Volute pump

Patent metadata

Field	Value
Publication number	US-2018051718-A1
Application number	US-201615560909-A
Country	US
Kind code	A1
Filing date	Mar 24, 2016
Priority date	Mar 27, 2015
Publication date	Feb 22, 2018
Grant date	—

Abstract

A volute pump for delivering a liquid containing fibrous substances. The volute pump includes an impeller ( 1 ) rotatable together with a rotational shaft ( 11 ), and an impeller casing ( 5 ) having a suction port ( 3 ) and a volute chamber ( 7 ). A groove ( 18 ), extending from the suction port ( 3 ) to the volute chamber ( 7 ), is formed in an inner surface of the impeller casing ( 5 ). The impeller ( 1 ) includes a hub ( 13 ) to which the rotational shaft ( 11 ) is fixed, and a sweep-back vane ( 2 ) extending helically from the hub ( 13 ). The sweep-back vane ( 2 ) includes a leading edge portion ( 2 a ) extending helically from the hub ( 13 ), and a trailing edge portion ( 2 b ) extending helically from the leading edge portion ( 2 a ). The leading edge portion ( 2 a ) has a front-side curved surface ( 2 e ) extending from an inner end ( 2 c ) to an outer end ( 2 d ) of the leading edge portion ( 2 a ).

First claim

What is claimed is:

1 . A volute pump comprising:
an impeller rotatable together with a rotational shaft; and an impeller casing having a suction port and a volute chamber; wherein a groove, extending from the suction port to the volute chamber, is formed in an inner surface of the impeller casing, the impeller includes
a hub to which the rotational shaft is fixed, and
a sweep-back vane extending helically from the hub,
the sweep-back vane includes
a leading edge portion extending helically from the hub, and
a trailing edge portion extending helically from the leading edge portion, and
the leading edge portion has a front-side curved surface extending from an inner end to an outer end of the leading edge portion.

2 . The volute pump according to claim 1 , wherein a ratio of a radius of curvature of the front-side curved surface to a thickness of the leading edge portion is in a range of 1/7 to 1/2.

3 . The volute pump according to claim 2 , wherein the ratio of the radius of curvature of the front-side curved surface to the thickness of the leading edge portion is in a range of 1/4 to 1/2.

4 . The volute pump according to claim 2 , wherein the ratio of the radius of curvature of the front-side curved surface to the thickness of the leading edge portion gradually increases according to a distance from the hub.

5 . The volute pump according to claim 1 , wherein the leading edge portion has a back-side curved surface extending from the inner end to the outer end of the leading edge portion.

6 . The volute pump according to claim 1 , wherein the trailing edge portion has a front-side angular portion and a back-side angular portion extending from a starting end to a terminal end of the trailing edge portion connected with the outer end of the leading edge portion.

Assignees

• Ebara Corp

Inventors

• Kawai Masahito
• Sakacho Hiromi
• Obuchi Masashi
• Uchida Hiroshi
• Isono Miho
• Tokairin Kenta

Classifications

• F04D7/045

  with means for comminuting, mixing stirring or otherwise treating · CPC title

• F04D29/708 Primary

  specially for liquid pumps · CPC title

• F05D2250/71

  curved · CPC title

• F04D7/04

  the fluids being viscous or non-homogenous · CPC title

• F05D2240/303

  related to the leading edge of a rotor blade · CPC title