TIMING PULLEY CALCULATION CHART

Hello Everyone.....!!!

Today we shall continue our previous 'TIMING PULLEY ' series. Here we are going to discuss timing pulley calculation chart.   





                            

Pitch Diameter (P.D.) = (Pitch x Number of teeth) / ∏

Timing belt pulley outside diameter (O.D.) builds upon the relationship between the timing belt pulley and timing belt. The outside diameter of the timing belt pulley is in contact with the tooth bottom of the timing belt while meshing with it. The distance from the timing belt tooth bottom to the tensile cord (pitch line) will determine the outside diameter of the timing belt pulley for any timing belt pitch/timing belt profile.


Variables:

Pitch :                                5 mm
No of Teeth:             X     16
                                         80 mm
                                     
           80mm          =1.003 inches
         ∏(3.14)      

Hence Pitch Diameter =  1.003 inches



Outside Diameter (O.D.) = Pitch Diameter – (2 x U) 
Note: “U” = distance between the tensile cord and the bottom of the belt tooth 

Rule of Thumb

To quickly calculate the outside diameter (O.D.) in inches of any 8mm pitch timing belt pulley divide the number of teeth on the pulley by ten (10). For example an 80 tooth pulley would have an 8” outside diameter (80 teeth / 10) or a 33 tooth pulley would have a 3.3” outside diameter (33 teeth / 10).

Variables : 


Pitch :                                5 mm
No of Teeth:             X     16
                                         80 mm
                                     
           80mm          =1.003 inches
         ∏(3.14)      

Distance between the tensile cord and the bottom of the belt tooth = 0.0225
2 X 0.0225 = 0.0450 

P.D- 2U = 1.003-0.0450 
    Outside Diameter     =     0.958 inches



Thank you.....