When selecting a DC electric motor, it is critical to identify the key performance specifications, as well as power and size requirements.
A DC motor is an electric motor that is powered by direct current (AC), and this power can come from a battery or any other DC power. Its switching (energy exchange between rotor and stator) can be through brushes (brushless) or brushless.
In a DC motor, the speed can be controlled only by varying its voltage, unlike an alternating current (AC) electric motor whose speed is varied by frequency. Axle speed specifications generally refer to the unloaded speed, which is the maximum speed the motor can reach when there is no torque applied. Shaft speed is given in revolutions or revolutions per minute (RPM). It should not be forgotten that as speed depends on voltage and power supply, if a proper specification of the DC motor is not made, it may be a limiting factor.
The torque constant is also of paramount importance. The torque of an electric DC motor is proportional to the induction current, in which case we have the torque constant.