Working principle of linear motor Linear motor selection calculation

Working Principle of Linear Motor

A linear motor is a special type of electric motor that works similarly to a traditional rotary motor, but the force and direction of motion it produces are linear rather than rotary. The working principle of a linear motor can be simply summarized as: using the interaction of electromagnetic forces to achieve linear motion.

Linear motors usually consist of a fixed magnetic field and a conductor that can move along the direction of the magnetic field. The conductor is usually a flat thin plate or strip conductor. The interaction between the current on the conductor and the magnetic field causes the conductor to generate a force that pushes the conductor to move in a specific direction.

Specifically, when current flows through the conductor of a linear motor, a magnetic field is generated around the conductor. This magnetic field interacts with the fixed magnetic field in the motor to form a linear magnetic field gradient. This gradient causes a force to act on the conductor, thereby driving the conductor to move.

In order to enable the conductor to maintain its relative position with the fixed magnetic field, the linear motor usually installs a guide rail or magnetic guide on the conductor to prevent the conductor from deviating from the track during movement. In addition, in order to enable the conductor to maintain smooth movement, the linear motor is usually equipped with a position sensor and a speed feedback control system to accurately control the conductor.

In short, the working principle of linear motor is to use the interaction of electromagnetic force to achieve linear motion. Its special structure and working principle make it suitable for many applications that require precise position control, such as industrial automation, medical equipment, printing machines, etc.

Linear Motor Selection Calculation

The linear motor selection calculation usually includes the following steps:

Determine the required motion parameters such as load mass, load inertia, maximum velocity, acceleration, etc.

The required torque and power can be calculated based on the motion parameters using the following formula:

Power P = Fv

Torque M = F * L/2

Among them, F is the required force, v is the movement speed, and L is the movement length.

Calculate the required motor parameters based on torque and power, such as rated torque, rated speed, rated power, etc. Select a motor model that meets the requirements.

Determine the motor drive mode, you can choose DC motor drive, AC servo drive, stepper motor drive, etc.

Calculate the required power supply voltage, current and controller model according to the selected motor model and drive mode.

It should be noted that when calculating the selection of linear motors, the actual conditions of the application scenario must also be considered, such as the accuracy requirements of motion, ambient temperature, electromagnetic interference and other factors, to ensure that the selected motor can meet the actual application requirements. At the same time, it is recommended to compare and verify multiple solutions to select the optimal motor selection solution.