Centrifuge driven by a hysteresis motor - with the stator cooled by an external ring with fins connected to a cooled footplate

A centrifuge (esp. ultracentrifuges) has a footplate and a cylindrical bowl supported by a bearing on the plate. It is driven by a hysteresis motor with a stator fixed to the footplate and the rotor integral with the bottom of the bowl. The stator is enclosed in a plastic housing with radially extending windings and pole shoes. The plastic housing is surrounded by a metal cooling ring with ribs extending into the plastic between the stator windings. The ring is joined to the footplate which is cooled. The efficient cooling of the stator prevents heating of the bowl and production of vapours by the stator housing when the equipment operates under vacuum.