CEILING CENTRIFUGAL FAN Russian patent published in 2000 - IPC

FIELD: mechanical engineering; general application ceiling centrifugal fans. SUBSTANCE: fan is designed for use in vehicles in confined spaces under vibration and acoustic excitation conditions. In proposed ceiling fan electric drive is mounted on support plate. On vertical shaft of motor impeller with backward curved blades and conical cover disk is mounted. Disk is provided with curvilinear section. Fan has suction branch pipe with curvilinear section entering impeller and forming recirculation clearance with cover disk, and carrying disk provided with stamping at electric drive shaft for mounting impeller on shaft. Suction branch pipe is installed with hermetic sealing relative to inner surface of vehicle and is furnished with at least two symmetrically mounted air intakes whose summary cross section area is 0.6-0.8 of entry area. Stamping is made in form of round truncated cone whose surface is parallel to conical surface of cover disk, and axial length is 0.55-0.8 of axial length of impeller. Support plate has at least three posts for fastening suction branch pipe with intermediate ring secured on posts with clearance equal to 0.4-0.6 of post working length, outer and inner diameter of ring being 1.9-2.2 and 1.27-1.58 of impeller outer diameter, respectively. EFFECT: reduced aerodynamic losses and vibration and acoustic activity of fan. 1 dwg