Piston ring seal with reduced stiction

A piston and cylinder assembly structured to reduce breakaway friction between the piston and cylinder upon initial movement of the piston within the cylinder, the assembly comprising:

• (a) a cylinder having a cylinder wall and a cylinder head, the cylinder wall having an inside diameter, the cylinder further comprising at least one fluid flow port through at least the cylinder head or the cylinder wall;
• (b) a piston movably arranged within the cylinder, the piston and the cylinder together defining at least one variable volume internal chamber, the piston comprising:
• (i) a piston crown comprising a top face and a peripheral groove, the peripheral groove comprising an inner wall portion, and upper and lower side wall portions extending to a perimeter opening, the peripheral groove having a width, a depth, and an inner wall portion diameter, the piston crown further comprising at least one passageway between the top face of the piston crown and the inner wall portion of the peripheral groove;
• and
• (ii) a piston shaft connected to and supporting the piston crown, the piston shaft extending from the piston crown;
• and
• (c) a sealing ring positioned on the piston in the piston peripheral groove, the sealing ring having a thickness approximately equal to the width of the peripheral groove, the sealing ring having an outer diameter approximately equal to the inside diameter of the cylinder wall and an inner diameter greater than the diameter of the inner wall portion of the peripheral groove;
• wherein the piston, with the sealing ring in a relaxed condition, experiences little or no friction between the piston and the cylinder wall;
• and
• wherein an increase in a volume of fluid material within the at least one variable volume internal chamber between the piston and the cylinder initially moves the piston outward within the cylinder, and directs a portion of the increasing volume of fluid material through the at least one passageway between the top face of the piston crown and the inner wall portion of the peripheral groove, thereby pressing the sealing ring into more forceful contact with the cylinder wall to form a tighter seal between the piston and the cylinder.