TM 1-1500-204-23-3
WARNING
Drycleaning solvent is flammable
and solvent vapors are toxic. Use
P-D-680, Type II Solvent in a well-
ventilated area. Keep away from
open flames. Avoid prolonged
solvent contact with skin.
1
Screen-type. The screen-
type, as shown in figure 3-6, with its double-walled
construction, provides a large filtering area in a compact
unit. As oil passes through the fine-mesh screen, dirt,
sediment, and other foreign matter are removed and
settle to the bottom of the housing. At regular intervals,
the cover is removed and the screen and housing
cleaned with a drycleaning solvent, P-D-680, Type II.
2
Cuno-type. The Cuno oil
filter has a cartridge made of disks and spacers. A
cleaner blade fits between each pair of disks. The
cleaner blades are stationary, but the disks rotate when
the shaft is turned. Oil from the pump enters the
cartridge well that surrounds the cartridge and passes
through the spaces between the closely spaced disks of
the cartridge, then through the hollow center, and on to
the engine. Any foreign particles in the oil are deposited
on the outer surface of the cartridge. When the
cartridge is rotated, the cleaner blades comb the foreign
matter from the disks. The cartridge of the manually-
operated Cuno filter is turned by an external handle.
Automatic Cuno filters have a hydraulic motor build into
the filter head. This motor, operated by engine oil
pressure, rotates the cartridge whenever the engine is
running. There is a manual turning nut on the automatic
Cuno filter for rotating the cartridge manually during
inspections.
3
Air-maze-type. The Air-
maze filter contains a series of round, fine-meshed
screens mounted on a hollow shaft. The oil from the
pump enters the well, surrounds the screens, and then
passes through them and the shaft before entering the
engine. The carbon deposits that collect on the screens
actually improve their filtering efficiency.
(b)
Turbine engines. Filters are an
important part of the lubrication system, since they
remove foreign particles that may be in the oil. This is
particularly important in gas turbines, as very high
engine speeds are attained, and the antifriction types of
ball and roller bearings would become damaged quite
rapidly if lubricated with contaminated oil. Also, there
are usually a number of drilled or core passages leading
to various points of lubrication Since these passages are
usually rather small, they are easily clogged. The
spacers and screens and main oil strainer are explained
in the following paragraphs.
1
Spacers
and
screens.
This filter, as shown in figure 3-7, is made up of a stack
of metal disks covered with a screen and separated by
spacers so that the oil can flow through the screens and
out the outlet port of the strainer body.
Figure 3-6. Oil Filter
3-9
