Steering

Power steering gear was developed to solve the steadily increasing steering problems. Power steering was first applied to heavy trucks and military vehicles early in the 1930s, and hundreds of patents were granted for devices to help the driver turn the steering wheel. Most of the proposed devices were hydraulic; some were electrical and some mechanical. A pump driven by the engine maintains the hydraulic fluid under pressure. A valve with a sensing device allows the fluid to enter and leave the power cylinder as necessary. Speed-sensitive variable effective ratio systems are available on a few cars to provide reduced steering effort for low-speed maneuvers and more sensitive lower ratios for high-speed highway steering.

Communication with the hydraulic cylinder goes through a two-way restrictor valve. This valve limits the rate of movement of the plunger in the cylinder, since fluid must be pushed into the sphere when the body descends and returned when it rises. This damping action thus controls the motion of the wheel with respect to the sprung portion of the vehicle supported by the spring.

So-called “active suspensions” incorporate a microprocessor to vary the orifice size of the restrictor valve in a hydraulic suspension or shock absorber. This changes the effective spring rate. Control inputs may be vehicle speed, load, acceleration, lateral force, or a driver preference.

II. Look through the text again and answer the following questions:

1. What was power steering gear developed for?

2. When was power steering applied for the first time?

3. What does a valve with a sensing device allow to do?

4. What does the damping action control?

5. What did you understand as”steering”?

III. Match the words with their definitions and make up your own sentences with these words:

1. gear	a) a machine for forcing liquid into, out of, through smth.;
2. pump	b) a set of wheels with teeth on their edges that revolve together to transmit power;
3. wheel	c) an increase in the rate or speed of smth.;
4. valve	d) a part of device that can be pushed down;
5. plunger	e) a mechanical device for controlling the flow of air, liquid allowing it to move in one direction;
6. spring	f) a circular object that turns around rod at its center;
7. suspension	g) a device of twisted metal or wire that can be pushed but returns to its original shape;
8. acceleration	h) the system of springs by which a vehicle is supported on its wheel;
9. steering wheel	i) the quality of being quick or rapid;
10. speed	j) a mechanism for steering a car;

IV. Find the information about new steering wheel performance. While looking for information you are free to use the internet sites given below as well as any other online resources. Make a short presentation in front of the class.

Resources recommended:

www.automobile.com

www.wikeipedia.com

www.euromotocars.com

www.autoreview.ru

<== попередня сторінка	\|	наступна сторінка ==>
IV. Find the information about new brake performance. While looking for information you are free to use the internet sites given below as well as any other online resources.	\|	Text 20

Не знайшли потрібну інформацію? Скористайтесь пошуком google:

Генерація сторінки за: 0.006 сек.