Construction and Working of a Differential in Automobile

July 15, 2015

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- modern type of differential
Construction of Limited Slip Differential

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 –

  1. Fixed value
  2. Torque sensitive
  3. Speed sensitive &
  4. Electronically controlled

Suggested article for auto enthusiasts –

What is clutch? Why do we need it? Working and types with animation !

All types of Brakes animation used in automobile !

Cubli – A robot which jumps, balances and walks on his own !

July 14, 2015

Cubli :-

A combination of two words, Cube – an English word & li- an Swiss German diminutive word meaning ”small”. Researchers from the ETH Zurich’s Institute for Dynamic Systems and Control have developed the Cubli, a 15x15x15 cm device that can walk, jump, and balance itself on its edge or even on a corner.

Cubli the walking robot

Researchers said that balancing was not a big issue for The Cubli, while the problem was jumping up from the rest position because at that instant, it needed more energy so they used reaction wheels mounted on three faces of the cube which rotated at high angular velocities & then brake suddenly which caused cubli to jump.

Once the cube stood up on a corner, controlled motor torques were applied to balance on one point.
In addition to balancing, motor torques were also used for a controlled fall in any direction.
Combining these things – jumping up, balancing, and controlled falling — the Cubli is able to walk on its own !


How do trains turn without differential ?

July 14, 2015

We have traveled thousands of kilometers in trains, but we haven’t given a thought about how do trains turn during a curved path ? Both the wheels are connected through an axle & obviously are of same diameter. But,when a train takes turn, the outer wheel has to cover more distance than the inner one…! How is this possible ? How can the outer wheel cover more distance than the inner one even when both the wheels have same diameter ??? 🙁

more “How do trains turn without differential ?”

Hello World !

July 14, 2015

Hi there everyone… My name is Jay Baviskar & this my website & my first post.