AMT 124 RECIPROCATING ENGINE (MIDTERM) Flashcards
commonly used in radial engines.
master-and-articulated rod assembly
cylindrical plunger that moves up and down.
Pistons
As many as _____ may be machined around a piston.
Six ring grooves
Foundation of a reciprocating engine
Crankcase
It has rings which seal the gases in the cylinder, preventing any loss of power around the sides of the _____.
Piston
The master-and-articulated rod assembly is commonly used in _____
Radial engines.
it primary functions; draw fuel and air into a cylinder, compress the gases, and purge burned exhaust gases from the cylinder.
Pistons
Provides tight enclosure for the lubricating oil
Crankcase
with this type of assembly, one piston in each row of cylinders is connected to the crankshaft by a _______
Master rod.
It forms a link between the piston and the crankshaft.
connecting rod
All crankshafts require at least two ____ to support the crankshaft, absorb the operational loads, transmit stress from the crankshaft to the crankcase.
main journals
The remaining pistons are connected to the master rod by ______
articulated rods.
contains the engine’s integral parts
Crankcase
one end of a ____ connects to the crankshaft is called the crankpin end, while the other end connects to the piston is called piston end.
connecting rod
The connecting rod forms a link between the ___ and the ____.
piston and the crankshaft
it second function; transmit the force produced by combustion to the crankshaft
Pistons
it serve as attachment points for the connecting rods.
Crankpins, or connecting-rod bearing journals
one end of a connecting rod connects to the crankshaft is called the _______, while the other end connects to the piston is called ____
Crankpin end, piston end
The basic major components of a reciprocating engine are the:
crankcase, cylinders, pistons, connecting rods, valves, spark plugs, and crankshaft.
Therefore, in a nine cylinder engine there is ______ and ______, while a double row 18 cylinder engine has ____ and _______.
one master rod and eight articulating rods, two master rods and 16 articulating rods.
machine aluminum alloy forging
Pistons
Most _____ are forged directly into a crankshaft and are offset from the main bearing journal.
Crankpins
Mounting surface for the engine cylinders and external accessories
Crankcase
it forms a part of the chamber in which the fuel is compressed and burned.
Cylinder
In the head of each cylinder are the ____ and ___
valves and spark plugs
Four types of connecting rod:
Plain type, Master-and-articulated rod type, fork-and-blade type, split type
are attached to the master rod by knuckle pins, that are pressed into holes in the master rod flanges during assembly, a knuckle pin lock plate is then installed to retain the pins.
Articulated rods
This offset design means that any force applied to a ____ in a direction other than parallel to the crankshaft centerline causes the crankshaft to rotate.
Crankpins, or connecting-rod bearing journals
is used primarily in V-type engines and consists of a fork connecting rod and blade connecting rod.
fork-and-blade rod assembly
One of the valves is in a passage leading from the _____
Induction systems
are required to connect the crankpin to the crankshaft.
Two crank cheeks, or crank arms
extremely rigid, light and strong
crankcase
the other valve is in a passage leading to the
exhaust system
are used in opposed and inline engines
Plain connecting rods
is needed to let the exhaust gases out.
Exhaust valve
The fork-and-blade rod assembly is used primarily in _____ and consists of a ____ and ____.
V-type engines and fork connecting rod and blade connecting rod.
In some designs, the ____ extend beyond the journal to form counterweight that helps balance the crankshaft.
cheek
Cast or forged alloy
Crankcase
Four parts of piston;
Piston head, Ring groves, Piston pin Boss, Piston skirt
it changes the straight line motion of the piston to a rotary turning motion.
crankshaft and connecting rod
Inside each _____ is a movable piston connected to a crankshaft by a connecting rod.
cylinder
Plain connecting rods are used in _____ and ______.
opposed and inline engines.
most ____ have drilled passageways that allow oil to flow from the main journal to the crankpin.
crank cheeks
Inside each cylinder is a movable ____ connected to a ____ by a _______
movable piston, crankshaft, connecting rod.
The ____ is split at the crankpin end to allow space for the blade rod to fir between the prongs.
forked rod
The piston end of a plain connecting rod is fitted with a ____ to accommodate the piston pin.
Bronze bushing
The ____ in an aircraft engine also absorbs the power or work from all the cylinders and transfers it to the propeller.
crankshaft
is needed to let the fuel/air into the cylinder
Intake valve
The fork-and-blade assembly is then fastened to a crankpin with a _____
two-piece bearing
are then cut into a piston’s outside surface to hold a set of piston rings.
Ring grooves
the link which transmits the forge exerted on a piston to a crankshaft
connecting rod
moving within the cylinder, forms one of the walls of the combustion chamber.
Piston
backbone of reciprocating engine
Crankshaft
The ___ is typically pressed into the connecting rod and then reamed to the dimension required by the piston pin.
Bushing
it represent the centerline of a crankshaft and support the crankshaft as it rotates in the _____.
main bearing journals, or main journals
The crankpin end, on the other hand, is usually fitted with a _____ and ___ which is held on the end of the rod by ____ or _____.
two-piece bearing and cap, bolts or studs.
made of forged durable steel alloy
connecting rod
prevent gas from escaping past the piston during engine operation and are placed in the ring grooves immediately below the piston head.
compression rings
are machined from a forged blank
Cylinder barrels
The gap can be a simple _____ with flat faces
butt joint
Main purpose is to transform the reciprocating motion of the piston and connecting rod into rotary motion
Crankshaft
Cylinder barrels are machined from a forged blank, with a ____ that projects into the crankcase and a ____ that is used to attach the cylinder to the crankcase.
skirt, mounting flange.
The number of ___________ used on each piston is determined by the type of engine and its design.
compression rings
acts as a lid on the cylinder barrel to provide an enclosed chamber for combustion.
Cylinder head
an _____ with ____, or a step joint.
angle joint with angled faces, or a step joint.
Forged from a strong alloy such as chromium-nickel molybdenum steel
Crankshaft
The cylinder head acts as a lid on the cylinder barrel to ______
Provide an enclosed chamber for combustion.
Most aircraft engines typically use ____ or ____ on each piston
two or three compression rings
Since the piston rings expand when the engine reaches operating temperature, the ring ______________.
the ring must have specified clearance between the ring gap faces.
however, due to the temperature differences across the cylinder head,
it is necessary to provide more cooling-fin area on various sections of a cylinder head.
The point where a piston ring is split is called the _____.
Piston ring gap
it control the amount of oil that is applied to the cylinder walls as well as prevent oil from entering the combustion chamber.
Oil rings
If the gap is too large, the two forces _______ to provide an adequate seal.
The two forces will not close up enough
Cylinder heads contain ___, ____, ____, and also serve to conduct heat away from the cylinder barrels.
intake and exhaust valve ports, spark plugs, valve actuating mechanisms.
Consist of a main bearing journal, one or more crankpins, and several crank cheeks.
Crankshaft
an _____ will result in the ring faces binding against each other and the cylinder wall causing cylinder wall scoring.
insufficient gap
houses the piston and connecting rod assembly as well as the valves and spark plugs.
Cylinders
The two types of oil rings that are found on most engines are _____ and _____.
Oil control rings and oil scraper rings.
strong enough to withstand the internal pressure developed during engine operation yet be lightweight to minimize engine weight.
Cylinders
Three functions of piston rings in aircraft reciprocating engines;
they prevent leakage of gas pressure from the combustion chamber, reduce oil seepage into the combustion chamber, and transfer heat from the piston to the cylinder walls.
Air-cooled cylinder heads are generally made of either ____ or _____ because aluminum conducts heat well, is lightweight, and it durable.
forged or die-cast aluminum alloy
are placed in the grooves immediately below the compression rings.
Oil control rings
Cooling fins are ____ or _____
cast or machined
it must have good heat-conducting properties for efficient cooling
Cylinders
are cast or machined onto the outside of a cylinder head and provide an effective means of transferring heat from the cylinder head to the surround air.
Cooling fins
It may have one or more oil control rings and, depending on the type of piston, as many as two rings can be installed in a single ring groove.
Pistons
Cylinders must have _______ for efficient cooling
Good-heat conducting properties
On some pistons, ___ are cast into the underside of the piston to provide for greater heat transfer to the engine oil.
cooling fins
Piston pins may be ______, _____, _____.
stationary, semi floating, or full-floating.
The primary purpose of oil control rings is to ___________________.
to regulate the thickness of the oil film on the cylinder wall.
Cylinders consists of a:
Cylinder head, Cylinder barrel, mounting flange, cylinder skirt, cooling fins and valve assembly
As their name implies, ______ are held tightly in place by a set screw that prevents movement.
stationary piston pins
it perform three functions in aircraft reciprocating engines.
Piston Rings
To allow an oil control ring to remove excess oil and return it to the crankcase, ___ are drilled in the piston ring grooves, or ring lands.
small holes
it joins the piston to the connecting rod
Piston pin
are retained stationary in the connecting rod by a set clamp that engages a slot in the pin.
semi floating piston pins
They prevent leakage of gas pressure from the combustion chamber, reduce oil seepage into the combustion chamber, and transfer heat from the piston to the cylinder walls.
Piston Rings
must be comparatively easy and inexpensive to manufacture, inspect, and maintain.
Cylinder assembly
A typical ____ is machined in the form of a tube from a nickel-steel alloy forging that is case=hardened.
Piston Pin
are free to rotate in both connecting rod and the piston, and are used in most modern aircraft engines.
Full-floating piston pins
it consists of a cylinder head, cylinder barrel, mounting flange, cylinder skirt, cooling fins and valve assembly.
Cylinders
The portion of the piston between the ring grooves is commonly referred to as a ____.
Ring land
To help align a piston in a cylinder, the piston base is extended to form the _____.
Piston skirt
If too much oil enters the combustion chamber,
the oil will burn and leave a thick coating of carbon on the combustion chamber walls, the piston head, the spark plugs, and the valves. If this carbon should enter the ring grooves or valve guides it can cause the valves and piston rings to stick.
Piston pins are sometimes called ___ because of the similarity between the relative motions of the piston and the connecting rod and that of the human arm.
wrist pins
The piston’s top surface is called the ___ and is directly exposed to the heat of combustion.
Piston head
provides a combustion chamber where the burning and expansion of gases takes place to produce power
Cylinders
Carbon buildup can cause ______ as well as ____, ___, or _____.
spark plug misfiring as well as detonation, pre ignition, or excessive oil consumption.
is an enlarged area inside the piston that provides additional bearing area for a ______ which passes through the piston pin boss to attach the piston to a connecting rod.
Piston pin boss, piston pin
Carbon buildup can cause spark plug misfiring as well as detonation, pre ignition, or excessive oil consumption. To help prevent this, an ____, sometimes called an _______, is used to regulate the amount of oil that passes between the piston skirt and the cylinder wall.
Oil scraper ring, sometimes called an oil wiper ring.
driven by the crankshaft by way of gear wheels, a toothed belt or a timing chain
Camshaft
are helical-coiled springs that are installed in the cylinder head and provide the force that holds the valve face firmly against the valve seat.
Valve springs
are classified according to their head shape which may come in four basic designs.
Poppet valves
made from cast iron or steel
Camshaft
Most aircraft engines utilize two or more valve springs of different sizes and diameters to prevent a phenomenon called ___ or ___.
valve float or valve surge.
Poppet valves are classified according to their head shape which may come in four basic designs;
Flat-headed valve, semi-tulip valve, tulip valve, and mushroom valve
it opens and closes the inlet and exhaust valves of the engine at the right time, with the exact stroke and in precisely defined sequence.
camshaft
has a flat head and is typically used only as an intake valve in aircraft engines.
flat-head valve
occurs when the frequency of a valve spring begins to vibrate at its resonant frequency. When this occurs, the spring loses its ability to hold the valve closed.
Valve float
A valve face is typically ground to an angle of between __ and ___ to form a seal against the ___ when the valve is closed
30 and 60 degrees, valve seat
A groove is machined around the valve stem near the tip for a _____ or ___ which acts as a lock ring to keep the valve spring retaining washers in place and hold the valve in the cylinder head.
split key or keeper key.
regulates the flow of gases into and out of a cylinder by opening and closing at predetermined times in the combustion process.
Valves
has a slightly concave area on its head.
semi-tulip valve
acts as a pilot to keep the valve head properly aligned as it moves back and forth.
valve stem
is a circular ring of hardened metal that provides a uniform sealing surface for the valve face.
Valve seat
at least on intake valve and one exhaust valve
Valve
The valve springs are held in place by a ________ and a split valve key.
Valve spring retainer
has a deep, wide indented area on its head.
Tulip valve
Controls the amount of fuel/air mixture
Intake valve
Most valve stems are surface hardened to resist wear and are joined to the valve head at the ______
valve neck
A typical valve seat is made of either ___ or ___ and machined to an oversize fit.
bronze or steel
is usually located between the cylinder head and the bottom of the valve spring, while a _______ is installed on the top of the valve spring. The retainer is fitted with a split valve key that locks the valve spring retainer to the valve stem.
valve spring retainer
allows the exhaust gases to exit the cylinder
Exhaust valve
The inside of a cylinder, or ______, is usually machined smooth to a uniform, initial dimension and then honed to a final dimension.
Cylinder bore
have convex heads and are not commonly found on aircraft engines.
mushroom valves
is that portion of the valve that creates a seal at the intake and exhaust ports.
valve face
Some cylinder bores are machined with a slight taper. In other words, the diameter of the top portion of the barrel is slightly smaller than the diameter at the cylinder skirt. This is called _________ and is designed to compensate for the uneven expansion cause by the higher operating temperatures and larger mass near the cylinder head.
Choke bore cylinder
Four basic designs of valve;
Flat-headed valve, semi-tulip valve, tulip valve, and mushroom valve
The exterior of a cylinder barrel consists of several thin ______ that are machined into the exterior cylinder wall and a _______ that are cut at the top of the barrel so that it can be screwed into the cylinder head.
Cooling fins, set of threads
