A dual-stator permanent magnet motor structure

Abstract

This invention discloses a dual-stator permanent magnet motor structure, relating to the field of motor technology. The structure includes an inner stator shaft, one end fixed to the rear end cover of the motor, and the other end suspended; the rear end cover is connected to the motor housing. An inner stator support is fixed to the inner stator shaft. An inner rotor core and an outer rotor core are respectively fixed to the inner and outer rings of a magnetic isolation ring, the magnetic isolation ring being supported and fixed at both ends by a rotor front end cover and a rotor rear end cover. A double-row cylindrical roller bearing is radially positioned between the rotor rear end cover and the inner stator shaft. A cylindrical roller bearing is radially positioned between the rotor front end cover and the motor front end cover, the motor front end cover being connected to the motor housing. A deep groove ball bearing is axially positioned between the rotor front end cover and the inner stator shaft. The outer stator core is pressed into the heated and expanded motor housing. The inner stator core is thermally fitted onto the inner stator support. This invention, through the configuration and arrangement of the three bearings, ensures that the oil injection and drainage points are both outside the motor, effectively reducing the bearing operating temperature and extending service life.

Description

Technical Field

[0001] This invention relates to the field of motor technology, specifically to a dual-stator permanent magnet motor structure. Background Technology

[0002] As the global energy shortage worsens and energy conservation demands increase, permanent magnet synchronous motors (PMSMs) are gradually replacing traditional asynchronous motors due to their high efficiency and high power factor. In industries such as manufacturing, new energy vehicles, and aerospace, higher requirements are being placed on the power density, installation space, operating efficiency, and reliability of PMSMs. To meet these demands, dual-stator PMSMs have emerged. These motors employ an inner and outer dual-stator structure, offering advantages such as compact design, high torque density, and high power, making them suitable for applications with stringent space and performance requirements.

[0003] However, existing dual-stator permanent magnet motors still face many technical challenges in structural design:

[0004] 1. Because the inner stator is located inside the rotor, its winding leads are difficult to bring out, which affects the reliability of motor assembly and electrical connection.

[0005] 2. The inner stator is enclosed inside the rotor and lacks an effective cooling channel, resulting in excessive temperature rise, which affects the motor's performance and lifespan.

[0006] 3. Existing technologies mostly adopt a three-bearing support structure, with one bearing located inside the motor. This makes it difficult to inject and drain oil into the bearing, resulting in poor lubrication, overheating, and shortening the bearing's life. At the same time, the three-bearing structure requires extremely high precision in machining and assembly, making it difficult to guarantee the rotor's straightness, which can easily lead to uneven air gaps or even rotor rubbing failures.

[0007] 4. The three-bearing layout increases the axial dimension of the motor, results in an excessively large support span, insufficient rotor rigidity, and complicated parts processing and assembly processes, leading to a long production cycle and high costs. Summary of the Invention

[0008] The purpose of this invention is to provide a dual-stator permanent magnet motor structure to optimize bearing layout, improve heat dissipation, simplify wiring, reduce assembly complexity, and enhance overall reliability and production efficiency.

[0009] To achieve the above objectives, the technical solution of this application is: a dual-stator permanent magnet motor structure, comprising:

[0010] The inner stator shaft has one end fixed to the rear end cover of the motor and the other end suspended in the air. The rear end cover of the motor is connected to the housing.

[0011] Inner stator support, fixed on the inner stator shaft;

[0012] The inner rotor core and the outer rotor core are fixed to the inner and outer rings of the magnetic isolation ring, respectively. The two ends of the magnetic isolation ring are supported and fixed by the rotor front end cover and the rotor rear end cover.

[0013] Double-row cylindrical roller bearings are radially positioned between the rotor rear end cover and the inner stator shaft;

[0014] A cylindrical roller bearing is radially disposed between the rotor front end cover and the motor front end cover, wherein the motor front end cover is connected to the housing;

[0015] Deep groove ball bearings are axially positioned between the rotor front end cover and the inner stator shaft;

[0016] The outer stator core is pressed into the heated and expanded housing;

[0017] The inner stator core is heat-fitted onto the inner stator support.

[0018] As a preferred embodiment of the present invention, stator end plates are respectively provided at both ends of the inner stator core, and one end is axially tightened by a screw passing through the stator retaining ring and cooperating with a nut; a positioning plate is provided between the stator end plate and the baffle at the other end to ensure that the inner stator core and the water channel area of ​​the inner stator support are in complete contact, and the baffle is fixed at the end of the inner stator support.

[0019] In a preferred embodiment of the present invention, the water channel of the inner stator support includes:

[0020] Multiple primary ribs are arranged in an alternating pattern to form a continuous cooling channel;

[0021] The second reinforcing rib is set between the water inlet and the water outlet to ensure unidirectional flow of cooling water. The water inlet is connected to the outlet of the internal cooling channel of the inner stator shaft through a hose, and the water outlet is connected to the inlet of the internal cooling channel of the inner stator shaft through a hose.

[0022] The length of the first reinforcing rib is less than the length of the second reinforcing rib, and both ends of the second reinforcing rib are in close contact with the reinforcing ring of the support.

[0023] As a preferred embodiment of the present invention, the inner rotor core and the outer rotor core are fixed by the dovetail groove on the magnetic isolation ring to restrict the circumferential movement of the core.

[0024] The inner rotor core and the outer rotor core are respectively provided with magnet rotor end plates at both ends. One end is axially tightened by a screw passing through the rotor pressure ring and cooperating with a nut. The magnet rotor end plate at the other end is in close contact with the rotor retaining ring. The rotor retaining ring is fixed on the magnetic isolation ring, which restricts the circumferential movement of the inner and outer rotor cores and also plays an axial positioning role.

[0025] In a preferred embodiment of the present invention, the cylindrical roller bearing is supported by the front end cover of the motor, and the double-row cylindrical roller bearing sits on the inner stator shaft and is installed close to the fixed end of the inner stator shaft; the deep groove ball bearing is fixed to the suspended end of the inner stator shaft, its inner ring is positioned by a shoulder and the first outer cover of the front bearing, one end of the outer ring is fixed by the inner cover of the front bearing, and the other end is fixed to the inner hole shoulder of the rotor front end cover; and there is a certain gap between the deep groove ball bearing and the rotor front end cover in the radial direction to ensure that the deep groove ball bearing does not bear any radial force.

[0026] As a preferred embodiment of the present invention, a labyrinth seal is formed between the front cover of the motor and the front cover of the rotor, and between the rear end of the inner stator shaft and the rear end cover of the rotor, through a groove structure that cooperates with each other, and a VD-type sealing ring is added to the outside of the labyrinth seal.

[0027] The inner circular surfaces of the second outer cover of the front bearing, the inner cover of the front bearing, and the inner cover of the rear bearing, as well as the outer circular surface of the first outer cover of the front bearing, are all machined with annular grooves, which together form a multi-stage groove seal.

[0028] Apply grease to the gaps between labyrinth seals and groove seals during assembly.

[0029] As a preferred embodiment of the present invention, keyways are respectively opened at the outer circle of the inner stator support and the inner circle of the inner stator core teeth, and the two are positioned by keys; keyways are respectively opened at the inner circle of the housing and the outer circle above the outer stator core teeth, and the two are positioned by keys.

[0030] During assembly, the keyway on the outer circle of the inner stator support and the keyway on the inner circle of the housing are at a certain angle or collinear. During the unloading and wiring, the slot numbers and phases marked on the inner stator core and the outer stator core are matched.

[0031] In a preferred embodiment of the present invention, the inner stator shaft is a hollow shaft. The cable, thermal resistance wire and control wire from the inner stator are introduced into the hollow channel of the inner stator shaft through the first inner stator outlet and led out from the second inner stator outlet at the rear end of the shaft to the junction box outside the motor.

[0032] As a preferred embodiment of the present invention, a water-cooled plate with built-in unidirectional water channels is provided between the laminations of the inner stator core. The water-cooled plate has a water-cooling inlet and a water-cooling outlet at both ends to form a continuous water flow channel. A heat-conducting ring is installed at the bottom of the stator core.

[0033] The cooling water circulation path is as follows: the water is transported from the inlet water distributor to the water-cooled plate through hoses and water pipes, and after heat exchange, it is concentrated and returned to the outlet water distributor. The cooling water in the inlet water distributor comes from the internal cooling channel of the inner stator shaft, while the cooling water in the outlet water distributor returns to the internal cooling channel of the inner stator shaft, thus forming a complete closed-loop circulation cooling system.

[0034] As a preferred embodiment of the present invention, a fan inlet is provided on the front end cover of the motor, and a fan outlet is provided on the rear end cover of the motor; a rotor inlet is provided on the front end cover of the rotor, and a rotor outlet is provided on the rear end cover of the rotor; when the temperature is too high, a fan is used for air cooling, and the inner stator support plate is closed, so the cooling air only passes through the air gap.

[0035] The present invention achieves the following technical effects by employing the above technical solutions: The dual-stator permanent magnet motor proposed in this invention adopts an innovative structural design, with its inner stator core using high-efficiency water cooling and an optimized inner stator cable lead-out structure, achieving precise phase correspondence between the inner and outer stator cores. Furthermore, through the configuration and arrangement of three bearings, the oil injection and drainage points are both located outside the motor, effectively reducing the bearing operating temperature and extending its service life.

[0036] The dual-stator permanent magnet motor proposed in this invention significantly improves the overall performance of the motor: it increases the ability of the whole machine to bear radial load, ensures the straightness of the rotor, reduces the difficulty of assembly and component processing, shortens the construction period, reduces the size of the whole machine, allows for air cooling of the rotor, and improves the reliability of motor operation. It is particularly suitable for high power density application scenarios. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is an assembly drawing of a dual-stator permanent magnet motor.

[0039] Figure 2 This is a schematic diagram of the inner stator structure;

[0040] Figure 3 A schematic diagram of the water channel for the inner stator support;

[0041] Figure 4 This is a schematic diagram of the dual-rotor assembly structure;

[0042] Figure 5 This is a cross-sectional view of the rotor assembly.

[0043] Figure 6 This is a schematic diagram of the outer stator structure;

[0044] Figure 7 This is a schematic diagram showing the phase comparison between the inner and outer stator cores.

[0045] Figure 8This is an assembly drawing of the rotor air-cooled system and the inner stator water plate cooling system.

[0046] Figure 9 This is a schematic diagram of the internal stator water plate cooling system.

[0047] Figure 10 This is a schematic diagram of the water-cooled plate.

[0048] Figure 11 This is a schematic diagram of the front and rear end covers of the rotor;

[0049] Figure 12 Diagram of the front and rear end covers of the motor;

[0050] Figure 13 for Figure 1 Enlarged views of sections I and II in the image.

[0051] Explanation of the numbers in the diagram: 1. Housing; 2. Motor rear end cover; 3. Motor front end cover; 4. Inner stator shaft; 5. Double row cylindrical roller bearing; 6. Deep groove ball bearing; 7. Cylindrical roller bearing; 8. Outer stator core; 9. Outer rotor core; 10. Magnetic isolation ring; 11. Inner rotor core; 12. Inner stator core; 13. Inner stator support; 14. Rotor rear end cover; 15. Rotor front end cover; 16. Rear bearing inner cover; 17. Front bearing second outer cover; 18. Front bearing inner cover; 19. Front bearing first outer cover; 20. First inner stator outlet; 21. Second inner stator outlet; 22. Shaft internal coolant. 23. Passageway; 24. Baffle; 25. Positioning plate; 26. Stator end plate; 27. Stator retaining ring; 28. Screw and nut; 29. ​​Water inlet; 30. Water outlet; 31. Reinforcing ring; 32. Second reinforcing rib; 33. First reinforcing rib; 34. Magnet rotor end plate; 35. Rotor retaining ring; 36. Rotor pressure ring; 37. Water cooling plate; 38. Heat conducting ring; 39. Water pipe; 40. Inlet water distributor; 41. Rotor air inlet; 42. Rotor air outlet; 43. Fan air inlet; 44. Fan air outlet; 45. VD type sealing ring; 46. Labyrinth seal; 47. Groove seal. Detailed Implementation

[0052] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0053] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0054] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0055] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0056] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "radial, axial, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0057] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0058] It should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0059] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0060] like Figure 1 As shown, this embodiment provides a dual-stator permanent magnet motor structure, including an inner stator bracket fixed to the inner stator shaft by a key, one end of the inner stator shaft fixed to the rear end cover of the motor by bolts, and the other end suspended, the rear end cover of the motor being connected to the housing; the inner and outer rotor cores are respectively fixed to the inner and outer rings of the magnetic isolation ring, the two ends of the magnetic isolation ring being supported and fixed by the front and rear end covers of the rotor respectively, the rear end cover of the rotor being radially fixed to the inner stator shaft by double-row cylindrical roller bearings, the front end cover of the rotor being radially fixed to the front end cover of the motor by cylindrical roller bearings, the front end cover of the motor being connected to the housing; the front end cover of the rotor being axially fixed to the inner stator shaft by deep groove ball bearings;

[0061] The outer stator core is interference-fitted with the housing. The outer stator core is installed into the heated and expanded housing, and tooling is used to determine the axial positioning of the outer stator core. As the housing cools and contracts, it secures the outer stator core. During operation, the outer stator core heats up and expands, increasing the interference fit between the housing and the core, thus making the outer stator core more firmly connected to the housing.

[0062] In this embodiment, the magnetic isolation ring is positioned with the rotor front and rear end covers via a stop and then fixed with screws, allowing the rotor front and rear end covers to function as output shafts, transmitting the torque generated by the rotor with high efficiency and low torque loss. The rotor front and rear end covers are radially supported by cylindrical roller bearings and double-row cylindrical roller bearings, respectively, fully utilizing their high radial load-bearing characteristics to meet the requirements of heavy load conditions. Specifically, the front cylindrical roller bearing is supported by the motor front end cover, while the rear double-row cylindrical roller bearing is installed on the inner stator shaft near the fixed end. This arrangement effectively suppresses and avoids radial offset caused by radial bending of the cantilever shaft. The two wide-body bearings work together to support the rotor front and rear end covers, ensuring the straightness accuracy of the magnetic isolation ring and avoiding problems such as rotor skew, uneven air gap, and rotor rubbing. Compared with traditional self-aligning bearings or tapered bearings that require interference fit, which are difficult to assemble and require a lot of tooling, the cylindrical roller bearings and double-row cylindrical roller bearings have separate inner and outer rings, which greatly reduces the assembly difficulty of the whole machine.

[0063] A deep groove ball bearing is used for axial positioning of the rotor. This bearing is mounted at the end of the inner stator shaft. The inner ring is fixed by a shoulder and the first outer cover of the front bearing, while the outer ring is locked bidirectionally by the inner cover of the front bearing and the shoulder of the inner bore of the rotor front end cover. Since the rotor is already radially supported by two column bearings, to avoid the deep groove ball bearing accidentally bearing radial loads due to assembly errors (its radial load-bearing capacity is relatively weak and prone to overheating, seizing, and other faults), an appropriate clearance is maintained between the deep groove ball bearing and the radial mating surface of the rotor front end cover. This ensures that the radial load is entirely borne by the two column bearings, thereby eliminating the risk of overload on the deep groove ball bearing. See [link to relevant documentation]. Figure 13 Partial view of I.

[0064] This invention's innovative bearing system achieves three major technological breakthroughs: First, it adopts an external oil injection and drainage structure. The oil injection and drainage ports of all three bearings are located outside the motor. Specifically, the oil injection channel for the cylindrical roller bearing is located on the second outer cover of the front bearing and the front end cover of the motor, while the oil drainage channel is located on the second outer cover of the front bearing. The oil injection and drainage channels for the double-row cylindrical roller bearing are both located on the inner stator shaft, and the oil injection channel for the deep groove ball bearing is located on the first outer cover of the front bearing and the inner stator shaft, while the oil drainage channel is located on the first outer cover of the front bearing. This arrangement not only facilitates maintenance but also effectively reduces the bearing operating temperature and extends bearing life through lubricating oil circulation, completely solving the problem of difficult lubrication in traditional double-stator motor bearings, while also saving the high cost of self-lubricating bearings. Second, it creates a composite sealing structure, such as... Figure 13As shown, multiple labyrinth seals are installed between the front cover of the motor and the front cover of the rotor, and between the rear cover of the inner stator shaft and the rear cover of the rotor. Precision groove seals are machined on the inner circles of the second outer cover of the front bearing, the inner cover of the front bearing, the inner cover of the rear bearing, and the outer circle of the first outer cover of the front bearing, and filled with high-temperature resistant grease during assembly. Thirdly, a VD-type sealing ring is added outside the labyrinth seals, forming triple protection: the first labyrinth seal blocks foreign objects through a meandering flow channel; the second groove seal, in conjunction with the grease, achieves dynamic sealing; and the third VD-type sealing ring completely isolates external contamination. Furthermore, the seals near the bearings do not contact each other during rotation, preventing additional frictional heat generation. The VD-type sealing ring is positioned far from the bearing, so the small amount of heat it generates has no impact on the bearing temperature, effectively improving bearing heat dissipation and reducing bearing temperature rise, completely eliminating the problems of lubricant leakage and external contaminant intrusion.

[0065] like Figure 2 As shown, the inner stator support is fixed to the inner stator shaft by a key and a retaining ring. The inner stator core is heated and fitted onto the inner stator support. Bolts and baffles restrict the axial and circumferential displacement of the inner stator core. The positioning plate axially positions the inner stator core to ensure complete contact between the core and the water channel area. Finally, the inner stator core is axially tightened by the stator end plate, stator retaining ring, screw and nut.

[0066] like Figure 3 As shown, the water channels of the inner stator support are composed of first reinforcing ribs of equal length arranged in an alternating pattern. The inlet and outlet of the water channels are separated by second reinforcing ribs. The length of the first reinforcing ribs is shorter than that of the second reinforcing ribs, and both ends of the second reinforcing ribs are in close contact with the reinforcing rings of the support. The inlet and outlet of the water channels are connected to the internal cooling channels of the inner stator shaft by flexible hoses, ensuring that the external system can provide continuous circulating water to the water channels of the inner stator support. This enables sufficient water cooling of the inner stator, reduces temperature rise, and improves the reliability and performance of the inner stator during operation.

[0067] like Figure 4 As shown, the inner and outer rotor cores are fixed by dovetail grooves on the magnetic isolation rings, restricting the circumferential movement of the cores. The inner and outer rotor retaining rings are bolted to the magnetic isolation rings, further restricting the circumferential movement of the inner and outer rotor cores and also providing axial positioning. Finally, the inner and outer rotor cores are axially tightened using the inner and outer rotor magnet end plates, inner and outer rotor pressure rings, and screw nuts. The dovetail grooves, inner and outer rotor cores, and partial magnet structures are shown below. Figure 5 As shown.

[0068] like Figure 2 , Figure 6As shown, keyway positioning is used to align the inner and outer stator cores. Specifically, a positioning keyway is machined on the outer circle of the inner stator support and the inner circle at the root of the inner stator core teeth. Simultaneously, keyways are also machined on the inner circle of the housing at corresponding positions to the outer circle at the tip of the outer stator core teeth. During assembly, the relative angle between the keyways of the inner stator support and the housing (which can be collinear or a specific angle such as 40°) is controlled to ensure that the inner and outer stator cores form a tooth-to-tooth and slot-to-slot alignment. This design has three major technical advantages: first, it achieves strict synchronization of the phases of the inner and outer stator windings, ensuring the synergistic effect of the dual stator magnetic fields when energized; second, it allows the motor to simultaneously obtain maximum torque output under rated operating conditions; and third, it improves the overall power density by optimizing electromagnetic coupling efficiency. Figure 7 As shown, a dual-stator motor requires synchronous torque output from the inner and outer rotors during operation. The key is that the slot numbers and phases of the inner and outer stator cores must strictly correspond when wiring them. Simultaneously, the inner and outer rotors are mechanically connected via the dovetail groove of the magnetic isolation ring. If the slot numbers and phases of the inner and outer stator cores are not accurately aligned during assembly, the torque output of the inner and outer motors will be asynchronous, forcing one motor to operate under load even when unloaded. This will not only reduce the overall output torque but, in more serious cases, may cause the dovetail groove of the magnetic isolation ring to break due to uneven stress.

[0069] In this embodiment, the inner stator shaft adopts a hollow shaft structure design. The cables, thermal resistance wires, and other control wires led out from the inner stator windings pass through the hollow channel inside the shaft via the first inner stator outlet, and then exit through the second inner stator outlet at the rear end of the shaft to connect to the external junction box. This structure realizes the built-in routing of cables, which not only ensures the reliability of the connection, but also optimizes the overall space layout.

[0070] like Figure 8-10 As shown, the inner stator core can be cooled via water channels in the inner stator support or by using a water-cooled plate combined with a heat-conducting ring. The aluminum water-cooled plate has unidirectional water channels welded inside, with inlet and outlet ports at both ends to ensure continuous water flow. The water-cooled plate is embedded between the core laminations, and a heat-conducting ring is installed at the bottom of the inner stator core. Cooling water enters the water-cooled plate through an inlet water distributor via hoses and pipes, and then flows out to an outlet water distributor. The cooling water in the inlet water distributor comes from the internal cooling channel of the inner stator shaft, while the cooling water in the outlet water distributor flows back to the internal cooling channel of the inner stator shaft, forming a complete circulating water circuit for core cooling. The heat-conducting ring below effectively balances the core temperature and prevents deformation due to uneven heat dissipation.

[0071] like Figure 11-12As shown, air inlet and outlet holes are provided on the front and rear end covers of the motor and rotor. When the temperature of the inner and outer rotors or stator exceeds the standard, the fan is activated to cool the inside of the rotor. The inner stator support adopts a closed intermediate plate design, which concentrates the cooling airflow through the air gap channel of the inner and outer motors, effectively improving the rotor heat dissipation efficiency. This design optimizes the airflow path, reduces the rotor operating temperature rise, and ensures the performance stability and reliability of the motor during continuous high-load operation.

[0072] The axial dimensions of the entire machine are mainly determined by the required core length, stator wiring length, coil end length, bearing width, and outlet space; the radial dimensions are mainly determined by the stator inner and outer diameters, air gap, and rotor inner and outer diameters. The space is compact, and under the same output torque conditions, the axial and radial installation dimensions of the entire machine are reduced.

[0073] This invention effectively solves technical problems such as difficulty in inner stator wiring, inability to cool the inner stator, complex assembly, and large overall size. The use of conventional components reduces processing difficulty, and the bearing configuration and arrangement facilitate convenient lubrication, reduce bearing temperature rise, and ensure rotor straightness. Furthermore, the proposed phase correspondence scheme between the inner and outer stators optimizes motor performance.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A dual-stator permanent magnet motor structure, characterized in that, include: The inner stator shaft has one end fixed to the rear end cover of the motor and the other end suspended in the air. The rear end cover of the motor is connected to the housing. Inner stator support, fixed on the inner stator shaft; The inner rotor core and the outer rotor core are fixed to the inner and outer rings of the magnetic isolation ring, respectively. The two ends of the magnetic isolation ring are supported and fixed by the rotor front end cover and the rotor rear end cover. Double-row cylindrical roller bearings are radially positioned between the rotor rear end cover and the inner stator shaft; A cylindrical roller bearing is radially disposed between the rotor front end cover and the motor front end cover, wherein the motor front end cover is connected to the housing; Deep groove ball bearings are axially positioned between the rotor front end cover and the inner stator shaft; The outer stator core is pressed into the heated and expanded housing; The inner stator core is heat-fitted onto the inner stator support; The inner stator core is provided with stator end plates at both ends, and one end is axially tightened by a screw passing through the stator retaining ring and cooperating with a nut; a positioning plate is provided between the stator end plate and the baffle at the other end to ensure that the inner stator core is in complete contact with the water channel area of ​​the inner stator support, and the baffle is fixed at the end of the inner stator support. The water channels of the inner stator support include: Multiple primary ribs are arranged in an alternating pattern to form a continuous cooling channel; The second reinforcing rib is set between the water inlet and the water outlet to ensure unidirectional flow of cooling water. The water inlet is connected to the outlet of the internal cooling channel of the inner stator shaft through a hose, and the water outlet is connected to the inlet of the internal cooling channel of the inner stator shaft through a hose. The length of the first reinforcing rib is less than the length of the second reinforcing rib, and both ends of the second reinforcing rib are in close contact with the reinforcing ring of the support. The inner rotor core and the outer rotor core are fixed by the dovetail groove on the magnetic isolation ring, which restricts the circumferential movement of the core. The inner rotor core and the outer rotor core are respectively provided with magnet rotor end plates at both ends. One end is axially tightened by a screw passing through the rotor pressure ring and cooperating with a nut. The magnet rotor end plate at the other end is in close contact with the rotor retaining ring. The rotor retaining ring is fixed on the magnetic isolation ring, which restricts the circumferential movement of the inner and outer rotor cores and also plays an axial positioning role. Keyways are respectively opened on the outer circle of the inner stator support and the inner circle of the inner stator core teeth, and the two are positioned by keys; keyways are also opened on the inner circle of the housing and the outer circle of the outer stator core teeth, and the two are positioned by keys. During assembly, the keyway on the outer circle of the inner stator support and the keyway on the inner circle of the housing are at a certain angle or collinear. During the unloading and wiring, the slot numbers and phases marked on the inner stator core and the outer stator core are matched accordingly. A water-cooled plate with built-in unidirectional water channels is provided between the laminations of the inner stator core. The water-cooled plate has a water-cooling inlet and a water-cooling outlet at both ends to form a continuous water flow channel. A heat-conducting ring is installed at the bottom of the stator core. The cooling water circulation path is as follows: the water is transported from the inlet water distributor to the water-cooled plate through hoses and water pipes, and after heat exchange, it is concentrated and returned to the outlet water distributor; the cooling water of the inlet water distributor comes from the internal cooling channel of the inner stator shaft, while the cooling water of the outlet water distributor returns to the internal cooling channel of the inner stator shaft, thus forming a complete closed-loop circulation cooling system. The cylindrical roller bearing is supported by the front end cover of the motor, and the double-row cylindrical roller bearing sits on the inner stator shaft and is installed close to the fixed end of the inner stator shaft. The deep groove ball bearing is fixed to the suspended end of the inner stator shaft. Its inner ring is positioned by the shaft shoulder and the first outer cover of the front bearing. One end of the outer ring is fixed by the inner cover of the front bearing, and the other end is fixed to the inner hole shoulder of the rotor front end cover. There is a certain gap between the deep groove ball bearing and the rotor front end cover in the radial direction to ensure that the deep groove ball bearing does not bear any radial force. The front cover of the motor and the front cover of the rotor, as well as the rear end cover of the inner stator shaft and the rear end cover of the rotor, form a labyrinth seal through a groove structure that cooperates with each other, and a VD type sealing ring is added to the outside of the labyrinth seal. The inner circular surfaces of the second outer cover of the front bearing, the inner cover of the front bearing, and the inner cover of the rear bearing, as well as the outer circular surface of the first outer cover of the front bearing, are all machined with annular grooves, which together form a multi-stage groove seal. Apply grease to the gaps between labyrinth seals and groove seals during assembly.

2. The dual-stator permanent magnet motor structure according to claim 1, characterized in that, The inner stator shaft is a hollow shaft. The cable, thermal resistance wire and control wire from the inner stator are introduced into the hollow channel of the inner stator shaft through the first inner stator outlet, and led out from the second inner stator outlet at the rear end of the shaft to the junction box outside the motor.

3. The dual-stator permanent magnet motor structure according to claim 1, characterized in that, A fan inlet is provided on the front cover of the motor, and a fan outlet is provided on the rear cover of the motor; a rotor inlet is provided on the front cover of the rotor, and a rotor outlet is provided on the rear cover of the rotor; when the temperature is too high, a fan is used for air cooling; the inner stator support plate is closed, and the cooling air only passes through the air gap.

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