Reciprocating Engine Construction Flashcards
The foundation of an engine is the crankcase and is usually made in two halves.
CRANKCASE SECTION
It contains the bearings and bearing
supports in which the crankshaft
revolves.
CRANKCASE SECTION
must provide a tight enclosure for the
lubricating oil and must support various
external and internal mechanisms of the
engine.
CRANKCASE SECTION
provides support for attachment
of the cylinder assemblies, and the
powerplant to the aircraft.
CRANKCASE SECTION
It must be sufficiently rigid and strong
to prevent misalignment of the
crankshaft and its bearings.
CRANKCASE SECTION
____________________is
generally used for crankcase
construction because it is light and
strong.
Cast or forged aluminum alloy
The unbalanced centrifugal and inertia
forces of the crankshaft acting through
the main bearings subject the crankcase
to _________ which change
continuously in direction and magnitude.
bending moments
The ________ is subjected to many
variations of mechanical loads and other
forces.
crankcase
Since the __________ are fastened to the
crankcase, the tremendous forces placed
on the ____________ tend to pull the cylinder
off the crankcase.
cylinders,cylinder
The ___________ must have sufficient
stiffness to withstand these bending
moments without major deflections.
crankcase
The shape of the nose or front of the
crankcase section varies considerably. In
general, it is either ______ or __________.
tapered
round
The machined surfaces on which the
cylinders are mounted are called
________________
They are provided with a suitable means
of retaining or fastening the cylinders to
the crankcase.
cylinder pads or cylinder mounting
pads.
The general practice in securing the
cylinder flange to the pad is _______________
to mount
studs in threaded holes in the crankcase.
The inner portion of the cylinder pads
are sometimes _______________________________ to
permit the installation of a large rubber
____________ around the _____________, which
effectively seals the joint between the
cylinder and the crankcase pads against
____________.
chamfered or tapered
O-ring
cylinder skirt
oil leakage
Type of engine crankcase
OPPOSED ENGINE CRANKCASE
RADIAL ENGINE CRANKCASE
Section of radial engine crankcase
nose section
main or power section
diffuser or supercharger section
accessory section
A typical horizontally opposed engine
crankcase consists of two halves of cast
aluminum alloy that are manufactured
either with sand castings or by using
permanent molds.
OPPOSED ENGINE CRANKCASE
It is mounted at the front of a radial
engine crankcase and bolts directly to
the power section.
nose section
The____________ usually houses and
supports a propeller governor drive
shaft, the propeller shaft, a cam ring,
and a propeller reduction gear assembly
nose section
It represents the section of the crankcase
where the reciprocating motion of the
pistons is converted to the rotary motion
of the crankshaft. It supports crankshaft
bearings, where cylinders are mounted.
main or power section
Located behind the power section and is
generally made of cast aluminum alloy
or magnesium.
DIFFUSER OR SUPERCHARGER
SECTION
This section houses the supercharger
and its related components.
DIFFUSER OR SUPERCHARGER
SECTION
It provides housing
for attachments of induction pipes and
manifold pressure lines.
DIFFUSER OR SUPERCHARGER
SECTION
DIFFUSER OR SUPERCHARGER
SECTION is also known as
“fuel induction and
distribution section”.
A typical __________houses gear
trains containing both spur- and
bevel-type gears that drive various
engine components and accessories.
accessory section
what re the components that can be seen from an accessory section
mounting pads for fuel pump, oil
pump, tachometer generators
