These pulleys are used to transmit power between parallel axles by connecting them with a v-belt. V-belts (or vee-belts) consist of repeating trapezoidal cross-sections of any number from 1 to 10 or more, corresponding to the grooves of the pulley. These systems provide efficient energy transmission (up to 98% is possible), high-speed performance, and excellent traction that reliably resists slipping or misalignment.

Most of the SPB section steel pulley units in this range are taper bored to accept taper-lock shaft fixing bushes (which are available separately). The choice of separate bushing enables each pulley to be fitted to a range of shaft diameters - whether metric or imperial.

Identifying profiles and sizes

If you're replacing an existing pulley, belt and sheave profiles usually employ a standard nomenclature which usually forms part of the SKU (model number) printed or engraved on the item you're replacing. Alternatively, it is often possible to identify the pulley or belt from the model number of the machinery into which they are fitted, but our personnel are always happy to look up this information for you.

If you need to identify a suitable part from its dimensions, the measurements that define a pulley include the number of grooves, groove pitch, pitch diameter, the hub width (or bush seat length), and sheave depth. Many of the products have accompanying technical diagrams that will assist you in this.

Note that although v-belts can physically be fitted onto pulleys of almost any diameter, the range of suitably sized pulleys is determined by the load and speed intended for the system. A pulley that is too small increases shear forces on the belt and also has to rotate faster, therefore generating more heat. Again, if you have any uncertainties our personnel are happy to provide advice.

Compatibility

Our range of SPB section steel pulleys correspond to our comprehensive range of SPB section v-belts. However the same pulleys are often suitable for use with standard B section v-belts as well. The teeth of an SPB belt are set at 38 degrees, whereas those of a B profile belt are 34 degrees, but this simply means they sit in the sheaves of the pulley differently - a sometimes useful characteristic. The same SPB section steel pulleys also work with specialised belts such as a cogged raw edge wedge belts.

SPB section steel pulley units are metric and defined in millimetres, but have imperial equivalents. For example, a "B" profile has a top width of 0.625". Again, it is often possible to find a compatible match for equipment originally specified in imperial.

We also stock SPA, SPC and SPZ section belts and pulleys, and matching taper-lock bushings (see those sections), and Simply Bearings are also happy to locate other sizes and profiles not already listed.

Simply Bearings only source top quality components because we believe reliability is paramount. You can have confidence these pulleys are fully compatible high performance replacements for products with other brand names.