Axle box, axle box sealing control method and rail vehicle

Abstract

The invention discloses an axle box, an axle box sealing control method and a rail vehicle, and relates to the technical field of axle box sealing. Wherein the axle box body is provided with an inner cavity; the air supply pipe is used for supplying air into the inner cavity to increase the pressure of the inner cavity; the sealing assembly is connected with the axle box body and used for being switched from the first sealing state to the second sealing state when the inner cavity pressure is larger than the outer pressure of the axle box body so as to improve the sealing grade of the inner cavity. The axle box solves the problem that the sealing performance of the inner cavity of the axle box is difficult to effectively improve in a high-sandstorm environment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of axle box sealing, in particular to an axle box, an axle box sealing control method and a railway vehicle. BACKGROUND

[0002] With the rapid development of rail transit technology, high-speed EMUs have become the main equipment for long-distance trunk line transportation. As a key running part of the vehicle, the axle box device bears the important role of bearing the weight of the vehicle body, installing bearings and ensuring the stable rotation of the wheel set. The bearing operating environment cleanliness inside the axle box is directly related to the service life and operating reliability of the bearing, and thus affects the operation safety and maintenance cost of the entire bogie and even the train.

[0003] In the prior art, the sealing of the axle box of the high-speed EMU mainly relies on the labyrinth sealing structure, the contact type oil seal or the combined sealing device. The above-mentioned schemes can effectively block the entry of external dust and moisture into the inner cavity of the axle box under general environmental conditions. However, for the high-sand operating environment in northwest China, north China and other regions, when the train runs at a speed of 160 km / h or above, the concentration of sand particles in the air increases significantly, and the fine sand particle size can be as small as 0.075 mm or below. Under the strong airflow scouring and negative pressure adsorption effect generated by the high-speed running of the vehicle, the traditional sealing structure is difficult to completely prevent the invasion of sand, and the phenomenon of sand entering the inner cavity of the axle box occurs from time to time.

[0004] After the sand enters the inner cavity of the axle box, it will mix into the rolling contact area with the flow of the bearing grease, resulting in the deterioration of the bearing operating environment cleanliness. The hard particle characteristics of the sand particles can exacerbate the abrasive wear of the raceway and the roller surface, destroy the integrity of the lubricating oil film, cause abnormal vibration and noise, and accelerate the aging and deterioration of the lubricating grease, seriously affecting the service life and reliability of the bearing, and increasing the frequency of unplanned maintenance and operating costs.

[0005] Therefore, how to effectively improve the sealing performance of the inner cavity of the axle box under the high-sand environment has become a technical problem to be solved for the bogie technology of the high-speed EMU. SUMMARY

[0006] The purpose of the present application is to provide an axle box, an axle box sealing control method and a railway vehicle, which solves the problem that it is difficult to effectively improve the sealing performance of the inner cavity of the axle box under the high-sand environment.

[0007] To achieve the above-mentioned purpose, the present application provides an axle box, comprising:

[0008] An axle box body having an inner cavity;

[0009] An air supply pipe for supplying air to the inner cavity to increase the pressure of the inner cavity;

[0010] A sealing assembly is connected to the axle box body and is used to switch from a first sealing state to a second sealing state when the pressure in the inner cavity is greater than the pressure outside the axle box body, so as to improve the sealing level of the inner cavity.

[0011] In some embodiments, the sealing assembly comprises:

[0012] An end cover is connected to an end of the axle box body.

[0013] A retaining ring is used to be installed on the axle shaft.

[0014] A contact seal is arranged between the end cover and the retaining ring and is used to seal the gap between the end cover and the retaining ring.

[0015] In some embodiments, the contact seal extends out at least two sealing lips at one end close to the retaining ring, and the at least two sealing lips are in contact with the retaining ring.

[0016] In some embodiments, the number of sealing lips is two, the contact seal comprises a connecting portion, the inner sealing lip comprises a transition portion and an abutting portion, the abutting portion is connected to the connecting portion through the transition portion, and the transition portion and the abutting portion are configured to abut against the retaining ring when the pressure in the inner cavity is greater than the pressure outside the axle box body.

[0017] In some embodiments, the middle section of the transition portion has a small cross-sectional size, and the two ends have a large cross-sectional size.

[0018] In some embodiments, the inner wall at the connection between the two sealing lips is arc-shaped.

[0019] In some embodiments, a sealing cavity is formed between the two sealing lips.

[0020] In some embodiments, the sealing assembly further comprises a support frame, the support frame is bent, the support frame is connected to the end cover, and at least part of the structure of the support frame is embedded in the contact seal.

[0021] In some embodiments, the axle box further comprises:

[0022] A pressure detection assembly is installed on the axle box body and is used to detect the pressure in the inner cavity in real time.

[0023] A control assembly is connected in communication with the pressure detection assembly and is used to control the air supply of the air supply pipe according to the pressure feedback in real time by the pressure detection assembly.

[0024] The application also provides an axle box sealing control method, which is applied to the axle box described in any one of the above embodiments, and the axle box sealing control method comprises:

[0025] acquire the inner cavity pressure and the external pressure of the axle box body;

[0026] when the difference between the inner cavity pressure and the external pressure of the axle box body meets a preset condition, control the air supply pipe to supply air into the inner cavity, so that the sealing assembly is switched from the first sealing state to the second sealing state, and the sealing level of the inner cavity is improved.

[0027] The application further provides a railway vehicle, comprising an axle and wheels, the wheels being arranged at two ends of the axle, and further comprising the axle box according to any one of the above-mentioned embodiments, the axle being supported in the axle box at two ends outside the wheels.

[0028] With respect to the background art, the axle box provided by the embodiments of the application comprises an axle box body, an air supply pipe and a sealing assembly. The axle box body has an inner cavity; the air supply pipe is used to supply air into the inner cavity to increase the inner cavity pressure; and the sealing assembly is connected with the axle box body and is used to be switched from a first sealing state to a second sealing state when the inner cavity pressure is greater than the external pressure of the axle box body, so as to improve the sealing level of the inner cavity.

[0029] The axle box sealing control method provided by the embodiments of the application is applied to the above-mentioned axle box, and the axle box sealing control method comprises: acquiring the inner cavity pressure and the external pressure of the axle box body; and when the difference between the inner cavity pressure and the external pressure of the axle box body meets a preset condition, controlling the air supply pipe to supply air into the inner cavity, so that the sealing assembly is switched from the first sealing state to the second sealing state, and the sealing level of the inner cavity is improved.

[0030] The axle box and the axle box sealing control method thus arranged have the following beneficial effects:

[0031] Firstly, the traditional sealing structure relies on a passive blocking mechanism, and the strong airflow scouring and negative pressure adsorption effect generated by high-speed operation easily lead to sealing failure. Compared with this, the application actively supplies air into the inner cavity through the air supply pipe to form a stable positive pressure, so that the inner cavity pressure of the axle box is always higher than the external pressure, the sealing mechanism is upgraded from passive blocking to active defense, and the penetration direction of sand and dust is fundamentally reversed, effectively solving the technical problem that the external sand and dust invades the inner cavity of the axle box under the driving of pressure difference in a high wind and sand environment.

[0032] Secondly, in view of the defect that the traditional sealing state is fixed and cannot adapt to environmental changes, the sealing assembly of the application can automatically switch from the first sealing state to the second sealing state according to the pressure difference between the inner cavity and the outer cavity. Through seamless switching of the two sealing states, when the concentration of sand and dust increases or the vehicle speed increases to cause the external negative pressure to increase, the inner cavity pressure responsiveness increases and triggers the sealing level to be improved, forming an intelligent self-adaptive sealing strengthening mechanism, which ensures that the sealing performance is dynamically strengthened under harsh working conditions, and overcomes the rigid defect that the traditional sealing is either all or nothing. At the same time, through the efficient sealing driven by the pressure difference, the fine particles of sand and dust are effectively prevented from entering, the cleanliness level of the inner cavity of the shaft box is maintained, hard particles are prevented from mixing into the rolling contact area, thereby significantly reducing the abnormal wear rate of the bearing, delaying the aging of the lubricating grease, and making the actual service life of the bearing close to the designed service life, thereby solving the problem of bearing life reduction caused by poor environmental cleanliness. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the application or the related art, the following will briefly introduce the drawings needed to be used in the embodiment or related art description. Obviously, the drawings in the following description only constitute the embodiments of the application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of the provided drawings.

[0034] Figure 1 It is a structural schematic diagram of the shaft box in the embodiment of the application.

[0035] Figure 2 It is Figure 1 a cross-sectional structural schematic diagram of the shaft box shown.

[0036] Figure 3 It is Figure 2 an assembly schematic diagram of the sealing assembly in the embodiment.

[0037] Figure 4 It is Figure 3 an enlarged schematic diagram of the sealing assembly.

[0038] Figure 5 It is a flowchart of the shaft box sealing control method in the embodiment of the application Figure 1 .

[0039] Figure 6 It is a flowchart of the shaft box sealing control method in the embodiment of the application Figure 2 .

[0040] Among them:

[0041] 10-shaft box body; 11-inner cavity;

[0042] 20-air supply pipe;

[0043] 30 - Sealing assembly; 31 - End cap; 32 - Retaining ring; 33 - Contact seal; 331 - Sealing lip; 3311 - Transition portion; 3312 - Abutment portion; 332 - Connecting portion; 333 - Sealing cavity; 34 - Support frame;

[0044] 40 - Pressure detection component;

[0045] 50-axle. Detailed Implementation

[0046] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0047] To enable those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0048] It should be noted that the directional terms such as "upper end," "lower end," "left side," and "right side" mentioned below are defined based on the accompanying drawings in the instruction manual.

[0049] Please refer to Figures 1 to 6 , Figure 1 This is a schematic diagram of the axle box structure in an embodiment of this application. Figure 2 for Figure 1 A schematic diagram of the cross-sectional structure of the axle box shown. Figure 3 for Figure 2 Assembly diagram of the central sealing assembly. Figure 4 for Figure 3 Enlarged schematic diagram of the central sealing assembly. Figure 5 The flowchart of the axle box sealing control method in the embodiments of this application is as follows. Figure 1 . Figure 6 The flowchart of the axle box sealing control method in the embodiments of this application is as follows. Figure 2 .

[0050] Please see Figure 1 The axle box provided in this application embodiment includes an axle box body 10, an air supply pipe 20, and a sealing assembly 30.

[0051] Please refer to the following: Figure 2 The axle box body 10 has an inner cavity 11 for the axle 50 to pass through. The wheels are located at both ends of the axle 50, and the two ends of the axle 50 located outside the wheels are respectively supported in the inner cavity 11 of the axle box body 10. In addition, the bearing assembly fitted on the axle 50 is housed in the inner cavity 11 to protect the bearing assembly.

[0052] The air supply duct 20 is used to supply air into the inner cavity 11 to increase the pressure in the inner cavity 11. The air supply duct 20 can be fixed to the shaft box body 10 or to the end cap 31 connected to the shaft box body 10. Specifically, the air supply duct 20 can be an air supply hose, the other end of which is connected to an air source device / air supply system. The air source device / air supply system is used to supply air into the inner cavity 11 through the air supply hose to increase the pressure in the inner cavity 11.

[0053] The sealing assembly 30 is connected to the axle box body 10. The sealing assembly 30 is used to switch from a first sealing state to a second sealing state when the pressure in the inner cavity 11 is greater than the external pressure of the axle box body 10, so as to improve the sealing level of the inner cavity 11. For example, when the sealing assembly 30 is in the first sealing state, the sealing level of the inner cavity 11 is level one, and when the sealing assembly 30 is in the second sealing state, the sealing level of the inner cavity 11 is level two, and the level two sealing level is higher than the level one sealing level.

[0054] In the process of sealing the axle box, firstly, the pressure inside the cavity 11 of the axle box body 10 and the external pressure are obtained; then, when the difference between the pressure inside the cavity 11 of the axle box body 10 and the external pressure meets the preset conditions, the air supply pipe 20 is controlled to supply air to the cavity 11, so that the sealing assembly 30 switches from the first sealing state to the second sealing state, thereby improving the sealing level of the cavity 11.

[0055] For example, when the vehicle is running, the pressure difference between the inside and outside of the axle box body 10 can be tested in real time by a pressure sensor. When the pressure inside the axle box body 10 is lower than the external pressure, or when the pressure inside the axle box body 10 is higher than the external pressure by less than 5 kPa and remains higher for more than 1 second, the vehicle's air supply system is controlled to supply air to the inside of the axle box body 10 through the air supply hose; when the internal pressure is higher than the external pressure by more than 10 kPa, the air supply is stopped.

[0056] This ensures that the internal air pressure of the axle box body 10 is always slightly higher than the external pressure, thus guaranteeing a good sealing effect.

[0057] To address the problems faced by traditional high-speed trains in high-wind and sandy environments, such as sand ingress into axle boxes leading to deterioration of bearing cleanliness, accelerated wear, and decreased reliability, the axle box technical solution provided in this application has the following significant advantages:

[0058] Firstly, it adopts an active defense mechanism to fundamentally solve the problem of sand and dust intrusion: Traditional sealing structures rely on passive blocking mechanisms, which are prone to sealing failure under the strong airflow and negative pressure adsorption effects generated by high-speed operation above 160 km / h. In contrast, this application actively supplies air to the inner cavity 11 through the air supply pipe 20 to form a stable positive pressure, so that the pressure in the inner cavity 11 of the axle box body 10 is always higher than the external pressure. This upgrades the sealing mechanism from passive blocking to active defense, fundamentally reversing the direction of sand and dust infiltration and effectively solving the technical problem of external sand and dust intruding into the inner cavity 11 of the axle box body 10 under pressure difference drive in high-wind and sandy environments.

[0059] Secondly, the adaptive sealing level is improved, dynamically matching harsh working conditions: Addressing the shortcomings of traditional technologies where the sealing state is fixed and unable to adapt to environmental changes, the sealing component 30 of this application can automatically switch from a first sealing state to a second sealing state based on the pressure difference between the inner and outer cavities of the axle box body 10. Through seamless switching between the two sealing states, when the concentration of sandstorms increases or the vehicle speed increases, leading to enhanced external negative pressure, the pressure response of the inner cavity 11 increases, triggering a sealing level upgrade. This forms an intelligent adaptive sealing enhancement mechanism, ensuring dynamic strengthening of sealing performance under harsh working conditions and overcoming the rigid defects of traditional seals that are either all-or-nothing.

[0060] Thirdly, it significantly improves the cleanliness of the bearing operating environment and extends the bearing's service life: Existing technologies clearly indicate that dust intrusion leads to bearing grease contamination, raceway abrasive wear, and oil film damage. In contrast, this application, through a pressure differential-driven high-efficiency seal, effectively prevents fine dust particles smaller than 0.075mm from entering, maintaining the cleanliness level of the inner cavity 11 of the bearing housing 10, and preventing hard particles from mixing into the rolling contact area. This significantly reduces the abnormal wear rate of the bearing, delays grease aging, and brings the actual bearing service life close to the design life, solving the problem of reduced bearing life caused by poor environmental cleanliness.

[0061] Fourth, it enhances operational reliability and reduces the frequency of unplanned maintenance: Early bearing failure caused by traditional seal failure is the main cause of unplanned bogie maintenance. In contrast, this application ensures that the axle box seal reliability increases rather than decreases as operating conditions worsen through seamless switching between two levels of sealing. This eliminates the risk of abnormal vibration, noise, and temperature rise caused by sand and dust at the source, significantly improving the operational reliability of key bogie components, reducing downtime and temporary repairs due to bearing failure, and lowering the total life cycle maintenance cost.

[0062] Fifth, it boasts strong structural compatibility and adaptability to multi-condition collaborative control: This embodiment can be integrated with existing vehicle air supply systems such as brake air supply or auxiliary air supply systems without adding an independent power source. By further adding a control module, the pressure in the inner cavity 11 can be flexibly adjusted, ensuring that the sealing level not only adapts to sandstorm environments but also simultaneously copes with high-pressure water mist environments such as rain erosion and vehicle body washing. This achieves a single system with multiple protections, exhibiting significant environmental adaptability and economy, and is particularly suitable for complex operating conditions such as high sandstorms and seasonal strong winds in Northwest my country.

[0063] In summary, the embodiments of this application, through the synergistic innovation of active pressure control and adaptive state switching, specifically address the pain point of axle box seal failure in high-speed trains under high wind and sand conditions in the prior art, and achieve a comprehensive improvement in the cleanliness of the bearing operating environment, component life and system reliability.

[0064] Please refer to the following: Figure 2 , Figure 3 and Figure 4 The sealing assembly 30 includes an end cap 31, a retaining ring 32, and a contact seal 33.

[0065] The end cap 31 can be a rear end cap, which is connected to the end (rear end) of the axle box body 10. The rear end cap and the front end cap are respectively installed at the rear end and the front end of the axle box body 10, so that the inner cavity 11 of the axle box body 10 is a closed inner cavity 11. The retaining ring 32 is installed on the axle 50, and the retaining ring 32 is specifically a rear retaining ring. The contact seal 33 is provided between the end cap 31 and the retaining ring 32, and the contact seal 33 is used to seal the gap between the end cap 31 and the retaining ring 32.

[0066] It should be noted that the end cover 31, retaining ring 32, and contact seal 33 together constitute the rear-end sealing and positioning system of the axle box assembly: the retaining ring 32 is mounted on the axle and rotates at high speed with the wheel (the retaining ring 32 is a moving part), while the end cover 31 is mounted on the axle box body 10 and remains stationary (the end cover 31 is a stationary part). The axle box body 10 serves as the main body, housing the bearing and being fixedly connected to the end cover 31. After the end cover 31, retaining ring 32, and contact seal 33 are assembled at the rear end of the axle box body 10, they work together to achieve axial positioning, bearing clamping, dynamic sealing, and dust prevention functions.

[0067] In some embodiments, at least two sealing lips 331 extend from the end of the contact seal 33 near the retaining ring 32, and the at least two sealing lips 331 contact and abut against the retaining ring 32.

[0068] In this way, the contact seal 33 is disposed between the end cap 31 and the retaining ring 32. At least two sealing lips 331 of the contact seal 33 near the end of the retaining ring 32 contact and abut against the retaining ring 32 to seal the gap between the end cap 31 and the retaining ring 32. Furthermore, by adjusting the contact state between the at least two sealing lips 331 and the retaining ring 32, a higher level of sealing is achieved.

[0069] In some embodiments, two sealing lips 331 are provided, one being an outer sealing lip 331 and the other an inner sealing lip 331.

[0070] The two sealing lips 331 form a series (or superimposed) sealing effect: the outer sealing lip 331 takes the lead in intercepting most of the sand and dust; the inner sealing lip 331 acts as the second barrier to further intercept the remaining particles.

[0071] In this way, the redundant design of the sealing lip 331 ensures that the sealing function is not interrupted even after a single lip wears out or fails instantly, which meets the principle of high reliability redundancy.

[0072] It is important to emphasize that a sealing cavity 333 is formed between the two sealing lips 331. A microscopic sand trap is formed between the two sealing lips 331 and the retaining ring 32: after particles are scraped off by the first lip, most remain in the sealing cavity 333 between the two sealing lips 331 and cannot directly reach the bearing side. When, by chance, particles cross the sealing cavity 333 and become stuck at the position of the inner sealing lip 331, the inner sealing lip 331 opens, allowing internal air pressure to leak out and carry away the particles at the sealing position, thus providing a certain degree of cleaning.

[0073] Specifically, the contact seal 33 includes a connecting portion 332, and the inner sealing lip 331 includes a transition portion 3311 and an abutting portion 3312. The abutting portion 3312 is connected to the connecting portion 332 through the transition portion 3311. The transition portion 3311 and the abutting portion 3312 are configured to abut against the retaining ring 32 when the pressure in the inner cavity 11 is greater than the external pressure of the axle box body 10.

[0074] For example, the middle section of the transition section 3311 has a small cross-sectional size, while the two ends have large cross-sectional sizes.

[0075] Understandably, the transition section 3311 adopts an hourglass-shaped cross-section design that is thin in the middle and thick at both ends, forming an elastic hinge structure: when there is no wind pressure, the contact section 3312 only maintains light pressure, with low friction and low wear rate; when the inner cavity 11 is filled with air, for example, when the internal and external pressure difference ΔP exceeds the threshold, the pressure acts on the inner surface of the transition section 3311, causing the thin-walled hinge to flex elastically, driving the contact section 3312 to expand outward and fit tightly against the retaining ring 32.

[0076] In other words, the contact seal 33 adopts a two-part rubber sealing lip structure. The inner sealing lip 331 has a thicker cross section at the contact position and a thinner cross section in the transition area. When the internal pressure of the axle box body 10 is higher than the external pressure by a certain value, the transition area of ​​the inner sealing lip 331 is concave due to the internal pressure (that is, elastic deflection occurs). The contact area of ​​the sealing lip 331 is pushed towards the retaining ring 32 by the air pressure, so that the contact seal 33 and the retaining ring 32 are in closer contact, thereby achieving a better sealing effect.

[0077] With this configuration, under normal conditions, the contact seal 33, which has a two-part rubber sealing lip structure, has only the abutting portion 3312 of its inner and outer sealing lips 331 abutting against the retaining ring 32. This achieves a first-level sealing state by sealing the gap between the end cover 31 and the retaining ring 32. When operating in a high-wind and sandy environment, and when the pressure inside the axle box is lower than the external pressure, or when the pressure inside the axle box is more than 5 kPa higher than the external pressure and remains so for more than 1 second, the vehicle's air supply system supplies air to the axle box through the air supply hose. By adjusting the contact state between the inner sealing lip 331 and the retaining ring 32, a higher level of sealing state (i.e., a second sealing state) can be achieved. Specifically, the transition area of ​​the inner sealing lip 331 is concave (i.e., elastically flexed) by the internal pressure. The contact area of ​​the sealing lip 331 is pushed towards the retaining ring 32 by the air pressure, so that the abutting portion 3312 and the transition portion 3311 both contact the retaining ring 32. This not only increases the contact area but also makes the contact tighter, thereby achieving a better sealing effect.

[0078] It should be noted that a pressure adaptive mechanism can be used to manage the sealing contact stress. Positively correlated with ΔP: Where k is related to the wall thickness and material hardness of the transition section 3311. This represents the initial contact stress. This will produce a positive sealing effect: the worse the wind and sand, the higher the internal pressure automatically becomes, leading to greater contact stress and making it more difficult for sand particles to penetrate.

[0079] In some embodiments, the inner wall at the junction of the two sealing lips 331 is arc-shaped, and a sealing cavity 333 is formed between the two sealing lips 331.

[0080] In this way, a local static pressure buffer chamber is formed by the double-lip arc surface enclosing the sealed cavity 333. That is, the root of the two lips is transitioned by a large R arc surface to form a miniature sealed cavity 333.

[0081] When the train is running at high speed and a transient negative pressure pulse occurs outside the train (such as when two trains meet or at the tunnel exit), the sealing cavity 333 is equivalent to an air spring: the air inside the cavity is compressed instantaneously, generating reverse pressure to offset the peak of the negative pressure on the outside, while preventing sand particles from being sucked back across the second lip (i.e., the inner sealing lip 331).

[0082] In some embodiments, the sealing assembly 30 further includes a support frame 34, which is bent and connected to the end cap 31, with at least a portion of the structure of the support frame 34 embedded in the contact seal 33.

[0083] Of course, depending on actual needs, the support frame 34 can be formed by stamping stainless steel and bent into an L shape: the horizontal side is press-fitted to the end cap 31 or directly bonded and fixed by adhesive to provide axial positioning; the vertical side is embedded in the connection part 332 of the contact seal 33 to form an incompressible rigid backing, thereby ensuring the stability of the contact seal 33.

[0084] When the internal and external pressure difference rises to a preset high value, the support frame 34 can prevent the contact seal 33 from being pushed to the other side by the high pressure, thus avoiding gap extrusion failure and ensuring the stability and reliability of the seal.

[0085] By adopting the above configuration, under the combined effect of four mechanisms—pressure self-adaptation, redundant sand scraping, local static pressure buffering, and rigid anti-extrusion—the sealing level can be improved by at least one level, the bearing life can be extended, and the operational needs of high-speed trains in high-wind and sandy conditions can be met.

[0086] Based on the above, a dynamic seal (labyrinth seal structure, specifically including 3-5 sealing grooves) is also formed between the inner wall of the end cap 31 and the rotating retaining ring 32 to prevent grease leakage and foreign matter from entering. The end cap 31 is further provided with a dustproof structure (double labyrinth groove) to enhance dustproof capability.

[0087] In this way, by adding 3-5 dynamic labyrinths and double dustproof labyrinth grooves between the end cap 31 and the rotating retaining ring 32, the entire sealing system forms a three-stage series sealing mechanism of active positive pressure + contact sand scraping + labyrinth throttling, which has a higher capture efficiency for sand and dust particles of different sizes and further improves the sealing effect.

[0088] In some embodiments, the axle box further includes a pressure detection component 40 and a control component.

[0089] The pressure detection component 40 is installed on the shaft box body 10 and is used to detect the pressure of the inner cavity 11 in real time. The control component is connected to the pressure detection component 40 in communication and is used to control the air supply pipe 20 to supply air according to the pressure feedback from the pressure detection component 40 in real time.

[0090] The pressure detection component 40 can be configured as a pressure sensor to detect the absolute pressure of the inner cavity 11 in real time. It converts the pressure into an electrical signal in real time, and the control components acquire the absolute pressure outside the vehicle in real time. and through The effective sealing pressure differential was calculated.

[0091] During vehicle operation, the pressure difference between the inside and outside of the axle box body 10 is tested in real time. When the internal pressure of the axle box body 10 is lower than the external pressure, or when the internal pressure of the axle box body 10 is higher than the external pressure by less than 5 kPa and remains higher for more than 1 second, the vehicle's air supply system is controlled to supply air to the inside of the axle box body 10 through the air supply hose. When the internal pressure is higher than the external pressure by more than 10 kPa, the air supply is stopped, so that the internal air pressure of the axle box body 10 is always slightly higher than the external pressure, thereby ensuring a good sealing effect.

[0092] Under the closed-loop control of the pressure detection component 40 and the control component, the axle box is upgraded from passive constant pressure to intelligent variable positive pressure, resulting in the following direct benefits:

[0093] Firstly, sand and dust always enter against the wind. Pressure sensors transmit the actual pressure inside the chamber, and the control components continuously fine-tune the airflow to maintain the pressure difference between the inside and outside of the axle box 10 within a set range (the threshold can be set according to the actual operating environment). Real-vehicle tests show that even with a negative pressure pulse from oncoming traffic at 300 km / h outside the vehicle, the system can quickly bring the pressure difference between the inside and outside of the axle box 10 back to a safe zone, significantly reducing sand and dust intrusion compared to a constant pressure solution.

[0094] Secondly, the bearing life is further extended. The internal pressure is maintained within a suitable range—neither too high (to avoid excessive wear of the sealing lip 331 and increased power consumption) nor too low (to prevent negative pressure backflow). This allows the sand content of the bearing grease to be kept below 0.02%, reducing the intensity of bearing vibration and further extending the bearing's service life.

[0095] Third, both vehicle energy consumption and noise are reduced. Compared to the crude solution of always maintaining maximum airflow, closed-loop control maintains an appropriate airflow, reducing energy consumption while also reducing air supply noise.

[0096] Fourth, it adopts early warning maintenance to achieve zero sudden sand ingress. When the pressure sensor detects that the pressure is below a certain value for 30 seconds (abnormal sealing or leakage in the air supply pipeline), the control component immediately sends an early warning of axle box seal degradation to the central control. The driver can then limit the speed or return to the depot for maintenance in advance, eliminating the previous serious incidents of sudden sand ingress, bearing overheating, and road closure.

[0097] Fifth, it offers the best overall life-cycle cost. It avoids excessive wear of the sealing lip 331 caused by excessive air supply, and also avoids expensive wheel replacements due to sand and dust intrusion, further reducing operation and maintenance costs.

[0098] In some embodiments, considering that during long downhill runs or continuous operation at 350 km / h, the brake disc radiates heat to the axle box, causing a bearing temperature rise of 10-15 degrees Celsius and shortening the grease life, a hollow annular cavity of a predetermined size (e.g., 2 mm) is cast into the outer flange of the end cap 31. The hollow annular cavity is filled with a paraffin-graphene composite phase change material (melting point 65 degrees Celsius). In this way, during the peak braking heat phase, the paraffin-graphene composite phase change material absorbs heat and melts, reducing the axle box surface temperature by 8-10 degrees Celsius; at night or when stopped, the paraffin-graphene composite phase change material solidifies and releases heat, which is transferred back to the bearing outer ring through the heat conduction grid, keeping the grease in the optimal viscosity range of 55-60 degrees Celsius, reducing wear during cold starts the next day.

[0099] By adopting the above configuration, the temperature fluctuation of the bearing outer ring can be reduced, thereby saving grease for each train and achieving the goal of carbon reduction.

[0100] In summary, regarding the problems faced by traditional high-speed trains in high-wind and sandy environments, such as sand ingress into axle boxes leading to deterioration of bearing cleanliness, accelerated wear, and decreased reliability, the axle box technical solution provided in this application has the following significant advantages:

[0101] Firstly, it adopts an active defense mechanism to fundamentally solve the problem of sand and dust intrusion: Traditional sealing structures rely on passive blocking mechanisms, which are prone to sealing failure under the strong airflow and negative pressure adsorption effects generated by high-speed operation above 160 km / h. In contrast, this application actively supplies air to the inner cavity 11 through the air supply pipe 20 to form a stable positive pressure, so that the pressure in the inner cavity 11 of the axle box body 10 is always higher than the external pressure. This upgrades the sealing mechanism from passive blocking to active defense, fundamentally reversing the direction of sand and dust infiltration and effectively solving the technical problem of external sand and dust intruding into the inner cavity 11 of the axle box body 10 under pressure difference drive in high-wind and sandy environments.

[0102] Secondly, the adaptive sealing level is improved, dynamically matching harsh working conditions: Addressing the shortcomings of traditional technologies where the sealing state is fixed and unable to adapt to environmental changes, the sealing component 30 of this application can automatically switch from a first sealing state to a second sealing state based on the pressure difference between the inner and outer cavities of the axle box body 10. Through seamless switching between the two sealing states, when the concentration of sandstorms increases or the vehicle speed increases, leading to enhanced external negative pressure, the pressure response of the inner cavity 11 increases, triggering a sealing level upgrade. This forms an intelligent adaptive sealing enhancement mechanism, ensuring dynamic strengthening of sealing performance under harsh working conditions and overcoming the rigid defects of traditional seals that are either all-or-nothing.

[0103] Thirdly, it significantly improves the cleanliness of the bearing operating environment and extends the bearing's service life: Existing technologies clearly indicate that dust intrusion leads to bearing grease contamination, raceway abrasive wear, and oil film damage. In contrast, this application, through a pressure differential-driven high-efficiency seal, effectively prevents fine dust particles smaller than 0.075mm from entering, maintaining the cleanliness level of the inner cavity 11 of the bearing housing 10, and preventing hard particles from mixing into the rolling contact area. This significantly reduces the abnormal wear rate of the bearing, delays grease aging, and brings the actual bearing service life close to the design life, solving the problem of reduced bearing life caused by poor environmental cleanliness.

[0104] Fourth, it enhances operational reliability and reduces the frequency of unplanned maintenance: Early bearing failure caused by traditional seal failure is the main cause of unplanned bogie maintenance. In contrast, this application ensures that the axle box seal reliability increases rather than decreases as operating conditions worsen through seamless switching between two levels of sealing. This eliminates the risk of abnormal vibration, noise, and temperature rise caused by sand and dust at the source, significantly improving the operational reliability of key bogie components, reducing downtime and temporary repairs due to bearing failure, and lowering the total life cycle maintenance cost.

[0105] Fifth, it boasts strong structural compatibility and adaptability to multi-condition collaborative control: This embodiment can be integrated with existing vehicle air supply systems such as brake air supply or auxiliary air supply systems without adding an independent power source. By further adding a control module, the pressure in the inner cavity 11 can be flexibly adjusted, ensuring that the sealing level not only adapts to sandstorm environments but also simultaneously copes with high-pressure water mist environments such as rain erosion and vehicle body washing. This achieves a single system with multiple protections, exhibiting significant environmental adaptability and economy, and is particularly suitable for complex operating conditions such as high sandstorms and seasonal strong winds in Northwest my country.

[0106] Please refer to the following: Figure 5 This application also provides a method for controlling the sealing of an axle box, applicable to an axle box according to any of the above-mentioned methods. The method for controlling the sealing of an axle box includes:

[0107] S1: Obtain the pressure inside the cavity 11 and the external pressure of the axle box body 10;

[0108] S2: When the pressure difference between the inner cavity 11 and the external pressure of the axle box body 10 meets the preset conditions, control the air supply pipe 20 to supply air to the inner cavity 11 so that the sealing assembly 30 switches from the first sealing state to the second sealing state, thereby improving the sealing level of the inner cavity 11.

[0109] The sealing assembly 30 includes an end cap 31, a retaining ring 32, and a contact seal 33. At least two sealing lips 331 (preferably two sealing lips 331, namely an inner sealing lip 331 and an outer sealing lip 331) of the contact seal 33 near the end of the retaining ring 32 contact and abut against the retaining ring 32 to seal the gap between the end cap 31 and the retaining ring 32.

[0110] The two sealing lips 331 form a series (or superimposed) sealing effect: the outer sealing lip 331 takes the lead in intercepting most of the sand and dust; the inner sealing lip 331 acts as the second barrier to further intercept the remaining particles.

[0111] A sealing cavity 333 is formed between the two sealing lips 331.

[0112] The contact seal 33 includes a connecting portion 332, and the inner sealing lip 331 includes a transition portion 3311 and an abutting portion 3312. The abutting portion 3312 is connected to the connecting portion 332 through the transition portion 3311. The transition portion 3311 and the abutting portion 3312 are configured to abut against the retaining ring 32 when the pressure in the inner cavity 11 is greater than the external pressure of the axle box body 10.

[0113] The transition section 3311 adopts an hourglass-shaped cross-section design that is thin in the middle and thick at both ends, forming an elastic hinge structure.

[0114] In this way, the contact seal 33 adopts a two-part rubber sealing lip structure. The inner sealing lip 331 has a thicker cross section at the contact position and a thinner cross section in the transition area. When the internal pressure of the axle box body 10 is higher than the external pressure by a certain value, the transition area of ​​the inner sealing lip 331 is concave due to the internal pressure (that is, elastic deflection occurs). The contact area of ​​the sealing lip 331 is pushed towards the retaining ring 32 by the air pressure, so that the contact seal 33 and the retaining ring 32 are in closer contact, thereby achieving a better sealing effect.

[0115] Please refer to the following: Figure 6 In the axle box sealing control method of this application, the absolute pressure of the inner cavity 11 is detected in real time by a pressure sensor. It converts the pressure into an electrical signal in real time, and the control components acquire the absolute pressure outside the vehicle in real time. and through The pressure difference between the inner cavity 11 and the outer pressure of the axle box body 10 is calculated. When the pressure inside the axle box body 10 is lower than the outer pressure, or when the pressure inside the axle box body 10 is higher than the outer pressure by less than 5 kPa and remains higher for more than 1 second, the vehicle's air supply system is controlled to supply air to the inside of the axle box body 10 through the air supply hose; when the internal pressure is higher than the outer pressure by more than 10 kPa, the air supply is stopped, so that the air pressure inside the axle box body 10 is always slightly higher than the outer pressure by a certain value, thereby ensuring a good sealing effect.

[0116] When accidental factors cause particulate matter to cross the sealing cavity 333 and intrude into and become stuck in the inner sealing lip 331, the inner sealing lip 331 opens, and the internal air pressure leaks out from here, which will carry away the particulate matter in the sealing position and play a certain cleaning role.

[0117] It should be noted that the jamming-pressure relief-self-cleaning mechanism is another protective mechanism derived from the inner sealing lip 331 under abnormal operating conditions. Its physical process mainly includes:

[0118] When trains meet at high speed or when the peak concentration of sandstorms exceeds a certain threshold, a very small number of particles may penetrate the sealing cavity 333. After the particles reach the inner lip, they wedge into the space between the inner sealing lip 331 and the retaining ring 32, forming a micro-level bypass gap. The gap height is approximately equal to the equivalent diameter of the particles. At this time, the local leakage rate increases suddenly, and the pressure inside the cavity begins to decrease.

[0119] After the pressure drops, the control components immediately increase the air supply flow to maintain the overall pressure difference within the set range. However, the inner lip loses support due to the wedging of particles, resulting in imbalance. Specifically, the transition section 3311 (hourglass deformation section) bends and deforms under pressure, and the lip opens at a certain angle to form a transient nozzle. The high-speed airflow in the inner cavity 11 can generate instantaneous thrust on the particles. This thrust is greater than the rubber-particle adhesion force. Once the particles detach from the lip surface, they are sucked in by the turbulent vortex and enter the sealed cavity 333, eventually falling out of the vehicle with the vibration.

[0120] In this way, the jamming-pressure relief-self-cleaning function of the inner sealing lip 331 gives the axle box sealing system a self-healing capability in addition to active defense, providing a final reliable guarantee for continuous, safe, and maintenance-free operation in high-wind and sandy environments. At the same time, the self-cleaning function of the contact seal 33 can further extend the service life of the contact seal 33 and the bearing in the inner cavity 11.

[0121] In summary, this application also provides an axle box and its sealing control method. By actively controlling the positive pressure inside the axle box and combining it with a contact sealing structure, the sealing performance of the axle box is improved. This not only solves the problem that conventional seals cannot prevent small particles from entering, but also solves the problem that labyrinth seals fail due to local air pressure disturbances in high wind and sand environments.

[0122] This application also provides a rail vehicle, including an axle 50 and wheels, with the wheels located at both ends of the axle 50, and also including an axle box as described above, with the two ends of the axle 50 located outside the wheels respectively supported in the axle box. Other parts of the rail vehicle can be referred to in related technologies, and will not be elaborated here.

[0123] It should be noted that in this specification, relational terms such as first and second are used only to distinguish one entity from several other entities, and do not necessarily require or imply any such actual relationship or order between these entities.

[0124] The axle box, axle box sealing control method, and rail vehicle provided in this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the solution and core ideas of this application. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of this application.

Claims

1. An axle box, characterized in that, include: The axle box body (10) has an inner cavity (11); An air supply pipe (20) is used to supply air into the inner cavity (11) to increase the pressure in the inner cavity (11); A sealing assembly (30) is connected to the axle box body (10) and is used to switch from a first sealing state to a second sealing state when the pressure in the inner cavity (11) is greater than the external pressure of the axle box body (10), so as to improve the sealing level of the inner cavity (11).

2. The axle box as described in claim 1, characterized in that, The sealing assembly (30) includes: End cap (31) is connected to the end of the axle box body (10); A retaining ring (32) is used for mounting on the axle (50); A contact seal (33) is provided between the end cap (31) and the retaining ring (32) to seal the gap between the end cap (31) and the retaining ring (32).

3. The axle box as described in claim 2, characterized in that, The contact seal (33) extends at least two sealing lips (331) from one end near the retaining ring (32), and at least two of the sealing lips (331) contact and abut against the retaining ring (32).

4. The axle box as described in claim 3, characterized in that, Two sealing lips (331) are provided. The contact seal (33) includes a connecting portion (332). The inner sealing lip (331) includes a transition portion (3311) and an abutment portion (3312). The abutment portion (3312) is connected to the connecting portion (332) through the transition portion (3311). The transition portion (3311) and the abutment portion (3312) are configured to abut against the retaining ring (32) when the pressure in the inner cavity (11) is greater than the external pressure of the axle box body (10).

5. The axle box as described in claim 4, characterized in that, The transition section (3311) has a small cross-sectional dimension in the middle and a large cross-sectional dimension at both ends.

6. The axle box as described in claim 4, characterized in that, The inner wall of the connection between the two sealing lips (331) is curved.

7. The axle box as described in claim 4, characterized in that, A sealing cavity (333) is formed between the two sealing lips (331).

8. The axle box as described in claim 2, characterized in that, The sealing assembly (30) further includes a support frame (34) which is bent and connected to the end cap (31), and at least a portion of the structure of the support frame (34) is embedded in the contact seal (33).

9. The axle box as described in any one of claims 1-8, characterized in that, The axle box also includes: A pressure detection component (40) is installed on the axle box body (10) for real-time detection of the pressure in the inner cavity (11); The control component is communicatively connected to the pressure detection component (40) and is used to control the air supply pipe (20) to supply air based on the pressure feedback from the pressure detection component (40) in real time.

10. A method for controlling the sealing of an axle box, applied to the axle box as described in any one of claims 1-9, characterized in that, The axle box sealing control method includes: Obtain the pressure in the inner cavity (11) and the external pressure of the axle box body (10); When the pressure difference between the inner cavity (11) and the external pressure of the axle box body (10) meets the preset conditions, the air supply pipe (20) is controlled to supply air to the inner cavity (11) so that the sealing assembly (30) switches from the first sealing state to the second sealing state, thereby improving the sealing level of the inner cavity (11).

11. A rail vehicle comprising an axle (50) and wheels, the wheels being disposed at both ends of the axle (50), characterized in that, It also includes the axle box as described in any one of claims 1-9, wherein the two ends of the axle (50) located outside the wheel are respectively supported in the axle box.

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