3. About innovation discovery
Its 500 cc 4 stroke air-cooled engine produces
maximum output of 6.5 bhp @ 3600 rpm and 1.48
kgm @ 2500 rpm.
It is available with various important features like 4
speed gear box, fuel tank capacity of 14.25 ltr (reserve
1.25 ltr) etc.
Its 1370 mm wheelbase provides better grip on road
assuring safest riding in any road condition.
Fatigue of long journey can easily be avoided with the
relaxing seat and spacious foot rest.
10. Universal joint
A universal joint, U joint, Cardan
joint, Hardy-Spicer joint, or
Hooke's joint is a joint in a rigid
rod that allows the rod to 'bend' in
any direction, and is commonly
used in shafts that transmit rotary
motion. It consists of a pair of
hinges located close together,
oriented at 90° to each other,
connected by a cross shaft
11. Drive shaft
A drive shaft, driving shaft, propeller shaft, or Cardan
shaft is a mechanical component for transmitting
torque and rotation, usually used to connect other
components of a drive train that cannot be connected
directly because of distance or the need to allow for
relative movement between them.
Drive shafts are carriers of torque: they are subject to
torsion and shear stress, equivalent to the difference
between the input torque and the load. They must
therefore be strong enough to bear the stress, whilst
avoiding too much additional weight as that would in
turn increase their inertia.
13. AdvantagesDisadvantages
Advantages
* Drive system is less likely to become jammed or broken, a common problem
with chain-driven bicycles
* The use of a gear system creates a smoother and more consistent pedaling
motion
* The rider cannot become dirtied from chain grease or injured by the chain
from "Chain bite", which occurs when clothing or even a body part catches
between the chain and a sprocket
* Lower maintenance than a chain system when the drive shaft is enclosed in a
tube, the common convention
* More consistent performance. Dynamic Bicycles claims that a drive shaft
bicycle consistently delivers 94% efficiency, whereas a chain-driven bike can
deliver anywhere from 75-97% efficiency based on condition.
* Greater clearance: with the absence of a derailleur or other low-hanging
machinery, the bicycle has nearly twice the ground clearance
* For bicycle rental companies, a drive-shaft bicycle is less prone to be stolen,
since the shaft is non-standard, and both noticeable and non-maintainable. This
type of bicycle is in use in several major cities of Europe, where there have been
large municipal funded, public (and automatic) bicycle rental projects.
14. AdvantagesDisadvantages
Disadvantages
* A drive shaft system weighs more than a chain system,
usually 1-2 pounds heavier
* At optimum upkeep, a chain delivers greater efficiency
* Many of the advantages claimed by drive shaft's proponents
can be achieved on a chain-driven bicycle, such as covering the
chain and gears with a metal or plastic cover
* Use of lightweight derailleur gears with a high number of
ratios is impossible, although hub gears can be used
* Wheel removal can be complicated in some designs (as it is
for some chain-driven bicycles with hub gears).
16. Motorcycle drive shafts
Drive shafts have been used on motorcycles almost as long as there have been
motorcycles. As an alternative to chain and belt drives, drive shafts offer relatively
maintenance-free operation and long life. A disadvantage of shaft drive on a
motorcycle is that gearing is needed to turn the power 90° from the shaft to the
rear wheel, losing some power in the process. On the other hand, it is easier to
protect the shaft linkages and drive gears from dust, sand and mud.
The best known motorcycle manufacturer to use shaft drive for a long time —
since 1923 — is BMW. Among contemporary manufacturers, Moto Guzzi is also
well-known for its shaft drive motorcycles. The British company, Triumph and all
four Japanese brands, Honda, Suzuki, Kawasaki and Yamaha, have produced
shaft drive motorcycles.
Motorcycle engines positioned such that the crankshaft is longitudinal and parallel
to the frame are often used for shaft driven motorcycles. This requires only one
90° turn in power transmission, rather than two. Moto Guzzi, BMW, Triumph, and
Honda use this engine layout.
Motorcycles with shaft drive are subject to shaft effect where the chassis climbs
when power is applied. This is counteracted with systems such as BMW's
Paralever, Moto Guzzi's CARC and Kawasaki's Tetralever
17. Drive shaft for Research and
Development (R&D)
The automotive industry also uses drive shafts
at testing plants. At an engine test stand a
drive shaft is used to transfer a certain speed /
torque from the combustion engine to a
dynamometer. A "shaft guard" is used at a
shaft connection to protect against contact
with the drive shaft and for detection of a shaft
failure. At a transmission test stand a drive
shaft connects the prime mover with the
transmission.
18. Principal of diesel engine
1. Suction stroke - Air and vaporised fuel
are drawn in
2. Compression stroke - Fuel vapor and air
are compressed and ignited
3. Power stroke - Fuel combusts and
piston is pushed downwards
4. Exhaust stroke - Exhaust is driven out
20. DIESEL ENGINE MOTOR CYCLE
In India, motorcycles built by Royal Enfield
could be bought with 325 cc single-cylinder
diesel engines due to the fact that diesel was
much cheaper than petrol (gasoline) at the
time, and of more reliable quality. These
engines were noisy and unrefined and not very
popular because of lower performance and
higher weight penalties and also the unique
kick-starting techniques. The engine were
originally designed for use in commercial
applications such as electric generators and
water pumps
21. Enfield Diesel
Its 325 cc 4 stroke air-cooled engine produces maximum output of 6.5 bhp
@ 3600 rpm and 1.48 kgm @ 2500 rpm.
It is available with various important features like 4 speed gear box, fuel
tank capacity of 14.25 ltr (reserve 1.25 ltr) etc.
Its 1370 mm wheelbase provides better grip on road assuring safest riding
in any road condition.
Fatigue of long journey can easily be avoided with the relaxing seat and
spacious foot rest.
22. TECHNICAL SPECIFICATIONS OF
ENFIELD DIESEL
Engine
Type 4 stroke, air-cooled
Displacement 325cc
Bore x stroke 78x68mm
Max. bhp 6.5bhp@3600rpm
Max. torque 1.48kgm@2500rpm
Fuel Consumption 70kmpl under normal riding conditions at 40
kmph
Vehicle
Electricals 12V ac/dc
Wheel base 1370mm
Fuel tank capacity 14.25 lt (1.25 lt. reserve)
Front tyre 3.25"x19"
Rear tyre 3.25"x19"
Transmission Four-speed gear box
23. How diesel engines work
The diesel internal combustion engine differs from the gasoline powered Otto cycle by using a higher compression of the air to ignite the fuel
rather than using a spark plug ("compression ignition" rather than "spark ignition").
In the diesel engine, only air is introduced into the combustion chamber. The air is then compressed with a compression ratio typically between
15 and 22 resulting into a 40 bar (about 600 psi) pressure compared to 14 bar (about 200 psi) in the gasoline engine. This high compression
heats the air to 550 °C (about 1000 °F). At about this moment (the exact moment is determined by the fuel injection timing of the fuel system),
fuel is injected directly into the compressed air in the combustion chamber. This may be into a (typically toroidal) void in the top of the piston or a
'pre-chamber' depending upon the design of the engine. The fuel injector ensures that the fuel is broken down into small droplets, and that the
fuel is distributed as evenly as possible. The more modern the engine, the smaller, more numerous and better distributed are the droplets. The
heat of the compressed air vaporises fuel from the surface of the droplets. The vapour is then ignited by the heat from the compressed air in the
combustion chamber, the droplets continue to vaporise from their surfaces and burn, getting smaller, until all the fuel in the droplets has been
burnt. The start of vaporisation causes a delay period during ignition, and the characteristic diesel knocking sound as the vapour reaches ignition
temperature and causes an abrupt increase in pressure above the piston. The rapid expansion of combustion gases then drives the piston
downward, supplying power to the crankshaft.[7]
As well as the high level of compression allowing combustion to take place without a separate ignition system, a high compression ratio greatly
increases the engine's efficiency. Increasing the compression ratio in a spark-ignition engine where fuel and air are mixed before entry to the
cylinder is limited by the need to prevent damaging pre-ignition. Since only air is compressed in a diesel engine, and fuel is not introduced into
the cylinder until shortly before top dead center (TDC), premature detonation is not an issue and compression ratios are much higher.
Fuel delivery
A vital component of all diesel engines is a mechanical or electronic governor which regulates the idling speed and maximum speed of the engine
by controlling the rate of fuel delivery. Unlike Otto-cycle engines, incoming air is not throttled and a diesel engine without a governor can not have
a stable idling speed and can easily overspeed, resulting in its destruction. Mechanically governed fuel injection systems are driven by the
engine's gear train. [8] These systems use a combination of springs and weights to control fuel delivery relative to both load and speed. [8]
Modern, electronically controlled diesel engines control fuel delivery by use of an electronic control module (ECM) or electronic control unit
(ECU). The ECM/ECU receives an engine speed signal, as well as other operating parameters such as intake manifold pressure and fuel
temperature, from a sensor and controls the amount of fuel and start of injection timing through actuators to maximize power and efficiency and
minimize emissions. Controlling the timing of the start of injection of fuel into the cylinder is a key to minimizing emissions, and maximizing fuel
economy (efficiency), of the engine. The timing is measured in degrees of crank angle of the piston before top dead center. For example, if the
ECM/ECU initiates fuel injection when the piston is 10 degrees before TDC, the start of injection, or timing, is said to be 10° BTDC. Optimal timing
will depend on the engine design as well as its speed and load. Advancing the start of injection (injecting before the piston reaches TDC) results
in higher in-cylinder pressure and temperature, and higher efficiency, but also results in elevated engine noise and increased oxides of nitrogen
(NOx) emissions due to higher combustion temperatures. Delaying start of injection causes incomplete combustion, reduced fuel efficiency and
an increase in exhaust smoke, containing a considerable amount of particulate matter and unburned hydrocarbons .
25. Major advantages
Diesel engines have several advantages over other internal combustion
engines.
* They burn less fuel than a gasoline engine performing the same
work, due to the engine's high efficiency and diesel fuel's higher energy
density than gasoline.[9]
* They have no high-tension electrical ignition system to attend to,
resulting in high reliability and easy adaptation to damp environments.
* They can deliver much more of their rated power on a continuous
basis than a gasoline engine.
* The life of a diesel engine is generally about twice as long as that of
a gasoline engine [10] due to the increased strength of parts used, also
because diesel fuel has better lubrication properties than gasoline.
* Diesel fuel is considered safer than gasoline in many applications.
Although diesel fuel will burn in open air using a wick, it will not explode
and does not release a large amount of flammable vapour.
26. Major advantages
* For any given partial load the fuel efficiency (kg
burned per kWh produced) of a diesel engine
remains nearly constant, as opposed to gasoline
and turbine engines which use proportionally more
fuel with partial power outputs. [11][12][13][14]
* They generate less waste heat (btu) in cooling
and exhaust.[9]
* With a diesel, boost pressure is essentially
unlimited.
* The carbon monoxide content of the exhaust is
minimal, therefore diesel engines are used in
underground mines.
27. Emissions
Diesel engines produce very little carbon monoxide as they burn the fuel in excess
air even at full load, at which point the quantity of fuel injected per cycle is still
about 50% lean of stoichiometric. However, they can produce black soot (or more
specifically diesel particulate matter) from their exhaust, which consists of
unburned carbon compounds. This is caused by local low temperatures where the
fuel is not fully atomized. These local low temperatures occur at the cylinder walls
and at the outside of large droplets of fuel. At these areas where it is relatively
cold, the mixture is rich (contrary to the overall mixture which is lean). The rich
mixture has less air to burn and some of the fuel turns into a carbon deposit.
Modern car engines use a diesel particulate filter (DPF) to capture carbon
particles and then intermittently burn them using extra fuel injected into the
engine.
The full load limit of a diesel engine in normal service is defined by the "black
smoke limit". Beyond which point the fuel cannot be completely combusted, as the
"black smoke limit" is still considerably lean of stoichiometric. It is possible to
obtain more power by exceeding it, but the resultant inefficient combustion means
that the extra power comes at the price of reduced combustion efficiency, high fuel
consumption and dense clouds of smoke. This is only done in specialized
applications (such as tractor pulling competitions) where these disadvantages are
of little concern
28. Emissions
Likewise, when starting from cold, the engine's combustion
efficiency is reduced because the cold engine block draws heat
out of the cylinder in the compression stroke. The result is that
fuel is not combusted fully, resulting in blue/white smoke and
lower power outputs until the engine has warmed through. This is
especially the case with indirect injection engines, which are less
thermally efficient. With electronic injection, the timing and length
of the injection sequence can be altered to compensate for this.
Older engines with mechanical injection can have mechanical
and hydraulic governor control to alter the timing, and multi-phase
electrically controlled glow plugs, that stay on for a period after
start-up to ensure clean combustion—the plugs are automatically
switched to a lower power to prevent them burning out.
29. Emissions
Particles of the size normally called PM10 (particles of 10
micrometres or smaller) have been implicated in health
problems, especially in cities. Some modern diesel
engines feature diesel particulate filters, which catch the
black soot and when saturated are automatically
regenerated by burning the particles. Other problems
associated with the exhaust gases (nitrogen oxides, sulfur
oxides) can be mitigated with further investment and
equipment; some diesel cars now have catalytic
converters in the exhaust.
All diesel engine exhaust emissions can be significantly
reduced by the use of biodiesel fuel. Oxides of nitrogen do
increase from a vehicle using biodiesel, but they too can
be reduced to levels below that of fossil fuel diesel, by
changing fuel injection timing.
30. Power and torque
For commercial uses requiring towing, load carrying and other
tractive tasks, diesel engines tend to have better torque
characteristics. Diesel engines tend to have their torque peak
quite low in their speed range (usually between 1600–2000
rpm for a small-capacity unit, lower for a larger engine used in
a truck). This provides smoother control over heavy loads
when starting from rest, and, crucially, allows the diesel
engine to be given higher loads at low speeds than a gasoline
engine, making them much more economical for these
applications. This characteristic is not so desirable in private
cars, so most modern diesels used in such vehicles use
electronic control, variable geometry turbochargers and
shorter piston strokes to achieve a wider spread of torque
over the engine's speed range, typically peaking at around
2500–3000 rpm.
31. Safety
The diesel engine is a very safe type of
engine. Diesel engines are equipped with a
mechanical or electronic governor to control
minimum and maximum rpm[8], which
makes Diesel engine runaway unlikely. The
fuel is barely flammable so fire risk is low.
33. SINGLE CYLINDER ENGINES
A single cylinder engine produces three main vibrations. In describing them we will assume that the cylinder
is vertical.
Firstly, in an engine with no balancing counterweights, there would be an enormous vibration produced by the
change in momentum of the piston, gudgeon pin, connecting rod and crankshaft once every revolution.
Nearly all single-cylinder crankshafts incorporate balancing weights to reduce this.
While these weights can balance the crankshaft completely, they cannot completely balance the motion of
the piston, for two reasons. The first reason is that the balancing weights have horizontal motion as well as
vertical motion, so balancing the purely vertical motion of the piston by a crankshaft weight adds a horizontal
vibration. The second reason is that, considering now the vertical motion only, the smaller piston end of the
connecting rod (little end) is closer to the larger crankshaft end (big end) of the connecting rod in mid-stroke
than it is at the top or bottom of the stroke, because of the connecting rod's angle. So during the 180° rotation
from mid-stroke through top-dead-center and back to mid-stroke the minor contribution to the piston's
up/down movement from the connecting rod's change of angle has the same direction as the major
contribution to the piston's up/down movement from the up/down movement of the crank pin. By contrast,
during the 180° rotation from mid-stroke through bottom-dead-center and back to mid-stroke the minor
contribution to the piston's up/down movement from the connecting rod's change of angle has the opposite
direction of the major contribution to the piston's up/down movement from the up/down movement of the
crank pin. The piston therefore travels faster in the top half of the cylinder than it does in the bottom half,
while the motion of the crankshaft weights is sinusoidal. The vertical motion of the piston is therefore not
quite the same as that of the balancing weight, so they can't be made to cancel out completely.
Secondly, there is a vibration produced by the change in speed and therefore kinetic energy of the piston.
The crankshaft will tend to slow down as the piston speeds up and absorbs energy, and to speed up again as
the piston gives up energy in slowing down at the top and bottom of the stroke. This vibration has twice the
frequency of the first vibration, and absorbing it is one function of the flywheel.
Thirdly, there is a vibration produced by the fact that the engine is only producing power during the power
stroke. In a four-stroke engine this vibration will have half the frequency of the first vibration, as the cylinder
fires once every two revolutions. In a two-stroke engine, it will have the same frequency as the first vibration.
This vibration is also absorbed by the flywheel.
34. Piston
A piston is a component of
reciprocating engines, pumps
and gas compressors. It is
located in a cylinder and is made
gas-tight by piston rings. In an
engine, its purpose is to transfer
force from expanding gas in the
cylinder to the crankshaft via a
piston rod and/or connecting rod.
In a pump, the function is
reversed and force is transferred
from the crankshaft to the piston
for the purpose of compressing
or ejecting the fluid in the
cylinder. In some engines, the
piston also acts as a valve by
covering and uncovering ports in
the cylinder wall.
36. Gudgeon pin
In internal combustion engines, the gudgeon pin (UK, wrist pin US) is that
which connects the piston to the connecting rod and provides a bearing for
the connecting rod to pivot upon as the piston moves.[1] In very early
engine designs (including those driven by steam and also many very large
stationary or marine engines), the gudgeon pin is located in a sliding
crosshead that connects to the piston via a rod.
The gudgeon pin is typically a forged short hollow rod made of a steel alloy
of high strength and hardness that may be physically separated from both
the connecting rod and piston or crosshead.[1] The design of the gudgeon
pin, especially in the case of small, high-revving automotive engines is
challenging. The gudgeon pin has to operate under some of the highest
temperatures experienced in the engine, with difficulties in lubrication due to
its location, while remaining small and light so as to fit into the piston
diameter and not unduly add
37. Connecting rod
In a reciprocating piston engine, the connecting rod or conrod
connects the piston to the crank or crankshaft. The connecting
rod was invented sometime between 1174 and 1200 when a
Muslim inventor, engineer and craftsman named al-Jazari built
five machines to pump water for the kings of the Turkish Artuqid
dynasty — one of which incorporated the connecting rod.
Transferring rotary motion to reciprocating motion was made
possible by connecting the crankshaft to the connecting rod,
which was described in the "Book of Knowledge of Ingenious
Mechanical Devices". The double-acting reciprocating piston
pump was the first machine to offer automatic motion,[1] but its
mechanisms and others such as the cam, would also help intitiate
the Industrial Revolution.
39. Crankshaft
The crankshaft, sometimes casually abbreviated to crank, is the part of an engine
which translates reciprocating linear piston motion into rotation. To convert the
reciprocating motion into rotation, the crankshaft has "crank throws" or
"crankpins", additional bearing surfaces whose axis is offset from that of the crank,
to which the "big ends" of the connecting rods from each cylinder attach.
It typically connects to a flywheel, to reduce the pulsation characteristic of the four-
stroke cycle, and sometimes a torsional or vibrational damper at the opposite end,
to reduce the torsion vibrations often caused along the length of the crankshaft by
the cylinders farthest from the output end acting on the torsional elasticity of the
metal.
The crank-connecting rod system was first fully developed in two of an Arab
inventor Al-Jazari’s (1136-1206) water raising machines in 1206[1][2]. Similar
crankshafts were later described by Conrad Keyser (d. 1405), Francesco di
Giorgio (1439–1502), Leonardo da Vinci (1452–1519), and by Taqi al-Din in 1551.
[3] A Dutch "farmer" Cornelis Corneliszoon van Uitgeest also described a
crankshaft in 1592. His wind-powered sawmill used a crankshaft to convert a
windmill's circular motion into a back-and-forward motion powering the saw.
Corneliszoon was granted a patent for the crankshaft in 1597.
41. Bearings
The crankshaft has a linear axis about which it rotates,
typically with several bearing journals riding on
replaceable bearing (the main bearings) held in the
engine block. As the crankshaft undergoes a great
deal of sideways load from each cylinder in a
multicylinder engine, it must be supported by several
such bearings, not just one at each end. This was a
factor in the rise of V8 engines, with their shorter
crankshafts, in preference to straight-8 engines. The
long crankshafts of the latter suffered from an
unacceptable amount of flex when engine designers
began using higher compression ratios and higher
rotational speeds. High performance engines often
have more main bearings
42. Piston ring
A piston ring is an open-ended ring that fits into a
groove on the outer diameter of a piston in a
reciprocating engine such as an internal combustion
engine or steam engine.
The three main functions of piston rings in
reciprocating engines are:
1. Sealing the combustion/expansion chamber.
2. Supporting heat transfer from the piston to the
cylinder wall.
3. Regulating engine oil consumption.
The gap in the piston ring compresses to a few
thousandths of an inch when inside the cylinder bore.
44. Electromagnetic coils
An electromagnetic coil (or simply a
"coil") is formed when a conductor
(usually a solid copper wire) is
wound around a core or form to
create an inductor or electromagnet.
One loop of wire is usually referred to
as a turn, and a coil consists of one
or more turns. For use in an
electronic circuit, electrical
connection terminals called taps are
often connected to a coil. Coils are
often coated with varnish and/or
wrapped with insulating tape to
provide additional insulation and
secure them in place. A completed
coil assembly with taps etc. is often
called a winding. A transformer is an
electromagnetic device that
46. Flywheel
A flywheel is a mechanical device
with a significant moment of inertia
used as a storage device for
rotational energy. Flywheels resist
changes in their rotational speed,
which helps steady the rotation of the
shaft when a fluctuating torque is
exerted on it by its power source
such as a piston-based
(reciprocating) engine, or when the
load placed on it is intermittent (such
as a piston pump). Flywheels can be
used to produce very high power
pulses as needed for some
experiments, where drawing the
power from the public network would
produce unacceptable spikes. A
small motor can accelerate the
flywheel between the pulses.
Recently, flywheels have become the
subject of extensive research as
power storage devices for uses in
vehicles; see flywheel energy
storage.
47. Clutch
A clutch is a mechanism for transmitting rotation,
which can be engaged and disengaged. Clutches are
useful in devices that have two rotating shafts. In
these devices, one shaft is typically driven by a motor
or pulley, and the other shaft drives another device. In
a drill, for instance, one shaft is driven by a motor, and
the other drives a drill chuck. The clutch connects the
two shafts so that they can either be locked together
and spin at the same speed (engaged), or be
decoupled and spin at different speeds (disengaged).
48. Multiple plate friction clutch
This type of clutch has several driving members
interleaved with several driven members. It is used in
motorcycles and in some diesel locomotives with
mechanical transmission. It is also used in some
electronically-controlled all-wheel drive systems. This
is the most common type of clutch on modern types of
vehicles. When the brake is pushed the caliper
containing piston pushes the pad towards the brake
disc which slows the wheel down. On the brake drum
it is similar as when the handbrake is pulled the
cylinder pushes the brake shoes towards the drum
which also slows the wheel down.
49. Fuel pump
A fuel pump is a frequently (but not always) essential component
on a car or other internal combustion engined device. Many
engines (older motorcycle engines in particular) do not require
any fuel pump at all, requiring only gravity to feed fuel from the
fuel tank through a line or hose to the engine. But in non-gravity
feed designs, fuel has to be pumped from the fuel tank to the
engine and delivered under low pressure to the carburetor or
under high pressure to the fuel injection system. Often,
carbureted engines use low pressure mechanical pumps that are
mounted outside the fuel tank, whereas fuel injected engines
often use electric fuel pumps that are mounted inside the fuel
tank (and some fuel injected engines have two fuel pumps: one
low pressure/high volume supply pump in the tank and one high
pressure/low volume pump on or near the engine).
50. SINGLE CYLINDER PUMP
These are inline pumps used for
small low speed Diesel Engine. The
flange mounted fuel injection pump
is cam-operated, spring return
plunger pump of constant-stroke.
The fuel delivery is controlled by the
angular displacement of the plunger
with regulating edge according to
the instantaneous output charge of
the diesel engines. The angular
displacement of the plunger is
derived from the regulating bar
acting on the plunger control sleeve.
51. Fuel injection
Fuel injection is a system for mixing fuel with air in an internal combustion
engine. It has become the primary fuel delivery system used in gasoline
automotive engines, having almost completely replaced carburetors in the late
1980s. The first use of direct gasoline injection was on the Hesselman engine
invented by Swedish engineer Jonas Hesselman in 1925.[1][2]
A fuel injection system is designed and calibrated specifically for the type(s) of
fuel it will handle. Most fuel injection systems are for gasoline or diesel
applications. With the advent of electronic fuel injection (EFI), the diesel and
gasoline hardware has become similar. EFI's programmable firmware has
permitted common hardware to be used with different fuels. Carburetors were the
predominant method used to meter fuel on gasoline engines before the
widespread use of fuel injection. A variety of injection systems have existed since
the earliest usage of the internal combustion engine.
The primary difference between carburetors and fuel injection is that fuel injection
atomizes the fuel by forcibly pumping it through a small nozzle under high
pressure, while a carburetor relies on low pressure created by intake air rushing
through it to add the fuel to the airstream.
The fuel injector is only a nozzle and a valve: the power to inject the fuel comes
from a pump or a pressure container farther back in the fuel supply.
53. Cylinder head
In an internal combustion engine, the cylinder head sits above the
cylinders and consists of a platform containing part of the
combustion chamber and the location of the valves and spark
plugs. In a flathead engine, the mechanical parts of the valve train
are all contained within the block, and the head is essentially a
flat plate of metal bolted to the top of the cylinder bank with a
head gasket in between; this simplicity leads to ease of
manufacture and repair, and accounts for the flathead engine's
early success in production automobiles and continued success
in small engines, such as lawnmowers. This design, however,
requires the incoming air to flow through a convoluted path, which
limits the ability of the engine to perform at higher rpm, leading to
the adoption of the overhead valve head design.
In the overhead valve head, the top half of the cylinder head
contains the camshaft in an overhead cam engine, or another
mechanism (such as rocker arms and pushrods) to transfer
rotational mechanics from the crankshaft to linear mechanics to
operate the valves (pushrod engines perform this conversion at
the camshaft lower in the engine and use a rod to push a rocker
arm that acts on the valve). Internally the cylinder head has
passages called ports for the fuel/air mixture to travel to the inlet
valves from the intake manifold, for exhaust gases to travel from
the exhaust valves to the exhaust manifold, and for antifreeze to
cool the head and engine.
The number of cylinder heads in an engine is a function of the
engine configuration. A straight engine has only one cylinder
head. A V engine usually has two cylinder heads, one at each end
of the V, although Volkswagen, for instance, produces a V6 called
the VR6, where the angle between the cylinder banks is so
narrow that it utilizes a single head. A boxer engine has two
heads.
The cylinder head is key to the performance of the internal
combustion engine, as the shape of the combustion chamber,
inlet passages and ports (and to a lesser extent the exhaust)
determines a major
55. Electric starter
The modern starter motor is either a permanent-magnet or a series- or series-parallel wound direct current
electric motor with a solenoid switch (similar to a relay) mounted on it. When current from the starting battery
is applied to the solenoid, usually through a key-operated switch, it pushes out the drive pinion on the starter
driveshaft and meshes the pinion with the ring gear on the flywheel of the engine. Before the advent of key-
driven starters, most electric starters were actuated by foot-pressing a pedestal located on the floor, generally
above the accelerator pedal.
The solenoid also closes high-current contacts for the starter motor, which begins to turn. Once the engine
starts, the key-operated switch is opened, a spring in the solenoid assembly pulls the pinion gear away from
the ring gear, and the starter motor stops. The starter's pinion is clutched to its driveshaft through an
overrunning sprag clutch which permits the pinion to transmit drive in only one direction. In this manner, drive
is transmitted through the pinion to the flywheel ring gear, but if the pinion remains engaged (as for example
because the operator fails to release the key as soon as the engine starts), the pinion will spin independently
of its driveshaft. This prevents the engine driving the starter, for such backdrive would cause the starter to
spin so fast as to fly apart. However, this sprag clutch arrangement would preclude the use of the starter as a
generator if employed in hybrid scheme mentioned above; unless modifications are made.
This overrunning-clutch pinion arrangement was phased into use beginning in the early 1960s; before that
time, a Bendix drive was used. The Bendix system places the starter drive pinion on a helically-cut driveshaft.
When the starter motor begins turning, the inertia of the drive pinion assembly causes it to ride forward on
the helix and thus engage with the ring gear. When the engine starts, backdrive from the ring gear causes the
drive pinion to exceed the rotative speed of the starter, at which point the drive pinion is forced back down the
helical shaft and thus out of mesh with the ring gear.
56. Camshaft
The camshaft is an
apparatus often
used in piston
engines to operate
poppet valves. It
consists of a
cylindrical rod
57. Rocker arm
Generally referred to within the internal combustion engine of automotive,
marine, motorcycle and reciprocating aviation engines, the rocker arm is
a reciprocating lever that conveys radial movement from the cam lobe
into linear movement at the poppet valve to open it. One end is raised
and lowered by the rotating lobes of the camshaft (either directly or via a
lifter (tappet) and pushrod) while the other end acts on the valve stem.
When the camshaft lobe raises the outside of the arm, the inside presses
down on the valve stem, opening the valve. When the outside of the arm
is permitted to return due to the camshafts rotation, the inside rises,
allowing the valve spring to close the giver.
The effective leverage of the arm (and thus the force it can exert on the
valve stem) is determined by the rocker arm ratio, the ratio of the
distance from the rocker arm's center of rotation to the tip divided by the
distance from the center of rotation to the point acted on by the camshaft
or pushrod.
For car engines the rocker arms are generally steel stampings, providing
a reasonable balance of strength, weight and economical cost. Because
the rocker arms are part of the reciprocating weight of the engine,
excessive mass limits the engine's ability to reach high operating speeds.
60. Transmission
Using the principle of mechanical advantage, a transmission or
gearbox provides a speed-torque conversion (commonly known
as "gear reduction" or "speed reduction") from a higher speed
motor to a slower but more forceful output or vice-versa.
Uses
Gearboxes have found use in a wide variety of different—often
stationary—applications, such as wind turbines.
Transmissions are also used in agricultural, industrial,
construction, mining and automotive equipment. In addition to
ordinary transmission equipped with gears, such equipment
makes extensive use of the hydrostatic drive and electrical
adjustable-speed drives.
61. Crown Wheel and Pinion
A crown wheel is a wheel with cogs or teeth set at right angles to its plane and the pinion
is a small cogwheel that meshes with the crown wheel. The pinion thread is specially
made on the thread grinder to ensure proper fitting. Tooth contact of a crown pinion is
inspected on a Gleason machine at regular intervals of time for uniform hardness and
adequate case depth. They are checked thoroughly for high spots because this ensures
premature failure and noise-free operation. The crown wheel & pinion are paired and
checked for centralized tooth bearing and desired proximity. An elliptoid contact pattern
is ensured between the crown wheel and pinion. They are made of fine-grained steel
billet.
Features
Crown wheel and pinion usually have the following features:
* Excellent heat distortion control
* High strength
* Wear resistance property and
* Noiseless and vibration free operation.
In a machine, when any torque is applied to the drive unit, the tendency is for the crown
wheel and pinion to be forced into or out of mesh by the sliding contact. The amount of
pre-load on the bearings determines how much torque can be transmitted without
allowing end float, which cause the meshing of the gears to become incorrect.
Application
Crown wheel & pinion are used widely in automotive industries. They are one of the most
stress prone parts of a vehicle. They are used in automobiles to maintain forward
motion. To maintain forward motion both output drive shaft sides covers are removed
and the pinion and crown wheel are swapped completely with differential.
64. drum brake
The brake shoe carries the brake lining, which is
riveted or glued to the shoe. When the brake is
applied, the shoe moves and presses the lining
against the inside of the drum. The friction between
lining and drum provides the braking effort and energy
is dissipated as heat.
Modern cars have disc brakes all round, or discs at the
front and drums at the rear. An advantage of discs is
that they can dissipate heat more quickly than drums
so there is less risk of overheating.
The reason for retaining drums at the rear is that a
drum is more effective than a disc as a parking brake.
65. Air filter
An air filter is a device which removes solid particulates such as
dust, pollen, mold, and bacteria from the air. Air filters are used in
applications where air quality is important, notably in building
ventilation systems and in engines, such as internal combustion
engines, gas compressors, diving air compressors, gas turbines
and others.
Some buildings, as well as aircraft and other man-made
environments (e.g., satellites and space shuttles) use foam,
pleated paper, or spun fiberglass filter elements. Another method
uses fibers or elements with a static electric charge, which attract
dust particles. The air intakes of internal combustion engines and
compressors tend to use either paper, foam, or cotton filters. Oil
bath filters have fallen out of favor. The technology of air intake
filters of gas turbines has improved significantly in recent years,
due to improvements in the aerodynamics and fluid-dynamics of
the air-compressor part of the Gas Turbines.
66. Battery (electricity)
In electronics, a battery or voltaic cell is a combination of one
or more electrochemical Galvanic cells which store chemical
energy. These cells create a voltage difference between the
terminals of the battery. When an external electrical circuit is
connected to the battery, then the battery drives an electric
current through the circuit and electrical work is done. Since
the invention of the first Voltaic pile in 1800 by Alessandro
Volta, the battery has become a common power source for
many household and industrial applications, and is now a
multi-billion dollar industry.
The name "battery" was coined by Benjamin Franklin for an
arrangement of multiple Leyden jars (an early type of
capacitor) after a battery of cannon.[1] Common usage
includes a single electrical cell in the definition
67. Oil filter
An oil filter is a filter to remove contaminants from
engine oil, transmission oil, lubricating oil, or hydraulic
oil. Oil filters are used in many different types of
hydraulic machinery. A chief use of the oil filter is in
internal-combustion engines in on- and off-road motor
vehicles, light aircraft, and various naval vessels.
Other vehicle hydraulic systems, such as those in
automatic transmissions and power steering, are
often equipped with an oil filter. Gas turbine engines,
such as those on jet aircraft, require the use of oil
filters. And oil production, transport, and recycling
facilities employ filters.
