Patent ID: 6585092
Filing Date: 2003-07-01
Classification: F16D

Abstract:
A viscous fluid, fan clutch for a fan drive assembly, said viscous fluid clutch comprisinga rotor assembly comprising (i) an input shaft having a fan drive end, (ii) a cast metal hub attached to said shaft at said fan drive end, coaxial therewith, and extending radially to a circular perimeter and (iii) a ferrous metal, rotor ring having a first edge incorporated into the perimeter of said cast hub, coaxial with said input shaft, and extending axially to a second edge in a direction from the drive end of said input shaft; a bearing having inner and outer races and fixed on its inner race to said input shaft; a circular fan housing coaxial with said input shaft and fixed to the outer race of said bearing, said housing extending radially past said rotor ring and defining a viscous fluid gap between said housing and rotor; and a fan drive cover assembly comprising (i) an annular non-ferrous metal fan cover body with an edge in sealing engagement with said fan housing outboard of said rotor, and (ii) a circular ferrous metal fan drive cover insert having a circumferential surface in sealing engagement with the inner annular surface of said fan cover body, and a flat surface spaced axially from the end of said input shaft; said fan cover insert initially being made as a single piece, said nonferrous fan cover body being cast against the circumferential surface of said fan cover insert in forming said fan drive cover assembly and said assembly being thereafter machined axially through the radially outer portion of said fan cover insert to separate a fan cover insert ring portion from a fan cover insert wheel portion and to form a slot through said fan cover insert into said fan cover body to receive said rotor and thereby to define a gap on both radial surfaces and around said second edge of said rotor between slot surfaces of said fan cover insert for a viscous fluid.