Radial flow fan with motor cooling and resilient support of rotor shaft

Abstract

A radial flow fan of short axial length and large radial dimensions and of the type having the drive motor arranged coaxially with respect to the fan wheel and at least partly inside of the fan wheel. The housing for the fan wheel and motor includes a flat metallic square plate forming an axial end face and a synthetic resinous material circumferential housing attached to the metal plate. The circumferentially extending housing portion also includes a portion defining the opposite end wall of the casing with respect to the metal plate end wall, which opposite end wall has a central opening for inlet of air. The synthetic resinous housing portion includes an exit port for radial exit of the air. The metal plate is connected with good heat conductivity with the stator of the drive motor by way of a flange of a bearing for the shaft of the drive motor and by way of a contact disc which axially supports the rotor shaft at the metal plate. The contact disc is constructed so as to simultaneously form a resilient support for the rotor shaft and a firm seal at the bearing sleeve. The fan blades are connected to the rotor by way of a collar having offset portions engageable with corresponding offset portions of the rotor and with deformable wall members on the rotor engageable in recesses on the blade wheel collar so as to hold the same in position. Axially extending cooling bores are provided also through short circuit rings of the rotor which interconnected with a circumferentially extending groove bounded in part by the bendable portions forming the rivet connection with the collar. The outer edges of the inlet opening are disposed at approximately one-half the radial length of the blades. The blades are spaced from the wall forming the inlet opening by a distance corresponding to approximately one-fourth of the radial length of the blades.