Calculating Roller Chain Strength Proportions

Power to transmit

 

Chain speed

 

Effective chain pull or tensile load

 

Centrifugal force

 

F c = m v 2

Maximum tension in taught chain span

 

F Tmax = F p + F C

Speed for each driven sprocket or idler

 

Power transmitted by each driven sprocket (for idlers P X = 0 and therefore P i = 0)

 

P i = P P X η

Torque what acts on each driven sprocket (for idlers T i = 0)

 

Forces at the tight and slack side of each sprocket are determined. The program defines force on input F 1 and force on output F 2 for each sprocket. These forces are defined with respect to the chain motion. Force on input F 1 is the force in chain span where the chain gets into contact with the given sprocket. Force on output F 2 is the force in chain span where the chain leaves the given sprocket.

Force in chain span at the tight side of the driver sprocket

 

F 1 = F Tmax

Force in chain span at the slack side of the driver sprocket

 

F 2 = F 1 - F p

Force in chain span at the tight side of each driven sprocket

Force in chain span at the tight side of each driven sprocket is consumed from force where chain gets into contact with logically next sprocket with respect to the chain motion direction.

 

F 2 = F 1(i+1)

Force in chain span at slack side of each driven sprocket

 

F 1 = F 2 - F p P X

Resultant axle load for each sprocket

 

where:

 

P

Power [W]

 

T

Torque [Nm]

 

n

Speed of the sprocket [rpm]

 

n 1

Speed of the driver sprocket [rpm]

 

n i

Speed of the driven sprocket or idler [rpm]

 

i

Transmission ratio for driven sprocket or idler [-]

 

v

Chain speed [m/s]

 

D P

Pitch diameter of the sprocket [m]

 

F P

Effective chain pull or tensile load [N]

 

F C

Centrifugal force [N]

 

m

Specific chain mass [kg/m]

 

F Tmax

Maximum tension in taught chain span [N]

 

P i

Power transmitted by driven sprocket [W]

 

P X

Power ratio factor of driven sprocket [-]

  η

Efficiency [-]

 

T i

Torque what acts on driven sprocket [Nm]

 

F 1

Force in the chain span where individual sprocket gets into contact with the chain [N]

 

F 2

Force in the chain span where individual sprocket leaves the chain [N]

 

F 1(i+1)

Force in the chain span where logically next sprocket gets into contact with the chain [N]

 

F R

Resultant axle load of each sprocket [N]

  β

Contact angle of each sprocket [deg]