Question 47 AEL01 - Assistant Engineer - Limited

The Correct Answer is B **Explanation for Option B (Blower timing gears):** Blower timing gears are the critical component used in a Roots-type blower (a positive displacement pump) to maintain a precise clearance between the rotating lobes (or rotors). The gears are mounted on the shafts of the two rotors and are meshed externally. By ensuring the rotors turn in a synchronized, fixed relationship, the gears prevent the lobes from colliding, which would cause severe damage and operational failure. They are responsible for the mechanical non-contact operation of the rotors. **Why the other options are incorrect:** * **A) Drive chain:** The drive chain connects the engine (or another power source) to the blower's input shaft. Its purpose is to transmit power and rotational energy, not to synchronize the internal lobes or prevent them from contacting each other. * **C) Air trapped between blower lobes:** While the air is compressed and moved by the lobes, the trapped air is a result of the blower's operation (moving fluid), not a physical mechanism designed to prevent the lobes from making contact. The lobes maintain clearance due to mechanical synchronization (the timing gears), not pneumatic pressure. * **D) Oil filter between blower lobes:** The oil filter is part of the lubrication system, cleaning the oil used for the bearings and gears. It is located externally to the compression chamber and plays no role in maintaining the physical clearance or timing between the moving lobes.