How to choose the material of DC geared motor
DC geared motors are relatively common equipment in the electromechanical industry and occupy a very important role in daily production activities. Therefore, the processing and production of the geared motor is particularly important. The reference for the selection of DC geared materials is as follows.
I. Considering the working magnetic density of the motor core
According to the characteristics of high magnetic flux density of power motor cores and low magnetic flux density of signal motor cores, the magnetic flux density of motor cores can be divided into high and low types. For iron cores with high magnetic density (generally B) (10000-15000 Gauss), silicon steel sheet or electric pure iron is selected. For silicon steel sheet, cold rolled silicon steel sheet should be preferred. It should be pointed out that, for driving low-power motors, the specifications of low-silicon and non-silicon cold-rolled steel sheets are increasing, which meets the needs of a large number of civilian electrical motors.
Second, consider the nature of the magnetic field
The magnetic field in the core circuit of the motor includes two types: constant magnetic field and rotating (alternating) magnetic field. Core: The important part of the motor that carries the magnetic flux and fixed stator windings. It consists of an iron core body stacked with silicon steel sheets, pressing fingers and end pressing plates (pressing rings), positioning ribs to prevent circumferential movement, and tightening screws. For iron cores working in a constant magnetic field, such as the main magnetic poles and chokes of DC motors, and the rotor magnetic poles of synchronous motors, electric pure iron and No. 10 steel can be selected.
Third, consider the core loss
Considering the impact of the core loss on the structure, the following two aspects should be paid attention to: 1. Selection of the thickness of the silicon steel sheet. There is much insulation between the core sheets formed by stacking thin silicon steel sheets. The iron loss is small, but the number of laminations increases, and the workload of punching and laminating increases. When thick silicon steel sheets are used, there is less insulation between the laminated core pieces and increased iron loss, but the number of laminated pieces is reduced, and the processing volume is correspondingly reduced. 2. Considering the weight of the motor core For high-power motors, DC deceleration cores are heavy, and soft magnetic materials such as silicon steel sheets with smaller unit iron loss values should be selected. For low-power motors, especially drive micromotors, the core weight is small. Relatively speaking, the unit iron loss value of the core material can be appropriately relaxed.
Fourth, consider the directionality and uniformity of cold rolling
Considering the directivity and uniformity of the magnetic permeability of the cores of various DC deceleration electric hedges, cold-rolled and hot-rolled silicon steel sheets are both oriented (anisotropic) and non-oriented (isotropic). Non-oriented silicon steel sheets are generally used. To meet the isotropic requirements of the magnetic field distribution of the motor core. Oriented silicon steel sheets are often used in transformers and large plastic DC geared motors (usually larger than 990 mm).