Electric drive bridge and automobile

Abstract

The present application discloses an electric drive axle and a car. The electric drive axle is transversely arranged on the chassis of the vehicle, and includes a motor assembly, a reducer assembly and a differential assembly. The motor assembly and the differential assembly are respectively arranged on both sides of the reducer assembly, and the reducer assembly includes a three-stage reduction mechanism; in the electric working condition, the motor power is decelerated by the three-stage reduction mechanism and then transmitted to the differential assembly, and the differential assembly distributes and outputs power to the left and right wheels of the vehicle. The electric drive axle in the present application occupies a small space, and the overall weight distribution is balanced, which improves the safety of the car; the three-stage reduction mechanism avoids the high-speed motor shaft directly transmitting power to the gear set of the differential assembly, and improves the stability and reliability of the electric drive axle.

Description

Technical Field

[0001] The present application relates to the field of automobile power technology, and in particular to an electric drive axle and an automobile. Background Art

[0002] In areas such as automotive powertrains, hybrid electric drive systems require an engine-driven generator as a backup power source, so the engine and generator occupy a large portion of the cabin space. The space for the electric axle is limited, and the axle envelope is unusually shaped like a dumbbell, with ample space near the wheels and less space in the middle, thus restricting its structural layout. Furthermore, the direct transmission of motor power to the differential via the crankshaft increases wear on the transmission mechanism and reduces the smoothness and stability of the electric axle. Furthermore, some vehicles are four-wheel drive, and the power source cannot be switched between two-wheel drive and four-wheel drive at will.

[0003] It should be noted that the statements herein merely provide background information related to the present application and do not necessarily constitute prior art. Utility Model Content

[0004] In view of the above problems, the present application proposes an electric drive axle and a vehicle that overcome the above problems or at least partially solve the above problems.

[0005] The embodiments of this application adopt the following technical solutions:

[0006] In a first aspect, an embodiment of the present application provides an electric drive axle, which is laterally arranged on a vehicle chassis. The electric drive axle includes a motor assembly, a reducer assembly and a differential assembly. The motor assembly and the differential assembly are respectively arranged on both sides of the reducer assembly. The reducer assembly includes a three-stage reduction mechanism. In electric operation, the motor power is decelerated by the three-stage reduction mechanism and then transmitted to the differential assembly. The differential assembly distributes and outputs power to the left and right wheels of the vehicle.

[0007] Preferably, the three-stage reduction mechanism includes a first countershaft group and a second countershaft group, the first countershaft group includes a first countershaft, a first-stage large gear, and a second-stage pinion, the second countershaft group includes a second countershaft, a second-stage large gear, and a third-stage pinion, the first countershaft and the second countershaft are parallel to the motor shaft, and the second-stage pinion is engaged with the second-stage large gear.

[0008] Preferably, the motor assembly includes a motor housing, a motor shaft, and a first-stage pinion gear. The first-stage pinion gear is integrated with the motor shaft, and the first-stage pinion gear is meshed with the first-stage gearwheel.

[0009] Preferably, the differential assembly includes a third-stage large gear, an outer differential case, an inner differential case, a gear set and a split clutch, the gear set is arranged on the inner differential case, the third-stage large gear is integrated on the outer differential case, the inner differential case is supported in the outer differential case by a needle bearing, and the third-stage large gear is meshed with the third-stage small gear; the split clutch is arranged between the inner differential case and the outer differential case, and the inner differential case and the outer differential case are locked into an integrated movement or separated and moved independently through the first action or the second action of the split clutch.

[0010] Preferably, the reducer assembly further includes a reducer housing and a reducer cover, and the reducer housing and the reducer cover are connected by bolts.

[0011] Preferably, the electric drive axle further includes a left bridge tube and a right bridge tube, the left bridge tube is fixedly connected to the left end surface of the motor housing, and the right bridge tube is fixedly connected to the right end surface of the reducer cover.

[0012] Preferably, the electric drive axle also includes a parking mechanism, which includes a parking arm and a parking gear. The parking gear is fixedly connected to the motor shaft and is arranged on the outside of the first-stage pinion. The vehicle is controlled to be in a parking state and a non-parking state respectively by engaging or disengaging the parking arm and the parking gear.

[0013] Preferably, the motor shaft comprises a hollow shaft, the gear set comprises a left side gear and a right side gear. The electric drive axle further comprises a left output shaft and a right output shaft, the left output shaft passing through the left axle tube and the hollow shaft to connect to the left side gear, and the right output shaft passing through the right axle tube to connect to the right side gear.

[0014] In a second aspect, an embodiment of the present application further provides a car comprising an electric drive axle as described in any one of the first aspects.

[0015] At least one of the above technical solutions adopted in the embodiments of the present application can achieve the following beneficial effects:

[0016] The three-stage reduction mechanism in this application reduces the length of the motor shaft, improves the motor shaft rigidity, reduces the bearing support structure, and avoids the high-speed motor shaft directly transmitting power to the differential gear set through the slender shaft, thereby improving stability. At the same time, the electric drive axle motor and differential are arranged on both sides of the reducer, and the weight distribution on the left and right sides is even. The structure is compact and can meet the requirements of the hybrid electric drive system being arranged simultaneously with the engine and generator, or the pure electric system arrangement.

[0017] The above description of the technical solution of the present application is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference symbols are used throughout the drawings to represent the same components. In the drawings:

[0019] Figure 1 This is a schematic diagram of the electric drive bridge structure in an embodiment of the present application;

[0020] Figure 2 This is a disassembly diagram of the electric drive bridge in the embodiment of the present application;

[0021] In the figure, 1-motor assembly 11-motor rotor 12-motor stator 13-motor shaft 14-first stage pinion 15-motor housing 16-parking gear 2-first countershaft group 21-first stage large gear 22-second stage pinion 23-first countershaft 3-second countershaft group 31-second stage large gear 32-third stage pinion 33-second countershaft 4-differential assembly 41-third stage large gear 42-outer differential housing 43-inner differential housing 44-gear group 45-split clutch 51-reducer housing 52-reducer cover 53-left bridge pipe 54-right bridge pipe 61-left output shaft 62-right output shaft DETAILED DESCRIPTION

[0022] To make the purpose, technical solutions, and advantages of this application more clear, the technical solutions of this application will be clearly and completely described below in conjunction with the specific embodiments of this application and the corresponding drawings. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0023] The idea of ​​this application is to design an electric drive bridge with strong universality in response to the current situation in the prior art where the electric drive bridge structure layout is not ideal and the transmission structure stability is poor. The electric drive bridge has a reasonable structure layout, balanced left and right weights, and a three-stage reduction mechanism for the reducer, which reduces the motor shaft length, increases the motor shaft stiffness, reduces the bearing support structure, and improves the stability of the electric drive bridge.

[0024] The following describes in detail the technical solutions provided by various embodiments of the present application in conjunction with the accompanying drawings.

[0025] The embodiment of the present application provides an electric drive bridge and a car, such as Figure 1 As shown, a schematic diagram of the electric drive axle structure in an embodiment of the present application is provided, wherein the electric drive axle is transversely arranged on the vehicle chassis, and comprises a motor assembly 1, a reducer assembly and a differential assembly 4, wherein the motor assembly 1 and the differential assembly 4 are respectively arranged on both sides of the reducer assembly, and the reducer assembly comprises a three-stage reduction mechanism; in electric operation, the motor power is decelerated by the three-stage reduction mechanism and then transmitted to the differential assembly, and the differential assembly distributes and outputs power to the left and right wheels of the vehicle.

[0026] Depend on Figure 1 It can be seen that the motor assembly includes components such as the motor rotor 11, the motor stator 12, the motor shaft 13, the first-stage pinion 14, the motor housing 15, and the parking gear 16. Among them, the motor shaft 13 is a hollow shaft, the motor stator 12 is fixedly connected to the motor housing 15, the motor rotor 11 is fixedly connected to the motor shaft 13, the first-stage pinion 14 is integrated with the motor shaft 13, and the parking gear 16 is fixedly connected to the motor shaft 13. The parking gear 16 is arranged on the outside of the motor shaft 13. In this application, the motor shaft and the first-stage pinion are integrally processed and formed without splines, which reduces the cumulative assembly error and has high precision.

[0027] Combine Figure 2 It can be seen that the reducer assembly includes a three-stage reduction mechanism, a reducer housing 51 and a reducer cover 52. The reducer housing 51 is connected to the motor housing 15 by bolts, and the reducer cover 52 is connected to the reducer housing 51 by bolts; wherein the three-stage reduction mechanism includes a first countershaft group 2 and a second countershaft group 3, the first countershaft group 2 includes a first-stage large gear 21, a second-stage small gear 22 and a first countershaft 23, the second-stage small gear 22 and the first countershaft 23 and the first-stage large gear 21 are integrated or connected by spline assembly, and the second-stage small gear The wheel 22 and the first-stage large gear 21 are respectively arranged at the two ends of the first countershaft 23, and the diameter of the first-stage large gear 21 is larger than the diameter of the second-stage pinion 22; the second countershaft group 3 includes a second-stage large gear 31, a third-stage pinion 32 and a second countershaft 33, and the third-stage pinion 32, the second countershaft 33 and the second-stage large gear 31 are integrated into one or connected by spline assembly. The third-stage pinion 32 and the second-stage large gear 31 are respectively arranged at the two ends of the second countershaft 33, and the diameter of the second-stage large gear 31 is larger than the diameter of the third-stage pinion 32.

[0028] Combine Figure 2It can be seen that the differential assembly 4 includes a third-stage large gear 41, an outer differential housing 42, an inner differential housing 43, a gear set 44, and a split clutch 45. Among them, the gear set 44 includes a left half-shaft gear and a right half-shaft gear. The third-stage large gear 41 is connected to the outer differential housing 42. The inner differential housing 43 is supported in the outer differential housing 42 through a needle bearing. The gear set 44 is installed on the inner differential housing. The split clutch 45 is arranged between the outer differential housing 42 and the inner differential housing 43. When the split clutch 45 is engaged, the outer differential housing 42 and the inner differential housing 43 are locked as one. The differential housing and inner differential housing are drivingly connected. The outer differential housing transmits power to the inner differential housing, driving the differential to rotate. The differential then transmits power to the left and right output shafts. At this point, the electric drive axle provides power to the wheels. When the splitter clutch 45 is disengaged, the outer differential housing 42 and the inner differential housing 43 separate and can rotate independently. At this point, there is no driving connection between the outer differential housing and the inner differential housing. The outer differential housing does not transmit power to the inner differential housing, the power to the differential is cut off, and the electric drive axle does not provide power to the wheels. In summary, this differential assembly can quickly cut off or engage differential power, and has the advantages of high torque transmission efficiency, long service life, compact structure, and easy layout within the vehicle.

[0029] In some examples of the present application, the diameter of the first-stage large gear 21 is larger than the diameter of the first-stage small gear 14, the diameter of the second-stage large gear 31 is larger than the diameter of the second-stage small gear 22, the diameter of the third-stage large gear 41 is larger than the diameter of the third-stage small gear 32, and at the same time, the diameter of the third-stage large gear 41 is larger than the diameters of the first-stage large gear 21 and the second-stage large gear 31.

[0030] Combine Figure 1 、 Figure 2The first and second countershafts 23, 33 are parallel to the motor shaft 13, and the motor assembly and differential assembly are aligned, ensuring transmission efficiency. The first-stage pinion 14 on the motor shaft 13 meshes with the first-stage gearwheel 21 on the first countershaft assembly 2, the second-stage pinion 22 on the first countershaft assembly 2 meshes with the second-stage gearwheel 31 on the second countershaft assembly 3, and the third-stage pinion 32 on the second countershaft assembly 3 meshes with the third-stage gearwheel 41 on the differential assembly 4. The first and second countershaft assembly 2, 3 are fixed to the reducer assembly via different bearings. In this application, the two-bearing design of the motor reduces the axial length and improves transmission efficiency compared to the three-bearing design. In this application, the first-stage gear set is arranged near the motor side, where the motor shaft is a small-diameter high-speed shaft to reduce the motor shaft length, increase the motor shaft rigidity, reduce the bearing support structure, and is more favorable for the selection of high-speed bearings. The first countershaft 2 transmits the motor power to the second-stage gear set arranged on the right after the first-stage reduction, avoiding the high-speed motor shaft directly transmitting power from the left side through the slender shaft to the right gear set; making the overall component design and bearing selection more reasonable and improving reliability.

[0031] like Figure 1 As shown, the electric drive axle in this application also includes a left bridge tube 53 and a right bridge tube 54. The left bridge tube 53 is connected to the left end face of the motor housing 51, and the right bridge tube 54 is connected to the right end face of the reducer cover 52. The left bridge tube 53 and the right bridge tube 54 are used to fix the electric drive axle to the vehicle chassis.

[0032] The electric drive axle in this application also includes a left output shaft 61 and a right output shaft 62. The left output shaft 61 passes through the center hole of the left bridge tube 53 and the motor shaft 13 to connect with the left half-shaft gear of the differential assembly 4. The right output shaft 62 passes through the center hole of the right bridge tube 54 to connect with the right half-shaft gear of the differential assembly 4. Figure 1 As can be seen, the electric drive axle's motor assembly 1 is positioned to the left of the reducer assembly, while the differential assembly 4 is positioned to the right. The electric drive axle utilizes parallel shaft gearing, with the motor shaft 13, left output shaft 61, and right output shaft 62 arranged coaxially. The overall structure of the electric drive axle resembles a dumbbell, with larger ends and a smaller center. The motor housing and reducer housing serve as the center section, while the motor and differential are positioned on the left and right sides, ensuring weight balance on both sides of the axle. The simple structure, compact footprint, and high integration make it suitable for hybrid electric drive system layout and four-wheel drive space division requirements.

[0033] In some embodiments of the present application, the electric drive axle further includes a parking mechanism, comprising a parking arm and a parking gear 16. The parking gear 16 is fixedly connected to the motor shaft and disposed outside the first-stage pinion 14. The engagement or disengagement of the parking arm and the parking gear 16 controls the vehicle's position between park and non-park, respectively. Specifically, the parking gear 16 is fixedly connected to the motor shaft 13 of the motor assembly. When the parking arm of the parking mechanism engages the parking gear 16, the motor shaft is restricted from rotating, and the electric drive axle is in the P gear position. When the parking arm of the parking mechanism disengages the parking gear, the motor shaft is free to rotate, and the electric drive axle is in the non-P gear position. The parking gear is arranged on the motor shaft, has a low load, is compact, and is lightweight. The parking mechanism in the present application is arranged on the motor shaft. In conjunction with the gear ratio of the transmission, the parking mechanism can achieve a high wheel braking torque requirement with a small weight and volume. Furthermore, the lightweight parking gear effectively improves the efficiency of the entire electric drive axle.

[0034] As a specific embodiment of the present application, the electric drive axle is a transverse electric drive axle, installed on the vehicle chassis. The reducer assembly is a three-stage parallel shaft reducer, with the motor shaft 13, left output shaft 61, and right output shaft 62 arranged coaxially. The motor is located on the left side of the entire electric drive axle, and the reducer is located on the right side of the entire electric drive axle. The left bridge tube 53 is fixedly connected to the left end face of the motor housing, and the right bridge tube 54 is fixedly connected to the right end face of the reducer cover. Preferably, the left bridge tube 53 is integrally integrated with the left end face of the motor housing, and the right bridge tube 54 is integrally integrated with the right end face of the reducer cover. High-strength, high-toughness materials are used to optimize cross-sectional wall thickness, optimize stress distribution, reduce weight, improve overall performance consistency, and reduce post-weld stress deformation. The motor assembly, reducer assembly, and differential assembly (including the split clutch) are first assembled into components and then assembled into one, improving manufacturing processability. The split clutch is integrated with the differential. During splitting, only part of the differential gear set and the inner differential housing rotate, effectively reducing system losses, improving efficiency, and saving layout space.

[0035] In this application, the electric drive axle is divided into multiple working modes. When in electric working condition, the inner differential case and the outer differential case of the differential are connected as one through the split clutch. The motor power is transmitted to the outer differential case of the differential after three-stage reduction through the reducer, and then transmitted to the inner differential case through the engaged split clutch. The power is then distributed through the differential gear set and then transmitted to the left output shaft to the left wheel and the right output shaft to the right wheel for power output.

[0036] When in power generation mode, the inner and outer differential cases of the differential are connected as one through a split clutch. The inertial power flow from the left and right wheels is transmitted to the differential through the left output shaft and the right output shaft respectively. After the differential transmits the power flow to the inner differential case, it is transmitted to the outer differential case through the engaged split clutch. Finally, it is transmitted to the motor after three-stage acceleration through the reducer to drive the motor to generate electricity.

[0037] When the split working condition is in effect, that is, two-wheel drive, and the drive axle does not need to participate in the work, the inner differential case and the outer differential case of the differential are separated by the split clutch, and the inertia power of the left and right wheels is transmitted to the differential gear set through the left output shaft and the right output shaft respectively. Since the split clutch is disengaged at this time, the power of the inner differential case and the outer differential case is interrupted, and the components between the outer differential case and the motor shaft (differential housing, first countershaft group, second countershaft group, motor shaft) stop rotating. Only the left and right wheels drive the left and right output shafts, the differential gear set and the inner differential case to rotate, thereby completely eliminating the motor loss of the reverse dragging of the electric drive axle, and almost completely eliminating the gearbox loss of the reverse dragging of the electric drive axle, effectively reducing system loss and improving efficiency.

[0038] In some examples of the present application, a car is also provided, including the electric drive axle as described above. For other parts of the car, reference may be made to the prior art and will not be repeated in this application.

[0039] It should be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0040] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0041] The foregoing is merely an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should all be included within the scope of the claims of the present application.

[0042] It should be noted that, in the description of this application, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance. In addition, in the description of this application, unless otherwise specified, the meaning of "plurality" is two or more.

[0043] In this application, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0044] In this application, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0045] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code comprising one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may be performed out of the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by those skilled in the art to which the embodiments of the present application belong.

[0046] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present application. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0047] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. An electric drive bridge, characterized in that: The electric drive axle is transversely arranged on the vehicle chassis, and the electric drive axle includes a motor assembly, a reducer assembly and a differential assembly. The motor assembly and the differential assembly are respectively arranged on both sides of the reducer assembly, and the reducer assembly includes a three-stage reduction mechanism; In electric operation, the motor power is decelerated by the three-stage reduction mechanism and then transmitted to the differential assembly, and the differential assembly distributes and outputs power to the left and right wheels of the vehicle.

2. The electric drive bridge according to claim 1, characterized in that: The three-stage reduction mechanism includes a first countershaft group and a second countershaft group, the first countershaft group includes a first countershaft, a first-stage large gear, and a second-stage small gear, the second countershaft group includes a second countershaft, a second-stage large gear, and a third-stage small gear, the first countershaft, the second countershaft and the motor shaft are parallel to each other, and the second-stage small gear is meshed with the second-stage large gear.

3. The electric drive axle as claimed in claim 2, characterized in that: The motor assembly includes a motor housing, a motor shaft, and a first-stage pinion gear. The first-stage pinion gear is integrated with the motor shaft, and the first-stage pinion gear is meshed with the first-stage gear.

4. The electric drive axle as claimed in claim 3, characterized in that: The differential assembly includes a third-stage large gear, an outer differential housing, an inner differential housing, a gear set and a split clutch, wherein the gear set is arranged on the inner differential housing, the third-stage large gear is integrated on the outer differential housing, the inner differential housing is supported in the outer differential housing through a needle bearing, and the third-stage large gear is meshed with the third-stage small gear; The split clutch is arranged between the inner differential case and the outer differential case, and the inner differential case and the outer differential case are locked to move as a whole or to move separately through the first action or the second action of the split clutch.

5. The electric drive bridge as claimed in claim 4, characterized in that: The reducer assembly also includes a reducer housing and a reducer cover, and the reducer housing and the reducer cover are connected by bolts.

6. The electric drive axle as claimed in claim 5, characterized in that: The electric drive axle also includes a left bridge tube and a right bridge tube. The left bridge tube is fixedly connected to the left end surface of the motor housing, and the right bridge tube is fixedly connected to the right end surface of the reducer cover.

7. The electric drive axle as claimed in claim 3, characterized in that: The electric drive axle also includes a parking mechanism, which includes a parking arm and a parking gear. The parking gear is fixedly connected to the motor shaft and is arranged on the outer side of the first-stage pinion. The vehicle is controlled to be in a parking state and a non-parking state respectively by engaging or disengaging the parking arm and the parking gear.

8. The electric drive axle as claimed in claim 6, characterized in that: The motor shaft comprises a hollow shaft, and the gear set comprises a left half-shaft gear and a right half-shaft gear.

9. The electric drive axle as claimed in claim 8, characterized in that: The electric drive axle also includes a left output shaft and a right output shaft. The left output shaft passes through the left bridge tube and the hollow shaft to be connected to the left half-shaft gear, and the right output shaft passes through the right bridge tube to be connected to the right half-shaft gear.

10. An automobile, characterized in that: Comprising an electric drive bridge as claimed in any one of claims 1-9.

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