A rotor and bearing chamber cooling structure for a permanent magnet direct drive motor

Abstract

The application relates to the technical field of permanent magnet direct drive motors, in particular to a rotor and bearing chamber cooling structure of a permanent magnet direct drive motor, which aims to solve the problem of how to realize the air gap sealing of the permanent magnet direct drive motor and improve the cooling effect of the rotor and the bearing chamber, and provides a new rotor and bearing chamber cooling structure of a permanent magnet direct drive motor, which comprises a rotor, a stator, a left end cover, a right end cover, a left bearing chamber and a right bearing chamber, the rotor comprises a rotating shaft, a rotor iron core and permanent magnets, the rotating shaft is a hollow shaft, and the rotating shaft is provided with a left air inlet and a right air inlet, the left end cover and the right end cover are respectively provided with a left air outlet and a right air outlet, a left fan is fixed on a left rotor pressing ring, the outer ring of the left air outlet of the left end cover extends to the inside and forms a labyrinth sealing structure with the outer ring of the left fan, a right fan is arranged on a right rotor pressing ring, and the outer ring of the right air outlet of the right end cover extends to the inside and forms a labyrinth sealing structure with the outer ring of the right fan; the structure is simple and the technical problem is solved.

Description

Technical Field

[0001] This invention relates to the field of permanent magnet direct drive motor technology, specifically to a rotor and bearing housing cooling structure for a permanent magnet direct drive motor. Background Technology

[0002] Permanent magnet motors are characterized by their small size, light weight, and high power density. To ensure normal operation, they are typically designed with a fully enclosed structure to prevent magnetic dust from adsorbing into the air gap. The air-cooling structure of a permanent magnet motor usually involves a fully enclosed design for both the air gap and the rotor. For example, a cooling structure for a permanent magnet motor disclosed in CN110768414A proposes an airflow structure with air passages in the stator yoke, outside the stator, and in the rotor yoke, forming an external stator ventilation cooling and an internal rotor circulation ventilation cooling structure. However, because the rotor and bearing housing cannot directly exchange heat with the outside environment via convection, the cooling effect of the rotor and bearing housing is not ideal. Summary of the Invention

[0003] In order to solve the problem of how to improve the cooling effect of the rotor and bearing chamber while achieving air gap sealing in a permanent magnet direct drive motor, this invention provides a new cooling structure for the rotor and bearing chamber of a permanent magnet direct drive motor. This invention is achieved using the following technical solution: a bearing cooling structure for a permanent magnet direct drive motor, comprising a rotor, a stator, a left end cover, a right end cover, a left bearing chamber, and a right bearing chamber. The rotor includes a shaft, a rotor core, and permanent magnets. A left permanent magnet baffle and a right permanent magnet baffle are respectively provided at both ends of the rotor core. A left rotor retaining ring and a right rotor retaining ring are respectively provided at both ends of the rotor yoke. The shaft is a hollow shaft, and the portion of the shaft located between the left bearing chamber and the left rotor retaining ring, and the portion located between the right bearing chamber and the right rotor retaining ring, are respectively provided with a left air inlet and a right air inlet. The air vents are provided on the left and right end covers respectively. A left fan is fixed on the left rotor pressure ring. The outer ring of the left air outlet of the left end cover extends inward and forms a labyrinth seal structure with the outer ring of the left fan. The left air inlet, the inner ring of the left end cover, the left air outlet, and the left fan form the cooling air path for the left bearing chamber. A right fan is provided on the right rotor pressure ring. The outer ring of the right air outlet of the right end cover extends inward and forms a labyrinth seal structure with the outer ring of the right fan. The right air inlet, the inner ring of the right end cover, the right fan, and the right air outlet form the cooling air path for the right bearing chamber.

[0004] In use, the shaft is mounted in a frame-suspended manner, and the shaft is directly connected to the wheelset. During cooling, one cooling air path is as follows: cooling air (since the shaft in this application is a hollow shaft, the cooling air in this application enters from both ends of the shaft) enters from the right air inlet of the shaft, passes through the right fan, and exits from the right air outlet of the right end cover, thereby carrying away the heat generated in the right bearing chamber and achieving cooling of the right bearing chamber; the other cooling air path is as follows: cooling air enters from the left air inlet of the shaft, passes through the left fan, and exits from the left air outlet of the left end cover, thereby carrying away the heat generated in the left bearing chamber and achieving cooling of the left bearing chamber.

[0005] A rotor cooling structure for a permanent magnet direct drive motor includes a rotor, a stator, a left end cover, a right end cover, a left bearing chamber, and a right bearing chamber. The rotor includes a shaft, a rotor core, and permanent magnets. A left permanent magnet baffle and a right permanent magnet baffle are respectively provided at both ends of the rotor core. A left rotor retaining ring and a right rotor retaining ring are respectively provided at both ends of the rotor yoke. The shaft is a hollow shaft with a left shaft air inlet and a right shaft air inlet in the middle. A left air outlet and a right air outlet are respectively provided on the left and right end covers. A left axial ventilation hole and a right axial ventilation hole are respectively provided on the left and right halves of the rotor yoke. A left retaining ring ventilation hole communicating with the left axial ventilation hole is provided on the left rotor retaining ring, and a right retaining ring ventilation hole communicating with the right rotor ventilation hole is provided on the right rotor retaining ring. The left shaft air inlet is connected to a left radial connection on the rotor. The connecting hole is connected to the left axial ventilation hole, and the right shaft ventilation port is connected to the right axial ventilation hole through the right radial connecting hole on the rotor. A left fan is fixed on the outer end face of the left rotor pressure ring. The outer ring of the left air outlet of the left end cover extends inward and forms a labyrinth seal structure with the outer ring of the left fan. A right fan is provided on the outer end face of the right rotor pressure ring. The outer ring of the right air outlet of the right end cover extends inward and forms a labyrinth seal structure with the outer ring of the right fan. The left shaft air inlet, left radial connecting hole, left axial ventilation hole, left pressure ring ventilation hole, left fan, and left air outlet form the cooling air path for the left half of the rotor. The right shaft air inlet, right radial connecting hole, right axial ventilation hole, right pressure ring ventilation hole, right fan, and right air outlet form the cooling air path for the right half of the rotor, thereby achieving rotor cooling.

[0006] A rotor and bearing cooling structure for a permanent magnet direct drive motor includes a rotor, a stator, a left end cover, a right end cover, a left bearing chamber, and a right bearing chamber. The rotor includes a shaft, a rotor core, and permanent magnets. A left permanent magnet baffle and a right permanent magnet baffle are respectively provided at both ends of the rotor core. A left rotor retaining ring and a right rotor retaining ring are respectively provided at both ends of the rotor yoke. The shaft is a hollow shaft. A left air outlet and a right air outlet are respectively provided on the left and right end covers. A left fan is provided between the left rotor retaining ring and the left bearing chamber. The left fan includes a left fan bracket fixed to the shaft and a fan housing located on the left fan housing. The left bearing fan blades on the outer side of the frame, the outer ring of the left air outlet on the left end cover extends inward and forms a labyrinth seal structure with the outer ring of the outer end of the left fan bracket. A left air inlet is located on the shaft between the left bearing chamber and the outer end of the left fan bracket. The left air inlet, the outer side of the left fan bracket, and the left air outlet form the cooling airflow path for the left bearing. The outer ring of the inner end of the left fan bracket is statically sealed to the left permanent magnet baffle. The rotor core has rotor axial ventilation holes, and the left permanent magnet baffle has left baffle ventilation holes that communicate with the rotor axial ventilation holes. The shaft, located between the inner end of the left fan bracket and the left rotor pressure ring, has a rotor air outlet. The right permanent magnet baffle has a right baffle ventilation hole communicating with the rotor axial ventilation hole. A right fan is located between the right rotor pressure ring and the right bearing chamber. The right fan includes a right fan bracket fixed to the shaft, and rotor blades and right bearing blades located on the inner and outer sides of the right fan bracket, respectively. The outer ring of the inner end of the right fan bracket is statically sealed to the right permanent magnet baffle. The shaft, located between the inner end of the right rotor pressure ring and the right fan bracket, has a rotor air inlet. The air inlet, right baffle ventilation hole, rotor axial ventilation hole, left baffle ventilation hole, and rotor air outlet form the cooling air path of the rotor. The part of the shaft located between the right bearing chamber and the outer end of the right fan bracket is provided with a right air inlet. The outer ring of the right air outlet of the right end cover extends inward and forms a labyrinth seal structure with the outer ring of the outer end of the right fan bracket. The right air inlet, right fan, and right air outlet form the cooling air path of the right bearing (for ease of description, the inner and outer sides mentioned in this application refer to the inner and outer sides in the axial direction, and the inner ring and outer ring refer to the inner and outer sides in the radial direction).

[0007] The beneficial effects of this invention are as follows: By employing a hollow shaft design and breaking with convention by incorporating an air inlet on the hollow shaft, this invention achieves direct heat exchange between the permanent magnet motor bearings and rotor and the external environment. This satisfies the requirement for a sealed air gap in permanent magnet direct drive motors, avoiding the safety hazard of dust adsorption in the air gap between the stator and rotor, while effectively improving the heat dissipation capacity of the rotor and bearing chamber. The invention has a simple structure and is easy to implement, resulting in significant improvements in the rotor and bearing performance. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of the structure of Embodiment 1; Figure 2This is a schematic diagram of the structure of Example 2; Figure 3 This is a schematic diagram of the structure of Example 3; Figure 4 This is an enlarged structural diagram of the combined fan.

[0009] In the diagram: 1—Stator, 2—Rotor, 3—Left end cover, 4—Right end cover, 5—Left bearing chamber, 6—Right bearing chamber, 7—Left permanent magnet baffle, 8—Right permanent magnet baffle, 9—Left rotor pressure ring, 10—Right rotor pressure ring, 11—Shaft, 12—Left air inlet, 13—Right air inlet, 14—Left air outlet, 15—Right air outlet, 16—Left fan, 17—Right fan, 18—Left axial ventilation hole, 19—Right... Axial ventilation hole, 20—left pressure ring ventilation hole, 21—right pressure ring ventilation hole, 22—left shaft air inlet, 23—right shaft air inlet, 24—left radial connection hole, 25—right radial connection hole, 26—left bearing fan blade, 27—right bearing fan blade, 28—rotor fan blade, 29—rotor air inlet, 30—left baffle ventilation hole, 31—right baffle ventilation hole, 32—rotor axial ventilation hole, 33—rotor air outlet. Detailed Implementation

[0010] Example 1: As Figure 1 As shown, a bearing cooling structure for a permanent magnet direct drive motor includes a rotor 2, a stator 1, a left end cover 3, a right end cover 4, a left bearing chamber 5, and a right bearing chamber 6. The rotor 2 includes a shaft 11, a rotor core, and permanent magnets. A left permanent magnet baffle 7 and a right permanent magnet baffle 8 are respectively provided at both ends of the rotor core. A left rotor retaining ring 9 and a right rotor retaining ring 10 are respectively provided at both ends of the rotor 2 yoke. The shaft 11 is a hollow shaft, and the portion of the shaft 11 between the left bearing chamber 5 and the left rotor retaining ring 9, and the portion between the right bearing chamber 6 and the right rotor retaining ring 10, are respectively provided with a left air inlet 12 and a right air inlet 13. The left end cover 3, right end cover 4, left bearing chamber 5, and right bearing chamber 6 are respectively provided with a left air inlet 12 and a right air inlet 13. The cover 4 is provided with a left air outlet 14 and a right air outlet 15 respectively. A left fan 16 is fixed on the left rotor pressure ring 9. The outer ring of the left air outlet 14 of the left end cover 3 extends inward and forms a labyrinth seal structure with the outer ring of the left fan 16. The left air inlet 12, the inner ring of the left end cover 3, the left air outlet 14, and the left fan 16 form a cooling air path for the left bearing chamber. A right fan 17 is provided on the right rotor pressure ring 10. The outer ring of the right air outlet 15 of the right end cover 4 extends inward and forms a labyrinth seal structure with the outer ring of the right fan 17. The right air inlet 13, the inner ring of the right end cover 4, the right fan 17, and the right air outlet 15 form a cooling air path for the right bearing chamber.

[0011] During cooling, one cooling air path is as follows: cooling air (since the rotating shaft 11 in this application is a hollow shaft, the cooling air in this application enters from both ends of the rotating shaft 11) enters from the right air inlet 13 of the rotating shaft 11, passes through the right fan 17, and is discharged from the right air outlet 15 of the right end cover 4, thereby carrying away the heat generated by the right bearing chamber 6 and achieving cooling of the right bearing chamber 6; the other cooling air path is as follows: cooling air enters from the left air inlet 12 of the rotating shaft 11, passes through the left fan 16, and is discharged from the left air outlet 14 of the left end cover 3, thereby carrying away the heat generated by the left bearing chamber 5 and achieving cooling of the left bearing chamber 5.

[0012] In practice, the inner ring of the left fan 16 is connected to the left rotor pressure ring 9 by bolts. The inner ring of the right fan 17 is connected to the right rotor pressure ring 10 by bolts.

[0013] Example 2: Figure 2 As shown, a rotor 2 cooling structure for a permanent magnet direct drive motor includes a rotor 2, a stator 1, a left end cover 3, a right end cover 4, a left bearing chamber 5, and a right bearing chamber 6. The rotor 2 includes a shaft 11, a rotor core, and permanent magnets. A left permanent magnet baffle 7 and a right permanent magnet baffle 8 are respectively provided at both ends of the rotor core. A left rotor retaining ring 9 and a right rotor retaining ring 10 are respectively provided at both ends of the yoke of the rotor 2. The shaft 11 is a hollow shaft, and a left shaft air inlet 22 and a right shaft air inlet 20 are provided in the middle of the shaft 11. The rotor 2 has an air inlet 23, a left air outlet 14 on the left end cover 3, and a right air outlet 15 on the right end cover 4. The left and right halves of the rotor 2 yoke are respectively provided with a left axial ventilation hole 18 and a right axial ventilation hole 19. The left rotor pressure ring 9 is provided with a left pressure ring ventilation hole 20 that communicates with the left axial ventilation hole 18, and the right rotor pressure ring 10 is provided with a right pressure ring ventilation hole 21 that communicates with the right rotor 2 ventilation hole. The left rotor air inlet 22 is connected to the left radial connection on the rotor 2. Hole 24 communicates with the left axial ventilation hole 18. The ventilation port of the right rotating shaft 11 communicates with the right axial ventilation hole 19 through the right radial connection hole 25 provided on the rotor 2. A left fan 16 is fixed on the outer end face of the left rotor pressure ring 9. The outer ring of the left air outlet 14 of the left end cover 3 extends inward and forms a labyrinth seal structure with the outer ring of the left fan 16. A right fan 17 is provided on the outer end face of the right rotor pressure ring 10. The outer ring of the right air outlet 15 of the right end cover 4 extends inward and forms a labyrinth seal structure with the right fan 17. The outer ring of fan 17 forms a labyrinth seal structure. The left shaft air inlet 22, left radial connection hole 24, left axial ventilation hole 18, left pressure ring ventilation hole 20, left fan 16, and left air outlet 14 form the cooling air path for the left half of rotor 2. The right shaft air inlet 23, right radial connection hole 25, right axial ventilation hole 19, right pressure ring ventilation hole 21, right fan 17, and right air outlet 15 form the cooling air path for the right half of rotor 2, thereby achieving the cooling of rotor 2.

[0014] In practice, the inner ring of the left fan 16 is connected to the left rotor pressure ring 9 by bolts. The inner ring of the right fan 17 is connected to the right rotor pressure ring 10 by bolts. There are multiple left shaft air inlets 22, which are evenly distributed around the shaft 11, and multiple right shaft air inlets 23, which are also evenly distributed around the shaft 11.

[0015] Example 3: Figure 3 and Figure 4 As shown, a rotor and bearing cooling structure for a permanent magnet direct drive motor includes a rotor 2, a stator 1, a left end cover 3, a right end cover 4, a left bearing chamber 5, and a right bearing chamber 6. The rotor 2 includes a shaft 11, a rotor core, and permanent magnets. A left permanent magnet baffle 7 and a right permanent magnet baffle 8 are respectively provided at both ends of the rotor core. A left rotor retaining ring 9 and a right rotor retaining ring 10 are respectively provided at both ends of the yoke of the rotor 2. The shaft 11 is a hollow shaft. A left air outlet 14 and a right air outlet 15 are respectively provided on the left end cover 3 and the right end cover 4. A left fan 16 is provided between the left rotor retaining ring 9 and the left bearing chamber 5. The left fan includes a left fan bracket fixed to the shaft. (In specific implementation, the cross-section of the left fan bracket is Y-shaped) and the left bearing fan blade 26 is located on the outside of the left fan bracket. The outer ring of the left air outlet of the left end cover 3 extends inward and forms a labyrinth seal structure with the outer ring of the outer end of the left fan bracket. The part of the shaft located between the left bearing chamber 5 and the outer end of the left fan bracket is provided with a left air inlet 12. The left air inlet 12, the outer side of the left fan bracket, and the left air outlet 14 form the cooling air path of the left bearing chamber. The outer ring of the inner end of the left fan bracket is statically sealed to the left permanent magnet baffle 7. The rotor core is provided with rotor axial ventilation holes 32, and the left permanent magnet baffle 7 is provided with A left baffle ventilation hole 30 communicates with the rotor axial ventilation hole 32. A rotor air outlet 33 is provided on the part of the shaft located between the inner end of the left fan bracket and the left rotor pressure ring 9. A right baffle ventilation hole 31 communicating with the rotor axial ventilation hole 32 is provided on the right permanent magnet baffle 8. A right fan is provided between the right rotor pressure ring 10 and the right bearing chamber 6. The right fan includes a right fan bracket fixed to the shaft 11 (in specific implementation, the cross-section of the right fan bracket is Y-shaped) and rotor fan blades 28 and right bearing fan blades 27 located on the inner and outer sides of the right fan bracket, respectively. The outer ring of the inner end of the right fan bracket is statically sealed to the right permanent magnet baffle 8. The shaft 11 is connected in a sealed manner. The part between the right rotor pressure ring 10 and the inner end of the right fan bracket is provided with a rotor air inlet 29. The rotor air inlet 29, the right baffle ventilation hole 31, the rotor axial ventilation hole 32, the left baffle ventilation hole 30, and the rotor air outlet 33 form the cooling air path of the rotor. The part of the shaft 11 between the right bearing chamber 6 and the outer end of the right fan bracket is provided with a right air inlet 13. The outer ring of the right air outlet 15 of the right end cover 4 extends inward and forms a labyrinth seal structure with the outer ring of the outer end of the right fan bracket. The right air inlet 13, the right fan, and the right air outlet 15 form the cooling air path of the right bearing.

[0016] In specific implementation, there are multiple rotor air inlets 29 and rotor air outlets 33, which are evenly distributed circumferentially on the circumferential surface of the rotating shaft 11. There are multiple axial ventilation holes, left baffle ventilation holes 30 and right baffle ventilation holes 31, which are evenly distributed circumferentially on the rotor core 2.

Claims

1. A rotor and bearing cooling structure for a permanent magnet direct drive motor, comprising a rotor (2), a stator (1), a left end cover (3), a right end cover (4), a left bearing chamber (5), and a right bearing chamber (6), wherein the rotor (2) comprises a shaft (11), a rotor core, and permanent magnets, and a left permanent magnet baffle (7) and a right permanent magnet baffle (8) are respectively provided at both ends of the rotor core, and a left rotor pressure ring (9) and a right rotor pressure ring (10) are respectively provided at both ends of the yoke of the rotor (2), characterized in that, The rotating shaft (11) is a hollow shaft. The left end cover (3) and the right end cover (4) are respectively provided with a left air outlet (14) and a right air outlet (15). A left fan (16) is provided between the left rotor pressure ring (9) and the left bearing chamber (5). The left fan includes a left fan bracket fixed to the rotating shaft and a left bearing fan blade (26) located outside the left fan bracket. The cross-section of the left fan bracket is Y-shaped. The outer ring of the left air outlet of the left end cover (3) extends inward and forms a labyrinth seal structure with the outer ring of the outer end of the left fan bracket. The rotating shaft is located between the left bearing chamber (5) and the left fan bracket. A left air inlet (12) is provided between the side ends. The left air inlet (12), the outer end of the left fan bracket, and the left air outlet (14) form the cooling air path of the left bearing chamber. The outer ring of the inner end of the left fan bracket is statically sealed to the left permanent magnet baffle (7). The rotor core is provided with a rotor axial ventilation hole (32). The left permanent magnet baffle (7) is provided with a left baffle ventilation hole (30) that communicates with the rotor axial ventilation hole (32). The part of the shaft located between the inner end of the left fan bracket and the left rotor pressure ring (9) is provided with a rotor air outlet (33). The right permanent magnet baffle (8) The rotor (11) has a right baffle ventilation hole (31) that communicates with the rotor axial ventilation hole (32). A right fan is provided between the right rotor pressure ring (10) and the right bearing chamber (6). The right fan includes a right fan bracket fixed to the rotating shaft (11) and rotor fan blades (28) and right bearing fan blades (27) located on the inner and outer sides of the right fan bracket, respectively. The cross-section of the right fan bracket is Y-shaped. The outer ring of the inner end of the right fan bracket is statically sealed to the right permanent magnet baffle (8). The part of the rotating shaft (11) located between the inner end of the right rotor pressure ring (10) and the right fan bracket has a rotor air inlet. The rotor air inlet (29), the left baffle ventilation hole (30), the rotor axial ventilation hole (32), the right baffle ventilation hole (31), and the rotor air outlet (33) form the cooling air path of the rotor. The part of the shaft (11) located between the right bearing chamber (6) and the outer end of the right fan bracket is provided with a right air inlet (13). The outer ring of the right air outlet (15) of the right end cover (4) extends inward and forms a labyrinth seal structure with the outer ring of the outer end of the right fan bracket. The right air inlet (13), the right fan, and the right air outlet (15) form the cooling air path of the right bearing chamber.

2. The rotor and bearing cooling structure of a permanent magnet direct drive motor according to claim 1, characterized in that, The rotor air inlet (29) and rotor air outlet (33) are multiple and are evenly distributed around the circumference of the rotating shaft (11). The rotor axial ventilation hole (32), left baffle ventilation hole (30), and right baffle ventilation hole (31) are multiple and are evenly distributed around the rotor core.

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