A gearbox vent plug assembly with a maze structure

Abstract

The present invention relates to the technical field of gearboxes, and in particular to a gearbox vent plug assembly with a labyrinth structure, which is installed in a connecting hole of a gearbox, and includes a vent plug body, in which a vent hole is provided along its own axial direction; the labyrinth structure includes a plurality of splash plates, each of which is arranged in the vent hole and connected to the vent plug body, and the projection of the plurality of splash plates along the axial direction of the vent plug body covers the vent hole, and an oil-gas gap is formed between adjacent splash plates; an oil-gas filter element is arranged in the vent hole, and is located at one end of the vent plug body away from the inner cavity of the gearbox. The splash plate can block the gear oil or oil foam splashed in the gearbox, and make the gear oil or oil foam flow back to the inside of the gearbox, and the oil-gas filter element reduces the possibility of oil and gas being directly discharged into the atmosphere and causing pollution to the atmosphere, and the oil-gas filter element can also filter the air entering the vent hole from the outside, and reduce the possibility of dust in the air entering the gearbox.

Description

Technical Field

[0001] The invention relates to the technical field of gearboxes, and in particular to a gearbox vent plug assembly with a labyrinth structure. Background Art

[0002] The breather plug is an indispensable part of all types of gearboxes. Its main function is to maintain the air pressure balance inside and outside the gearbox or to make the air pressure inside the gearbox slightly lower than the external air pressure. The situation where the air pressure inside the box is higher than the external air pressure is not allowed. At the same time, a well-designed breather plug can also isolate external atmospheric dust, reduce the entry of external moisture, prevent the oil and gas generated when the gearbox works at high temperature from entering the atmospheric environment, causing environmental pollution, and reducing gear oil loss.

[0003] Existing common breather plugs are mostly integrated structures made of rubber or straight-through structures made of metal. They generally have a protective cap and a body. The body has a straight-through hole to ensure smooth ventilation. However, this straight-through hole is prone to leaking some lubricating oil when the gearbox is running at high speed, causing environmental pollution and lubricating oil loss. The straight-through hole can only ensure basic ventilation and internal and external air pressure balance functions, and cannot effectively isolate dust and moisture, causing the function of the lubricating oil to be reduced or premature failure. Severe cases may also cause early failure of transmission gears or bearings.

[0004] The vent plug assembly currently used in existing products is a straight-through structure made of metal, consisting of a plug body, a plug cap, a spring and a rubber pad. Although the structure is cheap and the cost is low, it cannot effectively prevent splashing gear oil or oil gas from entering the atmosphere. Summary of the invention

[0005] The technical problem to be solved by the present invention is: in order to solve the technical problems in the prior art, the present invention provides a gearbox breather plug assembly with a maze structure, which has low cost, simple assembly, and better effect in preventing oil and gas overflow. It can also effectively block external water vapor and dust from entering the gearbox. Considering the entire life cycle of the product, it can reduce the use cost and improve product quality.

[0006] The technical solution adopted by the present invention to solve its technical problems is: a gearbox breather plug assembly with a labyrinth structure, installed in the connecting hole of the gearbox, comprising a breather plug main body, in which a breather hole is provided along its own axial direction; the labyrinth structure comprises a plurality of splash guards, each of which is arranged in the breather hole and connected to the breather plug main body, at least two splash guards are provided, and the projections of the plurality of splash guards along the axial direction of the breather plug main body cover the breather hole, the plurality of splash guards are staggered along the axial direction of the breather hole, and an oil-gas gap is formed between adjacent splash guards; an oil-gas filter element, the oil-gas filter element is arranged in the breather hole and is located at one end of the breather plug main body away from the inner cavity of the gearbox.

[0007] The present invention provides a gearbox breather plug assembly with a labyrinth structure. When the air pressure inside the gearbox increases, the splashing gear oil or oil foam is blocked by the splash guard, and the gear oil or oil foam is allowed to flow back into the gearbox. Part of the oil and gas passes through the oil-gas gap and is then filtered by the oil-gas filter element as clean air, which is then discharged into the external atmospheric environment, thereby reducing the possibility of oil and gas being directly discharged into the atmospheric environment and causing pollution to the atmospheric environment. At the same time, the oil-gas filter element can also filter the air entering the vent hole from the outside, thereby reducing the possibility of dust in the air entering the gearbox. In addition, the breather plug has a simple main structure and low cost.

[0008] Furthermore, two splash guards are provided, and the projection of each splash guard along the axial direction of the vent hole is semicircular, and the projections of the two splash guards along the axial direction of the vent hole are assembled into a circle.

[0009] Through the above technical solution, two splash guards are provided, which can maximize the connection area between the splash guard and the vent plug body, thereby improving the connection strength between the splash guard and the vent plug body, and at the same time can also reduce the length of the oil-gas gap, thereby reducing the oil and gas passing through the oil-gas gap.

[0010] Furthermore, the splash guard is arranged obliquely, and an end of the splash guard that is not connected to the vent plug body is lower than an end of the splash guard that is connected to the vent plug body.

[0011] Through the above technical solution, after the splash guard is tilted, it can effectively block the gear oil or oil foam, and at the same time, it can utilize the inertial force to make the gear oil and oil foam that hit the bottom of the splash guard fall back into the gearbox faster; in addition, even if some gear oil or oil foam passes through the oil-gas gap and falls onto the splash guard, the tilted splash guard can also facilitate the gear oil or oil foam to slide along the splash guard.

[0012] Furthermore, the projection of one side of each splash plate that is not connected to the vent plug body along the axial direction of the vent hole coincides.

[0013] Through the above technical solution, since the vent plug body is injection molded, the projection of one side of the multiple splash plates that is not connected to the vent plug body along the axial direction of the vent hole overlaps, which can prevent oil and gas from passing through the oil-gas gap as much as possible while ensuring one-time demolding.

[0014] Furthermore, a mounting hole is provided in the vent plug body along its own axial direction, the mounting hole is connected to the vent hole, the diameter of the mounting hole is larger than the diameter of the vent hole, so that a mounting step is formed between the mounting hole and the vent hole, and the oil and gas filter element is placed on the mounting step.

[0015] Through the above technical solution, a mounting hole with a larger diameter can install an oil and gas filter element with a larger size, thereby increasing the filtering area. At the same time, the mounting hole can cooperate with the vent hole to form an installation step, which is convenient for placing the oil and gas filter element and thus facilitates the installation of the oil and gas filter element.

[0016] Furthermore, the installation step is arranged at an inclination, and the oil and gas filter element is adapted to the installation step.

[0017] Through the above technical scheme, the installation step is inclined, which can better realize the transition between the vent hole and the installation hole, and can also better cooperate with the oil and gas filter element, reducing the possibility of oil and gas passing through the gap between the oil and gas filter element and the installation hole; in addition, after the gear oil filtered by the oil and gas filter element accumulates, it can slide down the inclined surface into the vent hole under the action of gravity, and then slide back into the gearbox along the splash plate.

[0018] Furthermore, a mounting portion is provided on the vent plug body, a cover cap is sleeved on the mounting portion, a mounting ring is provided on the vent plug body, a flange is provided on the cover cap, and the flange abuts against an end of the mounting ring away from the mounting portion.

[0019] Through the above technical solution, the vent plug body is protected by the cover cap, reducing the possibility of external dust and air entering the vent hole.

[0020] Furthermore, a gasket is provided between the cover cap and the mounting portion, and the gasket covers the mounting hole along the axial direction of the vent hole.

[0021] Through the above technical solution, after the oil and gas are filtered into clean air by the oil and gas filter element, the clean air pushes open the gasket and is discharged into the external atmospheric environment through the gap between the gasket and the mounting part; and when the temperature inside the gearbox drops, the internal pressure also begins to drop, and the gasket falls back to the mounting part by its own gravity, preventing outside air from entering the interior of the gearbox.

[0022] Furthermore, a limiting portion is provided on the vent plug body, and the limiting portion is used to abut against the outer shell of the gearbox. A connecting portion is provided at one end of the vent plug body away from the mounting portion, and multiple connecting portions are provided along the circumference of the vent plug body. A hook portion is provided at one end of the connecting portion away from the limiting portion, and the connecting portion is used to extend into the gearbox and make the hook abut against the inner wall of the gearbox; a sealing ring is sleeved on the vent plug body, and the sealing ring abuts against the gearbox outer shell and the limiting portion at the same time.

[0023] Through the above technical solution, the hook portion cooperates with the limiting portion to fix the vent plug body on the gearbox, and the sealing ring is used to achieve sealing between the vent plug body and the gearbox. The reaction force generated when the sealing ring is squeezed can cause the hook portion to abut against the inner wall of the gearbox reliably, thereby reducing the possibility of looseness between the vent plug body and the gearbox.

[0024] Furthermore, the hook portion is provided with a first arc surface and a second arc surface, the first arc surface is provided on a side of the hook portion away from the limiting portion, so that when the connecting portion is inserted into the connecting hole of the gearbox, the connecting portion is deformed so that the hook portion is pressed into the connecting hole; the second arc surface is provided at an end of the hook portion close to the limiting portion, so that when the vent plug body is pulled in a direction away from the gearbox, the connecting portion is deformed so that the hook portion enters the connecting hole.

[0025] Through the above technical solution, when installing the vent plug body, when the hook is inserted into the connecting hole of the gearbox, the first arc surface abuts against the side wall of the connecting hole, prompting the connecting part to bend and deform toward the axis of the vent hole, so that the hook enters the connecting port; after the hook passes through the connecting hole, the connecting part resets by its own elasticity, so that the hook swings in the direction away from the axis of the vent hole, thereby making the hook abut against the inner wall of the gearbox, and at this time, the limiting part also abuts against the outer wall of the gearbox, thereby realizing the rapid installation of the vent plug body; when disassembling the vent plug body, the vent plug body is pulled in the direction away from the gearbox, so that the second arc surface abuts against the inner wall of the gearbox connecting hole, prompting the connecting part to bend and deform toward the axis of the vent hole, so that the hook enters the connecting hole; when the hook is separated from the connecting hole, the connecting part resets by its own elasticity, thereby realizing the rapid disassembly of the vent plug body.

[0026] The beneficial effects of the present invention are:

[0027] 1. When the air pressure inside the gearbox increases, the splash plate blocks the splashing gear oil or oil foam, and allows the gear oil or oil foam to flow back into the gearbox. Part of the oil and gas passes through the oil-gas gap and is then filtered into clean air by the oil-gas filter element. The clean air pushes the gasket open and is discharged into the external atmosphere through the gap between the gasket and the mounting part, reducing the possibility of oil and gas being directly discharged into the atmosphere and causing pollution to the atmosphere. Thereafter, the gasket falls back to the mounting part by its own gravity, preventing outside air from entering the gearbox. When the gasket falls back, a small amount of air will enter the mounting hole, and the oil-gas filter element will filter the air entering from the outside, reducing the possibility of dust in the air entering the gearbox. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0029] Figure 1 The present invention is a schematic cross-sectional structure diagram of a transmission vent plug assembly with a labyrinth structure.

[0030] Figure 2 The diagram is a schematic diagram of an exploded structure of a transmission vent plug assembly with a labyrinth structure according to the present invention.

[0031] Figure 3It is a top view schematic diagram showing that the splash guard plates are arranged in a circle along the axial direction of the vent holes in the present invention.

[0032] Figure 4 It is a schematic diagram of the vent plug body in the present invention.

[0033] Figure 5 It is a schematic diagram of an oil and gas filter element in the present invention.

[0034] Figure 6 It is a schematic diagram of a cap embodying the present invention.

[0035] Figure 7 It is a schematic exploded view of the entire mold for the vent plug in the present invention.

[0036] Figure 8 It is a schematic cross-sectional view of a mold for a vent plug according to the present invention.

[0037] Fig. 9 It is a schematic diagram of the lower mold in the present invention.

[0038] Fig.10 It is a schematic diagram of the upper mold in the present invention.

[0039] In the figure: 1. Vent plug body; 11. Mounting hole; 12. Vent hole; 13. Splash plate; 131. Oil-gas gap; 14. Oil-gas filter element; 141. Anti-blocking hole; 15. Mounting step; 16. Mounting part; 161. Mounting ring; 162. Pad hole; 163. Limiting step; 164. Vent groove; 17. Limiting part; 18. Connecting part; 19. Hook; 191. First arc surface; 192. Second arc surface; 2. Cap; 21. Gasket; 22. Flange; 221. Mounting fillet; 23. Sealing ring; 3. Gearbox; 31. Connecting hole; 4. Upper mold; 41, pad hole molding column; 411, guide rod; 42, ventilation molding column; 43, third inclined surface; 44, fourth inclined surface; 45, second step surface; 46, installation molding column; 47, ventilation molding block; 48, injection groove; 49, injection hole; 5, lower mold; 51, lower molding column; 52, first inclined surface; 53, second inclined surface; 54, first step surface; 55, connection molding block; 56, connection molding groove; 6, left mold; 61, first installation molding groove; 62, second installation molding groove; 63, limit molding groove; 64, hook molding groove; 7, right mold. DETAILED DESCRIPTION

[0040] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0041] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more. In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be a connection between the two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] The invention discloses a gearbox vent plug assembly with a labyrinth structure.

[0043] Reference Figure 1 and Figure 2 , a gearbox vent plug assembly with a labyrinth structure is installed in a connecting hole 31 provided on a gearbox 3. The vent plug assembly includes a vent plug body 1, in which a mounting hole 11 and a vent hole 12 are provided along the axial direction of the vent plug body 1, and the mounting hole 11 and the vent hole 12 are coaxial and interconnected. A labyrinth structure and an oil-gas filter element 14 are provided in the vent plug body 1, and the labyrinth structure includes a plurality of splash plates 13, each of which is provided in the vent hole 12 and connected to the vent plug body 1, and at least two splash plates 13 are provided, and the plurality of splash plates 13 cover the vent hole 12 along the axial projection of the vent plug body 1, so as to block the gear oil or gear foam splashed in the gearbox 3. The plurality of splash plates 13 are staggered along the axial direction of the vent hole 12, and an oil-gas gap 131 is formed between adjacent splash plates 13 to facilitate the passage of oil and gas. In this embodiment, the height of the oil-gas gap 131 is 2 to 4 mm, which can reduce the possibility of gear oil passing through the oil-gas gap 131 and allow a certain flow of oil and gas to pass through to achieve ventilation. A portion of the oil-gas filter element 14 is located in the vent hole 12, and the other portion is located in the mounting hole 11. The oil-gas filter element 14 is located at one end of the vent plug body 1 away from the inner cavity of the gearbox 3, so that the oil and gas first pass through the oil-gas gap 131 and then are filtered by the oil-gas filter element 14.

[0044] When the air pressure inside the gearbox 3 increases, the splashing gear oil or oil foam can be blocked by the splash plate 13, and the gear oil or oil foam can flow back to the inside of the gearbox 3. Part of the oil and gas passes through the oil-gas gap 131, and is then filtered into clean air by the oil-gas filter element 14 and then discharged into the external atmospheric environment, thereby reducing the possibility of oil and gas being directly discharged into the atmospheric environment and causing pollution to the atmospheric environment. At the same time, the oil-gas filter element 14 can also filter the air entering the vent 12 from the outside, thereby reducing the possibility of dust in the air entering the gearbox 3.

[0045] Specifically, refer to Figure 1 and Figure 3 In this embodiment, two splash plates 13 are provided, and the projection of each splash plate 13 along the axial direction of the vent hole 12 is semicircular, and the projections of the two splash plates 13 along the axial direction of the vent hole are assembled into a circle, and the arc surfaces of the two splash plates 13 are connected to the vent plug body 1 to maximize the connection area between the splash plate 13 and the vent plug body 1, thereby improving the connection strength between the splash plate 13 and the vent plug body 1, and at the same time, it can also reduce the length of the oil-gas gap 131, thereby reducing the oil and gas passing through the oil-gas gap 131. In another embodiment, three splash plates 13 can also be provided, and the projection of each splash plate 13 along the axial direction of the vent hole 12 is fan-shaped, and the central angle is 120 degrees.

[0046] More specifically, the splash plate 13 is tilted, and the splash plate 13 has two tilting modes, namely mode A and mode B. Mode A is that the end of the splash plate 13 close to the axis of the vent 12 is lower than the end of the splash plate 13 away from the axis of the vent 12, and mode B is that the end of the splash plate 13 close to the axis of the vent 12 is higher than the end of the splash plate 13 away from the axis of the vent 12. Mode A is preferred in this embodiment. After the splash plate 13 is tilted, it can effectively block the gear oil or oil foam. At the same time, compared with mode B, mode A can use inertial force to make the gear oil and oil foam that hit the bottom of the splash plate 13 fall back to the inside of the gearbox 3 faster. If mode B is adopted, when the gear oil or oil foam hits the splash plate 13, it may flow along the splash plate 13 toward the oil-gas gap 131. In addition, even if some gear oil or oil foam passes through the oil-gas gap 131 and falls on the splash plate 13 , the inclined splash plate 13 can facilitate the gear oil or oil foam to slide down along the splash plate 13 .

[0047] It should be noted that the angle between the splash plate 13 and the axis of the vent hole 12 is 30 to 60 degrees, preferably 45 degrees.

[0048] In addition, refer to Figure 1, the projection of one side of each splash plate 13 that is not connected to the vent plug body 1 along the axial direction of the vent hole 12 coincides, that is, the projection of one side of each splash plate 13 that is not connected to the vent plug body 1 is passed through by the axis of the vent hole 12. Since the vent plug body 1 is injection molded, the projections of one side of multiple splash plates 13 that are not connected to the vent plug body 1 along the axial direction of the vent hole 12 coincide, which can increase the path length of the oil and gas passing through the oil-gas gap 131 while ensuring one-time demolding, and hinder the oil and gas from passing through the oil-gas gap 131 as much as possible. If the side of the splash plate 13 that is not connected to the vent plug body 1 is made to cross the axis of the vent hole 12, it is certainly possible to increase the path length of the oil and gas passing through the oil-gas gap 131, but it will greatly increase the complexity and cost of the mold.

[0049] According to the gearbox breather plug assembly with a labyrinth structure of this embodiment, the diameter of the mounting hole 11 is larger than the diameter of the breather hole 12, so that a mounting step 15 is formed between the mounting hole 11 and the breather hole 12, and the oil and gas filter element 14 is placed on the mounting step 15. The mounting hole 11 with a larger diameter can be used to install a larger oil and gas filter element 14, thereby increasing the filtering area. At the same time, the mounting hole 11 can cooperate with the breather hole 12 to form the mounting step 15, which is convenient for placing the oil and gas filter element 14, thereby facilitating the installation of the oil and gas filter element 14.

[0050] Specifically, the mounting step 15 is arranged at an angle, and the oil and gas filter element 14 is provided with an inclined portion that matches the mounting step 15. The angle between the mounting step 15 and the axis of the vent hole 12 is 50 to 80 degrees, and 50 degrees is preferred in this embodiment. After the mounting step 15 is arranged at an angle, the transition between the vent hole 12 and the mounting hole 11 can be better achieved, and the oil and gas filter element 14 can be better matched, reducing the possibility of oil and gas passing through the gap between the oil and gas filter element 14 and the mounting hole 11.

[0051] It should be noted that, refer to Figure 5 The oil and gas filter element 14 has a porous structure and can be made of mesh cotton filaments, which can separate the gear oil in the oil and gas. After the gear oil condenses, it flows into the vent hole 12 along the inclined mounting step 15, then falls on the inclined splash plate 13, and falls back into the gearbox 3 along the inclined splash plate 13. If the mounting step 15 is arranged perpendicular to the axis of the mounting hole 11, the gear oil separated in the oil and gas filter element 14 may be partially retained on the mounting step 15.

[0052] Anti-blocking holes 141 are also provided on the oil and gas filter element 14 along its own axial direction, and the anti-blocking holes 141 are arranged in a circumferential array along the oil and gas filter element 14. The anti-blocking holes 141 are arranged along the axial direction of the oil and gas filter element 14 and penetrate the inclined portion, that is, after the oil and gas filter element 14 is installed, one end of the anti-blocking hole 141 coincides with the installation step 15, which can reduce the possibility of oil and gas passing directly through the anti-blocking hole 141. When the oil and gas filter element 14 is blocked, the anti-blocking holes 141 can allow gas to pass through, reducing the possibility of the vent plug body 1 being blocked due to the blockage of the oil and gas filter element 14.

[0053] According to the gearbox vent plug assembly with a labyrinth structure of this embodiment, refer to Figure 4 and Figure 6 The vent plug body 1 is integrally formed with a mounting portion 16, and the vent plug body 1 is also integrally formed with a mounting ring 161, and the diameters of the mounting portion 16 and the mounting ring 161 are both larger than the diameter of the vent plug body 1. A cap 2 is sleeved on the mounting portion 16, and a flange 22 is integrally formed on the inner wall of the cap 2, and the flange 22 abuts against an end of the mounting ring 161 away from the mounting portion 16, so that the cap 2 is fixed to the vent plug body 1. The vent plug body 1 is protected by the cap 2, which can reduce the possibility of external dust and air entering the vent hole 12. The flange 22 is provided with a mounting fillet 221. When the cap 2 is installed, the mounting fillet 221 first contacts the mounting ring 161, causing the flange 22 and the side wall of the cap 2 to deform, so that the cap 2 can be sleeved on the mounting portion 16. When the cap 2 abuts against the end surface of the mounting portion 16, the flange 22 is reset by its own elasticity and abuts against the end of the mounting ring 161 away from the mounting portion 16, so that the cap 2 is fixed to the vent plug body 1. When the cap 2 needs to be removed, the flange 22 can also be deformed by relying on the mounting fillet 221 to separate the cap 2 from the vent plug body 1.

[0054] Furthermore, the mounting portion 16 is provided with a gasket hole 162, in which a gasket 21 is provided, the gasket hole 162 is communicated with the mounting hole 11, the diameter of the gasket hole 162 is larger than the diameter of the mounting hole 11, and a limiting step 163 is formed between the gasket hole 162 and the mounting hole 11 to place the gasket 21, and the gasket 21 covers the mounting hole 11 along the axial direction of the vent hole 12. A vent groove 164 is provided on the side wall of the mounting portion 16, and there are multiple vent grooves 164 arranged in a circumferential array along the mounting portion 16, and in this embodiment, there are 4 vent grooves. When the oil and gas are filtered into clean air by the oil and gas filter element 14, the clean air pushes open the gasket 21, passes through the gap between the gasket 21 and the limiting step 163, passes through the ventilation groove 164, and then passes through the gap between the cap 2 and the side wall of the mounting portion 16, and is discharged into the external atmospheric environment; and when the temperature inside the gearbox 3 drops, the internal pressure also begins to drop, and the gasket 21 falls back onto the limiting step 163 by its own gravity, preventing external air from entering the interior of the gearbox 3.

[0055] It should be noted that the thickness of the gasket 21 is slightly smaller than the height of the gasket hole 162. In the present embodiment, the thickness of the gasket 21 is 0.5 to 2 mm smaller than the height of the gasket hole 162, which can ensure that the oil and gas can pass through the gap between the gasket 21 and the limiting step 163, and the oil and gas flow through the gap between the gasket 21 and the limiting step 163 is within a controllable range. At the same time, it can also ensure that the gasket 21 can fall back onto the limiting step 163 by its own gravity after the internal pressure of the gearbox 3 is reduced.

[0056] Specifically, refer to Figure 1 and Figure 4 The vent plug body 1 is integrally formed with a limiting portion 17, which is used to abut against the outer shell of the gearbox 3. A connecting portion 18 is provided at one end of the vent plug body 1 away from the mounting portion 16. The connecting portion 18 is provided in multiple numbers along the circumference of the vent plug body 1. A hook portion 19 is provided at one end of the connecting portion 18 away from the limiting portion 17. The connecting portion 18 is used to extend into the gearbox 3 and make the hook portion 19 abut against the inner wall of the gearbox 3. A sealing ring 23 is sleeved on the vent plug body 1, and the sealing ring 23 abuts against the outer shell of the gearbox 3 and the limiting portion 17 at the same time. The hook portion 19 cooperates with the limiting portion 17 to fix the vent plug body 1 on the gearbox 3, and the sealing ring 23 is used to achieve the sealing between the vent plug body 1 and the gearbox 3. The reaction force generated when the sealing ring 23 is squeezed can make the hook portion 19 abut against the inner wall of the gearbox 3 reliably, reducing the possibility of loosening between the vent plug body 1 and the gearbox 3. The sealing ring 23 can be made of rubber.

[0057] More specifically, the hook portion 19 is provided with a first arc surface 191 and a second arc surface 192. The first arc surface 191 is provided on the side of the hook portion 19 away from the limiting portion 17, so that when the connecting portion 18 is inserted into the connecting hole 31 of the gearbox 3, the connecting portion 18 is deformed so that the hook portion 19 is pressed into the connecting hole 31; the second arc surface 192 is provided at one end of the hook portion 19 close to the limiting portion 17, so that when the vent plug body 1 is pulled in a direction away from the gearbox 3, the connecting portion 18 is deformed so that the hook portion 19 enters the connecting hole 31.

[0058] When installing the vent plug body 1, when the hook 19 is inserted into the connecting hole 31 of the gearbox 3, the first arc surface 191 abuts against the side wall of the connecting hole 31, prompting the connecting portion 18 to bend and deform toward the axis of the vent hole 12, so that the hook 19 enters the connecting port. After the hook 19 passes through the connecting hole 31, the connecting portion 18 is reset by its own elasticity, so that the hook 19 swings in the direction away from the axis of the vent hole 12, thereby making the hook 19 abut against the inner wall of the gearbox 3, and the limiting portion 17 also abuts against the outer wall of the gearbox 3 at this time, thereby realizing the rapid installation of the vent plug body 1; when disassembling the vent plug body 1, the vent plug body 1 is pulled in the direction away from the gearbox 3, so that the second arc surface 192 abuts against the inner wall of the connecting hole 31 of the gearbox 3, prompting the connecting portion 18 to bend and deform toward the axis of the vent hole 12, so that the hook 19 enters the connecting hole 31. When the hook 19 is separated from the connecting hole 31, the connecting portion 18 is reset by its own elasticity, thereby realizing the rapid disassembly of the vent plug body 1.

[0059] It should be noted that, in this embodiment, the vent plug body 1 and the cover cap 2 are both made of engineering plastics, so that the connecting portion 18, the flange 22 and the cover cap 2 can all undergo a certain degree of elastic deformation.

[0060] Working principle: When the air pressure inside the gearbox 3 increases, the splash plate 13 blocks the splashing gear oil or oil foam, and allows the gear oil or oil foam to flow back to the gearbox 3. Part of the oil and gas passes through the oil-gas gap 131, and is then filtered into clean air by the oil-gas filter element 14. The clean air pushes the gasket 21, passes through the gap between the gasket 21 and the limiting step 163, passes through the ventilation groove 164, and then passes through the gap between the cap 2 and the side wall of the mounting portion 16, and is discharged into the external atmosphere, reducing the possibility of oil and gas being directly discharged into the atmosphere and causing pollution to the atmosphere. Thereafter, the gasket 21 falls back onto the mounting portion 16 by its own gravity, preventing the outside air from entering the gearbox 3. When the gasket 21 falls back, a small amount of air will enter the mounting hole 11, and the oil-gas filter element 14 filters the air entering from the outside, reducing the possibility of dust in the air entering the gearbox 3. The oil-gas filter 14 can also separate the gear oil in the oil and gas, and the gear oil condenses and flows into the vent 12 along the inclined mounting step 15, then falls on the inclined splash plate 13, and falls back into the gearbox 3 along the inclined splash plate 13. If the mounting step 15 is arranged perpendicular to the axis of the mounting hole 11, the gear oil separated in the oil-gas filter 14 may be partially retained on the mounting step 15.

[0061] A mold for a vent plug, based on the above-mentioned gearbox vent plug assembly with a maze structure, is used for injection molding a vent plug body 1. Figures 7 to 10The mold for the vent plug includes an upper mold 4, a lower mold 5, a left mold 6 and a right mold 7. After the upper mold 4, the lower mold 5, the left mold 6 and the right mold 7 are spliced, a cavity for molding the vent plug body 1 is formed.

[0062] Specifically, the lower molding column 51 is fixedly connected to the lower mold 5 so as to mold the lower half of the vent hole 12. The top of the lower molding column 51 is provided with a first inclined surface 52, a second inclined surface 53 and a first step surface 54. The first inclined surface 52 and the second inclined surface 53 are used to mold the bottom of the two splash plates 13, and the first step surface 54 is used to mold the end surface of the splash plate 13 located below. The side wall of the lower molding column 51 is also fixedly connected with a connection molding block 55. There are a plurality of connection molding blocks 55 arranged along the circumferential array of the lower molding column 51. A connection molding groove 56 is formed between adjacent connection molding blocks 55 for molding the connection portion 18.

[0063] The left mold 6 has the same structure as the right mold 7, and the left mold 6 is used as an example for description. The left mold 6 is provided with a first installation molding groove 61, a second installation molding groove 62, a limit molding groove 63 and a hook molding groove 64 from top to bottom, which are used to form the installation part 16, the installation ring 161, the limit part 17 and the hook part 19 respectively.

[0064] A pad hole forming column 41 is provided below the upper mold 4 for forming the pad hole 162; a mounting forming column 46 is fixedly connected to the bottom surface of the pad hole forming column 41 for forming the mounting hole 11; a vent forming column 42 is fixedly connected to the bottom surface of the mounting forming column 46 for forming the upper half of the vent hole 12. A third inclined surface 43, a fourth inclined surface 44 and a second step surface 45 are provided on the bottom surface of the vent forming column 42. The third inclined surface 43 and the fourth inclined surface 44 are used to form the tops of the two splash guards 13, and the second step surface 45 is used to form the end surface of the splash guard 13 located above. When the upper mold 4 and the lower mold 5 are molded together, the first step surface 54 and the second step surface 45 partially overlap, and the portion where the first step surface 54 and the second step surface 45 overlap is the height of the oil-gas gap 131, that is, the height of the oil-gas gap 131 can be fine-tuned by adjusting the distance between the upper mold 4 and the lower mold 5 when the mold is closed. A ventilation molding block 47 is fixedly connected to the side wall of the pad hole molding column 41 . There are multiple ventilation molding blocks arranged in a circumferential array along the pad hole molding column 41 for forming the ventilation groove 164 . An injection molding groove 48 is formed between adjacent ventilation molding blocks 47 .

[0065] The top of the hole forming column 41 is fixedly connected with a guide rod 411, and the upper mold 4 is sleeved on the guide rod 411, so that when the mold is closed, the upper mold 4 always abuts against the top surface of the left mold 6 and the right mold 7. When the upper mold 4 is moved, power can be directly applied to the guide rod 411.

[0066] In addition, an injection hole 49 is provided on the upper mold 4 . When the mold is closed, the injection hole 49 is located above the injection groove 48 .

[0067] During operation, the left mold 6 and the right mold 7 are first closed on the lower mold 5, and then the upper mold 4 is closed on the lower mold 5, and then injection molding is performed through the injection hole 49. After the vent plug body 1 is formed, the upper mold 4 is separated first, and then the left mold 6 and the right mold 7 are separated, and finally the vent plug body 1 is removed from the lower mold 5. The left mold 6, the right mold 7 and the upper mold 4 can be molded and separated in batches, that is, a plurality of left molds 6, a plurality of right molds 7 and a plurality of upper molds 4 can be driven by a cylinder respectively. The vent plug body 1 can be removed from the lower mold 5 by a manipulator.

[0068] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A mold for a vent plug, used for producing a vent plug, the vent plug being installed in a connecting hole (31) of a gearbox (3), the vent plug comprising a vent plug body (1), a labyrinth mechanism and an oil and gas filter element (14), the vent plug body (1) being provided with a vent hole (12) along its own axial direction; the labyrinth mechanism comprising a plurality of splash plates (13), each of the splash plates (13) being arranged in the vent hole (12) and connected to the vent plug body (1), the splash plates (13) being provided with at least two, the plurality of splash plates (13) covering the vent hole (12) along the axial projection of the vent plug body (1), the plurality of splash plates (13) being staggered along the axial direction of the vent hole (12), the adjacent splash plates (13) being arranged at a distance from each other. An oil-gas gap (131) is formed between the two sides of the vent plug body (12); the oil-gas filter element (14) is arranged in the vent hole (12) and is located at the end of the vent plug body (1) away from the inner cavity of the gearbox (3); two splash guards (13) are provided, and the projection of each splash guard (13) along the axial direction of the vent hole (12) is semicircular, and the projections of the two splash guards (13) along the axial direction of the vent hole form a circle; the splash guards (13) are arranged obliquely, and the end of the splash guard (13) not connected to the vent plug body (1) is lower than the end of the splash guard (13) connected to the vent plug body (1); the projection of one side of each splash guard (13) not connected to the vent plug body (1) along the axial direction of the vent hole (12) coincides; the inner side of the vent plug body (1) is A mounting hole (11) is axially provided, the mounting hole (11) is communicated with the vent hole (12), the diameter of the mounting hole (11) is larger than the diameter of the vent hole (12), so that a mounting step (15) is formed between the mounting hole (11) and the vent hole (12), and the oil and gas filter element (14) is placed on the mounting step (15); the mounting step (15) is inclined, and the oil and gas filter element (14) and the mounting step (15) are adapted; a mounting portion (16) is provided on the vent plug body (1), a cover cap (2) is sleeved on the mounting portion (16), a mounting ring (161) is provided on the vent plug body (1), a flange (22) is provided on the cover cap (2), and the flange (22) and the mounting ring (161) are connected to each other. an end away from the mounting portion (16) abuts against the end thereof; a gasket (21) is provided between the cover cap (2) and the mounting portion (16), and the gasket (21) covers the mounting hole (11) along the axial direction of the vent hole (12); a limiting portion (17) is provided on the vent plug body (1), and the limiting portion (17) is used to abut against the outer shell of the gearbox (3); an end of the vent plug body (1) away from the mounting portion (16) is provided with a connecting portion (18), and a plurality of connecting portions (18) are provided along the circumference of the vent plug body (1); an end of the connecting portion (18) away from the limiting portion (17) is provided with a hook portion (19), and the connecting portion (18) is used to extend into the gearbox (3) and make the hook portion (19) abut against the inner wall of the gearbox (3);The vent plug body (1) is sleeved with a sealing ring (23), and the sealing ring (23) is in contact with the outer shell of the gearbox (3) and the limiting portion (17) at the same time; the hook portion (19) is provided with a first arc surface (191) and a second arc surface (192); the first arc surface (191) is provided on a side of the hook portion (19) away from the limiting portion (17), so that when the connecting portion (18) is inserted into the connecting hole (31) of the gearbox (3), the connecting portion (18) is deformed so that the hook portion (19) is pressed into the connecting hole (31); the second arc surface (192) is provided at one end of the hook portion (19) close to the limiting portion (17), so that when the vent plug body (1) is pulled in a direction away from the gearbox (3), The connecting portion (18) is deformed so that the hook portion (19) enters the connecting hole (31); an anti-blocking hole (141) is also provided on the oil and gas filter element (14) along its own axial direction, and the anti-blocking holes (141) are arranged in a circumferential array along the oil and gas filter element (14). The anti-blocking holes (141) are arranged along the axial direction of the oil and gas filter element (14) and penetrate the inclined portion, that is, after the oil and gas filter element (14) is installed, one end of the anti-blocking hole (141) coincides with the installation step (15), which can reduce the possibility of oil and gas directly passing through the anti-blocking hole (141). When the oil and gas filter element (14) is blocked, the anti-blocking hole (141) can allow gas to pass through, thereby reducing the possibility of the vent plug body (1) being blocked due to the blockage of the oil and gas filter element (14); it is characterized in that; The mold for the vent plug comprises an upper mold (4), a lower mold (5), a left mold (6) and a right mold (7). After the upper mold (4), the lower mold (5), the left mold (6) and the right mold (7) are spliced ​​together, a mold cavity for molding a vent plug body (1) is formed; a lower molding column (51) is fixedly connected to the lower mold (5) so as to mold the lower half of the vent hole (12); the top of the lower molding column (51) is provided with a first inclined surface (52), a second inclined surface (53) and a first step surface (54); the first inclined surface (52) and the second inclined surface (53) are used to mold the bottom of two splash guards (13); the first step surface (54) is used to mold the end surface of the splash guard (13) located below; the side wall of the lower molding column (51) is also fixedly connected to a lower molding column (51) The left mold (6) is provided with a connecting molding block (55), wherein the connecting molding blocks (55) are arranged in a circumferential array along the lower molding column (51), and connecting molding grooves (56) are formed between adjacent connecting molding blocks (55) for molding the connecting portion (18); the left mold (6) is provided with a first installation molding groove (61), a second installation molding groove (62), a limit molding groove (63) and a hook portion (19) molding groove in sequence from top to bottom, which are respectively used to mold the installation portion (16), the installation ring (161), the limit portion (17) and the hook portion (19); a pad hole (162) molding column is provided below the upper mold (4) for molding the pad hole (162); a mounting molding column (46) is fixedly connected to the bottom surface of the pad hole (162) molding column for molding The mounting hole (11) is fixedly connected to the bottom surface of the mounting molding column (46) with a ventilation molding column (42) for molding the upper half of the ventilation hole (12); the bottom surface of the ventilation molding column (42) is provided with a third inclined surface (43), a fourth inclined surface (44) and a second step surface (45); the third inclined surface (43) and the fourth inclined surface (44) are used to mold the tops of the two splash guards (13); the second step surface (45) is used to mold the end surface of the splash guard (13) located above; when the upper mold (4) and the lower mold (5) are molded together, the first step surface (54) and the second step surface (45) partially overlap, and the portion where the first step surface (54) and the second step surface (45) overlap is the height of the oil-gas gap (131). The invention relates to a method for forming a gas-oil gap (131) with a gasket hole (162) and a gasket molded column. The gasket hole (162) has a plurality of gas-ventilated blocks (47) arranged along the circumferential direction of the gasket hole (162) and used for forming a gasket groove (164). An injection molding groove (48) is formed between adjacent gas-ventilated blocks (47). The top of the gasket hole (162) is fixedly connected to a guide rod (411). The upper mold (4) is sleeved on the guide rod (411) so that when the mold is closed, the upper mold (4) always contacts the top surface of the left mold (6) and the right mold (7). The structure of the right mold (7) is the same as that of the left mold (6).

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