Vehicle hybrid power driving system

Abstract

The invention discloses a vehicle hybrid power driving system which comprises an engine, two motors, a planet row mechanism, a reduction gear and a differential mechanism. The planet row mechanism comprises a first planet row and a second planet row, and an inner gear ring and a planet carrier of each planet row are connected with each other to form a four-axis planetary gear train. The engine is connected with a sun gear of the first planet row, the generator is connected with an inner gear ring of the first planet row, and a sun gear of the second planet row serves as a power output shaft and is connected with the driving motor. When the engine works, the power system achieves a power split driving mode, the stepless speed change function of the whole vehicle is achieved through control of the double motors, and the engine is not affected by running working conditions to the maximum extent and works in a low-oil-consumption interval. The scheme can be used for front-drive and rear-drive vehicles, and can be used for deep hybrid power and plug-in hybrid power vehicles. The energy conversion efficiency is improved, and the reliability of motor operation is enhanced.

Description

Technical Field

[0001] The present invention belongs to the technical field of vehicle power transmission, and in particular relates to a vehicle hybrid power drive system, which can be used as an electromechanical coupling electric drive transmission device of a hybrid vehicle. Background Art

[0002] In order to cope with energy issues and environmental pressure, the electrification of automobile power systems has become a development trend. Hybrid electric vehicle technology is mature and can effectively reduce automobile fuel consumption, especially in urban conditions. Currently, the more mature hybrid technology routes include power split system and series-parallel system.

[0003] In the early days, many domestic automobile companies added motors to existing gearboxes to achieve electrification. This type of product adds the cost of motors and controllers on top of the cost of existing gearboxes. Currently, dedicated hybrid boxes have technical solutions including series-range extender, series-parallel and power split hybrid solutions. In the series-range extender solution, the engine does not directly participate in driving the vehicle, but is only used for power generation. It is generally used as a battery feed when it is open. The power undergoes two energy conversions with poor efficiency, making it difficult to use in non-plug-in vehicles. The series-parallel hybrid solution requires a clutch unit to control the engine to participate in driving the vehicle, and the engine's participation in the work is also subject to the speed of the vehicle. When driving at low speeds, the entire vehicle can only be driven by the drive motor alone, which has high requirements for the performance of the drive motor and increases costs. Summary of the invention

[0004] The purpose of the present invention is to address the defects of the above-mentioned existing vehicle power systems and to provide a vehicle hybrid drive system that adopts a power-split hybrid technology route, eliminates shifting elements, has a small number of parts, can be adapted to vehicles of different levels, and can be used for deep hybrid vehicles and plug-in hybrid vehicles. It can also be used for transverse front-wheel drive vehicles and rear-wheel drive vehicles, thereby improving energy conversion efficiency and enhancing the reliability of motor operation.

[0005] Technical Solution

[0006] In order to achieve the above purpose, the following technical solutions are proposed:

[0007] A vehicle hybrid drive system adopts a double planetary gear mechanism as a power coupling mechanism, integrating an engine, a double planetary gear mechanism, a generator, a drive motor and a reduction gear; the double planetary gear mechanism includes a first planetary gear and a second planetary gear, the first planetary gear includes a first sun gear, a first planetary gear, a first planetary carrier and a first inner gear ring, the second planetary gear includes a second sun gear, a second planetary gear, a second planetary carrier and a second inner gear ring; the first sun gear is meshed with the first planetary gear, the first planetary gear is meshed with the first inner gear ring, the first planetary gear is installed on the first planetary carrier and can rotate and revolve around the first sun gear, the first planetary carrier A plurality of first planetary gears are arranged on the circumference, the second sun gear is meshed with the second planetary gears, the second planetary gears are meshed with the second inner gear ring, the second planetary gears are mounted on the second planet carrier and can rotate and revolve around the second sun gear, a plurality of second planetary gears are arranged on the circumference of the second planet carrier, the first inner gear ring is connected with the second inner gear ring, the first inner gear ring and the second inner gear ring are simultaneously connected to the generator rotor shaft directly or through gear transmission, the first planet carrier is connected to the second planet carrier, the first sun gear is connected to the engine through the input shaft, the second sun gear is connected to the output shaft, and the drive motor rotor shaft is connected to the output shaft through gear transmission.

[0008] Furthermore, a first reduction gear is installed on the output shaft, the first reduction gear is meshed with a second reduction gear on the intermediate shaft, a third reduction gear is installed on the rotor shaft of the driving motor, the third reduction gear is meshed with the second reduction gear, a fourth reduction gear is installed on the intermediate shaft, the fourth reduction gear is meshed with a differential reduction gear, and power is output through the differential to drive the vehicle to travel. At the same time, the second reduction gear and the fourth reduction gear are an integrated structure.

[0009] For a longitudinal rear-wheel drive vehicle, a first reduction gear is installed on the output shaft, a third reduction gear is installed on the drive motor rotor shaft, and the third reduction gear is meshed with the first reduction gear. The third reduction gear installed on the drive motor rotor shaft is directly meshed with the first reduction gear, and the output shaft is directly connected to the vehicle chassis main reduction gear.

[0010] In pure electric drive, the drive motor is used to drive the vehicle alone. At this time, the generator is in idling state and the engine relies on its own friction resistance to maintain zero speed.

[0011] The engine starts and enters the hybrid drive mode, and the power system operates in the power split mode. This working mode can decouple the engine speed from the vehicle speed, that is, the engine working range is not affected by the driving conditions, and the engine can work in the optimal fuel consumption range for a long time. It can also achieve stepless speed change of the whole vehicle through motor control, that is, the E-CVT function. According to the planetary gear ratio design, the generator will output a torque opposite to that of the engine to maintain the torque balance of the planetary gear train. The generator is in the power generation state, that is, a part of the mechanical power output by the engine is converted into electrical power, which can be supplied to the drive motor and converted into mechanical energy again to drive the vehicle. The power split hybrid system can make the engine work stably in a low fuel consumption range, which is beneficial overall.

[0012] Beneficial effects:

[0013] The present invention provides a vehicle hybrid drive system, which uses a double planetary gear mechanism as a power coupling mechanism, and realizes a power splitting working mode through the connection combination between the engine, the generator, the drive motor and the output and the planetary gear elements. The hybrid transmission system does not use a shift clutch and a brake, and relies on the characteristics of the planetary gear train to achieve stepless speed change by controlling the motor, has high reliability, and is suitable for strong hybrid and plug-in hybrid. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Attached Figure 1 is a schematic diagram of the connection relationship in Example 1 of the present invention;

[0015] Attached Figure 2 is a schematic diagram of the connection relationship in Embodiment 2 of the present invention;

[0016] Attached Figure 3 It is the equivalent lever model of the planetary gear train in Example 1 of the present invention. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0018] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it may be directly on the other component or there may also be a central component. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may be a central component at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in the specification of this application are for illustrative purposes only and do not represent the only implementation method.

[0019] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0020] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first feature is directly in contact with the second feature, or the first feature and the second feature are indirectly in contact through an intermediate medium. Moreover, a first feature being “above”, “above” or “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below” or “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0021] Unless otherwise defined, all technical and scientific terms used in the specification of this application have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in the specification of this application includes any and all combinations of one or more related listed items.

[0022] Example 1

[0023] like Figure 1 As shown, a vehicle hybrid drive system is used for a front-wheel drive vehicle, including an engine, a dual planetary gear mechanism, a generator, a drive motor, a reduction gear, a differential and other components.

[0024] The double planetary row mechanism includes a first planetary row and a second planetary row. The first planetary row includes a first sun gear 3, a first planetary gear 4, a first inner gear ring 5, and a first planet carrier 6. The first planetary gear 4 is meshed with the first sun gear 3 and the first inner gear ring 5 at the same time. The first planetary gear 4 is mounted on the first planet carrier 6 and can rotate and revolve around the first sun gear 3. A plurality of first planetary gears 4 are arranged on the circumference of the first planet carrier 6. The second planetary row includes a second sun gear 8, a second planetary gear 9, a second planet carrier 7, and a second inner gear ring 10. The second sun gear 8 is meshed with the second planetary gear 9. The second planetary gear 9 is meshed with the second inner gear ring 10 at the same time. The second planetary gear 9 is mounted on the second planet carrier 7 and can rotate and revolve around the second sun gear 8. A plurality of second planetary gears 9 are arranged on the circumference of the second planet carrier 7. The first inner gear ring 5 and the second inner gear ring 10 are connected and are directly connected to the generator rotor shaft 16 at the same time. The first planet carrier 6 is connected to the second planet carrier 7. The first sun gear 3 is connected to the engine through the input shaft 1, and the second sun gear 8 is connected to the output shaft 2. A first reduction gear 11 is installed on the output shaft 2, and the first reduction gear 11 is meshed with the second reduction gear 12 on the intermediate shaft 13. A third reduction gear 22 is installed on the drive motor rotor shaft 21, and the third reduction gear 22 is meshed with the second reduction gear 12. A fourth reduction gear 14 is also installed on the intermediate shaft 13. The second reduction gear 12 and the fourth reduction gear 14 are an integrated structure, and the fourth reduction gear 14 is meshed with the differential reduction gear 15. Power is output to the half-axles through the differential 24 to drive the wheels to rotate.

[0025] According to the connection relationship between the first planetary gear and the second planetary gear, the two inner gear rings are connected and the two planet carriers are connected together, so a four-axis planetary gear system can be obtained. The speed ratio of the first planetary gear is designed to be smaller than the speed ratio of the second planetary gear, that is, (ZR1 / ZS1)<(ZR2 / ZS2), ZR1 represents the number of teeth of the first inner gear ring 5, ZS1 represents the number of teeth of the first sun gear 3, ZR2 represents the number of teeth of the second inner gear ring 10, and ZS2 represents the number of teeth of the second sun gear 8. Therefore, the following is obtained Figure 3 The equivalent lever model shown in FIG. Among them, R1 is the first inner gear ring 5, PC1 is the first planet carrier 6, S1 is the first sun gear 3, R2 is the second inner gear ring 10, PC2 is the second planet carrier 7, and S2 is the second sun gear 8.

[0026] It can be seen from the equivalent lever model of the planetary gear train that the two inner gear rings and the two planet carriers are connected to each other to form an axis. The original gear train with two planetary rows and a total of six axes is connected to a four-axis gear train through component connection. The engine is connected to the S1 axis represented by the first sun gear 3, the generator is connected to the R1 R2 axis formed by the first inner gear ring 5 and the second inner gear ring 10, and the drive motor is connected to the output shaft 2 through gears, which is equivalent to being connected to the S2 axis represented by the second sun gear 8 in the lever model. The four-axis planetary gear train satisfies a speed equation, that is, as long as the speed of two of the shafts is known, the speed of the remaining shafts can be calculated. When the shaft connected to the engine is stable at a low fuel consumption speed, the speed of the remaining shafts of the planetary gear train can be changed. One of the shafts is connected to the output end to change the vehicle speed, and the other shaft is connected to the generator. By controlling the generator, the optimal engine operating point can be adjusted under different vehicle conditions to reduce the fuel consumption of the whole vehicle.

[0027] When driving purely electric, the drive motor alone drives the vehicle. At this time, the generator is in idling state, and the engine relies on its own friction resistance to maintain zero speed.

[0028] When the vehicle switches from pure electric driving to hybrid driving, the generator quickly pulls the engine to the ignition speed, and the engine starts in power split mode. At this time, the engine can operate in a low fuel consumption range without being restricted by driving conditions. The generator must output torque opposite to that of the engine to maintain the torque balance of the planetary gear train. At this time, the torque output by the generator depends on the engine torque.

[0029] Where, i1=ZR1 / ZS1, i2=ZR2 / ZR2

[0030] The engine can only output driving torque, which is stipulated as positive torque and positive speed. At this time, the generator is in a positive speed and negative torque state, and the output electric power is supplied to the drive motor or input into the battery for short-term storage. At low speed, the drive motor provides the main driving torque and brake energy recovery for the whole vehicle. When driving at high speed, the driving torque of the whole vehicle is small. At this time, the drive motor outputs a small torque to maintain a relatively small electric power state. The whole system is in a state of power balance, and the battery is in a state of neither charging nor discharging. Reducing the size of the electric power and allowing the power required by the whole vehicle to be transmitted through a mechanical path can improve the overall transmission efficiency of the system and reduce fuel consumption.

[0031] Example 2

[0032] This embodiment is a hybrid power system for rear-wheel drive vehicles, especially urban public transportation vehicles, urban logistics vehicles, etc.

[0033] like Figure 2As shown, the third reduction gear 22 mounted on the drive motor rotor shaft 21 is directly meshed with the first reduction gear 11, and the first reduction gear 11 is mounted on the output shaft 2. The fifth reduction gear 26 is mounted on the generator rotor shaft 16, and the sixth reduction gear 25 is coaxially mounted on the inner gear ring shaft, and the sixth reduction gear 25 is meshed with the fifth reduction gear 26. The output shaft 2 is directly connected to the vehicle chassis main reduction. The working principle of the entire power system is the same as that of embodiment 1, except that the structural layout is adjusted to better adapt to the rear-drive vehicle.

[0034] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0035] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A vehicle hybrid drive system, characterized in that: It comprises an engine, a double planetary gear mechanism, a generator, a driving motor and a reduction gear; the double planetary gear mechanism comprises a first planetary gear and a second planetary gear, the first planetary gear comprises a first sun gear (3), a first planetary gear (4), a first planetary carrier (6) and a first inner gear ring (5), the second planetary gear comprises a second sun gear (8), a second planetary gear (9), a second planetary carrier (7) and a second inner gear ring (10); the first sun gear (3) is meshed with the first planetary gear (4), the first planetary gear (4) is meshed with the first inner gear ring (5), the first planetary gear (4) is mounted on the first planetary carrier (6) and can rotate and revolve around the first sun gear (3), a plurality of first planetary gears (4) are arranged on the circumference of the first planetary carrier (6), and the second sun gear (8) is meshed with the first planetary gear (4). The second planetary gear (9) is meshed with the second planetary gear (9), the second planetary gear (9) is meshed with the second inner gear ring (10), the second planetary gear (9) is mounted on the second planetary carrier (7) and can rotate and revolve around the second sun gear (8), a plurality of second planetary gears (9) are arranged on the circumference of the second planetary carrier (7), the first inner gear ring (5) is connected with the second inner gear ring (10), the first inner gear ring (5) and the second inner gear ring (10) are simultaneously directly or through gear transmission connected to the generator rotor shaft (16), the first planetary carrier (6) is connected with the second planetary carrier (7), the first sun gear (3) is connected to the engine through the input shaft (1), the second sun gear (8) is connected to the output shaft (2), and the drive motor rotor shaft (21) is connected to the output shaft (2) through gear transmission.

2. A vehicle hybrid drive system according to claim 1, characterized in that: The output shaft (2) is provided with a first reduction gear (11), the first reduction gear (11) is meshed with a second reduction gear (12) on an intermediate shaft (13), the drive motor rotor shaft (21) is provided with a third reduction gear (22), the third reduction gear (22) is meshed with the second reduction gear (12), the intermediate shaft (13) is provided with a fourth reduction gear (14), the fourth reduction gear (14) is meshed with a differential reduction gear (15), and power is output through the differential (24).

3. A vehicle hybrid drive system according to claim 1, characterized in that: A first reduction gear (11) is mounted on the output shaft (2), a third reduction gear (22) is mounted on the drive motor rotor shaft (21), and the third reduction gear (22) is meshed with the first reduction gear (11).

4. A vehicle hybrid drive system according to claim 2, characterized in that: The second reduction gear (12) and the fourth reduction gear (14) are of an integrated structure.

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