V-belts are available in numerous variants and dimensions. The best-known are the traditional encased V-belt and the toothed narrow V-belt, also called a raw-edged, moulded notched V-belt. These belts are available with the following profiles: Z, A, B, C and D, SPZ, SPA, SPB and SPC, as well as XPZ, XPA, XPB and XPC.
Most V-belts are also available in a variant known as Powerband.
The tension cords integrated into the V-belt are one of the factors that determines belt strength. The production material depends on the type of V-belt. Most belts are made from polychloroprene (PCP), while the tension cords are mostly made of polyester (PES) and, in one case, from aramid. Aramid has an extremely low elongation propensity, meaning very high performance transmission can be achieved.
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?).
V-belt drives can slip to a certain extent, but this is not necessarily a problem. It can even be desirable in some cases as a type of safety measure. If absolutely no slip can be tolerated, toothed belts or chain drives are among the options.
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. Although V-belts generally require re-tensioning after a specific run-in period or operating time, some V-belts—such as the Quad-Power® 4—require no maintenance at all. After setting the initial pre-tension on this V-belt, no further re-tensioning is necessary.
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).
