CN103332108A - Two-gear power transmission system for BEV integrated planetary gear train - Google Patents

Abstract

The invention relates to a two-speed power transmission system of an integrated planetary gear train of a pure electric vehicle. Including drive motor, two-speed planetary gear transmission, shifting mechanism with synchronizer, differential, left half shaft and right half shaft, where the two-speed planetary gear transmission is composed of the first-stage planetary gear The planetary gear train is formed in series, the driving motor, the two-speed planetary gear transmission and the differential are integrated into one, and the axes of the driving motor, the two-speed planetary gear transmission and the differential are on the same straight line, through the belt synchronous The shift mechanism of the gear shifter realizes the smooth switching of low gear, high gear and neutral gear. The two-speed power transmission system of the integrated planetary gear train specially designed for pure electric vehicles of the present invention has unique design, compact structure and high transmission efficiency. , which is convenient for vehicle layout and light weight, and takes into account the requirements of vehicle power, economy and comfort, which is conducive to the promotion of industrialization.

Description

A two-speed power transmission system of an integrated planetary gear train for pure electric vehicles

technical field

The invention relates to a power transmission system of an electric vehicle, in particular to a two-speed power transmission system of an integrated planetary gear train of a pure electric vehicle, and belongs to the technical field of power transmission of electric vehicles.

Background technique

In order to solve the world's energy and environmental protection problems, the research and development of electric vehicles has become a hot spot in the development and research of the automobile industry. In view of the lack of unified design and layout of the main components of the pure electric vehicle power transmission system (drive motor, transmission and differential) during the research and development process, the power transmission system has a complex structure, bulky volume, increased weight, scattered systems, and high costs. Conducive to its development and industrialization, the integration of drive motors, transmissions, and differentials is an inevitable choice for the development of pure electric vehicles. At present, the integrated power transmission system of electric vehicles mostly adopts a parallel shaft output structure. This structure is simple to implement and the technology is mature, but the drive motor and transmission are set eccentrically with respect to the differential and the half shaft, which brings a great deal to the layout design of the power transmission system. difficulty. In addition, the current pure electric vehicles or automatic transmissions for fuel vehicles make the structure of the transmission system complex, increase the mass of the vehicle, and reduce energy utilization efficiency, or use a single fixed speed ratio reducer, so that the drive motor often works in the low efficiency area. The mileage of the vehicle is reduced, and it is difficult to balance the power and economy requirements of the vehicle. There is no integrated variable speed drive system suitable for pure electric vehicles.

Patent CN102616134A discloses an integrated drive device for pure electric vehicles, which integrates drive, deceleration and differential mechanisms, reduces volume and improves space utilization. The device adopts a double-planetary gear reduction mechanism with a fixed speed ratio, and it is difficult to balance the maximum vehicle speed and maximum gradient, as well as the requirements of power and economy.

Patent CN102555794A discloses a planetary gear train variable speed drive system for an electric vehicle, including a drive motor, a clutch, a planetary gear train speed change mechanism, a differential, a reduction gear transmission mechanism and wheels. The system drives the motor, planetary gear train transmission mechanism, and the main shaft of the differential are located on the same straight line parallel to the wheel axis, and two-speed transmission is realized through the different cooperation forms of the clutch driving disc and the two clutch driven discs. However, the planetary gear train transmission mechanism and reduction gear transmission mechanism of this system are separated, and have a parallel shaft structure, and the power transmission route is too long, which increases the complexity of the structure of the drive system itself and has a large size.

Patent CN102259588A discloses an integrated drive device for electric vehicles, which is composed of a transmission, a reducer, a differential, and a shared aluminum alloy casing and a shifting mechanism. A synchronizer is used to complete gear shifting, and the structure is simplified without a clutch. However, its speed change mechanism is a parallel shaft structure, which has a large external dimension, which brings inconvenience to the layout of the whole vehicle.

Therefore, in view of the difference in the characteristics of the drive motor and the fuel engine, it is necessary to provide an integrated two-speed power transmission system for pure electric vehicles, so that it can not only perform smooth shifts in due time according to vehicle conditions, road conditions and the driver's subjective wishes, but also It can keep the driving motor in a high-efficiency working area, and give full play to the advantages of electric vehicles in energy saving and environmental protection.

Contents of the invention

In order to solve the above defects or deficiencies in the prior art, the present invention provides a two-speed power transmission system of a pure electric vehicle integrated planetary gear train that integrates a drive motor, a two-speed planetary gear train transmission and a differential.

The present invention is achieved through the following technical solutions:

A two-speed power transmission system of a pure electric vehicle integrated planetary gear train of the present invention includes a drive motor, a transmission, a shift mechanism with a synchronizer, a differential, a left half shaft and a right half shaft, and an output shaft of the drive motor The output end extends to the outside of the motor housing; the differential includes a differential case, a planetary shaft, a differential planetary wheel, a left side gear, a right side gear, and between the left side gear and the right side gear Two differential planetary gears are respectively arranged through the planetary gear shafts, and the two ends of the planetary gear shafts are respectively arranged on the differential gear case.

The transmission of the present invention is a two-speed planetary gear transmission composed of a first-stage planetary gear train and a second-stage planetary gear train in series, and includes a cylindrical tubular transmission housing.

The output shaft of the drive motor is a hollow shaft, and a first-stage sun gear is fixed on the extended end of the output shaft, and a first-stage ring gear is provided corresponding to the first-stage sun gear. The first-stage gear The ring is set in one end of the transmission housing, and three first-stage planetary gears are arranged between the first-stage sun gear and the first-stage ring gear through the first-stage planet carrier; the first-stage sun gear, the first-stage ring gear , the first-stage planet carrier and three first-stage planetary gears constitute the first-stage planetary gear train; the three first-stage planetary wheels are located on one axial side of the first-stage planetary carrier, and the axial direction of the first-stage planetary carrier is on the other One side is the first tube shaft, the first tube shaft of the first-stage planet carrier is used as the output shaft of the first-stage planetary gear train, and the second-stage sun is arranged on the first tube shaft of the first-stage planet carrier through spline fit. There is a second-stage ring gear corresponding to the second-stage sun gear; three second-stage planetary gears are arranged between the second-stage sun gear and the second-stage ring gear through the second-stage planet carrier, and the second-stage sun gear Wheel, second-stage ring gear, second-stage planet carrier and three second-stage planetary gears constitute the second-stage planetary gear train; the first-stage planetary gear train and the second-stage planetary gear train are connected in series to form a two-speed planetary gear train transmission ;Three second-stage planetary gears are located on one axial side of the second-stage planet carrier, the other axial side of the second-stage planet carrier is the second tube axis, and the second tube axis of the second-stage planet carrier is the second The output shaft of the first-stage planetary gear train; the axial side of the second-stage ring gear is the third tube shaft, and the third tube shaft is sleeved on the second tube shaft of the second-stage planetary carrier, that is, the second The second tube shaft of the first-stage planetary carrier passes through the third tube shaft; the first-stage planetary gear train and the second-stage planetary gear train are both located in the transmission case, and one end of the transmission case corresponding to the first-stage ring gear is connected to the drive The end face of the casing of the motor and the other end of the transmission casing are provided with an end cover, and the third tube shaft and the second tube shaft both extend to the outside of the end cover; the first engagement ring gear is arranged on the end cover of the transmission case, and the second The two engaging ring gears are sleeved on the second tubular shaft through spline fit, and the synchronizer between the first engaging ring gear and the second engaging ring gear is sleeved on the third tubular shaft through spline fit, and the synchronizer It is a lock ring type inertial synchronizer, including a synchronous ring, an adapter sleeve, a slider and a spline hub; the third tube shaft of the second stage ring gear is connected to the spline hub through spline fit; it is equipped with a shift gear in conjunction with the synchronizer Shift fork; the second tube shaft of the second-stage planetary carrier outside the second engaging ring gear is connected to the differential case through a spline, and the left half shaft and the right half shaft are arranged in the differential case, and the left half shaft passes through The second tube shaft of the second-stage planetary carrier, the first tube shaft of the first-stage planetary carrier and the drive motor shaft are connected with the left wheel of the vehicle, the right half shaft is connected with the right side wheel of the vehicle, and the left half shaft and the right The half-shafts are coaxial, the left half-shaft gear is set on the left half-shaft, and the right half-shaft gear is set on the right half-shaft; the axis of the output shaft of the drive motor, the axis of the two-speed planetary gear transmission and the left half of the differential The axes of the axis and the right half axis are on the same straight line. the

The middle part of the transmission housing between the first-stage planetary gear train and the second-stage planetary gear train is radially provided with annular stiffeners to support the transmission components in the transmission.

The beneficial technical effects of the present invention are:

1. The present invention integrates the driving motor, the two-speed planetary gear transmission and the differential, and the axes of the driving motor, the two-speed planetary gear transmission and the differential are on the same straight line, separated from the power components Compared with the traditional power transmission system, it has high integration, short transmission line, small size and light weight, and is conducive to the design layout and lightweight of the whole vehicle;

2. The present invention adopts a two-speed planetary gear transmission mechanism, and realizes smooth switching between low gear, high gear and neutral gear through a gear shift mechanism with a synchronizer, eliminating the need for the main deceleration mechanism in a traditional automobile drive axle, with compact structure and light weight , The rotation is stable, compared with the electric vehicle transmission mechanism with a fixed speed ratio of the first gear, it can improve the power performance of the vehicle, the efficiency of the driving motor, the life of the power battery and prolong the mileage of the vehicle.

Description of drawings

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

Fig. 2 is a schematic diagram of the low gear (I gear) state of the present invention.

Fig. 3 is a schematic diagram of the high-grade (II gear) state of the present invention.

Fig. 4 is a schematic diagram of the neutral state of the present invention.

Serial numbers in the above picture: 1. Drive motor, 2. Output shaft, 3. First-stage sun gear, 4. First-stage planet carrier, 5. First-stage planetary gear, 6. First-stage ring gear, 7. First-stage 2nd stage sun gear, 8. 2nd stage planetary gear, 9. 2nd stage planet carrier, 10. 2nd stage ring gear, 11. 1st engagement ring gear, 12. Shift fork, 13. Synchronization ring, 14 .Joint sleeve, 15. Slider, 16. Spline hub, 17. Second joint ring gear, 18. Differential case, 19. Planetary gear shaft, 20. Differential planetary gear, 21. Right side shaft gear, 22. Right half shaft, 23. Left half shaft gear, 24. Left half shaft, 25. Transmission case.

Detailed ways

The present invention will be further described through the embodiments below in conjunction with the accompanying drawings.

Example

Referring to Fig. 1, a two-speed power transmission system of a pure electric vehicle integrated planetary gear train includes a drive motor 1, a two-speed planetary gear train transmission, a shift mechanism with a synchronizer, a differential, a left half shaft 24 and a right half shaft 24. Half shaft 22. The differential includes a differential case 18, a planetary gear shaft 19, a differential planetary gear 20, a left side gear 23, a right side gear 21, and a planetary shaft 19 is passed between the left side gear 23 and the right side gear 21. Two differential planetary wheels 20 are provided respectively, and the two ends of the planetary wheel shaft 19 are respectively arranged on the differential case 18 .

It can be seen from Figure 1 that the output shaft 2 of the drive motor 1 is a hollow shaft, and the output end of the output shaft 2 extends to the outside of the motor housing; The first-stage sun gear 3 is correspondingly provided with the first-stage ring gear 6, which is arranged in one end of the cylindrical tubular transmission housing 25, and the first-stage sun gear 3 and the first-stage ring gear 6 pass through The first-stage planet carrier 4 is equipped with three first-stage planetary gears 5; the first-stage sun gear 3, the first-stage ring gear 6, the first-stage planet carrier 4 and the three first-stage planetary gears 5 form the first stage planetary gear train. The three first-stage planetary gears 5 are located on one axial side of the first-stage planet carrier 4, and the other axial side of the first-stage planet carrier 4 is the first tube axis; the first tube axis of the first-stage planet carrier 4 As the output shaft of the first-stage planetary gear train, the second-stage sun gear 7 is installed on the first pipe shaft of the first-stage planet carrier 4 through spline fit; Ring 10; three second-stage planetary gears 8 are installed between the second-stage sun gear 7 and the second-stage ring gear 10 through the second-stage planet carrier 9, the second-stage sun gear 7, the second-stage ring gear 10, The second-stage planetary carrier 9 and three second-stage planetary gears 8 form a second-stage planetary gear train; the first-stage planetary gear train and the second-stage planetary gear train are connected in series to form a two-speed planetary gear train transmission. The three second-stage planetary gears 8 are located on one axial side of the second-stage planetary carrier 9, and the other axial side of the second-stage planetary carrier 9 is the second tube axis, and the second tube axis of the second-stage planetary carrier 9 As the output shaft of the second-stage planetary gear train; the axial side of the second-stage ring gear 10 is the third tube shaft, and the third tube shaft is sleeved on the second tube shaft of the second-stage planet carrier 9, that is, the first The second tube axis of the secondary planet carrier 9 passes through the third tube axis; both the first-stage planetary gear train and the second-stage planetary gear train are located in the transmission housing 25, and the transmission housing on the side of the first-stage ring gear 6 One end of 25 is connected to the casing end face of drive motor 1, and the other end of transmission housing 25 is equipped with an end cover, and the third tube shaft and the second tube shaft extend to the outside of the end cover; the first engagement ring gear 11 is arranged on the transmission On the end cover of the housing 25, the second engaging ring gear 17 is sleeved on the second tube shaft through a spline fit, and the synchronizer between the first engaging ring gear 11 and the second engaging ring gear 17 is sleeved through a spline fit On the third tube shaft, the synchronizer is a lock ring type inertia synchronizer, including a synchronization ring 13, an adapter sleeve 14, a slider 15 and a spline hub 16, and the third tube shaft of the second stage ring gear 10 passes through the spline The spline hub 16 is connected with the key fit; the shift fork 12 is installed in cooperation with the synchronizer; the second tube shaft of the second-stage planetary carrier 9 outside the second engagement ring gear 17 is connected to the differential case 18 through a spline ; Differential housing 18 is provided with left half shaft 24 and right half shaft 22, and left half shaft 24 passes through the second tube axis of second stage planet carrier 9, the first tube axis of first stage planet carrier 4 and the drive The output shaft 2 of the motor is connected with the left wheel of the vehicle, the right half shaft 22 is connected with the right side wheel of the vehicle, and the left half shaft 24 and the right half shaft 22 are coaxial, and the left half shaft gear 23 is installed on the left half shaft 24 , the right side shaft gear 21 is installed on the right side shaft 22; the axis of the output shaft 2 of the drive motor 1, the axis of the two-speed planetary gear transmission and the axes of the left side shaft 24 and the right side shaft 22 of the differential are at the same on a straight line.

The middle part of the transmission housing 25 between the first-stage planetary gear train and the second-stage planetary gear train is radially provided with annular stiffeners to support the transmission components in the transmission. the

The working principle of the present invention is as follows:

Taking the actual development of a two-speed power transmission system of a certain type of pure electric vehicle as an example, the two-speed power transmission system of a pure electric vehicle integrated planetary gear train of the present invention eliminates the need for clutches and drive axles in the traditional vehicle transmission system. The reduction mechanism, etc., the transmission ratio of the first gear is 10.2, and the transmission ratio of the second gear is 3.4. The number of teeth of each transmission gear of the two-speed planetary gear train transmission and the differential is shown in Table 1.

Table 1 Gear teeth table

When the drive motor 1 drives the first-stage sun gear 3 to rotate, the two-speed planetary gear transmission moves the engagement sleeve 14 through the shift fork 12, and under the joint action of the slider 15 and the synchronous ring 13, it is respectively connected with the first engagement gear. Ring gear 11 and the second engagement ring gear 17 are meshed to realize smooth switching between low gear, high gear and neutral gear, and transmit the power to the differential case 18 to drive the left half shaft 24 and right half shaft 22 to rotate, thereby driving the vehicle to achieve low speed Driving, highway driving, braking, reversing and trailer operation.

The working process of the two-speed power transmission system of a pure electric vehicle integrated planetary gear train of the present invention under low-speed driving, high-speed driving, braking, reversing and trailer driving is as follows:

1. When the vehicle starts and climbs at low speed, the two-speed power transmission system of the integrated planetary gear train is in the low gear (I) operating state. The shift fork 12 is used to move the engaging sleeve 14 to move to the first engaging ring gear 11 of the low gear, that is, the engaging sleeve 14 slides to the left to complete the shifting, as shown in FIG. 2 . The driving motor 1 outputs corresponding torque and rotating speed, and drives the vehicle through the two-speed planetary gear train transmission, the differential case 18, the left half shaft 24, and the right half shaft 22 to realize low-speed driving. Its power transmission path is:

Output shaft 2 of drive motor 1→first-stage sun gear 3→first-stage planet carrier 4→second-stage sun gear 7→second-stage planet carrier 9→differential case 18→left half shaft 24, right half shaft 22→Left and right wheels;

At this time, the second-stage ring gear 10 meshes with the first engaging ring gear 11 through the engaging sleeve 14 of the synchronizer. Because the first engaging ring gear 11 is fixedly connected to the end cover of the transmission housing 25 as a fixed piece, the second-stage ring gear 10 The rotation speed of the third tube shaft is zero, so the transmission ratio of the two-speed planetary gear transmission can be expressed as:

                            （1）

(1)

In the formula Z _a1 - the number of teeth of the first stage sun gear 3; Z _b1 - the number of teeth of the first stage ring gear 6; Z _a2 - the number of teeth of the second stage sun gear 7; Z _b2 - the number of teeth of the second stage ring gear 10;

2. When the vehicle is running at high speed, the two-speed power transmission system of the integrated planetary gear train is in the high-grade (II) operating state. The shift fork 12 is used to move the engaging sleeve 14 to move to the high-grade second engaging ring gear 17, that is, the engaging sleeve 14 slides to the right to complete gear shifting, as shown in FIG. 3 . The driving motor 1 outputs corresponding torque and rotating speed, and drives the vehicle through the two-speed planetary gear train transmission, the differential case 18, the left half shaft 24, and the right half shaft 22 to realize high-speed driving. Its power transmission path is:

Output shaft 2 of drive motor 1→first-stage sun gear 3→first-stage planet carrier 4→second-stage sun gear 7→second-stage planet carrier 9→differential case 18→left half shaft 24, right half shaft 22→Left and right wheels;

At this time, the second-stage ring gear 10 meshes with the second engaging ring gear 17 through the coupling sleeve 14 of the synchronizer, and the third tube shaft of the second-stage ring gear 10 and the second tube shaft of the second-stage planetary carrier 9 are locked and integrated Rotate and rotate synchronously with the first tube shaft of the first-stage planetary carrier 4, so the transmission ratio of the two-speed planetary gear train transmission at this time can be expressed as:

                         （2）

(2)

3. During braking energy recovery, the two-speed power transmission system of the integrated planetary gear train is in the low gear (I) operating state. The power transmission path is the same as the low-speed driving condition. As shown in Figure 2, the driving motor 1 is in the power generation state to realize energy recovery;

4. When reversing and driving at low speed, the two-speed power transmission system of the integrated planetary gear train is in the low-gear (I) operating state, as shown in Figure 2, at this time, the drive motor 1 reverses to realize the reverse driving of the vehicle;

5. When the vehicle breaks down and needs to be towed during operation, the drive motor 1 enters the free mode working state at this time. The gear shift fork 12 drives the adapter sleeve 14 to move axially to complete the separation of the neutral gear, so that each component is in an independent state, and the power is cut off to realize the trailer running in the neutral state, as shown in Figure 4 . the

Claims (2)

1. two shift power drive systems of a pure electric automobile integrated form planet circular system are united, and comprise gearshift, diff, left half axle and the right axle shaft of drive motor, change-speed box, tape synchronizer, and the mouth of the output shaft of drive motor extends the electric machine casing outside; Diff comprises differential gear box, planet wheel spindle, diff satellite gear, left half axle gear, right axle shaft gear, be respectively equipped with two diff satellite gears by planet wheel spindle between left half axle gear and the right axle shaft gear, the two ends of planet wheel spindle are located on the differential gear box respectively, it is characterized in that: described change-speed box is two grades of planet gear train speed changers that are made of first order planet circular system and the series connection of second stage planet circular system, comprises the case of transmission of cylindrical tube;

The output shaft of described drive motor is hollow shaft, be fixed with first order sun wheel on the overhanging end of described output shaft, the corresponding first order gear ring that is provided with first order sun wheel, described first order gear ring is located in the end of case of transmission, is provided with three first order satellite gears by the cooperation of first order pinion carrier between first order sun wheel and the first order gear ring; First order sun wheel, first order gear ring, first order pinion carrier and three first order satellite gears constitute first order planet circular system; Three first order satellite gears are positioned at an axial side of first order pinion carrier, the axial opposite side of first order pinion carrier is first tubular axis, first tubular axis of first order pinion carrier is provided with second stage sun wheel by spline fitted as the output shaft of first order planet circular system on first tubular axis of first order pinion carrier; The corresponding second stage gear ring that is provided with second stage sun wheel; Be provided with three second stage satellite gears by the cooperation of second stage pinion carrier between second stage sun wheel and the second stage gear ring, second stage sun wheel, second stage gear ring, second stage pinion carrier and three second stage satellite gears constitute second stage planet circular system; First order planet circular system and the series connection of second stage planet circular system constitute two grades of planet gear train speed changers; Three second stage satellite gears are positioned at an axial side of second stage pinion carrier, and the axial opposite side of second stage pinion carrier is second tubular axis, and second tubular axis of second stage pinion carrier is the output shaft of second stage planet circular system; An axial side of described second stage gear ring is the 3rd tubular axis, and described the 3rd pipe sleeve is located on second tubular axis of second stage pinion carrier, and namely second tubular axis of second stage pinion carrier passes the 3rd tubular axis; First order planet circular system and second stage planet circular system all are positioned at case of transmission, one end of the case of transmission corresponding with first order gear ring is connecting the casing end face of drive motor, the other end of case of transmission is provided with end cap, and described the 3rd tubular axis and second tubular axis all extend the end cap outside; First engages gear ring is located on the case of transmission end cap, second engages gear ring is set on second tubular axis by spline fitted, first synchro that engages between gear ring and the second joint gear ring is set on the 3rd tubular axis by spline fitted, described synchro is lock ring type inertia synchronizer, comprises baulk ring, sliding hub, slide block and splined hub; The 3rd tubular axis of second stage gear ring is connecting splined hub by spline fitted; Cooperate with synchro and to be provided with control fork; Second second tubular axis that engages the second stage pinion carrier in the gear ring outside is connecting differential gear box by spline, be provided with left half axle and right axle shaft in the differential gear box, left half axle passes second tubular axis of second stage pinion carrier, first tubular axis and the drive motor axle of first order pinion carrier, and be connected with the vehicle left side wheel, right axle shaft is connected with the vehicle right side wheels, and left half axle and right axle shaft are coaxial, and left half axle gear is located on the left half axle, and the right axle shaft gear is located on the right axle shaft; The axis of the axis of the axis of the output shaft of drive motor, two grades of planet gear train speed changers and the left half axle of diff and right axle shaft is on same straight line.

2. two shift power drive systems of a kind of pure electric automobile integrated form planet circular system according to claim 1 are united, it is characterized in that: the case of transmission middle part between first order planet circular system and the second stage planet circular system radially is provided with the reinforcement gusset of ring-type, to support the drive disk assembly in the change-speed box.

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