## Inertia matching question

## Inertia matching question

(OP)

I need a little help understanding the logic of the statement below.

## Quote:

The secret to the extra boost of inertia is its special inertia flywheel, which adds from three to 10 times the inertia of a standard servo motor. This flywheel replaces the more expensive gearbox traditionally added to the motor for applications where the customer has a high load-to-rotor inertia mismatch. Now, on applications where customers would normally add a gearhead, they can simply use a motor, saving money and eliminating the speed constraints normally associated with a gearhead.

## RE: Inertia matching question

1) Use a gearbox as an "inertia translator" for the load. For a speed reduction gearbox, the reflected inertia is equal to the gear ratio squared times the load inertia (plus some added inertia from the gears).

2) Use a flywheel to add inertia to the motor.

## RE: Inertia matching question

The real question should be do the inertias have to be matched? If not then why add inertia to the motor?

Peter Nachtwey

Delta Computer Systems

http://www.deltamotion.com

## RE: Inertia matching question

That is what I thought, here is the link to the advertisement:

http:

I agree. .

## RE: Inertia matching question

Adding gear box is one thing, motor interia is another.

For fast servo - never do this (add interia).

For spinning with one dirrection and with one speed - yes , adding interia makes system smoother.

It also minimizes torque ripple cause by commutation in 6-step drives.

Stability - now can play with poles and zeros inside DSP driving this motor.