High-speed motor with cooling air duct

Abstract

The utility model relates to a high-speed motor with a cooling air duct, which comprises a casing, a front end cover, a rear end cover, a stator and a rotor which are positioned inside the casing, a front bearing and a front bearing seat which are arranged on the rotor and are close to the front end cover, and a rear bearing and a rear bearing seat which are arranged on the rotor and are close to the rear end cover, bearing ventilation holes are formed in the front bearing seat and the rear bearing seat respectively, an air inlet pipe is arranged on the rear end cover, an air outlet pipe is arranged on the machine shell, a bypass air pipe is arranged on the outer side of the machine shell, an air inlet of the bypass air pipe is communicated with an inner cavity between the rear bearing and the rear end cover, and an air outlet of the bypass air pipe is communicated with an inner cavity between the front bearing and the front end cover. A through stator vent hole is formed in the stator in the axial direction, the air outlet pipe is located on the portion, between the front bearing and the stator, of the machine shell, and an air channel separation wall is arranged in the air outlet pipe. According to the utility model, the design of two cooling air ducts is adopted, thereby realizing a better cooling effect on the front bearing and the rear bearing, and facilitating the prolonging of the service life of the motor.

Description

Technical Field

[0001] This utility model relates to the field of motor technology, specifically to a high-speed motor with a cooling air duct. Background Technology

[0002] With the development of the motor industry, motor speeds are increasing and power densities are growing, making motor heat dissipation one of the most pressing issues to address. Motors with a front-end flange mounting structure suffer from relatively poor ventilation and cooling at the front bearing due to the compact structure. This difficulty in heat dissipation leads to increased bearing temperature, causing a rapid rise in motor temperature. This, in turn, affects the magnetic properties of the permanent magnets on the rotor. Higher temperatures can also cause changes in the magnetic properties of the permanent magnets, resulting in losses that cannot be restored even after remagnetization. Consequently, this affects the normal and safe operation of the motor and negatively impacts its lifespan. Therefore, it is necessary to optimize the cooling airflow of existing high-speed motors to reduce bearing temperature rise and extend motor lifespan. Utility Model Content

[0003] This utility model discloses a high-speed motor with a cooling air duct. By setting a bypass air duct outside the motor housing, the cold air blown into the housing from the air inlet can be divided into two paths, thereby achieving a better cooling effect on the inside of the motor.

[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0005] A high-speed motor with a cooling duct includes a housing, a front cover, a rear cover, a stator and a rotor located inside the housing, a front bearing and a front bearing housing mounted on the rotor near the front cover, and a rear bearing and a rear bearing housing mounted on the rotor near the rear cover. Bearing ventilation holes are respectively provided on the front bearing housing and the rear bearing housing. An air inlet pipe is provided on the rear cover, an air outlet pipe is provided on the housing, and a bypass pipe is provided on the outside of the housing. The air inlet of the bypass pipe connects to the inner cavity between the rear bearing and the rear cover, and the air outlet of the bypass pipe connects to the inner cavity between the front bearing and the front cover. A through stator ventilation hole is provided on the stator along the axial direction. The air outlet pipe is located on the housing between the front bearing and the stator, and an air duct isolation wall is provided in the air outlet pipe.

[0006] Furthermore, the air duct isolation wall includes a baffle plate, the bottom of which is integrally connected to the housing. The baffle plate divides the inner cavity of the air outlet pipe into a first air outlet chamber and a second air outlet chamber. The first air outlet chamber is located near the front end cover. The cold air blown into the housing from the air inlet pipe is divided into two airflows. One airflow passes through the rear bearing ventilation hole and enters the cavity at the rear end of the stator. Then, it flows into the cavity at the front end of the stator along the stator ventilation hole and the gap between the stator and rotor. Finally, it merges in the second air outlet chamber and flows out through the air outlet pipe. The other airflow is sent to the inner cavity at the front end of the front bearing through the bypass air pipe. Then, it flows into the first air outlet chamber through the front bearing ventilation hole and flows out through the air outlet pipe.

[0007] Furthermore, the rotor is also provided with a thrust disk and an axial thrust magnetic bearing for controlling the thrust disk. The axial thrust magnetic bearing is located between the front bearing and the stator. The bottom of the first air outlet cavity is closed. A ventilation hole for the first air outlet cavity is opened on the side wall of the first air outlet cavity. A limiting ring is formed on the inner wall of the housing below the first air outlet cavity. The axial thrust magnetic bearing is installed at the limiting ring. The ventilation hole for the first air outlet cavity is connected to the inner cavity at the front end of the axial thrust magnetic bearing.

[0008] Furthermore, an annular step is formed on the inner wall of the housing. The annular step is located on the side of the limiting ring near the front bearing. The inner diameter of the annular step is larger than the inner diameter of the limiting ring. A first air outlet ventilation hole is opened on the annular step along the axial direction.

[0009] This invention incorporates a cooling air duct inside the motor. A fan blows cold air into the casing to cool the interior. The air inlet is typically located near the rear end cover. The cold air enters the casing through the inlet, usually cooling the rear bearing first, then the stator and rotor, and finally the front bearing. However, in existing single-duct designs, the cold air reaches a relatively high temperature by the time it reaches the front bearing, resulting in poor cooling for the front bearing. This invention introduces a bypass duct on the outside of the casing, adding another air duct. This divides the cold air entering the casing from the inlet duct into two paths: one cools the rear bearing and the stator and rotor separately, while the other, through the bypass duct, directly cools the front bearing. Compared to existing cooling air duct designs, this invention provides significantly better cooling for the bearing, contributing to a longer motor lifespan. In addition, to prevent the two airflows with different air pressures and flow rates from interfering with each other, this utility model also sets up an air duct isolation wall at the air outlet, which separates the outflow paths of the two airflows. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the external structure of the high-speed motor in the embodiment;

[0011] Figure 2 This is a cross-sectional view of a high-speed motor;

[0012] Figure 3 This is a cross-sectional view of the high-speed motor from another direction.

[0013] Figure 4 This is a schematic diagram of the internal structure of a high-speed motor housing after the end caps have been removed.

[0014] Figure 5 This is a sectional view of the casing;

[0015] Figure 6 This is a cross-sectional view of the casing from another perspective.

[0016] Figure label:

[0017] 1. Housing; 2. Front cover; 3. Rear cover; 4. Inlet duct; 5. Outlet duct; 6. Bypass duct; 7. Rotor; 8. Stator; 9. Front bearing; 10. Rear bearing; 11. Stator ventilation hole; 12. Front bearing housing; 13. Rear bearing housing; 14. Baffle plate; 15. First outlet cavity; 16. Second outlet cavity; 17. Ventilation hole of the first outlet cavity; 18. Annular step; 19. Axial thrust magnetic bearing; 20. Limiting ring. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0019] This embodiment discloses a high-speed motor with cooling air ducts, mainly including a housing 1, end covers at both ends of the housing 1, and a stator 8 and a rotor 7 located inside the housing 1. For better description of the positional relationship, one end cover is referred to as the front end cover 2, and the other end cover is referred to as the rear end cover 3. Figure 1 As shown, an air inlet pipe 4 is provided on the rear cover 3, with the air inlet of the air inlet pipe 4 facing downwards. An air outlet pipe 5 is provided on the top of the housing 1 near the front cover 2, with the air outlet of the air outlet pipe 5 facing upwards. A bypass air duct 6 is also provided on the outside of the housing 1. Figures 2 to 4 As shown, a stator 8 is arranged on the outer circumference of the middle part of the rotor 7. Multiple through-holes 11 are formed along the axial direction around the edge of the stator 8. A front bearing 9 and a rear bearing 10 are respectively provided at both ends of the rotor 7. The front bearing 9 is mounted on a front bearing housing 12, and the rear bearing 10 is mounted on a rear bearing housing 13. Through-holes axially are formed on both the front bearing housing 12 and the rear bearing housing 13. A thrust disk and an axial thrust magnetic bearing 19 are also provided on the rotor between the front bearing 9 and the stator 8. The axial thrust magnetic bearing 19 controls the thrust disk with magnetic force, and the thrust disk provides axial thrust to limit the axial displacement of the rotor 7, preventing misalignment between the stator 8 and the rotor 7.

[0020] like Figure 3 As shown, the right end of the bypass duct 6 is the air inlet, and the left end is the air outlet. The air inlet of the bypass duct 6 connects to the inner cavity between the rear bearing 10 and the rear end cover 3, and the air outlet of the bypass duct 6 connects to the inner cavity between the front bearing 9 and the front end cover 2. In this embodiment, an external bypass duct 6 is used. The fan blows cold air into the housing 1 through the air inlet duct 4, which can be divided into two airflows, one of which is... Figure 3 As shown by the red arrow in the middle, the other path is... Figure 3 As shown by the blue arrow. The airflow path shown by the red arrow mainly cools the rear bearing 10, stator 8, and rotor 7. Figure 2 and Figure 3As shown, the cold air blown in from the air inlet duct 4 first enters the cavity between the rear bearing 10 and the rear end cover 3, and then flows into the cavity between the stator 8 and the rear bearing 10 along the rear bearing ventilation hole, first cooling the rear bearing 10. Then, it flows into the cavity between the axial thrust magnetic bearing 10 and the stator 8 through the stator ventilation hole 11 and the gap between the stator 8 and the rotor 7, thereby cooling the stator 8, rotor 7, and stator coils. Finally, it flows out of the casing 1 from the air outlet duct 5. The airflow path indicated by the blue arrow is as follows... Figure 3 As shown, one path of the cold air blown into the cavity between the rear bearing 10 and the rear end cover 3 directly enters the bypass duct 6 and is sent by the bypass duct 6 to the cavity between the front bearing 9 and the front end cover 2. This airflow does not cool the rear bearing 10, so the airflow temperature is low. This airflow passes through the front end of the front bearing 9 through the front bearing ventilation hole to cool the front bearing 9. The cooling effect is very good. The airflow after cooling the front bearing 9 flows directly out of the housing 1 from the air outlet duct 5.

[0021] In this embodiment, the cooling airflow is divided into two paths, but both converge and exit from the same outlet duct 5. To prevent airflow convection problems caused by interference between the two airflows with different air pressures and flow rates, an air duct isolation wall is installed in the outlet duct 5 to isolate the convergence point of the two airflows. The air duct isolation wall is formed directly on the housing 1 through integral molding, such as... Figure 5 and Figure 6 As shown, the air duct isolation wall mainly includes a baffle plate 14. The bottom of the baffle plate 14 is integrated with the housing 1. The baffle plate 14 divides the inner cavity of the air outlet pipe 5 into a first air outlet chamber 15 and a second air outlet chamber 16. The first air outlet chamber 15 is located near the front cover 2. The bottom of the first air outlet chamber 15 is closed. A ventilation hole 17 is opened at the bottom of the left side wall of the first air outlet chamber 15, allowing the airflow cooling the bearing 9 to flow into the first air outlet chamber 15 from the ventilation hole 17, and then out of the housing 1 through the air outlet pipe 5. Figure 6As shown, a limiting ring 20 is formed on the inner wall of the housing 1 below the first air outlet cavity 15. The axial thrust magnetic bearing 19 is installed at the limiting ring 20. An annular step 18 is formed on the inner wall of the housing 1 to the left of the limiting ring 20. The inner diameter of the annular step 18 is larger than the inner diameter of the limiting ring 20. A first air outlet cavity ventilation hole 17 is opened axially on the annular step 18 near the first air outlet cavity 15. One end of the first air outlet cavity ventilation hole 17 is connected to the inner cavity between the axial thrust magnetic bearing 19 and the front bearing 9, and the other end of the first air outlet cavity ventilation hole 17 is connected to the first air outlet cavity 15. Because the bottom of the first air outlet cavity 15 is closed, the axial thrust magnetic bearing 19 is tightly fitted with the limiting ring 20. The airflow flowing through the ventilation hole of the front bearing cannot flow directly into the lower part of the second air outlet cavity 16, but can only flow into the first air outlet cavity 15 through the first air outlet cavity ventilation hole 17. The bottom of the second air outlet chamber 16 is not closed, but directly connected to the inner cavity between the stator 8 and the axial thrust magnetic bearing 19, so that the airflow after cooling the stator and rotor can flow directly into the air outlet pipe 5 through the second air outlet chamber 16, and then flow out of the casing 1.

[0022] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-speed motor with a cooling duct, comprising a housing, a front cover, a rear cover, a stator and a rotor located inside the housing, a front bearing and a front bearing housing mounted on the rotor near the front cover, and a rear bearing and a rear bearing housing mounted on the rotor near the rear cover, wherein bearing ventilation holes are respectively provided on the front bearing housing and the rear bearing housing, characterized in that: An air inlet pipe is provided on the rear end cover, an air outlet pipe is provided on the housing, and a bypass air duct is provided on the outside of the housing. The air inlet of the bypass air duct connects to the inner cavity between the rear bearing and the rear end cover, and the air outlet of the bypass air duct connects to the inner cavity between the front bearing and the front end cover. A through stator ventilation hole is opened on the stator along the axial direction. The air outlet pipe is located on the housing between the front bearing and the stator, and an air duct isolation wall is provided in the air outlet pipe.

2. A high-speed motor with a cooling duct according to claim 1, characterized in that: The air duct isolation wall includes a baffle plate, the bottom of which is integrated with the casing. The baffle plate divides the inner cavity of the air outlet pipe into a first air outlet chamber and a second air outlet chamber. The first air outlet chamber is located near the front end cover. The cold air blown into the casing from the air inlet pipe is divided into two airflows. One airflow passes through the rear bearing ventilation hole and enters the cavity at the rear end of the stator. Then, it flows into the cavity at the front end of the stator through the stator ventilation hole and the gap between the stator and rotor. Finally, it merges in the second air outlet chamber and flows out through the air outlet pipe. The other airflow is sent to the inner cavity at the front end of the front bearing through the bypass air duct. Then, it flows into the first air outlet chamber through the front bearing ventilation hole and flows out through the air outlet pipe.

3. A high-speed motor with a cooling duct according to claim 2, characterized in that: The rotor is also equipped with a thrust disk and an axial thrust magnetic bearing for controlling the thrust disk. The axial thrust magnetic bearing is located between the front bearing and the stator. The bottom of the first air outlet cavity is closed. A ventilation hole for the first air outlet cavity is opened on the side wall of the first air outlet cavity. A limiting ring is formed on the inner wall of the housing below the first air outlet cavity. The axial thrust magnetic bearing is installed at the limiting ring. The ventilation hole for the first air outlet cavity is connected to the inner cavity at the front end of the axial thrust magnetic bearing.

4. A high-speed motor with a cooling duct according to claim 3, characterized in that: An annular step is formed on the inner wall of the housing. The annular step is located on the side of the limiting ring near the front bearing. The inner diameter of the annular step is larger than the inner diameter of the limiting ring. A first air outlet ventilation hole is opened on the annular step along the axial direction.

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