Patent US5. 34. 39.Hybrid electric vehicle.BACKGROUND OF THE INVENTION1.Field of the Invention.This invention is in the field of hybrid electric vehicles incorporating both an internal combustion engine, such as a gasoline engine, and an electric motor as sources of torque to drive the vehicle.SVz7A26GzgI.jpg' alt='Hitachi Ac Remote Control Manual' title='Hitachi Ac Remote Control Manual' />More particularly, this invention relates to a hybrid electric vehicle that is fully competitive with presently conventional vehicles as regards performance, operating convenience, and cost, while achieving substantially improved fuel economy and reduced pollutant emissions.Discussion of the Prior Art.For many years great attention has been given to the problem of reduction of fuel consumption of automobiles and other highway vehicles.Concomitantly very substantial attention has been paid to reduction of pollutants emitted by automobiles and other vehicles.To a degree, efforts to solve these problems conflict with one another.For example, increased thermodynamic efficiency and thus reduced fuel consumption can be realized if an engine is operated at higher temperatures.Razer Game Booster 3 5 6 0 Beta 2012 Olympic Gymnastics .Thus there has been substantial interest in engines built of ceramic materials withstanding higher combustion temperatures than those now in use.However, higher combustion temperatures in gasoline fueled engines lead to increase in certain undesirable pollutants, typically NOx.Another possibility for reducing emissions is to burn mixtures of gasoline and ethanol gasohol or straight ethanol.Hitachi-Air-Conditioner-Service-Manual-13-600x600.jpg' alt='Hitachi Ac Remote Control Manual' title='Hitachi Ac Remote Control Manual' />Quickar Electronics, Inc.ICs. Top Paid Android Games Pack Rar Files on this page. The vehicle of claim 7, wherein said electric motor is an AC motor, said vehicle further comprises solid state switching means, and said battery provides DC to.However, to date ethanol has not become economically competitive with gasoline and consumers have not accepted ethanol to any great degree.One proposal for reducing pollution in cities is to limit the use of vehicles powered by internal combustion engines and instead employ electric vehicles powered by rechargeable batteries.To date, all such electric cars have a very limited range, typically no more than 1.Thus, while there are many circumstances in which the limited range and extended recharge time of the batteries would not be an inconvenience, such cars are not suitable for all the travel requirements of most individuals.Accordingly, an electric car would have to be an additional vehicle for most users, posing a substantial economic deterrent.HT1LEyUFFXcXXagOFbXo/205974945/HT1LEyUFFXcXXagOFbXo.jpg' alt='Hitachi Ac Remote Control Manual' title='Hitachi Ac Remote Control Manual' />Moreover, it will be appreciated that in the United States most electricity is generated in coal fired power plants, so that using electric vehicles merely moves the source of the pollution, but does not eliminate it.Furthermore, comparing the respective net costs per mile of driving, electric vehicles are not competitive with ethanol fueled vehicles, much less with conventional gasoline fueled vehicles.Much attention has also been paid over the years to development of electric vehicles including internal combustion engines powering generators, thus eliminating the defect of limited range exhibited by simple electric vehicles.The simplest such vehicles operate on the same general principle as diesel electric locomotives used by most railroads.In such systems, an internal combustion engine drives a generator providing electric power to traction motors connected directly to the wheels of the vehicle.This system has the advantage that no variable gear ratio transmission is required between the diesel engine and the wheels of the locomotive.More particularly, an internal combustion engine produces zero torque at zero engine speed RPM and reaches its torque peak somewhere in the middle of its operating range.Accordingly, all vehicles driven directly by an internal combustion engine other than certain single speed vehicles using friction or centrifugal clutches, and not useful for normal driving require a multiple speed transmission between the engine and the wheels, so that the engines torque can be matched to the road speeds and loads encountered.Further, some sort of clutch must be provided so that the engine can be decoupled from the wheels, allowing the vehicle to stop while the engine is still running, and to allow some slippage of the engine with respect to the drive train while starting from a stop.It would not be practical to provide a diesel locomotive with a multiple speed transmission, or a clutch.Accordingly, the additional complexity of the generator and electric traction motors is accepted.Electric traction motors produce full torque at zero RPM and thus can be connected directly to the wheels when it is desired that the train should accelerate, the diesel engine is simply throttled to increase the generator output and the train begins to move.The same drive system may be employed in a smaller vehicle such as an automobile or truck, but has several distinct disadvantages in this application.In particular, it is well known that a gasoline or other internal combustion engine is most efficient when producing near its maximum output torque.Typically, the number of diesel locomotives on a train is selected in accordance with the total tonnage to be moved and the grades to be overcome, so that all the locomotives can be operated at nearly full torque production.Moreover, such locomotives tend to be run at steady speeds for long periods of time.Reasonably efficient fuel use is thus achieved.However, such a direct drive vehicle would not achieve good fuel efficiency in typical automotive use, involving many short trips, frequent stops in traffic, extended low speed operation and the like.So called series hybrid electric vehicles have been proposed wherein batteries are used as energy storage devices, so that the engine can be operated in its most fuel efficient output power range while still allowing the electric traction motors powering the vehicle to be operated as required.Thus the engine may be loaded by supplying torque to a generator charging the batteries while supplying electrical power to the traction motors as required, so as to operate efficiently.This system overcomes the limitations of electric vehicles noted above with respect to limited range and long recharge times.However, such series hybrid electric vehicles are inefficient and grossly uneconomical, for the following reasons.In a conventional vehicle, the internal combustion engine delivers torque to the wheels directly.In a series hybrid electric vehicle, torque is delivered from the engine via a serially connected generator, battery charger, inverter and the traction motor.Energy transfer between those components consumes at least approximately 2.Further such components add substantially to the cost and weight of the vehicle.Thus, series hybrid vehicles have not been immediately successful.A more promising parallel hybrid approach is shown in U.S.Pat. Nos. 3,5.Berman et al.In Berman et al an internal combustion engine and an electric motor are matched through a complex gear train so that both can provide torque directly to the wheels.In Berman et al, the internal combustion engine is run in several different modes.Where the output of the internal combustion engine is more than necessary to drive the vehicle first mode operation the engine is run at constant speed and excess power is converted by a first generator speeder to electrical energy for storage in a battery.In second mode operation, the internal combustion engine drives the wheels directly, and is throttled.When more power is needed than the engine can provide, a second motor generator or torquer provides additional torque as needed.The present invention relates to such a parallel hybrid vehicle, but addresses certain substantial deficiencies of the Berman et al design.For example, Berman et al show two separate electric motorgenerators powered by the internal combustion engine to charge batteries and to drive the vehicle forward in traffic.This arrangement is a source of additional complexity, cost and difficulty, as two separate modes of engine control are required, and the operator must control the transition between the several modes of operation.Further the gear train shown by Berman et al appears to be quite complex and difficult to manufacture economically.Berman et al also indicate that one or even two variable speed transmissions may be required see col.Hunt U.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. Archives
November 2017
Categories |