A transmission rear cover with forced lubrication oil passage and integrated cylinder

Abstract

The application discloses a transmission rear cover with forced lubricating oil path and integrated cylinder, comprising an integrally formed rear cover shell, wherein an oil pump mechanism and a cylinder structure are integrated on the rear cover shell; the oil pump mechanism comprises an inner rotor, an outer rotor and an inner rotor shaft; the rear cover shell is provided with an oil pump oil suction port, an oil pump oil inlet channel, an oil pump oil outlet channel and shaft oil channels corresponding to a transmission input shaft, a first intermediate shaft and a second intermediate shaft, which are sequentially communicated; the shaft oil channels are communicated with the oil pump oil outlet channel; the cylinder structure comprises a piston fork shaft and a shift fork; the piston fork shaft and the shift fork are directly assembled on the rear cover shell; and the rear cover shell is integrally arranged with a cylinder shell. The application can solve the problems of the traditional transmission splash lubrication, such as insufficient effect under low-speed and climbing working conditions, additional oil pipe for forced lubrication, increased assembly difficulty, air leakage of the cylinder and the rear cover connection and loose bolts, and has the advantages of improving lubrication reliability, reducing fault risk, reducing cost and weight.

Description

Technical Field

[0001] This application belongs to the field of transmission technology, and specifically relates to a transmission rear cover with a forced lubrication circuit and an integrated cylinder. Background Technology

[0002] As a core component of the powertrain system, the lubrication and cooling of its key internal parts directly affect the fatigue life and operational reliability of the entire assembly. Currently, multi-speed transmissions both domestically and internationally primarily rely on splash lubrication, which depends on the high-speed rotation of gears or rotating parts carrying lubricating oil for lubrication. However, under low-speed driving and hill-climbing conditions, the lubricating oil supply from splash lubrication is insufficient, failing to meet the cooling and lubrication needs of critical components, and easily leading to premature wear or failure of parts.

[0003] To improve lubrication, some transmissions employ forced lubrication. However, existing forced lubrication solutions require additional oil lines to be installed inside the transmission to deliver lubricating oil. Due to the compact internal space of the transmission, the addition of oil lines not only increases assembly complexity but may also increase the risk of oil leakage due to vibration and friction of the oil lines, affecting system stability.

[0004] Furthermore, traditional transmission rear covers typically require bolts to assemble a separate cylinder housing to enable shifting. However, the mating surface between the cylinder housing and the rear cover is prone to air leakage due to poor sealing, and the connecting bolts are susceptible to loosening under long-term vibration, leading to incomplete shifting and seriously threatening driving safety. Additionally, assembling a separate cylinder housing increases the overall weight and material costs of the electric drive system, hindering vehicle lightweighting and cost control.

[0005] In view of the problems of insufficient lubrication, complex assembly, low sealing reliability and high cost and weight in the existing technology, there is an urgent need for an integrated and highly reliable transmission rear cover structure. Utility Model Content

[0006] The purpose of this application is to provide a transmission rear cover with a forced lubrication circuit and integrated cylinder, thereby solving the problems of insufficient lubrication, complex assembly, and unreliable cylinder connection in traditional transmissions mentioned in the background art.

[0007] To achieve the above objectives, this application adopts the following technical solution: A transmission rear cover with a forced lubrication circuit and an integrated cylinder includes a one-piece molded rear cover housing, on which an oil pump mechanism and a cylinder structure are integrated. The oil pump mechanism includes an inner rotor, an outer rotor, and an inner rotor shaft. The rear cover housing is provided with an oil pump suction port, an oil pump inlet passage, an oil pump outlet passage, and shaft-type oil passages corresponding to the transmission input shaft, the first intermediate shaft, and the second intermediate shaft, which are connected in sequence. The shaft-type oil passages are connected to the oil pump outlet passage. The cylinder structure includes a piston fork shaft and a shift fork, which are directly mounted on the rear cover housing. The rear cover housing and the cylinder housing are integrally formed.

[0008] In one possible implementation, the outer rotor is driven to the intermediate shaft of the transmission. The inner rotor meshes with the outer rotor, and the inner rotor is sleeved on the inner rotor shaft and rotates with the outer rotor.

[0009] In one possible implementation, the oil pump inlet passage is connected to the gap between the inner rotor and the outer rotor. The lubricating oil enters the gap through the oil pump suction port and the oil pump inlet passage, and forms high-pressure oil under the relative rotation of the inner rotor and the outer rotor, and is output through the oil pump outlet passage.

[0010] In one possible implementation, the shaft-type oil passage includes a first intermediate shaft oil passage, a second intermediate shaft oil passage, and an input shaft oil passage; The first intermediate shaft oil passage is connected to the shaft-type oil passage corresponding to the first intermediate shaft. The input shaft oil passage includes at least two branches, namely a second intermediate shaft oil passage and a fourth oil port; The fourth oil port directly lubricates the transmission input shaft, and the second intermediate shaft oil passage extends to the fifth oil port to lubricate the bearings of the second intermediate shaft.

[0011] In one possible implementation, the rear cover housing is further provided with a heat exchanger connection oil hole that communicates with the first oil passage. The first oil passage is connected to the oil pump outlet passage through a first oil port. The heat exchanger connection oil hole is used to connect to an external heat exchanger. The lubricating oil cooled by the heat exchanger flows back to the shaft oil passage through the return oil passage on the rear cover housing.

[0012] In one possible implementation, the return oil passage includes a first branch oil passage and a second branch oil passage; The first branch oil passage is connected to the first intermediate shaft oil passage; The second branch oil passage is connected to the input shaft oil passage. The input shaft oil passage supplies oil to the bearing lubrication points of the second intermediate shaft and the input shaft through the second intermediate shaft oil passage and the fourth oil port, respectively. The end of the second intermediate shaft oil passage is the fifth oil port.

[0013] In one possible implementation, the piston fork shaft and the shift fork are detachably connected by a pin, the pin being a solid structure, and the assembly of the piston fork shaft and the shift fork is directly embedded in the assembly groove of the rear cover housing.

[0014] In one possible implementation, there is a difference in the number of teeth between the inner rotor and the outer rotor, with the inner rotor having fewer teeth than the outer rotor, and the inner rotor and the outer rotor forming periodically changing high-pressure and low-pressure zones when rotating, in order to achieve continuous oil pumping.

[0015] In one possible implementation, the oil pump suction port is located at the lower part of the rear cover housing, and the oil pump outlet extends along the inner wall of the rear cover housing to the inlet of the shaft-type oil passage.

[0016] In one possible implementation, the rear cover housing and the transmission housing are sealed together by a flange face, the flange face being provided with a sealing groove, and a sealing ring being provided in the sealing groove.

[0017] Compared with the prior art, this application has the following beneficial effects: This application provides a transmission rear cover with a forced lubrication circuit and integrated cylinder. By integrating the oil pump mechanism and cylinder structure into the rear cover housing, the additional oil pipes and connecting bolts between the cylinder and the rear cover are eliminated. This solves the problem of insufficient splash lubrication under low-speed and climbing conditions, achieving precise forced lubrication of key components. It also avoids the risk of air leakage and bolt loosening at the joint surface between the cylinder and the rear cover. At the same time, it reduces the number of parts, lowers the cost and weight of the electric drive system, and improves driving safety.

[0018] In one possible implementation, the power of the intermediate shaft of the transmission is used to drive the inner and outer rotors to rotate, eliminating the need for an additional power source and simplifying the system structure. The inner and outer rotors are driven by meshing, which ensures the stability of power transmission, makes the oil pump output pressure uniform, and improves the reliability of the forced lubrication system.

[0019] In one possible implementation, the structure generates forced oil pumping through the relative rotation of the inner and outer rotors, which is unaffected by the transmission speed and can still ensure a sufficient supply of lubricating oil under low-speed conditions, thus overcoming the limitations of traditional splash lubrication. At the same time, the oil passages are integrated into the rear cover housing, reducing leakage points and improving the sealing performance of the lubrication system.

[0020] In one possible implementation, the oil passages of the first intermediate shaft and the input shaft are precisely connected to the bearing lubrication points of the input shaft and the first intermediate shaft, respectively, achieving precise lubrication, improving lubrication efficiency, and avoiding waste of lubricating oil; at the same time, targeted lubrication ensures that the bearings are adequately cooled during operation, extending the service life of the bearings.

[0021] In one possible implementation, by subdividing the shaft oil passages into a first intermediate shaft oil passage d2 and an input shaft oil passage e1, and setting two branches for the input shaft oil passage e1, precise and zoned lubrication of multiple bearings on the transmission input shaft, the first intermediate shaft, and the second intermediate shaft is achieved, avoiding the problem of uneven lubrication distribution in traditional lubrication methods. At the same time, the targeted branch design ensures that each bearing receives sufficient lubrication, effectively improving the cooling effect and service life of the bearings, and maintaining stable lubrication performance, especially under low-speed conditions.

[0022] In one possible implementation, the connection between the first oil passage and the first oil port enables a precise connection between the oil pump outlet and the heat exchanger, allowing the lubricating oil to be cooled before entering the lubrication point. This prevents high-temperature oil from exacerbating wear on components and significantly extends the fatigue life of key components such as gears and bearings. At the same time, the oil passage is integrated into the rear cover housing, eliminating the need for additional cooling pipes, simplifying the transmission structure, and reducing assembly difficulty and leakage risk.

[0023] In one possible implementation, the branched design of the return oil passage enables precise distribution of lubricating oil after cooling, allowing the bearings of the input shaft and the first intermediate shaft to simultaneously receive low-temperature lubricating oil, ensuring synchronous cooling of multiple lubrication points; the input shaft oil passage, through further subdivision of the second intermediate shaft oil passage and the fifth oil port, covers bearings at different positions on the second intermediate shaft, avoiding local lubrication blind spots and improving the comprehensiveness and reliability of lubrication; at the same time, the integrated oil passage design reduces pipeline connections, lowering maintenance costs and failure risks.

[0024] In one possible implementation, the tooth difference design between the inner and outer rotors enables the oil pump to generate a continuous and stable high-pressure oil output, avoiding pulsation during the oil supply process and ensuring the uniformity of lubricant delivery. The continuous pumping function ensures that key components can be continuously lubricated under various operating conditions of the transmission, solving the problem of insufficient oil supply under specific operating conditions caused by traditional splash lubrication. Attached Figure Description

[0025] Figure 1 A front view of a transmission rear cover with a forced lubrication circuit and an integrated cylinder provided in this application; Figure 2 This application provides a partial schematic diagram of an oil pump mechanism; Figure 3 for Figure 2 Cross-sectional view; Figure 4 This application provides a structural schematic diagram of the cross-section of a rear cover oil passage; Figure 5 This is a schematic diagram of the cylinder and rear cover integration provided in this application.

[0026] The attached diagram shows the following reference numerals: 1. Rear cover housing; 2. Oil pump mechanism; 3. Inner rotor shaft; 4. Inner rotor; 5. Outer rotor; 6. Piston fork shaft; 7. Pin; 8. Shift fork; 9. Transmission housing; a1. Oil pump suction port; a2. Oil pump inlet passage; b1. Oil pump outlet passage; b2. First oil port; b3. First oil passage; b4. Heat exchanger connecting oil hole; c1. Second oil port; c2. Return oil passage; d1. First branch oil passage; d2. First intermediate shaft oil passage; d3. Third oil port; e1. Input shaft oil passage; e2. Fourth oil port; e3. Second branch oil passage; f1. Second intermediate shaft oil passage; f2. Fifth oil port. Detailed Implementation

[0027] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0028] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application 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, and therefore should not be construed as a limitation of this application.

[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0030] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0031] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0032] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0033] like Figure 1 , Figure 2 and Figure 3 As shown, this application discloses a transmission rear cover with a forced lubrication oil circuit and an integrated cylinder. The transmission rear cover with a forced lubrication oil circuit and an integrated cylinder may include an integrally formed rear cover housing 1, on which an oil pump mechanism 2 and a cylinder structure are integrated.

[0034] Optionally, the rear cover housing 1 is made using an integrated molding process, on which the oil pump mechanism 2 and cylinder structure are directly integrated.

[0035] The oil pump mechanism 2 includes an inner rotor 4, an outer rotor 5, and an inner rotor shaft 3. The rear cover housing 1 is provided with an oil pump suction port a1, an oil pump inlet passage a2, an oil pump outlet passage b1 connected in sequence, as well as shaft-type oil passages corresponding to the transmission input shaft, the first intermediate shaft, and the second intermediate shaft. The shaft-type oil passages are connected to the oil pump outlet passage b1.

[0036] Optionally, the oil pump mechanism 2 may include an inner rotor 4, an outer rotor 5, and an inner rotor shaft 3. The rear cover housing 1 is machined with an oil pump suction port a1, an oil pump inlet passage a2, an oil pump outlet passage b1 connected in sequence, as well as shaft-type oil passages corresponding to the transmission input shaft, the first intermediate shaft, and the second intermediate shaft. The shaft-type oil passages are connected to the oil pump outlet passage b1 to deliver lubricating oil.

[0037] The cylinder structure includes a piston fork shaft 6 and a shift fork 8, which are directly mounted on the rear cover housing 1, and the rear cover housing 1 is integrally formed with the cylinder housing.

[0038] Specifically, the piston fork shaft 6 and shift fork 8 of the cylinder structure are directly assembled on the rear cover housing 1. The rear cover housing 1 is integrated with the original independent cylinder housing and does not require bolt connection.

[0039] In this embodiment, by integrating the oil pump mechanism 2 and the cylinder structure into the rear cover housing 1, the additional oil pipes and the connecting bolts between the cylinder and the rear cover are eliminated. This solves the problem of insufficient splash lubrication under low-speed and climbing conditions, achieves precise forced lubrication of key components, avoids the risk of air leakage and bolt loosening at the joint surface between the cylinder and the rear cover, reduces the number of parts, lowers the cost and weight of the electric drive system, and improves driving safety.

[0040] In one possible embodiment, the outer rotor 5 is driven to the intermediate shaft of the transmission.

[0041] Optionally, the outer rotor 5 is connected to the intermediate shaft of the gearbox via a transmission structure and rotates synchronously with the intermediate shaft.

[0042] The inner rotor 4 meshes with the outer rotor 5. The inner rotor 4 is sleeved on the inner rotor shaft 3 and rotates with the outer rotor 5.

[0043] Specifically, the inner rotor 4 meshes with the outer rotor 5. The inner rotor 4 is sleeved on the inner rotor shaft 3. When the outer rotor 5 rotates, it drives the inner rotor 4 to rotate synchronously around the inner rotor shaft 3 through the meshing action, thereby driving the oil pump.

[0044] In this embodiment, the inner and outer rotors 5 are driven to rotate by the power of the intermediate shaft of the transmission, eliminating the need for an additional power source and simplifying the system structure. The inner rotor 4 and the outer rotor 5 are driven by meshing, which ensures the stability of power transmission, makes the oil pump output pressure uniform, and improves the reliability of the forced lubrication system.

[0045] In one possible embodiment, the oil pump inlet a2 is connected to the gap between the inner rotor 4 and the outer rotor 5. The lubricating oil enters the gap through the oil pump suction port a1 and the oil pump inlet a2, and forms high-pressure oil under the relative rotation of the inner rotor 4 and the outer rotor 5, and is output through the oil pump outlet b1.

[0046] Optionally, the oil pump inlet a2 is connected to the gap between the inner rotor 4 and the outer rotor 5. The lubricating oil enters from the oil pump suction port a1 and flows into the gap between the inner and outer rotors 5 through the oil pump inlet a2.

[0047] As the inner rotor 4 and the outer rotor 5 rotate relative to each other, the void volume changes, forming high-pressure oil. The high-pressure oil is output to the subsequent oil passage through the oil pump outlet b1, completing the oil pumping process.

[0048] In this embodiment, the structure forms a forced oil pump by the relative rotation of the inner rotor 4 and the outer rotor 5, which is not affected by the speed of the transmission and can still ensure a sufficient supply of lubricating oil under low-speed conditions, thus solving the limitations of traditional splash lubrication. At the same time, the oil passage is integrated into the rear cover housing 1, which reduces leakage points and improves the sealing performance of the lubrication system.

[0049] In one possible embodiment, such as Figure 3 , Figure 4 and Figure 5 The shaft-type oil passage includes a first intermediate shaft oil passage d2, a second intermediate shaft oil passage f1, and an input shaft oil passage e1. The first intermediate shaft oil passage d2 is connected to the shaft-type oil passage corresponding to the first intermediate shaft, and the input shaft oil passage e1 is connected to the bearing lubrication point of the transmission input shaft.

[0050] The inlet of the first intermediate shaft oil passage d2 is connected to the first branch oil passage d1 of the return oil passage c2, and the outlet is connected to the shaft-type oil passage corresponding to the intermediate shaft, directly supplying lubricating oil to the shaft-type oil passage.

[0051] The inlet of the input shaft oil passage e1 is connected to the second branch oil passage e3 of the return oil passage c2. It can contain two branches: the fourth oil port e2 and the second intermediate shaft oil passage f1. The fourth oil port e2 directly lubricates the transmission input shaft. The second intermediate shaft oil passage f1 extends to the fifth oil port f2. The fifth oil port f2 is aligned and used to directly lubricate the second intermediate shaft bearing, thereby achieving separate lubrication of the bearings at two different positions on the second intermediate shaft and the transmission input shaft.

[0052] In this embodiment, by subdividing the shaft oil passages into a first intermediate shaft oil passage d2 and an input shaft oil passage e1, and setting two branches for the input shaft oil passage e1, precise and zoned lubrication of multiple bearings on the transmission input shaft, the first intermediate shaft, and the second intermediate shaft is achieved, avoiding the problem of uneven lubrication distribution in traditional lubrication methods. At the same time, the targeted branch design ensures that each bearing can obtain sufficient lubrication, effectively improving the cooling effect and service life of the bearings, and maintaining stable lubrication performance, especially under low-speed conditions.

[0053] In one possible embodiment, the rear cover housing 1 is further provided with a heat exchanger connection oil hole b4 that communicates with the first oil passage b3. The first oil passage b3 is connected to the oil pump outlet passage b1 through the first oil port b2. The heat exchanger connection oil hole b4 is used to connect to an external heat exchanger. The lubricating oil cooled by the heat exchanger flows back to the shaft oil passage through the return oil passage c2 on the rear cover housing 1.

[0054] Specifically, the rear cover housing 1 is provided with a first oil passage b3, one end of which is connected to the oil pump outlet passage b1 through the first oil port b2, and the other end is connected to the heat exchanger connecting oil hole b4. The oil hole b4 is connected to the external heat exchanger through a pipeline.

[0055] The high-pressure lubricating oil output by the oil pump enters the heat exchanger connecting oil hole b4 through the oil pump outlet b1, the first oil port b2, and the first oil passage b3. After flowing into the external heat exchanger for cooling, it flows back through the return oil passage c2 on the rear cover housing 1 and is finally distributed to the first intermediate shaft oil passage d2 and the input shaft oil passage e1, etc.

[0056] In this embodiment, the connection between the first oil passage b3 and the first oil port b2 enables a precise connection between the oil pump outlet passage b1 and the heat exchanger, allowing the lubricating oil to be cooled before entering the lubrication point, thus preventing high-temperature oil from aggravating the wear of parts and significantly extending the fatigue life of key components such as gears and bearings. At the same time, the oil passage is integrated into the rear cover housing 1, eliminating the need for additional cooling pipes, simplifying the transmission structure, and reducing assembly difficulty and leakage risk.

[0057] In one possible embodiment, the return oil passage c2 includes a first branch oil passage d1 and a second branch oil passage e3. The first branch oil passage d1 is connected to the first intermediate shaft oil passage d2.

[0058] Optionally, the return oil passage c2 is divided into a first branch oil passage d1 and a second branch oil passage e3. The inlet of the first branch oil passage d1 is connected to the return oil end of the heat exchanger, and the outlet is connected to the first intermediate shaft oil passage d2, so as to guide the cooled lubricating oil into the shaft-type oil passage corresponding to the first intermediate shaft.

[0059] The second branch oil passage e3 is connected to the input shaft oil passage e1. The input shaft oil passage e1 supplies oil to the two bearing lubrication points of the second intermediate shaft and the input shaft through the second intermediate shaft oil passage f1 and the fourth oil port e2, respectively. The end of the second intermediate shaft oil passage f1 is the fifth oil port f2.

[0060] Optionally, the inlet of the second branch oil passage e3 is also connected to the return oil end of the heat exchanger, and the outlet is connected to the input shaft oil passage e1. The input shaft oil passage e1 supplies oil to the shaft-type oil passages corresponding to the second intermediate shaft and the input shaft of the transmission through its branches, the second intermediate shaft oil passage f1 and the fifth oil port e2, respectively. The end of the second intermediate shaft oil passage f1 is the fifth oil port f2, which is directly aligned with the bearing lubrication point of the second intermediate shaft.

[0061] In this embodiment, the branch design of the return oil passage c2 enables precise distribution of lubricating oil after cooling, allowing the bearings of the transmission input shaft and the first intermediate shaft to simultaneously receive low-temperature lubricating oil, ensuring synchronous cooling of multiple lubrication points; the input shaft oil passage e1, through further subdivision of the second intermediate shaft oil passage f1 and the fifth oil port e2, covers bearings at different positions on the second intermediate shaft, avoiding local lubrication blind spots and improving the comprehensiveness and reliability of lubrication; at the same time, the integrated oil passage design reduces pipeline connections, lowering maintenance costs and failure risks.

[0062] In one possible embodiment, the piston fork shaft 6 and the shift fork 8 are detachably connected by a pin 7, which is a solid structure, and the assembly of the piston fork shaft 6 and the shift fork 8 is directly embedded in the assembly groove of the rear cover housing 1.

[0063] Optionally, the piston fork shaft 6 and the shift fork 8 are detachably connected by a solid pin 7. During assembly, the pin 7 is first inserted into the corresponding pin holes of the piston fork shaft 6 and the shift fork 8 to complete the connection between the two. Then, the assembly assembly is directly embedded into the assembly groove of the rear cover housing 1 without the need for bolt fixation. During disassembly, the two can be separated simply by pulling out the pin 7.

[0064] In this embodiment, the piston fork shaft 6 and the shift fork 8 are connected by a solid pin 7 and directly embedded in the assembly groove of the rear cover housing 1, eliminating the traditional bolt connection, avoiding shifting failures caused by loose bolts, and improving the reliability of shifting and driving safety; at the same time, the detachable pin 7 connection and the direct embedding assembly method simplify the assembly and maintenance process and improve the efficiency of production and after-sales maintenance.

[0065] In one possible embodiment, the inner rotor 4 and the outer rotor 5 have a difference in the number of teeth, with the inner rotor 4 having fewer teeth than the outer rotor 5. When the inner rotor 4 and the outer rotor 5 rotate, they form periodically changing high-pressure and low-pressure zones to achieve continuous oil pumping.

[0066] Optionally, there is a difference in the number of teeth between the inner rotor 4 and the outer rotor 5, and the number of teeth of the inner rotor 4 is less than that of the outer rotor 5. When the two rotate, due to the difference in the number of teeth, the volume of the gap between the inner rotor 4 and the outer rotor 5 will change periodically, forming alternating low-pressure zone and high-pressure zone. The low-pressure zone draws in lubricating oil, and the high-pressure zone discharges lubricating oil, thereby realizing continuous oil pumping.

[0067] In this embodiment, the tooth difference design between the inner rotor 4 and the outer rotor 5 enables the oil pump to generate a continuous and stable high-pressure oil output, avoiding pulsation during the oil supply process and ensuring the uniformity of lubricant delivery; the continuous oil pumping function ensures that key components can be continuously lubricated under various operating conditions of the transmission, solving the problem of insufficient oil supply under specific operating conditions caused by traditional splash lubrication.

[0068] In one possible embodiment, the oil pump suction port a1 is located at the lower part of the rear cover housing 1, and the oil pump outlet port b1 extends along the inner wall of the rear cover housing 1 to the inlet of the shaft-type oil passage.

[0069] Specifically, the oil pump suction port a1 is located at the lower part of the rear cover housing 1, close to the transmission oil pan, to facilitate the intake of lubricating oil from the oil pan; the oil pump outlet channel b1 extends along the inner wall of the rear cover housing 1, and its end is connected to the inlet of the shaft oil channel. The direction of the oil channel conforms to the internal structure of the rear cover housing 1 to avoid interference with other components.

[0070] In this embodiment, the oil pump suction port a1 is located at the bottom, which ensures that lubricating oil can be stably drawn in even when the transmission oil level fluctuates, thus avoiding the phenomenon of cavitation. The oil pump outlet b1 extends along the inner wall of the rear cover housing 1, making full use of the internal space of the housing, without affecting the assembly of other components, while reducing the exposed part of the oil passage and reducing the risk of oil passage damage and leakage.

[0071] In one possible embodiment, the rear cover housing 1 and the transmission housing 9 are sealed together by a flange face, the flange face being provided with a sealing groove, and a sealing ring being provided in the sealing groove.

[0072] Optionally, the rear cover housing 1 and the transmission housing 9 are connected by a flange face. A sealing groove is machined on the flange face, and a sealing ring is installed in the sealing groove. During assembly, the flange face is tightened by bolts, causing the sealing ring to deform under pressure and fill the sealing groove, thereby achieving a seal between the rear cover housing 1 and the transmission housing 9.

[0073] In this embodiment, the sealing structure of the flange face and the sealing ring improves the sealing performance between the rear cover housing 1 and the transmission housing 9, effectively preventing the leakage of lubricating oil inside the transmission and the entry of external dust and impurities, ensuring the cleanliness of the transmission interior and the normal operation of the lubrication system; at the same time, the sealing structure adapts to the vibration conditions during vehicle operation, improving the overall sealing performance and reliability of the transmission.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them; although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications to the technical solutions described in the foregoing embodiments, or equivalent substitutions for some or all of the technical features, do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A transmission rear cover with a forced lubrication circuit and an integrated cylinder, characterized in that, It includes an integrally molded rear cover housing (1), on which an oil pump mechanism (2) and a cylinder structure are integrated; The oil pump mechanism (2) includes an inner rotor (4), an outer rotor (5) and an inner rotor shaft (3). The rear cover housing (1) is provided with an oil pump suction port (a1), an oil pump inlet passage (a2), an oil pump outlet passage (b1) connected in sequence, and shaft-type oil passages corresponding to the transmission input shaft, the first intermediate shaft and the second intermediate shaft. The shaft-type oil passages are connected to the oil pump outlet passage (b1). The cylinder structure includes a piston fork shaft (6) and a shift fork (8), which are directly mounted on the rear cover housing (1). The rear cover housing (1) is integrated with the cylinder housing.

2. The transmission rear cover with a forced lubrication circuit and integrated cylinder according to claim 1, characterized in that, The outer rotor (5) is connected to the intermediate shaft of the transmission for power transmission. The inner rotor (4) meshes with the outer rotor (5), and the inner rotor (4) is sleeved on the inner rotor shaft (3) and rotates with the outer rotor (5).

3. The transmission rear cover with a forced lubrication circuit and integrated cylinder according to claim 1, characterized in that, The oil pump inlet channel (a2) is connected to the gap between the inner rotor (4) and the outer rotor (5). The lubricating oil enters the gap through the oil pump suction port (a1) and the oil pump inlet channel (a2), and forms high-pressure oil under the relative rotation of the inner rotor (4) and the outer rotor (5), and is output through the oil pump outlet channel (b1).

4. The transmission rear cover with a forced lubrication circuit and integrated cylinder according to claim 1, characterized in that, The shaft oil passages include a first intermediate shaft oil passage (d2), a second intermediate shaft oil passage (f1), and an input shaft oil passage (e1). The first intermediate shaft oil passage (d2) is connected to the shaft-type oil passage corresponding to the first intermediate shaft; The input shaft oil passage (e1) includes at least two branches, namely the second intermediate shaft oil passage (f1) and the fourth oil port (e2). The fourth oil port (e2) directly lubricates the transmission input shaft, and the second intermediate shaft oil passage (f1) extends to the fifth oil port (f2).

5. The transmission rear cover with a forced lubrication circuit and integrated cylinder according to claim 1, characterized in that, The rear cover housing (1) is also provided with a heat exchanger connecting oil hole (b4) that communicates with the first oil passage (b3). The first oil passage (b3) is connected to the oil pump outlet passage (b1) through the first oil port (b2). The heat exchanger connecting oil hole (b4) is used to connect to an external heat exchanger. The lubricating oil cooled by the heat exchanger flows back to the shaft oil passage through the return oil passage (c2) on the rear cover housing (1).

6. The transmission rear cover with a forced lubrication circuit and integrated cylinder according to claim 5, characterized in that, The return oil passage (c2) includes a first branch oil passage (d1) and a second branch oil passage (e3); The first branch oil passage (d1) is connected to the first intermediate shaft oil passage (d2); The second branch oil passage (e3) is connected to the input shaft oil passage (e1). The input shaft oil passage (e1) supplies oil to the bearing lubrication points of the second intermediate shaft and the input shaft through the second intermediate shaft oil passage (f1) and the fourth oil port (e2), respectively. The end of the second intermediate shaft oil passage (f1) is the fifth oil port (f2).

7. The transmission rear cover with a forced lubrication circuit and integrated cylinder according to claim 1, characterized in that, The piston fork shaft (6) and the shift fork (8) are detachably connected by a pin (7), which is a solid structure. The assembly of the piston fork shaft (6) and the shift fork (8) is directly embedded in the assembly groove of the rear cover housing (1).

8. The transmission rear cover with a forced lubrication circuit and integrated cylinder according to claim 1, characterized in that, There is a difference in the number of teeth between the inner rotor (4) and the outer rotor (5). The number of teeth of the inner rotor (4) is less than the number of teeth of the outer rotor (5). When the inner rotor (4) and the outer rotor (5) rotate, they form a periodically changing high-pressure zone and a low-pressure zone to achieve continuous oil pumping.

9. The transmission rear cover with a forced lubrication circuit and integrated cylinder according to claim 1, characterized in that, The oil pump suction port (a1) is located at the lower part of the rear cover housing (1), and the oil pump outlet (b1) extends along the inner wall of the rear cover housing (1) to the inlet of the shaft-type oil passage.

10. The transmission rear cover with a forced lubrication circuit and integrated cylinder according to claim 1, characterized in that, The rear cover housing (1) and the transmission housing (9) are sealed together by a flange face, and a sealing groove is provided on the flange face, and a sealing ring is provided in the sealing groove.

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