Power Steering System

Presented By:Chintan PandyaSKSITS, Indore.

Power Steering System

Mechanical Engineering Project

Content

• Introduction• History• Definition• Components in Power Steering• Types of Power Steering• Advantages over the manual Steering• Advantages & Disadvantages• Conclusion

Introduction• Steering: The act of Guiding or Showing the way

• Steering Mechanism: A mechanism by which something is

steered.(Especially motor vehicle)

• Primary Function of the steering system is to achieve angular

motion of the front wheels to negotiate a turn.

• This is done through linkage and steering gear which convert

the rotary motion of the steering wheel into angular motion of

the front road wheels.

• Secondary Function of steering system are:1. To provide directional stability of the vehicle

when going straight ahead.2. To provide perfect steering condition3. To facilitate straight ahead recovery after

completing a turn.4. To minimize tyre wear.

Cont..

First installed in 1876. On April 1900, Robert Twyfrod from USA got the

patent for the first four wheel drive system. In 1926 demonstrated the first PSS. On agricultural tractors in the early 1950’s.

Suitable for small to medium tractors where

power steering can be an option to manual steering.

History

Definition• Power Steering: Power assisted steering.• Power Steering is a system for steering which

uses power from the engine so that it is easier for the driver to steer the vehicle.

• Power steering system in the vehicle enables the driver to steer the wheels with some source of power other than the drivers manual force .

• Reservoir• Steering gear box• Rotary valve• Pump

Components in power steering

Reservoir

Rotary Valve

• A rotary valve for a power steering system includes a valve sleeve in which a rotor is rotatably carried for controlling fluid flow from a supply pump to a cylinder of the power steering system.

Pump

• Driven by vehicle’s engine.• Amount of flow depends on engine’s speed.

Steering Gear Box

• Steering gears are enclosed in a casing known as steering gear box

Types of Power Steering1. Hydraulic Power Steering:

• Most power steering systems work by using a hydraulic system to steer the vehicle's wheels. The hydraulic pressure typically comes from a generator or rotary vane pump driven by the vehicle's engine.

• Since the hydraulic pumps are positive-displacement type, the flow rate they deliver is directly proportional to the speed of the engine.

Hydraulic Power Steering(HPS)

1. Hydraulic Control Valve

2. Pinion Gear 3. Hydraulic

Pressure/Return Lines

4. Hydraulic Piston5. Rack Housing

Cont…

2. Electric Power Steering:• To provide steering assistance, an

electric motor mounted to the side of the rack housing drives a ball-screw mechanism via a toothed rubber belt. The screw engages a spiral cut in the outside of the steering rack. A torque sensor attached to the pinion shaft signals a control computer when to provide assistance.

Electric Power Steering(EPS)1. Pinion Shaft 2. Steering Torque

Sensor 3. Rack-and-Pinion

Housing 4. Electric Motor5. Ball-screw

Mechanism 6. Steering Rack 7. Drive Belt

HPS V/S EPS

• Hydraulic Power Steering System is complicated compared with Electric Power Steering.

• Hydraulic Power Steering uses hydraulic fluids for operation whereas there is no such fluid needed for Electric Power Steering, thus Electric Power Steering needs less maintenance compared to hydraulic power steering.

• Electric Power Steering gives better response at different speeds as compared to Hydraulic Power Steering

• Hydraulic power steering extracts power from engine, so it reduces the fuel mileage of the engine. Electric power steering consumes power from battery which is also charged by engine, but it consumes less power compared to Hydraulic power steering. So a car having Electric power steering will give more mileage than one with Hydraulic power steering

Advantages over the manual Steering• The steering effort is reduced.• The vehicle can be steered lock to lock with

approximately one & half steering wheel turns on either side compare to more than 3 turns on either side in case of manual gear.

• The power steering system absorbs the road shocks.

• The power steering leads to greater safety because such deviation from the course of the vehicle whatever minor course-correction are required can be made quickly & effortlessly.

Advantages

Preventing the wheels from transferring the load to the steering column Reducing the driver’s fatigueLow input torque and continuous steering function Oil output directly proportional to the steering speed

Disadvantages

Design is complications and increased in cost.

Fluid leakage.

Conclusion

• By studying all these we can conclude that the power steering is necessary for the modern cars.

• Now a days we can see almost all cars having a power steering.

• It provides good handling to the driver, gives better comfort, and make him less fatigue.

Thank You

Presented by Faadooengineers