Rotor assembly, motor and compressor

Abstract

The invention provides a rotor assembly, a motor and a compressor, the rotor assembly comprises at least two mutually stacked rotor punching sheets, each rotor punching sheet is provided with a first punching sheet structure and at least two second punching sheet structures, and the at least two second punching sheet structures are arranged around the circumferential direction of the first punching sheet structure. A gap is formed between every two adjacent second punching sheet structures; an accommodating groove for accommodating the magnet is formed between the first punching sheet structure and the second punching sheet structure, and the accommodating groove is communicated with the gap; at least one rotor punching sheet is provided with a first connecting structure, and the first connecting structure is arranged between the adjacent second punching sheet structures and blocks the gap; and the first connecting structure is made of a non-magnetic material. The accommodating grooves are communicated with the outside through the gaps, so that no magnetic isolation bridge is arranged on the rotor punching sheet, and the magnetic leakage of the magnet is reduced; and meanwhile, the first connecting structure can fix the magnet, so that the magnet is prevented from moving in the high-speed rotation process of the rotor assembly, and the stability of the rotor assembly is further improved.

Description

Technical Field

[0001] This application relates to the field of compressor technology, specifically to a rotor assembly, a motor, and a compressor. Background Technology

[0002] In electric motors, the design of rotor magnetic poles is a key technology. Magnetic poles can have tangential, radial, and mixed magnetic circuits. Compressor motor magnet slots are generally of the straight line or V-shape, and magnetic isolation bridges are set between each magnetic pole. However, the magnetic isolation effect is not ideal, and magnetic leakage still exists. Summary of the Invention

[0003] In view of this, the embodiments of this application aim to provide a rotor assembly, a motor, and a compressor to solve the problem of unsatisfactory magnetic shielding effect of existing rotor lamination structures.

[0004] To address the aforementioned problems, this application provides a rotor assembly, comprising: At least two stacked rotor laminations; each rotor lamination has a first lamination structure and at least two second lamination structures, the at least two second lamination structures being arranged circumferentially around the first lamination structure, and a gap being between adjacent second lamination structures; a receiving groove for accommodating a magnet is formed between the first lamination structure and the second lamination structure, the receiving groove communicating with the gap; At least one of the rotor laminations has a first connecting structure disposed between adjacent second lamination structures and sealing the gap; the first connecting structure is made of a non-magnetic material.

[0005] In one embodiment, at least one of the rotor laminations has a second connecting structure, which connects the first lamination structure and the second lamination structure respectively.

[0006] In one embodiment, the rotor assembly includes a rotor core formed by coaxially stacking at least two rotor laminations; Wherein, the number of rotor laminations with the first connection structure is N, and the number of rotor laminations with the second connection structure is n, then N≥n.

[0007] In one embodiment, the rotor assembly includes a first rotor lamination having the first connection structure, and the first lamination structure and the second lamination structure in the first rotor lamination are separated from each other.

[0008] In one embodiment, the rotor assembly includes a second rotor lamination, the second connection structure includes a first connection substructure, and the second rotor lamination has the first connection substructure. The first connecting substructure connects the first lamination structure in the second rotor lamination and two adjacent second lamination structures respectively.

[0009] In one embodiment, the receiving slot has two receiving sub-slots, and each receiving sub-slot is provided with one of the magnets; The receiving sub-slot has a connecting end and an extension end arranged opposite to each other, the connecting ends of the two receiving sub-slots are connected to each other, and the extension ends are respectively arranged in different directions toward the edge of the rotor lamination. The first connecting substructure is connected at the extension end to the first lamination structure and two adjacent second lamination structures respectively.

[0010] In one embodiment, the rotor assembly includes a rotor core formed by coaxially stacking at least two rotor laminations; The rotor core is provided with a first end plate and a second end plate at both ends along its own axial direction, and the rotor core has a first stacked section, a second stacked section and a third stacked section along its own axial direction. The first stacking segment is disposed close to the first end plate, the second stacking segment is disposed close to the second end plate, and the third stacking segment is located between the first stacking segment and the second stacking segment; The first rotor lamination is disposed in the third stacking section, and the second rotor lamination is disposed in both the first stacking section and the second stacking section.

[0011] In one embodiment, the first stacking segment is provided with n1 second rotor laminations, the second stacking segment is provided with n2 second rotor laminations, and the third stacking segment is provided with n3 first rotor laminations, then 5≤n1≤10, 5≤n2≤10, and 90≤n3≤118.

[0012] In one embodiment, the rotor assembly includes a third rotor lamination, and the second connection structure has a second connection substructure; The third rotor lamination has the first connecting structure and the second connecting substructure, and the second connecting substructure connects the first lamination structure and the second lamination structure in the third rotor lamination respectively.

[0013] In one embodiment, the receiving slot has two receiving sub-slots, and each receiving sub-slot is provided with one of the magnets; The receiving sub-slot has a connecting end and an extension end arranged opposite to each other. The connecting ends of the two receiving sub-slots are close to each other, and the extension ends pass through the edge of the rotor lamination in different directions and are respectively connected to the outside. The second connecting substructure is disposed at the connecting end so that the two receiving sub-slots are isolated from each other.

[0014] In one embodiment, the rotor assembly includes a rotor core formed by coaxially stacking at least two of the third rotor laminations.

[0015] In one embodiment, the first lamination structure is provided with a connecting portion, and the first connecting structure has an abutting portion that matches the connecting portion, and the first connecting structure is connected to the connecting portion through the abutting portion.

[0016] In one embodiment, the connecting portion includes a recess or a protrusion; The recess is radially recessed along the rotor lamination and forms an opening at the edge of the first lamination structure; or... The protrusion protrudes radially outward along the rotor lamination.

[0017] To address the aforementioned technical problems, this application also provides an electric motor, including a stator assembly and a rotor assembly as described above.

[0018] In one embodiment, the stator assembly includes a stator core, and the rotor assembly includes a rotor core; The rotor core and the stator core are coaxially arranged, and the stator core is located around the rotor core. The distance between the outer contour of the rotor core and the inner contour of the stator core is L1. The opening size of the recess in the rotor assembly is L2. The maximum distance between the recess in the rotor assembly along the radial direction of the rotor lamination and the inner contour of the stator core is L3. Then L1 < L2 and L1 < L3.

[0019] To address the aforementioned technical problems, this application also provides a compressor, including the rotor assembly described above.

[0020] Compared with existing rotor lamination structures, the rotor assembly provided in this application has the following advantages: This application provides a rotor assembly including at least two stacked rotor laminations. Each rotor lamination has a first lamination structure and at least two second lamination structures. The at least two second lamination structures are arranged circumferentially around the first lamination structure, and there is a gap between adjacent second lamination structures. A receiving groove for accommodating a magnet is formed between the first lamination structure and the second lamination structure, and the receiving groove communicates with the gap. At least one rotor lamination has a first connecting structure, which is disposed between adjacent second lamination structures and seals the gap. The first connecting structure is made of a non-magnetic material. The receiving slot is connected to the outside through a gap, so that there is no magnetic bridge on the rotor lamination, thereby reducing magnetic leakage of the magnet. The first connecting structure is made of non-magnetic material and is set between adjacent second lamination structures to seal the gap, thereby blocking the magnetic leakage path of the magnet, improving the magnetic concentration of the rotor lamination, and making the magnetic field generated by the magnet flow only in the air gap, increasing the magnetic field strength in the air gap and increasing the Ke value accordingly. At the same time, the setting of the first connecting structure can also fix the magnet, preventing the magnet from moving during the high-speed rotation of the rotor assembly, further improving the stability of the rotor assembly, and reducing the noise generated during the rotation of the rotor assembly. Attached Figure Description

[0021] Figure 1 The image shown is a cross-sectional view of the motor structure provided in an embodiment of this application.

[0022] Figure 2 The diagram shown is a structural schematic of the first rotor lamination provided in the embodiment of this application.

[0023] Figure 3 The diagram shown is a structural schematic of the second type of first rotor lamination provided in an embodiment of this application.

[0024] Figure 4 The diagram shown is a structural schematic of the second rotor lamination provided in an embodiment of this application.

[0025] Figure 5 The diagram shown is a structural schematic of the third rotor lamination provided in an embodiment of this application.

[0026] Figure 6 The diagram shows the structure of the first end plate and the second end plate provided in the embodiment of this application.

[0027] Figure 7 The diagram shown is a schematic diagram of the first arrangement of the rotor core provided in the embodiment of this application.

[0028] Figure 8 The diagram shown is a second arrangement of the rotor core provided in an embodiment of this application.

[0029] Figure 9 The diagram shown is a schematic diagram of the first connection structure provided in an embodiment of this application.

[0030] Figure 10 As shown Figure 1 A magnified view of a portion of the image.

[0031] The explanations of the reference numerals in the accompanying drawings are as follows: 10-First rotor lamination; 11-Second rotor lamination; 12-Third rotor lamination; 100-First lamination structure; 101-Second lamination structure; 102-Accommodating groove; 103-Accommodating sub-groove; 104-Protrusion; 105-Connecting part; 106-Abutting part; 20 - First connection structure; 30 - Second connecting structure; 301 - First connecting substructure; 302 - Second connecting substructure; 40 - First end plate; 41 - Second end plate; 50 - Rotor core; 500 - First stacking section; 501 - Second stacking section; 502 - Third stacking section; 60-Magnet; 70-Stator core; 80-Rivet hole; 81-Rivet point. Detailed Implementation

[0032] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0033] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "circumferential", "radial", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0034] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0035] As will be understood by those skilled in the art, magnetic bridges are typically made of silicon steel sheets with high permeability. The magnetic bridge itself is very thin, which allows magnetic flux to quickly reach magnetic saturation when passing through this part, thereby effectively blocking the occurrence of magnetic leakage paths and guiding more magnetic flux to the air gap to generate effective torque.

[0036] However, when a magnetic bridge reaches magnetic saturation, it cannot completely isolate magnetic flux; it can only reduce the amount of magnetic flux passing through it from a large flow rate to a small flow rate. From an electromagnetic perspective, the narrower the width of the magnetic bridge, the better, ideally even none at all, as this results in infinitely high magnetic resistance in the leakage path, further reducing leakage flux. However, from a mechanical perspective, the rotor core needs to withstand enormous centrifugal force during high-speed rotation. The magnetic bridge, as a mechanical structure connecting the inside and outside of the rotor core, needs sufficient load-bearing capacity to ensure that the rotor core does not break or undergo plastic deformation during high-speed rotation.

[0037] In summary, existing technologies that use magnetic bridges to reduce magnetic leakage cannot simultaneously achieve both magnetic shielding performance and load-bearing capacity.

[0038] Based on this, please refer to Figures 1-3 This application provides a rotor assembly including at least two stacked rotor laminations. Each rotor lamination has a first lamination structure 100 and at least two second lamination structures 101. The at least two second lamination structures 101 are arranged circumferentially around the first lamination structure 100, and a gap exists between adjacent second lamination structures 101. A receiving groove 102 for accommodating a magnet 60 is formed between the first lamination structure 100 and the second lamination structure 101, and the receiving groove 102 communicates with the gap. At least one rotor lamination has a first connecting structure 20, which is disposed between adjacent second lamination structures 101 and seals the gap. The first connecting structure 20 is made of a non-magnetic material. It should be noted that the aforementioned second lamination structures 101 are located around the periphery of the first lamination structure 100.

[0039] As those skilled in the art will understand, although the traditional narrow magnetic bridge structure can effectively reduce magnetic leakage, it is still essentially a magnetic conduction path made of silicon steel sheets. As long as this path exists, no matter how easily the magnetic bridge can reach magnetic saturation, a small amount of magnetic flux will always pass through, forming residual magnetic leakage. In this embodiment, the receiving groove 102 is directly connected to the outside through the gap between the second lamination structures 101 to form an air groove to replace the original magnetic bridge structure. The magnetic reluctance of air is much higher than that of silicon steel sheets in a magnetically saturated state, thus fundamentally cutting off the leakage magnetic path. At the same time, this embodiment sets a first connecting structure 20 made of non-magnetic material at the gap. On the one hand, it can further block the leakage magnetic path and maximize the utilization of the magnet 60. More magnetic flux is guided into the air gap, increasing the magnetic field strength in the air gap, which helps to improve torque and power density. Moreover, the disconnect between the first lamination structure 100 and the second lamination structure 101 can significantly increase the magnetic reluctance difference between the direct axis and the quadrature axis of the rotor core 50, thereby generating a larger magnetic reluctance torque. On the other hand, the first connecting structure 20 can also help fix the magnet 60 in the receiving groove 102, preventing the magnet 60 from moving during the high-speed rotation of the rotor core 50, further improving the operating stability of the rotor assembly.

[0040] Alternatively, the first connecting structure 20 can be made of non-magnetic materials such as austenitic stainless steel, nickel-based alloy, graphite, resin, engineering plastics, ceramics, or glass fiber; the magnet 60 can be a permanent magnet made of hard magnetic materials such as neodymium iron boron or samarium cobalt; the first lamination structure 100 and the second lamination structure 101 can be made of silicon steel sheets. This embodiment does not limit this, and those skilled in the art can configure the materials of the above structures according to actual needs.

[0041] As an optional embodiment, the rotor core 50 is formed by at least two rotor laminations stacked coaxially. In this embodiment, the rotor laminations eliminate the design of the magnetic bridge. When the rotor core 50 rotates at high speed, the second lamination structure 101 needs to withstand a large centrifugal force, which may cause it to fly outwards and thus affect the mechanical strength of the rotor core 50.

[0042] Based on this, please refer to Figure 1 In this embodiment, rivet holes 80 and rivet points 81 are provided on the second lamination structure 101. By inserting rivets through the rivet holes 80 and cooperating with the rivet points 81 to achieve connection, the mechanical strength of the rotor core 50 is further improved. Meanwhile, as... Figures 4-5As shown, at least one rotor lamination is provided with a second connecting structure 30, which connects the first lamination structure 100 and the second lamination structure 101 respectively, so that the formed rotor core 50 can be integrated as a whole, preventing some components from flying outward under centrifugal force during rotation. In some other embodiments, high-strength carbon fiber or glass fiber straps can be used to bind the rotor core 50, or a non-magnetic high-strength sleeve (such as a carbon fiber sleeve, alloy sleeve, etc.) can be used to fit around the rotor core 50, thereby improving the overall strength of the rotor core 50.

[0043] As an example, in this embodiment, at least two rotor laminations stacked to form the rotor core 50 need to have a first connecting structure 20 and a second connecting structure 30 to further reduce magnetic leakage while ensuring the mechanical strength of the rotor core 50. Specifically, the rotor laminations can have various structural forms, such as a first rotor lamination 10 with only the first connecting structure 20, a second rotor lamination 11 with only the second connecting structure 30, and a third rotor lamination 12 with both the first connecting structure 20 and the second connecting structure 30.

[0044] When forming the rotor core 50, the first rotor lamination 10 and the second rotor lamination 11 can be used in combination, or a third rotor lamination 12 can be used. In the configuration process, it is preferable to set the number of rotor laminations with the first connecting structure 20 to N and the number of rotor laminations with the second connecting structure 30 to n, satisfying N≥n, so as to take into account mechanical strength while prioritizing the reduction of leakage flux.

[0045] Optionally, in some motors with extremely high requirements for efficiency and power density, the rotor core 50 is formed by combining the first rotor lamination 10 and the second rotor lamination 11 to maximize the utilization of the magnet 60's performance while ensuring that the formed rotor core 50 is integral. In some motors with strict cost control, the rotor core 50 is formed by using the third rotor lamination 12 to reduce magnetic leakage while ensuring sufficient mechanical strength, thereby reducing or eliminating the need for reinforcing structures inside or outside the rotor core 50 to save production costs.

[0046] Please refer to Figures 2-3The rotor assembly includes a first rotor lamination 10, which has a first connecting structure 20. The first lamination structure 100 and the second lamination structure 101 within the first rotor lamination 10 are separated from each other. Thus, the first rotor lamination 10 only has the first connecting structure 20, which is positioned in the gap between two adjacent second lamination structures 101 and seals the gap. Since the first connecting structure 20 is made of a non-magnetic material, it can completely cut off the path of magnetic flux leakage from the gap, allowing the magnetic flux generated by the magnet 60 to be guided into the air gap, thereby improving the motor's operating performance.

[0047] As those skilled in the art will understand, the primary function of the first connecting structure 20 is to cut off the leakage magnetic path and assist in fixing the magnet 60 to prevent it from shifting during the rotation of the rotor core 50, thus affecting the smooth operation of the motor. Therefore, theoretically, the first connecting structure 20 only needs to seal the gap and extend towards the magnet 60 to restrict its movement within the receiving groove 102; it does not need to connect the first lamination structure 100 and the second lamination structure 101. However, considering that the magnetic isolation bridge structure is omitted in this embodiment, resulting in a decrease in overall structural strength, as an optional embodiment, the first connecting structure 20 also serves to connect the first lamination structure 100 and the second lamination structure 101 during the gap sealing process. It should be noted, however, that the working principle of the first connecting structure 20 in this embodiment is completely different from that of the magnetic isolation bridge in the prior art.

[0048] Specifically, such as Figures 2-3 as well as Figure 9 As shown, the first lamination structure 100 is provided with a connecting portion 105, and the first connecting structure 20 has an abutting portion 106 that matches the connecting portion 105. The first connecting structure 20 is connected to the connecting portion 105 through the abutting portion 106. It should be noted that in this embodiment, at least two rotor laminations are coaxially stacked to form a rotor core 50. The first lamination structure 100 of the rotor laminations is coaxially stacked to form the inner core of the rotor core 50, and the second lamination structure 101 is coaxially stacked to form the magnetic pole core. The connecting portion 105 and the abutting portion 106 are connected to each other, realizing the connection between the inner core and the magnetic pole core of the rotor core 50, so that the formed rotor core 50 is connected as a whole.

[0049] exist Figure 2 and Figure 3 In the illustrated example, the connecting portion 105 includes a recess or a protrusion; the recess is radially recessed along the rotor lamination and forms an opening at the edge of the first lamination structure 100; or, the protrusion is radially outward protruding along the rotor lamination. Exemplary examples, such as... Figure 2As shown, the recess is arranged in an inverted T-shape, having a first large-diameter section (not shown in the figure) and a first small-diameter section (not shown in the figure). The first small-diameter section penetrates the edge of the first lamination structure 100 and forms an opening. The first large-diameter section is located on the side of the first small-diameter section away from the opening and communicates with the first small-diameter section. The first connecting structure 20 is filled into the recess by injection molding or potting to form an abutment portion 106 that fits the recess. Similarly, as... Figure 3 As shown, the protrusion is T-shaped and has a second large diameter section (not shown in the figure) and a second small diameter section (not shown in the figure). The second small diameter section protrudes outward from the edge of the first stamping structure 100. The second large diameter section is located on the side of the second small diameter section away from the first stamping structure and communicates with the second small diameter section. The first connecting structure 20 is provided at least on the edge of the protrusion in the form of injection molding or potting to form an abutment portion 106 that is adapted to the protrusion.

[0050] In some other embodiments, the recesses or protrusions may also be in other shapes, such as rectangles, triangles, trapezoids, arcs, or other irregular shapes. This embodiment does not limit this. Those skilled in the art should understand that the first connecting structure 20 is formed from a non-magnetic material through injection molding or potting. Compared to the first lamination structure 100 and the second lamination structure 101, the first connecting structure 20 is weaker. Therefore, the first connecting structure 20 only serves a connecting function, while the second connecting structure 30 and the aforementioned rivets are the main components that increase the structural strength of the rotor core 50. This is inconsistent with the function of the magnetic isolation bridge in the prior art.

[0051] like Figure 4 As shown, the rotor assembly includes a second rotor lamination 11, and the second connecting structure 30 includes a first connecting substructure 301. The second rotor lamination 11 has the first connecting substructure 301. The first connecting substructure 301 connects the first lamination structure 100 in the second rotor lamination 11 and two adjacent second lamination structures 101. Unlike the first rotor lamination 10, the second rotor lamination 11 only has the first connecting substructure 301 in the second connecting structure 30, and the material of the first connecting substructure 301 is the same as that of the first lamination structure 100 and the second lamination structure 101, allowing it to be integrally formed with the first lamination structure 100 and the second lamination structure 101, further improving the connection strength between the first lamination structure 100 and the second lamination structure 101. Simultaneously, the first connecting substructure 301 is positioned in the same place as the first connecting structure 20 in the first rotor lamination 10, both capable of connecting the first lamination structure 100 and two adjacent second lamination structures 101.

[0052] Furthermore, the receiving slot 102 has two receiving sub-slots 103, each receiving sub-slot 103 having a magnet 60 disposed therein; the receiving sub-slot 103 has a connecting end and an extension end disposed opposite to each other, the connecting end of the two receiving sub-slots 103 being interconnected, and the extension ends being disposed in different directions toward the edge of the rotor lamination; the first connecting substructure 301 is connected at the extension end to the first lamination structure 100 and two adjacent second lamination structures 101 respectively.

[0053] In this embodiment, the receiving groove 102 is V-shaped. The V-shaped receiving groove 102 can better concentrate magnetic flux, enhance the magnetic field density in the air gap, and improve torque output. At the same time, by reasonably designing the included angle between the V-shaped receiving grooves 102, the reluctance torque can be fully utilized, thereby improving the torque density and efficiency of the electrode. Of course, in some other embodiments, the receiving groove 102 can also be straight.

[0054] Specifically, both of the aforementioned accommodating sub-slots 103 are straight slots, and each of the two accommodating sub-slots 103 is provided with a magnet 60. The connecting ends of the two accommodating sub-slots 103 are interconnected, and a protrusion 104 is provided at the connection point of the two accommodating sub-slots 103. The protrusion 104 can prevent the magnets 60 respectively provided in the two accommodating sub-slots 103 from colliding with each other, thereby improving the service life of the magnets 60 and further improving the stability of the motor during operation.

[0055] Please refer to Figures 2-4 as well as Figures 6-7 The rotor core 50 has a first end plate 40 and a second end plate 41 respectively arranged along its own axial direction. The rotor core 50 also has a first stacked section 500, a second stacked section 501, and a third stacked section 502 along its own axial direction. The first stacked section 500 is located near the first end plate 40, the second stacked section 501 is located near the second end plate 41, and the third stacked section 502 is located between the first stacked section 500 and the second stacked section 501. The first rotor lamination 10 is disposed in the third stacked section 502, and the second rotor lamination 11 is disposed in the first stacked section 500 and the second stacked section 501. In this embodiment, the first rotor lamination 10 has the best magnetic shielding performance, while the second rotor lamination 11 has the best structural strength. The combination of the two allows the stacked rotor core 50 to achieve both magnetic shielding performance and structural strength.

[0056] In this embodiment, the second rotor lamination 11 is disposed on the first stacking section 500 and the second stacking section 501 near the end plate, while the first rotor lamination 10 is disposed on the third stacking section 502 located in the middle, so that the structural strength of the two ends of the rotor core 50 along the axial direction is better than that of the middle part. Those skilled in the art will understand that during rotation, the mechanical constraint force and the stress generated by the constraint on the two ends of the rotor core 50 are generally greater than those in the middle region. Therefore, placing the second rotor lamination 11 at both ends of the rotor core 50 can improve the structural strength of the two ends to cope with the aforementioned constraint force and stress.

[0057] Preferably, the first stacking section 500 is provided with n1 second rotor laminations 11, the second stacking section 501 is provided with n2 second rotor laminations 11, and the third stacking section 502 is provided with n3 first rotor laminations 10. Then 5≤n1≤10, 5≤n2≤10, and 90≤n3≤118, so that the first stacking section 500 and the second stacking section 501 of the rotor core 50 have certain axial dimensions, further ensuring structural strength.

[0058] As an example, the axial dimension of the first rotor lamination 10 and the second rotor lamination 11 is 0.35 mm, and the axial dimension of the entire rotor core 50 is between 35 mm and 45 mm. Those skilled in the art will understand that as the axial dimension of the rotor core 50 increases, the motor's output torque, back electromotive force constant Ke, and torque constant Kt all increase, enabling it to provide greater torque at the same diameter. However, the increase in the axial dimension of the rotor core 50 also increases the length of the winding wires, leading to increased resistance, which in turn increases copper losses, resulting in more severe heating under the same current, and also increases inductance. Therefore, it is necessary to control the axial dimension of the rotor core 50 within a reasonable range based on actual needs. In some other embodiments, the number of rotor laminations in the first stacking section 500, the second stacking section 501, and the third stacking section 502 can also be other reasonable numbers, which are not limited in this embodiment.

[0059] As an optional embodiment, the arrangement of the first rotor lamination 10 and the second rotor lamination 11 can also be such that the first rotor lamination 10 and the second rotor lamination 11 are arranged alternately along the axial direction, or the first rotor lamination 10 and the second rotor lamination 11 can be arranged irregularly, but it is necessary to ensure that the number of the first rotor lamination 10 is greater than or equal to the number of the second rotor lamination 11, so as to balance magnetic shielding performance and structural strength.

[0060] In one embodiment, the axial dimension of the first rotor core is 35 mm, and it is formed by stacking 100 conventional rotor laminations (i.e., with a conventional magnetic bridge structure); the axial dimension of the second rotor core is also 35 mm, and it is formed by stacking 90 first rotor laminations 10 and 10 second rotor laminations 11, wherein 5 second rotor laminations 11 are respectively provided at both ends of the 90 first rotor laminations 10 along the axial direction. Under the condition that all other parameters are exactly the same, the back electromotive force constant Ke of the motor equipped with the first rotor core is 55 V / K rpm, while the back electromotive force constant Ke of the motor equipped with the second rotor core increases to 60 V / K rpm, an increase of 9%.

[0061] As those skilled in the art will understand, the back electromotive force constant Ke refers to the linear induced electromotive force generated in the armature winding at a unit angular velocity (or unit rotational speed) when the armature winding of the motor is open-circuited. It characterizes the motor's ability to convert rotational speed into back electromotive force. The value of the back electromotive force constant Ke is directly related to the winding coefficient, number of turns, air gap magnetic flux density (referring to the magnetic induction intensity passing through a unit area perpendicular to the direction of magnetic field lines in the air gap), and rotor core size. Under the condition that other parameters are exactly the same, the air gap magnetic flux density in the second rotor core is significantly greater than that in the first rotor core, that is, the magnetic induction intensity of the air gap in the second rotor core is greater than that in the first rotor core. Thus, using the second rotor core can effectively reduce leakage flux. That is, in this embodiment, the combination of the first rotor lamination 10 and the second rotor lamination 11 can effectively reduce leakage flux while ensuring the structural strength of the rotor core 50.

[0062] like Figure 5As shown, the rotor assembly includes a third rotor lamination 12, and the second connecting structure 30 has a second connecting substructure 302. The third rotor lamination 12 has a first connecting structure 20 and a second connecting substructure 302, which connects the first lamination structure 100 and the second lamination structure 101 in the third rotor lamination 12, respectively. Unlike the first rotor lamination 10 and the second rotor lamination 11, the third rotor lamination 12 is provided with the second connecting substructure 302 in both the first connecting structure 20 and the second connecting structure 30, and the material of the second connecting substructure 302 is the same as that of the first lamination structure 100 and the second lamination structure 101, allowing it to be integrally formed with the first lamination structure 100 and the second lamination structure 101. It should be noted that the size of the second connecting substructure 302 is smaller than the size of the first connecting substructure 301; therefore, the structural strength of the third rotor lamination 12 is not as strong as that of the second rotor lamination 11. However, when the third rotor lamination 12 is stacked to form the rotor core 50, it does not need to be combined with the first rotor lamination 10 and the second rotor lamination 11. The rotor laminations with the same structure can reduce the forming difficulty of the stacking process. Moreover, the rotor core 50 formed by stacking the third rotor lamination 12 also has a certain structural strength, which can reduce or eliminate the reinforcing structures set inside or outside the rotor core 50, thereby achieving a balance between motor performance and economy.

[0063] Furthermore, the receiving slot 102 has two receiving sub-slots 103, each receiving sub-slot 103 having a magnet 60 disposed therein; the receiving sub-slots 103 have a connecting end and an extension end disposed opposite to each other, the connecting ends of the two receiving sub-slots 103 are close to each other, and the extension ends penetrate the edge of the rotor lamination in different directions and are respectively connected to the outside; the second connecting sub-structure 302 is disposed at the connecting end to isolate the two receiving sub-slots 103 from each other.

[0064] In this embodiment, the configuration of the first connecting structure 20 can be referred to the description in the first rotor lamination 10, and will not be repeated here. The second connecting substructure 302 replaces the protrusion 104 in the second rotor lamination 11. The protrusion 104 is used to separate the two magnets 60 from each other, but the two receiving sub-slots 103 are interconnected. The second connecting substructure 302 directly connects the first lamination structure 100 and the second lamination structure 101 at the connecting end of the receiving sub-slots 103 to completely separate the two receiving sub-slots 103.

[0065] Please refer to Figure 5 as well as Figure 8The rotor core 50 is formed by coaxially stacking at least two third rotor laminations 12. Since the third rotor lamination 12 is provided with both the first lamination structure 100 and the second lamination structure 101, the rotor core 50 that balances magnetic shielding performance and structural strength can be formed by using the third rotor lamination 12 alone, without the need to combine it with the first rotor lamination 10 and the second rotor lamination 11.

[0066] As will be understood by those skilled in the art, the rotor core 50 can be coaxially stacked from multiple rotor laminations using a lamination process. Specifically, the aforementioned lamination processes include hot lamination, cold lamination, adhesive lamination, and cast aluminum lamination. Hot lamination involves heating the lamination assembly and then fitting it onto the shaft, followed by cooling and shaping under pressure; this process can be used for forming shielded motors or slender rotors with high interference fit requirements. Cold lamination, also known as snap-fitting, involves interlocking the protrusions on the laminations under pressure; this process can be used for forming drive motors for new energy vehicles. Adhesive lamination involves coating or placing adhesive between the laminations and then heating and pressing to cure; this process can be used for forming high-performance motors with high insulation and iron loss requirements. Cast aluminum lamination involves placing the laminations into a mold and pouring molten aluminum to form guide bars and end rings; this process can be used for forming traction motors for rail transit.

[0067] Please refer to Figure 1 and Figure 10 This application also provides an electric motor, including a stator assembly and a rotor assembly as described above. The beneficial effects of the rotor assembly on this motor are described above and will not be repeated here.

[0068] Optionally, the motor can be a permanent magnet motor. The stator assembly can include a stator core 70 and a stator winding. The stator core 70 is disposed around the rotor core 50, and the stator winding is disposed in the stator slots of the stator core 70. When the stator winding is energized, it will form a rotating magnetic field in the internal space. Under the action of the rotating magnetic field, the rotor core 50 rotates together with the permanent magnet. The attraction and repulsion between the permanent magnet magnetic field generated by the permanent magnet and the rotating magnetic field together maintain the rotation of the motor.

[0069] like Figure 10As shown, the stator assembly includes a stator core 70, and the rotor assembly includes a rotor core 50. The rotor core 50 and the stator core 70 are coaxially arranged, with the stator core 70 located around the rotor core 50. The distance between the outer contour of the rotor core 50 and the inner contour of the stator core 70 is L1. The opening size of the recess in the rotor assembly is L2, and the maximum distance between the recess in the rotor assembly along the radial direction of the rotor lamination and the inner contour of the stator core 70 is L3. Therefore, L1 < L2 and L1 < L3. Thus, the size of the connecting portion 105 on the first lamination structure 100 is larger than the air gap between the stator core 70 and the rotor core 50. This facilitates assembly and processing. Furthermore, this application uses the first connecting structure 20 to fill around the connecting portion 105 and seal the gap between the receiving groove 102 and the outside, allowing the magnetic flux generated by the magnet 60 to be concentrated and guided into the air gap, increasing the magnetic field strength in the air gap and further improving the performance of the motor.

[0070] In this embodiment, the recessed opening size L2 can refer to the length of the opening formed by the first small diameter segment at the edge of the first lamination structure 100 in a direction perpendicular to the radial direction of the first lamination structure 100.

[0071] In another embodiment, this application also provides a compressor including the motor described above. The beneficial effects of this compressor due to the rotor assembly are described above and will not be repeated here.

[0072] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications or equivalent substitutions made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A rotor assembly, characterized in that, include: At least two stacked rotor laminations; each rotor lamination has a first lamination structure and at least two second lamination structures, the at least two second lamination structures being arranged circumferentially around the first lamination structure, and a gap being between adjacent second lamination structures; a receiving groove for accommodating a magnet is formed between the first lamination structure and the second lamination structure, the receiving groove communicating with the gap; At least one of the rotor laminations has a first connecting structure disposed between adjacent second lamination structures and sealing the gap; the first connecting structure is made of a non-magnetic material.

2. The rotor assembly according to claim 1, characterized in that, At least one of the rotor laminations has a second connecting structure, which connects the first lamination structure and the second lamination structure respectively.

3. The rotor assembly according to claim 2, characterized in that, The rotor assembly includes a rotor core, which is formed by at least two rotor laminations stacked coaxially. Wherein, the number of rotor laminations with the first connection structure is N, and the number of rotor laminations with the second connection structure is n, then N≥n.

4. The rotor assembly according to claim 2, characterized in that, The rotor assembly includes a first rotor lamination having the first connection structure, and the first lamination structure and the second lamination structure in the first rotor lamination are separated from each other.

5. The rotor assembly according to claim 4, characterized in that, The rotor assembly includes a second rotor lamination, and the second connection structure includes a first connection substructure, wherein the second rotor lamination has the first connection substructure. The first connecting substructure connects the first lamination structure in the second rotor lamination and two adjacent second lamination structures respectively.

6. The rotor assembly according to claim 5, characterized in that, The receiving slot has two receiving sub-slots, and each receiving sub-slot is provided with one of the magnets; The receiving sub-slot has a connecting end and an extension end arranged opposite to each other, the connecting ends of the two receiving sub-slots are connected to each other, and the extension ends are respectively arranged in different directions toward the edge of the rotor lamination. The first connecting substructure is connected at the extension end to the first lamination structure and two adjacent second lamination structures respectively.

7. The rotor assembly according to claim 5, characterized in that, The rotor assembly includes a rotor core, which is formed by at least two rotor laminations stacked coaxially. The rotor core is provided with a first end plate and a second end plate at both ends along its own axial direction, and the rotor core has a first stacked section, a second stacked section and a third stacked section along its own axial direction. The first stacking segment is disposed close to the first end plate, the second stacking segment is disposed close to the second end plate, and the third stacking segment is located between the first stacking segment and the second stacking segment; The first rotor lamination is disposed in the third stacking section, and the second rotor lamination is disposed in both the first stacking section and the second stacking section.

8. The rotor assembly according to claim 7, characterized in that, The first stacking section is provided with n1 second rotor laminations, the second stacking section is provided with n2 second rotor laminations, and the third stacking section is provided with n3 first rotor laminations, then 5≤n1≤10, 5≤n2≤10, and 90≤n3≤118.

9. The rotor assembly according to claim 2, characterized in that, The rotor assembly includes a third rotor lamination, and the second connecting structure has a second connecting substructure. The third rotor lamination has the first connecting structure and the second connecting substructure, and the second connecting substructure connects the first lamination structure and the second lamination structure in the third rotor lamination respectively.

10. The rotor assembly according to claim 9, characterized in that, The receiving slot has two receiving sub-slots, and each receiving sub-slot is provided with one of the magnets; The receiving sub-slot has a connecting end and an extension end arranged opposite to each other. The connecting ends of the two receiving sub-slots are close to each other, and the extension ends pass through the edge of the rotor lamination in different directions and are respectively connected to the outside. The second connecting substructure is disposed at the connecting end so that the two receiving sub-slots are isolated from each other.

11. The rotor assembly according to claim 9, characterized in that, The rotor assembly includes a rotor core, which is formed by coaxially stacking at least two of the third rotor laminations.

12. The rotor assembly according to claim 4 or 9, characterized in that, The first lamination structure is provided with a connecting part, and the first connecting structure has an abutting part that matches the connecting part. The first connecting structure is connected to the connecting part through the abutting part.

13. The rotor assembly according to claim 12, characterized in that, The connecting portion includes a recess or a protrusion; The recess is radially recessed along the rotor lamination and forms an opening at the edge of the first lamination structure; or... The protrusion protrudes radially outward along the rotor lamination.

14. An electric motor, characterized in that, It includes a stator assembly and a rotor assembly as described in any one of claims 1 to 13.

15. The motor according to claim 14, characterized in that, The stator assembly includes a stator core, and the rotor assembly includes a rotor core; The rotor core and the stator core are coaxially arranged, and the stator core is located around the rotor core. The distance between the outer contour of the rotor core and the inner contour of the stator core is L1. The opening size of the recess in the rotor assembly is L2. The maximum distance between the recess in the rotor assembly along the radial direction of the rotor lamination and the inner contour of the stator core is L3. Then L1 < L2 and L1 < L3.

16. A compressor, characterized in that, Includes the rotor assembly as described in any one of claims 1 to 13.

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