Rotor oil cooling structure of motor and electric drive assembly system

Abstract

The invention discloses a rotor oil cooling structure of a motor and an electric drive assembly system, and relates to the technical field of permanent magnet synchronous motors, a rotor comprises a rotating shaft and a rotor iron core which are coaxially arranged, rotor pressing plates are arranged at the two ends of the rotor iron core, and the oil cooling structure comprises an oil inlet which is arranged on the rotating shaft so as to be connected with external oil; the inner cavities of the clockwise reciprocating oil way, the anticlockwise reciprocating oil way, the rotating shaft, the rotor pressing plates and the rotor iron core are respectively provided with oil liquid channels which are communicated with one another, and the rotating shaft is respectively provided with oil outlet holes which are opposite to the two rotor pressing plates; oil enters the corresponding rotor pressing plates from the oil outlet holes of the rotating shaft and is divided into at least two oil branches, so that a clockwise reciprocating oil way and an anticlockwise reciprocating oil way are formed in the rotor iron core with the de-weight hole structure, the oil branches are combined in the other rotor pressing plate, and then the oil branches are thrown to the end of the stator winding through the oil throwing holes formed in the rotating shaft. An oil way in the rotor is changed into a reciprocating oil way from a single-way structure, the oil way contact area is increased, and the cooling effect is more ideal.

Description

Technical Field

[0001] The present invention relates to the technical field of permanent magnet synchronous motors, and in particular to a rotor oil cooling structure and an electric drive assembly system of a motor. Background Art

[0002] With the widespread application of permanent magnet synchronous motors, higher requirements are also faced for motor cooling.

[0003] At present, there are two main cooling systems for permanent magnet synchronous motors:

[0004] The first type: There is no oil cooling channel in the rotor core, but there is an oil cooling channel on the shaft. When working, the cooling oil enters from the spline end of the shaft and sprays out from the oil cooling channels at both ends of the shaft core. The cooling oil is thrown onto the stator winding under the action of centrifugal force to take away the heat from the end of the stator winding.

[0005] Second: Please refer to Figure 1 There are oil cooling channels in the rotor core and the shaft. When working, the cooling oil enters from the spline end of the shaft, flows into the rotor pressure plate oil channel from the shaft opening, then flows into the rotor core from the pressure plate at one end, and finally is thrown out from the pressure plate at the other end of the rotor to take away the heat of the rotor core and magnetic steel.

[0006] However, the above two cooling systems have the following disadvantages:

[0007] In the current solution where the shaft is oiled but the core is not, the heat from the core and magnets needs to be transferred to the windings and air gaps before it can be taken away. As a result, the heat dissipation efficiency is low, which in turn causes the rotor temperature to be too high, resulting in the risk of magnet demagnetization under the peak operating conditions of the motor. In addition, excessively high rotor temperatures will accelerate the aging of some of the insulation materials in the stator, affecting the structural strength of the rotor.

[0008] In the current scheme where both the shaft and the core are oiled, the oil enters from the pressure plate at one end of the rotor and is thrown out from the pressure plate at the other end. On the one hand, due to the short cooling oil path inside the rotor core, the rotor core and the magnet cannot be fully cooled; on the other hand, the inner cavity of the shaft has a large space, and the rotor oil distribution cannot fill this cavity. Therefore, when the rotor rotates at high speed, it is easy to cause oil turbulence, resulting in further weakening of the cooling effect; at the same time, after passing through the rotor, the oil flies from the end face of the pressure plate into the cavity, and cannot effectively cool the end of the stator winding. Summary of the invention

[0009] The technical problem to be solved by the present invention is how to optimize the cooling system of the oil-cooled permanent magnet synchronous motor to solve the defects of the prior art.

[0010] In order to solve the above technical problems, the present invention provides a rotor oil cooling structure of a motor, wherein the motor comprises a stator and a rotor, wherein the rotor comprises a coaxially arranged rotating shaft and a rotor core, wherein both ends of the rotor core are provided with rotor pressure plates, and the rotor core is fixed to the rotating shaft through the rotor pressure plates, and the oil cooling structure comprises:

[0011] An oil inlet is provided on the rotating shaft to receive external oil;

[0012] The clockwise reciprocating oil circuit and the counterclockwise reciprocating oil circuit, the inner cavities of the rotating shaft, the rotor pressure plate and the rotor core are respectively provided with oil channels that are interconnected, and the rotating shaft is respectively provided with oil outlet holes opposite to the two rotor pressure plates; the oil enters the corresponding rotor pressure plates from the oil outlet holes of the rotating shaft, and is divided into at least two oil branches, so as to form the clockwise reciprocating oil circuit and the counterclockwise reciprocating oil circuit in the rotor core with the deweighting hole structure, and the oil branches are respectively merged in the other rotor pressure plate, and then sprayed to the end of the stator winding through the oil spraying holes provided on the rotating shaft.

[0013] Furthermore, the rotating shaft includes a spline section, an intermediate section and a rotational transformation section which are welded in sequence; the oil inlet is arranged at the spline section; and a first oil channel is arranged along the axis of the rotating shaft and from the spline section to the intermediate section.

[0014] Furthermore, the rotor pressure plates located at both ends of the rotor core are respectively recorded as the first rotor pressure plate and the second rotor pressure plate; the positions of the rotating shaft facing the first rotor pressure plate and the second rotor pressure plate are respectively provided with first oil channel oil outlet holes.

[0015] Furthermore, the inner cavity of the first rotor pressure plate is centrally symmetrically arranged with:

[0016] Interconnected second oil channels, wherein the second oil channels are respectively connected to second oil channel oil separation channels;

[0017] The fourth oil channels are interconnected, and the fourth oil channels are respectively connected to a fourth oil channel combined oil channel.

[0018] Furthermore, the inner cavity of the second rotor pressure plate is symmetrically arranged with:

[0019] Interconnected second oil channels, wherein the second oil channels are respectively connected to second oil channel oil separation channels;

[0020] The fourth oil channels are interconnected, and the fourth oil channels are respectively connected to a fourth oil channel combined oil channel.

[0021] Furthermore, a plurality of de-weighting holes are arranged at intervals along the axial direction of the rotor core to form a third oil channel, and the second oil channel and the fourth oil channel are respectively connected to the de-weighting holes of the rotor core.

[0022] Furthermore, the third oil channel is a through groove structure.

[0023] Furthermore, fifth oil channels are located in the middle section of the rotating shaft and are evenly arranged around the axis of the rotating shaft.

[0024] Furthermore, the middle section of the rotating shaft is also provided with:

[0025] a fifth oil channel oil inlet hole, the fifth oil channel oil inlet hole being connected to the fourth oil channel oil channel and the fifth oil channel respectively;

[0026] The fifth oil channel oil-swinging hole is directly opposite to the stator winding end and is connected to the fifth oil channel.

[0027] An electric drive assembly system comprises the rotor oil cooling structure of the motor.

[0028] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0029] 1. Compared with the existing oil-cooled rotor structure, the oil cooling structure of the motor designed by the present invention changes the oil path in the rotor from a single-path structure to a reciprocating oil path, and the one oil channel in the rotor cavity is changed to five oil channels, the contact area of ​​the oil path is increased, and the cooling effect is more ideal.

[0030] 2. According to the number of pole pairs of the motor, set the oil cooling channels twice the number of pole pairs to cool the magnetic steel of each pole, effectively reduce the rotor temperature and prevent demagnetization.

[0031] 3. For motors of the same power, rotors with oil cooling structures can use lower grades of magnetic steel than rotors without oil cooling structures, thereby greatly reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0033] Figure 1 It is a structural schematic diagram of an embodiment of the prior art of the present invention;

[0034] Figure 2A cross-sectional view of the overall structure of the rotor disclosed in an embodiment of the present invention;

[0035] Figure 3 A partial cross-sectional view of a rotating shaft in a rotor disclosed in an embodiment of the present invention;

[0036] Figure 4 The left view and the right view are the overall structure of the rotor disclosed in the embodiment of the present invention;

[0037] Figure 5 This is a diagram of the inner cavity structure of the first rotor pressure plate disclosed in an embodiment of the present invention;

[0038] Figure 6 A schematic diagram of the path of a clockwise reciprocating oil circuit disclosed in an embodiment of the present invention;

[0039] Figure 7 This is a schematic diagram of the path of the counterclockwise reciprocating oil circuit disclosed in an embodiment of the present invention.

[0040] In the figure:

[0041] 10. Rotor; 11. Pole slant positioning hole;

[0042] 100, rotating shaft; 110, first oil channel; 120, 130, oil outlet holes of the first oil channel;

[0043] 200, first rotor pressure plate; 210, 220, 230, 240, second oil channel; 250, second oil channel oil distribution channel;

[0044] 300, rotor core; 310, 320 third oil channel;

[0045] 400, second rotor pressure plate; 410, 420, 430, 440, fourth oil channel; 450, fourth oil channel combined oil channel;

[0046] 510, 520, 530, 540, fifth oil channel; 550, fifth oil channel oil inlet hole; 560, fifth oil channel oil throwing hole. DETAILED DESCRIPTION

[0047] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0048] The terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish different objects rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, device, product or end including a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units inherent to these processes, methods, products or ends.

[0049] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0050] The first aspect of the present invention is to provide a rotor oil cooling structure for a motor, which can increase the oil circuit contact area in the rotor cavity, thereby fully cooling the rotor core and magnetic steel.

[0051] It can be known from the common knowledge in this field that the motor includes a stator and a rotor 10; the rotor 10 includes a coaxially arranged shaft 100 and a rotor core 300; rotor pressure plates are provided at both ends of the rotor core 300, which are denoted as the first rotor pressure plate 200 and the second rotor pressure plate 400; the rotor core 300 is fixedly connected to the two ends of the shaft 100 through the positioning holes on the first rotor pressure plate 200 and the second rotor pressure plate 400 respectively.

[0052] The rotor oil cooling structure of the motor provided by the present invention mainly comprises an oil inlet, a clockwise reciprocating oil circuit, a counterclockwise reciprocating oil circuit and an oil throwing port.

[0053] See also Figure 2 The oil inlet is arranged on the rotating shaft 100 for receiving external oil. The inner cavities of the rotating shaft 100, the first rotor pressure plate 200, the rotor core 300 and the second rotor pressure plate 400 are respectively provided with oil channels that are interconnected, and the positions of the rotating shaft 100 facing the first rotor pressure plate 200 and the second rotor pressure plate 400 are respectively provided with oil outlet holes.

[0054] It is further explained that the oil enters the corresponding rotor pressure plate from the oil outlet holes of the rotating shaft 100 and is divided into at least two oil branches to form a clockwise reciprocating oil circuit and a counterclockwise reciprocating oil circuit in the rotor core 300 with a deweighting hole structure, and the oil branches are merged in the other rotor pressure plate respectively, and then sprayed to the end of the stator winding through the oil spray holes set in the rotating shaft 100.

[0055] The following is a main description of the clockwise reciprocating oil circuit and the counterclockwise reciprocating oil circuit formed in this embodiment and their related structures.

[0056] First, the rotating shaft 100 in this embodiment is described:

[0057] See also Figure 3 The rotating shaft 100 includes a spline section, an intermediate section and a rotational section which are welded in sequence.

[0058] In a further solution, the oil inlet is arranged on the spline section of the rotating shaft 100 .

[0059] In a further embodiment, a first oil channel 110 is provided along the axis of the rotating shaft 100 and from the spline section to the middle section.

[0060] In a further solution, first oil channel oil outlet holes 120 and 130 are respectively provided at positions of the rotating shaft 100 facing the first rotor pressure plate 200 and the second rotor pressure plate 400.

[0061] It is further explained that the oil entering from the oil inlet of the spline section of the rotating shaft 100 flows through the first oil channel 110, and is then vertically pumped into the corresponding first rotor pressure plate 200 and / or second rotor pressure plate 400 from the oil outlet holes 120 and 130 of the first oil channel, respectively, so as to take away the heat of the rotating shaft 100.

[0062] Next, the rotor pressure plate in this embodiment is described:

[0063] See also Figure 4-5 Two groups of oil passages are symmetrically arranged in the inner center of the first rotor pressure plate 200, which are recorded as the first rotor pressure plate oil separation passage and the first rotor pressure plate oil combination passage. Specifically:

[0064] The first rotor pressure plate oil distribution channel includes second oil channels 210 , 220 and a second oil channel oil distribution channel 250 respectively connected to one end of the second oil channels 210 , 220 .

[0065] The first rotor pressure plate combined oil passage includes fourth oil passages 410 , 420 and a fourth oil passage combined oil passage 450 which is connected to one end of the fourth oil passages 410 , 420 , respectively.

[0066] Similarly, the inner cavity of the second rotor pressure plate 400 is also centrally symmetrically arranged with two groups of oil passages, which are recorded as the second rotor pressure plate oil separation passage and the second rotor pressure plate oil combination passage. Specifically:

[0067] The second rotor pressure plate oil distribution channel includes second oil channels 230 , 240 and a second oil channel oil distribution channel 250 respectively connected to one end of the second oil channels 230 , 240 .

[0068] The second rotor pressure plate combined oil passage includes fourth oil passages 430 , 440 and a fourth oil passage combined oil passage 450 which is connected to one end of the fourth oil passages 430 , 440 , respectively.

[0069] Further explained is that the first rotor pressure plate 200 and the second rotor pressure plate 400 are both provided with oil separation channels and oil merging channels arranged symmetrically around the center of the circle. The end of the second oil channel oil separation channel 250 away from the second oil channels 210, 220, 230, 240 is closed; similarly, the end of the fourth oil channel merging channel 450 away from the fourth oil channels 410, 420, 430, 440 is closed. The first oil channel oil outlet holes 120, 130 are respectively adjacent to the second oil channel oil separation channel 250.

[0070] Those skilled in the art can understand that the oil passage structures arranged on the contact surfaces of the first rotor pressure plate 200 and the second rotor pressure plate 400 with the rotor core 300 are the same, and both have a pair of oil separation passages for oil separation and a pair of oil merging passages for oil merging. The purpose of this design is to improve the oil passage in the existing rotor from a single-pass structure to a reciprocating oil passage.

[0071] Next, the rotor core 300 in this embodiment is described:

[0072] A plurality of deweighting holes are arranged at intervals along the axial direction of the rotor core 300 to form third oil channels 310 , 320 .

[0073] Preferably, the third oil channels 310 and 320 are through-groove structures.

[0074] In a further solution, the second oil channels 210 , 220 , 230 , 240 and the fourth oil channels 410 , 420 , 430 , 440 are respectively connected to the deweighting holes of the rotor core 300 .

[0075] It is further explained that the third oil channels 310 and 320 utilize the de-weighting holes of the rotor core, and each section of the rotor core has a skewed pole structure, which can still form a through-slot oil circuit. The de-weighting hole structure is utilized to make the oil closer to the magnet without affecting the rotor flux.

[0076] It is further explained that since the second oil channels 210, 220, 230, 240 and the fourth oil channels 410, 420, 430, 440 are spaced apart around the axis of the rotating shaft 100, opposite balancing forces can be applied to the rotor core 300 during the flow of oil, thereby ensuring the dynamic balance of the rotor 10 during rotation.

[0077] See also Figure 6-7When the circulating cooling oil flows through the first oil channel 110, it takes away the heat of the rotating shaft 100, and then is pumped into the corresponding second oil channels 210, 220 in the first rotor pressure plate 200 and the second oil channels 230, 240 in the second rotor pressure plate 400 through the oil outlet holes 120, 130 of the first oil channel, and then the second oil channel oil dividing channels 250 in the first rotor pressure plate 200 and the second rotor pressure plate 400 respectively divide the oil entering each other into two independent paths, and the two independent paths of oil after division respectively enter the third oil channels 310, 320 in the rotor core 300. At this time, when the circulating cooling oil flows through the third oil channels 310, 320, it can take away the heat of the rotor core 300.

[0078] Finally, the fifth oil channel in this embodiment is described:

[0079] Fifth oil channels 510 , 520 , 530 , 540 are evenly arranged in the middle section of the rotating shaft 100 and around the axis of the rotating shaft 100 .

[0080] In a further embodiment, the middle section of the rotating shaft 100 is further provided with a fifth oil channel oil inlet hole 550 and a fifth oil channel oil ejection hole 560 .

[0081] It is further explained that the fifth oil channel oil inlet hole 550 is connected to the fourth oil channel oil channel 450 and the fifth oil channels 510, 520, 530, 540 respectively.

[0082] To further explain, the oil-swinging hole 560 of the fifth oil channel is directly opposite to the stator winding end and is connected to the fifth oil channels 510 , 520 , 530 , and 540 .

[0083] Those skilled in the art can understand that the cooling oil passes through the first oil channel 110, the first oil channel oil outlet, the second oil channel, the second oil channel oil separation channel 250, the third oil channel, the fourth oil channel, the fourth oil channel oil combining channel 450, the fifth oil channel oil inlet hole 550, the fifth oil channel, and the fifth oil channel oil throwing hole 560 in the rotating shaft 100 in sequence, so as to cool the rotating shaft 100, the rotor core 300, and the stator winding end.

[0084] The rotating shaft 100 in this embodiment is a hollow shaft and a three-section welded rotating shaft with a thick oil channel (i.e., the first oil channel 110) and four thin oil channels (i.e., the fifth oil channels 510, 520, 530, 540). Compared with the fully hollow rotating shaft 100, such a design can prevent the oil from rotating and flowing back in the cavity of the rotating shaft 100.

[0085] Compared with the oil circuit inside the rotor of the existing oil-cooled rotor structure, the present invention changes the single-channel structure to a reciprocating oil circuit structure, and designs the existing one oil channel in the rotor cavity to five oil channels in this embodiment, thereby increasing the contact area of ​​the oil circuit and achieving a better cooling effect.

[0086] In addition, compared with the oil throwing of the existing rotor, the oil throwing of this embodiment is oil cooled by the oil circuit, and the oil throwing temperature is lower, which can take away more heat from the stator winding and greatly improve the stator efficiency.

[0087] This embodiment can be further expanded as follows: the oil cooling channels of the rotor can be designed according to the number of pole pairs. For example, 3 pole pairs have 6 oil cooling channels; 4 pole pairs have 8 oil cooling channels; they are used to cool the magnetic steel of each pole, which can effectively reduce the rotor temperature and prevent demagnetization.

[0088] When the oil cooling structure provided in this embodiment is in operation, the oil pump drives the circulating cooling oil to enter from the oil inlet of the spline section of the rotating shaft 100; the circulating cooling oil can take away the heat of the rotating shaft 100 when flowing through the first oil channel 110; then enter the second oil channels 210 and 220 on the first rotor pressure plate 200 through the oil outlet hole 120 of the first oil channel; and then the oil is divided by the oil distribution channel 250 of the second oil channel to enter the third oil channels 310 and 320 of the rotor core 300 respectively. When the circulating cooling oil flows through the third oil channel, it can take away the heat of the rotor core 300. The oil then enters the fourth oil channel 430, 440 of the second rotor pressure plate 400; the oil in the fourth oil channel and the oil channel 450 are then combined to combine the branched oil; the combined oil enters the fifth oil channel 530, 540 on the rotating shaft 100 through the fifth oil channel inlet 550 on the rotating shaft 100. When the circulating cooling oil flows through the fifth oil channel, the heat brought by the rotor core 300 is transferred to the rotating shaft 100, and two clockwise reciprocating oil paths are formed in the rotor 10 (the other two are opposite counterclockwise reciprocating oil paths, which can be referred to in Figure 6 ); the cooled oil is then thrown out through the fifth oil channel oil-throwing hole 560, and under the influence of the centrifugal force of the rotor, the thrown circulating cooling oil is thrown on the end of the stator winding, further taking away the heat of the stator winding; finally, the oil flows back to the return oil tank and returns to the circulation system of the circulating cooling oil through the return oil channel.

[0089] The second aspect of the present invention is an electric drive assembly system, including the above-mentioned motor rotor oil cooling structure, which also belongs to the protection scope of the present invention. Moreover, for motors of the same power, the rotor with oil cooling structure can reduce the magnetic steel grade compared with the rotor without oil cooling structure, thereby greatly reducing the cost.

[0090] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A rotor oil cooling structure of a motor, the motor comprising a stator and a rotor (10), the rotor (10) comprising a coaxially arranged rotating shaft (100) and a rotor core (300), both ends of the rotor core (300) being provided with rotor pressure plates, the rotor core (300) being fixed to the rotating shaft (100) via the rotor pressure plates, characterized in that: The oil cooling structure comprises: An oil inlet is provided on the rotating shaft (100) to receive external oil; The clockwise reciprocating oil circuit and the counterclockwise reciprocating oil circuit are respectively provided with oil channels that are interconnected in the inner cavity of the rotating shaft (100), the rotor pressure plate, and the rotor core (300), and the rotating shaft (100) is respectively provided with oil outlet holes facing the two rotor pressure plates; the oil enters the corresponding rotor pressure plates from the oil outlet holes of the rotating shaft (100) and is divided into at least two oil branches, so as to form the clockwise reciprocating oil circuit and the counterclockwise reciprocating oil circuit in the rotor core (300) with a deweighting hole structure, and the oil branches are respectively merged in the other rotor pressure plate, and then thrown to the end of the stator winding through the oil throwing holes provided on the rotating shaft (100).

2. The rotor oil cooling structure of the motor according to claim 1, characterized in that: The rotating shaft (100) comprises a spline section, an intermediate section and a rotational variable section which are welded in sequence; the oil inlet is arranged at the spline section; and a first oil channel (110) is arranged along the axis of the rotating shaft (100) and from the spline section to the intermediate section.

3. The rotor oil cooling structure of the motor according to claim 1, characterized in that: The rotor pressure plates located at both ends of the rotor core (300) are respectively referred to as a first rotor pressure plate (200) and a second rotor pressure plate (400); and first oil outlet holes (120, 130) are respectively provided at positions of the rotating shaft (100) facing the first rotor pressure plate (200) and the second rotor pressure plate (400).

4. The rotor oil cooling structure of the motor according to claim 3, characterized in that: The inner cavity of the first rotor pressure plate (200) is symmetrically arranged with: Second oil channels (210, 220) are interconnected, and the second oil channels (210, 220) are respectively connected to second oil channel oil separation channels (250); The fourth oil channels (410, 420) are interconnected, and the fourth oil channels (410, 420) are respectively connected to a fourth oil channel combined oil channel (450).

5. The rotor oil cooling structure of the motor according to claim 4, characterized in that: The inner cavity of the second rotor pressure plate (400) is symmetrically arranged with: Second oil channels (230, 240) are interconnected, and the second oil channels (230, 240) are respectively connected to second oil channel oil separation channels (250); The fourth oil channels (430, 440) are interconnected, and the fourth oil channels (430, 440) are respectively connected to a fourth oil channel combined oil channel (450).

6. The rotor oil cooling structure of the motor according to claim 1, characterized in that: A plurality of de-weighting holes are arranged at intervals along the axial direction of the rotor core (300) to form a third oil channel (310, 320), and the second oil channel (210, 220, 230, 240) and the fourth oil channel (410, 420, 430, 440) are respectively connected to the de-weighting holes of the rotor core (300).

7. The rotor oil cooling structure of the motor according to claim 6, characterized in that: The third oil channel (310, 320) is a through groove structure.

8. The rotor oil cooling structure of the motor according to claim 5, characterized in that: Fifth oil channels (510, 520, 530, 540) are located in the middle section of the rotating shaft (100) and are evenly arranged around the axis of the rotating shaft (100).

9. The rotor oil cooling structure of the motor according to claim 8, characterized in that: The middle section of the rotating shaft (100) is also provided with: a fifth oil channel oil inlet hole (550), the fifth oil channel oil inlet hole (550) being respectively connected to the fourth oil channel oil channel (450) and the fifth oil channel (510, 520, 530, 540); A fifth oil channel oil-swinging hole (560), the fifth oil channel oil-swinging hole (560) is directly opposite to the stator winding end and is connected to the fifth oil channel (510, 520, 530, 540).

10. An electric drive assembly system, characterized in that: A rotor oil cooling structure for a motor comprising the rotor oil cooling structure of any one of claims 1 to 9.

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