Differential structure of high-rotating-speed electric drive axle

Abstract

The utility model discloses a differential structure of a high-rotating-speed electric drive axle, which is characterized in that two axle housings are respectively fixed on two sides of a motor, and two groups of hub assemblies are respectively arranged on the two axle housings; an input shaft is rotatably mounted in the axle housing, and the brake assembly is arranged between the axle housing and the input shaft; the differential mechanism is rotationally installed in one axle housing, a motor shaft of the motor is in transmission connection with the differential mechanism, the differential mechanism is in transmission connection with the two input shafts, the rotating shaft penetrates through the motor shaft, the differential mechanism transmits power of the motor to the two input shafts, and the two input shafts are in transmission connection with the two hub assemblies respectively; one end of the differential is connected with the axle housing through a first high-speed bearing, and the other end of the differential is connected with the axle housing through a second high-speed bearing. The structure can adapt to the use of a 10000 r / min high-speed motor, the noise can be effectively reduced, the motor can realize higher power density, the energy consumption is effectively reduced, and the cruising ability of the whole vehicle is improved.

Description

Technical Field

[0001] The utility model relates to the field of drive axles, in particular to a differential structure of a high-speed electric drive axle. Background Art

[0002] With the development of China's logistics economy, forklifts are more widely used, and the design and manufacture of forklift transmission components have gradually matured. Forklifts tend to develop in the new energy direction, and transmission components also tend to be integrated in design. The performance of motors has been comprehensively improved, and forklifts are also developing in the direction of improving energy utilization efficiency and increasing cruising range.

[0003] The prior art with the publication number of CN220764062U discloses a forklift electric drive axle assembly, including a motor, a differential, a brake assembly and a hub assembly; both ends of the motor are fixed with axle housings, an input shaft is rotatably installed in the axle housings, two groups of brake assemblies are respectively installed in the two axle housings, and the brake assembly is arranged between the axle housing and the input shaft for braking the input shaft; the hub assembly includes a reducer housing, and a sun gear shaft, a planetary reduction structure and an output shaft rotatably installed on the reducer housing; the differential is rotatably installed in one axle housing, and the differential transmits the power input by the motor to the two input shafts respectively; the reducer housing is fixedly connected to the adjacent axle housing, and the sun gear shaft is in transmission connection with the input shaft and transmits the power to the output shaft. Among them, the differential is rotatably installed on the bearing seat through a second bearing, the bearing seat is tightly fitted with the axle housing, one end of the bearing seat abuts against the motor, and the other end of the bearing seat is clamped with a third snap ring on the axle housing.

[0004] In the prior art, the differential is only rotatably installed in the axle housing through a large bearing, which leads to problems such as greater noise, larger vibration and higher energy consumption and poorer endurance of the drive axle when a high-speed motor is used to drive the differential. Summary of the Invention

[0005] In order to solve the problems of large noise and poor endurance of the drive axle caused by the differential being installed in the axle housing through a first bearing in the prior art, the purpose of the utility model is to provide a differential structure of a high-speed electric drive axle, in which the differential is installed in the axle housing through two bearings, so that the differential can be more matched with a high-speed motor, and the endurance of the drive axle can be effectively improved.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions: a differential structure of a high-speed electric drive axle, including a motor, an axle housing, a differential, a brake assembly and two groups of hub assemblies;

[0007] Two axle housings are respectively fixed on both sides of the motor, and two groups of hub assemblies are respectively installed on the two axle housings; an input shaft is rotatably installed in the axle housing, and the brake assembly is arranged between the axle housing and the input shaft;

[0008] The differential is rotatably installed in a axle housing. The motor shaft of the motor is drivingly connected to the differential. One output end of the differential is drivingly connected to an input shaft, and the other output end of the differential is drivingly connected to another input shaft through a rotating shaft. The rotating shaft passes through the motor shaft. The differential transmits the power of the motor to the two input shafts respectively, and the two input shafts are respectively drivingly connected to the two hub assemblies.

[0009] One end of the differential is connected to the axle housing through a first high-speed bearing, and the other end of the differential is connected to the axle housing through a second high-speed bearing.

[0010] Preferably, the differential includes a differential housing, a cross shaft, a left half shaft gear, a right half shaft gear and a star gear. The differential housing is rotatably installed in the axle housing through a first high-speed bearing and a second high-speed bearing. The cross shaft is fixed in the differential housing. The star gear is installed on the cross shaft. The left half shaft gear and the right half shaft gear are respectively arranged on both sides of the cross shaft. The left half shaft gear and the right half shaft gear are rotationally matched with the differential housing, and both the left half shaft gear and the right half shaft gear are engaged with the star gear. The right half shaft gear is drivingly connected to an input shaft, and the left half shaft gear is drivingly connected to another input shaft through a rotating shaft.

[0011] Preferably, the motor shaft, the rotating shaft, the input shaft, the left half shaft gear and the right half shaft gear are coaxially arranged.

[0012] Preferably, four shoulders are provided on the cross shaft, and four star gears are respectively installed on the four shoulders.

[0013] Preferably, the differential housing includes a left housing and a right housing. The left housing and the right housing are fixedly connected. The left housing is rotatably connected to the axle housing through a first high-speed bearing, and the right housing is rotatably connected to the axle housing through a second high-speed bearing. The left housing and the right housing clamp and fix the cross shaft. The left half shaft gear is rotatably connected to the left housing through a bushing, and the right half shaft gear is rotatably connected to the right housing through a bushing.

[0014] Preferably, the left housing is installed in the axle housing through a first bearing seat, and the right housing is installed in the axle housing through a second bearing seat.

[0015] Preferably, a third snap ring is clamped in the axle housing. The first bearing seat is located between the motor and the third snap ring, and the third snap ring and the motor clamp and fix the first bearing seat.

[0016] Preferably, in the axle housing where the differential is installed, a first snap ring is clamped in the axle housing. The second bearing seat is located between the first snap ring and the inner wall of the axle housing, and the first snap ring and the axle housing clamp and fix the second bearing seat.

[0017] Preferably, one end of the motor close to the differential is recessed inward to form a receiving groove, and one end of the differential protrudes from the axle housing and is inserted into the receiving groove.

[0018] The beneficial effects of the technical solution of the present utility model are as follows: Customized high-speed bearings are adopted at both ends of the differential, enabling the differential to be adapted for use with high-speed motors at 10,000 r / min, effectively reducing noise. The motor can achieve a higher power density, effectively reducing energy consumption and improving the endurance of the whole vehicle. The differential is placed at the input end of the drive axle, so the torque required to be transmitted by the differential is small, and thus a differential gear with a small volume can be used, reducing the overall volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic structural view of the drive axle Figure 1 ;

[0020] Figure 2 is a schematic structural view of the drive axle Figure 2 ;

[0021] Figure 3 is a schematic connection structure diagram of the motor, differential and braking mechanism;

[0022] Figure 4 is a schematic connection structure diagram of the reducer and the axle housing;

[0023] Figure 5 is a schematic structural view of the braking mechanism;

[0024] Figure 6 is a schematic connection structure diagram of the parking brake oil inlet joint and the parking oil cavity;

[0025] Figure 7 is a schematic connection structure diagram of the service brake oil inlet joint and the exhaust joint with the brake oil cavity.

[0026] Reference numerals: 1, motor; 11, motor shaft; 12, spline sleeve; 13, rotating shaft; 14, accommodating groove;

[0027] 21, axle housing; 211, first installation groove; 22, input shaft; 23, brake drum; 24, outer friction plate; 25, inner friction plate; 26, end plate; 27, guide pin; 28, separating spring; 29, first bearing; 20, first snap ring; 201, second snap ring;

[0028] 3, parking brake assembly; 31, parking oil cylinder body; 311, parking oil inlet; 32, first connecting portion; 33, parking brake piston; 34, first abutting portion; 35, parking oil cavity; 36, parking spring; 37, parking brake oil inlet joint;

[0029] 4. Service brake assembly; 41. Second bearing block; 411. Service brake inlet oil port; 412. Exhaust port; 42. Second connection part; 43. Service brake piston; 44. Service brake oil chamber; 45. Return bolt; 46. Return spring; 47. Service brake inlet oil joint;

[0030] 5. Differential; 51. Differential housing; 52. Right half axle gear; 53. Left half axle gear; 54. Cross shaft; 55. Star gear; 56. First bearing block; 57. Third snap ring; 58. First high-speed bearing; 59. Second high-speed bearing;

[0031] 6. Hub assembly; 60. Planet carrier; 601. Cantilever; 61. Reducer housing; 611. Double row angular contact ball bearing; 612. Spacer ring; 62. Driven gear; 63. Sun gear shaft; 64. Internal gear ring; 642. Retaining ring; 65. Planet gear; 66. Nut; 67. Locking plate; 681. First tapered roller bearing; 682. Second tapered roller bearing; 69. Fifth oil seal; 610. Output shaft;

[0032] 71. Bleeder screw; 711. Bleeder screw seat; 72. Breather. Detailed implementation mode

[0033] The embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present invention, and should not be construed as limiting the present invention.

[0034] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "clockwise", "counterclockwise", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.

[0035] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more, unless otherwise clearly defined.

[0036] In the present utility model, unless otherwise clearly defined and limited, terms such as "installation", "connection", "linkage", "fixation", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be a direct connection or an indirect connection through an intermediate medium, and it may be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0037] In the present utility model, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over" and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature. Embodiment

[0038] As Figure 1 And Figure 2 As shown, a differential structure of a high-speed electric drive axle includes a motor 1, a differential 5, a brake assembly, and a hub assembly 6; both ends of the motor 1 are fixed with a bridge housing 21, an input shaft 22 is rotatably installed inside the bridge housing 21, two groups of brake assemblies are respectively installed inside the two bridge housings 21, and the brake assemblies are arranged between the bridge housing 21 and the input shaft 22 for braking the input shaft 22; the hub assembly 6 includes a reducer housing 61, and a sun gear shaft 63, a planetary reduction structure, and an output shaft 610 rotatably installed on the reducer housing 61; the differential 5 is rotatably installed inside one bridge housing 21, the motor shaft 11 of the motor 1 is in transmission connection with the differential 5, one output end of the differential is in spline connection with an input shaft 22, the other output end of the differential is in transmission connection with another input shaft 22 through a rotating shaft 13, the rotating shaft 13 passes through the motor shaft 11, the differential 5 transmits the power input by the motor 1 to the two input shafts 22 respectively, and the two input shafts 22 are respectively in transmission connection with the two hub assemblies 6; in the hub assembly, the reducer housing 61 is fixedly connected to the adjacent bridge housing 21, one end of the sun gear shaft 63 is rotatably connected to the bridge housing 21, the sun gear shaft 63 is in transmission connection with the input shaft 22, the other end of the sun gear shaft 63 is connected to the planetary reduction structure and transmits the power to the output shaft 610 through the planetary reduction structure; wherein, the motor shaft 11 and the input shaft 22 are coaxially arranged, the input shaft 22 and the motor shaft 11 are coaxially arranged, and the input shafts 22 are parallel to each other.

[0039] One end of the differential 5 is connected to the axle housing 21 through a first high-speed bearing 58 , and the other end of the differential 5 is connected to the axle housing 21 through a second high-speed bearing 59 .

[0040] The above structure arranges the motor 1, the hub assembly 6, and the drive axle into a series transmission structure. Such an arrangement can reduce the radial size of the transmission system, reduce the overall weight of the drive axle, and make the whole machine run more smoothly; and the drive axle adopts a single motor 11 integrated with distributed differential technology, and two braking mechanisms are arranged on both sides of the motor 11. The input shaft 22 for transmission and braking is arranged in parallel with the motor shaft 11, and the output shaft 610 for connecting the hub is arranged in parallel with the motor shaft 11. This makes the structure of the drive axle more compact, the braking effect is better, the transmission efficiency is higher, the weight of the forklift is lower, the battery layout space is increased, and the vehicle's cruising range is effectively improved; and the structure of the hub assembly 6 for driving the wheel is simpler, and the maintenance of the hub assembly 6 is more convenient, so that the distance between the wheel and the ground can be better, thereby making the forklift better able to cope with complex paths.

[0041] Customized high-speed bearings are used at both ends of the differential to adapt to the use of high-speed motors of 10,000 r / min. The differential adopts a four-planetary gear structure with excellent dynamic balancing performance, which can effectively reduce noise. The motor can achieve a higher power density, effectively reduce energy consumption, and improve the endurance of the vehicle.

[0042] The differential is placed at the input end of the drive axle, so the differential needs to transmit a small torque, so a small differential gear can be used to reduce the overall volume.

[0043] In this embodiment, Figure 2 and Figure 3 The motor shaft 11 is shown to be hollow, and the rotating shaft 13 passes through the inner side of the motor shaft 11; the differential 5 includes a differential case 51, a cross shaft 54, a left side shaft gear 53, a right side shaft gear 52 and a star gear 55; the differential case 51 is rotatably mounted in the bridge housing 21 through a first high-speed bearing 58 and a second high-speed bearing 59, the cross shaft 54 ​​is fixed in the differential case 51, the star gear 55 is mounted on the cross shaft 54, the left side shaft gear 53 and the right side shaft gear 52 are respectively arranged on both sides of the cross shaft 54, the left side shaft gear 53 and the right side shaft gear 52 are rotatably matched with the differential case 51, and the left side shaft gear 53 and the right side shaft gear 52 are both meshed with the star gear 55; the right side shaft gear 52 is transmission-connected to one input shaft 22, and the left side shaft gear 53 is transmission-connected to another input shaft 22 through the rotating shaft 13. With this arrangement, the differential adopts a four-planetary gear structure, which can make the differential have a more superior dynamic balance performance.

[0044] Further, the input shaft 22 within the bridge body located on the right end side is inserted into the central hole of the right half shaft gear 52 of the differential 5 and is splined; the right end of the rotating shaft 13 is inserted into the central hole of the left half shaft gear 53 of the differential 5 and is splined, and after passing through the motor shaft 11, the rotating shaft 13 is in transmission connection with the input shaft 22 within the bridge body on the left side through a spline sleeve 12.

[0045] Further, the motor shaft 11, the rotating shaft 13, the input shaft 22, the left half shaft gear 53 and the right half shaft gear 52 are coaxially arranged. With such an arrangement, the overall layout of the bridge body adopts a "one" - shaped structure layout, which can effectively simplify the structure of the drive axle, and the differential is placed at the input end with a small transmitted torque, so a differential gear with a small volume can be used, reducing the overall volume.

[0046] Further preferably, four shoulders are provided on the cross shaft 54, and four star - shaped gears 55 are respectively installed on the four shoulders.

[0047] In this embodiment, the differential housing 51 includes a left housing and a right housing. The left housing and the right housing are fixedly connected. The left housing is rotatably connected to the axle housing 21 through a first high - speed bearing 58, and the right housing is rotatably connected to the axle housing 21 through a second high - speed bearing 59; the left housing and the right housing clamp and fix the cross shaft 54. The left half shaft gear 53 is rotatably connected to the left housing through a bushing, and the right half shaft gear 52 is rotatably connected to the right housing through a bushing.

[0048] Further, the left housing is installed in the axle housing 21 through a first bearing seat 56, and the right housing is installed in the axle housing 21 through a second bearing seat 41. Specifically, a third snap ring 57 is snap - fitted in the axle housing 21. The first bearing seat 56 is located between the motor 1 and the third snap ring 57, and the third snap ring 57 and the motor 1 clamp and fix the first bearing seat 56; in the axle housing 21 where the differential 5 is installed, a first snap ring 20 is snap - fitted in the axle housing 21. The second bearing seat 41 is located between the first snap ring 20 and the inner wall of the axle housing 21, and the first snap ring 20 and the axle housing 21 clamp and fix the second bearing seat 41.

[0049] In this embodiment, one end of the motor 1 close to the differential 5 is recessed inward to form a receiving groove, and one end of the differential 5 protrudes from the axle housing 21 and is inserted into the receiving groove. Specifically, the end cover at the right end of the motor is concave, and the left end of the first bearing seat and the left housing of the differential are inserted into the right end of the motor. This can make the structure of the drive axle more compact.

[0050] In this embodiment, as Figure 2 、 Figure 3 and Figure 4As shown, the planetary reduction structure includes an internal gear ring 64, planetary gears 65, and a planetary carrier 60. The internal gear ring 64 is fixed within a reducer housing 61. Part of a sun gear shaft 63 and part of the planetary carrier 60 are located inside the internal gear ring. The planetary gears 65 are rotatably mounted on the planetary carrier 60. The planetary gears 65 are located between the internal gear ring 64 and the sun gear shaft 63. The planetary gears 65 are meshed and connected to the internal gear ring 64, and the planetary gears 65 are meshed and connected to the sun gear shaft 63. The planetary carrier 60 is fixedly connected to an output shaft 610. The output shaft 610 and the sun gear shaft 63 are coaxially arranged.

[0051] To make the structure of the drive axle more compact, in this embodiment, as Figure 3 and Figure 4 shown, a first mounting groove 211 is formed on an end face of the axle housing 21 close to the reducer housing 61. The reducer housing 61 is fixed to the axle housing 21 by bolts and covers the first mounting groove 211. Among them, the input shaft 22 is rotatably connected to the axle housing through a ball bearing. One end of the input shaft 22 extends into the first mounting groove 211 and is rotatably connected to the reducer housing 61 through a cylindrical roller bearing. In this way, the input shaft adopts a double-support structure, reducing the transmission error of the gears and meeting the requirements of light load and high speed. One end of the sun gear shaft 63 extends into the first mounting groove 211. The driven gear 62 is located in the first mounting groove 211 and is rotatably connected to the axle housing 21 through a double-row angular contact ball bearing 611. The other end of the sun gear shaft 63 is meshed and connected to the planetary gear 65. Furthermore, the sun gear shaft 63 is floatingly mounted within the drive axle. With such a setting, a sun gear floating structure is adopted to improve the centering of the sun gear during the transmission process and reduce the influence of errors generated during manufacturing and assembly on the transmission noise.

[0052] To facilitate the connection of the planetary gears 65, in this embodiment, as Figure 4 shown, a cantilever 601 protrudes from the planetary carrier 60. The cantilever 601 extends into the internal gear ring 64. The planetary gears 65 are rotatably mounted on the cantilever 601 through roller bearings. With such a setting, a single-cantilever structure is adopted on the planetary carrier. This structure is used on a light-load gearbox, with a simple structure and convenient processing. Among them, the roller bearing adopts a design with unequal thickness of the two-side flanges and can bear bidirectional axial loads.

[0053] The connection method between the planetary carrier 60 and the output shaft 610 is that, in this embodiment, a central hole is formed at the central position of the planetary carrier 60. The output shaft 610 includes a connection portion matching the central hole. One end of the output shaft 61022 passes through the central hole. The connection portion is located within the central hole. The connection portion is splined to the planetary carrier 60. A nut 66 is threadedly connected to the end of the output shaft 610 extending from the planetary carrier 60. The nut 66 abuts against the planetary carrier 60 to achieve the fixed connection between the planetary carrier 60 and the output shaft 610. Further preferably, as Figure 4As shown, a screw is threadedly connected to the planet carrier. A lock plate and a gasket are sleeved on the screw. When the lock plate 67 is locked with the planet carrier, the gasket presses the lock plate 67 tightly, and the lock plate 67 abuts against the side surface of the nut 66 to prevent the nut 66 from rotating. With such a setting, the nut is used to fix the planet carrier on the output shaft. By tightening the nut, the bearing is preloaded. To prevent loosening, a structure of key + bolt + lock washer is adopted, effectively reducing the accident of the tire flying out caused by the nut falling off during operation.

[0054] The connection mode between the planet carrier 60 and the output shaft 610 and the reducer housing 61 is as follows: Figure 4 As shown, the planet carrier 60 is rotatably connected to the reducer housing 61 through a first tapered roller bearing 681. The connecting portion of the output shaft 610 is located inside the first tapered roller bearing 681. The output shaft 610 is rotatably connected to the reducer housing 61 through a second tapered roller bearing 682. Among them, the first tapered roller bearing 681 and the second tapered roller bearing 682 are symmetrically arranged. With such a setting, two tapered roller bearings are arranged back to back, which is beneficial to the support of the output shaft and makes the structure more stable.

[0055] The fixing method of the first tapered roller bearing 681 and the second tapered roller bearing 682 is as follows: Figure 4 As shown, a spacer ring 612 is arranged inside the reducer housing 61. The spacer ring 612 is located between the first tapered roller bearing 681 and the second tapered roller bearing 682. The outer rings of the first tapered roller bearing 681 and the second tapered roller bearing 682 respectively abut against the two ends of the spacer ring 612. One end of the output shaft 610 outside the reducer housing 61 is a second mounting portion for connecting the wheel. The first tapered roller bearing 681 and the second tapered roller bearing 682 are located between the cantilever 601 and the second mounting portion. The inner ring of the first tapered roller bearing 681 abuts against the cantilever 601, and the inner ring of the second tapered roller bearing 682 abuts against the second mounting portion.

[0056] In this embodiment, as Figure 1 and Figure 2 shown, the drive axle is a wet drive axle. The drive axle is filled with oil. An oil filling and ventilation hole communicating with its interior is opened on the axle housing 21, and a breather 72 is installed on the oil filling and ventilation hole.

[0057] In order to prevent the hub assembly from leaking oil, in this embodiment, a fifth oil seal 69 is arranged between the output shaft 610 and the reducer housing 61. The fifth oil seal is a cartridge oil seal. With such a setting, the hub assembly has the advantages of strong anti-pollution ability, long service life, the sealing lip is inside the oil seal, reducing the requirement for the roughness of the housing, saving processing costs, good processability, simple installation, and avoiding the damage of the oil seal lip caused by misoperation during installation, resulting in oil leakage.

[0058] In this embodiment, it further includes hub bolts which are press-fitted onto the output shaft with interference, and the hub bolts are located outside the reducer housing.

[0059] The above braking mechanism is an integrated mechanism for service braking and parking braking, such as Figure 2 , Figure 3 and Figure 5 shown. The braking assembly includes an inner friction plate 25, an outer friction plate 24, a service braking component 4, and a parking braking component 3. The input shaft 22 is rotatably installed in the axle housing 21. Both the outer friction plate 24 and the inner friction plate 25 are sleeved on the input shaft 22. The outer friction plate 24 is slidably connected to the axle housing 21 and circumferentially fixed, and the inner friction plate 25 is slidably connected to the input shaft 22 and circumferentially fixed.

[0060] Such as Figure 2 , Figure 3 and Figure 5 shown, the service braking component 4 includes a service braking piston 43, a service oil cylinder body, and a return spring 46 for driving the service braking piston 43 to reset. The service oil cylinder body is fixed on the axle housing 21. The service braking piston 43 is slidably installed on the service oil cylinder body. A service oil chamber 44 is provided between the service braking piston 43 and the service oil cylinder body. When the service oil chamber 44 is filled with oil, the service braking piston 43 approaches and pushes against the inner friction plate 25, causing the inner friction plate 25, the outer friction plate 24, and the axle housing 21 to be pressed tightly together. When the service oil chamber 44 drains oil, the return spring 46 pushes the service braking piston 43 away from the inner friction plate 25, causing the inner friction plate 25, the outer friction plate 24, and the axle housing 21 to separate from each other. In this embodiment, the second bearing seat is used as the service oil cylinder body.

[0061] The parking braking component 3 includes a parking braking piston 33, a parking oil cylinder body 31, and a parking spring 36 for driving the parking braking piston 33 to reset. The parking oil cylinder body 31 is fixed on the axle housing 21. The parking braking piston 33 is slidably installed on the parking oil cylinder body 31. A parking oil chamber 35 is provided between the parking braking piston 33 and the parking oil cylinder body 31. When the parking oil chamber 35 is filled with oil, the parking braking piston 33 moves away from the inner friction plate 25, causing the inner friction plate 25, the outer friction plate 24, and the axle housing 21 to separate from each other. When the parking oil chamber 35 drains oil, the parking spring 36 pushes the parking braking piston 33, causing the parking braking piston 33 to approach and push against the inner friction plate 25, causing the inner friction plate 25, the outer friction plate 24, and the axle housing 21 to be pressed tightly together.

[0062] With such a setting, the above solution integrates the parking braking structure and the service braking structure, thereby slowing down the braking structure of the vehicle and making the structure of the drive axle more compact. In the above solution, service braking and parking braking are achieved through a set of friction plates, which reduces the number of friction plates used, reduces the drag torque, reduces the power loss, and improves the transmission efficiency.

[0063] In this embodiment, as Figure 2 and Figure 3 shown, a cavity with an opening facing the motor 1 is provided on the axle housing 21, and the input shaft 22, the inner friction plate 25, the outer friction plate 24, the service brake assembly 4 and the parking brake assembly 3 are all installed in the cavity of the axle housing 21.

[0064] In this embodiment, as Figure 2 , Figure 3 and Figure 5 shown, the cavity of the axle housing 21 includes a side wall and an annular inner wall. A first clamping groove is formed on the inner wall, and a first snap ring 20 is clamped at the first clamping groove. The side wall of the axle housing 21, the parking oil cylinder body 31, the service oil cylinder body and the first snap ring 20 are sequentially abutted, and the parking oil cylinder body 31 and the service oil cylinder body are tightly fitted with the inner wall of the axle housing 21, thereby fixing the parking oil cylinder body 31 and the service oil cylinder body in the axle housing 21.

[0065] In this embodiment, as Figure 2 , Figure 3 and Figure 5 shown, both the parking brake piston 33 and the service brake piston 43 are annular, and the input shaft 22 passes through the inner sides of the outer friction plate 24, the inner friction plate 25, the parking brake piston 33 and the service brake piston 43. With such a setting, the annular pistons can abut against the friction plates more evenly, thereby making the braking effect more stable.

[0066] In this embodiment, as Figure 2 , Figure 3 and Figure 5 shown, both the parking oil cylinder body 31 and the service oil cylinder body are annular, the input shaft 22 passes through the inner sides of the parking oil cylinder body 31 and the service oil cylinder body, and the parking oil cavity 35 between the parking oil cylinder body 31 and the parking brake piston 33 is annularly arranged, and the service oil cavity 44 between the service oil cylinder body and the service brake piston 43 is annularly arranged. With such a setting, the movement of the pistons is more uniform and stable, thereby improving the braking effect of the integrated mechanism.

[0067] In order to make the structure of the integrated mechanism more compact, in this embodiment, as Figure 5As shown in the figure, a first connecting portion 32 protrudes inwardly from the parking oil cylinder body 31, and a first abutting portion 34 protrudes inwardly from the parking brake piston 33 against the inner friction plate 25. The first abutting portion 34 is located inside the first connecting portion 32, and the first abutting portion 34 can extend out from the inside of the first connecting portion 32 and press the inner friction plate 25 tightly. The parking oil cylinder body 31, the first connecting portion 32, the first abutting portion 34, and the parking brake piston 33 enclose a parking oil chamber 35. A second connecting portion 42 protrudes inwardly from the service brake cylinder body against the inner friction plate 25. The second connecting portion 42 is located inside the parking brake piston 33. A first accommodation groove is provided on the end face of the second connecting portion 42 close to the inner friction plate 25. The first accommodation groove is a stepped groove. Part of the service brake piston 43 is inserted into the first accommodation groove and matches the first accommodation groove. The stepped first accommodation groove and the service brake piston 43 enclose a service brake oil chamber 44. With such a setting, the structure between the service brake assembly 4 and the parking brake assembly 3 is more compact, further improving the utilization rate of the space inside the axle housing 21 and further enhancing the integration rate of the integrated mechanism.

[0068] Further preferably, as Figure 2 and Figure 5 shown in the figure, the parking brake piston 33 is located between the first connecting portion 32 and the service brake cylinder body. A second accommodation groove is provided on the parking brake piston 33, and a third accommodation groove is provided on the service brake cylinder body. The parking spring 36 is located between the second accommodation groove and the third accommodation groove, and both ends of the parking spring 36 abut against the inner walls of the second accommodation groove and the third accommodation groove respectively.

[0069] Further preferably, a fourth accommodation groove is provided on the service brake piston 43, and a plurality of through holes are provided in the fourth accommodation groove. A threaded hole coaxial with the through hole is provided in the first accommodation groove of the service brake cylinder body; the return bolt 45 includes a head, an intermediate connecting portion, and a threaded portion connected in sequence. The return spring 46 of the service brake assembly 4 is sleeved on the intermediate connecting portion. The threaded portion of the return bolt 45 passes through the through hole and is threadedly connected to the threaded hole on the service brake cylinder body. Part of the intermediate connecting portion extends into the through hole of the service brake piston 43. Both ends of the return spring 46 abut against the head of the return bolt 45 and the service brake piston 43 respectively. Further preferably, there are a plurality of return bolts 45, and the plurality of return bolts 45 are evenly arranged around the input shaft 22.

[0070] To ensure the sealing performance of the parking oil chamber 35 and the service brake oil chamber 44, in this embodiment, in the parking oil chamber 35, a first oil seal is provided between the first connecting portion 32 and the first abutting portion 34, and a second oil seal is provided between the parking brake piston 33 and the parking oil cylinder body 31; in the service brake oil chamber 44, a third oil seal is provided between the second abutting portion and the first accommodating groove, and a fourth oil seal is provided between the service brake piston 43 and the inner wall of the first accommodating groove. Further preferably, the first oil seal, the second oil seal, the third oil seal and the fourth oil seal are all Struth seals. Further preferably, the first oil seal is fixed on the first connecting portion 32, the second oil seal is fixed on the parking oil cylinder body 31, and the third oil seal and the fourth oil seal are both fixed in the accommodating groove. With such an arrangement, the sealing effect of the oil chamber is ensured, and the stability of the braking force is ensured.

[0071] To facilitate the entry and exit of oil into and out of the parking oil chamber 35 and the service brake oil chamber 44, in this embodiment, as Figure 6 and Figure 7 shown, the parking oil cylinder body 31 is provided with a parking oil inlet 311 communicating with the parking oil chamber 35, and a parking brake oil inlet joint 37 inserted into the parking oil inlet 311 is installed on the axle housing 21; as Figure 1 and Figure 5 shown, the service brake oil cylinder body is provided with a service brake oil inlet 411 communicating with the service brake oil chamber 44, and a service brake oil inlet joint 47 inserted into the service brake oil inlet 411 is installed on the axle housing 21. With such an arrangement, it is convenient for the entry and exit of hydraulic oil and the connection of oil pipes. The parking oil cylinder body can also be prevented from rotating relative to the axle housing 21 through the brake oil inlet joint, thereby ensuring the stability of the oil cylinder position. Further preferably, the radial and end faces of the parking brake oil inlet joint 37 are sealed with O-rings, and the radial and end faces of the service brake oil inlet joint 47 are sealed with O-rings. Further preferably, as Figure 1 and Figure 5 shown, the service brake oil cylinder body is also provided with an exhaust port 412 communicating with the service brake oil chamber 44, and a bleed screw seat 711 inserted into the exhaust port 412 is installed on the axle housing 21, and a bleed screw 71 is installed on the bleed screw seat.

[0072] To further improve the stability of the mechanism, in this embodiment, the parking oil cylinder body 31 is fixed to the axle housing 21 by screws, and the screws extend axially. With such an arrangement, the radial direction of the parking oil cylinder body 31 is restricted by the axle housing 21, the circumferential direction of the parking oil cylinder body 31 is restricted by the parking brake oil inlet joint 37, and the circumferential direction of the parking oil cylinder body 31 is restricted by the screws, thereby integrating the axle housing 21 and the parking oil cylinder body 31 into a whole and reducing the risk of movement of the service brake oil cylinder body.

[0073] To improve the braking effect, in this embodiment, as Figure 5As shown, the end of the first abutting portion 34 of the parking brake piston 33 protrudes with a third abutting portion, and the second abutting portion of the service brake piston 43 protrudes with a fourth abutting portion; when the parking brake piston 33 brakes, the end face of the first abutting portion 34 and the end face of the third abutting portion abut against the inner friction plate 25; when the service brake piston 43 brakes, the end face of the second abutting portion and the end face of the fourth abutting portion abut against the inner friction plate 25. With such a setting, the contact area between the piston and the friction plate is increased, and the braking effect is improved.

[0074] Further preferably, the fourth abutting portion is located inside the third abutting portion, and both the third abutting portion and the fourth abutting portion are located between the inner friction plate 25 and the second connecting portion 42 of the service brake cylinder block. With such a setting, the compactness of the integrated mechanism is further improved.

[0075] In order to make the integrated mechanism more compact, in this embodiment, the inner friction plate 25 is located inside the parking brake cylinder block 31, and the inner friction plate 25 and the parking brake piston 33 are arranged on both sides of the first connecting portion 32. With such a setting, the connection effect of the integrated mechanism is improved, and the integration of the service brake and the parking brake is further improved.

[0076] In order to improve the durability of the integrated mechanism, in this embodiment, an end plate 26 that can slide axially along the input shaft 22 is installed between the inner friction plate 25 and the first connecting portion 32 of the parking brake cylinder block 31. The service brake piston 43 and the parking brake piston 33 push against the end plate 26 to press the inner friction plate 25 and the outer friction plate 24, thereby better protecting the brake piston.

[0077] Further preferably, a plurality of guide pins 27 are fixed inside the opening of the axle housing 21. The plurality of guide pins 27 are located inside the parking brake cylinder block 31, the plurality of guide pins 27 are evenly arranged around the input shaft 22, and the plurality of guide pins 27 all pass through the end plate 26 and the outer friction plate 24. With such a setting, the moving paths of the outer friction plate 24 and the end plate 26 are the same, and the braking stability is improved.

[0078] Further preferably, as Figure 5 shown, a separating spring 28 is sleeved on the guide pin 27, and both ends of the separating spring 28 abut against the end plate 26 and the outer friction plate 24 respectively. With such a setting, the separating spring 28 is added between the friction plates, the drag torque is reduced, the power loss is reduced, and the transmission efficiency is improved.

[0079] Further preferably, as Figure 5As shown, a fifth accommodation groove is formed in the side wall of the cavity of the axle housing 21, and a sixth accommodation groove is formed in the first connecting portion 32 of the parking oil cylinder body 31. Both ends of the guide pin 27 are respectively located in the fifth accommodation groove and the sixth accommodation groove and are in a tight fit. With such a setting, the positioning between the parking oil cylinder body 31 and the axle housing 21 can be made more accurate through the guide pin 27, and at the same time, the assembly of the integrated mechanism is also facilitated.

[0080] In this embodiment, as Figure 3 and Figure 5 shown, a brake drum 23 is sleeved and fixedly installed on the input shaft 22. The inner friction plate 25, the outer friction plate 24 and the end plate 26 are all sleeved on the brake drum 23, and the inner friction plate 25 is splined to the brake drum 23. Among them, the connection method between the brake drum 23 and the input shaft 22 is that a step protrudes on the input shaft 22. The second snap ring 201, the first bearing 29 and the brake drum 23 are sequentially sleeved on the input shaft 22. The second snap ring 201 is clamped to the input shaft 22, the brake drum 23 is splined to the input shaft 22, the second snap ring 201, the first bearing 29, the brake drum 23 and the step on the input shaft 22 are sequentially abutted tightly, and the second snap ring 201 and a part of the brake drum 23 can extend into the opening of the service brake piston 43. With such a setting, it can be avoided that the friction plates directly work on the input shaft 22, thereby avoiding damage to the input shaft 22, effectively utilizing the space inside the motor 1 housing, and making the structure of the integrated mechanism more compact.

[0081] During the vehicle's travel: The parking oil chamber is filled with oil, the parking brake piston moves away from the friction plates and compresses the parking spring. The service oil chamber is not filled with oil, the return spring pushes the service brake piston away from the friction plates, and the separation spring pushes the outer friction plate, the inner friction plate and the end plate to separate from each other. The input shaft 22 is in a free rotation state;

[0082] When the vehicle brakes during driving, the service oil chamber is filled with oil, the hydraulic oil pushes the service brake piston to move, the service brake piston moves to compress the return spring, the service brake piston moves to press the end plate, the inner friction plate and the outer friction plate tightly, and the end plate moves to compress the separation spring; the end plate, the inner friction plate and the outer friction plate are gradually pressed against each other to reduce the rotation speed of the input shaft 22, completing the braking during the vehicle's driving;

[0083] When the vehicle stops: The parking oil chamber is filled with oil, the parking brake piston moves away from the friction plates and compresses the parking spring. The service oil chamber is not filled with oil, the return spring pushes the service brake piston away from the friction plates, and the separation spring pushes the outer friction plate, the inner friction plate and the end plate to separate from each other. The input shaft 22 is in a free rotation state;

[0084] When the vehicle parks during the parking process, the parking oil chamber drains oil, the parking spring pushes the parking brake piston to move, the parking brake piston moves to press the end plate, the inner friction plate and the outer friction plate tightly, and the end plate moves to compress the separation spring; thus, the parking action is completed.

[0085] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0086] Although the embodiments of the present utility model have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limitations to the present utility model. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present utility model without departing from the principles and purposes of the present utility model.

Claims

1. A differential structure of a high-speed electric drive axle, characterized in that: It includes a motor (1), a bridge housing (21), a differential (5), a brake assembly, and two sets of hub assemblies (6); Two bridge housings (21) are respectively fixed on both sides of the motor (1), and two sets of hub assemblies (6) are respectively installed on the two bridge housings (21); An input shaft (22) is rotatably installed in the bridge housing (21), and the brake assembly is arranged between the bridge housing (21) and the input shaft (22); The differential (5) is rotatably installed in one bridge housing (21), the motor shaft (11) of the motor (1) is in transmission connection with the differential (5), one output end of the differential (5) is in transmission connection with an input shaft (22), and the other output end of the differential (5) is in transmission connection with another input shaft (22) through a rotating shaft (13). The rotating shaft (13) passes through the motor shaft (11). The differential (5) transmits the power of the motor (1) to the two input shafts (22) respectively, and the two input shafts (22) are respectively in transmission connection with the two hub assemblies (6); One end of the differential (5) is connected to the bridge housing (21) through a first high-speed bearing (58), and the other end of the differential (5) is connected to the bridge housing (21) through a second high-speed bearing (59).

2. The differential structure of a high-speed electric drive axle according to claim 1, characterized in that: The differential (5) includes a differential housing (51), a cross shaft (54), a left half shaft gear (53), a right half shaft gear (52), and a star gear (55); The differential housing (51) is rotatably installed in the bridge housing (21) through a first high-speed bearing (58) and a second high-speed bearing (59). The cross shaft (54) is fixed in the differential housing (51). The star gear (55) is installed on the cross shaft (54). The left half shaft gear (53) and the right half shaft gear (52) are respectively arranged on both sides of the cross shaft (54). The left half shaft gear (53) and the right half shaft gear (52) are rotationally matched with the differential housing (51), and both the left half shaft gear (53) and the right half shaft gear (52) are meshed with the star gear (55); The right half shaft gear (52) is in transmission connection with an input shaft (22), and the left half shaft gear (53) is in transmission connection with another input shaft (22) through a rotating shaft (13).

3. The differential structure of a high-speed electric drive axle according to claim 2, characterized in that: The motor shaft (11), the rotating shaft (13), the input shaft (22), the left half shaft gear (53), and the right half shaft gear (52) are coaxially arranged.

4. The differential structure of a high-speed electric drive axle according to claim 2, characterized in that: Four shoulders are arranged on the cross shaft (54), and four star gears (55) are respectively installed on the four shoulders.

5. The differential structure of a high-speed electric drive axle according to claim 2, wherein: The differential housing (51) includes a left housing and a right housing. The left housing and the right housing are fixedly connected. The left housing is rotationally connected to the bridge housing (21) through a first high-speed bearing (58), and the right housing is rotationally connected to the bridge housing (21) through a second high-speed bearing (59); The left housing and the right housing clamp and fix the cross shaft (54). The left half shaft gear (53) is rotationally connected to the left housing through a bushing, and the right half shaft gear (52) is rotationally connected to the right housing through a bushing.

6. The differential structure of a high-speed electric drive axle according to claim 5, characterized in that: The left housing is installed in the bridge housing (21) through a first bearing seat (56), and the right housing is installed in the bridge housing (21) through a second bearing seat (41).

7. The differential structure of a high-speed electric drive axle according to claim 6, characterized in that: A third snap ring (57) is snap-fitted inside the axle housing (21). The first bearing seat (56) is located between the motor (1) and the third snap ring (57). The third snap ring (57) and the motor (1) clamp and fix the first bearing seat (56).

8. The differential structure of a high-speed electric drive axle according to claim 6, characterized in that: In the axle housing (21) where the differential (5) is installed, a first snap ring (20) is snap-fitted inside the axle housing (21). The second bearing seat (41) is located between the first snap ring (20) and the inner wall of the axle housing (21). The first snap ring (20) and the axle housing (21) clamp and fix the second bearing seat (41).

9. The differential structure of a high-speed electric drive axle according to claim 1, characterized in that: One end of the motor (1) near the differential (5) is recessed inward to form a receiving groove (14). One end of the differential (5) protrudes from inside the axle housing (21) and is inserted into the receiving groove (14).

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