Patent · US Expired

Method of making and using a piston ring assembly

US5430938A · kind A · utility

13Cited by
15References
12Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 14, 1994
Grant dateJul 11, 1995
Priority date
Expiry dateMar 14, 2014

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T29/49284
  • WIPO fieldMechanical elements
  • WIPO sectorMechanical engineering

Abstract

Method of making a piston ring assembly by providing a metallic (i.e. cast aluminum) piston with a crown and an annular depending side wall; machining a stepped annular groove in the side wall having a total height of at least 4 mm (preferably having a combined total height equal to the groove height less 60 microns or less); fabricating a pair of metallic (i.e. aluminum based) split annular compression rings nestable within said groove and effective to operate together as a superimposed unit to seal against both said step and groove; coating said groove and the non-mating surfaces of said rings with solid film lubricants (i.e. graphite, BN and MoS.sub.2); and inserting said pair of coated rings into said coated groove with their split ends out of superimposed alignment. Also a method of reducing piston ring blow-by for a piston ring assembly in a cylinder bore wall of an internal combustion engine, the wall being bathed with oil drawn from a reservoir comprising providing a machined piston and split compression rings as above and reciprocatingly operating the assembly in the bore wall for carrying out engine operation whereby the rings act in unison due to friction at their mating…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.