Patent Publication Number: US-2007119639-A1

Title: Secondary power system for automobiles

Description:
TECHNICAL FIELD OF THE INVENTION  
      The present invention relates to power systems for driving motor vehicles and more particularly to a power system which utilizes an electric motor and flywheel combination.  
     BACKGROUND OF THE INVENTION  
      The most widely used form of transportation in the world today is based on the use of internal combustion engines as the prime mover of ground transportation vehicles. Such engines are controlled by a throttle which varies the amount of fuel and air metered to the engine typically through a carburetor. The nature of the internal combustion engine fuel-burning process is such that products of incomplete combustion are generally admitted to the air. In addition to this basic engine problem, engine throttling is an inherently inefficient process, particularly at light load. Quick engine power response requires fuel-air mixture enrichment, thus adding to unburnt product emissions. All of these factors are particularly important in large cities where start-and-stop driving is common and where pollution is of major concern.  
      An interest in hybrid power systems has arisen primarily because of the increasing cost of fuel and the inefficiency of operation of conventional internal combustion engine power systems for motor vehicles. When an internal combustion engine is the sole source of power for a motor vehicle, the engine must be of sufficient size and capacity to deliver maximum power loads on demand for acceleration, even though such demands are occasional and the normal operation is at a much lower power demand range. The engine could operate much more efficiently if it could operate substantially continuously within an optimum efficiency operating range without maintaining the capability of providing an output substantially greater than this range. Utilizing an engine requiring operation only in the optimum efficiency operating range would allow the use of a less powerful and a much lighter engine with the obvious attendant economy.  
      Electric motors have been developed as substitutes for internal combustion engines, but they have been found to be generally unacceptable for universal usage in motor vehicles because of the limited energy storage capacity of electric storage batteries in relation to weight limitations for efficient vehicle application and because of the extended time that batteries must be out of operation for recharging.  
      Flywheels have also been utilized in attempts to store kinetic energy that can be delivered during times of peak load demand so that an internal combustion engine or an electric motor need not have the size and capacity necessary for delivering sufficient power in themselves during periods of acceleration. Flywheels also have the advantage of receiving energy generated during braking of the vehicle so that such energy that is normally dissipated as heat and not reused can be regenerated in the flywheel for subsequent delivery during peak load demands during acceleration. However, flywheels have the disadvantage of a reduction in the output speed of rotation as the energy is being dissipated, which is usually during periods of vehicle acceleration when rotational speeds are increasing otherwise. Furthermore, most flywheels require operation of the internal combustion engine.  
      The systems known to the inventor require operation of the internal combustion engine at some speed to move the vehicle. However, there are times when the vehicle will operate most efficiently at very low speeds, such as when creeping in traffic, when moving on a slippery surface, such as ice or mud, when being parked or the like. Operation of an engine at such low speeds is inefficient and wasteful of gasoline.  
      There is a need for a motor vehicle which can move when the internal combustion motor is not activated so the motor vehicle can conserve gasoline as well as operate efficiently at low speeds.  
     SUMMARY OF THE INVENTION  
      The above-discussed disadvantages of the prior art are overcome by an engine system for a motor vehicle which combines a battery-powered system with an internal combustion system so that, at low speeds, the battery-powered system is used to drive the vehicle while at high speeds the internal combustion engine drives the vehicle. The battery-powered system includes a flywheel.  
      Other systems, methods, features, and advantages of the invention will be, or will become, apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the invention, and be protected by the following claims.  
    
    
     BRIEF DESCRIPTION OF THE DRAWING FIGURES  
      The invention can be better understood with reference to the following drawings and description. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Moreover, in the figures, like referenced numerals designate corresponding parts throughout the different views.  
       FIG. 1  is a schematic showing a front wheel drive combined battery-powered/internal combustion engine embodying the present invention.  
       FIG. 2  is a schematic showing a detail of the schematic of  FIG. 1 .  
       FIG. 3  is a schematic showing a rear wheel drive combined battery-powered/internal combustion engine embodying the present invention.  
       FIG. 4  is a schematic showing a detail of the schematic of  FIG. 3 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      Referring to the figures, it can be understood that the present invention is embodied in a combined battery-powered/internal combustion engine  10 . System  10  comprises a motor vehicle  12  having a first axle  14  which is a front axle when the motor vehicle is in use and a second axle  16  when the motor vehicle is in use. Vehicle tires  18  are mounted on the axles.  
      A drive shaft  30  has a first end  32  which is a front end when the drive shaft is in use and a second end  34  which is a rear end when the drive shaft is in us. The drive shaft extends between the front axle and the rear axle of the motor vehicle. A flywheel  40  is connected to the front axle of the motor vehicle for rotation therewith. Flywheel  40  includes a multiplicity of gear teeth  44  thereon.  
      A starter motor  50  is mounted on the drive shaft and includes a drive gear  52  operably connected thereto to be driven by the starter motor when the starter motor is activated. Drive gear  52  includes a multiplicity of gear teeth that operably engage the gear teeth on the flywheel to drive the flywheel when the starter motor is activated.  
      A power source  60 , such as a battery, is mounted on the drive shaft. The battery can be the battery of the motor vehicle or connected to battery  62  of the motor vehicle. A switch  70  is electrically interposed between the starter motor and the power source and electrically connects the power source to the starter motor to activate the starter motor when the switch is in an “on” position.  
      When the starter is activated, front axle  14  is rotated by the battery-powered system whereby engine E of the motor vehicle need not be engaged, thereby saving fuel for those situations, such as vehicle creeping, when vehicle speed is so low that it will be inefficient to operate the vehicle using engine E.  
      A second form of the combined battery-powered/internal combustion engine of the present invention is shown in  FIGS. 3 and 4  as system  10 ′ in which flywheel  40 ′ is connected to rear axle  16  of the motor vehicle for rotation therewith. Flywheel  40 ′ can be located adjacent to differential D of the motor vehicle on the rear axle of the motor vehicle, and can be oriented to be perpendicular to the gear of the starter motor.  
      While various embodiments of the invention have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible within the scope of this invention. Accordingly, the invention is not to be restricted except in light of the attached claims and their equivalents.