Motor rotor

Abstract

The present invention relates to the technical field of motors. Disclosed is a motor rotor, the motor rotor comprising an iron core structure and a rotating shaft; a central hole penetrates through the center of an end surface of the iron core structure in the axial direction, the hole wall of the central hole of the iron core structure being provided with a plurality of cooling recesses in the circumferential direction thereof, and each cooling recess extending in the axial direction of the iron core structure and penetrating through the iron core structure; the rotating shaft passes through the central hole and is fixedly connected to the iron core structure, and the rotating shaft and the plurality of cooling recesses together define a plurality of first flow channels, the first flow channels being used for allowing a cooling medium flowing out of a reducer of a motor to pass through. In the technical solution of the present invention, the plurality of cooling recesses and the rotating shaft jointly define the first flow channels, and when the cooling medium flows through the first flow channels, the part of the iron core structure close to the central hole and the rotating shaft are efficiently cooled, thereby reducing the thermal deformation of rotors, improving the operation stability of rotors, and reducing the wear and noise generation of rotors.

Description

A motor rotor TECHNICAL FIELD

[0001] The present application relates to the technical field of electric machines, in particular to a motor rotor. BACKGROUND

[0002] With the rapid development of the new energy automobile industry, permanent magnet synchronous motors are increasingly widely used in the field of new energy automobiles. With the development of technology, the power density and rotational speed of the motor are also increasing, which puts new requirements on the cooling of the motor rotor. When the motor rotor rotates at high speed, eddy current loss is generated, which causes the rotor to heat up, and thus the magnetic properties of the magnetic steel are reduced, resulting in a decrease in the torque, power and demagnetization resistance of the motor.

[0003] The existing motor is provided with a weight-reducing hole penetrating through the rotor core in the axial direction. When cooling, the cooling medium passes through the weight-reducing hole for cooling. If the effect is not good, it will cause thermal deformation of the rotor, thereby generating additional vibration during movement, reducing the working efficiency of the equipment, and aggravating the wear of the rotor. Moreover, since the motor rotor is a special structure formed by stacking rotor punching sheets, there are fewer channels through which the cooling medium can pass, and the cooling method of the motor rotor is single and the cooling effect is not good. SUMMARY

[0004] The main purpose of the present application is to provide a motor rotor, which aims to achieve good cooling effect.

[0005] To achieve the above-mentioned purpose, the motor rotor provided by the present application comprises a core structure and a rotating shaft. A central hole is provided through the center of the end face of the core structure in the axial direction. A plurality of cooling grooves are arranged on the hole wall of the central hole of the core structure in the circumferential direction. Each cooling groove extends in the axial direction of the core structure and penetrates through the core structure. The rotating shaft is fixedly connected to the core structure through the central hole. The rotating shaft and the plurality of cooling grooves jointly define a plurality of first flow channels. The first flow channels are used for the cooling medium flowing out of the reducer of the motor to pass through.

[0006] In an embodiment, the end face of the core structure in the axial direction is provided with a plurality of second hole groups and a plurality of third hole groups. The plurality of second hole groups and the plurality of third hole groups are alternately arranged along the circumferential side of the central hole. Each second hole group comprises two second flow channels penetrating through the core structure in the axial direction of the core structure. Each third hole group comprises two third flow channels penetrating through the core structure in the axial direction of the core structure. The fluid flow direction of the second flow channel is opposite to that of the third flow channel. Each second flow channel and each third flow channel are in communication with the first flow channel.

[0007] In an embodiment, the motor rotor further comprises two magnetic isolation plates, which are oppositely arranged at the two ends of the core structure along the axial direction of the core structure and abut against the core structure, and at least one first communication groove and a plurality of second communication grooves are formed on the end faces of the two magnetic isolation plates facing each other, the first communication groove is located in the middle of the magnetic isolation plate and communicates with the first flow channel, and part of the plurality of second communication grooves communicates with the second flow channel and the remaining part communicates with the third flow channel; the two magnetic isolation plates comprise a first magnetic isolation plate and a second magnetic isolation plate, in the first magnetic isolation plate, the plurality of second communication grooves communicating with the second flow channel are provided with a communication groove channel between the first communication groove, and the plurality of second communication grooves communicating with the third flow channel are provided in a through manner, in the second magnetic isolation plate, the plurality of second communication grooves communicating with the third flow channel are provided with a communication groove channel between the first communication groove, and the plurality of second communication grooves communicating with the second flow channel are provided in a through manner.

[0008] In an embodiment, each second communication groove communicates with two second flow channels in the second hole group or two third flow channels in the third hole group.

[0009] In an embodiment, the size of the second communication groove is matched with the size of the corresponding second flow channel or third flow channel.

[0010] In an embodiment, the cross-sectional area of the second communication groove provided in a through manner is arranged to decrease along the fluid flow direction.

[0011] In an embodiment, the rotating shaft has an inlet flow channel extending along the axial direction of the rotating shaft, and a plurality of radial distribution holes are formed on the circumferential side of the rotating shaft, and each radial distribution hole respectively communicates with the first flow channel and the inlet flow channel.

[0012] In an embodiment, the rotating shaft is provided with a front bearing inclined oil hole and a rear bearing inclined oil hole at the positions of the two ends arranged in the axial direction of the rotating shaft, one end of the front bearing inclined oil hole communicates with the inlet flow channel, and the other end is used to correspond to the front bearing of the motor, one end of the rear bearing inclined oil hole communicates with the inlet flow channel, and the other end is used to correspond to the rear bearing of the motor.

[0013] In an embodiment, the core structure comprises a core and a plurality of magnetic steels; the core forms a plurality of magnetic steel holes, and a center hole is arranged in the middle of the core; the plurality of magnetic steels are inserted into the plurality of magnetic steel holes one by one, and each magnetic steel and the hole wall of the magnetic steel hole jointly define a second flow channel or a third flow channel.

[0014] In an embodiment, each magnetic steel comprises a plurality of magnetic steel segments arranged in a staggered manner along the axial direction of the core structure.

[0015] The technical scheme of the present application defines the first flow channel by the plurality of cooling grooves and the rotating shaft, and when the cooling medium flows through the first flow channel, the position of the core structure close to the center hole and the rotating shaft are well cooled, so as to reduce the thermal deformation of the rotor, improve the operation stability of the rotor, and reduce the wear and noise of the rotor. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed in the embodiments or prior art description. Obviously, the drawings described below are only some of the embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from the structures shown in the drawings without creative labor.

[0017] Fig. 1 is a schematic diagram of the overall structure of an embodiment of the motor rotor provided by the present application;

[0018] Fig. 2 is an axial sectional view of the motor rotor in Fig. 1;

[0019] Fig. 3 is a sectional schematic diagram of the rotating shaft in Fig. 1;

[0020] Fig. 4 is a sectional schematic diagram of the core structure in Fig. 1;

[0021] Fig. 5 is a schematic diagram of the structure of the first magnetic isolation plate in Fig. 1;

[0022] Fig. 6 is a schematic diagram of the flow direction of the cooling medium in an embodiment of the motor rotor provided by the present application.

[0023] Reference signs: 100, motor rotor; 1, core structure; 11, core; 111, center hole; 112, cooling groove; 113, first flow channel; 114, magnetic steel hole; 115, second flow channel; 116, third flow channel; 117, small round hole; 118, weight-reducing hole; 118A, mark groove; 12, magnetic steel; 2, rotating shaft; 21, inflow passage; 22, radial flow dividing hole; 23, front bearing inclined oil hole; 24, rear bearing inclined oil hole; 3, magnetic isolation plate; 31, first communication groove; 32, communication channel; 331, second communication groove (through); 332, second communication groove (not through); 34, positioning groove.

[0024] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, and not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0026] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, motion condition, etc. between components in a certain posture, and if the certain posture changes, the directional indications will also change accordingly.

[0027] In addition, if the embodiments of the present application involve descriptions such as "first", "second", etc., the descriptions of "first", "second", etc. are only for description purposes and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In addition, "and / or" or "and / or" appearing throughout the text means that the three parallel schemes are included, for example, "A and / or B" includes A scheme, or B scheme, or A and B are satisfied at the same time. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of ordinary skilled persons in the art, and when the combination of technical solutions contradicts each other or cannot be realized, it should be considered that the combination of technical solutions does not exist and is not within the protection scope required by the present application.

[0028] With the rapid development of the new energy automobile industry, permanent magnet synchronous motors are increasingly widely used in the field of new energy automobiles. With the development of technology, the power density and speed of the motor are also increasing, which puts new requirements on the cooling of the motor rotor. When the motor rotor rotates at high speed, eddy current loss will be generated, which will heat the rotor, and then the magnetic properties of the magnetic steel will decrease, resulting in a decrease in the torque, power and demagnetization resistance of the motor.

[0029] The existing motor is provided with a weight-reducing hole penetrating through the rotor core in the axial direction. When cooling, the cooling medium passes through the weight-reducing hole for cooling. If the effect is not good, it will cause thermal deformation of the rotor, thereby generating additional vibration during movement, reducing the working efficiency of the equipment, and aggravating the wear of the rotor. In addition, since the motor rotor is a special structure formed by stacking rotor punching sheets, there are fewer channels through which the cooling medium can pass, and the cooling method of the motor rotor is single.

[0030] Based on this, the present application provides a motor rotor 100 to achieve good cooling effect.

[0031] In an embodiment of the present application, referring to FIG. 1, FIG. 2 and FIG. 4, the motor rotor 100 comprises a core structure 1 and a rotating shaft 2; the core structure 1 is provided with a central hole 111 at the center of the end face arranged along the axial direction thereof, the hole wall of the central hole 111 of the core structure 1 is provided with a plurality of cooling grooves 112 along the circumferential direction thereof, each of the cooling grooves 112 extends along the axial direction of the core structure 1 and penetrates the core structure 1; the rotating shaft 2 is fixedly connected with the core structure 1 through the central hole 111, and the rotating shaft 2 and the plurality of cooling grooves 112 jointly define a plurality of first flow channels 113, which are used for the cooling medium of the reducer outflow of the motor to pass through.

[0032] The technical scheme of the present application jointly defines the first flow channels 113 by the plurality of cooling grooves 112 and the rotating shaft 2, and the cooling medium flowing through the first flow channels 113 can well cool the position of the core structure 1 close to the central hole 111 and the rotating shaft 2, so as to reduce the thermal deformation of the rotor, improve the operation stability of the rotor, and reduce the wear and noise of the rotor.

[0033] It should be noted that the shape and size of the cooling grooves 112 are not limited, and the cross section thereof can be square, arc or other shapes, and when the shape and size thereof are designed, the motor rotor 100 should be able to achieve good cooling effect and meet the strength requirement of the motor rotor 100.

[0034] It should be noted that the size of the central hole 111 should be matched with the size of the rotating shaft 2 to achieve interference fit for reliable connection. The flow channel is the passage of the cooling medium, and the cooling medium includes air, cooling oil, water-based solution or other fluids. The cooling medium of the reducer outflow of the motor is the cooling medium outflowing for cooling the external spline of the reducer, and the connection mode of the reducer of the motor and the first flow channels 113 is not limited in the embodiment.

[0035] In an embodiment of the present application, referring to FIG. 4 and FIG. 6 (the arrow direction is the flow direction of the cooling medium), the end surface of the core structure 1 arranged along the axial direction is provided with a plurality of second hole groups and a plurality of third hole groups, and the plurality of second hole groups and the plurality of third hole groups are arranged alternately along the circumferential side of the central hole 111; each second hole group includes two second flow channels 115 penetrating the core structure 1 along the axial direction of the core structure 1, and each third hole group includes two third flow channels 116 penetrating the core structure 1 along the axial direction of the core structure 1, the fluid flow direction of the second flow channel 115 is opposite to the fluid flow direction of the third flow channel 116; each second flow channel 115 and each third flow channel 116 are in communication with the first flow channel 113. In this way, the cooling medium cools the inside of the core structure when passing through the first flow channel 113, and cools the circumferential side of the central hole 111 when passing through the second flow channel 115 or the third flow channel 116. The first flow channel 113, the second flow channel 115 and the third flow channel 116 all penetrate along the axial direction of the core structure 1, providing longer and more tortuous cooling flow channels, and having good heat dissipation effect; the cooling medium in the second flow channel 115 flows from one end of the motor rotor 100 to the other end, along the direction of the cooling medium flow, the temperature of the cooling medium gradually increases, and the cooling medium in the adjacent third flow channel 116 is opposite to the cooling medium in the second flow channel 115 in flow direction, achieving convection, along the flow direction of the cooling medium in the third flow channel 116, the temperature of the cooling medium also gradually increases, so that the temperature of the cooling medium is uniformly distributed along the axial direction of the motor, and the motor rotor 100 is uniformly cooled.

[0036] Specifically, in each second hole group, the two second flow channels 115 are arranged close to each other along the direction from the edge of the core structure 1 towards the center of the core structure 1; in each third hole group, the two third flow channels 116 are arranged close to each other along the direction from the edge of the core structure 1 towards the center of the core structure 1, and on the cross section of the core structure 1, the two second flow channels 115 in the second hole group or the two third flow channels 116 in the third hole group form a "V" shape.

[0037] In one embodiment of the present application, referring to FIG. 5 and FIG. 6, the motor rotor 100 further comprises two magnetic isolation plates 3, which are oppositely arranged at the two ends of the core structure 1 along the axial direction of the core structure 1 and abut against the core structure 1. The end faces of the two magnetic isolation plates 3 facing each other are formed with a first communication groove 31 and a plurality of second communication grooves. The first communication groove 31 is located in the middle of the magnetic isolation plate 3 and communicates with the first flow channel 113. Part of the plurality of second communication grooves communicates with the second flow channel 115, and the remaining part communicates with the third flow channel 116. The two magnetic isolation plates 3 comprise a first magnetic isolation plate and a second magnetic isolation plate. In the first magnetic isolation plate, the plurality of second communication grooves 332 communicating with the second flow channel 115 are provided with a communication groove channel 32 between the first communication groove 31, and the plurality of second communication grooves 331 communicating with the third flow channel 116 are provided in a through manner. In the second magnetic isolation plate, the plurality of second communication grooves 332 communicating with the third flow channel 116 are provided with a communication groove channel 32 between the first communication groove 31, and the plurality of second communication grooves 331 communicating with the second flow channel are provided in a through manner. In this way, the cooling medium has two flow directions. One flow direction is: sequentially passing through the first flow channel 113, the first communication groove 31 on the first magnetic isolation plate, the communication groove channel 32 on the first magnetic isolation plate, the second communication groove 332 on the first magnetic isolation plate, the third flow channel 116, and the second communication groove 331 provided in a through manner on the second magnetic isolation plate. The other flow direction is: sequentially passing through the first flow channel 113, the first communication groove 31 on the second magnetic isolation plate, the communication groove channel 32 on the second magnetic isolation plate, the second communication groove 332 on the second magnetic isolation plate, the second flow channel 115, and the second communication groove 331 provided in a through manner on the first magnetic isolation plate, so as to realize the convection of the cooling medium. The second communication groove 331 provided in a through manner is located at the end face of the two magnetic isolation plates 3 and is thrown into the inside of the winding of the motor stator when flowing out, so as to also realize the bidirectional cooling of the winding of the motor stator.

[0038] Specifically, the first magnetic isolation plate is the same as the second magnetic isolation plate, but when installed, the second communication groove 331 provided in a through manner on the first magnetic isolation plate is oppositely arranged with the second communication groove 332 not provided in a through manner on the second magnetic isolation plate, and the second communication groove 332 not provided in a through manner on the first magnetic isolation plate is oppositely arranged with the second communication groove 331 provided in a through manner on the second magnetic isolation plate.

[0039] In one feasible embodiment, the magnetic isolation plate 3 is formed with a ring-shaped first communication groove 31, and one first communication groove 31 communicates with a plurality of first flow channels 113. In this way, the cooling medium of the plurality of first flow channels 113 is mixed when entering the same communication groove, and has the same temperature when being again divided into each second flow channel 115 or third flow channel 116, so as to realize uniform cooling.

[0040] In another possible implementation, a plurality of first communication grooves 31 are formed on the magnetic isolation plate 3, each of the first communication grooves 31 corresponds to a first flow channel 113, and the first flow channel 113 corresponds to a second flow channel 115 or a third flow channel 116 opposite to the first flow channel 113 with the rotating shaft 2 as the center, a second communication groove 332 not penetrating through communicates the second flow channel 115 or the third flow channel 116 corresponding to the first flow channel 113, and a communication channel 32 extends on the magnetic isolation plate 3 to communicate the second communication groove 332 and the second communication groove 33. If the motor rotor 100 is unevenly heated, the left part of the motor rotor 100 with the rotating shaft 2 as the center is high in heat generation, and the right part is low in heat generation. In this way, the cooling medium flowing through the first flow channel 113 of the left part of the motor rotor 100 flows to the second flow channel 115 or the third flow channel 116 of the right part of the motor rotor 100, and the cooling medium flowing through the first flow channel 113 of the right part of the motor rotor 100 flows to the second flow channel 115 or the third flow channel 116 of the right part of the motor rotor 100, so that uniform heat dissipation can be achieved, and the communication channel 32 is long, and the communication channel 32 can also cool the end of the battery cell structure.

[0041] Further, the motor rotor 100 is further provided with a weight-reducing hole 118 penetrating through the battery cell structure in the axial direction between the central hole 111 and the second flow channel 115 or the third flow channel 116, and the weight-reducing hole 118 communicates with the first communication groove 31 to further cool the motor rotor 100.

[0042] In an embodiment of the present application, each second communication groove communicates with two second flow channels 115 in a second hole group or two third flow channels 116 in a third hole group. In this way, the two second flow channels 115 in each second hole group communicate with the same second communication groove at one end, and the two third flow channels 116 in each third hole group communicate with the same second communication groove at one end.

[0043] The number of second communication grooves on the first magnetic isolation plate and the second magnetic isolation plate is reduced, the energy loss of the cooling medium is reduced, and the process difficulty is reduced.

[0044] In an embodiment of the present application, the size of the second communication groove is matched with the size of the corresponding second flow channel 115 or third flow channel 116. In this way, the cooling medium of the second flow channel 115 or the third flow channel 116 has smaller pressure loss when entering the second communication groove, and the cooling medium of the second communication groove has smaller pressure loss when entering the second flow channel 115 or the third flow channel 116, so that the pressure requirement of the cooling medium entering the motor rotor 100 is reduced.

[0045] In an embodiment, two second flow channels 115 in each second hole group or two third flow channels 116 in each third hole group correspond to one second communication groove, the cross-sectional size of the second communication groove is equal to the cross-sectional size of the two second flow channels 115 or the cross-sectional size of the two third flow channels 116, and the second communication groove can smoothly communicate with the two second flow channels 115 or the two third flow channels 116 at the same time.

[0046] In an embodiment, the cross-sectional area of the second communication groove 331 is arranged to decrease along the fluid flow direction. In this way, the flow rate of the cooling medium flowing out of the second communication groove 331 can be increased, and the temperature of the cooling medium flowing out can be reduced, so that the cooling medium has a desired flow rate and temperature to cool the winding.

[0047] In an embodiment, the second communication groove 331 has a first groove section and a second groove section away from the core structure 1, the size of the first groove section is adapted to the size of the corresponding second flow channel 115 or third flow channel 116, and the size of the second groove section is smaller than that of the first groove section.

[0048] In another embodiment, the cross-sectional area of the second communication groove 331 gradually decreases along the fluid flow direction, and the cross-sectional area of the second communication groove 331 near the core 11 is adapted to the size of the corresponding second flow channel 115 or third flow channel 116.

[0049] In an embodiment, referring to FIG. 2, the rotating shaft 2 has an inlet channel 21 extending along the axial direction of the rotating shaft 2, and a plurality of radial distribution holes 22 are arranged on the circumferential side of the rotating shaft 2, and each radial distribution hole 22 is in communication with the first flow channel 113 and the inlet channel 21. In this way, the cooling medium flows into the first flow channel 113 through the radial distribution hole 22 after passing through the inlet channel 21, so that the cooling medium is uniformly distributed.

[0050] It should be noted that the rotating shaft 2 has an output end, and the inlet channel 21 of the output end of the rotating shaft 2 is provided with an internal spline, and the internal spline is matched with an external spline of a speed reducer, and the cooling medium flowing out of the external spline of the speed reducer enters the inlet channel 21 of the rotating shaft 2.

[0051] In an embodiment, one end of the radial distribution hole 22 is in communication with the center position of the hole section of the first flow channel 113, so that the flow length of the cooling medium flowing along the first flow channel 113 to the two ends of the rotating shaft 2 (the length from the radial distribution hole 22 to the second flow channel 115 and the length from the radial distribution hole 22 to the third flow channel 116) is equal, so that uniform cooling is achieved.

[0052] Please refer to Fig. 6, in an embodiment of the present application, the rotating shaft 2 is provided with a front bearing inclined oil hole 23 and a rear bearing inclined oil hole 24 at the two ends thereof along the axial direction, one end of the front bearing inclined oil hole 23 is communicated with the flow inlet channel 21, and the other end is used to correspond to the front bearing of the motor, one end of the rear bearing inclined oil hole 24 is communicated with the flow inlet channel 21, and the other end is used to correspond to the rear bearing of the motor. In this way, while the motor rotor 100 is oil-cooled, the lubricating oil is divided into two flows through the front bearing inclined oil hole 23 and the rear bearing inclined oil hole 24, and the front bearing and the rear bearing are lubricated respectively.

[0053] The cooling medium is selected as lubricating oil.

[0054] It should be noted that the front bearing and the rear bearing of the motor are sleeved on the two ends of the rotating shaft 2 along the axial direction, and are used to support the rotating shaft 2 and reduce the friction when the rotating shaft 2 rotates.

[0055] In an embodiment of the present application, please refer to Fig. 4, the core 11 is formed with a plurality of magnetic steel holes 114, and the core 11 is provided with a central hole 111 at the middle part thereof; a plurality of magnetic steels 12 are inserted into the plurality of magnetic steel holes 114 one by one, and each magnetic steel 12 and the hole wall of the magnetic steel hole 114 jointly define a second flow channel 115 or a third flow channel 116. In this way, the hole wall of the magnetic steel hole 114 and the magnetic steel 12 jointly define the second flow channel 115 or the third flow channel 116, so that the cooling medium can directly contact the magnetic steel 12 for cooling, and the cooling effect on the magnetic steel 12 is improved.

[0056] Correspondingly, when the core structure 1 is assembled, the magnetic steel 12 groove cannot be injection molded, and the magnetic steel 12 needs to be installed in the magnetic steel 12 groove of the rotor core 11 through gluing or mechanical fixing, so as to leave space to form the second flow channel 115 or the third flow channel 116.

[0057] In an embodiment of the present application, each magnetic steel 12 includes a plurality of magnetic steel segments which are arranged in a staggered manner along the axial direction of the core structure 1. In this way, the plurality of magnetic steel segments are arranged in a staggered manner, the contact area between the cooling medium in the second flow channel 115 or the third flow channel 116 and the magnetic steel 12 groove is larger, and the cooling effect is better.

[0058] Further, along the axial direction of the core 11, the plurality of magnetic steel 12 grooves are arranged in a staggered manner, and a "V" shaped magnetic pole is formed on the axial interface of the core structure 1.

[0059] Specifically, during assembly, the core 11 is formed by stacking a plurality of stamping sheets along the axial direction of the stamping sheet, and a plurality of magnetic steel segments are formed by interleaving a plurality of the core 11 along the axial direction of the core 11.

[0060] Referring to Fig. 4, the punching sheet has two mutually perpendicular center lines (the center lines are indicated by arrows without marks in the figure), the rotor core 11 has two pairs of small holes 117, one pair of which is at an angle a with the center line (the direction of the line connecting the two small holes is indicated by an arrow with mark a in the figure), and the other pair of which is at an angle b with the other center line (the direction of the line connecting the two small holes is indicated by an arrow with mark b in the figure); the punching sheet has a plurality of lightening holes 118, in the direction along the line connecting the pair of small holes 117 at angle a, the lightening hole 118 has two mark grooves 118A, and in the direction along the line connecting the pair of small holes 117 at angle b, the lightening hole 118 has one mark groove 118A, the position of the mark groove 118A is not on the symmetrical center line, so as to determine the front and back of the punching sheet; and a pair of positioning grooves 34 are arranged on the inner end surface of the magnetic shield plate 3 close to the core structure 1. In this way, when the first stack of cores 11 is assembled and pressed, the pair of small holes 117 at angle a is aligned with the positioning groove 34 of the magnetic shield plate 3; when the second stack of cores 11 is pressed, the pair of small holes 117 at angle b is aligned with the positioning groove 34 of the magnetic shield plate 3; when the third stack of cores 11 is pressed, the core 11 is first turned over, and then the pair of small holes 117 at angle b is aligned with the positioning groove 34 of the magnetic shield plate 3; when the fourth stack of cores 11 is pressed, the core 11 is first turned over, and then the pair of small holes 117 at angle a is aligned with the positioning groove 34 of the magnetic shield plate 3; the fifth stack is the same as the fourth stack, the sixth stack is the same as the third stack, the seventh stack is the same as the second stack, and the eighth stack is the same as the first stack. In this way, the motor rotor 100 forms a plurality of stacks of cores 11 with the angle of the line connecting the small holes 117 and the positioning groove 34 of the magnetic shield plate 3 being a, b, -b, -a, -a, -b, b, and a in turn, and forms a plurality of magnetic steel segments staggered, i.e. a "V"-shaped inclined pole. When the second magnetic shield plate is stacked and pressed, it is rotated by 90° relative to the first magnetic shield plate, so that it is aligned with the pair of small holes 117 at angle b on the eighth stack of cores 11 and the positioning groove 34 of the magnetic shield plate 3, and finally the steel ring is pressed into the rotating shaft 2, and the motor rotor 100 is axially fixed and compressed through interference fit.

[0061] In an embodiment of the present application, four second hole groups and four third hole groups are alternately arranged along the circumferential side of the central hole 111, the second hole group is formed by inserting two N-pole magnetic steels 12 into corresponding magnetic steel holes 114, and the third hole group is formed by inserting two S-pole magnetic steels 12 into corresponding magnetic steel holes 114. Correspondingly, four through second communication grooves 331 and four non-through second communication grooves 332 are arranged on each magnetic separation plate 3. The one end of each second hole group corresponding to the N-pole magnetic steel 12 is in communication with one non-through second communication groove 332 on the first magnetic separation plate, and the other end is in communication with one through second communication groove 331 on the second magnetic separation plate. The one end of each third hole group corresponding to the S-pole magnetic steel 12 is in communication with one non-through second communication groove 332 on the second magnetic separation plate, and the other end is in communication with one through second communication groove 331 on the first magnetic separation plate.

[0062] Thus, the cooling medium has the following flow direction:

[0063] 1. The outer spline central hole of the speed reducer - the inlet flow passage 21 - the radial flow distribution hole 22 - the first flow channel 113 - the first communication groove 31 on the first magnetic separation plate - the communication groove channel 32 on the first magnetic separation plate - the non-through second communication groove 332 on the first magnetic separation plate - the second hole group corresponding to the N-pole magnetic steel - the through second communication groove 331 on the second magnetic separation plate - the cooling stator winding on the side of the second magnetic separation plate;

[0064] 2. The outer spline central hole of the speed reducer - the inlet flow passage 21 - the radial flow distribution hole 22 - the first flow channel 113 - the first communication groove 31 on the second magnetic separation plate - the communication groove channel 32 on the second magnetic separation plate - the non-through second communication groove 332 on the second magnetic separation plate - the second hole group corresponding to the N-pole magnetic steel - the through second communication groove 331 on the first magnetic separation plate - the cooling stator winding on the side of the first magnetic separation plate;

[0065] 3. The outer spline central hole of the speed reducer - the inlet flow passage 21 - the front bearing inclined oil hole 23;

[0066] 4. The outer spline central hole of the speed reducer - the inlet flow passage 21 - the rear bearing inclined oil hole 24.

[0067] The above description is only an exemplary embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structural transformation made by using the content of the present application specification and drawings, or direct / indirect application in other related technical fields is included in the patent protection scope of the present application.

Claims

1. An electric machine rotor, characterized in that, The motor rotor comprises: an iron core structure, a center hole is provided through the center of the end surface of the iron core structure in the axial direction, and a plurality of cooling grooves are provided on the hole wall of the center hole of the iron core structure in the circumferential direction, each of the cooling grooves extends in the axial direction of the iron core structure and is provided through the iron core structure; and a rotating shaft, which is fixedly connected with the iron core structure through the center hole, and defines a plurality of first flow channels with the plurality of cooling grooves, the first flow channels being used for the cooling medium flowing out of the reducer of the motor.

2. The motor rotor of claim 1, wherein The end surface of the iron core structure in the axial direction is provided with a plurality of second hole groups and a plurality of third hole groups, the plurality of second hole groups and the plurality of third hole groups are alternately arranged along the circumferential side of the center hole; Each of the second hole groups comprises two second flow channels which pass through the iron core structure in the axial direction of the iron core structure, each of the third hole groups comprises two third flow channels which pass through the iron core structure in the axial direction of the iron core structure, and the fluid flow direction of the second flow channels is opposite to the fluid flow direction of the third flow channels; Each of the second flow channels and each of the third flow channels are in communication with the first flow channels.

3. The motor rotor of claim 2, wherein, The motor rotor further comprises two magnetic separation plates, the two magnetic separation plates are oppositely arranged at the two ends of the iron core structure in the axial direction and abut against the iron core structure, at least one first communication groove and a plurality of second communication grooves are formed on the end surfaces of the two magnetic separation plates facing each other, the first communication groove is located in the middle of the magnetic separation plate and is in communication with the first flow channels, part of the plurality of second communication grooves is in communication with the second flow channels, and the remaining part is in communication with the third flow channels; The two magnetic separation plates comprise a first magnetic separation plate and a second magnetic separation plate, in the first magnetic separation plate, the plurality of second communication grooves in communication with the second flow channels and the first communication groove are provided with a communication groove channel, and the plurality of second communication grooves in communication with the third flow channels are provided in a through manner, in the second magnetic separation plate, the plurality of second communication grooves in communication with the third flow channels and the first communication groove are provided with a communication groove channel, and the plurality of second communication grooves in communication with the second flow channels are provided in a through manner.

4. The motor rotor of claim 3, wherein Each of the second communication grooves is in communication with two second flow channels in the second hole group or two third flow channels in the third hole group.

5. The motor rotor of claim 3, wherein The size of the second communication groove is adapted to the size of the corresponding second flow channel or third flow channel.

6. The motor rotor of claim 3, wherein The cross-sectional area of the second communication groove provided in a through manner is arranged to decrease along the fluid flow direction.

7. The motor rotor of claim 2, wherein The rotating shaft has an inlet flow channel which extends in the axial direction of the rotating shaft, a plurality of radial branch holes are provided on the circumferential side of the rotating shaft, and each of the radial branch holes is in communication with the first flow channels and the inlet flow channel.

8. The motor rotor of claim 7, wherein, The rotating shaft is provided with a front bearing inclined oil hole and a rear bearing inclined oil hole at the positions of the two ends in the axial direction, one end of the front bearing inclined oil hole is in communication with the inlet flow channel, and the other end is used to correspond to the front bearing of the motor, one end of the rear bearing inclined oil hole is in communication with the inlet flow channel, and the other end is used to correspond to the rear bearing of the motor.

9. The motor rotor of claim 2, wherein The iron core structure comprises: an iron core, a plurality of magnetic steel holes are formed in the iron core, and the center hole is provided in the middle of the iron core; and A plurality of magnetic steels are inserted into the plurality of magnetic steel holes, and each of the magnetic steels and the hole wall of the magnetic steel hole jointly define the second flow channel or the third flow channel.

10. The motor rotor of claim 9, wherein, Each of the magnetic steels comprises a plurality of magnetic steel segments arranged in a staggered manner along the axial direction of the iron core structure.

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