Patent Publication Number: US-2022239195-A1

Title: Cooling system, electric motor and wind-power electric generator set

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a National Stage of International Application No. PCT/CN2020/078408, filed Mar. 9, 2020, which claims priority to and the benefit of Chinese Patent Application No. 201910364164.5, filed Apr. 30, 2019, the entireties of which are hereby incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to a technical filed of cooling, and particularly relates to a cooling system, an electric motor and a wind-power electric generator set. 
     BACKGROUND 
     Wind power is one of the renewable energy technologies closest to commercialization, and is the focus of renewable energy development. A electric motor in a wind-power electric generator set has the heat loss during operation, in which the heat loss mainly includes: the electromagnetic loss, that is, the Joule heat generated by the ohmic impedance in a winding set, that is, the copper loss; the hysteresis loss, the eddy current loss and the like in an iron core, that is, the iron loss; and the inevitable stray loss; if the electric motor is a permanent magnet electric motor, it further includes the magnetic steel loss. Because of these losses cause, the electric motor releases a large amount of heat when is working, and the heat will not only cause a certain impact on the electric motor itself and a insulation structure of the electric motor, which can lead to the shortened insulation life and even insulation failure, but also cause the output power of the electric motor to continue to be reduced. 
     With the rapid development of an offshore wind-power electric generator set, a unit generator capacity of the set continues to increase, which directly leads to the losses of the wind-power electric generator set continuously increasing, and a cooling system of the electric motor will occupy more space in a nacelle. For working conditions with heavy sandstorms or harsh working environments, especially for marine salt fog environments, an air-to-air cooling system is likely to cause dust accumulation in the electric generator and the cooling air volume of the system decreasing, resulting in the insufficient heat dissipation, and at the same time, it is more likely to cause damage and failure to components and members, and reduce the life of the whole machine; adopting a water-cooling system, in order to ensure the temperature limitation of the winding set, the temperature rise requirements and the temperature uniformity, it is bound to produce too many loops and joints in the electric motor; at the same time, a compact flow channel increases the resistance of the system and increases the self-consumption; considering the cooling of the ends and the rotor of the winding set, an air cooling system needs to be configured independently, resulting in a complicated structure of the cooling system and the reduced reliability. 
     SUMMARY 
     The object of the present disclosure is to provide a cooling system, an electric motor and a wind-power electric generator set, and an overall structure of the cooling system is simple and compact, and occupies smaller space. 
     In one aspect, a cooling system applied to an electric motor is provided by the present disclosure; the electric motor includes a stator support and a rotor support, the stator support is dynamically sealingly connected to the rotor support to form ventilation chambers respectively arranged at two ends of the electric motor in an axial direction, first ventilation holes are formed at two ends of the stator support in the axial direction respectively, and the cooling system includes a flow-confluence chamber, arranged in a circumferential direction of the stator support; an accommodating chamber, arranged in the circumferential direction of the stator support; in which the accommodating chamber is located at an inner side of the flow-confluence chamber in a radial direction and communicates with the flow-confluence chamber, and the first ventilation holes are located outside the accommodating chamber; a heat exchanger, arranged in the accommodating chamber or the flow-confluence chamber; a circulating fan, arranged in the circumferential direction of the stator support and located at a side of the stator support in the axial direction, wherein the circulating fan has an air inlet and an air outlet; herein, after cooling air flows out of the air outlet of the circulating fan, a part of the cooling air enters one end of the ventilation chamber which is closer; the other part of the cooling air enters the other end of the ventilation chamber through the first ventilation holes, which are respectively formed at the two ends of the stator support in the axial direction, the two parts of the cooling air flow over a heat-generating member in the electric motor, and then enters the air inlet of the circulating fan via the flow-confluence chamber, the heat exchanger and the accommodating chamber. 
     In another aspect, an electric motor is provided by the present disclosure, including any one of the cooling systems as described above. 
     In another aspect, a wind-power electric generator set is provided by the present disclosure, including a nacelle, and the electric motor as described above, in which the circulating fan of the cooling system of the electric motor is arranged at a side of the nacelle. 
     In the cooling system and the electric motor provided by the present disclosure, by arranging the flow-confluence chamber in the circumferential direction of the stator support; arranging the accommodating chamber in the circumferential direction of the stator support, arranging the heat exchanger in the accommodating chamber or the flow-confluence chamber, arranging the circulating fan at the stator support in the axial direction, and forming the first ventilation holes located at an outer side of the accommodating chamber at two ends of the stator support in the axial direction respectively, it can be achieved that the heat-generating member inside the electric motor can be cooled cyclically, and the overall structure of the cooling system can be simple and compact and can occupy smaller space. In addition, by adopting the electric motor, the wind-power electric generator set provided by the present disclosure can effectively reduce the size of the nacelle, thereby reducing the overall machine cost and the overall machine load, and improving the reliability and maintainability of the wind-power electric generator set. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure can be better understood from the following description of the specific embodiments of the present disclosure in conjunction with the drawings; herein, by reading the following detailed description of the non-limiting embodiments with reference to the drawings, other features, objects, and advantages of the present disclosure will become more apparent, and the same or similar reference signs indicate the same or similar features. 
         FIG. 1  shows a schematic view of an overall layout structure of an electric motor according to the embodiments of the present disclosure; 
         FIG. 2  shows a partial structural schematic view of a cooling system of an electric motor according to the embodiments of the present disclosure; 
         FIG. 3  shows a partial structural schematic view of the cooling system of the electric motor shown in  FIG. 2  in an axial direction; 
         FIG. 4  shows a cross-sectional view of the cooling system of the electric motor shown in the direction A-A in  FIG. 3 ; 
         FIG. 5  shows a partial exploded structural schematic view of the cooling system shown in  FIG. 2 ; 
         FIG. 6  shows a structural schematic view of a fixing support of the cooling system shown in  FIG. 5 ; 
         FIG. 7  shows a structural schematic view of another fixing support of the cooling system shown in  FIG. 5 . 
     
    
    
     In the drawings:
           1 —main shaft;  1   a —stator winding set;  1   b —stator iron core;  1   c —air gap;  1   d —radial ventilation channel;  10 —stator support;  101 —accommodating chamber;  102 —flow-confluence chamber;  103 —isolation chamber;  11 —first separating plate;  111 —inspection opening;  12 —second separating plate;  13 —ring-shaped plate;  14 —fixing support;  141 —first plate;  142 —second plate;  143 —third plate;  144 —mounting groove;  15 —cover plate;  151 —first opening;  152 —second opening;  16 —filter member;  17 —first end plate;  18 —second end plate; a—first ventilation hole; b—second ventilation hole;     20 —rotor support;  2   a —magnetic steel;  21 —ventilation chamber;     30 —heat exchanger;  31 —first joint;  32 —second joint;  40 —circulating fan;  401 —housing;  402 —fan;  403 —motor;  41 —air inlet;  42 —air outlet;  43 —air supplying pipe;  50 —liquid supplying pipe;  60 —liquid returning pipe/air returning pipe;     100 —electric motor;  300 —nacelle.       

     DETAILED DESCRIPTION 
     The features and exemplary embodiments of various aspects of the present disclosure will be described in detail below. Many specific details are disclosed in the following detailed description in order to fully understand the present disclosure. However, it is obvious to those skilled in the art that the present disclosure can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of the present disclosure by showing examples of the present disclosure. The present disclosure is by no means limited to any specific configurations and algorithms proposed below, but covers any modification, replacement and improvement of elements, member and algorithms without departing from the spirit of the present disclosure. In the drawings and the following description, well-known structures and technologies are not shown in order to avoid unnecessary obscurity of the present disclosure. 
     In order to better understand the present disclosure, a cooling system, an electric motor and a wind-power electric generator set in the embodiments of the present disclosure will be described in detail below in conjunction with  FIG. 1  to  FIG. 7 . 
     Referring to  FIG. 1  and  FIG. 2  together, the electric motor  100  provided by the embodiments of the present disclosure, includes the cooling system; the cooling system has a compact structure and occupies smaller space. 
     The electric motor may have a structure of an outer rotor and an inner stator, or a structure of an outer stator and an inner rotor. The stator is fixed on a fixing shaft by a stator support  10 , the rotor is fixed on a moving shaft by a rotor support  20 , and the fixing shaft and the moving shaft are connected by a bearing and realize the relative rotation. The fixing shaft and the moving shaft together form a main shaft  1  of the electric motor. In order to ease of description, the embodiment of the present disclosure takes the electric motor with the structure of the outer rotor and the inner stator as an example for description. 
     The stator includes a stator winding set  1   a  and a plurality of stator iron cores  1   b  arranged to be spaced apart from one another in an axial direction; each of radial ventilation channels  1   d  is formed between each two adjacent stator iron cores  1   b . Each of stator iron cores  1   b  includes a yoke portion and a tooth portion (not shown in the drawings) integrally formed with the yoke portion. The stator winding set  1   a  is wound around the tooth portion, and the stator is fixed to the stator support  10  through the yoke portion. A magnetic steel  2   a  is arranged on the rotor support  20 , and an air gap  1   c  is formed between the rotor and the stator in a radial direction. The stator winding set  1   a , the stator iron cores  1   b  and the magnetic steel  2   a  are all heat-generating members, and the cooling system is used to cool the heat-generating members. 
     Referring to  FIG. 2  and  FIG. 4  together, the cooling system applied to the electric motor as described above is provided by the embodiments of the present disclosure; the electric motor includes the stator support  10  and the rotor support  20 , the stator support  10  is dynamically sealingly connected to the rotor support  20  to form ventilation chambers  21  respectively arranged at two ends of the electric motor in the axial direction, and first ventilation holes a are respectively formed at two ends of the stator support in the axial direction. 
     The cooling system includes a flow-confluence chamber  102 , an accommodating chamber  101 , a heat exchanger  30  and a circulating fan  40 . 
     The flow-confluence chamber  102  is arranged in a circumferential direction of the stator support  10 . 
     The accommodating chamber  101  is arranged in the circumferential direction of the stator support  10 ; the accommodating chamber  101  is located at an inner side of the flow-confluence chamber  102  in the radial direction and communicates with the flow-confluence chamber  102 ; and the first ventilation holes a are located outside the accommodating chamber  101 . 
     The heat exchanger  30  is arranged in the accommodating chamber  101  or in the flow-confluence chamber  102 . The heat exchanger  30  may be an air-to-air heat exchanger or an air-to-liquid heat exchanger. Optionally, the heat exchanger  30  is, such as, but not limited to, a plate-fin type heat exchanger, a pipe-fin type heat exchanger or an array pipe air-liquid type heat exchanger. A cooling medium in the heat exchanger  30  may be a liquid medium or a phase-changing medium. The cooling medium in the heat exchanger  30  exchanges heat with an external cooling system through a liquid supplying pipe  50  and a liquid returning/air returning pipe  60  located at an outer side of the stator support  10 , thereby circularly cooling the electric motor. 
     The circulating fan  40  is arranged in the circumferential direction of the stator support  10  and located at a side of the stator support  10  in the axial direction, and the circulating fan has an air inlet  41  and an air outlet  42 . Herein, after cooling air flows out of the air outlet  42  of the circulating fan  40 , a part of the cooling air enters one end of the ventilation chamber  21  which is closer; the other part of the cooling air enters the other end of the ventilation chamber  21  through the first ventilation holes a, which are respectively formed at the two ends of the stator support  10  in the axial direction, the two parts of the cooling air flow over a heat-generating member in the electric motor, and enters the air inlet  41  of the circulating fan  40  via the flow-confluence chamber  102 , the heat exchanger  30  and the accommodating chamber  101 . 
     Therefore, taking the heat exchanger  30  arranged in the accommodating chamber  101  as an example, a cooling process of the cooling system provided by the embodiments of the present disclosure is as follows: the cooling air enters the circulating fan  40  from the heat exchanger  30  through the air inlet  41 , and directly enters an external environment under a negative pressure of the circulating fan  40 , so that it can ensure the uniformity of an inlet airflow. Herein, a part of the cooling air passes through the air outlet  42  and directly enters the ventilation chamber  21  at the near end; as shown by a solid arrow W 1  in  FIG. 3 , the part of cooling air cools an end of the stator winding set  1   a , and then flows along the air gap  1   c , so that it can be achieved that a part of the magnetic steel  2   a , the rotor yoke and the stator winding set  1   a  is cooled; the other part of the cooling air enters the ventilation chamber  21  at the other end of the electric motor through the first ventilation holes a at the two ends of the stator support  10  in the axial direction; as shown by a solid arrow W 2  in  FIG. 3 , the other part of the cooling air cools the other end of the stator winding set  1   a , and then flows along the air gap  1   c  to cool the other part of the magnetic steel  2   a , the rotor yoke and the stator winding set  1   a.    
     As shown by a dotted arrow W 3  in  FIG. 3 , two parts of the cooling air entering the air gap  1   c  can cool the stator winding set  1   a  and a stator yoke through a plurality of radial ventilation channels  1   d  distributed to be spaced apart from one another in the axial direction of the stator; a temperature of the cooling air passing through the radial ventilation channels  1   d  is increased, and the cooling air with the high-temperature enters the accommodating chamber  101  via the flow-confluence chamber  102  and a second ventilation hole b under the action of the circulating fan  40 , so that the two parts of the cooling air entering the air gap  1   c  can exchange heat with the heat exchanger  30 . The flow-confluence chamber  102  and the accommodating chamber  101  forms an effective airflow organization sealing chamber in the electric motor to establish a reasonable airflow organization and to realize the effective heat dissipation of the stator winding set  1   a , the stator iron cores  1   b  and the magnetic steel  2   a . The heat exchanger  30  is connected to an external cooling system through the liquid supplying pipe  50  and the liquid returning pipe/air returning pipe  60 , so that the temperature of the cooling air is decreased to form an airflow with a relatively low temperature, and then the cooling air enters the external environment again under the action of the circulating fan  40  to perform the next cooling cycle of the airflow organization. 
     Since the circulating fan  40  is arranged in the axial direction of the electric motor, the air outlet  42  is arranged toward one of the ventilation chambers  21  at an end of the shaft of the electric motor to guide the airflow from the heat exchanger  30  to the ventilation chamber  21 ; and the airflow from the heat exchanger  30  is guided into another ventilation chamber  21  through the first ventilation holes a formed at the two ends of the stator support  10  in the axial. By means of an organic combination of the heat exchanger  30 , the circulating fan  40  and the stator support  10 , only one air outlet  42  needs to be formed on the circulating fan  40 , so that the volume of the circulating fan  40  can be reduced. 
     In addition, the liquid supplying pipe  50  and the liquid returning pipe/gas returning pipe  60  of the heat exchanger  30  are located at an outside of the accommodating chamber  101 , so that it can further simplify an internal structure of the electric motor, and can make an overall structure of the motor simpler, more compact, and occupy smaller space. 
     In the cooling system provided by the embodiments of the present disclosure, the flow-confluence chamber  102  and the accommodating chamber  101  communicating with the flow-confluence chamber  102  are formed in the circumferential direction of the stator support  10 , and the heat exchanger  30  is arranged in the flow-confluence chamber  102  or the accommodating chamber  101 , the circulating fan  40  is arranged in the axial direction of the stator support  10 , and the first ventilation holes a, which are located at an outer side of the accommodating chamber  101 , are respectively formed at two ends of the stator support in the axial direction, so that it can be achieved that the heat-generating members inside the electric motor can be cooled cyclically, and the overall structure of the cooling system can be simple and compact and can occupy smaller space. 
     The specific structure of the cooling system will be described in further detail below in conjunction with the drawings. 
     Further referring to  FIG. 1 , in some embodiments, two or more circulating fans  40  are distributed to be spaced apart from one another in the circumferential direction of the stator support  10 , thus, compared to an integral circulating fan arranged in the axial direction of the stator support, the same heat dissipation effect can be achieved, and the overall structure of the electric motor can be simple and compact and can occupy smaller space at the same time. 
     Optionally, two or more accommodating chambers  101  are distributed to be spaced apart from one another in the circumferential direction of the stator support  10  and correspond to the two or more circulating fans  40  in a one-to-one correspondence, and the heat exchanger  30  is arranged in each of the accommodating chambers  101 . Optionally, the two or more circulating fans  40  are evenly distributed in the circumferential direction of the stator support  10 ; correspondingly, the accommodating chambers  101  and the circulating fans  40  are also evenly distributed in the circumferential direction of the stator support  10 . 
     Since the ventilation chambers  21  at the two ends of the electric motor in the axial direction have a large enough volume, they can serve as a static pressure chamber, so that the ends of the stator winding set  1   a  have a uniform cooling effect, while ensuring the uniformity of the airflow entering the air gap  1   c  in the axial direction; the cooling air entering the air gap  1   c  flows along the air gap  1   c , and at the same time flows through the stator winding set  1   a  and the radial ventilation channels  1   d  of the stator iron cores  1   b  into the flow-confluence chamber  102 ; the flow-confluence chamber  102  also has a large enough volume to serve as the static pressure chamber, thereby ensuring the uniformity of the airflow in an entire circumferential space, avoiding the uneven airflow organization, and improving the uniformity of the heat dissipation of the cooling system. 
     Further referring to  FIG. 4 , the stator support  10  includes a ring-shaped plate  13  extending in the axial direction; the ring-shaped plate  13  divides the stator support  10  into the flow-confluence chamber  102  and the accommodating chamber  101  in the radial direction; the ring-shaped plate  13  is provided with at least one second ventilation hole b in the circumferential direction; and the flow-confluence chamber  102  communicates with the accommodating chamber  101  through the second ventilation hole b. 
     Further, the stator support  10  further includes a first end plate  17  and a second end plate  18  that extend in the radial direction and are arranged opposite to each other in the axial direction, and the flow-confluence chamber  102  extending through in the circumferential direction is formed by the first end plate  17 , the second end plate  18  and the ring-shaped plate  13 . 
     The stator support  10  further includes a first separating plate  11  and a second separating plate  12  that are located between the first end plate  17  and the second end plate  18 , extend in the radial direction, and are arranged coaxially; the first separating plate  11  is located on an inner side of the first end plate  17  in the radial direction, the second separating plate  12  is located on an inner side of the second end plate  18  in the radial direction, and the accommodating chamber  101  is formed by the first separating plate, the second separating plate and the ring-shaped plate  13 . 
     The first ventilation holes a are arranged on the first separating plate  11  and the second separating plate  12 ; optionally, the heat exchanger  30  is arranged in the accommodating chamber  101 ; optionally, the circulating fan  40  is arranged at an outer side of the first separating plate  11  in the axial direction. 
     Further, the circulating fan  40  includes a housing  401 , and further includes a fan  402  and a motor  403  that are accommodated in the housing  401 . The motor  403  drives the fan  402  to rotate. The air inlet  41  and the air outlet  42  are respectively arranged on the housing  401 . 
     In addition, an air supplying pipe  43  extending toward the first separating plate  11  is arranged at the air inlet  41  of the circulating fan  40 . Optionally, the air supplying pipe  43  is the pipe with a variable diameter, so as to buffer the vibration impact of a negative pressure cooling air flow generated by the circulating fan  40  on the accommodating chamber  101 . 
     For a working condition with heavy wind and sand or harsh working environment, in order to avoid insufficient heat dissipation of the electric motor due to dust accumulation or damage and failure of a component, optionally, filter members are respectively arranged at the first ventilation holes a of the first separating plate  11  and the second separating plate  12 . 
     Referring to  FIG. 5  to  FIG. 7  together, the cooling system further includes at least one fixing support  14  distributed to be spaced apart from one another in the circumferential direction of the stator support  10 , the fixing support  14  is arranged between the first separating plate  11  and the second separating plate  12 , and the heat exchanger  30  is detachably mounted on the fixing support  14 . 
     The fixing support  14  includes a first plate  141  and a second plate  142  that extend in the radial direction and are arranged opposite to each other in the circumferential direction, and a third plate  143  connecting the first plate  141  and the second plate  142  and extending in the circumferential direction of the stator support  10 ; the first plate  141  and the second plate  142  are provided with mounting grooves  144  extending in the axial direction respectively, and the heat exchanger  30  is detachably mounted on the fixing support  14  through the mounting grooves  144  of the first plate  141  and the second plate  142 . 
     As shown in  FIG. 6 , in some embodiments, the mounting grooves  144  are respectively arranged at sides of the first plate  141  and the second plate  142  facing to each other, and the heat exchanger  30  is inserted into the mounting grooves  144  of the first plate  141  and the second plate  142 . At this time, the accommodating chamber  101  is formed by the ring-shaped plate  13 , the stator support  10 , the fixing support  14  and the main shaft  1  together; the accommodating chamber  101  forms the effective airflow organization sealing chamber in the electric motor, so that the phenomenon of the airflow short circuit can be avoided when the cooling air entering the accommodating chamber  101  through the second ventilation hole b performs the heat exchange with the heat exchanger  30 . 
     In addition, when two or more accommodating chambers  101  are arranged at the stator support  10  in its own circumferential direction, two or more fixing support  14  are distributed to be spaced apart from one another in the circumferential direction of the stator support  10 , and an isolation chamber  103  is formed between each two adjacent accommodating chambers  101  by the fixing support  14 ; in other words, on an inner side of the ring-shaped plate  15  in the radial direction, the isolation chamber  103  and the accommodating chamber  101  are alternately arranged at the stator support  10  in the circumferential direction. 
     Because the flow-confluence chamber  102  communicates with the airflow organization of the heat exchanger  30  in each accommodating chamber  101  by means of the second ventilation hole b formed in the circumferential direction of the ring-shaped plate  13 , and the isolation chamber  103  communicates with the ventilation chambers  21  at the two ends of the electric motor in the axial direction through the first ventilation holes a on the first separating plate  11  and the second separating plate  12 , each isolation chamber  103  communicates with the airflow organization of each heat exchanger  30 . After any circulating fan  40  fails, other circulating fans  40  can still pass airflow through the heat exchanger  30  corresponding to the failed circulating fan  40 , so that the heat dissipation requirements of the stator winding set  1   a , the stator iron cores  1   b  and the magnetic steel  2   a  corresponding to the failed circulating fan  40  can be taken into consideration at the same time, and the reliability and the fault tolerance of the electric motor can be improved. 
     As shown in  FIG. 7 , in some embodiments, the mounting grooves  144  are respectively arranged on sides of the first plate  141  and the second plate  142  facing away from each other, and the heat exchanger  30  is inserted into the mounting groove  144  of the first plate  141  of the fixing support  14  and the mounting groove  144  of the second plate  142  of another adjacent fixing support  14 . At this time, the accommodating chamber  101  is formed by the ring-shaped plate  13 , the stator support  10 , the first plate  141  of the fixing support  14 , the second plate  142  of another adjacent fixing support  14  and the main shaft  1  together; the accommodating chamber  101  forms the effective airflow organization sealing chamber in the electric motor, so that the phenomenon of the airflow short circuit can be avoided when the cooling air entering the accommodating chamber  101  through the second ventilation hole b performs the heat exchange with the heat exchanger  30 . 
     Further referring to  FIG. 5 , an inspection opening  111  allowing the heat exchanger  30  to pass through is formed on the first separating plate  11 , and the first separating plate  11  is sealingly covered at the inspection opening  111  by a cover plate  15 . For example, a sealing ring or the like is arranged between the cover plate  15  and the inspection opening  111 . 
     A first joint  31  and a second joint  32  are arranged on the heat exchanger  30 ; a first opening  151  and a second opening  152  are formed on the cover plate  15 ; the first joint  31  extends out of the first opening  151  and is connected to the liquid supplying pipe  50 ; the second joint  32  extends out of the second opening  152  and is connected to the liquid returning pipe/air returning pipe  60 . 
     Therefore, on one hand, the fixing support  14  can be used as a reinforcing rib of the stator support  10 , which can improve the structural strength and the rigidity of the stator support  10 ; on the other hand, the heat exchanger  30  is detachably inserted into the mounting grooves  144 , and the corresponding inspection opening  111  is formed on the first separating plate  11 ; when replacing or repairing the heat exchanger  30 , it is only necessary to disassemble the cover plate  15  and pull the heat exchanger  30  in the axial direction to quickly complete the replacement work from the inspection opening  111 , so that the replacement efficiency can be improved. 
     Since the circulating fan  40  is arranged at the side of the stator support  10  in the axial direction, when the circulating fan  40  needs to be replaced, the circulating fan  40  can be directly removed from the air supplying pipe  43  without disassembling other components, so that the maintainability of the electric motor can be improved. 
     It should be noted that, although the cooling system has been described above to take the electric motor having the structure of the outer rotor and the inner stator as an example for the convenience of description, it should be understood that, according to the exemplary embodiments of the present disclosure, the working principle of the cooling system as described above can also be applied to the electric motor having the structure of outer stator and inner rotor, and the corresponding stator support  10  and rotor support  20  can be adapted to be modified. 
     In addition, a wind-power electric generator set is further provided by the embodiments of the present disclosure, including a nacelle  300 , and the electric motor as described above, in which the circulating fan  40  of the cooling system of the electric motor is arranged on a side of the nacelle  300 , so that it is convenient for mounting, maintenance and replacement in later. 
     The wind-power electric generator set provided by the embodiments of the present disclosure adopts the electric motor as described above, so that it can effectively reduce the size of the nacelle  300 , thereby reducing the cost of the overall machine and the load of the overall machine, and improving the reliability and the maintainability of the wind-power electric generator set. 
     In addition, the electric motor according to the exemplary embodiment described above can be applied to various devices that need to be provided with the electric motor, such as but not limited to the wind-power electric generator set. 
     Those skilled in the art should understand that the above-mentioned embodiments are all illustrative and not limited. Different technical features appearing in different embodiments can be combined to achieve beneficial effects. Those skilled in the art should be able to understand and implement other modified embodiments of the disclosed embodiments on the basis of studying the drawings, description, and claims. In the claims, the term “comprising” does not exclude other means or steps; when an article is not modified with a quantitative word, it is intended to include one/kind or multiple/kind of articles, and can be used interchangeably with “one/kind or multiple/kind of articles; the terms “first” and “second” are used to denote names rather than to indicate any specific order. Any reference signs in the claims should not be construed as limiting the scope of protection. The functions of multiple parts appearing in the claims can be implemented by a single hardware or software module. The appearance of certain technical features in different dependent claims does not mean that these technical features cannot be combined to achieve beneficial effects.