Striedsberg

[_hainz]

Ho trovato questo:

Striedberg

As an enthusiast of classic British sports cars, I was initially disappointed to learn that India's Tata Motors had inked an accord with Ford Motor Company for the purchase of Jaguar. Then I learned a bit more about the company with such an unlikely moniker.

Although not as venerable as Jaguar, Tata Motors has been selling cars since 1954, and today the company has agreements with the likes of Daimler Benz and Fiat and other mainstream carmakers. Tata also ranks second in India's growing passenger vehicle market, and employs over 1400 engineers and scientists, many of whom are developing environment-friendly electric and hybrid vehicles.

Some of Tata’s latest designs run on biofuels and hydrogen. Needless to say, these cars are a far cry from Jaguar triple-SU-carb petrol guzzlers that I got acquainted with in the late 1950s. In today's changing world, everyone is affected by oil prices, pollution, and climate change.

The fact that Tata is an Indian company underscores the benefits of globalization, doesn’t it? We’re all treated to broader markets and a greater base for original ideas and innovation.

Another foreign company with an out-of-the-ordinary name is Stridberg Powertrain AB. It’s doing interesting state-of-the-art work in Sweden.

Stridberg’s forthcoming hybrid Strigear car is intriguing, to say the least. Weighing in similarly to a Toyota Prius, a Strigear could get over 100 mpg in city traffic. Zero to 60 mph time is rated at a quick 8.6 s.

When compared to a Prius using equal power components, a gasoline- or Diesel-fired Strigear could sip less fuel (as much as 37% less), yet would be capable of as much as 55% higher acceleration. The Strigear gearbox shifts in 30 to 70 ms, which is unnoticeable by the driver.

The Strigear uses two electric motors, and a pretty much conventional 4-cylinder internal combustion engine. The electric motors, developed by Stridsberg for use in SAAB aircraft, are air cooled.

These motors eliminate the cost and bulk of cooling equipment that dominates hybrid designs. Recall that designers of the Prius and other hybrids must deal with inefficient electronics. If the components in a hybrid inverter circuitry can be made to run at higher temperatures, and/or/if better techniques can be found to cool silicon semiconductors and a car’s electric motors, a hybrid cooling system could be made smaller, which would make for a lighter vehicle and better performance. As every EE knows, cooler running electronics also result in higher reliability.

To address the inevitability of wasted energy as heat, some hybrid makers are considering semiconductors fabbed from materials such as silicon carbide.

SiC semiconductors can withstand high temperatures and switch rapidly. Most hybrid car designers reluctantly resort to water-cooling or air-cooled heat exchangers. Tom Watson, in his role as hybrid systems propulsion manager at Ford, confirms that a prime engineering goal for his team is to cut the heat generated by the electronics and to totally eliminate the hybrid Escape’s costly and complex battery-cooling system.

A Cool Approach

For its part, Strigear’s unique architecture contributes to efficiency without resorting to new semiconductor technologies or wasteful cooling schemes. In planetary systems such as those found in the Prius or General Motor Dual Mode, part of the engine power passes both electric motors on its way from engine to tire. Stridsberg claims that’s what spoils efficiency.

The Strigear dual electric motors act differently. One motor works as an engine flywheel, while the other feeds the input shaft of the car’s actuator-controlled gearbox (actuators move control surfaces and doors in aircraft; Stridsberg makes those as well). Stridsberg’s scheme routes engine power to vehicle wheels without passing any electric motor.

From an emission standpoint, Stridsberg’s design really shines. The company says a Strigear-equipped Volvo V70, for example, would emit 78 g of CO2/km instead of the present 231 g, a 66% reduction. A Strigear-based Volvo CX90 would emit 107 g of CO2/km instead of 282 g.

Have you ever heard of Stridsberg Powertrain? Do you have experience with hybrid automobile design? Comments? Questions? Write me at amm at en-genius dot net, or post your comments on our blog.

Actually Making Hybrids Green

Immagino che l'abbiano brevettato....

E' anche strano che i motori siano raffreddati ad aria (se ho capito bene)

Modificato 21 Novembre 2010 da J-Gian