Slot cover paper, slot cover paper forming tool, motor stator and power assembly

Abstract

The embodiment of the utility model provides slot cover paper, a slot cover paper forming tool, a motor stator and a power assembly. The embodiment of the utility model provides slot cover paper which is used for being installed in a coil slot in a stator core of a motor. The groove cover paper comprises a middle piece body, a first piece body, a second piece body, a first bent piece body and a second bent piece body, the first piece body, the first bent piece body, the middle piece body, the second bent piece body and the second piece body are sequentially connected to define a groove, and the middle piece body is located between the first piece body and the second piece body. The first sheet body is connected with the middle sheet body through the first bending sheet body, the second sheet body is connected with the middle sheet body through the second bending sheet body, and the first sheet body, the first bending sheet body, the middle sheet body, the second bending sheet body and the second sheet body are the same in thickness and equal in length in the stator central axis direction of the motor. The cross sections of the first bending sheet body and the second bending sheet body in a plane perpendicular to the slot cover paper along the central line of the motor stator core are respectively in a bending shape.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of motor technology, and specifically to a slot cover paper, a slot cover paper forming tool, a motor stator, and a power assembly. Background Art

[0002] The motor includes a stator, which includes an iron core and coil slots. Winding coils are embedded in the coil slots, and slot-covering paper is positioned within the coil slots, between the winding coils and the coil slot openings. The slot-covering paper confines the winding coils within the coil slots, isolating them from the iron core at the coil slot openings. The slot-covering paper is typically formed by stamping or rolling. However, the formed slot-covering paper tends to rebound due to its own elasticity, exposing the iron core at the coil slot openings. The slot-covering paper fails to isolate the coils from the iron core, reducing the insulation performance of the motor. Utility Model Content

[0003] Embodiments of the present application provide slot cover paper, slot cover paper forming tooling, a motor stator, and a powertrain. The slot cover paper of the motor stator core is installed in the notch of the stator core coil slot. The slot cover paper provided in the present application can reduce springback after installation, ensuring insulation between the motor stator core winding coil and the notch of the stator core coil slot.

[0004] In a first aspect, an embodiment of the present application provides a slot cover paper for installation in a coil slot on a motor stator core. The slot cover paper includes an intermediate sheet, a first sheet, a second sheet, a first bent sheet, and a second bent sheet. The first sheet, the first bent sheet, the intermediate sheet, the second bent sheet, and the second sheet are sequentially connected to form a groove. The intermediate sheet is located between the first sheet and the second sheet. The first sheet is connected to the intermediate sheet through the first bent sheet, and the second sheet is connected to the intermediate sheet through the second bent sheet. The first sheet, the first bent sheet, the intermediate sheet, the second bent sheet, and the second sheet have the same thickness and the same length along the central axis of the motor stator. The first bent sheet and the second bent sheet each have a bent cross-section in a plane perpendicular to the center line of the slot cover paper along the motor stator core.

[0005] The slot cover paper provided in the embodiment of the present application includes a first bending sheet and a second bending sheet. The first sheet is connected to the middle sheet via the first bending sheet, and the second sheet is connected to the middle sheet via the second bending sheet. This increases the number of bends of the slot cover paper, resulting in a higher proportion of plastic deformation in the deformation of the slot cover paper and a lower rebound of the slot cover paper. Furthermore, the cross-sections of the first bending sheet and the second bending sheet in a plane perpendicular to the centerline of the slot cover paper along the motor stator core are each bent. The rebound directions of the two bends of the first bending sheet and the second bending sheet are opposite, and the rebound effects cancel each other out, thereby reducing the rebound effect of the slot cover paper after installation and ensuring insulation between the motor stator core winding coil and the notch of the stator core coil slot.

[0006] In some embodiments that may include the above embodiments, in a plane perpendicular to the center line of the slot cover paper along the stator core of the motor, cross-sections of the first bent sheet and the second bent sheet are respectively arc-shaped.

[0007] The cross-sections of the first bent sheet and the second bent sheet are arc-shaped, which can reduce the scratches between the slot cover paper and the winding coil and avoid damage to the winding coil.

[0008] In some embodiments that may include the above embodiments, the first bent sheet and the second bent sheet are bent in a direction away from the groove, and the first bent sheet and the second bent sheet are protruded to the outside of the groove.

[0009] The first bent sheet and the second bent sheet are protruded outward from the groove, which can increase the volume of the groove and allow the slot cover to accommodate more winding coils, and is suitable for stators with a larger slot fill rate.

[0010] In some embodiments that may include the above embodiments, the first bent sheet and the second bent sheet are bent toward the groove, and the first bent sheet and the second bent sheet are protruded to the inner side of the groove.

[0011] The first bent sheet and the second bent sheet protrude into the inner side of the groove, which can compress the winding coil and ensure the distance between the winding coil and the iron core. At the same time, the distance between the winding coil and the rotor is increased, the shaft voltage is reduced, and the reliable operation of the motor is ensured.

[0012] In some embodiments that may include the above embodiments, the middle sheet, the first sheet, the first bent sheet, the second bent sheet, and the second sheet are an integral structure.

[0013] The middle sheet, the first sheet, the first bent sheet, the second bent sheet and the second sheet are an integrated structure, which can simplify the forming process of the slot cover paper and reduce the forming difficulty of the slot cover paper.

[0014] In some embodiments, which may include the above embodiments, the slot cover paper is made of insulating wear-resistant paper.

[0015] The slot cover paper is made of insulating and wear-resistant paper, which ensures the insulation of the slot cover paper and improves the insulation between the winding coil and the iron core. It also improves the wear resistance of the slot cover paper, preventing the slot cover paper from being squeezed and damaged when the winding coil is inserted into the coil slot, which would affect the insulation performance of the motor.

[0016] In some embodiments that may include the above embodiments, the slot cover paper is formed by a one-time stamping forming method or a one-time roll forming method.

[0017] The molding tooling of one-time stamping or one-time roll forming is simple, suitable for mass production, and can reduce process difficulty and production cost.

[0018] In a second aspect, embodiments of the present application provide a slot cover paper forming tool, comprising a first forming assembly and a second forming assembly. The first forming assembly is provided with a first forming groove on its surface, and a first extrusion groove is provided at the intersection of the groove bottom and the adjacent groove wall of the first forming groove, the first extrusion groove being disposed away from the first forming groove. The second forming assembly includes a first extrusion body, with two first extrusion protrusions provided on its edge. The first extrusion body is configured to enter the first forming groove and extrude to form the slot cover paper described in some of the aforementioned embodiments.

[0019] The slot cover paper produced by the slot cover paper forming tooling provided in the embodiments of the present application exhibits a higher proportion of plastic deformation and less springback. The first and second bent pieces of the slot cover paper protrude beyond the groove, increasing the volume of the groove and allowing the slot cover paper to accommodate more winding coils, making it suitable for stators with a high slot fill ratio.

[0020] At the same time, the number of bends on the slot cover paper increases, and the rebound directions of the two bends are opposite, offsetting each other's rebound effects, thereby reducing the amount of rebound of the slot cover paper and facilitating its formation. In addition, the slot cover paper forming tooling has a simple structure, consists of fewer forming components, and occupies a small space, making it easy to integrate with the winding and inserting machine.

[0021] In some embodiments that may include the above-mentioned embodiments, the slot cover paper forming tooling includes a first hydraulic lifting mechanism, which is connected to the second forming component through screws. The first hydraulic lifting mechanism is used to lift the second forming component when the slot cover paper forming tooling is working to extrude and form the slot cover paper in some of the above-mentioned embodiments.

[0022] By adjusting the hydraulic pressure, the height of the first hydraulic lifting mechanism can be adjusted, so that the position of the second molding assembly changes, thereby changing the distance between the second molding assembly and the first molding assembly. When the distance between the second molding assembly and the first molding assembly is small enough, the second molding assembly and the first molding assembly are squeezed to form the slot cover paper.

[0023] In some embodiments, which may include the above embodiments, the first extrusion groove is an arc groove.

[0024] When the first extrusion groove is an arc groove, the first extrusion groove leaves more space for the groove cover paper to deform, which is convenient for the groove cover paper to be formed.

[0025] In some embodiments that may include the above embodiments, the length of the first extrusion protrusion in the lifting direction when the second forming assembly is working is greater than or equal to the thickness of the slot cover paper.

[0026] The first extrusion protrusion causes the slot cover paper to bend 180°. This 180° bend creates a larger angle, resulting in a greater proportion of plastic deformation in the deformation of the slot cover paper, facilitating its formation. The length of the first extrusion protrusion along the lifting direction of the second forming assembly during operation is greater than or equal to the thickness of the slot cover paper, ensuring a greater degree of deformation of the slot cover paper, reducing the impact of springback on the slot cover paper, and facilitating its formation.

[0027] In a third aspect, embodiments of the present application provide another slot cover paper forming tool, comprising a third forming assembly and a fourth forming assembly. The third forming assembly has a second forming groove disposed on its surface, and a second extrusion protrusion is disposed at the intersection of the groove bottom and groove wall of the second forming groove, the second extrusion protrusion protruding into the second forming groove. The fourth forming assembly includes a second extrusion body, an edge of which is provided with a second extrusion groove, and the second extrusion body is configured to enter the second forming groove and extrude to form the slot cover paper of some of the aforementioned embodiments.

[0028] The slot cover paper produced by the slot cover paper forming tooling provided in the embodiments of the present application has a higher proportion of plastic deformation and less springback. The first and second bent sheets protrude into the inner side of the groove, compressing the winding coils, ensuring the distance between the winding coils and the core, and increasing the distance between the winding coils and the rotor, thereby reducing shaft voltage and ensuring reliable operation of the motor.

[0029] At the same time, the number of bends on the slot cover paper increases, and the rebound directions of the two bends are opposite, offsetting each other's rebound effects, thereby reducing the amount of rebound of the slot cover paper and facilitating its formation. In addition, the slot cover paper forming tooling has a simple structure, consists of fewer forming components, and occupies a small space, making it easy to integrate with the winding and inserting machine.

[0030] In some embodiments that may include the above-mentioned embodiments, another slot cover paper forming tool includes a second hydraulic lifting mechanism, which is connected to the fourth forming component through screws. The second hydraulic lifting mechanism is used to lift the fourth forming component when the other slot cover paper forming tool is working to extrude and form the slot cover paper in some of the above-mentioned embodiments.

[0031] By adjusting the hydraulic pressure, the height of the second hydraulic lifting mechanism can be adjusted, so that the position of the fourth molding assembly changes, thereby changing the distance between the fourth molding assembly and the third molding assembly. When the distance between the fourth molding assembly and the third molding assembly is small enough, the fourth molding assembly and the third molding assembly are squeezed to form slot cover paper.

[0032] In a fourth aspect, embodiments of the present application provide a motor stator, comprising a stator core, a winding coil, and the slot cover paper of the first aspect described above, wherein the winding coil is installed in the coil slot of the stator core. The slot cover paper is disposed within the coil slot, and along the radial direction of the stator core, the slot cover paper is located at the opening of the coil slot, and the winding coil is located within the cavity enclosed by the slot cover paper and the coil slot.

[0033] The motor stator provided in the embodiments of the present application includes the slot cover paper in any of the above embodiments. The slot cover paper isolates the winding coil and the stator core, thereby ensuring the normal operation of the motor stator, and further ensuring the insulation performance of the motor and ensuring the normal use of the motor.

[0034] In a fifth aspect, an embodiment of the present application provides a powertrain comprising a motor, a motor controller and a reducer, wherein the motor comprises the motor stator of the fourth aspect, and the motor is used to receive the three-phase current transmitted by the motor controller and drive the reducer to output torque.

[0035] The powertrain provided in the embodiment of the present application includes the motor stator of the fourth aspect described above. The motor stator has good insulation performance, which can ensure the normal use of the motor, thereby ensuring the normal use of the powertrain. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A schematic diagram of the structure of the powertrain provided in an embodiment of the present application;

[0037] Figure 2 A schematic diagram of the structure of a motor provided in an embodiment of the present application;

[0038] Figure 3 A schematic structural diagram of a stator provided in an embodiment of the present application;

[0039] Figure 4 It is a structural diagram of slot cover paper in the related art;

[0040] Figure 5 Schematic diagram of the structure of the slot cover paper provided in the embodiment of the present application Figure 1 ;

[0041] Figure 6 Schematic diagram of the structure of the slot cover paper provided in the embodiment of the present application Figure 2 ;

[0042] Figure 7 Schematic diagram of the structure of the slot cover paper forming tool provided in the embodiment of the present application Figure 1 ;

[0043] Figure 8 for Figure 7 AA sectional view;

[0044] Figure 9Schematic diagram of the structure of the slot cover paper forming tool provided in the embodiment of the present application Figure 2 ;

[0045] Figure 10 A schematic diagram of another slot cover paper forming tooling provided in an embodiment of the present application Figure 1 ;

[0046] Figure 11 for Figure 10 BB cross-sectional view;

[0047] Figure 12 A schematic diagram of another slot cover paper forming tooling provided in an embodiment of the present application Figure 2 .

[0048] Description of reference numerals:

[0049] 10: Powertrain; 11: Motor controller; 12: Reducer; 20: Motor; 21: Rotor; 22: Bearing; 30: Stator; 31: Iron core; 32: Coil slot; 33: Slot bottom paper; 34: Winding coil; 40: Slot cover paper; 41: First sheet; 42: Second sheet; 43: Middle sheet; 44: Groove; 51: First bent sheet; 52: Second bent sheet; 60: Slot cover paper forming tool; 61: First forming component; 611: First forming groove; 612: First extrusion groove ; 613: First placement slot; 62: Second molding component; 621: First extrusion body; 622: First extrusion protrusion; 63: First hydraulic lifting mechanism; 631: Hydraulic rod; 632: Connecting rod; 633: Telescopic rod; 70: Another slot cover paper molding tool; 71: Third molding component; 711: Second molding groove; 712: Second extrusion protrusion; 713: Second placement slot; 72: Fourth molding component; 721: Second extrusion body; 722: Second extrusion slot; 73: Second hydraulic lifting mechanism. DETAILED DESCRIPTION

[0050] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0051] In the following, the terms "first," "second," etc. are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the quantity of the technical features indicated. Therefore, a feature specified as "first," "second," etc. may explicitly or implicitly include one or more of the features.

[0052] In addition, in the embodiments of the present application, directional terms such as "up", "down", "left", "right", "horizontal" and "vertical" are defined relative to the orientation of the components in the drawings. It should be understood that these directional terms are relative concepts. They are used for relative description and clarification, and they can change accordingly according to changes in the orientation of the components in the drawings.

[0053] Please refer to Figure 1 The powertrain 10 includes a motor 20, a motor controller 11, and a reducer 12. The motor 20 receives three-phase current from the motor controller 11 and outputs torque through the reducer 12. The powertrain 10 is used in a vehicle and can transmit power generated by the motor 20 to the drive wheels, thereby driving the vehicle.

[0054] The motor controller 11 can control the power output of the motor 20 by adjusting the power supply voltage and current of the motor 20. For example, when the power needs to be increased, the motor controller 11 will increase the power supply voltage and current of the motor 20, thereby increasing the torque and speed of the motor 20, so that the motor 20 outputs more power; when the power needs to be reduced, the motor controller 11 will reduce the power supply voltage and current of the motor.

[0055] The reducer 12 can increase torque and reduce vehicle speed. The embodiment of the present application does not limit the connection method between the motor 20 and the reducer 12. For example, the motor 20 and the reducer 12 can be connected through a coupling transmission or a sprocket transmission.

[0056] Please refer to Figure 2 and Figure 3 The motor 20 includes a stator 30 and a rotor 21, and the rotor 21 is disposed on the stator 30. The magnetic field generated by the rotation of the rotor 21 can induce current with the magnetic field generated by the stator 30, thereby driving the motor 20 to rotate. It can be understood that the rotor 21 is disposed on the stator 30, which means that the rotor 21 is located in the magnetic field of the stator 30, and there is an indirect connection relationship between the rotor 21 and the stator 30. The embodiment of the present application does not limit the specific positions of the stator 30 and the rotor 21. For example, the rotor 21 can be disposed on the axial center line of the stator 30.

[0057] The stator 30 and rotor 21 are not completely insulated. When the motor 20 is powered, a voltage difference exists between the inner and outer rings of the bearing 22. This voltage difference is called the shaft voltage. Excessive shaft voltage can cause breakdown of the oil film between the balls and the inner and outer rings, affecting the reliable operation of the motor 20. The shaft voltage is related to the distance between the stator 30 winding coils 34 and the rotor 21. For example, the greater the distance between the stator 30 winding coils 34 and the rotor 21, the lower the shaft voltage.

[0058] The stator 30 also includes an iron core 31 and slot covers 40. The slot covers 40 are used to cover the winding coils 34 in the coil slots 32. The iron core 31 is provided with coil slots 32 at intervals, and the winding coils 34 are installed in the coil slots 32. The slot covers 40 are arranged in the coil slots 32. In the radial direction of the iron core 31, the slot covers 40 are located at the openings of the coil slots 32. The winding coils 34 are located in the cavity enclosed by the slot covers 40 and the coil slots 32.

[0059] The winding coil 34 is located in the cavity enclosed by the slot cover paper 40 and the coil slot 32. The slot cover paper 40 confines the winding coil 34 within the coil slot 32 and isolates the winding coil 34 from the iron core 31 at the opening of the coil slot 32, preventing contact between the winding coil 34 and the iron core 31 and affecting the insulation performance of the stator 30. At the same time, the slot cover paper 40 increases the distance between the winding coil 34 and the rotor 21, reducing the shaft voltage and ensuring reliable operation of the motor 20.

[0060] The stator 30 also includes slot bottom paper 33, which is positioned within the coil slots 32 at the bottom of the coil slots 32 (on the side of the coil slots 32 away from the opening). This provides insulation protection between the iron core 31 and the coils, preventing electrical short circuits, current leakage, and other issues, thereby ensuring the insulation of the motor 20. It will be appreciated that the slot cover paper 40 contacts the slot bottom paper 33, confining the coils between them and completely isolating them from the iron core 31, thus providing insulation protection for the stator 30.

[0061] Please refer to Figure 3 and Figure 4 , Figure 4 The left side of the figure shows the slot cover paper 40 formed after punching or rolling, while the right side shows the slot cover paper 40 after being left for a while. In related art, the cardboard is bent 90° after punching or rolling to form the slot cover paper 40. The slot cover paper 40 comprises a first sheet 41, an intermediate sheet 43, and a second sheet 42. After the bending, the first angle α between the first sheet 41 and the intermediate sheet 43 is 90°, and the second angle β between the second sheet 42 and the intermediate sheet 43 is 90°.

[0062] However, the slot cover paper 40 itself has a certain elasticity. The formed slot cover paper 40 will rebound significantly under the action of its own elasticity. After rebounding, the first angle α is less than 10°, and the second angle β is less than 10°, resulting in a larger opening of the slot cover paper 40 after forming. In severe cases, it tends to be an unbent plane, causing the slot cover paper 40 to deflect between the coil on one side and the slot bottom paper 33 in the coil slot 32. When the deflection is too large, the other side of the slot cover paper 40 has less contact with the slot bottom paper 33, or even no contact, resulting in the slot cover paper 40 being unable to achieve insulation protection between the winding coil 34 and the iron core 31.

[0063] Please refer to Figure 5 and Figure 6The embodiment of the present application provides a slot cover paper 40 for installation in the coil slot 32 on the iron core 31, comprising an intermediate sheet 43, a first sheet 41, a second sheet 42, a first bent sheet 51, and a second bent sheet 52. It is understood that the width of the intermediate sheet 43 is greater than the width of the opening of the coil slot 32 to prevent the slot cover paper 40 from falling out of the opening of the coil slot 32. The first sheet 41, the first bent sheet 51, the intermediate sheet 43, the second bent sheet 52, and the second sheet 42 are sequentially connected to form a groove 44. The intermediate sheet 43 is located between the first sheet 41 and the second sheet 42. The first sheet 41 is connected to the intermediate sheet 43 through the first bent sheet 51, and the second sheet 42 is connected to the intermediate sheet 43 through the second bent sheet 52.

[0064] There is a first angle α between the first bent sheet 51 and the middle sheet 43. The first angle α is greater than or equal to 15°. For example, α can be selected from 15°, 20°, and 30°. The first sheet 41 can cross the slot bottom paper 33 to connect the winding coil 34 ( Figure 3 The second bent sheet 52 and the intermediate sheet 43 form a second angle β between the second bent sheet 52 and the intermediate sheet 43. The second angle β is greater than or equal to 15°. For example, β can be 15°, 20°, or 30°. The second sheet 42 can fully intersect the slot bottom paper 33, confining the winding coil 34 between the slot cover paper 40 and the slot bottom paper 33, ensuring insulation protection between the coil and the core 31 and maintaining the insulation performance of the motor 20.

[0065] The first sheet 41, the first bent sheet 51, the middle sheet 43, the second bent sheet 52, and the second sheet 42 have the same thickness. In other words, the thickness of the slot cover paper 40 is consistent throughout. The thicknesses of the first sheet 41, the first bent sheet 51, the middle sheet 43, the second bent sheet 52, and the second sheet 42 are all equal to the thickness d of the slot cover paper 40. The present embodiment does not limit the thickness d of the slot cover paper 40. For example, the thickness d of the slot cover paper 40 can be in the range of 0.25-0.3 mm. For example, d can be 0.25 mm, 0.27 mm, or 0.3 mm.

[0066] The lengths of the first sheet 41, the first bent sheet 51, the middle sheet 43, the second bent sheet 52, and the second sheet 42 along the central axis of the stator 30 are equal. In other words, the lengths of the slot cover paper 40 are consistent at all locations. The first sheet 41, the first bent sheet 51, the middle sheet 43, the second bent sheet 52, and the second sheet 42 along the central axis of the stator 30 ( Figure 5 and Figure 6 The length of the slot cover paper 40 is equal to the length of the slot cover paper 40.

[0067] The embodiment of the present application does not limit the length of the slot cover paper 40. For example, the length of the slot cover paper 40 can be equal to the length of the coil slot 32 along the central axis of the stator 30; the length of the slot cover paper 40 can also be greater than the length of the coil slot 32 along the central axis of the stator 30 to ensure that the winding coil 34 does not contact the iron core 31 at the opening of the coil slot 32.

[0068] The first bent sheet 51 and the second bent sheet 52 are perpendicular to the slot cover paper 40 along the center line of the iron core 31 ( Figure 2 The cross sections in the planes indicated by the dotted lines in the figure are respectively bent.

[0069] The first bent sheet 51 has a curved cross-section in a plane perpendicular to the slot cover paper 40 along the centerline of the iron core 31. That is, the first bent sheet 51 is bent relative to the intermediate sheet 43 and the first sheet 41. Forming the first bent sheet 51 requires two bends: the first bend is located at the junction of the intermediate sheet 43 and the first bent sheet 51, and the second bend is located at the bottom of the first bent sheet 51. It will be understood that during the first bend, the first sheet 41 rebounds away from the intermediate sheet 43. During the second bend, the first sheet 41 rebounds toward the intermediate sheet 43. The rebound directions of the two bends are opposite, and the rebound effects cancel each other out, thereby reducing the impact of the rebound on the slot cover paper 40.

[0070] The second bent sheet 52 has a curved cross-section in a plane perpendicular to the slot cover 40 and along the centerline of the iron core 31. In other words, the second bent sheet 52 is bent relative to the middle sheet 43 and the second sheet 42. The second bent sheet 52 is similar to the first bent sheet 51 and will not be described again here.

[0071] The slot cover paper 40 includes a first bent sheet 51 and a second bent sheet 52. The first sheet 41 is connected to the middle sheet 43 via the first bent sheet 51, and the second sheet 42 is connected to the middle sheet 43 via the second bent sheet 52. This increases the number of bends of the slot cover paper 40, increasing the proportion of plastic deformation in the deformation of the slot cover paper 40, thereby reducing the springback of the slot cover paper 40 and facilitating the formation of the slot cover paper 40. Furthermore, the first bent sheet 51 and the second bent sheet 52 each have a bent cross-section in a plane perpendicular to the slot cover paper 40 along the centerline of the iron core 31. The springbacks of the two bends are in opposite directions, offsetting each other's effects. This reduces the springback effect of the slot cover paper 40 after installation and ensures insulation between the winding coil 34 and the notch of the coil slot 32.

[0072] In the above embodiment, the slot cover paper 40 is perpendicular to the center line of the iron core 31 ( Figure 2 In the plane (dashed line in FIG), the cross-sections of the first bent sheet 51 and the second bent sheet 52 are arc-shaped.

[0073] The cross-sections of the first bent sheet 51 and the second bent sheet 52 are arc-shaped, which can reduce the friction between the slot cover paper 40 and the winding coil 34 and avoid damage to the winding coil 34.

[0074] Continue to refer to Figure 5 In some implementations, the first bent sheet 51 and the second bent sheet 52 are bent away from the groove 44 , and the first bent sheet 51 and the second bent sheet 52 protrude to the outside of the groove 44 .

[0075] The first bent sheet 51 and the second bent sheet 52 protrude beyond the groove 44, increasing the volume of the groove 44 and allowing the slot cover 40 to accommodate more winding coils 34. This is suitable for stators 30 with a high slot fill ratio. The slot fill ratio is the ratio of the space occupied by the winding coil 34 after it is inserted into the coil slot 32.

[0076] Continue to refer to Figure 6 In some implementations, the first bent sheet 51 and the second bent sheet 52 are bent toward the groove 44 , and the first bent sheet 51 and the second bent sheet 52 are protruded to the inner side of the groove 44 .

[0077] The first bent sheet 51 and the second bent sheet 52 are protruded into the inner side of the groove 44 to press the winding coil 34 ( Figure 3 As shown), ensure the distance between the winding coil 34 and the iron core 31, and at the same time, increase the distance between the winding coil 34 and the rotor 21, reduce the shaft voltage, and ensure the reliable operation of the motor 20.

[0078] In the above embodiment, the first sheet 41 , the first bent sheet 51 , the middle sheet 43 , the second bent sheet 52 and the second sheet 42 are an integrated structure, which can simplify the forming process of the slot cover paper 40 and reduce the forming difficulty of the slot cover paper 40 .

[0079] In the above embodiment, the slot cover paper 40 is made of insulating and wear-resistant paper. This ensures the insulation of the slot cover paper 40 , improving the insulation between the winding coil 34 and the iron core 31 . It also improves the wear resistance of the slot cover paper 40 , preventing it from being squeezed and damaged when the winding coil 34 is inserted into the coil slot 32 , which could affect the insulation performance of the motor 20 .

[0080] In the above embodiment, the slot cover paper 40 is formed by a single punching process or a single roll forming process. The forming tooling of the single punching process or the single roll forming process is simple, suitable for mass production, and can reduce process difficulty and production cost.

[0081] Please refer to Figure 7 and Figure 8The embodiment of the present application provides a slot cover paper forming tool 60 for forming Figure 5 The slot cover paper 40 shown. The slot cover paper forming tool 60 includes a first forming component 61 and a second forming component 62. The first forming component 61 is provided with a first forming groove 611 on its surface. A first extrusion groove 612 is provided at the intersection of the groove bottom and the adjacent groove wall of the first forming groove 611. The first extrusion groove 612 is arranged away from the first forming groove 611.

[0082] The second forming component 62 includes a first extrusion body 621, and two first extrusion protrusions 622 are provided on the edge of the first extrusion body 621. The first extrusion body 621 is used to squeeze the raw material slot cover paperboard when the raw material slot cover paperboard enters the first forming groove 611 to form Figure 5 The slot cover paper 40 shown. The slot cover paper 40 formed can be connected with the winding coil 34 ( Figure 3 As shown) are synchronously embedded in the coil slot 32.

[0083] The width of the first forming groove 611 is equal to the width of the middle sheet 43 and is greater than the width of the coil slot 32 , ensuring the stability of the slot cover paper 40 at the opening of the coil slot 32 and preventing the slot cover paper 40 from falling.

[0084] The distance d1 between the groove wall of the first molding groove 611 and the first extrusion body 621 is greater than or equal to the thickness d of the groove cover paper 40, which can ensure the thickness of the groove cover paper 40 and the strength of the groove cover paper 40, and prevent the groove cover paper 40 from falling out of the coil groove 32 or being damaged when it is squeezed outward by the winding coil 34.

[0085] A first extrusion groove 612 is provided at the intersection of the groove bottom and the adjacent groove wall of the first forming groove 611. The first extrusion groove 612 is arranged away from the first forming groove 611. The first extrusion body 621 squeezes the raw material groove cover paperboard so that part of the groove cover paperboard enters the first extrusion groove 612, forming a first bent sheet 51 and a second bent sheet 52 protruding to the outside of the groove 44.

[0086] The slot cover paper 40 prepared by the slot cover paper forming tool 60 provided in the embodiment of the present application has a higher proportion of plastic deformation in the deformation, and the slot cover paper 40 has a smaller rebound. The first bent sheet 51 and the second bent sheet 52 are protruding outward from the groove 44, which can increase the volume of the groove 44, so that the slot cover paper 40 can accommodate more winding coils 34, and is suitable for stators 30 with a large slot fill rate ( Figure 2 shown).

[0087] At the same time, the number of bends of the slot cover paper 40 increases, and the rebound directions of the two bends are opposite, so the rebound effects cancel each other out, thereby reducing the rebound amount of the slot cover paper 40 and facilitating the forming of the slot cover paper 40. In addition, the slot cover paper forming tool 60 has a simple tool structure, a small number of forming components, and occupies a small space, making it easy to integrate with the winding and inserting machine.

[0088] In the above embodiment, the first extrusion groove 612 is an arc groove. The present embodiment does not limit the radius of the first extrusion groove 612. For example, the radius of the first extrusion groove 612 may be 0.5 mm. When the first extrusion groove 612 is an arc groove, it provides more space for the slot cover paper 40 to deform, facilitating the forming of the slot cover paper 40.

[0089] In the above embodiment, the length of the first extrusion protrusion 622 in the lifting direction of the second molding assembly 62 during operation is greater than or equal to the thickness of the slot cover paper 40. The present embodiment does not limit the length L1 of the first extrusion protrusion 622. For example, L1 can be 1.4d. In embodiments where d is between 0.25 and 0.3 mm, L1 can be equal to d + 0.1 mm.

[0090] The first extrusion protrusion 622 causes the slot cover paper 40 to bend 180 degrees. Figure 4 Compared with the related technology shown, the bending angle of the 180° bent slot cover paper 40 is larger, so that the plastic deformation accounts for a larger proportion in the deformation of the slot cover paper 40. Therefore, the rebound amount of the slot cover paper 40 in the embodiment of the present application is smaller, which is more conducive to the forming of the slot cover paper 40.

[0091] It is understood that different materials of the slot cover paper 40 result in different toughness (resistance to deformation) of the slot cover paper 40. Different thicknesses of the slot cover paper 40 also result in different toughness. The greater the toughness of the slot cover paper 40, the greater the rebound of the slot cover paper 40. In embodiments where the slot cover paper 40 has higher toughness, the length of the first extrusion protrusion 622 can be increased to reduce the impact of rebound on the slot cover paper 40.

[0092] The length of the first extrusion protrusion 622 in the lifting direction when the second forming component 62 is working is greater than or equal to the thickness of the slot cover paper 40, which can ensure that the slot cover paper 40 is deformed to a greater extent, reduce the impact of rebound on the slot cover paper 40, and facilitate the forming of the slot cover paper 40.

[0093] In the above embodiment, the distance d2 between the first extrusion body 621 and the bottom of the first molding groove 611 is equal to the thickness d of the slot cover paper 40. This distance d2 between the first extrusion body 621 and the first molding groove 611 is equal to the thickness d of the slot cover paper 40, ensuring that the thickness of the intermediate sheet 43 is the same as the thickness of the slot cover paper 40 after molding, ensuring proper use of the slot cover paper 40. In embodiments where the thickness d of the slot cover paper 40 is between 0.25 mm and 0.3 mm, d2 may be between 0.25 mm and 0.3 mm. For example, d2 may be 0.25 mm, 0.27 mm, or 0.3 mm.

[0094] The embodiment of the present application does not limit the thickness of the first extrusion body 621. For example, the thickness of the first extrusion body 621 can be the depth -d of the first molding groove 611, that is, after the first extrusion body 621 extends into the first molding groove 611, the side of the first molding component 61 close to the second molding component 62 and the side of the second molding component 62 close to the first molding component 61 are just in contact; the thickness of the first extrusion body 621 can also be greater than the depth -d of the first molding groove 611, that is, after the first extrusion body 621 extends into the first molding groove 611, there is a gap between the first molding component 61 and the second molding component 62.

[0095] In the above embodiment, the distance d3 between the first extrusion protrusion 622 and the bottom of the first molding groove 611 is less than the thickness d of the slot cover paper 40. When the slot cover paper molding tool 60 is working, the first extrusion protrusion 622 squeezes the slot cover paper 40 at d3, and the slot cover paper 40 is subjected to greater stress at d3. It can be understood that, under the same thickness, the greater the stress on the slot cover paper 40, the greater the proportion of plastic deformation in the deformation of the slot cover paper 40, and the smaller the rebound of the slot cover paper 40. The embodiment of the present application does not limit the size of d3. For example, d3 can include 0.6d. In the embodiment where d includes 0.25-0.3mm, d3 can include d-0.1mm.

[0096] The distance d3 between the first extrusion protrusion 622 and the bottom of the slot is smaller than the thickness d of the slot cover paper 40 , so that the slot cover paper 40 is squeezed, the plastic deformation accounts for a larger proportion in the deformation, and the rebound amount of the slot cover paper 40 is small, which is conducive to the forming of the slot cover paper 40 .

[0097] In the above embodiment, the two corners of the first extrusion protrusion 622 close to the first extrusion groove 612 include rounded corners. The embodiment of the present application does not limit the radius of the rounded corners. For example, the radius of the rounded corners may include 0.1 mm.

[0098] It can be understood that when the slot cover paper forming tooling 60 is working, the first extrusion protrusion 622 has a relatively large downward moving speed. The rounded corners can avoid stress concentration and disperse the stress of the two corners on the slot cover paper 40, thereby avoiding excessive stress on the cover paper from the two corners, which may cause damage to the slot cover paper 40.

[0099] In the above embodiment, the first molding assembly 61 further includes a first placement groove 613, which is located on a side of the second molding assembly 62 adjacent to the first molding assembly 61. The width of the first placement groove 613 is greater than or equal to the width of the slot cover paper 40. The first placement groove 613 is used to receive the slot cover paperboard and limit the position of the paperboard to prevent the slot cover paperboard from moving when the first extrusion body 621 extends into the first molding groove 611, resulting in a failure in molding the slot cover paper 40.

[0100] Please refer to Figure 9 In the above embodiment, the slot cover paper forming tool 60 further includes a first hydraulic lifting mechanism 63, which is connected to the second forming component 62 by screws. The first hydraulic lifting mechanism 63 is used to lift the second forming component 62 when the slot cover paper forming tool 60 is working to extrude and form Figure 5 The slot cover paper 40 is shown.

[0101] The first hydraulic lifting mechanism 63 may include a hydraulic rod 631, a connecting rod 632, and a telescopic rod 633. The connecting rod 632 is connected to the telescopic rod 633 at both ends. The telescopic rod 633 is connected to the second molding assembly 62 at one end and fixed at one end. When the hydraulic pressure is raised, the hydraulic rod 631 extends, moving the connecting rod 632, which in turn moves the telescopic rod 633, which in turn moves the second molding assembly 62. This increases the distance between the second molding assembly 62 and the fixed end, i.e., the second molding assembly 62 moves closer to the first molding assembly 61.

[0102] By adjusting the hydraulic pressure, the height of the first hydraulic lifting mechanism 63 can be adjusted, so that the position of the second molding component 62 is changed, thereby changing the distance between the second molding component 62 and the first molding component 61. When the distance between the second molding component 62 and the first molding component 61 is small enough (for example, the distance is 0), the second molding component 62 and the first molding component 61 are squeezed to form the slot cover paper 40.

[0103] Please refer to Figure 10 and Figure 11 The present invention provides another slot cover paper forming tool 70 for forming Figure 6Another slot cover paper forming tool 70 includes a third forming component 71 and a fourth forming component 72. The third forming component 71 has a second forming groove 711 formed on its surface. A second extrusion protrusion 712 is provided at the intersection of the groove bottom and the adjacent groove wall of the second forming groove 711. The second extrusion protrusion 712 protrudes into the second forming groove 711.

[0104] The fourth forming component 72 includes a second extrusion body 721. Two second extrusion grooves 722 are provided on the edge of the second extrusion body 721. The second extrusion body 721 is used to squeeze the slot cover paperboard to form a second forming groove 711 when the slot cover paper 40 enters the second forming groove 711 during the forming process. Figure 6 The slot cover paper 40 shown. The slot cover paper 40 formed can be connected with the winding coil 34 ( Figure 3 As shown) are synchronously embedded in the coil slot 32.

[0105] The width of the second forming groove 711 is equal to the width of the middle sheet 43 and is greater than the width of the coil slot 32 , ensuring the stability of the slot cover paper 40 at the opening of the coil slot 32 and preventing the slot cover paper 40 from falling.

[0106] The distance d4 between the groove wall of the second molding groove 711 and the second extrusion body 721 is greater than or equal to the thickness d of the groove cover paper 40, which can ensure the thickness of the groove cover paper 40, ensure the strength of the groove cover paper 40, and prevent the groove cover paper 40 from falling out of the coil groove 32 or being damaged when it is squeezed outward by the winding coil 34.

[0107] Two second extrusion grooves 722 are provided on the edge of the second extrusion body 721, and the second extrusion protrusion 712 protrudes into the second forming groove 711. The second extrusion body 721 extrudes the groove cover cardboard, so that part of the groove cover cardboard enters the second extrusion groove 722, forming the first bent sheet 51 and the second bent sheet 52 protruding into the inner side of the groove 44.

[0108] The slot cover paper 40 prepared by another slot cover paper forming tool 70 provided in the embodiment of the present application has a higher proportion of plastic deformation in the deformation, and the slot cover paper 40 has less rebound. The first bent sheet 51 and the second bent sheet 52 are protruded into the inner side of the groove 44, which can press the winding coil 34 to ensure that the winding coil 34 is aligned with the iron core 31 ( Figure 2 As shown), the distance between the winding coil 34 and the rotor 21 ( Figure 2 As shown), reduce the shaft voltage and ensure that the motor 20 ( Figure 2 Reliable operation of the

[0109] At the same time, the number of bends of the slot cover paper 40 increases, and the rebound directions of the two bends are opposite, so the rebound effects cancel each other out, thereby reducing the rebound amount of the slot cover paper 40 and facilitating the forming of the slot cover paper 40. In addition, the alternative slot cover paper forming tool 70 has a simple tool structure, fewer forming components, and occupies less space, making it easy to integrate with the winding and inserting machine.

[0110] In the above embodiment, the distance d5 between the second extrusion body 721 and the bottom of the second molding groove 711 is equal to the thickness d of the slot cover paper 40. This distance d5 between the second extrusion body 721 and the second molding groove 711 is equal to the thickness d of the slot cover paper 40, ensuring that the thickness of the intermediate sheet 43 is the same as the thickness of the slot cover paper 40 after molding, ensuring proper use of the slot cover paper 40. In embodiments where the thickness d of the slot cover paper 40 is between 0.25 and 0.3 mm, d5 may be between 0.25 and 0.3 mm. For example, d5 may be 0.25 mm, 0.27 mm, or 0.3 mm.

[0111] The embodiment of the present application does not limit the thickness of the second extruded body 721 . The second extruded body 721 is similar to the first extruded body 621 and will not be described in detail herein.

[0112] In the above embodiment, the distance d6 between the second extrusion protrusion 712 and the second extrusion body 721 is less than the thickness d of the slot cover paper 40. When the slot cover paper forming tool 60 is working, the second extrusion protrusion 712 squeezes the slot cover paper 40 at d6, and the slot cover paper 40 is subjected to greater stress at d6. It can be understood that, under the same thickness, the greater the stress on the slot cover paper 40, the greater the proportion of plastic deformation in the deformation of the slot cover paper 40, and the smaller the rebound of the slot cover paper 40. The embodiment of the present application does not limit the size of d6. For example, d6 can include 0.6d. In the embodiment where d includes 0.25-0.3mm, d6 can include d-0.1mm.

[0113] The distance d6 between the second extrusion protrusion 712 and the second extrusion body 721 is smaller than the thickness d of the slot cover paper 40, so that the slot cover paper 40 is squeezed, the plastic deformation accounts for a larger proportion in the deformation, and the rebound amount of the slot cover paper 40 is small, which is conducive to the forming of the slot cover paper 40.

[0114] In the above embodiment, the cross-section of the second extrusion protrusion 712 is arc-shaped in a plane parallel to the direction of movement of the second extrusion body 721. It will be appreciated that when the alternative slot cover paper forming tool 70 is in operation, the second extrusion body 721 moves downward at a relatively high speed. The second extrusion protrusion 712 exerts significant stress on the slot cover paperboard. The rounded corners can avoid stress concentration and distribute the stress exerted by the second extrusion protrusion 712 on the slot cover paperboard 40, preventing excessive stress from causing damage to the slot cover paperboard 40.

[0115] In the above embodiment, the fourth molding assembly 72 further includes a second placement groove 713, which is located on a side of the fourth molding assembly 72 adjacent to the third molding assembly 71. The width of the second placement groove 713 is greater than or equal to the width of the slot cover paper 40. The second placement groove 713 is used to receive the cardboard and limit its position to prevent the cardboard from shifting when the second extrusion body 721 extends into the second molding groove 711, which could result in a failure in molding the slot cover paper 40.

[0116] Please refer to Figure 12 In the above embodiment, another slot cover paper forming tool 70 includes a second hydraulic lifting mechanism 73, which is connected to the fourth forming component 72 by screws. The second hydraulic lifting mechanism 73 is used to lift the fourth forming component 72 when the another slot cover paper forming tool 70 is working to extrude and form Figure 6 The slot cover paper 40 is shown.

[0117] The second hydraulic lifting mechanism 73 is similar to the first hydraulic lifting mechanism 63 and will not be described in detail here.

[0118] By adjusting the hydraulic pressure, the height of the second hydraulic lifting mechanism 73 can be adjusted, so that the position of the fourth molding component 72 is changed, thereby changing the distance between the fourth molding component 72 and the third molding component 71. When the distance between the fourth molding component 72 and the third molding component 71 is small enough (for example, the distance is 0), the fourth molding component 72 and the third molding component 71 are squeezed to form the slot cover paper 40.

[0119] Continue to refer to Figure 10 and Figure 11 In the above embodiment, the second extrusion groove 722 is an arc groove. The second extrusion groove 722 is similar to the first extrusion groove 612 and will not be described in detail here.

[0120] In the above embodiment, the length L2 of the second extrusion protrusion 712 in the lifting direction of the fourth molding assembly 72 is greater than or equal to the thickness of the slot cover paper 40. The second extrusion protrusion 712 is similar to the first extrusion protrusion 622 and will not be described again.

[0121] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A slot cover paper, characterized in that: The slot cover paper is used to be installed in the coil slot on the stator core of the motor, and the slot cover paper includes a middle sheet, a first sheet, a second sheet, a first bent sheet, and a second bent sheet, wherein: The first sheet, the first bent sheet, the middle sheet, the second bent sheet, and the second sheet are sequentially connected to form a groove, and the middle sheet is located between the first sheet and the second sheet; The first sheet is connected to the middle sheet via the first bent sheet, and the second sheet is connected to the middle sheet via the second bent sheet; The first sheet, the first bent sheet, the middle sheet, the second bent sheet, and the second sheet have the same thickness and the same length along the central axis of the motor stator; The cross sections of the first bent sheet and the second bent sheet in a plane perpendicular to the slot cover paper and along the center line of the motor stator core are respectively in a bent shape.

2. The slot cover paper according to claim 1, characterized in that: In a plane perpendicular to the center line of the motor stator core along the slot cover paper, cross sections of the first bent sheet and the second bent sheet are respectively arc-shaped.

3. The slot cover paper according to claim 1 or 2, characterized in that: The first bent sheet and the second bent sheet are bent in a direction away from the groove, and the first bent sheet and the second bent sheet are protruded out of the groove.

4. The slot cover paper according to claim 1 or 2, characterized in that: The first bent sheet and the second bent sheet are bent toward the groove, and the first bent sheet and the second bent sheet are protruded to the inner side of the groove.

5. The slot cover paper according to any one of claims 1 to 4, characterized in that: The middle sheet, the first sheet, the first bent sheet, the second bent sheet and the second sheet are an integrated structure.

6. The slot cover paper according to any one of claims 1 to 5, characterized in that: The slot cover paper is made of insulating wear-resistant paper.

7. The slot cover paper according to any one of claims 1 to 6, characterized in that: The slot cover paper is formed by one-time stamping or one-time rolling.

8. A slot cover paper forming tool, characterized in that: include: a first molding component, wherein a first molding groove is provided on a surface of the first molding component, a first extrusion groove is provided at a junction between a groove bottom and an adjacent groove wall of the first molding groove, and the first extrusion groove is arranged away from the first molding groove; The second molding component includes a first extrusion body, two first extrusion protrusions are provided on the edge of the first extrusion body, and the first extrusion body is used to enter the first molding groove and extrude to form the slot cover paper according to claim 3.

9. The slot cover paper forming tool according to claim 8, characterized in that: The slot cover paper forming tooling includes a first hydraulic lifting mechanism, which is connected to the second forming component through screws. The first hydraulic lifting mechanism is used to lift the second forming component when the slot cover paper forming tooling is working to extrude and form the slot cover paper described in claim 3.

10. A slot cover paper forming tool according to claim 8 or 9, characterized in that: The first extrusion groove is an arc groove.

11. A slot cover paper forming tool according to any one of claims 8 to 10, characterized in that: The length of the first extrusion protrusion in the lifting direction when the second forming assembly is working is greater than or equal to the thickness of the slot cover paper.

12. Another slot cover paper forming tool, characterized in that: include: a third molding component, wherein a second molding groove is provided on the surface of the third molding component, a second extrusion protrusion is provided at the intersection of the groove bottom and the groove wall of the second molding groove, and the second extrusion protrusion protrudes into the second molding groove; The fourth molding component includes a second extrusion body, a second extrusion groove is provided on the edge of the second extrusion body, and the second extrusion body is used to enter the second molding groove to extrude and form the slot cover paper according to claim 4.

13. Another slot cover paper forming tool according to claim 12, characterized in that: The other slot cover paper forming tooling includes a second hydraulic lifting mechanism, which is connected to the fourth forming component through screws. The second hydraulic lifting mechanism is used to lift the fourth forming component when the other slot cover paper forming tooling is working to extrude and form the slot cover paper described in claim 4.

14. A motor stator, characterized in that: The motor stator includes the stator core, the winding coil and the slot cover paper according to any one of claims 1 to 7, the winding coil is installed in the coil slot of the stator core, the slot cover paper is arranged in the coil slot, and the slot cover paper is located at the opening of the coil slot along the radial direction of the stator core, and the winding coil is located in the cavity enclosed by the slot cover paper and the coil slot.

15. A powertrain, characterized in that: The powertrain includes a motor, a motor controller and a reducer. The motor includes the motor stator according to claim 14. The motor is used to receive the three-phase current transmitted by the motor controller and drive the reducer to output torque.

Images