초록 ▼

The disclosure teaches an improvement in a free turbine type engine which comprises a power limit unit. The unit includes a first sensor for measuring pressure at the turbine inlet, and a second sensor for measuring temperature at the turbine inlet. A third means provides a measurement indicative of

The disclosure teaches an improvement in a free turbine type engine which comprises a power limit unit. The unit includes a first sensor for measuring pressure at the turbine inlet, and a second sensor for measuring temperature at the turbine inlet. A third means provides a measurement indicative of turbine exhaust pressure and may be a sensor located in the exhaust duct which is downstream of the turbine or may comprise means for providing outside ambient pressure readily available from existing aircraft instrumentation, e.g., altimeter. A processor means calculates shaft horse power (SHP) from the above measurements. Other means are provided for generating a reference signal, and the reference signal is compared with SHP. When SHP is greater than the reference signal, then fuel to the engine is controlled to reduce engine power. The unit can also be adapted for calculating torque, and for reducing the torque when the torque is greater than the reference level. The invention also relates to a method for limiting power or torque using the above apparatus.

대표청구항 ▼

In a free turbine engine, which engine includes a power turbine having an inlet, an exhaust duct downstream of said turbine, an output shaft and a control valve for controlling engine power, the improvement comprising a power limit unit; said unit comprising: first sensor means for measuring pressur

In a free turbine engine, which engine includes a power turbine having an inlet, an exhaust duct downstream of said turbine, an output shaft and a control valve for controlling engine power, the improvement comprising a power limit unit; said unit comprising: first sensor means for measuring pressure at said inlet, said first sensor means being disposed in said power turbine inlet; second sensor means for measuring temperature at said inlet, said second sensor means being disposed in said turbine inlet; third sensor means for measuring power turbine exhaust pressure, said third sensor means being disposed in said duct; processor means for calculating shaft horse power (SHP) from the measurements of said first, second and third sensor means; means for generating a reference signal; comparator means, for comparing SHP with said reference signal, said comparator means having output means; the output means being connected to said control valve; whereby, to reduce engine power when SHP is greater than said reference signal.