Earlier in the Engines section we saw how 4 stroke & 2 stroke engines work ! We might like to give a thought on which is better one OR which has more advantages. So in this article we are going to discuss about the differences, advantages & disadvantages of 4 stroke & 2 stroke engine. more “Differences, Advantages & Disadvantages of 4 stroke vs 2 stroke engine”
Human started with just wheels for travelling & transportation purposes at first. Then came bikes, cars & trains which could be driven on land. The next difficulty was to overcome the vast oceans & seas which led to invention of ships. Engineers are still finding ways to make today’s vehicles more better & efficient even though we have achieved success in almost every mode of travelling & transportation. One of the extraordinary machine in history of vehicles is hovercraft. Lets see how does a hovercraft work ? more “How does a hovercraft work ? | Design & Application”
In my previous article, we learned how 4 stroke engines work ! This time we will learn about the second type of engine i.e 2 stroke engine. The 2 stroke engine is a type of Internal combustion engine where one power cycle is completed with two strokes of the piston during only one rotation of crankshaft. The first commercial two-stroke engine involving in-cylinder compression is attributed to Scottish engineer Dugald Clerk.
The 2 stroke engine performs all the same steps which are performed by 4 stroke engine – suction, compression, expansion & exhaust; but the 2 stroke engine performs these all steps in only 2 stroke unlike the 4 stroke engine which completes one power cycle in 4 strokes. more “How does a 2 stroke engine work ?”
These are the most basic engines used in cars & bikes i.e Four stroke cycle petrol engine OR 4 stroke engine(often called). It is very easy to understand until & unless you wanna do all the thermodynamic calculations & all that stuff ! more “How does a 4 stroke engine work ?”
What is submarine & why do we need it ?
Imagine you are on-board a ship & what would be the worst thing that would happen to you ? – the water flooding inside the ship making it sink to the seabed…damn…! So we need something which ensures either it doesn’t sink OR even after sinking, all be safe.
So in simple words – a Submarine is a vehicle which allows us to travel on water as well as deep inside the seas & oceans.
Also a submarine is used in military for protection purposes. more “How does a submarine work ?”
Thinking to walk on water ? – really bad idea. Why cant we walk on water ? Why does not everything float ? Why doesn’t a stone or any other thing float even if they are are very small ? & HOW DO SHIPS FLOAT BEING SO HEAVY ? more “How do ships float ?”
In my previous article we saw about how trains turn on curved tracks. Well in automobiles, we can’t use the same principle for turning around a corner as our cars don’t run on tracks. So we cannot design our tires as the train wheels. At the beginning of auto industry, only one rear wheel was driven by the engine. But if only one wheel was driven by the engine, it had to all the work & also it couldn’t maintain a good grip on the road.
So if we drive or supply power to both the wheels, the outer wheel had to cover more distance than the inner one while taking a turn. This is why we need differential – to drive both the wheels at different speeds!
Construction of differential :-
The standard differential mainly consists of 3 parts –
1. The pinion gear
2. The ring gear &
3. The spider gear
The pinion gear transfers the power from engine to the ring gear.The spider gear lies at the inner edge of the ring gear.The spider gear is free to rotate on 2 axes-
1. along with the rotation of ring gear &
2. on its own axis(spin)
Also the spider gear is connected to two more side gears.
Working of Differential :-
So, first the power is transferred from engine’s drive shaft to pinion gear, since the pinion gear & ring gear are meshed, power flows to ring gear.As the spider gear is connected with the ring gear, power flows to it. Finally from the spider gear, power gets transferred to both the side gears.
–When the vehicle moves straight, the spider gear doesn’t spin & will make BOTH the side gears rotate at same speed.
–When the vehicle moves on a curve road, the spider gear itself spins & either of the side gears move slower or faster than other one.Which will be faster & which will be slower is decided by the turn.
Make sure you watch the video. I assure you a 100% guarantee of understanding the whole thing.
Here is a demonstration in the most simplest way ever possible…!
you can jump to 1:56 if you want to skip the boring part.
Limited Slip Differential –
Limited Slip Differentials or LSDs are the most modern and complicated type differentials used today in automobiles.
The biggest disadvantage of ordinary differential is when a slip condition occurs only on one wheel. The differential transmits all the power to the one which has the least resistance. This wastes too much power. Along with that, it doesn’t help the car get out of the slip condition. This is where LSDs come into action.
Limited slip differential limits the amount of torque or power transmission on one wheel and transmits it to the other wheel. This is done via adding a pre-loaded spring or clutch packs.
Types of Limited slip differentials –
- Fixed value
- Torque sensitive
- Speed sensitive &
- Electronically controlled
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