inertia matching servo motor to gearbox
inertia matching servo motor to gearbox
(OP)
I need to know the formula for matching a servo motor to a gearbox (planetary in this particular case) given the moments of inertia for both units. I suspect that the reduction ratio and possibly other factors will influence the outcome. Would appreciate help.





RE: inertia matching servo motor to gearbox
Ireflected = Inertia *(N1/N2)^2
Where N2 = speed of shaft to which you are refecting
N1 = speed of inertia you are relecting back
There's an old "rule of thumb" that the momemt of inertia of the load reflected back to the motor should not exceed twice the motor inertia. But what really matters is the mechanical torsional natural frequency of the complete system versus the electrical bandwidth of the servo system. So you really need the torsional stiffnesses to do it properly.
RE: inertia matching servo motor to gearbox
Inertia of the load is reduced by the square of the ratio of the gearbox.
Jreduction = Jload / ratio^2
(J = Inertia)
Must remember that your output torque does not exceed the gearbox rating, and the motor speed does not excede the input rating of the gearbox. Also take into consideration the gearbox efficiency for your sizing and the gearbox inertia.
Speed is decreaded by the ratio
Torque is increased by the ratio
Inertia is decreaded by the square of the ratio
Cameron Anderson - Sales & Applications Engineer
Aerotech, Inc. - www.aerotech.com
"Dedicated to the Science of Motion"
RE: inertia matching servo motor to gearbox
RE: inertia matching servo motor to gearbox
On high performance precision applications, matching the inertia down is more important. But like any application, the inertia matchine will depend on many factors.
Cameron Anderson - Sales & Applications Engineer
Aerotech, Inc. - www.aerotech.com
"Dedicated to the Science of Motion"
RE: inertia matching servo motor to gearbox
RE: inertia matching servo motor to gearbox
RE: inertia matching servo motor to gearbox