A variator drive consists of adjustable pulleys with a variator belt running through them. This belt can adjust flexibly to the grooves in the pulley. In addition, this belt boasts a high transfer performance and can be used for a wide range of different speeds and speed ratios. Variator belts are made from polychloroprene (PCP) while the tension cords are made from polyester (PES). The toothing on the inside of the belt makes it extremely flexible, ensuring a high degree of heat dissipation to keep the running temperature at a low level. The lateral rigidity of the belt prevents it from deforming inside the pulley. This structural stability ensures that the load is distributed evenly and reduces wear.
Variator belts are used mainly in mechanical engineering, in agricultural machines and in textile machines.
Several factors determine which V-belt type is best suited to a particular drive. These include the application (what is being driven?), the power to be transferred, the desired speed (acceleration or deceleration) as well as the centre distance of the pulleys and any possible impact loads. It is also important to know what ambient conditions are present and whether there are any space limitations (what is the maximum permissible diameter and width of the pulleys?).
It is very important that the V-belt is pre-tensioned correctly for optimal drive function. Tension can be measured with a testing device, such as the Sonic Tension Meter. This uses sound waves transmitted by the belt to determine its vibration frequency and then calculates a tension value from this. As well as correct tensioning, it is important that the pulleys are aligned correctly: this is done with a laser-guided alignment system.
Common standards for V-belt drives include DIN 2211, DIN 2217, DIN 7867, ISO 4183, ISO 5290 and ISO 9981. Finally, an important consideration is whether the V-belts need to be statically conductive in accordance with ISO 1813 (ATEX environments).