However, when the motor inertia is larger than the strain inertia, the electric motor will require more power than is otherwise necessary for the particular application. This raises costs because it requires paying more for a electric motor that’s larger than necessary, and since the increased power usage requires higher working costs. The solution is by using a precision gearbox gearhead to match the inertia of the engine to the inertia of the load.
Recall that inertia is a way of measuring an object’s resistance to improve in its motion and is a function of the object’s mass and form. The greater an object’s inertia, the more torque is needed to accelerate or decelerate the object. This means that when the strain inertia is much bigger than the motor inertia, sometimes it can cause excessive overshoot or enhance settling times. Both circumstances can decrease production line throughput.
Inertia Matching: Today’s servo motors are generating more torque in accordance with frame size. That’s due to dense copper windings, lightweight materials, and high-energy magnets. This creates higher inertial mismatches between servo motors and the loads they are trying to move. Utilizing a gearhead to raised match the inertia of the engine to the inertia of the strain allows for using a smaller motor and results in a far more responsive system that’s simpler to tune. Again, that is accomplished through the gearhead’s ratio, where the reflected inertia of the load to the engine is decreased by 1/ratio^2.
As servo technology has evolved, with manufacturers producing smaller, yet better motors, gearheads are becoming increasingly essential companions in motion control. Finding the optimum pairing must consider 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 fundamentals of gears and their ability to modify 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-pounds. of torque, and a 10:1 ratio gearhead is attached to its output, the resulting torque can be close to 200 in-pounds. With the ongoing emphasis on developing smaller sized footprints for motors and the equipment that they drive, the ability to pair a smaller motor with a gearhead to achieve the desired torque result is invaluable.
A motor may be rated at 2,000 rpm, but your application may just require 50 rpm. Trying to perform the motor at 50 rpm might not be optimal predicated on the following;
If you are working at a very low speed, such as for example 50 rpm, as well as your motor feedback quality is not high enough, the update price of the electronic drive may cause a velocity ripple in the application form. For instance, with a motor feedback resolution of just one 1,000 counts/rev you possess 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 look for that measurable count at every 0.0375 amount of shaft rotation at 50 rpm (300 deg/sec). When it does not discover that count it will speed up the electric motor rotation to find it. At the velocity that it finds the next measurable count the rpm will be too fast for the application form and then the drive will gradual the engine rpm back down to 50 rpm and then the complete process starts all over again. This constant increase and reduction in rpm is exactly 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 engine during procedure. The eddy currents actually produce a drag pressure within the electric motor and will have a greater negative impact on motor performance at lower rpms.
An off-the-shelf motor’s parameters might not be ideally suited to run at a low rpm. When an application runs the aforementioned engine at 50 rpm, essentially it isn’t using most of its obtainable rpm. As the voltage continuous (V/Krpm) of the electric motor is set for a higher rpm, the torque constant (Nm/amp), which is definitely directly linked to it-is certainly lower than it needs to be. As a result the application needs more current to operate a vehicle it than if the application had a motor specifically made for 50 rpm.
A gearheads ratio reduces the motor rpm, which is why gearheads are occasionally called gear reducers. Using a gearhead with a 40:1 ratio, the engine rpm at the insight of the gearhead will become 2,000 rpm and the rpm at the result of the gearhead will become 50 rpm. Operating the engine at the bigger rpm will allow you to avoid the worries mentioned in bullets 1 and 2. For bullet 3, it enables the look to use much less torque and current from the electric motor based on the mechanical advantage of the gearhead.