Abstract:
The presently described apparatus and method describes the construction, use and operation of a hydraulic hybrid vehicle including the components and the manner by which the components are integrated into a standard electric powered vehicle. The vehicle may be powered by an electric motor, by a hydraulic motor, or by both acting together.

Description:
PRIOR APPLICATIONS AND PRIORITY CLAIM 
       [0001]    Non-provisional patent application U.S. Ser. No. 14/068,438 of applicant Curtis Newman was filed on 31 Oct. 2013. 
         [0002]    PCT application PCT/US14/59193 of applicant Curtis Newman was filed on 3 Oct. 2014 and claimed priority from U.S. Ser. No. 14/068,438; 31 Oct. 3013. 
         [0003]    This present application of Curtis Newman is filed on 2 May 2016 and claims priority from PCT/US14/59193; 31 Oct. 2013. 
         [0004]    The subject matter of applications U.S. Ser. No. 14/068,438 and PCT/US14/59193 are incorporated herein in their entirety. 
     
    
     BACKGROUND 
       [0005]    The industrial field of this disclosure relates to vehicles which are propelled by other than an internal combustion or external combustion energy source. This disclosure is particularly directed to an electrically driven vehicle, an electrical-hydraulic driven vehicle, and a hydraulically driven vehicle, and to the conversion of electrical vehicles to add hydraulic drive or staging power. 
         [0006]    A two-stage vehicle is a vehicle that has been built by two separate manufacturers. The result is a complete roadworthy vehicle. In this process, vehicles may be converted by a manufacturer, as was done by Ford Motor Company to create the Ford Ranger EV. Alternatively, in a process known as “third-party power-train-modification,” an independent converter purchases a new and then performs a conversion, to produce a two-stage vehicle. In some countries, the user can choose to buy a converted vehicle of any model in the automaker dealerships only paying the cost of the batteries and motor, with no installation costs. This is typically called pre-conversion or previous conversion. 
         [0007]    Electric cars are a variety of electric vehicle (EV); the term “electric vehicle” refers to any vehicle that uses electric motors for propulsion, while “electric car” generally refers to road-going automobiles powered by electricity. While an electric car&#39;s power source is not explicitly an on-board battery, electric cars with motors powered by other energy sources are generally referred to by a different name: an electric car powered by sunlight is a solar car, and an electric car powered by a gasoline generator is a form of hybrid car. Thus, an electric car that derives its power from an on-board battery pack is a form of battery electric vehicle (BEV). Most often, the term “electric car” is used to refer to battery electric vehicles. 
         [0008]    In the 1990&#39;s, a team of engineers working at EPA&#39;s National Vehicle and Fuel Emissions 
         [0009]    Laboratory succeeded in developing a revolutionary type of petro-hydraulic hybrid powertrain that would propel a typical American sedan car. The test car achieved over 80 mpg on combined EPA city/highway driving cycles. Acceleration was 0-60 mph in 8 seconds, using a 1.9 liter diesel engine. The EPA estimated that produced in high volumes the hydraulic components would add only $700 to the base cost of the vehicle. While the petro-hydraulic system has faster and more efficient charge/discharge cycling and is cheaper than petro-electric hybrids, the accumulator size dictates total energy storage capacity and may require more space than a battery set. Research is underway in large corporations and small companies. Focus has now switched to smaller vehicles. The system components were expensive which precluded installation in smaller trucks and cars. A drawback was that the power driving motors were not efficient enough at part load. A British company has made a breakthrough by introducing an electronically controlled hydraulic motor/pump, that is highly efficient at all speed ranges and loads making small applications of petro-hydraulic hybrids feasible. The company converted a BMW car as a test bed to prove viability. The BMW 530i, gave double the mpg in city driving compared to the standard car. Petro-hydraulic hybrids using well-sized accumulators entail downsizing an engine to average power usage, not peak power usage. Peak power is provided by the energy stored in the accumulator. A smaller more efficient constant speed engine reduces weight and liberates space for a larger accumulator. Current vehicle bodies are designed around the mechanicals of existing engine/transmission setups. It is restrictive and far from ideal to install petro-hydraulic mechanicals into existing bodies not designed for hydraulic setups. One research project&#39;s goal is to create a blank paper design new car, to maximize the packaging of petro-hydraulic hybrid components in the vehicle. All bulky hydraulic components are integrated into the chassis of the car. One design has claimed to return 130 mpg in tests by using a large hydraulic accumulator which is also the structural chassis of the car. The small hydraulic driving motors are incorporated within the wheel hubs driving the wheels and reversing to claw-back kinetic braking energy. The hub motors eliminate the need for friction brakes, mechanical transmissions, drive shafts and U joints, reducing costs and weight. Hydrostatic drive with no friction brakes are used in industrial vehicles. The aim is 170 mpg in average driving conditions. Energy created by shock absorbers and kinetic braking energy that normally would be wasted assists in charging the accumulator. A small fossil fuelled piston engine sized for average power use charges the accumulator. The accumulator is sized for running the car for 15 minutes when fully charged. The aim is a fully charged accumulator with an energy storage potential of 670 HP, which will produce a 0-60 mph acceleration speed of under 5 seconds using four wheel drive. In January 2011 industry giant Chrysler announced a partnership with the U.S. Environmental Protection Agency (EPA) to design and develop an experimental petro-hydraulic hybrid powertrain suitable for use in large passenger cars. In 2012 an existing production minvan will be adapted to the new hydraulic powertrain. The present disclosure provides an apparatus that overcomes the problems found in the prior art and extends the technology into a more realistic and practical regime. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0010]      FIG. 1  is an example block diagram of an embodiment of the presently described apparatus; 
           [0011]      FIG. 2  is a logic diagram describing operation thereof. 
       
    
    
       [0012]    Like reference symbols in the drawing figures indicate like elements. 
       DETAILED DESCRIPTION 
       [0013]    The presently described apparatus and its method of use refer to an electric automobile truck, or bus, referred to herein by the term “vehicle.” However, practically, the vehicle may not only be wheel-driven vehicles, but also a may be a water borne vehicle such as a power boat or other types of vehicles. In the present description we refer to a specific embodiment which is a particular automobile that represents a typical consumer operated automobile and its best use is in the mass vehicle marketplace which vehicles are used for transportation, commuting, shopping and other daily activities that require personal transportation. 
         [0014]    The vehicle described herein comprises a standard commercially available and typical production electric automobile referred to herein as the “purchased unit,” as for instance a model BY-03 manufactured by Shandong Baoya New Energy Vehicle Co. Ltd. of China. Included in the purchased unit are (see  FIGS. 1, 2, and 3 ): battery  10 , electric motor/gen  20 , drive wheels  30 , transmission  40 , differential  100 , and all other components, assemblies, subassemblies, typically found in a fully operational consumer vehicle, i.e., seats, steering wheel, gauges, lights, operator&#39;s panel, etc. The purchased unit is then modified by installation and integration of “selected components” as described in detail below and such modification of and integration into the purchased unit is within the skill of typical automotive mechanics without undue experimentation. However, the selected components and their integration scheme, as described herein, is considered to be novel and would not be obvious to those of skill in the automotive trades, skills, and know-how. The composite prior art cannot be considered to teach the present apparatus or to render it obvious to those of skill in the art. 
         [0015]    The major selected components may include:
       Hydraulic pump  50 , an Eaton Manufacturing Co., model S26, rated as 6.6 gpm, at 3000 psi.   Accumulator  60 , a nitrogen bladder type supplied by Eaton as part number A2 30 and rated at 3000 psi.   Hydraulic motor  70 , an H series by Eaton rated at 3000 psi and 1,000 rpm.   Alternator  80  manufactured by Fast Max Alternators and rated at 98 vdc and 12 KW output.   Hydraulic cylinder pumps  90 , by Milwaukee Cylinder, LH series.   Holding tank  110 , by Eaton specified as Low Pressure Holding and Cooling Tank.   Controller  15  manufactured by Siemens Electric Vehicle Division providing inversion pulse frequency alternating current output and provides logic signals for control.       
 
         [0023]    Various other components well known in the art in accordance with the above major components, are included, such as sprockets, pulleys, clutch, and related interconnecting belts by Fast Max, standard electrical cables and conduits, high pressure fluid conduits, a 4:1 step-up gear set by Fast Max and miscellaneous hardware items used for installation into the vehicle as would be known to those of skill in the mechanical, hydraulic, and electrical trades without undue experimentation. 
         [0024]    Now referring to a first embodiment of the apparatus, shown in  FIG. 1 , the vehicle may use, for instance, a direct current (vdc) lithium-ion electrical battery  10 , or other type of battery, which delivers a pulsed current to 30 horsepower (hp) electrical motor/gen  20  through controller  15 . With ignition on and transmission  40  in drive, accelerator pedal  5  sends a control voltage to controller  15  which adjusts its output pulse frequency to provide a driver selected drive voltage to electric motor/gen  20  so as to accelerate or maintain vehicle velocity as desired through transmission  40 , differential  100 , and drive wheels  30 . When the driver releases accelerator pedal  5 , controller  15  sets drive voltage to zero. If electric motor  20  continues to rotate, driven by drive wheels  30  through differential  100  and transmission  40  due to vehicle momentum or if on a downgrade by vehicle momentum and gravitational force, electric motor/gen  20  operates as an electric generator and controller  15  sends a signal which closes clutch  18  thereby enabling electric motor/gen  20  to rotate hydraulic pump  50  via a mechanical linkage of any type known to those of skill in the art. Pump  50  delivers hydraulic pressure to accumulator  60  which operates hydraulic motor  70  and alternator  80  to send a charging current to battery  10 . 
         [0025]    When drive voltage is zero and clutch  18  is engaged, a braking force from hydraulic pump  50  is applied to drive wheels  30  through electric motor/gen  20  transmission  40  and differential  100 . Brake pedal  8  may be applied by the vehicle operator as well to slow the vehicle more quickly or bring it to a stop. 
         [0026]    Hydraulic cylinder pumps  90  are mounted between the vehicle&#39;s carriage and its suspension system so that while the vehicle is being driven, as the vehicle&#39;s wheels move vertically due to terrain roughness, pumps  90  produce hydraulic pressure in accumulator  60 . Hydraulic fluid is returned to hydraulic pump  50  from the hydraulic motor  70  and cylinder pumps  90  via holding tank  110 . In this hydraulic system overpressure relief valves and check valves are employed to eliminate back pressure and cavitation in system components and lines. 
         [0027]    In an alternate embodiment, as shown in  FIG. 2 , hydraulic motor  70  is engaged with transmission  40  and may be used to provide driving force to drive wheels  30  alone or in addition to electric motor/gen  20 . This additional power may be useful when greater acceleration or hauling power is required. The operation of this dual drive is controlled by signals from controller  15  as enabled by actuators accessible to the driver from his control panel. In an alternate method of operating the apparatus, transmission  40  can be disengaged from electric motor/gen  20  allowing hydraulic motor  70  to be the primary vehicle drive and allowing the electric motor/gen  20  to only operate pump  50 . 
         [0028]    The controller  15  delivers a proportional voltage to electric motor/gen  20  so as to accelerate or maintain vehicle velocity. Electric motor/gen  20  may be operated according to a standard digital pulse voltage signal with pulse rate controlling the average voltage delivered to electric motor/gen  20 . The accelerator pedal may operate through a potentiometer circuit whose signal is delivered to controller  15 . Storage battery  10  may be made up of a plurality of low voltage batteries cells arrange in electrical series connection to achieve a higher drive voltage such as 144 vdc. The operation of electric motor operation and control through pulse voltage inputs is well known in the field of the present apparatus. Electric motor/gen  20  is an alternating current device operable by a pulse voltage whose frequency determines the average applied voltage received. The controller  15  inverts dc battery voltage to a pulsed ac voltage, and adjusts the ac voltage pulse frequency based on the drive current demanded by the driver&#39;s accelerator pedal  5 . It also provides coasting and regenerative braking using electric motor/gen  20  as an electric generator for converting the vehicle&#39;s kinetic energy to power which is delivered to battery  10 , as previously described. Controller  15  protects electric motor/gen  20  from overheating using thermo-couple sensors attached to electric motor/gen  20  and protecting against current overloads by placement of ammeter sensors in the several circuits which protects battery  20  from under voltage during acceleration and from over voltage during regeneration. The controller  15  also provides  12  vdc to operate vehicle accessories, displays operating parameter displays, etc. 
         [0029]    The controller has a microprocessor computer and solid state memory holding a logic program which controls operation of the vehicle. Programming enables making timing adjustments relevant to internal signals, interfacing with closed loop hydraulic systems sensors that monitor hydraulic fluid flow rates, temperature and pressure, clutch state, and other necessary features. 
         [0030]    Made by Siemens Corporation, controller  15  is 94% energy efficient and is specifically developed for use in electric vehicles. It is rated at 280 amps at 380 vdc which enables it to handle up to 100 kW of power. 
         [0031]    The presently described apparatus converts two kinetic energy inputs to electrical energy stored in battery  20 . First, kinetic energy is derived from rotation of the output shaft of electric motor/gen  20  as driven by transmission  40  when the input voltage to electric motor/gen  20  from controller  15  is zero (accelerator pedal  8  not depressed). Electric motor/gen  20  delivers power to battery  10  through the hydraulic system at this time as previously described. Second, kinetic energy is harvested from cylinder pumps  90  which function once the vehicle is in motion over a road. Vehicle operation creates a reciprocating vertical motion of these pumps  90  whose average frequency at a vehicle speed of 25 mph of between one and three cycles per second (cps) with a total linear travel of between two and six centimeters per cycle. Cylinder pumps  90  operate at a pressure of 2,000 psi and a flow rate of about 5 gallons per minute (gpm) under a load of about 570 pounds on each cylinder. Two or more cylinder pumps  90  may be used in the present application. Hydraulic pressure is delivered to accumulator  60  which drives hydraulic motor  70 , and alternator  80  to deliver electrical current to battery  10  as previously described. A drive arrangement comprising pulleys and belts or gears enable engagement and disengagement of clutch  18  between electric motor/gen  20  and hydraulic pump  50 . In the first embodiment, hydraulic pump  50  is powered only when electric motor/gen  20  has a zero voltage input from controller  15 . In test vehicles on a level road, electric motor/gen  20  used 7.5 KW continuously to produce a steady vehicle velocity of 40 mph. At the same time cylinder pumps  90  produced about 1.7 KW continuous which is recovered by battery  10 , as 1.7 KW-h per hour. The net result is that the cylinder pumps  90  carry about 23% of the energy required for vehicle operation. This results in a 23% extension of vehicle range. 
         [0032]    Embodiments of the subject apparatus and method have been described herein. Nevertheless, it will be understood that modifications may be made without departing from the spirit and understanding of this disclosure. Accordingly, other embodiments and approaches are within the scope of the following claims.