Bosch has made the EVOII mechanical vacuum pump lighter and much more efficient, putting it on a par with more expensive electric vacuum pumps. The Bosch EVOII offers the best value for money on the market and reliably provides the vacuum for the brake booster, the company claims. The unit costs up to 75% less than comparable electric pumps, and offers CO2 emissions of less than 0.4 grams per kilometer. In addition, the unit is contained within the engine compartment, so the driver hears nothing.
|EVOII. Click to enlarge.|
Bosch revised its tried-and-tested pump, of which it has manufactured 45 million units to date, from the ground up. This new generation is 300 grams lighter than other mechanical vacuum pumps, and more than a kilogram lighter than electric ones. The difference is the thermoplastic rotor: its stable blades can create the necessary vacuum, while overall the unit weighs very little.
The functional principle of the mechanical vacuum pump has been established for diesel engines for a long time. In recent years, there has also been a growing need for vacuum in modern gasoline engines due to the spread of gasoline direct injection, which in combination with engine downsizing reduces fuel consumption by up to 15%. As of 2013, some 40% of all new cars in Europe had direct fuel injection. Modern direct fuel injection systems need an additional pump, since the vacuum can no longer be controlled by the throttle valve.
The EVOII is designed in such a way that it provides the necessary amount of vacuum while still creating the least amount of friction of any product on the market. The efficient design of housing and rotating elements is the result of intensive simulations and calculations. By changing certain parameters, Bosch is able to find an optimized solution for every engine application.
The new generation of vacuum pumps can be tailored to each customer and engine application. Depending on customer requirements, the Bosch vacuum pump can be driven by the crank- or camshaft, a gear or a chain. It can also be integrated with an oil or a fuel pump.