Drive system for a hybrid electric vehicle and process

Abstract

A hybrid electric vehicle comprising a battery, an internal combustion engine, a first electric motor which can be operated as a generator, and at least one second electric motor, characterized in that the internal combustion engine can be operated in such a way that it runs at a defined operating point and the mechanical energy generated by the internal combustion engine is selectively transferred at least partially directly, without a transmission, to a main drive axle of the hybrid electric vehicle and / or at least partially to the generator for conversion into electrical energy for feeding into the battery, wherein the generator can be switched by means of a control unit so that it can operate as an additional drive means for the main drive axle if required, wherein the second electric motor is configured to drive a second drive axle of the hybrid electric vehicle.

Description

[0001] The technical field of the invention is hybrid electric vehicles and methods for using them.

[0002] The state of the art in hybrid electric vehicles encompasses various solutions for optimizing energy consumption and drive performance. Known systems often combine combustion engines and electric motors to provide drive energy flexibly.

[0003] US 2018 / 0354354 A1 discloses a front-engine, extended-range electric passenger vehicle comprising a turboshaft engine, a battery pack, an electric generator, drive motors, a storage tank, and an independent regenerator, wherein the turboshaft engine is mounted on frames above a front axle and an axis of an output shaft of the turboshaft engine lies on a plane of symmetry of the vehicle body, a rotor of the electric generator and the output shaft of the turboshaft engine are connected to each other, the battery pack is mounted on frames between the front and rear axles, the drive motors drive the front and rear wheels to rotate, the storage tank is mounted on frames in front of and near the rear axle, and the storage tank is configured to store liquefied natural gas, compressed natural gas, or fuel oil for use by the turboshaft engine.and the independent regenerator is located below the turboshaft engine and is used to preheat the intake air of the turboshaft engine using exhaust gas expelled from it.

[0004] US 2022 / 0185261 A1 discloses a device for controlling the drive of an electric all-wheel drive vehicle at the time of shifting, comprising the following: a front-wheel drive train comprising an internal combustion engine, a front-wheel motor and a transmission configured to switch the power of the internal combustion engine and the front-wheel motor and output the switched power to the front wheels; a rear-wheel drivetrain comprising a rear-wheel motor and a retarder configured to delay the power of the rear-wheel motor and deliver the delayed power to the rear wheels; and a controller configured to, when the transmission shifting begins while driving by means of the internal combustion engine, command the rear-wheel motor to deliver a portion of the power requested by the rider equal to the power that can be delivered by the rear-wheel motor, and command the front-wheel motor to deliver power obtained by subtracting the power requested by the rider from the power ordered to the rear-wheel motor, the output power of the internal combustion engine, and the engine output power.

[0005] CN 107521353 A discloses an electric car with an enlarged engine displacement and belongs to the field of electric vehicle technology. The electric car with an enlarged engine displacement comprises an on-board power supply system, a battery pack, and a drive system, wherein the motor, generator, and transformer box of the on-board power supply system are installed in the front deck of the electric car with an enlarged engine displacement; the battery pack is located in the lower section on the floor of the electric car with an enlarged engine displacement; the motor of the drive system is located in the rear deck of the electric car with an enlarged engine displacement; the generator is electrically connected to the transformer box, and the transformer box is electrically connected to the battery pack and the motor, respectively, and the battery pack is electrically connected to the motor.

[0006] The object of the invention is to provide a hybrid electric vehicle that enables high energy efficiency, reduced emissions and flexible driving operation through an optimized drive architecture.

[0007] The invention relates to a drive system for a hybrid electric vehicle comprising a battery, an internal combustion engine, a first electric motor which can be operated as a generator, and at least one second electric motor, wherein the internal combustion engine can be operated such that it runs at a defined operating point and the mechanical energy generated by the internal combustion engine is selectively transferred at least partially directly, without a transmission, to a main drive axle of the hybrid electric vehicle and / or at least partially to the generator for conversion into electrical energy for feeding into the battery. The generator can be switched by means of a control unit so that it operates as an additional drive means for the main drive axle when required, while the second electric motor is configured to drive a second drive axle of the hybrid electric vehicle.

[0008] The battery is an electrical energy storage device that supplies power to the electric motors and can be recharged as needed. The internal combustion engine is a power machine that generates mechanical energy and operates at a defined point to ensure optimal performance and efficiency. The first electric motor can operate as a generator, converting electrical energy for storage in the battery, and can also serve as an additional drive for the main axle when required. The second electric motor is designed to drive the second axle, for example, a front axle, thus providing improved traction and power. The main axle, for example, a rear axle, is the primary axle through which the vehicle is propelled.The control unit is a central control unit that manages the operating modes of the combustion engine and the generator, thus enabling optimal adaptation to driving conditions.

[0009] By directly transferring mechanical energy from the combustion engine to the main drive axle without a gearbox, the vehicle's efficiency is increased and energy loss is minimized. The switchable generator allows for the provision of additional drive power when needed, increasing the flexibility of the drive system and supporting the vehicle under changing power demands.

[0010] Advantageously, in a purely electric mode, the battery can supply energy to the first electric motor and at least the second electric motor for electric driving, with the combustion engine switched off and the drive power transferred directly from the first electric motor to the main drive axle and from the second electric motor to the second drive axle without a transmission. The purely electric mode allows for emission-free operation of the hybrid electric vehicle or the vehicle as a whole and utilizes the stored electrical energy in the battery for propulsion.

[0011] This enables the electric mode of the hybrid electric vehicle, whereby the combustion engine remains switched off and the vehicle is powered entirely by electric energy, thus reducing emissions.

[0012] Advantageously, the first electric motor and the combustion engine can be arranged on a common axis of the main drive axle. This arrangement enables a compact design, which facilitates direct energy transfer to the main drive axle and makes the energy flow efficient.

[0013] This enables a direct and efficient power transmission from the combustion engine and the first electric motor to the main drive axle, optimizing the vehicle's drive performance and reducing the space required.

[0014] Advantageously, the vehicle's drive system control unit can be configured to automatically adjust the defined operating point of the combustion engine depending on driving conditions, battery charge level, and driving mode. The control unit continuously analyzes external conditions and the battery charge level and adjusts the combustion engine's operating point accordingly.

[0015] This ensures that the combustion engine always operates at its optimal operating point depending on external conditions and the battery's state of charge, thereby optimizing fuel consumption and extending the combustion engine's operating time.

[0016] Advantageously, the vehicle's drive mode can be automatically switched between pure electric operation, generator operation, and a combined hybrid operation using both the combustion engine and electric motor, depending on the desired speed, fuel consumption, and / or power output of the hybrid electric vehicle. This automatic switching of drive modes adapts the vehicle's energy requirements to the driving conditions and desired operating parameters.

[0017] This allows the hybrid electric vehicle to efficiently switch between different operating modes depending on the requirements, increasing adaptability to different driving conditions and further optimizing energy consumption.

[0018] Another object of the invention is a hybrid electric vehicle with a drive system according to the invention as described above.

[0019] A further object of the invention is a method for using the drive system described above for a hybrid electric vehicle comprising the following steps: operating the combustion engine at a defined operating point to generate mechanical energy, transferring the generated mechanical energy at least partially directly, without a transmission, to a main drive axle of the hybrid electric vehicle and / or at least partially to the generator for conversion into electrical energy which is fed into the battery, automatically switching the first electric motor, if required, into an additional drive mode for the main drive axle, so that the first electric motor acts as a drive means, wherein the second electric motor drives the second drive axle.

[0020] This process efficiently controls the energy flow between the combustion engine, generator and battery, directing the additional drive power to the main drive axle when needed, thus improving the flexibility and performance of the hybrid electric vehicle.

[0021] Advantageously, the hybrid electric vehicle can be operated in an electric driving mode in which the battery provides energy to the first and at least one secondary electric motor, while the combustion engine is switched off and the drive power is transmitted directly to the main drive axle and the secondary drive axle without a transmission. The electric driving mode ensures that only the battery's electrical energy is used for propulsion and that the combustion engine produces no emissions in this mode.

[0022] This enables emission-free operation of the hybrid electric vehicle, with the electric mode transferring the drive power to the main and second drive axles without using the combustion engine and without a gearbox, thus contributing to a reduction in environmental impact.

[0023] Advantageously, the defined operating point of the combustion engine can be automatically adjusted by the control unit of the hybrid electric vehicle's drive system, depending on driving conditions and the battery's state of charge. The control unit continuously monitors the current driving conditions and the battery's state of charge, and adjusts the combustion engine's operating point to optimize the drive system's performance and efficiency.

[0024] This ensures that the combustion engine always operates at the defined operating point under changing driving conditions, which reduces fuel consumption and extends the engine's service life.

[0025] Advantageously, the control unit can automatically switch the drive mode between a purely electric operating mode, a generator operating mode, and a combined hybrid operating mode, depending on the desired speed, consumption, and / or power output of the hybrid electric vehicle. The control unit selects the appropriate mode according to the specific driving requirements and the vehicle's operating objectives.

[0026] This allows the hybrid electric vehicle to be flexibly adapted to different driving situations, thereby minimizing energy consumption and optimizing range by using the most efficient mode in each case.

[0027] Advantageously, the control unit of the hybrid electric vehicle's drive system can be configured to automatically switch between different drive modes based on navigation data and external conditions such as gradients or outside temperature, in order to optimize energy consumption and vehicle efficiency. The control unit takes navigation data and environmental factors, such as the outside temperature, into account to precisely adjust the vehicle's operating mode.

[0028] This increases the efficiency of the hybrid electric vehicle through an optimized selection of drive modes, as the vehicle selects the ideal drive mode based on navigation data and external conditions, resulting in extended range and reduced fuel consumption.

[0029] The hybrid electric vehicle can therefore utilize a cost-effective drive architecture and flexibly adapt its driving modes to cover various performance requirements and speeds, for example, from 0 to 180 km / h. The combustion engine can constantly generate a defined amount of energy, while excess energy is fed into the battery via the generator. In driving situations requiring higher performance, such as overtaking or speeds above 120 km / h, the generator can be switched to a mode where it acts as an additional drive motor and no longer functions as a generator.

[0030] The battery of the hybrid vehicle's drive system can be a high-voltage battery which, in combination with one or more electric motors, an internal combustion engine, and a motor that can be operated as a generator, completely replaces a transmission component of a conventional internal combustion engine-powered vehicle. This configuration therefore requires only a connection between the internal combustion engine and the main drive axle, preferably located on the rear axle, so that the generated mechanical energy can be transferred directly to the rear wheels.The combustion engine operates exclusively at an optimal operating point, the power of which is controlled via the generator: If the resistance of the generator increases, the power to the wheels of the main drive axle is throttled accordingly; if the generator switches to idle, all the energy of the combustion engine is transferred to the wheels of the main drive axle without loss.

[0031] In one embodiment of the method according to the invention, at low speeds below 30 km / h, the vehicle is switched to "Electric Only" mode, in which only the electric motor on the second drive axle or on the front axle operates and the battery provides the energy supply. This mode can also be activated manually by the driver to enable emission-free operation. At speeds below the optimal operating point of the combustion engine, for example at 40 km / h, a "Generate and Drive" mode can be activated, in which the combustion engine provides energy for 60 km / h and the generator creates resistance so that only the energy required for 40 km / h is transferred to the wheels.

[0032] In a further embodiment of the method according to the invention, a "Generate and Drive and Boost" mode is activated in driving situations requiring all-wheel drive, for example in off-road conditions or snow. This mode allows the combustion engine to supply kinetic energy for 60 km / h, while the battery provides additional electrical energy to meet the requirements of the all-wheel drive at lower speeds.

[0033] In a further embodiment of the method according to the invention, a "boost and drive" mode is used at speeds above 60 km / h, whereby the generator is switched to idle and the energy of the combustion engine is transferred directly to the wheels. Additionally, the battery can provide supplementary power to the second electric motor on the second drive axle or on the front axle as needed.

[0034] In a further embodiment of the method according to the invention, a "Full Power" mode is activated for high power requirements, in which the generator is reversed and used as an additional electric motor to provide more power. In this mode, an increased amount of electrical energy is drawn from the battery to maximize the drive power at both the front and rear axles.

[0035] In a further embodiment of the method according to the invention, an "Electric Only High Speed" mode is used for drivers who wish to achieve a higher speed in the purely electric "Electric Only" mode. In this mode, the generator can also be operated as an additional electric motor, and the second electric motor can drive the second drive axle, so that the battery's energy can be used for balanced all-wheel drive.

[0036] The vehicle can therefore utilize a comprehensive energy management system via the control unit, which monitors and controls the core components, including the battery, generator, and second electric motor. It can continuously consider external conditions, internal battery parameters such as the state of charge and / or temperature, as well as the driver's preferences to optimize energy use. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] US 2018 / 0354354 A1

[0003] US 2022 / 0185261 A1

[0004] CN 107521353 A

[0005]

Claims

[1] Drive system for a hybrid electric vehicle comprising a battery, an internal combustion engine, a first electric motor which can be operated as a generator and at least one second electric motor, characterized by , that the combustion engine can be operated in such a way that it runs at a defined operating point and the mechanical energy generated by the combustion engine is optionally transferred at least partially directly, without a transmission, to a main drive axle of the hybrid electric vehicle and / or at least partially to the generator for conversion into electrical energy for feeding into the battery, wherein the generator can be switched by means of a control unit so that it can operate as an additional drive means for the main drive axle if required, wherein the second electric motor is configured to drive a second drive axle of the hybrid electric vehicle. [2] Drive system according to claim 1, wherein in a purely electric mode the battery ensures the energy supply of the first electric motor and the at least one second electric motor for electric driving operation, wherein the internal combustion engine is switched off and the drive power is transferred from the first electric motor directly without transmission to a main drive axle and from the second electric motor to the second drive axle. [3] Drive system according to one of the preceding claims, wherein the first electric motor and the internal combustion engine are arranged on a common axis of the main drive axle. [4] Drive system according to one of the preceding claims, wherein the control unit is configured to automatically adjust the defined operating point of the internal combustion engine depending on driving conditions, a battery charge level and a driving mode. [5] Drive system according to one of the preceding claims, wherein a drive mode of the vehicle automatically switches between a pure electric operating mode, a generator operating mode and a combined hybrid operating mode by means of the control unit, depending on a desired speed, a desired consumption and / or a desired power of the hybrid electric vehicle. [6] Hybrid electric vehicle with a drive system according to any one of claims 1 to 5. [7] Method for using a drive system according to any one of claims 1 to 5 for a hybrid electric vehicle, comprising the steps: Operating the internal combustion engine at a defined operating point to generate mechanical energy, The transmission of the generated mechanical energy, at least partially directly, without a gearbox, to a main drive axle of the hybrid electric vehicle and / or at least partially to the generator for conversion into electrical energy that is fed into the battery, and an automatic switching of the first electric motor, if required, into an additional drive mode for the main drive axle, so that the first electric motor acts as a drive means, with the second electric motor driving the second drive axle. [8] Method according to claim 7, wherein the hybrid electric vehicle is operated in an electric driving mode in which the battery ensures the energy supply of the first and at least one second electric motor, while the internal combustion engine is switched off and the drive power is transferred to the main drive axle and the second drive axle without a transmission. [9] Method according to claim 7 or 8, wherein the defined operating point of the internal combustion engine is automatically adjusted by the control unit depending on driving conditions and the battery charge level. [10] Method according to any one of claims 7 to 9, wherein the drive mode automatically switches between a purely electric operating mode, a generator operating mode and a combined hybrid operating mode by means of the control unit, depending on a desired speed, a desired consumption and / or a desired power of the hybrid electric vehicle and / or wherein the control unit of the hybrid electric vehicle is configured to automatically switch between different drive modes depending on navigation data and external conditions such as gradients or outside temperature in order to optimize the energy consumption and efficiency of the vehicle.