The construction of a system that transforms rotary motion into linear motion is taught to students in traditional mechanical engineering programs. A rotary motor, rack and pinion, belt, and pulley. And other mechanical connections, which require several components to couple and align. It can be used to convert rotational motion to linear motion. Despite the potential for effectiveness, each of these approaches has some drawbacks.
In contrast, stepper motor-based linear actuators take into account all of these considerations and have fewer problems with usage. The cause? The motor itself performs the rotary-to-linear conversion, which results in fewer components, a high force output, and improved precision.

Linear Actuator

A linear actuator is an apparatus that creates motion and force along a straight line. Stepping motors are used as the source of rotary power in stepper motor-based linear actuators. A precision lead screw replaces the shaft inside the rotor, which is now equipped with a threaded nut. Linear motion is accomplished directly through the nut and threaded screw as the rotor rotates (as in a traditional stepper motor). Directly converting from rotary to linear inside the motor makes sense since it considerably simplifies the design of rotary-to-linear applications. As a result, mechanical benefits, high resolution, and accuracy are produced, making them perfect for applications where precise motion is required.

'ONE-PHASE ON' STEP PATTERN

A simplified two-phase motor's typical step sequence. Phase A of the two-phase stator is ignited in Step 1. Because unlike poles attract, the rotor is magnetically locked in the position depicted. The rotor rotates 90 degrees clockwise when phase A is turned off and phase B is turned on. Phases B and A are switched on and off in Step 3 with the polarity from Step 1 inverted, which results in an additional 90° rotation. Phases A and B are switched on and off in Step 4, with the polarity from Step 2 reversed. The rotor rotates 90° steps in a clockwise direction when this process is repeated.

STEPPING SEQUENCE FOR "TWO-PHASE ON"

A more typical approach to Stepping is "two-phase on," meaning that the motor's two phases are constantly powered on. However, as depicted. Only one phase's polarity is changed at a time. The rotor positions itself between the "average" north and "average" south magnetic poles while the two-phase is on stepping. This approach offers 41.4% higher torque than "one-phase on" stepping since both phases are constantly on.
The lead screw is a unique screw that generates a linear force utilizing the straightforward inclined plane mechanical basis. The mechanical advantage (force amplification) is dictated by the angle of the ramp, which is a function of the lead, pitch, and screw diameter. Picture a steel shaft with an inclined plane wrapped around it. The lead is the amount a screw thread advances axially during a single revolution.

The axial separation between neighboring thread formations is known as pitch.

The quantity of separate threads on a screw form designed for manufacturing is known as the number of starts. The following equation describes the link between "lead" and "pitch," which is dependent on the "number of starts." Lead and pitch are equal for a single start thread.

Pitch = Lead x the number of starts

Depending on how steep the ramp is, the lead screw's threads enable a modest rotational force to transfer into a large load capacity (the thread lead). A small lead will deliver a high output of force and resolution. From the same source of rotational power, a greater lead will produce a lower force but a correspondingly higher linear speed.
The nut that secures the lead screw is as important as, if not more so than, the lead screw itself. This actuators layout differs from other rotary to linear approaches because the nut is frequently embedded in the rotor of the stepping motor.

Would have been better if you included diagrams