Extended-range hybrid power system, vehicle and method of extended-range hybrid power system

Abstract

The invention provides a range extending type hybrid power system, a vehicle and a method thereof, the range extending type hybrid power system comprises two planet rows, the first planet row comprises a first planet wheel, a first sun wheel and a first planet carrier, and the second planet row comprises a second planet wheel, a second sun wheel and a second planet carrier; the first planet carrier is connected with the input shaft, the input shaft is connected with the engine, the first planet wheel is connected with the first planet carrier, and the first sun wheel is connected with the generator; the second planet carrier is connected with an output shaft, the output shaft is used for being connected with a wheel end, the second planet wheel is connected with the second planet carrier, and the second sun wheel is connected with the driving motor; the first planet row and the second planet row share one gear ring, and the brake is connected with the gear ring so as to lock or release the gear ring. The range extender is simple in structure and not complex in control logic, and the problem that an existing range extender is high in energy consumption is effectively solved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of hybrid power devices, and particularly relates to a range-extender hybrid power system, a vehicle and a method thereof. BACKGROUND

[0002] The statements in this section merely provide background information related to the present application and do not necessarily constitute prior art.

[0003] With the increasingly strict environmental protection measures in the world, low-emission and low-energy-consumption hybrid electric vehicles have become one of the main streams of current automobile industry development.

[0004] The range-extender hybrid electric vehicle is an important type of hybrid electric vehicle, but the existing range-extender hybrid power system generally comprises an engine, a generator and a driving generator, the engine and the generator are connected, the driving generator is connected to an output shaft, and in operation, the engine only drives the generator to generate electricity and does not participate in driving the vehicle, and only the driving generator drives the vehicle in any working condition.

[0005] Especially when the vehicle is running at high speed, the driving generator is in a high-speed state for a long time, which increases the wear and heat generation of mechanical parts, causes the efficiency to decrease, and increases the power consumption. If the energy of the engine can only be converted into the power of the driving generator through the generator, the demand cannot be met in the scene of high energy consumption demand. The conversion efficiency of the generator and the driving generator of the general range-extender vehicle is 90% to 95%, the total efficiency of the output energy after the conversion of the generator and the driving generator is about 81% to 90%, and compared with the transmission efficiency of about 97% to 99% of the engine direct drive, the conversion efficiency is low, and the energy of the engine cannot be fully utilized.

[0006] Currently, some researchers propose to use a double planetary gear set structure to improve the hybrid power system, but most of these schemes have the problems of needing multiple sets of gear rings, clutches and brakes, or adding several groups of reducers and gears for cooperation, the structure and control logic are relatively complex, and the cost is high. Some of them have the problems of high cost and large size and power of the motor due to the fact that the motor participates in both charging and driving. SUMMARY

[0007] In order to solve the above problems, the present application proposes a range-extender hybrid power system, a vehicle and a method thereof, which has a simple structure and a simple control logic, realizes the engine direct drive mode of the range-extender hybrid vehicle when running at high speed, and effectively solves the problem of high energy consumption of the existing range-extender in the high-speed running condition.

[0008] According to some embodiments, the present application adopts the following technical scheme: A range extending hybrid system, comprising an engine, a brake, a generator, a drive motor, a first planetary gear set, a second planetary gear set and a ring gear, wherein: The first planetary gear set comprises a first planetary gear, a first sun gear and a first carrier, and the second planetary gear set comprises a second planetary gear, a second sun gear and a second carrier; The first carrier is connected with an input shaft, the input shaft is connected with the engine, the first planetary gear is connected with the first carrier, and the first sun gear is connected with the generator; The second carrier is connected with an output shaft, the output shaft is used to be connected with a wheel end, the second planetary gear is connected with the second carrier, and the second sun gear is connected with the drive motor; The first planetary gear set and the second planetary gear set share one ring gear, and the brake is connected with the ring gear to lock or release the ring gear.

[0009] In the above scheme, only one brake and one ring gear are needed, without auxiliary devices such as clutches, and the energy transmission and control among the engine, the generator and the drive motor can be realized by locking or releasing the ring gear with the brake, the switching of different working modes is realized, the structure is simple, the control logic is simple, and the problem of high energy consumption of the existing range extender is effectively solved.

[0010] By closing or opening the brake, locking or releasing the ring gear, i.e. controlling the ring gear to be fixed or movable, and cooperating with the torque control of the drive motor, the range extending hybrid transmission can be switched among the three driving forms of pure electric drive, engine direct drive and hybrid drive, and the problems of high energy consumption and insufficient overtaking power of the existing range extender under high-speed driving conditions are effectively solved. As an optional implementation, a battery pack is arranged between the generator and the drive motor, the battery pack is used to store the electric energy generated by the generator and provide electric energy to the drive motor.

[0011] As an optional implementation, the first planetary gear is engaged with the first sun gear, and the second planetary gear is engaged with the second sun gear.

[0012] As an optional implementation, the range extending hybrid system comprises a speed increasing mode, when the range extending hybrid system is in this mode, the brake is closed, the ring gear is locked / fixed, the torque of the engine is transmitted to the first sun gear through the input shaft and the first carrier, the generator is driven to generate electricity, the electric energy is transmitted to the drive motor, the torque of the drive motor is transmitted to the second carrier through the second sun gear and the second planetary gear connected with the drive motor, and is output to the wheel end through the output shaft.

[0013] In this mode, the speed of the wheel end can be changed by regulating the speed of the driving motor without shifting gears, which can ensure smooth driving of the vehicle, improve the comfort of the vehicle, and keep the engine working in the best energy consumption area to effectively reduce fuel consumption.

[0014] As an alternative embodiment, the extended-range hybrid system includes a direct drive mode, when the extended-range hybrid system is in this mode, the brake is always open, the ring gear is released / active, and the torque of the engine is transmitted to the wheel end through the input shaft, the first planet carrier, the first planet gear, the ring gear, the second planet gear, the second planet carrier, and the output shaft.

[0015] In this mode, the generator and the driving motor are idling, and the torque of the engine is directly transmitted to the wheel end, so that the vehicle is in a high-speed driving state, the engine direct drive transmission efficiency is high, and the fuel economy is optimal.

[0016] As an alternative embodiment, the extended-range hybrid system includes an overtaking mode, when the extended-range hybrid system is in this mode, the brake is always open, the ring gear is released / active, the torque of the engine is transmitted to the wheel end through the input shaft, the first planet carrier, the first planet gear, the ring gear, the second planet gear, the second planet carrier, and the output shaft, and the torque of the driving motor is transmitted to the second planet carrier through the second sun gear and the second planet gear, and is coupled with the torque transmitted by the engine to be transmitted to the output shaft and output to the wheel end.

[0017] In this mode, the torque of the driving motor serves as auxiliary power and is coupled with the torque of the engine to increase the overall torque and provide sufficient power for high-speed overtaking of the vehicle.

[0018] As an alternative embodiment, the extended-range hybrid system includes an energy recovery mode, when the extended-range hybrid system is in this mode, the torque is transmitted from the wheel end, the output shaft, the second planet carrier, the second planet gear, and the second sun gear to the driving motor, and at this time the driving motor generates electricity.

[0019] In this mode, on the one hand, the driving motor can recover energy to reduce the energy consumption of the vehicle, and on the other hand, the driving motor can provide braking force to slow down the vehicle.

[0020] As an alternative embodiment, the input shaft and the output shaft are coaxially arranged; The input shaft is connected to the engine through a torsional damper.

[0021] An extended-range hybrid vehicle includes the above-mentioned extended-range hybrid system with a double planetary gear structure.

[0022] A control method based on the above-mentioned vehicle includes the following steps: When the extended-range hybrid system is in the extended-range mode, the control brake is normally closed, the gear ring is locked / fixed, the engine only drives the generator to generate electricity, and the electric energy generated by the generator is used to drive the motor to drive the vehicle; When the extended-range hybrid system is in the direct-drive mode, the control brake is normally open, the gear ring is released / movable, and the engine directly drives the vehicle. When the extended-range hybrid system is in the overtaking mode, the control brake is normally open, the gear ring is released / movable, and the engine directly drives the vehicle, and the driving motor assists in driving the vehicle. When the extended-range hybrid system is in the energy recovery mode, the driving motor generates electricity and provides braking force.

[0023] Compared with the prior art, the beneficial effects of the present application are: The present application adopts the structure arrangement of single gear ring and double planetary row with brake, which is simple in structure and simple in control logic, so that the engine can be directly driven, the power is directly output, the transmission efficiency is high, and the vehicle can be driven with optimal fuel consumption when the extended-range hybrid device is running at high speed.

[0024] The present application utilizes the normally closed or normally open brake to control the fixing or movement of the gear ring (also called the inner gear ring), so that the extended-range hybrid transmission can be switched between pure electric driving, engine direct driving and hybrid driving, effectively solving the problems of high energy consumption and insufficient overtaking power of the existing extended-range device in high-speed running conditions. In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the following preferred embodiments are described in detail below, and the accompanying drawings are used for explanation. BRIEF DESCRIPTION OF DRAWINGS

[0025] The drawings accompanying the specification form a part of the present application and serve to provide further understanding of the present application, the exemplary embodiments of the present application and the explanations thereof serve to explain the present application, and do not constitute an improper limitation on the present application.

[0026] Figure 1 It is a schematic diagram of the extended-range hybrid system structure of the double planetary row structure in an embodiment; Figure 2 It is a schematic diagram of the system in the extended-range mode: the brake is normally closed, and the inner gear ring is in the fixed state in an embodiment; Figure 3 It is a schematic diagram of the system in the high-speed direct-drive mode: the brake is normally open, and the inner gear ring is in the movable state in an embodiment; Figure 4 It is a schematic diagram of the system in the high-speed overtaking mode: the brake is normally open, and the inner gear ring is in the movable state in an embodiment; Figure 5This is a schematic diagram of an embodiment where the system is in energy recovery mode: the brake is normally closed and the internal gear ring is fixed.

[0027] The components are as follows: 1. Engine; 2. Torsional damper; 3. Input shaft; 4. Generator; 5. First sun gear; 6. First planetary gear; 7. First planetary carrier; 8. Brake; 9. Battery pack; 10. Second planetary carrier; 11. Gear ring; 12. Second planetary gear; 13. Second sun gear; 14. Drive motor; 15. Output shaft; 16. Wheel end. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0029] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0030] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0031] Where there is no conflict, the embodiments and features described in this application may be combined with each other.

[0032] Example 1 A range-extended hybrid system, when applied to vehicles, such as Figure 1 As shown, it includes an engine 1, a torsional damper 2, an input shaft 3, an output shaft 15, a brake 8, a battery pack 9, and wheel ends 16. It also includes a generator 4, a drive motor 14, a first planetary gear set, a second planetary gear set, and a ring gear 11, wherein: The first planetary gear set includes a first planetary gear 6, a first sun gear 5, and a first planetary carrier 7. The first planetary carrier 7 is connected to the input shaft 3. The input shaft 3 is connected to the engine 1 through a torsional damper 2. The first planetary gear 6 is connected to the first planetary carrier 7, and the first sun gear 5 is connected to the first motor 4. The second planetary gear set includes a second planetary gear 12, a second sun gear 13, and a second planetary carrier 10. The second planetary carrier 10 is connected to the output shaft 15, the output shaft 15 is connected to the gear end 16, the second planetary gear 12 is connected to the second planetary carrier 10, and the second sun gear 13 is connected to the drive motor 14. The first planetary row and the second planetary row share a ring gear 11, the brake 8 is connected with the ring gear 11, and the brake 8 can be controlled to be always closed or always opened, so that the ring gear 11 is fixed or movable.

[0033] The combination of the engine 1, the generator 4, the drive motor 14, the ring gear 11 and the brake 8 can generate a plurality of different working modes, which are as follows: Low-speed and medium-speed range extending mode: as shown in FIG. 2, Figure 2 The brake 8 is always closed, the ring gear 11 is fixed, the torque of the engine 1 is transmitted to the first sun gear 5 through the input shaft 3 and the first planetary carrier 7 to drive the generator 4 to generate electricity, the electrical energy is stored in the battery pack 9 and is provided to the drive motor 14, the torque of the drive motor 14 is transmitted to the second planetary carrier 10 through the second sun gear 13 and the second planetary gear 12 connected thereto, and is output to the wheel end 16 through the output shaft 15. The speed of the wheel end 16 can be changed by adjusting the speed of the drive motor 14, without gear shifting, the vehicle runs stably, the riding comfort is improved, and the engine always works in the optimal energy consumption area, thereby effectively reducing the fuel consumption of the vehicle.

[0034] High-speed direct drive mode: as shown in FIG. 3, Figure 3 The brake 8 is always opened, the ring gear 11 is movable, the torque of the engine 1 is transmitted to the wheel end 16 through the input shaft 3, the first planetary carrier 7, the first planetary gear 6, the ring gear 11, the second planetary gear 12, the second planetary carrier 10 and the output shaft 15, and the generator 4 and the drive motor 14 are idling. The torque of the engine 1 is directly transmitted to the wheel end 15. In the high-speed running state of the vehicle, the engine directly drives the transmission with high efficiency, and the fuel economy is optimal.

[0035] High-speed overtaking mode: as shown in FIG. 4, Figure 4 The brake 8 is always opened, the ring gear 11 is movable, the torque of the engine 1 is transmitted to the wheel end 16 through the input shaft 3, the first planetary carrier 7, the first planetary gear 6, the ring gear 11, the second planetary gear 12, the second planetary carrier 10 and the output shaft 15, the torque of the drive motor 14 is transmitted to the second planetary carrier 10 through the second sun gear 13 and the second planetary gear 12 connected thereto, is coupled with the torque transmitted by the engine 1, is transmitted to the output shaft 13 and is output to the wheel end 16, and serves as auxiliary power to improve the overall torque and provide sufficient power for the vehicle to overtake at high speed.

[0036] Energy recovery mode: as shown in FIG. 5, Figure 5As shown, during the vehicle deceleration process, when the state of charge of the vehicle battery does not exceed the upper limit of the state of charge of the battery, the vehicle enters the energy recovery mode, and torque is transmitted from the wheel end 16, the output shaft 15, the second planet carrier 10, the second planet gear 12, and the second sun gear 13 to the drive motor 14, at which time the drive motor 14 generates electricity. On the one hand, the drive motor 14 can recover energy to reduce the energy consumption of the vehicle. On the other hand, the drive motor 14 can provide braking force to decelerate the vehicle.

[0037] In summary, the embodiment utilizes the normally closed or normally open brake, controls the fixed or movable inner ring gear, and can realize switching between pure electric driving, engine direct driving, and hybrid driving of the extended-range hybrid transmission, effectively solving the high energy consumption and insufficient overtaking power of the existing extended-range device in high-speed driving conditions.

[0038] Embodiment Two An extended-range hybrid vehicle includes the extended-range hybrid power system with a double planetary gear structure provided in Embodiment One.

[0039] The connection relationship between the parts, the connection relationship in each mode, and the working state can be referred to Embodiment One, and will not be described here.

[0040] Embodiment Three A control method for the vehicle provided in Embodiment Two, including the following steps: When the extended-range hybrid power system is in the extended-range mode, the brake is controlled to be normally closed, the ring gear is locked / fixed, and the engine only drives the generator to generate electricity. The electric energy generated by the generator is used to drive the motor to drive the vehicle. When the extended-range hybrid power system is in the direct driving mode, the brake is controlled to be normally open, the ring gear is released / movable, and the engine directly drives the vehicle. When the extended-range hybrid power system is in the overtaking mode, the brake is controlled to be normally open, the ring gear is released / movable, and the engine directly drives the vehicle, and the drive motor assists in driving the vehicle. When the extended-range hybrid power system is in the energy recovery mode, it should be noted that, in this embodiment, when the state of charge of the vehicle battery does not exceed the upper limit of the state of charge of the battery during the vehicle deceleration process, the vehicle enters the energy recovery mode. In this mode, the drive motor generates electricity and provides braking force.

[0041] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Those skilled in the art can make various modifications and changes to the present application without creative labor. Any modification, equivalent replacement, improvement, etc. made by those skilled in the art within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A range extended hybrid system comprising an engine, a brake, a generator, a drive motor, an input shaft, an output shaft, a first planetary set, a second planetary set, and a ring gear, wherein: The first planetary gear set comprises a first planetary gear, a first sun gear and a first carrier, and the second planetary gear set comprises a second planetary gear, a second sun gear and a second carrier; The first carrier is connected with the input shaft, the input shaft is connected with the engine, the first planetary gear is connected with the first carrier, and the first sun gear is connected with the generator; The second carrier is connected with the output shaft, the output shaft is used to be connected with a wheel end, the second planetary gear is connected with the second carrier, and the second sun gear is connected with the drive motor; The first planetary gear set and the second planetary gear set share a ring gear, and the brake is connected with the ring gear to lock or release the ring gear.

2. The extended-range hybrid system of claim 1, wherein the electric motor is configured to provide a torque of at least 100 Nm. A battery pack is arranged between the generator and the drive motor, and the battery pack is used to store the electric energy generated by the generator and provide electric energy for the drive motor.

3. The extended-range hybrid system of claim 1, wherein the electric motor is configured to provide a torque of at least 200 Nm. The first planetary gear is engaged with the first sun gear, and the second planetary gear is engaged with the second sun gear.

4. The extended-range hybrid system of claim 1, wherein the electric motor is configured to provide a torque of at least 200 Nm. The extended-range hybrid power system comprises a speed increasing mode, when the extended-range hybrid power system is in the mode, the brake is always closed, the ring gear is locked / fixed, the torque of the engine is transmitted to the first sun gear through the input shaft and the first carrier, the generator is driven to generate electricity, the electric energy is transmitted to the drive motor, the torque of the drive motor is transmitted to the second carrier through the second sun gear and the second planetary gear connected with the drive motor, and then transmitted to the wheel end through the output shaft.

5. The extended-range hybrid system of claim 1, wherein the electric motor is configured to provide a torque of at least 200 Nm. The extended-range hybrid power system comprises a direct drive mode, when the extended-range hybrid power system is in the mode, the brake is always open, the ring gear is released / movable, and the torque of the engine is transmitted to the wheel end through the input shaft, the first carrier, the first planetary gear, the ring gear, the second planetary gear, the second carrier and the output shaft.

6. The extended-range hybrid system of claim 1, wherein, The extended-range hybrid power system comprises an overtaking mode, when the extended-range hybrid power system is in the mode, the brake is always open, the ring gear is released / movable, the torque of the engine is transmitted to the wheel end through the input shaft, the first carrier, the first planetary gear, the ring gear, the second planetary gear, the second carrier and the output shaft, and the torque of the drive motor is transmitted to the second carrier through the second sun gear and the second planetary gear connected with the drive motor, and then transmitted to the wheel end through the output shaft after being coupled with the torque transmitted from the engine.

7. The extended-range hybrid system of claim 1, wherein the electric motor is configured to provide a torque of at least 200 Nm. The extended-range hybrid power system comprises an energy recovery mode, when the extended-range hybrid power system is in the mode, the torque is transmitted from the wheel end, the output shaft, the second carrier, the second planetary gear and the second sun gear to the drive motor, and the drive motor generates electricity at this time.

8. The extended-range hybrid system of claim 1, wherein, The input shaft and the output shaft are coaxially arranged. Alternatively, the input shaft is connected with the engine through a torsional damper.

9. A range extended hybrid vehicle, characterized by, An extended-range hybrid power system comprising the double planetary gear set structure according to any one of claims 1-8.

10. A control method for a vehicle based on the control method according to claim 9, characterized by The method comprises the following steps: When the extended-range hybrid power system is in the extended-range mode, the brake is controlled to be always closed, the ring gear is locked / fixed, the engine only drives the generator to generate electricity, and the electric energy generated by the generator is used to drive the drive motor to drive the vehicle; When the extended-range hybrid power system is in the direct drive mode, the brake is controlled to be always open, the ring gear is released / movable, and the engine directly drives the vehicle; When the extended-range hybrid system is in the overtaking mode, the control brake is always open, the ring gear is released / active, the engine directly drives the vehicle, and the drive motor assists in driving the vehicle; When the extended-range hybrid system is in the energy recovery mode, the drive motor generates electricity and provides braking force.

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