CN105262246A - Long strip-shaped silicon steel punching sheet of brushless DC motor and stator comprising same - Google Patents

Abstract

The invention relates to a long strip-shaped silicon steel punching sheet of a brushless DC motor and a stator core comprising the same. The long strip-shaped silicon steel punching sheet is in the shape of a long strip, and is divided into a plurality of punching sheet units. Each punching sheet unit comprises a stator outer ring portion, a stator winding bracket and a stator yoke. The stator outer ring portions of the punching sheet units are mutually connected into an integral whole. One end of the integrally connected stator outer ring portions is provided with a connecting male tenon, and the other end is provided with a connecting female tenon. Each punching sheet unit is provided with a lamination connecting hole. The stator core is formed by laminating the long strip-shaped silicon steel punching sheet, the laminated long strip-shaped silicon steel punching sheet is bent into a circle and fixed through insulating pins inserted into the lamination connecting holes. Two ends of the long strip-shaped silicon steel punching sheet are connected through buckling the connecting male tenon and the connecting female tenon. The beneficial effects are that a lot of materials can be saved, the eddy current loss is reduced, the efficiency of the brushless DC motor is improved, electricity of an electric vehicle is enabled to be saved by 20%, enterprises are helped to create high-efficiency motor brands, and higher income is acquired.

Description

Long silicon steel punching sheet of brushless DC motor and the stator core formed by it

technical field

The invention relates to the technical field of brushless DC motors, in particular to a strip-shaped silicon steel punching sheet of a brushless DC motor and a stator iron core formed therefrom.

Background technique

Electric vehicles are driven by electricity and have been widely used in the past ten years. In the process of electric vehicles replacing bicycles, improving the efficiency of brushless DC motors has been the goal that has been pursued. Although the driving torque of the brush motor is large, it is quite troublesome to replace the brush due to the friction between the brush and the stator and the rotor. In addition, if the brush does not touch suddenly, an electric spark will be generated. Both use brushless DC motors. For brushless DC motors, since the rotor rotates in the magnetic field, a vortex electric field is generated, forming eddy currents, causing the rotor and stator to heat up, which reduces the efficiency of the brushless DC motor. In the prior art, silicon steel sheets are generally laminated. to reduce eddy currents. And the thinner the silicon steel sheet, the higher the efficiency of the motor. Therefore, the efficiency of the motor made of silicon steel sheets with small labels is higher. In addition, there are many factors that affect the efficiency of DC motors, such as mechanical rotation wear and the rotation of air to form wind during rotation, which will reduce the efficiency of the motor. Therefore, the air gap between the stator and the rotor may be as small as possible, and the shaft is required to be strong. There is no eccentricity, and the adjacent parts of the rotor of the stator are concentric arcs; the stator is composed of several groups of copper core coils. Due to the resistance of the copper wires, Joule heat will be generated after electrification. This Joule heat is proportional to the applied voltage and inversely proportional to The resistance value of the coil, so in order to improve the electrode efficiency, on the one hand, the method of reducing the voltage value applied to the coil is adopted, and on the other hand, the method of using thicker copper wires is used to reduce Joule heat; the iron loss of the rotor and the stator is also A problem that cannot be ignored, since the stator is composed of several groups of coils to reduce the voltage value on each coil, but the magnetic field polarity of the two adjacent coils is opposite, and the magnetic field changes in a gradient at the place where the coils are adjacent to the rotor. When the rotor cuts When the magnetic field lines in this area, a changing induced electromotive force is generated, which forms an induced current in the rotor, and can excite the magnetic field, causing eddy currents to be generated in the silicon steel sheet in the stator. Therefore, the stator silicon steel sheets are also laminated to reduce eddy currents; and if the casing is made of steel, it will also cause casing loss, so plastics with high heat capacity are used to absorb part of the Joule heat generated by the rotor and stator.

Contents of the invention

The technical problem to be solved by the present invention is to provide a long strip silicon steel punching sheet of a brushless DC motor and the stator core formed therefrom, so as to improve the efficiency of the motor.

The technical solution adopted by the present invention to solve the technical problem is: a strip-shaped silicon steel punching sheet for a brushless DC motor, which is in the shape of a strip and is divided into multiple groups of punching units, each group of punching units includes a stator The outer ring part, the stator winding frame and the stator yoke, the stator yoke is connected to the top of the stator winding frame, the stator outer ring part is connected to the root of the stator winding frame, the stator outer ring parts of the punching unit are connected to each other as a whole, and Between the stator outer rings of adjacent punching units, a connecting gap is provided to facilitate bending of the elongated silicon steel punching. One end of the stator outer ring connected as a whole has a connecting tenon, and the other end has a connecting female tenon. There are lamination connection holes on the punching unit.

It is further defined that the lamination connection hole is located at the root of the stator bobbin, and the distance between the lamination connection hole and the three outer edges of the punching unit adjacent to it is equal.

Further defined, the connection gap is a V-shaped connection gap.

A stator core of a brushless DC motor, which is formed by lamination of long strip silicon steel punches, after lamination, the long strip silicon steel punches are bent into a circle and passed through the insulating pins inserted into the lamination connection holes Fixed, the two ends of the elongated silicon steel punching sheet are fastened and connected by connecting the male tenon and the connecting female tenon.

The beneficial effects of the invention are: it can save a lot of materials, reduce the eddy current loss, improve the efficiency of the brushless DC motor, so that the electric vehicle can save 20% of electricity, and help enterprises to create high-efficiency motor brands and obtain higher profits.

Description of drawings

Fig. 1 is the top view state schematic diagram of elongated silicon steel sheet of the present invention;

Fig. 2 is the side view state schematic diagram of strip shape silicon steel sheet of the present invention;

Fig. 3 is the schematic structural view of the bending forming of the elongated silicon steel sheet of the present invention;

Fig. 4 is the schematic structural view of the punching unit of the elongated silicon steel punching sheet of the present invention;

In the figure, 1. Stator yoke, 2. Stator winding frame, 3. Connecting female tenon, 4. Laminated connecting hole, 5. Connecting gap, 6. Connecting male tenon, 7. Insulating pin, 8. Stator outer ring department.

detailed description

As shown in Figures 1, 2 and 4, a strip-shaped silicon steel punching sheet for a brushless DC motor is in the shape of a strip and is divided into multiple groups of punching units, each group of punching units includes the outer ring of the stator 8. The stator winding frame 2 and the stator yoke 1, the stator yoke 1 is connected to the top of the stator winding frame 2, the stator outer ring part 8 is connected to the root of the stator winding frame 2, and the stator outer ring parts 8 of the punching unit are connected to each other It is connected as a whole, and a connection gap 5 is provided between the stator outer ring parts 8 of adjacent punching units to facilitate bending the elongated silicon steel punching sheet, and there is a connecting tenon at one end of the integrated stator outer ring part 8 6. There is a connecting tenon 3 at the other end, and a lamination connecting hole 4 on the punching unit.

As shown in Figure 3, the stator core of a brushless DC motor is formed by laminating long silicon steel punches. The laminated long silicon steel punches are bent into a circle and inserted into the stack The insulating pin 7 of the connecting hole 4 is fixed, and the two ends of the strip-shaped silicon steel punching sheet are fastened and connected by connecting the male tenon 6 and the connecting female tenon 3. When the connecting male tenon 6 is inserted into the connecting female tenon 3, external force is needed.

When designing the strip-shaped silicon steel sheet and the stator core of the brushless DC motor, the principle of lamination of the silicon steel sheet of the brushless DC motor is followed; the principle of the minimum air gap between the rotor and the stator; the winding frame The principle of minimum metal block size; the principle of minimum eddy current loss.

The circular arc of the stator yoke 1 of the elongated silicon steel punching sheet of the brushless DC motor and the rotor are concentric circles.

The width of the stator yoke 1 should be as wide as possible, because after bending the elongated silicon steel sheet, the gap between the stator yoke 1 will also reduce the working efficiency of the motor. The gap can be as large as possible without affecting the winding enameled wire. Small to ensure maximum work efficiency.

The stator winding frame 2 is as thin as possible to prevent large eddy currents, because the magnetic field polarities of the two adjacent coils are opposite, and the magnetic field changes in a gradient at the place where the coil and the rotor are adjacent to each other. When the rotor cuts the magnetic field lines in this area, a change occurs The induced electromotive force, the induced electromotive force forms an induced current in the rotor, and can excite the magnetic field, causing eddy currents to be generated in the silicon steel sheet in the stator. The voltage will increase or decrease instantaneously, which will generate a self-induced electromotive force to the coil, form an eddy current, and cause heat.

The lamination connection hole 4 is located at the root of the stator winding frame 2, and the distance between the lamination connection hole 4 and the three outer edges of the punching unit adjacent to it is equal. The lamination connection hole 4 should be as large as possible under the premise of ensuring the strength of the elongated silicon steel punched part, so as to reduce the eddy current to the greatest extent.

The connection gap 5 is a V-shaped connection gap, and the connection gap 5 mainly ensures that the bobbin 2 can be bent into a circle.

The stator silicon steel ring is bent by using the long silicon steel punching sheet, which saves a lot of material and reduces the eddy current loss compared with the direct punching of the entire stator silicon steel ring.

Example:

As shown in Figure 4, the strip-shaped silicon steel punching sheet consists of 18 groups of punching units, each group is equivalent to a sector with a central angle of 20 degrees, and each stator winding frame 2 is 17.4 units long and 26 units wide. A circle with a diameter of 5 units is dug out in the winding frame 2 to form a laminated connection hole 4 for inserting an insulating pin 7; units, the inner arc diameter is 48 units of the stator silicon steel ring. Each unit is 0.8mm.

Claims (4)

1. the strip silicon steel punching of a brshless DC motor, it is characterized in that: elongated, and be divided into and organize punching sheet unit more, each group punching sheet unit all comprises stator outer ring portion (8), stator winding frame (2) and stator yoke (1), stator yoke (1) is connected with the top of stator winding frame (2), stator outer ring portion (8) is connected with the root of stator winding frame (2), the stator outer ring portion (8) of punching sheet unit is connected to each other and is integrated, and the connection gap (5) being convenient to this strip silicon steel punching bending is set between the stator outer ring portion (8) of adjacent punching sheet unit, have in the one end in the stator outer ring portion (8) connected as one and connect public tenon (6), the other end has the female tenon of connection (3), punching sheet unit has lamination connecting hole (4).

2. the strip silicon steel punching of brshless DC motor according to claim 1, it is characterized in that: described lamination connecting hole (4) is positioned at the root of stator winding frame (2), and three outward flanges of lamination connecting hole (4) and punching sheet unit adjacent thereto are apart from equal.

3. the strip silicon steel punching of brshless DC motor according to claim 1, is characterized in that: described connection gap (5) is V-shaped connection gap.

4. the stator core of a brshless DC motor, it is characterized in that: formed by the strip silicon steel punching lamination described in claim 1 or 2 or 3, strip silicon steel punching after lamination bends to circle, and fixed by the insulation pin (7) of filling in lamination connecting hole (4), the two ends of strip silicon steel punching are by connecting male tenon (6) and being connected female tenon (3) and being fastened and connected.