Claims
- 1. A damper device for damping oscilllations of a rotationally driven shaft, comprising: a boss section connectable during use of the damper device to a rotationally driven axially extending shaft so that the boss section is rotationally driven by the shaft; a ring-shaped magnet carried by and extending radially outwardly of and circumferentially around the boss section; a mass inertia section encircling the boss section and the magnet, the mass inertia section having an annular concave portion facing the boss section, the magnet extending radially outwardly into the concavity of the concave portion and being spaced from the surface of the concave portion to define therebetween an annular gap; a viscous magnetic fluid disposed in the annular gap for imparting a viscous resistance to rotation of the mass inertia section when the boss section is rotationally driven, the magnetic fluid being confined within the annular gap by the magnetic field created by the ring-shaped magnet; mechanical bearing means rotatably and mechanically supporting the mass inertia section directly on the boss section, the mechanical bearing means comprising a pair of roller bearings interposed between the boss section and mass inertia section on either side of the ring-shaped magnet; a pair of annular cover plates connected to opposed sides of the mass inertia section outwardly of the respective roller bearings, each cover plate carrying a ring-shaped magnet having an inner peripheral surface which is radially spaced from another peripheral surface of the boss section; and viscous magnetic fluid confined in the spaces between the inner and outer peripheral surfaces by the magnetic fields created by the ring shaped magnets.
- 2. A damper device according to claim 1; wherein the cover plates are positioned to hold the respective roller bearings in place between the boss and mass inertia section.
- 3. A damper device according to claim 1; wherein the cover plates comprise annular cover plates having a center opening through which extends the boss section.
- 4. A damper device according to claim 1; wherein the roller bearings comprise ball bearings.
Priority Claims (1)
Number |
Date |
Country |
Kind |
62-135671[U] |
Sep 1987 |
JPX |
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RELATED APPLICATIONS
This is a division of application Ser. No. 569,374 filed Aug. 13, 1990, now U.S. Pat. No. 5,081,882, which is a continuation of application Ser. No. 234,816 filed Aug. 22, 1988, now abandoned.
US Referenced Citations (9)
Foreign Referenced Citations (2)
Number |
Date |
Country |
1956759 |
May 1971 |
DEX |
62673 |
Mar 1986 |
JPX |
Divisions (1)
|
Number |
Date |
Country |
Parent |
569374 |
Aug 1990 |
|
Continuations (1)
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Number |
Date |
Country |
Parent |
234816 |
Aug 1988 |
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