JPH01118257U

JPH01118257U -

Info

Publication number: JPH01118257U
Application number: JP1355488U
Authority: JP
Priority date: 1988-02-05
Filing date: 1988-02-05
Publication date: 1989-08-10

Description

【図面の簡単な説明】[Brief explanation of the drawing]

第１図はこの考案の実施例の要部断面図、第２
図は他の実施例の要部断面図、第３図は従来の磁
性流体シール装置を使用した磁気デイスク装置、
第４図は第３図の要部拡大図、第５図は第４図の
要部拡大図である。１……ハウジング、２……シヤフト、３……軸
受、３ａ……内輪、３ｂ……外輪、７……磁性流
体、Ｃ_１……シール部材、１４，１５……環状の
ポールピース、１６……環状の磁石、ｍ_１……溝
。 Figure 1 is a sectional view of the main part of an embodiment of this invention, Figure 2
The figure is a sectional view of a main part of another embodiment, and FIG. 3 is a magnetic disk device using a conventional magnetic fluid sealing device.
4 is an enlarged view of the main part of FIG. 3, and FIG. 5 is an enlarged view of the main part of FIG. 4. DESCRIPTION OF SYMBOLS 1... Housing, 2... Shaft, 3... Bearing, 3a... Inner ring, 3b... Outer ring, 7... Magnetic fluid, _C1 ... Seal member, 14, 15... Annular pole piece, 16... ...Annular magnet, m ₁ ...groove.

Claims

【実用新案登録請求の範囲】[Scope of utility model registration request]

環状の磁石の両端面に２つの環状のポールピー
スを同軸的に固着して形成したシール部材と、前
記２つのポールピースとの間に隙間をおいて前記
シール部材と同軸的に相対回転する磁性体よりな
る回転体と、前記隙間に磁石の磁力で保持した磁
性流体とよりなり、かつ前記磁性流体を介して回
転体と対向するシール部材の周縁部の少なくとも
一部に、２つの環状のポールピースの内側面と環
状の磁石の周面とで形成される環状の溝を有する
シール装置において、前記溝の少なくとも一部を
構成する２つのポールピースの内側面間の最大距
離を、前記溝から離れた部分の環状の磁石の厚さ
より小さくしたことを特徴とする磁性流体シール
装置。 A sealing member formed by coaxially fixing two annular pole pieces to both end faces of an annular magnet, and a magnetism that coaxially rotates relative to the sealing member with a gap between the two pole pieces. a sealing member comprising a rotating body consisting of a rotary body and a magnetic fluid held in the gap by the magnetic force of a magnet, and facing the rotating body through the magnetic fluid; In a sealing device having an annular groove formed by an inner surface of a piece and a circumferential surface of an annular magnet, the maximum distance between the inner surfaces of two pole pieces constituting at least a part of the groove is determined from the groove. A magnetic fluid sealing device characterized in that the thickness is smaller than that of an annular magnet at a separate portion.