scraper ring

scraper ring

[′skrāp·ər ‚riŋ]
(mechanical engineering)
A piston ring that scrapes oil from a cylinder wall to prevent it from being burned.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

scraper ring

The bottom ring on a piston whose function is to scrape lubricating oil away from the cylinder walls of a reciprocating engine. This prevents the oil from getting into the combustion chamber of the cylinder. Also called a wiper ring.
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved
References in periodicals archive ?
The engine was disassembled: three piston skirts were broken, the bottom scraper ring from each broken piston was found in the oil sump.
There is a scraper ring inside the swivel lock actuator that keeps dirt and grime from entering the actuator.
The engines use oil-cooled three-ring pistons with two compression rings and an oil scraper ring. The connecting rod is forged steel.
"Their concentration on retaining an oil sump, oil scraper rings, and relying on plain bearings instead of roller bearings," he theorizes, "increased the amount of oil burned, which harmed emissions performance." And it may be another reason why automotive two-stroke emission performance degraded over time.