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7/26/2019 4 Orkot Marine Manual
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Engineering ManualVersion 4.0
7/26/2019 4 Orkot Marine Manual
2/28
1
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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Orkot Marine BearingsEngineering Manual for Rudder and Water Lubricated Propeller Shaft Bearings
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
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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
Orkot Marine BearingsEngineering Manual for Rudder and Water Lubricated Propeller Shaft Bearings
Marine Stock Tube Sizes TableTable 3
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Orkot Marine BearingsEngineering Manual for Rudder and Water Lubricated Propeller Shaft Bearings
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
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Orkot Marine BearingsEngineering Manual for Rudder and Water Lubricated Propeller Shaft Bearings
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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Orkot Marine BearingsEngineering Manual for Rudder and Water Lubricated Propeller Shaft Bearings
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
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Orkot Marine BearingsEngineering Manual for Rudder and Water Lubricated Propeller Shaft Bearings
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 ):
Clea rance = (0.002 x Sha ft Diamet er) + 0.04
Low er slop e (Orkot recommended minimum):
Clea rance = (0.002 x Sha ft Diamet er) + 0.004
Mea n be tw een t he t w o slopes (Typically used in Orkot
Marine Be aring s calculation s):
Clea rance = (0.002 x Sha ft Diamet er) + 0.022
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
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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.
Orkot Marine BearingsEngineering Manual for Rudder and Water Lubricated Propeller Shaft Bearings
0.4W W = 0.055d + 6 (.24" )[d = shaf t d ia .]
R= 0.3d
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Orkot Marine BearingsEngineering Manual for Rudder and Water Lubricated Propeller Shaft Bearings
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.
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Orkot Marine BearingsEngineering Manual for Rudder and Water Lubricated Propeller Shaft Bearings
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.
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Orkot Marine BearingsEngineering Manual for Rudder and Water Lubricated Propeller Shaft Bearings
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
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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.
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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.
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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.
Orkot Marine BearingsEngineering Manual for Rudder and Water Lubricated Propeller Shaft Bearings
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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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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 : Orkot Marine Bearings Date : 10-Mar-03
Contact : Phil Ryde Phone :
Vessel Name : Fax :
Reference Number : Application: Rudder Bearing Example
All measurments are in mm unless otherwise stated.
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
Calculation Checks Clearance Recommended by Some
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
Manual Overide 0.25 Manual Overide 0.25
(A) Housing I/D Max + Interference Min = Bearing O/D Min (A)
550.12 + 1.38 = 551.50
(B) Bearing O/D Min (A) + M/C Tolerance (O/D) = Bearing O/D Max (B)
551.50 + 0.25 = 551.75
(C) Shaft O/D Max + [Bearing O/D Max (B) - Housing I/D Min] + Min Clearance = Bearing I/D Min (C)
500.03 + [ 551.75 - 550.05 ] + 1.55 = 503.28
(D) Bearing I/D Min (C) + M/C Tolerance (I/D) = Bearing I/D Max (D)
503.28 + 0.25 = 503.53
(E) Bearing I/D Min (C) - [Bearing O/D Max (B) - Housing I/D Min] = Bearing I/D Fitted Min (E)
503.28 - [ 551.75 - 550.05 ] = 501.58
(F) Bearing I/D Max (D) -[Bearing O/D Min (A) - Housing I/D Max] = Bearing I/D Fitted Max (F)
503.53 - [ 551.50 - 550.12 ] = 502.15
(G) Fitted Bush I/D Min (E) - Shaft O/D Max = Fitted Clearance Min (G)
501.58 - 500.03 = 1.55
(H) Fitted Bush Max (F) - Shaft O/D Min = Fitted Clearance Max (H)
502.15 - 499.98 = 2.17
* 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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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 : Orkot Marine Bearings Date : 10-Mar-03
Contact : Phil Ryde Phone :
Vessel Name : Fax :
Reference Number : Application: Stern Tube Bearing Example
All measurments are in mm unless otherwise stated.
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
Calculation Checks Clearance Recommended by Some
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
Manual Overide 0.43 Manual Overide 0.63
M/C Tolerance (O/D) (mm) ** 0.15 M/C Tolerance (I/D) (mm) ** 0.15
Manual Overide 0.20 Manual Overide 0.20
(A) Housing I/D Max + Interference Min = Bearing O/D Min (A)
252.45 + 0.43 = 252.88
(B) Bearing O/D Min (A) + M/C Tolerance (O/D) = Bearing O/D Max (B)
252.88 + 0.20 = 253.08
(C) Shaft O/D Max + [Bearing O/D Max (B) - Housing I/D Min] + Min Clearance = Bearing I/D Min (C)
198.94 + [ 253.08 - 252.32 ] + 0.63 = 200.33
(D) Bearing I/D Min (C) + M/C Tolerance (I/D) = Bearing I/D Max (D)
200.33 + 0.20 = 200.53
(E) Bearing I/D Min (C) - [Bearing O/D Max (B) - Housing I/D Min] = Bearing I/D Fitted Min (E)
200.33 - [ 253.08 - 252.32 ] = 199.57
(F) Bearing I/D Max (D) -[Bearing O/D Min (A) - Housing I/D Max] = Bearing I/D Fitted Max (F)
200.53 - [ 252.88 - 252.45 ] = 200.10
(G) Fitted Bush I/D Min (E) - Shaft O/D Max = Fitted Clearance Min (G)
199.57 - 198.94 = 0.63
(H) Fitted Bush Max (F) - Shaft O/D Min = Fitted Clearance Max (H)
200.10 - 198.85 = 1.25
* 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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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/