Question

How do engineers convert the rotational motion of a stepper motor into linear motion?  Screw stepper motor

Answer 1

The rotary motion of a stepper motor can be converted into linear motion by a variety of mechanical means. These include rack and pinion, belts and pulleys, and other mechanical linkages. All of these solutions require a large number of external mechanical components.

Permanent magnet stepper motors consist of a permanent magnet rotor, coil windings and magnetic guide stator. As shown in the figure, energizing the coil windings will generate an electromagnetic field at the north and south poles. Stator magnetic field carrier, aligning the rotor with the magnetic field. By orderly excitation or "stepping" the stator coil, the magnetic field can be changed, resulting in a rotational motion.

Permanent magnet stepper motor

https://www.youtube.com/watch?v=FWkHoLFSfVI

Linear stepper motor
The rotary motion of a stepper motor can be converted into linear motion by a variety of mechanical means. These include rack and pinion, belts and pulleys, and other mechanical linkages. All of these solutions require a large number of external mechanical components.

Linear stepper motor manufacturers in China

The most efficient way is to do this conversion inside the motor itself. Linear stepper motors were first introduced in 1968. The figure below shows some typical linear stepper motors.

Linear stepper motor

The conversion from rotation to linear motion inside the linear stepper motor is done by nuts and screws. The rotor is threaded inside and the shaft is replaced by a screw. 

In order to generate linear motion, the screw must be prevented from rotating. When the rotor rotates, the internal thread engages with the screw, resulting in linear motion. 

Changing the direction of rotation reverses the direction of linear motion.

Answer 2

In industry, because of the needs of the application, it is often necessary to convert the rotational motion of the rotating motor into linear motion. The most commonly used methods are pneumatic, hydraulic, rack and pinion, timing belt, lead screw transmission and so on. 

According to the needs of different applications, such as: stroke, precision, linear thrust, mechanical efficiency, etc.  How do engineers convert the rotational motion of a stepper motor into linear motion? Screw stepper motor.

Answer 3

In the process of product design, I encountered the following problems, I hope to get your support, give advice to my brother, thank you! In this figure, axis A does rotational motion and axis B does linear reciprocating motion. 

And the power of axis B is provided by axis A, and during the movement, the reciprocating motion speed of B has a certain relationship with the speed of shaft A, that is, the higher the speed of A, the faster the reciprocating motion speed of B.

In the previous mechanism, the cam structure was adopted, that is, the shaft end of shaft A drove the cam in the cam box to rotate by connecting the timing belt, and there was a guide block moving along the parabolic trajectory on the cam body to achieve linear motion. However, the biggest drawback of this structure is that at high speed (120m/min or higher) it will cause the machine to shake left and right, and now that the frame of the machine has been finalized, it is impossible to add excess load to reduce this shaking.

If a linear motor is used, it is limited by power, because the power of the linear motor is not very high, generally in the hundreds of watts. At the same time, space size constraints must be considered. I hope that all friends will give more advice and see if there is any other good way, which is simple and not very expensive.