Overview
ISO 3410:1989 (second edition) specifies the main dimensions, tolerances and measurement methods for endless variable-speed V-belts and the groove sections of the corresponding pulleys used in agricultural machinery - in particular harvester‑threshers. This edition cancels and replaces ISO 3410:1976 and provides nominal datum belt lengths from 630 mm up to 5 000 mm, figures for section shapes and guidance on measurement devices and test procedures.
The standard was prepared by ISO/TC 41 (Pulleys and belts) and references related international standards for normal numbers, belt terminology and test methods.
Key Topics
- Scope and purpose: Dimensions for V-belts intended for variable‑speed drives on agricultural machines and matching pulley groove profiles (fixed or variable diameter).
- Belt section characteristics: Sections are described by a relative flank height (height/primitive width) typically around 0.5, with the primitive line positioned about one third of the profile height below the large side of the trapezoid.
- Nominal lengths: Reference (datum) lengths tabulated from 630 mm to 5 000 mm following the R40 series of normal numbers; intermediate values may use R80.
- Tolerances and length control: The standard gives permissible length deviations and a method to compute an allowance parameter p (formula shown in the text) and prescribes procedures for checking length and center‑distance variation.
- Pulleys and profiles: Defines profiles (HG…HO) and minimum pulley diameters and radial groove dimensions for types of pulleys: type 1 (fixed), type 2 (variable) and type 3 (variable with declutching flange).
- Measurement methods: Recommends a measuring device of two functional grooved pulleys (one movable under traction F) - run the belt for at least two revolutions and measure center distance E to compute the reference length Ld = 2E + Cd.
Applications
- Designed specifically for agricultural drive systems, notably combine harvester-threshers and other variable-speed transmissions.
- Ensures interchangeability, consistent manufacturing and reliable power transmission where belts experience large local deformation entering pulley grooves.
- Useful for manufacturers, drive-system designers, test labs and procurement teams specifying belt and pulley dimensions, tolerances and acceptance tests.
Related Standards
- ISO 3 - Normal numbers (series R 10, R 40, R 80) referenced for nominal lengths
- ISO 1081 - Terminology for V‑belts and grooved pulleys
- ISO 9608 - Belt uniformity and center-distance variation test method
- ISO 286-2 - Tolerance system referenced for probe diameters and fits
Use ISO 3410:1989 to align belt and pulley designs with international practice, enabling robust variable‑speed V‑belt drives for agricultural machinery.
Open preview (PDF)Agricultural machinery — Endless variable-speed V-belts and groove sections of corresponding pulleys