ISO 9981 pdf download

ISO 9981 pdf download.Belt drives — Pulleys and V-ribbed belts for the automotive industry — PK profile: Dimensions 1 Scope This International Standard specifies the principal dimensional characteristics of V-ribbed pulley groove profiles, together with the corresponding endless V-ribbed belts of PK profile which are used predominantly for automotive accessory drive applications. The complete array of V-ribbed belts and pulleys of PH, PJ, PK, PL and PM profile for industrial and other non- automotive applications is the subject of ISO 9982. PK belt profile dimensions and tolerances are the same in both International Standards. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of the publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on the International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 254:1 998, Belt drives — Pulleys — Quality, finish and balance . ISO 4287:1 997, Geometrical product specification (GPS) — Surface texture: Profile method — Terms, definitions and surface texture parameters . 3 Pulleys 3.1 Groove dimensions and tolerances The groove dimensions of PK pulleys are shown in figures 1 and 2, and given in table 1 . 3.2 Minimum effective diameter The minimum recommended effective diameter, d e , for PK pulleys is 45 mm. 3.3 Tolerances on finished pulley 3.3.1 Checking conditions Profile, diameter and run-out tolerances shall be checked on the finished pulley without surface coating. 3.3.2 Groove-to-groove diameter tolerances The variation in diameters between the grooves in any one pulley shall not exceed 0,1 5 mm. This variation is obtained by comparing the diameters over balls or rods. 3.3.3 Radial and axial circular run-out Radial and axial circular run-outs shall not exceed 0,25 mm full indicator movement (FIM). Run-out in the two directions is measured separately with a ball mounted under spring pressure to ensure contact with the groove as the pulley is rotated. 3.3.4 Diameter over balls The tolerances on the diameters over balls (K) shall not exceed ± 0,6 mm. 3.3.5 Groove finish The pulley grooves shall have a surface roughness Ra ¶ 3,2 µm. See ISO 254 and ISO 4287 for definitions and the method of measurement.3.4 Pitch diameter, d p The fit...