Motor sizing for Threshing Machine.

DC Motor

• Mass of the body to hold(m)= 0.372kg

• Diameter = 2.7

• Acceleration due to gravity(g) = 9.81

• Coefficient of friction (COF) = 0.3

• F = m*g

• F = 0.372*9.81

• F = 3.658N

Now considering friction

• f=(COF)mg
• f=0.3*3.658
• f=1.09N

Now torque : f*(D/2)

• T=1.09*2.7
• T=2.96kg-cm

Now considering Factor of safety i.e., FOS=1.5

• Final Torque = T*FOS
• Final Torque=2.96*1.5
• Final Torque=4.5 The torque gets divided among 4 pully system so the Final Torque is divided by 3 Hence,
• Final Torque = 4.5/3
• Final Torque = 1.15 By comparing with the table of specification for 1.15 Kg-cm==1.2 Rated Torque ,we need DC Motor of 300RPM@1

Adapter SEIZING

• There are total 4 dc motors

• DC motor-12kg-cm torque --> Motor is of 300RPM

• Load current of the DC motor = V/R

• Voltage used for DC motor=12V

• Maximum Load current of DC motor is 300mA

• No Load current of DC motor is 60mA

• As we are using total of 4 DC motors

• So total Load current is 4*300=1200mA

• AS factor of safety is = 1.2

• Total load current is 1200*1.2=1440mA at 12V