SCHIJFOPNEMER MET EEN AANDRIJVING MET BEHULP VAN EEN GELIJKSTROOMMOTOR ZONDER BORSTELS.

摘要

A drive and improved ground spindle assembly for a disc recorder and particularly one using a rigid disc having a direct coupled spindle shaft arrangement which includes a disc support platform mounted concentrically at one end of the spindle shaft and a DC motor attached to the other end of the spindle shaft is disclosed. The drive spindle assembly includes a disc support platform incorporating air impelling vanes on one side and bleed orifaces extending through the disc support platform so that air is drawn along the spindle assembly to cool it and then impelled outwardly over both sides of the recording disc to aerodynamically fly the recording heads on a thin film of air moving radially over the surface of the disc. The motor is a brushless DC type motor having a permanent magnet rotor driven by a rotating magnetic field. Provision of the brushless DC motor and unique ground and sealing means eliminate airborne contaminants that impair the operation of prior art disc recorders of this type.