Large-tonnage off-highway wide-body vehicle main reducer

Abstract

A main reducer for large-tonnage off-highway wide-body vehicles includes a transmission system, a braking system, and a lubrication and cooling system. The transmission system is the main reducer transmission system, including a multi-stage gear reduction mechanism and a double differential transmission mechanism. The braking system is located at the input end of the main reducer, and its power output end is connected to the input end of the transmission mechanism to transmit braking torque to the transmission mechanism and then to the wheels. The lubrication and cooling system is a closed-loop lubrication and cooling system, which is interconnected with the transmission system and the braking system to form a closed-loop oil circuit. This invention, by highly integrating the hydraulically controlled multi-plate friction braking mechanism with the main reducer transmission system and designing a closed-loop gear oil circulation lubrication and cooling structure, effectively solves the problems of significant brake fade and insufficient auxiliary braking cooling capacity of large-tonnage off-highway wide-body vehicles under continuous heavy-load downhill conditions.

Description

Technical Field

[0001] This invention relates to the field of engineering machinery technology, specifically a main reducer for large-tonnage off-highway wide-body vehicles. Background Technology

[0002] Wide-body off-highway vehicles are core transportation equipment in heavy engineering scenarios such as open-pit mines and earthmoving. They are generally characterized by large load capacity, harsh working conditions, continuous long downhill driving, high braking frequency, and high braking intensity. In actual operation, vehicles need to rely on continuous and stable braking capacity to control speed to ensure driving safety and transportation efficiency. The mainstream braking system in the industry usually adopts a multi-stage combined braking scheme: drum brakes or disc brakes are used as the main braking system for regular braking and parking; electric eddy current retarders, hydraulic retarders, or on-board electric braking systems are used as auxiliary braking systems for speed stabilization and load sharing under continuous downhill conditions.

[0003] However, under extreme operating conditions of heavy tonnage, heavy loads, and long downhill slopes, existing braking solutions have significant shortcomings. First, drum / disc brakes exhibit severe heat fade during continuous braking, failing to meet high-intensity braking demands stably and effectively over a long period, easily leading to safety hazards such as brake failure, tire overheating, and brake component burnout. Second, electric braking and retarder devices, limited by their own heat dissipation capacity and structural layout, suffer from insufficient heat dissipation under continuous high-load braking conditions, resulting in rapid heat accumulation and easily triggering overheat protection, leading to torque limitation or discontinuation. Their poor adaptability makes them unsuitable for the braking requirements of heavy-duty off-highway wide-body vehicles during continuous downhill heavy loads.

[0004] Therefore, existing main reducers and braking systems can no longer meet the requirements of large-tonnage off-highway wide-body vehicles for high braking reliability, high thermal stability, and high structural integration under heavy-load, harsh, and continuous operating conditions. There is an urgent need for a main reducer structure that integrates braking functions and possesses efficient self-lubrication and self-heating capabilities to solve technical problems such as continuous braking heat fade, insufficient braking capacity, poor heat dissipation, and non-compact structure. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a main reducer for large-tonnage off-highway wide-body vehicles, which achieves reliable braking, sufficient heat dissipation, and high integration, and is suitable for long-term continuous braking of large-tonnage off-highway wide-body vehicles.

[0006] The present invention is achieved by the following technical solution: a main reducer for large-tonnage off-highway wide-body vehicles, comprising a transmission system, a braking system and a lubrication and heat dissipation system; The transmission system is a main reducer transmission system, including a multi-stage gear reduction mechanism and a double differential transmission mechanism. Power is output to the wheel end through the multi-stage gear reduction mechanism and the double differential transmission mechanism to realize the functions of speed reduction and torque increase and inter-axle and inter-wheel differential. The braking system is located at the input end of the main reducer, and the power output end of the braking system is connected to the input end of the transmission mechanism to transmit the braking torque to the transmission mechanism and then to the wheel end. The lubrication and heat dissipation system is a closed-loop lubrication and heat dissipation system. The closed-loop lubrication and heat dissipation system, transmission system, and braking system are connected to form a closed-loop oil circuit, which is used to continuously lubricate and dissipate heat from the braking system.

[0007] Furthermore, the transmission system is composed of an input shaft, an inter-shaft differential, a pair of driving and driven cylindrical gears, a pair of driving and driven bevel gears, and an inter-wheel differential connected in series.

[0008] The braking system is a hydraulically controlled multi-plate friction braking mechanism, which is integrated into the input end of the main reducer.

[0009] The braking system includes a transmission flange, an end cover, a bridge box cover, a brake piston, a static friction pad, a dynamic friction disc, and an elastic reset component. The bridge box cover and the brake piston form a sealed pressure chamber through a sealing ring. The sealed pressure chamber is the control pressure oil chamber for the brake piston. The brake piston is used to press the static friction pad and the dynamic friction disc to generate braking torque. The braking torque is output to the transmission mechanism via the transmission flange.

[0010] The bridge box cover is provided with an oil inlet that communicates with the sealed oil chamber.

[0011] The inner side of the transmission flange is splinedly connected to the input shaft, and the outer side of the transmission flange is splinedly connected to the dynamic friction disc; the inner side of the end cover is splinedly connected to the static friction plate, and the static friction plate and the dynamic friction disc are arranged alternately.

[0012] It also includes a clearance adjusting nut, which is threadedly connected to the bridge box cover and is used to adjust the bearing preload and the installation position of the elastic reset component.

[0013] The lubrication and heat dissipation system includes an axle housing cavity, a main reducer front cavity, a brake cavity, a housing oil passage, and a bearing pump suction circuit. The axle housing cavity is connected to the inter-shaft differential through the housing oil passage. The main reducer front cavity is connected to the brake cavity of the braking system through the housing oil passage. The brake cavity returns to the main reducer front cavity through the bearing pump suction circuit, forming a closed loop.

[0014] The housing oil passages include the axle housing cover oil passage, the housing reduction oil passage I, and the housing reduction oil passage II. The housing reduction oil passage I connects the axle housing cavity and the front cavity of the main reducer. The axle housing cover oil passage and the housing reduction oil passage I are connected to each other to connect the front cavity of the main reducer and the brake cavity.

[0015] The bearing pumping circuit includes a tapered roller bearing, which is installed between the input shaft and the housing. The braking chamber and the front chamber of the main reducer are connected through an internal oil passage in the bearing.

[0016] The present invention has the following advantages: 1. The braking mechanism is integrated into the input end of the main reducer, resulting in a compact structure, small footprint, short transmission chain, and direct and efficient braking response.

[0017] 2. It adopts a closed-loop lubrication and heat dissipation system, which relies on the movement of gears and bearings to achieve automatic oil supply and heat dissipation, meet the requirements of continuous downhill braking conditions, and significantly reduce heat fade.

[0018] 3. Hydraulically controlled braking torque, smooth and adjustable braking, suitable for heavy-duty operations of large-tonnage off-highway wide-body vehicles.

[0019] 4. The overall structure has high reliability, extending the service life of the braking system and transmission system. Attached Figure Description

[0020] 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.

[0021] In the attached diagram: Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the braking cavity of the present invention; Figure 3 This is a schematic diagram of the structure of the oil passage in the casing of the present invention; Figure 4 This is a schematic diagram of the adjusting nut of the present invention; Figure 5 This is a schematic diagram of the end cap structure of the present invention; Figure 6 This is a schematic diagram of the transmission flange of the present invention; Figure 7 This is a schematic diagram of the dynamic friction disc of the present invention; Figure 8 This is a schematic diagram of the static friction pad of the present invention.

[0022] In the diagram: 1. Transmission flange, 2. Input shaft, 3. End cover, 4. Static friction plate, 5. Dynamic friction disc, 6. Brake piston, 7. Sealing ring, 8. Return spring, 9. Bolt, 10. Adjusting nut, 11. Transition box cover, 12. Reducer housing, 13. Driving cylindrical gear, 14. Driven cylindrical gear, 15. Inter-shaft differential, 16. Driving bevel gear, 18. Driven bevel gear, 19. Inter-wheel differential, 20. Sealing oil chamber, 21. Transition box cavity, 22. Main reducer front cavity, 23. Tapered roller bearing, 24. Reducer housing oil passage I, 25. Reducer housing oil passage II, 26. Transition box cover oil passage, 27. Brake chamber.

[0023] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0025] In the description of this invention, it should be noted that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] like Figures 1 to 8 The invention discloses a large-tonnage off-highway wide-body vehicle main reducer, which includes a transmission system, a braking system, and a lubrication and heat dissipation system. The invention integrates the three main parts, deeply integrates the braking function with the main reducer transmission chain, and achieves continuous lubrication and forced heat dissipation of the brake chamber through a closed-loop oil circuit. It is particularly suitable for heavy-load, long downhill, and high-intensity continuous operation conditions.

[0028] like Figure 1The diagram illustrates a main reducer for a large-tonnage off-highway wide-body vehicle. The transmission system is a main reducer transmission system comprising a multi-stage gear reduction mechanism and a dual differential transmission mechanism. Power is output to the wheel ends through these mechanisms, achieving speed reduction and torque increase, as well as inter-axle and inter-wheel differential functions. The transmission system is constructed by sequentially connecting an input shaft 2, an inter-axle differential 15, a main and driven cylindrical gear pair, a main and driven bevel gear pair, and an inter-wheel differential 18. The transmission system of this invention serves as the core of the vehicle's power transmission. It is composed of an input shaft, an inter-axle differential, a driving cylindrical gear 13, a driven cylindrical gear 14, a driving bevel gear 16, a driven bevel gear 17, and an inter-wheel differential 18, which are sequentially connected for transmission. After power is input through the input shaft, it first enters the inter-axle differential to achieve power distribution between the axles. Then, power is transmitted through the driving and driven cylindrical gears. Subsequently, power is reduced and torque increased in two stages through the driving and driven bevel gears. Finally, power is distributed to the left and right half-axles and wheels through the inter-wheel differential, enabling the vehicle to drive normally. Under braking conditions, the braking torque is transmitted in the reverse direction along this transmission chain, causing the wheels to decelerate smoothly. The braking response is direct, and the transmission efficiency is high.

[0029] like Figures 1 to 2 The invention discloses a main reducer for large-tonnage off-highway wide-body vehicles. The braking system is located at the input end of the main reducer, and its power output end is connected to the input end of the transmission mechanism to transmit braking torque to the wheels. The braking system is a hydraulically controlled multi-plate friction braking mechanism integrated into the input end of the main reducer. This invention's braking system employs a hydraulically controlled multi-plate friction braking structure, integrated into the input end of the main reducer, without occupying additional vehicle space. It features a compact structure, high integration, short transmission chain, and direct braking response.

[0030] like Figures 1 to 8The diagram illustrates a main reducer for a large-tonnage off-highway wide-body vehicle. The braking system includes a transmission flange 1, an end cover 3, a bridge housing cover 11, a brake piston 6, stationary friction pads 4, a dynamic friction disc 5, and an elastic reset component. The bridge housing cover 11 and the brake piston 6 form a sealed pressure chamber via a sealing ring. This sealed pressure chamber is the control pressure oil chamber for the brake piston 6. The brake piston 6 presses against the stationary friction pads 4 and the dynamic friction disc 5 to generate braking torque. This braking torque is output to the transmission mechanism via the transmission flange 1. The bridge housing cover 11 has an oil inlet communicating with the sealed oil chamber. The braking system of the present invention specifically includes a transmission flange, an end cover, a bridge box cover, a brake piston, a static friction pad, a dynamic friction disc, a sealing ring, and an elastic reset component. The elastic reset component is a return spring 8. The bridge box cover and the brake piston are sealed together by two sealing rings to form an independent and sealed oil chamber 19. An oil inlet communicating with the sealed oil chamber is provided on the bridge box cover for connecting external control oil pressure. The braking torque is proportional to the input oil pressure, and can achieve continuous, stable, and stepless adjustment to adapt to different downhill slopes and loads.

[0031] like Figures 1 to 2 , Figures 5 to 8 The invention discloses a high-tonnage off-highway wide-body vehicle main reducer. The inner side of the transmission flange 1 is splinedly connected to the input shaft 2, and the outer side of the transmission flange 1 is splinedly connected to the dynamic friction disc 5. The inner side of the end cover 3 is splinedly connected to the static friction plate 4, and the static friction plate 4 and the dynamic friction disc 5 are arranged alternately. In this invention, the inner circumference of the end cover is designed with splines for mating with the static plate; both the inner and outer circumferences of the transmission flange are designed with splines, with the inner spline connecting to the input shaft and the outer spline mating with the dynamic plate. This invention employs a multi-plate friction structure, resulting in a large friction area and heat dissipation area, enabling it to withstand high torque and high-frequency braking.

[0032] like Figure 1 , Figure 2 and Figure 4 The large-tonnage off-highway wide-body vehicle main reducer shown also includes a clearance adjusting nut 10, which is connected to the bridge housing cover 11 by bolts 9 and is used to adjust the bearing preload and the installation position of the elastic return element. To ensure the bearing operating accuracy and the reliability of the return spring installation, this embodiment also provides a clearance adjusting nut, which is bolted to the bridge housing cover. This not only adjusts the preload and clearance of the tapered roller bearing 22, but also provides stable installation support for the return spring, ensuring smooth and reliable reciprocating motion of the brake piston.

[0033] The braking system of the present invention operates as follows: During braking, pressurized oil enters the sealed oil chamber through the inlet, pushing the brake piston to the left against the return spring's force. The brake piston then presses against the alternating static friction plates and dynamic friction disc, generating frictional torque between the friction pairs. The inner side of the transmission flange is connected to the input shaft via a spline, and the outer side is connected to the dynamic friction disc via a spline. The inner side of the end cover is connected to the static friction plates via a spline, keeping the static friction plates relatively fixed. The generated frictional torque is transmitted to the input shaft via the transmission flange, and then sequentially through the inter-shaft differential, the driving and driven cylindrical gear pair, the driving and driven bevel gear pair, and the inter-wheel differential to the wheel ends, achieving vehicle deceleration and braking. By adjusting the input oil pressure, the clamping force of the friction pairs can be changed, achieving continuously adjustable braking torque to adapt to different loads and downhill conditions.

[0034] When the brake is released, the oil pressure in the sealed oil chamber is unloaded, the brake piston returns to its original position to the right under the elastic force of the return spring, the static friction plate separates from the dynamic friction disc, the friction torque disappears, and the brake is released.

[0035] Figures 1 to 3 The invention discloses a large-tonnage off-highway wide-body vehicle main reducer. The lubrication and cooling system is a closed-loop lubrication and cooling system, which is interconnected with the transmission system and braking system to form a closed-loop oil circuit for continuous lubrication and cooling of the braking system. This lubrication and cooling system is a closed-loop automatic circulation lubrication and cooling system driven by transmission components. It eliminates the need for an external oil pump, utilizing gear rotation and bearing pumping effect to achieve lubrication, cooling, and return of lubricating oil. This forms a self-circulating, highly heat-dissipating, and highly reliable built-in lubrication solution, specifically designed for harsh conditions requiring prolonged continuous braking.

[0036] like Figures 1 to 3 The diagram illustrates a main reducer for a large-tonnage off-highway wide-body vehicle. The lubrication and cooling system includes an axle housing cavity 20, a main reducer front cavity 21, a brake cavity 26, a housing oil passage, and a bearing pump suction circuit. The axle housing cavity is connected to the inter-axle differential via the housing oil passage. The main reducer front cavity is connected to the brake cavity of the braking system via the housing oil passage. The brake cavity returns to the main reducer front cavity via the bearing pump suction circuit, forming a closed loop. The lubrication system of this invention mainly consists of an axle housing cavity, a main reducer front cavity, a brake cavity, a housing oil passage, and a bearing pump suction circuit. Each cavity and oil passage is interconnected, forming a complete and closed circulating oil circuit.

[0037] like Figures 1 to 8The diagram illustrates a large-tonnage off-highway wide-body vehicle main reducer. The housing oil passages include an axle housing cover oil passage 25, a reducer housing oil passage I 23, and a reducer housing oil passage 24 II. The reducer housing oil passage 23 I connects the axle housing cavity and the front cavity of the main reducer. The axle housing cover oil passage 25 and the reducer housing oil passage I 23 are interconnected, connecting the front cavity of the main reducer and the brake cavity. The housing oil passages of this invention are the core delivery channels of the lubrication and heat dissipation system. They consist of a through-type oil passage pre-set inside the reducer housing 12 and the axle housing cover. This integrated oil circuit structure, without external pipelines, is specifically designed to directionally deliver lubricating oil from the transmission cavity to the brake cavity, achieving forced lubrication and efficient heat dissipation.

[0038] like Figures 1 to 3 The invention discloses a main reducer for a large-tonnage off-highway wide-body vehicle. The bearing pumping circuit includes a tapered roller bearing 22, which is installed between the input shaft and the housing. The braking chamber and the front chamber of the main reducer are connected through an internal oil passage in the bearing. The bearing pumping circuit of this invention mainly consists of a tapered roller bearing, a bearing mounting cavity, the front chamber of the main reducer, and a braking chamber. The tapered roller bearing is installed between the input shaft and the housing. The inner and outer rings of the bearing and the rollers form a gap flow channel with axial pumping capability. The braking chamber and the front chamber of the main reducer are connected through an internal oil passage in the bearing. During rotation, the oil film between the rollers and the raceway of the tapered roller bearing generates a directional axial pumping effect, achieving forced backflow in the braking chamber. This, together with the housing oil passage and gear oil slinging, forms a closed-loop circulation system.

[0039] The specific circulation path of the lubrication and heat dissipation system of the present invention is as follows: In the first path, the driven bevel gear rotates at high speed, throwing the gear oil in the axle housing cavity into the inter-shaft differential through the reducer oil passage I, lubricating the gears inside the inter-shaft differential. After the lubricating oil is saturated, it flows into the front cavity of the main reducer. In the second path, the lubricating oil in the front cavity of the main reducer enters the reducer housing oil passage II and the bridge box cover oil passage under the agitation of the driving cylindrical gear and driven cylindrical gear, and is directionally transported to the inside of the brake chamber to force lubricate and cool the dynamic friction disc, static friction pad, brake piston and bearing. The third path is that when the lubricating oil level in the brake chamber reaches the set height, the lubricating oil is drawn back to the front chamber of the main reducer under the pumping action of the tapered roller bearing, so as to achieve oil output balance in the brake chamber. The fourth path involves some of the lubricating oil in the front chamber of the main reducer flowing back to the bridge chamber via the tapered roller bearing at the position of the drive bevel gear, completing the overall closed-loop circulation.

[0040] Through the above four-way circulation, the lubricating oil can continuously carry away a large amount of heat generated by braking friction from the brake chamber, effectively avoiding excessive temperature in the brake chamber and thermal decay of the friction pair. This ensures that the braking system can maintain a stable braking torque under long-term continuous braking conditions, greatly improving the braking safety and operational continuity of off-highway wide-body vehicles under heavy-load long downhill conditions.

[0041] This invention discloses a main reducer for large-tonnage off-highway wide-body vehicles. By highly integrating the hydraulic multi-plate friction braking mechanism with the main reducer transmission system and designing a closed-loop gear oil circulation lubrication and heat dissipation structure, it effectively solves the problems of significant brake fade and insufficient auxiliary braking heat dissipation capacity of large-tonnage off-highway wide-body vehicles under continuous heavy-load downhill conditions. The braking response is direct, the braking torque is stable and adjustable, and the closed-loop circulation can continuously remove braking heat, meeting the needs of long-term continuous braking. At the same time, the overall structure is compact, highly integrated, occupies little space, and has a short transmission chain, significantly improving the braking safety, operational continuity, and overall reliability of the vehicle under harsh mining conditions.

[0042] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0043] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features found in other embodiments but not others, combinations of features from different embodiments are also within the scope of protection of this invention and form different embodiments. For example, in the embodiments described above, those skilled in the art can use them in combination based on known technical solutions and the technical problems to be solved by this application.

[0044] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A main reducer for large-tonnage off-highway wide-body vehicles, characterized in that: This includes the transmission system, braking system, and lubrication and cooling system; The transmission system is a main reducer transmission system, including a multi-stage gear reduction mechanism and a double differential transmission mechanism. Power is output to the wheel end through the multi-stage gear reduction mechanism and the double differential transmission mechanism to realize the functions of speed reduction and torque increase and inter-axle and inter-wheel differential. The braking system is located at the input end of the main reducer, and the power output end of the braking system is connected to the input end of the transmission mechanism to transmit the braking torque to the transmission mechanism and then to the wheel end. The lubrication and heat dissipation system is a closed-loop lubrication and heat dissipation system. The closed-loop lubrication and heat dissipation system, transmission system, and braking system are connected to form a closed-loop oil circuit, which is used to continuously lubricate and dissipate heat from the braking system.

2. The main reducer for large-tonnage off-highway wide-body vehicles as described in claim 1, characterized in that: The transmission system is composed of an input shaft (2), an inter-shaft differential (15), a main and driven cylindrical gear pair, a main and driven bevel gear pair, and an inter-wheel differential (18) connected in series.

3. The main reducer for large-tonnage off-highway wide-body vehicles as described in claim 1, characterized in that: The braking system is a hydraulically controlled multi-plate friction braking mechanism, which is integrated into the input end of the main reducer.

4. The main reducer for large-tonnage off-highway wide-body vehicles as described in claim 3, characterized in that: The braking system includes a transmission flange (1), an end cover (3), a bridge box cover (11), a brake piston (6), a static friction plate (4), a dynamic friction disc (5), and an elastic reset component. The bridge box cover (11) and the brake piston (6) form a sealed pressure chamber through a sealing ring. The sealed pressure chamber is the control pressure oil chamber of the brake piston (6). The brake piston (6) is used to press the static friction plate (4) and the dynamic friction disc (5) to generate braking torque. The braking torque is output to the transmission mechanism through the transmission flange (1).

5. The main reducer for large-tonnage off-highway wide-body vehicles as described in claim 4, characterized in that: The bridge box cover (11) is provided with an oil inlet that communicates with the sealing oil chamber.

6. The main reducer for large-tonnage off-highway wide-body vehicles as described in claim 4, characterized in that: The inner side of the transmission flange (1) is splinedly connected to the input shaft (2), and the outer side of the transmission flange (1) is splinedly connected to the dynamic friction disk (5); the inner side of the end cover (3) is splinedly connected to the static friction plate (4), and the static friction plate (4) and the dynamic friction disk (5) are arranged alternately.

7. The main reducer for large-tonnage off-highway wide-body vehicles as described in claim 4, characterized in that: It also includes a gap adjusting nut (10), which is threadedly connected to the bridge box cover (11) and is used to adjust the bearing preload and the installation position of the elastic reset component.

8. The main reducer for large-tonnage off-highway wide-body vehicles as described in claim 1, characterized in that: The lubrication and heat dissipation system includes an axle housing cavity (20), a main reducer front cavity (21), a brake cavity (26), a housing oil passage, and a bearing pump suction circuit. The axle housing cavity is connected to the inter-shaft differential through the housing oil passage. The main reducer front cavity is connected to the brake cavity (26) of the braking system through the housing oil passage. The brake cavity (26) returns to the main reducer front cavity through the bearing pump suction circuit, forming a closed loop.

9. The main reducer for large-tonnage off-highway wide-body vehicles as described in claim 1, characterized in that: The housing oil passages include the axle housing cover oil passage (25), the housing reduction oil passage I (23) and the housing reduction oil passage II (24). The housing reduction oil passage I (23) connects the axle housing cavity and the front cavity of the main reducer. The axle housing cover oil passage (25) and the housing reduction oil passage I (23) are connected to connect the front cavity of the main reducer and the brake cavity.

10. The main reducer for large-tonnage off-highway wide-body vehicles as described in claim 1, characterized in that: The bearing pumping circuit includes a tapered roller bearing, which is installed between the input shaft and the housing. The braking chamber and the front chamber of the main reducer are connected through an internal oil passage in the bearing.

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