Patent ID: 6533537
Filing Date: 2003-03-18
Classification: F04D

Abstract:
An impeller for a circumferential current pump which is provided with a plurality of vane grooves in an outer peripheral side of a synthetic resin disc-like member to be rotated by a motor and is to be rotatably received within a substantially disc-like space formed between a pump casing and a pump cover,wherein an axial hole for engaging with a drive shaft of said motor is formed in a center portion of said disc-like member, said axial hole having an essentially D-shaped cross section and having a straight linear portion serving as a rotation preventing portion for engaging with a corresponding portion of said drive shaft so as to receive a drive force transmitted from said motor, and wherein a pressure adjusting groove open to both side surfaces of said disc-like member is formed at said rotation preventing portion of the axial hole.