- •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
IV. Give a short summary of Text 2
UNIT 3
I. Translate the text using a dictionary (in written form)
TEXT 3
Classification of Pumps
All pumps may be classified as either positive displacement or non-positive displacement. Most pumps used in hydraulic systems are positive displacement.
A non-positive displacement pump produces a continuous flow. However, because it does not provide a positive internal seal against slippage, its output varies considerably as pressure varies. Centrifugal and propeller pumps are examples of non-positive displacement pumps.
If the output port of non-displacement pump were blocked off, to stop flow, the pressure would rise and output would decrease. Although the pumping element would continue moving, slippage inside the pump would stop producing flow.
In a positive displacement pump, slippage is negligible compared to the pump’s volumetric flow. If the output port were plugged, pressure would increase instantaneously to the point that the pump’s pumping element or its case would break or the prime mover would stall.
UNIT 4
I. Write down the words and word combinations below into your exercise book.
1. trap задерживать
2. inlet входное отверстие
3. suction всасывание
4. gear шестерня, зубчатая передача
5. screw червяк, винт, резьба
6. lobe лопасть
7. vane пластина насоса, лопатка, лопасть
8. clearance расстояние
9. spur зубчатое колесо
10. helical косозубый, винтовой, спиральный
11. herringbone шевронный, косозубый
12. project проектировать
13. gear pump шестеренный насос
14. rotary pump роторный насос
II. Explain what the following international words from text 4 mean:
Erosion, type, result, method, classification, classify, electric motor, element, center,
III Read and translate Text 4 with a dictionary:
TEXT 4
ROTARY PUMPS
All rotary pumps have rotating parts which trap the fluid at the inlet (suction) port and force it through the discharge port into the system. Gears, screws, lobes,, and vanes are commonly used to move the fluid. Rotary pumps are positive displacement of the fixed displacement type. Rotary pumps are designed with very small clearances between rotating parts and stationary parts to minimize slippage from the discharge side back to the suction side. They are designed to operate at relatively moderate speeds. Operating at high speeds causes erosion and excessive wear which results in increased clearances. There are numerous types of rotary pumps and various methods of classification. They may be classified by the shaft position – either vertically or horizontally mounted; the type of drive – electric motor, gasoline engine, and so forth; their manufacture’s name or their service application. However, classification of rotary pumps is generally made according to the type of rotating element.
GEAR PUMPS
Gear pumps are classified as either external or internal gear pumps. In external gear pumps the teeth of both gears project outward from their centers. External pumps may use spur gears, herringbone gears, or helical gears to move the fluid. In an internal gear pump, the teeth of one gear project outward, but the teeth of the other gear project inward toward the center of the pump. Internal gear pumps may be either centered or off-centered.