CN106678291A - Front transmission box, tractor and operation tractor - Google Patents

Abstract

The invention relates to the field of working vehicle structure, aims to solve the problem of difficult design of the transmission structure of the working part of the existing tractor, and provides a front transmission box, a tractor and a working tractor. The front transmission box includes a transmission box body, a power input shaft that is rotatably fitted to the transmission box body, a power output shaft that is spaced from the power input shaft and is rotatably fitted to the transmission box body and has an opposite power output end and a connecting end, and includes a through The hydraulic clutch of the input part and the output part which is arranged on the power output shaft and can realize mutual clutching. The input part is connected to the power input shaft by transmission; the output part is connected to the power output shaft by transmission and can be driven to press the input part under the action of hydraulic pressure to realize transmission engagement, or disengage the input part to realize transmission separation after losing hydraulic pressure. The beneficial effect of the invention is that the design of the transmission structure of the operating mechanism is simple, and the clutch control and operation of the power of the operating mechanism are convenient.

Description

Front transmissions, tractors and work tractors

technical field

The invention relates to the structural field of work vehicles, in particular to a front transmission box. The invention also relates to a tractor equipped with the front transmission box.

Background technique

At present, the combined structure gearbox used on traditional large and medium-sized four-wheel drive tractors is equipped with a traveling system transmission mechanism, a rear axle differential, a central transmission and braking mechanism, a PTO system transmission mechanism and its operating device. , the transmission is enlarged, the weight and manufacturing cost are increased, the manufacturing is complicated, and maintenance work and the like become complicated. It restricts the development of the tractor and also affects its application range. There is only one set of PTO system transmission mechanism in the gearbox, which directly enters the final drive box at the rear end of the tractor without deceleration, and then provides power for agricultural implements after transmission, so the design of the transmission structure is difficult.

Contents of the invention

The present invention aims to provide a front transmission box to solve the problem of difficult design of the transmission structure of the working part of the tractor in the prior art.

Another object of the present invention is to provide a tractor equipped with the above-mentioned front transmission case.

Another object of the present invention is to provide a work tractor equipped with the above-mentioned front transmission case.

Embodiments of the present invention are achieved like this:

A front transmission box comprising:

Transmission box;

The power input shaft is rotatably matched with the transmission box;

The power output shaft and the power input shaft are rotated and matched with the transmission box at a distance from each other, and have opposite power output ends and connecting ends;

The hydraulic clutch includes an input part and an output part that pass through the power output shaft and can realize mutual clutching; the input part is connected to the power input shaft by transmission; the output part is connected by transmission to the power output shaft and can be driven and pressed under the action of hydraulic pressure The input section enables drive engagement, or disengages the input section upon loss of hydraulic pressure for drive disengagement.

In one embodiment of the invention:

Rotary pipe joint, the rotary pipe joint includes a shell and a connecting shaft connected by relative rotation; the connecting shaft is fixedly connected to the connecting end of the power output shaft, and the shell is provided with a hydraulic oil port;

The hydraulic passage includes a first passage arranged on the connecting shaft and a second passage arranged on the power output shaft and communicating with the first passage;

The first channel communicates with the hydraulic oil port, and the second channel communicates with the hydraulic chamber of the hydraulic clutch for providing hydraulic pressure.

In one embodiment of the invention:

The housing includes a housing chamber with an opening at one end, and a pressing member is also provided in the housing chamber. One end of the pressing member elastically abuts against the bottom of the housing chamber, and the other end is sealed and pressed against the corresponding end surface of the connecting shaft;

The outer peripheral surface of one end of the connecting shaft is rotatably matched with the peripheral surface of the accommodating cavity through the bearing.

In one embodiment of the invention:

The inner peripheral surface of the output part is provided with an annular groove, and the two sides of the annular groove are respectively provided with sealing rings that are sealed between the inner peripheral surface of the output part and the outer peripheral surface of the power output shaft;

The second passage includes a blind hole extending from the end face of the connection end of the power output shaft along the axis of the power output shaft, and a radial passage extending along the radial direction of the power output shaft and communicating with the annular groove and the blind hole.

In one embodiment of the invention:

The input part includes a driving disc and a plurality of mutually spaced active friction plates arranged in the driving disc; the active friction plates are slidably arranged along the axial direction of the driving disc, and the driving disc and the active friction plates are driven in a circumferential direction;

The output part includes a driven part that is fitted to the power output shaft for circumferential transmission. The outer circumference of the driven part is provided with a number of driven friction plates. The driven friction plates are slidably arranged along the axial direction of the driven part, and the driven part and the driven friction plate Cooperate in the circumferential transmission;

Each active friction plate and each driven friction plate are arranged crosswise in sequence;

The output part is provided with a sliding cavity facing the active friction plate and the driven friction plate, and a slider is slidably fitted in the sliding cavity, and the sliding block and the inner side of the sliding cavity form a hydraulic cavity for containing hydraulic oil and providing hydraulic pressure; the hydraulic cavity The chamber communicates with the annular groove;

The hydraulic pressure input into the hydraulic chamber from the hydraulic channel can push the slider to slide to push the active friction plate and the driven friction plate to compress axially to realize the joint transmission, unloading the hydraulic pressure from the hydraulic chamber can release the slider to disconnect the active friction plate. Engagement transmission of friction plate and driven friction plate.

In one embodiment of the invention:

The driven part also includes a return spring;

The return spring pushes against the slide block toward the bottom of the sliding cavity, so that the slide block tends to slide toward the bottom of the sliding cavity to release the compression between the driving friction plate and the driven friction plate.

In one embodiment of the present invention, the front transmission case also includes:

The intermediate shaft is fixed relative to the transmission box;

a duplex gear, rotatably connected to the intermediate shaft;

The power input shaft is connected to the input part of the hydraulic clutch through a double gear transmission.

In one embodiment of the invention:

The duplex gear includes a larger first sub-gear and a smaller second sub-gear; the driving gear fixedly connected to the power input shaft meshes with the first sub-gear, and the driven gear that rotates and fits with the power output shaft meshes with the second sub-gear. child gear. The driven gear is fixedly connected to the input part of the hydraulic clutch.

A tractor, which includes the aforementioned front transmission box, the engine transmission of the tractor is connected to the power input shaft of the front transmission box, and can drive the power input shaft to rotate; the power output end of the power output shaft is used to connect the operating mechanism and drive the operation Institutional operations.

An operation tractor, which includes an operation mechanism and the aforementioned front transmission box, the engine of the operation tractor is connected to the power input shaft of the front transmission box, and can drive the power input shaft to rotate; the power output end of the power output shaft is connected to the operation The front end of the frame of the working tractor is also equipped with a front frame, which is located in front of the engine; the front transmission box is fixedly connected to the front frame, and the engine of the working tractor is connected through the universal joint transmission shaft. Power input shaft.

The front transmission box provided by the embodiment of the present invention is used to transmit the power of the tractor to the front end in a clutchable manner, so as to realize the connection and drive of the working mechanism of the front end. The transmission structure of the working mechanism is simple in design, and the clutch control and manipulation of the power of the working mechanism Convenience benefits.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and thus It should be regarded as a limitation on the scope, and those skilled in the art can also obtain other related drawings based on these drawings without creative work.

Fig. 1 is the perspective view of the tractor in the first embodiment of the present invention;

Fig. 2 is the view of the first angle of view of Fig. 1;

Fig. 3 is the view of the second viewing angle of Fig. 1;

Fig. 4 is the view of the third viewing angle of Fig. 1;

Fig. 5 is a schematic diagram of the connection structure between the engine and the transmission case in Fig. 1;

Fig. 6 is a schematic structural view of the front transmission box in Embodiment 1 of the present invention;

Fig. 7 is a sectional view of Fig. 6;

Fig. 8 is a schematic structural view of the hydraulic clutch in Fig. 5;

Fig. 9 is a schematic structural view of the rotary pipe joint in Fig. 5;

Fig. 10 is a structural view of the working tractor in the second embodiment of the present invention.

Icons: 001-working tractor; 010-tractor; 1-transmission box; 100-front transmission box; 11-hydraulic clutch; 11.1-driven part; 11.2-driven friction plate; 11.3-driving disc; 11.4-active friction 11.5-slider; 11.6-return spring; 11.7-push rod; 11.8-end block; 12-rotary pipe joint; 12.1-connecting shaft; 12.2-shell; 12.3-hydraulic oil port; -pressing part; 18-duplex gear; 18.1-first sub-gear; 18.2-second sub-gear; 19-key; 20-driven gear; 24-power output shaft; 25-shield; 3-bearing; 4-Oil seal seat; 5-Oil seal; 6-Power input shaft; 6.1-Drive gear; 9-Intermediate shaft; B1-Input part; B2-Output part; D0-Power input end; D1-Power output end; D2-Connection End; F1-sealing ring; J1-operating mechanism; K0-hydraulic channel; K1-first channel; K2-second channel; K3-annular groove; K4-blind hole; K5-radial channel; K6-air vent; Q1-hydraulic chamber; Q2-accommodating chamber; Q3-sliding chamber; R1-frame; R2-front frame; R3-engine; R4-cardan shaft; R5-walking components.

detailed description

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments It is a part of embodiments of the present invention, but not all embodiments. The components of the embodiments of the invention generally described and illustrated in the figures herein may be arranged and designed in a variety of different configurations.

Accordingly, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

It should be noted that like numerals and letters denote similar items in the following figures, therefore, once an item is defined in one figure, it does not require further definition and explanation in subsequent figures.

In the description of the present invention, it should be noted that if the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" ” and other indications are based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship that is usually placed when the product of the invention is used. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating Or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as limiting the invention. In addition, if the terms "first", "second" and the like appear in the description of the present invention, they are only used to distinguish the description, and should not be understood as indicating or implying relative importance.

In addition, terms such as "horizontal" and "vertical" in the description of the present invention do not mean that the components are required to be absolutely horizontal or hang, but may be slightly inclined. For example, "horizontal" only means that its direction is more horizontal than "vertical", and it does not mean that the structure must be completely horizontal, but can be slightly inclined.

Embodiment one

Fig. 1 is a perspective view of a tractor 010 in an embodiment of the present invention; Fig. 2 is a view of a first angle of view of Fig. 1; Fig. 3 is a view of a second angle of view of Fig. 1; Fig. 4 is a view of a third angle of view of Fig. 1 , and the four figures respectively show the structure of the tractor 010 in this embodiment from different perspectives.

Please mainly refer to Fig. 1 (see Fig. 2, Fig. 3 and Fig. 4 for cooperation), the tractor 010 in this embodiment includes a driving structure composed of a vehicle frame R1, an engine R3, a running assembly R5, etc., and also includes a front transmission box 100 . On the one hand, the engine R3 of the tractor 010 is connected to the running assembly R5 to drive the tractor 010 to move; The power output end D1 of the power output shaft 24 is used to connect the working mechanism and drive the working mechanism to operate. The operating mechanism here may be a mechanism for snow removal, a mechanism for harvesting crops, and a mechanism for other operations. Preferably, the front end of the vehicle frame R1 is further provided with a front frame R2, and the front frame R2 is located in front of the engine R3. The front transmission box 100 is fixedly connected to the front frame R2.

Wherein, please refer to FIG. 5 , the connection between the engine R3 and the front transmission case 100 is: the forward output shaft of the engine R3 and the power input shaft 6 of the front transmission case 100 are connected through a cardan shaft R4 . When the engine R3 is running, it can drive the front transmission case 100 and the operating mechanism connected to the front transmission case 100 to perform operations. Preferably, the power output end D1 of the power output shaft 24 of the front transmission case 100 is set forward, so as to facilitate the setting of the connection between it and the working mechanism.

FIG. 6 is a schematic structural view of the front transmission case 100 in the embodiment of the present invention; FIG. 7 is a cross-sectional view of FIG. 6 . Please refer to FIG. 6 and FIG. 7 , the front transmission box 100 in this embodiment includes a transmission box body 1 , a power input shaft 6 , a power output shaft 24 , a hydraulic clutch 11 and a rotary pipe joint 12 .

Referring to FIG. 7 , the power input shaft 6 is rotatably fitted to the transmission case 1 ; the power output shaft 24 and the power input shaft 6 are rotatably fitted to the transmission case 1 at a distance from each other, and have opposite power output ends D1 and connecting ends D2 . The hydraulic clutch 11 includes an input part B1 and an output part B2 passing through the power output shaft 24 and capable of clutching each other. The input part B1 is transmission-connected to the power input shaft 6; the output part B2 is transmission-connected to the power output shaft 24 and can drive and press the input part B1 to achieve transmission engagement under the action of hydraulic pressure, or disengage the input part B1 after losing the hydraulic pressure Realize transmission separation. Optionally, the output part B2 is drivingly connected to the power output shaft 24 through the key 19 .

Please continue to refer to FIG. 7 , in one embodiment of the embodiment of the present invention, the front transmission case 100 further includes an intermediate shaft 9 fixedly arranged relative to the transmission case body 1 and a double gear 18 rotatably connected to the intermediate shaft 9 . The dual gear 18 includes a larger first sub-gear 18.1 and a smaller second sub-gear 18.2; the driving gear 6.1 fixedly connected to the power input shaft 6 meshes with the first sub-gear 18.1, and is rotatably matched to the power output shaft 24. The driven gear 20 meshes with the second sub-gear 18.2. The hydraulic clutch 11 is clutchably connected between the driven gear 20 and the power output shaft 24 , so that the power input shaft 6 is connected to the input part B1 of the hydraulic clutch 11 through the dual gear 18 . Optionally, a rotation limit is set between one end of the intermediate shaft 9 and the transmission case body 1, and the axial stop is carried out by an axial retaining ring, so that the intermediate shaft 9 and the transmission case body 1 are relatively static; The gear 18 is rotatably fitted to the intermediate shaft 9 through a needle bearing.

The transmission ratio between the power input shaft 6 and the power output shaft 24 can be conveniently set and adjusted through the arrangement of the intermediate shaft 9 and the power transmission of the dual gear 18 .

The power input end D0 of the aforementioned power input shaft 6, the power output end D1 of the power output shaft 24, and the connecting end D2 of the power output shaft 24 all have certain radial fluctuations. Two ends are sealed with oil seal 5 and oil seal seat 4 respectively.

FIG. 8 is a detailed view of the hydraulic clutch 11 in FIG. 7 . Please refer to Fig. 8 (see Fig. 7 for cooperation), the inner peripheral surface of the output part B2 of the hydraulic clutch 11 in this embodiment is provided with an annular groove K3, and the two sides of the annular groove K3 are respectively provided with an inner periphery sealed with the output part B2 The sealing ring F1 between the surface and the outer peripheral surface of the power output shaft 24. The second channel K2 includes a blind hole K4 extending from the end face of the connecting end D2 of the power output shaft 24 along the axis of the power output shaft 24, and a diameter extending along the radial direction of the power output shaft 24 and communicating with the annular groove K3 and the blind hole K4. to channel K5.

The input part B1 of the hydraulic clutch 11 in this embodiment includes a driving disc 11.3 and a plurality of mutually spaced active friction plates 11.4 arranged in the driving disc 11.3; the active friction plates 11.4 are slidably arranged along the axial direction of the driving disc 11.3, and The disk 11.3 and the active friction plate 11.4 are driven and matched in the circumferential direction.

The output part B2 includes a driven part 11.1 that is fitted to the power output shaft 24 in a circumferential transmission. The outer circumference of the driven part 11.1 is provided with a number of driven friction plates 11.2. The driven friction plates 11.2 are slidably arranged along the axial direction of the driven part 11.1, and The driven part 11.1 and the driven friction plate 11.2 are driven and fitted in the circumferential direction. Each driving friction plate 11.4 and each driven friction plate 11.2 are sequentially arranged crosswise. The output part B2 is provided with a sliding cavity Q3 facing the active friction plate 11.4 and the driven friction plate 11.2. The sliding block 11.5 is slidably fitted in the sliding cavity Q3. The sliding block 11.5 and the inner side of the sliding cavity Q3 are used to accommodate hydraulic oil and provide hydraulic pressure. Force hydraulic chamber Q1; hydraulic chamber Q1 communicates with annular groove K3.

The hydraulic pressure input into the hydraulic chamber Q1 from the hydraulic channel K0 can push the sliding block 11.5 to slide to push the driving friction plate 11.4 and the driven friction plate 11.2 to compress in the axial direction to realize the joint transmission, unloading the hydraulic pressure from the hydraulic chamber Q1 can make the sliding block 11.5 release to disconnect the driving friction plate 11.4 and driven friction plate 11.2 engagement drive. Optionally, the driven part 11.1 also includes a return spring 11.6; the return spring 11.6 pushes against the slider 11.5 toward the bottom of the sliding chamber Q3, so that the slider 11.5 tends to slide toward the bottom of the sliding chamber Q3 to release the active friction plate Press fit between 11.4 and driven friction plate 11.2. The return spring 11.6 can be arranged in a way that the slide block 11.5 and the output part B2 opposite to the slide block 11.5 are slotted, and the two ends of the return spring 11.6 are respectively arranged in the grooves to realize the movement from the driven part 11.1 to the slide block 11.5. The direction of realizes the support to slide block 11.5. In order to realize that the space between the sliding chamber Q3 and the hydraulic chamber Q1 can maintain atmospheric pressure, a vent K6 is provided on the inner wall of the driven part 11.1.

In order to realize the push of the slider 11.5 to the driving friction plate 11.4 and the driven friction plate 11.2, one end is connected to the slider 11.5, and the other end passes through the sliding chamber Q3 in the direction of the driving friction plate 11.4 and the driven friction plate 11.2 and faces the driving friction plate 11.4. The push rod 11.7 of the friction plate 11.4 and the driven friction plate 11.2. Preferably, an end block 11.8 is connected to the end of the push rod 11.7 for directly contacting the driving friction plate 11.4 or the driven friction plate 11.2. The push rod 11.7 and the end block 11.8 can be connected to the slide block 11.5 by screws.

In order to facilitate the installation of the slider 11.5, the driven part 11.1 is configured as a separate structure, one part is provided with a groove, and the other part is detachably connected and covers the groove.

Fig. 9 is a schematic structural view of the rotary pipe joint 12 in the embodiment of the present invention. Please refer to FIG. 9 , the rotary pipe joint 12 in the embodiment of the present invention includes a shell 12.2 and a connecting shaft 12.1 which are relatively rotatably connected. The housing 12.2 includes a housing chamber Q2 with one end open, and a pressing piece 12.5 is also provided in the housing chamber Q2. One end of the pressing piece 12.5 elastically abuts against the bottom of the housing chamber Q2, and the other end is sealed and pressed against the corresponding end surface of the connecting shaft 12.1. . The outer peripheral surface of one end of the connecting shaft 12.1 is rotatably matched with the peripheral surface of the accommodation cavity Q2 through the bearing 3 .

The connecting shaft 12.1 is fixedly connected to the connecting end D2 of the power output shaft 24, and the casing 12.2 is provided with a hydraulic oil port 12.3. Please refer to FIG. 7 , the connecting shaft 12.1 is provided with a first channel K1, and the power output shaft 24 is provided with a second channel K2 communicating with the first channel K1. The first channel K1 communicates with the hydraulic oil port 12.3, and the second channel K2 communicates with the hydraulic chamber Q1 of the hydraulic clutch 11 for providing hydraulic pressure. The first channel K1 and the second channel K2 communicate to form a hydraulic channel K0. Therefore, the hydraulic channel K0 communicates with the hydraulic oil port 12.3 and the hydraulic chamber Q1.

When in use, hydraulic oil can be introduced into the hydraulic chamber Q1 from the hydraulic oil port 12.3 through the hydraulic channel K0 to provide hydraulic pressure for driving the hydraulic clutch 11 to drive and engage. And because of the existence of the rotary pipe joint 12 , even when the power output shaft 24 is rotating, the hydraulic channel K0 can still be sealed and communicated with the hydraulic chamber Q1 , so as to control the clutching of the hydraulic clutch 11 . The housing 12.2 is also provided with vent holes 12.4 for removing the gas inside the housing 12.2.

For the convenience of connection, the hydraulic oil port 12.3 is provided with an internal thread for connecting with an external pipeline.

In addition, when the front transmission box 100 is not in use temporarily, a protective cover 25 can be installed outside the power output end D1 of the power output shaft 24 to protect the power output end D1.

Embodiment two

Fig. 10 is a schematic structural view of the working tractor 001 in the second embodiment of the present invention. Please refer to FIG. 10 , the working tractor 001 in the first embodiment includes the working mechanism J1 and the front transmission box 100 described in the first embodiment, and the engine R3 of the working tractor 001 is connected to the power input shaft 6 of the front transmission box 100 through transmission. , and can drive the power input shaft 6 to rotate. The power output end D1 of the power output shaft 24 is transmission-connected to the working mechanism J1 and drives the working mechanism J1 to operate.

The working tractor 001 in this embodiment is a working machine with an additional working mechanism J1 on the basis of the tractor 010 in the first embodiment, so as to realize the working at the front end of the tractor 010 .

Preferably, the front end of the frame R1 of the working tractor 001 is further provided with a front frame R2, and the front frame R2 is located in front of the engine R3. The front transmission box 100 is fixedly connected to the front frame R2, and the engine R3 of the working tractor 001 is connected to the power input shaft 6 via the cardan shaft R4.

The front frame R2 can be used to install the front transmission box 100 on the one hand, and can be used to install and support the working mechanism J1 on the other hand. When in use, the base of the working mechanism J1 can be fixedly connected to the top of the front frame R2, and then the power output shaft 24 of the front transmission box 100 is connected to the input end of the working mechanism J1 through the transmission structure to realize the operation of the driving working mechanism J1.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. A front transmission box, characterized in that, comprising: Transmission box; The power input shaft is rotatably matched with the transmission case; The power output shaft is rotatably fitted to the transmission case at a distance from the power input shaft, and has an opposite power output end and a connecting end; The hydraulic clutch includes an input part and an output part that pass through the power output shaft and can realize mutual clutching; the input part is drive-connected to the power input shaft; the output part is drive-connected to the power output shaft and Under the action of the hydraulic pressure, the input part can be driven and pressed to realize the transmission engagement, or the input part can be disengaged after the hydraulic pressure is lost to realize the transmission separation. 2. The front transmission case according to claim 1, further comprising: A rotary pipe joint, the rotary pipe joint includes a shell and a connecting shaft that are relatively rotatably connected; the connecting shaft is fixedly connected to the connecting end of the power output shaft, and the shell is provided with a hydraulic oil port; a hydraulic channel, including a first channel provided on the connecting shaft and a second channel provided on the power output shaft and communicating with the first channel; The first passage communicates with the hydraulic oil port, and the second passage communicates with a hydraulic chamber of the hydraulic clutch for providing the hydraulic pressure. 3. The front transmission box according to claim 2, characterized in that: The housing includes an accommodating chamber with an open end, and a pressing member is also provided in the accommodating chamber, one end of the pressing member elastically abuts against the bottom of the accommodating chamber, and the other end is sealed and pressed against the corresponding connecting shaft. one end face of The outer peripheral surface of one end of the connecting shaft is rotatably matched with the peripheral surface of the accommodating cavity through a bearing. 4. The front transmission case according to claim 2, characterized in that: The inner peripheral surface of the output part is provided with an annular groove, and the two sides of the annular groove are respectively provided with sealing rings sealed between the inner peripheral surface of the output part and the outer peripheral surface of the power output shaft; The second passage includes a blind hole extending from the end face of the connecting end of the power output shaft along the axis of the power output shaft, and a blind hole extending along the radial direction of the power output shaft and communicating with the annular groove and the blind hole. radial channel of the hole. 5. The front transmission box according to claim 4, characterized in that: The input part includes a driving disc and a plurality of mutually spaced active friction plates arranged in the driving disc; the active friction plates are slidably arranged along the axial direction of the driving disc, and the driving disc and the active friction plates Cooperate in the circumferential transmission; The output part includes a driven part that is fitted to the power output shaft in a circumferential direction, and the outer circumference of the driven part is provided with a number of driven friction plates, and the driven friction plates are slidable along the axial direction of the driven part set, and the driven part and the driven friction plate are driven in a circumferential direction; Each of the active friction plates and each of the driven friction plates are arranged in a cross sequence; The output part is provided with a sliding cavity facing the driving friction plate and the driven friction plate, a sliding block is slidably fitted in the sliding cavity, and the sliding block is enclosed with the inner side of the sliding cavity for accommodating hydraulic pressure. oil and provide the hydraulic chamber of the hydraulic pressure; the hydraulic chamber communicates with the annular groove; The hydraulic pressure input into the hydraulic chamber from the hydraulic channel can push the sliding block to slide to push the driving friction plate and the driven friction plate to compress in the axial direction to realize the joint transmission and unload from the hydraulic chamber Hydraulic pressure is capable of disengaging the slider to disengage the engagement drive of the driving and driven friction plates. 6. The front transmission box according to claim 5, characterized in that: The driven part also includes a return spring; The return spring presses against the slider towards the bottom of the sliding cavity, so that the slider tends to slide towards the bottom of the sliding cavity to loosen the gap between the active friction plate and the driven friction plate. of pressing. 7. The front transmission case according to claim 1, further comprising: The intermediate shaft is fixed relative to the transmission box; a duplex gear rotatably connected to said intermediate shaft; The power input shaft is connected to the input part of the hydraulic clutch through the dual gear transmission. 8. The front transmission case according to claim 7, characterized in that: The dual gear includes a larger first sub-gear and a smaller second sub-gear; the driving gear fixedly connected to the power input shaft meshes with the first sub-gear, and is rotatably matched with the power output shaft The driven gear meshes with the second sub-gear; The driven gear is fixedly connected to the input part of the hydraulic clutch. 9. A tractor, characterized in that: Said tractor comprises a front transmission box as claimed in any one of claims 1-8, said tractor's engine transmission is connected to the power input shaft of said front transmission box, and can drive said power input shaft to rotate; The power output end of the power output shaft is used to connect the working mechanism and drive the working mechanism to operate. 10. An operating tractor, characterized in that: The working tractor includes a working mechanism and the front transmission box according to any one of claims 1-8, the engine of the working tractor is connected to the power input shaft of the front transmission box, and can drive the power input shaft rotation; The power output end of the power output shaft is connected to the operating mechanism through transmission and drives the operating mechanism to operate; The front end of the frame of the working tractor is also provided with a front frame, and the front frame is located in front of the engine; The front transmission box is fixedly connected to the front frame, and the engine of the work tractor is connected to the power input shaft through a cardan shaft.