Flutter free piston ring assembly
Reference Number: N 01-02
Inventors: Rao, V. Durga N.; Yeager, David A.
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.