supportbearing

A support bearing is a bearing that provides support for a rotating shaft or structural element, transmitting loads to a supporting structure while allowing relative motion between parts. In common engineering usage, the term can refer to mechanical bearings that support shafts in machines, or to structural bearings used in civil engineering applications to accommodate movement while carrying loads.

In machinery, support bearings primarily carry radial and/or axial loads and maintain shaft alignment within the housing. They reduce friction between moving parts and can contain lubrication to extend life. Common forms include plain (sleeve) bearings, which rely on a lubricant film; and rolling-element bearings, such as ball or roller types, which offer lower friction at higher speeds. Thrust or axial bearings are used when significant end loads must be transmitted along the shaft.

Structural support bearings support loads in buildings and bridges while permitting controlled movement due to temperature changes, settlement, and seismic or wind forces. Typical types include elastomeric bearings, which use rubber-like material to absorb movement; pot or rocker bearings, which provide rotational freedom; and sliding or PTFE-based bearings, which allow sliding as the structure expands or settles. These devices help preserve alignment of structural members and limit stress concentrations.

Design and maintenance considerations vary by application. Mechanical support bearings require attention to load, speed, temperature, lubrication regime, contamination, and installation precision. Signs of wear or misalignment include increased vibration, noise, heat, and unusual shaft movement, and bearings should be inspected and replaced per manufacturer guidance. Structural bearings require inspection for cracking, extrusion of the elastomer, corrosion, and adequate clearance; lubrication is typically not needed for elastomeric types, but sliding bearings may require periodic relubrication.