JP6009830B2 - Fully closed motor - Google Patents

Description

  Embodiments described herein relate generally to a fully-closed electric motor.

  Generally, in a railway vehicle such as a train, a driving electric motor is loaded in a carriage disposed under the floor of a vehicle body, and the rotational force of the electric motor is transmitted to wheels via a gear device to run the vehicle.

  Conventionally, an open type motor that circulates outside air in the machine and cools it has been used for this drive motor. A fully-closed electric motor has been adopted.

Here, the structure of a conventional fully-closed electric motor will be described.
In the fully closed electric motor, an annular stator is attached to the inner periphery of a cylindrical frame, and a plurality of grooves are provided on the inner periphery of the stator, and a stator coil is attached in the grooves.

  A first bearing bracket incorporating a first bearing is attached to one end side of the frame, and a mirror lid that is integrally attached to the frame is disposed on the other end side, and a second bearing is incorporated in the mirror lid. A second bearing housing is attached, and the rotor shaft is rotatably supported by the pair of bearings.

By the way, since the stator coil generates heat during operation and the temperature rises during operation, the outside air is taken in from the cooling air inlet, and the heat generated in the fully enclosed motor is released from the cooling air outlet to the outside space. And cooling is performed.
In this case, in order to improve the cooling efficiency, a pair of cooling disks each having cooling fins is attached to the rotor, and the outside air circulates in the fully-closed electric motor by the fan effect of the cooling disks, and cooling is performed. Heat was exchanged with a disk.
In this case, an annular labyrinth (a minute gap) is provided between the cooling disk and the frame or between the cooling disk and the mirror lid so that the outside air and the inside of the motor are shut off and sealed. I kept the sex.

JP 09-46960 A

In the configuration described above, the outside air taken in as cooling air contains dust, dust, and the like.If this dust accumulates in the vicinity of the labyrinth or enters the inside of the machine from the labyrinth, the performance of the fully-closed electric motor is improved. There was a risk of decline.
Specifically, the frequency of maintenance due to thermal deterioration of grease in the pockets around and around the bearing due to a decrease in capacity (output) due to a decrease in cooling capacity and an excessive increase in the temperature of the bearing Increase.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a fully-closed motor that can prevent dust from entering the fully-closed motor and reduce the frequency of disassembly maintenance.

A fully-closed electric motor according to an embodiment includes a frame, a stator provided on an inner peripheral surface of the frame, a rotor shaft rotatably supported at a position facing the stator, and a rotor attached to the rotor shaft. ing.
The fully-closed electric motor is integrally attached to the rotor shaft, and faces each frame via a labyrinth formed in an annular shape around the rotation axis of the rotor shaft, and cooperates with the frame to surround the periphery of the rotor. A pair of surrounding cooling disks are provided.
Furthermore all-closed electric motor is disposed along a larger radius position than the radius position corresponding to the forming position of the labyrinth disposed annularly, provided with a dust deposition portion of the groove-like depositing dust that enters from the outside Yes.

FIG. 1 is a cross-sectional view of the fully closed electric motor according to the first embodiment. FIG. 2 is an enlarged sectional view of the vicinity of the labyrinth and the cooling air outlet of the first embodiment. FIG. 3 is an explanatory view taken in the direction of the arrow X in FIG. FIG. 4 is an enlarged sectional view of the vicinity of the labyrinth and the cooling air outlet of the second embodiment. FIG. 5 is an enlarged sectional view of the vicinity of the labyrinth and the cooling air outlet of the third embodiment.

Next, embodiments will be described with reference to the drawings.
[1] First Embodiment FIG. 1 is a cross-sectional view of a fully closed motor according to a first embodiment.
The fully-closed electric motor 10 has a frame 11, and a rotor shaft 12 is rotatably supported in the frame 11 via a bearing 13 and a bearing 14.

A rotor (permanent magnet) 15 is fixed to the rotor shaft 12, and the rotor 15 is disposed in a magnetic field generated by a stator coil 16 constituting a stator.
At one axial end of the rotor shaft 12 of the rotor 15, a plurality of cooling fins 17 </ b> F used for cooling are provided, and a cooling disk 17 is provided so as to be rotatable integrally with the rotor 15. Similarly, a plurality of cooling fins 18 </ b> F used for cooling are provided on the other axial end of the rotor shaft 12 of the rotor 15, and a cooling disk 18 is provided so as to be rotatable integrally with the rotor 15.

The bearing 13 is incorporated in a space formed by an end lid 19 and a housing 30 provided on the outer side in the axial direction of the rotor shaft 12 (left side in FIG. 1) than the cooling disc 17.
A gap between the end lid 19 and the cooling disc 17 is formed by a cooling air inlet 20 formed through the end lid 19 and the frame 11 and a cooling air outlet 21 formed through the frame 11. Is formed as a cooling air flow path 22 that communicates with each other.

Here, when the position where the cooling air inlet 20 is provided is the radius r1 from the rotation center CX of the rotor shaft 12, the dust accumulation functioning as a dust accumulation portion communicating from the rotation center CX of the rotor shaft 12 to the cooling air outlet 21. The position where the surface 21W is provided is a position having a radius r2 (> r1) from the rotation center CX of the rotor shaft 12.
This is a position where the centrifugal force at the time of occurrence of the fan effect due to the rotation of the cooling disk 17 is larger, that is, the cooling air outlet 21 is arranged at this position so that the exhaust from the cooling air outlet 21 is efficiently performed. Because.

  Outside air is introduced into the cooling air flow path 22 from the cooling air inlet 20, and the introduced outside air exchanges heat with the cooling disk 17 and is led out from the cooling air outlet 21 to the outside space. Then, cool down.

  Similarly, the bearing 14 is built in a space between an end lid 26 screwed to the outer surface (right side in FIG. 1) of a bearing bracket 25 screwed to the frame 11 so as to face the cooling disk 18. Has been.

  The gap between the bearing bracket (mirror lid) 25 and the cooling disk 18 is formed as a gap between the cooling air inlet 27 formed through the bearing bracket 25 and the bearing bracket 25 and the frame 11. The cooling air flow path 29 is formed to communicate with the cooling air outlet 28. Outside air is introduced into the cooling air passage 29 from the cooling air inlet 27, and the introduced outside air exchanges heat with the cooling disk 18 and is led out from the cooling air outlet 28 to the outside space. Then, cool down.

Here, when the position where the cooling air inlet 27 is provided is the radius r11 from the rotation center CX of the rotor shaft 12, the position where the cooling air outlet 28 is provided is the radius r12 (> r11) from the rotation center CX of the rotor shaft 12. It is said that the position.
This is a position where the centrifugal force at the time of occurrence of the fan effect due to the rotation of the cooling disk 18 is larger, that is, the cooling air outlet 28 is arranged at this position so that the exhaust from the cooling air outlet 28 is efficiently performed. Because.

An annular labyrinth (a minute gap portion) 31 is formed between the outer peripheral portion of the cooling disc 17 and the frame 11.
Similarly, an annular labyrinth (micro gap portion) 32 is formed between the outer peripheral portion of the cooling disk 18 and the bearing bracket 25.
Here, the cooling disk 17 and the cooling disk 18 are integrally attached to the rotor shaft 12 and face the frame 11 via labyrinths 31 and 32 formed in an annular shape around the rotation axis of the rotor shaft 12. In addition, it surrounds the rotor 15 in cooperation with the frame 11.
As a result, the frame 11, the cooling disc 17 and the cooling disc 18 maintain the hermetic airtightness between the interior space and the exterior space, and the rotor 15 is disposed in the interior space in an airtight state. Is isolated. Therefore, since it can reduce that dust reaches the circumference | surroundings of the rotor 15, the frequency of a maintenance can be reduced.

Next, the operation of the fully closed motor according to the first embodiment will be described.
When the fully-closed electric motor 10 is driven, heat is generated in the fully-closed electric motor 10 mainly due to the current flowing through the rotor coil.
As a result, the temperature in the fully-closed electric motor 10 rises due to the heat generated in the fully-closed electric motor 10, but is released from the outer peripheral surface of the frame 11 and the outer peripheral surface of the bearing bracket 25 to the external space.

In parallel with this, the heat generated in the rotor 15 or stored in the rotor 15 is conducted to the cooling disk 17 and the cooling disk 18.
The heat conducted to the cooling disc 17 is released into the cooling air flow path 22 through the cooling fins 17F. The heat released into the cooling air flow path 22 is led out from the cooling air outlet 21 to the outside space by the outside air introduced from the cooling air inlet 20 as indicated by the arrow CW1 with the rotation of the cooling fin 17F.

Similarly, the heat conducted to the cooling disk 18 is released into the cooling air flow path 29 through the cooling fins 18F. The heat released into the cooling air passage 29 is led out from the cooling air outlet 28 to the outside space by the outside air introduced from the cooling air inlet 27 as indicated by the arrow CW2 with the rotation of the cooling fin 18F.
At this time, dust such as dust or dust is taken together by the outside air taken into the cooling air passage 22 and the cooling air passage 29 and flows into the vicinity of the labyrinth 31 and the labyrinth 32.

FIG. 2 is an enlarged sectional view of the vicinity of the labyrinth and the cooling air outlet of the first embodiment.
As shown in FIG. 2, a dust accumulation surface that functions as a dust accumulation portion that communicates from the rotation center CX of the rotor shaft 12 to the cooling air outlet 21 rather than a radius r0 from the rotation center CX of the rotor shaft 12 to the inlet 31E of the labyrinth 31. The radius r2 up to 21 W is large (long) (r0 <r2).

Further, a portion from the entrance 31E of the labyrinth 31 toward the dust accumulation surface 21W forms a slope 35 that functions as a slope portion. As a result, the dust DU taken together with the outside air moves toward the dust accumulation surface 21 </ b> W along the flow of the cooling air and does not stay near the inlet 31 </ b> E of the labyrinth 31.
As a result, the dust DU (indicated by a large number of small circles in FIG. 2) contained in the cooling air reaches the dust accumulation surface (groove) 21W together with the outside air without being taken into the labyrinth 31 and thus into the machine. The air is again discharged to the outside space through the air outlet 21.

A part of the dust DU is not discharged into the space outside the apparatus but is collected on the dust accumulation surface 21W, but the amount thereof is small and is not a problem.
As described above, the labyrinth 31 and the dust accumulation surface 21 </ b> W are arranged through a step due to the provision of the inclined surface 35, so that the dust DU does not collect in the labyrinth 31 and enters the labyrinth 31. Intrusion of dust DU can be suppressed.

  Similarly, as shown in FIG. 1, the portion from the inlet 32E of the labyrinth 32 toward the cooling air outlet 28 forms a slope 36. Therefore, the dust DU taken together with the outside air is near the inlet 32E of the labyrinth 32. Without being stopped, the air is again discharged from the cooling air outlet 28 together with the outside air. As a result, the dust DU does not collect in the labyrinth 32, and the entry of the dust DU into the labyrinth 32 can be suppressed.

  As described above, according to the first embodiment, it is possible to prevent the dust DU contained in the cooling air from being taken into the labyrinths 31 and 32 and thus into the machine when the fully closed electric motor 10 is cooled. The maintenance frequency can be reduced while reliably cooling. That is, maintenance can be facilitated while maintaining the performance of the fully closed electric motor 10 over a long period of time.

[1.1] Modification of First Embodiment In the above description, the shape and arrangement of the cooling air inlets 20 and 27 and the cooling air outlets 21 and 28 have not been described in detail. Alternatively, the opening area of the cooling air outlets 21 and 28 is preferably larger than the opening area of the cooling air inlets 20 and 27 in consideration of the pressure loss in the cooling air channel 29.

FIG. 3 is an explanatory view taken along the arrow X in FIG. 1 as an example of the installation example of the cooling air inlet and the cooling air outlet.
FIG. 3A shows a modified example in which a plurality of cooling air outlets 21 are provided radially with respect to one cooling air inlet 20 along the circumferential direction.

  As shown in FIG. 3A, the opening area of the plurality of cooling air outlets 21 is sufficiently larger than the opening area of the cooling air inlet 20, and is caused by pressure loss in the cooling air flow path 22. Cooling can be reliably performed without impeding the flow of cooling air, and the discharge of dust DU to the outside of the machine can be promoted.

FIG. 3B shows a modification in the case where two cooling air outlets 21 having a long hole shape are provided along the circumferential direction with respect to one cooling air inlet 20.
Also in this modification, the opening area of the two long-hole shaped cooling air outlets 21 is sufficiently larger than the opening area of the cooling air inlet 20, and cooling is caused by pressure loss in the cooling air flow path 22. Cooling can be performed reliably without impeding the flow of wind, and the discharge of dust DU to the outside of the machine can be promoted.

Further, FIG. 3C is a modified example in which one cooling air outlet 21 having a long hole shape is provided along the circumferential direction with respect to one cooling air inlet 20.
Also in this modification, the opening area of one cooling air outlet 21 having a long hole shape is sufficiently larger than the opening area of the cooling air inlet 20, and the cooling air is caused by pressure loss in the cooling air passage 22. The air can be reliably cooled without impeding the flow of the dust, and the discharge of the dust DU to the outside of the machine can be promoted.

[2] Second Embodiment FIG. 4 is an enlarged sectional view of the vicinity of the labyrinth and the cooling air outlet of the second embodiment.
In the first embodiment described above, the slope 35 is formed in the portion from the inlet 31E of the labyrinth 31 toward the dust accumulation surface 21W. However, in the second embodiment, the slope similar to the slope 35 is formed on the labyrinth 31. In this embodiment, a groove 21S is provided that covers the entire circumference of the inlet 31E and holds dust DU that cannot be discharged from the cooling air outlet 21 to the outside space.

  According to the second embodiment, the dust DU contained in the cooling air can be prevented from being taken into the labyrinth 31 and thus into the machine when the fully-closed electric motor 10 is cooled over the entire circumference of the inlet 31E of the labyrinth 31.

In addition, since the dust DU that cannot be discharged from the cooling air outlet 21 to the outside space is temporarily held by the groove 21S, the dust DU is also contained in the labyrinth and eventually when the dust DU is gradually discharged to the outside space. Incorporation into the machine can be suppressed, and the performance of the fully-closed electric motor 10 can be maintained even with a long maintenance cycle.
The above description is only for the cooling air flow path 22 side, but the cooling air flow path 29 can be configured similarly.

[3] Third Embodiment In each of the above embodiments, the slope and the dust accumulation surface are provided before reaching the cooling air outlet. However, in the third embodiment, the slope and the dust accumulation surface are integrated. It is embodiment at the time of forming in.

FIG. 5 is an enlarged sectional view of the vicinity of the labyrinth and the cooling air outlet of the third embodiment.
In the first embodiment described above, the inclined surface 35 is formed in the portion from the inlet 31E of the labyrinth 31 toward the dust accumulation surface 21W. However, in the third embodiment, the cooling air outlet 21 extends from the inlet 31E of the labyrinth 31. In this embodiment, a slope 21SL is provided.

According to the third embodiment, the dust DU contained in the cooling air is less likely to stay on the inclined surface 21SL when the fully-closed electric motor 10 is cooled, and thus can be suppressed from being taken into the labyrinth 31 (inside the machine).
As a result, according to the third embodiment, since the dust DU does not stay in the fully-closed electric motor 10 for a long time, it is possible to suppress the dust DU from being taken into the apparatus, and the fully-closed electric motor 10 even if the maintenance cycle is long. Performance can be maintained.
The above description is only for the cooling air flow path 22 side, but the cooling air flow path 29 can be configured similarly.

[4] Effects of Embodiments As described above, according to each embodiment, the dust DU that is taken into the fully-closed electric motor 10 together with the cooling air and can stay can be reduced, and the maintenance frequency can be reduced. Can do.

In addition, since the cooling performance can be improved, it is possible to reduce the size and weight or increase the capacity (output) as compared with the conventional fully-closed electric motor. At the same time, since the temperature rise of the bearing portion can be suppressed, deterioration of the lubricating grease can be prevented, and the disassembly maintenance cycle of the fully closed electric motor 10 can be extended.
Moreover, it can be suppressed that the circulation of the cooling air is deteriorated due to accumulation of dust DU.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 10 Fully enclosed motor 11 Frame 12 Rotor shaft 13 Bearing 14 Bearing 15 Rotor 16 Stator coil 17 Cooling disk 17F Cooling fin 18 Cooling disk 18F Cooling fin 19 End cover 20 Cooling air inlet 21 Cooling air outlet 21S Groove 21W Dust accumulation surface 22 Cooling air flow path 26 End cover 27 Cooling air inlet 28 Cooling air outlet 29 Cooling air flow path 30 Housing 31, 32, 33 Labyrinth 31E, 32E Labyrinth inlet 35 Slope 35A Slope 36 Slope 41 Slope r11 radius r12 radius CX rotation center DU dust r0 Radius (r0 <r2)
r1 radius (first radius)
r2 radius (second radius, r2> r1)

Claims (5)

Frame,
A stator provided on the inner peripheral surface of the frame;
A rotor shaft rotatably supported at a position facing the stator;
A rotor attached to the rotor shaft;
A pair of members that are integrally attached to the rotor shaft, face the frame via labyrinths formed in an annular shape around the rotation axis of the rotor shaft, and surround the rotor in cooperation with the frame A cooling disc,
A groove-like dust accumulation portion that is disposed along a radial position that is larger than the radial position corresponding to the formation position of the labyrinth disposed in an annular shape, and that accumulates dust that has entered from the outside;
Fully enclosed motor with The entrance of the labyrinth and the dust accumulation part are connected via a slope part,
All closed-form motor according to claim 1 Symbol placement. A cooling air passage is formed around the rotor shaft, and a cooling air outlet of the cooling air passage communicates with the dust accumulation portion.
The fully-closed electric motor according to claim 1 or 2 . The cooling air inlet constituting the cooling air flow path is disposed along the circumference of the first radius r1 centering on the rotation axis of the rotor shaft,
The cooling air outlet is disposed along a circumference of a second radius r2 (> r1) centering on the rotation axis of the rotor shaft.
The fully-closed electric motor according to claim 3 . A plurality of the cooling air outlets are provided on a predetermined circumference,
The fully-closed electric motor according to claim 3 or 4 .

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