Patent ID: 7044282

Claim:
A viscous fan drive for cooling an engine, the viscous fan drive comprising: an input member comprising an input shaft and a body, said body having a seal ring, said input member rotating as a function of a given engine speed; an output member bearing supported around said input shaft, said output member comprising a cover; a seal pressed into said cover and sealingly engaged to said body, a chamber defined by said body, said cover, and said seal; a pump plate coupled to said output member and contained within said chamber, said pump plate having a fill port; a fluid reservoir defined by said pump plate and said cover; an operating chamber defined by said cover and said body, said operating chamber fluidically coupled to said fluid reservoir through said fill port; and a quantity of viscous fluid contained within said fluid reservoir and said operating chamber, wherein the relative amount of said quantity of viscous fluid within said operating chamber controls the torque engagement of said output member at a given rotational speed of said input member.