CN102658772A - Power system for hybrid electric automobile - Google Patents

Abstract

The invention discloses a power system of a hybrid electric vehicle. The output shaft of the engine is connected with a planetary frame, and non-fixed-axis planetary gears are arranged on the planetary frame. Installed coaxially with the transition gear, the transition gear meshes with the output gear, and the output gear is installed on the output shaft of the first motor; a second external gear is provided at the end of the ring gear, and the second external gear is connected to the first external gear The first external gear is installed on the output shaft of the second motor, and the drive gear of the reducer is also installed on the output shaft of the second motor, and the drive gear of the reducer is meshed with the driven gear of the reducer. The invention can effectively reduce the axial and radial dimensions, make the overall structure more compact and smaller in size, facilitate the arrangement in the front cabin of the automobile, expand the application range, and is also applicable to vehicles with small space in the front cabin.

Description

Hybrid Electric Vehicle Powertrain

technical field

The invention belongs to the technical field of electric vehicles, and in particular relates to a power system on a hybrid electric vehicle.

Background technique

Hybrid electric vehicle (hybrid electric vehicle, HEV) combines the characteristics of traditional vehicles and pure electric vehicles. It is currently recognized as the most practical and most likely to achieve marketable energy-saving vehicles. A typical model of a best-selling HEV.

As the power coupling mechanism of the hybrid HEV, the planetary gear mechanism of the third-generation Toyota Prius has the characteristics of multiple inputs and multiple outputs. Through the adjustment of the control strategy, it can realize independent driving of the engine, independent driving of the motor, joint driving of the engine and the motor, etc. The working mode realizes the best matching and intelligent switching of gasoline and electricity, and becomes the first choice of HEV power coupling mechanism.

The power coupler of the third-generation Toyota Prius is shown in Figure 2 (the dotted box in the figure), which consists of output gear 1, fixed-axis planetary gear 2, sun gear 3, non-fixed-axis planetary gear 4, ring gear 5, and An external gear 6, a reducer driving gear 7, a reducer driven gear 8, a second external gear 9 and a planetary carrier 10, etc., the output shaft of the engine ICE is connected to the planetary carrier 10, and the planetary carrier 10 is equipped with three circles. Evenly distributed non-fixed-axis planetary gears 4, each non-fixed-axis planetary gear 4 meshes with the sun gear 3 and the ring gear 5, and the sun gear 3 is installed on the output shaft of the first motor M1. There are also three fixed-axis planetary gears 2 meshed with it in the ring gear 5, and each fixed-axis planetary gear 2 is meshed with the output gear 1 of the second motor M2, and the output gear 1 is the sun gear of the fixed-axis planetary gear 2. . The outer circumference of the ring gear 5 is provided with a second external gear 9, which meshes with the first external gear 6 on the outside, and the drive gear 7 of the reducer is installed on the shaft of the first external gear 6. The drive gear 7 of the reducer meshes with the driven gear 8 of the reducer.

Since the three uniformly distributed gears 4 are non-fixed-axis planetary gears, the sun gear 3 , non-fixed-axis planetary gears 4 and ring gear 5 form a power distribution device. Since the three uniformly distributed gears 2 are fixed-axis planetary gears, the output gear 1 , fixed-axis planetary gears 2 and ring gear 5 form a deceleration and torque-increasing device for the second motor M2.

Then the relationship between the power distribution device motors M2, M1 and the engine speed is as follows:

n _M1 + i·p·n _M2 =(1+i)·n _ICE (1)

In the formula: n _M1 - the speed of the motor M1;

n _M2 - the speed of the motor M2;

i——the gear ratio of the inner gear of the ring gear 5 and the sun gear 3;

p——the gear ratio of the output gear 1 and the internal gear of the ring gear 5 (p<1);

n _ICE engine speed.

Part of the torque output by the engine acts on the motor M1 through the sun gear 3, and part of it acts on the ring gear 5. The torque distribution has the following relationship:

T _M1 = T _ICE /(1+i) (2)

T ₅ =i T _ICE /(1+i) (3)

In the formula: T _M1 - the torque of the engine output torque acting on the motor M1;

T ₅ ——the torque of the engine output torque acting on the ring gear 5;

T _ICE - the output torque of the engine.

The power system using the above-mentioned dynamic coupler has the following disadvantages:

1) The first motor M1 is located in the planet carrier, the first motor M1 and the second motor M2 are separated on both sides of the ring gear 5, and the first motor M1 is between the engine ICE and the second motor M2, so that the entire power system The large axial dimension of the vehicle is not conducive to the layout of the power system in the front cabin of the car, and will affect the range of use of the power system, especially for models with small space in the front cabin.

2) The deceleration and torque-increasing device of the second motor M2 adopts a planetary gear mechanism. The structure is relatively complicated, and the processing of parts is difficult, and the manufacturing and production are relatively difficult. the cost of.

3) The first external gear 6 is outside the circumference of the ring gear 5, and the radial size of the entire power system is relatively large, which makes it inconvenient to arrange the power system in the front cabin of the car, and also affects the range of use of the power system, especially for the front Not suitable for models with small cabin space.

4) There are 13 gears that need to be processed inside the power coupler, which will increase the production cost of the power system, and the connection of the power system is prone to interference, and the transmission efficiency and carrying capacity are poor.

Contents of the invention

The technical problem to be solved by the present invention is to provide a hybrid electric vehicle power system with compact structure and small space volume.

The technical solution of the present invention is as follows: a hybrid electric vehicle power system, including an engine (ICE), a first motor (M1), a second motor (M2), an output gear (1), a transition gear (2'), a sun wheel (3), non-fixed axis planetary gear (4), ring gear (5), first external gear (6), reducer driving gear (7), reducer driven gear (8), second external gear ( 9) and the planetary carrier (10), the output shaft of the engine (ICE) is connected to the planetary carrier (10), and the planetary carrier (10) is equipped with non-fixed-axis planetary gears (4) evenly distributed according to the circumference, and each non-fixed-axis The planetary gears (4) are meshed with the sun gear (3) and the ring gear (5), the sun gear (3) is installed coaxially with the transition gear (2'), and the transition gear (2') is located on the ring gear (5) The transition gear (2') meshes with the output gear (1), and the output gear (1) is installed on the output shaft of the first motor (M1); at the end of the ring gear (5) there is a second Two external gears (9), the second external gear (9) meshes with the first external gear (6), the first external gear (6) is installed on the output shaft of the second motor (M2), and the second motor (M2) and the first motor (M1) are located on the same side of the ring gear (5), and a reducer driving gear (7) is installed on the output shaft of the second motor (M2), and the reducer driving gear ( 7) Mesh with the reducer driven gear (8).

By adopting the above technical scheme, the sun gear, the non-fixed-axis planetary gear and the ring gear form the power distribution device, and the first external gear, the second external gear and the ring gear form the deceleration and torque increasing device of the second motor. In the present invention, the first motor is moved from the traditional position between the engine and the second motor to the side of the second motor, and the second motor and the first motor are located on the same side of the ring gear, and the first motor passes through the output gear and the transition gear. The meshing transmits the power to the sun gear, so that the engine can be moved to the direction of the second motor correspondingly without affecting the power transmission mode of the system, and accordingly the axial length of the entire power system can be reduced; at the end of the ring gear A second external gear is added, the second external gear meshes with the first external gear, and the first external gear and the driving gear of the reducer are coaxially installed, thereby reducing the radial size of the entire power system. Compared with the background technology, the axial and radial dimensions of the present invention are all reduced, the whole power system structure is more compact, the space volume is small, it is easy to arrange in the front cabin of the car, and the application range of the power system is increased, especially for It is also suitable for models with small front cabin space. At the same time, the present invention changes the deceleration and torque increasing device of the second motor from a traditional planetary gear mechanism to a common gear pair composed of two external gears. Conducive to maintenance and repair.

As a preference, three non-fixed-axis planetary wheels (4) evenly distributed on the circumference are installed on the planet carrier (10).

Preferably, the ring gear (5) and the second external gear (9) are integrally structured.

The beneficial effects of the present invention are:

1) It can effectively reduce the axial and radial dimensions, making the overall structure more compact and the space volume smaller, which is conducive to the arrangement in the front cabin of the car, and expands the scope of use, and is also applicable to models with small space in the front cabin.

2) By changing the transmission structure between the second motor and the ring gear into an ordinary gear pair, the processing technology of the parts is simplified, the difficulty of manufacturing and production is reduced, and the disassembly and assembly are convenient, and the maintenance and repair are convenient.

3) The output of the first motor is driven through the meshing transmission of the output gear and the transition gear (k<1). On the premise of not changing the output power of the entire power system, the selection of the first motor only needs to reasonably reduce the torque and increase the speed , for the motor, the requirement of reasonably reducing the torque and increasing the speed can reduce the difficulty of motor design and purchase cost, thereby indirectly reducing the cost of the entire powertrain, and at the same time reducing the weight and volume of the motor, thereby indirectly reducing the overall cost of the powertrain. cost, weight and volume.

4) There are 11 gears inside the power coupler. Compared with the background technology, one gear is saved and the total cost is reduced. At the same time, the connection of the power system will not cause interference, and the transmission efficiency is high and the carrying capacity is strong.

Description of drawings

Fig. 1 is a structural schematic diagram of the present invention.

Fig. 2 is a schematic structural diagram of the background technology.

Detailed ways

Below in conjunction with accompanying drawing and embodiment the present invention will be further described:

As shown in Figure 1, the present invention consists of engine ICE, first motor M1, second motor M2, output gear 1, transition gear 2', sun gear 3, non-fixed axis planetary gear 4, ring gear 5, first external gear 6. The drive gear 7 of the reducer, the driven gear 8 of the reducer, the second external gear 9 and the planetary carrier 10 are composed. Among them, the engine ICE is located on the leftmost side of the figure, the output shaft of the engine ICE is connected to the planet carrier 10, and the planet carrier 10 is located on the right side of the engine ICE, and the planet carrier 10 is equipped with three non-fixed-axis planets evenly distributed on the circumference The three non-fixed-axis planetary gears 4 are all located in the ring gear 5, and the three non-fixed-axis planetary gears 4 are meshed with the ring gear 5. A sun gear 3 is arranged in the middle of the three non-fixed-axis planetary gears 4 , and the sun gear 3 meshes with the three non-fixed-axis planetary gears 4 .

It can be seen from Fig. 1 that the sun gear 3 is coaxially installed with the transition gear 2', and the transition gear 2' is located on the right side of the ring gear 5, and the transition gear 2' meshes with the output gear 1, and the output gear 1 is installed on the first motor M1 on the output shaft. The right end of the ring gear 5 is integrally formed or assembled with a second external gear 9, the second external gear 9 meshes with the first external gear 6, and the gear ratio of the second gear 6 to the ring gear 5 is 1. The first external gear 6 is mounted on the output shaft of the second motor M2 , and both the second motor M2 and the first motor M1 are located on the right side of the ring gear 5 . On the output shaft of the second motor M2, a reducer driving gear 7 is also installed, and the reducer driving gear 7 is located on the right side of the first external gear 6, and the reducer driving gear 7 is meshed with the reducer driven gear 8 .

In the present invention, the sun gear 3, the non-fixed-axis planetary gear 4 and the ring gear 5 form the power distribution device, and the first external gear 6, the second external gear 9 and the ring gear 5 form the deceleration and torque increasing device of the second motor M2 .

The relationship between the power distribution device motors M2, M1 and the engine speed is as follows:

k·n _M1 +i·p·n _M2 =(1+i)·n _ICE (4)

In the formula: k—the gear ratio of output gear 1 and transition gear 2’ (k<1);

n _M1 - the speed of the first motor M1;

n _M2 - the speed of the second motor M2;

i——the gear ratio of the inner gear of the ring gear 5 and the sun gear 3;

p——the gear ratio between the first external gear 6 and the second external gear 9 (p<1);

n _ICE ——the speed of the engine.

Part of the torque output by the engine acts on the first motor M1 through the sun gear 3, and part of it acts on the ring gear 5. The torque distribution has the following relationship:

TM1=TICE/[k(1+i)] (5)

T5=i TICE/(1+i) (6)

In the formula: TM1—the torque of the engine output torque acting on the first motor M1;

T5—the torque of the engine output torque acting on the ring gear 5;

TICE - the output torque of the engine.

Claims (3)

1. A hybrid electric vehicle power system, including an engine (ICE), a first motor (M1), a second motor (M2), an output gear (1), a sun gear (3), a non-fixed-axis planetary gear (4 ), the ring gear (5), the first external gear (6), the driving gear of the reducer (7), the driven gear of the reducer (8) and the planetary carrier (10), the output shaft of the engine (ICE) and the planetary carrier ( 10) Connection, the planet carrier (10) is equipped with non-fixed-axis planetary gears (4) uniformly distributed on the circumference, and each non-fixed-axis planetary gear (4) is meshed with the sun gear (3) and the ring gear (5), It is characterized in that: the sun gear (3) is installed coaxially with the transition gear (2'), the transition gear (2') is located outside the ring gear (5), the transition gear (2') and the output gear (1) meshing, the output gear (1) is installed on the output shaft of the first motor (M1); a second external gear (9) is provided at the end of the ring gear (5), and the second external gear (9) and The first external gear (6) is meshed, the first external gear (6) is installed on the output shaft of the second motor (M2), and the second motor (M2) and the first motor (M1) are located on the ring gear (5) On the same side of the second motor (M2), a reducer driving gear (7) is installed on the output shaft of the second motor (M2), and the reducer driving gear (7) meshes with the reducer driven gear (8). 2. The hybrid electric vehicle power system according to claim 1, characterized in that: three non-fixed-axis planetary gears (4) evenly distributed on the circumference are installed on the planet carrier (10). 3. The hybrid electric vehicle power system according to claim 1 or 2, characterized in that: the ring gear (5) and the second external gear (9) are integrally structured.

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