However, when the electric motor inertia is bigger than the load inertia, the electric motor will require more power than is otherwise necessary for this application. This improves costs since it requires spending more for a motor that’s larger than necessary, and since the increased power intake requires higher operating costs. The solution is by using a gearhead to match the inertia of the electric motor to the inertia of the load.
Recall that inertia is a measure of an object’s level of resistance to improve in its motion and is a function of the object’s mass and form. The higher an object’s inertia, the more torque is required to accelerate or decelerate the object. This implies that when the strain inertia is much bigger than the motor inertia, sometimes it can cause excessive overshoot or enhance settling times. Both conditions can decrease production collection throughput.
Inertia Matching: Today’s servo motors are producing more torque relative to frame size. That’s because of dense copper windings, light-weight materials, and high-energy magnets. This creates better inertial mismatches between servo motors and the loads they are trying to move. Using a gearhead to better match the inertia of the engine to the inertia of the strain allows for using a smaller engine and results in a more responsive system precision gearbox that’s simpler to tune. Again, this is achieved through the gearhead’s ratio, where in fact the reflected inertia of the load to the engine is decreased by 1/ratio^2.
As servo technology has evolved, with manufacturers creating smaller, yet better motors, gearheads are becoming increasingly essential companions in motion control. Finding the optimal pairing must take into account many engineering considerations.
So how really does a gearhead go about providing the power required by today’s more demanding applications? Well, that all goes back to the fundamentals of gears and their ability to alter the magnitude or direction of an applied force.
The gears and number of teeth on each gear create a ratio. If a electric motor can generate 20 in-lbs. of torque, and a 10:1 ratio gearhead is attached to its result, the resulting torque will certainly be close to 200 in-pounds. With the ongoing focus on developing smaller footprints for motors and the gear that they drive, the ability to pair a smaller motor with 
a gearhead to attain the desired torque output is invaluable.
A motor could be rated at 2,000 rpm, however your application may only require 50 rpm. Attempting to run the motor at 50 rpm may not be optimal predicated on the following;
If you are running at an extremely low rate, such as for example 50 rpm, as well as your motor feedback resolution isn’t high enough, the update rate of the electronic drive could cause a velocity ripple in the application form. For instance, with a motor feedback resolution of just one 1,000 counts/rev you have a measurable count at every 0.357 amount of shaft rotation. If the electronic drive you are using to control the motor includes a velocity loop of 0.125 milliseconds, it’ll search for that measurable count at every 0.0375 amount of shaft rotation at 50 rpm (300 deg/sec). When it does not see that count it will speed up the engine rotation to think it is. At the quickness that it finds another measurable count the rpm will end up being too fast for the application and then the drive will slower the motor rpm back down to 50 rpm and then the complete process starts yet again. This continuous increase and reduction in rpm is what will cause velocity ripple in an application.
A servo motor running at low rpm operates inefficiently. Eddy currents are loops of electric current that are induced within the electric motor during operation. The eddy currents in fact produce a drag power within the motor and will have a larger negative effect on motor functionality at lower rpms.
An off-the-shelf motor’s parameters may not be ideally suited to run at a minimal rpm. When an application runs the aforementioned motor at 50 rpm, essentially it isn’t using all of its offered rpm. Because the voltage continuous (V/Krpm) of the motor is set for an increased rpm, the torque continuous (Nm/amp), which can be directly related to it-can be lower than it needs to be. Because of this the application needs more current to drive it than if the application had a motor specifically made for 50 rpm.
A gearheads ratio reduces the electric motor rpm, which is why gearheads are sometimes called gear reducers. Using a gearhead with a 40:1 ratio, the electric motor rpm at the insight of the gearhead will be 2,000 rpm and the rpm at the output of the gearhead will end up being 50 rpm. Operating the engine at the bigger rpm will enable you to prevent the problems mentioned in bullets 1 and 2. For bullet 3, it enables the look to use much less torque and current from the engine predicated on the mechanical benefit of the gearhead.