Method and apparatus for measurement and control of magnetic particle concentration in a magnetorheological fluid
US8896293B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 13, 2011 |
| Grant date | Nov 25, 2014 |
| Priority date | — |
| Expiry date | Feb 25, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/74
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system for sensing and controlling concentration of magnetic particles in magnetorheological fluid comprising a wire coil and an AC voltage generator that, when energized, creates a magnetic flux field including a fringing field. When the fringing field extends through the magnetorheological fluid, the impedance in the circuit is proportional to the concentration of magnetic particles. A reference wire coil identical to the sensing wire coil is connected therewith. A demodulator is connected to each of the coils sends an impedance difference signal to a feedback controller connected to controllable dispensing apparatus for adding a calculated amount of replenishing fluid to the magnetorheological fluid. The system may be incorporated into an integrated fluid management module having apparatus for receiving and replenishing spent magnetorheological fluid and a sensor system in accordance with the present invention for use in a magnetorheological finishing system having a carrier wheel.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.