- •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. Answer the following questions to the text:
What does the spur gear pump consist of?
What do the inlet port and outlet port connected to?
When is the liquid pushed into the outlet port?
What is the difference between the herringbone gear pump and spur gear pump?
IV. Give a short summary of Text 5
UNIT 6
I. Write down the words and word combinations below into your exercise book.
1. smooth плавный, ровный, выравнивать
2. sacrifice уменьшаться, ухудшаться
3. timing gear зубчатое колесо, распределительная
шестерня
4. roller bearing подшипник качения
5. alignment выравнивание, установка по прямой
6. prevent предотвращать
7. chamber камера
8.crescent серповидный распределительный
элемент
9. tolerance допуск, допустимый предел
II. Read and translate the following words and word combinations:
Alignment, crescent, sacrifice, roller bearing, helical gear pump, sacrifice, smoothness, slippage, crescent-shaped
III. Read and translate Text6 with a dictionary:
TEXT 6
HELICAL GEAR PUMP
The helical gear pump is still another modification of the spur gear pump. Because of the helical gear design, the overlapping of successive discharges from spaces between the teeth is even greater than it is in the herringbone gear pump; therefore, the discharge flow is smoother. Since the discharge flow is smooth in the helical pump, the gears can be designed with a small number of large teeth – thus allowing increased capacity without sacrificing smoothness of flow. The pumping gears of this type are driven by a set of timing and driving gears that help maintain the required close clearances without actual metallic contact of the pumping gears. Metallic contact between the teeth of the pumping gears would provide a tighter seal against slippage; however, it would cause rapid wear of the teeth, because foreign matter in the liquid would be present on the contact surfaces. Roller bearings at both ends of the gear shafts maintain proper alignment and minimize the friction loss in the transmission of power. Suitable packings are used to prevent leakage around the shaft.
OFF-CENERED INTERNAL GEAR PUMP
The drive gear is attached directly to the drive shaft of the pump and is placed off-center in relation to the internal gear. The two gear mesh on one side of the pump, between the suction (inlet) and discharge ports. On the opposite side of the chamber, a crescent-shaped form fitted to a close tolerance fills the space between the two gears. The rotation of the center gear by the drive shaft causes the outside gear to rotate, since the two are meshed. Everything in the chamber rotates except the crescent. This causes liquid to be trapped in the gear spaces as they pass the crescent. The liquid is carried from the suction port to the discharge port where it is forced out of the pump by the meshing of the gears. The size of the crescent that separates the internal and external gears determines the volume delivery of the pump. A small crescent allows more volume of liquid per revolution than a larger crescent.