Patent ID: 6192840
Filing Date: 2001-02-27
Classification: B27B,F02B

Abstract:
A drive unit of a portable handheld work apparatus including a chain saw, the drive unit comprising:an internal combustion engine having a cylinder including an upper crankcase half and a crankshaft defining a crankshaft axis;a work tool operatively connected to said crankshaft so as to be driven thereby;said crankshaft having a drive pin;a fan wheel attached to said drive pin;a fan housing made of plastic and being configured for accommodating said fan wheel therein;a metallic chassis including a crankcase sump as a lower crankcase half;said crankcase sump of said metallic chassis and said upper crankcase half conjointly defining a partition plane where said upper and lower crankcase halves are joined to each other;said metallic chassis having a flange surface lying essentially perpendicular to said crankshaft axis;said crankcase sump having an exposed end defining at least a portion of said flange surface; and,said fan housing having a housing base attached to said flange surface.