Motor cooling system and permanent magnet direct drive traction motor

Abstract

The utility model discloses a motor cooling system and a permanent magnet direct drive traction motor, and relates to the technical field of motor cooling. The motor cooling system comprises a rotating shaft, a rotor assembly, a stator assembly, a shell and end covers, and the end covers comprise a first end cover and a second end cover which are arranged at the two axial ends of the rotor assembly respectively; a first cavity is formed between the first end cover and the rotor assembly, a second cavity is formed between the second end cover and the rotor assembly, the rotor assembly is provided with a cooling air path, one end of the cooling air path is communicated with the first cavity, and the other end of the cooling air path is communicated with the second cavity; the first end cover is provided with an air inlet path used for being communicated with the first cavity, and the second end cover is provided with an air outlet path used for being communicated with the second cavity. Gas sequentially flows through the air inlet path, the first cavity, the cooling air path and the second cavity and flows out of the air outlet path. According to the utility model, a cooling mode of air cooling is adopted, so that the cooling device is suitable for cooling the rotor assembly of the low-speed and high-torque permanent magnet direct drive traction motor.

Description

Technical Field

[0001] The utility model relates to the technical field of motor cooling, and more specifically, to a motor cooling system. In addition, the utility model also relates to a permanent magnet direct drive traction motor including the motor cooling system. Background Art

[0002] As the core power component of heavy-duty freight locomotives, the traction motor adopts the drive structure of a high-efficiency permanent magnet direct-drive traction motor, which can eliminate the loss of gear transmission efficiency and improve the overall efficiency of the locomotive.

[0003] The stator copper loss ratio of low-speed, high-torque permanent magnet direct-drive traction motor is much higher than that of gear-driven traction motor. When the heat dissipation capacity of the locomotive and vehicle cooling system is limited, the stator winding temperature of the traction motor is high, and when the traction motor speed is low, it is difficult for the rotor magnet to exchange heat with the high-temperature stator or casing through the internal air, making it difficult to cool the rotor.

[0004] In addition, if liquid cooling is used, extremely high technical requirements will be placed on the bearing lubrication and its sealing structure. The bearing lubrication and sealing of existing low-speed, high-torque permanent magnet direct-drive traction motors do not meet the requirements, and the rotors cannot be liquid-cooled. The existing hybrid cooling and existing cooling methods of traction motors cannot meet the cooling requirements of low-speed, high-torque permanent magnet direct-drive traction motors.

[0005] In summary, how to provide a motor cooling system suitable for a low-speed, high-torque permanent magnet direct-drive traction motor is a problem that currently needs to be solved urgently by those skilled in the art. Utility Model Content

[0006] In view of this, the purpose of the utility model is to provide a motor cooling system, which can cool the rotor assembly by air cooling, reduce the requirements for the sealing structure of the bearing, and can be suitable for low-speed, high-torque permanent magnet direct-drive traction motors.

[0007] Another object of the utility model is to provide a permanent magnet direct drive traction motor including the motor cooling system.

[0008] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0009] A motor cooling system comprises a rotating shaft, a rotor assembly, a stator assembly, a housing and an end cover, wherein the rotor assembly is sleeved on the rotating shaft and located inside the stator assembly, the stator assembly is installed inside the housing, and the end cover comprises a first end cover and a second end cover respectively arranged at two axial ends of the rotor assembly;

[0010] A first chamber is formed between the first end cover and the rotor assembly, a second chamber is formed between the second end cover and the rotor assembly, the rotor assembly is provided with a cooling air path, and one end of the cooling air path is communicated with the first chamber, and the other end is communicated with the second chamber; the first end cover is provided with an air inlet for communicating with the first chamber, and the second end cover is provided with an air outlet for communicating with the second chamber;

[0011] The gas flows through the air inlet, the first chamber, the cooling air path, the second chamber in sequence, and flows out from the air outlet, thereby achieving air cooling and heat dissipation of the rotor assembly.

[0012] Optionally, the rotor assembly includes a rotor core and a magnetic steel embedded in the rotor core and extending along the axial direction of the rotor core, and the cooling air path is arranged in the rotor core.

[0013] Optionally, the cooling air passage includes a plurality of columnar through holes, the plurality of columnar through holes are evenly distributed along the circumference of the rotor core, and the columnar through holes penetrate the rotor core in the circumference of the rotor core.

[0014] Optionally, the air inlet is arranged at an upper portion of the first end cover, and the air outlet is arranged at a lower portion of the second end cover.

[0015] Optionally, the air inlet path includes a plurality of first channels communicating with the first chamber;

[0016] The air outlet path includes a plurality of second channels communicating with the second chamber.

[0017] Optionally, adjacent first channels are spaced apart;

[0018] The intervals between adjacent second channels are set.

[0019] Optionally, the shell is provided with a water channel, a water inlet communicated with the water channel, and a water outlet communicated with the water channel; the water channel extends along the axial direction of the shell.

[0020] Optionally, the shell includes an outer water jacket and an inner water jacket, the outer water jacket is arranged on the outside of the inner water jacket, and the chamber between the outer water jacket and the inner water jacket forms the water channel; the water inlet and the water outlet are both arranged on the outer water jacket.

[0021] Optionally, the first end cover is provided with a first extension portion and a second extension portion, the first extension portion is provided on a side of the first end cover facing the rotor assembly and extends in an axial direction of the rotating shaft toward the rotor assembly, and the second extension portion is provided on an inner side surface of the first end cover and extends in a radial direction of the rotating shaft toward the rotating shaft; the first extension portion, the second extension portion, the rotating shaft, and the rotor assembly are arranged to form the first chamber;

[0022] The second end cover is provided with a third extension portion and a fourth extension portion. The third extension portion is provided on a side of the second end cover facing the rotor assembly and extends along the axial direction of the rotating shaft toward the rotor assembly, and the fourth extension portion is provided on the inner side surface of the second end cover and extends along the radial direction of the rotating shaft toward the rotating shaft. The third extension portion, the fourth extension portion, the rotating shaft and the rotor assembly are arranged to form the second chamber.

[0023] A permanent magnet direct drive traction motor comprises any one of the motor cooling systems described above.

[0024] When using the motor cooling system provided by the utility model, gas is blown in through the air inlet of the first end cover, enters the cooling air path through the first chamber, enters the second chamber after flowing through the cooling air path, and is blown out through the air outlet of the second end cover. In the process of the gas flowing through the cooling air path, the gas exchanges heat with the rotor assembly, absorbs the heat of the rotor assembly, and realizes cooling of the rotor assembly.

[0025] Since the utility model adopts an air-cooling cooling method, the requirements for the sealing structure of the bearing can be reduced, and the utility model can be applied to the cooling of the rotor assembly of the low-speed, high-torque permanent magnet direct-drive traction motor.

[0026] In addition, the utility model also provides a permanent magnet direct drive traction motor including the above motor cooling system. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0028] Figure 1 A cross-sectional schematic diagram of a specific embodiment of the permanent magnet direct-drive traction motor provided by the utility model;

[0029] Figure 2 A cross-sectional schematic diagram of the permanent magnet direct-drive traction motor provided by the utility model in another direction;

[0030] Figure 3 This is a schematic diagram of the setting position of the first channel;

[0031] Figure 4 This is a schematic diagram of the setting position of the second channel.

[0032] Figure 1-Figure 4 middle:

[0033] 1 is a stator assembly, 11 is a stator core, 12 is a stator winding, 2 is a rotor assembly, 21 is a rotating shaft, 22 is a rotor core, 23 is a magnetic steel, 3 is a housing, 31 is a flange, 4 is a water channel, 41 is an outer water jacket, 42 is an inner water jacket, 43 is a water inlet, 44 is a water outlet, 51 is a first end cover, 52 is a second end cover, 61 is an air inlet, 611 is a first channel, 612 is an air inlet, 62 is an air outlet, 621 is a second channel, 63 is a cooling air path, 71 is a first chamber, 72 is a second chamber, 81 is a transmission end bearing, and 82 is a non-transmission end bearing. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0035] The core of the utility model is to provide a motor cooling system, which can cool the rotor assembly by air cooling, reduce the requirements for the sealing structure of the bearing, and can be suitable for low-speed, high-torque permanent magnet direct-drive traction motors.

[0036] Another core of the utility model is to provide a permanent magnet direct drive traction motor including the above motor cooling system.

[0037] Please refer to Figures 1 to 4 .

[0038] The present specific embodiment discloses a motor cooling system, including a rotating shaft 21, a rotor assembly 2, a stator assembly 1, a housing 3 and an end cover, wherein the rotor assembly 2 is sleeved on the rotating shaft 21 and located on the inner side of the stator assembly 1, the stator assembly 1 is installed on the inner side of the housing 3, and the end cover includes a first end cover 51 and a second end cover 52 respectively arranged at two axial ends of the rotor assembly 2; a first chamber 71 is formed between the first end cover 51 and the rotor assembly 2, and a second chamber 71 is formed between the second end cover 52 and the rotor assembly 2 2. The rotor assembly 2 is provided with a cooling air path 63, and one end of the cooling air path 63 is connected to the first chamber 71, and the other end is connected to the second chamber 72; the first end cover 51 is provided with an air inlet 61 for connecting to the first chamber 71, and the second end cover 52 is provided with an air outlet 62 for connecting to the second chamber 72; the gas flows through the air inlet 61, the first chamber 71, the cooling air path 63, the second chamber 72 in sequence, and flows out from the air outlet 62, so as to realize air cooling and heat dissipation of the rotor assembly 2.

[0039] It should be noted that the first chamber 71 and the second chamber 72 in this specific embodiment are not completely closed chambers, but relatively closed chambers. The sealing requirements between the first end cover 51 and the rotor assembly 2, and between the second end cover 52 and the rotor assembly 2 are not high. In actual use, after the gas enters the air inlet 61, it will enter the first chamber 71 under the action of air pressure. The air pressure in the first chamber 71 will continue to increase and decrease, causing at least part of the gas to enter the cooling air path 63 connected to the first chamber 71; under the action of air pressure, the gas flows out from the cooling air path 63 to the second chamber 72, and the air pressure in the second chamber 72 continues to increase, causing the gas to flow out from the air outlet 62.

[0040] When using the motor cooling system provided in this specific embodiment, gas is blown in through the air inlet 61 of the first end cover 51, enters the cooling air path 63 through the first chamber 71, enters the second chamber 72 after flowing through the cooling air path 63, and is blown out through the air outlet 62 of the second end cover 52. In the process of the gas flowing through the cooling air path 63, the gas exchanges heat with the rotor assembly 2, absorbs the heat of the rotor assembly 2, and realizes cooling of the rotor assembly 2.

[0041] Since air cooling is adopted in this specific embodiment, the requirements for the sealing structure of the bearing can be reduced. However, the sealing performance of the bearings of the low-speed, high-torque permanent magnet direct-drive traction motor is not high. Therefore, the motor cooling system in this specific embodiment can be applied to the cooling of the rotor assembly 2 of the low-speed, high-torque permanent magnet direct-drive traction motor.

[0042] In a specific embodiment, the rotor assembly 2 includes a rotor core 22 and a magnetic steel 23 embedded in the rotor core 22 and extending along the axial direction of the rotor core 22 . The cooling air path 63 is disposed in the rotor core 22 .

[0043] It should be noted that the cooling air passage 63 may be a non-bending air passage, or may be a bending air passage that does not affect the gas flow, which is determined according to actual conditions.

[0044] Specifically, the cooling air passage 63 may include a plurality of columnar through holes, the plurality of columnar through holes are evenly distributed along the circumference of the rotor core 22 , and the columnar through holes penetrate the rotor core 22 in the circumference of the rotor core 22 .

[0045] Further, if Figure 2 As shown, the cooling air path 63 can be set as a cylindrical through hole extending along the axial direction of the rotating shaft 21, and multiple cooling air paths 63 are evenly distributed along the circumference of the rotor core 22. Of course, the cooling air path 63 can also be set as an air path of other shapes, which is determined according to actual conditions and will not be described in detail here.

[0046] In this specific embodiment, a plurality of columnar through holes are evenly distributed along the circumference of the rotor core 22 , so that all parts of the rotor assembly 2 can be evenly cooled.

[0047] In a specific embodiment, if Figure 3 As shown, the air inlet 61 is disposed at an upper portion of the first end cover 51, and the air inlet 61 has an air inlet 612, as shown in FIG. Figure 4 As shown, the air outlet 62 is disposed at a lower portion of the second end cover 52 .

[0048] The upper position of the first end cover 51 mentioned in this specific embodiment refers to a position above the middle position of the first end cover 51 , and the lower position of the second end cover 52 refers to a position below the middle position of the second end cover 52 .

[0049] Specifically, the air inlet passage 61 may include a plurality of first channels 611 communicating with the first chamber 71 , and the air outlet passage 62 may include a plurality of second channels 621 communicating with the second chamber 72 .

[0050] Specifically, the first channel 611 and the second channel 621 may be configured as fan-shaped channels, or channels in a rectangular, square, columnar or other shape, depending on actual conditions.

[0051] Furthermore, adjacent first channels 611 may be spaced apart; further, the spacing angles between adjacent first channels 611 may be the same, and of course, the spacing angles between adjacent first channels 611 may also be different, depending on the actual situation; adjacent second channels 621 may be spaced apart; further, the spacing angles between adjacent second channels 621 may be the same, and of course, the spacing angles between adjacent second channels 621 may also be different, depending on the actual situation.

[0052] It should be noted that in this specific embodiment, the angle occupied by the air inlet 61 in the circumferential direction of the first end cover 51 is less than or equal to 180 degrees, which can be determined according to actual conditions. The angle occupied by the air outlet 62 in the circumferential direction of the second end cover 52 is less than or equal to 180 degrees, which can be determined according to actual conditions.

[0053] In this specific embodiment, the air inlet 61 is arranged at the upper part of the first end cover 51 and connected to the cooling system of the locomotive or vehicle, which can facilitate the entry of gas into the air inlet 61; the air outlet 62 is arranged at the lower part of the second end cover 52 to prevent impurities in the air from entering the interior of the motor.

[0054] In addition, filter screens may be provided at both the air inlet 612 of the air inlet path 61 and the air outlet of the air outlet path 62 to prevent impurities from entering the interior of the motor.

[0055] In a specific embodiment, if Figure 1 As shown, the housing 3 is provided with a water channel 4 , a water inlet 43 communicating with the water channel 4 , and a water outlet 44 communicating with the water channel 4 ; the water channel 4 extends along the axial direction of the housing 3 .

[0056] Specifically, the stator assembly 1 is inserted into the inner side of the housing 3. The stator assembly 1 includes a stator core 11 and a stator winding 12. The housing 3 includes an outer water jacket 41, an inner water jacket 42, and two flanges 31. Figure 2 As shown, the outer water jacket 41 is sleeved on the outside of the inner water jacket 42 , and the chamber between the outer water jacket 41 and the inner water jacket 42 forms a water channel 4 ; the water inlet 43 and the water outlet 44 are both arranged on the outer water jacket 41 .

[0057] In actual settings, you can Figure 2 As shown, the inner water jacket 42 completely wraps the stator core 11 along the circumferential direction, and the outer water jacket 41 forms a cavity with the inner water jacket 42 along the circumferential direction to form a water channel 4, and the water channel 4 is distributed in part of the circumference to avoid the installation of other components; of course, the outer water jacket 41 can also form a cavity with the inner water jacket 42 along the circumferential direction to form the water channel 4, and the water channel 4 is distributed in the entire circumference, which is determined according to actual conditions.

[0058] In a specific embodiment, if Figure 1As shown, a transmission end bearing 81 is provided at one end of the rotating shaft 21, and a non-transmission end bearing 82 is provided at the other end, and the transmission end bearing 81 is located on the outside of the second end cover 52, and the non-transmission end bearing 82 is located on the outside of the first end cover 51; the first end cover 51 is provided with a first extension portion and a second extension portion, the first extension portion is provided on one side of the first end cover 51 facing the rotor assembly 2 and extends along the axial direction of the rotating shaft 21 in a direction close to the rotor assembly 2 until the first extension portion contacts the rotor assembly 2, or until a narrow gap is formed between the first extension portion and the rotor assembly 2 that does not affect the rotation of the rotor assembly 2; the second extension portion is provided on the inner side surface of the first end cover 51 and extends along the radial direction of the rotating shaft 21 in a direction close to the rotating shaft 21 until the second extension portion contacts the rotating shaft 21, or until a narrow gap is formed between the second extension portion and the rotating shaft 21 that does not affect the rotation of the rotating shaft 21; the first extension portion, the second extension portion, the rotating shaft 21, and the rotor assembly 2 are surrounded to form a first chamber 71;

[0059] The second end cover 52 is provided with a third extension portion and a fourth extension portion. The third extension portion is provided in the second end cover 52 on one side facing the rotor assembly 2 and extends along the axial direction of the rotating shaft 21 toward the rotor assembly 2 until the third extension portion contacts the rotor assembly 2, or until a narrow gap is provided between the third extension portion and the rotor assembly 2 that does not affect the rotation of the rotor assembly 2; the fourth extension portion is provided on the inner side surface of the second end cover 52 and extends along the radial direction of the rotating shaft 21 toward the rotor assembly 21 until the fourth extension portion contacts the rotating shaft 21, or until a narrow gap is provided between the fourth extension portion and the rotating shaft 21 that does not affect the rotation of the rotating shaft 21; the third extension portion, the fourth extension portion, the rotating shaft 21, and the rotor assembly 2 are arranged to form a second chamber 72.

[0060] In this specific embodiment, the sealing performance of the first chamber 71 is improved by providing the first extension part and the second extension part, and the sealing performance of the second chamber 72 is improved by providing the third extension part and the fourth extension part. Although the first chamber 71 and the second chamber 72 cannot be strictly sealed, after the relative sealing effect is improved, as much gas as possible can enter the cooling air path 63, and the gas flowing out of the cooling air path 63 can also be better concentrated and discharged.

[0061] In addition to the above-mentioned motor cooling system, the present invention also provides a permanent magnet direct-drive traction motor including the motor cooling system disclosed in the above-mentioned embodiment. For the structures of other parts of the permanent magnet direct-drive traction motor, please refer to the prior art and will not be described in detail herein.

[0062] Each embodiment in this specification is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referenced to each other. Any combination of all embodiments provided by the utility model is within the protection scope of this utility model and will not be described in detail here.

[0063] The motor cooling system and permanent magnet direct drive traction motor provided by the utility model are introduced in detail above. Specific examples are used in this article to illustrate the principle and implementation method of the utility model. The description of the above embodiments is only used to help understand the method and core idea of ​​the utility model. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the utility model, the utility model can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the utility model.

Claims

1. A motor cooling system, characterized in that: The invention comprises a rotating shaft (21), a rotor assembly (2), a stator assembly (1), a housing (3) and an end cover, wherein the rotor assembly (2) is sleeved on the rotating shaft (21) and located on the inner side of the stator assembly (1), the stator assembly (1) is mounted on the inner side of the housing (3), and the end cover comprises a first end cover (51) and a second end cover (52) which are respectively arranged at two axial ends of the rotor assembly (2); A first chamber (71) is formed between the first end cover (51) and the rotor assembly (2), and a second chamber (72) is formed between the second end cover (52) and the rotor assembly (2); the rotor assembly (2) is provided with a cooling air passage (63), and one end of the cooling air passage (63) is in communication with the first chamber (71), and the other end is in communication with the second chamber (72); the first end cover (51) is provided with an air inlet passage (61) for communicating with the first chamber (71), and the second end cover (52) is provided with an air outlet passage (62) for communicating with the second chamber (72); The gas flows sequentially through the air inlet passage (61), the first chamber (71), the cooling air passage (63), the second chamber (72), and flows out from the air outlet passage (62), thereby achieving air cooling and heat dissipation for the rotor assembly (2).

2. The motor cooling system according to claim 1, characterized in that: The rotor assembly (2) comprises a rotor core (22) and a magnetic steel (23) embedded in the rotor core (22) and extending along the axial direction of the rotor core (22); the cooling air path (63) is arranged on the rotor core (22).

3. The motor cooling system according to claim 2, characterized in that: The cooling air passage (63) comprises a plurality of columnar through holes, the plurality of columnar through holes being evenly distributed along the circumference of the rotor core (22), and the columnar through holes penetrating the rotor core (22) in the circumference of the rotor core (22).

4. The motor cooling system according to claim 1, characterized in that: The air inlet passage (61) is arranged at an upper portion of the first end cover (51), and the air outlet passage (62) is arranged at a lower portion of the second end cover (52).

5. The motor cooling system according to claim 2, characterized in that: The air inlet path (61) comprises a plurality of first channels (611) communicating with the first chamber (71); The air outlet passage (62) comprises a plurality of second channels (621) communicating with the second chamber (72).

6. The motor cooling system according to claim 5, characterized in that: The spacing between adjacent first channels (611); The intervals between adjacent second channels (621) are set.

7. The motor cooling system according to any one of claims 1 to 6, characterized in that: The shell (3) is provided with a water channel (4), a water inlet (43) connected to the water channel (4), and a water outlet (44) connected to the water channel (4); the water channel (4) extends along the axial direction of the shell (3).

8. The motor cooling system according to claim 7, characterized in that: The shell (3) comprises an outer water jacket (41) and an inner water jacket (42); the outer water jacket (41) is sleeved on the outside of the inner water jacket (42); a chamber between the outer water jacket (41) and the inner water jacket (42) forms the water channel (4); and the water inlet (43) and the water outlet (44) are both arranged on the outer water jacket (41).

9. The motor cooling system according to any one of claims 1 to 6, characterized in that: The first end cover (51) is provided with a first extension portion and a second extension portion, wherein the first extension portion is provided on a side of the first end cover (51) facing the rotor assembly (2) and extends in an axial direction of the rotating shaft (21) in a direction close to the rotor assembly (2), and the second extension portion is provided on an inner side surface of the first end cover (51) and extends in a radial direction of the rotating shaft (21) in a direction close to the rotating shaft (21); the first extension portion, the second extension portion, the rotating shaft (21) and the rotor assembly (2) are arranged to form the first chamber (71); The second end cover (52) is provided with a third extension portion and a fourth extension portion, wherein the third extension portion is provided on a side of the second end cover (52) facing the rotor assembly (2) and extends along the axial direction of the rotating shaft (21) in a direction close to the rotor assembly (2), and the fourth extension portion is provided on the inner side surface of the second end cover (52) and extends along the radial direction of the rotating shaft (21) in a direction close to the rotating shaft (21); the third extension portion, the fourth extension portion, the rotating shaft (21) and the rotor assembly (2) are arranged to form the second chamber (72).

10. A permanent magnet direct drive traction motor, characterized in that: A motor cooling system comprising any one of claims 1-9.

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