Oil circuit structure of oil-cooled motor rotor

Abstract

The application discloses an oil circuit structure of an oil-cooled motor rotor, which comprises a shell, a bushing, a rotor core, a first balance plate, a second balance plate, a stator assembly and a rotor shaft. The rotor core, the bushing, the first balance plate and the second balance plate are all sleeved on the rotor shaft, the stator assembly is sleeved on the outer side of the rotor core, the end, away from the rotor shaft, of the bushing is abutted against the shell, the bushing is internally provided with an annular oil distribution groove and a radial oil hole, a plurality of bent oil channels are arranged on the rotor shaft and are in communication with the annular oil distribution groove and the radial oil hole, a plurality of axial oil channels are arranged in the rotor core and are in communication with axial oil outlet holes, and the first balance plate is further provided with an inclined oil outlet hole in communication with the axial oil channels. The oil circuit structure makes the cooling oil free from the dependence on centrifugal force, realizes efficient cooling of the rotor core under all working conditions, is convenient to produce and process, and solves the difficulty of the limitation of the arrangement of the oil inlet on the shaft end in some structures by adopting the radial oil inlet mode of the non-end part.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and in particular to an oil circuit structure for an oil-cooled motor rotor. Background Art

[0002] The integrated electric powertrain is the core system of new energy vehicles. The requirements for its integration and power density are increasing day by day, making oil-cooled motors the mainstream route. Its direct cooling heat source feature can greatly improve cooling efficiency. The motor rotor is the core moving component. If the magnets arranged inside it overheat, their magnetism will be weakened and there is a risk of demagnetization, resulting in limited or permanent degradation of system performance. Therefore, efficient cooling of the rotor has become a top priority.

[0003] At present, the rotor cooling methods of oil-cooled motors are mostly rotor oil throwing and end face spraying. Rotor oil throwing is to pass cooling oil into the shaft and rely on the centrifugal force of the rotor to throw the oil to the oil channel provided on the rotor for cooling. End face spraying is to spray the cooling oil to the two end faces of the rotor for heat exchange. For example, as shown in Chinese patent documents CN112421833B and CN113206563A, the existing technology has the following deficiencies: (1) Since oil throwing relies on the centrifugal force generated by the rotation of the rotor, under low speed and high torque conditions, the centrifugal force is insufficient. At this time, it is not easy for the oil to enter the rotor core radially. The insufficient oil supply makes it impossible to effectively dissipate heat and cool the inside of the rotor core, which will directly limit the sustainable operation time of the rotor core. For example, when the motor is used as a medium to boost the voltage to charge the battery, the rotor core is in a stationary state and is affected by the stator to generate heat. At this time, there is no centrifugal force to allow the oil to enter the rotor core, resulting in a poor cooling effect inside the rotor core. The cooling capacity of the rotor core will directly limit the charging power. (2) Since the cooling oil needs to be passed into the shaft, an oil supply circuit needs to be arranged at one end of the shaft. However, in some architectures, such as the same-axle electric drive, the wheel half-axle will be arranged inside the motor shaft. Not only the support structure of the motor shaft but also the support structure of the wheel half-axle must be arranged on the motor housing. The gap between the two shafts is small, so it is difficult to supply oil from the end of the motor shaft. Summary of the Invention

[0004] In view of the above problems existing in the prior art, an oil circuit structure for an oil-cooled motor rotor is provided.

[0005] The specific technical solutions are as follows:

[0006] An oil circuit structure for an oil-cooled motor rotor mainly includes:

[0007] A stationary component, a rotor shaft, a rotor core sleeved on the rotor shaft, a first balancing plate, a second balancing plate and an expansion ring-type sealing ring;

[0008] One end of the static component is sleeved on the expansion ring, and the other end of the static component is sleeved on the rotor shaft. The first balance plate and the second balance plate are respectively arranged on both sides of the rotor core, and the static component is arranged on the outside of the first balance plate and the second balance plate.

[0009] Among them, a static oil circuit is provided at one end of the static component, a rotating oil circuit is provided at the rotor shaft and the first balance plate, and a free cooling oil circuit is provided at the first balance plate, the rotor core and the second balance plate. One end of the static oil circuit passes through the static component, and the other end of the static oil circuit is connected to the rotating oil circuit, and the rotating oil circuit is connected to the free cooling oil circuit. The free cooling oil circuit passes through the second balance plate and the first balance plate.

[0010] The above-mentioned oil circuit structure of the oil-cooled motor rotor also has the following characteristics:

[0011] The rotor shaft is provided with a plurality of curved oil passages, the curved oil passages including a first radial oil passage, an axial oil passage, and a second radial oil passage. The first radial oil passage is connected to the stationary oil passage, the first radial oil passage is connected to the axial oil passage, the axial oil passage is connected to the second radial oil passage, the second radial oil passage is connected to a radial groove provided in the first balancing plate, the radial groove is connected to the free cooling oil passage, and the curved oil passage and the radial groove form the rotating oil passage.

[0012] Two expansion ring-type sealing rings are provided, and the two expansion ring-type sealing rings are respectively arranged on both sides of the first radial oil passage.

[0013] The above-mentioned oil circuit structure of the oil-cooled motor rotor also has the following characteristics: two annular grooves are provided on the rotor shaft, an annular boss is provided between the two annular grooves, and the first radial oil circuit is provided on the annular boss.

[0014] The above-mentioned oil circuit structure of the oil-cooled motor rotor also has the following characteristics: the expansion ring-type sealing ring is axially broken to form two free ends, and the two free ends can be movably overlapped.

[0015] The above-mentioned oil circuit structure of an oil-cooled motor rotor also has the following characteristics: the stationary component includes a shell and a bushing, the bushing is sleeved on the expansion ring type sealing ring, the bushing is interference fitted in the shell and forms a whole with the shell, a part of the stationary oil circuit is located in one end of the shell, the other part of the stationary oil circuit is located in the bushing, and the oil inlet is located on the shell.

[0016] The above-mentioned oil circuit structure of the oil-cooled motor rotor also has the following characteristics: an oil inlet is provided in the shell, and an annular oil distribution groove and radial oil holes are provided in the bushing. The oil inlet is connected to the radial oil holes, and the first radial oil circuit is connected to the annular oil distribution groove. The oil inlet, the radial oil holes and the annular oil distribution groove form the static oil circuit.

[0017] The above-mentioned oil circuit structure of the oil-cooled motor rotor also has such a feature that the free cooling oil circuit includes an axial oil hole and an inclined oil outlet hole provided in the first balance plate, one end of the axial oil hole is connected to the radial groove, and one end of the axial oil hole is connected to the inclined oil outlet hole, and the inclined oil outlet hole passes through the first balance plate.

[0018] The above-mentioned oil circuit structure of the oil-cooled motor rotor also has the following characteristics: an axial oil channel is provided in the rotor core, the axial oil channel is connected to the axial oil hole, the axial oil channel is connected to the axial oil outlet hole provided in the second balance plate, and the axial oil hole, the axial oil channel, the axial oil outlet hole and the inclined oil outlet hole form the free cooling oil circuit.

[0019] The above-mentioned oil circuit structure of the oil-cooled motor rotor also has the following characteristics: a shaft shoulder is provided on the rotor shaft, the shaft shoulder is located near the static oil circuit, and the side of the shaft shoulder away from the static oil circuit is sequentially provided with the first balance plate, the rotor core and the second balance plate, and the rotor shaft is also sleeved with a locking piece, and the locking piece and the shaft shoulder together realize the clamping and fixation of the second balance plate, the rotor core and the first balance plate.

[0020] The above-mentioned oil circuit structure of the oil-cooled motor rotor also has the following characteristics: a bearing is arranged between the rotor shaft and the housing, one end of the axial oil circuit close to the first radial oil circuit is opposite to one of the bearings, and a ball blocking ball is arranged in the axial oil circuit.

[0021] The positive effects of the above technical solution are:

[0022] The present invention provides an oil circuit structure for an oil-cooled motor rotor. Cooling oil with oil pressure enters the static oil circuit from the oil inlet under the action of pressure, then enters the rotating oil circuit, and finally enters the free cooling oil circuit in the rotor core. The free cooling oil circuit relies on centrifugal force or accumulation to flow out of the rotor core, and can efficiently cool the inside of the rotor core. Compared with the existing technology, on the one hand, the static oil circuit is arranged on the static component (such as the housing), and the oil circuit is arranged on the shaft wall of the rotor shaft. The radial dynamic sealing technology is used to achieve radial oil inlet. There is no need to set an oil inlet opening at the end opening of the rotor shaft, nor is there any need to use the internal cavity of the rotor shaft as a cooling oil channel, which is convenient for production and processing. On the other hand, the oil pressure can be directly used to make the oil enter the entire cooling channel. It can enter the rotor core and cool the inside of the rotor core without the help of centrifugal force, thereby achieving efficient cooling of the rotor core under all working conditions. Moreover, the oil reaching the inside of the rotor core is pressure-free oil, the oil flows slowly, the cooling effect is better, and the efficiency is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A partial structural diagram of the oil circuit structure of the oil-cooled motor rotor provided by the present invention;

[0024] Figure 2 for Figure 1 Schematic diagram of the partial structure of the oil circuit structure of the oil-cooled motor rotor;

[0025] Figure 3 A schematic structural diagram of the bushing provided by the present invention;

[0026] Figure 4 A schematic structural diagram of the sealing ring provided by the present invention;

[0027] Figure 5 A schematic structural diagram of the rotor shaft provided by the present invention;

[0028] Figure 6 A schematic structural diagram of the first balancing board provided by the present invention;

[0029] Figure 7 This is a structural schematic diagram of the oil inlet circuit with oil pressure provided by the present invention.

[0030] In the accompanying drawings: 1. Housing; 11. Stationary oil circuit; 2. Rotor core; 21. Axial oil channel; 3. Bushing; 31. Radial oil hole; 32. Annular oil distribution groove; 4. First balance plate; 41. Radial groove; 412. Radial oil channel; 42. Inclined oil outlet hole; 43. Axial oil hole; 5. Second balance plate; 51. Axial oil outlet hole; 7. Rotor shaft; 71. Bent oil channel; 711. First radial oil channel; 712. Second radial oil channel; 713. Axial oil channel; 72. Annular groove; 73. Annular boss; 74. Shoulder; 8. Expanding ring type sealing ring; 10. Ball plug; 20. Locking piece; 30. Wheel axle. DETAILED DESCRIPTION

[0031] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0032] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" and the like indicate positions or locations based on those shown in the accompanying drawings. These terms are intended solely to facilitate and simplify the description of the present invention and are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not intended to indicate or imply relative importance.

[0033] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific contexts.

[0034] See Figures 1 to 7, shows a preferred embodiment, showing an oil circuit structure of an oil-cooled motor rotor, including: a stationary component, a rotor shaft 7 and a rotor core 2 sleeved on the rotor shaft 7, a first balance plate 4, a second balance plate 5 and an expansion ring-type sealing ring 8; the oil circuit structure in this embodiment frees the cooling oil from dependence on centrifugal force, realizes efficient cooling of the rotor core under all working conditions, is easy to produce and process, and the non-end radial oil inlet method also solves the difficulty of limited oil inlet arrangement at the shaft end in some architectures.

[0035] One end of the static component is sleeved on the expansion ring type sealing ring 8 (dynamic sealing ring), and the other end of the static component is sleeved on the rotor shaft 7. The first balance plate 4 and the second balance plate 5 are respectively arranged on both sides of the rotor core 2, and the static component is arranged on the outside of the first balance plate 4 and the second balance plate 5.

[0036] In this embodiment, the rotor shaft 7 is a hollow sleeve structure, in which a shaft structure can be installed. Optionally, the shaft structure can be a wheel axle 30, which is inserted into the rotor shaft 7.

[0037] Specifically, the stationary component includes a housing 1 and a bushing 3. The bushing 3 is sleeved on the expansion ring 8. The bushing 3 is interference-fitted within the housing 1 and forms an integral unit with the housing 1. A portion of the stationary oil circuit 11 is located within one end of the housing 1, while the other portion is located within the bushing 3. The oil inlet of the stationary oil circuit 11 is located on the housing 1. The housing 1 is provided with a bushing hole, and the bushing 3 is accommodated in the bushing hole. The bushing 3 is spaced a certain distance from the first balance plate 4 in the axial direction. For details, see Figure 1 shown.

[0038] The housing 1 is disposed on the outside of the rotor shaft 7 , the rotor core 2 , the first balancing plate 4 , the second balancing plate 5 and the expansion ring type sealing ring 8 .

[0039] A static oil circuit is provided at one end of the static component, a rotating oil circuit is provided at the rotor shaft 7 and the first balancing plate 4, a free cooling oil circuit is provided at the first balancing plate 4, the rotor core 2 and the second balancing plate 5, one end of the static oil circuit 11 passes through the static component and forms an oil inlet on the housing 1 in the static component, wherein the oil inlet is provided at one end of the static oil circuit 11, and the other end of the static oil circuit 11 is connected to the rotating oil circuit, and the rotating oil circuit is connected to the free cooling oil circuit, and the free cooling oil circuit passes through the second balancing plate 5 and the first balancing plate 4, wherein both the first balancing plate 4 and the second balancing plate 5 are provided with an oil outlet hole, which can be part of the free cooling oil circuit or be provided separately. When provided separately, the oil outlet hole is connected to the free cooling oil circuit.

[0040] Specifically, the static oil path 11 further comprises an annular oil distribution groove 32 and a radial oil hole 31 arranged in the bushing 3 and in communication, the radial oil hole 31 being part of the static oil path with the annular oil distribution groove 32, and specifically referring to Figure 2 as shown.

[0041] Optionally, in the embodiment, the rotor shaft 7 is provided with a plurality of bent oil channels 71, the bent oil channels 71 comprising a first radial oil path 711, an axial oil path 713 and a second radial oil path 712, the first radial oil path 711 being in communication with the static oil path, the first radial oil path 711 being in communication with the axial oil path 713, the axial oil path 713 being in communication with the second radial oil path 712, the second radial oil path 712 being in communication with the radial grooves 41 arranged in the first balance plate 4, the radial grooves 41 being in communication with the free cooling oil path, the bent oil channels 71 and the radial grooves 41 forming the rotating oil path; wherein the first radial oil path 711, the axial oil path 713 and the second radial oil path 712 form a “]” shaped pipeline or an “F” shaped pipeline. The first radial oil path 711 is in communication with the annular oil distribution groove 32. Optionally, the number of the bent oil channels 71 and the radial grooves 41 is the same, and they are arranged one by one. For example, in the embodiment, the bent oil channels 71 and the radial grooves 41 are both provided with six, forming six rotating oil paths. The number of the bent oil channels 71 and the radial grooves 41 can also be other, which is not described here.

[0042] Optionally, in the embodiment, the bulging ring type sealing ring 8 is provided with two, and the two bulging ring type sealing rings 8 are arranged on both sides of the first radial oil path 711.

[0043] Optionally, in the embodiment, the rotor shaft 7 is provided with two annular grooves 72, and the two annular grooves 72 have an annular boss 73 therebetween, and the first radial oil path 711 is arranged on the annular boss 73. Optionally, the bulging ring type sealing ring 8 is a rotating sealing ring, and specifically referring to Figure 4 as shown. The bulging ring type sealing ring 8 can be a buckle type sealing ring, or other shapes, such as an open type or an L type.

[0044] Optionally, to achieve sealed pressure storage between the fixed bushing 3 and the rotating rotor shaft 7, an expanding ring-type rotary seal ring 8 is employed. This seal ring offers the advantages of low leakage, low friction, and long life. It requires the sealing surfaces of its mating parts to possess high machining precision and surface quality. Therefore, the bushing 3 is constructed of steel and fixed to the housing 1. The bushing 3 and the rotor shaft 7 serve as mating parts for the expanding ring-type seal ring 8. Two annular grooves 72 are defined on the rotor shaft 7 for mounting the expanding ring-type seal ring 8. The outer surface of the expanding ring-type seal ring 8 is in dynamic contact with the inner surface of the bushing 3. When pressurized oil is present, the expanding ring-type seal ring 8, relying on centrifugal force and oil pressure, forms a rotating seal with the bushing 3 and rotor shaft 7, achieving throttling and pressure storage. Through this mechanical dynamic seal, cooling oil within the annular oil distribution groove 32 within the bushing 3 is introduced into a plurality of first radial oil passages 711 uniformly distributed circumferentially on the rotor shaft 7. The two ends of the expansion ring type sealing ring 8 are movably overlapped in the circumferential direction. Specifically, the expansion ring type sealing ring 8 is an open annular part. The two ends are overlapped together to have an overlapping area, but are not fixed, so that the expansion ring type sealing ring 8 can expand its diameter under the action of centrifugal force and oil pressure, and achieve throttling to the greatest extent to form a pressure storage sealing effect. The expansion ring type sealing ring 8 can be a circular ring made of alloy or polymer composite material. The oil circuit structure of the oil-cooled motor rotor provided by the present invention introduces a mechanical rotating dynamic sealing structure, and with the help of the oil channel provided by the rotor shaft 7, the first balance plate 4 and the second balance plate 5, the cooling oil is directly sprayed into the interior of the rotor core 2, and after heat exchange with the rotor core 2, it is thrown out to the internal space at the other end of the housing 1. This method gets rid of the traditional method's reliance on centrifugal force and realizes efficient cooling of the rotor core under all working conditions.

[0045] Optionally, the first balancing plate 4 and the second balancing plate 5 are both disc-shaped structures, and the first balancing plate 4 and the second balancing plate 5 are sleeved on the rotor shaft 7 .

[0046] As previously mentioned, the first balancing plate 4 is provided with a radial slot 41, an axial oil hole 43, and an inclined oil outlet hole 42. The axial oil hole 43 and the inclined oil outlet hole 42 form part of a free cooling oil circuit. One end of the axial oil hole 43 communicates with the radial slot 41, while one end of the axial oil hole 43 communicates with the inclined oil outlet hole 42, which penetrates the first balancing plate 4. Cooling oil in the free cooling oil circuit is ejected from the inclined oil outlet hole 42 and flows to the inner surface of the stator end winding for cooling.

[0047] Cooling oil is introduced into the annular oil distribution groove 32 from the oil inlet of the stationary oil circuit. A plurality of subsequent curved oil passages 71, axial oil passages 21, radial grooves 41, and inclined oil outlet holes 42 are provided. The curved oil passages 71 communicate with the annular oil distribution groove 32 to form multiple branching flow channels. Multiple radial grooves 41 on the first balance plate 4, in contact with the end surface of the rotor core 2, form multiple closed radial oil passages 412. Each branching flow channel includes a curved oil passage 71, a radial oil passage 412, an axial oil passage 21, an axial oil outlet hole 51, and an inclined oil outlet hole 42.

[0048] Preferably, the diameter of the axial oil outlet hole 51 is much larger than the diameter of the inclined oil outlet hole 42. This arrangement ensures that most of the cooling oil will undergo heat exchange through the axial oil passage 21 and be ejected through the axial oil outlet hole 51, effectively cooling the interior of the rotor core 2. When the rotor core 2 rotates, some cooling oil is ejected from the axial oil outlet hole 51 to cool the inner surface of the stator end winding at the other end of the housing 1, while some cooling oil is ejected from the inclined oil outlet hole 42 to cool the inner surface of the stator end winding at one end of the housing 1. Whether the rotor core 2 is rotating or stationary, the cooling oil can be directly returned to the system oil tank through the provided oil outlet.

[0049] An axial oil passage 21 is provided in the rotor core 2. The axial oil passage 21 is coaxially arranged with the axial oil hole 43 and is connected or directly axially connected. The axial oil passage 21 is connected with the axial oil outlet hole 51 provided in the second balance plate 5. The axial oil hole 43, the axial oil passage 21, the axial oil outlet hole 51 and the inclined oil outlet hole 42 form the free cooling oil circuit.

[0050] Specifically, the rotor shaft 7 is provided with a shoulder 74 located near the stationary oil circuit. The first balance plate 4, the rotor core 2, and the second balance plate 5 are sequentially arranged on the side of the shoulder 74 away from the stationary oil circuit. The rotor shaft 7 is also sleeved with a locking member 20. The locking member 20, together with the shoulder 74, clamps the second balance plate 5, the rotor core 2, and the first balance plate 4. Preferably, in this embodiment, the rotor core 2, the first balance plate 4, and the second balance plate 5 are press-fitted onto the rotor shaft 7 using an interference fit. Alternatively, the locking member 20 may be a nut.

[0051] Optionally, due to the process of forming, the bent oil passage 71 in the front is generally produced as an "F"-shaped pipe. In this case, a bearing (including a first bearing and a second bearing) is provided between the rotor shaft 7 and the housing 1. The end of the axial oil passage 713 close to the first radial oil passage 711 is connected to the outside world, resulting in leakage. In order to seal the axial oil passage 713, a ball blocking ball 10 is provided in the axial oil passage 713. The ball blocking ball 10 is provided between the first radial oil passage 711 and the bearing of the axial oil passage 713. Optionally, the ball blocking ball 10 is press-fitted into each axial oil passage 713 by interference fit. When the bent oil passage 71 in the front is a "]"-shaped pipe, the ball blocking ball 10 is not required.

[0052] Preferably, in this embodiment, the number of the bent oil passages 71, radial grooves 41, axial oil holes 43, inclined oil outlet holes 42, and axial oil passages 21 is the same as the number of poles of the rotor core 2, and is evenly distributed circumferentially. The purpose is to utilize the process holes of the rotor core 2 itself as the main heat exchange channel to efficiently cool the core and magnets, thereby reducing costs. Each pole of the rotor core 2 is provided with an axial oil passage 21, and the axial oil passage 21 can directly utilize the process holes of the rotor core 2 itself. For example, in a specific embodiment, the number of poles of the rotor core 2 is 6, then the number of the bent oil passages 71, axial oil passages 21, radial grooves 41, axial oil holes 43, and inclined oil outlet holes 42 are all 6, and are connected one by one to form 6 branch flow passages in series, so that the cooling of the rotor core 2 is more uniform.

[0053] The oil circuit structure of the oil-cooled motor rotor provided by the present invention is such that, under the action of oil pressure, cooling oil enters the static oil circuit, then the rotating oil circuit, and finally the free cooling oil circuit within the rotor core 2. It then flows out of the rotor core 2 by centrifugal force or accumulation, thereby cooling the interior of the rotor core 2. Compared with the prior art, on the one hand, the oil inlet of the static oil circuit 11 is provided on the static component (e.g., the housing 1), and the oil circuit is provided only on the shaft wall of the rotor shaft 7. There is no need to provide an oil inlet opening at the end opening of the rotor shaft 7, nor is there any need to use the internal cavity of the rotor shaft 7 as a cooling oil channel. On the other hand, oil pressure can be directly used to force oil into the entire cooling channel, without the need for centrifugal force to enter and cool the interior of the rotor core 2, thereby achieving efficient cooling of the rotor core 2 under all operating conditions. Furthermore, the oil reaching the interior of the rotor core 2 is unpressurized oil, flows slowly, and has a better cooling effect and higher efficiency.

[0054] In detail, the cooling oil enters the radial oil hole 31 from the oil inlet of the stationary oil circuit 11, then enters the annular oil distribution groove 32 and is distributed to several curved oil channels 71, and flows into the axial oil channel 21 in the rotor core 2 through the radial groove 41. The cooling oil in the axial oil channel 21 can cool the inside of the rotor core 2. Part of the cooling oil is thrown out from the axial oil outlet hole 51 to the inner surface of the stator end winding at the other end of the housing 1 for cooling, and part of the cooling oil is thrown out from the inclined oil outlet hole 42 to the inner surface of the stator end winding at one end of the housing 1 for cooling.

[0055] The present invention has the following beneficial effects:

[0056] (1) Using oil circuit pressure to spray cooling oil directly into the rotor core 2, it gets rid of the dependence on centrifugal force. The rotor core 2 can still be efficiently cooled when it is stationary and at low speed, eliminating the limitation of motor performance under certain working conditions.

[0057] (2) For applications where the end of the rotor shaft 7 is limited and it is difficult to arrange the oil inlet, this solution relies on the bushing 3 to radially inlet the oil at the non-end of the rotor shaft 7. A number of independent curved oil passages 71 opened on the shaft wall of the rotor shaft 7 directly lead the cooling oil to the interior of the rotor core 2. There is no need to set an oil inlet at the end opening of the rotor shaft 7, nor is there any need to use the internal cavity of the rotor shaft 7 as a cooling oil channel.

[0058] (3) A mechanical seal pressure storage structure is formed by using an expansion ring 8, which connects the oil inlet circuit from the housing 1 to the rotor core 2. The structure is compact, low cost, good economy and low friction.

[0059] The above are only preferred embodiments of the present invention and do not limit the implementation mode and protection scope of the present invention. For those skilled in the art, it should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. An oil circuit structure for an oil-cooled motor rotor, characterized in that: include: A housing, a bushing, a rotor core, a first balancing plate, a second balancing plate, a stator assembly and a rotor shaft; The rotor core, the bushing, the first balance plate and the second balance plate are all sleeved on the rotor shaft, the stator assembly is sleeved on the outside of the rotor core, and the housing is wrapped around the outer periphery of the stator assembly; One end of the bushing away from the rotor shaft abuts against the housing, the first balancing plate and the second balancing plate are respectively closely attached to two sides of the rotor core, and the bushing is arranged close to the first balancing plate; In which, an oil inlet is provided on the shell, an annular oil distribution groove and radial oil holes are provided in the bushing, the radial oil holes are connected to the annular oil distribution groove, and the oil inlet is connected to the radial oil holes. A plurality of bent oil channels are provided on the rotor shaft, one end of the bent oil channel is connected to the annular oil distribution groove, and the other end of the bent oil channel is connected to the radial groove provided in the first balance plate. A plurality of axial oil channels are provided in the rotor core, and the axial oil channel is connected to the axial oil outlet hole provided in the second balance plate. The first balance plate is also provided with an inclined oil outlet hole connected to the axial oil channel, and the axial oil channel is also connected to the radial groove, and the inclined oil outlet hole points to the stator assembly.

2. The oil circuit structure of the oil-cooled motor rotor according to claim 1, characterized in that: The bent oil passages, the radial grooves, the inclined oil outlet holes and the axial oil passages are uniformly distributed along the circumferential direction.

3. The oil circuit structure of the oil-cooled motor rotor according to claim 2, characterized in that: The curved oil passage includes a first radial oil passage, an axial oil passage, and a second radial oil passage. One end of the first radial oil passage is connected to the annular oil distribution groove, and the other end of the first radial oil passage is connected to the axial oil passage. One end of the second radial oil passage is connected to the radial groove, and the other end of the second radial oil passage is connected to the axial oil passage.

4. The oil circuit structure of the oil-cooled motor rotor according to claim 3, characterized in that: Two expansion ring-type sealing rings are provided between the rotor shaft and the bushing. Two annular grooves are provided on the rotor shaft. The two expansion ring-type sealing rings are installed in the two annular grooves. The first radial oil passage is provided between the two annular grooves.

5. The oil circuit structure of the oil-cooled motor rotor according to claim 4, characterized in that: The expansion ring type sealing ring is axially broken to form two free ends, and the two free ends can be movably overlapped.

6. The oil circuit structure of the oil-cooled motor rotor according to claim 5, characterized in that: A first bearing and a second bearing are arranged between the rotor shaft and the housing. The first bearing is arranged close to the bushing. The axial oil circuit arranged in the rotor shaft is connected to the area on the rotor shaft where the first bearing is installed. A ball blocking ball is arranged in the axial oil circuit close to the first bearing. The second bearing is arranged close to the second balance plate.

7. The oil circuit structure of an oil-cooled motor rotor according to any one of claims 1 to 6, characterized in that: An axial hole is further provided in the first balancing plate. The axial hole is communicated with the axial oil passage. The radial groove is communicated with the axial hole. The inclined oil outlet hole is communicated with the axial hole.

8. The oil circuit structure of an oil-cooled motor rotor according to any one of claims 1 to 6, characterized in that: The diameter of the axial oil outlet hole is larger than the diameter of the inclined oil outlet hole.

9. The oil circuit structure of an oil-cooled motor rotor according to any one of claims 1 to 6, characterized in that: The rotor shaft is provided with a shaft shoulder for axially positioning the rotor core, and the shaft shoulder is arranged close to the bushing. The rotor shaft is also sleeved with a locking piece for axially fixing the rotor core, and the locking piece is tightly against the second balance plate.

10. The oil circuit structure of an oil-cooled motor rotor according to any one of claims 1 to 6, characterized in that: It also includes a wheel half shaft, which is inserted into the rotor shaft.

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