Machinery's Handbook, 31st Edition
Classical V-Belts
2581
Table 12. Arc of Contact Correction Factors
Correction Factor V-V V-Flat a
Correction Factor V-V V-Flat a
C D d d d − Arc of Contact, θ , Small Sheave (deg)
C D d d d − Arc of Contact, θ Small Sheave (deg)
0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70
180 174 169 163 157 151 145 139
1.00 0.99 0.97 0.96 0.94 0.93 0.91 0.89
0.75 0.76 0.78 0.79 0.80 0.81 0.83 0.84
0.80 0.90 1.00 1.10 1.20 1.30 1.40 1.50
133 127 120 113 106
0.87 0.85 0.82 0.80 0.77 0.73 0.70 0.65
0.85 0.85 0.82 0.80 0.77 0.73 0.70 0.65
99 91 83
a A V-flat drive is one using a small sheave and a large diameter flat pulley. Double V-Belts ANSI/RMA IP-21.— Double V-belts or hexagonal belts are used when power input or takeoff is required on both sides of the belt. Designed for use on “serpen tine” drives, which consist of sheaves rotating in opposite directions, the belts are avail - able in AA, BB, CC, and DD cross sections and operate in standard classical sheaves. They are specified by cross section and nominal length. Belt Cross Sections: Nominal dimensions of the four cross sections are given in Fig. 5. Belt Size Designation: Double V-belt sizes are identified by a standard belt number, con sisting of a letter-numeral combination. The letters identify the cross section; the numbers identify length as shown in Column 1 of Table 13. For example, AA51 indicates an AA cross section and a standard length designation of 51. Table 13. Double V-Belt Standard Effective Lengths ANSI/RMA IP-21, 1984 Standard Length Designation a Standard Effective Length Permissible Deviation from Standard Effective Length Matching Limits for One Set Cross Section AA BB CC DD
51 55 60 68 75 80 81 85 90 96 97
53.1 53.9 … 57.9 62.1 62.9 70.1 70.9 77.1 77.9
… … … … … … … … … …
0.15 0.15 0.15 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.30 0.45 0.45 0.45 0.45 0.45 0.45 0.60 0.60 0.60
± 0.7 ± 0.7 ± 0.7 ± 0.7 ± 0.7 ± 0.7 ± 0.7 ± 0.7 ± 0.8 ± 0.8 ± 0.8 ± 0.8 ± 0.8 ± 0.8 ± 0.8 ± 0.8 ± 1.0 ± 1.0 ± 1.0 ± 1.1 ± 1.1 ± 1.3 ± 1.6 ± 1.6 ± 2.0 ± 2.0
82.1
… … …
… 83.9 85.2 87.1 87.9 89.2 92.1 92.9 94.2
… … … … … …
98.1
… 100.2
… 99.9
… …
105 112 120 128 144 158 173 180 195 210 240 270 300 330 360
107.1 107.9 109.2 114.1 114.9 116.2
122.1 122.9 124.2 125.2 130.1 130.9 132.2 133.2 … 146.9 148.2 149.2 … 160.9 162.2 163.2 … 175.9 177.2 178.2 … 182.9 184.2 185.2 … 197.9 199.2 200.2 … 212.9 214.2 215.2 … 241.4 242.2 242.7 … 271.4 272.2 272.7 … 301.4 302.2 302.7 … … 332.2 332.7
… … 362.2 362.7 0.60 a To specify belt size use the Standard Length Designation prefixed by the letters indicating cross
section; for example, BB90. All dimensions in inches.
Sheave Dimensions: Groove angles and dimensions for sheaves and face widths of sheaves for multiple belt drives are given in Table 14, along with various tolerance values.
Copyright 2020, Industrial Press, Inc.
ebooks.industrialpress.com
Made with FlippingBook - Share PDF online