An Adaptive Self-Ventilated Evaporative Cooling System for a Totally Enclosed Permanent Magnet Motor

Abstract

The present invention relates to the technical field of heat dissipation of permanent magnet motors, and particularly to a fully enclosed permanent magnet motor adaptive self-ventilation evaporation cooling system, which solves the heat dissipation problem of fully enclosed motors under large loads and harsh working conditions. It includes a condenser and a sealed cavity composed of a motor stator core, end covers at both ends, a coil winding, and a casing. A cooling working medium is filled in the sealed cavity. One end of the condenser is provided with a cooling working medium buffer cavity, and the other end is provided with a cooling working medium concentration cavity. A condensation tube is arranged in the condenser. A through hole that is hermetically docked with the cooling working medium buffer cavity is opened on the casing at the top of the motor. The cooling working medium concentration cavity is provided with a cooling working medium outlet for communicating with the sealed cavity. A cooling fan is connected to the non-driving end rotating shaft of the motor, and a fan protective cover is arranged outside the cooling fan. The fan protective cover, the non-driving end cover, the casing, and the bottom of the condenser form a cooling air passage. An air inlet is arranged at the bottom of the condenser, and an air outlet is opened at the upper part of the condenser.

Description

Technical Field

[0001] The present invention relates to the technical field of heat dissipation of permanent magnet motors, and particularly to an adaptive self-ventilated evaporative cooling system for a fully enclosed permanent magnet motor. Background Art

[0002] To ensure the safe operation of permanent magnet motors, the motors usually adopt a fully enclosed structure to improve their reliability, reduce the maintenance workload and lower the noise. However, it is very difficult to quickly dissipate the heat inside the motor with a fully enclosed structure, resulting in a reduction in the heat dissipation efficiency of the motor and an increase in the temperature rise. Long-term operation at high temperatures will reduce the service life of the motor and even cause safety problems. The temperature rise problem of fully enclosed motors with high speed, high torque density, high power density and compact structure is particularly prominent. Therefore, to ensure the long-term safe operation of the motor, it is particularly important to design an efficient cooling system to reduce the temperature rise of fully enclosed motors.

[0003] There are two common ventilation and cooling methods for fully enclosed motors: one is to cool through the heat dissipation ribs on the outer surface of the motor housing. The heat is conducted from the stator core of the motor to the housing and then to the air through the heat dissipation ribs on the housing. The heat dissipation ribs on the housing increase the heat dissipation area and are beneficial to the heat dissipation of the motor. However, it is difficult to completely fit the outer circle of the stator core and the inner circle of the housing, resulting in a large thermal conduction resistance and poor overall heat dissipation capacity of the motor, which is not suitable for permanent magnet motors with high power density. The other is that the cooling air forms a duct through the ventilation holes on the front and rear end covers of the motor and the ventilation holes inside the housing to take away the heat of the motor to achieve ventilation and cooling. However, the cooling air does not circulate inside the motor, and it is impossible to avoid a large temperature rise inside the motor. This cooling structure is also not suitable for fully enclosed motors.

[0004] Chinese Patent CN1960126A proposes a stator structure of an evaporative cooling wind turbine generator. In this patent, the condenser is directly arranged above the motor, but the cold source of the condenser does not pass through the inside of the motor. Chinese Patent CN209184415U proposes a full-liquid evaporative cooling system for motor cooling. However, in this cooling solution, the motor and the condenser are still designed separately, and the entire system occupies a large space. Chinese Patent CN216564682U proposes a fully enclosed double-cycle air-cooled motor structure, and two cooling medium passages are arranged inside the motor. However, this cooling solution transfers the heat to the motor through the internal circulating air and then to the housing through the external circulating air, which belongs to indirect cooling.

[0005] Therefore, how to provide a heat dissipation system suitable for fully enclosed permanent magnet motors is a technical problem to be solved in this field. Summary of the Invention

[0006] To overcome the heat dissipation problem of a fully enclosed motor with high rotational speed, high torque density, high power density, and a compact structure under large loads and harsh working conditions, the present invention provides an adaptive self-ventilated evaporative cooling system for a fully enclosed permanent magnet motor.

[0007] The present invention provides an adaptive self-ventilated evaporative cooling system for a fully enclosed permanent magnet motor, comprising: a condenser and a sealed cavity jointly formed by a motor stator core, a non-drive end cover, a drive end cover, a coil winding, and a housing. A cooling working medium is contained in the sealed cavity. A circle of through holes evenly distributed along the circumference is provided on the motor stator core. After the through holes of adjacent stator cores are aligned, a cooling working medium channel is formed. One end of the condenser is provided with a cooling working medium buffer cavity, and the other end is provided with a cooling working medium concentration cavity. A plurality of condensing tubes with one end communicating with the cooling working medium buffer cavity and the other end communicating with the cooling working medium concentration cavity are arranged in the condenser. A through hole for sealing connection with the cooling working medium buffer cavity is opened on the housing at the top of the motor. The cooling working medium concentration cavity is provided with a cooling working medium outlet for communicating with the sealed cavity. A cooling fan is also connected to the non-drive end shaft of the motor. A fan protective cover is provided outside the cooling fan. The fan protective cover, the non-drive end cover, the motor stator core, and the bottom of the condenser jointly form a cooling air channel. A plurality of air inlets communicating with the cooling air channel are also provided at the bottom of the condenser, and a plurality of air outlets are opened at the upper part of the condenser.

[0008] The object of the present invention is to overcome the limitations of the existing cooling methods for fully enclosed motors, and provide an adaptive self-ventilated evaporative cooling system for a fully enclosed permanent magnet motor, realizing the integrated design of the motor and the evaporative cooling system. The condenser is installed on the top of the motor. The cold source of the condenser comes from the cooling fan driven by the shaft. After the cooling fan sucks cold air from the outside, the cold air is sent into the condenser through the air inlets along the cooling air channel. The shape of the through holes on the motor stator core can be round holes, square holes, or waist-shaped holes, and the formed cooling working medium channels are correspondingly circular, square, or waist-shaped. The cooling working medium buffer cavity and the cooling working medium concentration cavity are respectively located at both ends of the condensing tube. The condenser communicates with the sealed cavity of the motor through the cooling working medium buffer cavity. The cooling working medium can circulate in the cooling working medium channels on the motor stator core, thereby taking away the heat of the motor stator core and the winding. The evaporated cooling working medium enters the condensing tube from the cooling working medium buffer cavity. During the process of passing through the condensing tube, the cooling working medium is cooled and liquefied and flows into the cooling working medium concentration cavity, and then returns to the sealed cavity from the cooling working medium outlet of the cooling working medium concentration cavity. By designing the cooling working medium circulation path and the cooling air channel, both the cooling working medium circulation volume and the cooling air volume are self-matched according to the motor working conditions, improving the self-adaptability of the cooling system. Therefore, while realizing efficient cooling of the fully enclosed motor, the present invention has the advantages of energy conservation and reduction of the installation space of the evaporative cooling type fully enclosed motor.

[0009] Preferably, the condenser tube is inclined downward by 2-5° from the cooling working medium buffer chamber to the cooling working medium concentration chamber. This is to prevent the condensed cooling working medium from flowing back and has a guiding effect on the flow of the cooling working medium.

[0010] Preferably, the outer wall of the condenser tube is provided with a fin structure for enhancing heat dissipation. The fin structure can increase the heat dissipation area and thus enhance the heat dissipation effect of the condenser tube.

[0011] Preferably, the condenser tubes are arranged in a multi-row and multi-column form. This is to play a guiding role in the flow of the cooling working medium.

[0012] Preferably, the air inlet is divided into a large air inlet and a small air inlet for balancing the wind pressure resistance.

[0013] Preferably, the air outlet is arranged on the front side wall and the rear side wall of the condenser.

[0014] The technical solution provided by the present invention has the following advantages compared with the prior art: This evaporation cooling system adopts the stator full-immersion evaporation cooling method to directly cool the stator and the winding; the cold source of the condenser is provided by a cooling fan driven by the rotating shaft to realize the self-ventilation of the motor. The condenser is directly installed on the upper side of the motor, and the cooling air inlet is located below the condenser. While cooling the condenser, the cooling air will also accelerate the heat dissipation of the machine base, realizing the combination of air cooling and evaporation cooling. The cooling working medium circulation volume and the cooling air volume are adaptively matched with the motor working conditions.

[0015] The present invention relates to an integrated design of an adaptive self-ventilation evaporation cooling system for a fully enclosed permanent magnet traction motor applied in the rail transit field. The present invention mainly solves the heat dissipation problems of high-speed, high-torque density, high-power density and structurally compact fully enclosed motors under large loads and harsh working conditions; while realizing efficient cooling of the motor, this cooling system improves the self-adaptability of the cooling system, enhances the integrity of the motor, realizes the integrated design of the motor and the evaporation cooling system, and the entire cooling circulation system does not require an additional pump circulation system. The self-circulation power is generated by the endothermic evaporation of the cooling working medium, and the heat dissipation efficiency is adaptively matched according to the motor working conditions. The greater the motor load, the greater the working medium circulation volume. The present invention efficiently cools the fully enclosed permanent magnet motor through the adaptive self-ventilation evaporation cooling system, solving the heat dissipation problems of the fully enclosed permanent magnet motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings herein are incorporated into the specification and form a part of the specification, showing embodiments consistent with the present invention and, together with the specification, are used to explain the principles of the present invention.

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0018] Figure 1 It is a schematic structural diagram of a fully enclosed permanent magnet motor adaptive self-ventilation evaporation cooling system according to an embodiment of the present invention;

[0019] Figure 2 It is a schematic structural diagram of the condenser according to an embodiment of the present invention;

[0020] Figure 3 It is a schematic diagram of the motor stator core according to an embodiment of the present invention;

[0021] Figure 4 It is a schematic diagram of the motor stator core according to another embodiment of the present invention.

[0022] Wherein: 10, cooling fan; 20, fan protection cover; 30, non-drive end cover; 40, condenser; 50, condenser air duct; 60, motor stator core; 70, coil winding; 80, drive end cover; 90, machine shell; 401, cooling working medium outlet; 402, air outlet; 403, condensation pipe, 404, cooling working medium concentration chamber; 405, cooling working medium buffer chamber; 406, air inlet; 601, cooling working medium channel. Detailed implementation manners

[0023] In order to be able to more clearly understand the above objects, features and advantages of the present invention, the following will further describe the solutions of the present invention. It should be noted that, without conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0024] Many specific details are set forth in the following description in order to fully understand the present invention, but the present invention can also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only part of the embodiments of the present invention, rather than all the embodiments.

[0025] Embodiments of the present invention provide a fully enclosed permanent magnet motor adaptive self-ventilation evaporation cooling system, as Figures 1 - 4As shown in the figure, it includes: a condenser 40 and a sealed cavity jointly composed of a motor stator core 60, a non-driving end cover 30, a driving end cover 80, a coil winding 70 and a machine housing 90. A cooling working medium is filled in the sealed cavity. A circle of through holes evenly distributed along the circumferential direction are arranged on the motor stator core 60. After the through holes of adjacent stator cores are aligned, a cooling working medium channel 601 is formed; One end of the condenser 40 is provided with a cooling working medium buffer cavity 405, and the other end is provided with a cooling working medium concentration cavity 404. A plurality of condenser tubes 403 are arranged in the condenser 40, one end of which is communicated with the cooling working medium buffer cavity 405 and the other end is communicated with the cooling working medium concentration cavity 404. A through hole for sealing connection with the cooling working medium buffer cavity 405 is opened on the machine housing 90 at the top of the motor. The cooling working medium concentration cavity 404 is provided with a cooling working medium outlet 401 for communicating with the sealed cavity; A cooling fan 10 is also connected to the non-driving end shaft of the motor. A fan protection cover 20 is arranged outside the cooling fan 10. The bottom of the fan protection cover 20, the non-driving end cover 30, the motor stator core 60 and the condenser 40 jointly form a cooling air channel. The bottom of the condenser 40 is also provided with a plurality of air inlets 406 communicated with the cooling air channel, and a plurality of air outlets 402 are opened on the upper part of the condenser 40.

[0026] The object of the present invention is to overcome the limitations of the existing cooling methods for fully enclosed motors, and provide an adaptive self-ventilated evaporative cooling system for a fully enclosed permanent magnet motor, realizing the integrated design of the motor and the evaporative cooling system. The condenser 40 is installed on the top of the motor. The cold source of the condenser 40 comes from the cooling fan 10 driven by the rotating shaft. After the cooling fan 10 sucks in the cold air from the outside, the cold air is sent into the condenser 40 through the air inlet 406 along the cooling air channel. The shape of the through holes on the motor stator core can be circular holes, square holes or kidney-shaped holes, and accordingly, the formed cooling working medium channels 601 are also circular, square or kidney-shaped. The cooling working medium buffer cavity 405 and the cooling working medium concentration cavity 404 are respectively located at both ends of the condensing tube 403. The condenser 40 communicates with the sealed cavity of the motor through the cooling working medium buffer cavity 405. The cooling working medium can circulate in the cooling working medium channels 601 on the motor stator core, thereby taking away the heat of the motor stator core and windings. The evaporated cooling working medium enters the condensing tube 403 from the cooling working medium buffer cavity 405. When passing through the condensing tube 403, the cooling working medium is cooled and liquefied and flows into the cooling working medium concentration cavity 404, and then flows back to the sealed cavity from the cooling working medium outlet 401 of the cooling working medium concentration cavity 404. By designing the cooling working medium circulation path and the cooling air channel, both the circulation amount of the cooling working medium and the air volume of the cooling air are adaptively matched according to the motor operating conditions, improving the self-adaptability of the cooling system. Therefore, while achieving efficient cooling of the fully enclosed motor, the present invention has the advantages of saving energy and reducing the installation space of the evaporative cooling type fully enclosed motor. In specific implementation, the air inlet 406 and the air outlet 402 can be set to one or more. The cooling fan 10 can be a welded part or an aluminum casting, and the cooling fan 10 can be installed at the driving end or the non-driving end of the motor as required. The motor stator core 60 is laminated by thin silicon steel, and the cross-sectional shape of the motor stator core 60 can be designed into a circular shape or a polygon according to requirements. As is well known to those skilled in the art, a driving end cover 80 is provided at one end of the motor, and a non-driving end cover 30 and a fan protection cover 20 are provided at the other end. The condenser 40 includes the internal condensing tube 403 and the external condenser air hood 50. The air inlet 406 and the air outlet 402 are both arranged on the condenser air hood 50, and the condenser air hood 50 is hermetically connected to the motor housing 90.

[0027] Further, the condensing tube 403 is inclined downward by 2-5° in the direction from the cooling working medium buffer cavity 405 to the cooling working medium concentration cavity 404. This is to prevent the condensed cooling working medium from flowing back and has a guiding effect on the flow of the cooling working medium.

[0028] Further, the outer wall of the condensing tube 403 is provided with a fin structure for enhancing heat dissipation. The fin structure can increase the heat dissipation area, thereby enhancing the heat dissipation effect of the condensing tube 403.

[0029] Further, the condenser tubes 403 are arranged in a multi-row and multi-column form. This is to play a role in guiding the flow of the cooling working fluid.

[0030] Further, the air inlet 406 is divided into a large air inlet 406 and a small air inlet 406, which are used to balance the wind pressure resistance.

[0031] Further, the air outlets 402 are arranged on the front side wall and the rear side wall of the condenser 40.

[0032] The above are only specific embodiments of the present invention, which enable those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments described herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An adaptive self-ventilated evaporative cooling system for a fully enclosed permanent magnet motor, characterized in that, Comprising: A condenser (40) and a sealed cavity jointly formed by a motor stator core (60), a non-drive end cover (30), a drive end cover (80), a coil winding (70), and a housing (90). The sealed cavity is filled with a cooling working medium. A circle of through holes evenly distributed along the circumference is provided on the motor stator core (60). After the through holes of adjacent stator cores are aligned, a cooling working medium channel (601) is formed; One end of the condenser (40) is provided with a cooling working medium buffer cavity (405), and the other end is provided with a cooling working medium concentration cavity (404). A plurality of condensing tubes (403) are arranged in the condenser (40), one end of which is connected to the cooling working medium buffer cavity (405) and the other end is connected to the cooling working medium concentration cavity (404). A through hole hermetically docked with the cooling working medium buffer cavity (405) is opened on the housing (90) at the top of the motor. The cooling working medium concentration cavity (404) is provided with a cooling working medium outlet (401) for communicating with the sealed cavity; A cooling fan (10) is also connected to the non-drive end shaft of the motor. A fan protection cover (20) is provided outside the cooling fan (10). The bottom of the fan protection cover (20), the non-drive end cover (30), the motor stator core (60), and the condenser (40) jointly form a cooling air channel. A plurality of air inlets (406) communicating with the cooling air channel are also provided at the bottom of the condenser (40). A plurality of air outlets (402) are opened at the upper part of the condenser (40).

2. The self - adaptive self - ventilated evaporation cooling system for a fully enclosed permanent magnet motor according to claim 1, wherein, The condensing tube (403) is inclined downward by 2 - 5° in the direction from the cooling working medium buffer cavity (405) to the cooling working medium concentration cavity (404).

3. The self - adaptive self - ventilated evaporation cooling system for a fully enclosed permanent magnet motor according to claim 2, wherein The outer wall of the condensing tube (403) is provided with a fin structure for enhancing heat dissipation.

4. The self - adaptive self - ventilated evaporative cooling system for a fully - enclosed permanent - magnet motor according to claim 3, characterized in that, The condensing tubes (403) are arranged in a multi-row and multi-column form.

5. An adaptive self-ventilated evaporative cooling system for a fully enclosed permanent magnet motor according to claim 4, characterized in that, The air inlets (406) are divided into large air inlets (406) and small air inlets (406) for balancing the wind pressure resistance.

6. An adaptive self-ventilated evaporation cooling system for a fully enclosed permanent magnet motor according to claim 5, characterized in that, The air outlets (402) are arranged on the front side wall and the rear side wall of the condenser (40).

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