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Table I Measured dimensions olasliders tested

HEAD I D h, Dpi h,10 (mnm) (MM) (mmn) (MM) (;Am) (MM) (Jim)

A 0.051PA3 5.552 0.419 1.135 2.718 10.12 2.41

B 0.051A 0.0g;

PAl 5.500 0.381 1.138 2.718 9.81 2.46B 0.102A -0.051

R2 5.537 0.521 0.965 2.515 8.26 2.54B 0.000A -0.064

Y2 5.570 0.533 1.092 2.548 12.02 2.54B -0.051A 0.191

W2 5.512 0.850 0.813 2.261 8.24 2.49B 0.152

11%41 %an4 3100 W3i Sal 11 A 3 3300 150' 845 Sol )76UOAn 7.. 013 A. * 0.A3 0.256 a.". 0.33 O.'l 0.00 0..

Allllt

00os PA SL[D3 (1.136AA.0P053 0

63 0.IS ht0 0.11 gi 6p .2.118 0.71 a., (Pial

%1 7, Loawur 6traN1.@ edge uiearmee, U -36.52 nds ftg.U Pitch wngl werus traiing edge clearneU 36M5 nyc

felti ll 000 6~n 909 !T49 its A 141139 a00 IS"0 Sol 11469 3901.;@ 0.10 0.09 0.33 *.)0 *.Is 11 1.4 0.'4 *,I .31 0.30 0.as It.

feel P00

1001 PN3.30K l01 VAI OLIDOR 'Vk0100)

Fal SLI09D 101ANN3.1

14 IS

PIg LeadWee iralingedge desn. U a 3.2MIS g 10J Pitch angle ves railing edge clerance U a 36.13 Wes

be "m1k concave or conya rlative to the fiat slider. The angle. To minimize this error, the data reduction procedureerowa on the two skates of dhe slider do not necessarily have for determining the surface curvature and the clearaceto be the sme in magnitude or concavity. The last column In profile has been lumped into one step with the use of aTable I shows the inten of the variation In the crown height computer program. The detailed procedure can be found inoew* dmkside bead. It Is alsoousumed that the crown doesnot reference 1101. Basically, the procedure involves the used ofdhmp Im slap or in magnitud within the load range tosted the Method of Least Squares to obtain the best fit of surface(from 10 to 30 lpu-. Finely, there Is no crown across the contour to all of the experimental data (fifinge locations) for a*wih of the skae. given slider. The best fit contour determines the crown heights

ht ko bee foisnd that an inaccurate crown height deter- and the cleatrnce profiles simultaneously. With thisadauloa wil head to an Inaccurate flying profile dete- procedure, a 0.025 pm accuracy can be maintained inomanka, name the wrailing Wilearance and, the pitch determining the trailing edge clearance.

Jbumul of ids o Non TemuwkIg5

Ai 0) 0.7 % G.11 .'I, 009 0. 0 . , .

4WeAICAL

40- 1S1CRICAL l 3190IZOANPIhL *L

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30 At * 210

20- too

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Pfg.il Load versus trailing edge clearancej U -36.13 mis Fig. 14 Pitch angle versus trailing edge clerance U -2L71 W~e

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I (0.2,4 *S 0.7. 9.10

g. 12 Load versus trailing edge cleara e U 36.71 nile Pg.IS Loa verus trailing edge clearan, U a 17.43 Wes

1311 38 33 131 ItI S37 113 A f13 1736 'TO 030 All 0l A

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1*70A* .94 .losolk

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. •. , . . . . . . . . • . . . . . . . . . . . . . . . . .0 O A WS 1 " l ow

Pi 1 Ithanglwe &wersu angedge ocleane, U=2.12nL PWg.IS Pheh anglevaestmllng edge cerneb. U a 17.43mrs

Esperlmental Resmlts and Comparison to Theory two skates on each slider. Experimental load/spacing andpitch anlie/spacing relations are then compared with

In this investigation, the performance of Winchester heads numerical solutions of the modified Reynolds equation. Theof different rail widths - 0.38, 0.51, and 0.89 mm - are details of the numerical solution technique used in this in-studied in both normal ambient air conditions and pure vestiation can be found In reference 110]. Theoreticalhelium environment. The bearin velocities ranged from 17 to predictions are based on actual physical dimensions of the52 m/s with external loads ranging between 8 to 30 grams. sliders and not on the nominal design values. Gas propertiesThe clearance profile (tailing edge clearance, the pitch angle, of air and helium are assumed to be constant throughout theand the roll angle) I determined interferometrically. In this experiments; that is, air and helium viscosities are taken to beinvestigation, extra precautions were taken to prevent the 18.27 and 19.3 Pa-s, respectively, while the mean free path arebearing from roiling. However, some roiling could not be taken to be 0.069 and 0.188 jam, respectively. The ambientavoided due to the differences in the surface contour of the pressure is taken to be 101.4 kPa.

Transactions of the ASME

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sidon lae caai be d nelwsd hf pah of bdrlp nubs

* ef fects had domenatd. the ollpflow theory cures aod Owe401,40"continuum theory Curtes would hav , ac- Id It a Sas shcase fpned by Tweq M. At FWLe, this may seem to be a-to"s; bus If theOAN beSla aMbNOr 1def1neearlier) sd.it wo-ld bwob lowtu se beeINOWMbIS ________________

flax, for the narow ds, th muble b=rlM s it emb Isu .~im ~ *~ Ssooonly onsh ordof 0 o 10.

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