Torque and transmission power

M_m = .

Running moment required to shift load in axial direction (lead screw).

F_a      

axial load (N)

P_h        

screw pitch (mm)

h_d      

direct efficiency

M_f = 

Braking torque needed to oppose rotation of the screw produced by an axial load (lead screw).

F_a    

axial load (N)

P_h

screw pitch (mm)

h_i

indirect efficiency (Nm)

W

Required motor transmission power

where:

it follows:

M_m 

running moment (Nm)

n

working motor speed (RPM)

w

angular motor acceleration (rad/s² )