CN103944303A - Circulating ventilation structure of fully-closed permanent magnet synchronous traction motor - Google Patents

Abstract

The invention discloses a circulation ventilation structure of a fully enclosed permanent magnet synchronous traction motor. Front and rear baffles are respectively installed on the outer sides of the front and rear end covers, and ventilation shells are connected between the four corners of the front and rear baffles; ring-shaped through grooves are opened in the center of the front and rear end covers, and the front and rear baffles are equipped with There is an annular channel; the rotation of the fan on the rotating shaft drives the airflow from the ventilation groove between the rotor core and the stator core to the airflow through the annular channel of the front cover and the annular channel of the front baffle to the cavity in the four corners of the ventilation shell, and then through the annular channel of the rear baffle. The channel and the annular channel of the rear end cover return to the motor to form an internal circulation air path; the external air flow enters the ventilation slot between the stator core and the middle shell through the entrance of the front end cover and flows out from the outlet of the rear end cover to form an external circulation air path. The invention effectively transfers the heat of the inner rotor and winding of the motor to the environment through the inner circulation air path, and transfers most of the losses generated by the motor to the air by relying on the outer circulation air path, thereby maximizing the heat dissipation capacity.

Description

Circulation Ventilation Structure of Totally Enclosed Permanent Magnet Synchronous Traction Motor

technical field

The invention relates to a circulation ventilation structure of a motor, in particular to a circulation ventilation structure of a fully enclosed permanent magnet synchronous traction motor.

Background technique

The motor is a conversion mechanism of electromechanical energy. In the process of electromechanical energy conversion, losses are inevitable. Most of these losses are finally converted into heat, which makes the temperature of the motor part rise. Studies have shown that when the working temperature rises, the remanence density Br of the permanent magnet will decrease, such as NdFeB at 120 ° C, Br will decrease to 90%; in addition, when the temperature continues to rise, the permanent magnet will undergo irreversible demagnetization, even if it is charged Magnetic can not be completely restored to the original magnetic properties. The decline of the magnetic properties of permanent magnets will affect the reliability and stability of the traction motor, and even threaten the safety of passengers and trains. Therefore, it is necessary and important to design a reasonable and effective cooling structure.

At present, there are two commonly used cooling methods for traction motors of high-speed railway trains: natural cooling and forced ventilation cooling. Natural cooling is to use the flowing air and the motor shell to conduct convective heat dissipation. Although the natural cooling method has the advantages of simple structure, no need for additional systems, and convenient installation and maintenance, the low-speed air cooling capacity of natural cooling is low, so it is suitable for high power density motors. There are certain deficiencies; forced ventilation cooling uses flowing air to conduct convective heat dissipation on key components such as motor stators or rotors. The existing auxiliary system includes air ducts, which can provide air source for the motor.

Due to the inherent electromagnetic characteristics of permanent magnets, permanent magnets are easy to absorb dust and iron filings. In order to improve the reliability of permanent magnet synchronous traction motors, improve the life of the motor, and reduce maintenance costs, the motor adopts a fully enclosed structure. However, due to the fully enclosed structure, the winding of the main heating element of the motor and the permanent magnet of the thermal sensitive element cannot perform direct heat exchange with the cooling air, and the heat generated by the loss can only be indirectly transmitted to the outside through the stator and the casing. The design of the cooling structure is proposed. higher requirement.

Contents of the invention

The purpose of the present invention is to provide a fully enclosed permanent magnet synchronous traction motor circulation ventilation structure, which uses the form of forced ventilation and internal and external double circulation to avoid the occurrence of high temperature failure of winding insulation and irreversible demagnetization of permanent magnets at high temperature, and to ensure traction motor and Reliable operation of trains, permanent magnet synchronous traction motors for high-speed railway trains.

The technical solution adopted by the present invention to solve its technical problems is:

The invention comprises a rotor core, a stator core, a winding, a rotating shaft, a rear end cover, a front end cover and an intermediate casing, the outer sides of the front end cover and the rear end cover are respectively equipped with a front baffle and a rear baffle, and the front baffle outside the intermediate casing Ventilation shells are connected between the four corners of the board and the rear baffle, and the ventilation shells have hollow cavities through the front and back;

The center of the front end cover and the rear end cover are both provided with an annular channel, and the front baffle and the rear baffle are respectively provided with an annular channel on the side where the front end cover and the rear end cover are connected to the annular channel, and the annular channel communicates with the hollow cavity of the ventilation shell;

A fan is installed on the rotating shaft on the side of the front cover, and the rotation of the fan drives the airflow in the motor to flow from the ventilation slot between the rotor core and the stator core, through the annular channel of the front cover and the annular channel of the front baffle to the ventilation shell at the four corners. The hollow cavity returns to the ventilation groove between the rotor core and the stator core through the annular channel of the rear baffle and the annular channel of the rear end cover to form an internal circulation air path.

The external air flows through the inlet of the front end cover and enters the ventilation slot between the stator core and the middle casing, and flows out from the outlet of the rear end cover to form an external circulation air path.

The beneficial effects of the present invention are:

1. Relying on the forced ventilation system of external circulation, most of the loss generated by the motor is transferred to the air.

2. On the basis of the external circulation system taking away most of the heat, the heat of the inner rotor and winding of the motor is effectively transferred to the environment through the internal circulation system.

3. Make full use of the bogie space of high-speed trains to maximize the cooling capacity.

Description of drawings

Fig. 1 is the overall schematic diagram of the present invention.

Fig. 2 is a schematic diagram of the internal circulation structure of the present invention.

Fig. 3 is a front view and a partial cross-sectional schematic view of the internal circulation structure of the present invention.

Fig. 4 is a schematic axial sectional view of the present invention.

Fig. 5 is a schematic radial cross-sectional view of the present invention.

In the figure: 1. Rotor core, 2. Stator core, 3. Winding, 4. Front cover, 5. Middle shell, 6. Rear cover, 7. Rotary shaft, 8. Ventilation shell, 9. Fan, 10. Suspension, 11, front baffle, 12, rear baffle, 13, inner circulation air path, 14, outer circulation air path.

Detailed ways

The present invention will be further described below in conjunction with drawings and embodiments.

As shown in Figures 1 and 4, the present invention includes a rotor core 1, a stator core 2, a winding 3, a rotating shaft 7, a rear end cover 6, a front end cover 4 and an intermediate housing 5, and the front end cover 4 and the rear end cover 6. Front baffles 11 and rear baffles 12 are installed on the outer sides respectively, and ventilating shells 8 are connected between the four corners of the front baffles 11 and the rear baffles 12 outside the middle shell 5, and the ventilating shells 8 have hollow cavities through which the front and rear pass; 4 and the center of the rear end cover 6 are provided with an annular through groove, and the annular through groove communicates with the inside of the motor. The front baffle 11 and the rear baffle 12 are respectively provided with an annular groove on the side where the front end cover 4 and the rear end cover 6 are connected to the annular through groove. The channel, the annular channel communicates with the hollow cavity of the ventilation shell 8; the fan 9 is installed on the rotating shaft 7 on the side of the front cover 4, and the fan 9 rotates to drive the airflow in the motor to pass through the ventilation slot between the rotor core 1 and the stator core 2 Through the annular channel of the front end cover 4 and the annular channel of the front baffle 11, it flows to the cavity in the four corners of the ventilation shell 8, and then returns to the rotor core 1 and the The ventilation slots between the stator cores 2 form an inner circulation air path 13 .

As shown in Figure 2 and Figure 3, the front baffle 11 and the rear baffle 12 are connected at both ends of the ventilation shell 8, and the annular hollow cavity of the front baffle 11 and the rear baffle 12 are connected with the hollow cavity of the ventilation shell 8 as a whole. , as part of the internal circulation air passage 13 components.

As shown in FIG. 4 , the external air flows through the upper inlet of the front end cover 4 and enters the ventilation slot between the stator core 2 and the middle casing 5 , and flows out from the outlet of the rear end cover 6 to form an outer circulation air path 14 .

As shown in Figure 1 and Figure 4, the existing fully enclosed permanent magnet synchronous traction motor includes: a rotating shaft 7, a rotor core 1 sleeved on the rotating shaft 7, a stator sleeved outside the rotor core 1 and separated by a small ventilation slot The iron core 2, the winding 3 embedded in the slot of the stator core 2, the middle casing 5 surrounding the stator core 2, the front end cover 4 and the rear end cover 6 respectively located on both sides of the middle casing 5, located on the middle casing 5 And the suspension 10 connected with the bogie of the outside.

As shown in Figure 4 and Figure 5, the inner circulation air path 13: the side of the rotating shaft 7 near the front end cover 4 is equipped with a fan 9, and when the motor rotates, the fan 9 rotates with the rotating shaft 7 to stir the air inside the motor, and its working principle is the same The compressor is the same. The pressure on the front and back sides is different, so that the air flows through the ventilation groove between the rotor core 1 and the stator core 2, and enters the rear baffle 12 through the rear end cover 6, passes through the hollow cavity of the ventilation shell 8 at the four corners, and then passes through the front The baffle plate 11 enters the front end cover 4 to form a complete air path of the internal circulation system.

In the internal circulation system, the fan 9 increases the air velocity in the motor, fully exchanges heat with the rotor core 1 and the winding 3, and provides power for the flow of the internal circulation air path. The internal circulation system introduces the internal air of the motor into the internal circulation air passage 13, so that the internal air can directly exchange heat with the external environment, without heat dissipation through the stator core 2 to the external circulation air passage 14, and the efficiency of heat exchange is improved. The structures of the front baffle plate 11, the rear baffle plate 12 and the ventilation shell 8 of the inner circulation air path 13 can have various forms, and the present invention can be applied to the permanent magnet synchronous traction motor of the high-speed railway train, and its size must meet the requirements of the high-speed railway train. Bogie size requirements.

As shown in FIG. 4 and FIG. 5 , the shape of the outer circulation air passage 14 may be square, circular or any other air duct structure, here a square is taken as an example. The external circulation system adopts the form of forced ventilation. The cooling air enters the motor through the opening of the front end cover 4. There is a circle of baffles in the front end cover 4 to isolate the cooling air from the rotor core 1, stator core 2 and winding 3. The cooling air flows through Between the middle shell 5 and the stator core 2, the outlet of the rear end cover flows out, which is the complete air path of the external circulation system. In the external circulation system, the cooling air can effectively take the heat on the stator core 2 away from the motor by heat convection.

Concrete implementation work process of the present invention is:

The permanent magnet synchronous traction motor is dissipated in the form of internal and external double circulation, in which the forced ventilation is the cooling air provided by the train air system to form the external circulation air path 14, and its path passes through the air inlet and the front end cover 4 and flows through the stator core 2 the outer surface, and then enter the atmosphere through the rear end cover 6. The front end cover 4 and the stator core 2 isolate the cooling air in the outer circulation from the air inside the motor through a ring of metal baffles on the end cover to ensure that iron filings and dust in the air will not enter the inside of the motor.

The internal circulation system stirs the air in the motor through the fan 9 on the rotating shaft, passes through the annular channel of the front end cover 4, flows through the hollow cavity of the front baffle 11, the ventilation shell 8 and the rear baffle 12, and then passes through the hollow cavity of the rear end cover 6. The annular channel enters the inside of the motor to form a complete inner circulation air path 13 . In this air path, the air inside the motor exchanges heat with the ambient air, and the temperature difference between the two is large, which can effectively reduce the temperature of the circulating air, and further reduce the components such as the rotor and winding inside the motor. The air in the internal and external circulation systems does not communicate with each other.

Therefore, the present invention can rely on the forced ventilation system of the external circulation to transfer most of the losses generated by the motor to the air; and on the basis that the external circulation system takes away most of the heat, the inner rotor and the winding The heat is transferred to the environment; and the high-speed train bogie space is fully utilized to maximize the heat dissipation capacity.

The content described in the embodiments of this specification is only an enumeration of the implementation forms of the inventive concept. The protection scope of the present invention should not be regarded as limited to the specific forms stated in the embodiments. Equivalent technical means that a person can think of based on the concept of the present invention.

Claims (2)

1. A fully enclosed permanent magnet synchronous traction motor circulation ventilation structure, including rotor core (1), stator core (2), winding (3), rotating shaft (7), rear end cover (6), front end The cover (4) and the middle shell (5) are characterized in that: the outer side of the front end cover (4) and the rear end cover (6) are respectively equipped with a front baffle (11) and a rear baffle (12), and the middle shell (5 ) outside the front baffle (11) and the four corners of the rear baffle (12) are connected with a ventilation shell (8), and the ventilation shell (8) has a hollow cavity through the front and back; The center of the front end cover (4) and the rear end cover (6) is provided with an annular through groove, and the front baffle (11) and the rear baffle (12) are connected with the front end cover (4) and the rear end cover (6) respectively. An annular channel is provided on the docking side, and the annular channel communicates with the hollow cavity of the ventilation shell (8); A fan (9) is installed on the shaft (7) near the front end cover (4), and the rotation of the fan (9) drives the airflow in the motor to pass through the ventilation slot between the rotor core (1) and the stator core (2). The annular channel of the front cover (4) and the annular channel of the front baffle (11) flow to the hollow cavity of the ventilation shell (8) at the four corners, and then pass through the annular channel of the rear baffle (12) and the annular channel of the rear end cover (6). The through slot returns to the ventilation slot between the rotor core (1) and the stator core (2) to form an inner circulation air path (13). 2. A fully enclosed permanent magnet synchronous traction motor circulation ventilation structure according to claim 1, characterized in that: the external air flows through the entrance of the front cover (4) and enters the stator core (2) and the middle shell The ventilation groove between (5) flows out from the outlet of the rear end cover (6) to form an external circulation air path (14).