Power module combined with an electro-hydraulic propulsion system

Abstract

The vehicle drive system comprises a battery, a power unit in a housing, the power unit comprising at least one electric motor / generator capable of being driven by the battery as a motor or as a generator to charge the battery, at least one hydraulic motor / pump capable of being driven by the electric motor / generator to pressurize hydraulic oil or capable of being driven by pressurized hydraulic oil as a generator to power the motor / generator, a hydraulic rail in communication with the pump, and a directional control valve in communication with the hydraulic rail, at least one accumulator for storing pressurized hydraulic oil, wheel drives capable of being driven by pressurized hydraulic oil, a hydraulic circuit connecting the directional control valve in the motor housing to the accumulator and the wheel drives, and a control system for controlling operation of the battery, the power unit, and the wheel drives.

Description

Technical Field

[0001] The present invention relates to a combined and unique power module that houses a separable electric motor and a hydraulic valve system designed to be used in a wide variety of complex wheeled vehicles. The present invention provides a solution that is simpler, more compact, lighter, and thus more cost-effective, compared to the hybrid electric internal combustion engines and hydraulic-electric power units that exist today.

Background Art

[0002] As we rush headlong into the green era, what we are seeking is a practical solution to our dependence on the earth's mineral and oil resources for energy. This solution addresses both of these elements by reducing the expensive materials (such as metals and rare earth magnets) currently used in power and transmission modules for all types of ITC and electric vehicle configurations.

[0003] In recent years, progress in electrical equipment and energy storage technologies and the combined goals of multiple societies to combat climate change have promoted and accelerated the development of electromobility. The introduction of low-emission or zero-emission zones in cities and changes in the political framework will accelerate that development. Some enterprises are investing in electromobility, expanding existing concepts, introducing technological innovations, and planning their future uses. The present invention is part of this necessary development of current solutions for electromobility to improve the sustainability of the materials used in the manufacture of vehicle power and transmission elements by reducing the amounts used to achieve the same purpose.

[0004] The advantages of electromobility are well known to those skilled in the art and can be demonstrated by improved maintenance and reduced noise pollution, as well as by its indirect impact on reducing CO2 emissions and other harmful gases. In addition, in the near future, highly congested and polluted urban centers will become zero-emission zones, and only zero-emission vehicles will be allowed to drive within them. Summary of the Invention [Problem to be solved by the invention]

[0005] It is an object of the present invention to provide an electric vehicle drive that is easy to manufacture and / or reliable and / or efficient. Other advantages will become apparent from the description.

[0006] Current electromobility solutions have a maximum efficiency of 96% compared to internal combustion engines, which have a maximum efficiency of 40%.

[0007] Efficiency is further improved by the traction motor being able to operate as a generator to recover braking energy for reuse when required.

[0008] The emergence of new electric vehicles with a range of technologies has provided this solution, which eliminates nearly all of the costly and complex existing mechanical drive components present in existing vehicle designs seen today.

[0009] In embodiments of the present invention, this is ideally achieved by storing braking energy in an accumulator and then using it to power a motor, act as a generator to recharge the battery, or to run the system with increased power for short periods of time, i.e., to overtake.

[0010] To maintain heat within the system, the unit is insulated. This heat is then converted to electricity via a heat recovery system, and this electricity is also used for battery recharging, thus further improving the overall efficiency. The energy loss due to heat generated within the system is minimized.

[0011] The heat recovery system, when used, can be utilized as a cooling system, thus improving the overall efficiency. The cooling and hydraulic systems are combined systems that initially use a water / glycol-based fluid, thus achieving a "green" ethos.

[0012] The solution proposed in this specification can be strategically placed on the chassis of any vehicle that adopts this system for any of the advantages that this specification can provide. This is made possible by eliminating all common mechanical power transmission elements.

[0013] The disengaged motor / generator can be designed to operate much more quickly than current solutions, reducing the amount of rare earth magnet material required. This further reduces the total cost element and allows for greater placement freedom of the major components of various vehicles.

[0014] This fully integrated hydraulic-electric propulsion unit is smaller, lighter, more efficient, simpler, and more cost-effective than existing vehicle drive solutions. It disengages the drive unit.

[0015] It can have multiple motor / generators, thus enabling complete optimization for power supply or filling of the energy storage system independently or simultaneously.

[0016] This high-speed and compact permanent magnet motor / generator can reduce size and weight, further improving the efficiency of the vehicle.

[0017] The present invention optimizes the use of an electric / hydraulic transmission approach by opening up the possibility of increasing the energy storage capacity through the use of two types of energy storage units, namely a compressed oil storage system and a battery storage system. This hydraulic system is used to reduce the charge / discharge rate of the battery during startup and braking, thereby extending its lifespan.

[0018] The design of this system attempts to eliminate all the basic mechanical transmission elements present in current electric hybrid and ICE solutions.

[0019] Each accumulator can also be independently filled from the outside by compressed air that is temporarily attached to an inlet provided as needed.

Means for Solving the Problems

[0020] According to the present invention, an electromobility power unit as described in claim 1 is provided.

[0021] According to the present invention, an electromobility power module solution is provided that uses an electric / hydraulic architecture to disconnect the drive unit from the transmission system.

[0022] According to the present invention, greater freedom in the positioning of the main components for various vehicles is made possible for the realization of an optimal weight distribution and for the low center of gravity of high-performance vehicles.

[0023] According to the present invention, the position of the power module can lower the position of the center of gravity and improve vehicle handling and load-holding characteristics.

[0024] According to the present invention, since the power module eliminates the drive shaft and associated transmission components, the total number of parts is reduced and the overall mechanical design is simplified.

[0025] The power module is preferably operable at a substantially constant high speed in order to reduce its size and weight, and further improve the efficiency of the vehicle.

[0026] The compressed medium oil storage system is preferably combined with a battery storage unit to provide a redundant energy storage solution. The compressed medium oil storage system reduces the charge and discharge rate of the battery and thus extends its life.

[0027] The present invention enables a complex wheel drive vehicle architecture without a complex mechanical drive system.

[0028] This fully integrated hydraulic-electric propulsion unit is a smaller, lighter, more efficient, simpler, and more cost-effective solution compared to existing vehicle drive solutions. It decouples the drive unit to allow for greater freedom in the placement of major components for various vehicles.

[0029] Since it can have multiple motors / generators, it can enable complete optimization for power supply or filling of the storage system independently or simultaneously.

Brief Description of the Drawings

[0030] [Figure 1a] It is a schematic diagram of a general electro-hydraulic power module assembly. [Figure 1b] It is a schematic diagram of an electro-hydraulic power module assembly showing further details. [Figure 2] It is a schematic diagram of the internal assembly of the motor generator. [Figure 3] It is a partial detailed view of a schematic diagram showing an integrated hydraulic valve system for individual wheel drive units. [Figure 4] It is a partial detailed view of a schematic diagram showing an individual wheel drive and brake control system. [Figure 5] It is a partial detailed view of a schematic diagram showing a valve for controlling a hydraulic clutch attached to the motor / generator. [Figure 6] A partial detailed view of a schematic diagram showing a hydraulic pressure supply valve for controlling the hydraulic pressure from an accumulator or an electric motor to each wheel. In another embodiment, a single hydraulic pressure supply to a multi-way distribution valve that can be used to distribute power to individual wheels to achieve steering and torque vectoring control. [Figure 7] A detailed schematic diagram showing a valve control system for distributing the hydraulic pressure generated under braking from a wheel pump to an accumulator. [Figure 8] A three-dimensional view of a power module. [Figure 9] A side view of a power module showing the positions of cross-sections A-A, B-B, C-C, F-F, and G-G, and further showing the hydraulic valve inlet / outlet port configuration. [Figure 10] Shows the detailed cross-section A-A of the power module. Also shows the position of cross-section D-D. [Figure 11] Shows the detailed cross-section B-B of the power module. Also shows the position of cross-section E-E. [Figure 12] Shows the detailed cross-section C-C of the power module. [Figure 13] Shows the detailed cross-section F-F of the power module. [Figure 14] Shows the detailed cross-section G-G of the power module. [Figure 15] Shows a detailed end view of the power module showing the inlet / outlet ports for the cooling and hydraulic systems. [Figure 16] Shows the bottom view of the power module. Also shows the position of cross-section H-H. [Figure 17] Shows the detailed cross-section D-D of the power module showing the port for the high-pressure supply from the pump / motor. [Figure 18] Shows the detailed cross-section E-E of the power module showing the hydraulic supply and return from the wheel pump / motor. [Figure 19] Shows the detailed cross-section H-H of the power module showing the electro-hydraulic drive system configuration. [Figure 20]It is a three-dimensional cross-sectional view showing the dispersion of main components. [Figure 21] For clarity, a detailed three-dimensional cross-section H-H showing the electric / hydraulic drive configuration is shown.

Best Mode for Carrying Out the Invention

[0031] In the following description, a great deal of detail is set forth in order to provide an understanding of the present invention. However, one of ordinary skill in the art will understand that the present invention may be practiced without these details and that numerous variations or modifications from the described embodiments are possible.

[0032] The present invention relates to an integrated electric / hydraulic power module and its actual implementation in a standard vehicle or a sports vehicle. However, the apparatus and method of the present invention are not limited to use in the specific applications described in this specification.

[0033] Referring generally to FIG. 1, a schematic diagram of a fully integrated electric / hydraulic power module that uses hydraulic pressure as a power distribution and control means is shown.

[0034] The motor / hydraulic integrated system includes an electric motor / generator driven by a battery (or charging the battery via a bi-directional converter) in response to control by a charge controller and a control system. The electric motor is connected to a turbomachine that controls each wheel of the vehicle via hydraulic lines to / from each wheel of the vehicle. Each wheel is driven by a variable hydraulic pump / motor system incorporating a hydraulic fail-safe ABS system.

[0035] As shown in Figure 1, this integrated unit is water-cooled and insulated to prevent heat loss. A heat recovery system may also be included. This heat recovery system can be, for example, an organic Rankine cycle heat-electric converter (which may use a Peltier element to convert heat to electricity) that can be used to drive a motor or store power in a battery. The cooled pressurized medium oil from the converter can then be refluxed, via a sealed hydraulic reservoir, by the hybrid unit cooling system, into the water jacket surrounding the motor / hydraulic integrated system.

[0036] Figure 2 is a schematic diagram showing the main circuits within the system and their interconnections. That is, the integrated control valves and distribution to the input / output ports for the power module, wheel drive and braking sections, and the integrated motor / generator assembly are shown.

[0037] Referring to Figure 2, the entire power and drive system is shown. Each of its subsystems will be described separately. Further referring to Figure 3, the motor / generator assembly 2 is shown. These assemblies are units integrated within the power unit and are each independently controlled. Motors / generators 1 and 2 drive, or are driven by, the integrated hydraulic motors / pumps 3, 4. This is made possible via clutches 7 and 8. Thereby, the system can utilize the energy stored in the battery or hydraulic accumulator to supply power to the system. Thereby, the battery can also be charged by the braking energy stored in the hydraulic braking accumulator.

[0038] To pressurize the accumulator, the integrated compressors 5 and 6 can also be driven via clutches 9 and 10 using hydraulic or electrical energy. Thus, the control system will regulate and activate units 1 - 10.

[0039] In motoring mode, motor / generator 1 or 2 drives pump assemblies 3 and 4.

[0040] Pump assemblies 3 and 4 can either drive the wheels directly or pressurize an accumulator system via valve assemblies 23, 24, and 25 (Figure 6), which in turn can power the motor / pump units that drive each wheel.

[0041] Referring to FIG. 3, a schematic diagram of a system for driving a motor / generator, via the motor configuration of pump / motor assemblies 3 and 4, via clutches 7 and 8 (see FIG. 2) and valves 11-14, as a generator using power from a braking accumulator to charge a battery. Alternatively, the pump configuration of pump / motor assemblies 3 and 4 (FIG. 2) is used to provide hydraulic power for other applications. The two motor / generator systems are independent of each other, and the available applications and configurations at any given time are set by the control system. One motor / generator operates to pressurize hydraulic oil while the other motor / generator operates to charge a battery. Alternatively, both motor / generators can simultaneously pressurize hydraulic oil or function as generators to simultaneously charge a battery.

[0042] When driven as a motor, the motor / generator M / G1 drives an integrated hydraulic motor / pump 3 to pressurize hydraulic fluid which is supplied from the pump via a diverter valve to either the wheel drives or the accumulator. Alternatively, or in addition, pressurized hydraulic fluid can be supplied from the accumulator to the wheel drives via a directional valve 13, a pressure relief valve 11 and a check valve 12. A reservoir communicates with the hydraulic motor / pump 3 via a directional valve 14. The directional valve 14 allows fluid to flow in either direction and via the check valve 12 to the wheel drives or the accumulator.

[0043] The motor / generator M / G2 is connected to the wheel drive unit, the accumulator, and the reservoir by a second valve set and a hydraulic motor / pump 4 set up in the same way as the motor / generator M / G1.

[0044] Referring to FIG. 4, on the one hand, there is shown a schematic diagram for controlling the hydraulic drive to and from the wheel motor / pump and the braking system, and on the other hand, to and from the accumulator, the braking accumulator, and / or the hydraulic motors / pumps 3, 4 using valves 15, 16, and 17. The configuration for these valves is set by the vehicle control system.

[0045] Referring to FIG. 5, there is shown a schematic diagram for controlling the operation of clutches 7, 8, 9, and 10 (shown in FIG. 2) via valves 18, 19, 20, 21, and 22 according to the system requirements set by the vehicle control system. The operation of the clutches is ideally performed by pressurized fluid from the accumulator.

[0046] Referring to FIG. 6, there is shown a schematic diagram for controlling the hydraulic pressure distribution from pumps 3 and 4 driven by hydraulic pumps M / G1 and M / G2 (see FIG. 2) via valves 23, 24, and 25 to supply power directly to each wheel or via the accumulator system according to the system requirements set by the vehicle control system.

[0047] Referring to FIG. 7, there is shown a schematic diagram showing each valve for controlling the return flow from the wheel pump / motor. Valve 26 directs the flow from the braking pump to the accumulator via valves 27 and 28 or the return flow from the drive unit to the reservoir via the heat recovery system according to the system requirements set by the vehicle control system.

[0048] During braking, power is extracted from each wheel through the wheel-mounted motor / pump unit. The flow and pressure generated by the wheel-mounted motor / pump unit during braking are stored in the brake accumulator. The stored energy can be retained in the accumulator or used to drive the main motor / pump assembly (see Figure 2). The generated electric power is processed by a bi-directional converter to charge the battery. The logic for selecting between storage and battery charging is set to optimize the driving state and vehicle range. The logic for optimal control of energy storage is embedded in the vehicle control system.

[0049] The bi-directional controller converts the power drawn from the battery into the necessary input for the motor / generator. This conversion depends on the battery and the motor, and can, for example, control the conversion of a DC battery output to a poly-phase input for a switched DC motor. Similarly, the bi-directional controller controls the charging current energy from the motor / generator (or the accumulator compressor) to be stored in the battery.

[0050] Referring to Figures 8 and 9, the entire power module is shown. These figures show some of the main ports for basic connections and the cross-sections shown in each of the following figures. The power module houses the motor / generators M / G1 and M / G2, the hydraulic motors / pumps 3, 4, and the connections to the hydraulic system. These connections include a hydraulic supply inlet port, a hydraulic valve assembly, a hydraulic inlet / outlet port, a cooling system inlet, and a hydraulic and return port. These will be further explained below.

[0051] Referring to Figure 10, a front view of the cross-section A-A of the power module, the positions of some of the main components related to this cross-section, and the position of the cross-section D-D are shown.

[0052] The power module outer casing houses the motor / generators M / G1 and M / G2, the hydraulic motor / pump, and the directional valve. The two electric motor / generator rotors are conveniently arranged coaxially in series and are operable independently. The power module outer casing housing has a convenient shape for accommodating the diameter of the motor / generator rotor by means of a saddle-shaped portion, but each valve assembly does not require this housing thickness. The electric motor / generator has conveniently an outer stator and an inner rotor mounted on a center bearing support, and is housed in a cylindrical electric motor / generator outer casing. A motor / generator cooling jacket surrounds the electric motor / generator outer casing, and a cooling fluid is supplied and circulated through the cooling jacket transfer port. The valve system is located in the side portion of the power module outer casing. The valve system also has a valve system cooling jacket. Four hydraulic common rails for each motor / generator for supplying pressure and a return port extend along the long axis of the power module, and since there is a partition 29 (shown in FIG. 17) between these rails and each motor / generator, the outlet of the hole of each rail is at both ends of the casing as shown in other figures. Instead of the partition 29, these rails can also be combined through a valve.

[0053] Referring to FIG. 11, a front projection view of the cross-section B-B of the power module is shown. This figure shows the position of the cooling jacket transfer port and the position of the cross-section E-E.

[0054] Referring to FIG. 12, a front projection view of the cross-section C-C of the power module is shown. This figure shows the position of the transfer port for the hydraulic valve system related to this cross-section (in this figure, controlling the communication with the two lower hydraulic rails).

[0055] Referring to FIG. 13, a front projection view of the cross-section F-F of the power module is shown. This figure shows the position of the transfer ports for the hydraulic valve system related to this cross-section (in this figure, controlling the communication with the upper two hydraulic rails).

[0056] Referring to FIG. 14, a front projection view of the cross-section G-G of the power module is shown. This figure shows the position of the inlet / outlet ports for one of the pumps / motors. This pump / motor pressurizes the fluid in the lower two hydraulic rails. Alternatively, these hydraulic rails can operate the motor / generator to generate power for recharging the battery.

[0057] Referring to FIG. 15, a front projection end view of the power module is shown. This figure shows the positions of the inlet / outlet ports of the hydraulic common rail and the inlet port of the cooling system.

[0058] Referring to FIG. 16, a front projection bottom view and a cross-section H-H of the power module are shown.

[0059] Referring to FIG. 17, a cross-section D-D of the power module is shown. This figure shows the pressure supply and return flow options from the valve system to the pump / motor.

[0060] The motor / generator assemblies 1, 2 drive, or are driven by, the integrated compressors 5 and 6 and the hydraulic motors / pumps 3, 4 to supply or draw in pressurized fluid from a hydraulic rail (here, the lower rail) extending axially along the power unit. A plurality of shut-off valves (generally at both ends) control the direction of the flow in the valve system. Each internal valve controls the hydraulic pressure distribution to and from the wheel drive part away from the side of the power unit. The supply to the cooling jacket is from the cooling system inlet. The outlet is at the opposite end.

[0061] Referring to FIG. 18, a cross-section E-E of the power module is shown. This figure shows an option of an internal valve system for controlling the hydraulic return distribution to and from each wheel drive unit. In this cross-sectional view taken from the upper hydraulic rail, a further internal valve system controls the hydraulic distribution to and from each wheel drive unit. Pump / motor inlet / outlet plenum chambers are provided for the integrated compressors 5 and 6. These pump / motor inlet / outlet plenum chambers engage with the motor / generator assemblies 1, 2 via clutches 7 and 9 and clutches 6 and 10.

[0062] Referring to FIG. 19, an orthographic projection view of a cross-section H-H of the power module is shown. This figure shows the flow-through of the cooling system, the position of the hydraulic pump / motor supply / return flow options, and the position of some of the main components related to this cross-section.

[0063] Referring to FIG. 20, a semi-transparent three-dimensional view of the power module is shown. This figure shows the dispersion of the main components.

[0064] Referring to FIG. 21, a three-dimensional view of a cross-section H-H of the power module is shown. This figure shows the dispersion of the main components and the clutch drive configuration for the pump / motor and compressor units.

[0065] The system described in this specification includes two motors / generators. It would also be possible to drive an electric / hydraulic vehicle with a single motor / generator within the casing according to this design (if the valves and hydraulic rails of the casing are appropriately modified). With two motors / generators, the use of a single motor becomes possible, especially during constant-speed cruising, which improves efficiency. At this time, the second motor / generator could be activated for small deviations if necessary. In particular, the hydraulic pump of the second motor / generator can supply additional power to accelerate the vehicle (especially when the vehicle is cruising and the acceleration requirement is temporary for a short time) when the first motor / generator is supplying a certain amount of power. Conversely, during deceleration of the vehicle, the second motor / generator can be used to recover excess energy from the hydraulic system and regenerative braking (again, especially when the vehicle is cruising and the braking or deceleration time can be temporary for a short time).

[0066] During braking, the increase in hydraulic pressure may be too rapid for the second motor / generator to immediately convert the excess pressure into electricity and use it for battery charging. In this case, the pressurized fluid can be stored in an accumulator until the second motor / generator can use the pressurized fluid for battery charging. This enables smoother charging and discharging, thus increasing the regenerative power captured and extending the battery life.

[0067] Accumulators are particularly sensitive to transient demands for energy supply or storage by pressurized fluids. Therefore, the two motors / power generators and the accumulator can be operated so that the speed changes of one or both motors / power generators are minimized during vehicle operation, resulting in improved operating efficiency and reduced wear of components.

Claims

1. A vehicle drive system comprising: a battery; a power unit within a housing, at least two independent electric motor / generators, each of which is drivable as a motor by the battery or chargeable as a generator to charge the battery, each electric motor / generator being connected to a separate hydraulic motor / pump, and the independent electric motor / generator and the hydraulic motor / pump connected thereto being independently operable; at least two hydraulic motors / pumps, each connected to an individual electric motor / generator, the at least two hydraulic motors / pumps being drivable by the electric motor / generator to pressurize a pressure medium oil or drivable by the pressurized pressure medium oil to supply power to the electric motor / generator as a generator; a hydraulic rail communicating with the pump; a direction control valve communicating with the hydraulic rail; a power unit including the same; at least one accumulator for storing pressurized pressure medium oil; a wheel drive unit drivable by the pressurized pressure medium oil; a hydraulic circuit connecting the direction control valve of the housing to the accumulator and the wheel drive unit; a control system for controlling the operations of the battery, the power unit, and the wheel drive unit; A vehicle drive system including the same.

2. The vehicle drive system according to claim 1, wherein the hydraulic rail communicates with a plurality of valves.

3. The vehicle drive system according to claim 1 or 2, wherein the housing is formed from an integral body, and holes for the at least two electric motor / generators and at least one direction control valve are located within the body.

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