CN219007575U

CN219007575U - Power transmission device and hybrid electric vehicle

Info

Publication number: CN219007575U
Application number: CN202223546859.1U
Authority: CN
Inventors: 李瑶瑶; 赵江灵; 赵成飞
Original assignee: Guangzhou Automobile Group Co Ltd
Current assignee: Guangzhou Automobile Group Co Ltd
Priority date: 2022-12-28
Filing date: 2022-12-28
Publication date: 2023-05-12
Anticipated expiration: 2032-12-28

Abstract

The present application relates to a power transmission device and a hybrid vehicle. The power transmission device includes: the device comprises an engine, a generator, a driving motor, a planetary gear transmission mechanism, a synchronizer, a brake, a first transmission shaft, a second transmission shaft, a first three-gear output gear, a second-gear input gear and a second-gear output gear meshed with the second-gear input gear; the engine is in transmission connection with the generator through a first transmission shaft, and the first transmission shaft is driven by the engine so as to realize the power generation function of the generator; the planetary gear transmission mechanism comprises a gear ring, a planet wheel connected in the gear ring, a planet carrier and a sun wheel; the sun gear and the synchronizer are fixedly connected to the first transmission shaft; the first gear output gear is fixedly connected to the first transmission shaft, and the second gear output gear is meshed with the planet carrier; the driving motor is in transmission connection with the second transmission shaft. It not only can provide multiple drive mode, but also effectively promotes dynamic nature and economic nature.

Description

Power transmission device and hybrid electric vehicle

Technical Field

The application belongs to the technical field of automobiles, and particularly relates to a power transmission device and a hybrid electric vehicle.

Background

With the globalization of petroleum energy pressure, hybrid technology has become another break-through for pressure relief. The prior hybrid power system is mainly divided into three directions, namely a series-connection type hybrid power system, a parallel-connection type hybrid power system and a series-parallel connection type hybrid power system.

The series connection type electric energy is directly supplied to the driving motor to drive the vehicle to run or stored in the power battery by means of the generator driven by the engine, the system is simple in structure, the torque of the engine is decoupled from the wheel end, and the engine can be effectively controlled to work in a high-efficiency interval. However, the efficiency loss of a transmission chain length system is high, so that the oil saving capability is limited; and under the condition that the vehicle is required to be capable of covering various working condition demands, the power selection of the driving motor, the generator and the engine is required to be large, and the problems of cost rise and arrangement are caused.

The parallel connection type engine and the driving motor are used for jointly outputting power to meet the power requirement of a vehicle, the torque requirement on the motor is small, and the size of a battery can be effectively reduced. However, the engine speed cannot be decoupled from the vehicle speed, so that the adjustment capability of the high-efficiency area of the engine is limited, and the oil-saving effect is limited.

The series-parallel connection type integrates the advantages of the series connection type and the parallel connection type, can be designed according to the object of the vehicle, and has larger oil saving space on the premise of meeting the power performance requirement of the whole vehicle. The disadvantage is that the control difficulty is large according to the complexity of the system.

Disclosure of Invention

An object of the present application is to provide a power transmission device and a hybrid vehicle, which can not only provide various driving modes, but also effectively promote dynamic property and economical efficiency.

The first aspect of the present application discloses a power transmission device comprising: the device comprises an engine, a generator, a driving motor, a planetary gear transmission mechanism, a synchronizer, a brake, a first transmission shaft, a second transmission shaft, a first three-gear output gear, a second-gear input gear and a second-gear output gear meshed with the second-gear input gear; the engine is in transmission connection with the generator through the first transmission shaft, and the first transmission shaft is driven by the engine so as to realize the power generation function of the generator; the planetary gear transmission mechanism comprises a gear ring, and a planet wheel, a planet carrier and a sun wheel which are connected in the gear ring; the sun gear and the synchronizer are fixedly connected to the first transmission shaft; the first third-gear output gear and the second-gear output gear are respectively and fixedly connected to the second transmission shaft, and the first third-gear output gear is also meshed with the planet carrier; the driving motor is in transmission connection with the second transmission shaft, and transmits power to driving wheels through the second transmission shaft; when the brake is closed, the gear ring is fixedly connected to the first transmission shaft and moves along with the first transmission shaft; when the brake is disconnected, the gear ring is sleeved on the first transmission shaft in an empty mode to move; when the synchronizer is closed, one of the planet carrier and the second-gear input gear is fixed on the first transmission shaft, and the other is sleeved on the first transmission shaft in an empty mode; when the synchronizer is completely disconnected, the planet carrier and the second-gear input gear are both sleeved on the first transmission shaft in an empty mode.

In an exemplary embodiment of the present application, the power transmission device further includes a main reduction gear set, a driving motor transmission shaft, a driving motor input gear and a driving motor output gear, the main reduction gear set is in transmission connection with the second transmission shaft, the driving motor is in transmission connection with the driving motor input gear through the driving motor transmission shaft, the driving motor input gear is meshed with the driving motor output gear, and the driving motor output gear is in transmission connection with the main reduction gear set.

In an exemplary embodiment of the present application, the driving motor output gear is the second gear output gear.

In an exemplary embodiment of the present application, the power transmission device further includes a third transmission shaft, and the driving motor output gear and the main reduction gear set are both fixedly connected to the third transmission shaft.

In one exemplary embodiment of the present application, the main reduction gear set includes a first main reduction input gear, a second main reduction input gear, and a main reduction output gear; wherein the first main reduction input gear and the second main reduction input gear are both meshed with the main reduction output gear; the first main speed reduction input gear is fixedly connected with the second transmission shaft; the second main speed reduction input gear is fixedly connected to the third transmission shaft.

In an exemplary embodiment of the present application, the driving motor output gear is fixedly connected to the second transmission shaft.

In an exemplary embodiment of the present application, the power transmission device further includes a generator input gear and a generator output gear, the generator input gear is fixedly connected with a generator transmission shaft of the generator, the generator input gear is meshed with the generator output gear, and the generator output gear is connected with the first transmission shaft.

In an exemplary embodiment of the present application, the synchronizer is a double-sided synchronizer, the double-sided synchronizer being located between the planet carrier and the second gear input gear; when one side of the bilateral synchronizer is closed, the planet carrier is fixed on the first transmission shaft, and the second-gear input gear is sleeved on the first transmission shaft; when the second-gear input gear on the other side of the bilateral synchronizer is closed, the second-gear input gear is fixed on the first transmission shaft, and the planetary overhead sleeve is sleeved on the first transmission shaft; when both sides of the bilateral synchronizer are disconnected with the planet carrier and the second-gear input gear, the planet carrier and the second-gear input gear are sleeved on the first transmission shaft in an empty mode.

In an exemplary embodiment of the present application, the synchronizer includes a first single-sided synchronizer and a second single-sided synchronizer, both of which are connected to the first transmission shaft; when the first unilateral synchronizer is closed with the planet carrier, the planet carrier is fixedly connected to the first transmission shaft; when the first unilateral synchronizer is disconnected with the planet carrier, the planet overhead is sleeved on the first transmission shaft; when the second unilateral synchronizer is closed with the second gear input gear, the second gear input gear is fixedly connected to the first transmission shaft; when the second unilateral synchronizer is disconnected with the second gear input gear, the second gear input gear is sleeved on the first transmission shaft in a hollow mode.

A second aspect of the present application discloses a hybrid vehicle comprising drive wheels and the power transmission device described above for driving the drive wheels.

The scheme of the application has the following beneficial effects:

in the embodiment of the application, the power transmission device can change the transmission mode of the planetary gear transmission mechanism by controlling the opening and closing of the brake and the synchronizer, so that an engine direct drive mode of three gears, a single-motor pure electric mode of four gears, a hybrid power drive mode of three gears and a series mode are finally realized, and the power performance and the economy can be effectively improved; the influence of the characteristic parameters of the planetary gear transmission mechanism on the selection of the step ratio is overcome; and the powerless interrupt gear shifting is realized. Wherein, gear combination is realized through the planetary gear transmission mechanism, the axial dimension of the power transmission device can be effectively reduced. And moreover, the engine and the generator realize primary gear speed and torque rising and falling through the first transmission shaft, so that the size of the generator can be effectively reduced.

Other features and advantages of the present application will be apparent from the following detailed description, or may be learned in part by the practice of the application.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the application and together with the description, serve to explain the principles of the application. It is apparent that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained from these drawings without inventive effort for a person of ordinary skill in the art.

Fig. 1 shows a schematic structural diagram of a power transmission device according to an embodiment of the present application.

Fig. 2 shows a schematic structural diagram of a power transmission device according to a second embodiment of the present application.

Fig. 3 shows a schematic structural diagram of a power transmission device according to a third embodiment of the present application.

Fig. 4 shows a schematic structural diagram of a power transmission device according to a fourth embodiment of the present application.

Reference numerals illustrate:

1. an engine; 2. a generator; 3. a driving motor; 4. a first drive shaft; 5. a second drive shaft; 6. a generator drive shaft; 7. a drive motor drive shaft; 8. a sun gear; 9. a planet wheel; 10. a gear ring; 11. a planet carrier; 12. a third gear output gear; 13. a second gear input gear; 14. a second gear output gear; 15. a generator input gear; 16. a generator output gear; 17. driving a motor input gear; 18. a main reduction input gear; 19. a main reduction output gear; 20. a differential; 21. a half shaft; 22. driving a motor output gear; 23. a third drive shaft; B. a brake; s, a bilateral synchronizer; s1, a first unilateral synchronizer; s2, a second unilateral synchronizer.

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. However, the exemplary embodiments may be embodied in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the example embodiments to those skilled in the art.

Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments of the present application. One skilled in the relevant art will recognize, however, that the aspects of the application can be practiced without one or more of the specific details, or with other methods, components, devices, steps, etc. In other instances, well-known methods, devices, implementations, or operations are not shown or described in detail to avoid obscuring aspects of the application.

The present application is further described in detail below with reference to the drawings and specific examples. It should be noted that the technical features of the embodiments of the present application described below may be combined with each other as long as they do not collide with each other. The embodiments described below by referring to the drawings are exemplary and intended for the purpose of explaining the present application and are not to be construed as limiting the present application.

Example 1

As shown in fig. 1, a first embodiment discloses a hybrid vehicle including a power transmission device and drive wheels. Wherein the power transmission device is used for providing driving force for driving wheels.

In some embodiments, a power transmission device includes: an engine 1, a generator 2 and a drive motor 3. Wherein, the engine 1 can drive the generator 2 to generate electricity, and the generated electricity is directly supplied to the driving motor 3 to drive the vehicle to run or stored in the power battery; alternatively, the engine 1 and the drive motor 3 jointly output power to satisfy the power demand of the vehicle, and the like.

The following describes the transmission connection modes of the engine 1, the generator 2 and the driving motor 3 in detail:

in some embodiments, the power transmission device further comprises a first drive shaft 4. The engine 1 is in transmission connection with the generator 2 through the first transmission shaft 4, and the first transmission shaft 4 is driven by the engine 1 to realize the power generation function of the generator 2.

The power transmission device further comprises a generator input gear 15 and a generator output gear 16 meshed with the generator input gear 15, wherein the generator input gear 15 is fixedly connected with the generator transmission shaft 6 of the generator 2, the generator input gear 15 is meshed with the generator output gear 16, and the generator output gear 16 is connected with the first transmission shaft 4, so that the primary fixed-shaft transmission gear is connected.

In some embodiments, the power transmission further comprises a planetary gear transmission. The planetary gear transmission comprises a ring gear 10, and planet gears 9, a planet carrier 11 and a sun gear 8 connected within the ring gear 10. The sun gear 8 is fixedly connected to the first transmission shaft 4 and can move along with the first transmission shaft 4.

Further, the power transmission device further comprises a synchronizer fixedly connected to the first transmission shaft 4 and a brake B for locking the ring gear 10.

The synchronizer is, for example, a double-sided synchronizer S, which is located between the carrier 11 and the second-gear input gear 13. The double-sided synchronizer S can be controlled to be meshed with or separated from the planet carrier 11 or the second gear input gear 13 by moving left and right, and the double-sided synchronizer S is adopted to enable the power transmission device to be higher in integration degree in the axial direction relative to the single-sided synchronizer.

It should be understood that when the planet carrier 11 on one side of the double-sided synchronizer S is closed, the planet carrier 11 is fixed on the first transmission shaft 4, and the second gear input gear 13 is sleeved on the first transmission shaft 4; when the second-gear input gear 13 on the other side of the bilateral synchronizer S is closed, the second-gear input gear 13 is fixed on the first transmission shaft 4, and the planet carrier 11 is sleeved on the first transmission shaft 4 in an empty mode; when both sides of the double-sided synchronizer S are disconnected from the planet carrier 11 and the second-gear input gear 13, the planet carrier 11 and the second-gear input gear 13 are both sleeved on the first transmission shaft 4.

When the brake B is closed, the gear ring 10 is fixedly connected to the first transmission shaft 4 and moves along with the first transmission shaft 4; when the brake B is disconnected, the gear ring 10 is sleeved on the first transmission shaft 4.

Further, the power transmission device further includes a third-gear output gear 12, a second-gear input gear 13, and a second-gear output gear 14 meshed with the second-gear input gear 13. A third gear output gear 12 is meshed with the planet carrier 11, and a second gear input gear 13 is mounted on the first transmission shaft 4.

Illustratively, the carrier 11 and a third-speed output gear 12 are a pair of meshing gears; the second-gear input gear 13 and the second-gear output gear 14 are a pair of meshing gears

It should be understood that when the synchronizer is closed, one of the planet carrier 11 and the second-gear input gear 13 is fixed on the first transmission shaft 4, and the other is sleeved on the first transmission shaft 4; when the synchronizer is completely disconnected, the planet carrier 11 and the second gear input gear 13 are both sleeved on the first transmission shaft 4 in an empty mode.

In some embodiments, the power transmission device further comprises a second transmission shaft 5, and a third-gear output gear 12 and a second-gear output gear 14 are respectively fixedly connected to the second transmission shaft 5. The driving motor 3 is in transmission connection with the second transmission shaft 5 and transmits power to the driving wheels through the second transmission shaft 5.

The power transmission also includes, for example, a main reduction gear set, a drive motor drive shaft 7, a drive motor input gear 17, and a drive motor output gear. The main reduction gear set is in transmission connection with the second transmission shaft 5, the driving motor 3 is in transmission connection with the driving motor input gear 17 through the driving motor transmission shaft 7, the driving motor input gear 17 is meshed with the driving motor output gear, and the driving motor output gear 22 is in transmission connection with the main reduction gear set.

In some embodiments, the driving motor output gear is a second gear output gear 14, that is, the driving motor output gear is shared with the second gear output gear 14, so as to reduce the number of gears, reduce the transmission chain length, and effectively control the engine 1 to work in a high-efficiency zone.

The main reduction gear set includes a main reduction input gear 18 and a main reduction output gear 19, and the main reduction input gear 18 and the main reduction output gear 19 are a pair of meshing gears. The main reduction input gear 18 is in driving connection with the second drive shaft 5, and the main reduction output gear 19 is in mesh with the main reduction input gear 18.

In some embodiments, the power transmission further includes a differential 20 and axle shafts 21, the differential 20, axle shafts 21 being cooperatively coupled with the main reduction output gear 19, the axle shafts 21 being for coupling with the drive wheels.

The following describes the working principle of the power transmission device in detail:

when the brake B is in the off state and the double-sided synchronizer S is in the full off state (the double-sided synchronizer S is not connected with the planet carrier 11 and the second gear input gear 13), the driving motor 3 transmits power to the driving motor input gear 17 through the driving motor transmission shaft 7, and then transmits power to the driving wheels through the second gear output gear 14, the second transmission shaft 5, the main speed reduction input gear 18, the main speed reduction output gear 19, the differential 20 and the half shaft 21 which are meshed with the driving motor input gear 17, so that pure electric driving is realized.

When the brake B is in the off state and the double-sided synchronizer S is in the full off state (the double-sided synchronizer S is not connected with the planet carrier 11 and the second gear input gear 13), the power of the engine 1 is transmitted to the generator 2 through the first transmission shaft 4, the generator output gear 16 and the generator input gear 15 to realize idle power generation. In this case, the drive motor 3 transmits power to the drive motor input gear 17 via the drive motor transmission shaft 7, and transmits power to the drive wheels via the secondary gear output gear 14, the primary reduction input gear 18, the primary reduction output gear 19, the differential 20, and the half shaft 21 engaged therewith, thereby achieving the range-extending drive.

When the brake B is closed and the double-sided synchronizer S is in a completely opened state (the double-sided synchronizer S is not connected with the carrier 11 and the second-gear input gear 13), the power of the engine 1 is transmitted to the first transmission shaft 4, and since the brake B is closed, the ring gear 10 is locked, and the power of the engine 1 is transmitted to the second transmission shaft 5 through the sun gear 8, the carrier 11, and the third-gear output gear 12 engaged therewith. Then, the engine 1 drive of one gear is achieved by transmitting to the wheels through the main reduction input gear 18, the main reduction output gear 19, the differential 20, and the half shafts 21.

When the brake B is in the off state, the double-sided synchronizer S moves to engage with the carrier 11 and separate from the second-gear input gear 13; the power of the engine 1 is transmitted to the first transmission shaft 4, and since the double-sided synchronizer S moves to mesh with the carrier 11, the carrier 11 and the first transmission shaft 4 are locked, and the power of the engine 1 is transmitted to the second transmission shaft 5 through the carrier 11 and a third-gear output gear 12 meshed therewith. Then, the engine 1 drive of one gear is achieved by transmitting to the wheels through the main reduction input gear 18, the main reduction output gear 19, the differential 20, and the half shafts 21.

When the brake B is in an off state, the double-sided synchronizer S moves to be separated from the carrier 11 and engaged with the second-gear input gear 13; the power of the engine 1 is transmitted to the first transmission shaft 4, and the double-sided synchronizer S is meshed with the second-gear input gear 13, so that the second-gear input gear 13 and the first transmission shaft 4 are locked, and the power of the engine 1 is transmitted to the second transmission shaft 5 through the second-gear input gear 13 and the second-gear output gear 14 meshed with the second-gear input gear 13. Then, the engine 1 drive of one gear is achieved by transmitting to the drive wheels through the main reduction input gear 18, the main reduction output gear 19, the differential 20, and the half shafts 21.

In addition, when the engine 1 is driven in three different gears, the driving motor 3 and the generator 2 can also participate in driving or generating power, thereby realizing a hybrid driving mode of three gears.

In summary, the power transmission device of the embodiment has a direct-drive mode, a pure electric mode, a series range-extending mode, three hybrid power driving modes of the engine 1 with three gears, and multiple working modes such as braking energy recovery, parking power generation and the like, and can automatically switch different modes according to states such as a battery SOC value, pedal opening, vehicle speed and the like, so that the power performance and economy can be effectively improved. Secondly, the generator 2 and the engine 1 realize primary gear lifting and torque reduction, so that the volume of the generator 2 can be effectively reduced, and the influence of the characteristic parameters of the planet row on the step ratio selection is overcome; the torque of the starting driving motor 3 can be directly output to driving wheels, the torque response is quick, and the powerless interruption gear shifting can be realized; in addition, through the gear combination of planet row realization, can effectively reduce axial dimensions, two sets of meshing gears realize the three gears of engine 1, can effectively reduce the gear number of meshing, can cover HEV motorcycle type and PHEV motorcycle type, and the platformization is good.

Example two

As shown in fig. 2, the hybrid vehicle in the present embodiment is substantially the same as the hybrid vehicle in the first embodiment, except that the driving manner of the driving motor 3 of the power transmission device in the present embodiment and the driving manner of the driving motor 3 of the power transmission device in the first embodiment enable the driving motor 3 to directly input power to the main reduction gear set, further accelerate the torque response, and the arrangement position of the driving motor 3 is not affected by the second-speed output gear.

Further, the main reduction gear set includes a first main reduction input gear 18a, a second main reduction input gear 18b, and a main reduction output gear 19; wherein the first main reduction input gear 18a and the second main reduction input gear 18b are both meshed with the main reduction output gear 19; the first main reduction input gear 18a is fixedly connected with the second transmission shaft 5; the second main reduction input gear 18b is fixedly connected to the third drive shaft 23.

For other structures of the power transmission device, please refer to the first embodiment, and the description thereof is omitted.

Example III

As shown in fig. 3, the hybrid vehicle in this embodiment is substantially the same as the hybrid vehicle in the first embodiment, except that the drive motor 3 of the power transmission device in this embodiment is driven in a different manner from the drive motor 3 of the power transmission device in the first embodiment. Specifically:

in the present embodiment, the drive motor output gear 22 is fixedly connected to the second transmission shaft 5, and transmits power to the drive wheels through the second transmission shaft 5, the main reduction gear set, the differential 20, and the half shaft 21, so that the arrangement position of the drive motor 3 can be made unaffected by the main reduction gear set.

Illustratively, the main reduction input gear 18 of the main reduction gear set is located at one end of the second drive shaft 5, the drive motor output gear 22 is located at the other end of the second drive shaft 5, and the second gear output gear 14 and the first and third gear output gears are located between the main reduction input gear 18 and the drive motor output gear 22.

Example IV

The hybrid vehicle in this embodiment is substantially the same as the hybrid vehicle in the first embodiment, except that the synchronizer of the power transmission device in this embodiment is different from the synchronizer of the power transmission device in the first embodiment. Specifically:

as shown in fig. 4, in the present embodiment, the synchronizer includes a first single-side synchronizer S1 and a second single-side synchronizer S2, and the first single-side synchronizer S1 and the second single-side synchronizer are both connected to the first transmission shaft 4. The first single-side synchronizer S1 is positioned on one side of the second-gear input gear 13 close to the planet carrier 11, and the second single-side synchronizer S2 is positioned on one side of the second-gear input gear 13 far from the planet carrier 11.

It will be appreciated that the use of a single-sided synchronizer can make the arrangement position of the synchronizer more flexible with respect to the double-sided synchronizer S. When the first unilateral synchronizer S1 and the planet carrier 11 are closed, the planet carrier 11 is fixedly connected to the first transmission shaft 4 and can move along with the first transmission shaft 4; when the first unilateral synchronizer S1 is disconnected from the planet carrier 11, the planet carrier 11 is sleeved on the first transmission shaft 4 in an empty mode; when the second unilateral synchronizer S2 and the second gear input gear 13 are closed, the second gear input gear 13 is fixedly connected to the first transmission shaft 4 and can move along with the first transmission shaft 4; when the second unilateral synchronizer S2 is disconnected from the second gear input gear 13, the second gear input gear 13 is sleeved on the first transmission shaft 4.

For other structures of the power transmission device, please refer to the first, second or third embodiments, and the description thereof is omitted herein.

In this application, unless explicitly stated and limited otherwise, the terms "mounted," "connected," and the like are to be construed broadly, and may be, for example, fixedly attached, detachably attached, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art as the case may be.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. The meaning of "a plurality of" is two or more, unless specifically defined otherwise. And the description of the terms "some embodiments," "illustratively," and the like, means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application.

The schematic representations of the above terms are not necessarily for the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.

While embodiments of the present application have been shown and described, it should be understood that the above embodiments are illustrative and not to be construed as limiting the application, and that variations, modifications, alternatives and variations may be made to the embodiments by one of ordinary skill in the art within the scope of the application, and all such variations or modifications are intended to be included within the scope of the utility model as defined by the claims and specification of the application.

Claims

1. A power transmission device, comprising: the device comprises an engine, a generator, a driving motor, a planetary gear transmission mechanism, a synchronizer, a brake, a first transmission shaft, a second transmission shaft, a first three-gear output gear, a second-gear input gear and a second-gear output gear meshed with the second-gear input gear; wherein,,

the engine is in transmission connection with the generator through the first transmission shaft, and the first transmission shaft is driven by the engine so as to realize the power generation function of the generator;

the planetary gear transmission mechanism comprises a gear ring, and a planet wheel, a planet carrier and a sun wheel which are connected in the gear ring;

the sun gear and the synchronizer are fixedly connected to the first transmission shaft;

the first third-gear output gear and the second-gear output gear are respectively and fixedly connected to the second transmission shaft, and the first third-gear output gear is also meshed with the planet carrier;

the driving motor is in transmission connection with the second transmission shaft, and transmits power to driving wheels through the second transmission shaft;

when the brake is closed, the gear ring is fixedly connected to the first transmission shaft and moves along with the first transmission shaft;

when the brake is disconnected, the gear ring is sleeved on the first transmission shaft in an empty mode to move;

when the synchronizer is closed, one of the planet carrier and the second-gear input gear is fixed on the first transmission shaft, and the other is sleeved on the first transmission shaft in an empty mode;

when the synchronizer is completely disconnected, the planet carrier and the second-gear input gear are both sleeved on the first transmission shaft in an empty mode.

2. The power transmission device of claim 1, further comprising a main reduction gear set, a drive motor drive shaft, a drive motor input gear, and a drive motor output gear, wherein the main reduction gear set is drivingly connected to the second drive shaft, the drive motor is drivingly connected to the drive motor input gear via the drive motor drive shaft, the drive motor input gear is meshed with the drive motor output gear, and the drive motor output gear is drivingly connected to the main reduction gear set.

3. The power transmission device according to claim 2, wherein the drive motor output gear is the two-speed output gear.

4. The power transmission device of claim 2, further comprising a third drive shaft, wherein the drive motor output gear and the main reduction gear set are both fixedly connected to the third drive shaft.

5. The power transmission device of claim 4, wherein the main reduction gear set includes a first main reduction input gear, a second main reduction input gear, and a main reduction output gear; wherein,,

the first main speed reduction input gear and the second main speed reduction input gear are meshed with the main speed reduction output gear;

the first main speed reduction input gear is fixedly connected with the second transmission shaft;

the second main speed reduction input gear is fixedly connected to the third transmission shaft.

6. A power transmission device according to claim 3, wherein the drive motor output gear is fixedly connected to the second drive shaft.

7. The power transmission device of claim 1, further comprising a generator input gear and a generator output gear, the generator input gear being fixedly connected to a generator drive shaft of the generator, the generator input gear being meshed with the generator output gear, the generator output gear being connected to the first drive shaft.

8. The power transmission device according to any one of claims 1 to 7, wherein the synchronizer is a double-sided synchronizer, the double-sided synchronizer being located between the carrier and the second-gear input gear;

when one side of the bilateral synchronizer is closed, the planet carrier is fixed on the first transmission shaft, and the second-gear input gear is sleeved on the first transmission shaft;

when the second-gear input gear on the other side of the bilateral synchronizer is closed, the second-gear input gear is fixed on the first transmission shaft, and the planetary overhead sleeve is sleeved on the first transmission shaft;

when both sides of the bilateral synchronizer are disconnected with the planet carrier and the second-gear input gear, the planet carrier and the second-gear input gear are sleeved on the first transmission shaft in an empty mode.

9. The power transmission device according to any one of claims 1 to 7, wherein the synchronizer includes a first single-sided synchronizer and a second single-sided synchronizer, both of which are connected to the first transmission shaft; wherein,,

when the first unilateral synchronizer is closed with the planet carrier, the planet carrier is fixedly connected to the first transmission shaft; when the first unilateral synchronizer is disconnected with the planet carrier, the planet overhead is sleeved on the first transmission shaft;

when the second unilateral synchronizer is closed with the second gear input gear, the second gear input gear is fixedly connected to the first transmission shaft; when the second unilateral synchronizer is disconnected with the second gear input gear, the second gear input gear is sleeved on the first transmission shaft in a hollow mode.

10. A hybrid vehicle comprising drive wheels and a power transmission device according to any one of claims 1-9 for driving the drive wheels.