Planetary gear coaxial speed reducer lubricating structure

Abstract

The utility model discloses a planet gear coaxial type speed reducer lubricating structure which comprises a shell and a planet carrier differential mechanism assembly. The planet carrier differential mechanism assembly comprises a planet carrier differential shell, a planet gear train and a differential mechanism, the planet carrier differential shell is rotationally supported in the shell, and the planet gear train and the differential mechanism are integrally arranged in the planet carrier differential shell; the planetary gear train comprises a sun gear and a duplicate gear; the multiple duplicate gears are evenly distributed in the circumferential direction with the sun gear as the center and rotationally installed on the planet carrier differential shell through planet step pin shafts and needle bearings. The duplicate gear is integrated with a first-stage gear and a second-stage gear, the first-stage gear is meshed with the sun gear, and the second-stage gear is meshed with an inner gear ring fixed to the inner wall of the shell. An oil guide structure is arranged on the inner wall of the shell, and an oil guide disc is arranged on the planet carrier differential shell. The speed reducer has a good lubricating effect on the bearing.

Description

Technical Field

[0001] This utility model relates to reducer lubrication technology, specifically to a lubrication structure for a planetary gear coaxial reducer. Background Technology

[0002] With the rapid development of new energy vehicles, the transmission structure of electric drive systems has undergone technological innovation from traditional split design to highly integrated design. Early electric drive systems mostly adopted a separate layout for the motor, reducer, and controller, which resulted in problems such as large size and low efficiency.

[0003] In recent years, the industry has gradually achieved highly integrated solutions, including three-in-one (motor, reducer, and controller) and even multi-in-one solutions, through modular design and technological integration. Meanwhile, the introduction of technologies such as 800V high-voltage platforms and silicon carbide (SiC) electronic controls has further promoted the efficiency and lightweighting of electric drive systems.

[0004] Currently, most electric drive systems use parallel shaft reducers, which are relatively large, space-consuming, heavy, and inefficient. Therefore, a planetary gear coaxial reducer was designed. However, the lubrication performance of this reducer under high temperature, high speed, and high load conditions still needs improvement. Utility Model Content

[0005] The purpose of this utility model is to provide a lubrication structure for a planetary gear coaxial reducer, which provides better lubrication for the bearings and has high lubrication reliability, in order to address the above-mentioned problems.

[0006] This utility model is achieved through the following technical solution:

[0007] This utility model provides a lubrication structure for a coaxial planetary gear reducer, including a housing and a planetary carrier differential assembly. The planetary carrier differential assembly includes a planetary carrier differential housing, a planetary gear train, and a differential. The planetary carrier differential housing is rotatably supported within the housing, and the planetary gear train and differential are integrated within the planetary carrier differential housing. The planetary gear train includes a sun gear and a double gear. Multiple double gears are evenly distributed circumferentially around the sun gear and are rotatably mounted on the planetary carrier differential housing via planetary step pins and needle roller bearings. The double gear integrates a primary gear and a secondary gear. The primary gear meshes with the sun gear, and the secondary gear meshes with an internal gear ring fixed on the inner wall of the housing. An oil guiding structure is provided on the inner wall of the housing, and an oil guiding disc is provided on the planetary carrier differential housing. The oil guiding structure guides lubricating oil splashed onto the inner wall of the housing into the oil guiding disc, and the lubricating oil in the oil guiding disc flows to the needle roller bearings.

[0008] As a preferred embodiment of this utility model, the oil guide plate is in the shape of a ring and the inner wall is recessed to form an oil guide groove. A plurality of protrusions are evenly distributed along the circumference on one side of the oil guide plate. The protrusions extend along the axial direction and have an oil guide hole at the center. The oil guide hole is connected to the oil guide groove.

[0009] As a preferred embodiment of this utility model, the planetary step pin is a hollow structure, the protrusion extends into the interior of the planetary step pin, and a radial oil hole communicating with the interior is provided on the outer wall of the planetary step pin, the radial oil hole introducing lubricating oil into the needle roller bearing.

[0010] As a preferred embodiment of this utility model, the radial radius of the bottom of the oil guide groove gradually decreases from the center of the protrusion to both sides.

[0011] As a preferred embodiment of this utility model, a plurality of oil stirring ribs are evenly arranged circumferentially on the outer peripheral wall of the oil guide plate.

[0012] As a preferred embodiment of the present invention, the oil guiding structure on the inner wall of the housing includes an oil guiding channel, which extends to the rotational support position of the planetary carrier differential housing to guide the lubricating oil splashed onto the inner wall of the housing to the rotational support position of the planetary carrier differential housing.

[0013] As a preferred embodiment of this utility model, the oil guiding structure on the inner wall of the housing includes an oil unloading groove and an oil guiding rib. The oil unloading groove extends from the rotation support position of the planetary carrier housing to the oil guiding rib, and the oil guiding rib can guide the surface lubricating oil into the oil guiding plate.

[0014] As a preferred embodiment of this utility model, the oil guiding structure on the inner wall of the housing includes an oil return groove so that the lubricating oil on the housing flows into the bottom of the reducer.

[0015] As a preferred embodiment of this utility model, the housing includes a reducer end housing and a motor end housing, which are connected by a flange. One end of the planetary carrier differential housing is rotatably supported on the inner wall of the reducer end housing by a bearing, and the other end of the planetary carrier differential housing is rotatably supported on the inner wall of the motor end housing by a bearing.

[0016] As a preferred embodiment of this utility model, the differential includes planetary gears, half-shaft gears, and planetary gear shafts. There are two half-shaft gears arranged opposite each other along the rotation axis of the planetary carrier differential housing. The planetary gear shaft is perpendicular to the rotation axis of the planetary carrier differential housing. There are two planetary gears mounted on the planetary gear shaft. The two planetary gears mesh with the two half-shaft gears. A spherical washer is provided between the planetary gears and the planetary carrier differential housing, and the spherical washer is mounted on the planetary gear shaft. A half-shaft washer is provided between the half-shaft gears and the planetary carrier differential housing, and the half-shaft washer is mounted on the half-shaft gear.

[0017] Compared with the prior art, this utility model has the following advantages and beneficial effects:

[0018] 1. The reducer in this utility model includes a housing and a planetary carrier differential assembly disposed inside it. The planetary carrier differential assembly includes a planetary carrier differential housing, a planetary gear train, and a differential. The planetary carrier differential housing is rotatably supported inside the housing. External power is input to the planetary gear train to drive the planetary carrier differential housing to rotate, and the differential outputs power to achieve the wheel end speed difference. Since the planetary gear train and the differential are integrated in the planetary carrier differential housing, and the input axis of the planetary gear train, the rotation axis of the planetary carrier differential housing, and the output axis of the differential are coaxially arranged, the overall size of the reducer is smaller, which is beneficial for its installation and arrangement on the vehicle. Moreover, the overall weight is lighter and the efficiency is higher.

[0019] 2. The reducer in this utility model has an oil guiding structure on the inner wall of the housing and an oil guiding plate on the planetary carrier differential housing. The oil guiding channel in the oil guiding structure can guide the lubricating oil splashed on the inner wall of the housing to the bearings at both ends of the planetary carrier differential housing. At the same time, the oil discharge groove can guide the lubricating oil overflowing from the bearing to the oil guiding rib. The oil guiding rib can guide the lubricating oil into the oil guiding groove in the oil guiding plate. When the oil guiding plate rotates, the lubricating oil can flow to the needle roller bearing through the oil guiding hole and radial oil hole. The reducer has a good lubrication effect on the bearing and high lubrication reliability when it is working. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the exemplary embodiments of this utility model, the drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this utility model and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings:

[0021] Figure 1 This is a schematic diagram of the planetary gear coaxial reducer in this utility model;

[0022] Figure 2 This is a schematic diagram of the planetary carrier differential in this utility model;

[0023] Figure 3 This is a schematic diagram of the lubrication circuit for the needle roller bearing in this utility model;

[0024] Figure 4 This is a schematic diagram of the oil guide plate structure in this utility model;

[0025] Figure 5 This is a schematic diagram of the reducer end housing structure in this utility model.

[0026] The attached diagram shows the markings and corresponding component names:

[0027] 1-Sun gear, 2-Internal gear ring, 21-Spline, 22-Retaining ring, 3-Double gear, 31-First stage gear, 32-Second stage gear, 4-Planetary carrier differential housing, 41-Mounting hole, 5-Planetary step pin, 51-Radial oil hole, 6-Motor end housing, 7-Reducer end housing, 71-Oil guide passage, 72-Spline, 73-Oil guide rib, 74-Oil return groove, 75-Oil discharge groove, 76-Bearing hole, 8-Needle roller bearing, 9-Differential, 91-Planetary gear, 92-Spherical washer, 93-Half shaft gear, 94-Half shaft washer, 95-Planetary gear shaft, 96-Limit pin, 10-Bearing, 11-Bearing, 12-Oil guide plate, 121-Oil guide hole, 123-Oil stirring rib, 124-Oil guide groove, 13-Screw. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of this utility model are only used to explain this utility model and are not intended to limit this utility model.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0030] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly indicating the number, specific order, or primary and secondary relationship of the indicated technical features.

[0031] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0032] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A exists, A and B exist simultaneously, and B exists. In addition, the character " / " in this document generally indicates that the related objects before and after it have an "or" relationship.

[0033] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0034] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces), unless otherwise explicitly specified.

[0035] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of 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. Therefore, they should not be construed as limitations on the embodiments of this application.

[0036] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" 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 or an electrical 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. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0037] Please refer to Figures 1 to 5 This application provides a lubrication structure for a coaxial planetary gear reducer, comprising a housing and a planetary carrier differential assembly. The housing has an internal cavity, and the planetary carrier differential assembly is disposed within the cavity. The planetary carrier differential assembly includes a planetary carrier differential housing 4, a planetary gear train, and a differential 9. The planetary carrier differential housing 4 is rotatably supported on the inner wall of the housing. The planetary gear train and the differential 9 are integrated within the planetary carrier differential housing 4. External power input to the planetary gear train drives the planetary carrier differential housing 4 to rotate, and the differential 9 outputs power to achieve the wheel end speed difference. The input axis of the planetary gear train, the rotation axis of the planetary carrier differential housing 4, and the output axis of the differential 9 are coaxially arranged. An oil guide structure is provided on the inner wall of the housing, and an oil guide disc 12 is provided on the planetary carrier differential housing 4.

[0038] The reducer in this application integrates the planetary gear train and differential 9 within the planetary carrier and differential housing 4. Furthermore, the input axis of the planetary gear train, the rotation axis of the planetary carrier and differential housing 4, and the output axis of the differential 9 are coaxially arranged. Compared to existing parallel-shaft reducers, this integrated coaxial reducer has a smaller overall size, offering space advantages and facilitating its installation in the vehicle. It is also lighter and more efficient. Simultaneously, the inclusion of an oil guide structure and oil guide disc 12 ensures better lubrication and higher lubrication reliability during operation.

[0039] According to some embodiments of this application, the housing includes a reducer end housing 7 and a motor end housing 6. The reducer end housing 7 and the motor end housing 6 are joined together by a flange to form the cavity, and both the reducer end housing 7 and the motor end housing 6 have an opening at the end opposite to the joining part.

[0040] The reducer housing in this application is formed by bolting the reducer end housing 7 and the motor end housing 6 together via end flanges. The other end of the motor end housing 6 is used to connect to the motor housing of a new energy vehicle, thus integrating the reducer and motor. Both the reducer end housing 7 and the motor end housing 6 have openings at their ends opposite the docking points. These openings allow for rotational input to the planetary differential assembly (i.e., the motor output inputs power to the planetary gear train through the opening in the motor end housing 6) and also allow for the output of the differential 9.

[0041] According to some embodiments of this application, one end of the planetary carrier differential housing 4 is rotatably supported on the inner wall of the reducer end housing 7 via a bearing 10, and the other end of the planetary carrier differential housing 4 is rotatably supported on the inner wall of the motor end housing 6 via a bearing 10. Specifically, the end of the planetary carrier differential housing 4 near the differential 9 is rotatably connected to the reducer end housing 7 via a bearing 10, and the end of the planetary carrier differential housing 4 near the input end of the planetary gear train (i.e., the end away from the differential 9) is rotatably connected to the motor end housing 6 via another bearing 10. This design also facilitates the installation of the planetary carrier differential assembly.

[0042] According to some embodiments of this application, the planetary gear train includes a sun gear 1 and a double gear 3; the sun gear 1 includes a hollow shaft rotatably supported on the inner wall of the housing, and one end of the hollow shaft is provided with a gear portion extending into the planetary carrier housing 4; three double gears 3 are evenly distributed circumferentially and are rotatably mounted on the planetary carrier housing 4 through planetary step pins 5; the double gear 3 integrates a first-stage gear 31 and a second-stage gear 32, the first-stage gear 31 meshes with the gear portion of the sun gear 1, and the second-stage gear 32 meshes with an internal gear ring 2 fixed on the inner wall of the housing.

[0043] The planetary gear train in this application adopts an NW structure, which has the advantages of compact structure and high transmission ratio, lightweight and cost-effectiveness, high efficiency and low noise. The structure uses a fixed internal gear ring 2 and sun gear 1 as inputs. Three identical double gears 3 are evenly distributed on the planetary carrier differential housing 4 and simultaneously participate in the meshing of sun gear 1 and internal gear ring 2. The three double gears 3 each have their own rotation on the planetary carrier differential housing 4, and at the same time, they revolve around the rotation center of the planetary carrier differential housing 4.

[0044] When the external torsional input causes the sun gear 1 to rotate, the first-stage gear 31 enables the three double gears 3 to rotate synchronously around their own axes. Since the second-stage gear 32 meshes with the internal gear ring 2 fixed on the inner wall of the housing, the three double gears 3 revolve synchronously around the rotation center of the planetary carrier differential housing 4. The planetary carrier differential housing 4 as a whole serves as the power output, thereby driving the differential 9 integrated on the planetary carrier differential housing 4 to work, realizing the wheel end speed difference to adapt to the different turning radii of the vehicle.

[0045] The aforementioned internal gear ring 2 can be fixed to the reducer end housing 7 via a rectangular spline 21. A partially missing rectangular spline 72 is provided on the reducer end housing 7 for mounting the internal gear ring 2. The axial direction of the internal gear ring 2 is limited by a retaining ring 22. The middle part of the sun gear 1's shaft is rotatably mounted on the motor end housing 6 via two bearings 11. One end of the sun gear 1 meshes with three double gears 3 via a gear section, and the other end is connected to the motor output end. Since this reducer is a coaxial design, with the input and output on the same axis, the sun gear 1 is designed as a hollow shaft, through which a half-shaft can be inserted to connect with the differential 9, thereby achieving power output from one side.

[0046] The first-stage gear 31 and the second-stage gear 32 on the double gear 3 are machined as a single piece, and the diameter of the first-stage gear 31 is larger than the diameter of the second-stage gear 32. The first-stage gear 31 and the second-stage gear 32 are arranged coaxially and rotate synchronously. The three double gears 3 are rotatably mounted on the planetary carrier housing 4 through planetary step pins 5, and each rotates around its center.

[0047] The planetary carrier housing 4 is provided with six mounting holes 41 for mounting the planetary step pins 5, which are respectively provided at both ends of the planetary carrier housing 4, with three mounting holes 41 at each end. The mounting holes 41 and the outer circles of the ends of the planetary step pins 5 are interference fit to fix the two ends of the planetary step pins 5.

[0048] According to some embodiments of this application, two needle roller bearings 8 are provided between each of the double gears 3 and the planetary step pin 5. The outer diameter of the part of the planetary step pin 5 that mates with the planetary carrier housing 4 is slightly larger than the outer diameter of the rest of the planetary step pin 5. By providing needle roller bearings 8 between the double gear 3 and the planetary step pin 5, the double gear 3 can rotate smoothly and flexibly. The planetary step pin 5 adopts a stepped shaft structure design, which can prevent surface quality damage during press fitting.

[0049] The aforementioned planetary stepped pin 5 adopts a stepped shaft structure design. Specifically, the outer diameter of one end of the planetary stepped pin 5 is slightly larger than the outer diameter of the rest of the planetary stepped pin 5. At the same time, the inner diameters of the mounting holes 41 at both ends of the planetary carrier housing 4 are designed to be one large and one small, respectively, to ensure that both ends of the planetary stepped pin 5 are interference-fitted with the two mounting holes 41. During installation, the needle roller bearing 8 is first pressed into the double gear 3, and then the entire assembly is inserted through the side window of the planetary carrier housing 4 and aligned with the mounting holes 41. Then, the smaller diameter section of the planetary stepped pin 5 is inserted through the larger mounting hole 41 at one end of the planetary carrier housing 4, passes through the inner ring of the needle roller bearing 8, and is inserted into the opening of the smaller mounting hole 41 at the other end. Finally, pressure is applied to the large end of the planetary stepped pin 5 to press both ends of the planetary stepped pin 5 into the mounting holes 41.

[0050] According to some embodiments of this application, the planetary step pin 5 is a hollow structure, and a radial oil hole 51 communicating with the interior is provided on the outer wall of the planetary step pin 5. The radial oil hole 51 is used to introduce lubricating oil into the needle roller bearing 8. By designing the planetary step pin 5 as a hollow structure and providing radial oil holes 51 on the outer wall, lubricating oil can enter the internal hollow channel from both ends of the planetary step pin 5 when the reducer is working, and then be guided to the needle roller bearing 8 through the radial oil hole 51, thereby forming a good lubrication effect on the needle roller bearing 8 and reducing the friction and wear of the needle roller bearing 8.

[0051] According to some embodiments of this application, two oil guide discs 12 are fixedly provided on the planetary carrier housing 4. The oil guide disc 12 is annular in shape and has an oil guide groove 124 formed by the inner wall being recessed. Three protrusions are evenly distributed circumferentially on one side of the oil guide disc 12. The protrusions extend axially into the interior of the planetary step pin 5, and an oil guide hole 121 is provided at the center of the protrusion. The oil guide hole 121 communicates with the oil guide groove 124 to guide lubricating oil into the interior of the planetary step pin 5.

[0052] In this application, oil guide plates 12 are fixed to both ends of the planetary step pin 5 mounted on the planetary carrier housing 4 using screws 13. The oil guide plates 12 rotate synchronously with the planetary carrier housing 4. The oil guide plates 12 have oil guide grooves 124 to collect lubricating oil. The lubricating oil in the oil guide grooves 124 can then enter the interior of the planetary step pin 5 through the oil guide holes 121, and then be guided to the needle roller bearing 8 through the radial oil holes 51.

[0053] According to some embodiments of this application, the radial radius of the bottom of the oil guide groove 124 gradually decreases from the center of the protrusion to both sides. Since the oil guide plate 12 has three protrusions, three oil guide grooves 124 with a gradually changing structure are evenly arranged in the circumferential direction. By adopting the above structure, when the oil guide plate 12 rotates, the lubricating oil in the oil guide groove 124 can better enter the oil guide hole 121 under the action of centrifugal force.

[0054] Specifically, the oil guide plate 12 has three circumferentially distributed oil guide grooves 124 with gradually increasing bilateral radial radii R1 to R2. The three oil guide grooves 124 are respectively provided with axial oil guide holes 121 at the farthest end R2 of the bottom radius of the grooves. The three oil guide holes 121 are respectively aligned with the inner holes of the three planetary step pins 5 circumferentially distributed on the planetary carrier differential housing 4. Two identical oil guide plates 12 are installed on the end face of the planetary carrier differential housing 4 and revolve together with the planetary carrier differential assembly.

[0055] According to some embodiments of this application, a plurality of oil-stirring ribs 123 are evenly arranged circumferentially on the outer peripheral wall of the oil guide plate 12. Specifically, nine oil-stirring ribs 123 are evenly distributed on the circumference of the oil guide plate 12. When the oil guide plate 12 rotates, the oil-stirring ribs 123 can stir the lubricating oil to the inner wall of the housing.

[0056] This example specifically uses the oil guiding structure on the inner wall of the reducer end housing 7 as an example for illustration.

[0057] According to some embodiments of this application, the oil guiding structure on the inner wall of the housing includes an oil guiding channel 71, which extends towards the rotational support position of the planetary carrier differential housing 4 to guide the lubricating oil splashed onto the inner wall of the housing to the rotational support position of the planetary carrier differential housing 4. The oil guiding channel 71 is disposed on the inner wall of the reducer end housing 7, extending from the mating end to the bearing hole 76, and the portion where the oil guiding channel 71 intersects with the rectangular spline 72 is partially toothed.

[0058] During operation, lubricating oil can splash onto the oil guide channel 71 or onto the inner wall of the housing, and lubricating oil can also enter the oil guide channel 71. Since the angle between the oil guide channel 71 and the horizontal plane is approximately 45° after the reducer is installed, the oil entering the oil guide channel 71 can flow to the bearing hole 76, thereby lubricating the support bearing 10 of the planetary carrier housing 4.

[0059] According to some embodiments of this application, the oil guiding structure on the inner wall of the housing includes an oil drain groove 75 and an oil guiding rib 73. The oil drain groove 75 extends from the rotational support position of the planetary carrier housing 4 to the oil guiding rib 73, which guides the surface lubricating oil into the oil guiding plate 12. The oil drain groove 75 and the oil guiding rib 73 are disposed on the inner wall of the reducer end housing 7, with the oil drain groove 75 extending from the bearing hole 76 to the oil guiding rib 73. The oil guiding rib 73 is a structure of multiple arrayed double-sided oblique ribs, which not only collects the lubricating oil dripping from the inner wall of the housing, but also allows the lubricating oil overflowing from the bearing hole 76 to flow through the oil drain groove 75 to the oil guiding rib 73, which directionally guides the surface lubricating oil into the oil guiding plate 12.

[0060] According to some embodiments of this application, the oil guiding structure on the inner wall of the body includes an oil return groove 74 to allow lubricating oil on the housing to flow into the bottom of the reducer. The oil return groove 74 is disposed on the inner wall of the reducer end housing 7 and is used to allow lubricating oil from the bottom of the reducer end housing 7 to flow into the bottom of the reducer.

[0061] When the planetary carrier differential assembly rotates and agitates the oil at the bottom of the reducer cavity, the oil guide plate 12 rotates synchronously on the planetary carrier differential housing 4, and the oil agitation rib 123 participates in agitation. Under the action of centrifugal force when the oil guide plate 12 rotates, the lubricating oil collected from the inner wall of the reducer end housing 7 and the oil guide rib 73 is thrown into the oil guide hole 121 of the oil guide plate 12 through the oil guide groove 124 with an increased radius from R1 to R2, and the lubricating oil is guided towards the inner hole of the planetary stepped pin 5, and then flows to the needle roller bearing 8 through the radial oil hole 51 to lubricate the needle roller bearings 8 on both sides.

[0062] According to some embodiments of this application, the differential 9 includes planetary gears 91, half-shaft gears 93 and planetary gear shafts 95. There are two half-shaft gears 93 arranged opposite each other along the rotation axis of the planetary carrier differential housing 4. The planetary gear shaft 95 is perpendicular to the rotation axis of the planetary carrier differential housing 4. There are two planetary gears 91 and they are mounted on the planetary gear shaft 95. The two planetary gears 91 mesh with the two half-shaft gears 93.

[0063] Specifically, the aforementioned planetary gears 91 and half-shaft gears 93 are both bevel gears. The planetary carrier differential housing 4 has two mounting spherical surfaces for the planetary gears 91, two mounting surfaces for the half-shaft gears, and two fixing holes for the planetary gear shafts 95. Integrating the differential 9 onto the planetary carrier differential housing 4 reduces the space required.

[0064] During installation, planetary gears 91 and axle gears 93 are inserted into the planetary carrier housing 4 through the side window. The planetary gear shaft 95 is inserted into the two planetary gears 91, and both ends are pressed into the two fixing holes on the planetary carrier housing 4. Then, limit pins 96 are installed to restrict the axial displacement of the planetary gear shaft 95. The axle gear 93 has an internal spline at its center to mate with the external spline on the axle shaft to achieve torque output.

[0065] According to some embodiments of this application, a spherical washer 92 is provided between the planetary gear 91 and the planetary carrier housing 4, and the spherical washer 92 is fitted onto the planetary gear shaft 95. This spherical washer 92 is mainly used to reduce friction between the planetary gear 91 and the planetary carrier housing 4. When a vehicle travels on uneven roads or turns, the speeds of the left and right wheels will differ, and this speed difference will cause friction between the planetary gear 91 and the planetary carrier housing 4. To reduce this friction, the spherical washer 92 is designed in a spherical shape, which can better distribute pressure, avoid direct contact, and thus extend its service life.

[0066] According to some embodiments of this application, a half-shaft washer 94 is provided between the half-shaft gear 93 and the planetary carrier housing 4, and the half-shaft washer 94 is fitted onto the half-shaft gear 93. This half-shaft washer 94 is also intended to reduce friction between the half-shaft gear 93 and the planetary carrier housing 4. It is installed on the back of the half-shaft gear 93 and acts as a buffer between it and the planetary carrier housing 4, reducing wear. The half-shaft washer 94 is typically made of materials such as mild steel, bronze, or nylon, which have good wear resistance and elasticity, providing necessary cushioning when the half-shaft gear 93 rotates.

[0067] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of this utility model. It should be understood that the above description is only a specific embodiment of this utility model and is not intended to limit the scope of protection of this utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A lubrication structure for a coaxial planetary gear reducer, characterized in that, Including the housing and planetary carrier differential assembly; The planetary carrier differential assembly includes a planetary carrier housing, a planetary gear train, and a differential. The planetary carrier housing is rotatably supported within the housing, and the planetary gear train and differential are integrated within the planetary carrier housing. The planetary gear train includes a sun gear and a double gear. Multiple double gears are evenly distributed circumferentially around the sun gear and are rotatably mounted on the planetary carrier housing via planetary step pins and needle roller bearings. The double gear integrates a primary gear and a secondary gear. The primary gear meshes with the sun gear, and the secondary gear meshes with an internal gear ring fixed on the inner wall of the housing. An oil guiding structure is provided on the inner wall of the housing, and an oil guiding disc is provided on the planetary carrier housing. The oil guiding structure guides lubricating oil splashed onto the inner wall of the housing into the oil guiding disc, and the lubricating oil in the oil guiding disc flows to the needle roller bearings.

2. The lubrication structure for the coaxial planetary gear reducer according to claim 1, characterized in that, The oil guide plate is circular in shape and has an inner wall recessed to form an oil guide groove. Multiple protrusions are evenly distributed along the circumference on one side of the oil guide plate. The protrusions extend axially and have an oil guide hole at their center. The oil guide hole is connected to the oil guide groove.

3. The lubrication structure for the coaxial planetary gear reducer according to claim 2, characterized in that, The planetary step pin is a hollow structure, and the protrusion extends into the interior of the planetary step pin. The outer wall of the planetary step pin is provided with a radial oil hole that communicates with the interior, and the radial oil hole introduces lubricating oil into the needle roller bearing.

4. The lubrication structure for the coaxial planetary gear reducer according to claim 2, characterized in that, The radial radius of the bottom of the oil guide groove gradually decreases from the center of the protrusion to both sides.

5. The lubrication structure for the coaxial planetary gear reducer according to claim 1, characterized in that, Multiple oil-stirring ribs are evenly arranged along the circumference on the outer peripheral wall of the oil guide plate.

6. The lubrication structure for the coaxial planetary gear reducer according to claim 1, characterized in that, The oil guiding structure on the inner wall of the housing includes an oil guiding channel that extends toward the rotational support position of the planetary carrier differential housing to guide the lubricating oil splashed onto the inner wall of the housing to the rotational support position of the planetary carrier differential housing.

7. The lubrication structure for the coaxial planetary gear reducer according to claim 6, characterized in that, The oil guiding structure on the inner wall of the housing includes an oil unloading groove and an oil guiding rib. The oil unloading groove extends from the rotation support position of the planetary carrier housing to the oil guiding rib, which can guide the surface lubricating oil into the oil guiding plate.

8. The lubrication structure for the coaxial planetary gear reducer according to claim 7, characterized in that, The oil guiding structure on the inner wall of the housing includes an oil return groove to allow the lubricating oil on the housing to flow into the bottom of the reducer.

9. The lubrication structure for a coaxial planetary gear reducer according to any one of claims 1-8, characterized in that, The housing includes a reducer end housing and a motor end housing, which are connected by a flange. One end of the planetary carrier differential housing is rotatably supported on the inner wall of the reducer end housing by a bearing, and the other end of the planetary carrier differential housing is rotatably supported on the inner wall of the motor end housing by a bearing.

10. The lubrication structure for a coaxial planetary gear reducer according to any one of claims 1-8, characterized in that, The differential includes planetary gears, half-shaft gears, and planetary gear shafts. There are two half-shaft gears arranged opposite each other along the rotation axis of the planetary carrier differential housing. The planetary gear shaft is perpendicular to the rotation axis of the planetary carrier differential housing. There are two planetary gears mounted on the planetary gear shaft. The two planetary gears mesh with the two half-shaft gears. A spherical washer is provided between the planetary gears and the planetary carrier differential housing, and the spherical washer is mounted on the planetary gear shaft. A half-shaft washer is provided between the half-shaft gears and the planetary carrier differential housing, and the half-shaft washer is mounted on the half-shaft gear.

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