Large-amplitude low-frequency vibrator
US5111697A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 12, 1991 |
| Grant date | May 12, 1992 |
| Priority date | — |
| Expiry date | Feb 12, 2011 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB06B1/045
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A vibrator acting in a low frequency vibration domain, for fixing to and applying low frequency vibrations on a frame in a first predetermined direction along an axis X'X. The vibrator comprises: a first structure having cylindrical pole pieces cylindrical about an axis coaxial to said predetermined direction X'X and provided at their peripheries with coils, and at least one means for creating a magnetic field for causing a magnetic flux to be established between the cylindrical pole pieces; a second structure comprising a cylindrical ferromagnetic mass coaxial about the axis X'X and having cylindrical pole pieces whose peripheries are situated facing respective ones of the coils, and enabling magnetic flux to be established through the ferromagnetic mass; radial active magnetic bearings for holding the second structure radially relative to the first structure without making contact therewith; at least one detector for detecting vibrations along the axis X'X; and circuits for servo-controlling the current flowing in the coils as a function of signals delivered at least by the detector.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.