JPH01140071U

JPH01140071U -

Info

Publication number: JPH01140071U
Application number: JP3641988U
Authority: JP
Priority date: 1988-03-22
Filing date: 1988-03-22
Publication date: 1989-09-25

Description

[Brief explanation of the drawing]

第１〜５図はそれぞれこの考案の第１〜５実施
例を示す断面図、第６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の断面図、第７
図および第８図は第６図の要部拡大図で、それぞ
れ磁性流体の保持態様を示す図である。ｃ_１〜ｃ_５……シール部材、２……シヤフト、
６，１０，１１，１２，１３……環状の磁石板、
４，５，１４，１５……ポールピース板、４ａ，
５ａ，１４ａ，１５ａ……筒部、７……磁性流体
、ｍ_１……環状の溝。なお、各図中、同一符号は
同一または相当部分を示す。 1 to 5 are cross-sectional views showing the first to fifth embodiments of this invention, respectively. FIG. 6 is a cross-sectional view of a magnetic disk device using a conventional magnetic fluid seal device.
This figure and FIG. 8 are enlarged views of the main parts of FIG. 6, each showing the manner in which the magnetic fluid is held. c ₁ to c ₅ ... Seal member, 2 ... Shaft,
6, 10, 11, 12, 13... annular magnetic plate,
4, 5, 14, 15...pole piece plate, 4a,
5a, 14a, 15a...cylindrical portion, 7...magnetic fluid, _m1 ... annular groove. In each figure, the same reference numerals indicate the same or corresponding parts.

Claims

[Claims for Utility Model Registration] (1) A first annular pole piece plate having a cylindrical portion on its periphery and a second pole piece plate having no cylindrical portion on its periphery on both end faces of an annular magnet plate. an annular seal member formed by coaxially fixing the
A rotating body made of a magnetic material that rotates coaxially and relative to the sealing member with a gap between the circumferential surfaces of the two pole piece plates, and a magnetic fluid held in the gap by the magnetic force of a magnet plate. and the sealing member has an opening in its peripheral surface at the gap between the cylindrical portion of the first pole piece plate and the second pole piece plate, and has a width equivalent to the gap, and has a wall surface formed in the gap between the cylindrical portion of the first pole piece plate and the second pole piece plate. A magnetic fluid sealing device characterized by having an annular groove formed by an annular magnet plate and a second pole piece plate. (2) At both end surfaces of the annular magnet plate, a first annular pole piece plate and an outer ( a second pole piece plate having the same diameter as the first pole piece plate and having no cylindrical portion on its peripheral edge; an annular non-magnetic material fitted between the part and the circumferential surface of the magnet plate, and a magnetic body coaxially rotating relative to the sealing member with a gap between the circumferential surfaces of the two pole piece plates. and a magnetic fluid held in the gap by the magnetic force of a magnet plate, and the seal member has a cylindrical portion of the first pole piece plate and a second pole piece on its peripheral surface. The gap between the plates is an opening, and the width is equivalent to the gap, and
A magnetic fluid sealing device characterized in that the wall surface has an annular groove formed by an annular magnet plate, a second ball piece plate, and an annular non-magnetic material. (3) The sealing member has an opening on its peripheral surface that corresponds to the gap between the cylindrical portion of the first pole piece plate and the second pole piece plate, and has a width equivalent to the gap, and has a wall surface that corresponds to the width of the second pole piece plate. 3. The magnetic fluid sealing device according to claim 2, further comprising an annular groove formed by a pole piece plate and an annular non-magnetic material. (4) A first annular pole piece plate having a first cylindrical portion on its periphery and a second annular pole piece plate having a second cylindrical portion on its periphery are attached to both end surfaces of the annular magnet plate; a rotating body made of a magnetic material that coaxially rotates relative to the sealing member with a gap between an annular sealing member that is coaxially fixed to each other and the circumferential surface of the two pole piece plates; The sealing member is made of a magnetic fluid held in the gap by the magnetic force of a magnet plate, and the sealing member has an opening on its peripheral surface in the gap between the first cylindrical part and the second cylindrical part, and A magnetic fluid sealing device characterized by having an annular groove having a width corresponding to the gap and whose wall surface is formed of an annular magnet plate. (5) An annular first pole piece plate having an outer (inner) diameter larger (smaller) than the outer (inner) diameter of the magnet plate and having a first cylindrical portion on the periphery on both end surfaces of the annular magnet plate. and an annular second ball piece having the same outer (inner) diameter as the first ball piece and having a second cylindrical portion on the periphery.
an annular sealing member formed by coaxially fixing the pole piece plates, respectively; and an annular non-magnetic seal member fitted between the first and second cylindrical parts and the circumferential surface of the magnet plate. a rotating body made of a magnetic material that rotates coaxially and relative to the sealing member with a gap between the material and the circumferential surfaces of the two pole piece plates; and a magnetic body held in the gap by the magnetic force of a magnet plate. The sealing member has a circumferential surface formed of a gap between the first cylindrical portion and the second cylindrical portion as an opening, a width corresponding to the gap, and a wall surface formed into an annular shape. A magnetic fluid sealing device characterized by having an annular groove formed of a non-magnetic material.