ECVT variable speed power system

Abstract

The invention provides an ECVT variable speed power system which comprises an engine, a generator, a power battery pack, a motor and a drive axle assembly, the generator is electrically connected with the power battery pack, and the power battery pack is electrically connected with the motor; a first shaft is arranged at the output end of the engine, the first shaft is in transmission connection with an input shaft of the generator, and an intervention clutch is arranged on the first shaft. A second shaft is arranged at the output end of the motor, a planet wheel mechanism is arranged on the second shaft, a sun wheel of the planet wheel mechanism is in transmission connection with the second shaft, a gear ring is in transmission connection with the driven end of the intervention clutch, and a planet carrier is in transmission connection with an input shaft of the drive axle assembly. According to the invention, the planet wheel mechanism is driven by the motor, so that stepless speed change is realized; meanwhile, switching of multiple modes of a pure electric mode, a series mode and a hybrid mode can be supported, it is guaranteed that the engine operates in an economic interval, the energy efficiency is improved, oil consumption is reduced, and the use cost is low.

Description

Technical Field

[0001] This invention relates to the field of agricultural machinery travel transmission mechanism technology, specifically to an ECVT transmission power system. Background Technology

[0002] Agriculture is a foundational industry for many sectors, and tractors are indispensable agricultural machinery. In recent years, with the development of science and technology and the innovation of agricultural machinery technology, the tractor industry has developed rapidly. At the same time, with increasingly stringent environmental protection requirements, the energy consumption and environmental pollution caused by traditional tractors have become significant issues. People are also placing higher demands on the energy efficiency, emissions, and driving comfort of tractors. Therefore, research on new energy tractors is of great importance.

[0003] Most existing tractor continuously variable transmissions (CVTs) use mechanical-hydraulic split transmissions. The hydraulic system in these transmissions has relatively low efficiency, high energy loss, complex maintenance, high oil requirements, and high operating costs. Summary of the Invention

[0004] To solve at least one of the above technical problems, the present invention provides an ECVT transmission power system.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: This invention provides an ECVT transmission power system, including an engine, a generator, a power battery pack, an electric motor, and a drive axle assembly, wherein the generator is electrically connected to the power battery pack, and the power battery pack is electrically connected to the electric motor; The engine output end is provided with a shaft, which is connected to the input shaft of the generator, and the shaft is provided with an engagement clutch. The output end of the electric motor is provided with two shafts, and a planetary gear mechanism is provided on the two shafts. The sun gear of the planetary gear mechanism is driven to the two shafts, the ring gear of the planetary gear mechanism is driven to the driven end of the engagement clutch, and the planet carrier of the planetary gear mechanism is driven to the input shaft of the drive axle assembly.

[0006] The beneficial effects of this invention are: This invention utilizes an electric motor to drive the sun gear of a planetary gear mechanism, creating a speed difference between the sun gear and the ring gear, which is then transmitted to the planet carrier for power output. The output speed can be controlled by adjusting the electric motor's speed, achieving pure electric mode power output and continuously variable transmission (CVT). Furthermore, when the engine starts, it can drive a generator to supply power to the battery pack, achieving series mode power output. Simultaneously, the engine can engage the ring gear of the planetary gear mechanism via a clutch, thus cooperating with the electric motor to achieve hybrid mode power output. Therefore, this invention supports multiple mode switching, ensuring the engine operates within its economical range, improving energy efficiency, reducing fuel consumption, and lowering operating costs.

[0007] Based on the above technical solution, the present invention can be further improved as follows.

[0008] Furthermore, it also includes a brake clutch, one end of which is connected to the gear ring of the planetary gear mechanism and can constrain or release the gear ring.

[0009] It allows for easy switching between the fixed and free states of the gear ring in the planetary gear mechanism, making control convenient and operation simple.

[0010] Furthermore, the back of the gear ring of the planetary gear mechanism is also provided with a shaft sleeve, which is rotatably sleeved on the two shafts.

[0011] It facilitates stable installation of the planetary gear mechanism and reduces vibration of the gear ring.

[0012] Furthermore, a driven gear is fixedly sleeved on the shaft, and a driving gear is fixedly sleeved on the driven end of the engagement clutch, with the driving gear meshing with the driven gear.

[0013] It facilitates the transmission between the gear ring of the planetary gear mechanism and the driven end of the engagement clutch, resulting in high transmission efficiency and good reliability.

[0014] Furthermore, it also includes a control unit, wherein the engine, engagement clutch, power battery pack, electric motor, and brake clutch are respectively connected to the control unit via signals; The control unit is used to detect the state of charge (SOC) value of the power battery pack and, based on the SOC value, control the engagement and disengagement of the engagement clutch and braking clutch, as well as the start-up, shutdown, and speed of the engine and electric motor.

[0015] It facilitates automatic mode switching, is easy to operate, and has a fast response speed.

[0016] Preferably, the control unit controls the engagement and disengagement states of the engagement clutch and braking clutch based on the state of charge value, and controls the start / stop and speed of the engine and electric motor, specifically including: Obtain the input required vehicle speed and preset charge value, and monitor the state of charge (SOC) value of the power battery pack; perform the following operations based on the SOC value: When the state of charge value is not less than the preset state of charge value, switch to pure electric mode: control the engagement clutch to disengage, control the braking clutch to engage; control the engine to stop, and control the electric motor to rotate according to the required vehicle speed; When the state of charge value is less than the preset state of charge value, switch to series mode: control the disengagement of the intervention clutch, control the engagement of the braking clutch; control the engine to start, and control the electric motor to rotate according to the required vehicle speed; In series mode, the input engine economic speed range and economic torque range are obtained, and the actual engine speed and actual torque are monitored; when the actual speed is within the economic speed range and the actual torque is within the economic torque range, the series mode is maintained. When the actual engine speed exceeds the economic speed range, or the actual torque exceeds the economic torque range, the system switches to hybrid mode: the clutch engages and the braking clutch disengages; simultaneously, the engine speed and electric motor speed are controlled according to the planetary gear set formula, as follows: N D +kN F =(1+k)Nx; Where, N D N is the speed of the electric motor. F Nx is the engine speed, Nx is the output speed of the planetary carrier, and K is the gear ratio between the ring gear and the sun gear.

[0017] Furthermore, a driven gear is fixedly mounted on the input shaft of the generator, and a driving gear is fixedly mounted on the shaft, with the driven gear meshing with the driving gear.

[0018] It facilitates transmission between the shaft and the generator's input shaft, resulting in high transmission efficiency and good reliability.

[0019] Furthermore, it also includes a PTO assembly, whose input shaft is connected to a single-shaft drive.

[0020] When the engine starts, it can drive the PTO assembly to work, which is convenient for providing power to external tools and equipment; the engine power is constant, and the PTO assembly has good working stability.

[0021] Furthermore, it also includes a PTO clutch, the driving end of which is connected to a shaft drive, and the driven end of which is connected to the input shaft drive of the PTO assembly.

[0022] It facilitates the control of the power supply to and from the PTO assembly, thus avoiding power waste.

[0023] Furthermore, it also includes a hydraulic pump, the input shaft of which is connected to a shaft drive.

[0024] When the engine starts, it can drive the hydraulic pump to work, which facilitates the provision of power to the external hydraulic system and improves the energy utilization efficiency of the engine.

[0025] Furthermore, a hydraulic driven wheel is fixedly sleeved on the input shaft of the hydraulic pump, and a hydraulic driving wheel is fixedly sleeved on the shaft, with the hydraulic driving wheel meshing with the hydraulic driven wheel.

[0026] It facilitates the transmission between the input shaft and the primary shaft of the hydraulic pump, resulting in high transmission efficiency and good reliability. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the present invention.

[0028] Figure 2 This is a schematic diagram of power transmission in the pure electric mode of the present invention.

[0029] Figure 3 This is a schematic diagram of power transmission in the series mode of the present invention.

[0030] Figure 4 This is a schematic diagram of power transmission in the hybrid mode of the present invention.

[0031] In the accompanying drawings, the technical features represented by each reference numeral are as follows: 1-Engine; 2-First shaft; 3-Engine clutch; 4-Generator; 5-Power battery pack; 6-Electric motor; 7-Second shaft; 8-Ring gear; 9-Sun gear; 10-Planetary carrier; 11-Drive axle assembly; 12-Brake clutch; 13-Shaft sleeve; 14-Engine driven gear; 15-Engine drive gear; 16-Generator driven gear; 17-Generator drive gear; 18-PTO assembly; 19-PTO clutch; 20-Hydraulic pump; 21-Hydraulic driven wheel; 22-Hydraulic drive wheel. Detailed Implementation

[0032] The principles and features of the present invention are described below. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0033] See also: This invention Figure 1-4 .

[0034] This invention provides an ECVT transmission power system, including an engine 1, a generator 4, a power battery pack 5, an electric motor 6, and a drive axle assembly 11, wherein the generator 4 is electrically connected to the power battery pack 5, and the power battery pack 5 is electrically connected to the electric motor 6. The output end of the engine 1 is provided with a shaft 2, which is connected to the input shaft of the generator 4. The shaft 2 is provided with an engagement clutch 3. The output end of the electric motor 6 is provided with two shafts 7, and a planetary gear mechanism is provided on the two shafts 7. The sun gear 9 of the planetary gear mechanism is connected to the two shafts 7 in a driving connection. The ring gear 8 of the planetary gear mechanism is connected to the driven end of the engagement clutch 3 in a driving connection. The planet carrier 10 of the planetary gear mechanism is connected to the input shaft of the drive axle assembly 11 in a driving connection.

[0035] principle: The drive axle assembly 11 can be a front axle or a rear axle, corresponding to front-wheel drive and rear-wheel drive tractors. The drive axle assembly 11 is an existing structure on the tractor and is considered prior art. Furthermore, the power battery pack 5 is also existing equipment in new energy vehicles, with built-in power management and charge / discharge control functions, and is considered prior art. Additionally, the driving end of the engagement clutch 3 is connected to the primary shaft 2 via transmission. The operating mode is as follows: 1. Pure electric mode, such as Figure 2 As shown: When the SOC of the power battery pack 5 is high, the engine 1 does not start, the engagement clutch 3 disengages, and the power battery pack 5 supplies power to the electric motor 6, which drives the secondary shaft 7. The power of the secondary shaft 7 is transmitted sequentially through the sun gear 9, planet gears, and planet carrier 10 of the planetary gear mechanism to the drive axle assembly 11. The pure electric mode can be used in light-load operation scenarios such as short-distance relocation.

[0036] 2. Series mode, such as Figure 3 As shown: When the SOC of the power battery pack 5 is low, the engine 1 starts and drives the first shaft 2, engaging the clutch 3 and disengaging. The first shaft 2 drives the generator 4 to generate electricity. Part of the energy charges the power battery pack 5, and the other part powers the electric motor 6 through the power battery pack 5, enabling the electric motor 6 to drive the second shaft 7. The power of the second shaft 7 is transmitted sequentially through the sun gear 9, planet gears, and planet carrier 10 of the planetary gear mechanism to the drive axle assembly 11. In series mode, the engine 1 always operates within the optimal economic range, which can be used in long-distance transportation and other operating conditions to reduce fuel consumption.

[0037] 3. Hybrid mode, such as Figure 4 As shown: During heavy field operations, the power demand is high, and engine 1 cannot guarantee that it will always operate within the economic range. At this time, engine 1 starts and drives shaft 2, and clutch 3 engages. Part of the power from engine 1 powers generator 4, and the other part drives the ring gear 8 of the planetary gear mechanism through clutch 3. At the same time, electric motor 6 drives shaft 7, which in turn drives the sun gear 9 of the planetary gear mechanism. The speed difference between the sun gear 9 and the ring gear 8 is the actual speed of the planetary gears and planet carrier 10. The planet carrier 10 outputs power to the drive axle assembly 11. Since the output speed of electric motor 6 is adjustable, the input speed of drive axle assembly 11 can be controlled by adjusting the speed of electric motor 6, thus achieving stepless speed regulation.

[0038] Furthermore, in all the above modes, the reverse / forward gear can be switched by controlling the rotation direction of the electric motor 6. When reversing the power, the vehicle speed must first be reduced to 0. At this time, the clutch 3 is engaged and disengaged, and the electric motor 6 can generate electromagnetic braking force to recover braking energy and convert it into electrical energy stored in the power battery pack 5.

[0039] This invention utilizes an electric motor 6 to drive the sun gear 9 of a planetary gear mechanism, creating a speed difference between the sun gear 9 and the ring gear 8, which is then transmitted to the planet carrier 10 for power output. The output speed can be controlled by adjusting the speed of the electric motor 6, achieving pure electric mode power output and continuously variable transmission. Furthermore, when the engine 1 starts, it can drive the generator 4 to supply power to the battery pack 5, achieving series mode power output. Simultaneously, the engine 1 can also engage the ring gear 8 of the planetary gear mechanism via the clutch 3, thus cooperating with the electric motor 6 to achieve hybrid mode power output. Therefore, this invention supports multiple mode switching, ensuring that the engine 1 operates within its economic range, improving energy efficiency, reducing fuel consumption, and lowering operating costs.

[0040] Furthermore, it also includes a brake clutch 12, one end of which is connected to the gear ring 8 of the planetary gear mechanism and can constrain or release the constraint of the gear ring 8.

[0041] Note: The other end of the brake clutch 12 is fixed to an external fixed structure, which can be a gearbox housing, frame, etc. When the brake clutch 12 is engaged, it can constrain the gear ring 8; when the brake clutch 12 is disengaged, it can release the constraint on the gear ring 8. The operation of the clutch in each of the above modes is as follows: 1. Pure electric mode: Engagement clutch 3 disengages, brake clutch 12 engages; 2. Series mode: Engagement clutch 3 disengages, brake clutch 12 engages; 3. Hybrid mode: Engagement clutch 3 engages, brake clutch 12 disengages.

[0042] The fixed / free state of the gear ring 8 of the planetary gear mechanism can be easily switched, making control convenient and operation simple.

[0043] Furthermore, the back of the gear ring 8 of the planetary gear mechanism is also provided with a shaft sleeve 13, which is rotatably sleeved on the second shaft 7.

[0044] Note: The side of the gear ring 8 away from the planet carrier is a closed surface, which is the back side. Preferably, the shaft sleeve 13 is connected to the second shaft 7 via bearings.

[0045] It facilitates stable installation of the planetary gear mechanism and reduces vibration of the gear ring 8.

[0046] Furthermore, an intervention driven gear 14 is fixedly sleeved on the shaft cylinder 13, and an intervention driving gear 15 is fixedly sleeved on the driven end of the intervention clutch 3, with the intervention driving gear 15 meshing with the intervention driven gear 14.

[0047] It facilitates the transmission between the gear ring 8 of the planetary gear mechanism and the driven end of the engagement clutch 3, resulting in high transmission efficiency and good reliability.

[0048] Furthermore, it also includes a control unit, wherein the engine 1, engagement clutch 3, power battery pack 5, electric motor 6 and brake clutch 12 are respectively connected to the control unit via signals; The control unit is used to detect the state of charge (SOC) value of the power battery pack 5, and control the engagement / disengagement state of the engagement clutch 3 and the braking clutch 12 based on the SOC value, as well as control the start / stop and speed of the engine 1 and the electric motor 6.

[0049] Note: State of Charge (SOC) is the percentage of the battery's rated capacity that remains uncharged. The control unit can be the tractor's central control system (ECU), which is existing technology.

[0050] It facilitates automatic mode switching, is easy to operate, and has a fast response speed.

[0051] Preferably, the control unit controls the engagement / disengagement state of the engagement clutch 3 and the braking clutch 12 based on the state of charge value, and controls the start / stop and speed of the engine 1 and the electric motor 6, specifically including: Obtain the input required vehicle speed and preset charge value, and monitor the state of charge (SOC) value of the power battery pack 5; perform the following operations based on the SOC value: When the state of charge value is not less than the preset state of charge value, switch to pure electric mode: control the engagement clutch 3 to disengage, control the braking clutch 12 to engage; control the engine 1 to stop, and control the electric motor 6 to rotate according to the required vehicle speed; When the state of charge value is less than the preset state of charge value, switch to series mode: control the disengagement of the intervention clutch 3, control the engagement of the brake clutch 12; control the start of the engine 1, and control the rotation of the electric motor 6 according to the required vehicle speed; In series mode, the economic speed range and economic torque range of engine 1 are obtained, and the actual speed and actual torque of engine 1 are monitored; when the actual speed is within the economic speed range and the actual torque is within the economic torque range, the series mode is maintained. When the actual engine speed exceeds the economic speed range, or the actual torque exceeds the economic torque range, the system switches to hybrid mode: the control engagement clutch 3 engages, and the control braking clutch 12 disengages; simultaneously, the speed of engine 1 and the speed of electric motor 6 are controlled according to the planetary gear set formula, which is as follows: N D +kN F =(1+k)Nx; Where, N D N is the rotational speed of motor 6. FNx is the rotational speed of engine 1, Nx is the output rotational speed of planet carrier 10, and K is the gear ratio between ring gear 8 and sun gear 9.

[0052] Note: When switching to hybrid mode, the output speed of planetary carrier 10 remains unchanged. You can first select the economical speed of engine 1 and calculate the required speed of electric motor 6 using the above formula; alternatively, you can first select the speed of electric motor 6 and calculate the required speed of engine 1 using the above formula. While controlling the clutch, you can control either engine 1 or electric motor 6 to change to the required speed. This switching process, by simultaneously controlling the speeds of engine 1 and electric motor 6, and utilizing the slippage state of the clutch, ensures that the output speed of planetary carrier 10 remains constant, and guarantees smooth power changes when switching to hybrid mode, resulting in good operational comfort. It also ensures that engine 1 operates within its economical range, reducing fuel consumption.

[0053] In addition, step C may be included: in series mode or hybrid mode, when the state of charge value rises to a value greater than the preset charge value, switch to pure electric mode.

[0054] Furthermore, a driven gear 16 is fixedly mounted on the input shaft of the generator 4, and a driving gear 17 is fixedly mounted on the shaft 2, with the driven gear 16 meshing with the driving gear 17.

[0055] It facilitates the transmission between shaft 2 and the input shaft of generator 4, with high transmission efficiency and good reliability.

[0056] Furthermore, it also includes a PTO assembly 18, whose input shaft is connected to a shaft 2 for transmission.

[0057] Note: PTO assembly 18 is an existing device on the tractor.

[0058] When the engine 1 starts, it can drive the PTO assembly 18 to work, which is convenient for providing power to external tools and equipment; the power of the engine 1 is constant, and the PTO assembly 18 has good working stability.

[0059] Furthermore, it also includes a PTO clutch 19, the driving end of which is connected to a shaft 2 for transmission, and the driven end of which is connected to the input shaft of the PTO assembly 18 for transmission.

[0060] This facilitates control of the power supply to and from the PTO assembly 18, preventing power waste.

[0061] Furthermore, it also includes a hydraulic pump 20, the input shaft of which is connected to a shaft 2 for transmission.

[0062] When the engine 1 starts, it can drive the hydraulic pump 20 to work, which facilitates the provision of power to the external hydraulic system and improves the energy utilization efficiency of the engine 1.

[0063] Furthermore, a hydraulic driven wheel 21 is fixedly sleeved on the input shaft of the hydraulic pump 20, and a hydraulic driving wheel 22 is fixedly sleeved on the shaft 2, with the hydraulic driving wheel 22 meshing with the hydraulic driven wheel 21.

[0064] It facilitates the transmission between the input shaft of the hydraulic pump 20 and the shaft 2, resulting in high transmission efficiency and good reliability.

[0065] In the description of this invention, it should be understood that if descriptive terms indicating orientation, direction, or positional relationship appear, such as "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," etc., the orientation or positional relationship indicated in this specification is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of understanding this invention and simplifying the description, and does not indicate or imply that the part, element, or whole referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0066] Furthermore, if sequential descriptive terms such as "first," "second," etc., appear, their purpose in this specification is for ease of understanding or simplification. For example, to distinguish multiple technical features of the same type or function, which must be mentioned separately, this specification may use prefixes or suffixes to differentiate them. Therefore, they should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. In the description of this invention, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0067] In this invention, if descriptive terms describing structural relationships are used, such as "installation," "connection," "joining," and "fixation," they should be interpreted broadly unless otherwise explicitly specified and limited. For example, "installation," "connection," and "joining" can refer to a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium; it can refer to the internal communication of two components or the interaction between two components. "Fixation" can refer to an integral fixation or a detachable fixation using fasteners; it can be a direct fixation or a fixation through an intermediate medium. For those skilled in the art, the specific meaning of the above descriptive terms in this invention can be understood based on the specific circumstances, the context, and the coherence of the preceding and following text.

[0068] In this invention, if descriptive terms containing subordinate or connecting meanings appear, such as "above" or "below" the second feature, they should not be interpreted restrictively unless otherwise explicitly specified and limited. For example, "above" or "below" could mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Those skilled in the art can understand the specific meaning of the above descriptive terms in this invention based on the specific circumstances, the context, and the coherence of the preceding and following text.

[0069] Furthermore, "above," "on top of," and "above" the first feature in relation to the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "under," and "below" the first feature in relation to the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0070] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. The illustrative expressions of the above terms in this specification do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments, examples, and features described in this specification, and such combinations or integrations should all fall within the scope of the present invention.

[0071] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Variations, modifications, substitutions, and modifications made by those skilled in the art to the above embodiments within the scope of information available through public channels and in conjunction with the technical teachings given in this application are still covered within the protection scope of this application.

Claims

1. An ECVT variable speed power system characterized by: The application relates to a hybrid power system, which comprises an engine (1), a generator (4), a power battery pack (5), an electric motor (6) and a drive axle assembly (11), wherein the generator (4) is electrically connected with the power battery pack (5), and the power battery pack (5) is electrically connected with the electric motor (6). The output end of the engine (1) is provided with a shaft (2), the input shaft of the generator (4) is drivingly connected with the shaft (2), and an intervening clutch (3) is arranged on the shaft (2). The output end of the electric motor (6) is provided with a second shaft (7), a planetary gear mechanism is arranged on the second shaft (7), the sun gear (9) of the planetary gear mechanism is drivingly connected with the second shaft (7), the ring gear (8) of the planetary gear mechanism is drivingly connected with the driven end of the intervening clutch (3), and the planet carrier (10) of the planetary gear mechanism is drivingly connected with the input shaft of the drive axle assembly (11).

2. The ECVT variable speed power system of claim 1, wherein: The application further comprises a brake clutch (12), one end of the brake clutch (12) is connected with the ring gear (8) of the planetary gear mechanism and can constrain or release the ring gear (8).

3. The ECVT variable speed power system of claim 2, wherein: The back surface of the ring gear (8) of the planetary gear mechanism is further provided with a shaft cylinder (13), and the shaft cylinder (13) is rotatably sleeved on the second shaft (7).

4. The ECVT variable speed power system of claim 3, wherein: An intervening driven gear (14) is fixedly sleeved on the shaft cylinder (13), the driven end of the intervening clutch (3) is fixedly sleeved with an intervening driving gear (15), and the intervening driving gear (15) is engaged with the intervening driven gear (14).

5. The ECVT variable speed power system of claim 2, wherein: The application further comprises a control unit, the engine (1), the intervening clutch (3), the power battery pack (5), the electric motor (6) and the brake clutch (12) are respectively signal-connected with the control unit. The control unit is used for detecting the state of charge value of the power battery pack (5) and controlling the clutching state of the intervening clutch (3) and the brake clutch (12) and the start-stop and rotating speed of the engine (1) and the electric motor (6) according to the state of charge value.

6. The ECVT variable speed power system of claim 5, wherein: The control unit controls the clutching state of the intervening clutch (3) and the brake clutch (12) and the start-stop and rotating speed of the engine (1) and the electric motor (6) according to the state of charge value, and specifically comprises the following steps: The input required vehicle speed and preset charge value are acquired, and the state of charge value of the power battery pack (5) is monitored; the following operations are performed according to the state of charge value: When the state of charge value is not less than the preset charge value, the pure electric mode is switched: the intervening clutch (3) is controlled to be separated, the brake clutch (12) is controlled to be combined, the engine (1) is controlled to be stopped, and the electric motor (6) is controlled to rotate according to the required vehicle speed; When the state of charge value is less than the preset charge value, the series mode is switched: the intervening clutch (3) is controlled to be separated, the brake clutch (12) is controlled to be combined, the engine (1) is controlled to be started, and the electric motor (6) is controlled to rotate according to the required vehicle speed; In the series mode, the input engine (1) economic rotating speed interval and economic torque interval are acquired, and the actual rotating speed and actual torque of the engine (1) are monitored; when the actual rotating speed is in the economic rotating speed interval and the actual torque is in the economic torque interval, the series mode is kept; When the actual speed exceeds the economic speed range, or the actual torque exceeds the economic torque range, switch to the hybrid mode: control the clutch (3) to engage, control the brake clutch (12) to disengage; at the same time, control the speed of the engine (1) and the speed of the motor (6) according to the planetary gear formula, and the planetary gear formula is as follows: N D +kN F = (1 + k) Nx; where N D is the rotational speed of the electric motor (6), N F is the rotational speed of the engine (1), Nx is the output rotational speed of the planet carrier (10), and K is the gear ratio of the ring gear (8) to the sun gear (9).

7. The ECVT variable speed power system of claim 1, wherein: The input shaft of the generator (4) is fixedly sleeved with a power generation driven gear (16), and the one shaft (2) is fixedly sleeved with a power generation driving gear (17), and the power generation driven gear (16) is engaged with the power generation driving gear (17).

8. The ECVT variable speed power system of claim 1, wherein: Further comprising a PTO assembly (18), the input shaft of the PTO assembly (18) is drivingly connected with the one shaft (2).

9. The ECVT variable speed power system of claim 8, wherein: Further comprising a PTO clutch (19), the driving end of the PTO clutch (19) is drivingly connected with the one shaft (2), and the driven end of the PTO clutch (19) is drivingly connected with the input shaft of the PTO assembly (18).

10. The ECVT variable speed power system of claim 1, wherein: Further comprising a hydraulic pump (20), the input shaft of the hydraulic pump (20) is drivingly connected with the one shaft (2); The input shaft of the hydraulic pump (20) is fixedly sleeved with a hydraulic driven wheel (21), and the one shaft (2) is fixedly sleeved with a hydraulic driving wheel (22), and the hydraulic driving wheel (22) is engaged with the hydraulic driven wheel (21).

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