optibelt KS for Cylindrical Bores

Optibelt V-groove pulleys are available in the narrow V-belt profiles SPZ, SPA, SPB, and SPC. While V-belts differ in their overall height, there are no differences between the pulley grooves (groove dimensions) for narrow V-belts according to DIN 7753 Part 1 or classic V-belts according to DIN 2215 and DIN 2216. The groove dimensions are specified so that all internationally standardized V-belts with the narrow V-belt profile, as well as those with the corresponding classic profile, can be used.

• SPZ / 10
• SPA / 13
• SPB / 17
• SPC / 22

The datum diameter is the most important test criterion for a V-groove pulley. It refers to the diameter corresponding to the width of the pulley groove. Unlike the outer diameter, the datum diameter is measured within the profile. Its position is determined by the tension strand of the V-belt in contact with the pulley. The datum diameter is the key parameter for calculating the transmission ratio.

To ensure a long belt life and economical operation of the drive, the pulley diameters should be selected as large as possible. The recommended minimum pulley diameters must be observed. However, the belt speed should not exceed v = 30 m/s for standard V-belts or v = 40 m/s for narrow V-belts, as the belts achieve their optimal power transmission within this range.

The optibelt standard range includes V-grooved pulleys with one to twelve grooves, depending on the profile and center diameter. The grooves on optibelt KS V-grooved pulleys are manufactured in accordance with DIN 2211. A complete overview of the geometric specifications for optibelt KS V-grooved pulleys can be found in the Technical Manual for V-belt Drives.

Optibelt standard V-groove pulleys are available as solid, plate, or spoked pulleys. It should be noted that solid and flat-bottom pulleys generally achieve higher permissible circumferential speeds than flanged pulleys.

Optibelt standard V-grooved pulleys are manufactured in accordance with the ISO 254 quality standard. The pulleys are available in Taper-Bushings versions or with cylindrical bores. Versions with cylindrical bores are always delivered pre-bored and can, upon request, be equipped with a finished bore in accordance with DIN, including keyways, as well as mounting threads for adjusting screws on request.

Detailed information on the respective design can be found in the corresponding design drawings, which provide details on the specific design of the selected pulley.

All standard gray cast iron V-grooved pulleys are statically balanced — that is, in a single plane — to grade G16 and can be used in applications with speeds up to 30 m/s. Balancing is performed in accordance with DIN ISO 21940. Dynamic balancing in two planes to grade G6.3 is recommended if the belt speed v > 30 m/s or if the ratio of the straight diameter to the pulley rim width is less than 4 at v > 20 m/s.

In all cases, the maximum permissible belt speed and the maximum circumferential speed of the respective V-grooved pulley must be observed. Alternative material grades and special designs are available for higher rotational speeds. Before installation, shafts and V-grooved pulleys should also be aligned.

Shafts and V-grooved pulleys must be aligned before installation. It is also important to replace damaged pulleys or pulleys with clearly visible wear in good time to prevent premature belt failure. We recommend replacing V-grooved pulleys when changing the belt for the third time.

The optibelt belt and groove gauges allow for quick and easy identification of V-belts and V-grooved pulleys. They also enable reliable determination of profiles and inspection of the wear condition of pulleys.

Our standard V-grooved pulleys are mainly made of gray cast iron (material EN-GJL 200 - DIN EN 1561). In some versions, depending on size, black oxided steel is also used. Compared to aluminum, gray cast iron is characterized by higher wear resistance and does not become shiny as quickly. This ensures consistently optimal static friction. In addition, the material provides good damping of shock torques and contributes to smooth, quiet operation of the drive. The surface phosphating of the gray cast iron pulleys also ensures increased corrosion resistance.

In addition to our standard gray cast iron V-grooved pulleys, we also offer numerous other material and surface options. Our application engineers will be happy to advise you on your specific requirements.