Stator end sealing structure of large asynchronous motor

Abstract

The utility model discloses a stator end part sealing structure of a large-scale asynchronous motor, which comprises a wind shield and an inner end hoop, the wind shield is arranged on one side of the end part of a stator coil deviating from a rotor and forms a vertical sealing surface, and the inner end hoop is arranged on a surface line of the end part of the stator coil and is used for ensuring a radial gap between the wind shield and an axial flow fan. An air duct insertion strip is arranged between the wind shield and the inserted line end bottom line of the stator, and the air duct insertion strip axially clings to the stator coil end bottom line binding end hoop. The inner circle of the inner end hoop is machined through metal, and the outer circle of the inner end hoop is of a slope structure. According to the invention, the novel stator end sealing structure is divided into two parts to cool the iron core and the coil, the coil end part extending out of the wind shield is cooled, the loss of the coil end part on the inner side of the wind shield is reduced compared with the original, the temperature rise of the whole motor is ensured to be within a reasonable range, the end space is saved and greatly shortened while ventilation and heat dissipation are satisfied, and the service life of the motor is prolonged. A motor shaft system is shortened, motor raw materials and manufacturing cost are saved, and stability and reliability of motor operation are improved.

Description

Technical Field

[0001] The utility model relates to a stator end sealing structure of a large asynchronous motor, belonging to the technical field of motors. Background Art

[0002] During the development of large-capacity asynchronous motors, due to the large motor capacity and large motor cavity loss, a large amount of internal air cooling air is required. Combined with the internal wind resistance and flow characteristics of such motors, symmetrically distributed coaxial axial fans are required to meet the cooling requirements.

[0003] Figure 1 This is a schematic diagram of a typical symmetrical air path with coaxial axial fan cooling. Figure 1 I is the rotor, II is the axial flow fan, III is the wind shield, IV is the stator, and V is the air-water cooler. The external air path of the motor is mainly the air-water cooler, with a single water chamber core placed horizontally. The cooling water enters from the left flange, flows through the core inside the air-water cooler, and flows out from the right flange. In this process, heat exchange is carried out with the hot air inside the motor, thereby cooling the hot air inside the motor. The internal air path of the motor is driven by the rotor core ventilation slot plate on the rotor and the axial flow fan installed coaxially and symmetrically. The cold air enters from both sides of the base, and after being pressurized by the axial flow fans on both sides, it is mainly divided into two parts. One part of the cold air flows through the end of the stator coil to the ventilation hole in the middle wall of the stator base, and then flows into the air-water cooler to exchange heat with the air-water cooler. This part mainly cools the end of the motor; the other part of the cold air flows through the rotor core ventilation duct to the stator-rotor air gap and then flows to the stator core ventilation duct before flowing into the air-water cooler. This part mainly cools the straight part of the motor core and coil. When designing the motor, the air volume of the two parts needs to be reasonably distributed to ensure uniform cooling of all parts of the motor.

[0004] To ensure that the pressure head and efficiency of the axial flow fan meet the design requirements, Figure 1 The radial clearance value between the central axial flow fan and the wind shield must be guaranteed. In actual design, the radial clearance is designed to be about 5mm. Due to the large amount of cooling air required for the internal air path, the size of the air inlet windows on the left and right sides of the machine base wind shield must be guaranteed. Considering that the wiring error of the stator coil after the stator coil is embedded requires space to be reserved, the wind shield needs to have a certain axial distance from the end of the stator coil in actual design. Under the condition of the same core length, the axial space distance required for this type of end wind shield structure is relatively large, resulting in the motor shaft system being too long. When the critical speed and disturbance are reviewed during motor design, the design requirements are often not met. At the same time, the length of the motor base needs to be lengthened accordingly, resulting in an increase in the total weight of the motor, an increase in cost, and a series of problems such as large packaging and transportation, and on-site installation foundation.

[0005] Figure 2 and Figure 3The wind shield required by the original structure is made of insulating alkali-free glass silk cloth to meet the creepage distance requirements of the stator coil ends. The cost is relatively high. In addition, due to the large size of the components, the processing is difficult, and the deformation is difficult to control. It is difficult to meet the axial clearance requirements between the axial fan and the wind shield, which can easily cause the pressure head and efficiency of the axial fan to fail to meet the design requirements, affecting the overall temperature rise of the motor. There is room for improvement. Utility Model Content

[0006] The technical problem to be solved by the utility model is that the existing stator end sealing structure has high cost, great processing difficulty and difficult to control deformation, and it is difficult to meet the axial clearance requirements between the axial flow fan and the wind shield, which easily causes the pressure head and efficiency of the axial flow fan to fail to meet the design requirements, affecting the overall temperature rise of the motor.

[0007] In order to solve the above technical problems, the utility model provides a stator end sealing structure for a large asynchronous motor, which can reduce costs and increase efficiency in raw materials and production, meet the cooling requirements of the stator coil ends, ensure that the temperature rise of the motor is within a reasonable range, ensure the insulation life of the motor, and improve the stability and reliability of the motor operation.

[0008] In order to achieve the above technical objectives and the above technical effects, this application is implemented through the following technical solutions:

[0009] A stator end sealing structure for a large asynchronous motor comprises a wind shield and an inner end hoop. The wind shield is arranged on the side of the stator coil end facing away from the rotor and forms a vertical sealing surface. The inner end hoop is arranged on the surface line of the stator coil end to ensure a radial gap between the wind shield and the axial flow fan.

[0010] Preferably, an air duct fillet is provided between the wind shield and the bottom line of the stator coil end, and the air duct fillet is axially close to the bottom line binding end hoop of the stator coil end.

[0011] Preferably, the wind shield is located at two-thirds of the axial position of the stator coil end.

[0012] Preferably, a conformable felt 1 is filled between the bottom line and the surface line of the stator coil end, and the conformable felt 1 is fixed to the bottom line and the surface line of the stator coil end.

[0013] Furthermore, the conformable felt is filled at the same axial position between the bottom line and the surface line of the stator coil end.

[0014] Preferably, the inner circle of the inner end hoop is metal-processed, and the outer circle of the inner end hoop is a slope structure.

[0015] Preferably, a second conformable felt is provided as a gap pad between the inner end hoop and the surface line of the stator coil.

[0016] The utility model provides a stator end sealing structure for a large asynchronous motor, which has the following advantages:

[0017] 1. When the utility model is used, the cold air in the inner air path enters from both sides of the base, flows through the coil ends outside the wind shield, and then is pressurized by the axial flow fans on both sides, and is divided into two parts to cool the iron core and the coil. At this time, the coil ends extending out of the wind shield have been cooled, and the loss of the coil ends inside the wind shield is reduced compared to before. The area of ​​the ventilation holes on the stator base wall should be adjusted accordingly to ensure that the air volume distribution of the inner air path is basically uniform, meet the cooling requirements of the stator coil ends, ensure that the temperature rise of the motor is within a reasonable range, ensure the insulation life of the motor, and improve the stability and reliability of the motor operation.

[0018] 2. When the utility model is used, by adjusting the position and type of the stator end seal, the end ventilation axial space can be saved by about 200-250mm on one side, the total length of the motor and the rotor shaft system can be shortened by about 400-500mm, which can greatly increase the critical speed of the rotor, reduce the rotor disturbance, and improve the vibration level of the motor. The motor has a more compact size, which can reduce costs and increase efficiency in raw materials and production, and facilitate subsequent user basic construction and installation and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of a typical symmetrical air path with a coaxial axial fan cooling air path in the prior art;

[0020] Figure 2 This is a schematic diagram of the windshield structure of the original structure of the prior art;

[0021] Figure 3 yes Figure 2 Schematic diagram of the AA section;

[0022] Figure 4 This is a schematic diagram of the application wind path of a stator end sealing structure of a large asynchronous motor of the utility model;

[0023] Figure 5 This is a schematic diagram of the structure of the inner end hoop in the embodiment of the utility model;

[0024] Figure 6 yes Figure 5 Schematic diagram of the middle BB section;

[0025] In the figure:

[0026] 1- stator; 2- rotor; 3- axial flow fan; 4- wind deflector; 5- inner end hoop; 6- air duct insert strip; 7- conformable felt 1; 8- polyester glass square rope; 9- conformable felt 2. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present utility model, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technical personnel in the field without creative work are within the scope of protection of the present utility model.

[0028] Reference Figure 4 , a stator end sealing structure of a large asynchronous motor, including a wind shield 4, which is originally installed on the side of the stator 1 coil end close to the rotor 2 to the side of the stator 1 coil end away from the rotor 2, and the wind shield 4 forms a vertical sealing surface between the side of the stator 1 coil end away from the rotor 2 and the air-water cooler, thereby ensuring the radial clearance of the axial flow fan 3, and the inner end hoop 5 is arranged on the surface line of the stator 1 coil end to ensure the radial clearance between the wind shield 4 and the axial flow fan 3. In a feasible embodiment, the wind shield 4 can be installed at any axial position of the stator 1 coil end. In this embodiment, the moving position of the wind shield 4 is preferably at two-thirds of the stator 1 coil end.

[0029] Reference Figure 4-Figure 6 A stator end sealing structure of a large asynchronous motor also includes an inner end hoop 5, which is made of a mesh-shaped weftless belt and is installed on the surface line of the stator 1 coil end. The inner circle of the inner end cover is processed by metal processing to ensure the radial gap between the wind shield 4 and the rotor 2 axial flow fan 3.

[0030] Reference Figure 4 In a further embodiment, a duct fillet 6 is installed between the wind shield 4 and the bottom line of the stator 1 for sealing. In this embodiment, the duct fillet 6 is preferably made of chloroprene rubber. The duct fillet 6 is axially close to the bottom line of the stator 1 coil end and is fixed by an end hoop, thereby achieving sealing of the stator 1 coil bottom line.

[0031] Reference Figure 4 In a further embodiment, the same axial position between the bottom line and the surface line of the stator 1 coil end is filled with a conformable felt 7, and the conformable felt 7 is tied and fixed to the bottom line and the surface line of the stator 1 coil end by a polyester glass square rope 8, thereby achieving sealing in the middle of the stator 1 coil.

[0032] Reference Figure 4 In a further embodiment, the gap between the inner end hoop 5 and the surface line of the stator 1 coil, and the gap between the surface lines of the two coil ends are padded with a conformable felt 9, and tied and fixed with the surface line of the stator 1 coil. The stator 1 coil end is usually arranged in a bell-mouth shape, and the outer circle of the inner end hoop 5 is a slope structure, which fits the bell-mouth of the stator 1 coil end, thereby achieving sealing of the stator 1 coil surface line.

[0033] The stator end sealing structure of the utility model can significantly save end space and shorten the motor shaft system while meeting the requirements of ventilation and heat dissipation, thus saving motor raw materials and manufacturing costs, and improving the stability and reliability of motor operation.

[0034] The above is only a preferred embodiment of the utility model, and is not any formal or substantial limitation of the utility model. It should be pointed out that ordinary technicians in this technical field can make some improvements and supplements without departing from the utility model, and these improvements and supplements should also be regarded as the protection scope of the utility model. Any technician familiar with this profession can make some changes, modifications and equivalent changes made by using the technical content disclosed above without departing from the spirit and scope of the utility model, which are all equivalent embodiments of the utility model; at the same time, any changes, modifications and evolutions of any equivalent changes made to the above embodiments based on the essential technology of the utility model are still within the scope of the technical solution of the utility model.

Claims

1. A stator end sealing structure for a large asynchronous motor, characterized in that: It comprises a windshield (4) and an inner end hoop (5), wherein the windshield (4) is arranged on the side of the stator (1) coil end facing away from the rotor (2) and forms a vertical sealing surface, and the inner end hoop (5) is arranged on the surface line of the stator (1) coil end and is used to ensure a radial gap between the windshield (4) and the axial flow fan (3).

2. A stator end sealing structure for a large asynchronous motor as claimed in claim 1, characterized in that: An air duct fillet (6) is provided between the wind shield (4) and the bottom line of the stator (1) end of the coil, and the air duct fillet (6) is axially close to the bottom line binding end hoop of the stator (1) coil end.

3. The stator end sealing structure of a large asynchronous motor according to claim 1, characterized in that: The wind shield (4) is located at the axial two-thirds position of the coil end of the stator (1).

4. The stator end sealing structure of a large asynchronous motor according to claim 1, characterized in that: A conformable felt (7) is filled between the bottom line and the top line of the stator (1) coil end, and the conformable felt (7) is fixed to the bottom line and the top line of the stator (1) coil end.

5. A stator end sealing structure for a large asynchronous motor as claimed in claim 4, characterized in that: The conformable felt (7) is filled at the same axial position between the bottom line and the surface line of the stator (1) coil end.

6. The stator end sealing structure of a large asynchronous motor according to claim 1, characterized in that: The inner circle of the inner end hoop (5) is metal-processed, and the outer circle of the inner end hoop (5) is a slope structure.

7. The stator end sealing structure of a large asynchronous motor according to claim 1, characterized in that: A gap pad between the inner end hoop (5) and the stator (1) coil surface line is provided with a conformable felt (9).

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