Patent ID: 8272838
Filing Date: 2012-09-25
Classification: F04D

Abstract:
1. An impeller, comprising: an impeller body which rotates about a rotation axis; and a vane and an outlet which are provided at the impeller body, wherein the impeller body receives force asymmetric with respect to the rotation axis in driving and rotation in a fluid in a manner that radially inward fluid force, which is generated due to arrangement of the vane, acts on a predetermined point in a peripheral direction, a hollow space formed in the impeller body and completely surrounded by circumferential wall portions having no openings, at least part of the hollow space being opposite to the outlet that fills with fluid such that when the impeller body is driven and rotated in the fluid centrifugal force acting on the fluid filled space cancels the fluid force acting on the impeller body thereby balancing the impeller about its rotation axis when the impeller body is driven and rotated in the fluid, and in an evacuated state in which the fluid is evacuated from the filled space, the impeller is balanced about its rotation axis so as to have static balance in a resting state and dynamic balance in a rotating state when the impeller body is driven and rotated in air.