Electric vehicles and electro-hydraulic hybrid drive systems

Abstract

The present invention belongs to the field of automobiles, and discloses an electric vehicle and an electro-hydraulic hybrid drive system, which includes a central controller, a battery pack, a reducer, an electro-hydraulic integrated machine connected to the reducer, a valve group assembly, and an accumulator, wherein the electro-hydraulic integrated machine includes a motor housing assembly and a rotor assembly, a stator assembly, and a first hydraulic pump / motor assembly contained in the motor housing assembly, and the electro-hydraulic hybrid drive system has the function of operating in a pure electric mode, a pure hydraulic mode, and an electro-hydraulic hybrid mode, and the electro-hydraulic hybrid drive system can be used for two-wheel drive and four-wheel drive electric vehicles. The electro-hydraulic hybrid drive system of the present invention has the characteristics of compact structure, long cruising range, long battery life, can meet the needs of electric vehicles for high power density and high energy density, and uses different modes according to different working conditions.

Description

Technical Field

[0001] The present invention belongs to the field of automobiles, and in particular relates to an electro-hydraulic hybrid power drive system with different drive modes and brake energy recovery modes, and a two-wheel drive or four-wheel drive electric vehicle comprising the drive system. Background Art

[0002] Pure electric vehicles and hybrid electric vehicles can effectively achieve energy conservation and emission reduction of vehicles, and are increasingly valued by people, becoming the most important research direction of new energy vehicles. At present, countries around the world have formulated timetables for stopping the sale of fuel vehicles. For example, the countries that have announced a ban on the sale of fuel vehicles from 2025 to 2040 include China, the United States, France, Germany, Japan, the Netherlands, India, the United Kingdom, Sweden, Canada and other 20 to 30 major countries. The world's major automobile manufacturers have also announced their respective timetables for stopping the production of traditional fuel vehicles.

[0003] Batteries and power drive systems are the most critical core technologies for electric vehicles. Figure 1 The figure shows an existing electric vehicle power drive system, including a battery pack 110, a drive motor 2, a reducer 20, a differential, a controller, etc., wherein the reducer and the differential are often assembled on the housing, the drive motor rotates at high speed to output speed and torque, and transmits mechanical energy to the drive wheel through the speed reduction and torque increase effect of the reducer assembly. This power drive system has the following shortcomings: (1) Endurance bottleneck. Since it is difficult to make a major breakthrough in battery technology in a short period of time, compared with traditional fuel vehicles, its endurance is still difficult to meet the public's demand for long-range. For example, Tesla's flagship Model S pure electric vehicle has a maximum endurance of more than 500km on the highway after a single charge, but this is achieved under the condition of a constant speed of 90km / h with a liquid-cooled high-energy lithium battery with an energy of 85KW, and does not exceed 300km under the condition of urban roads. (2) The power requirements of the motor for acceleration and normal driving do not match. In order to ensure that the electric vehicle has a short acceleration time of 100 kilometers during acceleration, a very powerful drive motor needs to be configured. For example, in order to achieve strong acceleration performance comparable to traditional sports cars such as Porsche (acceleration time of 4-5s from 0 to 100 kilometers), Tesla's flagship Model S pure electric vehicle needs to be equipped with a drive motor with a power of up to 300kw. However, the average propulsion power requirement of the vehicle at a speed of 90km / h does not exceed 10kw, plus 50% transmission chain loss and accessory power does not exceed 15kw, which is only 5% to 6% of the peak power of the drive motor. Therefore, it causes huge waste. The motor power is low and the energy consumption is high. At the same time, the short-term strong current during rapid acceleration increases the thermal load and power consumption of the battery, shortens the mileage of the electric vehicle, and reduces the service life of the battery; or adopts Figure 2Another existing powerful electric vehicle, a four-wheel drive electric vehicle, is shown in the figure. That is, an independent power drive system is set on the front and rear drive axles. The two power drive systems will inevitably increase the cost of the whole vehicle, occupy the chassis space, reduce the battery capacity, and increase the complexity and coordination of the whole vehicle control system. (3) Braking energy recovery bottleneck. Recovering and reusing braking energy is an important measure to improve the range of electric vehicles. However, the ability and efficiency of traditional batteries and electric drive systems to reversely transmit power and store energy instantly are poor, and the storage energy is limited. Generally, electric vehicles can only recover 10-15% of the braking energy, and the control is complicated. More importantly, the frequent charging and discharging of the battery increases the load and impact of the battery and motor, and reduces the service life of the battery. Summary of the invention

[0004] The purpose of the present invention is to provide a new type of electric-hydraulic hybrid drive system with compact structure, long driving range, long battery life, and meeting the requirements of high power density and high energy density, and a two-wheel drive or four-wheel drive electric vehicle including the drive system in order to address the problems existing in electric vehicle technology.

[0005] The technical solution of the present invention is implemented as follows: the electric-hydraulic hybrid drive system of the present invention comprises a central controller, a reducer, an electric-hydraulic integrated machine connected to the reducer, a valve group assembly and an accumulator, the electric-hydraulic integrated machine comprises a motor housing assembly and a motor assembly accommodated in the motor housing assembly, a first hydraulic pump / motor assembly, the motor housing assembly is provided with a valve group assembly, the accumulator is connected to the valve group assembly, and the electric-hydraulic hybrid drive system comprises:

[0006] a. Working in pure electric mode, that is, completely receiving the electrical energy of the battery pack and converting it into mechanical energy, or converting mechanical energy into the electrical energy of the battery pack;

[0007] b. Working in pure hydraulic mode, that is, completely receiving the hydraulic energy of the accumulator and converting it into mechanical energy, or converting mechanical energy into the hydraulic energy of the accumulator;

[0008] c. Working in an electro-hydraulic hybrid mode, that is, the electrical energy of the battery pack and the hydraulic energy of the accumulator are converted into mechanical energy, or the mechanical energy is converted into the electrical energy of the battery pack and the hydraulic energy of the accumulator.

[0009] The two-wheel-drive electric vehicle including the electro-hydraulic hybrid drive system described in the present invention comprises a battery pack, a drive axle and a differential. The reducer and differential assembly are on the reducer housing. The differential is respectively connected to the left and right half shafts of the drive axle and drives the wheels to move. The drive axle is arranged in a driving front axle or a driving rear axle.

[0010] The two-wheel-drive electric vehicle comprising the electro-hydraulic hybrid drive system of the present invention comprises a motor controller, a valve assembly controller, and an inverter. The central controller and the motor controller, the valve assembly controller, and the inverter can realize information transmission and control. The central controller realizes different drive mode controls according to different signal inputs:

[0011] a. In pure electric drive mode, the battery pack drives the motor assembly of the electric-hydraulic integrated machine through the inverter, and transmits mechanical energy to the drive wheels through the reducer and differential;

[0012] b. Pure hydraulic drive mode, the first hydraulic pump / motor assembly of the electro-hydraulic integrated machine works in the motor working condition, the central controller controls the valve group assembly so that the high-pressure oil of the accumulator is input to the first hydraulic pump / motor assembly to work, and then the mechanical energy is transmitted to the driving wheels through the reducer and the differential;

[0013] c. In the electric-hydraulic hybrid driving mode, the battery pack and the accumulator drive the motor assembly and the first hydraulic pump / motor assembly of the electric-hydraulic integrated machine to work respectively, and then transmit the mechanical energy to the driving wheels through the reducer and the differential;

[0014] The two-wheel-drive electric vehicle comprising the electric-hydraulic hybrid drive system of the present invention, wherein the method in which the central controller controls the drive system to switch between different drive modes comprises:

[0015] a. Determine whether the battery SOC value is less than the minimum working setting value. If it is less than the minimum working setting value, the vehicle cannot be started and the battery needs to be charged. If the SOC value is greater than the minimum working setting value, the vehicle can be started;

[0016] b. Determine whether the accumulator pressure is less than the minimum working pressure setting value. If it is less than the minimum working pressure setting value, the accumulator cannot participate in the driving process, the battery pack drives the motor assembly of the electric-hydraulic integrated machine, and the vehicle enters the pure electric driving mode;

[0017] c. If the accumulator pressure is higher than the minimum working pressure setting value, it is determined whether the driving force provided by the first hydraulic pump / motor assembly of the electro-hydraulic integrated machine can provide the driving force required for vehicle acceleration or starting. If it is sufficient, the vehicle is driven by the first hydraulic pump / motor assembly only by the high-pressure oil released by the accumulator, and the vehicle enters a pure hydraulic drive mode; if it is insufficient, the vehicle is driven by the battery pack and the accumulator together to drive the electro-hydraulic integrated machine, and the vehicle enters an electro-hydraulic hybrid drive mode.

[0018] The two-wheel-drive electric vehicle including the electro-hydraulic hybrid drive system of the present invention includes a motor controller, a valve assembly controller, and an inverter. The central controller and the motor controller, the valve assembly controller, and the inverter can realize information transmission and control. The central controller realizes different braking energy recovery mode controls according to different signal inputs:

[0019] a. In the pure electric braking energy recovery mode, the central controller controls the motor assembly of the electric-hydraulic integrated machine to be in a power generation state through the motor controller, and the kinetic energy of the vehicle is transmitted to the motor assembly through the differential and the reducer. The motor assembly generates electrical energy under the action of electromagnetic induction and charges the battery pack through the inverter;

[0020] b. In pure hydraulic brake energy recovery mode, the central controller controls the accumulator to be in a liquid-filled state through the valve group assembly controller, and the kinetic energy of the vehicle is transmitted to the first hydraulic pump / motor assembly of the electric-hydraulic integrated machine through the differential and the reducer. The first hydraulic pump / motor assembly works in a pumping condition, and the generated high-pressure oil is delivered to the accumulator;

[0021] c. In the electric-hydraulic hybrid braking energy recovery mode, the motor assembly of the electric-hydraulic integrated machine is in a power generation state, the first hydraulic pump / motor assembly works in a pumping state, the accumulator is in a liquid-filled state, and the kinetic energy of the vehicle is transmitted to the electric-hydraulic integrated machine through the differential and the reducer. The electric-hydraulic integrated machine generates electrical energy and hydraulic energy, which are stored in the battery pack and the accumulator respectively;

[0022] The two-wheel-drive electric vehicle comprising the electro-hydraulic hybrid drive system of the present invention, wherein the method for the central controller to control the electro-hydraulic hybrid drive system to switch between different braking energy recovery modes comprises:

[0023] a. Determine whether the accumulator pressure is higher than the maximum working pressure setting value. If it is higher than the maximum working pressure setting value, the accumulator cannot participate in the braking energy recovery process, and the kinetic energy of the vehicle is transmitted to the electric-hydraulic integrated machine through the differential and the reducer. The motor component of the electric-hydraulic integrated machine generates electrical energy under the action of electromagnetic induction and charges the battery pack through the inverter, and the vehicle enters the pure electric braking energy recovery mode;

[0024] b. If the pressure of the accumulator is less than the maximum working pressure setting value, it is determined whether the braking force provided by the first hydraulic pump / motor assembly meets the braking force required by the vehicle. If so, the kinetic energy of the vehicle is transmitted to the electro-hydraulic integrated machine through the differential and the reducer. The first hydraulic pump / motor assembly of the electro-hydraulic integrated machine works in a pump condition and generates high-pressure oil, which is delivered to the accumulator, and the vehicle enters a pure hydraulic brake energy recovery mode;

[0025] c. If the braking force provided by the first hydraulic pump / motor assembly cannot meet the braking force required by the vehicle, it is determined whether the battery SOC value is greater than the maximum working setting value. If the battery SOC value is greater than the maximum working setting value, the battery pack cannot be charged, and the vehicle enters a pure hydraulic braking energy recovery plus friction braking mode. If the battery SOC value is less than the maximum working setting value, the kinetic energy of the vehicle is transmitted to the electro-hydraulic integrated machine through the differential and the reducer. The electro-hydraulic integrated machine generates electrical energy and hydraulic energy, which are stored in the battery pack and the accumulator respectively, and the vehicle enters an electro-hydraulic hybrid braking energy recovery mode.

[0026] The four-wheel-drive electric vehicle including the electro-hydraulic hybrid drive system described in the present invention comprises a battery pack, a shifting system, a first drive axle, a second drive axle, a differential and a second hydraulic pump / motor. The electro-hydraulic hybrid drive system is arranged on the first drive axle, and the second hydraulic pump / motor is connected to the left and right half shafts of the second drive axle through the differential and drives the second wheel to move.

[0027] The four-wheel-drive electric vehicle comprising the electro-hydraulic hybrid drive system described in the present invention comprises a battery pack, a shifting system, a first drive axle, a wheel-side reducer and a second hydraulic pump / motor. The electro-hydraulic hybrid drive system is arranged on the first drive axle, and the second hydraulic pump / motor is connected to the drive hub through two wheel-side reducers or is directly arranged in the drive hub and drives the wheels to move.

[0028] The four-wheel drive electric vehicle including the electro-hydraulic hybrid drive system of the present invention includes a motor controller, a shift controller, a valve assembly controller and an inverter. The central controller and the motor controller, the shift controller, the valve assembly controller and the inverter can realize information transmission and control. The central controller realizes the control of different drive modes of the drive system according to different signal inputs:

[0029] a. In pure electric drive mode, the battery pack drives the motor assembly of the electric-hydraulic integrated machine through the inverter, and transmits mechanical energy to the first wheel through the reducer and the differential. The central controller controls the valve assembly to unload the first hydraulic pump / motor assembly, the shift system is in an engaged state, and the vehicle is in a two-wheel drive state;

[0030] b. In pure hydraulic drive mode, the first hydraulic pump / motor assembly of the electro-hydraulic integrated machine operates in the motor working condition, the central controller controls the valve group assembly so that the high-pressure oil of the accumulator drives the first hydraulic pump / motor assembly to work, and / or the high-pressure oil of the accumulator drives the second hydraulic pump / motor to work, and the vehicle is in a two-wheel drive state;

[0031] d. Electro-hydraulic hybrid drive mode. The battery pack drives the motor assembly of the electro-hydraulic integrated machine through the inverter, and drives the first hydraulic pump / motor assembly of the electro-hydraulic integrated machine to work under the pump working condition. The output high-pressure oil drives the second hydraulic pump / motor to work so as to transfer mechanical energy to the second wheel. The shift system is in the disconnected state, and the vehicle is in the two-wheel drive state.

[0032] Alternatively, the battery pack drives the electric-hydraulic integrated machine to work through an inverter, and the electric-hydraulic integrated machine outputs mechanical energy and hydraulic energy, wherein the mechanical energy is transmitted to the first wheel through a speed reducer and a differential, and the hydraulic energy is transmitted to the second wheel through a second hydraulic pump / motor, the shift system is in an engaged state, and the vehicle is in a four-wheel drive state;

[0033] Alternatively, the battery pack drives the motor assembly of the electro-hydraulic integrated machine alone and transmits the load to the first wheel through the reducer and the differential. The first hydraulic pump / motor assembly of the electro-hydraulic integrated machine is unloaded, and the accumulator drives the second hydraulic pump / motor alone and transmits the load to the second wheel, and the vehicle is in four-wheel drive state.

[0034] The four-wheel drive electric vehicle comprising the electro-hydraulic hybrid drive system of the present invention, wherein the method for the central controller to control the electro-hydraulic hybrid drive system to switch between different drive modes comprises:

[0035] a. Determine whether the battery SOC value is less than the minimum working setting value. If it is less than the minimum working setting value, the vehicle cannot be started and the battery needs to be charged. If the SOC value is greater than the minimum working setting value, the vehicle can be started;

[0036] b. Determine whether the accumulator pressure is less than the minimum working pressure setting value. If it is less than the minimum working pressure setting value, the accumulator cannot participate in the driving process, the battery pack drives the electric-hydraulic integrated machine, and the vehicle enters the pure electric driving mode;

[0037] c. If the accumulator pressure is higher than the minimum working pressure setting value, it is determined whether the driving force provided by the first hydraulic pump / motor assembly / or the second hydraulic pump / motor can provide the driving force required for vehicle acceleration or starting. If it is sufficient, the high-pressure oil released by the accumulator drives the first hydraulic pump / motor assembly to work, and / or the high-pressure oil released by the accumulator drives the second hydraulic pump / motor to work, and the vehicle enters a pure hydraulic drive mode; if it is insufficient, the battery pack and the accumulator jointly drive the electric-hydraulic integrated machine and / or the second hydraulic pump / motor to work, and the vehicle enters an electric-hydraulic hybrid drive mode.

[0038] The four-wheel drive electric vehicle including the electro-hydraulic hybrid drive system of the present invention includes a motor controller, a shift controller, a valve assembly controller and an inverter. The central controller and the motor controller, the shift controller, the valve assembly controller and the inverter can realize information transmission and control. The central controller realizes the control of different braking energy recovery modes of the drive system according to different signal inputs:

[0039] a. In the pure electric braking energy recovery mode, the central controller controls the motor assembly of the electric-hydraulic integrated machine to be in a power generation state through the motor controller, and the kinetic energy of the vehicle is transmitted to the electric-hydraulic integrated machine through the differential and the reducer. The motor assembly of the electric-hydraulic integrated machine generates electric energy under the action of electromagnetic induction and charges the battery pack through the inverter;

[0040] b. In pure hydraulic braking energy recovery mode, the central controller controls the accumulator to be in a liquid-filled state through the valve group assembly, the kinetic energy of the vehicle is transmitted to the electro-hydraulic integrated machine through the differential and the reducer, the first hydraulic pump / motor assembly of the electro-hydraulic integrated machine is in a pumping state and generates high-pressure oil, and the high-pressure oil is delivered to the accumulator;

[0041] Alternatively, the kinetic energy of the vehicle is transmitted to the second hydraulic pump / motor through the reducer, the second hydraulic pump / motor is in a pumping state and generates high-pressure oil, and the high-pressure oil is delivered to the accumulator;

[0042] Alternatively, the kinetic energy of the first wheel is transmitted to the first hydraulic pump / motor assembly of the electro-hydraulic integrated machine through the differential and the reducer to generate high-pressure oil, and the kinetic energy of the second wheel is transmitted to the second hydraulic pump / motor through the reducer to generate high-pressure oil, and the high-pressure oil is delivered to the accumulator;

[0043] c. In the electro-hydraulic hybrid braking energy recovery mode, the motor assembly of the electro-hydraulic integrated machine is in a power generation state, the first hydraulic pump / motor assembly operates in a pumping state, and the accumulator is in a liquid-filled state. The kinetic energy of the first wheel is transmitted to the motor assembly of the electro-hydraulic integrated machine through the differential and the reducer to generate electrical energy independently and store it in the battery pack. The kinetic energy of the second wheel is generated by the second hydraulic pump / motor to generate hydraulic energy independently and store it in the accumulator.

[0044] The four-wheel drive electric vehicle comprising the electro-hydraulic hybrid drive system of the present invention, wherein the method for the central controller to control the electro-hydraulic hybrid drive system to switch between different braking energy recovery modes comprises:

[0045] a. Determine whether the accumulator pressure is higher than the maximum working pressure setting value. If it is higher than the maximum working pressure setting value, the accumulator cannot participate in the braking energy recovery process, and the kinetic energy of the vehicle is transmitted to the electric-hydraulic integrated machine through the differential and the reducer. The motor component of the electric-hydraulic integrated machine generates electrical energy under the action of electromagnetic induction and charges the battery pack through the inverter, and the vehicle enters the pure electric braking energy recovery mode;

[0046] b. If the pressure of the accumulator is less than the maximum working pressure setting value, it is determined whether the braking force provided by the first hydraulic pump / motor assembly and / or the second hydraulic pump / motor of the electro-hydraulic integrated machine meets the braking force required by the vehicle. If so, the kinetic energy of the vehicle is converted into hydraulic energy through the first hydraulic pump / motor assembly and / or the second hydraulic pump / motor of the electro-hydraulic integrated machine and stored in the accumulator, and the vehicle enters the pure hydraulic braking energy recovery mode;

[0047] c. If the braking force provided by the first hydraulic pump / motor assembly and the second hydraulic pump / motor cannot meet the braking force required by the vehicle, determine whether the battery SOC value is greater than the maximum working setting value. If the battery SOC value is greater than the maximum working setting value, the battery pack cannot be charged, and the vehicle enters a pure hydraulic braking energy recovery plus friction braking mode. If the battery SOC value is less than the maximum working setting value, the vehicle's kinetic energy generates electrical energy and / or hydraulic energy through the electro-hydraulic integrated unit, or the electro-hydraulic integrated unit generates electrical energy alone and the second hydraulic pump / motor generates hydraulic energy alone, and the electrical energy and hydraulic energy are stored in the battery pack and the accumulator, respectively, and the vehicle enters an electro-hydraulic hybrid braking energy recovery mode.

[0048] Based on the above technical solution, the beneficial effects of the present invention are:

[0049] (1) The present invention integrates the hydraulic pump / motor, electric motor, controller, accumulator and other devices into a highly integrated whole, which has the characteristics of compact structure and small size. Under the same volume conditions, two different power systems are configured, which can replace the technical solution that originally requires two independent power drive systems; at the same time, the compact layout also leaves enough space for the battery to ensure that the battery has sufficient capacity; the drive system of the present invention can be used for both bridge drive and wheel side drive, which simplifies the chassis layout, making the chassis layout more flexible. This layout advantage is particularly significant in four-wheel drive electric vehicles.

[0050] (2) The present invention optimizes the power matching of the electric motor and improves the battery working condition. By utilizing the fast energy discharge characteristic of the accumulator, the electric vehicle can be guaranteed to have strong acceleration performance when starting without significantly increasing the power configuration of the drive motor. Therefore, the power of the drive motor during starting and normal driving is similar, which reduces the technical requirements for the drive motor, avoids the impact of short-term high current on the battery during high power output, and improves the service life and safety of the battery. Therefore, the electric-hydraulic hybrid drive system of the present invention can meet the requirements of electric vehicles for high power density and high energy density.

[0051] (3) Improved cruising range. The present invention integrates the hydraulic pump / motor, motor, controller, accumulator and other devices into a highly integrated whole. The braking energy can be recovered and utilized by the accumulator alone or in combination with the battery. The maximum recovery rate of braking energy is as high as 70-80%. Therefore, without increasing the battery capacity, the cruising range of electric vehicles can be significantly improved. This electric-hydraulic hybrid drive system that stores energy through the accumulator is particularly suitable for family cars, city buses, city off-road vehicles, city special vehicles (such as municipal electric garbage trucks, sweepers, cleaning vehicles, road maintenance vehicles, etc.), and city logistics transport vehicles that often travel on urban roads.

[0052] (4) Various working modes and convenient control. The hydraulic pump, motor, controller, accumulator and other devices are highly integrated in the present invention. The power distribution of mechanical energy and hydraulic energy can be achieved by adjusting the angle of the swash plate, and the output of hydraulic energy alone or the simultaneous output of mechanical energy and hydraulic energy can be achieved by adjusting the opening and closing of the shifting system. At the same time, it also has pure electric, pure hydraulic, electric-hydraulic hybrid drive and brake energy recovery modes. The conversion between various working modes can be controlled by the central controller, which is convenient and easy to control. It can be used for two-wheel drive or four-wheel drive electric vehicles and can be adjusted according to different road conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 The invention is a power drive system of an existing two-wheel drive electric vehicle.

[0054] Figure 2 The invention is a power drive system of an existing four-wheel drive electric vehicle.

[0055] Figure 3 This is the electric-hydraulic hybrid drive system of the present invention.

[0056] Figure 4 The invention relates to an electric-hydraulic hybrid power drive axle assembly.

[0057] Figure 5 The invention relates to a two-wheel drive electric-hydraulic hybrid electric vehicle.

[0058] Figure 6The invention relates to a bridge-type four-wheel drive electric-hydraulic hybrid electric vehicle.

[0059] Figure 7 The present invention is a bridge-type + wheel-side four-wheel drive electric-hydraulic hybrid vehicle.

[0060] Figure 8 It is a framework diagram of the two-wheel drive electric-hydraulic hybrid drive system of the present invention.

[0061] Fig. 9 for Figure 8 Schematic diagram of the system in pure electric drive mode.

[0062] Fig.10 for Figure 8 Schematic diagram of the system in pure hydraulic drive mode.

[0063] Fig.11 for Figure 8 Schematic diagram of the system in electro-hydraulic hybrid drive mode.

[0064] Fig.12 for Figure 8 System schematic in pure electric braking mode.

[0065] Fig.13 for Figure 8 Schematic diagram of the system in pure hydraulic braking mode.

[0066] Fig.14 for Figure 8 Schematic diagram of the system in electro-hydraulic hybrid braking mode.

[0067] Fig.15 It is a framework diagram of the four-wheel drive electric-hydraulic hybrid drive system of the present invention.

[0068] Fig.16 for Fig.15 Schematic diagram of the system in pure electric drive mode.

[0069] Fig.17 for Fig.15 Schematic diagram of the system in pure hydraulic drive mode.

[0070] Fig.18 for Fig.15 System diagram of the first embodiment in the electro-hydraulic hybrid driving mode.

[0071] Fig.19 for Fig.15 A schematic diagram of the system of the second embodiment in the electric-hydraulic hybrid driving mode.

[0072] Fig. 20 for Fig.15 A schematic diagram of the system of the third embodiment in the electric-hydraulic hybrid driving mode.

[0073] Fig.21 for Fig.15 System schematic in pure electric braking mode.

[0074] Fig. 22 for Fig.15 System diagram of the first embodiment in pure hydraulic braking mode.

[0075] Fig.23 for Fig.15 System diagram of the second embodiment in pure hydraulic braking mode.

[0076] Fig.24 for Fig.15 System diagram of the third embodiment in pure hydraulic braking mode.

[0077] Fig.25 for Fig.15 Schematic diagram of the system in electro-hydraulic hybrid braking mode.

[0078] Fig.26 The figure is a flow chart of the conversion of the electric-hydraulic hybrid drive system in different drive modes in the present invention.

[0079] Fig. 27 The figure is a flow chart of the conversion of the electric-hydraulic hybrid drive system in different braking modes in the present invention.

[0080] Markings in the figure: 1 is an electric-hydraulic hybrid drive system, 10 is an electric-hydraulic integrated machine, 11 is a motor housing assembly, 12 is a rotor assembly, 13 is a stator assembly, 14 is a first hydraulic pump / motor assembly, 15 is an end seat, 16 is a main shaft, 17 is a rotating drum, 18 is a cylinder body, 19 is a distribution plate, 20 is a reducer, 21 is a front housing of the reducer, 22 is a rear housing of the reducer, 23 is an input shaft assembly, 24 is an intermediate shaft assembly, 25 is an output shaft assembly, 31 is a differential, 32 is a left half shaft, 33 is a right half shaft, and 34 is a drive axle , 35 is the first drive axle, 36 is the second drive axle, 37 is the wheel-side reducer, 38 is the drive wheel hub, 40 is the second hydraulic pump / motor, 41 is the hydraulic oil pipe, 50 is the accumulator, 61 is the first wheel, 62 is the second wheel, 70 is the shift system, 90 is the valve group assembly, 100 is the central controller, 110 is the battery pack, 120 is the charging interface, 121 is the charging inverter, 130 is the power grid, 200 is the motor controller, 300 is the shift controller, 400 is the valve group assembly controller, and 500 is the inverter. DETAILED DESCRIPTION

[0081] The present invention will be described in detail below in conjunction with the accompanying drawings.

[0082] Although the present invention is susceptible of different forms of embodiments, this specification and the accompanying drawings only disclose some specific forms as examples of the present invention. However, the present invention is not intended to be limited to the described embodiments. The scope of the present invention is given in the appended claims.

[0083] For the convenience of description, the embodiments of the present invention are shown in a typical orientation, which makes the central axis of the electric vehicle horizontally stationary, with the front drive axle side as the left and the rear drive axle side as the right, and the terms "longitudinal", "transverse", "up", "down", "front", "rear", "left", "right", "horizontal", "bottom", "inside" and "outside" used in the description are all used with reference to this position, only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the electric vehicle referred to must have a specific orientation, and a specific orientation structure and operation. It should be understood that the present invention can be manufactured, stored, transported and used in orientations different from the described position.

[0084] Embodiment 1:

[0085] like Figure 3 As shown, an electric-hydraulic hybrid driving system 1 for an electric vehicle is shown, comprising a central controller 100, a reducer 20, and an electric-hydraulic integrated machine 10 connected to the reducer 20, a valve group assembly 90, and an accumulator 50. The electric-hydraulic integrated machine 10 comprises a motor housing assembly 11 and a motor assembly contained in the motor housing assembly, a first hydraulic pump / motor assembly 14, the motor assembly comprises a rotor assembly 12 and a stator assembly 13, a valve group assembly 90 is arranged on the motor housing assembly 11, and the accumulator 50 is connected to the valve group assembly 90. The electric-hydraulic hybrid powertrain has:

[0086] a. Working in pure electric mode, that is, completely receiving the electrical energy of the battery pack 110 and converting it into mechanical energy, or converting mechanical energy into the electrical energy of the battery pack 110;

[0087] b. Working in pure hydraulic mode, that is, completely receiving the hydraulic energy of the accumulator 50 and converting it into mechanical energy, or converting mechanical energy into the hydraulic energy of the accumulator 50;

[0088] c. Working in an electric-hydraulic hybrid mode, that is, the electric energy of the battery pack 110 and the hydraulic energy of the accumulator 50 are converted into mechanical energy, or the mechanical energy is converted into the electric energy of the battery pack 110 and the hydraulic energy of the accumulator 50.

[0089] More specifically, the electro-hydraulic hybrid drive system includes a reducer 20 and an electro-hydraulic integrated machine 10 connected to the reducer 2, the electro-hydraulic integrated machine 10 includes a motor housing assembly 11 and a rotor assembly 12, a stator assembly 13, a first hydraulic pump / motor assembly 14, an end seat 15, a main shaft 16 and a rotor drum 17 accommodated in the motor housing assembly, the first hydraulic pump / motor assembly includes a distribution sliding plate pair, a distribution pair and a plunger pair, the distribution pair includes an end of a cylinder body 18 and a distribution plate 19, the rotor drum 11 is respectively connected to the rotor assembly 12 and the cylinder body 18, the rotor assembly 12 drives the rotor drum 17 and the cylinder body 18 of the first hydraulic pump / motor assembly to rotate under the action of electromagnetic force, and the first hydraulic pump / motor assembly 14 can operate in a pump condition or a motor condition.

[0090] Specifically, the reducer 20 includes a reducer housing assembly and an input shaft assembly 23, an intermediate shaft assembly 24, and an output shaft assembly 25 contained in the reducer housing assembly and arranged in parallel. The reducer housing assembly includes a reducer front housing 21 and a reducer rear housing 22. The end seat 15 and the motor housing assembly are connected to the reducer front housing 21. In particular, the reducer front housing 21 and the reducer rear housing 22 can also be configured as an integrated structure. It can be predicted that the reducer assembly can be a fixed speed ratio reducer or a variable speed ratio transmission. The so-called fixed speed ratio reducer refers to a transmission mechanism with a fixed transmission ratio, that is, the output end speed and the input end speed are in a fixed ratio and cannot be adjusted; the so-called variable speed ratio transmission refers to a transmission mechanism with a variable transmission ratio, that is, the speed ratio of the output end speed to the input end speed is adjustable according to different working conditions by adjusting the internal speed change mechanism.

[0091] like Figure 4 As shown, the assembly structure of the electric-hydraulic hybrid drive system 1 and the drive axle 34 is shown, the two output ends of the differential 31 are connected to the left half shaft 32 and the right half shaft 33 on both sides of the drive axle 34, and the electric-hydraulic integrated machine 10 transmits power to the drive axle 34 through the reducer 20 and the differential 31, and drives the first wheel 61 to move. The drive axle 34 can be set to drive the front axle and / or the rear axle.

[0092] Embodiment 2:

[0093] like Figure 5 As shown, an embodiment of a two-wheel drive electric vehicle including the electro-hydraulic hybrid drive system is shown, which includes a battery pack 100, a drive axle 34, and a differential 31. The reducer 20 and the differential 31 are on the reducer housing. The differential 31 is respectively connected to the left half shaft 32 and the right half shaft 33 of the drive axle 34 and drives the wheels to move. The drive axle 34 can be a front axle drive or a rear axle drive.

[0094] Furthermore, if Figure 8 As shown, it is a block diagram of the drive system of a two-wheel drive electric vehicle, which includes a motor controller 200, a valve assembly controller 400, and an inverter 500. The central controller 100 connected to the battery can be connected to the external charging interface 120, which also includes a charging inverter 121. For example, the charging interface 120 can absorb the electric energy received from the power grid 130 through the plug and socket to charge the battery pack 110. In a specific embodiment, the input power can be the standard 120-240VAC power of the standard socket, or it can be a household power supply. The battery pack 110 can be a lead-acid battery, a nickel-chromium battery, an iron battery or a nickel-metal hydride battery. Preferably, the battery pack is a lithium iron phosphate battery. The central controller 100 and the motor controller 200, the valve assembly controller 400, and the inverter 500 can realize information transmission and control. The signal includes but is not limited to a button signal, a displacement signal of the pedal, a battery signal, a pressure signal of the accumulator, a state signal of the valve group, a state signal of the motor, and input parameters of the sensor, such as external temperature, vehicle speed, oil temperature, ground state parameters, etc.

[0095] It should also be noted that the motor controller 200, the valve assembly controller 400, and the inverter 500 can be set as separate controller elements and connected to the central controller via a CAN bus. At the same time, the motor controller 200, the valve assembly controller 400, and the inverter 500 can also be modules integrated in the central controller 100 to realize corresponding functions.

[0096] Furthermore, the central controller 100 implements control of different driving modes according to various input instructions or signals, and the driving modes include:

[0097] a.Pure electric driving mode. Fig. 9 As shown, the battery pack 110 supplies power to the central controller 100, and the central controller 100 controls the motor controller 200 to work in the manner of an electric motor, and converts it into alternating current through the inverter 500 to drive the motor component of the electro-hydraulic integrated machine 10 to work. The stator component 12 of the electro-hydraulic integrated machine 10 obtains an excitation current. Under the action of electromagnetic force, the rotor component 13 rotates and drives the main shaft 16 to rotate through the drum 17 and the cylinder body 18, outputs torque speed, and further transmits mechanical energy to the drive wheels through the speed reduction and torque increase effect of the reducer 20 and the differential 31. This mode is generally used for starting or normal driving conditions when the accumulator pressure is less than the minimum working pressure setting value.

[0098] b. Pure hydraulic drive mode. Fig.10As shown, the battery pack 110 supplies power to the central controller 100, and the central controller 100 controls the valve group assembly controller 400. The valve group assembly 90 is reversed so that the accumulator can discharge high-pressure oil to the outside. At this time, the stator assembly 12 and the rotor assembly 13 of the electro-hydraulic integrated machine 10 do not work, and the first hydraulic pump / motor assembly 14 works in the motor working condition. The first hydraulic pump / motor assembly 14 drives the main shaft to rotate and output torque speed, and then transmits mechanical energy to the driving wheels through the reducer 20 and the differential 31. This mode is used for starting or low-speed operation when the accumulator pressure is greater than the minimum working pressure setting value;

[0099] c.Electric-hydraulic hybrid drive mode. Fig.11 As shown, the battery pack 110 supplies power to the central controller 100, and the central controller 100 controls the valve group assembly controller 400 and the motor controller 200. The valve group assembly 90 is reversed so that the accumulator can discharge high-pressure oil to the outside. The direct current of the battery pack 110 is converted into alternating current through the inverter 500. The electro-hydraulic integrated machine 10 works in the form of a motor. The stator assembly 12 of the electro-hydraulic integrated machine receives the action of the current. Under the action of the electromagnetic force, the rotor assembly 13 rotates. The high-pressure oil output by the accumulator 50 drives the first hydraulic pump / motor assembly 14 of the electro-hydraulic integrated machine 10 to work in the motor mode. The driving forces of the two are superimposed through the main shaft and then transmitted to the driving wheels through the reducer 20 and the differential 31. This mode is used for the working conditions when the car is accelerated or driving on steep roads.

[0100] Furthermore, if Fig.26 As shown, it is a flow chart of the conversion of an electric vehicle in different driving modes. The method and steps of converting a two-wheel drive electric vehicle in different driving modes include:

[0101] a. Determine whether the battery SOC value is less than the minimum working setting value. If it is less than the minimum working setting value, the vehicle cannot start and the battery needs to be charged. If the SOC value is greater than the minimum working setting value, the vehicle can start and proceed to the next step;

[0102] b. Determine whether the pressure of the accumulator 50 is less than the minimum working pressure setting value. If it is less than the minimum working pressure setting value, the accumulator 50 cannot participate in the driving process, and the motor assembly of the electric-hydraulic integrated machine 10 is driven by the battery pack 110, and the vehicle enters the pure electric driving mode;

[0103] c. If the pressure of the accumulator 50 is higher than the minimum working pressure setting value, it is determined whether the driving force provided by the first hydraulic pump / motor assembly 14 of the electro-hydraulic integrated machine can provide the driving force required for vehicle acceleration or starting. If it is sufficient, the vehicle is driven by the first hydraulic pump / motor assembly 14 only by the high-pressure oil released by the accumulator 50, and the vehicle enters a pure hydraulic drive mode; if it is insufficient, the vehicle is driven by the battery pack 110 and the accumulator 50 together to drive the electro-hydraulic integrated machine, and the vehicle enters an electro-hydraulic hybrid drive mode.

[0104] Furthermore, the central controller 100 can implement different braking energy recovery mode controls according to various input instructions or signals, and the braking energy recovery modes include:

[0105] a. Pure electric braking energy recovery mode. Fig.12 As shown, the central controller 100 controls the motor assembly of the electro-hydraulic integrated machine 10 to be in a power generation state through the motor controller 200, and the kinetic energy of the vehicle is transmitted to the electro-hydraulic integrated machine 10 through the differential 31 and the reducer 20. The motor assembly of the electro-hydraulic integrated machine 10 generates alternating current under the action of electromagnetic induction, which is converted into direct current through the action of the inverter 500 and charges the battery pack 110. This mode is used for the working condition when the pressure of the accumulator 50 is greater than the maximum working pressure setting value. At this time, the accumulator 50 does not participate in the braking energy recovery process;

[0106] b. Pure hydraulic braking energy recovery mode. Fig.13 As shown, the central controller 100 controls the accumulator 50 to be in a liquid-filled state through the valve group assembly controller 400, the kinetic energy of the vehicle is transmitted to the electro-hydraulic integrated machine 10 through the differential 31 and the reducer 20, the first hydraulic pump / motor assembly 14 of the electro-hydraulic integrated machine 10 is in a pumping state and generates high-pressure oil, which is delivered to the accumulator 50. This mode is used for the condition when the pressure of the accumulator 50 is less than the maximum working pressure setting value and the braking force provided by the first hydraulic pump / motor assembly 14 can meet the braking requirements;

[0107] c.Electro-hydraulic hybrid braking energy recovery mode, such as Fig.14As shown, the central controller 100 controls the motor assembly of the electro-hydraulic integrated machine 10 to be in a power generation state, the first hydraulic pump / motor assembly 14 to work in a pumping state, and controls the accumulator 50 to be in a liquid filling state through the valve group assembly controller 400 through the motor controller 200. The kinetic energy of the vehicle is transmitted to the electro-hydraulic integrated machine 10 through the differential 31 and the reducer 20. The stator assembly 12 and the rotor assembly 13 of the electro-hydraulic integrated machine 10 generate electrical energy, and the direct current after the action of the inverter 500 is stored in the battery pack 110. The first hydraulic pump / motor assembly 14 generates high-pressure oil and stores it in the accumulator 50. This mode is used for the conditions where the pressure of the accumulator 50 is less than the maximum working pressure and the battery SOC value is less than the maximum working setting value, and a larger braking force is required;

[0108] Furthermore, if Fig. 27 As shown, it is a flow chart of the conversion of an electric vehicle in different braking modes. The method and steps of converting the two-wheel drive electric vehicle in different braking energy recovery modes include:

[0109] a. Determine whether the accumulator pressure is higher than the maximum working pressure setting value. If it is higher than the maximum working pressure setting value, the accumulator 50 cannot participate in the braking energy recovery process, and the kinetic energy of the vehicle is transmitted to the electric-hydraulic integrated machine 10 through the differential 31 and the reducer 20. The motor component of the electric-hydraulic integrated machine 10 generates electrical energy under the action of electromagnetic induction and charges the battery pack 110 through the inverter 500, and the vehicle enters the pure electric braking energy recovery mode;

[0110] b. If the pressure of the accumulator is less than the maximum working pressure setting value, it is determined whether the braking force provided by the first hydraulic pump / motor assembly 14 meets the braking force required by the vehicle. If so, the kinetic energy of the vehicle is transmitted to the electro-hydraulic integrated machine 10 through the differential 31 and the reducer 20. The first hydraulic pump / motor assembly 14 of the electro-hydraulic integrated machine 10 operates in a pumping condition and generates high-pressure oil, which is delivered to the accumulator 50, and the vehicle enters a pure hydraulic braking energy recovery mode;

[0111] c. If the braking force provided by the first hydraulic pump / motor assembly 14 cannot meet the braking force required by the vehicle, it is determined whether the battery SOC value is greater than the maximum working setting value. If the battery SOC value is greater than the maximum working setting value, the battery pack 110 cannot be charged, and the vehicle enters a pure hydraulic braking energy recovery plus friction braking mode. If the battery SOC value is less than the maximum working setting value, the kinetic energy of the vehicle is transmitted to the electro-hydraulic integrated machine 10 through the differential 31 and the reducer 20. The electro-hydraulic integrated machine 10 generates electrical energy and hydraulic energy, which are stored in the battery pack 110 and the accumulator 50 respectively, and the vehicle enters an electro-hydraulic hybrid braking energy recovery mode.

[0112] It should be noted that both battery and accumulator energy storage braking are regenerative braking. In addition to regenerative braking, in order to ensure braking safety and braking efficiency, this electro-hydraulic hybrid drive system should have a traditional friction braking system. When emergency braking is required, it must also have an anti-lock braking system ABS, and under this working condition, the traditional friction braking system has priority.

[0113] Embodiment 3:

[0114] like Figure 6 , 7 As shown, an embodiment of a four-wheel drive electric vehicle including the electro-hydraulic hybrid drive system is shown.

[0115] One preferred embodiment is a four-wheel drive electric vehicle with front and rear axle drive, such as Figure 6 As shown, the four-wheel drive electric vehicle includes a battery pack 110, a first drive axle 35, a second drive axle 36, a differential 31, and a second hydraulic pump / motor 40. The electro-hydraulic hybrid drive system 1 is arranged on the first drive axle 35, and is connected to the left half shaft 32 and the right half shaft 33 of the first drive axle 35 through the differential 31 to drive the first wheel 61 to move. The second hydraulic pump / motor 40 is connected to the left half shaft 32 and the right half shaft 33 of the second drive axle 36 through the differential 31 and drives the second wheel 62 to move. The second hydraulic pump / motor 40 is connected to the valve group assembly 90 through the hydraulic oil pipe 41.

[0116] Another preferred embodiment is a four-wheel drive electric vehicle with a bridge type + wheel side drive, such as Figure 7 As shown, the four-wheel drive electric vehicle includes a battery pack 110, a shift system 70, a first drive axle 35, a wheel-side reducer 37, and a second hydraulic pump / motor 40. The electro-hydraulic hybrid drive system 1 is arranged on the first drive axle 35. The second hydraulic pump / motor 40 is connected to the drive wheel hub 38 through two wheel-side reducers 37 and drives the second wheel 62 to move. The second hydraulic pump / motor 40 is connected to the valve group assembly 90 through a hydraulic oil pipe 41. It can be predicted that the wheel-side drive structure can also be another structure, that is, the second hydraulic pump / motor 40 is directly arranged in the drive wheel hub 38 and drives the second wheel 62 to move. It can be predicted that the first drive axle 35 can be arranged in a driving front axle or a driving rear axle.

[0117] Furthermore, if Fig.15As shown, it is a block diagram of the driving system of a four-wheel drive electric vehicle. The four-wheel drive electric vehicle also includes a motor controller 200, a shift controller 300, a valve group assembly controller 400, and an inverter 500. The central controller 100 and the motor controller 200, the shift controller 300, the valve group assembly controller 400, and the inverter 500 can realize information transmission and control. The signal includes but is not limited to button signals, pedal displacement signals, battery signals, accumulator pressure signals, valve group status signals, motor status signals, and sensor input parameters, such as external temperature, vehicle speed, oil temperature, ground status parameters, etc.

[0118] Furthermore, the central controller 100 implements different driving mode controls according to various input instructions or signals, and the driving modes include:

[0119] a. Two-wheel drive pure electric drive mode. Fig.16 As shown, the battery pack 110 supplies power to the central controller 100, and the central controller 100 controls the motor controller 200, so that the electro-hydraulic integrated machine 10 works in the motor mode. The direct current of the battery pack 110 is converted into alternating current through the inverter 500 so that the stator assembly 12 of the electro-hydraulic integrated machine 10 obtains the excitation current. Under the action of the electromagnetic force, the rotor assembly 13 rotates and drives the main shaft 16 to rotate through the drum 17 and the cylinder body 18, outputs the torque speed, and transmits the mechanical energy to the first wheel 61 through the reducer 20 and the differential 31. The central controller 100 controls the valve group assembly 90 to unload the first hydraulic pump / motor assembly 14 and does not generate high-pressure oil. Therefore, the second hydraulic pump / motor 40 does not work, and the shift system 70 is in an engaged state. This mode is used for the vehicle starting condition when the pressure of the accumulator 50 is less than the minimum working pressure setting value and the first wheel needs to be driven, such as the second wheel 62 is in a stalled slip condition;

[0120] b. Two-wheel drive pure hydraulic drive mode. Fig.17 As shown, the battery pack 110 supplies power to the central controller 100, and the central controller 100 controls the valve group assembly controller 400. The valve group assembly 90 is reversed so that the accumulator can discharge high-pressure oil to the outside. At this time, the first hydraulic pump / motor assembly 14 of the electro-hydraulic integrated machine works in the motor working condition. The central controller 100 controls the valve group assembly 90 so that the high-pressure oil of the accumulator 50 drives the second hydraulic pump / motor assembly 40 to work, and transmits mechanical energy to the second wheel 62 through the reducer 20 and the differential 31. This mode is used for the vehicle starting or low-speed running condition when the accumulator pressure is greater than the minimum working pressure setting value;

[0121] c. Four-wheel drive electric-hydraulic hybrid drive mode.

[0122] like Fig.18As shown, it is an embodiment of one of the four-wheel drive electric-hydraulic hybrid drive modes, the battery pack 110 supplies power to the central controller 100, and the central controller 100 controls the motor controller 200, so that the electric-hydraulic integrated machine 10 works in the motor mode, and the direct current of the battery is converted into alternating current through the inverter so that the stator assembly 12 of the electric-hydraulic integrated machine 10 obtains the excitation current, and under the action of the electromagnetic force, the rotor assembly 13 rotates and drives the main shaft 16 to rotate through the drum 17 and the cylinder body 18. At this time, the first hydraulic pump / motor assembly 14 of the electric-hydraulic integrated machine works in the pump condition, and the output high-pressure oil drives the second hydraulic pump / motor 40 to work and transmits mechanical energy to the driving wheels, and the shift system 70 is in the disconnected state. This mode is used for the car starting condition when the accumulator pressure is less than the minimum working pressure setting value and the front-wheel drive is required, for example, the first wheel 61 is in a stalled slip condition;

[0123] like Fig.19 As shown, it is another embodiment of the four-wheel drive electric-hydraulic hybrid driving mode, the battery pack 110 supplies power to the central controller 100, the central controller 100 controls the motor controller 200, and the DC power of the battery is converted into AC power through the inverter to make the electric-hydraulic integrated machine 10 work. The electric-hydraulic integrated machine 10 outputs mechanical energy and hydraulic energy, wherein the mechanical energy is transmitted to the first wheel 61 through the reducer 20 and the differential 31, and the hydraulic energy is transmitted to the second wheel 62 through the second hydraulic pump / motor 40, and the shift system 70 is in the engaged state. This mode is used for the vehicle starting condition when the accumulator pressure is less than the minimum working pressure setting value and the front second wheel drive is required;

[0124] Another embodiment of the four-wheel drive electric-hydraulic hybrid drive mode, such as Fig. 20 As shown, the battery pack 110 drives the electric-hydraulic integrated machine 10 to work and output mechanical energy, and transmits it to the first wheel 61 through the reducer 20 and the differential 31. The accumulator 10 drives the second hydraulic pump / motor 40 alone and transmits it to the second wheel 62. This mode is used for the vehicle starting condition when the accumulator pressure is greater than the minimum working pressure setting value and the front second wheel needs to be driven;

[0125] Furthermore, if Fig.26 As shown, it is a flow chart of the conversion of electric vehicles in different driving modes. The method and steps of converting the four-wheel drive electric vehicle in different driving modes include:

[0126] a. Determine whether the battery SOC value is less than the minimum working setting value. If it is less than the minimum working setting value, the vehicle cannot start and the battery needs to be charged. If the SOC value is greater than the minimum working setting value, the vehicle can start and proceed to the next step;

[0127] b. Determine whether the pressure of the accumulator 50 is less than the minimum working pressure setting value. If it is less than the minimum working pressure setting value, the accumulator 50 cannot participate in the driving process, the battery pack 110 drives the electric-hydraulic integrated machine 10, and the vehicle enters the pure electric driving mode;

[0128] c. If the accumulator pressure is higher than the minimum working pressure setting value, it is determined whether the driving force provided by the first hydraulic pump / motor assembly 14 can provide the driving force required for vehicle acceleration or starting. If it is sufficient, the high-pressure oil released by the accumulator 50 drives the first hydraulic pump / motor assembly to work, and / or the high-pressure oil released by the accumulator 50 drives the second hydraulic pump / motor 40 to work, and the vehicle enters a pure hydraulic drive mode; if it is insufficient, the battery pack 110 and the accumulator 50 jointly drive the electric-hydraulic integrated machine 10 and / or the second hydraulic pump / motor 40 to work, and the vehicle enters an electric-hydraulic hybrid drive mode.

[0129] Furthermore, the central controller 100 of the four-wheel drive electric vehicle implements the control of different braking energy recovery modes of the driving system according to different signal inputs, and the braking energy recovery modes include:

[0130] a. Pure electric braking energy recovery mode. Fig.21 As shown, the central controller 100 controls the motor assembly of the electro-hydraulic integrated machine 10 to be in a power generation state through the motor controller 200, and the kinetic energy of the vehicle is transmitted to the electro-hydraulic integrated machine 10 through the differential 31 and the reducer 20. The motor assembly of the electro-hydraulic integrated machine 10 generates electrical energy under the action of electromagnetic induction and charges the battery pack 110 through the inverter 500. This mode is used for the braking energy recovery mode when the pressure of the accumulator 50 is greater than the maximum working pressure setting value;

[0131] b. Pure hydraulic braking energy recovery mode, which is used for the working condition where the pressure of the accumulator 50 is less than the maximum working pressure setting value and the braking force provided meets the braking requirements.

[0132] like Fig. 22 As shown, it is an embodiment of a pure hydraulic brake energy recovery mode, the central controller 100 controls the accumulator 50 to be in a liquid-filled state through the valve group assembly 90, the kinetic energy of the vehicle is transmitted to the electric-hydraulic integrated machine 10 through the differential 31 and the reducer 20, the first hydraulic pump / motor assembly 14 of the electric-hydraulic integrated machine 10 is in a pumping state and generates high-pressure oil, and the high-pressure oil is delivered to the accumulator 50;

[0133] Another embodiment of a pure hydraulic braking energy recovery mode, such as Fig.23As shown, the kinetic energy of the vehicle is transmitted to the second hydraulic pump / motor 40 through the reducer 20 or directly, and the second hydraulic pump / motor 40 is in a pumping state and generates high-pressure oil, which is delivered to the accumulator 50;

[0134] Or another embodiment of pure hydraulic braking energy recovery mode, such as Fig.24 As shown, the kinetic energy of the first wheel 61 is transmitted to the first hydraulic pump / motor assembly 14 of the electro-hydraulic integrated machine through the differential 31 and the reducer 20 and generates high-pressure oil, and the kinetic energy of the second wheel 62 is transmitted to the second hydraulic pump / motor 40 through the reducer 20 or directly and generates high-pressure oil, and the high-pressure oil is delivered to the accumulator 50;

[0135] c. Electro-hydraulic hybrid braking energy recovery mode, which is used when the pressure of the accumulator 50 is less than the maximum working pressure setting value, the battery SOC value is less than the maximum working setting value, and a larger braking force is required.

[0136] One embodiment of the electric-hydraulic hybrid braking energy recovery mode is as follows: Fig.25 As shown, the motor assembly of the electro-hydraulic integrated machine 10 is in a power generation state, the first hydraulic pump / motor assembly 14 operates in a pumping state, the accumulator 50 is in a liquid-filled state, and the kinetic energy of the first wheel 61 is transmitted to the motor assembly of the electro-hydraulic integrated machine 10 through the differential 31 and the reducer 20 to generate electrical energy independently and store it in the battery pack 110. The kinetic energy of the second wheel 62 is generated by the second hydraulic pump / motor 40 to generate hydraulic energy independently and store it in the accumulator 50.

[0137] Furthermore, if Fig. 27 As shown, it is a flow chart of the conversion of different braking energy recovery modes of an electric vehicle. The method and steps of converting different braking energy recovery modes of the four-wheel drive electric vehicle include:

[0138] a. Determine whether the pressure of the accumulator 50 is higher than the maximum working pressure setting value. If it is higher than the maximum working pressure setting value, the accumulator 50 cannot participate in the braking energy recovery process, and the kinetic energy of the vehicle is transmitted to the electric-hydraulic integrated machine 10 through the differential 31 and the reducer 20. The motor component of the electric-hydraulic integrated machine 10 generates electrical energy under the action of electromagnetic induction and charges the battery pack 110 through the inverter 500, and the vehicle enters the pure electric braking energy recovery mode;

[0139] b. If the pressure of the accumulator is less than the maximum working pressure setting value, it is determined whether the braking force provided by the first hydraulic pump / motor assembly 14 and / or the second hydraulic pump / motor 40 of the electro-hydraulic integrated machine meets the braking force required by the vehicle. If so, the kinetic energy of the vehicle is converted into hydraulic energy through the first hydraulic pump / motor assembly 14 and / or the second hydraulic pump / motor 40 of the electro-hydraulic integrated machine 10 and stored in the accumulator 50, and the vehicle enters the pure hydraulic braking energy recovery mode;

[0140] c. If the braking force provided by the first hydraulic pump / motor assembly and the second hydraulic pump / motor cannot meet the braking force required by the vehicle, determine whether the battery SOC value is greater than the maximum working setting value. If the battery SOC value is greater than the maximum working setting value, the battery pack 110 cannot be charged, and the vehicle enters a pure hydraulic braking energy recovery plus friction braking mode. If the battery SOC value is less than the maximum working setting value, the kinetic energy of the vehicle generates electrical energy and / or hydraulic energy through the electro-hydraulic integrated unit, or the electro-hydraulic integrated unit generates electrical energy alone and the second hydraulic pump / motor generates hydraulic energy alone. The electrical energy and hydraulic energy are stored in the battery pack 110 and the accumulator 50, respectively, and the vehicle enters an electro-hydraulic hybrid braking energy recovery mode.

[0141] It is also important to note that both battery and accumulator energy storage braking are regenerative braking. In addition to regenerative braking, in order to ensure braking safety and braking efficiency, the electro-hydraulic hybrid drive system should have a traditional friction braking system. When emergency braking is required, it must also have an anti-lock braking system ABS, and under this operating condition, the traditional friction braking system has priority.

[0142] The above contents are further detailed descriptions of the present invention in combination with specific preferred technical solutions, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, and all technical solutions and improvements thereof that do not depart from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A four-wheel drive electric vehicle adopting an electro-hydraulic hybrid drive system, the electro-hydraulic hybrid drive system comprising a central controller (100), a reducer (20), an electro-hydraulic integrated machine (10) connected to the reducer (20), a valve group assembly (90) and an accumulator (50), the electro-hydraulic integrated machine (10) comprising a motor housing assembly (11) and a motor assembly and a first hydraulic pump / motor assembly (14) accommodated in the motor housing assembly (11), the motor housing assembly (11) being provided with a valve group assembly (90), the accumulator (50) being connected to the valve group assembly (90), characterized in that: The invention comprises a battery pack (110), a shift system (70), a first drive axle (35), a second drive axle (36), a differential (31) and a second hydraulic pump / motor (40), wherein the electric-hydraulic hybrid drive system (1) is arranged on the first drive axle (35) and drives the first wheel (61) to move, and the second hydraulic pump / motor (40) is arranged on the second drive axle (36) and drives the second wheel (62) to move; The invention also includes a motor controller (200), a shift controller (300), a valve assembly controller (400) and an inverter (500). The central controller (100) and the motor controller (200), the shift controller (300), the valve assembly controller (400) and the inverter (500) can realize information transmission and control. The central controller (100) realizes the control of different driving modes of the driving system according to different signal inputs: a. In a pure electric drive mode, the battery pack (110) drives the motor assembly of the electric-hydraulic integrated machine (10) through the inverter (500), and transmits mechanical energy to the first wheel (61) through the reducer (20) and the differential (31); the central controller (100) controls the valve group assembly (90) to unload the first hydraulic pump / motor assembly (14); the gear shift system (70) is in an engaged state, and the vehicle is in a two-wheel drive state; b. Pure hydraulic drive mode, the first hydraulic pump / motor assembly (14) of the electro-hydraulic integrated machine operates in a motor operating state, the central controller (100) controls the valve group assembly (90) so that the high-pressure oil of the accumulator (50) drives the first hydraulic pump / motor assembly (14) to operate, and / or the high-pressure oil of the accumulator (50) drives the second hydraulic pump / motor (40) to operate, and the vehicle is in a two-wheel drive or four-wheel drive state; c. In an electro-hydraulic hybrid driving mode, the battery pack (110) drives the motor assembly of the electro-hydraulic integrated machine (10) through the inverter (500), and drives the first hydraulic pump / motor assembly (14) of the electro-hydraulic integrated machine to work under a pumping condition, and the output high-pressure oil drives the second hydraulic pump / motor (40) to work, thereby transmitting mechanical energy to the second wheel (62), the shifting system (70) is in a disconnected state, and the vehicle is in a two-wheel drive state; Alternatively, the battery pack (110) drives the electric-hydraulic integrated machine (10) to work via the inverter (500), and the electric-hydraulic integrated machine outputs mechanical energy and hydraulic energy, wherein the mechanical energy is transmitted to the first wheel (61) via the reducer (20) and the differential (31), and the hydraulic energy is transmitted to the second wheel (62) via the second hydraulic pump / motor (40), and the gear shifting system (70) is in an engaged state, and the vehicle is in a four-wheel drive state; Alternatively, the battery pack (110) drives the motor assembly of the electric-hydraulic integrated machine (10) to operate independently, and transmits the power to the first wheel (61) through the reducer (20) and the differential (31), the first hydraulic pump / motor assembly (14) of the electric-hydraulic integrated machine is unloaded, and the accumulator (50) drives the second hydraulic pump / motor (40) independently and transmits the power to the second wheel (62), and the vehicle is in a four-wheel drive state; The central controller (100) controls different braking energy recovery modes of the drive system according to different signal inputs: a. In a pure electric braking energy recovery mode, the central controller (100) controls the motor assembly of the electric-hydraulic integrated machine (10) to be in a power generation state through a motor controller (200), the kinetic energy of the vehicle is transmitted to the electric-hydraulic integrated machine (10) through a differential (31) and a reducer (20), and the motor assembly of the electric-hydraulic integrated machine (10) generates electric energy under the action of electromagnetic induction and charges the battery pack (110) through an inverter (500); b. In a pure hydraulic braking energy recovery mode, the central controller (100) controls the accumulator (50) to be in a liquid-filled state through the valve group assembly (90), the kinetic energy of the vehicle is transmitted to the electro-hydraulic integrated machine (10) through the differential (31) and the reducer (20), the first hydraulic pump / motor assembly (14) of the electro-hydraulic integrated machine (10) is in a pumping state and generates high-pressure oil, and the high-pressure oil is delivered to the accumulator (50); Alternatively, the kinetic energy of the vehicle is transmitted to the second hydraulic pump / motor (40) through the reducer (20), the second hydraulic pump / motor (40) operates in a pumping state and generates high-pressure oil, and the high-pressure oil is delivered to the accumulator (50); Alternatively, the kinetic energy of the first wheel (61) is transmitted to the first hydraulic pump / motor assembly (14) of the electro-hydraulic integrated machine through the differential (31) and the reducer (20) to generate high-pressure oil, and the kinetic energy of the second wheel (62) is transmitted to the second hydraulic pump / motor (40) to generate high-pressure oil, and the high-pressure oil is delivered to the accumulator (50); c. In an electro-hydraulic hybrid braking energy recovery mode, the motor assembly of the electro-hydraulic integrated machine (10) is in a power generation state, the first hydraulic pump / motor assembly (14) operates in a pumping state, the accumulator (50) is in a liquid-filled state, the kinetic energy of the first wheel (61) is transmitted to the motor assembly of the electro-hydraulic integrated machine (10) through the differential (31) and the reducer (20) and generates electrical energy independently, which is stored in the battery pack (110), and the kinetic energy of the second wheel (62) is transmitted to the second hydraulic pump / motor (40) to generate hydraulic energy independently and store it in the accumulator (50).

2. The four-wheel drive electric vehicle according to claim 1, characterized in that: The method of the central controller (100) controlling the conversion of the electric-hydraulic hybrid drive system into different drive modes comprises: a. Determine whether the battery SOC value is less than the minimum working setting value. If it is less than the minimum working setting value, the vehicle cannot be started and the battery needs to be charged. If the SOC value is greater than the minimum working setting value, the vehicle can be started; b. Determine whether the pressure of the accumulator (50) is less than the minimum working pressure setting value. If it is less than the minimum working pressure setting value, the accumulator (50) cannot participate in the driving process, the battery pack (110) drives the electric-hydraulic integrated machine (10), and the vehicle enters a pure electric driving mode; c. If the pressure of the accumulator (50) is higher than the minimum working pressure setting value, it is determined whether the driving force provided by the first hydraulic pump / motor assembly (14) and / or the second hydraulic pump / motor (40) can provide the driving force required for vehicle acceleration or starting. If it is sufficient, the high-pressure oil released by the accumulator (50) drives the first hydraulic pump / motor assembly to work, and / or the high-pressure oil released by the accumulator (50) drives the second hydraulic pump / motor (40) to work, and the vehicle enters a pure hydraulic drive mode; if it is insufficient, the battery pack (110) and the accumulator (50) jointly drive the electric-hydraulic integrated machine (10) and / or the second hydraulic pump / motor (40) to work, and the vehicle enters an electric-hydraulic hybrid drive mode.

3. The four-wheel drive electric vehicle according to claim 1, characterized in that: The method for the central controller (100) to control the conversion of the electric-hydraulic hybrid drive system into different braking energy recovery modes comprises: a. determining whether the pressure of the accumulator (50) is higher than the maximum working pressure setting value; if the pressure is higher than the maximum working pressure setting value, the accumulator (50) cannot participate in the braking energy recovery process, the kinetic energy of the vehicle is transmitted to the electric-hydraulic integrated machine (10) through the differential (31) and the reducer (20), the motor assembly of the electric-hydraulic integrated machine (10) generates electric energy under the action of electromagnetic induction and charges the battery pack (110) through the inverter (500), and the vehicle enters a pure electric braking energy recovery mode; b. If the pressure of the accumulator is less than the maximum working pressure setting value, it is determined whether the braking force provided by the first hydraulic pump / motor assembly (14) and / or the second hydraulic pump / motor (40) of the electro-hydraulic integrated machine meets the braking force required by the vehicle. If so, the kinetic energy of the vehicle is converted into hydraulic energy through the first hydraulic pump / motor assembly (14) and / or the second hydraulic pump / motor (40) of the electro-hydraulic integrated machine (10) and stored in the accumulator (50), and the vehicle enters a pure hydraulic braking energy recovery mode; c. If the braking force provided by the first hydraulic pump / motor assembly (14) and the second hydraulic pump / motor (40) cannot meet the braking force required by the vehicle, it is determined whether the battery SOC value is greater than the maximum working setting value. If the battery SOC value is greater than the maximum working setting value, the battery pack (110) cannot be charged, and the vehicle enters a pure hydraulic braking energy recovery plus friction braking mode. If the battery SOC value is less than the maximum working setting value, the kinetic energy of the vehicle is generated through the electro-hydraulic integrated machine to generate electrical energy and / or hydraulic energy, or the electro-hydraulic integrated machine generates electrical energy alone and the second hydraulic pump / motor generates hydraulic energy alone, and the electrical energy and hydraulic energy are stored in the battery pack (110) and the accumulator (50) respectively, and the vehicle enters an electro-hydraulic hybrid braking energy recovery mode.

4. A four-wheel drive electric vehicle adopts an electro-hydraulic hybrid drive system, the electro-hydraulic hybrid drive system comprising a central controller (100), a reducer (20), an electro-hydraulic integrated machine (10) connected to the reducer (20), a valve group assembly (90) and an accumulator (50), the electro-hydraulic integrated machine (10) comprising a motor housing assembly (11) and a motor assembly and a first hydraulic pump / motor assembly (14) accommodated in the motor housing assembly (11), the motor housing assembly (11) being provided with a valve group assembly (90), the accumulator (50) being connected to the valve group assembly (90), characterized in that: The invention comprises a battery pack (110), a gear shifting system (70), a first drive axle (35), a wheel-side speed reducer (37) and a second hydraulic pump / motor (40), wherein the electric-hydraulic hybrid drive system (1) is arranged on the first drive axle (35) and drives the first wheel (61) to move, and the second hydraulic pump / motor (40) is connected to the drive wheel hub (38) through two wheel-side speed reducers (37) or is directly arranged in the drive wheel hub (38) and drives the second wheel (62) to move; The invention also includes a motor controller (200), a shift controller (300), a valve assembly controller (400) and an inverter (500). The central controller (100) and the motor controller (200), the shift controller (300), the valve assembly controller (400) and the inverter (500) can realize information transmission and control. The central controller (100) realizes the control of different driving modes of the driving system according to different signal inputs: a. In a pure electric drive mode, the battery pack (110) drives the motor assembly of the electric-hydraulic integrated machine (10) through the inverter (500), and transmits mechanical energy to the first wheel (61) through the reducer (20) and the differential (31); the central controller (100) controls the valve group assembly (90) to unload the first hydraulic pump / motor assembly (14); the gear shift system (70) is in an engaged state, and the vehicle is in a two-wheel drive state; b. Pure hydraulic drive mode, the first hydraulic pump / motor assembly (14) of the electro-hydraulic integrated machine operates in a motor operating state, the central controller (100) controls the valve group assembly (90) so that the high-pressure oil of the accumulator (50) drives the first hydraulic pump / motor assembly (14) to operate, and / or the high-pressure oil of the accumulator (50) drives the second hydraulic pump / motor (40) to operate, and the vehicle is in a two-wheel drive or four-wheel drive state; c. In an electro-hydraulic hybrid driving mode, the battery pack (110) drives the motor assembly of the electro-hydraulic integrated machine (10) through the inverter (500), and drives the first hydraulic pump / motor assembly (14) of the electro-hydraulic integrated machine to work under a pumping condition, and the output high-pressure oil drives the second hydraulic pump / motor (40) to work, thereby transmitting mechanical energy to the second wheel (62), the shifting system (70) is in a disconnected state, and the vehicle is in a two-wheel drive state; Alternatively, the battery pack (110) drives the electric-hydraulic integrated machine (10) to work via the inverter (500), and the electric-hydraulic integrated machine outputs mechanical energy and hydraulic energy, wherein the mechanical energy is transmitted to the first wheel (61) via the reducer (20) and the differential (31), and the hydraulic energy is transmitted to the second wheel (62) via the second hydraulic pump / motor (40), and the gear shifting system (70) is in an engaged state, and the vehicle is in a four-wheel drive state; Alternatively, the battery pack (110) drives the motor assembly of the electric-hydraulic integrated machine (10) to operate independently, and transmits the power to the first wheel (61) through the reducer (20) and the differential (31), the first hydraulic pump / motor assembly (14) of the electric-hydraulic integrated machine is unloaded, and the accumulator (50) drives the second hydraulic pump / motor (40) independently and transmits the power to the second wheel (62), and the vehicle is in a four-wheel drive state; The central controller (100) controls different braking energy recovery modes of the drive system according to different signal inputs: a. In a pure electric braking energy recovery mode, the central controller (100) controls the motor assembly of the electric-hydraulic integrated machine (10) to be in a power generation state through a motor controller (200), the kinetic energy of the vehicle is transmitted to the electric-hydraulic integrated machine (10) through a differential (31) and a reducer (20), and the motor assembly of the electric-hydraulic integrated machine (10) generates electric energy under the action of electromagnetic induction and charges the battery pack (110) through an inverter (500); b. In a pure hydraulic braking energy recovery mode, the central controller (100) controls the accumulator (50) to be in a liquid-filled state through the valve group assembly (90), the kinetic energy of the vehicle is transmitted to the electro-hydraulic integrated machine (10) through the differential (31) and the reducer (20), the first hydraulic pump / motor assembly (14) of the electro-hydraulic integrated machine (10) is in a pumping state and generates high-pressure oil, and the high-pressure oil is delivered to the accumulator (50); Alternatively, the kinetic energy of the vehicle is transmitted to the second hydraulic pump / motor (40) through the reducer (20), the second hydraulic pump / motor (40) operates in a pumping state and generates high-pressure oil, and the high-pressure oil is delivered to the accumulator (50); Alternatively, the kinetic energy of the first wheel (61) is transmitted to the first hydraulic pump / motor assembly (14) of the electro-hydraulic integrated machine through the differential (31) and the reducer (20) to generate high-pressure oil, and the kinetic energy of the second wheel (62) is transmitted to the second hydraulic pump / motor (40) to generate high-pressure oil, and the high-pressure oil is delivered to the accumulator (50); c. In an electro-hydraulic hybrid braking energy recovery mode, the motor assembly of the electro-hydraulic integrated machine (10) is in a power generation state, the first hydraulic pump / motor assembly (14) operates in a pumping state, the accumulator (50) is in a liquid-filled state, the kinetic energy of the first wheel (61) is transmitted to the motor assembly of the electro-hydraulic integrated machine (10) through the differential (31) and the reducer (20) and generates electrical energy independently, which is stored in the battery pack (110), and the kinetic energy of the second wheel (62) is transmitted to the second hydraulic pump / motor (40) to generate hydraulic energy independently and store it in the accumulator (50).

5. The four-wheel drive electric vehicle according to claim 4, characterized in that: The method of the central controller (100) controlling the conversion of the electric-hydraulic hybrid drive system into different drive modes comprises: a. Determine whether the battery SOC value is less than the minimum working setting value. If it is less than the minimum working setting value, the vehicle cannot be started and the battery needs to be charged. If the SOC value is greater than the minimum working setting value, the vehicle can be started; b. Determine whether the pressure of the accumulator (50) is less than the minimum working pressure setting value. If it is less than the minimum working pressure setting value, the accumulator (50) cannot participate in the driving process, the battery pack (110) drives the electric-hydraulic integrated machine (10), and the vehicle enters a pure electric driving mode; c. If the pressure of the accumulator (50) is higher than the minimum working pressure setting value, it is determined whether the driving force provided by the first hydraulic pump / motor assembly (14) and / or the second hydraulic pump / motor (40) can provide the driving force required for vehicle acceleration or starting. If it is sufficient, the high-pressure oil released by the accumulator (50) drives the first hydraulic pump / motor assembly to work, and / or the high-pressure oil released by the accumulator (50) drives the second hydraulic pump / motor (40) to work, and the vehicle enters a pure hydraulic drive mode; if it is insufficient, the battery pack (110) and the accumulator (50) jointly drive the electric-hydraulic integrated machine (10) and / or the second hydraulic pump / motor (40) to work, and the vehicle enters an electric-hydraulic hybrid drive mode.

6. The four-wheel drive electric vehicle according to claim 4, characterized in that: The method for the central controller (100) to control the conversion of the electric-hydraulic hybrid drive system into different braking energy recovery modes comprises: a. determining whether the pressure of the accumulator (50) is higher than the maximum working pressure setting value; if the pressure is higher than the maximum working pressure setting value, the accumulator (50) cannot participate in the braking energy recovery process, the kinetic energy of the vehicle is transmitted to the electric-hydraulic integrated machine (10) through the differential (31) and the reducer (20), the motor assembly of the electric-hydraulic integrated machine (10) generates electric energy under the action of electromagnetic induction and charges the battery pack (110) through the inverter (500), and the vehicle enters a pure electric braking energy recovery mode; b. If the pressure of the accumulator is less than the maximum working pressure setting value, it is determined whether the braking force provided by the first hydraulic pump / motor assembly (14) and / or the second hydraulic pump / motor (40) of the electro-hydraulic integrated machine meets the braking force required by the vehicle. If so, the kinetic energy of the vehicle is converted into hydraulic energy through the first hydraulic pump / motor assembly (14) and / or the second hydraulic pump / motor (40) of the electro-hydraulic integrated machine (10) and stored in the accumulator (50), and the vehicle enters a pure hydraulic braking energy recovery mode; c. If the braking force provided by the first hydraulic pump / motor assembly (14) and the second hydraulic pump / motor (40) cannot meet the braking force required by the vehicle, it is determined whether the battery SOC value is greater than the maximum working setting value. If the battery SOC value is greater than the maximum working setting value, the battery pack (110) cannot be charged, and the vehicle enters a pure hydraulic braking energy recovery plus friction braking mode. If the battery SOC value is less than the maximum working setting value, the kinetic energy of the vehicle generates electrical energy and / or hydraulic energy through the electro-hydraulic integrated machine, or The electric-hydraulic integrated machine generates electric energy independently and the second hydraulic pump / motor generates hydraulic energy independently. The electric energy and the hydraulic energy are stored in the battery pack (110) and the accumulator (50) respectively, and the vehicle enters an electric-hydraulic hybrid braking energy recovery mode.

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