Accession Number : ADD005150

Title :   Fan Drive System.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE ARMY WASHINGTON D C

Personal Author(s) : Rio,Russell L

Report Date : 13 Dec 1977

Pagination or Media Count : 5

Abstract : A variable speed fan drive mechanism for an engine coolant system controlled by temperature and fan speed signals. The mechanism includes a hydrostatic pump-motor unit (hydrostatic transmission) powered by the engine, for transmitting power to the fan. Mechanical signals related to coolant temperature and fan speed are supplied to a comparator mechanism that delivers a mechanical output control signal. The output control signal is magnified and applied as a control force to vary the displacement of the pump in the hydrostatic unit. The comparator mechanisms has the effect of negating engine speed as a control force. Thus, high engine speeds (that would tend to produce unduly large hydraulic flows through the pump-motor circuit) are reflected in high fan speed signals fed into the comparator mechanism, which produces a 'corrected' output signal that appropriately reduces pump dislacement to thus reduce the fan speed to low energy consumption levels. (Author)

Descriptors :   *Patents, *Fans, *Drives, Output, Control systems, Velocity

Subject Categories : Air Condition, Heating, Lighting & Ventilating

Distribution Statement : APPROVED FOR PUBLIC RELEASE