AXIAL-FLOW FAN AND METHOD OF ASSEMBLY OF SUCH FAN Russian patent published in 1999 - IPC

FIELD: manufacture of fans, axial-flow fans, in particular; temperature control systems of space equipment where stringent standards in noise level are required. SUBSTANCE: axial-flow fan includes cylindrical housing with impeller mounted on electric motor shaft arranged inside it. Electric motor is secured on fan housing by means of bush having radial projections. Housing is provided with bosses on its inner surface according to number of projections of bush. Outer surface of each projection and inner surface of respective boss are made in form of engageable spheres of one diameter whose center lies in axis of fan. Inner surface of housing is made in form of smooth cylindrical surface; diameter of engageable spheres D₁ is found from the following relationship: , where d is diameter of hub of bush; b is maximum distance from plane perpendicular to longitudinal axis of fan running through center of engageable spheres to point of intersection of lateral generatrix of projection with hub of bush in plane passing through longitudinal axis of fan and axis of projection; D is diameter of inner cylindrical surface of housing; h is minimum thickness of boss in plane perpendicular to axis of fan. Bosses are detachable; they are fixed relative to housing and projections of bush in longitudinal and circumferential directions; outer surface of bosses is cylindrical in shape; its diameter is equal to diameter of inner surface of housing; boss and projection of bush are identical in section perpendicular to axis of projection. Method of assembly of axial-flow fan includes mounting the bush inside housing, aligning the centers of spherical surfaces of bush and housing, mounting the electric motor and impeller and locking the bush on housing. Prior to mounting the bush, bosses are secured in housing against shifting in longitudinal and circumferential directions; in mounting the bush inside housing, it is turned to such position that its projections are positioned between bosses; after aligning the centers of spherical surfaces, bush is turned relative to its longitudinal axis in circumferential direction to match projections of bush and bosses; in mounting the electric motor and impeller, even clearance shall be ensured between impeller blades and housing; then housing, boss and bush are fixed in required positions relative to one another. EFFECT: enhanced efficiency; reduction of noise due to reduction of turbulence of flow of air inside housing. 3 cl, 5 dwg