Three-speed light-weight electric drive axle assembly

Abstract

The present invention discloses a three-speed light-weight electric drive axle assembly, which is mainly composed of a differential assembly, a split reduction box housing assembly, a spur gear reduction gear assembly, an input shaft assembly, a planetary gear reduction assembly, and three clutch assemblies. The differential assembly housing is coaxially fixedly connected with the first spur gear, the third spur gear is coaxially fixedly connected with the second planet carrier loosely sleeved on the input shaft, and in the two planetary gear trains of the planetary gear reduction assembly, two sun gears are sequentially mounted on the input shaft, the second outer ring is coaxially fixedly connected with the first planet carrier, and the three clutch assemblies are respectively mounted between the first outer ring and the input shaft, the first outer ring and the split reduction box housing assembly, and the second outer ring and the split reduction box housing assembly. The present invention integrates and optimizes the electric vehicle drive axle and the gearbox structure while realizing accurate and rapid three-speed switching and shifting, which greatly meets the demand for lightness.

Description

Technical Field

[0001] The invention belongs to the technical field of electric vehicle transmission, and in particular relates to a three-speed light-weight electric drive axle assembly. Background Art

[0002] In current electric vehicles, electric drive axles still have many deficiencies, and it is difficult to meet the requirements of lightweight and multiple gears at the same time. The electric drive axles used in existing electric vehicles still retain the drive axle structure of the transmission vehicle, and existing electric vehicles have the problem of fewer gears. For this problem, in existing research and design, it has become a trend to intelligently connect the drive axle with the motor. Then, while ensuring the number of gears of electric vehicles, making the drive axle structure lightweight will become a hot issue. Therefore, the current problems that need to be solved in electric drive axles are mainly the following two points:

[0003] 1. Currently, many electric vehicles have few gears and can only adjust the speed through the motor;

[0004] 2. The current drive axle structure of electric vehicles is similar to that of traditional automobiles. This structure causes the drive axle to be too heavy and consumes a lot of energy. Summary of the invention

[0005] In view of the defects existing in the above-mentioned prior art, the present invention discloses a three-speed light-weight electric drive axle assembly, which increases the number of electric vehicle gears while optimizing the drive axle structure design and reducing the overall weight of the drive axle. Combined with the drawings of the specification, the technical solution of the present invention is as follows:

[0006] The three-speed light-weight electric drive axle assembly is composed of a differential assembly 1, a separate reduction gearbox housing assembly 2, a reduction gearbox end cover assembly 3, a spur gear reduction gear assembly 4, an input shaft assembly 5, a planetary gear reduction assembly 6 and three clutch assemblies;

[0007] The housing of the differential assembly 1 is coaxially fixedly connected to the first spur gear 12 of the upper spur reduction gear assembly 4;

[0008] In the spur gear reduction gear assembly 4, the first spur gear 12, the second spur gear 13 and the third spur gear 19 are meshed and connected in sequence, the third spur gear 19 is coaxially fixedly connected with the rotating sleeve of the second planet carrier 18 in the planetary gear reduction assembly 6, and the rotating sleeve of the second planet carrier 18 is loosely sleeved on the input shaft 17 of the spur gear reduction gear assembly 4;

[0009] The planetary gear reduction assembly 6 is composed of two sets of planetary gear trains arranged axially along the input shaft 17, wherein the second sun gear 20b and the first sun gear 20a are coaxially fixed on the input shaft 17 in sequence, and the second outer ring 25 is coaxially fixedly connected with the first planet carrier 23;

[0010] In the first clutch 7, the first clutch support frame 32 is coaxially fixed to the input shaft 17, the first friction plate 28a is coaxially mounted on the first clutch support frame 32, the first steel plate 30a and the first friction plate 28a are matched and mounted on the inner circumferential wall of the first outer ring 26, and the separation or combination of the first friction plate 28a and the first steel plate 30a is controlled to control the separation or combination of the first outer ring 26 and the input shaft 17;

[0011] In the second clutch 8, the second friction plate 28b is coaxially fixed to the outer circumferential surface of the first outer ring 26, and the second steel plate 30b is matched with the second friction plate 28b and mounted on the inner wall of the split reduction gearbox housing assembly 2, and the separation or combination of the first outer ring 26 and the split reduction gearbox housing assembly 2 is controlled by controlling the separation or combination of the second friction plate 28b and the second steel plate 30b;

[0012] In the third clutch 9, the third friction plate 28c is coaxially fixed to the outer circumferential surface of the second outer ring 25, and the third steel plate 30c is mounted on the inner wall of the separate reduction gearbox housing assembly 2 in a matching manner with the third friction plate 28c. The separation or combination of the third friction plate 28c and the third steel plate 30c is controlled to control the separation or combination of the second outer ring 25 and the separate reduction gearbox housing assembly 2.

[0013] Furthermore, in the spur gear reduction gear assembly 4, the second spur gear 13 is loosely sleeved on the second spur gear shaft 14 through the first copper sleeve 15, the second spur gear shaft 14 is arranged in parallel below the input shaft 17 of the input shaft assembly 5, and both ends of the second spur gear shaft 14 are respectively mounted on the separate reduction gearbox housing assembly 2;

[0014] The third spur gear 19 and the second spur gear 13 are in equal ratio transmission, and the transmission ratio of the second spur gear 13 to the first spur gear 12 is greater than 1.

[0015] Further, in the planetary gear reduction assembly 6, the first planetary gear train is composed of a first sun gear 20a, a first planetary gear 22a, a first planet carrier 23 and a first outer ring 26;

[0016] The first sun gear 20a is installed on the input shaft 17 through a flat key 21, and the first planetary gears 22a are respectively loosely mounted on the short shafts of the planetary gear shaft frame of the first planetary carrier 23 through the third copper sleeve 24a. The first planetary carrier 23 and the second outer ring 25 in the second planetary gear system are an integrally formed structure. The first planetary gear 22a is respectively meshed with the first sun gear 20a and the first outer ring 26, and one end of the first outer ring 26 is installed in the groove of the separate reduction gearbox housing assembly 2.

[0017] Further, in the planetary gear reduction assembly 6, the second planetary gear train is composed of a second sun gear 20b, a second planetary gear 22b, a second planet carrier 18 and a second outer ring 25;

[0018] The second planetary carrier 18 is coaxially mounted on the input shaft 17, and the rotating sleeve of the second planetary carrier 18 is loosely sleeved on the input shaft 17 through the second copper sleeve 16. The outer side of the rotating sleeve of the second planetary carrier 18 is connected to the third spur gear 19 through a spline. The second planetary gears 22b are loosely sleeved on the short shafts of the planetary gear shaft frame of the second planetary carrier 18 through the fourth copper sleeve 24b. The second sun gear 20b and the input shaft 17 are arranged as an integrated structure. The second planetary gears 22b are respectively meshed with the second sun gear 20b and the second outer ring 25, and one end of the second outer ring 25 is sleeved on the convex edge at the corresponding position of the split reduction gearbox housing assembly 2.

[0019] Further, in the first clutch assembly 7, a first hydraulic cavity is formed between the first piston 29a and the side wall of the split reduction gearbox housing assembly 2, a first hydraulic oil port is opened on the split reduction gearbox housing assembly 2 corresponding to the first hydraulic cavity, the outer ring of the first piston 29a is matched and installed with the split reduction gearbox housing assembly 2, the inner ring of the first piston 29a is matched and connected with the input shaft 17, the first spring 27a is installed in the annular groove of the end face of the first clutch support frame 32, one end of the first spring 27a is connected to the bottom of the annular groove of the first clutch support frame 32, the other end of the first spring 27a is connected to the end face of the first piston 29a, and a circle of pressure plate is provided on the outer circumference of the end face of the first piston 29a, and the pressure plate corresponds to the first steel plate 30a and the first friction plate 28a;

[0020] When the pressure in the first hydraulic chamber increases, the first piston 29a squeezes the first steel plate 30a and combines with the first friction plate 28a, so that the first outer ring 26 is engaged and fixed with the first clutch support frame, and then the first outer ring 26 is engaged and fixed with the input shaft 17. When the pressure in the first hydraulic chamber drops to zero, under the action of the restoring force of the first spring 27a, the first steel plate 30a and the first friction plate 28a are separated and restored to their original positions, and at this time, the first outer ring 26 and the input shaft 17 are also separated.

[0021] Further, in the second clutch assembly 8, a second hydraulic cavity is formed between the second piston 29b and the side wall of the split reduction gearbox housing assembly 2, a second hydraulic oil port is opened on the split reduction gearbox housing assembly 2 corresponding to the second hydraulic cavity, and a second spring 27b is installed between the second piston 29b and the second steel sheet 30b;

[0022] When the pressure in the second hydraulic chamber increases, the second piston 29b squeezes the second steel plate 30b and combines with the second friction plate 28b, thereby making the first outer ring 26 engage and fix with the side wall of the separate reduction gearbox housing assembly 2; when the pressure in the second hydraulic chamber drops to zero, under the action of the restoring force of the second spring 27b, the second steel plate 30b and the second friction plate 28b are separated and restored to their original positions; at this time, the first outer ring 26 is also separated from the side wall of the separate reduction gearbox housing assembly 2.

[0023] Further, in the third clutch 9, a third hydraulic cavity is formed between the third piston 29c and the side wall of the split reduction box housing assembly 2, a third hydraulic oil port is opened on the split reduction box housing assembly 2 corresponding to the third hydraulic cavity, and a third spring 27c is installed between the third piston 29c and the third steel sheet 30c;

[0024] When the pressure in the third hydraulic chamber increases, the third piston 29c squeezes the third steel plate 30c and combines with the third friction plate 28c, thereby making the second outer ring 25 engage and fix with the side wall of the split reduction gearbox housing assembly 2. When the pressure in the third hydraulic chamber drops to zero, under the action of the restoring force of the third spring 27c, the third steel plate 30c and the third friction plate 28c are separated and restored to their original positions. At this time, the second outer ring 25 is also separated from the side wall of the split reduction gearbox housing assembly 2.

[0025] Furthermore, lubricating oil is used between the friction plates and steel plates in the first clutch assembly 7, the second clutch assembly 8 and the third clutch assembly 9, and the lubricating oil channels in the first clutch assembly 7, the second clutch assembly 8 and the third clutch assembly 9 are connected to the lubricating oil channels of the planetary gear reduction assembly 6.

[0026] Furthermore, the separate reduction gearbox housing assembly 2 is composed of a first reduction gearbox housing 31a, a second reduction gearbox housing 31b and a third reduction gearbox housing 31c which are bolted together in sequence from left to right, and the gaps between the first reduction gearbox housing 31a and the second reduction gearbox housing 31b and between the second reduction gearbox housing 31b and the third reduction gearbox housing 31c are sealed with sealing tape or sealant.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The three-speed light-weight electric drive axle assembly of the present invention adopts three sets of clutch assemblies, and realizes the three gear changes of direct gear, medium speed gear and low speed gear of the electric vehicle by controlling the engagement or separation of each clutch assembly;

[0029] 2. The three-speed light-weight electric drive axle assembly of the present invention is optimized in structure, making the structure of the drive axle assembly more compact and having outstanding advantages in terms of lightness;

[0030] 3. In the three-speed light-weight electric drive axle assembly of the present invention, the friction plate and steel plate of the clutch are connected with the lubrication part of the planetary gear part, which reduces the number of parts and increases the convenience of assembly and improves the assembly accuracy;

[0031] 4. In the three-speed light-weight electric drive axle assembly of the present invention, the use of a split gearbox reduces the difficulty of assembly and provides more possibilities for design. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the overall internal structure of the three-speed light-weight electric drive axle assembly of the present invention;

[0033] Figure 2 It is a structural schematic diagram of a differential assembly in the three-speed light-weight electric drive axle assembly of the present invention;

[0034] Figure 3 It is a structural schematic diagram of a spur gear reduction gear assembly in the three-speed light-weight electric drive axle assembly of the present invention;

[0035] Figure 4 It is a structural schematic diagram of the planetary gear reduction assembly in the three-speed light-weight electric drive axle assembly of the present invention;

[0036] Figure 5 It is a structural schematic diagram of a clutch assembly in the three-speed light-weight electric drive axle assembly of the present invention;

[0037] Figure 6 This is a structural schematic diagram of a separate reduction gearbox housing assembly in the three-speed light-weight electric drive axle assembly of the present invention; in the figure:

[0038] 1 Differential assembly, 2 Separate reduction gearbox housing assembly, 3 Reduction gearbox end cover assembly,

[0039] 4 spur gear reduction gear assembly, 5 input shaft assembly, 6 planetary gear reduction assembly,

[0040] 7 first clutch assembly, 8 second clutch assembly, 9 third clutch assembly,

[0041] 10 differential bearing, 11 joint screw, 12 first spur gear,

[0042] 13 second spur gear, 14 second spur gear shaft, 15 first copper sleeve,

[0043] 16 second copper sleeve, 17 input shaft, 18 second planet carrier,

[0044] 19 the third spur gear, 20a the first sun gear, 20b the second sun gear,

[0045] 21 flat key, 22a first planetary gear, 22b second planetary gear,

[0046] 23 first planet carrier, 24a third copper sleeve, 24b fourth copper sleeve,

[0047] 25 second outer ring 26 first outer ring, 27a first spring,

[0048] 27b second spring, 27c third spring, 28a first friction plate,

[0049] 28b second friction plate, 28c third friction plate, 29a first piston,

[0050] 29b second piston, 29c third piston, 30a first steel sheet,

[0051] 30b the second steel sheet, 30c the third steel sheet, 31c the first reduction box housing,

[0052] 31b second reduction gearbox housing, 31c third reduction gearbox housing, 32 first clutch support frame. DETAILED DESCRIPTION

[0053] To further illustrate the technical solution and specific working process of the present invention, the specific implementation of the present invention is as follows in conjunction with the accompanying drawings:

[0054] like Figure 1 As shown, the present invention provides a three-speed light-weight electric drive axle assembly, including a differential assembly 1, a split-type reduction gear housing assembly 2, a reduction gear end cover assembly 3, a spur gear reduction gear assembly 4, an input shaft assembly 5, a planetary gear reduction assembly 6, a first clutch assembly 7, a second clutch assembly 8 and a third clutch assembly 9. The differential assembly 1, the spur gear reduction gear assembly 4, the input shaft assembly 5, the planetary gear reduction assembly 6, the first clutch assembly 7, the second clutch assembly 8 and the third clutch assembly 9 are all arranged in the split-type reduction gear housing assembly 2, and the power is input from the right end of the input shaft assembly 5, and then passes through the planetary gear reduction assembly 6 and the spur gear reduction gear assembly 4 in turn along the lateral direction to the left, and then output from the differential assembly 1 arranged below the spur gear reduction gear assembly 4; the electric drive axle assembly of the present invention realizes the switching between the three gears by controlling the combination or separation of the first clutch assembly 7, the second clutch assembly 8 and the third clutch assembly 9 installed at different positions around the planetary gear reduction assembly 6.

[0055] like Figure 1 and Figure 2As shown, the differential assembly 1 is arranged below the three-speed light-weight electric drive axle assembly. The structure of the differential assembly 1 is similar to that of a conventional differential. The left and right ends of the differential assembly 1 are rotatably mounted on the lower part of the split reduction gearbox housing assembly 2 through a differential bearing 10 respectively. Unlike the conventional differential structure, the housing of the differential assembly 1 is not connected to the bevel gear. The housing of the differential assembly 1 is coaxially fixedly connected to the first spur gear 12 in the spur reduction gear assembly 4 through a coupling screw 11. After the power is transmitted through the spur reduction gear assembly 4, it is directly transmitted from the first spur gear 12 to the housing of the differential assembly 1 to achieve power output.

[0056] The input shaft assembly 5 is composed of an input shaft 17 and an input shaft mounting bearing, and the input shaft 17 is mounted on the inner side of the split reduction gearbox housing assembly 2 through the input shaft mounting bearing;

[0057] like Figure 1 and Figure 3 As shown, the spur gear reduction gear assembly 4 is arranged directly above the differential assembly 1, and is composed of a first spur gear 12, a second spur gear 13, a second spur gear shaft 14 and a third spur gear 19. As mentioned above, the first spur gear 12 is coaxially fixedly connected to the housing of the differential assembly 1, and the second spur gear shaft 14 is arranged in parallel below the input shaft 17 of the input shaft assembly 5, and its two ends are supported and installed on the separate reduction gear housing assembly 2; the second spur gear 13 is loosely sleeved on the second spur gear shaft 14 through the first copper sleeve 15, wherein the first copper sleeve 15 and the second spur gear 13 are interference fit, and the first copper sleeve 15 and the second spur gear shaft 14 are transition fit; the second spur gear 13 is meshed with the first spur gear 12 below it; directly above the second spur gear 13, the The rotating sleeve of the second planetary carrier 18 of the planetary gear reduction assembly 6 is loosely sleeved on the left end of the input shaft 17 of the input shaft assembly 5 through the second copper sleeve 16, and the third spur gear 19 is splined on the outer circumferential surface of the rotating sleeve of the second planetary carrier 18 to achieve torque transmission; the third spur gear 19 is meshed with the second spur gear 13 therebelow; the third spur gear 19 and the second spur gear 13 are in a constant ratio transmission, the purpose of which is to increase the radial distance between the gears, and the transmission ratio i of the second spur gear 13 and the first spur gear 12 is greater than 1, the purpose of which is to reduce the output speed and increase the output torque.

[0058] like Figure 1 and Figure 4 As shown, the planetary gear reduction assembly 6 is arranged on the right side of the spur gear reduction assembly 4, and includes a first planetary transmission gear train consisting of a first sun gear 20a, a first planetary gear 22a, a first planetary carrier 23 and a first outer ring 26, and a second planetary gear train consisting of a second sun gear 20b, a second planetary gear 22b, a second planetary carrier 18 and a second outer ring 25.

[0059] In the second planetary gear system, the input shaft 17 passes through the second planetary carrier 18 along the axial direction, the rotating sleeve of the left end of the second planetary carrier 18 is sleeved on the left end of the input shaft 17, and a spline matching the third spur gear 19 is provided on the outer circumferential surface of the rotating sleeve of the second planetary carrier 18; in addition, the outer circumferential surface of the rotating sleeve of the second planetary carrier 18 is also rotatably mounted with the split reduction box housing assembly 2 through a bearing; the right end of the second planetary carrier 18 is the second planetary gear shaft carrier, and the second planetary gear 22b is sleeved on each short shaft of the second planetary gear shaft carrier through a fourth copper sleeve 24b; the second sun gear 20b is connected to the input shaft 17 It is set as an integrated structure, that is, the input shaft 17 is designed as a gear shaft structure to reduce the difficulty of assembly, and the gear on it serves as the second sun gear 20b in the second planetary gear system, and the second sun gear 20b is respectively meshed with the second planetary gear 22b on the outer side of the circumference; the second outer ring 25 is arranged on the outer side of the second planetary gear 22b, and the inner circumferential wall of the second outer ring 25 is provided with gear teeth meshed with the second planetary gear 22b, one end of the second outer ring 25 is sleeved on the convex edge at the corresponding position of the split reduction box housing assembly 2, and the outer circumferential surface of the second outer ring 25 is coaxially fixedly connected with the third friction plate 28c of the third clutch assembly 9;

[0060] In the first planetary gear system, the first sun gear 20a is installed on the input shaft 17 through a flat key 21; the first planetary gear 22a is loosely sleeved on each short shaft of the first planetary carrier 23 outside the first sun gear 20a through a third copper sleeve 24a; the first planetary carrier 23 and the second outer ring 25 in the second planetary gear system are designed as an integral structure to ensure that the first planetary carrier 23 and the second outer ring 25 rotate synchronously; the first sun gear 20a is meshed with the first planetary gear 22a on the outer side of the circumference; the first outer ring 26 is arranged on the outer side of the first planetary gear 22a, and the inner circumferential wall of the first outer ring 26 is provided with gear teeth meshing with the first planetary gear 22a, one end of the first outer ring 26 is installed in a groove at a corresponding position of the split reduction box housing assembly 2, and the outer circumferential surface of the left end of the first outer ring 26 is coaxially fixedly connected with the second friction plate 28b of the second clutch assembly 8.

[0061] like Figure 1 and Figure 5 As shown, the electric drive axle assembly of the present invention is provided with three clutch assemblies, namely the first clutch assembly 7, the second clutch assembly 8 and the third clutch assembly 9, wherein each clutch assembly is composed of a spring, a friction plate, a piston and a steel plate;

[0062] In the third clutch assembly 9, the third friction plate 28c is coaxially fixed on the outer circumferential surface of the second outer ring 25, the third steel plate 30c is matched with the third friction plate 28c and is mounted on the inner wall of the split reduction box housing assembly 2, a relatively closed third hydraulic cavity is formed between the left end surface of the third piston 29c and the side wall of the split reduction box housing assembly 2, a third hydraulic oil port is opened on the split reduction box housing assembly 2 corresponding to the third hydraulic cavity, the third piston 29c is a diaphragm spring, and the third spring 27c is mounted on the third piston. The third piston 29c is between the third steel plate 30c on the far left; when the pressure in the third hydraulic chamber increases, the third piston 29c squeezes the third steel plate 30c and combines with the third friction plate 28c, thereby making the second outer ring 25 engage and fix with the side wall of the split reduction gearbox housing assembly 2; when the pressure in the third hydraulic chamber drops to zero, under the action of the restoring force of the third spring 27c, the third steel plate 30c and the third friction plate 28c are separated and restored to their original positions, and at this time, the second outer ring 25 is also separated from the side wall of the split reduction gearbox housing assembly 2;

[0063] In the second clutch assembly 8, the second friction plate 28b is coaxially fixed on the outer circumferential surface of the first outer ring 26, the second steel plate 30b is matched with the second friction plate 28b and is mounted on the inner wall of the split reduction gearbox housing assembly 2, a relatively closed second hydraulic cavity is formed between the right end surface of the second piston 29b and the side wall of the split reduction gearbox housing assembly 2, a second hydraulic oil port is opened on the split reduction gearbox housing assembly 2 corresponding to the second hydraulic cavity, the second piston 29b is a diaphragm spring, and the second spring 27b is mounted on the second piston 29b. The piston 29b is between the second steel plate 30b on the far right; when the pressure in the second hydraulic chamber increases, the second piston 29b squeezes the second steel plate 30b and combines with the second friction plate 28b, thereby making the first outer ring 26 engage and fix with the side wall of the split reduction gearbox housing assembly 2; when the pressure in the second hydraulic chamber drops to zero, under the action of the restoring force of the second spring 27b, the second steel plate 30b and the second friction plate 28b are separated and restored to their original positions, and at this time, the first outer ring 26 is also separated from the side wall of the split reduction gearbox housing assembly 2;

[0064] In the first clutch assembly 7, the first friction plate 28a is coaxially mounted on the first clutch support frame 32, the first clutch support frame 32 is coaxially arranged at the right end of the first outer ring 26, and the inner ring of the first clutch support frame 32 is coaxially connected to the input shaft 17 through a spline; the first steel plate 30a and the first friction plate 28a are matched and mounted on the inner circumferential wall of the right end of the first outer ring 26, a relatively closed first hydraulic cavity is formed between the right end face of the first piston 29a and the side wall of the split reduction gearbox housing assembly 2, a first hydraulic oil port is opened on the split reduction gearbox housing assembly 2 corresponding to the first hydraulic cavity, the outer ring of the first piston 29a is matched and mounted with the split reduction gearbox housing assembly 2, the inner ring of the first piston 29a and the input shaft 17 are transitionally matched, the first spring 27a is a coil spring, and the first spring 27a is mounted on In the annular groove at the right end of the first clutch support frame 32, one end of the first spring 27a is connected to the bottom of the annular groove of the first clutch support frame 32, and the other end is connected to the middle of the left end surface of the first piston 29a. A circle of pressure plate is provided on the outer circumference of the left end surface of the first piston 29a, and the pressure plate corresponds to the first steel plate 30a on the far right; when the pressure in the first hydraulic chamber increases, the first piston 29a squeezes the first steel plate 30a and combines with the first friction plate 28a, so that the first outer ring 26 is engaged and fixed with the first clutch support frame, and then the first outer ring 26 is engaged and fixed with the input shaft 17. When the pressure in the first hydraulic chamber drops to zero, under the action of the restoring force of the first spring 27a, the first steel plate 30a and the first friction plate 28a are separated and restored to their original positions. At this time, the first outer ring 26 is also separated from the input shaft 17.

[0065] The friction plates and steel plates in the first clutch assembly 7, the second clutch assembly 8 and the third clutch assembly 9 are lubricated with lubricating oil, and the lubricating oil channels in the first clutch assembly 7, the second clutch assembly 8 and the third clutch assembly 9 are connected to the lubricating oil channels of the planetary gear reduction assembly 6, so as to reduce the number of parts and components, increase the convenience of assembly, and improve the assembly accuracy.

[0066] like Figure 1 and Figure 6 As shown, the split reduction gearbox housing assembly 2 is composed of a first reduction gearbox housing 31a, a second reduction gearbox housing 31b and a third reduction gearbox housing 31c which are bolted together in sequence from left to right. The gaps between the first reduction gearbox housing 31a and the second reduction gearbox housing 31b and between the second reduction gearbox housing 31b and the third reduction gearbox housing 31c are sealed with sealing tape or sealant. The split reduction gearbox structure reduces the difficulty of assembly and provides more possibilities for the design of the reduction gearbox housing.

[0067] like Figure 1As shown, the reduction gearbox end cover assembly 3 is composed of a plurality of reduction gearbox end covers, which are fixedly mounted at the openings at the left and right ends of the separate reduction gearbox housing assembly 2 by screws, thereby encapsulating the separate reduction gearbox housing assembly 2.

[0068] The three-speed light-weight electric drive axle assembly of the present invention has three transmission gears: direct gear, medium speed gear and low speed gear. The specific working process under each gear is as follows:

[0069] When the pressure oil enters the first hydraulic cavity from the first hydraulic oil port in the first clutch assembly 7, the pressure in the first hydraulic cavity increases, pushing the first piston 29a to squeeze the first steel plate 30a to make it combine with the first friction plate 28a, and the first clutch assembly 7 starts to work. At this time, the input shaft 17 is combined and fixed with the first outer ring 26, and the two maintain the same speed, that is, the first sun gear 20a coaxially connected to the input shaft 17 and the first outer ring 26 maintain the same speed. According to the transmission characteristics of the planetary gear system, at this time, the first planet carrier 23 and the input shaft 1 7 maintains the same speed, that is, the second outer ring 25 coaxially connected to the first planet carrier 23 maintains the same speed as the input shaft 17. Similarly, the second planet carrier 18 maintains the same speed as the input shaft 17, that is, the planetary gear reduction assembly 6 does not assume the reduction function. At this time, the electric drive axle assembly is in direct gear, and the power is transmitted from the input shaft 17 to the first planet carrier 23, the second planet carrier 18, the third spur gear 19, the second spur gear 13 and the first spur gear 12 in sequence, and then transmitted from the first spur gear 12 to the output of the differential assembly through the coupling screw 11.

[0070] When the pressure oil enters the second hydraulic cavity from the second hydraulic oil port in the second clutch assembly 8, the pressure in the second hydraulic cavity increases, pushing the second piston 29b to squeeze the second steel plate 30b so that it engages with the second friction plate 30b, and the second clutch assembly 8 starts to work. At this time, the first outer ring 26 engages with the second reduction gearbox housing 31b, and the second reduction gearbox housing 31b is fixed, so the rotation speed of the first outer ring 26 is zero. Assuming that the ratio of the number of teeth of the first outer ring 26 and the first planetary gear 22a is p1, the ratio of the second outer ring and the second planetary gear 22b is p2, and the rotational speed of the input shaft 17 is 1, it can be obtained that: the rotational speed of the first planetary carrier 23 is 1 / (1+p1), that is, the rotational speed of the second outer ring 25 coaxially connected to the first planetary carrier 23 is 1 / (1+p1), and the rotational speed of the second sun gear 20b integrated with the input shaft 17 is 1, so the rotational speed of the second planetary carrier 18 is 1 / (1+p2)+p2 / [(1+p2)(1+p1)]. Therefore, at this time, the electric drive axle assembly is in the middle speed gear, and the power is transmitted from the input shaft 17 to the first planetary carrier 23, the second planetary carrier 18, the third spur gear 19, the second spur gear 13 and the first spur gear 12 in sequence, and then transmitted to the output of the differential assembly by the first spur gear 12 through the coupling screw 11.

[0071] When the pressure oil enters the third hydraulic cavity from the third hydraulic oil port in the third clutch assembly 9, the pressure in the third hydraulic cavity increases, pushing the third piston 29c to squeeze the third steel plate 30c to make it combine with the third friction plate 28c, and the clutch assembly 9 starts to work. At this time, the second outer ring 25 is engaged with the first reduction box housing 31a, and the first reduction box housing 31a is fixed, so the speed of the second outer ring 25 is zero. Assuming that the ratio of the second outer ring 25 to the second planetary gear 22b is p2, the speed of the input shaft 17 is 1, that is, the speed of the second sun gear 20b integrated with the input shaft 17 is 1, so the speed of the second planetary carrier 18 is 1 / (1+p2), so at this time the electric drive axle assembly is in low gear, and the power is transmitted from the input shaft 17 to the second planetary carrier 18, the third spur gear 19, the second spur gear 13, and the first spur gear 12 in sequence, and then transmitted from the first spur gear 12 to the differential assembly output through the coupling screw 11.

Claims

1. Three-speed light-weight electric drive axle assembly, characterized by: It consists of a differential assembly (1), a split-type reduction gearbox housing assembly (2), a reduction gearbox end cover assembly (3), a spur gear reduction gear assembly (4), an input shaft assembly (5), a planetary gear reduction assembly (6) and three sets of clutch assemblies; The housing of the differential assembly (1) is coaxially fixedly connected to the first spur gear (12) of the upper spur gear reduction gear assembly (4); In the spur gear reduction gear assembly (4), the first spur gear (12), the second spur gear (13) and the third spur gear (19) are meshed and connected in sequence, the third spur gear (19) is coaxially fixedly connected to the rotating shaft sleeve of the second planet carrier (18) in the planetary gear reduction gear assembly (6), and the rotating shaft sleeve of the second planet carrier (18) is loosely sleeved on the input shaft (17) of the spur gear reduction gear assembly (4); The planetary gear reduction assembly (6) is composed of two sets of planetary gear trains arranged axially along the input shaft (17), wherein the second sun gear (20b) and the first sun gear (20a) are coaxially fixed on the input shaft (17) in sequence, and the second outer ring (25) is coaxially fixedly connected to the first planet carrier (23); In the first clutch (7), the first clutch support frame (32) is coaxially fixed to the input shaft (17), the first friction plate (28a) is coaxially mounted on the first clutch support frame (32), the first steel plate (30a) and the first friction plate (28a) are matched and mounted on the inner circumferential wall of the first outer ring (26), and the separation or combination of the first friction plate (28a) and the first steel plate (30a) is controlled to control the separation or combination of the first outer ring (26) and the input shaft (17); In the second clutch (8), the second friction plate (28b) is coaxially fixed to the outer circumferential surface of the first outer ring (26), and the second steel plate (30b) is matched with the second friction plate (28b) and mounted on the inner wall of the split reduction gearbox housing assembly (2). By controlling the separation or combination of the second friction plate (28b) and the second steel plate (30b), the separation or combination of the first outer ring (26) and the split reduction gearbox housing assembly (2) is controlled; In the third clutch (9), the third friction plate (28c) is coaxially fixed to the outer circumferential surface of the second outer ring (25), and the third steel plate (30c) is matched with the third friction plate (28c) and mounted on the inner wall of the split reduction gearbox housing assembly (2). By controlling the separation or combination of the third friction plate (28c) and the third steel plate (30c), the separation or combination of the second outer ring (25) and the split reduction gearbox housing assembly (2) is controlled; In the first clutch assembly (7), a first hydraulic cavity is formed between the first piston (29a) and the side wall of the split reduction gearbox housing assembly (2), a first hydraulic oil port is opened on the split reduction gearbox housing assembly (2) corresponding to the first hydraulic cavity, the outer ring of the first piston (29a) is matched and installed with the split reduction gearbox housing assembly (2), the inner ring of the first piston (29a) is matched and connected with the input shaft (17), the first spring (27a) is installed in the annular groove on the end face of the first clutch support frame (32), one end of the first spring (27a) is connected to the bottom of the annular groove of the first clutch support frame (32), the other end of the first spring (27a) is connected to the end face of the first piston (29a), and a circle of pressure plate is provided on the outer circumference of the end face of the first piston (29a), and the pressure plate corresponds to the first steel plate (30a) and the first friction plate (28a); When the pressure in the first hydraulic chamber increases, the first piston (29a) squeezes the first steel plate (30a) and the first friction plate (28a) to combine, so that the first outer ring (26) is engaged and fixed with the first clutch support frame, and then the first outer ring (26) is engaged and fixed with the input shaft (17); when the pressure in the first hydraulic chamber decreases to zero, under the action of the restoring force of the first spring (27a), the first steel plate (30a) and the first friction plate (28a) are separated and restored to their original positions, and at this time, the first outer ring (26) and the input shaft (17) are also separated; In the second clutch assembly (8), a second hydraulic cavity is formed between the second piston (29b) and the side wall of the split reduction gearbox housing assembly (2), a second hydraulic oil port is opened on the split reduction gearbox housing assembly (2) corresponding to the second hydraulic cavity, and a second spring (27b) is installed between the second piston (29b) and the second steel sheet (30b); When the pressure in the second hydraulic chamber increases, the second piston (29b) squeezes the second steel plate (30b) and combines with the second friction plate (28b), thereby making the first outer ring (26) engage and fix with the side wall of the split reduction gearbox housing assembly (2); when the pressure in the second hydraulic chamber decreases to zero, under the action of the restoring force of the second spring (27b), the second steel plate (30b) and the second friction plate (28b) separate and return to their original positions, and at this time, the first outer ring (26) and the side wall of the split reduction gearbox housing assembly (2) are also separated; In the third clutch (9), a third hydraulic cavity is formed between the third piston (29c) and the side wall of the split reduction gearbox housing assembly (2), a third hydraulic oil port is opened on the split reduction gearbox housing assembly (2) corresponding to the third hydraulic cavity, and a third spring (27c) is installed between the third piston (29c) and the third steel sheet (30c); When the pressure in the third hydraulic chamber increases, the third piston (29c) squeezes the third steel plate (30c) and the third friction plate (28c) to combine, thereby causing the second outer ring (25) to engage and fix with the side wall of the split reduction gearbox housing assembly (2); when the pressure in the third hydraulic chamber decreases to zero, under the action of the restoring force of the third spring (27c), the third steel plate (30c) and the third friction plate (28c) are separated and restored to their original positions, and at this time, the second outer ring (25) and the side wall of the split reduction gearbox housing assembly (2) are also separated; The friction plates and steel plates in the first clutch assembly (7), the second clutch assembly (8) and the third clutch assembly (9) are lubricated with lubricating oil, and the lubricating oil passages in the first clutch assembly (7), the second clutch assembly (8) and the third clutch assembly (9) are connected to the lubricating oil passages of the planetary gear reduction assembly (6); The three-speed light-weight electric drive axle assembly has three transmission gears: direct gear, medium speed gear and low speed gear. The specific working process under each gear is as follows: When the pressure oil enters the first hydraulic cavity from the first hydraulic oil port in the first clutch assembly (7), the pressure in the first hydraulic cavity increases, pushing the first piston (29a) to squeeze the first steel plate (30a) so that it is combined with the first friction plate (28a), and the first clutch assembly (7) starts to work. At this time, the input shaft (17) and the first outer ring (26) are combined and fixed, and the two maintain the same rotation speed, that is, the first sun gear (20a) coaxially fixed to the input shaft (17) and the first outer ring (26) maintain the same rotation speed. According to the transmission characteristics of the planetary gear system, at this time, the first planet carrier (23) and the input shaft (17) maintain The first planetary carrier (23) and the second planetary carrier (18) are coaxially connected to each other ... When the pressure oil enters the second hydraulic cavity from the second hydraulic oil port in the second clutch assembly (8), the pressure in the second hydraulic cavity increases, pushing the second piston (29b) to squeeze the second steel plate (30b) so that it engages with the second friction plate (30b), and the second clutch assembly (8) starts to work. At this time, the first outer ring (26) engages with the second reduction box housing (31b), and the second reduction box housing (31b) is fixed, so the rotation speed of the first outer ring (26) is zero; assuming that the ratio of the number of teeth of the first outer ring (26) and the first planetary gear (22a) is p1, the ratio of the second outer ring and the second planetary gear (22b) is p2, and the rotation speed of the input shaft (17) is 1, it can be obtained that: ) is 1 / (1+p1), that is, the rotation speed of the second outer ring (25) coaxially connected to the first planet carrier (23) is 1 / (1+p1), and the rotation speed of the second sun gear (20b) integrated with the input shaft (17) is 1, so the rotation speed of the second planet carrier (18) is 1 / (1+p2)+p2 / [(1+p2)(1+p1)], so at this time the electric drive axle assembly is in the middle speed gear, and the power is transmitted from the input shaft (17) to the first planet carrier (23), the second planet carrier (18), the third spur gear (19), the second spur gear (13) and the first spur gear (12) in sequence, and then transmitted from the first spur gear (12) to the output of the differential assembly through the coupling screw (11); When the pressure oil enters the third hydraulic cavity from the third hydraulic oil port in the third clutch assembly (9), the pressure in the third hydraulic cavity increases, pushing the third piston (29c) to squeeze the third steel plate (30c) so that it is combined with the third friction plate (28c), and the clutch assembly (9) starts to work. At this time, the second outer ring (25) is engaged with the first reduction box housing (31a), and the first reduction box housing (31a) is fixed, so the rotation speed of the second outer ring (25) is zero; assuming that the second outer ring (25) and the second planetary gear (22b ) is p2, the rotation speed of the input shaft (17) is 1, that is, the rotation speed of the second sun gear (20b) integrated with the input shaft (17) is 1, so the rotation speed of the second planetary carrier (18) is 1 / (1+p2), so at this time the electric drive axle assembly is in low gear, and the power is transmitted from the input shaft (17) to the second planetary carrier (18), the third spur gear (19), the second spur gear (13), and the first spur gear (12) in sequence, and then transmitted from the first spur gear (12) to the output of the differential assembly through the coupling screw (11); The three-speed light-weight electric drive axle assembly adopts three sets of clutch assemblies, and realizes the three gear changes of direct gear, medium speed gear and low speed gear of the electric vehicle by controlling the engagement or separation of each clutch assembly; The spur gear reduction gear assembly (4) is arranged directly above the differential assembly (1), and is composed of a first spur gear (12), a second spur gear (13), a second spur gear shaft (14) and a third spur gear (19); the first spur gear (12) is coaxially fixedly connected to the housing of the differential assembly (1); the second spur gear shaft (14) is arranged in parallel below the input shaft (17) of the input shaft assembly (5), and its two ends are supported and mounted on the split reduction box housing assembly (2); the second spur gear (13) is loosely sleeved on the second spur gear shaft (14) through a first copper sleeve (15), wherein the first copper sleeve (15) and the second spur gear (13) are interference fit, and the first copper sleeve (15) and the second spur gear shaft (14) are transition fit; the second spur gear (13) is loosely sleeved on the second spur gear shaft (14) through a first copper sleeve (15), wherein the first copper sleeve (15) and the second spur gear (13) are interference fit, and the first copper sleeve (15) and the second spur gear shaft (14) are transition fit; the second spur gear (13) is loosely sleeved on the second spur gear shaft (14), and the first copper sleeve (15) and the second spur gear shaft (14) are transition fit. ) is meshed with the first spur gear (12) below it; at a position directly above the second spur gear (13), the rotating sleeve of the second planetary carrier (18) of the planetary gear reduction assembly (6) is loosely sleeved on the left end of the input shaft (17) of the input shaft assembly (5) through the second copper sleeve (16), and the third spur gear (19) is sleeved on the outer circumferential surface of the rotating sleeve of the second planetary carrier (18) through a spline to achieve torque transmission; the third spur gear (19) is meshed with the second spur gear (13) below it; the third spur gear (19) and the second spur gear (13) are in equal ratio transmission, the purpose of which is to increase the radial distance between the gears; the transmission ratio i of the second spur gear (13) and the first spur gear (12) is greater than 1, the purpose of which is to reduce the output speed and increase the output torque; The planetary gear reduction assembly (6) is arranged on the right side of the spur gear reduction assembly (4), and comprises a first planetary transmission gear train consisting of a first sun gear (20a), a first planetary gear (22a), a first planetary carrier (23) and a first outer ring (26), and a second planetary gear train consisting of a second sun gear (20b), a second planetary gear (22b), a second planetary carrier (18) and a second outer ring (25); In the second planetary gear system, the input shaft (17) passes through the second planetary carrier (18) along the axial direction, the rotating sleeve of the left end of the second planetary carrier (18) is loosely sleeved on the left end of the input shaft (17), and a spline matching the third spur gear (19) is provided on the outer circumferential surface of the rotating sleeve of the second planetary carrier (18); in addition, the outer circumferential surface of the rotating sleeve of the second planetary carrier (18) is also rotatably mounted with the split reduction box housing assembly (2) through a bearing; the right end of the second planetary carrier (18) is a second planetary wheel shaft frame, and the second planetary wheels (22b) are loosely sleeved on the short shafts of the second planetary wheel shaft frame through fourth copper sleeves (24b); the second sun gear (20b) is connected to the input shaft (17) The structure is set as an integrated structure, that is, the input shaft (17) is designed as a gear shaft structure to reduce the difficulty of assembly, and the gear on it serves as the second sun gear (20b) in the second planetary gear system, and the second sun gear (20b) is respectively meshed with the second planetary gear (22b) on the outer side of the circumference; the second outer ring (25) is arranged on the outer side of the second planetary gear (22b), and the inner circumferential wall of the second outer ring (25) is provided with gear teeth meshed with the second planetary gear (22b), one end of the second outer ring (25) is sleeved on the convex edge at the corresponding position of the split reduction box housing assembly (2), and the outer circumferential surface of the second outer ring (25) is coaxially fixedly connected with the third friction plate (28c) of the third clutch assembly (9); In the first planetary gear system, the first sun gear (20a) is installed on the input shaft (17) through a flat key (21); the first planetary gear (22a) is loosely sleeved on each short shaft of the first planetary carrier (23) outside the first sun gear (20a) through a third copper sleeve (24a); the first planetary carrier (23) and the second outer ring (25) in the second planetary gear system are designed as an integrated structure to ensure that the first planetary carrier (23) and the second outer ring (25) rotate synchronously; the first sun gear (20 a) meshing with the first planetary gear (22a) on the outer side of the circumference; the first outer ring (26) is arranged on the outer side of the first planetary gear (22a), and the inner circumferential wall of the first outer ring (26) is provided with gear teeth meshing with the first planetary gear (22a); one end of the first outer ring (26) is installed in a groove at a corresponding position of the split reduction gearbox housing assembly (2), and the outer circumferential surface of the left end of the first outer ring (26) is coaxially fixedly connected with the second friction plate (28b) of the second clutch assembly (8); The electric drive axle assembly is provided with three clutch assemblies, namely a first clutch assembly 7, a second clutch assembly (8) and a third clutch assembly (9), wherein each clutch assembly is composed of a spring, a friction plate, a piston and a steel plate; In the third clutch assembly (9), the third friction plate (28c) is coaxially fixed on the outer circumferential surface of the second outer ring (25), the third steel plate (30c) and the third friction plate (28c) are matched and mounted on the inner wall of the split reduction gearbox housing assembly (2), a relatively closed third hydraulic cavity is formed between the left end surface of the third piston (29c) and the side wall of the split reduction gearbox housing assembly (2), a third hydraulic oil port is opened on the split reduction gearbox housing assembly (2) corresponding to the third hydraulic cavity, the third piston (29c) is a diaphragm spring, and the third spring (27c) is mounted on the third piston (29c) and the third steel plate (30c) on the far left; when the pressure in the third hydraulic chamber increases, the third piston (29c) squeezes the third steel plate (30c) and combines it with the third friction plate (28c), thereby making the second outer ring (25) engage and fix with the side wall of the split reduction gearbox housing assembly (2); when the pressure in the third hydraulic chamber drops to zero, under the action of the restoring force of the third spring (27c), the third steel plate (30c) and the third friction plate (28c) are separated and restored to their original positions, and at this time, the second outer ring (25) and the side wall of the split reduction gearbox housing assembly (2) are also separated; In the second clutch assembly (8), the second friction plate (28b) is coaxially fixed on the outer circumferential surface of the first outer ring (26), the second steel plate (30b) is matched with the second friction plate (28b) and is mounted on the inner wall of the split reduction gearbox housing assembly (2), a relatively closed second hydraulic cavity is formed between the right end surface of the second piston (29b) and the side wall of the split reduction gearbox housing assembly (2), a second hydraulic oil port is opened on the split reduction gearbox housing assembly (2) corresponding to the second hydraulic cavity, the second piston (29b) is a diaphragm spring, and the second spring (27b) is mounted on the second piston (29b) and the second steel plate (30b) on the far right; when the pressure in the second hydraulic chamber increases, the second piston (29b) squeezes the second steel plate (30b) and combines it with the second friction plate (28b), thereby making the first outer ring (26) engage and fix with the side wall of the split reduction gearbox housing assembly (2); when the pressure in the second hydraulic chamber drops to zero, under the action of the restoring force of the second spring (27b), the second steel plate (30b) and the second friction plate (28b) separate and return to their original positions, and at this time, the first outer ring (26) and the side wall of the split reduction gearbox housing assembly (2) are also separated; In the first clutch assembly (7), the first friction plate (28a) is coaxially mounted on the first clutch support frame (32), the first clutch support frame (32) is coaxially arranged at the right end of the first outer ring (26), and the inner ring of the first clutch support frame (32) is coaxially connected to the input shaft (17) through a spline; the first steel plate (30a) and the first friction plate (28a) are matched and mounted on the inner circumferential wall of the right end of the first outer ring (26), a relatively closed first hydraulic cavity is formed between the right end surface of the first piston (29a) and the side wall of the split reduction gearbox housing assembly (2), and the split reduction gearbox housing assembly corresponding to the first hydraulic cavity is (2) is provided with a first hydraulic oil port, the outer ring of the first piston (29a) is matched and installed with the split reduction gearbox housing assembly (2), the inner ring of the first piston (29a) and the input shaft (17) are transitionally matched, the first spring (27a) is a coil spring, the first spring (27a) is installed in the annular groove at the right end of the first clutch support frame (32), one end of the first spring (27a) is connected to the bottom of the annular groove of the first clutch support frame (32), and the other end is connected to the middle of the left end face of the first piston 29a, and a circle of pressure plate is provided on the outer circumference of the left end face of the first piston (29a), and the pressure plate corresponds to the first steel plate (30a) on the far right; When the pressure in the first hydraulic chamber increases, the first piston (29a) squeezes the first steel plate (30a) and the first friction plate (28a) to combine, so that the first outer ring (26) is engaged and fixed with the first clutch support frame, and then the first outer ring (26) is engaged and fixed with the input shaft (17); when the pressure in the first hydraulic chamber decreases to zero, under the action of the restoring force of the first spring (27a), the first steel plate (30a) and the first friction plate (28a) are separated and restored to their original positions, and at this time, the first outer ring (26) and the input shaft (17) are also separated; The friction plates and steel plates in the first clutch assembly (7), the second clutch assembly (8) and the third clutch assembly (9) are lubricated with lubricating oil, and the lubricating oil passages in the first clutch assembly (7), the second clutch assembly (8) and the third clutch assembly (9) are connected to the lubricating oil passages of the planetary gear reduction assembly (6), so as to reduce the number of parts and components, increase the convenience of assembly and improve the assembly accuracy.

2. The three-speed light-weight electric drive axle assembly as claimed in claim 1, characterized in that: In the spur gear reduction gear assembly (4), the second spur gear (13) is loosely sleeved on the second spur gear shaft (14) through the first copper sleeve (15); the second spur gear shaft (14) is arranged in parallel below the input shaft (17) of the input shaft assembly (5); and both ends of the second spur gear shaft (14) are respectively mounted on the separate reduction gearbox housing assembly (2); The third spur gear (19) and the second spur gear (13) are in equal ratio transmission, and the transmission ratio of the second spur gear (13) to the first spur gear (12) is greater than (1).

3. The three-speed light-weight electric drive axle assembly as claimed in claim 1, characterized in that: In the planetary gear reduction assembly (6), the first planetary gear train is composed of a first sun gear (20a), a first planetary gear (22a), a first planet carrier (23) and a first outer ring (26); The first sun gear (20a) is mounted on the input shaft (17) via a flat key (21); the first planetary gears (22a) are loosely mounted on the short shafts of the planetary gear shaft frame of the first planetary carrier (23) via third copper sleeves (24a); the first planetary carrier (23) and the second outer ring (25) in the second planetary gear system are an integrally formed structure; the first planetary gear (22a) is meshed with the first sun gear (20a) and the first outer ring (26) respectively; one end of the first outer ring (26) is mounted in a groove of the split reduction gearbox housing assembly (2).

4. The three-speed light-weight electric drive axle assembly as claimed in claim 1, characterized in that: In the planetary gear reduction assembly (6), the second planetary gear train is composed of a second sun gear (20b), a second planetary gear (22b), a second planet carrier (18) and a second outer ring (25); The second planet carrier (18) is coaxially mounted on the input shaft (17); the rotating sleeve of the second planet carrier (18) is loosely sleeved on the input shaft (17) via a second copper sleeve (16); the outer side of the rotating sleeve of the second planet carrier (18) is connected to the third spur gear (19) via a spline; the second planetary gears (22b) are loosely sleeved on the short shafts of the planetary gear shaft frame of the second planet carrier (18) via fourth copper sleeves (24b); the second sun gear (20b) and the input shaft (17) are arranged as an integrated structure; the second planetary gears (22b) are meshed with the second sun gear (20b) and the second outer ring (25) respectively; one end of the second outer ring (25) is sleeved on a convex edge at a corresponding position of the split reduction gearbox housing assembly (2).

5. The three-speed light-weight electric drive axle assembly as claimed in claim 1, characterized in that: The split reduction gearbox housing assembly (2) is composed of a first reduction gearbox housing (31a), a second reduction gearbox housing (31b) and a third reduction gearbox housing (31c) which are bolted together in sequence from left to right, and the gaps between the first reduction gearbox housing (31a) and the second reduction gearbox housing (31b) and between the second reduction gearbox housing (31b) and the third reduction gearbox housing (31c) are sealed with sealing tape or sealing glue.

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