JPH08214474A - Dynamo electric machine - Google Patents

Abstract

PURPOSE: To reduce the noise which is produced when a gas discharged from the second ventilating duct of a rotor interferes with the first spacer of a stator. CONSTITUTION: On the stator 5 and rotor 8 of a dynamo electric machine, numerous first and second ducts 15 and 18 through which air is made to flow in the radial direction are intermittently formed in the axial direction. The widths of the openings of the ducts 15 and 18 in the axial direction on a field space side are made different from each other or made not to be faced to each other or end sections of first duct forming spacers 10 are retreated from the position of the slot wedge of the stator 5. Therefore, the pressure of the air flow which varies in the period corresponding to the product of the rotating speed of the rotor 18 and the number of the spacers 10 is dropped and the noise produced when the rotor 8 rotates is reduced.

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 having a stator and a rotor having ventilation ducts for cooling.

[0002]

2. Description of the Related Art In a conventional rotary electric machine of this type, a stator has an iron core block and a plurality of first spacers extending in a radial direction and intermittently arranged in a circumferential direction alternately arranged in an axial direction. As a result, a first ventilation duct through which gas flows from the inner side to the outer peripheral direction is formed between the core blocks, and the rotor extends radially with the core blocks and is arranged intermittently in the circumferential direction. By alternately arranging a large number of second spacers in the axial direction, a second ventilation duct through which gas passes from the rotation center side in the outer peripheral direction is formed between the iron core blocks.

In the rotating electric machine with a duct having such a structure, when the rotor is rotated at a high speed, gas is sucked into the rotating electric machine by the fan action of the rotor, which is a central duct provided on the center side of the rotor. Is distributed to the second ventilation duct of the rotor, is discharged from here to the gap on the outer periphery of the rotor, and then is discharged to the outside of the rotating electric machine through the first ventilation duct of the stator. By such gas circulation, heat generated by copper loss and iron loss of the rotating electric machine is effectively released and cooled.

[0004]

However, in such a rotary electric machine, there is a problem that the rotational noise due to the gas flow is large. Therefore, in the related art, the inner peripheral surface of the stator and the outer peripheral surface of the rotor in the field space are heretofore known. There is a drawback that the rotary electric machine becomes large in size because a large gap between and is set to reduce the pressure fluctuation of the air flow that is a noise source and a large silencer is attached as a sound insulation mechanism. An object of the present invention is to provide a rotating electric machine that can reduce noise caused by the gas discharged from the second ventilation duct of the rotor interfering with the first spacer of the stator.

[0005]

According to a first means of the present invention, a stator is composed of an iron core block and a plurality of first spacers extending in a radial direction and arranged intermittently in a circumferential direction alternately. By arranging in the axial direction, a first ventilation duct through which gas passes from the inner side to the outer peripheral direction is formed between the iron core blocks. Further, by arranging the rotor in the axial direction alternately with the iron core blocks and a plurality of second spacers extending in the radial direction and intermittently arranged in the circumferential direction, the gas is rotated between the iron core blocks on the rotation center side. The second ventilation duct is formed so as to pass from the to the outer peripheral direction. In such a rotary electric machine, further, the intervals of the portions forming the minimum interval among the mutual intervals in the circumferential direction of the plurality of the second spacers are set uniformly for all the second ducts, and the inlet side and the outlet side are The spacing on the sides is set unequal for all the second ducts.

In the second means of the present invention, the stator is configured such that the iron core block and the plurality of first spacers extending in the radial direction and intermittently arranged in the circumferential direction are alternately arranged in the axial direction. Thus, a first ventilation duct through which gas passes from the inner side to the outer peripheral direction is formed between the iron core blocks.
Further, by arranging the rotor in the axial direction alternately with the iron core blocks and a plurality of second spacers extending in the radial direction and intermittently arranged in the circumferential direction, the gas is rotated between the iron core blocks on the rotation center side. The second ventilation duct is formed so as to pass from the to the outer peripheral direction. In such a rotating electrical machine,
Furthermore, among the mutual spacings in the circumferential direction of the plurality of the second spacers, the spacings of the minimum spacing portions are set uniformly for all the second ducts, and the spacings on the outlet side are all the second ducts. Set unevenly.

[0007]

The main cause of noise in the rotating electric machine with the ventilation duct is the first spacer provided so that the discharge airflow from the second ventilation duct on the rotor side forms the first ventilation duct in the stator. It was found that this is because the air flow greatly fluctuates at a frequency equal to the product of the rotation speed and the number of the first spacers. In the above-mentioned configuration according to the present invention, when the rotor is rotated at high speed, its fan action causes
The gas passes through the second ventilation duct to reach the field air, that is, the space around the outer periphery of the rotor, and then passes through the first ventilation duct of the stator and is discharged to the outside of the machine.

At this time, since the second spacers have an unequal mutual spacing at least on the outlet side of the second ventilation duct, the airflow from the second ventilation duct interferes with the first spacers to cause periodicity. The pressure that fluctuates, that is, the pressure that fluctuates at a frequency equal to the product of the number of revolutions and the number of the first spacers is reduced, thereby reducing the rotational noise. In this case, the rotor conductor traversing the second ventilation duct is subjected to a uniform cooling action due to the uniform minimum spacing of the second spacers.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. 1 and 2. In particular, FIG. 2 shows the cross section of the stator and the rotor at right angles to the horizontal for convenience sake. There is. The rotating electric machine 1 includes a stator 5 arranged in a stator frame 4 having an intake port 2 and an exhaust port 3, and a rotating shaft 7 mounted on a bearing bracket 6 so as to be located in a field space of the stator 5.
It consists of a rotor 8 supported via. The stator 5 has an iron core block 9 and a large number of plate-shaped first spacers 10 extending in the radial direction and intermittently arranged in the circumferential direction, which are alternately arranged in the axial direction, and these are held by a stator pressing plate. It is integrated by 11. Reference numeral 12 is a stator winding inserted in the slot 13 and held by the slot wedge 14.

As a result, the stator 5 has a structure in which the first spacers 10 form the first ventilation ducts 15 through which the gas flows from the inner side to the outer peripheral direction between the iron core blocks 9. The rotor 8 includes a plurality of second cores 16 extending in a radial direction with the core block 16 and arranged intermittently in a circumferential direction.
The spacers 17 are alternately arranged in the axial direction, and these are integrated by a clamp (not shown). By this arrangement, the second ventilation duct 18 through which the gas passes between the iron core blocks 16 in the outer peripheral direction from the rotation center side is formed. It is formed. In this case, the core block 16 of the rotor 8 is
Is supported by the rotary shaft 7 via a rib member 19 arranged so as to project radially around the air intake duct 20. The rib member 19 forms an intake duct 20 communicating with the second ventilation duct 18. . A partition plate 20a for equalizing the flow of gas is arranged in the middle of the intake duct 20.

Each of the second spacers 17 has a slender rhombus in cross section as shown in FIGS. 2 and 3 so that the second spacers 17 are tapered on the entrance / exit side, and the mutual intervals in the circumferential direction are central. It is the smallest in the part. Especially the spacer 1
Among the mutual intervals of 7, the intervals of the part forming the minimum interval are set to be uniform (size b0) for all the second ventilation ducts 18, and the intervals of the parts forming the entrance and exit are the sizes a1, a2, a3. As shown in (a1 ≠ a2 ≠ a3), they are set unevenly. Incidentally, 8a is a rotor conductor, and penetrates through the second spacer 17 as shown in FIG. In FIG. 3, the conductor 8a, the rib member 19, and the rotary shaft 7 are not shown. Reference numeral 5a is an air guide cover arranged so as to cover coil end portions of both ends of the stator 5 in the axial direction.

Next, the operation of the above configuration will be described. When the rotor 8 is rotated at a high speed, the fan action causes gas to be sucked into the inside of the stator frame 1 through the intake port 2, and the gas is introduced through the intake duct 20 into the second ventilation ducts 6 of the rotor 8. Through the first ventilation ducts 15 of the stator 5, and is discharged from the exhaust port 3 to the outside of the machine. The stator winding 12 and the rotor conductor 8a are cooled by such gas flow.

In the above circulation of gas, each second
Of the second ventilation ducts 18 are arranged at unequal intervals except for the minimum mutual spacing portions thereof, in other words, the circumferential width of at least the outlet side of each second ventilation duct 18 is the inlet of the first ventilation duct 15. However, the flow velocity of the air flow that interferes with the first spacer 10 is not uniform. As a result, the pressure of the air flow discharged from the second ventilation duct 18 varies periodically due to the interference with the first spacers 10, that is, the frequency that is equal to the product of the number of revolutions and the number of the first spacers 10. The pressure applied is reduced, which reduces rotational noise.

In this case, the rotor conductors 8a traversing the inside of the second ventilation duct 18 are uniformly cooled by the air flow having a uniform flow velocity because the second spacers 17 have a uniform minimum interval. In the first embodiment, the circumferential widths of the inlet and the outlet of the second ventilation duct 18 are uneven, but as shown in FIG. 3 as the second embodiment, the circle of the inlet of the second ventilation duct 18 is The second spacers 21 may be arranged so that the circumferential widths (c0 = c0 = c0) are made uniform and the widths of the outlets (a1 ≠ a2 ≠ a3) are made uneven.
The same effect as above can be obtained.

The third embodiment shown in FIG. 5 has a stator 5
The second dimension for forming the second ventilation duct 22 on the rotor 8 side, where e1 is the axial dimension of the first spacer 10 disposed on the side, and thus the axial dimension of the first ventilation duct 15. The axial dimension of the spacer 23, that is, the axial dimension of the first ventilation duct 22 is set to e2 which is larger than the above e1, and the other portions are the same as those of the second embodiment shown in FIG. is there.

According to this structure, since e1 <e2, a part of the air flow discharged from the second ventilation duct 22 collides with the inner peripheral surface of the field space of the stator 5, and thereafter, It flows into the ventilation duct 15 of No. 1 while being throttled. At this time,
Since the pressure of the air flow is reduced, the pressure that fluctuates periodically as described above can be reduced even more effectively, and a further reduction in rotational noise can be expected.

The fourth embodiment shown in FIG. 6 has a stator 5
The first ventilation duct 25 formed by the first spacer 24 on the side and the second ventilation duct 27 formed by the second spacer 26 on the side of the rotor 8 do not directly face each other and are staggered. , The other part is shown in FIG.
It has the same configuration as that of the embodiment. According to this configuration, all of the airflow discharged from the second ventilation duct 27 once collides with the inner circumferential surface of the field space of the stator 5, and then the first airflow.
Since it flows into the ventilation duct 25 while being narrowed down, the same or more effects as those of the third embodiment can be obtained.

The fifth embodiment shown in FIG. 7 has a stator 5
The position of the field space side (rotation center side) end of the first spacer 28 for forming the first ventilation duct 15 on the side is retracted in the outer peripheral direction by a predetermined dimension from the slot wedge 14. The other parts have the same structure as the second embodiment shown in FIG. According to this configuration, the airflow discharged from the second ventilation duct on the rotor side interferes with the first spacer 28 after the pressure is reduced due to the collision with the stator winding, so that the noise reduction effect is achieved. Is further improved. It goes without saying that the configuration shown in FIGS. 4 to 7 may be combined with the configuration shown in FIG.

[0019]

According to the present invention, at least the axial width of at least the outlet of the second ventilation duct provided in the rotor is set to be uneven in the circumferential direction, so that the air flow and the stator The noise caused by the periodic pressure fluctuation depending on the product of the number of the first spacers provided to form the first ventilation duct on the side can be effectively reduced, and the first By making the axially facing relationship with the second ventilation duct uneven or non-facing, or by retracting the position of the end of the first spacer on the field space side from the slot wedge position. A rotating electric machine that can reduce noise more effectively can be provided.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view of a rotary electric machine showing a first embodiment of the present invention.

FIG. 2 is a vertical sectional view of a second spacer portion shown in FIG.

FIG. 3 is a vertical cross-sectional view showing the main parts of the stator and the rotor in the first embodiment which are horizontally developed.

FIG. 4 is a view corresponding to FIG. 2 showing a rotor according to a second embodiment.

FIG. 5 is a schematic side view showing a positional relationship between a stator and a rotor according to a third embodiment.

FIG. 6 is a view corresponding to FIG. 4 showing a fourth embodiment.

FIG. 7 is a view corresponding to FIG. 3 showing a stator according to a fifth embodiment.

[Explanation of symbols]

1 is a rotating electric machine, 5 is a stator, 8 is a rotor, 10, 21,
24 and 28 are first spacers, 12 is a stator winding, and 13
Is a slot, 14 is a slot wedge, 15 is a first ventilation duct, 17, 21, 23 are second spacers, 18, 22,
Reference numeral 27 is a second ventilation duct.

Claims (5)

[Claims] 1. An iron core block and a large number of first spacers extending in a radial direction and intermittently arranged in a circumferential direction are alternately arranged in an axial direction so that gas is introduced between the core blocks from the inner side. A stator in which a first ventilation duct passing in the outer peripheral direction is formed, and a large number of stators that are positioned in the field space of the stator and extend in the radial direction with the core block and are arranged intermittently in the circumferential direction. A rotary electric machine including a rotor in which a second ventilation duct is formed between the iron core blocks by alternately arranging the second spacers in the axial direction between the iron core blocks. The second
Of the spacers in the circumferential direction, the intervals of the minimum interval portions are set uniformly for all the second ducts, and the intervals on the inlet side and the outlet side are unequal for all the second ducts. A rotating electrical machine characterized by being set to. 2. A core block and a large number of first spacers extending in a radial direction and intermittently arranged in a circumferential direction are alternately arranged in the axial direction so that gas is introduced between the core blocks from the inner side. A stator in which a first ventilation duct passing in the outer peripheral direction is formed, and a large number of stators that are positioned in the field space of the stator and extend in the radial direction with the core block and are arranged intermittently in the circumferential direction. A rotary electric machine including a rotor in which a second ventilation duct is formed between the iron core blocks by alternately arranging the second spacers in the axial direction between the iron core blocks. Out of the mutual spacings of the two spacers in the circumferential direction, the spacings of the portions that form the minimum spacing are set uniformly for all the second ducts, and the spacings on the outlet side are unequal for all the second ducts. Setting A rotating electrical machine characterized by being fixed. 3. The mutual spacing of the second spacers forming the second duct is set to a value larger than the mutual spacing of the first spacers forming the first duct. The rotating electric machine according to 2. 4. The field spacer side end portion of the first spacer forming the first ventilation duct is recessed in the outer peripheral direction with respect to the slot wedge of the stator. Rotary turning machine. 5. The rotating electric machine according to claim 1, wherein the inlet of the first duct and the outlet of the second duct are set in a non-opposing relationship.