Patent ID: 8172557

Claim:
A gas compressor comprising: (a) a compressor body that comprises a cam case and at least one cylinder block; (b) a cylinder bore formed within said cylinder block and open onto said cam case and externally onto an outer surface of said cylinder block; (c) a cylinder head covering said outer surface of said cylinder block and comprising an inlet passage through which an intake gas stream is introducible into said cylinder bore and a discharge passage through which a discharge gas stream is dischargeable from said cylinder bore; (d) an inlet valve disposed in said inlet passage of said cylinder head; (e) an outlet valve disposed in said discharge passage of said cylinder head; (f) a camshaft rotatably mounted in said cam case with a cam associated with said camshaft that is aligned with a centerline axis of said cylinder bore; (g) a single-acting piston reciprocable within said cylinder bore; (h) a roller tappet assembly interposed between said piston and said cam for transmission of reciprocating motion from said cam to said piston, said roller tappet assembly comprising: a tappet body contactable with said piston; a roller with a rolling surface in contact with the perimeter surface of said cam; and a pin extending through said roller defining an axis of rotation, wherein said pin is supported by mounting points provided by said tappet body; and (i) a pressure compensation passage within said compressor body through which a pressurized gas is introducible to a pressure compensation chamber interposed between said piston and said cam case, wherein said pressure compensation chamber is bounded in part by a surface of said piston that is opposite to a surface of the piston that faces said cylinder head, and wherein said pressure compensation passage is fluidly connected to said surface of said piston that is opposite to said piston surface that faces said cylinder head.