JPH06261484A - Electric rotating machine - Google Patents

Abstract

PURPOSE:To enhance rigidity of frame and to restrain increase of no-load current by integrally casting a magnetic material between inner and outer diametral parts of a motor frame made of an aluminum alloy. CONSTITUTION:A motor comprises a rotor 7 carried on a shaft 6, and a stator 4 fixed to the frame 2. The frame 2 is formed into a cylinder having opposite open ends with cooling fins 2a being provided on the outer peripheral part thereof. A magnetic metal lath 1 is integrally cast between inner and outer diameters of the frame 2, i.e., in an aluminum alloy forming the frame 2. This structure reduces the weight of motor, enhances rigidity of the frame 2, and increases permeability to restrain increase of no-load current.

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, and more particularly to improvement of a cast frame which is one of the jackets of the rotary electric machine.

[0002]

2. Description of the Related Art FIG. 6 is a partial cross-sectional side view showing the appearance of an induction motor as an example of a conventional rotary electric machine. In the figure, 61 is a cylindrical frame formed by casting an iron-based material that is the outer cover of a rotating electric machine, and 61a is this frame.
A large number of frame radiating fins are provided radially on the outer periphery of the frame 61 and are integrally cast with the frame 61. Reference numeral 62 denotes a laminated core of a thin silicon steel plate, which is a stator of a rotary electric machine in which a coil 63 is wound around a plurality of slots provided on the inner peripheral portion of the laminated core. The frame 61 has the purpose of protecting the stator and the inside of the rotating electric machine and transmitting the heat generated by the stator during the operation of the rotating electric machine to the frame and radiating the heat from the frame to the surroundings of the rotating electric machine.

[0003]

The frame of the conventional rotating electric machine is constructed as described above, and when the weight saving of the rotating electric machine is strongly demanded, an aluminum alloy is used as the material of the frame 61. However, the Young's modulus is as small as about 1/3 of the Young's modulus of iron-based materials, for example, gray cast iron, and the mechanical strength, especially the rigidity of the frame is lower than that of iron-based materials. There was a point. Further, when the frame is made of an aluminum alloy material, there is a problem that the magnetic permeability decreases and the exciting current increases. That is, generally, when the stator coil is energized, a magnetic circuit is formed in the stator. Particularly in a rotating electric machine with a high magnetic load, a magnetic circuit is formed in a part of the frame. In the case of the aluminum alloy single-piece frame, it is a non-magnetic material, and since the magnetic permeability is low, a magnetic circuit is not formed in the frame and the no-load current increases significantly.

The present invention has been made in order to solve the above problems, and is made of an aluminum alloy material.
It is an object of the present invention to easily obtain an aluminum alloy frame which has excellent mechanical strength and does not increase the no-load current in a rotating electric machine in which the frame is manufactured.

[0005]

SUMMARY OF THE INVENTION The present invention is a frame for a rotary electric machine made of an aluminum alloy material, and is integrally cast into the frame between the inner diameter portion and the outer diameter portion of the frame. It has an encased metal lath or expanded metal.

[0006]

In the aluminum alloy frame of the rotating electric machine according to the present invention, the metal lath or expanded metal is cast integrally with the frame, so that the rigidity of the frame is improved by the effect of the composite material. Further, since the metal lath and expanded metal are magnetic materials, the one obtained by integrally casting the metal lath on the frame has an improved magnetic permeability as compared with a single aluminum alloy and can suppress an increase in no-load current.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. FIG. 1 shows an external side view of the motor. The aluminum alloy frame 2 in which the metal lath 1 is integrally cast is formed into a cylindrical shape with both ends in the axial direction open, and a plurality of cooling fins 2a are installed on the outer peripheral portion in the vertical and horizontal directions (or in the radial direction).
Have. Between the inner diameter portion and the outer diameter portion of the frame 2,
Similar to the frame 2, the cylindrical metal lath 1 is formed integrally with the frame by casting. A stator 4 is attached to the frame 2 and a shaft 6 is rotatably supported. The stator 4 has a stator coil 5 attached to the inner peripheral wall of the frame 2 and wound. The end brackets 3a and 3b having fitting portions are attached to the fitting portions at both ends of the frame 2, and the end brackets 3a and 3b are screwed to the frame 2 by bolts. The shaft 6 is supported via the end brackets 3a and 3b and bearings, one end of which is inserted through the end bracket 3b to form an output shaft, and the other end of the shaft 6 is inserted through the end bracket 3a. An external cooling fan 10 (hereinafter referred to as an external fan) is fixedly attached. A cover 11 (hereinafter referred to as an end cover) that is larger than the outer diameter dimension of the outer fan 10 and covers the outer fan 10 and the outer diameter portion of the end bracket 3a or the vicinity of the outer peripheral portion of the frame 2 in the axial direction is provided. There is. One end of the end cover 11 is provided with a plurality of air holes 11a (hereinafter, referred to as ventilation openings) for taking in outside air with the outside fan 10. On the other hand, the other end is formed into an open cylindrical shape or a deformed cylindrical shape, and the end bracket 3
The ventilation passage is formed by a radial gap between the a and the outer diameter portion of the frame 2. The motor closes the openings at both ends of the frame 2 with the end brackets 3a and 3b, and the motor sucks the outside air from the ventilation inlet 11a of the end cover 11 by the outer fan 10, and the end bracket 3a, Outside air is ventilated on the outer surfaces of the frame 2 and the end bracket 3b to cool them. A rotor 7 is provided at an intermediate position of the shaft 6 in the frame 2 so as to face the stator 4, and the rotor 7 has a secondary conductor bar and an end ring 8 which are not shown. The internal cooling fan 9 (hereinafter, referred to as an internal fan) is composed of a plurality of blade blades provided on both end surfaces of the end ring 8 of the rotor 7 so as to project along the axial direction. is doing. The rotor 7 and the stator 4
When the shaft 6 rotates due to the magnetic action formed by and, the inner fan 9 and the outer fan 10 also rotate,
Due to the rotation, the outside air is passed from the ventilation inlet 11a of the end cover 11 to the respective end brackets 3a as indicated by the arrow a,
Outside air is ventilated on the outer surfaces of the frame 2 and the end bracket 3b to cool them. On the other hand, after passing through the inner fan 9 while cooling the rotor 7, the end ring 8, the stator coil 5a side, and both end surfaces of the stator 4, the inside of the inside has a relatively low temperature rise compared to the frame 2. Bracket 3
The structure is such that it is cooled when passing through parts a and 3b.

Next, the detailed structure of the frame will be described with reference to FIGS. 2, 3, 4, and 5.

FIG. 2 shows an external side view of the frame. Figure 3
Shows an external front view of the same as above. FIG. 4 shows an external view of the metal lath 1. FIG. 5 shows an external view of the expanded metal.

The metal lath 1 is formed between the inner diameter portion and the outer diameter portion of the housing 2 into a tubular shape similar to the frame, and is cast integrally with the frame. At this time, the length of the metal lath in the axial direction is rational if it is any length equal to or less than the length of the frame in the axial direction.

As shown in FIG. 3, the metal lath 1 is cast integrally with the frame between the inner diameter portion and the outer diameter portion of the frame 2.

Although FIG. 4 shows an example of the metal lath, the expanded metal 51 shown in FIG. 5 may be used instead of the metal lath.

If the metal lath is cast integrally with the aluminum alloy frame, the frame is formed for the above reason.
A magnetic circuit is formed in the frame to prevent an increase in no-load current. The material of the metal lath or expanded metal may be a magnetic material such as mild steel, but is not limited to mild steel and may be any magnetic material.

As described above, according to this embodiment,
By constructing a frame by casting a metal lath or expanded metal integrally with the frame between the inner diameter portion and the outer diameter portion of the aluminum alloy frame, Since the magnetic material having high mechanical strength is arranged inside the frame, the rigidity of the frame can be improved. 2. In particular, metal laths or expanded metals are net-like and are cast integrally inside the frame,
The disadvantage that the aluminum alloy is weak in strength can be compensated for by a simple method without deteriorating the lightweight characteristic of the aluminum alloy, and as a result, the rigidity of the frame can be improved. 3. As a result, the application of the rotary electric machine using the aluminum alloy frame can be expanded to, for example, pressure and explosion proof. 4. Since the magnetic material is placed inside the frame, relatively thin steel plates and reticulated metal laths can easily be widely placed over the entire frame, increasing the no-load current peculiar to the magnetic material frame. This can be effectively prevented, and as a result, a small rotating electric machine can be provided. 5. Since the metal lath or expanded metal is cast integrally with the frame between the inner diameter portion and the outer diameter portion of the aluminum alloy frame, it is advantageous in preventing rust of the metal lath or expanded metal. 6. Since the metal lath or expanded metal is cast integrally with the frame between the inner diameter portion and the outer diameter portion of the aluminum alloy frame, the number of assembling steps does not increase, which is advantageous. And so on.

Although the metal lath and the expanded metal have been described above as examples, the present invention is not limited to these as long as they have the same effect. For example, a perforated sheet of steel plate or a combination of parallel bars can be used. Also, a simple steel plate or the like can be used as long as it has a size that can be arranged between the inner diameter portion and the outer diameter portion of the frame. Further, although the case where the metal lath or expanded metal is cast has been described by taking the frame 2 as an example, when the end brackets 3a and 3b are made of aluminum alloy, a metal lath or expanded metal may be used inside the end brackets 3a and 3b as necessary. It can be arranged in the.

[0016]

According to the present invention, it is possible to easily obtain an aluminum alloy frame which has excellent mechanical strength and does not increase the no-load current in a rotating electric machine in which the frame is made of an aluminum alloy material. There is an effect that can be done.

[Brief description of drawings]

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

FIG. 2 is a side view of an external partial cross-section of a frame showing an embodiment of the present invention.

FIG. 3 is an external front view of a frame showing an embodiment of the present invention.

FIG. 4 is an external view of a metal lath showing an embodiment of the present invention.

FIG. 5 is an external view of an expanded metal showing an embodiment of the present invention.

FIG. 6 is a partial cross-sectional side view of an outer appearance of a conventional rotating electric machine.

[Explanation of symbols]

1 ... Metal lath, 2 ... Frame, 2a ... Cooling fins, 3a, 3b ... End bracket, 4 ... Stator,
5, 5a ... Stator coil, 6 ... Shaft, 7 ... Rotor, 8 ... End ring, 9 ... Cooling fan, 10 ... Outer fan, 11, 11a ... End cover.

Claims (5)

[Claims] 1. A rotating electric machine frame made of an aluminum alloy material, wherein a magnetic material is arranged between an inner diameter portion and an outer diameter portion of the frame. 2. The rotating electric machine according to claim 1, wherein the magnetic material disposed between the inner diameter portion and the outer diameter portion of the frame is cast integrally with the frame. 3. The rotating electric machine according to claim 1, wherein the magnetic material is a net-shaped magnetic material. 4. A frame of a rotary electric machine made of an aluminum alloy material, characterized in that a metal lath is cast integrally with the frame between an inner diameter portion and an outer diameter portion of the frame. Rotating electric machine. 5. A frame of a rotary electric machine made of an aluminum alloy material, wherein expanded metal is cast integrally with the frame between an inner diameter portion and an outer diameter portion of the frame. And rotating electrical machinery.