Tennessee Wastewater Operator Practice Exam

What type of bearings creates a pressurized "air cushion" in a turbo blower system?

1. Ball bearings

2. Roller bearings

3. Air foil bearings

4. Journal bearings

The correct answer is: Air foil bearings

Air foil bearings are designed to create a pressurized "air cushion," which supports the rotor of the turbo blower in a way that significantly reduces friction. This technology involves the use of aerodynamics to maintain a gap between the bearing surface and the rotor, allowing air to flow in and form a cushion. This cushion supports the weight of the rotor during operation, enabling high-speed rotation with minimal wear and tear on the components. The advantages of air foil bearings include reduced energy consumption due to lower friction, enhanced performance efficiency, and increased longevity of the machinery. This technology is particularly suitable for applications like turbo blowers where high speeds and precisions are crucial. In contrast, the other types of bearings mentioned—ball bearings, roller bearings, and journal bearings—typically rely on contact between moving surfaces. They do not create an air cushion and, as a result, have different operational characteristics and limitations regarding speed and friction.