On the other hand, when the motor inertia is larger than the strain inertia, the engine will need more power than is otherwise necessary for this application. This increases costs because it requires spending more for a motor that’s bigger than necessary, and because the increased power consumption requires higher operating costs. The solution is to use a gearhead to complement the inertia of the electric motor to the inertia of the strain.
Recall that inertia is a measure of an object’s level of resistance to improve in its movement and is a function of the object’s mass and shape. The higher an object’s inertia, the more torque is required to accelerate or decelerate the thing. This means that when the strain inertia is much bigger than the motor inertia, sometimes it could cause excessive overshoot or boost settling times. Both conditions can decrease production collection throughput.
Inertia Matching: Today’s servo motors are generating more torque relative to frame size. That’s because of dense copper windings, lightweight materials, and high-energy magnets. This creates higher inertial mismatches between servo motors and the loads they want to move. Using a gearhead to better match the inertia of the motor to the inertia of the strain allows for utilizing a smaller motor and results in a far more responsive system that is easier to tune. Again, this is achieved through the gearhead’s ratio, where in fact the reflected inertia of the load to the motor is decreased by 1/ratio^2.
As servo technology has evolved, with manufacturers creating smaller, yet better motors, gearheads are becoming increasingly servo gearhead essential partners in motion control. Locating the optimal pairing must take into account many engineering considerations.
So how will a gearhead go about providing the energy required by today’s more demanding applications? Well, that all goes back to the basics of gears and their ability to modify the magnitude or path of an applied drive.
The gears and number of teeth on each gear create a ratio. If a engine can generate 20 in-pounds. of torque, and a 10:1 ratio gearhead is mounted on its result, the resulting torque will be close to 200 in-pounds. With the ongoing emphasis on developing smaller sized footprints for motors and the gear that they drive, the ability to pair a smaller electric 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. Trying to perform the motor at 50 rpm may not be optimal predicated on the following;
If you are operating at a very low velocity, such as for example 50 rpm, and your motor feedback resolution is not high enough, the update rate of the electronic drive could cause a velocity ripple in the application. For example, 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 has a velocity loop of 0.125 milliseconds, it will search for that measurable count at every 0.0375 amount of shaft rotation at 50 rpm (300 deg/sec). When it does not observe that count it will speed up the engine rotation to think it is. At the quickness that it finds the next measurable count the rpm will become too fast for the application and then the drive will slower the electric motor rpm back off to 50 rpm and then the whole process starts all over again. This constant increase and decrease in rpm is exactly what will trigger velocity ripple in an application.
A servo motor operating at low rpm operates inefficiently. Eddy currents are loops of electric current that are induced within the electric motor during operation. The eddy currents actually produce a drag force within the electric motor and will have a greater negative effect on motor efficiency at lower rpms.
An off-the-shelf motor’s parameters might not be ideally suited to run at a minimal rpm. When an application runs the aforementioned motor at 50 rpm, essentially it is not using all of its obtainable rpm. Because the voltage constant (V/Krpm) of the electric motor is set for an increased rpm, the torque constant (Nm/amp), which is definitely directly linked to it-is usually lower than it requires to be. Consequently the application requirements more current to drive it than if the application had a motor specifically designed for 50 rpm.
A gearheads ratio reduces the electric motor rpm, which is why gearheads are sometimes called gear reducers. Utilizing a gearhead with a 40:1 ratio, the engine rpm at the insight of the gearhead will end up being 2,000 rpm and the rpm at the result of the gearhead will end up being 50 rpm. Operating the motor at the bigger rpm will enable you to prevent the issues 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.