New Industrial Yaskawa ELECTRIC AC Servo Motor 13.8A 3000RMP SGMSS-25ACA21

There are two types of servo motors to consider. The first is the classical dc servo motor and the second is the ac servo motor often referred to as a brushless dc motor. The brushless dc motor is a three phase synchronous ac motor having a position transducer inside the motor to transmit motor shaft position to the drive amplifier for the purpose of controlling current commutation in the three phases of the motor windings.
 

 

 

Another factor affecting the mechanical time constant is the temperature. Most manufacturers specify the motor parameters at 25 o C (cold rating). This implies that the magnet and wires are both at room temperature. However, the motors used in industry will operate hotter which could reach a magnet temperature of 80 o C to 90 o C in a 40 o C ambient. The winding temperature is considerably more than that. Some means must be used to compensate for the motor parameters rated at 25 o C. For those manufacturers that offer the hot rating on motor specification parameters, they should be used to calculate the time constants. The parameters of motor resistance, torque constant, and voltage constant should be adjusted, if needed, for the hot rating. The motor resistance will increase; the torque constant and voltage constant will decrease. However, contrary to their implied name both time constants are not of constant value. Rather, they are both functions of the motor’s operating temperature.