Passive magnetorheological fluid device with excursion dependent characteristic
US5947238A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 5, 1997 |
| Grant date | Sep 7, 1999 |
| Priority date | — |
| Expiry date | Mar 5, 2017 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16F9/535
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A magnetorheological fluid device which exhibits excursion (stroke or rotation) dependent resistance (force or torque) which is obtained passively. Linear and rotary embodiments are described. The devices described herein include various ways for passively varying magnetic circuit reluctance to accomplish the stroke or rotation dependent characteristic. The devices include a first component with an internal cavity, a second component received in the cavity and moveable relative to the first component, a working zone created between the first and second component, a magnetorheological fluid contained therein, at least one permanent magnet for producing a magnetic field, a magnetic circuit for directing a magnetic flux created by the permanent magnet toward the magnetorheological fluid in the working zone, and passively varying a magnetic circuit reluctance (such as by changing a thickness of a magnetic return, by changing a gap thickness, by changing the material reluctance, by interacting multiple magnetic fields, or combinations thereof) as a function of excursion. This changes the magnetic field strength acting upon the MR fluid in the working zone and produces a force/torque whi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.