说New words

•        Spline花键

•        Foreignmatter 异物、外来物

•        Bearinghousing 轴承座

•        Non-corrosionresistant material 非耐腐蚀材料

•        Deterioration变质

•        Recirculatory再循环

•        Oiltank 油箱

•        Expendable消耗品

•        Spill 溢出

•        Cockpit座舱、驾驶舱

•        Spring弹簧

•        Feedpressure 供油压力

•        Alleviate缓解

•        Strainer滤网、过滤器

•        Debris碎片

•        Filter过滤器

•        Oilstarvation 缺油

•        Viscosity粘度

•        Cockpit座舱、驾驶舱

•        Spring弹簧

•        Feedpressure 供油压力

•        Alleviate缓解

•        Strainer滤网、过滤器

•        Debris碎片

•        Filter过滤器

•        Oilstarvation 缺油

•        Viscosity粘度

•        Piston-typepump 活塞泵

•        Draininto 排入

•        Collectortray 集液槽

•        Reservoir储液器

•        Replenish补充

•        Dipstick量油计、油尺

•        Vital 至关重要的

•        Shearneck剪力颈

•        Gerotorpump 摆线泵

•        Intermeshing互相啮合

•        Slot 狭槽

•        Endface 端面

•        Cylinderbore 气缸孔

•        Churning搅动

•        Windage风阻

•        Baffleplate 挡板、折流板

•        Convey传递

•        Magneticplug 磁性堵头

•        Chipdetector 探屑器

•        Squeezefilm 挤压油膜

•        Dampen阻尼

•        Coarsestrainer 粗滤网

•        Thread-typefilter 螺纹式油滤

•        Mineralcrude oil 矿物原油

•        Syntheticoil 合成油

读Sentence

•        1. Thelubrication system is required to provide lubrication and cooling for allgears, bearings and splines. It must also be capable of collecting foreignmatter which, if left in a bearing housing or gearbox, can cause rapid failure.Additionally, the oil must protect the lubricated components which aremanufactured from non-corrosion resistant materials. The oil must accomplishthese tasks without significant deterioration.

•        6 Fig.8-1 shows the pressure relief valve system for a turbo-propeller engine andindicates the basic components that comprise an engine lubrication system. Theoil pressure pump draws oil from the tank through a strainer which protects thepump gears from debris which may have entered the tank, Oil is then deliveredthrough a pressure filter to the pressure relief valve which maintains aconstant oil delivery pressure to the feed jets in the bearing chambers. Someengines may have an additional relief valve (pressure limiting valve) which isfitted at the oil pressure pump outlet. This valve is set to open at a muchhigher value than the pressure relief valve to return the oil to the inlet sideof the oil pressure pump in the event of the system becoming blocked. A similarvalve may also be fitted across the pressure filter to prevent oil starvationof the bearing chambers should the filter become partially blocked or the oilhaving a high viscosity under cold starting conditions preventing sufficientflow through the filter. Provision is also made to supply oil to the propellerpitch control system, reduction gear and torquemeter system. Scavenge pumpsreturn the oil to the tank via the oil cooler. On entering the tank, the oil isde-aerated ready for recirculation.

•        10.For engines which run for periods of short duration, such as booster andvertical lift engines, the total loss oil system is generally used. The systemis 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 flowto the bearings by a plunger-type pump, indirectly driven from the compressorshaft; on others it is delivered by a piston-type pump operated by fuelpressure (fig. 8-3). In the latter, the oil supply is automatically selected bythe high pressure fuel shut-off valve (cock) during engine starting and isdelivered as a single shot to the front and rear bearings. On some enginesprovision is made for a second shot to be delivered to the rear bearing only,after a predetermined period.

•        13.The oil pumps are vital to the efficient operation of the engine. Failure ofthe pumps will necessitate a rapid shutdown of the engine. For this reason, theoil pump drive shafts do not incorporate a weak shear-neck (Part 7) because theymust continue to supply oil for as long as possible, regardless of damage.

•        17.Since a small quantity of incompressible oil becomes trapped in the gear mesh,which can cause a hydraulic lock and possible pump damage, a relief slot ismachined into the end faces of the casing to provide an escape route for theoil.

•        24.The fuel-cooled oil cooler incorporates a bypass valve fitted across the oilinlet and outlet. The valve operates at a pre-set pressure difference acrossthe cooler and thus prevents engine oil starvation in the event of a blockage.A pressure maintaining valve is usually located in the feed line of the coolerwhich ensures that the oil pressure is always higher than the fuel pressure. Inthe event of a cooler internal fault developing, the oil will leak into thefuel system rather than the potentially dangerous leakage of fuel into the oilsystem.

•        32.The choice of a lubricating oil is initially decided by the need to start theengine at very low temperatures, when the viscosity of the oil is high, whilstbeing able to survive in an engine environment which exhibits very hightemperatures. Having met these fundamental requirements, the need to provideimproved lubrication characteristics using additives must also be investigated.Special laboratory and engine tests are done to prove the suitability of aparticular oil for a specific type of engine. Assessments are made as theextent to which it deteriorates and the corrosive effects it may have on theengine.

 

读全文并回答以下问题：

•       Whatare the design requirements of turboprop lubrication system?

•       Definethe classification and difference of recirculatory systems.

•       Whatare the characteristics of the full flow system?

•       Describethe working principle of the total loss system.

•       Whatis the function of the vent?

•       Whatare the advantages of low viscosity synthetic oils?