Axial fan integrated cooling rotor structure and permanent magnet motor

Abstract

The application discloses a kind of shaft fan integrated cooling rotor structures, it is related to permanent magnet motor technical field, including rotating shaft and permanent magnet, rotating shaft includes the thin diameter section and thick diameter section of coaxial fixed connection, and permanent magnet is fixedly covered in thick diameter section outer;Several ventilation channels along parallel to axial through are provided on thick diameter section, and several ventilation channels are distributed along thick diameter section circumferentially;The recess of being communicated each ventilation channel is provided at thick diameter section axial one end, and fan blade assembly is fixedly arranged in recess, fan blade assembly can rotate synchronously with rotating shaft, and can drive airflow through ventilation channel.The shaft fan integrated cooling rotor structure provided in the application can reduce the maximum temperature rise and prolong the service life.The application also provides a kind of permanent magnet motor comprising the above-mentioned shaft fan integrated cooling rotor structure.

Description

Technical Field

[0001] This invention relates to the field of permanent magnet motor technology, and in particular to a shaft-fan integrated cooling rotor structure and a permanent magnet motor. Background Technology

[0002] As a type of high-efficiency and energy-saving motor, the high-speed permanent magnet motor features high efficiency and high power density. This means it can provide greater output power than a traditional motor of the same size, offering advantages in miniaturized or lightweight applications. Furthermore, high-speed permanent magnet motors offer rapid response and high-precision control capabilities. By eliminating the need for gears or other reduction gears, they effectively reduce system noise, leading to their widespread application in electric vehicles, low-altitude aircraft, compressors, and ships.

[0003] However, an improperly designed cooling system for a high-speed permanent magnet motor can lead to a series of serious consequences. For the rotor permanent magnets, high-order time harmonics introduced by the inverter power supply generate significant rotor eddy current losses, resulting in excessively high rotor temperatures. Furthermore, the remanence and coercivity of rare-earth elements such as neodymium iron boron decrease with increasing temperature, reducing the magnetic flux generated by the permanent magnets and causing irreversible demagnetization. This reduces the motor torque, decreasing its load-bearing capacity and output performance. In addition, uneven temperature distribution can cause thermal stress in the motor, altering the clearance between the bearings and the shaft, potentially leading to mechanical deformation or increased motor vibration. Moreover, excessively high temperatures can cause rapid oxidation of the lubricating grease in the bearings, leading to lubricant failure – another issue that cannot be ignored. Summary of the Invention

[0004] The purpose of this invention is to provide an integrated shaft-fan cooling rotor structure and a permanent magnet motor to solve the problems existing in the prior art, reduce the maximum temperature rise, and extend the service life.

[0005] To achieve the above objectives, the present invention provides the following solution: This invention provides an integrated shaft-fan cooling rotor structure, including a shaft and a permanent magnet. The shaft includes a thin-diameter section and a thick-diameter section coaxially and fixedly connected. The permanent magnet is fixedly sleeved on the thick-diameter section. The thick-diameter section is provided with a plurality of ventilation channels that extend parallel to the axial direction and are distributed circumferentially along the thick-diameter section. One axial end of the thick-diameter section is provided with a groove that connects each of the ventilation channels, and a fan blade assembly is fixedly disposed in the groove. The fan blade assembly can rotate synchronously with the shaft and can drive airflow through the ventilation channels.

[0006] Preferably, the fan blade assembly protrudes at least partially from the groove along the axial direction.

[0007] Preferably, the fan blade assembly protrudes axially from the groove by the same dimension as the blade assembly positioned within the groove.

[0008] Preferably, the fan blade assembly includes a plurality of fan blades distributed circumferentially, and the plurality of fan blades correspond one-to-one with the plurality of ventilation ducts in a direction parallel to the axial direction.

[0009] Preferably, each of the fan blades is configured as a straight plate type fan blade.

[0010] Preferably, the plurality of straight-plate fan blades and the plurality of ventilation ducts are evenly distributed in the circumferential direction.

[0011] Preferably, the groove is configured as a cylindrical groove, and the cross-section of each ventilation duct is configured as an annular segment; the inner diameter of the groove is the same as the outer diameter of the narrow diameter segment, and the outer diameter of the groove is the same as the outer diameter of the ventilation duct and smaller than the outer diameter of the thick diameter segment.

[0012] Preferably, it also includes a sheath fixedly fitted onto the body of the permanent magnet.

[0013] Preferably, the axial ends of the sheath, the permanent magnet, and the coarse-diameter section are flush.

[0014] The present invention also provides a permanent magnet motor, including the shaft-fan integrated cooling rotor structure as described above.

[0015] The present invention achieves the following technical effects compared to the prior art: The integrated shaft-fan cooling rotor structure and permanent magnet motor provided by this invention install the fan blade assembly into the groove on the end face of the larger diameter section of the rotating shaft. When the fan blade assembly rotates at high speed with the rotating shaft, it can force air into the axially connected ventilation channel. The airflow through the ventilation channel cools the permanent magnet. Compared with the traditional self-fan cooling structure where air flows directly through the stator winding and rotor surface, this invention allows the airflow to circulate internally for heat exchange, which can significantly improve the convective heat exchange efficiency, effectively reduce the maximum temperature rise of the permanent magnet, extend the service life of the permanent magnet, avoid the risk of irreversible demagnetization caused by local hot spots, and control the operating temperature of the permanent magnet within a safe range. In addition, this structure does not require an additional blower, reducing maintenance needs. The motor forms a fully enclosed self-circulating cooling system, and the axial arrangement of the fan blade assembly and the groove with the rotating shaft forms an integrated shaft-fan cooling rotor, which can optimize the axial space distribution and realize the compact design of high-speed permanent magnet motors. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the shaft-fan integrated cooling rotor structure provided in Embodiment 1 of the present invention; Figure 2 This is a side view of the integrated cooling rotor structure with a shaft fan provided in Embodiment 1 of the present invention; Figure 3 This is a longitudinal sectional view of the integrated cooling rotor structure of the shaft and fan provided in Embodiment 1 of the present invention; Figure 4 This is a cross-sectional schematic diagram of the integrated cooling rotor structure of the shaft and fan provided in Embodiment 1 of the present invention.

[0018] In the diagram: 1-shaft; 11-narrow diameter section; 12-coarse diameter section; 13-ventilation duct; 14-groove; 15-fan blade assembly; 151-fan blade; 2-permanent magnet; 3-sheath. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 are within the scope of protection of the present invention.

[0020] The purpose of this invention is to provide an integrated shaft-fan cooling rotor structure and a permanent magnet motor to solve the problems existing in the prior art, reduce the maximum temperature rise, and extend the service life.

[0021] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] Example 1 This embodiment provides a shaft-fan integrated cooling rotor structure. Please refer to [link / reference]. Figures 1-4 The device includes a rotating shaft 1 and a permanent magnet 2. The rotating shaft 1 includes a thin diameter section 11 and a thick diameter section 12 that are coaxially fixedly connected. The permanent magnet 2 is fixedly sleeved on the thick diameter section 12. The thick diameter section 12 is provided with a number of ventilation channels 13 that are parallel to the axial direction and are distributed around the circumference of the thick diameter section 12. One end of the thick diameter section 12 is provided with a groove 14 that connects each ventilation channel 13. A fan blade assembly 15 is fixedly installed in the groove 14. The fan blade assembly 15 can rotate synchronously with the rotating shaft 1 and can drive the airflow through the ventilation channel 13.

[0023] In this embodiment, by installing the fan blade assembly 15 into the groove 14 on the end face of the coarse diameter section 12 of the rotating shaft 1, the fan blade assembly 15 can force air into the axially penetrating ventilation channel 13 when the rotating shaft 1 rotates at high speed. The airflow through the ventilation channel 13 cools the permanent magnet 2. Compared with the traditional self-ventilated cooling structure where air flows directly through the stator winding and rotor surface, this embodiment allows the airflow to circulate internally for heat exchange, which can significantly improve the convective heat exchange efficiency, effectively reduce the maximum temperature rise of the permanent magnet 2, extend the service life of the permanent magnet 2, avoid the risk of irreversible demagnetization caused by local hot spots, and control the operating temperature of the permanent magnet 2 within a safe range. In addition, this structure does not require an additional blower, reducing maintenance needs. A fully enclosed self-circulating cooling system is formed inside the motor, and the axial arrangement of the fan blade assembly 15 and the groove 14 with the rotating shaft 1 forms an integrated shaft-fan cooling rotor. It takes advantage of the large rotor size of high-power motors in high-speed permanent magnet motors, and while having sufficient axial space, it can optimize the axial space distribution, thus achieving a compact design of high-speed permanent magnet motors.

[0024] Among them, the integrated cooling rotor consisting of fan blade assembly 15, groove 14 and rotating shaft 1 can improve stability through integral molding during the manufacturing process.

[0025] In an optional embodiment, more preferably, the fan blade assembly 15 protrudes at least partially from the groove 14 along the axial direction.

[0026] If the fan blade assembly 15 is completely placed in the groove 14, the high-speed rotation of the fan blade assembly 15 will cause a large vortex in the groove 14, resulting in greater wind friction loss and affecting the cooling effect on the permanent magnet 2. Therefore, the fan blade assembly 15 is set to protrude at least partially from the groove 14 along the axial direction to reduce wind resistance and also have better heat dissipation performance.

[0027] More preferably, the dimension of the fan blade assembly 15 protruding upward along the axial direction from the groove 14 is the same as the dimension placed inside the groove 14; that is, in this embodiment, when the fan blade assembly 15 is installed, half of its axial length needs to be located inside the groove 14, and the other half of its length needs to extend out of the groove 14. This design is beneficial to reduce wind resistance and also has good heat dissipation performance. In practical applications, the matching dimensions of the fan blade assembly 15 and the groove 14 can be specifically determined according to the overall structure dimensions of the rotor.

[0028] In the optional embodiments of this example, more preferably, the fan blade assembly 15 includes a plurality of fan blades 151 distributed circumferentially, and the plurality of fan blades 151 correspond one-to-one with a plurality of ventilation channels 13 in the direction parallel to the axial direction.

[0029] In this embodiment, by making each fan blade 151 correspond to an axial ventilation channel 13, each ventilation channel 13 can achieve ventilation and heat exchange, and the airflow inside each ventilation channel 13 is evenly distributed, thereby promoting a uniform cooling effect on the permanent magnet 2. Specifically, in this embodiment, the number of fan blades 151 and ventilation channels 13 is set to nine.

[0030] In this embodiment, a preferred embodiment is that each fan blade 151 is a straight-plate type fan blade; wherein, the airflow path generated by the straight-plate type fan blade is relatively straight, which is beneficial for directly guiding and propelling the air into the corresponding ventilation duct 13 for heat exchange; specifically, the installation direction of the straight-plate type fan blade is as follows: Figure 1 As shown, the left side of the rotating shaft 1 is the motor end, and the rotation direction should be counterclockwise along the axis. This can force the air in the motor end cavity into the ventilation duct 13. The airflow velocity in the ventilation duct 13 is high, and the directional airflow path ensures uniform and stable cooling effect, avoiding the problem of local overheating of the permanent magnet 2. When the motor rotates at high speed, the ventilation hole on the straight plate fan blade side is the air inlet, while the other side is the air outlet.

[0031] In the optional scheme of this embodiment, more preferably, the plurality of straight-plate fan blades and the plurality of ventilation channels 13 are evenly distributed in the circumferential direction; wherein, the even distribution in the circumferential direction can further promote the uniform heat dissipation of the permanent magnet 2 in the circumferential direction.

[0032] In the optional scheme of this embodiment, more preferably, the groove 14 is set as a cylindrical groove, and the cross-section of each ventilation channel 13 is set as an annular segment; the inner diameter of the groove 14 is the same as the outer diameter of the narrow diameter segment 11, and the outer diameter of the groove 14 is the same as the outer diameter of the ventilation channel 13 and smaller than the outer diameter of the thick diameter segment 12.

[0033] The cylindrical groove facilitates the circumferential arrangement of the fan blade assembly 15; the cross-sectional shape of each axial ventilation duct 13 is a circular segment, and the inner and outer diameters of the ventilation ducts 13 are the same, the outer diameter is the same as the outer diameter of the groove 14, and the central angle they occupy is the same; this is beneficial for fixing the fan blade assembly 15 and maximizing the air volume in a limited space.

[0034] In the optional scheme of this embodiment, more preferably, the integrated cooling rotor structure of the shaft fan provided in this embodiment also includes a protective sleeve 3 fixedly sleeved outside the permanent magnet 2; wherein, the protective sleeve 3 and the permanent magnet 2 are interference fit, and the material of the protective sleeve 3 can be metal or non-metal, which can play a protective role.

[0035] In the optional scheme of this embodiment, it is more preferred that the axial ends of the sheath 3, the permanent magnet 2 and the coarse diameter section 12 are flush; in this way, the overall stability of the rotor structure can be guaranteed.

[0036] Example 2 This embodiment also provides a permanent magnet motor, including the shaft-fan integrated cooling rotor structure as in Embodiment 1; wherein, the other mechanisms of the permanent magnet motor are the same as those of a conventional permanent magnet motor, and will not be described in detail here.

[0037] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. An integrated shaft-fan-cooled rotor structure, characterized by: The device includes a rotating shaft (1) and a permanent magnet (2). The rotating shaft (1) includes a thin diameter section (11) and a thick diameter section (12) that are coaxially fixedly connected. The permanent magnet (2) is fixedly sleeved on the thick diameter section (12). The thick diameter section (12) is provided with a plurality of ventilation channels (13) that run parallel to the axial direction and are distributed circumferentially along the thick diameter section (12). One end of the thick diameter section (12) is provided with a groove (14) that connects each of the ventilation channels (13). A fan blade assembly (15) is fixedly provided in the groove (14). The fan blade assembly (15) can rotate synchronously with the rotating shaft (1) and can drive airflow through the ventilation channel (13).

2. The integrated cooling rotor structure with shaft and fan as described in claim 1, characterized in that: The fan blade assembly (15) protrudes at least partially from the groove (14) axially upward.

3. The integrated cooling rotor structure with shaft and fan as described in claim 2, characterized in that: The fan blade assembly (15) protrudes upward along the axial direction from the groove (14) by the same dimension as that placed within the groove (14).

4. The integrated cooling rotor structure with shaft and fan as described in claim 1, characterized in that: The fan blade assembly (15) includes a plurality of fan blades (151) distributed circumferentially, and the plurality of fan blades (151) correspond one-to-one with the plurality of ventilation ducts (13) in the axial direction.

5. The integrated cooling rotor structure with shaft and fan as described in claim 4, characterized in that: Each of the aforementioned fan blades (151) is configured as a straight plate type fan blade.

6. The integrated cooling rotor structure with shaft and fan as described in claim 5, characterized in that: Several of the straight-plate fan blades and several of the ventilation ducts (13) are evenly distributed in the circumferential direction.

7. The integrated shaft-fan cooling rotor structure according to claim 6, characterized in that: The groove (14) is configured as a cylindrical groove, and the cross-section of each ventilation duct (13) is configured as an annular segment; the inner diameter of the groove (14) is the same as the outer diameter of the narrow diameter segment (11), and the outer diameter of the groove (14) is the same as the outer diameter of the ventilation duct (13) and smaller than the outer diameter of the thick diameter segment (12).

8. The integrated cooling rotor structure with shaft and fan as described in claim 1, characterized in that: It also includes a sheath (3) that is fixedly sleeved outside the permanent magnet (2).

9. The integrated cooling rotor structure with shaft and fan as described in claim 8, characterized in that: The axial ends of the sheath (3), the permanent magnet (2), and the rough diameter section (12) are flush.

10. A permanent magnet motor, characterized in that: Including the integrated cooling rotor structure of the shaft fan as described in any one of claims 1-9.

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