Suspension and steering systems!






A spring is an elastic object used to store mechanical energy. Springs are usually made out of spring steel. Small springs can be wound from pre-hardened stock, while larger ones are made from annealed steel and hardened after fabrication.When a spring is compressed or stretched, the force it exerts is proportional to its change in length. The rate or spring constant of a spring is the change in the force it exerts, divided by the change in deflection of the spring.

Suspension systems serve a dual purpose — contributing to the vehicle's roadholding/handling and braking for good active safety and driving pleasure, and keeping vehicle occupants comfortable and reasonably well isolated from road noise, bumps, and vibrations,etc. These goals are generally at odds, so the tuning of suspensions involves finding the right compromise. It is important for the suspension to keep the road wheel in contact with the road surface as much as possible, because all the forces acting on the vehicle do so through the contact patches of the tires.




A shock absorber is a mechanical device designed to smooth out or damp shock impulse, and dissipate kinetic energy. It is a type of dashpot.Shock absorbers are an important part of automobile and motorcycle suspensions, aircraft landing gear, and the supports for many industrial machines. Large shock absorbers have also been used in structural engineering to reduce the susceptibility of structures to earthquake damage and resonance.


What is a shock absorber?

A shock absorber is a suspension component that controls the up-and-down motion of the vehicle’s wheels.

Though the devices are called shock absorbers, the job of absorbing the jolts that result when the wheels pass over bumps or dips is handled mostly by the springs. Shock absorbers would more accurately be named dampers, as they are called in the United Kingdom. Their main job is to damp the motion mentioned above, keeping the vehicle’s body from bouncing down the road on its springs. In fact, the simplest shock absorber test is to push down on the vehicle’s bumper; a healthy shock absorber or MacPherson strut will allow the body to rebound but quickly come to rest. If the vehicle goes into a prolonged bounce cycle, the shock needs to be replaced. Bad shocks or struts aren’t safe because they fail to maximize tire contact with the road, which degrades handling and braking.


Power Steering Pump


Power steering helps drivers steer vehicles by augmenting steering effort of the steering wheel. Hydraulic or electric actuators add controlled energy to the steering mechanism, so the driver needs to provide only modest effort regardless of conditions. Power steering helps considerably when a vehicle is stopped or moving slowly. Also, power steering provides some feedback of forces acting on the front wheels to give an ongoing sense of how the wheels are interacting with the road; this is typically called "rοad feel".
Representative power steering systems for cars augment steering effort via an actuator, a hydraulic cylinder, which is part of a servo system. These systems have a direct mechanical connection between the steering wheel and the linkage that steers the wheels. This means that power-steering system failure (to augment effort) still permits the vehicle to be steered using manual effort alone.






Steering Rack 



Rack-and-pinion steering is quickly becoming the most common type of steering on cars, small trucks and SUVs. It is actually a pretty simple mechanism. A rack-and-pinion gearset is enclosed in a metal tube, with each end of the rack protruding from the tube. A rod, called a tie rod, connects to each end of the rack.
The pinion gear is attached to the steering shaft. When you turn the steering wheel, the gear spins, moving the rack. The tie rod at each end of the rack connects to the steering arm on the spindle.




Part of the rack contains a cylinder with a piston in the middle. The piston is connected to the rack. There are two fluid ports, one on either side of the piston. Supplying higher-pressure fluid to one side of the piston forces the piston to move, which in turn moves the rack, providing the power assist.


What Is A Tie Rod?

The tie rod is part of the steering mechanism in a vehicle. A tie rod is a slender structural rod that is used as a tie and capable of carrying tensile loads only.

A tie rod consists of an inner and an outer end. The spokes on a bicycle’s wheels are tie rods. As the ratio of its length to the radius of gyration of its cross section is normally quite large, it would likely buckle under the action of compressive forces.

The tie rod transmits force from the steering center link or the rack gear to the steering knuckle. This will cause the wheel to turn. The outer tie rod end connects with an adjusting sleeve, which allows the length of the tie rod to be adjustable. This adjustment is used to set a vehicle’s alignment angle.

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.