Purpose of Steering System
The travel of a vehicle is controlled by the steering system, which comprises of linkages that connect steering wheel to the wheels and tires. Types of steering system are manual and power steering. In manual steering system, the only source of energy is the force applied by the driver. In power steering system, hydraulic pump or electric motor is used to assist the effort of the driver, to control movement of the vehicle. Modern vehicles, especially heavy vehicles, have power steering systems to control the vehicle with ease.
Operation of Steering System
The fundamental system of operation is the same in manual and power steering systems. As the steering wheel is turned by the driver, the movement is carried to the steering gear, which changes the rotary motion of the steering wheel into straight or linear motion. The linear motion is transmitted through steering linkages or tie rods, attached to the knuckle arms or steering arms. The steering knuckles, then pivot inward or outward on ball joints, which moves the wheels and tires to the left or right, as desired by the driver.
Components of Manual Steering System
The manual steering system consists of the steering wheel and steering shaft that transmit the effort of the driver to the steering gear. The steering gear increases the mechanical advantage, while changing the rotary motion of the steering wheel to linear motion. Tie rod ends connect balls with steering arms, which fit into ball sockets
Types of Steering Gears
Types of steering gears used in auto motive vehicles are the recirculation ball steering gear, and the rack-and-pinion steering gear. Both the steering gears are used in manual and power steering systems. Some vehicles use a worn-and-roller steering gear, which is similar to the recirculation ball system.
In steering system, the driver applies a small input force at the steering wheel, which produces a larger output force at the wheels. This increase in force is due to the mechanical advantage or steering ratio of the steering gear. Mechanical advantage is known as the ratio of force at output to the force at input. Steering ratio is the number of degrees that the steering wheel must turn so as to pivot the front wheels by one degree
Components Power Steering System
Power steering systems are basically a manual steering system with a power boosted. Some automotive power steering systems are operated hydraulically with a pump that supplies high pressure fluid, when the driver turns the steering wheel. Pressurized fluid causes the piston to move and provide most of the steering effort. This provides most of the required steering effort. Some cars also have electric power steering in which an electric motor provides the additional power.