4 orkot marine manual

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Engineering ManualVersion 4.0


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Orkot Marine BearingsEngineering Manual for Rudder and Water Lubricated Propeller Shaft Bearings

Contents

Abo ut th is Ma nua l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

A Glob a l Approa ch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

Orkot Ma rine Bea ring s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

Ma na g eme nt Systems a nd Cla ssifica tion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

Ma te rial Propert ies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3

Service a nd Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Web Site . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

World Wide Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Ma rine Stock Tube Sizes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

Sta nda rd Production Ca pa city G uidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Cont a ct Det a ils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Rud de r Bea rings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7Bea ring Design Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Ma te rial Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Housing a nd Sha ft Req uirement s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Housing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Shaf t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

Desig n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

Wa ll Thickness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

Bea ring Inte rferen ce . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

Bea ring Cleara nce . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9Ma chining Tolera nce . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9

Wa te r Lub rica te d Ste rn Tub e Bea ring s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

Bea ring Design Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

Ma te rial Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

Shaf t Req uirement s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

Desig n . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

Multi Groo ve Bea ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

Tw in Gro ove Bea ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

Special Designs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10

Staves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11Wa te r Flow Ra te . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

Bearing Inte rference an d Clea rance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

Ma chining Tolera nce . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13

Fitting Met ho ds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14

Bon ding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

Ma chining Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17

Hea lth a nd Sa fet y Da ta . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

Calcula tion Shee ts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23


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2


About this Manual

The informa tion in this ma nua l allow s the u ser to

correctly d esign Orkot Marine Bea rings a nd g ives

guida nce on machining a nd f i t t ing. It is intended foruse by persons w ith technical training at their ow n

discretion. The design of Orkot Marine Bearings

should ta ke into account th e current rules and

regulations of the relevant classification society.

A Global Approach

Orkot Marine Bea rings is a w orld lea ding

man ufa cturer and supplier of bea ring s to t he shipping

and marine industries.

Supported b y an extensive globa l netw ork of

man ufa cturing plants, ag ents a nd d istr ibuto rs, Orkot

Marine Bearings a re ab le to o f fer the highest levels ofq uality of service a ssociated w ith a lead ing company

w ithin the ma rine industry.

Part o f t he Smiths group o f compa nies, Orkot Marine

Bearings have been a ctive within the Marine and

shipping industries fo r over 25 yea rs.

Extensive experience ha s been ga ined w ithin t he

shipbuilding and of fshore industr ies with a w ide

range o f a pplicat ions on boa rd both merchant and

milita ry vessels.

Orkot Marine Bearings

Orkot Marine Bea ring s are ma nufa ctured from a

unique synthetic composition incorporating solid

lubrican ts for dry running t o ensure out standing w ea rlife. Virtua lly no sw elling in sea w a ter a nd very low

therma l coeff icient o f e xpansion provide dimensiona l

stability in arctic and tropical seas. It does not corrode

or promo te corrosion of t he housing a nd to lerat es

both ed ge loa ding and misal ignment .

Management Systems andClassification

Orkot Composites operat e a fully integ rated

ma nag ement system w hich incorporat es, ISO

9000:2000 Quality Ma na g emen t Syste m, ISO

14001:1996 Environ ment a l Mana g emen t Syste ma nd OHSAS 18001:1999 Health a nd Safe ty

Manag ement System

Strict q uality control and testing ensure mat erial

conforman ce and ba tch tracea bili ty. Routine te sting is

performed to simulate the extreme operational

environments w here the ma terials are used.

Orkot Composites hold type approval certif icat ion fo r

TLM Ma rine a nd TXM Marine g rad es from t he w orlds

lead ing cla ssificat ion societies. We ca n supply full

l ist ing of the certi f icates w e ho ld upon req uest .

This listing can a lso be fo und o n our w ebsite:

www.orkotmarine.com
http://www.orkotmarine.com/http://www.orkotmarine.com/


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Properties Unit TLM Marine TXM Marine

Compressive Strength

Norma l t o La mina te N/mm 2 >300 >280

Pa ra lle l t o La mina te N/mm 2 >90 >90

Tensile Strength N/mm 2 >60 >55

Flexural Strength N/mm 2 >65 >65

Elastic Modulus

Bending N/mm 2 x 104 0.19 0.18

Tensile N/mm 2 x 104 0.32 0.32

Shear Strength N/mm 2 80 80

Impact Strength (ISO179/1987 Charpy Impact Unnotched)Norma l t o La mina te KJ/m 2 122 122

Hardness - Rockwell M 100 100

Density g /cm 3 1.3 1.3

Swell in Water, % of wall thickness %


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Properties Unit TLM Marine TXM Marine

Compressive Strength

Norma l t o La mina te lb s/in 2 >43511 >40611

Pa ra lle l t o La mina te lb s/in 2 >13053 >13053

Tensile Strength lb s/in 2 >8702 >7977

Flexural Strength lb s/in 2 >9427 >9427

Elastic Modulus

Bending lbs/in 2 x 104 27.557125 26.10675

Tensile lbs/in 2 x 104 46.412 46.412

Shear Strength lb s/in 2 11603 11603

Impact Strength (ISO179/1987 Charpy Impact Unnotched)Norma l t o La mina te KJ/in 2 0.079 0.079

Hardness - Rockwell M 100 100

Density lb s/in 3 0.047 0.047

Swell in Water, % of wall thickness %


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Reference od id Length Weight od id Length Weight(mm) (mm) (mm) (Kg) (inch) (inch) (inch) (lbs)

TLM 13 95 47.6 500 3.5 3.7 1.9 19.7 7.7

TLM 21 118 66.7 500 4.9 4.6 2.6 19.7 10.8

TLM 22 150 88.9 500 7.5 5.9 3.5 19.7 16.5

TLM 23A 170 108 500 8.8 6.7 4.3 19.7 19.4

TLM 23 190 120.7 600 12.5 7.5 4.8 23.6 27.6

TLM 24 230 146.1 700 21.9 9.1 5.8 27.6 48.3

TLM 26 305 177.8 780 49.1 12.0 7.0 30.7 108.2

TLM 29 370 235 650 53.3 14.6 9.3 25.6 117.5

TLM 29A 400 270 650 57.8 15.7 10.6 25.6 127.4

TLM 31 445 295 570 64.6 17.5 11.6 22.4 142.4

TLM 32 480 381 590 51.4 18.9 15.0 23.2 113.3

TLM 34 520 403 700 77.2 20.5 15.9 27.6 170.2

TLM 36 595 450 710 110.0 23.4 17.7 28.0 242.5

TLM 39 650 500 800 134.0 25.6 19.7 31.5 295.4

TLM 42 735 600 840 154.0 28.9 23.6 33.1 339.5

Service and Support

Orkot Marine Bea rings ha ve a t ea m of experienced

and highly skil led eng ineers who of fe r a f ull and

complete service t a ilored to your specificreq uireme nts. Som e a spects of this service are:

Recommendations on adapting our bearings to

specif ic environmenta l an d operat ional conditions.

Calculation of bearing dimensions for pre-despatch

or on site machining

Technica l assista nce w ith be a ring insta lla tions

Full technical ba ckup a nd support t hrougho ut t he

service life o f t he b ea ring

24 hour emergency support

This exten sive suppo rt service is com pliment ed by a

comprehensive rang e of t echnical documentat ion andthe Orkot Marine Bearings calculation prog ram.

Web Site

Visit our w ebsite o n: www.orkotmarine.us f o rgen eral and t echnical informa tion on Orkot Marine

Bea ring s produ cts a nd a pplicat ions. You w ill be a ble

to view and download certi f icates, l i terature and

other documents.

World Wide Availability

Orkot Marine Bea ring s distribut ion net w ork is set up

to meet the urgent demands of modern ship repair ing.

Standard Orkot

TLM Ma rine tub es, w hich ca n b eshipped t he same da y, are stocked w orld w ide by local

distribut ors in t he ma jor ship repa iring centres. These

are ba cked up b y ad ditional larg e stocks in our

manufacturing plants.

Our modern, w ell eq uipped fa cil it ies can man ufa cture

specif ic sizes of raw ma terial in bo th t ube a nd sheet

fo rm fo r despat ch w ithin 24 hou rs. They can a lso

supply a full range of finished-machined products

q uickly a nd econo mica lly, including :

Plain b earings

Flanged bearings

Grooved bear ings Staves

Thrust bea rings

Spherical bearings

Wea r ring s

P ads

Strips

Washers

5


Marine Stock Tube Sizes TableTable 3
http://www.orkotmarine.us/http://www.orkotmarine.us/http://www.orkotmarine.us/http://www.orkotmarine.us/http://www.orkotmarine.us/


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6


Standard Production CapacityGuidelines

With our current sta nda rd eq uipment a nd production

processes we a re able to ma nufa cture parts w ithinthe f ollow ing g uidelines. How ever we specialise in

eng ineering solutions so please do not hesita te t o

conta ct us if your req uirement s fal l outside of

these limits.

Tube prod ucts up to 2500mm (98 ) outside d iame ter

a nd 1250mm (49 ) lon g

Sheet s products up to 860mm (33 ) wide a nd

3000mm (118 ) lon g

Rod p roducts up to 200mm (8 ) out side d iame ter

a nd 500mm (19 ) long

Contact Details

Plea se refer to our w eb site fo r the conta ct deta i ls

of your local agent or distributor. Alternatively you

can conta ct o ne of our manufactur ing plants onthe fo llow ing:

Orkot Marine Bearings,Rotherham, South Yorkshire, UK:

Pho ne : + 44 1709 789828

Fa x: + 44 1709 789802

E-ma il: [email protected]

24 hour emerg ency mob ile pho ne: + 44 1709 789840

Orkot Marine Bearings,

Eugene, Oregon, USA:

Pho ne : + 1 541 688 5529

Fax: + 1 541 688 2079

E-ma il: [email protected]

24 hour emerg ency mob ile pho ne + 1 800 546 7568
mailto:%[email protected]:%[email protected]:%[email protected]:%[email protected]:%[email protected]:%[email protected]:%[email protected]


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Rudder Bearings

This section p rovide s gene ral a dvice o n rudd er bea ring

design. It a lso provides the informat ion required to

allow the user to calculate t he ma chining sizes of arudder bea r ing before and af t er f it t ing .

Pag e 24 show s a completed e xample of the Orkot

Marine Bearings calculation fo r you to examine.

Pag e 23 conta ins a b lank for you to complete your

own calculation. Alternatively please feel free to

conta ct your local ag ent, distributor or manuf acturing

plant and w e w ill be happy to a dvise you of t he

ma chining sizes.

A spreadsheet ba sed calculat ion progra m is availab le

upon request .

Prior to carrying out any calculat ion, the fo l low ing

information must be a vailab le: Minimum bearing operating temperature

Approximate a mbient te mperature d uring

machining

Housing a nd shaf t sizes w ith t olerances

Bearing Design Pressure

Orkot TLM Ma rine h a s classificat ion a pprova l for up t o

15N/mm 2 (2,176 lb /in 2) in rudd er bea ring a pplications,

w hile TXM Marine h a s app rova l for up to 10N/mm 2

(1,450 lb s/in 2). Clearly, this is linked to the application

and the other components involved. When looking

only at the properties of Orkot

Marine bea ring s muchhigher loa ds can be susta ined. Orkot Marine b earings

are in use in many o the r applica tions such as deck

cran es, hat ch cover slide pa ds, moo ring systems and

ships sta bilisers operat ing a t bea ring pressures rang ing

fro m 25 u p t o 100 N/mm 2 (3,626 - 14,504 lb /in 2).

Material Selection

Orkot TLM Marine is the preferred m a te ria l grad e fo r

rudde r sto ck, pintle, neck and carrier bea ring s. It

incorpora tes solid lubrica nts w hich ena ble dry running

to e nsure out sta nding w ea r li fe for al l rudder bushes

operat ing ab ove or below the d raf t l ine. The ma terial

w ill operate w ithout lubricat ion a t pressures of 30N/mm 2 (4,351 lb /in 2) for short period s and ha s been

te sted a t p ressures of 14.5 N/mm 2 (2,103 lb /in 2) w ith a

velo city o f 1.3 m /min (4.3 ft /min) fo r 1.5 million cycles

w ith minimum lubrica tion.

Orkot TXM Ma rine is a high perfo rman ce mat erial

w hich exhibits low er fr iction a nd w ea r properties than

our TLM Marine gra de . It is a pproved t o o pera te

w ithout lubrication in rudder bea ring applications and

has been tested, w ith lubrication a ga inst sta inless steel

fo r subma rine ste ering g ea r at 57 N/mm 2 (8,267 lb /in 2)

a t 1 m /min (3.3 ft /min ).

Lubrication

Water, grease or oil can provide bearing lubrication

depend ing on t he a pplicat ion. No a xial groo ves are

required w ith lubricat ed rudder bea ring s. Orkot

TLMMarine rudde r bearings are capa ble of intermitte nt

dry running ag ainst K-Monel , Incone l 625, Stellite ,

duplex stainless a nd suita ble corrosion resistan t

stainless steels.

7

Housing and Shaft Requirements

Housing

The be a ring h ousings interna l dia met er, part icularly on

refits, should be mea sured in at least three po sitions

along its length. At least two measurements should

then be t aken at 90 deg rees to ea ch other in the radial

plane and the resulta nt f igures used t o o bta in theaverag e diame ters of ea ch position. If the ho using is

oval or ta pered Orkot can still be used if the problem is

no t e xcessive (0.1mm per 100 mm or 0.004 per 4 ), th e

ma terial has some elasticity, but it w ill not compensate

for severe w ea r. It should be noted t ha t the bea ring

w ill ta ke the shape of the housing w hen f i t ted w ith a n

interference.

The housing should be provided w ith a n a deq uat e

chamfer to prevent shaving the b ear ing w hen

press fitt ing.

After f i t t ing the bearing should be retained at one

end b y a shoulder and for a dditiona l axial security a

keeper ring ma y be used a t t he o ther. The fo llow ingdiag ram il lustrat es this metho d.

Figure 1: Fitted bearing

Shaft

The sha ft o r liner surfa ce in conta ct w ith a n Orkot

Marine bea r ing w hen lubricated by w ater must be of

corrosion resista nt ma terial to ensure low w ea r.

Suitable ma terials are sea w at er corrosion resista nt

stainless steel, phosphor bronze, gunmetal, Inconel

625 a nd Stellite .

The shaf t should be smoot h, w ithout cutting ed ge s.

The ide a l sha ft surfa ce finish is betw een 0.1 an d 0.8 Ramicromet ers or 4 an d 32 Ra micro inches.


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Design

Wall Thickness

Norma lly in refits, the w a ll thickness of t he be a ring isf ixed b y the shaf t and housing dimensions.

For new bea ring designs the optimum w all thickness

should b e calculat ed as:

0.04 x shaft diameter plus 2 mm (0.08).

Any bea ring design w ith a w all thickness below this

value should a lwa ys be checked by o ur engineering

depa rtment t o ensure it mee ts our minimum

requirements.

It should be noted that w hen an Orkot Marine

bea ring of the optimum th ickness is f it te d into a

housing the interference is ref lected a s a reduction o f

the be arings interna l diam eter af ter f i t t ing, i.e. the

w all thickness before a nd a f ter f i t t ing w ill normally

remain consta nt. Bearings w ith t hicker tha n opt imum

w alls may g ive less bore closure .

Operating Value of "m"

Temp Machining Temperature (C)

(C) 0 5 10 15 20 25 30

0 0.00131 0.00155 0.00178 0.00202 0.00225 0.00249 0.00273-10 0.00178 0.00202 0.00225 0.00249 0.00273 0.00296 0.00320

-20 0.00229 0.00253 0.00277 0.00300 0.00324 0.00347 0.00371

-30 0.00291 0.00311 0.00331 0.00351 0.00371 0.00391 0.00411

Operating

Temp Value

(C) of "c"

0 -0.125-10 -0.125

-20 -0.143

-30 -0.158

Table 4 Table 5

Operating Value of "m"

Temp Machining Temperature (F)

(F) 32 41 50 59 68 77 86

0 0.00131 0.00155 0.00178 0.00202 0.00225 0.00249 0.00273

-10 0.00178 0.00202 0.00225 0.00249 0.00273 0.00296 0.00320-20 0.00229 0.00253 0.00277 0.00300 0.00324 0.00347 0.00371

-30 0.00291 0.00311 0.00331 0.00351 0.00371 0.00391 0.00411

Operating

Temp Value

(F) of "c"

32 -0.00492

14 -0.00492-4 -0.00563

-22 -0.00622

Table 6 Table 7

Bearing Interference

As w ith all polymer bea ring s, the int erference req uired

to h old the b earing in place during operat ion is higher

than that required by meta l bear ings because themod ulus of polymer ma terials is low er.

Ta bles 4, 5, 6 a nd 7 sho w the various values for

m and c tha t a re r equ ir ed to ca l cu la te t he

recommend ed interference fo r Orkot Marine rudde r

bea rings. These values are d epende nt upon the

minimum operat ing temperature of t he bea r ing and

the temperature of the machine shop at t he t ime of

ma chining. These te mpera ture fig ures should be used

in relation w ith these ta bles w hen selecting the va lues

o f m a n d c.

Once these values ha ve been obt ained from th e ta bles

they should be entered in to the fo l low ing equa t ion in

order to calculat e th e req uired interference.

Interference = (m x Housing ID) + c

Once a n interference value ha s been calculated i t can

be ent ered into t he Ma rine Bea ring Calculat ion.

8


10/28


Bearing Clearance

The minimum recomme nde d bea ring clearan ce for an

Orkot Marine rudder bearing can be established using

the gra phs, Figures 2 and 3. The low er line indicate sthe minimum clearances w hich w e recommen d w here

the al ignm ent is go od and housing distortion low . The

upper line is based on typical classification minimum

clearances, for example, Lloyds Register specify 0.002d

+ 1.0mm (0.04" ) but no t less tha n 1.5 (0.06" ) mm fo r

synt het ic bea ring s. Where t he Classification Society

rules are not applied i t is sugg ested th at a clearan ce is

selected f rom betw een these tw o l ines.

Figure 2: Bearing starting clearance in mm

Figure 3: Bearing starting clearance in inches.

The eq uat ions for the slopes on t his graph are a s

fo llow s. These eq ua tions w ill allow you to calculate a

more a ccurate clearan ce f igure.

Metric

Uppe r slope (Typical classificat ion minimum ):

Clea rance = (0.002 x Sha ft Dia met er) + 1.0

Low er slop e (Orkot recommended minimum):

Clea rance = (0.002 x Sha ft Dia met er) + 0.1

Mea n be tw een t he t w o slopes (Typically used in Orkot

Marine Be arings ca lculation s):

Clea rance = (0.002 x Sha ft Diamet er) + 0.55

Imperial

Uppe r slope (Typical classificat ion minimum ):


Low er slop e (Orkot recommended minimum):


Mea n be tw een t he t w o slopes (Typically used in Orkot

Marine Be aring s calculation s):


Once a clearan ce value ha s been calculat ed i t can be

entered into th e Marine Bearing Calculat ion.

Machining Tolerance

The fo llow ing ta bles show the machining to lerances

Orkot

Marine Bearings machine shop can achievew hen ma chining rudd er bea ring s. These can be

substitute d into the calculat ion w ith your ow n

machining to lerance should they dif fer from

those sta t ed .

Once machining tolerance values have been selected

they can be en tered into t he Marine Bearing

Calculation. All of the required elements of the

calculat ion should now be in place an d the f inal

f igures can now be calculated.

Recommended MachiningTolerance OD and ID for Orkot

Marine Rudder Bearings

3.00

2.50

3.50

4.00

2.00

1.50

1.00

0.50

0

0 200 400 600 800100 300 500 700 900 1000 12001100

Recommended by some classification societies

Minimum clearance recommended for Orkot Marine

Shaf t diameter (mm)

Diametralclearnace(mm)

0.10

0.08

0.12

0.14

0.16

0.06

0.04

0.02

0

0 8 16 24 324 12 20 28 36

40 4844

Shaft diameter (inches)

Diametralclearnace(inches)

Recommended by some classification societies

Minimum clearance recommended for Orkot Marine

Diameter OD and IDmm

1 - 100

101 - 300

301 - 500

501 - 900

abo ve 900

Tolerance Bandmm

0.10

0.15

0.20

0.25

0.40

Diameter OD and IDinch

0 - 4

4 - 12

12 - 20

20 - 36

abo ve 36

Tolerance Bandinch

0.004

0.006

0.008

0.010

0.016

Table 8

Table 9

9


11/28

Water Lubricated SternTube Bearings

This section p rovide s gen era l ad vice on stern t ube

bea ring design. It w ill also provide the informationrequired t o a llow the user to calculat e a stern tube

bea rings dimensions befo re and a f ter f i t t ing.

Pag e 25 show s a completed e xample of the Orkot

Marine calculat ion for you to examine. Page 23

conta ins a blan k for you to complete your ow n

calculation. Alternatively please feel free to contact

your local ag ent, d istributor or manuf acturing

plant and w e w ill be happy to a dvise you of t he

ma chining sizes.

Prior to carrying out any calculat ion, the fo l low ing

information must be a vailab le:

Housing a nd shaf t sizes w ith t olerances

Bearing Design Pressure

Wat er lubricat ed propeller shaf t b ea ring s need t o

operate hydro-dynamically, i .e the shaft speed should

be suf f ic ient to generate a w at er f ilm to separate the

sha f t f rom t he be aring. The d esign of these bea ring s is

governed by the length to shaf t diameter ra t io w hich

can vary from 4:1 to 2:1 depend ing on the b ea ring

position a nd upon approval from the classif ication

societ ies. Most classifica tion societies a pply a rat io of

2:1 for Orkot Marine g rad es. Full copies of the

certifica tes are availab le upon req uest or from our

web si te : www.orkotmarine.com

Material Selection

It should be no ted t hat Orkot ma terials are no t

suitable for use in high speed grease or oil lubricated

stern shaf t syste ms.

Orkot TLM Marine is suita ble fo r the m a jority of

w at er lubricated stern tube systems.

Orkot TXM Marine is especia lly suita ble f or low

shaft velocities i.e. na val surfa ce ship an d subma rine

stern shafts.

Shaft Requirements

Orkot Marine be arings can be used w ith most

recog nised shaf t mat erials an d is found to b e

compat ible w ith gunmet al , phosphor bronze, Monel,

Inconel 625, 18/8 sta inless ste el.

If t he b ea ring is subject to a bra sive ingress,

consideration should be g iven to the use of ha rder

shaft liners or carbide coatings. Orkot Marine tends to

improve the surface finish during runn ing. As w ith a ll

bearings subject to the ingress of abrasive particles,

l ife can be reduced. For the stern tub e bea rings of a

vessel operat ing unde r such cond itions a f i ltered w at ersupply is recommen de d.

A sha ft surfa ce finish o f 0.8 micromet ers or 32

microinches Ra is req uired t o red uce bed ding in w ea r.

Design

A number of b ea ring d esign s can be ma nufa ctured

from Orkot Marine grade s for stern tube b ea ring

a pplicat ions. The t ypes in ord er of p opula rity a re

as fo l low s:

Multi Groove Bearing

This convent iona l bea ring de sig n ha s equi-spaced

axial groo ves to a l low w at er to circulat e and cool the

bear ing a nd to enab le debr is to pass through w ithout

causing da ma ge to the shaf t o r bearing. This design

is suita ble fo r most vessels whe re shaf t velocities a re

not h igh .

Twin Groove Bearing

This bea ring ha s tw o large axial grooves at 90 deg rees

to t he stat ic sha f t loa ding posit ion a nd a l low s superior

hydrodynamic performance over a wide range of shaf t

velocities. It w a s de veloped fro m testing Orkot TLM

Marine bearings on a purpose designed shaf t t esting

rig. The d esign a llow s fo r a hydro dyna mic film to

develop a t low shaf t velocit ies reducing fr iction an d

w ea r. Good h ydrodyna mic performance is obt ained

w ith sha ft velocities a s low a s 25 m/min. (82 ft /min).

This de sig n should b e limite d t o a ma ximum 300 mm

(11.8" ) diame ter a nd m ay a lso be used fo r vertical

shaf t w at er pumps for marine use.

Figure 4: Twin Groove Bearing

Special Designs

Special d esigns fo r na val applications tha t incorporate

partial arc segm enta l bearings mounted in split b ronze

housings a re a lso ava ilab le.


0.4W W = 0.055d + 6 (.24" )[d = shaf t d ia .]

R= 0.3d

10
http://www.orkotmarine.com/http://www.orkotmarine.com/http://www.orkotmarine.com/http://www.orkotmarine.com/


12/28


Staves

An a lterna tive b ea ring design uses sta ves machined

from Orkot TLM Ma rine shee t. It shou ld be not ed

tha t in ref i ts the l ignum vita e staves used in somevessels ca n b e ea sily and more e cono mica lly replaced

w ith Orkot TLM Marine mu lti-g roo ve bea rings. Aft er

removing the w orn staves and keeper str ips Orkot

bushes can be machined t o suit the bronze ca rrier in

the w ork shop o r al ternat ively bored insitu.

The length to a diameter rat io o f a n Orkot Marine

grad e stern tube b earing should b e held to 2:1 if

po ssible. Tod a y the m a jority o f classifica tion societ iesallow this as longer bearings increase the problem of

a lign ment . If classification rules require a longe r

bea rings to be used i t is sugg ested tha t t he bea ring

clearance at the forward end for the additional length,

ab ove the 2:1 shaf t to diameter rat io, should be

increased to provide a safet y bea ring . This can red uce

the risk of misa lign ment a nd is illustra ted in figure 6.

Water Flow RateA wa ter f low rate of 0.18 l itres per minute per mm of

shaf t d iamet er is req uired o r 1.21 US g a llons per min

per inch of shaf t d iameter .

Increased bearing diame ter

The a ctual bea ring should be posit ioned

w here the loa d is, hence at the propel ler side

L= 2D

D

Figure 6: Long bearing with increased clearancesafety bearing

11

Figure 5: Coefficient of friction as a function ofshaft speed.

Corfficientoffriction

Shaft Speed (Rpm)

Shaf t diameter= 200mm (8" )

0.14

0.12

0.10

0.08

0.06

0.04

0.02

00 20 4 0 6 0 80 100 120

Multi and twin groove designs can be manufactured as

full or split b ea ring s. Full bea ring s are no rmally fittedw ith a n interfe rence fit. This can b e a chieved b y press

f i t t ing or freeze f i t t ing. If more tha n one b ea ring is

required to be f i t ted into a stern tube, care must be

ta ken to ensure wa ter groo ves are in line.

Where multi piece bea ring s abut, a radial g roove,

similar in size to the bearings longitudinal grooves,

should b e ma chined in both bores a t the a butment .

These grooves ensure tha t an a deq uat e w at er f low

occurs even if the w at er grooves in the a butt ed

bea rings a re not al ign ed correctly.

Split b earings should be assembled w ith an

interference fit, if necessary this can be introduced

using t apered keys.

Orkot ha ve develope d va rious special split b ea ring

designs for Naval applications.


13/28


Table 10: Multi Groove Bearing in mm

Table 11: Multi Groove Bearing in inches

Shaft Size Min Wall Min Min Shaft Number Groove Groove GrooveThickness Interference Clearance of Angle Width Depth

A B B Grooves W D

mm mm mm Degrees mm mm

30 - 60 8 0.15 0.30 4 72.0 8 4

60 - 100 9 0.22 0.41 5 60.0 8 4

100 - 150 10 0.34 0.52 6 51.4 10 6

150 - 200 12 0.43 0.63 7 45.0 10 6

200 - 250 14 0.56 0.74 8 40.0 12 7250 - 300 14 0.70 0.85 9 36.0 12 7

300 - 350 16 0.84 0.96 10 32.7 14 8

350 - 400 16 0.97 1.07 11 30.0 14 8

400 - 450 20 1.11 1.18 12 27.7 16 10

450 - 500 20 1.25 1.29 13 25.7 16 10

500 - 550 22 1.40 1.40 14 24.0 18 11

550 - 600 22 1.50 1.51 15 22.5 18 11

Shaft Size Min Wall Min Min Shaft Number Groove Groove GrooveThickness Interference Clearance of Angle Width DepthA B B Grooves W D

inch inch inch inch Degrees inch inch

1.18 - 2.36 0.315 0.006 0.012 4 72 0.315 0.157

2.36 - 3.94 0.354 0.009 0.016 5 60 0.315 0.157

3.94 - 5.91 0.394 0.013 0.020 6 51.4 0.394 0.236

5.91 - 7.87 0.472 0.017 0.025 7 45 0.394 0.236

7.87 - 9.84 0.551 0.022 0.029 8 40 0.472 0.276

9.84 - 11.8 0.551 0.028 0.033 9 36 0.472 0.276

11.8 - 13.8 0.630 0.033 0.038 10 32.7 0.551 0.315

13.8 - 15.7 0.630 0.038 0.042 11 30 0.551 0.315

15.7 - 17.7 0.787 0.044 0.046 12 27.7 0.630 0.394

17.7 - 19.7 0.787 0.049 0.051 13 25.7 0.630 0.394

19.7 - 21.7 0.866 0.055 0.055 14 24 0.709 0.43321.7 - 23.6 0.866 0.059 0.059 15 22.5 0.709 0.433

Bearing Interference and Clearance

Figure 7: Multi groove bearing for 50 mm (2" Dia.)shaft with bottom groove omitted.

Rad min

D

W

A

To simplify th e bea ring design sizes a re ta bulat ed.

*To improve shaf t running th e bo tt om (6 o'clock)

groove should be omitted.

The w all thicknesses " A" indicated are t he m inimum

recommended.

Bearing to ha ve 3mm x 30 (1/8" x 30) cha mfer on

O/D a nd I/D.

The Orko t Marine Bearings calculat ion sheet ca n b e

used for stern tube calculations.

Warning: Please note that the Orkot MarineBearing calculat ion is set up a s sta nda rd to calculate

rudder bearing dimensions. As such the standard

interference a nd cleara nce f igures given must b e

chang ed t o th ose sta ted in this section.

12


14/28


Machining Tolerance

The fo llow ing ta bles show the ma chining to lerances

Orkot Composites machine shop can achieve when

ma chining stern t ube b ea ring s. These can b esubstituted in the calculat ion w ith your ow n ma chining

tolerance should they d if fer from t hose sta ted.

Warning: Please note that the Orkot Marine

Bearing calculation is set up a s sta nda rd to calculate

rudder bearing dimensions. As such the standard

machining tolerance f igures given must be chang ed

to tho se stat ed in th is section.

Once ma chining t olerance values have bee n selected

they can be ent ered into the Ma rine Bearing

Calculat ion. All of the required element o f t he

calculation should no w be in place a nd t he f inal

f igures can now be calculated .

Table 12: Recommended MachiningTolerance OD and ID for Orkot

Propeller Shaft Bearings

Note:

1. These t oleran ces a re fo r guida nce on ly, reducing

them w ill reduce the maximum clearance af ter

f i t t ing. It is importa nt tha t out of roundne ss

tolerance is ma intained w hen chocking

compounds are used.

2. Propeller sha f t b ea rings are long er tha n rudder

bea rings; longer leng ths require larger to leran ces.

Diameter OD and ID Tolerance Bandmm mm

1 - 100 0.10

101 - 300 0.20

301 - 500 0.30

501 - 900 0.40

Diameter OD and ID Tolerance Bandinches inches

0 - 4 0.004

4 - 12 0.008

12 - 20 0.012

20 - 36 0.016

Table 13

13


15/28

Fitting Methods

Orkot Marine Bearings can b e f i t ted using an y one of

the fo llow ing methods:

Freeze fitting

Me tho d 1: Using liq uid nit ro g en

(immersion method)

Me tho d 2: Using liq uid nit ro g en

(vapour method)

Me tho d 3: Usin g d ry ice a nd alco ho l

Press fitting

Bonding

Our preferred met hod is to freeze f i t using l iq uid

nitrogen. How ever descriptions of al l method s can be

found in this section.

Freeze Fitting

This is a f a st an d ef ficient a ssemb ly met hod fo r an

Orkot Marine bea ring . The th erma l properties of th e

mater ia l a l low a g ood clearance betw een the bea r ing

and housing w hen f rozen and t he mater ia l does not

become brit t le at cryoge nic tempera tures.

Note:

Extreme care should be ta ken w hen using l iq uid

nitrogen t o a void severe burns. Adeq uat e venti lat ion

should be provided because oxygen is depleted w hen

g assing occurs in con fined spaces, suppliers of t heproducts will provide a da ta sheet ad vising on i ts use.

Method 1:

Using liquid nitrogen (immersion method)

A sugg ested procedure for met hod 1 is as fol low s:

1. Check the od o f t he b ear ing in a t l east 3 posit ions

around the top , middle and bot tom (a t o ta l o f 9

mea surements) making a no te of the largest

f igure recorded .

2. Check the id o f the ho using in a t least 3 posit ions

around the top , middle and bot tom (a t o ta l o f 9mea surements) making a not e of the smallest

f igure recorded .

3. P rov ide an insu la ted con ta iner capab le o f

w ithsta nding a t empe rat ure of -197C (-320F) a nd

large enoug h to a ccommoda te the bea r ing being

f it ted w ith enoug h c learance on the od to

fa cil ita te t he insertion and removal of the b ea ring.

4. P lace the b earing inside the conta iner and m ake

effo rts to reduce its int erna l volume. This can b e

don e by sealing of f un-used a reas of the cont ainer

or filling a ny voids w ith roug h cut t imbers. This

w il l reduce the amo unt of l iquid nitrog en tha t w ill

be required.

5. Cov er the b ear ing w ith the liqu id n it r ogen and

mainta in this level for the durat ion of the

procedure. The nitrog en level will consta nt ly drop

as the l iquid boils, turns to ga s and escapes to the

at mosphere. Use a n insulated l id t o cover the

conta iner when possible. Once the l iq uid stops

boiling and sett les do w n to a simmer then t hebea ring can be l i f ted slightly from the l iq uid a nd

the upper od measured to check for sufficient size

reduction. If this has not been a chieved the n the

bea ring can be returned to the l iquid fo r 10 to 20

minutes and then checked again

6. O nce suf f icien t c lear ance b e tw een the b ear ing a nd

the ho using has been a chieved then t he bea ring

can be removed f rom the nit rogen a nd

transported to the housing for f i t t ing.

7. The appar a tus used to t r ansport the b ear ing a f t e r

freezing w ill need to b e resista nt t o the cryoge nic

tempera tures they w ill encounter (e.g. polyester

sl ing s) and suitable to support the w eights

involved.

8. Ensure tha t the reduced b ear ing can b e loca ted

q uickly an d ea sily. Once it come s into cont act w ith

an y conductive surfaces the rate w ith w hich i t w ill

return t o its original dimen sions increa ses g reat ly.

9 . Slide the bea r ing in to posit ion , ensuring tha t i t is

held th ere w hile its tem pera ture no rmalises. Once

the b earings surfaces ha ve cleared of the ice that

forms on them during no rmalisat ion then a ny

supports can be removed.

Method 2:

Using liquid nitrogen (vapour method)

Orkot bear ings can be f i t ted w ithout a metal

conta iner by vaporising the l iq uid nitrog en w ithin the

bea ring . This uses less liquid n itrog en a nd is the refo re

safer a nd less expensive tha n t he immersion meth od.

P lease note how ever that the ra te o f bear ing

contraction is a lot low er using this metho d w hen

compared t o t he immersion metho d. As such the

freezing procedure w ill take a lot long er

A sugg ested procedure for met hod 2 is as fol low s:

1. Check the od o f the b ear ing in a t leas t 3 posit ionsaround the top , middle and bot tom (a to ta l o f 9

mea surement s) making a no te of t he largest

f igure recorded .

2. Check the id o f the ho using in a t least 3 posit ions

around the top , middle and bot tom (a to ta l o f 9

mea surement s) making a not e of the smallest

f igure recorded .

3. P re p a re a p ly w o o d d isk w i t h a n o d h a lf w a y

b e tween tha t o f the od a nd the id o f the b ea r ing .

Drill a 15 /20mm d iame ter ho le in th e midd le of

th is disk.

4. P lace the b ear ing on a smoo th , f la t , none por oussurface. Sea l the joint bet w een th is an d th e id of

the b earing w ith si licone sealan t.


14


16/28


5. Manufacture a s imple lance f rom 10 mm (.40" ) or

simila r coppe r tube, drill a pproximat ely tw ent y 1

mm (.40" ) diamet er holes throug h bot h w alls of

the pipe and f i t a bleed valve to t he pipe to cont rol

the f low of l iq uid nitrog en. Ensure tha t you sealthe open end o f the lancee.

6. P lace the p lywood d i sk on top o f the b ear ing ,

and connect the lance to a pressurised l iq uid

nit rogen ta nk.

7. Turn the valves to control the f low on ni t rogen

until vapour can be seen escaping, under pressure

from th e lance. If l iquid sta rts to exit t he lance the n

the f low should b e reduced unt i l i t stops.

8. P lace the lance though the ho le in the cen t re o f

the d isk and into t he bea ring . Wrap the b earing in

an insulating b lanket to reduce energy loss from its

surface.

9. During the procedure the nitrogen f low w ill need to

be monitored a nd a djusted f rom time to time.

Measure the od at the t op o f t he bea ring periodically.

10. Once suff icient c learance betw een the bear ing and

the ho using has been a chieved then t he bea ring

can be transported to the housing for f i t t ing.

11. The appa ratus used to tran sport the bearing af ter

freezing w il l need to be resista nt t o t he cryogenic

tem perat ures the y w ill encount er (e.g. po lyester

slings) an d suita ble to support t he w eight s involved.

12. Ensure tha t the reduced bea r ing can be located

q uickly an d ea sily. Once it comes int o cont a ct w ith

any cond uctive surfaces the rat e w ith w hich i t w ill

return t o its original dimensions increases grea tly.

13. Slide t he bea ring into posit ion, ensuring t hat i t is

held th ere w hile its te mpera ture no rmalises. Once

the b ea rings surfa ces ha ve cleared of the ice that

forms on th em during no rmalisat ion then an y

supports can be removed.

Method 3:

Using dry ice and alcohol

Freeze fitting using dry ice and alcohol will onlyprovide the required clea rance w hen using very l ight

interferen ces. As such it is rarely a viab le met hod in its

ow n righ t a nd w ill of ten a lso req uire press f it t ing

Fitting with Hydraulic Press orCentre Pull Jacks

If a bearing is to be press fitted, installers should ensure

tha t they ha ve equipment a vailable to deliver ad equa te

force to press the bea ring fully into the housing . The

ease of fitting will vary dependent on the finish of the

housing a nd t his should b e considered w hen calculat ing

the f orce req uired. When press fitting a bea ring it is

important tha t i t is in l ine a nd square w ith the borebefore the operation beings, an a deq uate chamfer on

the h ousing w ill prevent shaving of t he bush.

The d iag ram (Figure 8) illustrat es a m eth od of

ensuring th e bush is square b efore t he f i t t ing starts.

Figure 8: Method of ensuring the bush is squarebefore the fitting starts.

Housing-1mm 20mm

step

15

Tonnes

Diameter (mm)

Bearing opera t ing tempera ture:

-30C -10C

-20C 0C60

50

40

30

20

10

0

150 250 350 450 550 650 750 850100 200 300 400 500 600 700 800

Figure 9: Fitting force (Tonnes)

Tons

Diameter (inches)

Bearing opera t ing tempera ture:

-22F -14F

-4F 32F

66

55

44

33

22

11

0

6 10 14 18 22 26 3 344 8 12 1 6 20 2 4 28 32

Figure 10: Fitting force (Tons)

Figures 9 and 10 show the typical fitting force of a

bea ring, length/diamet er rat io 1:1

An init ial force to m ove the be aring ma y be higher

than given in the graph

The a ctual force w ill vary depe ndent on t he conditionof t he housing, leading chamfers and the length/

diameter ratio.


17/28

Bonding

The met hod of f ixture w ill depend upo n the design

employed, how ever the key point to be empha sised

here is tha t in ad dition to t raditional mechanicalfixing, Orkot ma terials can be bo nded t o bo th i tself

and meta llic substrates. Plea se no te t ha t i f the

a ssemb ly is to e xperience in excess of 60-70C th en

interference f i t t ing should be replaced w ith

adhesive bonding.

Numero us a dhe sives a re comp a tible w ith Orkot a nd

have b een t ested w ithin our labo rato ry facil it ies.

Generally the m ost suita ble a dhesives are:

Epoxies.

Acrylics .

Cyanoacrylates. Polyurethanes.

The f ollow ing is a list of a dhe sive suppliers w hose

products ha ve been tested a nd a re approved for use

w ith Orkot materials:

Araldite

Belzona

Bisonite

Chockfast

Loctite

Permabond

For specif ic deta i ls of bo nding a ge nts and conditions

please conta ct our Technica l dep a rtmen t.

General terms and preparat ions are req uired

irrespective of the ad hesive to be used.

Terms:

The bo nding a gen t is referred t o a s the ad hesive.

The ma terial/surfa ce to w hich t he Orkot is to be

bond ed is the substrat e.

The d ista nce betw een the Orkot and the substra te

is the g ap.

The a bili ty of the ad hesive to bridge and f i ll the g ap

is the g a p fill .

Preparations:

Suitable substrates are Orkot materials themselves

a nd various met a ls (including stainless ste el).

Pla stics such a s polyethylene , po lypropylene,

polycarbon a te, PVC, PTFE are unsuita ble substra tes

for bonding to Orkot materials.

The key to e ffe ctive a dhe sion is in the prepa rat ion

of the substra te a nd the ma ter ia l to be bo nded.

Ensure no bo und a ry la yers such a s oxides or g rea se

are present. Degrea se w ith a suitable solvent

ensuring local health a nd saf ety g uidelines are

follow ed. Orkot can be deg reased by using a q uick

w ipe with a solvent such a s acetone, but exposure to

the solvent must be kept brief so a s not to a tta ck

the Orkot material. Oxides can be removed by use

of f ine a brasive paper or wire w ool.

Roug hen t he surfa ce. Idea lly w here meta ls are

involved use shot b lasting. Ensure a ny rema ining

particulat es are removed from t he surface. Generally

the slight ly fibrous surfa ce of Orkot does not

require roughening , thoug h the use of ab rasive

paper is accepta ble so long as a ny dust is removed.

The a ssembled components ma y need support w hile

the a dhe sive sets. This cure time w ill va ry w ith t he

condition s und er w hich the a dhe sive is used.

Typica lly a rule o f t humb is th a t t he cure t ime w ill

half for every 10C increase in temperature.

In terms of assembly, avoid butt joints in favour oflap, so t hat loa ds applied t o t he a dhesive joint w ill

a ct a cross the a ssemb ly in shea r.


16


18/28


17

Machining Instructions

General

Orkot mat erials are read ily ma china ble byconventiona l machine shop t echniq ues. As a g eneral

guide, methods used for brass, aluminium or lignum

vita e w ill apply for Orkot materials. It is preferable to

use tung sten carbide t urning too ls w ith cutting speeds

of 5.5 metres (19 feet ) per second . Orkot materials

must be machined d ry w ithout the use of coolant .

Turning

Tungsten carbide too ling o f the b utt w elded type

using K20 gra de ca rbide is suita ble fo r most

a pplicat ions. If carbide inserts are used, t hen

aluminium g rade s with high po sit ive rates g ive be st

results e.g . Plan see g ra de H10T, Sand vik H10A or

H13A, Mit sub ishi HTI10.

For hea vy wa ll thickness, the internal and externaldiamet ers should be ma chined to get her to reduce

vibration.

No asbestos is used in the m an ufa cturing o f Orkot

Marine an d the ma terial is complete ly non t oxic. It is

however advisable to use adequate dust extraction

w hen ma chining. If una vailab le, operat ors should w ea r

dust p a rticle ma sks.

For small volume w ork and machining of chamfers,

radii and o ther forms, then high speed steel gives

go od results, but to ol li fe is shorter than w ith

tungsten carbide.

Cutting Angle for Tools

Figure 11: Turning and boring Figure 12: Parting off

5

10

15

5

5

5- 20

R 1-2mm (0.04 - 0.08 inch)

TURNING

BORING

PARTING OFF

3- 5

5

3

3 3

3

Diameter (mm) Rpm

0 - 50 2100

50 - 100 1000

100 - 150 700

150 - 200 550

200 - 300 350

300 - 400 250

400 - 500 200

500 - 600 175

600 - 700 150

700 - 800 130

800 - 900 120

900 - 1000 100

Diameter (inch) Rpm

0 - 2 2100

2 - 4 1000

4 - 6 700

6 - 8 550

8 - 12 350

12 - 16 250

16 - 20 200

20 - 24 175

24 - 28 150

28 - 32 130

32 - 36 120

36 - 40 100

Table 14: Speeds in mm Table 15: Speeds in inches


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Type of Roughing Finishing Unitmachining

Turning 0.7 0.25 mm/rev

Bo ring 0.5 0.20 mm/rev

Pa rt ing 0.4 0.20 mm/rev

Type of Roughing Finishing Unitmachining

Turning 0.028 0.010 inch/rev

Boring 0.020 0.008 inch/rev

Pa rt ing 0.016 0.008 inch/rev

Table 16: Feed Rates in mm Table 17: Feed Rates in inches

Grooving

Orkot mat erials can be read ily grooved on a lathe,

sha ping, mill ing or bo ring ma chine w ith a 90 deg ree

machining h ea d. For most one o f f a pplicat ions a lat he

is ad eq uat e. A sharp high speed steel too l ground to

the correct f orm should b e clam ped in a long b oring

bar w ith a three degree c learance ground on the s ide

of th e too l . No to p clearance is required.

The chuck may b e ma rked fo r the correctly spaced

number of g rooves an d ea ch groove shape d in turn.

A 0.2 mm (0.008" ) dep th o f cut should be used , for

long bea rings a stead y may be required. The ma chine

fa st t raverse, (w ith the spindle locked) can of t en b e

used . Linea r spee ds up t o 10 m/min o r 30 fe et /min

can be a chieved.

Revolutionsperminute(Rpm)

Diame ter (inches)

2750

2500

2250

2000

1750

1500

1250

1000

750

500

250

00 4 12 20 28 36 44

2 8 16 24 32 40 48

Revolutionsperminute(Rpm)

Diameter (mm)

2750

2500

2250

2000

1750

1500

1250

1000

750

500

250

00 100 300 500 700 900 1100

50 200 400 600 800 1000 1200

Figure 13: Machining Speeds as a function of Rpmand diameter (mm)

Figure 14: Machining Speeds as a function of Rpmand diameter (inches)

Drilling

Orkot ma te ria ls a re ea sily drilled u sing either

conventional high speed steel or carbide tipped drills.

The follow ing speed a nd fe eds are suggested:

Drill Diameter Speed Feedmm Rpm mm/min

5 1600 300

10 800 400

15 600 400

20 400 400

25 350 400

30 300 400

Drill Diameter Speed Feedinch Rpm inch/min

0.2 1600 12

0.4 800 16

0.6 600 16

0.8 400 16

1.0 350 16

1.2 300 16

Table 18: Speeds and Feeds by Drilling Table 19: Speeds and Feeds by Drilling

Depth of Cut

Ro ug hing 10mm o r 0.4inch

Finishing 3mm or 0.12inch

Sma ller cuts may lead to too ls rubbing , causing w ea r

w hich prod uces excessive he a t b uild up in t he

f inished pa rt .


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Health and Safety Data

1. PRODUCT AND COMPANY IDENTIFICATION

Product name : Orkot a nd /or Luyt ex

Suppliers : Orko t Composites Orko t Co mpo sit es

Bra dma rsh Business Pa rk 2535 Pra irie Ro a d

Ro therha m Eug ene

S60 1BX Oreg o n, 97402

Unit ed King d o m USA

Emergency telephone number : + 44 1709 789800 + 1 541 688 5529

2. COMPOSITION / INFORMATION ON INGREDIENTS

General Description : Fibre reinforced plastic material

Information on ingredients : Ma y cont a in Polyeste r/a ram id fibres,

po lyeste r/epo xy resin, ptf e, molybd enu m

disulphide, graphite, calcium carbonate

3. HAZARDS IDENTIFICATION

Physical/chemical hazards : None known

Human health hazards : None know n, avoid breathing m achining d ust

4. FIRST-AID MEASURES

Inhalation : Fresh air, seek medical advice if irritation develops

Ingestion : Wash out m out h w ith w at er, seek medical ad vice

Skin contact : Not app licable

Eye contact : Irrigate w ith appropriat e eye w ash

5. FIRE-FIGHTING MEASURES

Suitable extinguishing media : Wat er, foa m, carbon d ioxide, dry pow der

Not Suitable extinguishing media : Not app licable

Hazardous decomposition products : Carbon , carbon oxides

Protection of fire fighters : Use breathing apparatus


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6. ACCIDENTAL RELEASE MEASURES

Personal precautions : Filter m a sk fo r dust (ma chining)

Environmental precautions : Avoid d ispersion of dust (ma chining)

Methods for cleaning up : Tran sfer into suita ble cont a iners fo r disposal

7. HANDLING AND STORAGE

Handling : Observe g ood industr ial safet y a nd hygiene practice.

Storage : Store in a cool, dry place out of direct sunlight

Recommended packaging : Pape r, ca rd, plastics, w oo d

8. EXPOSURE CONTROLS / PERSONAL PROTECTION

Engineering measures : When machining use local exhaust

ventilation. Collect dust for disposal

Machined sw arf is f lamma ble

Hygiene measures : Avoid b reath ing ma chined dust.

Occupational exposure limits

Chemical name : Dust

OEL (UK) : < 10 m g /m 3 8 hou r TWA to t. inh a lab le dust

< 5 mg /m 3 8 hour respira ble d ust

Personal protective equipment

Respiratory system : Dust mask, type FFP1 minimum

Skin and body : Work clot hing

Hands : Not applicable

Eyes : Safet y go gg les when machining

Other protective equipment : Not applicable

9. PHYSICAL AND CHEMICAL PROPERTIES

Physical state : Solid

Colour : Va ria ble w hite, b lack, grey, blue,

turquoise, green (compound dependent)

Odour : Wea k, cha racteristic

Melting point : Does not melt

Bulk density : 1200 1450 kg /m 3

Solubility in water : Insoluble

pH : Not applicable

Flash point : Not applicable

Explosion properties : As w ith a ll du sts a risk of e xplosion exists in

Restricted environm ent s


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10. STABILITY AND REACTIVITY

Stability : Stable

Conditions to avoid : None know n

Materials to avoid : None know n

Hazardous reactions : None know n

Hazardous decomposition products : Decompo sition doe s not occur under

recommended storag e a nd ha ndl ing

11. TOXICOLOGICAL INFORMATION

Inhalation : Inha lation of dust ma y cause irri tat ion t o respirato ry tract

Acute toxicity Oral : None know n

Skin irritation : None know n

Eye irritation : Dust may cause irritation

Other information : No know toxicological ef fects are

associat ed w ith this mat erial

12. ECOLOGICAL INFORMATION

Persistence/degradability : This ma terial is not read ily biode gra da ble

Ecotoxicity : No kno w n ecot oxicity exists

Other information : Not applicable

13. DISPOSAL CONSIDERATIONS

Waste of residues : Disposal in a ccorda nce with na tiona l and local regulations

Contaminated packaging : Packag ing can be recycled Cleaning ag ent - w at er

14. TRANSPORT INFORMATION

National transport regulations (UK) : Not applicable

15. REGULATORY INFORMATION

Classification according to EU : This prod uct do es not ha ve to be classified

Regulations 67/548/EEC-88/379/EEC

Safety phrases : Avoid breat hing ma chining d ust

Contains : Not applicable

National regulationsUnited Kingdom : No additional national regulations are known

to the supplier


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16. OTHER INFORMATION

This safe ty da ta sheet is ba sed on Orkot Composites present know ledge and experience, a nd is intend ed t o serve

as a guide for safe handling of the product regarding to health and environmental aspects.The informa tion g iven in this data sheet w as ob ta ined from sources w e b elieve are reliable. The informa tion is,

how ever, provided w ithout any representat ion or w arrant y, expressed or implied, rega rding i ts accuracy or

correctness.

The conditions or metho ds of ha ndling, storag e, use a nd d isposal of the prod uct are beyond our cont rol an d ma y

be be yond our know ledg e. For this, a nd o the r rea sons, w e do n ot a ssume responsibility a nd expressly disclaim

liab ili ty for loss, dam ag e or expense a rising o ut of or in an y w ay connected w ith the ha ndling, storag e, use or

disposal of t he product.


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Rudder / Stern Shaft Bearing CalculationOrkot Marine Bearings, Bradmarsh Business Park, Rotherham, S60 1BX

Phone: +44 1709 789800 Fax: +44 1709 789802. E-mail: [email protected]

Company : Date :

Contact : Phone :

Vessel Name : Fax :

Reference Number : Application:

All measurments are in mm unless otherwise stated.

Housing I/D Max (mm) Shaft O/D Max (mm)

Housing I/D Min (mm) Shaft O/D Min (mm)

Operating Temp (Degrees C) Machining Temp (Degrees C)

Calculation Checks Clearance Recommended by Some

OK Classification Societies

OK Min Clearance Recommended by OrkotLtd

Min Interference (mm) * Min Clearance (mm) * (Mean of Above)

Manual Overide Manual Overide

M/C Tolerance (O/D) (mm) ** M/C Tolerance (I/D) (mm) **

Manual Overide Manual Overide

(A) Housing I/D Max + Interference Min = Bearing O/D Min (A)

+ =

(B) Bearing O/D Min (A) + M/C Tolerance (O/D) = Bearing O/D Max (B)

+ =

(C) Shaft O/D Max + [Bearing O/D Max (B) - Housing I/D Min] + Min Clearance = Bearing I/D Min (C)

+ [ - ] + =

(D) Bearing I/D Min (C) + M/C Tolerance (I/D) = Bearing I/D Max (D)

+ =

(E) Bearing I/D Min (C) - [Bearing O/D Max (B) - Housing I/D Min] = Bearing I/D Fitted Min (E)

- [ - ] =

(F) Bearing I/D Max (D) -[Bearing O/D Min (A) - Housing I/D Max] = Bearing I/D Fitted Max (F)

- [ - ] =

(G) Fitted Bush I/D Min (E) - Shaft O/D Max = Fitted Clearance Min (G)

- =

(H) Fitted Bush Max (F) - Shaft O/D Min = Fitted Clearance Max (H)

- =

* These automatic figures are the standard clearances and interference's for Orkot rudder bearings and can be overriden in the boxes provided if requiredFor Stern tube bearings override these with the figures shown on page 16 of Orkot's Engineering Manual (v 3.2)

** These figures apply to Orkot's machining processes. If your process tolerances are different then override them in the box provided.

Copyright Polymer Sealing Solutions 2002This information is confidential and is supplied on the express condition that it shall not be lent or copied or reproduced or disclosed to any other person in whole or in

part without the written permission of Orkot Composites, Bradmarsh Business Park, Rotherham, U.K.

Orkot Composites, Bradmarsh Business Park, Rotherham, S601BX, England.

Phone: ++44 (0)1709 789828. Fax: ++44 (0)1709 789802. 24hr Emergency Line: ++44 (0)1709 789840


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Company : Orkot Marine Bearings Date : 10-Mar-03

Contact : Phil Ryde Phone :

Vessel Name : Fax :

Reference Number : Application: Rudder Bearing Example


Housing I/D Max (mm) 550.120 Shaft O/D Max (mm) 500.030

Housing I/D Min (mm) 550.050 Shaft O/D Min (mm) 499.980

Operating Temp (Degrees C) -10 Machining Temp (Degrees C) 20


OK Classification Societies 2.00

OK Min Clearance Recommended by OrkotLtd 1.10

Min Interference (mm) * 1.38 Min Clearance (mm) * (Mean of Above) 1.55

Manual Overide 1.38 Manual Overide 1.55

M/C Tolerance (O/D) (mm) ** 0.25 M/C Tolerance (I/D) (mm) ** 0.25



550.12 + 1.38 = 551.50


551.50 + 0.25 = 551.75


500.03 + [ 551.75 - 550.05 ] + 1.55 = 503.28


503.28 + 0.25 = 503.53


503.28 - [ 551.75 - 550.05 ] = 501.58


503.53 - [ 551.50 - 550.12 ] = 502.15


501.58 - 500.03 = 1.55


502.15 - 499.98 = 2.17








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25



Company : Orkot Marine Bearings Date : 10-Mar-03

Contact : Phil Ryde Phone :

Vessel Name : Fax :

Reference Number : Application: Stern Tube Bearing Example


Housing I/D Max (mm) 252.450 Shaft O/D Max (mm) 198.940

Housing I/D Min (mm) 252.320 Shaft O/D Min (mm) 198.850

Operating Temp (Degrees C) -10 Machining Temp (Degrees C) 20


OK Classification Societies 1.40

OK Min Clearance Recommended by OrkotLtd 0.50

Min Interference (mm) * 0.56 Min Clearance (mm) * (Mean of Above) 0.95


M/C Tolerance (O/D) (mm) ** 0.15 M/C Tolerance (I/D) (mm) ** 0.15



252.45 + 0.43 = 252.88


252.88 + 0.20 = 253.08


198.94 + [ 253.08 - 252.32 ] + 0.63 = 200.33


200.33 + 0.20 = 200.53


200.33 - [ 253.08 - 252.32 ] = 199.57


200.53 - [ 252.88 - 252.45 ] = 200.10


199.57 - 198.94 = 0.63


200.10 - 198.85 = 1.25








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This information in this manual is based on many years of experience in the manufacture and application of Orkot Composites products.

However, unknown parameters and conditions may restrict general statements during usage. It is vital that customers satisfy themselves as to

the suitability of individual products through adequate testing. For this reason, and due to the wide range of applications of our products,

Smiths Group plc and Orkot Composites can accept no liability as to the suitability or correctness of our general recommendations in

individual cases. For specific operating conditions please consult your Orkot

Composites Technical representative.

The application limits for pressure, temperature and speed given in this catalogue are maximum values determined in the laboratory. During

practical applications it should be remembered that due to the interaction of the operating parameters, the maximum values must be set

correspondingly lower. For exceptional operating conditions, please contact us.

This edition supersedes all previous brochures.

Smiths Group Plc / Orkot Marine Bearings 2003. All rights reserved.

This brochure, or any part thereof, may not be reproduced without our permission.

Non Smiths Group trade marks are referred to for technical advice only and do not express any preference to the use of these products. The

genuine rights and liability of the owners of these trade marks are applicable.

Araldite is a trade mark of Ciba-Geigy.

Bisonite is a trade mark of the Bolton Group.

Belzona is a trade mark of Belzona Molocular Ltd.

Chockfast is a trade mark of ITW Philadelphia Resins Corporation.

Epocast is a trade mark of Springer Marine+Industrial Services GmbH

Inconel is a trade mark of INCO Alloys International, Inc.

Loctite is a trade mark of Loctite Corporation.

Orkot is a trade mark of Polymer Sealing Solutions Ltd.

Permabond a trade mark of Permabond Europe, a division of National Starch & Chemical.

Stellite is a trade mark of Deloro Stellite.


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North & South America

Orkot Composites

2535 Prairie Roa d

Eugene

Oregon, 97402

USA

Tel: +1 (541) 688 5529

Fax:+1(541)6882079

Europe, Africa, Asia

Orkot Composites

Bradmarsh Business Park

Rotherham

S60 1BX

United Kingdom

Tel: +44 (0)1709 789 828

Fax: +44(0)1709789802

For f urther info rma tion visit: www.orkotmarine.us
http://www.orkotmarine.us/http://www.orkotmarine.us/http://www.orkotmarine.us/http://www.orkotmarine.us/

4 orkot marine manual

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