Rotor core and motor

Abstract

The utility model relates to the technical field of motors, and discloses a rotor core and a motor, and the rotor core comprises a rotor punching sheet and a plurality of first magnetic parts. The rotor punching sheet is provided with a plurality of first installation openings, and the plurality of first installation openings are arranged at intervals along the annular direction of the rotor punching sheet. The multiple first magnetic parts are installed in the multiple first installation openings respectively, the distance between every two adjacent first magnetic parts is larger than the effective magnetic isolation distance, and the effective magnetic isolation distance is the maximum distance ensuring that the magnetic leakage coefficient of the first magnetic parts meets the design requirement; wherein each first magnetic part is provided with two first cutting structures, the two first cutting structures are obtained by conducting corner cutting treatment on two corners, close to one side of the peripheral wall, of the first magnetic part, and a first gap is formed between each first cutting structure and the edge of the first mounting opening. According to the rotor core and the motor provided by the invention, the structural strength is high, the leakage flux of the first magnetic part on the leakage flux path is reduced, and the power density is improved.

Description

Technical Field

[0001] The present application relates to the technical field of motors, and in particular to a rotor core and a motor. Background Art

[0002] With the rapid development of electric vehicles, the speed and power density of vehicle drive motors are increasingly required, and high speeds will bring greater challenges to the motor structure. Taking the internal permanent magnet motor commonly used in electric vehicles as an example, there is usually a magnetic isolation bridge on the rotor core, which is used for strength support on the one hand and can reduce magnetic leakage on the other hand.

[0003] However, higher motor speeds will bring greater centrifugal force to the rotor, and stress concentration is prone to occur in the magnetic isolation bridge, which can lead to fatigue fracture. In order to reduce the risk of damage to the magnetic isolation bridge caused by higher speeds, a relatively thick magnetic isolation bridge can be set, but this will increase the risk of motor leakage and reduce the electromagnetic performance of the motor, such as torque and efficiency. Utility Model Content

[0004] In view of this, the present application provides a rotor core and a motor, which have high structural strength and reduce the leakage flux of the first magnetic part, thereby improving the power density.

[0005] Specifically, the following technical solutions are included:

[0006] A first aspect of an embodiment of the present application provides a rotor core, the rotor core comprising a rotor punching and a plurality of first magnetic parts;

[0007] The rotor punching is provided with a plurality of first installation openings, the plurality of first installation openings are located on the outer peripheral wall of the rotor punching or between the outer peripheral wall and the inner peripheral wall of the rotor punching, and the plurality of first installation openings are arranged at intervals along the circumferential direction of the rotor punching;

[0008] The plurality of first magnetic parts are respectively installed in the plurality of first installation openings, wherein the distance between two adjacent first magnetic parts is greater than an effective magnetic isolation distance, and the effective magnetic isolation distance is a maximum distance to ensure that the magnetic leakage coefficient of the first magnetic part meets the design requirements;

[0009] Among them, each of the first magnetic parts has two first cutting structures, and the two first cutting structures are respectively obtained by chamfering two corners of the first magnetic part close to the outer peripheral wall, and there is a first gap between each of the first cutting structures and the edge of the first mounting opening.

[0010] Optionally, the first installation opening is located on the outer peripheral wall of the rotor punching sheet, the first installation opening comprises a first groove and a second groove, and the second groove is opened on the bottom wall of the first groove;

[0011] The lengths of the first groove and the second groove both extend in the circumferential direction of the rotor punching sheet, and the length of the first groove is greater than the length of the second groove;

[0012] Wherein, the first magnetic part is located in the first groove.

[0013] Optionally, the first installation opening is located on the outer peripheral wall of the rotor punching, a protrusion is formed on the bottom wall of the first installation opening, and the protrusion is located between a first side wall and a second side wall of the first installation opening that are opposite to each other in the annular direction of the rotor punching;

[0014] The first magnetic portion includes two permanent magnets, and the two permanent magnets are respectively located between the protrusion and the first side wall, and between the protrusion and the second side wall.

[0015] Optionally, the height of the protrusion is smaller than the depth of the first mounting opening.

[0016] Optionally, the rotor core also includes a sleeve, which is sleeved on the outer peripheral wall of the rotor punching sheet. The sleeve, the rotor punching sheet and the first cutting structure cooperate to form the cutting space, and the cross-sectional shape of the cutting space is selected from any one of a triangle, a rectangle, a circle and an ellipse.

[0017] Optionally, when the cross-sectional shape of the cutting space is a triangle, the ratio of the first side to the second side of the triangle is in the range of 1-4, the first side is formed by the sleeve, and the second side is formed by the rotor punching.

[0018] Optionally, the first magnetic portion has a second cutting structure, the second cutting structure is located between the two first cutting structures, and a second gap is formed between the second cutting structure and the sleeve.

[0019] Optionally, the first mounting opening is located between the outer circumferential wall and the inner circumferential wall of the rotor punching sheet, the first mounting opening includes a first opening, a second opening and a third opening connected in sequence, the second opening is V-shaped, the first opening and the third opening are respectively connected to two ends of the second opening, and the first magnetic part includes two permanent magnets, and the two permanent magnets are respectively located in the first opening and the third opening.

[0020] Optionally, a plurality of second mounting openings are further provided between the outer peripheral wall and the inner peripheral wall of the rotor punching, the plurality of second mounting openings and the plurality of first mounting openings are alternately arranged along the circumferential direction of the rotor punching, and each of the second mounting openings extends along the radial direction of the rotor punching;

[0021] The rotor core further includes a plurality of second magnetic portions, and the plurality of second magnetic portions are respectively installed in the plurality of second installation openings.

[0022] A second aspect of an embodiment of the present application provides a motor, comprising the above-mentioned rotor core.

[0023] The beneficial effects of the technical solution provided by the embodiments of the present application include at least:

[0024] The rotor core and the motor provided in the embodiment of the present application, on the one hand, adopt a rotor punching of an integrated structure, a plurality of first installation openings are opened on the rotor punching, and a plurality of first magnetic parts are arranged in the plurality of first installation openings on the rotor punching. Compared with the rotor punching composed of a plurality of independent parts in the related art, the rotor punching in the rotor core provided in the embodiment of the present application has higher mechanical strength, so that the motor can adapt to high-speed operating conditions; on the other hand, the distance between any two adjacent first magnetic parts among the plurality of first magnetic parts is designed to be greater than the effective magnetic isolation distance, that is, the magnetic isolation bridge is not arranged on the rotor punching in the embodiment of the present application, so The phenomenon of stress concentration at the magnetic isolation bridge causing the breakage of the punching sheet in the related technology is avoided, and the structural strength of the rotor punching sheet is further guaranteed; on the other hand, in order to ensure the electromagnetic performance of the motor after the magnetic isolation bridge is cancelled, the first magnetic part arranged in the first mounting opening is chamfered so that there is a first gap between the first cutting structure and the edge of the first mounting opening. This can reduce the leakage magnetic field generated by the closed loop formed by the first magnetic part at both ends along the circumference of the rotor punching sheet, and make the magnetic field distribution at the corners of the permanent magnet more uniform, thereby avoiding the demagnetization phenomenon at the corners of the first magnetic part under the influence of the external magnetic field, and effectively improving the power density of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 A schematic diagram of the structure of a rotor punching provided in an embodiment of the present application is shown;

[0027] Figure 2 An enlarged schematic diagram of a second rotor punching provided in an embodiment of the present application is shown;

[0028] Figure 3 An enlarged schematic diagram of a third rotor punching provided in an embodiment of the present application is shown;

[0029] Figure 4An enlarged schematic diagram of a fourth rotor punching provided in an embodiment of the present application is shown;

[0030] Figure 5 An enlarged schematic diagram of the fifth type of rotor punching provided in an embodiment of the present application is shown.

[0031] Reference numerals:

[0032] 1. rotor punching sheet; 11. first installation opening; 111. first groove; 112. second groove; 113. protrusion; 114. first side wall; 115. second side wall; 116. first opening; 117. second opening; 118. third opening; 12. outer peripheral wall; 13. inner peripheral wall; 14. first cutting structure; 15. first gap; 16. second installation opening;

[0033] 2. first magnetic part; 21. permanent magnet; 22. second cutting structure; 23. second gap;

[0034] 3. Sleeve;

[0035] 4. Cutting space;

[0036] 5. The second magnetic part.

[0037] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application. In order to make the technical solutions and advantages of the present application clearer, the rotor core and the motor will be described in detail in combination with the drawings.

[0039] With the rapid development of electric vehicles, the speed and power density of vehicle drive motors are increasingly required, and high speeds will bring greater challenges to the motor structure. Taking the internal permanent magnet motor commonly used in electric vehicles as an example, there is usually a magnetic isolation bridge on the rotor core, which is used for strength support on the one hand and can reduce magnetic leakage on the other hand.

[0040] However, higher motor speeds will bring greater centrifugal force to the rotor, and stress concentration will easily occur on the magnetic isolation bridge, which will lead to fatigue fracture. In order to reduce the risk of damage to the magnetic isolation bridge caused by higher speeds, the thickness of the magnetic isolation bridge is generally set to be relatively thick, but this will increase the risk of motor leakage and reduce the electromagnetic performance of the motor, such as torque and efficiency.

[0041] In order to achieve high power density and reduce magnetic leakage, some motor designs in related technologies eliminate the magnetic isolation bridge and divide the rotor laminations into several independent parts. During installation, each part needs to be fixed separately to ensure installation accuracy, which brings difficulties to mass production assembly.

[0042] In this regard, the present application embodiment provides a rotor core, such as Figure 1 As shown, the rotor core may include a rotor punching 1 and a plurality of first magnetic parts 2; a plurality of first mounting openings 11 are provided on the rotor punching 1, the plurality of first mounting openings 11 are located on the outer peripheral wall 12 of the rotor punching 1 or between the outer peripheral wall 12 and the inner peripheral wall 13 of the rotor punching 1, and the plurality of first mounting openings 11 are arranged at intervals along the circumferential direction of the rotor punching 1; the plurality of first magnetic parts 2 are respectively installed in the plurality of first mounting openings 11, wherein the distance between two adjacent first magnetic parts 2 is greater than the effective magnetic isolation distance, and the effective magnetic isolation distance is the maximum distance to ensure that the magnetic leakage coefficient of the first magnetic part 2 meets the design requirements; wherein each first magnetic part 2 has two first cutting structures 14, the two first cutting structures 14 are respectively obtained by chamfering the two corners of the first magnetic part 2 close to the outer peripheral wall 12, and a first gap 15 is provided between each first cutting structure 14 and the edge of the first mounting opening 11.

[0043] The rotor core provided in the embodiment of the present application, on the one hand, adopts a rotor punching 1 with an integrated structure, a plurality of first installation openings 11 are opened on the rotor punching 1, and a plurality of first magnetic parts 2 are arranged in the plurality of first installation openings 11 on the rotor punching 1. Compared with the rotor punching 1 composed of a plurality of independent parts in the related art, the rotor punching in the rotor core provided in the embodiment of the present application has higher mechanical strength, so that the motor can adapt to high-speed operating conditions; on the other hand, the distance between any two adjacent first magnetic parts 2 in the plurality of first magnetic parts 2 is designed to be greater than the effective magnetic isolation distance, that is, the magnetic isolation bridge is not arranged on the rotor punching 1 in the embodiment of the present application, thereby avoiding The phenomenon of stress concentration at the magnetic isolation bridge causing the breakage of the punching sheet in the related technology is solved, and the structural strength of the rotor punching sheet is further ensured; on the other hand, in order to ensure the electromagnetic performance of the motor after the magnetic isolation bridge is eliminated, the first magnetic part 2 arranged in the first mounting opening 11 is chamfered, so that there is a first gap 15 between the first cutting structure 14 and the edge of the first mounting opening 11, which can reduce the leakage magnetic field generated by the closed loop formed by the first magnetic part 2 at both ends of the circumference of the rotor punching sheet 1, and make the magnetic field distribution at the corners of the permanent magnet more uniform, thereby avoiding the demagnetization phenomenon at the corners of the first magnetic part 2 under the influence of the external magnetic field, and effectively improving the power density of the motor.

[0044] Among them, for the embodiment of the present application, the first cutting structure 14 is obtained by cutting at the corners of the first magnetic part 2 to avoid demagnetization at the corners of the permanent magnet, which is explained as follows:

[0045] Generally speaking, the magnetic field lines at the corners of a permanent magnet are more concentrated, resulting in a relatively greater magnetic field strength at that location. If the external magnetic field strength exceeds the coercive force of the permanent magnet, demagnetization will occur. The coercive force of a magnet refers to the ability of a magnet to reduce its magnetization strength to zero after it is fully magnetized by the required reverse magnetic field strength. In other words, the greater the coercive force, the stronger the magnet's ability to maintain its magnetism, and the less likely it is to demagnetize.

[0046] In the embodiment of the present application, by cutting the corners of the first magnetic part 2, a first cutting structure 14 can be formed at the edge of the first magnetic part 2, and the first cutting structure 14 has a first distance from the center of the first magnetic part 2. It is easy to understand that the second distance between the corners and the center of the first magnetic part 2 before cutting is obviously greater than the first distance, so the coercive force at the first cutting structure 14 is relatively larger and less prone to demagnetization. In addition, the first cutting structure 14 formed after the chamfering process changes the shape of the corners of the first magnetic part 2, making the magnetic field distribution more uniform, so it can also improve the ability to resist external magnetic field interference to a certain extent, and further prevent demagnetization.

[0047] It should be noted that, in the embodiment of the present application, the polarities of the two magnetic poles close to each other in two adjacent first magnetic parts 2 are generally opposite, that is, in two adjacent first magnetic parts 2, the magnetic pole of one first magnetic part 2 close to one end of the other first magnetic part 2 is the S pole, and the magnetic pole of the other first magnetic part 2 close to one end of the first magnetic part 2 is the N pole. The magnetic lines of force of one first magnetic part 2 are emitted from its own S pole through the rotor punching 1 to the N pole of the other adjacent first magnetic part 2, and the N pole of the other first magnetic part 2 receives the magnetic lines of force emitted by the S pole of the first magnetic part to form a magnetic circuit.

[0048] In some embodiments of the present application, Figure 1 As shown, the first installation opening 11 is located on the outer peripheral wall 12 of the rotor punching 1, and the opening side of the first installation opening 11 is located at the edge of the outer peripheral wall of the rotor punching 1 to ensure that the rest of the rotor punching 1 is an integrated structure.

[0049] Continue to see Figure 1 The first mounting opening 11 may include a first groove 111 and a second groove 112, the lengths of the first groove 111 and the second groove 112 both extend along the circumferential direction of the rotor punching 1, and the length of the first groove 111 is greater than the length of the second groove 112; wherein the second groove 112 is opened on the bottom wall of the first groove 111, and the first magnetic part 2 is located in the first groove 111.

[0050] Optionally, the bottom wall of the first groove 111 is selected from any one of a curved surface and a flat surface, and the bottom wall of the second groove 112 is any one of a curved surface or a flat surface. When the bottom wall is a flat surface, the processing difficulty is relatively low. Those skilled in the art can select and adjust according to actual needs. For example, see Figure 1 The bottom wall of the first groove is a curved surface, and the bottom wall of the second groove is a plane, which extends along the tangential direction of the rotor punching sheet 1.

[0051] Optionally, the first magnetic part 2 is arranged in the first groove 111. Since the second groove 112 is arranged on the bottom wall of the first groove 111, there is a certain gap between the first magnetic part 2 installed in the first groove 111 and the bottom wall of the second groove 112, which is equivalent to forming an air groove between the first magnetic part 2 and the rotor punching 1. The magnetic resistance of the air in the air groove is greater than the magnetic resistance of the sheet material of the rotor punching 1, thereby increasing the magnetic resistance on the leakage magnetic path of the first magnetic part 2, so that the leakage magnetic path of the first magnetic part 2 is not connected by magnetic conductive materials, thereby reducing the leakage magnetic flux caused by the closed loop formed at both ends of the first magnetic part 2, improving the magnetic circuit structure, and enhancing the sinusoidal nature of the air gap magnetic density.

[0052] In this embodiment, by providing air slots, the path of the magnetic flux is changed, so that the magnetic field is more evenly distributed at both ends of the magnet, thereby improving the distribution of the magnetic flux density; and the air slots can play a role in isolating the magnetic flux linkage, preventing the magnetic force lines from jumping directly from one end to the other end, so that the magnetic field is more concentrated in the air gap, and the magnetic flux density of the air gap is improved. The following air slots can all enhance the sinusoidality of the air gap magnetic flux density of the motor, and this application does not make too many details about this.

[0053] Optionally, the depth of the second groove 112 is less than the depth of the first groove 111, wherein the depth direction is parallel to the radial direction of the rotor punching 1. Those skilled in the art can select and adjust the depth of the second groove 112 according to actual needs.

[0054] In some embodiments of the present application, Figure 2 As shown, the first mounting opening 11 is located on the outer peripheral wall 12 of the rotor punching 1, and a protrusion 113 is formed on the bottom wall of the first mounting opening 11, and the protrusion 113 is located between the first side wall 114 and the second side wall 115 of the first mounting opening 11 which are opposite to each other in the annular direction of the rotor punching 1; the first magnetic part 2 includes two permanent magnets 21, and the two permanent magnets 21 are respectively located between the protrusion 113 and the first side wall 114, and between the protrusion 113 and the second side wall 115.

[0055] In the rotor core provided by the embodiment of the present application, since the length direction of the first groove 111 is parallel to the circumferential direction of the rotor punching sheet 1, that is, when the shape of the first groove 111 is a curved long strip, the processing difficulty of the first magnetic part 2 will be increased; therefore, the first magnetic part 2 may include two permanent magnets 21, which are respectively installed on both sides of the protrusion 113 in the first installation opening 11, and the two ends of one permanent magnet 21 are respectively abutted against the first side wall 114 and the protrusion 113, and the two ends of the other permanent magnet 21 are respectively abutted against the second side wall 115 and the protrusion 113. Compared with the above embodiment, the present embodiment has a lower requirement on the length of the first magnetic part 2, and two sections of shorter permanent magnets 21 can be used as the first magnetic part 2, which ensures the structural strength and power density of the rotor punching sheet 1, while reducing the processing difficulty of the first magnetic part 2, and can meet the processing needs of large quantities.

[0056] Optionally, since the length direction of the first groove 111 is parallel to the circumferential direction of the rotor punching sheet 1, that is, the shape of the first groove 111 is a curved strip, the processing difficulty of the first magnetic part 2 will be increased. Therefore, the number of protrusions 113 can be more than one, and more than one protrusion 113 divides the first installation opening 11 provided on the outer peripheral wall of the rotor punching sheet 1 into multiple sections of grooves. The first magnetic part 2 includes multiple permanent magnets 21, and the multiple permanent magnets 21 are respectively installed in multiple grooves. By splitting the first magnetic part 2 into multiple permanent magnets 21 with shorter lengths, the convenience of processing is improved. Those skilled in the art can select and adjust the number of protrusions 113 according to actual needs.

[0057] In some embodiments of the present application, Figure 3 As shown, the height of the protrusion 113 is smaller than the depth of the first installation opening 11 .

[0058] In the rotor core provided in the embodiment of the present application, two permanent magnets 21 are respectively installed on both sides of the protrusion 113, and the height of the protrusion 113 is less than the depth of the first installation opening 11, so that an air slot is formed between the two permanent magnets 21. Since the magnetic resistance of the air in the air slot is relatively large, the magnetic resistance of the permanent magnet 21 on the leakage magnetic path is increased, and the end leakage magnetic field of the permanent magnet 21 is reduced, thereby further improving the magnetic circuit structure and improving the power density of the motor.

[0059] In some embodiments of the present application, Figure 1 As shown, the rotor core also includes a sleeve 3, which is sleeved on the outer peripheral wall 12 of the rotor punching 1. The sleeve 3, the rotor punching 1 and the first cutting structure 14 cooperate to form a cutting space 4, and the cross-sectional shape of the cutting space 4 is selected from any one of a triangle, a rectangle, a circle and an ellipse.

[0060] In the rotor core provided in the embodiment of the present application, a sleeve 3 can also be sleeved on the outside of the rotor punching 1, which can, on the one hand, strengthen the structural strength of the rotor punching 1, share the centrifugal force generated by the high-speed rotation of the rotor punching 1 when the rotor punching 1 rotates at high speed, and realize the high-speed operation of the rotor punching 1; on the other hand, the sleeve 3, the first cutting structure 14 and the side wall of the first installation opening 11 enclose a cutting space 4, that is, an air groove is formed at the chamfered position, which avoids the demagnetization of the corners of the permanent magnet under the influence of the external magnetic field, while improving the magnetic resistance of the first magnetic part 2 on the leakage magnetic path, reducing the leakage magnetic flux at both ends of the first magnetic part 2, and enhancing the sinusoidal nature of the air gap magnetic flux density. It should be noted that the cutting shape during the chamfering process can be selected according to actual needs, as long as the distance between the first cutting structure 14 formed after cutting and the center of the first magnetic part 2 can be reduced.

[0061] In some embodiments of the present application, when the cross-sectional shape of the cutting space 4 is a triangle, the ratio of the first side to the second side of the triangle ranges from 1 to 4, the first side is formed by the sleeve 3, and the second side is formed by the rotor punching 1.

[0062] In some embodiments, a first mounting opening 11 is opened on the outer peripheral wall 12 of the rotor punching 1, the first magnetic part 2 is arranged in the first mounting opening 11, the sleeve 3 is sleeved on the outer peripheral wall 12 of the rotor punching 1, and together with the first cutting structure 14 and the side wall of the first mounting opening 11, a triangular cutting space 4 is formed, and the length of the first side of the triangle is between 2-4 mm, and the length of the second side is between 1-2 mm. The rotor punching 1 forms an air groove at the chamfered position, which reduces the risk of demagnetization at the corner position, and at the same time increases the magnetic resistance of the permanent magnet 21 on the leakage magnetic path, thereby reducing the leakage magnetic flux at both ends of the first magnetic part 2.

[0063] Optionally, those skilled in the art may adjust the sizes of the first side and the second side of the triangle according to actual needs and the size of the first magnetic portion, as long as the above ratio range is satisfied.

[0064] In some embodiments of the present application, Figure 4 As shown, the first magnetic part 2 has a second cutting structure 22 . The second cutting structure 22 is located between the two first cutting structures 14 . A second gap 23 is defined between the second cutting structure 22 and the sleeve 3 .

[0065] In the rotor core provided in the embodiment of the present application, the wall of the first magnetic part 2 away from the center of the rotor punching sheet 1 can also be cut, and the cut part is located between the two first cutting structures 14. Therefore, the distance between the second cutting structure 22 formed after cutting and the center of the first magnetic part 2 is smaller than the distance between the cut part and the center of the first magnetic part 2 before cutting. Therefore, the magnetic field strength at the second cutting structure 22 is stronger, and it is less likely to be demagnetized under the influence of the external magnetic field, thereby improving the power density of the motor.

[0066] Optionally, a sleeve 3 is sleeved on the outer peripheral wall 12 of the rotor punching sheet 1, and the sleeve 3 and the second cutting structure 22 together form an air groove, which increases the magnetic resistance of the first magnetic part 2 on the leakage magnetic path, reduces the leakage magnetic of the first magnetic part 2 at the second cutting structure 22, and enhances the sinusoidal property of the air gap magnetic density.

[0067] Optionally, the first magnetic part 2 includes two permanent magnets 21, and the two corners of the two permanent magnets 21 away from the bottom wall of the first installation opening 11 are chamfered, and the position where the two permanent magnets 21 directly abut against each other forms the above-mentioned second cutting structure 22. Since the first magnetic part 2 can be composed of two smaller permanent magnets 21, the processing difficulty of the first magnetic part 2 is reduced compared to the one-piece structure.

[0068] In some embodiments of the present application, Figure 5 As shown, the first installation opening 11 is located between the outer circumferential wall 12 and the inner circumferential wall 13 of the rotor punching 1, and the first installation opening 11 includes a first opening 116, a second opening 117 and a third opening 118 which are connected in sequence, and the second opening 117 is V-shaped, and the first opening 116 and the third opening 118 are respectively connected to the two ends of the second opening 117, and the first magnetic part 2 includes two permanent magnets 21, and the two permanent magnets 21 are respectively located in the first opening 116 and the third opening 118.

[0069] In the rotor core provided in the embodiment of the present application, the first installation opening 11 can also be arranged between the inner peripheral wall 13 and the outer peripheral wall 12 of the rotor punching 1. Compared with the first installation opening 11 being opened on the outer peripheral wall 12 of the rotor punching 1, it has higher structural strength. After the sleeve 3 is sleeved on the outer peripheral wall 12 of the rotor punching 1, the high-speed rotation of the motor can be achieved. In addition, the first magnetic part 2 is divided into two permanent magnets 21, which are respectively arranged in the first opening 116 and the third opening 118. There is also a gap between the two permanent magnets 21, which reduces the leakage flux formed by the end of the permanent magnet 21 through the rotor punching 1 and improves the magnetic circuit structure.

[0070] Optionally, the width of the first opening 116 and the third opening 118 is greater than the width of the second opening 117, and the permanent magnet 21 can be stuck at the connection between the first opening 116 and the second opening 117, or at the connection between the third opening 118 and the second opening 117, without the need to set up an additional connection structure to fix the permanent magnet 21.

[0071] In some embodiments of the present application, Figures 1 to 5 A plurality of second mounting openings 16 are also provided between the outer circumferential wall 12 and the inner circumferential wall 13 of the rotor punching 1. The plurality of second mounting openings 16 and the plurality of first mounting openings 11 are alternately arranged in the circumferential direction of the rotor punching 1, and each second mounting opening 16 extends in the radial direction of the rotor punching 1. The rotor core also includes a plurality of second magnetic portions 5, which are respectively mounted in the plurality of second mounting openings 16.

[0072] In order to improve the power density of the motor, a second installation opening 16 extending radially is further provided on the rotor punching 1, and a second magnetic portion 5 is installed. Compared with a motor with only tangential permanent magnets 21, the magnetic flux in the rotor punching 1 is strengthened, thereby improving the power density of the motor.

[0073] In some embodiments, Figure 1As shown, a plurality of first installation openings 11 and a second installation opening 16 are provided between the outer peripheral wall 12 and the inner peripheral wall 13 of the rotor punching 1, the length direction of the first installation opening 11 is parallel to the tangential direction of the rotor punching 1, and the second installation opening 16 extends along the radial direction of the rotor punching 1, and a plurality of first magnetic parts 2 are respectively arranged in the plurality of first installation openings 11, and the corners at both ends of the first magnetic parts 2 are chamfered, and there are gaps between the side walls of the first installation openings 11, thereby reducing the risk of demagnetization at the corner positions, and the first magnetic parts 2 and the first installation openings 16 are arranged in a radial direction of the rotor punching 1. The side walls of the opening 11 and the sleeve 3 form an air groove, which increases the magnetic resistance of the leakage magnetic path, so that the leakage magnetic path at the end of the first magnetic part 2 is not connected with magnetic conductive material, thereby reducing the leakage magnetic flux formed by the end of the first magnetic part 2 through the rotor punching 1; the multiple second magnetic parts 5 are respectively arranged in the multiple second installation openings 16, which increases the central magnetic flux of the rotor punching 1, thereby increasing the power density of the motor; the sleeve 3 is sleeved on the outer peripheral wall 12 of the rotor punching 1, which strengthens the structural strength of the rotor punching 1, so that the motor using the rotor punching 1 can adapt to the working conditions of high speed.

[0074] An embodiment of the present application also provides a motor, comprising the above-mentioned rotor core.

[0075] The motor provided in the embodiment of the present application, on the one hand, adopts a rotor punching 1 with an integrated structure, a plurality of first installation openings 11 are opened on the rotor punching 1, and a plurality of first magnetic parts 2 are arranged in the plurality of first installation openings 11 on the rotor punching 1. Compared with the rotor punching 1 composed of a plurality of independent parts in the related art, the rotor punching in the rotor core provided in the embodiment of the present application has higher mechanical strength, so that the motor can adapt to high-speed operating conditions; on the other hand, the distance between any two adjacent first magnetic parts 2 in the plurality of first magnetic parts 2 is designed to be greater than the effective magnetic isolation distance, that is, the magnetic isolation bridge is not arranged on the rotor punching 1 in the embodiment of the present application, thereby avoiding In the related technology, stress concentration occurs at the magnetic isolation bridge, resulting in the fracture of the punching sheet, which further ensures the structural strength of the rotor punching sheet; on the other hand, in order to ensure the electromagnetic performance of the motor after the magnetic isolation bridge is eliminated, the first magnetic part 2 arranged in the first mounting opening 11 is chamfered so that there is a first gap 15 between the first cutting structure 14 and the edge of the first mounting opening 11. This can reduce the leakage magnetic field generated by the closed loop formed by the first magnetic part 2 at both ends of the circumference of the rotor punching sheet 1, and make the magnetic field distribution at the corners of the permanent magnet more uniform, thereby avoiding the demagnetization phenomenon at the corners of the first magnetic part 2 under the influence of the external magnetic field, and effectively improving the power density of the motor.

[0076] In the present application, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. The term "plurality" refers to two or more than two, unless otherwise clearly defined.

[0077] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the utility model disclosed herein. The present application is intended to cover any variations, uses or adaptations of the present application, which follow the general principles of the present application and include common knowledge or customary technical means in the art that are not disclosed in the present application. The specification and examples are intended to be exemplary only.

[0078] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A rotor core, characterized in that: The rotor core comprises a rotor punching sheet (1) and a plurality of first magnetic parts (2); The rotor punching (1) is provided with a plurality of first installation openings (11), the plurality of first installation openings (11) are located on the outer peripheral wall (12) of the rotor punching (1) or between the outer peripheral wall (12) and the inner peripheral wall (13) of the rotor punching (1), and the plurality of first installation openings (11) are arranged at intervals along the annular direction of the rotor punching (1); The plurality of first magnetic parts (2) are respectively installed in the plurality of first installation openings (11), wherein the distance between two adjacent first magnetic parts (2) is greater than an effective magnetic isolation distance, wherein the effective magnetic isolation distance is a maximum distance that ensures that the magnetic leakage coefficient of the first magnetic part (2) meets design requirements; Each of the first magnetic parts (2) has two first cutting structures (14), and the two first cutting structures (14) are respectively obtained by chamfering two corners of the first magnetic part (2) on a side close to the outer peripheral wall (12), and a first gap (15) is provided between each of the first cutting structures (14) and the edge of the first mounting opening (11).

2. The rotor core according to claim 1, characterized in that: The first installation opening (11) is located on the outer peripheral wall (12) of the rotor punching sheet (1), the first installation opening (11) comprises a first groove (111) and a second groove (112), and the second groove (112) is opened on the bottom wall of the first groove (111); The lengths of the first groove (111) and the second groove (112) both extend in the circumferential direction of the rotor punching sheet (1), and the length of the first groove (111) is greater than the length of the second groove (112); Wherein, the first magnetic part (2) is located in the first groove (111).

3. The rotor core according to claim 1, characterized in that: The first installation opening (11) is located on the outer peripheral wall (12) of the rotor punching sheet (1), a protrusion (113) is formed on the bottom wall of the first installation opening (11), and the protrusion (113) is located between a first side wall (114) and a second side wall (115) of the first installation opening (11) that are opposite to each other in the annular direction of the rotor punching sheet (1); The first magnetic part (2) comprises two permanent magnets (21), and the two permanent magnets (21) are respectively located between the protrusion (113) and the first side wall (114), and between the protrusion (113) and the second side wall (115).

4. The rotor core according to claim 3, characterized in that: The height of the protrusion (113) is smaller than the depth of the first installation opening (11).

5. The rotor core according to any one of claims 2 to 4, characterized in that: The rotor core further comprises a sleeve (3), wherein the sleeve (3) is sleeved on the outer peripheral wall (12) of the rotor punching sheet (1), and the sleeve (3), the rotor punching sheet (1) and the first cutting structure (14) cooperate to form a cutting space (4), wherein the cross-sectional shape of the cutting space (4) is selected from any one of a triangle, a rectangle, a circle and an ellipse.

6. The rotor core according to claim 5, characterized in that: When the cross-sectional shape of the cutting space (4) is a triangle, the ratio of the first side to the second side of the triangle is in the range of 1-4, the first side is formed by the sleeve (3), and the second side is formed by the rotor punching (1).

7. The rotor core according to claim 5, characterized in that: The first magnetic part (2) has a second cutting structure (22), the second cutting structure (22) is located between the two first cutting structures (14), and a second gap (23) is provided between the second cutting structure (22) and the sleeve (3).

8. The rotor core according to claim 1, characterized in that: The first installation opening (11) is located between an outer peripheral wall (12) and an inner peripheral wall (13) of the rotor punching sheet (1); the first installation opening (11) comprises a first opening (116), a second opening (117) and a third opening (118) which are connected in sequence; the second opening (117) is V-shaped; the first opening (116) and the third opening (118) are respectively connected to two ends of the second opening (117); the first magnetic part (2) comprises two permanent magnets (21); the two permanent magnets (21) are respectively located in the first opening (116) and the third opening (118).

9. The rotor core according to claim 1, characterized in that: A plurality of second mounting openings (16) are also provided between the outer peripheral wall (12) and the inner peripheral wall (13) of the rotor punching sheet (1), the plurality of second mounting openings (16) and the plurality of first mounting openings (11) being arranged alternately along the circumferential direction of the rotor punching sheet (1), and each of the second mounting openings (16) extending along the radial direction of the rotor punching sheet (1); The rotor core further comprises a plurality of second magnetic parts (5), and the plurality of second magnetic parts (5) are respectively mounted on the plurality of second mounting openings (16).

10. A motor, characterized in that: The rotor core comprises the rotor core as claimed in any one of claims 1 to 9.

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