JP2007097325A - Totally enclosed motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the size and weight of a totally enclosed motor with a heat exchanger mounted thereto. <P>SOLUTION: The totally enclosed type motor has: an inside air fan 11 for circulating inside air and; an outside air fan 14 for ventilating outside air installed on a rotor shaft 9. Its outer frame 2 is mounted with the heat exchanger 20 for exchanging heat between circulated inside air and ventilated outside air. As the heat exchanger 20, a cross-flow total heat exchanger is installed, and the outside air fan 14 is disposed inside one shield 3 to pass the outside air, which is sucked in through a ventilating inlet hole 28 through the heat exchanger 20. The inside air fan 11 is integrally constructed with the outside air fan 14 back to back. In addition, a stator cooling outside air fan 39 is provided inside the other shield 4, and the outer circumferential edge of a rotor core 19 is provided with a ventilation hole 43, penetrating the edge in the axial direction. Outside air, sucked in through a ventilation inlet hole 42, is passed through the ventilation hole 43 by the stator cooling outside air fan 39 to cool the stator 1, so that the air is discharged to the exterior of the motor. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fully closed electric motor particularly suitable for driving a vehicle.

  In general, a railway vehicle is a system in which a vehicle driving motor is mounted on a carriage disposed under the floor of a vehicle body and the vehicle travels by transmitting the rotational force of the motor to wheels via a gear device. Since the vehicle driving motor is mounted on a carriage, it is required to be as small as possible, and since it is disposed under the floor with much dust, the interior is required to have a structure that is not easily polluted.

  FIG. 7 is an upper half longitudinal sectional view showing an example of a conventional open type vehicle drive motor. In FIG. 7, a rotor 6 is accommodated in an outer cover 5 including an outer frame 2 to which the stator 1 is attached and shields 3 and 4 that block both ends of the outer frame 2. Both ends of the rotor shaft 9 are supported by bearings 7 and 8 held by the bearing 4. An intake air filter 10 is provided at one upper end of the outer frame 2, and an internal air fan 11 for circulating the internal air (inside air) of the outer casing 5 is attached to the drive side of the rotor shaft 9. In the iron core 12 of the rotor 6, a plurality of air holes 13 having a circular cross section penetrating in the axial direction are arranged in an annular shape at an equal pitch as shown in FIG. 9. FIG. 10 shows a conventional stator core 19. When the electric motor is operated, the outside air sucked from the intake air filter 10 by the inside air fan 11 flows through the inside of the machine as indicated by the arrows in the figure, and cools the stator 1 and the rotor 6.

FIG. 8 is an upper half longitudinal sectional view showing an example of a conventional fully-enclosed fan-type vehicle driving motor. In FIG. 8, the outer jacket 5 is sealed, and an outside air fan 14 that vents air outside the outer jacket 5 (outside air) to the outer peripheral surface of the outer frame 2 is attached to the shaft end of the rotor shaft 9 on the non-driving side. ing. The outside air fan 14 is covered with a cup-shaped fan cover 15, and a plurality of ventilation inlet holes 16 are annularly arranged in the fan cover 15. When the electric motor is operated, the outside air sucked from the ventilation inlet hole 16 by the outside air fan 14 is guided to the fan cover 15 and flows as shown by the arrows in the figure to cool the outer peripheral surface of the outer frame 2. As a result, the stator 1 and the rotor 6 are indirectly cooled via the outer frame 2. Such a fully-enclosed fan-type vehicle driving motor is also described in Patent Document 1, for example.
JP 2003-143800 A

  In the open type electric motor shown in FIG. 7, outside air is sucked through the intake air filter 10 from under the dusty floor to the inside of the electric motor. In that case, if the filter of the intake filter 10 is made finer, the cleaning frequency of the intake filter 10 increases, and if the filter is made rougher, the cleaning frequency inside the electric motor increases. . On the other hand, in the fully closed outer fan type motor shown in FIG. 8, since the outer cover 5 is sealed, dust does not enter the inside of the motor, but the outer frame 2 is cooled by the outside air fan 14, and the stator 1 Further, since the rotor 6 is indirectly cooled, the cooling performance is poor, and there is a problem that the size must be increased as compared with the open type in order to suppress heat generation. When the motor becomes hot, the bearings 7 and 8 are heated directly by heat conduction from the rotor shaft 9 and indirectly through the air in the machine, reducing the grease life and reducing dust maintenance work by fully closing. The benefits of being lost.

  On the other hand, as a fully-enclosed external fan motor with improved cooling performance, a heat exchanger is mounted on the outer frame, and the outside air ventilated by the outside air fan and the inside air circulated through the sealed envelope by the inside air fan are heated. An apparatus in which heat is exchanged by an exchanger and the stator and the rotor are cooled is known, and is described, for example, in JP-A-10-66306. However, this type of totally enclosed fan-shaped electric motor is generally a large industrial machine, and a large-capacity multi-tube type is also used for the heat exchanger. Therefore, a conventional heat exchanger-equipped fully enclosed outer fan motor is not suitable for a vehicle driving motor in which a reduction in size and weight is indispensable because it is installed in a narrow space under the floor.

  SUMMARY OF THE INVENTION An object of the present invention is to reduce the size and weight of an electric motor for driving a vehicle while reducing dust intrusion and temperature rise and improving maintainability.

  In order to solve the above-mentioned problem, the invention of claim 1 is characterized in that it is rotated by a bearing held by the shield in an outer cover composed of an outer frame to which a stator is attached and a shield that closes both ends of the outer frame. A rotor that supports both ends of the child shaft is accommodated, and an inner air fan that circulates the inside air and an outside air fan that vents the outside air are attached to the rotor shaft, and the circulating inner air and the ventilated outside air are attached to the outer frame. It is assumed that a cross flow type total heat exchanger is installed as the heat exchanger. Conventionally, a multi-tubular heat exchanger generally used for an industrial fully enclosed fan-shaped electric motor has a small pressure loss but a large volume, which causes a large motor. Therefore, in the first aspect of the present invention, a cross flow type total heat exchanger that has a higher pressure loss than the multi-tube type but can be configured in a very compact manner is used as the heat exchanger. This makes it possible to reduce the size of the heat exchanger-equipped fully enclosed electric motor.

  According to a second aspect of the present invention, in the first aspect of the invention, the outside air fan is disposed inside the shield on the driving side, and a ventilation inlet hole is provided in the jacket, and suction is performed from the ventilation inlet hole by the outside air fan. The outside air is allowed to flow through the heat exchanger. In a conventional heat exchanger-equipped fully enclosed external fan motor, an external air fan is disposed outside the shield, and a fan cover is provided to cover the external air fan in order to guide the external air sucked by the external air fan to the heat exchanger. . For this reason, the outside air fan or the fan cover protrudes to the outside of the jacket, and the electric motor must be enlarged.

  Accordingly, in the invention of claim 2, an outside air fan is arranged inside the shield on the driving side, a ventilation inlet hole is provided in the shield, and the outside air is sucked from the ventilation inlet hole of the shield and guided to the heat exchanger. Like that. According to the second aspect of the present invention, the outside air fan is accommodated inside the jacket, and the sucked outside air is guided to the heat exchanger inside the shield, so that the outside air fan and the fan cover do not protrude to the outside, and the electric motor is small. become.

  According to a third aspect of the present invention, in the second aspect of the present invention, an annular air guide that divides the space forward and backward into a space formed between the outside air fan and the bearing holding portion of the drive side shield is provided. It is provided that a bypass ventilation path is formed from the ventilation inlet hole toward the rotor shaft along the bearing holding portion and then reversed to the blades of the outside air fan.

  If an outside air fan is placed inside the shield, a negative pressure is generated inside the bearing holding part of the shield, and this negative pressure causes the outside air to be sucked into the machine through the gap between the bearings, and the bearing can be contaminated by dust in the outside air. There is sex. Therefore, when there is such a danger, by forming the bypass passage according to the invention of claim 3, the suction of the outside air by the negative pressure is performed through the bypass passage, and the suction of the outside air through the bearing is suppressed. It is done.

  According to a fourth aspect of the present invention, in the second aspect of the invention, the outside air fan and the inside air fan are integrated with each other back to back. Conventionally, the inside air fan and the outside air fan are respectively installed on the inside and outside of the jacket. In the invention of claim 2, the outside air fan is arranged inside the shield. Is constructed integrally with the outside air fan back to back. Thereby, the axial space required for installation of the inside air fan and the outside air fan is reduced, and the electric motor is reduced in size.

  According to a fifth aspect of the present invention, both ends of the rotor shaft are supported by bearings held by the shield in an outer cover including an outer frame to which a stator is attached and a shield that closes both ends of the outer frame. A heat exchanger in which a rotor is accommodated, and an internal air fan that circulates the internal air and an external air fan that ventilates the external air are attached to the rotor shaft, and the circulating frame and the ventilated external air exchange heat with the outer frame The stator cooling outside air fan is attached to the rotor shaft on the inner side of the shield on the non-driving side, a ventilation inlet hole is provided in the outer jacket, and the stator core An air hole penetrating in the axial direction is provided in the outer peripheral edge, and a ventilation duct is provided between one end of the air hole and the outside air fan for cooling the stator, and between the other end of the air hole and a ventilation outlet hole provided in the outer frame. Forming After the outside air sucked from the ventilation inlet hole by the stator cooling outside air fan is caused to flow to the air hole through one of the ventilation ducts, the outside air is discharged from the ventilation outlet hole to the outside through the other duct. It is what you want to do.

  According to the fifth aspect of the present invention, not only the stator is cooled by the circulating air from the inside air fan, but also an outside air fan dedicated to the stator is provided, and the stator is directly cooled by the outside air by this outside air fan. The inside air fan is cooled by circulating inside air cooled by outside air through a heat exchanger, but the outside air fan for cooling the stator cools the outside air by directly passing it through the stator, which can greatly improve the cooling performance. it can.

  According to a sixth aspect of the present invention, in the second or fifth aspect of the present invention, the auxiliary air to exchange heat between the circulating internal air and the external air on the opposite side of the outer frame from the heat exchanger with the rotor shaft as a center. A heat exchanger is provided. By providing the auxiliary heat exchanger on the opposite side of the heat exchanger, it is possible to improve the cooling performance of the circulating internal air on the side far from the heat exchanger. Also, this auxiliary heat exchanger can be installed inside the motor mounting leg on the opposite side when the heat exchanger is mounted on the upper part of the jacket, so that the external shape of the motor by providing the auxiliary heat exchanger The expansion can be kept to a minimum.

  According to a seventh aspect of the present invention, in the fifth aspect of the present invention, the air holes of the stator core are formed by arranging a large number of small holes in an annular shape. By forming the air holes by closely concentrating the small holes, it is possible to obtain a large cross-sectional area of the air passage without impairing the mechanical strength of the stator core.

  In the invention according to claim 8, both ends of the rotor shaft are supported by bearings held by the shield in an outer cover including an outer frame to which a stator is attached and a shield that closes both ends of the outer frame. A heat exchanger in which a rotor is accommodated, and an internal air fan that circulates the internal air and an external air fan that ventilates the external air are attached to the rotor shaft, and the circulating frame and the ventilated external air exchange heat with the outer frame In the fully-closed electric motor in which is installed, the rotor iron core is provided with a cross-sectional gear-shaped air hole in the axial direction. Conventional rotor air holes generally have a circular cross section, but according to the invention of claim 8, the heat transfer area of the air holes can be increased without sacrificing the strength of the rotor core by adopting a cross-sectional gear shape. become.

  According to a ninth aspect of the invention, in the eighth aspect of the invention, an internal air inflow space communicating with the internal air fan is formed on one end side of the heat exchanger, and an internal space of the outer cover is formed on the other end side of the heat exchanger. The inside air discharged from the inside air fan returns to the inside space of the outer jacket through the inside air inflow space, the heat exchanger, and the inside air outflow space, and then the stator and the rotor. Are passed through the air gap between them and the air hole of the rotor core, and are again sucked into the inside air fan.

  In a tenth aspect of the present invention, in any one of the first to ninth aspects, the rotor shaft is made of a stainless steel material. Stainless steel has a lower thermal conductivity than carbon steel. Therefore, by using a stainless steel material for the rotor shaft, the amount of heat transmitted from the rotor and the inside air to the bearing via the rotor shaft can be reduced, and the temperature rise of the bearing can be suppressed.

  The present invention provides a fully-enclosed electric motor that exchanges heat between inside air and outside air via a heat exchanger, and can reduce the volume of the heat exchanger and reduce the size of the outside air fan and the fan cover without protruding to the outside. If the present invention is applied to a vehicular drive motor that is installed under a vehicle floor where the installation space is limited and a lot of dust is present, the effect of reducing maintenance work is great.

  FIG. 1 is a longitudinal sectional view of a fully closed motor showing an embodiment of the present invention in an induction motor. In addition, the same code | symbol shall be used for the part corresponding to a prior art example. In FIG. 1, a rotor 6 is accommodated in an outer cover 5 including an outer frame 2 to which a stator 1 is attached and shields 3 and 4 at both ends of the outer frame 2, and the rotor 6 is shields 3 and 4. Both ends of the rotor shaft 9 are supported by bearings 7 and 8 held on the shaft. The rotor shaft 9 is made of a stainless steel material having a lower thermal conductivity than carbon steel. 17 is a stator conductor and 18 is a rotor conductor. In the case of illustration, the outer frame 2 is divided into three cylindrical bodies of a driving side bracket 2a, an iron core frame 2b and a counter driving side bracket 2c in the axial direction from the right side (driving side) in FIG. A cylindrical frame is formed.

  Here, the drive-side bracket 2a and the iron core frame 2b are cylindrical bodies whose both end surfaces are substantially open. On the outer end (left end in FIG. 1) of the non-drive-side bracket 2c, a flange-shaped end plate 2d is provided. It is integrally formed. A stator core 19 is held on the iron frame 2b. Box-shaped ventilation housings 2e and 2f whose opposing surfaces are open are integrally formed on the upper side of the driving side bracket 2a and the non-driving side bracket 2c, and are cross-flowed so as to cross between the ventilation housings 2e and 2f. A plate-fin type total heat exchanger 20 is mounted. FIG. 2 is a schematic perspective view of the total heat exchanger 20, and an outside air duct 23 and an inside air duct 24 that are orthogonal to each other are formed by a partition plate 21 and a corrugated spacing plate 22.

  The drive-side shield 3 includes a conical bearing holding portion 3a and an annular edge 3b on the outer periphery thereof, and is fastened to the end surface of the outer frame 2 via the annular edge 3b. A bearing 7 is fitted into the bearing holding portion 3a and filled with grease. The shield 4 on the non-driving side includes a bearing holding portion 4a similar to that on the driving side and a slight flange 4b on the outer periphery thereof, and is fastened to the end plate 2d of the outer frame 2 via the flange 4b. A bearing 8 is fitted into the bearing holding portion 4a and filled with grease.

  An outside air fan 14 is disposed inside the drive-side shield 3 via a space 25. The outside air fan 14 includes a main plate 26 fixed to the rotor shaft 9 and a plurality of blades 27 attached to the periphery of the surface on the shield 3 side. The main plate 26 follows the surface shape of the opposing shield 3. The central portion is formed in a conical shape, and the outer peripheral surface is close to the inner peripheral surface of the outer frame 2 through a minute gap. The jacket 5 (shield 3) is provided with a plurality of ventilation inlet holes 28 arranged in an annular shape so as to communicate with the space 25. On the other hand, many blades 29 of the inside air fan 11 are attached to the surface of the main plate 26 opposite to the surface to which the blades 27 are attached. That is, the main plate 26 serves as both the outside air fan 14 and the inside air fan 11, and the blades 26 and 29 are attached to both sides thereof, so that the inside air fan 11 and the outside air fan 14 are integrally formed back to back. Reference numeral 30 denotes a side plate connecting the blades 29 together.

  Here, FIG. 3 is a partial cross-sectional view taken along line III-III in FIG. In FIG. 1 and FIG. 3, the lateral width (vertical width in FIG. 1) of the total heat exchanger 20 is arranged on the outer peripheral wall upper part of the outer frame 2 (drive side bracket 2 a) so as to face the outer peripheral surface of the internal air fan 11. A ventilation port 31 having the same width is opened, and a ventilation port 32 is opened adjacent to the ventilation port 31 in the axial direction so as to face the outer peripheral surface of the outside air fan 14. In the ventilation housing 2e of the outer frame 2, a partition wall 2g that partitions the ventilation ports 31 and 32 in the axial direction is integrally formed.

  The partition wall 2 g forms an outside air inflow space 33 and an inside air inflow space 34 on the right end side of the total heat exchanger 20 in FIG. 1, and the outside air inflow space 33 is connected to the outside air fan 14 through the ventilation port 32. The inside air inflow space 34 communicates with the inside air fan 11 through the ventilation port 31. Further, an inside air outflow space 35 is formed on the left end side of the total heat exchanger 20 in FIG. 1, and this inside air outflow space 35 has a ventilation port 36 opened in the outer peripheral wall of the outer frame 2 (counter drive side bracket 2c). Through the inner space of the outer jacket 5. Further, as shown in FIG. 3, an outside air inflow duct 37 that leads to the outside air inflow space 33 is formed on the outside air inflow side of the total heat exchanger 20 by the ventilation housings 2e and 2f.

  In FIG. 1, a stator cooling outside air fan 39 is disposed inside a shield 4 on the counter driving side via a space 38. The stator cooling outside air fan 39 includes a main plate 40 fixed to the rotor shaft 9 and a plurality of blades 41 attached to the periphery on the shield 4 side. The main plate 40 follows the surface shape of the opposing shield 4. It is formed in a conical shape. The jacket 5 is provided with a plurality of ventilation inlet holes 42 arranged in an annular shape communicating with the space 38 so as to penetrate the end plate 2d of the non-driving side bracket 2c and the flange 4b of the shield 4. .

  An air hole 43 penetrating in the axial direction is provided on the outer peripheral edge of the stator core 19. As shown in FIG. 5, the air holes 43 are formed by arranging a large number of oval small holes in an annular shape. A ventilation duct 44 is formed between one end (the left end in FIG. 1) of the air hole 43 and the outside air fan 39 for cooling the stator. The ventilation duct 44 includes an annular space 44 a that surrounds the outer peripheral surface of the stator cooling outside air fan 39, an annular space 44 b that contacts the left end surface of the stator core 19 in FIG. 1, and annular spaces 44 a and 44 b at the bottom of the outer frame 2. It has a cylindrical space 44c having a square cross section that communicates with each other, and any of the spaces 44a to 44c is partitioned by a ventilation guide wall of the illustrated shape integrally with the non-driving side bracket 2c.

  On the other hand, a ventilation outlet hole 45 is provided at the bottom of the outer frame 2, and a ventilation duct 46 is formed between the other end of the air hole 43 (the right end in FIG. 1) and the ventilation outlet hole 45. The ventilation duct 46 includes an annular space 46 a in contact with the right end surface of the stator core 19 in FIG. 1 and a box-shaped space 46 b having a square cross section that connects the annular space 46 a and the ventilation outlet hole 45 at the bottom of the outer frame 2. Yes.

  In FIG. 1, an auxiliary heat exchanger 47 is provided on the opposite side of the outer frame 2 from the total heat exchanger 20 around the rotor shaft 9. The auxiliary heat exchanger 47 is a finned tube heat exchanger, and both ends are connected to a pair of front and rear box-shaped ducts 48 and 49 attached to the outer side of the bottom of the outer frame 2, and the outer surface is exposed to the outside air. . The duct 48 faces the outer peripheral surface of the inside air fan 11 through the ventilation inlet hole 50 opened in the outer frame 2 (drive side bracket 2a), and the duct 49 avoids the ventilation duct 44 and the outer frame 2 (counter drive side bracket 2c). The inside of the jacket 5 is communicated through a ventilation inlet hole 51 opened in the air.

  Next, the flow of cooling air when the electric motor shown in FIG. 1 is operated will be described. First, the inside air discharged from the inside air fan 11 flows along the route of the vent 31 → the inside air inflow space 34 → the inside air duct 24 of the total heat exchanger 20 → the inside air outflow space 35, as indicated by a broken line arrow, and the jacket 5. Returning to the internal space, the air is circulated through the air gap between the stator 1 and the rotor 6 and the air hole 13 of the rotor core 12 and again sucked into the inside air fan 11. Here, FIG. 4 shows the shape of the air hole 13 opened in the rotor core 12, and has a gear shape as shown. The conventional rotor air hole 13 is generally circular in cross section as shown in FIG. 9, but by forming a cross-sectional gear shape as shown in FIG. 4, the heat of the air hole 13 without impairing the strength of the rotor core 12. It becomes possible to increase the transmission area.

  The outside air sucked from the ventilation inlet hole 28 by the outside air fan 14 is, as indicated by a solid arrow, the ventilation port 32 → the outside air inflow space 33 → the outside air inflow duct 37 (see FIG. 2) → the outside air duct 23 of the total heat exchanger 20. It is ventilated by the route of and is discharged out of the machine. The ventilation outside air exchanges heat with the circulating inside air passing through the inside air duct 24 of the total heat exchanger 20 to cool the circulating inside air.

  In the conventional fully-enclosed external fan motor, the outside air fan is disposed outside the shield. However, in the motor shown in FIG. 1, the outside air fan 14 is disposed inside the shield 3, and the outside air sucked from the ventilation inlet hole 28 of the shield 3. Is guided to the heat exchanger through the inner space 25 of the outer jacket 5. Therefore, the outside air fan and the fan cover do not protrude outside, and the electric motor is miniaturized. Further, in the electric motor of FIG. 1, the inside air fan 11 and the outside air fan 14 are integrally formed back to back. As a result, the axial space required for installation of the inside air fan 11 and the outside air fan 14 is reduced, and the electric motor is further downsized.

  Here, in FIG. 1, an annular air guide 53 made of a steel plate that divides the space 52 in the front-rear direction (axial direction) into a space 52 formed between the outside air fan 14 and the bearing holding portion 3 a of the shield 3. Is provided. In the case of illustration, the air guide 53 is formed in a conical shape along the conical shape of the bearing holding portion 3a, and its upper end is coupled to the bearing holding portion 3a by, for example, welding so as to cover a part of the ventilation inlet hole 28. . This air guide 53 passes through the ventilation inlet hole 28 in the space 52 along the bearing holding portion 3a toward the rotor shaft 9 and then reverses toward the blade 27 of the outside air fan 14 (indicated by an arrow). 54 is formed.

  When the outside air fan 14 is disposed inside the shield 3, a negative pressure is generated inside the bearing holding portion 3 a of the shield 3, and the outside air is sucked into the machine through the gap of the bearing 7 due to the negative pressure, and the bearing 7 is in the outside air. There is a possibility of being polluted with dust. In that case, by forming the bypass passage 54, the outside air is sucked by the negative pressure inside the bearing holding portion 3 a through the bypass passage 54 having a smaller ventilation resistance than the bearing 7, and the outside air is sucked through the bearing 7. Is suppressed. Further, since a part of the sucked outside air flows in the space 52 along the bearing holding portion 3a, the bearing 7 is cooled by the outside air. An air guide 55 similar to the air guide 53 is also provided on the non-driving side. The air guide 55 bypasses part of the outside air sucked from the ventilation inlet hole 42 by the stator cooling outside air fan 39, and the configuration and action thereof are the same as those of the air guide 53.

  The outside air sucked from the ventilation inlet hole 42 by the stator cooling outside air fan 39 flows through the ventilation duct 44 (space 44a → 44c → 44b) into the air hole 43 of the stator core 19, and then the ventilation duct 46 (space 46a). → It is discharged out of the machine through the vent hole 45 of the outer frame 2 through 46b). Not only the stator 1 is cooled by the internal air fan 11 but also the external air fan 39 dedicated to the stator is provided, and the stator 1 is directly cooled by the external air by the external air fan 39, so that the cooling performance is greatly improved. In that case, as shown in FIG. 5, by forming the air holes 43 by densely forming a large number of small holes 43 a in an annular shape, the cross-sectional area of the air passage can be increased without impairing the mechanical strength of the stator core 19.

  In FIG. 1, a part of the inside air circulated in the machine by the inside air fan 11 is a route of the ventilation inlet hole 50 → the ventilation duct 48 → the auxiliary heat exchanger 47 → the ventilation duct 49 → the ventilation inlet hole 51, as indicated by broken line arrows. It passes through the auxiliary heat exchanger 47 and exchanges heat with the outside air. By providing the auxiliary heat exchanger 47 in addition to the total heat exchanger 20, the cooling performance of the circulating internal air on the opposite side of the total heat exchanger 20 is improved, and the local heating of the electric motor on the side far from the total heat exchanger 20 is improved. Is prevented.

  In the electric motor of FIG. 1, a stainless steel material having a low thermal conductivity is used for the rotor shaft 9. As a result, the amount of heat transferred from the rotor 6 and the inside air to the bearings 7 and 8 via the rotor shaft 9 is reduced, and the temperature rise of the bearings 7 and 8 is suppressed.

  FIG. 6 is a longitudinal sectional view showing an embodiment of the present invention in a permanent magnet type synchronous motor. In FIG. 6, a permanent magnet 56 is mounted on the outer peripheral portion of the rotor 6. However, the cooling structure is substantially the same as that of the induction motor of FIG.

It is a longitudinal cross-sectional view of the electric motor which shows embodiment of this invention. It is a perspective view of the total heat exchanger in FIG. It is a fragmentary sectional view which follows the III-III line of FIG. It is a front view of the rotor core in FIG. It is a front view of the stator core in FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention in a permanent magnet type synchronous motor. It is the upper half longitudinal cross-sectional view of the electric motor which shows a prior art example. It is the upper half longitudinal cross-sectional view of the electric motor which shows a different prior art example. It is a front view of the rotor core in the conventional electric motor. It is a front view of the stator core in the conventional electric motor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stator 2 Outer frame 3 Drive side shield 4 Counter drive side shield 5 Outer cover 6 Rotor 7 Bearing 8 Bearing 9 Rotor shaft 11 Inside air fan 13 Rotor air hole 14 Outside air fan 20 Total heat exchanger 39 Outside air for stator cooling Fan 43 Stator air hole 44 Ventilation duct 46 Ventilation duct 47 Auxiliary heat exchanger 53 Air guide 54 Bypass air passage 55 Air guide

Claims (10)

A rotor having both ends of a rotor shaft supported by bearings held by the shield is housed in an outer cover formed of an outer frame to which a stator is attached and a shield that closes both ends of the outer frame. A fully enclosed electric motor in which an internal air fan that circulates internal air and an external air fan that ventilates the external air are attached to the rotor shaft, and a heat exchanger that exchanges heat between the circulating internal air and the ventilated external air is mounted on the outer frame In
A fully-closed electric motor in which a cross flow type total heat exchanger is installed as the heat exchanger.   The outside air fan is arranged inside the shield on the driving side, and a ventilation inlet hole is provided in the jacket, so that the outside air sucked by the outside air fan from the ventilation inlet hole is passed through the heat exchanger. The fully-closed electric motor according to claim 1, wherein:   An annular air guide is provided in a space formed between the outside air fan and the bearing holding portion of the drive-side shield so as to divide the space forward and backward, and extends from the ventilation inlet hole along the bearing holding portion. The fully-closed electric motor according to claim 2, wherein a bypass ventilation path is formed toward the rotor shaft side and then reversed to the blades of the outside air fan.   The fully-closed electric motor according to claim 2, wherein the inside air fan is integrated with the outside air fan back to back. A rotor having both ends of a rotor shaft supported by bearings held by the shield is housed in an outer cover formed of an outer frame to which a stator is attached and a shield that closes both ends of the outer frame. A fully enclosed electric motor in which an internal air fan that circulates internal air and an external air fan that ventilates the outside air are attached to the rotor shaft, and a heat exchanger that exchanges heat between the circulating internal air and the ventilated external air is mounted on the outer frame In
A stator cooling outside air fan is attached to the rotor shaft inside the shield on the non-driving side, and a ventilation hole is provided in the outer jacket, and an air hole penetrating in the axial direction on the outer peripheral edge of the stator core A ventilation duct is formed between one end of the air hole and the outside air fan for cooling the stator and between the other end of the air hole and a ventilation outlet hole provided in the outer frame, After the outside air sucked from the ventilation inlet hole by the outside air fan is allowed to flow through the ventilation duct to the ventilation hole, the outside air is discharged from the ventilation outlet hole to the outside through the other duct. A fully enclosed motor.   The auxiliary heat exchanger for exchanging heat between the circulating internal air and the external air is provided on the opposite side of the outer frame from the heat exchanger with the rotor shaft as a center. Fully enclosed motor as described.   6. The fully-closed electric motor according to claim 5, wherein a number of small holes are annularly arranged to form a wind hole of the stator core. A rotor having both ends of a rotor shaft supported by bearings held by the shield is housed in an outer cover made up of an outer frame to which a stator is attached and a shield that closes both ends of the outer frame. A fully enclosed electric motor in which an internal air fan that circulates internal air and an external air fan that ventilates the outside air are attached to the rotor shaft, and a heat exchanger that exchanges heat between the circulating internal air and the ventilated external air is mounted on the outer frame In
A fully-enclosed electric motor characterized in that an air hole having a gear section in the axial direction is provided in a rotor iron core.   An inside air inflow space that communicates with the inside air fan is formed on one end side of the heat exchanger, and an inside air outflow space that communicates with the inner space of the jacket is formed on the other end side of the heat exchanger, and is discharged from the inside air fan. The returned inside air returns to the inner space of the outer jacket through the path of the inside air inflow space, the heat exchanger, and the inside air outflow space, and then passes through the air gap between the stator and the rotor and the air hole of the rotor core. The fully-closed electric motor according to claim 8, wherein the fully-closed electric motor passes through and is sucked into the inside air fan again.   The fully-closed electric motor according to claim 1, wherein the rotor shaft is made of a stainless steel material.

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