Classical V-belts


Classical V-belts are most commonly used in heavy-duty applications and include these standard cross sections: A, AX, B, BX, C, CX, D, and DX (Fig. 3). Top widths range from 1 ⁄ 2 to 11 ⁄ 4 in. and are specified by cross section and nominal length. Classical belts can be teamed in multiples of two or more. These multiple drives can transmit up to several hundred horsepower continuously and absorb reasonable shock loads. 

Belt Cross Sections: Nominal dimensions of the four cross sections are given in Fig. 3. 

Belt Size Designation: Classical V-belt sizes are identified by a standard belt number consisting of a letter-numeral combination. The letter identifies the cross section; the numeral identifies the length as shown in Table 8. For example, A60 indicates an A cross section and a standard length designation of 60. An X following the section letter designation indicates a molded notch cross section, for example, AX60.

Classical v-belts

Classical v-belts

Sheave Dimensions: Groove angles and dimensions for sheaves and the face widths of sheaves for multiple belt drives are given in Table 9, along with various tolerance values.

Classical v-belts

Classical v-belts

Minimum Sheave Size: The recommended minimum sheave size depends on the rpm of the faster shaft. Minimum sheave diameters for each cross-section belt are listed in Table 9. 

Cross Section Selection: Use the chart (Fig. 4) as a guide to the Classical V-belt cross section for any combination of design horsepower and speed of the faster shaft. When the intersection of the design horsepower and speed of the faster shaft falls near a line between two areas on the chart, the possibilities in both areas should be investigated. Special circumstances (such as space limitations) may lead to a choice of belt cross section different from that indicated in the chart.

Classical v-belts

Number of Belts: The number of belts required for an application is obtained by dividing the design horsepower by the corrected horsepower rating for one belt. 

Arc of Contact: Arc of contact on the small sheave may be determined by the formulas.

where Dd = Datum diameter of large sheave or flat pulley, inch; dd = Datum diameter of small sheave, inch; and, C = Center distance, inch.

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