Multi-blades fan device
US5511939A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 27, 1994 |
| Grant date | Apr 30, 1996 |
| Priority date | — |
| Expiry date | Jul 27, 2014 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF04D29/4206
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A multi-blade fan having a fan assembly including a bottom plate and a plurality of circumferentially spaced blades and a casing for the fan assembly therein having an outlet duct extending therefrom for discharge of the air flows. The fan assembly includes an annular shroud connected to the axial ends of the blades remote from the bottom plate. The casing includes a bottom wall for rotatably connecting the fan assembly, a top wall for defining an air inlet for axially introducing the air into the casing, and a tubular wall connecting the bottom and top walls. The top wall of the casing adjacent to the inlet opening forms an annular projection having a bell cross sectional shape opened inwardly so that an axial end of the shroud extends thereto. The bell cross section portion radially extends to a portion that is inclined downwardly in the outward direction, which faces the shroud so that a small gap extending radially is created. The top wall or bottom wall of the casing at its radially outer portion can be downwardly inclined. The tubular wall of the casing can also be inclined so that the bottom end of the tubular wall is flared radially outward from its center.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.