ML20100P228

Intervenor Exhibit I-38,consisting of Iacs Rules for Calculation of Crankshafts for Diesel Engines & Tdi 840305 Memo Re R-46 Crankshafts

ML20100P228
Person / Time
Site:	Shoreham File:Long Island Lighting Company icon.png
Issue date:	10/01/1984
From:	Yang R TRANSAMERICA DELAVAL, INC.
To:	Gregory Trussell TRANSAMERICA DELAVAL, INC.
References
OL-I-038, OL-I-38, NUDOCS 8412140074
Download: ML20100P228 (18)

Text

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Rules for the Calcalat ion of Cranamafts for Diesel Eng" k f QW -?.

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t. cen.raf .

f.1 Scope .

~7 Ch tn These Rules for cataining general approval are to be applied fer c.*wrcking the suff*c:ent dt... -~ 6 of

, crar.xanatts for diesel engines for main prop 41sion and auailiary purpeees.

Diesel engines are to be so designed as to be capable of contsnuous operation at their rated power when running at rated speed. .

os

+

Engines for special applications which cannot satisfy these Ruies will tw suoject to special consideration if detailed cale';14tions or measurements are submitted.

O 1.2 Fie14 of application

• These Rules apply to engines wita solid-forged and semi-built crankaufts of steel or cast stest wita one b crank tnrow between two main tearings.

The Rules do not aeply to other types of crankanatts sucn na fully. built crankauf ts or crankaufts of nocular cast iron, nor to engines having two or more crarw misws between two main bearings, nor tnose wim cifset

. . P'P8*

1.3 Calculation princiales A.

• i The alme=.sionirg of crann. shafts is based on the assumption that the fillet transitions terween tr.e cra..k:in and we: as we!! as between the journal and wes are the areas with tne hignest stresses anc fer weica a calculation of tne stresses is to be carried out.

. The outlets of oil bores into crankple.s ane journals are to be formed in such a way tr.at the stresses at the oil tores are less taan t.a.coe In the fi! Jets.

( Calculation of crankar. aft strengta consists initially of determining the ruminal alte- .atieg bencleg anc

( rarniral alterr.ating torsional stresses wnica, multiplied by the appropriate stress concentration factars using the oeformation hypetasais (von Mises' Criterion), give a comparative alternatang stress. Th.: esmparative

alternating stress is then esmparet wim the fatigue strengta of the selected crankanatt snaterial. This

c=mperisen gives the solutica to the question of sufficient dirnensioning of a cranasnaft. .

,. It must be ensured that the maaimum stresses which may arise from unfavourable operating conditions within the service taege are determined.

,. i.. w..l., a.a

• 4 In orter to facilitate the calculation of crankanaf ts for the rated power at too rated speed spect!!ed by t*e engine manuf acturer, tne cocuments and cata listed in the following are to be submitted to tne Society and listed in ene appropriate form in additaon to sne docurments required for accrovalin ac:steance with tne

'; construction Rules:

. crackse.af t crawing

whicn must contain all data in resoett of the gesinstrical csnfiguration at tr.e crannstalt 8412140074 841001 PDR ADOCK 05000322 0

• PDR

-+

l. p, A cW.~ p b ktuG . L. J. M. i1.11 1

o .

IAC3 . WP!!. .:.

. type assignation and kind of engine (in line engine or V. type engine with adjacent ' connecting rocs. !srised connect'"5 rod or articulated.

type connecting rod!

. operating and combustion met.*ed (2. stroke or 4. stroke cycle / direct injection, precsmaustion c.~. amber, etc.)

- rumber of cylinders ,

a rated power (kW l .

. rated engine speed I1/ min I

. sense of rotation, see flg.1 .

. firing order with the respective ignitlen Intervals and, where necessary, V angle o pseeflg.l.

I O -

5 p 4\"" >% g%

• g 4,"

3 f

e  %

{

<l e,ving crivmg Sncf! flange emanter

' Sacft ficoge choter , j steciawis e I /ctackwise elecawise clotirwise Fig. I Delgmtian of true cylledes

. cylifwter clameter Imm) i' . maaimum cyunder pressere p,,, Ibar I

. carge air pressure (bar! ,

(before inlet valves or scavenge per'.s, wmcmever appliaal

. reminal compression rutie [ .1

. connecting rod length LH I**I

. escillating weignt of erw cr'ank gear (kg l ,

(in case of V. type engines, where necessary, also for trie cylineer wait with master ed articut.sted.

type connecting rod or forked and inner tsanecting red) ,

. for engines wita articulated. type connecting rod, we flg.1.

. distance ta link point L A I** I

= Ilek egle e,., I'l .

. connetting rod leagth L3 lmmt

• 69 0

1AC3 . T7!E

• 3 S.

/p l

• o

\ // N

\

\. .

/

(

I %

• y F1,2 3 Artionate&eype corriscting red N .

= gas-pressure curve wita values 11sted and presented at equidistant Intervals Therever possibles

- gas pressure curve with values listed at equidistant intervals l'CA = degrees of the rotational I angle of the cranasnaft I untervals equidistant and lategrally divisible by the V.engte, but not teos tr.an 2.J 'CA for 2 stroke nor J 'CA for betroke cyde)

Cr. Lt the gas pressure curve has not been enessured:

. Iridicatleri of the constant. pressure corkhstion Interval

• g eeressed in 'CA rneasured trarn t*.e T.D.C as well as of tne polytropic esponent ter espansion (wnere necessary, us to 3 esponents for different ranges a., a; and a 33and cernpression ranges, see flg. 3.

e ,.

II*I 83; l

• ~- s i I

ir g "' /

l l Ns t l

l l

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- I as

t. ,

1 I

Fig. 3 Detains ei comaustien swe

' 0' s. e, toca l leg v i en s

. for engmes with articulated. type connecting roe (also the follower g details for the cylineer w6tn articulated. type tennecting red)

. masimum cylitiser pressure p,,, (bari

. energe alt pressure I ter l .

(before Lalet valves er scaveege ports, whicaever aselies)

. cominal terr aression tothe (.l*

. gas pressure rarve

. -3 .

4

e- .

IAC3 . Tp!!. .s.

. estaats of cranksnalt mater;al *

+

. material cesigstion (ac:orcing to CIN. A!31. etc.)

. mecnanical properties el material (minianum values attained from longitudinal test specimens)

The minimum requiremerits of the Society's Itules for Materials enust have been complied with:

. tensile strengtn IN/rnm2g ,

2

. yield strengta (N/mm g

. reduction in area at breals I%1

. elongstien A3 I%1

)

. Impact energy . KV (31

<*' . metned et material tr:elting procesa (ooen . huerts furnace, electric farnace, etc.)

. type of farging (free term forgw. grain flaw farge, drop forged)

. heat treatment

. surf ace treatment (inductaen hardene, nitricee, enremi.ned, rolles, seet poenu, etc.)

. partiestars of tse alternating torslenal stresses, see item 2.2.

. 2. Cai.dation et noeninal rerunnes ,

2.1 cas aats. of aaemaung nroe e em t. n e., m.menes and snearing imco.

s 2.1.1 Ammmpties s The calculatlen la te he based on a statically cetermined system, se t.".at arily see sangte trans tarew is

• ., consicered of wnica the leurnals see supported la the centre of adjacent bearings ard weich is svale:: to gas and inertia forces. The kneing lengta la e as the legth between the two main twarings (datance t. 31 se,!!guresato6. .

l

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w 4

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i w

l l o

.e I a l i 1 I h;t

'-3,  ! I 1

l

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{ j, 1l ,

,l t,

- - t.

I Lt Lt .

f $

frig. 4 Cronis throw for in line eng'ww *Y"

~ ucs . sp*1 3 6 i. '

i . l' l

i !c-

. t i j I

w I

i

, br.2.. ,'. .

l 'E l l l

. . = .L .

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.{' ,e , ai .k

! L. l ' l' L. '

-L- ' N I r--L I

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n . > c ~ e- f ~. w - ~~ ~

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t.

... a l..

l

. p's .

I l l t i

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!. 7 2, 'q ...LA 2 r (l - a: @

y.c - -7 .

lj". .

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r::: !c *

.m:- ;  % )

Le l. -l L i r -,

• Lt Lt -

I L

j t- ,

Ms. 6 Crank inrew of disc.eype crannahafts N nominal beneing meenent is talien as tu heding mornent in tne crank wee cross section at the mics:e of the solid wee (distanes 1. g) wien a triangular bending moment lose sue to beneing moments and smearing forces reswiting from the radial esmponents of tee cannating red force.

N nominal alternatmg stresses due se bending mornents and sheating forces are to M referred to 13e cresa.sectsenal area of tr.e trank wet. TNs reference area el cross section results from the *,s thickness T and the wet widtn & la the centre of the everlap of the pins er. If appropriat's. at the etstre of the adjaceat generatrises of toe two pins 11 taer ce net everlap. see figure T.

l teeminal anese beneing stresses are neglected. ,,

[

! Ll4 CaAculatsen of nominaJ af temating barading rtreues l

N calculation is carried out in such a way. tr.at tne radial f orces PS acting usen tse cranh ;in ew ng ts o

l ,

L

o_ - . ,

4 1AC1. *P!f.

gas anc inert:a forces will be c.alculatec for 311 c*ank positions witMn one woruing cycle (smallest interval 2.3 *0A ter :. stroke anc 3'OA for to streme cyc:e). Prem tnese indivicual values A.P ' ** h'E *** P**"'

value P g , racial

( force presses cown woon ce ersek) and the hignest negative valueg P ,,(racia.1 ter :

putis at tne cranw)is taken and the nominal alternating beneing force Pgg ec:uring during one workirig cycle deterrninec by means of ecuation P

,gg aIf.(P,,,,.P,,;3) g g 4

By means e t tne nominat alternating f orce P5N and tne assumptiens mace in 2.1.l ce decssive neminat alternating bending rnoenent will con be calculated .

"BN *

• IMSmaz

• M A. mini O . arn:. from tne latter, ce nemir.al alter.atial bencing stress.

. MAN . IO3 ~

88N * *

• et

..g 2

• e

. M 6 In case of V.ty;e engb.es, the bending a: o .ents . progressively catalates from the gas and inertia terces .

of the two :ylincers acung on ene crana throw are sacerposed ac:orcing to paese, the differseg designs (1stved cannecting red. articulated-type esonecting red or adjacent connectrag rods) being taken ints account.

There cere are cranus of different geometrical coc.figaration (e.g4 asymmetric cranks! in one crannsnatt.

ce calcalation is to esver all crank variants.

. ~

The calculatasa of the nomir41 alternating shearing force and stress is as follows:

s 1

i ,

Cg *

• f * (Q,,, . Q minI

.CN e

QN** T

• P e 8. w . ,

wneref P gg ( N I norninal alternating bending forcs

. M gg i Nm I newl alternaung Wng momet g

IAC!- Ul* .?.

e e gg i N/mm i nominal alternating hendieg stress ,

"J (mm I I equatorial moment of resistance referred to cross-sectional area of wa:

Qg (N ! nominal alternating snearing force 2

e,N w IN/mm 1 nominal alternating stres:, due to shearing force F !mm 2 1 area referred to cross-se: tion of he .

12.3 Ndnien of a!ravating bending strumens in 1111ets The calculation of stresses la to be carried out for the crarspin !!!!st as well as for the journal fl!!st.

4 For the cankpin illlet

' BH

• 8 (*5 * ' BN

/ .. ,

wneret

'cSH IN/mm I al *fn'tiet 3*nd*g stresa in e-ankpin fillet og (. I stress c ncentration factor for hendirig in crankpin fi!!st (cetermination . see item 3)

For the jour .a! fule't:

. '1C * * ( IS * ' EN

• IQ*'QN) where: ,

2 g Sw. ( N./mm 3 ,3;,,n,ging , tresses in journal !i!!et

$ l. I stress c:ncentration f acter for bending in journal fll!st (cetermination - see item 3)

I l. I stress c:ncentration fac :t for snearing (cetermination see item 3)

S q .

2.2 Calculation of alternating torsional strusses 4

2.2.1 Canaral The calculation of the nominal alternating torsional stresses la to be performed by tne engine manufacturer. .

The approval of an engine is to be based on a value determined by the engine manufacturer. Cnly in tse ansence of sucn a value will it be necessary for the Society to include in the calculation a fised value or a value found by forces vibration calculation.

2M Calculation of nomiral alternating torsional stresses .

The alternating tarques are to be ascertained for every mass point el the system and !sr the entire scete range by means of a P.stmonic syntnesis of tne forced v'brations from the zero orcer up to at least to tne 12:n orcer. *niist coicg so. allowance must be made for tne campiegs that exist in tee system. The scese i stages snall ne selected in suen a way tnat tne transient resconse esa te recorced wita sufficient accuracy, i

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l - ' i-i g / g

IAC3 . Tp'E -  !.

Tne nominal alternating torsional stress in every mass peint, wnica is essential to the assessment, resu ts from the fc!!owing ecuations MT

. 3 1

3 e-7 . LC P

M *

• T Tmas

• MTmin)

D D

., . 3.(D* y *) .,. 3.(D" y ") .

. w~, . s.

t g (N/mm 2I nominal attemating torsional stress referred to erankpin or journal M ( Nm I nominal altamating torg.=

7 w (mm3i polar moment of resistance referree to cNss-sectional area of bored cranwpin or berec p

journal M7 ,,,, MTmin extreme values of the torque with c:nsicerat!=n of the mean tercue

. To assess the cranksnatt, t .at torsional stress is to be used that, in conjunction with the associated bencing stress, results in the highest comparative alternating stress as per item J. The s barred speed ranges are necessary, the torsional stresses within :nese ranges are ta be neg!ec.ec in the calculat:en cf tne c mparatsve alternating stress.

Barrec speec ranges are to be so arranged that satisfactory operation la possible ces:sta tneir existercs.

There are to be no barred s:eed ranges above a speed rat:s of 12 0,3 of the ratee soeed.

The approval of crankanafts is to be based on the i,nstallation wnica gives the nignest camcarative st e'ngtn accarcing to item J anc for N lowest safety factor accercing item 3.

j Thus for esca installation wita a rig!cly coupled engine, it it to be ensured by suitasle catculati:n tnat tne

1. approved nominal altemating torsional stress is not exceeced. This calcalatien is to be summitted for i, assessm ent.

In the case of installation with elastically coupled engines, it will suffice to calculate tne nomic.a!

alterr.ating tersional stress of the' system up to the primary part of tre coupling only, proviced tne c=ucting sufficiently separates tre engine from the machine y it is criving.

2.2.3 Calc 41ation of altamating torsianal stresses in ill ets The calculation of stresses is to be carried cut fcr the cranupin !Ulst as we!! as Ice the journal (H!st.

For too cran = pin tillet tg a 2 (o7 TN) .

wneres Tg l N/ men ! alternatial torsional stress in crannoin fi!!et a; (. I stress c:ncentration factor ter ternion in cranwpin fl!!st (ceterminaton . see item 3) g-For the journal fillett i

e

---

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

r-

. [AC3 . Wo/* 9 wheret .

t. I N!mm2 I alternatin$ torstonal s.rets in ,ournal fl!!st w

I . I stress concentration factor for teruon in journalilliet (octermmation - see item J) .

g7

3. Caladation of stress concenration faciers 11 Stress cumucentration factors for crank throws witnaut recessed fulets 3.1.1 Geimal The calculation of the stress cancentration factors is based on investigations by Forsenungsvereinigung Verbrennungskraftmascninen (FVV) and wnica apply to solid forge 4 crannsnatts and to the crankoin 1111ets of semi-built crankanatts.

A11 c ank dimensions necessary for the calculation of stress concentration factors' are shown in figure 7.

J g e 8 f

, \t,I,.i--1,--

m.

L-- i / (,W%

t

- w ;l 4 -l *, _j@- w  !,a c I

. I v

l

/* . . .dI g l *l

• l

\ f vs

\ *!

l1 p me Ij n"/ lw / i A . \, E.'

g - i

- ~ I ch', 7 - l 1 e t. 6 i

,I W

A.  ! i l ti c t \ .

/ 6 I

I g /

-  ! 1

-l g ,/

h@ 4

• f N f.s b NE .

Fig. 7 Crank dimeulons necessary for the calc.dation of stress concentration factors

'/ Actual cimensions:

O  ! mm I crankpin d:ameter

l O gg I mm 1 dameter of we in erankMn Rg I mm I tillet radius of crankoin T

H ( mm I recess of crankom Og ( mm ] journal diarneter 0 3g ( mm 1 diameter of more in jcurnal Rg I mm I fillet radius of journal T I *

• I ' 'II'"'"*I C

E I mm I pin eccentricity 3 Immi pm everlao .

O.O g 3' g

• I of.

• t mm I was inickness a ( m m I wes wista .

w

!ACS vPl* .

The followi"5 relates cimensicas will be acplied for the calculation of stress c=ncentration facters in crank:in fillets l journal fillets ra Rg/D lr=R C s' 4 5/D w a w/D ,

b = B/D d

c = DSC/O

- dg a D3g/D t

g a TMg t

c = Tmc They are valid !=r tne ranges of related dimea.sions fer whicn tne investiga:icns have been carried out. They are as icilows:

C.J 5 s s C,7 C.2 sw $ C,5 1.2 s b s 2,2 C,33 5 r 5 C,13 C 5 dc 5 C,3 C s,dH 5 C,3 .

Unissa alterna:ive values are furnisnec by rellatie measurements, the stress c:ncentration fac srs Pave :: .

,? be calculated by means of the !cijowmg formulae applicable to wes-type cranksnafts only. Stress concentration factors for disc. type cranksnafts ?.sve in any case to be established and determined by tests.

(* The stress c:ncent*2 tion factor !=r bencing is defined as the ratio of the reference stress c'y - oc: .: ring in the fil:ets uncer bencing l cad acting in tu central cross-section of a cranx - to tne nominal stress referree to tne wen cross-sec: ten.

The reference stress c'y has to be determined from the principal stresses og and c 2 by means of me equation:

c., . qc,2 c ,2 -c,c, .

The nomir.at stress has to be determined for web-ty;e cranksnatts, under the bendin5 moment in the micele of the solid wen. For disc. type crankshafts, tne nominal stress has to be estantisned under tne bencial moment occurr g at the distance :.. from tne disc c=ntre line, see fig. 6.

The stress c=ncentration fact:r for :crsien is defined as the ratio of the maximum torsional stress oc:grring unce* torsional ! cad in tse fillets to the nominal stress ref erred to me bored cranwpin er journal cr ss.

sect:en. The maximum :=rsicnal stre s has to be determined from

• *v -/C -

vT .

O

-e

l.A CS - W P 'I .

3.1 2 5tr==z c . . tion fac:ar f ar bending in crangin fu:et .

The stres.: c ncer.ttst.on factor is calculatec in ac::rgance wi:a tse fo!!awieg !=rmula:

a3 = *,6714

• i (1, wl

• i (w)

• f (b)

• f (r)

• i (eg )

• i (eg) where:

! (s, w) = - 6,1333 27,2004

• w - 77,Jf 23

• w2 , 9 g,9,3g . ,3 - 4C,0416

• w" . (1-s) * (?,J600 - 38,3480

• w -

137,3413

• w 2 - !?2,J346

• w3 . 83,2716

• w") . (1-s)2 . (- 3,33?? . 23.C44

• w - 70 JJ71

• w2, 17,0323*w3- 37,1132

• w")

f (w) = 2,1770

• w0 7171 f (b) = 0,6340 - 0,0077

• b . C,1473

• b 2 f (r) = 0,2:31

• r(- 0,3231) 3 f (d )g= 0,7??) . 0,27

• dC*I'CIII'd G . C.J306

• c C 2 3 i (d )g= 0,??73 . C.3143

• dH - 1,32%l d H . 2,4147 c g 3.1.3 Stress concentration factor for bending in journal 1111e -

The stress cenes-tration fact:rs are cale21ated in ac orcance with tne f=11owing formulae:

55

• 2*II"' I SI ** "I I S I*I ' IS IDI ~SI I#I ' IS Id CI 'IS Id MI wnere:

! (s, w) = - 1.7623 - 2.?!::

• w - 1,3276 =2. (1-sMJ,1167 - 3,3:2?

• w . 3,1371

• w2 ) , (1-s)I t- 2,1367 3 *

'- 2,32?7

• w - 1,2?J2

• v2) n f (w) = 2,2422

• wC,7348 3

f 5 (b) = 0,J616 . A!!?7

• b . C,1176

• b f 3 (t) = C,1?C8

• r(- C,3363) 2 f3 (dg) 1,0012 - 0,64a1

• de . I',2263 4g

, fg (dy) 1,C312 - C,1%3

• dy

• 0,;C73

• eg I

Sg = 3,0123

• Ig (s)

• fg (w)

• fg (b)

• 19 (r)

• fg (eg) where: ,

fg (s) = 0,6363 2.1630-(1-s) - 1,3212-(1-s)

I (*I' ; aw 5,n=+ ' w Q

-/ / ' .

• W

IACI . TPl! 12 1g (b)a.0.3 3 f, (r) = 0 J331

• r I' 0*2 333 s

!q(d g ) = 0,??37 1.11a?

• dg . L,7373

• dg 3.1.6 Stre= concentration factor for torsiEn in c-ankpin fillet The stress concentration factor is calculated in ac::rdance witn :ne,f allowing formula:

c,. 0,123

• I (r, s)

• f (b) a wnere:

g g,, 3) , ,(. 0,3:: . 0,101J * (1-s))

5'  ! (b) a 7,3?33 - 10,53h

• h . J.J68:

• b2. 0,337

• b3 3.1J 5 tress concentration factor for tarsion in journal fWet

!! the d!amete-s and fulet radii of crankpin and journal are ce same, can the stress c:ncentratica f act: r for torsion in journal!!11et is the same as in emnk=in fWet ,

8 a 7 7

' -  !! crann:in anc jour al diameters and/or radu are of different sizes, then t.*.e stress concentration fact:r :s calcalatec witn tne f:ll=wint :rmu.la:f S s. 0,323 * ! (r, s) * ! (b)

~

a f

where !(r, s) and !(b) are to be determined in accordance with item 3.1.4, however, the rsdius 31 the journal fillet is to be referred is the journal diametert RC N .

3.2 Stress concentration fac. ors for crank throws with recessed illlets The stress concentration f acters a=plicable to crarw throws with recessed fillets are cotained by mult: lyi"5, tne stress concentratien factors for tendin 5 ac:ording to item 3.1.2 and J.L.3 by a recess facter calculates by tne following formula: ,

-i = 1. (tg.tC I ~ II*3 ~ 3*2 ' 'I

• u-

iACS 't P/1 .

where: .

! i-1 fact:r !ct the influence of recess for other paramete-s sae item 3.1.1.

The formula is vslid if .

t g 5 R g/D tg 5 R CIO and can be acclied within the range

- C,3 $ s s 0,J All stress concentration factors acc:rting to item 3.1.2 and J.1.3 are to be multiplied by tne recess facter even if only one ill et is recessed.

t 4 Additional heriding stresses In addition to the alternating bending stresses in fillets (see item 2.i.3! further bencing stresses due to misalignment and becplate de!crmat:=n are to be considered and adcec as adciticnal bencing stresses as given in tne following Table:

Type of engine 8 add (N/mm 2 g Misalignment See,. late cefermati:n

2. stroke I 20 I 10 a-strone 2 20 0 l

where i

j e add mm ac ticnal stresses due td mbaugnment and/or beeplate de6mation

/ Furtne- additional stresses are likely to occur in the fillet as a result of bendin5 vibrations and axia:

. vibrations.

Sending vibrations ret;uire attention especially in tne case of engine plants where the ratio of speec to natural bendi"5 frequency of the "flywheellend crana system"is relatively high.

There asial vibrations are concerned, those due to two types of excitation ret;uire attention:

i The dominant excitation is due to the radial comoonents of the connecting rod ferces, which spread the t

l-crank throws and, wh.lst doing so, cause sxial variations in len5th and Dending stresses. Harmonic components of these forces, whien excite an axial natural frequency of the system, result in addit 2onal bending stresses, which are not inctuced in the alternating bending stress calculated in accordance with item 2.1.

1 I Azial vibration arnpiitudes are also likey to cccur as a result of torsienal vibrations wnere twisting of the individual crank throws resultsintengu variations, wnich add up to amplitudes at the free end which pulsate at twice the fret;uency of the torsienal vibrations.

Arial vibrations of tne first type can cause consiceraale adcitional forces in the cranksnaf ts of large two-stroke e"Si nes. Contrary to torsional vibrations, there Ls at present no generally accepted method of calculation in use. However, this coes not exonerate the engine rnanufacturer from the responsibility ' to""/

make approcciate calculations. ,

i

IAC3 WP!'. - la - -

3. Calculation of comparative altemating stress 3.1 Germeral The c:mparative alternatirg stress is to be ca culatec for the crankpan fillet as well as for t.Se journal fi!!et.

For this calculation tne determatien hypotnesis (von Mises* Criterien) is to be used.

In : Mis it is assumed that the maximum alternatin,g bending stresses and maximum alternating torstenal stresses within a cranksnaft oc=ur simultaneously and at the same point.

3.2 Comparative altemating struss The comparative alternat:ng stress is cales;ated in ace =rdance with the formulae given.

. For the crankoin f1IIet:

c, e le.g - cadd}

• 3 I H

i Fer :Me journa! !!11e::

e, =  : Y te gc .e e,1 2 ,3. ,2 c where: ,

e, IN/mm2l comparative alterna::ng stress for otner pararne ers see items 2.1.J. 2.2.3 and a.

For:Me remaincer of :Me calculation fsee item ?), the targe- of :Me two values is to be used.

6. Cajcalation of fatigue stren5TL g The fatigue streng:n is to be understood as that value of alternating bending stress vnica a cran'snaf:

u can

.) permanently vitas:and at :Me most highly stressed points of the !IIIe:s.

The allowabie fatigue streng:n fer a crankshaft can be calculated by the fol!owi"5f ormular c o, . = xco.a2c,.3,.e;o,m-i.mo-a2 "';"'

V[

where:

l c

0 %" IN#*

• I "II'***I' I**8E"' **#'"II" "I C#****h*it K (- I factor f r different types of forges and cast crankshafts !ce wnich no surface treatmint is done .

1,03 for grain flow forged or crop-f=rged cranksnaf ts .

s 1,3 for free form forged cranksnaf ts

= o,93 for cast steel cranksnafts 9

c (N/ men *l miMmum tensue streng:n of cracushaf t maternal ..

3 for other paramet rs see item 3.1.1.

4+-

,a =gy .

l

." !AC3 WP/E j Where no resulu of the fat:gue tests c=ncuct c on full ss== crank tarows or crankanafts wnica have teen suciectec to surf ace trestr ent are availatie, tne K-fact =rs for cannsnafts witnout surf ace treatment are to be used.

In each case the exce-imental values of fatigue strength car see out wita full si:e cranz snro-s er crankshafts are subjec to soecial consideration of eacn Society.

7. Calculation of shrink-fita of semi-built crank = hafts 7.1 Canural All crank dimensicns necessary !cr the calculation of the shrink-fit are shown in figure 1.

. I g g *'TN

/ -/ l \-

-- c

} h /

p% ,

Y

/ ., 4 6 .

si I 1

i i L I e -L . 3 -

C-I I

! @ l f b t I _ t I i I i ts ca

. i Fig.1 Crank inrow of semi-built crankshaft where:

N O Imm ! snrina diameter

-) 5

. L Imm ] length of snrink-fit 3

Dg Imm I ouuice diameter of web l

l or twice the minimum distance x between centre-line of journals and outer c=nt=ur of wet, whichever is less

! for other parameter see item 3.1.1.

For tne radius of sne transition from the journal to the snrink diameter, tne following c=ncit: ens must te maintainec:

Rc: 20. ! 3 O c and R c 2 0.3 (D5-O) c I

, calci:atec in ac::reance The actual oversi:e : of the snrina-lit must be witnin the limits I,;, ara :

wita items 7.2 and 7.J.

-/r-

~ IAC5 . TP/E 16 -

7.2 Necesary minimum oversize of shrink-fit The necessary minimum everst:e is determined by tne greater value calculates in ac::rcance wita itees 7.2.I and 7.2.2.

7.2.1 The calculation of the minimum oversi: is to be carried out for tne crank throw wien the absciute maximum torque M,,,, he torque .M,*,, correspones to me maximum value of me torque .Mimax calculated as per item 2.2.2 for the various mass poihts of tne crankshaft. .

, a

• 10 3

R

• max I

• S~ A S'S min x .a* q05 ' '5 (1-Q 2 Agg ,q 53 2

wita a ,Q e 4s C.23 for 2 0,40 QA 3 5

A 5 wnere Ig ( mm! minimum oversize

5. ( - I safety facter against s!!ppin5, however a value < tot less taan 2 is to be taken n

QQ3 ( - 1 ratio of different clameters u ( -  ! c: efficient !=r static friction E, (N/mm I Young's mocu!us 7.2.2 In addit:ca to item 7.2.! tne minunum overstze is also to be calculate acc:rcing to tne !:1:=w;ng fermula:

c*O 5 5 t 2

. ~ min

• E.A wnere:

c (N/mm ] minimum y eld strengtn i mate tal r crank web or journal whatever is less.

5 7J Masimum permissible oversi:e of snrir*-fit The maaimum permissible oversize is calculated in accordance with tne following formula.

c *0 3 0,5

• D 5 5 2 5 mas E.,

w where:

(mmi maximum oversi:e This c:nca: en serves to restrict tne sar:nkag-incuced mean stress in tne fillet.

-/b -

I g i , , .,

BEC85 GOO 54GB Blae - Engine and Compressor Division

.. . Del 8WSl sso esm u.

P.O. Box 2161 Oakland. Califomie 94621 Date: kkncd d. /98 4l To: G. 6. %us s<< t-From: [ //yuty Subjectr

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