A single-path continuously variable transmission vehicle hybrid drive system

Abstract

This invention discloses a single-path continuous transmission hybrid vehicle drive system. The system includes an internal combustion engine system, a drive motor, a transmission mechanism, drive wheels, a battery system, and a control system. The internal combustion engine system includes an engine, the output shaft of which is coaxially connected to the motor shaft of the drive motor. The motor shaft drives the drive wheels via the transmission mechanism. The battery system is connected to the drive motor, and the control system is communicatively connected to both the internal combustion engine system and the battery system. During vehicle operation, the engine's output power must be transmitted to the drive wheels via the drive motor, and this power transmission path remains a single path throughout the vehicle's operation. This invention avoids a power transmission path that allows the engine's output power to bypass the drive motor and directly transmit to the drive wheels. By constructing a single power transmission path, it avoids the energy loss and structural complexity problems caused by the multi-path allocation and switching in traditional hybrid systems.

Description

Technical Field

[0001] This invention relates to the field of vehicle hybrid drive technology, and more particularly to a single-path continuous transmission vehicle hybrid drive system. Background Technology

[0002] Hybrid electric vehicles are vehicles that use multiple energy sources, typically a conventional engine (ICE) using liquid fuel and an electric motor using electrical energy. Existing hybrid vehicles mostly adopt parallel, power-split, or multi-motor drive structures, usually including clutches, planetary gears, or other power distribution mechanisms, resulting in complex power paths, high mechanical losses, complex control strategies, and energy losses and smoothness issues during power switching.

[0003] In the prior art, patent CN213948120U discloses a coaxial hybrid drive system and vehicle, belonging to the field of hybrid vehicles. This coaxial hybrid drive system includes: an engine; a first motor; a main input shaft connected to both the engine and the first motor, the main input shaft having a first input gear and a disengagement device, the disengagement device controlling whether power from the engine and the first motor is transmitted to the first input gear; a main output shaft having a first output gear and a main reduction gear, the first output gear meshing with the first input gear, and the main reduction gear meshing with a differential gear; and a second motor, poweredly connected to the output shaft, with the output shaft of the second motor coaxially arranged with the main input shaft. The coaxial hybrid drive system and vehicle of this invention can improve vehicle fuel economy and are easy to integrate into vehicles.

[0004] Patent CN117841962A discloses a torsional vibration cancellation method and a hybrid power system for a DHT hybrid system. The DHT hybrid system includes a motor and an engine, with the motor rotor rigidly connected to the engine crankshaft. A torsional vibration damping mechanism is provided at the motor's output end. The torsional vibration cancellation method includes: obtaining the engine's torque output function; determining a pulsation function based on the torque output function; establishing a torsional vibration cancellation function for the cancellation torque, where the superposition value of the cancellation torque and the engine torque pulsation is equal to or close to 0; calculating the required cancellation torque based on the torsional vibration cancellation function during engine and motor operation, thereby determining the corresponding cancellation torque command for the motor, and superimposing the cancellation torque command onto the output control of the motor during normal operation. This invention can reduce torque and speed fluctuations in the hybrid system, resulting in lower system cost and weight, while achieving vibration and noise levels close to or even better than traditional DHT hybrid systems.

[0005] Patent CN102481835B discloses a system for electric power management in a hybrid electric vehicle, comprising an engine, a first inverter, a first motor coupled to the engine and the first inverter, and a first transmission coupled between the engine and the first motor. The first transmission has a transmission speed ratio operable such that the first motor operates at a speed independent of the engine operating speed. A second motor is coupled to a second inverter and the axle of the vehicle. A high-voltage battery is coupled to both the first and second inverters. A switch box is disposed between the first and second motors. The switch box contains a switch adapted to open and close to allow a direct electrical connection from the first motor to the second motor.

[0006] In order to solve one of the above problems, this application provides a vehicle hybrid drive system with single-path continuous transmission. Summary of the Invention

[0007] The purpose of this invention is to solve the problems existing in the prior art by proposing a single-path continuous transmission vehicle hybrid drive system.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: a single-path continuous transmission vehicle hybrid drive system, comprising an internal combustion engine system, a drive motor, a transmission mechanism, a battery system, and a control system. The internal combustion engine system includes an engine, whose output power is transmitted to the drive motor via a single path, with the engine output shaft coaxially connected to the drive motor shaft. Furthermore, there is no actively or passively controlled torque transmission interruption device between the output shaft and the motor shaft. The motor shaft drives the drive wheels via the transmission mechanism. The battery system is connected to the drive motor, and the control system is communicatively connected to both the internal combustion engine system and the battery system. During vehicle operation, the engine output power must be transmitted to the drive wheels via the drive motor, and the power transmission path remains continuously single and unchanging throughout vehicle operation. That is, the engine output power cannot directly act on the drive wheels through other transmission paths, and there is no independent transmission mechanism within the vehicle that would allow the engine output power to bypass the drive motor and directly transmit to the drive wheels.

[0009] Furthermore, the internal combustion engine system described above is configured to control engine fuel injection and ignition.

[0010] Furthermore, as described above, the drive motor is arranged on the longitudinal center line of the vehicle.

[0011] Furthermore, as described above, the battery system is arranged longitudinally along the vehicle and locked by a locking component. That is, the installation position of the battery system can be adjusted once during the vehicle assembly stage according to the target front and rear axle load distribution. After the adjustment is completed, it is locked by a fixing mechanism so that the front and rear axle load distribution of the vehicle is close to the preset optimized ratio range, and the battery position remains fixed during vehicle operation.

[0012] Furthermore, the battery system described above includes a battery and a battery charge / discharge management component. The battery's mounting position is adjustable and locked by a locking component. The battery charge / discharge management component is communicatively connected to the control system and controls the battery's operating state.

[0013] Furthermore, as described above, the engine and drive motor are rigidly connected or have no controllable separation function, and there is no control device that can actively or passively interrupt power transmission during the power transmission process.

[0014] Furthermore, as described above, the control system controls the drive motor to actively adjust or compensate for the drag torque and torque fluctuations generated by the single-path power transmission, and to suppress vibration, so as to ensure the continuity of power transmission and driving smoothness.

[0015] Furthermore, as described above, the transmission mechanism includes a commutator and multiple drive shafts, with the drive shafts connecting to the drive wheels. The number of commutators is one or two, corresponding to common front-wheel drive, rear-wheel drive, or four-wheel drive structures, respectively.

[0016] Furthermore, as described above, the output shaft and the motor shaft are rigidly connected.

[0017] Furthermore, as described above, the output shaft and the motor shaft are connected by a coupling.

[0018] Furthermore, under any operating condition of the vehicle, the engine output power is transmitted to the drive wheels through the drive motor, and there are no other parallel or alternative power transmission paths.

[0019] Compared with the prior art, the beneficial effects of the present invention are: By constructing a single power transmission path, the energy loss and structural complexity problems caused by the multi-path allocation and switching of traditional hybrid vehicles can be avoided. The power transmission structure is more unified by eliminating the transmission path that can bypass the drive motor; The adjustable and locking design of the battery mounting position optimizes the axle load distribution of the entire vehicle, improving driving stability and handling performance. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of an embodiment of the present invention; Figure 2This is a schematic diagram of the power transmission path of the present invention; Figure 3 This is the overall control system of the present invention.

[0021] In the diagram: 1. Engine; 2. Drive motor; 3. Transmission mechanism; 4. Drive wheel. Detailed Implementation

[0022] In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0023] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "fixed," "installed," "connected," "set," etc., should be interpreted broadly. For example, when an element is said to be "fixed to" another element, it can be directly on the other element or there may be an intervening element. When an element is said to be "installed" on another element, it can be directly installed on the other element or there may be an intervening element. When an element is said to be "connected" to another element, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within the two elements.

[0024] Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] The present invention discloses a single-path continuous transmission hybrid power drive system. This vehicle hybrid power drive system includes an internal combustion engine system, a drive motor 2, a transmission mechanism 3, drive wheels 4, a battery system, and a control system. The internal combustion engine system includes an engine 1, whose output shaft is coaxially connected to the motor shaft of the drive motor 2. That is, the engine 1 and drive motor 2 form a single power transmission path through a direct connection or an equivalent transmission structure (such as a rigid connection such as a coupling). The motor shaft drives the drive wheels 4 via the transmission mechanism 3, which includes a commutator and multiple drive shafts connected to the drive wheels 4. Therefore, the power output from the engine 1 must be transmitted to the drive wheels 4 via the drive motor 2 during vehicle operation, and this path is continuously maintained during vehicle operation. No independent transmission structure is provided within the vehicle to allow the power output from the engine 1 to bypass the drive motor 2 and be directly transmitted to the drive wheels 4, thus ensuring the uniqueness of the power transmission path. Furthermore, the drive motor 2 is preferably positioned at the longitudinal symmetrical centerline of the vehicle, which is beneficial for the symmetrical arrangement of the overall vehicle structure and the optimization of power transmission efficiency.

[0027] Furthermore, the battery system is connected to the drive motor 2, and the control system is communicatively connected to both the internal combustion engine system and the battery system. The control system controls the drive motor 2 to actively adjust or compensate for the drag torque and torque fluctuations generated by the single-path power transmission, and to suppress vibrations, ensuring continuous power transmission and smooth driving. The battery system is arranged longitudinally along the vehicle, and its installation position can be adjusted once during vehicle assembly according to vehicle model parameters and target front and rear axle load distribution, and locked by a locking assembly. During normal vehicle use, the battery position remains fixed, supplying power to the drive motor 2, thereby optimizing the axle load distribution of the entire vehicle. The control system coordinates the operating state of the drive motor 2, but under any driving vehicle operating condition, the power output of the engine 1 is transmitted to the drive wheels 4 through the drive motor 2, and there are no other parallel or alternative power transmission paths. Its working principle and feasibility are as follows: 1. Structural Principles Engine 1 and drive motor 2 form a single power transmission path via a rigid coupling or direct connection. The power output from engine 1 must be transmitted to drive wheels 4 via drive motor 2 during vehicle operation. The system does not include a clutch or any other power separation / switching mechanism. This structure fundamentally eliminates the energy loss and control complexity caused by multi-path switching and complex mechanical coupling in traditional hybrid systems.

[0028] 2. Feasibility description for low-speed and coasting conditions During low-speed start-up, driving, or coasting, the control system can control the internal combustion engine system, causing engine 1 to stop fuel injection and ignition. Engine 1 is passively towed by drive motor 2 only through the power path. This towing loss accounts for a small proportion of the vehicle's total energy consumption and has a limited impact on the overall fuel economy. At this time, the resistance of engine 1 is mainly mechanical friction and a small amount of compression loss. Drive motor 2 actively outputs a small positive compensation torque to offset the towing resistance, and can switch to energy recovery mode during coasting or braking.

[0029] Due to the relatively limited towing power and the high compensation efficiency of drive motor 2, the system can still operate stably under this condition without significantly affecting the vehicle's driving function, demonstrating good engineering feasibility.

[0030] 3. Efficiency description under medium- and high-speed cruise conditions (key point) Under conditions where fuel consumption is high, such as during medium-to-high-speed cruising, engine 1 can operate stably within a preset high-efficiency MAP range (e.g., the high-efficiency combustion zone of 1500-2200 rpm). Drive motor 2 is mainly responsible for load fine-tuning, torque smoothness compensation, and vibration suppression. Due to the single power transmission path and the absence of additional mechanical switching components, transmission chain losses are low, which helps improve the overall energy utilization efficiency of the system.

[0031] Compared to traditional power-split hybrid systems (which suffer from power-split losses such as planetary gears), this system has a more direct transmission path under the premise of steady-state and efficient operation of engine 1, which is conducive to improving fuel economy.

[0032] 4. Working principle under dynamic operating conditions Under conditions of acceleration or rapid load changes, drive motor 2 quickly outputs positive regulating torque to compensate for the dynamic response lag of engine 1. At the same time, engine 1 maintains a relatively stable and efficient speed, without directly participating in large transient adjustments. This decoupled control ensures both smoothness and speed of acceleration response, while reducing the time engine 1 operates in the inefficient range, which is beneficial for overall fuel consumption control.

[0033] 5. Comparison with existing technologies Compared with existing hybrid power systems that include clutches, disengagement devices, planetary gears, or multi-path power distribution structures, this invention eliminates all power separation and switching mechanisms, forming a continuous, single, rigid power path. This results in a simpler structure, more unified control, fewer sources of mechanical loss, and potential efficiency advantages under medium- and high-speed steady-state conditions.

[0034] Example 1 (Basic Parameter Example) Reference Figure 1-3As shown, the present invention discloses a single-path continuous transmission vehicle hybrid drive system suitable for mid-size SUVs. Specific parameters are as follows: Engine 1 is a 1.5L naturally aspirated four-cylinder engine with a rated power of 80kW and an efficient range of 1500-2200rpm; Drive motor 2 is a permanent magnet synchronous motor with a rated power of 120kW and a peak power of 200kW, directly coaxially connected to engine 1 via a rigid coupling; The power path is engine 1 → drive motor 2 → transmission shaft → main reducer → wheels, without clutch, planetary gears, or bypass; The battery is an 8kWh lithium iron phosphate battery, longitudinally arranged, and fixed by locking components after position adjustment during vehicle assembly; The vehicle's curb weight is approximately 1800kg, and the drag coefficient is 0.28.

[0035] During low-speed start-up and coasting, engine 1 stops fuel injection and ignition, while drive motor 2 is responsible for vehicle propulsion and outputs a small amount of compensating torque to offset the drag resistance of engine 1. During medium- and high-speed cruising, engine 1 operates stably in its high-efficiency range, and drive motor 2 mainly performs load adjustment and torque smoothing compensation. Due to the single path, transmission losses are low.

[0036] Example 2 (Optimized Example for Medium-to-High-Speed ​​Cruise) Reference Figure 1-3 As shown, based on the technical solution of Embodiment 1, a single-path continuous transmission vehicle hybrid drive system is provided. The high-efficiency range of engine 1 is set at 1600-2100 rpm. Under medium-to-high-speed cruising conditions (60-120 km / h), engine 1 maintains a stable speed and load, while drive motor 2 mainly undertakes fine-tuning and torque compensation functions, resulting in low transmission losses. Due to the single power transmission path and the absence of additional mechanical switching components, the overall energy loss of the system is low, which is beneficial to improving fuel economy.

[0037] Example 3 (Low Speed ​​and Energy Recovery Optimization Example) Reference Figure 1-3 As shown, based on the technical solution of the above embodiments, a single-path continuous transmission vehicle hybrid drive system focuses on low-speed / coasting scenarios, with a battery capacity of 8kWh. During low-speed start-up, pure electric driving, and coasting, engine 1 stops fuel injection and ignition, and drive motor 2 is responsible for driving and actively compensates for the engine 1's drag resistance with torque compensation. During coasting and braking, drive motor 2 switches to energy recovery mode to meet basic external discharge needs. Even considering battery life management (actual usable capacity is approximately 4kWh), it can still meet basic external discharge needs (such as outdoor camping lighting and low-power electrical appliance use).

[0038] The above three embodiments, based on the single, non-disconnectable power transmission path structure and working principle of this technical solution, illustrate the system operation under different working conditions. Simulation analysis shows that, under the steady-state efficient operation of engine 1 and the effect of a single transmission path, this system exhibits a good fuel economy trend in major fuel-consuming conditions such as medium-to-high-speed cruising. The specific improvement and overall performance under low-speed conditions require precise quantitative verification through further vehicle system simulation, bench testing, or real-vehicle testing.

[0039] Example 4 (Low Drag Optimization Example) Reference Figure 1-3 As shown, based on the technical solution of the above embodiment, a single-path continuous transmission vehicle hybrid drive system is provided. A passive unidirectional overtaking connection structure is added between the engine 1 and the drive motor 2. This structure is a type of "rigid connection" and is a "connection structure without controllable separation function." It has no electronically controlled / hydraulic active clutch capability, only achieving forward rigid locking and reverse passive idling. The power path is engine 1 → passive unidirectional overtaking structure → drive motor 2 → transmission mechanism 3 → wheel, with a unique path and no bypass. Under driving conditions, the unidirectional structure is rigidly locked, and the engine 1 and drive motor 2 are rigidly directly connected, with continuous power transmission. Under coasting conditions, the unidirectional structure passively idles, eliminating the drag resistance of engine 1 without changing the uniqueness of the power transmission path. During control engagement, the drive motor 2 outputs a small positive torque to restore locking, with no controllable separation action throughout the entire process. This embodiment retains all core functions, reduces coasting energy consumption, and improves smoothness.

[0040] In the device of the present invention, the assembly and cooperation relationship of the various components, the engine 1, the drive motor 2, the battery, and the control system are existing technologies or materials, and the relevant technical personnel can directly purchase or order them from the market according to the required product model and specifications.

[0041] All electrical components mentioned in the text are connected to the main controller, which can be a conventional known device such as a computer that plays a control role.

[0042] The above description is merely a preferred embodiment of the present invention, and common knowledge regarding specific structures and characteristics in the solutions is not described in detail here. It will be apparent to those skilled in the art that the present invention is not limited to the details of the above embodiments, and that the present invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered exemplary and non-limiting in all respects. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this invention, based on the technical solutions and inventive concepts of the present invention, should be covered within the protection scope of this invention.

Claims

1. A single-path continuous transmission vehicle hybrid drive system, the vehicle hybrid drive system comprising an internal combustion engine system, a drive motor (2), a transmission mechanism (3), drive wheels (4), a battery system, and a control system, characterized in that, The internal combustion engine system includes an engine (1), the output shaft of the engine (1) is coaxially connected to the motor shaft of the drive motor (2), and the motor shaft drives the drive wheel (4) to work via a transmission mechanism (3); The battery system is connected to the drive motor (2), and the control system is communicatively connected to the internal combustion engine system and the battery system respectively; The power output of the engine (1) must be transmitted to the drive wheel (4) via the drive motor (2) during vehicle operation, and the power transmission path remains a single path during vehicle operation. At the same time, the hybrid drive system of the vehicle does not have a power transmission path that allows the power output of the engine (1) to bypass the drive motor (2) and be directly transmitted to the drive wheel (4).

2. A single-path continuous transmission vehicle hybrid drive system according to claim 1, characterized in that, The internal combustion engine system is configured to control the fuel injection and ignition of the engine (1).

3. The vehicle hybrid drive system with single-path continuous transmission according to claim 1, characterized in that, The drive motor (2) is arranged on the longitudinal symmetrical center line of the vehicle.

4. A vehicle hybrid drive system with single-path continuous transmission according to claim 1, characterized in that, The battery system is arranged longitudinally along the vehicle and its position is adjusted during the vehicle assembly stage according to the target front and rear axle load distribution. After the adjustment is completed, it is locked by a locking component and remains fixed during vehicle operation.

5. A single-path continuous transmission vehicle hybrid drive system according to claim 1, characterized in that, The engine (1) and the drive motor (2) are rigidly connected or have no controllable separation function, and there is no control device that can actively or passively interrupt the power transmission during the power transmission process.

6. A vehicle hybrid drive system with single-path continuous transmission according to claim 1, characterized in that, The control system controls the drive motor (2) to actively adjust or compensate for the drag torque and torque fluctuations generated by the single-path power transmission, and to suppress vibration, so as to ensure the continuity of power transmission and smooth driving.

7. A single-path continuous transmission vehicle hybrid drive system according to claim 1, characterized in that, The transmission mechanism (3) includes a commutator and multiple transmission shafts, which are connected to drive wheels (4).

8. A vehicle hybrid drive system with single-path continuous transmission according to claim 1, characterized in that, The output shaft and the motor shaft are rigidly connected.

9. A single-path continuous transmission vehicle hybrid drive system according to claim 8, characterized in that, The output shaft of the drive motor (2) is connected to the transmission mechanism (3) via a coupling.

10. A vehicle hybrid drive system with single-path continuous transmission according to claim 1, characterized in that, Under any operating condition of the vehicle, the power output of the engine (1) is transmitted to the drive wheel (4) through the drive motor (2), and there are no other parallel or alternative power transmission paths.

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