6
8
12
5
2
11
7
13
9
10
3
4
1. Body 7. Torsion pack
2. Socket 8. Hub
3. Fork 9. Washer
4. Hub 10. Hub
5. Nut 11. Hub
6. Baffle 12. Hub
Figure 4.9. ANTI-TORQUE ROTOR HUB
PROPULSION AND TRANSMISSION
5.1. GENERAL INFORMATON
The helicopter’s propulsion is mainly produced by the engine.
The helicopter features a piston engine Subaru EJ-25, which is horizontal, four-cylinder, opposed, four-act, and liquid-cooled. Its working volume is 2500 cm3, power – 165 horsepower (121 kW). The engine has a sixteen-valve gas-distributing mechanism with a distribution shaft in each of the two cylinder heads.
The engine is flexibly affixed to the framework. It is positioned in such a way, that with a specified centering it provides easy access to the devices which demand frequent service.
The helicopter’s transmission (Fig. 5.1) provides the power transfer from the engine to the rotors, with rotary speed being the most advantageous for both rotors. Transmission is also responsible for the concrete direction of rotors and the power transfer for other devices and mechanisms.
Главный редуктор Propulsion reduction
gear
Ременная передача Belting
Обгонная роликовая муфта Free-wheel roller clutch
Пластинчатая муфта Plate clutch
Промежуточная опора Pillow block
Трансмиссионный вал Transmission shaft
Пластинчатая муфта Plate clutch
Рулевой редуктор Steering reduction gear
Двигатель Engine
Резиновая муфта Rubber clutch
Fig. 5.1. TRANSMISSION LAYOUT
5.2. ENGINE
5.2.1. The engine’s design philosophy:
- pyramidal combustors with spark-plug in the center and four valves (2 exhaust, 2 admission ones) for one cylinder;
- valve-levers are equipped with gap hydro-compensators;
- distribution shafts (in the left and right heads) are activated by one cogged belt, which also activates the cooling system pump situated in the left engine half-block. The cogged belt’s tension is regulated automatically;
- the supporting crankshaft is positioned in the five main-bearings;
- the cylinder block is made of aluminum alloy through pressure die casting and is equipped with dry cast-iron liners mounted into the floor of the block.
5.2.2. Cooling system.
The propulsion cooling system is liquid-based. The cooling system radiator is situated in the lower part of the frame and forcibly cooled by the airflow created by two electric fans with step-by-step activation, mounted on the fan baffle above the radiator. For air supply from the approach flow, there is a fresh-air intake.
5.2.3. Engine starting system
The engine starting system is regular. The engine is equipped with an electric starter, a starter relay, and a starter button. The engine is started from a storage battery with the capacity of 60 ./hr.
The storage battery is charged by a 12 V 70 . generator, whicj includes a voltage control box and an electronic rectifier.
5.3. TRANSMISSION
5.3.1. The belting is responsible for power transfer through the flexible rubber clutch and the free-wheel roller clutch from the engine to the reduction gear drive shaft. The belt is a V-belt. There are seven belts.
5.3.2. The propulsion reduction gear is single, transmitting the rotational moment from the engine to the rotor shaft. The transmission is conical, with a circular cog. The propulsion reduction gear has one entrance.
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本文鏈接地址：Ultra light Helicopter AK1-3(6)
