Automotive - How to know Steering Ratio.pptx

The presentation explains about how to compute the steering ratio in automotive.

1. WHAT IS A STEERING SYSTEM?

2. The S teering S ystem is a mechanism that allows a driver to control the direction of a vehicle . The steering system converts the rotation of the steering wheel into a swivelling movement of the road wheels, and enables the driver to steer the vehicle with light forces.

3. STEERING RATIO

4. One purpose of the steering mechanism is to provide mechanical advantage. In a machine or mechanical device, it is the ratio of the output force to the input force applied to it.

5. A steering wheel ratio is the number of degrees that your steering wheel will turn when the car turns one degree. It is a number of degrees that the steering wheel must be turned to pivot the front wheels 1 degree.

6. Steering ratios vary, depending on the type of vehicle and its intended use. High steering ratio are often called slow steering because the steering wheel has to be turned many degrees to produce a small steering effect. Low steering ratios , called fast o quick steering , require much less steering wheel movement to produce the desired steering effect.

7. Steering Ratio is determined by 2 factors: the Steering-Linkage Ratio and the Gear Ratio in the steering mechanism. The relative length of the pitman arm and the steering arm determines the steering-linkage ratio. The steering arm is bolted to the steering spindle at one end and connected to the steering linkage at the other.

8. When the effective lengths of the pitman arm and the steering arm are equal, the linkage has a ratio of 1:1. If the pitman arm is shorter or longer than the steering arm, the ratio is less than or more than 1:1.

9. Most of the steering ratio is developed in the steering mechanism. The ratio is due to the angle or pitch of the teeth on the worm gear to the angle or pitch on the sector gear. Steering ratio is also determined somewhat by the effective length and shape of the teeth on the sector gear.

10. In the rack-and-pinion steering system , the steering ratio determined largely by the diameter of the pinion gear. The smaller the pinion, the higher the steering ratio. However, there is a limit to how small the pinion can be.