JPH02280641A - Stator core for electric rotary machine - Google Patents

Abstract

PURPOSE:To reduce reactive flux and to improve efficiency without sacrifice of mechanical strength at bridge section by forming a modified composition section having high magnetic resistance at the bridge section coupling between a plurality of protrusions arranged on a stator core. CONSTITUTION:Protrusions 21 having a number corresponding to the number of piles are arranged radially on an inner ring body 20 made of thin silicon steel board having high permeability. A modified composition section 25 having high magnetic resistance is formed, through thermal treatment, at a bridge section 2 coupling the protrusions 21 at the inside thereof. When the modified composition section 25 having high magnetic resistance is formed at the bridge section 22, the modified composition section 21 restricts passage of flux induced in a coil wound around the protrusion 21 to reduce reactive flux passing through the bridge section thus increasing effective flux. By such arrangement, a highly efficient stator core for electric rotary machine can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a stator core for a generator and a motor.

[Conventional technology]

In general, electric 1N stator cores aimed at automating the winding process are constructed by dividing into an inner ring and an outer ring.After the coil is wound on the inner ring, the outer ring is connected to the inner ring. structure has been adopted.

Figure 4 shows this type of stator core, reportedly published in Japanese Patent Application Laid-open No. 58.
FIG. 3 is a divided perspective view of a stator core shown in Japanese Patent No. 33945. In the figure, αQ is an outer ring body made of a magnetic material, αη is a rigging recess formed on the inner peripheral surface of this outer ring body QO, Z is an inner ring body made of a magnetic material, and υ is formed in this inner ring body (1). The radial protrusions correspond to the number of poles of the electric motor. ) is a slit formed discontinuously in the thickness direction.

Next, the assembly of the stator configured as above 5 will be explained. First, attach the coil C (II) to the protrusion (c) of the inner ring.
(shown in FIG. 5) is wound, and then the protrusion Q) is joined to the rigging recess of the outer ring body a1 to form a stator core.

The magnetic circuit of an electric motor having a stator configured in this manner is generally as shown in FIG. ) is a driving coil wound around the sixth rotor. In this thing, the inner ring body (a)
Induced by a coil (to) wound around Nomata Kurobe
A part of the magnetic flux f1 passes through the bridge part of the inner ring body (2) to the adjacent protrusion (goods), and the remaining magnetic flux r2 crosses the air gap (a) to the rotor, and the remaining magnetic flux (r2) passes through the bridge part of the inner ring body (2) to the rotor (toward the coil of the rotor (6η) )
By passing a current through the motor, a torque is generated to rotate the rotor 6ρ, but the magnetic fluxes are ineffective magnetic fluxes that do not provide any encouragement to the rotation of the motor. Therefore, it is desirable that all of the magnetic flux f induced by the coil (2) be the effective magnetic flux. However, the bridge part (5) formed of a magnetic material is better than the air gap a, which is an air space.
Since the magnetic resistance is extremely low, a part of the magnetic flux f induced by the coil tip flows through the bridge portion (2), and the invalid magnetic flux fl tends to become large.

In order to solve this problem, in the above conventional example, the fatigue black part (
A slit (2) is provided in the bridge part between (c) to increase the magnetic resistance of the bridge part. In addition, conventionally, the air gap a is made as small as possible during processing and assembly to reduce the magnetic resistance of the air gap a, and the bridge part (b) is made as thin as possible due to processing. Efforts have been made to increase magnetic resistance and reduce reactive magnetic flux f1.

[Problem to be solved by the invention]

However, even in these conventional methods, in order to further reduce the reactive magnetic flux r1 and improve the efficiency of the motor, it is necessary to further reduce the near gap or make the bridge component thinner. Also, it is necessary to make the slit of the bridge part even larger. However, there are some difficult methods. There are limits to machining such as grinding and cutting, and the mechanical strength of the bridge component is weakened, causing the force that acts when winding the wire and when mating the inner ring body (E) and outer ring body α0 color. The acting force causes the bridge part (goods) to deform. Therefore, wL of the bridge part
Restrictions on mechanical strength have been an obstacle to improving the efficiency of electric motors.

In order to solve this problem, the present invention is designed to reduce the ineffective magnetic flux fl without weakening the mechanical strength of the bridge section that connects the protrusions on the inner side A, thereby realizing an efficient electric motor. The purpose is to obtain a stator core.

[Means to solve the problem]

The stator core of the electric motor according to the present invention is made of a magnetic material, and has multiple protrusions arranged radially, and a bridge portion connecting the inner peripheral sides between the two protrusions is made of the same magnetic material as the protrusions. , and a structurally altered part having a large magnetic resistance different from that of the protruding part is formed in this bridge part.

[Effect]

As mentioned above, in the stator core of an electric motor made with
Since it forms a fiber alteration area, the chamber allows the magnetic flux induced by the coil wound around the protrusion to pass through this tissue.
This reduces the reactive magnetic flux passing through the bridge section and provides an opening for increasing the effective magnetic flux.

〔Example〕

EMBODIMENT OF THE INVENTION Below, the stator core of the electric motor of one Example of this invention is demonstrated based on FIG. 1 and FIG. 2. In the figure, CAQ is formed by overlapping multiple thin steel plates made of high magnetic permeability magnetic material such as silicon steel in order to reduce eddy flow loss, and (b) is formed on this outer ring body α1. Sa't
(2) is an inner ring body formed by overlapping thin steel plates made of high permeability magnetic material such as silicon steel, similar to this outer ring body QO, and (2) is a radial fitting recess according to the number of poles of the motor. (2) is a magnetoresistive ear structure formed in the bridge part (B) by connecting these protrusions on the inner circumferential side. This is the altered part.

In general, in a magnetic material with high permeability such as tsuboro steel that forms the inner ring (7), its magnetic resistance is proportional to the internal strain and inversely proportional to the size of the crystal grains. - In the tissue alteration area formed in the bridge part (goods) of
has a structure with large internal strain and small crystal grains. This type of steel structure turns the steel into austenite, leaving only the austenite phase! After heating to a high temperature,
obtained by rapidly cooling and turning into martensite n,
The structure is in a state where internal strain has increased due to rapid cooling, and it becomes a very fine acicular marlansite structure, so the magnetic permeability is low and the magnetic resistance is high.

In this way, the nfci% resistance is large in the knitted altered part (
The stator core is formed by fitting the insertion convex portion (c) of the inner ring body (7) having 2) in the bridge portion (3) with the fitting recess of the outer ring body GO.

In the above stator core, the magnetic circuit when used in an electric motor is similar to that shown in the above actual mffJ.
When a current is passed through the coil (2) wound around the protruding part, a part of the magnetic flux f1 passes through the bridge area and is transferred to the adjacent protruding part p. , the remaining magnetic flux f2 crosses the air gap a and the rotor 0υ
Passing through - it leads to Kubo Kurobe Q's heart. the result,
The magnetic flux f2 is generated by the driving coil (
2) A current is caused to flow through the rotor C3 to generate torque and rotate the rotor C3.

In the stator core configured as described above, a structurally altered part (c) with high magnetic resistance is formed in the bridge area between the protruding parts, so the generated magnetic flux f is The effective magnetic flux f3 that crosses the air gap a and intersects the drive coil (9) of the rotor Qυ increases, increasing the efficiency of the magnetic circuit and increasing the efficiency of the motor. Efficiency is a good thing.

Furthermore, in this practical example, the mechanical strength between the bridge parts is increased by the quenching process of local heating and rapid cooling to form microstructures () in the structurally altered parts.

In the above example, the bridge portion (material) of the inner ring body (7) formed of a thin steel plate such as silicon steel is thermally treated to form a structurally altered portion in the bridge portion area. Next is
As shown in the third factor, a thin steel plate is subjected to thermal treatment to form a structurally altered part (c) in the bridge part (goods), and then # steel plates are stacked to form an inner ring body ■. Also, the magnetic resistance of the bridge area is large, and the same effect as in the above embodiment can be obtained.

In addition, as another embodiment of the present invention, in the conventional stator core shown in FIG.
It may be one in which an altered part (e) is formed. Even in this case, since the invalid magnetic flux f1 is further reduced, the effective magnetic flux etc. are increased, and the mechanical strength is further increased due to the hardening effect of the thermal treatment, so by forming the slit 4, It also has the effect of compensating for the poor mechanical strength of the bridge area.

In the above embodiment, the structurally altered part (a) was formed by the induction hardening method, but the method is not limited to this method, and other heat sources such as laser, electromagnetic waves, and ultrasonic waves may be used.

By using electrical heating such as resistance welding and spot welding, or by direct heating with an ultra-fine gas torch, and because the cross-sectional area of the bridge part (2) is small, a large current is passed between the multiple protrusions □□□. By locally raising the bridge portion (2) to a high temperature by self-heating the bridge portion (2) and cooling it rapidly, a structurally altered portion (c) with a large magnetic resistance can be obtained. Rapid cooling can be easily performed by air cooling or water cooling because the amount of heat input into the bridge area is small and the heat conduction from the bridge area to the protrusion area is good.

Incidentally, in the above embodiment, the case where the present invention is used in an electric motor has been described, but it goes without saying that it can also be used in other rotating electric machines.

〔Effect of the invention〕

As described above, this invention forms a structurally altered part with a large magnetic resistance different from the structural state of the projecting part in the bridge part that directly connects the projecting part of the stator core on the inner peripheral side.
It is possible to obtain a large and efficient steering core for a rotating electrical machine that can reduce the invalid magnetic flux f1 passing through the bridge part and increase the effective magnetic flux without weakening the mechanical strength of the bridge part. have an effect.

[Brief explanation of drawings]

FIG. 3 is an exploded perspective view showing a part of the inner ring body showing another embodiment of the present invention; FIG. 4 shows a stator core of a conventional rotating electric machine. The divided perspective view, FIG. 5, is a schematic diagram of the magnetic circle of the rotating electric machine. In the figure, (1) is the inner part, Q◇ is the protruding part, @ is the bridge part, and 4 is the tissue altered part. In each figure, the numeral ``-'' indicates the same or tl portion.

Claims (1)

[Claims] A plurality of protrusions arranged radially and made of a magnetic material that become part of a magnetic path, a bridge part connecting these protrusions on the inner circumferential side and made of the same magnetic material as the protrusions, and this bridge. A stator core for a rotating electrical machine, comprising a structurally altered portion formed in a portion of the protruding portion, the structure of which is different from that of the protruding portion and whose magnetic resistance is greater than that of the protruding portion.