JP3048962U - Inertia damper using magnetic fluid - Google Patents

Abstract

(57) [Problem] To provide an inertia damper that does not lock even when the operation speeds up. SOLUTION: In an inertia damper utilizing the magnetic properties and viscosity of a magnetic fluid, a lubricating powdery inert substance having a specific gravity of approximately the same level is mixed into a magnetic fluid (4). (1) is a rotating shaft,
(2) is a mass and (3) is a permanent magnet.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to an improvement of an inertia damper (vibration damping device) used for suppressing vibration of a servomotor or the like and improving high-speed performance.

[0002]

[Prior art]

 Conventional inertia dampers are of the sealed type and the open type, but both of them prevent the mechanical locking of each other by the floating effect of the magnetic fluid inserted between the mass or housing and the permanent magnet. However, locking may occur when the operation speeds up. Locking is also likely to occur depending on the operating position.

[0003]

[Problems to be solved by the invention]

 Provided is an inertia damper that does not lock even when the operation speeds up.

[0004]

[Means for Solving the Problems]

 The present invention is directed to an inertia damper utilizing the magnetic properties and viscosity of a magnetic fluid, wherein a magnetic fluid is mixed with a lubricating powdery inert substance having a specific gravity substantially equal to that of the magnetic fluid. Is an inertia damper.

As the powdered inert substance, a fluororesin or ceramic having a specific gravity similar to that of a magnetic fluid is preferably used. Such a powder, when mixed with a magnetic fluid, has approximately the same specific gravity, and thus uniformly mixes with the magnetic fluid in a non-magnetic field. When this is placed in a magnetic field, the apparent specific gravity at the place where the magnetic field is large becomes large, so that the powdered inert material moves to the place where the magnetic field is small. For this reason, the lock prevention effect is exerted at that portion. The amount of the powdered inert substance mixed with the magnetic fluid is preferably 3 to 15%. If it is less than 3%, the anti-locking effect is not sufficient, and if it exceeds 15%, the magnetic fluid cannot exhibit its magnetic properties and viscosity sufficiently, which hinders the floating effect, which is not preferable.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows an example of an open type inertia damper, wherein 1 is a rotating shaft, 2 is a mass, and 3 is a permanent magnet. A magnetic fluid 4 is interposed between the mass 2 and the permanent magnet 3. The magnetic fluid 4 contains 10% of lubricating fluororesin powder. When the magnets are arranged horizontally as shown in FIG. 1, the magnetic field of the permanent magnet 3 is large in the part B and has a levitation effect. 3 moves downward by gravity, and the probability that the mass 2 and the permanent magnet 3 are mechanically locked increases. That is, since the apparent specific gravity of the part B becomes large and the apparent specific gravity of the part A becomes small, the fluororesin powder gathers in the part A. Since the fluororesin powder has a lubricating effect, locking is prevented in the portion A where a large amount of the powder is collected. Similar effects can be obtained by using ceramic powder instead of fluororesin powder.

[0008]

[Effect of the invention]

 According to the present invention, locking of the inertia damper can be prevented by a very simple means of adding a powdery inert substance to the magnetic fluid, and the characteristics of the magnetic fluid are not largely changed. Therefore, it can be applied to dust-proof seals and vacuum seals, including suppression of vibration and improvement of high-speed performance of servomotors and the like.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 rotating shaft 2 mass 3 permanent magnet 4 magnetic fluid

Claims (2)

[Utility model registration claims] 1. An inertia damper utilizing the magnetic properties and viscosity of a magnetic fluid, wherein a magnetic fluid is prepared by mixing a lubricating powdery inert substance having a specific gravity substantially equal to the magnetic fluid. Inertia damper used. 2. The inertia damper using a magnetic fluid according to claim 1, wherein the powdery inert substance is a fluororesin or ceramic having a specific gravity similar to that of the magnetic fluid, and the amount thereof is 3 to 15%.