9. Translate the following words and word combinations into Ukrainian:

pneumatic motor, potential energy, compressed air, mechanical work, linear or rotary motion, piston actuator, hand-held tool industry, continual attempts, transportation industry, to overcome efficiency deficiencies, viable option, piston, chamber, shaft, spring, force, rotation speeds, windmill, ratchet wrenches, drills, sanders, grinders, cutters, advantage.

10. Imagine that you are a research worker and you have to make a report about pneumatic motors. Read the text once more and give subtitles to each paragraph of the text in order to use them as the base for your report.

LESSON 3

1. Read and learn the following words:

equipment обладнання

pipe труба

piston поршень

ratio передатне число

agility швидкість

multiplication збільшення

compression стиснення

torque обертальний момент

leverage піднімальна сила

load навантаження

welding зварювання

2. Read and translate the text: Hydraulic System

The history of hydraulic systems takes us into the world of technology and construction. This is one of those innovative methods of making work easier and more efficient by compressing fluids that are locked inside a channel or compartment. This compression is an applied force or torque and supplies leverage to a workload. Thus the work load is lessened or made easier. The power steering in cars is a good example of the use of hydraulic systems. There are countless other hydraulic systems that have come about since the first use of such systems were invented.

From backyard log splitters to the huge machines you see on construction sites, hydraulic equipment is amazing in its strength and agility. On any construction site you see hydraulically-operated machinery in the form of bulldozers, backhoes, shovels, loaders and cranes. Hydraulics operate the control surfaces on any large airplane. You see hydraulics at car service centers lifting the cars so that mechanics can work underneath them, and many elevators are hydraulically-operated using the same technique. Even the brakes in your car use hydraulics.

A simple hydraulic system consists of two pistons and an oil-filled pipe connecting them.

The basic idea behind any hydraulic system is very simple: force that is applied at one point is transmitted to another point using an incompressible fluid. The fluid is almost always an oil of some sort. The force is almost always multiplied in the process.

For example, two pistons fit into two glass cylinders filled with oil and connected to one another with an oil-filled pipe. If you apply a downward force to one piston, then the force is transmitted to the second piston through the oil in the pipe. Since oil is incompressible, the efficiency is very good, almost all of the applied force appears at the second piston.

A fundamental feature of hydraulic systems is the ability to apply force or torque multiplication in an easy way, independent of the distance between the input and output, without the need for mechanical gears or levers, either by altering the effective areas in two connected cylinders or the effective displacement between a pump and motor. In normal case hydraulic ratio is combined with a mechanical force or torque ratio for optimum machine designs, like in boom movements and track drives for an excavator.

The great thing about hydraulic systems is that the pipe connecting the two cylinders can be any length and shape, allowing it to snake through all sorts of things separating the two pistons. The pipes are used in case standard hydraulic tubes are not available. Generally hydraulic pipes are used for low pressure. They can be connected by threaded connections, but usually by welds. Because of the larger diameters the pipe can usually be inspected internally after welding. Black pipe is non-galvanized and suitable for welding. The pipe can also fork, so that one master cylinder can drive more than one slave cylinder if desired.

The neat thing about hydraulic systems is that it is very easy to add force multiplication or division to the system. If you have read How a Block and Tackle Works or How Gears Work, then you know that trading force for distance is very common in mechanical systems. In a hydraulic system, all you do is change the size of one piston and cylinder relative to the other.

It is important that a hydraulic system contains no air bubbles. You may have heard about the need to "bleed the air out of the brake lines" of you car. If there is an air bubble in the system, then the force applied to the first piston gets used compressing the air in the bubble rather than moving the second piston, which has a big effect on the efficiency of the system.