The Auto Channel
The Largest Independent Automotive Research Resource
The Largest Independent Automotive Research Resource
Official Website of the New Car Buyer

DST And EDST Fan Drives Provide Variable Speed Cooling

25 January 2000

DST And EDST Fan Drives Provide Variable Speed Cooling For Rear Engine And Off-Highway Applications

    INDIANAPOLIS--Jan. 24, 2000--DST and EDST fan drives, offered by BorgWarner Cooling Systems, provide reliable variable speed cooling for engines with limited air-flow, such as rear engine transit buses, concrete mixers and off-highway equipment.
    Unlike traditional viscous fan clutches, which are activated by the radiator core air temperature, the DST (Direct Sensing Technology) fan drives respond directly to temperature changes in engine coolant, charge air, engine oil, transmission fluid and hydraulic oil.
    DSTs are air actuated, using a temperature-sensing pressure regulator valve located in the cooling water jacket to generate a variable air pressure signal. EDSTs (Electronic Direct Sensing Technology) use an electrical signal directly from the engine ECM, which commands the fan to run at the speeds required to maintain proper coolant, oil and charge air temperatures.
    These fan drives are true modulating fan drives, running only as fast as required to stabilize engine temperature. Their gradual engagement drastically reduces shock loads on the engine's pulley and belts.
    Replacing conventional fan drives with direct sensing technology products, where appropriate, results in enhanced fuel economy, since the fan is used only when it is needed and remains at an energy-efficient low speed at all other times. These drives also provide lower system noise levels and longer engine life, resulting from the elimination of thermal shocks to the engine.
    "We provide DSTs and EDSTs for a variety of applications around the world," explained Bruce A. Dufour, Senior Vice President, Sales and Marketing of BorgWarner Cooling Systems. "The technology is perfect for certain applications, such as those with constrained air circulation."
    In addition to rear-engine applications, such as transit buses and some concrete mixers, these fan drives work well on engines that often operate in a stationary mode and engines that run at a relatively constant, heavy load. Bucket trucks, mobile cranes, refuse collection trucks and heavy haul operators are all candidates for DST or EDST fan drives. These fan drives are also appropriate for heavy duty trucks whose operator needs air conditioning while using the sleeper cab.
    BorgWarner Cooling Systems produces fan clutches, fan drives, radiator shutters and fans for light, medium and heavy duty truck, off-highway and industrial applications.
    Chicago-based BorgWarner Automotive, Inc. is a product leader in highly engineered components and systems primarily for vehicle powertrain applications worldwide. The company has 12,000 employees and operates 54 manufacturing and technical facilities in 13 countries. Customers include Navistar, Sterling, Freightliner, Peterbilt, Caterpillar, John Deere, Ford, DaimlerChrysler, General Motors, Toyota, and VW Group. The Internet address for BorgWarner Automotive is: http://www.bwauto.com/