Double-stator permanent magnet motor structure

Abstract

The invention discloses a double-stator permanent magnet motor structure, and relates to the technical field of motors. One end of the inner stator shaft is fixed on the motor rear end cover, the other end of the inner stator shaft is suspended, and the motor rear end cover is connected with the casing; the inner stator bracket is fixed on the inner stator shaft; the inner rotor iron core and the outer rotor iron core are respectively fixed on the inner ring and the outer ring of the magnetism isolating ring, and the two ends of the magnetism isolating ring are supported and fixed through the rotor front end cover and the rotor rear end cover; the double-row cylindrical roller bearing is radially arranged between the rotor rear end cover and the inner stator shaft; the cylindrical roller bearing is radially arranged between the rotor front end cover and the motor front end cover, and the motor front end cover is connected with the shell; the deep groove ball bearing is axially arranged between the rotor front end cover and the inner stator shaft; the outer stator iron core is pressed into the heated and expanded casing; and the inner stator iron core is thermally sleeved on the inner stator bracket. Through configuration and arrangement of the three bearings, oil injection and discharge positions are all located outside the motor, the working temperature of the bearings is effectively reduced, and the service life is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and in particular to a dual-stator permanent magnet motor structure. Background Art

[0002] As global energy shortages become increasingly severe and the demand for energy conservation continues to rise, permanent magnet synchronous motors (PMSMs), owing to their high efficiency and high power factor, are gradually replacing traditional asynchronous motors. Applications in industries such as industry, new energy vehicles, and aerospace are placing higher demands on the power density, installation space, operating efficiency, and reliability of PMSMs. To meet these demands, dual-stator PMSMs have emerged. These dual-stator PMSMs feature a compact design, high torque density, and high power, making them suitable for applications with stringent space and performance requirements.

[0003] However, the existing dual-stator permanent magnet motor still has many technical difficulties in structural design:

[0004] 1. Since the inner stator is located inside the rotor, its winding leads are difficult to lead out, affecting the motor assembly and electrical connection reliability.

[0005] 2. The inner stator is enclosed inside the rotor and lacks an effective cooling channel, resulting in excessive temperature rise, affecting the performance and life of the motor.

[0006] 3. Existing technologies mostly use a three-bearing support structure, one of the bearings is located inside the motor, which makes it difficult to fill and drain the bearing with oil. Poor lubrication causes heat and shortens the bearing life. At the same time, the three-bearing structure requires extremely high processing and assembly precision, making it difficult to ensure the straightness of the rotor, which can easily cause uneven air gaps and even bore scanning failures.

[0007] 4. The three-bearing layout increases the axial size of the motor, the support span is too large, the rotor rigidity is insufficient, and the parts processing and assembly process are complicated, the production cycle is long, and the cost is high. Summary of the Invention

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

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

[0010] An inner stator shaft, one end of which is fixed to the rear end cover of the motor and the other end is suspended in the air, and the rear end cover of the motor is connected to the casing;

[0011] An inner stator bracket is fixed on the inner stator shaft;

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

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

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

[0015] A deep groove ball bearing is axially arranged between the front end cover of the rotor and the inner stator shaft;

[0016] The outer stator core is pressed into the casing after heating and expansion;

[0017] The inner stator core is shrink-fitted onto the inner stator bracket.

[0018] As a preferred solution 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 a 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 full contact with the area where the water channel of the inner stator bracket is located, and the baffle is fixed to the end of the inner stator bracket.

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

[0020] Multiple first ribs are staggered to form a continuous cooling channel;

[0021] The second rib is provided between the water channel inlet and the water channel outlet to ensure the one-way flow of cooling water. The water channel inlet is connected to the outlet of the inner cooling channel of the inner stator shaft through a hose, and the water channel outlet is connected to the inlet of the inner cooling channel of the inner stator shaft through a hose.

[0022] The length of the first rib is smaller than that of the second rib, and both ends of the second rib are in close contact with the reinforcement ring of the bracket.

[0023] As a preferred solution of the present invention, the inner rotor core and the outer rotor core are fixed by dovetail grooves on the magnetic isolation ring to limit the circumferential movement of the cores;

[0024] A magnetic steel rotor end plate is provided at both ends of the inner rotor core and the outer rotor core respectively, and one end is axially tightened by passing through the rotor pressure ring through a screw and cooperating with a nut; the magnetic steel rotor end plate at the other end is in close contact with the rotor retaining ring, and the rotor retaining ring is fixed on the magnetic isolation ring to limit the circumferential movement of the inner and outer rotor cores and at the same time play an axial positioning effect.

[0025] As a preferred embodiment of the present invention, the cylindrical roller bearing is supported by the front end cover of the motor, the double-row cylindrical roller bearing sits on the inner stator shaft, and the installation position is close to the fixed end of the inner stator shaft; the deep groove ball is fixed to the suspended end of the inner stator shaft, and 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 to 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 in the radial direction between the deep groove ball bearing and the rotor front end cover to ensure that the deep groove ball bearing is completely free from radial force.

[0026] As a preferred solution of the present invention, a labyrinth seal is formed between the front end cover of the motor and the front end cover of the rotor, and between the rear end of the inner stator shaft and the rear end cover of the rotor by means of mutually cooperating groove structures, and a VD-type sealing ring is added on the outside of the labyrinth seal;

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

[0028] Apply grease to the gap between the labyrinth seal and the groove seal during assembly.

[0029] As a preferred solution of the present invention, key slots are respectively provided on the outer circle of the inner stator bracket and the inner circle of the inner stator core teeth, and the two are positioned by keys; key slots are respectively provided on the inner circle of the housing and the outer circle above the outer stator core teeth, and the two are positioned by keys;

[0030] When the inner stator core and the outer stator core are assembled, the keyway on the outer circle of the inner stator bracket and the keyway on the inner circle of the casing are at a certain angle or collinear. When unloading and connecting, the marked slot numbers and phases of the inner stator core and the outer stator core are matched.

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

[0032] As a preferred solution of the present invention, a water-cooling plate with a built-in one-way water channel is provided between the inner stator core punching sheets. A water-cooling inlet and a water-cooling outlet are provided at both ends of the water-cooling plate 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: it is transported from the water inlet manifold to the water-cooled plate through hoses and water pipes, and after completing heat exchange, it is concentrated and returned to the water outlet manifold; among them, the cooling water of the water inlet manifold comes from the inner cooling channel of the inner stator shaft, while the cooling water of the water outlet manifold returns to the inner cooling channel of the inner stator shaft, thus forming a complete closed-loop circulation cooling system.

[0034] As a preferred solution of the present invention, a fan air inlet is provided on the front end cover of the motor, and a fan air outlet is provided on the rear end cover of the motor; a rotor air inlet is provided on the front end cover of the rotor, and a rotor air 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 web of the inner stator bracket is closed, and the cooling air only passes through the air gap.

[0035] By adopting the above technical solutions, the present invention achieves the following technical benefits: The dual-stator permanent magnet motor proposed in this invention utilizes an innovative structural design, employs efficient water cooling for the inner stator core, and optimizes the inner stator cable lead structure to achieve precise phase alignment between the inner and outer stator cores. Furthermore, the three bearings are configured and arranged so that the oil filling and draining points are located outside the motor, effectively reducing the bearing operating temperature and extending its service life.

[0036] The dual-stator permanent magnet motor proposed in the present invention significantly improves the overall performance of the motor: it increases the ability of the whole machine to withstand radial loads, ensures the straightness of the rotor, reduces the difficulty of assembling the whole machine and processing parts, shortens the construction period, reduces the size of the whole machine, and can use air cooling to dissipate heat from the rotor, thereby improving the operating reliability of the motor and making it particularly suitable for high power density application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments or descriptions of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0038] Figure 1 This is the structural assembly drawing of the dual-stator permanent magnet motor;

[0039] Figure 2 Schematic diagram of the inner stator structure;

[0040] Figure 3 This is a schematic diagram of the water channel of the inner stator bracket;

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

[0042] Figure 5 Assemble the cross-section of the rotor;

[0043] Figure 6 Schematic diagram of the outer stator structure;

[0044] Figure 7 This is a schematic diagram of the internal and external phase comparison of the inner and outer stator cores;

[0045] Figure 8This is the general assembly drawing of the rotor air cooling and the internal stator water plate cooling;

[0046] Figure 9 This is a schematic diagram of the inner stator water plate cooling;

[0047] Figure 10 Schematic diagram of the water cooling plate;

[0048] Figure 11 Schematic diagram of the front and rear end covers of the rotor;

[0049] Figure 12 This is the front and rear end cover diagram of the motor;

[0050] Figure 13 for Figure 1 Enlarged views of points Ⅰ and Ⅱ.

[0051] Explanation of the numbers in the figure: 1. Casing; 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 bracket; 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 wire outlet; 21. Second inner stator wire outlet; 22. Shaft inner cooler Cooling channel; 23. Baffle; 24. Positioning plate; 25. Stator end plate; 26. Stator retaining ring; 27. Screw and nut; 28. Water channel inlet; 29. ​​Water channel outlet; 30. Reinforcement ring; 31. Second strong rib; 32. First strong rib; 33. Magnetic steel rotor end plate; 34. Rotor retaining ring; 35. Rotor pressure ring; 36. Water cooling plate; 37. Heat transfer ring; 38. Water pipe; 39. Water inlet manifold; 40. Rotor air inlet; 41. Rotor air outlet; 42. Fan air inlet; 43. Fan air outlet; 44. VD-type sealing ring; 45. Labyrinth seal; 46. Groove seal. DETAILED DESCRIPTION

[0052] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0053] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0054] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" 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 of the parts and steps, the numerical expressions and the numerical values ​​set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The techniques, methods and equipment known to ordinary technicians in the relevant fields may not be discussed in detail, but where appropriate, the techniques, methods and equipment should be considered as part of the authorization specification. In all examples shown and discussed here, any specific values ​​should be interpreted as being merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, and therefore, once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0056] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "radial, axial, vertical, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

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

[0058] It should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and may encompass internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0059] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present 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 with a key, one end of the inner stator shaft fixed to the motor rear end cover with a bolt, and the other end suspended, and the motor rear end cover is connected to the casing; the inner and outer rotor cores are respectively fixed to the inner and outer rings of the magnetic isolation ring, and the two ends of the magnetic isolation ring are supported and fixed by the rotor front and rear end covers respectively, the rotor rear end cover is radially fixed to the inner stator shaft through a double-row cylindrical roller bearing, the rotor front end cover is radially fixed to the motor front end cover through a cylindrical roller bearing, and the motor front end cover is connected to the casing; the rotor front end cover is axially fixed to the inner stator shaft through a deep groove ball bearing;

[0061] The outer stator core and the casing have an interference fit. The outer stator core is installed into the heated and expanded casing, and the axial positioning of the outer stator core is determined using a tool. After cooling, the casing contracts, securing the outer stator core. During operation, the outer stator core heats up and expands, increasing the interference fit between the casing and the core, making the outer stator core more firmly connected to the casing.

[0062] In this embodiment, the magnetic isolation ring is positioned with the rotor front and rear covers via stoppers and then secured with screws. This allows the front and rear covers to function as output shafts, transmitting the torque generated by the rotor with high transmission efficiency and minimal torque loss. The front and rear covers are radially supported by cylindrical roller bearings and double-row cylindrical roller bearings, respectively, leveraging their high radial load-bearing characteristics to meet high-load operating conditions. Specifically, the front cylindrical roller bearing is supported by the motor front cover, while the rear double-row cylindrical roller bearing is mounted on the inner stator shaft near the fixed end. This arrangement effectively minimizes radial offset caused by radial bending of the cantilever shaft. The two wide-body bearings collaboratively support the rotor front and rear covers, ensuring the magnetic isolation ring's straightness accuracy while avoiding problems such as rotor deflection, uneven air gap, and bore scraping. Compared to traditional self-aligning bearings or tapered bearings that require an interference fit, which are difficult to assemble and require extensive tooling, cylindrical roller bearings and double-row cylindrical roller bearings significantly simplify assembly due to their separate inner and outer rings.

[0063] Deep groove ball bearings are used to achieve axial positioning of the rotor. These bearings are installed at the end of the inner stator shaft. The inner ring is fixed by the shaft shoulder and the first outer cover of the front bearing, while the outer ring is bidirectionally locked by the inner cover of the front bearing and the inner shoulder of the rotor front end cover. Since the rotor is radially supported by two cylindrical bearings, in order to avoid the deep groove ball bearings accidentally bearing radial loads due to assembly errors (their radial load capacity is weak and can easily cause heat, locking and other faults), an appropriate gap is maintained between the radial mating surfaces of the deep groove ball bearings and the rotor front end cover to ensure that the radial load is fully borne by the front and rear cylindrical bearings, thereby eliminating the risk of overloading the deep groove ball bearings. Figure 13 Partial view of center I.

[0064] The bearing system of the present invention has achieved three major technical breakthroughs: First, it adopts an external oil injection and discharge structure, and the oil injection ports and oil discharge ports of the three bearings are all arranged on the outside of the motor, that is, the oil injection channel of the cylindrical roller bearing is arranged on the second outer cover of the front bearing and the front end cover of the motor, and the oil discharge channel is arranged on the second outer cover of the front bearing; the oil injection channel and oil discharge channel of the double-row cylindrical roller bearing are both arranged on the inner stator shaft, the oil injection channel of the deep groove ball bearing is arranged on the first outer cover of the front bearing and the inner stator shaft, and the oil discharge channel is arranged on the first outer cover of the front bearing; the above arrangement is not only convenient for maintenance, but also can effectively reduce the operating temperature of the bearings through the circulation of lubricating oil, and improve the bearing life, which completely solves the disadvantage of the difficulty in lubricating the bearings of traditional double-stator motors, and saves 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 end cover of the motor and the front end cover of the rotor, and between the rear end of the inner stator shaft and the rear end cover of the rotor. Precision groove seals are machined on the inner circumference 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 circumference of the first outer cover of the front bearing, and are filled with high-temperature resistant grease during assembly. Thirdly, VD-type sealing rings are added to the outer surface of the labyrinth seals, creating a triple layer of protection: the first labyrinth seal blocks foreign matter through a circuitous flow channel, the second groove seal works with grease to achieve a dynamic seal, and the third VD-type sealing ring completely isolates the bearing from external contamination. Furthermore, the seals near the bearings do not make contact during rotation, generating no additional frictional heat during operation. The VD-type sealing rings are located away from the bearings, so the minimal heat they generate has no effect on the bearing temperature, effectively improving bearing heat dissipation and reducing bearing temperature rise, completely eliminating the problems of lubricant leakage and the intrusion of external contaminants.

[0065] like Figure 2 As shown, the inner stator bracket is fixed to the inner stator shaft by a key and a shaft with a retaining ring. The inner stator core is heated and shrink-fitted onto the inner stator bracket. Bolts and baffles are used to limit the axial and circumferential displacement of the inner stator core. The positioning plate axially positions the inner stator core to ensure that the core is in full contact with the area where the water channel is located. Finally, the inner stator core is axially tightened using the stator end plate, stator retaining ring, screw and nut.

[0066] like Figure 3 As shown, the inner stator support's water channel is composed of first ribs of equal length and staggered arrangement. The water channel inlet and outlet are separated by second ribs, which are shorter than the second ribs. The ends of the second ribs are in close contact with the support's reinforcement ring. The water channel inlet and outlet are connected to the inner stator shaft's internal cooling channel via hoses, ensuring a continuous supply of circulating water to the inner stator support's water channel. This ensures sufficient water cooling of the inner stator, reduces temperature rise, and improves the stator's reliability and performance during operation.

[0067] like Figure 4 As shown in the figure, the inner and outer rotor cores are fixed by dovetail grooves on the magnetic isolation ring to limit the circumferential movement of the cores. The inner and outer rotor retaining rings are fixed to the magnetic isolation ring with bolts to limit the circumferential movement of the inner and outer rotor cores and also play an axial positioning role. Finally, the inner and outer rotor magnetic steel end plates, inner and outer rotor pressure rings and screw nuts are used to axially tighten the inner and outer rotor cores. The dovetail grooves, inner and outer rotor cores and magnetic steel local structure are shown in the figure. Figure 5 shown.

[0068] like Figure 2 、 Figure 6As shown, keyway positioning is used to achieve the alignment of the inner and outer stator cores. The specific implementation method is: a positioning keyway is processed on the outer circle of the inner stator bracket and the inner circle of the root of the inner stator core tooth, and a keyway is also opened at the corresponding position of the inner circle of the casing and the outer circle of the tooth top of the outer stator core. During assembly, the relative angle of the keyway of the inner stator bracket and the keyway of the casing is controlled (collinearity or a specific angle such as 40° can be selected to be arranged), so as to ensure that the inner and outer stator cores form a tooth-to-tooth relative and slot-to-slot alignment relationship. This design has three major technical advantages: first, it realizes strict synchronization of the phases of the inner and outer stator windings to ensure the synergistic effect of the dual stator magnetic fields when power is applied; second, it enables the motor to obtain maximum torque output at the same time under rated conditions; third, it improves the power density of the whole machine by optimizing the electromagnetic coupling efficiency. As Figure 7 As shown, dual-stator motors require synchronous torque output from the inner and outer rotors. The key is ensuring that the slot numbers and phases of the inner and outer stator cores are aligned when wiring. Furthermore, the inner and outer rotors are mechanically connected via the dovetail slots 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 out of sync, forcing one motor to operate under load while not in a no-load state. This not only reduces the overall output torque, but in more serious cases, the dovetail slots of the magnetic isolation ring may break due to uneven force.

[0069] In this embodiment, the inner stator shaft adopts a hollow shaft design. The cables, thermal resistance wires, and other control wires leading from the inner stator windings pass through the first inner stator outlet and into the hollow channel within the shaft. They are then led out through the second inner stator outlet at the rear end of the shaft and connected to the external junction box. This structure allows for internal cable routing, ensuring connection reliability while optimizing the overall spatial layout.

[0070] like Figure 8-10 As shown, the inner stator core can be cooled either through the inner stator bracket's water channels or by using a water-cooling plate combined with a heat-conducting ring. A one-way water channel is welded inside the aluminum water-cooling plate, with inlets and outlets at both ends for continuous water flow. The water-cooling plate is embedded between the core laminations, and a heat-conducting ring is installed at the bottom of the inner stator core. Cooling water flows through the water inlet manifold, via hoses and pipes, into the water-cooling plate, and then flows through the outlet into the water outlet manifold. The cooling water for the water inlet manifold originates from the inner stator shaft's internal cooling channel, while the cooling water for the water outlet manifold returns to the inner stator shaft's internal cooling channel, forming a complete water circulation system to dissipate heat from the core. The heat-conducting ring below effectively balances the core temperature, preventing deformation caused by 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 the rotor. When the temperature of the inner or outer rotor or stator exceeds the specified limit, the fan is activated to cool the rotor interior. The inner stator bracket features a closed intermediate plate design, which concentrates the cooling airflow through the air gap between the inner and outer motors, effectively improving rotor heat dissipation efficiency. This design optimizes the airflow path, reduces the rotor's operating temperature rise, and ensures stable and reliable performance under continuous high-load operation.

[0072] The above axial dimensions of the whole machine are mainly determined by the required core length, stator connection length, coil end length, bearing width, and wire 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 whole machine are reduced.

[0073] This invention effectively addresses technical challenges such as difficulty in routing the inner stator wires, the lack of cooling, complex assembly, and large overall size. The use of conventional components reduces manufacturing complexity, while the bearing configuration and arrangement facilitates oiling, reduces bearing temperature rise, and ensures rotor straightness. Furthermore, the proposed phase alignment of 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 the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A dual-stator permanent magnet motor structure, characterized in that: include: An inner stator shaft, one end of which is fixed to the rear end cover of the motor and the other end is suspended in the air, and the rear end cover of the motor is connected to the casing; An inner stator bracket is fixed on the inner stator shaft; The inner rotor core and the outer rotor core are fixed to the inner ring and the outer ring of the magnetic isolation ring respectively. The two ends of the magnetic isolation ring are supported and fixed by the rotor front cover and the rotor rear cover. Double-row cylindrical roller bearings are radially arranged between the rear end cover of the rotor and the inner stator shaft; A cylindrical roller bearing is radially arranged between the rotor front end cover and the motor front end cover, wherein the motor front end cover is connected to the housing; The deep groove ball bearing is axially arranged between the front end cover of the rotor and the inner stator shaft. The outer stator core is pressed into the casing after heating and expansion; The inner stator core is shrink-fitted onto the inner stator bracket.

2. A dual-stator permanent magnet motor structure according to claim 1, characterized in that: 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 is in full contact with the area where the water channel of the inner stator bracket is located, and the baffle is fixed to the end of the inner stator bracket.

3. A dual-stator permanent magnet motor structure according to claim 2, characterized in that: The water channel of the inner stator support includes: Multiple first ribs are staggered to form a continuous cooling channel; The second rib is provided between the water channel inlet and the water channel outlet to ensure the one-way flow of cooling water. The water channel inlet is connected to the outlet of the inner cooling channel of the inner stator shaft through a hose, and the water channel outlet is connected to the inlet of the inner cooling channel of the inner stator shaft through a hose. The length of the first rib is smaller than that of the second rib, and both ends of the second rib are in close contact with the reinforcement ring of the bracket.

4. The dual-stator permanent magnet motor structure according to claim 1, characterized in that: The inner rotor core and the outer rotor core are fixed by dovetail grooves on the magnetic isolation ring to limit the circumferential movement of the cores; A magnetic steel rotor end plate is provided at both ends of the inner rotor core and the outer rotor core respectively, and one end is axially tightened by passing through the rotor pressure ring through a screw and cooperating with a nut; the magnetic steel rotor end plate at the other end is in close contact with the rotor retaining ring, and the rotor retaining ring is fixed on the magnetic isolation ring to limit the circumferential movement of the inner and outer rotor cores and at the same time play an axial positioning effect.

5. The dual-stator permanent magnet motor structure according to claim 1, characterized in that: 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 the installation position is close to the fixed end of the inner stator shaft; the deep groove ball is fixed to the suspended end of the inner stator shaft, and 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 to 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 in the radial direction between the deep groove ball bearing and the rotor front end cover to ensure that the deep groove ball bearing is completely free from radial force.

6. The dual-stator permanent magnet motor structure according to claim 1, characterized in that: A labyrinth seal is formed between the front end cover of the motor and the front end cover of the rotor, and between the rear end of the inner stator shaft and the rear end cover of the rotor through mutually cooperating groove structures, and a VD-type sealing ring is added on the outside of the labyrinth seal; The inner circumferential surfaces of the front bearing second outer cover, the front bearing inner cover and the rear bearing inner cover, as well as the outer circumferential surface of the front bearing first outer cover are all machined with annular grooves, which together form a multi-stage groove seal; Apply grease to the gap between the labyrinth seal and the groove seal during assembly.

7. The dual-stator permanent magnet motor structure according to claim 1, characterized in that: The inner stator bracket outer circle and the inner stator core teeth inner circle are respectively provided with key slots, and the two are positioned by keys; the inner circle of the housing and the outer circle of the outer stator core teeth are respectively provided with key slots, and the two are positioned by keys; When the inner stator core and the outer stator core are assembled, the keyway on the outer circle of the inner stator bracket and the keyway on the inner circle of the casing are at a certain angle or collinear. When unloading and connecting, the marked slot numbers and phases of the inner stator core and the outer stator core are matched.

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

9. The dual-stator permanent magnet motor structure according to claim 1, characterized in that: A water-cooling plate with a built-in one-way water channel is provided between the inner stator core punching sheets. A water-cooling inlet and a water-cooling outlet are provided at both ends of the water-cooling plate 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: it is transported from the water inlet manifold to the water-cooled plate through hoses and water pipes, and after completing heat exchange, it is concentrated and returned to the water outlet manifold; among them, the cooling water of the water inlet manifold comes from the inner cooling channel of the inner stator shaft, while the cooling water of the water outlet manifold returns to the inner cooling channel of the inner stator shaft, thus forming a complete closed-loop circulation cooling system.

10. The dual-stator permanent magnet motor structure according to claim 1, characterized in that: A fan air inlet is provided on the front end cover of the motor, and a fan air outlet is provided on the rear end cover of the motor; a rotor air inlet is provided on the front end cover of the rotor, and a rotor air 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 web of the inner stator bracket is closed, and the cooling air only passes through the air gap.

Images