JP2002337559A - Power transmitting device for work vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a problem that a large number of part items are required to increase a cost with miniaturization incapable of a vehicle due to a constitution providing a transmission gear transmitting power to a drive shaft in an axle case and a brake device braking the drive shaft respectively in the right/ left of the shaft extended from a bevel gear, in the constitution mounting the axle case in right/left both side parts of a transmission case in a tractor or the like. SOLUTION: A differential gear 60, 61, 62 generating a right/left rotational difference in a crawler is provided in the right/left axle case 4, and a right/left drive shaft 5, 5 internally mounted in the right/left axle case is constituted in a single axial state. A pinion gear 6 transmitting rotational power of an engine and a bevel gear 7 meshed with this pinion gear 6 are arranged in a right/left almost central position in the transmission case 2, and a transmission gear 9 transmitting power to the drive shaft 5 is provided in one side part of a support shaft 8 supporting the bevel gear 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to agriculture, architecture,
The present invention relates to a power transmission device for a work vehicle for transportation.

[0002]

2. Description of the Related Art Conventionally, agricultural tractors have been disclosed in
As shown in JP-A-91655, a transmission case is connected from the engine in the front-rear direction of the vehicle body, and an axle case supporting a wheel-type traveling device is connected to left and right sides of the transmission case.

[0003] A pinion gear and a bevel gear meshing with the pinion gear are arranged at substantially the left and right central portions of the rear of the transmission case, and the rotation of the bevel gear is transmitted to the drive shafts in the left and right axle cases via a differential mechanism. ing.

[0004]

However, in the above-mentioned conventional construction, power is supplied to the drive shaft in the axle case by the left and right sides of the support shaft for supporting the bevel gear, that is, the shaft extending from the differential mechanism. Therefore, there is a problem that the number of parts in the production is large and the cost is high because the transmission gear and the brake device (brake disk) are provided. Further, since a space for providing a transmission gear and a brake device is required on each side of the transmission case, the width of the transmission case is increased, which hinders downsizing of the vehicle.

[0005]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention provides a power transmission device for a working vehicle as follows. That is, in the invention of claim 1, a transmission case (2) is connected from the engine (1) in the front-rear direction of the vehicle body, and an axle case (2) supporting the traveling device (3) is provided on both left and right sides of the transmission case (2). In the working vehicle to which the axle case (4) is connected,
Left and right drive shafts (5) provided in the left and right axle cases (4) are provided with differential devices (60, 61, 62) for producing a rotation difference in the rotating body (16) of the left and right traveling device (3).
While the transmission case (2)
A pinion gear (6) and a pinion gear (6) for transmitting the rotational power of the engine (1) to a substantially central position on the left and right sides of the inside
And a transmission gear (9) for transmitting power to the drive shaft (5) is provided on one side of a support shaft (8) that supports the bevel gear (7). A power transmission device for a working vehicle, which is a feature of the present invention.

According to a second aspect of the present invention, the engine (1)
To the transmission case (2) in the front and rear direction of the vehicle,
In a work vehicle in which an axle case (4) supporting a traveling device (3) is connected to both left and right sides of the transmission case (2), the engine (1) is located at a substantially central position in the transmission case (2). And a bevel gear (7) that meshes with the pinion gear (6) for transmitting the rotational power of the support shaft (8). The both sides of the support shaft (8) are located at symmetrical positions in the transmission case (2). A supporting inner wall (12, 12) is formed, and a brake disc (10a) pressed between the inner wall (12) and the axle case (4) is pressed against the inner wall (12).
And a pressure plate (10b) for pressing the brake disc (10a), and a brake ball (13) contacting the pressure plate (10b) and the end surface of the axle case (4). 10) The power transmission device for a work vehicle, wherein the power transmission device is configured.

Further, in the invention of claim 3, a transmission case (2) is connected from the engine (1) in the longitudinal direction of the vehicle body, and a traveling device (3) is supported on both left and right sides of the transmission case (2). In a working vehicle to which an axle case (4) is connected, a pinion gear (6) for transmitting rotational power of the engine (1) to a substantially central position on the left and right in the transmission case (2) and a bevel gear ( 7), an inner wall (12, 12) for supporting both sides of the support shaft (8) is formed at symmetrical positions in the transmission case (2), and an inner wall (12) on one side thereof is formed. A transmission gear (9) for transmitting power to a drive shaft (5) in the axle case (4) is provided between the axle case (4) and an end of the support shaft (8). And a power transmission device for a working vehicle, characterized in that supported in Rukesu (4) opening hole formed in the side (11).

[0008]

In the power transmission device for a working vehicle constructed as described above, when the pinion gear (6) is driven by the driving of the engine (1), this rotational power is transmitted to the bevel gear (7) and the support shaft ( 8) is transmitted.

[0009]

According to the first aspect of the present invention, in the left and right axle cases (4), the differential device (60,
61, 62), and the left and right drive shafts (5) housed in the left and right axle cases (4) are configured to be uniaxial,
A pinion gear (6) for transmitting the rotational power of the engine (1) and a bevel gear (7) meshing with the pinion gear (6) are arranged at substantially right and left central positions in the transmission case (2). Since a transmission gear (9) for transmitting power to the drive shaft (5) is provided on one side of the supporting shaft (8) for supporting, the transmission gear and the brake device are respectively provided on the left and right as in the conventional configuration. Need not be provided, and the number of components involved can be reduced, thereby reducing production costs.

According to the second aspect of the present invention, between the inner wall (12) and the axle case (4), a brake disk (10a) pressed by the inner wall (12) and the brake disk (10a) are pressed. Pressure plate (10b) to be operated and this pressure plate (10b)
And a disc-type brake device (1) having a brake ball (13) abutting on an end surface of the axle case (4).
0), the contact portion of the brake disc (10a) is also used as the support portion of the support shaft (8), and a separate member for contacting the brake ball (13) is not required. ) Can be narrowed to reduce the size of the work vehicle.

Still further, in the invention according to claim 3, the inner wall (1)
A transmission gear (9) for transmitting power to a drive shaft (5) in the axle case (4) is provided between the axle case (4) and the axle case (4). Since the support shaft is supported by the opening hole (11) formed on the axle case (4) side, for example, the end of the support shaft (8) is compared with a configuration in which a wall pressure portion for separately supporting the end of the support case (2) is formed. Thus, the left and right width of the mission case (2) is reduced by the space of the thick portion, and the work vehicle can be downsized.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a tractor provided with a crawler type traveling device as a working vehicle will be described below. As shown in FIG. 2, the tractor T has an engine mounting frame 15 disposed at the front of the vehicle body, the engine 1 serving as a prime mover mounted on the frame 15, and an engine rotation output shaft 14 protruding from the rear of the engine 1.
The rotation of the coaxial 14 is transmitted to the transmission in the transmission case 2 (front transmission case 2a, mid transmission case 2b, rear transmission case 2c) arranged in the vehicle longitudinal direction. The rotational power appropriately reduced by the transmission is transmitted to the drive shaft 5 in the left and right rear axle cases 4 and the crawler-type traveling device 3 via pinion gears 6 and bevel gears 7 described later.

Above the transmission case 2, the floor 15 is supported. On the floor 15, a steering handle 17 for steering the vehicle body with a rotation difference between crawlers 16 serving as left and right rotating bodies, a cockpit 18 , The position lever 19 for adjusting the height of the work implement, the speed change lever 2 for traveling
1. The brake pedal 29 and the like are provided.
Further, fenders 22 that cover the upper part of the crawler 16 are provided on both left and right sides of the floor 15.

The fender 22 will be described.
A hand catcher 23 for getting on and off is directly attached to the left fender 22 on the right side, and
As shown in FIG. 3, the hand catcher 23 is configured to be mounted with a switch box 24 having various control switches and indicators, for example, a rolling control setting device 20a and an indicator lamp 20b added depending on the model. Thus, when the control is added as described above, the switch or the display related thereto can eliminate the mounting member on the vehicle body or the processing in the production, and can reduce the improvement cost, and furthermore, these settings can be made. Since the vessels and indicators are protected by the hand catcher 23, the catch of clothes and plants can be reduced as much as possible.

On the upper surface of the rear transmission case 2C, a hydraulic cylinder 25 for lifting and lowering the working machine is provided, and a lift arm 26 connected to a piston of the cylinder 25 is vertically rotated via a link mechanism 27 to perform work. Machine 28
Up and down.

In the model having the rolling control in the figure, a hydraulic cylinder 83 for rolling a working machine is attached to a part of the link mechanism 27. Next, a power transmission structure of the tractor T will be described with reference to FIGS. The rotational power input from the engine output shaft 14 into the front transmission case 2a is first transmitted to the lower part of the case by the reduction gear 25, transmitted to the rear main clutch 30, and provided at the front of the case 2a. The power is transmitted to the hydraulic pump 31.

The power that has been turned on and off by the main clutch 30 is appropriately decelerated by a main transmission 32 and an auxiliary transmission 33 in the mid-transmission case 2b, and an auxiliary transmission output shaft 34 having a pinion gear 6 to be described later. Is transmitted to
The main changing device 32 is a so-called key shift type transmission, and a main shifting device 32 is provided between the main shifting drive shaft 35 and the main shifting driven shaft 36.
A gear set having a third speed and a single reverse speed is provided, and one of the gear sets is operated by operating a slide key 37 provided in the main speed driven shaft 36 back and forth. It is configured to transmit power via the power supply.

The auxiliary transmission 33 is a constant mesh gear type transmission, and an auxiliary transmission drive shaft 38 is rotatably provided on an extension of the main transmission drive shaft 35.
A "low speed" gear 39 is provided on the coaxial 38, while a sub-speed driven shaft 34 having the pinion gear 6 is provided on the extension of the main speed driven shaft 36, and the "high speed" direct-coupled gear 44 is provided on the coaxial 34, A slide gear having a “low speed” driven gear 40 meshing with the “low speed” drive gear 39 is provided. Reference numerals 41 and 42 in the drawings denote transmission gear sets that transmit power to the front wheels when the tractor T is configured as a four-wheel drive type.

At the front lower part of the front transmission case 2a, a filter 45 is provided extending from the front surface of the case 2a to the rear of the main clutch 30, and the hydraulic cylinder 25 for lifting and lowering the work machine and the reverse rotation clutches 60, 60 to be described later. It is configured to filter the pressure oil sent to the tank. Accordingly, clean oil can be sucked in without being affected as much as possible by bubbles generated by rotation of the clutch 30 and the like. In addition, when the tractor T is configured as a four-wheel drive type, the mounting hole 46 of the filter 45 uses an opening hole that penetrates and supports the front wheel drive shaft.

Next, a power transmission configuration of the crawler type traveling device 3 serving as a traveling device of the tractor T will be described with reference to FIG. The rear portion of the rear transmission case 2c is separated from the left and right side surfaces by a predetermined distance from the inner walls 12,12.
And a space S is formed between the inner surface of the axle case 4 to be described later, and the pinion gear 6 at the rear end of the sub-variable driven shaft 34 is disposed at a substantially right and left center position in the transmission case 2c. It has a configuration. A bevel gear 7 meshing with the pinion gear 6 is provided at a substantially central position of a support shaft 8 supported by the left and right inner walls 12, 12, and a side portion of the support shaft 8 (a portion located in a right space S in the drawing). ) Is projected outwardly from the inner wall 12 so that the brake disc 10a and the pressure plate 10b
And the like.

The inner wall 12 may be formed of a member different from the transmission case, for example, a metal member, and may be mounted in the case. In addition, the line XX in the figure indicates the left and right center line of the transmission case 2c. Further, the brake device 10 rotates the brake operation shaft 51 penetrating into the space S from outside the case 10 c, thereby causing a contact between the cam groove of the pressure plate 10 b and the inner surface of the axle case 4. The brake ball 13 in contact with and moves the pressure plate 10b to the inside of the vehicle body to press the brake disc 10a, and the rotation of the support shaft 8
That is, the rotation of the crawler 56 of the crawler traveling device 3 is braked.

On the other hand, the other end of the support shaft 8 (the portion located in the left space S in the figure) also protrudes outward from the inner wall, and this tip is opened to the connection surface of the axle case 4. The transmission gear 9 for transmitting power to the first drive shaft 5 of the axle case 4 is provided in the space S surrounded by the inner wall 12 while bearing in the hole 11 via a bearing 53. The first drive shaft 5 in the left and right axle cases 4, 4 is coupled to the coupling 5 in the transmission case 2c.
The transmission gear 55 is connected to the same shaft center by 4 and is always engaged with the transmission gear 9 below the transmission gear 9.

In the configuration of the rear portion of the rear transmission case 2c of the tractor T configured as described above, it is not necessary to provide a transmission gear and a brake device on the left and right, respectively, unlike the conventional configuration, and the number of parts required for these components can be reduced. Production costs can be reduced. The inner wall 12 on the right side in FIG.
Between the axle case 4 and the brake disk 10a pressed against the inner wall 12;
0a, a pressure plate 10b for pressing operation, the pressure plate 10b and the axle case 4
The disk type brake device 10 having the brake ball 13 abutting on the end face of the brake disk 10 is configured, so that the abutting portion of the brake disk 10a is also used as the supporting portion of the support shaft 8, and a separate member for abutting the brake ball 13 is provided. Since it becomes unnecessary, the left and right width of the transmission case 2 can be reduced, and the tractor T can be downsized.

The inner wall 12 and the axle case 4 on the left side in FIG.
And a transmission gear 9 for transmitting power to the first drive shaft 5 in the axle case 4, and an end of the support shaft 8 is supported by an opening hole 11 formed in the axle case 4. Therefore, for example, as compared with a configuration in which the end portion of the support shaft 8 is separately formed to support the end portion of the support shaft 8 on the side of the transmission case 2, the rear transmission case 2 is limited by the space of the thick portion.
By narrowing the left and right width of c, the tractor T can be miniaturized, and in particular, the tread can be shortened.

Next, the continuously variable transmission located on the lower power side of the first drive shaft 5 will be described. The left and right axle cases 4 are respectively provided with a reverse clutch 60 (inside the vehicle body) and a forward rotation clutch 61 (outside the vehicle body) in the form of a wet multi-plate on the first drive shaft 50. A so-called two-stage planetary gear mechanism 62 having a counter gear is provided outside the clutch 61. The forward rotation clutch 61 is always pressed by an internal spring 63. In this state, the drive side sun gear 64 integrated with the drive side disk of the forward rotation clutch 61, the planetary gears meshing with the drive side sun gear 64, and the The drive-side disk and the integral carrier 65 are configured to rotate integrally around the drive-side sun gear 64.

Thus, the rotation of the driving-side sun gear 64, that is, the rotation of the bevel gear 6, is transmitted to the driven-side sun gear 66 on a one-to-one basis.
The transmission is performed at the rotation ratio. When pressure oil is sent to the piston portion 67 of the reverse rotation clutch 60,
On the contrary, the compression of the disc of the forward rotation clutch 61 is gradually released, and a rotation difference is generated between the drive side drive side disc and the driven side disc, and the rotation is transmitted to the driven side sun gear 66 accordingly. Is reduced. When the pressure oil is further fed to the piston portion 67 and the movement amount of the piston is increased toward the inside of the vehicle body, the compression of the disc of the forward rotation clutch 61 is completely released, and the transmission rotation of the driven sun gear 66 is reduced. This time, the drive side disk and the driven side disk of the reverse rotation clutch 61 fixed to the axle case 4 side are gradually press-fitted,
The rotation of the carrier 65 is transmitted to the driven-side sun gear 66 via the two-stage planetary gear mechanism 62 by reverse rotation.

Thus, the rotation of the bevel gear 7, that is, the rotation of the first drive shaft 5 is transmitted to the driven-side sun gear 66 at a gradually reduced speed, and the speed is gradually increased in the reverse direction through a non-rotation state. Has become. In addition, the rotation ratio at the time of the reverse rotation is set to be approximately 30% of the gear ratio at the time of the forward rotation, and the continuously variable transmission having the clutches 60 and 61 and the two-stage planetary gear mechanism 62 includes: It is used as a differential device that operates independently of the left and right crawlers depending on the turning angle of the steering handle 17 of the tractor T to cause a difference between the left and right crawlers.

The driven sun gear 66 is integrally assembled with a second drive shaft 70 for supporting the driven sun gear 66 and a lid 68 for shielding the outside opening of the axle case 4. The lid 68 has a pack shape, and a planetary gear type reduction mechanism 72 for transmitting the rotation of the second drive shaft 70 to the output shaft, that is, the sprocket shaft 71, by reducing the rotation of the second drive shaft 70 therein. Annular projection 6 that supports the sprocket and protects the internal sealing member
9 is formed.

The axle case 4 of the tractor T
When the cover 68 is assembled, the speed reduction mechanism 72
Is covered with the axle case 4. In the drawing, reference numeral 73 denotes a sprocket for driving the crawler 7, and reference numeral 64 denotes a rotation detecting gear. The rotation is detected.

Next, the hydraulic circuit of the tractor T will be described with reference to FIG. The hydraulic pump 31 is configured to suck up oil in the transmission case 2 by driving the engine 1 and branch pressure oil into the working machine operating hydraulic circuit L1 and the traveling hydraulic circuit L2.

The work machine operating system hydraulic circuit L1 is connected to a relief valve 80 and a flow dividing valve 81 from the upstream side of the circuit. The working machine lifting hydraulic cylinder 25 is connected via a valve 84.

The traveling system hydraulic circuit L2 includes a pressure reducing valve 8
5, the pressure is held, and the circuit is connected from the upstream side of the circuit via the proportional pressure control valve 86 and the switching control valve 87 to the right or left reverse rotation clutch 61 so as to send pressure oil. Thus, by adjusting the hydraulic pressure to the reverse rotation clutch 61 selected by the switching control valve 87 by the proportional pressure control valve 86, the rotation of the crawler 16 on one side is changed from the normal rotation to the reverse rotation through the non-rotation state. Switching speed can be gradually increased.

[Brief description of the drawings]

FIG. 1 is a sectional view of an axle case and a rear transmission case.

FIG. 2 is an overall side view of the tractor.

FIG. 3 is a perspective view of a hand catcher unit.

FIG. 4 is a diagram of a power transmission mechanism in a transmission case.

FIG. 5 is a power transmission diagram of a tractor.

FIG. 6 is a hydraulic circuit diagram of the tractor.

[Description of Signs] 1 Engine 2 Transmission case 3 Crawler traveling device 4 Axle case 5 First drive shaft 6 Pinion gear 7 Bevel gear 8 Support shaft 9 Transmission gear 10 Disc type brake device 11 Bearing support hole 12 Inner wall T Tractor S Space

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B62D 11/10 B62D 11/10 (72) Inventor Tatsuya 1 No. 1 Yakura, Tobe-cho, Iyo-gun, Ehime Prefecture Iseki Agricultural Machinery Co., Ltd. In-house Engineering Dept. Reference) 2B043 AA03 AB02 BA02 BA05 BB03 DB04 DB06 3D039 AA03 AB22 AC21 AC24 AC26 AD11 3D052 AA18 DD03 EE01 FF01 GG03 JJ08 JJ10 JJ14 JJ20

Claims (3)

[Claims] 1. A transmission case (2) is connected from an engine (1) in the longitudinal direction of a vehicle body, and an axle case (4) supporting a traveling device (3) is connected to both left and right sides of the transmission case (2). A differential device (60, 61, 62) for generating a rotation difference between a rotating body (16) of the left and right traveling device (3) in the left and right axle cases (4); The left and right drive shafts (5) provided in the axle case (4) are configured to be uniaxial, and a pinion gear (6) for transmitting the rotational power of the engine (1) to a substantially central position on the left and right in the transmission case (2). ) And a bevel gear (7) meshing with the pinion gear (6), and a transmission gear (5) for transmitting power to the drive shaft (5) on one side of a support shaft (8) supporting the bevel gear (7). 9)
A power transmission device for a working vehicle, comprising: 2. A transmission case (2) is connected from the engine (1) in the front-rear direction of the vehicle body, and an axle case (4) supporting a traveling device (3) is connected to left and right sides of the transmission case (2). And a pinion gear (6) for transmitting the rotational power of the engine (1) and a bevel gear (7) meshing with the pinion gear (6) are arranged at substantially right and left central positions in the transmission case (2). Inner walls (12, 12) for supporting both sides of the support shaft (8) are formed at symmetric positions in the transmission case (2), and the inner wall (12) on one side and the axle case (4) are formed. A brake disk (10a) pressed against the inner wall (12), a pressure plate (10b) for pressing the brake disk (10a), A power transmission device for a working vehicle, comprising: a disk type brake device (10) having a pressure plate (10b) and a brake ball (13) abutting on an end surface of the axle case (4). 3. A transmission case (2) is connected from the engine (1) in the front-rear direction of the vehicle body, and an axle case (4) supporting a traveling device (3) is connected to left and right sides of the transmission case (2). And a pinion gear (6) for transmitting the rotational power of the engine (1) and a bevel gear (7) meshing with the pinion gear (6) are arranged at substantially right and left central positions in the transmission case (2). Inner walls (12, 12) for supporting both sides of the support shaft (8) are formed at symmetric positions in the transmission case (2), and the inner wall (12) on one side and the axle case (4) are formed. A transmission gear (9) for transmitting power to a drive shaft (5) in the axle case (4), and an end of the support shaft (8) is formed on the axle case (4) side. A power transmission device for a working vehicle, wherein the power transmission device is supported by an opening hole (11).