Bsi bs au 226 1988 (2000) iso 7648 1987

BRITISH STANDARD AUTOMOBILE SERIES BS AU 226 1988 ISO 7648 1987 Specification for Nominal dimensions and tolerances of flywheel housings for reciprocating internal combustion engines [ISO title Flywhe[.]

ISO 7648:1987

[ISO title: Flywhe l housing s for re iprocating internal

c m bustion eng ines— Nom inal dim ensions and toleranc s]

U C6 9.1 3.3 5:[ 62 – 2 3 – 5 2( 08 3)]

This Bri shStan ard, ha ing

b en pre ared u der the

directonof the Automo ile

Stan ards Commi e ,was

published u der the authoriy

ofBo rd of BSI an

comesinto fect on

3 Aug ust1 8

© BSI0 -2 0

The folowing BSI references

relate to the work on this

stan ard:

Commi e reference AUE/13

Draft for comment8 /79 7 DC

ISBN 0 5 0 1 7 7 5

The prep ration of this BritishStand rd was entrusted b the Automobi e

Stand rd s Commit e ( AUE/ -) to Tech ical Commit e AUE/13, upon which

the folowing bodies were represented:

Dep rtment of Transport ( Hig hway s)

Freig ht Transport Association

Institute of Roa Transport Eng ine r ( Incorporated)

Lond on Reg ional Transport

Ministry of Defence

National Bus Comp ny

Roa Haulag e Association Ltd

Society of Motor Man facturer and Tra er Limited

Am endm ents is ued sinc publ cation

Amd No Date of is ue Comments

Pag e

4 Relationship of pi ot bearing

Annex Procedure for measuring

Ta le 1 — Fly whe l housing

Ta le 2 — Ta ped holes and bolt or

National foreword

This BritishStand ard has be n prep red u der the direction of the Automobie

Stand rd s Commit e an is identical with ISO7 4 :19 7 “ Flywhe l housings fr

r ecipr oca ting inter na l combuston engine — Nomina l d imensions a nd

toler a nc s”, publshed b the International Org anization for Stand ard ization

( ISO)

Term inolog y and conventions The text of the International Stand rd has

be n a prov ed as suita le for publcation as a BritishStand rd without

d ev iation Some terminolog y and certain conv entions are not identical with those

used in BritishStand rds; at ention is d rawn especialy to the fol owing

The comma has be n used as a decimal marker In BritishStand ards it is cur ent

practice to use a ful point on the b selne as the decimal marker

W herev er the words “ International Stand rd” a pear,refer ing to this stand rd ,

they should be rea as “BritishStand ard ”

The Tech ical Commit e has rev iewed the prov isions of ISO1 01 and ISO7 4 ,

to which reference is ma e in the text, and has decid ed that they are ac epta le

for use in conju ction with this stand rd A related BritishStand ard to ISO1 01

is BS3 8 “ Engine r ing d r a wing pr a ct c ” Part3 “Geometr ica l toler a ncing”

A British Stand ard d oes not purport to includ e al the neces ary prov isions of a

contract User of British Stand rd s are responsible for their cor ect a plcation

Com pl anc with a British Standard does not ofitself confer im m unity

f om leg al o l g ations

Cros - referenc s

Inte national Stand rd Cor esp nding BritishStand rd

ISO27 :19 9 BS418 :19 4 Spe ifica tion f r clea r a nc hole f r

metr ic bols a nd s r ews

( Identical

Sum mary of pag es

This document comprises a f ont cov er, an insid e font cov er, p g esi andi ,

p g es1 to8, an inside b ck cov er and a b ck cov er

This stand rd has be n up ated ( se copy rig ht d ate) an ma hav e ha

amendments incorporated This wi l be indicated in the amendment ta le on the

inside f ont cov er

1 Scope and field ofappl cation

This International Stand ard specifies the nominal d imensions and tolerances of fly whe l housing s for

reciprocating internal combustion eng ines, in p rticular those which afect inter-chang ea i ty with mating

p rts

It a ples to reciprocating internal combustion eng ines except eng ines for air raft and p s eng er car

Fly whe l housing s of siz codes1 to4 are recommended for commer ial v ehicles an buses

2 Ref r nces

ISO27 , Fa stener s— Clea r a nc hole f r bols a nd s r ews

ISO1 01, Te h ica l d r a wings— Geometr ica l toler a ncing— Toler a ncing o f r m, or ienta tion, loca tion a nd

r un-out— Gener a liie , d efini ions, symbols, ind ica tions on d r a wings

ISO7 4 , Commer cia l vehicle — Clutch housings fr inter na l combuston engine — Nomina l d imensions

a nd toler a nc s

)

3 Nominal dimensions a nd tolerances

3.1 Flywhe l housing

Se Figure 1 and Ta le 1

Table 1 — Flywhe l housing dimensions and toleranc s

1)

At present at the stag e of draft

Dimensions in milimetres

Siz co e

A

Ru -out

a

0

01

0

0

1/2

1

2

3

4

5

6

1 24

1 010,0

7 7,4

6 7,7

5 4,20

51 ,18

4 7,6

4 9,5

3 1,9

314,32

26 ,7

+0,25

0

+0,25

0

+0,25

0

+0,25

0

+0,20

0

+0,13

0

+0,13

0

+0,13

0

+0,13

0

+0,13

0

+0,13

0

not a plca le

0,4

0,3

0,3

0,31

0,27

0,25

0,25

0,25

0,25

1 4 0

1 16

8 3

71

6 8

5 3

4 9

4 1

4 4

3 6

3 8

10

10

8

8

8

8

8

8

8

8

8

NOT Ru -out tolerances t shal b me sured on the as embled eng ine mou ted on is sup orts in acordance wih the an e

( Se ISO1 0 for defini on of ru -out.)

a

Dimension D relates to flywhe l housing s wihout rub er se ling Howe er, this dimension ma b ince sed if a rub er se l is

neces ary











3.2 Bolt or screw spacing and size

3.2.1 Dimensions and toleranc s

Se Fig ure 1 an Ta le 2

Ta le 2 — Ta ped holes and b lt or screw spacing and dim ensions

Fig ure 1 — Flywhe l housing

eng g em ent

C

nom

mm

( se Fig ure 1 an Fig ure 2)

0

01

0

0

1/2

1

2

3

4

5

6

24

24

16

16

1

1

1

1

1

8

8

M16

M16

M1

M1

M1

M10 a

M10

M10

M10

M10

M10

1 3 0,0

1 10 ,0

8 0,9

6 9,4

619,1

5 0,1

4 6,72

428,62

3 1,0

3 3,3

28 ,7

NOT 2 ta p d holes are o tonal for aluminium flywhe l housing s of size code1

a

M1 ma b used for hig h eng ine torque a plicatons

3.2.2 Spacing

Ta ped holes shal be sp ced equaly on each side of the v ertical an horiz ntal a is lnes as shown in

Fig ure 2

4 Relationship ofpi ot bearing bor to flywheel housing

The depth of the piot bearing bore ( se E in Fig ure 3) extends f om the fly whe l housing face to a shoulder

in the fly whe l, to a should er within the c ankshaft or to the c an shaft flang e face

Ta le 3 — Depth of pi ot bearing bore Fig ure 2 — Bolt or screw hole spacing

Dimensions in milimetres

Siz co e

E

nom

E nom o tional for:

d uble plate clutches when

extra-hea y flywhe l is used

o e c ntr clutch

0

01

0

0

1/2

1

2

3

4

5

6

26

26

10

10

10

10 –1 2

a

10 –1 2

a

10

10

71

71

—

—

13 ,4

13 ,4

13 ,4

13 ,4

—

—

—

—

—

—

—

—

—

—

—

—

—

71

10

—

a

An E dimension of1 2mm is o tonal for flywhe l housing size codes1 an 2 when the clutch shaft b aring is located in the pilot

b aring b re of the flywhe l or can shaft en , i.e.when the b aring is not located in a se arate car ier

5 Mating pa rt fla ng e ( for ex mple, clutch housing s)

The dimensions an tolerances of clutch housing s for reciprocating internal combustion eng ines are g iv en

in ISO7 4

Limits and fits of the pi ot d iameter of the mating p rt are at the dis retion of the man facturer of that

component The manufacturer shal also specify the tolerances of form an position of the mating p rt

flang e

The clearance holes of the mating p rt flang e shal hav e the same location as specified u d er3.2.2 and

shal be in ac ord ance with ISO27

Fig ure 3 — Depth of pi ot bearing bore

Annex Procedure for mea suring bor eccentricity and fa ce deviation

( This an ex forms an integ ral p rt of the Stand rd.)

A.1 Sco e

This an ex prov ides a u iform procedure for measuring bore ec entricity an face dev iation ( ru -out) of

fly whe l housing s after as embly to an eng ine Limits of bore ec entricity and face dev iation are g iv en in

Ta le 1

A.2 Measuring proc dures

A.2.1 G eneral

A.2.1.1 A dial ind icator with rig id ex tension b r is required

A.2.1.2 S races which are to be measured shal be fe f om dirt and bur s

A.2.1.3 Prep re a chart as shown in Ta le 4 to help in determining bore ec entricity

A.2.2 Ec ent ricity o housing

A.2.2.1 Mou t the ind icator b se on the fly whe l or c an shaft flang e as close as pos ible to the housing

pi ot bore to minimiz deflection

A.2.2.2 Ad just the ind icator point to be perpendicular to the housing pi ot bore and set at z ro in

the6o½clock ( mand tory ) position ( lower v ertical

A.2.2.3 Slowly rotate the c an shaft an record the indicator rea ing along with the a propriate positiv e

or neg ativ e sig n at the9o½clock( a), 1 o½clock( b), and3o½clock( c) locations Confirm that the6o½clock

read ing is sti z ro Record the rea ing s on l ne A in Ta le 4, being sure to include the positiv e or neg ativ e

sig n

Ta le 4 — Data chart

CAUTION — Sig n desig nation relativ e to d irection of indicator tip mov ement is not the same for al

indicator For al measurements in the calculations car ied out in ac ord ance withA.2.2, outward

mov ement of the ind icator tip with respect to the centre of the bore being measured is to be considered a

neg ativ e rea ing

A

B

C

D

E

F

Observ ed indicator rea ing

Adjustment for bearing clearance

Half-bearing clearance ad justment

Total cor ected v ertical indicator rea ing

Cor ected horiz ntal indicator rea ing

Total horiz ntal ind icator rea ing

0

—

—

I

v

=

—

I

=

a=

—

d /2=

E

1

=

b=

d=

—

—

c=

—

d /2=

E

2

I

V

=b+d

E

1

=a+d/ 2

E

2

=c+d/2

I =E

1

–E

2

v

( )

2

I

H

( )

2

+

=

A.2.2.4 Position the indicator at the1 o½clock location and d etermine d , the a justment for clearance in

the main bearing a jacent to the fly whe l, b an a propriate method,for ex ample b raising the c ankshaft

to its up er l mit.Record the a justment for bearing clearance on l ne B in Ta le 4 in the1 o½clock column

This v alue shal alway s be positiv e

NOT A flo r-mou ted sup ort wih a p d ed pry ar or other suia le me ns can b used to raise the fly whe l; howe er i should

not b fored b y on the p int where the b aring cle rance has b en remo ed, nor should the housing b used as a fulc um

A.2.2.5 Cor ect the1 o½clock rea ing obtained inA.2.2.3 b alg ebraical y ad ding the a justment for

bearing clearance to it

This is the cor ected total v ertical indicator rea ing (I ) Record this v alue on lne D in Ta le 4

A.2.2.6 Cor ect the3o½clock and9o½clock rea ing s fomA.2.2.3 b alg ebraicaly a ding an amou t eq ual

to one-half of the a justment for bearing clearance deter mined inA.2.2.4 to each of them This can be done

b taking the clearance ad justment d etermined inA.2.2.4, div id ing it b two, an entering it on l ne C in

the3o½clock and9o½clock columns Ag ain, this v alue wi alway s be positiv e The read ing s, cor ected for

bearing clearance, can then be obtained b alg ebraicaly summing the v alues in lnes A an C of

the3o½clock and9o½clock columns These v alues shal be denoted as E

1 and E

2

an entered on l ne E in

Ta le 4

A.2.2.7 Determine the horiz ntal ind icator read ing ( I

H ) b taking the alg ebraic diference betwe n the

cor ected3o½clock and9o½clock rea ing s ( I

H

=E

1 –E

2 ) This v alue is to be entered on l ne F in Ta le 4 Fig ure 4 — Resultant total indicator reading , I

A.2.2.8 Determine the resultant total indicator rea ing (I ) of the housing or ad apter b locating the

inter ection point of the total v ertical indicator rea ing ( I

V ) and the total horiz ntal indicator rea ing ( I

H )

in Fig ure 4, or calculate as fol ows:

I =Æ( I

v

)

2

+( I

H ) 2

NOT This v lue ( I

R ) is consistent wih a total in icator ty e re ding s are the limis sp cified in Ta le 1.I is not ecentriciy as

such Actual ec entriciy is e ual to one-half of this v lue

A.2.3 Fac deviat on o housing

A.2.3.1 Mou t the indicator b se in ac ord ance withA.2.2.1

A.2.3.2 Ad just the indicator point to be perpendicular to the face

A.2.3.3 After elminating the c an shaft end play , e.g , b titing the c an shaft or b incl ning the eng ine

a proximately15° to20°, set the dial indicator to z ro in the6o½clock ( not mand tory ) position

A.2.3.4 Taking care to ke p the en pla el minated in the same d irection as in the6o½clock position, rotate

the c an shaft one complete rev olution to d etermine the total indicator rea ing

A.2.3.5 Comp re the total indicator rea ing with the lmit specified in Ta le 1

Publica tions referred to

Se national foreword

226:1988

BSI

3 9 Chiswick Hig h Roa

London

W 4 4AL

BSI is the independent national bod y responsible for prep ring

BritishStand ard s It presents the UK v iew on stand ard s in Europe an at the

international lev el It is incorporated b Roy al Charter

Revisions

BritishStand ards are up ated b amendment or rev ision User of

BritishStand ard s should make sure that they pos es the latest amendments or

editions

It is the constant aim of BSI to improv e the qual ty of our products and serv ices

W e would be g rateful if any one find ing an inac uracy or ambig uity whi e using

this BritishStand rd would inform the Sec etary of the technical commit e

responsible, the identity of which can be fou d on the inside f ont cov er

Tel:0208 9 9 0 Fa :0208 9 7 0

BSI ofer member an indiv id ual up ating serv ice caled PLUS which ensures

that subs riber automaticaly receiv e the latest editions of stand rds

Buying standards

Order for al BSI, international an foreig n stand ard s publcations should be

a d res ed to Customer Serv ices Tel:0208 9 9 01 Fa :0208 9 7 01

In response to ord er for international stand rd s, it is BSI pol cy to sup ly the

BSI implementation of those that hav e be n publ shed as BritishStand rds,

unles otherwise requested

Inform ation on standards

BSI prov id es a wide rang e of information on national, European and

international stand rds throug h its Library and its Tech ical Help to Ex orter

Serv ice Various BSI electronic information serv ices are also av aia le which g iv e

d etais on al its prod ucts an serv ices Contact the Information Centre

Tel:0208 9 71 1 Fa :0208 9 7 4

Subs ribing member of BSI are kept up to d te with stand rd s dev elopments

and receiv e substantial d is ou ts on the pur hase price of stand rds For d etai s

of these and other benefits contact Member hip Ad ministration

Tel:0208 9 7 02 Fa :0208 9 7 01

Co yrig ht

Copy rig ht subsists in al BSI publcations BSI also holds the copy rig ht, in the

UK, of the publcations of the international stand ardization bod ies Except as

permit ed u der the Cop rig ht, Desig ns and Patents Act 19 8 no extract ma be

reproduced , stored in a retriev al sy stem or transmit ed in any form or b any

means – electronic, photocopy ing , recording or otherwise – without prior writ en

permis ion fom BSI

This do s not preclude the fe use, in the cour e of implementing the stand ard,

of neces ary detai s such as sy mbols, and siz , ty pe or g ra e d esig nations I these

d etais are to be used for any other purpose than implementation then the prior

writ en permis ion of BSI must be obtained

I permis ion is g ranted, the terms ma includ e roy alty p y ments or a lcensing

ag re ment Detais and a v ice can be obtained f om the Copy rig ht Manag er

Tel:0208 9 7 7