JPH0478501B2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a transmission device that controls the transmission of running power in a self-propelled working vehicle such as a tractor that has an engine mounted on one end of the machine body in the longitudinal direction. - Like a mounted mower, it can be installed on the bottom of the aircraft at an intermediate position in the longitudinal direction of the aircraft.
The present invention provides a transmission device that secures a large space for a mounted work machine.

Conventional technology A mower equipped with a mid-mount type work machine
In self-propelled work vehicles such as tractors, in order to secure space for the work equipment between the front and rear wheels, the ground clearance of the part of the machine located between the front and rear wheels is large, and the space between the front and rear wheels is large. A large interval is required. For this reason, driving transmissions have been made compact by connecting in series a relatively compact hydraulic transmission device and a compact mechanical transmission. In order to prevent the transmission from increasing the ground clearance between the front and rear wheels, it should be placed at the rear of the fuselage for vehicles with the engine mounted on the front of the fuselage, and towards the front of the fuselage for vehicles with the engine mounted on the rear of the fuselage. , they have been placed as close together as possible.

A typical example of this prior art is, for example, U.S. Patent No.
3528311 and No. 4304141, and efforts are made to locate the transmission device only between the left and right rear wheels as much as possible in a vehicle in which the engine is mounted on the front of the fuselage. In these conventional examples, a mechanical transmission is installed in a transmission case located at the rear of the aircraft body so that power is transmitted from the front side to the rear side of the transmission case, and a mechanical transmission is installed in the transmission case for driving the vehicle. The left and right rear wheels of the transmission case are supported by the rear end of the transmission case.

Problems to be Solved by the Invention Although the above-mentioned conventional technology secures the necessary ground clearance of the fuselage portion between the front and rear wheels, there is still a problem in securing a large longitudinal distance between the front and rear wheels. In other words, if you try to increase the above-mentioned front-to-back distance, you will have to shift the entire transmission mechanism consisting of the hydraulic transmission device and the transmission case, which are overlapped in the front and rear, toward the rear. This is because the distance between the wheels becomes too large, making it impossible for the vehicle to make sharp turns. It goes without saying that small turning is important for work vehicles such as mowers and tractors that are used in relatively narrow spaces.

The main object of this invention is to provide a transmission case for a self-propelled working vehicle in which an engine is mounted on one end of the vehicle in the front and rear directions, in which a hydraulic transmission device and a mechanical transmission that receive power from the engine are housed. For mid-mount type work machines, the hydraulic transmission device is located on the engine side and overlapped in the longitudinal direction of the machine, and the transmission case supports the left and right drive wheels. The objective is to provide a vehicle that simultaneously satisfies two mutually contradictory requirements, such as securing space for vehicles and improving the vehicle's turning ability.

Technical measures taken to solve the problem The present invention provides a self-propelled working vehicle in which an engine is mounted on one end of the machine body in the longitudinal direction.
a hydraulic transmission device 22 to which power is input from 111;
122 and transmission cases 15, 115 housing a mechanical transmission are provided so as to overlap each other in the longitudinal direction of the aircraft with the hydraulic transmission device located on the engine side. 16 and 116 are supported.

In such a transmission device, in order to solve the above-mentioned problems of the invention, the present invention provides intermediate walls 48, 14 integrally protruding from the inner surface of the transmission case 15, 115.
The motor shaft of the hydraulic transmission device 22, 122 is divided by 8 into a first chamber 49, 149 located on the side of the hydraulic transmission device 22, 122 and a second chamber 50, 150 located on the opposite side thereof. The input shafts 33, 133 connected to the input shafts 32, 132 are connected to the two chambers 49,
50, 149, 150 and located below the input shaft.
3 is provided in the second chamber 50, 150, and these two shafts 33, 5 are installed in the second chamber 50, 150.
Mechanical transmission 51,1 between 3,133,153
51, and a differential device 52, 152 that receives input transmission from the speed change shaft 53, 153 and transmits output in the left-right direction of the aircraft body is installed in the first chamber 49, 149 below the input shaft 33, 133. The left and right output shafts 35, 135 of this differential device 52, 152
The axle 3 of the left and right drive wheels 16, 116 described above.
9,139 between the transmission cases 15 and 1.
The hydraulic transmission device 22, 1 is fixedly supported by the hydraulic transmission device 15.
Left and right casings 3 extending in 22 directions
Technical measures were taken to connect the final gear reducer 40,140 in the 8,138.

Function Therefore, according to this invention, the hydraulic transmission device 2
Power is input from 2,122 into the transmission case 15,115 and is transmitted to the mechanical transmission 51,151 located on the side far from the engine within the transmission case. The signal is transmitted from the mechanical transmission device 51, 151 to the differential device 52, 152 on the side closer to the engine, and output to the left and right from within the transmission case on the side closer to the engine.
Furthermore, the left and right output shafts 35, 13 of the differential gear
5 and the axles 39, 1 of the left and right drive wheels 16, 116
The left and right casings 38, 1 are fixedly supported by the transmission case and extend toward the hydraulic transmission device 22, 122, that is, toward the engine side.
38, the left and right drive wheels 16, 11
6 will be arranged closer to the engine side than the left and right output shafts 35, 135 positions.

Therefore, the distance between the wheels provided on the fuselage on the engine side and the driving wheels, that is, the distance between the front and rear wheels, is reduced, and the tight turning performance of the vehicle is improved.

The above-mentioned left and right casings 38, 138 extending toward the hydraulic transmission devices 22, 122 house only the final gear reduction device 40, 140, so they can be kept within the longitudinal width occupied by the hydraulic transmission device. , there is no need to increase the longitudinal width of the transmission device as a whole. Therefore, when viewed in the longitudinal direction of the aircraft, the inside of the transmission device has the same longitudinal width as the conventional structure.
Space for mounted work equipment is secured. On the other hand, if the spacing between the front and rear wheels is set equal to that of the conventional structure, the entire transmission device can be moved significantly toward the side opposite to the engine. Width of space can be obtained.

Differential device 52, 1 located in transmission case 15, 115 on the side of hydraulic transmission device 22, 122
52 and the second chamber 50, 150 for the mechanical transmission 51, 151 located on the opposite side. Connect the intermediate wall to the input shaft 33,1
33 and transmission shafts 53, 153.

In one embodiment of the present invention, the hydraulic transmission device 22, 122 and the transmission case 15, 11 described above are provided.
5 is provided so that the lower half of the hydraulic transmission device and the upper half of the transmission case overlap each other. According to this structure, the pump shaft of the hydraulic pump 24 in the hydraulic transmission device 22, 122 is made to protrude to the side opposite to the engine 11, and can be directly connected to the body of the work vehicle through at least one of the reduction gear or the clutch. It can be used as a PTO shaft to drive other work equipment installed on the opposite side of the engine or work equipment for stationary work.

In another embodiment of the present invention, the left and right axle cases 37, 137 in which the left and right output shafts 35, 135 described above are housed are replaced with the transmission case 1.
The left and right casings 38, 138 are fixedly mounted on the extending ends of the left and right axle cases.

According to this structure, the left and right casings 38 each house a final gear reduction device 40, 140,
Hydraulic transmission device 2 when looking at 138 in the left and right direction of the aircraft.
2 and 122 without considering interference.

If the self-propelled work vehicle is a four-wheel drive type,
Although the driving force for rotationally driving the wheels located on the engine side is taken out from inside the transmission case, in another embodiment of the present invention, the differential gear 52 is connected to the first chamber 49. The engine 11 is installed on one side in the left-right direction of the aircraft.
The wheel driving force extraction shaft 36 for extracting the power for rotationally driving the left and right wheels 12 located on the side is located on the other side in the left-right direction of the fuselage, and the first and second chambers 49,
50 from the first chamber 49 to the engine 1
The wheel driving force output shaft is provided extending in one direction, and the wheel driving force output shaft is connected to the speed change shaft 53 within the second chamber 50.
Concatenate and link to.

According to this structure, the wheel driving force extraction shaft 36 should be rotated at a rotation speed proportional to the rotation speed of the transmission shaft 53.
from inside the second chamber 50 located on the opposite side of the engine to the first chamber 49 while avoiding interference with the differential gear 52.
It can be extended to the inside of the mission case 15 when viewed in the longitudinal direction of the machine body.

Embodiment Vehicle Structure A first embodiment shown in FIGS. 1-7 is a mower according to the present invention, in which a mower M is installed at the lower surface of the fuselage at an intermediate position in the longitudinal direction of the fuselage, as shown in FIGS. 1 and 2. -Regarding an example implemented on a tractor.

As shown in FIGS. 1 and 2, the vehicle frame 10 is provided as a long rectangular frame in the front and rear, and the engine 11 is supported by the vehicle frame 10 and mounted on the front of the vehicle body. A front axle housing 13 for supporting left and right front wheels 12 is supported on the lower front side of the vehicle frame 10 so as to be swingable left and right around a center pin 14. A transmission case 15 supported as described later is provided on the rear lower surface side of the vehicle frame 10, and the left and right rear wheels 16 are supported by the transmission case 15 in a manner also described later.

The passenger seat 17 is installed on the upper rear side of the fuselage. The vehicle is steered by turning the front wheels 12, and the front wheels 12 are positioned in front of the passenger seat 17.
Steering wheel 1 for turning the
8 are arranged.

Arrangement of Transmission Mechanism The tractor shown in FIGS. 1 and 2 rotates the rear wheels 16, and when necessary, the front wheels 12 are also auxiliarily rotationally driven to drive the tractor. rear wheel 16
As will be described later, rear wheel driving force is extracted from inside the transmission case 15 in the left-right direction of the aircraft, and the front wheels 12 are driven by the transmission case 15.
A transmission shaft 21 for transmitting power from inside to the inside of the front axle housing 13 is provided along the longitudinal direction of the fuselage, and the power is transmitted through the transmission shaft 21.

As shown in FIGS. 1-3, a hydraulic transmission device 22 and the transmission case 15 are installed in the rear of the machine so as to overlap one another in the front and back, and the power from the engine 11 is first input to the hydraulic transmission device 22. To this end, a transmission shaft 23 is provided along the longitudinal direction of the aircraft body for transmitting power from the engine 11 to the hydraulic transmission device 22 via the main clutch 19, and this transmission shaft 23 is connected to the hydraulic pump of the hydraulic transmission device 22 at its rear end. It is connected to the pump shaft 25 of No. 24 by a universal joint 26.

A mechanical transmission as shown in FIGS. 3 and 4 is housed inside the mission case 15, and a screw hole 27 is provided in the upper front half of the mission case 15 as shown in FIG. It is formed on a flat mounting surface 28 having a flat mounting surface 28. As clearly shown in FIG. 3, a flange 29 is provided on the back surface of the lower half of the hydraulic transmission device 22, the flange 29 is aligned with the mounting surface 28, and a fixture 30 is screwed into the screw hole 27.
The hydraulic transmission device 22 is connected to the transmission case 15 by
It is fixedly attached to the In other words, the hydraulic transmission device 22
is arranged so that the upper front half of the transmission case 15 overlaps the lower half of the back, and the entire transmission mechanism including the hydraulic transmission device 22 and the transmission case 15 is assembled into a transmission mechanism as described below. It is supported by the machine frame 10 on the side of the case 15.

Power is input to the mechanical transmission in the transmission case 15 from a hydraulic motor 31 of a hydraulic transmission device 22. That is, as shown in FIG. 3, a motor shaft 32 of a hydraulic motor 31 is extended into the transmission case 15 located at the rear, and connected to an input shaft 33 which is arranged concentrically with the motor shaft 32 by a coupling 34. There is.

The mechanical transmission inside the transmission case 15 has an output shaft as shown in FIG.
It includes left and right output shafts 35 extending left and right, and a front wheel drive force extraction shaft 36 extending forward. As shown in FIGS. 4 and 2, left and right axle cases 37 extending left and right are attached to both sides of the transmission case 15.
A casing 38 extending forward from the case 37 is fixedly attached to the end. The left and right output shafts 35 described above are housed inside the left and right axle cases 37, and the axles 39 of the left and right rear wheels 16 are supported by the left and right casings 38, so that the output shafts 35 are mounted inside the left and right axle cases 37. Each output shaft 35 and each axle 39 are connected within each casing 38 by a final gear reduction device 40. The front wheel drive force output shaft 36 is connected to the transmission shaft 21 by a universal joint 41, as shown in FIG.

The entire transmission mechanism including the hydraulic transmission device 22 and the transmission case 15 is mounted on the machine frame 1.
0, the brat 42 shown in the 90 degree rotated position in FIG.
This is done by connecting the brat 42 and the casing 38 with an appropriate number of fixtures 43, as shown in FIGS. 2 and 4.

Hydraulic Transmission Device The hydraulic transmission device 22 connects the hydraulic pump 24, which is of a variable displacement type, and the hydraulic motor 31, which is of a fixed displacement type, to a pair of hydraulic supply and discharge passages (not shown). It has a conventional structure in which it is connected by a wire, and only its external appearance is shown in FIG.

The hydraulic pump 24 and the hydraulic motor 31 are arranged vertically along the front-rear direction, and the pump shaft 2
5 is from the hydraulic transmission device 22 to the transmission case 15
The PTO shaft 44 is configured to extend rearward at the upper side of the PTO shaft 44 for transmitting power to other working machines through the extended portion. An oil passage connecting the hydraulic pump 24 and the hydraulic motor 31 is formed in a thick plate 45 installed on the front surface of the hydraulic transmission device 22, and a thick plate 45 is inserted into the oil passage on the front surface of the plate 45. A line filter 46 is installed.

The displacement of the hydraulic pump 24 is normally controlled by changing the angle of its swash plate, and in FIG. 3, reference numeral 47 is one operating shaft in the swash plate angle changing operation mechanism.

Mechanical Transmission As shown in FIG.
The chamber is divided into two parts: a first chamber 49 located on the front side and a second chamber 50 located on the rear side. The input shaft 33 is supported by an intermediate wall 48 and a back wall of the mission case 15, and is provided so as to straddle the first and second chambers 49, 50. Mitsushion is
Mechanical transmission 51 disposed within second chamber 50
and a differential device 52 arranged below the input shaft 23 in the first chamber 49.

As shown in FIGS. 3 and 4, a transmission shaft 53 is provided in the second chamber 50 below the input shaft 33 and is supported by the intermediate wall 48 and the back wall of the transmission case.
The mechanical transmission 51 includes an input shaft 33 and a transmission shaft 53.
placed in between. Two gears 54 and 55 fixedly installed on the input shaft 33 and two gears 56 and 57 loosely installed on the speed change shaft 53 are meshed with each other to form a two-row speed change gear train. is configured. Both gears 56, 5 are on the transmission shaft 53.
A spline collar 58 is fixedly installed between 7 and 7, and a shifter sleeve 59 is placed on this spline collar 58 so that it can only slide freely.
The shifter sleeve 59 is shifted along the axial direction of the transmission shaft 53, and the pawls on the inner peripheral surface are engaged with the pawls on the boss portions of the gears 56, 57, thereby shifting the gears 56, 57. It is assumed that it is selectively coupled to the speed change shaft 53.

The differential device 52 receives input transmission from the transmission device 51 and outputs it to the output shaft 35 extending in the left-right direction. It is rotatably supported by a mission case 15. The differential device 5
As shown in FIG. 4, a large-diameter input bevel gear 61 is fixed to the second differential case 60 with a fixture 62, and this input bevel gear 61 is extended into the first chamber 49. It meshes with a small bevel gear 63 integrally formed on the front end of the speed change shaft 53. Left and right output shafts 35
is pushed into the differential case 60, and the differential device 52 is inserted into the differential case 60 with pin 6 as usual.
A pair of drive pinions supported through the shaft 4 and a pair of driven pinions fitted on the left and right output shafts 35 are meshed as shown in FIG.

The machine frame 1 is installed between the left and right output shafts 35 and the left and right axles 39.
As shown in FIG.
A small gear 65 integrally formed with a large gear 66 fixed to each axle 39 is meshed with each other.

As shown in FIG. 4 and FIGS. 6 and 7, the differential device 5
2 is installed offset to one side in the left-right direction in the first chamber 49, and is connected to the front wheel drive force extraction shaft 36 described above.
are located on the other side in the left and right direction, and the first and second chambers 49,
50 and is supported by the back wall and front wall of the mission case 15. Inside the second chamber 50 is a transmission shaft 53 and a front wheel drive force extraction shaft 36.
An intermediate shaft 67 located therebetween is supported by the mission case back wall and the intermediate wall 48. A clutch gear 68A is loosely fitted onto the front wheel drive force output shaft 36, and the gear 68A is connected to the gear 68A and the gear 6 fixed to the gear shift shaft 53.
By providing an intermediate gear 70 on the intermediate shaft 67 that meshes with both the second chamber 50 and the second chamber 50, the intermediate gear 70 is interlocked with the second chamber 50. Similarly, in the second chamber 50, a clutch sleeve 68B is provided on the front wheel drive force extraction shaft 36, which is slidable with respect to the extraction shaft 36 but cannot rotate relative to the front wheel drive force extraction shaft 36. A front wheel drive clutch 68 is configured, which is equipped with the clutch gear 68A and the clutch sleeve 68B so that the gear 68A can be selectively coupled to the front wheel drive power take-off shaft 36.

As shown in FIGS. 3 and 4, a friction multi-plate brake 71 is provided at the rear end of the speed change shaft 53. This brake 71 includes a pressure plate 72 for pressing the friction element group, and a pressure plate 72 for pressing the friction element group.
A series of balls 73 are housed in cam grooves between the plate 72 and the transmission case wall to slide the plate 72 in the direction of the friction element group due to the rotational displacement of the pressure plate 7.
2, the transmission case 15 is
The operating shaft 74, which is provided straddling the inside and outside of the
It is equipped with a return spring 75 etc. that pulls back.

As shown in FIGS. 4 and 6, the differential gear 52 includes a friction multi-layer structure in which a plurality of friction elements are slidably supported by the boss portion of the driven pinion on one side and the differential case 60. A plate-type differential lock clutch 76 is attached. The differential clutch 76 is configured to be activated by pushing a pressing ring 77 disposed inside the differential case 60 toward the friction element group using a plurality of pins 78 extending inside and outside the differential case 60. On the boss portion of the differential case 60 is a ball bearing 79 that abuts the pin 78.
A shift fork 8 is slidably provided and engages with the bearing 79 from the opposite side of the pin 78.
0 is set. As shown in FIG. 7, this shift fork 80 is attached to a cam metal fitting 82 that is slidable on an operating shaft 81 that is rotatably disposed horizontally in the transmission case 15. The compression coil spring 85 provided on the operating shaft 81 is energized with its base end received by the spring receiver 84 on the inner wall surface of the mission case 15 with respect to another cam hardware 83 fixedly installed on the operating shaft 81. It is engaged at the bottom. The operating shaft 81 has one end facing outside the transmission case 15 connected to a clutch pedal (not shown), and is rotationally displaced by depression of the pedal.
The opposing end surfaces of the cam hardware 82 and the shift fork 80 are rotated by the rotational displacement of the operating shaft 81 when the pedal is depressed.
is formed on a cam surface that is slidably displaced in the direction in which the pin 78 is pushed in, that is, in the direction in which the differential lock clutch 76 is engaged.

In order to operate the shifter sleeve 59 of the mechanical transmission 51, as shown in FIGS. 6 and 7, it is slid onto a fork shaft 86 fixedly installed inside the transmission case 15 along the longitudinal direction of the aircraft. A freely supported shift fork 87 is engaged with the shifter sleeve 59 at its free end. An operating shaft 88 extending between the inside and outside of the case 15 is rotatably supported on one side wall of the mission case 15, and an arm 89 fixed to the inner end of the operating shaft 88 is mounted on the free end of the operating shaft 88. The pin 89a is also engaged with the shift fork 87. The operating shaft 88 is rotationally displaced by a gear shift lever (not shown), and the shift fork 87 slides and displaces the shifter sleeve 59 by the rotation of the arm 89 due to the rotational displacement of the operating shaft 88. It is displaced along the axial direction of the fork shaft 86.

Note that, as shown in FIG. 7, the front wheel drive force extraction shaft 36 is arranged to cross one output shaft 35 directly above the output shaft 35, whereas both of these shafts 3
In order to reliably avoid interference between the wheels 5 and 36, the front wheel drive force output shaft 36 is provided with a reduced diameter portion 36a shown in FIGS. 4 and 6.

Structure of Other Parts The mower M is supported by the vehicle machine frame 10 via a link mechanism (not shown) so as to be movable up and down, and is raised and lowered by a hydraulic cylinder (not shown). As shown in FIGS. 1 and 2, the rotary drive of the mower M is performed by transmitting power from the engine 11 to a mower drive pulley 90 in a horizontal position located at the front inside the machine frame 10, inside a clutch box 91, and through a bevel gear. The upper and lower 2
This is performed by belt transmission to the input pulley Ma of the mower M via the stage pulleys 93 and 94.

The transmission case 15 also serves as an oil tank for storing oil supplied to the hydraulic transmission device 22 and oil supplied to the mower lifting hydraulic cylinder.As shown in FIG. A filter 95 for cleaning oil pumped out from inside,
It is installed along the left and right direction of the aircraft. In FIG. 5, reference numeral 96 indicates a part of the oil supply pipe for the hydraulic transmission device 22. As shown in FIG.

Operation of the Embodiment The illustrated mower tractor is used for lawn mowing work by driving the rear wheels 16 and, if necessary, by engaging the front wheel drive clutch 68 and additionally driving the front wheels 12 by mowing the mower M while the vehicle is traveling. Ru. The vehicle speed is controlled by changing the volume of the hydraulic pump 24 of the hydraulic transmission device 22 and by changing the gear stage of the mechanical transmission 51 to high or low. This can be done by rotating it in the opposite direction. The brake 71 shown in FIG. 4 etc. is used for braking while the vehicle is running and for braking when parking the vehicle, and the differential clutch 76 is used to release the function of the differential gear 52 in places where driving conditions are poor. used for.

As mentioned above, the PTO shaft 44 extending rearward from the hydraulic transmission device 22 is used when performing stationary work such as pest control work using the power of the engine 11, or when applying fertilizer to the rear of the illustrated tractor using a hit means. It is used to extract the necessary power when connecting other work equipment such as a sowing machine or a seeding machine to perform other work.

In the tractor shown in FIGS. 1 and ₂ , as shown in FIG. motion device 52
The distance between each output shaft 35 and each axle 39, which transmit power in the left-right direction from the casing 38, is connected by the final gear reduction device 40 in each casing ₃₈ extending forward. The rear wheels 16 are closer to the front than in this type of tractor.

Second Embodiment FIGS. 8 and 9 show a mower tractor equipped with a transmission device according to a second embodiment of the present invention, and FIG. 10 shows the main parts of the same tractor.

In the mower tractor shown in FIGS. 8 and 9, the arrangement of the engine 111, hydraulic transmission device 122, and transmission case 115 is just reversed from the tractor shown in FIGS. A transmission device is supported at the rear of the vehicle frame 110 and supported at the front of the vehicle frame 110.
The front wheels 116 are the main driving wheels that are rotationally driven for vehicle travel, and the rear wheels 112, which are rotated by the operation of a steering wheel 118 to direct the aircraft, are auxiliary and rotationally driven.

In Figures 8-10, all parts or parts corresponding to parts or parts of the vehicle according to the previously described embodiments are designated by numbers 100 greater than those previously used. As can be easily understood by comparing these figures with the explanation of the above-mentioned embodiment, the second
The transmission device according to the second embodiment has exactly the same structure as the transmission device according to the first embodiment, except that the transmission device is reversed.

Therefore, the position of the front wheel 116, which is the driving wheel, is determined by the differential gear 152 within the transmission case 115.
and the casing 138 that extends rearward between each output shaft ₁₃₅ and each axle 139 that transmit power from the differential device 152 in the left-right direction.
The front and rear wheels 116, 1 are moved toward the rear wheel 112 by the distance D ₂ obtained by connecting the final gear reducer 140 in the
The spacing between 12 has been made smaller.

Effects of the Invention This invention has an engine installed at one end of the aircraft in the longitudinal direction.
In a self-propelled work vehicle carrying a 1,111, the hydraulic transmission device 22 on the engine side is installed in the transmission device installed at the other end in the longitudinal direction of the machine body.
Mission cases 15 and 11 superimposed on 122
5, the hydraulic motor 31, 131 of the hydraulic transmission device
Mechanical transmission device 51, 151 whose input is transmitted from
is placed on the opposite side of the hydraulic transmission device, and the differential devices 52, 152, which receive input from the transmission, are placed on the side of the hydraulic transmission device, so that power is transmitted from the side farthest to the engine to the side closest to the engine. In addition, power transmission from the left and right output shafts 35, 135 of the differential gear to the left and right drive wheels 16, 116 is further directed toward the engine by the final gear reduction device 40, 140 in the left and right casings 38, 138. Since the left and right drive wheels 16, 116 are arranged approximately at the end of the transmission device on the engine side when viewed in the longitudinal direction of the aircraft, the drive wheels and the wheels 12 on the engine side , 122,
In other words, the distance between the front and rear wheels is made as small as possible to improve the vehicle's turning performance. Also, looking at the front and rear width of the space for mid-mounted work equipment to be secured between the front and rear wheels, if the distance between the front and rear wheels is set equal to that of the conventional case, the drive wheel will be placed in the transmission device and as close to the engine as possible. Considering that the transmission device can be moved further away from the engine by being supported on the side,
The front and back width of the space mentioned above can be greatly expanded.

[Brief explanation of drawings]

FIG. 1 is a partially vertical schematic side view of a mower tractor equipped with a first embodiment of the present invention, FIG. 2 is a schematic plan view of the mower tractor shown in FIG. 1, and FIG.
The figure is a partial longitudinal side view of a part of the mower tractor shown in Figs. 1 and 2, and Fig. 4 is a partially expanded cross-sectional plane view of the transmission case provided in the mower tractor shown in Figs. 1 and 2. 5 is a partially omitted front view of the mission case shown in FIG. 4, and FIG. 6 is a partially omitted front view of the mission case shown in FIG.
A cross-sectional plan development view of the transmission case shown in the figure,
Fig. 7 is a partially omitted vertical sectional front view of the transmission case shown in Fig. 4, Fig. 8 is a partially longitudinal schematic side view of a mower tractor equipped with the second embodiment of the present invention, and Fig. 9. is a schematic plan view of the mower tractor shown in FIG. 8, and FIG. 10 is a schematic plan view of the mower tractor shown in FIGS.
FIG. 2 is a partially longitudinal side view of a portion of the tractor. 10,110...Vehicle machine frame, 11,111...Engine, 12...Front wheel, 112...Rear wheel, 15,115
...Mission case, 16...Rear wheel, 116...Front wheel, 21,121...Transmission shaft, 22,122...Hydraulic transmission device, 23,123...Transmission shaft, 24,124
...Hydraulic pump, 25,125...Pump shaft, 28...
Mounting surface, 31, 131...Hydraulic motor, 32, 13
2...Motor shaft, 33,133...Input shaft, 34,1
34...Coupling, 35,135...Output shaft, 3
6...Front wheel drive force extraction shaft, 37,137...Axle case, 38,138...Casing, 39,13
9...Axle, 40,140...Final gear reduction gear, 4
8,148...Intermediate wall, 49,149...First chamber,
50,150...Second chamber, 51,151...Mechanical transmission, 52,152...Differential gear, 53,15
3... Gear shift shaft, 54, 55, 154, 155... Gear, 56, 57, 156, 157... Gear, 59,
159...Shifter sleeve, 61,161...Input bevel gear, 63,163...Small bevel gear, 65,16
5... Small gear, 66, 166... Large gear, 67... Intermediate shaft, 68... Front wheel drive clutch, 68A... Clutch gear, 68B... Clutch sleeve, 69... Gear, 70... Intermediate gear.

Claims (1)

[Scope of Claims] 1. A self-propelled work vehicle in which an engine is mounted on one end of the body in the longitudinal direction, in which a hydraulic transmission device 22, 122 and a mechanical transmission to which power is input from the engine 11, 111 are installed internally. A transformer is provided with transmission cases 15, 115 overlapping each other in the longitudinal direction of the aircraft with the hydraulic transmission device located on the engine side, and the transmission cases 15, 115 support left and right drive wheels 16, 116. A mission device, wherein the mission case 1
5, 115, a first chamber 4 located on the hydraulic transmission device 22, 122 side by an intermediate wall 48, 148 integrally provided on the inner surface of the transmission case.
9,149 and the second chamber 5 located on the opposite side
0,150, and the hydraulic transmission device 22,
Both chambers 49, 50, 14 mentioned above include input shafts 33, 133 connected to motor shafts 32, 132 of 122.
A transmission shaft 53, 153, which is provided astride the input shaft 9, 150 and located below the input shaft, is provided in the second chamber 50, 150, and the second chamber 5
Both axes 33, 53, 13 within 0,150
A mechanical transmission 51, 151 is disposed between the transmission shafts 53, 153, and a differential device 5 receives input transmission from the transmission shafts 53, 153 and transmits output in the left-right direction of the aircraft.
2,152 are provided in the first chamber 49,149 below the input shaft 33,133, and the left and right output shafts 35,135 of the differential gear 52,152 and the left and right drive wheels 16,116 described above axle 39,1
Left and right casings 38, 1 are fixedly supported by the transmission cases 15, 115 and protrude in the direction of the hydraulic transmission devices 22, 122 between the left and right casings 38, 1.
The transmission system of the self-propelled work vehicle is connected by a final gear reduction gear 40, 140 in 38. 2. The transmission device according to claim 1, which includes the above-mentioned hydraulic transmission device 2.
2,122 and a transmission case 15,115, the lower half of the hydraulic transmission device and the upper half of the transmission case are provided so as to overlap each other, a transmission device for a self-propelled working vehicle. 3. In the transmission device according to claim 1 or 2, the left and right axle cases 37, 137 in which the left and right output shafts 35, 135 described above are housed are combined with the transmission case 1.
A transmission for a self-propelled work vehicle, which is provided extending left and right from the left and right side surfaces of 5,115, and has the left and right casings 38,138 fixedly attached to the extending ends of the left and right axle cases. sion device. 4. The transmission device according to any one of claims 1 to 3, wherein the differential device 52 is disposed within the first chamber 49 on one side in the left-right direction of the fuselage. A wheel driving force extraction shaft 36 is installed on one side and extracts power for rotationally driving the left and right wheels 12 located on the engine 11 side.
This wheel driving force extraction shaft is provided on the other side in the left-right direction of the machine body, straddles the first and second chambers 49 and 50, and extends from the first chamber 49 toward the engine 11. A transmission device for a self-propelled work vehicle, which is operatively connected to the speed change shaft 53 within the second chamber 50.