The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 22, 1991
Filed:
Jan. 18, 1990
Ebara Corporation, Tokyo, JP;
Abstract
A pump impeller manufactured by press forming of steel plate and comprising a boss formed with a central bore for connecting the boss to a main shaft of the pump through key and key way engagement, and a main shroud fixed to the boss is disclosed. The impeller is characterized in that the boss is formed with a polygonal portion on the periphery of the boss and the main shroud is formed at central portion thereof with a polygonal recess fitting to the polygonal portion of the boss. A retainer plate is mounted on the boss at an end portion thereof opposite to an end portion from which the main shroud is fitted to the boss and is connected by welding to the main shroud. Thereby, since the power is transmitted from the boss to the main shroud through polygonal surfaces, no substantial stress concentration occurs at the power transmitting area.