Abstract: A counter-rotating fan assembly includes an upstream fan that rotates in a first direction about a common axis and a downstream fan that rotates in a second, opposed direction about the common axis. The assembly has an upstream motor that drives the upstream fan, and an upstream motor support that supports the upstream motor. The assembly also has a downstream motor that drives the downstream fan, and a downstream motor support that supports the downstream motor. The upstream motor support is located upstream of the upstream fan, and the downstream motor support is located downstream of the downstream fan.

Abstract: High efficiency and low noise is achieved in an automotive engine-cooling fan assembly by flaring the inlet to the shroud barrel, and shaping the tips of the fan blades to conform to the shape of the inlet. Separation of the flow entering the fan is reduced by extending the flare over the axial extent of the blade tip, and tip clearance losses are reduced by controlling recirculation along the entire blade tip. Blade rake is used to minimize fan deflection, thereby allowing the use of small tip clearances, which further enhance performance.

Abstract: High efficiency and low noise is achieved in an automotive engine-cooling fan assembly by flaring the inlet to the shroud barrel, and shaping the tips of the fan blades to conform to the shape of the inlet. Separation of the flow entering the fan is reduced by extending the flare over the axial extent of the blade tip, and tip clearance losses are reduced by controlling recirculation along the entire blade tip. Blade rake is used to minimize fan deflection, thereby allowing the use of small tip clearances, which further enhance performance.

Abstract: An improvement to forwardly skewed axial fans whereby blade camber and rake are coordinated with skew. The blades are characterized in that a line defined by the points of maximum chordwise camber (f.sub.max) as a function of changing radial position (r) is on the leading edge side of the mid-chord line (M.sub.CL) at values of r toward the root of the blade, and is less forwardly skewed than the leading edge (LE), the mid-chord line (M.sub.CL), and the trailing edge (TE) of said blade; the blade is raked forwardly so that the trailing edge of the blade tip is axially forward of the trailing edge at the blade root; rake (k) increases monotonically as radial position r increases from 0.75R to 1.0R, R being the fan radius; the blade has a relatively large pitch ratio (P/D); and rake is corrected to reflect the chordwise position of maximum camber.

Abstract: A centrifugal blower with rearwardly curved impeller blades positioned in a housing between two housing faces that are spaced apart along the impeller axis. One of the housing faces defines a housing inlet. The housing is substantially closed off with the exception of the inlet and an outlet. The blower is generally characterized in that the: (a) clearance between the impeller blades and at least one of the housing faces is greater than 30% of the impeller blade depth; (b) the impeller diameter is at least 70% of the housing dimension along that diameter; and (c) area of the blower outlet is greater than 70% of the area of a section of the housing taken perpendicular to the direction of airflow along the impeller axis.