JPH07111746A - Rotating electric machine - Google Patents

Abstract

(57) [Summary] [Purpose] To obtain a lightweight and small rotating electrical machine such as a general-purpose induction motor. [Structure] A housing 1 having a thick portion 1b formed on its inner peripheral portion is made of a magnetic aluminum alloy material, and the outer peripheral portion of a stator core 2 is mounted on the inner peripheral portion of the thick portion 1b. The thick portion 1b is used as a part of the magnetic path. [Effect] A part of the stator core 2 is replaced by the thick portion 1b made of a magnetic aluminum alloy material, and the magnetic aluminum alloy material has a low specific gravity and a high heat conduction characteristic, which results in weight reduction and improvement of heat dissipation characteristics. Miniaturization can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary electric machine provided with an aluminum housing, and more particularly to a rotary electric machine suitable for an induction motor having a relatively small capacity.

[0002]

2. Description of the Related Art A rotary electric machine such as a general-purpose induction motor having a relatively small capacity is required to be small in size, light in weight and low in cost. To meet such requirements, the induction machine having the structure shown in FIG. Electric motors have been widely used from the past.

In FIG. 7, 1 is a housing, 1a
Is a radiation fin, 2 is a stator (armature) iron core, 3 is a stator
(Armor) Coil, 4a, 4b are end brackets, 5 is a shaft (rotating shaft), 6 is a rotor, 7 is an end ring, 8
Is an internal fan (internal cooling fan), 9 is an external fan (external cooling fan), 10 is an end cover, and 10a is an air hole.

The housing 1, which is also called a frame, is formed into a cylindrical shape by casting an iron-based material and constitutes an outer cover of a rotary electric machine. The radiating fins 1a have a function of increasing a radiating area and promoting cooling, and a large number of radiating fins 1a are radially formed on the outer periphery of the housing 1.
It is cast integrally with.

The stator iron core 2 is a laminated iron core made of a laminated body of silicon steel sheets, and the inner peripheral portion of the laminated iron core is provided with a plurality of slots, and the stator coil 3 is wound around the slots. Thus, the stator of the rotating electric machine is configured. The end brackets 4a and 4b have fitting portions, and are thereby attached to the fitting portions at both ends of the housing 1 with bolts or the like. The shaft 5 includes the end brackets 4a and 4b.
Is supported by a bearing provided at the one end thereof, one end side of which is inserted through the end bracket 4b to form an output shaft, and an outer fan 9 is attached to the other end side through which the end bracket 4a is inserted.

[0006] The rotor 6 is provided at an intermediate position in the housing 1 of the shaft 5 and at a position facing the stator 2. The rotor 6 is provided with an end ring 7, and A secondary conductor bar not shown is provided.

The inner fan 8 is an end ring 7 of the rotor 6.
It is composed of a plurality of blade blades provided on both end surfaces of the electric motor so as to project in the axial direction, and functions to circulate the air inside the electric motor to promote cooling.

The outer fan 9 is arranged in the end cover 10. The end cover 10 covers the outside of the outer fan 9 to the outer diameter portion of the end bracket 4a or the vicinity of the outer peripheral portion of the housing 1. Is provided. The end portion is formed into an open cylindrical shape or a deformed cylindrical shape, and a radial gap is formed between the end bracket 4a and the outer diameter portion of the housing 1, thereby forming a ventilation path. There is. Further, at the outer end of the end cover 10, a plurality of air holes 10a for taking in outside air by the external fan 9 are provided.

Inside the electric motor, the opening portions at both ends of the housing 1 are thus closed by the end brackets 4a and 4b, but when the rotor 6 is rotated, the inner fan 8 and the outer fan 9 are also rotated. As a result of the rotation, the outside air is ventilated from the air holes 10a of the end cover 10 to the outer surfaces of the end bracket 4a, the housing 1, the heat radiation fins 1a and the end bracket 4b as shown by the arrow (a), and the heat is released. You can get it.

On the other hand, inside the electric motor, as described above,
Air is circulated by the inner fan 8, so that the air passes through the rotor 6, the end ring 7, the stator coil 3 and both end surfaces of the stator 2 while being cooled, and then is comparatively discharged as compared with the housing 1. End bracket 4 with low temperature rise
The structure is such that the heat passes through the inner surfaces of a and 4b and the heat is dissipated at this time.

Here, the housing 1 constitutes a member for holding the stator of the rotating electric machine and protecting the inside thereof, and together with this, as described above, during operation of the rotating electric machine,
The heat generated from the stator etc. is guided to the outside and the heat radiation fin 1
Together with a, it also functions to dissipate this heat into the air and suppress the temperature rise. Therefore, it is desirable that its material has good heat conduction, and in terms of weight reduction, its specific gravity is small. Is desirable. Therefore, from this viewpoint, in recent years, rotary electric machines such as induction motors using aluminum (aluminum) as the material of the housing have been provided to the market.

[0012]

It cannot be said that the above-mentioned prior art has sufficiently taken into consideration the advantages of using aluminum as the material of the housing, and there is a problem in terms of promoting the weight reduction of the rotating electric machine. It was An object of the present invention is to provide a rotating electric machine in which the advantages of using an aluminum housing are maximized and a sufficient weight reduction is obtained.

[0013]

[Means for Solving the Problems] The above object is to provide a stator iron core of a rotary electric machine having a cylindrical portion on which an inner peripheral slot is formed and a cylindrical portion forming an outer peripheral magnetic path. By dividing the outer peripheral side cylindrical portion with a cylindrical portion made of a magnetic aluminum alloy material, and forming the cylindrical portion made of this magnetic aluminum alloy material integrally with the housing of the rotating electric machine. To be achieved.

[0014]

[Function] The cylindrical portion made of the magnetic aluminum alloy material integrally formed with the housing constitutes the magnetic path of the stator iron core, thereby reducing the amount of the iron core made of the laminated body of silicon steel sheets. work. Here, since the specific gravity of the magnetic aluminum alloy material is considerably smaller than the specific gravity of the silicon steel sheet, sufficient weight reduction can be obtained.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A rotary electric machine according to the present invention will be described below in detail with reference to the illustrated embodiments. FIG. 1 shows an embodiment in which a rotating electric machine according to the present invention is applied to an induction motor. It is the same as the conventional example described in FIG. 7 except that the structure of the child iron core 2 is different.

The housing 1 is made of a magnetic aluminum alloy material marketed under the trade name of "magnetic aluminum alloy", and has a thick portion 1b formed in a portion corresponding to the outer peripheral portion of the stator core 2. There is. And, in response,
As shown in FIG. 2, the stator core 2 is formed in a shape formed only by a cylindrical portion 20 having an inner peripheral slot 2a and a tooth portion (teeth portion) 2b. The cylindrical portion forming the passage is divided to be formed by the thick portion 1b of the housing 1.

The "magnetic aluminum alloy" (trade name) that constitutes the housing 1 is a mixture of aluminum powder and a ferromagnetic material.
It is a new material produced by solidification molding, which is a non-magnetic material such as aluminum that has strong magnetic properties and high rigidity, and has magnetic anisotropy by devising the manufacturing method. It is also a material that can be applied. And the characteristics of this material are high rigidity (about twice as much as aluminum), high heat resistance, and high abrasion resistance, while retaining the basic property of aluminum that is lightweight (30 to 50% lighter than iron). It also has a high electromagnetic wave shielding property, and it is possible to select the magnetic properties by the solidification molding method, and it is also possible to obtain complicated part shapes by cold forging.

The stator core 2 will be described in more detail. In FIG. 2, the stator core 2 in this embodiment has a plurality of slots 2a between the outer peripheral portion and the inner peripheral portion as described above. These slots 2a are open on the outer peripheral side end, and are not opened on the inner peripheral side end, and are located slightly outside the inner peripheral surface, leaving a connecting portion indicated by 2g. As a result, the slot 2a is
It is closed on the inner peripheral side, and therefore the stator coil 3
Is inserted into the slot 2a from the outer peripheral side and wound.

Therefore, first, the stator coil 3 is wound around the slots 2a from the outer peripheral side through the insulator 3a, and then the sikiki (coil The wedges 3b for restraint are attached, and the winding of the stator coil 3 is completed.

Thereafter, the stator core 2 (cylindrical portion 20) in which the stator coil 3 is housed in the slot 2a is varnished for strengthening the insulation, and then the housing 1
After being inserted inside and positioned on the inner circumference of the thick portion 1b, it is mounted on the housing 1 by shrink fitting. Therefore, the inner diameter of the thick portion 1b of the housing 1 is smaller than the outer dimension of the stator core 2 (cylindrical portion 20) in advance by the amount of the interference, so that the fixing A predetermined tightening force is applied to the attachment of the child iron core 2.

Thereafter, the rotor 6 is inserted into the stator core 2 and the end brackets 4a and 4b are attached to the housing 1 to complete the induction motor shown in FIG.

Next, the structure of the magnetic circuit in this embodiment will be described. As is clear from the above description, in this embodiment, as a result, the original stator core constitutes the cylindrical portion 20 in which the slot on the inner peripheral side is formed and the magnetic path on the outer peripheral side. It is divided into a cylindrical portion, and the outer peripheral cylindrical portion is formed by the cylindrical thick portion 1b of the housing 1 made of a magnetic aluminum alloy material.

Therefore, the main magnetic flux generated by the stator coil 3 is
As shown by the arrow (b) in FIG. 2, after passing through the tooth portion 2 b forming a certain magnetic pole of the stator 2, the thick portion 1 of the housing 1
b, passing through the adjacent tooth portion 2b ′ forming the next magnetic pole, and forming a closed circuit toward the rotor (not shown), and thus, also in this embodiment, the necessary stator magnetic path is formed. It is possible to obtain an induction motor having necessary characteristics.

The thick portion 1b of the housing 1 corresponds to the outer peripheral portion of the stator core 2, and this portion is indicated by 1c in FIG.
It is indicated by. Since the portion 1c forming a part of this magnetic path is an alloy of aluminum and a magnetic substance, it has a small saturation magnetic flux density, unlike a perfect magnetic substance such as a silicon steel plate. Therefore, the magnetic flux density of this portion, which corresponds to the tooth portion of the stator, must be made smaller than in the prior art. However, according to this embodiment of the present invention, the same characteristics as those of the conventional technique can be sufficiently provided, and this point will be described below. That is, in this embodiment,
The slot 2a is open on the outer peripheral side of the stator core 2, so that the stator coil 3 can be inserted into the slot 2a from the outer periphery of the stator. As a result, the stator coil 3 can be easily inserted into the slot 2a, and the number of windings of the coil can be increased as compared with the related art.

Therefore, if the number of windings of the stator coil 3 is increased, the magnetomotive force (magnetomotive force = number of windings × current) increases even with the same current value, and the generated torque also increases. On the other hand, in terms of performance, it is sufficient that the same torque can be produced, so that the current can be reduced in the end. On the other hand, when the number of turns of the coil increases, the magnetic flux density can be small, so that it is possible to suppress the performance deterioration due to the small saturation magnetic flux density in the thick portion 1b of the housing 1 made of a magnetic aluminum alloy material. Therefore, also with this embodiment, it is possible to obtain an induction motor having the same characteristics as those of the prior art. Further, in this embodiment, since the opening of the slot 2a can be widened, there is an advantage that the winding work is simplified and no skill is required.

By the way, the magnetic aluminum alloy material used in this embodiment has a relatively high conductivity as described above, and in this embodiment, the housing 1
Since the thick wall portion 1b (portion 1c which is the outer peripheral portion of the stator) is integrally formed instead of a laminated structure, an eddy current flows in this portion and the temperature rise of the stator becomes large. May occur.

However, in this embodiment, as described above, the number of windings of the stator coil 3 can be increased, and thus the current for securing the same torque can be small. Therefore, the increase of the eddy current is offset. Therefore, there is no fear that the loss will increase.

Further, in this embodiment, even if the eddy current increases and the temperature of the stator rises, the material of the housing 1 is a magnetic aluminum alloy material having high thermal conductivity. Since the heat transfer is good and high heat dissipation characteristics can be obtained, it is possible to reduce the temperature rise as compared with the prior art.

Next, FIG. 3 shows another embodiment of the present invention.
The embodiment of FIG. 3 differs from the embodiment of FIG. 2 described above in that a protrusion 2c is provided on the outer peripheral portion of the stator core 2 to prevent the stator from rotating. In the stator, a turning force appears due to a reaction of the rotating torque during operation, but according to this embodiment, the protrusion 2c is formed into the inner peripheral surface of the thick portion 1b of the housing 1, so that Even if the mounting strength of the stator core 2 to the meat portion 1b is reduced,
Rotation of the stator can be reliably suppressed.

Next, FIG. 4 shows another embodiment of the present invention. As shown in the figure, a part 2d of the outer peripheral edge of the tooth portion 2b of the stator core 2 made of a laminated body of silicon steel plates is shown. , The base material is fixed by a joining method such as welding, and the others are the same as the embodiment of FIG.

FIG. 5 is also one embodiment of the present invention. In this embodiment, the teeth of the stator core 2 are made so that the magnetic flux in the outer peripheral portion 1c of the stator is easier to pass than in the embodiment of FIG. The outer peripheral end 2e of the portion 2b is extended in the outer diameter direction, and in this embodiment, as shown in the drawing, the outer peripheral end 2e of the tooth portion 2b.
However, it is configured so as to be located outside the position of the brace for holding the stator coil 3.

In the embodiment shown in FIG. 6, the tooth portion 2b is also the same.
Although the outer peripheral end of the tooth portion is extended in the outer radial direction, in this embodiment, the outer peripheral edge 2 of the tooth portion extended in the radial direction is formed.
The shape of f is a taper shape (dovetail shape) that widens in the circumferential direction toward the outer periphery, and the tip of the tooth portion is widened to the extent that the winding work is not impaired.

The purpose of the embodiments of FIGS. 5 and 6 is to make the area of the magnetic path made of a magnetic aluminum alloy material as small as possible to facilitate passage of magnetic flux and to reduce eddy currents. . Therefore, in these examples, as shown in (c) of FIG. 5 and (d) of FIG. 6, the magnetic flux tries to pass as much as possible through the magnetic body part which is a material having a high magnetic permeability and easy passage. Therefore, the tooth portion 2b of the stator core 2 is
The length of the coil is made longer and the opening is narrowed to the extent that it does not interfere with the winding work.This reduces the ampere turns and suppresses the exciting current and eddy current. .

In addition, in these embodiments, the outer peripheral ends 2e and 2f further have the protrusions 2c described in the embodiment of FIG.
Similarly, it also serves as a detent for the stator core 2 and has an advantage that rotation of the stator can be reliably suppressed.

By the way, in the above description, the housing 1
Although the stator core 2 is attached to the thick wall portion 1b by shrink fitting, it may be attached by press fitting.
Alternatively, the stator core 2 may be integrally die-cast when the housing 1 is molded.

[0036]

According to the present invention, the effects listed below can be obtained.

It is possible to provide a small and lightweight rotating electric machine (it is possible to reduce the size by about 30% by volume).

Since the winding work is facilitated, the manufacturing cost can be reduced.

The temperature rise of the rotating electric machine can be reduced.

[Brief description of drawings]

FIG. 1 is a side view with a partial cross section showing an embodiment of a rotating electric machine according to the present invention.

FIG. 2 is a partial front view showing an embodiment of the stator in the rotating electric machine of the present invention.

FIG. 3 is a partial front view showing an embodiment of the stator in the rotating electric machine of the present invention.

FIG. 4 is a partial front view showing an embodiment of the stator in the rotating electric machine of the present invention.

FIG. 5 is a partial front view showing an embodiment of the stator in the rotating electric machine of the present invention.

FIG. 6 is a partial front view showing an embodiment of the stator in the rotating electric machine of the present invention.

FIG. 7 is a side view with a partial cross section showing a conventional example of a rotating electric machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 1a Radiating fin 1b Thick part 2 Stator core 2a Slot 2b Tooth part 2c Protrusion for rotation prevention 2d Part of outer peripheral edge of tooth part 2b 2e, 2f Outer end of tooth part 2g Connection part 3 Stator coil 3a Insulator 3b Sashiki (wedge for coil suppression) 4a, 4b End bracket 5 Shaft 6 Rotor 7 End ring 8 Inner fan 9 Outer fan 10 End cover 10a Wind hole

Claims (2)

[Claims] 1. A rotary electric machine comprising a stator having a winding wound on a substantially cylindrical iron core having slots for housing windings, wherein the iron core is provided with slots on the inner peripheral side thereof. And a cylindrical portion forming a magnetic path on the outer peripheral side, and the cylindrical portion on the outer peripheral side is composed of a cylindrical portion made of a magnetic aluminum alloy material. A rotating electric machine, characterized in that a cylindrical portion made of an alloy material is formed integrally with a housing. 2. The rotary electric machine according to claim 1, wherein the slot is open only on the outer peripheral side of the inner peripheral cylindrical portion.