CN109203986B - Two-speed electric drive transmission device - Google Patents

Abstract

The present invention discloses a two-speed electric drive transmission device, including a motor, a planetary gear mechanism, a reduction gear, a differential, and a shift element. By controlling the shift element, a pure electric drive mode, a series working mode, and a parallel driving mode of two gears can be realized, and the device can be used for pure electric vehicles, plug-in hybrid vehicles, and extended-range electric vehicles, meeting the requirements of different vehicle platforms. The transmission device adopts a new planetary gear mechanism to reduce the difficulty of processing, and has two pure electric working gears, which can reduce the performance requirements of the motor and improve the performance of the vehicle.

Description

Two-speed electric drive transmission device

Technical Field

The invention patent relates to the field of vehicle power transmission technology, especially a two-speed electric drive transmission device for pure electric and extended-range electric vehicles.

Background technique

The electrification of automobile power systems has become a development trend. Multi-speed electric drive transmission devices can improve vehicle performance and optimize the working range of the drive motor, reduce battery consumption, and become a feasible solution to improve the performance of electric drive systems at this stage.

At present, most pure electric and extended-range solutions use a fixed speed ratio mode when driving in pure electric mode, which results in the motor working state being completely dependent on the driving road conditions and the system efficiency cannot be optimized. Therefore, the development of two-gear or multi-gear electric drive transmission devices has a promising market prospect.

Summary of the invention

The purpose of the patent of this invention is to provide a two-speed electric drive transmission device, which can not only meet the vehicle speed and power requirements in pure electric mode, but also serve as the driving part of the extended-range power system, relying on the engine to complete the cruising range when the battery power is insufficient.

In order to achieve the above-mentioned invention object, the following technical solution is proposed:

A two-speed electric drive transmission device, characterized in that:

The planetary gear mechanism includes a first sun gear, a first planetary gear, a second planetary gear, a second sun gear and a planet carrier. The first sun gear is meshed with the first planetary gear, the first planetary gear is meshed with the second planetary gear to form a planetary gear pair, and the second planetary gear is meshed with the second sun gear at the same time. A plurality of pairs of planetary gear pairs are arranged on the circumference of the planet carrier, that is, the first sun gear is meshed with a plurality of first planetary gears at the same time, and the second sun gear is meshed with a plurality of second planetary gears at the same time. The first sun gear is mounted on the second shaft, and a first brake is arranged between the second shaft and the transmission housing. When the first brake is closed, the second shaft will be locked to zero speed. The second sun gear is mounted on the first shaft, and the first shaft is connected to the rotor of the drive motor at the same time. The planet carrier serves as a power output shaft.

For longitudinal rear-wheel drive vehicles, the planetary carrier can be directly connected to the vehicle's main reducer flange or connected to a reduction mechanism with a fixed speed ratio and then connected to the vehicle's main reducer flange.

For transverse front-wheel drive vehicles, a reduction gear is installed on the planetary carrier, and the power is transmitted to the differential through the reduction gear, and then the vehicle is driven through the half shaft. The reduction gear adopts a two-stage reduction, including the small reduction gear on the planetary carrier meshing with the large reduction gear on the gear coupling to form the first stage of reduction; the small reduction gear on the gear coupling meshes with the differential main reduction large gear to form the second stage of reduction.

The first brake may be a friction plate brake or a mechanical mechanism with a rotation locking function. A first clutch is arranged between the first shaft and the second shaft. The first clutch adopts a friction plate clutch mechanism. When the first clutch is closed, the first shaft and the second shaft will run at the same speed. The first clutch realizes the overall rotation of the planetary gear mechanism, and can also be arranged between the first sun gear and the planet carrier or between the second sun gear and the planet carrier.

In pure electric driving, the first brake is closed and the first clutch is open. At this time, the gear ratio is designed to obtain a large driving torque for accelerating starting and climbing conditions. This gear is the first gear pure electric mode. As the vehicle speed increases, the speed of the drive motor increases, the first brake is opened, and the first clutch is closed. At this time, the planetary gear mechanism rotates as a whole, and there is no meshing movement between the components. This is defined as the second gear pure electric mode.

A reduction gear 1 is fixedly mounted on the first shaft, a reduction gear 3 is placed on the transmission shaft, and the reduction gear 3 can rotate freely on the transmission shaft. A reduction gear 2 is placed between the reduction gear 1 and the reduction gear 3, and the reduction gear 2 is meshed with the reduction gear 1 and the reduction gear 3 at the same time; a second clutch is arranged between the transmission shaft and the reduction gear 3. The transmission shaft serves as the input shaft of the engine power, and the fixed gear on the transmission shaft meshes with the gear on the generator shaft, and the generator shaft is connected to the rotor of the generator. When the second clutch is closed, the engine and the drive motor can drive the vehicle together.

Beneficial Effects

The present invention provides a two-speed electric drive transmission device, which adopts a planetary mechanism composed of cylindrical external gears, is easy to process and manufacture, and reduces the difficulty of product development. The two-speed drive can take into account both the requirements of low-speed high torque and high-speed driving, reduce the performance requirements of the motor, and at the same time help improve the efficiency of the power system and extend the driving mileage.

The transmission is a platform-based technical solution that can also be used in extended-range electric systems and series-parallel hybrid systems.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of a two-speed pure electric system solution in Embodiment 1 of the present invention;

FIG2 is a schematic diagram of an extended-range electric system solution in Embodiment 2 of the present invention;

FIG3 is a schematic diagram of a series-parallel hybrid system solution in Embodiment 3 of the present invention.

Detailed ways

The present invention is further described in detail below with reference to the accompanying drawings and embodiments.

Example 1

As shown in FIG. 1 , a two-speed electric drive transmission device includes a drive motor TM, a planetary gear mechanism, a reduction gear, a differential, a clutch, and a brake element.

The planetary gear mechanism comprises a first sun gear 3, a first planetary gear 5, a second planetary gear 6, a second sun gear 4 and a planet carrier 7. The first sun gear 3 is meshed with the first planetary gear 5, the first planetary gear 5 is meshed with the second planetary gear 6 and forms a planetary gear pair, the second planetary gear 6 is meshed with the second sun gear 4 at the same time, and a plurality of pairs of planetary gear pairs are arranged on the circumference of the planet carrier 7. The first sun gear 3 is mounted on the second shaft 2, and a first brake B1 is arranged between the second shaft 2 and the transmission housing 0. When the first brake B1 is closed, the second shaft 2 will be locked to zero speed. The first brake B1 adopts a one-way clutch mechanism with a speed limiting function to limit the rotation direction of the second shaft 2 under the control of the operating mechanism. The second sun gear 4 is mounted on the first shaft 1, and the first shaft 1 is connected to the rotor 14 of the drive motor TM at the same time, and the planet carrier 7 serves as a power output shaft. The stator 15 of the drive motor TM is fixed on the transmission housing. The small reduction gear 8 mounted on the planet carrier 7 meshes with the large reduction gear 9 on the gear coupling 11 to form the first stage of reduction; the small reduction gear 10 on the gear coupling 11 meshes with the differential main reduction large gear 12 to form the second stage of reduction. The power is transmitted to the differential 25 through the two-stage reduction gears, and then drives the vehicle through the half shaft 13.

A first clutch C1 is arranged between the first shaft 1 and the second shaft 2. The first clutch C1 adopts a friction plate clutch mechanism. When the first clutch C1 is closed, the first shaft 1 and the second shaft 2 will run at the same speed.

The control logic relationship between each working mode and the shifting elements is shown in the following table.

Operating mode B1 C1 EV-1 ● ○ EV-2 ○ ●

Note: ０-open state; ●-closed state.

At low vehicle speeds, the first brake B1 is closed alone, and the first sun gear 3 is locked at zero speed, serving as the first gear pure electric mode EV-1.

When the vehicle speed increases, the speed of the drive motor TM increases accordingly, the first brake B1 is opened and the first clutch C1 is closed. At this time, the components of the planetary gear mechanism rotate as a whole, and there is no relative meshing between the components, which serves as the second gear pure electric mode EV-2.

Example 2

As shown in FIG2 , a range extender unit is added on the basis of Example 1 to form an extended-range electric drive system. The range extender drive unit includes an engine ICE, a generator ISG and a transmission mechanism. The engine ICE is connected to a transmission shaft 21 through a flywheel damper FW. A fixed gear 19 is installed on the transmission shaft 21. The fixed gear 19 is meshed with a gear 20 installed on a generator shaft 22. The generator shaft 22 is connected to a rotor 23 of the generator ISG. The stator 24 of the generator ISG is fixed to the transmission housing. The fixed gear 19 and the gear 20 are used to increase the rotation speed of the generator ISG and improve the working efficiency of the generator ISG.

When the battery is fully charged, the drive motor TM drives the vehicle in two-speed pure electric mode, and the engine ICE and generator ISG do not work. When the battery is low, the engine starts to drive the generator ISG to generate electricity, providing power for the battery or drive motor TM. This is equivalent to a series working mode, and the engine does not directly participate in the drive, so the engine can work in a stable state and only drive the generator ISG to generate electricity.

Example 3

On the basis of Example 2, a reduction gear and a clutch unit are added in which the engine directly participates in the driving. Under certain working conditions, the engine ICE can directly drive the vehicle. The transmission structure is shown in FIG3 .

A reduction gear 16 is fixedly mounted on the first shaft 1, a reduction gear 3 18 is placed on the transmission shaft 21, and the reduction gear 3 18 can rotate freely on the transmission shaft 21. A reduction gear 2 17 is placed between the reduction gear 1 16 and the reduction gear 3 18, and the reduction gear 2 17 is meshed with the reduction gear 1 16 and the reduction gear 3 18 at the same time. A second clutch C2 is arranged between the transmission shaft 21 and the reduction gear 3 18.

In addition to being able to realize two-speed pure electric and series working modes, the transmission device can also operate in a low fuel consumption area when the vehicle speed is relatively high, closing the second clutch C2, and the engine power is transmitted to the first shaft 1 through the reduction gear three 18, the reduction gear two 17, and the reduction gear one 16, and the vehicle is driven in two-speed mode. The control logic relationship between each working mode and the shifting element is shown in the following table.

Operating mode B1 C1 C2 EV-1 ● ○ ○ EV-2 ○ ● ○ Series-1 ● ○ ○ Tandem-2 ○ ● ○ Parallel-1 ● ○ ● Parallel-2 ○ ● ●

Note: ０-open state ●-closed state

Claims (5)

1. The utility model provides a two grades of electric drive transmission, it includes planetary gear mechanism, characterized in that: the planetary gear mechanism comprises a first sun gear (3), a first planet gear (5), a second planet gear (6), a second sun gear (4) and a planet carrier (7), wherein the first sun gear (3) is meshed with the first planet gear (5), the first planet gear (5) is meshed with the second planet gear (6) to form a planetary gear pair, the second planet gear (6) is meshed with the second sun gear (4) at the same time, a plurality of pairs of planetary gear pairs are arranged on the circumference of the planet carrier (7), the first sun gear (3) is mounted on a second shaft (2), a first brake (B1) is arranged between the second shaft (2) and a transmission device shell, the second shaft (2) is locked to be at zero rotation speed when the first brake (B1) is closed, the second sun gear (4) is mounted on the first shaft (1), the first shaft (1) is connected with a rotor (14) of a driving motor (TM) at the same time, the planet carrier (7) is used as a power output shaft, and a clutch (C) is arranged between the first shaft (1) and the first clutch (2).

2. A two-speed electrically driven transmission as claimed in claim 1, wherein: the first clutch (C1) can also be arranged between the first sun gear (3) and the planet carrier (7) or between the second sun gear (4) and the planet carrier (7).

3. A two-speed electrically driven transmission as claimed in claim 1, wherein: the first brake (B1) is a friction plate type brake.

4. A two-speed electrically driven transmission as claimed in claim 1, wherein: the first brake (B1) is a one-way clutch having a rotation speed locking function.

5. A two-speed electrically driven transmission according to claim 1 or 2, characterized in that: the novel electric generator is characterized in that a first reduction gear (16) is fixedly installed on the first shaft (1), a third reduction gear (18) is placed on the transmission shaft (21), the third reduction gear (18) can rotate freely on the transmission shaft (21), a second reduction gear (17) is placed between the first reduction gear (16) and the third reduction gear (18), the second reduction gear (17) is meshed with the first reduction gear (16) and the third reduction gear (18), a second clutch (C2) is arranged between the transmission shaft (21) and the third reduction gear (18), the transmission shaft (21) is used as an input shaft of engine power, a fixed gear (19) on the transmission shaft (21) is meshed with a gear (20) on a generator shaft (22), and the generator shaft (22) is connected with a rotor (23) of a starting generator (ISG).