JP2563880Y2 - Work vehicle transmission - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The invention relates to a transmission for a working vehicle such as a tractor.
More specifically, the present invention relates to a structure of an operation unit of the transmission.

(B) Conventional technology Generally, a working vehicle, for example, a tractor has a body supported by wheels, and has an engine in front of the body. The power of the engine is transmitted to the wheels via a transmission, and , Are also transmitted to the PTO shaft system in the transmission. The transmission includes a traveling system that drives wheels and a transmission that performs a shift operation of the PTO shaft system.

(C) Problems to be Solved by the Invention In the above-described transmission, for example, an O-ring for preventing oil leakage to the outside of the transmission case is mounted on an operation shaft of a transmission arm of a PTO shaft system, for example. In order to mount the O-ring, first, the operation shaft is directed from the inside to the outside of the transmission case, and is inserted into the case wall.
The operating shaft is moved in the axial direction so that the O-ring groove of the operating shaft on which the ring is mounted is exposed to the outside of the transmission case, and then the O-ring groove is passed while passing the O-ring through the exposed operating shaft. And the operating shaft is pulled back inside the case, and the O-link is mounted. Thus, O
When the ring is mounted, an O-ring mounting space is required inside the transmission case, so that the width of the transmission case in the left-right direction is increased, and the transmission case itself is also enlarged.

Accordingly, an object of the present invention is to provide a transmission for a working vehicle that can secure an O-ring mounting space without increasing the width of a transmission case in the left-right direction.

(D) Means for Solving the Problems The present invention has been made in view of the above circumstances, and, for example, as shown with reference to FIG. 1, a mission case (9)
A work gear having a transmission gear (29) movably supported along a shaft (17) supported by the transmission case (9), wherein a side wall (93) of the transmission case (9) is provided. An operation shaft (32) rotatably and axially movably supported in a hole (93a) formed in the transmission case, and the operation shaft (32) is integrally fixed to the operation shaft (32), and the side wall ( 93) and projecting toward the side wall (93) of the transmission case (9).
a) and a shift arm (31) for operating the shift gear (29); a seal groove (32b) formed in an outer peripheral portion of the operating shaft (32) near an outer wall; 93), the shifting arm (31) is moved in the axial direction of the operating shaft (32), and when the sealing groove (32b) is exposed outside the side wall of the transmission case (9), the shifting arm (31) is moved. (3
A hole (93c) for receiving the overhang (31a) of 1),
It is characterized by having.

(E) Action Based on the above configuration, for example, to attach an O-ring or the like to the operation shaft (32) rotatably and axially inserted into the side wall (93) of the transmission case (9), The operation shaft (32) of the case (9) is moved axially outward from the case (9), and is moved into the seal groove (32b) formed in the outer peripheral portion of the operation shaft (32) near the outer wall. This is done by inserting and locking. At this time, the shifting arm (31) that moves together with the operation shaft (32) has a projecting portion (31) projecting toward the side wall (93) of the transmission case (9).
a), and when the seal groove (32b) is exposed outside the side wall of the transmission case (9), the overhang (31a) is formed on the wall (93) of the case (9). Since it is received in the hole (93c), there is no need to form a mounting space such as an O-ring in the width direction of the transmission case (9).

(F) Effect of the present invention As described above, according to the present invention, the hole (93c) formed from the side wall (93) of the transmission case (9) has:
Since the transmission arm (31) is received, it is not necessary to form a base required for mounting an O-ring or the like in the width direction of the case (9). Can be narrower,
The mission case (9) can be reduced in size.

The reference numerals in parentheses are for referring to the drawings, and do not limit the configuration.

(G) Example Hereinafter, an example of the present invention will be described with reference to the drawings.

As shown in FIG. 4, the tractor 1 has a traveling body 5 supported by a front wheel 2 and a rear wheel 3, and an engine 6 is mounted on a front portion of the traveling body 5, and An operation seat 7 is arranged at the rear of 5. A transmission case 9 is disposed below the engine 6, and a rear axle case 55 is disposed behind the transmission case 9.

On the other hand, as shown in FIG. 3, the power from the engine 6 is transmitted to the transmission main shaft 10 in the transmission case 9 via the clamp 4. The transmission main shaft 10 is provided with a gear 101 and transmissions 102 and 103 from the engine 6 side, and is supported by bearings. Further, an auxiliary transmission shaft 105 is coaxially arranged behind the transmission main shaft 10, and an auxiliary transmission 107 is installed on the shaft 105. The gear 8 meshing with the gear 101 is a PTO drive shaft.
The drive shaft 11 is connected to a PTO drive shaft 13 via a joint 12 at the rear thereof. The power shifted by the transmissions 102 and 103 is transmitted to the counter shaft 110 via gears A, B, C, or D provided on the counter shaft 110, and the auxiliary transmission shaft is transmitted via gears 111a and 111b. The transmission is transmitted to the pinion shaft 112 when the auxiliary transmission 107 meshes with the gear E or F. The power to the pinion shaft 112 is transmitted to the differential device 115 via the drive pinion 113, and further transmitted to the rear wheel 3.

On the other hand, above the rear wall 91 of the transmission case 9,
As shown in FIG. 2, a PTO drive shaft 13 is supported and installed by bearings 15 and 16, a gear 21 is fixed to the drive shaft 13, and a drive gear 22 is attached to the drive shaft 13. Only the slide is freely fitted to the spline shaft 13a. Drive gear 2
2 is always engaged with the gear 25 and has an inner arm 3 described later.
When the drive gear 22 is slid at 7, the idle gear 30 also meshes. Further, a cap 14 is sealed in a hole 91a of the rear wall 91 where the PTO drive shaft 13 is installed, thereby preventing oil leakage in the transmission case 9.

In the transmission case 9, the PTO shaft 17 is supported by bearings 19, 20.
, And the bearing 20 is inserted and locked on the inner wall 92, respectively. The PTO shaft 17 is disposed below the PTO drive shaft 13, and the sleeve nut 18 is
(See FIGS. 5 and 6). The sleeve nut 18 is used as a stopper to prevent the PTO shaft 17 from coming off the bearing 20. The sleeve nut 18 is fastened to the other end of the PTO shaft 17 so as to enter a hole 92a formed in the inner wall 92 of the transmission case 9. Further, a cutout 92b into which the convex adapter 62 can be inserted is formed in the hole 92a, and a differential ring gear 61 is arranged near the cutout 92b.

The PTO shaft 17 has gears 23, 25, a boss 26, and a sleeve 27.
The transmission gear 29 and the idle gear 30 are loosely fitted to each other, and one end of the PTO shaft 17 projects from the rear wall 91. The transmission gear 29 has a gear 23 and a gear 25 on the PTO shaft 17, and a sleeve 27 is supported between the gears 23 and 25 via a boss 26 so as to be slidable in the axial direction. Lock portions 23a, 25a for locking with the dog clutch 27a are formed on the side surfaces of the gears 23, 25 on the sleeve 27 side, and the dog clutch 27a is formed on both end surfaces of the sleeve 27. Have been. The transmission gear 29 is
The shift operation is performed by sliding the sleeve 27 by the operation of the shift arm 31 described later and locking the sleeve 27 to the locking portion 23a or 25a.

As shown in detail in FIG. 1, an operation shaft 32 to which the speed-change arm 31 is fixed is provided in a support hole 93a of a side wall 93 of the case 9.
Are supported so as to be freely rotatable and axially movable, and the operation shaft 32 is formed in a sleeve shape. The speed change arm 31 integrally fixed to the operation shaft 32 is disposed at a distance l from the side wall 93 and is formed so as not to interfere with the gears 23 and 25. Further, at the tip of the shifting arm 31, there is provided an arm 31 a which is a projecting portion having a shape projecting toward the side wall 93 of the transmission case 9, and the arm portion 31 a has a yoke for operating the sleeve 27 of the shifting gear 29. 33 is attached by pin 35.

An arm shaft 36 is rotatably inserted into the operation shaft 32, and an inner arm 37 and a plate 39 are fixed to the arm shaft 36. A piece 40 for operating the drive gear 22 is attached to the inner arm 37, and a plate 39 is fixed to the arm shaft 36. The plate 39 is provided with a hole 39a for holding a position when the inner arm 37 slides the drive gear 22. On the upper part of the side wall 93, a locking member 41 for locking with the hole 39a is held in position by a plate 42 and fixed by a bolt 43. The locking member 41 has a pin 47 urged by a spring 46 in a pin holder 45.

A spline is formed on the stepped portion 32a of the operation shaft 32, and the operation arm 51 is engaged with the spline, and an outer peripheral portion of the operation shaft 32 near the outer wall, that is, the stepped Groove 32b as a seal groove in the large diameter part on the part 32a side
The O-ring 50 is inserted and locked in the groove 32b. An operation arm 52 is fixed to an arm shaft 36 in the operation shaft 32 with a spring pin 53. Note that a chamfer 93b is formed in the support hole 93a of the transmission case 9 so that the chamfer 93b can be inserted smoothly when the O-ring 50 is inserted.

A rear axle case 55 is attached to a side wall 93 below the operation shaft 32, and the case 55 and the side wall 93 form a gear chamber 56. In the gear chamber 56, a shaft 57 is supported by a bearing 59, and a large gear 60 is mounted on the shaft 57. And the side wall in the gear chamber 56
The hole 93c is formed in the hole 93c, and the hole 93c is formed in such a size that the arm portion 31a does not interfere when the operation shaft 32 is moved outward from the transmission case 9. . Since the hole 93c is formed in the side wall 93, the oil flows out from the hole 93c so that the rear axle case 5
5 can be prevented from being attached to the side wall 93 in an oil-tight manner.

Also, as shown in FIG.
A power steering box 140 is installed above the ceiling wall 86, and the power steering box 140 has a pipe 141 that penetrates the convex portion 86a of the ceiling wall 86.
Are arranged. In the front transmission case 80, the transmission main shaft 10 is supported by bearings 70 and 71. The bearing 71 has a hole 85 formed in an intermediate wall 85 of the case 80.
a, and a cap 139 is inserted into the hole 85a. Further, an oil chamber 86 is formed by sealing the hole 85 a with the cap 139, and a communication hole 85 b penetrating the oil chamber 86 is formed in the intermediate wall 85. The pipe 141 is close to the communication hole 85b, and the return oil of the power steering box 140 is discharged from the pipe 141. The transmission main shaft 10 is formed in a double structure by the main shaft 120 and the direct transmission main shaft 121. The spindle 120 is
The main shaft 120 is inserted into a tube-shaped direct transmission main shaft 121, and one of the main shafts 120 is supported by the bearing 71, and the other is supported by a bearing 72 in the direct transmission main shaft 121.
20 has bosses 122, 123, 125 and bearings 127, 129, 130, 1
Transmissions 102 and 103 are provided via 31. In the transmission 102, a sleeve 135 is slidably disposed between gears 132 and 133 via a synchronization ring.
The gear 35 is configured to always mesh with one of the gears 132 and 133. And, similarly to 102, the transmission 103
136, 137 and a sleeve 139 having a synchronization ring.

Further, the main shaft 120 is provided with a main oil passage 120a through which the return oil flows in the axial direction, and a branch oil passage 120b penetrates from an outer diameter portion of the main shaft 120 toward the main oil passage 120a. ing. Further, the bosses 122 and 125 are provided with oil passage holes 122a and 125 at portions substantially at the same positions as the branch oil passages 120b (places in sliding contact with the bearings 127 and 131).
Are provided with oil passage holes 1
23a and 123a are perforated.

The oil chamber 86 may be provided with a lanai 142, the liner 142 prevents oil from flowing out of the bearing 71 to the oil chamber 86, and the liner 142 has an outer diameter of the bearing 71. And the inner diameter is the same as or slightly larger than the outer diameter of the inner ring of the bearing 71. Needless to say, the same operation as described above can be obtained even if the bearing 71 is changed to a bearing with a single-sided seal without providing the liner 142.

Since the present embodiment is configured as described above, when inserting the O-ring 50 into the groove 32b of the operation shaft 32 as shown in detail in FIG.

First, the arm shaft 3 is inserted into the support hole 93a of the transmission case 9.
Insert the operation shaft 32 into which the 6 has been inserted from the inside of the side wall 93, and insert the groove 32b.
Is moved so as to be exposed outward from the side wall 93. At this time, the shifting arm 31 moves together with the operation shaft 32, and the arm portion 31a is received in the hole 93c. At this time, the O-ring 50 is inserted into the groove 32b. And the operation axis 32
When the inward is drawn inward, the chamfer 93b is formed in the support hole 93a, so that the O-ring 50 does not catch on the side wall 93,
Can be inserted without scratching.

For this reason, even if the width of the transmission case 9 is not increased, the arm portion 31a is received by the distance 1 in the hole 93c, so that the width of the case can be reduced.

In order to assemble and disassemble the PTO shaft 17 at the time of assembly, maintenance, inspection, etc., as shown in detail in FIG.
Tighten the sleeve nut 18 on the 7 when assembling,
Must be loosened during disassembly. At this time, by inserting the adapter 62 into the notch 92b, the bottom surface 62a of the adapter 62 and one side surface 18a of the sleeve nut 18 are engaged to regulate the rotation of the nut 18. By turning the PTO shaft 17, the PTO shaft 17 can be assembled and disassembled. The shape of the notch and the adapter is not limited to the convex shape.If the rotation of the sleeve nut 18 can be restricted by inserting the adapter into the notch, the shape of the adapter is changed to a half-moon shape, and the notch is formed. It may be formed so as to be able to engage with the adapter.

Also, the transmission spindle 10 in the front transmission case 80
Bearings 127,129,130,131 of upper transmission 102,103 part
Is lubricated using the return oil of the power steering box 140. Power steering box
The return oil from 140 flows into the oil chamber 86 from the communication hole 85b via the pipe 141, and the oil filled in the oil chamber 86 flows into the main oil passage 120a of the main shaft 120. And the main oil passage 120a
The oil flowing into the boss 122, 123,
It flows through 125 oil passage holes 122a, 123a, 125a, and bearings 127, 1
Lubricate 29,130,131. Then, the oil is pumped up by an oil pump or the like through a filter (not shown), and flows again as described above to perform forced lubrication.

As described above, the return oil of the power steering box 140 is used to form a forced circulation flow path including the communication hole 85b, the oil chamber 86, the main oil passage 120a, the branch oil passage 120b, and the oil passage holes 122a, 123a, and 125a. As a result, reliable lubrication can be performed.

[Brief description of the drawings]

FIG. 1 is a rear sectional view showing a main part of the transmission according to the present invention, FIG. 2 is a side view showing the main part, FIG. 3 is a power transmission diagram schematically showing the transmission, and FIG. FIG. 5 is a side view showing a PTO shaft and a sleeve nut, FIG. 6 is a front view thereof, and FIG. 7 is a side sectional view showing a main shaft portion of the transmission. It is. 9: Mission case, 17: Shaft (PTO shaft), 2
9… Shift gear, 31… Shift arm, 32… Operation shaft, 93c
... Holes (holes).

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Michiya Endo 667, Iya-cho, Iza-cho, Higashi-Izumo-cho, Yatsuka-gun, Shimane Prefecture Inside Mitsubishi Agricultural Machinery Co., Ltd.

Claims (1)

(57) [Scope of request for utility model registration] 1. A work vehicle having a transmission gear inside a transmission case movably supported along a shaft supported by the transmission case, wherein the transmission gear is pivoted into a hole formed in a side wall of the transmission case. An operating shaft that is freely and axially movably supported, is integrally fixed to the operating shaft, is disposed close to the side wall of the transmission case, and projects toward the side wall of the transmission case. A speed change arm operating the speed change gear while having an overhanging portion; a seal groove formed in an outer peripheral portion of the operation shaft near an outer wall; and a shaft formed on the side wall, wherein the speed change arm is a shaft of the operation shaft. And a hole for receiving the overhang of the transmission arm when the seal groove is exposed to the outside of the side wall of the transmission case. Transmission of a working vehicle to be.