Mutual active cancellation of fan noise and vibration
US7282873B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 16, 2004 |
| Grant date | Oct 16, 2007 |
| Priority date | — |
| Expiry date | Dec 31, 2025 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF04D25/166
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A multi-fan apparatus and method incorporates mutual active cancellation of fan noise and/or vibrations. The multi-fan apparatus includes two or more fans circuits, each comprising a fan, a fan speed controller and a separate tachometer, and a fan phase controller. The phase controller is connected to at least one fan speed controller and to each tachometer. Each fan's speed is independently and dynamically maintained at the same set speed by the fan speed controllers using an independent control loops. A noise and/or vibration cancellation phase difference between fans is determined in order to achieve destructive interference of pressure waves and, thus, noise and/or vibration reduction, in pre-determined region of a system incorporating the multi-fan apparatus. The phase controller establishes and maintains this cancellation phase difference between the fans based upon feedback from the tachometers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.