Hydraulics for economics

The design of a digitally controlled hydraulic fan drive from Denison Hydraulics is said to help diesel engines run leaner and cleaner.

One of the keys to properly and efficiently controlling emissions from diesel powered on- and off-highway machinery is maintaining the engine's optimum operating temperature. That fact plus a very important secondary benefit, reducing fuel usage, can be achieved by using an infinitely variable hydraulic fan drive.

A recent solution to reducing emissions, adapted by a majority of engine suppliers to both the on- and off-highway market, has been the introduction of an electronic gas-recirculation (EGR) system. While relatively effective at reducing emissions, the EGR solution also causes considerable parasitic power loss on the engine, resulting in higher fuel consumption. As an on-highway example, an EGR system adds $5000 to $7000 per Class-8 truck application. These costs include such items as variable geometry turbochargers, additional intercoolers, and specialized valves.