- •Введение
- •I. Write down the words and word combinations below into your exercise-book. Memorize them.
- •Explain what the following international words from Text 1 mean:
- •Read Text 1 and answer the following questions:
- •Find in the text the sentences with Passive Voice and translate them: text 1
- •V. Give a short summary of Text 1 unit 2
- •I. Write down the words and word combinations below into your exercise book. Memorize them.
- •II. Explain what the following international words from text 2 mean:
- •Read Text 1 and answer the following questions:
- •IV. Give a short summary of Text 2
- •I. Translate the text using a dictionary (in written form)
- •I. Write down the words and word combinations below into your exercise book.
- •II. Explain what the following international words from text 4 mean:
- •III Read and translate Text 4 with a dictionary:
- •IV. Answer the following questions to the text:
- •Give a short summary of Text 4
- •1.Write down the words and word combinations below into your exercise book.
- •II. Pronounce the following words: (Прочтите следующие слова)
- •Read and translate Text 5 with a dictionary:
- •IV. Answer the following questions to the text:
- •IV. Give a short summary of Text 5
- •I. Write down the words and word combinations below into your exercise book.
- •II. Read and translate the following words and word combinations:
- •III. Read and translate Text6 with a dictionary:
- •IV. Answer the following questions to the text:
- •Give a short summary of Text 6
- •1.Translate the text with a dictionary in written form
- •I. Write down the words and word combinations below into your exercise book.
- •II. Read and translate Text 8 with a dictionary
- •III. Answer the following questions to the text:
- •IV. Give a short summary of Text 8
- •I. Write down the words and word combinations below into your exercise book.
- •II. Read and translate Text 9 with a dictionary:
- •Vane pump
- •III. Answer the following questions to the text:
- •Give a short summary of Text 9
- •1. Write down the words and word combinations below into your exercise book.
- •II. Read and translate text 10 with a dictionary:
- •1. Write down the words and word combinations below into your exercise book.
- •2. Give a short summary of Text 12 without a dictionary
- •Содержание
III. Answer the following questions to the text:
Where are screw pumps generally used?
How do screw pumps operate?
What provides a protective film to prevent metal-to metal contact?
What is effective performance based on?
IV. Give a short summary of Text 8
UNIT 9
I. Write down the words and word combinations below into your exercise book.
1. cavity полость, углубление, канал
2. slot паз, прорезь
3. vane лопасть, пластина ротационного насоса
4. enlarge увеличивать(ся),
5. noise шум
6. stroke ход, такт
7. vane pump лопастной насос
8. reciprocating pump насос с возвратно-поступательным
движением, плунжерный насос
II. Read and translate Text 9 with a dictionary:
TEXT 9
Vane pump
Vane-type hydraulic pumps generally have circularly or elliptically shaped interior and flat end plates. A slotted rotor is fixed to a shaft that enters the housing cavity through one of the end plates. A number of small rectangular plates or vanes are set into the slots of the rotor. As the rotor turns, centrifugal force causes the outer edge of each vane to slide along the surface of the housing cavity as the vanes slide in and out of the rotor slots. The numerous cavities, formed by the vanes, the end plates, the housing, and the rotor enlarge and shrink as the rotor and vane assembly rotates. An inlet port is installed in the housing so fluid may flow into the cavities as they enlarge. An outlet port is provided to allow the fluid to flow out of the cavities as they become small. The pump shown in figure 4-9 is referred to as an unbalanced pump because all of the pumping action takes place on one side of the rotor. This causes a slide load on the rotor. Some vane pumps are constructed with an elliptically shaped housing that forms two separate pumping areas on opposite sides of the rotor. This cancels out the side loads; such pumps are referred to as balanced vane. Usually vane pumps are fixed displacement and pump only in one direction. There are, however, some designs of vane pumps that provide variable flow. Vane pumps are generally restricted to service where pressure demand does not exceed 2000 psi. Wear rates, vibration, and noise levels increase rapidly in vane pumps as pressure demands exceed 2000 psi.
RECIPROCATING PUMPS
The term reciprocating is defined as back-and-forth motion. In the reciprocating pump it is this back-and-forth motion of pistons inside of cylinders that provides the flow of fluid. Reciprocating pumps, like rotary pumps, operate on the positive principle – that is, each stroke delivers a definite volume of liquid to the system. The master cylinder of the automobile brake system is an example of a simple reciprocating pump. Several types of power-operated hydraulic pumps, such as the radial piston and axial piston, are also classified as reciprocating pumps. These pumps are sometimes classified as rotary pumps, because a rotary motion is imparted to the pumps by the source of power. However, the actual pumping is performed by sets of pistons reciprocating inside sets of cylinders.