Transmission Roller Chains Machinery's Handbook, 31st Edition
2636
Yab ( ) cos
Yab ( ) sin
=
1.4 D r
=
1.4 D r
W
V
116 ° N a ------
56 ° N a – ----
yz D r 1.4 17 ° sin =
0.8 18 °
+
Yab –
– sin
56 ° N a – ----
116 ° N a ------
1.4 17 ° + cos
– 1.3025
F D r 0.8 18 ° cos =
+
Yab –
–0.0015 in.
For other points, use the value of N a for N in the standard formulas in Table 11. Table 14. Recommended Space Cutter Sizes for Roller-Chain Sprockets
Number of Teeth
6
7-8
9-11
12-17
18-34
35 up
Pitch 0.250 0.375 0.500 0.625 0.725 1.000 1.250 1.500 1.750 2.000 2.250 2.500 3.000 Pitch 0.250 0.375 0.500 0.625 0.750 1.000 1.250 1.500 1.750 2.000 2.250 2.500 3.000
Roller Dia.
Cutter Diameter (Minimum)
0.130 0.200 0.312 0.400 0.469 0.625 0.750 0.875 1.000 1.125 1.406 1.563 1.875 0.130 0.200 0.312 0.400 0.469 0.625 0.750 0.875 1.000 1.125 1.406 1.563
2.75 2.75 3.00 3.12 3.25 3.88 4.25 4.38 5.00 5.38 5.88 6.38 7.50 0.31 0.47 0.75 0.75 0.91 1.50 1.81 1.81 2.09 2.41 2.69 3.00
2.75 2.75 3.00 3.12 3.25 4.00 4.38 4.50 5.12 5.50 6.00 6.62 7.75 0.31 0.47 0.75 0.75 0.91 1.50 1.81 1.81 2.09 2.41 2.69 3.00
2.75 2.75 3.12 3.25 3.38 4.12 4.50 4.62 5.25 5.62 6.25 6.75 7.88 0.31 0.47 0.75 0.75 0.91 1.47 1.78 1.78 2.06 2.38 2.66 2.94
2.75 2.75 3.12 3.25 3.38 4.12 4.50 4.62 5.38 5.75 6.38 6.88 8.00 0.31 0.44 0.75 0.75 0.88 1.47 1.75 1.75 2.03 2.31 2.59 2.91
2.75 2.75 3.12 3.25 3.38 4.25 4.62 4.75 5.50 5.88 6.50 7.00 8.00 0.28 0.44 0.72 0.72 0.84 1.41 1.69 1.69 1.97 2.25 2.47 2.75
2.75 2.75 3.12 3.25 3.38 4.25 4.62 4.75 5.50 5.88 6.50 7.12 8.25 0.28 0.41 0.69 0.69 0.81 1.34 1.62 1.62 1.88 2.16 2.41 2.69
Roller Dia.
Cutter Width (Minimum)
1.875 3.22 Where the same roller diameter is commonly used with chains of two different pitches it is recommended that stock cutters be made wide enough to cut sprockets for both chains. 3.59 3.59 3.53 3.47 3.34 Marking of Cutters. —All cutters are to be marked, giving pitch, roller diameter and range of teeth to be cut. Bores for Sprocket Cutters (recommended practice) are approximately as calculated from the formula: Bore 0.7 Width of Cutter Roller Diameter 0.7Pitch = + + ^ h and are equal to 1 inch for 1 ∕ 4 - through 3 ∕ 4 -inch pitches; 1 1 ∕ 4 inches for 1- through 1 1 ∕ 2 -inch for 1 3 ∕ 4 - through 2 1 ∕ 4 -inch pitches; 1 3 ∕ 4 inches for 2 1 ∕ 2 -inch pitch; and 2 inches for 3-inch pitch. Minimum Outside Diameters of Space Cutters for 35 teeth and over (recommended practice) are approximately as calculated from the formula: Outside Diameter 1.2 Bore Roller Diameter 0.7 Pitch 1in. = + + + ^ h Shaper Cutters: Only one will be required to cut any number of teeth for a given pitch and roller diameter. The manufacturer should be referred to for information concerning the cutter form design to be used. Sprocket Manufacture.— Cast sprockets have cut teeth, and the rim, hub face, and bore are machined. The smaller sprockets are generally cut from steel bar stock, and are fin - ished all over. Sprockets are often made from forgings or forged bars. The extent of fin - ishing depends on the particular specifications that are applicable. Many sprockets are made by welding a steel hub to a steel plate. This process produces a one-piece sprocket of desired proportions and one that can be heat treated. Sprocket Materials.— For large sprockets, cast iron is commonly used, especially in drives with large speed ratios, since the teeth of the larger sprocket are subjected to fewer chain engagements in a given time. For severe service, cast steel or steel plate is preferred.
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