Stator of helical screw pump - has spiral straps to compress elastic stator threads to compensate for wear

摘要

The pump has a bearing assembly driving an overhung helical screw rotor through universal couplings. The rotor turns eccentrically in a stator which has an elastic material with a two start thread held in a steel cylinder. The steel cylinder has two helical slots each of which is bridged by a strong axial bar. Helical steel strips are placed in the slots and have end lugs which are bolted to fixed lugs on the ends of the steel cylinder. When the bolts are tightened the stator cylinder is compressed radially and in turn compresses the elastic inner material of the stator thus taking up excess clearance which has been caused by wear between the rotor and stator.