Machine elements — protective sleeves and guides Which term denotes a hollow cylindrical component commonly used as a protective sleeve, guide, or plain bearing between a shaft and housing?

Introduction / Context:
Rotating assemblies often include a sacrificial or replaceable element that provides low-cost wear resistance and guidance between two components. Identifying and specifying this element correctly is essential for reliable operation and maintainability.

Given Data / Assumptions:

• The part is hollow and cylindrical.
• It functions as a sleeve, guide, or bearing surface.
• Typical applications include shafts rotating in housings with moderate loads and speeds.

Concept / Approach:
A bushing (also called a plain bearing or sleeve bearing) is a cylindrical insert that reduces friction and wear. Materials include bronze, PTFE-lined composites, polymers, or sintered metals. Bushings are inexpensive, compact, and often self-lubricating. A lug is a protruding tab for attachment, a chamfer is an edge bevel, and a knurl is a surface texture to improve grip or press-fit retention.

Step-by-Step Solution:

Verification / Alternative check:
Consult component catalogs; bushings are specified by ID, OD, length, and material, with options like flanged ends or lubrication grooves, confirming the definition and usage.

Why Other Options Are Wrong:

• Lug: attachment tab, not a sleeve.
• Chamfer: edge feature.
• Knurl: surface pattern, not a separate component.

Common Pitfalls:

• Confusing bushings with bearings with rolling elements; bushings are plain bearings without balls or rollers.
• Neglecting lubrication or material compatibility, leading to premature wear.

Final Answer:
Bushing