Blower fan and working machine provided with the same
US7744342B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 6, 2005 |
| Grant date | Jun 29, 2010 |
| Priority date | — |
| Expiry date | Aug 1, 2027 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF04D29/665
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A blower fan includes: an impeller having a predetermined number of blades; a fan casing having an air-intake port disposed to face a central portion of base of the impeller and eccentrically housing the blower fan and defining a spiral scroll passageway between an inner wall thereof and an external circumference of the impeller, the spiral scroll passageway having an inlet portion constituting a narrow nose portion and an outlet portion constituting a wide discharge port; and a driving source for rotating the impeller. In order to minimize the noise to be released from the nose portion, the blower fan further includes a sound-reflecting means which is disposed to cover a portion of the air inlet port at a location spaced away from the nose portion by a distance corresponding to ½ of wavelength of noise in an emanating direction of noise.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.