What is the purpose of using a sleeve bearing in a furnace motor?

Using a sleeve bearing in a furnace motor plays a crucial role in minimizing noise levels. Sleeve bearings are designed to provide a quiet operation because they reduce friction between moving parts. This type of bearing achieves this by using a cylindrical shape that allows for a continuous film of lubricant to form between the shaft and the bearing surface.

This design not only dampens vibrations but also minimizes the sounds produced during operation, making it an ideal choice for applications where noise reduction is a priority, such as in residential heating systems. Thus, when considering the operational environment of a furnace, focusing on noise levels is particularly important for comfort and overall user experience.

While sleeve bearings may contribute to other factors like durability and operational smoothness, their primary advantage in furnace motors is their ability to operate quietly, which aligns directly with the purpose highlighted in the correct answer.