Longitudinal hybrid transmission, hybrid power assembly and mode switching method thereof, automobile

Abstract

The application provides a longitudinal hybrid transmission, a hybrid assembly and a mode switching method thereof, and an automobile. The transmission comprises a first planetary gear assembly, a second planetary gear assembly, a first brake capable of braking a first sun gear, a second brake capable of braking a second ring gear, an input shaft and an output shaft. The inner diameter of the second ring gear is larger than the inner diameter of the first ring gear, and the outer diameter of the second sun gear is larger than the outer diameter of the first sun gear. The first ring gear and the second sun gear are fixed together as a power input part and connected to the input shaft. The input shaft is in driving connection with an engine. The first carrier and the second carrier are fixed together as a power output part and connected to the output shaft. The output shaft is in driving connection with a motor. The transmission can output a large torque, meet the large torque demand of a large displacement hybrid automobile, have multiple gears, change the speed ratio and the output torque by switching the gears, make the engine and the motor work at the optimal working point, and have a short axial dimension.

Description

Technical Field

[0001] This application relates to the field of automotive technology, and in particular to a longitudinally mounted hybrid transmission, a hybrid powertrain and its mode switching method, and an automobile. Background Technology

[0002] Hybrid vehicles are more economical than gasoline vehicles. In recent years, hybrid vehicles have developed rapidly. Hybrid vehicles are mainly divided into hybrid electric vehicles (HEV) and plug-in hybrid electric vehicles (PHEV). The power of a hybrid electric vehicle mainly comes from a gasoline engine, with an electric motor as an auxiliary power source. It does not require external charging. The power of a plug-in hybrid electric vehicle comes from a gasoline engine and an electric motor. It supports long-term pure electric driving and can be charged by an external power source.

[0003] Currently, most hybrid vehicles on the market are designed based on traditional transmissions, mainly in three forms: (1) adding an electric motor to a traditional dual-clutch transmission (DCT), (2) adding an electric motor to a continuously variable transmission (CVT), and (3) adding an electric motor to an automatic transmission (AT). In addition, more and more hybrid-specific transmissions are also emerging. These hybrid transmissions are mostly transversely mounted, meaning the transmission axis is parallel to the vehicle's wheel axle.

[0004] Large-displacement hybrid vehicles (such as SUVs and pickup trucks) tend to use longitudinally mounted hybrid transmissions, where the transmission's axis is perpendicular to the vehicle's wheel axles, and a high torque output is desired. However, longitudinally mounted hybrid transmissions are relatively rare on the market; most are solutions based on traditional transmissions with the addition of an electric motor. High torque output and fuel economy cannot be simultaneously guaranteed. Therefore, how to simultaneously meet the high torque and fuel economy requirements of longitudinally mounted hybrid vehicles is a technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0005] To address the aforementioned technical problems, this application provides a longitudinally mounted hybrid transmission. The transmission includes a first planetary gear assembly, a second planetary gear assembly, a first brake, a second brake, an input shaft, and an output shaft. The first planetary gear assembly includes a first sun gear, first planet gears, a first planet carrier, and a first ring gear. The second planetary gear assembly includes a second sun gear, second planet gears, a second planet carrier, and a second ring gear. The inner diameter of the second ring gear is larger than the inner diameter of the first ring gear, and the outer diameter of the second sun gear is larger than the outer diameter of the first sun gear. The first ring gear and the second sun gear are fixed together as a power input section connected to the input shaft, which can be connected to an engine for transmission. The first planet carrier and the second planet carrier are fixed together as a power output section connected to the output shaft, which can be connected to an electric motor for transmission. The first brake is used to brake or release the first sun gear, and the second brake is used to brake or release the second ring gear.

[0006] One embodiment of a longitudinally mounted hybrid transmission includes a first clutch, wherein the first sun gear is capable of engaging or disengaging with the first ring gear via the first clutch.

[0007] One embodiment of a longitudinally mounted hybrid transmission includes a second clutch, through which the input shaft can transmit or disconnect power from the output of the engine.

[0008] One embodiment of a longitudinally mounted hybrid transmission includes a one-way clutch connected between the output shaft and the power output unit, such that the output shaft cannot drive the power output unit to rotate, while the power output unit can drive the output shaft to rotate.

[0009] One embodiment of a longitudinally mounted hybrid transmission further includes a reduction planetary gear assembly, which includes a reduction sun gear, reduction planetary gears, a reduction planetary carrier, and a reduction ring gear. The reduction ring gear is fixed, and the output shaft is fixed to the reduction planetary carrier. The reduction sun gear can be connected to the electric motor, so that the output shaft can achieve a transmission connection with the electric motor through the reduction planetary gear assembly.

[0010] In one embodiment of a longitudinally mounted hybrid transmission, the reduction sun gear includes a body portion and a bushing portion, the output shaft passes through the bushing portion and the central hole of the body portion, and the electric motor can be sleeved on the outer side of the bushing portion.

[0011] In one embodiment of a longitudinally mounted hybrid transmission, the second planetary gear assembly and the first planetary gear assembly are arranged sequentially along the radial direction of the second sun gear, and along the radial direction of the second sun gear, the second ring gear and the second planetary gear are located outside the first planetary assembly.

[0012] This application also provides a hybrid powertrain, which includes an engine, an electric motor, and a longitudinally mounted hybrid transmission as described in any of the preceding claims.

[0013] One embodiment of a hybrid powertrain further includes a generator and a reduction gear, wherein the input element of the reduction gear is connected to the output element of the engine, and the generator is connected to the output element of the reduction gear.

[0014] This application also provides a mode switching method for a hybrid powertrain, implemented based on any of the hybrid powertrains described above, the mode switching method comprising:

[0015] The engine is turned on to drive the power input unit to rotate, the first brake releases the first sun gear, the second brake brakes the second ring gear, and the first planetary gear assembly and the second planetary gear assembly achieve a constant speed ratio output through the second sun gear and the second planet carrier, thereby switching to the first gear parallel mode;

[0016] The engine is turned on to drive the power input unit to rotate, causing the first brake to brake the first sun gear and the second brake to release the second ring gear. This allows the first planetary gear assembly and the second planetary gear assembly to achieve a constant speed ratio output through the first sun gear and the first planet carrier, thereby switching to the second gear parallel mode.

[0017] One embodiment of a mode switching method for a hybrid powertrain, wherein the transmission includes a first clutch, and the first sun gear is capable of engaging or disengaging with the first ring gear via the first clutch, the mode switching method comprising:

[0018] The engine is turned on to rotate the power input unit, the first brake is released from braking the first sun gear, the second brake is released from braking the second ring gear, and the first clutch is closed to engage the first sun gear and the first ring gear, thereby switching to the third gear parallel mode.

[0019] This application also provides a vehicle that includes the hybrid powertrain described in any of the preceding claims and employs the mode switching method described in any of the preceding claims.

[0020] The longitudinally mounted hybrid transmission provided in this application can output a large torque, thereby meeting the high torque requirements of large-displacement hybrid vehicles. Moreover, it has multiple gears, and the speed ratio and output torque can be changed by switching gears to make the engine and electric motor work at the optimal operating point, so as to ensure good power and fuel economy. Attached Figure Description

[0021] Figure 1 A schematic diagram of one embodiment of the hybrid powertrain provided in this application;

[0022] Figure 2 A schematic table illustrating the mode switching method of the hybrid powertrain provided in this application.

[0023] The annotations in the attached figures are explained as follows:

[0024] 101 First sun gear, 102 First planet gear, 103 First planet carrier, 104 First gear ring;

[0025] 201 Second sun gear, 202 Second planet gear, 203 Second planet carrier, 204 Second gear ring;

[0026] 30 input axes, 40 output axes;

[0027] 501 Reduction sun gear, 501a Body section, 501b Bushing section, 502 Reduction planet gear, 503 Reduction planet carrier, 504 Reduction ring gear;

[0028] 60 engine, 70 electric motor, 80 generator, 90 torsional damper;

[0029] B1 is the first brake, and B2 is the second brake;

[0030] C1 is the first clutch, C2 is the second clutch, and C3 is the one-way clutch. Detailed Implementation

[0031] To enable those skilled in the art to better understand the technical solution of this application, the technical solution of this application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] like Figure 1 As shown, the hybrid powertrain provided in this application includes at least a longitudinally mounted hybrid transmission, an engine 60, and an electric motor 70. When installed in a vehicle, the axial direction (which is also the power output direction) of the longitudinally mounted hybrid transmission is along the longitudinal direction of the vehicle; that is, the axial direction of the longitudinally mounted hybrid transmission is perpendicular to the axle of the vehicle.

[0033] In some embodiments, such as Figure 1As shown, the hybrid powertrain includes a torsional damper 90 and a generator 80. The input element of the torsional damper 90 is connected to the output element (flywheel) of the engine 60, and the output element of the torsional damper 90 is connected to the generator 80. In this way, the engine 60 can generate electricity for the generator 80.

[0034] like Figure 1 As shown, the longitudinally mounted hybrid transmission (hereinafter referred to as the transmission) includes at least a first planetary gear assembly, a second planetary gear assembly, a first brake B1, a second brake B2, an input shaft 30, and an output shaft 40.

[0035] The first planetary gear assembly includes a first sun gear 101, a first planet gear 102, a first planet carrier 103, and a first ring gear 104. The first planet gear 102 meshes between the first sun gear 101 and the first ring gear 104 and is rotatably mounted on the first planet carrier 103.

[0036] The second planetary gear assembly includes a second sun gear 201, a second planet gear 202, a second planet carrier 203, and a second ring gear 204. The second planet gear 202 meshes between the second sun gear 201 and the second ring gear 204 and is rotatably mounted on the second planet carrier 203.

[0037] The inner diameter of the second gear ring 204 is larger than the inner diameter of the first gear ring 104. The outer diameter of the second sun gear 201 is larger than the outer diameter of the first sun gear 101.

[0038] The first ring gear 104 and the second sun gear 201 are fixed together as a power input section and connected to the input shaft 30, which is then connected to the engine 60. The first planetary carrier 103 and the second planetary carrier 203 are fixed together as a power output section and connected to the output shaft 40, which is then connected to the electric motor 70. The power from the engine 60 can be transmitted through the input shaft 30 to the power input section, causing it to rotate. This power is then transmitted from the power input section to the power output section, causing it to rotate, and finally from the power output section to the output shaft 40, causing it to rotate. The power from the electric motor 70 can be transmitted to the output shaft 40, causing it to rotate.

[0039] The first brake B1 is used to brake or release the first sun gear 101. When braked, the first sun gear 101 cannot rotate; when braked, the first sun gear 101 can rotate. The second brake B2 is used to brake or release the second gear ring 204. When braked, the second gear ring 204 cannot rotate; when braked, the second gear ring 204 can rotate.

[0040] The aforementioned hybrid powertrain can switch modes, such as Figure 2As shown, the mode switching method includes: turning on the engine 60 to rotate the power input unit, releasing the first brake B1 from the first sun gear 101, and braking the second brake B2 against the second ring gear 204. The first sun gear 101 and the first ring gear 104 are in a disengaged state, thereby switching to the first gear parallel mode. In the first gear parallel mode, the power of the engine 60 is transmitted to the power input unit through the input shaft 30, causing the first ring gear 104 and the second sun gear 201 to rotate together. Then, the power is transmitted from the second sun gear 201 to the second planetary carrier 203 via the second planetary gear 202, causing the second planetary carrier 203 and the first planetary carrier 103 to rotate together, driving the output shaft 40 to rotate. A constant speed ratio output is achieved through the second sun gear 201 and the second planetary carrier 203. During this period, the second ring gear 204 remains stationary, while the first planetary gear 102 and the first sun gear 101 rotate accordingly. In this mode, the electric motor 70 can be in the on state, driven by both the engine 60 and the electric motor 70; alternatively, the electric motor 70 can be in the off state, driven solely by the engine 60. The generator 80 can be in the generating state, powered by the engine 60; alternatively, the generator 80 can be in the non-generating state.

[0041] like Figure 2 As shown, the mode switching method further includes: keeping the engine 60 in the on state to drive the power input unit to rotate, causing the first brake B1 to brake the first sun gear 101, and causing the second brake B2 to release the brake on the second ring gear 204, so that the first sun gear 101 and the first ring gear 104 are in a disengaged state, thereby switching to the second gear parallel mode. In the second gear parallel mode, the power of the engine 60 is transmitted to the power input unit through the input shaft 30, causing the first ring gear 104 and the second sun gear 201 to rotate together, and then from the first ring gear 104 through the first planet gear 102 to the first planet carrier 103, causing the first planet carrier 103 and the second planet carrier 203 to rotate together, driving the output shaft 40 to rotate, and achieving a constant speed ratio output through the first sun gear 101 and the first planet carrier 103. During this period, the first sun gear 101 remains stationary, while the second ring gear 204 and the second planet gear 202 rotate accordingly. In this mode, the electric motor 70 can be in the on state, driven by both the engine 60 and the electric motor 70; alternatively, the electric motor 70 can be in the off state, driven solely by the engine 60. The generator 80 can be in the generating state, powered by the engine 60; alternatively, the generator 80 can be in the non-generating state.

[0042] Since the inner diameter of the second gear ring 204 is larger than the inner diameter of the first gear ring 104, and the outer diameter of the second sun gear 201 is larger than the outer diameter of the first sun gear 101, the speed ratio and output torque in the first gear parallel mode are relatively large, which can meet the high torque requirements of large-displacement hybrid vehicles. Moreover, when the input torque is the same, the speed ratio and output torque in the first gear parallel mode are different from those in the second gear parallel mode. Therefore, the speed ratio and output torque can be changed by switching between the first gear and the second gear to make the engine 60 and the electric motor 70 work at the optimal operating point, so as to ensure good power and fuel economy.

[0043] In some embodiments, such as Figure 1 As shown, the input shaft 30 and the output shaft 40 are located on opposite sides of the first sun gear 101 in the axial direction. Thus, the engine 60, which is driven by the input shaft 30, and the electric motor 70, which is driven by the output shaft 40, are located on opposite sides of the first planetary gear assembly and the second planetary gear assembly in the axial direction, which facilitates the layout of the engine 60 and the electric motor 70.

[0044] In some embodiments, such as Figure 1 As shown, the gearbox includes a first clutch C1, through which the first sun gear 101 can engage or disengage with the first ring gear 104. In the first-gear parallel mode and the second-gear parallel mode, the first clutch C1 is disengaged, causing the first sun gear 101 to be disengaged from the first ring gear 104. With the first clutch C1 engaged, the gearbox can switch to the third-gear parallel mode. The mode switching method includes: turning on the engine 60 to rotate the power input unit, releasing the first brake B1 from the first sun gear 101, releasing the second brake B2 from the second ring gear 204, and engaging the first sun gear 101 and the first ring gear 104, thereby switching to the third-gear parallel mode. In the third-gear mode, the first sun gear 101, the first planetary gear 102, the first planetary carrier 103, the first ring gear 104, the second sun gear 201, the second planetary gear 202, the second planetary carrier 203, and the second ring gear 204 all rotate, and the speed ratio of the planetary gear set is 1. In the third transmission mode, the electric motor 70 can be in the on state, driven by both the engine 60 and the electric motor 70; or the electric motor 70 can be in the off state, driven only by the engine 60. The generator 80 can be in the generating state, generated by the engine 60; or the generator 80 can be in the non-generating state.

[0045] In some embodiments, as shown in the figure, the transmission includes a second clutch C2, through which the input shaft 30 can transmit or disconnect power from the engine 60. Specifically, in the figure, the hybrid powertrain includes a torsional damper 90 connected to the output end of the engine 60, and the second clutch C2 is connected between the output end of the torsional damper 90 and the input shaft 30. With the second clutch C2 in place, the transmission can switch to series mode or pure electric mode. The mode switching method includes: both the engine 60 and the electric motor 70 are turned on, the generator 80 is in a generating state, the engine 60 generates electricity for the generator 80, both the first clutch C1 and the second clutch C2 are disengaged, the first brake B1 releases the brake on the first sun gear 101, and the second brake B2 releases the brake on the second ring gear 204, thereby switching to series mode. The mode switching method also includes: turning off the engine 60, turning on the electric motor 70, turning off the generator 80, disengaging both the first clutch C1 and the second clutch C2, releasing the first brake B1 from the first sun gear 101, and releasing the second brake B2 from the second gear ring 204, thereby switching to pure electric mode. Additionally, when both the engine 60 and the electric motor 70 are off, both the first clutch C1 and the second clutch C2 are disengaged, the first brake B1 is released from the first sun gear 101, and the second brake B2 is released from the second gear ring 204, the transmission switches to energy recovery mode, and the recovered energy is used to generate electricity for the electric motor 70.

[0046] In some embodiments, such as Figure 1 As shown, the gearbox includes a one-way clutch C3, which connects the output shaft 40 and the power output unit, preventing the output shaft 40 from driving the power output unit to rotate, while allowing the power output unit to drive the output shaft 40 to rotate. This reduces the drag loss of power from the electric motor 70 caused by the side where the engine 60 is located.

[0047] In some embodiments, the gearbox includes a reduction planetary gear assembly, which includes a reduction sun gear 501, reduction planetary gears 502, a reduction planetary carrier 503, and a reduction ring gear 504. The reduction planetary gears 502 mesh between the reduction sun gear 501 and the reduction ring gear 504 and are rotatably mounted on the reduction planetary carrier 503. The reduction ring gear 504 is fixed, the output shaft 40 is fixed to the reduction planetary carrier 503, and the reduction sun gear 501 is connected to the electric motor 70, enabling the output shaft 40 to be driven by the electric motor 70 through the reduction gear assembly. The power of the electric motor 70 can be transmitted to the output shaft 40 through the reduction planetary gear assembly. By providing the reduction planetary gear assembly, the gear ratio and output torque of the gearbox can be further increased.

[0048] In some embodiments, such as Figure 1 As shown, the reduction sun gear 501 includes a body portion 501a and a bushing portion 501b. The output shaft 40 passes through the bushing portion 501b and the central hole of the body portion 501a. The motor 70 is sleeved on the outside of the bushing portion 501b. This reduces the axial dimension of the gearbox, thereby reducing the axial space occupied by the gearbox in the vehicle and broadening its applicability.

[0049] In some embodiments, such as Figure 1 As shown, the second planetary gear assembly and the first planetary gear assembly are arranged sequentially along the radial direction of the second sun gear 201. Along the radial direction of the second sun gear 201, the second ring gear 204 and the second planetary gear 202 are located outside the first planetary assembly. This reduces the axial dimension of the transmission, thereby reducing the axial space occupied by the transmission in the vehicle and broadening its applicability.

[0050] The vehicle provided in this application includes the hybrid powertrain provided in this application and adopts the mode switching method provided in this application.

[0051] In some embodiments, the vehicle is a hybrid electric vehicle.

[0052] In some embodiments, the vehicle is a plug-in hybrid electric vehicle.

[0053] In some embodiments, the vehicle is a large-displacement vehicle such as a pickup truck or SUV.

[0054] The above embodiments can be freely combined without conflict.

[0055] The above examples illustrate the principles and implementation methods of this application. The descriptions of the embodiments are merely for the purpose of helping to understand the methods and core ideas of this application. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from its principles, and these improvements and modifications also fall within the protection scope of this application.

Claims

1. A longitudinally mounted hybrid transmission, characterized in that, The gearbox includes a first planetary gear assembly, a second planetary gear assembly, a first brake (B1), a second brake (B2), an input shaft (30), and an output shaft (40). The first planetary gear assembly includes a first sun gear (101), a first planetary gear (102), a first planet carrier (103), and a first ring gear (104). The second planetary gear assembly includes a second sun gear (201), a second planetary gear (202), a second planet carrier (203), and a second ring gear (204). The inner diameter of the second ring gear (204) is larger than the inner diameter of the first ring gear (104), and the outer diameter of the second sun gear (201) is larger than that of the first sun gear. The outer diameter of (101), the first gear ring (104) and the second sun gear (201) are fixed together as a power input part and connected to the input shaft (30), the input shaft (30) can be connected to the engine (60) for transmission, the first planet carrier (103) and the second planet carrier (203) are fixed together as a power output part and connected to the output shaft (40), the output shaft (40) can be connected to the electric motor (70) for transmission, the first brake (B1) is used to brake or release the first sun gear (101), and the second brake (B2) is used to brake or release the second gear ring (204).

2. The longitudinally mounted hybrid transmission according to claim 1, characterized in that, The gearbox includes a first clutch (C1), and the first sun gear (101) can engage or disengage with the first ring gear (104) via the first clutch (C1).

3. The longitudinally mounted hybrid transmission according to claim 1, characterized in that, The gearbox includes a second clutch (C2), through which the input shaft (30) can transmit or disconnect power from the output end of the engine (60).

4. The longitudinally mounted hybrid transmission according to claim 3, characterized in that, The gearbox includes a one-way clutch (C3) connected between the output shaft (40) and the power output unit, so that the output shaft (40) cannot drive the power output unit to rotate, while the power output unit can drive the output shaft (40) to rotate.

5. The longitudinally mounted hybrid transmission according to claim 1, characterized in that, The gearbox also includes a reduction planetary gear assembly, which includes a reduction sun gear (501), reduction planetary gears (502), a reduction planetary carrier (503), and a reduction ring gear (504). The reduction ring gear (504) is fixed, and the output shaft (40) is fixed together with the reduction planetary carrier (503). The reduction sun gear (501) can be connected to the electric motor (70), so that the output shaft (40) can be connected to the electric motor (70) through the reduction planetary gear assembly.

6. The longitudinally mounted hybrid transmission according to claim 5, characterized in that, The reduction sun gear (501) includes a body part (501a) and a bushing part (501b). The output shaft (40) passes through the bushing part (501b) and the central hole of the body part (501a). The motor (70) can be sleeved on the outside of the bushing part (501b).

7. The longitudinally mounted hybrid transmission according to any one of claims 1-6, characterized in that, The second planetary gear assembly and the first planetary gear assembly are arranged sequentially along the radial direction of the second sun gear (201). Along the radial direction of the second sun gear (201), the second gear ring (204) and the second planetary gear (202) are located outside the first planetary assembly.

8. A hybrid powertrain, characterized in that, The hybrid powertrain includes an engine (60), an electric motor (70), and a longitudinally mounted hybrid transmission as described in any one of claims 1-7.

9. The hybrid powertrain according to claim 8, characterized in that, The hybrid powertrain also includes a generator (80) and a torsional damper (90), the input element of which is connected to the output element of the engine (60), and the generator (80) is connected to the output element of the torsional damper (90).

10. A mode switching method for a hybrid powertrain, implemented based on the hybrid powertrain of claim 8 or 9, characterized in that, The mode switching method includes: The engine (60) is turned on to drive the power input unit to rotate, so that the first brake (B1) releases the brake on the first sun gear (101), and the second brake (B2) brakes the second ring gear (204), so that the first planetary gear assembly and the second planetary gear assembly achieve a constant speed ratio output through the second sun gear (201) and the second planet carrier (203), thereby switching to the first gear parallel mode; The engine (60) is turned on to drive the power input unit to rotate, so that the first brake (B1) brakes the first sun gear (101), and the second brake (B2) releases the brake on the second ring gear (204), so that the first planetary gear assembly and the second planetary gear assembly achieve a constant speed ratio output through the first sun gear (101) and the first planet carrier (103), thereby switching to the second gear parallel mode.

11. The mode switching method according to claim 8, characterized in that, The gearbox includes a first clutch (C1), and the first sun gear (101) can engage or disengage with the first ring gear (104) via the first clutch (C1). The mode switching method includes: The engine (60) is turned on to drive the power input unit to rotate, so that the first brake (B1) releases the brake on the first sun gear (101), the second brake (B2) releases the brake on the second gear ring (204), and the first clutch (C1) is closed to put the first sun gear (101) and the first gear ring (104) into a engaged state, thereby switching to the third gear parallel mode.

12. A car, characterized in that, The vehicle includes the hybrid powertrain of claim 8 or 9 and employs the mode switching method of claim 10 or 11.

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