ISO 2790:2020 pdf download Belt drives — V-belts for the automotive industry and corresponding pulleys — Dimensions
1 Scope
This document specifies the requirements for belts and pulleys for V-belt drives used for driving auxiliaries of internal combustion engines for the automotive industry.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 1081, Belt drives — V-belts and V-ribbed belts, and corresponding grooved pulleys — Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 1081 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
4 Belts
4.1 General
A belt is defined by its cross-section, type and by its effective length in millimetres measured under specified conditions. Cogged belt is represented by X.
Belt types are given in Figure 1.
4.2 Cross-section
A cross-section of a belt is defined by the nominal top width, w (see Figure 2 and Table 1).
4.3 Measurement of the effective length of a belt and its ride-out Set the belt up on two identical pulleys, having the dimensions shown in Table 2 and mounted on a horizontal bench, and apply to the sliding pulley the measurement force, F, (see Figure 3). To measure the effective length of a belt, rotate the belt at least twice to seat it properly and to divide the total force equally between the two strands of the belt. Then measure the centre distance between the two strands of the belt. The effective length of the belt, L e , is given by Formula (1).ISO 2790:2020 pdf download