Electrical engineer for the selection of step motor

 

Stepper motor can transform electrical pulse signal into angular displacement or linear displacement.In the range of the rated power of the motor speed depends only on the pulse signal frequency and pulse number of control,and not affected by load change,coupled with step motor characteristics of cumulative error is small,in areas such as speed,position with stepper motor to control becomes simpler.Stepper motor three kinds,mainly is the hybrid stepping motor is widely used.When choosing a stepper motor,must pay attention to the following parameters as the manufacturer (are supplied with the motor):Step 1) from the Angle of: after receiving a step pulse motor rotation Angle.The actual interval Angle and fine fractions of the drive.Generally the precision of the stepper motor to step away from the Angle of 3-5%,not cumulative.2) number: the inside of the motor coil set number.Step phase number is different,is apart from the different Angle.If using subdivision driver,'phase number does not make sense: change the fine fraction can change electric motor cooling fan interval Angle.3) keep the torque: also called the largest static torque.

Refers to the rated power flow speed is zero,the external force force needed for the rotor rotational torque.Keep the torque has nothing to do with the drive voltage and drive power supply,etc.Stepper motor at low speed torque close to holding torque.As a result of the stepper motor output torque and power increases with the speed and constantly changing,so keep the torque is measured step motor is one of the most important parameters.Although holding torque is proportional to the electromagnetic excitation ampere turn,with the air gap between the rotor teeth.But too much by reducing the air gap,increasing the excitation ampere turns to improve static moment is not desirable,it will cause heating of the motor and the mechanical noise.Keep the torque type determined as follows: Stepper motor dynamic torque a while it is difficult to determine,tend to make sure the static torque of motor.Static moment of choice was based on motor work load,the load can be divided into two kinds of inertia load and friction load.Single inertial load,and there is no single friction load.Order more (generally by low speed) when (suddenly) starting when the two kinds of load are to consider,when accelerating (slopes) starting main consideration of inertia load,constant speed run into as long as considering the friction load.In general,keep the friction load torque should be within diesel generating set 2 to 3 times as well,holding torque once selected,motor frame and length can be set down.