Correct Answer - Option 2 : precision insert
Explanation:
Bearing is installed wherever there is a relative motion between two parts. Bearing consists of steel shell or bronze shell (sleeve) lined with the bearing material called Babbitt metal. The bearing material is relatively soft so that bearing wears out over period of time, not journal.
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Precision Insert
- In high-speed compressors, Precision Insert bearings are used.
- The insert bearings are finished with precision and can be used on the compressor without the necessity of machining, scraping, and finishing after fitting on the compressor.
- These precision bearings are only scraped or machined at all as the bearing lining on the shell is quite thin.
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Sleeve type bearing
- In refrigeration compressors, sleeve type bearings are used.
- For axial compressors, Journal bearings are of plain sleeve type for the larger slower speed compressor
- These are called so as they are in the form of a sleeve over the parts in motion such as on the main journals of the crankshaft on the crankpin
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Bronze bearings
- are used in slow-speed compressors
- Soft bronze bushings are selected. The bronze material is oil impregnated to provide lubrication.
