Stator core with trumpet-shaped slot opening and motor thereof

Abstract

The utility model relates to a stator core with a trumpet-shaped slot opening and a motor thereof. The stator iron core comprises a plurality of tooth bodies, wire embedding grooves and tooth yokes, the wire embedding grooves are located between two adjacent tooth bodies, the tooth bodies are connected through the tooth yokes, the wire embedding grooves are provided with groove opening structures at the outer circle of the stator iron core, each tooth body comprises a tooth crown and a tooth body, the tooth crown is located at the top of the tooth body, and blanking edges are arranged on the left side and the right side of the tooth crown. A slot opening structure of the stator iron core is formed by a gap formed by the blanking edges of every two adjacent tooth bodies, and the gap is gradually widened from the center side of the stator iron core to the outer side to form a horn mouth shape. The stator core slot opening structure has the beneficial effects that the stator core slot opening structure is simple and efficient in blanking process, the manufacturing cost is reduced, the service life of a blanking die is long, the replacement frequency and cost are reduced, the slot precision is high, the trumpet-shaped slot is strong in guiding effect, the passing of enameled wires is facilitated, the winding efficiency, the qualification rate and the slot fullness rate are improved, the motor performance is optimized, and the cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of hub motors, and particularly discloses a stator core with a trumpet-shaped slot opening and a motor thereof. Background Art

[0002] As the core power source of modern industry, electric motors are widely used in numerous fields, encompassing manufacturing, transportation, household appliances, and large-scale industrial equipment. Their performance and efficiency directly impact the operational quality and energy consumption of the entire industrial system, while their manufacturing process and manufacturing difficulty also have a direct impact on the development of the motor industry. As a key member of the motor family, the outer rotor motor, with its unique structure and performance characteristics, plays an indispensable role in specific fields.

[0003] The basic structure of an outer rotor motor consists of an outer rotor and an inner stator. Its operating principle is that the rotating magnetic field generated by the stator winding interacts with the rotor's magnetic field, thereby driving the outer rotor's rotation. Within this structure, the stator slot opening is crucial. It not only affects the distribution and transmission of the magnetic field but is also closely related to many performance indicators of the motor, especially the motor's manufacturing process, production efficiency, and product qualification rate.

[0004] Due to the structural characteristics of the outer rotor motor, the slots face outward, which is particularly common in hub motor applications. In addition, compared to the inner rotor motors that can reach speeds of thousands or tens of thousands of revolutions, most hub motors have speeds of less than 1,500 revolutions. This determines that the number of turns of the hub motor must be several times or even dozens of times that of the traditional inner rotor motor. As the number of slots and winding turns increases, the probability of frictional damage to the insulation layer of the enameled wire during the winding process increases significantly, resulting in a significant reduction in the winding qualification rate and winding efficiency of the outer rotor hub motor. Traditional inner rotor motors, due to the use of a full-sheet blanking process, generally adopt parallel slot structures or some specially designed irregular slot structures, mainly to solve or optimize the motor's cogging torque problem. When considering winding optimization, the slot opening size is increased to a certain extent. However, the slot opening has a significant impact on the motor's performance. For external rotor motors, their outer diameter is large and the number of slots is large. If the slot is too large, the slot shoulder size will inevitably become smaller, and the wire blocking effect will be greatly reduced, which will seriously affect the stator winding slot fill rate. At the same time, the traditional stator slot is directly punched and blanked. The punch pressure at the slot is high and it is easy to wear or break. The slot is prone to burrs, making forming difficult, and the mold needs frequent repairs. In addition, the production efficiency is low and the cost is high. Utility Model Content

[0005] In view of the deficiencies of the prior art, the utility model discloses a stator core with a trumpet-shaped slot opening, which has simple molding and low cost, and a motor thereof.

[0006] To achieve the above-mentioned purpose, the utility model discloses a stator core with a trumpet-shaped slot opening, and its technical solution is as follows:

[0007] A stator core with a trumpet-shaped slot opening comprises a plurality of tooth bodies, a wire-inserting slot and a tooth yoke, wherein the wire-inserting slot is located between two adjacent tooth bodies, the tooth bodies are connected to each other through the tooth yoke, and the wire-inserting slot is provided with a slot opening structure at the outer circumference of the stator core. Each tooth body comprises a tooth crown and a tooth body, the tooth crown is located at the top of the tooth body, and blanking edges are provided on the left and right sides of the tooth crown. The gap formed by the blanking edges of each two adjacent tooth bodies constitutes the slot opening structure of the stator core, and the gap gradually widens from the center side of the stator core to the outside to form a trumpet shape. The angle α formed by two adjacent blanking edges and the number N of wire-inserting slots of the stator core satisfy the following relationship:

[0008] α=(1+β)×360 / N

[0009] The value range of β is (-0.25~0.25), and α is the angle value.

[0010] The utility model provides a stator core with a trumpet-shaped slot opening, which also has the following auxiliary technical solutions:

[0011] Wherein, the ratio of the radial width of the tooth yoke to the tooth body width ranges from 0.5 to 1.

[0012] The number of wire-embedded slots of the stator core is 24 slots, 27 slots, 36 slots, 45 slots, 48 ​​slots, 54 slots, or 63 slots.

[0013] Wherein, the outer diameter of the stator core ranges from 100 to 300 mm.

[0014] Wherein, the slot opening height is 0.2-3 mm.

[0015] The utility model also discloses a hub motor, comprising the stator core with a trumpet-shaped slot opening in the above technical solution, and also comprising a rotor assembly and a motor shaft, wherein the rotor assembly is sleeved on the outside of the stator core, and the rotor assembly comprises a rim, a magnetic ring and a plurality of permanent magnets, wherein the rim is located on the outside of the magnetic ring and is fixedly connected to the magnetic ring, and the plurality of permanent magnets are arranged on the inner circumference of the magnetic ring, and support covers are provided on both axial sides of the motor, and the two support covers are fixedly connected to the axial end surfaces of the magnetic ring by screws respectively, and the centers of the two support covers are provided with bearings, and a shaft sleeve is welded to the center of the stator core, and the motor shaft passes through the two bearings and the inner hole of the shaft sleeve, and the motor shaft is fixed to the shaft sleeve by interference connection.

[0016] Compared with the existing technology, the utility model has the following advantages and positive effects:

[0017] The stator core with a trumpet-shaped slot opening, as described in the utility model, features a design scheme for the angles between the two punching edges of the slot opening, ensuring that each punching edge is parallel to the symmetric centerline of the tooth body within which it resides. This greatly simplifies the stator punching process. The slot opening is formed by punching and then rolling, and the punching punch has a sharp blade structure, making punching easy and clean, and forming simple, significantly improving punching efficiency. Furthermore, the dimensional accuracy of the slot opening is significantly improved, and the service life of the punching die is greatly extended. The service life of the die's slot punching structure is more than doubled, effectively reducing die costs. Furthermore, the finished stator core exhibits a unique structural characteristic of "wide outer opening and narrow inner opening," which is highly consistent with the principle of inserting wire from the outside to the inside during the winding process of an external rotor motor stator. This slot structure facilitates the smooth passage of enameled wire through the slot, and the trumpet-shaped opening provides an excellent guide, facilitating wire insertion and reducing the probability of scratching the enameled wire insulation layer. This improves the product qualification rate, increases the winding qualification rate, reduces scrap, and reduces production costs. In addition, the narrow inner opening is conducive to the wire blocking of the slot, which improves the slot fill rate of the winding and plays a positive role in improving the performance of the motor.

[0018] The in-wheel motor for driving an electric vehicle provided by the present invention has a stator core with many advantages: the stator core has a high slot fill rate, which can accommodate more windings in a limited space, thereby improving the power density of the motor; the winding qualification rate is high, which reduces the scrap rate caused by poor winding and reduces production costs; the motor has a strong overcurrent capacity, can withstand a large current in a short time, and improves the overload capacity of the motor; the cogging torque is small, which reduces the vibration and noise of the motor and improves the running stability of the motor; the motor has excellent performance and can provide reliable and efficient power for the electric vehicle.

[0019] The stator core slot opening structure of the utility model has a simple and efficient punching process, which reduces manufacturing costs, has a long service life of the punching die, reduces replacement frequency and cost, has high slot opening precision, and has a strong guiding effect of the trumpet-shaped slot, which is conducive to the passage of enameled wire, improves winding efficiency, qualified rate and slot fill rate, optimizes motor performance and reduces costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the stator core in the present utility model.

[0021] Figure 2 for Figure 1 Schematic diagram of the enlarged structure at point A in the middle.

[0022] Figure 3 This is the general assembly drawing of the motor of this utility model.

[0023] In the figure, 1. stator core; 2. rotor assembly; 3. support cover; 4. bearing; 5. oil seal; 6. motor shaft; 11. tooth body; 12. wire embedding groove; 13. tooth yoke; 14. slot opening structure; 15. bushing; 21. rim; 22 magnetic ring; 23. permanent magnet; 111. tooth crown; 112. tooth body; b. punching edges on the left and right sides of the tooth crown; h. slot opening height. DETAILED DESCRIPTION

[0024] The following describes in detail the specific embodiments of the present invention and further illustrates the technical solution of the present invention in conjunction with the accompanying drawings. It should be noted that these descriptions are intended to help those skilled in the art better understand the present invention and do not constitute any limitation on the scope of protection of the present invention.

[0025] Example 1:

[0026] See also Figures 1 to 3 As shown, this embodiment provides a 10-inch in-wheel motor for electric vehicles, comprising a rotor assembly 2 and a stator core 1. The rotor assembly 2 is sleeved onto the outside of the stator core 1. The rotor assembly 2 includes a rim 21, a magnetic ring 22, and several permanent magnets 23. The rim 21 is located outside the magnetic ring 22 and is fixedly connected to the magnetic ring 22. The tire size of the rim 21 meets the relevant standards for motorcycle rims. Several permanent magnets 23 are evenly distributed circumferentially and mounted on the inside of the magnetic ring 22. Support caps 3 are provided on both axial sides of the motor. The two support caps 3 are fixedly connected to the axial end surfaces of the magnetic ring 22 by screws. A bearing 4 and an oil seal 5 are interference-fitted at the center of each support cap 3. The oil seal 5 is located outside the bearing 4. A sleeve 15 is welded to the center of the stator core 1. The motor shaft 6 passes through the inner holes of the two bearings 4, the two oil seals 5, and the sleeve 15, and is fixed to the sleeve 15 by an interference fit. The motor shaft 6 is provided with a wire outlet hole, and the external lead wire enters and exits the inner and outer sides of the motor through the wire outlet hole.

[0027] In the above technical solution: the stator core includes a plurality of tooth bodies 11, wire embedding grooves 12 and a tooth yoke 13. The wire embedding grooves 12 are located between two adjacent tooth bodies 11. The tooth bodies 11 are connected to each other through the tooth yoke 13. The wire embedding grooves 12 are provided with a slot opening structure at the outer circle of the stator core 1. Each tooth body 11 includes a tooth crown 111 and a tooth body 112. The tooth crown 111 is located at the top of the tooth body 112. The left and right sides of the tooth crown 111 are provided with blanking edges b. The gap formed by the blanking edges b of each two adjacent tooth bodies 11 constitutes the slot opening structure of the stator core 1. The gap gradually widens from the center side of the stator core 1 to the outside to form a trumpet shape. The angle α formed by each two adjacent blanking edges b and the number N of wire embedding grooves of the stator core 1 satisfy the following relationship:

[0028] α=(1+β)×360 / N

[0029] The value range of β is (-0.25~0.25), and α is the angle value.

[0030] In the above technical solution, the ratio of the radial width of the tooth yoke 13 to the width of the tooth body 112 is in the range of 0.5 to 1.

[0031] In the above technical solution, the number N of the wire-embedded slots of the stator core 1 is 24 slots, 27 slots, 36 slots, 45 slots, 48 ​​slots, 54 slots, or 63 slots. Figure 1 、 2 As shown, in this embodiment, the number N of wire-embedding slots in the stator core 1 of the motor is 48, and the number of matching permanent magnets 23 is 52. The angle α between the two blanking edges b of the slot opening structure is 5.7° to 9.3°. Preferably, the angle α is 7° to 8°. More preferably, the theoretical value of the angle α in this embodiment is 7.5°. The slot opening height h is 0.2 to 3 mm. Preferably, the slot opening height h is 0.5 to 1.5 mm. More preferably, the slot opening height h is 0.8 to 1 mm. In this embodiment, the slot opening height h is 0.8 to 0.95 mm.

[0032] In the above technical solution: the outer diameter of the stator core 1 ranges from 100 to 300 mm. Preferably, the outer diameter of the stator core 1 is 205 to 215 mm. Further preferably, the outer diameter of the stator core 1 is 206 to 211 mm. Even more preferably, the outer diameter of the stator core 1 is 209 to 211 mm. In this embodiment, the outer diameter of the stator core 1 is 209.3 to 210.5 mm.

[0033] In the above technical solution, the inner diameter of the magnetic ring 22 is 210-224 mm. Preferably, the inner diameter of the magnetic ring 22 is 213-222 mm. More preferably, the inner diameter of the magnetic ring 22 is 214-217 mm. In this embodiment, the inner diameter of the magnetic ring body 12 is 214.8-215.1 mm. In this embodiment, the wall thickness of the magnetic ring is 5-6 mm.

[0034] In the above technical solution: the radial thickness of the permanent magnet 23 is 1.0 to 5.0 mm, preferably, the thickness of the permanent magnet 23 is 1.5 to 3.5 mm, further preferably, the thickness of the permanent magnet 23 is 2 to 2.5 mm, and even further preferably, the thickness of the permanent magnet 23 is 2.2 to 2.3 mm. In this embodiment, the radial thickness of the permanent magnet 23 is 2.3 mm.

[0035] Example 2:

[0036] This embodiment is generally similar to Embodiment 1 in terms of technical solutions, and only the differences are described in detail. The same contents between the two embodiments are not repeated here.

[0037] In this embodiment, the number N of wire-inserting slots 12 in the stator core 1 is 54, and the number of permanent magnets 23 is 60. The included angle α between the two blanking edges of the slot opening structure is 5° to 8.3°. Preferably, the included angle α is 6.5° to 7°. More preferably, the theoretical value of the included angle α in this embodiment is 6.67°.

[0038] In the above technical solution, the outer diameter of the stator core 1 is 215-221 mm. Preferably, the outer diameter of the stator core 1 is 217-218 mm. In this embodiment, the outer diameter of the stator is 217.1-217.4 mm.

[0039] In the above technical solution, the inner diameter of the magnetic ring 22 is 221-224 mm. Preferably, the inner diameter of the magnetic ring 22 is 222-223.4 mm. More preferably, the inner diameter of the magnetic ring 22 is 222-222.3 mm. In this embodiment, the inner diameter of the magnetic ring body 12 is 222-222.2 mm. In this embodiment, the wall thickness of the magnetic ring is 2.7-3.0 mm.

[0040] In the above technical solution, the thickness of the permanent magnet 23 is 1.5-3.0 mm. Preferably, the thickness of the permanent magnet 23 is 1.6-2.3 mm. More preferably, the thickness of the permanent magnet 23 in this embodiment is 2.0 mm.

[0041] Example 3:

[0042] This embodiment is generally similar to Embodiment 1 in terms of technical solutions, and only the differences are described in detail. The same contents between the two embodiments are not repeated here.

[0043] In this embodiment, the number N of wire-inserting slots 12 in the stator core 1 is 54, and the number of permanent magnets 23 is 60. The included angle α between the two blanking edges of the slot opening structure is 5° to 8.3°. Preferably, the included angle α is 6.5° to 7°. More preferably, the theoretical value of the included angle α in this embodiment is 6.67°.

[0044] In the above technical solution, the outer diameter of the stator core 1 is 253 mm to 255 mm. Preferably, the outer diameter of the stator core 1 is 254 mm to 254.5 mm. In this embodiment, the outer diameter of the stator core 1 is 254.1 mm to 254.3 mm.

[0045] In the above technical solution, the inner diameter of the magnetic ring 22 is 259-261 mm. Preferably, the inner diameter of the magnetic ring 22 is 259.5-260.5 mm. More preferably, the inner diameter of the magnetic ring 22 is 259.9-260.1 mm. In this embodiment, the inner diameter of the magnetic ring body 12 is 260-260.1 mm. In this embodiment, the wall thickness of the magnetic ring body 22 is 6-7 mm.

[0046] In the above technical solution, the thickness of the permanent magnet 23 is 2.0-3.0 mm. Preferably, the thickness of the permanent magnet 23 is 2.2-2.6 mm. More preferably, the thickness of the permanent magnet 23 in this embodiment is 2.5 mm.

[0047] The stator core with a trumpet-shaped slot opening, as described in the utility model, features a design scheme for the angles between the two punching edges of the slot opening, ensuring that each punching edge is parallel to the symmetric centerline of the tooth body within which it resides. This greatly simplifies the stator punching process. The slot opening is formed by punching and then rolling, and the punching punch has a sharp blade structure, making punching easy and clean, and forming simple, significantly improving punching efficiency. Furthermore, the dimensional accuracy of the slot opening is significantly improved, and the service life of the punching die is greatly extended. The service life of the die's slot punching structure is more than doubled, effectively reducing die costs. Furthermore, the finished stator core exhibits a unique structural characteristic of "wide outer opening and narrow inner opening," which is highly consistent with the principle of inserting wire from the outside to the inside during the winding process of an external rotor motor stator. This slot structure facilitates the smooth passage of enameled wire through the slot, and the trumpet-shaped opening provides an excellent guide, facilitating wire insertion and reducing the probability of scratching the enameled wire insulation layer. This improves the product qualification rate, increases the winding qualification rate, reduces scrap, and reduces production costs. In addition, the narrow inner opening is conducive to the wire blocking of the slot, which improves the slot fill rate of the winding and plays a positive role in improving the performance of the motor.

[0048] The stator core used in the hub motor for driving electric vehicles provided by the present invention has many advantages: the stator core has a high slot fill rate, which can accommodate more windings within a limited space, thereby improving the power density of the motor; the winding pass rate is high, which reduces the scrap rate caused by poor winding and reduces production costs; the motor has a strong overcurrent capacity, can withstand large currents in a short period of time, and improves the motor's overload capacity; the cogging torque is small, which reduces the vibration and noise of the motor and improves the running stability of the motor. In summary, the motor has excellent performance and can provide reliable and efficient power for electric vehicles.

[0049] The stator core slot opening structure of the utility model has a simple and efficient punching process, which reduces manufacturing costs, has a long service life of the punching die, reduces replacement frequency and cost, has high slot opening precision, and has a strong guiding effect of the trumpet-shaped slot, which is conducive to the passage of enameled wire, improves winding efficiency, qualified rate and slot fill rate, optimizes motor performance and reduces costs.

[0050] The embodiments described in this document are only examples of the present invention and are intended to illustrate the technical solutions of the present invention, rather than to limit the scope of patent protection. Although we have elaborated on the specific implementation methods of the present invention in detail, it is entirely possible for those skilled in the art to make appropriate adjustments or improvements to the present invention without departing from the core spirit and basic principles of the present invention. The scope of protection of the present invention is strictly defined in accordance with the claims and their equivalents. Any improvements, equivalent replacements based on the contents of the specification and drawings of the present invention, or attempts to apply the technical solutions of the present invention to other technical fields, are deemed to be within the scope of patent protection of the present invention.

[0051] Although this article frequently mentions professional terms such as stator core 1, rotor assembly 2, support cover 3, bearing 4, oil seal 5, motor shaft 6, tooth body 11, wire embedding groove 12, tooth yoke 13, slot opening structure 14, shaft sleeve 15, rim 21, magnetic ring 22, permanent magnet 23, tooth crown 111, tooth body 112, punching edges b on the left and right sides of the tooth crown, and slot opening height h, this does not mean that the possibility of using other terms is excluded. The purpose of selecting these terms is to more clearly and accurately describe and explain the core content of the present invention. Any attempt to interpret these terms as additional restrictions on the present invention is inconsistent with the main purpose of the present invention.

Claims

1. A stator core with a trumpet-shaped slot opening, comprising a plurality of tooth bodies (11), a wire embedding slot (12) and a tooth yoke (13), wherein the wire embedding slot (12) is located between two adjacent tooth bodies (11), the tooth bodies (11) are connected to each other through the tooth yoke (13), the wire embedding slot (12) is provided with a slot opening structure at the outer circle of the stator core (1), each tooth body (11) comprises a tooth crown (111) and a tooth body (112), the tooth crown (111) is located at the top of the tooth body (112), and the left and right sides of the tooth crown (111) are provided with a punching edge b, and the gap formed by the punching edges b of each two adjacent tooth bodies (11) constitutes the slot opening structure of the stator core (1), characterized in that The gap gradually widens from the center side of the stator core (1) to the outside to form a trumpet-shaped shape, and the angle α formed by each two adjacent punching edges b and the number N of wire-embedding slots of the stator core (1) satisfy the following relationship: α=（1+β）×360 / N The value range of β is (-0.25~0.25), and α is the angle value.

2. The stator core with trumpet-shaped slot openings according to claim 1, characterized in that: The ratio of the radial width of the tooth yoke (13) to the width of the tooth body (112) is in the range of 0.5 to 1.

3. The stator core with trumpet-shaped slot openings according to claim 1, characterized in that: The number N of wire-embedded slots of the stator core (1) is 24 slots, 27 slots, 36 slots, 45 slots, 48 ​​slots, 54 slots, or 63 slots.

4. A stator core with trumpet-shaped slot openings according to any one of claims 1 to 3, characterized in that: The outer diameter of the stator core (1) ranges from 100 to 300 mm.

5. The stator core with trumpet-shaped slot openings according to claim 1, characterized in that: The slot opening height h is 0.2-3 mm.

6. A motor comprising a stator core having a trumpet-shaped slot opening according to any one of claims 1 to 5, characterized in that: The motor further comprises a rotor assembly (2) and a motor shaft (6), wherein the rotor assembly (2) is sleeved on the outside of the stator core (1), and the rotor assembly (2) comprises a rim (21), a magnetic ring (22) and a plurality of permanent magnets (23), wherein the rim (21) is located on the outside of the magnetic ring (22) and is fixedly connected to the magnetic ring (22), and the plurality of permanent magnets (23) are arranged on the inner circumference of the magnetic ring (22). Support covers (3) are provided on both axial sides of the motor, and the two support covers (3) are fixedly connected to the axial end surfaces of the magnetic ring (22) by screws, and the centers of the two support covers (3) are provided with bearings (4). A shaft sleeve (15) is welded to the center of the stator core (1), and the motor shaft (6) passes through the inner holes of the two bearings (4) and the shaft sleeve (15), and the motor shaft (6) is fixed to the shaft sleeve (15) by interference fit.

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