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.
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.
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.
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.
You may see also:
