Mantlebearing

Mantlebearing is a term used in some mechanical engineering texts to describe a type of plain bearing in which the bearing surface is provided by a mantle—a cylindrical shell that forms the bearing bore around a rotating shaft journal. The term is not universally standardized, and in many references such devices are simply called sleeve or journal bearings. In mantlebearings, lubrication creates a thin film that separates the metal surfaces, reducing wear and friction.

Construction and operation: The mantle is typically produced as a liner of bronze, babbitt, or other bearing material fitted into a housing and may be split to simplify installation and replacement. Lubrication is supplied by oil or grease channels, and clearances are designed to permit hydrodynamic film formation at operating speeds. The bearing's load capacity, speed, and operating temperature influence material choice and mantle thickness, with wear and heat management guiding maintenance.

Applications and history: Mantlebearings have been used in various older industrial machines, including steam engines and textile equipment, as well as in some pumps and turbines. They offer replaceable bearing surfaces and straightforward maintenance, but require proper lubrication, alignment, and periodic inspection to prevent excessive wear or seizure.

Materials and maintenance considerations: Common mantle materials include babbitt-lined bronze, plain bronze, and cast iron, sometimes with composite liners. Routine maintenance emphasizes lubricant condition and cleanliness, inspection of surface finish and clearance, and timely replacement of the mantle or lining when wear becomes excessive. Because terminology varies, practitioners may refer to these components as sleeve bearings or journal bearings depending on the context.