JPH0759292A - Rotating electric machine - Google Patents

Abstract

PURPOSE:To prevent a housing from being deformed even if a stator is assembled to the housing by forming an inner rib and the housing at the outer periphery of the stator with aluminum alloy in one piece. CONSTITUTION:A housing 1 is formed by performing die cast casting of aluminum alloy and a plurality of inner ribs la are allowed to protrude in axial direction at the inner periphery of the housing 1. Even if an external cooling door 9 rotates along with the rotation of a shaft 5 and external air taken from a wind hole 10a of an end cover 10 passes through a ventilation hole 11a provided at an end bracket 2a and circulates a passage 12 demarcated by the housing 1, a core 3A of a stator 3, and an inner rib 1a, thus cooling the stator 3. As a result, the cooling effect can be positively increased and it becomes necessary to assemble the stator 3 to the inner rib 1a, thus solving problems due to press fit, etc.

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 suitable for improving the cooling efficiency of a rotor provided in the rotary electric machine.

[0002]

2. Description of the Related Art As a conventional motor as a rotating electric machine, there is one shown in FIGS. In the motor shown in the figure, a cylindrical housing 1 having both axial ends open is made of cast iron, and a plurality of inner ribs 1a are provided on the inner circumference of the cast iron housing 1 so as to project in the axial direction. The stator 3 is attached between the inner ribs 1a. The stator 3 has a wound stator coil 4. In addition, the end brackets 2a are provided on both ends of the housing 1 in the axial direction.
2b is attached, and the shaft 5 is supported by the bearing via the bearing. One end side of the shaft 5 is inserted through one end bracket 2b to form an output shaft, and the other end side is inserted through the end bracket 2a to which an external cooling fan 9 is attached. Further, an end cover 10 is attached to the outer circumference of the other end bracket 2a, and the end cover 10 is
The external cooling fan 9 and the end bracket 2a are large enough to cover them, and a plurality of air holes 10a are provided in the end surface thereof. On the other hand, in the housing 1, a rotor 6 is fixed at an intermediate position corresponding to the stator 3 of the shaft 5, and the rotor 6 has a secondary conductor bar (not shown), an end ring 7, and a cooling fan 8. Then, when the shaft 5 rotates due to the magnetic action formed by the rotor 6 and the stator 3, the external cooling fan 9 also rotates accordingly, so that the outside air is taken into the motor from the air holes 10a of the end cover 10. ,
The outside air taken in passes through the ventilation hole 11a provided in the end bracket 2a and passes through the radial gap between the housing 1 and the stator 3, that is, the image is formed by the housing 1, the stator 3 and the inner rib 1a. While cooling the stator 3 by flowing through the formed passage 12 as shown by the arrow in FIG. 8, both the stator 3 and the rotor 6 are also caused to flow by flowing the gap between the stator 3 and the rotor 6. I try to cool. Also, the inner rib 1a,
The outside air flowing through the gaps between the stator 3 and the rotor 6 is sucked in by the rotation of the cooling fan 8 of the rotor 6 as shown by the arrow in FIG. 7, and passes through the ventilation holes 11b provided in the end bracket 2b. It is discharged to the outside. In addition, as a related art, there is JP-A-58-89044.

[0003]

By the way, the above-mentioned prior art is required to more efficiently dissipate the heat generated inside the motor as a rotating electric machine and thereby to reduce the size. However, in the conventional technique, since the housing 1 and the inner rib 1a are made of cast iron, it is difficult to further improve the heat radiation effect. Therefore, the housing 1 is made of an aluminum alloy material having a high thermal conductivity (specific heat is about twice that of steel, thermal conductivity is about three times that of steel), and the heat generated inside can be easily transferred to the housing. Conceivable. However, the temperature inside the motor cannot be remarkably reduced only by changing the material of the housing 1 to an aluminum alloy, and this tendency is remarkable especially in a rotating electric machine in which both ends of the housing 1 are open. There is a problem that the characteristics of wood cannot be utilized.
Further, in the prior art, the stator laminated iron plates constituting the stator are fixed in advance to form a laminated iron core, and the laminated iron core is press-fitted (or a baking spring) between the inner ribs 1a of the housing 1 to be assembled. In that case, there is also a problem that the housing 1 is deformed.

In view of the above-mentioned problems of the prior art, an object of the present invention is to improve the cooling structure for the heat generated inside, and also to deform the housing even when the stator is assembled to the housing. An object of the present invention is to provide a rotating electric machine that can prevent the above.

[0005]

In a rotating electric machine of the present invention, a cylindrical housing having both axial ends opened,
A plurality of inner ribs are provided on an inner peripheral portion of the housing to form an air flow passage, and a stator is arranged at an inner position of the housing via the inner rib, and an outer periphery of the stator is provided. The inner rib and the housing are integrally formed of an aluminum alloy.

[0006]

In the present invention, as described above, since the housing and the inner rib are integrally formed on the outer periphery of the stator with an aluminum alloy, as compared with the conventional housing formed of cast iron, The thermal conductivity is good, so that the heat generated inside is satisfactorily transferred from the stator core to the housing via the inner ribs. In this case, since the contact area with the stator is increased by increasing the number of inner ribs, the conductivity to the housing is further improved.
As a result, the heat radiation effect can be surely increased and the temperature rise can be suppressed, and thus the size reduction can be realized. Further, since the housing and the inner rib are formed integrally with the stator core, not only is it unnecessary to assemble the stator to the inner rib of the housing, but also to fix the laminated iron plate of the stator. become. Moreover, since it is not necessary to press-fit the stator into the housing as in the prior art,
Problems associated with press fitting etc. can be solved. As a result, the assemblability is improved and the number of manufacturing steps can be reduced.

[0007]

Embodiments of the present invention will be described below with reference to FIGS. 1 and 2 show a first embodiment in which a rotating electric machine according to the present invention is applied to a motor. In the motor of the embodiment, a cylindrical housing 1 having both axial ends open is formed. The housing 1 is formed by die-casting an aluminum alloy in consideration of weight reduction and thermal conductivity, and a plurality of inner ribs 1a are formed on the inner circumference of the housing 1 in the axial direction as shown in FIG. It is installed in the plural toward. Each of the inner ribs 1a is
The stator 3 is mounted and air is circulated in the passages 12 between the inner ribs 1a. The inner ribs of the housing 1 are provided radially at equal intervals in the inner circumference of the housing 1 and are radially projected. It has the same length. Therefore, the housing 1 and the inner rib 1a are integrally formed. The stator 3 is formed between the inner ribs 1a. That is, in the stator 3, for example, after the laminated iron plate of the stator and the stator coil 4 are set in the molding die of the housing 1, the stator core 3A is formed by die casting an aluminum alloy in the molding die. It is formed at the tip of the inner rib 1a.

End brackets 2a and 2b are attached to both ends of the housing 1 in the axial direction, and a shaft 5 is supported on the end brackets 2a and 2b via bearings. One end side of the shaft 5 is inserted through one end bracket 2b to form an output shaft, and the other end side is inserted through the end bracket 2a to which an external cooling fan 9 is attached. Further, an end cover 10 is attached to the outer periphery of the other end bracket 2a, and the end cover 10 has a size capable of covering the external cooling fan 9 and the end bracket 2a, and an air hole 10 is formed on the end surface thereof.
A plurality of a are provided. On the other hand, in the housing 1, a rotor 6 is fixed at an intermediate position corresponding to the stator 3 of the shaft 5, and the rotor 6 has a secondary conductor bar (not shown), an end ring 7, and a cooling fan 8. In the motor having the above-described configuration, when the shaft 5 rotates due to the magnetic action formed by the rotor 6 and the stator 3, the external cooling fan 9 also rotates accordingly, so that the outside air is blown from the air holes 10a of the end cover 10. Is taken into the motor as shown by the arrow a, and the taken-in outside air passes through the ventilation holes 11a provided in the end bracket 2a and passes through the passage 12 which is a gap between the housing 1 and the stator 3, that is, the housing. 1 and the core 3A of the stator 3 and the passage 12 defined by the inner rib 1a
While cooling the stator 3 by flowing as indicated by the arrow B in FIG. 1, and flowing through the gap between the stator 3 and the rotor 6 guided by the cooling fan 8 as indicated by the arrow C, the stator 3 , Both the rotor 6 are also cooled. Further, the outside air that has flowed through the inner ribs 1a and the gap between the stator 3 and the rotor 6 is
Of the cooling fan 8 is sucked in as shown by the arrow D in FIG. 1 and the ventilation holes 11b provided in the end bracket 2b.
After that, it will be discharged to the outside. In the embodiment, as described above, the housing 1 and the inner rib 1a are integrally formed on the outer circumference of the iron core 3A of the stator 3, and
Since it is made of an aluminum alloy, it is possible to reduce the weight and to improve the thermal conductivity as compared with the case where the housing is made of cast iron as in the prior art. Therefore, the heat generated inside the motor causes the stator 3 Good transmission from the iron core 3A to the housing 1 via the inner rib 1a. in this case,
If the number of the inner ribs 1a is increased, the contact area with the iron core of the stator 3 is increased accordingly, so that the conductivity to the housing 1 is further improved. As a result, the open housing 1
Even if it is used, since the heat dissipation (cooling) effect can be surely increased and the temperature rise can be suppressed, the miniaturization can be realized by that much, and the miniaturization of about 30% in volume ratio can be achieved as compared with the conventional technology. . Further, since the housing 1 and the inner rib 1a are integrally formed on the outer circumference of the stator core 3A as described above,
Not only is it unnecessary to assemble the stator 3 to the inner rib 1a, but it is also unnecessary to fix the laminated iron plate of the stator 3. Moreover, since it is not necessary to press fit the stator into the housing as in the prior art, the problems associated with press fitting can be solved. As a result, the assemblability is improved and the number of manufacturing steps can be reduced.

3 to 7 respectively show other embodiments of the present invention. In the embodiment shown in FIGS. 3 to 5, the stator 3
4, a dovetail groove 3B as shown in FIG. 4 is formed in advance on the outer peripheral portion of the stator core 3A forming the stator core 3A, and the stator laminated core and the stator coil 4 provided with the dovetail groove 3B are attached to the housing 1
Then, the housing 1, the inner ribs 1a, and the stator core 3A are integrally molded by setting in a molding die of No. 1 and then casting an aluminum alloy into the mold. In this example, when formed as described above, the tip portion 1b of the inner rib 1a of the housing 1 is formed.
Is formed into a shape that fits into the dovetail groove 3B of the stator core 3A, so that the inner rib 1a is different from that of the first embodiment.
And the stator 3 are more firmly fixed to each other, and the structural strength between the stator 3 and the housing 1 can be increased accordingly. Regarding the heat radiation effect and the assembling property, the same effects as those of the first embodiment can be obtained. The embodiment shown in FIGS. 6 and 7 does not use the above-mentioned housing, but is applied to a rotary electric machine in which the usage environment is good, such as problems with strength. That is, in this case, the groove 3B is provided in the outer peripheral portion of the stator core 3A in advance, and the outer periphery of the stator core 3A and the inner rib 1a are die-cast with an aluminum alloy to form the outer peripheral portion of the stator. The inner rib 1a is integrally formed. According to this example,
Since the inner ribs 1a are radially provided at the outer peripheral position of the stator 3, the heat from the stator 3 can be radiated from the inner ribs 1a, and the outer surface of the inner ribs 1a is opened to the outside. Since it is in the form, it is possible to increase the heat radiation effect, and it is useful for a small-capacity rotary electric machine that does not require an outer cover (housing).

[0010]

As described above, according to the present invention, the housing and the inner rib are integrally formed of the aluminum alloy on the outer periphery of the stator, and the heat generated inside passes through the inner rib from the stator. Since it is configured to transmit well to the housing, it is possible to suppress the temperature rise by surely increasing the heat dissipation effect, and it becomes unnecessary not to assemble the stator to the inner rib of the housing, and the stator lamination It is not necessary to fix the iron plate alone, the assembling property is improved, and the number of manufacturing steps can be reduced. As a result, it is possible to provide a rotary electric machine that is small and easy to manufacture.

[Brief description of drawings]

FIG. 1 is a partially cutaway overall view showing a first embodiment in which a rotating electric machine according to the present invention is applied to a motor.

FIG. 2 is an enlarged front view of a main part showing a relationship among a housing, inner ribs, and a stator.

FIG. 3 is an enlarged front view of essential parts of a housing, inner ribs, and a stator, showing another example of the rotating electric machine according to the present invention.

FIG. 4 is a partially cutaway front view showing a stator.

FIG. 5 is a side view of a main part showing an assembled state.

FIG. 6 is a side view of a main part showing still another example of the rotating electric machine according to the present invention.

FIG. 7 is a partially cutaway front view showing inner ribs and a stator.

FIG. 8 is an explanatory diagram showing a configuration example of a conventional rotary electric machine.

FIG. 9 is an explanatory view showing a relationship among a housing, an inner rib, and a stator in a conventional technique.

[Explanation of symbols]

1 ... Housing, 1a ... Inner rib, 3 ... Stator, 3A ... Stator core.

Claims (1)

[Claims] 1. A tubular housing having both axial ends open, a plurality of inner ribs projecting from an inner peripheral portion of the housing to form an air flow passage, and an inner rib at an inner position of the housing. A rotary electric machine, comprising: a stator disposed through the inner rib and a housing integrally formed on the outer periphery of the stator with an aluminum alloy.