IDG OIL SYSTEM.
The IDG has a self contained oil system except for the heat-exchanger. Positive displacement scavenge pumps pump the oil (via the IDG filter) to the aircraft heat exchanger and return it to the IDG.
The charge oil supply of cleaned, cooled deaerated oil is provided as a bus.
This oil supply feeds:
The lubrication jets are individually supplied.
The deaerator supercharges the inlet of the charge pump with solid oil.
The charge pump pressurizes the oil against the charge relief valve.
It provides thus regulated supply pressures to:
A differential pressure indicator is provided to show when the filter element is clogged. The sensing device for the differential pressure is automatically suppressed during cold oil running conditions: this avoids spurious operation due to high oil viscosity.
Similarly, a cooler by-pass valve is fitted within the IDG.
The valve opens on a rising pressure to short circuit the cooler during cold oil operation.
A scavenge pump relief valve limits the supply pressure of the scavenge system.
A vent valve releases internal case pressure if necessary.
A quick fill coupling situated on the transmission casing enables pressure filling or topping up the unit with oil.
The oil thus introduced flows to the transmission via the scavenge filter and external cooler circuit. This ensures:
the priming of the external circuit
the filtration of any oil introduced.
An internal standpipe connected to an overflow drain ensures a correct quantity of oil.
You can read the oil level through two sight glasses located on the IDG.
One sight glass serves for the CFM 56 engine, the other one for the V 2500 engine.
Oil temperature sensors monitor the temperature of both the input and output oil: they allow overheat detection.
A pressure switch operates in the event of a loss of the charge oil pressure.
In both cases (overheat and loss of pressure) a warning is provided to the cockpit.
Vocabulary.
The oil system - [ɔɪl ˈsɪstɪm] – система смазки
the heat-exchanger [hiːt-ɪkˈsʧeɪnʤə] – теплообменник
the displacement [dɪsˈpleɪsmənt] – перемещение
scavenge [ˈskævɪnʤ] - откачивать
the pump [pʌmp] – насос
deaerat [ˈdeəreɪt] - деаэрировать
the control piston [kənˈtrəʊl pɪstən] - поршень
the governor [ˈgʌvənə] – регулятор
the jet- сопло, форсунка, струя
pressurize [ˈpreʃəraɪz] – нагнетать
the relief valve [rɪˈliːf vælv] - предохранительный клапан
clogged [klɒgd] – забитый
the differential hydraulic unit [dɪfəˈrenʃəl haɪˈdrɔːlɪk ˈjuːnɪt] -дифференциальная гидромашина
suppress [səˈpres] – подавлять
spurious [ˈspjʊərɪəs] – непредусмотренный
the viscosity [vɪsˈkɔsɪtɪ] – вязкость
the by-pass valve [ˈbaɪpɑːs vælv] - перепускной клапан
the vent valve [vent vælv] - выпускной клапан
the priming [ˈpraɪmɪŋ] - заправка, заливка, заполнение
the sight glass [saɪt glɑːs] - смотровое стекло
the detection [dɪˈtekʃn] – обнаружение
the pressure switch [ˈpreʃə swɪʧ] - сигнализатор давления
the warning [ˈwɔːnɪŋ] – предупреждение
Exercise 1.
Give English equivalents.
Автономная система, генератор со встроенным приводом, объёмный, насос, фильтр, очищенное масло, удалять воздух, смазка, форсунка, дозаправка маслом, фильтр засорен, насос откачки масла, труба, дренаж, уровень масла, манометр температуры масла, обнаруживать перегрев, сигнализатор давления
Exercise 2.
Fill in the gaps with the words.
A pressure switch, pressurizes, deaerated , ensures, clogged, releases, self contained, positive displacement, limits, monitor
The IDG has a … oil system.
The oil is cleaned, cooled, …
… scavenge pumps pump the oil (via the IDG filter) to the aircraft heat exchanger.
The charge pump …. the oil against the charge relief valve.
A differential pressure indicator is provided to show when the filter element is …
A scavenge pump relief valve … the supply pressure of the scavenge system.
A vent valve … internal case pressure if necessary.
An internal standpipe connected to an overflow drain … a correct quantity of oil.
Oil temperature sensors …. the temperature of both the input and output oil: they allow overheat detection.
… operates in the event of a loss of the charge oil pressure.
Exercise 3.
Answer the questions.
What is the function of positive displacement scavenge pumps?
What kind of oil is provided as a bus?
What does the oil supply feed?
What does the deaerator supercharge?
How does the charge pump work?
What indicator is provided to show when the filter element is clogged?
What is a scavenge pump relief valve for?
What does an internal standpipe connected to an overflow drain ensures?
What does the sight glass serve for?
When does a pressure switch operate?
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