Ferrofluidics Corporation

Raoul Casciari

Kuldip Raj

Ronald Moskowitz

Alvan F Chorney

A bearing assembly with an integrated single-stage ferrofluid seal incorporated therein, which assembly comprises: a bearing assembly having an inner and outer race to define a raceway and a plurality of rolling elements within the raceway to permit rotation of the inner and outer races relative to one another; and a single-stage ferrofluid seal within the raceway and positioned adjacent one side of the roller element, and which ferrofluid seal comprises a single pole piece having one end which extends into a close, noncontacting relationship with the surface of the inner and outer races to define a radial gap, ferrofluid in the radial gap to form a seal, an annular permanent magnet secured to and adjacent the single pole piece, and a nonmagnetic permeable housing extending about a portion of the pole piece and the permanent magnet, to divert magnetic flux toward the surfaces of the inner or outer race in which the ferrofluid seal is formed in the radial gap, thereby providing a compact, integrated bearing assembly with a ferrofluid seal.

Bearing assembly with integrated ferrofluid seal

A bearing assembly with an integrated single-stage ferrofluid seal apparatus incorporated therein, which assembly comprises a bearing assembly having an inner and outer race to define a raceway, a plurality of rolling elements retained within the raceway to permit rotation of the inner and outer races relative to one another, and a single-stage ferrofluid seal apparatus within the raceway and adjacent one side of the roller elements and which ferrofluid seal apparatus comprises a single-pole piece which extends into a close, noncontacting relationship with the surface of the inner or the outer race to define a radial gap, ferrofluid in the radial gap to form a ferrofluid seal, and an annular, permanent magnet secured to and adjacent the single-pole piece, the magnet having a generally-L sectional shape and in contact with one side and about one end of the pole piece to provide both a source of magnetic flux and as a magnetically insulating housing for the pole piece.

A single-pole-piece ferrofluid exclusion seal apparatus and exclusion seal system which comprises a single, annular pole piece to surround a shaft element to be sealed, and an annular permanent magnet secured to one surface of the pole piece in a magnetic-flux relationship, the single pole piece having a one end which extends into a close, noncontacting relationship with the surface of the shaft element to be sealed, to define a small radial gap between the surface of the shaft element and the one end of the pole piece, and a ferrofluid positioned within the radial gap, to provide a ferrofluid seal with the shaft element, the ferrofluid comprising a high magnetization-type ferrofluid, with the magnetic flux path of the single-pole-piece ferrofluid seal extending between the shaft, the ferrofluid in the radial gap, the single pole piece in the permanent magnet and the air gap between the magnet and the shaft.

Single-pole-piece ferrofluid seal apparatus and exclusion seal system

A self-activating ferrofluid-seal apparatus for a memory-disc-drive shaft, which seal apparatus comprises a ring magnet and a pair of pole pieces which form a cavity therebetween, a closed loop of a plastic tubular container with ferrofluid positioned within the cavity, and a penetration clamp to penetrate the plastic container prior to installation of the shaft element.

Self-activating ferrofluid seal and method

A self-activating seal is formed by inserting a magnetically permeable shaft into a module which comprises: a magnet, two pole pieces and a magnetic fluid. The module is so constructed that the magnet and pole pieces form a cavity for storing the magnetic fluid until the shaft or similar element is inserted. Upon insertion of the shaft, the magnetic field is altered and the flux path diverted to the small gaps separating the pole pieces and the shaft. The magnetic fluid is drawn to the gas to form hermetic seals.

Growing community of inventors

Bedford, NH, United States of America

Raoul Casciari