A drive bridge for a normally closed vent plug

Abstract

The utility model discloses a kind of drive axle of normally closed vent plug, belong to vehicle drive axle technical field, including axle housing, the vent is provided on the axle housing, the vent is equipped with normally closed vent plug;The normally closed vent plug includes plug body and plug cap: the plug body is connected with the vent thread, the plug body inside is equipped with vent passage, vent passage is communicated with the inner chamber of the axle housing, the inside of the plug cap is equipped with valve piece, cover piece and spring in proper order, valve piece covers the export of vent passage, cover piece is located valve piece outside, spring one end leans on cover piece, the other end leans on the inner wall of plug cap.The utility model is by being arranged in the vent of drive axle one-way exhaust structure by valve piece, spring and cover piece, make vent plug keep closed state under normality, only when axle housing internal air pressure rises, it is opened exhaust automatically, to prevent external air, water and dust into axle housing interior, guarantee the cleanliness and lubricating property of gear oil.

Description

Technical Field

[0001] This utility model belongs to the field of vehicle drive axle technology, and particularly relates to a drive axle with a normally closed vent plug. Background Technology

[0002] The drive axle is a key component of a vehicle's transmission system. It houses the final drive, differential, and half-shafts, and is filled with lubricating oil to lubricate and cool the gears and bearings. Because the drive axle is a sealed cavity, the high-speed rotation of the gears during vehicle operation causes the cavity temperature to rise, increasing the internal air pressure. To balance the pressure difference between the inside and outside, vents and vent plugs are typically installed on the axle housing to allow internal gases to escape.

[0003] like Figure 1 Existing drive axles mostly use a "vent plug + external long pipe" method for exhaust. When the vehicle is wading through water or in a muddy environment, external water and mud can easily flow back into the axle housing along the pipe, causing gear oil contamination and leading to premature failure of parts such as gears, bearings and oil seals.

[0004] Therefore, there is an urgent need for a normally closed ventilation device with a simpler structure that can prevent backflow of external water and dust, in order to improve the reliability and service life of the drive axle. Utility Model Content

[0005] The purpose of this invention is to provide a drive axle with a normally closed vent plug to solve the technical problems of external water and dust backflow and gear oil contamination in the venting structure of the drive axle mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: A drive axle with a normally closed vent plug includes an axle housing, on which a vent is provided, and a normally closed vent plug is installed at the vent; the normally closed vent plug includes a plug body and a plug cap. The plug body is threadedly connected to the vent. The plug body has a venting channel inside, which communicates with the inner cavity of the bridge housing. The plug cap has a valve plate, a cover plate, and a spring arranged in sequence inside. The valve plate covers the outlet of the venting channel, the cover plate is located outside the valve plate, one end of the spring abuts against the cover plate, and the other end abuts against the inner wall of the plug cap, which is used to apply pressure to the valve plate, so that the valve plate fits against the end face of the plug body to close the venting channel. When the air pressure inside the bridge housing exceeds the spring pressure, the valve plate and the cover plate are pushed open to release the gas.

[0007] Preferably, the outer circumference of the plug body is tapered thread, and the vent is provided with an internal tapered thread that matches it; this enhances the sealing performance and prevents leakage at the vent.

[0008] Preferably, the vent plug is installed at the upper end of the bridge housing; this keeps the vent away from the oil surface and the mud and water splash area, further reducing the risk of water ingress.

[0009] Preferably, the valve plate is made of an elastic sealing material; maintaining good resilience and sealing performance.

[0010] Preferably, the valve plate and the end face of the plug are detachably connected; this facilitates replacement or maintenance and extends the overall service life of the vent plug.

[0011] Compared with the prior art, the beneficial effects of this utility model are: This invention provides a one-way exhaust structure consisting of a valve plate, a spring, and a cover plate inside the vent of the drive axle. This structure keeps the vent plug closed under normal conditions and only opens automatically to exhaust air when the internal air pressure of the axle housing increases. This prevents external air, water, and dust from flowing back into the axle housing, thus ensuring the cleanliness and lubrication performance of the gear oil.

[0012] This structure eliminates the complex arrangement of traditional external long tubes, and the vent plug is directly installed in the vent of the axle housing, making the overall structure more compact and convenient for installation and maintenance.

[0013] Because the valve plate uses an elastic sealing material, it can form a reliable air seal when it fits against the end face of the plug, which can maintain a stable sealing effect when the vehicle is wading through water or on muddy roads, thereby improving the reliability of the whole vehicle.

[0014] In addition, the valve plate and the plug body are designed to be detachably connected, which makes it easy to replace the valve plate or clean the vent hole during the vehicle maintenance cycle, and helps to extend the service life of the vent plug and drive axle. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the existing technology; Figure 2 This is a schematic diagram of the structure of a preferred embodiment of the present invention; Figure 3 This is a cross-sectional view of the normally closed vent plug according to a preferred embodiment of the present invention.

[0016] In the diagram: 1. Bridge housing; 2. Vent port; 3. Plug body; 4. Vent passage; 5. Plug cap; 6. Valve plate; 7. Cover plate; 8. Spring. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0018] like Figures 1-3 As shown: A drive axle with a normally closed vent plug includes an axle housing 1. A vent 2 is provided on the axle housing 1, and a normally closed vent plug is installed at the vent 2.

[0019] The vent plug includes a plug body 3 and a plug cap 5. The outer circumference of the plug body 3 has a tapered thread structure, which is matched with the inner tapered thread of the vent port 2 to ensure reliable sealing even under long-term vibration. The plug body 3 has a venting channel 4 inside, the inner end of which communicates with the inner cavity of the bridge housing 1, and the outer end which serves as a gas outlet corresponding to the valve plate 6.

[0020] The cap 5 is fitted onto the outer end of the plug body 3, and the valve plate 6, cover plate 7, and spring 8 are installed inside it in sequence. The valve plate 6 covers the outlet of the ventilation channel 4, the cover plate 7 is located outside the valve plate 6, one end of the spring 8 abuts against the cover plate 7, and the other end abuts against the inner wall of the cap 5. The spring 8 applies pressure to the valve plate 6, so that the valve plate fits against the end face of the plug body 3 in the closed state to close the ventilation channel 4.

[0021] The valve plate 6 is made of an elastic sealing material, such as oil-resistant rubber or silicone rubber, which has good sealing performance and oil and temperature resistance.

[0022] The valve plate 6 and the plug body 3 are detachably connected at their end faces, which can be achieved by using a groove or pressure ring structure, making it easy to disassemble the valve plate during maintenance or replacement.

[0023] During normal vehicle operation, the gears in the drive axle mesh at high speed and agitate the lubricating oil. The frictional heat generated by the oil and the agitation effect cause the internal temperature of the axle housing to gradually rise. When the vehicle operates under high load for an extended period, the internal temperature can rise to over 80 degrees Celsius, causing the air to expand and the internal pressure of the axle housing to increase. At this point, when the internal pressure exceeds the force of spring 8, valve plate 6 is pushed open by the airflow, and the gas is discharged through the venting channel 4 via the gap between valve plate 6 and cover plate 7. After the gas is exhausted, the internal pressure drops, and spring 8 pushes valve plate 6 back to its original position and re-fits the end face, thus restoring the sealing state.

[0024] When the vehicle stops or enters a low-temperature environment, the temperature inside the axle housing gradually decreases and the gas contracts. However, since the valve plate 6 has a one-way structure, outside air cannot enter in the reverse direction, thus effectively preventing water from flowing back into the axle housing under wading conditions.

[0025] The vent plug of this invention is installed at the upper end of the axle housing, and the vent is positioned high, which further reduces the risk of water, dust, and mud backflow when the vehicle is wading through water.

[0026] The plug is connected to the plug cap via four evenly distributed clamping points along the circumference on the outer surface of the plug. The plug cap can still rotate slightly or float axially under the condition of being evenly clamped, so as to adapt to thermal expansion and contraction and ensure smooth opening and closing of the valve plate.

[0027] In summary, this utility model achieves a unified function of automatic air pressure balance and backflow prevention by installing a normally closed one-way vent plug in the drive axle vent. It is particularly suitable for commercial vehicle drive axle systems that are frequently subjected to water wading, rain, snow, or high-temperature heavy-load conditions.

[0028] Working principle: During vehicle start-up and normal driving, the main reducer and differential inside the drive axle operate at high speed. The meshing of gears and the churning of lubricating oil generate a large amount of heat, causing the air temperature inside the axle housing 1 to rise continuously. When the temperature rises to a certain level, the air inside the axle housing 1 expands due to heat, the gas volume increases, and the internal air pressure gradually exceeds the external atmospheric pressure.

[0029] At this time, the normally closed vent plug located at vent 2 begins to function. The venting channel 4 inside the plug body 3 connects the internal space of the bridge housing 1 with the valve plate 6, and air pressure acts on the inner side of the valve plate 6. When the internal air pressure is less than the force of the spring 8, the valve plate 6 is pressed against the end face of the plug body 3 under the force of the spring 8, and the venting channel 4 remains closed, preventing outside air, moisture, or dust from entering the interior of the bridge housing 1.

[0030] When the air pressure inside the axle housing 1 rises and exceeds the elastic force of the spring 8, the gas pressure pushes the valve plate 6 to move outward along the axis, overcoming the elastic force of the spring 8 and opening the venting channel 4. At this time, the gas is discharged through the venting channel 4 and the gap between the valve plate 6 and the cover plate 7, completing a one-way venting process, thereby balancing the air pressure inside and outside the axle housing 1 and preventing internal overpressure from damaging the oil seal.

[0031] As the gas is discharged, the air pressure inside the bridge housing 1 decreases. When the air pressure drops below the pressure of the spring 8, the spring 8 immediately pushes the valve plate 6 back to its original position, causing the valve plate 6 to re-adhere to the end face of the plug body 3, and the ventilation channel 4 is closed again. Because this valve structure is one-way opening, outside air and moisture cannot enter the bridge housing 1 in the reverse direction through the valve plate 6.

[0032] When the vehicle is driving on flooded roads or in rainy or snowy conditions, even if the external water flow submerges the vent plug, valve plate 6 remains closed, effectively preventing mud and water from flowing back in. After the vehicle resumes operation and warms up, the vent plug can continue to open and close automatically according to the aforementioned process, achieving automatic air pressure regulation.

[0033] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A drive axle for a normally closed vent plug, comprising an axle housing (1), characterized in that, The bridge housing (1) is provided with a vent (2), and a normally closed vent plug is installed at the vent (2); the normally closed vent plug includes a plug body (3) and a plug cap (5): The plug (3) is threadedly connected to the vent (2), and the plug (3) has a venting channel (4) inside, which communicates with the inner cavity of the bridge housing (1). The plug cap (5) is provided with a valve plate (6), a cover plate (7) and a spring (8) in sequence inside. The valve plate (6) covers the outlet of the ventilation channel (4), the cover plate (7) is located outside the valve plate (6), one end of the spring (8) abuts against the cover plate (7) and the other end abuts against the inner wall of the plug cap (5) to apply pressure to the valve plate (6) so that the valve plate (6) fits against the end face of the plug body (3) to close the ventilation channel (4); so that when the air pressure in the bridge housing (1) exceeds the pressure of the spring (8), the valve plate (6) and the cover plate (7) are pushed open to discharge the gas.

2. The drive axle of the normally closed vent plug according to claim 1, characterized in that, The outer circumference of the plug (3) is tapered thread, and the vent (2) is provided with an inner tapered thread that matches it.

3. The drive axle of the normally closed vent plug according to claim 1, characterized in that, The vent plug is installed at the upper end of the bridge housing (1).

4. The drive axle of the normally closed vent plug according to claim 1, characterized in that, The valve plate (6) is made of elastic sealing material.

5. The drive axle for the normally closed vent plug according to claim 1, characterized in that, The valve plate (6) and the end face of the plug (3) are detachably connected.

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