Viscous shear drives and methods using nanoparticles in the viscous medium

Abstract: A device such as a cooling fan drive for a motor vehicle engine has first and second members that are relatively moveable at a differential velocity. A liquid fills space separating relatively moving confronting surfaces of the respective members. The viscosity of the liquid enables the liquid to serve as a motion transmitting medium from one member to the other. Heat is generated within the liquid by shearing stress created by the relative movement of the members at a differential velocity with at least some of the generated heat being dissipated by conduction from at least one of the members through its surface. The viscous liquid comprises a nanoparticle-free base liquid to which have been added nanoparticles in an amount sufficient to measurably increase the thermal conductivity of the liquid filling the space over that of the base liquid.