Ribbed belts, also called micro-V-belts, are supple belts that are often used in compact and highly stressed drives. The range of ribbed belts includes the profiles PH, PJ, PK, PL and PM. There is a wide range in terms of the number of ribs. The belts include polyester (PES) tension cords with a low elongation factor, resulting in a good resistance to material fatigue and impact loads.
The ribs are flattened, which provides flexibility as well as a reduction in heat development and increases the resistance of the belt to crack formation. The elastomer compound from which the belt is manufactured provides resistance to oil and heat.
Although an outer tensioner and slave roller in a drive always has a negative influence on the service life of the belt, the abovementioned properties of the ribbed belt ensure that it is more resistant to this.
Thanks to all these properties ribbed belts are suitable for drives in washing machines, textile machines, vacuum cleaners, lawnmowers, machine tools and machines for medical applications.
When calculating a ribbed belt drive, different factors determine whether a type PH, PJ, PK, PL or PM belt is best, for example the application, the power to be transmitted, the desired speed (acceleration or deceleration), 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 width and diameter of the pulleys?).
Common standards for V-belt drives include DIN2211, DIN2217, DIN7867, ISO4183, ISO5290 and ISO9981. Finally it is important whether the V-belts need to be static-conductive to meet ISO1813 (ATEX environments).