Motor oil cooling system and motor oil cooling method

Abstract

The application discloses a motor oil cooling system and a motor oil cooling method. The motor oil cooling system comprises an oil cooling shell assembly, a stator assembly arranged in the oil cooling shell assembly, and a rotor assembly arranged in the stator assembly and rotationally connected with the stator assembly through a bearing. An end cover assembly is arranged at the right end of the oil cooling shell assembly. A shell oil passage is arranged between the oil cooling shell assembly, the stator assembly and the end cover assembly. A rotor oil passage is arranged in the rotor assembly. A shell oil inlet channel and a shell oil return channel are arranged on the oil cooling shell assembly and are communicated with the shell oil passage. A rotor oil inlet channel is arranged on the rotor assembly and is communicated with the rotor oil passage. The rotor oil passage is communicated with the shell oil return channel. The motor can be efficiently and sufficiently cooled by simultaneously cooling the stator core, the stator winding, the rotor core, the bearing and other heating parts, and the motor has better process performance and cost advantage.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of motor heat dissipation, and particularly relates to a motor oil cooling system and a motor oil cooling method. BACKGROUND

[0002] With the rapid development of new energy vehicles, it is becoming a general trend to pursue high efficiency, high power density and high speed of vehicle permanent magnet synchronous motors, and the consequent motor temperature rise challenge is becoming increasingly severe. Therefore, a more efficient cooling system is urgently needed to promptly remove the heat generated during motor operation, otherwise it is easy to cause the motor temperature to rise too high, which may affect the performance, and even cause the winding to burn out, the magnetic steel to demagnetize, the bearing to be damaged and other consequences, seriously affecting the service life of the motor.

[0003] Generally, three ways are commonly used to cool the motor, including air cooling system, water cooling system and oil cooling system. Due to the limitation of cooling methods and cooling efficiency, the first two methods are increasingly difficult to meet the heat dissipation needs of the motor. The current oil cooling system has the disadvantages of insufficient cooling, complex structure, high cost and the like.

[0004] Chinese patent CN206149098U discloses an oil-cooled motor and vehicle. The rotor oil path of the patent is realized through balance plate opening and rotor core opening, but only simple radial oil throwing, which cannot cool the bearing. Moreover, the shell oil path of the patent cannot cool the bearing. Chinese patent CN111181300A discloses an oil-cooled structure of a permanent magnet synchronous motor. The shell oil path of the patent is composed of upper and lower shells. The cooling oil has no fixed oil path after entering the shell, and many parallel branches are difficult to ensure the flow direction. The rotor oil path of the patent only has simple axial oil passage. The cooling oil directly enters the rotor core oil passage hole through the rotating shaft. The rotor core structure is complex. SUMMARY

[0005] In view of the defects of the prior art, the application provides a motor oil cooling system and a motor oil cooling method, which can simultaneously cool the stator core, stator winding, rotor core, bearing and other heat generating parts to fully cool the motor.

[0006] The technical scheme adopted by the application to solve the technical problems is:

[0007] The application discloses a motor oil cooling system, which comprises an oil cooling shell assembly, a stator assembly arranged in the oil cooling shell assembly and a rotor assembly arranged in the stator assembly and rotatably connected with the stator assembly through a bearing, wherein a right end of the oil cooling shell assembly is provided with an end cover assembly, a shell oil channel is arranged between the oil cooling shell assembly, the stator assembly and the end cover assembly, a rotor oil channel is arranged in the rotor assembly, an oil inlet channel of the shell and an oil return channel of the shell are arranged on the oil cooling shell assembly and are communicated with the shell oil channel, an oil inlet channel of the rotor is arranged on the rotor assembly and is communicated with the rotor oil channel, and the rotor oil channel is communicated with the oil return channel of the shell.

[0008] Further, the oil cooling shell assembly comprises a main shell, oil injection rings are respectively fixed on inner circular surfaces of left and right ends of the main shell, and a plurality of oil channel ribs are arranged on the inner circular surface of the main shell between the two oil injection rings; the stator assembly comprises a stator core with tooth grooves and a stator winding wound in the tooth grooves of the stator core and having left and right end portions, the stator core is arranged in the main shell and an outer circular surface thereof contacts the oil channel ribs and forms an interference fit, and the stator winding corresponds to the position of the oil injection ring on the corresponding side; the oil inlet channel of the shell is arranged at the left end of the main shell, the plurality of oil channel ribs, the outer circular surface of the stator core and the two oil injection rings surround an oil conveying channel which is communicated with the oil inlet channel of the shell, the oil injection ring is provided with an oil inlet port communicated with the oil conveying channel, and a plurality of oil outlet holes are arranged on the inner circular surface of the oil injection ring.

[0009] Further, the oil return channel of the shell is arranged on the outer circular surface of the main shell, the end cover assembly comprises a main end cover and a bearing steel insert arranged in the main end cover, the right bearing is arranged in the bearing steel insert, an oil collecting ring is arranged on the outer side surface of the bearing steel insert, an opening communicated with the oil collecting ring is further arranged on the bearing steel insert, and an oil return hole is arranged on the main end cover; the cooling oil in the left oil injection ring is used for being sprayed to the outer side of the left stator winding through the plurality of oil outlet holes on the corresponding side and directly flowing into the oil return channel of the shell; the cooling oil in the right oil injection ring is used for being sprayed to the outer side of the right stator winding through the plurality of oil outlet holes on the corresponding side, part of the cooling oil enters the oil collecting ring and flows into the surface and the inside of the right bearing through the opening, and the cooling oil flows into the oil return channel of the shell through the oil return hole.

[0010] Further, the axial channels formed by the key grooves, the welding grooves and the marking grooves on the outer circular surface of the stator core are blocked by oil-resistant silicone rubber; or a plurality of punched sheets for blocking the axial channels of the outer circular surface of the stator core are arranged at the right end of the stator core.

[0011] Further, the oil channel ribs are arranged along the axial direction of the main shell, so that the oil conveying channel forms a Z-shaped channel, and the surface of the oil channel rib is provided with an axial auxiliary rib.

[0012] Further, the oil injection ring is connected to the main shell through friction stir welding or argon arc welding.

[0013] Further, the oil outlet hole is an inclined hole.

[0014] Further, the rotor assembly comprises a hollow shaft, a rotor core corresponding to the position of the stator core is sleeved on the hollow shaft, balance plates are respectively fixedly sleeved on the left and right ends of the rotor core; the rotor oil inlet channel is formed in the hollow shaft, rotor oil outlet holes are respectively arranged at the positions of the two balance plates, oil passage assemblies are arranged on the two balance plates, the left oil passage assembly comprises an annular oil channel arranged on the right side surface of the left balance plate and communicating with the corresponding rotor oil outlet hole, an oil inlet groove corresponding to the rotor oil outlet hole is arranged at the inner edge of the annular oil channel, a plurality of rotor core oil inlet channels are outwardly extended from the right side surface of the left balance plate at the outer edge of the annular oil channel, a plurality of weight reduction holes communicating with the rotor core oil inlet channels are arranged on the rotor core, and a plurality of avoiding holes are further arranged on the left balance plate outside the annular oil channel; the cooling oil in the annular oil channel enters the weight reduction holes through the plurality of rotor core oil inlet channels and is thrown into the oil-cooled shell cavity through the plurality of avoiding holes to be thrown onto the bearing.

[0015] Further, an oil sealing plug is arranged at the right side of the balance plate in the hollow shaft.

[0016] Further, the number of the rotor core oil inlet channels and the avoiding holes on the left balance plate is the same and they are alternately distributed, and the positions of the plurality of rotor core oil inlet channels and the plurality of avoiding holes on the right balance plate one-to-one correspond.

[0017] Further, a plurality of oil throwing channels corresponding to the number of the rotor core oil inlet channels are further arranged on the right side surface of the left balance plate at the outer edge of the annular oil channel, the rotor core oil inlet channels, the avoiding holes and the oil throwing channels are alternately distributed, and the cooling oil in the annular oil channel is thrown into the inside of the stator winding through the plurality of oil throwing channels and flows into the shell oil return channel.

[0018] Further, the number of the iron core oil inlet channels on the left side is 2n, n is a positive integer, two first positioning key grooves and two second positioning key grooves are respectively arranged on the outer circular surface of the hollow shaft between the two balance plates, the first positioning key grooves and the second positioning key grooves are parallel to the axis of the hollow shaft, the horizontal length of the first positioning key grooves is equal to the horizontal distance between the two balance plates, the two second positioning key grooves are close to the right balance plate, the circumferential angle between the two first positioning key grooves is equal to the circumferential angle between the two second positioning key grooves and is 180°, the circumferential angle between the first positioning key grooves and the adjacent second positioning key grooves is 90° / n, the two balance plates are designed as the same part, and after the two balance plates are positioned through the two first positioning key grooves and the two second positioning key grooves when assembled with the hollow shaft, an angle deviation of 90° / n is formed between the two balance plates, so that the plurality of rotor oil inlet channels of the left balance plate correspond one by one to the plurality of avoiding holes of the right balance plate.

[0019] Further, the opposite sides of the two balance plates are further provided with oil guide fins or oil guide grooves, the cooling oil flowing out of the rotor core is used to flow to the bearing through the oil guide fins or the oil guide grooves; the oil throwing channel is a chute; the motor oil cooling system further comprises an external motor oil pump, a filter and a radiator, and the cooling oil in the shell oil return channel is used to return to the shell oil inlet channel and the rotor oil inlet channel to circulate again after passing through the external motor oil pump, the filter and the radiator in sequence.

[0020] A motor oil cooling method, which adopts the above motor oil cooling system to cool the motor, comprises the following cooling modes:

[0021] (1) The cooling oil enters the shell oil inlet channel to cool the stator core, the outer side of the stator winding and the right bearing of the stator assembly, and then enters the shell oil return channel;

[0022] (2) The cooling oil enters the rotor oil inlet channel to cool the rotor core, the inner side of the stator winding and the bearings on the left and right sides of the rotor assembly, and then enters the shell oil return channel.

[0023] Further, in the cooling mode (1), the cooling oil enters the main casing of the oil-cooled casing assembly from the casing oil inlet channel of the casing, and flows to the oil delivery channel to cool the stator core of the stator assembly; after flowing in the oil delivery channel for several rounds, the cooling oil enters the left oil injection ring and the right oil injection ring through the oil inlet on the left oil injection ring and the oil inlet on the right oil injection ring respectively; the cooling oil in the left oil injection ring is sprayed to the outside of the left end stator winding through the corresponding plurality of oil outlet holes, and directly flows into the casing oil return channel; the cooling oil in the right oil injection ring is sprayed to the outside of the right end stator winding through the corresponding plurality of oil outlet holes, and part of the cooling oil enters the oil collecting ring of the end cover assembly and flows into the right bearing surface and the inside through the opening of the bearing steel insert to cool the right bearing, and enters the casing oil return channel through the oil return hole of the end cover assembly.

[0024] Further, in the cooling mode (2), the cooling oil enters the hollow shaft of the rotor assembly from the rotor oil inlet channel at the same time, and enters the annular oil channel on the corresponding side balance plate through the corresponding rotor oil outlet hole and oil inlet groove respectively; the cooling oil in the annular oil channel enters the weight-reducing holes of the rotor core through the plurality of core oil inlet channels, and is thrown into the oil-cooled casing cavity through the plurality of avoiding holes on the balance plate, and then is thrown onto the bearings on the left and right sides to cool the bearings; the cooling oil in the annular oil channel is also thrown into the inside of the stator winding through the plurality of oil throwing channels to cool the stator winding; finally, the cooling oil flows into the casing oil return channel under the action of gravity.

[0025] Compared with the prior art, the motor oil cooling system has the following beneficial effects:

[0026] The motor oil cooling system comprises an oil-cooled casing assembly, a stator assembly arranged in the oil-cooled casing assembly, and a rotor assembly arranged in the stator assembly and rotationally connected to the stator assembly through bearings; an end cover assembly is arranged at the right end of the oil-cooled casing assembly; a casing oil circuit is arranged between the oil-cooled casing assembly, the stator assembly and the end cover assembly; a rotor oil circuit is arranged in the rotor assembly; a casing oil inlet channel and a casing oil return channel are arranged on the oil-cooled casing assembly and communicate with the casing oil circuit; a rotor oil inlet channel is arranged on the rotor assembly and communicates with the rotor oil circuit; and the rotor oil circuit communicates with the casing oil return channel; in this way, the cooling oil enters the casing oil circuit from the casing oil inlet channel to cool the stator core, the outside of the stator winding and the right bearing of the stator assembly; the cooling oil enters the rotor oil circuit from the rotor oil inlet channel at the same time to cool the rotor core, the inside of the stator winding and the bearings on the left and right sides of the rotor assembly; and then the cooling oil enters the casing oil return channel; therefore, the motor oil cooling system can sufficiently cool the main heat generating parts of the motor.

[0027] In the application, the oil-cooled shell assembly comprises a main shell, oil injection rings are respectively fixed on the inner circular surfaces of the left and right ends of the main shell, a plurality of oil channel ribs are arranged on the inner circular surface of the main shell between the two oil injection rings, the stator assembly comprises a stator core with tooth slots and a stator winding wound in the tooth slots of the stator core and having left and right ends, the stator core is arranged in the main shell and the outer circular surface thereof contacts the oil channel ribs and forms an interference fit, the stator winding corresponds to the positions of the oil injection rings on the corresponding side, an oil inlet channel of the shell is arranged at the left end of the main shell, the plurality of oil channel ribs, the outer circular surface of the stator core and the two oil injection rings form an oil delivery channel in communication with the oil inlet channel of the shell, the oil injection rings are provided with oil inlets in communication with the oil delivery channel, a plurality of oil outlets are arranged on the inner circular surface of the oil injection ring, an oil return channel of the shell is arranged on the outer circular surface of the main shell, the end cover assembly comprises a main end cover and a bearing steel insert arranged in the main end cover, a right bearing is arranged in the bearing steel insert, an oil collecting ring is arranged on the outer side surface of the bearing steel insert, an opening in communication with the oil collecting ring is further arranged on the bearing steel insert, and an oil return hole is arranged on the main end cover; in this way, the cooling oil enters the main shell from the oil inlet channel of the shell and flows to the oil delivery channel to cool the stator core, the cooling oil flows in the oil delivery channel for several turns, then enters the left and right oil injection rings through the oil inlets on the left and right oil injection rings respectively, the cooling oil in the left oil injection ring flows to the outside of the left end stator winding through the plurality of oil outlets on the corresponding side and directly flows into the oil return channel of the shell, and the cooling oil in the right oil injection ring flows to the outside of the right end stator winding through the plurality of oil outlets on the corresponding side, part of the cooling oil enters the oil collecting ring and flows into the surface and interior of the right bearing through the opening of the bearing steel insert to cool the right bearing, and then enters the oil return channel of the shell through the oil return hole of the main end cover.

[0028] In the application, the oil channel ribs are arranged in the axial direction of the main shell, so that the oil delivery channel forms a Z-shaped channel, the Z-shaped oil delivery channel formed by the inner circular surface of the main shell and the outer circular surface of the stator core has a passage area equivalent to that of a water-cooled shell, which ensures that the cooling oil flows through the stator core at a relatively fast speed, provides sufficient cooling oil flow and fully utilizes the high efficiency of direct cooling, so that the stator core is efficiently and sufficiently cooled; the oil channels of the left and right oil injection rings are connected in series with the oil delivery channel, so that all the cooling oil entering the oil inlet channel of the shell flows to the outside of the stator winding, ensuring that the stator winding has sufficient cooling oil flow; the oil channel ribs on the inner circular surface of the main shell are arranged in the axial direction, which greatly simplifies the casting process; the oil injection rings are connected to the inner circular surfaces of the corresponding side ends of the main shell by friction stir welding or argon arc welding, so that the left and right oil injection rings are separately machined from the main shell and connected by welding, thereby simplifying the machining process of the product, reducing the number of final parts and achieving the purposes of reducing production cost and management cost.

[0029] In the application, the axial passages formed by the key grooves, welding grooves and marking grooves on the outer circular surface of the stator core are blocked by oil-resistant silicone rubber to avoid the leakage of cooling oil in the Z-shaped passages; or, the right end of the stator core is provided with a plurality of punched sheets to block the axial passages of the outer circle of the stator core; the surface of the oil channel rib is provided with an axial auxiliary rib, which can increase the flow area of the cooling oil and improve the strength of the main shell; the oil outlet hole is an inclined hole, and the angles of the inclined hole in each direction are adjusted to achieve better oiling effect.

[0030] In the application, the rotor assembly includes a hollow shaft, a rotor core corresponding to the position of the stator core is sleeved on the hollow shaft, balance plates are fixedly sleeved on the left and right ends of the rotor core, a rotor oil inlet passage is formed in the inner cavity of the hollow shaft, rotor oil outlet holes are arranged at the positions of the two balance plates, and oil channel assemblies are arranged on the two balance plates. The left oil channel assembly includes an annular oil channel arranged on the right side surface of the left balance plate and communicating with the corresponding rotor oil outlet hole, an oil inlet groove corresponding to the corresponding rotor oil outlet hole is arranged at the inner edge of the left annular oil channel, a plurality of core oil inlet passages are arranged on the right side surface of the left balance plate and extend outward at the outer edge of the annular oil channel, a plurality of weight-reducing holes are arranged on the rotor core and communicate with the core oil inlet passages, a plurality of avoiding holes are arranged on the left balance plate outside the annular oil channel, the number of the core oil inlet passages and the avoiding holes on the left balance plate is the same and they are alternately distributed, the positions of the left core oil inlet passages and the right avoiding holes one-to-one correspond, a plurality of oil throwing passages with the same number of core oil inlet passages are arranged on the right side surface of the left balance plate and extend outward at the outer edge of the annular oil channel, and the core oil inlet passages, the avoiding holes and the oil throwing passages are alternately distributed. In this way, the cooling oil enters the hollow shaft from the rotor oil inlet passage, enters the annular oil channel on the corresponding side balance plate through the corresponding side rotor oil outlet hole and the oil inlet groove, enters the weight-reducing holes of the rotor core through the plurality of core oil inlet passages in the annular oil channel, is thrown into the oil-cooled shell cavity through the plurality of avoiding holes on the balance plate, and then is thrown onto the left and right bearings to cool the left and right bearings, the cooling oil in the annular oil channel is also thrown into the inside of the stator winding through the plurality of oil throwing passages to cool the stator winding, and finally the cooling oil flows into the shell oil return passage under the action of gravity.

[0031] In the application, the number of the iron core oil inlet channels on the left side is 2n, n is a positive integer, two first positioning key grooves and two second positioning key grooves are respectively arranged on the outer circular surface of the hollow shaft between the two balance plates, the first positioning key grooves and the second positioning key grooves are parallel to the axis of the hollow shaft, the horizontal length of the first positioning key grooves is equal to the horizontal distance between the two balance plates, the two second positioning key grooves are close to the right balance plate, the circumferential angle between the two first positioning key grooves is equal to the circumferential angle between the two second positioning key grooves and is 180°, the circumferential angle between the first positioning key groove and the adjacent second positioning key groove is 90° / n, the two balance plates are designed as the same part, after positioning through the two first positioning key grooves and the two second positioning key grooves when assembling with the hollow shaft, the two balance plates form an angle deviation of 90° / n, so that the plurality of rotor oil inlet channels of the left balance plate correspond to the plurality of avoiding holes of the right balance plate one by one; in this way, through the arrangement of the two pairs of first positioning key grooves and second positioning key grooves with special angles on the outer circular surface of the hollow shaft, the same balance plate can be used to realize multi-path rotor oil passage.

[0032] Since the oil groove on the surface of the balance plate, that is, the iron core oil inlet channel, cooperates with the rotor core end face to form an oil passage, the machining difficulty of the balance plate is reduced, and the axial space is also reduced; since the balance plates on the left and right sides adopt the same part, different oil passages are formed only by different assembly positioning, the number of parts is reduced, and the material cost is further reduced.

[0033] In the application, the opposite sides of the two balance plates are also provided with oil guide fins or oil guide grooves, so that the cooling oil flowing out from the rotor core can be guided to the bearing; the oil throwing channel is a chute, and the angles of the chute in each direction are adjusted to achieve better oil throwing effect. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 It is a front view schematic diagram of the motor oil cooling system in the application;

[0035] Figure 2 It is a three-dimensional structure schematic diagram of the oil cooling shell assembly;

[0036] Figure 3 It is a three-dimensional structure schematic diagram of the end cover assembly;

[0037] Figure 4 It is a three-dimensional structure schematic diagram of the main shell;

[0038] Figure 5 It is a three-dimensional structure schematic diagram of the oil injection ring;

[0039] Figure 6 It is a three-dimensional structure schematic diagram of the stator assembly;

[0040] Figure 7 This is a schematic diagram showing the flow of cooling oil in the casing oil circuit;

[0041] Figure 8 This is a three-dimensional structural diagram of the rotor assembly;

[0042] Figure 9 This is a schematic diagram of the three-dimensional structure of the hollow shaft;

[0043] Figure 10 This is a schematic diagram of the three-dimensional sectional structure of the hollow shaft;

[0044] Figure 11 This is a schematic diagram of the balance plate structure;

[0045] Figure 12 for Figure 11 A structural diagram from another direction;

[0046] Figure 13 This is a schematic diagram showing the flow of cooling oil in the rotor oil circuit.

[0047] The following are the annotations in the attached diagram: 1. Oil-cooled housing assembly; 2. Stator assembly; 3. End cover assembly; 4. Main housing; 5. Oil injection ring; 6. Housing oil inlet channel; 7. Oil duct rib; 8. Housing oil return channel; 9. Oil inlet; 10. Oil outlet; 11. Stator core; 12. Stator winding; 13. Main end cover; 14. Bearing steel insert; 15. Bearing; 16. Oil collection ring; 17. Oil return hole; 18. Hollow shaft; 19. Rotor core; 20. Balance plate; 21. Locking component; 22. Rotor oil inlet channel; 23. Oil sealing plug; 24. Rotor oil outlet; 25. Annular oil passage; 26. Oil inlet groove; 27. Core oil inlet channel; 28. Clearance hole; 29. ​​Oil slinger channel; 30. First positioning keyway; 31. Second positioning keyway. Detailed Implementation

[0048] like Figure 1 As shown, an oil cooling system for an electric motor includes an oil cooling housing assembly 1, a stator assembly 2 disposed within the oil cooling housing assembly 1, and a rotor assembly disposed within the stator assembly 2 and rotatably connected to the stator assembly 2 via a bearing 15. An end cover assembly 3 is provided at the right end of the oil cooling housing assembly 1. A housing oil passage is provided between the oil cooling housing assembly 1, the stator assembly 2, and the end cover assembly 3. A rotor oil passage is provided inside the rotor assembly. The oil cooling housing assembly 1 is provided with a housing oil inlet channel 6 and a housing oil return channel 8 that communicate with the housing oil passage. The rotor assembly is provided with a rotor oil inlet channel 22 that communicates with the rotor oil passage. The rotor oil passage communicates with the housing oil return channel 8.

[0049] Among them, such as Figure 2 , 4As shown in FIG. 5, the oil-cooled housing assembly 1 comprises a main housing 4, and two oil injection rings 5 are respectively fixed on the inner circular surface of the left and right ends of the main housing 4. A plurality of oil channel ribs 7 are arranged on the inner circular surface of the main housing 4 between the two oil injection rings 5. Figure 6 As shown in FIG. 6, the stator assembly 2 comprises a stator core 11 with tooth slots and a stator winding 12 with left and right ends wound in the tooth slots of the stator core 11. The stator core 11 is arranged in the main housing 4 and the outer circular surface thereof contacts the oil channel ribs 7 and forms an interference fit. The stator winding 12 corresponds to the position of the corresponding side oil injection ring 5. The housing oil inlet passage 6 is arranged at the left end of the main housing 4. The plurality of oil channel ribs 7, the outer circular surface of the stator core 11 and the two oil injection rings 5 form an oil delivery passage in communication with the housing oil inlet passage 6. The oil injection ring 5 is provided with an oil inlet 9 in communication with the oil delivery passage. A plurality of oil outlet holes 10 are arranged on the inner circular surface of the oil injection ring 5. The housing oil return passage 8 is arranged on the outer circular surface of the main housing 4. Figure 3 As shown in FIG. 7, the end cover assembly 3 comprises a main end cover 13 and a bearing steel insert 14 arranged in the main end cover 13. The right bearing 15 is arranged in the bearing steel insert 14. The bearing steel insert 14 is provided with an oil collecting ring 16 on the outer side surface thereof. The bearing steel insert 14 is further provided with an opening in communication with the oil collecting ring 16. The main end cover 13 is provided with an oil return hole 17. In this way, the cooling oil enters the main housing 4 from the housing oil inlet passage 6 and flows to the oil delivery passage to cool the stator core 11. After flowing in the oil delivery passage for several turns, the cooling oil enters the left oil injection ring 5 and the right oil injection ring 5 through the oil inlet 9 of the left oil injection ring 5 and the oil inlet 9 of the right oil injection ring 5, respectively. The cooling oil in the left oil injection ring 5 is sprayed to the outer side of the left stator winding 12 through the plurality of oil outlet holes 10 on the corresponding side, and directly flows into the housing oil return passage 8. The cooling oil in the right oil injection ring 5 is sprayed to the outer side of the right stator winding 12 through the plurality of oil outlet holes 10 on the corresponding side, and part of the cooling oil enters the oil collecting ring 16 and flows into the surface and interior of the right bearing 15 through the opening of the bearing steel insert 14 to cool the right bearing 15, and then enters the housing oil return passage 8 through the oil return hole 17 of the main end cover 13.

[0050] As shown in FIG. 8, the oil-cooled housing assembly 1 comprises a main housing 4, and two oil injection rings 5 are respectively fixed on the inner circular surface of the left and right ends of the main housing 4. A plurality of oil channel ribs 7 are arranged on the inner circular surface of the main housing 4 between the two oil injection rings 5. Figure 2 and 4As shown, the oil channel rib 7 is arranged along the axial direction of the main housing 4, forming a Z-shaped oil channel. Since the inner circular surface of the main housing 4 and the outer circular surface of the stator core 11 form a Z-shaped oil channel, its passage area is comparable to that of the water-cooled housing, ensuring that the cooling oil flows through the stator core 11 at a relatively fast flow rate. This provides sufficient cooling oil flow and makes full use of the high efficiency of direct cooling, resulting in efficient and sufficient cooling of the stator core 11. The axial arrangement of the oil channel rib 7 greatly simplifies the casting process. The surface of the oil channel rib 7 is provided with axial auxiliary ribs, which increases the flow area of ​​the cooling oil and improves the strength of the main housing 4. The oil spray ring 5 is connected to the inner circular surface of the corresponding side end of the main housing 4 by friction stir welding or argon arc welding. In this way, the oil spray rings 5 ​​on the left and right sides are processed separately from the main housing 4 and connected by welding, which simplifies the product processing process and reduces the number of final parts, thereby reducing production and management costs. The oil outlet 10 is an oblique hole, and by adjusting the angle of the oblique hole in each direction, a better oil spraying effect can be achieved.

[0051] The axial channels formed by the keyways, welding grooves and marking grooves on the outer circular surface of the stator core 11 are blocked by oil-resistant silicone rubber to prevent the leakage of cooling oil in the Z-shaped channels; or, the right end of the stator core 11 is provided with multiple laminations, which retain only the basic functional features such as stator slots and teeth, and are fixed to the rest of the core by adhesive bonding, thereby blocking the axial channels on the outer circle of the stator core 11.

[0052] Among them, such as Figures 8-12 As shown, the rotor assembly includes a hollow shaft 18, on which a rotor core 19, corresponding to the position of the stator core 11, is fitted. Balance plates 20 are fixedly fitted at both ends of the hollow shaft 18 and the rotor core 19. An oil inlet channel 22 is formed within the hollow shaft 18. An oil sealing plug 23 is provided on the right side of the balance plate 20 within the hollow shaft 18. Two rotor oil outlet holes 24 with a circumferential angle of 180° are provided on the left and right sides of the balance plate 20. Oil passage components are provided on both balance plates 20. Figure 8 , 11As shown in FIGS. 12, the left oil passage assembly includes an annular oil channel 25 arranged on the right side surface of the left balance plate 20 and communicated with the corresponding rotor oil outlet hole 24, two oil inlet grooves 26 corresponding to the corresponding rotor oil outlet hole 24 are arranged at the inner edge of the left annular oil channel 25, a plurality of iron core oil inlet channels 27 are arranged on the right side surface of the left balance plate 20 at the outer edge of the annular oil channel 25, a plurality of weight reduction holes are arranged on the rotor iron core 19 and communicated with the iron core oil inlet channel 27, a plurality of avoiding holes 28 are arranged on the left balance plate 20 outside the annular oil channel 25, the number of the iron core oil inlet channel 27 and the avoiding hole 28 on the left balance plate 20 is the same and alternately distributed, the positions of the left plurality of iron core oil inlet channels 27 and the right plurality of avoiding holes 28 correspond one by one, a plurality of oil throwing channels 29 corresponding to the number of the iron core oil inlet channel 27 are arranged on the right side surface of the left balance plate 20 at the outer edge of the annular oil channel 25, and the iron core oil inlet channel 27, the avoiding hole 28 and the oil throwing channel 29 are alternately distributed; in this way, the cooling oil enters the hollow shaft 18 from the rotor oil inlet channel 22, enters the annular oil channel 25 on the corresponding side balance plate 20 through the corresponding side rotor oil outlet hole 24 and the oil inlet groove 26, the cooling oil in the annular oil channel 25 enters the weight reduction hole of the rotor iron core 19 through the plurality of iron core oil inlet channels 27, and is thrown into the oil cooling shell cavity through the plurality of avoiding holes 28 on the balance plate 20, and then is thrown onto the left and right bearings 15 to cool the left and right bearings 15, the cooling oil in the annular oil channel 25 is also thrown into the inside of the stator winding 12 through the plurality of oil throwing channels 29 to cool the stator winding 12, and finally the cooling oil flows into the shell oil return channel 8 under the action of gravity.

[0053] In the embodiment, the number of the left iron core oil inlet channel 27 is 2n, n is a positive integer, two first positioning key grooves 30 and two second positioning key grooves 31 are arranged on the outer circular surface of the hollow shaft 18 between the two balance plates 20, the first positioning key groove 30 and the second positioning key groove 31 are parallel to the axis of the hollow shaft 18, the horizontal length of the first positioning key groove 30 is equal to the horizontal distance between the two balance plates 20, the two second positioning key grooves 31 are close to the right balance plate 20, the circumferential angle between the two first positioning key grooves 30 is equal to the circumferential angle between the two second positioning key grooves 31 and is 180°, the circumferential angle between the first positioning key groove 30 and the adjacent second positioning key groove 31 is 90° / n, the two balance plates 20 are designed as the same part, and after the two balance plates 20 are positioned through the two first positioning key grooves 30 and the two second positioning key grooves 31 when assembled with the hollow shaft 18, the two balance plates 20 form an angle deviation of 90° / n with each other, so that the plurality of rotor oil inlet channels 22 of the left balance plate 20 correspond to the plurality of avoiding holes 28 of the right balance plate 20 one by one; in this way, through the arrangement of the two pairs of first positioning key grooves 30 and second positioning key grooves 31 with special angles on the outer circular surface of the hollow shaft 18, the same balance plate 20 can be used to realize multi-path rotor oil passage.

[0054] The opposite sides of the two balance plates 20 are further provided with oil guide wings or oil guide grooves, and the cooling oil flowing out of the rotor core 19 is used to flow to the bearing 15 through the oil guide wings or oil guide grooves; the oil throwing channel 29 is a slanted groove, and the throwing oil effect is achieved by adjusting the angles of the slanted groove in different directions; the motor oil cooling system further comprises an external motor oil pump, a filter and a radiator, and the cooling oil in the shell oil return channel 8 is used to flow back to the shell oil inlet channel 6 and the rotor oil inlet channel 22 after passing through the external motor oil pump, the filter and the radiator in sequence to be recycled again.

[0055] As shown in Figure 9 , the hollow shaft 18 is provided with a protrusion 32 at the left end of the left balance plate 20, and the protrusion 32 is matched with the rotor core 19 to clamp the left balance plate 20; the hollow shaft 18 is provided with a locking piece 21 at the right end of the right balance plate 20 for locking the right balance plate 20, as shown in Figure 1 .

[0056] A motor oil cooling method, which adopts the above motor oil cooling system to cool the motor, comprises the following cooling modes:

[0057] (1) As shown in Figure 7 , the cooling oil enters the shell oil passage from the shell oil inlet channel 6 to cool the stator core 11, the outer side of the stator winding 12 and the right bearing 15 of the stator assembly 2; specifically, the cooling oil enters the main shell 4 of the oil cooling shell assembly 1 from the shell oil inlet channel 6 and flows to the oil conveying channel to cool the stator core 11; after flowing in the oil conveying channel for several turns, the cooling oil enters the left oil injection ring 5 and the right oil injection ring 5 through the oil inlet 9 on the left oil injection ring 5 and the oil inlet 9 on the right oil injection ring 5 respectively; the cooling oil in the left oil injection ring 5 is sprayed to the outer side of the left end stator winding 12 through the corresponding multiple oil outlet holes 10 and directly flows into the shell oil return channel 8; the cooling oil in the right oil injection ring 5 is sprayed to the outer side of the right end stator winding 12 through the corresponding multiple oil outlet holes 10, and part of the cooling oil enters the oil collecting ring 16 of the end cover assembly 3 and flows into the surface and interior of the right bearing 15 through the opening of the bearing steel insert 14 to cool the right bearing 15, and then enters the shell oil return channel 8 through the oil return hole 17 of the end cover assembly 3;

[0058] (2) As shown in Figure 13As shown, the cooling oil enters the rotor oil passage from the rotor oil inlet channel 22 at the same time to cool the rotor core 19 of the rotor assembly, the inside of the stator winding 12 and the bearings 15 on the left and right sides, specifically, the cooling oil enters the hollow shaft 18 of the rotor assembly from the rotor oil inlet channel 22 at the same time, and enters the annular oil channel 25 on the corresponding side balance plate 20 through the corresponding side rotor oil outlet hole 24 and oil inlet groove 26 respectively, the cooling oil in the annular oil channel 25 enters the weight-reducing hole of the rotor core 19 through a plurality of core oil inlet channels 27, and is thrown into the oil-cooled shell cavity through a plurality of avoiding holes 28 on the balance plate 20, and then is thrown onto the bearings 15 on the left and right sides to cool the bearings 15 on the left and right sides, the cooling oil in the annular oil channel 25 is also thrown into the inside of the stator winding 12 through a plurality of oil throwing channels 29 to cool the stator winding 12, and finally the cooling oil flows into the shell oil return channel 8 under the action of gravity.

[0059] The motor oil cooling system in the application is an oil cooling system of a vehicle-used permanent magnet synchronous driving motor.

[0060] Compared with the prior art, the application has only one main shell 4, the shell oil passage is surrounded by the oil channel rib 7 of the main shell 4 and the stator core 11, the oil passage flow direction is axial Z type, the two ends of the oil passage are sealed through the oil injection ring 5 welded together with the main shell 4, the process of the main shell 4 is good, the rotor oil passage of the application is realized by the complex groove of the balance plate 20 and the weight-reducing hole of the rotor core 19, contains the annular oil channel 25, which is used to distribute the cooling oil flow direction, the cooling oil enters the core oil inlet channel 27 and the radial oil throwing channel 29 through the annular oil channel 25 respectively, through the special position design of the first positioning key groove 30 and the second positioning key groove 31, the same balance plate 20 is used to realize the multi-path rotor oil passage.

[0061] In summary, the motor oil cooling system of the application can cool the stator core 11, the stator winding 12, the rotor core 19, the bearing 15 and other heating parts at the same time, so as to cool the motor efficiently and sufficiently, and has good process and cost advantages.

[0062] The above is only the preferred embodiment of the application, and it should be pointed out that for ordinary skilled persons in the technical field, some improvements and replacements can be made without departing from the technical principles of the application, and these improvements and replacements should also be regarded as the protection scope of the application.

Claims

1. An electric machine oil cooling system characterized by: The application relates to an oil-cooled shell assembly (1), a stator assembly (2) arranged in the oil-cooled shell assembly (1) and a rotor assembly arranged in the stator assembly (2) and rotatably connected with the stator assembly (2) through a bearing (15), wherein the right end of the oil-cooled shell assembly (1) is provided with an end cover assembly (3), the oil-cooled shell assembly (1), the stator assembly (2) and the end cover assembly (3) are provided with a shell oil path, the rotor assembly is provided with a rotor oil path, the oil-cooled shell assembly (1) is provided with a shell oil inlet channel (6) and a shell oil return channel (8) in communication with the shell oil path, the rotor assembly is provided with a rotor oil inlet channel (22) in communication with the rotor oil path, and the rotor oil path is in communication with the shell oil return channel (8). The oil-cooled shell assembly (1) comprises a main shell (4), the inner circular surface of the left and right ends of the main shell (4) is respectively sealed and fixed with an oil injection ring (5), and a plurality of oil channel ribs (7) are arranged on the inner circular surface of the main shell (4) between the two oil injection rings (5); the stator assembly (2) comprises a stator core (11) with a tooth slot and a stator winding (12) with left and right ends wound in the tooth slot of the stator core (11), the stator core (11) is arranged in the main shell (4) and the outer circular surface thereof contacts the oil channel ribs (7) and forms an interference fit, and the stator winding (12) corresponds to the position of the corresponding oil injection ring (5) on the same side; the shell oil inlet channel (6) is arranged at the left end of the main shell (4), the plurality of oil channel ribs (7), the outer circular surface of the stator core (11) and the two oil injection rings (5) surround an oil conveying channel in communication with the shell oil inlet channel (6), the oil injection ring (5) is provided with an oil inlet (9) in communication with the oil conveying channel, and the inner circular surface of the oil injection ring (5) is provided with a plurality of oil outlet holes (10). The rotor assembly comprises a hollow shaft (18) on which a rotor core (19) corresponding to the position of the stator core (11) is sleeved, and balance plates (20) are respectively fixedly sleeved on the left and right ends of the rotor core (19); the rotor oil inlet channel (22) is formed in the inner cavity of the hollow shaft (18), the hollow shaft (18) is respectively provided with a rotor oil outlet hole (24) at the positions of the two balance plates (20), and the two balance plates (20) are respectively provided with an oil way assembly; the left oil way assembly comprises an annular oil channel (25) arranged on the right side surface of the left balance plate (20) and communicating with the corresponding rotor oil outlet hole (24), an oil inlet groove (26) corresponding to the corresponding rotor oil outlet hole (24) is arranged at the inner edge of the left annular oil channel (25), and a plurality of core oil inlet channels (27) are outwardly extended at the outer edge of the annular oil channel (25) on the right side surface of the left balance plate (20); a plurality of weight-reducing holes communicating with the core oil inlet channels (27) are arranged on the rotor core (19), and a plurality of avoiding holes (28) are further arranged on the outer side of the annular oil channel (25) of the left balance plate (20); the cooling oil in the annular oil channel (25) enters the weight-reducing holes through the plurality of core oil inlet channels (27) and is thrown into the oil-cooled shell cavity through the plurality of avoiding holes (28) to be thrown onto the bearing (15).

2. The motor oil cooling system of claim 1, wherein: The shell oil return channel (8) is arranged on the outer circular surface of the main shell (4), the end cover assembly (3) comprises a main end cover (13) and a bearing steel insert (14) arranged in the main end cover (13), the right bearing (15) is arranged in the bearing steel insert (14), an oil collecting ring (16) is arranged on the outer side surface of the bearing steel insert (14), the bearing steel insert (14) is further provided with an opening communicating with the oil collecting ring (16), and the main end cover (13) is provided with an oil return hole (17); the cooling oil in the left oil injection ring (5) is used for being sprayed to the outer side of the left stator winding (12) through the plurality of oil outlet holes (10) on the corresponding side and directly flowing into the shell oil return channel (8); the cooling oil in the right oil injection ring (5) is used for being sprayed to the outer side of the right stator winding (12) through the plurality of oil outlet holes (10) on the corresponding side, part of the cooling oil enters the oil collecting ring (16) and flows into the surface and the inside of the right bearing (15) through the opening, and then flows into the shell oil return channel (8) through the oil return hole (17).

3. The motor oil cooling system of claim 1, wherein: The axial channels formed by the key grooves, welding grooves and marking grooves on the outer circular surface of the stator core (11) are blocked by oil-resistant silicone rubber; or the right end of the stator core (11) is provided with a plurality of punching sheets for blocking the axial channels of the outer circular surface of the stator core (11).

4. The motor oil cooling system of claim 1, wherein: The oil channel ribs (7) are arranged in the axial direction of the main shell (4), so that the oil conveying channel forms a Z-shaped channel, and the surface of the oil channel rib (7) is provided with an axial auxiliary rib.

5. The motor oil cooling system of claim 1, wherein: The oil outlet hole (10) is an inclined hole.

6. The motor oil cooling system of claim 1, wherein: The hollow shaft (18) is provided with an oil sealing plug (23) at the right side of the balance plate (20).

7. The motor oil cooling system of claim 1, wherein: The left balance plate (20) is provided with iron core oil inlet channels (27) and avoidance holes (28) which are alternately distributed and have the same number, and the positions of the left plurality of iron core oil inlet channels (27) and the right plurality of avoidance holes (28) correspond one by one.

8. An electric machine oil cooling system as claimed in claim 7, characterized in that: The left balance plate (20) is further provided with a plurality of oil throwing channels (29) at the outer edge of the annular oil channel (25) on the right side, and the iron core oil inlet channels (27), avoidance holes (28) and oil throwing channels (29) are alternately distributed, and the cooling oil in the annular oil channel (25) is used to be thrown into the inside of the stator winding (12) through the plurality of oil throwing channels (29) and flow into the shell oil return channel (8).

9. An electric machine oil cooling system as claimed in claim 8, characterized in that: The number of the left iron core oil inlet channels (27) is 2n, n is a positive integer, and the hollow shaft (18) is provided with two first positioning key grooves (30) and two second positioning key grooves (31) between the two balance plates (20), the first positioning key grooves (30) and the second positioning key grooves (31) are parallel to the axis of the hollow shaft (18), the horizontal length of the first positioning key grooves (30) is equal to the horizontal distance between the two balance plates (20), the two second positioning key grooves (31) are close to the right balance plate (20), the circumferential angle between the two first positioning key grooves (30) is equal to the circumferential angle between the two second positioning key grooves (31) and is 180°, the circumferential angle between the first positioning key grooves (30) and the adjacent second positioning key grooves (31) is 90° / n, the two balance plates (20) are designed as the same part, and after the two balance plates (20) are positioned through the two first positioning key grooves (30) and the two second positioning key grooves (31) when assembled with the hollow shaft (18), an angle deviation of 90° / n is formed between the two balance plates (20), so that the plurality of rotor oil inlet channels (22) of the left balance plate (20) correspond one by one to the plurality of avoidance holes (28) of the right balance plate (20).

10. The motor oil cooling system of claim 8, wherein: The opposite sides of the two balance plates (20) are further provided with oil guide fins or oil guide grooves, the cooling oil flowing out of the rotor core (19) is used to flow to the bearing (15) through the oil guide fins or oil guide grooves; the oil throwing channel (29) is an inclined groove; the motor oil cooling system further comprises an external motor oil pump, a filter and a radiator, and the cooling oil in the shell oil return channel (8) is used to return to the shell oil inlet channel (6) and the rotor oil inlet channel (22) after passing through the external motor oil pump, the filter and the radiator in sequence to circulate again.

11. A method of motor oil cooling, using the motor oil cooling system according to any one of claims 1-10, characterized in that The cooling mode comprises the following steps: (1) the cooling oil enters the shell oil channel from the shell oil inlet channel (6) to cool the outside and right side of the stator core (11) and the stator winding (12) of the stator assembly (2), and then the cooling oil enters the shell oil return channel (8); (2), cooling oil enters the rotor oil passage from the rotor oil inlet passage (22) at the same time to cool the rotor core (19) of the rotor assembly, the inside of the stator winding (12) and the bearings (15) on the left and right sides, and then the cooling oil enters the housing oil return passage (8).

12. The method of claim 11, wherein, In cooling mode (1): cooling oil enters the main housing (4) of the oil-cooled housing assembly (1) from the housing oil inlet passage (6), and flows to the oil delivery passage to cool the stator core (11) of the stator assembly (2); After flowing in the oil delivery passage for several turns, the cooling oil enters the left oil injection ring (5) and the right oil injection ring (5) through the oil inlet (9) on the left oil injection ring (5) and the oil inlet (9) on the right oil injection ring (5) respectively, the cooling oil in the left oil injection ring (5) is sprayed to the outside of the left end stator winding (12) through a plurality of oil outlet holes (10) on the corresponding side, and directly flows into the housing oil return passage (8), the cooling oil in the right oil injection ring (5) is sprayed to the outside of the right end stator winding (12) through a plurality of oil outlet holes (10) on the corresponding side, and part of the cooling oil enters the oil collecting ring (16) of the end cover assembly (3) and flows into the surface and interior of the right bearing (15) through the opening of the bearing steel insert (14) to cool the right bearing (15), and enters the housing oil return passage (8) through the oil return hole (17) of the end cover assembly (3).

13. The method of claim 11, wherein the motor oil is cooled by a cooling system. In cooling mode (2): cooling oil enters the hollow shaft (18) of the rotor assembly from the rotor oil inlet passage (22) at the same time, and enters the annular oil channel (25) on the corresponding side balance plate (20) through the corresponding side rotor oil outlet hole (24) and oil inlet groove (26) respectively, the cooling oil in the annular oil channel (25) enters the weight-reducing hole of the rotor core (19) through a plurality of core oil inlet passages (27), and is thrown into the oil-cooled housing cavity through a plurality of avoidance holes (28) on the balance plate (20), and then is thrown onto the bearings (15) on the left and right sides to cool the bearings (15) on the left and right sides, the cooling oil in the annular oil channel (25) is also thrown into the inside of the stator winding (12) through a plurality of oil throwing passages (29) to cool the stator winding (12), and finally the cooling oil flows into the housing oil return passage (8) under the action of gravity.

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