Cooling mechanism for drive motor
By forming an oil supply path and injection holes between the stator and the motor housing, and using retaining rings to achieve uniform injection of cooling oil, the problem of limited cooling range is solved, cooling efficiency is improved and costs are reduced.
Patent Information
- Application Number
- CN202520277491.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Priority Date
- 2024-02-21
- Filing Date
- 2025-02-20
- Publication Date
- 2026-02-03
- Estimated Expiration
- 2035-02-20
AI Technical Summary
In existing drive motor cooling structures, the limited spray range of cooling oil results in insufficient cooling efficiency, and additional oil guide components increase manufacturing costs and process complexity.
An oil supply path and injection holes are formed between the stator and the motor housing. Cooling oil is directly sprayed onto the stator using a retaining ring. The retaining ring design achieves uniform oil distribution.
It achieves uniform spraying of cooling oil, improves cooling efficiency, reduces manufacturing costs and process complexity, and is suitable for motors of various specifications.
Smart Images
Figure CN223872158U_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to a drive motor having a cooling mechanism that directly cools the drive motor with cooling oil, and more specifically, to a cooling mechanism for a drive motor that sprays cooling oil onto the stator using a retaining ring that secures the stator to the motor housing. Background Technology
[0002] If a drive motor used in an electric vehicle (EV) or hybrid electric vehicle (HEV) has a higher output while maintaining the same weight and size, then from a vehicle perspective, such a drive motor can improve fuel efficiency. However, to achieve a higher output, it may be necessary to increase the current, i.e., the input. However, if current flows through the coils inside the motor, heat may be generated due to the coil resistance. Therefore, it is necessary to reduce the heat generated in the drive motor.
[0003] Methods for cooling the coils inside a drive motor can be broadly categorized into three types. The first method is air cooling, which uses heat sinks exposed to the outside. The second method is water cooling, which indirectly cools the coils by forming water paths within the housing or similar structure. The third method is oil cooling, which directly cools the coils inside the motor using oil (which is an insulating material).
[0004] Recently, with the increasing demand for high-efficiency and high-output drive motors for the development of high-performance electric vehicles, there has been a growing number of cases using drive motors that employ direct cooling methods utilizing cooling oil.
[0005] There are two methods for directly cooling the inside of the motor. One method is to inject an appropriate amount of oil into the motor and pump the oil using a stirring type with a rotating body, while the other method is to allow the oil to flow from top to bottom or to spray the oil from top to bottom using a jet type.
[0006] like Figure 1 As shown, the injection type can supply oil to the cooling oil pipe 11 to concentrate the cooling oil and spray it onto the stator assembly 10, and form an oil injection hole 13 at the end of the pipe 11 to spray the oil onto the target. The sprayed oil can flow through the coils 15 of the stator assembly 10. In this case, since the oil flows by gravity when the motor is mounted on the vehicle, the sprayed oil may drop. Figure 1 Arrow D in the diagram indicates the direction of oil injection.
[0007] Meanwhile, the stator assembly 10 of the drive motor can have a circular shape, so that the oil injected from the top can only flow downwards, remaining adjacent to the injection hole 13, thereby limiting the cooling range.
[0008] To improve this limitation / problem, a conventional technique has been publicly disclosed that includes an oil guide to spray oil by dividing the oil into several paths, thereby allowing the oil flowing into the oil guide to be sprayed evenly onto the stator assembly 10.
[0009] Conventional cooling structures for drive motors that include the oil guides described above may also include oil guiding features that act as resistance to oil flow, resulting in insufficient improvement in cooling efficiency and potentially requiring additional processes to manufacture and assemble the oil guides, thereby increasing manufacturing and process costs. Utility Model Content
[0010] One object of this disclosure is to provide a cooling mechanism for driving a motor, wherein an oil path and a spray hole are formed on a retaining ring for securing a stator inserted into a motor housing, and an oil supply groove is formed between the motor housing and the stator, the end of the oil supply groove communicating with the oil path of the retaining ring, thereby supplying cooling oil to the stator through the retaining ring.
[0011] This utility model relates to non-limiting examples as defined in the following clauses.
[0012] Clause 1. A cooling mechanism for driving a motor, the cooling mechanism comprising:
[0013] A cylindrical stator, the cylindrical stator having coils wound around it and including a first side and a second side;
[0014] A cylindrical motor housing having a sealed first side and an open second side, and housing the cylindrical stator within the cylindrical motor housing;
[0015] A retaining ring, which engages with the inner circumferential surface of the second side of the cylindrical motor housing to have a radially inwardly projecting side from the inner circumferential surface of the cylindrical motor housing, and secures the second side of the cylindrical stator by means of a circumferential surface having a protrusion that contacts the upper surface of the cylindrical stator; and
[0016] An oil supply path is formed between the outer circumferential surface of the cylindrical stator and the inner circumferential surface of the cylindrical motor housing to supply oil to the retaining ring.
[0017] The retaining ring includes an injection path having an upstream side in fluid communication with the oil supply path and a downstream side passing through the inner circumferential surface of the retaining ring and exposed to the second side of the cylindrical stator.
[0018] Clause 2. The cooling mechanism for driving a motor as described in Clause 1, wherein the oil supply path is formed in the axial direction of the cylindrical stator, the oil supply path has a predetermined width in the circumferential direction of the cylindrical stator, and is radially recessed from the outer circumferential surface of the cylindrical stator.
[0019] Clause 3. The cooling mechanism for driving a motor as described in Clause 1, wherein the oil supply path is formed in the axial direction of the cylindrical stator, the oil supply path has a predetermined width in the circumferential direction of the cylindrical stator, and is radially recessed outward from the inner circumferential surface of the cylindrical motor housing.
[0020] Clause 4. The cooling mechanism for driving a motor as described in Clause 1, wherein the oil injection path includes:
[0021] The inflow path is recessed upward in the circumferential direction from the lower surface of the retaining ring and includes a first end and a second end;
[0022] An outflow path, the outflow path passing radially inward from the second end of the inflow path through the retaining ring; and
[0023] A jet orifice is formed at the downstream end of the outflow path.
[0024] Clause 5. The cooling mechanism for driving a motor as described in Clause 4, wherein the inflow path is formed as a closed curve in the circumferential direction of the cylindrical stator.
[0025] Clause 6. The cooling mechanism for driving a motor as described in Clause 4, wherein the inflow path is a plurality of inflow paths, and
[0026] The plurality of inflow paths each have a predetermined width in the circumferential direction of the retaining ring and are configured to be spaced apart from each other in the circumferential direction of the retaining ring.
[0027] Clause 7. The cooling mechanism for driving a motor as described in Clause 4, wherein the outflow path is a plurality of outflow paths, and
[0028] The plurality of outflow paths are equally spaced in the circumferential direction of the cylindrical stator, or have variable spacing based on the heat-generating region of the cylindrical stator.
[0029] Clause 8. The cooling mechanism for driving a motor as described in Clause 4, wherein the outflow path has an upstream end in fluid communication with the inflow path, the outflow path has a predetermined width in the circumferential direction of the cylindrical stator, and is recessed upward from the lower surface of the retaining ring.
[0030] Clause 9. The cooling mechanism for driving a motor as described in Clause 8, wherein the outflow path has a longer recessed length toward the radially inner side of the retaining ring than toward the radially outer side of the retaining ring.
[0031] Clause 10. A cooling mechanism for driving a motor as described in Clause 9, wherein the outflow path has a smaller circumferential width toward the radially inner side of the retaining ring than toward the radially outer side of the retaining ring.
[0032] Clause 11. The cooling mechanism for driving a motor as described in Clause 9, wherein the outflow path includes an increased width near the injection orifice.
[0033] Clause 12. The cooling mechanism for driving a motor as described in Clause 1, wherein the oil injection path includes:
[0034] An outflow path, the outflow path being recessed upward from the radially inner lower surface of the retaining ring; and
[0035] An injection hole is formed in the radial inner end of the outflow path.
[0036] Clause 13. The cooling mechanism for driving a motor as described in Clause 12, wherein the oil injection path includes a top that slopes upward toward its downstream side to increase the injection distance.
[0037] Clause 14. The cooling mechanism for driving a motor as described in Clause 12, wherein the outflow path is a plurality of outflow paths, and
[0038] The plurality of outflow paths are equally spaced in the circumferential direction of the cylindrical stator, or have variable spacing based on the heat-generating region of the cylindrical stator.
[0039] Other features and aspects of this disclosure will become clear from the following figures and detailed description. Attached Figure Description
[0040] Figure 1 This is a view showing the interior of a drive motor that uses a jet cooling method.
[0041] Figure 2 This is a partial cross-sectional perspective view of a drive motor having a cooling mechanism for the drive motor according to an embodiment of the present disclosure.
[0042] Figure 3 This is a partially enlarged perspective view of a retaining ring according to an embodiment of the present disclosure.
[0043] Figure 4 This is a partially enlarged perspective view showing a cooling mechanism for driving a motor according to a first embodiment of the present disclosure.
[0044] Figure 5 This is a partially enlarged perspective view showing the oil path of the retaining ring according to a first embodiment of the present disclosure.
[0045] Figure 6 This is a partially enlarged perspective view showing the oil supply path according to a second embodiment of the present disclosure.
[0046] Figure 7 This is a partially enlarged cross-sectional perspective view showing the oil path of the retaining ring according to a second embodiment of the present disclosure.
[0047] Figure 8 This is a partially enlarged perspective view showing the oil flow path of a retaining ring according to a second embodiment of the present disclosure.
[0048] Figure 9 This is a partially enlarged perspective view showing the retaining ring and stator according to a second embodiment of the present disclosure.
[0049] Figure 10 This is a partially enlarged cross-sectional perspective view showing the oil path of the retaining ring according to the third embodiment of the present disclosure.
[0050] Figure 11 This is a partially enlarged perspective view showing the oil passage of a retaining ring according to a third embodiment of the present disclosure. Detailed Implementation
[0051] The embodiments of this disclosure are described in detail below with reference to the accompanying drawings.
[0052] Figure 2 A partial cross-sectional perspective view of a drive motor having a cooling mechanism for the drive motor according to an embodiment of the present disclosure is shown. Furthermore, Figure 3 A partially enlarged perspective view of a retaining ring 300 according to an embodiment of the present disclosure is shown.
[0053] As shown in the figure, the cooling mechanism 1000 for driving the motor may include a cylindrical stator 100 with coils wound around it, a cylindrical motor housing 200 housing the stator 100, a retaining ring 300 fitted into the upper inner surface of the motor housing 200 to secure the upper side of the stator 100 housed in the motor housing 200, and an oil supply device for supplying oil to the retaining ring 300, although this oil supply device is not shown in the figure. The oil supply device may be, for example, an oil pump for circulating oil. Therefore, oil pumped from the oil pump can flow along a path formed in the motor housing 200 through the gap between the stator 100 and the motor housing 200, and supply oil to the retaining ring 300.
[0054] The cylindrical motor housing 200 may have a sealed bottom and an open top.
[0055] A cylindrical stator 100 with a predetermined thickness can wind a coil around its inner circumferential surface and apply current to the coil, thereby causing a rotor (not shown) disposed on the inner side of the stator 100 to rotate.
[0056] The retaining ring 300 can be formed into a ring shape having a predetermined width in the radial direction. When the radially outer circumference of the retaining ring 300 is fitted into the retaining ring retaining groove 210 that is radially recessed outward from the inner circumferential surface of the upper side of the motor housing 200, the retaining ring 300 can have a radially inner side that protrudes inward from the inner circumferential surface of the motor housing 200. Furthermore, the retaining ring 300 can have a radially inner lower surface that protrudes and circumferentially contacts the upper surface of the stator 100. Therefore, when the stator 100 is mounted on the motor housing 200, the stator 100 can be fixed to the motor housing 200 by restricting its upward movement.
[0057] Here, the retaining ring 300 may include an oil injection path 310 formed therein, thereby receiving oil supplied to an oil supply path 400 formed between the outer circumferential surface of the stator 100 and the inner circumferential surface of the motor housing 200, so as to spray the oil onto the coil end 110 on the upper side of the stator 100. Figure 3 Arrow A in the diagram represents cooling oil.
[0058] The cooling mechanism 1000 having the above-described structure is described in detail with reference to the accompanying drawings.
[0059] Figure 4 A partially enlarged perspective view of a cooling mechanism 1000 for a drive motor according to a first embodiment of the present disclosure is shown, and Figure 5 A partially enlarged perspective view of the oil injection path 310 of the retaining ring according to a first embodiment of the present disclosure is shown.
[0060] As shown in the figure, an oil supply path 400 can be formed between the inner circumferential surface of the motor housing 200 and the outer circumferential surface of the stator 100. The oil supply path 400 can have a predetermined width in the circumferential direction and is radially recessed from the outer circumferential surface of the stator 100. Although not shown in the figure, in another embodiment, the oil supply path can be radially recessed from the inner circumferential surface of the motor housing 200.
[0061] Here, the upper end of the oil supply path 400 can contact the lower surface of the retaining ring 300, and the oil injection path 310 can include an inflow path 311 that is recessed upward in the circumferential direction from the lower surface of the retaining ring 300 and an outflow path 312 that passes radially inward through the retaining ring 300 from the downstream end (i.e., the upper end) of the inflow path 311. The upstream side of the inflow path 311 can communicate with the oil supply path 400 and distribute the oil supplied from the oil supply path 400 in the circumferential direction of the retaining ring 300. The plurality of outflow paths 312 can be configured to be spaced apart from each other in the circumferential direction of the retaining ring 300 and can have injection holes 315 formed at the downstream end to uniformly spray the oil supplied through the inflow path 311 onto the coil end 110 on the upper side of the stator 100.
[0062] The outflow paths 312 can be spaced apart from each other while having equal intervals, or they can be arranged more densely in areas where relatively high heat is generated if necessary.
[0063] With the above construction, oil can be evenly sprayed onto the upper coil end 110 of the stator 100, or concentratedly sprayed onto a specific area of the coil end 110, by using only the retaining ring 300 without using any separate oil guide.
[0064] Figure 6 A partially enlarged perspective view of the oil supply path 410 according to a second embodiment of the present disclosure is shown. Additionally, Figure 7 A partially enlarged cross-sectional perspective view of the oil injection path 320 of the retaining ring 300 according to the second embodiment of the present disclosure is shown, and Figure 8 A partially enlarged perspective view of the oil injection path 320 of the retaining ring 300 according to the second embodiment of this disclosure is shown. Additionally, Figure 9 A partially enlarged perspective view of the stator 100 and retaining ring 300 according to a second embodiment of the present disclosure is shown.
[0065] Reference Figure 6 Multiple oil supply paths 410 can be formed in the vertical longitudinal direction, recessed inward from the outer circumferential surface of the stator 100, and arranged to be spaced apart from each other in the circumferential direction. As shown, the multiple oil supply paths 410 can have a narrow spacing, especially in areas where a relatively large amount of heat is generated.
[0066] Additionally, refer to Figures 7 to 9The injection path 320 may include an inflow path 321 that is circumferentially recessed upward from the lower surface of the retainer 300 and an outflow path 322 that radially passes inward through the retainer 300 from the downstream end (i.e., the upper end) of the inflow path 321. The outflow path 322, provided on a plurality of densely arranged injection paths 410, may have the following configuration to increase injection flow rate and injection distance: The outflow path 322 may have an upstream end in fluid communication with the inflow path 321, may have a predetermined width in the circumferential direction, and may be recessed upward from the lower surface of the retainer 300. Specifically, the outflow path 322 may have a longer recessed length toward its radially inward side (i.e., its downstream side). That is, the outflow path 322 may have an increased vertical width toward its downstream side. Therefore, since the injection hole 325 formed at the downstream end of the outflow path 322 has an increased area, a large amount of oil supplied from the injection path 410 can be smoothly injected. Furthermore, the outflow path 322 may have an upwardly sloping top towards its downstream side, thereby increasing the spray distance.
[0067] In one example, there may be multiple inflow paths, each corresponding to a multiple oil supply path. Each of the multiple inflow paths has a predetermined width in the circumferential direction of the retaining ring and is spaced apart from each other in the circumferential direction of the retaining ring.
[0068] Figure 10 A partially enlarged cross-sectional perspective view of the oil injection path 330 of the retaining ring 300 according to the third embodiment of this disclosure is shown, and Figure 11 A partially enlarged perspective view of the oil injection path 330 of the retaining ring 300 according to the third embodiment of the present disclosure is shown.
[0069] Meanwhile, the injection path 330 according to the second embodiment can have a reduced oil flow rate because the path has an increased cross-sectional area towards its downstream side. To solve this problem, the injection path 330 of the retaining ring 300 according to the third embodiment can be constructed as follows.
[0070] The injection path 330 may include an outflow path 332 that is in fluid communication with the supply path 410. Here, the outflow path 332 provided on the densely arranged multiple supply paths 410 may have the following configuration to maintain the oil injection speed while increasing the injection flow rate and injection distance.
[0071] The outflow path 332 can be formed on the radially inner side of the retaining ring 300 and recessed upward from the lower surface of the retaining ring 300. Furthermore, the outflow path 332 can have a longer recessed length towards the radially inner side (i.e., its downstream side) of the retaining ring than towards the radially outer side. Additionally, the outflow path 322 can have a smaller circumferential width towards the radially inner side (i.e., its downstream side) of the retaining ring than towards the radially outer side. Therefore, the injection path 330 can directly receive oil from the supply path 410 to the outflow path 332 and maintain the cross-sectional area of the outflow path 322, thereby maintaining or increasing the oil injection velocity. Furthermore, the outflow path 322 can have a further increased width near the injection orifice 335, thereby increasing the oil injection area.
[0072] The cooling mechanism for driving a motor constructed as described above, according to this disclosure, can reduce the manufacturing or process costs of forming the cooling mechanism by using a retaining ring for securing the stator to the motor housing to spray cooling oil onto the stator, without requiring any separate construction for spraying oil onto the stator.
[0073] Because the injection position or supply flow of the cooling oil can be easily adjusted by modifying the design of the retaining ring, the cooling mechanism for drive motors according to this disclosure can be applied to motors of various specifications that require intensive cooling at specific locations at low cost.
[0074] The spirit of this disclosure should not be limited to the embodiments described above. This disclosure can be applied to various fields and can be modified by those skilled in the art without departing from the scope of this disclosure as claimed in the claims. Therefore, it will be apparent to those skilled in the art that these changes and modifications fall within the scope of this disclosure.
Claims
1. A cooling mechanism for driving a motor, the cooling mechanism comprising: a cylindrical stator wound with a coil and including a first side and a second side; a cylindrical motor housing having a sealed first side, an open second side, and accommodating the cylindrical stator therein; a circlip fitted into an inner circumferential surface of the second side of the cylindrical motor housing to have a radially inner side protruding inward from the inner circumferential surface of the cylindrical motor housing, and fixing the second side of the cylindrical stator by having a surface protruding and contacting a circumference of an upper surface of the cylindrical stator; and an oil supply path formed between an outer circumferential surface of the cylindrical stator and the inner circumferential surface of the cylindrical motor housing to supply oil to the circlip through the oil supply path, characterized in that the circlip includes an oil injection path having an upstream side in fluid communication with the oil supply path and a downstream side passing through an inner circumferential surface of the circlip and exposed to the second side of the cylindrical stator. The oil supply path is formed in an axial direction of the cylindrical stator, has a predetermined width in a circumferential direction of the cylindrical stator, and is recessed radially inward from the outer circumferential surface of the cylindrical stator.
2. The cooling mechanism for driving a motor according to claim 1, characterized by, The oil supply path is formed in an axial direction of the cylindrical stator, has a predetermined width in a circumferential direction of the cylindrical stator, and is recessed radially outward from the inner circumferential surface of the cylindrical motor housing.
3. The cooling mechanism for driving a motor according to claim 1, characterized by, The oil injection path includes:
4. The cooling mechanism for driving a motor according to claim 1, characterized by, an inflow path recessed upward in a circumferential direction from a lower surface of the circlip and including a first end and a second end; an outflow path passing radially inward from the second end of the inflow path through the circlip; and an injection hole formed at a downstream end of the outflow path. The inflow path is formed as a closed curve in a circumferential direction of the cylindrical stator.
5. The cooling mechanism for driving a motor according to claim 4, characterized by, The inflow path is a plurality of inflow paths, and 6. The cooling mechanism for driving a motor according to claim 4, wherein wherein the plurality of inflow paths each have a predetermined width in a circumferential direction of the circlip and are disposed to be spaced apart from each other in the circumferential direction of the circlip. The outflow path is a plurality of outflow paths, and 7. The cooling mechanism for driving a motor according to claim 4, wherein wherein the plurality of outflow paths have an equal spacing in a circumferential direction of the cylindrical stator, or a variable spacing based on a region of the cylindrical stator that generates heat. The outflow path has an upstream end in fluid communication with the inflow path, has a predetermined width in a circumferential direction of the cylindrical stator, and is recessed upward from a lower surface of the circlip.
8. The cooling mechanism for driving a motor according to claim 4, wherein The outflow path has a longer recessed length toward a radially inner side of the circlip than toward a radially outer side of the circlip.
9. The cooling mechanism for driving a motor according to claim 8, wherein The outflow path has a smaller circumferential width toward a radially inner side of the circlip than toward a radially outer side of the circlip.
10. The cooling mechanism for driving a motor according to claim 9, wherein The outflow path includes an increased width in the vicinity of the injection hole.
11. The cooling mechanism for driving a motor according to claim 9, wherein The oil injection path includes:
12. The cooling mechanism for driving a motor according to claim 1, characterized by, An outflow path which is recessed upward from a radially inner lower surface of the collar; and An injection hole formed in a radially inner end of the outflow path.
13. The cooling mechanism for driving a motor according to claim 12, characterized by, The oil injection path includes a top portion which is inclined upward toward a downstream side thereof to increase an injection distance.
14. The cooling mechanism for driving a motor according to claim 12, wherein The outflow path is a plurality of outflow paths, and The plurality of outflow paths have equal intervals in a circumferential direction of the cylindrical stator, or variable intervals based on a region of the cylindrical stator which generates heat.