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?
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ALug
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BBushing
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CChamfer
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DKnurl
Answer
Correct Answer: Bushing
Explanation
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:
Identify geometry and function: hollow cylinder acting as sleeve/bearing.Map to standard machine element terminology: bushing/plain bearing.Select “Bushing.”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