DIFFERENCE BETWEEN CRANKSHAFT AND CAMSHAFT EXPLAINED !!

Crankshafts:

The crankshaft is an engine component that converts the linear (reciprocating) motion of the piston into rotary motion. The crankshaft is the main rotating component of an engine and is commonly made of ductile iron.

All major components of the engine like piston,connecting rod etc. are supported by this shaft.

Construction Of Crankshaft:

A crankshaft is simply the same as an eccentric, except the eccentric is a much smaller diameter than the shaft itself Crankshaft length mainly depends on number of cylinders are present in engine .Firing order also considered while designing the Crankshaft .

Location :  Crankshaft is located in crank case . On Crankshaft, Connecting rods and pistons are mounted. The crankshaft rides on bearings which can wear down over time. The bearings support the crankshaft and also the rods which connect the pistons to the crankshaft.

Applications :It actually part of an engine where the power is available , and this power is transferred in the form of torque to clutch and thereby  gearbox and wheels.The main function is to convert liner motion of the piston to useful rotary motion.

Camshafts:

Camshaft is a part of engine which is responsible for opening and closing of exhaust and inlet valves.As the engines work they need to breathe out exhaust gases and take in fresh air ( charge) for the next cycle to take place . All these processes need to take place at a designated time with respect to each other. These processes are timed through opening and closing of valves and actuation of fuel pumps through a actuating mechanism which is triggered by movement of the crankshaft. The camshaft comes into picture here. The Crankshaft drives through a belt or chain drive the camshaft on which the inlet,exhaust, fuel pump cams are fitted for each unit when the crankshaft rotates it in turn rotates the camshaft which precisely actuate the valve and fuel pumps.

Construction Of Camshafts:

 A camshaft is a long bar with egg-shaped eccentric lobes, one lobe for each valve and fuel injector.

The relationship between the rotation of the camshaft and the rotation of the crankshaft is of critical importance. Since the valves control the flow of the air/fuel mixture intake and exhaust gases, they must be opened and closed at the appropriate time during the stroke of the piston. For this reason, the camshaft is connected to the crankshaft either directly, via a gear mechanism, or indirectly via a belt or chain called a timing belt or timing chain.

Location : Depending on the location of the camshaft, the cam operates the valves either directly or through a linkage of pushrods and rockers. Direct operation involves a simpler mechanism and leads to fewer failures, but requires the camshaft to be positioned at the top of the cylinders.

Applications :This shaft receives the power from crankshaft  (1:2) and operates the engine valves through cam and follower mechanism(generally mushroom headed follower is used to reduce friction b/w cam and follower).

WHY REAR WHEELS IN AUTO-RICKSHAW ARE TILTED OUTWARDS ??

You might have seen that rear wheels of auto rickshaw are tilted outside.What is the purpose of this?Does it not lead to tyre wear?We will all discuss about this here.

First of all we should learn about an amazing concept which is known as "Camber angle." 

Camber angle is the angle made by the wheels of a vehicle; specifically, it is the angle between the vertical axis of the wheels used for steering and the vertical axis of the vehicle when viewed from the front or rear.If the top of the wheel is farther out than the bottom (that is, away from the axle), it is called positive camber; if the bottom of the wheel is farther out than the top, it is called negative camber.So,in case of three wheeler we have positive camber.

Now let us understand why this positive camber is provided in auto rickshaws.
A three wheeler or what we call as auto rickshaw  generally transports a whole lot of passengers.(at least 6 passengers in the passenger bay) in a single trip. That is approximately 360 kg(considering each passenger's mass to be 60 kg). In figure above if you see the image depicting positive camber,you will notice that the tire contact patch is more towards the region near the outside tire wall. This is the scenario when the rickshaw is in unloaded condition. 

Now when the rickshaw gets loaded , the normal force due to the weight of the passengers causes an anticlockwise moment on the axle supporting the wheels, making the wheels to attain neutral or no camber condition. Thus when the vehicle is loaded there is greater contact patch thus better traction.

If the wheels had the neutral camber in the static unloaded condition, during the loaded scenario the wheels will reach the negative camber alignment resulting in reduced contact patch and uneven tire wear(near the inside tire wall).

KNOW WHY 2 STROKE ENGINES ARE USED IN SHIPS !!

Although 2 Stroke Engines create a lot of noise and pollution but still ship engine uses 2 stroke engine for their propulsion.Let us know the reason behind this:

1.)Fuel Selection: 

High grade fuel are more costly as compared to low grade fuel.A two stroke engine can burn low grade fuel oil and hence reduce running cost of the ship.

2.)High Torque:

 2 stroke engine has more torque at low rpm than the 4 stroke. The ship needs the higher torque to keep a constant speed at the lower engine speed. So the ship can cruise at a constant speed without having to constantly adjust the engine speed.

3.)Power:

Most of the 2 stroke engines are now large stroke engines that produce more power. Hence they have high power to weight ration as compare to 4 stroke engine.

4.)Reliability:

Two stroke engines are more reliable in operation as compare to 4 stroke engine.

5.)Less Maintenance:

Due to absence of valve mechanism,the maintenance requirement of two stroke engine is much lesser than 4 stroke engine.

6.)No reduction attachments: 

As two stroke engines are low speed engine, there are no requirement of reduction gear or speed reduction arrangement as required for high speed four stroke engine.