JPH0318666U

JPH0318666U -

Info

Publication number: JPH0318666U
Application number: JP7976789U
Authority: JP
Priority date: 1989-07-05
Filing date: 1989-07-05
Publication date: 1991-02-25
Anticipated expiration: 2004-07-05
Also published as: JPH0756621Y2

Description

[Brief explanation of drawings]

第１図は本考案の一実施例を示す断面正面図、
第２図は要部拡大断面図、第３図と第４図は夫々
別の実施例の作用説明を兼ねた要部断面図、第５
図〜第８図は夫々さらに別の実施例を示す要部拡
大断面図、第９図は第２図の要部拡大図である。７……ハブ、８……嵌合孔部、１０……磁性流
体シール、１１……リング板状マグネツト、１２
……ポールピース、１３……接触平板部、１４…
…外周縁、１５……外周縁、１６……嵌着用筒部
、１８……熱膨張吸収用間〓部、２０……磁性流
体、Ｄ_１，Ｄ_２……嵌合孔部の直径、Ｄ_３，Ｄ_４……嵌着用筒部の直径。 FIG. 1 is a cross-sectional front view showing an embodiment of the present invention;
FIG. 2 is an enlarged sectional view of the main part, FIGS.
8 to 8 are enlarged sectional views of main parts showing still further embodiments, and FIG. 9 is an enlarged view of main parts of FIG. 2. 7... Hub, 8... Fitting hole portion, 10... Magnetic fluid seal, 11... Ring plate magnet, 12
...Pole piece, 13...Contact flat plate part, 14...
...Outer peripheral edge, 15...Outer peripheral edge, 16...Cylinder part for fitting, 18...Interval part for absorbing thermal expansion, 20...Magnetic fluid, _D1 , _D2 ...Diameter of fitting hole, D ₃ , D ₄ ...The diameter of the fitting cylinder.

Claims

[Scope of claims for utility model registration] 1. Fitting hole 8 of hub 7 or bracket cylindrical portion, etc.
In a spindle motor in which a magnetic fluid seal 10 is fitted, the magnetic fluid seal 1 is composed of a ring plate-shaped magnet 11, a pole piece 12 made of a magnetic material overlaid thereon, and a magnetic fluid 20.
The pole piece 12 of 0 is connected to the magnet 11.
has a contact flat plate portion 13 superimposed on the contact plate portion 13, and
A fitting device in which the outer circumferential edge 14 of the contact flat plate portion 13 extends radially outward beyond the outer circumferential edge 15 of the magnet 11, and the outer circumferential edge 14 is bent inward to fit into the fitting hole portion 8. A spindle motor characterized in that it is configured with a cylindrical portion 16 arranged in series. 2. A spindle motor in which a magnetic fluid seal 10 is fitted into the fitting hole 8 of the hub 7 is composed of a ring plate magnet 11, a pole piece 12 made of a magnetic material overlaid on the ring plate magnet 11, and a magnetic fluid 20. The above magnetic fluid seal 1
The pole piece 12 of 0 is connected to the magnet 11.
has a contact flat plate portion 13 superimposed on the contact plate portion 13, and
A fitting device in which the outer circumferential edge 14 of the contact flat plate portion 13 extends beyond the outer circumferential edge 15 of the magnet 11 toward the outer diameter side, and the outer circumferential edge 14 is bent inward to fit into the fitting hole portion 8. The cylindrical portion 16 is connected, and further,
A spindle motor characterized in that a thermal expansion absorbing spacer part 18 is formed between the axially outer side of the fitting cylinder part 16 and the fitting hole part 8. 3. The diameter D1 of the fitting hole 8 corresponding to the axially outer side of the fitting cylinder 16 is set larger than the diameter _D2 of the fitting hole ₈ corresponding to the axially inner side to absorb the thermal expansion. 3. The spindle motor according to claim 2, further comprising a spacer portion 18. 4 Axial outer diameter D of the fitting cylinder portion 16 ₃ is set smaller than the axially inner diameter _D4 ,
3. The spindle motor according to claim 2, further comprising the thermal expansion absorbing spacer portion 18.