A wheel hub drive assembly

Abstract

The present invention provides a wheel hub drive assembly, including an output shaft, a motor, a reduction assembly and a brake assembly, wherein the reduction assembly is transmission-connected to the outer ring of the output shaft, and the reduction assembly is provided with two connection surfaces along the axial sides of the output shaft; the brake assembly is fixed to the outer ring of the output shaft, and the brake assembly is connected to the connection surface of the reduction assembly facing the end surface of the wheel hub; the motor is arranged outside the output shaft, and the motor is connected to the connection surface of the reduction assembly facing away from the brake assembly, and 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 inside the periphery of the wheel hub. The three are arranged along the axial direction of the output shaft, the overall axial size is reduced, and the overall space occupation is small, a higher power density can be designed, and there is enough space to add a corresponding sealing structure, so that the wheel hub drive assembly can operate stably and reliably.

Description

Technical Field

[0001] The 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, of which 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 motor's rotor shaft.

[0003] On the one hand, with the increasing application of wheel hub drives, the requirements for how to increase power and reduce volume are becoming higher and 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, reduction system and braking system into the wheel hub, it is also necessary to consider the overall structural strength and sealing. Summary of the invention

[0005] 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.

[0006] A wheel hub drive assembly, comprising:

[0007] an output shaft connected to the wheel hub;

[0008] A reduction assembly, the reduction assembly is drivingly connected to the outer ring of the output shaft, and the reduction assembly is provided with two connecting surfaces along the axial sides of the output shaft;

[0009] 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 wheel hub;

[0010] A motor is arranged outside 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 inside the periphery of the wheel hub.

[0011] As a preferred embodiment, it also includes a housing, the housing comprising:

[0012] A front shell, the front shell includes a front cover and a reduction housing, the reduction housing is connected to the outer side of the front cover to connect the motor on the inner side of the front cover;

[0013] a sealing shell, the inner side of which is connected to the side of the reduction housing away from the front end cover, so as to connect the brake assembly to the outer side of the sealing shell;

[0014] The reduction assembly is located in the reduction housing and is sealed between the front end cover and the sealing shell.

[0015] As a preferred embodiment, the brake assembly includes:

[0016] A brake disc, wherein an output shaft flange is arranged on the outer ring of the output shaft, the brake disc is abutted and fixed between the end face of the wheel hub and the output shaft flange, and braking surfaces are formed on both axial sides of the brake disc;

[0017] At least one brake caliper is fixed on the outer side of the sealing shell and is brake-connected to the two brake surfaces of the brake disc.

[0018] As a preferred embodiment, the housing further comprises:

[0019] A rear shell, the rear shell comprising a rear end cover and a rear motor housing, the inner circle of the rear end cover extendingly connected to the rear motor housing;

[0020] A side shell connected to the outer ring of the front end cover and the outer ring of the rear end cover;

[0021] The front shell also includes a front motor housing, the inner circle of the front end cover is extended and connected with 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.

[0022] As a preferred embodiment, the motor comprises:

[0023] A front stator, the front stator being fixed on the inner side surface of the front end cover;

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

[0025] 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;

[0026] A rotating shaft, which is respectively sealed and rotatably connected to the inner rings of the front motor housing and the rear motor housing. The radially inner side of the rotor extends between the front motor housing and the rear motor housing and is fixedly connected to the rotating shaft.

[0027] As a preferred embodiment, it further includes a hub bearing assembly, and the hub bearing assembly includes:

[0028] An inner bearing ring, which is fixedly connected to the outer ring of the output shaft;

[0029] An outer bearing ring, which is fixed between the inner bearing ring and the rotating shaft.

[0030] As a preferred embodiment, the rear housing further includes a connecting housing, which is 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 housing.

[0031] As a preferred embodiment, it further includes:

[0032] A first bearing, which is connected between the rear motor housing and the rotating shaft;

[0033] A second bearing, which is connected between the front motor housing and the rotating shaft;

[0034] A third bearing, which is connected between the sealing housing and the output shaft.

[0035] As a preferred embodiment, the reduction assembly is a planetary gear reduction assembly. The two axial sides of the planet carrier of the reduction assembly are limited by the fourth bearing and the sealing housing. The fourth bearing is connected between the front end cover and the planet carrier. A stop is provided on the sealing housing for abutting against the gear ring of the reduction assembly.

[0036] As a preferred embodiment, it further includes:

[0037] A first oil seal, which is arranged between the rear motor housing and the rotating shaft and is located outside the first bearing;

[0038] A second oil seal, which is arranged between the front motor housing and the rotating shaft and is located outside the second bearing;

[0039] A third oil seal, which is arranged between the sealing housing and the output shaft and is located outside the third bearing;

[0040] A fourth oil seal, which is located between the hub bearing assembly and the sealing housing and is arranged between the output shaft and the rotating shaft.

[0041] As a preferred embodiment, it further includes a resolver, which is arranged between the rear motor housing and the rotating shaft and is located between the first bearing and the shaft flange of the rotating shaft.

[0042] Compared with the prior art, the technical solution of the present invention has the following advantages:

[0043] First, the two connection surfaces of the deceleration assembly are parallel to each other. The motor and the braking assembly are respectively connected to the connection surfaces on both axial sides of the deceleration assembly, so that the three are arranged along the axial direction of the output shaft. And the air-gap surface of the motor is parallel to the connection surface, so that the motor can be an axial magnetic field motor. The axial magnetic field motor has the characteristics of small axial dimension, higher power density, lighter weight and larger torque output, etc., reducing the overall axial dimension, achieving the advantage of small overall occupied space, being able to design a larger power density, and having enough space to add corresponding sealing structures, so that the hub drive assembly can operate stably and reliably.

[0044] Second, by making the air-gap surface of the motor parallel to the connection surface, when designing the torque of the motor, only its radial dimension changes, while the axial dimension of the motor hardly changes. It can be seen that on the premise of small overall axial dimension occupation of the hub drive assembly, the design space of the motor can be increased accordingly. At the same time, the braking assembly and the deceleration assembly are designed with the radial dimension of the motor as the upper limit to design a deceleration assembly with better transmission effect and a braking assembly with better braking effect. And the motor, the deceleration assembly and the braking assembly are all in a flat structure, so that the hub drive assembly formed by assembling the three is flat, can utilize the space inside the hub, and can be arranged inside the hub.

[0045] The present invention will be further described below with reference to the accompanying drawings and embodiments. Description of the Drawings

[0046] Figure 1 It is a schematic structural diagram of the hub drive assembly and the hub assembly of the present invention;

[0047] Figure 2 is Figure 1 an enlarged schematic diagram of A in

[0048] Figure 3 It is a cross-sectional view of the housing of the present invention;

[0049] Figure 4 It is a front view of the hub drive assembly of the present invention;

[0050] Figure 5 It is a rear view of the hub drive assembly of the present invention;

[0051] Figure 6 It is a front view of the housing of the present invention;

[0052] Figure 7 A rear view of the housing of the present invention;

[0053] Figure 8 It is a schematic diagram of the assembly structure of the housing and the rotating shaft of the present invention. DETAILED DESCRIPTION

[0054] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles of the present invention defined in the following description can be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not deviate from the spirit and scope of the present invention.

[0055] like Figure 1 As shown, the wheel hub drive assembly includes:

[0056] an output shaft 600 , wherein the output shaft 600 is connected to the wheel hub 700 ;

[0057] A reduction assembly 200, the reduction assembly 200 is drivingly connected to the outer ring of the output shaft 600, and the reduction assembly 200 is provided with two connecting surfaces 2001 along the axial sides of the output shaft 600;

[0058] A brake assembly 300, the brake assembly 300 is fixed to the outer ring of the output shaft 600, and the brake assembly 300 is connected to the connection surface 2001 of the reduction assembly 200 facing the hub end surface;

[0059] A motor 100 is arranged around the output shaft 600, and 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.

[0060] The two connecting surfaces 2001 of the deceleration assembly 200 are parallel to each other, and the distance between the two connecting surfaces 2001 defines the thickness of the deceleration assembly 200. The thickness of the deceleration assembly 200 is small, so that the deceleration assembly 200 is in a disc shape. The motor 100 and the braking assembly 300 are respectively connected to the connecting surfaces 2001 on both axial sides of the deceleration 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-flux motor. The axial-flux motor has the characteristics of small axial size, higher power density, lighter mass and larger torque output, etc., reducing the overall axial size and achieving the advantage of small overall occupied space. It can design a larger power density, and there is enough space to add corresponding sealing structures, so that the hub drive assembly can operate stably and reliably. For traditional radial motors, as the output torque increases, their axial size also becomes longer. In this application, by making the air-gap surface 1000 of the motor 100 parallel to the connecting surface 2001, when designing the torque of the motor 100, only its radial size changes, and the axial size of the motor 100 hardly changes. It can be seen that on the premise of small overall axial size occupation of the hub drive assembly, the design space of the motor 100 can be increased correspondingly. At the same time, the braking assembly 300 and the deceleration assembly 200 are designed with the radial size of the motor 100 as the upper limit to design a deceleration assembly 200 with better transmission effect and a braking assembly 300 with better braking effect. And the motor 100, the deceleration assembly 200 and the braking assembly 300 are all in a flat structure, so that the hub drive assembly formed by assembling the three is flat, can utilize the space inside the hub 700, and is arranged inside the hub 700.

[0061] As Figure 2 , Figure 3 , Figure 6 and Figure 7 shown, the hub drive assembly further includes a housing 400, and the housing 400 includes:

[0062] A front housing 410, the front housing 410 includes a front end cover 411 and a deceleration housing 413. The deceleration housing 413 is connected to the outer side surface of the front end cover 411 to connect the motor 100 on the inner side surface of the front end cover 411;

[0063] A sealing housing 440, the inner side surface of the sealing housing 440 is connected to the side of the deceleration housing 413 facing away from the front end cover 411 to connect the braking assembly 300 on the outer side surface of the sealing housing 440;

[0064] The deceleration assembly 200 is located within the deceleration housing 413 and is hermetically disposed between the front end cover 411 and the seal housing 440.

[0065] The deceleration housing 413 and the front end cover 411 are integrally connected, while the seal housing 440 is detachably connected to the deceleration housing 413. For example, connection ears are respectively provided on the outer rings of the seal housing 440 and the deceleration housing 413, and then the corresponding connection ears of the two are connected by bolts to achieve the detachable connection between the seal housing 440 and the deceleration housing 413, which facilitates the arrangement of the deceleration assembly 200 inside the deceleration housing 413.

[0066] Further, the inner side surface of the front end cover 411 forms the connection surface 2001, and the outer side surface of the seal housing 440 also forms the connection surface 2001. And the two connection surfaces 2001 are respectively disposed on both sides of the deceleration assembly 200 in the axial direction, so that the motor 100, the deceleration assembly 200, and the braking assembly 300 are stacked, to ensure the advantage of a small overall axial dimension.

[0067] Reference Figure 2 、 Figure 3 、 Figure 6 and Figure 7 , the housing 400 further includes:

[0068] A rear housing 420, the rear housing 420 includes a rear end cover 421 and a rear motor housing 422, and the inner ring of the rear end cover 421 extends and is connected to the rear motor housing 422;

[0069] A side housing 430, the side housing 430 is connected to the outer ring of the front end cover 411 and the outer ring of the rear end cover 421;

[0070] The front housing 410 further includes a front motor housing 412, the inner ring of the front end cover 411 extends and is connected to the front motor housing 412, the motor 100 is disposed 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 housing 430.

[0071] The motor 100 is disposed between the inner side surfaces of the front end cover 411 and the rear end 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 housing 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 housing 430, such that the motor 100 is sealed inside the housing 400, coolant can be injected into the cavity of the housing 400 that houses the motor 100 to cool the motor 100, avoiding temperature rise during the operation of the motor 100, and thus ensuring the reliable operation of the motor 100. Also, the motor 100, the reduction assembly 200, and the braking assembly 300 share the housing 400, making the structure more compact and preventing the axial dimension from increasing.

[0072] It is known that the motor 100 can 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 can further be a double-stator single-rotor axial magnetic field motor. Referring to Figure 2 and Figure 3 , the motor 100 includes:

[0073] A front stator 110, which is fixed to the inner side surface of the front end cover 411;

[0074] A rear stator 120, which is fixed to the inner side surface of the rear end cover 421;

[0075] A rotor 130, which is held in an air gap between the front stator 110 and the rear stator 120, and an air gap surface 1000 is formed between the rotor 130 and the front stator 110 and the rear stator 120 respectively;

[0076] A rotating shaft 140, which is respectively sealed and rotatably connected to the inner rings of the front motor housing 412 and the rear motor housing 422. The radially 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.

[0077] The front stator 110 can be fixed to the inner side surface of the front end cover 411 by a first bolt 891. The front end cover 411 is provided with a counterbore such that the first bolt 891 is hidden inside the front end cover 411, avoiding the protrusion of the first bolt 891 and increasing the volume. Similarly, the rear stator 110 can also be fixed to the inner side surface of the rear end cover 421 by the first bolt 891, and the rear end cover 421 is provided with a counterbore for hiding the first bolt 891.

[0078] Reference Figure 2 and Figure 3 As described above, the front stator 110 is annular, and the front stator 110 is accommodated between the front motor housing 412 and the side housing 430. The rear stator 120 is also annular and is 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 arranged on both axial sides of the rotor 130, so that the inner ring of the rotor 130 is fixedly connected to the upper shaft flange 141 on the outer ring of the rotating shaft 140. The shaft flange 141 and the rear motor housing 422 are arranged on the same side behind the rotor 130 axially. It can be seen that the shaft flange 141 is located inside the rear motor housing 422, and the inner ring of the rotor 130 can be fixed to the shaft flange 141 by bolts.

[0079] As Figure 4 and Figure 5 shown, connection ears 440 are provided on the outer rings of the side housing 430, the front end cover 411 and the rear end cover 421, and they can be bolted to the connection ears 440 to achieve fixation. Among them, a plurality of the connection ears 440 are respectively provided on both axial sides of the side housing 430, and are respectively correspondingly connected to the front end cover 411 and the rear end cover 421. The connection ears 440 on both axial sides of the side housing 430 correspond to each other one by one, and the connection ears 440 on each side of the side housing 430 are arranged at circumferential intervals. When connecting, the front end cover 411 is abutted against one axial side of the side housing 430, and the connection ears 440 on the front end cover 411 are made to correspond to the connection ears 440 on this side of the side housing 430 one by one and are bolted. Then, the rear end cover 421 is abutted against the other axial side of the side housing 430, and the connection ears on the rear end cover 421 and the connection ears on the side housing 430 on the side where the rear end cover 421 is connected are bolted, thereby realizing the fixation among the side housing 430, the front end cover 411 and the rear end cover 421.

[0080] As Figure 2 shown, 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.

[0081] Reference Figure 2, a first oil seal 820 is provided between the rear motor housing 422 and the rotating shaft 140 for isolating external flying debris from entering the cavity inside the housing 400 where the motor 100 is accommodated. A second oil seal 840 is also provided between the front motor housing 412 and the rotating shaft 140 for isolating the lubricating oil in the speed reduction assembly 200 from entering the cavity inside the housing 400 where the motor 100 is accommodated.

[0082] Continue to refer to Figure 2 , the inner rings of the front motor housing 412, the inner rings of the rear motor housing 422, and the outer ring of the rotating shaft 140 are all stepped to achieve the function of limiting and fixing the bearings and oil seals. Taking the first bearing 810 as an example, both axial sides of the first bearing 810 are respectively abutted between the step of the inner ring of the rear motor housing 422 and the step of the outer ring of the rotating shaft 140 to limit and fix the first bearing 810.

[0083] The first oil seal 820 is located outside the first bearing 810 away from the rotating shaft flange 141, while the second oil seal 840 is located outside the second bearing 830 facing the speed reduction assembly 200. The first oil seal 820 and the first bearing 810 are arranged adjacent to each other, and the second bearing 830 and the second oil seal 840 are arranged adjacent to each other, and both are located inside the motor 100. By using the stepped structure, the bearings and oil seals are compactly arranged, avoiding the risk of increasing the bearing size, and thus providing a larger design space for the motor, the speed reduction assembly, and the braking assembly.

[0084] As Figure 2 shown, a resolver 890 is also provided between the rear motor housing 422 and the rotating shaft 140. The resolver 890 is located between the first bearing 810 and the rotating shaft flange 141 of the rotating shaft 140. The resolver 890 is an electromagnetic sensor for measuring the angular displacement and angular velocity of the rotating shaft. As can be seen from the above, the resolver 890 is also arranged inside the motor and is compactly arranged with the bearings and oil seals, that is, making full use of the space to further reduce the overall occupied space.

[0085] As Figures 1 to 3 shown, the hub drive assembly further includes a hub bearing assembly 500, and the hub bearing assembly 500 includes:

[0086] an inner bearing ring 510 fixedly connected to the outer ring of the output shaft 600;

[0087] an outer bearing ring 520 fixed between the inner bearing ring 510 and the rotating shaft 140.

[0088] Specifically, the rear housing 420 further includes a connecting housing 423 which is connected to the outer side surface of the rear end cover 421. 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 to the connecting housing 423. Refer to Figure 3 and 7 . It can be seen that the outer bearing ring 520 is fixed and immovable. Connecting ears are respectively provided on the outer ring of the outer ring flange 521 and the outer ring of the connecting housing 423, and the connecting ears of the two are connected by bolts to fix the outer ring flange 521 on the end surface of the connecting housing 423 facing away from the rear end cover 421. In addition, a plurality of outer ring mounting holes 5211 are provided on the outer ring flange 521, which can be used to connect the cantilever so that the hub drive assembly is supported on the cantilever.

[0089] Refer to Figure 1 . The left end of the outer bearing ring 520 extends to the outside of the connecting housing 423, while the right end of the outer bearing ring 520 is located inside the cavity of the speed reduction assembly 200, so that the motor 100 and the speed reduction assembly 200 can be supported on the outer bearing ring 520. The relatively rotatable inner bearing ring 510 can be arranged on the right side of the outer bearing ring 520 and can be locked on the output shaft 600 by the second bolt 620. The second bolt 620 is located on the left side of the output shaft 600 and inside the motor cavity. Further, the inner bearing ring 510 is limited between the step on the outer circle of the output shaft 600 and the second bolt 620.

[0090] As Figures 1 to 3 shown, the right end of the rotating shaft 140 extends into the speed reduction housing 413, so that the speed reduction assembly 200 can be drivingly connected to the outer circle of the rotating shaft 140 extending into the speed reduction housing 413. The speed reduction assembly 200 can be a planetary gear speed reduction assembly. The planetary gear speed reduction assembly is shorter in axial length and longer in radial length, and its shape can better match that of the axial magnetic field motor to improve its space utilization rate. Compared with the traditional radial motor, the combination of the planetary gear speed reduction assembly and the axial magnetic field motor can, on the premise of maintaining the same volume, have a larger radial dimension for the planetary gear speed reduction assembly, and a higher transmission ratio and output torque can be designed.

[0091] Specifically, the reduction assembly 200 includes a sun gear 210, a ring gear 220 and a planetary wheel carrier assembly 230, wherein the sun gear 210 is fixed to the outer ring of the rotating shaft 140, and the two can be interference fit, and the ring gear 220 is fixed to the inner ring of the reduction housing 413, and the two can also be interference fit, and the planetary wheel carrier assembly 230 is transmission-connected between the sun gear 210 and the ring gear 220, wherein the planetary wheel carrier assembly 230 includes a plurality of planetary wheels meshing between the sun gear 210 and the ring gear 220, and a planetary carrier connecting each of the planetary wheels, and a fourth bearing 870 is arranged between the planetary carrier and the front end cover 411, which is used to axially limit the planetary wheel carrier assembly 230 so that the planetary wheel carrier assembly 230 can rotate relative to the front housing 410, and the fourth bearing 870 can be a thrust roller bearing, etc. A stopper 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 stopper 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 .

[0092] refer to Figure 2 The planet carrier passes through the gap between the rotating shaft 140 and the sealing 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.

[0093] A third oil seal 860 and a fourth oil seal 880 are arranged on both sides of the planet carrier passing through the gap, so that the cavity of the housing 400 in which the reduction assembly 200 is installed can be sealed, and is used to seal the lubricating oil in the reduction assembly 200. Specifically, the third oil seal 860 is arranged between the sealing shell 440 and the output shaft 600, and 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 600 and the rotating shaft 140. In addition, a third bearing 850 can be arranged between the sealing shell 440 and the output shaft 600, and the third bearing 850 can be a deep groove ball bearing or an angular contact bearing, etc. The third oil seal 860 is arranged adjacent to the third bearing 850, and is located on the outer side of the third bearing 850 away from the fourth oil seal 880.

[0094] like Figure 2As shown, the first bearing 810 and the second bearing 830 are generally at the same height, and the size of the second bearing 830 is larger than that of the first bearing 810 to fit the front shell 410 with a larger volume and heavier mass, ensuring that the rotating shaft 140 can rotate smoothly relative to the front shell 410. And by adding steps on the outer ring of the rotating shaft 140 and the inner ring of the front shell 410, it is ensured that the second bearing 830 can be arranged between the rotating shaft 140 and the front shell 410, and at the same time, the rotating shaft 140 can rotate smoothly relative to the front shell 410 and the rear shell 420. The first oil seal 820 and the second oil seal 840 are also used to achieve the sealing of the cavity where the motor 100 is installed to prevent oil leakage. For example, to prevent the oil in the reduction assembly 200 from entering the cavity corresponding to the motor 100 through the second oil seal 840. In addition, the first bearing 810 and the second bearing 830 are separated by the rotor 130 and the rotating shaft flange 141, avoiding the relative position between the installation positions of the first bearing 810 and the second bearing 830, and thus effectively improving the sealing performance.

[0095] The height of the third bearing 850 is lower than that of the second bearing 830, that is, the third bearing 850 is located inside the second bearing 830. Specifically, the third bearing 850 and the outer bearing ring 520 are at the same height, which not only makes reasonable use of the installation space but also realizes the transmission connection between the reduction assembly 200 and the output shaft 600. That is, the planet carrier of the reduction assembly 200 passes between the rotating shaft 140 and the sealing shell 440 to connect the output shaft 600. The fourth oil seal 880 is also used to prevent oil leakage from the reduction assembly 200. In addition, there is a height difference between the third bearing 850 and the second bearing 830, and they are respectively arranged on both sides of the reduction assembly 200, avoiding the relative position between the installation positions of the third bearing 850 and the second bearing 830, and further preventing oil leakage.

[0096] As Figure 1 、 Figure 4 and Figure 8 shown, the braking assembly 300 includes:

[0097] 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 fixedly abutted between the hub end face and the output shaft flange 610, and braking surfaces 3100 are formed on both axial sides of the brake disc 310;

[0098] At least one brake caliper 320, the brake caliper 320 is fixed on the outer side surface of the sealing shell 440 and is in braking connection with the two braking surfaces 3100 of the brake disc 310.

[0099] Preferably, the brake caliper 320 is C-shaped, and the brake disc 310 is inserted into the brake caliper 320 so that the brake caliper 320 is brakingly connected to the two braking surfaces 3100 of the brake disc 310 respectively. The number of the brake calipers 320 is two, and they are symmetrically arranged on the outer side surface of the sealing housing 440. Moreover, a brake caliper mounting hole 442 is provided on the sealing housing 440, and the brake caliper 320 is fixed to the outer side surface of the sealing housing 440 by bolts. In addition, a plurality of reinforcing ribs 441 are provided on the outer side surface of the sealing housing 440 to ensure the structural strength and the reliable operation of the product.

[0100] As can be seen from the above, the brake assembly 300 is also in a disc-shaped structure, and the braking surface 3100 of the brake assembly 300 can be parallel to the connecting surface 2001. In this way, the motor 100, the reduction assembly 200 and the brake assembly 300 are all in a flat structure, which can achieve the effect of reducing the overall occupied space.

[0101] Reference Figure 8 , a hub bolt 611 for connecting a hub is provided on the output shaft flange 610.

[0102] Such as Figure 5 As shown, an inlet / outlet 4211 communicating with the inside of the motor cavity is provided on the rear end cover 421 to introduce or lead out the coolant into or from the motor cavity through the inlet / outlet 4211. In addition, a three-phase lead-out structure 4212 may be provided on the rear end cover 421 to correspond to the lead-out of the stator winding.

[0103] In summary, the two connecting surfaces 2001 of the speed reduction assembly 200 are parallel, and the distance between the two connecting surfaces 2001 defines the thickness of the speed reduction assembly 200. The thickness of the speed reduction assembly 200 is small, so that the speed reduction assembly 200 is disk-shaped. The motor 100 and the braking assembly 300 are respectively connected to the connecting surfaces 2001 on both axial sides of the speed 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 mass and larger torque output, reducing the overall axial size, achieving the advantage of small overall occupied space, being able to design a larger power density, and having enough space to add corresponding sealing structures, so that the hub drive assembly can operate stably and reliably. For the traditional radial motor, as the output torque increases, its axial size also increases. However, in this application, by making the air gap surface 1000 of the motor 100 parallel to the connecting surface 2001, when designing the torque of the motor 100, only its radial size changes, and the axial size of the motor 100 hardly changes. It can be seen that on the premise of small overall axial size occupation of the hub drive assembly, the design space of the motor 100 can be correspondingly increased. At the same time, the braking assembly 300 and the speed reduction assembly 200 are designed with the radial size of the motor 100 as the upper limit to design a speed reduction assembly 200 with better transmission effect and a braking assembly 300 with better braking effect. And the motor 100, the speed reduction assembly 200 and the braking assembly 300 are all flat structures, so that the hub drive assembly formed by assembling the three is flat, can utilize the space inside the hub 700, and is arranged inside the hub 700. The bearings and oil seals are compactly arranged inside the motor and the speed reduction assembly, that is, making full use of the space and further reducing the overall occupied space.

[0104] The above-described embodiments are only used to illustrate the technical ideas and characteristics of the present invention, and the purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. The patent adoption scope of the present invention cannot be limited only by this embodiment, that is, all 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 hub drive assembly, characterized in that, include: an output shaft (600), the output shaft (600) being 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 (200) being provided with two connection surfaces (2001) along two axial sides of the output shaft (600); a brake assembly (300), the brake assembly (300) being fixed to the outer ring of the output shaft (600), the brake assembly (300) being connected to a connection surface (2001) of the reduction assembly (200) facing the wheel hub end surface; a motor (100), the motor (100) being arranged in an annular manner outside the output shaft (600), the motor (100) being connected to a connection surface (2001) of the reduction assembly (200) which faces away from the brake assembly (300), an air gap surface (1000) of the motor (100) being parallel to the connection surface (2001), and the reduction assembly (200), the brake assembly (300) and the motor (100) being located within the periphery of the wheel hub (700); It also includes a wheel hub bearing assembly (500), wherein the wheel hub bearing assembly (500) is fixed between the output shaft (600) and the rotating shaft (140) of the motor (100).

2. The hub drive assembly according to claim 1, characterized in that It also includes a housing (400), wherein the housing (400) includes: 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 surface of the front end cover (411) so as to be connected to the motor (100) on the inner side surface 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 provided on the outer ring of the output shaft (600), the brake disc (310) is abutted and fixed between the wheel hub end face 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, wherein, 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) that is connected to the outer circumference of the front end cover (411) and the outer circumference of the rear end cover (421); The front shell (410) further includes a front motor housing (412). The inner circumference of the front end cover (411) extends and is connected to the front motor housing (412). The motor (100) is disposed between the front end cover (411) and the rear end 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).

5. The wheel hub drive assembly according to claim 4, wherein The motor (100) includes: A front stator (110) that is fixed to the inner side surface of the front end cover (411); A rear stator (120) that is fixed to the inner side surface of the rear end cover (421); A rotor (130) that is held in an air gap between the front stator (110) and the rear stator (120). An air gap surface (1000) is formed between the rotor (130) and the front stator (110) and the rear stator (120) respectively; A rotating shaft (140) that is respectively sealed and rotatably connected to the inner circumference of the front motor housing (412) and the inner circumference of the rear motor housing (422). The radially 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 hub drive assembly according to claim 5, characterized in that, The hub bearing assembly (500) includes: An inner bearing ring (510) that is fixedly connected to the outer circumference of the output shaft (600); An outer bearing ring (520) that is fixed between the inner bearing ring (510) and the rotating shaft (140).

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

8. The wheel hub drive assembly according to claim 6, wherein, It further includes: A first bearing (810) that is connected between the rear motor housing (422) and the rotating shaft (140); A second bearing (830) that is connected between the front motor housing (412) and the rotating shaft (140); A third bearing (850) that is connected between the sealing shell (440) and the output shaft (600).

9. The wheel hub drive assembly according to claim 2, wherein, The deceleration component (200) is a planetary gear deceleration component. Axial two sides of the planet carrier of the deceleration component (200) are limited by a fourth bearing (870) and the sealing shell (440). The fourth bearing (870) is connected between the front end cover (411) and the planet carrier. A stop (441) is arranged on the sealing shell (440) for abutting against the ring gear (220) of the deceleration component (200).

10. The wheel hub drive assembly according to claim 8, characterized in that, It further includes: A first oil seal (820) arranged between the rear motor housing (422) and the rotating shaft (140) and located outside the first bearing (810); A second oil seal (840) arranged between the front motor housing (412) and the rotating shaft (140) and located outside the second bearing (830); A third oil seal (860) arranged between the sealing shell (440) and the output shaft (600) and located outside the third bearing (850); A fourth oil seal (880) located between the hub bearing assembly (500) and the sealing shell (440) and arranged between the output shaft (600) and the rotating shaft (140).

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