A multi-gear compound shaft gearbox for tractors

Abstract

The invention relates to a tractor multi-gear compound shaft gearbox, comprising an input shaft and an output shaft; the input shaft is provided with a first driving gear, a second driving gear, a third driving gear, a second shifting meshing sleeve, a fourth driving gear and a fifth driving gear in sequence, and the third driving gear and the fourth driving gear are rotatably mounted on the input shaft; the output shaft is provided with a transition sleeve, a third shifting meshing sleeve and a fifth driven gear in sequence, and the transition sleeve and the fifth driven gear are rotatably mounted on the output shaft, and the transition sleeve is provided with a first driven gear, a first shifting meshing sleeve, a second driven gear, a third driven gear and a fourth driven gear in sequence, and the first driven gear and the second driven gear are rotatably mounted on the transition sleeve; the corresponding driving gear and the driven gear are in a constant meshing state. Since all transmission gears are constantly meshed, there is no switching between gears during the shifting process, the gear meshing strength is good, the precision is high, and the operation is more convenient.

Description

Technical Field

[0001] The invention relates to the field of tractor gearboxes, and in particular to a multi-speed compound shaft gearbox for tractors. Background Art

[0002] The tractor gearbox is mainly composed of a housing, gears, spline shafts, operating mechanisms, etc. Its function is to change the tractor's driving force and driving speed, so that the tractor can move forward or backward, stop and output power when the diesel engine is working. In order for the tractor to adapt to different working conditions and functional needs, it must have more gears; the more gears, the more complex the gearbox, and the higher the cost; due to structural and cost reasons, the gearbox of small and medium horsepower tractors is very compact, with only one input shaft and one output shaft, but in order to achieve more gears, a sliding gear shifting structure is used. Since sliding gear shifting inevitably has a long distance, a large gap, and low gear meshing accuracy, it also causes the gearbox to have the following problems: difficulty in shifting or not being able to shift, gear hitting, automatic gear jumping, excessive transmission noise or knocking, random gear shifting, etc. In severe cases, there may even be serious accidents such as broken teeth and broken shafts. Summary of the invention

[0003] In view of the above problems, the present invention is proposed to provide a tractor multi-speed compound shaft gearbox that overcomes the above problems or at least partially solves the above problems.

[0004] According to one aspect of the present invention, a tractor multi-speed compound shaft gearbox is provided, comprising an input shaft and an output shaft arranged in parallel with each other; the input shaft is provided with a first driving gear, a second driving gear, a third driving gear, a second shifting meshing sleeve, a fourth driving gear and a fifth driving gear in sequence, wherein the second shifting meshing sleeve is mounted on the input shaft in a manner that it can slide axially but cannot rotate relative to each other, the first driving gear and the second driving gear are fixedly mounted on the input shaft, the third driving gear and the fourth driving gear are mounted on the input shaft in a manner that they can rotate but cannot move axially, and the fifth driving gear is directly or indirectly linked to the fourth driving gear; the output shaft is provided with a transition sleeve, a third shifting meshing sleeve and a fifth driven gear in sequence, the transition sleeve and the fifth driven gear are mounted in a manner that they can rotate but cannot move axially The first driven gear, the first shifting meshing sleeve, the second driven gear, the third driven gear and the fourth driven gear are sequentially arranged on the transition sleeve, the first shifting meshing sleeve is mounted on the transition sleeve in an axially slidable and non-rotatable manner, the first driven gear and the second driven gear are mounted on the transition sleeve in a rotatable and non-axially movable manner, and the third driven gear and the fourth driven gear are fixedly mounted on the transition sleeve; the first driving gear and the first driven gear, the second driving gear and the second driven gear, the third driving gear and the third driven gear, the fourth driving gear and the fourth driven gear, and the fifth driving gear and the fifth driven gear are all in a constant meshing state.

[0005] In a possible implementation manner, the fifth driving gear is directly linked to the fourth driving gear, which specifically includes: the fifth driving gear is fixedly connected to the fourth driving gear or is an integral structure.

[0006] In a possible implementation manner, the first driven gear and the second driven gear are respectively provided with first meshing teeth and second meshing teeth that can be coupled to the first shifting meshing sleeve.

[0007] In a possible implementation manner, the transition sleeve and the driven gear are respectively provided with fifth and sixth meshing teeth that can be coupled to the third shifting meshing sleeve.

[0008] In a possible implementation, the transition sleeve includes a transition body, a gear body and a meshing tooth body, the first driven gear, the second driven gear and the first shift meshing sleeve are installed on the transition body, the third driven gear and the fourth driven gear are located on the gear body, and the fifth meshing tooth is located on the meshing tooth body.

[0009] In a possible implementation manner, the first driven gear and the second driven gear are respectively mounted on the transition body via a sixth bearing and a seventh bearing.

[0010] In a possible implementation, a snap ring groove and connecting teeth are provided on the transition body, a shaft clamp is installed in the snap ring groove, the gear body is connected to the transition body through the connecting teeth and is axially limited by the shaft clamp, and the shaft clamp is also used to axially limit the passive gear.

[0011] In a possible implementation, the transition sleeve is installed on the output shaft through the third bearing, the fourth bearing and the fifth bearing, and the output shaft is provided with an axial first lubricating oil channel and a radial second lubricating oil channel leading to the corresponding positions at the bottom of the third bearing, the fourth bearing and the fifth bearing.

[0012] In a possible implementation, it also includes an eighth driving gear and an eighth driven gear in a constant meshing state, the eighth driving gear is mounted on the input shaft in a rotatable but non-axially movable manner, the eighth driven gear is fixedly mounted on the transition sleeve, and the fifth driving gear is fixedly connected to the eighth driving gear or is an integral structure.

[0013] In a possible implementation manner, a sixth driving gear and / or a seventh driving gear are mounted on the input shaft, and the sixth driving gear and / or the seventh driving gear are fixedly connected to the fourth driving gear or are an integral structure; a sixth driven gear meshing with the sixth driving gear and a seventh driven gear meshing with the seventh driving gear are mounted on the output shaft in a rotatable but non-axially movable manner, and a fourth shift engagement sleeve is further provided on the output shaft, and the fourth shift engagement sleeve is mounted on the output shaft in an axially slidable but non-relatively rotatable manner; the sixth driven gear and / or the seventh driven gear are provided with meshing teeth connected to the fourth shift engagement sleeve.

[0014] All transmission gears of the tractor multi-speed compound shaft gearbox adopted by the present invention are always meshed, and there is no switching between gears during the gear shifting process. The gear meshing strength is good, the precision is high, the running noise is small, the gear life is long, the gear shifting distance is short, the action is gentle, and the use and operation are more convenient.

[0015] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0017] Figure 1 A schematic diagram of an embodiment of the present invention;

[0018] Figure 2 for Figure 1 A cross-sectional view of the output shaft;

[0019] Figure 3 Another schematic diagram of the present invention;

[0020] Figure 4 Another schematic diagram of the present invention;

[0021] Description of reference numerals:

[0022] 1-input shaft, 2-output shaft, 3-transition sleeve;

[0023] 21-first limit block, 22-second limit block, 23-engaging gear hub, 24-bearing inner sleeve,

[0024] 201 - first lubricating oil channel, 202 - second lubricating oil channel;

[0025] 213-output gear, 222-four-wheel drive output gear;

[0026] 31-transition body, 32-shaft clamp, 33-gear body, 34-meshing gear body;

[0027] 312- snap ring groove, 313- connecting tooth;

[0028] 41-first driving gear, 42-first driven gear;

[0029] 51-second driving gear, 52-second driven gear;

[0030] 61-third driving gear, 62-third driven gear;

[0031] 71- fourth driving gear, 72- fourth driven gear;

[0032] 73-eighth driving gear, 74-eighth driven gear

[0033] 81-fifth driving gear, 82-fifth driven gear;

[0034] 91-sixth driving gear, 92-sixth driven gear;

[0035] 101-seventh driving gear, 102-seventh driven gear;

[0036] 1001 - first gear shifting engagement sleeve, 1002 - second gear shifting engagement sleeve, 1003 - third gear shifting engagement sleeve, 1004 - fourth gear shifting engagement sleeve;

[0037] 421 - first meshing tooth, 521 - second meshing tooth, 611 - third meshing tooth, 711 - fourth meshing tooth, 341 - fifth meshing tooth, 821 - sixth meshing tooth, 741 - seventh meshing tooth, 331 - eighth meshing tooth;

[0038] 2A-first bearing, 2B-second bearing, 3A-third bearing, 3B-fourth bearing, 3C-fifth bearing, 42A-sixth bearing, 52A-seventh bearing, 82A-eighth bearing. DETAILED DESCRIPTION

[0039] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0040] The terms "comprises" and "having" and any variations thereof in the description embodiments, claims and drawings of the present invention are intended to cover non-exclusive inclusions, for example, including a series of steps or units.

[0041] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0042] Example 1

[0043] like Figure 1 The embodiment of the present invention provides a tractor multi-speed compound shaft gearbox, comprising:

[0044] An input shaft 1 and an output shaft 2 arranged parallel to each other;

[0045] The input shaft 1 is provided with a first driving gear 41, a second driving gear 51, a third driving gear 61, a second shifting sleeve 1002, a fourth driving gear 71 and a fifth driving gear 81 in sequence, the second shifting sleeve 1002 is mounted on the input shaft 1 in a manner that it can slide axially but cannot rotate relative to the input shaft 1, the first driving gear 41 and the second driving gear 51 are fixedly mounted on the input shaft 1, the third driving gear 61 and the fourth driving gear 71 are mounted on the input shaft 1 in a manner that they can rotate but cannot move axially, and the fifth driving gear 81 is fixedly connected to the fourth driving gear 71 or is an integral structure;

[0046] The output shaft 2 is provided with a transition sleeve 3, a third shifting meshing sleeve 1003 and a fifth driven gear 82 in sequence, the transition sleeve 3 and the fifth driven gear 82 are mounted on the output shaft 2 in a rotatable and non-axially movable manner, the third shifting meshing sleeve 1003 is mounted on the output shaft 2 in an axially slidable and non-relatively rotatable manner, the transition sleeve 3 is provided with a first driven gear 42, a first shifting meshing sleeve 1001, a second driven gear 52, a third driven gear 62 and a fourth driven gear 72 in sequence, the first shifting meshing sleeve 1001 is mounted on the transition sleeve 3 in an axially slidable and non-relatively rotatable manner, the first driven gear 42 and the second driven gear 52 are mounted on the transition sleeve 3 in a rotatable and non-axially movable manner, and the third driven gear 62 and the fourth driven gear 72 are fixedly mounted on the transition sleeve 3;

[0047] The first driving gear 41 and the first driven gear 42, the second driving gear 51 and the second driven gear 52, the third driving gear 61 and the third driven gear 62, the fourth driving gear 71 and the fourth driven gear 72, and the fifth driving gear 81 and the fifth driven gear 82 are all in a constant meshing state.

[0048] When the second shift engagement sleeve 1002 moves to the left or right, it can be connected to the adjacent driving gear or driven gear. When the third shift engagement sleeve 1003 moves to the left or right, it can be connected to the adjacent third shift engagement sleeve 1003 or the fifth driven gear 82.

[0049] Figure 1 The fifth driving gear 81 and the fourth driving gear 71 are directly linked.

[0050] Specific stall lines:

[0051] Line 1: 1-41-42-1001-3-1003-2

[0052] Line 2: 1-51-42-1001-3-1003-2

[0053] Line 3: 1-1002-61-62-3-1003-2

[0054] Line 4: 1-1002-71-72-3-1003-2

[0055] Line 5: 1-41-42-1001-3-72-71-81-82-1003-2

[0056] Line 6: 1-51-42-1001-3-72-71-81-82-1003-2

[0057] Line 7: 1-1002-61-62-3-72-71-81-82-1003-2

[0058] Line 8: 1-1002-71-81-82-1003-2

[0059] For the convenience of illustration, the above lines are only marked with codes. The following is an introduction to Line 1:

[0060] The first shifting meshing sleeve 1001 slides to the left, the third shifting meshing sleeve 1003 slides to the left, the input shaft 1 drives the first driving gear 41, the first driving gear 41 drives the first driven gear 42 to rotate, the first driven gear 42 drives the first shifting meshing sleeve 1001, the first shifting meshing sleeve 1001 drives the transition sleeve 3 to rotate, the transition sleeve 3 drives the third shifting meshing sleeve 1003 to rotate, and the third shifting meshing sleeve 1003 drives the output shaft 2 to rotate, so the circuit 1 is: 1-41-42-1001-3-1003-2. The processes of the remaining circuits are similar to this and will not be repeated.

[0061] In one example, the first driven gear 42 and the second driven gear 52 are respectively provided with a first meshing tooth 421 and a second meshing tooth 521 that can be connected to the first shifting meshing sleeve 1001. The first shifting meshing sleeve 1001 can be axially moved to the left or to the right or kept in the middle position to selectively connect the transition sleeve 3 to the driven gear 42 or the driven gear 52 or neither. When it slides axially to the left, it can selectively connect to the driven gear 42. Similarly, when it slides axially to the right, it can selectively connect to the driven gear 52. Since the first shifting meshing sleeve 1001 is installed and connected to the transition sleeve 3, the transition sleeve 3 can selectively connect to the driven gear 42 or the driven gear 52 or neither through the three positions (left, right, and middle) of the axial movement of the first shifting meshing sleeve 1001. Both ends of the input shaft 1 and the output shaft 2 are supported on the side wall of the gearbox body by bearings, and there is no other support in the middle.

[0062] In one example, the third driving gear 61 and the fourth driving gear 71 are respectively provided with a third meshing tooth 611 and a fourth meshing tooth 711 which can be connected with the second shifting meshing sleeve 1002; by axially moving the second shifting meshing sleeve 1002 to the left or to the right or maintaining an intermediate position, the output shaft 1 can be selectively connected with the third driving gear 61 or the fourth driving gear 71 or neither.

[0063] In one example, a fifth meshing tooth 341 and a sixth meshing tooth 821 which can be connected to the third shifting meshing sleeve 1003 are respectively provided on the transition sleeve 3 and the driven gear 82, and the output shaft 2 can be selectively connected to the transition sleeve 3 or the fourth driving gear 71 or neither of them by axially moving the third shifting meshing sleeve 1003 to the left or to the right or maintaining an intermediate position.

[0064] In one example, if Figure 2 The transition sleeve 3 includes a transition body 31, a gear body 33 and a meshing gear body 34, each of which is an integral whole or independent and fixed by installation;

[0065] The first driven gear 42, the second driven gear 52 and the first shift engagement sleeve 1001 are mounted on the transition body 31;

[0066] The third driven gear 62 and the fourth driven gear 72 are located on the gear body 33;

[0067] The fifth meshing tooth 341 is located on the meshing tooth body 34. In this example, in order to facilitate installation and processing, the transition body 31, the gear body 33 and the meshing tooth body 34 are independent parts.

[0068] Illustratively, the first driven gear 42 and the second driven gear 52 are mounted on the transition body 31 via a sixth bearing 42A and a seventh bearing 52A, respectively.

[0069] Exemplarily, the fifth driven gear 82 is also installed on the output shaft 2 through the eighth bearing 82A and the bearing inner sleeve 24, and is limited on both sides by the four-wheel drive output gear 222 installed and fixed on the output shaft and the meshing gear hub 23 connected to the meshing sleeve; the four-wheel drive output gear 222 is meshed with the external four-wheel drive transfer box gear, thereby outputting power to the four-wheel drive transfer box; on the output shaft 2, an output tooth portion 213 is also provided, which will output power to the rear wheel transmission box.

[0070] In one example, a retaining ring groove 312 and connecting teeth 313 are provided on the transition body 31, and a shaft clamp 32 is installed in the retaining ring groove 312. The gear body 33 is connected to the transition body 31 through the connecting teeth 313 and is axially limited by the shaft clamp 32. The shaft clamp 32 is also used to axially limit the passive gear 52.

[0071] Exemplarily, the gear body 33 is provided with an eighth meshing tooth 331 for connecting with the meshing tooth body 34 .

[0072] In one example, the output shaft 2 is supported in the housing by a second bearing 2B and a first bearing 2A. A first limit block 21 and a second limit block 22 are provided at both ends of the transition engagement sleeve 3 on the output shaft 2, wherein the first limit block 21 is located between the first bearing 2A and the transition engagement sleeve, with one side backed against the first bearing 2A and the other side in contact with the transition sleeve 3 and the driven gear 42, limiting them from moving axially outside the bearing.

[0073] In one example, since all gears of the gearbox are constantly meshed gears, all gears are rotating regardless of the gear position. To reduce motion resistance and prevent high temperature, the transition sleeve 3 is installed on the output shaft 2 through the third bearing 3A, the fourth bearing 3B, and the fifth bearing 3C. The output shaft 2 is provided with an axial first lubricating oil channel 201 and a radial second lubricating oil channel 202 leading to the corresponding positions at the bottom of the third bearing 3A, the fourth bearing 3B, and the fifth bearing 3C. In this way, the gears and bearings rotate to drive the oil to create centrifugal force, so that the oil circulates continuously inside the bearings, which can fully lubricate and dissipate heat for the bearings.

[0074] In one example, a four-wheel drive output gear 222 can be installed on the output shaft 2, which can output power to the front wheel transfer case; an output gear portion 213 is provided on the output shaft 2, which will output power to the rear wheel transmission case.

[0075] Example 2

[0076] like Figure 3 On the basis of Example 1, an eighth driving gear 73 and an eighth driven gear 74 in a constant meshing state are added, the eighth driving gear 73 is mounted on the input shaft 1 in a rotatable but non-axially movable manner, the eighth driven gear 74 is fixedly mounted on the transition sleeve 3, and the fifth driving gear 81 is fixedly connected to the eighth driving gear 73 or is an integral structure. The gear position circuit can be 1-1002-71-72-74-73-81-82-1003-2.

[0077] The eighth driven gear 74 is provided with a seventh meshing tooth 741 which can be coupled with the third shifting meshing sleeve 1003 . Figure 3 An example is that the fifth driving gear 81 is indirectly linked with the fourth driving gear 71.

[0078] Example 3

[0079] like Figure 4 On the basis of Example 1, a sixth driving gear 91 and / or a seventh driving gear 101 are mounted on the input shaft 1, and the sixth driving gear 91 and / or the seventh driving gear 101 are fixedly connected to the fourth driving gear 71 or are an integral structure; a sixth driven gear 92 meshing with the sixth driving gear 91 and a seventh driven gear 102 meshing with the seventh driving gear 101 are mounted on the output shaft 2 in a rotatable but non-axially movable manner, and a fourth shift engagement sleeve 1004 is further provided on the output shaft 2, and the fourth shift engagement sleeve 1004 is mounted on the output shaft 2 in an axially slidable but non-rotatable manner; the sixth driven gear 92 and / or the seventh driven gear 102 are provided with meshing teeth connected to the fourth shift engagement sleeve 1004.

[0080] In the above embodiment, the axially slidable but non-rotatable installation of the first gear shift sleeve 1001, the second gear shift sleeve 1002, the third gear shift sleeve 1003 and the fourth gear shift sleeve 1004 can be installed by sliding gears, of course, it can also be installed in other forms, and the installation by sliding gears here is just an example.

[0081] The above specific implementation methods further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific implementation methods of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A multi-speed compound shaft gearbox for a tractor, characterized in that: It comprises an input shaft (1) and an output shaft (2) which are arranged parallel to each other; The input shaft (1) is provided with a first driving gear (41), a second driving gear (51), a third driving gear (61), a second shifting engagement sleeve (1002), a fourth driving gear (71) and a fifth driving gear (81) in sequence, wherein the second shifting engagement sleeve (1002) is mounted on the input shaft (1) in a manner that allows axial sliding but cannot rotate relative to each other, the first driving gear (41) and the second driving gear (51) are fixedly mounted on the input shaft (1), the third driving gear (61) and the fourth driving gear (71) are mounted on the input shaft (1) in a manner that allows rotation but cannot move axially, and the fifth driving gear (81) is directly or indirectly linked to the fourth driving gear (71); The output shaft (2) is provided with a transition sleeve (3), a third gear shift engagement sleeve (1003) and a fifth driven gear (82) in sequence; the transition sleeve (3) and the fifth driven gear (82) are mounted on the output shaft (2) in a rotatable manner but not axially movable; the third gear shift engagement sleeve (1003) is mounted on the output shaft (2) in a axially slidable manner but not relatively rotatable; the transition sleeve (3) is provided with a first driven gear (42), a first gear shift engagement sleeve (1003) and a fifth driven gear (82) in sequence; An engagement sleeve (1001), a second driven gear (52), a third driven gear (62) and a fourth driven gear (72), wherein the first shift engagement sleeve (1001) is mounted on the transition sleeve (3) in a manner that allows axial sliding but not relative rotation, the first driven gear (42) and the second driven gear (52) are mounted on the transition sleeve (3) in a manner that allows rotation but not axial movement, and the third driven gear (62) and the fourth driven gear (72) are fixedly mounted on the transition sleeve (3); The first driving gear (41) and the first driven gear (42), the second driving gear (51) and the second driven gear (52), the third driving gear (61) and the third driven gear (62), the fourth driving gear (71) and the fourth driven gear (72), and the fifth driving gear (81) and the fifth driven gear (82) are all in a constant meshing state; A fifth meshing tooth (341) and a sixth meshing tooth (821) which can be connected to the third shifting meshing sleeve (1003) are respectively provided on the transition sleeve (3) and the fifth driven gear (82); The transition sleeve (3) comprises a transition body (31), a gear body (33) and a meshing tooth body (34); the first driven gear (42), the second driven gear (52) and the first shifting meshing sleeve (1001) are mounted on the transition body (31); the third driven gear (62) and the fourth driven gear (72) are located on the gear body (33); and the fifth meshing tooth (341) is located on the meshing tooth body (34); The transition body (31) is provided with a snap ring groove (312) and connecting teeth (313), a shaft clamp (32) is installed in the snap ring groove (312), the gear body (33) is connected to the transition body (31) through the connecting teeth (313), and is axially limited by the shaft clamp (32), and the shaft clamp (32) is also used to axially limit the second driven gear (52).

2. The tractor multi-speed compound shaft gearbox according to claim 1, characterized in that: The fifth driving gear (81) is directly linked to the fourth driving gear (71), specifically comprising: The fifth driving gear (81) is fixedly connected to the fourth driving gear (71) or is an integral structure.

3. The tractor multi-speed compound shaft gearbox according to claim 1, characterized in that: The first driven gear (42) and the second driven gear (52) are respectively provided with a first meshing tooth (421) and a second meshing tooth (521) which can be connected to the first gear shifting meshing sleeve (1001).

4. The tractor multi-speed compound shaft gearbox according to claim 1, characterized in that: The first driven gear (42) and the second driven gear (52) are respectively mounted on the transition body (31) via a sixth bearing (42A) and a seventh bearing (52A).

5. The tractor multi-speed compound shaft gearbox according to claim 1, characterized in that: The transition sleeve (3) is mounted on the output shaft (2) via a third bearing (3A), a fourth bearing (3B) and a fifth bearing (3C); the output shaft (2) is provided with an axial first lubricating oil passage (201) and a radial second lubricating oil passage (202) leading to corresponding positions at the bottom of the third bearing (3A), the fourth bearing (3B) and the fifth bearing (3C).

6. The tractor multi-speed compound shaft gearbox according to claim 1, characterized in that: It also comprises an eighth driving gear (73) and an eighth driven gear (74) in a constant meshing state, wherein the eighth driving gear (73) is mounted on the input shaft (1) in a rotatable but non-axially movable manner, the eighth driven gear (74) is fixedly mounted on the transition sleeve (3), and the fifth driving gear (81) is fixedly connected to the eighth driving gear (73) or is an integral structure.

7. The tractor multi-speed compound shaft gearbox according to claim 1, characterized in that: The input shaft (1) is provided with a sixth driving gear (91) and / or a seventh driving gear (101), and the sixth driving gear (91) and / or the seventh driving gear (101) are fixedly connected to the fourth driving gear (71) or are an integral structure; a sixth driven gear (92) meshed with the sixth driving gear (91) and a seventh driven gear (102) meshed with the seventh driving gear (101) are mounted on the output shaft (2) in a rotatable but non-axially movable manner; the output shaft (2) is further provided with a fourth shifting engagement sleeve (1004), and the fourth shifting engagement sleeve (1004) is mounted on the output shaft (2) in an axially slidable but non-rotatable manner; the sixth driven gear (92) and / or the seventh driven gear (102) are provided with meshing teeth connected to the fourth shifting engagement sleeve (1004).

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