Flutter free piston ring assembly
Reference Number: N 01-02
Inventors: Rao, V. Durga N.; Yeager, David A.
Owner: NISTAC
USPTO Link:5598763
Invention Summary
It is an object of this invention to overcome the problems recited above and to provide
an economical solution to them.
The invention is a piston ring assembly operative within a cylindrical wall to retain
fluid to one side. The assembly comprises: a piston having one or more spaced grooves
in the piston side wall, each groove defining a pair of interior groove surfaces spaced
apart a uniform distance; at least one sealing element presenting a pair of opposed
surfaces operating between and along the pair of groove surfaces, the sealing element
being capable of engaging the cylindrical wall, the spacing between the opposed surfaces
of the sealing element and the pair of interior surfaces of the groove being no greater
than ten microns; and a solid film lubricant mixture coating the groove surfaces and
at least the opposed surfaces of the sealing element, whereby surface adhesion of
the fluid present in the spacing inhibiting migration of such fluid through the spacing
and flutter of the sealing element in the spacing being essentially eliminated. The
assembly substantially, if not totally, eliminates ring flutter while maintaining
effective sealing. crevice volume is reduced, blow-by reduced, ring failure reduced
and oil pumping reduced.