A total loss (expendable) oil system,Total loss (expendable) system :

Total loss (expendable) system :

Fig. 8-3 A total loss (expendable) oil system.

10. For engines which run for periods of short duration, such as booster and vertical lift engines,the total loss oil system is generally used. The system is simple and incurs low weight penalties
because it requires no oil cooler, scavenge pump or filters. On some engines oil is delivered in a
continuous flow to the bearings by a plunger-type pump, indirectly driven from the compressor shaft; on
others it is delivered by a piston-type pump operated by fuel pressure (fig. 8-3).

A pressure relief valve type oil system,Pressure relief valve system,INTRODUCTION,Lubrication

Lubrication :

INTRODUCTION :

Fig. 8-1 A pressure relief valve type oil system.

1. The lubrication system is required to provide lubrication and cooling for all gears, bearings and

splines. It must also be capable of collecting foreign matter which, if left in a bearing housing or gearbox,

can cause rapid failure. Additionally, the oil must protect the lubricated components which are manu-

fractured from non-corrosion resistant materials. The oil must accomplish these tasks without significant

deterioration.

2. The requirements of a turbo-propeller engine are somewhat different to any other types of aero gas
turbine. This is due to the additional lubrication of the heavily loaded propeller reduction gears and the
need for a high pressure oil supply to operate the propeller pitch control mechanism.

3. Most gas turbine engines use a self-contained re circulatory lubrication system in which the oil is
distributed around the engine and returned to the oil tank by pumps. However, some engines use a
system known as the total loss or expendable system in which the oil is spilled overboard after the engine
has been lubricated.

LUBRICATING SYSTEMS