Explanation of technical terms

Holding torque T_H [Nm]

The holding torque states the torque that the energized motor can hold at standstill without causing continuous rotation of the rotor.

Rotor moment of inertia
J [kgcm²]

Measure of the acceleration capacity of the motor. For example, at J₀ the acceleration time t_b from 0 to 3000 min^-1 can be calculated based on the following formula:

with M₀ in Nm and J in kgcm²

Winding inductance
L [mH]

Indication of the motor inductance. It is the mean value for one motor revolution, with two energized phases, at 1 kHz. Saturation of the motor must be taken into account.

Winding resistance
R [Ω]

Specification of the resistance of a motor phase, measured at 25 °C. The winding resistance indicates the electrical resistance of the motor’s coil winding

Following error
(Load-induced positional deviation)

A following error (also known as a position controller following error, following error, or tracking error) is a load-induced positional deviation caused by the load moment of inertia, resulting in a difference between the setpoint position and the actual position. The following error is caused by control-related time delays and the mass inertia of the drive, which prevent the actual position from immediately following the setpoint.