Rotor module with cooling structure

Abstract

This disclosure relates to a rotor module, and more specifically to a rotor module with a cooling structure. The rotor module with a cooling structure of this disclosure may include: a rotor core formed as a cylinder with a hollow hole through a central portion; a cooling flow path unit in which cooling fluid flows and cools the rotor core; and end plates disposed such that one surface contacts both axial ends of the rotor core, and has oil storage, diffusion, and transport functions at both ends of the rotor core. Therefore, the rotor module with a cooling structure of this disclosure utilizes oil cooling of existing end coils to directly cool the rotor assembly and further cool the stator, thereby effectively solving the problems of heat generation and demagnetization.

Description

Technical Field

[0001] This disclosure relates to a rotor module, and more specifically, to a rotor module having a cooling structure. Background Technology

[0002] The heat source of the drive motor in an electric vehicle is the coil through which current flows and the electrical steel core through which magnetic flux flows. During motor operation, the temperature of the corresponding components rises, and excessively high temperatures can lead to motor failure. To prevent this, cooling the heat source is crucial, and methods exist such as oil cooling, which involves directly spraying oil onto the heat source, and water cooling, which indirectly cools the heat source through water channels that allow coolant to flow through the housing.

[0003] In particular, since cooling the end coils using the stator's cooling flow path is difficult, existing technologies employ methods such as directly injecting cooling fluid through circular tubes. More specifically, in existing technologies, oil is sprayed onto the outer surface of the end coils only through circular tubes at both ends of the rotor assembly to temporarily cool the end coils, and oil diffusers are used to compensate for this. However, conventional oil diffusers have the problem of having two or more axial steps, resulting in insufficient space utilization and increased manufacturing costs.

[0004] In the above structure, it is difficult to cool the end coils using only the stator cooling fluid. Therefore, a two-part cooling oil spray structure is required, so that cooling oil is sprayed onto both the stator core and the end coils. In addition, with the advancement of electric motor specifications, overheating and demagnetization problems have emerged in the rotor assembly, resulting in the need to cool not only the stator core and end coils, but also the rotor assembly.

[0005] Related technical documents

[0006] (Patent Document 1) Korean Patent Registration No. 10-2153232 "MOTOR WITH COOLING SYSTEM" (registered on September 1, 2020) Summary of the Invention

[0007] This disclosure is made to solve the above-mentioned problems and aims to provide a rotor module with a cooling structure that solves the problems of heat generation and demagnetization by installing end plates with oil storage, diffusion and transmission functions at both ends of the rotor core and using oil to cool the existing end coils to directly cool the rotor assembly, and then additionally cooling the stator.

[0008] According to one embodiment of the present disclosure, a rotor module with a cooling structure is provided. The rotor module includes a cylindrical rotor core formed with a hollow hole through a central portion, a cooling flow path unit, and an end plate. The cooling flow path unit is for cooling fluid to flow and cool the rotor core. One surface of the end plate is configured to contact both axial ends of the rotor core. The cooling flow path unit includes at least one first flow channel formed to receive cooling fluid at one end and discharge cooling fluid at the other end, thereby passing through the rotor core axially and cooling the rotor core.

[0009] Additionally, the end plate may include a second flow channel, one end of which is formed at the point where the cooling fluid is injected, and the other end of which is in fluid communication with one end of the first flow channel to deliver the cooling fluid to the first flow channel.

[0010] Additionally, the second flow channel may include a first flow path (2-1), a second flow path (2-2), and a third flow path (2-3). The first flow path (2-1) is a groove formed in the axial direction of the rotor core, and one end of the first flow path (2-1) opens toward the other surface of the end plate to receive cooling fluid. The second flow path (2-2) is a groove formed in the axial direction of the rotor core, and one end of the second flow path (2-2) is in fluid communication with the first flow path (2-1). The third flow path (2-3) is a hole formed in the axial direction of the rotor core, and one end of the third flow path (2-3) is in fluid communication with the second flow path (2-2), while the other end of the third flow path (2-3) is in fluid communication with the first flow channel.

[0011] In addition, the first flow path 2-1 and the second flow path 2-2 can be grooves that are continuously formed in the circumferential direction of the rotor core.

[0012] In addition, the flow cross-sectional area of ​​the third flow path 2-3 can be narrower than the flow cross-sectional area of ​​the first flow channel.

[0013] In addition, the 2-3 third flow paths formed on the end plate that contact one end surface of the rotor core can be formed at a position that does not correspond to the 2-3 third flow paths formed on the end plate that contact the other end surface of the rotor core.

[0014] Additionally, the end plate may include a first fluid scattering flow channel formed at a predetermined angle through the end plate, not perpendicular or parallel to the axial and radial directions of the rotor core, and the first fluid scattering flow channel may have one end in fluid communication with the second flow path 2-2 and the other end open toward another surface of the end plate.

[0015] In addition, the first fluid scattering flow channel can be connected to the second flow path 2-2 at a predetermined distance from the other end of the second flow path 2-2 in the radial direction of the rotor core.

[0016] Additionally, the end plate may include a second fluid scattering flow channel that receives fluid from the first flow channel and scatters the fluid to the outside of the rotor core. The second fluid scattering flow channel is positioned relative to the central axis of the rotor core at a location with a predetermined phase difference from the first fluid scattering flow channel. The second fluid scattering flow channel may include: a 2-1 first fluid scattering flow path, which is a groove recessed into a surface of the end plate, one end of which is in fluid communication with the first flow channel and is formed to extend radially from one end along the radial direction of the rotor core; and a 2-2 second fluid scattering flow path, one end of which is in fluid communication with the 2-1 first fluid scattering flow path and is formed to pass through the end plate at a predetermined angle, without being perpendicular or parallel to the axial and radial directions of the rotor core.

[0017] In addition, the first flow channel can be formed between the hollow hole and the magnet embedded in the rotor core, having an elliptical flow cross section, and the radial direction of the rotor core is the short axis. Attached Figure Description

[0018] Figure 1 This is a partial cross-sectional view showing the rotor module with cooling structure of this disclosure.

[0019] Figure 2 This is a cross-sectional view of the rotor core disclosed herein.

[0020] Figure 3 This is a top view showing another surface of the end plate of this disclosure that is not in contact with the rotor core.

[0021] Figure 4 This is a partial cross-sectional view showing the second flow channel of this disclosure.

[0022] Figure 5 This is a perspective view showing another surface of the end plate of this disclosure that is not in contact with the rotor core.

[0023] Figure 6 This is a perspective view showing one surface of the end plate of the present disclosure that is in contact with the rotor core.

[0024] Figure 7 This is a partial cross-sectional view showing the second fluid scattering flow channel of this disclosure.

[0025] Figure 8 This is a partial cross-sectional view showing the movement of the rotor module with cooling structure of this disclosure.

[0026] Explanation of reference numerals in the attached figures

[0027] 1000: Rotor module with cooling structure

[0028] 100: Rotor core

[0029] 110: Hollow hole

[0030] 200: Cooling flow path unit

[0031] 210: First flow channel

[0032] 220: Second flow channel

[0033] 221:2-1 First Flow Path

[0034] 222: 2-2 Second Flow Path

[0035] 223: 2-3 Third Flow Path

[0036] 230: First fluid scattering flow channel

[0037] 240: Second fluid scattering flow channel

[0038] 241:2-1 First Fluid Scattering Flow Path

[0039] 242:2-2 Second Fluid Scattering Flow Path

[0040] 300: End plate

[0041] S: Rotor shaft

[0042] C: Coil

[0043] O: Cooling fluid

[0044] H: Shell

[0045] M: Magnet Detailed Implementation

[0046] The technical spirit of this disclosure will be described in more detail below with reference to the accompanying drawings. Before the description, 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 spirit of this disclosure, based on the inventor's ability to appropriately define the concepts of the terms in order to best describe the principles of his or her invention.

[0047] In the following text, reference will be made to Figure 1 and Figure 2The basic configuration of the rotor module 1000 with cooling structure disclosed herein is described in more detail.

[0048] like Figure 1 As shown, the rotor module 1000 with a cooling structure disclosed herein may include a rotor core 100, a cooling flow path unit 200, and an end plate 300. More specifically, the rotor core 100 may be formed in a cylindrical shape, wherein a hollow hole 110 is formed through the central portion. The rotor shaft S may be inserted into the hollow hole 110. In addition, the cooling flow path unit 200 may receive cooling fluid O from the outer housing H of the rotor to cool the rotor core 100, and includes at least one first flow channel 210 formed to pass through the rotor core 100 in an axial direction, and cools the rotor core 100 by receiving cooling fluid O at one end and discharging cooling fluid O at the other end.

[0049] Furthermore, the end plate 300 of the rotor module 1000 with cooling structure disclosed herein can be configured such that a surface contacts both ends of the rotor core 100 in the axial direction. The end plate 300 can store a portion of the cooling fluid O directly injected from the housing H, disperse a portion of the cooling fluid O outward from the end plate 300 and the rotor core 100, i.e., toward the end coil C, and deliver a portion of the cooling fluid O into the interior of the rotor core 100, i.e., the first flow channel 210. Therefore, the fluid used to cool the existing end coil C can be used to directly cool the rotor assembly, and the stator can then be cooled separately, thereby solving the problems of heat generation and demagnetization.

[0050] In addition, such as Figure 2 As shown, the first flow channel 210 can have an elliptical flow cross-section, wherein the radial direction of the rotor core 100 is the minor axis. More specifically, the first flow channel 210 can be formed in the space between the hollow hole 110 of the rotor core 100 and the magnet M, and is formed as large as possible without interfering with the magnet M of the rotor core. Therefore, even if there is a slight tilt between the axial stacking stages of the rotor core 100 due to the design or assembly process, the first flow channel 210 can be formed to be connected in the axial direction.

[0051] Furthermore, the flow cross-section of the first flow channel 210 can be formed to extend within the periphery of the rotor core 100. That is, the flow cross-section of the first flow channel 210 can have an elliptical shape curved into an arc. Therefore, the centrifugal force of the cooling fluid O flowing through a single first flow channel 210 can be the same. Additionally, the radial height at which the cooling fluid O is directly injected from the housing H can be the same as the radial height of the first flow channel 210. This minimizes the dead zone during the flow of the cooling fluid O.

[0052] In the following text, reference will be made to Figures 3 to 7The endplate 300 of this disclosure will be described in more detail.

[0053] like Figure 3 As shown, the end plate 300 may include a second flow channel 220, one end of which is formed at the point where the cooling fluid O is injected, and the other end is in fluid communication with one end of the first flow channel 210 to deliver the cooling fluid O to the first flow channel 210. In this case, as Figure 4 As shown, the second flow channel 220 may include a first flow path 221 (2-1), a second flow path 222 (2-2), and a third flow path 223 (2-3). The first flow path 221 (2-1) is a groove formed in the axial direction of the rotor core 100, with one end opening towards the other surface of the end plate 300 to receive cooling fluid O. The second flow path 222 (2-2) is a groove formed in the radial direction of the rotor core 100, with one end in fluid communication with the first flow path 221 (2-1). The third flow path 223 (2-3) is a hole formed in the axial direction of the rotor core 100, with one end in fluid communication with the second flow path 222 (2-2) and the other end in fluid communication with the first flow channel 210.

[0054] 2-1 The first flow path 221 can be used to receive cooling fluid O from the outside, 2-2 the second flow path 222 can be used to store a portion of the cooling fluid O received from the first flow path 221, and 2-3 the third flow path 223 can be used to transport a portion of the cooling fluid O stored in the second flow path 222 to the interior of the rotor core 100, i.e., the first flow channel 210. By forming the second flow channel 220 in this way, the fluid cooling the existing end coils C can be used to directly cool the rotor assembly, and then the stator can be additionally cooled.

[0055] More specifically, the flow cross-sectional area of ​​the third flow path 223 (2-3) can be narrower than that of the first flow channel 210. This allows the cooling fluid O in the third flow path 223 to be smoothly transported to the first flow channel 210. Furthermore, the third flow path 223 (2-3) can communicate with the second flow path 222 (2-2) at a predetermined distance 'a' from the other end of the second flow path 222 (2-2) in the radial direction of the rotor core 100. Therefore, the cooling fluid O stored in the second flow path 222 (2-2) can flow towards the third flow path 223 (2-3) without flowing back towards the first flow path 221 (2-1), and can be transported to the first flow channel 210.

[0056] Furthermore, the end plate 300 may include a first fluid scattering flow channel 230, which is formed to pass through it at a predetermined angle θ1, without being perpendicular or parallel to the axial and radial directions of the rotor core 100. Two or more first fluid scattering flow channels 230 may be formed in the circumferential direction of the rotor core 100. By adjusting the number of first fluid scattering flow channels 230, the amount of recirculated and scattered cooling fluid O and the amount of cooling fluid O delivered to the rotor core 100, i.e., the first flow channel 210, can be adjusted.

[0057] Furthermore, one end of the first fluid scattering flow channel 230 can be connected to the second flow path 222, and the other end can open to another surface of the end plate 300. Additionally, the angle θ1 formed by the plane perpendicular to the axis of the rotor core 100 and the first fluid scattering flow channel 230 can be an acute angle less than 90 degrees. Therefore, the cooling fluid O scattered through the first fluid scattering flow channel 230 can be scattered radially outward toward the rotor core 100, i.e., the rotor assembly. This allows for maximum utilization of the cooling fluid O.

[0058] Furthermore, the first fluid scattering flow channel 230 can communicate with the second flow path 222 at a predetermined distance 'a' from the other end of the second flow path 222 along the radial direction of the rotor core 100. More specifically, the radial heights of the third flow path 223 and the first fluid scattering flow channel 230, which is in fluid communication with the second flow path 222, can be the same. Therefore, the cooling fluid O stored in the second flow path 222 can flow towards the first fluid scattering flow channel 230 without flowing back towards the first flow path 221, and can be scattered towards the rotor assembly.

[0059] In addition, such as Figure 5 As shown, 2-1 the first flow path 221 and 2-2 the second flow path 222 can be grooves formed continuously along the 360-degree circumference of the rotor core 100. That is, the cooling fluid O sprayed directly towards both ends of the rotor core 100 can be completely aggregated and mainly stored in one 2-1 first flow path 221 and one 2-2 second flow path 222. As a result, the maximum storage capacity of the cooling fluid O can be increased, and even if the cooling fluid O is sprayed unevenly at each direct spraying point, the cooling fluid O can be evenly distributed in the 2-3 third flow path 223 and the first flow channel 210, thereby ensuring uniform cooling in the entire circumferential direction of the rotor core 100.

[0060] Furthermore, the second flow path 222 can be formed as a single stage with a predetermined radial depth, without individual steps in the axial direction. By forming the second flow path 222 in such a shape, the cooling fluid O can be scattered in directions other than the tangential direction of the rotor core 100's rotation, thereby ensuring uniform oil distribution. Additionally, the ease of manufacturing the end plate 300 can be improved. Therefore, the end plate 300 can be used as a retainer and a negative balancing component.

[0061] In addition, such as Figure 6 As shown, the end plate 300 may include a second fluid scattering flow channel 240, which receives fluid from the first fluid scattering flow channel 210 and scatters the fluid toward the outside of the rotor core 100. The second fluid scattering flow channel 240 may be formed on the end plate 300 on which the first fluid scattering flow channel 230 is formed, and is formed at a position with a predetermined phase difference relative to the central axis of the rotor core 100 and the first fluid scattering flow channel 230. More specifically, the phase difference between the first fluid scattering flow channel 230 and the second fluid scattering flow channel 240 may be approximately 45 degrees. Therefore, cooling fluid O can be delivered from one end of the rotor core 100 in the axial direction to the other end and scattered into the first fluid scattering flow channel 230 and the second fluid scattering flow channel 240 at a specific phase, and can be delivered from the other end of the axial direction to one end and scattered into the first fluid scattering flow channel 230 and the second fluid scattering flow channel 240 at another phase.

[0062] More specifically, such as Figure 7 As shown, the second fluid scattering flow channel 240 can be composed of a first fluid scattering flow path 241 (2-1) and a second fluid scattering flow path 242 (2-2). The first fluid scattering flow path 241 (2-1) can be a groove recessed into a surface of the end plate 300, having one end in fluid communication with the first flow channel 210, and extending radially from that end along the rotor core 100. Furthermore, the second fluid scattering flow path 242 (2-2) can have one end in fluid communication with the first fluid scattering flow path 241 (2-1), and can be formed to pass through the end plate 300, such that the end plate 300 is inclined at a predetermined angle and is neither perpendicular to nor parallel to the axial and radial directions of the rotor core 100.

[0063] More specifically, 2-1 the first fluid scattering flow path 241 can be the space surrounded by the end plate 300 and the axial end surfaces of the rotor core 100, through which the cooling fluid O flowing in 2-1 the first fluid scattering flow path 241 provides secondary cooling to the rotor core 100. This maximizes the utilization of the cooling fluid O. Furthermore, 2-2 the second fluid scattering flow path 242 can form a predetermined angle θ2 relative to a plane perpendicular to the axis of the rotor core 100. In this case, θ2 can be an acute angle less than 90 degrees. Therefore, the cooling fluid O scattered through 2-2 the second fluid scattering flow path 242 can be scattered radially outward toward the rotor core 100, i.e., the rotor assembly. This maximizes the utilization of the cooling fluid O.

[0064] Furthermore, the 2-3 third flow paths 223 formed on the end plate 300 that contact one end surface of the rotor core 100 can be formed at a position that does not correspond to the 2-3 third flow paths 223 formed on the end plate 300 that contact the other end surface of the rotor core 100. In this case, the number of first flow channels 210 can be the sum of the number of 2-3 third flow paths 223 and the number of second fluid scattering flow channels 240. More specifically, the 2-3 third flow paths 223 and the second fluid scattering flow channels 240 can be formed at positions corresponding to the first flow channels 210, and are formed alternately in the circumferential direction.

[0065] Therefore, as Figure 8 As shown, when the cooling fluid O passes through one end and the other end of the rotor core 100 along the axial direction, regardless of whether the cooling fluid O is sprayed towards one end or the other end of the rotor core 100 along the axial direction, the cooling fluid O can pass through either the first fluid scattering flow channel 230 or the second fluid scattering flow channel 240. That is, in a specific phase, such as Figure 1 As shown, cooling fluid can flow from one end of the rotor core 100 along the axial direction ( Figure 1 (left side) to the other end ( Figure 1 The right side) is conveyed, and through one end set in the axial direction ( Figure 1 The first fluid scattering flow channel 230 on the left side and the other end (in the axial direction) Figure 1 The second fluid scattering flow channel 240 (on the right side) sprays, or as Figure 8 As shown, cooling fluid can flow from the other end of the rotor core 100 in the axial direction ( Figure 8 (right side) towards one end ( Figure 8 The left side) is conveyed, and through the other end set in the axial direction ( Figure 8 The first fluid scattering flow channel 230 on the right side and one end disposed in the axial direction ( Figure 8The second fluid scattering flow channel 240 (on the left side) is injected.

[0066] In this case, more specifically, the cooling fluid O can flow in the sequence of 2-1 first flow path 221, 2-2 second flow path 222, and first fluid scattering flow channel 230, and then be recirculated and scattered; or it can flow in the sequence of 2-1 first flow path 221, 2-2 second flow path 222, first flow channel 210, and second fluid scattering flow channel 240, and then be scattered after passing through the rotor core 100. This improves the cooling efficiency of the end coil C.

[0067] In the rotor module with cooling structure of this disclosure having the above configuration, the problems of heat generation and demagnetization can be solved by installing end plates with oil storage, diffusion and transmission functions on both ends of the rotor core, and using the existing oil of the cooling end coils to directly cool the rotor assembly together, and then additionally cooling the stator.

[0068] The technical spirit of this disclosure should not be construed as limited to the embodiments described above. Not only are its applications diverse, but those skilled in the art can make various modifications without departing from the spirit of this disclosure as claimed. Therefore, any improvements and variations that are obvious to those skilled in the art fall within the scope of this disclosure.

Claims

1. A rotor module with a cooling structure, the rotor module comprising: A rotor core, the rotor core being formed in a cylindrical shape and including a hollow hole passing through the central portion of the rotor core; Cooling flow path unit, in which cooling fluid that cools the rotor core flows; as well as An end plate, wherein a first surface of the end plate contacts a first end and a second end of the rotor core in the axial direction of the end plate. The cooling flow path unit includes at least one first flow channel, which is configured to axially pass through the rotor core. The at least one first flow channel includes a first end and a second end, wherein cooling fluid flows into the first end of the at least one first flow channel and is discharged through the second end of the at least one first flow channel to cool the rotor core.

2. The rotor module according to claim 1, wherein The end plate includes a second flow channel. The first end of the second flow channel is located at the point where the cooling fluid is sprayed, and the second end of the second flow channel is in fluid communication with the first end of the first flow channel to deliver the cooling fluid to the first flow channel.

3. The rotor module according to claim 2, wherein, The second flow channel includes: A first flow path, wherein the first flow path is a groove disposed in the axial direction of the rotor core, wherein one end of the first flow path opens toward the second surface of the end plate to receive the cooling fluid; A second flow path, which is a groove disposed in the axial direction of the rotor core, wherein a first end of the second flow path is in fluid communication with the first flow path; and The third flow path is a hole disposed in the axial direction of the rotor core, wherein a first end of the third flow path is in fluid communication with the second flow path, and a second end of the third flow path is in fluid communication with the first flow channel.

4. The rotor module according to claim 3, wherein, The first flow path and the second flow path are grooves continuously arranged in the circumferential direction of the rotor core.

5. The rotor module according to claim 3, wherein, The flow cross-sectional area of ​​the third flow path is narrower than that of the first flow channel.

6. The rotor module according to claim 3, wherein, The third flow path disposed on the end plate that contacts the first end surface of the rotor core is located at a position that does not correspond to the third flow path disposed on the end plate that contacts the second end surface of the rotor core.

7. The rotor module according to claim 3, in, The end plate includes a first fluid scattering flow channel, which is configured to pass through the end plate at a predetermined angle, and is neither perpendicular to nor parallel to the axial and radial directions of the rotor core. The first fluid scattering flow channel includes a first end that is in fluid communication with the second flow path and a second end that opens toward the second surface of the end plate.

8. The rotor module according to claim 7, wherein, The first fluid scattering flow channel is in fluid communication with the second flow path at a predetermined distance from the second end of the second flow path in the radial direction of the rotor core.

9. The rotor module according to claim 7, wherein, The end plate includes a second fluid scattering flow channel, which receives fluid from the first flow channel and scatters the fluid to the outside of the rotor core. The second fluid scattering flow channel is positioned relative to the central axis of the rotor core at a location with a predetermined phase difference from the first fluid scattering flow channel.

10. The rotor module according to claim 9, wherein, The second fluid scattering flow channel includes: A first fluid scattering flow path, wherein the first fluid scattering flow path is a groove recessed into the first surface of the end plate, wherein one end of the first fluid scattering flow path is in fluid communication with the first flow channel, and the first fluid scattering flow path is configured to extend radially from one end along the radial direction of the rotor core; and A second fluid scattering flow path, wherein one end of the second fluid scattering flow path is in fluid communication with the first fluid scattering flow path, and the second fluid scattering flow path is configured to pass through the end plate at a predetermined angle, without being perpendicular or parallel to the axial direction and the radial direction of the rotor core.

11. The rotor module according to claim 1, further comprising a magnet embedded in the rotor core. in, The first flow channel is disposed between the hollow hole and the magnet and has an elliptical flow cross-section. The radial direction of the rotor core is the short axis.

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