A multi-mode power-split hybrid powertrain

Abstract

The present application discloses a multi-mode power split hybrid transmission system, which relates to the field of hybrid transmission technology. It can improve the power utilization of the motor, not only reducing the power level of the two motors, reducing the size and weight of the motors, but also ensuring the continuity of the speed between the three modes. In this system, the sun gear of the first planetary row, the output end of the first motor fixed transmission ratio mechanism, the input end of the first clutch fixed transmission ratio mechanism and the ring gear of the second planetary row are fixedly connected; the engine is connected to the planetary carrier of the first planetary row through the engine fixed transmission ratio structure; the first ring gear and the second planetary carrier are fixedly connected; the first motor is connected to the input end of the first motor fixed transmission ratio mechanism; the second motor is connected to the second sun gear through the second motor fixed transmission ratio structure; the two active ends of the dual clutch mechanism are respectively connected to the corresponding clutch fixed transmission ratio mechanism, and the driven end is connected to the drive axle.

Description

Technical Field

[0001] The present application relates to the field of hybrid power transmission technology, and in particular to a multi-mode power split hybrid power transmission system suitable for heavy-duty trucks. Background Art

[0002] Against the backdrop of energy conservation and emission reduction, hybrid technology is becoming increasingly mature. Since it combines the advantages of fuel-powered vehicles and pure electric vehicles, its application in vehicles with relatively large curb weight, such as heavy-duty trucks, large passenger buses, and city buses, can improve fuel economy and improve exhaust emissions while ensuring safety and reliability.

[0003] The powertrains of medium- and heavy-duty vehicles require ample backup power and torque to meet the torque requirements of starting and the power demands of high-speed driving or uphill driving. However, existing single-mode power-split electromechanical hybrid transmission systems require high motor power levels. Summary of the Invention

[0004] An embodiment of the present application provides a multi-mode power-split hybrid transmission system, which uses a planetary gear structure as a coupling mechanism to achieve dual decoupling of speed and torque; uses a dual clutch to achieve switching between input split mode, compound split mode, and fixed transmission ratio mode, thereby improving the power utilization of the motor. It not only reduces the power levels of the two motors and reduces the size and weight of the motors, but the fixed transmission ratio mode can also well connect the input split mode and the compound split mode, ensuring the continuity of speed between the three modes.

[0005] To achieve the above objectives, an embodiment of the present application provides a multi-mode power-split hybrid powertrain system, comprising an engine, a first motor, a second motor, a dual-clutch mechanism, a drive axle, a first planetary gear set, a second planetary gear set, an engine fixed gear ratio structure, a first motor fixed gear ratio structure, a second motor fixed gear ratio structure, a first clutch fixed gear ratio structure, and a second clutch fixed gear ratio structure; the first planetary gear set comprises a first ring gear, a first planetary carrier, a first sun gear, and a first planetary gear; the second planetary gear set comprises a second ring gear, a second planetary carrier, a second sun gear, and a second planetary gear; the first sun gear, an output end of the first motor fixed gear ratio structure, an input end of the first clutch fixed gear ratio structure, and the second ring gear are fixedly connected; the engine is connected to the first planetary carrier via the engine fixed gear ratio structure; the first ring gear and the second planetary carrier are fixedly connected; the first motor is connected to the input end of the first motor fixed gear ratio structure; the second motor is connected to the second sun gear via the second motor fixed gear ratio structure; the output end of the first clutch fixed gear ratio structure is connected to the first active end of the dual-clutch mechanism; the second planetary carrier is connected to the second active end of the dual-clutch mechanism via the second clutch fixed gear ratio structure; and the passive end of the dual-clutch mechanism is connected to the drive axle.

[0006] Furthermore, the first sun gear, the output end of the first motor fixed transmission ratio mechanism, the input end of the first clutch fixed transmission ratio mechanism and the second ring gear are all fixedly connected to the sleeve shaft; the sleeve shaft is rotatably connected to the connecting shaft; the first ring gear is fixedly connected to the first end of the connecting shaft; and the second planetary carrier is fixedly connected to the second end of the connecting shaft.

[0007] Furthermore, the engine fixed transmission ratio structure includes a first gear pair.

[0008] Furthermore, the first motor fixed transmission ratio mechanism includes a second gear pair.

[0009] Furthermore, the second motor fixed transmission ratio mechanism includes a third gear pair.

[0010] Furthermore, the first clutch fixed transmission ratio mechanism includes a fourth gear pair.

[0011] Furthermore, the second clutch fixed transmission ratio mechanism includes a fifth gear pair.

[0012] Furthermore, the first motor and the second motor are both motors with driving / generating working states.

[0013] This application has the following beneficial effects:

[0014] 1. The multi-mode power-split hybrid transmission system of the embodiment of the present application adopts a planetary gear and a fixed-axis mechanism for transmission, which has a compact structure, smooth transmission, and high transmission efficiency; and adopts a dual-clutch mechanism, making the control structure of the transmission system more compact.

[0015] 2. The multi-mode power-split hybrid transmission system of the embodiment of the present application adopts a power-split electromechanical compound transmission, which can ensure that the engine and the motor operate more in the high-efficiency range, and connect the input split working mode and the compound split working mode through the fixed transmission ratio working mode, so that the system can fully utilize the high-efficiency range of the engine.

[0016] 3. The multi-mode power-split hybrid transmission system of the embodiment of the present application has a multi-mode transmission mode, which can improve the power utilization of the motor, thereby reducing the power level of the two motors and reducing the size and weight of the motors; it can provide a wider speed regulation range to meet the power requirements of various working conditions of medium-sized vehicles and heavy-duty vehicles.

[0017] 4. In the multi-mode power split hybrid power transmission system of the embodiment of the present application, the rotational speeds of the power components are continuous during mode switching, which can achieve switching without power interruption, reduce clutch wear, and improve the mode switching quality and the controllability of the entire power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0019] Figure 1 This is a structural diagram of a multi-mode power split hybrid power transmission system according to an embodiment of the present application;

[0020] Figure 2 This is a power flow diagram of the multi-mode power split hybrid powertrain system in input split mode according to an embodiment of the present application;

[0021] Figure 3 This is a power flow diagram of the multi-mode power split hybrid power transmission system in compound split mode according to an embodiment of the present application;

[0022] Figure 4 This is a power flow diagram of a multi-mode power split hybrid powertrain system in a fixed transmission ratio mode according to an embodiment of the present application;

[0023] Figure 5 This is a power flow diagram of the multi-mode power split hybrid powertrain system in pure electric mode according to an embodiment of the present application;

[0024] Figure 6 A speed relationship diagram of a forward working condition of a multi-mode power split hybrid powertrain system according to an embodiment of the present application;

[0025] Figure 7 This is a speed relationship diagram of the multi-mode power split hybrid power transmission system in the full speed range of an embodiment of the present application. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0027] In the description of this application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0028] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "install", "connect", and "connect" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0029] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. Throughout this application, unless otherwise specified, "plurality" means two or more.

[0030] This embodiment of the present application adds a fixed transmission ratio mechanism at the connection between the engine and two motors and the planetary gear mechanism. It also adds a fixed transmission ratio mechanism at each active end of the dual-clutch mechanism. This rationalizes the transmission structure and optimizes the operating points of the engine and motors by selecting appropriate transmission ratios. The engine, two motors, and drive axle are collectively referred to as the external force components. The planetary gear mechanism is the primary component for achieving power coupling and diversion, and its operating characteristics significantly impact the performance of the entire system.

[0031] Reference Figure 1 An embodiment of the present application provides a multi-mode power-split hybrid powertrain system, including an engine 1, a dual-clutch mechanism, a drive axle 16, a first planetary gear set K1, a second planetary gear set K2, a first motor A, a second motor B, an engine fixed transmission ratio structure 11, a first motor fixed transmission ratio structure 12, a second motor fixed transmission ratio structure 13, a first clutch fixed transmission ratio structure 14, and a second clutch fixed transmission ratio structure 15.

[0032] The first planetary gear set K1 includes a first ring gear 3, a first planetary carrier 4, first planetary gears 5 and a first sun gear 6. The second planetary gear set K2 includes a second ring gear 7, a second planetary carrier 8, second planetary gears 9 and a second sun gear 10.

[0033] The engine fixed transmission ratio structure 11 includes a first gear pair, the first gear pair includes a first driving gear Z 11 and the first driven gear Z 12 The first motor fixed transmission ratio structure 12 includes a second gear pair, the second gear pair includes a second driving gear Z 21 and the second driven gear Z 22 The second motor fixed transmission ratio structure 13 includes a third gear pair, the third gear pair includes a third driving gear Z 31 and the third driven gear Z 32 The first clutch fixed transmission ratio structure 14 includes a fourth gear pair, the fourth gear pair includes a fourth driving gear Z 41 and the fourth driven gear Z 42 The second clutch fixed transmission ratio structure 15 includes a fifth gear pair, the fifth gear pair includes a fifth driving gear Z 51 and the fifth driven gear Z 52 .

[0034] Engine 1 is connected to the first driving gear Z 11 , first driven gear Z 12 The first planet carrier 4 is connected to the first sun gear 6, which is fixed to the sleeve shaft 2. The sleeve shaft 2 is rotatably connected to the connecting shaft 17 through a bearing (not shown). The first ring gear 3 is fixed to the left end of the connecting shaft 17.

[0035] The first motor A is connected to the second driving gear Z 21 (Input end of the first motor fixed transmission ratio mechanism 12). Second driven gear Z 22 (The output end of the first motor fixed transmission ratio mechanism 12 ) is also fixedly connected to the sleeve shaft 2 and is located on the right side of the first sun gear 6 .

[0036] Fourth driving gear Z 41(The input end of the first clutch fixed transmission ratio mechanism 14) is also fixed to the sleeve shaft 2 and is located at the second driven gear Z 22 The right side of the fourth driven gear Z 42 (The output end of the first clutch fixed transmission ratio mechanism 14) is connected to the first active end CL1 of the dual clutch mechanism.

[0037] The second motor B is connected to the third driving gear Z 31 , the third driven gear Z 32 The first motor A and the second motor B are both motors with driving / generating working states. Specifically, the first motor A and the second motor B are both permanent magnet synchronous motors.

[0038] The second gear ring 7 is also fixed to the sleeve shaft 2 and is located on the fourth driving gear Z 41 The left end of the second planetary carrier 8 is fixedly connected to the right end of the connecting shaft 17, and the right end of the second planetary carrier 8 is connected to the fifth driving gear Z 51 , the fifth driven gear Z 52 The second active end CL2 of the dual clutch mechanism is connected. The passive ends of the dual clutch mechanism are both connected to the drive axle 16.

[0039] Reference Figure 6 and Figure 7 The embodiment of the present application can realize three basic hybrid operation modes, and the speed of each moving component is continuous between the modes. Specifically, Figure 6 This is the speed relationship diagram for forward working condition. Figure 7 For Figure 6 Based on the above, the reverse gear working range is added, and the pure electric mode replaces part of the working range of the input split mode in the starting phase. In addition, the short process of engine startup is taken into account, and finally a speed relationship diagram of the multi-mode working scheme in the full speed range is formed. The dotted line in the figure represents the speed of the first motor A and the output speed ω out The dotted line represents the relationship between the speed of the second motor B and the output speed, and the solid line represents the relationship between the speed of the engine and the output speed.

[0040] The first planetary gear K1, the second planetary gear K2, and the dual clutch mechanism together constitute the planetary gear mechanism. The planetary gear mechanism is used to achieve power coupling between the engine 1 and the first motor A and the second motor B. By manipulating the dual clutch mechanism, the three operating modes of input split, compound split, and fixed transmission ratio can be switched. In addition, in addition to the three basic hybrid operating modes of input split mode, compound split mode, and fixed transmission ratio mode, the embodiment of the present application can also achieve a pure electric mode. The three mode switching logic is shown in Table 1:

[0041] Table 1

[0042]

[0043] The working principle of the embodiment of this application is as follows:

[0044] Reference Figure 2 When the vehicle is in input-split mode, the first active end CL1 of the dual-clutch mechanism is engaged, and the second active end CL2 is disengaged. Power from engine 1 enters first planetary carrier 4 via engine fixed gear ratio structure 11. A portion of the power from first planetary carrier 4 flows through first ring gear 3 and second planetary carrier 8 before entering second sun gear 10. This power is then coupled with a portion of the power from first motor A via first motor fixed gear ratio structure 12 and second ring gear 7. The coupled power then flows through second motor B via second motor fixed gear ratio structure 13 for power generation.

[0045] The remaining power from first planetary carrier 4 is coupled via first sun gear 6 and the power from first motor fixed gear ratio arrangement 12 to drive axle 16 via first clutch fixed gear ratio arrangement 14, thereby driving the vehicle. In this operating mode, engine 1 is operating, first motor A is driving, and second motor B is generating electricity. This operating mode is suitable for high-speed operation.

[0046] Reference Figure 3 When the vehicle is in compound-split mode, the first active end CL1 of the dual-clutch mechanism is disengaged, and the second active end CL2 of the dual-clutch mechanism is engaged. Power from engine 1 enters first planetary carrier 4 via engine fixed gear ratio structure 11. A portion of the power from first planetary carrier 4 enters second planetary carrier 8 via first ring gear 3.

[0047] Another part of the power from the first planetary carrier 4 enters the second planetary carrier 8 after passing through the first sun gear 6 and the second ring gear 7 .

[0048] The power from the first motor A passes through the first motor fixed transmission ratio structure 12 and the second ring gear 7 and then enters the second planetary carrier 8.

[0049] The power from the second motor B passes through the second motor fixed transmission ratio structure 13 and the second sun gear 10 and then enters the second planetary carrier 8 .

[0050] After the four powers entering the second planetary carrier 8 are coupled with each other, they flow into the drive axle 16 through the second clutch fixed transmission ratio structure 15 and the second active end CL2 of the dual clutch mechanism to drive the vehicle.

[0051] Under this working condition, the engine 1 is working, the first motor A is driving, and the second motor B is driving.

[0052] Reference Figure 4When the vehicle is in fixed gear ratio mode, the first and second active ends CL1 and CL2 of the dual-clutch mechanism are engaged, and second motor B stops rotating. Power from engine 1 enters first planetary carrier 4 via engine fixed gear ratio structure 11. A portion of the power from first planetary carrier 4 passes through first ring gear 3 and enters second planetary carrier 8. This power is then coupled with the power from first motor A via first motor fixed gear ratio structure 12 and second ring gear 7. The coupled power then flows through second clutch fixed gear ratio structure 15 and the second active end CL2 of the dual-clutch mechanism to drive axle 16, thereby driving the vehicle.

[0053] Another part of the power from the first planetary carrier 4 is coupled through the first sun gear 6 and part of the power from the first motor fixed transmission ratio structure 12 through the first clutch fixed transmission ratio structure 14 and the first active end CL1 of the dual clutch mechanism into the drive axle 16 for driving the vehicle.

[0054] Under this working condition, the engine 1 is running, the first motor A is driving, and the second motor B is stopped.

[0055] Reference Figure 5 When the vehicle is in pure electric mode, the first active terminal CL1 of the dual-clutch mechanism is engaged, and the second active terminal CL2 of the dual-clutch mechanism is disengaged. Power from the first motor A flows sequentially through the first motor fixed gear ratio structure 12, the first clutch fixed gear ratio structure 14, and the first active terminal CL1 of the dual-clutch mechanism into the drive axle 16 to propel the vehicle. In this operating mode, the first motor A serves as the drive motor, while the second motor B idles.

[0056] In addition, when the vehicle is in reverse gear, the engine 1 stops, the first motor A is driven, and the second motor B is idling, which can also start the engine 1. At this time, the system is in pure electric mode.

[0057] Reference Figure 6 and Figure 7 The speed of each moving component remains constant between the various modes in this embodiment of the present application. The above schematic diagram assumes that the engine 1 maintains a constant speed in both power split modes. The speed continuity relationship shown at the transition between these modes is guaranteed, and can therefore serve as a reference for determining the conditions for mode switching and speed control in subsequent control strategies.

[0058] In addition, in theory, each mode can achieve brake energy recovery, and the specific implementation plan varies depending on the application scenario.

[0059] The above are only specific embodiments of the present application, but the scope of protection of the present application is not limited thereto. Any changes or replacements within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A multi-mode power split hybrid powertrain system, characterized in that: It includes an engine, a first motor, a second motor, a dual clutch mechanism, a drive axle, a first planetary gear, a second planetary gear, an engine fixed transmission ratio structure, a first motor fixed transmission ratio structure, a second motor fixed transmission ratio structure, a first clutch fixed transmission ratio structure, and a second clutch fixed transmission ratio structure; The first planetary gear set includes a first ring gear, a first planet carrier, a first sun gear, and a first planetary gear; the second planetary gear set includes a second ring gear, a second planet carrier, a second sun gear, and a second planetary gear; the first sun gear, the output end of the first motor fixed transmission ratio mechanism, the input end of the first clutch fixed transmission ratio mechanism, and the second ring gear are fixedly connected; The engine is connected to the first planet carrier via an engine fixed transmission ratio structure; the first ring gear and the second planet carrier are fixedly connected; The first motor is connected to an input end of the first motor fixed transmission ratio mechanism; The second motor is connected to the second sun gear via a second motor fixed transmission ratio structure; The output end of the first clutch fixed transmission ratio mechanism is connected to the first active end of the dual clutch mechanism; the second planetary carrier is connected to the second active end of the dual clutch mechanism through the second clutch fixed transmission ratio structure; the passive end of the dual clutch mechanism is connected to the drive axle; The first sun gear, the output end of the first motor fixed transmission ratio mechanism, the input end of the first clutch fixed transmission ratio mechanism and the second ring gear are all fixedly connected to the sleeve shaft; the sleeve shaft is rotatably connected to the connecting shaft; the first ring gear is fixedly connected to the first end of the connecting shaft; and the second planet carrier is fixedly connected to the second end of the connecting shaft.

2. The multi-mode power split hybrid powertrain system according to claim 1, characterized in that: The engine fixed gear ratio structure includes a first gear pair.

3. The multi-mode power split hybrid powertrain system according to claim 1, wherein: The first motor fixed transmission ratio structure includes a second gear pair.

4. The multi-mode power split hybrid powertrain system according to claim 1, wherein: The second motor fixed transmission ratio structure includes a third gear pair.

5. The multi-mode power split hybrid powertrain system according to claim 1, characterized in that: The first clutch fixed gear ratio structure includes a fourth gear pair.

6. The multi-mode power split hybrid powertrain system according to claim 1, wherein: The second clutch fixed gear ratio configuration includes a fifth gear pair.

7. The multi-mode power split hybrid powertrain system according to claim 1, wherein: The first motor and the second motor are both motors with driving / generating working states.

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