Coaxial electric drive axle and vehicle

Abstract

The invention relates to a coaxial electric drive axle which comprises a left drive half shaft, a right drive half shaft, a power shell, a motor stator, a motor rotor, a motor shaft, an intermediate shaft, a support and a differential mechanism. A first chamber and a second chamber are arranged in the power shell; the motor stator and the bracket are respectively fixed in the first chamber and the second chamber; the left end of the motor shaft is supported on the power shell, the motor rotor is fixed on the left section of the motor shaft, and the right end of the motor shaft is supported on the bracket; the differential mechanism is located in the second cavity. The right end of the left driving half shaft penetrates through the motor shaft and is connected with the differential mechanism, and the left end of the right driving half shaft extends into the second cavity and is connected with the differential mechanism. The invention further provides a vehicle. According to the electric drive axle, the structure is compact, the performance is improved, the number of parts is reduced, and the reliability and the NVH performance of the electric drive axle are enhanced.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and more specifically to a coaxial electric drive axle and a vehicle. Background Technology

[0002] Some vehicles are equipped with an electric drive axle, which transmits power from the electric motor to the wheels, enabling the vehicle to move. An electric drive axle typically consists of a motor, a reducer, a differential, and half-shafts. The motor provides the power source; the reducer lowers the rotational speed and increases torque to meet the vehicle's driving needs; and the differential distributes driving force between the left and right wheels, ensuring smooth cornering. When the driver depresses the accelerator pedal, the vehicle's battery supplies power to the motor, which then transmits power through the reducer to the differential and half-shafts, ultimately driving the wheels.

[0003] The existing electric drive axle may have the following technical problems: Some electric drive axles use a parallel shaft offset output arrangement, with the motor shaft parallel to the output shaft, which occupies a lot of space and is not conducive to the overall vehicle layout.

[0004] Some electric drive axles use water-cooled motors, which have low power density and volume density. Some electric drive axles use a split structure for the motor, reducer, and axle housing. The motor, reducer, and axle housing are relatively independent, and the motor shaft and reducer input shaft are separate shafts. This results in low integration, a large number of parts, high cost, and poor NVH performance.

[0005] In some electric drive axles that use a coaxial design, the high-speed pinion is located outside the two bearings of the motor, resulting in a cantilevered state. This leads to unreasonable stress on the high-speed pinion and bearings, increasing the risk of NVH problems.

[0006] Some electric drive axles also have the problem of conflict between the size of the motor shaft center hole and the size of the high-speed gear, resulting in a low speed ratio of the reducer (mostly below 11), which leads to low output torque at the wheel end (mostly below 5000Nm) or the inability to reduce the motor torque (mostly around 400Nm). Electric drive axles suffer from performance limitations and high costs. Summary of the Invention

[0007] The purpose of this invention is to provide a coaxial electric drive axle and vehicle to alleviate or eliminate at least one of the aforementioned technical problems.

[0008] The present invention discloses a coaxial electric drive axle, comprising a left drive half-shaft, a right drive half-shaft, and a powertrain; the powertrain comprises a power housing, a motor stator, a motor rotor, a motor shaft, a first-stage drive gear, a first-stage driven gear, a second-stage drive gear, a second-stage driven gear, an intermediate shaft, a bracket, and a differential; the power housing contains a first chamber and a second chamber located to the right of the first chamber, the motor stator is fixedly installed in the first chamber, and the bracket is fixedly installed in the second chamber; The left section of the motor shaft is located in the first chamber, and the left end of the motor shaft is rotatably supported on the power housing. The motor rotor is fixedly installed on the left section of the motor shaft and the motor rotor cooperates with the motor stator. The right section of the motor shaft is located in the second chamber, and the first-stage drive gear is fixed on the right section of the motor shaft. The right end of the motor shaft is rotatably supported on the bracket. The differential is located in the second chamber. The left end of the differential housing is rotatably supported on the bracket, and the right end of the differential housing is rotatably supported on the power housing. The secondary driven gear is fixed on the differential housing. The intermediate shaft is located in the second chamber. The left and right ends of the intermediate shaft are rotatably supported on the power housing. The first-stage driven gear and the second-stage driving gear are fixed on the intermediate shaft. The first-stage driven gear meshes with the first-stage driving gear, and the second-stage driven gear meshes with the second-stage driving gear. The motor shaft is a hollow shaft. The right end of the left drive half shaft passes through the motor shaft and is connected to the left half shaft gear of the differential. The left end of the right drive half shaft extends into the second chamber and is connected to the right half shaft gear of the differential. The left drive half shaft, the motor shaft, the differential, and the right drive half shaft are coaxially arranged. The central axis of the intermediate shaft is parallel to the central axis of the motor shaft.

[0009] Optionally, the primary drive gear is integrally formed with the motor shaft.

[0010] Optionally, the power housing includes an end cover, a motor housing, and a reducer housing that are fixedly connected from left to right. The end cover and the motor housing form a first chamber, and the motor housing and the reducer housing form a second chamber.

[0011] Optionally, the motor housing is provided with a partition that separates the first chamber and the second chamber from each other.

[0012] Optionally, the intermediate shaft is a hollow shaft.

[0013] Optionally, it also includes a first bearing, a second bearing, a third bearing, a fourth bearing, a fifth bearing, and a sixth bearing. The motor shaft is connected to the power housing via the first bearing, the right end of the motor shaft is connected to the bracket via the second bearing, the left end of the differential housing is connected to the bracket via the third bearing, the right end of the differential housing is connected to the power housing via the fourth bearing, the left end of the intermediate shaft is connected to the power housing via the fifth bearing, and the right end of the intermediate shaft is connected to the power housing via the sixth bearing.

[0014] Optionally, a cooling and lubrication system is also included, comprising an electronic oil pump, an oil filter, an oil cooler, a left injection ring, and a right injection ring. The electronic oil pump, the oil filter, and the oil cooler are all fixedly mounted on the power housing. The electronic oil pump, the oil filter, and the oil cooler are connected sequentially via connecting oil passages. An oil extraction port is provided at the bottom of the second chamber. The electronic oil pump draws lubricating oil from the second chamber through the oil extraction port. The lubricating oil output by the electronic oil pump enters the oil filter. The lubricating oil filtered by the oil filter is delivered to the oil cooler. An oil delivery passage is provided in the power housing. The lubricating oil output by the oil cooler is delivered through the oil delivery passage to the left injection ring, the right injection ring, the first bearing, the second bearing, the third bearing, the fourth bearing, the fifth bearing, the sixth bearing, and the differential. The left injection ring and the right injection ring are both located in the first chamber. The left injection ring is located on the left side of the motor stator, and the right injection ring is located on the right side of the motor stator.

[0015] Optionally, the intermediate shaft is a hollow shaft, and the oil supply passage includes an oil inlet chamber, an oil injector, a first oil passage, a second oil passage, a third oil passage, and a fourth oil passage. The oil inlet chamber is located on the left side wall of the second chamber. The oil injector has an axial injection port and a radial injection port. The axial injection port is used to spray oil into the center hole of the intermediate shaft to lubricate the sixth bearing, and the radial injection port is used to spray oil into the oil inlet chamber. The oil inlet chamber provides lubricating oil to the fifth bearing. The first oil passage is located inside the shell wall of the power housing. One end of the first oil passage communicates with the oil inlet chamber, and the other end of the first oil passage has a connecting port that supplies lubricating oil to the left injection ring. The second oil passage is located inside the shell wall of the power housing. One end of the second oil passage is connected to the first oil passage, and the other end of the second oil passage extends to the first bearing to supply lubricating oil to the first bearing. The third oil passage is disposed between the power housing and the motor stator. The left end of the third oil passage is connected to the first oil passage through a connecting port, and the right end of the third oil passage extends to the right oil injection ring to supply lubricating oil to the right oil injection ring. The fourth oil passage is disposed inside the shell wall of the power housing. One end of the fourth oil passage is connected to the right oil injection ring. The fourth oil passage is provided with a first oil port, a second oil port, and a third oil port. The first oil port is used to supply lubricating oil to the second and third bearings, the second oil port is used to supply lubricating oil to the differential, and the third oil port is used to supply lubricating oil to the fourth bearing.

[0016] Optionally, the oil extraction port is located on the left side wall of the second chamber, and a baffle is provided to the right of the oil extraction port.

[0017] The present invention also proposes a vehicle comprising the coaxial electric drive axle described in any of the preceding claims.

[0018] This invention employs a coaxial design, a high-efficiency cooling and lubrication system, and a deeply integrated solution, achieving a compact structure, improved performance, and reduced number of parts for the electric drive axle, while also enhancing the reliability and NVH performance of the electric drive axle. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the coaxial electric drive bridge described in some embodiments; Figure 2 This is a cross-sectional view of the coaxial electric drive bridge described in some embodiments; Figure 3 for Figure 2 A magnified view of a portion of the view; Figure 4 This is one of the structural schematic diagrams of some components of the coaxial electric drive bridge described in some embodiments; Figure 5This is the second schematic diagram of the structure of some components of the coaxial electric drive bridge described in some embodiments; Figure 6 This is one of the schematic diagrams of the oil passages for the coaxial electric drive axle described in some embodiments; Figure 7 This is the second schematic diagram of the oil passage of the coaxial electric drive axle described in some embodiments.

[0020] In the diagram, 1—left drive half-shaft, 2—left axle tube, 3—left axle tube flange, 4—end cover, 5—motor housing, 6—reducer housing, 7—right axle tube flange, 8—right axle tube, 9—right drive half-shaft, 10—motor stator, 11—motor rotor, 12—motor shaft, 13—first-stage drive gear, 14—first bearing, 15—second bearing, 16—intermediate shaft, 17—first-stage driven gear, 18—second-stage drive gear, 19—fifth bearing, 20—sixth bearing, 21—second-stage driven gear, 22—differential, 23— Support bracket, 24—Third bearing, 25—Fourth bearing, 26—Seventh bearing, 27—Oil pump, 28—Oil filter, 29—Oil cooler, 30—Injector nozzle, 31—Oil baffle, 32—Wave spring, 33—Bearing groove, 34—Oil inlet chamber, 35—First oil passage, 36—Second oil passage, 37—Connecting port, 38—Third oil passage, 39—Left injection ring, 40—Right injection ring, 41—First sub-oil passage, 42—Second sub-oil passage, 43—First oil port, 44—Second oil port, 45—Third oil port, 46—Fifth oil passage. Detailed Implementation

[0021] The embodiments of the present invention will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention and not for limiting the scope of protection of the present invention.

[0022] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0023] like Figures 1 to 7The diagram shows a coaxial electric drive axle, comprising a left drive half-shaft 1, a right drive half-shaft 9, and a powertrain. The powertrain includes a power housing, a motor stator 10, a motor rotor 11, a motor shaft 12, a first-stage drive gear 13, a first-stage driven gear 17, a second-stage drive gear 18, a second-stage driven gear 21, an intermediate shaft 16, a bracket 23, and a differential 22. The power housing contains a first chamber and a second chamber located to the right of the first chamber. The motor stator 10 is fixedly installed in the first chamber, and the bracket 23 is fixedly installed in the second chamber. The left section of the motor shaft 12 is located in the first chamber, and the left end of the motor shaft 12 is rotatably supported on the power housing. The motor rotor 11 is fixedly installed on the left section of the motor shaft 12 and engages with the motor stator 10. The right section of the motor shaft 12 is located in the second chamber, and the first-stage drive gear 13 is fixed on the right section of the motor shaft 12. The right end of the motor shaft 12 is rotatably supported on the bracket 23. The differential 22 is positioned... Within the second chamber, the left end of the differential 22 housing is rotatably supported on the bracket 23, and the right end of the differential 22 housing is rotatably supported on the power housing. The secondary driven gear 21 is fixed to the differential 22 housing. The intermediate shaft 16 is located within the second chamber, with its left and right ends rotatably supported on the power housing. The primary driven gear 17 and the secondary driving gear 18 are fixed to the intermediate shaft 16. The primary driven gear 17 and the primary driving gear 18... Gear 13 meshes with each other, and the secondary driven gear 21 meshes with the secondary driving gear 18. The motor shaft 12 is a hollow shaft. The right end of the left drive half shaft 1 passes through the motor shaft 12 and is connected to the left half shaft gear of the differential 22. The left end of the right drive half shaft 9 extends into the second chamber and is connected to the right half shaft gear of the differential 22. The left drive half shaft 1, motor shaft 12, differential 22, and right drive half shaft 9 are coaxially arranged. The central axis of the intermediate shaft 16 is parallel to the central axis of the motor shaft 12.

[0024] In some embodiments, the primary drive gear 13 is integrally formed with the motor shaft 12.

[0025] In some embodiments, the power housing includes an end cap 4, a motor housing 5, and a reducer housing 6, which are fixedly connected from left to right. The end cap 4 and the motor housing 5 form a first chamber, and the motor housing 5 and the reducer housing 6 form a second chamber.

[0026] In some embodiments, the motor housing 5 is provided with a partition that separates the first chamber and the second chamber from each other.

[0027] In some embodiments, the intermediate shaft 16 is a hollow shaft.

[0028] In some embodiments, the coaxial electric drive axle further includes a first bearing 14, a second bearing 15, a third bearing 24, a fourth bearing 25, a fifth bearing 19, and a sixth bearing 20. The motor shaft 12 is connected to the power housing via the first bearing 14. The right end of the motor shaft 12 is connected to the bracket 23 via the second bearing 15. The left end of the differential 22 housing is connected to the bracket 23 via the third bearing 24. The right end of the differential 22 housing is connected to the power housing via the fourth bearing 25. The left end of the intermediate shaft 16 is connected to the power housing via the fifth bearing 19. The right end of the intermediate shaft 16 is connected to the power housing via the sixth bearing 20.

[0029] As a specific example, the coaxial electric drive axle comprises the following main components: left axle tube 2, left drive half shaft 1, seventh bearing 26, oil seal, end cover 4, motor housing 5, motor stator 10, motor rotor 11, motor shaft 12, first bearing 14, second bearing 15, bracket 23, reducer housing 6, second driven gear 21, differential 22, differential lock, third bearing 24, fourth bearing 25, right drive half shaft 9, right axle tube 8, fifth bearing 19, sixth bearing 20, intermediate shaft 16, oil baffle 31, fuel injector 30, electronic oil pump 27, oil filter 28, oil cooler 29, left fuel injection ring 39, and right fuel injection ring 40. The coaxial electric drive axle adopts a parallel shaft coaxial output scheme; the center distance of the first-stage gear is the same as that of the second-stage gear, so that the output shaft is concentric with the motor shaft 12; the motor shaft 12 meshes with the large gear on the intermediate shaft 16 to achieve first-stage reduction; the small gear on the intermediate shaft 16 meshes with the second-stage driven gear 21 to achieve second-stage reduction; the second-stage driven gear 21 is connected to the differential 22 to achieve torque output of the left and right half shafts; The left drive half-shaft 1 is supported on the left axle tube welded assembly by the seventh bearing 26. The left axle tube welded assembly is welded from the left axle tube 2 and the left axle tube flange 3. The left oil seal is installed on the left axle tube welded assembly and seals with the journal of the left drive half-shaft 1. The left drive half-shaft 1 passes through the motor shaft 12 and is connected to the differential 22. The right drive half-shaft 9 is connected to the differential 22. The right axle tube welded assembly is welded from the right axle tube 8 and the right axle tube flange 7. An oil seal is provided on the reducer housing 6 to seal with the journal of the right drive half-shaft 9. The left bridge pipe flange 3 has its own flange structure and is connected to the end cover 4 by bolts; the seventh bearing 26 and oil seal are installed inside the left bridge pipe welded assembly; the end cover 4 is fixed to the motor housing 5 by bolts; the motor housing 5 is fixed to the reducer housing 6 by bolts; the bracket 23 is fixed to the reducer housing 6; the right bridge pipe flange 7 has its own flange and is connected to the reducer housing 6 by bolts; the motor stator 10 is fixed to the motor housing 5 by bolts; the motor rotor 11 is fixed to the motor shaft 12, and the first bearing 14 and the second bearing 15 are set at both ends of the motor shaft 12. The left bearing is fixed to the end cover 4 by a pressure plate, and the right bearing is fixed to the end cover 4 by a pressure plate. The side bearing is fixed on the bracket 23; a wave spring 32 is installed between the right bearing of the motor and the motor shaft 12 to apply bearing preload; the left and right sides of the intermediate shaft 16 are connected to the motor housing 5 and the reducer housing 6 respectively through the fifth bearing 19 and the sixth bearing 20; the secondary driven gear 21 is fixed on the differential 22, the differential 22 is equipped with a differential lock, and the left and right ends of the differential 22 are connected to the bracket 23 and the reducer housing 6 respectively through the third bearing 24 and the fourth bearing 25; a shaft grounding ring is installed between the left side of the gear of the motor shaft 12 and the right side of the motor rotor 11 to reduce shaft current and protect the life of the gear bearing.

[0030] In some embodiments, the coaxial electric drive axle further includes a cooling and lubrication system, which includes an electronic oil pump 27, an oil filter 28, an oil cooler 29, a left injection ring 39, and a right injection ring 40. The electronic oil pump 27, oil filter 28, and oil cooler 29 are all fixedly mounted on the power housing. The electronic oil pump 27, oil filter 28, and oil cooler 29 are connected sequentially through connecting oil passages. An oil suction port is provided at the bottom of the second chamber. The electronic oil pump 27 draws lubricating oil from the second chamber through the oil suction port. The lubricating oil output by the electronic oil pump 27 enters the oil filter 29 through the oil passage on the motor housing 5. 8. The lubricating oil filtered by the oil filter 28 is delivered to the oil cooler 29 through the oil passage on the motor housing 5. The power housing is provided with an oil supply passage. The lubricating oil output from the oil cooler 28 is delivered to the left injection ring 39, the right injection ring 40, the first bearing 14, the second bearing 15, the third bearing 24, the fourth bearing 25, the fifth bearing 19, the sixth bearing 20 and the differential 22 through the oil supply passage. The left injection ring 39 and the right injection ring 40 are both located in the first chamber. The left injection ring 39 is located on the left side of the motor stator 10 and the right injection ring 40 is located on the right side of the motor stator 10.

[0031] In some embodiments, the intermediate shaft 16 is a hollow shaft, and the oil supply channels include an oil inlet chamber 34, a first oil channel 35, a second oil channel 36, a third oil channel 38, and a fourth oil channel. The oil inlet chamber 34 is located on the left side wall of the second chamber. An oil nozzle 30 is provided at the inlet of the oil inlet chamber 34. The oil nozzle 30 has an axial spray port and a radial spray port. The axial spray port is used to spray oil into the center hole of the intermediate shaft 16 to lubricate the sixth bearing 20, and the radial spray port is used to spray oil into the oil inlet chamber 34. The lubricating oil sprayed from the axial spray port enters the center hole of the intermediate shaft 16 to lubricate the sixth bearing 20; the lubricating oil sprayed from the radial spray port enters the oil inlet chamber 34, which provides lubricating oil to the fifth bearing 19. The first oil channel 35 is located inside the shell wall of the power housing. One end of the first oil channel 35 communicates with the oil inlet chamber 34, and the other end of the first oil channel 35 is provided with a connecting port 37, which sprays oil onto the left-hand oil ring 3. 9. A second oil passage 36 is located inside the shell wall of the power housing. One end of the second oil passage 36 is connected to the first oil passage 35, and the other end of the second oil passage 36 extends to the first bearing 14 to supply lubricating oil to the first bearing 14. A third oil passage 38 is located between the power housing and the motor stator 10. The left end of the third oil passage 38 is connected to the first oil passage 35 through the connecting port 37, and the right end of the third oil passage 38 extends to the right oil injection ring 40 to supply lubricating oil to the right oil injection ring 40. A fourth oil passage is located inside the shell wall of the power housing. One end of the fourth oil passage is connected to the right end of the right oil injection ring 40. The fourth oil passage is provided with a first oil port 43, a second oil port 44, and a third oil port 45. The first oil port 43 is used to supply lubricating oil to the second bearing 15 and the third bearing 24. The second oil port 44 is used to supply lubricating oil to the differential 22. The third oil port 45 is used to supply lubricating oil to the fourth bearing 25.

[0032] In some embodiments, the oil extraction port is located on the left side wall of the second chamber, and a baffle is provided to the right of the oil extraction port.

[0033] As a specific example, the cooling and lubrication system mainly consists of an oil baffle 31, an oil injector 30, an electronic oil pump 27, an oil filter 28, an oil cooler 29, a left oil injection ring 39, and a right oil injection ring 40. The motor lubricating oil and the reducer lubricating oil use the same medium. The oil inlet of the electronic oil pump 27 is equipped with an oil baffle 31, positioning the inlet directly below the motor to prevent cavitation at large angles. The electronic oil pump 27 pumps oil through oil passages on the housing to the oil filter 28. The filtered oil then enters the oil cooler 29 through oil passages on the housing for cooling. The lubricating oil is then divided into two paths. One path enters the oil inlet chamber 34 and the central hole of the intermediate shaft 16 through the oil injector 30. The lubricating oil in the oil chamber 34 enters the fifth bearing 19 and then enters the sixth bearing 20 through the central hole of the intermediate shaft 16. The other path enters the first oil passage 35 on the motor housing 5. The first oil passage 35 further divides the oil path into two paths. One path passes through the second oil passage 36 on the end cover 4 to lubricate the first bearing 14. The other path enters the left oil injection ring 39, which is provided with several oil injection holes to lubricate the welded ends of the motor stator 10. The lubricating oil is cooled by spraying. The left oil spray ring 39 is connected to the gap between the motor stator 10 and the motor housing 5, forming the third oil passage 38. The lubricating oil enters the right oil spray ring 40, which has several axial and radial spray holes to spray and cool the crown end of the motor stator 10. The right oil spray ring 40 is connected to the first sub-oil passage 41 on the housing. The lubricating oil enters the second sub-oil passage 42 on the reducer housing 6 through the first sub-oil passage 41. The second sub-oil passage 42 on the reducer housing 6 has three oil ports for distributing oil. The oil ports are designated as first oil port 43, second oil port 44, and third oil port 45. First oil port 43 is aligned with the oil passage on bracket 23, introducing oil to lubricate the right bearing of the motor and the left bearing of differential 22. Second oil port 44 is aligned with the window of differential 22, spraying oil to lubricate differential 22. Third oil port 45 throttles the oil to lubricate fourth bearing 25. The lubricating oil output from third oil port 45 can be delivered to fourth bearing 25 through fifth oil passage 46. Oil return passages are provided at the bottom on both sides of the motor, and the cooled oil flows back to the second chamber.

[0034] The present invention also proposes a vehicle comprising the coaxial electric drive axle described in any of the preceding claims.

[0035] This invention adopts a coaxial design, aligning the center of the motor shaft 12 with the center of the drive axle, resulting in a compact structure. Compared to the traditional parallel-shaft offset output electric drive axle, the overall vehicle X-axis space is reduced by more than 100mm. The cooling and lubrication system employed in this invention provides active lubrication and cooling for all components requiring cooling and lubrication. Under the same conditions, the motor temperature is 10-15°C lower than that of traditional solutions. Simultaneously, the motor and reducer are isolated, effectively preventing unfiltered oil from contaminating the motor stator and rotor, thus significantly increasing motor lifespan. This invention utilizes an oil-cooled electric drive system, which, within the same volume, offers a significant increase in both power and torque (estimated at over 15%) compared to traditional water-cooled electric drives.

[0036] This invention adopts a deeply integrated solution: the high-speed gear of the reducer is integrated with the motor shaft 12, and the high-speed pinion is placed between the two bearings of the motor. Firstly, the outer diameter of the high-speed gear is reduced, which further increases the transmission ratio of the reducer, further reduces the output torque of the motor, increases the output torque of the reducer, and further effectively reduces the cost of the motor. Secondly, the inner diameter of the motor shaft 12 is increased, which further increases the space of the drive half shaft diameter, and further supports higher output torque. Thirdly, the cantilever structure of the high-speed gear is avoided, the gear meshing conditions are improved, the bearing stress is more reasonable, and further, the bearing life is longer and the NVH performance is better.

[0037] The lubrication channels are all integrated with the housing, reducing the number of parts by 15%. The integration of the motor shaft 12 with the reducer input shaft increases the speed ratio of the coaxial electric drive axle reducer by 50%, and with the same motor parameters, increases the output torque by 50%.

[0038] The primary drive gear 13 is placed between the two bearings of the motor, which avoids the cantilever structure of the high-speed gear, improves the gear meshing conditions, and makes the bearing stress more reasonable. Furthermore, the bearing life is longer and the NVH performance is better.

[0039] The above embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention. In the description of this specification, the reference to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., means that a specific feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples. Furthermore, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

Claims

1. A coaxial electric drive bridge, characterized in that, It includes a left drive half-shaft, a right drive half-shaft, and a powertrain; the powertrain includes a power housing, a motor stator, a motor rotor, a motor shaft, a first-stage drive gear, a first-stage driven gear, a second-stage drive gear, a second-stage driven gear, an intermediate shaft, a bracket, and a differential; the power housing has a first chamber and a second chamber located to the right of the first chamber, the motor stator is fixedly installed in the first chamber, and the bracket is fixedly installed in the second chamber; The left section of the motor shaft is located in the first chamber, and the left end of the motor shaft is rotatably supported on the power housing. The motor rotor is fixedly installed on the left section of the motor shaft and the motor rotor cooperates with the motor stator. The right section of the motor shaft is located in the second chamber, and the first-stage drive gear is fixed on the right section of the motor shaft. The right end of the motor shaft is rotatably supported on the bracket. The differential is located in the second chamber. The left end of the differential housing is rotatably supported on the bracket, and the right end of the differential housing is rotatably supported on the power housing. The secondary driven gear is fixed on the differential housing. The intermediate shaft is located in the second chamber. The left and right ends of the intermediate shaft are rotatably supported on the power housing. The first-stage driven gear and the second-stage driving gear are fixed on the intermediate shaft. The first-stage driven gear meshes with the first-stage driving gear, and the second-stage driven gear meshes with the second-stage driving gear. The motor shaft is a hollow shaft. The right end of the left drive half shaft passes through the motor shaft and is connected to the left half shaft gear of the differential. The left end of the right drive half shaft extends into the second chamber and is connected to the right half shaft gear of the differential. The left drive half shaft, the motor shaft, the differential, and the right drive half shaft are coaxially arranged. The central axis of the intermediate shaft is parallel to the central axis of the motor shaft.

2. The coaxial electric drive bridge according to claim 1, characterized in that, The primary drive gear is integrally formed with the motor shaft.

3. The coaxial electric drive bridge according to claim 1, characterized in that, The power housing includes an end cover, a motor housing, and a reducer housing, which are fixedly connected from left to right. The end cover and the motor housing form a first chamber, and the motor housing and the reducer housing form a second chamber.

4. The coaxial electric drive bridge according to claim 1, characterized in that, The motor housing is provided with a partition that separates the first chamber and the second chamber from each other.

5. The coaxial electric drive bridge according to claim 1, characterized in that, The intermediate shaft is a hollow shaft.

6. The coaxial electric drive bridge according to claim 1, characterized in that, It also includes a first bearing, a second bearing, a third bearing, a fourth bearing, a fifth bearing, and a sixth bearing. The motor shaft is connected to the power housing via the first bearing. The right end of the motor shaft is connected to the bracket via the second bearing. The left end of the differential housing is connected to the bracket via the third bearing. The right end of the differential housing is connected to the power housing via the fourth bearing. The left end of the intermediate shaft is connected to the power housing via the fifth bearing. The right end of the intermediate shaft is connected to the power housing via the sixth bearing.

7. The coaxial electric drive bridge according to claim 6, characterized in that, It also includes a cooling and lubrication system, which comprises an electronic oil pump, an oil filter, an oil cooler, a left injection ring, and a right injection ring. The electronic oil pump, the oil filter, and the oil cooler are all fixedly mounted on the power housing. The electronic oil pump, the oil filter, and the oil cooler are connected sequentially through connecting oil passages. An oil suction port is provided at the bottom of the second chamber. The electronic oil pump draws lubricating oil from the second chamber through the oil suction port. The lubricating oil output by the electronic oil pump enters the oil filter. The lubricating oil filtered by the oil filter is delivered to the oil cooler. An oil delivery passage is provided in the power housing. The lubricating oil output by the oil cooler is delivered through the oil delivery passage to the left injection ring, the right injection ring, the first bearing, the second bearing, the third bearing, the fourth bearing, the fifth bearing, the sixth bearing, and the differential. The left injection ring and the right injection ring are both located in the first chamber. The left injection ring is located on the left side of the motor stator, and the right injection ring is located on the right side of the motor stator.

8. The coaxial electric drive bridge according to claim 7, characterized in that, The intermediate shaft is a hollow shaft. The oil supply passage includes an oil inlet chamber, a first oil passage, a second oil passage, a third oil passage, and a fourth oil passage. The oil inlet chamber is located on the left side wall of the second chamber. An oil nozzle is provided at the inlet of the oil inlet chamber. The oil nozzle has an axial spray port and a radial spray port. The axial spray port is used to spray oil into the center hole of the intermediate shaft to lubricate the sixth bearing. The radial spray port is used to spray oil into the oil inlet chamber, which provides lubricating oil to the fifth bearing. The first oil passage is located within the shell wall of the power housing. One end of the first oil passage communicates with the oil inlet chamber, and the other end of the first oil passage has a connecting port that supplies lubricating oil to the left oil injection ring. The second oil passage is located within the shell wall of the power housing. One end of the oil passage is connected to the first oil passage, and the other end of the second oil passage extends to the first bearing to supply lubricating oil to the first bearing. The third oil passage is disposed between the power housing and the motor stator. The left end of the third oil passage is connected to the first oil passage through a connecting port, and the right end of the third oil passage extends to the right fuel injection ring to supply lubricating oil to the right fuel injection ring. The fourth oil passage is disposed inside the shell wall of the power housing. One end of the fourth oil passage is connected to the right fuel injection ring. The fourth oil passage is provided with a first oil port, a second oil port, and a third oil port. The first oil port is used to supply lubricating oil to the second and third bearings, the second oil port is used to supply lubricating oil to the differential, and the third oil port is used to supply lubricating oil to the fourth bearing.

9. The coaxial electric drive bridge according to claim 7, characterized in that, The oil extraction port is located on the left side wall of the second chamber, and a baffle is provided to the right of the oil extraction port.

10. A vehicle, characterized in that, Includes the coaxial electric drive axle as described in any one of claims 1-9.

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