Classification and structure of linear motors
There are mainly three types of linear induction motors: flat type, cylindrical type and ring-disc type, among which the flat type is the most widely used.
The secondary side iron core of the flat linear induction motor is made of silicon steel sheets, and the side opposite to the secondary side is provided with a slot, and the winding is placed in the slot. The windings can be single-phase, two-phase, three-phase or multi-phase. There are two types of structures on the secondary side: one is a grid type structure, the iron core is slotted, and the guide bars are placed in the groove; and the end guide bars are used to connect all the guide bars in the groove; the other is a solid structure, which adopts a whole block Homogeneous metal material can be divided into non-magnetic secondary side and steel secondary side. The non-magnetic secondary side has good electrical conductivity and is generally copper or aluminum.
The mover of the linear induction motor is generally a low-carbon steel plate with copper cladding or inlaid copper strips, or a metal plate with good electrical conductivity (copper plate or aluminum plate); the cylindrical linear motor mover is mostly made of thick-walled steel pipes, which are covered with 1 up to mm thick copper or aluminum pipes.
If the mover is made of permanent magnet material, a linear synchronous motor is formed.
The secondary (rotor) of the disc type linear motor is made into a flat disc shape, which can rotate freely around the axis passing through the center of the circle: place the two primary stages on the plane near the outer edge of the disc, so that the disc is subjected to tangential force. Rotational movement. Because its operating principle and design method are the same as those of the flat-plate linear induction motor, it is still a linear motor.