The structural components of a linear motor
A linear motor is a type of motor structure formed by expanding a rotary motor radially. In a linear motor, the part that corresponds to the stator of the rotary motor is called the primary, and the part that corresponds to the rotor is called the secondary. Alternating current is passed through the primary, and the secondary moves linearly along the primary under the influence of electromagnetic force. In this case, the primary needs to be quite long, extending to the position required for the motion, while the secondary does not need to be as long.
Therefore, the application structure of linear motors is similar to that of rotary motors, mainly consisting of three parts: primary, secondary, and auxiliary support moving parts. Unlike the periodic motion characteristic of rotary motors, in practical applications, linear motors require different design lengths for the primary and secondary windings to ensure good electromagnetic field coupling between them throughout the motion range. The stator can be made in both short and long forms. Long stators are rarely used due to their high cost and operating expenses. Like rotary motors, the stator core of a linear motor is also made of stacked silicon steel sheets with slots on the surface; three-phase, two-phase, or single-phase windings are embedded in the slots; single-phase linear asynchronous motors can be made in a shaded-pole configuration or can be phase-shifted using capacitors.
linear motor stator
The stationary part of a DC motor during operation is called the stator, equivalent to the stator of a rotating motor, and is called the primary. The primary consists of three parts: the primary core, the primary winding, and the frame. The main function of the primary is to generate a rotating magnetic field. The primary is fixedly mounted on the casing.
linear motor rotor
The reciprocating motion in a linear motor is carried out by the rotor, also called the secondary winding. The secondary winding is supported by a guide system between two magnetic rails and is made by compressing coils together with epoxy material. The motor's secondary winding includes the coil windings, Hall element circuit board, thermostat (temperature sensor monitors temperature), and electronic interface. The secondary winding is non-steel, meaning there is no attraction force and no interference force is generated between the magnetic rails and the thrust coil. Non-steel coil assemblies have low inertia, allowing for very high acceleration. The coils are typically three-phase with brushless commutation.
In some practical applications, the secondary and primary windings of a linear motor can be interchanged; the secondary can be used as the primary, and vice versa. Different applications have different environments and requirements. Zhiwei Precision Drive has a professional technical team to provide customers with comprehensive pre-sales consultation, selection, and other services, helping each customer select the right linear motor product while saving costs.
