UNCOOLED OILLESS INTERNAL COMBUSTION ENGINE HAVING UNIFORM GAS SQUEEZE FILM LUBRICATION

摘要

An apparatus for providing a gas phase film lubricaiton between a reciprocal piston and a cylinder of an uncooled oilless internal combustion engine; the piston is effective to drive a rotary crankshaft in response to an expanding gas charge. The apparatus comprises: (a) means connecting the crankshaft to said piston for transferring reciprocal thrust into rotary thrust, such means aligning the piston concentrically within the cylinder wall to limit the imposition of side loads on said piston (i.e., less than 80 psi); (b) interfacing walls on the piston and cylinder (i) sized to provide a predetermined annular gap therebetween at ambient conditions that has a radial dimension in the range of .001 ? .0005 inches, (ii) consisting of matched materials that prevent closure of the gap due to thermal expansion under the maximum temperature differential to be experienced between the piston and cylinder wall, and (iii) are preshaped to anticipate any thermal growth of the interfacing walls for maintaining the annular gap substantially constant at elevated temperatures. 2566L