Patent ID: 7137791

Claim:
An axial bearing arrangement for a reciprocating hermetic compressor comprising: a cylinder block mounted inside a shell and carrying a cylinder and a vertically disposed radial bearing hub; and a crankshaft mounted through the radial bearing hub and having a lower end portion projecting below the radial bearing hub and affixing a rotor of an electric motor, and an upper end portion projecting above the radial bearing hub and incorporating a peripheral flange, whose lower face defines a support annular surface and an eccentric portion, wherein the radial bearing hub incorporates an upper tubular extension that has an internal face radially bearing a corresponding extension of the crankshaft, an annular end face and an external face, around which is mounted an axial roller bearing, which is simultaneously seated on the radial bearing hub and on the support annular surface of the crankshaft, in order to maintain a certain minimum axial gap between said support annular surface and the annular end face of the upper tubular extension, the axial roller bearing comprising a circular cage containing an upper annular race, having an internal cylindrical face which maintains, with the external face of the upper tubular extension, an axial extension with an overlapping, which is dimensioned to provide a desired degree of restriction to the axial oil flow through a radial gap, directing most part of said oil flow upwardly, to the interior of the oil passage internal to the crankshaft and which leads said oil to the top of an eccentric portion, said upper annular race comprising an upper surface portion defining a base for sustaining the column of lubricant oil flowing through the oil passage.