Oilers/Plant Tenders (HHC) Civil Service Practice Exam

A thrust bearing is LEAST likely to be found on a(n) __________.

1. Electric motor

2. Reciprocating pump

3. Centrifugal pump

4. Conveyor system

The correct answer is: Reciprocating pump

A thrust bearing is a type of bearing designed to support axial loads, which are forces that act along the axis of a rotating shaft. In applications where axial loads are significant, such as in electric motors or centrifugal pumps, thrust bearings play a crucial role in ensuring operational stability and reducing wear. In the context of a reciprocating pump, the mechanism primarily involves linear motion rather than significant rotational motion. These pumps operate by creating a suction effect as a piston moves back and forth within a cylinder, resulting in the generation of fluid flow. The forces involved in this type of pump predominantly lead to radial loads rather than axial loads due to the nature of the piston movement. Consequently, a thrust bearing, which is specifically designed to handle axial loads, is not typically a necessary component in this design, making it the least likely application for a thrust bearing. In comparison, electric motors and centrifugal pumps are designed to handle rotational motion where axial forces can be prevalent, thus requiring thrust bearings for proper functioning. Conveyor systems may require thrust bearings depending on their specific design and operations, especially if they involve elements that create axial loads.