Wet type parking braking and traveling braking integrated double-planet-row coaxial electric drive axle assembly

Abstract

The utility model discloses a wet-type parking braking and traveling braking integrated double-planet-row coaxial electric drive axle assembly which comprises two sets of symmetrically-arranged driving structures, and the two sets of driving structures output power from the left side and the right side respectively. The driving structure comprises a motor, an axle housing, a braking mechanism, a hub housing, a double-planet-row speed reducing mechanism and a hub which are arranged in sequence; the motor shell, the axle shell and the hub shell are sequentially arranged and fixedly connected, and the motor shaft, the double-planet-row speed reducing mechanism and the hub are sequentially arranged and in transmission connection. The double-planet-row speed reducing mechanism is arranged in the hub shell, the hub is rotationally connected with the hub shell, the motor shaft penetrates through the axle shell and then is connected with the double-planet-row speed reducing mechanism, and the braking mechanism is arranged between the motor shaft and the axle shell. Through the arrangement, the overall layout of the drive axle is compact, particularly the radial size of the drive axle is reduced, the structural arrangement of a forklift is facilitated, and the production cost is reduced.

Description

Technical Field

[0001] The utility model relates to the field of electric drive axles, in particular to a double planetary gear coaxial electric drive axle assembly integrating wet parking brake and driving brake. Background Art

[0002] With the development of my country's logistics economy, forklifts are more commonly used, and the design and manufacturing of forklift transmission components are gradually mature. Forklifts tend to develop in the direction of new energy, and transmission components also tend to be integrated. The axis of the existing drive axle motor in China is arranged horizontally or vertically outside the drive axle box, so the transmission system will take up a lot of space in the horizontal or vertical direction, which brings difficulties to the layout of the whole vehicle.

[0003] The prior art with publication number CN115503397A discloses a distributed motor-driven axle, comprising a bridge housing, two power assemblies and two rims. The two power assemblies are symmetrically arranged on both sides of the central axis of the bridge housing along a first direction. Each power assembly comprises a motor, a first reducer, a brake and a second reducer arranged in sequence. The first reducer is transmission-connected to the motor, and the second reducer is transmission-connected to the first reducer. The rim is used for wheel installation. The second reducer and the brake are both located on the inner side of the rim, and the brake is used to control the deceleration or stop of the rim.

[0004] In the prior art, two groups of reducers are respectively arranged on the motor and the rim, which makes the structure of the drive axle more complicated; and the brake is arranged between the first reducer and the second reducer, which makes the drive axle less effective in diverting and decoupling the motor power, and the braking feedback of the drive axle is longer and the braking effect is poorer. Utility Model Content

[0005] In order to solve the problem of complex drive axle structure in the prior art, the purpose of the utility model is to provide a double planetary gear coaxial electric drive axle assembly that integrates wet parking brake and service brake. The structure of the drive axle assembly is more compact, the effect of motor power diversion and decoupling is better, and the energy consumption of the drive axle is lower.

[0006] In order to achieve the above-mentioned purpose, the utility model adopts the following technical solutions: a double planetary gear coaxial electric drive axle assembly integrating wet parking brake and driving brake, including two sets of symmetrically arranged drive structures, the two sets of drive structures output power from the left and right sides respectively; the drive structure includes a motor, a bridge housing, a brake mechanism, a wheel hub housing, a double planetary gear reduction mechanism and a wheel hub arranged in sequence;

[0007] The motor housing, the axle housing, and the hub housing are arranged in sequence and fixedly connected. The motor shaft, the double planetary row reduction mechanism, and the hub are arranged in sequence and transmission-connected. The double planetary row reduction mechanism is arranged inside the hub housing. The hub is rotationally connected to the hub housing. The motor shaft passes through the axle housing and is connected to the double planetary row reduction mechanism. The braking mechanism is arranged between the motor shaft and the axle housing.

[0008] Preferably, the double planetary row reduction mechanism includes a first-stage planetary row and a second-stage planetary row. The motor shaft of the motor is transmission-connected to the first-stage planetary row. The first-stage planetary row is transmission-connected to the second-stage planetary row. The second-stage planetary row is transmission-connected to the hub.

[0009] Preferably, the first-stage planetary row includes a first-stage internal gear ring, a first-stage planetary carrier, and multiple first-stage planetary gears. The first-stage internal gear ring is fixed inside the hub. The multiple first-stage planetary gears are rotatably installed on the first-stage planetary carrier. The multiple first-stage planetary gears are located inside the first-stage internal gear ring. The first-stage planetary gears are meshed with the first-stage internal gear ring. The motor shaft extends into the space between the multiple first-stage planetary gears and is meshed with the first-stage planetary gears. The second-stage planetary row includes a second-stage internal gear ring, a second-stage planetary carrier, a sun gear, and multiple second-stage planetary gears. The second-stage internal gear ring is fixed inside the hub. The multiple second-stage planetary gears are rotatably installed on the second-stage planetary carrier. The multiple second-stage planetary gears are located inside the second-stage internal gear ring. The second-stage planetary gears are meshed with the second-stage internal gear ring. One end of the sun gear extends into the inner hole of the first-stage planetary carrier and is meshed with the first-stage planetary carrier. The other end of the sun gear extends into the space between the multiple second-stage planetary gears and is meshed with the second-stage planetary gears. One end of the hub is connected to the hub housing and fixedly connected to the second-stage planetary carrier. The output flange is meshed with the second-stage planetary carrier.

[0010] Preferably, multiple first cantilevers protrude from the first-stage planetary carrier. The multiple first-stage planetary gears correspond to the multiple first cantilevers one by one. The first-stage planetary gears are rotatably installed on the first cantilevers. Multiple second cantilevers protrude from the second-stage planetary carrier. The multiple second-stage planetary gears correspond to the multiple second cantilevers one by one. The second-stage planetary gears are rotatably installed on the second cantilevers.

[0011] Preferably, the first-stage planetary gears are installed on the first-stage planetary carrier through double row angular contact ball bearings. The second-stage planetary gears are installed on the second-stage planetary carrier through roller bearings. The hub is installed on the hub housing through two symmetrically arranged tapered roller bearings.

[0012] Preferably, the hub is fixedly connected to the second-stage planetary carrier. One end of the hub is the input end. A nut is threadedly connected to the input end. The input end is inserted into the inner hole of the second-stage planetary carrier and is spline-connected to the second-stage planetary carrier. A pressing plate is connected to the end of the input end through screws. The pressing plate and the nut are respectively located on both sides of the second-stage planetary carrier. The nut and the pressing plate clamp the second-stage planetary carrier.

[0013] Preferably, the other end of the wheel hub is a flange end, which is located outside the wheel hub housing; an opening facing the wheel hub housing is provided on the flange end, the end of the wheel hub is inserted into the opening of the flange end, and a fifth oil seal is provided between the wheel hub and the flange end.

[0014] Preferably, the braking assembly includes an inner friction plate, an outer friction plate, a service braking assembly and a parking braking assembly. The inner friction plate and the outer friction plate are both sleeved on the motor shaft. The inner friction plate is slidably fitted with the motor shaft and axially fixed. The outer friction plate is slidably fitted with the axle housing and axially fixed. The inner friction plate and the outer friction plate are alternately arranged. The service braking assembly is used to drive the inner friction plate and the outer friction plate to be combined to brake the motor shaft in the driving state. The parking braking assembly is used to drive the inner friction plate and the outer friction plate to be combined to brake the motor shaft in the parking state.

[0015] Preferably, the parking braking assembly includes a parking brake piston, a parking oil cylinder body and a parking spring for driving the parking brake piston to reset. The parking oil cylinder body is fixed on the axle housing. The parking brake piston is slidably installed on the parking oil cylinder body. A parking oil chamber is provided between the parking brake piston and the parking oil cylinder body. When the parking oil chamber is filled with oil, the parking brake piston is away from the inner friction plate, so that the inner friction plate, the outer friction plate and the axle housing are separated from each other. When the parking oil chamber is drained of oil, the parking spring pushes the parking brake piston, so that the parking brake piston approaches and pushes the inner friction plate, so that the inner friction plate, the outer friction plate and the axle housing are tightly abutted against each other.

[0016] Preferably, the service braking assembly includes a service brake piston, a service oil cylinder body and a return spring for driving the service brake piston to reset. The service oil cylinder body is fixed on the axle housing. The service brake piston is slidably installed on the service oil cylinder body. A service oil chamber is provided between the service brake piston and the service oil cylinder body. When the service oil chamber is filled with oil, the service brake piston approaches and pushes the inner friction plate, so that the inner friction plate, the outer friction plate and the axle housing are tightly abutted against each other. When the service oil chamber is drained of oil, the return spring pushes the service brake piston away from the inner friction plate, so that the inner friction plate, the outer friction plate and the axle housing are separated from each other.

[0017] The beneficial effects of the technical solution of the present utility model are as follows: The motor, the braking mechanism, the double planetary row structure and the wheel hub are coaxially arranged, so that the overall layout of the drive axle is compact, especially reducing the radial dimension of the drive axle, facilitating the structural arrangement of the forklift, and reducing the production cost.

[0018] The double planetary row reduction mechanism is adopted, and the double planetary row reduction mechanism is concentrated on the wheel hub side. This structure allows the torque and speed of the engine and the motor to be decoupled, thereby improving the overall efficiency, and can achieve high-efficiency power splitting. Through precise control, the optimal cooperation between the engine and the motor can be realized, thereby improving the overall vehicle performance. In addition, this structure can adapt to different driving conditions and vehicle requirements by changing the gear ratio.

[0019] The braking mechanism directly brakes the motor shaft, thereby being able to improve the feedback rate and braking effect of the drive axle assembly braking. Description of the Drawings

[0020] Figure 1 is a schematic structural diagram of the electric drive axle assembly Figure One ;

[0021] Figure 2 is a schematic structural diagram of the electric drive axle assembly Figure Two ;

[0022] Figure 3 is Figure 2 the sectional view taken along the A-A direction in

[0023] Figure 4 is the schematic structural diagram of the drive structure;

[0024] Figure 5 is the schematic installation structure diagram of the vent cap;

[0025] Figure 6 is the schematic structural diagram of the braking mechanism;

[0026] Figure 7 is the schematic connection structure diagram of the double planetary row reduction mechanism, hub and motor shaft.

[0027] Reference numerals: 1, motor; 11, motor shaft;

[0028] 2, axle housing; 20, first snap ring; 21, limiting part;

[0029] 3, parking brake assembly; 31, parking oil cylinder body; 311, parking oil inlet; 32, first connecting part; 33, parking brake piston; 34, first abutting part; 35, parking oil cavity; 36, parking spring; 37, parking brake oil inlet joint;

[0030] 4, service brake assembly; 41, service oil cylinder body; 411, service oil inlet; 42, second connecting part; 43, service brake piston; 44, service oil cavity; 45, return bolt; 46, return spring; 47, service brake oil inlet joint;

[0031] 51, first internal gear ring; 52, first planetary carrier; 53, first planetary gear; 54, double angular contact ball bearing; 55, second internal gear ring; 56, second planetary carrier; 57, second planetary gear; 58, roller bearing; 59, sun gear;

[0032] 61, hub; 62, nut; 63, pressing plate; 64, screw; 65, tapered roller bearing; 66, spacer ring; 67, fifth oil seal;

[0033] 7. Wheel hub housing; 71. Positioning part;

[0034] 8. Breather cap. Detailed implementation manner

[0035] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals indicate the same or similar elements or elements with 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, but should not be construed as limiting the present invention.

[0036] 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. It is 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.

[0037] 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, the 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.

[0038] In the present invention, unless otherwise clearly specified and defined, the terms "installation", "connection", "connection", "fixation", etc. should 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 directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature. Example

[0040] like Figure 1-7 The double planetary gear coaxial electric drive axle assembly with wet parking brake and driving brake is shown, including two sets of symmetrically arranged drive structures, which output power from the left and right sides respectively; the drive structure includes a motor 1, a bridge housing 2, a brake mechanism, a wheel hub housing 7, a double planetary gear reduction mechanism and a wheel hub 61 which are arranged in sequence;

[0041] The motor housing, the bridge housing 2 and the wheel hub shell 7 are arranged in sequence and fixedly connected, the motor shaft 11, the double planetary gear reduction mechanism and the wheel hub 61 are arranged in sequence and transmission connected; the double planetary gear reduction mechanism is arranged in the wheel hub shell 7, the wheel hub 61 is rotationally connected to the wheel hub shell 7, the motor shaft 11 passes through the bridge housing 2 and is connected to the double planetary gear reduction mechanism, and the braking mechanism is arranged between the motor shaft 11 and the bridge housing 2.

[0042] With this arrangement, the center lines of the motor, service brake, parking brake, and hub unit assembly are on one axis, making the overall layout of the drive axle compact, especially reducing the radial size of the drive axle, facilitating the structural layout of the forklift and reducing production costs; a double planetary gear structure is adopted, which allows the torque and speed of the engine and motor to be decoupled, thereby improving the overall efficiency, and can achieve high-efficiency power diversion. Through precise control, the optimal coordination between the engine and the motor can be achieved, thereby improving the overall vehicle performance. In addition, this structure can adapt to different driving conditions and vehicle requirements by changing the gear ratio.

[0043] In this embodiment, Figure 7As shown in the figure, the double planetary gear reduction mechanism includes a primary planetary gear set and a secondary planetary gear set. The motor shaft 11 of the motor 1 is drivingly connected to the primary planetary gear set. The primary planetary gear set is drivingly connected to the secondary planetary gear set. The secondary planetary gear set is drivingly connected to the wheel hub 61. Specifically, the primary planetary gear set includes a primary internal gear ring 51, a primary planet carrier 52, and multiple primary planet gears 53. The primary internal gear ring 51 is fixed inside the wheel hub 61. The multiple primary planet gears 53 are rotatably mounted on the primary planet carrier 52. The multiple primary planet gears 53 are located inside the primary internal gear ring 51. The primary planet gears 53 mesh with the primary internal gear ring 51. The motor shaft 11 extends between the multiple primary planet gears 53 and meshes with the primary planet gears 53. The secondary planetary gear set includes a secondary internal gear ring 55, a secondary planet carrier 56, a sun gear 59, and multiple secondary planet gears 57. The secondary internal gear ring 55 is fixed inside the wheel hub 61. The multiple secondary planet gears 57 are rotatably mounted on the secondary planet carrier 56. The multiple secondary planet gears 57 are located inside the secondary internal gear ring 55. The secondary planet gears 57 mesh with the secondary internal gear ring 55. One end of the sun gear 59 extends into the inner hole of the primary planet carrier 52 and meshes with the primary planet carrier 52. The other end of the sun gear 59 extends between the multiple secondary planet gears 57 and meshes with the secondary planet gears 57. One end of the wheel hub 61 is the wheel hub housing 7 and is fixedly connected to the secondary planet carrier 56. The wheel hub meshes with the secondary planet carrier 56. Further preferably, multiple first cantilevers protrude from the primary planet carrier 52. The multiple primary planet gears 53 correspond to the multiple first cantilevers one by one. The primary planet gears 53 are rotatably mounted on the first cantilevers. Multiple second cantilevers protrude from the secondary planet carrier 56. The multiple secondary planet gears 57 correspond to the multiple second cantilevers one by one. The secondary planet gears 57 are rotatably mounted on the second cantilevers.

[0044] In this embodiment, as Figure 7 shown, the primary planet gears 53 are mounted on the first cantilevers of the primary planet carrier 52 through double row angular contact ball bearings 54. The secondary planet gears 57 are mounted on the second cantilevers of the secondary planet carrier 56 through roller bearings 58. With such an arrangement, the transmission stability can be effectively improved.

[0045] In this embodiment, as Figure 7 shown, both the primary planet gears and the secondary planet gears are cylindrical helical gears. With such an arrangement, the wheel side reduction structure of the double planetary gear train reduces the overall weight, improves the transmission efficiency, reduces the occupied space, increases the battery layout space, and effectively improves the vehicle's cruising range.

[0046] In this embodiment, as Figure 7As shown in the figure, the hub 61 is fixedly connected to the secondary planet carrier 56. One end of the hub 61 is the input end. A nut 62 is threadedly connected to the input end. The input end is inserted into the inner hole of the secondary planet carrier 56 and is spline-connected to the secondary planet carrier 56. A pressing plate 63 is connected to the end of the input end by screws 64. The pressing plate 63 and the nut 62 are respectively arranged on both sides of the secondary planet carrier 56. The nut 62 and the pressing plate 63 clamp the secondary planet carrier 56. With such a setting, it is beneficial for the positioning and assembly of the hub and the planet carrier.

[0047] In this embodiment, as Figure 2 and Figure 7 shown, the other end of the hub 61 is a flange end, and the flange end is located outside the hub housing 7. An opening facing the hub housing 7 is provided on the flange end. The end of the hub 61 is inserted into the opening of the flange end. A fifth oil seal 67 is provided between the hub 61 and the flange end. With such a setting, the sealing performance of the drive axle can be guaranteed, and the assembly and positioning difficulty of the drive axle components can be reduced through the flange end and the hub housing.

[0048] In this embodiment, as Figure 2 and Figure 7 shown, the hub 61 is installed on the hub housing 7 through two symmetrically arranged tapered roller bearings 65. Specifically, the two tapered roller bearings 65 are installed between the input end and the hub 61. Specifically, the hub housing 7 protrudes with a positioning portion 71, and the positioning portion is located between the outer rings of the two tapered roller bearings 65. A spacer 66 is provided between the inner rings of the tapered roller bearings 65. The two sets of tapered roller bearings 65 are located between the flange end and the nut 62, and the flange end and the nut 62 respectively abut against the inner rings of the two tapered roller bearings 65.

[0049] In this embodiment, as Figure 2 、 Figure 3 and Figure 7 shown, a thrust ball bearing is provided between the sun gear 59 and the motor shaft, and a thrust ball bearing is provided between the sun gear 59 and the primary planet carrier. With such a setting, the friction on the transmission path and the stress between adjacent two components can be reduced through the thrust ball bearing, helping the sun gear to achieve rotational or linear motion, thereby extending the service life of the second-stage sun gear. Since the thrust ball bearing has a certain self-aligning performance, the influence of installation errors on the bearing can also be reduced.

[0050] In this embodiment, the power transmission sequence of the drive structure is: motor, motor shaft, primary planet gear, primary planet carrier, sun gear, secondary planet gear, secondary planet carrier, and hub. When a vehicle with the above structure needs to turn, by respectively controlling the motors of the two sets of drive mechanisms, different speeds are output at the left and right ends of the vehicle, and then the vehicle turns.

[0051] In this embodiment, the braking mechanism is an integrated mechanism for service braking and parking braking, such as Figure 2 and Figure 6 shown. The braking mechanism includes an inner friction plate 25, an outer friction plate 24, a service braking assembly 4 and a parking braking assembly 3. The motor shaft 11 is rotatably installed in the axle housing 2. The outer friction plate 24 and the inner friction plate 25 are both sleeved on the motor shaft 11. A plurality of outer friction plates 24 and a plurality of inner friction plates 25 are arranged alternately. The outer friction plate 24 is slidably connected to the axle housing 2 and circumferentially fixed. The inner friction plate 25 is slidably connected to the motor shaft 11 and circumferentially fixed.

[0052] As Figure 6 shown, the service braking assembly 4 includes a service braking piston 43, a service oil cylinder body 41 and a return spring 46 for driving the service braking piston 43 to reset. The service oil cylinder body 41 is fixed on the axle housing 2. The service braking piston 43 is slidably installed on the service oil cylinder body 41. A service oil cavity 44 is provided between the service braking piston 43 and the service oil cylinder body 41. When the service oil cavity 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 2 to be pressed tightly together. When the service oil cavity 44 is drained of 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 2 to separate from each other.

[0053] The parking braking assembly 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 2. The parking braking piston 33 is slidably installed on the parking oil cylinder body 31. A parking oil cavity 35 is provided between the parking braking piston 33 and the parking oil cylinder body 31. When the parking oil cavity 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 2 to separate from each other. When the parking oil cavity 35 is drained of 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 2 to be pressed tightly together.

[0054] 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.

[0055] In this embodiment, as Figure 6 shown, a cavity with an opening facing the motor 1 is provided on the axle housing 2. The motor shaft 11, the inner friction plate 25, the outer friction plate 24, the service braking assembly 4 and the parking braking assembly 3 are all installed in the cavity of the axle housing 2.

[0056] In this embodiment, Figure 6 As shown, the cavity of the axle housing 2 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. A limiting portion 21 protrudes inside the axle housing 2. The limiting portion 21, the parking oil cylinder body 31, the driving oil cylinder body 41, and the first snap ring 20 are sequentially abutted. The parking oil cylinder body 31 and the driving oil cylinder body 41 are in tight fit with the inner wall of the axle housing 2, thereby fixing the parking oil cylinder body 31 and the driving oil cylinder body 41 inside the axle housing 2.

[0057] In this embodiment, as Figure 6 shown, both the parking brake piston 33 and the driving brake piston 43 are annular, and the motor shaft 11 passes through the inner sides of the outer friction plate 24, the inner friction plate 25, the parking brake piston 33, and the driving 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.

[0058] In this embodiment, as Figure 5 and Figure 6 shown, both the parking oil cylinder body 31 and the driving oil cylinder body 41 are annular, the motor shaft 11 passes through the inner sides of the parking oil cylinder body 31 and the driving oil cylinder body 41, and the parking oil cavity 35 between the parking oil cylinder body 31 and the parking brake piston 33 is annularly arranged. The driving oil cavity 44 between the driving oil cylinder body 41 and the driving 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.

[0059] In order to make the structure of the integrated mechanism more compact, in this embodiment, as Figure 6 shown, a first connecting portion 32 protrudes inwardly on the parking oil cylinder body 31, a first abutting portion 34 protruding toward the inner friction plate 25 is provided on the parking brake piston 33. 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. The parking oil cylinder body 31, the first connecting portion 32, the first abutting portion 34, and the parking brake piston 33 enclose the parking oil cavity 35. A second connecting portion 42 protruding toward the inner friction plate 25 is provided on the driving oil cylinder body 41. The second connecting portion 42 is located inside the parking brake piston 33. A first accommodating groove is provided on the end face of the second connecting portion 42 facing the motor shaft. The first accommodating groove is a stepped groove. Part of the driving brake piston 43 is located in the first accommodating groove and is in sliding fit with the second connecting portion 42. The stepped first accommodating groove and the driving brake piston 43 enclose the driving oil cavity 44. With such a setting, the structure between the driving brake assembly 4 and the parking brake assembly 3 is more compact, further improving the utilization rate of the space inside the axle housing 2 and further enhancing the integration rate of the integrated mechanism.

[0060] Further preferably, asFigure 5 and Figure 6 As shown in Figure 6 , the parking brake piston 33 is located between the first connecting portion 32 and the service cylinder body 41. A second accommodation groove is formed in the parking brake piston 33, and a third accommodation groove is formed in the service cylinder body 41. 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.

[0061] Further preferably, as Figure 5 and Figure 6 As shown in Figure 6 , a fourth accommodation groove is formed in the service brake piston 43, and a plurality of through holes are formed in the fourth accommodation groove. A threaded hole coaxial with the through holes is formed in the first accommodation groove of the service cylinder body 41; 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 holes and is threadedly connected to the threaded hole on the service cylinder body 41. A part of the intermediate connecting portion extends into the through holes of the service brake piston 43, and 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 motor shaft 11.

[0062] To ensure the sealing performance of the parking oil chamber 35 and the service oil chamber 44, in this embodiment, as shown in Figure 6 , 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 cylinder body 31; in the service oil chamber 44, a third oil seal is provided between the second abutting portion and the first accommodation groove, and a fourth oil seal is provided between the service brake piston 43 and the inner wall of the first accommodation 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 cylinder body 31, and the third oil seal and the fourth oil seal are both fixed in the accommodation groove. With such a setting, the sealing effect of the oil chamber is ensured, and the stability of the braking force is ensured.

[0063] To facilitate the entry and exit of the oil fluid into and out of the parking oil chamber 35 and the service oil chamber 44, in this embodiment, as shown in Figure 4 Figure 4 and Figure 6 As shown in Figure 6 , the parking 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 2; as shown in Figure 5 Figure 5 ​​As shown, a traveling oil inlet 411 communicating with the traveling oil chamber 44 is provided on the traveling oil cylinder body 41, and a traveling brake oil inlet joint 47 inserted into the traveling oil inlet 411 is installed on the axle housing 2. This setting facilitates the entry and exit of hydraulic oil and the connection of oil pipes. Through the brake oil inlet joint, the relative rotation of the parking oil cylinder body with respect to the axle housing 2 can also be prevented, thereby ensuring the stability of the cylinder position. Further preferably, O-rings are used for sealing both the radial and end faces of the parking brake oil inlet joint 37, and O-rings are used for sealing both the radial and end faces of the traveling brake oil inlet joint 47.

[0064] In order to further improve the stability of the mechanism, in this embodiment, the parking oil cylinder body 31 is fixed to the axle housing 2 by screws, and the screws extend axially. With this setting, the radial movement of the parking oil cylinder body 31 is restricted by the axle housing 2, the circumferential movement of the parking oil cylinder body 31 is restricted by the parking brake oil inlet joint 37, and the circumferential movement of the parking oil cylinder body 31 is restricted by the screws. As a result, the axle housing 2 and the parking oil cylinder body 31 are integrated into a whole, and the risk of movement of the traveling oil cylinder body 41 is reduced.

[0065] In order to improve the braking effect, in this embodiment, a third abutting portion protrudes from the end of the first abutting portion 34 of the parking brake piston 33, and a fourth abutting portion protrudes from the second abutting portion of the traveling brake piston 43; 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 traveling 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 this setting, the contact area between the piston and the friction plate is increased, and the braking effect is improved. 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 friction plate and the second connecting portion 42 of the traveling oil cylinder body 41. With this setting, the compactness of the integrated mechanism is further improved.

[0066] In order to make the integrated mechanism more compact, in this embodiment, the first connecting portion 32, the parking oil cylinder body 31, and the limiting portion of the axle housing cooperate to form a friction braking cavity with an opening facing the motor shaft 11. The inner friction plate 25 and the outer friction plate are both located inside the parking oil cylinder body 31. With this setting, the connection effect of the integrated mechanism is improved, and the integration of the traveling brake and the parking brake is further improved.

[0067] In order to improve the durability of the integrated mechanism, in this embodiment, an end plate 26 that can slide axially along the motor shaft 11 is installed between the inner friction plate 25 and the first connecting portion 32 of the parking oil cylinder body 31. The traveling 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. Specifically, the end plate is located inside the friction braking cavity.

[0068] Further preferably, a plurality of guide pins are fixed on the limiting portion of the axle housing 2. The guide pins are located in the friction braking cavity. The plurality of guide pins are located inside the parking oil cylinder body 31. The plurality of guide pins are evenly arranged around the motor shaft 11. The plurality of guide pins all pass through the end plate 26 and the outer friction plate 24. With such an arrangement, the moving paths of the outer friction plate 24 and the end plate 26 are the same, improving the braking stability.

[0069] Further preferably, a separation spring is sleeved on the guide pin. The two ends of the separation spring respectively abut against the end plate 26 and the outer friction plate 24. With such an arrangement, a separation spring is added between the friction plates, reducing the drag torque, reducing the power loss, and improving the transmission efficiency.

[0070] Further preferably, a fifth accommodation groove is formed on the limiting portion of the axle housing 2, and a sixth accommodation groove is formed on the first connecting portion 32 of the parking oil cylinder body 31. The two ends of the guide pin are respectively inserted into the fifth accommodation groove and the sixth accommodation groove and are in a tight fit. With such an arrangement, the positioning between the parking oil cylinder body 31 and the axle housing 2 can be made more accurate through the guide pin, and at the same time, it is also convenient for the assembly of the integrated mechanism.

[0071] In this embodiment, a vent cap 8 communicating with the inside of the axle housing is further installed on the axle housing.

[0072] During the vehicle's travel: The parking oil chamber is filled with oil, the parking brake piston moves away from the friction plate and compresses the parking spring. The driving oil chamber is not filled with oil, the return spring pushes the driving brake piston away from the friction plate, the separation spring pushes the outer friction plate, the inner friction plate and the end plate to separate from each other, and the motor shaft 11 is in a free rotation state.

[0073] When the vehicle brakes during driving, the driving oil chamber is filled with oil, the hydraulic oil pushes the driving brake piston to move. The driving brake piston moves to compress the return spring. The driving brake piston moves to press the end plate, the inner friction plate and the outer friction plate tightly. The end plate moves to compress the separation spring; the end plate, the inner friction plate and the outer friction plate are squeezed against each other to gradually reduce the rotation speed of the motor shaft 11, completing the braking during the vehicle's driving.

[0074] When the vehicle stops, the parking oil chamber is filled with oil, the parking brake piston moves away from the friction plate and compresses the parking spring. The driving oil chamber is not filled with oil, the return spring pushes the driving brake piston away from the friction plate, the separation spring pushes the outer friction plate, the inner friction plate and the end plate to separate from each other, and the motor shaft 11 is in a free rotation state.

[0075] 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. The end plate moves to compress the separation spring; thus, the parking action is completed.

[0076] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples", etc. means 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.

[0077] 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 limiting 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 dual planetary row coaxial electric drive axle assembly integrating wet parking brake and service brake, comprising two sets of symmetrically arranged drive structures, and the two sets of drive structures respectively output power from the left side and the right side; characterized in that: The driving structure comprises a motor (1), a bridge housing (2), a brake mechanism, a wheel hub housing (7), a double planetary gear reduction mechanism and a wheel hub (61) which are arranged in sequence; The motor housing, the bridge housing (2) and the wheel hub housing (7) are arranged in sequence and fixedly connected, and the motor shaft (11), the double planetary gear reduction mechanism and the wheel hub (61) are arranged in sequence and transmission-connected; The double planetary gear reduction mechanism is arranged in the wheel hub shell (7), the wheel hub (61) is rotationally connected to the wheel hub shell (7), the motor shaft (11) passes through the bridge housing (2) and is connected to the double planetary gear reduction mechanism, and the brake mechanism is arranged between the motor shaft (11) and the bridge housing (2).

2. The dual planetary row coaxial electric drive axle assembly integrating wet parking brake and service brake according to claim 1, characterized in that: The double planetary gear reduction mechanism comprises a primary planetary gear and a secondary planetary gear, the motor shaft (11) of the motor (1) is drivingly connected to the primary planetary gear, the primary planetary gear is drivingly connected to the secondary planetary gear, and the secondary planetary gear is drivingly connected to the wheel hub (61).

3. A dual planetary row coaxial electric drive axle assembly integrating wet parking brake and service brake, characterized in that: The first-stage planetary gear row comprises a first-stage inner gear ring (51), a first-stage planet carrier (52), and a plurality of first-stage planetary gears (53); the first-stage inner gear ring (51) is fixed in the wheel hub (61), the plurality of first-stage planetary gears (53) are rotatably mounted on the first-stage planet carrier (52), the plurality of first-stage planetary gears (53) are located inside the first-stage inner gear ring (51), the first-stage planetary gears (53) are meshed with the first-stage inner gear ring (51), the motor shaft (11) extends between the plurality of first-stage planetary gears (53), and the motor shaft (11) is meshed with the first-stage planetary gears (53); The secondary planetary gear row comprises a secondary inner gear ring (55), a secondary planet carrier (56), a sun gear (59) and a plurality of secondary planetary gears (57); the secondary inner gear ring (55) is fixed in a wheel hub (61); the plurality of secondary planetary gears (57) are rotatably mounted on the secondary planet carrier (56); the plurality of secondary planetary gears (57) are located inside the secondary inner gear ring (55); the secondary planetary gears (57) are meshed with the secondary inner gear ring (55); one end of the sun gear (59) extends into an inner hole of the primary planet carrier (52); the sun gear (59) is meshed with the primary planet carrier (52); the other end of the sun gear (59) extends between the plurality of secondary planetary gears (57); the sun gear (59) is meshed with the secondary planetary gears (57); One end of the wheel hub (61) is connected to the wheel hub shell (7) and is fixedly connected to the secondary planet carrier (56), and the wheel hub (61) is meshed with the secondary planet carrier (56).

4. A dual planetary row coaxial electric drive axle assembly integrating wet parking brake and service brake, characterized in that: A plurality of first cantilevers protrude from the first-stage planet carrier (52), the plurality of first-stage planetary gears (53) correspond to the plurality of first cantilevers one by one, and the first-stage planetary gears (53) are rotatably mounted on the first cantilevers; A plurality of second cantilevers are protruded from the secondary planet carrier (56), the plurality of secondary planetary gears (57) correspond to the plurality of second cantilevers one by one, and the secondary planetary gears (57) are rotatably mounted on the second cantilevers.

5. A double planetary gear set coaxial electric drive axle assembly integrating wet parking brake and service brake, characterized in that: The first-stage planetary gear (53) is mounted on the first-stage planetary carrier (52) via a double angular contact ball bearing (54); the second-stage planetary gear (57) is mounted on the second-stage planetary carrier (56) via a roller bearing (58); The wheel hub (61) is mounted on the wheel hub housing (7) via two symmetrically arranged tapered roller bearings (58).

6. The dual planetary row coaxial electric drive axle assembly integrating wet parking brake and service brake according to claim 3, characterized in that: The hub (61) is fixedly connected to the secondary planet carrier (56); wherein, one end of the hub (61) is the input end, and a nut (62) is threadedly connected to the input end. The input end is inserted into the inner hole of the secondary planet carrier (56), and the input end is splined to the secondary planet carrier (56). A pressure plate (63) is connected to the end of the input end by a screw (64). The pressure plate (63) and the nut (62) are respectively arranged on both sides of the secondary planet carrier (56), and the nut (62) and the pressure plate (63) clamp the secondary planet carrier (56).

7. A dual planetary gear set coaxial electric drive axle assembly integrating wet parking brake and service brake, characterized in that: The other end of the hub (61) is a flange end, and the flange end is located outside the hub housing (7); an opening facing the hub housing (7) is provided on the flange end, the end of the hub (61) is inserted into the opening of the flange end, and a fifth oil seal (67) is provided between the hub (61) and the flange end.

8. A dual planetary gear set coaxial electric drive axle assembly integrating wet parking brake and service brake, characterized in that: The braking assembly includes an inner friction plate (25), an outer friction plate (24), a service braking assembly (4) and a parking braking assembly (3). The inner friction plate (25) and the outer friction plate (24) are both sleeved on the motor shaft (11). The inner friction plate (25) is slidably fitted with the motor shaft (11) and axially fixed, and the outer friction plate (24) is slidably fitted with the axle housing (2) and axially fixed. The inner friction plate (25) and the outer friction plate (24) are alternately arranged; The service braking assembly (4) is used to drive the inner friction plate (25) and the outer friction plate (24) to engage to brake the motor shaft (11) in the service state; The parking braking assembly (3) is used to drive the inner friction plate (25) and the outer friction plate (24) to engage to brake the motor shaft (11) in the parking state.

9. A dual planetary row coaxial electric drive axle assembly integrating wet parking brake and service brake, characterized in that: The parking braking assembly (3) includes a parking brake piston (33), a parking oil cylinder body (31) and a parking spring (36) for driving the parking brake piston (33) to reset; the parking oil cylinder body (31) is fixed on the axle housing (2), the parking brake piston (33) is slidably mounted on the parking oil cylinder body (31), and a parking oil chamber (35) is provided between the parking brake piston (33) and the parking oil cylinder body (31); when the parking oil chamber (35) is filled with oil, the piston of the parking brake piston (33) moves away from the inner friction plate (25), separating the inner friction plate (25), the outer friction plate (24) and the axle housing (2) from each other; when the parking oil chamber (35) drains oil, the parking spring (36) pushes the parking brake piston (33), causing the parking brake piston (33) to approach and push the inner friction plate (25), making the inner friction plate (25), the outer friction plate (24) and the axle housing (2) press against each other tightly.

10. A dual planetary row coaxial electric drive axle assembly integrating wet parking brake and service brake, characterized in that: The service brake assembly (4) includes a service brake piston (43), a service brake cylinder block (41), and a return spring (46) for driving the service brake piston (43) to reset; the service brake cylinder block (41) is fixed on the axle housing (2), the service brake piston (43) is slidably mounted on the service brake cylinder block (41), and a service brake oil chamber (44) is provided between the service brake piston (43) and the service brake cylinder block (41); when the service brake oil chamber (44) is filled with oil, the service brake 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 (2) to be pressed tightly together; when the service brake oil chamber (44) drains oil, the return spring (46) pushes the service brake piston (43) away from the inner friction plate (25), causing the inner friction plate (25), the outer friction plate (24), and the axle housing (2) to separate from each other.

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