Immersed oil cooling structure for magnetic steel of motor

Abstract

The invention discloses a motor magnetic steel immersed oil cooling structure. The structure comprises a hollow rotating shaft; the rotor sleeves the hollow rotating shaft; the sealing bearing is arranged in the hollow rotating shaft and is close to the opening end of the hollow rotating shaft; an oil inlet nozzle; wherein a step structure matched with the sealed bearing is arranged in the hollow rotating shaft, an oil inlet cavity is formed between the step structure and the closed end of the hollow rotating shaft, a first through hole is formed in the step structure, and the oil inlet nozzle penetrates through an inner ring of the sealed bearing and the first through hole and is in sealed connection with the inner ring of the sealed bearing; an outer ring of the sealing bearing is in sealing connection with the inner wall of the hollow rotating shaft, a cooling oil channel is formed in the rotor, and a second through hole communicating the oil inlet cavity with the cooling oil channel is formed in the hollow rotating shaft. According to the invention, it can be ensured that the whole oil path of the rotor reaches a pressure maintaining state, the cooling and heat dissipation effects of the rotor are improved, immersed cooling of the magnetic steel of the rotor is realized, over-temperature demagnetization of the magnetic steel of the rotor, even damage to the motor and the like are avoided, and the cost is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of motor cooling, and in particular to a motor magnetic steel immersed oil cooling structure. Background Art

[0002] At present, the drive motor (such as permanent magnet synchronous motor) in new energy vehicles has become the "heart" of the entire vehicle. With the continuous improvement of power density, the cooling and heat dissipation of the motor has become the core requirement of motor design. Power density refers to the ratio of the peak power to the volume or weight of the motor. It is one of the key indicators for evaluating motor performance. However, the greater the power density of the motor, the stronger the heat dissipation capacity is required. With the increase of motor speed and voltage and the emergence of neutral point boost conditions, the heat dissipation of the motor rotor has become the main research direction. Neutral point boost refers to a function that uses a motor to achieve high-power charging of a high-voltage car (such as 800V) from a low-voltage charging pile (such as 400V).

[0003] The rotor cooling of existing oil-cooled motors is generally achieved by throwing out the cooling oil in the hollow shaft through the centrifugal force of the rotor, thereby taking away the heat of the rotor. However, the cooling oil is in a non-pressure-maintaining state in the entire oil circuit system of the rotor (the non-pressure-maintaining state means that the oil does not fill the entire oil circuit cavity of the rotor, and generally only occupies about half of the cavity), and cannot reach a pressure-maintaining state (the pressure-maintaining state oil means that the oil fills the entire oil circuit cavity of the rotor). As long as the rotor does not rotate, the cooling of the rotor is uneven, and the cooling oil can only rely on gravity to flow out naturally along the oil-throwing hole at the lower end of the rotor, resulting in poor cooling effect on the upper half of the rotor. Moreover, when the rotor is rotating, the cooling oil always flows along the wall of the rotor oil circuit, and the heat dissipation area is limited, resulting in poor heat dissipation effect. In addition, in certain special working conditions such as neutral point boost working conditions, since the upper half of the rotor cannot be cooled in time, the upper half of the rotor magnet may be overheated and demagnetized (demagnetization refers to the irreversible decrease in magnetic properties of the rotor magnet), and even cause motor damage. Summary of the invention

[0004] The purpose of this application is to propose a motor magnet immersed oil cooling structure to ensure that the entire oil circuit of the rotor reaches a pressure-maintaining state, improve the cooling and heat dissipation effect of the rotor, realize immersion cooling of the rotor magnet, avoid overheating and demagnetization of the rotor magnet, and even motor damage, thereby reducing costs.

[0005] In order to solve at least one of the above technical problems, the technical solution of the present application is as follows:

[0006] An oil-immersed cooling structure for a motor magnet according to an embodiment of the present application includes: a hollow rotating shaft with one end closed and the other end open; a rotor sleeved on the hollow rotating shaft; a sealed bearing disposed within the hollow rotating shaft and near the open end of the hollow rotating shaft; an oil inlet nozzle; wherein, a stepped structure cooperating with the sealed bearing is provided within the hollow rotating shaft, an oil inlet cavity is formed between the stepped structure and the closed end of the hollow rotating shaft, the stepped structure is located between the sealed bearing and the oil inlet cavity, a first through hole communicating with the oil inlet cavity is provided on the stepped structure, the oil inlet nozzle passes through the inner ring of the sealed bearing and the first through hole and is sealingly connected to the inner ring of the sealed bearing, the outer ring of the sealed bearing is sealingly connected to the inner wall of the hollow rotating shaft, a cooling oil passage is provided on the rotor, and a second through hole communicating the oil inlet cavity with the cooling oil passage is provided on the hollow rotating shaft.

[0007] In a possible implementation of the above embodiment, the rotor includes two sets of rotor cores arranged in sequence along the axial direction of the hollow rotating shaft, each set of rotor cores is provided with a cooling oil passage, and the two sets of rotor cores are sealingly connected through an oil baffle.

[0008] In a possible implementation of the above embodiment, the second through hole and the oil baffle are located in the middle of the hollow rotating shaft, each cooling oil passage penetrates along the axial direction of the rotor core, and an oil outlet passage and a mounting through hole cooperating with the hollow rotating shaft are provided on the oil baffle, the oil outlet passage communicates with the mounting through hole and is respectively communicated with the second through hole and the two cooling oil passages.

[0009] In a possible implementation of the above embodiment, the oil outlet passage penetrates the oil baffle along the axial direction of the rotor, and the cooling oil passage is the gap between each magnet slot on the rotor core.

[0010] In a possible implementation of the above embodiment, the second through holes are multiple and evenly distributed along the circumferential direction of the hollow rotating shaft, and the number of the second through holes is the same as the number of magnetic poles of the rotor.

[0011] In a possible implementation of the above embodiment, the oil outlet passages are multiple and evenly distributed along the circumferential direction of the rotor core, and the oil outlet passages correspond to the second through holes one by one.

[0012] In a possible implementation of the above embodiment, the diameter of the first through hole is smaller than the diameter of the oil inlet cavity.

[0013] In a possible implementation of the above embodiment, the stepped structure further includes: a first stepped surface, the end of the outer ring of the sealed bearing is pressed against the first stepped surface; a second stepped surface, corresponding to the inner ring of the sealed bearing, there is a gap between the end of the inner ring of the sealed bearing and the second stepped surface, and the outer diameter of the second stepped surface is larger than the inner diameter of the inner ring of the sealed bearing and smaller than the inner diameter of the outer ring of the sealed bearing.

[0014] In a possible implementation of the above embodiment, the axial ends of the rotor are respectively sealed and connected through balance plates. Oil accumulation grooves communicating with the cooling oil channels and oil outlets communicating with the oil accumulation grooves are respectively arranged on the two balance plates. The oil accumulation grooves are located at one end of the balance plates close to the rotor.

[0015] In a possible implementation of the above embodiment, connection through holes matching the hollow rotating shaft are arranged on each balance plate. The oil accumulation grooves on each balance plate are multiple and evenly distributed along the circumferential direction of the rotor. The number of oil accumulation grooves on each balance plate is the same as the number of magnetic poles of the rotor.

[0016] In a possible implementation of the above embodiment, the oil outlet is located at one end of the oil accumulation groove far from the hollow rotating shaft.

[0017] In a possible implementation of the above embodiment, the oil inlet nozzle is arranged on the end cover of the motor.

[0018] At least one of the above technical solutions of the present application has the following beneficial effects:

[0019] According to the motor magnet immersed oil cooling structure of the present application, the rotor is sleeved on the hollow rotating shaft. A sealing bearing matching the oil inlet nozzle and a stepped structure matching the sealing bearing are arranged at the open end inside the hollow rotating shaft. An oil inlet cavity is formed between the stepped structure and the closed end of the hollow rotating shaft. The stepped structure is located between the sealing bearing and the oil inlet cavity. A first through hole communicating with the oil inlet cavity is arranged on the stepped structure. The oil inlet nozzle passes through the inner ring of the sealing bearing and the first through hole and is hermetically connected to the inner ring of the sealing bearing. The outer ring of the sealing bearing is hermetically connected to the inner wall of the hollow rotating shaft. A cooling oil channel is arranged on the rotor. A second through hole communicating the oil inlet cavity with the cooling oil channel is arranged on the hollow rotating shaft. Thus, the sealing of the open end of the hollow rotating shaft can be realized. Whether the rotor rotates or not, the entire oil circuit of the rotor can be guaranteed to be in a pressure maintaining state, so that the cooling oil is in full contact with the rotor, and the magnets of the rotor are immersed in cooling, ensuring that the cooling and heat dissipation of the rotor are more uniform and comprehensive, improving the cooling and heat dissipation effect of the rotor, realizing the immersed cooling of the magnets of the rotor, avoiding over-temperature demagnetization of the magnets of the rotor and even damage to the motor, etc., and being able to meet the requirements under some special working conditions such as neutral point boosting working conditions, with high safety and reliability. Moreover, the sealing bearing and the stepped structure can also play a role in supporting and restricting the oil inlet nozzle, with a stable and reliable structure, prolonging the service life, reducing the cost, and being convenient for better use in drive motors in new energy vehicles, etc.

[0020] In addition, in the technical solution of the present application, where no special description is made, the present technical solution can be realized by adopting conventional means in the art. Description of the Drawings

[0021] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 A cross-sectional view of a motor magnetic steel immersed oil cooling structure according to an embodiment of the present application;

[0023] Figure 2 for Figure 1 A partial enlarged view of point B in the middle;

[0024] Figure 3 A schematic diagram of a partial structure of a motor magnetic steel immersed oil cooling structure according to an embodiment of the present application;

[0025] Figure 4 This is a schematic structural diagram of a rotor core according to an embodiment of the present application;

[0026] Figure 5 This is a schematic structural diagram of an oil baffle according to an embodiment of the present application;

[0027] Figure 6 This is a schematic diagram of the structure of a balance board according to an embodiment of the present application;

[0028] Figure 7 A schematic diagram of the dissected structure of a motor magnetic steel immersed oil cooling structure according to an embodiment of the present application.

[0029] Description of the reference numerals in the accompanying drawings:

[0030] Hollow shaft 100; step structure 110; first through hole 111; first step surface 112; second step surface 113; oil inlet cavity 120; second through hole 130;

[0031] Rotor 200; cooling oil passage 201; rotor core 210; oil baffle 220; mounting through hole 221; oil outlet passage 222;

[0032] Sealed bearing 300;

[0033] Oil inlet nozzle 400;

[0034] Balance plate 500; oil storage groove 501; oil outlet 502; connecting through hole 503;

[0035] End cap 600. DETAILED DESCRIPTION

[0036] In order to make the objectives, technical solutions and advantages of the present application more clearly understood, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are part of the embodiments of the present application, rather than all of the embodiments, and are only used to explain the present application, not to limit the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the scope of protection of the present application.

[0037] In the description of the present application, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "inner", "outer", "both ends", "both sides", "bottom", "top", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the element referred to must have a specific orientation or be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present application. In addition, the terms "first", "second", "superior", "inferior", "main", "secondary", etc. are only used for descriptive purposes and can be simply used to more clearly distinguish different components, and should not be construed as indicating or implying relative importance.

[0038] In the description of the present application, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0039] It should be noted that in the existing rotor cooling structure of oil-cooled motors, under the influence of various factors, whether the rotor rotates or not, the rotor oil circuit is in a non-pressure-maintaining state, the cooling and heat dissipation effect is poor, there are risks such as overheating and demagnetization of the magnetic steel in the upper half of the rotor, and even damage to the motor, and it cannot meet the requirements of some special working conditions such as the neutral point boosting working condition. Using high-grade magnetic steel can increase the demagnetization temperature point of the magnetic steel, but the cost is high.

[0040] See Figures 1 to 7 As shown, there is schematically shown a motor magnet immersed oil cooling structure provided according to an embodiment of the present application, which is mainly used for the cooling and heat dissipation of the rotor 200 of a motor, such as a permanent magnet synchronous drive motor in a new energy vehicle. The motor magnet immersed oil cooling structure of the present application may include: a hollow rotating shaft 100, a rotor 200, a sealed bearing 300, and an oil inlet nozzle 400.

[0041] One end of the hollow rotating shaft 100 is closed, and the other end of the hollow rotating shaft 100 is open. The rotor 200 is sleeved on the hollow rotating shaft 100, and the rotor 200 and the hollow rotating shaft 100 rotate synchronously. The sealed bearing 300 is arranged inside the hollow rotating shaft 100 and close to the open end of the hollow rotating shaft 100. A step structure 110 is arranged inside the hollow rotating shaft 100 and is matched with the sealed bearing 300. The step structure 110 is also close to the closed end of the hollow rotating shaft 100. An oil inlet cavity 120 is formed between the step structure 110 and the closed end of the hollow rotating shaft 100. The step structure 110 is located between the sealed bearing 300 and the oil inlet cavity 120. A first through hole 111 communicating with the oil inlet cavity 120 is arranged on the step structure 110. The oil inlet nozzle 400 passes through the inner ring of the sealed bearing 300 and the first through hole 111. The oil inlet nozzle 400 is sealingly connected with the inner ring of the sealed bearing 300 (such as interference fit), and the outer ring of the sealed bearing 300 is sealingly connected with the inner wall of the hollow rotating shaft 100 (such as interference fit). A cooling oil passage 201 is arranged on the rotor 200. A second through hole 130 is arranged on the hollow rotating shaft 100. The second through hole 130 communicates the oil inlet cavity 120 with the cooling oil passage 201.

[0042] The motor magnet immersed oil cooling structure of the present application is arranged in the corresponding motor. The corresponding oil supply device supplies the cooling oil into the oil inlet cavity 120 inside the hollow rotating shaft 100 through the oil inlet nozzle 400. Then the cooling oil enters the cooling oil passage 201 of the rotor 200 through the second through hole 130 on the hollow rotating shaft 100. The rotor 200 is cooled and dissipated by the cooling oil. Then the cooling oil flows out from the cooling oil passage 201, and the flowing out cooling oil can flow back to the oil supply device for recycling after being cooled, so as to realize the cooling and heat dissipation of the rotor 200. By arranging the sealed bearing 300 at the open end inside the hollow rotating shaft 100, the sealing connection between the oil inlet nozzle 400 and the hollow rotating shaft 100 is realized. Whether the rotor 200 rotates or not, the cooling oil can fill the entire oil passage cavity of the rotor 200 such as the oil inlet cavity 120 and the cooling oil passage 201, so that the entire oil passage of the rotor 200 reaches a pressure maintaining state, realizing the immersed cooling of the magnet of the rotor 200, cooling and dissipating the heat of the rotor 200 evenly and comprehensively. Moreover, the sealed bearing 300 and the step structure 110 can also play a role in supporting and restricting the oil inlet nozzle 400, and the structure is firm and reliable.

[0043] Thus, in the motor magnet immersed oil cooling structure of the present application, the sealing bearing 300 is used to achieve the sealed connection between the oil inlet nozzle 400 and the hollow rotating shaft 100. Whether the rotor 200 rotates or not, the cooling oil can fill the oil passages of the rotor 200 such as the oil inlet cavity 120 and the cooling oil passage 201, enabling the cooling oil to fully contact the rotor 200, ensuring that the entire oil passage of the rotor 200 is always in a pressure-holding state, performing immersed cooling on the magnet stack of the rotor 200, ensuring uniform and comprehensive cooling and heat dissipation of the rotor 200, improving the cooling and heat dissipation effect of the rotor 200, realizing the immersed cooling of the magnet of the rotor 200, avoiding over-temperature demagnetization of the magnet of the rotor 200 and even damage to the motor, etc. Even under certain special working conditions such as the neutral point boost working condition, the requirements can be met, with high safety and reliability, wide application range, and the sealing bearing 300 and the stepped structure 110 can also support and restrain the oil inlet nozzle 400, with a stable and reliable structure, extended service life, reduced cost, and being convenient for better use in drive motors in new energy vehicles, etc. In addition, a ring-shaped sealing structure matching the inner wall of the rotor 200 can be welded on the outer ring of the sealing bearing 300, with better sealing effect, etc.

[0044] In some embodiments, referring to Figure 1 、 3 ~FIGS. 5 and 7, the rotor 200 includes two groups of rotor cores 210 arranged in sequence along the axial direction of the hollow rotating shaft 100. Each group of rotor cores 210 is provided with a cooling oil passage 201. The two groups of rotor cores 210 are hermetically connected through an oil baffle 220, and the two rotor cores 210 and the oil baffle 220 can be clamped and fixed. Among them, the two groups of rotor cores 210, the oil baffle 220 and the hollow rotating shaft 100 rotate together. Each group of rotor cores 210 is provided with a through hole connected to the hollow rotating shaft 100. The second through hole 130 and the oil baffle 220 can be located in the middle of the hollow rotating shaft 100. Each cooling oil passage 201 runs through along the axial direction of the rotor core 210. The oil baffle 220 is provided with an oil outlet passage 222 and a mounting through hole 221 matching the hollow rotating shaft 100. The oil outlet passage 222 is communicated with the mounting through hole 221 and is respectively communicated with the second through hole 130 and the two cooling oil passages 201. The oil baffle 220 can be generally circular or other suitable shapes. Each group of rotor cores 210 can include one, two or more rotor cores 210 connected in sequence. The cooling oil passage 201 passes through each rotor core 210 of each group of rotor cores 210. The number of rotor cores 210 of the two groups of rotor cores 210 can be the same or different.

[0045] That is to say, the cooling oil enters the oil outlet channel 222 on the oil baffle 220 from the second through hole 130, and then the cooling oil in the oil outlet channel 222 flows into one end of the cooling oil channels 201 of the two groups of rotor cores 210 on both sides of the oil baffle 220 respectively. Finally, the cooling oil flows out from the other ends of the two cooling oil channels 201 respectively. Thus, by dividing the rotor 200 into two groups of rotor cores 210 and sealing and connecting the two groups of rotor cores 210 through the oil baffle 220, not only is the processing, manufacturing, assembly, etc. more convenient, the efficiency is improved, and the cost is reduced, but also the length of each cooling oil channel 201 is reduced, ensuring that the cooling oil better fills the oil outlet channel 222 and the cooling oil channels 201, and further improving the cooling and heat dissipation effect of the rotor 200.

[0046] Further, referring to Figure 1 , 3 As shown in FIGS. 5 and 7, the oil outlet channel 222 axially penetrates the oil baffle 220 along the rotor 200, and the cooling oil channels 201 are the gaps between the magnetic steel grooves on each rotor core 210. Among them, each rotor core 210 is provided with magnetic steel, and the number and arrangement of the magnetic steel are determined according to the specific conditions such as the number and arrangement of the magnetic poles of the rotor 200. The magnetic steel can axially penetrate the rotor core 210. Each rotor core 210 is provided with magnetic steel grooves axially penetrating it and matching with the magnetic steel. The gap left between the magnetic steel and the magnetic steel groove is the magnetic steel groove gap, and the magnetic steel groove gaps of the adjacent two rotor cores 210 in each group of rotor cores 210 respectively correspond and communicate with each other. Thus, using the gaps between the magnetic steel grooves on the rotor core 210 as the cooling oil channels 201 not only does not require separate machining of the oil channels, is more convenient for processing and manufacturing, and has a more stable structure, etc., but also can ensure more uniform and comprehensive cooling and heat dissipation of the rotor core 210, with a better cooling and heat dissipation effect and an extended service life of the rotor 200, etc.

[0047] Further, referring to Figure 1 , 3 As shown in FIGS. 5 and 7, there are a plurality of second through holes 130 evenly distributed along the circumferential direction of the hollow rotating shaft 100. The number of the second through holes 130 is the same as the number of magnetic poles of the rotor 200, and the second through holes 130 correspond to the magnetic poles of the rotor 200 one by one. Correspondingly, there are a plurality of oil outlet channels 222 evenly distributed along the circumferential direction of the rotor core 210, and the oil outlet channels 222 correspond to the second through holes 130 one by one.

[0048] Exemplarily, referring to Figure 4 shown in the figure, each rotor core 210 has six magnetic poles evenly distributed along its circumferential direction. Each magnetic pole includes four symmetrically arranged magnetic steels. Each magnetic steel has a rectangular axial cross-section along the rotor core 210, and there are magnetic steel groove gaps between the two short sides of the rectangle and the magnetic steel grooves respectively. Each magnetic steel, each magnetic steel groove, and each magnetic steel groove gap axially penetrate the rotor core 210; referring toFigure 5 As shown, six oil outlet channels 222 are evenly distributed along the circumferential direction of the oil baffle 220. Each oil outlet channel 222 penetrates the oil baffle 220 along the axial direction of the rotor 200. The oil outlet channels 222 respectively correspond to the magnetic poles of each group of rotor cores 210 one by one, that is, one side of each oil outlet channel 222 corresponds to the four magnetic steels and the corresponding magnetic steel groove gaps of one magnetic pole on one group of rotor cores 210, and the other side corresponds to the four magnetic steels and the corresponding magnetic steel groove gaps of one magnetic pole on the other group of rotor cores 210. Correspondingly, there are six second through holes 130 evenly distributed along the circumferential direction of the hollow rotating shaft 100, and the second through holes 130 are in one-to-one correspondence and communication with the oil outlet channels 222. Thus, the cooling oil can better fill each oil passage, realizing the immersion cooling of the magnetic steels of the rotor 200, ensuring more uniform and comprehensive cooling and heat dissipation of the rotor core 210, having a better cooling and heat dissipation effect, and prolonging the service life of the rotor 200, etc.

[0049] In some embodiments, referring to Figures 1 to 2 Figures 6 and 7, the diameter of the first through hole 111 is smaller than the diameter of the oil inlet cavity 120. Thus, a step surface is also formed at one end of the step structure 110 facing the oil inlet cavity 120, preventing the oil inlet cavity 120 from flowing back along the oil inlet nozzle 400 and the first through hole 111, and better ensuring that the entire oil circuit of the rotor 200 reaches a pressure maintaining state, with higher stability and reliability.

[0050] In some embodiments, referring to Figure 2 Figure 8, the step structure 110 further includes a first step surface 112 and a second step surface 113. Among them, the outer ring end of the sealed bearing 300 is pressed against the first step surface 112, the second step surface 113 corresponds to the inner ring of the sealed bearing 300, there is a gap between the inner ring end of the sealed bearing 300 and the second step surface 113, and the outer diameter of the second step surface 113 is larger than the inner diameter of the inner ring of the sealed bearing 300 and smaller than the inner diameter of the outer ring of the sealed bearing 300.

[0051] That is to say, the outer ring end of the sealed bearing 300 is pressed against the first step surface 112 for sealing. The first step surface 112 and the second step surface 113 can be circular surfaces. The first step surface 112 and the second step surface 113 are arranged at intervals along the axial direction of the hollow rotating shaft 100, so that there is a gap between the inner ring end of the sealed bearing 300 and the second step surface 113, the inner ring end of the sealed bearing 300 does not contact the second step surface 113, and there is also a relatively small gap between the inner ring of the sealed bearing 300 and the first step surface 112. The gap between the oil inlet nozzle 400 and the second through hole 130 is also relatively small, and the outer wall of the oil inlet nozzle 400 does not contact the inner wall of the second through hole 130. Thus, when the outer ring of the sealed bearing 300 rotates synchronously with the hollow rotating shaft 100, there will be no friction between the inner ring end of the sealed bearing 300 and the second step surface 113, and there will be no friction between the outer wall of the oil inlet nozzle 400 and the inner wall of the second through hole 130. Moreover, since each gap is relatively small, the sealing effect of the entire oil circuit of the rotor 200 can be achieved at this position. At the same time, the oil flowing out from the relatively small gap can also play a good lubricating role for the sealed bearing 300, extending the service life of the sealed bearing 300, etc. In addition, the sealed bearing 300 can also be a grease-lubricated bearing, etc.

[0052] In some embodiments, referring to Figure 1 、 6 As shown in FIGS. ~7, the axial two ends of the rotor 200 are respectively sealed and connected through balance plates 500. Oil accumulation grooves 501 communicated with the cooling oil passage 201 and oil outlet ports 502 communicated with the oil accumulation grooves 501 are respectively arranged on the two balance plates 500. The oil accumulation grooves 501 are located at one end of the balance plates 500 close to the rotor 200. Among them, the two balance plates 500 can be press-fitted at the axial two ends of the rotor 200. For example, structures such as clamping plates can be used to press-fit and fix the balance plates 500 and the rotor 200. The cooling oil in the cooling oil passage 201 first flows into the corresponding oil accumulation grooves 501, and then the cooling oil in the oil accumulation grooves 501 flows out through the oil outlet ports 502. Thus, the structure is more stable, the operation is more convenient, the oil accumulation grooves 501 can also buffer the cooling oil, better cool the ends of the rotor 200, etc., the cooling effect is better, and the service life of the rotor 200 is extended, etc.

[0053] Furthermore, referring to Figure 1 、 6As shown in FIGS. 0 to 7, each balance plate 500 is provided with a connection through-hole 503 that mates with the hollow rotating shaft 100. The oil accumulation grooves 501 on each balance plate 500 are multiple and evenly distributed along the circumferential direction of the rotor 200. The number of oil accumulation grooves 501 on each balance plate 500 is the same as the number of magnetic poles of the rotor 200. Among them, the balance plate 500 can be roughly circular or other suitable shapes. The oil outlet 502 can be located at one end of the oil accumulation groove 501 away from the hollow rotating shaft 100. A sealing ring or the like can also be provided between the balance plate 500 and the rotor 200 for sealing. For example, if the rotor 200 has six magnetic poles, the six oil accumulation grooves 501 on each balance plate 500 are evenly distributed along the circumferential direction of the rotor 200. The oil accumulation grooves 501 correspond one-to-one with the magnetic poles of the rotor 200. The oil accumulation grooves 501 can be fan-shaped coaxial with the rotor 200. One end of the oil accumulation groove 501 is close to the outer side wall of the balance plate 500 and the other end is close to the inner wall of the connection through-hole 503. Thus, it is ensured that the cooling oil fills each oil accumulation groove 501, the cooling and heat dissipation effect is better, and the safety and reliability are higher, etc.

[0054] In some embodiments, referring to Figure 1 , 7 shown, the oil inlet nozzle 400 is provided on the end cover 600 of the motor. An oil passage communicating with the oil inlet nozzle 400 can be provided on the end cover 600. Among them, the oil inlet nozzle 400 can be cylindrical or other suitable non-cylindrical shapes. The oil inlet nozzle 400 and the end cover 600 can adopt an integrally formed structure. Thus, the operation is more convenient, and the structure is more stable and reliable, etc. In addition, the oil inlet nozzle 400 and the end cover 600 can also adopt a split structure.

[0055] In some embodiments, referring to Figure 1 , 7 shown, the end of the hollow rotating shaft 100 away from the oil inlet nozzle 400 is the output end. A connection hole for connecting with other mechanisms can be provided at the output end of the hollow rotating shaft 100, and the hollow rotating shaft 100 drives other mechanisms to rotate. Corresponding rotating bearings and limiting steps or shoulders that cooperate with the rotating bearings can also be provided on the outer sides of both ends of the hollow rotating shaft 100. Thus, the operation is more convenient, and the structure is more stable, etc.

[0056] In summary, the motor magnet immersed oil cooling structure of the present application is arranged in the corresponding motor. The corresponding oil supply device supplies cooling oil into the oil inlet cavity 120 inside the hollow rotating shaft 100 through the oil inlet nozzle 400. Then, the cooling oil enters each oil outlet channel 222 on the oil baffle 220 through each second through hole 130 in the middle of the hollow rotating shaft 100. The cooling oil in each oil outlet channel 222 then enters each magnet slot gap on the two groups of rotor cores 210 respectively. Then, the cooling oil in each magnet slot gap on the rotor core 210 flows out to the oil accumulation groove 501 on its corresponding balance plate 500 respectively. Then, the cooling oil in each oil accumulation groove 501 flows out through the oil outlet 502, and the flowing out cooling oil can flow back to the oil supply device for recycling after being cooled, so as to realize the cooling and heat dissipation of the rotor 200, ensure that the entire oil circuit of the rotor reaches the pressure maintaining state, realize the immersed cooling of the magnet of the rotor 200, with good cooling and heat dissipation effect. Moreover, the sealed bearing 300 and the stepped structure 110 can also play a role in supporting and restricting the oil inlet nozzle 400. There is no friction between the inner ring end of the sealed bearing 300 and the second stepped surface 113. The structure is stable and reliable, the service life is extended, and the cost is reduced, etc.

[0057] Based on the above embodiments of the present application, without explicit negation or conflict, the technical features of one embodiment can be beneficially combined with one or more other embodiments.

[0058] The above are only some embodiments of the present application, which are only used to illustrate the technical solutions of the present application and are not intended to limit them. It should be understood that for those of ordinary skill in the art, without departing from the creative concept of the present application, improvements or substitutions can be made according to the above description, and all such improvements and substitutions should belong to the protection scope of the present application. In this case, all details can be replaced by equivalent elements, and the materials, shapes and sizes can also be arbitrary.

Claims

1. An immersed oil cooling structure for motor permanent magnets, characterized in that, Comprising: A hollow rotating shaft, one end of which is closed and the other end is open; A rotor sleeved on the hollow rotating shaft; A sealed bearing disposed within the hollow rotating shaft and near the open end of the hollow rotating shaft; An oil inlet nozzle; Wherein, a stepped structure is provided within the hollow rotating shaft and is matched with the sealed bearing. An oil inlet cavity is formed between the stepped structure and the closed end of the hollow rotating shaft. The stepped structure is located between the sealed bearing and the oil inlet cavity. A first through hole communicating with the oil inlet cavity is provided on the stepped structure. The oil inlet nozzle passes through the inner ring of the sealed bearing and the first through hole and is hermetically connected to the inner ring of the sealed bearing. The outer ring of the sealed bearing is hermetically connected to the inner wall of the hollow rotating shaft. A cooling oil passage is provided on the rotor. A second through hole communicating the oil inlet cavity with the cooling oil passage is provided on the hollow rotating shaft.

2. The motor magnet immersion oil cooling structure according to claim 1, characterized in that The rotor includes two groups of rotor cores arranged in sequence along the axial direction of the hollow rotating shaft. The cooling oil passage is provided on each group of rotor cores. The two groups of rotor cores are hermetically connected by an oil baffle.

3. The motor magnet immersion oil cooling structure according to claim 2, wherein, The second through hole and the oil baffle are located in the middle of the hollow rotating shaft. Each cooling oil passage penetrates along the axial direction of the rotor core. An oil outlet passage and a mounting through hole matched with the hollow rotating shaft are provided on the oil baffle. The oil outlet passage communicates with the mounting through hole and is respectively communicated with the second through hole and the two cooling oil passages.

4. The motor magnet immersion oil cooling structure according to claim 3, wherein The oil outlet passage penetrates the oil baffle along the axial direction of the rotor. The cooling oil passage is the gap between each magnetic steel groove on the rotor core.

5. The motor magnet immersion oil cooling structure according to claim 4, characterized in that, The second through holes are multiple and evenly distributed along the circumferential direction of the hollow rotating shaft. The number of the second through holes is the same as the number of magnetic poles of the rotor; The oil outlet passages are multiple and evenly distributed along the circumferential direction of the rotor core. The oil outlet passages correspond to the second through holes one by one.

6. The motor magnet immersion oil cooling structure according to claim 1, wherein The diameter of the first through hole is smaller than the diameter of the oil inlet cavity; The stepped structure further includes: A first stepped surface, against which the end of the outer ring of the sealed bearing is pressed; A second stepped surface corresponding to the inner ring of the sealed bearing. A gap is left between the end of the inner ring of the sealed bearing and the second stepped surface. The outer diameter of the second stepped surface is larger than the outer diameter of the inner ring of the sealed bearing and smaller than the inner diameter of the outer ring of the sealed bearing.

7. The motor magnet immersed oil cooling structure according to claim 1, characterized in that, The two axial ends of the rotor are respectively hermetically connected by balance plates. Oil accumulation grooves communicating with the cooling oil passage and oil outlets communicating with the oil accumulation grooves are respectively provided on the two balance plates. The oil accumulation grooves are located at one end of the balance plate close to the rotor.

8. The motor magnet immersion oil cooling structure according to claim 7, characterized in that, A connection through hole matched with the hollow rotating shaft is provided on each balance plate. The oil accumulation grooves on each balance plate are multiple and evenly distributed along the circumferential direction of the rotor. The number of the oil accumulation grooves on each balance plate is the same as the number of magnetic poles of the rotor.

9. The motor magnet immersed oil cooling structure according to claim 8, wherein The oil outlet is located at one end of the oil accumulation groove far from the hollow rotating shaft.

10. The motor magnet immersion oil cooling structure according to any one of claims 1 to 9, characterized in that, The oil inlet nozzle is provided on the end cover of the motor.

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