ISO 19347:2015 pdf free
ISO 19347:2015 pdf free.Synchronous belt drives一Imperial pitch trapezoidal profile system一Belts and pulleys
Synchronous belts are identified by a standard number. The first digits specify the pitch length which for the XL and larger pitch belts contained in this standard is the calculated pitch length in inches (the pitch length in millimetres divided by 25,4) times 10 rounded off to the nearest whole integer. For MXL and XXL belts, it is the calculated pitch in inches (the pitch length in millimetres divided by 25,4) times 10 rounded off to the nearest tenth. The pitch length is followed by the profiles designation. The digits following the profile designation represent the nominal belt width in inches times 100 rounded off to the nearest 3 digits.
The length designation for belts in non-standardized lengths that are not contained in Tables 3 and 4 shall be established from the pitch length in millimetres divided by 2,54. This number shall be rounded as follows:
a) for belts with profile MXL to the first decimal: for example belt MXL with 102 teeth corresponding to pitch length 207,26 mm: length designation 816.
An alternative method for belts with profile MXL or XXL consists of using the letter B (for belt) followed by the number of teeth, which gives the length designation B 102.
b) for belts with profile XL to XXH to the nearest integral number, where 0,5 will be rounded down, for example belt L with 130 teeth corresponding to pitch length 1 238,25 mm: length designation 487.
The pitch length of a synchronous belt shall be determined by placing the belt on a measuring fixture composed of the following elements (see Figure 5).
Two pulleys of equal diameter as specified in Table z of the proper pitch code, and having standard tooth space dimensions. These pulleys shall be made to the tolerances shown in Table 7 and have the proper clearance, Cm, between the pulley tooth space and the theoretical belt tooth width as specified in Table 7(see Figure 4). One pulley shall be free to rotate on a fixed-position shaft, while the other shall be free to rotate on a movable shaft to permit the centre distance to change.ISO 19347 pdf download.
