STEERING SYSTEM.pptx theraml ppt automobile
- 2. The basic aim of steering is to ensure that the wheels are pointing in the desired directions to move the vehicle as required. This is typically achieved by a series of linkages, rods, pivots and gears. The steering system converts the rotation of the steering wheel into a swiveling movement of the road wheels in such a way that the steering wheel rim turns a long way to move the road wheels a short way. AIM OF STEERING SYSTEM
- 3. FUNCTIONS OF A STEERING SYSTEM Following are the functions of a steering system: 1. The primary function of the steering system is to achieve angular motion of the front wheels to negotiate a turn. 2. To provide directional stability of the vehicle when going straight ahead. 3. To facilitate straight ahead recovery after completing a turn. 4. To minimise wear and tear of tyres. 5. To absorb a major part of the road shocks thereby preventing them to get transmitted to the hands of the driver. 6. To provide perfect rolling motion of the road wheels at all times.
- 4. Components Of A Steering System: The components of a steering system are listed below. They are: 1. Steering wheel: The steering wheel is the control wheel to steer a vehicle by the driver. It contains a traffic indicator switch, light switch, wiper switch, etc. 2. Steering column or shaft: The Steering column is fitted inside the hollow steering column. When the steering wheel is turned, the steering shaft will also be rotated. Due to this, the motion is transmitted to the steering box. 3. Steering gear: The steering gearbox contains the gears that transmit the driver’s steering inputs to the steering linkage that turns the wheels, and it multiplies the driver’s steering changes so that the front wheels move more than the steering wheel. 4. Drop arm or pitman arm: A “drop pitman arm” is used to correct the steering when a vehicle has a suspension lift. 5. Ball joints: The ball joints are spherical bearings that connect the control arms to the steering knuckles.
- 5. 6. Drag link: The drag link connects the pitman arm to the steering arm. The drag link converts the sweeping arc of the steering arm to linear motion in the plane of the other steering links. 7. Steering arm: The steering arm is an arm for transmitting the turning force from the steering gear to the drag link, especially of an automotive vehicle.The basic function of the steering system is to allow the driver to safely and precisely steer the vehicle. 8. Stub axle: Drag link transfers this movement to stub axle which rotates about kingpin. This turns the right wheel. 9. Left spindle and kingpin: The wheel and tire assembly attach to the hub or spindle of the knuckle where the tire/wheel rotates while being held in a stable plane of motion by the knuckle/suspension assembly 10. Left tie rod arm: The right- and left-side tie rods are connected to each other by a center link, which is also mounted to the Pitman’s arm on the steering gear and the idler arm on the passenger side of the vehicle.
- 7. WHEELALIGNMENT All wheels of a vehicle should be parallel to the the direction of motion when it is moving in a straight line. For front wheels to be parallel when the vehicle is moving, proper adjustment is also necessary for easy steering, sure handling, smooth operation & good type wear. There are some factors on which wheel alignment depends. • Caster:-Caster angle is the tilt of king pin centre line towards front of back from the vertical line.It is the angle between the vertical line and king pin centre line in the wheel plane when looked from side. The Kingpin axis or steering axis may be tilted forward or backward from the vertical line. This tilt is known as Caster.
- 8. • Camber:- Camber angle is the angle between the vertical line and centre line of the tyre when viewed from the front of the vehicle. Camber angle is positive when this is outward. Camber angle is negative when angle is inward. • King pin inclination: It is the angle between king pin centre line and vertical line when seen from the front of the vehicle. It is also called steering axle inclination.King pin inclination and caster are used to improve directional stability in cars.
- 9. • Toe in & Toe out: In automotive engineering, toe also known as tracking. This can be contrasted with steer, which is the anti symmetric angle, i.e. both wheels point to the left or right, in parallel (roughly). Positive toe, or toe in, is the front of the wheel pointing in towards the centerline of the vehicle .Negative toe, or toe out, is the front of the wheel pointing away from the centerline of the vehicle.
- 10. TYPES OF STEERING SYSTEM
- 11. • Rack and Pinion Steering Gear In the rack and pinion steering gear, a pinion is mounted on the end of the steering shaft. It engages with the rack which has a ball joint at each end to allow for the rise and fall of the wheels. The roads connect the ball joints to the stub excels. The rotary movement of the steering wheel turns the pinion which moves the rack sideways. This movement of the rack is converted into wheels.
- 12. • Worm and wheel steering gear Worm wheel is carried in bearings in a cast iron case. Worm wheel is connected to a drop arm. The worm which is keyed on to steering shaft meshes with the worm wheel. Steering wheel is mounted at the upper end of the steering shaft. When driver rotates the steering wheel, drop arm moves in backward or forward direction. This results in motion of the stub axles.
- 13. • Hydraulic power steering system- It is the type of power steering system in which hydraulic system having hydraulic pump driven by the engine and hydraulic cylinders, is used to multiply the steering wheel input force which in turn reduces the efforts required to steer the front wheels of the vehicle.A highly compressed hydraulic fluid is used inside the hydraulic cylinder that applies pressure on the steering gear.
- 14. • Electronic power steering system It is the latest type of power steering system in which the hydraulic system from the hydraulic power steering is completely replaced with electric motors and electric sensors, instead of using hydraulic force ,the motor driven by the vehicle’s battery is used to apply force on the steering gear and torque provided by the motor is controlled by the sensors that detects the position of the steering column.
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