Ventilation fan
US8678785B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 30, 2010 |
| Grant date | Mar 25, 2014 |
| Priority date | — |
| Expiry date | Apr 25, 2032 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF04D25/0613
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A ventilation fan includes a rotor holder rotating around a rotation axis, an impeller cup including a plurality of blades provided on an outer circumference thereof, and a base portion arranged to rotatably support the rotor holder through a bearing portion. The base portion includes an outer circumferential wall extending upwards in an axial direction from an outer circumferential edge portion thereof. A gap defining a labyrinth structure is provided between an upper end portion of the outer circumferential wall of the base portion and a lower end portion of an outer circumferential portion of the impeller cup. A lower end portion of a cylindrical portion is located axially lower than the upper end portion of the outer circumferential wall of the base portion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.