GEAR BOX!


How Manual Transmissions Work



A manual transmission, also known as a manual gearbox or standard transmission (informally, a manual, 5 speed, or the number of forward gears said with the word speed following i.e.: 4 speed with overdrive, 4 speed, 5 speed, 6 speed or standard, stick-shift, straight shift, straight, or straight drive (U.S.)) is a type of transmission used in motor vehicle applications. It generally uses a driver-operated clutch, typically operated by a foot pedal (automobile) or hand lever (motorcycle), for regulating torque transfer from the internal combustion engine to the transmission; and a gear stick, either operated by foot (as in a motorcycle) or by hand (as on an automobile).

CLUTCH


A clutch is a mechanical device that provides for the transmission of power (and therefore usually motion) from one component (the driving member) to another (the driven member) when engaged, but can be disengaged.
Clutches are used whenever the transmission of power or motion needs to be controlled either in amount or over time (e.g., electric screwdrivers limit how much torque is transmitted through use of a clutch; clutches control whether automobiles transmit engine power to the wheels).
In the simplest application, clutches are employed in devices which have two rotating shafts (drive shaft or line shaft). In these devices, one shaft is typically attached to a motor or other power unit (the driving member) while the other shaft (the driven member) provides output power for work to be done.


GEAR



A gear is a rotating machine part having cut teeth, or cogs, which mesh with another toothed part in order to transmit torque. Two or more gears working in tandem are called a transmission and can produce a mechanical advantage through a gear ratio and thus may be considered a simple machine. Geared devices can change the speed, torque, and direction of a power source. The most common situation is for a gear to mesh with another gear, however a gear can also mesh a non-rotating toothed part, called a rack, thereby producing translation instead of rotation.
The gears in a transmission are analogous to the wheels in a pulley. An advantage of gears is that the teeth of a gear prevent slipping.

When two gears of unequal number of teeth are combined a mechanical advantage is produced, with both the rotational speeds and the torques of the two gears differing in a simple relationship.
In transmissions which offer multiple gear ratios, such as bicycles and cars, the term gear, as in first gear, refers to a gear ratio rather than an actual physical gear. The term is used to describe similar devices even when gear ratio is continuous rather than discrete, or when the device does not actually contain any gears, as in a continuously variable transmission.

If you have ever driven a car with an automatic transmission, then you know that there are two big differences between an automatic transmission and a manu­al transmission:

There is no clutch pedal in an automatic transmission car.
There is no gear shift in an automatic transmission car. Once you put the transmission into drive, everything else is automatic.


It all starts in a place between the engine and the transmission with a component called torque converter, a large fluid turbine clutch, hidden inside the bell housing-the front part of the transmission bolted to the engine. The converter is actually a pump and turbine mechanism assembled together with a series of huge vain passages designed to create a strong centrifugal force using the oil going through them.

Once you start the engine, the torque converter begins to rotate at engine speed and waits for you to shift gears. When you go from Park to Drive, the converter turbine uses a shaft to engage a series of gear sets located inside their own drum cases. These gear sets are called planetary gearsets because their varied size gears mesh together in a planetary system-like configuration to rotate and provide different torque speeds.

The key characteristic of a torque converter is its ability to multiply torque when there is a substantial difference between input and output rotational speed, thus providing the equivalent of a reduction gear. Some of these devices are also equipped with a temporary locking mechanism which rigidly binds the engine to the transmission when their speeds are nearly equal, to avoid slippage and a resulting loss of efficiency.



BASIC PRINCIPLE 

- A vehicle has a transmission to have the ability to apply different RPMs to different driving speed rangers, This is done by having a number of different gears which each feature different gear ratios.Different gear ratios are needed for when the vehicle needs more power or speed as the road conditions change.