Chain Drive (Roller Chain) - Design procedure Step 1: Type of chain Step 2: Preferred transmission ratio, i [PSG Page 7.74]. Step 3: Number of teeth, Z1 & Z2 [PSG Page 7.74]. Step 4: Standard pitch, p
[Standard values are 9.525 mm, 12.7 mm and 15.875 mm - PSG Page 7.74] Optimum centre distance, a = (30 to 50) p. 50) p. (‘a’ and ‘p’ are in mm) [PSG Page 7.74]. 7.74]. (If‘a’ value is not given, it can be assumed between 500 mm to 1000 mm). Step 5: Selection of chain [PSG Page 7.71 to 7.73]. Step 6: check for actual factor of safety, [n] [PSG Page 7.78].
1. Actual load ∑ P a) Tangential force Pt [PSG Page 7.78]. i. Power [N in KW] ii. Velocity (v) =
zpN 60
in m/sec
b) Centrifugal tension P c [PSG Page 7.78]. i. w = mg c) Tension due to sagging P s [PSG Page 7.78]. 2. Service factor K s [PSG Page 7.76 & 7.77]. Working load = ∑ P x K s 3. Breaking load Q [PSG Page 7.71 to 7.73] Step 7: Check for actual factor of safety, [n]
If the calculated actual factor of safety, [n] [PSG Page 7.78]. Minimum factor of safety, n [PSG Page 7.77]. If the calculated actual factor of safety, [n] > minimum factor of safety, ‘n’ then, the design is Safe. Step 8: Actual Bearing Stress, σ [PSG Page 7.77].
Rearrange the formula in PSG Page 7.77 and compute the bearing stress, a. The bearing area, A of the selected chain is obtained from PSG Page 7.71 to 7.73. Step 9: Check for allowable bearing stress [PSG Page 7.77].
From the table in PSG page 7.77, find the allowable bearing stress based on pitch and speed of rotation of small sprocket. If the calculated actual bearing stress < allowable bearing stress then, the design is safe. ). [PSG Page 7.75]. Step 10: Actual length of chain ( l ). Step 11: Exact centre distance, a [PSG Page 7.75]. Step 12: Pitch diameters of the sprockets, d1 & d2 [PSG Page 7.78].
Chain Drive (Roller Chain) - Design procedure Step 1: Type of chain Step 2: Preferred transmission ratio, i [PSG Page 7.74]. Step 3: Number of teeth, Z1 & Z2 [PSG Page 7.74]. Step 4: Standard pitch, p
[Standard values are 9.525 mm, 12.7 mm and 15.875 mm - PSG Page 7.74] Optimum centre distance, a = (30 to 50) p. (‘a’ and ‘p’ are in mm) [PSG Page 7.74]. (If‘a’ value is not given, it can be assumed between 500 mm to 1000 mm). Step 5: Selection of chain [PSG Page 7.71 to 7.73]. Step 6: check for actual factor of safety, [n] [PSG Page 7.78].
4. Actual load ∑ P d) Tangential force Pt [PSG Page 7.78]. i. Power [N in KW] ii. Velocity (v) =
zpN 60
in m/sec
e) Centrifugal tension Pc [PSG Page 7.78]. i. w = mg f) Tension due to sagging P s [PSG Page 7.78]. 5. Service factor K s [PSG Page 7.76 & 7.77]. Working load = ∑ P x K s 6. Breaking load Q [PSG Page 7.71 to 7.73] Step 7: Check for actual factor of safety, [n]
If the calculated actual factor of safety, [n] [PSG Page 7.78]. Minimum factor of safety, n [PSG Page 7.77]. If the calculated actual factor of safety, [n] > minimum factor of safety, ‘n’ then, the design is Safe. Step 8: Actual Bearing Stress, σ [PSG Page 7.77].
Rearrange the formula in PSG Page 7.77 and compute the bearing stress, a. The bearing area, A of the selected chain is obtained from PSG Page 7.71 to 7.73. Step 9: Check for allowable bearing stress [PSG Page 7.77].
From the table in PSG page 7.77, find the allowable bearing stress based on pitch and speed of rotation of small sprocket. If the calculated actual bearing stress < allowable bearing stress then, the design is safe. Step 10: Actual length of chain ( l ). [PSG Page 7.75]. Step 11: Exact centre distance, a [PSG Page 7.75]. Step 12: Pitch diameters of the sprockets, d1 & d2 [PSG Page 7.78].
