Pulleys - Hubs - Sprockets

Frequently asked questions — Pulleys, Hubs and Sprockets

• What is the difference between key fixing and Taper Lock fixing?

  Fixing by parallel key DIN 6885 is a standard and economical solution; however, it requires the use of a puller during dismantling operations. Conversely, the removable Taper Lock hub system, available in series 1008 to 5050, facilitates maintainability through quick dismantling via set screws. This mechanism also makes it easier to adapt the bore to the rotating shaft.
• Why choose a number of teeth equal to or greater than 17 for roller sprockets?

  When using sprockets for chains compliant with ISO 606 or ANSI B29.1 standards, it is recommended to select a number of teeth (Z) equal to or greater than 17. This technical threshold is decisive in limiting premature wear of the standardised tooth profile. The chosen number of teeth directly determines the transmission ratio as well as the overall durability of the system.
• How to choose between GG-20 cast iron and aluminium pulleys?

  Material selection is primarily based on the weight constraints of the equipment. Pulleys for V-belts are mostly manufactured from grey cast iron GG-20, which is the standard for these components. When technical requirements call for weight reduction of the entire mechanical transmission, aluminium is selected as an alternative material.
• How to prevent run-off of a synchronous belt?

  For toothed synchronous pulleys (HTD, STD, AT, GT, MXL/XL/L/H profiles), the stability of the transmission is ensured by the pitch matching the belt profile. In the specific case of mounting on a horizontal shaft, it is recommended to use pulleys fitted with side flanges. These physical elements prevent the belt from running off during operation, thereby maintaining the interface between the flexible elements and the rotating shafts.
• When should an oil-pressure clamping bush be used?

  The choice of fixing method determines the maintainability and safety of the mechanical transmission. Although the DIN 6885 key and the Taper Lock hub cover most requirements, fixing by oil-pressure clamping bush is specifically reserved for large-sized components. This device provides clamping suited to the high mechanical stresses encountered on these significant dimensions.