A.01.30_Amendment_0001_Spec_Revision.pdf

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GENERATOR THRUST BEARING TOLERANCE SHEETS

TOLERANCES FOR THRUST BEARING RUNNER AND BASE PLATE*

1. RUNNING FACE AND BACKSIDE OF RUNNER & BASE PLATE

A. CIRCUMFERENTIAL RUNOUT

A DIAL INDICATOR ACCURATE TO THE 0.0001 INCHES SHALL BE MOUNTED IN

THE MACHINING HEAD WITH THE STEM OF THE INDICATOR RESTING ON THE

RUNNING FACE, BACKSIDE OF THE RUNNER OR BASE PLATE. THE RUNNER OR

BASE PLATE SHALL BE SLOWLY ROTATED AND THE READINGS OBSERVED.

VARIATIONS SHALL NOT BE MORE THAN 0.0003 INCHES OVER ONE COMPLETE

REVOLUTION OF THE RUNNER OR BASE PLATE. THIS CHECK SHALL BE MADE

NEAR THE I.D., CENTER, AND O.D. OF THE FACE WIDTH.

B. RADIAL FLATNESS

A RADIAL CHECK, BY LAYING A STRAIGHT EDGE ACROSS THE RUNNING AND

BACKSIDE FACES OF THE RUNNER OR BASE PLATE SURFACE, SHALL BE MADE

TO VERIFY THE FLATNESS, SEE FIGURE 1. THE FACES AND SURFACE SHALL

BE TRUE WITHIN 0.0005 INCHES WHEN CHECKED IN THIS MANNER.

ALTERNATE MEASURING METHODS SHALL BE SUBMITTED FOR APPROVAL.

C. DISH FLATNESS

TO CHECK FOR DISH FLATNESS, LAY A STRAIGHT EDGE ALONG A CHORD LINE

ON THE RUNNING AND BACKSIDE FACES OF THE RUNNER OR BASE PLATE

SURFACE, SEE FIGURE 2. THE FACES AND SURFACE SHALL BE FLAT WITHIN

0.0015 INCHES. A CONCAVE RUNNER SHAPE IS ACCEPTABLE, I.E. WITH

THE LOW POINT TOWARD THE CENTER OF THE RUNNER. A CONVEX RUNNER

SHAPE (O.D. SURFACE EDGE IS LOWER THAN I.D. SURFACE EDGE) IS NOT

ACCEPTABLE AND WILL BE REJECTED.

∗ BASE PLATE REFERS TO EITHER A SEPARATE PLATE OR THE BORING MILL’S

MACHINING TABLE.

Radial Flatness Check Dish Flatness Check

2. NOT USED

3. PARALLELISM

THE RUNNING SURFACE SHALL BE PARALLEL WITH THE BACKSIDE OF THE

RUNNER WITHIN 0.002 INCHES IN THE RADIAL DIRECTION AND 0.0005

INCHES IN THE CIRCUMFERENTIAL DIRECTION.

4. SURFACE FINISH

THE JOURNAL (RUNNING) SURFACE AND BACKSIDE OF THE RUNNER SHALL

HAVE A FINISH OF 10 AND 16 MICROINCHES OR BETTER, RESPECTIVELY.

THE SURFACES OF THE I.D. AND O.D. SHALL HAVE FINISHES OF 125 AND

63 MICROINCHES OR BETTER, RESPECTIVELY. THE SURFACES SHALL BE

CHECKED WITH A PROFILOMETER.

5. SPLIT LINE CONTACT

THE RUNNER SPLIT LINES (SPLIT LINES DEFINED AS THE JOINTING POINT

OF TWO RUNNER HALVES) SHALL NOT BE ABLE TO ACCEPT A 0.001 INCH

FEELER GAUGE. THE STEP (OFFSET) AT THE SPLIT LINES SURFACE SHALL

BE LESS THAN 0.0001 INCH. MEASUREMENTS SHALL BE MADE FROM BOTH

THE RUNNING FACE AND BACKSIDE.

6. SPLIT LINE FACE CONTACT

THE CONTACT AREA OF THE MATING SURFACES OF THE RUNNER HALVES AT

THE SPLITS SHALL BE DETERMINED USING A BLUING PROCESS. THE

CONTACT SHALL BE A MINIMUM OF 75 PERCENT OF THE TOTAL AREA AND BE

EVENLY DISTRIBUTED ON BOTH SIDES OF THE RADIAL KEYWAYS. THE AREAS

SHALL BE PHOTOGRAPHED INCLUDING DIMENSIONS, AND THE PERCENT

CONTACT AREA FOR EACH SIDE CALCULATED.

G4EDHCMP

Line

TOLERANCES FOR STATIONARY THRUST BEARING SHOE SEGMENTS

ENTIRE SET MACHINED SIMULTANEOUSLY IN ONE SETUP

1. CIRCUMFERNTIAL RUNOUT

A DIAL INDICATOR ACCURATE TO 0.0001 INCHES SHALL BE MOUNTED IN THE

HEAD OF THE MACHINE TOOL WITH THE STEM OF THE INDICATOR RESTING ON

AN INDIVIDUAL SHOE’S BABBITTED SURFACE. THE MACHINE TABLE SHALL

THEN BE SLOWLY ROTATED AND READINGS TAKEN WHEN THE STEM IS ON EACH

INDIVIDUAL SHOE. VARIATIONS ON AN INDIVIDUAL SHOE AND AMONG THE

SET OF SHOES SHALL NOT BE MORE THAN 0.0005 INCHES OVER ONE

COMPLETE REVOLUTION OF THE TABLE. THIS CHECK SHALL BE MADE NEAR

THE I.D., CENTER, AND O.D. OF THE SHOES.

2. DISH FLATNESS

INDIVIDUAL SHOES SHALL BE CHECKED FOR FLATNESS USING A PLANEKATOR.

THE BABBITTED SURFACE SHALL BE FLAT OR CONCAVE WITH THE MAXIMUM

LOW SPOT IN THE CENTER OF THE SHOE. THE LOW SPOT SHALL NOT EXCEED

0.0015 INCHES. THIS LOW SPOT SHALL NOT INCLUDE OIL HOLES,

THREADED HOLES, OR OIL GROOVES OR POCKETS. A BABBITTED SURFACE

THAT IS CONVEX (OUTER EDGE OF SHOE LOWER THAN CENTER PORTION OF

SHOE) IS UNACCEPTABLE AND WILL BE REJECTED.

3. FLATNESS OF BACKSIDE

THE BACKSIDE SHALL BE MEASURED FOR FLATNESS USING A PLANEKATOR AND

SHALL BE FLAT WITHIN 0.001 INCHES. A MINIMUM OF 4 MEASUREMENTS

ALONG EACH EDGE (1 INCH IN FROM EDGE) AND 2 DIAGONAL MEASUREMENTS

FROM THE I.D. TO O.D. CORNERS SHALL BE TAKEN.

4. VARIATION IN THICKNESS

A MINIMUM OF 8 EVENLY SPACED MEASUREMENT PER SHOE SHALL BE TAKEN

AS SHOWN BELOW, ON 3 CIRCLES CONCENTRIC WITH THE BORE, I.E., NEAR

THE THICKNESS VARIATION OF THE 8 EVENLY SPACED MEASUREMENTS ON

EACH SHOE SHALL BE WITHIN 0.001 INCHES, I.E. MAXIMUM THICKNESS

MINUS MINIMUM THICKNESS MUST BE LESS THAN 0.001 INCHES.

THE 8 EVENLY SPACED MEASUREMENTS SHALL THEN BE AVERAGED TO BE

CONSIDERED THE SHOE THICKNESS. THE VARIATION OF EACH SHOE TO THE

AVERAGE OF ALL SHOE THICKNESSES (THE AVERAGE OF EACH INDIVIDUAL

SHOE THICKNESSES) SHALL BE COMPARED AND SHALL NOT EXCEED 0.0012

INCHES, I.E. THE ABSOLUTE VALUE OF THE INDIVIDUAL SHOE THICKNESS

MINUS THE AVERAGE OF ALL SHOE THICKNESSES MUST BE LESS THAN 0.0012

INCHES.

4. SURFACE FINISH

THE BABBITTED SURFACE AND BACKSIDE OF THE SHOES SHALL HAVE A

FINISHED SURFACE OF 16 AND 63 MICROINCHES OR BETTER, RESPECTIVELY.

THE FINISH SHALL BE MEASURED USING A DIGITAL PROFILOMETER, OR AS

APPROVED.

TOLERANCES FOR STATIONARY THRUST BEARING SHOE SEGMENTS

SHOES MACHINED SEPARATELY

1. DISH FLATNESS

INDIVIDUAL SHOES SHALL BE MEASURED FOR FLATNESS USING THE SAME

GRANITE TABLE IN CONJUNCTION WITH A PLANEKATOR. THE GRANITE TABLE

SHALL BE CERTIFIED BY ITS SUPPLIER AS FLAT TO WITHIN 0.0005

INCHES. ALL MEASURING DEVICES SHALL BE ACCURATE TO 0.0001 INCHES.

THE BABBITTED SURFACE SHALL BE FLAT OR CONCAVE WITH THE MAXIMUM

LOW SPOT IN THE CENTER OF THE SHOE. THE LOW SPOT SHALL NOT EXCEED

THE AMOUNT INDICATED BELOW. THIS LOW SPOT SHALL NOT INCLUDE OIL

HOLES, THREADED HOLES, OR OIL GROOVES OR POCKETS. A BABBITTED

SURFACE THAT IS CONVEX (OUTER EDGE OF SHOE LOWER THAN CENTER

PORTION OF SHOE) IS UNACCEPTABLE AND WILL BE REJECTED.

A MINIMUM OF 7 SWEEP MEASUREMENTS PER SHOE SHALL BE TAKEN: 3

EVENLY SPACED MEASUREMENTS ON 3 CIRCLES CONCENTRIC WITH THE BORE,

I.E., NEAR THE I.D., CENTER, AND O.D., 2 ALONG THE LEADING EDGE

AND TRAILING EDGE OF THE SHOE, AND 2 FROM THE OPPOSITE CORNERS.

SEE SKETCHES BELOW FOR DIRECTION AND TOLERANCES:

0.0005 INCHES 0.0015 INCHES 0.0015 INCHES

PRIOR TO PERFORMING EACH SWEEP, ZERO THE MEASURING DEVICE USING

THE SAME LOCATION IN THE CENTER OF THE SHOE. REPORT LOW SPOTS AS

A NEGATIVE READING AND HIGH SPOTS AS POSITIVE.

2. FLATNESS OF BACKSIDE

THE BACKSIDE SHALL BE MEASURED FOR FLATNESS USING A PLANEKATOR AND

SHALL BE FLAT WITHIN 0.001 INCHES. A MINIMUM OF 4 MEASUREMENTS

ALONG EACH EDGE (1 INCH IN FROM EDGE) AND 2 DIAGONAL MEASUREMENTS

FROM THE I.D. TO O.D. CORNERS SHALL BE TAKEN.

3. VARIATION IN THICKNESS

A MINIMUM OF 8 EVENLY SPACED MEASUREMENT PER SHOE SHALL BE TAKEN

AS SHOWN BELOW, ON 3 CIRCLES CONCENTRIC WITH THE BORE, I.E., NEAR

THE THICKNESS VARIATION OF THE 8 EVENLY SPACED MEASUREMENTS ON

EACH SHOE SHALL BE WITHIN 0.001 INCHES, I.E. MAXIMUM THICKNESS

MINUS MINIMUM THICKNESS MUST BE LESS THAN 0.001 INCHES.

THE 8 EVENLY SPACED MEASUREMENTS SHALL THEN BE AVERAGED TO BE

CONSIDERED THE SHOE THICKNESS. THE VARIATION OF EACH SHOE TO THE

AVERAGE OF ALL SHOE THICKNESSES (THE AVERAGE OF EACH INDIVIDUAL

SHOE THICKNESSES) SHALL BE COMPARED AND SHALL NOT EXCEED 0.0012

INCHES, I.E. THE ABSOLUTE VALUE OF THE INDIVIDUAL SHOE THICKNESS

MINUS THE AVERAGE OF ALL SHOE THICKNESSES MUST BE LESS THAN 0.0012

INCHES.

4. SURFACE FINISH

THE BABBITTED SURFACE AND BACKSIDE OF THE SHOES SHALL HAVE A

FINISHED SURFACE OF 16 AND 63 MICROINCHES OR BETTER, RESPECTIVELY.

THE FINISH SHALL BE MEASURED USING A DIGITAL PROFILOMETER, OR AS

APPROVED.

Amend 0001