Gearbox and extrusion device

Abstract

The invention belongs to the technical field of gear boxes, and discloses a gear box and an extrusion device.The gear box comprises a box body, an input gear shaft, a transmission assembly and an output assembly. The input gear shaft is rotationally connected to the box body, the output assembly comprises a first output shaft and a second output shaft which are parallel to each other and arranged at intervals, the first output shaft and the second output shaft are connected to the input gear shaft through the transmission assembly, and when the input gear shaft rotates, the first output shaft and the second output shaft rotate around the axes of the first output shaft and the second output shaft correspondingly. And the rotating direction of the first output shaft is opposite to that of the second output shaft. The extrusion device comprises a driving mechanism and a gearbox, and the output end of the driving mechanism is connected to the input gear shaft and can drive the input gear shaft to rotate. By means of the arrangement, the gearbox can meet the requirements for parallel transmission output and different-direction rotation of double screws in extrusion devices such as a double-screw extruder.

Description

Technical Field

[0001] The present invention relates to the technical field of gear boxes, and in particular to a gear box and an extrusion device. Background Art

[0002] The twin-screw extruder is developed on the basis of the single-screw extruder. It has good feeding performance, mixing and plasticizing performance, exhaust performance, extrusion stability and other characteristics, and has been widely used in the molding processing of extruded products.

[0003] Based on the process requirements of screw extrusion, the twin-screw extruder needs to achieve parallel transmission output of twin-screw extrusion, but the gearbox currently matched with the twin-screw extruder cannot meet the requirements of parallel transmission output and angular rotation of the twin screws. Therefore, a gearbox is urgently needed to solve the above technical problems. Summary of the invention

[0004] The object of the present invention is to provide a gear box which can meet the requirements for parallel transmission output and counter-rotation of twin screws in extrusion devices such as twin screw extruders.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] A gearbox comprising:

[0007] Box;

[0008] An input gear shaft, rotatably connected to the housing;

[0009] Transmission components;

[0010] The output assembly includes a first output shaft and a second output shaft which are parallel to each other and spaced apart. The first output shaft and the second output shaft are both connected to the input gear shaft through the transmission assembly. When the input gear shaft rotates, the first output shaft and the second output shaft respectively rotate around their own axes, and the rotation direction of the first output shaft is opposite to the rotation direction of the second output shaft.

[0011] Optionally, the transmission assembly includes a first transmission assembly, a second transmission assembly and a third transmission assembly, the first transmission assembly is connected to the input gear shaft, and is connected to the second transmission assembly and the third transmission assembly, the second transmission assembly is configured to be connected to the first output shaft, and the third transmission assembly is configured to be connected to the second output shaft, and when the input gear shaft rotates, the second transmission assembly and the third transmission assembly are driven to rotate through the first transmission assembly.

[0012] Optionally, the first transmission assembly includes a first transmission shaft, a first gear, a second transmission shaft and a second gear, the first transmission shaft and the second transmission shaft are both rotatably connected to the housing, the first gear is disposed on the first transmission shaft and meshingly connected to the input gear shaft, the second gear is disposed on the second transmission shaft and meshingly connected to the first transmission shaft, and the second transmission shaft is configured to be connected to the second transmission assembly and the third transmission assembly.

[0013] Optionally, the first transmission shaft and the second transmission shaft are parallel to each other and spaced apart.

[0014] Optionally, the second transmission assembly includes a first connecting shaft and a third gear, the first connecting shaft is rotatably connected to the housing, the third gear is disposed on the first connecting shaft and meshingly connected to the second transmission shaft, and the first connecting shaft is configured to be connected to the first output shaft.

[0015] Optionally, the first connecting shaft includes a first spline shaft and a second spline shaft, wherein the second spline shaft is key-connected to the first spline shaft and is coaxially arranged with the first spline shaft, and is configured to be connected to the first output shaft.

[0016] Optionally, the third transmission assembly includes a second connecting shaft, a fourth gear and a third connecting shaft, the second connecting shaft and the third connecting shaft are both rotatably connected to the housing, the fourth gear is disposed on the second connecting shaft and meshingly connected to the second transmission shaft, and the third connecting shaft is meshingly connected to the second connecting shaft and is configured to be connected to the second output shaft.

[0017] Optionally, the second connecting shaft includes a third spline shaft, a fourth spline shaft and a connecting piece, the third spline shaft is connected to the fourth spline shaft through the connecting piece and is coaxially arranged with the fourth spline shaft, and the fourth spline shaft is configured to be meshingly connected to the third connecting shaft.

[0018] Optionally, the box body is provided with an oil outlet, the interior of the box body is connected to the outside through the oil outlet, and a control valve is provided at the oil outlet.

[0019] Another object of the present invention is to provide an extrusion device that can meet the requirements of parallel transmission output and counter-rotation of twin screws.

[0020] To achieve this object, the present invention adopts the following technical solutions:

[0021] An extrusion device comprises a driving mechanism and the gear box as described above, wherein the output end of the driving mechanism is connected to the input gear shaft and can drive the input gear shaft to rotate.

[0022] Beneficial effects of the present invention:

[0023] The present invention provides a gearbox and an extrusion device, wherein the gearbox comprises a housing, an input gear shaft, a transmission assembly and an output assembly. The input gear shaft is rotatably connected to the housing, ensuring effective input of power. The output assembly comprises a first output shaft and a second output shaft which are parallel to each other and arranged at intervals, meeting the requirements of extrusion devices such as twin-screw extruders for parallel transmission output. The first output shaft and the second output shaft are both connected to the input gear shaft through the transmission assembly. When the input gear shaft rotates, the first output shaft and the second output shaft rotate around their own axes respectively, and the rotation direction of the first output shaft is opposite to the rotation direction of the second output shaft, thereby realizing the skew rotation of the first output shaft and the second output shaft. The extrusion device comprises a driving mechanism and a gearbox, wherein the output end of the driving mechanism is connected to the input gear shaft, and can drive the input gear shaft to rotate. Through the above arrangement, the gearbox of the present application can meet the requirements of parallel transmission output and skew rotation of twin screws in extrusion devices such as twin-screw extruders. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is an axonometric diagram of a gearbox provided by an embodiment of the present invention;

[0025] Figure 2 is a top view of a gear box provided by an embodiment of the present invention;

[0026] Figure 3 is a front view of a gear box provided by an embodiment of the present invention;

[0027] Figure 4 yes Figure 3 Cross-section at AA in the middle;

[0028] Figure 5 yes Figure 3 Cross-section view at the middle BB.

[0029] In the figure:

[0030] 1. Box body; 11. Oil outlet; 2. Input gear shaft; 3. Transmission assembly; 31. First transmission assembly; 311. First transmission shaft; 312. First gear; 313. Second transmission shaft; 314. Second gear; 32. Second transmission assembly; 321. First connecting shaft; 3211. First spline shaft; 3212. Second spline shaft; 322. Third gear; 33. Third transmission assembly; 331. Second connecting shaft; 3311. Third spline shaft; 3312. Fourth spline shaft; 3313. Connector; 332. Fourth gear; 333. Third connecting shaft; 4. Output assembly; 41. First output shaft; 42. Second output shaft; 5. Control valve. DETAILED DESCRIPTION

[0031] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0032] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0034] In the description of this embodiment, the terms "upper", "lower", "right" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0035] like Figure 1-Figure 5 As shown, this embodiment provides a gearbox, which includes a housing 1, an input gear shaft 2, a transmission assembly 3 and an output assembly 4. The input gear shaft 2 is rotatably connected to the housing 1, the transmission assembly 3 is arranged in the housing 1, and the output assembly 4 includes a first output shaft 41 and a second output shaft 42 that are parallel to each other and spaced apart. The first output shaft 41 and the second output shaft 42 are both connected to the input gear shaft 2 through the transmission assembly 3. When the input gear shaft 2 rotates, the first output shaft 41 and the second output shaft 42 rotate around their own axes respectively, and the rotation direction of the first output shaft 41 is opposite to the rotation direction of the second output shaft 42.

[0036] In this embodiment, the input gear shaft 2 is rotatably connected to the housing 1, ensuring effective input of power. The output assembly 4 includes a first output shaft 41 and a second output shaft 42 which are parallel to each other and spaced apart, meeting the requirements of the extrusion device such as the twin-screw extruder for parallel transmission output. The first output shaft 41 and the second output shaft 42 are both connected to the input gear shaft 2 through the transmission assembly 3. When the input gear shaft 2 rotates, the first output shaft 41 and the second output shaft 42 rotate around their own axes respectively, and the rotation direction of the first output shaft 41 is opposite to the rotation direction of the second output shaft 42, thereby achieving the first output shaft 41 and the second output shaft 42 rotating in different directions. The extrusion device includes a driving mechanism and a gear box, and the output end of the driving mechanism is connected to the input gear shaft 2, which can drive the input gear shaft 2 to rotate. Through the above arrangement, the gear box of this embodiment can meet the requirements of the parallel transmission output and different directions of rotation of the twin screws in the extrusion device such as the twin-screw extruder.

[0037] The specific structure of the gearbox is described below:

[0038] Specifically, Figure 1-Figure 4 As shown, the input gear shaft 2 is connected to the drive assembly through a coupling, and the coupling can transmit torque and rotational motion, while allowing certain axial and radial displacements, so as to compensate for the installation error between the drive assembly and the input gear shaft 2 and the deformation generated during operation. The input gear shaft 2 is passed through the housing 1, and the sealing effect is achieved through the sleeve, oil seal and pressure ring, which can effectively prevent the leakage of the lubricating oil in the housing 1 and prevent foreign impurities from entering the interior of the housing 1, thereby ensuring the normal operation and service life of the gearbox. Moreover, the transparent cover is connected to the housing 1 and the input gear shaft 2, so that the connection between the input gear shaft 2 and the housing 1 is tight, ensuring the operational safety of the gearbox. Among them, the drive assembly includes a servo motor or a stepper motor, as long as it can provide a rotational driving force for the input gear shaft 2, and the specific structure of the drive assembly is not limited too much here.

[0039] Specifically, Figure 4 and Figure 5As shown, the transmission assembly 3 includes a first transmission assembly 31, a second transmission assembly 32 and a third transmission assembly 33. The first transmission assembly 31 is connected to the input gear shaft 2, and is connected to the second transmission assembly 32 and the third transmission assembly 33. The second transmission assembly 32 is configured to be connected to the first output shaft 41, and the third transmission assembly 33 is configured to be connected to the second output shaft 42. When the input gear shaft 2 rotates, the first transmission assembly 31 drives the second transmission assembly 32 and the third transmission assembly 33 to rotate, and then the second transmission assembly 32 rotates to drive the first output shaft 41 to rotate around its own axis, and the third transmission assembly 33 rotates to drive the second output shaft 42 to rotate around its own axis. When the driving assembly drives the input gear shaft 2 to rotate, the above-mentioned arrangement ensures that the power is stably transmitted to the second transmission assembly 32 and the third transmission assembly 33 via the first transmission assembly 31, and then drives the first output shaft 41 and the second output shaft 42 to rotate in different directions, ensuring the coordination and synchronization of the transmission process.

[0040] Specifically, Figure 3-Figure 5 As shown, the first transmission assembly 31 includes a first transmission shaft 311, a first gear 312, a second transmission shaft 313, and a second gear 314. The first transmission shaft 311 and the second transmission shaft 313 are both rotatably connected to the housing 1. The first gear 312 is arranged on the first transmission shaft 311 and meshedly connected to the input gear shaft 2. When the input gear shaft 2 rotates, the first transmission shaft 311 is driven to rotate around its own axis by the first gear 312, so that the transmission of power from the input gear shaft 2 to the first transmission shaft 311 is more direct and efficient, reducing energy loss. The second gear 314 is arranged on the second transmission shaft 313 and meshedly connected to the first transmission shaft 311. The second transmission shaft 313 is configured to be connected to the second transmission assembly 32 and the third transmission assembly 33. When the first transmission shaft 311 rotates, the second transmission shaft 313 is driven to rotate around its own axis by the second gear 314, and then the power is transmitted to the subsequent second transmission assembly 32 and the third transmission assembly 33 through the second transmission shaft 313. Through the above arrangement, the power can be transmitted smoothly and synchronously.

[0041] Specifically, Figure 3 As shown, the first transmission shaft 311 and the second transmission shaft 313 are parallel to each other and spaced apart, so that the space inside the box 1 is reasonably utilized. The first transmission shaft 311, the second transmission shaft 313 and the gears thereon can operate efficiently without interfering with each other, thereby ensuring the stability and reliability of the transmission.

[0042] Specifically, Figure 3-Figure 5As shown, the second transmission assembly 32 includes a first connecting shaft 321 and a third gear 322. The first connecting shaft 321 is rotatably connected to the housing 1. The third gear 322 is disposed on the first connecting shaft 321 and meshedly connected to the second transmission shaft 313. When the second transmission shaft 313 rotates, the third gear 322 drives the first connecting shaft 321 to rotate around its own axis, thereby realizing a smooth and efficient transmission of power from the second transmission shaft 313 to the first connecting shaft 321. The first connecting shaft 321 is configured to be connected to the first output shaft 41, so that the rotation of the first connecting shaft 321 can be directly transmitted to the first output shaft 41, thereby reducing the loss in the energy transmission process and improving the transmission efficiency. Moreover, such a configuration also reduces the volume and weight of the gearbox, making the gearbox more portable, easy to install and maintain.

[0043] More specifically, the first connecting shaft 321 includes a first spline shaft 3211 and a second spline shaft 3212. The second spline shaft 3212 is key-connected to the first spline shaft 3211 and is coaxially arranged with the first spline shaft 3211. It is configured to be connected to the first output shaft 41. The rotation of the second spline shaft 3212 drives the first output shaft 41 to rotate around its own axis, thereby achieving the final output of power, thereby meeting the extrusion operation requirements. Moreover, the second spline shaft 3212 is key-connected to the first spline shaft 3211 and is coaxially arranged with the first spline shaft 3211, thereby improving the connection strength between the second spline and the first spline shaft 3211, ensuring the coaxiality of the two during the rotation process, and reducing the vibration and wear caused by the two being not in axial direction.

[0044] More specifically, in this embodiment, both ends of the first spline shaft 3211 are rotatably connected to the housing 1 through bearings, one end of the second spline shaft 3212 is connected to the first spline shaft 3211 through a spline, and the other end is rotatably connected to the housing 1 through a bearing, so that the first spline shaft 3211 and the second spline shaft 3212 can rotate freely in the housing 1 under the driving action of the second transmission shaft 313, and can withstand certain radial and axial loads. In addition, the screw is threadedly connected to the first spline shaft 3211 and the second spline shaft 3212, and is extended along the axial direction of the first spline shaft 3211 and the second spline shaft 3212, thereby fixing the relative position between the first spline shaft 3211 and the second spline shaft 3212, realizing the axial positioning of the first spline shaft 3211 and the second spline shaft 3212, and preventing them from axially moving during operation.

[0045] It should be noted that, in this embodiment, the first gear 312 is key-connected to the first transmission shaft 311, the second gear 314 is key-connected to the second transmission shaft 313, and the third gear 322 is key-connected to the first spline shaft 3211. The key connection between the above components is not only conducive to torque transmission, but also plays a role in positioning and fixing, so as to facilitate the combined assembly and stable connection between the above components.

[0046] Specifically, Figure 3-Figure 5 As shown, the third transmission assembly 33 includes a second connecting shaft 331, a fourth gear 332 and a third connecting shaft 333. The second connecting shaft 331 and the third connecting shaft 333 are both rotatably connected to the housing 1. The fourth gear 332 is disposed on the second connecting shaft 331 and meshedly connected to the second transmission shaft 313. When the second transmission shaft 313 rotates, the second connecting shaft 331 is driven to rotate around its own axis by the fourth gear 332, thereby reducing the loss in the power transmission process. The third connecting shaft 333 is meshedly connected to the second connecting shaft 331 and is configured to be connected to the second output shaft 42. When the second connecting shaft 331 rotates, the second output shaft 42 is driven to rotate around its own axis by the third connecting shaft 333, thereby achieving the final output of power.

[0047] More specifically, the second connecting shaft 331 includes a third spline shaft 3311, a fourth spline shaft 3312 and a connecting member 3313. The third spline shaft 3311 is connected to the fourth spline shaft 3312 through the connecting member 3313 and is coaxially arranged with the fourth spline shaft 3312. The fourth spline shaft 3312 is configured to be meshed and connected to the third connecting shaft 333. Through the coaxial transmission of the third spline shaft 3311, the connecting member 3313 and the fourth spline shaft 3312, the power is stably transmitted to the third connecting shaft 333, reducing the loss in the power transmission process. Among them, the connecting member 3313 of this embodiment is an inner spline sleeve, which is sleeved on the third spline shaft 3311 and the fourth spline shaft 3312, and the third spline shaft 3311 and the fourth spline shaft 3312 are closely connected through the meshing between the spline teeth. In other embodiments, the connecting member 3313 may be a screw or other component, that is, as long as the above-mentioned functions can be achieved, the specific structure of the connecting member 3313 is not limited too much here.

[0048] More specifically, in this embodiment, the fourth gear 332 is connected to the third spline shaft 3311 through interference fit, so that the two are firmly connected and the torque is transmitted reliably. The two ends of the third spline shaft 3311 are rotatably connected to the housing 1 through bearings, and the axial positioning is achieved through the pressure plate and the cover, so that the third spline shaft 3311 can rotate in the housing 1 without displacement along its own axis, and the operation is safer and more reliable.

[0049] Specifically, Figure 3-Figure 5As shown, the box body 1 is provided with an oil outlet 11, and the interior of the box body 1 is connected to the outside through the oil outlet 11. A control valve 5 is provided at the oil outlet 11. By opening or closing the control valve 5, the operator can control the flow of the lubricating oil in the box body 1 to ensure that no leakage or waste occurs when the lubricating oil is replaced.

[0050] More specifically, in this embodiment, the oil outlet 11 is arranged at the bottom of the housing 1 to facilitate the discharge of the old oil accumulated at the bottom. The control valve 5 adopts a ball valve, which has the advantages of small fluid resistance, good sealing performance, and easy operation. In other embodiments, the oil outlet 11 is opened on the side of the housing 1, and the control valve 5 adopts a gate valve or a stop valve, that is, as long as the above-mentioned functions can be achieved, the specific position of the oil outlet 11 and the specific structure of the control valve 5 are not limited too much.

[0051] It should be noted that, in the present embodiment, the first transmission shaft 311 , the second transmission shaft 313 , the first connecting shaft 321 , the second connecting shaft 331 and the third connecting shaft 333 are all rotatably connected to the housing 1 via bearings.

[0052] The specific working process of the gearbox is described below:

[0053] When the driving assembly drives the input gear shaft 2 to rotate around its own axis, the first transmission shaft 311 is driven to rotate around its own axis through the first gear 312, and then the second transmission shaft 313 is driven to rotate around its own axis through the second gear 314. When the second transmission shaft 313 rotates, the first connecting shaft 321 is driven to rotate around its own axis through the third gear 322, and the rotation of the first connecting shaft 321 drives the first output shaft 41 to rotate around its own axis, thereby reducing the loss in the energy transfer process and improving the transmission efficiency. At the same time, when the second transmission shaft 313 rotates, the second connecting shaft 331 is driven to rotate around its own axis through the fourth gear 332, and then the second output shaft 42 is driven to rotate around its own axis through the third connecting shaft 333, thereby realizing the parallel output and skew rotation of the first output shaft 41 and the second output shaft 42, and ensuring the coordination and synchronization of the transmission process.

[0054] This embodiment also provides an extrusion device, which includes a driving mechanism and a gear box, wherein the output end of the driving mechanism is connected to the input gear shaft 2, and can drive the input gear shaft 2 to rotate, thereby realizing the parallel transmission output of the first output shaft 41 and the second output shaft 42, and the rotation directions of the first output shaft 41 and the second output shaft 42 are opposite, so as to meet the requirements of parallel transmission output and skew rotation of the twin screws in the twin-screw extruder. It should be noted that the extrusion device of this embodiment includes but is not limited to devices such as twin-screw extruders and planetary extruders, and the driving mechanism includes a stepping motor or a servo motor, which can realize stable driving of the input gear shaft 2, which will not be repeated here.

[0055] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. Gear box, characterized in that, include: Box body (1); An input gear shaft (2) rotatably connected to the housing (1); Transmission assembly (3); The output assembly (4) comprises a first output shaft (41) and a second output shaft (42) which are parallel to each other and spaced apart from each other. The first output shaft (41) and the second output shaft (42) are both connected to the input gear shaft (2) through the transmission assembly (3). When the input gear shaft (2) rotates, the first output shaft (41) and the second output shaft (42) respectively rotate around their own axes, and the rotation direction of the first output shaft (41) is opposite to the rotation direction of the second output shaft (42).

2. The gearbox according to claim 1, characterized in that: The transmission assembly (3) comprises a first transmission assembly (31), a second transmission assembly (32) and a third transmission assembly (33); the first transmission assembly (31) is connected to the input gear shaft (2), and is also connected to the second transmission assembly (32) and the third transmission assembly (33); the second transmission assembly (32) is configured to be connected to the first output shaft (41), and the third transmission assembly (33) is configured to be connected to the second output shaft (42); when the input gear shaft (2) rotates, the second transmission assembly (32) and the third transmission assembly (33) are driven to rotate via the first transmission assembly (31).

3. The gearbox according to claim 2, characterized in that: The first transmission assembly (31) comprises a first transmission shaft (311), a first gear (312), a second transmission shaft (313) and a second gear (314); the first transmission shaft (311) and the second transmission shaft (313) are both rotatably connected to the housing (1); the first gear (312) is disposed on the first transmission shaft (311) and meshedly connected to the input gear shaft (2); the second gear (314) is disposed on the second transmission shaft (313) and meshedly connected to the first transmission shaft (311); the second transmission shaft (313) is configured to be connected to the second transmission assembly (32) and the third transmission assembly (33).

4. The gearbox according to claim 3, characterized in that: The first transmission shaft (311) and the second transmission shaft (313) are parallel to each other and arranged at an interval.

5. The gearbox according to claim 3, characterized in that: The second transmission assembly (32) comprises a first connecting shaft (321) and a third gear (322), wherein the first connecting shaft (321) is rotatably connected to the housing (1), the third gear (322) is disposed on the first connecting shaft (321) and meshingly connected to the second transmission shaft (313), and the first connecting shaft (321) is configured to be connected to the first output shaft (41).

6. The gearbox according to claim 5, characterized in that: The first connecting shaft (321) includes a first spline shaft (3211) and a second spline shaft (3212), wherein the second spline shaft (3212) is key-connected to the first spline shaft (3211) and is coaxially arranged with the first spline shaft (3211), and is configured to be connected to the first output shaft (41).

7. The gearbox according to claim 3, characterized in that: The third transmission assembly (33) comprises a second connecting shaft (331), a fourth gear (332) and a third connecting shaft (333); the second connecting shaft (331) and the third connecting shaft (333) are both rotatably connected to the housing (1); the fourth gear (332) is disposed on the second connecting shaft (331) and meshedly connected to the second transmission shaft (313); the third connecting shaft (333) is meshedly connected to the second connecting shaft (331) and is configured to be connected to the second output shaft (42).

8. The gearbox according to claim 7, characterized in that: The second connecting shaft (331) includes a third spline shaft (3311), a fourth spline shaft (3312) and a connecting member (3313), wherein the third spline shaft (3311) is connected to the fourth spline shaft (3312) via the connecting member (3313) and is coaxially arranged with the fourth spline shaft (3312), and the fourth spline shaft (3312) is configured to be meshedly connected to the third connecting shaft (333).

9. The gearbox according to any one of claims 1 to 8, characterized in that: The box body (1) is provided with an oil outlet (11), the interior of the box body (1) is connected to the outside through the oil outlet (11), and a control valve (5) is provided at the oil outlet (11).

10. Extrusion device, characterized in that It comprises a driving mechanism and a gear box as claimed in any one of claims 1 to 9, wherein the output end of the driving mechanism is connected to the input gear shaft (2) and can drive the input gear shaft (2) to rotate.

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