If the motor through reducer drive the load, the load moment of inertia is to convert to the motor shaft, namely, divided by the square of reduction ratio, and, after conversion of moment of inertia of the moment of inertia/motor = inertia ratio?
In general use ordinary ac asynchronous motor, need not calculate inertia, the characteristics of ac motor is that he didn't have enough output moment of inertia, which is driven too heavy, though the steady-state torque is enough, but the transient inertia is too large, then the motor started to be rated speed, the motor will slow fast first, slowly speed, eventually reach the rated speed, so the driver is not shivering, the control effect is not big. But due to choosing a servo motor, servo motor is depend on the encoder feedback control, so its startup is very rigid, must achieve speed and position of the target, at this time if the amount of inertia to withstand more than motor, the motor will be shaking. So when calculate with servo motor as a power source must fully consider the inertial factor, need to compute movement eventually convert to the motor shaft of inertia, through the torque, moment of inertia calculation start time M = J x B, J is the moment of inertia, B for the angular acceleration, the calculation of the torque M less than the start torque of the motor to achieve smooth start.
Yes, in the transmission shaft system, the rotational inertia of the axis of rotation is the output axis of inertia (Je) to the calculation axis reduction of the ratio squared (I squared). In other words, from the low speed axis to the high-speed axis, the high-speed axis rotational inertia (Jo) = low velocity axis rotational inertia (J1) is the reduction of the speed of the inertia (I squared). From the high speed axis to the low-speed axis, the inertia of the low speed axis (J1) = high speed axis rotational inertia (Jo) x reduction (I squared). In the calculation, the deceleration ratio is greater than or equal to 1, which is the low speed shaft tooth number/high gear number. The high-speed axis is usually the motor shaft.
This formula is a conservation of kinetic energy: the kinetic energy of the single axis is 1/2 by J times omega squared. J is the moment of inertia for the angular velocity omega, kinetic energy is conserved, the kinetic energy is equal to the kinetic energy of the low speed shaft of high-speed shaft, there are: Jo * omega squared = J1 o * 1 omega squared, then simplify equation can get inertia ratio is the square of the acceleration ratio, which is the square of the velocity ratio.
