Sheath cooling rotor structure and motor

Abstract

The invention discloses a sheath cooling rotor structure and a motor, and belongs to the technical field of motor rotor cooling, and the sheath cooling rotor structure comprises a shunt ring and rotor segments located at the two sides of the shunt ring; n radial flow guide runners which are uniformly distributed are arranged on the flow dividing ring, and N is an integer greater than 1; inner side ports of the radial flow guide runners are flow guide inlets, and outer side ports of the radial flow guide runners are flow guide outlets; each rotor segment comprises a rotor iron core and a permanent magnet; the outer side of each rotor segment is sleeved with a sheath, and the sheath sequentially comprises an inner sheath and an outer sheath from inside to outside. The inner sheath is provided with N cooling micro-channels extending from the shunt ring to the axial end of the rotor. A port, located in the middle of the rotor, of the cooling micro-channel is connected with a flow guide outlet, and a port located in the axial end of the rotor is a cooling micro-channel outlet; and the inner sheath is not completely broken by the cooling micro-channel in the circumferential direction. According to the invention, the cooling efficiency of the rotor can be effectively improved under the condition that the protection function of the rotor sheath is ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of motor rotor cooling, and more specifically, relates to a jacket cooling rotor structure and a motor. Background Art

[0002] In the fields of aerospace, electric vehicles, more electric / all electric aircraft and industrial robots, in order to meet the weight power density and volume power density indicators, rare earth permanent magnet materials with high magnetic energy product are widely used, and high-density permanent magnet motor systems have become a research hotspot. The thermal management of permanent magnet motor rotors is considered to be the key limiting factor in improving the power density of motors. High power density is usually achieved by increasing the motor speed, which increases the rotor core loss. At the same time, the thermal insulation air gap at high speed makes the rotor have a large thermal resistance to the cooling medium, making it difficult for the motor rotor to dissipate heat. Therefore, the rotor eddy current loss can easily lead to excessive rotor temperature rise. Rotor overheating not only causes irreversible demagnetization of permanent magnets, but also causes failure of the bearing lubrication system. The deformation caused by the thermal stress of the rotor will lead to problems such as sleeve interference changes and even rotor sweeping, affecting the safe and reliable operation of high-speed permanent magnet motors.

[0003] Permanent magnet motors generate large centrifugal forces during high-speed rotation. For surface-mounted permanent magnet motors and high-speed built-in permanent magnet motors, a protective cover must be added to the outside of the motor rotor to protect the rotor core and permanent magnets. In the prior art, a high-strength carbon fiber sheath or a high-strength non-magnetic alloy protective cover is usually added to the outside of the rotor core. In high-temperature environments, the carbon fiber sheath will soften and be damaged due to the poor heat resistance of the resin that serves as a connection. At this time, an alloy sheath is a better choice. However, the alloy protection measure will generate large eddy current losses in the protective sheath, similar to permanent magnets, which will bring greater difficulties to the heat dissipation of the motor.

[0004] The current rotor cooling is usually done through a cooling structure similar to the stator water jacket cooling. The cooling channel structure is designed to reduce the thermal resistance between the cooling medium and the cooling source by passing the cooling medium into the cooling channel, thereby enhancing the rotor heat dissipation capacity. Most of them use air cooling and oil cooling. For high-power density and high-power motors, the rotor usually needs to adopt a cooling method with higher cooling efficiency. The efficient rotor cooling technology of high-power density permanent magnet motor system has become one of the key technologies that need to be solved for high-power permanent magnet motors.

[0005] Traditional rotor cooling structures are mostly designed on the rotor core, and the corresponding cooling channels are relatively large in size. Considering the direction of the motor magnetic circuit and the influence of power transmission, the position design of the cooling channel structure is limited, which limits the rotor cooling efficiency. In the patent document with the authorization announcement number CN217508397U, a motor rotor cooling oil circuit structure is provided. The structure passes oil through the rotating shaft, and introduces cooling oil from the pressure plates on both sides of the rotor at the same time. The weight-reducing holes are used as the rotor cooling oil channels, and the cooling oil flows to the opposite pressure plate at the same time, thereby cooling the end windings. The cooling structure has a certain cooling effect, and the weight-reducing holes are used as oil channels, which makes the impact on electromagnetic performance very small. However, since the weight-reducing holes are far away from the magnetic steel, the direct cooling effect on the eddy current of the magnetic steel is poor. For the case of large rotor losses, the cooling efficiency still needs to be further improved.

[0006] In the patent document with application publication number CN107749678A, a permanent magnet motor rotor sleeve cooling structure device is provided, in which an axial ventilation duct structure is adopted between the rotor sleeve and the core, and the magnetic circuit magnetic resistance is reduced by appropriately extending the rotor core, so as to reduce the magnetic circuit magnetic resistance increased by the ventilation duct as much as possible, and at the same time provide better heat dissipation capacity. This structure basically interrupts the circumferential connection of the sleeve, making the rotor protection function of the sleeve within the thickness of the axial ventilation duct basically invalid. The outer thickness of the sleeve must be increased to ensure the rotor protection capability, which is equivalent to increasing the electromagnetic air gap of the thickness of the axial ventilation duct out of thin air. Even if the magnetic circuit magnetic resistance is partially reduced by extending the rotor core, it still has a high impact on the motor output performance.

[0007] In general, the cooling effect of the existing rotor cooling structure on the rotor needs to be further improved. Summary of the invention

[0008] In view of the defects of the prior art and the need for improvement, the present invention provides a jacket-cooled rotor structure and a motor, the purpose of which is to effectively improve the rotor cooling efficiency while ensuring the protective function of the rotor jacket.

[0009] To achieve the above object, according to one aspect of the present invention, a jacket-cooled rotor structure is provided, comprising: a splitter ring and rotor segments located on both sides of the splitter ring;

[0010] The flow diversion ring is provided with N uniformly distributed radial flow diversion channels; the inner port of the radial flow diversion channel is the flow diversion inlet, and the outer port is the flow diversion outlet;

[0011] The rotor segments include a rotor core and a permanent magnet; a sheath is provided on the outer side of each rotor segment, and the sheath includes an inner sheath and an outer sheath from the inside to the outside;

[0012] The inner jacket is provided with N cooling microchannels extending from the flow splitter ring to the axial end of the rotor; the port of the cooling microchannel located in the middle of the rotor is connected to a flow guide outlet, and the port located at the axial end of the rotor is the outlet of the cooling microchannel; the inner jacket is not completely interrupted by the cooling microchannel in the circumferential direction;

[0013] Wherein, N is an integer greater than 1.

[0014] In some optional embodiments, the cooling microchannels are disposed on the outer surface of the inner jacket.

[0015] In some optional embodiments, the cooling microchannel is a spiral microchannel.

[0016] Furthermore, the cooling micro-channels in the two rotor segments are symmetrically arranged with respect to the flow splitter ring, and the rotation direction of the cooling micro-channels matches the rotation direction of the rotor.

[0017] In some optional embodiments, the cooling microfluidic channel is a square wave, sawtooth or sinusoidal microfluidic channel. The cooling microfluidic channel groove is one or more of a circular arc, an elliptical arc, a rectangle, a trapezoid or a special shape, and a microfluidic channel groove including the above groove shapes with rounded corners.

[0018] In some optional embodiments, the inner sheath includes a flow channel layer and a communication layer arranged sequentially from the inside to the outside;

[0019] The cooling microchannel includes a first microchannel and a second microchannel arranged in the channel layer, and a group of third microchannels arranged in the connecting layer;

[0020] The first microchannel extends from the diverter ring to the axial end of the rotor but does not extend to the axial end of the rotor, and the second microchannel extends from the axial end of the rotor to the diverter ring but does not extend to the diverter ring; the third microchannels of the same group are parallel to each other, and the two ends of each third microchannel are respectively connected to the first microchannel and the second microchannel.

[0021] Furthermore, the jacket cooling rotor structure provided by the present invention further includes: an isolation protection layer provided between the rotor segment and the jacket.

[0022] Furthermore, the third microchannel is arranged along the circumferential direction or has a preset non-zero angle with the circumferential direction.

[0023] According to another aspect of the present invention, there is provided a permanent magnet motor, comprising a rotating shaft, a rotor, a stator and a casing arranged in sequence from inside to outside;

[0024] The rotor is any one of the above-mentioned jacket-cooled rotor structures provided by the present invention;

[0025] The rotating shaft is a hollow structure with one end closed and the other end open, and N cooling medium outlets correspondingly connected to the N radial guide channels in the rotor are arranged in the middle.

[0026] Based on the above-mentioned jacket cooling rotor structure provided by the present invention, when working, after the cooling medium is introduced through the rotating shaft, the cooling medium will be drained through the middle diverter ring, so that the cooling medium flows to the cooling microchannels in the inner jacket of the rotor. Through the centrifugal force of the high-speed rotation of the motor rotor and the pressure of the pump used to pump in the cooling medium, the cooling medium covers the entire jacket surface inside the rotor jacket along the microchannel, and finally flows out at both ends of the rotor axis, further cooling the stator end windings, and then gathering at the bottom of the motor casing, and the entire motor is continuously cooled through the circulation of the cooling medium.

[0027] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects:

[0028] (1) The present invention provides a sheath-cooled rotor structure. The rotor sheath adopts a double-layer sheath design. The rotor sheath is divided into an inner layer and an outer layer. A microchannel cooling structure is only provided on the inner sheath. The design of the microchannel cooling structure ensures that the inner sheath is not completely interrupted in the circumferential direction, thereby minimizing the impact on the protective energy of the sheath. The inner sheath can simultaneously assume the functions of rotor protection and cooling, while the outer rotor fully assumes the rotor protection function. The inner and outer sheaths cooperate with each other, and the protective function of the rotor can be guaranteed without increasing or slightly increasing the thickness of the sheath. Since the cooling is directly performed inside the heat source (i.e., the sheath), the rotor cooling efficiency can be effectively improved. In general, the present invention can effectively improve the cooling efficiency of the rotor while ensuring the protective function of the rotor sheath, and effectively solves the problems of excessive rotor temperature rise caused by large rotor losses and heat dissipation difficulties in high-power and high-power-density permanent magnet synchronous motors, thereby causing irreversible demagnetization of permanent magnets, decreased bearing tolerance, and rotor bore sweeping caused by thermal stress deformation.

[0029] (2) In the preferred embodiment of the present invention, cooling microchannels are designed only on the outer surface of the inner sheath, which can avoid the uneven force on the rotor permanent magnets on the inner side of the sheath caused by the design of the cooling microchannels and the generation of permanent magnet debris, thereby reducing the risk of motor performance degradation and cooling microchannel blockage.

[0030] (3) In a preferred embodiment of the present invention, each cooling microchannel on the outer surface of the inner jacket is a spiral microchannel, so that other jacket parts of the layer where the cooling microchannel is located will form a continuous ring structure in the circumferential direction, thereby minimizing the impact on the jacket protection function while improving the rotor cooling efficiency. In a further preferred embodiment, the cooling microchannels in the two rotor segments are symmetrically arranged about the diverter ring, and the rotation direction of the spiral microchannel matches the rotation direction of the rotor, thereby utilizing the centrifugal force of the rotor at high speed to throw the cooling oil out of the end, reducing the supply demand for an external pump.

[0031] (4) In a preferred embodiment of the present invention, each cooling microchannel on the outer surface of the inner jacket is a square wave type, a sawtooth type or a sinusoidal type microchannel, thereby effectively increasing the contact area between the cooling medium and the heat source in each cooling microchannel, further improving the cooling effect of the rotor.

[0032] (5) In the preferred embodiment of the present invention, the inner jacket is further layered, and the two layers of microchannels are used to form a cooling microchannel. Based on the channel structure, after the cooling medium flows out from the guide outlet, it will fill the first microchannel, then flow into the second microchannel through the third microchannel, and then flow out through the second microchannel. This can reduce the thermal resistance value from the cooling medium to the cooling source, and can effectively reduce the oil pump pressure, further improving the rotor cooling effect. In a further preferred embodiment, an isolation protective layer is also provided between the inner jacket and the rotor segment, which can avoid the uneven force on the rotor permanent magnet inside the jacket due to the design of the cooling microchannel, thereby preventing permanent magnet debris from being generated, and reducing the risk of the cooling microchannel being blocked. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A schematic diagram of the jacket cooling rotor structure provided in Example 1 of the present invention;

[0034] Figure 2 A schematic structural diagram of a splitter ring in a jacket-cooled rotor structure provided in Example 1 of the present invention;

[0035] Figure 3 A schematic diagram of the cooling flow path of the jacket-cooled rotor structure provided in Example 1 of the present invention;

[0036] Figure 4 A schematic diagram of the jacket cooling rotor structure provided in Example 2 of the present invention;

[0037] Figure 5 A schematic diagram of the inner layer sheath microchannel structure of the sheath cooling rotor structure provided in Example 2 of the present invention;

[0038] Figure 6 A schematic diagram of an end portion of a jacket-cooled rotor structure provided in Embodiment 2 of the present invention;

[0039] Figure 7 A schematic diagram of the side structure of the inner jacket of the jacket-cooled rotor structure provided in Example 2 of the present invention;

[0040] Figure 8 A partial enlarged cross-sectional view of a jacket-cooled rotor structure provided in Example 2 of the present invention;

[0041] Fig. 9 A schematic diagram of the inner layer sheath microchannel structure of the sheath cooling rotor structure provided in Example 3 of the present invention;

[0042] Fig.10A schematic diagram of the cooling flow path of the jacket-cooled rotor structure provided in Example 3 of the present invention;

[0043] Fig.11 A schematic diagram of the jacket cooling rotor structure provided in Example 4 of the present invention;

[0044] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0045] 1- diversion ring; 12- diversion inlet, 13- diversion outlet;

[0046] 2- rotor segment; 21- rotor core, 22- permanent magnet;

[0047] 3-sheath; 31-inner sheath, 32-outer sheath, 33-cooling microfluidic channel, 34-cooling microfluidic channel outlet; 312-channel layer, 313-connecting layer, 314-first microfluidic channel, 315-second microfluidic channel, 316-third microfluidic channel;

[0048] 4-Isolation protection layer. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0050] In the present invention, the terms "first", "second", etc. (if any) in the present invention and the accompanying drawings are used to distinguish similar objects but not necessarily to describe a specific order or sequence.

[0051] The eddy current loss generated by the magnetic steel and alloy sheath usually causes the rotor temperature to rise, which in turn causes a series of problems such as permanent magnet demagnetization and rotor bore sweeping. In order to improve the cooling efficiency of the rotor, the present invention provides a sheath-cooled rotor structure and a motor, the overall concept of which is: directly designing a microchannel cooling structure in the rotor sheath so that the cooling medium is in direct contact with the heat source to reduce thermal resistance. At the same time, the rotor sheath is designed to have a layered structure with an inner sheath and an outer sheath, and only the cooling microchannels that will not completely interrupt the circumference of the sheath are designed in the inner sheath, so that the inner sheath simultaneously assumes the functions of rotor protection and cooling, while the outer sheath completely assumes the function of rotor protection, thereby ensuring the protection capability of the rotor sheath while improving the rotor cooling efficiency.

[0052] It is easy to understand that the sheath is completely interrupted in the circumferential direction, which means that it is completely hollowed out in the axial direction at the same angular position of the circumference. This flow channel structure makes the sheath at this angular circumferential position completely rely on the sheath connection layer part of the non-flow channel layer to withstand the centrifugal force of the rotor, and the sheath part of the flow channel layer will not play a role in protecting the rotor at all. As shown above, the microchannel structure sheath of this patent is not completely interrupted in the circumferential direction, which can greatly reduce the disadvantage of the sheath being completely interrupted in the circumferential direction and realize the reuse of rotor protection and cooling functions.

[0053] Based on the above concept, the jacket cooling rotor structure designed by the present invention comprises: a rotor shunt ring and rotor segments located on both sides of the shunt ring; a jacket is provided on the outer side of each rotor segment;

[0054] The flow diversion ring is provided with N uniformly distributed radial flow diversion channels; the inner port of the radial flow diversion channel is the flow diversion inlet, and the outer port is the flow diversion outlet;

[0055] The rotor segment includes: a rotor core and a permanent magnet; the permanent magnet is embedded in a permanent magnet slot punched out of the rotor core;

[0056] The inner jacket is provided with N cooling microchannels extending from the flow splitter ring to the axial end of the rotor; the port of the cooling microchannel located in the middle of the rotor is connected to a flow guide outlet, and the port located at the axial end of the rotor is the outlet of the cooling microchannel; the inner jacket is not completely interrupted by the cooling microchannel in the circumferential direction;

[0057] Wherein, N is an integer greater than 1.

[0058] Based on the above-mentioned jacket cooling structure design, when working, after the cooling medium is introduced through the rotating shaft, the cooling medium will be drained through the middle diverter ring, so that the cooling medium flows to the cooling microchannel in the inner jacket of the rotor. Through the centrifugal force of the high-speed rotation of the motor rotor and the pressure of the pump used to pump in the cooling medium, the cooling medium covers the entire jacket surface inside the rotor jacket along the microchannel, and finally flows out at both ends of the rotor axis, further cooling the stator end winding, and then gathering at the bottom of the motor housing, and continuously cooling the entire rotor through the cooling oil circulation. In practical applications, the cooling medium can be cooling oil or other liquid cooling medium, or it can be a gas cooling medium.

[0059] On the basis of the above structural design, the present invention further designs a variety of cooling microchannel structures, which are described in detail below in conjunction with the embodiments.

[0060] Embodiment 1:

[0061] A jacket cooling rotor structure, such as Figure 1 to Figure 3 As shown, it comprises: a shunt ring 1 and rotor segments 2 located on both sides of the shunt ring; a sheath 3 is provided on the outer side of each rotor segment 2;

[0062] like Figure 2 As shown, the flow diverter ring 1 is provided with N uniformly distributed radial flow diversion channels; the inner port of the radial flow diversion channel is the flow diversion inlet 12, and the outer port is the flow diversion outlet 13;

[0063] like Figure 1 As shown, the rotor segment 2 includes: a rotor core 21 and permanent magnets 22 , and the permanent magnets 22 are embedded in permanent magnet slots punched out of the rotor core 21 .

[0064] The sheath 3 includes an inner sheath 31 and an outer sheath 32 from the inside to the outside;

[0065] The inner jacket 31 is provided with N cooling microchannels extending from the flow splitter ring 1 to the axial end of the rotor; the port of the cooling microchannel located in the middle of the rotor is connected to a guide outlet 13, and the port located at the axial end of the rotor is the outlet of the cooling microchannel; the inner jacket 31 is not completely interrupted by the cooling microchannel in the circumferential direction;

[0066] The inner jacket 31 includes a flow channel layer 312 and a connecting layer 313 arranged in sequence from the inside to the outside; the cooling microchannel includes a first microchannel 314 and a second microchannel 315 arranged in the flow channel layer 312, and a group of third microchannels 316 arranged in the connecting layer 313;

[0067] The first microchannel 314 extends from the flow dividing ring 1 to the axial end of the rotor but does not extend to the axial end of the rotor, and the second microchannel 315 extends from the axial end of the rotor to the flow dividing ring 1 but does not extend to the flow dividing ring 1; the third microchannels 316 of the same group are parallel to each other, and both ends of each third microchannel 316 are connected to the first microchannel 314 and the second microchannel 315 respectively;

[0068] Wherein, N is an integer greater than 1, indicating the number of parallel cooling microchannels; in practical applications, it can be set accordingly according to protection requirements and cooling requirements.

[0069] The cooling medium in the cooling microchannel and cooling flow path designed in this embodiment is as follows Figure 3 As shown, after the cooling medium flows out from the guide outlet, it will fill the first microchannel, then flow into the second microchannel through the third microchannel, and then flow out through the second microchannel. In this parallel microchannel structure, the cooling medium reaches the second channel in parallel at the same time, avoiding the heating process of the cooling medium passing through the channel path, so that the temperature of the cooling medium covering the surface of the rotor sleeve is relatively low, and the cooling medium flows into the second microchannel through the third microchannel and then flows out, which can reduce the thermal resistance value of the cooling medium to the cooling source and further improve the rotor cooling effect.

[0070] Optionally, in this embodiment, the third microchannel is arranged along the circumferential direction. In some other embodiments of the present invention, the third microchannel may also have a certain angle with the circumferential direction, so as to reduce the resistance of the cooling medium flowing in the cooling microchannel.

[0071] As a preferred embodiment, Figure 1 As shown, in this embodiment, the cooling microchannels in the two rotor segments are symmetrically arranged about the diverter ring, which can ensure balanced heat dissipation of the motor rotor about the middle part of the motor.

[0072] In this embodiment, since the cooling microchannel is designed directly in the heat source, the size of the cooling microchannel does not need to be set too large to ensure the cooling effect of the cooling microchannel. Optionally, in order to reduce the impact on the energy conversion and power output of the motor and avoid excessive degradation of the motor performance due to reasons such as increased air gap, in this embodiment, the thickness of the cooling microchannel ranges from 0.1mm to 1.5mm, and is preferably set to less than 1mm when the cooling effect can meet the requirements.

[0073] Embodiment 2:

[0074] A jacket cooling rotor structure, such as Figures 4 to 8 As shown, it comprises: a splitter ring 1 and rotor segments 2 located on both sides of the splitter ring 1;

[0075] like Figure 6 As shown, the flow diverter ring 1 is provided with N uniformly distributed radial flow diversion channels; the inner port of the radial flow diversion channel is the flow diversion inlet 12, and the outer port is the flow diversion outlet 13;

[0076] The rotor segment 2 includes a rotor core 21 and permanent magnets 22 . The permanent magnets 22 are embedded in permanent magnet slots punched out of the rotor core 21 .

[0077] A sheath is provided on the outer side of each rotor segment 2, and the sheath includes an inner sheath 31 and an outer sheath 32 from the inside to the outside;

[0078] The outer surface of the inner jacket 31 is provided with N cooling microchannels 33 extending from the flow divider ring 1 to the axial end of the rotor; the port of the cooling microchannel located in the middle of the rotor is connected to a guide outlet 13, and the port located at the axial end of the rotor is a cooling microchannel outlet 34, such as Figure 4 and Figure 5 As shown; the inner sheath 31 is not completely interrupted by the cooling microchannel in the circumferential direction;

[0079] Wherein, N is an integer greater than 1.

[0080] like Figure 4 and Figure 5 As shown, in this embodiment, the cooling microchannels 33 on the outer surface of the inner jacket 31 are specifically spiral microchannels, so that other jacket parts of the layer where the cooling microchannels are located will form a continuous annular structure in the circumferential direction, thereby minimizing the impact on the jacket protection function while improving the rotor cooling efficiency.

[0081] The number of parallel cooling microchannels N and the number of spiral turns K of each cooling microchannel can be set accordingly according to the protection requirements and cooling requirements in practical applications. Optionally, in this embodiment, the number of parallel cooling microchannels is 6, and the number of spiral turns of each cooling microchannel is 1. In some other embodiments of the present invention, other parameters can be set, and the number of spiral turns of each cooling microchannel does not have to be an integer.

[0082] In this embodiment, the cooling microchannels in the two rotor segments are symmetrically arranged about the diverter ring, thereby ensuring balanced heat dissipation of the motor rotor about the middle part of the motor, and in each rotor segment, the rotation direction of the cooling microchannel is the same as the rotation direction of the rotor, thereby utilizing the centrifugal force of the rotor at high speed to throw the cooling oil out of the end, reducing the supply demand of the motor oil pump.

[0083] In this embodiment, since the cooling microchannel is designed directly in the heat source, the size of the cooling microchannel does not need to be set too large to ensure the cooling effect. Optionally, in order to reduce the impact on the magnetic circuit direction and power output of the protective motor, in this embodiment, the thickness of the cooling microchannel ranges from 0.1mm to 1.5mm, and is preferably set to less than 1mm when the cooling effect can meet the requirements. Figure 7 As shown, Figure 7 In the figure, the enlarged part of the “M” is shown in Figure 8 shown. Figure 8 In the left side, a represents the thickness of the cooling microchannel, and b represents the remaining thickness of the inner jacket after machining the cooling microchannel.

[0084] In this embodiment, the size of the cooling microchannel is relatively small. In view of this, the cooling microchannel is arranged on the outer surface of the inner sheath in this embodiment, which can avoid the uneven force on the rotor permanent magnet on the inner side of the sheath caused by the design of the cooling microchannel and the generation of permanent magnet debris, thereby reducing the risk of clogging of the cooling microchannel.

[0085] Embodiment 3:

[0086] A jacket cooling rotor structure. This embodiment is similar to the above-mentioned embodiment 2, and the outer surface of the inner jacket 31 is provided with N cooling microchannels 33 extending from the diverter ring 1 to the axial end of the rotor; the port of the cooling microchannel located in the middle of the rotor is connected to a guide outlet 13, and the port located at the axial end of the rotor is a cooling microchannel outlet 34; the difference from the above-mentioned embodiment 2 is that, in this embodiment, the cooling microchannel 33 on the outer surface of the inner jacket 31 is a square wave microchannel, such as Fig. 9 shown.

[0087] In this embodiment, the flow path of the cooling medium in the cooling microchannel is as follows: Fig.10As shown, this curved flow channel structure can effectively increase the heat dissipation area and further improve the rotor cooling efficiency while ensuring that the inner sleeve is not completely interrupted in the circumferential direction.

[0088] In this embodiment, the specific implementation of the remaining structures can refer to the description in the above-mentioned embodiment 2 and will not be repeated here.

[0089] Similarly, since the cooling microchannels in this embodiment are only arranged on the outer surface of the inner jacket, it is possible to avoid uneven force on the rotor permanent magnets inside the jacket due to the design of the cooling microchannels, thereby reducing the risk of clogging the cooling microchannels.

[0090] Based on the same design concept, in some other embodiments of the present invention, the cooling microfluidic channel flow path can also be designed as a microfluidic channel flow path in other forms such as a sawtooth type or a sinusoidal type. The cooling microfluidic channel groove shape can be designed as one or more of a circular arc shape, an elliptical arc shape, a rectangle, a trapezoid or a special shape, as well as other forms of microfluidic channel groove shapes including the above groove shapes plus rounded corners.

[0091] Embodiment 4:

[0092] A jacket cooling rotor structure. This embodiment is similar to the above-mentioned embodiment 1, except that, in this embodiment, based on the same considerations as in embodiments 2 and 3, in order to reduce the risk of the cooling microchannel being blocked, in this implementation, an isolation protective layer 4 is further provided between the rotor segment and the jacket 3, so that the cooling microchannel 33 does not directly contact the rotor, such as Fig.11 shown.

[0093] In this embodiment, the specific implementation of the oil separator plate 1, the inner jacket 31, the outer jacket 32, the cooling microchannels in the inner jacket and other structures can refer to the description in the above-mentioned embodiment 1, and the flow path of the cooling medium in the cooling microchannels is also the same as that in embodiment 1.

[0094] Embodiment 5:

[0095] A permanent magnet motor comprises a rotating shaft, a rotor, a stator and a casing which are arranged in sequence from inside to outside;

[0096] The rotor is a jacket-cooled rotor structure provided in any one of the above-mentioned embodiments 1 to 4;

[0097] The rotating shaft is a hollow structure with one end closed and the other end open, and N cooling medium outlets correspondingly connected to the N radial guide channels in the rotor are arranged in the middle.

[0098] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A jacket cooling rotor structure, characterized in that: include: A splitter ring and rotor segments located on both sides of the splitter ring; The diverter ring is provided with N uniformly distributed radial flow guide channels; the inner port of the radial flow guide channel is the flow guide inlet, and the outer port is the flow guide outlet; The rotor segments include a rotor core and a permanent magnet; a sheath is provided on the outside of each rotor segment, and the sheath includes an inner sheath and an outer sheath from the inside to the outside; The inner jacket is provided with N cooling microchannels extending from the flow splitter ring to the axial end of the rotor; the port of the cooling microchannel located in the middle of the rotor is connected to a flow guide outlet, and the port located at the axial end of the rotor is the outlet of the cooling microchannel; the inner jacket is not completely interrupted by the cooling microchannel in the circumferential direction; Wherein, N is an integer greater than 1.

2. The jacket-cooled rotor structure according to claim 1, characterized in that: The cooling microchannel is arranged on the outer surface of the inner jacket.

3. The jacket-cooled rotor structure according to claim 2, characterized in that: The cooling microchannel is a spiral microchannel.

4. The jacket-cooled rotor structure according to claim 3, characterized in that: The cooling micro-channels in the two rotor segments are symmetrically arranged about the diverter ring, and the rotation direction of the cooling micro-channels matches the rotation direction of the rotor.

5. The jacket-cooled rotor structure according to claim 2, characterized in that: The cooling microchannel is a square wave type, a sawtooth type, a sinusoidal type, a circular arc type, an elliptical arc type, or a rectangular microchannel with rounded corners.

6. The jacket-cooled rotor structure according to claim 1, characterized in that: The inner sheath comprises a flow channel layer and a communication layer arranged in sequence from the inside to the outside; The cooling microchannel includes a first microchannel and a second microchannel disposed in the channel layer, and a group of third microchannels disposed in the connecting layer; The first microchannel extends from the diverter ring to the axial end of the rotor but does not extend to the axial end of the rotor, and the second microchannel extends from the axial end of the rotor to the diverter ring but does not extend to the diverter ring; the third microchannels of the same group are parallel to each other, and the two ends of each third microchannel are respectively connected to the first microchannel and the second microchannel.

7. The jacket-cooled rotor structure according to claim 6, characterized in that: Also includes: An isolating protective layer disposed between the rotor segments and the casing.

8. The jacket-cooled rotor structure according to claim 6 or 7, characterized in that: The third microchannel is arranged along the circumferential direction or has a preset non-zero angle with the circumferential direction.

9. A permanent magnet motor, characterized in that: It includes a rotating shaft, a rotor, a stator and a casing which are arranged in sequence from the inside to the outside; The rotor is a jacket-cooled rotor structure as claimed in any one of claims 1 to 8; The rotating shaft is a hollow structure with one end closed and the other end open, and N cooling medium outlets correspondingly connected to the N radial guide channels in the rotor are arranged in the middle thereof.

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