CN211231537U - Oil groove of transmission - Google Patents

Abstract

An oil groove of a transmission capable of optimizing a flow state of a lubricating oil or improving lubricating performance with a simple and space-saving configuration is obtained. The utility model discloses an oil groove (9) of derailleur constitute by the diapire and for the diapire to the oil circuit that the outstanding lateral wall of top of the body encircleed, have: a trap section (90) for collecting the lubricating oil carried up from the lower section of the transmission; and a supply end portion (95) that supplies lubricating oil to a shaft end of a transmission shaft (3) that supports the transmission gear, wherein intermediate reservoir portions (93a, 91) are provided between the collection portion and the supply end portion, and bottom walls (93c, 91b) of the intermediate reservoir portions are located below a 1 st bottom wall portion (90a) that is a bottom wall of the collection portion and a 2 nd bottom wall portion (95a) that is a bottom wall of the supply end portion. The oil groove has a through portion (96) that penetrates in the vertical direction, and a part of a shift device (7) that transmits a shift operation of the transmission is located in the through portion.

Description

Oil groove of transmission

Technical Field

The utility model relates to a constitute lubricating structure's of derailleur oil groove.

Background

In a transmission provided in a vehicle or the like, a lubrication structure is known in which lubricating oil stored in a lower portion of a transmission case is lifted upward by an operation of a gear or the like, and the lubricating oil scattered and flowing in the transmission case is collected by an oil groove (oil setter) and supplied to a lubricated portion. The oil groove is disposed above the inside of the transmission and has an eaves-gutter-shaped oil passage for guiding the lubricating oil to a lubricated part.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2011-

SUMMERY OF THE UTILITY MODEL

Problem to be solved by utility model

In the transmission, the lubricating oil is carried by the rotation of the gears immersed in the lubricating oil (oil reservoir) stored therebelow. In the stopped state or non-running state of the engine, since the gear does not rotate, the lubricating oil collects downward, and the amount of the lubricating oil present in the oil reservoir increases. When the gear is rotated by running or driving the engine, the lubricating oil circulates in the transmission, the amount of the lubricating oil present in the oil reservoir decreases, and the liquid level of the lubricating oil decreases. In consideration of initial lubrication when starting running from a stopped state immediately after the engine is started, the amount of lubricating oil in the transmission is set to be large so that the portion requiring minimum lubrication is in the lubricating oil below the liquid level of the lubricating oil. However, if the amount of lubricating oil is set to this amount, the lubricating oil may be excessive during running in which the lubricating oil is distributed in the transmission, and the stirring resistance during rotation of the gears may be unnecessarily increased due to the viscosity of the lubricating oil or the like. As a result, the driving efficiency may be reduced, and the fuel efficiency may be deteriorated.

In order to reduce the stirring resistance and to make the amount of lubricating oil appropriate, a technique is known in which a catch tank (catch tank) capable of storing lubricating oil is provided separately from a lower oil reservoir in the transmission. The collecting tank has the following functions: excess lubricating oil scattered or flowing in the transmission case during engine driving or traveling is received and temporarily accumulated, and the amount of lubricating oil contacting (stirred by) gears or the like is adjusted to an appropriate amount.

In the conventional lubricating structure of the transmission, the canister as described above is provided separately. However, the provision of a separate collection tank is restricted in terms of installation space or cost. In particular, the catch tank is a member that traps the lubricating oil above the lower layer portion in the transmission, as in the oil groove, and it is difficult to add the catch tank to the lubricating structure having the oil groove in some cases, depending on the layout inside the transmission, because the capacity for temporarily storing the lubricating oil is to be ensured.

Further, the structure of the transmission is complicated, and it is sometimes difficult to supply the lubricating oil to a specific lubricated part with the conventional oil groove. In particular, in a manual transmission type transmission, a shifting device that transmits a shift operation of an occupant to a transmission gear mechanism is provided in an upper portion of the transmission. Therefore, the shift device partially occupies an upper space inside the transmission, and the degree of freedom in the arrangement or shape of the oil groove is sometimes restricted.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an oil groove of a transmission, which can optimize a flowing state of a lubricating oil or improve lubricating performance with a simple and space-saving configuration.

Means for solving the problems

The utility model relates to an oil groove of derailleur constitutes by the diapire and for the diapire to the oil circuit that the outstanding lateral wall of top of the body encircleed, has: a trap portion for collecting the lubricating oil carried up from the lower portion of the transmission; and a supply end portion that supplies lubricating oil to a shaft end of a speed change shaft that supports the speed change gear, the oil groove of the transmission being characterized by having an intermediate reservoir portion between the trap portion and the supply end portion, a bottom wall of the intermediate reservoir portion being positioned lower than a 1 st bottom wall portion and a 2 nd bottom wall portion, the 1 st bottom wall portion being a bottom wall of the trap portion, the 2 nd bottom wall portion being a bottom wall of the supply end portion.

In addition, the present invention provides an oil groove of a transmission, which constitutes an oil path surrounded by a bottom wall and a side wall protruding upward relative to the bottom wall, and which includes: a trap portion for collecting the lubricating oil carried up from the lower portion of the transmission; and a supply end portion that supplies lubricating oil to a shaft end of a speed change shaft that supports the speed change gear, the oil groove of the transmission being characterized by having a through portion that penetrates in the up-down direction, a part of a shifting device that transmits a speed change operation of the transmission being located in the through portion.

Effect of the utility model

According to the present invention, the oil groove of the transmission can be obtained that can optimize the circulation state of the lubricating oil or improve the lubricating performance with a simple and space-saving configuration.

Drawings

Fig. 1 is a plan view of the transmission of the present embodiment.

Fig. 2 is a side view of the transmission with the left case removed and viewed from the left.

Fig. 3 is a side view of the transmission with the right housing removed and viewed from the right.

Fig. 4 is a side view of the right housing and the oil groove as viewed from the left.

Fig. 5 is a side view of the left housing and the oil groove as viewed from the right.

Fig. 6 is a side view of the left housing as viewed from the right.

Fig. 7 is a sectional view taken along line a-a of fig. 1.

Fig. 8 is a sectional view taken along line B-B of fig. 1.

Fig. 9 is a sectional view taken along line C-C of fig. 1.

Fig. 10 is a sectional view taken along line D-D of fig. 2.

Fig. 11 is a view of the internal shift mechanism, the speed change gear mechanism, and the oil groove as viewed from above.

Fig. 12 is a view of the transmission gear mechanism and the oil groove as viewed from above.

Fig. 13 is a view of the transmission gear mechanism and the oil groove as viewed from below.

Fig. 14 is a front perspective view of the oil groove.

Fig. 15 is a rear perspective view of the oil groove.

Fig. 16 is a front view of the oil groove.

Description of the reference numerals

1: engine

2: speed variator

3: input shaft (speed changing shaft)

4: intermediate shaft (speed changing shaft)

5: reverse gear shaft (speed changing shaft)

6: differential gear

7: gear shifting device

8: internal shifting mechanism

9: oil groove

10: speed change gear mechanism

20: transmission housing

30: input gear 1 (speed change gear)

31: no. 2 input gear (speed change gear)

32: 3 rd input gear (speed change gear)

33: 4 th input gear (speed change gear)

34: 5 th input gear (speed change gear)

35: input gear for reverse gear (speed change gear)

36: 2 nd shift sleeve

37: 3 rd shift sleeve

40: 1 st intermediate gear (speed change gear)

41: 2 nd intermediate gear (speed change gear)

42: 3 rd intermediate gear (speed change gear)

43: 4 th intermediate gear (speed change gear)

44: 5 th intermediate gear (speed change gear)

45: last-stage transmission gear

46: 1 st Shift Sleeve

47: intermediate gear for reverse gear (speed change gear)

50: reverse gear idler wheel (speed change gear)

60: last-stage driven gear

70: gear shifting selection shaft

81: 1 st Shift Unit

81 a: 1 st Shift shaft

81 b: no. 1 shift fork

81 c: 1 st shift fork

82: 2 nd shift unit

82 a: 2 nd shift shaft

82 b: 2 nd speed change fork

82 c: 2 nd shift fork of shifting

83: 3 rd Shift Unit

83 a: 3 rd shift shaft

83 b: 3 rd speed change fork

83 c: 3 rd shifting fork

90: collecting part

90 a: bottom wall (1 st bottom wall)

91: inflow part (middle storage part)

91 j: gap

92: no. 1 oil path

93: no. 2 oil path

93 a: oil collection tank (middle storage)

93 b: front oil path part

93 c: lower bottom wall part (No. 3 bottom wall part)

93 d: curved bottom wall (arc part)

93 f: transitional bottom wall (arc part)

93 i: inclined part (inclined plane)

94: confluence part

94 a: upper section bottom wall part (arc part)

95: supply end

95 a: bottom wall (No. 2 bottom wall)

96: penetration part

100: dripping hole

101: dripping hole

102: dripping hole

103: dripping hole

104: dripping hole

105: a discharge orifice.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings and the description, the vertical, front, rear, left, and right directions refer to the front, rear, left, right, and vertical directions in a state where a transmission is mounted in a vehicle, not shown. In addition, the left-right direction of the vehicle is also expressed as the vehicle width direction. In the following drawings, for convenience of explanation, some components are omitted.

A schematic configuration of a manual transmission for a vehicle according to the present embodiment will be described with reference to the drawings. The vehicle according to the present embodiment is a so-called FF (front-drive) type four-wheel vehicle in which front wheels are driven by an engine mounted on a front portion of a vehicle body. As shown in fig. 1, the engine 1 and the transmission 2 are arranged in a left-right arrangement in the front portion of the vehicle body, the engine 1 being located on the right side, and the transmission 2 being located on the left side of the engine 1.

The engine 1 is an internal combustion engine such as a gasoline engine, for example, and various components such as a crankshaft (not shown) are housed in an engine case (not shown). The axial direction of the crankshaft is oriented in the vehicle width direction (left-right direction). The engine 1 is not limited to a gasoline engine, and may be another type of engine such as a diesel engine.

The transmission 2 is a so-called stepped manual transmission that is shifted by a manual operation of an occupant. Further, the stepped manual transmission may be a stepped transmission in which a shift operation is performed using an actuator instead of a manual operation by an occupant. The transmission 2 performs a step-variable speed change (reduction) of the rotation of the crankshaft by the transmission gear mechanism 10 and transmits the rotation to a drive wheel (not shown). The transmission 2 is configured by assembling various components in a transmission case 20. Examples of the various components include a clutch (not shown), various shafts and a plurality of speed change gears constituting the speed change gear mechanism 10, the shift device 7, the internal shift mechanism 8, and the like.

As shown in fig. 1, the transmission case 20 is divided into a right case 21 and a left case 22 in the right-left direction. The right case 21 forms a right space (clutch arrangement space) of the transmission case 20, and the left case 22 forms a left space (arrangement space of the transmission gear mechanism 10) of the transmission case 20 together with the right case 21. The right case 21 has a partition wall 23 (see fig. 4, 8, and 10) that partitions a space in the transmission case 20 to the left and right (the left space and the right space described above). The left housing 22 has: a left end wall 25 closing the left end side; and a peripheral wall 24 extending rightward from the peripheral edge of the left end wall 25 toward the partition wall 23 (see fig. 10). The left space is defined by a peripheral wall 24 of the left housing 22, a left end wall 25, and a partition wall 23 of the right housing 21.

As shown in fig. 3, the peripheral wall 24 of the left housing 22 has: an upper wall portion 24a located at the front upper portion; a front wall portion 24b extending downward from a front end portion of the upper wall portion 24 a; a rear wall portion 24c extending downward from a rear end portion of the upper wall portion 24 a; and a bottom wall portion 24d connecting lower portions of the front wall portion 24b and the rear wall portion 24 c.

The right case 21 and the left case 22 are configured as a transmission case 20 by aligning the mating surfaces 21a and 22a and fastening them with a plurality of bolts (not shown). In the left housing 22, an end face of the peripheral wall 24 forms an engaging face 22 a. An engine housing (crankcase) is fastened to the right side of the right housing 21.

As shown in fig. 10, the right housing 21 has a peripheral wall protruding leftward from the peripheral edge of the partition wall 23, and the end face of the peripheral wall forms an engaging surface 21 a. In a state where the right and left cases 21 and 22 are combined, the peripheral wall of the right case 21 and the peripheral wall 24 of the left case 22 are continuous to form a peripheral wall of the arrangement space of the transmission gear mechanism 10. For convenience of explanation, hereinafter, the peripheral wall 24 includes the peripheral wall of the right housing 21 and the peripheral wall 24 of the left housing 22 without limitation of the housings. Therefore, in fig. 2, 4, and 8, the peripheral wall (peripheral wall, upper wall, front wall, rear wall, and bottom wall) of the right housing 21 is denoted by the same reference numerals (24, 24a, 24b, 24c, and 24d) as the peripheral wall 24 of the left housing 22.

A clutch (not shown) disposed coaxially with the crankshaft is provided in the right housing 21 (right space) on the right side of the partition wall 23. Further, the input shaft 3, the intermediate shaft 4, and the reverse shaft 5 are disposed as shift shafts constituting the transmission gear mechanism 10 in the left case 22 (left space) on the left side of the partition wall 23 (see fig. 2, 3, and 11 to 13). These shift shafts are arranged in the vehicle width direction in the same manner as the crankshaft.

The input shaft 3 is a shaft to which power from the engine 1 is input via a clutch. The input shaft 3 is disposed coaxially with the crankshaft. As shown in fig. 2 and 3, the input shaft 3 is disposed slightly forward and upward of the center in the transmission case 20 in side view. As shown in fig. 12 and 13, a bearing 3a and a bearing 3b are attached to the input shaft 3. The input shaft 3 is supported by a partition wall 23 of the right housing 21 and a left end wall 25 of the left housing 22 via a bearing 3a and a bearing 3b, and is rotatable around the shaft. A support recess 110 (see fig. 4) for holding the bearing 3a is formed in the partition wall 23 of the right housing 21, and a support recess 111 (see fig. 5 and 6) for holding the bearing 3b is formed in the left end wall 25 of the left housing 22. A through hole 110a penetrating the partition wall 23 is formed in the center of the support recess 110. The input shaft 3 is inserted into the through hole 110a, and a right end of the input shaft 3 protrudes into the right housing 21 (right space) through the through hole 110a (see fig. 10). A clutch (not shown) is attached to the right end of the input shaft 3.

On the input shaft 3, in order from the right side: the 1 st input gear 30, the 2 nd input gear 31, the 3 rd input gear 32, the 4 th input gear 33, and the 5 th input gear 34 (see fig. 11 to 13). Of these input gears, the 1 st input gear 30 has the smallest diameter, and the diameters become larger in the order of the 2 nd input gear 31, the 3 rd input gear 32, the 4 th input gear 33, and the 5 th input gear 34. Further, the input gear may also be referred to as a drive gear. A reverse input gear 35 is supported on the input shaft 3 between the 1 st input gear 30 and the 2 nd input gear 31.

The 1 st input gear 30, the 2 nd input gear 31, and the reverse input gear 35 are gears that rotate integrally with the input shaft 3. The 3 rd input gear 32, the 4 th input gear 33, and the 5 th input gear 34 are idle gears supported by the input shaft 3 and rotatable relative to the input shaft 3, and rotate together with the input shaft 3 when shift sleeves (a 2 nd shift sleeve 36 and a 3 rd shift sleeve 37) described later are engaged.

As shown in fig. 2 and 3, an intermediate shaft 4 is disposed behind and slightly below the input shaft 3. As shown in fig. 12 and 13, a bearing 4a and a bearing 4b are attached to the intermediate shaft 4. The intermediate shaft 4 is supported by a partition wall 23 of the right housing 21 and a left end wall 25 of the left housing 22 via a bearing 4a and a bearing 4b, and is rotatable around the shaft. A support recess 112 (see fig. 4) for holding the bearing 4a is formed in the partition wall 23 of the right housing 21, and a support recess 113 (see fig. 5 and 6) for holding the bearing 4b is formed in the left end wall 25 of the left housing 22.

On the intermediate shaft 4 are supported in order from the right: the 1 st intermediate gear 40, the 2 nd intermediate gear 41, the 3 rd intermediate gear 42, the 4 th intermediate gear 43, and the 5 th intermediate gear 44 (see fig. 11 to 13). Of these intermediate gears, the 1 st intermediate gear 40 has the largest diameter, and the diameters thereof are gradually reduced in the order of the 2 nd intermediate gear 41, the 3 rd intermediate gear 42, the 4 th intermediate gear 43, and the 5 th intermediate gear 44. Further, the intermediate gear may also be referred to as a driven gear. The 1 st intermediate gear 40 and the 1 st input gear 30, the 2 nd intermediate gear 41 and the 2 nd input gear 31, the 3 rd intermediate gear 42 and the 3 rd input gear 32, the 4 th intermediate gear 43 and the 4 th input gear 33, and the 5 th intermediate gear 44 and the 5 th input gear 34 are meshed with each other, and constitute the respective gear stages of 1 st, 2 nd, 3 rd, 4 th, and 5 th gears. A final stage drive gear 45 meshing with the final stage driven gear 60 is also supported on the counter shaft 4 on the right side of the 1 st intermediate gear 40.

The 3 rd intermediate gear 42, the 4 th intermediate gear 43, the 5 th intermediate gear 44, and the final stage transmission gear 45 are gears that rotate integrally with the counter shaft 4. The 1 st intermediate gear 40 and the 2 nd intermediate gear 41 are idle gears supported by the intermediate shaft 4 and rotatable relative to the intermediate shaft 4, and rotate together with the intermediate shaft 4 when a shift sleeve (1 st shift sleeve 46) described later is engaged.

As shown in fig. 2 and 3, a reverse shaft 5 is disposed slightly forward and downward of the input shaft 3. The right end portion of the reverse shaft 5 is inserted into a support recess 114 (see fig. 4) formed in the partition wall 23 of the right housing 21. A screw hole 5a (see fig. 13) directed in the radial direction is formed in the left end portion of the reverse shaft 5, and a bolt 115 (see fig. 5 and 6) for fastening is screwed into the screw hole 5a from the outside of the left housing 22. Since the screw hole 5a and the bolt 115 are tightened, the reverse shaft 5 is fixed to the left housing 22, and its axial movement and rotation about the shaft are restricted. A reverse idler gear 50 (see fig. 13) is supported by the reverse shaft 5. The reverse idler gear 50 is an idler gear supported by the reverse shaft 5 and rotatable relative to the reverse shaft 5, and is movable in the axial direction of the reverse shaft 5.

A reverse drive lever 51 (see fig. 11 to 13) is provided to move the reverse idler gear 50 along the reverse shaft 5. The reverse drive lever 51 is pivotally supported by a bracket 52 fixed in the transmission case 20, and has 2 arm portions bifurcated from the pivotally supporting portion. The reverse drive lever 51 has one arm portion having a distal end engaged with a groove formed in the reverse idler gear 50, and the other arm portion having a communication hole 51a formed therein. The reverse idler gear 50 moves in the axial direction of the reverse shaft 5 in accordance with the rotation (oscillation) of the reverse drive lever 51. By the movement of the reverse idle gear 50 in the axial direction of the reverse shaft 5, the reverse idle gear 50 meshes with the reverse input gear 35 of the input shaft 3 and a reverse intermediate gear 47 formed in a 1 st shift sleeve 46 described later, and the reverse idle gear 50 reverses the rotation of the input shaft 3 and transmits the rotation to the intermediate shaft 4. Further, a tip end of a reverse operation arm 83d described later is inserted into the communication hole 51a of the other arm portion of the reverse drive lever 51.

As shown in fig. 11 to 13, a synchronizer (including a shift sleeve) is disposed at a predetermined position on each of the input shaft 3 and the intermediate shaft 4. On the counter shaft 4, a 1 st shift sleeve 46 is disposed between the 1 st intermediate gear 40 and the 2 nd intermediate gear 41. A reverse intermediate gear 47 integrated with the 1 st shift sleeve 46 is provided on a side portion of the 1 st shift sleeve 46. The 2 nd shift sleeve 36 is disposed between the 3 rd input gear 32 and the 4 th input gear 33 on the input shaft 3, and the 3 rd shift sleeve 37 is disposed on the left side of the 5 th input gear 34.

The 1 st shift sleeve 46 is mounted to the intermediate shaft 4 via a hub (hub; not shown) and supported by the intermediate shaft 4, rotates integrally with the intermediate shaft 4, and is slidable in the axial direction of the intermediate shaft 4. The 2 nd shift sleeve 36 and the 3 rd shift sleeve 37 are attached to the input shaft 3 via hubs (not shown), are supported by the input shaft 3, and rotate integrally with the input shaft 3 and are slidable in the axial direction of the input shaft 3.

As will be described in detail later, predetermined shift sleeves 36, 37, 46 or reverse idle gear 50 slide in the axial direction in accordance with a shift operation by the occupant, and the input gear and the intermediate gear pair that transmit rotation between the input shaft 3 and the intermediate shaft 4 are switched to shift gears.

A differential device 6 (see fig. 2, 3, and 11 to 13) is provided behind and below the intermediate shaft 4, and the differential device 6 is a differential gear device that transmits the driving force from the intermediate shaft 4 to two wheels (driving wheels). The differential device 6 includes: a differential case 61 in which a differential gear is built; and a final stage driven gear 60 fixed to the differential case 61. The rotation axis of the final driven gear 60 is arranged along the vehicle width direction. The final driven gear 60 has a larger diameter than the gears supported by the input shaft 3, the counter shaft 4, and the reverse shaft 5, and is disposed rearward of the lower portion in the transmission case 20 in a side view. The final driven gear 60 is disposed at a position close to the left side surface of the partition wall 23 in the vehicle width direction (see fig. 10).

Further, as shown in fig. 1, the farther to the left, the smaller the transmission case 20. Therefore, the cross-sectional shape of the peripheral wall 24 of the transmission case 20 changes according to the position in the left-right direction. For example, as shown in fig. 3 to 6, in a portion near the partition wall 23, the rear wall portion 24c and the bottom wall portion 24d bulge out rearward and downward, forming a space for accommodating the final driven gear 60. In contrast, at a position (fig. 7) apart leftward from the partition wall 23, there is no bulging portion in the peripheral wall 24 that accommodates the rear lower portion of the final driven gear 60.

The internal shift mechanism 8 is disposed above the transmission gear mechanism 10 on the left side of the partition wall 23 (see fig. 2 and 3). A shift device 7 is disposed behind the internal shift mechanism 8. That is, the shift device 7 is disposed rearward of the input shaft 3 and the intermediate shaft 4 in the front-rear direction. Then, the speed change operation of the occupant is transmitted to the shift device 7, and the internal shift mechanism 8 is operated via the shift device 7, thereby changing the gear pair of the speed change gear mechanism 10 that transmits the driving force between the input shaft 3 and the intermediate shaft 4.

The shift device 7 includes: a shift select shaft 70 inserted into the left housing 22 and having an axial direction directed in the up-down direction; and a shift case 71 supporting the shift select shaft 70. The left housing 22 is formed with an opening 26 (fig. 7) that penetrates the upper wall portion 24a of the peripheral wall 24 in the vertical direction. The shift box 71 includes: a lid portion 71a positioned on the upper surface side of the left case 22 and closing the opening 26; an upper protruding portion 71b protruding upward from the cover portion 71 a; and a hanging portion 71c that protrudes downward from the cover portion 71a and is inserted into the left housing 22.

As shown in fig. 7, shift select shaft 70 is inserted into a shaft hole formed in shift case 71 with the axis line oriented in the up-down direction, and shift select shaft 70 is supported by shift case 71 and is movable in the axial direction (select direction) and rotatable about the axis (shift direction). An upper end portion of the shift select shaft 70 projects upward from an upper projecting portion 71b, and a base end portion 72a of a shift outer lever 72 is fixed to the projecting portion. As shown in fig. 7, the base end portion 72a has: a cylindrical portion into which an upper end portion of the shift select shaft 70 is inserted and fixed; and a pair of plate-like portions supported by the cylindrical portion and spaced apart in the vertical direction. The shift outer lever 72 swings together with the shift select shaft 70 centering on the axis of the shift select shaft 70. An engaging portion 73a of the selection outer lever 73 is engaged with a base end portion 72a of the shift outer lever 72. The selection outer lever 73 is pivotally supported by the shift case 71 and is swingable about a shaft 73b perpendicular to the vertical direction. The engaging portion 73a is provided eccentrically from the shaft 73b, and the engaging portion 73a is inserted between a pair of plate-like portions of the base end portion 72 a. When the selection outer lever 73 swings about the shaft 73b, the engagement portion 73a moves in the vertical direction, the movement of the engagement portion 73a is transmitted to the base end portion 72a, and the shift outer lever 72 and the shift selection shaft 70 move in the vertical direction. The lower portion of the shift select shaft 70 passes through the opening 26 and is inserted into the left housing 22.

A shaft support portion 29 (see fig. 6 and 7) is provided in front of the rear wall portion 24c in the left housing 22. The shaft support portion 29 has a hole penetrating in the vertical direction, and the lower end portion of the shift select shaft 70 is inserted into the hole to support the lower end portion of the shift select shaft 70. The shaft supporting portion 29 allows axial (selection direction) movement and rotation of the shift select shaft 70 about an axis (shift direction).

One end of a shift cable, not shown, is connected to a distal end side of the shift outer lever 72, which is remote from the base end portion 72 a. The other end of the shift cable is coupled to a shift lever (not shown) operated by the occupant. One end of an unillustrated selection cable is connected to the distal end side of the engagement portion 73a or the shaft 73b of the selection outer lever 73. The other end of the selection cable is linked to the shift lever described above.

When the shift lever is operated in the selection direction by the occupant, the selection outer lever 73 moves the shift selection shaft 70 in the axial direction (selection direction) via the shift outer lever 72. On the other hand, when the shift lever is operated in the shifting direction by the occupant, the shift outer lever 72 swings and rotates the shift selection shaft 70 around the shaft (shifting direction). Such an operation of the shift lever in the selection direction by the occupant is referred to as a selection operation, and an operation of the shift lever in the shift direction is referred to as a shift operation.

The shift device 7 of the present embodiment is an example of a remote control type shift device that remotely transmits an operation force to the shift outer lever 72 and the select outer lever 73 via a cable, but is not limited thereto and can be appropriately modified. For example, the shift device 7 may be configured as a so-called direct control type shift device in which a shift lever is directly attached to the shift select shaft 70.

A cam member 74 (see fig. 7) is provided at a portion of the shift select shaft 70 that is inserted into the left housing 22. The cam member 74 is fixed relative to the shift select shaft 70, and the cam member 74 moves in the axial direction or rotates around the shaft together with the shift select shaft 70 in accordance with a shift operation or a select operation by an occupant. A finger 74a is provided on the outer peripheral portion of the cam member 74.

Further, as shown in fig. 7, an interlock plate 77 is provided on the shift select shaft 70, and the interlock plate 77 covers the upper, lower, and front of the cam member 74. The interlock plate 77 has: an upper side plate 77a positioned above the cam member 74 and having a tip end portion bent downward; and a lower side plate 77b located below the cam member 74 and having a front end portion bent upward. The top ends of the bent portions of the upper and lower side plates 77a and 77b are vertically separated to form slits 77 c. The finger 74a of the cam member 74 protrudes forward of the interlock plate 77 through the slit 77 c.

The interlock plate 77 is restricted from moving relative to the shift select shaft 70 in the axial direction by a snap ring (not shown), and moves in the vertical direction together with the shift select shaft 70. Further, the interlock plate 77 is fitted in a recess formed in the hanging portion 71c of the shift case 71, and the rotation of the shift select shaft 70 about the shaft is restricted (see fig. 10). The interlock plate 77 has a through hole through which the shift select shaft 70 is relatively rotatably inserted. That is, the interlock plate 77 moves in the axial direction (the selection direction) together with the shift selection shaft 70, but does not follow the rotation of the shift selection shaft 70 around the shaft (the shift direction).

A shift guide 78 (see fig. 2 and 7) is provided above the interlock plate 77. The shift guide 78 is fixed to the shift select shaft 70, and moves in the up-down direction (select direction) and moves around the shaft (shift direction) together with the shift select shaft 70.

A guide groove (not shown) is formed on the outer peripheral surface of the shift guide 78 along the shape of the shift operation pattern. The guide groove includes: the horizontal groove is provided with 3 rows of upper and lower rows; and vertical slots extending up and down through the center of each horizontal slot. The tip end of a guide pin (not shown) provided in the hanging portion 71c of the shift case 71 is inserted into the guide groove. The guide pin moves along the guide groove as the shift select shaft 70 moves in the up-down direction (select direction) and rotates in the shift direction. The horizontal groove of the guide groove corresponds to the gear shifting direction, and the vertical groove corresponds to the selection direction. By bringing the guide pin into contact with the wall surface of the guide groove, the range and amount of movement of the shift select shaft 70 are limited, and rattling of the shift select shaft 70 is prevented.

A cam surface (not shown) is formed on the outer peripheral portion of the cam member 74 at a position different from the finger portion 74 a. A plunger 75 (see fig. 10) is provided at a position facing the cam surface of the cam member 74. The plunger 75 has a fitting portion that is movable in a direction orthogonal to the axial direction of the shift select shaft 70 in a cylindrical portion supported by the interlock plate 77, and the fitting portion is biased in a direction of abutting against the cam surface. By fitting the fitting portion of the plunger 75 to the cam surface of the cam member 74, a predetermined resistance force can be applied to the shift select shaft 70 during operation, and the position of the cam member 74 in the shift direction can be maintained.

The internal shift mechanism 8 moves a predetermined shift sleeve in the axial direction in accordance with the movement (rotation) of the shift select shaft 70 in the shift direction. The internal shift mechanism 8 includes a 1 st shift unit 81, a 2 nd shift unit 82, and a 3 rd shift unit 83 (see fig. 10 and 11).

The 1 st shifting unit 81 is used to move the 1 st shifting sleeve 46 in the axial direction of the countershaft 4. The 1 st shift unit 81 has: a 1 st shift shaft (shift craft) 81a extending in the left-right direction above the intermediate shaft 4; a 1 st shift fork (shift yoke)81b engageable with the finger 74a of the cam member 74; and a 1 st shift fork (shift fork)81c that engages with the 1 st shift sleeve 46.

The 1 st shift shaft 81a has an axial direction parallel to the axial directions of the input shaft 3, the intermediate shaft 4, and the reverse shaft 5. Both ends of the 1 st shift shaft 81a are supported by a shaft guide hole 120 (see fig. 4) formed in the partition wall 23 of the right case 21 and a shaft guide hole 121 (see fig. 5 and 6) formed in the left end wall 25 of the left case 22 so as to be slidable in the axial direction (the left-right direction).

The 1 st shift fork 81b is a plate-like body having an extension in the horizontal direction, and a distal end portion thereof is coupled to the 1 st shift shaft 81a (see fig. 2, 3, and 7). A recess that opens rearward is formed at the rear end of the 1 st shift fork 81 b. The finger 74a of the cam member 74 or the tip of the curved portion of the upper side plate 77a is disposed in the recess. When the position of the finger 74a in the vertical direction matches the height position of the 1 st shift fork 81b, the finger 74a is positioned in the recessed portion of the 1 st shift fork 81b and can engage therewith.

The 1 st shift fork 81C is a plate-like body having a C-shape in side view with a bifurcated tip portion. The base end portion of the 1 st shift fork 81c is coupled to the 1 st shift shaft 81a, and the tip end portion of the 1 st shift fork 81c engages with a groove formed in the 1 st shift collar 46.

The 1 st shift unit 81 is an integral structure in which a 1 st shift shaft 81a, a 1 st shift fork 81b, and a 1 st shift fork 81c are coupled, and when the shift direction movement of the finger 74a is transmitted to the 1 st shift fork 81b, the 1 st shift shaft 81a slides in the axial direction. The 1 st shift fork 81c moves the 1 st shift sleeve 46 in the axial direction of the intermediate shaft 4 by the sliding movement of the 1 st shift shaft 81a, and the engagement relationship between the 1 st intermediate gear 40 and the 2 nd intermediate gear 41 adjacent to the 1 st shift sleeve 46 is switched. Specifically, the 1 st shift unit 81 has a neutral position in which the 1 st shift sleeve 46 does not engage with either of the 1 st intermediate gear 40 and the 2 nd intermediate gear 41. Further, when the 1 st shift unit 81 is slid rightward from the neutral position, the 1 st shift sleeve 46 engages with the 1 st intermediate gear 40, and when the 1 st shift unit 81 is slid leftward from the neutral position, the 1 st shift sleeve 46 engages with the 2 nd intermediate gear 41.

When the 1 st shift sleeve 46 is engaged with the 1 st intermediate gear 40, the 1 st intermediate gear 40 rotates integrally with the counter shaft 4. Then, the rotation of the input shaft 3 is transmitted to the counter shaft 4 via the 1 st input gear 30 to the 1 st counter gear 40. This state is the gear ratio of 1 st gear in the transmission gear mechanism 10.

When the 1 st shift sleeve 46 is engaged with the 2 nd intermediate gear 41, the 2 nd intermediate gear 41 rotates integrally with the counter shaft 4. Then, the rotation of the input shaft 3 is transmitted to the counter shaft 4 via the 2 nd input gear 31 to the 2 nd counter gear 41. This state is the gear ratio of 2 th gear in the transmission gear mechanism 10.

The 2 nd shift element 82 is used to move the 2 nd shift sleeve 36 in the axial direction of the input shaft 3. The 2 nd shift unit 82 has: a 2 nd shift shaft 82a extending in the left-right direction in front of the 1 st shift shaft 81 a; a 2 nd shift fork 82b engageable with the finger 74a of the cam member 74; and a 2 nd shift fork 82c that engages with the 2 nd shift sleeve 36.

The 2 nd shift shaft 82a has an axial direction parallel to the axial directions of the input shaft 3, the intermediate shaft 4, and the reverse shaft 5. Both ends of the 2 nd shift shaft 82a are supported by a shaft guide hole 122 (see fig. 4) formed in the partition wall 23 of the right case 21 and a shaft guide hole 123 (see fig. 5 and 6) formed in the left end wall 25 of the left case 22 and are slidable in the axial direction (the left-right direction).

The 2 nd shift fork 82b is a plate-like body having an extension in the horizontal direction, and a distal end portion thereof is coupled to the 2 nd shift shaft 82a (see fig. 2, 3, and 7). A recess that opens rearward is formed in the rear end portion of the 2 nd shift fork 82b, and the finger 74a of the cam member 74, the distal end of the curved portion of the upper plate 77a, or the distal end of the curved portion of the lower plate 77b is disposed in the recess. When the position of the finger 74a in the vertical direction matches the height position of the 2 nd shift fork 82b, the finger 74a is positioned in the recessed portion of the 2 nd shift fork 82b and can engage therewith.

The 2 nd shift fork 82C is a plate-like body having a C-shape in side view with a bifurcated tip portion. A base end portion of the 2 nd shift fork 82c is coupled to the 2 nd shift shaft 82a, and a tip end portion of the 2 nd shift fork 82c engages with a groove formed in the 2 nd shift collar 36.

The 2 nd shift unit 82 is an integral structure in which a 2 nd shift shaft 82a, a 2 nd shift fork 82b, and a 2 nd shift fork 82c are coupled, and when the shift direction movement of the finger 74a is transmitted to the 2 nd shift fork 82b, the 2 nd shift shaft 82a slides in the axial direction. By sliding the 2 nd shift shaft 82a, the 2 nd shift fork 82c moves the 2 nd shift sleeve 36 in the axial direction of the input shaft 3, and the engagement relationship between the 3 rd input gear 32 and the 4 th input gear 33 adjacent to the 2 nd shift sleeve 36 is switched. Specifically, the 2 nd shift unit 82 has a neutral position in which the 2 nd shift sleeve 36 does not engage with either of the 3 rd input gear 32 and the 4 th input gear 33. Further, when the 2 nd shift unit 82 slides rightward from the neutral position, the 2 nd shift sleeve 36 engages with the 3 rd input gear 32, and when the 2 nd shift unit 82 slides leftward from the neutral position, the 2 nd shift sleeve 36 engages with the 4 th input gear 33.

When the 2 nd shift sleeve 36 is engaged with the 3 rd input gear 32, the 3 rd input gear 32 rotates integrally with the input shaft 3. Then, the rotation of the input shaft 3 is transmitted to the counter shaft 4 via the 3 rd input gear 32 to the 3 rd intermediate gear 42. This state is the gear ratio of 3 th gear in the transmission gear mechanism 10.

When the 2 nd shift sleeve 36 is engaged with the 4 th input gear 33, the 4 th input gear 33 rotates integrally with the input shaft 3. Then, the rotation of the input shaft 3 is transmitted to the counter shaft 4 via the 4 th input gear 33 to the 4 th counter gear 43. This state is the gear ratio of 4 th gear in the transmission gear mechanism 10.

The 3 rd shift unit 83 is for moving the 3 rd shift sleeve 37 in the axial direction of the input shaft 3, and moving the reverse idler gear 50 in the axial direction of the reverse shaft 5 via the reverse drive lever 51. The 3 rd shift unit 83 has: a 3 rd shift shaft 83a located forward and upward of the 2 nd shift shaft 82a and extending in the left-right direction; a 3 rd shift fork 83b engageable with the finger 74a of the cam member 74; a 3 rd shift fork 83c that engages with the 3 rd shift sleeve 37; and a reverse operation arm 83d connected to the reverse drive lever 51.

The axial direction of the 3 rd shift shaft 83a is parallel to the axial directions of the input shaft 3, the intermediate shaft 4, and the reverse shaft 5. Both ends of the 3 rd shift shaft 83a are supported by a shaft guide hole 124 (see fig. 4) formed in the partition wall 23 of the right case 21 and a shaft guide hole 125 (see fig. 5 and 6) formed in the left end wall 25 of the left case 22 so as to be slidable in the axial direction (left-right direction).

The 3 rd shift fork 83b is a plate-like body having an extension in the horizontal direction, and a distal end portion thereof is coupled to the 3 rd shift shaft 83a (see fig. 2, 3, and 7). A recess opened rearward is formed at the rear end portion of the 3 rd shift fork 83b, and the finger 74a of the cam member 74 or the tip of the curved portion of the lower side plate 77b is disposed in the recess. Therefore, when the position of the finger 74a in the vertical direction matches the height position of the 3 rd shift fork 83b, the finger 74a can be engaged with the recessed portion of the 3 rd shift fork 83b while being positioned in the recessed portion.

The 3 rd shift fork 83C is a plate-like body having a C-shape in side view with a bifurcated tip portion. A base end portion of the 3 rd shift fork 83c is coupled to the 3 rd shift shaft 83a, and a tip end portion of the 3 rd shift fork 83c engages with a groove formed in the 3 rd shift collar 37. The 3 rd shift fork 83c is coupled to the 3 rd shift shaft 83a at a position to the left of the 3 rd shift fork 83b (see fig. 10 and 11).

The reverse operation arm 83d is coupled to the 3 rd shift shaft 83a at a position to the right of the 3 rd shift fork 83b (see fig. 10 and 11). The tip end portion of the reverse operation arm 83d is inserted into the communication hole 51a of the reverse drive lever 51 (see fig. 11 and 13).

The 3 rd shift unit 83 is an integral structure in which a 3 rd shift shaft 83a, a 3 rd shift fork 83b, a 3 rd shift fork 83c, and a reverse operation arm 83d are coupled, and when the shift direction movement of the finger 74a is transmitted to the 3 rd shift fork 83b, the 3 rd shift shaft 83a slides in the axial direction. By sliding the 3 rd shift shaft 83a, the 3 rd shift fork 83c moves the 3 rd shift sleeve 37 in the axial direction of the input shaft 3, and the engagement relationship of the 5 th input gear 34 adjacent to the 3 rd shift sleeve 37 can be switched. Further, by the sliding movement of the 3 rd shift shaft 83a, the reverse operation arm 83d presses the inner surface of the coupling hole 51a to rotate the reverse drive lever 51, and the reverse drive lever 51 moves the reverse idle gear 50 in the axial direction (leftward direction) of the reverse shaft 5. Then, the reverse idle gear 50 is positioned at the same position as the reverse input gear 35 and the reverse intermediate gear 47 in the axial direction of the reverse shaft 5, and the reverse idle gear 50 meshes with the reverse input gear 35 and the reverse intermediate gear 47.

Specifically, in the neutral position of the 3 rd shift unit 83, the 3 rd shift sleeve 37 is separated leftward from the 5 th input gear 34 and does not engage therewith. The reverse idler gear 50 is separated to the right from the reverse input gear 35 and the reverse intermediate gear 47 without meshing with them.

When the 3 rd shift unit 83 slides rightward from the neutral position, the 3 rd shift sleeve 37 engages with the 5 th input gear 34. When the 3 rd shift sleeve 37 is engaged with the 5 th input gear 34, the 5 th input gear 34 rotates integrally with the input shaft 3. Then, the rotation of the input shaft 3 is transmitted to the counter shaft 4 via the 5 th input gear 34 to the 5 th counter gear 44. This state is the gear ratio of 5 th gear in the transmission gear mechanism 10. Further, when the 3 rd shift unit 83 slides rightward from the neutral position, the tip end of the reverse operation arm 83d can move within the communication hole 51a without rotating the reverse drive lever 51, and no force to rotate the reverse drive lever 51 is given from the reverse operation arm 83 d.

When the 3 rd shift unit 83 slides leftward from the neutral position, the distal end of the reverse operation arm 83d presses the inner surface of the engagement hole 51a to rotate the reverse drive lever 51. The rotating reverse drive lever 51 presses the reverse idle gear 50, and the reverse idle gear 50 moves leftward on the reverse shaft 5 to mesh with the reverse input gear 35 and the reverse idler gear 47. Then, the rotation of the input shaft 3 is transmitted to the counter shaft 4 via the reverse input gear 35, the reverse idle gear 50, and the reverse intermediate gear 47. Since the reverse idler gear 50 is provided in the middle, the rotation direction of the intermediate shaft 4 is opposite to the rotation direction in the power transmission from 1 st to 5 th described above. That is, the drive wheels are rotated in the reverse (reverse) direction by the transmission gear mechanism 10.

The 1 st shift fork 81b, the 2 nd shift fork 82b, and the 3 rd shift fork 83b, which are plate-shaped, are arranged to overlap in the vertical direction (see fig. 7). The recessed portion of the 1 st shift fork 81b, the recessed portion of the 2 nd shift fork 82b, and the recessed portion of the 3 rd shift fork 83b are arranged in a straight line. Specifically, the 1 st shift fork 81b, the 2 nd shift fork 82b, and the 3 rd shift fork 83b are arranged in this order from below. The finger 74a of the cam member 74 moves within the recessed portions of the 3 shift forks 81b, 82b and 83b arranged in a straight line in accordance with the vertical movement of the shift select shaft 70 due to the selection operation by the occupant. In response to the rotation of the shift select shaft 70 caused by the shift operation by the occupant, the finger 74a is alternatively engaged with the recess in which it is located, and the shift unit is moved in the axial direction. Further, the bent portion (front end portion) of the upper plate 77a or the lower plate 77b of the interlock plate 77 is arranged for the remaining 2 respective recesses of the 3 shift forks 81b, 82b, and 83b where the finger portion 74a is not present. The shift fork having the interlock plate 77 in the recess is engaged with the interlock plate 77, and movement in the left-right direction (movement in the shift direction) is restricted. Therefore, when the shift select shaft 70 is operated in the shift direction, only 1 of the 3 shift forks 81b, 82b and 83b moves along with the finger 74a, and the other 2 shift forks are restricted from moving and are held at the neutral positions.

When the shift lever operated by the occupant is in the neutral position in both the selection direction and the shifting direction, the 1 st, 2 nd, and 3 rd shift units 81, 82, and 83 are all in the neutral position in the shifting direction, and the rotation of the input shaft 3 is not transmitted to the intermediate shaft 4. That is, the driving force is not transmitted to the final driven gear 60. In the neutral position of the shift lever, the finger 74a of the cam member 74 is biased by the spring to be positioned corresponding to the recess of the 2 nd shift fork 82b in the up-down direction (selecting direction). Therefore, when the shift lever is shifted from the neutral position in this state, the 2 nd shifting unit 82 moves in the shifting direction to select the 3 rd or 4 th gear.

When the shift lever is operated from the neutral position to one of the selection directions, the shift selection shaft 70 moves downward, and the finger 74a of the cam member 74 is positioned corresponding to the concave portion of the 1 st shift fork 81b in the up-down direction (selection direction). When a shift lever is shifted in this state, the 1 st shift unit 81 moves in the shifting direction to select 1 st or 2 nd gear.

When the shift lever is operated from the neutral position to the other side in the selection direction, the shift selection shaft 70 moves upward, and the finger 74a of the cam member 74 is positioned in a position corresponding to the recessed portion of the 3 rd shift fork 83b in the up-down direction (selection direction). When a shift lever is shifted in this state, the 3 rd shift unit 83 moves in the shifting direction to select 5 th gear or reverse gear (reverse gear).

As described above, when the shift speed of the speed change gear mechanism 10 is selected using the shift device 7 and the internal shift mechanism 8, and the counter shaft 4 rotates due to the driving force of the input shaft 3, the rotation is transmitted from the final stage drive gear 45 on the counter shaft 4 to the final stage driven gear 60, driving the drive shaft to rotate. During forward movement in the 1 st to 5 th gears, the final driven gear 60 rotates in a forward direction indicated by an arrow FW in fig. 2 and 3.

The transmission 2 has a lubricating structure for circulating lubricating oil in the transmission case 20 and supplying the lubricating oil to each part. As shown in fig. 2 and 3, the transmission case 20 (left case 22) has the transmission gear mechanism 10 and the internal shift mechanism 8 disposed in an upper portion toward the front, and has the differential device 6 (final driven gear 60) disposed in a lower portion toward the rear. The left case 22 has a lubricant injection port 22b (see fig. 1, 5, and 6) opened leftward toward the rear, and the liquid surface position when the engine is stopped is near the lubricant injection port 22b when the lubricant is injected into the transmission case 20. That is, an oil reservoir is formed in a lower portion of the transmission case 20. In this state, a part of each of the transmission gear mechanism 10 and the differential device 6 is immersed in the lubricating oil reserved in the lower portion of the transmission case 20.

In a state where the engine 1 is running or started and the transmission gear mechanism 10 is rotating, circulation of the lubricating oil occurs in the transmission case 20 due to the operation of the gears and the like in the transmission case 20. In particular, the lubricating oil stored in the lower portion of the transmission case 20 is carried upward by the rotation of the large-diameter final driven gear 60 located in the lower portion of the transmission case 20 at the rear during traveling. Above the final-stage driven gear 60, the rear wall portion 24c of the peripheral wall 24 extends obliquely upward (see fig. 8). The lubricating oil carried up by the final driven gear 60 rotating in the forward direction FW hits the rear wall portion 24c and scatters around or flows along the rear wall portion 24 c. The lubricating oil scattered or flowing in the transmission case 20 lubricates the transmission gear mechanism 10 or the internal shift mechanism 8, and drops downward and returns to the lower portion of the transmission case 20.

However, the position at which the final driven gear 60 is disposed in the transmission case 20 is the right rear position in the left space and the right end side in the left case 22 close to the partition wall 23, and most of the transmission gear mechanism 10 is located leftward of the final driven gear 60. Therefore, the lubricating structure in the transmission 2 according to the present embodiment includes the oil grooves 9, and the oil grooves 9 trap the lubricating oil carried by the final driven gear 60 and supply the lubricating oil to each part of the transmission gear mechanism 10 to be lubricated. Fig. 14 to 16 show a single body shape of the oil groove 9.

The oil groove 9 is located in an upper portion of the transmission case 20 close to the upper wall portion 24a (see fig. 2 to 5). The oil groove 9 forms an oil path that extends in the left-right direction through the left housing 22 from the trap portion 90 located above the final driven gear 60 to the supply end portion 95 adjacent to the left end wall 25 (see fig. 10 to 13). In the oil groove 9, the lubricating oil flows from the trap portion 90 toward the supply end portion 95, with the right side of the trap portion 90 being the upstream and the left side of the supply end portion 95 being the downstream. Each part of the oil groove 9 has a gutter-like cross-sectional shape surrounded by a bottom wall and a side wall that protrudes upward from an edge of the bottom wall, and an upper surface side (upper part of the side wall) of the oil groove 9 is open.

As shown in fig. 14 and 15, the oil groove 9 has: a trap portion 90 located on the most upstream side; an inflow portion 91 connected to the trap portion 90; a 1 st oil passage 92 extending continuously from the inflow portion 91; a 2 nd oil passage 93 that branches off from the inflow portion 91; a merging portion 94 where the 1 st oil passage 92 and the 2 nd oil passage 93 merge; and a supply end 95, which is an end on the downstream side, continuing to the confluence section 94. A through portion 96 that penetrates in the vertical direction is formed in a region surrounded by the 1 st oil passage 92, the 2 nd oil passage 93, and the merging portion 94. In other words, the 1 st oil passage 92 and the 2 nd oil passage 93 are branched through the through portion 96. That is, the oil groove 9 has a penetration portion 96 serving as a through hole that communicates the upper side and the lower side of the oil groove 9 between the 1 st oil passage 92 and the 2 nd oil passage 93.

The trap portion 90 protrudes rearward from the inflow portion 91 and the 1 st oil passage 92, and includes: a flat-shaped bottom wall portion 90 a; a right side wall portion 90b projecting upward from a right edge portion of the bottom wall portion 90 a; and a left side wall portion 90c that protrudes upward from a left edge portion of the bottom wall portion 90 a. The rear end of the trap portion 90 is a trap opening 90d that opens between the right side wall portion 90b and the left side wall portion 90 c. The bottom wall portion 90a is located close to the outer peripheral portion of the final driven gear 60. That is, the bottom wall portion 90a is disposed above the final driven gear 60 at a position close to the outer peripheral portion as shown in fig. 8, and at least a part thereof is disposed at the same position as the final driven gear 60 in the left-right direction as shown in fig. 12. The lubricating oil carried up by the final driven gear 60 rotating in the forward direction FW flows into the trap 90 from the trap opening 90d or the open portion above the trap 90.

The inflow portion 91 extends leftward from the front of the trap portion 90. The bottom wall of the inflow portion 91 has: a curved bottom wall 91a located in front of the bottom wall 90a of the trap 90; a flat bottom wall 91b of a flat shape extending leftward from the curved bottom wall 91 a; a curved bottom wall portion 91c located at a front edge portion of the flat bottom wall portion 91 b; and an inclined bottom wall portion 91d continuous to the left of the flat bottom wall portion 91 b.

The curved bottom wall portion 91a is formed in an arc shape that is continuous with the bottom wall portion 90a and has a larger downward projection amount as it goes forward (see fig. 5 and 8). The curved bottom wall portion 91a has an arc shape along the outer peripheral shape of the final driven gear 60 located immediately below. In other words, the curved bottom wall portion 91a is a relief portion for disposing the oil groove 9 close to the final stage driven gear 60 without interfering therewith, and below the curved bottom wall portion 91a is an arrangement space of the final stage driven gear 60.

The flat bottom wall 91b is continuous with the deepest region of the curved bottom wall 91a, and is located below the bottom wall 90a and the curved bottom wall 91a of the trap 90 (see fig. 5 and 14). The flat bottom wall 91b has a drip hole 100 formed therethrough. The dropping hole 100 is formed in the flat bottom wall 91b at a position close to the front right end, and the 1 st intermediate gear 40 is located in the vicinity below the dropping hole 100 (see fig. 12 and 13). The flat bottom wall 91b is located above the lubricant inlet port 22 b. Therefore, the lubricating oil on the flat bottom wall portion 91b can be dropped downward through all of the dropping holes 100.

The curved bottom wall portion 91c is formed in an arc shape that is continuous with the front portion of the flat bottom wall portion 91b and that is located upward toward the front (see fig. 5 and 15). The arc shape of the curved bottom wall portion 91c follows the outer peripheral shape of the 1 st intermediate gear 40 or the 1 st shift sleeve 46 (including the reverse intermediate gear 47) located immediately below the curved bottom wall portion. In other words, the curved bottom wall portion 91c is a relief portion for disposing the oil groove 9 close to the 1 st intermediate gear 40 or the 1 st shift sleeve 46 without interfering therewith, and below the curved bottom wall portion 91c is a disposition space of the 1 st intermediate gear 40 or the 1 st shift sleeve 46. The inclined bottom wall portion 91d formed continuously with the left end of the flat bottom wall portion 91b has an inclined shape continuous with the 1 st oil passage 92, which becomes gradually shallower (protrudes upward) leftward from the flat bottom wall portion 91 b. The inclined bottom wall 91d is positioned on the right side of the shaft support 29 of the left housing 22 and reaches a position higher than the shaft support 29. That is, the inflow portion 91 (the flat bottom wall portion 91b) is located on the right side of the shaft support portion 29 in the left-right direction, and bulges downward to the side of the shaft support portion 29 in the up-down direction. Therefore, the inflow portion 91 has a portion lower than the trap portion 90 or the 1 st oil passage 92, and functions as a sump for storing the lubricating oil.

The side wall of the inflow portion 91 has: a right side wall portion 91e continuously extending forward from the right side wall portion 90b of the trap portion 90; a front side wall 91f extending leftward from the front end of the right side wall 91 e; a partition wall 91g continuous to the left of the front side wall 91 f; and a rear side wall 91h extending leftward from the left side wall 90c of the trap 90. The upper ends of the right side wall portion 90b, the partition wall portion 91g, the left side wall portion 90c, and the rear side wall portion 91h are formed at substantially the same height. In contrast, the upper ends of the right side wall portion 91e and the front side wall portion 91f are formed high along the inner surface of the peripheral wall 24 as shown in fig. 8.

The left side wall portion 90c of the trap portion 90 is extended forward and provided with a flow straightening rib 91 i. The flow straightening rib 91i and the right side wall portion 91e can smoothly guide the lubricating oil flowing into the trap portion 90 to the inflow portion 91. In particular, the flow of the lubricating oil is guided by the flow straightening ribs 91i to the vicinity of the dropping hole 100 with directionality, and the flow of the lubricating oil to the 1 st oil passage 92 is formed while preventing the backflow from the inflow portion 91 to the trap 90.

The bottom wall portion 90a of the trap portion 90 is located close to the outer periphery of the final driven gear 60, and lubricating oil carried up by the final driven gear 60 is easily introduced (see fig. 8). The curved bottom wall portion 91a of the inflow portion 91 is formed so that the amount of downward projection increases as the final driven gear 60 moves forward along the outer peripheral shape thereof (see fig. 8). The right side wall portion 90b and the right side wall portion 91e are configured such that the height in the vertical direction gradually increases from the rear to the front, approaches the inner surface of the peripheral wall 24, and is highest at the front end portion connected to the front side wall portion 91f (see fig. 5 and 8). Therefore, the most upstream portion of the oil groove 9 from the trap opening 90d to the front side wall portion 91f has a triangular shape that widens from the rear toward the front in side view. A space of a substantially triangular shape in side view, which is surrounded by the upper wall portion 24a, the rear wall portion 24c, and the final stage driven gear 60, exists above the rear portion of the left housing 22, and the most upstream portion of the oil groove 9 is accommodated in the space in a space-saving manner (see fig. 8).

The inflow portion 91 has a wide front-rear direction interval between the front side wall portion 91f and the rear side wall portion 91 h. On the other hand, the partition wall 91g is located closer to the rear wall 91h than the front wall 91f, and the front-rear interval of the inflow portion 91 is narrowed. The partition wall 91g has an inclined portion which is closer to the rear side wall 91h toward the left, and a notch 91j is formed in the inclined portion. That is, the notch 91j opens diagonally forward to the left when viewed from the inflow portion 91 side. The notch 91j is a rectangular opening cut downward from the upper end of the partition wall 91 g.

The partition wall 91g forms a boundary between the inflow portion 91 and a 2 nd oil passage 93 described later. The lubricating oil in the inflow portion 91 is divided into a flow that enters the 1 st oil passage 92 without passing through the notch 91j and a flow that passes through the notch 91j and enters the 2 nd oil passage 93. Of these 2 oil passages, the 1 st oil passage 92 will be described first.

The 1 st oil passage 92 includes: a rear oil passage portion 92a continuously extending leftward from the inflow portion 91; and a left oil passage portion 92b extending forward from the left end portion of the rear oil passage portion 92a and reaching the merging portion 94. Rear oil passage 92a is located rearward of through-hole 96, and left oil passage 92b is located leftward of through-hole 96.

Bottom wall 92c forming the bottom wall of 1 st oil passage 92 is continuous with the highest left end portion of inclined bottom wall 91d of inflow portion 91, and is located above flat bottom wall 91 b. The bottom wall 92c is located above the bottom wall 90a of the trap 90. As shown in fig. 7, the bottom wall portion 92c is located above the shaft support portion 29 of the left housing 22, and the 1 st oil passage 92 is disposed so as to pass above the shaft support portion 29. Bottom wall 92c is smooth and has no step from rear oil passage 92a to left oil passage 92 b.

The side wall of the 1 st oil passage 92 has: an inner peripheral side wall portion 92d located on the inner peripheral side surrounding the through portion 96; and an outer peripheral side wall portion 92e that constitutes an outer edge (trailing edge) portion of the 1 st oil passage 92. In the rear oil passage portion 92a, an inner peripheral side wall portion 92d is provided standing upward from the front end of the bottom wall portion 92c, and extends in the left-right direction continuously with the partition wall portion 91g of the inflow portion 91. The height position of the upper end of the inner peripheral side wall portion 92d is substantially the same as the height position of the upper end of the partition wall portion 91g, and is substantially the same as the height position of the upper end of the outer peripheral side wall portion 92 e. As shown in fig. 7, the upper end of the inner peripheral side wall portion 92d is spaced apart from the rear wall portion 24c of the left housing 22, and the lubricating oil flowing in through the space between the upper end of the inner peripheral side wall portion 92d and the rear wall portion 24c can be received by the rear oil passage portion 92 a. Further, in the rear oil passage portion 92a, an outer peripheral side wall portion 92e is provided standing upward from the rear end of the bottom wall portion 92c, and extends in the left-right direction continuously with the rear side wall portion 91h of the inflow portion 91. The height position of the upper end of the outer peripheral side wall portion 92e is substantially the same as the height position of the upper end of the rear side wall portion 91h, and is substantially the same as the height position of the upper end of the inner peripheral side wall portion 92 d. As shown in fig. 7, the upper end of the outer peripheral side wall portion 92e is disposed close to the rear wall portion 24c of the left housing 22, and the amount of lubricating oil passing through the upper space of the rear oil passage portion 92a can be reduced so that more lubricating oil is received by the rear oil passage portion 92a, and the amount of lubricating oil leaking from the rear oil passage portion 92a to the rear side through the upper side of the outer peripheral side wall portion 92e can be reduced. By setting the extending direction of the inner peripheral side wall portion 92d and the outer peripheral side wall portion 92e, the lubricating oil can smoothly flow from the inflow portion 91 to the rear oil passage portion 92 a. Since the rear wall portion 91h and the outer peripheral side wall portion 92e are disposed along the rear wall portion 24c of the left housing 22 in proximity to the rear wall portion 24c, the inflow portion 91 and the 1 st oil passage 92 are disposed at the rearmost position (setting limit) in the left housing 22 (see fig. 7 and 10). The rear oil passage 92a is disposed to pass between the shifter 7 and the rear wall portion 24c above the shaft support portion 29.

In left oil passage portion 92b, inner peripheral wall portion 92d and outer peripheral wall portion 92e extend diagonally forward and leftward from rear oil passage portion 92a, respectively. In left oil passage portion 92b, inner peripheral side wall portion 92d is provided standing upward from the right end of bottom wall portion 92c, and outer peripheral side wall portion 92e is provided standing upward from the left end of bottom wall portion 92 c. In the vicinity of the left end of the left housing 22, the rear wall portion 24c is inclined so as to protrude forward (closer to the front wall portion 24b) as it goes to the left, and the outer peripheral side wall portion 92e in the left oil passage portion 92b has a shape corresponding to the inclination of the rear wall portion 24c (see fig. 10). That is, left housing 22 is tapered toward the left end, and outer peripheral wall 92e of left oil passage portion 92b is curved from outer peripheral wall 92e of rear oil passage portion 92a in a shape along the inner surface of rear wall 24 c. As shown in fig. 2 and 16, the height position of the upper end of outer peripheral wall 92e of left oil passage 92b is lower toward the front (left). In left oil passage portion 92b, the interval between inner peripheral wall portion 92d and outer peripheral wall portion 92e increases toward the front. Left oil passage portion 92b is bent with respect to rear oil passage portion 92a, but the angle of bending is kept small, and the distance between inner peripheral wall portion 92d and outer peripheral wall portion 92e is gradually increased, so that the lubricating oil can smoothly flow from rear oil passage portion 92a to left oil passage portion 92 b.

As shown in fig. 14 and 16, a plate-shaped flow regulating rib 92f projecting upward from the bottom wall portion 92c is provided at the tip end portion of the left oil passage portion 92 b. The rectifying rib 92f extends in the left-right direction and partially blocks a space between the inner peripheral side wall portion 92d and the outer peripheral side wall portion 92 e. The height position of the upper end of the flow straightening rib 92f is lower than the height position of the upper end of the inner peripheral side wall portion 92d, but is substantially the same as the height position of the upper end of the outer peripheral side wall portion 92e, and functions as a dam for storing the lubricating oil in the trap portion 90, the inflow portion 91, and the 1 st oil passage 92. The height position of the upper end of the rectifying rib 92f is set to be higher than the height of the lower end of the notch 91j (see fig. 16). Gaps are provided between the rectifying rib 92f and the inner peripheral wall 92d and between the rectifying rib and the outer peripheral wall 92e at both end portions thereof. The lubricating oil flows from the 1 st oil passage 92 to the merging portion 94 through these gaps. In particular, the gap between the flow straightening rib 92f and the outer peripheral wall portion 92e is set to be larger, and the lubricating oil easily flows from the portion along the outer peripheral wall portion 92e toward the supply end portion 95 side of the joint portion 94 (the left side of the joint portion 94).

Next, the 2 nd oil passage 93 will be described. The 2 nd oil passage 93 is an oil passage that connects the inflow portion 91 and the confluence portion 94, and into which the lubricating oil flows from the inflow portion 91 through the notch 91j formed in the partition wall portion 91 g. When the oil groove 9 is viewed in plan as shown in fig. 12, the 2 nd oil passage 93 extends from the inflow portion 91 substantially diagonally forward to the left on the side opposite to the side on which the trap portion 90 is disposed. A notch 91j, which is a connection portion between the 2 nd oil passage 93 and the inflow portion 91 and is located at the start portion of the 2 nd oil passage 93, opens in the extending direction of the 2 nd oil passage 93. That is, since the partition wall portion 91g in which the notch 91j is formed substantially perpendicular to the extending direction of the 2 nd oil passage 93 and the 2 nd oil passage 93 extends in the flowing (traveling) direction of the lubricating oil flowing in through the notch 91j, the flow of the lubricating oil in the 2 nd oil passage 93 can be made smooth.

The 2 nd oil passage 93 has an oil catch tank portion 93a located on the front side of the partition wall portion 91g of the inflow portion 91 on the upstream side, and a front oil passage portion 93b located on the downstream side connects the oil catch tank portion 93a and the junction 94. The oil collection tank 93a is located rightward of the through portion 96, and the front oil passage 93b is located forward of the through portion 96.

The bottom wall of the 2 nd oil passage 93 has: a lower bottom wall portion 93c located adjacent to the front side of the partition wall portion 91 g; a curved bottom wall portion 93d located on the front side of the lower bottom wall portion 93 c; an upper-stage bottom wall portion 93e located in front left of the curved bottom wall portion 93 d; and a transition bottom wall portion 93f connecting the curved bottom wall portion 93d and the upper-stage bottom wall portion 93 e. The lower-stage bottom wall portion 93c and the curved bottom wall portion 93d constitute a bottom wall of the oil collection tank portion 93a, and the upper-stage bottom wall portion 93e constitutes a bottom wall of the front oil passage portion 93 b. The transition bottom wall portion 93f constitutes a bottom wall of a boundary portion between the oil collection tank portion 93a and the front oil passage portion 93 b.

The lower bottom wall portion 93c has a flat shape. The lower bottom wall portion 93c is located at the lowermost portion of the bottom walls of the oil grooves 9 (see fig. 4, 5, and 16). The upper-stage bottom wall portion 93e has an arc shape that curves gradually downward from the leading edge side toward the trailing edge side (see fig. 7). Upper-stage bottom wall portion 93e is located above lower-stage bottom wall portion 93c and below bottom wall portion 92c of 1 st oil passage 92 (see fig. 16).

The curved bottom wall portion 93d is an arc portion having a shape in which the amount of upward projection increases as going from the lower bottom wall portion 93c to the front (see fig. 4 and 5). The curved bottom wall portion 93d has an arc shape that follows the outer peripheral shape of the reverse intermediate gear 47, the 2 nd intermediate gear 41, and the 3 rd intermediate gear 42. In other words, the curved bottom wall portion 93d is a relief portion for disposing the oil groove 9 close to the reverse intermediate gear 47, the 2 nd intermediate gear 41, and the 3 rd intermediate gear 42 without interfering therewith, and below the curved bottom wall portion 93d is a disposition space of the reverse intermediate gear 47, the 2 nd intermediate gear 41, and the 3 rd intermediate gear 42. The transition bottom wall portion 93f is an arc portion having a basic arc shape similar to the curved bottom wall portion 93d, and is a portion gradually transitioning from the arc shape of the upper-stage bottom wall portion 93e to the arc shape of the curved bottom wall portion 93 d. The arc shape of the upper-stage bottom wall portion 93e and the arc shape of the curved bottom wall portion 93d are formed concentrically with the axis of the intermediate shaft 4 as the center axis, and the arc shape of the upper-stage bottom wall portion 93e is formed to have a smaller diameter.

A drip hole 101 is formed through the curved bottom wall 93d, and a drip hole 102 is formed through the transition bottom wall 93 f. The dropping hole 101 is formed near the center of the curved bottom wall portion 93d, and the 2 nd intermediate gear 41 is positioned below the dropping hole 101 (see fig. 12 and 13). The drip hole 102 is positioned further to the left front than the drip hole 101, and the 3 rd intermediate gear 42 is positioned below the drip hole 102 (see fig. 12 and 13). The lower bottom wall 93c has a discharge hole 105 formed therethrough. Gears and the like constituting the transmission gear mechanism 10 are not located below the discharge hole 105. The area between the 3 rd intermediate gear 42 and the 4 th intermediate gear 43 on the counter shaft 4 is located below the upper-stage bottom wall portion 93 e.

The side wall of the 2 nd oil passage 93 has: an inner peripheral side wall portion 93g located on the inner peripheral side surrounding the through portion 96; and an outer peripheral side wall portion 93h that constitutes an outer edge (front edge) portion of the 2 nd oil passage 93. In the oil collection tank portion 93a, the inner peripheral side wall portion 93g has a shape rising upward from the end edge (left end edge) on the side of the through portion 96 of the lower bottom wall portion 93c, extends forward from the inner peripheral side wall portion 92d, and is bent leftward in the forward oil passage portion 93 b. Further, in the front oil passage portion 93b, the inner peripheral side wall portion 93g is shaped to rise upward from the end edge (rear end edge) on the side of the through portion 96 of the upper-stage bottom wall portion 93e, and extends in the left-right direction. The height of the upper end of inner peripheral side wall 93g is lower than bottom wall 92c of 1 st oil passage 92. The outer peripheral side wall portion 93h is formed in a shape rising upward from the front edges of the curved bottom wall portion 93d and the upper step bottom wall portion 93e in the oil collection tank portion 93a and the front oil passage portion 93 b. Further, a part of the outer peripheral side wall portion 93h becomes an inclined portion 93i, and the inclined portion 93i is inclined so as to be positioned leftward as going forward. The inclined portion 93i extends obliquely leftward and frontward from the front portion of the oil collection tank portion 93a and is disposed up to the front portion of the forward oil passage portion 93b, and due to the shape of the inclined portion 93i, in the forward oil passage portion 93b, the interval between the inner peripheral side wall portion 93g and the outer peripheral side wall portion 93h becomes wider leftward.

A plate-shaped flow straightening rib 93j protruding upward from the upper-stage bottom wall portion 93e is provided at the left end portion of the front oil passage portion 93 b. The flow straightening rib 93j extends in the front-rear direction and partially blocks a gap between the inner peripheral side wall portion 93g and the outer peripheral side wall portion 93 h. The amount of upward projection of the flow straightening rib 93j is smaller (lower) than the inner peripheral side wall portion 93g and the outer peripheral side wall portion 93h adjacent thereto. Further, a gap is present between the rectifying rib 93j and the outer peripheral wall 93 h. The lubricating oil flows from the 2 nd oil passage 93 to the merging portion 94 through the gap or the upper portion of the flow straightening rib 93 j. Further, the flow-straightening rib 93j suppresses the flow of the lubricating oil from the merging portion 94 to the 2 nd oil passage 93.

The merging portion 94 is located forward of the left oil passage portion 92b of the 1 st oil passage 92 and leftward of the front oil passage portion 93b of the 2 nd oil passage 93. The bottom wall of the merging portion 94 has: an upper-stage bottom wall portion 94a located adjacent to the upper-stage bottom wall portion 93e of the 2 nd oil passage 93 on the left side (with the flow rectification rib 93j interposed therebetween); and a lower-stage bottom wall portion 94b located on the left side of the upper-stage bottom wall portion 94 a.

Upper-stage bottom wall 94a is located at a height position slightly higher than the front end of upper-stage bottom wall 93e of 2 nd oil passage 93 and lower than bottom wall 92c of 1 st oil passage 92 (see fig. 16). In the upper-stage bottom wall portion 94a, a drip hole 103 and a drip hole 104 are formed to penetrate therethrough. The dropping hole 103 is formed at a position closer to the right of the upper-stage bottom wall portion 94a, and the 4 th intermediate gear 43 is positioned below the dropping hole 103 (see fig. 12 and 13). The dropping hole 104 is formed on the left side of the dropping hole 103, and the 5 th intermediate gear 44 is located below the dropping hole 104 (see fig. 12 and 13). The upper-section bottom wall portion 94a is a flat surface inclined to be low on the front side.

The lower-stage bottom wall portion 94b is formed at a position lower than the upper-stage bottom wall portion 94a by one step. The lower bottom wall portion 94b is inclined to be lower on the front side, similarly to the upper bottom wall portion 94 a. That is, the lower bottom wall portion 94b is located lower than the upper bottom wall portion 94a and the bottom wall portion 92c, so that the lubricating oil easily flows in, and the lubricating oil flowing in is collected forward, whereby the lubricating oil can be smoothly supplied to the supply end portion 95. The area between the 5 th intermediate gear 44 on the intermediate shaft 4 and the bearing 4b is located below the lower-stage bottom wall portion 94 b.

The side wall of the merging portion 94 has: a left side wall portion 94c that is provided to stand upward from a left end edge of the lower bottom wall portion 94b, is connected to a front end of the outer peripheral side wall portion 92e of the 1 st oil passage 92, and extends forward; a front side wall portion 94d that is provided standing upward from a front end edge of the upper bottom wall portion 94a or a front end edge of the lower bottom wall portion 94b, is connected to a left end of the outer peripheral side wall portion 93h of the 2 nd oil passage 93, and extends leftward; and an inner peripheral side wall portion 94e that is provided standing upward from a rear end edge of the upper bottom wall portion 94a and connects the inner peripheral side wall portion 92d and the inner peripheral side wall portion 93 g. The height position of the upper end of the side wall of the confluence portion 94 is the same as the height position of the upper end of the side wall of the 2 nd oil passage 93.

The lower bottom wall 94b of the merging portion 94 is provided with a flow straightening rib 94 f. The flow straightening rib 94f extends forward from the vicinity of the left end of the flow straightening rib 92f provided in the left oil passage portion 92 b. The front end of the flow straightening rib 94f ensures a gap between the front side wall portion 94d and the front end portion 94d, and is located in the vicinity of the front side wall portion 94 d. The lubricating oil that has passed between the left end portion of the flow straightening rib 92f and the outer peripheral side wall portion 92e in the 1 st oil passage 92 and has flowed into the merging portion 94 passes between the flow straightening rib 94f and the left side wall portion 94c and flows toward the supply end portion 95. On the other hand, the lubricating oil that has entered the merging portion 94 from the 2 nd oil passage 93 passes between the front end of the flow straightening rib 94f and the front side wall portion 94d and flows toward the supply end portion 95. The flow straightening rib 94f is provided upright, and the interval between the flow straightening rib and the left side wall portion 94c gradually becomes narrower toward the front (see fig. 12 and 14), and lubricating oil can be smoothly flowed from either of the 1 st oil passage 92 and the 2 nd oil passage 93 to the supply end portion 95 side. In this way, the lubricating oil passing through the 1 st oil passage 92 and the lubricating oil passing through the 2 nd oil passage 93 are smoothly guided to the supply end portion 95 by the flow straightening ribs 94f that divide the interior of the merging portion 94 without interfering with each other. The rectifying rib 94f is set to a height lower than that of the left side wall portion 94c, and when a large amount of lubricating oil flows into the merging portion 94, the lubricating oil can pass above the rectifying rib 94 f.

The supply end portion 95 protrudes leftward from the left edge portion of the front portion of the merging portion 94. The bottom wall portion 95a constituting the bottom wall of the supply end portion 95 is inclined, and the rear end portion thereof is continuous with the lower bottom wall portion 94b and is located downward toward the front.

The side wall of the supply end portion 95 has: a rear side wall portion 95b extending leftward from the front end of the left side wall portion 94 c; a front side wall portion 95c rising upward from the front edge of the bottom wall portion 95a and connected to the front side wall portion 94 d; an end wall portion 95d bent forward from the left end of the rear side wall portion 95 b; and an end wall portion 95e bent forward from the left end of the front side wall portion 95 c. An end opening 95f that opens leftward is formed between the end wall portion 95d and the end wall portion 95e (between the end wall portion 95d and the front side wall portion 95 c). The end wall portion 95e has an inclined shape, and protrudes downward toward the front along the inclination of the bottom wall portion 95a (see fig. 4). The end wall portion 95d slightly protrudes leftward from the end wall portion 95 e.

The through portion 96 is a hole formed to penetrate the oil groove 9 in the vertical direction, and in a plan view of the oil groove 9 shown in fig. 12 and the like, the through portion 96 is a space opened in the vertical direction and surrounded by the inner peripheral side wall portion 92d of the 1 st oil passage 92, the inner peripheral side wall portion 93g of the 2 nd oil passage 93, and the inner peripheral side wall portion 94e of the merging portion 94. The 1 st oil passage 92 and the 2 nd oil passage 93 are vertically different from each other, and the 1 st oil passage 92 is located above and the 2 nd oil passage 93 is located below (see fig. 7 and 16). Accordingly, the positions of inner peripheral side wall portion 92d and inner peripheral side wall portion 93g are vertically shifted, and the range of vertical penetration portion 96 is from the upper end of inner peripheral side wall portion 92d of 1 st oil passage 92 to the lower end of inner peripheral side wall portion 93g of 2 nd oil passage 93.

As shown in fig. 11, a support protrusion 96a protruding inward of the through-portion 96 is provided near the boundary between the inner peripheral side wall portion 94e and the inner peripheral side wall portion 92 d. The support projection 96a is a cantilever-like projection having a free end at the tip end, and is elastically deformable in the front-rear direction with a base end as a fulcrum.

As shown in fig. 11, the oil groove 9 also has a hook 97 and a hook 98. The hook 97 is a hook-shaped portion protruding leftward from the left side wall 90c of the trap 90. The hook portion 98 is a hook-shaped portion protruding leftward from a wall portion formed by extending the right side wall portion 91e of the inflow portion 91 forward.

As shown in fig. 6, in the left housing 22, surfaces parallel to the mating surface 22a are arranged at positions close to the mating surface 22a, and on these parallel surfaces, an engaged portion 27 with which the hook portion 97 is engaged and an engaged portion 28 with which the hook portion 98 is engaged are formed. The engaged portions 27 and 28 are holes formed in the left housing 22 and open in the right direction. When the hook portions 97 and 98 are inserted into the engaged portions 27 and 28, the hook shape is elastically deformed, and the hook portions 97 and 98 engage with the engaged portions 27 and 28, whereby the oil groove 9 is held in the left housing 22. In a state where the oil groove 9 is mounted in the left housing 22, the through portion 96 of the oil groove 9 is positioned below the opening 26 formed in the upper wall portion 24 a. Further, the support projection 96a projecting inward of the through portion 96 contacts the outer surface of the shaft support portion 29 in the left housing 22, whereby the oil groove 9 can be stabilized, and the end wall portion 95d on the left end side of the supply end portion 95 is inserted into the communication recess 116 of the left end wall 25 as described later, whereby the oil groove 9 can be stabilized. Further, the surfaces on which the engaged portions 27, 28 are formed are arranged at positions close to the engaging surface 22a in the left-right direction, and after the left housing 22 and the right housing 21 are coupled, the movement of the oil groove 9 to the right side is restricted by the right housing 21, and the hook portions 97, 98 cannot come off from the engaged portions 27, 28.

A communication recess 116 (see fig. 6 and 9) that communicates with the support recess 111 of the support bearing 3b is formed in the left end wall 25 of the left housing 22. The communication recess 116 is a recess extending rearward and upward from the support recess 111, and has a groove shape open to the right. When the hook portions 97 and 98 are engaged with the engaged portions 27 and 28 and the oil groove 9 is mounted in the left housing 22, the end wall portion 95d and the end wall portion 95e on the left end side of the supply end portion 95 are inserted into the communication recess 116. Further, since end wall portion 95e matches the shape of communication recess 116 to close the opening on the right side of communication recess 116, and rear end wall portion 95d protrudes to the left side from front end wall portion 95e (the gap between end wall portion 95e and the back wall of communication recess 116 is larger), the lubricating oil flowing out from end opening 95f easily flows to the support recess 111 side through the gap between end wall portion 95e and communication recess 116.

Inside the input shaft 3 supported by the bearing 3b are formed: an axial hole 3c (see fig. 2) extending in the axial direction, and a radial hole (not shown) extending in the radial direction from the axial hole 3c and communicating with the support position of each gear or shift sleeve on the input shaft 3. The axial hole 3c is open at the left end of the input shaft 3 (see fig. 2), and in the assembled state of the left housing 22, the axial end opening of the axial hole 3c faces the support recess 111 (see fig. 9). That is, the axial hole 3c communicates with the support concave portion 111 and the communication concave portion 116. Therefore, the lubricating oil that flows into the communication recess 116 from the end opening 95f of the oil groove 9 is introduced into the axial hole 3c of the input shaft 3, and is supplied to the periphery of each speed change gear or shift sleeve on the input shaft 3 through the radial hole. Further, the lubricating oil supplied into the support concave portion 111 lubricates the bearing 3b and flows to the left space of the transmission case 20 through the bearing 3b, but the amount of the lubricating oil passing through the bearing 3b is limited by the lubricating oil introducing member 117 disposed in the support concave portion 111 (see fig. 9). The lubricating oil introducing member 117 is a member having: a disc portion covering a part of a side surface of the bearing 3 b; and a cylindrical portion which protrudes from the disk portion and is inserted into the axial hole 3c, wherein the disk portion restricts a flow rate to the bearing 3b, and the cylindrical portion guides the lubricating oil into the axial hole 3 c.

Inside the intermediate shaft 4 are also formed: an axial hole 4c (see fig. 2, 3, 7, 8, and 9) extending in the axial direction, and a radial hole (not shown) extending in the radial direction from the axial hole 4c and communicating with the support position of each gear or shift sleeve on the counter shaft 4. The axial holes 4c are open at both ends of the intermediate shaft 4. Lubricating oil is supplied to the periphery of each speed change gear or shift sleeve on the counter shaft 4 through the axial hole 4c and the radial hole.

When the transmission 2 is assembled, the transmission gear mechanism 10 or the internal shift mechanism 8 is assembled in advance to the right housing 21 side in an upright state with the left side facing upward. Then, the left case 22 is assembled to the right case 21 so as to cover from above in a state where the oil groove 9 is assembled in the left case 22.

When the left housing 22 is assembled, the oil groove 9 in the left housing 22 cannot be visually recognized. Therefore, if the left housing 22 is assembled to the right housing 21 in a state of being displaced from the predetermined position, the oil groove 9 may contact a structure attached to the right housing 21. In particular, the portion of the oil groove 9 from the forward oil path portion 93b to the confluence portion 94 and the supply end portion 95 enters a narrow space between the 1 st and 2 nd shift shafts 81a and 82a and the intermediate shaft 4, and therefore, contact or collision is easily generated at this portion. More specifically, the distal end of the 1 st shift shaft 81a or the 2 nd shift shaft 82a is likely to abut on the vicinity of the front oil passage portion 93 b.

The front oil passage portion 93b of the oil groove 9 has an inclined portion 93i in the outer peripheral side wall portion 93 h. The inclined portion 93i is inclined with respect to the axial direction (left-right direction) of the 1 st shift shaft 81a or the 2 nd shift shaft 82 a. Therefore, when the tip end of the 1 st shift shaft 81a or the 2 nd shift shaft 82a abuts against the inclined portion 93i, the inclined portion 93i functions as a guide portion for guiding the assembly of the left housing 22 and is not difficult to assemble. In particular, since the inclined portion 93i is inclined such that the amount of forward projection increases toward the left, when the left case 22 attempts to move toward the right case 21 in a state where the tip end of the 1 st shift shaft 81a or the 2 nd shift shaft 82a abuts on the inclined portion 93i, a component force of movement toward the rear is generated with respect to the oil groove 9. Then, the oil groove 9 and the left housing 22 are guided to appropriate positions in the front-rear direction. Thus, the damage of the component can be prevented, and the assembling workability can be improved. That is, the inclined portion 93i can release the force slowly, and the oil groove 9 made of a resin material can be prevented from being collided or caught, thereby preventing the oil groove 9 from being damaged.

When the assembly of the left housing 22 to the right housing 21 is completed, the oil groove 9 is accommodated in the peripheral space of the transmission gear mechanism 10 and the internal shift mechanism 8. As shown in fig. 2, 3, and 7, a portion of the oil groove 9 from the front oil passage portion 93b disposed on the front side of the through portion 96 to the joining portion 94 and the supply end portion 95 is located below the 1 st shift shaft 81a and the 2 nd shift shaft 82a above the intermediate shaft 4. In particular, the front oil passage portion 93b is disposed between the 2 nd shift fork 82c and the shaft support portion 29 in the front-rear direction, between the shift forks 81b, 82b, and 83b and the intermediate shaft 4 in the up-down direction, and directly below the shift forks 81b, 82b, and 83b (see fig. 7 and 11).

After the right and left housings 21 and 22 are combined, the shift device 7 is further mounted to the left housing 22. The shift device 7 is unitized in advance, and a portion of the shift device 7 that protrudes downward from the lid portion 71a is inserted into the left housing 22 through the opening 26 formed in the upper wall portion 24 a. The insertion portion of the shifting device 7 comprises: a portion of the shift select shaft 70, a depending portion 71c of the shift case 71, a cam member 74, a plunger 75, an interlock plate 77, and a shift guide 78. The lower end portion of the shift select shaft 70 is inserted into a hole of the shaft support portion 29 in the left housing 22, and is slidably supported by the shaft support portion 29 (see fig. 7).

After the cover portion 71a of the shift case 71 is overlapped on the upper surface of the upper wall portion 24a and fastened by bolting or the like, the attachment of the shift device 7 is completed. In this state, the finger 74a of the cam member 74 is positioned in the recessed portion of any one of the 1 st shift fork 81b, the 2 nd shift fork 82b, and the 3 rd shift fork 83b, and can transmit the operating force from the shift device 7 to the internal shift mechanism 8. In a state where the attachment of the shift device 7 is completed, the front oil passage portion 93b is located directly below the finger portion 74a or the interlock plate 77 and at a position overlapping in a plan view. Further, the rear oil passage portion 92a disposed on the rear side of the through portion 96 is disposed between the cam member 74 and the rear wall portion 24c passing above the shaft support portion 29.

As described above, the penetrating portion 96 of the oil groove 9 is located below the opening 26 of the left housing 22. A part of the shift device 7 inserted into the left housing 22 from the opening 26 is located inside the through portion 96. That is, the oil groove 9 constitutes a bifurcated oil passage surrounding the insertion portion of the shift device 7 inserted into the left housing 22, the 1 st oil passage 92 (rear oil passage portion 92a) passes behind the insertion portion of the shift device 7, and the 2 nd oil passage 93 (front oil passage portion 93b) passes in front of the insertion portion of the shift device 7 (see fig. 7).

The operation of the oil groove 9 assembled in the transmission case 20 as described above will be described. When the engine 1 is driven and the rotation of the input shaft 3 is transmitted via the intermediate shaft 4 and the final driven gear 60 rotates in the forward direction FW, the lubricating oil carried up by the final driven gear 60 from the oil reservoir at the lower portion of the transmission case 20 flows into the trap portion 90 of the oil groove 9. The lubricating oil having entered the trap portion 90 enters the inflow portion 91 under the guidance of the rectifying rib 91i and the like. The right side wall portion 91e or the front side wall portion 91f located in front of the trap portion 90 is disposed so that the upper end thereof is close to the upper wall portion 24a to substantially block a space from the final driven gear 60 to the upper wall portion 24a (see fig. 8). Therefore, the lubricating oil that flows along the upper wall portion 24a and attempts to forcibly scatter forward beyond the trap portion 90 can be reliably introduced into the inflow portion 91.

When a predetermined amount of lubricating oil is accumulated in the inflow portion 91, the lubricating oil is branched to the 1 st oil passage 92 and the 2 nd oil passage 93 and flows downstream. When the liquid surface position in inflow portion 91 reaches bottom wall portion 92c of 1 st oil passage 92, a flow from inflow portion 91 to 1 st oil passage 92 occurs. When the liquid surface position in the inflow portion 91 reaches the lower end of the notch 91j, a flow from the inflow portion 91 to the 2 nd oil passage 93 occurs. By appropriately setting the height positions of the bottom wall portion 92c and the lower end portion of the notch 91j, the timing at which the lubricating oil flows from the inflow portion 91 to the 1 st oil passage 92 and the timing at which the lubricating oil flows from the inflow portion 91 to the 2 nd oil passage 93 can be adjusted.

The lubricating oil flowing into the 1 st oil passage 92 flows from the rear oil passage portion 92a through the left oil passage portion 92b to the rear and left spaces of the shift select shaft 70. When the lubricating oil reaches the flow straightening rib 92f, the lubricating oil is once stopped, and flows to the merging portion 94 while bypassing the flow straightening rib 92 f. At this time, the lubricating oil enters the joining portion 94 through the gap between the flow straightening rib 92f and the outer peripheral wall portion 92e, is guided by the flow straightening rib 94f to advance forward, and this flow becomes dominant.

On the other hand, the lubricating oil flowing into the 2 nd oil passage 93 accumulates in the oil catch tank 93a adjacent to the inflow portion 91. When the amount of the lubricating oil in the oil collection tank portion 93a exceeds a predetermined amount, the lubricating oil flows into the front oil passage portion 93b through the curved bottom wall portion 93d or the transition bottom wall portion 93 f.

The lubricating oil flowing into the forward oil passage portion 93b flows through a space in front of the shift select shaft 70. When the lubricating oil reaches the flow straightening rib 93j, the lubricating oil is once stopped, passes through a gap between the flow straightening rib 93j and the outer peripheral wall portion 93h, or passes over the flow straightening rib 93j, and flows into the joining portion 94. The lubricating oil that has entered the merging portion 94 through the 2 nd oil passage 93 is guided forward by the flow straightening rib 94 f.

The lubricating oil passing through the 1 st oil passage 92 and the lubricating oil passing through the 2 nd oil passage 93 are guided and merged along the flow straightening ribs 94f in the merging portion 94, and reach the supply end portion 95. The lubricating oil reaching the supply end portion 95 is discharged from the end opening 95f to the outside of the oil groove 9. The end opening 95f opens in the communication recess 116 of the left housing 22, and the lubricating oil discharged from the end opening 95f enters the communication recess 116, and enters the axial hole 3c of the input shaft 3 via the communication recess 116 and the support recess 111 (see fig. 9). At this time, the amount of the lubricant passing through the bearing 3b is adjusted by the lubricant introducing member 117 (fig. 9) in the support concave portion 111, and the lubricant is introduced into the axial hole 3 c. And, the lubricating oil is supplied to the supporting positions of the respective speed change gears (30, 31, 32, 33, 34, 35) or the respective shift sleeves (36, 37) supported to the input shaft 3 through the axial hole 3c and the radial hole of the input shaft 3 and lubricates these portions.

Thus, the oil groove 9 functions as a gutter that guides the lubricating oil carried by the final driven gear 60 to the shaft end of the input shaft 3 on the left end wall 25 side of the left housing 22 opposite to the partition wall 23. Since the oil groove 9 has the 1 st oil passage 92 and the 2 nd oil passage 93 that branch off and pass in front and rear of the shift device 7, a sufficient flow rate of the lubricating oil can be ensured, and a restricted space around the shift device 7 can be arranged without interfering with the shift device 7.

Further, the lubricating oil dropped from the dropping hole provided in the bottom wall of the oil groove 9 can be supplied to the speed change gears (40, 41, 42, 43, 44) and the shift sleeve (46) on the counter shaft 4. The oil groove 9 has a dropping hole 100 in the bottom wall of the inflow portion 91, dropping holes 101 and 102 in the bottom wall of the 2 nd oil passage 93, and dropping holes 103 and 104 in positions adjacent to the 2 nd oil passage 93 in the merging portion 94. Lubricating oil can be directly supplied from these respective dropping holes to the gear tooth surfaces of the speed change gears of the 1 st intermediate gear 40 to the 5 th intermediate gear 44 on the intermediate shaft 4.

In particular, in the intermediate shaft 4, the diameter of the speed change gear is reduced as the shift speed is higher, and the position of the dropping hole needs to be set forward. Therefore, by providing the 2 nd oil passage 93 that passes through the front side of the shift device 7, the lubricating oil can be reliably guided to the positions directly above the shift range gears that are not located below the 1 st oil passage 92 that passes through the rear side of the shift device 7. Thus, excellent lubricating performance can be imparted to all the gears on the intermediate shaft 4.

As shown in fig. 16, the bottom wall of the oil groove 9 in which the respective dropping holes are formed is different in vertical position. Specifically, the lower-stage bottom wall portion 93c in which the discharge holes 105 are formed is located lowermost. The flat bottom wall portion 91b in which the dropping hole 100 for dropping the lubricating oil to the 1 st idler gear 40 for 1 st gear is formed is located at the 2 nd low position. The curved bottom wall portion 93d in which the dropping hole 101 for dropping the lubricating oil to the 2 nd intermediate gear 41 for the 2 nd gear is formed is located at the 3 rd lower position. The transition bottom wall portion 93f in which the dropping hole 102 for dropping the lubricating oil to the 3 rd intermediate gear 42 for the 3 rd gear is formed is at the 4 th low position. The upper bottom wall portion 94a in which the dropping holes 103 and 104 for dropping the lubricating oil to the 4 th intermediate gear 43 for the 4 th gear and the 5 th intermediate gear 44 for the 5 th gear are formed is located at the uppermost position. That is, the lower the bottom wall having the dropping hole for the lower position, the lower the position.

Therefore, when the engine 1 is driven to start running from a state where the lubricating oil is not stored in the oil groove 9, the lubricating oil flows from the trap portion 90 into the inflow portion 91, and the dropping of the lubricating oil starts from the dropping hole 100 located at the uppermost stream and the lowermost stream. When the retained oil surface in the oil groove 9 rises and the lubricating oil flows into the 2 nd oil passage 93 from the inflow portion 91, the lubricating oil drops from the dropping hole 101 located downstream and above the dropping hole 100. Next, when the oil collection tank portion 93a provided with the dropping hole 101 is filled with the lubricating oil, the lubricating oil drops from the dropping hole 102 located downstream and above the dropping hole 101. Further, when the lubricating oil flows through the 2 nd oil passage 93 and fills the merging portion 94, the lubricating oil sequentially drops from the dropping holes 103 and 104 located downstream and above the dropping hole 102. When the lubricating oil flows into the oil catch tank 93a of the 2 nd oil passage 93, a predetermined amount of the lubricating oil drops downward from the drain hole 105 located below all of the dropping holes 100, 101, 102, 103, and 104.

In this way, the oil groove 9 is configured to drip the lubricating oil from the low-gear among the transmission gears on the counter shaft 4, and the lubricating oil is sequentially dripped to the high-gear as the vehicle speed increases, the rotation of the final driven gear 60 increases, and the flow rate of the lubricating oil held in the oil groove 9 increases. Therefore, it is possible to preferentially lubricate the gears for the low range during low-speed running and efficiently supply lubricating oil to the transmission gear stage used in accordance with transition from low-speed running to high-speed running.

The dropping holes 101 and 102 are formed in a curved bottom wall 93d and a transition bottom wall 93f having circular arc shapes along the outer peripheral shapes of the 2 nd intermediate gear 41 and the 3 rd intermediate gear 42, and the dropping holes 101 and 102 are close to the gears 41 and 42. Therefore, the lubricating oil dropped from the dropping holes 101 and 102 can reliably and efficiently reach the 2 nd intermediate gear 41 and the 3 rd intermediate gear 42.

Further, the lubricating oil that rotates together with the 2 nd intermediate gear 41 or the 3 rd intermediate gear 42 can be scraped off by the outer peripheral side wall portion 93h (including the inclined portion 93i) that continuously rises upward in front of the curved bottom wall portion 93d and the transition bottom wall portion 93 f. Accordingly, the amount of the lubricating oil that rotates together with the 2 nd intermediate gear 41 or the 3 rd intermediate gear 42 can be limited, and reduction in the rotational resistance due to the viscosity of the lubricating oil can be achieved.

The dropping hole 103 and the dropping hole 104 are formed in the circular arc-shaped upper-stage bottom wall portion 94a along the outer peripheral shape of the 4 th intermediate gear 43 and the 5 th intermediate gear 44, and the dropping holes 103 and 104 are close to the respective gears 43 and 44. Therefore, the lubricating oil dropped from the dropping holes 103 and 104 can reliably and efficiently reach the 4 th intermediate gear 43 and the 5 th intermediate gear 44.

Further, the lubricating oil that rotates together with the 4 th intermediate gear 43 or the 5 th intermediate gear 44 can be scraped off by the front side wall portion 94d that rises upward continuously to the front of the upper-stage bottom wall portion 94 a. Accordingly, the amount of the lubricating oil that rotates together with the 4 th intermediate gear 43 or the 5 th intermediate gear 44 can be limited, and reduction in the rotational resistance due to the viscosity of the lubricating oil can be achieved.

In the present embodiment, the dropping hole 100 is formed in the flat bottom wall 91b, but may be formed in a curved bottom wall 91c located on the front side of the flat bottom wall 91 b. The curved bottom wall 91c is in the shape of an arc along the outer periphery of the 1 st intermediate gear 40, and by providing the dropping hole 100 in the curved bottom wall 91c, the lubricating oil can be dropped from a position further close to the 1 st intermediate gear 40.

The lubricating oil that rotates together with the 1 st intermediate gear 40 or the 1 st shift sleeve 46 (including the reverse intermediate gear 47) can be scraped off by the front side wall portion 91f that rises upward continuously to the front of the curved bottom wall portion 91 c. Thus, the amount of lubricating oil that rotates together with the 1 st intermediate gear 40 or the 1 st shift sleeve 46 can be limited, and reduction in rotational resistance due to viscosity of the lubricating oil can be achieved.

In the transmission case 20, the lubricating oil flows not only to the transmission gear mechanism 10 by being guided by the oil grooves 9 but also to the respective positions to lubricate the internal shift mechanism 8 and the like. In the internal shift mechanism 8, the shift forks 81b, 82b, and 83b are plate-shaped having a horizontal extension, and therefore, are configured to easily receive the lubricating oil scattered from the transmission gears of the transmission gear mechanism 10. As a result, the lubricating oil is easily accumulated in the shift forks 81b, 82b, and 83b and falls.

Here, the front oil passage portion 93b of the oil groove 9 passes through the lower sides of the shift forks 81b, 82b, and 83b stacked in the vertical direction (see fig. 7 and 10). Therefore, the lubricating oil falling downward from the shift forks 81b, 82b and 83b is collected by the oil groove 9 and prevented from reaching the lower intermediate shaft 4 side. If the lubricating oil is dropped from the oil grooves 9 to supply an appropriate amount of lubricating oil to the transmission gears on the counter shaft 4, the lubricating oil dropped from the shift forks 81b, 82b, and 83b may adhere to the transmission gears, and an excessive viscous resistance may be generated. The oil groove 9 is disposed between the internal shift mechanism 8 and the transmission gear mechanism 10 at a position in the vertical direction, and thus functions to prevent such excessive lubricating oil from adhering to the transmission gear mechanism 10.

Further, since the oil grooves 9 form oil passages so as to surround the front, rear, left, and right sides of the shift device 7, the lubricating oil that has splashed from the oil grooves 9 to the inside of the through portions 96 can be used for lubricating the shift device 7 inserted into the through portions 96. In particular, the performance of the shift or selection operation can be improved by reducing the sliding resistance of the shift select shaft 70 directly received by the shaft support portion 29 in the left housing 22 or by improving the lubricity of the operation of the cam member 74. As shown in fig. 7, the upper end position of the inner peripheral side wall portion 93g of the 2 nd oil passage 93 is substantially the same as the height position of the upper surface of the shaft support portion 29, the upper end position of the inner peripheral side wall portion 92d of the 1 st oil passage 92 is substantially the same as the height position of the upper side plate 77a of the interlock plate 77, and the lubricating oil that has passed over the respective inner peripheral side wall portions 93g, 92d is supplied to the shaft support portion 29 or the cam member 74.

The oil groove 9 in which the oil passage is branched so as to surround the shift device 7 is also superior in rigidity, compared to an elongated oil groove extending in the left-right direction without branching. In particular, the partition wall 91g that separates the inflow portion 91 from the 2 nd oil passage 93 is high in the vertical direction, and contributes greatly to improvement in the sectional strength of the oil passage branch portion of the oil groove 9. The flow straightening ribs 91i also contribute to smooth flow of the lubricating oil from the trap portion 90 to the inflow portion 91 and to increase the rigidity in the vicinity of the boundary between the trap portion 90 and the inflow portion 91. The flow-straightening ribs 92f and 93j appropriately control the flow of lubricating oil from the 1 st oil passage 92 and the 2 nd oil passage 93 to the confluence portion 94, and contribute to improvement in rigidity in the vicinity of the downstream ends of the 1 st oil passage 92 and the 2 nd oil passage 93. Moreover, the oil groove 9 also achieves the assurance of rigidity by partially changing the depth or shape of the bottom wall.

The front oil passage portion 93b or the confluence portion 94 of the oil groove 9 has a shape with a small vertical dimension (a low side wall) so as to be disposed in a vertically narrow space between the internal shift mechanism 8 and the transmission gear mechanism 10 on the front side of the shift select shaft 70. On the other hand, on the front side of the shift select shaft 70, since the shafts of the transmission gear mechanism 10 and the internal shift mechanism 8 are arranged in parallel in the front-rear direction or the shift forks 81b, 82b, and 83b extend in the front-rear direction, a space having a certain degree of size in the front-rear direction is obtained. Therefore, the front oil passage portion 93b or the junction portion 94 has a length (width) in the front-rear direction larger than a height (depth) in the vertical direction, thereby securing a passage cross-sectional area (capacity) (see fig. 2, 4, 5, and 7).

The shift select shaft 70 is disposed rearward of the left housing 22. Therefore, on the rear side of the shift select shaft 70, the rear oil passage portion 92a of the oil groove 9 has a shape with a small dimension in the front-rear direction (a narrow gap between the inner peripheral side wall portion 92d and the outer peripheral side wall portion 92 e) so as to be disposed in a space between the shift select shaft 70 and the rear wall portion 24c of the left housing 22, which is narrow in the front-rear direction (see fig. 7). On the other hand, on the rear side of the shift select shaft 70, since there is no spatial restriction by the internal shift mechanism 8 or the transmission gear mechanism 10, the rear oil passage portion 92a ensures a passage cross-sectional area (capacity) by making the height in the vertical direction (the depth of the rear oil passage portion 92a) larger than the length in the front-rear direction (the width of the rear oil passage portion 92 a). Specifically, the rear oil passage portion 92a is disposed in a space in the vertical direction that is obtained between the upper wall portion 24a and the shaft support portion 29. The outer peripheral side wall portion 92e of the 1 st oil passage 92 rises vertically along the rear wall portion 24c, and the upper end thereof is disposed close to the upper wall portion 24 a.

In this way, in the oil groove 9, the branched 1 st oil passage 92 and 2 nd oil passage 93 are disposed in a space-saving manner without interfering with surrounding members, and both downsizing and high lubrication performance of the transmission 2 can be achieved.

The oil groove 9 includes a portion functioning as an intermediate reservoir portion for storing lubricating oil in a region on the right side of the shift select shaft 70 and on the left side of the final driven gear 60. This region is located between the differential device 6 (final driven gear 60) and the shift device 7 (shift select shaft 70) that occupy a large range in the vertical direction, and it is easy to secure a space in the vertical direction, and the degree of freedom in setting the shape of the oil groove 9 is high. Specifically, the oil catch tank 93a is provided with the inflow portion 91 and the 2 nd oil passage 93 as an intermediate reservoir portion having a depth capable of storing lubricating oil.

The oil collection tank 93a is located adjacent to the right side of the through portion 96 through which the shift select shaft 70 is inserted. At this position in the left housing 22, the shaft supporting portion 29 is not present on the right side of the shaft supporting portion 29 for supporting the shift select shaft 70, and therefore, the restriction of the lower space is small compared to the rear space of the shift select shaft 70. Therefore, the lower bottom wall 93c of the oil catch tank 93a can be made to bulge downward compared with the bottom wall 92c, the upper bottom wall 93e, and the like of the rear oil passage portion 92a (see fig. 7). That is, the oil collection tank 93a is disposed in a region rightward of the shaft support portion 29 and leftward of the 1 st shift fork 81c, and a bottom wall (lower bottom wall portion 93c) thereof enters between the rear wall portion 24c and the 2 nd and 3 rd intermediate gears 41, 42 at the rear thereof.

This is based on the following reasons: unlike the forward oil passage portion 93b or the merging portion 94 located directly above the intermediate shaft 4, the lower bottom wall portion 93c of the oil catch tank portion 93a is located on the rear side of the intermediate shaft 4, and therefore the space downward is not restricted by the transmission gear mechanism 10. Therefore, the lower-stage bottom wall portion 93c of the oil collection tank portion 93a can bulge downward than the upper-stage bottom wall portion 93e of the front oil passage portion 93b or the upper-stage bottom wall portion 94a of the merging portion 94 (see fig. 7).

The lower bottom wall portion 93c bulges downward than the flat bottom wall portion 91b of the inflow portion 91 located on the upstream side of the oil collection tank portion 93 a. The flat bottom wall portion 91b is formed in the bottom wall of the oil groove 9 at a position next to the 2 nd lower position of the lower bottom wall portion 93c (see fig. 16). Thus, the lower bottom wall portion 93c is formed at the lowermost position in the bottom wall of the oil groove 9, and the depth of the lower bottom wall portion 93c ensures the capacity of the oil catch tank portion 93 a.

However, the oil collection tank portion 93a extends forward to be connected to a forward oil passage portion 93b passing forward of the shift select shaft 70. Since the forward extending portion of the oil collection tank portion 93a is vertically overlapped with the 2 nd intermediate gear 41 and the 3 rd intermediate gear 42, if the height position of the lower bottom wall portion 93c is maintained, interference occurs with the 2 nd intermediate gear 41 and the 3 rd intermediate gear 42. Therefore, at the forward projecting portion of the oil collection tank portion 93a, the bottom wall is formed by the curved bottom wall portion 93d that becomes gradually shallower as going forward, preventing interference with the 2 nd and 3 rd intermediate gears 41, 42.

Further, a transition bottom wall portion 93f is provided at a boundary portion between the oil collection tank portion 93a and the front oil passage portion 93b, and the transition bottom wall portion 93f smoothly connects a curved bottom wall portion 93d and an upper stage bottom wall portion 93e, which have different curvatures from each other. Therefore, the lower-stage bottom wall portion 93c and the upper-stage bottom wall portion 93e, which are separated by a vertical difference, can be smoothly connected by the curved bottom wall portion 93d and the transition bottom wall portion 93f, and the lubricating oil can smoothly flow from the oil collection tank portion 93a to the forward oil passage portion 93 b.

The inflow portion 91 is located right behind the oil collection tank portion 93a, the inflow portion 91 is disposed in a region rightward of the shaft support portion 29 and leftward of the final stage driven gear 60, and bottom walls (a flat bottom wall portion 91b and a curved bottom wall portion 91c) thereof enter between the 1 st intermediate gear 40 and the 1 st shift fork 81c and the rear wall portion 24c at the rear thereof.

By providing the oil collection tank portion 93a and the inflow portion 91 as the intermediate reservoir portion having the bottom wall positioned below the bottom wall portion 90a (the 1 st bottom wall portion) of the trap portion 90 and the bottom wall portion 95a (the 2 nd bottom wall portion) of the supply end portion 95 in this way, the oil groove 9 not only allows the lubricating oil to flow therethrough, but also has a function of reserving the lubricating oil (an oil amount adjusting function during traveling or engine operation). Since the oil groove 9 holds a predetermined amount of lubricating oil, the amount of lubricating oil stored in the lower portion of the transmission case 20 is relatively small while the lubricating oil is circulating while the engine 1 is driven or the vehicle is running. Therefore, even when the amount of lubricating oil in the transmission case 20 is set to be large in consideration of the initial lubrication from the engine stop state, the amount of lubricating oil (the height of the liquid surface) that the gears in the transmission case 20 are immersed into is suppressed in the state where the engine 1 is driven or running, and the stirring resistance caused by stirring of the lubricating oil at the time of rotation of the gears can be reduced. That is, the operating resistance in the transmission 2 can be reduced, and the fuel efficiency can be improved by efficient power transmission.

The oil groove 9 has a higher oil amount adjusting function by increasing the amount of lubricant held by the oil passage by the above-described branching structure of the oil passage in addition to the intermediate reservoir portion such as the oil collection tank portion 93a or the inflow portion 91.

Further, since the oil groove 9 itself has a function of storing the lubricating oil, it is not necessary to provide a large-sized collection tank separately from the oil groove 9. The conventional sump tank is omitted by the oil groove 9, and a space-saving lubrication structure with a small number of components can be realized. Alternatively, even if the collection tank is provided, the collection tank may be provided in a small size, and thus the degree of freedom of arrangement is improved. The oil collection tank portion 93a and the inflow portion 91 are disposed by effectively utilizing a dead space in the vehicle width direction between the large-diameter final driven gear 60 and the vertically long shift device 7, and are excellent in space efficiency. These elements can reduce the size of the entire transmission.

In addition, the configuration in which the oil groove 9 has a function of storing lubricating oil is superior to the configuration in which a separate collection tank is provided, in terms of: the storage of the lubricating oil and the supply to each part can be smoothly connected, and the circulation state and the supply amount of the lubricating oil can be easily and accurately controlled. That is, since the oil collection tank portion 93a and the inflow portion 91 are present on the oil path continuous with the end opening 95f that supplies the lubricating oil to the shaft end of the input shaft 3 or the respective dropping holes 100, 101, 102, 103, and 104 that drop the lubricating oil to the respective gears on the intermediate shaft 4, there is an advantage that a proper amount of lubricating oil can be supplied to these lubricating oil supply portions without delay.

Further, in a state where the engine 1 is stopped and the circulation of the lubricating oil in the transmission case 20 is stopped, the lubricating oil drops downward from the drain hole 105 or the dropping hole 100 provided in the bottom wall (the lower-stage bottom wall portion 93c, the flat bottom wall portion 91b) of the intermediate reservoir, and the oil groove 9 does not continue to hold an excessive amount of lubricating oil. In particular, since the drain hole 105 is formed in the lowermost lower bottom wall portion 93c in the oil groove 9, the lubricating oil can be reliably drained from the oil catch tank portion 93 a. Gears and the like constituting the transmission gear mechanism 10 are not disposed below the discharge hole 105, and the lubricating oil falling from the discharge hole 105 returns to the oil reservoir at the lower portion of the transmission case 20 without adhering to the transmission gears and the like. Therefore, in the engine stop state, a sufficient amount of lubricating oil is secured in the lower oil reservoir, and the risk of insufficient lubricating oil does not occur at the next start of the engine.

The flat bottom wall 91b of the inflow portion 91 adjacent to the oil collection tank portion 93a via the partition wall 91g bulges downward than the bottom wall 90a of the trap portion 90 or the bottom wall 92c of the 1 st oil passage 92. The depth of the flat bottom wall 91b ensures the capacity of the inflow portion 91. The inflow portion 91 can store the lubricating oil in a height range from the flat bottom wall portion 91b to the lower end of the notch 91 j. That is, the inflow portion 91 adjacent to the upstream side of the oil catch tank portion 93a also functions as an auxiliary intermediate reservoir portion capable of storing a predetermined amount of lubricating oil.

An inclined bottom wall 91d smoothly connecting from the flat bottom wall 91b to the bottom wall 92c is provided at the boundary between the inflow portion 91 and the 1 st oil passage 92. The inclined bottom wall 91d allows the lubricating oil reserved in the inflow portion 91 to smoothly flow to the 1 st oil passage 92.

The inflow portion 91 projects forward less than the oil collection tank portion 93a, but a part of the front side of the inflow portion 91 vertically overlaps the 1 st intermediate gear 40 and the 1 st shift sleeve 46, and therefore, if the height position of the flat bottom wall portion 91b is maintained, it interferes with the 1 st intermediate gear 40 and the 1 st shift sleeve 46. Therefore, at the front edge portion of the inflow portion 91, the bottom wall is formed by the curved bottom wall portion 91c that becomes gradually shallower toward the front, and interference with the 1 st intermediate gear 40 and the 1 st shift sleeve 46 is prevented.

When the lubricant oil is accumulated to the lower end position of the notch 91j in the inflow portion 91, the lubricant oil flows down to the oil collection tank portion 93a through the notch 91 j. Since the vertical height difference from the lower end of the notch 91j to the lower bottom wall portion 93c is large (see fig. 16), the lubricating oil can be forced to flow from the inflow portion 91 to the 2 nd oil passage 93. The flow rate or the flow force of the lubricating oil from the inflow portion 91 to the 2 nd oil passage 93 can be appropriately adjusted by changing the shape or the position of the notch 91 j. That is, the amount of the lubricating oil passing through the notch 91j can be limited by the width of the notch 91j, and the lubricating oil can be accumulated in the inflow portion 91 to a position higher than the lower end position of the notch 91j in accordance with the relationship between the inflow amount into the trap portion 90 and the outflow amount into the 1 st oil passage 92.

As described above, when the oil groove 9 is viewed in plan (see fig. 12), the 2 nd oil passage 93 extends on an extension line of the opening direction of the notch 91j (diagonally left forward as viewed from the inflow portion 91 side). Therefore, the lubricating oil can smoothly flow from the notch 91j to the 2 nd oil passage 93. The bottom wall of the 2 nd oil passage 93 is formed by connecting a deeper lower bottom wall portion 93c and a shallower upper bottom wall portion 93e by a smoothly curved bottom wall portion 93d and a transition bottom wall portion 93f, and the bottom wall shape also contributes to smooth flow of the lubricating oil.

As described above, the lubrication structure of the transmission according to the present embodiment includes the oil groove 9 in which the holding capacity of the lubricating oil is increased by the provision of the intermediate reservoir portion or the branching structure of the oil passage. Accordingly, the lubricating oil at the lower portion of the transmission case 20 in the engine-driven state can be set to an appropriate amount, and the stirring resistance of the lubricating oil against the rotation of the gears can be reduced, thereby improving the driving efficiency and the fuel efficiency. Since the oil groove 9 stores the lubricating oil, it is possible to reduce the cost and labor for separately installing a large-sized catch tank, and contribute to downsizing of the transmission and improvement of space efficiency inside the transmission case 20.

In the lubricating structure of the transmission according to the present embodiment, the oil groove 9 includes the through portion 96 that penetrates in the vertical direction, and a part of the shift device 7 is located in the through portion 96. With this configuration, the lubricating performance (the degree of freedom of the flow rate or the lubricating oil supply position) of the oil groove 9 can be improved without interfering with the shift device 7. Further, since the oil passage structure is branched through the through portion 96, an effect such as improvement in rigidity of the oil groove 9 can be obtained.

The present invention is not limited to the above embodiment, and can be implemented by being variously modified. In the above-described embodiments, the size, shape, and the like shown in the drawings are not limited thereto, and can be appropriately modified within the range in which the effects of the present invention are exhibited. Further, the present invention can be implemented by appropriately changing the configuration without departing from the scope of the object of the present invention.

For example, in the above embodiment, the height positions of the 1 st oil passage 92 and the inflow portion 91 are made different from the height position of the 2 nd oil passage 93, and then the lubricating oil is made to flow into the 2 nd oil passage 93 through the notch 91j formed in the partition wall portion 91g which is the side wall of the inflow portion 91. In contrast to this configuration, the following oil grooves can be used: the height of the 2 oil passages is made equal at the branching portion, and the 2 oil passages are branched by the partition wall.

The notch 91j of the above embodiment is rectangular with an open upper end, but it is also possible to introduce the lubricating oil to the branched oil passages by a notch having a shape other than a rectangle or a through hole having a closed shape with a non-open peripheral edge.

In the above embodiment, the oil catch tank portion 93a is provided in the upstream portion of the 2 nd oil passage 93 on the front side through the shifting device 7, but an intermediate reservoir portion may be provided at a different position on the 2 nd oil passage 93 or on the 1 st oil passage 92.

One or more intermediate reservoir portions may be provided in the oil groove, and when a plurality of intermediate reservoir portions are provided, the capacity, positional relationship, and the like between the intermediate reservoir portions can be arbitrarily set. For example, in the oil groove 9 of the above embodiment, the intermediate reservoir portions satisfying the condition that the bottom wall is located below the bottom wall portion 90a of the trap portion 90 and the bottom wall portion 95a of the supply end portion 95 are the oil collection tank portion 93a (lower bottom wall portion 93c) and the inflow portion 91 (flat bottom wall portion 91 b). In contrast to this configuration, the bottom wall position of the inflow portion 91 may be increased, and only the oil catch tank 93a may be used as the intermediate reservoir. Alternatively, an intermediate reservoir may be provided separately from the 1 st oil passage 92.

The configuration of the transmission gear mechanism and the like in the transmission is not limited to the above embodiment. For example, the transmission gear mechanism 10 of the above embodiment includes the input shaft 3, the intermediate shaft 4, and the reverse shaft 5 as the transmission shafts, but may be applied to a type of transmission in which the number of transmission shafts and the functions of the transmission shafts are different. Further, although the oil groove 9 of the above embodiment is an oil groove for introducing the lubricating oil into the axial hole 3c at the shaft end of the input shaft 3 and dropping the lubricating oil onto the speed change gears on the counter shaft 4, it may be configured such that the lubricating oil is introduced into the axial hole 4c at the shaft end of the counter shaft 4 and the lubricating oil is dropped onto the speed change gears on the input shaft 3, depending on the configuration of the transmission.

Industrial applicability of the invention

As described above, the present invention has the following effects: the configuration can optimize the flow state of the lubricating oil in the transmission and improve the lubricating performance of the lubricated parts with a simple and space-saving configuration, and is particularly useful for transmissions that require downsizing and low cost.

Claims (16)

1. An oil groove of a transmission, which constitutes an oil passage surrounded by a bottom wall and a side wall protruding upward from the bottom wall, includes: a trap portion for collecting the lubricating oil carried up from the lower portion of the transmission; and a supply end portion that supplies lubricating oil to a shaft end of a speed change shaft that supports the speed change gear,

the oil groove of the transmission described above is characterized in that,

an intermediate reservoir is provided between the trap portion and the supply end portion, the bottom wall of the intermediate reservoir is positioned lower than a 1 st bottom wall portion and a 2 nd bottom wall portion, the 1 st bottom wall portion is the bottom wall of the trap portion, and the 2 nd bottom wall portion is the bottom wall of the supply end portion.

2. The transmission oil gallery of claim 1,

the bottom wall of the intermediate storage portion is a 3 rd bottom wall portion, and the 3 rd bottom wall portion bulges downward from the bottom wall adjacent to the upstream side and the downstream side of the intermediate storage portion.

3. The transmission oil gallery of claim 1,

the plurality of intermediate storage portions are located at different positions in the vertical direction of the bottom wall.

4. The transmission oil gallery according to any one of claims 1 to 3,

the transmission is provided with: a shift fork supported by the shift shaft above the shift shaft; and a shift fork supported by the shift fork and configured to shift a plurality of engagement relationships of the transmission gears by axial movement of the shift shaft,

the oil passage passes through a lower side of the shift fork above the shift gear.

5. The transmission oil gallery of claim 4,

the side wall has a slope inclined with respect to an axial direction of the shift shaft, and the slope can abut against a tip end of the shift shaft when the transmission is assembled.

6. The transmission oil gallery according to any one of claims 1 to 3,

at least a part of the oil passage is located above the transmission gear,

a drop hole for dropping the lubricant from the oil passage to the transmission gear is provided in a portion of the bottom wall located above the transmission gear.

7. The transmission oil gallery of claim 6,

a plurality of dropping holes for dropping the lubricant to the plurality of transmission gears,

the position of the bottom wall provided with the dropping hole is located lower as the transmission gear to be dropped of the lubricating oil is closer to the low speed side.

8. The transmission oil gallery of claim 6,

the portion of the bottom wall located above the transmission gear has an arc-shaped portion along the outer periphery of the transmission gear, and the drop hole is formed in the arc-shaped portion.

9. An oil groove of a transmission, which constitutes an oil passage surrounded by a bottom wall and a side wall protruding upward from the bottom wall, includes: a trap portion for collecting the lubricating oil carried up from the lower portion of the transmission; and a supply end portion that supplies lubricating oil to a shaft end of a speed change shaft that supports the speed change gear,

the oil groove of the transmission described above is characterized in that,

the transmission device has a through portion that penetrates in the vertical direction, and a part of a shifting device that transmits a shifting operation of the transmission is located in the through portion.

10. The transmission oil gallery of claim 9,

the oil passage from the trap portion to the supply end portion is branched into a 1 st oil passage and a 2 nd oil passage, and the penetration portion is sandwiched by the 1 st oil passage and the 2 nd oil passage,

a notch formed in the side wall is provided between the 1 st oil passage and the 2 nd oil passage, and the lubricating oil flows out through the notch.

11. The transmission oil gallery of claim 10,

the bottom wall of the 1 st oil passage and the bottom wall of the 2 nd oil passage are different in position from each other in the vertical direction, and the lubricating oil flows from the upper oil passage side of the 1 st oil passage and the 2 nd oil passage to the lower oil passage side of the 1 st oil passage and the 2 nd oil passage through the notch.

12. The transmission oil gallery according to any one of claims 9 to 11,

the transmission is provided with: a shift fork supported by the shift shaft above the shift shaft; and a shift fork supported by the shift fork and configured to shift a plurality of engagement relationships of the transmission gears by axial movement of the shift shaft,

the oil passage passes through a lower side of the shift fork above the shift gear.

13. The transmission oil gallery of claim 12,

the side wall has a slope inclined with respect to an axial direction of the shift shaft, and the slope can abut against a tip end of the shift shaft when the transmission is assembled.

14. The transmission oil gallery according to any one of claims 9 to 11,

at least a part of the oil passage is located above the transmission gear,

a drop hole for dropping the lubricant from the oil passage to the transmission gear is provided in a portion of the bottom wall located above the transmission gear.

15. The transmission oil gallery of claim 14,

a plurality of dropping holes for dropping the lubricant to the plurality of transmission gears,

the position of the bottom wall provided with the dropping hole is located lower as the transmission gear to be dropped of the lubricating oil is closer to the low speed side.

16. The transmission oil gallery of claim 14,

the portion of the bottom wall located above the transmission gear has an arc-shaped portion along the outer periphery of the transmission gear, and the drop hole is formed in the arc-shaped portion.

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