Viscous fluid shear device having wiper fixedly coupled to housing assembly

A viscous fluid shear device comprising:

• a housing assembly that defines a working chamber having a plurality of first ribs, which are disposed concentrically about a central axis, the housing assembly comprising first and second housing members that are fixedly coupled to one another, the first housing member having a circumferentially extending wall and a viscous fluid return system, the circumferentially extending wall defining a working chamber channel having a radially inner surface, the viscous fluid return system having a wiper, a scavenge conduit and a nozzle, the wiper being unitarily and integrally formed with the circumferentially extending wall and projecting radially inwardly of the radially inner surface of the working chamber channel, the scavenge conduit having a scavenge inlet aperture, a first conduit portion and a second conduit portion, the scavenge inlet aperture being formed into the circumferentially extending wall and intersecting the wiper such that a first portion of a surface of the scavenge inlet aperture forms a leading end of the wiper, the scavenge inlet aperture being formed along a first longitudinal axis and having a first cross-sectional area taken perpendicular to the first longitudinal axis, the first conduit portion being formed in the circumferentially extending wall and intersecting the scavenge inlet aperture, the first conduit portion being formed along a second longitudinal axis, the second conduit portion intersecting the first conduit portion and extending radially inwardly therefrom, the nozzle extending circumferentially between the working chamber channel and scavenge inlet aperture, the nozzle being configured to discharge a viscous fluid directly into the scavenge inlet aperture;
• a rotor received in the housing assembly and being rotatable about the central axis relative to the housing assembly in a first predetermined rotational direction, the rotor having a disk portion having a plurality of second ribs that are disposed concentrically about the central axis and juxtaposed with the first ribs;
• and
• a reservoir disposed in the housing assembly and being in fluid communication with the scavenge conduit;
• wherein a radially inner surface of the working chamber channel is disposed from a circumferentially extending surface of the rotor by a first distance, wherein at least one point on a radially inner surface of the wiper is disposed from the circumferentially extending surface of the rotor by a second distance that is smaller than the first distance and wherein a point at which the nozzle intersects the scavenge input aperture is disposed a third distance from the circumferentially extending surface of the rotor, the third distance being less than the first distance and greater than the second distance.