Patent ID: 8025346

Claim:
A machine comprising: a first machine component having a cylindrical inner wall defining a cylindrical bore having a first bore end, a second bore end and a uniform bore diameter from the first bore end to the second bore end; and a second machine component defining a longitudinal axis and having a first end, a second end and an axial length extending between said first and second ends, the first end being retained within said cylindrical bore by a press fit; said second machine component further including a non-directional surface finish disposed along a portion of its axial length within said bore which forms a fluid seal with said cylindrical bore, and a directional surface finish disposed along a different portion of its axial length within said cylindrical bore which inhibits removal of the first end from said bore, the directional surface finish being positioned adjacent the first end and including an axially asymmetric surface finish element contacting the cylindrical inner wall; wherein a disassembly direction is parallel the axial length of the second machine component and extends from the first end toward the second end, and an assembly direction has an orientation opposite to the disassembly direction; wherein the press fit includes a first press fit strength in the assembly direction, and a second press fit strength in the disassembly direction which is greater than the first press fit strength; wherein the axially asymmetric surface finish element includes a first surface sloping toward the longitudinal axis in the assembly direction, whereby sliding of the surface finish element against the cylindrical inner wall in the assembly direction is uninhibited during press fitting the first and second machine components together; wherein the axially asymmetric surface finish element further includes a second surface adjoining the first surface and sloping toward the longitudinal axis in the disassembly direction, whereby sliding of the surface finish element against the cylindrical inner wall in the disassembly direction is inhibited once the first and second machine components are press fit together; and wherein a slope of the second surface is steeper than a slope of the first surface, relative to the longitudinal axis.