Abstract: A motor case assembly 20 a permanent magnet D.C. electric motor includes a motor case 24 having a generally cylindrical wall 25, a closed end 21, and an open end 23 opposite the closed end, defining an interior 27. Permanent magnet structure 26 is mounted to the wall 25 in the interior 27. A surface defines at least one hole 22 through the wall 25. The hole 22 is constructed and arranged to be employed in mounting the case 20 to a shroud to obtain a mass balance distribution of a motor shroud assembly.

Abstract: A fan shroud structure (10) is constructed and arranged to carry a fan and motor. The fan shroud structure includes a base (12) and an annular rim (24) extending from the base. The rim defines a generally central opening (26) sized to accommodate blades of a fan. Motor mounting structure (28) is coupled with the rim (24) and is disposed generally adjacent to the central opening (26). The motor mounting structure (28) is constructed and arranged to support a motor for driving a fan. The fan shroud structure (10) includes a first pair of opposing sides (14, 16) and a second pair of opposing sides (17, 18) coupled to the base to form a box-like configuration defining a perimeter of the fan shroud structure raised with respect to the base such that the sides are discontinuous with respect to the base (12) to shift resonance of the shroud structure.

Abstract: A fan shroud structure 10 is constructed and arranged to carry a fan and motor. The fan shroud structure includes a base 12 and an annular rim 24 extending from the base. The rim defines a generally central opening 26 sized to accommodate blades of a fan. Motor mounting structure 28 is coupled with the rim 24 and is disposed generally adjacent to the central opening 26. The motor mounting structure 28 is constructed and arranged to support a motor for driving a fan. The fan shroud structure 10 includes a first pair of opposing sides 14, 16 and a second pair of opposing sides 17, 18 coupled to the base to form a box-like configuration defining a perimeter of the fan shroud structure raised with respect to the base such that the sides are discontinuous with respect to the base 12 to shift resonance of the shroud structure.

Abstract: A fan shroud structure 10 is constructed and arranged to carry a fan. The fan shroud structure includes a body 12 having a periphery, a main surface, and an annular rim 26 defining a generally central opening 28. The opening 28 is sized to accommodate blades of a fan. Fan mounting structure 30 is coupled with the body and is disposed generally adjacent to the central opening. The fan mounting structure is constructed and arranged to support a motor of a fan. The body includes a plurality of surfaces features 34 constructed and arranged to affect resonance of the shroud structure with each feature having a surface 36 that is discontinuous with respect to the main surface 38 of the body. Each feature 34 also extends from the annular rim to the periphery of the body.

Abstract: A motor case assembly 20 a permanent magnet D.C. electric motor includes a motor case 24 having a generally cylindrical wall 25, a closed end 21, and an open end 23 opposite the closed end, defining an interior 27. Permanent magnet structure 26 is mounted to the wall 25 in the interior 27. A surface defines at least one hole 22 through the wall 25. The hole 22 is constructed and arranged to be employed in mounting the case 20 to a shroud to obtain a mass balance distribution of a motor shroud assembly.

Abstract: A fan 10 includes a central hub 14, an outer ring structure 18, and a plurality of fan blades 12. Each blade is of generally Y-shaped configuration having first and second separate branches 12a, 12b, respectively, coupled to the hub 14 and merging with a third branch 12c. The third branch 12c is coupled to the ring structure 18 at a tip 16 of the blade 18.

Abstract: A fan 10 includes a central hub 14, an outer ring structure 18, and a plurality of fan blades 18. Each blade is of generally Y-shaped configuration having first and second separate branches 12a, 12b, respectively, coupled to the hub 14 and merging with a third branch 12c. The third branch 12c is coupled to the ring structure 18 at a tip 16 of the blade 18.

Abstract: A fan 10 includes a hub 12, a plurality of fan blades 14 attached to the hub at one end and extending outwardly from the hub, and a ring 18 concentric with the hub and coupled to tips 16 of the blades. A dimensionless radius (r/R) is defined from a center of the hub (r/R=0) radially outwardly, wherein each tip of the blades is r/R=1. A pitch ratio increases up to about r/R=0.85, and decreases in a range of about 0.85<r/R<1.0. In the range of about 0.6<r/R<1.0, a chord length decreases continually.

Abstract: A fan shroud structure 10 is constructed and arranged to carry a fan. The fan shroud structure includes a body 12 having a periphery, a main surface, and an annular rim 26 defining a generally central opening 28. The opening 28 is sized to accommodate blades of a fan. Fan mounting structure 30 is coupled with the body and is disposed generally adjacent to the central opening. The fan mounting structure is constructed and arranged to support a motor of a fan. The body includes a plurality of surfaces features 34 constructed and arranged to affect resonance of the shroud structure with each feature having a surface 36 that is discontinuous with respect to the main surface 38 of the body. Each feature 34 also extends from the annular rim to the periphery of the body.

Abstract: A fan 10 includes a hub 12, a plurality of fan blades 14 attached to the hub at one end and extending outwardly from the hub, and a ring 18 concentric with the hub and coupled to tips 16 of the blades. A dimensionless radius (r/R) is defined from a center of the hub (r/R=0) radially outwardly, wherein each tip of the blades is r/R=1. A pitch ratio increases up to about r/R=0.85, and decreases in a range of about 0.85<r/R<1.0. In the range of about 0.6<r/R<1.0, a chord length decreases continually.