Transmission rear end forced lubrication cooling system of parallel hydrodynamic retarder and transmission

Abstract

The invention belongs to the technical field of transmission cooling and lubricating, and relates to a transmission rear end forced lubricating and cooling system of a parallel hydrodynamic retarder and a transmission. Comprising a retarder support, a rear cover, an oil pump, a power takeoff side cover, a rear bearing cover, an oil pump diverter valve, a cooling lubricating oil way, an oil filtering plug screw and a net type oil filter. The oil pump diverter valve is used for being connected with an external heat exchanger, oil in an oil way is cooled, the temperature of lubricating oil is effectively reduced, and thermal safety of parts in the box body is guaranteed. Under the condition that other structures of the gearbox are not added, all-directional lubrication inside a rear-end transmission system is achieved, and the structural compactness and the space utilization rate are improved. Lubricating points of the lubricating system are comprehensively covered, oil duct connection of different shells is achieved through butt joint of the cross-joint-surface oil ducts, the lubricating system is compact in design, and the comprehensive performance, safety and reliability of a transmission system are improved in the aspects of heat dissipation, cooling, fatigue and efficiency of the system.

Description

Technical Field

[0001] This invention belongs to the field of transmission cooling and lubrication technology, and relates to a forced lubrication and cooling system for the rear end of a transmission with a parallel hydraulic retarder, and the transmission itself. Background Technology

[0002] When driving downhill on heavy loads carrying sand, aggregates, cement, etc., current pure electric mining trucks are prone to battery overcharging or motor overheating due to limitations in battery capacity and motor power, resulting in weak or lost motor power. In such cases, a hydraulic retarder is needed to provide braking force for the entire vehicle. The pure electric mining truck transmission assembly, by integrating a hydraulic retarder, can meet the extreme operating conditions of the aforementioned retarder, enhance the vehicle's braking requirements under heavy-load downhill conditions, and reduce the pressure on the current vehicle braking system.

[0003] However, due to the high-speed, heavy-load characteristics of pure electric mining trucks, the traditional single-box, three-intermediate-shaft transmission of pure electric mining trucks, with the integration of a hydraulic retarder at the rear end, cannot meet the lubrication requirements of all components within the transmission. Furthermore, the large amount of heat generated by heavy-load, high-speed meshing friction cannot be diverted and lubricated by the existing transmission lubrication system, failing to meet the cooling needs within the transmission and ensuring the thermal safety of components inside the gearbox. This results in reduced transmission lifespan, increased risk of oil leaks, increased oil circuit losses, and reduced oil pump efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a forced lubrication and cooling system for the rear end of a transmission with a parallel hydraulic retarder, and a transmission in general, to solve the technical problem that the lubrication system cannot achieve distributed lubrication and cannot meet the cooling requirements of the transmission after a hydraulic retarder is integrated at the rear end of a transmission with a three intermediate shaft structure.

[0005] To achieve the above objectives, the present invention employs the following technical solution: This invention discloses a forced lubrication and cooling system for the rear end of a transmission with a parallel hydraulic retarder, comprising: Fixed connection between the retarder bracket and the rear cover; The oil pump, power take-off side cover, and rear bearing cover are fixedly mounted on the retarder bracket; An oil pump guide valve fixedly mounted on the rear cover; A cooling and lubricating oil passage is formed inside and connected to the retarder bracket, rear cover, power take-off side cover and rear bearing cover. The outlet of the oil pump passes through the cooling and lubricating oil passage. The oil pump guide valve is connected in series in the cooling and lubricating oil passage. The cooling and lubricating oil passage is used to connect the retarder drive gear mounting cavity, the left intermediate shaft mounting cavity of the transmission, the right intermediate shaft mounting cavity of the transmission, the power take-off assembly and the rear end parts of the second shaft.

[0006] Furthermore, the cooling and lubrication oil circuit includes: The bracket has a second oil passage, a third oil passage, and a fourth oil passage, which are provided in the retarder bracket. The fourth oil passage is used to connect to the retarder drive gear mounting cavity. The rear cover has a first oil passage, a second oil passage, a left upper intermediate shaft lubrication hole, and a right upper intermediate shaft lubrication hole. The left upper intermediate shaft lubrication hole is used to connect to the left intermediate shaft mounting cavity of the transmission. The right upper intermediate shaft lubrication hole is used to connect to the right intermediate shaft mounting cavity of the transmission. A power take-off side cover oil passage is provided on the power take-off side cover, and the power take-off side cover oil passage is used to connect the power take-off assembly; A rear bearing cover oil passage is provided on the rear bearing cover, and the rear bearing cover oil passage is used to connect the rear end parts of the two shafts. The outlet of the oil pump is connected to the first oil circuit of the rear cover through the second oil circuit of the bracket. The first oil circuit of the rear cover is connected to the second oil circuit of the rear cover through the oil pump guide valve. The second oil circuit of the rear cover is connected to the lubrication hole of the upper left intermediate shaft, the lubrication hole of the upper right intermediate shaft and the third oil circuit of the bracket respectively. The third oil circuit of the bracket is connected to the oil circuit of the power take-off side cover, the oil circuit of the rear bearing cover and the fourth oil circuit of the bracket respectively.

[0007] Furthermore, it also includes an oil filter plug and a mesh filter. The oil filter plug is fixed on the retarder bracket, the outlet of the mesh filter is connected to the inlet of the oil filter plug, and the outlet of the oil filter plug is connected to the inlet of the oil pump.

[0008] Furthermore, the retarder bracket is provided with a first oil passage, and the outlet of the oil filter plug is connected to the inlet of the oil pump through the first oil passage.

[0009] Furthermore, the input end of the oil pump is provided with a connecting part, which is used to connect to the lower intermediate shaft of the transmission, and a safety relief valve is provided inside the oil pump.

[0010] Furthermore, two hollow bolts are fixed on the rear cover, and the two hollow bolts are connected through the oil pump guide valve. The oil pump guide valve is located outside the rear cover. The first oil passage of the rear cover is connected to one of the hollow bolts, and the other hollow bolt is connected to the second oil passage of the rear cover.

[0011] Furthermore, the rear cover is also provided with a third oil passage and a fourth oil passage. The second oil passage of the rear cover is connected to the third oil passage of the bracket through the third oil passage and the fourth oil passage. The third oil passage and the fourth oil passage of the rear cover are located between the lubrication hole of the upper left intermediate shaft and the lubrication hole of the upper right intermediate shaft.

[0012] Furthermore, the third oil circuit of the bracket includes the fifth oil circuit, the sixth oil circuit, and the seventh oil circuit of the bracket. The second oil circuit of the rear cover is connected to the fifth oil circuit, the sixth oil circuit, and the seventh oil circuit of the bracket, respectively. The fifth oil circuit of the bracket is connected to the oil circuit of the power take-off side cover. The sixth oil circuit of the bracket is connected to the oil circuit of the rear bearing cover. The seventh oil circuit of the bracket is connected to the fourth oil circuit of the bracket.

[0013] Furthermore, it also includes a second shaft rotatably connected to the retarder bracket, the second shaft having a second shaft oil passage, the second shaft oil collector sleeve and the second shaft rear bearing being provided between the retarder bracket and the second shaft, the retarder driven gear being sleeved on the second shaft, the sixth oil passage of the bracket being connected to the second shaft oil passage through the second shaft oil collector sleeve, the second shaft oil passage being connected to the cavity where the second shaft rear bearing is located and the cavity where the retarder driven gear is located respectively.

[0014] Based on the aforementioned parallel hydraulic retarder-based forced lubrication and cooling system for the rear end of the transmission, this invention also discloses a three-intermediate-shaft transmission integrating a hydraulic retarder, comprising: Retarder bracket; The hydraulic retarder assembly and the three intermediate shafts of the transmission are fixed on the retarder bracket. The hydraulic retarder assembly and the three intermediate shafts of the transmission are lubricated and cooled by a forced lubrication and cooling system at the rear end of the transmission with parallel hydraulic retarders.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The retarder bracket and rear cover of this invention are fixedly connected, forming a stable structural foundation and providing reliable support for the installation of other components. The oil pump, as the power source of the lubrication and cooling system, provides power for the circulation of lubricating oil within the system. Cooling lubricating oil passages are provided inside the PTO side cover and rear bearing cover, facilitating the delivery of lubricating oil to the PTO assembly and the rear-end components of the second shaft. An oil pump guide valve is used to connect to an external heat exchanger to cool the oil in the oil passages, effectively reducing the temperature of the lubricating oil and ensuring the thermal safety of components within the gearbox. The interconnected cooling lubricating oil passages inside the retarder bracket, rear cover, PTO side cover, and rear bearing cover fully utilize the existing rear cover, retarder bracket, PTO side cover, and rear bearing cover of the transmission to guide the lubricating oil, achieving all-around lubrication within the rear transmission system without adding other structures to the transmission, thus improving structural compactness and space utilization. Oil passage connections between different housings are achieved through cross-interface oil passage docking, minimizing the use of a single-assembly oil pipe. The cooling and lubrication oil circuit connects the retarder drive gear mounting cavity, the left intermediate shaft mounting cavity of the transmission, the right intermediate shaft mounting cavity of the transmission, the power take-off assembly, and the rear end parts of the second shaft, achieving lubrication and cooling of these components and meeting the lubrication and cooling requirements of each component under heavy-load, high-speed conditions. This invention optimizes the system in terms of heat dissipation, cooling, fatigue, and efficiency. It effectively solves the problems of traditional pure electric mining truck transmissions, after integrating a hydraulic retarder, where the lubrication system cannot meet the lubrication requirements of all components and cannot achieve distributed lubrication and effective cooling. This ensures the thermal safety of components within the transmission housing, improves transmission lifespan, reduces the risk of oil leakage, minimizes oil circuit losses, and improves oil pump efficiency, thereby enhancing the overall performance and reliability of the transmission system.

[0016] The retarder bracket of this invention serves as a key supporting component of the entire integrated system, providing a stable mounting foundation for the hydraulic retarder assembly and the three intermediate shaft transmission. The oil circuit integration base of the forced lubrication and cooling system at the rear end of the transmission with the parallel hydraulic retarder lubricates and cools the hydraulic retarder assembly and the three intermediate shaft transmission, covering all critical parts and ensuring adequate lubrication for each component during high-speed operation. An external heat exchanger connected to the oil pump guide valve further cools the oil in the oil circuit, effectively reducing the system's operating temperature. The rational transmission structure and optimized lubrication and cooling system of this invention work together to ensure good lubrication and effective cooling of the hydraulic retarder and transmission components, reducing the possibility of malfunctions, improving the reliability of the entire transmission system, reducing energy loss during power transmission, and increasing transmission efficiency. Attached Figure Description

[0017] Figure 1 This is a three-dimensional view of the overall structure of the transmission according to an embodiment of the present invention; Figure 2 This is a front view of the overall structure of the transmission according to an embodiment of the present invention; Figure 3 This is a schematic diagram illustrating the cooperation between the oil pump and the retarder bracket in an embodiment of the present invention; Figure 4 This is a partial oil circuit diagram of the retarder bracket according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the lubrication oil circuit of the rear cover according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the lubrication oil circuit of the retarder bracket body according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the lubrication oil circuit at the power take-off side cover according to an embodiment of the present invention; Figure 8 This is a schematic diagram of the lubrication oil circuit of the rear bearing cover and the two shafts according to an embodiment of the present invention; Figure 9 This is a schematic diagram of the lubrication oil circuit at the retarder gear and bearing in an embodiment of the present invention.

[0018] The components include: 1. Oil filter plug; 2. Oil pump; 3. Retarder bracket; 4. Oil pump guide valve; 5. Rear cover; 6. PTO side cover; 7. Hydraulic retarder assembly; 8. Rear bearing cover; 9. Mesh oil filter; 10. Hollow bolt; 11. Second shaft; 12. Second shaft oil collector sleeve; 13. Second shaft rear bearing; 14. Retarder driven gear; 15. Retarder drive gear mounting cavity; 151. Retarder drive gear; 152. Retarder drive gear bearing; 17. Lower intermediate shaft mounting cavity of the transmission; 18. Left intermediate shaft mounting cavity of the transmission; 19. Right intermediate shaft mounting cavity of the transmission; 20. Lower intermediate shaft of the transmission; 21. 1. Left intermediate shaft of the transmission; 22. Right intermediate shaft of the transmission; 201. Connecting part; 301. First oil passage of the bracket; 302. Second oil passage of the bracket; 303. Third oil passage of the bracket; 304. Fourth oil passage of the bracket; 305. Fifth oil passage of the bracket; 306. Sixth oil passage of the bracket; 307. Seventh oil passage of the bracket; 501. First oil passage of the rear cover; 502. Second oil passage of the rear cover; 503. Lubrication hole of the upper left intermediate shaft; 504. Lubrication hole of the upper right intermediate shaft; 505. Third oil passage of the rear cover; 506. Fourth oil passage of the rear cover; 601. Oil passage of the power take-off side cover; 801. Oil passage of the rear bearing cover; 1101. Oil passage of the second shaft. Detailed Implementation

[0019] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only 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.

[0020] It should be noted that the terms "first," "second," etc., in the specification 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, the terms "comprising" and "having," and any variations thereof, are intended to cover 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.

[0021] The present invention will now be described in further detail with reference to the accompanying drawings: See Figures 1 to 9 The present invention discloses a forced lubrication and cooling system for the rear end of a transmission with a parallel hydraulic retarder, comprising: an oil pump 2, a retarder bracket 3, an oil pump guide valve 4, a rear cover 5, a power take-off side cover 6, a rear bearing cover 8, and a cooling and lubrication oil circuit.

[0022] The retarder bracket 3 and the rear cover 5 are fixedly connected to form a stable structural foundation, providing reliable support for the installation of other components and ensuring the stability and integrity of the entire lubrication and cooling system structure.

[0023] The oil pump 2, the power take-off side cover 6, and the rear bearing cover 8 are fixedly mounted on the retarder bracket 3. The oil pump 2 serves as the power source for the lubrication and cooling system, providing power for the circulation of lubricating oil within the system, ensuring that the lubricating oil reaches all components requiring lubrication and cooling, and guaranteeing the normal operation of the system. Cooling and lubricating oil passages are provided inside the power take-off side cover 6 and the rear bearing cover 8, facilitating the delivery of lubricating oil to the power take-off assembly and the rear end components of the second shaft 11.

[0024] The oil pump guide valve 4 is fixed on the rear cover 5. The oil pump guide valve 4 is used to connect to an external heat exchanger to cool the oil in the oil circuit, effectively reducing the temperature of the lubricating oil and preventing the lubricating oil temperature from becoming too high due to the large amount of heat generated by heavy-load high-speed meshing friction, thereby ensuring the performance of the lubricating oil, meeting the cooling requirements of the gearbox, and ensuring the thermal safety of the components inside the gearbox.

[0025] A cooling and lubricating oil passage is formed inside and connected to the retarder bracket 3, rear cover 5, power take-off side cover 6, and rear bearing cover 8. The outlet of the oil pump 2 passes through this cooling and lubricating oil passage, making full use of the rear cover, retarder bracket, power take-off side cover, and rear bearing cover of the transmission itself to guide the lubricating oil. This achieves all-round lubrication of the rear transmission system without adding other structures to the transmission, improving structural compactness and space utilization. The oil passage connection between different housings is achieved by connecting the oil passages across the mating surfaces, minimizing the use of a single-assembly oil pipe, which has minimal impact on the internal space of the transmission and avoids the low installation efficiency of traditional oil pipes. The oil pump guide valve 4 is connected in series in the cooling and lubricating oil passage, which connects the retarder drive gear mounting cavity 15, the left intermediate shaft mounting cavity 18, the right intermediate shaft mounting cavity 19, the power take-off assembly, and the rear end parts of the second shaft 11, achieving lubrication and cooling of these components and meeting the lubrication and cooling requirements of each component under heavy-load and high-speed conditions.

[0026] This invention optimizes the system in terms of heat dissipation, cooling, fatigue, and efficiency. It effectively solves the problems of traditional pure electric mining truck transmissions where the lubrication system cannot meet the lubrication requirements of all components and cannot achieve distributed lubrication and effective cooling after integrating a hydraulic retarder. This ensures the thermal safety of components inside the transmission, helps to improve transmission life, reduce the risk of oil leakage, reduce oil circuit losses, and improve oil pump efficiency, thereby improving the overall performance and reliability of the transmission system.

[0027] Example 1: See Figures 1 to 9 This invention discloses a forced lubrication and cooling system for the rear end of a transmission with a parallel hydraulic retarder, comprising: a retarder bracket 3, a rear cover 5, an oil pump 2, a power take-off side cover 6, a rear bearing cover 8, an oil pump guide valve 4, a second oil passage 302 for the bracket, a third oil passage 303 for the bracket, a fourth oil passage 304 for the bracket, a first oil passage 501 for the rear cover, a second oil passage 502 for the rear cover, a lubrication hole 503 for the upper left intermediate shaft, a lubrication hole 504 for the upper right intermediate shaft, a mounting cavity 17 for the lower intermediate shaft of the transmission, a mounting cavity 18 for the left intermediate shaft of the transmission, a mounting cavity 19 for the right intermediate shaft of the transmission, an oil filter plug 1, and a mesh oil filter 9.

[0028] See Figure 1 and Figure 2 The retarder bracket 3 and the rear cover 5 provide a mounting base for other components, ensuring the stability of the entire lubrication and cooling system structure, enabling each component to be accurately installed and work together, and ensuring the stable operation of the lubrication circuit system.

[0029] See Figure 3In this embodiment of the invention, the oil filter plug 1 is fixed on the retarder bracket 3, the outlet of the mesh oil filter 9 is connected to the inlet of the oil filter plug 1, and the outlet of the oil filter plug 1 is connected to the inlet of the oil pump 2.

[0030] See Figure 3 The retarder bracket 3 is provided with a bracket first oil passage 301, and the outlet of the oil filter plug 1 is connected to the inlet of the oil pump 2 through the bracket first oil passage 301.

[0031] See Figure 1 , Figure 2 and Figure 8 The oil pump 2, the power take-off side cover 6, and the rear bearing cover 8 are fixedly mounted on the retarder bracket 3. The oil pump 2 serves as the power source for the lubrication system, providing power for the circulation of lubricating oil in the oil circuit. The power take-off side cover 6 provides an opening for the power take-off side cover oil circuit 601, through which the power take-off assembly is lubricated, ensuring normal operation of the power take-off and reducing malfunctions caused by lack of lubrication. The rear bearing cover 8 provides an opening for the rear bearing cover oil circuit 801, through which the rear end components of the second shaft 11 are connected and lubricated, reducing wear on the rear end components of the second shaft and extending their service life.

[0032] See Figure 3 In this embodiment of the invention, the input end of the oil pump 2 is provided with a connecting part 201, which is used to connect the lower intermediate shaft 20 of the transmission.

[0033] In this embodiment of the invention, a safety relief valve is provided inside the oil pump 2.

[0034] See Figure 4 The oil pump guide valve 4 is fixed on the rear cover 5. The oil pump guide valve 4 is used to connect to an external heat exchanger to cool the oil in the oil circuit, effectively reducing the temperature of the lubricating oil and avoiding excessive heat caused by heavy load and high speed meshing friction, thereby ensuring the performance of the lubricating oil, meeting the cooling requirements of the gearbox, and ensuring the thermal safety of the components inside the gearbox.

[0035] See Figure 4 , Figure 6 and Figure 9The retarder bracket 3 has a second oil passage 302, a third oil passage 303, and a fourth oil passage 304. The third oil passage 303 is connected to the power take-off side cover oil passage 601, the rear bearing cover oil passage 801, and the fourth oil passage 304, respectively, to achieve the distribution and transmission of lubricating oil among different components, ensuring that the power take-off assembly, the rear end parts of the second shaft, and the retarder drive gear mounting cavity are all lubricated. The fourth oil passage 304 is used to connect to the retarder drive gear mounting cavity 15, providing lubrication for the retarder drive gear, reducing gear wear, and ensuring the normal operation of the retarder drive gear.

[0036] See Figure 4 and Figure 5 The rear cover 5 contains a first oil passage 501, a second oil passage 502, a lubrication hole 503 for the upper left intermediate shaft, a lubrication hole 504 for the upper right intermediate shaft, a mounting cavity 17 for the lower intermediate shaft of the transmission, a mounting cavity 18 for the left intermediate shaft of the transmission, and a mounting cavity 19 for the right intermediate shaft of the transmission. The lubrication hole 503 for the upper left intermediate shaft is connected to the mounting cavity 18 for the left intermediate shaft of the transmission, and the lubrication hole 504 for the upper right intermediate shaft is connected to the mounting cavity 19 for the right intermediate shaft of the transmission. The lower intermediate shaft 20 of the transmission is located in the mounting cavity 17 for the lower intermediate shaft of the transmission. The left intermediate shaft 21 of the transmission is located in the mounting cavity 18 for the left intermediate shaft of the transmission. The right intermediate shaft 22 of the transmission is located in the mounting cavity 19 for the right intermediate shaft of the transmission. Lubrication is provided to these intermediate shafts through the corresponding lubrication holes and oil passages to ensure the normal operation of the transmission intermediate shaft system.

[0037] See Figure 7 The power take-off side cover 6 has an oil passage 601 for connecting to the power take-off side cover. The oil passage 601 is used to connect to the power take-off assembly, guide lubricating oil into the power take-off assembly, lubricate the power take-off, reduce friction between the various components of the power take-off, and improve the reliability and service life of the power take-off.

[0038] See Figure 8 The rear bearing cover 8 has a rear bearing cover oil passage 801, which is used to connect the rear end parts of the second shaft 11, provide lubrication for the rear end parts of the second shaft, reduce their wear, and ensure the normal operation of the second shaft system.

[0039] The outlet of the oil pump 2 is connected to the first oil passage 501 of the rear cover through the second oil passage 302 of the bracket. The first oil passage 501 of the rear cover is connected to the second oil passage 502 of the rear cover through the oil pump guide valve 4. The second oil passage 502 of the rear cover is connected to the lubrication hole 503 of the upper left intermediate shaft, the lubrication hole 504 of the upper right intermediate shaft, and the third oil passage 303 of the bracket. The third oil passage 303 of the bracket is connected to the oil passage 601 of the power take-off side cover, the oil passage 801 of the rear bearing cover, and the fourth oil passage 304 of the bracket.

[0040] See Figure 5 In this embodiment of the invention, two hollow bolts 10 are fixed on the rear cover 5. The two hollow bolts 10 are connected through the oil pump guide valve 4. The oil pump guide valve 4 is located outside the rear cover 5. The first oil passage 501 of the rear cover is connected to one of the hollow bolts 10, and the other hollow bolt 10 is connected to the second oil passage 502 of the rear cover.

[0041] See Figure 5 In this embodiment of the invention, the rear cover 5 is further provided with a third oil passage 505 and a fourth oil passage 506. The second oil passage 502 of the rear cover is connected to the third oil passage 303 of the bracket through the third oil passage 505 and the fourth oil passage 506 of the rear cover. The third oil passage 505 and the fourth oil passage 506 of the rear cover are located between the upper left intermediate shaft lubrication hole 503 and the upper right intermediate shaft lubrication hole 504.

[0042] See Figure 6 In this embodiment of the invention, the third oil passage 303 of the bracket includes a fifth oil passage 305, a sixth oil passage 306, and a seventh oil passage 307. The second oil passage 502 of the rear cover is connected to the fifth oil passage 305, the sixth oil passage 306, and the seventh oil passage 307 of the bracket. The fifth oil passage 305 is connected to the oil passage 601 of the power take-off side cover. The sixth oil passage 306 is connected to the oil passage 801 of the rear bearing cover. The seventh oil passage 307 is connected to the fourth oil passage 304 of the bracket.

[0043] See Figure 8 In this embodiment of the invention, a second shaft 11 rotatably connected to the retarder bracket 3 is also included. A second shaft oil passage 1101 is provided inside the second shaft 11. A second shaft oil collecting sleeve 12 and a second shaft rear bearing 13 are provided between the retarder bracket 3 and the second shaft 11. A retarder driven gear 14 is sleeved on the second shaft 11. The sixth oil passage 306 of the bracket is connected to the second shaft oil passage 1101 through the second shaft oil collecting sleeve 12. The second shaft oil passage 1101 is connected to the cavity where the second shaft rear bearing 13 is located and the cavity where the retarder driven gear 14 is located.

[0044] This invention's lubrication system comprehensively covers all critical components at the rear of the transmission, including intermediate shafts, the power take-off assembly, rear-end parts of the second shaft, and the retarder drive gear. This significantly reduces the failure rate of new energy transmission systems and improves their reliability. This invention improves the overall performance and safety of the transmission system in terms of heat dissipation, cooling, fatigue, and efficiency. Furthermore, the compact design of the lubrication system fully utilizes the transmission's existing rear cover 5, retarder bracket 3, power take-off side cover 6, and rear bearing cover 8 to guide the lubricating oil. This achieves all-around lubrication within the rear transmission system without adding other structures to the transmission, resulting in high lubrication reliability and a wide range of applications, including other similar heavy-duty transmission systems. This invention connects oil passages between different housings through cross-interface oil passage connection, minimizing the use of a single-unit oil pipe and minimally impacting the internal space of the transmission. It also avoids the low installation efficiency and high component costs associated with traditional oil pipes. Additionally, the large length-to-diameter ratio of the end spray nozzles provides excellent lubrication guidance and more precise lubrication.

[0045] See Figure 1 and Figure 2 Based on the above structure, the present invention also discloses a three-intermediate-shaft transmission with an integrated hydraulic retarder, comprising: a retarder bracket 3, a hydraulic retarder assembly 7, and a three-intermediate-shaft transmission.

[0046] The hydraulic retarder assembly 7 and the three-intermediate-shaft transmission are fixed on the retarder bracket 3. The hydraulic retarder assembly 7 and the three-intermediate-shaft transmission are lubricated and cooled by a forced lubrication and cooling system at the rear end of the transmission connected to the parallel hydraulic retarder. The retarder bracket 3, as a key supporting component of the entire integrated system, provides a stable mounting base for the hydraulic retarder assembly 7 and the three-intermediate-shaft transmission. The oil circuit integration base of the forced lubrication and cooling system at the rear end of the transmission connected to the parallel hydraulic retarder lubrication and cooling system lubricates and cools the hydraulic retarder assembly 7 and the three-intermediate-shaft transmission, covering all critical parts of the hydraulic retarder assembly and the three-intermediate-shaft transmission, ensuring sufficient lubrication for all components during high-speed operation. An external heat exchanger is connected via the oil pump guide valve 4 to cool the oil in the oil circuit, effectively reducing the system's operating temperature.

[0047] The invention's rational transmission structure and optimized lubrication and cooling system work together to ensure good lubrication and effective cooling of the hydraulic retarder and various transmission components, reducing the possibility of failure, improving the reliability of the entire transmission system, reducing energy loss during power transmission, and improving transmission efficiency.

[0048] Example 2: See Figures 1 to 9The purpose of this invention is to solve the problems of changes in lubrication structure, reduced transmission life, high risk of oil leakage, inconvenient installation, large oil circuit loss and low oil pump efficiency in traditional pure electric mining truck single-box three intermediate shaft structure transmissions after integrating a hydraulic retarder at the rear end. Therefore, this invention provides a forced lubrication and cooling system for the rear end of the transmission with a parallel hydraulic retarder.

[0049] This device includes a mesh oil filter 9, a separately detachable oil filter plug 1, an oil pump 2, an oil suction port, a pressure relief valve, a pump oil passage, a retarder bracket housing oil passage, an oil pump guide valve 4, a hollow bolt 10, a rear cover oil passage, a rear bearing cover oil passage 801, a power take-off side cover oil passage 601, a dual shaft oil collection sleeve 12, and a dual shaft oil passage 1101; The oil pump 2 is bolted to the retarder bracket 3. The inner rotor pin of the oil pump 2 is connected to the lower intermediate shaft 20 of the transmission via a connecting part 201. When the vehicle is moving forward, the lower intermediate shaft 20 of the transmission is used to input power to the oil pump 2. The inlet of the oil pump 2 is connected to the first oil passage 301 of the bracket, and oil is drawn in through the mesh filter 9 and the separately detachable oil filter plug 1. The outlet of the oil pump 2 is connected to the second oil passage 302 of the bracket for pumping oil. The safety relief valve is installed in the inner cavity of the oil pump 2 for pressure relief. The second oil passage 302 of the bracket is connected to the rear cover 5. The first oil passage 501 of the rear cover is connected, and the first oil passage 501 of the rear cover is connected to the second oil passage 502 of the rear cover through the oil pump guide valve 4 and the hollow bolt 10. A part of the outlet of the second oil passage 502 of the rear cover is used to force lubricate the rear bearing of the left intermediate shaft 21 and the rear bearing of the right intermediate shaft 22 of the transmission. The other part enters the third oil passage 303 of the bracket 3 through the third oil passage 505 and the fourth oil passage 506 of the rear cover. The third oil passage 303 of the bracket includes the fifth oil passage 305, the sixth oil passage 306 and the seventh oil passage 307. The fifth oil passage 305 of the bracket enters the interior of the power take-off unit through the power take-off side cover oil passage 601 of the power take-off side cover 6, and cools and lubricates the front bearing of the power take-off output gear shaft; the sixth oil passage 306 of the bracket enters the second shaft oil passage 1101 inside the second shaft 11 through the rear bearing cover oil passage 801 and the second shaft oil collection sleeve 12. The second shaft oil passage 1101 is connected to the cavity where the second shaft rear bearing 13 is located and the cavity where the retarder driven gear 14 is located, and is used to lubricate the relevant parts at the rear end of the second shaft 11; the seventh oil passage 307 of the bracket is connected to the fourth oil passage 304 of the bracket and enters the retarder drive gear mounting cavity 15, and is used to splash lubricate the retarder drive gear and the retarder drive gear bearing.

[0050] In summary, compared with the prior art, the advantages of the present invention are: This invention achieves a high degree of integration of the lubrication path by creating oil channels on the retarder bracket 3, without using separate oil pipes. Lubricating oil is supplied by an oil pump 2. This method results in a shorter oil suction pipe path, simpler oil pipe layout, less oil loss, higher oil pump efficiency, and a significant reduction in lubrication costs. Simultaneously, lubrication channels are created inside the second shaft 11, achieving multi-path lubrication. This enables forced lubrication of all critical components inside the gearbox, establishing a stable lubrication layer on the contact surfaces of the components and ensuring good flow of the lubrication layer. This effectively controls the temperature inside the gearbox within a safe range, greatly improving the reliability, practicality, and safety of the pure electric mining truck gearbox after being matched with a hydraulic retarder.

[0051] The lubrication system of this invention has comprehensive lubrication points, covering all key parts at the rear of the gearbox, which greatly reduces the failure rate of the new energy transmission system and improves the overall performance and safety reliability of the transmission system in terms of heat dissipation, cooling, fatigue, and efficiency. The lubrication system of this invention has a compact design, and the lubrication oil circuit design utilizes the rear cover 5, retarder bracket 3, power take-off side cover 6, and rear bearing cover 8 of the transmission itself to guide the lubricating oil. It achieves all-round lubrication inside the rear transmission system without adding other structures to the transmission, resulting in high lubrication reliability and a wide range of applicable applications.

[0052] The lubrication system of this invention completes the development of a hydraulic retarder matched with a pure electric drive system, which has great guiding significance for the development of hydraulic retarder matched with pure electric mining trucks.

[0053] For a three-intermediate-shaft transmission with a hydraulic retarder in parallel, this invention uses mechanical oil pump pressure for lubrication. The oil supply and lubrication of the key structures at the rear end of the three-intermediate-shaft transmission are achieved through a combination of housing oil passages, oil pump guide valves, and two-shaft oil circuits 1101. At the same time, a forced cooling interface is reserved at the initial position of the oil circuit, which can be connected to an external forced cooling system, thereby controlling the transmission oil temperature within a suitable range and greatly improving the service life of the transmission and the oil.

[0054] like Figure 1 As shown, the pure electric transmission with parallel hydraulic retarder of the present invention has a three-intermediate-shaft structure. The lower intermediate shaft 20 of the transmission at the rear end of the three intermediate shafts is connected to the input end of the oil pump 2 to provide oil pumping power to the oil pump 2. The right intermediate shaft 22 of the transmission is connected to the power take-off assembly to realize power take-off. The oil filter plug 1 at the rear end of the transmission is directly tightened on the retarder bracket 3. The mechanical oil pump, power take-off assembly, hydraulic retarder assembly, and rear bearing cover 8 are connected by bolts or double-ended studs and nuts. The rear cover 5 is installed on the front end of the retarder bracket 3 by bolts. The oil pump guide valve 4 is fixed to the side of the rear cover 5 by hollow bolts 10.

[0055] The rear-end lubrication and cooling system of the present invention can specifically realize the lubrication and cooling of the bearings, gears and other friction and transmission components of the transmission with the parallel hydraulic retarder assembly 7. The lubrication points mainly include the high-position bearing at the front end of the power take-off output shaft, the double-row tapered roller bearing at the rear end of the second shaft 11, the needle roller bearing below the retarder driven gear 14, the retarder drive gear 151, the retarder drive gear bearing 152, the rear bearing of the left intermediate shaft 21 of the transmission, the rear bearing of the right intermediate shaft 22 of the transmission and other points requiring lubrication.

[0056] The specific lubrication process of the rear-end lubrication and cooling system of the transmission of the present invention is as follows: like Figures 2 to 9 As shown, the forced lubrication system of the parallel hydraulic retarder transmission of this invention lubricates and cools key components at its rear end. It includes a mesh filter 9, a filter plug 1, an oil pump 2, a retarder bracket 3, an oil pump guide valve 4, a rear cover 5, and hollow bolts 10. The mesh filter 9 extends into the transmission housing and is fixed to the retarder bracket 3 by the filter plug 1. When the transmission is operating, the oil pump 2 draws oil from the mesh filter 9 and filter plug 1 through the housing oil passages of the retarder bracket 3 via the rotation of the lower intermediate shaft 20 of the transmission. Simultaneously, it releases pressure through its internal structure, exiting through the housing oil passages of the retarder bracket 3 and the rear cover 5. The oil then passes through the hollow bolt 10 and the oil pump guide valve 4 into the housing oil passages of the rear cover 5, with a portion used to lubricate the rear bearing of the right intermediate shaft 22 and the left intermediate shaft 2. Part of the oil entering the retarder bracket 3 housing oil passage and part entering the transmission housing are used to lubricate the relevant parts at the front end of the transmission. Part of the oil entering the retarder bracket 3 housing oil passage enters the power take-off through the oil hole of the power take-off side cover 6 to lubricate the high-position bearing inside the power take-off, part enters the second shaft oil collector sleeve 12 and the second shaft 11 through the rear bearing cover 8 to lubricate the second shaft rear bearing 13 and other parts, and the last part lubricates the retarder drive gear 151 and the retarder drive gear bearing 152 through the two inclined oil passages in the housing of the retarder bracket 3.

[0057] The lubrication method of this invention mainly arranges the main oil passage and lubrication branch oil passage on the housing parts, which not only makes the transmission structure compact, but also reduces the number of parts and ensures precise and reliable lubrication. In addition, the oil passages of different housings are connected by connecting the oil passages across the mating surfaces in several places, and the use of a general assembly oil pipe is avoided as much as possible, which has little impact on the internal space of the gearbox. At the same time, it avoids the problems of low installation efficiency and high part cost of traditional oil pipe input. In addition, the large length-to-diameter ratio of the end spray oil hole provides good lubrication guidance and more precise lubrication.

[0058] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of this invention.

Claims

1. A forced lubrication and cooling system for the rear end of a transmission with a parallel hydraulic retarder, characterized in that, include: The retarder bracket (3) and the rear cover (5) are fixedly connected; The oil pump (2), power take-off side cover (6) and rear bearing cover (8) are fixed on the retarder bracket (3). Oil pump guide valve (4) fixed on the rear cover (5); A cooling and lubricating oil passage is formed inside and connected to the retarder bracket (3), rear cover (5), power take-off side cover (6) and rear bearing cover (8). The outlet of the oil pump (2) passes through the cooling and lubricating oil passage. The oil pump guide valve (4) is connected in series on the cooling and lubricating oil passage. The cooling and lubricating oil passage is used to connect the retarder drive gear mounting cavity (15), the left intermediate shaft mounting cavity (18) of the transmission, the right intermediate shaft mounting cavity (19) of the transmission, the power take-off assembly and the rear end parts of the second shaft (11).

2. The forced lubrication and cooling system for the rear end of the transmission with a parallel hydraulic retarder according to claim 1, characterized in that, The cooling and lubrication circuit includes: The bracket has a second oil passage (302), a third oil passage (303), and a fourth oil passage (304) inside the retarder bracket (3). The fourth oil passage (304) is used to connect to the retarder drive gear mounting cavity (15). The rear cover (5) has a first oil passage (501), a second oil passage (502), a left upper intermediate shaft lubrication hole (503), and a right upper intermediate shaft lubrication hole (504). The left upper intermediate shaft lubrication hole (503) is used to connect to the left intermediate shaft mounting cavity (18) of the transmission, and the right upper intermediate shaft lubrication hole (504) is used to connect to the right intermediate shaft mounting cavity (19) of the transmission. A power take-off side cover oil passage (601) is provided on the power take-off side cover (6), and the power take-off side cover oil passage (601) is used to connect the power take-off assembly; A rear bearing cover oil passage (801) is provided on the rear bearing cover (8), the rear bearing cover oil passage (801) being used to connect the rear end parts of the two shafts (11); The outlet of the oil pump (2) is connected to the first oil passage of the rear cover (501) through the second oil passage of the bracket (302). The first oil passage of the rear cover (501) is connected to the second oil passage of the rear cover (502) through the oil pump guide valve (4). The second oil passage of the rear cover (502) is connected to the lubrication hole of the upper left intermediate shaft (503), the lubrication hole of the upper right intermediate shaft (504) and the third oil passage of the bracket (303) respectively. The third oil passage of the bracket (303) is connected to the oil passage of the power take-off side cover (601), the oil passage of the rear bearing cover (801) and the fourth oil passage of the bracket (304) respectively.

3. The forced lubrication and cooling system for the rear end of the transmission with a parallel hydraulic retarder according to claim 1, characterized in that, It also includes an oil filter plug (1) and a mesh filter (9). The oil filter plug (1) is fixed on the retarder bracket (3). The outlet of the mesh filter (9) is connected to the inlet of the oil filter plug (1). The outlet of the oil filter plug (1) is connected to the inlet of the oil pump (2).

4. The forced lubrication and cooling system for the rear end of the transmission with a parallel hydraulic retarder according to claim 3, characterized in that, The retarder bracket (3) is provided with a bracket first oil passage (301), and the outlet of the oil filter plug (1) is connected to the inlet of the oil pump (2) through the bracket first oil passage (301).

5. The forced lubrication and cooling system for the rear end of the transmission with a parallel hydraulic retarder according to claim 1, characterized in that, The oil pump (2) has a connecting part (201) at its input end. The connecting part (201) is used to connect the lower intermediate shaft (20) of the transmission. The oil pump (2) has a safety overflow valve inside its cavity.

6. The forced lubrication and cooling system for the rear end of the transmission with a parallel hydraulic retarder according to claim 1, characterized in that, Two hollow bolts (10) are fixed on the rear cover (5). The two hollow bolts (10) are connected through the oil pump guide valve (4). The oil pump guide valve (4) is located outside the rear cover (5). The first oil passage (501) of the rear cover is connected to one of the hollow bolts (10), and the other hollow bolt (10) is connected to the second oil passage (502) of the rear cover.

7. The forced lubrication and cooling system for the rear end of the transmission with a parallel hydraulic retarder according to claim 1, characterized in that, The rear cover (5) is also provided with a third oil passage (505) and a fourth oil passage (506). The second oil passage (502) of the rear cover is connected to the third oil passage (303) of the bracket through the third oil passage (505) and the fourth oil passage (506). The third oil passage (505) and the fourth oil passage (506) of the rear cover are located between the upper left intermediate shaft lubrication hole (503) and the upper right intermediate shaft lubrication hole (504).

8. The forced lubrication and cooling system for the rear end of the transmission with a parallel hydraulic retarder according to claim 1, characterized in that, The third oil passage (303) of the bracket includes the fifth oil passage (305), the sixth oil passage (306), and the seventh oil passage (307) of the bracket. The second oil passage (502) of the rear cover is connected to the fifth oil passage (305), the sixth oil passage (306), and the seventh oil passage (307) of the bracket, respectively. The fifth oil passage (305) of the bracket is connected to the oil passage (601) of the power take-off side cover. The sixth oil passage (306) of the bracket is connected to the oil passage (801) of the rear bearing cover. The seventh oil passage (307) of the bracket is connected to the fourth oil passage (304) of the bracket.

9. The forced lubrication and cooling system for the rear end of the transmission with a parallel hydraulic retarder according to claim 7, characterized in that, It also includes a second shaft (11) rotatably connected to the retarder bracket (3). The second shaft (11) has a second shaft oil passage (1101). The second shaft oil collection sleeve (12) and the second shaft rear bearing (13) are provided between the retarder bracket (3) and the second shaft (11). The retarder driven gear (14) is sleeved on the second shaft (11). The sixth oil passage (306) of the bracket is connected to the second shaft oil passage (1101) through the second shaft oil collection sleeve (12). The second shaft oil passage (1101) is connected to the cavity where the second shaft rear bearing (13) is located and the cavity where the retarder driven gear (14) is located.

10. A three-intermediate-shaft transmission with an integrated hydraulic retarder, characterized in that, include: Retarder bracket (3); The hydraulic retarder assembly (7) and the three intermediate shaft transmission are fixed on the retarder bracket (3). The hydraulic retarder assembly (7) and the three intermediate shaft transmission are lubricated and cooled by the forced lubrication and cooling system at the rear end of the transmission of the parallel hydraulic retarder as described in any one of claims 1 to 9.

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