A multi-gear single intermediate shaft dual-motor hybrid power system and control method

Abstract

The application belongs to a light commercial vehicle hybrid power system, in particular to a multi-gear single-intermediate-shaft double-motor hybrid power system and a control method, comprising an engine, a first motor, a second motor, an engine input shaft, an intermediate shaft and an output shaft; the engine is connected with the engine input shaft, the first motor, the engine and the intermediate shaft are arranged in parallel; the first motor is connected with the engine input shaft in sequence by a first motor input gear and a first motor main reduction driven gear; a two-gear shifting structure is arranged between the intermediate shaft and the output shaft. The application adopts a double-motor structure, the output shaft is provided with a shifting structure, the selectable gear mode is more, the corresponding gear can be selected according to the scene requirement, the motor and the engine can run in the high-efficiency zone, and the economy is higher.

Description

Technical Field

[0001] This invention pertains to hybrid power systems for light commercial vehicles, specifically a multi-speed single intermediate shaft dual-motor hybrid power system and its control method. Background Technology

[0002] Currently, hybrid power systems include an engine, an electric motor, and a transmission; the electric motor can be either a single-motor solution or a dual-motor solution.

[0003] In existing technologies, single-motor solutions use a single drive motor, such as Figure 1 As shown, a common configuration is a low-speed single-motor system combined with an AMT (Automated Manual Transmission). The engine is directly connected to the motor via a clutch, and the engine and motor can provide power independently or jointly. When the vehicle decelerates, the motor provides a counter-torque to generate electricity, achieving energy recovery. Because a single motor can only drive or generate electricity, its operating mode is limited, resulting in minimal fuel savings.

[0004] In existing dual-motor solutions, the most common type is the power-split planetary gear hybrid system, such as... Figure 2 As shown, one motor generates electricity while the other drives the engine. This design offers high engine efficiency and good fuel economy, while also ensuring uninterrupted power during gear shifts, enhancing driving comfort. However, the lack of a direct drive affects fuel economy at high speeds, and the presence of power on the driveshaft when the engine is parked poses a safety risk. Summary of the Invention

[0005] This invention provides a multi-speed single intermediate shaft dual-motor hybrid power system and control method. It adopts a dual-motor structure, adds a shifting structure to the output shaft, and offers multiple selectable gear modes. The appropriate gear can be selected according to the needs of the scenario, so that the motor and engine can operate in the high-efficiency range, resulting in higher economy.

[0006] To achieve the above objectives, the present invention provides a multi-speed single intermediate shaft dual-motor hybrid power system, comprising an engine, a first motor, a second motor, an engine output shaft, an intermediate shaft, and an output shaft; the engine is connected to the engine output shaft, and the first motor, the engine, and the intermediate shaft are arranged in parallel. The first motor is sequentially connected to the engine output shaft via a first motor input gear and a first motor main reduction driven gear. The second motor is connected to the intermediate shaft via the second motor input gear and the second motor main reduction driven gear in sequence; A first synchronizer is provided at the end of the engine output shaft; A ramp gear drive gear is sleeved on the engine output shaft in front of the first synchronizer, and the ramp gear drive gear is connected to the ramp gear driven gear fixedly mounted on the intermediate shaft; The output shaft is provided with a direct engagement gear at its front end; The first synchronizer selectively outputs engine output shaft power from either the climbing gear drive gear or the direct drive gear engagement gear; A two-speed shifting structure is provided between the intermediate shaft and the output shaft.

[0007] This invention adopts a dual-motor structure with a first motor and a second motor, and adds a gear shift (two speeds) between the intermediate shaft and the output shaft to achieve three selectable speeds for the engine and two selectable speeds for the second motor. Compared with the existing technical solutions, this invention offers more selectable gear modes under various driving modes, and the appropriate gear can be selected according to the needs of the scenario, so that the motor and engine operate in the high-efficiency range, resulting in higher economy.

[0008] Preferably, the two-speed shifting structure is configured as follows: a second synchronizer is provided on the output shaft; a second driven gear is sleeved on the output shaft in front of the second synchronizer, and the second driven gear cooperates with a second driving gear fixedly mounted on the intermediate shaft; a first driven gear is sleeved on the output shaft behind the second synchronizer, and the second driven gear cooperates with a first driving gear fixedly mounted on the intermediate shaft. The second synchronizer selectively transmits the power of the intermediate shaft from the first driven gear or the second driven gear to the output shaft.

[0009] Preferably, the motor shaft of the second motor is a hollow shaft, and the engine output shaft extends behind the driven gear of the first motor's main reduction gear and passes through the motor shaft of the second motor. This hollow sleeve structure results in a compact design.

[0010] Preferably, the output shaft is coaxially disposed at a position behind the engine output shaft.

[0011] Preferably, a torsional damper and a clutch are provided between the engine and the driven gear of the first motor reduction gear.

[0012] The present invention also provides a control method that uses the above-mentioned multi-speed single intermediate shaft dual-motor hybrid power system. By collecting vehicle status information, the method determines the driving mode and selects the gear. The driving modes include pure electric mode, pure engine mode, range-extended hybrid mode, and parallel hybrid mode. The vehicle status information includes vehicle power demand, vehicle speed, gradient, and battery charge.

[0013] Preferably, in the pure electric mode, the second motor outputs power independently, with two selectable gears. The power transmission path is: second motor, second motor input gear, second motor main reduction driven gear, intermediate shaft, and then the power is selectively output from the 1st gear driven gear or the 2nd gear driven gear to the output shaft via the second synchronizer.

[0014] Preferably, in pure engine mode, the first synchronizer and the second synchronizer are controlled to achieve three selectable gears; if the first synchronizer outputs engine power to the climbing gear drive gear, the climbing mode is entered, and the power passes through the climbing gear driven gear, the intermediate shaft, and then is selectively output to the output shaft from the 1st gear driven gear or the 2nd gear driven gear through the second synchronizer; if the first synchronizer outputs engine power to the direct drive engagement gear, the direct drive mode is entered, and the engine output shaft power is directly output to the output shaft.

[0015] Preferably, in the range-extended hybrid mode, the first synchronizer is in the middle position, and the engine generates electricity for the first motor through the driven gear of the first motor main reduction gear and the input gear of the first motor; the second motor outputs power independently, and the power passes through the second motor input gear, the driven gear of the second motor main reduction gear, and the intermediate shaft, and then is selectively output to the output shaft through the second synchronizer from the 1st gear driven gear or the 2nd gear driven gear; the electrical energy consumed by the second motor is equivalent to the electrical energy generated by the first motor, and the electrical energy is kept in balance.

[0016] Preferably, in the parallel hybrid mode, the power output of the engine and the second motor is combined. When the first synchronizer is always selected to be in the climbing gear position, the engine power passes through the climbing gear drive gear, the climbing gear driven gear, and the intermediate shaft; the power of the second motor passes through the second motor input gear, the second motor main reduction driven gear, and the intermediate shaft; the power of the engine and the second motor is combined on the intermediate shaft, and then output to the output shaft through the second synchronizer (selectively from the 1st gear driven gear or the 2nd gear driven gear).

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. Dual-motor structure with a shifter (2-speed) added to the output shaft, enabling the engine to operate in three gears and the second motor in two gears; compared with existing technical solutions, this proposal offers more selectable gear modes under various driving modes, allowing the appropriate gear to be selected according to the needs of the scenario, so that the motor and engine can operate in the high-efficiency range, resulting in higher economy; 2. The first motor is connected to the engine only through a single-stage gear transmission, resulting in high power generation efficiency and improved transmission efficiency; 3. The engine, first motor, and second motor can output power simultaneously, providing strong power from all three power sources. 4. It has a direct drive for the engine, which simplifies the transmission components and improves transmission efficiency. Attached Figure Description

[0018] Figure 1 This is a structural diagram of a single-motor hybrid system configuration in the existing technology.

[0019] Figure 2 This is a structural diagram of a dual-motor hybrid system configuration in the prior art.

[0020] Figure 3This is a schematic diagram of the structure of a multi-speed single intermediate shaft dual-motor hybrid power system according to the present invention.

[0021] Figure 4 This is a schematic diagram of the structure of Embodiment 3 of the present invention.

[0022] In the diagram: 1-Engine, 2-First motor main reduction driven gear, 3-Second motor, 4-Second motor main reduction driven gear, 5-Climbing gear driven gear, 6-2nd gear drive gear, 7-1st gear drive gear, 8-First motor, 9-First motor input gear, 10-Second motor input gear, 11-Climbing gear drive gear, 12-First synchronizer, 13-Direct drive engagement gear, 14-2nd gear driven gear, 15-Second synchronizer, 16-1st gear driven gear, 17-Torsion damper, 18-Engine output shaft, 19-Intermediate shaft, 20-Output shaft, 21-Clutch. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. The illustrative embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation of the present invention.

[0024] In the description of this invention, it should be understood that the terms "left", "right", "up", "down", "front", "back", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or structure referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention. Example 1:

[0025] like Figure 3 As shown, this embodiment is a multi-speed single intermediate shaft dual-motor hybrid power system. In this embodiment, the front is defined as the direction of engine 1, and the rear is the direction of output shaft 20, that is, the power of engine 1 is transmitted from front to rear. This embodiment includes engine 1, first motor 8, second motor 3, engine output shaft 18, intermediate shaft 19 and output shaft 20; engine 1 is connected to engine output shaft 18, and first motor 8, engine 1 and intermediate shaft 19 are arranged in parallel. The first motor 8 is powered by the first motor input gear 9 and the first motor main reduction driven gear 2, which are connected to the engine output shaft 18 in sequence. The second motor 3 is powered by the second motor input gear 10 and the second motor main reduction driven gear 4, which are connected to the intermediate shaft 19 in sequence. A first synchronizer 12 is provided at the end of the engine output shaft 18; A ramp drive gear 11 is fitted on the engine output shaft 18 in front of the first synchronizer 12. The ramp drive gear 11 is connected to the ramp driven gear 5 fixedly mounted on the intermediate shaft 19. The output shaft 20 is provided with a direct engagement gear 13 at its foremost end; The first synchronizer 12 selectively outputs power from the engine output shaft 18 from either the climbing gear drive gear 11 or the direct drive engagement gear 13; A two-speed shifting structure is provided between the intermediate shaft 19 and the output shaft 20.

[0026] In this embodiment, the two-speed shifting structure is configured as follows: a second synchronizer 15 is provided on the output shaft 20; a second driven gear 14 is sleeved on the output shaft 20 in front of the second synchronizer 15, and the second driven gear 14 cooperates with a second driving gear 6 fixedly mounted on the intermediate shaft 19; a first driven gear 16 is sleeved on the output shaft 20 behind the second synchronizer 15, and the second driven gear 14 cooperates with a first driving gear 7 fixedly mounted on the intermediate shaft 19. The second synchronizer 15 selectively transmits the power of the intermediate shaft 19 from the first driven gear 16 or the second driven gear 14 to the output shaft 20.

[0027] In this embodiment, the motor shaft of the second motor 3 is a hollow shaft, and the engine output shaft 18 extends behind the main reduction driven gear 2 of the first motor and passes through the motor shaft of the second motor 3.

[0028] In this embodiment, the output shaft 20 is coaxially disposed behind the engine output shaft 18. Example 2:

[0029] This embodiment describes a control method for a multi-speed single-intermediate-shaft dual-motor hybrid power system as described in Embodiment 1 above. It determines the driving mode and selects the gear by collecting vehicle status information. The driving modes include pure electric mode, pure engine mode, range-extended hybrid mode, and parallel hybrid mode. The vehicle status information includes vehicle power demand, vehicle speed, gradient, and battery charge.

[0030] like Figure 3As shown, in this embodiment, the pure electric mode is powered solely by the second motor 3, with two selectable gears. The power transmission path is: second motor 3, second motor input gear 10, second motor main reduction driven gear 4, intermediate shaft 19, and then selectively output from either the 1st gear driven gear 16 or the 2nd gear driven gear 14 to the output shaft 20 via the second synchronizer 15. In pure electric mode, the second motor 3 outputs power solely, with the power transmission path being via the second motor input gear 10 and the second motor main reduction driven gear 4 to the intermediate shaft 19. At this time, two gears are selectable, namely 1st and 2nd gear, selected by controlling the second synchronizer 15 (1st / 2nd gear synchronizer assembly). After engaging the corresponding gear, power is immediately transmitted to the output shaft 20. In this mode, the climbing / direct drive synchronizer assembly is in the middle position, and the engine 1 and the first motor 8 are not operating.

[0031] like Figure 3 As shown, in this embodiment, in pure engine mode, the first synchronizer 12 and the second synchronizer 15 are controlled to achieve three selectable gears. If the first synchronizer 12 outputs engine power to the climbing gear drive gear 11, the climbing mode is entered. The power passes through the climbing gear driven gear 5 and the intermediate shaft 19, and then is selectively output to the output shaft 20 through the second synchronizer 15 from the 1st gear driven gear 16 or the 2nd gear driven gear 14. If the first synchronizer 12 outputs engine power to the direct drive engagement gear, the direct drive mode is entered, and the engine output shaft 18 directly outputs power to the output shaft 20. In pure engine mode, three gears are selectable by controlling the climbing / direct drive synchronizer assembly and the 1st / 2nd gear synchronizer assembly. The power transmission path is as follows: In 1st / 2nd gear, when the first synchronizer 12 (climbing / direct drive synchronizer assembly) is in the climbing gear position, the power from engine 1 is transmitted through the torsional damper 17, engine output shaft 18, climbing gear drive gear 11, climbing gear driven gear 5, and then to either the 1st or 2nd gear drive gear. The power is then selected by controlling the 1st / 2nd gear synchronizer assembly, and the corresponding power is transmitted to the 1st or 2nd gear driven gear, and then to the output shaft 20. In direct drive mode, when the first synchronizer 12 (climbing / direct drive synchronizer assembly) is in the direct drive position, the power from engine 1 is transmitted through the torsional damper 17 and engine output shaft 18 to the output shaft 20. At this time, the 1st / 2nd gear synchronizer assembly is in the intermediate position. In this mode, the first motor 8 and the second motor 3 do not operate.

[0032] like Figure 3As shown, in this embodiment, in the range-extended hybrid mode, the first synchronizer 12 is in the middle position. The engine 1 generates electricity for the first motor 8 through the main reduction gear of the first motor 8 and the input gear 9 of the first motor. The second motor 3 outputs power independently. The power passes through the second motor input gear 10, the second motor main reduction gear 4, and the intermediate shaft 19, and then is selectively output to the output shaft 20 through the second synchronizer 15 from either the 1st gear driven gear 16 or the 2nd gear driven gear 14. The electrical energy consumed by the second motor 3 is equivalent to the electrical energy generated by the first motor 8, and the electrical balance is maintained. In the range-extended hybrid mode, the power transmission path is as follows: when the first synchronizer 12 (climbing gear / direct drive synchronizer assembly) is in the middle position, the engine 1 generates electricity for the first motor 8 through the main reduction gear of the first motor 8 and the input gear 9 of the first motor. The second motor 3 drives the vehicle independently, and the power transmission path of the second motor 3 is the same as in the pure electric mode. At this time, the electrical energy consumed by the second motor 3 is equivalent to the electrical energy generated by the first motor 8, and the electrical balance is maintained.

[0033] like Figure 3 As shown, in this embodiment, in the parallel hybrid power mode, the power output of engine 1 and second motor 3 is combined. When the first synchronizer 12 selects the climbing gear position, the power of engine 1 passes through the climbing gear drive gear 11, the climbing gear driven gear 5, and the intermediate shaft 19; the power of second motor 3 passes through the second motor input gear 10, the second motor main reduction driven gear 4, and the intermediate shaft 19; the power of engine 1 and second motor 3 is combined at the intermediate shaft 19, and then selectively output to the output shaft 20 from the 1st gear driven gear 16 or the 2nd gear driven gear 14 through the second synchronizer 15. In this parallel hybrid system, the power transmission of engine 1 and second motor 3 is combined. The power transmission path is as follows: when the first synchronizer 12 (climbing gear / direct drive synchronizer assembly) is in the climbing gear position, the power of engine 1 and second motor 3 is combined on the intermediate shaft 19 and output through the 1st or 2nd gear transmission path; when the first synchronizer 12 (climbing gear / direct drive synchronizer assembly) is in the direct drive position, the power of engine 1 and second motor 3 is combined on the output shaft 20, and second motor 3 can be selected to be in 1st or 2nd gear. The first motor 8 can be selected to be either inactive or provide assistance at this time. Example 3:

[0034] like Figure 4As shown, the difference between this embodiment and the above-described embodiment 2 is that a torsional damper 17 and a clutch 21 are provided between the engine 1 and the driven gear of the first motor 8. The main difference in adding a clutch 21 between the engine 1 and the driven gear of the first motor 8 is that it enables dual-motor drive in pure electric drive mode. That is, when the clutch 21 is disengaged, the connection between the engine 1 and the first motor 8 is broken. When the first synchronizer 12 (climbing gear / direct drive synchronizer assembly) is in climbing gear or direct drive position, the first motor 8 and the second motor 3 can simultaneously drive the vehicle, improving the power performance of pure electric drive. The clutch 21 can be a dry clutch, a wet clutch, an electromagnetic clutch, etc.

Claims

1. A multi-gear single intermediate shaft dual motor hybrid system, characterized by It includes an engine (1), a first motor (8), a second motor (3), an engine output shaft (18), an intermediate shaft (19), and an output shaft (20); the engine (1) is connected to the engine output shaft (18), and the first motor (8), the engine (1), and the intermediate shaft (19) are arranged in parallel; The first motor (8) is connected to the engine output shaft (18) by the first motor input gear (9) and the first motor main reduction driven gear (2) in sequence. The second motor (3) is connected to the intermediate shaft (19) in sequence by the second motor input gear (10) and the second motor main reduction driven gear (4); A first synchronizer (12) is provided at the end of the engine output shaft (18); A ramp drive gear (11) is fitted on the engine output shaft (18) in front of the first synchronizer (12), and the ramp drive gear (11) is connected to the ramp driven gear (5) fixedly installed on the intermediate shaft (19); The output shaft (20) is provided with a direct engagement gear (13) at its front end. The first synchronizer (12) selectively outputs power from the engine output shaft (18) from either the climbing gear drive gear (11) or the direct drive engagement gear (13); A two-speed shifting structure is provided between the intermediate shaft (19) and the output shaft (20).

2. The multi-gear single countershaft dual-motor hybrid power system according to claim 1, characterized in that The two-speed shifting structure is constructed as follows: a second synchronizer (15) is provided on the output shaft (20), a second driven gear (14) is sleeved on the output shaft (20) in front of the second synchronizer (15), the second driven gear (14) cooperates with the second driving gear (6) fixedly set on the intermediate shaft (19); a first driven gear (16) is sleeved on the output shaft (20) behind the second synchronizer (15), the second driven gear (14) cooperates with the first driving gear (7) fixedly set on the intermediate shaft (19), and the second synchronizer (15) selectively transmits the power of the intermediate shaft (19) from the first driven gear (16) or the second driven gear (14) to the output shaft (20).

3. The multi-speed single intermediate shaft dual-motor hybrid power system according to claim 1, characterized in that: The motor shaft of the second motor (3) is a hollow shaft, and the engine output shaft (18) extends behind the main reduction driven gear (2) of the first motor and passes through the motor shaft of the second motor (3).

4. The multi-speed single intermediate shaft dual-motor hybrid power system according to claim 1, characterized in that: The output shaft (20) is coaxially positioned behind the engine output shaft (18).

5. A multi-speed single intermediate shaft dual-motor hybrid power system according to claim 1, characterized in that: A torsional damper (17) and a clutch (21) are provided between the engine (1) and the driven gear of the first motor (8).

6. A control method for a multi-speed single-intermediate-shaft dual-motor hybrid power system according to any one of claims 1 to 4, characterized in that... The driving mode and gear selection are determined by collecting vehicle status information. The driving modes include pure electric mode, pure engine mode, range-extended hybrid mode, and parallel hybrid mode. The vehicle status information includes vehicle power demand, vehicle speed, gradient, and battery charge.

7. The control method according to claim 6, characterized in that: The pure electric mode is powered by the second motor (3) alone. There are two gears to choose from. The power transmission path is: second motor (3), second motor input gear (10), second motor main reduction driven gear (4), intermediate shaft (19), and then the power is selectively output from the first gear driven gear (16) or the second gear driven gear (14) to the output shaft (20) through the second synchronizer (15).

8. The control method according to claim 6, characterized in that: In pure engine mode, the first synchronizer (12) and the second synchronizer (15) are controlled to achieve three selectable gears; if the first synchronizer (12) outputs the engine (1) power to the climbing gear drive gear (11), the climbing mode is entered. The power passes through the climbing gear driven gear (5), the intermediate shaft (19), and then is selectively output from the 1st gear driven gear (16) or the 2nd gear driven gear (14) to the output shaft (20) through the second synchronizer (15); if the first synchronizer (12) outputs the engine (1) power to the direct drive engagement gear, the direct drive mode is entered. The engine output shaft (18) outputs the power directly to the output shaft (20).

9. The control method according to claim 6, characterized in that: In the range-extended hybrid mode, the first synchronizer (12) is in the middle position, and the engine (1) generates electricity for the first motor (8) through the main reduction driven gear of the first motor (8) and the input gear of the first motor (9); the second motor (3) outputs power independently, and the power passes through the second motor input gear (10), the second motor main reduction driven gear (4), the intermediate shaft (19), and then is selectively output to the output shaft (20) through the second synchronizer (15) from the 1st gear driven gear (16) or the 2nd gear driven gear (14); the electrical energy consumed by the second motor (3) is equivalent to the electrical energy generated by the first motor (8), and the electrical energy is kept in balance.

10. The control method according to claim 6, characterized in that: In the parallel hybrid mode, the power output of the engine (1) and the second motor (3) is combined. When the first synchronizer (12) is always selected to climb gear, the power of the engine (1) passes through the climbing gear drive gear (11), the climbing gear driven gear (5), and the intermediate shaft (19); the power of the second motor (3) passes through the second motor input gear (10), the second motor main reduction driven gear (4), and the intermediate shaft (19); the power of the engine (1) and the second motor (3) is combined on the intermediate shaft (19), and then selectively output to the output shaft (20) from the 1st gear driven gear (16) or the 2nd gear driven gear (14) through the second synchronizer (15).

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