Transmission powertrain, its control methods and engineering machinery

Abstract

This invention relates to the field of engineering machinery technology, and particularly to a gearbox powertrain, its control method, and engineering machinery. The gearbox powertrain includes a motor, a main gearbox, and a secondary gearbox. The main gearbox includes a first planetary gear set, a second planetary gear set, and a first gear shifting mechanism. The secondary gearbox includes a third planetary gear set and a second gear shifting mechanism. This invention employs a main gearbox plus a secondary gearbox configuration, enabling 3*2 gear shifting, i.e., six-speed shifting. Furthermore, during gear shifting, the secondary gearbox can be first fixed to a certain gear according to the working conditions, and then the main gearbox can be shifted to the corresponding gear, better adapting to different working conditions. Additionally, both the main and secondary gearboxes are planetary gearboxes, featuring a novel combination, simple manufacturing, and controllable quality.

Description

Technical Field

[0001] This invention relates to the field of engineering machinery technology, and in particular to a gearbox powertrain, its control method, and engineering machinery. Background Technology

[0002] In recent years, electric heavy-duty trucks have developed rapidly in mining operations. Their powertrains consist of batteries, motors, and low-speed gearboxes, offering advantages such as energy efficiency, environmental friendliness, powerful performance, and ease of operation. Compared to traditional powertrains composed of engines and multi-speed gearboxes, they possess unparalleled advantages. Electric heavy-duty trucks mainly include dump trucks and concrete mixer trucks, used for transporting building materials in urban and suburban roads. Currently, most mainstream electric heavy-duty trucks on the market use a single motor as the power source, which drives the gearbox. The gearbox switches gears via sliding sleeves to meet different operating conditions. Existing electric heavy-duty truck gearboxes are mostly fixed-shaft type. Due to the relatively large torque transmitted, the gearboxes are generally designed with two or three intermediate parallel shafts. Adding or removing gears is achieved by increasing or decreasing the number of meshing gears on the parallel shafts. If there are too few gears, the requirements of various heavy-duty truck operating conditions cannot be met; if there are too many gears, the design and manufacturing precision become complex, and quality control becomes difficult. This technical solution presents a significant contradiction between the adaptability to different operating conditions and manufacturing costs and quality. Summary of the Invention

[0003] The purpose of this invention is to provide a gearbox powertrain, its control method, and engineering machinery that can better adapt to different working conditions and has a novel structural form.

[0004] To achieve this objective, the present invention adopts the following technical solution:

[0005] A transmission powertrain, comprising:

[0006] The motor has a first input shaft connected to its output end;

[0007] The main gearbox includes a first planetary gear set, a second planetary gear set, and a first gear shifting mechanism. The first planetary gear set includes a first sun gear, first planet gears, a first planet carrier, and a first ring gear. The second planetary gear set includes a second sun gear, second planet gears, a second planet carrier, and a second ring gear. The first and second planetary gear sets are connected in series along the axial direction of the first input shaft. Both the first and second sun gears are fixedly mounted on the first input shaft, and power is output to the second input shaft via the first planet carrier or the first ring gear. The first gear shifting mechanism is used to switch the power transmission path from the first input shaft to the second input shaft.

[0008] The auxiliary gearbox includes a third planetary gear set and a second gear shifting mechanism. The third planetary gear set includes a third sun gear, a third planet gear, a third planet carrier, and a third ring gear. The third sun gear is fixed on the second input shaft, and power is output to the output shaft by the third planet carrier or the third ring gear. The second gear shifting mechanism is used to switch the power transmission path from the second input shaft to the output shaft.

[0009] As a preferred technical solution for the powertrain, the first planetary gear set and the second planetary gear set are connected in series such that the first ring gear is fixedly connected to the second planetary carrier, and the first planetary carrier outputs power to the second input shaft.

[0010] As a preferred technical solution for the powertrain of the transmission, the first planetary gear set and the second planetary gear set are connected in series such that the first planetary carrier is fixedly connected to the second ring gear, and the first ring gear outputs power to the second input shaft.

[0011] As a preferred technical solution for the transmission powertrain, the first gear shifting mechanism includes a gear a and a sliding sleeve a. The gear a includes a zero gear a, a first gear a, a second gear a, and a third gear a. The zero gear a is fixedly mounted on the transmission housing. The first gear a is fixedly connected to the second planetary carrier. The second gear a is fixedly connected to the second gear ring. The third gear a is fixedly mounted on the first input shaft. The sliding sleeve a can control the engagement and disengagement of the zero gear a and the first gear a, the engagement and disengagement of the zero gear a and the second gear a, and the engagement and disengagement of the first gear a and the third gear a.

[0012] As a preferred technical solution for the transmission powertrain, the first gear shifting mechanism includes a gear a and a sliding sleeve a. The gear a includes a zero gear a, a first gear a, a second gear a, and a third gear a. The zero gear a is fixedly mounted on the transmission housing. The first gear a is fixedly connected to the second gear ring. The second gear a is fixedly connected to the second planetary carrier. The third gear a is fixedly mounted on the first input shaft. The sliding sleeve a can control the engagement and disengagement of the zero gear a and the first gear a, the engagement and disengagement of the zero gear a and the second gear a, and the engagement and disengagement of the first gear a and the third gear a.

[0013] As a preferred technical solution for the powertrain, the zero gear a is a double-row gear, including two sub-zero gears a, one of which is located on the same side as the second gear a, and the other is located on the same side as the first gear a and the third gear a.

[0014] The sliding sleeve a includes a first sliding sleeve a and a second sliding sleeve a. The first sliding sleeve a can control the engagement and disengagement of one of the sub-zero gears a with the second gear a. The second sliding sleeve a can control the engagement and disengagement of the other sub-zero gear a with the first gear a, as well as the engagement and disengagement of the first gear a with the third gear a.

[0015] As a preferred technical solution for the transmission powertrain, the second gear shifting mechanism includes a gear b and a sliding sleeve b. The gear b includes a zero gear b, a first gear b, and a second gear b. The first gear b is fixedly connected to the transmission housing, and the second gear b is fixedly connected to the second input shaft.

[0016] When power is output from the third planetary carrier to the output shaft, the zero gear b is fixedly connected to the third ring gear. When power is output from the third ring gear to the output shaft, the zero gear b is fixedly connected to the third planetary carrier.

[0017] As a preferred technical solution for the transmission powertrain, the first input shaft, the second input shaft, and the output shaft are coaxially arranged.

[0018] A control method for a transmission powertrain, applied to the transmission powertrain described in any of the above schemes, wherein during gear shifting, the auxiliary transmission is first controlled to be fixed in one gear according to the working conditions, and then the main transmission is controlled to switch gears sequentially from low to high.

[0019] As a preferred technical solution for the control method of the transmission powertrain,

[0020] When the working condition is heavy load, first control the auxiliary gearbox to switch to first gear, and then control the main gearbox to switch to first gear, second gear and third gear in sequence, so as to form the low speed first gear, low speed second gear and low speed third gear of the gearbox powertrain.

[0021] When the operating condition is light load, the auxiliary gearbox is first controlled to switch to second gear, and then the main gearbox is controlled to switch to first gear, second gear and third gear in sequence, thus forming the high-speed first gear, high-speed second gear and high-speed third gear of the gearbox powertrain.

[0022] As a preferred technical solution for the control method of the transmission powertrain, controlling the auxiliary transmission to switch to first gear specifically involves controlling the sliding sleeve b to engage the zero gear b with the first gear b;

[0023] The process of controlling the auxiliary gearbox to switch to second gear involves controlling the sliding sleeve b to disconnect the zero gear b from the first gear b, and then returning the sliding sleeve b to the neutral position of the zero gear b. The speed of the motor is then adjusted so that the speed of the second gear b is the same as the speed of the zero gear b. Finally, the sliding sleeve b is controlled to engage the zero gear b with the second gear b.

[0024] As a preferred technical solution for the control method of the transmission powertrain, controlling the main transmission to switch to first gear specifically involves controlling the second sliding sleeve a to engage the zero gear a and the first gear a.

[0025] The specific steps for controlling the main gearbox to switch to second gear are as follows: control the second sliding sleeve a to disconnect the zero gear a from the first gear a, and return the second sliding sleeve a to the neutral position of the first gear a. Then adjust the speed of the motor so that the speed of the second gear a is the same as the speed of the zero gear a. After that, control the first sliding sleeve a to engage the second gear a with the zero gear a.

[0026] The specific steps for controlling the main gearbox to switch to third gear are as follows: control the first sliding sleeve a to disconnect the zero gear a from the second gear a, and return the first sliding sleeve a to the neutral position of the second gear a. Then adjust the speed of the motor so that the speed of the third gear a is the same as the speed of the first gear a. After that, control the second sliding sleeve a to engage the third gear a with the first gear a.

[0027] An engineering machine includes a gearbox powertrain as described in any of the above embodiments or a control method using a gearbox powertrain as described in any of the above embodiments.

[0028] The beneficial effects of this invention are:

[0029] The powertrain provided by this invention adopts a main gearbox plus an auxiliary gearbox, which can achieve 3*2 gear switching, that is, six-speed switching. When switching gears, the auxiliary gearbox can be fixed to a gear first according to the working conditions, and then the main gearbox can be switched to the corresponding gear, which can better adapt to different working conditions. In addition, both the main gearbox and the auxiliary gearbox adopt planetary gearboxes, which is novel in combination, simple to manufacture, and has controllable quality. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the transmission powertrain provided in an embodiment of the present invention. Figure 1 ;

[0031] Figure 2 This is a schematic diagram of the transmission powertrain provided in an embodiment of the present invention. Figure 2 ;

[0032] Figure 3 This is a schematic diagram of the transmission powertrain provided in an embodiment of the present invention. Figure 3 ;

[0033] Figure 4 This is a schematic diagram of the transmission powertrain provided in an embodiment of the present invention. Figure 4 .

[0034] In the picture:

[0035] 10. Electric motor;

[0036] 21. First input axis; 22. Second input axis; 23. Output axis;

[0037] 31. First planetary gear set; 311. First sun gear; 312. First planetary gear; 313. First planetary carrier; 314. First ring gear; 32. Second planetary gear set; 321. Second sun gear; 322. Second planetary gear; 323. Second planetary carrier; 324. Second ring gear; 33. Gear a; 331. Zero gear a; 332. First gear a; 333. Second gear a; 334. Third gear a; 34. Sliding sleeve a; 341. First sliding sleeve a; 342. Second sliding sleeve a;

[0038] 41. Third planetary gear set; 411. Third sun gear; 412. Third planetary gear set; 413. Third planetary carrier; 414. Third ring gear; 42. Gear b; 421. Zero gear b; 422. First gear b; 423. Second gear b; 43. Sliding sleeve b. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0040] Therefore, 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 to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0041] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0042] In the description of this invention, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0043] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0044] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0045] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0046] like Figures 1 to 4 As shown, an embodiment of the present invention provides a gearbox powertrain, including a motor 10, a main gearbox and a secondary gearbox, wherein the output end of the motor 10 is connected to a first input shaft 21.

[0047] The main gearbox includes a first planetary gear set 31, a second planetary gear set 32, and a first gear shifting mechanism. The first planetary gear set 31 includes a first sun gear 311, a first planet gear 312, a first planet carrier 313, and a first ring gear 314. The second planetary gear set 32 ​​includes a second sun gear 321, a second planet gear 322, a second planet carrier 323, and a second ring gear 324. The first planetary gear set 31 and the second planetary gear set 32 ​​are connected in series along the axial direction of the first input shaft 21. The first sun gear 311 and the second sun gear 321 are both fixedly sleeved on the first input shaft 21, and power is output to the second input shaft 22 by the first planet carrier 313 or the first ring gear 314. The first gear shifting mechanism is used to switch the power transmission path from the first input shaft 21 to the second input shaft 22.

[0048] The first gear shifting mechanism includes a gear a33 and a sliding sleeve a34. The gear a33 includes a zero gear a331, a first gear a332, a second gear a333, and a third gear a334.

[0049] There are two ways to connect the first planetary row 31 and the second planetary row 32, see reference. Figure 1 and Figure 2 In the first series connection method, the first gear ring 314 is fixedly connected to the second planetary carrier 323, and the power is output from the first planetary carrier 313 to the second input shaft 22. In this series connection method, the zero gear a331 is fixedly mounted on the gearbox housing, the first gear a332 is fixedly connected to the second planetary carrier 323, the second gear a333 is fixedly connected to the second gear ring 324, and the third gear a334 is fixedly mounted on the first input shaft 21.

[0050] Reference Figure 3 and Figure 4 The second series connection method involves a fixed connection between the first planetary carrier 313 and the second ring gear 324, with power output from the first ring gear 314 to the second input shaft 22. In this series connection method, the zero gear a331 is fixedly mounted on the gearbox housing, the first gear a332 is fixedly connected to the second ring gear 324, the second gear a333 is fixedly connected to the second planetary carrier 323, and the third gear a334 is fixedly mounted on the first input shaft 21.

[0051] The difference between the first planetary gear set 31 and the second planetary gear set 32 ​​in series lies in their output transmission ratios. The first series gear set has a higher output transmission ratio than the second series gear set. The specific choice can be made according to the needs.

[0052] The sliding sleeve a34 controls the engagement and disengagement of the zero gear a331 with the first gear a332, the engagement and disengagement of the zero gear a331 with the second gear a333, and the engagement and disengagement of the first gear a332 with the third gear a334. In this embodiment, the zero gear a331 is a double-row gear, including two sub-zero gears a. One sub-zero gear a is located on the same side as the second gear a333, and the other sub-zero gear a is located on the same side as the first gear a332 and the third gear a334. The sliding sleeve a34 includes a first sliding sleeve a341 and a second sliding sleeve a342. The first sliding sleeve a341 controls the engagement and disengagement of one sub-zero gear a with the second gear a333, and the second sliding sleeve a342 controls the engagement and disengagement of the other sub-zero gear a with the first gear a332, as well as the engagement and disengagement of the first gear a332 with the third gear a334.

[0053] When it is necessary to shift the main gearbox to first gear, the second sliding sleeve a342 engages with the zero gear a331 and the first gear a332. (Refer to...) Figure 1 and Figure 2 When the first planetary gear set 31 and the second planetary gear set 32 ​​are connected in the first series configuration, the power transmission route of the main gearbox in first gear is as follows: the power from the motor 10 is transmitted to the second input shaft 22 via the first sun gear 311, the first planetary gear 312, and the first planetary carrier 313. (Refer to...) Figure 3 and Figure 4 When the first planetary gear set 31 and the second planetary gear set 32 ​​adopt the second series connection method, the power transmission route of the main gearbox in the first gear state is as follows: the power of the motor 10 is transmitted to the second input shaft 22 through the first sun gear 311, the first planetary gear 312 and the first ring gear 314.

[0054] When the main gearbox needs to be shifted to second gear, the second sliding sleeve a342 is controlled to disengage the zero gear a331 from the first gear a332, and then returns the second sliding sleeve a342 to the neutral position of the first gear a332. Then, the speed of the motor 10 is adjusted so that the speed of the second gear a333 is the same as the speed of the zero gear a331. Afterwards, the first sliding sleeve a341 is controlled to engage the second gear a333 with the zero gear a331. (Refer to...) Figure 1 and Figure 2 When the first planetary gear set 31 and the second planetary gear set 32 ​​are connected in the first series configuration, the power transmission route of the main gearbox in second gear is as follows: the power from the motor 10 is transmitted to the second input shaft 22 via the second sun gear 321, the second planetary gear 322, the second planetary carrier 323, the first ring gear 314, the first planetary gear 312, and the first planetary carrier 313. (Refer to...) Figure 3 and Figure 4When the first planetary gear set 31 and the second planetary gear set 32 ​​adopt the second series connection method, the power transmission route of the main gearbox in the second gear state is as follows: the power of the motor 10 is transmitted to the second input shaft 22 via the second sun gear 321, the second planetary gear 322, the second ring gear 324, the first planetary carrier 313, the first planetary gear 312 and the first ring gear 314.

[0055] When the main gearbox needs to be switched to third gear, the first sliding sleeve a341 is controlled to disengage the zero gear a331 from the second gear a333, and then returns the first sliding sleeve a341 to its neutral position in the second gear a333. The speed of the motor 10 is then adjusted so that the speed of the third gear a334 is the same as the speed of the first gear a332. Finally, the second sliding sleeve a342 is controlled to engage the third gear a334 with the first gear a332. (Refer to...) Figure 1 and Figure 2 When the first planetary gear set 31 and the second planetary gear set 32 ​​are connected in series, the power transmission route of the main gearbox in third gear is as follows: the power of the motor 10 is directly transmitted to the second input shaft 22. (Refer to...) Figure 3 and Figure 4 When the first planetary gear set 31 and the second planetary gear set 32 ​​adopt the second series connection method, the power transmission route of the main gearbox in the third gear state is also the same: the power of the motor 10 is directly transmitted to the second input shaft 22.

[0056] The auxiliary gearbox includes a third planetary gear set 41 and a second gear shifting mechanism. The third planetary gear set 41 includes a third sun gear 411, a third planetary gear 412, a third planetary carrier 413, and a third ring gear 414. The third sun gear 411 is fixed on the second input shaft 22, and power is output to the output shaft 23 by the third planetary carrier 413 or the third ring gear 414. The second gear shifting mechanism is used to switch the power transmission path from the second input shaft 22 to the output shaft 23.

[0057] The second gear shifting mechanism includes a gear b42 and a sliding sleeve b43. The gear b42 includes a zero gear b421, a first gear b422, and a second gear b423. The first gear b422 is fixedly connected to the gearbox housing, and the second gear b423 is fixedly connected to the second input shaft 22. The connection method of the zero gear b421 will differ depending on the power output method of the third planetary gear set 41. (Refer to...) Figure 2 and Figure 4 When power is output from the third planetary carrier 413 to the output shaft 23, the zero gear b421 is fixedly connected to the third gear ring 414; refer to Figure 1 and Figure 3When power is output from the third ring gear 414 to the output shaft 23, the zero gear b421 is fixedly connected to the third planetary carrier 413. The difference between these two methods lies in the output transmission ratio. The transmission ratio of power output from the third planetary carrier 413 is greater than that of power output from the third ring gear 414. The specific ratio can be selected according to the needs.

[0058] When the auxiliary gearbox needs to be shifted to first gear, the control sleeve b43 engages the zero gear gear b421 with the first gear gear b422. (Refer to...) Figure 2 and Figure 4 When the third planetary gear set 41 outputs power from the third planetary carrier 413, the power transmission route of the auxiliary gearbox in first gear is as follows: the power received by the second input shaft 22 is transmitted to the output shaft 23 via the third sun gear 411, the third planetary gear 412, and the third planetary carrier 413. (Refer to...) Figure 1 and Figure 3 When the third planetary gear set 41 outputs power through the third ring gear 414, the power transmission route of the auxiliary gearbox in first gear is as follows: the power received by the second input shaft 22 is transmitted to the output shaft 23 via the third sun gear 411, the third planetary gear 412, and the third ring gear 414.

[0059] When the auxiliary gearbox needs to be shifted to second gear, the control sleeve b43 disengages the zero gear b421 from the first gear b422 and returns the sleeve b43 to the neutral position of the zero gear b421. Then, the speed of the motor 10 is adjusted so that the speed of the second gear b423 is the same as the speed of the zero gear b421. Afterward, the control sleeve b43 engages the zero gear b421 with the second gear b423. (Refer to...) Figure 2 and Figure 4 When the third planetary gear set 41 outputs power from the third planetary carrier 413, the power transmission route of the auxiliary gearbox in second gear is as follows: the power received by the second input shaft 22 is directly transmitted to the output shaft 23. (Refer to...) Figure 1 and Figure 3 When the third planetary gear set 41 outputs power through the third ring gear 414, the power transmission route of the auxiliary gearbox in second gear is also as follows: the power received by the second input shaft 22 is directly transmitted to the output shaft 23.

[0060] In this embodiment, the first input shaft 21, the second input shaft 22, and the output shaft 23 are coaxially arranged.

[0061] This invention also provides a control method for a transmission powertrain. When shifting gears, based on the operating conditions, the auxiliary transmission is first controlled to be fixed in one gear, and then the main transmission is controlled to switch gears sequentially from low to high.

[0062] Specifically, when the operating condition is heavy load, the auxiliary gearbox is first controlled to switch to first gear, and then the main gearbox is controlled to switch to first, second and third gear in sequence, thus forming the low-speed first gear, low-speed second gear and low-speed third gear of the gearbox powertrain; when the operating condition is light load, the auxiliary gearbox is first controlled to switch to second gear, and then the main gearbox is controlled to switch to first, second and third gear in sequence, thus forming the high-speed first gear, high-speed second gear and high-speed third gear of the gearbox powertrain.

[0063] The powertrain provided in this invention adopts a main gearbox plus an auxiliary gearbox, which can achieve 3*2 gear switching, that is, six-speed switching. When switching gears, the auxiliary gearbox can be fixed to a gear first according to the working conditions, and then the main gearbox can be switched to the corresponding gear, which can better adapt to different working conditions. In addition, both the main gearbox and the auxiliary gearbox adopt planetary gearboxes, which is novel in combination, simple to manufacture, and has controllable quality.

[0064] This invention also provides a type of construction machinery, including the gearbox powertrain described above or a control method using the gearbox powertrain described above. In this embodiment, the construction machinery is preferably an electric heavy-duty truck, but it is not limited thereto.

[0065] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A transmission powertrain, characterized in that, include: The motor (10) has a first input shaft (21) connected to its output end; The main gearbox includes a first planetary gear set (31), a second planetary gear set (32), and a first gear shifting mechanism. The first planetary gear set (31) includes a first sun gear (311), a first planetary gear (312), a first planet carrier (313), and a first ring gear (314). The second planetary gear set (32) includes a second sun gear (321), a second planetary gear (322), a second planet carrier (323), and a second ring gear (324). The first planetary gear set (31) and the second planetary gear set (32) are connected in series along the axial direction of the first input shaft (21), and the first sun gear (311) and the second sun gear (321) are both fixedly sleeved on the first input shaft (21), and power is output to the second input shaft (22) by the first planet carrier (313) or the first ring gear (314). The first gear shifting mechanism is used to switch the power transmission path from the first input shaft (21) to the second input shaft (22). The auxiliary gearbox includes a third planetary gear set (41) and a second gear shifting mechanism. The third planetary gear set (41) includes a third sun gear (411), a third planetary gear (412), a third planetary carrier (413), and a third ring gear (414). The third sun gear (411) is fixed on the second input shaft (22), and power is output to the output shaft (23) by the third planetary carrier (413) or the third ring gear (414). The second gear shifting mechanism is used to switch the power transmission path from the second input shaft (22) to the output shaft (23). The first planetary gear set (31) and the second planetary gear set (32) are connected in series such that the first gear ring (314) is fixedly connected to the second planetary carrier (323), and the first planetary carrier (313) outputs power to the second input shaft (22); The first gear shifting mechanism includes a gear a (33) and a sliding sleeve a (34). The gear a (33) includes a zero gear a (331), a first gear a (332), a second gear a (333), and a third gear a (334). The zero gear a (331) is fixedly mounted on the gearbox housing. The first gear a (332) is fixedly connected to the second planetary carrier (323). The second gear a (333) is fixedly connected to the second gear ring (324). The third gear a (334) is fixedly mounted on the first input shaft (21). The sliding sleeve a (34) can control the engagement and disengagement of the zero gear a (331) and the first gear a (332), the engagement and disengagement of the zero gear a (331) and the second gear a (333), and the engagement and disengagement of the first gear a (332) and the third gear a (334).

2. The gearbox powertrain according to claim 1, characterized in that, The first planetary gear set (31) and the second planetary gear set (32) are connected in series such that the first planetary carrier (313) is fixedly connected to the second gear ring (324), and the first gear ring (314) outputs power to the second input shaft (22).

3. The gearbox powertrain according to claim 2, characterized in that, The first gear shifting mechanism includes a gear a (33) and a sliding sleeve a (34). The gear a (33) includes a zero gear a (331), a first gear a (332), a second gear a (333), and a third gear a (334). The zero gear a (331) is fixedly mounted on the gearbox housing. The first gear a (332) is fixedly connected to the second gear ring (324). The second gear a (333) is fixedly connected to the second planetary carrier (323). The third gear a (334) is fixedly mounted on the first input shaft (21). The sliding sleeve a (34) can control the engagement and disengagement of the zero gear a (331) and the first gear a (332), the engagement and disengagement of the zero gear a (331) and the second gear a (333), and the engagement and disengagement of the first gear a (332) and the third gear a (334).

4. The gearbox powertrain according to claim 1 or 3, characterized in that, The zero gear a (331) is a double-row gear, including two sub-zero gears a, one of which is located on the same side as the second gear a (333), and the other is located on the same side as the first gear a (332) and the third gear a (334); The sliding sleeve a (34) includes a first sliding sleeve a (341) and a second sliding sleeve a (342). The first sliding sleeve a (341) can control the engagement and disengagement of one of the sub-zero gears a with the second gear a (333). The second sliding sleeve a (342) can control the engagement and disengagement of the other sub-zero gear a with the first gear a (332), as well as the engagement and disengagement of the first gear a (332) with the third gear a (334).

5. The gearbox powertrain according to claim 1, characterized in that, The second gear shifting mechanism includes a gear b (42) and a sliding sleeve b (43). The gear b (42) includes a zero gear b (421), a first gear b (422), and a second gear b (423). The first gear b (422) is fixedly connected to the gearbox housing, and the second gear b (423) is fixedly connected to the second input shaft (22). When power is output from the third planetary carrier (413) to the output shaft (23), the zero gear b (421) is fixedly connected to the third gear ring (414). When power is output from the third gear ring (414) to the output shaft (23), the zero gear b (421) is fixedly connected to the third planetary carrier (413).

6. The gearbox powertrain according to claim 1, characterized in that, The first input shaft (21), the second input shaft (22), and the output shaft (23) are coaxially arranged.

7. A control method for a transmission powertrain, characterized in that, Applied to the powertrain of the transmission as described in any one of claims 1-6, when shifting gears, depending on the operating conditions, the auxiliary transmission is first controlled to be fixed in one gear, and then the main transmission is controlled to switch gears sequentially from low to high.

8. The control method for the gearbox powertrain according to claim 7, characterized in that, When the working condition is heavy load, first control the auxiliary gearbox to switch to first gear, and then control the main gearbox to switch to first gear, second gear and third gear in sequence, so as to form the low speed first gear, low speed second gear and low speed third gear of the gearbox powertrain. When the operating condition is light load, the auxiliary gearbox is first controlled to switch to second gear, and then the main gearbox is controlled to switch to first gear, second gear and third gear in sequence, thus forming the high-speed first gear, high-speed second gear and high-speed third gear of the gearbox powertrain.

9. The control method for the gearbox powertrain according to claim 8, characterized in that, The control of the auxiliary gearbox to switch to first gear is specifically to control the sliding sleeve b (43) to engage the zero gear gear b (421) with the first gear gear b (422); The control of the auxiliary gearbox to switch to second gear is as follows: control the sliding sleeve b (43) to disconnect the zero gear b (421) from the first gear b (422), and return the sliding sleeve b (43) to the neutral position of the zero gear b (421). Then adjust the speed of the motor (10) so that the speed of the second gear b (423) is the same as the speed of the zero gear b (421). After that, control the sliding sleeve b (43) to engage the zero gear b (421) and the second gear b (423).

10. The control method for the gearbox powertrain according to claim 8, characterized in that, The control of the main gearbox to switch to first gear is specifically: controlling the second sliding sleeve a (342) to engage the zero gear a (331) and the first gear a (332); The specific steps for controlling the main gearbox to switch to second gear are as follows: control the second sliding sleeve a (342) to disconnect the zero gear a (331) from the first gear a (332), and return the second sliding sleeve a (342) to the neutral position of the first gear a (332). Then adjust the speed of the motor (10) so that the speed of the second gear a (333) is the same as the speed of the zero gear a (331). After that, control the first sliding sleeve a (341) to engage the second gear a (333) with the zero gear a (331). The control of the main gearbox to switch to third gear is as follows: control the first sliding sleeve a (341) to disconnect the zero gear a (331) from the second gear a (333), and return the first sliding sleeve a (341) to the neutral position of the second gear a (333). Then adjust the speed of the motor (10) so that the speed of the third gear a (334) is the same as the speed of the first gear a (332). Then control the second sliding sleeve a (342) to engage the third gear a (334) with the first gear a (332).

11. An engineering machinery, characterized in that, Includes the transmission powertrain according to any one of claims 1-6 or the control method of the transmission powertrain according to any one of claims 7-10.

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