Internal air cooling structure of motor bearing

Abstract

The utility model relates to an internal air cooling structure of a motor bearing, comprising a housing, one end of the housing is provided with a front end cover, and the other end of the housing is provided with a rear end cover; a stator is installed in the shell, the front end cover and the rear end cover are rotationally connected with a rotor shaft through a front bearing and a rear bearing respectively, an inner cooling fan and a rotor are sequentially installed on the rotor shaft, a rotor air channel is axially formed in the rotor, a cooling air channel is formed in the inner cooling fan, and an air gap channel is reserved between the rotor and the stator. The adjacent ports of the rotor air duct and the cooling air duct are communicated, and the outer port of the cooling air duct faces the air gap channel or the extension line thereof. The bearing is simple in structure, simple in manufacturing process and free of the risk that water leaks to the bearing; heat of the shaft and the rotor iron core is rapidly taken away through the rotating inner cooling fan, the temperature of the rotor is reduced, and the heat of the rotor conducted to the bearing is reduced. The wind flowing at high speed blows part of heat at the end part of the winding to the inner wall of the shell, and the heat is taken away by cooling water of the shell, so that the winding temperature is reduced, and the heat radiated to the bearing by the stator part is reduced.

Description

Technical Field

[0001] This utility model belongs to the field of motor technology and relates to the internal air-cooling structure of motor bearings. Background Technology

[0002] In commonly used air-cooled motors, the bearings are usually lubricated with grease, and the bearing temperature is cooled by the air blown over the end cover by an internal cooling fan; in oil-cooled motors, the bearings are lubricated with oil, and the flowing oil lowers the bearing temperature.

[0003] In some special applications, external internal cooling fans are not permitted, nor can water lubrication be used to reduce bearing temperature as in oil-cooled motors. The only option is to add a water jacket around the bearing housing for cooling, which significantly increases manufacturing difficulty and operational risks; even a slight leak can render the bearing unusable. This technology achieves the goal of reducing bearing temperature through an internal heat dissipation structure without using the aforementioned measures. Summary of the Invention

[0004] The purpose of this invention is to provide an internal air-cooled structure that can solve the above-mentioned problems and reduce the heat radiated from the stator to the bearing.

[0005] According to the technical solution provided by this utility model: an internal air-cooled type includes a housing, a front end cover installed at one end of the housing, and a rear end cover installed at the other end of the housing; a stator is installed in the housing, and a rotor shaft is rotatably connected to the front end cover and the rear end cover through a front bearing and a rear bearing, respectively. An internal cooling fan and a rotor are installed sequentially on the rotor shaft, a rotor air duct is opened in the central axis of the rotor, a cooling air duct is provided in the internal cooling fan, an air gap channel is left between the rotor and the stator, adjacent ports of the rotor air duct and the cooling air duct are connected, and the outer port of the cooling air duct faces the air gap channel or its extension line.

[0006] As a further improvement of this utility model, the front end of the rotor shaft extends out of the front cover and the rear end is sealed in the rear cover.

[0007] As a further improvement of this utility model, the inner port of the cooling air duct is adjacent to and connected to the rotor air duct, the outer port of the cooling air duct is located at the maximum outer diameter of the inner cooling fan, the outer port of the cooling air duct is perpendicular to the extension line of the air gap channel, and the maximum diameter of the inner cooling fan is smaller than the outer diameter of the rotor.

[0008] As a further improvement of this utility model, cooling water channels are provided on the shell.

[0009] As a further improvement of this utility model, the right end of the rotor air duct faces the rear bearing.

[0010] As a further improvement of this utility model, the front cover and the rear cover respectively cover the front bearing and the rear bearing.

[0011] As a further improvement of this utility model, the front end of the rotor shaft is the driving end, which extends out of the front end cover and drives the thermal load; the internal cooling fan is interference-fitted onto the rotor shaft and close to its driving end, and the inner port of the cooling air duct is located on the outer periphery of the rotor shaft.

[0012] As a further improvement of this utility model, the internal cooling fan is located between the rotor and the front bearing.

[0013] As a further improvement of this utility model, a wind vane is provided at the right end of the rotor, and the wind vane is located radially between the air gap channel and the rotor air duct.

[0014] As a further improvement of this utility model, the rotor air duct is evenly distributed in a ring shape in the rotor.

[0015] The positive and progressive effects of this application are as follows:

[0016] This utility model has a simple structure and a simple manufacturing process, eliminating the risk of water leakage to the bearings. The rotating internal cooling fan quickly removes heat from the shaft and rotor core, reducing the rotor temperature and minimizing heat transfer to the bearings. The high-speed airflow blows heat from the winding ends to the inner wall of the housing, where the cooling water removes the heat, further reducing the winding temperature and minimizing heat radiated from the stator to the bearings. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of this utility model.

[0018] Figure 2 This is a view of the end face of the cast aluminum rotor in the rotor of this utility model.

[0019] Figures 1-2 The components include an internal cooling fan 1, an air gap channel 2, a fan blade 3, a rotor air duct 4, a housing 5, a front cover 6, a rear cover 7, a stator 8, a rotor shaft 9, a rotor 10, a front bearing 11, a rear bearing 12, and a cooling air duct 13. Detailed Implementation

[0020] It should be noted that, where there is no conflict, the embodiments and features in the embodiments of this utility model can be combined with each other. The present utility model will now be described in detail with reference to the accompanying drawings and embodiments.

[0021] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0022] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this utility model described herein. Furthermore, terms such as "comprising" and "having" mean that in addition to those already listed in "comprising" and "having," other unlisted contents may also be included; for example, a process, method, system, product, or device may include a series of steps or units, not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products, or devices.

[0023] Due to the angle of the drawing, some parts may not be drawn, but their positions and connections can be understood from the text descriptions.

[0024] like Figure 1 As shown, this utility model is an internal air-cooled structure for an electric motor bearing, including a housing 5, a front cover 6 installed at one end of the housing 5, and a rear cover 7 installed at the other end of the housing 5. A stator 8 is installed in the housing 5. A rotor shaft 9 is rotatably connected to the front cover 6 and the rear cover 7 through a front bearing 11 and a rear bearing 12, respectively. The front end of the rotor shaft 9 extends out of the front cover 6, and the rear end is sealed in the rear cover. An internal cooling fan 1 and a rotor 10 are installed sequentially on the rotor shaft 9. A rotor air duct 4 is axially opened in the rotor 10, and a cooling air duct 13 is provided in the internal cooling fan 1. An air gap channel 2 is left between the rotor 10 and the stator 8. The adjacent ports of the rotor air duct 4 and the cooling air duct 13 are connected, and the outer port of the cooling air duct 13 faces the air gap channel 2 or its extension.

[0025] The inner port of the cooling air duct 13 is adjacent to and connected to the inner cooling air duct 13. The outer port of the cooling air duct 13 is located at the maximum outer diameter of the inner cooling fan 1. The outer port of the cooling air duct 13 is perpendicular to the extension line of the air gap channel 2, and the maximum diameter of the inner cooling fan 1 is smaller than the outer diameter of the rotor 10. Thus, when the inner cooling fan 1 draws air from the rotor air duct 4, because the outer diameter of the inner cooling fan 1 is smaller than the outer diameter of the rotor, it is easy to force hot air to flow through the air gap channel 2, forcing some of the heat of the rotor 10 to be carried out by the air and flowing along the air gap channel 2. The heat of the air gap channel 2 is transferred to the stator 8 through thermal radiation and contact conduction. Another part of the heat of the rotor 10 is blown from the inner cooling fan 1 to the winding end of the stator 8 and the housing 5, and finally the heat of the stator 8 is also transferred to the housing 5. The housing 5 is provided with cooling water channels, through which low-temperature water flowing inside the housing 5 carries away the heat.

[0026] The right end of the rotor air duct 4 faces the rear bearing 12, which is beneficial for reducing the temperature of the rear bearing 12.

[0027] The front cover 6 and the rear cover 7 cover the front bearing 11 and the rear bearing 12 respectively to prevent impurities from entering the front bearing 11 and the rear bearing 12.

[0028] The front end of the rotor shaft 9 is the drive end, which extends out of the front cover 6 and drives the heat load (such as a compressor). The internal cooling fan 1 is interference-fitted onto the rotor shaft 9 and close to its drive end. The inner port of the cooling air duct 13 is located on the outer periphery of the rotor shaft 9. When the heat from the center of the rotor shaft 9 is conducted to the front bearing 11 through the internal cooling fan 1, the heat is dissipated to the housing 5 through the cooling air duct 13, the hub portion of the internal cooling fan 1, and the rotation of the internal cooling fan 1, thereby reducing the temperature of the front bearing 11 and the drive end of the rotor shaft 9.

[0029] The internal cooling fan 1 is located between the rotor 10 and the front bearing 11. Since the temperature of the rotor 10, which is made of cast aluminum, is higher than the temperature of the stator 8 and the ambient temperature, the heat of the rotor 10 is transferred to the bearing chamber of the front cover 6 through thermal radiation, which increases the temperature of the front bearing 11. Therefore, the installation of the internal cooling fan 1 blocks this thermal radiation.

[0030] The rotor 10 has a fan blade 3 at the right end. The fan blade 3 is located radially between the air gap channel 2 and the rotor air duct 4. When the internal cooling fan 1 draws hot air from the rotor air duct 4 and forces it to flow through the air gap channel 2, the fan blade 3 shortens to reduce the rear air pressure, increases the pressure difference with the end of the internal cooling fan 1, and accelerates the air flow.

[0031] like Figure 2 As shown, the rotor air ducts 4 are evenly distributed in a ring shape within the rotor 10. In this embodiment, there are six rotor air ducts 4. The cross-section of the rotor air ducts 4 is an oblong shape, which increases the ventilation area compared to a round hole.

[0032] The theoretically calculated and measured temperatures of the stator winding ends, rotor core, rotor shaft, and bearings before and after using this internal cooling fan heat dissipation structure are as follows:

[0033]

[0034] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of this utility model, and the utility model is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of this utility model, and these modifications and improvements are also considered to be within the protection scope of this utility model.

Claims

1. An inner air cooling structure of a motor bearing, comprising a shell (5), one end of the shell (5) is installed with a front end cover (6), the other end of the shell (5) is installed with a rear end cover (7); a stator (8) is installed in the shell (5), the front end cover (6) and the rear end cover (7) are respectively connected with a rotor shaft (9) through a front bearing (11) and a rear bearing (12) in rotation, characterized in that, The rotor shaft (9) is sequentially installed with the inner cooling fan (1) and the rotor (10), the rotor (10) is axially provided with the rotor air channel (4), the inner cooling fan (1) is provided with the cooling air channel (13), the rotor (10) and the stator (8) are left with the air gap channel (2), the rotor air channel (4) and the cooling air channel (13) are connected with each other through adjacent ports, and the outer port of the cooling air channel (13) faces the air gap channel (2) or the extension line thereof.

2. The inner air-cooling structure of an electric machine bearing according to claim 1, wherein The front end of the rotor shaft (9) extends out of the front end cover (6), and the rear end is sealed in the rear cover.

3. The inner air-cooling structure of an electric machine bearing according to claim 1, wherein The inner port of the cooling air channel (13) is adjacent to and connected with the rotor air channel (4), the outer port of the cooling air channel (13) is located at the maximum outer diameter of the inner cooling fan (1), the outer port of the cooling air channel (13) is perpendicular to the extension line of the air gap channel (2), and the maximum diameter of the inner cooling fan (1) is smaller than the outer diameter of the rotor (10).

4. The inner air-cooling structure of an electric machine bearing according to claim 1, wherein The shell (5) is provided with a cooling water channel.

5. The inner air-cooling structure of an electric machine bearing according to claim 1, wherein The right end of the rotor air channel (4) faces the rear bearing (12).

6. The inner air-cooling structure of an electric machine bearing according to claim 1, wherein The front end cover (6) and the rear end cover (7) cover the front bearing (11) and the rear bearing (12) respectively.

7. The inner air-cooling structure of an electric machine bearing according to claim 1, wherein The front end of the rotor shaft (9) is a driving end, the driving end extends out of the front end cover (6) and drives a heat load; the inner cooling fan (1) is shrink-fitted on the rotor shaft (9) and close to the driving end, and the inner port of the cooling air channel (13) is located at the outer periphery of the rotor shaft (9).

8. The inner air-cooling structure of an electric machine bearing according to claim 1, wherein The inner cooling fan (1) is located between the rotor (10) and the front bearing (11).

9. The inner air-cooled structure of an electric machine bearing according to claim 1, wherein The right end of the rotor (10) is provided with a wind wing (3), and the wind wing (3) is located between the air gap channel (2) and the rotor air channel (4) in the radial direction.

10. The inner air-cooling structure of an electric machine bearing according to claim 1, wherein The rotor air channel (4) is annularly and uniformly distributed in the rotor (10).

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