped, the oil level of the lubricating oil O stored in the transmission case 4 is located below the bottom of the fourth-speed counter gear 46A and is at a height that submerges the third-speed counter gear 46, the second-speed counter gear 46C, and the first-speed counter gear 46D.

When the lubricating oil O is stored in the transmission case 4 to this height, a sufficient amount of lubricating oil can be secured to lubricate the parts to be lubricated.

As a result, when the oil separator 50 is installed in the transmission case 4, the lower part of the first-speed counter gear 46D, which has the largest diameter among the counter gears, is deeply immersed in the lubricating oil O.

The oil separator 50 has a cover portion 50A that covers the lower portions of the second-speed counter gear 46C and the third-speed counter gear 46B, separating the second-speed counter gear 46C and the third-speed counter gear 46B from the lubricating oil O, preventing the second-speed counter gear 46C and the third-speed counter gear 46B from being submerged in the lubricating oil O.

This prevents the stirring resistance of the second-speed counter gear 46C and the third-speed counter gear 46B from increasing.

As shown in FIG. 2, a catch tank 51 is installed in the rear case 8. The catch tank 51 is installed diagonally above and to the left of the counter shaft 46 and diagonally below and to the left of the input shaft 41.

The catch tank 51 is installed vertically between the upper end 41u of the first-speed input gear 41D and the lower end 46u of the first-speed counter gear 46D.

The catch tank 51 is installed on the opposite side of the input shaft 41 from the reverse shaft 43 in the vehicle width direction, and the input shaft 41 is installed between the catch tank 51 and the reverse shaft 43 in the vehicle width direction.

As shown in Figures 4 and 5, the catch tank 51 has a bottom wall 51A, a front wall 51B extending upward from the front end of the bottom wall 51A, and a rear wall 51C extending upward from the rear end of the bottom wall 51A.

The catch tank 51 has a left side wall 51D that extends upward from the left end of the bottom wall 51A and connects the left end of the front wall 51B to the left end of the rear wall 51C, and a right side wall 51E that extends upward from the right end of the bottom wall 51A and connects the right end of the front wall 51B to the right end of the rear wall 51C.

Openings 51F are formed at the upper end of the catch tank 51, i.e., the upper ends of the front wall 51B, rear wall 51C, left side wall 51D, and right side wall 51E.

The lubricating oil scooped up by the first-speed counter gear 46D is introduced into the catch tank 51 through the opening 51F and is temporarily stored in the catch tank 51.

As shown in FIG. 5, the catch tank 51 is installed so that the opening 51F extends in the front-rear direction. A bulge 51e is formed in the right side wall 51E of the catch tank 51, and the bulge 51e bulges forward of the first-speed counter gear 46D and from the center of the right side wall 51E in the front-rear direction toward the first-speed counter gear 46.

As a result, the width of the opening 51F of the catch tank 51 in the vehicle width direction is larger in the center in the fore-and-aft direction, where the bulge 51e is located, than in the front and rear in the fore-and-aft direction.

In this embodiment, the first-speed counter gear 46D is made up of a helical gear, and the lubricating oil is scooped up diagonally forward by the first-speed counter gear 46D.

Therefore, by forming a bulge 51e on the right side wall 51E of the catch tank 51, the lubricating oil O1 (see FIG. 5) scooped up by the first-speed counter gear 46D can be efficiently captured by the bulge 51e.

As shown in FIG. 5, an oil drop hole 51a is formed in the bottom wall 51A, and oil stored in the catch tank 51 is discharged from the oil drop hole 51a. The oil drop hole 51a has an opening area that is much smaller than the opening area of the opening 51F.

As a result, the amount of lubricating oil discharged from the oil pit 51a is small compared to the amount of lubricating oil introduced into the catch tank 51 from the opening 51F, and a certain amount of oil can be temporarily stored in the catch tank 51.

As shown in Figures 2 and 7, the guide portion 50C extends from the lower end portion 50b toward the upper end portion 50c, moving away from the central axis of rotation C of the first-speed counter gear 46D.

That is, as shown in FIG. 7, the guide portion 50C extends from the lower end 50b toward the upper end 50c so as to gradually move away from the rotational axis C of the first-speed counter gear 46D such that the imaginary line L2 connecting the upper end 50c to the rotational axis C of the first-speed counter gear 46D is longer than the imaginary line L1 connecting the lower end 50b to the rotational axis C of the first-speed counter gear 46D (the rotational axis C of the counter shaft 46).

As shown in Figures 2 and 7, the right side wall 51E of the catch tank 51 is located on an extension line L3 of the guide portion 50C. In this embodiment, the right side wall 51E forms the side wall of the catch tank.

In addition, since the guide portion 50C extends from the lower end portion 50b toward the upper end portion 50c so as to move away from the central axis C of rotation of the first-speed counter gear 46D, the extension line L3 of the guide portion 50C gradually moves away from the central axis C of rotation of the first-speed counter gear 46D as it moves from the guide portion 50C side of the extension line L3 toward the catch tank 51. The guide portion 50C may extend in a curved manner or in a straight line.

As shown in FIG. 7, the shielding wall portion 50B extends along the circumferential direction of the counter shaft 46 (i.e., from the counter gear 46A to the counter gear 46D), and as shown in FIG. 5, is located between the first-speed counter gear 46D and the second-speed counter gear 46C adjacent to the first-speed counter gear 46D in the axial direction of the counter shaft 46.

As shown in Figures 3 and 7, the shielding wall portion 50B is made of a curved plate that curves along the circumferential direction of the counter shaft 46.

As shown in FIG. 7, the upper edge of the shielding wall portion 50B has a top portion 50d that is located at the highest position of the upper edge, and a bottom portion 50e that is located at the lowest position. The bottom portion 50e is located above the bottom end portion 50b of the guide portion 50C.

As shown in Figures 3 and 5, multiple ribs 52A, 52B, 52C, and 52D are provided on the outer circumferential surfaces of the shaft side cover portion 50Q and the shielding wall portion 50B. Ribs 52A to 52D are provided at intervals in the circumferential direction of the shaft side cover portion 50Q and the shielding wall portion 50B, and connect the shaft side cover portion 50Q and the shielding wall portion 50B.

Ribs 52A and 52D are provided on the upper part of the shaft side cover part 50Q and the shielding wall part 50B, and extend horizontally from the shaft side cover part 50Q.

A parking lock mechanism 55 (see Figures 5 and 6) is installed in the rear case 8. As shown in any one of Figures 4 to 6, the parking lock mechanism 55 includes a parking gear 56, a parking pole 57, a parking pole shaft 58, and a parking rod 60.

The parking lock mechanism 55 also includes a manual shaft 61, a detent plate 62, and a detent spring 63.

The parking gear 56 is installed between the first-speed counter gear 46D and the counter drive gear 46E in the axial direction of the counter shaft 46.

The parking pole 57 is pivotable about the parking pole shaft 58 and can mesh with the parking gear 56.

When the parking pole 57 meshes with the parking gear 56, the rotation of the parking gear 56 is restricted, the rotation of the counter shaft 46 is restricted, and the vehicle 1 is maintained in a stopped state.

As shown in FIG. 5, the manual shaft 61 is connected to a transmission (not shown) via a lever 61A, and is rotated when the transmission swings the lever 61A. As shown in FIG. 6, the detent plate 62 is connected to the manual shaft 61, and swings when the manual shaft 61 rotates.

The rear end of the parking rod 60 is connected to the detent plate 62, and the parking rod 60 can move back and forth in its axial direction as the detent plate 62 swings.

When the parking rod 60 moves in one axial direction, it pushes up the parking pole 57, causing the parking pole 57 to mesh with the parking gear 56. When the parking rod 60 moves in the other axial direction, it lowers the parking pole 57, moving the parking pole 57 away from the parking gear 56 and disengaging the parking pole 57.

The detent spring 63 engages with a mating groove (not shown) formed in the detent plate 62 as the detent plate 62 swings, providing the driver with a shifting sensation (a so-called click sensation) when shifting.

As shown in FIG. 7, when the counter shaft 46 is viewed from the axial direction, the detent plate 62 is installed between the oil separator 50 and the catch tank 51. In other words, the detent plate 62 is installed between the oil separator 50 and the catch tank 51 in the vehicle width direction.

Specifically, as shown in FIG. 8, the detent plate 62 is arranged next to the cover portion 50A in the vehicle width direction.

The detent plate 62 is located at the same height as the oil separator 50 in the vertical direction and is installed alongside the oil separator 50 in the vehicle width direction.

The upper end 62a of the detent plate 62 is located higher than the upper end 50c of the guide portion 50C and lower than the opening 51F of the catch tank 51 (see Figure 7).

The bottom wall 51A of the catch tank 51 is located between the upper end 62a of the detent plate 62 and the upper end 50c of the guide portion 50C in the vertical direction. As shown in FIG. 8, the upper end 62a of the detent plate 62 is located higher on the guide portion 50C side (rear side) than on the front side.

As shown in FIG. 5, when the catch tank 51 is viewed from above, the rear end 62b of the detent plate 62 is located between the catch tank 51 and the upper end 50c of the guide portion 50C. The rear end 62b of the detent plate 62 constitutes a part of the detent plate 62.

At least a portion of the detent plate 62 needs to be located between the catch tank 51 and the upper end 50c of the guide portion 50C.

As shown in Figures 1 and 9, the partition wall 21B is provided with a peripheral wall portion 21W. The peripheral wall portion 21W protrudes from the partition wall 21B toward the oil separator 50 and extends in the circumferential direction of the first-speed counter gear 46D, covering the lower side of the fourth-speed counter gear 46A.

As shown in FIG. 9, a pair of fitting holes 21e, 21f are formed in the peripheral wall portion 21W, and the fitting holes 21e, 21f are spaced apart in the circumferential direction of the counter shaft 46.

As shown in FIG. 10, a pair of fitting protrusions 50f, 50g are provided on the front end surface of the oil separator 50, i.e., the front end surface of the cover portion 50A, and the fitting protrusions 50f, 50g are fitted into the fitting holes 21e, 21f of the peripheral wall portion 21W. In this way, the oil separator 50 is attached to the partition wall 21B.

In this embodiment, the fitting holes 21e and 21f form a first fitting portion, and the fitting protrusions 50f and 50g form a second fitting portion. As shown in FIG. 6, a fitting protrusion 50h is provided on the rear end surface of the guide portion 50C of the oil separator 50, and the fitting protrusion 50h fits into a fitting hole (not shown) provided in the rear case 8.

In addition, a fitting protrusion may be formed on the peripheral wall portion 21W as the first fitting portion, and a fitting hole may be formed on the oil separator 50 as the second fitting portion.

Next, the effects of the transmission 2 of this embodiment will be described.
The transmission 2 of this embodiment includes a transmission case 4 having lubricating oil O stored at the bottom thereof, and a counter shaft 46 having counter gears 46A to 46D and supported rotatably by the transmission case 4.

The transmission 2 also has an oil separator 50 that is installed along the outer peripheral surfaces of the third-speed counter gear 46B and the second-speed counter gear 46C, and a guide portion 50C that is provided on the oil separator 50 so as to be positioned radially outward of the first-speed counter gear 46D.

The transmission 2 further includes a catch tank 51 that stores the lubricating oil scooped up by the first-speed counter gear 46D. The catch tank 51 has a bottom wall 51A, a front wall 51B, a rear wall 51C, a left side wall 51D, and a right side wall 51E, and an opening 51F provided at the upper ends of the front wall 51B, the rear wall 51C, the left side wall 51D, and the right side wall 51E.

The guide portion 50C extends from the lower end 50b toward the upper end 50c, away from the central axis C of rotation of the first-speed counter gear 46D, and the right side wall 51E of the catch tank 51 is located on the extension line L3 of the guide portion 50C.

This allows the lubricating oil O2 (see FIG. 2) scooped up by the rotation of the first-speed counter gear 46D to collide with the right side wall 51E of the catch tank 51 by the guide portion 50C. Therefore, the momentum of the lubricating oil O2 colliding with the right side wall 51E guides the lubricating oil O2 along the right side wall 51E to the opening 51F, and allows it to be introduced into the catch tank 51 through the opening 51F.

Therefore, while ensuring lubricating oil for lubricating the meshing parts between the input gear 41A and the input gear 41D and the counter gear 46A and the counter gear 46D, as well as the lubricated parts such as the bearings 35A and 35B, the surplus lubricating oil can be efficiently stored in the catch tank 51 by the first-speed counter gear 46D.

This allows the oil level of the lubricating oil O stored in the bottom of the transmission case 4 to be lowered, reducing the stirring resistance of the first-speed counter gear 46D. As a result, the power transmission efficiency of the transmission 2 can be improved, and the fuel consumption of the engine 3 can be reduced.

In this way, the transmission 2 of this embodiment can reliably reduce the amount of lubricating oil O stored at the bottom of the transmission case 4, and can reduce the stirring resistance of the first-speed counter gear 46D gear.

In addition, according to the transmission 2 of this embodiment, the first-speed counter gear 46D is composed of the gear member with the largest diameter among the counter gears 46A to 46D and the counter drive gear 46E.

In addition, a notch 50a is formed in the lower part of the oil separator 50, opening from the lower end 50b in the direction in which the guide part 50C extends along the circumferential direction of the first-speed counter gear 46D.

The catch tank 51 has a cover portion 50A that covers the lower portions of the third-speed counter gear 46B and the second-speed counter gear 46C, and the lower portion of the first-speed counter gear 46D protrudes downward through a notch 50a in the oil separator 50 and is submerged in the lubricating oil O.

This allows the first-speed counter gear 46D, which has the largest diameter among the counter gears 46A to 46D, to reliably scoop up the lubricating oil O stored at the bottom of the transmission case 4 into the catch tank 51.

In addition, by covering the lower portions of the third-speed counter gear 46B, which has a smaller diameter than the first-speed counter gear 46D, and the second-speed counter gear 46C, which has a smaller diameter than the third-speed counter gear 46B, with the cover portion 50A, the third-speed counter gear 46B and the second-speed counter gear 46C can be separated from the lubricating oil O stored in the transmission case 4.

This reduces the stirring resistance of the third-speed counter gear 46B and the second-speed counter gear 46C. As a result, the power transmission efficiency of the transmission 2 can be improved more effectively, and the fuel consumption of the engine 3 can be reduced more effectively.

In the present embodiment, the oil separator 50 has a notch 50a formed at the rear end of the lower part of the oil separator 50, but an opening extending circumferentially from the lower end 50b of the guide portion 50C may be formed in a portion of the lower part of the oil separator 50 that is located forward of the rear end of the oil separator 50.

The cover portion 50A may also cover the underside of the fourth-speed counter gear 46A in addition to the third-speed counter gear 46B and the second-speed counter gear 46C.

In addition, according to the transmission 2 of this embodiment, the oil separator 50 has a shielding wall portion 50B that extends along the circumferential direction of the counter shaft 46, and the shielding wall portion 50B is located between the first-speed counter gear 46D and the second-speed counter gear 46C adjacent to the first-speed counter gear 46D in the axial direction of the counter shaft 46.

In addition, the upper edge of the shielding wall portion 50B has a top portion 50d and a bottom portion 50e, and the bottom portion 50e is located above the bottom end portion 50b of the guide portion 50C.

As a result, the lubricating oil scooped up by the rotation of the first-speed counter gear 46D can be blocked by the blocking wall portion 50B, preventing the lubricating oil from entering the cover portion 50A. This makes it possible to more effectively reduce the stirring resistance of the third-speed counter gear 46B and the second-speed counter gear 46C.

As a result, the power transmission efficiency of the transmission 2 can be improved more effectively, and the fuel consumption of the engine 3 can be reduced more effectively.

In addition, according to the transmission 2 of this embodiment, ribs 52A to 52D are provided on the outer peripheral surfaces of the shielding wall portion 50B and the cover portion 50A.

This increases the rigidity of the shaft side cover portion 50Q and the shielding wall portion 50B, thereby increasing the rigidity of the oil separator 50.

In addition, the ribs 52A and 52D are provided on the upper part of the shaft side cover part 50Q and the shielding wall part 50B and extend horizontally from the shaft side cover part 50Q, so that the ribs 52A and 52D can more effectively prevent the lubricating oil from entering the cover part 50A, and the stirring resistance of the third-speed counter gear 46B and the second-speed counter gear 46C can be more effectively reduced.

In addition, according to the transmission 2 of this embodiment, when the countershaft 46 is viewed from the axial direction, the detent plate 62 of the parking lock mechanism 55 is installed between the oil separator 50 and the catch tank 51.

The upper end 62a of the detent plate 62 is located higher than the upper end 50c of the guide portion 50C and lower than the opening 51F of the catch tank 51.

In addition, when the catch tank 51 is viewed from above, the rear end 62b of the detent plate 62 is located between the catch tank 51 and the upper end 50c of the guide portion 50C.

This allows the lubricating oil, which is scooped up by the first-speed counter gear 46D and flows vigorously through the guide portion 50C, to collide with the detent plate 62.

As a result, the droplets that collide with the detent plate 62 collide with the right side wall 51E of the catch tank 51 with great force, and the momentum of the lubricating oil guides the lubricating oil along the right side wall 51E to the opening 51F, through which it can be introduced into the catch tank 51.

As a result, a large amount of lubricating oil for the first-speed counter gear 46D can be efficiently stored in the catch tank 51. In this way, the detent plate 62 can be used as part of the guide portion 50C.

Since the detent plate 62 is configured to be able to swing freely, it is preferable that the upper end 62a of the detent plate 62 be positioned higher than the upper end 50c of the guide portion 50C and lower than the opening 51F of the catch tank 51 when the vehicle 1 is traveling.

In addition, according to the transmission 2 of this embodiment, the transmission case 4 has a partition wall 21B that rotatably supports the counter shaft 46, and the partition wall 21B has a peripheral wall portion 21W that protrudes from the partition wall 21B toward the oil separator 50 and extends in the circumferential direction of the first-speed counter gear 46D and covers the fourth-speed counter gear 46A from below.

The peripheral wall portion 21W has fitting holes 21e and 21f, and the oil separator 50 has fitting protrusions 50f and 50g that fit into the fitting holes 21e and 21f.

The oil separator 50 is then attached to the partition wall 21B by fitting the fitting holes 21e, 21f into the fitting protrusions 50f, 50g.

As a result, when the oil separator 50 is assembled to the transmission case 4, the oil separator 50 is pressed against the countershaft 46 while the fitting projections 50f, 50g of the oil separator 50 are positioned in the fitting holes 21e, 21f of the peripheral wall portion 21W. Next, the fitting projections 50f, 50g are fitted into the fitting holes 21e, 21f, thereby assembling the oil separator 50 to the transmission case 4.

At this time, by fitting the two fitting protrusions 50f, 50g into the two fitting holes 21e, 21f, the oil separator 50 can be prevented from swinging around the axis of the countershaft 46, improving the ease of assembly of the oil separator 50 to the transmission case 4.

In addition, the peripheral wall portion 21W protrudes from the partition wall 21B toward the oil separator 50 and extends in the circumferential direction of the first-speed counter gear 46D, so that the peripheral wall portion 21W can function as a rib, and the rigidity of the partition wall 21B can be increased by the peripheral wall portion 21W.

As a result, the counter shaft 46 can be supported with high rigidity on the partition wall 21B via the bearing 35B, and the axial distance between the input shaft 41 and the counter shaft 46 can be prevented from increasing due to the reaction force caused by the meshing between the input gear 41A to the input gear 41D and the counter gear 46A to the counter gear 46D. As a result, the power transmission efficiency of the transmission 2 can be prevented from decreasing.

In this embodiment, the peripheral wall portion 21W covers the lower part of the fourth-speed counter gear 46A, but by changing the shape of the oil separator 50, the peripheral wall portion 21W may cover the lower parts of the fourth-speed counter gear 46A and the third-speed counter gear 46B.

In addition, when the oil separator 50 is attached to the partition wall 21B, as shown in FIG. 5, the gap a between the guide portion 50C and the rear end face of the first-speed counter gear 46D in the axial direction of the counter shaft 46 is reduced, and the gap b between the guide portion 50C and the front end face of the first-speed counter gear 46D is increased.

This improves the workability of assembling the oil separator 50 when moving the oil separator 50 toward the partition wall 21B during the work of assembling the oil separator 50 to the transmission case 4.

Specifically, when the oil separator 50 is to be installed in the transmission case 4, the center case 7 is removed from the rear case 8, and the oil separator 50 is then attached to the partition wall 21B.

If the gap a is made smaller than the gap b when the oil separator 50 is assembled to the partition wall 21B, when the oil separator 50 is moved away from the partition wall 21B after being assembled to the partition wall 21B, the oil separator 50 can be moved away from the partition wall 21B by the gap b. This allows the fitting protrusions 50f, 50g to be removed from the fitting holes 21e, 21f.

In other words, when attaching the oil separator 50 to the partition wall 21B, the gap b is smaller than the gap a when the oil separator 50 is attached to the partition wall 21B while pressing the oil separator 50 against the counter shaft 46.

As a result, when the oil separator 50 is moved toward the partition wall 21B by the gap b, a space can be secured for fitting the fitting protrusions 50f, 50g into the fitting holes 21e, 21f. This allows the oil separator 50 to be easily assembled to the partition wall 21B, improving the workability of assembling the oil separator 50.

In addition, by making the gap a smaller than the gap b, it is possible to prevent the lubricating oil O1 from colliding with the guide portion 50C when the lubricating oil O1 is scooped up diagonally forward by the first-speed counter gear 46D. This ensures that the lubricating oil is supplied to the catch tank 51.

The power transmission device of this embodiment is applied to a transmission 2, but it goes without saying that it can be applied to devices other than transmissions as long as they are power transmission devices that have a rotating shaft and gears.

Although an embodiment of the present invention has been disclosed, it is apparent that modifications may be made by one of ordinary skill in the art without departing from the scope of the present invention. All such modifications and equivalents are intended to be included in the following claims.

2...transmission (power transmission device), 4...transmission case (case member), 21B...partition wall, 21e, 21f...fitting hole (first fitting portion), 21W...circumferential wall portion, 46...counter shaft (rotating shaft), 46A...4th-speed counter gear (gear member), 46B...3rd-speed counter gear (gear member), 46C...2nd-speed counter gear (gear member, adjacent gear member), 46D...1st-speed counter gear (gear member, specified gear member), 50...oil separator, 50A...cover portion, 50a...notch, 50B...shielding wall portion, 50b...lower end portion (lower end portion of guide portion), 50C...guide portion, 50c.. .Upper end (upper end of guide part), 50d...uppermost part, 50e...lowest part, 51...catch tank, 51E...right side wall (side wall of catch tank), 51F...opening (opening of catch tank), 51f, 51h...fitting protrusion (second fitting part), 52A, 52B, 52C, 52D...rib, 55...parking lock mechanism, 62...detent plate, 62a...upper end (upper end of detent plate), 62b...rear end (part of detent plate), C...rotation axis (rotation axis of rotation shaft), L3...extension (extension in the direction of extension of guide part), O...lubricating oil

Claims (5)

a case member having a bottom portion in which lubricating oil is stored;
a rotating shaft having a plurality of gear members and rotatably supported by the case member;
an oil separator disposed along an outer circumferential surface of the plurality of gear members;
a guide portion provided on the oil separator so as to be positioned radially outward of a predetermined gear member among the plurality of gear members;
a catch tank in which the lubricating oil scooped up by the predetermined gear member is stored,
A power transmission device, wherein the catch tank has a side wall and an opening provided at an upper end of the side wall,
the guide portion extends from a lower end portion to an upper end portion thereof so as to move away from a rotation central axis of the predetermined gear member,
The side wall of the catch tank is located on an extension line of the guide portion ,
the predetermined gear member is configured as a gear member having a largest diameter among the plurality of gear members,
a notch or an opening is formed in a lower portion of the oil separator, the notch or opening opening from a lower end portion in a direction in which the guide portion extends along a circumferential direction of the predetermined gear member,
the catch tank has a cover portion that covers a lower portion of at least one of the plurality of gear members excluding the predetermined gear member,
A power transmission device, characterized in that a lower portion of the predetermined gear member protrudes downward through the notch or the opening of the oil separator and is immersed in lubricating oil . The oil separator has a blocking wall portion extending along a circumferential direction of the rotating shaft,
the blocking wall portion is located between the predetermined gear member and an adjacent gear member adjacent to the predetermined gear member in an axial direction of the rotation shaft,
The upper edge of the shielding wall portion has a top portion and a bottom portion,
2. The power transmission device according to claim 1 , wherein the lowermost portion is located above a lower end portion of the guide portion . 3. The power transmission device according to claim 2, wherein at least one rib is provided on an outer peripheral surface of the blocking wall portion and the cover portion . When the rotating shaft is viewed from the axial direction, a detent plate of a parking lock mechanism is installed between the oil separator and the catch tank,
An upper end of the detent plate is located at a position higher than an upper end of the guide portion and lower than the opening of the catch tank,
4. A power transmission device according to claim 1, wherein when the catch tank is viewed from above, at least a portion of the detent plate is located between the catch tank and an upper end of the guide portion . the case member has a partition wall that rotatably supports the rotation shaft,
the partition wall has a peripheral wall portion that protrudes from the partition wall toward the oil separator, extends in a circumferential direction of the plurality of gear members, and covers a lower portion of at least one of the plurality of gear members,
A first fitting portion is formed on the peripheral wall portion,
a second fitting portion that is fitted into the first fitting portion is formed in the oil separator,
5. The power transmission device according to claim 1 , wherein the oil separator is attached to the partition wall by fitting the first fitting portion and the second fitting portion together .

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