Rotor module with cooling structure

Abstract

The utility model relates to a rotor module with cooling structure. The present disclosure relates to a rotor module applicable to a vehicle, and more particularly to a rotor module with cooling structure. The rotor module with cooling structure of the present disclosure can be formed such that a flow path can be formed on the outer surface of the rotor shaft, thereby establishing an oil supply path from the hollow shaft to the rotor core, solving the heating problem and demagnetization problem by directly cooling the rotor core, and being capable of simultaneously supplying oil and lubricating the clutch of the speed reducer and the needle roller bearing (NRB) of the planetary gear, Ravigneaux gear and the like.

Description

Technical Field

[0001] This disclosure relates to a rotor module for use in vehicles, and more particularly to a rotor module with a heat dissipation structure. Background Technology

[0002] Recently, as the heat generated by permanent magnets increases with motor speed, it is essential to have rotor cooling capabilities to prevent a decrease in motor efficiency. Traditional hollow shafts utilize centrifugal force to cool the motor and lubricate the reducer through a hollow structure and machined flow path holes. In other words, cooling is achieved by supplying oil from the center of rotation and diffusing the centrifugally stressed oil towards the outer diameter of the core through the holes.

[0003] However, unlike off-axis rotors, traditional on-axis rotors have the following problems: Since the drive shaft is located inside the rotor shaft, the utilization of internal space is limited, and the rotational efficiency of the drive shaft is reduced when the interior of the hollow shaft is used as a flow path. More specifically, off-axis hollow shafts lack rotor cooling, and while hollow shafts have been used to address NVH issues and reduce weight, the heat generated in the rotor is no longer a significant problem with advancements in motor performance. Coaxial hollow shafts initially also lacked rotor cooling and employed a structure where the drive shaft passed through the hollow shaft. However, with improvements in permanent magnet performance, issues of rotor heat generation and losses arose, highlighting the need for cooling. To address this need, coaxial hollow shafts introduced a method of injecting oil into the hollow shaft to cool the rotor. However, because the drive shaft rotating inside the hollow shaft and the cooling oil share space, shaft rotation may be impeded, leading to reduced drive efficiency.

[0004] Related technical documents

[0005] (Patent Document 1) Korean Patent Application No. 10-2024-0081340 (MOTOR COOLING STRUCTURE). Utility Model Content

[0006] This disclosure aims to solve the above-mentioned problems and provides a rotor module with a cooling structure in which a flow path can be formed on the outer surface of the rotor shaft to establish an oil supply path from the hollow shaft to the rotor core. This solves the heat generation and demagnetization problems by directly cooling the rotor core and enables simultaneous oil supply and lubrication of the clutch of the reducer and the needle roller bearings (NRB) of planetary gears, Ravinios gears, etc.

[0007] According to one embodiment of this disclosure, a rotor module with a cooling structure is provided, the rotor module comprising: a rotor core formed in a hollow cylindrical shape; a rotor shaft fixedly inserted into the center of the rotor core and rotating about the central axis of the rotor core; and a cooling flow path unit formed in the rotor core and the rotor shaft, through which cooling oil flows, wherein the cooling flow path unit includes at least one first flow path, the at least one first flow path being recessed in the outer surface of the rotor shaft in a groove shape and extending along the axial direction of the rotor shaft.

[0008] Additionally, the cooling flow path unit may further include: a second flow path, which is a hole formed radially in the rotor core and one end of the second flow path is connected to the first flow path; and a third flow path, which is a hole arranged axially in the rotor core and includes an outlet, one end of the third flow path is connected to the second flow path and the other end of the third flow path is connected to the outside of the rotor core.

[0009] In addition, the other end of the third flow path may be formed at a position closer to the center of the rotor core than the first end of the third flow path.

[0010] Additionally, the rotor core may have magnets embedded in the rotor core, the magnets may be configured to have two or more layers spaced apart from each other in the radial direction of the rotor core, and the third flow path may be formed between the layers of the magnets.

[0011] Additionally, the cooling flow path unit may also include a tubular leak-proof plate stacked between the rotor core and the rotor shaft, and having an inner surface that contacts the outer surface of the rotor shaft.

[0012] Additionally, the tubular leak-proof plate may have a connecting hole formed at a location where the first flow path and the second flow path communicate with each other.

[0013] In addition, the tubular leak-proof plate can be thermo-pressed into the outer surface of the rotor shaft.

[0014] Additionally, the cooling flow path unit may also include an oil guide, one end of which is connected to one end of the rotor core, the other end of which extends toward the rotor shaft to cover a portion of the outer surface of the rotor shaft, and the oil guide is configured to be spaced apart from the rotor shaft by a predetermined distance.

[0015] Additionally, the oil guide may include a fastening portion, one end of which is connected to the rotor core, and the fastening portion may include: a connecting portion having a connecting hole and a surface that contacts the rotor core, the connecting hole being formed to pass through the connecting portion in the axial direction of the rotor shaft; and a fastener passing through both the connecting hole and the rotor core to secure the fastening portion to the rotor core.

[0016] Additionally, the oil guide may also include an anti-splash portion, which is formed to extend to cover the rotor shaft at the other end, and the anti-splash portion may include: a first extension portion formed to extend from the fastening portion and to extend along the axial direction of the rotor shaft; and a second extension portion formed to extend from the first extension portion and to extend along the radial direction of the rotor shaft.

[0017] Additionally, two or more first flow paths may be formed on the surface of the rotor shaft, and each first flow path may have one end located at one end of the rotor shaft and may have different axial lengths. Attached Figure Description

[0018] Figure 1 This is a perspective view showing a cross-section of the rotor module with a cooling structure disclosed herein.

[0019] Figure 2 This is a partial perspective view showing a rotor shaft in which a first flow path is formed, according to the present disclosure.

[0020] Figure 3 This is a partial perspective view showing the cross-section of the rotor module with cooling structure disclosed herein.

[0021] Figure 4 and Figure 5 This is a partial perspective view showing the rotor shaft, to which a rotor module with a cooling structure according to the first embodiment of this disclosure is applied according to the rotor shaft.

[0022] Figure 6 This is a partial perspective view showing a rotor module with a cooling structure according to a second embodiment of the present disclosure.

[0023] Figure 7 This is a partial cross-sectional view showing a rotor module with a cooling structure according to a second embodiment of the present disclosure.

[0024] Figure 8 This is a partial perspective view showing a rotor module with a cooling structure according to a third embodiment of the present disclosure.

[0025] Figure 9 This is a partial perspective view showing an example of applying a leak-proof plate to a rotor module with a cooling structure according to a third embodiment of the present disclosure. Detailed Implementation

[0026] The technical spirit of this disclosure will be described in more detail below with reference to the accompanying drawings. Prior to this, the terms or words used in this specification and claims should not be construed as limited to their ordinary or dictionary meanings, but should be interpreted as meanings and concepts consistent with the technical concept of this disclosure, based on the principle that the inventor of the utility model can appropriately define the concepts of the terms in order to best describe his or her own disclosure.

[0027] In the following text, reference will be made to Figures 1 to 3 The basic structure of the rotor module 1000 with cooling structure disclosed herein is described.

[0028] like Figure 1 As shown, the rotor module 1000 with a cooling structure disclosed herein may include a rotor core 100 and a rotor shaft 200. The rotor core 100 may be formed in a hollow cylindrical shape, and the rotor shaft 200 may be fixedly inserted into the center of the rotor core 100 and may rotate about the central axis of the rotor core 100. Furthermore, the rotor module 1000 with a cooling structure disclosed herein may include a cooling flow path unit 300, which is formed in the rotor core 100 and the rotor shaft 200, through which cooling oil flows. In this case, the cooling flow path unit 300 may guide the cooling oil along... Figure 1 The arrows in the text indicate the direction of flow.

[0029] In this case, such as Figure 2 As shown, the cooling flow path unit 300 may include at least one first flow path 310, which is recessed in the outer surface of the rotor shaft 200 in a groove shape and formed along the axial direction of the rotor shaft 200. Two or more first flow paths 310 may be formed, and the formation position of the first flow paths 310 can be easily changed according to the arrangement of the rotor core 100, the rotor shaft 200, and adjacent components. The rotor module 1000 with cooling structure of this disclosure includes the first flow path 310, thereby establishing an oil supply path to the rotor core 100 when applied to the hollow rotor shaft 200, solving the heat generation and demagnetization problems by directly cooling the rotor core 100, and enabling simultaneous oil supply and lubrication for the clutch of the reducer and the needle roller bearings (NRB) of planetary gears, Ravenna gears, etc.

[0030] In addition, such as Figure 3As shown, the cooling flow path unit 300 may include a second flow path 320 and a third flow path 330, which communicate with the first flow path 310 and allow cooling oil to flow into the rotor core 100. More specifically, the second flow path 320 is a hole formed radially in the rotor core 100, and one end of it may communicate with the first flow path 310. Therefore, due to the centrifugal force when the rotor shaft 200 rotates, the cooling oil that has cooled the rotor shaft 200 while flowing along the first flow path 310 can move radially outward along the second flow path 320, that is, flow into the interior of the rotor core 100. The third flow path 330 is a hole formed axially in the rotor core 100 and may include an outlet 331. One end of the third flow path 330 communicates with the other end of the second flow path 320, and the other end of the third flow path 330 is provided with an outlet 331 communicating with the outside of the rotor core 100.

[0031] Thus, since the cooling flow path unit 300 further includes a second flow path 320 and a third flow path 330, the cooling oil introduced through the first flow path 310 can flow into the rotor core 100 to simultaneously cool the rotor shaft 200 and the rotor core 100. Furthermore, by positioning the outlet 331 of the third flow path 330 at the end of the rotor core 100, cooling oil can also be sprayed onto components of the reducer such as clutches, gears, and bearings located at the end of the rotor core 100, thereby achieving both cooling and lubrication effects simultaneously.

[0032] Furthermore, the outlet 331 at the other end of the third flow path 330 can be formed at a location closer to the center of the rotor core 100 than at one end of the third flow path 330. That is, a step can be formed upstream of the outlet 331 in the direction of cooling oil flow. Therefore, the cooling oil discharged from the outlet 331 at the other end of the third flow path 330 can flow toward the central axis of the rotor core 100 and the rotor shaft 200, thereby allowing the cooling oil to be sprayed onto the gears and bearings.

[0033] Furthermore, the rotor core 100 may have magnets 110 embedded within it, and have two or more layers spaced apart from each other in the radial direction of the rotor core 100. In this case, a third flow path 330 may be formed between the layers of each magnet 110. Therefore, the magnets 110, which are the main heat-generating components, can be cooled more effectively.

[0034] In the following text, reference will be made to Figure 4 and Figure 5 A rotor module 1000 with a cooling structure according to a first embodiment of the present disclosure will be described in more detail.

[0035] In the rotor module 1000 with a cooling structure according to the first embodiment of this disclosure, such as Figure 4 As shown, the cooling flow path unit 300 may further include a leak-proof plate 340, which is stacked between the rotor core 100 and the rotor shaft 200, has an inner surface that contacts the outer surface of the rotor shaft 200, and has a tubular shape. The leak-proof plate 340 can be formed by processing a steel plate. By including the leak-proof plate 340, a space can be formed for cooling oil to flow through the leak-proof plate 340 and the first flow path 310, and even when the inner surface of the rotor core 100 is uneven and therefore the leak-proof plate 340 may not form a space for cooling oil to flow between the leak-proof plate itself and the first flow path 310, the leak-proof plate 340 can still form a space for cooling oil to move axially between the leak-proof plate 340 itself and the first flow path 310.

[0036] In this case, the leak-proof plate 340 is preferably heat-pressed into the outer surface of the rotor shaft 200. Therefore, the leak-proof plate 340 and the rotor shaft 200 can be more tightly connected, and cooling oil can be prevented from leaking out from the first flow path 310 between the rotor shaft 200 and the leak-proof plate 340.

[0037] In addition, such as Figure 5 As shown, the leak-proof plate 340 may have a through hole 341 perforated at a location where the first flow path 310 and the second flow path 320 communicate with each other. Therefore, even when the leak-proof plate 340 is press-fitted, the first flow path 310 and the second flow path 320 are still in communication with each other to allow cooling oil to be delivered to the rotor core 100.

[0038] In the following text, reference will be made to Figure 6 and Figure 7 A rotor module 1000 with a cooling structure according to a second embodiment of the present disclosure will be described in more detail.

[0039] In the rotor module 1000 with a cooling structure according to the second embodiment of this disclosure, such as Figure 6 As shown, the cooling flow path unit 300 may further include an oil guide 350, one end of which is connected to one end of the rotor core 100, and the other end extends toward the rotor shaft 200 to cover a portion of the outer surface of the rotor shaft 200. The oil guide 350 is positioned at a predetermined distance from the rotor shaft 200. More specifically, the oil guide 350 may be connected to the end of the rotor core 100 or rotor shaft 200 formed at a location for accommodating bearings, reservoirs, holders, etc. Cooling oil can be sprayed onto the end of the rotor shaft 200 or rotor core 100 to which the oil guide 350 is applied through either a conventional O-tube or a direct nozzle of a reducer. In this case, the oil guide 350 can be used to guide the flow of cooling oil to prevent splashing or to capture the sprayed cooling oil.

[0040] More specifically, such as Figure 7 As shown, the oil guide 350 may include a fastening portion 351, one end of which is connected to the rotor core 100. The fastening portion 351 may include a connecting portion 351a and a fastener 351c for the rotor shaft 200. More specifically, the connecting portion 351a may have a connecting hole 351b formed axially through the connecting portion 351a and a surface that contacts the rotor core 100. In this case, the connecting portion 351a may contact a surface of one of a plurality of ends formed on the rotor core 100, and the rotor core 100 may have a hole of the same size formed at a position corresponding to the location where the connecting hole 351b is formed. Additionally, the fastener 351c may pass through both the connecting hole 351b and the rotor core 100 to secure the fastening portion 351 to the rotor core 100.

[0041] Furthermore, the oil guide 350 may also include an anti-splash portion 352, the other end of which is formed to extend to cover the rotor shaft 200. The anti-splash portion 352 may include a first extension 352a and a second extension 352b integrally formed with each other. More specifically, the first extension 352a may be formed to extend from the fastening portion 351 and to extend in the axial direction of the rotor shaft 200, and the second extension 352b may be formed to extend from the first extension 352a and to extend in the radial direction of the rotor shaft 200. In this way, by including the vertically bent anti-splash portion 352, the splashing of cooling oil due to the centrifugal force of the shaft during the oil injection process can be prevented, thereby facilitating the injection of cooling oil.

[0042] In the following text, reference will be made to Figure 8 and Figure 9 The third embodiment of this disclosure will be described in more detail.

[0043] like Figure 8 As shown, two or more first flow paths 310 may be formed on the surface of the rotor shaft 200, and each may have a different axial length. In this case, one end of each first flow path 310 may be located at one end of the rotor shaft 200. Therefore, the injection direction of the cooling fluid flowing along the first flow path 310 may be different to allow the cooling fluid to be injected to more different locations.

[0044] In this case, such as Figure 9 As shown, a leak-proof plate 340 can be connected to the third embodiment and the first embodiment. In this case, the connecting hole 341 of the leak-proof plate 340 can be formed at the other end of each first flow path 310 to allow cooling fluid to be discharged from the end of each first flow path 310.

[0045] With this configuration, a rotor module with a cooling structure can be formed, which allows a flow path to be created on the outer surface of the rotor shaft, thereby establishing an oil supply path from the hollow shaft to the rotor core. This solves the heat generation and demagnetization problems by directly cooling the rotor core, and also enables simultaneous oil supply and lubrication of the reducer's clutches and the needle roller bearings (NRBs) of planetary gears, Ravenna gears, etc.

[0046] The technical spirit of this disclosure should not be construed as limited to the embodiments described above. Not only is the scope of application diverse, but those skilled in the art can make various modifications without departing from the essential points of this disclosure as claimed in the claims. Therefore, such improvements and variations fall within the scope of this disclosure, provided they are obvious to those skilled in the art.

Claims

1. A rotor module with a cooling structure, the rotor module comprising: The rotor core is configured as a hollow cylindrical shape; A rotor shaft, which is fixedly inserted into the center of the rotor core and rotates about the central axis of the rotor core; and A cooling flow path unit is disposed in the rotor core and the rotor shaft, through which cooling oil flows. The feature is that the cooling flow path unit includes at least one first flow path, which is recessed in the outer surface of the rotor shaft in a groove shape and extends along the axial direction of the rotor shaft.

2. The rotor module with a cooling structure according to claim 1, characterized in that, The cooling flow path unit further includes: A second flow path, which is radially disposed in the rotor core in the form of a hole, wherein one end of the second flow path communicates with the first flow path; and A third flow path is axially disposed in the rotor core in the form of a hole and includes an outlet. One end of the third flow path communicates with the second flow path, and the other end of the third flow path communicates with the outside of the rotor core.

3. The rotor module with a cooling structure according to claim 2, characterized in that, The other end of the third flow path is located closer to the center of the rotor core than the first end of the third flow path.

4. The rotor module with a cooling structure according to claim 2, characterized in that, The rotor core includes magnets embedded in the rotor core. The magnet is configured to have two or more layers spaced apart from each other in the radial direction of the rotor core, and The third flow path is disposed between the layers of the magnet.

5. The rotor module with a cooling structure according to claim 2, characterized in that, The cooling flow path unit also includes a tubular leak-proof plate, which is stacked between the rotor core and the rotor shaft and includes an inner surface that contacts the outer surface of the rotor shaft.

6. The rotor module with a cooling structure according to claim 5, characterized in that, The tubular leak-proof plate includes a connecting hole disposed at a position where the first flow path and the second flow path communicate with each other.

7. The rotor module with a cooling structure according to claim 5, characterized in that, The tubular leak-proof plate is hot-pressed into the outer surface of the rotor shaft.

8. The rotor module with a cooling structure according to claim 1, characterized in that, The cooling flow path unit further includes an oil guide, one end of which is connected to one end of the rotor core, and the other end of which extends toward the rotor shaft to cover a portion of the outer surface of the rotor shaft, and the oil guide is configured to be spaced apart from the rotor shaft by a predetermined distance.

9. The rotor module with a cooling structure according to claim 8, characterized in that, The oil guide includes a fastening part, one end of which is connected to the rotor core, and The fastening part includes: The connecting portion has a connecting hole and a surface that contacts the rotor core, the connecting hole being formed to pass through the connecting portion along the axial direction of the rotor shaft; and Fasteners that pass through both the connecting hole and the rotor core to secure the fastener to the rotor core.

10. The rotor module with a cooling structure according to claim 9, characterized in that, The oil guide also includes an anti-splash portion, which is formed to extend to cover the rotor shaft at the other end, and The anti-scattering component includes: A first extension, the first extension being formed to extend from the fastening portion and to extend along the axial direction of the rotor shaft; and The second extension is formed to extend from the first extension and to extend in the radial direction along the rotor shaft.

11. The rotor module with a cooling structure according to claim 1, characterized in that, Two or more first flow paths are provided on the surface of the rotor shaft, and Each of the first flow paths includes one end located at one end of the rotor shaft and has a different axial length.

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