A wheel hub motor for electric vehicles

Abstract

This invention discloses a hub motor for electric vehicles, comprising a stator, a rotor, and a connecting shaft. The stator includes an iron core and a support, with the iron core fixed to the support. The iron core is formed by stacking stator laminations in a helical winding manner. The slot width of the stator teeth satisfies the following relationship with the outer diameter of the iron core, the thickness of the tooth lip of the iron core, the inner diameter of the iron core, the thickness of the yoke of the iron core, the number of tooth slots in the iron core, and the slot width of the stator laminations: Slot width = π × [outer diameter of iron core - 2 × thickness of tooth lip of iron core - 2 × α × (inner diameter of iron core + thickness of yoke of iron core)] ÷ number of tooth slots in the iron core + slot width of the stator laminations, where α ranges from 0.45 to 0.55, and the slot width of the stator laminations ranges from 0 to 2 mm. The beneficial effects of this invention are: the stator structure of this invention optimizes the tooth structure of the motor, improves the power density and working efficiency of the motor, enhances the short-term overload capacity of the motor, reduces the temperature rise and manufacturing cost of the motor, and extends its service life.

Description

Technical Field

[0001] This invention relates to the field of electric vehicle technology, and in particular to a hub motor for electric vehicles. Background Technology

[0002] With the continuous development of technology, electric vehicles are becoming increasingly popular as a green means of transportation. They are gradually being promoted from flat roads in cities to complex road conditions such as rural areas and mountainous regions, especially in the application of agricultural transportation in rural areas. However, due to the lightweight and environmentally friendly characteristics of electric vehicles, the performance expansion space of electric vehicle hub motors is limited. As the drive component of electric vehicles, optimizing motor performance has become the goal of continuous research and development in the field of electric vehicle technology within extremely limited space.

[0003] Currently, most electric vehicle motors on the market use hub motors as drive components. However, hub motors are generally disc-shaped and have a relatively flat structure, which leads to significant waste during stator stamping. The single-stamp stacked structure has a low reusability rate for the inner ring blanks, resulting in high manufacturing costs. In contrast, the slots of the spirally rolled stator are naturally rolled out from the long stator laminations. The size of these slots is related to the shape of the stator teeth and the inner and outer diameters of the stator. Since the slots affect the cogging torque of the motor, they are related to the motor's working efficiency and output stability. Therefore, those skilled in the art are dedicated to developing a hub motor for electric vehicles that reduces the impact of cogging torque and improves motor performance. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a hub motor for electric vehicles that features strong load-bearing and overload capacity, high efficiency, low cogging torque, and long service life. The hub motor for electric vehicles provided by this invention possesses high efficiency, high torque, and high stability. This motor can withstand large loads, has strong vibration and shock resistance, and can handle large currents for short periods. By optimizing the motor's magnetic circuit, copper and iron dust are reduced, making the motor less prone to overheating and resulting in a low failure rate. Simultaneously, it significantly improves the motor's working efficiency and output torque, and extends its service life.

[0005] To achieve the aforementioned objective, the present invention provides a stator for a hub motor for electric vehicles, comprising a stator, a rotor, a connecting shaft, and other accessories such as a Hall effect sensor. The Hall effect sensor is installed in a Hall effect slot in the stator. The stator is circumferentially positioned with respect to the connecting shaft. The rotor is sleeved on the outside of the stator. The stator includes an iron core and a support frame. The support frame is secured by two support plates that abut against each other. The edges of the support plates extend outwards in a circumferential shape towards the opposite side of the abutment surfaces. The iron core is composed of tooth ribs, a yoke, and tooth grooves. The iron core is fixed to the outer circumferential surface of the support frame. The iron core is characterized by being formed by stacking stator laminations in a spiral winding manner. The tooth grooves are formed by naturally unrolling stator laminations. The groove opening width satisfies the following relationships with the outer diameter of the iron core, the tooth lip thickness of the iron core, the inner diameter of the iron core, the yoke thickness of the iron core, the number of tooth grooves in the iron core, and the groove opening width of the stator laminations:

[0006] The slot width of the stator lamination = π × [outer diameter of the core - 2 × thickness of the core tooth lip - 2 × α × (inner diameter of the core + thickness of the core yoke)] ÷ number of core teeth + slot width of stator lamination

[0007] Where π is the mathematical constant pi, α ranges from 0.45 to 0.55, and the slot width of the stator laminations ranges from 0 to 2 mm.

[0008] The iron core has several Hall slots at the same axial end. The Hall slots are close to the outer circumferential surface of the iron core and are distributed circumferentially. Among the Hall slots, there is at least one slot opening Hall slot and two toothed Hall slots. The center of the slot opening Hall slot is located on the symmetrical center line of the toothed slot. The slot opening Hall slot is located at the slot opening and forms a cavity with the built-in element in the slot. The two toothed Hall slots are located on the toothed ribs on both sides of the slot opening Hall slot and are in the same axial projection plane. The center line connecting the center of the two toothed Hall slots and the center of the iron core forms the same symmetrical angle β with the symmetrical center line of the toothed slot where the slot opening Hall slot is located. The value of β is in the range of 9.5 degrees to 15.5 degrees.

[0009] The bracket consists of two different disc-shaped first and second support plates that are fastened together. The first support plate has several flip-out protrusions distributed circumferentially, with the flip-out protrusions protruding outward toward the side of the first support plate that is against it. The second support plate has several weight-reducing holes, which correspond one-to-one with the flip-out protrusions. The flip-out protrusions pass through the weight-reducing holes they are paired with, and through external force, the outward protrusions of the flip-out protrusions are flipped outward and tightly fastened to the non-opposing panel near the inner circle of the weight-reducing hole, forming a flanged fastening structure. The two support plates have welded flanges at their centers, and the bracket is welded to the outer circumferential surface near the two ends of the same bushing through the welded flanges.

[0010] The stator laminations are provided with self-locking grooves, which are located on the yoke or toothed part of the iron core. The self-locking grooves on both sides of the stator laminations have a groove on one side and a protrusion on the other side. When the stator laminations are stacked, the position and shape of the groove and protrusion on the self-locking grooves between adjacent laminations correspond to each other to form a positioning and fastening structure.

[0011] The inner circumferential surface of the iron core is provided with several arc-shaped anti-rotation grooves, and the circumferential surfaces of the two support plates are provided with several arc-shaped outward-protruding anti-rotation ribs. The anti-rotation ribs and anti-rotation grooves are fitted together to form a circumferential positioning and anti-rotation connection pair.

[0012] The cavity of the tooth groove contains a copper wire winding, which is wound around the tooth rib in a clockwise or counterclockwise direction.

[0013] The Hall component consists of three Hall elements of the same specification welded onto the same circuit board. The Hall elements are circumferentially distributed on the circuit board and their positions correspond to and match the Hall slots of the slot and the two toothed Hall slots. The circuit board is laid on both sides and the external wiring solder points are distributed on opposite sides to the Hall elements. The exposed metal contacts of the Hall elements are covered with insulating sleeves.

[0014] Among them, the number of slots and included angle β of the iron core are 48 slots with included angle β ranging from 10.6 degrees to 11.85 degrees, 54 slots with included angle β ranging from 9.7 degrees to 10.3 degrees, 51 slots with included angle β ranging from 10 degrees to 11 degrees, and 36 slots with included angle β ranging from 14.5 degrees to 15.5 degrees.

[0015] The rotor includes a rim, a magnetic ring, and several permanent magnets. The inner ring of the rim is fixed to the outer circumference of the magnetic ring by welding. The permanent magnets are evenly distributed and pasted on the inner circumference of the magnetic ring with alternating north and south poles. The rim has valve core mounting holes.

[0016] The inner diameter of the magnetic ring of the rotor is 205-265mm, the thickness of the magnetic ring is 5-10mm, and the height of the magnetic ring is 30mm-60mm.

[0017] The outer diameter of the iron core is 198–256 mm, the width of the tooth ribs of the iron core is 4–7 mm, the thickness of the yoke of the iron core is 4–6 mm, the inner diameter of the iron core is 157–215 mm, the groove width of the tooth is 1.5–4 mm, and the tooth lip thickness of the iron core is 0.8–2 mm.

[0018] The thickness of the permanent magnet is 1.8 to 5 mm.

[0019] The electric vehicle hub motor provided by this invention optimizes the design of the motor's tooth structure, with reasonable tooth and tooth groove design. On the basis of ensuring a reasonable motor magnetic circuit, it optimizes the tooth groove structure of the stacked stator, reduces the motor's tooth torque, improves the motor's positioning accuracy and working efficiency, makes the motor run more smoothly, effectively controls motor vibration and noise, and extends the motor's service life.

[0020] The electric vehicle hub motor provided by this invention features a support plate with irregularly shaped reinforcing ribs. It is secured using interlocking buckle holes and weight-reducing holes on the support, eliminating the need for traditional riveting. This optimized stator, on the one hand, eliminates the safety hazards of soft, easily deformed, or even detached rivets that could cause motor malfunctions, saving material costs. On the other hand, the multi-hole interlocking weight-reducing hole structure, with its iron-faced buckle, offers good hardness and toughness, resulting in strong support stability, increased clamping surface, greater clamping force, and high strength from the multi-ribbed, irregularly shaped support. Furthermore, it improves stator manufacturing efficiency, ensures product consistency, and enhances stator manufacturing precision, thereby improving motor energy conversion efficiency and optimizing motor performance.

[0021] The hub motor using the stator structure of this invention has good structural stability, significantly improved load-bearing capacity and vibration and impact resistance, can withstand larger and more frequent impact loads, greatly reduces the motor failure rate, further improves safety characteristics, and is better adapted to harsh environments and complex and changing road conditions. At the same time, the stable stator structure and optimized stator core slot structure improve the motor's working efficiency.

[0022] The comparison shows that after structural optimization, the load capacity of the hub motor for this electric vehicle has been significantly improved, its structural stability is guaranteed, its safety stability and motor output performance have been greatly improved, the motor power has been increased, its short-term overload tolerance has been strengthened, and the motor process has been effectively optimized, resulting in improved production efficiency and a significant reduction in motor failure rate.

[0023] The following will further explain the concept, specific structure, and technical effects of the present invention in conjunction with the accompanying drawings, so as to fully understand the purpose, features, and effects of the present invention. Attached Figure Description

[0024] Figure 1 This is a partial structural schematic diagram of the hub motor for electric vehicles according to the present invention;

[0025] Figure 2 This is a schematic diagram of the stator structure of the hub motor for electric vehicles according to the present invention;

[0026] Figure 3 This is a cross-sectional view of the overall structure of the hub motor for electric vehicles according to the present invention;

[0027] Figure 4 This is a cross-sectional view of the stator structure of the hub motor for electric vehicles according to the present invention;

[0028] Figure 5 This is an exploded view of the stator of the hub motor for electric vehicles according to the present invention;

[0029] Figure 6 This is a schematic diagram of the stator core of the hub motor for electric vehicles of the present invention;

[0030] Figure 7 for Figure 6 Enlarged structural diagram at point A in the middle;

[0031] Figure 8 for Figure 4 Enlarged structural diagram at point B;

[0032] Figure 9 This is a partial exploded view of the hub motor for electric vehicles according to the present invention;

[0033] Figure 10 This is a performance comparison curve table between a motor using the stator of the electric vehicle hub motor of the present invention and an existing hub motor.

[0034] The components are as follows: 1. Stator; 2. Iron core; 3. Bracket; 4. Bushing; 5. Rotor; 6. Connecting shaft; 7. Valve core; 8. Screw; 21. Hall groove; 22. Hall groove of tooth rib; 23. Tooth groove; 24. Tooth rib; 25. Yoke; 26. Groove; 27. Anti-rotation groove; 31. First support plate; 32. Second support plate; 33. Anti-rotation rib; 34. Reinforcing rib; 35. Winding positioning hole; 36. Concave surface of anti-rotation rib; 37. Binding strap fixing hole; 38. Press-fit hole; 39. Welded flange; 40. Circumferential surface; 41. Alignment surface; 51. Rim; 52. Magnetic guide ring; 53. Permanent magnet; 54. Valve core mounting hole; 311. Flip-out protrusion; 312. Flip; 321. Weight reduction hole. B1, width of the tooth rib of the iron core; B2, width of the tooth groove; H1, thickness of the yoke of the iron core; H2, thickness of the tooth lip of the iron core. Detailed Implementation

[0035] The following description, with reference to the accompanying drawings, illustrates several preferred embodiments of the present invention to make its technical content clearer and easier to understand. The present invention can be embodied in many different forms, and the scope of protection of the present invention is not limited to the embodiments mentioned herein.

[0036] In the accompanying drawings, components with the same structure are indicated by the same numerical designation, and components with similar structures or functions are indicated by similar numerical designations. The dimensions and thicknesses of each component shown in the drawings are arbitrary, and the present invention does not limit the dimensions and thicknesses of each component. To make the illustrations clearer, the thickness of some components has been appropriately exaggerated in the drawings.

[0037] Although this article uses a lot of terms such as stator 1, iron core 2, bracket 3, bushing 4, rotor 5, connecting shaft 6, valve core 7, screw 8, slot Hall groove 21, tooth rib Hall groove 22, tooth groove 23, tooth rib 24, yoke 25, slot 26, anti-rotation groove 27, first support plate 31, second support plate 32, anti-rotation rib 33, reinforcing rib 34, winding positioning hole 35, anti-rotation rib concave surface 36, binding strap fixing hole 37, press-fit hole 38, welding flange 39, circumferential surface 40, mating surface 41, rim 51, magnetic ring 52, permanent magnet 53, valve core mounting hole 54, buckle protrusion hole 311, flange 312, weight reduction hole 321, iron core tooth rib width B1, tooth groove slot width B2, iron core yoke thickness H1, iron core tooth lip thickness H2, etc., the possibility of using other terms cannot be excluded. The use of these terms is merely for the convenience of describing and explaining the nature of the invention; interpreting them as any additional limitation would be contrary to the spirit of the invention.

[0038] Example 1:

[0039] like Figures 1 to 9 As shown, this embodiment provides a hub motor for electric vehicles, including a stator 1, a rotor 5, a connecting shaft 6, and other accessories such as Hall effect sensors. The stator 1 is circumferentially positioned with the connecting shaft 6, and the rotor 5 is sleeved on the outside of the stator 1. The stator 1 includes an iron core 2 and a bracket 3. The bracket 3 is fastened together by two support plates. The edges of the support plates extend into a circumferential surface 40 on the opposite side of the abutting surface 41. The iron core 2 is composed of toothed ribs 24, a yoke 25, and toothed grooves 23. The iron core 2 is fixed on the outer circumferential surface 40 of the bracket 3. A bushing 4 is welded to the center of the bracket 3. Several Hall effect grooves are provided at the axial ends of the iron core 2 for mounting Hall effect sensors. Several arc-shaped anti-rotation grooves 27 are provided on the inner circumferential surface of the iron core 2. Several outwardly protruding anti-rotation ribs 33 are provided on the circumferential surface 40 of the two support plates. The anti-rotation ribs 33 and the anti-rotation grooves 27 are fitted together to form a circumferential positioning and anti-rotation connection pair. A copper wire winding is placed in the cavity of the tooth groove 23. The copper wire winding is wound on the tooth rib 24 in a clockwise or counterclockwise direction.

[0040] In this embodiment, the iron core 2 is formed by stacking stator laminations in a spiral winding manner. The stator laminations are provided with self-locking grooves, which are located on the yoke 25 or tooth rib 24 of the iron core 2. The self-locking grooves on both sides of the stator laminations have a groove on one side and a protrusion on the other side. When the stator laminations are stacked, the position and shape of the groove and protrusion on the self-locking grooves between adjacent layers correspond to each other to form a positioning and tight fastening knot.

[0041] In this embodiment, the Hall effect assembly is installed in the Hall effect slot of the stator. The Hall effect assembly consists of three Hall elements of the same specification soldered onto the same circuit board. The Hall elements are circumferentially distributed on the circuit board and their positions correspond to and match the Hall effect slot 21 at the slot opening and the two toothed Hall effect slots 22. The circuit board is laid on both sides, and the external wiring solder joints are distributed on opposite sides to the Hall elements. The exposed metal contacts of the Hall elements are covered with insulating sleeves.

[0042] In this embodiment, a plurality of Hall slots are provided at the same axial end of the iron core 2. The Hall slots are close to the outer circumferential surface of the iron core 2 and are distributed circumferentially. Among the Hall slots, there is at least one slot Hall slot 21 and two toothed Hall slots 22. The center of the slot Hall slot 21 is located on the symmetrical center line of the toothed slot 23. The slot Hall slot 21 is located at the slot 26 and forms a cavity with the internal component of the slot. The two toothed Hall slots 22 are respectively located on the toothed ribs 24 on both sides of the slot Hall slot 21, and are in the same axial projection plane. The center line connecting the center of the two toothed Hall slots 22 and the center of the iron core 2 forms the same symmetrical angle β with the symmetrical center line of the toothed slot 23 where the slot Hall slot 21 is located. The value of β is in the range of 9.5 degrees to 15.5 degrees. Preferably, the value of β is in the range of 11.27 degrees to 11.81 degrees. More preferably, in this embodiment, the value of β is 11.54 degrees. It should be noted that the value of β in this invention is an angle value in "degrees".

[0043] In this embodiment, the bracket 3 is fixed by two different disc-shaped first support plates 31 and second support plates 32. The first support plate 31 is provided with a plurality of flip-fastening protrusions 311 distributed circumferentially. The flip-fastening protrusions 311 protrude outward toward the side of the first support plate 31 facing the mating surface 41. The second support plate 32 is provided with a plurality of weight-reducing holes 321. The weight-reducing holes 321 correspond one-to-one with the flip-fastening protrusions 311. The flip-fastening protrusions 311 pass through the weight-reducing holes 321 they are paired with, and by external force, the outward protrusion of the flip-fastening protrusions 311 is flipped outward and tightly fastened to the non-matting panel near the inner circle of the weight-reducing hole 321, forming a flange 312 fastening structure. The center of the two support plates is provided with a welded flange 39. The bracket 2 is welded to the outer circumferential surface near the two ends of the same bushing 4 through the welded flange 39.

[0044] The stator fabrication for an electric vehicle hub motor provided by this invention features a support plate with irregularly shaped reinforcing ribs. It is secured using interlocking buckle holes and weight-reducing holes on the support, eliminating the need for traditional riveting. This optimized stator, on the one hand, eliminates the safety hazards of soft, easily deformed, or even detached rivet structures that could cause motor malfunctions, saving material costs. On the other hand, the multi-hole interlocking weight-reducing hole structure, combined with the iron-faced buckle structure, provides good hardness and toughness, resulting in strong support stability, increased clamping surface, greater clamping force, and high strength from the multi-ribbed, irregularly shaped support. Furthermore, it enhances stator manufacturing efficiency, ensures product consistency, and improves manufacturing precision, thereby increasing motor energy conversion efficiency and optimizing motor performance.

[0045] In this embodiment, the rotor 5 includes a rim 51, a magnetic ring 52, and several permanent magnets 53. The inner ring of the rim 51 is fixed to the outer circumferential surface of the magnetic ring 52 by welding. The permanent magnets 53 are evenly distributed and pasted on the inner circumferential surface of the magnetic ring 52 with alternating north and south magnetic poles. The rim 51 has valve core mounting holes 54. In this embodiment, the stator 1 has a structure of 48 slots and 26 pairs of permanent magnets 53, that is, the stator 1 has 48 slots and 52 permanent magnet pieces. The iron core 2 has 48 tooth ribs 24 evenly distributed circumferentially, and 48 tooth slots 23 are formed between each adjacent tooth rib 24. The 26 pairs of permanent magnets 53 are cuboids with the same geometric dimensions.

[0046] Specifically, the iron core is formed by stacking stator laminations in a spiral winding manner, and the tooth grooves are formed by the natural unrolling of the stator laminations. The groove opening width satisfies the following relationship with the outer diameter of the iron core, the tooth lip thickness of the iron core, the inner diameter of the iron core, the yoke thickness of the iron core, the number of tooth grooves of the iron core, and the groove opening width of the stator laminations:

[0047] The slot width of the stator lamination = π × [outer diameter of the core - 2 × thickness of the core tooth lip - 2 × α × (inner diameter of the core + thickness of the core yoke)] ÷ number of core teeth + slot width of stator lamination

[0048] Where π is the mathematical constant pi, α ranges from 0.45 to 0.55, and the slot width of the stator laminations ranges from 0 to 2 mm. In this embodiment, α is set to 0.5, and the slot width of the stator laminations is set to 0 mm, resulting in optimal stator performance. This means that only the slots of the stator laminations are punched. It should be noted that the stator laminations referred to in this invention are straight strips of silicon steel sheet, punched to shape, retaining the teeth and yoke of the stator core, with equal width. The dimensions "slot width, core outer diameter, core tooth lip thickness, core inner diameter, core yoke thickness, and stator lamination slot width" are all in millimeters. "π, α, and the number of core teeth" are dimensionless numbers, meaning they are unitless values, and units are not substituted into the formula for calculation.

[0049] The electric vehicle hub motor provided by this invention optimizes the design of the motor's tooth structure, with reasonable tooth and tooth groove design. On the basis of ensuring a reasonable motor magnetic circuit, it optimizes the tooth groove structure of the stacked stator, reduces the motor's tooth torque, improves the motor's positioning accuracy and working efficiency, makes the motor run more smoothly, effectively controls motor vibration and noise, and extends the motor's service life.

[0050] like Figure 6 and Figure 7 As shown, the outer diameter of the iron core 2 is 198-256 mm, preferably 203-204 mm, and even more preferably 203.15-203.8 mm. In this embodiment, the outer diameter of the iron core 2 is 203.4 mm.

[0051] The width B1 of the toothed rib 24 of the iron core 2 is 4-7 mm. Preferably, the width B1 of the toothed rib 24 of the iron core 2 is 6.0-7.0 mm. More preferably, in this embodiment, the width B1 of the toothed rib 24 of the iron core 2 is 6.5 mm.

[0052] The thickness H1 of the yoke 25 of the iron core 2 is 4-6 mm. Preferably, the thickness H1 of the yoke 25 of the iron core 2 is 4.5-5.0 mm. More preferably, in this embodiment, the thickness H1 of the yoke 25 of the iron core 2 is 4.6 mm.

[0053] The inner diameter of the iron core 2 is 157-215mm, preferably 158-161mm, and more preferably 159mm in this embodiment.

[0054] The tooth lip thickness H2 of the iron core 2 is 0.8–2 mm, preferably 0.9–1.2 mm, and more preferably, in this embodiment, the tooth lip thickness H2 is 0.9 mm. In this embodiment, the tooth lip thickness H2 of the iron core 2 refers to the distance between the projections of the upper and lower edges of the tooth lip onto the center line of the stator tooth where the tooth lip is located.

[0055] The width B2 of the groove 26 of the tooth groove 23 is 1.5-4 mm, preferably 2.2-2.6 mm, and more preferably, in this embodiment, the width B2 of the groove 26 of the tooth groove 23 is 2.49 mm. In this embodiment, the width B2 of the groove 26 of the tooth groove 23 refers to the straight-line distance between the lower edges of the tooth lips of the two tooth ribs 24.

[0056] Compared to similar 10-inch electric vehicle hub motors, the hub motor in this invention features a multi-point, large-hole self-locking structure for its bracket. The support plate of the bracket has multiple reinforcing ribs, resulting in improved motor structural stability, significantly enhanced load-bearing capacity, and improved vibration and impact resistance. It can withstand larger and more frequent impact loads, greatly reducing the motor's failure rate and further improving safety characteristics, making it more adaptable to harsh environments and complex road conditions. Furthermore, compared to similar motors, the Hall effect span of this invention is shortened, effectively reducing the impact of Hall element positioning accuracy on motor performance. In addition, the optimized tooth rib and slot structure optimizes the motor's magnetic circuit, reducing temperature rise, increasing the effective area of ​​the tooth slots, improving the slot fill factor, and allowing more copper wire windings to be placed within the slots, thus increasing the motor's power density and operating efficiency.

[0057] The comparison shows that after the structural optimization of the hub motor for this electric vehicle, the cogging torque of the motor is significantly reduced, the motor efficiency is improved, the load capacity of the motor is significantly enhanced, its structural stability is guaranteed, the safety stability and motor output performance are greatly improved, the motor power is increased, the short-term overload tolerance is strengthened, and the production efficiency is improved and the motor failure rate is significantly reduced after the effective optimization of the motor process.

[0058] Example 2:

[0059] The technical solution in this embodiment is mostly the same as that in embodiment 1. This embodiment only describes the different parts in detail, and the parts that are the same as those in embodiment 1 will not be described again.

[0060] Specifically, the iron core is formed by stacking stator laminations in a spiral winding manner, and the tooth grooves are formed by the natural unrolling of the stator laminations. The groove opening width satisfies the following relationship with the outer diameter of the iron core, the tooth lip thickness of the iron core, the inner diameter of the iron core, the yoke thickness of the iron core, the number of tooth grooves of the iron core, and the groove opening width of the stator laminations:

[0061] The slot width of the stator lamination = π × [outer diameter of the core - 2 × thickness of the core tooth lip - 2 × α × (inner diameter of the core + thickness of the core yoke)] ÷ number of core teeth + slot width of stator lamination

[0062] Where π is the mathematical constant pi, α ranges from 0.45 to 0.55, and the slot width of the stator laminations ranges from 0 to 2 mm. In this embodiment, α is set to 0.5, and the slot width of the stator laminations is set to 0 mm, resulting in optimal stator performance. This means that only the slots of the stator laminations are punched. It should be noted that the stator laminations referred to in this invention are straight strips of silicon steel sheet, punched to shape, retaining the teeth and yoke of the stator core, with equal width. The dimensions "slot width, core outer diameter, core tooth lip thickness, core inner diameter, core yoke thickness, and stator lamination slot width" are all in millimeters. "π, α, and the number of core teeth" are dimensionless numbers, meaning they are unitless values, and units are not substituted into the formula for calculation.

[0063] like Figure 6 and Figure 7 As shown, the outer diameter of the iron core 2 is 198-256 mm, preferably 206.4-207.5 mm, and more preferably, in this embodiment, the outer diameter of the iron core 2 is 206.85 mm.

[0064] The width B1 of the toothed rib 24 of the iron core 2 is 4 to 7 mm, preferably 6.5 to 7.0 mm, and even more preferably 6.7 mm.

[0065] The thickness H1 of the yoke 25 of the iron core 2 is 4 to 6 mm. Preferably, the thickness H1 of the yoke 25 of the iron core 2 is 4.5 to 5.3 mm. More preferably, in this embodiment, the thickness H1 of the yoke 25 of the iron core 2 is 5 mm.

[0066] The inner diameter of the iron core 2 is 157-215mm, preferably 158-162mm, and more preferably 161.5mm in this embodiment.

[0067] The tooth lip thickness H2 of the iron core 2 is 0.8–2 mm, preferably 0.9–1.2 mm, and more preferably, in this embodiment, the tooth lip thickness H2 is 0.9 mm. In this embodiment, the tooth lip thickness H2 of the iron core 2 refers to the distance between the projections of the upper and lower edges of the tooth lip onto the center line of the stator tooth where the tooth lip is located.

[0068] The width B2 of the groove 26 of the tooth groove 23 is 1.5-4 mm, preferably 2.4-2.6 mm, and more preferably, in this embodiment, the width B2 of the groove 26 of the tooth groove 23 is 2.52 mm. In this embodiment, the width B2 of the groove 26 of the tooth groove 23 refers to the straight-line distance between the lower edges of the tooth lips of the two tooth ribs 24.

[0069] Example 3:

[0070] The technical solution in this embodiment is mostly the same as that in embodiment 1. This embodiment only describes the different parts in detail, and the parts that are the same as those in embodiment 1 will not be described again.

[0071] Specifically, the iron core is formed by stacking stator laminations in a spiral winding manner, and the tooth grooves are formed by the natural unrolling of the stator laminations. The groove opening width satisfies the following relationship with the outer diameter of the iron core, the tooth lip thickness of the iron core, the inner diameter of the iron core, the yoke thickness of the iron core, the number of tooth grooves of the iron core, and the groove opening width of the stator laminations:

[0072] The slot width of the stator lamination = π × [outer diameter of the core - 2 × thickness of the core tooth lip - 2 × α × (inner diameter of the core + thickness of the core yoke)] ÷ number of core teeth + slot width of stator lamination

[0073] Where π is the mathematical constant pi, α ranges from 0.45 to 0.55, and the slot width of the stator laminations ranges from 0 to 2 mm. In this embodiment, α is set to 0.5, and the slot width of the stator laminations is set to 0 mm, resulting in optimal stator performance. This means that only the slots of the stator laminations are punched. It should be noted that the stator laminations referred to in this invention are straight strips of silicon steel sheet, punched to shape, retaining the teeth and yoke of the stator core, with equal width. The dimensions "slot width, core outer diameter, core tooth lip thickness, core inner diameter, core yoke thickness, and stator lamination slot width" are all in millimeters. "π, α, and the number of core teeth" are dimensionless numbers, meaning they are unitless values, and units are not substituted into the formula for calculation.

[0074] like Figure 6 and Figure 7 As shown, the outer diameter of the iron core 2 is 198-256 mm, preferably 206.4-207.5 mm, and more preferably, in this embodiment, the outer diameter of the iron core 2 is 206.85 mm.

[0075] The width B1 of the toothed rib 24 of the iron core 2 is 4 to 7 mm, preferably 6.5 to 7.0 mm, and even more preferably 6.7 mm.

[0076] The thickness H1 of the yoke 25 of the iron core 2 is 4 to 6 mm. Preferably, the thickness H1 of the yoke 25 of the iron core 2 is 4.5 to 5.3 mm. More preferably, in this embodiment, the thickness H1 of the yoke 25 of the iron core 2 is 4.75 mm.

[0077] The inner diameter of the iron core 2 is 157-215mm, preferably 158-162mm, and more preferably 159mm in this embodiment.

[0078] The tooth lip thickness H2 of the iron core 2 is 0.8–2 mm, preferably 0.9–1.2 mm, and more preferably, in this embodiment, the tooth lip thickness H2 is 0.95 mm. In this embodiment, the tooth lip thickness H2 of the iron core 2 refers to the distance between the projections of the upper and lower edges of the tooth lip onto the center line of the stator tooth where the tooth lip is located.

[0079] The width B2 of the groove 26 of the tooth groove 23 is 1.5-4 mm, preferably 2.4-2.6 mm, and more preferably, in this embodiment, the width B2 of the groove 26 of the tooth groove 23 is 2.7 mm. In this embodiment, the width B2 of the groove 26 of the tooth groove 23 refers to the straight-line distance between the lower edges of the tooth lips of the two tooth ribs 24.

[0080] Example 4:

[0081] The technical solution in this embodiment is largely the same as that in Embodiment 1. This embodiment only details the differences, while the parts that are the same as those in Embodiment 1 will not be repeated. In this embodiment, the stator structure is selected as either a 54-slot structure with 24 pairs of permanent magnets or a 54-slot structure with 30 pairs of permanent magnets. Preferably, this embodiment selects the 54-slot structure with 24 pairs of permanent magnets.

[0082] In this embodiment, a plurality of Hall slots are provided at the same axial end of the iron core 2. The Hall slots are close to the outer circumferential surface of the iron core 2 and are distributed circumferentially. Among the Hall slots, there is at least one slot Hall slot 21 and two toothed Hall slots 22. The center of the slot Hall slot 21 is located on the symmetrical center line of the toothed slot 23. The slot Hall slot 21 is located at the slot 26 and forms a cavity with the internal component of the slot. The two toothed Hall slots 22 are respectively located on the toothed ribs 24 on both sides of the slot Hall slot 21, and are in the same axial projection plane. The center line connecting the center of the two toothed Hall slots 22 and the center of the iron core 2 forms the same symmetrical angle β with the symmetrical center line of the toothed slot 23 where the slot Hall slot 21 is located. The value of β is in the range of 9.5 degrees to 15.5 degrees, preferably in the range of 9.7 degrees to 10.3 degrees. In this embodiment, the value of β is 10 degrees. It should be noted that the value of β in this invention is an angle value in "degrees".

[0083] Specifically, the iron core is formed by stacking stator laminations in a spiral winding manner, and the tooth grooves are formed by the natural unrolling of the stator laminations. The groove opening width satisfies the following relationship with the outer diameter of the iron core, the tooth lip thickness of the iron core, the inner diameter of the iron core, the yoke thickness of the iron core, the number of tooth grooves of the iron core, and the groove opening width of the stator laminations:

[0084] The slot width of the stator lamination = π × [outer diameter of the core - 2 × thickness of the core tooth lip - 2 × α × (inner diameter of the core + thickness of the core yoke)] ÷ number of core teeth + slot width of stator lamination

[0085] Where π is the mathematical constant pi, α ranges from 0.45 to 0.55, and the slot width of the stator laminations ranges from 0 to 2 mm. In this embodiment, α is set to 0.5, and the slot width of the stator laminations is set to 0 mm, resulting in optimal stator performance. This means that only the slots of the stator laminations are punched. It should be noted that the stator laminations referred to in this invention are straight strips of silicon steel sheet, punched to shape, retaining the teeth and yoke of the stator core, with equal width. The dimensions "slot width, core outer diameter, core tooth lip thickness, core inner diameter, core yoke thickness, and stator lamination slot width" are all in millimeters. "π, α, and the number of core teeth" are dimensionless numbers, meaning they are unitless values, and units are not substituted into the formula for calculation.

[0086] like Figure 6 and Figure 7 As shown, the outer diameter of the iron core 2 is 203-209 mm, preferably 203-203.5 mm, and even more preferably 203.1-203.3 mm. In this embodiment, the outer diameter of the iron core 2 is 203.2 mm.

[0087] The width B1 of the toothed rib 24 of the iron core 2 is 5.0 to 7.9 mm. Preferably, the width B1 of the toothed rib 24 of the iron core 2 is 5.2 to 5.5 mm. More preferably, the width B1 of the toothed rib 24 of the iron core 2 is 5.3 mm.

[0088] The thickness H1 of the yoke 25 of the iron core 2 is 3.5 to 5.8 mm, preferably 4.0 to 4.5 mm, and even more preferably 4.3 mm.

[0089] The inner diameter of the iron core 2 is 157-168 mm, preferably 158-162 mm, and even more preferably 159 mm.

[0090] The tooth lip thickness H2 of the iron core 2 is 0.8-1.5 mm, preferably 0.9-1.2 mm, and even more preferably 0.9 mm. In this embodiment, the tooth lip thickness H2 of the iron core 2 refers to the distance between the projections of the upper and lower edges of the tooth lip onto the center line of the stator tooth where the tooth lip is located.

[0091] The width B2 of the groove 26 of the tooth groove 23 is 1.9-3 mm, preferably 2.2-2.4 mm, and more preferably 2.2 mm. In this embodiment, the width B2 of the groove 26 of the tooth groove 23 refers to the straight-line distance between the lower edges of the tooth lips of the two tooth ribs 24.

[0092] Figure 10 This is a performance comparison curve table of a motor using the stator of the electric vehicle hub motor of the present invention and an existing hub motor. The curves in the table show the superior performance of the technical solution described in the present invention.

[0093] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A hub motor for an electric vehicle, comprising a stator, a rotor, a connecting shaft, and a Hall effect assembly, wherein the Hall effect assembly is installed in a Hall effect slot of the stator, the stator is circumferentially positioned with respect to the connecting shaft, the rotor is sleeved on the outside of the stator, the stator comprises an iron core and a bracket, the bracket is fastened together by two support plates, the edges of the support plates extending outwards in a circumferential direction toward the opposite side of the abutting surfaces, the iron core comprises toothed ribs, a yoke, and toothed grooves, and the iron core is fixed to the outer circumferential surface of the bracket, characterized in that... The iron core is formed by stacking stator laminations in a spiral winding manner, and the tooth groove is formed by unrolling the stator laminations; The slot width of the toothed section satisfies the following relationship with the outer diameter of the iron core, the tooth lip thickness of the iron core, the inner diameter of the iron core, the yoke thickness of the iron core, the number of toothed sections of the iron core, and the slot width of the stator lamination: The slot width of the stator lamination = π × [outer diameter of the core - 2 × thickness of the core tooth lip - 2 × α × (inner diameter of the core + thickness of the core yoke)] ÷ number of core teeth + slot width of stator lamination. Where π is the mathematical constant pi, α ranges from 0.45 to 0.55, and the slot width of the stator laminations ranges from 0 to 2 mm. The iron core has several Hall slots at the same axial end. These Hall slots are located near the outer circumference of the iron core and are circumferentially distributed. Each Hall slot includes at least one slot opening and two toothed Hall slots. The center of the slot opening Hall slot is located on the symmetrical center line of the toothed slot. The slot opening Hall slot forms a cavity with the element inside the slot. The two toothed Hall slots are located on the toothed ribs on either side of the slot opening Hall slot and are in the same axial projection plane. The lines connecting the centers of the two toothed Hall slots to the center of the iron core form the same symmetrical angle β with the symmetrical center line of the toothed slot where the slot opening Hall slot is located. The iron core has 54 slots with an angle β ranging from 9.7 to 10.3 degrees, 51 slots with an angle β ranging from 10 to 11 degrees, and 36 slots with an angle β ranging from 14.5 to 15.5 degrees. The bracket is fixed by two different disc-shaped first and second support plates fastening each other. The first support plate has several flip-out protrusions distributed circumferentially, and the flip-out protrusions protrude outward toward the side of the first support plate facing each other. The second support plate has several weight-reducing holes, and the weight-reducing holes correspond one-to-one with the flip-out protrusions. The flip-out protrusions pass through the weight-reducing holes they are paired with, and by external force, the outward protrusions of the flip-out protrusions are flipped outward and tightly fastened to the non-facing panel near the inner circle of the weight-reducing hole, forming a flanged fastening structure. The two support plates have welded flanges at their centers, and the bracket is welded to the outer circumferential surface near the two ends of the same bushing through the welded flanges. The support plates have irregularly shaped reinforcing ribs.

2. The hub motor for electric vehicles as described in claim 1, characterized in that, The stator laminations are provided with self-locking grooves, which are located on the yoke or toothed part of the iron core. The self-locking grooves on both sides of the stator laminations have a groove on one side and a protrusion on the other side. When the stator laminations are stacked, the positions and shapes of the grooves and protrusions on the self-locking grooves between adjacent laminations correspond to each other to form a positioning and fastening structure.

3. The hub motor for electric vehicles as described in claim 1, characterized in that, The inner circumferential surface of the iron core is provided with an arc-shaped anti-rotation groove, and the two support plates are provided with arc-shaped outward-protruding anti-rotation ribs on their circumferential surfaces. The anti-rotation ribs and anti-rotation grooves are fitted together to form a circumferential positioning and anti-rotation connection pair.

4. The hub motor for electric vehicles as described in claim 1, characterized in that, A copper wire winding is placed inside the cavity of the tooth groove, and the copper wire winding is wound around the tooth rib in a clockwise or counterclockwise direction.

5. The hub motor for electric vehicles as described in claim 1, characterized in that, The Hall assembly consists of three Hall elements of the same specification soldered onto the same circuit board. The Hall elements are circumferentially distributed on the circuit board and their positions correspond to and match the slot Hall slot and the two toothed Hall slots. The circuit board is laid on both sides and the external wiring solder points are distributed on opposite sides to the Hall elements. The exposed metal contacts of the Hall elements are covered with insulating sleeves.

6. The hub motor for electric vehicles as described in claim 1, characterized in that, The rotor includes a rim, a magnetic ring, and several permanent magnets. The inner ring of the rim is fixed to the outer circumference of the magnetic ring by welding. The permanent magnets are evenly distributed and pasted on the inner circumference of the magnetic ring with alternating north and south poles. The rim has valve core mounting holes.

7. The hub motor for electric vehicles as described in claim 1, characterized in that, The inner diameter of the magnetic ring of the rotor is 205~265mm, the thickness of the magnetic ring is 5~10mm, and the height of the magnetic ring is 30~60mm.

8. The hub motor for electric vehicles as described in claim 1 or 5, characterized in that, The outer diameter of the iron core is 198~256mm, the width of the tooth ribs of the iron core is 4~7mm, the thickness of the yoke of the iron core is 4~6mm, the inner diameter of the iron core is 157~215mm, the groove width of the tooth slot is 1.5~4mm, and the tooth lip thickness of the iron core is 0.8~2mm.

9. The hub motor for electric vehicles as described in claim 6, characterized in that, The thickness of the permanent magnet is 1.8~5mm.

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