KR20170038266A

KR20170038266A - A transmisstion for a working vehicle

Info

Publication number: KR20170038266A
Application number: KR1020150137382A
Authority: KR
Inventors: 김종순
Original assignee: 김종순
Priority date: 2015-09-30
Filing date: 2015-09-30
Publication date: 2017-04-07

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a transmission for a work vehicle in which power from an engine is inputted through a continuously variable transmission to perform forward and rearward and high and low speed shifts. The transmission of the present invention receives power from a continuously variable transmission, And a first forward gear set including a plurality of power transmission gears that are integrally rotated by being coupled with each other in diameters different from each other, and an input shaft disposed in parallel with the input shaft, And an idle shaft to which a second forward gear set including a plurality of power transmission gears having different diameters from each other is freely rotatably disposed.

Description

{TRANSMISSION FOR A WORKING VEHICLE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission used in a working vehicle, and more particularly to a transmission mounted on a working vehicle that travels on roads or rough roads, such as a tiller or a tractor, and performs various works using power from the engine.

Work vehicles, including tractors and tillage machines, are used not only on roads but also on non-roads or roads, such as orchards, mountainous areas, paddy fields, etc., as well as various work devices to carry out various tasks such as cultivation, transfer and spraying.

Such a working vehicle travels at a high speed when traveling on a pavement, but operates at a low speed when traveling on an unpacked road or a work place, not on a road. Particularly when traveling on a rough road or a ramp, Move at low speed.

Accordingly, the working vehicle must be shifted so as to exhibit a wide shift range and a high driving torque unlike other vehicles predominantly running on pavement roads, and the function of driving the work device by distributing the power of the engine must also be provided.

As an example of a power transmitting device for such a working vehicle, there is a transmission of the invention disclosed in Korean Patent Publication No. 10-0988155 (Document 1).

The transmission of the type described in the document 1 is transmitted to the differential device of the rear axle through the forward-reverse transmission mechanism, the high-low speed transmission mechanism and the multi-speed transmission mechanism, in which the power from the engine is used in a gear- And is distributed to a transmission device using a separate gear type transmission mechanism as a power take-off mechanism (PTO) for driving.

In this type of transmission, a plurality of separate gear-type transmission mechanisms are provided, so that a wide range of shifting required for a working vehicle is not sufficiently achieved despite the large transmission size and excessive weight.

In order to solve the problem of the power transmission device using only the gear type transmission mechanism, a power transmission device having a hydrostatic transmission (HST) has been developed and widely used. As a typical example thereof, Korean Patent Publication No. 10-0534506 (Document 2).

This 'HST' is equipped with a variable displacement hydraulic pump driven by a power from the engine and a hydraulic motor driven by the hydraulic pressure generated by the hydraulic pump, so that the continuously variable transmission of a wide range of torque and speed .

The transmission disclosed in Document 2 is configured to transmit the output shifted by the HST to the differential devices that distribute the power to the front axle and the rear axle by shifting the gear type auxiliary transmission at high and low speed and forward and backward, respectively.

Although not described in Document 2, referring to the configuration of the transmission shown in Fig. 5 of Document 2, the output shifted from the HST is transmitted to the front side of the vehicle through a transmission mechanism for forward / reverse shifting and a gear mechanism for high- Which is transmitted to a differential device of an axle and a rear axle. Since the transmission mechanism is constituted by respective gear transmission mechanisms installed and operated on a plurality of shafts and requires a separate transmission shaft for power transmission, And power transmission efficiency is very low.

On the other hand, the power transmission device of the work vehicle must have a power take-off device for transmitting power to the work device provided in the work vehicle. In some cases, the power from the power take- The transmission does not have such a configuration.

An example in which a hydrostatic type continuously variable transmission is used to shift the driving power and constitute a power take-off device for a working device, and a power take-off device for a working device can be used for driving, is disclosed in Korean Patent Laid- 2012-0079686 (Document 3).

In the transmission of Document 3, the mechanical output of the running constant-pressure hydraulic type continuously variable transmission and the mechanical output of the power take-off device (PTO) are combined by the planetary gear mechanism. The mechanical output of the running constant- And the synthesized output is outputted from the ring gear to be input to the transmission mechanism for forward and reverse shifting.

According to the configuration of the transmission apparatus of the document 3, since the power transmission system of the working vehicle requires a complicated additional mechanism such as a planetary gear set for powering the power for driving the PTO as the driving power, The structure of the power transmission system is very complicated, the weight is excessively high, the manufacturing cost is extremely high, and a reduction in the power transmission efficiency due to the use of the additional gear set can not be avoided.

In the conventional power transmission device for a work vehicle such as the documents 2 and 3, a forward-reverse transmission mechanism and a high-low-speed transmission mechanism are separately provided in addition to a continuously variable transmission for shifting in a wide range such as HST, There is a problem that the structure of the power transmission device is complicated, the weight is excessive, the manufacturing cost is increased, and the power transmission efficiency is lowered.

Document 1: Korean Patent Publication No. 10-0988155 Document 2: Korean Patent Publication No. 10-0534506 Document 2: Korean Patent Publication No. 10-2012-0079686

SUMMARY OF THE INVENTION It is an object of the present invention to provide a transmission having a very simple and compact configuration and capable of shifting the output of the continuously variable transmission forward and backward and at a high and low speed in consideration of the problems of the conventional art described above.

Further, the present invention is intended to provide a transmission having a configuration in which the power for the power take-off device can be diverted as driving power without a complicated separate synthesizing mechanism such as a planetary gear mechanism disclosed in the transmission of Document 3.

Further, the present invention aims to provide a transmission having a configuration in which the output of the transmission can be distributed to the drive shaft of the working vehicle by a very efficient and simple configuration.

According to the present invention, there is provided a transmission for a work vehicle in which power from an engine is input via a continuously variable transmission to perform forward and rearward and high-low-speed shifting, wherein the transmission according to the present invention includes: An input shaft to which a first forward power transmission element and a first forward gear set including a plurality of power transmission gears, which are different in diameter from each other and integrally rotated, are freely rotatably disposed; And a second forward gearing including a plurality of power transmission gears having different diameters from each other and coupled to an output gear for outputting power to a drive shaft of the working vehicle and a second forward power transmission element, Wherein the set includes an idle shaft rotatably disposed,

Wherein the first reverse power transmission element and the second reverse transmission power transmission element are engaged with each other so as to transmit power from the input shaft to the idle shaft while rotating the input shaft and the idle shaft in the same direction, Wherein the plurality of power transmission gears of the first forward gear set engage with any one of the plurality of power transmission gears of the second forward gear set and the input shaft is connected to the first forward power transmission element and the first forward transmission gear, Wherein the first forward gear set is capable of transmitting power from the input shaft to the first forward power transmission element or the first forward gear set by selectively engaging the gear set with the input shaft, One of the power transmission gears is selectively engaged with the idle shaft, So that power from the input shaft can be transmitted to the idle shaft.

The power transmission from the engine is transmitted to the input shaft via the continuously variable transmission and is transmitted to the input shaft even when the input shaft rotates, and the first forward power transmission element and the first forward gear set The first forward power transmission element and the first forward gear set do not rotate so that the power is transmitted from the input shaft to the idle shaft It is not delivered.

When the working vehicle is advanced, the first forward gear set is engaged and rotated with the input shaft, so that the power transmission gears of the second forward gear set of the idle shaft engaged with the power transmission gears of the first forward gear set are rotated do. When any one of the power transmission gears of the second forward gear set is engaged with the idle shaft, power is transmitted to the idle shaft according to the gear ratio of the power transmission gear meshed with each other, and the idle shaft rotates in the direction opposite to the input shaft. The rotation of the idle shaft is transmitted to the drive shaft through the output gear.

On the other hand, in a state where the first forward gear set is engaged with the input shaft and the power transmission gears of the second forward gear set of the idle shaft are not engaged with the idle shaft, the transmission is in the neutral state and the idle shaft does not rotate.

The first reverse power transmission element rotates by engaging with the input shaft and the second reverse power transmission element meshed with the first forward rotation power transmission element rotates so that the idle shaft rotates in the same direction as the input shaft, The rotation of the rotating idle shaft is transmitted to the drive shaft through the output gear.

As described above, in the transmission according to the present invention, in the simple configuration and operation in which the elements for transmitting power, which are disposed on two axes provided parallel to each other, namely, the input shaft and the idle shaft, are engaged with or disengaged from the shaft for forward and reverse or high- The forward and backward shift and the high and low speed shift are performed.

In particular, the elements for power transmission disposed on the input shaft and the idle shaft, i.e., the forward gear set and the reverse power transmission elements are not engaged with most of the shafts except for transmitting power through the corresponding elements, The power loss due to rotation of the elements not involved in power transmission in the transmission operation is minimized.

On the other hand, in the working vehicle, it is advantageous that the power from the power take-off device for driving the working device in addition to the driving power can be used for traveling, but the power from the power take-off device is input to the power transmission system for traveling A complicated gear mechanism as disclosed in Document 3 is required.

In the transmission according to the present invention, the first reverse power transmission element and the first forward gear set are installed in the input shaft in a freely rotatable state and selectively engage only the input shaft. Therefore, in a state in which they are not engaged with the input shaft, The idle shaft can be maintained in a non-rotating state. Also, even when the first forward gear set is engaged with the input shaft, in a state where the power transmission gears of the second forward gear set of the idle shaft are not engaged with the idle shaft, the idle shaft can not be rotated despite the rotation of the input shaft have.

Therefore, in the transmission of the present invention, the idle shaft is directly driven by the power from the power take-off device, and if necessary, the idle shaft is driven by the power from the power take- Can be operated.

As described above, according to the structure and operation of the transmission according to the present invention, the structure of the transmission for driving without using a separate complex power combining mechanism such as a planetary gear set for using the power from the power take- So that the entire structure of the power transmission apparatus is very simple and efficient.

In one additional aspect of the invention, the first and second reverse power transmission elements are chain sprockets engaged with one chain and configured to transmit power from the input shaft to the idle shaft via the chain .

In this way, the power transmission for backward movement between the input shaft and the idle shaft is constituted by the chain mechanism, so that the input shaft and the idle shaft as the output shaft are driven in the same direction in the reverse shift, It is possible to transmit the power for rotating in the same direction between the input shaft and the idle shaft by a single power transmission of a chain mechanism.

The differential mechanism may further include a differential mechanism disposed in parallel with the input shaft and the idle shaft and transmitting power to the drive shaft of the working vehicle, wherein the differential mechanism is engaged with the output gear of the idle shaft, An input gear for transmitting the power from the shaft to the differential cage is provided and the input gear is coaxially arranged and coupled to the differential cage.

According to such a configuration, it is possible to provide a differential mechanism for distributing the power to the drive shaft such that the differential cage of the differential mechanism receives the power directly from the idle shaft, which is the output shaft of the transmission, by engaging the gear, without providing a power transmission shaft for transmitting the power from the transmission The structure for transmitting the power from the transmission to the differential mechanism is very simple and the power transmission can be efficiently performed. In particular, the differential mechanism for distributing the power to the drive shaft of the working vehicle can be configured as a single device with the transmission So that the power transmission system of the vehicle can be configured to enable very compact and efficient power transmission.

1 is a schematic view showing a configuration and arrangement of a power transmission apparatus of a working vehicle including a transmission according to an embodiment of the present invention,
2 is a longitudinal sectional view showing a configuration of a transmission according to an embodiment of the present invention,
FIG. 3 is a longitudinal sectional view showing a state in which a second hydraulic motor attached to the transmission is attached in FIG. 2,
FIG. 4 is a cross-sectional view schematically showing a configuration of a differential apparatus built in a transmission according to an embodiment of the present invention,
5 is a cross-sectional view of the differential device along line AA of FIG. 2;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a structure and operation of a transmission according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings, and one embodiment of a power transmission apparatus for a work vehicle on which the transmission is installed.

First, with reference to Fig. 1, a schematic configuration of a power transmission apparatus provided with a transmission according to an embodiment of the present invention will be described. In this figure, the detailed configuration of each element is not shown, and only the schematic arrangement is shown.

The input side pulleys 11 and 21 of the first and second continuously variable transmissions 10 and 20 are coupled to the output shaft 2 of the engine 1 as a power distribution shaft so as to be driven by the engine 1. [

The continuously variable transmissions 10 and 20 are provided with power transmission belts 13 and 23 between two pulleys 11, 12, 21 and 22 whose diameters are variable, The shift is performed between the output side. However, the first continuously variable transmission of the present embodiment is not limited to such a belt type continuously variable transmission and may be, for example, a hydrostatic transmission (HST) composed of a hydraulic pump and a hydraulic motor driven by the hydraulic pump.

The transmission 30 is coupled to the output side pulley 12 of the first continuously variable transmission 10 so that the power of the engine that is shifted by the first continuously variable transmission 10 is input to the transmission 30, .

The output pulley 22 of the second continuously variable transmission 20 is coupled with a power take-off device 60 that draws power to the working device 70 such as an atomizer or a transfer machine. The power take-off device 60 includes a hydraulic pump 61 driven by the second CVT 20 to pressurize the hydraulic medium, a hydraulic pump 61 driven by the hydraulic medium, And a branch circuit 63 for branching the hydraulic pressure from the first hydraulic motor 62 to be driven and the hydraulic pressure from the hydraulic pump 61 to the second hydraulic motor 40 mounted on the transmission 30 for traveling . In this embodiment, the power take-off device 60 is driven by the second continuously variable transmission 20, which is a belt-type continuously variable transmission, but may be directly attached to the output shaft 2 of the engine or may be driven through a gear type speed reducing device or the like.

The housing of the transmission 30 is provided with a forward-reverse transmission mechanism, a high-low speed transmission mechanism, and a differential device (100 in FIG. 2) for distributing power to both drive shafts 50. On both sides of the housing of the transmission 30, A housing (50) of a drive shaft which is transmitted to the drive wheel by the power distributed by the differential device is provided.

The second hydraulic motor 40 driven by the hydraulic pressure generated by the power take-off unit 60 is coupled to the transmission 30. The hydraulic medium from the power take-off unit 60 is supplied to the second hydraulic motor 40 to receive the power of the transmission 30 by the rotation of the second hydraulic motor 40.

Next, the configuration and operation of the transmission 30 of the present embodiment will be described with reference to Figs. 2 to 5. Fig.

2, an input shaft 32, an input shaft 32, or a second hydraulic motor 32, which is coupled with the output shaft pulley (12 in Fig. 1) of the first continuously variable transmission 10 in this order from top to bottom in the transmission housing 31, The idle shaft 33 that receives the power from the drive shaft 40 (shown in FIG. 1) 40 and transfers the idle shaft 33 to the differential device 100 is disposed in parallel with the input shaft 32, and the idle shaft 33 The differential device 100 that is driven by the differential cage 120 and distributes the power to the drive wheels of the working vehicle is disposed such that the rotation axis of the differential cage 120 is parallel to the rotation axis of the input shaft 32 and the idle shaft 33 .

First, the configuration that is disposed on the input shaft 32 and the input shaft will be described.

A first chain sprocket 321 constituting a power transmission element for reverse movement is coupled to one side of the input shaft 32 in a state in which the first chain sprocket 321 is rotatable with respect to the input shaft 32 by a needle bay ring 3211, The forward gear set 322 is coupled to the input shaft 32 in a freely rotatable manner by the needle bearings 3221. The forward gear set 322 is provided with the first gear 323 And a second gear 324 having a diameter larger than that of the first gear. A helical gear is formed on the outer diameter side of the first gear 323 and the second gear 324.

A first sleeve connector 325 which surrounds the input shaft 32 is provided between the first chain sprocket 321 and the forward gear set 322 on the input shaft 32 so as to be movable laterally along the input shaft 32 And is disposed movably in the left and right direction by a fork 326 coupled to the outside of the transmission housing 31. [

A spline engaged with the input shaft 32 is formed on the inner diameter side of the first sleeve connector 325. The first chain sprocket 321 and the forward gear set 322 are provided with a spline for engaging with the first sleeve connector 325 And the first sleeve 325 is selectively engaged with the first chain sprocket 321 or the forward gear set 322 as the first sleeve connector 325 is moved to the left or right by the fork 326. [ And may be in a neutral state that does not engage them.

Accordingly, when the first sleeve connector 325 is engaged with the first chain sprocket 321, the rotational force is transmitted to the first chain sprocket 321 through the first sleeve connector 325 as the input shaft 32 rotates, The rotational force is transmitted to the forward gear set 322 via the first sleeve connector 325 as the input shaft 32 rotates.

A second chain sprocket 331 is coupled to one side of the idle shaft 33 together with the first chain sprocket 321 and serves as a power transmission element for reverse movement and an output gear 332 is coupled to the right side thereof. The chain 34 is engaged with the first chain sprocket 321 and the second chain sprocket 331 so as to transmit power from the first chain sprocket 321 to the second chain sprocket 331.

A third gear 333 and a fourth gear 334 are fixed to the idle shaft 33 by the needle bearings 3331 and 3341 on the opposite side of the second chain sprocket 331 and the output gear 332, In the state of being freely rotatable. The third gear 333 is formed to have a larger diameter than the fourth gear 334 and the helical gear is formed on the outer diameter side of the third gear 333 and the fourth gear 334, 2 gear 324 in the first direction.

The first gear 323 and the third gear 333 form the forward low speed gear and the second gear 324 and the fourth gear 334 form the forward high speed gear, Shaft 33 to transmit power at low speed and high speed, respectively.

A second sleeve connector 335 which surrounds the idle shaft 33 is provided between the third gear 333 and the fourth gear 334 in the idle shaft 33 in the left and right directions along the idle shaft 33 (Not shown) protruding out of the transmission housing 31 so as to move leftward and rightward.

A spline for meshing with the idle shaft 33 is formed on the inner diameter side of the second sleeve connector 335 and the third gear 333 and the fourth gear 334 are provided with a spline on the side facing the second sleeve connector 335 The second sleeve connector 335 can be selectively engaged with the third gear 333 or the fourth gear 334 as the spline is formed on the outer diameter and the second sleeve connector 335 moves leftward or rightward by a fork , And may be in a neutral state that does not engage them.

Accordingly, when the second sleeve connector 335 is engaged with the third gear 333, the rotational force of the third gear 333 is transmitted to the idle shaft 33 through the second sleeve connector 335, And the second sleeve connector 335 meshes with the fourth gear 334 so that the rotational force of the fourth gear 334 is transmitted to the idle shaft 33 through the second sleeve connector 335 to achieve a low speed shift.

On the other hand, one end of the idle shaft 33 passes through the transmission housing 31 and extends to the outside. And a spline 336 is formed at the extended end thereof. A second hydraulic motor 40 is coupled to this extended end of the idle shaft 33, which is shown in Fig.

Referring to FIG. 3, a mounting bracket 315 for mounting a second hydraulic motor 40 is coupled to the transmission housing 31, and a second hydraulic motor 40 is coupled to the mounting bracket 315.

The output shaft 41 of the second hydraulic motor 40 is machined by splines and faces the end of the idle shaft 33 so that the output shaft 41 and the spline 336 at the end of the idle shaft 33 And the output shaft 41 of the second hydraulic motor 40 and the idle shaft 41 are coaxially coupled to each other so as to transmit power.

The second hydraulic motor 40 is not indispensable to the operation of the transmission according to the present invention. The second hydraulic motor 40 is not required to be operated only by drawing the power from the power take-off device 60 for driving the working device installed in the working vehicle, And can be selectively added to the system. It is not necessary to configure the end of the idle shaft 33 so as to protrude from the outside of the transmission housing 31. In the case where the power of the power take-

The operation of the transmission 30 described above will be described.

Power is transmitted from the engine 1 to the input shaft 32 of the transmission 30 through the first continuously variable transmission 10 so that the input shaft 32 rotates.

First, when the first sleeve connector 325 is engaged with the first chain sprocket 321, the rotation of the input shaft 32 is transmitted to the second chain sprocket 331 through the chain 34 so that the idle shaft 33 is rotated 32 in the same direction. This causes a reverse shift in the transmission.

Next, when the first sleeve connector 325 is engaged with the forward gear set 322, the forward gear set 322 rotates in accordance with the rotation of the input shaft 32, and the first gear 322 of the forward gear set 322 rotates, The third gear 333 and the fourth gear 334, which mesh with the first gear 323 and the second gear 324, respectively, rotate.

If the second sleeve connector 335 of the idle shaft 33 is in the neutral position, the rotational force is not transmitted to the idle shaft 33, despite the rotation of the third gear 333 and the fourth gear 334 And when the second sleeve connector 335 is engaged with either the third gear 333 or the fourth gear 334, the rotation of the input shaft 32 is shifted to a low speed or a high speed respectively and the idle shaft 33 ).

On the other hand, when either one of the first sleeve connector 325 or the second sleeve connector 335 or both of them is in the neutral state, the idle shaft 33 is disconnected from the power transmission from the input shaft 32, The hydraulic motor 40 can be driven to drive the idle shaft 33 to rotate.

The second hydraulic motor 40 is driven by being supplied with the hydraulic medium from the hydraulic pump 61 driven by the second continuously variable transmission 20 via the branching circuit 63, 33 can be driven with the input shaft 32 disconnected. When the idle shaft 33 is driven and rotated as described above, the rotational force is transmitted to the differential device 100 by the output gear 332.

The configuration of the differential apparatus 100 will be described below.

Fig. 4 is a conceptual view showing the operation of the differential apparatus 100 shown in the lower part of Fig. 2 in an easy-to-understand manner.

A differential cage 120 having a first axis 102 parallel to the idle shaft 33 as a rotation axis is rotatably disposed in the differential device 100. The differential cage 120 is provided with an idle shaft 33 The power from the output gear 332 of the transmission 30 is directly transmitted to the differential cage 120. The output gear 332 of the differential cage 120 is connected to the output gear 332 of the differential cage 120,

The differential cage 120 is provided with a stud shaft 122 disposed to rotate together with the stud shaft 122 in a plane perpendicular to the first axis 102. The stud shaft 122 is provided with two first pinions And a gear 130 is attached to the stud shaft 122 freely rotatably.

In the differential cage 120, there are provided two side gears 140 having a first axis 102 as a rotation axis and having bevel gears formed so as to engage and rotate with the two first pinion gears 130.

Accordingly, when the differential cage 120 is rotated by the output gear 332 of the transmission, the first pinion gears 130 rotate about the first axis 102 while the stud shaft 122 rotates, The side gears 140 engaged with the first pinion gears 130 rotate about the first axis 102. [

The left and right drive shafts (not shown) connected to the drive wheels of the working vehicle are coupled to the side gears 140, respectively.

A ring gear 150 formed as a bevel gear is coupled to the outer side of the differential cage 120 with a first axis 102 as a rotation axis.

The second and third pinion gears 160 and 170 are also engaged with the ring gear 150. The second and third pinion gears 160 and 170 are also formed as bevel gears, And a second axis 103, which is a rotation axis thereof, is placed on a plane perpendicular to the first axis 102, which is the first axis.

The second and third pinion gears 160 and 170 engage with the ring gear 150 and rotate as the ring gear 150 rotates. As will be described later, the second and third pinion gears 160 and 170 are driven by a drive shaft coupled to the side gear 140, respectively, and a power take-off device (not shown) different from the drive shaft and the power take- And transmits the power to the vehicle.

A specific configuration of the differential apparatus 100 will be described with reference to Fig. 5, which is a cross-sectional view taken along line A-A in Fig. 2 and Fig.

The output gear 332 of the idle shaft 33 is engaged with the input gear 121 mounted on the differential cage 120 and rotated to rotate the differential cage 120. The output gear 332 and the input gear 121 are disposed in parallel with each other, and thus are formed of a spur gear or a helical gear.

4) of the differential cage 120 is disposed in parallel with the input shaft 32 and the idle shaft 33 of the transmission 30. [ At the substantially center of the differential cage 120 in the direction of the rotation axis, the stud shaft 122 is mounted in such a manner that both ends of the stud shaft 122 are fixed to the differential cage 120 in a plane perpendicular to the rotation axis.

A pair of first pinion gears 130 made of bevel gears are rotatably mounted on the stud shaft 122. A pair of side gears 140 made of bevel gears are rotatably arranged in the differential cage 120 in engagement with the first pinion gears 130. A contact ring 181 constituting a differential lock device is disposed between the side gear 140 and the differential cage 120 on the right side. The contact ring 181 includes an operating ring 182 The differential cage 120 is fixed or unfixed by the pin 183 coupled to the differential cage 120 to provide differential locking or unlocking action.

A ring gear 150 is coupled to the outside of the differential cage 120. The ring gear 150 is formed of a spiral bevel gear and rotates together with the differential cage 120.

The second and third pinion gears 160 and 170, which are formed of bevel gears that rotate along a rotation axis perpendicular to the rotation axis of the differential cage 120 and mesh with the ring gear 150, are disposed to face each other.

The second and third pinion gears 160 and 170 are rotatably supported by the bearings 161, 162, 171 and 172 in the forward and backward directions of the housing 31, And protrudes outward. Although not shown in these drawings, the second pinion gear 160 and the third pinion gear 170 are respectively coupled to a power take-off device (not shown) and a joint or shaft for transmitting power to the other drive shaft.

When the input gear 121 engaged with the output gear 332 of the transmission 30 rotates, the differential cage 120 rotates, so that the side gears 140 rotate to rotate the drive shafts And the ring gear 150 rotates in accordance with the rotation of the differential cage 120 to rotate the second and third pinion gears 160 and 170 so that the power from the engine 1 And distributed to a power take-off device or other drive shaft.

In the above-described embodiment, the differential device 100 is provided with a transmission 30 in a housing (transmission housing 31) and forms a part of the transmission 30 without a separate power transmission mechanism, The apparatus 100 can be disposed in front of or behind the work vehicle together with the engine 1 and the first and second continuously variable transmissions 10 and 20. [

In the configuration in which the engine 1 and the transmission 30 are disposed in front of the vehicle, the front wheel of the working vehicle is driven by the side gear 140 of the differential device 100, and the rear wheel is driven by the third pinion gear 170). &Lt; / RTI >

In this case, the front wheels are driven and driven by the power transmission device including the transmission according to the present invention, and if necessary, the rotational force of the third pinion gear 170 of the differential device 100 is transmitted to the rear drive wheels So that the rear drive wheels can be driven.

A power take-off device (not shown) driven by a power drawn from the power take-off device 70 driven by the first hydraulic motor 62 or the second pinion gear 160 of the differential device 100 Various tasks can be performed.

On the other hand, according to the present invention, the power transmission device including the transmission 30, 100 of the above-described embodiment may be disposed behind the working vehicle together with the engine 1. [ In this case, the rear wheels of the vehicle are driven by the side gears 140 of the differential apparatus 100 provided in the transmission 30, and the second pinion gears 160 or the third pinion gears 170 The power can be distributed and driven by the front wheels.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Are all within the scope of the present invention.

1: Engine 10: 1st continuously variable transmission
20: second continuously variable transmission 30: transmission
40: second hydraulic motor 100: differential device

Claims

1. A transmission for a work vehicle in which power from an engine is input via a continuously variable transmission to perform forward and rearward and high-low-speed shifting,
And a first forward gear set including a first forward power transmission element and a plurality of power transmission gears having different diameters from each other and coupled to each other and integrally rotating, Input shaft; And
And a second forward gear set including a plurality of power transmission gears, which are disposed in parallel with the input shaft and are coupled to an output gear that outputs power to the drive shaft of the working vehicle and a second reverse power transmission element, An idle shaft rotatably disposed;
/ RTI >
The first reverse power transmission element and the second reverse transmission power transmission element are engaged with each other so as to transmit power from the input shaft to the idle shaft while rotating the input shaft and the idle shaft in the same direction,
Wherein the plurality of power transmission gears of the first forward gear set are each engaged with one of the plurality of power transmission gears of the second forward gear set,
The first reverse power transmission element and the first forward gear set are selectively engaged with the input shaft so that power is transmitted from the input shaft to the first reverse power transmission element or the first forward gear set If possible,
Wherein the idle shaft is capable of transmitting power from the input shaft to the idle shaft in such a manner that any one of the plurality of power transmission gears of the second forward gear set is selectively engaged with the idle shaft, .

The method according to claim 1,
Wherein the first and second reverse power transmission elements are chain sprockets engaged with one chain and transmit power from the input shaft to the idle shaft through the chain.

The method according to claim 1 or 2,
Further comprising a differential mechanism disposed in parallel with the input shaft and the idle shaft and transmitting power to the drive shaft of the working vehicle,
Wherein the differential mechanism is provided with an input gear engaged with an output gear of the idle shaft to transmit power from the idle shaft to the differential cage, the input gear being coaxially arranged and coupled to the differential cage.