The primary purpose of a thrust bearing in a large reaction steam turbine includes which of the following?

The primary function of a thrust bearing in a large reaction steam turbine is to handle axial loads, ensuring that the rotor maintains its position along the axis of the turbine. The correct answer highlights a common misconception, as the thrust bearing does not primarily function to prevent steam from escaping.

Thrust bearings are designed to absorb axial thrust generated by steam pressure acting on the turbine blades as they rotate. This axial load could push the rotor in one direction, and without effective thrust bearings, the rotor may move out of its intended path, leading to mechanical misalignments or failures.

By maintaining the rotor's position, thrust bearings protect the integrity of the turbine and ensure efficient operation. They also allow the system to operate smoothly by minimizing wear and tear on components.

While supporting other components like the dummy piston and managing radial thrust do play roles in the overall design of the turbine system, these are not the primary functions of a thrust bearing. The key role of the thrust bearing fundamentally revolves around managing axial forces and ensuring the rotor remains stable during operation.