Oil-cooled rotor and method of assembly

Abstract

This invention provides an oil-cooled rotor and its assembly method. The oil-cooled rotor includes: a shaft, a rotor core sleeved on the outer periphery of the shaft, and two steel sleeves press-fitted at both ends. The rotor core is composed of at least one first lamination unit, which includes a centrally placed first lamination and an even number of second laminations symmetrically arranged on both sides. The shaft has a central main oil passage and a connecting hole. The inner diameter of the first lamination is larger than the outer diameter of the shaft to form an annular oil passage, which communicates with the connecting hole. Cooling oil flows sequentially through the central main oil passage, the connecting hole, the annular oil passage, and the cooling oil passage composed of oil guide holes of each lamination, and finally flows out uniformly from both ends of the rotor core. This application decouples the assembly phase restriction between the shaft connecting hole and the internal oil passage of the core, eliminating the need for strict circumferential alignment during press-fitting, simplifying the balance disc structure, reducing the number of lamination types, ensuring uniform flow distribution, and greatly facilitating industrialization.

Description

Technical Field

[0001] This invention relates to the field of motor rotors, and more particularly to an oil-cooled rotor and its assembly method. Background Technology

[0002] With the rapid development of new energy drive systems, permanent magnet synchronous motors (PMSMs) play a crucial role in many fields due to their high power density and high efficiency. However, during continuous high-load operation, the internal components of the rotor generate a large amount of heat. If effective heat exchange cannot be achieved in a timely manner, it can easily lead to demagnetization of the magnets, severely affecting the motor's output performance and service life. Therefore, introducing an efficient cooling mechanism has become a core aspect of motor design. Currently, constructing cooling oil circuits inside the rotor for oil cooling, which directly introduces the cooling medium to the heat source center, is widely used in motor thermal management systems and is a key technology for ensuring stable motor operation and overcoming power density bottlenecks.

[0003] Existing rotor oil cooling solutions generally employ a combination of perforated rotor shaft oil inlet and core oil circuits for cooling. However, this existing technology has revealed several limitations in practical applications and manufacturing. First, to achieve the distribution and guidance of the cooling medium flow, existing technologies often require the addition of complex structures such as balance discs or end plates to construct the oil circuit distribution chamber. This not only makes the rotor assembly cumbersome but also increases the overall manufacturing cost and the variety of materials. Second, during the assembly of the rotor shaft and rotor core, the existing structure has extremely stringent requirements for the circumferential phase alignment between the oil outlet hole on the rotor shaft and the internal oil guide hole in the core, greatly increasing the assembly difficulty and making it difficult to meet the needs of large-scale, high-efficiency industrialization. Furthermore, the oil circuit structure formed by the stacked laminations in existing technologies is prone to having fluid dead zones that are not connected to the main flow channels. When the rotor rotates at high speed, the cooling oil stagnating in the dead zones can easily cause cooling compensation and dynamic imbalance problems in the rotor.

[0004] Therefore, how to achieve efficient and stable cooling of oil-cooled rotors while simplifying rotor components has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In order to overcome the above-mentioned technical defects, the purpose of this invention is to provide an oil-cooled rotor and an assembly method thereon.

[0006] This invention discloses an oil-cooled rotor, comprising: a rotating shaft, the rotating shaft having a central main oil passage extending along a first direction inside, and the outer peripheral sidewall of the rotating shaft having several connecting holes communicating with the central main oil passage; the first direction is the axial extension direction of the rotating shaft; A rotor core is sleeved on the outer periphery of a rotating shaft. The rotor core is composed of at least one first lamination unit, which includes one first lamination and an even number of second laminations. The first lamination is located at the center of the first lamination unit, and the even number of second laminations are symmetrically arranged on both sides of the first lamination along a first direction and fixed relative to the first lamination. The first lamination has a first oil guide hole, and the second lamination has a second oil guide hole. The inner diameter of the first lamination is larger than the outer diameter of the rotating shaft, and the first lamination is coaxial with the rotating shaft, so that an annular oil channel is formed between the inner wall of the first lamination and the outer peripheral side of the rotating shaft. The annular oil channel is arranged opposite to and connected to the connecting hole. The first oil guide hole and the second oil guide hole together form multiple cooling oil channels in the first direction, so that the cooling oil flows sequentially through the central main oil channel, the connecting hole, and the annular oil channel, and flows evenly to the cooling oil channels on both sides, and finally flows out from both ends of the rotor core in the first direction. Two steel sleeves are respectively pressed and fitted onto the two ends of the rotor core in the first direction, and are sleeved on the rotating shaft to press and fix the rotor core to the rotating shaft.

[0007] Preferably, in the first lamination unit, the first lamination and the adjacent second lamination are fixedly connected by adhesive bonding; Alternatively, the surface of the first lamination may have protrusions or grooves, and the surface of the second lamination may have grooves or protrusions corresponding to the surface structure of the first lamination, so that the first and second laminations can be snapped together and fixed.

[0008] Preferably, the rotor core includes five, six, seven or eight first lamination units, each of which is staggered and fixed in a first direction, so that coolant flows out through the annular oil channel corresponding to any first lamination, and then flows through the cooling oil channel to both ends of the rotor core in the first direction.

[0009] Preferably, the oil-cooled rotor further includes a second lamination unit, which is formed by stacking and fixing multiple second laminations along a first direction.

[0010] Preferably, the rotor core includes an odd number of first lamination units and second lamination units; wherein, the rotor core includes one first lamination unit and an even number of second lamination units; The first lamination unit is located at the center of the rotor core, and an even number of second lamination units are symmetrically arranged on both sides of the first lamination unit.

[0011] Preferably, the rotor core includes an even number of first lamination units and second lamination units; wherein, the rotor core includes two first lamination units and an even number of second lamination units; Two first lamination units are located at the center of the rotor core, and an even number of second lamination units are symmetrically arranged on both sides of the two first lamination units.

[0012] Preferably, any two adjacent first lamination units, or when the rotor core also includes a second lamination unit, are staggered to achieve a V-shaped segmented skewed pole structure. Using the angular position of the first or second lamination unit on one side of the rotor core in the first direction as the reference zero point, the rotor core is rotated sequentially from the angular positions of the first and / or second lamination units on the other side, with the rotation angle... Configured as: Where j is the position number of the first lamination unit or the second lamination unit in the first direction, j=1,2,...n, and n is the total number of the first lamination units and the second lamination units contained in the rotor core.

[0013] Preferably, when the rotor core also includes a second lamination unit, the angular position offset between the first lamination unit and the second lamination unit, with the angular position of the second lamination located on one side in the first direction as the reference zero point, is 45°.

[0014] The second aspect of this application provides a method for assembling an oil-cooled rotor according to any one of the foregoing embodiments, comprising: The first lamination and the second lamination are stacked and fixed along the first direction to form a first lamination unit; when the rotor core includes a second lamination unit, multiple second laminations are stacked and fixed along the first direction to form a second lamination unit. The first lamination unit, or the first lamination unit and the second lamination unit, are stacked alternately in a preset order along a first direction to form a rotor core, so that a preset skew angle is formed between each lamination unit. Insert the shaft into the rotor core along the first direction and position the shaft axially so that the connecting hole of the shaft is connected to the annular oil passage in the radial direction. Steel sleeves are press-fitted onto both sides of the rotor core in the first direction to press and fix the rotor core to the outer circumference of the shaft.

[0015] Compared with existing technologies, the above technical solution has the following advantages: 1. The oil-cooled rotor provided in this application redefines the internal oil passage structure and distribution method of the rotor. The method of forming oil passages through the opening and stacking of laminations achieves oil conduction along the rotor's axial laminations, eliminating the need for the complex balance disc structure found in existing technologies, thus greatly simplifying the rotor assembly. Cooling oil flows out from the central main oil passage of the shaft via the connecting hole, first entering the annular oil passage naturally formed by the large inner diameter of the first lamination for spatial buffering and uniform distribution, and then entering the cooling oil passage jointly formed by the first and second oil guide holes. Importantly, the existence of the annular oil passage physically decouples the assembly phase restriction between the shaft connecting hole and the internal oil passages of the rotor core, eliminating the need for strict circumferential alignment during shaft press-fitting. Simultaneously, the design of an even number of second laminations symmetrically distributed on both sides of the first lamination unit ensures the uniformity of oil flow to both axial ends from the source, allowing the cooling oil to flow uniformly out from both ends of the rotor core. Furthermore, this solution only requires two different types of laminations, the first lamination and the second lamination, to form corresponding lamination units through phase and combination, thereby realizing the complex cooling oil circuit mentioned above. The number of lamination types is small, which greatly facilitates industrial manufacturing. 2. Regarding the specific configuration and structural stability of the rotor core, this application effectively solves the problem of partial suspension of large-diameter laminations by bonding or snapping the first lamination with the adjacent second lamination. Combined with the magnets on the laminations themselves for auxiliary positioning, it ensures that the lamination unit will not shift during high-speed rotation, fundamentally avoiding dynamic imbalance caused by rotor misalignment. Simultaneously, by introducing a second lamination unit solely responsible for axial airflow and flexibly modularly combining it with the first lamination unit possessing radial oil inlet capability, it can perfectly adapt to motors with different segment designs. Whether it's the absolutely symmetrical single-point oil inlet model constructed for odd-numbered core segments or the dual-center parallel oil inlet area designed for even-numbered core segments, it ensures that the path and resistance of the cooling oil diffusion to both ends are consistent, achieving a high degree of consistency between the cooling rate and the thermal expansion of the material on both sides of the rotor, effectively suppressing thermal deformation. The combination of full-segment oil inlet can break the axial temperature gradient, achieving efficient heat exchange along the entire axial length of the rotor. 3. In terms of optimizing the internal flow channel morphology and balancing electromagnetic performance, the lamination units inside the rotor core are staggered according to preset angles to construct a V-shaped segmented oblique pole structure. This design not only effectively reduces cogging torque and electromagnetic harmonics, but also ensures the continuous flow of the stepped cooling oil path in the V-shaped tortuous state through the reasonable layout of the oil guide holes. Furthermore, by setting preset angular position offsets between adjacent laminations inside the lamination unit, the originally straight channels are transformed into complex stepped labyrinthine oil paths. This staggered stacking continuously cuts and disturbs the cooling oil flow, promoting the transformation from laminar to turbulent flow, increasing the contact area between the cooling oil and the metal, and effectively reducing the fluid dead zone where oil easily accumulates in the gaps between the laminations. While effectively dissipating heat, it also eliminates the potential risk of dynamic imbalance. 4. Based on the above structure, this application also provides a modular assembly method. By pre-assembling and fixing the laminations into independent lamination units externally, and then stacking them alternately at a preset oblique angle, the complex phase control is decentralized to the unit level. When assembling the shaft and rotor core, since the first lamination unit has a pre-fabricated annular oil channel, the operator only needs to complete the axial advancement and positioning of the shaft to naturally achieve radial communication between the shaft connection hole and the annular oil channel. This blind-insertion assembly logic that eliminates circumferential phase alignment completely removes the process bottleneck of rotor shaft hole alignment in the prior art. Combined with the rapid pressing of the steel sleeves at both ends, it significantly reduces the assembly difficulty and manufacturing cost of the production line. Attached Figure Description

[0016] Figure 1 A schematic diagram of the external structure of the oil-cooled rotor provided in this application; Figure 2 A schematic diagram of the external structure of the first lamination unit of the oil-cooled rotor provided in this application; Figure 3 A cross-sectional view of the first lamination unit of the oil-cooled rotor provided in this application; Figure 4 This is a schematic diagram of the structure of the first lamination of the oil-cooled rotor provided in this application; Figure 5 This is a schematic diagram of the structure of the second lamination of the oil-cooled rotor provided in this application; Figure 6 This is a front view structural schematic diagram of the shaft of the oil-cooled rotor provided in this application; Figure 7 A cross-sectional structural schematic diagram of the shaft of the oil-cooled rotor provided in this application; Figure 8 A schematic diagram of the steel sleeve for the oil-cooled rotor provided in this application; Figure 9 A cross-sectional structural schematic diagram of the first implementation of the oil-cooled rotor provided in this application; Figure 10A cross-sectional structural schematic diagram of a second implementation of the oil-cooled rotor provided in this application; Figure 11 A cross-sectional structural schematic diagram of a third implementation of the oil-cooled rotor provided in this application; Figures 12-20 A schematic flowchart illustrating the assembly method of the oil-cooled rotor provided in this application.

[0017] Attached reference numerals: 100, oil-cooled rotor; 1. Rotating shaft; 11. Central main oil passage; 12. Connecting hole; 2. Rotor core; 21. Cooling oil passage; 3. First lamination unit; 31. First lamination; 311. Annular oil passage; 312. First oil guide hole; 4. Second stamping unit; 41. Second stamping; 411. Second oil guide hole; 5. Steel sleeve; Z, First direction. Detailed Implementation

[0018] The advantages of the present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments.

[0019] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0020] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0021] It should be understood that although the terms first, second, third, etc., may be used in this disclosure to describe various information, such information should not be limited to these terms. These terms are used only to distinguish information of the same type from one another. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0022] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and 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. Therefore, they should not be construed as limitations on this invention.

[0023] In the description of this invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical or electrical connections, or internal connections between two components. They can be direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0024] In the following description, suffixes such as "module," "part," or "unit" used to denote elements are used only for the convenience of the description of the invention and have no specific meaning in themselves. Therefore, "module" and "part" can be used interchangeably.

[0025] First, we will explain the specific implementation methods of oil-cooled rotors in existing technologies. With the rapid development of new energy drive systems, permanent magnet synchronous motors play a crucial role in many fields due to their high power density and high efficiency. However, during continuous high-load operation, the internal structural components of the rotor generate a large amount of heat. If effective heat exchange cannot be achieved in a timely manner, it can easily lead to demagnetization of the magnets, thereby seriously affecting the motor's output performance and service life. Therefore, introducing an efficient cooling mechanism has become a core aspect of motor design. Currently, constructing cooling oil circuits inside the rotor for oil cooling heat dissipation, which can directly introduce the cooling medium to the heat source center, has been widely used in the thermal management system of motors and is a key technical means to ensure stable motor operation and overcome power density bottlenecks.

[0026] Existing rotor oil cooling solutions generally employ a combination of perforated rotor shaft oil inlet and core oil circuits for cooling. However, this existing technology has revealed several limitations in practical applications and manufacturing. First, to achieve the distribution and guidance of the cooling medium flow, existing technologies often require the addition of complex structures such as balance discs or end plates to construct the oil circuit distribution chamber. This not only makes the rotor assembly cumbersome but also increases the overall manufacturing cost and the variety of materials. Second, during the assembly of the rotor shaft and rotor core, the existing structure has extremely stringent requirements for the circumferential phase alignment between the oil outlet hole on the rotor shaft and the internal oil guide hole in the core, greatly increasing the assembly difficulty and making it difficult to meet the needs of large-scale, high-efficiency industrialization. Furthermore, the oil circuit structure formed by the stacked laminations in existing technologies is prone to having fluid dead zones that are not connected to the main flow channels. When the rotor rotates at high speed, the cooling oil stagnating in the dead zones can easily cause cooling compensation and dynamic imbalance problems in the rotor.

[0027] To address this problem, this application provides an oil-cooled rotor and its assembly method.

[0028] Please see Figures 1-8 , Figure 1 A schematic diagram of the external structure of the oil-cooled rotor provided in this application; Figure 2 A schematic diagram of the external structure of the first lamination unit of the oil-cooled rotor provided in this application; Figure 3 A cross-sectional view of the first lamination unit of the oil-cooled rotor provided in this application; Figure 4 This is a schematic diagram of the structure of the first lamination of the oil-cooled rotor provided in this application; Figure 5 This is a schematic diagram of the structure of the second lamination of the oil-cooled rotor provided in this application; Figure 6 This is a front view structural schematic diagram of the shaft of the oil-cooled rotor provided in this application; Figure 7 A cross-sectional structural schematic diagram of the shaft of the oil-cooled rotor provided in this application; Figure 8 This is a schematic diagram of the steel sleeve of the oil-cooled rotor provided in this application.

[0029] like Figures 1-8 As shown, the present invention discloses an oil-cooled rotor 100, comprising: a rotating shaft 1, wherein the rotating shaft 1 has a central main oil passage 11 extending along a first direction Z inside, and the outer peripheral sidewall of the rotating shaft 1 has a plurality of connecting holes 12 communicating with the central main oil passage 11; the first direction Z is the axial extension direction of the rotating shaft 1. The rotor core 2 is sleeved on the outer periphery of the rotating shaft 1. The rotor core 2 is composed of at least one first lamination unit 3. The first lamination unit 3 includes one first lamination 31 and an even number of second laminations 41. The first lamination 31 is located at the center of the first lamination unit 3. The even number of second laminations 41 are symmetrically arranged on both sides of the first lamination 31 along the first direction Z and are fixed relative to the first lamination 31. The first lamination 31 is provided with a first oil guide hole 312, and the second laminations 41 are provided with a second oil guide hole 4. 11; The inner diameter of the first lamination 31 is larger than the outer diameter of the shaft 1, and the first lamination 31 is coaxially arranged with the shaft 1, so that an annular oil passage 311 is formed between the inner wall of the first lamination 31 and the outer side of the shaft 1. The annular oil passage 311 is arranged opposite to and connected to the connecting hole 12; wherein, the cooling oil flows through the central main oil passage 11, the connecting hole 12, and the annular oil passage 311 in sequence, and flows evenly to the cooling oil passages 21 on both sides, and finally flows out from both ends of the rotor core 2 in the first direction Z; Two steel sleeves 5 are respectively pressed and set at both ends of the rotor core 2 in the first direction Z, and are sleeved on the rotating shaft 1 to press and fix the rotor core 2 and the rotating shaft 1.

[0030] This can be understood as follows: the oil-cooled rotor 100 provided in this application redefines the oil passage structure and distribution method inside the rotor. The method of forming oil passages through the opening and stacking of laminations achieves oil conduction along the rotor's axial laminations, eliminating the need for the complex balance disc structure found in existing technologies, thus greatly simplifying the rotor assembly. After flowing out from the central main oil passage 11 of the shaft 1 via the connecting hole 12, the cooling oil first enters the annular oil passage 311 naturally formed by the large inner diameter of the first lamination 31 for spatial buffering and uniform distribution, and then enters the cooling oil passage 21 jointly formed by the first guide hole 312 and the second guide hole 411. Importantly, the existence of the annular oil passage 311 physically decouples the assembly phase restriction between the connecting hole 12 of the shaft 1 and the internal oil passages of the rotor core 2, eliminating the need for stringent circumferential alignment of the shaft 1 during press-fitting. Meanwhile, the design of an even number of second laminations 41 symmetrically distributed on both sides of the first lamination 31 within the first lamination unit 3 ensures the uniformity of oil flow to both axial ends from the source. Furthermore, this solution only requires two different laminations, the first lamination 31 and the second lamination 41, to form corresponding lamination units through phase and combination, thereby realizing the aforementioned complex cooling oil circuit. The limited number of lamination types greatly facilitates industrial manufacturing.

[0031] The above is an explanation of the basic concept of this application. The specific implementation of each component will be explained below with reference to the accompanying drawings.

[0032] First, the method of fixing the first stamping 31 and the second stamping 41 is not limited.

[0033] In one possible implementation, in the first lamination unit 3, the first lamination 31 and the adjacent second lamination 41 are fixedly connected by adhesive bonding. Alternatively, the surface of the first punch 31 may be provided with protrusions or grooves, and the surface of the second punch 41 may be provided with grooves or protrusions corresponding to the surface structure of the first punch 31, so that the first punch 31 and the second punch 41 can be snapped together and fixed.

[0034] Because the inner diameter of the first lamination 31 is larger than the outer diameter of the shaft 1, it cannot be effectively supported radially or axially by the shaft 1 and is in a relatively suspended state. By introducing an adhesive bonding process between the first lamination 31 and the adjacent second lamination 41, or by using the surface protrusions and slotted structural features for snap-fit ​​fixing, combined with the inherent magnets on the lamination surface to assist in positioning and withstand some shear force, the first lamination 31 can be stably attached to the second lamination 41. This approach of integrating the partially suspended structure into a rigid unit ensures that the internal stacked structure of the first lamination unit 3 will not experience axial slippage or radial displacement when rotating at high speed with the shaft 1, fundamentally avoiding oil circuit blockage or rotor dynamic imbalance caused by lamination misalignment.

[0035] Secondly, the specific composition of the rotor core 2 is also not limited.

[0036] Please see Figure 9 , Figure 9 A cross-sectional structural schematic diagram of the first implementation of the oil-cooled rotor provided in this application.

[0037] like Figure 9 As shown, in one possible implementation, the rotor core 2 includes five, six, seven or eight first lamination units 3, each of which is staggered and fixed relative to each other along the first direction Z, so that the coolant flows out along the annular oil passage 311 corresponding to any first lamination 31, and then flows through the cooling oil passage 21 to both ends of the rotor core 2 in the first direction Z.

[0038] This can be understood as follows: Based on the aforementioned structure, this application provides a full-section oil inlet solution. The first lamination unit 3 covers the entire axial segment of the rotor core 2. Since each first lamination unit 3 contains a first lamination 31 and a corresponding annular oil passage 311, this means that every segment of the rotor core 2 along the axial direction can directly receive fresh cooling oil from the shaft 1. This multi-point parallel oil inlet fluid network design breaks the axial temperature gradient caused by traditional single-end oil inlet or center single-point oil inlet. The coolant can quickly remove the heat generated by each segment of the core along the shortest path, achieving ultimate heat exchange efficiency along the entire axial length of the rotor, which is especially suitable for high power density applications with extremely stringent temperature control requirements.

[0039] The above is an exemplary description of one possible composition of the rotor core 2 provided in this application. Several other composition schemes will be described below with reference to the accompanying drawings.

[0040] Please see Figures 10-11 , Figure 10 A cross-sectional structural schematic diagram of a second implementation of the oil-cooled rotor provided in this application; Figure 11 A cross-sectional structural schematic diagram of a third implementation of the oil-cooled rotor provided in this application.

[0041] like Figures 10-11 As shown, in one possible implementation, the oil-cooled rotor 100 further includes a second lamination unit 4, which is formed by stacking and fixing a plurality of second laminations 41 along a first direction Z.

[0042] By introducing the second lamination unit 4, a key indirect oil inlet component is provided for the modular configuration of the rotor core 2. The second lamination unit 4 is entirely composed of stacked second laminations 41 with a conventional inner diameter. Its interior only contains axial flow channels formed by second oil guide holes 411, and lacks a radial cross-section for directly obtaining cooling oil from the shaft 1. Introducing this purely axially-oriented second lamination unit 4 as a standard module allows designers to flexibly adjust the flow resistance distribution and coolant flow throughout the rotor by combining it with the first lamination unit 3, which has radial oil inlet capability. This not only enriches the topology of the oil circuit design but also strictly limits the required lamination types to no more than two, significantly improving the convenience of industrial manufacturing. Furthermore, compared to the first lamination 31, which does not match the diameter of the shaft 1, the second lamination 41 has higher structural strength and a more stable connection to the shaft 1, making it suitable for scenarios with high strength and speed design standards but not requiring extreme heat dissipation.

[0043] It is understandable that, based on the first lamination unit 3 and the second lamination unit 4 mentioned above, those skilled in the art can design the rotor core 2 as needed to match different design standards.

[0044] For example, in one possible implementation, the rotor core 2 includes an odd number of first lamination units 3 and second lamination units 4; wherein the rotor core 2 includes one first lamination unit 3 and an even number of second lamination units 4. The first lamination unit 3 is located at the center of the rotor core 2, and an even number of second lamination units 4 are symmetrically arranged on both sides of the first lamination unit 3.

[0045] This can be understood as follows: when the rotor core 2 includes an odd number of lamination units, this application constructs an absolutely symmetrical fluid dispersion model. By precisely positioning the unique first lamination unit 3 at the physical geometric center of the rotor core 2, and arranging the even number of second lamination units 4 equally and symmetrically on both sides, it is ensured that the cooling oil enters only from a single point in the center of the core. Subsequently, under the action of the internal pressure difference, the oil diffuses synchronously to both ends of the axial direction with a completely consistent path length and fluid resistance. This rigorous symmetrical structure ensures that the left and right halves of the rotor can obtain completely consistent cooling rates during operation, thereby ensuring a high degree of consistency in the thermal expansion of the materials, effectively suppressing thermal deformation caused by temperature differences, and maintaining the dynamic balance of the rotor under high-speed conditions.

[0046] Similarly, in one possible implementation, the rotor core 2 includes an even number of first lamination units 3 and second lamination units 4; wherein, the rotor core 2 includes two first lamination units 3 and an even number of second lamination units 4. Two first lamination units 3 are located at the center of the rotor core 2, and an even number of second lamination units 4 are symmetrically arranged on both sides of the two first lamination units 3.

[0047] For the case of an even number of lamination units, the solution arranges two first lamination units 3 side by side at the center of the rotor core 2, jointly serving as the central oil inlet hub. These two oil inlet nodes are closely adjacent, forming a relatively wide central oil inlet area. Subsequently, the cooling oil is evenly distributed into the even number of second lamination units 4 symmetrically arranged on both sides. This design, under the constraint of an even number of segments, maximizes the symmetrical flow distribution effect of a single-point central oil inlet, ensuring balanced oil output at both ends and a uniform temperature field, while perfectly accommodating the structural requirements of permanent magnet synchronous motors with different pole numbers and lamination thicknesses.

[0048] Furthermore, the relative positional relationship between each stamping unit is also unrestricted.

[0049] In one possible implementation, any two adjacent first lamination units 3, or when the rotor core 2 also includes a second lamination unit 4, any two adjacent first lamination units 3 and second lamination units 4 or any two adjacent second lamination units 4 are staggered to achieve a V-shaped segmented skew pole structure. Using the angular position of the first lamination unit 3 or the second lamination unit 4 on one side of the rotor core 2 in the first direction Z as the reference zero point, the rotor core 2 is rotated sequentially from the angular positions of the first lamination unit 3 and / or the second lamination unit 4 on the other side, with the rotation angle... Configured as: Where j is the position number of the first lamination unit or the second lamination unit in the first direction, j=1,2,...n, and n is the total number of first lamination units and second lamination units contained in the rotor core. For example, n is 5, 6, 7, 8, or 9, and there is no limitation here.

[0050] The lamination units inside the sub-core 2 are not stacked flush, but are strictly staggered according to the rotation angle formula, thus constructing a segmented skewed pole structure with a V-shaped distribution in the axial direction. This V-shaped skewed pole structure can effectively reduce cogging torque, reduce electromagnetic harmonics, and improve the smoothness of motor operation. More ingeniously, although there is a preset skewed pole angle offset between adjacent lamination units, thanks to the reasonable design of the size and distribution of the oil guide holes, the first oil guide hole 312 and / or the second oil guide hole 411 after the skewed poles are staggered can still maintain an effective overlap area in the axial direction, ensuring the full continuity of the stepped cooling oil circuit in the V-shaped tortuous extension state, ensuring efficient cooling while taking into account the excellent electromagnetic performance of the motor.

[0051] Finally, the specific relative positions of the stampings within each stamping unit are also not limited.

[0052] In one possible implementation, when the rotor core 2 also includes a second lamination unit 4, the angular position offset between the first lamination unit 31 and the second lamination unit 41, or between any two adjacent second laminations 41, is 45°, with the angular position of the second lamination 41 located on one side of the first direction Z as the reference zero point.

[0053] Inside the first lamination unit 3 and the second lamination unit 4, a 45-degree angular offset is set between adjacent laminations. This significant staggered stacking transforms the originally straight channels into a complex, stepped labyrinthine oil passage. As the cooling oil flows through these staggered interfaces, the flow is continuously cut and disturbed, transforming from laminar to turbulent flow, drastically increasing the contact area and heat transfer coefficient between the oil and the lamination metal. Simultaneously, this specific staggered arrangement effectively reduces fluid dead zones in the lamination gaps that are not connected to the main flow channels, avoiding the potential risk of rotor dynamic imbalance caused by long-term stagnation and accumulation of lubricating oil in these dead zones.

[0054] The above is a complete description of the oil-cooled rotor 100 provided in this application. The assembly method of the oil-cooled rotor 100 will be described below.

[0055] Please see Figures 12-20 , Figures 12-20 A schematic flowchart illustrating the assembly method of the oil-cooled rotor provided in this application.

[0056] like Figures 12-20 As shown, and in combination Figures 1-11It is understood that the second aspect of this application provides a method for assembling the oil-cooled rotor 100 of any of the foregoing, comprising: The first lamination 31 and the second lamination 41 are stacked and fixed along the first direction Z to form the first lamination unit 3; when the rotor core 2 includes the second lamination unit 4, multiple second laminations 41 are stacked and fixed along the first direction Z to form the second lamination unit 4. The first lamination unit 3, or the first lamination unit 3 and the second lamination unit 4 are stacked alternately in a preset order along the first direction Z to form the rotor core 2, so that a preset oblique pole angle is formed between each lamination unit. Insert the rotating shaft 1 into the rotor core 2 along the first direction Z, and position the rotating shaft 1 axially so that the connecting hole 12 of the rotating shaft 1 is radially connected to the annular oil passage 311. Steel sleeves 5 are press-fitted on both sides of the rotor core 2 in the first direction Z to press and fix the rotor core 2 to the outer periphery of the rotating shaft 1.

[0057] Based on the above structure, this application also provides a modular assembly method. By pre-assembling and fixing the laminations into independent lamination units externally, and then stacking them alternately at a preset oblique angle, the complex phase control is decentralized to the unit level. When assembling the shaft 1 and the rotor core 2, since the first lamination unit 3 has a pre-fabricated annular oil passage 311, the operator only needs to complete the axial advancement and positioning of the shaft 1 to naturally achieve radial communication between the shaft 1 connecting hole 12 and the annular oil passage 311. This blind-insertion assembly logic that eliminates circumferential phase alignment completely removes the process bottleneck of rotor shaft hole alignment in the prior art. Combined with the rapid pressing of the steel sleeves 5 at both ends, it significantly reduces the assembly difficulty and manufacturing cost of the production line.

[0058] It should be noted that the embodiments of the present invention have better implementability and are not intended to limit the present invention in any way. Any person skilled in the art may use the above-disclosed technical content to change or modify it into equivalent effective embodiments. However, any modifications or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. An oil-cooled rotor, characterized in that, include: A rotating shaft has a central main oil passage extending along a first direction inside, and several connecting holes communicating with the central main oil passage are opened on the outer peripheral sidewall of the rotating shaft; the first direction is the axial extension direction of the rotating shaft; A rotor core is sleeved on the outer periphery of the rotating shaft. The rotor core is composed of at least one first lamination unit, which includes one first lamination and an even number of second laminations. The first lamination is located at the center of the first lamination unit, and the even number of second laminations are symmetrically arranged on both sides of the first lamination along the first direction and fixed relative to the first lamination. The first lamination has a first oil guide hole, and the second lamination has a second oil guide hole. The inner diameter of the first lamination is larger than the outer diameter of the rotating shaft, and the first lamination is coaxial with the rotating shaft, so that an annular oil channel is formed between the inner peripheral wall of the first lamination and the outer peripheral side of the rotating shaft. The annular oil channel is arranged opposite to and communicates with the connecting hole. The first oil guide hole and the second oil guide hole together form multiple cooling oil channels in the first direction, so that the cooling oil flows sequentially through the central main oil channel, the connecting hole, and the annular oil channel, and flows evenly to the cooling oil channels on both sides, and finally flows out from both ends of the rotor core in the first direction. Two steel sleeves are respectively pressed and fitted onto the two ends of the rotor core in the first direction, and are sleeved on the rotating shaft to press and fix the rotor core to the rotating shaft.

2. The oil-cooled rotor as described in claim 1, characterized in that, In the first lamination unit, the first lamination and the adjacent second lamination are fixedly connected by adhesive bonding. Alternatively, the surface of the first stamping piece is provided with a protrusion or a groove, and the surface of the second stamping piece is provided with a groove or a protrusion corresponding to the surface structure of the first stamping piece, so that the first stamping piece and the second stamping piece are snapped together and fixed.

3. The oil-cooled rotor as described in claim 1, characterized in that, The rotor core includes five, six, seven or eight first lamination units, each of which is arranged in an alternating layer along the first direction and fixed relative to each other, so that coolant flows out along the annular oil channel corresponding to any first lamination, and then flows through the cooling oil channel to both ends of the rotor core in the first direction.

4. The oil-cooled rotor as described in claim 1, characterized in that, The oil-cooled rotor also includes a second lamination unit, which is formed by stacking and fixing multiple second laminations along the first direction.

5. The oil-cooled rotor as described in claim 4, characterized in that, The rotor core includes an odd number of first lamination units and second lamination units; wherein, the rotor core includes one first lamination unit and an even number of second lamination units; The first lamination unit is located at the center of the rotor core, and an even number of second lamination units are symmetrically arranged on both sides of the first lamination unit.

6. The oil-cooled rotor as described in claim 4, characterized in that, The rotor core includes an even number of first lamination units and second lamination units; wherein, the rotor core includes two first lamination units and an even number of second lamination units; Two first lamination units are disposed at the center of the rotor core, and an even number of second lamination units are symmetrically disposed on both sides of the two first lamination units.

7. The oil-cooled rotor as described in any one of claims 3 to 6, characterized in that, Any two adjacent first lamination units, or when the rotor core also includes a second lamination unit, any two adjacent first lamination units and the second lamination unit or any two adjacent second lamination units are staggered to achieve a V-shaped segmented skewed pole structure. Using the angular position of the first lamination unit or the second lamination unit on one side of the rotor core in the first direction as a reference zero point, the rotor core is rotated sequentially from that side to the angular positions of the first lamination unit and / or the second lamination unit on the other side, with the rotation angle... Configured as: Where j is the position number of the first lamination unit or the second lamination unit in the first direction, j=1,2,...n, and n is the total number of the first lamination units and the second lamination units contained in the rotor core.

8. The oil-cooled rotor as described in claim 4, characterized in that, When the rotor core further includes the second lamination unit, the angular position of the second lamination located on one side in the first direction is taken as the reference zero point within the first lamination unit and the second lamination unit. The angular position offset between the first lamination and the second lamination, or between any two adjacent second laminations, is 45°.

9. A method for assembling an oil-cooled rotor as described in any one of claims 1 to 8, characterized in that, include: The first lamination and the second lamination are stacked and fixed along the first direction to form the first lamination unit; When the rotor core includes the second lamination unit, multiple second laminations are stacked and fixed along the first direction to form the second lamination unit; The first lamination unit, or the first lamination unit and the second lamination unit, are stacked alternately along the first direction in a preset order to form the rotor core, so that a preset oblique pole angle is formed between each lamination unit. Insert the rotating shaft into the rotor core along the first direction and position the rotating shaft axially so that the connecting hole of the rotating shaft is radially connected to the annular oil passage. The steel sleeves are pressed onto both sides of the rotor core in the first direction to press and fix the rotor core to the outer periphery of the shaft.

Images