Hub driving assembly

Abstract

Provided is a hub driving assembly, comprising: an output shaft (600), wherein the output shaft (600) is connected to a hub (700); a speed reduction assembly (200), wherein the speed reduction assembly (200) is drivingly connected to the outer ring of the output shaft (600), and the speed reduction assembly (200) is provided with two connecting surfaces (2001) on two axial sides along the output shaft (600); a brake assembly (300), wherein the brake assembly (300) is fixed to the outer ring of the output shaft (600), and the brake assembly (300) is connected to the connecting surface (2001) of the speed reduction assembly (200) facing the end face of the hub; and an electric motor (100), wherein the electric motor (100) surrounds the output shaft (600), and the electric motor (100) is connected to the connecting surface (2001) of the speed reduction assembly (200) away from the brake assembly (300), an air gap surface (1000) of the electric motor (100) being parallel to said connecting surface (2001). The speed reduction assembly (200), the brake assembly (300) and the electric motor (100) are located within the periphery of the hub (700). The speed reduction assembly, the brake assembly and the electric motor being arranged in the axial direction of the output shaft leads to a reduction in the overall axial size, achieving the advantage of occupying less space overall, allowing for the design of a greater power density, and providing sufficient space for adding a corresponding sealing structure, thus enabling stable and reliable operation of the hub driving assembly.

Description

A wheel hub drive assembly Technical Field

[0001] The present invention relates to the field of wheel hubs, and in particular to a wheel hub drive assembly. Background Art

[0002] The wheel hub drive assembly integrates the motor, reduction system and braking system into the wheel hub. The motor is the core component. The motor uses the rotor shaft and drives the wheel hub to rotate through the reduction system. The braking system achieves wheel hub braking by clamping the rotor shaft of the motor.

[0003] On the one hand, as wheel hub drives become more and more widely used, the requirements for how to increase power and reduce volume are becoming increasingly higher, especially for some specific working conditions. For example, how to make the original structure lighter within the original space, or further improve the power density of the wheel hub drive within the original space has become the goal pursued by the design of the wheel hub drive assembly.

[0004] On the other hand, for wheel hub drive assemblies that cannot get more space in the axial dimension but require greater power, the installation space of the wheel hub drive assembly is extremely limited. In addition to considering the structural size to integrate the motor, deceleration system and braking system into the wheel hub, the overall structural strength and sealing also need to be considered.

[0005] Summary of the Invention

[0006] In order to solve the above problems, the present invention provides a wheel hub drive assembly, which can further miniaturize the wheel hub drive assembly within a limited installation space, achieve increased power sealing, and reasonably design the sealing structure, thereby improving the performance of the wheel hub drive assembly.

[0007] A wheel hub drive assembly, comprising:

[0008] an output shaft connected to the wheel hub;

[0009] a reduction assembly, the reduction assembly being transmission-connected to the outer ring of the output shaft, and the reduction assembly being provided with two connecting surfaces along both axial sides of the output shaft;

[0010] a brake assembly, the brake assembly being fixed to the outer ring of the output shaft and connected to the connection surface of the reduction assembly facing the end surface of the hub;

[0011] A motor is arranged around the output shaft, the motor is connected to the connection surface of the reduction assembly facing away from the brake assembly, the air gap surface of the motor is parallel to the connection surface, and the reduction assembly, the brake assembly and the motor are located within the periphery of the wheel hub.

[0012] As a preferred embodiment, it further comprises a housing, the housing comprising:

[0013] a front housing, the front housing including a front end cover and a reduction housing, the reduction housing being connected to the outer side of the front end cover so as to be connected to the motor on the inner side of the front end cover;

[0014] a sealing shell, the inner side of which is connected to the side of the reduction housing facing away from the front end cover, so as to connect the brake assembly to the outer side of the sealing shell;

[0015] The deceleration assembly is located in the deceleration housing and is sealed between the front end cover and the sealing shell.

[0016] As a preferred embodiment, the brake assembly includes:

[0017] a brake disc, wherein an output shaft flange is provided on the outer ring of the output shaft, the brake disc is fixed between the end face of the wheel hub and the output shaft flange, and the axial sides of the brake disc form braking surfaces;

[0018] At least one brake caliper is fixed on the outer side of the sealing shell and is in braking connection with the two braking surfaces of the brake disc.

[0019] As a preferred embodiment, the housing further comprises:

[0020] A rear shell, the rear shell comprising a rear end cover and a rear motor housing, wherein the inner circle of the rear end cover is extendedly connected to the rear motor housing;

[0021] A side shell connected to the outer ring of the front end cover and the outer ring of the rear end cover;

[0022] The front shell also includes a front motor housing, the inner ring of the front end cover is extended and connected to the front motor housing, the motor is arranged between the front end cover and the rear end cover, the radial inner side of the motor is sealed by the front motor housing and the rear motor housing, and the radial outer side of the motor is sealed by the side shell.

[0023] As a preferred embodiment, the motor includes:

[0024] a front stator, the front stator being fixed on the inner side surface of the front end cover;

[0025] a rear stator, the rear stator being fixed on the inner side surface of the rear end cover;

[0026] A rotor, wherein the rotor is held between the front stator and the rear stator in an air gap manner, and an air gap surface is formed between the rotor and the front stator and the rear stator respectively;

[0027] A rotating shaft is sealed and rotatably connected to the inner ring of the front motor housing and the inner ring of the rear motor housing, respectively. The radial inner side of the rotor extends between the front motor housing and the rear motor housing and is fixedly connected to the rotating shaft.

[0028] As a preferred embodiment, it further includes a hub bearing assembly, the hub bearing assembly comprising:

[0029] an inner bearing ring, the inner bearing ring being fixedly connected to the outer ring of the output shaft;

[0030] An outer bearing ring is fixed between the inner bearing ring and the rotating shaft.

[0031] As a preferred embodiment, the rear shell further includes a connecting shell connected to the outer side of the rear end cover, an outer ring flange is provided on the outer ring of the outer bearing ring, and the outer ring flange is fixed to the connecting shell.

[0032] As a preferred embodiment, it also includes:

[0033] A first bearing, the first bearing being connected between the rear motor housing and the rotating shaft;

[0034] A second bearing, the second bearing being connected between the front motor housing and the rotating shaft;

[0035] A third bearing is connected between the sealed housing and the output shaft.

[0036] As a preferred embodiment, the reduction assembly is a planetary gear reduction assembly, and the planetary carrier of the reduction assembly is limited on both axial sides by the fourth bearing and the sealing shell. The fourth bearing is connected between the front end cover and the planetary carrier, and a stop is provided on the sealing shell for abutting the ring gear of the reduction assembly.

[0037] As a preferred embodiment, it also includes:

[0038] a first oil seal, the first oil seal being disposed between the rear motor housing and the rotating shaft and located outside the first bearing;

[0039] a second oil seal, the second oil seal being disposed between the front motor housing and the rotating shaft and located outside the second bearing;

[0040] a third oil seal, the third oil seal being disposed between the sealing housing and the output shaft and located outside the third bearing;

[0041] A fourth oil seal is located between the wheel hub bearing assembly and the sealing shell, and is arranged between the output shaft and the rotating shaft.

[0042] As a preferred embodiment, a rotary transformer is further included, which is arranged between the rear motor housing and the rotating shaft, and is located between the first bearing and the rotating shaft flange of the rotating shaft.

[0043] Compared with the existing technology, this technical solution has the following advantages:

[0044] First, the two connecting surfaces of the reduction assembly are parallel, and the motor and the brake assembly are respectively connected to the connecting surfaces on both axial sides of the reduction assembly, so that the three are arranged axially along the output shaft, and the air gap surface of the motor and the connecting surface are parallel, so that the motor can be an axial magnetic field motor. The axial magnetic field motor has the characteristics of small axial size, higher power density, lighter weight and greater torque output. It reduces the overall axial size and achieves the advantage of small overall space occupation. A greater power density can be designed, and there is enough space to add corresponding sealing structures to enable the hub drive assembly to operate stably and reliably.

[0045] Second, by aligning the air gap surface of the motor and the connection surface, the motor's torque design only changes in its radial dimension, while its axial dimension remains virtually unchanged. This allows the motor's design space to be increased while minimizing the overall axial dimension of the wheel hub drive assembly. Simultaneously, the brake assembly and the reduction assembly are designed with the radial dimension of the motor as their upper limit, resulting in a reduction assembly with improved transmission performance and a brake assembly with improved braking performance. Furthermore, the motor, reduction assembly, and brake assembly all have flat structures, making the wheel hub drive assembly formed by their assembly flat, allowing for utilization of the space within the wheel hub and placement within the wheel hub.

[0046] The present invention is further described below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] FIG1 is a schematic structural diagram of the wheel hub drive assembly and wheel hub assembly according to the present invention;

[0048] Figure 2 is an enlarged schematic diagram of A in Figure 1;

[0049] FIG3 is a cross-sectional view of the housing of the present invention;

[0050] FIG4 is a front view of the wheel hub drive assembly of the present invention;

[0051] FIG5 is a rear view of the wheel hub drive assembly of the present invention;

[0052] FIG6 is a front view of the housing of the present invention;

[0053] FIG7 is a rear view of the housing of the present invention;

[0054] FIG8 is a schematic diagram of the assembly structure of the housing and the rotating shaft according to the present invention. DETAILED DESCRIPTION

[0055] The following description is intended to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are for illustrative purposes only, and those skilled in the art will readily appreciate other obvious variations. The basic principles of the present invention defined in the following description may be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the present invention.

[0056] As shown in FIG1 , the wheel hub drive assembly includes:

[0057] an output shaft 600 connected to the wheel hub 700;

[0058] A reduction assembly 200, the reduction assembly 200 is drivingly connected to the outer ring of the output shaft 600, and the reduction assembly 600 is provided with two connecting surfaces 2001 along the axial sides of the output shaft 600;

[0059] a brake assembly 300, the brake assembly 300 being fixed to the outer ring of the output shaft 600, and the brake assembly 300 being connected to the connection surface 2001 of the reduction assembly 300 facing the hub end surface;

[0060] A motor 100 is arranged around the output shaft 600. The motor 100 is connected to the connection surface 2001 of the reduction assembly 200 facing away from the brake assembly 300. The air gap surface 1000 of the motor 100 is parallel to the connection surface 2001. The reduction assembly 200, the brake assembly 300 and the motor 100 are located within the periphery of the wheel hub 700.

[0061] The two connecting surfaces 2001 of the reduction assembly 200 are parallel, and the distance between the two connecting surfaces 2001 defines the thickness of the reduction assembly 200. The thickness of the reduction assembly 200 is small, so that the reduction assembly 200 is disc-shaped, and the motor 100 and the brake assembly 300 are respectively connected to the connecting surfaces 2001 on both sides of the axial direction of the reduction assembly 200, so that the three are arranged axially along the output shaft 600, and the air gap surface 1000 of the motor 100 is parallel to the connecting surface 2001, so that the motor 100 can be an axial magnetic field motor. The axial magnetic field motor has the characteristics of small axial size, higher power density, lighter weight and greater torque output. It reduces the overall axial size and achieves the advantage of small overall space occupation. A higher power density can be designed, and there is enough space to add corresponding sealing structures to enable the hub drive assembly to operate stably and reliably. As the output torque of a traditional radial motor increases, its axial dimension also increases. However, the present application utilizes the parallel arrangement of the air gap surface 1000 and the connection surface 2001 of the motor 100, so that when designing the torque, only the radial dimension of the motor 100 changes, while the axial dimension of the motor 100 remains almost unchanged. This shows that the design space of the motor 100 can be correspondingly increased, provided that the overall axial dimension of the wheel hub drive assembly is small. At the same time, the brake assembly 300 and the reduction assembly 200 are designed with the radial dimension of the motor 100 as the upper limit, resulting in a reduction assembly 200 with better transmission effect and a brake assembly 300 with better braking effect. Moreover, the motor 100, the reduction assembly 200, and the brake assembly 300 all have a flat structure, making the wheel hub drive assembly formed by the three components flat, capable of utilizing the space inside the wheel hub 700 and being arranged inside the wheel hub 700.

[0062] As shown in FIG2 , FIG3 , FIG6 and FIG7 , the wheel hub drive assembly further includes a housing 400 , and the housing 400 includes:

[0063] A front housing 410, comprising a front cover 411 and a reduction housing 413, wherein the reduction housing 413 is connected to the outer surface of the front cover 411 to connect the motor 100 to the inner surface of the front cover 411;

[0064] a sealed housing 440 , the inner side of the sealed housing 440 being connected to a side of the reduction housing 413 facing away from the front end cover 411 , so as to connect the brake assembly 300 to the outer side of the sealed housing 440 ;

[0065] The reduction assembly 200 is located in the reduction housing 413 and is sealed between the front end cover 411 and the sealing shell 440 .

[0066] The reduction housing 413 and the front end cover 411 are integrally connected, and the sealing shell 440 and the reduction housing 413 are detachably connected. For example, connecting ears are respectively provided on the outer rings of the sealing shell 440 and the reduction housing 413, and then the corresponding connecting ears of the two are connected by bolts to realize the detachable connection between the sealing shell 440 and the reduction housing 413, so that the reduction assembly 200 can be easily arranged inside the reduction housing 413.

[0067] Furthermore, the inner side surface of the front end cover 411 forms the connecting surface 2001, the outer side surface of the sealing shell 440 also forms the connecting surface 2001, and the two connecting surfaces 2001 are respectively arranged on both sides of the axial direction of the reduction assembly 200, so that the motor 100, the reduction assembly 200 and the brake assembly 300 are overlapped to ensure the advantage of small overall axial size.

[0068] 2 , 3 , 6 and 7 , the housing 400 further includes:

[0069] A rear housing 420, comprising a rear end cover 421 and a rear motor housing 422, wherein the inner circle of the rear end cover 421 is extended and connected to the rear motor housing 422;

[0070] a side shell 430 connected to the outer ring of the front cover 411 and the outer ring of the rear cover 421;

[0071] The front shell 410 also includes a front motor housing 412, and the inner ring of the front end cover 411 is extended and connected to the front motor housing 412. The motor 100 is arranged between the front end cover 411 and the rear end cover 421. The radial inner side of the motor 100 is sealed by the front motor housing 412 and the rear motor housing 422, and the radial outer side of the motor 100 is sealed by the side shell 430.

[0072] The motor 100 is disposed between the inner side of the front cover 411 and the inner side of the rear cover 421. The radially inner side of the motor 100 is sealed by the front motor housing 412 and the rear motor housing 422, and the radially outer side of the motor 100 is sealed by the side shell 430. Since the radially inner side of the motor 100 is sealed by the front motor housing 412 and the rear motor housing 422, and the radially outer side of the motor 100 is sealed by the side shell 430, the motor 100 is sealed within the housing 400. Therefore, coolant can be injected into the cavity of the housing 400 that accommodates the motor 100 to cool the motor 100, thereby preventing the motor 100 from heating up during operation and ensuring reliable operation of the motor 100. Furthermore, the motor 100, the reduction gear assembly 200, and the brake assembly 300 share the housing 400, making the structure more compact and preventing an increase in axial dimensions.

[0073] It is known that the motor 100 may be an axial magnetic field motor, wherein the radial dimension of the axial magnetic field motor is much larger than the axial dimension of the axial magnetic field motor. The motor 100 may further be a dual-stator single-rotor axial magnetic field motor. Referring to FIG. 2 and FIG. 3 , the motor 100 includes:

[0074] A front stator 110 , the front stator 110 being fixed to the inner side surface of the front end cover 411 ;

[0075] The rear stator 120 is fixed to the inner side of the rear end cover 421;

[0076] a rotor 130 , wherein the rotor 130 is held between the front stator 110 and the rear stator 120 in an air gap manner, and an air gap surface 1000 is formed between the rotor 130 and the front stator 110 and the rear stator 120 ;

[0077] The rotating shaft 140 is sealed and rotatably connected to the inner ring of the front motor housing 412 and the inner ring of the rear motor housing 422 respectively. The radial inner side of the rotor 130 extends between the front motor housing 412 and the rear motor housing 422 and is fixedly connected to the rotating shaft 140.

[0078] The front stator 110 can be fixed to the inner side of the front cover 411 via a first bolt 891. The front cover 411 has a countersunk hole, which allows the first bolt 891 to be hidden inside the front cover 411, preventing the first bolt 891 from protruding outward and increasing the size. Similarly, the rear stator 110 can also be fixed to the inner side of the rear cover 421 via a first bolt 891. The rear cover 421 has a countersunk hole for concealing the first bolt 891.

[0079] 2 and 3 , the front stator 110 is annular and accommodated between the front motor housing 412 and the side housing 430. The rear stator 120 is also annular and accommodated between the rear end cover 421 and the side housing 430. The rotor 130 is also annular. The front motor housing 412 and the rear motor housing 422 are correspondingly disposed on either side of the rotor 130 in the axial direction, so that the radial inner side of the rotor 130 is fixedly connected to the upper shaft flange 141 of the outer ring of the rotating shaft 140. The shaft flange 141 and the rear motor housing 422 are disposed on the same side of the rotor 130 in the axial rear direction. It can be seen that the shaft flange 141 is located on the inner side of the rear motor housing 422, and the radial inner side of the rotor 130 can be fixed to the shaft flange 141 by bolts.

[0080] As shown in Figures 4 and 5 , the outer rings of the side shell 430, the front cover 411, and the rear cover 421 are all provided with connecting lugs 440, which can be bolted together for securement. Several connecting lugs 440 are provided on either axial side of the side shell 430, corresponding to the front cover 411 and the rear cover 421. The connecting lugs 440 on either axial side of the side shell 430 correspond one to one, and are spaced circumferentially on each side of the side shell 430. During connection, the front end cover 411 is abutted against one axial side of the side shell 430, and the connecting ear 440 on the front end cover 411 is made to correspond one to one with the connecting ear 440 on that side of the side shell 430, and connected by bolts. Then, the rear end cover 421 is abutted against the other axial side of the side shell 430, and the connecting ear on the rear end cover 421 and the connecting ear on the side where the side shell 430 is connected to the rear end cover 421 are connected by bolts, thereby achieving the fixation between the side shell 430, the front end cover 411 and the rear end cover 421.

[0081] As shown in FIG2 , a first bearing 810 is provided between the rear motor housing 422 and the rotating shaft 140, and a second bearing 830 is provided between the front motor housing 412 and the rotating shaft 140, so that the rotating shaft 140 can rotate smoothly relative to the front housing 410 and the rear housing 420. The first bearing 810 and the second bearing 830 can be deep groove ball bearings or angular contact bearings, etc.

[0082] 2 , a first oil seal 820 is provided between the rear motor housing 422 and the rotating shaft 140 to prevent external debris from entering the cavity of the housing 400 housing the motor 100. A second oil seal 840 is also provided between the front motor housing 412 and the rotating shaft 140 to prevent lubricating oil within the reduction gear assembly 200 from entering the cavity of the housing 400 housing the motor 100.

[0083] Continuing with Figure 2 , the inner rings of the front motor housing 412, the rear motor housing 422, and the outer ring of the rotating shaft 140 all feature stepped configurations to secure the bearings and oil seals. Taking the first bearing 810 as an example, its two axial sides abut between the steps of the inner ring of the rear motor housing 422 and the steps of the outer ring of the rotating shaft 140, respectively, securing the first bearing 810 in position.

[0084] The first oil seal 820 is located on the outside of the first bearing 810, away from the shaft flange 141, while the second oil seal 840 is located on the outside of the second bearing 830, toward the reduction assembly 200. The first oil seal 820 and the first bearing 810 are positioned adjacent to each other, while the second bearing 830 and the second oil seal 840 are positioned adjacent to each other. Both are located inside the motor 100, and utilize a stepped structure to compactly arrange the bearings and oil seals, avoiding the risk of increased bearing size and thereby providing greater design flexibility for the motor, reduction assembly, and brake assembly.

[0085] As shown in Figure 2 , a rotary transformer 890 is further disposed between the rear motor housing 422 and the rotating shaft 140. The rotary transformer 890 is located between the first bearing 810 and the rotating shaft flange 141 of the rotating shaft 140. The rotary transformer 890 is an electromagnetic sensor used to measure the angular displacement and angular velocity of the rotating shaft. As can be seen above, the rotary transformer 890 is also arranged inside the motor and is compactly arranged with the bearings and oil seals, effectively utilizing the space and further reducing the overall footprint.

[0086] As shown in FIG1 to FIG3 , the wheel hub drive assembly further includes a wheel hub bearing assembly 500 , and the wheel hub bearing assembly 500 includes:

[0087] An inner bearing ring 510 , wherein the inner bearing ring 510 is fixedly connected to the outer ring of the output shaft 600 ;

[0088] The outer bearing ring 520 is fixed between the inner bearing ring 510 and the rotating shaft 140 .

[0089] Specifically, the rear housing 420 also includes a connecting housing 423 connected to the outer side of the rear end cover 421. The outer ring of the outer bearing ring 520 is provided with an outer ring flange 521, which is fixed to the connecting housing 423. Referring to Figures 3 and 7, it can be seen that the outer bearing ring 520 is stationary. The outer ring flange 521 and the outer ring of the connecting housing 423 are each provided with connecting lugs. These lugs are bolted together to secure the outer ring flange 521 to the end surface of the connecting housing 423 facing away from the rear end cover 421. Furthermore, the outer ring flange 521 is provided with a plurality of outer ring mounting holes 5211, which can be used to connect a cantilever, thereby supporting the wheel hub drive assembly on the cantilever.

[0090] Referring to Figure 1 , the left end of the outer bearing ring 520 extends outside the connecting housing 423, while the right end of the outer bearing ring 520 is located inside the cavity of the reduction assembly 200, so that the motor 100 and the reduction assembly 200 can be supported on the outer bearing ring 520. The inner bearing ring 510, which rotates relatively to the outer bearing ring 520, can be disposed on the right side of the outer bearing ring 520 and can be locked to the output shaft 600 via a second bolt 620. The second bolt 620 is located on the left side of the output shaft 600 and inside the motor cavity. Furthermore, the inner bearing ring 510 is confined between the step on the outer ring of the output shaft 600 and the second bolt 620.

[0091] As shown in Figures 1 to 3, the right end of the rotating shaft 140 extends into the interior of the reduction housing 413, allowing the reduction assembly 200 to be drivingly connected to the outer ring of the rotating shaft 140 extending into the interior of the reduction housing 413. The reduction assembly 200 described herein may be a planetary reduction assembly. This planetary reduction assembly is shorter in axial length and longer in radial length, allowing it to better match the shape of an axial magnetic field motor to improve its space utilization. Compared to traditional radial motors, the combination of a planetary reduction assembly and an axial magnetic field motor allows the planetary reduction assembly to have a larger radial dimension while maintaining the same volume, enabling the design of a higher transmission ratio and output torque.

[0092] Specifically, the reduction assembly 200 includes a sun gear 210, a ring gear 220 and a planetary gear carrier assembly 230, the sun gear 210 is fixed to the outer ring of the rotating shaft 140, and the two can be interference fit, the ring gear 220 is fixed to the inner ring of the reduction housing 413, and the two can also be interference fit, the planetary gear carrier assembly 230 is transmission-connected between the sun gear 210 and the ring gear 220, wherein the planetary gear carrier assembly 230 includes a plurality of planetary gears meshed between the sun gear 210 and the ring gear 220, and a planetary carrier connecting each of the planetary gears, a fourth bearing 870 is provided between the planetary carrier and the front end cover 411, which is used to axially limit the planetary gear carrier assembly 230 so that the planetary gear carrier assembly 230 can rotate relative to the front shell 410, and the fourth bearing 870 can be a thrust roller bearing, etc. A stop 441 is provided on the sealing shell 440 for abutting against the ring gear 220 of the reduction assembly 200 so that the ring gear 220 is axially limited between the front end cover 411 and the stop 441, thereby limiting the axial sides of the planetary carrier of the reduction assembly 200 by the fourth bearing 870 and the sealing shell 440.

[0093] Referring to Figure 2, the planetary carrier passes through the gap between the rotating shaft 140 and the sealed shell 440 and is connected to the outer ring of the output shaft 600, so that the reduction assembly 200 is transmission-connected to the motor 100 and the output shaft 600 to drive the output shaft 600 and the hub 700 connected to the output shaft 600 to rotate.

[0094] A third oil seal 860 and a fourth oil seal 880 are installed on either side of the planetary carrier that passes through the gap. This seals the cavity of the housing 400 housing the reduction assembly 200 and serves to contain the lubricating oil within the reduction assembly 200. Specifically, the third oil seal 860 is located between the sealing housing 440 and the output shaft 600, while the fourth oil seal 880 is located between the hub bearing assembly 500 and the sealing housing 440, and between the output shaft 140 and the rotating shaft 600. Furthermore, a third bearing 850 may be installed between the sealing housing 440 and the output shaft 600. The third bearing 850 may be a deep groove ball bearing or an angular contact bearing, for example. The third oil seal 860 is positioned adjacent to the third bearing 850 and on the outside of the third bearing 850, away from the fourth oil seal 880.

[0095] As shown in Figure 2, the first bearing 810 and the second bearing 830 are located at approximately the same height, with the second bearing 830 being larger than the first bearing 810 to accommodate the larger and heavier front housing 410 and ensure smooth rotation of the rotating shaft 140 relative to the front housing 410. Furthermore, steps are added to the outer ring of the rotating shaft 140 and the inner ring of the front housing 410 to ensure that the second bearing 830 can be positioned between the rotating shaft 140 and the front housing 410, while also enabling smooth rotation of the rotating shaft 140 relative to the front housing 410 and the rear housing 420. The first oil seal 820 and the second oil seal 840 are also used to seal the cavity in which the motor 100 is installed, preventing oil leakage, for example, preventing oil within the reduction gear assembly 200 from passing through the second oil seal 840 and entering the cavity corresponding to the motor 100. In addition, the first bearing 810 and the second bearing 830 are separated by the rotor 130 and the shaft flange 141, so as to avoid the first bearing 810 and the second bearing 830 being opposite to each other at their installation positions, thereby effectively improving the sealing performance.

[0096] The third bearing 850 is lower than the second bearing 830, meaning it is located inside the second bearing 830. Specifically, the third bearing 850 and the outer bearing ring 520 are located at the same height. This not only effectively utilizes the installation space but also ensures a transmission connection between the reduction assembly 200 and the output shaft 600. Specifically, the planetary carrier of the reduction assembly 200 passes between the rotating shaft 140 and the sealing housing 440 to connect to the output shaft 600. Furthermore, the fourth oil seal 880 prevents oil leakage from the reduction assembly 200. Furthermore, there is a height difference between the third bearing 850 and the second bearing 830, and they are located on either side of the reduction assembly 200, preventing the third bearing 850 and the second bearing 830 from facing each other, further preventing oil leakage.

[0097] As shown in FIG1 , FIG4 and FIG8 , the brake assembly 300 includes:

[0098] a brake disc 310. An output shaft flange 610 is provided on the outer ring of the output shaft 600. The output shaft flange 610 is located outside the sealing shell 440. The brake disc 310 is fixed between the wheel hub end face and the output shaft flange 610. The axial sides of the brake disc 310 form braking surfaces 3100.

[0099] At least one brake caliper 320 is fixed on the outer surface of the sealing shell 440 and is in braking connection with the two braking surfaces 3100 of the brake disc 310 .

[0100] Preferably, the brake caliper 320 is C-shaped, with the brake disc 310 inserted within it, enabling the caliper 320 to engage the two braking surfaces 3100 of the disc 310. Two brake calipers 320 are symmetrically positioned on the outer side of the sealed housing 440. Brake caliper mounting holes 442 are provided on the sealed housing 440, allowing bolts to secure the brake caliper 320 to the outer side of the sealed housing 440. Furthermore, several reinforcing ribs 441 are provided on the outer side of the sealed housing 440 to ensure structural strength and reliable product operation.

[0101] From the above, it can be seen that the brake assembly 300 also has a disc-shaped structure, and the braking surface 3100 of the brake assembly 300 can be parallel to the connecting surface 2001, so that the motor 100, the deceleration assembly 200 and the brake assembly 300 all have a flat structure, which can achieve the effect of reducing the overall occupied space.

[0102] 8 , the output shaft flange 610 is provided with hub bolts 611 for connecting to the hub.

[0103] As shown in Figure 5, the rear end cover 421 is provided with an inlet and outlet 4211 communicating with the interior of the motor cavity, so that coolant can be introduced into or out of the motor cavity through the inlet and outlet 4211. In addition, the rear end cover 421 can also be provided with a three-phase outgoing line structure 4212 to correspond to the stator winding outgoing line.

[0104] In summary, the two connecting surfaces 2001 of the reduction assembly 200 are parallel, and the distance between the two connecting surfaces 2001 defines the thickness of the reduction assembly 200. The thickness of the reduction assembly 200 is small, so that the reduction assembly 200 is disc-shaped, and the motor 100 and the brake assembly 300 are respectively connected to the connecting surfaces 2001 on both sides of the axial direction of the reduction assembly 200, so that the three are arranged axially along the output shaft 600, and the air gap surface 1000 of the motor 100 is parallel to the connecting surface 2001, so that the motor 100 can be an axial magnetic field motor. The axial magnetic field motor has the characteristics of small axial size, higher power density, lighter weight and greater torque output. It reduces the overall axial size and achieves the advantage of small overall space occupation. A higher power density can be designed, and there is enough space to add corresponding sealing structures to enable the hub drive assembly to operate stably and reliably. Traditional radial motors increase their axial dimensions as output torque increases. However, the present invention utilizes parallel alignment between the air gap surface 1000 and the connection surface 2001 of the motor 100, ensuring that only the radial dimension of the motor 100 changes during torque design, while the axial dimension of the motor 100 remains virtually unchanged. This significantly increases the design space of the motor 100 while minimizing the overall axial dimension of the wheel hub drive assembly. Furthermore, the brake assembly 300 and the reduction assembly 200 are designed with the radial dimension of the motor 100 as the upper limit, resulting in a more efficient reduction assembly 200 and a more effective brake assembly 300. Furthermore, the motor 100, reduction assembly 200, and brake assembly 300 all have flat structures, resulting in a flat wheel hub drive assembly formed by their assembly, utilizing the space within the wheel hub 700 and being arranged therein. The bearings and oil seals are compactly arranged inside the motor and reduction assembly, effectively utilizing the space and further reducing the overall footprint.

[0105] The embodiments described above are only used to illustrate the technical ideas and features of the present invention. Their purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. The scope of the patent application of the present invention cannot be limited by these embodiments alone. That is, any equivalent changes or modifications made according to the spirit disclosed by the present invention still fall within the patent scope of the present invention.

Claims

1. A wheel hub drive assembly, characterized in that: include: An output shaft (600), the output shaft (600) is connected to the wheel hub (700); A reduction assembly (200), the reduction assembly (200) being drivingly connected to the outer ring of the output shaft (600), and the reduction assembly (600) being provided with two connecting surfaces (2001) along both sides of the axial direction of the output shaft (600); a brake assembly (300), the brake assembly (300) being fixed to the outer ring of the output shaft (600), and the brake assembly (300) being connected to a connection surface (2001) of the reduction assembly (300) facing the wheel hub end surface; A motor (100) is disposed around the output shaft (600), the motor (100) is connected to a connection surface (2001) of the reduction assembly (200) that faces away from the brake assembly (300), an air gap surface (1000) of the motor (100) is parallel to the connection surface (2001), and the reduction assembly (200), the brake assembly (300) and the motor (100) are located within the periphery of the wheel hub (700).

2. The wheel hub drive assembly according to claim 1, characterized in that: The device further comprises a housing (400), wherein the housing (400) comprises: a front shell (410), the front shell (410) comprising a front end cover (411) and a reduction housing (413), the reduction housing (413) being connected to the outer side of the front end cover (411) so as to be connected to the motor (100) on the inner side of the front end cover (411); a sealing shell (440), the inner side of the sealing shell (440) being connected to a side of the reduction housing (413) facing away from the front end cover (411), so as to connect the brake assembly (300) to the outer side of the sealing shell (440); The reduction assembly (200) is located in the reduction housing (413) and is sealed between the front end cover (411) and the sealing shell (440).

3. The wheel hub drive assembly according to claim 2, characterized in that: The brake assembly (300) comprises: a brake disc (310), wherein an output shaft flange (610) is arranged on the outer ring of the output shaft (600), the brake disc (310) is abutted and fixed between the wheel hub end surface and the output shaft flange (610), and braking surfaces (3100) are formed on both axial sides of the brake disc (310); At least one brake caliper (320), the brake caliper (320) being fixed on the outer side of the sealing shell (440) and being brake-connected to the two braking surfaces (3100) of the brake disc (310).

4. The wheel hub drive assembly according to claim 2, characterized in that: The housing (400) further comprises: A rear shell (420), the rear shell (420) comprising a rear end cover (421) and a rear motor housing (422), the inner circle of the rear end cover (421) extending and connected to the rear motor housing (422); A side shell (430), the side shell (430) is connected to the outer ring of the front end cover (411) and the rear end cover (421) The outer ring; The front shell (410) further includes a front motor housing (412), the inner ring of the front end cover (411) is extendedly connected to the front motor housing (412), the motor (100) is arranged between the front end cover (411) and the rear end cover (421), the radial inner side of the motor (100) is sealed by the front motor housing (412) and the rear motor housing (422), and the radial outer side of the motor (100) is sealed by the side shell (430).

5. The wheel hub drive assembly according to claim 4, characterized in that: The motor (100) comprises: A front stator (110), the front stator (110) being fixed on the inner side surface of the front end cover (411); A rear stator (120), wherein the rear stator (120) is fixed on the inner side surface of the rear end cover (421); a rotor (130), the rotor (130) being held between the front stator (110) and the rear stator (120) in an air gap manner, and an air gap surface (1000) being formed between the rotor (130) and the front stator (110) and the rear stator (120); A rotating shaft (140) is sealed and rotatably connected to the inner ring of the front motor housing (412) and the inner ring of the rear motor housing (422), respectively; the radial inner side of the rotor (130) extends between the front motor housing (412) and the rear motor housing (422), and is fixedly connected to the rotating shaft (140).

6. The wheel hub drive assembly according to claim 5, characterized in that: Also included is a wheel hub bearing assembly (500), the wheel hub bearing assembly (500) comprising: An inner bearing ring (510), the inner bearing ring (510) being fixedly connected to the outer ring of the output shaft (600); An outer bearing ring (520) is fixed between the inner bearing ring (510) and the rotating shaft (140).

7. The wheel hub drive assembly according to claim 6, characterized in that: The rear shell (420) also includes a connecting shell (423), the connecting shell (423) is connected to the outer side surface of the rear end cover (421), and an outer ring flange (521) is provided on the outer ring of the outer bearing ring (520), and the outer ring flange (521) is fixed on the connecting shell (423).

8. The wheel hub drive assembly according to claim 5, characterized in that: Also includes: A first bearing (810), the first bearing (810) being connected between the rear motor housing (422) and the rotating shaft (140); a second bearing (830), the second bearing (830) being connected between the front motor housing (412) and the rotating shaft (140); A third bearing (850), wherein the third bearing (850) is connected between the sealing housing (440) and the output shaft (600).

9. The wheel hub drive assembly according to claim 2, characterized in that: The reduction assembly (200) is a planetary gear reduction assembly, and the planet carrier of the reduction assembly (200) is limited on both axial sides by the fourth bearing (870) and the sealing shell (440). The fourth bearing (870) is connected between the front end cover (411) and the planet carrier. The sealing shell (440) is provided with a stopper (441) for abutting against the ring gear (220) of the reduction assembly (200).

10. The wheel hub drive assembly according to claim 6, characterized in that: Also includes: a first oil seal (820), the first oil seal (820) being disposed between the rear motor housing (422) and the rotating shaft (140) and being located outside the first bearing (810); a second oil seal (840), the second oil seal (840) being disposed between the front motor housing (412) and the rotating shaft (140) and being located outside the second bearing (830); a third oil seal (860), the third oil seal (860) being disposed between the sealing housing (440) and the output shaft (600) and being located outside the third bearing (850); A fourth oil seal (880), the fourth oil seal (880) is located between the wheel hub bearing assembly (500) and the sealing shell (440), and is arranged between the output shaft (140) and the rotating shaft (600).

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