buchas

Buchas, in mechanical engineering, are cylindrical sleeves that form a bearing surface between a shaft and a housing or between two moving parts. They are used to reduce friction, wear, and noise, and to align and support rotating or sliding components. Depending on design, they may be fixed in the housing or mounted on the shaft, and can be plain, flanged, or integral with a mounting feature.

Plain sleeve bushings provide a simple bore for the shaft; flanged bushings include a flange to position them axially. Some bushings are oil-impregnated or self-lubricating, while others require external lubrication. There are also solid and split versions; split bushings are designed for easier installation in assemblies without disassembly of shafts.

Materials vary: bronze and bronze-based alloys are common for strength and wear resistance; bronze-graphite or bronze-PTFE composites reduce friction; steel-backed bushings add rigidity; polymer and composite bushings (such as PTFE, UHMWPE, or filled nylons) offer low weight and maintenance in lighter-load applications.

Used in automotive components, industrial machinery, agricultural equipment, hinges, pulleys, and linear guides, buchas are chosen based on load, speed, and environmental conditions. Installation involves selecting the correct bore diameter, length, and fit (slip-fit for ease or interference fit for load transfer). Lubrication strategy depends on bushing type; wear is indicated by increased play, scoring, or ovality, requiring inspection and replacement.

Standards and tolerances vary by manufacturer and region; refer to technical data sheets. Proper maintenance extends service life, and incorrect fit or misalignment can cause premature failure.