Stator assembly with encircling winding structure, manufacturing method and motor

Abstract

The invention belongs to the technical field of motors, and particularly relates to a stator assembly with a surrounding winding structure, a manufacturing method and a motor. The stator assembly with the surrounding type winding structure comprises a stator iron core and a winding, a plurality of inner grooves are uniformly formed in the inner side face of the stator core in the circumferential direction, a plurality of outer grooves are uniformly formed in the outer side face of the stator core in the circumferential direction, and the inner grooves and the outer grooves are in one-to-one correspondence in the radial direction to form a group of winding grooves; a plurality of coils in the winding are wound in the inner groove and the outer groove in a surrounding mode, at least one circle of coil is arranged in any one winding groove, the inner circle of the coil is located in the inner groove in the axial direction, the outer circle of the coil is located in the outer groove in the axial direction, and the two ends, connected with the inner circle and the outer circle, of the coil are located on the two axial end faces of the stator iron core respectively. By optimizing the shape and layout of the winding, reducing the height of the winding, improving the utilization rate of the stator core and improving the heat dissipation performance, the size of the motor is remarkably reduced under the condition that the same power output is ensured.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of electric machines, and particularly relates to a stator assembly with a ring-wound winding structure, a manufacturing method and an electric machine. BACKGROUND

[0002] Traditional electric machine windings usually adopt lap winding or distributed winding. These methods have limitations in improving the power and efficiency of electric machines, especially in terms of volume, heat dissipation and core utilization rate. In the prior art, the winding height is large, the core utilization rate is low, and the heat dissipation is poor, which affects the overall performance of the electric machine and is not conducive to miniaturization. SUMMARY

[0003] The present application aims to provide a stator assembly with a ring-wound winding structure, a manufacturing method and an electric machine.

[0004] A stator assembly with a ring-wound winding structure, the stator assembly with a ring-wound winding structure comprising a stator core and a winding;

[0005] The inner side of the stator core is uniformly provided with a plurality of inner slots in the circumferential direction, and the outer side of the stator core is uniformly provided with a plurality of outer slots in the circumferential direction. The inner slots and the outer slots correspond to each other in the radial direction to form a group of winding slots.

[0006] A plurality of coils in the winding are wound in a ring-wound manner in the winding slots. Any group of winding slots has at least one coil. The inner coil of the coil is located in the inner slot of the winding slot in the axial direction, and the outer coil of the coil is located in the outer slot of the winding slot in the axial direction. The two ends of the coil connected with the inner coil and the outer coil are respectively located on the axial end faces of the stator core.

[0007] Optionally, the radial section of the inner slot is a fan-like structure.

[0008] Optionally, the radial section of the inner slot is a raindrop-like structure with a circular outer side and a sharp inner side.

[0009] Optionally, the radial section of the outer slot is a rectangular structure.

[0010] Optionally, the minimum width of the slot opening of the inner slot and the minimum width of the slot bottom of the outer slot are both 5-15mm.

[0011] Optionally, the minimum thickness of the inner tooth formed between the two adjacent inner slots and the minimum thickness of the outer tooth formed between the two adjacent outer slots are both 2-5mm.

[0012] Optionally, the winding is wound in several winding slots according to the phase separation rule of a single-layer symmetrical three-phase winding. The winding is a single-group three-phase winding, and each three-phase winding has three independent winding units. Each winding unit has two groups of winding slots. The two groups of winding slots are arranged symmetrically. Each group of winding slots has N adjacent groups of winding slots. The coil connection part connecting two adjacent groups of winding slots and the coil bridging part connecting two groups of winding slots are all located on the same axial end face of the stator core.

[0013] Optionally, the winding is wound in several winding slots according to the phase separation rule of a double-layer symmetrical three-phase winding. The winding is a double-layer three-phase winding. The first layer of three-phase winding has three independent winding units. Each winding unit has two winding slot groups. The two winding slot groups are arranged symmetrically. Each winding slot group has N adjacent winding slots. The coil connection part connecting two adjacent winding slot groups and the coil bridging part connecting two winding slot groups are all located on the same axial end face of the stator core. The second layer of three-phase winding adopts the same winding method as the first layer of three-phase winding and is set with a preset number of winding slots offset from the first layer of three-phase winding. The second layer of three-phase winding shares the three conductors that form three winding units in the first layer of three-phase winding.

[0014] Optionally, N is a preset pitch, and the pitch is calculated as follows:

[0015] but

[0016] Where τ represents the pole pitch, Q represents the number of slots in the inner or outer slot, p represents the number of pole pairs in the motor, and y represents the pitch.

[0017] Optionally, the stator assembly with a wraparound winding structure further includes one or more temperature sensors embedded in the ends of the coil.

[0018] A method for manufacturing a stator assembly with a surrounding winding structure, the method comprising:

[0019] The windings are wound in several winding slots according to the phase-separation rules of a single-layer symmetrical three-phase winding, wherein,

[0020] One end of the first wire is left outside any of the inner slots. The other end of the first wire is sequentially inserted axially into the inner slot, across one axial end face of the stator core, axially into the corresponding outer slot, across the other axial end face of the stator core, and axially into the inner slot. Based on the number of coil turns designed for the motor, the first wire is repeatedly wound around the winding slots formed by the inner and outer slots according to the above steps. After repeated winding, the other end of the first wire is located in the outer slot or wound again in the outer slot, thus forming a coil within a set of winding slots, completing a set of winding slots. The first wire is wound in a predetermined direction. The other end of the first wire then crosses the stator core axial direction across the other side end face and enters the inner groove of the adjacent winding slot to begin the winding of the adjacent winding slot. After the winding of several adjacent winding slots is completed, the winding of one winding slot group is completed. The other end of the first wire then crosses the stator core axial direction across several winding slots on the other side end face and enters the inner groove of one winding slot in another winding slot group to begin the winding of the other winding slot group. After the winding of the other winding slot group is completed, the winding of the first winding unit is completed.

[0021] The second and third conductors are wound in the same way as the first conductor to complete the second and third winding units, respectively, thus completing the winding of the three-phase winding. The first conductor, the second conductor, and the third conductor are wound in their respective independent winding slots.

[0022] Optionally, the first conductor, the second conductor, and the third conductor are all made of motor stator enameled wire with an external insulation layer.

[0023] Optionally, the method for manufacturing the stator assembly with the surrounding winding structure further includes:

[0024] After each coil is completed, the axial end of the coil after it has been wrapped is pressed down to prevent the coil end from extending beyond the inner circle of the stator and affecting the ventilation and heat dissipation of the motor.

[0025] Optionally, the winding is a double-layer winding. After the first layer of three-phase winding is completed, the other end of the first conductor is passed over several sets of winding slots on one side of the stator core along a predetermined direction and enters a second-layer winding slot. The position of the second-layer winding slot is a predetermined number of sets away from the winding slot corresponding to one end of the first conductor in the opposite direction of the predetermined direction. The other end of the first conductor is sequentially placed axially into the outer slot of the second-layer winding slot, passes over the other side of the stator core, is placed axially into the inner slot, and passes over the... The stator core is placed axially into the outer slot corresponding to the inner slot. According to the number of coil turns designed for the motor, the first wire is repeatedly wound around the two layers of winding slots according to the above steps. After the repeated winding is completed, the other end of the first wire is located in the outer slot or is wound around the outer slot again, so that two layers of coils are formed in a set of two layers of winding slots, and the winding of a set of two layers of winding slots is completed. The winding method of the other end of the first wire is the same as the winding method of the first layer of three-phase windings, and finally the winding of the first group of winding units in the second layer of three-phase windings is completed.

[0026] The second and third conductors are wound in the same way as the first conductor to complete the winding of the second three-phase winding unit and the third winding unit in the second layer, thus completing the winding of the double-layer winding.

[0027] An electric motor includes a stator assembly, the stator assembly employing the stator assembly with a surrounding winding structure provided by the present invention.

[0028] Optionally, the motor further includes:

[0029] The motor housing has a sealed chamber inside, and the stator assembly is disposed in the sealed chamber.

[0030] The rotor assembly includes a rotor and a shaft that drives the rotor to rotate. The rotor is fitted inside the stator core of the stator assembly. The axial ends of the rotor extend out of the stator core and are connected to the motor housing through bearings. The shaft is fitted inside the rotor. The shaft is a hollow shaft with radial shaft holes that communicate with each other. The radial shaft holes communicate with the stator assembly and the sealed chamber.

[0031] A cooling assembly includes a liquid inlet pump, a liquid inlet and a liquid return port disposed on the motor housing, and a liquid inlet passage disposed inside the motor housing. One end of the liquid inlet pump is connected to the liquid inlet via a liquid inlet pipe, and the other end of the liquid inlet pump is connected to an external medium source via another liquid inlet pipe. One end of the liquid inlet passage is connected to the liquid inlet, and the other end of the liquid inlet passage is connected to the hollow shaft. The liquid return port is connected to the sealed chamber and is connected to the external medium source via a liquid return pipe.

[0032] The cooling medium is pumped from the external medium source through the inlet and the inlet passage into the hollow shaft via the inlet pump. During the rotation of the hollow shaft, the cooling medium inside the hollow shaft is ejected from the radial shaft hole onto the stator assembly, then returns to the return port through the sealed chamber, and finally returns to the external medium source from the return port.

[0033] Optionally, the cooling medium is lubricating oil, fuel oil, or water.

[0034] Beneficial effects: By optimizing the winding shape and layout, reducing the winding height, improving the utilization rate of the stator core, and improving heat dissipation performance, this invention significantly reduces the size of the motor while ensuring the same power output. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of a stator core structure according to the present invention;

[0036] Figure 2 This is a cross-sectional view of the stator assembly of the present invention;

[0037] Figure 3 This is a cross-sectional view of the motor of the present invention;

[0038] Figure 4 This is a schematic diagram of a rotor assembly of the present invention;

[0039] Figures 5A to 5E This is a diagram illustrating the winding process in Embodiment 1 of the present invention;

[0040] Figures 6A to 6D This refers to the winding process of completing a set of winding slots in Embodiment 1 of the present invention;

[0041] Figure 6E for Figure 6D Another perspective diagram. Detailed Implementation

[0042] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, so as to better understand the purpose, features and advantages of the present invention. It should be understood that the embodiments shown in the drawings are not intended to limit the scope of the present invention, but are only for illustrating the essential spirit of the technical solution of the present invention.

[0043] In the following description, certain specific details are set forth for the purpose of illustrating various disclosed embodiments in order to provide a thorough understanding of the various disclosed embodiments. However, those skilled in the art will recognize that embodiments may be practiced without one or more of these specific details. In other instances, well-known apparatuses, structures, and techniques associated with this application may not have been shown or described in detail to avoid unnecessarily obscuring the description of the embodiments.

[0044] Throughout this specification, references to "an embodiment" or "an embodiment" indicate that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Therefore, the appearance of "in an embodiment" or "an embodiment" in various places throughout the specification does not necessarily refer to the same embodiment. Furthermore, a particular feature, structure, or characteristic may be combined in any manner in one or more embodiments.

[0045] In the following description, in order to clearly demonstrate the structure and working method of the present invention, a number of directional terms will be used. However, terms such as "front", "back", "left", "right", "outside", "inside", "outward", "inward", "up", and "down" should be understood as convenient terms and not as limiting terms.

[0046] Reference Figures 1 to 3 This invention provides a stator assembly with a surrounding winding structure, which includes a stator core 10 and a winding 20.

[0047] The stator core 10 is usually an overall ring structure with a certain axial height, which has an inner ring (that is, the inner side of the ring) and an outer ring (that is, the outer side of the ring).

[0048] The stator core 10 has a plurality of inner slots 11 evenly arranged circumferentially on its inner side, and a plurality of outer slots 12 evenly arranged circumferentially on its outer side. Each inner slot 11 and each outer slot 12 corresponds radially inward and outward to form a winding slot. That is, the number of inner slots 11 is the same as the number of outer slots 12, and each inner slot 11 has a corresponding outer slot 12 on its outer side. The inner slots 11 and outer slots 12 are evenly distributed on the inner and outer sides of the stator core 10 to ensure a uniform magnetic field distribution.

[0049] Several coils in winding 20 are wound in a loop manner, specifically a back-wound manner, within the inner slot 11 and the outer slot 12, such as...Figure 5A As shown, any one set of winding slots has at least one coil. The inner coil 31 of the coil is located in the inner slot 11 of the winding slot along the axial direction, and the outer coil 32 of the coil is located in the outer slot 12 of the winding slot along the axial direction. The two ends 33 of the coil connected to the inner coil 31 and the outer coil 32 are respectively located on the two end faces of the stator core 10 along the axial direction.

[0050] The present invention adopts the above-mentioned winding method, in which the two effective sides of each coil are respectively placed in the inner slot and the outer slot that are in a one-to-one correspondence. That is to say, the two effective sides of the same coil are respectively placed between the inner slot 11 and the outer slot 12 that are in a one-to-one correspondence.

[0051] In one embodiment, the radial cross-section of the inner groove 11 is a fan-shaped structure, or the radial cross-section of the inner groove 11 is a raindrop-shaped structure with an outer circle and an inner point.

[0052] The design of this embodiment allows for the arrangement of more inner slots 11 on the inner side of the stator core 10, thereby improving utilization.

[0053] In one embodiment, the radial cross-section of the outer groove 12 is a rectangular structure.

[0054] In one embodiment, the minimum width L1 of the opening of the inner groove 11 and the minimum width L2 of the bottom of the outer groove 12 are both 5mm-15mm.

[0055] The minimum width of the slot opening of the inner slot 11 and the minimum width of the slot bottom of the outer slot 12 can be set according to the motor power and the number of windings.

[0056] In one embodiment, the minimum thickness L3 of the inner teeth formed between two adjacent inner grooves 11 and the minimum thickness L4 of the outer teeth formed between two adjacent outer grooves 12 are both 2mm-5mm to ensure mechanical strength and heat dissipation performance.

[0057] In one embodiment, the winding 20 is wound in several winding slots according to the phase-splitting rule of a single-layer symmetrical three-phase winding. The winding is a single-set three-phase winding, and each three-phase winding has its own independent three sets of winding units. Each set of winding units has two sets of winding slots, which are arranged symmetrically. Each set of winding slots has N adjacent sets of winding slots, such as... Figure 5A As shown, each group of winding slots has 5 adjacent winding slots. The coil connection part 34 connecting two adjacent winding slots and the coil bridging part 35 connecting two winding slots are all located on the same axial end face of the stator core.

[0058] In one embodiment, the winding 20 is wound in several winding slots according to the phase-splitting rule of a double-layer symmetrical three-phase winding. The winding is a double-group three-phase winding. The first group of three-phase windings corresponds to three independent groups of winding units. Each group of winding units has two groups of winding slots. The two groups of winding slots are arranged symmetrically. Each group of winding slots has N adjacent groups of winding slots, such as... Figure 5A As shown, the coil connection part 34 connecting two adjacent sets of winding slots and the coil bridging part 35 connecting two sets of winding slots are both located on the same axial end face of the stator core, as... Figure 5D and 5E As shown, the second layer of three-phase windings adopts the same winding method as the first layer of three-phase windings and is set in a pre-set group of winding slots that are staggered from the first layer of three-phase windings. The second layer of three-phase windings adopts the same winding method as the first layer of three-phase windings and is set in a pre-set group of winding slots that are staggered from the first layer of three-phase windings, and they share the same group of three-phase lead-out busbars.

[0059] In this embodiment, the second-layer three-phase winding is staggered from the first-layer three-phase winding by at least one set of winding slots, meaning they do not overlap. In other words, the second-layer three-phase winding overlaps with the first-layer three-phase winding after being rotated counterclockwise by a preset angle, where this preset angle corresponds to a preset set of winding slots. For example... Figure 5D and 5E As shown, the second-layer three-phase winding is staggered by two sets of winding slots. Taking 30 sets of winding slots as an example, each set of winding slots corresponds to 12 degrees. After rotating the second-layer three-phase winding counterclockwise by 24°, it overlaps with the first-layer three-phase winding. That is, when the second-layer three-phase winding is staggered by two sets of winding slots, the corresponding stagger angle is 24°. In other words, the stagger angle = number of staggered sets × (360° / total number of sets).

[0060] The phase splitting rule principle of the symmetrical three-phase winding of the present invention is as follows:

[0061] 1. Phase separation rules

[0062] The so-called "phase separation rule" refers to the allocation of slots to the three phases A, B, and C according to the phase belt distribution law of the three-phase symmetrical winding.

[0063] The basic principle of three-phase symmetrical windings is that the magnetomotive forces (MMFs) of the three-phase windings are 120° out of phase with each other.

[0064] After the stator slots are distributed circumferentially, the number of slots corresponding to each phase under each magnetic pole should be equal or as balanced as possible;

[0065] Therefore, the phase separation rule is equal to: dividing the stator slots (such as 30 slots) into phase zones according to the rule of "3 phases × number of pole pairs × q (slot / phase / pole)" based on electrical angles, and then allocating the slot positions in sequence.

[0066] Simply put, the phase separation rule is a principle that allocates slots according to phase sequence (A, B, C, with a phase difference of 120° electrical angle) based on electrical angles.

[0067] 2. "Each winding unit has two sets of winding slots, and the two sets of winding slots are arranged symmetrically."

[0068] Winding unit: In this invention, it refers to "the winding portion of a phase within a magnetic pole pair". A magnetic pole pair contains two poles (N pole and S pole), so under a phase band, the phase will have corresponding slot groups under the two adjacent poles; these two slot groups are separated by a pole pitch on the circumference and are mirror images of each other (symmetrical), so it is called "two sets of winding slot groups arranged symmetrically".

[0069] In other words, the “winding unit” of this invention refers to the winding portion of a phase within a magnetic pole pair. Since a magnetic pole pair contains two adjacent poles, the winding unit is composed of two sets of winding slots, located under the two adjacent poles respectively, with their magnetic axis centers separated by one pole pitch, and arranged magnetically symmetrically on the circumference.

[0070] 3. The meaning of N

[0071] Here, N actually refers to the number of slots in the "pitch":

[0072] Definition: The number of slots spanned by the two effective sides of a coil;

[0073] The sentence “each group of winding slots has N adjacent groups of winding slots” can be interpreted as: in a slot group, N consecutive pairs of slots constitute a winding group within a phase band.

[0074] Therefore: N = number of pitch slots, which determines how many slots a single winding spans; each group of winding slots consists of N adjacent slots (that is, N groups or N pairs of slots, with the inner and outer slots corresponding to the position being a pair or a group).

[0075] In summary, the "phase separation rule" described in this invention refers to the allocation of stator slots circumferentially according to phase sequence based on the fundamental principles of three-phase symmetrical windings, ensuring that the three-phase windings differ in electrical angle by 120° sequentially. Under this rule, each phase constitutes a winding unit under each magnetic pole pair. Each winding unit consists of two sets of winding slots located under two adjacent magnetic poles, thus forming a symmetrical arrangement on the stator circumference. Each set of winding slots includes N adjacent winding slots, where N is the coil pitch, i.e., the number of slots spanned by the two effective sides of the coil, which can be designed as full pitch or short pitch (e.g., N=5 in this embodiment).

[0076] Additionally, it should be noted that Figure 5 is a schematic diagram and is not unfolded according to the slot ratio; the 'symmetry' of the two sets of winding slots refers to magnetic symmetry, that is, the centers of their magnetic axes are separated by one pole pitch (approximately 7.5 slots in this embodiment, discretely 7 or 8 slots). The ends of the figure are drawn in a concentrated manner for ease of explanation and are not used to represent the actual number of slots between the slot groups.

[0077] This embodiment adopts a double-layer winding method. The double-layer winding places effective sides in the inner slot and the outer slot respectively, forming a lower layer side and an upper layer side. Each layer has the same distribution rule, so that when there is a problem with the first layer of three-phase winding, the second layer of three-phase winding can be used as a backup.

[0078] This embodiment uses a three-phase distributed winding method to further enhance the stability and efficiency of the motor during operation.

[0079] In one embodiment, N is a preset pitch. The pitch can be determined by recording the original setting value of the motor when the original winding of the motor is removed, and then applying the pitch when updating to the stator assembly of the present invention.

[0080] Of course, the pitch can also be determined by first determining the pole pitch and then calculating the pitch. Specifically, the pitch calculation method is as follows:

[0081] but

[0082] Where τ represents the pole pitch, Q represents the number of slots in the inner slot 11 or the outer slot 12, p represents the number of pole pairs of the motor, and y represents the pitch.

[0083] In one embodiment, the stator assembly having a wraparound winding structure further includes one or more temperature sensors embedded in the coil end 21.

[0084] The temperature sensor can monitor the temperature inside the winding 20. Based on the temperature, the motor controller can implement protection measures, such as reducing speed and current, to ensure safety.

[0085] Preferably, there are multiple temperature sensors, which are evenly arranged at the ends of the coil in the winding 20. The ends of the coil include non-leading ends and leading ends.

[0086] This invention also provides a method for manufacturing a stator assembly with a surrounding winding structure. The method for manufacturing a stator assembly with a surrounding winding structure is as follows:

[0087] The windings are wound in several winding slots according to the phase-separation rules of a single-layer symmetrical three-phase winding, wherein,

[0088] Leave one end of the first wire outside any inner slot, and then place the other end of the first wire into the inner slot in sequence along the axial direction, cross one side of the stator core axial direction, place it into the corresponding outer slot along the axial direction, cross the other side of the stator core axial direction, and place it back into the corresponding inner slot along the axial direction. According to the number of coil turns designed for the motor, use the first wire to repeatedly wind around the winding slot formed by the inner and outer slots in the above steps. After the repeated winding is completed, the other end of the first wire is located in the outer slot or is wound around the outer slot again, thus completing the winding of a set of winding slots. The other end of the first conductor then crosses the stator core axially to the other side end face and enters the inner slot of the adjacent winding slot to begin winding the adjacent winding slot. After completing the winding of several adjacent preset (N, i.e., pitch) winding slots, the winding of one winding slot group is completed. The other end of the first conductor then crosses several (i.e., pole pitch) winding slots from the stator core axially to the other side end face along a preset direction and enters the inner slot of one winding slot in another winding slot group to begin winding the other winding slot group. After completing the winding of the other winding slot group, the winding of the first winding unit is completed. The second conductor and the third conductor are wound in the same way as the first conductor to complete the winding of the second and third winding units, respectively, thus completing the winding of the three-phase winding. The first conductor, the second conductor, and the third conductor are each located in their own independent winding slot.

[0089] In this embodiment, the first conductor, the second conductor, and the third conductor are all made of motor stator enameled wire with an external insulation layer.

[0090] In one embodiment, the winding is a double-layer winding. After the first layer of three-phase winding is completed, the other end of the first conductor is passed over several sets of winding slots on one side of the stator core along a predetermined direction and enters a second-layer winding slot. The position of the second-layer winding slot is a predetermined number of sets away from the winding slot corresponding to one end of the first conductor in the opposite direction of the predetermined direction. The other end of the first conductor is sequentially placed into the outer slot of the second-layer winding slot along the axial direction, passed over the other side of the stator core along the axial direction, placed into the inner slot along the axial direction, and passed over the stator core. One end face along the axial direction is placed into the corresponding outer slot of the inner slot. Based on the number of coil turns designed for the motor, the first wire is repeatedly wound around two layers of winding slots using the steps described above. After repeated winding, the other end of the first wire is either in the outer slot or wound again in the outer slot, thus forming two layers of coils within a set of two-layer winding slots, completing the winding of one set of two-layer winding slots. The other end of the first wire is then wound in the same way as the first layer of three-phase windings, finally completing the winding of the first group of winding units in the second layer of three-phase windings. The second and third wires are then wound using the same method as the first wire to complete the winding of the second and third groups of winding units in the second layer of three-phase windings, thus completing the winding of the double-layer winding.

[0091] In one embodiment, the method for manufacturing the wrap-around motor winding 20 structure further includes:

[0092] After each coil is completed, press down the axial coil end 21 after the coil is wrapped.

[0093] In other words, after a coil is wound, coil ends 21 are formed at both ends along its axial direction. At this time, the coil ends 21 are pressed outward to prevent them from protruding inward, so as to avoid the coil ends 21 from exceeding the inner circle of the stator and affecting the ventilation and heat dissipation of the motor.

[0094] In this embodiment, the stator inner circle refers to the cylindrical surface formed on the inner surface of the stator core, and the diameter of this cylindrical surface is the stator inner diameter. The space within the stator inner circle is reserved for rotor rotation. The rotor rotates at high speed within this space, and there is a pre-set, very small air gap between the rotor and the inner surface of the stator core. After the coil is embedded in the slot of the stator core, its two ends will inevitably extend beyond the two end faces of the core. These coil portions extending beyond the core slot openings are called "coil ends" (or winding ends).

[0095] Before the coil end is pressed, the innermost part of the coil end (the side closest to the motor axis) protrudes radially beyond the virtual cylindrical boundary defined by the inner surface of the stator core (the inner circle of the stator), bulging towards the motor axis. At this point, viewed along the axial direction of the stator core, the diameter of the innermost contour line of the coil end is smaller than the inner diameter of the stator core. This means that the coil end encroaches on the space that the rotor should occupy.

[0096] During motor operation, air (or other cooling medium) needs to flow through the air gap between the stator and rotor, as well as the coil end region, to remove heat. If the coil ends protrude too much inward, the following problems can occur: blocking the air gap inlet / outlet: restricting the smooth entry and exit of cooling airflow into or out of the main air gap channel between the stator and rotor; disrupting the airflow path: creating vortices or dead zones in the end region, reducing heat dissipation efficiency; reducing ventilation area: directly reducing the effective cross-sectional area for cooling airflow; potential mechanical interference: in extreme cases, excessively protruding ends may even rub against rotor components during motor assembly or operation, causing serious accidents.

[0097] Therefore, the coil ends need to be pressed and adjusted to make them avoid the aperture that the rotor needs to rotate through. When the motor is placed horizontally (axis horizontal), pressure can be applied to the coil ends along the direction of gravity (vertically downward). The purpose is to press the innermost part of the coil end (closest to the axis) outward (radially outward) away from the motor axis, so that its profile recedes beyond the cylindrical surface defined by the inner surface of the stator core (stator inner circle).

[0098] The key area to press is the arc segment at the end of the coil closest to the stator core and to the axis. By pressing and shaping, the minimum diameter of the coil end (especially the inner contour) is ensured to be slightly larger than the inner diameter of the stator core. This prevents the coil end from encroaching into the cylindrical space where the rotor rotates, thus providing a smooth passage for airflow (especially the airflow entering the air gap from the end). After pressing, as shown... Figure 2 and Figure 3 As shown, the coil end 21 is formed into a trumpet-shaped structure.

[0099] Reference Figure 3 and Figure 4 The present invention also provides an electric motor, which includes a stator assembly, wherein the stator assembly adopts the stator assembly with a surrounding winding structure provided by the present invention.

[0100] In one embodiment, reference is made to Figure 3 and Figure 4 The motor also includes a motor housing 41, a rotor assembly, and a cooling assembly. The rotor assembly includes a rotor 42 and a shaft 43 that drives the rotor 42 to rotate. The cooling assembly includes a liquid inlet pump, a liquid inlet 44 and a liquid return port 45 disposed on the motor housing 41, and a liquid inlet passage 46 disposed inside the motor housing 41.

[0101] A sealed chamber 411 is provided inside the motor housing 41, and the stator assembly is disposed in the sealed chamber 411.

[0102] The rotor 42 is fitted inside the stator core 10 of the stator assembly. The two axial ends of the rotor 42 extend out of the stator core 10 and are connected to the motor housing 41 through the bearing 47. The rotating shaft 43 is fitted inside the rotor 42. The rotating shaft 43 is a hollow shaft with radial shaft holes that are connected inside and outside. The radial shaft holes are connected to the stator assembly and the sealed chamber 411.

[0103] One end of the inlet pump is connected to the inlet port 44 via an inlet pipe, and the other end of the inlet pump is connected to an external medium source via another inlet pipe. One end of the inlet passage is connected to the inlet port 44, and the other end of the inlet passage is connected to the hollow shaft. The return port 45 is connected to the sealed chamber 411, and the return port 45 is connected to the external medium source via a return pipe.

[0104] The cooling medium is pumped from an external medium source into the hollow shaft through the inlet 44 and the inlet passage by the inlet pump. During the rotation of the hollow shaft, the cooling medium inside the hollow shaft is ejected from the radial shaft hole to the stator assembly, and then returns to the return port 45 through the sealed chamber 411, and then returns to the external medium source from the return port 45.

[0105] In this embodiment, the stator core 10 is cooled by introducing a cooling medium through a hollow shaft.

[0106] In one embodiment, the cooling medium is lubricating oil, fuel oil, or water.

[0107] Example 1:

[0108] Taking a three-phase asynchronous motor as an example, its rated power is 150kw, rated voltage is 550V (Y connection), rated speed is approximately 40000rpm (4-pole motor, 2 pairs of poles), and frequency is 1333.33Hz.

[0109] Synchronous speed formula:

[0110]

[0111] but:

[0112]

[0113] Assuming both inner groove 11 and outer groove 12 are 30, then the pole distance... Pitch

[0114] Reference Figures 5A to 5C The method for manufacturing a stator assembly with a surrounding winding structure, also known as a winding unwinding method, specifically includes the following steps:

[0115] S1, refer to Figure 5A and Figure 6A One end of the first wire U1 remains outside the inner groove 11a, while the other end of the first wire U1 is inserted axially into the inner groove 11a. At this point, a section U1a of the first wire U1 is embedded in the inner groove 11a. (Refer to...) Figure 6B The other end of the first conductor U1 is bent across one axial end face of the stator core 10 and placed axially into the outer groove 12a corresponding to the inner groove 11a. At this time, a section U1b of the first conductor U1 is embedded in the outer groove 12a. (Refer to...) Figure 6C The other end of the first conductor U1 is bent across the stator core 10 and placed back into the inner slot 11a along the axial direction. At this time, a section U1c of the first conductor U1 is embedded in the inner slot 11a, and a coil is wound on a set of winding slots formed by the inner slot 11a and the outer slot 12a. According to the number of coil turns designed for the motor, the first conductor U1 is wound around the winding slots formed by the inner and outer slots in the above steps. For example, in this embodiment, refer to Figure 6D The other end of the first conductor U1 is bent across one axial end face of the stator core 10 and placed axially into the outer slot 12a corresponding to the inner slot 11a. At this time, a section U1d of the first conductor U1 is embedded in the outer slot 12a, completing the winding of one set of winding slots. It can be seen that the first conductor U1 has undergone two rounds of winding within the set of winding slots formed by the inner slot 11a and the outer slot 12a, meaning that the coil formed on one set of winding slots has two turns. (Refer to...)Figure 6D and Figure 6E The other end of the first conductor U1 then crosses the stator core 10 in a counterclockwise direction across the other end face 10a and enters the inner slot 11b of the adjacent winding slot to begin the same two-loop winding process as the adjacent winding slot. At this time, a section U1e of the first conductor U1 is embedded in the inner slot 11b. After completing the winding of five adjacent winding slots, the winding of one winding slot group is completed. From Figure 5A It can be seen that the five adjacent winding slots are wound in a counterclockwise direction, so the winding direction of the remaining coils is also counterclockwise. Of course, they can also be wound in a clockwise direction, in which case the winding direction of the remaining coils is also clockwise. The other end of the first conductor U1 then crosses the ten winding slots on the other side end face 10a of the stator core axial direction in a counterclockwise direction and enters the inner slot 11c of one winding slot in another winding slot group to begin the winding of the other winding slot group. After completing the winding of the other winding slot group, the winding of the first winding unit is completed. Ten winding slots are determined because there are a total of 30 winding slots. One winding slot group occupies 5 winding slots, so the other winding slot group also occupies 5 winding slots. Since the two winding slot groups are symmetrical, (30-2*5) / 2 is 10 groups.

[0116] The second wire is wound using the same winding method as the first wire to complete the second set of winding units. Specifically,

[0117] S2, refer to Figure 5B Starting from inner slot 11a, counting clockwise to the fifth (pitch) inner slot 11a′, one end of the second conductor V1 remains outside inner slot 11a′. The other end of the second conductor V1 is sequentially placed axially into inner slot 11a′, across one side of the stator core 10 axially, into the corresponding outer slot 12a′, across the other side of the stator core 10 axially, into inner slot 11a′, across one side of the stator core 10 axially, and into the corresponding outer slot 12a′, completing one set of winding slots. The other end of the second conductor V1 then crosses counterclockwise across the other side of the stator core 10 axially into the inner slot 11b′ of the adjacent set of winding slots, beginning the same two-stage winding process for the adjacent set of winding slots. After completing the winding of five adjacent sets of winding slots, the winding of one set of winding slots is completed. The other end of the second conductor V1 then crosses the ten sets of winding slots on the other side end face 10a of the stator core in a counterclockwise direction and enters the inner slot 11c′ of one set of winding slots in another set of winding slots to begin the winding of another set of winding slots. After the winding of the other set of winding slots is completed, the winding of the second set of winding units is completed.

[0118] The third conductor is wound using the same winding method as the first conductor to complete the third group of winding units. Specifically,

[0119] S3, refer to Figure 5C Starting from the inner groove 11a′, count the fifth (pitch) inner groove 11a″ clockwise. Leave one end of the third conductor W1 outside the inner groove 11a″. The other end of the third conductor W1 is sequentially placed into the inner groove 11a″ along the axial direction, across one side end face of the stator core 10 along the axial direction, into the outer groove 12a″ corresponding to the inner groove 11a″ along the axial direction, across the other side end face 10a of the stator core 10 along the axial direction, into the inner groove 11a″ along the axial direction, across one side end face of the stator core 10 along the axial direction, and into the outer groove 12a″ corresponding to the inner groove 11a″ along the axial direction, thus completing the winding of a set of winding grooves. The other end of the third conductor W1 then crosses the stator core 10 in a counterclockwise direction across the other end face 10a and enters the inner slot 11b″ of the adjacent winding slot to begin the same two-loop winding process. After completing the winding of five adjacent winding slots, the winding of one winding slot group is completed. The other end of the third conductor W1 then crosses the ten winding slots on the other end face 10a of the stator core in a counterclockwise direction and enters the inner slot 11c″ of one winding slot in another winding slot group to begin the winding of another winding slot group. After completing the winding of another winding slot group, the winding of the third winding unit is completed.

[0120] The above completes the winding of a single-layer winding. If the winding is a double-layer winding, the following steps are performed:

[0121] S4, the other end of the first conductor U1 passes through several sets of winding slots on one side of the stator core 10 in a counterclockwise direction and enters the winding slot, which is regarded as the second layer of winding slots. The position of the second layer of winding slots is two sets of winding slots clockwise from the winding slot corresponding to one end of the first conductor U1, as shown in the reference. Figure 5DAt this point, the first conductor, acting as the fourth conductor U2, is sequentially placed axially into the outer slot 12d of the two-layer winding slot, across the other side end face 10a of the stator core 10, axially into the inner slot 11d, across one side end face of the stator core 10, and axially into the corresponding outer slot 12d of the inner slot 11d. This results in the formation of a two-layer coil within a set of two-layer winding slots, completing the winding of a set of two-layer winding slots. It is known that, unlike step S1, the fourth conductor U2 performs a semi-circular winding within the set of winding slots formed by the inner slot 11d and the outer slot 12d. The other end of the fourth conductor U2 then crosses the other side end face 10a of the stator core 10 in a counter-clockwise direction and enters the inner slot 11e of the adjacent set of two-layer winding slots to begin two circular windings in the adjacent set of two-layer winding slots. After completing the winding of five adjacent sets of two-layer winding slots, the winding of a set of two-layer winding slots is completed. The other end of the fourth conductor U2 then crosses the ten sets of two-layer winding slots on the other side end face 10a of the stator core 10 in a counterclockwise direction and enters the inner slot 11f of one set of two-layer winding slots in another set of two-layer winding slots to begin the two windings of the other set of two-layer winding slots. After the winding of the other set of two-layer winding slots is completed, the winding of the first set of winding units in the second layer of three-phase winding is completed.

[0122] S5, the other end of the second conductor V1 passes through several sets of winding slots on one side of the stator core 10 core in a counterclockwise direction and enters the winding slot, which is regarded as the second layer of winding slots. The position of the second layer of winding slots is two sets of winding slots clockwise from the winding slot corresponding to one end of the second conductor V1, as shown in the reference. Figure 5D At this point, the second conductor, acting as the other end of the fifth conductor V2, is sequentially placed axially into the outer slot 12d′ of the two-layer winding slot, across the other side end face 10a of the stator core 10, axially into the inner slot 11d′, across one side end face of the stator core 10, and axially into the corresponding outer slot 12d′ of the inner slot 11d′. This results in the formation of a two-layer coil within a set of two-layer winding slots, completing the winding of a set of two-layer winding slots. It can be seen that, unlike step S2, the fifth conductor V2 performs a semi-circular winding within the set of winding slots formed by the inner slot 11d′ and the outer slot 12d′. The other end of the fifth conductor V2 then crosses the other side end face 10a of the stator core 10 in a counter-clockwise direction and enters the inner slot 11e′ of the adjacent set of two-layer winding slots to begin two circular windings in the adjacent set of two-layer winding slots. After completing the winding of five adjacent sets of two-layer winding slots, the winding of a set of two-layer winding slots is completed. The other end of the fifth conductor V2 then crosses the ten sets of two-layer winding slots on the other side end face 10a of the stator core 10 in a counterclockwise direction and enters the inner slot 11f′ of one set of two-layer winding slots in another set of two-layer winding slots to begin the two windings of the other set of two-layer winding slots. After the winding of the other set of two-layer winding slots is completed, the winding of the second set of winding units in the second layer of three-phase winding is completed.

[0123] S6, the other end of the third conductor W1 passes through several sets of winding slots on one side of the stator core 10 in a counterclockwise direction and enters the winding slot, which is regarded as the second layer of winding slots. The position of the second layer of winding slots is two sets of winding slots clockwise from the winding slot corresponding to one end of the third conductor W1, as shown in the reference. Figure 5D At this time, the third conductor, as the other end of the sixth conductor W2, is sequentially placed into the outer slot 12d″ of the two-layer winding slot along the axial direction, across the other end face 10a of the stator core 10 along the axial direction, into the inner slot 11d″ along the axial direction, across the end face of the stator core 10 along the axial direction, and into the outer slot 12d″ corresponding to the inner slot 11d″ along the axial direction, so that a two-layer coil is formed in a set of two-layer winding slots, and the winding of a set of two-layer winding slots is completed. At this time, it can be seen that, unlike step S3, the sixth conductor W2 has performed a semi-circular winding in a set of winding slots formed by the inner slot 11d″ and the outer slot 12d″. The other end of the sixth conductor W2 then crosses the stator core 10 along the opposite end face 10a in a counterclockwise direction and enters the inner slot 11e″ of another adjacent set of two-layer winding slots to begin two-way winding of the adjacent set of two-layer winding slots. After completing the winding of five adjacent sets of two-layer winding slots, the winding of one set of two-layer winding slots is completed. The other end of the sixth conductor W2 then crosses the ten sets of two-layer winding slots on the opposite end face 10a of the stator core 10 in a counterclockwise direction and enters the inner slot 11f″ of one set of two-layer winding slots in another set of two-layer winding slots to begin two-way winding of the other set of two-layer winding slots. After completing the winding of the other set of two-layer winding slots, the winding of the third set of winding units in the second layer of three-phase winding is completed.

[0124] This resulted in the completion of the double-layer winding, such as... Figure 5E As shown, since the first and second layers share three conductors and adopt the above winding method, the ends of each conductor are located on the same side of the stator core 10 axis, that is, on the other side of the stator core 10 axis, which facilitates the layout and wiring of each line.

[0125] The preferred embodiments of the present invention have been described in detail above. However, it should be understood that after reading the above teachings, those skilled in the art can make various alterations or modifications to the present invention. These equivalent forms also fall within the scope defined by the appended claims.

Claims

1. A stator assembly with a surrounding winding structure, characterized in that, The stator assembly with a surrounding winding structure includes a stator core and windings; The inner side of the stator core is uniformly provided with several inner grooves along the circumference, and the outer side of the stator core is uniformly provided with several outer grooves along the circumference. The inner grooves and the outer grooves are radially corresponding one-to-one to form a set of winding grooves. The winding consists of several coils wound in the winding slots in a loop manner. Each group of winding slots has at least one coil turn. The inner coil of the coil is located in the inner slot of the winding slot along the axial direction, and the outer coil is located in the outer slot of the winding slot along the axial direction. The two ends of the coil connected to the inner and outer coils are located on the axial end faces of the stator core.

2. The stator assembly with a surrounding winding structure as described in claim 1, characterized in that, The radial cross-section of the inner groove is a fan-shaped structure; or, the radial cross-section of the inner groove is a raindrop-shaped structure with an outer circle and an inner point. And / or, the radial cross-section of the outer groove is a rectangular structure; And / or, the minimum width of the inner groove opening and the minimum width of the outer groove bottom are both 5mm-15mm; And / or, the minimum thickness of the inner teeth formed between two adjacent inner grooves and the minimum thickness of the outer teeth formed between two adjacent outer grooves are both 2mm-5mm.

3. The stator assembly with a surrounding winding structure as described in claim 1, characterized in that, The windings are wound in a number of winding slots according to the phase separation rules of a single-layer symmetrical three-phase winding. The windings are single-group three-phase windings, and each three-phase winding has three independent winding units. Each winding unit has two winding slot groups. The two winding slot groups are arranged symmetrically. Each winding slot group has N adjacent winding slots. The coil connection part connecting two adjacent winding slot groups and the coil bridging part connecting two winding slot groups are all located on the same axial end face of the stator core. Alternatively, the winding is wound in several winding slots according to the phase separation rules of a double-layer symmetrical three-phase winding. The winding is a double-layer three-phase winding. The first layer of three-phase winding has three independent winding units. Each winding unit has two winding slot groups. The two winding slot groups are arranged symmetrically. Each winding slot group has N adjacent winding slots. The coil connection part connecting two adjacent winding slot groups and the coil bridging part connecting two winding slot groups are all located on the same axial end face of the stator core. The second layer of three-phase winding adopts the same winding method as the first layer of three-phase winding and is set with a preset number of winding slots offset from the first layer of three-phase winding. The second layer of three-phase winding shares the three conductors that form three winding units in the first layer of three-phase winding.

4. The stator assembly with a surrounding winding structure as described in claim 3, characterized in that, N is a preset pitch, and the pitch is calculated as follows: but Where τ represents the pole pitch, Q represents the number of slots in the inner or outer slot, p represents the number of pole pairs in the motor, and y represents the pitch.

5. The stator assembly with a surrounding winding structure as described in any one of claims 1 to 4, characterized in that, The stator assembly with a wraparound winding structure also includes one or more temperature sensors embedded in the ends of the coils.

6. A method for manufacturing a stator assembly with a surrounding winding structure as described in any one of claims 1 to 4, characterized in that, The method for manufacturing the stator assembly with the surrounding winding structure includes: The windings are wound in several winding slots according to the phase-separation rules of a single-layer symmetrical three-phase winding, wherein, One end of the first wire is left outside any of the inner slots. The other end of the first wire is sequentially inserted axially into the inner slot, across one axial end face of the stator core, axially into the corresponding outer slot, across the other axial end face of the stator core, and axially into the inner slot. Based on the number of coil turns designed for the motor, the first wire is repeatedly wound around the winding slots formed by the inner and outer slots according to the above steps. After repeated winding, the other end of the first wire is located in the outer slot or wound again in the outer slot, completing the winding of one set of winding slots. The other end of the wire then crosses the stator core axial direction across the other side end face and enters the inner slot of the adjacent winding slot to begin winding the adjacent winding slot. After completing the winding of several adjacent winding slots, the winding of one winding slot group is completed. The other end of the first wire then crosses the stator core axial direction across several winding slots on the other side end face and enters the inner slot of one winding slot in another winding slot group to begin winding the other winding slot group. After completing the winding of the other winding slot group, the winding of the first winding unit is completed. The second and third conductors are wound in the same way as the first conductor to complete the second and third sets of winding units, respectively, thus completing the winding of the three-phase winding. The first conductor, the second conductor, and the third conductor are wound in their respective independent winding slots.

7. The method for manufacturing a stator assembly with a surrounding winding structure as described in claim 6, characterized in that, The method for manufacturing a stator assembly with a wrap-around winding structure further includes pressing the axial coil end after each coil is completed; And / or, the first conductor, the second conductor, and the third conductor are all made of motor stator enameled wire with an external insulation layer; And / or, the winding is a double-layer winding. After the first layer of three-phase winding is completed, the other end of the first conductor is passed over several sets of winding slots on one side of the stator core along a preset direction and enters the second layer of winding slots. The position of the second layer of winding slots is a preset number of sets away from the winding slot corresponding to one end of the first conductor in the opposite direction of the preset direction. The other end of the first conductor is sequentially placed axially into the outer slot of the second layer of winding slots, passed over the other side of the stator core axially, placed axially into the inner slot, and passed over the... The stator core is placed axially into the outer slot corresponding to the inner slot. According to the number of coil turns designed for the motor, the first wire is repeatedly wound around the two layers of winding slots according to the above steps. After the repeated winding is completed, the other end of the first wire is located in the outer slot or is wound around the outer slot again, so that two layers of coils are formed in a set of two layers of winding slots, and the winding of a set of two layers of winding slots is completed. The winding method of the other end of the first wire is the same as the winding method of the first layer of three-phase windings, and finally the winding of the first group of winding units in the second layer of three-phase windings is completed. The second and third conductors are wound in the same way as the first conductor to complete the winding of the second three-phase winding unit and the third winding unit in the second layer, thus completing the winding of the double-layer winding.

8. An electric motor, characterized in that, The motor includes a stator assembly, which employs a stator assembly with a wrap-around winding structure as described in any one of claims 1 to 5.

9. The motor as described in claim 8, characterized in that, The motor also includes: The motor housing has a sealed chamber inside, and the stator assembly is disposed in the sealed chamber. The rotor assembly includes a rotor and a shaft that drives the rotor to rotate. The rotor is fitted inside the stator core of the stator assembly. The axial ends of the rotor extend out of the stator core and are connected to the motor housing through bearings. The shaft is fitted inside the rotor. The shaft is a hollow shaft with radial shaft holes that communicate with each other. The radial shaft holes communicate with the stator assembly and the sealed chamber. A cooling assembly includes a liquid inlet pump, a liquid inlet and a liquid return port disposed on the motor housing, and a liquid inlet passage disposed inside the motor housing. One end of the liquid inlet pump is connected to the liquid inlet via a liquid inlet pipe, and the other end of the liquid inlet pump is connected to an external medium source via another liquid inlet pipe. One end of the liquid inlet passage is connected to the liquid inlet, and the other end of the liquid inlet passage is connected to the hollow shaft. The liquid return port is connected to the sealed chamber and is connected to the external medium source via a liquid return pipe. The cooling medium is pumped from the external medium source through the inlet and the inlet passage into the hollow shaft via the inlet pump. During the rotation of the hollow shaft, the cooling medium inside the hollow shaft is ejected from the radial shaft hole onto the stator assembly, then returns to the return port through the sealed chamber, and finally returns to the external medium source from the return port.

10. The motor as described in claim 9, characterized in that, The cooling medium is lubricating oil, fuel oil, or water.

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