Flywheels, vehicle

See also Batteries Capacitors and Ultracapacitors Electric Motor Systems Emission Control, Vehicle Environmental Problems and Energy Use Flywheels Fuel Cells Fuel Cell Vehicles Flybrid Vehicles Materials Transportation, Evolution ofEnergy Use and. 

Fig. 5.15 Principle of operation of a vehicle using a flywheel as auxiliary energy storage...

In this section, the main characteristics of alternative electrical energy storage systems, such flywheels and super capacitors, are described, as these devices might play an important role in the development of vehicles powered by electric propulsion systems. 

However, the use of flywheels needs to take into consideration also their safety due to the consequence of a breaking of the flywheel, which can be made more likely by the gyroscopic effect of the rotating disk [39], or of a crush of the vehicle currying a rotating flywheel on board. In this case, without the proper precautions, the flywheel energy would be released almost instantly with dangerous consequences. 

There is a large number of possible variations for the parallel hybrid configuration, besides that shown in Fig. 5.18, proposed by most of the major automobile companies. Some of them, for example, have a small electric machine in line with the crankshaft, where is usually located the flywheel in a IC engine vehicle. Another parallel hybrid configuration has the IC engine and the electric drive connected to different axles, as shown in Fig. 5.19, in particular in this case the IC engine drives the front wheels, the electric system the rear wheels and the road... 

Super capacitors and flywheels, as high power storage systems, can be used in a wide range of hybrid vehicles, combined with one or more power energy devices. 

Fig. 5.21 Configuration of electric vehicle equipped with flywheel and batteries...

As part of an interdisciplinary study we are working on emission control catalysis for an extended parallel hybrid concept [1-5]. The main elements of the experimental car developed at the Swiss Federal Institute of Technology are the combustion engine, operating in a fixed cycle mode, a flywheel as a short term energy storage device, an electrical machine and a continuous variable transmission. One of the features of this hybrid vehicle is the so called intermittent... 

As a part of an interdisciplinary study [2] we are working on emission control catalysis for an extended hybrid concept (fig. 1). The heart of this hybrid system is a flywheel, equipped with a continuous variable transmission. This permits the flywheel to be accelerated with the intermittently operated combustion engine or the electrical engine independently of the speed of the vehicle. The flywheel is then used to accelerate the car and to store braking energy. The fl)nvheel concept allows the recuperation of... 

Some important adaptations of a wheel used in mechanical engineering are gear, pulley, flywheel, turbine, grinding wheel, and automobile wheel. For transportation purpose, wheels are used in combination with axles. An axle is a cylindrical component on which either the wheel can be fixed or is free to rotate about the central axis of axle. If the wheel is fixed on the axle, the axle is supported on bearings and is free to rotate. In the wheels of railway car and some vehicles, the axle is fixed to the wheels and both wheel and the axle rotate in unison. In some vehicles, the axle is fixed on the vehicle and the wheels rotate around the axle. In order to reduce the friction at the wheel-axle interface, rolling-element bearings may be used. 

At this stage of development, it is doubtful whether a flywheel incorporated in an electrical highway vehicle can replace lead acid batteries due to problems with vibration and safety, but the performance of a lead acid battery deteriorates in hot wet conditions, requires frequent maintenance and has a life expectancy of only about 4 years. The aim of US Flywheel Systems, however, is to drive a car with a flywheel system. It is reckoned that some 16 units would be required to fulfil this objective and adequate protection would have to be supplied, since, in the event of a wheel disintegrating, it would dissipate its energy into hot fluff and high speed dust. A very sophisticated computer control system is used to filament wind each wheel with a high fiber content of 86% w/w [89]. 

Mellor, P.H., N. Schofield, and D. Howe. 2000. Flywheel and ES peak power buffer technologies. Proceedings of IEEE Conference on Electric, Hybrid and Fuel Cell Vehicles, 8/1-8/5. 

The other major bus demonstration programs are Georgetown University (100 kW stack from XCELLSIS, 40 ft., Novabus RTS platform, Lockheed martin control system electric drive, vehicle system controller by Booz-Allan Hamilton, Comp, hydrogen, 2000), MAN (120 kW stack from Siemens, 36 ft. Comp, hydrogen 1999), NeoPlan (80 kW DeNora stack, 100 kW flywheel, 36 ft, 2000), Toyota and Hino Motors (63 seater, low floor Comp, hydrogen). 

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