Rotor assembly, coaxial electric driving system and vehicle
By incorporating internal and external helical grooves and multiple oil passages on the rotor shaft, the problems of poor sealing and coolant leakage in coaxial electric drive systems are solved, achieving efficient lubrication and sealing, reducing costs and simplifying the process.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- DEEPAL AUTOMOBILE TECH CO LTD
- Filing Date
- 2025-05-30
- Publication Date
- 2026-04-24
AI Technical Summary
In coaxial electric drive systems, the sealing effect between the rotor shaft and the junction box cover is poor, and coolant flows out from the gap between the rotor shaft and the reducer drive shaft, resulting in a complex oil circuit structure that affects cooling and lubrication, and also increases costs.
An inner and outer spiral groove is provided on the rotor shaft. A spiral seal is formed with the reducer drive shaft and junction box cover through a spiral sealing structure. Combined with the design of multiple interconnected oil passages, effective sealing and lubrication of the coolant are achieved.
It effectively prevents coolant leakage, ensures reasonable distribution of coolant flow, improves sealing reliability and lubrication effect, reduces costs, and simplifies manufacturing and assembly processes.
Smart Images
Figure CN224164745U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of automotive electric drive systems, specifically relating to a rotor assembly, a coaxial electric drive system, and a vehicle. Background Technology
[0002] The drive motor assembly and the reducer assembly are the two core components of the automotive electric drive system. The drive motor assembly generally includes a housing, stator assembly, rotor assembly, rear end cover and junction box cover; the reducer assembly generally includes a differential assembly, reducer drive shaft, planetary gear assembly and planetary carrier assembly, etc. At present, the research on the power system of new energy electric vehicles pays more attention to high integration, system lightweighting, high power density and high reliability. Therefore, the coaxial electric drive system has become the focus of industry research. The special structure of the coaxial electric drive system (highly integrated structure) brings some problems, such as: (1) The rotor shaft and the junction box cover are sealed by adding a sealing ring, which is costly and the sealing effect is not good because the rotor shaft rotates relative to the junction box cover; (2) The reducer drive shaft runs through the entire rotor shaft in the rotor assembly. The coolant entering the rotor shaft will flow out from the gap between the rotor shaft and the reducer drive shaft, which will affect the oil flow distribution of the entire electric drive system; (3) The oil circuit structure of the entire coaxial electric drive system is complex and has high flow resistance, which affects the cooling and lubrication effect of the stator assembly and the rotor assembly. Utility Model Content
[0003] The purpose of this invention is to provide a rotor assembly, a coaxial electric drive system, and a vehicle to prevent coolant from flowing out from the gap between the rotor shaft and the reducer drive shaft, while reducing costs.
[0004] In a first aspect, this utility model provides a rotor assembly, which includes a rotor shaft. The rotor shaft has multiple radial oil outlet holes and a central hole through which a reducer drive shaft passes and through which coolant flows. The multiple radial oil outlet holes communicate with the central hole. An inner spiral groove is provided at the helical tooth end of the rotor shaft near the radial oil outlet holes, allowing the rotor shaft to form a spiral seal with the reducer drive shaft via the inner spiral groove and coolant. An outer spiral groove is provided at the end of the rotor shaft, allowing the rotor shaft to form a spiral seal with the junction box cover via the outer spiral groove and coolant.
[0005] Preferably, the inner spiral groove rotates to the left, and the oil venting direction of the spiral seal formed by the rotor shaft and the reducer drive shaft through the inner spiral groove is from right to left; the outer spiral groove rotates to the left, and the oil venting direction of the spiral seal formed by the rotor shaft and the junction box cover through the outer spiral groove is from right to left.
[0006] Secondly, this utility model provides a coaxial electric drive system, comprising: a housing, a stator assembly fixed within the housing, a rear end cover connected to the housing, a junction box cover connected to the rear end cover, a rotor assembly located within the housing with its rotor shaft cooperating with the junction box cover, and a reducer drive shaft passing through the junction box cover and coaxially assembled within the rotor shaft, wherein a rotor oil passage exists between the reducer drive shaft and the rotor shaft. The rotor assembly is the aforementioned rotor assembly.
[0007] Preferably, the housing has interconnected housing oil passages and motor oil inlet passages; the rear end cover has sequentially interconnected end cover first oil passage, end cover second oil passage, and end cover third oil passage; the junction box cover has sequentially interconnected box cover first oil passage, box cover second oil passage, and box cover bearing chamber. The housing oil passages are connected to the end cover first oil passage and sealed at the connection point by a first sealing ring; the end cover third oil passage is connected to the box cover first oil passage and sealed at the connection point by a second sealing ring; the box cover bearing chamber is connected to the rotor oil passage, and the rotor shaft forms a spiral seal with the junction box cover through an outer spiral groove, coolant, and an inner spiral groove, coolant, and reducer drive shaft. Through multiple interconnected oil passages and sealing structures, efficient lubrication (cooling) and sealing of the coaxial electric drive system are achieved.
[0008] Preferably, the oil passage in the housing is located at the upper left or upper right of the housing, and the angle α between it and the vertical plane satisfies: 0°<α≤45°, thereby improving the spraying effect of the oil passage in the housing.
[0009] Preferably, the centerline of the first oil passage in the end cover is parallel to the horizontal plane, the centerline of the second oil passage in the end cover forms an angle of 75° with the centerline of the first oil passage, and the centerline of the third oil passage in the end cover forms an angle of 105° with the centerline of the second oil passage. This angle design guides the coolant to flow along a specific path to cover more areas and improve cooling uniformity.
[0010] Preferably, the centerline of the first oil passage in the cover is parallel to the horizontal plane, and the angle between the centerline of the second oil passage in the cover and the centerline of the first oil passage is 68°. This angle design guides the coolant to flow along a specific path to cover more areas and improve cooling uniformity.
[0011] Preferably, the length of the first oil channel of the end cap is 15mm, the length of the second oil channel of the end cap is 85mm, and the length of the third oil channel of the end cap is 47mm; the length of the first oil channel of the box cover is 10mm, and the length of the second oil channel of the box cover is 58mm.
[0012] Preferably, the center lines of the housing oil passage, the first oil passage of the end cap, the second oil passage of the end cap, the third oil passage of the end cap, the first oil passage of the cover, and the second oil passage of the cover are all located on the same plane. By aligning the center lines of each oil passage on the same plane, the oil path is shortened, achieving a compact and integrated oil path system layout, simplifying manufacturing and assembly processes, while ensuring smooth flow and precise distribution of lubricating oil (coolant), improving lubrication and cooling efficiency, and enhancing system reliability.
[0013] Thirdly, this utility model provides a vehicle that includes the aforementioned coaxial electric drive system.
[0014] This utility model has the following effects:
[0015] (1) The rotor shaft forms a spiral seal with the junction box cover through the outer spiral groove, coolant and the junction box cover. It uses the pumping effect generated by the outer spiral groove when the rotor shaft rotates to prevent the lubricating oil (coolant) from leaking. Without adding any other structural parts and accessories, it avoids the coolant from flowing out from the gap between the rotor shaft and the junction box cover, thereby improving the sealing reliability of the rotor shaft and the junction box cover while reducing the cost.
[0016] (2) The rotor shaft forms a spiral seal with the reducer drive shaft through the inner spiral groove and coolant. It uses the pumping effect generated by the inner spiral groove when the rotor shaft rotates to prevent the lubricating oil (coolant) from leaking, and avoids the coolant from flowing out from the gap between the rotor shaft and the reducer drive shaft, thus ensuring the reasonable distribution of flow and ultimately ensuring the stable operation of the motor. At the same time, the spiral seal does not require the addition of other structural accessories (such as sealing rings), and the structure is simple, has no related quality risks, and saves costs.
[0017] (3) The motor oil inlet, housing oil passage, end cover first oil passage, end cover second oil passage, end cover third oil passage, box cover first oil passage, box cover second oil passage, and box cover bearing chamber on the coaxial electric drive system are connected in sequence, which ensures that the lubricating oil (coolant) can be smoothly delivered to the key parts inside the motor (such as bearings), providing good lubrication for motor operation and reducing component wear; at the same time, each oil passage has a compact structure, and the assembly process of connecting the housing oil passage with the end cover first oil passage and the end cover third oil passage with the box cover first oil passage is simple. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of the rotor assembly in an embodiment of the present invention.
[0019] Figure 2 This is a schematic diagram of the coaxial electric drive system in an embodiment of the present invention.
[0020] Figure 3This is an enlarged view of the spiral sealing portion formed by the rotor shaft and the junction box cover in an embodiment of this utility model.
[0021] Figure 4 This is an enlarged view of the spiral seal formed by the rotor shaft and the reducer transmission shaft in an embodiment of this utility model.
[0022] Figure 5 This is a front view of the housing of the coaxial electric drive system in an embodiment of this utility model.
[0023] Figure 6 This is a left view of the housing of the coaxial electric drive system in an embodiment of this utility model.
[0024] Figure 7 This is a schematic diagram of the structure of the rear end cover of the coaxial electric drive system in an embodiment of this utility model.
[0025] Figure 8 This is a schematic diagram of the junction box cover of the coaxial electric drive system in an embodiment of this utility model.
[0026] Figure 9 This is a schematic diagram of the oil circuit routing of the coaxial electric drive system in this embodiment of the present invention. Detailed Implementation
[0027] To gain a more detailed understanding of the features and technical content of the embodiments of this utility model, the implementation of the embodiments of this utility model will be described in detail below with reference to the accompanying drawings. The accompanying drawings are for reference and illustration only and are not intended to limit the embodiments of this utility model.
[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing embodiments of the invention only and is not intended to limit the scope of the invention.
[0029] In the following description, references are made to “some embodiments,” which describe a subset of all possible embodiments. However, it is understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.
[0030] like Figures 1 to 4As shown, the rotor assembly in this embodiment of the present invention includes a rotor shaft 11. The rotor shaft 11 has multiple radial oil outlet holes 111 and a central hole 112 through which the reducer drive shaft 5 passes and through which coolant flows. The multiple radial oil outlet holes 111 communicate with the central hole 112. An inner spiral groove 113 is provided at the helical tooth end of the rotor shaft 11 near the radial oil outlet holes 111, allowing the rotor shaft 11 to form a spiral seal with the reducer drive shaft 5 via the inner spiral groove 113 and the coolant. An outer spiral groove 114 is provided at the end of the rotor shaft 11 (the end used to mount the position sensor), allowing the rotor shaft 11 to form a spiral seal with the junction box cover 4 via the outer spiral groove 114 and the coolant.
[0031] In some embodiments, the inner spiral groove 113 rotates counterclockwise, and the oil discharge direction of the spiral seal formed by the rotor shaft 11 through the inner spiral groove 113, coolant, and reducer drive shaft 5 is from right to left. The outer spiral groove 114 rotates counterclockwise, and the oil discharge direction of the spiral seal formed by the rotor shaft 11 through the outer spiral groove 114, coolant, and junction box cover 4 is from right to left (see...). Figure 3 , Figure 4 As an example, the inner spiral groove 113 has a rectangular cross-section, and the outer spiral groove 114 has a rectangular cross-section. Compared with sealing rings, spiral seals do not require additional structural accessories and have advantages such as simple structure, cost savings, and no related quality risks.
[0032] like Figure 2 , Figures 5 to 8 As shown, the coaxial electric drive system in this embodiment of the present invention includes: a housing 2, a stator assembly 6 fixed inside the housing 2, a rear end cover 3 connected to the housing 2, a junction box cover 4 connected to the rear end cover 3, and a rotor assembly 1 located inside the housing 2 whose rotor shaft 11 cooperates with the junction box cover 4 (see [reference]). Figure 1 The reducer drive shaft 5 passes through the junction box cover 4 and is coaxially mounted in the center hole 112 of the rotor shaft. There is a rotor oil passage between the reducer drive shaft 5 and the rotor shaft 11.
[0033] like Figure 2 , Figure 5 , Figure 6 As shown, the housing 2 has interconnected housing oil passages 21 and motor oil inlet passages 22. In some embodiments, the housing oil passage 21 is located at the upper left or upper right of the housing 2, and the angle α with the vertical plane satisfies: 0° < α ≤ 45°. As an example, the diameter of the housing oil passage 21 is 9 mm, the housing oil passage 21 is located at the upper right of the housing 2, and the angle α with the vertical plane is 45° (see [reference]). Figure 6 ).
[0034] like Figure 7As shown, the rear end cover 3 has a first oil passage 31, a second oil passage 32, and a third oil passage 33 connected in sequence. In some embodiments, the first oil passage 31 has a length of 15 mm and a diameter of 8 mm, and its centerline is parallel to the horizontal plane. The second oil passage 32 has a length of 85 mm and a diameter of 6 mm, and its centerline forms a 75° angle with the centerline of the first oil passage 31. The third oil passage 33 has a length of 47 mm and a diameter of 6 mm, and its centerline forms a 105° angle with the centerline of the second oil passage 32.
[0035] like Figure 8 As shown, the junction box cover 4 has a first oil passage 41, a second oil passage 42, and a bearing chamber 43 connected in sequence. In some embodiments, the first oil passage 41 has a length of 10 mm and a diameter of 6 mm, and its centerline is parallel to the horizontal plane. The second oil passage 42 has a length of 58 mm and a diameter of 6 mm, and its centerline forms an angle of 68° with the centerline of the first oil passage 41.
[0036] In some embodiments, the center lines of the housing oil passage 21, the end cap first oil passage 31, the end cap second oil passage 32, the end cap third oil passage 33, the box cover first oil passage 41, and the box cover second oil passage 42 are all located on the same plane.
[0037] The housing oil passage 21 is connected to the first oil passage 31 of the end cover, and the connection is sealed by the first sealing ring 7. The third oil passage 33 of the end cover is connected to the first oil passage 41 of the box cover, and the connection is sealed by the second sealing ring 8. The bearing chamber 43 of the box cover is connected to the rotor oil passage. The rotor shaft 11 forms a spiral seal with the junction box cover 4 through the outer spiral groove 114, the coolant, and the inner spiral groove 113, the coolant, and the reducer drive shaft 5.
[0038] like Figure 9 As shown, the oil circuit of the coaxial electric drive system is as follows: coolant (lubricating oil) enters the housing oil passage 21 of the housing 2 from the motor oil inlet 22, flows into the first oil passage 31 of the end cover through the housing oil passage 21, and then enters the first oil passage 41 of the housing cover through the second oil passage 32 and the third oil passage 33 of the end cover. It then flows into the bearing chamber 43 of the housing cover through the second oil passage 42 of the housing cover, and then enters the rotor oil passage formed by the reducer drive shaft 5 and the rotor shaft 11. Finally, the rotor assembly rotates and throws oil through the radial oil outlet 111 to the winding end of the stator assembly, thereby completing the cooling and lubrication of each component.
[0039] The above description is only a specific embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present utility model should be included within the protection scope of the present utility model.
Claims
1. A rotor assembly, comprising a rotor shaft (11), wherein the rotor shaft (11) has a plurality of radial oil outlet holes (111) and a central hole (112) through which a reducer drive shaft (5) passes and through which coolant flows, the plurality of radial oil outlet holes (111) communicating with the central hole (112); characterized in that: The rotor shaft (11) has an inner spiral groove (113) near the radial oil outlet at the helical tooth end. The rotor shaft (11) can form a spiral seal with the coolant and the reducer drive shaft (5) through the inner spiral groove (113). The rotor shaft (11) has an outer spiral groove (114) at the end. The rotor shaft (11) can form a spiral seal with the junction box cover (4) through the outer spiral groove (114) and the coolant.
2. The rotor assembly according to claim 1, characterized in that: The inner spiral groove (113) is left-handed, and the outer spiral groove (114) is left-handed.
3. A coaxial electric drive system, comprising: The housing (2), the stator assembly (6) fixed inside the housing (2), the rear end cover (3) connected to the housing (2), the junction box cover (4) connected to the rear end cover (3), the rotor assembly (1) located inside the housing (2) and whose rotor shaft cooperates with the junction box cover (4), and the reducer drive shaft (5) passing through the junction box cover (4) and coaxially assembled in the rotor shaft, the reducer drive shaft (5) having a rotor oil passage between the rotor shaft and the rotor shaft; characterized in that: the rotor assembly (1) adopts the rotor assembly as described in claim 1 or 2.
4. The coaxial electric drive system according to claim 3, characterized in that: The housing (2) is provided with an interconnected housing oil passage (21) and a motor oil inlet passage (22); the rear end cover (3) is provided with an end cover first oil passage (31), an end cover second oil passage (32), and an end cover third oil passage (33) connected in sequence; the junction box cover (4) is provided with a junction box first oil passage (41), a junction box second oil passage (42), and a junction box bearing chamber (43) connected in sequence. The housing oil passage (21) is connected to the end cover first oil passage (31) and sealed at the connection point by the first sealing ring (7); the end cover third oil passage (33) is connected to the box cover first oil passage (41) and sealed at the connection point by the second sealing ring (8); the box cover bearing chamber (43) is connected to the rotor oil passage, the rotor shaft (11) forms a spiral seal with the junction box cover (4) through the outer spiral groove (114), the coolant and the junction box cover (4), and the rotor shaft (11) forms a spiral seal with the reducer drive shaft (5) through the inner spiral groove (113) and the coolant.
5. The coaxial electric drive system according to claim 4, characterized in that: The shell oil passage (21) is located on the upper left or upper right of the shell (2), and the angle α between it and the vertical plane satisfies: 0°<α≤45°.
6. The coaxial electric drive system according to claim 4, characterized in that: The centerline of the first oil passage (31) of the end cap is parallel to the horizontal plane, the centerline of the second oil passage (32) of the end cap forms an angle of 75° with the centerline of the first oil passage (31) of the end cap, and the centerline of the third oil passage (33) of the end cap forms an angle of 105° with the centerline of the second oil passage (32) of the end cap.
7. The coaxial electric drive system according to claim 4, characterized in that: The centerline of the first oil passage (41) of the lid is parallel to the horizontal plane, and the angle between the centerline of the second oil passage (42) of the lid and the centerline of the first oil passage (41) of the lid is 68°.
8. The coaxial electric drive system according to claim 4, characterized in that: The length of the first oil passage (31) of the end cap is 15 mm, the length of the second oil passage (32) of the end cap is 85 mm, and the length of the third oil passage (33) of the end cap is 47 mm. The length of the first oil passage (41) of the box cover is 10mm, and the length of the second oil passage (42) of the box cover is 58mm.
9. The coaxial electric drive system according to any one of claims 4 to 8, characterized in that: The center lines of the shell oil passage (21), the end cap first oil passage (31), the end cap second oil passage (32), the end cap third oil passage (33), the box cover first oil passage (41), and the box cover second oil passage (42) are all located on the same plane.
10. A vehicle, characterized in that: Including the coaxial electric drive system as described in any one of claims 3 to 9.