Mounting nut retention for fluid couplings

Claim 1

A mounting for connecting a viscous fan coupling with a mounting shaft that is rotatable about an axis, the coupling having a housing member defining a reservoir containing fluid, a rotor member located within the reservoir and operative with the fluid to rotate with the housing member about an axis, an input shaft having an axis coaxial with the axis of the members and secured to one of the members to rotate the one member, and the other member being adapted to support a fan, the mounting comprising: A. a radially extending surface on the mounting shaft perpendicular to the axis of the mounting shaft; B. at least one annular thread on the mounting shaft substantially concentric with the axis of the mounting shaft; C. a flange on the input shaft extending radially outwardly from the axis of the input shaft; D. a contact surface on the side of the flange closest to the one member; E. a radially extending surface on the side of the flange opposite from the contact surface, perpendicular to the axis of the input shaft, and adapted to be matingly engaged with the radially extending surface on the mounting shaft; F. an annular nut loosely encircling the input shaft, the nut having a surface adapted to engage the contact surface; and G. at least one annular thread on the nut substantially concentric with the axis of the input shaft and threadedly engageable with the thread on the mounting shaft to move the mounting shaft toward the flange and force the perpendicular radially extending surfaces into tight frictional mating engagement with one another whereby torque may be transferred from the mounting shaft to the input shaft during rotation of the mounting shaft.