37551626 Stern Tube Bearings and Seal Installation Maintanance and Repair

5/17/2018 37551626 Stern Tube Bearings and Seal Installation Maintanance and Repair

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WAUKESHA

STERN TUBE BEARINGSAND SEALS

INSTALLATION , MA INTENANCEAND OPERATING

MANUAL NO. 164-000-044

_. " . . . . _ _ . _ , . " INSTRUCTIONSu . S. Navy/Military Sealift Command OWNER

YARDHULL NUMBER

Tacoma Boatbui1ding Company

Stalwart Cla~s T-AGOS Ocean Surveillauce Vessels NAME403 through 414

YOUR P.O. 71241-10274 OUR S.D. NJ.4B 67294and 67799SERIAL NO,1674 thru 1697

April 1983

P. O. Box 798 .. Waukesp~rR~~s~linsin 53186~r -+~ t~ (, .:)U. .AMERICA'S LEADING MANUFACTURER OF BEARINJi~ SEALS FOR MARINE POWER,INDUSTRIES


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Section 1.Section 2.Section 3.

3 . 13 . 23.33.43 . 53 . 63 . 73 . 83 . 93 . 1 03.11

Section 4.4 . 14 . 24 . 34 . 4

, Section 5.5 . 15 . 25 . 35.4

Section 6.Section 7.Section 8.

TABLE OF CONT-ENTS

General Information . . . . . . . . . . . . . . . . . . . . .Storage and Handling .Stem Tube Seals .General Information . . . . . . . . . . . . . . . . . . . . . . . . .Aft Seal Description .Aft Seal Assembly Instructions .Aft Seal Installation Instructions , .Measurement Instructions for Shaft Wear , .Reading the Wear Down Gage .Forward Seal Description .Forward Seal Assembly Instructions .Forward Seal Installation Instructions .How to Reposition the Forward Liner .Renewal of Seal Rings by Bonding - .

Stem Tube Bearings .General Information . . . . . . . . . . . . . . . . . . .Fitting Stern Tube Bearings .Bore Sighting Methods ..........................Bar Types and Set-Ups .Lube Oil Systems .Aft Seal Static Cavity ..........................Stern Tube Main System ~ .Forward Stem Tube Seal .Recommended Lubricating Oils .Trouble Shooting .Spare Parts List and Ordering Instructions ~Parts Listing and Illustrations

Section 9. Drawings and Data ................

Page1 - 1

2 - 1

3 - 13 - 13 - 23 - 33 - 33 - 43 - 63 - 73 - 73 - 93 93 - 1 0

4 - 14 - 14 - 14-24 - 3

5 - 15 - 15 - 15 - 15 - 1

6 - 1

7 - 1

8 - 1

9-1


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MARK IIBEARINGS AND SEALS

INSTALLATION INSTRUCTIONS

SECTION L GENERAL INFORMATIONThe purpose of this manual is to provide installation, operation, and mainte-nance procedures for the Waukesha Mark II Series stern tube bearings andseals. These procedures have been carefully developed by Waukesha engineersand, if followed carefully, will insure a quality installation and reliable operation.To insure satisfactory installation, a Waukesha Bearings Installation Supervisorshould be present. He can also provide advice on technical matters and assistancein conducting various static tests. Qualified Waukesha personnel are also availableupon request to assist in any maintenance and repair which may be required.SECTION 2. STORAGE AND HANDLINGAll Waukesha assemblies and component parts are carefully inspected at themanufacturing facility. Each part is then packaged in protective material toprevent damage in transit or in storage for up to six months.Upon arrival, make a visual inspection of all shipping containers to determineany evidence of damage during shipment. Open aU shipping containers andmake a thorough inspection for any signs of damage. If damage is found,notify the carrier immediately.If damage is not found, but the components received do not agree with thebill of lading on the initial order, notify Waukesha Bearings Corporationimmediately.After inspection of all components, carefully repack them to avoid damagewhile in storage. Also avoid the use of hooks and slings which may causedamage to containers and their contents.SECTION 3. MARK II STERN TUBE SEALS3.1 General InformationThe Mark II tailshaft support system consists of four components. The AftSeal Assembly (Sections 3.2 to 3.6); the Forward Seal Assembly (Section 3.7to 3.10); the Stern Tube Bearings (Section 4) and the Lube Oil System (Section5). In some configurations the Lube Oil System consists of more than oneassembly.

1.1


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3.2 Aft Seal DescriptionThe Aft Seal Assembly shown in Figure 3.1 consists of the aft seal housing andthe aft propeller shaft liner. The aft seal housing contains the flange, two inter-mediate rings, and a split aft cover. When bolted together, these housing partsclamp the aft seal ring (No.1 ring), the inner seal ring (No.2 ring) and the for-ward seal ring (No.3 ring) in place.The seal rings, made of a water and oil resistant elastomer, have lips which rideon the shaft liner. The shaft liner, which is bolted to the propeller and thusrotates with the tailshaft, is made of high wear resistant steel alloy. Contactof the seal lips with the liner is maintained by springs, sea water pressure,and oil pressure (see Section 5).

AFT PROPELLER -~SHAFT LINER

SPLIT AFTCOVERINTERMEDIATERING-- ....

PLUG ANDPACKING RING

INTERMEDIATERING

AFTSEALRING(NO.1)

FORWARDSEAL RING'(NO.3)

Figure 3.1 Aft Seal Assembly

Sea water pressure, a function of the ship's draft, acts on the two aft seal rings(No. land No.2) which face aft. The first ring seals foreign matt~r from thesecond seal ring. The second ring seals oil in the static cavity. "

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3.3 Aft Seal Assembly InstructionsThoroughly clean all parts, inspect for burrs or defects, and repair as required.Lay the flange on a clean, flat surface, with the recess for the forward sealring up. Insert the forward seal ring in the recess with the lip downward.Place the forward intermediate ring in position, bolt together with the hexhead bolts and locking tab washers provided, and bend the washers to lock.Insert the inner seal ring in the recess of the intermediate ring, with the lipupward. Place the aft intermediate ring in position and secure with the hex.head bolts and locking tab washers as described above. Insert the aft sealring in the recess of the intermediate ring with the lip upward, place thesplit aft cover in position and secure with hex head bolts and locking tabwashers. Install all plugs and packing rings.

CAUTION.Lubricate the seal lips with a light lube oil beforeinstalling the aft propeller shaft liner.

Install the aft propeller shaft liner in the aft seal housing being careful not todamage the seal rings.Place the distance straps (furnished with the Aft Seal Assembly) in position be-tween the flange and propeller shaft liner and secure with hex head bolts. Thedistance straps hold the shaft liner in position until the aft seal assembly isready for installation. Wrap the entire assembly to protect it from contarnina-tion and damage.

3.4 Aft Seal Installation InstructionsPlace the Aft Seal Assembly, with distance straps attached, in position on thestem tube.

NOTEDo not secure the aft seal assembly to the stemtube at this time.

Draw in the propeller shaft, key the propeller to the. shaft and draw the pro-peller shaft to the seal. Bolt the shaft liner to the ,propeller.' This willcause the rubber ring in the propeller counterbore to be comp~ssed andseal between the shaft liner and the propeller shaft. Re:qove the distancestraps, insure that the propeller shaft is axially located in the proper posi-tion, and both the aft seal housing to the stern tube with weardown gageplugs top and bottom.

CAUTIONDuring installation or removal procedures, theshaft liner must not be drawn out of the aft sealhousing or damage to the seal lips may result.


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3.5 Measurement Instructions for Bearing WearAfter shaft installation is complete it is imperative that therunning clearances of the bearings be recorded. The measurementstaken serve as a reference point in determining bearing wear whencompared to measurements taken after the bearings have been inservice. Procedure 1 below is to be used at the Mid Bearing andProcedure 2 is carried out at the Aft and Forward Seals for therespective adjacent Bearings.Procedure 1 - Mid Bearing (See Figure 3.2)

1. The Wear Down Gage and Instructions are furnished with theMark II Systern.

2. Remove the bronze threaded plugs located on the top and thebottom of the mid bearing tube immediately aft of the midbearing (see Drawing DD-164000044).

3. Insert the Wear Down Gage in top threaded hole as shown andtighten firmly. Mark the tube and the gage so that it maybe installed to the same depth during subsequent readings.

4. Carefully take the gage reading and record it on Table 3.1.NOTE

Instructions on reading the Hear Down Gageare described in Section 3.6.

PLUGW EAR DOW NGAUGE

3-4Figure 3.2 Wear Down Gage Installation at Mid Bearing


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5. Repeat Steps 3 and 4 for the bottom threaded hole.6. Remove the gage and replace the plugs.

Procedure 2 - Aft and Forward Bearing (See Figure 3.3)

1. The outside diameter of the aft seal cover immediately for-ward of the aft propeller shaft liner has been machined toa finished surface on the top and bottom of the seals. A3/16" wide x 1/8" deep slot is also provided at each location(see Drawing C-164220003). Clean these surfaces. the slots,and the liner before taking measurements.

2. Place the flat surface of a depth micrometer on the top ofthe aft seal housing as shown in Figure 3.3 and measure thedistance to the liner. Record the measurement on Table 3.1.

DEPTHMICROMETER

SPLIT AFTCOVER

AFT PROPELLERSHAFT LINER

Figure 3.3 Wear Down Gage Installation at Aft Seal

3. Repeat Step 2 on the bottom of the aft seal housing.4. Use the depth micrometer to measure the distance between

the surface of the forwird cover and the forward liner atthe top and the bottom of forward seal in a similar manner.Two 0.16" diameter holes are provided through which the mea-surements can be made (see Drawing C-164200003).

If any bearing wear occurs it can be determined from subsequentreadings as the top reading will increase and the bottom readingwill decrease.


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TABL,E 3.1

WEARDOWN READINGS RECORDEDInches x 2.54 m/m ""Millimeters Millimeters x .03937 = = Inches

Inch MetricDate Top Bottom Top Bottom Comments

3.6 Reading the Wear Down GageFigure 3.4 shows an example of a Wear Down Gage graduated in inches,tenths of inches, and thousandths of inches. The zero position of the lowerscale on the upper scale indicates that the reading is more than 2.000 inchesand less than 2.100 inches. Closer inspection shows that the reading is greaterthan 2.050 inches but less than 2.075. The exact reading is then determinedby adding to 2.050 inches the number of the graduations in thousandths onthe lower scale which is most closely aligned with a graduation on the upperscale. In the example shown, this number is 12 and therefore the reading is2.050 inches plus .012 inches or a total reading of 2.062 inches.

INCH

2

EXAMPLE - 2" + .050 + .012 = 2.062

Figure 3.4 Wear Down Gage Reading (Inches)3-6


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Figure 3.5 shows a similar example of the same measurement using a WearDown Gage graduated in centimeters and millimeters. The position of leftmost graduation of the lower scale on the upper scale indicates that the read-ing is more than 5 centimeters. Closer inspection shows that the reading isgreater than 5.2 centimeters but less than 5.3 centimeters. The exact readingis then determined by adding to 5.2 centimeters (or 52 moo) the number ofthe graduation in tenths of millimeters on the lower scale which is mostclosely aligned with a graduation on the upper scale. In the example shown,this number is 4 and therefore the reading is 52 mm plus .4 mm or 52.4 mm.

METRIC

"--'-~-,_/

Figure 3.5 Wear Down Gage (Metric)

3.7 Forward Seal DescriptionThe Forward Seal Assembly, shown in Figure 3.6, consists of the forwardseal housing, the forward seal shaft liner, and the clamp ring. The forwardseal housing contains the flange, an intermediate ring and a forward cover.When bolted together, these housing parts clamp the aft seal ring (No.4 ring)and the forward seal ring (No.5 ring) in place. The seal rings are similar tothe seal rings in the Aft Seal Assembly, described in paragraph 3.2. The staticoil pressure in the stern tube, controlled by the lube oil system described inSection 5, acts on the aft seal ring (No.4) to seal oil in the stern tube. Theforward seal ring (No. 5) seals oil between the two seal rings to provide lubri-cation for the aft seal ring.

3.8 Forward Seal Assembly Instructions

.. . - -~--..._.. ...

Thoroughly clean all parts, inspect for burrs or defects, and repair as required.Lay the flange on a clean, flat surface with the recess for the aft seal ring up.Insert the aft seal ring in the recess with the lip downward. Place the inter-mediate ring in position, and insert the forward seal ring into the recess of theintermediate ring. Place the forward cover in position, secure with hex headbolts and locking tab washers, and bend the washers to lock.


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INTERMEDIATERING

FORWARD SEALSHAFT LINER

FORWARDSEAL RING(NO.5)

Figure 3.6 Forward Seal Assembly

CAUTIONLubricate the seal lips with a light lube oil beforeinstalling the forward seal shaft liner.

Install the forward seal shaft liner in the forward seal housing being careful notto damage the seal rings.Place the distance straps (furnished with the Forward Seal Assembly) in positionbetween the flange and propeller shaft liner and secure with hex head bolts. Thedistance straps hold the shaft liner in position until the forward seal assembly isready for installation. Wrap the entire assembly to protect it from contamina-tion and damage.

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3.9 Forward Seal Installation Instructions~ .. ' For Shafts Drawn In From The Outside

After the Aft Seal Assembly has been installed (paragraph 3.4), and the propel-ler shaft is drawn in, slide the Forward Seal Assembly and the rubber O-ringonto the shaft and up to the stern tube. Position the clamp ring per InstallationDrawing DI) 164-000 OM and align the forward seal liner as described inparagraph 3.10.For Shafts DralWl In From The InsideSHde the rubber O-ring apd the Forward Seal Assembly ontQ the propeller shaftas jt is being drawp ; P y O the stern tuhe Posjtjgn the clamp rin~ per InstallatjonDra'lfiring and aljgn th e fOrward Seal ljner as de sc ri be d in

CAUTIONDuring installation or removal procedures, the shaftliner must not be drawn out of the forward sealhousing or damage to the seal lips may result.

3.10 How To Reposition And Align The Forward Seal Liner

The forward seal liner may be repositioned, without draining the oil from thestem tube oil system, by following the steps listed below.1. Remove the cover from the propeller shaft coupling.2. Position a jack on each side of the propeller shaft between the coupling

flange and the forward face of the clamp ring. Apply light pressure withthe jacks to insure that the clamp ring and attached liner cannot slideforward.

3. Carefully loosen the bolts holding the forward seal liner to the clampring.

NOTEBecause the O-ring seal is now loosened, a slight oilleak may occur. It is unavoidable but is not causefor concern.

4. Carefully loosen the bolts securing the clamp ring to the propellershaft.

5. Apply equal pressure to both jacks. Move the clamp ring and forwardseal liner aft approximately 1/8 inch.

6. Tighten the clamp ring securing bolts and remove the jacks.7. Tighten the bolts which secure the forward seal liner to the clamp ring.


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Alignment of the forward seal liner is required during installation of the forwardseal or at any time that repositioning of the liner is necessary.The liner is properly positioned when the centerline of the liner is aligned withthe centerline of the propeller shaft.Procedures are as follows:1. The forward seal liner and clamp ring must not be tipped in relationship

to the propeller shaft. Using a dial indicator check the flange runoutbetween the forward seal casing and the liner flange. A small jack screw(made from a nut and bolt) may be used to adjust the liner's axial posi-tion as close to 0.000" Total Indicator Runout as possible, but not toexceed 0.005").

2. The forward seal liner must be concentric radially with the propeller shaft.Again use a dial indicator and place it on the outside diameter of the lineroperating surface. Rotate the propeller shaft and note the amounts andlocations of the highest and lowest indicator readings.

3. Rotate the shaft until the high reading location is on the indicator dial.4. Slightly loosen the bolts holding the forward seal liner to the clamp ring.5. Tap the liner lightly with a hammer and block of wood or brass bar

until the liner has dropped a distance equal to one-half the differencebetween the high and low indicator readings.

6. Tighten the bolts which secure the forward seal liner to the clamp ring.7. Repeat steps 1 to 6 above until no further adjustments are required.8. Tighten all bolts and reinstall the cover on the propeller shaft coupling.

coupling.

3.11 Renewal Of Seal Rings By BondingThe seal rings in both the Aft and Forward Seal Assemblies may be removedand replaced without removal of the propeller shaft. This procedure, whichinvolves the bonding of the new seal rings around the shaft and rebuilding theseal rings in place, is described below.

NOTETo insure satisfactory installation a Waukesha BearingsServiceman should be called to assist in any seal ringrenewal task using this method,

Forward Seal Ring Renewal1. Forward seal ring renewal procedures require 5 to 9 hours.2. It is recommended that the ship be docked or tipped to place the stern

boss out of the water to remove sea water pressure from aft seal.3. Drain the stern tube oil and clean approximately 18 inches of the pro-

peller shaft forward of the clamp ring.4. Remove the damp ring and slide the Ovring and forward shaft liner for-ward on to the clean shaft area.5. Remove the bolts from the support ring and slide the support ring for-ward on the propeller shaft. The forward seal ring, the intermediate ring,and the aft seal ring may come out at the same time.

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NOTEDo not cut off old seal rings at this time.

6. Carefully bond the new seal ring (s) around the shaft. Be sure that theseal ring lips are facing aft. Clean off excess epoxy and carefully inspectthe bond joint.

7. Cut and remove the old seal ring (s).8. Reassemble the forward seal (paragraphs 3.8 and 3.9) and fill the systemwith oil.

9. Align the forward seal liner per paragraph 3.10.Aft Seal Ring Renewal1. Aft seal ring renewal procedures require approximately 30 hours.2. The ship must be docked or tipped to place the stern boss out of the

water.3. Drain the stern tube oil and clean approximately 18 inches of the pro-

peller shaft forward of the clamp ring.4. Remove the rope guard.5. Remove the cover from the propeller shaft coupling and uncouple the

propeller shaft.6. Ifall rings are to be replaced, including the forward seal rings, remove

the clamp ring and slide the O-ring and forward seal liner forward onthe clean shaft area. Care should be taken not to damage the O-ringunless replacement is required.

7. If only aft seal rings are to be replaced, remove the clamp ring, unboltthe forward seal assembly from the bulkhead and slide the entire assem-bly forward on the clean shaft area.

CAUTION

Clearance between the propeller shaft and the forwardseal liner is approximately 0.015 inch and care mustbe taken when sliding the forward seal assembly onthe shaft.

7. Support the aft seal using the lift eye provided. Guide ring centeringscrews are to be fitted into the oil holes (1/2 inch pipe thread) afterremoval of the plugs and packing rings.8. Unbolt the seal casing from the stern boss and slide the propellershaft and aft seal assembly aft about 12 inches.9. The aft seal ring and inner seal ring, both with the seal lips facing aftand the forward seal ring with the seal lip facing forward are accessibleby removing the split aft cover.

NOTEDo not cut off old seal rings at this time.

10. Carefully bond the new seal ring (s) around the shaft. Insure that theseal ring lips face the right direction. Clean excess epoxy and carefullyinspect the bond joint.11. Cut and remove the oil seal ring (s),

12. Reassemble the aft seal (paragraphs 3.3 and 3.4) and fill the system withoil.


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SECTION 4. STERN TUBE BEARINGS4.1 General InformationWaukesha stern tube bearings, when used with Waukesha forward and aft sealsand oil lubrication system, provide a propeller shaft support system which mini-mizes friction and wear. The stem tube bearings consist of one or more bearingswhich are pressed in and secured to the stem tube.The bearing sleeves are made of high strength ductile iron and centrifically linedwith a high tin base babbitt. The bearing bore is normally finish machined tofit the propeller shaft and the outside diameter is semifinished for final machin-ing at the shipyard.4.2 Fitting Stern Tube BearingsTwo procedures are commonly used for fitting stern tubes. Using the first, thestern frame is finish machined, the stern tube is pressed in and secured by bolt-ing or welding, the stern tube is bored and the bearings are then pressed into thestern tube. In the second procedure, the stem tube is bored in the shop andfitted with its bearings and then the entire assembly is pressed into the sternframe at the shipyard. The first procedure is generally used except on ships inretrofit which require stern tube replacement, in which case procedure two ismore acceptable. See additiona'I comments on page 4-4.Waukesha Bearings recommends boring of the stern tube to provide an interfer-ence fit. For aft bearings, three fit diameters are generally used with the mid-diameter located axially between the two sections of the aft bearing. This assuressupport at the center of the two aft bearings and reduces the distance the bearingsare pressed. Forward bearings generally have two fits. Recommended press fitspressures (using 0.001" to 0.002" interference fit) are shown in Table 4.1.

PressureSeal Size (Tons)Aft Bearing 155 to 330 5 to 10

355 to 500 10 to 15500 to 630 15 to 25670 to 750 25 to 100800 and up 45 to 100

Forward Bearing 155 to 330 2 to 8355 to 500 5 to 10500 to 630 8 to 15670 to 750 15 to 50800 and up 25 to 100

Table 4.1 Recommended Press Fit Pressures

These pressures are dependent upon several factors which are the respon-sibility of the shipyard. The accuracy of measuring, parallelism of the bore,temperatures of the bearing and the stern tube, the quality of the finish, andthe lubricant used all affect the fit pressures. Some owners require higher mini-mum pressures and good judgement should be expected from shipyard personnelwhile performing machining and pressing operations. For these reasons, thepressure valves in Table 4.1 are to be used as a guide line only.


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Shrink fitting of the bearing, either by heating of the stern tube or chilling ofbearing shell, is not recommended. The bearing babbitt is metallurgicallybonded to the shell and, because the babbitt material has an expansion ratedifferent from the ductile iron shell, heating or chilling may adversely affectthis bond. Also, once the bearing is installed with this procedure, the actualpress fit is unknown, thus creating a problem if removal of the bearing at a latertime is required.The stern tube faces should be smooth machined to approximately 125 RMS.This will provide an acceptable sealing surface for a dry, 1/32 inch thick gasket.

Bearings are seldom press fit without a lubricant and each shipyard typicallyhas its own preference. A lubricant such as Powder Moly-cote, Moly-cote G,Moly-cote and oil, Felpro, Neverseeze, STP. or a suitable substutute is rec-ommended.

4.3 Bore Sighting Methods

Waukesha Bearings does not specify a shaft alignment since this is specifiedby the builder. Several systems are now in use for establishing a referenceline for boring and are listed below in the order of their recognized accuracy.Laser Beam Reference - A high frequency light beam signal transmitted froman emitter to a target (similar to looking through an optical telescope). Thispinpoint signal is located and measured electrically to a high degree of accuracy.The description of the optical system below also applies to the laser system.

Optical Reference - The optical alignment telescope and auto-accumulated re-flected light from the scope is projected to the aft end of the bore onto areflecting mirror target on the referenced center. This is normally the bull gearcenter, or a reference point where the mirror face will be in line with, andperpendicular to, the desired center line.Once the scope and mirror are in line, the light transmitted from the scope isreflected back from the mirror at the reference point of the proposed alignment.From this optical datum line, intermediate targets can be set up between the scopeand the reference target mirror and can be centered to this datum line. The mech-anical center can then be measured.

Once the scope is set up as described above, the boring bar support bearings canbe set up with the target in the bearing, and all of the bar support bearings canbe set up to this optical line before inserting the bar. Using this method, measure-ments by micrometer to center of the bearings is eliminated.This set up, which is extremely accurate, must be done when all parts of thestem area are at the same temperature. Inaccuracies can be expected if the hullis exposed to the sun or structural welding is being performed. Once set up, itwill accurately measure the hull distortion caused by heat from the sun or weldingon the major structure.

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Conical Sight Reference - This method employs an alignment telescope which isset up on the aft flange of the reference bull gear coupling. It is to be used per-pendicular to the coupling face. A target is set up in the stem tube which willallow for plotting of four points 900 apart, within the circle described by thescope sight line, when the coupling is rotated. The true center can be plottedfrom these four points of reference. The mechanical center is located withdividers and marked on the target with a point. Points at top, bottom, port,and starboard should be marked at each location the target is set up and themechanical center marked for use later in positioning the boring bar.

Peep Sight Reference - This method required that a fixture be fabricated inwhich two aligned pin holes are provided 3to 10 feet apart. One end of thefixture is designed to mount on the bull gear coupling face with the pin holesexactly centered from the coupling. A light source is provided between theadjacent pin-hole and the coupling. A target is set up in the stern tube and iscentered so the light is visable through the target and the pin holes. The mechanical center is located and recorded as to its position relative to the pin holedatum. All reference centers for setting up the bar and support bearings willhave to be located individually.

Taut Wire Reference - A wire is tightly stretched from the known center atthe bull gear coupling to the aft end of the stern tube. The wire must bestretched perpendicular to the face of the bull gear coupling and be square toit. The tube bore is measured to the wire with a micrometer and the verticalreadings interpreted against the calculated sag of the wire at each point.

4.4 Bar Types and Set-Ups

In all cases, the heaviest boring bar available is recommended. The boring barlength should be long enough to bore and face both ends of the tube. If the baris too short, other set-ups would have to be made. The bar should be set upto a design engineered alignment in new construction or to the existing align-ment in the retrofit of older vessels. In retrofit it may be necessary to set upfor correcting errors in the original boring or to give a new alignment to theshaft.

On a long bar that passes through the entire tube, three support bearings areusually used and, if the bar is light, a four bearing support would be preferredor the result may be a chattering tool cut. The outboard (aft most) support bear-ing should be fixed to an external structure fabricated outside the stern boss.The second support bearing should be located as close to the end of the sterntube bore as possible without tool carrier interference. This will support the baras rigidly as possible during the boring and facing of the stern tube boss. On athree support bearing set-up, the mid bearing is positioned in the approximatecenter of the stern tube and preferably in the center of the bar span. Whenfour support bearings are used, the third support bearing should be positionedclose to the aft end of the bore for the forward stern tube bearing. The fourthsupport bearing should be located just forward of the stern tube in the shaftalley. The drive can be on either end of the stern tube.


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The distance between the support bearings at the ends of the planned bar set-upshould be established and the bar set-up on a flat reference surface supportedat these two points to check for bar sags at the intermediate support bearing posi-tions. Calculations can then be made for raising the bar to compensate for sagsand produce a true bore. Few yards center the boring bar optically and rely onmeasured set-ups in the tube, where the sag factor is important in centering thebar.Care must be exercised to be sure the mid support bearings are accurately posi-tioned. A sagging bar will produce a bore which is sloped to the middle of thestern tube. This frequently occurs when the bar is positioned with micrometersfrom an inaccurate, rough bored tube diameter which has not been checkedduring. the alignment.When a short bar is used, two set-ups may be required to machine the forwardand aft bearing bores. Extra care MUST be taken in centering the supportbearings and the bar so the two borings are in line to the same center. In thiscase, the set-up is made twice and the skill of the machinist to accurately meas-ure and set up the bar the second time is most essential.

Addit.ional Comments from Page 4-1:A modification of the second procedure is employed on the T-AGOS vessels,and involves the use of chocking resin to install the bearings in thestrut barrel and stern tube. A general arrangement and procedure is shownon drawing F-991-116 and the specific installation is shown on drawingDD-164000044. both of which can be found at the back of this manual_ Assupplied byWBC, the bearings are pressed into sleeves and ready for in-stallation (see drawings D-075-001-067, -068, -070, and -071).Mount optical targets in the center of each end of each bearing, and in-stall the bearing assemblies in their respective locations; note thatthe port and starboard strut bearings are not identical. Once the opticsand jack bolts have been used to correctly align and lock the bearingsin place, drill and tap ~"-13 holes a minimum of 1\" deep (8) places onthe aft face of the strut barrel and (6) places on the forward face ofthe stern tube using the respective flanges as templates. Carefully cleanout a ll chips and cutting oiL Install the 1.;"-13 x 3" long socket headcap screws provided (Items 6 and 7 on OD-164000044); they do not needto be tightened excessively since the chocking resin will lock them inplace. Install the temporary plugs in the oil inlet holes on the strutbarrels to prevent tbe entry of chocking resin. Recheck bearing alignmentand adjust i f it was disturbed during machining.FollOWing the recommendations of the chocking resin manufacturer, chockthe bearings in place. Once the chocking resin has set, remove any instal-lation material and excess resin and inspect all oil grooves to insurethat they have not been plugged.Note that with this type of installation, should bearing replacement everbe necessary, the bearings can be pulled from their sleeves and replacedwithout disturbing alignment.

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SECTION 5. LUBE OIL SYSTEMS5 . 1 Aft Seal Static CavityThe aft seal static cavity normally contains a 50:50 mix of water and oilafter a year's operation and does not seem to vary if the inspection periodextends to two years or more.Drain the oil and water and refill immediately with fresh oil. Many ownersuse a mixture of oil and STP for this purpose.

NOTEOccasionally the oil from the aft seal will leak outafter the seal has been out of the water for sometime or when it is refilled as above. This is not un-common.

This leak occurs because two aftmost seals had beenoperating with water pressure against them and have.seated or run in that position. When the water pres-sure is removed the seal contact is changed. Also,the seal no longer has the surface adhesion of thewater at the lip.Pack a heavy grease around the aft liner at the aftseal cover to effect a seal and fill the aft seal withoil. Refrain from turning the engine until the shipis waterborne and sea water pressure on the aft sealassembly has restored the seal contact to keep the oilin.

5.2 Stern Tube Main SystemPrior to drydocking remove an oil sample from both the drain tank and gravitytank. These may be analyzed to determine the oil's condition at the lowest andhighest points in the system, If the reports indicate that the oil is satisfactory,the oil need not be changed. Otherwise it should be replaced.5.3 Forward Stem Tube SealDrain and refill this system if it has not been done during the past year.

5.4 Recommended Lubricating Oils

" /~~

Oils used with Waukesha Bearings Corporation stern tube bearings and sealsshould be a high quality, non-emulsifying type with a high quality, non-emulsifyingtype with a viscosity of 300 to 600 SSU at 1000F and should be provided withoxidation, rust, and foam inhibitors. Poorly refined oils or oils with additivescontaining organic soaps or water soluble materials should be avoided sincethey tend to suspend water. The oil selected must not adversely affect the nitrilebuna rubber seal rings. Oils which contain excessive amounts of chlorine orsulfur have been found to adversely affect this type of equipment.


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The list below stresses the paraffin-base oils because napthenic-base oils aremore associated with the swelling of buna nitrile rubber. It is to be cautioned,however, that for operating conditions of extreme coldness (arctic, etc.) anapthenic-base oil having good water antifoam inhibitors should be consideredbecause of the considerably lower pour point obtainable relative to that typicalof the paraffin-base oils.The following list (not intended to be all-inclusive) indicates typical oils thatshould be satisfactory, based on published properties, test results, and/or oper-ating experience. For use of other oils, consult with the oil manufacturer toinsure proper characteristics.BP (British Petroleum) Ltd.

BP Energol TH 125-HBBP Energol TH 150-HB

Caltex Petroleum CorporationCaltex Regal Oil PC (R & 0)Caltex Regal Oil PE (R & 0)

Chevron Oil CompanyChevron OC-15Chevron OC-19

PetrofinaFina Turbine on MediumFina Turbine Oil HeavyFina Turbine Oil Extra HeavyFina Turbine Oil EP Heavy

Shell Oil CompanyShell Turbo Oil 33, 37, 41Shell Melina Oil 30Shell Argina Oil 30Shell Gardinia Oil 30

Esso International, Inc.Esso - Mar 52Esso - Mar 56Esso - Mar 65TRO - Mar 65

Sinclair Refining CompanySinturlite Supreme 315Sinturlite Supreme 465

Gulf Oil CorporationGulf Harmony 53Gulf Harmony 61Gulf Veritas V9

Texaco, Inc.Texaco Regal Oil PC (R & 0)Texaco Regal Oil PE (R & 0)Texaco Regal Marine 500

Union Oil CompanyUnax AW 315Mobile Oil Corporation

Mobil D.T.E. Oil Heavy MediumMobile D.T.E. Oil HeavyMobilgard 393Mobilgard 300Mobil D.T.E. 16 For cold waterMobil D.T.E. 18 operation

5-2


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SECTION 6. TROUBLE SHOOTING PROCEDURES

TROUBLE POSSIBLE CAUSE REMEDY

Forward seal oil tankoverflows

The aft seal ring (No;4) of the forward sealassembly (Fig. 3-6) ispassing oil forward orthe forward cover isloose.

Tighten forward cover bolts. Checkalignment of the forward propellershaft liner as described in paragraph3.10. If leakage continues, cap thevent and allow the forward seal ringto seal the tube.

Gravity tank over-flows and the for-ward seal tankempties into thestern tube

Forward liner is run-ning out.

Check alignment of the forward pro-peller shaft liner as described in par-agraph 3.10.

Oil leaks forwardinto the shaft alley Forward cover isloose. Tighten forward cover bolts. Checkalignment of the forward propellershaft liner as described in paragraph3.10. If leak continues, renew theseal ring per paragraph 3.11.

Seal lubricating oilturns black

Carbon from the sealrings gets in the oil asthe seal rings are runin. This trouble mayalso occur in the mainstern tube oil system.

Change the oil. If in the main systemoil, centrifuge the oil.

Oil is being lost aft.Loss is sudden andthere is an unusualincrease in oil con-sumption

Foreign matter islodged under theseal ring.

Stop the shaft and run astern for 5 or10 minutes. Then return to normalrun ahead.

Oil is being lost aftand has reached anunacceptable level

Seal rings are wornand permit leakageof normal weight,in-service oil.

Secure the stern tube lube oil pumpand add heavy weight oil (1000 SSUor 1500 SSU). This procedure doesnot affect bearing or seal operationbut can reduce or stop the leak.Check location of head tank andreposition if necessary.

Oil is being lost aft. Seal rings have failed.Loss of oil is suddenor complete and sys-tem cannot maintaina head of oil

...


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TROUBLE POSSIBLE CAUSE REMEDY

Oil is being lost aftand remedies listedabove have not cor-rected trouble

Seal rings have failed. Tip or dock ship and renew seal ringsfollowing procedures listed in Section3.11.

Sudden change inusual noise level(rumbling, grind-ing, squalling)from stern tubeor propeller area

6-2

Stern tube bearingsection is damaged.

Slow or stop the ship. Inspect pro-peller for damage. Check pressureand temperature gages for abnormalreadings. Inspect circulating pumpfilter or centrifuge the oil for babbittflakes which indicate bearing failure.


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SECTION 7. SPARE PARTS LIST AND ORDERING INSTRUCTIONS' . , __oJ

RECOMMENDED EMERGE NCY SHIPBOARD SPARE PARTS LISTThe fo l Iow tng part s are recommended by Waukesha Bearings Corporat ion

RecommendedQuantity Spare Part PartPer Ship Description Number Used On

16 Aft Seal Liner 230-294-004 Aft Seal AssemblyBolts Cl64-220-C:J316 Aft Seal Casing 230-347-001 Aft Seal AssemblyBolts Cl64-220-DD31 Aft O-Ring 231-986-029 Aft Sea 1 Assembly

C164-220-C031 Aft Liner Gasket 230-439-038 Aft Seal As s emb l yC164-220-::


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~-,/

. " '-~.-:"


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RECO~fENDED EMERGENCY SHORE-BASED SPARE PARTS LISTThe following parts are recommended by Waukesha Bearings Corporation

RecommendedQ ua nt i ty Spare PartDescription PartNumber Used On2 302-789-000tru t Bea ring ,Port Side

T ai ls ha ft B ea ri ng s& Sea ls, Inst al-lation Dwg. DD-164-000-044

2 302-790-000tru t Bea ring ,Starboard Side T ai lsha ft Bear ing s& Seals, Instal-lation Dwg. DD-164-000-0448 Mid/ForwardBearing, Port

& StarboardSides

302-791-000 T ails haf t B eari ngs& Seals, Instal-lation Dwg. DD-164-000-044

4 Kit s R.T.D. ReplacementKit 991-569-001Items 3-9,Quantity perBi 11 ofMaterial

St rut Bea rin gsPort & Starboard

4 Aft Seal Assy.Less Liner &Seal Rings

164-220-003less Items1, 6 & 8

T ails haf t B eari ngs& Seals, Instal-lation Dwg. DD-164-000-044

4 990-696-000tern Tube LubeOil Pump &Motor Assy.T ails haft Bea rin gs& Seals, Instal-lation Dwg. DD-164-000-044

PART ORDE RING INST RUCT IONSIn pl acin g orders for parts be certain that the following information is supplie

Part NameQuantity O ri gi na l P ur ch as erOriginal Order NumberOriginal Outfitting YardYour Purchase OrderY ou r Del iver y R equi rem entsShipping Instructions

A stock of some items are always on hand and available for immediate delivery.Firm delivery dates can only be established after consultation with the manufac-turing fac ility.


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SECTION 8.Figure 8l.Figure 82.Figure 83.~i@W e ~ 4.Figure 86.

-Figttt '@ 8 '+ .Figure 88.Figure 89.Figure 810.

PARTS LISTING AND ILLUSTRATIONSAft Seal AssemblyForward Seal AssemblyStern Tube Circulating Lube Oil System~t8m '1 l l iB8 ~t&ti8 Is:8!~eOil ~y8teJ1't


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23 4 5 6 5 7 8 5

1 09 1 1 1 2 1 3

1 41 5

1 41 5 1 41 5

Item No. Description Item No. Description1 Liner 9 Aft Intermediate Ring2 Distance Strap 10 Gage Plug3 Hex Hd Cap Screw 11 Packing Ring4 Hex Hd Cap Screw 12 Aft Casing Flange5 Locking Plate 13 Gasket6 Aft Cover 14 Seal Ring7 Aft Support Ring 15 Garter Spring8 Hex Hd Cap Screw 16 Gasket

Figure 8-1. Mark II Aft Seal Assembly


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2 3 4 5 6 7 98 1 0 1 1

1 3 1 31 4 1 4

Item No. Description Item No. Description1 Gasket 8 Liner2 Fwd Casing Flange 9 Clamp Ring3 Pipe Plug 10 Soc Head Cap Screw4 Fwd Intermediate Ring 11 Soc Head Cap Screw5 Fwd Cover 12 "0" Ring6 Locking Plate 13 Seal Ring7 Hex Hd Cap Screw 14 Garter Spring

Figure 8-2. Mark II Forward Seal Assembly


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4

..--:-:--9r:~.--8Un- '-~;c~ I f ~~~E\A~~D OUTLET

1 21 021 1

01 LORAIN FOR RETURNTO PURIFIER SYSTEM

NOTES;1. Tuthill Model OLPFV close coupled to V. h.p. 1750 rpm frame 561/60/115/230motor.

2. Oil to be a non-emulsifying type of 300-500 ssu @ 100F viscosity.3. The cooler is) or heater (12) if required by extreme operating conditions is de-

signed to permit regulation of the circulating oil to a satisfactory operatingt ern peratu re o

I rItem No. , Description Item No. DescriptionII 1 Oil Inlet (Stern Tubel 1% Dia. I.P.S. 10 Filteri 2 Shutoff Valve (% gate valve) 11 2 G,P.M_ Pump (seenote 1)Ii 3 Oil Level Gage 12 Heater (note 3)i 4 Oil Head Tank 50 Gal. 13 Oil Drain Tank 25 Gal Min.

5 , High Low Level Alarm 14 Oil Drain (Stern Tube) 1% Dia. I.P.S.6 Oil Vent (Drain Tank) 1% Dia. I.P.S. 15 Pressure Gage7 Pump Discharge Une % Dia, I.P.S. 16 Temperature Gage8 Cooler (note 3) 17 Shutoff Valve (1'k gate valve)9 Oil Vent (Stern Tube) 1% Dia. I.P.S.

Figure 8-3. Stern Tube Circulating Lube Oil System


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10" (see note 2)

i 50 "Existing1/2" NPSFTop andBottom

2see note 1) 1

1-1/2 approx.

Forward SealCasing4

Notes:1. Item 1 View Gage must show oil at all times.2. Shipyard must supply standard 1/2" pipe in most direct route possible for existing conditions.

Item No. Description1 View Gage2 Pipe Cap3 Fwd Seal Lube Oil Tank4 Gate Valve

Figure 8-6. Forward Seal Static Lube Oil SystemWBe Drawing C 230 332


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o

+CEMENT AS SHOWNUSE TOOL 976173- - - - + _ . : : : : : - - - -

+0A _ 1/16RUBBER I.D.if-

X~C+ iT'SB

DIA. C fiB X3/8 1/2 1.18 1.681/ 2 5/8 1.57 2.195/8 3/4 1.96 2.7111/16 71 8 2.16 3.037/8 11/8 2.75 3.87

1 '1/4 3.14 4.3911/8 17/16 3.53 4.9611/4 '9/16 3.93 5.5017/16 H3/16 4.52 6.3315/8 2 5.11 7.11

A Diameter of '0' ring after bonding.3.11 x shaft diameter (when B > 1/2")3.143.05 x shaft diameter (when B:. 1/2")3.14

B '0' ring section diameter (see main assemblydrawing DD-164-000-044)C 1.25 BX C + 11 B (see table for standard values)D Length of ring prior to bonding.

3.11 x shaft diameter + X (when B> 1/2")3.05 x shaft diameter + X (when 8; 1/2")

Figure S-S. '0' Ring Dimension Requirements - Diagonal Joint Method


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. . . . ,.-- . . . ." ' .

L

++0A -1/16

R U BB ER LD.-A- 'A Diameter of '0' ring after bonding.3.11 x shaft diameter (when B > 112")3.14

3.05 x shaft diameter (when e s 1/2"13.14B '0' ring section diameter (see main assembly drawing DD-16 4-000-044)L Length of ring prior to bonding.

3.11 x shaft diameter + r r B (when B > 1/2")3.05 x shaft diameter + T 1 B (when B 2 1/2")

Note:Vulcanize at 2850 joint to maintain Rubber Manufacturer's Association Standards of 30% of tensilestrength per square inch.

Figure 8-9. '0' Ring Dimension Requirements - Butt Joint Method


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Documents

37551626 Stern Tube Bearings and Seal Installation Maintanance and Repair