Fan casing volute

Claim 1

Improvements in a fan volute of a fan of the centrifugal blower type which comprises two volute portions, and means joining the volute portions to form a volute assembly, each said volute portion being a monolithic moulding of polymeric material of dense foam sandwiched between impervious skins, and comprising an end plate with surfaces defining an air intake aperture, a hollow bearing housing in the aperture, and a plurality of arms extending outwardly from the bearing housing to the end plate thereby supporting the bearing housing from the end plate, each said arm being of generally U-shape in cross-section, the thickness of the polymeric material in each said volute portion being substantially constant throughout each respective said portion including throughout each said arm of generally U-shaped cross-section each said volute portion further having a bearing in the bearing housing, an annular ring of elastomeric material surrounding the bearing and engaging an inner surface of the bearing housing, and a bearing retainer retaining the bearing in the bearing housing, each said volute portion further having a cooperating boyonet lugs on the retainer and bearing housing.