CN202455175U - Stator iron core of alternating current power generator for vehicle - Google Patents

Abstract

A stator core of an alternator for a vehicle is made of a steel plate or an electromagnetic steel plate. A plurality of toothed cores protrude from the cylindrical core body to the inner rotor core side in the circumferential direction at equal intervals, and each tooth A 3-phase AC winding wire is wound on the toothed iron core, and the characteristic is that the winding wire uses a wire bundle formed into a predetermined shape in advance, and inserts the wire bundle one by one into the slot formed between each toothed iron core, and then Installed on the fixed iron core, each toothed iron core has a protrusion at the front end opposite to the movable iron core. The opening width is the circumferential width between the protrusions, which is 1.5mm to 3mm and must be greater than the diameter of the winding wire, and the thickness of the root of the protrusions of the toothed core is approximately equal to the length of the rotor core of the protrusions.

Description

Stator cores for vehicle alternators

technical field

The utility model relates to a stator iron core of an alternator for vehicles.

Background technique

Fig. 3 is a perspective view showing a stator core of a conventional vehicle alternator. Fig. 4 is an enlarged view of part P in Fig. 3 . The stator core 1 of the vehicle alternator has a substantially cylindrical shape. When assembled as a component of a vehicle alternator, a rotor, which is a rotor core not shown, is accommodated inside the cylinder. The stator core 1 has a cylindrical core body 1a, and a plurality of substantially plate-shaped tooth cores 1b are arranged at equal intervals in the circumferential direction toward the center. The end of the toothed iron core 1b faces a rotor not shown. Between the adjacent toothed iron cores 1b, slots 2 which are slots parallel to the axis are formed. When the stator core 1 is assembled as a stator, winding wires (not shown) are wound around each tooth core 1b to form a stator.

The winding wire is wound around the toothed iron core 1b. For example, in Fig. 3, the wire passes through one slot 2 from bottom to top, and then passes through the third slot 2 counted from the bottom of this slot 2 from top to bottom. , like this, at intervals of 2 slots, shuttles in each slot 2 in the axial direction. Then, winding is performed inside the core main body 1b in the circumferential direction while passing between the plurality of toothed cores 1b in this way. In the one-layer coil wound like this, the slots are staggered in the circumferential direction and the winding is three layers. Usually, the coiled wire is formed by threading the coiled wire in other places in advance, then inserts three layers into each slot 2, and then fixes it with varnish.

Each toothed iron core 1b has a protruding portion 1c at its front end facing the rotor. Both ends of the protruding portion 1c protrude, and the end faces extend in the circumferential direction. The purpose of doing this is to increase the area of the facing surface 1d opposite to the rotor. That is, the cross section of the toothed iron core 1b is formed in a T-shape, so that the area of the facing surface 1d is increased. On the other hand, the opening width S of the slot 2 formed between the tooth cores 1b is relatively narrow due to the provision of the protruding portion 1c.

The stator core 1 is manufactured using laminated steel plates in which thin iron plates or electromagnetic steel plates are laminated in the axial direction. In the process of manufacturing the stator core 1, generally, the strip-shaped iron plates formed in the cross-sectional shape of the stator core 1 are spirally rotated multiple times to form a cylindrical shape, and the two ends of the strip are welded to the end surface of the cylinder. made.

In the stator core 1 of the conventional vehicle alternator disclosed in Japanese Patent Document JP3307542A, the protruding portion 1c is made as large as possible in order to increase the area of the facing surface 1d facing the rotor. However, the reel harness must be inserted in slot 2. Therefore, at present, the protruding portion 1 c is made to protrude as much as possible while ensuring the minimum opening width S for insertion of the winding wire. The slot opening width S formed between the adjacent protrusions 1c is 33 to 37% of the pitch width t of the tooth core 1b. However, the size of the opening width S of the slot configured in this way is only for easy insertion of the coiled wire, and the output and efficiency of the generator are not taken into consideration.

Contents of the invention

The technical problem to be solved by the utility model is to provide a stator core of an alternator for a vehicle in order to overcome the above-mentioned deficiencies of the prior art. The stator core can reduce the eddy current loss of the rotor core and make the output of the generator Increase, efficiency becomes better.

The technical solution adopted by the utility model to solve the problems of the technologies described above is:

A stator core of an alternator for a vehicle is made of a steel plate or an electromagnetic steel plate. A plurality of toothed cores protrude from the cylindrical core body to the inner rotor core side in the circumferential direction at equal intervals, and each tooth A 3-phase AC winding wire is wound on the toothed iron core, and the characteristic is that the winding wire uses a wire bundle formed into a predetermined shape in advance, and inserts the wire bundle one by one into the slot formed between each toothed iron core, and then Installed on the fixed iron core, each toothed iron core has a protruding part at the front end opposite to the movable iron core. The opening width is the circumferential width between the protrusions, which is 1.5mm to 3mm and must be greater than the winding diameter, and the thickness of the root of the protrusions of the toothed core is approximately equal to the length of the rotor core of the protrusions.

The above-mentioned width is preferably 0.3 mm larger than the diameter of the winding coil, so as to ensure the performance of the product without scratching the surface of the winding coil.

The specific analysis of this technical solution is as follows: Generally speaking, when the opening becomes larger, the length of the mechanical gap between the stator and the rotor core remains unchanged, but the magnetic gap is expressed as follows.

Assuming that the mechanical gap is δ, the Carter coefficient is kc, and the magnetic gap δ' is expressed by the following formula.

δ’=kcδ

The Carter coefficient is represented by the following formula.

kc=t/(t－γδ)

γ≈(S/δ) ² /(5+S/δ)

Here, S is the opening, and t is the slot pitch. Therefore, the larger the opening S, the larger the Carter coefficient and the larger the magnetic gap δ', which degrades the output characteristics and efficiency. Therefore, in order to improve the characteristics, the opening must be reduced, but the opening must be enlarged to insert the wire harness. How to set the opening S has a great influence on the characteristics and workability of the vehicle alternator.

In addition, when the opening becomes larger, slot harmonic flux generated by the opening becomes larger, and the harmonic flux causes eddy current to flow to the surface of the rotor core, resulting in eddy current loss. The eddy current loss will increase as the opening becomes larger, so theoretically it is desirable that the opening be as small as possible, but if the opening is too small, the coil cannot be inserted through the opening, so the smallest opening is the coil Outer diameter + α (the margin for easy insertion of the coiled wire, here is 0.3mm).

Compared with the prior art, the utility model has the advantages that the output of the generator can be increased by changing the slot opening width of the side opening of the iron core, and at the same time, the eddy current loss on the surface of the rotor iron core will not be too large.

Description of drawings

Fig. 1 shows the stator core of the vehicle alternator described in the embodiment of the present invention.

Fig. 2 is a graph showing the characteristics of a vehicle alternator using a stator core according to the present invention.

FIG. 3 shows a stator core of a conventional vehicle alternator.

Fig. 4 is an enlarged view of part P in Fig. 3 .

Detailed ways

Below in conjunction with accompanying drawing embodiment the utility model is described in further detail

In FIG. 1 , the stator core 3 according to this embodiment has a cylindrical core body 3 a like a conventional stator core, and a plurality of substantially plate-shaped toothed cores 3 b facing the center and extending in the circumferential direction. Arranged at equal intervals. The end portion of the toothed iron core 3b faces a not-shown rotor. Between adjacent toothed iron cores 3b, slots 2 which are slots parallel to the axis are formed.

The front end of each toothed iron core 3b facing the rotor also has protrusions 3c protruding in the circumferential direction on both sides as in the conventional case, so that the area of the facing surface 3d facing the stator is increased. Furthermore, the root thickness 3e of the protruding portion and the length 3f of the protruding portion are set to be approximately equal so that even if the facing surface of 3d is enlarged, the magnetic flux flowing from the protruding portion 3c to the toothed core 3b can be saturated. Increasing the area towards face 3d does not diminish its effect.

In FIG. 2 , the horizontal axis represents the absolute value of the slot opening. In general, the standardized dimensions of the outer diameter of the stator of the alternator for vehicles are Φ128㎜, Φ139㎜, and Φ144㎜, and there is no problem in expressing the absolute value of the stator without changing the tendency. Here, Φ139 is taken as a representative example for explanation. The vertical axis represents the output current (A) and eddy current loss (W) under the conditions of an output voltage of 14V and a rotational speed of 6000rpm using the stator core 3 .

In the characteristics of the alternator shown in Fig. 2, the output peaks when the opening S is about 2.0mm, and then the output decreases as the opening increases, and the eddy current loss on the surface of the rotor core increases. , so the maximum opening is set to 3.0mm. Of course, the opening is preferably larger than the diameter of the coil by 0.3 mm.

In addition, when the opening is 2.0mm or less, the output will decrease as the opening of the socket becomes smaller. This is because, since the opening of the slot is reduced, the magnetic circuit around the winding wire wound on the slot, that is, the toothed core 3b on the opposite side of the core body 3a, the slot opening S The magnetic permeability will increase, and the impedance of the coil will increase, so the output will decrease. The output current is usually expressed by the following formula.

Output current I=K(Edc－Eb)/(f*L)

Here, K is a constant, Edc is the induced voltage (value converted into DC voltage) of the generator at the generator speed, and Eb is the voltage of the battery connected to the alternator (here, 14V). f is the frequency of the rotational speed, and L is the impedance of the winding wire (stator coil). Therefore, when the coil diameter plus 0.3mm is less than 1.5mm, as the slot opening shrinks, as described above, the impedance of the coil increases and the output current decreases, so the slot opening can be set to 1.5mm. mm.

Figure 2 shows the data of the stator core 3, which is the same as before, made of laminated steel plates, has 36 toothed cores, and has 12 opposing rotor poles. However, the number of laminated tooth cores 3b may not be 36, for example, it has been confirmed that there are 48, and the same characteristics are obtained even when the number of magnetic poles of the opposing rotor is 16 poles.

Claims (3)

1. A stator core of an alternator for a vehicle, which is made of a steel plate or an electromagnetic steel plate, and a plurality of toothed iron cores protrude from a cylindrical core body to an inner rotor core side in the circumferential direction at equal intervals, A 3-phase AC winding wire is wound on each toothed iron core, and the characteristic is that the winding wire uses a bundle of wires formed in advance into a predetermined shape, and inserts the bundle of wires one by one into the slots formed between the toothed iron cores , and then installed on the fixed iron core, each toothed iron core has a protruding part at the front end opposite to the movable iron core, the two ends of the protruding part protrude, the end surface extends along the circumferential direction, and the slot opens toward the rotor core side The opening width of the slot is the circumferential width between the protrusions, which is 1.5mm to 3mm and must be greater than the diameter of the winding coil, and the thickness of the root of the protrusions of the toothed core is approximately the same as the length of the rotor core of the protrusions. equal. 2. The stator core of an automotive alternator according to claim 1, wherein the width is 0.3 mm larger than the diameter of the winding wire. 3. The stator core of an automotive alternator according to claim 1 or 2, wherein the stator core has 36 toothed cores.

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