Multi-piston parking integrated wet brake, connecting structure, rear axle and electric transmission mine dump truck

Abstract

This invention discloses a multi-piston integrated wet brake for both driving and parking, a connecting structure, a rear axle, and an electric drive mining dump truck, relating to the field of engineering machinery technology. It includes: a brake housing; a drive disc combined with the brake housing to form a brake cavity; a brake assembly; several driving piston assemblies distributed around the brake housing for pressing the brake assembly during driving; and several parking piston assemblies distributed around the brake housing, normally closed to press the brake assembly for parking. By using multiple circumferentially distributed driving pistons and multiple circumferentially distributed parking pistons instead of the traditional single-piston design, the uniformity of piston thrust distribution on the friction plate is improved, thereby reducing wear and increasing the service life of the friction plates. Furthermore, both the driving and parking pistons use a small-sized piston design, which, compared to traditional large-sized piston wet brakes, reduces manufacturing costs and simplifies assembly and maintenance.

Description

Technical Field

[0001] This invention relates to the field of engineering machinery technology, specifically to a multi-piston integrated wet brake, a connecting structure, a rear axle, and an electric drive mining dump truck. Background Technology

[0002] Currently, there are two main technical approaches to the wheel-side braking systems of electric drive mining dump trucks: caliper disc brakes and wet brakes. Based on the integration of driving and parking functions, wet brakes can be further divided into separate driving and parking brakes and integrated driving and parking brakes. Separate driving and parking brakes employ a separate design for driving and parking braking, with the wet driving brake installed at the frame and wheel hub, and the wet parking brake installed at the high-speed end of the motor, independently controlling the driving and parking braking of the mining truck. Integrated driving and parking brakes, on the other hand, integrate driving and parking braking functions into a single wet brake unit, installed at the frame and wheel hub.

[0003] Existing technologies for improving wet brake performance focus primarily on optimizing single brake functions, such as piston structure, drive method, cooling strategy, and wear monitoring. They do not clearly reveal or address how to achieve a highly integrated design for both service and parking brake systems to meet the higher demands for lightweighting, integration, and reliability in electric drive dump trucks. The main problems are as follows: The structure is complex, installation is inconvenient, and sealing reliability is low. Traditional heavy-duty mining dump trucks mostly use separate wet brake systems for driving and parking, controlling driving and parking through two independent braking systems. The driving brake is mounted on the frame and connected to the wheel hub through the brake assembly; the parking brake is mounted on the high-speed end of the motor, making it prone to brake failure due to high-speed braking. The driving and parking brakes work on similar principles, with independent driving and parking pistons pushing the brake disc and pressing the brake assembly to achieve braking. Compared to caliper disc brakes, the oil cooling technology of wet brakes improves the working environment of the brake assembly and solves the problems of insufficient heat dissipation and low braking reliability to some extent. However, the use of two independent separate brake systems results in low technical integration and large space occupation. Coupled with redundant rear axle housings, pressure plates, and other structural components, the braking system is heavy, has a long axial dimension, and low space utilization, which does not take advantage of the lightweight design of mining dump trucks, and is also inconvenient to install. Furthermore, the split design of wet brakes increases the number of structural components and the complexity of connections, leading to potential sealing failures and increased risks of component interference. For example, traditional wet brakes are fixed to the frame and wheel hub on both sides by bolts, requiring the removal of numerous connecting bolts during maintenance, resulting in a large workload. Under the harsh conditions of heavy-load and bumpy mining operations, where mine cars are subjected to high-frequency alternating stress and ground impact loads, the bolts connecting the brake to the frame are prone to elongation and breakage, leading to brake oil leaks and affecting driving safety.

[0004] Uneven distribution of braking pressure on the braking assembly, high piston manufacturing costs, and difficult assembly / disassembly all contribute to the problem. Wet brakes can be categorized into single-piston and multi-piston types based on the number of pistons. Single-piston wet brakes rely solely on a large piston to push the friction pad pressure plate, which can easily lead to pressure plate warping. This results in uneven circumferential distribution of the clamping force on the braking assembly, accelerating friction pad wear and affecting friction pad life and braking smoothness. Furthermore, traditional wet brakes often use large pistons, leading to high manufacturing costs and significant assembly / disassembly difficulties.

[0005] The parking brake has a high risk of failure and insufficient safety redundancy. The parking brake design of wet brake systems relies on the continuous thrust of hydraulic oil on the piston. In extreme cases where hydraulic oil leaks in the parking hydraulic oil passages, the parking piston will be in a normally closed state, making it impossible to release the parking brake. Summary of the Invention

[0006] The purpose of this invention is to provide a multi-piston integrated wet brake, a connecting structure, a rear axle, and an electric drive mining dump truck to solve the problems in the prior art mentioned in the background section.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A multi-piston integrated wet brake, comprising: Brake housing; A drive disc, which, together with the brake housing, forms a brake cavity; A braking assembly is installed in a braking cavity formed by the brake housing and the drive disc. When the braking assembly is pressed, the rotational power of the drive disc is cut off. A traveling piston assembly, wherein a plurality of traveling piston assemblies are distributed around the brake housing, for pressing the brake assembly for braking during driving; A parking piston assembly, wherein several parking piston assemblies are distributed around the brake housing, and normally closed to press the brake assembly for braking when parked.

[0008] Preferably, the brake housing is provided with an inner cooling oil passage and an outer cooling oil passage; The brake housing is fitted with a cover plate on one side of the cooling oil passage; The cover plate is provided with an inner cooling oil passage outlet corresponding to the inner cooling oil passage and an outer cooling oil passage inlet corresponding to the outer cooling oil passage; The drive disk has multiple sets of circumferentially distributed internal cooling oil passage inlets that connect the inner and outer annular surfaces. Cooling oil enters the external cooling oil passage through the external cooling oil passage inlet, flows to the cooling oil chamber through the external cooling oil passage outlet, and is thrown into the internal cooling oil passage from the internal cooling oil passage inlet as the drive disc rotates to force cooling of the brake assembly area. The cooled oil after heat exchange is discharged from the internal cooling oil passage outlet.

[0009] Preferably, cooling oil cover plates are installed on the inner cooling oil passage outlet and the outer cooling oil passage inlet; The cooling oil cover is fixed to the cover plate by cover plate bolts.

[0010] Preferably, the braking assembly is further provided with a large end cap and a braking pressure plate on both sides; The brake assembly is pressed against the brake plate by the extension of the driving piston assembly and / or the parking piston assembly.

[0011] Preferably, the driving piston assembly includes: The travel piston is installed in the groove of the brake housing; The traveling piston is fixed to the brake pressure plate by a traveling piston fixing bolt; A guide sleeve is installed inside the traveling piston; The outer ring of the guide sleeve is coaxially mounted with a travel spring and a travel baffle, and the two ends of the travel spring are axially limited by the guide sleeve and the travel baffle, respectively. The driving baffle is axially limited by a driving snap ring; The inner ring of the guide sleeve is interference-fitted with the travel piston pin, and the other end of the travel piston pin is fixed to the brake housing. The brake housing on the side of the traveling piston near the brake assembly is provided with a sealing ring, a T-shaped seal, and a guide ring.

[0012] Preferably, the parking piston assembly includes: The parking piston is installed in the groove of the brake housing; The parking piston is coaxially provided with a parking threaded sleeve on the side near the brake pressure plate, and a parking expansion sleeve is fitted between the parking threaded sleeve and the parking piston. One side of the parking expansion sleeve is axially limited by a parking retaining ring installed in the inner ring groove of one end of the parking piston, and the other side of the parking expansion sleeve is axially limited by a parking positioning pin. The parking threaded sleeve is fixed to the brake pressure plate by a parking fixing bolt; The other side of the parking piston is connected to one side of the parking end cover, with an axial gap between them; The annular space formed by the parking piston and the parking end cover is provided with several stacked parking disc springs.

[0013] Preferably, the parking expansion sleeve and the parking piston are slidably connected via an inclined surface, and the parking expansion sleeve and the parking threaded sleeve are connected via threads; and / or The parking expansion sleeve has a male thread inside, and the parking threaded sleeve has a female thread on its outer ring. Both the male and female threads have right-angled trapezoidal cross-sectional shapes; and / or The parking bolt is also fitted with a parking spring, one end of which abuts against the head of the parking bolt, and the other end abuts against the parking threaded sleeve to form an axial limit.

[0014] Preferably, a cover plate is installed on one side of the brake housing; The brake housing and the cover plate are respectively provided with annular grooves; The brake housing and the cover plate are combined to close two annular grooves, which respectively form the driving hydraulic oil passage and the parking hydraulic oil passage. The travel hydraulic oil passage is connected to the travel piston assembly and the brake housing through the travel exhaust branch to form a closed travel piston hydraulic oil chamber. The hydraulic oil passage of the vehicle is also connected to one of the main exhaust channels of the vehicle, and the other two channels of the main exhaust channels of the vehicle are the oil inlet and oil return port of the hydraulic oil of the vehicle. The parking hydraulic oil passage is connected to the parking piston assembly, the brake housing and the brake pressure plate through the parking exhaust branch to form a closed parking piston hydraulic oil chamber; The parking hydraulic oil passage is also connected to one of the parking exhaust main passages, and the other two passages of the parking exhaust main passage are the parking hydraulic oil inlet and outlet.

[0015] Preferably, the braking assembly includes: a steel sheet and a buffer sheet with splines evenly distributed in the circumferential direction on the outer ring, and a friction sheet with splines evenly distributed in the circumferential direction on the inner ring. The braking assembly consists of alternating friction plates and steel plates in the middle, and two sets of buffer plates at both ends; The friction plate and the drive disc are splinedly engaged, and the buffer plate and the steel plate are splinedly engaged with the brake housing.

[0016] Preferably, the friction pad has alternating grooves on both sides; and / or The contact surfaces of the buffer sheet with the large end cap and the brake pressure plate are provided with wear-resistant thick pads made of composite materials.

[0017] A parking integrated connection structure, comprising: The aforementioned multi-piston travel-parking integrated wet brake; A frame, wherein the frame is connected by a spline and mounts the multi-piston travel-parking integrated wet brake; The hub is rotatably connected to the frame and the multi-piston travel-parking integrated wet brake.

[0018] Preferably, the bearing spacer is fitted onto the outer ring of the frame; The hub is splinedly driven by the drive disc and is axially limited by bearings; A sealing groove is provided at the connection between the wheel hub and the large end cap, and a large floating oil seal is installed at this location. A sealing groove is provided at the connection between the inner ring of the drive disc and the bearing spacer, and a small floating oil seal is installed between the drive disc and the bearing spacer.

[0019] Preferably, the end face of the multi-piston integrated wet brake and the frame boss are provided with several limiting baffles.

[0020] Preferably, the limiting baffle is fixed to the brake housing by limiting baffle bolts; A pad is provided between the limiting baffle and the brake housing. The pad has a recess corresponding to the installation position of the limiting baffle, and a rubber pad is installed in the recess.

[0021] A rear axle, comprising: frame; Rear axle housing, on which the frame is connected; An electric motor, which is installed in the rear axle housing as a power source for driving; A hub, which is axially constrained on the frame by a bearing; A rim, which is mounted on the hub; A tire, which is mounted on the rim; The rear axle also features a multi-piston integrated wet brake via the aforementioned integrated driving and parking connection structure.

[0022] An electric drive mining dump truck, wherein the aforementioned rear axle is installed.

[0023] Compared with the prior art, the beneficial effects of the present invention are: The brake system adopts a multi-piston integrated design for both driving and parking, improving the integration of the brake structure, reducing the number of structural components, complexity, and space occupancy, and solving the problems of complex structure and inconvenient installation of traditional split wet brakes. The left and right sides of the brake housing are connected to the wheel hub and frame respectively via spline connections, shortening the axial length of the brake, reducing space occupation, and improving ease of assembly and disassembly. A limit baffle and rubber gasket on the right side of the brake housing reduce the impact and wear caused by movement in the spline connection, improving transmission smoothness. Simultaneously, the spline connection avoids oil leakage caused by broken connecting bolts in traditional brakes, thus improving the brake's sealing performance. Sealing rings and floating oil seals are used at component connections to improve the sealing performance of brake cooling oil and hydraulic oil, ensuring reliable sealing. Floating oil seals are installed at the connection between the large end cap and the wheel hub, and at the connection between the drive disc and the bearing spacer. O-rings are installed on both sides of the oil passages, effectively reducing the risk of leakage of cooling oil and brake hydraulic oil. In addition, the integrated design of the driving and parking brakes means that the brakes are not installed on the high-speed end of the motor, which can effectively avoid the braking failure problem caused by the high-speed braking of the parking brake in traditional split brakes and improve braking reliability.

[0024] By employing multiple circumferentially distributed traveling pistons and multiple circumferentially distributed parking pistons instead of the traditional single-piston design, the uniformity of piston thrust distribution on the friction plate is improved, thereby reducing wear and extending the service life of the friction plates. Furthermore, both the traveling and parking pistons utilize a small-sized piston design, which, compared to traditional large-sized piston wet brakes, reduces manufacturing costs and simplifies assembly and maintenance.

[0025] The parking end cover has an internal hexagonal screw hole on one side and a through hole at the corresponding axial position of the cover plate. This can effectively solve the problem of the brake locking due to leakage of hydraulic oil from the parking piston and the inability to release the parking brake, thereby reducing the risk of parking brake failure, enhancing the safety redundancy of the parking brake, and improving the operational reliability of the electric drive mining dump truck. Attached Figure Description

[0026] The accompanying drawings, as part of this invention, are provided to further illustrate the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention, but do not constitute an undue limitation thereof. Clearly, the drawings described below are merely some embodiments, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0027] Figure 1 This is a perspective view of the multi-piston integrated wet brake of the present invention. Figure 2 This is a cross-sectional view of the multi-piston integrated wet brake of the present invention located on the frame; Figure 3 This is a left view of the multi-piston integrated wet brake of the present invention; Figure 4 This is a cross-sectional view of the installation position of the multi-piston integrated wet brake assembly of the present invention. Figure 5 This is a structural diagram of the buffer plate of the brake assembly of the multi-piston traveling and parking integrated wet brake of the present invention; Figure 6 This is a structural diagram of the friction pad of the multi-piston integrated wet brake assembly of the present invention. Figure 7 This is a structural diagram of the steel sheet of the multi-piston integrated wet brake assembly of the present invention. Figure 8 This is a cross-sectional view of the braking assembly of the multi-piston integrated wet brake of the present invention. Figure 9 This is a cross-sectional view of the multi-piston integrated wet brake assembly and the vehicle piston assembly of the present invention. Figure 10 for Figure 9 A magnified view of position I in the middle; Figure 11 This is a cross-sectional view of the multi-piston integrated wet brake assembly and parking piston assembly of the present invention. Figure 12 for Figure 11 A magnified view of position I in the middle; Figure 13 This is a cross-sectional view of the parking exhaust port of the multi-piston integrated wet brake of the present invention. Figure 14 This is a cross-sectional view of the cooling oil passage inside the multi-piston integrated wet brake of the present invention. Figure 15 This is a cross-sectional view of the external cooling oil passage of the multi-piston integrated wet brake of the present invention. Figure 16 This is a right view of the multi-piston integrated wet brake of the present invention; Figure 17 for Figure 9 Enlarged view of position II in the middle; Figure 18 for Figure 9 Enlarged view of position III in the middle; Figure 19 This is a schematic diagram of the multi-piston integrated wet brake of the present invention installed on the rear axle.

[0028] In the diagram, 1. Frame; 2. Multi-piston integrated wet brake; 3. Wheel hub; 4. Wheel rim; 5. Tire; 6. Motor; 7. Rear axle housing; 8. Bearing; 9. Sealing groove.

[0029] 2. The multi-piston integrated wet brake for both driving and parking includes: 21. Internal cooling oil passage outlet; 22. Internal cooling oil passage; 23. Internal cooling oil passage inlet; 24. External cooling oil passage inlet; 25. External cooling oil passage; 26. External cooling oil passage outlet; 27. Driving hydraulic oil passage; 28. Driving exhaust main passage; 29. ​​Parking hydraulic oil passage; 30. Parking exhaust main passage; 32. Driving piston hydraulic oil chamber; 33. Parking piston hydraulic oil chamber; 34. Parking exhaust branch passage; 35. Driving exhaust branch passage. 201. Cover plate; 202. Brake housing; 203. Cooling oil cover plate; 204. Limiting baffle; 205. Rubber pad; 206. Gasket plate; 208. Cover plate bolt one; 209. Cover plate bolt two; 210. Baffle bolt; 211. Baffle screw; 212. Traveling piston assembly; 213. Parking piston assembly; 214. Large O-ring of traveling oil passage; 215. Middle O-ring of traveling oil passage; 216. O-ring of parking oil passage; 217. T-seal; 218. Sealing retainer ring; 219. Guide ring; 220. Small parking seal ring; 221. Parking brake large seal ring; 222. Brake pressure plate; 223. Baffle; 224. Socket head bolt; 225. Drive disc; 226. Drive disc rectangular ring; 227. Drive disc O-ring; 228. Brake assembly; 229. Large floating oil seal; 230. Bearing spacer; 231. Bearing spacer O-ring; 232. Large end cap; 233. Oil plug; 234. Safety stud; 235. Safety nut; 236. Large end cap gasket; 237. Large end cap bolt; 238. Cover plate bolt; 239. Small oil plug; 240. Small floating oil seal.

[0030] 212. The traveling piston assembly includes: 212-1, traveling piston retaining bolt; 212-2, traveling piston; 212-3, guide sleeve; 212-4, traveling spring; 212-5, traveling piston pin; 212-6, traveling brake plate; 212-7, traveling snap ring.

[0031] 213. The parking piston assembly includes: 213-1, parking retaining bolt; 213-2, parking spring; 213-3, parking threaded sleeve; 213-4, parking retaining ring; 213-5, parking expansion sleeve; 213-6, parking locating pin; 213-7, parking piston; 213-8, parking disc spring; 213-9, parking end cap.

[0032] 228. The braking assembly includes: 228-1, buffer pad; 228-2, friction pad; 228-3, steel sheet. Detailed Implementation

[0033] To enable those skilled in the art to better understand the present invention, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention. It should be understood that the various steps described in the method embodiments of the present invention can be performed in different orders and / or in parallel. Furthermore, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present invention is not limited in this respect.

[0034] The term "comprising" and its variations as used herein are open-ended inclusions, meaning "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". Definitions of other terms will be given in the description below.

[0035] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, any variations of the terms "comprising" and "having," etc., are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0036] It should be noted that the terms "a" and "a plurality of" used in this invention are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0037] The names of the messages or information exchanged between the multiple devices in the embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of these messages or information.

[0038] Example 1

[0039] like Figure 1 As shown, a multi-piston integrated wet brake for driving and parking includes: a brake housing 202, a drive disc 225, a brake assembly 228, a driving piston assembly 212, and a parking piston assembly 213.

[0040] The drive disc 225 and the brake housing 202 are combined to form a brake cavity.

[0041] As a further explanation: Figure 2 As shown, the brake assembly 228 is also provided with a large end cap 232 and a brake pressure plate 222 on both sides; the brake assembly 228 is pressed by the brake pressure plate 222 through the extension of the driving piston assembly 212 and / or the parking piston assembly 213.

[0042] In this embodiment: as Figure 3 As shown, the large end cap 232 is connected to the brake housing 202 via a large end cap bolt 237 and a safety stud 234. A large end cap washer 236 is installed between the large end cap bolt 237 and the large end cap 232; one end of the safety stud 234 connects the large end cap 232 and the brake housing 202, and the other end is fastened to a safety nut 235. Because the large end cap 232 presses against the driving piston assembly 212 and the parking piston assembly 213, it bears a large axial spring force from the bicycle spring 212-4, the parking spring 213-2, and the parking disc spring 213-8. Therefore, when disassembling the large end cap 232, the safety of brake disassembly and assembly can be improved by gradually and sequentially removing the large end cap bolt 237 and the safety stud 234.

[0043] like Figure 4 As shown, the braking assembly 228 is installed in the brake housing 202 and the drive disc 225 to form a braking cavity. When the braking assembly 228 is pressed, the rotational power of the drive disc 225 is cut off.

[0044] For further explanation, please refer to Figures 5-7 The braking assembly 228 includes: a steel sheet 228-3 with splines evenly distributed in the outer ring along the circumferential direction and a buffer sheet 228-1, and a friction sheet 228-2 with splines evenly distributed in the inner ring along the circumferential direction.

[0045] like Figure 8 As shown, the braking assembly 228 is arranged with alternating friction plates 228-2 and steel plates 228-3 in the middle, and two sets of buffer plates 228-1 are provided at both ends; wherein, the friction plates 228-2 and the drive disc 225 are splinedly engaged, and the buffer plates 228-1 and the steel plates 228-3 are splinedly engaged with the brake housing 202.

[0046] In this embodiment: alternating grooves are provided on both sides of the friction plate 228-2. These grooves improve heat dissipation of the friction plate 228-2, reduce braking distance, and enhance braking reliability; and / or The contact surfaces of the buffer plate 228-1 with the large end cap 232 and the brake pressure plate 222 are provided with wear-resistant thick pads made of composite materials. When the brake assembly 228 is pressed, it can provide buffering between the buffer plate 228-1 and the large end cap 232, as well as between the buffer plate 228-1 and the friction plate pressure plate 222, thereby reducing wear and noise.

[0047] please Figures 9-11 As shown, several driving piston assemblies 212 are distributed around the brake housing 202 and are used to press the brake assembly 228 for braking during driving; several parking piston assemblies 213 are distributed around the brake housing 202 and are normally closed to press the brake assembly 228 for braking when parking.

[0048] As a further explanation, such as Figure 10 As shown, the travel piston assembly 212 includes: The traveling piston 212-2 is installed in the groove of the brake housing 202; the traveling piston 212-2 is fixed to the brake pressure plate 222 by the traveling bolt 212-1; the traveling piston 212-2 has a guide sleeve 212-3 installed inside; the outer ring of the guide sleeve 212-3 is coaxially mounted with the traveling spring 212-4 and the traveling baffle 212-6, and the two ends of the traveling spring 212-4 are axially limited by the guide sleeve 212-3 and the traveling baffle 212-6 respectively; the traveling baffle 212-6 is axially limited by the traveling snap ring 212-7; the inner ring of the guide sleeve 212-3 is interference-fitted with the traveling piston pin 212-5, and the other end of the traveling piston pin 212-5 is fixed to the brake housing 202; the brake housing 202 near the brake assembly 228 of the traveling piston 212-2 is provided with a sealing ring 218, a T-shaped seal 217 and a guide ring 219.

[0049] In this embodiment: the traveling piston assembly 212 has 8 sets distributed around its circumference. The traveling piston 212-1 is threaded through the brake pressure plate 222 and connected to the threaded hole at the center of the traveling piston 212-2 via the threaded portion of the traveling piston fixing bolt 212-1. The traveling piston retainer 212-7 has an outer diameter slightly larger than the traveling brake baffle 212-6 and an inner diameter slightly smaller than the traveling brake baffle 212-6, thus axially limiting the traveling brake baffle 212-6. The traveling piston 212-2 has an annular groove, and the traveling piston retainer 212-7 is installed in this annular groove. The traveling piston pin 212-5 is threadedly connected to the brake housing 202. The sealing ring 218, T-seal 217, and guide ring 219 are installed in the annular groove of the brake housing 202.

[0050] The connection relationships and limitations described above are not limited to this method. Any selection and setting made by those skilled in the art based on actual working conditions are within the scope of protection of this invention.

[0051] As a further explanation, such as Figure 12 As shown, the parking piston assembly 213 includes: The parking piston 213-7 is installed in the groove of the brake housing 202; the parking piston 213-7 is coaxially provided with a parking threaded sleeve 213-3 on the side near the brake pressure plate 222, and a parking expansion sleeve 213-5 is fitted between the parking threaded sleeve 213-3 and the parking piston 213-7.

[0052] In this embodiment: the parking expansion sleeve 213-5 and the parking piston 213-7 are slidably connected by an inclined plane, and the parking expansion sleeve 213-5 and the parking threaded sleeve 213-3 are connected by threads. The parking expansion sleeve 213-5 is provided with a male thread, and the parking threaded sleeve 213-3 is provided with a female thread on its outer ring. The cross-sectional shape of both the male thread and the female thread is a right trapezoid.

[0053] The parking expansion sleeve 213-5 is axially limited on one side by the parking retaining ring 213-4 installed in the inner groove of one end of the parking piston 213-7, and the other side of the parking expansion sleeve 213-5 is axially limited by the parking positioning pin 213-6; the parking threaded sleeve 213-3 is fixed to the brake pressure plate 222 through the parking fixing bolt 213-1.

[0054] In this embodiment, the connection between the parking bolt 213-1 and the brake pressure plate 222 is a threaded connection. A parking spring 213-2 is also fitted on the parking bolt 213-1, with one end abutting against the bolt head of the parking bolt 213-1 and the other end abutting against the parking threaded sleeve 213-3 to form an axial limit.

[0055] The other side of the parking piston 213-7 is connected to one side of the parking end cover 213-9, with an axial gap between them; the annular space formed by the parking piston 213-7 and the parking end cover 213-9 is provided with several stacked parking disc springs 213-8.

[0056] In one embodiment, four sets of parking piston assemblies 213 are arranged around the circumference. By adjusting the initial compression of the parking disc spring 213-8, the parking piston 213-7 can be normally closed for parking. The other side of the parking end cover 213-9 is provided with an internal hexagonal screw hole. Correspondingly, a through hole is provided at the same axial position on the cover plate 201, and an oil plug 233 is installed at the through hole. Since the parking end cover 213-9 and the brake housing 202 are connected by threads, when the parking piston 213-7 is locked due to hydraulic oil leakage and cannot be released by pushing the parking piston 213-7 to release the parking brake, the parking end cover 213-9 can be rotated through the internal hexagonal screw hole to release the parking disc spring 213-8, allowing the parking piston 213-7 to return to its original position and release the parking brake. In addition, the outer ring of the parking piston 213-7 cooperates with the parking small seal ring 220 and parking large seal ring 221 installed in the groove on the brake housing 202 to ensure the sealing of the hydraulic oil in the hydraulic oil chamber 33 of the parking piston and improve the reliability of the brake.

[0057] It should be noted that: the parking end cover 213-9 has an internal hexagonal screw hole on one side, which includes, but is not limited to, an internal hexagonal screw hole. Other structures of the parking end cover that can be rotated with tools, such as internal quadrilateral holes, polygonal holes, etc., are all within the protection scope of this invention.

[0058] As further explained, the oil circuits of the aforementioned driving piston assembly 212 and parking piston assembly 213 are as follows: The brake housing 202 and the cover plate 201 are respectively provided with annular grooves; the brake housing 202 and the cover plate 201 are combined to close the two annular grooves to form the driving hydraulic oil passage 27 and the parking hydraulic oil passage 29 respectively.

[0059] The annular groove of the brake housing 202 is fitted with a large O-ring 214 for the driving hydraulic passage and a middle O-ring 215 for the driving hydraulic passage, from the outer ring to the inner ring, to prevent oil leakage from the driving hydraulic passage 27. The groove of the cover plate 201 is fitted with an O-ring 216 for the parking hydraulic passage, to prevent oil leakage from the parking hydraulic passage 29.

[0060] In this embodiment, the sealing grooves on both sides of the driving and parking hydraulic oil passages are equipped with sealing rings, which can improve the sealing performance of the brake hydraulic oil.

[0061] The travel hydraulic oil passage 27 is connected to the travel piston assembly 212 and the brake housing 202 through the travel exhaust branch passage 35 to form a closed travel piston hydraulic oil chamber 32; the travel hydraulic oil passage 27 is also connected to one of the travel exhaust main passages 28, and the other two passages of the travel exhaust main passage 28 are the inlet and outlet of the travel hydraulic oil, respectively.

[0062] like Figure 13 As shown, the parking hydraulic oil passage 29 is connected to the parking piston assembly 213, the brake housing 202 and the brake pressure plate 222 through the parking exhaust branch passage 34 to form a closed parking piston hydraulic oil chamber 33; the parking hydraulic oil passage 29 is also connected to one of the parking exhaust main passages 30, and the other two passages of the parking exhaust main passages 30 are the oil inlet and oil return port of the parking hydraulic oil.

[0063] It should be noted that: oil plugs 233 are installed on the oil inlet and outlet of the main exhaust channel 28 to block the connection between the main exhaust channel 28 and the outside world, forming a closed exhaust oil channel for the vehicle; a small oil plug 239 is installed at the lower end of the parking exhaust branch channel 34 to block the connection between the parking exhaust branch channel 34 and the outside world, forming a closed parking hydraulic oil channel.

[0064] As a further improvement: such as Figure 14 and 15 As shown, the brake housing 202 has an inner cooling oil passage 22 and an outer cooling oil passage 25. A cover plate 201 is installed on one side of the brake housing 202 located on the cooling oil passage. The cover plate 201 has an inner cooling oil passage outlet 21 corresponding to the inner cooling oil passage 22 and an outer cooling oil passage inlet 24 corresponding to the outer cooling oil passage 25. Multiple sets of inner cooling oil passage inlets 23 are formed on the annular surface of the drive disc 225, which are distributed circumferentially and penetrate the inner and outer annular surfaces.

[0065] The cooling principle is as follows: Cooling oil enters the outer cooling oil passage 25 through the outer cooling oil passage inlet 24, and flows to the cooling oil chamber through the outer cooling oil passage outlet 26. As the drive disc 225 rotates, the cooling oil is thrown from the inner cooling oil passage inlet 23 into the inner cooling oil passage 22 to forcibly cool the area of ​​the brake assembly 228. The cooled oil after heat exchange is discharged from the inner cooling oil passage outlet 21. The design of inner and outer cooling oil passages increases the contact area between the cooling oil and the brake assembly 228 and connecting parts, improving the heat dissipation efficiency and braking reliability of the brake.

[0066] It should be noted that: before the cooling oil flows to the cooling oil chamber, it flows through the spline at the connection between the brake housing 202 and the frame 1, lubricates and cools the connection, and flows to the cooling oil chamber through the installation gap between the baffle 223 and the boss of the frame 1. The cooling oil chamber is a rotating body surrounded by the drive disc 225, the bearing spacer 230, the baffle 223 and the brake housing 202.

[0067] The baffle 223 is fixed to the brake housing 202 by hexagon socket head cap screws 224, and a friction plate pressure plate 222 is fitted on its outer ring. The baffle 223 can radially position the friction plate pressure plate 222.

[0068] In this embodiment: as follows Figure 16 As shown, cover plate 201 is fixed to brake housing 202 by cover plate bolt 1 208 and cover plate bolt 209. Cooling oil cover plate 203 is installed on inner cooling oil passage outlet 21 and outer cooling oil passage inlet 24; cooling oil cover plate 203 is fixed to cover plate 201 by cover plate bolt 238.

[0069] Based on the technical solutions of the above embodiments, the present invention provides specific implementation methods: The brake has two operating states: service brake and parking brake. Since the parking piston assembly 213 is normally closed, meaning the brake assembly 228 is in a compressed state by adjusting the initial compression of the parking disc spring 213-8, the vehicle is in parking brake mode by default. Therefore, the parking brake must be released before driving the vehicle. When the parking brake release command is issued, hydraulic oil flows from the parking exhaust manifold 30 through the parking hydraulic oil passage 29 and the parking exhaust branch passage 34 into the parking piston hydraulic oil chamber 33. Under the thrust of the hydraulic oil, the parking piston 213-7 moves away from the brake assembly 228, simultaneously compressing the parking spring 213-2 and the parking disc spring 213-8. The brake assembly 228 is no longer pressed, thus releasing the parking brake. When the parking brake command is issued, the hydraulic oil in the parking piston hydraulic oil chamber 33 is discharged from the parking exhaust manifold 30. Under the return force of the parking disc spring 213-8 and the parking spring 213-2, the parking piston 213-7 pushes the brake pressure plate 222 towards the brake assembly 228 and presses the brake assembly 228, achieving parking brake. After the parking brake is released, the vehicle is in a driving state, at which point the service brake needs to be applied. When a service brake command is issued, hydraulic oil flows from the service exhaust main channel 28 through the service hydraulic oil channel 27 and the service exhaust branch channel 35 into the service piston hydraulic oil chamber 32. Under the thrust of the high-pressure hydraulic oil, the service baffle 212-6 pushes the service spring 212-4, which in turn pushes the service piston 212-2, carrying the brake pressure plate 222, towards the brake assembly 228, thus pressing the brake assembly 228 and achieving service braking. When a service brake release command is issued, the hydraulic oil in the service piston hydraulic oil chamber 32 is discharged from the service exhaust main channel 28. Under the return force of the service spring 212-4, the service piston 212-2 moves away from the brake assembly 228, releasing the brake assembly 228 and thus releasing the service brake. It is worth noting that the service brake and parking brake can be applied simultaneously. In an emergency, when applying the service brake, the parking brake can be used as an auxiliary brake to shorten the braking distance and ensure driving safety.

[0070] Example 2

[0071] A driving-parking integrated connection structure includes: a multi-piston driving-parking integrated wet brake 2, a frame 1, and a wheel hub 3 as described in Embodiment 1; the frame 1 is connected to and fitted with the multi-piston driving-parking integrated wet brake 2 via a spline, and is axially positioned by a boss at the spline of the frame 1; the wheel hub 3 is rotatably connected to the frame 1 and the multi-piston driving-parking integrated wet brake 2.

[0072] As further explanation: Please see Figure 1 and Figure 2 Several limiting baffles 204 are provided at the connection between the end face of the multi-piston traveling and parking integrated wet brake and the boss of the frame 1.

[0073] like Figure 17 and Figure 18 As shown, the hub 3 and drive disc 225 are connected by a spline drive. The outer ring of the connection between the drive disc 225 and the hub 3 has an annular groove. An O-ring 227 and a rectangular ring 226 of the drive disc are fitted into the annular groove from the inner ring to the outer ring, providing a double seal and effectively preventing lubricating oil leakage from the hub 3 and drive disc 225. A sealing groove 9 is provided at the connection between the hub 3 and the large end cover 232, and a large floating oil seal 229 is installed there. A sealing groove 9 is provided at the connection between the inner ring of the drive disc 225 and the bearing spacer 230, and a small floating oil seal 240 is installed between the drive disc 225 and the bearing spacer 230. The bearing spacer 230 is fitted onto the outer ring of the frame 1 and axially limited by a boss on the outer ring of the frame 1.

[0074] It should be noted that the inner ring of the bearing spacer 230 is also provided with an annular groove, in which the bearing spacer O-ring 231 is installed; when the bearing spacer 230 is fitted on the frame 1, the bearing spacer O-ring 231 can play the role of sealing the lubricating oil.

[0075] In this embodiment, the limiting baffle 204 is fixed to the brake housing 202 by the limiting baffle bolt 210. A pad 206 is provided between the limiting baffle 204 and the brake housing 202. The pad 206 has a recess corresponding to the installation position of the limiting baffle 204. A rubber pad 205 is installed in the recess to buffer and isolate vibration.

[0076] Example 3

[0077] Please see Figure 19 A rear axle includes: a frame 1, a hub 3, a rim 4, a tire 5, a motor 6, and a rear axle housing 7; the frame 1 is connected to the rear axle housing 7; the motor 6 is installed inside the rear axle housing 7 as a power source for driving; the hub 3 is axially limited on the frame 1 by a bearing 8; the rim 4 is installed on the hub 3; and the tire 5 is installed on the rim 4.

[0078] The rear axle also has the multi-piston integrated wet brake 2 of embodiment one installed through the integrated driving and parking connection structure of embodiment two.

[0079] Example 4

[0080] An electric drive mining dump truck is provided, wherein the electric drive mining dump truck is equipped with the rear axle of Embodiment 3.

[0081] Compared with the prior art, the present invention has the following significant advantages: The brake system adopts a multi-piston integrated design for both driving and parking, improving the integration of the brake structure, reducing the number of structural components, complexity, and space occupancy, and solving the problems of complex structure and inconvenient installation of traditional split wet brakes. The left and right sides of the brake housing are connected to the wheel hub and frame respectively via spline connections, shortening the axial length of the brake, reducing space occupation, and improving ease of assembly and disassembly. A limit baffle and rubber gasket on the right side of the brake housing reduce the impact and wear caused by movement in the spline connection, improving transmission smoothness. Simultaneously, the spline connection avoids oil leakage caused by broken connecting bolts in traditional brakes, thus improving the brake's sealing performance. Sealing rings and floating oil seals are used at component connections to improve the sealing performance of brake cooling oil and hydraulic oil, ensuring reliable sealing. Floating oil seals are installed at the connection between the large end cap and the wheel hub, and at the connection between the drive disc and the bearing spacer. O-rings are installed on both sides of the oil passages, effectively reducing the risk of leakage of cooling oil and brake hydraulic oil. In addition, the integrated design of the driving and parking brakes means that the brakes are not installed on the high-speed end of the motor, which can effectively avoid the braking failure problem caused by the high-speed braking of the parking brake in traditional split brakes and improve braking reliability.

[0082] By employing multiple circumferentially distributed traveling pistons and multiple circumferentially distributed parking pistons instead of the traditional single-piston design, the uniformity of piston thrust distribution on the friction plate is improved, thereby reducing wear and extending the service life of the friction plates. Furthermore, both the traveling and parking pistons utilize a small-sized piston design, which, compared to traditional large-sized piston wet brakes, reduces manufacturing costs and simplifies assembly and maintenance.

[0083] The parking end cover has an internal hexagonal screw hole on one side and a through hole at the corresponding axial position of the cover plate. This can effectively solve the problem of the brake locking due to leakage of hydraulic oil from the parking piston and the inability to release the parking brake, thereby reducing the risk of parking brake failure, enhancing the safety redundancy of the parking brake, and improving the operational reliability of the electric drive mining dump truck.

[0084] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A multi-piston integrated wet brake, characterized in that, include: Brake housing (202); A drive disc (225) is combined with the brake housing (202) to form a brake cavity; Braking assembly (228), which is installed in the brake housing (202) and the drive disc (225) to form a braking cavity, and cuts off the rotational power of the drive disc (225) when the braking assembly (228) is pressed. A traveling piston assembly (212) is provided, which is distributed around the brake housing (202) in several parts, and is used to press the brake assembly (228) for braking during driving. Parking piston assembly (213), wherein several parking piston assemblies (213) are distributed around the brake housing (202), and normally close and press the brake assembly (228) for braking when parking.

2. The multi-piston integrated wet brake according to claim 1, characterized in that: The brake housing (202) is provided with an inner cooling oil passage (22) and an outer cooling oil passage (25). The brake housing (202) is fitted with a cover plate (201) on one side of the cooling oil passage. The cover plate (201) is provided with an inner cooling oil passage outlet (21) corresponding to the inner cooling oil passage (22) and an outer cooling oil passage inlet (24) corresponding to the outer cooling oil passage (25). The drive disk (225) has multiple sets of internal cooling oil passage inlets (23) that are distributed circumferentially and penetrate the inner and outer ring surfaces. Cooling oil enters the outer cooling oil passage (25) through the outer cooling oil passage inlet (24), flows to the cooling oil chamber through the outer cooling oil passage outlet (26), and the cooling oil is thrown into the inner cooling oil passage (22) from the inner cooling oil passage inlet (23) as the drive disc (225) rotates to force cooling of the brake assembly (228) area. The cooled oil after heat exchange is discharged from the inner cooling oil passage outlet (21).

3. The multi-piston integrated wet brake according to claim 2, characterized in that: Cooling oil cover plates (203) are installed on the inner cooling oil passage outlet (21) and the outer cooling oil passage inlet (24); The cooling oil cover plate (203) is fixed to the cover plate (201) by cover plate bolts (238).

4. The multi-piston integrated wet brake according to any one of claims 1-3, characterized in that: The braking assembly (228) is also provided with a large end cap (232) and a braking pressure plate (222) on both sides respectively. The brake assembly (228) is pressed against the brake plate (222) by the extension of the driving piston assembly (212) and / or the parking piston assembly (213).

5. The multi-piston integrated wet brake according to claim 4, characterized in that: The travel piston assembly (212) includes: The traveling piston (212-2) is installed in the groove of the brake housing (202). The traveling piston (212-2) is fixed to the brake pressure plate (222) by a traveling fixing bolt (212-1); The travel piston (212-2) is equipped with a guide sleeve (212-3). The outer ring of the guide sleeve (212-3) is coaxially mounted with the travel spring (212-4) and the travel baffle (212-6), and the two ends of the travel spring (212-4) are axially limited by the guide sleeve (212-3) and the travel baffle (212-6), respectively. The traveling baffle (212-6) is axially limited by the traveling snap ring (212-7); The inner ring of the guide sleeve (212-3) is interference-fitted with the travel piston pin (212-5), and the other end of the travel piston pin (212-5) is fixed to the brake housing (202). The driving piston (212-2) is provided with a sealing ring (218), a T-shaped seal (217) and a guide ring (219) on the brake housing (202) on the side of the brake assembly (228) near the brake assembly.

6. The multi-piston integrated wet brake according to claim 4, characterized in that: The parking piston assembly (213) includes: The parking piston (213-7) is installed in the groove of the brake housing (202). The parking piston (213-7) is coaxially provided with a parking threaded sleeve (213-3) on the side near the brake pressure plate (222), and a parking expansion sleeve (213-5) is fitted between the parking threaded sleeve (213-3) and the parking piston (213-7). The parking expansion sleeve (213-5) is axially limited on one side by a parking retaining ring (213-4) installed in the inner groove of one end of the parking piston (213-7), and the parking expansion sleeve (213-5) is axially limited on the other side by a parking positioning pin (213-6). The parking threaded sleeve (213-3) is fixed to the brake pressure plate (222) through the parking fixing bolt (213-1); The other side of the parking piston (213-7) is connected to one side of the parking end cap (213-9), with an axial gap between them; The annular space formed by the parking piston (213-7) and the parking end cap (213-9) is provided with several stacked parking disc springs (213-8).

7. The multi-piston integrated wet brake according to claim 6, characterized in that: The parking expansion sleeve (213-5) and the parking piston (213-7) are slidably connected via an inclined surface, and the parking expansion sleeve (213-5) and the parking threaded sleeve (213-3) are connected via threads; and / or The parking expansion sleeve (213-5) has a male thread inside, and the parking threaded sleeve (213-3) has a female thread on its outer ring. Both the male and female threads have right-angled trapezoidal cross-sectional shapes; and / or The parking bolt (213-1) is also fitted with a parking spring (213-2), one end of which abuts against the bolt head of the parking bolt (213-1), and the other end abuts against the parking threaded sleeve (213-3) to form an axial limit.

8. The multi-piston integrated wet brake according to any one of claims 5-7, characterized in that: A cover plate (201) is installed on one side of the brake housing (202); The brake housing (202) and the cover plate (201) are respectively provided with annular grooves; The brake housing (202) and the cover plate (201) are combined to close two annular grooves to form a driving hydraulic oil passage (27) and a parking hydraulic oil passage (29), respectively. The driving hydraulic oil passage (27) is connected to the driving piston assembly (212) and the brake housing (202) through the driving exhaust branch (35) to form a closed driving piston hydraulic oil chamber (32). The hydraulic oil passage (27) is also connected to one of the main exhaust passages (28) of the vehicle, and the other two passages of the main exhaust passages (28) of the vehicle are the inlet and outlet of the hydraulic oil of the vehicle. The parking hydraulic oil passage (29) is connected to the parking piston assembly (213), the brake housing (202) and the brake pressure plate (222) through the parking exhaust branch (34) to form a closed parking piston hydraulic oil chamber (33). The parking hydraulic oil passage (29) is also connected to one of the parking exhaust main passages (30), and the other two passages of the parking exhaust main passages (30) are the oil inlet and oil return port of the parking hydraulic oil.

9. The multi-piston integrated wet brake according to claim 8, characterized in that: The braking assembly (228) includes: a steel sheet (228-3) and a buffer sheet (228-1) with splines evenly distributed on the outer ring along the circumferential direction, and a friction sheet (228-2) with splines evenly distributed on the inner ring along the circumferential direction. The braking assembly (228) is provided with alternating friction plates (228-2) and steel plates (228-3) in the middle, and two sets of buffer plates (228-1) at both ends. The friction plate (228-2) and the drive disc (225) are splinedly engaged, and the buffer plate (228-1) and the steel plate (228-3) are splinedly engaged with the brake housing (202).

10. The multi-piston integrated wet brake according to claim 1, characterized in that: The friction plate (228-2) has alternating grooves on both sides; and / or The contact surfaces of the buffer plate (228-1) with the large end cap (232) and the brake pressure plate (222) are provided with wear-resistant thick pads made of composite materials.

11. A type of integrated connection structure for both driving and parking, characterized in that, include: The multi-piston integrated wet brake according to any one of claims 1-10 (2); The frame (1) is connected and fitted with the multi-piston travel-parking integrated wet brake (2) via a spline. The hub (3) is rotatably connected to the frame (1) and the multi-piston travel-and-hold integrated wet brake (2).

12. The integrated connection structure for driving and parking according to claim 11, characterized in that: The outer ring of the frame (1) is fitted with the bearing spacer (230); The hub (3) is spline-driven with the drive disc (225); A sealing groove (9) is provided at the connection between the hub (3) and the large end cap (232), and a large floating oil seal (229) is installed there. A sealing groove (9) is provided at the connection between the inner ring of the drive disc (225) and the bearing spacer (230), and a small floating oil seal (240) is installed between the drive disc (225) and the bearing spacer (230).

13. The integrated connection structure for parking and pausing according to claim 11 or 12, characterized in that: Several limiting baffles (204) are provided at the connection between the end face of the multi-piston travel-parking integrated wet brake (2) and the boss of the frame (1).

14. The integrated connection structure for driving and parking as described in claim 13, characterized in that: The limiting baffle (204) is fixed to the brake housing (202) by the limiting baffle bolt (210); A pad (206) is provided between the limiting baffle (204) and the brake housing (202). The pad (206) has a recess corresponding to the installation position of the limiting baffle (204), and a rubber pad (205) is installed in the recess.

15. A rear axle, characterized in that, include: Rack (1); Rear axle housing (7), on which the frame (1) is connected; The motor (6) is installed in the rear axle housing (7) and is used as a power source for driving. The hub (3) is axially positioned on the frame (1) by a bearing (8); A rim (4) is mounted on the hub (3); Tire (5), said tire (5) is mounted on said rim (4); The rear axle also has a multi-piston integrated wet brake (2) as described in claims 1-10 installed via the integrated driving and parking connection structure described in claims 11-14.

16. An electric drive mining dump truck, characterized in that: The electric-drive mining dump truck is equipped with the rear axle as described in claim 15.

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