Machinery's Handbook, 31st Edition
2626 Transmission Roller Chains Selection of Chain and Sprockets.— The smallest applicable pitch of roller chain is desir- able for quiet operation and high speed. The horsepower capacity varies with the chain pitch as shown in Table 9 for 1 ⁄ 4 , 3 ⁄ 8 , and 1 ⁄ 2 in pitch designs. However, short pitch with high working load can often be obtained by the use of multiple-strand chain. The small sprocket selected must be large enough to accommodate the shaft. Table 10 gives maximum bore and hub diameters consistent with commercial practice for sprock- ets with up to 25 teeth. After selecting the small sprocket, the number of teeth in the larger sprocket is deter mined by the desired ratio of the shaft speed. Overemphasis on the exactness in the speed ratio may result in a cumbersome and expensive installation. In most cases, satisfactory operation can be obtained with a minor change in speed of one or both shafts. Table 9. Horsepower Ratings for Roller Chain, ANSI/ASME B29.1-2011 (R2016) To properly use this table the following factors must be taken into consideration: 1) Service factors 2) Multiple Strand Factors 3) Lubrication Service Factors: See Table 15. Multiple Strand Factors: For two strands, the multiple strand factor is 1.7; for three strands, it is 2.5; and for four strands, it is 3.3. Lubrication: Required type of lubrication is indicated at the bottom of each roller chain size section of the table. For a description of each type of lubrication, see page 2638.
Type A — Manual or Drip Lubrication Type B — Bath or Disc Lubrication Type C — Oil Stream Lubrication To find the required horsepower table rating, use the following formula: Required hp TableRating
Multiple Strand Factor hp to be Transmitted Service Factor # = −
Revolutions per Minute — Small Sprocket a 50 100 300 500 700 900 1200 1500 1800 2100 2500 3000 3500 Horsepower Rating 11 0.03 0.06 0.19 0.30 0.42 0.53 0.70 0.87 1.03 1.20 1.42 1.69 1.69 12 0.04 0.07 0.20 0.33 0.46 0.58 0.76 0.95 1.13 1.31 1.55 1.84 1.92 13 0.04 0.08 0.22 0.36 0.49 0.63 0.83 1.03 1.22 1.42 1.67 1.99 2.17 14 0.04 0.08 0.24 0.38 0.53 0.68 0.89 1.10 1.32 1.52 1.80 2.15 2.42 15 0.05 0.09 0.25 0.41 0.57 0.72 0.95 1.18 1.41 1.63 1.93 2.30 2.67 16 0.05 0.09 0.27 0.44 0.61 0.77 1.02 1.26 1.50 1.74 2.06 2.45 2.85 17 0.05 0.10 0.29 0.47 0.64 0.82 1.08 1.34 1.60 1.85 2.19 2.61 3.02 18 0.05 0.11 0.30 0.49 0.68 0.87 1.15 1.42 1.69 1.96 2.32 2.76 3.20 19 0.06 0.11 0.32 0.52 0.72 0.92 1.21 1.50 1.78 2.07 2.45 2.91 3.38 20 0.06 0.12 0.34 0.55 0.76 0.97 1.27 1.58 1.88 2.18 2.58 3.07 3.56 21 0.06 0.12 0.35 0.58 0.80 1.01 1.34 1.66 1.97 2.29 2.70 3.22 3.74 22 0.07 0.13 0.37 0.60 0.83 1.06 1.40 1.73 2.07 2.40 2.83 3.37 3.91 23 0.07 0.13 0.39 0.63 0.87 1.11 1.46 1.81 2.16 2.51 2.96 3.53 4.09 24 0.07 0.14 0.40 0.66 0.91 1.16 1.53 1.89 2.25 2.61 3.09 3.68 4.27 25 0.08 0.15 0.42 0.69 0.95 1.21 1.59 1.97 2.35 2.72 3.22 3.84 4.45 26 0.08 0.15 0.44 0.71 0.99 1.26 1.65 2.05 2.44 2.83 3.35 3.99 4.62 28 0.08 0.16 0.47 0.77 1.06 1.35 1.78 2.21 2.63 3.05 3.61 4.30 4.98 30 0.09 0.18 0.50 0.82 1.14 1.45 1.91 2.37 2.82 3.27 3.86 4.60 5.34 32 0.10 0.19 0.54 0.88 1.21 1.55 2.04 2.52 3.01 3.49 4.12 4.91 5.69 35 0.11 0.21 0.59 0.96 1.33 1.69 2.23 2.76 3.29 3.81 4.51 5.37 6.23 40 0.12 0.23 0.67 1.10 1.52 1.93 2.55 3.15 3.76 4.36 5.15 6.14 7.11 45 0.14 0.26 0.76 1.24 1.71 2.17 2.86 3.55 4.23 4.90 5.79 6.90 8.00 Type A Type B Type C
No. of Teeth Small Spkt.
Copyright 2020, Industrial Press, Inc.
ebooks.industrialpress.com
Made with FlippingBook - Share PDF online