FAQ

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Q What is the self-sucking pump and what is its working principle?

A For normal centrifugal pump, if the suction surface is below the impeller, it needs to fill water when starting the pump, which is very inconvenient. In order to store water in the pump, bottom valve is installed at the inlet of suction pipe, and when the pump works, bottom valve will lead to great hydraulic loss. But for the so-called self-sucking pump, it does not need to fill water when starting the pump (it still needs to fill water for the first starting after installation), and after short-time running, the pump can suck water and can be put into normal use.
Q Interpretation of relevant terms of the engine

A
Dead center: piston is connected with crank and rod assembly. The piston has top and bottom limit positions in the cylinder. The top limit position is called top dead center, which is the farthest from the crankshaft centerline. The bottom limit position is called bottom dead center, which is the nearest to the crankshaft centerline.

Piston stroke: The distance of piston movement from top dead center to bottom dead center is called stroke. Cylinder working capacity: piston swept volume in the cylinder when piston moves for a stroke.

Working volume of combustion chamber: the room that is between the piston top and the top of the central combustion chamber of the cylinder head when the piston is at top dead center

Total cylinder volume: the sum of cylinder working volume and working volume of combustion chamber

Compression ratio: an important structural parameter of the engine, which directly influence the power of the engine

Compression ratio（ε）= Total cylinder volume/ working volume of the combustion chamber= 1+ cylinder working volume/ working volume of the combustion chamber

In general conditions, for gasoline engine, ε=6～10
Q The main causes of damage of automatic voltage regulator (AVR)

A AVR circuit is composed of rectifier main circuit, voltage detection circuit and comparison and control circuit; excluding the possibility that the damage is caused by the quality problems of the electric components, the working frequency of the main circuit and comparison and control circuit changes most among the whole AVR circuit. And the rectifier bridge in the main circuit and the transistor in the comparison circuit change even more frequently, and their damage proportion accounts for more than 90% of the whole AVR damage rate. AVR is non-dismantle components, and if it is damaged, it needs to be replaced. Therefore, we mainly analyze the reason that causes the damage of AVR in the generator and to avoid AVR damage as much as possible is the most important.

The service life of AVR can be increased if it is used properly.

(1)If the voltage of the engine is more stable, the change in AVR is less frequent; if the switch motion of transistor in comparison circuit is gentler, the AVR damage probability rate is less;

(2) If the output load is relatively stable, the change in AVR is less frequent, and if the switch motion of transistor in comparison circuit is gentler, the AVR damage probability rate is less;

(3)If the rotational speed of the engine is more stable, the oscillatory surge that currency variance causes to AVR is less;

(4)Frequent “idle running”, overload running and great difference of load are the main causes of AVR damage.

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FAQ Category

FAQ

Q What is the self-sucking pump and what is its working principle?

Q Interpretation of relevant terms of the engine

Q The main causes of damage of automatic voltage regulator (AVR)