Unformatted text preview: ngs also transfer heat from the piston to the
cylinder liner and absorb some part of the piston fluctuation due to the side thrust.
The oil control rings or oil scrapers are provided below the compression rings. These rings
provide proper lubrication to the liner by allowing sufficient oil to move up during upward stroke and
at the same time scraps the lubricating oil from the surface of the liner in order to minimise the flow
of the oil to the combustion chamber.
The compression rings are usually made of rectangular cross-section and the diameter of the
ring is slightly larger than the cylinder bore. A part of the ring is cut- off in order to permit it to go into
the cylinder against the liner wall. The diagonal cut or step cut ends, as shown in Fig. 32.4 (a) and (b)
respectively, may be used. The gap between the ends should be sufficiently large when the ring is put
cold so that even at the highest temperature, the ends do not touch each other when the ring expands,
otherwise there might be buckling of the ring. 1136 n A Textbook of Machine Design Fig. 32.4. Piston rings. Th...
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- Spring '11
- Combustion, Internal combustion engine, pistons, Connecting rod, Engine technology, piston pin