Stepper motor selection
Stepper motor selection
(OP)
Guys
Sorry to ask this stupid questions. When we size a stepper motor, we need to calculate the load inertia.
However, if I were to use bearings and my load is driven by a timing belt system, how do I go about calculating the inertia of the bearings and timing belt?
Sorry to ask this stupid questions. When we size a stepper motor, we need to calculate the load inertia.
However, if I were to use bearings and my load is driven by a timing belt system, how do I go about calculating the inertia of the bearings and timing belt?





RE: Stepper motor selection
TygerDawg
Blue Technik LLC
Virtuoso Robotics Engineering
www.bluetechnik.com
RE: Stepper motor selection
1/2*Jo*No^2=!/2*J1*N1^2
and therefore
J1=Jo*(No/N1)^2
where
Jo is the load inertia
J1 is the reflected inertia
so it shows that the load inertia is multiplied by the square of the gear ratio, No/N1, to get the reflected inert1a at motor shaft.
The bearings and belt are usually negligible for these systems; however, if you must include them, you simply add their energies to the lefthand side of the the first equation.
RE: Stepper motor selection
1/2*Jo*No^2=!/2*J1*N1^2
and therefore
J1=Jo*(No/N1)^2
where
Jo is the actual load inertia
J1 is the calculated reflected inertia
so it shows that the actual load inertia is multiplied by the square of the gear ratio, No/N1, to get the reflected inert1a at motor shaft giving the same dynamics as if the actual inertia were replaced by J1 at the motor shaft.
The bearings and belt are usually negligible for these systems; however, if you must include them, you simply add their energies to the left hand side of the the first equation written above.