A stator-rotor assembly for an electric machine and an electric machine

Abstract

The utility model discloses a kind of stator-rotor assembly and motor for motor, it is related to motor field, including rotor core and the stator core being set around the rotor core, the rotor core includes several rotor lamination being stacked along the direction of axis, the rotor lamination is provided with motor shaft hole, buck riveting groove and the magnetic steel groove for embedding permanent magnet from inside to outside, the magnetic steel groove includes several pairs of groove position pairs being spaced apart along the circumference of the rotor lamination, the groove position pair includes first slot and second slot, every pair of the first slot and the second slot is spaced apart and the first included angle A is in the length direction of two, multiple buck riveting grooves are evenly distributed along the circumference of the rotor lamination and the second included angle B is between the length direction of adjacent buck riveting groove, wherein, the first included angle A is 100 °~120 °. Stator-rotor assembly in the utility model is small in size and has large torque.

Description

Technical Field

[0001] This utility model relates to the field of electric motors, specifically to a stator and rotor assembly for an electric motor and the motor itself. Background Technology

[0002] As a core component of modern power technology, the electric motor plays a crucial role in both industrial manufacturing and household appliances. Its basic structure consists of a stationary stator assembly and a rotatable rotor assembly. The rotor rotates synchronously via a built-in drive shaft, and this mechanical motion is ultimately converted into usable power output.

[0003] Torque is crucial in motors, serving as the core output indicator for converting electrical energy into mechanical energy and directly determining the dynamic performance of the mechanical system. Current high-torque motors generally rely on increasing the volume of the iron core to boost torque output, but this method increases material usage and manufacturing costs. Utility Model Content

[0004] This utility model aims to solve one of the technical problems in related technologies to a certain extent. Therefore, this utility model provides a stator and rotor assembly for an electric motor and the motor itself, which has the advantages of small size and high torque.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A stator-rotor assembly for an electric motor includes a rotor core and a stator core surrounding the rotor core. The rotor core includes a plurality of rotor laminations stacked along the axial direction. Each rotor lamination has a motor shaft hole, a rivet groove, and a magnet slot for embedding a permanent magnet, arranged from the inside out. The magnet slot includes a plurality of pairs of slot positions spaced apart along the circumference of the rotor lamination. Each pair of slot positions includes a first slot and a second slot. Each pair of first slots and second slots is spaced apart and has a first included angle A along their length direction. A plurality of rivet grooves are evenly distributed along the circumference of the rotor laminations and have a second included angle B between adjacent rivet grooves along their length direction. The first included angle A is 100° to 120°.

[0007] In this application, the magnet slot includes a first slot and a second slot arranged at an angle. By rationally setting the included angle between the first and second slots, the magnetic field distribution generated by the permanent magnet placed in the magnet slot can be optimized, allowing the magnetic field to form a more efficient magnetic circuit in the air gap between the rotor core and the stator core. This achieves higher magnetic flux density utilization with a smaller core size, thereby generating greater electromagnetic torque. The riveting slots connect multiple rotor laminations via riveting. The uniform distribution of multiple riveting slots along the circumference of the rotor laminations enhances mechanical stability. The second included angle B formed by adjacent riveting slots causes the stress directions to be distributed at an angle, creating a "stress diversion" effect and reducing stress concentration. Therefore, the core does not need to increase its volume to supplement its strength. In summary, this application improves magnetic circuit efficiency and structural stability through geometric optimization, reduces redundant materials, and lowers manufacturing costs.

[0008] Optionally, the stator core has a plurality of stator teeth that protrude radially inward and are spaced apart, and there is a third included angle C between the axes of adjacent stator teeth, wherein the third included angle C is 30°, the second included angle B is 36°, and at least one of the radial lines is collinear with the axis of the stator teeth and the radial center line of the rivet groove.

[0009] The included angle between adjacent stator tooth axes is 30°, meaning the stator core has 12 stator teeth along its circumference. Compared to the 8-tooth or 10-tooth stator cores in related technologies, the increased number of teeth in this application disperses the magnetic flux to more teeth, reducing the peak magnetic flux density. Consequently, the stator yoke (the area in the stator core that connects all the teeth) does not need to bear excessively high magnetic flux, allowing for a reduction in thickness and thus a smaller stator core volume.

[0010] Optionally, both the first slot and the second slot are constructed as elongated strips and have notches extending toward the rotor core axis on the side facing the rotor core axis.

[0011] The elongated first and second slots facilitate easy insertion or fixation of permanent magnets through the slot openings, improving installation efficiency, and the elongated slots are also easier to process. In addition, the notches on the first and second slots can reduce the demagnetizing effect of the stator teeth on the rotor permanent magnets by increasing the air gap magnetic resistance.

[0012] Optionally, the ratio of the diameter of the motor shaft hole to the diameter of the rotor core is 13:(38-44).

[0013] A smaller motor shaft bore and a larger rotor core reduce bending deformation of the motor shaft under high torque, significantly improving mechanical stability. The larger rotor core diameter not only enhances the rotor's moment of inertia and reduces vibration amplitude but also effectively suppresses the risk of resonance during operation.

[0014] Optionally, the number of slot pairs is 10 pairs, and the 10 slot pairs are evenly distributed along the circumference of the rotor lamination.

[0015] Ten pairs of slots are evenly distributed along the circumference of the rotor laminations, with an angle of 36° between two adjacent slot pairs. Each slot is equipped with a permanent magnet to form a periodic magnetic field distribution, reducing local magnetic saturation and improving the uniformity of air gap magnetic flux density.

[0016] Optionally, a through hole is provided between adjacent rivet grooves, and the width of the through hole gradually decreases in the direction close to the motor shaft hole.

[0017] The through holes are located between adjacent rivet slots, forming radial weight-reduction channels on the rotor laminations. The through holes significantly reduce the weight of the rotor core and also lower its rotational inertia, enabling the motor to accelerate and decelerate faster and respond more sensitively. They also help dissipate heat from the rotor core.

[0018] Optionally, the stator tooth includes a first arm and a second arm engaged with the first arm. The first arm extends radially along the stator core, and the second arm extends circumferentially along the stator core. A fourth included angle D is formed between the first arm and the second arm, and the fourth included angle D is 110° to 118°.

[0019] The radial extension of the first arm ensures efficient transfer of magnetic flux to the air gap, increasing torque density. The circumferential extension of the second arm makes the magnetic flux distribution more uniform, reducing the risk of local magnetic saturation. The angle between the first and second arms is 110° to 118°. This non-right-angle design reduces magnetic flux loss at the arm connection and avoids stress concentration problems that may occur with right-angle structures.

[0020] Optionally, there is a gap between the ends of adjacent second arms, the width of which is 3.0 to 3.8 mm.

[0021] In addition, this utility model also provides an electric motor, including a hollow housing and an end cap joined to one end of the housing, wherein a stator and rotor assembly is disposed inside the housing, and the stator and rotor assembly includes the aforementioned stator and rotor assembly for an electric motor.

[0022] The stator and rotor assemblies are integrated into the hollow housing of the motor, which significantly improves the overall performance of the motor and increases the torque of the motor without increasing the size of the motor.

[0023] Optionally, the outer surface of the housing is provided with a plurality of outwardly protruding first heat dissipation ribs, and the inner surface of the end cap is provided with inwardly protruding second heat dissipation ribs.

[0024] The first heat dissipation fin increases the heat dissipation area on the housing surface, thereby improving heat dissipation efficiency. A second heat dissipation fin is also provided inside the end cover to further enhance the motor's heat dissipation effect.

[0025] The motor provided by this utility model has a similar reasoning process to the aforementioned stator and rotor assembly for motors, and will not be repeated here.

[0026] These features and advantages of this utility model will be disclosed in detail in the following specific embodiments and accompanying drawings. The preferred embodiments or means of this utility model will be shown in detail in conjunction with the accompanying drawings, but are not intended to limit the technical solutions of this utility model. In addition, each of these features, elements and components appearing in the following text and drawings is multiple and is labeled with different symbols or numbers for convenience, but all represent parts with the same or similar structure or function. Attached Figure Description

[0027] The present invention will be further described below with reference to the accompanying drawings:

[0028] Figure 1 This is a schematic diagram of the stator and rotor assembly in this utility model;

[0029] Figure 2 This is a schematic diagram of the rotor lamination structure in this utility model;

[0030] Figure 3 This is a partial structural diagram of a rotor lamination;

[0031] Figure 4 This is a schematic diagram of the stator core structure;

[0032] Figure 5 This is a partial structural diagram of the stator core.

[0033] Figure 6 This is a schematic diagram of the shell structure;

[0034] Figure 7 This is a schematic diagram of the end cap structure.

[0035] Among them, 1. Rotor lamination; 11. Motor shaft hole; 12. Rivet groove; 13. Magnet slot; 131. First slot; 132. Second slot; 133. Notch; 14. Through hole; 2. Stator core; 21. Stator tooth; 211. First support arm; 212. Second support arm; 22. Stator winding; 3. Housing; 31. First heat dissipation fin; 4. End cover; 41. Second heat dissipation fin. Detailed Implementation

[0036] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described are intended to explain this utility model and should not be construed as limiting it.

[0037] The terms "an embodiment," "example," or "trademark" used in this specification refer to a particular feature, structure, or characteristic described in connection with the embodiment itself that may be included in at least one embodiment disclosed in this patent. The phrase "in an embodiment" appearing in various places throughout the specification does not necessarily refer to the same embodiment.

[0038] In related technologies, the magnetic steel slots used to place permanent magnets are mostly evenly distributed along the circumference of the iron core. This structure leads to severe leakage of magnetic lines of force at the edge of the air gap. In addition, related technologies generally compensate for the loss of magnetic flux density by increasing the diameter of the iron core, which increases the manufacturing cost of the stator and rotor assembly.

[0039] Example:

[0040] like Figures 1 to 3 As shown, this embodiment provides a stator-rotor assembly for an electric motor, including a rotor core and a stator core 2 surrounding the rotor core. The rotor core includes a plurality of rotor laminations 1 stacked along the axial direction. The rotor laminations 1 are provided with motor shaft holes 11, rivet grooves 12, and magnet slots 13 for embedding permanent magnets from the inside out. The magnet slots 13 include a plurality of pairs of slot positions spaced apart along the circumference of the rotor laminations 1. The slot pairs include first slots 131 and second slots 132 spaced apart. The length direction of the first slots 131 and the second slots 132 has a first included angle A. The plurality of rivet grooves 12 are evenly distributed along the circumference of the rotor laminations 1 and the length direction of adjacent rivet grooves 12 has a second included angle B, wherein the first included angle A is 100° to 120°.

[0041] In this embodiment, the magnetic slot 13 includes several pairs of slots for placing permanent magnets. Each pair of slots includes a first slot 131 and a second slot 132 that are inclined to each other, i.e., there is an angle between the first slot 131 and the second slot 132. This structure forces the magnetic flux path to be curved in the rotor core, rather than the radial propagation of traditional straight slots, thus extending the effective path length of the magnetic flux in the core, reducing magnetic reluctance, and thereby improving magnetic permeability. In other words, the first slot 131 and the second slot 132 in this embodiment can optimize the magnetic field distribution generated by the permanent magnets placed in the slots, so that the magnetic field forms a more efficient magnetic circuit in the air gap between the rotor core and the stator core 2, thereby achieving a higher magnetic flux density utilization rate with a smaller core size, and thus generating a larger electromagnetic torque. When the angle is greater than 120°, it will cause the permanent magnets to be arranged too dispersedly, the coupling between magnetic poles to be weakened, and the magnetic circuit path to be distorted. When the angle is less than 100°, it will cause the permanent magnets to be arranged too densely, and the local magnetic flux density to be too high. Preferably, the first included angle A between the length direction of the first slot 131 and the length direction of the second slot 132 is 110°. The applicant has found that this angle adjusts the magnetic pole distribution, causing specific harmonics (such as the 5th and 7th harmonics) in the air gap magnetic flux to cancel each other out, thus reducing torque pulsation. Specifically, the length direction of the first slot 131 refers to the extension direction of the longer side of the first slot 131, and the length direction of the second slot 132 refers to the extension direction of the longer side of the second slot 132. In other embodiments, the first included angle A can also be other values ​​such as 112° or 113°. Furthermore, in this embodiment, the first slot 131 and the second slot 132 are spaced apart to reduce magnetic flux short circuits.

[0042] like Figure 4 As shown, the stator core 2 has a plurality of stator teeth 21 that protrude radially inward and are spaced apart. There is a third included angle C between the axes of adjacent stator teeth 21. The third included angle C is 30° and the second included angle B is 36°. At least one of the radial lines is collinear with the axis of the stator tooth 21 and the radial center line of the rivet groove 12.

[0043] In this embodiment, the stator core 2 has an inner stator tooth 21 structure. Multiple stator teeth 21 are disposed on the inner surface of the stator core 2 and protrude inwards along the radial direction of the stator core 2. Adjacent teeth form tooth grooves, and the included angle between the axes of adjacent teeth is 30°. That is, 12 teeth are evenly distributed circumferentially along the inner surface of the stator core 2, forming 12 stator tooth grooves. In other embodiments, the stator core 2 can also have an outer stator tooth 21 structure. In this case, the stator teeth 21 are distributed on the outer surface of the stator core 2 and protrude outwards along the radial direction of the stator core 2. Specifically, the outer diameter of the stator core 2 is 120 mm, the inner diameter of the stator core 2 is 83.4 mm, and the stator tooth grooves extending circumferentially along the sidewalls of the stator core 2 are formed on the same circumferential surface with a diameter of 111.8 mm.

[0044] Both the first slot 131 and the second slot 132 are constructed in a long strip shape and have a notch 133 extending toward the rotor core axis on the side facing the rotor core axis.

[0045] In this embodiment, both the first slot 131 and the second slot 132 are designed as elongated strips and extend circumferentially along the stator core 2. A rectangular notch 133 extending towards the rotor core axis is provided on the side of the slot near the rotor core axis. The notch 133 can guide the magnetic flux path, reduce local magnetic saturation, and improve motor efficiency. In other embodiments, the notch 133 may also be semi-circular or trapezoidal in shape.

[0046] The ratio of the diameter of the motor shaft hole 11 to the diameter of the rotor core is 13:(38~44).

[0047] In this embodiment, the shaft hole is located at the center of the rotor core and is used to install the motor shaft to ensure coaxiality. Since the outer circumference of the rotor core is not on the same circumference, meaning the diameter length of the rotor core is not consistent at different points, the preferred ratio of the motor shaft hole 11 to the rotor core diameter is 13:(38-44). For example, when the motor shaft hole diameter is 26mm, the outer circumference diameter of the rotor core can be 76mm, 82mm, 88mm, etc. This diameter ratio enhances the rotor's rotational inertia, reduces vibration amplitude, and significantly improves mechanical stability. Especially when the diameter ratio is 13:41, noise, reliability, and lifespan parameters are even better.

[0048] There are 10 pairs of slots, and the 10 pairs of slots are evenly distributed along the circumference of the rotor laminations.

[0049] In this embodiment, each pair of slots can be defined as one electrode, that is, the rotor core has 10 electrodes. As can be seen from the above, the stator core 2 has 12 slots, so the slot-to-pole ratio is 1.2 (close to 1), which can effectively reduce the cogging torque and avoid torque fluctuations caused by the mismatch between the number of poles and the number of slots.

[0050] A through hole 14 is provided between adjacent rivet grooves 12, and the width of the through hole 14 gradually decreases in the direction close to the motor shaft hole 11.

[0051] In this embodiment, the riveting groove 12 is a groove used to connect multiple rotor laminations 1, and a firm connection between the rotor laminations 1 can be achieved through riveting. Through holes 14 are provided between adjacent riveting grooves 12, and the number of through holes 14 is the same as the number of riveting grooves 12 (e.g., 10 pairs of riveting grooves 12 correspond to 10 through holes 14), ensuring the circumferential symmetry of the rotor. The through holes 14 significantly reduce the weight of the rotor core and also reduce the rotational inertia of the rotor core, enabling the motor to accelerate and decelerate faster and respond more sensitively. Simultaneously, the through holes 14 can be used to dissipate heat from the rotor core, improving the stability of the rotor core.

[0052] like Figure 5As shown, the stator tooth 21 includes a first arm 211 and a second arm 212 engaged with the first arm 211. The first arm 211 extends radially along the stator core 2, and the second arm 212 extends circumferentially along the stator core 2. A fourth included angle D is formed between the first arm 211 and the second arm 212, and the fourth included angle D is 110° to 118°.

[0053] In this embodiment, the first arm 211 and the second arm 212 are integrally formed for ease of processing. The first arm 211 is straight, while the second arm 212 is arc-shaped. The fourth included angle refers to the angle between the tangent of the arc edge of the second arm 212 closest to the first arm 211 and the side edge of the first arm 211 extending radially along the stator core 2. When the fourth included angle D is too small (less than 110°), it will cause compression of the tooth space and obstruction of airflow. When the fourth included angle D is too large (greater than 118°), the tooth space will be excessively expanded, reducing the winding arrangement space. Preferably, the fourth included angle D is 113°.

[0054] The stator core 2 also includes a stator winding 22, which is wound around a first support arm 211. In this embodiment, the stator winding 22 is wound around the first support arm 211 and accommodated in a slot formed between adjacent stator teeth 21. The first support arm 211 extends radially along the stator core 2 to serve as a load-bearing structure for the stator winding 22, ensuring tight coupling between the stator winding 22 and the stator core 2. The two ends of the second support arm 212 protrude from the first support arm 211 to prevent the stator winding 22 from detaching from the first support arm 211 radially along the stator core 2.

[0055] A gap exists between the ends of adjacent second arms 212, with a width of 3.0–3.8 mm. In this embodiment, the gap between adjacent second arms 212 is controlled at 3.0–3.8 mm to balance the magnetic circuit distribution, mechanical stress, and heat dissipation performance of the rotor core. If the gap between adjacent second arms 212 is too small, magnetic saturation and stress concentration are likely to occur; if the gap is too large, the rotor structural strength and torque output capability are weakened. Preferably, the gap between adjacent second arms 212 is 3.4 mm to optimize torque density and noise level while balancing magnetic circuit efficiency, mechanical stability, and heat dissipation capability. It should be noted that the end of the second arm 212 refers to the end region of the second arm 212 extending circumferentially along the stator core 2.

[0056] This embodiment also provides an electric motor, including a hollow housing 3 and an end cover 4 joined to one end of the housing 3. A stator and rotor assembly is disposed inside the housing 3, and the stator and rotor assembly includes the aforementioned stator and rotor assembly for an electric motor.

[0057] In this embodiment, the hollow housing 3 has an opening at one end, and the end cover 4 is detachably attached to the opening to seal the internal space of the housing 3 and the stator and rotor assembly located inside the housing 3. The end cover 4 can protect the stator and rotor assembly inside the housing 3 and facilitate maintenance.

[0058] like Figure 6 As shown, the outer surface of the housing 3 is provided with several outwardly protruding first heat dissipation fins 31, such as... Figure 7 As shown, the inner surface of the end cap 4 is provided with an inwardly protruding second heat dissipation rib 41.

[0059] The first heat dissipation fin 31 and the second heat dissipation fin 41 can increase the heat dissipation area and increase the surface heat dissipation fluid velocity. In addition, the first heat dissipation fin 31 and the second heat dissipation fin 41 can work together to form a heat dissipation channel between the shell 3 and the end cover 4.

[0060] The above are merely specific embodiments of this utility model, but the scope of protection of this utility model is not limited thereto. Those skilled in the art should understand that this utility model includes, but is not limited to, the contents described in the accompanying drawings and the specific embodiments above. Any modifications that do not depart from the functional and structural principles of this utility model will be included within the scope of the claims.

Claims

1. A stator-rotor assembly for an electric motor, comprising a rotor core and a stator core (2) surrounding the rotor core, wherein the rotor core comprises a plurality of rotor laminations (1) stacked along the axial direction, and the rotor laminations (1) are provided with motor shaft holes (11), rivet grooves (12), and magnet slots (13) for embedding permanent magnets from the inside out, characterized in that, The magnetic slot (13) includes several pairs of slots spaced apart along the circumference of the rotor lamination (1). Each slot pair includes a first slot (131) and a second slot (132) spaced apart. The length direction of the first slot (131) and the second slot (132) has a first included angle A. A plurality of the rivet slots (12) are evenly distributed along the circumference of the rotor lamination (1) and there is a second included angle B between adjacent rivet slots (12) along their length direction. The first included angle A is 100°~120°.

2. The stator and rotor assembly for an electric motor according to claim 1, characterized in that, The stator core (2) has a plurality of stator teeth (21) that protrude radially inward and are spaced apart. There is a third included angle C between the axes of adjacent stator teeth (21), the third included angle C is 30°, the second included angle B is 36°, and at least one of the radial lines is collinear with the axis of the stator teeth (21) and the radial center line of the rivet groove (12).

3. The stator and rotor assembly for an electric motor according to claim 1, characterized in that, Both the first slot (131) and the second slot (132) are constructed as elongated strips and have notches (133) extending toward the rotor core axis on the side facing the rotor core axis.

4. A stator and rotor assembly for an electric motor according to claim 1, characterized in that, The ratio of the diameter of the motor shaft hole (11) to the diameter of the rotor core is 13:(38~44).

5. A stator and rotor assembly for an electric motor according to claim 1, characterized in that, The number of slot pairs is 10 pairs, and the 10 slot pairs are evenly distributed along the circumference of the rotor lamination (1).

6. A stator and rotor assembly for an electric motor according to claim 1, characterized in that, A through hole (14) is provided between adjacent rivet grooves (12), and the width of the through hole (14) gradually decreases in the direction close to the motor shaft hole (11).

7. A stator and rotor assembly for an electric motor according to claim 2, characterized in that, The stator tooth (21) includes a first arm (211) and a second arm (212) engaged with the first arm (211). The first arm (211) extends radially along the stator core (2), and the second arm (212) extends circumferentially along the stator core (2). A fourth included angle D is formed between the first arm (211) and the second arm (212), and the fourth included angle D is 110°~118°.

8. A stator and rotor assembly for an electric motor according to claim 7, characterized in that, There is a gap between the ends of adjacent second arms (212), the gap having a width of 3.0~3.8mm.

9. An electric motor comprising a hollow housing (3) and an end cap (4) joined to one end of the housing, wherein a stator and rotor assembly is disposed within the housing, characterized in that, The stator and rotor assembly includes the stator and rotor assembly for an electric motor as described in any one of claims 1 to 8.

10. The motor according to claim 9, characterized in that, The outer surface of the housing (3) is provided with a plurality of outwardly protruding first heat dissipation ribs (31), and the inner surface of the end cap (4) is provided with inwardly protruding second heat dissipation ribs (41).

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