CA3150635A1

CA3150635A1 - Wheel drive system

Info

Publication number: CA3150635A1
Application number: CA3150635A
Authority: CA
Inventors: Zaili ZHANG; Zhenzhong DUAN; Xing Wang; Sha Xu; Weikang WANG
Original assignee: CRRC Qishuyan Institute Co Ltd
Current assignee: CRRC Qishuyan Institute Co Ltd
Priority date: 2019-09-09
Filing date: 2020-07-17
Publication date: 2021-03-18
Also published as: AU2020347229A1; WO2021047290A1; AU2024202135A1; AU2020347229B2

Abstract

A wheel drive system, comprising a wheel-side reducer. The wheel-side reducer comprises a frame (4), a torsion tube (6) connected to a wheel and a sealing structure provided between the frame (4) and the torsion tube (6); the sealing structure comprises a static ring (15) fixed to the frame (4) and a moving ring (16) that is disposed opposite to the static ring (15) and is fixed to the torsion tube (6); an end surface of the static ring (15) is provided with multiple rings (15-1) in the radial direction from outside to inside, and an inner circle of the innermost ring is tightly fitted with a throttle ring (21) and a framework oil seal (22); and the moving ring (16) comprises a lower inner ring (16-7), an outer circle of the lower inner ring (16-7) is in contact with the framework oil seal (22) to form a framework oil seal (C) and form a throttle ring seal (D) at a position opposite to the throttle ring (21).

Description

WHEEL DRIVE SYSTEM
TECHNICAL FIELD
100011 The present invention relates to a wheel drive system, in particular to a wheel drive system for an off-highway dump truck.
Background

[0002] The wheel drive system of an off-highway dump truck is installed inside and on the side of a vehicle tire, and drives the vehicle to move forward via speed reduction and torque increase. On electric wheel trucks, in general, the typical process is that, the power of an engine is transmitted to a generator and then transmitted to a traction motor through frequency conversion control. The traction motor converts the electric energy into mechanical energy with a high speed and a small torque, the mechanical energy is then output with a low speed and a large torque through a gear transmission device.

[0003] As a certain amount of lubrication oil is injected into the wheel-side reducers of the above wheel drive system and used for lubricating parts such as internal gears and bearings, reliable sealing is achieved by isolation from the outside by means of static sealing devices of the power input end and dynamic sealing devices of the power output end. The power output end directly contacts the atmosphere above the wheel, with more dust, water vapor and high linear speed, large vibration, as well as the uneven internal pressure, it has a very bad sealing condition and the sealing failure often occurs. Once the sealing fails, the wheel-side reducer is easily damaged, so that the whole vehicle is forced to stop to be maintained, thereby causing large economic loss.

[0004] Chinese patent No. 201210119760.5 discloses a sealing member used together with a torque tube, however, practice shows that after long-term operation of the sealing realized by the technical solution, oil leakage easily occurs due to the fact that: the first part and the second part of the sealing member are mainly used for preventing external pollutants from entering into a gearbox, a sealing ring installed within the third part prevents lubrication oil inside the gearbox from leaking with a lip sealing device by contact sealing. However, when the gearbox works, components such as bearings and gears in the gearbox rotate at a high speed, relative negative pressure is inevitably generated in the area close to the rotating components according to the fluid Bernoulli effect, so that the internal pressure of the gearbox is uneven and unstable. The lip sealing device for realizing the contact sealing is directly subjected to the effect of continuously changing differential pressure inside and outside a gearbox, not only the sealing is not reliable due to the change in shape, but oil leakage is also easily caused by repeated deformation and fatigue failure.

[0005] On the other hand, while the wheel drive system provides power for the vehicle, the wheel-side drive device bears the weight load of the whole vehicle. The structure of an existing wheel-side drive device is shown in Fig.1, the inner end of a motor 2 is in transmission connection with a torque tube 6 supported on a frame 4 through gear transmission device 3, the torque tube 6 is connected with the inner end of a hub 9 installed outside a motor shell through inner and outer bearings 7 and 10, the outer end of the motor 2 is connected with the outer end of the hub 9 via a brake assembly 1 to form an outer sealing structure; the outer end of an inner rim 5 and the inner end of an outer rim 12 which are provided with wedge convergents are sleeved at two ends of the outer circle of a hub 9 respectively, the inner end of the outer circle of the hub 9 has a wedge spigot matched with the wedge convergent of the outer end of the inner rim 5, and a wedge-shaped pressing ring 11 matched with the wedge convergent of the inner end of the outer rim 12 is installed at the outer end of the outer circle of the hub 9. The outer end of the wedge-shaped pressing ring 11 is installed with a spacer ring 8 which presses the wedge-shaped pressing ring 11 on an end face of the hub 9. They are fixed to each other with the help of the wedge-shaped structures at two ends of the outer circle of the hub 9 and those of the inner rim and the outer rim and the spacer ring 8 clamped between the inner rim and the outer rim, they are fixed to each other.
The advantages of the prior art lie in that, the hub and the wheel rims on the two sides are fastened at a time through the spacer rings and the pressing rings with fasteners on one side, and are wedged tightly via the wedge bevels, and therefore the fixed structure is simple and compact, and has a high radial bearing capacity. However, the practice proves that with the continuous increase of the tonnage of the dump truck, the structure in which a plurality of bonding faces transmitting torque through friction force is prone to slip after working for a period of time, thereby causing fault. According to analysis, the root cause of the slipping in the prior art is that, the clamping connection between the hub 9 and the inner rim 5, the clamping connection between the hub 9 and the outer rim 12 completely depend on the fasteners of the wedge-shaped pressing rings 11. Therefore, the manufacturing precision of the inclination angles of the corresponding parts of the wedge spigot of the hub 9, the wedge-shaped pressing ring 11, the inner rim 5 and the outer rim 12 as well as the manufacturing precision of the axial length S of the wedge-shaped pressing ring 11 directly influence the clamping force, and the complex dimension chain relation formed there between is very strict to the distribution of manufacturing tolerance. In practice, the theoretically required manufacturing precision is difficult to be obtained.

[0006] It was found that Chinese Patent No. 201280012998.6 discloses a wheel assembly used on off-highway vehicles. According to the technical solution, the hubs are connected with the wheel rims on the two sides through the bolts respectively, so that the defect that the hubs are easy to slip due to the fact that torque is transmitted mainly by means of friction force of a bonding face is overcome. However, a hub adapter is additionally required, which leads to a complex structure.
Also, the transmission is essentially transmitted by the clamping friction force, so that the reliability is still not enough.

[0007] On one hand, most of the hubs of a mining dump truck in current market are integrally cast, large numbers of procedures and complex influence factors of castings, lead to the defects of a unstable quality. Also, air holes and looseness easily occur.

[0008] On the other hand, the wheel-side gearbox is usually a two-stage or three-stage transmission mechanism, wherein a high-speed small-torque load is input by the first stage and is changed into a low-speed large-torque load step by step. When an existing wheel drive system works, a certain amount of lubrication oil is filled in a wheel-side gearbox, and components such as gears, bearings and friction pairs are lubricated in a splashing way through oil stirring of rotary-type components and parts. However, due to the fact that the positions of individual components and parts in the wheel-side gearbox are improper, lubrication oil cannot lubricate the components and parts in splashing way, thereby the service life of the components and parts is affected, and then the reliability of the wheel-side gearbox is affected.
SUMMARY

[0009] The main object of the present invention is to provide a wheel drive system to address the problems in the prior art.
100101 To achieve the above object, according to one aspect of the present invention, there is provided a wheel drive system, which comprises a wheel-side reducer with a frame and a torque tube connected to a wheel and a sealing structure provided between the frame and the torque tube, wherein the sealing structure comprises a static ring fixed to the frame and a moving ring disposed opposite to the static ring and fixed to the torque tube, characterized in that, a plurality of annular rings are provided on an end face of the static ring in the radial direction from outside to inside, wherein an inner circle of the innermost annular ring is tightly fitted with a throttle ring and an oil seal; and the moving ring comprises a lower edge inner ring, wherein an outer circle of the lower edge inner ring forms an oil sealing by contacting the oil seal, and forms a throttle ring sealing at a position opposite to the throttle ring.
[0011] Further, the throttle ring includes a set of radially extending comb teeth which are axially spaced.
[0012] Further, a thickness of the comb tooth is substantially the same as a width of a gap between the comb teeth, and a length of the comb tooth is 2-2.5 times the thickness of the comb teeth.
[0013] Further, one end of the throttle ring adjacent to the oil seal is provided with a limiting protrusion.
[0014] Further, at least three annular rings are provided on the end face of the static ring in the radial direction from outside to inside, and the outer circle of the innermost annular ring is provided with a clamping groove for embedding a seal; and ring protrusions provided on the end face of the moving ring in the radial direction from outside to inside are embedded between the adjacent annular rings to form radial labyrinth sealing, and an inner circumferential surface of the ring protrusions opposite to the clamping groove forms an oil sealing by contacting the seal.
[0015] Further, the static ring is fixed to a frame of the wheel-side reducer by a buckling edge thereof, wherein an inner spigot of the buckling edge is in transition fit with an outer spigot on the frame.
[0016] Further, the wheel drive system further comprises a hub, wherein two ends of the hub are fixedly sleeved with an outer end of an inner rim and an inner end of an outer rim, respectively.
[0017] Further, the outer end of the inner rim has a wedge convergent and the inner end of the hub has a wedge spigot matching with the wedge convergent, wherein the wedge spigot and a pressing ring or a clamping ring which is pressed on the outer end face of the inner rim form a clamping structure to the wedge convergent through a penetrating bolt.
[0018] Further, an inner fitting face with a through hole extends from the vicinity of the outer end of the inner rim towards the rotation axis, the inner end of the hub has a flange turnup, and the outer end face of the flange turnup fits the inner end face of the inner fitting face to form a fastening structure by a penetrating fastener.
[0019] Further, an inner retaining ring or an inner retaining hoop with a through hole abutting against the outer end face of the hub with the threaded hole extends from the vicinity of the inner end of the outer rim towards the rotation axis, wherein the fastener is screwed into the threaded hole of the hub via the through hole of the inner retaining ring or the inner retaining hoop to form a pressing and fastening structure.
10020] Further, the inner end of the outer rim has a wedge convergent and the outer end of the hub is fitted with a bevel edge wedge ring, the bevel edge wedge ring has a wedge bevel matching with the wedge convergent of the inner end of the outer rim; wherein the outer end of the bevel edge wedge ring presses the outer end of the hub has with a reduced diameter, and a wedge plug extends from the bevel edge inner end of the bevel edge wedge ring is inserted into a radial spacing between the hub and an outer rim; and wherein the wedge bevel and the right clamping ring form a clamping structure for the wedge convergent.
[0021] Further, the outer end of the inner rim is provided with a wedge convergent and the inner end of the hub is provided with a wedge spigot matching with the wedge convergent formed on one side of the radial epotaxial edge, the wedge spigot and a left clamping ring which is pressed on the outer end face of the inner rim form a clamping structure to the wedge convergent through a penetrating bolt; wherein a step-shaped locking bolt which penetrates through the right clamping ring and the left clamping ring and then is screwed into the radial epotaxial edge is fitted in a through hole of the bevel edge wedge ring, a small-diameter section and a large-diameter section of the locking bolt are provided with reverse threads for screwing a left nut and a right nut respectively, and a lock nut is arranged at the outer end of the locking bolt;
the non-circular profiles of the left nut and the right nut are respectively matched with counter bores at corresponding positions of the left clamping ring and the right clamping ring to form a kinematic pair.
[0022] Further, the wheel drive system further comprises a hub, wherein the hub includes a body having an inner ring, a radial outer edge, and a radial epotaxial edge, the radial outer edge and the radial epotaxial edge are located respectively on two axial side of the inner ring, and the radial outer edge and the radial epotaxial edge both protrude from the inner ring in the radial direction, wherein the wheel drive system further comprises an outer ring which is located on the radial outer side of the inner ring in a radially spaced way, and which is fixed to the radial outer edge and the radial epotaxial edge.
[0023] Further, the body is integrally formed and the outer ring is connected to the body through material bonding.
[0024] Further, the outer ring is fixed to the radial outer edge and the radial epotaxial edge by welding.

[0025] Further, the body is integrally forged into one piece.
[0026] Further, an annular cavity is provided between the inner ring and the outer ring.
[0027] Further, the outer ring comprises a first outer ring portion and a second outer ring portion, wherein the first outer ring portion and the second outer ring portion are located at different positions circumferentially of the hub.
[0028] Further, the first outer ring portion and the second outer ring portion are columnar reinforcing structures, wherein the dimensions of the first outer ring portion and the second outer ring portion along the axial direction of the hub are greater than the dimensions of the first outer ring portion and the second outer ring portion along the radial and/or circumferential direction of the hub.
[0029] Further, the first outer ring portion and the second outer ring portion are configured as a curved plate.
[0030] Further, the first outer ring portion and the second outer ring portion are interconnected by welding.
[0031] Further, the outer ring covers only a portion of the circumference of the hub.
[0032] Further, the outer ring has through holes thereon.
[0033] Further, the wheel drive system further comprises a hub, wherein two ends of the hub are configured as a radial epotaxial edge and a radial outer edge respectively, and outer ring through holes and inner ring threaded holes are evenly distributed on the periphery of the end face of the radial epotaxial edge at intervals; and wherein at least one circle of threaded holes are evenly distributed at the periphery of the end face of the radial outer edge at intervals.
[0034] Further, the wheel drive system further comprises a gearbox lubrication device which comprises a horizontal shaft sun gear with two ends axially limited and supported by a first axial thrust ring and a second axial thrust ring respectively, wherein the first axial thrust ring is embedded in a counter bore at the inner end of an end cover of the box, the end cover of the box is fixed on a planetary carrier serving as a shell in a sealing and covering manner, the sun gear is externally meshed with the planetary gear, the planetary gear is internally meshed with the fixed gear ring, the planetary gear is supported on a planetary pin shaft through a planetary gear bearing;
and wherein an oil collecting box which is located above the first axial thrust ring and communicated with the bottom oil outlet is fixed to the end cover of the box, and the oil collecting box is provided with an oil inlet which is close to and directly faces the meshing position between the sun gear and the planetary gear; the outer circle of the first axial thrust ring is provided with a circumferential oil channel corresponding to the oil outlet in position and an end face oil groove extending in the radial direction, the circumferential oil channel is at least communicated with an inner hole of the circumferential oil channel through a radial oil hole or communicated with the end face oil groove through an axial oil channel.
[0035] Another object of the present invention lies in that: providing a combined sealing structure of the wheel-side reducer, which is capable of effectively avoiding oil leakage and remarkably improving the sealing reliability by improving the structure directed to the defects in the prior art.
[0036] On such cognitive basis, the applicant provides a combined sealing structure of wheel-side reducer capable of avoiding sealing failure caused by pressure fluctuation, and the basic technical solution comprises: a static ring fixed to the frame and a moving ring disposed opposite to the static ring and fixed to the torque tube, wherein at least three annular rings are provided on the end face of the static ring in the radial direction from outside to inside;
wherein a clamping groove for embedding packing is formed in the outer circle of the innermost annular ring, an inner circle of the innermost annular ring is tightly fitted with a throttle ring and an oil seal, the throttle ring has a set of radially extending comb teeth which are axially spaced; wherein the end face of the moving ring is provided with an ring protrusion embedded between the adjacent annular rings to form radial labyrinth sealing in the radial direction from outside to inside and a lower edge inner ring;
the inner circumferential surface of the ring protrusion opposite to the clamping groove contacts the packing to form packing seal; and wherein the outer circle of the lower edge inner ring forms an oil sealing by contacting the oil seal and forms a throttle ring sealing at a position opposite to the throttle ring.
[0037] The quadruple sealing structures have respective functions: the labyrinth sealing mainly plays a role in dust prevention and can prevent the entry of most external particles; the contact-type packing seal not only completely prevents the entry of particles, but also blocks the external water vapor; the main sealing effect of the oil seal is to tightly block lubrication oil in the wheel-side reducer; the throttle ring sealing has the effect of generating a friction effect when fluid passes through the zigzag throttling gap of the comb tooth and reducing the pressure on the oil seal;
moreover, a set of expansion cavities are formed among the comb teeth of the throttle ring at the same time, even if the internal pressure is uneven and unstable due to negative pressure in the gearbox, the lip edge of the oil seal is not affected any more via buffering and restraining of the expansion cavities. Besides, outside airflow is completely blocked through packing seal on the outer side of the oil seal, so that the lip edge of the oil seal is always in a stable and reliable sealing state, fatigue failure is effectively avoided, and oil leakage is not prone to occur after long-term use.
[0038] The present invention is further improved as follows: a wear band is embedded in the position, corresponding to the oil seal, of the lower edge inner ring of the moving ring. In this way, during operation, the lip of the oil seal contacts the wear band and rotates relatively in the circumferential direction, abrasion of the moving ring with high manufacturing cost is avoided, only the abraded wear band needs to be replaced after running for a period of time (20000-25000 hours), and the running cost is remarkably saved.
[0039] The present invention is further improved as follows: the static ring is fixed to a frame of the wheel-side reducer through a buckling edge thereof, an inner spigot of the buckling edge is in transition fit with an outer spigot on the frame, and a sealant is coated between the inner spigot and the outer spigot. Therefore, not only the disassembly and assembly during maintenance are facilitated, but the lubrication oil can also be preferentially prevented from leaking from the fit clearance between the static ring and the frame.
[0040] The present invention is further improved as follows: a thickness of the comb teeth is substantially the same as a width of a gap between the comb teeth, a length of the comb tooth is 2-2.5 times the thickness of the comb tooth. Tests prove that the optimized parameters ensure that fluid causing continuously-changed internal pressure of the wheel-side reducer fully releases kinetic energy in the throttle cavity, and therefore, the impact of internal pressure change of the wheel-side reducer on a lip of the oil seal is effectively restrained.
[0041] The present invention is further improved as follows: one end of the moving ring which is far away from the static ring is provided with a moving ring installing face on the inner circumference and a connecting plate installing base on the end face, the radial position of the moving ring is limited by the radial transition fit between the moving ring installing face and the torque tube, the axial position of the moving ring is limited by the connecting plate mounted and clamped in the corresponding clamping groove of the torque tube by the connecting plate installing base. As a result, the moving ring and the torque tube are flexibly connected, and the influence of twisting deformation of the torque tube on the moving ring is isolated.
[0042] The present invention is further improved as follows: one end of the throttle ring adjacent to the oil seal is provided with a limiting protrusion, so that the oil seal can be stably and axially limited, and the sealing effect of the oil seal can be better obtained.
[0043] The present invention further aims to provide the wheel-side drive device which can effectively avoid the slipping phenomenon and is simple in structure, in order to overcome the defects in the prior art.
[0044] In order to achieve the above objects, the basic technical solution of the wheel-side drive device comprises: a motor mounted on an outer side of a frame for determining an rotation axis, an inner output end of the motor being in transmission connection with a torque tube supported on the frame through a gearbox; wherein the torque tube is fixed to the inner end of a hub sleeved outside the motor, and the outer end of the motor is connected with the frame via a brake assembly and is connected with the outer end of the hub to form an outer sealing device; wherein two ends of the hub are fixedly sleeved with the outer end of the inner rim and the inner end of the outer rim respectively.
[0045] One technical solution for the wheel-side drive device is: the outer end of the inner rim has a wedge convergent and the inner end of the hub has a wedge spigot matching with the wedge convergent, and wherein the wedge spigot and a pressing ring which is pressed on the outer end face of the inner rim form a clamping structure to the wedge convergent through a penetrating bolt;
an inner retaining ring with a through hole abutting against the outer end face of the hub with the threaded hole extends from the vicinity of the inner end of the outer rim towards the rotation axis, and wherein the fastener is screwed into the threaded hole of the hub via the through hole of the inner retaining ring to form a pressing and fastening structure.
[0046] Further, the hub is provided with an inner end radial epotaxial edge with a wedge spigot on one side, and the opposite end faces of the inner end radial epotaxial edge and the pressing ring are respectively provided with an edge ring concave and a protruding ring which are matched with each other.
[0047] Further, the inner retaining ring is abutted against the outer end face of the radial outer edge of the outer end of the hub, wherein the outer end face is provided with the threaded hole.
[0048] Further, two ends of a hub cylinder of the hub respectively have a radial outer edge and a radial epotaxial edge; a reducing connecting circle extends from one side, far away from the wedge spigot, of the radial epotaxial edge in the axial direction; a reducing connecting ring extends from the radial outer edge in the axial direction; through holes used for forming a clamping structure to the wedge convergent are evenly distributed on the periphery of the end face of the radial epotaxial edge at intervals, threaded holes used for fixing a torque tube are evenly distributed on the periphery of the end face of the connecting ring at intervals; threaded holes used for fixing the inner retaining ring are evenly distributed on the periphery of the end face of the radial outer edge at intervals, and threaded holes used for fixing the outer sealing device are evenly distributed on the periphery of the end face of the connecting ring.
[0049] Further, reinforcing ribs for connecting the radial epotaxial edge and the radial outer edge are evenly distributed on the surface of the outer circle of the hub cylinder in the circumferential direction at intervals.
[0050] Further, reinforcing arcs for connecting the radial epotaxial edge and the radial outer edge are evenly distributed outside the outer circle of the hub cylinder at intervals in the circumferential direction.
[0051] A second technical solution of the wheel-side drive device comprises:
an inner fitting face with a through hole extends from the vicinity of the outer end of the inner rim towards the rotation axis, the inner end of the hub has a flange turnup, and the outer end face of the flange turnup attaches to the inner end face of the inner fitting face to form a fastening structure by a penetrating fastener; an inner retaining hoop with a through hole abutting against the outer end face of the hub with the threaded hole extends from the vicinity of the inner end of the outer rim towards the rotation axis, and the fastener is screwed into the threaded hole of the outer end face of the hub via the through hole of the inner retaining hoop to form a pressing and fastening structure.
[0052] Further, two ends of a hub cylinder of the hub respectively have a radial outer edge and a radial epotaxial edge; the end face of the radial epotaxial edge is provided with through holes which are evenly distributed on the outer periphery at intervals and used for attaching the inner fitting face through penetrating bolts to form a fixed structure, and threaded holes which are evenly distributed on the inner periphery at intervals and used for fixing the torque tube are formed; the outer end face of the radial outer edge is provided with threaded holes which are evenly distributed on the periphery at intervals and used for fastening the inner retaining hoop and the outer sealing device at the same time.
[0053] Further, reinforcing ribs for connecting the radial epotaxial edge and the radial outer edge are evenly distributed on the surface of the outer circle of the hub cylinder in the circumferential direction at intervals.

[0054] Further, reinforcing arcs for connecting the radial epotaxial edge and the radial outer edge are evenly distributed outside the outer circle of the hub cylinder in the circumferential direction at intervals.
[0055] A third technical solution of the wheel-side drive device comprises:
the outer end of the inner rim has a wedge convergent and the inner end of the hub has a wedge spigot matching with the wedge convergent formed on one side of the radial epotaxial edge; the inner end of the outer rim has a wedge convergent and the outer end of the hub is fitted with a bevel edge wedge ring which has a wedge bevel matching with the wedge convergent of the inner end of the outer rim;
wherein the outer end of the bevel edge wedge ring presses the outer end of the hub has with a reduced diameter, and a wedge plug extends from the bevel edge inner end of the bevel edge wedge ring is inserted into a radial spacing between the hub and an outer rim; the wedge spigot at the inner end of the hub and the wedge bevel of the outer bevel edge wedge ring of the hub form a clamping structure to wedge convergents at two sides with the left clamping ring and the right clamping ring which are pressed on the outer end face of the inner rim respectively.
[0056] Further, a step-shaped locking bolt which penetrates through the right clamping ring and the left clamping ring and then is screwed into the radial epotaxial edge is fitted in a through hole of the bevel edge wedge ring, a small-diameter section and a large-diameter section of the locking bolt are provided with reverse threads for screwing a left nut and a right nut respectively, and a lock nut is arranged at the outer end of the locking bolt; the non-circular profiles of the left nut and the right nut are respectively matched with counter bores at corresponding positions of the left clamping ring and the right clamping ring to form a kinematic pair.
[0057] Compared with the prior art, the above technical solution has the advantages that: the hub is respectively and independently fixed to the inner rim and the outer rim, so that the slipping risk of torque transmission of a middle friction surface is remarkably reduced, the stress of each bolt during clamping connection is only half of the original stress, and thus providing a better stress condition. In addition, compared with the technical solution disclosed by the Chinese patent 201280012998.6, a hub adapter is omitted, so that providing a simpler structure.
[0058] Another object of the present invention is to provide a wheel-side drive hub, the basic technical solution comprises: a hub cylinder, wherein two ends of the hub cylinder are configured as a radial epotaxial edge and a radial outer edge respectively; wherein the outer ring through holes and the inner ring threaded holes are evenly distributed on the periphery of the end face of the radial epotaxial edge at intervals; and wherein at least one circle of threaded holes are evenly distributed at the periphery of the end face of the radial outer edge at intervals.
[0059] Thus, on one hand, the radial epotaxial edge of the hub cylinder can be fixed to the inner retaining structure of the inner rim by means of a fastener passing through the through hole of the outer ring, and is fixed to the torque tube by means of a bolt passing through the threaded hole of the inner ring; on the other hand, the radial outer edge can be fixed to the outer rim and the brake assembly by means of bolt fasteners passing through the threaded holes.
Compared with the prior art, the hub is respectively and independently fixed to the inner rim and the outer rim, so that the slipping risk of torque transmission of a middle friction surface is obviously reduced, the stress of each bolt during clamping connection is only half of the original stress, and thus providing a better stress condition.
[0060] One technical solution for the drive hub comprises: a wedge spigot matched with the wedge convergent of the inner rim is formed on one side of the radial epotaxial edge, and a reducing connecting ring axially extends from the other side of the radial epotaxial edge; through holes used for forming a clamping structure of a wedge convergent with the pressing ring through penetrating bolts are evenly distributed on the periphery of the end face of the radial epotaxial edge at intervals, and threaded holes used for fixing a torque tube are evenly distributed on the periphery of the end face of the connecting ring at intervals.
[0061] Still further: a reducing connecting ring extends from the radial outer edge in the axial direction; threaded holes used for fixing an inner retaining ring of an outer rim are evenly distributed on the periphery of the end face of the radial outer edge at intervals, and threaded holes used for fixing an outer sealing device are evenly distributed on the periphery of the end face of the connecting ring.
[0062] A second technical solution for the drive hub comprises: the end face of the radial epotaxial edge is provided with through holes which are evenly distributed on the outer periphery at intervals and used for attaching the inner fitting face of the inner rim through penetrating bolts to form a fixed structure, and threaded holes which are evenly distributed on the inner periphery at intervals and used for fixing the torque tube are provided.
[0063] Further, the outer end face of the radial outer edge is provided with threaded holes which are evenly distributed on the periphery at intervals and used for fastening the inner retaining hoop of the outer rim and the outer sealing device at the same time.
[0064] In the above two technical solutions of the drive hub, further, reinforcing ribs for connecting the radial epotaxial edge and the radial outer edge are evenly distributed on the surface of the outer circle of the hub cylinder in the circumferential direction at intervals, or reinforcing arcs for connecting the radial epotaxial edge and the radial outer edge are evenly distributed outside the outer circle of the hub cylinder in the circumferential direction at intervals.
[0065] Another object of the present invention is to provide a hub comprising a body, wherein the body comprises an inner ring, a radial outer edge and a radial epotaxial edge, the radial outer edge and the radial epotaxial edge are located respectively on two axial side of the inner ring, and the radial outer edge and the radial epotaxial edge both protrude from the inner ring in the radial direction, wherein the wheel drive system further comprises an outer ring which is located on the radial outer side of the inner ring in a radially spaced way, and which is fixed to the radial outer edge and the radial epotaxial edge.
[0066] Further, the body is integrally formed and the outer ring is connected to the body through material bonding.
[0067] Further, the outer ring is fixed to the radial outer edge and the radial epotaxial edge by welding.
[0068] Further, the body is integrally forged into one piece.
100391 Further, an annular cavity is provided between the inner ring and the outer ring.
[0070] Further, the outer ring comprises a first outer ring portion and a second outer ring portion, wherein the first outer ring portion and the second outer ring portion are located at different positions circumferentially of the hub.
[0071] Further, the first outer ring portion and the second outer ring portion are columnar structures, wherein the dimensions of the first outer ring portion and the second outer ring portion along the axial direction of the hub are greater than the dimensions of the first outer ring portion and the second outer ring portion along the radial and/or circumferential direction of the hub.
100721 Further, the first outer ring portion and the second outer ring portion are configured as a curved plate.
[0073] Further, the first outer ring portion and the second outer ring portion are interconnected by welding.
[0074] Further, the outer ring covers only a portion of the circumference of the hub.
[0075] Further, the outer ring has through holes thereon.
[0076] At present, the hub structure is applied to a wheel-side reducer of a 300-tonnage mining dump truck, compared with an integrally cast hub, defects of the components are greatly reduced and mechanical performance is correspondingly improved. Particularly, the following beneficial effects are achieved:
1. Compared with an integrally cast structure, the defects of cast looseness and the like generated in the smelting process of metal can be eliminated with forging, so that the microstructure structure is optimized. As a complete metal flow line is preserved with forging, the mechanical performance of the forge piece is generally better than that of a cast piece made of the same material, and thus the forge piece is suitable for environments with more severe working conditions.
[0077] 2. Compared with an integrally cast structure, the manufacturing cost of forging is reduced to a great extent relative to that of casting parts with the same structure.
For mass production of components, the cost can be reduced to a certain extent, and the cost performance is improved to a certain extent.
[0078] Another object of the present invention is to provide a lubrication device of wheel-side gearbox capable of properly solving the problem of lubricating components at improper positions which are difficult to be splashed, which is directed to the problems in the prior art.
[0079] In order to achieve the above object, the basic technical solution of the lubrication device of the wheel-side gearbox comprises: a horizontal shaft low-speed stage sun gear with two ends axially limited and supported by a first axial thrust ring and a second axial thrust ring respectively, wherein the first axial thrust ring is embedded in a counter bore in the inner end of an end cover of the box, the end cover of the box is fixed on a low-speed stage planetary carrier serving as a shell in a sealing and covering manner, the low-speed stage sun gear is externally meshed with a low-speed stage planetary gear, the low-speed stage planetary gear is internally meshed with a fixed gear ring, and the low-speed stage planetary gear is supported on a low-speed stage planetary pin shaft through a low-speed stage planetary gear bearing; and wherein an oil collecting box which is located above the first axial thrust ring and communicated with the bottom oil outlet is fixed to the end cover of the box; and the oil collecting box is provided with an oil inlet which is close to and directly faces the meshing position of the low-speed stage sun gear and the low-speed stage planetary gear; the outer circle of the first axial thrust ring is provided with a circumferential oil channel corresponding to the oil outlet in position and an end face oil groove extending in the radial direction, and the circumferential oil channel is at least communicated with an inner hole of the circumferential oil channel through a radial oil hole or communicated with the end face oil groove through an axial oil channel.
[0080] The present invention is further improved as follows: the oil collecting box is arc-shaped and is located between the outer ring of the counter bore embedded with the first axial thrust ring and the inner circle of the flange ring of the end cover of the box.
[0081] The present invention is still further improved as follows: the oil collecting box is formed by a thin-wall metal plate welded on an end cover of the box.
[0082] The present invention is yet further improved as follows: the end face oil grooves are evenly distributed in the circumferential direction, extend in the radial direction and deepen from outside to inside.
[0083] The present invention is also further improved as follows: one end of the horizontal shaft low-speed stage sun gear is axially limited and supported by a first axial thrust ring with a central shaft thereof, the other end of the horizontal shaft low-speed stage sun gear is axially limited and supported by a second axial thrust ring with an end face counter bore, and the second axial thrust ring is sleeved on the reducing shaft end of the front stage sun gear.
[0084] Thus, during operation, oil extruded from a gap between meshing teeth of the low-speed stage sun gear and the low-speed stage planetary gear enters into the oil collecting box through the oil inlet, and then leaks to the circumferential oil channel of the first axial thrust ring from the oil outlet in the bottom, and the oil in circumferential oil channel flows through a radial oil hole or an end face oil groove and lubricates the surfaces of rotation pair formed by the inner hole of the first axial thrust ring and the low-speed stage sun gear as well as the friction surface which is axially limited, so that the problem of lubrication of components at improper positions which are difficult to be splashed in a low-speed edge area is solved properly.
[0085] In the present application, the technical terms such as wheel-side reducer, wheel-side gearbox and wheel-side drive device all refer to similar drive/reduction parts.
BRIEF DESCRIPTION OF THE DRAWINGS
[0086] The accompanying drawings, which form a part of the present invention, serve to provide a further understanding of the present invention, and illustrative embodiments of the invention and descriptions thereof serve to explain the present invention, and do not constitute an undue limitation of the invention. In the accompanying drawings:
FIG. 1 is a structural schematic view of an existing wheel-side drive device.
[0087] FIG. 2 is a schematic view of a combined sealing structure of the wheel drive system of the present invention; and FIG. 3 is an enlarged partial view at M in FIG. 2; and FIG. 4 is an enlarged partial view at N in FIG. 3; and FIG. 5 is a schematic view illustrating individual seal structure labels of FIG. 4; and FIG. 6 is a first structural schematic view of a wheel-side drive device of the wheel drive system of the present invention; and FIG. 7 is a second structural schematic view of a wheel-side drive device of the wheel drive system of the present invention; and FIG. 8 is a third structural schematic view of a wheel-side drive device of the wheel drive system of the present invention; and FIG. 9-1 is a schematic view of three-dimensional structure of the hub employed in FIG. 6; and FIG. 9-2 is a cross-sectional view of FIG. 9-1; and FIG. 9-3 is a schematic view of three-dimensional structure of FIG. 9-1 from another perspective;
and FIG. 10-1 is a schematic view of three-dimensional structure of another hub employed in FIG. 6;
and FIG. 10-2 is a cross-sectional view of FIG. 10-1; and FIG. 10-3 is a schematic view of three-dimensional structure of FIG. 10-1 from another perspective;
and FIG. 11-1 is a schematic view of three-dimensional structure of the hub employed in FIG. 7; and FIG. 11-2 is a cross-sectional view of FIG. 11-1; and FIG. 11-3 is a schematic view of three-dimensional structure of FIG. 11-1 from another perspective;
and FIG. 12-1 is a schematic view of three-dimensional structure of another hub employed in FIG. 7;
and FIG. 12-2 is a cross-sectional view of FIG. 12-1; and FIG. 12-3 is a schematic view of three-dimensional structure of FIG. 12-1 from another perspective;
and FIG. 13 shows a front view of a hub structure in the wheel drive system of the present invention;
and Fig. 14 shows a left side view of the hub structure in Fig. 13; and FIG. 15 shows a right side view of the hub structure in FIG. 13; and Fig. 16 shows a first cross-sectional view of the hub structure in Fig. 13;
and Fig. 17 shows a second cross-sectional view of the hub structure of Fig. 13;
and FIG. 18 is a structural schematic view of a lubrication device of a gearbox in the wheel drive system of the present invention; and FIG. 19 is a schematic view of three-dimensional structure of the end cover of FIG. 18; and FIG. 20 is a schematic view of cross-sectional structure of the end cover of FIG. 18; and FIG. 21 is a schematic view of three-dimensional structure of the first axial thrust ring of FIG. 18;
and FIG. 22 is a schematic view of cross-sectional structure of the first axial thrust ring of FIG. 18;

and FIG. 23 is a schematic view of three-dimensional structure of another first axial thrust ring in the lubrication device of a gearbox of the present invention; and FIG. 24 is a schematic view of cross-sectional structure of another first axial thrust ring in a lubrication device of a gearbox of the present invention.
And, therein, the above-mentioned accompanying drawings include the following reference numerals:
a brake assembly 1, a motor 2, a gearbox 3, a frame 4, an inner rim 5, a wedge convergent 5-1, a protruding ring 5-2, an inner fitting face 5-2', a torque tube 6, a connecting plate fixing groove 6-1, an inner bearing 7, pressing rings 8 and 8', a left clamping ring 8z, a right clamping ring 8y, a hub 9, a wedge spigot 9-1, an edge ring concave 9-2, a flange turnup 9-2', a radial epotaxial edge 9-3, a radial outer edge 9-4, a reinforcing rib 9-5, a reinforcing arc 9-5' a hub cylinder 9-6, a connecting ring 9-7, a connecting ring 9-9, an outer bearing 10, bevel edge wedge rings 11 and 11', a wedge plug 11-1, a reducing spigot 11-2, an outer rim 12, an inner retaining ring 12-1, an inner retaining hoop 12-2, a locking bolt 13, a left nut 13z, a right nut 13y, a lock nut 14, a static ring 15, a annular ring 15-1, a clamping groove 15-2, a buckling edge 15-5, an assembling face 15-6, a moving ring 16, a ring protrusion 16-1, a fitting face 16-2, a ring groove 16-4, a wear band installing groove 16-5, a connecting plate installing base 16-6, a lower edge inner ring 16-7, a moving ring installing face 16-8, a static ring installing bolt 17, an lock washer 18, an flat sealant 19, a packing 20, a throttle ring 21, comb teeth 21-1, a limiting protrusion 21-2, an oil seal 22, a moving ring installing bolt 23, a conical washer 24, a connecting plate 25, a wear band 26, an 0-ring 27, a gear meshing 28, a bearing rotating 29 and a body 30, an outer ring 31, a first outer ring portion 31-1, a second outer ring portion 31-2, a first weld 32, a second weld 33, an inner ring 34, an annular cavity 35, a through hole 36, an end cover 37, an oil collecting box 37-1, an oil inlet 37-2, an oil outlet 37-3, a first axial thrust ring 38, a circumferential oil channel 38-1, a radial oil hole 38-2, an axial oil channel 38-2', an end face oil groove 38-3, a low-speed stage sun gear 39, a low-speed stage planetary carrier 40, a low-speed stage planetary gear 41, a low-speed stage planetary pin shaft 42, a low-speed stage planetary gear bearing 43, a gear ring 44, a front stage 45, a second axial thrust ring 46.
DETAILED DESCRIPTION
[0088] It is noted that, embodiments of the present invention and features in embodiments may be combined with each other without conflict. The present invention will be described in detail with reference to the accompanying drawings and in connection with embodiments.
[0089] The present invention is described in further detail below in connection with specific examples, which are not to be construed as limiting the scope of the invention as claimed.
[0090] The combined sealing structure of the wheel-side reducer in wheel drive system is applied between the torque output end of a mine wheel-side reducer shown in FIG. 2 and a frame 4 connected with a rear axle of a vehicle and a torque tube 6 connected with tires of the vehicle. A
static ring 15 and a moving ring 16 are fixed to the opposite positions of the frame 4 and the torque tube 6 respectively, specifically as shown in FIG. 3 and FIG. 4, a buckling edge 15-5 of the static ring 15 is assembled and fixed to the frame 4 of the wheel-side reducer with a static ring installing bolt 17 and an lock washer 18, an inner spigot of the buckling edge 15-5 is in transition fit with an outer spigot of the frame 4, the inner spigot of the static ring 15 is in transition fit with the outer spigot of the frame 4, an flat sealant 19 is coated on an assembling face 15-6 of the static ring 15 and the frame 4, including an end face and a spigot fitting face, and the flat sealant 19 is used for preventing lubrication oil from leaking from the assembling face 15-6.
[0091] Three annular rings 15-1 are provided on the end face of the static ring 15 in the radial direction from outside to inside, the outer circle of the innermost annular ring is provided with a clamping groove 15-2 for embedding an oil seal, namely a packing 20, the width of the clamping groove is slightly smaller than that of the packing 20, two end faces of the clamping groove contact the bottom face and press on the packing 20 tightly, and the fastening glue is coated between the packing 20 and the packing installing groove 15-2 and used for fixing the packing in the circumferential direction, so that the circumferential sliding in the working process can be avoided.
A throttle ring 21 and an oil seal 22 are tightly assembled on the inner circle of the innermost annular ring. The throttle ring 21 is provided with a set of four radially-extending comb teeth 21-1 which are spaced axially, wherein the thickness of the comb tooth is basically consistent with the width of gaps among the comb teeth, and the length of the comb tooth is 2-2.5 times of the thickness of the comb teeth; and wherein a limiting protrusion 21-2 is arranged at one end of the throttle ring 21 which is close to the oil seal 22õ thereby preventing the throttle ring 21 from interfering with a spring in the oil seal.
100921 An ring protrusion 16-1 and a lower edge inner ring 16-7 which are embedded between adjacent annular rings to form a radial labyrinth sealing A are provided on the end face of the moving ring 16 in the radial direction from outside to inside. The inner circumferential surface of the ring protrusion opposite to the clamping groove 15-2 contacts the packing to form a packing seal B. A moving ring installing face 16-8 and a connecting plate installing base 16-6 are provided at one end of the moving ring 16 which far away from the static ring 15; the moving ring 16 is in radial transition fit with the torque tube 6 via the moving ring installing face 16-8, so that the radial position of the moving ring 16 is limited. A moving ring 16 is assembled with a connecting plate 25 by a connecting plate installing base 16-6, a circle of evenly distributed connecting plates 25 (8-16 connecting plates) are assembled on the moving ring 16 via moving ring installing bolts 23, and a conical washer 24 is cushioned below the moving ring installing bolt 23 and is used for providing sufficient pre-tightening force. The connecting plate 25 is clamped in a connecting plate fixing groove 6-1 on the torque tube 6, so that the axial position between the moving ring 16 and the torque tube 6 is fixed. A wear band installing groove 16-5 is formed in the lower edge 16-7 of the moving ring, and the outer diameter of the groove is in interference fit with a wear band 26, so that the wear band 26 is embedded in the position of the lower edge inner ring 16-7 which corresponds to the oil seal 22. The connecting plate 25 is clamped in a groove in the torque tube 6 so as to limit the axial position of the moving ring 16; a ring groove 16-4 for mounting an 0-ring 27 is provided on the moving ring installing face 16-8. The outer circle of the lower edge inner ring 16-7 forms an oil sealing C by contacting an oil seal 22, and forms a throttle ring sealing D at the position opposite to the throttle ring.
[0093] In conclusion, the above structures of the embodiments form four sealing solutions, namely a dustproof labyrinth sealing A, a packing seal B, an oil sealing C and a throttle ring sealing D, which are internally associated with one another and shown in FIG. 5. Therein, the dustproof labyrinth sealing A forms at least two labyrinth cavities, the radial gap of each dustproof labyrinth cavity is 1.5-2mm, and the dustproof labyrinth cavities are filled with lubrication grease. Such non-contact type seal is used for blocking external large-size particles from entering into the reducer and blocking and reducing part of small-particle dust and water vapor from entering into a contact sealing surface at the internal packing. A fitting face 16-2 of the packing seal B contacts with a certain pressure, and relatively slides during operation. The lubrication grease in the gap provides sufficient lubrication for the fitting face 16-2 of the packing, and the lubrication grease is mainly used for blocking external water vapor and dust from entering into the gearbox. The surface hardness of the wear band 26 of the oil sealing C is not smaller than HRC 60.
When the wheel-side reducer operates, the oil seal 22 and the wear band 26 slide relatively, and the sealing lip is made of rubber materials and has good elasticity, so that the influence of the change of the jumping value between the moving and static parts caused by part deformation due to vehicle weight change and impact load during the operating of the reducer on sealing can be resisted. In the throttle ring sealing D, a 0.5-0.8mm gap is formed between the lower end of the comb teeth of the throttle ring and the fitting face of the moving ring. When the wheel-side reducer operates, due to gear meshing 28 and bearing rotation 29 near the moving and static seals of the output end, the pressure of fluid (lubrication oil and gas) at the sealing position of the gearbox is continuously changed, and when the fluid caused by pressure change impacts the seals and when the fluid passes through an annular narrow gap of the throttle ring, pressure is reduced and the speed is increased, then the fluid suddenly expands in an annular cavity to generate a vortex, so that the pressure is reduced and energy is consumed. When the fluid passes through a plurality of comb teeth and then reaches the oil seal, kinetic energy of fluid is consumed completely, and thus the impact on a lip of the oil seal is avoided, therefore leakage is effectively avoided.
[0094] In conclusion, the combination of a contact-type sealing structure and a non-contact-type sealing structure not only provides four sealing solutions with various characteristics, but also the dustproof labyrinth sealing A has the effects of reducing particles from entering the contacting face of the packing seal B and delaying the abrasion of the contacting face, and the packing seal B has the effect of preventing external water vapor and the like from entering the oil seal C, which is helpful for preventing the contact lip from being corroded and abraded by external pollution; the throttling gap and an expansion cavity formed by a throttle ring sealing D can effectively inhibit pressure impact of fluid on a lip of the oil seal, and the leakage risk is greatly reduced. Such sealing solutions form an organic combination relation in a very limited and narrow space. Compared with the prior art, the sealing effect is obviously improved in both reliability and durability.
[0095] A wheel-side drive device of a wheel drive system is shown in FIG. 6, a frame 4 is fixed on a vehicle body, a traction motor 2 installed on the outer side of the frame 4 determines a rotation axis, and the inner output end of the motor 2 is in transmission connection with a torque tube 6 supported on the frame 4 through a gearbox 3. Therefore, the high-speed torque output by the traction motor 2 can be transmitted to the torque tube 6 after speed reduction and torque increase via the gearbox 3. A flange edge at the outer end of the torque tube 6 is fixed to the inner end of a hub 9 arranged outside a motor shell through an inner bearing 7 and an outer bearing 10 by fasteners, the outer end of the motor 2 is connected with a frame 4 via a brake assembly 1 and is connected with the outer end of the hub 9 to form an outer sealing device. The brake assembly 1 is composed of a brake clamp and a brake disc, wherein the brake clamp is connected with the frame 4, and the brake disc is connected with the outer end of the motor 2.
The basic structures are the same as the prior art and are not described in detail.
[0096] Two ends of the hub 9 are respectively sleeved and fixed at the outer end of the inner rim and the inner end of the outer rim 12. Specifically, the outer end of the inner rim 5 is provided with a wedge convergent 5-1, and the inner end of the hub 9 is provided with a wedge spigot 9-1 matched with the wedge convergent 5-1 and formed on one side of a radial epotaxial edge 9-3. The wedge spigot 9-1 and the pressing ring 8' pressing the outer end face of the inner rim 5 form a clamping structure to the wedge convergent 5-1 through a penetrating bolt, and the opposite end faces of the radial epotaxial edge 9-3 and the pressing ring 8' are provided with an edge ring concave 9-2 and a protruding ring 5-2 which are matched with each other respectively. Hence, the inner side and the outer side of the pressing ring 8' are guaranteed to be reliably pressed on the hub 9 and the inner rim 5 respectively.
[0097] An inner retaining ring 12-1 with a through hole extends from the vicinity of the inner end of the outer rim 12 towards the rotation axis, the inner retaining ring 12-1 is abutted against the outer end face of the radial outer edge 9-4 of the outer end of a hub 9, wherein the outer end face is provided with a threaded hole, and a bolt is screwed into the threaded hole of the hub 9 via the through hole of the inner retaining ring 12-1 to form a pressing and fastening structure.
[0098] One of the specific structures of the hub in the embodiment is shown in FIGs.9-1, 9-2 and 9-3. Two ends of the hub cylinder 9-6 respectively have a radial epotaxial edge 9-3 and a radial outer edge 9-4. A wedge spigot 9-1 matched with the wedge convergent 5-1 is formed on one side of the radial epotaxial edge 9-3, and a reducing connecting ring 9-7 extends from the other side of the radial epotaxial edge 9-3 in the axial direction. The reducing connecting ring 9-9 extends from the radial outer edge 9-4 in the axial direction. Through holes used for forming a clamping structure of the wedge convergent 5-1 with the pressing ring 8' through penetrating bolts are evenly distributed at intervals on the periphery of the end face of the radial epotaxial edge 9-3. Threaded holes used for fixing the torque tube 6 are evenly distributed at intervals on the periphery of the end face of the connecting ring 9-7. Threaded holes used for fixing an inner retaining ring 12-1 are evenly distributed on the periphery of the end face of the radial outer edge 9-4 at intervals, and threaded holes used for fixing an outer sealing device are evenly distributed on the periphery of the end face of the connecting ring 9-9. Reinforcing ribs 9-5 for connecting the radial epotaxial edge 9-3 and the radial outer edge 9-4 are evenly distributed on the surface of the outer circle of the hub cylinder 9-6 in the circumferential direction at intervals, and therefore the lightweight of the hub is achieved.
[0099] Another lightweight design of the hub in the embodiment is shown in FIGs.10-1, 10-2 and

10-3, and is different from the design in FIGs.9-1, 9-2 and 9-3 in that, reinforcing arcs 9-5' for connecting the radial epotaxial edge 9-3 and the radial outer edge 9-4 are evenly distributed outside the outer circle of the hub cylinder 9-6 at intervals in the circumferential direction.
[0100] During assembly, the inner rim 5 is firstly sleeved to the inner end of the hub 9 by contacting and locating the opposite wedge bevels, then the pressing ring 8' is sleeved, and the inner side and the outer side of the pressing ring 8' are reliably pressed on the hub 9 and the inner rim 5 by fasteners respectively; and then the outer rim 12 is sleeved to the inner retaining ring 12-1 to be abutted against the outer end of the hub 9, and the fastener is screwed into the threaded hole of the hub 9 to pressi and fasten the outer rim 12. And the disassembling steps are opposite and are very convenient.
[0101] According to the present embodiment, the hub, the inner rim and the outer rim are respectively and independently fixed, wherein the hub and the outer rim are completely connected by fasteners, and the hub and the inner rim are wedged tightly by a wedge bevel. Hence, the slipping risk of friction torque transmission is remarkably reduced, and the advantage of high radial bearing capacity is basically maintained. Also, a hub adapter is not required.
The embodiment has a simple structure and a simple manufacturing and assembling process.
[0102] The second wheel-side drive device of the wheel drive system is shown in FIG. 7, and the basic structure is the same as that shown in FIG. 6, what makes them different is that an inner fitting face 5-2' with through holes extends from the vicinity of the outer end of the inner rim 5 towards the rotation axis, a flange turnup 9-2' is arranged at the inner end of the hub 9, wherein the outer end face of the flange turnup 9-2' is attached to the inner end face of the inner fitting face 5-2' and a fastening structure is formed through a penetrating bolt and nut.
An inner retaining hoop 12-2 with through holes abutting against the outer end face of the hub 9 and provided with threaded holes extend towards the rotation axis from the vicinity of the inner end of the outer rim 12, and a bolt penetrates through the through hole of the inner retaining hoop 12-2 and the through hole of the outer sealing device at the same time and is screwed into the threaded hole on the periphery of the outer end face of the hub 9 to form a pressing and fastening structure, and a structure fixed to the outer sealing device.
[0103] One of the specific structures of the hub in the present embodiment is shown in FIGs.11-1,

11-2 and 11-3. Two ends of the hub cylinder 9-6 respectively have a radial epotaxial edge 9-3 and a radial outer edge 9-4; the end face of the radial epotaxial edge 9-3 is provided with through holes which are evenly distributed on the periphery at intervals and used for attaching the inner fitting face 5-2' through penetrating bolts to form a fixed structure, and threaded holes which are evenly distributed on the inner periphery at intervals and used for fixing the torque tube 6; the outer end face of the radial outer edge 9-4 is provided with threaded holes which are evenly distributed on the periphery at intervals and used for fastening the inner retaining hoop 12-2 and the outer sealing device at the same time. Reinforcing ribs 9-5 for connecting the radial epotaxial edge 9-3 and the radial outer edge 9-4 are evenly distributed on the surface of the outer circle of the hub cylinder 9-6 in the circumferential direction at intervals, and therefore the lightweight of the hub is achieved.
[0104] Another lightweight design of the hub in the embodiment is shown in Figs.12-1, Fig. 12-2 and Fig. 12-3, and is different from the design in Fig. 11-1, Fig. 11-2 and Fig. 11-3 in that reinforcing arcs 9-5' for connecting the radial epotaxial edge 9-3 and the radial outer edge 9-4 are evenly distributed at intervals in the circumferential direction outside the outer circle of the hub cylinder 9-6.
[0105] During assembly, the inner rim 5 is sleeved to the inner fitting face 5-2 to be attached to the flange turnup 9-2' at the inner end of the hub 9, the inner rim 5 and the inner fitting face 5-2' are fixedly connected by fasteners to form a fastening structure; and then the outer rim 12 is sleeved to the inner retaining hoop 12-2 to be abutted against the outer end of the hub 9, the fastener is screwed into threaded holes of the hub 9 to press and fasten the outer rim 12.
The disassembling steps are opposite.

101061 In this way, two ends of the hub are fixedly sleeved with the outer end of the inner rim and the inner end of the outer rim respectively. The advantages lie in that the hub is completely connected with the inner wheel rim and the outer wheel rim by the fasteners, so that the slipping phenomenon of friction torque transmission can be completely avoided, the stress of each bolt during clamping connection is only half of the original stress, and thus providing a better stress condition. The hub adapter is not required either. The embodiment has a simple structure and a simple manufacturing and assembling process.
101071 A third wheel-side drive device of the wheel drive system is shown in FIG. 8, the basic structure is the same as that shown in FIG. 6, the outer end of an inner rim 5 is provided with a wedge convergent 5-1 and the inner end of a hub 9 is provided with a wedge spigot 9-1 matching with the wedge convergent 5-1 formed on one side of a radial epotaxial edge 9-3, the inner end of an outer rim 12 is provided with a wedge convergent, and a bevel edge wedge ring 11' is provided at the outer end of the hub 9, and the bevel edge wedge ring 11' is provided with a wedge bevel matched with a wedge convergent in the inner end of the outer rim 12. The notable differences lie in: the outer end of the bevel edge wedge ring 11' is provided with a reducing spigot 11-2 for pressing the outer end of the hub 9, and a wedge plug 11-1 which is inserted into a radial spacing between the hub 9 and the outer rim 12 extends from the bevel edge inner end of the bevel edge wedge ring 11'. A wedge spigot 9-1 at the inner end of the hub 9 and a wedge bevel of an outer bevel edge wedge ring 11' form a clamping structure for two wedge convergents with a left clamping ring 8z and a right clamping ring 8y respectively, wherein the left clamping ring 8z and the right clamping ring 8y are pressed on the outer end face of the inner rim 5.
[0108] Specifically, step-shaped locking bolts 13 which penetrate through a right clamping ring 8y and a left clamping ring 8z and then are screwed into the radial epotaxial edge 9-3 of a hub 9 are installed in through holes evenly distributed in the circumferential direction of a bevel edge wedge ring 11'. The small-diameter section and the large-diameter section of each locking bolt 13 are provided with reverse threads for screwing a left nut 13z and a right nut 13y respectively, and a lock nut 14 is arranged at the outer end of each locking bolt 13. The non-circular profiles (such as hexagons) of the left nut 13z and the right nut 13y are matched with counter bores at the corresponding positions of the left clamping ring 8z and the right clamping ring 8y respectively to form a kinematic pair [0109] During assembly, the inner rim 5 is sleeved to the inner end of the hub 9 by contacting and locating the opposite wedge bevels, then the left clamping ring 8z is sleeved, the locking bolt 13 with the left nut 13z and the right nut 13y along with the right clamping ring Sy are preliminarily positioned in place. Once an outer rim 12 and a beveled edge wedge ring 11' are sleeved, the locking bolt 13 can be screwed into the radial epotaxial edge 9-3 of the hub 9 by means of an inner hexagonal concave part at the outer end of the locking bolt 13. At the moment, a left nut 13z and a right nut 13y move inwards and outwards at the same time under the action of a reverse thread kinematic pair. Firstly, an inner rim 5 is fixed by means of clamping of a wedge spigot 9-1 and a left clamping ring 8z, and then the lock nut 14 is screwed up. While fixing the outer rim 12 via clamping of the right clamping ring 8y and the bevel edge wedge ring 11', the thread pairs on the locking bolt 13 are mutually and tightly locked. The disassembling steps are opposite.
[0110] In this way, two ends of the hub are fixedly sleeved with the outer end of the inner rim and the inner end of the outer rim respectively. The advantages lie in that the inner wheel rim and the outer wheel rim are symmetrical and universal and the manufacturing is convenient. By installing a locking bolt from one end during assembly, the wheel rims can be wedged tightly via the wedge bevels by means of the two-way threads. The clamping ring can guarantee enough anti-slip clamping force, strict axial precision requirements are not required, radial bearing capacity is high, and the two reverse thread pairs have the effect of balancing the clamping force of the inner rim and the outer rim, so that the whole device is balanced and reasonable in stress.
[0111] A wheel-side drive hub of a wheel drive system is shown in FIGs.9-1, 9-2 and 9-3. Two ends of a cylindrical hub cylinder 9-6 respectively have a radial epotaxial edge 9-3 and a radial outer edge 9-4; a wedge spigot 9-1 matched with the wedge convergent 5-1 (see FIG. 6) of the inner rim 5 is formed on one side of the radial epotaxial edge 9-3, and a reducing connecting ring 9-7 extends from the other side of the radial epotaxial edge 9-3 in the axial direction. The reducing connecting ring 9-9 extends from the radial outer edge 9-4 in the axial direction; through holes used for forming a clamping structure of the wedge convergent 5-1 with the pressing ring 8' (see FIG. 6) through penetrating bolts are evenly distributed at intervals on the periphery of the end face of the radial epotaxial edge 9-3, and threaded holes used for fixing the torque tube 6 (see FIG.
6) are evenly distributed at intervals on the periphery of the end face of the connecting ring 9-7.
Threaded holes used for fixing an inner retaining ring 12-1 (see FIG. 6) are evenly distributed on the periphery of the end face of the radial outer edge 9-4 at intervals, and threaded holes used for fixing an outer sealing device (see FIG. 6) are evenly distributed on the periphery of the end face of the connecting ring 9-9. Reinforcing ribs 9-5 for connecting the radial epotaxial edge 9-3 and the radial outer edge 9-4 are evenly distributed on the surface of the outer circle of the hub cylinder 9-6 in the circumferential direction at intervals, and therefore the lightweight of the hub is achieved.
[0112] A wheel-side drive device adopting the hub of the present embodiment is shown in FIG. 6, a frame 4 is fixed on a vehicle body, a traction motor 2 installed on the outer side of the frame 4 determines a rotation axis, and the inner output end of the motor 2 is in transmission connection with a torque tube 6 supported on the frame 4 through a gearbox 3. Therefore, the high-speed torque output by the traction motor 2 can be transmitted to the torque tube 6 after speed reduction and torque increase via the gearbox 3. A flange edge at the outer end of the torque tube 6 is fixed to the inner end of a hub 9 arranged outside a motor shell through an inner bearing 7 and an outer bearing 10 by fasteners, the outer end of the motor 2 forms an external sealing connection with the outer end of the hub 9 via a brake assembly 1, the brake assembly 1 is composed of moving pieces and static pieces distributed at intervals, wherein the static pieces are connected with the frame 4, and the moving pieces are fixed to the outer end of the motor 2. These basic structures are the same as that of the prior art and are not described in detail.
[0113] Two ends of the hub 9 are respectively sleeved and fixed at the outer end of the inner rim 5 and the inner end of the outer rim 12. Specifically, the outer end of the inner rim 5 is provided with a wedge convergent 5-1, and the inner end of the hub 9 is provided with a wedge spigot 9-1 matched with the wedge convergent 5-1 and formed on one side of a radial epotaxial edge 9-3. The wedge spigot 9-1 and the pressing ring 8' pressing the outer end face of the inner rim 5 form a clamping structure to the wedge convergent 5-1 through a penetrating bolt, and the opposite end faces of the radial epotaxial edge 9-3 and the pressing ring 8' are provided with an edge ring concave 9-2 and a protruding ring 5-2 which are matched with each other respectively, so that the inner side and the outer side of the pressing ring 8' are guaranteed to be reliably pressed on the hub 9 and the inner rim 5 respectively.
[0114] An inner retaining ring 12-1 with a through hole extends from the vicinity of the inner end of the outer rim 12 towards the rotation axis, the inner retaining ring 12-1 is abutted against the outer end face of the radial outer edge 9-4 of the outer end of a hub 9, wherein the outer end face is provided with a threaded hole, and a bolt is screwed into the threaded hole of the hub 9 via the through hole of the inner retaining ring 12-1 to form a pressing and fastening structure.
[0115] During assembly, the inner rim 5 is firstly sleeved to the inner end of the hub 9 by contacting and locating the opposite wedge bevels, then the pressing ring 8' is sleeved, and the inner side and the outer side of the pressing ring 8' are reliably pressed on the hub 9 and the inner rim 5 by fasteners respectively; and then the outer rim 12 is sleeved to the inner retaining ring 12-1 to be abutted against the outer end of the hub 9, and the fastener is screwed into the threaded hole of the hub 9 to press and fasten the outer rim 12. And the disassembling steps are opposite and are very convenient.
[0116] According to the present embodiment, the hub is respectively and independently fixed to the inner rim and the outer rim, wherein the hub and the outer rim are completely connected by fasteners, and the hub and the inner rim are wedged tightly by a wedge bevel.
Hence, the slipping risk of friction torque transmission is remarkably reduced, and the advantage of high radial bearing capacity is basically maintained. Also, a hub adapter is not required. The embodiment has a simple structure and a simple manufacturing and assembling process.
[0117] Another hub of the wheel drive system is shown in Figs.10-1, 10-2 and 10-3, and is different from Fig. 9 in that reinforcing arcs 9-5' connecting the radial epotaxial edge 9-3 and the radial outer edge 9-4 are evenly distributed outside the outer circle of a hub cylinder 9-6 at intervals in the circumferential direction. Hence, the mass of the material can be distributed at the outer circle of the hub cylinder as much as possible, and better torque transmission performance is achieved.
101181 The hub of the present embodiment may also be applicable to the wheel drive shown in Fig.
6.
101191 Another wheel-side drive hub of the wheel drive system is shown in Figs.11-1, 11-2 and 11-3, wherein two ends of a hub cylinder 9-6 respectively have a radial epotaxial edge 9-3 and a radial outer edge 9-4. The end face of the radial epotaxial edge 9-3 is provided with through holes which are evenly distributed on the periphery at intervals and used for attaching an inner fitting face 5-2' (see FIG. 7) of an inner rim 5 through penetrating bolts to form a fixed structure, and threaded holes which are evenly distributed on the inner periphery at intervals and used for fixing a torque tube 6 (see FIG. 7) are provided. The outer end face of the radial outer edge 9-4 is provided with threaded holes which are evenly distributed on the periphery at intervals and used for fastening an inner retaining hoop 12-2 of the outer rim 12 and an outer sealing device (see FIG. 7) at the same time. Reinforcing ribs 9-5 for connecting the radial epotaxial edge 9-3 and the radial outer edge 9-4 are evenly distributed on the surface of the outer circle of the hub cylinder 9-6 in the circumferential direction at intervals, and therefore the lightweight of the hub is achieved.
101201 A wheel-side drive device adopting the hub of the present embodiment is shown in FIG. 7, which has the same basic structure as that of FIG. 6. They differ in that an inner fitting face 5-2' with through holes extends from the vicinity of the outer end of the inner rim 5 towards the rotation axis, wherein a flange turnup 9-2' is arranged at the inner end of the hub 9, and the outer end face of the flange turnup 9-2' is attached to the inner end face of the inner fitting face 5-2' and a fastening structure is formed through a penetrating bolt and nut. An inner retaining hoop 12-2 with through holes abutting against the outer end face of the hub 9 and provided with threaded holes extend towards the rotation axis from the vicinity of the inner end of the outer rim

12, wherein a bolt penetrates through the through hole of the inner retaining hoop 12-2 and the through hole of the brake assembly 1 at the same time and is screwed into the threaded hole on the periphery of the outer end face of the hub 9 to form a pressing and fastening structure and a structure fixed to the brake assembly 1.
[0121] During assembly, the inner rim 5 is sleeved to the inner fitting face 5-2' to be attached to the flange turnup 9-2' at the inner end of the hub 9, the inner rim 5 and the inner fitting face 5-2' are fixedly connected by fasteners to form a fastening structure; and then the outer rim 12 is sleeved to the inner retaining hoop 12-2 to be abutted against the outer end of the hub 9, the fastener is screwed into threaded holes of the hub 9 to press and fasten the outer rim 12.
The disassembling steps are opposite.
[0122] In this way, two ends of the hub are fixedly sleeved with the outer end of the inner rim and the inner end of the outer rim respectively. The advantages lie in that the hub is completely connected with the inner wheel rim and the outer wheel rim by the fasteners.
Hence, the slipping phenomenon of friction torque transmission can be completely avoided, the stress of each bolt during clamping connection is only half of the original stress, and thus providing a better stress condition. Also, a hub adapter is not required. The embodiment has a simple structure and a simple manufacturing and assembling process.
[0123] Another basic structure of the hub is the same as that of Fig. 11, as shown in Figs.12-1, 12-2 and 12-3, and the difference from Fig. 11 is that reinforcing arcs 9-5' connecting the radial epotaxial edge 9-3 and the radial outer edge 9-4 are evenly distributed outside the outer circle of a hub cylinder 9-6 at intervals in the circumferential direction. Hence, the mass of the material can be distributed at the outer circle of the hub cylinder as much as possible, and better torque transmission performance is achieved.
[0124] A hub structure of a wheel drive system is shown in FIGs.13-17, which includes a body 30 integrally formed in an integrally forged manner. The body includes an inner ring 34, a radial outer edge 9-4 and a radial epotaxial edge 9-3, wherein the radial outer edge 9-4 and the radial epotaxial edge 9-3 are located on either axial side of the inner ring 34, respectively, and the radial outer edge 9-4 and the radial epotaxial edge 9-3 both protrude from the inner ring 34 in the radial direction.
[0125] The hub further comprises an outer ring 31 which is located on the radial outer side of the inner ring in a radially spaced way, wherein the outer ring 31 and the inner ring 34 form a double layer structure, and the outer ring 31 is connected to the radial outer edge 9-4 and the radial epotaxial edge 9-3 by means of material bonding. Specifically, the outer ring 31 is fixed to the radial outer edge 9-4 and the radial epotaxial edge 9-3 by welding, and second welds 33 are formed between the outer ring 31 and the radial outer edge 9-4 and between the outer ring 31 and the radial epotaxial edge 9-3 respectively.
[0126] An annular cavity 35 is formed between the inner ring 34 and the outer ring 31.
[0127] The outer ring 31 includes a first outer ring portion 31-1 and a second outer ring portion 31-2 configured as a curved plate, wherein the first outer ring portion 31-1 and the second outer ring portion 31-2 are located at different positions in the circumferential direction of the hub and spliced into a ring (in other possible situations, the outer ring 31 is configured as an incomplete ring after being spliced, covering only a portion of the circumferential direction of the hub). The first outer ring portion 31-1 and the second outer ring portion 31-2 are connected with each other by welding, and a first weld 32 is formed between the first outer ring portion 31-1 and the second outer ring portion 31-2.
[0128] The through holes 36 are provided on the outer ring.
[0129] In the hub structure of the wheel drive system of the present invention, the first outer ring portion 31-1 and the second outer ring portion 31-2 can be of a columnar structure. Specifically, the size of the first outer ring portion 31-1 and the second outer ring portion 31-2 in the axial direction of the hub is larger than the size of the first outer ring portion 31-2 in the radial direction and/or the circumferential direction of the hub. The other technical features are the same as the embodiments described above. In the present embodiment, the columnar structure can be configured as a column-shaped, a rib-shaped or a rib-shaped structure which plays a reinforcing role.
[0130] From the above description, it can be seen that the hub structure of the present invention achieves the following technical effects:
[0131] 1. Compared with an integrally cast structure, the defects of cast looseness and the like generated in the smelting process of metal can be eliminated with forging, so that the microstructure structure is optimized. As a complete metal flow line is preserved with forging, the mechanical performance of the forge piece is generally better than that of a cast piece made of the same material, and thus the forge piece is suitable for environments with more severe working conditions.
[0132] 2. Compared with an integrally cast structure, the manufacturing cost of forging is reduced to a great extent relative to that of casting parts with the same structure.
For mass production of components, the cost can be reduced to a certain extent, and the cost performance is improved to a certain extent.
[0133] The basic structure of the lubrication device of the gearbox of the wheel drive system is shown in FIGs.18-24. One end of a horizontal shaft low-speed stage sun gear 39 is axially limited and supported by a first axial thrust ring 38 through a center shaft thereof, and the other end of the horizontal shaft low-speed stage sun gear 39 is axially limited and supported by a second axial thrust ring 46 with an end face counter bore. A first axial thrust ring 38 is embedded in a counter bore in the inner end of an end cover 37 of the box, and a second axial thrust ring 46 is sleeved at the sun gear reducing shaft end of a front stage 45 (high-speed stage).
[0134] A end cover 37 of the box is fixed on a (rotatable) low-speed planetary carrier 40 serving as a shell, a low-speed sun gear 39 is externally meshed with a low-speed planetary gear 41, the low-speed planetary gear 41 is internally meshed with a fixed gear ring 44, the low-speed planetary gear 41 is supported on a low-speed planetary pin shaft 42 through a low-speed planetary gear bearing 43, and the planetary pin shaft 42 is supported in pin holes evenly distributed in the circumference of the inner end face of the low-speed planetary carrier 40.

[0135] In combination with FIGs.19 and 20, it can be seen that an arc-shaped oil collecting box 37-1 which is located above the first axial thrust ring 38 and which is communicated with an oil outlet 37-3 in the bottom is fixed to the end cover 37 of the box, wherein the arc-shaped oil collecting box 37-1 is located between the outer ring of a counter bore in which the first axial thrust ring 38 is embedded and the inner circle of a flange ring of the end cover 37 of the box. The arc-shaped oil collecting box 37-1 is composed of a thin-wall metal plate welded to the end cover 37 of the box, and thus contributing to a simple and convenient manufacturing process. The oil collecting box 37-1 is provided with an end face oil inlet 37-2 which is adjacent to and directly faces the meshing position of the low-speed stage sun gear 39 and the low-speed stage planetary gear 41.
[0136] A first axial thrust ring 38 is shown in FIG. 21 and FIG. 22, the outer circle of the first axial thrust ring 38 is provided with an arc-bottom circumferential oil channel 38-1 corresponding to the oil outlet 37-3 in position and is provided with four arc-bottom end face oil grooves 38-3 which deepen from outside to inside and evenly distributed in the circumferential direction and extend in the radial direction, wherein the circumferential oil channel 32-1 is communicated with an inner hole thereof through radial oil holes 38-2 which are evenly distributed in the circumferential direction and correspond to the end face oil grooves 38-3 in angular position.
[0137] As shown in Fig. 23 and Fig. 24, the circumferential oil channels 38-1 are communicated with the end face oil grooves through axial oil channels 38-2' which are evenly distributed on the outer circle of the first axial thrust ring 38 in the circumferential direction and correspond to the end face oil grooves 38-3 in angular position.
[0138] Of course, on one hand, the circumferential oil channel 38-1 can be communicated with an inner hole thereof through radial oil holes 38-2 which are evenly distributed in the circumferential direction and correspond to the end face oil groove 38-3 in angular position.
On the other hand, it can be communicated with the end face oil groove through axial oil channels 38-2' which are evenly distributed on the outer circle of the first axial thrust ring 38 in the circumferential direction and correspond to the end face oil groove 38-3 in angular position.
[0139] The lubrication device provided by the present embodiment is provided with the oil collecting box and the lubricating channel, so that components and parts which are difficult to be splashed for lubrication at a low speed can be fully lubricated, thereby meeting the use requirement of ensuring the normal operation of the gearbox for a long time. The device is simple in structure and low in cost. Practice shows that the lubricating problem that components and parts are difficult to be lubricated by a conventional method due to the fact that the improper internal position of the gearbox can be effectively solved.
[0140] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and variations of the present invention will occur to those skilled in the art. Any modifications, equivalents, improvements, etc., made within the spirit and principles of the present invention are intended to be included within the scope of the present invention.

Claims

1. A wheel drive system, comprising a wheel-side reducer with a frame and a torque tube connected to a wheel and a sealing structure provided between the frame and the torque tube, wherein the sealing structure comprises a static ring fixed to the frame and a moving ring disposed opposite to the static ring and fixed to the torque tube, characterized in that, a plurality of annular rings are provided on an end face of the static ring in the radial direction from outside to inside, wherein an inner circle of the innermost annular ring is tightly fitted with a throttle ring and an oil seal;
and the moving ring comprises a lower edge inner ring, wherein an outer circle of the lower edge inner ring forms an oil sealing by contacting the oil seal, and forms a throttle ring sealing at a position opposite to the throttle ring.

2. The wheel drive system according to claim 1, wherein the throttle ring includes a set of radially extending comb teeth which are spaced axially.

3. The wheel drive system according to claim 2, wherein a thickness of the comb tooth is substantially the same as a width of a gap between the comb teeth, and wherein a length of the comb tooth is 2-2.5 times the thickness of the comb tooth.

4. The wheel drive system according to claim 1, wherein one end of the throttle ring adjacent to the oil seal is provided with a limiting protrusion.

5. The wheel drive system according to claim 1, wherein at least three annular rings are provided on the end face of the static ring in the radial direction from outside to inside, and the outer circle of the innermost annular ring is provided with a clamping groove for embedding a seal; and wherein ring protrusions provided on the end face of the moving ring in the radial direction from outside to inside are embedded between the adjacent annular rings to form radial labyrinth sealing, and an inner circumferential surface of the ring protrusions opposite to the clamping groove forms an oil sealing by contacting the seal.

6. The wheel drive system according to claim 1, further comprising a hub, wherein two ends of the hub are fixedly sleeved with an outer end of an inner rim and an inner end of an outer rim, respectively.

7. The wheel drive system according to claim 6, wherein the outer end of the inner rim has a wedge convergent and the inner end of the hub has a wedge spigot matching with the wedge convergent, and wherein the wedge spigot and a pressing ring or a clamping ring which is pressed on the outer end face of the inner rim form a clamping structure to the wedge convergent through a penetrating bolt.

8. =The wheel drive system according to claim 6, wherein an inner fitting face with a through hole extends from the vicinity of the outer end of the inner rim towards the rotation axis, the inner end of the hub has a flange turnup, and the outer end face of the flange turnup fits the inner end face of the inner fitting face to form a fastening structure by a penetrating fastener.

9. The wheel drive system according to claim 6, wherein an inner retaining ring or an inner retaining hoop with a through hole abutting against the outer end face of the hub with the threaded hole extends from the vicinity of the inner end of the outer rim towards the rotation axis, and wherein the fastener is screwed into the threaded hole of the hub via the through hole of the inner retaining ring or the inner retaining hoop to form a pressing and fastening structure.

10. The wheel drive system according to claim 6, wherein the inner end of the outer rim has a wedge convergent, and the outer end of the hub is fitted with a bevel edge wedge ring which has a wedge bevel matching with the wedge convergent of the inner end of the outer rim; wherein the outer end of the bevel edge wedge ring presses the outer end of the hub has with a reduced diameter, and a wedge plug extends from the bevel edge inner end of the bevel edge wedge ring is inserted into a radial spacing between the hub and an outer rim; and wherein the wedge bevel and the right clamping ring form a clamping structure to the wedge convergent.

11. The wheel drive system according to claim 10, wherein the outer end of the inner rim is provided with a wedge convergent and the inner end of the hub is provided with a wedge spigot matching with the wedge convergent formed on one side of the radial epotaxial edge, the wedge spigot and a left clamping ring which is pressed on the outer end face of the inner rim form a clamping structure to the wedge convergent through a penetrating bolt; wherein a step-shaped locking bolt which penetrates through the right clamping ring and the left clamping ring and then is screwed into the radial epotaxial edge is fitted in a through hole of the bevel edge wedge ring, a small-diameter section and a large-diameter section of the locking bolt are provided with reverse threads for screwing a left nut and a right nut respectively, and a lock nut is arranged at the outer end of the locking bolt; the non-circular profiles of the left nut and the right nut are respectively matched with counter bores at corresponding positions of the left clamping ring and the right clamping ring to form a kinematic pair.

12. The wheel drive system according to claim 1, further comprising a hub, wherein two ends of the hub are configured as a radial epotaxial edge and a radial outer edge respectively, and outer ring through holes and inner ring threaded holes are evenly distributed on the periphery of the end face of the radial epotaxial edge at intervals; and wherein at least one circle of threaded holes are evenly distributed at the periphery of the end face of the radial outer edge at intervals.

13. The wheel drive system according to claim 1, further comprising a hub, wherein the hub includes a body having an inner ring, a radial outer edge, and a radial epotaxial edge, the radial outer edge and the radial epotaxial edge are located respectively on two axial sides of the inner ring, and the radial outer edge and the radial epotaxial edge both protrude from the inner ring in the radial direction, wherein the wheel drive system further comprises an outer ring which is located on the radial outer side of the inner ring in a radially spaced way and which is fixed to the radial outer edge and the radial epotaxial edge.

14. The wheel drive system according to claim =13, wherein the body is integrally formed and the outer ring is connected to the body through material bonding.

15. =The wheel drive system according to claim =14, wherein the outer ring is fixed to the radial outer edge and the radial epotaxial edge by welding.

16. =The wheel drive system according to claim =14, wherein the body is integrally forged into one piece.

17. The wheel drive system according to claim =13, wherein an annular cavity is provided between the inner ring and the outer ring.

18. The wheel drive system according to claim 13, wherein the outer ring comprises a first outer ring portion and a second outer ring portion, the first outer ring portion and the second outer ring portion being located at different positions circumferentially of the hub.

19. =The wheel drive system according to claim 18, wherein the first outer ring portion and the second outer ring portion are columnar reinforcing structures, the dimensions of the first outer ring portion and the second outer ring portion along the axial direction of the hub being greater than the dimensions of the first outer ring portion and the second outer ring portion along the radial and/or circumferential direction of the hub.

20. The wheel drive system according to claim 18, wherein the first outer ring portion and the second outer ring portion are configured as a curved plate.

21. The wheel drive system according to claim 20, wherein the first outer ring portion and the second outer ring portion are interconnected by welding.

22. The wheel drive system according to claim 13, wherein the outer ring covers only a portion of the circumference of the hub.

23. The wheel drive system according to any one of claim 13, wherein the outer ring has through holes thereon.

24. The wheel drive system according to claim 1, further comprising a gearbox lubrication device which includes a horizontal shaft sun gear with two ends axially limited and supported by a first axial thrust ring and a second axial thrust ring respectively; wherein the first axial thrust ring is embedded in a counter bore at the inner end of an end cover of the box, the end cover of the box is fixed on a planetary carrier serving as a shell in a sealing and covering manner, the sun gear is externally meshed with the planetary gear, the planetary gear is internally meshed with the fixed gear ring, the planetary gear is supported on a planetary pin shaft through a planetary gear bearing; and wherein an oil collecting box which is located above the first axial thrust ring and communicated with the bottom oil outlet is fixed to the end cover of the box, and the oil collecting box is provided with an oil inlet which is close to and directly faces the meshing position between the sun gear and the planetary gear; the outer circle of the first axial thrust ring is provided with a circumferential oil channel corresponding to the oil outlet in position and an end face oil groove extending in the radial direction, the circumferential oil channel is at least communicated with an inner hole of the circumferential oil channel through a radial oil hole or communicated with the end face oil groove through an axial oil channel.

25. A combined sealing structure of a wheel-side reducer, comprising a static ring fixed to the frame and a moving ring disposed opposite to the static ring and fixed to the torque tube, characterized in that, at least three annular rings are provided on the end face of the static ring in the radial direction from outside to inside;
wherein a clamping groove for embedding packing is formed in the outer circle of the innermost annular ring, an inner circle of the innermost annular ring is tightly fitted with a throttle ring and an oil seal, the throttle ring has a set of radially extending comb teeth which are axially spaced; wherein the end face of the moving ring is provided with an ring protrusion embedded between the adjacent annular rings to form radial labyrinth sealing in the radial direction from outside to inside and a lower edge inner ring;
the inner circumferential surface of the ring protrusion opposite to the clamping groove contacts the packing to form packing seal; and wherein the outer circle of the lower edge inner ring forms an oil sealing by contacting the oil seal and forms a throttle ring sealing at a position opposite to the throttle ring.

26. The combined sealing structure of the wheel-side reducer according to claim 25, wherein a thickness of the comb tooth is substantially the same as a width of a gap between the comb teeth, a length of the comb tooth is 2-2.5 times the thickness of the comb teeth.

27. =The combined sealing structure of the wheel-side reducer according to claim 25, wherein one end of the throttle ring adjacent to the oil seal is provided with a limiting protrusion.

28. A wheel-side drive device, comprising a motor mounted on an outer side of a frame for determining an rotation axis, an inner output end of the motor being in transmission connection with a torque tube supported on the frame through a gearbox;
wherein the torque tube is fixed to the inner end of a hub sleeved outside the motor, and the outer end of the motor is connected with the frame via a brake assembly and is connected with the outer end of the hub to form an outer sealing device; characterized in that, two ends of the hub are fixedly sleeved with the outer end of the inner rim and the inner end of the outer rim respectively.

29. The wheel-side drive device according to claim 28, wherein the outer end of the inner rim has a wedge convergent and the inner end of the hub has a wedge spigot matching with the wedge convergent, and wherein the wedge spigot and a pressing ring which is pressed on the outer end face of the inner rim form a clamping structure to the wedge convergent through a penetrating bolt; an inner retaining ring with a through hole abutting against the outer end face of the hub with the threaded hole extends from the vicinity of the inner end of the outer rim towards the rotation axis, and wherein the fastener is screwed into the threaded hole of the hub via the through hole of the inner retaining ring to form a pressing and fastening structure.

30. The wheel-side drive device according to claim 28, wherein an inner fitting face with a through hole extends from the vicinity of the outer end of the inner rim towards the rotation axis, the inner end of the hub has a flange turnup, and the outer end face of the flange turnup attaches to the inner end face of the inner fitting face to form a fastening structure by a penetrating fastener; an inner retaining hoop with a through hole abutting against the outer end face of the hub with the threaded hole extends from the vicinity of the inner end of the outer rim towards the rotation axis, and the fastener is screwed into the threaded hole of the outer end face of the hub via the through hole of the inner retaining hoop to form a pressing and fastening structure.

31. The wheel-side drive device according to claim 28, wherein the outer end of the inner rim has a wedge convergent and the inner end of the hub has a wedge spigot matching with the wedge convergent formed on one side of the radial epotaxial edge;
the inner end of the outer rim has a wedge convergent and the outer end of the hub is fitted with a bevel edge wedge ring which has a wedge bevel matching with the wedge convergent of the inner end of the outer rim; wherein the outer end of the bevel edge wedge ring presses the outer end of the hub has with a reduced diameter, and a wedge plug extends from the bevel edge inner end of the bevel edge wedge ring is inserted into a radial spacing between the hub and an outer rim; the wedge spigot at the inner end of the hub and the wedge bevel of the outer bevel edge wedge ring of the hub form a clamping structure to wedge convergents at two sides with the left clamping ring and the right clamping ring which are pressed on the outer end face of the inner rim respectively.

32. The wheel-side drive device according to claim 31, wherein a step-shaped locking bolt which penetrates through the right clamping ring and the left clamping ring and then is screwed into the radial epotaxial edge is fitted in a through hole of the bevel edge wedge ring, a small-diameter section and a large-diameter section of the locking bolt are provided with reverse threads for screwing a left nut and a right nut respectively, and a lock nut is arranged at the outer end of the locking bolt; the non-circular profiles of the left nut and the right nut are respectively matched with counter bores at corresponding positions of the left clamping ring and the right clamping ring to form a kinematic pair.

33. A wheel-side drive hub, comprising a hub cylinder, wherein two ends of the hub cylinder are configured as a radial epotaxial edge and a radial outer edge respectively;
characterized in that, the outer ring through holes and the inner ring threaded holes are evenly distributed on the periphery of the end face of the radial epotaxial edge at intervals; and wherein at least one circle of threaded holes are evenly distributed at the periphery of the end face of the radial outer edge at intervals.