| |
| Design Formula. |
(1) Speed Ratio R = rev/min of the Faster Shaft = Pitch Dia of larger pulley (D)
rev/min of the Slower Shaft Pitch Dia of small
pulley (d) |
(2) Pitch length of
belt., L = 2C +
1.57 (D+d) + (D-d)2/ 4c
(C = Center Distance) |
(3) Center Distance, C
= A+ √A2 - B (in case center distance is not specified choose C = 2 X √(D+d)
d
Where A = L/4 0.3925 (D+d)
B=(D-d)2/8 |
|
| (4) Belt
Velocity/Peripherial speed V = DN/19100m/Sec (Should not
normally exceed 30 m/Sec.) |
| |
| Selection. |
(a) Service Factor: (SF)
Consult SF table and select suitable factors. In case of speed increasing
drive, that additional factbrs as per the table |
(b) Design Power
(DP)
Multiply the normal running power (RP) with(SF). DP = RP X SF |
| (c) Selection of
belt cross section, -consult cross section table and select the belt cross
section on the basis DP and (rmp of faster shaft) (Table Graph) |
| (d) Pulley
selection -Select a suitable pulley combination which should give proper
speed ratio. (Pulley Pcd. should not be below the recommended minimum)
(Table -1) |
| (e) Basic Power
belt-Find out rated power (P) from the power rating graph |
(f) Corrected power rating (CP) = (P+ Speed Ratio
Increment) X Beltfactor (LF) X Arc of contact factor (CF). (Consult Table 2
& 3) |
| (g) Number of belt
required N=DP/CP |
|
