Rotor punching sheet, motor rotor, driving motor and automobile

Abstract

The invention belongs to the technical field of motors, and particularly relates to a rotor punching sheet, a motor rotor, a driving motor and an automobile, the rotor punching sheet comprises a central shaft hole, a plurality of unit magnetic poles and first lightening holes, the plurality of unit magnetic poles are arranged around the central shaft hole at intervals, and each unit magnetic pole comprises at least one magnetic steel groove group. The magnetic steel groove group comprises magnetic steel grooves, the first lightening hole is arranged in an area between the adjacent magnetic steel grooves of the unit magnetic pole adjacent to the first lightening hole and the central shaft hole, the first lightening hole comprises a first side wall and a second side wall, a V-shaped included angle is formed between the first side wall and the second side wall, and an opening of the included angle points to the central shaft hole. By reducing the weight of the rotor punching sheet, the centrifugal force borne by the rotor punching sheet can be reduced, and the limitation of the structural strength of the rotor punching sheet on the increase of the maximum rotating speed of the driving motor is reduced.

Description

Technical Field

[0001] This application belongs to the technical field of motors, and particularly relates to a rotor punching sheet, a motor rotor, a drive motor, and an automobile. Background Art

[0002] With the development of new energy vehicles, the requirements for drive motors in new energy vehicles are getting higher and higher. In order to improve the power and driving range of new energy vehicles, the maximum rotational speed of drive motors is designed to be higher and higher. When an electric vehicle needs to accelerate or climb a slope, the motor can quickly output greater power and torque, providing better acceleration and power performance.

[0003] The drive motors of new energy vehicles mainly adopt permanent magnet synchronous motors. The arrangement of permanent magnets in permanent magnet synchronous motors is divided into two types: embedded type and surface-mounted type. However, to meet the high rotational speed requirements, drive motors usually adopt an embedded rotor structure. The embedded rotor structure is to open magnet slots on the punching sheet, place the permanent magnets inside, and use magnetic steel glue to fill the gaps for fixation.

[0004] The motor rotor rotates at a high speed, and the rotor punching sheet bears the centrifugal force of the magnetic steel and itself. Limited by the structural strength of the rotor punching sheet, it is difficult to further increase the maximum rotational speed of the drive motor. To reduce the limitation of the structural strength of the rotor punching sheet on the increase of the maximum rotational speed of the drive motor, some rotor punching sheets are provided with weight reduction holes, but the weight reduction holes reduce the structural strength of the rotor punching sheet. In addition, the weight reduction holes will also block the magnetic lines of force, resulting in a decrease in the peak torque output by the drive motor. Summary of the Invention

[0005] The purpose of this application is to provide a rotor punching sheet, a motor rotor, a drive motor, and an automobile, which can form weight reduction holes with larger sizes at least under the condition of ensuring the structural strength of the rotor punching sheet.

[0006] To achieve the above purpose, this application provides a rotor punching sheet, which includes a central shaft hole, unit magnetic poles, and a first weight reduction hole. A plurality of the unit magnetic poles are arranged at intervals around the central shaft hole. The unit magnetic pole includes at least one magnetic steel slot group, and the magnetic steel slot group includes magnetic steel slots. The first weight reduction hole is arranged in the area between the adjacent magnetic steel slots of the adjacent unit magnetic poles and the central shaft hole. The first weight reduction hole includes a first side wall and a second side wall. The included angle between the first side wall and the second side wall is a V-shaped angle, and the opening of the angle points to the central shaft hole. The included angle between the two magnetic steel slots belonging to two adjacent unit magnetic poles on both sides of the first weight reduction hole is a V-shaped angle, and the opening of the angle points to the central shaft hole.

[0007] Optionally, the included angle range between the first side wall, the second side wall and the adjacent magnetic steel slot is 0-20°.

[0008] Optionally, the first weight-reducing hole further includes a third side wall. The first side wall, the second side wall, and the third side wall are sequentially connected end to end. The first side wall and the second side wall are connected by an arc, the second side wall and the third side wall are connected by an arc, and the third side wall and the first side wall are connected by an arc.

[0009] Optionally, the distance between the third side wall and the central axis hole is 6 mm to 10 mm.

[0010] Optionally, the at least one magnet groove group includes a first magnet groove group. The first magnet groove group includes two magnet grooves. The two magnet grooves of the first magnet groove group are a first magnet groove and a second magnet groove. The first magnet groove and the second magnet groove are arranged at intervals and are radially symmetric with respect to the rotor punching sheet. The first magnet groove and the second magnet groove form a V-shaped angle, and the opening of the angle faces away from the central axis hole.

[0011] Optionally, the at least one magnet groove group further includes a second magnet groove group. The second magnet groove group is located on the side of the first magnet groove group away from the central axis hole;

[0012] The second magnet groove group includes two magnet grooves. The two magnet grooves of the second magnet groove group are a third magnet groove and a fourth magnet groove. The third magnet groove and the fourth magnet groove are arranged at intervals and are radially symmetric with respect to the rotor punching sheet. The third magnet groove and the fourth magnet groove form a V-shaped angle, and the opening of the angle faces away from the central axis hole.

[0013] Optionally, the magnet groove includes a receiving area for installing a magnet. The angle between the first magnet groove and the second magnet groove is 95° ± 20°. The length of the receiving area in the first magnet groove and the second magnet groove is 20 mm ± 5 mm. The width of the receiving area in the first magnet groove and the second magnet groove is 5 mm ± 2 mm;

[0014] The angle between the third magnet groove and the fourth magnet groove is 140° ± 20°. The length of the receiving area in the third magnet groove and the fourth magnet groove is 10 mm ± 3 mm. The width of the receiving area in the third magnet groove and the fourth magnet groove is 3 mm ± 1.5 mm.

[0015] Optionally, the distance between the first side wall and the adjacent magnet groove is 6 mm to 10 mm, and the distance between the second side wall and the adjacent magnet groove is 6 mm to 10 mm.

[0016] Optionally, a first magnetic isolation bridge is provided between one end of the first magnet groove close to the central shaft hole and one end of the second magnet groove close to the central shaft hole, a second magnetic isolation bridge is provided between one end of the third magnet groove close to the central shaft hole and one end of the fourth magnet groove close to the central shaft hole, and a second weight-reducing hole is provided between the first magnetic isolation bridge and the second magnetic isolation bridge.

[0017] Optionally, the magnet groove includes a communication area, a placement area, and a groove area that are connected in sequence. The communication area is communicated with the outer cylindrical surface of the rotor punching sheet. The placement area is used for installing a magnet, and the groove area is used for the circulation of coolant.

[0018] Optionally, the distance from the communication area to the groove area is the length of the placement area. The width of the connection between the communication area and the placement area is less than the width of the placement area, and the width of the connection between the groove area and the placement area is less than the width of the placement area.

[0019] Optionally, the distance from the communication area to the groove area is the length of the placement area, and the orthographic projection of the placement area in its width direction is located within the orthographic projection of the groove area in the width direction of the placement area.

[0020] This application also provides a motor rotor, including:

[0021] A rotating shaft;

[0022] The rotor punching sheet, which is sleeved on the rotating shaft through the central shaft hole and is radially locked. A plurality of the rotor punching sheets are stacked to form a rotor core;

[0023] Magnets, arranged in the magnet grooves.

[0024] Optionally, at least part of the rotor punching sheets are arranged in a staggered manner to form an inclined pole structure. The magnet groove includes a connected placement area and a groove area. The groove area is located on the side of the placement area close to the central shaft hole. The magnets are arranged in the placement area, and the groove areas of adjacent rotor punching sheets are connected. The groove area is used for the circulation of coolant.

[0025] Optionally, the motor rotor further includes a protective sleeve. The rotor punching sheet is arranged in the protective sleeve, and the material of the protective sleeve includes carbon fiber.

[0026] This application also provides a driving motor, including:

[0027] A stator;

[0028] The motor rotor, which is sleeved in the stator.

[0029] This application also provides a vehicle, including:

[0030] the driving motor;

[0031] a wheel, connected to the driving motor through a transmission mechanism.

[0032] The rotor punching sheet, motor rotor, driving motor and vehicle disclosed in this application have the following beneficial effects:

[0033] In this application, the rotor punching sheet includes a central shaft hole, unit magnetic poles and first weight-reducing holes. A plurality of unit magnetic poles are arranged at intervals around the central shaft hole. Each unit magnetic pole includes at least one permanent magnet slot group, and each permanent magnet slot group includes a permanent magnet slot. The first weight-reducing hole is arranged in the area between the adjacent permanent magnet slots of the adjacent unit magnetic poles and the central shaft hole. The first weight-reducing hole includes a first side wall and a second side wall. The angle between the first side wall and the second side wall is a V-shaped angle, and the opening of the angle points to the central shaft hole. The angles between the two permanent magnet slots belonging to two unit magnetic poles on both sides of the first weight-reducing hole are V-shaped angles, and the openings of the angles point to the central shaft hole. The shape and position of the first weight-reducing hole are set in accordance with the shape and position of the permanent magnet slots. Under the condition of ensuring the structural strength of the rotor punching sheet, a first weight-reducing hole with a larger size can be formed, which is beneficial to improving the maximum speed of the driving motor. In addition, the first side wall and the second side wall of the weight-reducing hole also play a certain guiding role for the magnetic force lines, so as to minimize the blockage of the magnetic force lines by the first weight-reducing hole as much as possible, which is beneficial to alleviating the decrease in peak torque caused by the blockage of the magnetic force lines.

[0034] Other features and advantages of this application will become apparent through the following detailed description, or will be learned in part through the practice of this application.

[0035] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The drawings here are incorporated into the description and form a part of this description, showing embodiments consistent with this application, and are used together with the description to explain the principles of this application. Obviously, the drawings in the following description are only some embodiments of this application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0037] Figure 1 is a schematic structural diagram of the motor rotor in an embodiment of this application.

[0038] Figure 2 is a schematic structural diagram of the rotor punching sheet in an embodiment of this application.

[0039] Figure 3 is a schematic structural diagram of the unit magnetic pole in an embodiment of this application.

[0040] Description of the reference numerals:

[0041] 100, Rotating shaft;

[0042] 200, Rotor punching sheet; 210, Magnet slot group; 210a, First magnet slot; 210b, Second magnet slot; 210c, Third magnet slot; 210d, Fourth magnet slot; 211, Connecting area; 212, Accommodating area; 213, Groove area; 220, Second weight reduction hole; 230, First weight reduction hole; 231, First side wall; 232, Second side wall; 233, Third side wall; 240, Central axis hole;

[0043] 300, Magnet; 400, Protective sleeve. Detailed implementation manners

[0044] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this application will be more complete and comprehensive, and will fully convey the concept of the example embodiments to those skilled in the art.

[0045] In addition, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of the embodiments of this application. However, those skilled in the art will realize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, devices, steps, etc. can be adopted. In other cases, well-known methods, devices, implementations, or operations are not shown or described in detail to avoid obscuring aspects of this application.

[0046] The present application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted here that the technical features involved in the various embodiments of the present application described below can be combined with each other as long as they do not conflict with each other. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present application and should not be construed as limiting the present application.

[0047] See Figures 1 to 3As shown in the figure, in this embodiment, the rotor punching sheet 200 includes a central shaft hole 240, unit magnetic poles, and a first weight-reducing hole 230. A plurality of unit magnetic poles are arranged at intervals around the central shaft hole 240. The unit magnetic poles include at least one permanent magnet groove group 220, and the permanent magnet groove group 220 includes permanent magnet grooves for installing permanent magnets 300. The first weight-reducing hole 230 is disposed in the area between the adjacent permanent magnet grooves of the adjacent unit magnetic poles and the central shaft hole. The first weight-reducing hole 230 includes a first side wall 231 and a second side wall 232. The included angle between the first side wall 231 and the second side wall 232 is a V-shaped angle, and the opening of the angle points to the central shaft hole 240. The included angle between the two permanent magnet grooves belonging to two unit magnetic poles on both sides of the first weight-reducing hole 230 is a V-shaped angle, and the opening of the angle points to the central shaft hole 240.

[0048] The rotor punching sheet 200 can be formed by stamping silicon steel sheets, but it is not limited thereto. The material of the rotor punching sheet 200 is not limited to silicon steel sheets, and the manufacturing process of the rotor punching sheet 200 is not limited to stamping either, which can be determined according to specific circumstances.

[0049] Opening the first weight-reducing hole 230 on the rotor punching sheet 200 can reduce the weight of the rotor punching sheet 200. Theoretically, the larger the size of the first weight-reducing hole 230 opened, the smaller the centrifugal force borne by the rotor punching sheet 200, and the less restricted the maximum speed increase of the drive motor by the structural strength of the rotor punching sheet 200. However, opening the first weight-reducing hole 230 on the rotor punching sheet 200 will, on the one hand, reduce the structural strength of the rotor punching sheet 200, and on the other hand, block the magnetic lines of force (i.e., the magnetic circuit). The more the magnetic lines of force are blocked, the more the torque of the drive motor will decrease, and the performance of the motor will be limited.

[0050] In this embodiment, the rotor punching sheet 200 includes a central shaft hole 240, unit magnetic poles, and a first weight-reducing hole 230. A plurality of unit magnetic poles are arranged at intervals around the central shaft hole 240. The unit magnetic poles include at least one permanent magnet groove group 220, and the permanent magnet groove group 220 includes permanent magnet grooves. The first weight-reducing hole 230 is disposed in the area between the adjacent permanent magnet grooves of the adjacent unit magnetic poles and the central shaft hole. The first weight-reducing hole 230 includes a first side wall 231 and a second side wall 232. The included angle between the first side wall 231 and the second side wall 232 is a V-shaped angle, and the opening of the angle points to the central shaft hole 240. The included angle between the two permanent magnet grooves belonging to two unit magnetic poles on both sides of the first weight-reducing hole 230 is a V-shaped angle, and the opening of the angle points to the central shaft hole 240. The first weight-reducing hole 230 is disposed in the area between the adjacent permanent magnet grooves of the adjacent unit magnetic poles and the central shaft hole, and the shape and position of the first weight-reducing hole 230 are set to conform to the shape and position of the permanent magnet grooves. A larger-size first weight-reducing hole 230 can be formed in the area between the unit magnetic poles and the central shaft hole under the condition of ensuring the structural strength of the rotor punching sheet 200, which is beneficial to increasing the maximum speed of the drive motor.

[0051] In addition, the magnetic field lines flow from the positive magnetic steel 300 of one unit magnetic pole to the negative magnetic steel 300 of the adjacent unit magnetic pole. In the area where the unit magnetic pole is located, the magnetic field lines are densely distributed, and the farther away from the unit magnetic pole, the sparser the magnetic field lines. The shape and position of the first weight-reducing hole 230 are set in accordance with the shape and position of the magnetic steel groove. On the one hand, it can minimize the blockage of the magnetic field lines as much as possible. On the other hand, the first side wall 231 and the second side wall 232 of the first weight-reducing hole 230 can also play a certain guiding role in the magnetic field lines. The magnetic field lines are easily guided by the two side walls and flow from the positive pole of one unit magnetic pole to the negative pole of the adjacent unit magnetic pole, thereby minimizing the blockage of the magnetic field lines by the first weight-reducing hole 230 and helping to alleviate the peak torque drop caused by the blockage of the magnetic field lines.

[0052] See Figures 1 to 3 As shown, the included angle range between the first side wall 231 and the adjacent magnetic steel groove is 0 to 20°, and the included angle range between the second side wall 232 and the adjacent magnetic steel groove is 0 to 20°.

[0053] Setting the first side wall 231 and the second side wall 232 to have a small included angle range (i.e., approximately parallel) with the adjacent magnetic steel groove, compared with the scheme of setting the first side wall 231 and the second side wall 232 to have a large included angle with the adjacent magnetic steel groove, on the one hand, it is beneficial to form a first weight-reducing hole 230 with a larger size in the area between the unit magnetic pole and the central axis hole. On the other hand, it can avoid stress concentration in the area between the first side wall 231 and the second side wall 232 and their adjacent magnetic steel grooves, which affects the structural strength of the rotor punching sheet 200.

[0054] See Figures 1 to 3 As shown, the first weight-reducing hole 230 further includes a third side wall 233, and the first side wall 231, the second side wall 232, and the third side wall 233 are connected end to end in sequence. The first side wall 231 and the second side wall 232 are connected by an arc, the second side wall 232 and the third side wall 233 are connected by an arc, and the third side wall 233 and the first side wall 231 are connected by an arc.

[0055] The first side wall 231, the second side wall 232, and the third side wall 233 are all connected by arcs pairwise, which can avoid stress concentration in the connection areas between the first side wall 231, the second side wall 232, and the third side wall 233 pairwise, and improve the fatigue strength of the rotor punching sheet 200. At the same time, the first side wall 231, the second side wall 232, and the third side wall 233 are all connected by arcs pairwise, which can minimize the blockage of the magnetic field lines as much as possible. The magnetic field lines are easily guided by the arc angles and flow from the positive pole of one unit magnetic pole to the negative pole of the adjacent unit magnetic pole.

[0056] See Figures 1 to 3As shown, the distance between the first side wall 231 and the adjacent magnet slot is greater than or equal to 6 mm. Preferably, the distance between the first side wall 231 and the adjacent magnet slot is 6 mm to 10 mm. The distance between the second side wall 232 and the adjacent magnet slot is greater than or equal to 6 mm. Preferably, the distance between the second side wall 232 and the adjacent magnet slot is 6 mm to 10 mm. The distance between the third side wall 233 and the central axis hole 240 is greater than or equal to 6 mm. Preferably, the distance between the third side wall 233 and the central axis hole 240 is 6 mm to 10 mm.

[0057] The distances between the first side wall 231 and the second side wall 232 and their respective adjacent magnet slots are greater than or equal to 6 mm, and the distance between the third side wall 233 and the central axis hole 240 is greater than or equal to 6 mm. While reducing the weight of the rotor punching sheet 200, on the one hand, it can reduce the blockage of the magnetic lines of force, and on the other hand, it can avoid the distance between the first weight reduction hole 230 and the central axis hole 240 and the magnet slot being too small, resulting in insufficient strength of the rotor punching sheet 200.

[0058] See Figures 1 to 3 As shown, at least one magnet slot group 210 includes a first magnet slot group. The first magnet slot group includes two magnet slots. The two magnet slots of the first magnet slot group are the first magnet slot 210a and the second magnet slot 210b. The first magnet slot 210a and the second magnet slot 210b are arranged at intervals and are radially symmetric with respect to the rotor punching sheet 200. The first magnet slot 210a and the second magnet slot 210b form a V-shaped angle, and the opening of the angle faces away from the central axis hole 240 of the rotor punching sheet 200.

[0059] The amount of the magnet 300 is positively correlated with the output torque of the drive motor. The more the amount of the magnet 300, the greater the torque that the drive motor can output. However, since the area on the rotor punching sheet 200 where the magnet 300 can be arranged is limited, and the more the amount of the magnet 300, the higher the material cost of the drive motor. The layout of the first magnet slot 210a and the second magnet slot 210b in a V-shaped angle can reduce the amount of the magnet 300 and reduce the manufacturing cost of the drive motor without affecting the output torque.

[0060] See Figures 1 to 3 As shown, at least one magnet slot group 210 further includes a second magnet slot group. The second magnet slot group is located on the side of the first magnet slot group away from the central axis hole 240. The second magnet slot group includes two magnet slots. The two magnet slots of the second magnet slot group are the third magnet slot 210c and the fourth magnet slot 210d. The third magnet slot 210c and the fourth magnet slot 210d are arranged at intervals and are radially symmetric with respect to the rotor punching sheet 200. The third magnet slot 210c and the fourth magnet slot 210d form a V-shaped angle, and the opening of the angle faces away from the central axis hole 240 of the rotor punching sheet 200.

[0061] The third magnet slot 210c and the fourth magnet slot 210d are arranged at a V-shaped angle, which can reduce the amount of magnets 300 used and the manufacturing cost of the drive motor without affecting the output torque.

[0062] See Figures 1 to 3 As shown, the included angle between the first magnet slot 210a and the second magnet slot 210b is 95° ± 20°, such as 75°, 95° or 115°, etc. The magnet slot includes a receiving area 212 for installing the magnet 300. The length of the receiving area 212 in the first magnet slot 210a and the second magnet slot 210b is 20mm ± 5mm, such as 15mm, 20mm or 25mm, etc. The width of the receiving area 212 in the first magnet slot 210a and the second magnet slot 210b is 5mm ± 2mm, such as 3mm, 5mm or 7mm, etc.

[0063] The included angle between the third magnet slot 210c and the fourth magnet slot 210d is 140° ± 20°, such as 120°, 140° or 160°, etc. The length of the receiving area 212 in the third magnet slot 210c and the fourth magnet slot 210d is 10mm ± 3mm, such as 7mm, 10mm or 13mm, etc. The width of the receiving area 212 in the third magnet slot 210c and the fourth magnet slot 210d is 3mm ± 1.5mm, such as 1.5mm, 3mm or 4.5mm, etc.

[0064] The size of the second magnet slot group is smaller than that of the first magnet slot group. The second magnet slot group is arranged in the area between the first magnet slot group and the outer cylindrical surface of the rotor punching sheet 200, improving the space utilization rate on the rotor punching sheet 200. On the premise of meeting the torque requirement, the magnet slot structure is reasonably arranged, that is, the two groups of V-shaped magnet slot arrangement structures, which can reduce the amount of magnets 300 used and the manufacturing cost of the drive motor without affecting the output torque. At the same time, optimizing the size and position design of the magnet slot can reduce the blockage of the magnetic force line by the setting of the first weight reduction hole 230 and reduce the influence of the setting of the first weight reduction hole 230 on the torque of the drive motor.

[0065] See Figures 1 to 3 As shown, a first magnetic isolation bridge is provided between one end of the first magnet slot 210a close to the central shaft hole 240 and one end of the second magnet slot 210b close to the central shaft hole 240, and a second magnetic isolation bridge is provided between one end of the third magnet slot 210c close to the central shaft hole 240 and one end of the fourth magnet slot 210d close to the central shaft hole 240. The width of the first magnetic isolation bridge is 2mm ± 1mm, and the width of the second magnetic isolation bridge is 1mm ± 0.5mm. The extending directions of the first magnetic isolation bridge and the second magnetic isolation bridge are consistent with the resultant direction of the centrifugal force of the rotor punching sheet.

[0066] The principle of the magnetic isolation bridge is to limit the magnetic leakage by making the magnetic flux in the magnetic isolation bridge part reach saturation. Setting the magnetic isolation bridge can prevent the magnetic leakage coefficient of the permanent magnet 300 from being too large, resulting in too low utilization rate of the permanent magnet 300. From the perspective of preventing magnetic leakage, the smaller the width of the magnetic isolation bridge, the better the magnetic isolation effect. However, if the width of the magnetic isolation bridge is too small, stress concentration is likely to occur in the magnetic isolation bridge area of the rotor punching sheet 200, reducing the structural strength of the rotor punching sheet 200. In this application, the width of the first magnetic isolation bridge is 2mm ± 1mm, and the width dimension of the second magnetic isolation bridge is 1mm ± 0.5mm, which can not only avoid the insufficient structural strength of the rotor punching sheet 200 due to too small width of the magnetic isolation bridge, but also play a role in limiting magnetic leakage. In addition, the resultant direction of the centrifugal force of the rotor punching sheet 200 is outward. The extending directions of the first magnetic isolation bridge and the second magnetic isolation bridge are set to be consistent with the resultant direction of the centrifugal force of the rotor punching sheet 200, so that the magnetic isolation bridge area can bear the centrifugal force of the permanent magnet and itself.

[0067] See Figures 1 to 3 As shown, a second weight reduction hole 220 is provided between the first magnetic isolation bridge and the second magnetic isolation bridge. The distance from the second weight reduction hole 220 to the first magnetic isolation bridge is equal to or approximately equal to the distance from the second weight reduction hole 220 to the second magnetic isolation bridge. For example, the difference between the distance from the second weight reduction hole 220 to the first permanent magnet groove group and the distance from the second weight reduction hole 220 to the second permanent magnet groove group is less than 1.5mm.

[0068] By providing the second weight reduction hole 220 between the first magnetic isolation bridge and the second magnetic isolation bridge, the weight of the area between the first magnetic isolation bridge and the second magnetic isolation bridge is reduced, which can reduce the centrifugal force generated at the position of the second weight reduction hole borne by the first magnetic isolation bridge, reduce the stress of the first magnetic isolation bridge, and avoid deformation and fracture caused by excessive stress near the first magnetic isolation bridge.

[0069] Exemplarily, see Figures 1 to 3 As shown, the permanent magnet groove includes a communication area 211, a placement area 212 and a groove area 213 that are connected in sequence. The communication area 211 is connected to the outer cylindrical surface of the rotor punching sheet 200. The placement area 212 is used to install the permanent magnet 300, and the groove area 213 is used for the circulation of the coolant. The contour line of the permanent magnet groove adopts an arc transition to avoid stress concentration in the permanent magnet groove area.

[0070] The permanent magnet 300 is arranged in the placement area 212. Specifically, the permanent magnet groove is connected to the outer cylindrical surface of the rotor punching sheet 200 through the communication area 211 on one side of the placement area 212. The groove area 213 is arranged on the other side of the placement area 212 of the permanent magnet groove, and the groove area 213 is used for the circulation of the coolant, so as to directly cool the permanent magnet 300. With this design, the temperature of the permanent magnet 300 can be effectively controlled, and the high-temperature demagnetization of the permanent magnet 300, which affects the performance of the drive motor, can be avoided.

[0071] The magnetic steel groove communicates with the outer cylindrical surface of the rotor punching sheet 200 to form a communication area 211, that is, the magnetic steel groove is interrupted along the outer circle of the rotor punching sheet 200. With this design, the magnetic force lines can be blocked from passing through the communication area 211, reducing the magnetic leakage risk in the communication area between the magnetic steel groove and the outer cylindrical surface of the rotor punching sheet 200, increasing the magnetic force lines passing between the motor rotor and the motor stator, increasing the driving motor torque, and improving the performance of the driving motor.

[0072] See Figures 1 to 3 As shown, the distance from the communication area 211 to the groove area 213 is the length of the accommodating area 212. The length of the accommodating area 212 can be greater than or equal to the length of the magnetic steel 300, and the width of the accommodating area 212 is greater than or equal to the width of the magnetic steel 300. The orthographic projection of the accommodating area 212 in its width direction is located within the orthographic projection of the groove area 213 in the width direction of the accommodating area 212, that is, the width of at least part of the groove area 213 is greater than the width of the accommodating area 212.

[0073] The width of at least part of the groove area 213 is greater than the width of the accommodating area 212, so the groove area 213 is less likely to be blocked, and thus the temperature of the magnetic steel 300 can be effectively controlled, avoiding the demagnetization of the magnetic steel 300 at high temperature and affecting the performance of the driving motor.

[0074] See Figures 1 to 3 As shown, the distance from the communication area 211 to the groove area 213 is the length of the accommodating area 212. The width of the connection between the communication area 211 and the accommodating area 212 is less than the width of the magnetic steel 300, that is, a shoulder structure is formed at the connection between the communication area 211 and the accommodating area 212; the width of the connection between the groove area 213 and the accommodating area 212 is less than the width of the magnetic steel 300, that is, a shoulder structure is formed at the connection between the groove area 213 and the accommodating area 212. The shoulder structure can block the magnetic steel 300 and limit the movement of the magnetic steel 300 in the length direction of the accommodating area 212.

[0075] The width of the connection between the groove area 213 and the accommodating area 212 is less than the width of the magnetic steel 300, which can prevent the magnetic steel 300 from entering the groove area 213 and affecting the circulation of the coolant. The width of the connection between the communication area 211 and the accommodating area 212 is less than the width of the magnetic steel 300, which can prevent the magnetic steel 300 from detaching from the accommodating area 212 under the action of centrifugal force.

[0076] The present application also provides a motor rotor, which includes a rotating shaft 100, a rotor punching sheet 200, and a permanent magnet 300. The rotor punching sheet 200 is sleeved on the rotating shaft 100 through a central shaft hole 240 and is locked radially. For example, the rotor punching sheet 200 and the rotating shaft 100 are connected by a concave-convex key, and there is no relative rotation between the rotating shaft 100 and the rotor punching sheet 200. The rotating shaft 100 can drive the rotor punching sheet 200 to rotate. A plurality of rotor punching sheets 200 are stacked to form a rotor core. The rotor punching sheet 200 includes a plurality of unit magnetic poles arranged at intervals along its circumference. The unit magnetic pole includes at least one permanent magnet groove group 210. The permanent magnet groove group 210 includes a permanent magnet groove. The permanent magnet 300 is arranged in the permanent magnet groove, and a gap is formed between the permanent magnet 300 and the outer cylinder of the rotor punching sheet 200. The permanent magnet 300 can be connected to the rotor punching sheet 200 through a permanent magnet adhesive or an injection plastic. The motor rotor can be used for the drive motor of an automobile.

[0077] The motor rotor includes a rotor punching sheet 200. The rotor punching sheet 200 includes a central shaft hole 240, a unit magnetic pole, and a first weight-reducing hole 230. A plurality of unit magnetic poles are arranged at intervals around the central shaft hole 240. The unit magnetic pole includes at least one permanent magnet groove group 220. The permanent magnet groove group 220 includes a permanent magnet groove. The first weight-reducing hole 230 is arranged in the area between the adjacent permanent magnet grooves of the adjacent unit magnetic poles and the central shaft hole. The first weight-reducing hole 230 includes a first side wall 231 and a second side wall 232. An included angle between the first side wall 231 and the second side wall 232 is a V-shaped angle, and the opening of the angle points to the central shaft hole 240. By reducing the weight of the rotor punching sheet 200, the centrifugal force borne by the rotor punching sheet 200 can be reduced, and the limitation of the structural strength of the rotor punching sheet 200 on the maximum speed increase of the drive motor can be reduced.

[0078] In some embodiments, at least part of the rotor punching sheets 200 are arranged in a staggered manner to form an inclined pole structure. For example, a plurality of rotor punching sheets 200 can be divided into three segments. The second segment is displaced by a certain angle clockwise or counterclockwise compared with the first segment, and the third segment is displaced by a certain angle in the same direction compared with the second segment to form an inclined pole structure. The displacement angle between the first rotor punching sheet 200 and the second rotor punching sheet 200, and the displacement angle between the second rotor punching sheet 200 and the third rotor punching sheet 200 can be set as required.

[0079] At least part of the rotor punching sheets 200 are arranged in a staggered manner to form an inclined pole structure, which can suppress electromagnetic noise and improve the NVH (Noise, Vibration, Harshness) characteristics of the motor.

[0080] At least part of the rotor punching sheets 200 are arranged in a staggered manner to form an inclined pole structure, and there will be an overlap of the inclined poles. For two adjacent rotor punching sheets 200 arranged in a staggered manner: one rotor punching sheet 200 will block the groove area 213 of the other rotor punching sheet 200, resulting in a reduction in the flow area of the groove area 213, which will affect the coolant flow in the groove area 213.

[0081] In this embodiment, the orthographic projection of the accommodation area 212 in its width direction is located within the orthographic projection of the groove area 213 in the width direction of the accommodation area 212, that is, the width of at least part of the groove area 213 is greater than the width of the accommodation area 212. With such a design, even if there is a certain misalignment between two adjacent rotor laminations 200, due to the enlarged groove area 213, the groove areas 213 of the adjacent rotor laminations 200 are still connected, thereby reducing or eliminating the reduction in the flow area of the groove area 213 caused by the misalignment of the rotor laminations 200, reducing the flow resistance of the coolant, and avoiding the problem of the coolant channel being blocked.

[0082] See Figure 1 As shown, the motor rotor further includes a protective sleeve 400. The rotor lamination 200 is disposed within the protective sleeve 400, and the material of the protective sleeve 400 includes carbon fiber.

[0083] The protective sleeve 400 wraps the rotor lamination 200 to counteract the centrifugal force generated by the rotation of the rotor lamination 200, which can improve the structural strength of the motor rotor.

[0084] In addition, in this embodiment, the rotor lamination 200 adopts an integrated design. Compared with the scheme in which the rotor lamination 200 is split into two parts, the product has good consistency and is easy to assemble. The rotor lamination 200 adopts an integrated design with high structural strength, the thickness of the protective sleeve 400 can be reduced, the manufacturing cost of the motor rotor is reduced. The thickness of the protective sleeve 400 can be reduced, the occupied air gap can be reduced, and the rotor output torque is increased.

[0085] This application also provides a drive motor, which at least includes a stator and the motor rotor disclosed above. The motor rotor is disposed within the stator.

[0086] The drive motor includes a motor rotor, and the motor rotor includes: a rotating shaft 100, a rotor lamination 200, and a permanent magnet 300. The rotor lamination 200 is sleeved on the rotating shaft 100 and radially locked. The rotor lamination 200 includes a plurality of unit magnetic poles arranged at intervals along its circumferential direction. The unit magnetic pole includes at least one permanent magnet slot group 210, and the permanent magnet slot group 210 includes permanent magnet slots. The permanent magnet 300 is disposed within the permanent magnet slots. By reducing the weight of the rotor lamination 200, the centrifugal force borne by the rotor lamination 200 can be reduced, and the limitation of the structural strength of the rotor lamination 200 on the maximum speed increase of the drive motor can be reduced, thereby improving the performance of the drive motor, that is, the drive motor has a small moment of inertia, a fast dynamic response, and good peak speed performance.

[0087] This application also provides a vehicle, which includes a drive motor and wheels. The wheels are connected to the drive motor through a transmission mechanism. The vehicle includes a hybrid electric vehicle and a pure electric vehicle.

[0088] The driving motor has a small moment of inertia, fast dynamic response, and good peak rotational speed performance. The driving motor is used in hybrid electric vehicles and pure electric vehicles, which can improve the vehicle power performance of the automobiles.

[0089] The terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of this application, "a plurality of" means two or more unless otherwise specifically defined.

[0090] In this application, unless otherwise clearly specified and defined, terms such as "assembly", "connection", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0091] In the description of this specification, the descriptions referring to terms such as "some embodiments", "exemplarily", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of this application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0092] Although the embodiments of this application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as a limitation to this application. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of this application. Therefore, any changes or modifications made in accordance with the claims and the description of this application shall fall within the scope covered by the patent of this application.

Claims

1. A rotor punching sheet, characterized in that, The rotor punching sheet includes a central shaft hole, unit magnetic poles, and first weight-reducing holes. A plurality of the unit magnetic poles are arranged at intervals around the central shaft hole. The unit magnetic poles include at least one magnetic steel groove group, and the magnetic steel groove group includes magnetic steel grooves. The first weight-reducing holes are arranged in the area between the adjacent magnetic steel grooves of the adjacent unit magnetic poles and the central shaft hole. The first weight-reducing holes include a first side wall and a second side wall. The angle between the first side wall and the second side wall is a V-shaped angle, and the opening of the angle points to the central shaft hole. The angle between the two magnetic steel grooves belonging to two adjacent unit magnetic poles on both sides of the first weight-reducing hole is a V-shaped angle, and the opening of the angle points to the central shaft hole.

2. The rotor punching sheet according to claim 1, characterized in that, The angle between the first side wall and the adjacent magnetic steel groove ranges from 0° to 20°, and the angle between the second side wall and the adjacent magnetic steel groove ranges from 0° to 20°.

3. The rotor punching sheet according to claim 1, characterized in that, The first weight-reducing hole further includes a third side wall. The first side wall, the second side wall, and the third side wall are connected end to end in sequence. The first side wall and the second side wall are connected by an arc, the second side wall and the third side wall are connected by an arc, and the third side wall and the first side wall are connected by an arc.

4. The rotor punching sheet according to claim 3, characterized in that, The distance between the third side wall and the central shaft hole is 6 mm to 10 mm.

5. The rotor punching sheet according to claim 1, characterized in that, The at least one magnetic steel groove group includes a first magnetic steel groove group. The first magnetic steel groove group includes two magnetic steel grooves. The two magnetic steel grooves of the first magnetic steel groove group are a first magnetic steel groove and a second magnetic steel groove. The first magnetic steel groove and the second magnetic steel groove are arranged at intervals and are radially symmetric with respect to the rotor punching sheet. The first magnetic steel groove and the second magnetic steel groove form a V-shaped angle, and the opening of the angle faces away from the central shaft hole.

6. The rotor punching sheet according to claim 5, characterized in that, The at least one magnetic steel groove group further includes a second magnetic steel groove group. The second magnetic steel groove group is located on the side of the first magnetic steel groove group away from the central shaft hole. The second magnetic steel groove group includes two magnetic steel grooves. The two magnetic steel grooves of the second magnetic steel groove group are a third magnetic steel groove and a fourth magnetic steel groove. The third magnetic steel groove and the fourth magnetic steel groove are arranged at intervals and are radially symmetric with respect to the rotor punching sheet. The third magnetic steel groove and the fourth magnetic steel groove form a V-shaped angle, and the opening of the angle faces away from the central shaft hole.

7. The rotor punching sheet according to claim 6, characterized in that, The magnetic steel groove includes a placement area for installing a magnetic steel. The angle between the first magnetic steel groove and the second magnetic steel groove is 95° ± 20°. The length of the placement area in the first magnetic steel groove and the second magnetic steel groove is 20 mm ± 5 mm. The width of the placement area in the first magnetic steel groove and the second magnetic steel groove is 5 mm ± 2 mm. The angle between the third magnetic steel groove and the fourth magnetic steel groove is 140° ± 20°. The length of the placement area in the third magnetic steel groove and the fourth magnetic steel groove is 10 mm ± 3 mm. The width of the placement area in the third magnetic steel groove and the fourth magnetic steel groove is 3 mm ± 1.5 mm.

8. The rotor punching sheet according to claim 6, characterized in that, The distance between the first side wall and the adjacent magnetic steel groove is 6 mm to 10 mm, and the distance between the second side wall and the adjacent magnetic steel groove is 6 mm to 10 mm.

9. The rotor punching sheet according to claim 6, characterized in that, A first magnetic isolation bridge is provided between one end of the first magnetic steel groove close to the central shaft hole and one end of the second magnetic steel groove close to the central shaft hole. A second magnetic isolation bridge is provided between one end of the third magnetic steel groove close to the central shaft hole and one end of the fourth magnetic steel groove close to the central shaft hole. A second weight-reducing hole is provided between the first magnetic isolation bridge and the second magnetic isolation bridge.

10. The rotor punching sheet according to claim 6, characterized in that, The magnetic steel groove includes a communication area, a placement area, and a groove area that are connected in sequence. The communication area is connected to the outer cylindrical surface of the rotor punching sheet. The placement area is used for installing magnetic steel. The groove area is used for the circulation of coolant.

11. The rotor punching sheet according to claim 10, characterized in that, The distance from the communication area to the groove area is the length of the placement area. The width of the connection between the communication area and the placement area is smaller than the width of the placement area. The width of the connection between the groove area and the placement area is smaller than the width of the placement area.

12. The rotor punching sheet according to claim 10, characterized in that, The distance from the communication area to the groove area is the length of the placement area. The orthographic projection of the placement area in its width direction is located within the orthographic projection of the groove area in the width direction of the placement area.

13. A motor rotor, characterized in that, Comprising: A rotating shaft; The rotor punching sheet according to any one of claims 1 to 12, the rotor punching sheet is sleeved on the rotating shaft through the central shaft hole and is radially locked. A plurality of the rotor punching sheets are stacked to form a rotor core; Magnetic steel, arranged in the magnetic steel groove.

14. The motor rotor according to claim 13, characterized in that, At least part of the rotor punching sheets are arranged in a staggered manner to form an inclined pole structure. The magnetic steel groove includes a connected placement area and a groove area. The groove area is located on the side of the placement area close to the central shaft hole. The magnetic steel is arranged in the placement area. The groove areas of adjacent rotor punching sheets are connected. The groove area is used for the circulation of coolant.

15. The motor rotor according to claim 13, characterized in that, The motor rotor further includes a protective sleeve. The rotor punching sheet is arranged in the protective sleeve. The material of the protective sleeve includes carbon fiber.

16. A driving motor, characterized in that, Comprising: A stator; The motor rotor according to any one of claims 13 to 15, the motor rotor is sleeved in the stator.

17. A vehicle, characterized in that, Comprising: The drive motor according to claim 16; A wheel, connected to the drive motor through a transmission mechanism.

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