Stepper linear actuator can be divided into three types, external shaft type, non-captive shaft type and captive type.
External shaft stepper linear actuator
The structure directly uses lead screw as the motor shaft. The nut on the screw must limit rotation to achieve linear motion. This type of stepper linear actuator is usually called external shaft type stepper motor linear actuator.
Non-captive shaft stepper linear actuator
The nut is built in the motor, and the lead screw can pass through the motor to have linear motion. The screw rotation should be restricted to produce linear motion in the design. This type of motor is non-captive shaft stepper linear actuator.
Captive stepper linear actuator
The third type of motor can be used in some applications of mechanical devices in which nuts or screws are not available. This type of motor is the same as non-captive shaft actuator which has built-in nut. The screw shaft is connected with the spline shaft, and the spline and the spline housing at the front end of the motor coordinate with each other to prevent the rotation, thus realizing the linear motion of the stepper actuator. This type of motor is called captive stepper linear actuator.