BS-AU-226-1988 ISO-7648-1987.pdf

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: Flywheel housings for reciprocating internal combustion engines Nominal dimensions and tolerances UDC 629.113.3/.5:62 213 562 (083.3) Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:05:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS AU 226:1988 This British Standard, having been prepared under the direction of the Automobile Standards Committee, was published under the authority of Board of BSI and comes into effect on 31 August 1988 © BSI 02-2000 The following BSI references relate to the work on this standard: Committee reference AUE/13 Draft for comment 82/79772 DC ISBN 0 580 16727 5 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Automobile Standards Committee (AUE/-) to Technical Committee AUE/13, upon which the following bodies were represented: Department of Transport (Highways) Freight Transport Association Institute of Road Transport Engineers (Incorporated) London Regional Transport Ministry of Defence National Bus Company Road Haulage Association Ltd. Society of Motor Manufacturers and Traders Limited Amendments issued since publication Amd. No.Date of issueComments Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:05:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS AU 226:1988 © BSI 02-2000i Contents Page Committees responsibleInside front cover National forewordii 1Scope and field of application1 2References1 3Nominal dimensions and tolerances1 4Relationship of pilot bearing bore to flywheel housing3 5Mating part flange4 Annex Procedure for measuring bore eccentricity and face deviation5 Figure 1 Flywheel housing2 Figure 2 Bolt or screw hole spacing3 Figure 3 Depth of pilot bearing bore4 Figure 4 Resultant total indicator reading, IR6 Table 1 Flywheel housing dimensions and tolerances1 Table 2 Tapped holes and bolt or screw spacing and dimensions2 Table 3 Depth of pilot bearing bore3 Table 4 Data chart5 Publications referred toInside back cover Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:05:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS AU 226:1988 ii © BSI 02-2000 National foreword This British Standard has been prepared under the direction of the Automobile Standards Committee and is identical with ISO 7648:1987 “Flywheel housings for reciprocating internal combustion engines Nominal dimensions and tolerances”, published by the International Organization for Standardization (ISO). Terminology and conventions. The text of the International Standard has been approved as suitable for publication as a British Standard without deviation. Some terminology and certain conventions are not identical with those used in British Standards; attention is drawn especially to the following. The comma has been used as a decimal marker. In British Standards it is current practice to use a full point on the baseline as the decimal marker. Wherever the words “International Standard” appear, referring to this standard, they should be read as “British Standard”. The Technical Committee has reviewed the provisions of ISO 1101 and ISO 7649, to which reference is made in the text, and has decided that they are acceptable for use in conjunction with this standard. A related British Standard to ISO 1101 is BS 308 “Engineering drawing practice” Part 3 “Geometrical tolerancing”. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Cross-references International StandardCorresponding British Standard ISO 273:1979BS 4186:1984 Specification for clearance holes for metric bolts and screws (Identical) Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 8, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:05:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS AU 226:1988 © BSI 02-20001 1 Scope and field of application This International Standard specifies the nominal dimensions and tolerances of flywheel housings for reciprocating internal combustion engines, in particular those which affect inter-changeability with mating parts. It applies to reciprocating internal combustion engines except engines for aircraft and passenger cars. Flywheel housings of size codes 1 to 4 are recommended for commercial vehicles and buses. 2 References ISO 273, Fasteners Clearance holes for bolts and screws. ISO 1101, Technical drawings Geometrical tolerancing Tolerancing of form, orientation, location and run-out Generalities, definitions, symbols, indications on drawings. ISO 7649, Commercial vehicles Clutch housings for internal combustion engines Nominal dimensions and tolerances1). 3 Nominal dimensions and tolerances 3.1 Flywheel housing See Figure 1 and Table 1. Table 1 Flywheel housing dimensions and tolerances 1) At present at the stage of draft. Dimensions in millimetres Size code A Run-out (assembled flywheel housing)B Da nom.tol.tnom.min. 02 01 00 0 1/2 1 2 3 4 5 6 1 245 1 010,00 787,40 647,70 584,20 511,18 447,68 409,58 361,95 314,32 266,70 +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 applicable 0,47 0,39 0,35 0,31 0,27 0,25 0,25 0,25 0,25 1 400 1 165 883 711 648 553 489 451 404 356 308 10 10 8 8 8 8 8 8 8 8 8 NOTERun-out tolerances t shall be measured on the assembled engine mounted on its supports in accordance with the annex. (See ISO 1101 for definition of run-out.) a Dimension D relates to flywheel housings without rubber sealing. However, this dimension may be increased if a rubber seal is necessary. Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:05:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS AU 226:1988 2 © BSI 02-2000 3.2 Bolt or screw spacing and size 3.2.1 Dimensions and tolerances See Figure 1 and Table 2. Table 2 Tapped holes and bolt or screw spacing and dimensions Figure 1 Flywheel housing Size codeTapped holesRecommended thread engagement C nom. mm (see Figure 1 and Figure 2) NumberSize 02 01 00 0 1/2 1 2 3 4 5 6 24 24 16 16 12 12 12 12 12 8 8 M16 M16 M12 M12 M12 M10a M10 M10 M10 M10 M10 For cast iron flywheel housing 1,5 ×? nom. of bolt or screw For aluminium flywheel housing 2 ×? nom. of bolt or screw 1 340,00 1 105,00 850,90 679,45 619,12 530,12 466,72 428,62 381,00 333,38 285,75 NOTE24 tapped holes are optional for aluminium flywheel housings of size code 1. a M12 may be used for high engine torque applications. Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:05:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS AU 226:1988 © BSI 02-20003 3.2.2 Spacing Tapped holes shall be spaced equally on each side of the vertical and horizontal axis lines as shown in Figure 2. 4 Relationship of pilot bearing bore to flywheel housing The depth of the pilot bearing bore (see E in Figure 3) extends from the flywheel housing face to a shoulder in the flywheel, to a shoulder within the crankshaft or to the crankshaft flange face. Table 3 Depth of pilot bearing bore Figure 2 Bolt or screw hole spacing Dimensions in millimetres Size code E nom. E nom. optional for: double plate clutches when extra-heavy flywheel is used overcentre clutch 02 01 00 0 1/2 1 2 3 4 5 6 265 265 100 100 100 100 112a 100 112a 100 100 71 71 133,4 133,4 133,4 133,4 71 100 a An E dimension of 112 mm is optional for flywheel housing size codes 1 and 2 when the clutch shaft bearing is located in the pilot bearing bore of the flywheel or crankshaft end, i.e. when the bearing is not located in a separate carrier. Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:05:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS AU 226:1988 4 © BSI 02-2000 5 Mating part flange (for example, clutch housings) The dimensions and tolerances of clutch housings for reciprocating internal combustion engines are given in ISO 7649. Limits and fits of the pilot diameter of the mating part are at the discretion of the manufacturer of that component. The manufacturer shall also specify the tolerances of form and position of the mating part flange. The clearance holes of the mating part flange shall have the same location as specified under 3.2.2 and shall be in accordance with ISO 273. Figure 3 Depth of pilot bearing bore Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:05:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS AU 226:1988 © BSI 02-20005 Annex Procedure for measuring bore eccentricity and face deviation (This annex forms an integral part of the Standard.) A.1 Scope This annex provides a uniform procedure for measuring bore eccentricity and face deviation (run-out) of flywheel housings after assembly to an engine. Limits of bore eccentricity and face deviation are given in Table 1. A.2 Measuring procedures A.2.1 General A.2.1.1 A dial indicator with rigid extension bars is required. A.2.1.2 Surfaces which are to be measured shall be free from dirt and burrs. A.2.1.3 Prepare a chart as shown in Table 4 to help in determining bore eccentricity. A.2.2 Eccentricity of housing A.2.2.1 Mount the indicator base on the flywheel or crankshaft flange as close as possible to the housing pilot bore to minimize deflection. A.2.2.2 Adjust the indicator point to be perpendicular to the housing pilot bore and set at zero in the 6 o½clock (mandatory) position (lower vertical). A.2.2.3 Slowly rotate the crankshaft and record the indicator reading along with the appropriate positive or negative sign at the 9 o½clock (a), 12 o½clock (b), and 3 o½clock (c) locations. Confirm that the 6 o½clock reading is still zero. Record the readings on line A in Table 4, being sure to include the positive or negative sign. Table 4 Data chart CAUTION Sign designation relative to direction of indicator tip movement is not the same for all indicators. For all measurements in the calculations carried out in accordance with A.2.2, outward movement of the indicator tip with respect to the centre of the bore being measured is to be considered a negative reading. Designation6 o½clock9 o½clock12 o½clock3 o½clock A B C D E F Observed indicator reading Adjustment for bearing clearance Half-bearing clearance adjustment Total corrected vertical indicator reading Corrected horizontal indicator reading Total horizontal indicator reading 0 Iv= IH= a = d/2 = E1= b = d = c = d/2 = E2 IV= b + d E1= a + d/2 E2= c + d/2 IH= E1 E2 IRIv()2IH()2+= Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:05:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS AU 226:1988 6 © BSI 02-2000 A.2.2.4 Position the indicator at the 12 o½clock location and determine d, the adjustment for clearance in the main bearing adjacent to the flywheel, by an appropriate method, for example by raising the crankshaft to its upper limit. Record the adjustment for bearing clearance on line B in Table 4 in the 12 o½clock column. This value shall always be positive. NOTEA floor-mounted support with a padded prybar or other suitable means can be used to raise the flywheel; however it should not be forced beyond the point where the bearing clearance has been removed, nor should the housing be used as a fulcrum. A.2.2.5 Correct the 12 o½clock reading obtained in A.2.2.3 by algebraically adding the adjustment for bearing clearance to it. This is the corrected total vertical indicator reading (IV). Record this value on line D in Table 4. A.2.2.6 Correct the 3 o½clock and 9 o½clock readings from A.2.2.3 by algebraically adding an amount equal to one-half of the adjustment for bearing clearance determined in A.2.2.4 to each of them. This can be done by taking the clearance adjustment determined in A.2.2.4, dividing it by two, and entering it on line C in the 3 o½clock and 9 o½clock columns. Again, this value will always be positive. The readings, corrected for bearing clearance, can then be obtained by algebraically summing the values in lines A and C of the 3 o½clock and 9 o½clock columns. These values shall be denoted as E1 and E2 and entered on line E in Table 4. A.2.2.7 Determine the horizontal indicator reading (IH) by taking the algebraic difference between the corrected 3 o½clock and 9 o½clock readings (IH= E1 E2). This value is to be entered on line F in Table 4. Figure 4 Resultant total indicator reading, IR Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:05:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS AU 226:1988 © BSI 02-20007 A.2.2.8 Determine the resultant total indicator reading (IR) of the housing or adapter by locating the intersection point of the total vertical indicator reading (IV) and the total horizontal indicator reading (IH) in Figure 4, or calculate as follows: IR= Æ(Iv)2+ (IH)2 NOTEThis value (IR) is consistent with a total indicator type reading as are the limits specified in Table 1. It is not eccentricity as such. Actual eccentricity is equal to one-half of this value. A.2.3 Face deviaton of housing A.2.3.1 Mount the indicator base in accordance with A.2.2.1. A.2.3.2 Adjust the indicator point to be perpendicular to the face. A.2.3.3 After eliminating the crankshaft end play, e.g., by tilting the crankshaft or by inclining the engine approximately 15° to 20°, set the dial indicator to zero in the 6 o½clock (not mandatory) position. A.2.3.4 Taking care to keep the end play eliminated in the same direction as in the 6 o½clock position, rotate the crankshaft one complete revolution to determine the total indicator reading. A.2.3.5 Compare the total indicator reading with the limit specified in Table 1. Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:05:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 8 blank Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:05:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS AU 226:1988 © BSI 02-2000 Publications referred to See national foreword. Licensed Copy: London South Bank University, London South Bank University, Sat Dec 09 02:05:10 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS AU 226:1988 ISO 7648:1987 BSI 389 Chiswick High Road London W4 4AL BSI British Standar