Compact long-life magnetic fluid seal
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
May 16, 1989
Grant Date -
N/A
app pub date -
Jun 29, 1987
filing date -
Jun 29, 1987
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
A compact long-life magnetic fluid seal for sealing between a housing and a magnetically permeable rotating shaft includes an annular magnet having a closely-spaced, noncontacting relationship with the shaft to define a first gap and an annular pole piece axially abutting the magnet and having a closely-spaced, noncontacting relationship with the shaft to define a second gap. The first gap has a slightly larger radial dimension than the second gap, and the first and second gaps together define an elongated annular space for retention of a magnetic fluid. The outer edges of the pole piece and magnet inner surfaces can be rounded to limit splashing of the magnetic fliud. In another embodiment, a magnetic fluid seal includes first and second pole pieces axially abutting opposite ends of an annular magnet. The magnet has a slightly larger inside diameter than either of the pole pieces. The pole pieces and the magnet together define an elongated annular gap for retention of magnetic fluid. The seal structure permits introduction of a relatively large volume of magnetic fluid, thereby extending the seal life, while maintaining a short axial dimension.
First Claim
Family
International Classification(s)
Cited Art Landscape
Patent Citation Ranking
Recipient Email Address
Recipient Email Address
Comment
Recipient Email Address
Add to Portfolio(s)
To add this patent to one, or more, of your portfolios, simply click the add button.
This Patent is in these Portfolios:
Add to additional portfolios:
Last Refreshed On:
Changes done successfully