Axle box bearing for urban rail transit train

Abstract

The present invention discloses an axle box bearing for an urban rail transit train, which includes an outer bearing ring, an inner bearing ring assembly, a front sealing device, a rear sealing device, a front cover and a rear retaining ring. The inner bearing ring assembly includes a front bearing inner ring, a rear bearing inner ring, a middle spacer ring, two sets of rollers and two cages; the rear part of the outer circumferential surface of the front cover is provided with a first front labyrinth tooth groove; the rear retaining ring includes a rear cover and a rear sealing seat. The front sealing device includes a front metal sealing cover, a distance ring and a front rubber seal; the distance ring is arranged between the front cover and the front bearing inner ring, and the outer end of the distance ring extends forward with inner and outer sealing rings; the front rubber seal is directly formed on the front metal sealing cover and has a gap with the front end faces of the inner and outer sealing rings of the distance ring. The rear sealing device includes an inner metal sealing cover, an outer metal sealing cover and a rear rubber seal. A partition plate is arranged between the rear retaining ring and the rear bearing inner ring. The present invention can prevent fretting wear of the inner bearing ring, and can also prevent foreign objects from invading and grease leakage.

Description

Technical Field

[0001] The present invention relates to a journal bearing for an urban rail transit train. Background Art

[0002] With the development of urban rail transit, a large number of trains are put into operation. As the running gear of the train, the bogie runs at a relatively high speed and is subjected to complex forces between the wheel and the rail. The journal box of the bogie is an important component that converts rolling into translation, and the journal bearing is one of the most critical components in the journal box. The operating environment of the journal bearing is harsh, and it bears multi-dimensional impact forces transmitted from the wheel and the rail. Therefore, its quality requirements are extremely high.

[0003] The existing axial positioning during the installation of the journal bearing relies on direct positioning between the rear retaining ring and the front cover. However, due to the length limitation of the shaft, the front seal cover close to the front cover cannot make a complete labyrinth structure. Therefore, only the metal seal cover cooperates with the front cover for sealing. Two problems will occur in this structure during actual operation:

[0004] 1) Creep will occur between the end face of the front cover and the inner ring of the bearing and between the end face of the rear retaining ring and the inner ring of the bearing, resulting in wear. Although the installation fit between the inner ring of the bearing and the shaft is an interference fit, during actual operation, due to the deflection of the journal, there will still be a small amount of relative displacement between the inner ring of the bearing and the front cover and between the inner ring of the bearing and the rear retaining ring. After long-term operation, creep wear will occur. This kind of fretting wear will cause gaps between the front cover and the bearing and between the rear retaining ring and the bearing, increasing the axial clearance of the bearing, and will also allow impurities to enter the bearing interior, reducing the service life of the bearing.

[0005] 2) The structural sealing performance of the front cover and the metal seal cover is poor. During the operation of the bearing, centrifugal force is generated on the internal grease, causing the grease to be thrown outwards. The ordinary metal seal lacks a labyrinth structure, and oil leakage often occurs during actual operation. Summary of the Invention

[0006] The purpose of the present invention is to overcome the defects of the prior art and provide a journal bearing for an urban rail transit train, which can prevent fretting wear of the front inner ring and the rear inner ring of the bearing, reduce the bearing maintenance amount; and can also prevent foreign objects from invading during the working process of the bearing and prevent the grease inside the bearing from leaking.

[0007] The object of the present invention is achieved as follows: An axle box bearing for an urban rail transit train is a double-row tapered roller bearing installed on an axle and includes an outer bearing ring, an inner bearing ring assembly, a front sealing device, a rear sealing device, a front cover, and a rear retaining ring; the inner bearing ring assembly includes a front bearing inner ring, a rear bearing inner ring, a middle spacer ring provided between the front bearing inner ring and the rear bearing inner ring, two groups of rollers respectively arranged between the raceways of the front bearing inner ring and the rear bearing inner ring and the two raceways of the outer bearing ring, and two cages respectively arranged at intervals along the circumference to hold the two groups of rollers between the front bearing inner ring and the outer bearing ring and between the rear bearing inner ring and the outer bearing ring; the rear part of the outer circumferential surface of the front cover is provided with a plurality of first front labyrinth tooth grooves; the rear retaining ring includes a rear cover and a rear sealing seat extending from the front end surface of the rear cover; wherein,

[0008] The front sealing device includes a front metal sealing cover, a spacer ring, and a front rubber seal;

[0009] The front metal sealing cover includes an integrally formed front sealing cover inner ring, a front support inner ring, a front sealing cover middle ring, a front support outer ring, and a front sealing cover outer ring; the front sealing cover inner ring is arranged on the outer side of the rear part of the outer circumferential surface of the front cover; the width of the front sealing cover middle ring is greater than the width of the front sealing cover inner ring; the front sealing cover outer ring is fixedly connected to the front part of the inner circumferential surface of the outer bearing ring;

[0010] The spacer ring is arranged between the front cover and the front bearing inner ring, and a rear fixing ring sleeved on the front part of the outer circumferential surface of the front bearing inner ring extends backward at the outer end of the spacer ring, and an inner sealing ring and an outer sealing ring extend forward at the outer end of the spacer ring;

[0011] The front rubber seal is directly formed and fixed on the rear end surface of the front support inner ring of the front metal sealing cover, and there is a gap between the rear end surface of the front rubber seal and the front end surfaces of the inner sealing ring and the outer sealing ring of the spacer ring, and a plurality of second front labyrinth tooth grooves are provided on the rear end surface of the front rubber seal;

[0012] The rear sealing device includes an inner metal sealing cover, an outer metal sealing cover, and a rear rubber seal;

[0013] The inner metal sealing cover includes an integrally formed inner sealing cover inner ring, an inner support ring, and an inner sealing cover outer ring; the inner sealing cover inner ring is fixedly sleeved on the outer circumferential surface of the rear sealing seat of the rear retaining ring; the width of the inner sealing cover outer ring is less than the width of the inner sealing cover inner ring;

[0014] The outer metal sealing cover includes an integrally formed outer sealing cover outer ring, an outer support ring, and an outer sealing cover inner ring; the outer sealing cover outer ring is fixedly connected to the rear part of the inner circumferential surface of the outer bearing ring;

[0015] The rear rubber seal is directly formed and fixed on the outer metal seal cover. The rear rubber seal includes an integrally formed main support ring, a water shield, an upper sealing lip, and a lower sealing lip. The main support ring is located at the front side of the outer circle of the inner seal cover, and the outer end of the main support ring is fixedly connected to the rear end of the inner circle of the outer seal cover. The water shield is formed by extending backward from the outside of the rear end face of the main support ring and is located outside the outer circle of the inner seal cover. A plurality of first rear labyrinth grooves are provided on the inner circumferential surface of the water shield. The upper sealing lip and the lower sealing lip are both formed by extending backward from the inside of the rear end face of the main support ring, and the upper sealing lip is located inside the outer circle of the inner seal cover. The lower sealing lip is located inside the upper sealing lip, and the end of the lower sealing lip is in interference fit with the inner circle of the inner seal cover. A plurality of second rear sealing grooves are provided on the front part of the inner circumferential surface of the rear rubber seal.

[0016] A partition is provided between the rear retaining ring and the inner ring of the rear bearing.

[0017] For the axle box bearing of the urban rail transit train described above, a retaining ring extends outward from the front end of the outer sealing ring on the spacer ring; the outer end of the rear end face of the front rubber seal extends backward to form a front oil baffle located outside the retaining ring.

[0018] For the axle box bearing of the urban rail transit train described above, the spacer ring is made of glass fiber reinforced polyamide.

[0019] For the axle box bearing of the urban rail transit train described above, the longitudinal section of the partition is L-shaped and includes a ring part and a circular part. The ring part is provided between the front end face of the rear retaining ring and the rear end face of the inner ring of the rear bearing, and the circular part of the partition is fixed on the inner circumferential surface of the rear retaining ring.

[0020] For the axle box bearing of the urban rail transit train described above, the partition is made of glass fiber reinforced polyamide.

[0021] For the axle box bearing of the urban rail transit train described above, a metal skeleton is provided inside the main support ring of the rear rubber seal.

[0022] The axle box bearing of the urban rail transit train of the present invention has the following characteristics:

[0023] 1) The front sealing device adopts a non-contact sealing structure, which not only includes a front metal seal cover and a front rubber seal, but also includes a spacer ring. The spacer ring can not only isolate the inner ring of the front bearing from the front cover, but also the inner sealing ring, the outer sealing ring and the retaining ring on the spacer ring cooperate with the front rubber seal to form a labyrinth, increasing the movement stroke of the grease, making it not easy for the grease to be thrown out. The grease entering the front internal space of the bearing can accumulate at the notch formed between the inner sealing ring and the outer sealing ring, blocking the outlet of the front labyrinth cavity, preventing grease leakage inside and preventing foreign objects from entering outside.

[0024] 2) The rear sealing device adopts a partial contact sealing structure. The labyrinth channels and pressure drop of the first labyrinth cavity formed by the water baffle, the outer ring of the inner sealing cover, and the upper sealing lip jointly prevent foreign matters such as external dust and moisture from entering the bearing interior; the second labyrinth cavity formed by the lower sealing lip, the second rear sealing tooth groove, and the inner ring of the inner sealing cover can effectively seal the lubricating grease inside the bearing to prevent its leakage, and has a good sealing and dust-proof effect; there is an included angle between the lower sealing lip and the inner ring of the inner sealing cover, and the contact end of the lower sealing lip and the inner ring of the inner sealing cover is a sharp corner structure, which can make the radial force generated by the lower sealing lip be distributed in a sharp corner shape, which is beneficial to reducing frictional heat and stabilizing the lubricating oil film;

[0025] 3) A partition plate is used to isolate the rear bearing inner ring and the rear retaining ring, and a spacer ring is used to isolate the front bearing inner ring and the front cover, which can prevent fretting wear of the front bearing inner ring and the rear bearing inner ring and reduce bearing maintenance. Both the partition plate and the spacer ring are made of glass fiber-reinforced polyamide, which has better strength and wear resistance compared with metals, and the partition plate and the spacer ring can be installed without tooling. Description of the Drawings

[0026] Figure 1 is the longitudinal sectional view of the axle box bearing of the urban rail transit train of the present invention;

[0027] Figure 2 is Figure 1 the enlarged view of part A in

[0028] Figure 3 is Figure 1 the enlarged view of part B in Detailed Embodiment

[0029] The present invention will be further described below in conjunction with the drawings.

[0030] Please refer to Figures 1 to 3 , the axle box bearing of the urban rail transit train of the present invention is a double-row tapered roller bearing installed on the axle 10 and includes a bearing outer ring 1, a bearing inner ring assembly, a front sealing device 3, a rear sealing device 4, a front cover 5, a rear retaining ring 6, and a partition plate 7.

[0031] The bearing inner ring assembly includes a front bearing inner ring 21, a rear bearing inner ring 23, a middle spacer 22 provided between the front bearing inner ring 21 and the rear bearing inner ring 23, two groups of rollers 24 provided in a one-to-one correspondence between the raceways of the front bearing inner ring 21 and the rear bearing inner ring 23 and the two raceways of the bearing outer ring 1, and two cages 25 provided in a one-to-one correspondence to arrange the two groups of rollers 24 at intervals along the circumference and hold the two groups of rollers 24 between the front bearing inner ring 21 and the bearing outer ring 1 and between the rear bearing inner ring 23 and the bearing outer ring 1.

[0032] A number of first front labyrinth grooves 50 are provided at the rear of the outer circumferential surface of the front cover 5.

[0033] The rear retaining ring 6 includes a rear cover 61 and a rear sealing seat 62 extending from the front end face of the rear cover 61.

[0034] The front sealing device 3 includes a front metal sealing cover 31, a spacer ring 32, and a front rubber seal 33; among them,

[0035] The front metal sealing cover 31 includes a front sealing cover inner ring 311, a front support inner ring 312, a front sealing cover middle ring 313, a front support outer ring 314, and a front sealing cover outer ring 315; the front sealing cover inner ring 311 is provided on the outer side of the rear part of the outer circumferential surface of the front cover 5; the front support inner ring 312 is formed by extending outward from the front end of the front sealing cover inner ring 311; the front sealing cover middle ring 313 is formed by extending backward from the outer end of the front support inner ring 312, and the width of the front sealing cover middle ring 313 is greater than the width of the front sealing cover inner ring 311; the front support outer ring 314 is formed by extending outward from the rear end of the front sealing cover middle ring 313; the front sealing cover outer ring 315 is formed by extending backward from the outer end of the front support outer ring 314, and the front sealing cover outer ring 315 is fixedly connected to the front part of the inner circumferential surface of the bearing outer ring 1. A front protrusion 310 is provided at the rear end of the front sealing cover outer ring 315, and a front groove is provided on the front part of the inner circumferential surface of the bearing outer ring 1 corresponding to the front protrusion 310. After the front protrusion 310 and the front groove are matched, they are locked to prevent the front metal sealing cover 31 from coming off during use;

[0036] The spacer ring 32 is made of glass fiber reinforced polyamide; the spacer ring 32 is provided between the rear end face of the front cover 5 and the front end face of the front bearing inner ring 21. A rear fixing ring 321 that sleeves on the front part of the outer circumferential surface of the front bearing inner ring 21 extends backward from the outer end of the spacer ring 32. An inner sealing ring 322 and an outer sealing ring 323 extend forward from the outer end of the spacer ring 32, and the front ends of the inner sealing ring 322 and the outer sealing ring 323 are close to the rear end face of the front support inner ring 312; a retaining ring 324 extends outward from the front end of the outer sealing ring 323, and there is a gap between the retaining ring 324 and the rear end face of the front rubber seal 33;

[0037] The front rubber seal 33 is directly formed and fixed on the rear end face of the front support inner ring 312 of the front metal seal cover 31. There is a gap between the rear end face of the front rubber seal 33 and the front end faces of the inner sealing ring 322 and the outer sealing ring 323 of the spacer ring 32. A number of second front labyrinth tooth grooves 330 are provided on the rear end face of the front rubber seal 33. The outer end of the rear end face of the front rubber seal 33 extends backward to form a front oil baffle 331, and the front oil baffle 331 is located outside the retaining ring 324 on the spacer ring 32. A front labyrinth cavity 300 is formed among the front oil baffle 331, the retaining ring 324, the outer sealing ring 323, the second front labyrinth tooth grooves 330, the inner sealing ring 322, the inner ring 311 of the front seal cover, and the first front labyrinth tooth grooves 50.

[0038] The rear sealing device 4 includes an inner metal seal cover 41, an outer metal seal cover 42, and a rear rubber seal 43. Among them,

[0039] The inner metal seal cover 41 includes an inner ring 411 of the seal cover, an inner support ring 412, and an outer ring 413 of the seal cover. The inner ring 411 of the seal cover is fixedly sleeved on the outer circumferential surface of the rear seal seat 62 of the rear retaining ring 6. The inner support ring 412 is formed by extending outward from the rear end of the inner ring 411 of the seal cover. The outer ring 413 of the seal cover is formed by extending forward from the outer end of the inner support ring 412, and the width of the outer ring 413 of the seal cover is smaller than the width of the inner ring 411 of the seal cover.

[0040] The outer metal seal cover 42 includes an outer ring 421 of the seal cover, an outer support ring 422, and an inner ring 423 of the seal cover. The outer ring 421 of the seal cover is fixedly connected to the rear part of the inner circumferential surface of the bearing outer ring 1. The outer support ring 422 is formed by extending inward from the rear end of the outer ring 421 of the metal seal cover. The inner ring 423 of the seal cover is formed by extending backward from the inner end of the outer support ring 422. A rear protrusion 420 is provided at the front end of the outer ring 421 of the seal cover, and a rear groove is correspondingly provided on the rear part of the inner circumferential surface of the bearing outer ring 1. After the rear protrusion 420 and the rear groove are matched, they are locked to prevent the outer metal seal cover 42 from coming off during use.

[0041] The rear rubber seal 43 is directly formed and fixed on the outer metal seal cover 42. The rear rubber seal 43 includes a main support ring 430, a water shield 431, an upper sealing lip 432 and a lower sealing lip 433. The outer end of the main support ring 430 is fixedly connected to the rear end of the inner ring 423 of the outer seal cover. A metal skeleton 4300 is provided inside the main support ring 430, and the metal skeleton 4300 can prevent the rear rubber seal 43 from undergoing plastic deformation. The water shield 431 is formed by extending backward from the outside of the rear end face of the main support ring 430 and is located outside the outer ring 413 of the inner seal cover. A plurality of first rear labyrinth tooth grooves 4310 are provided on the inner circumferential surface of the water shield 431. The upper sealing lip 432 and the lower sealing lip 433 are both formed by extending backward from the inside of the rear end face of the main support ring 430. The upper sealing lip 432 is located inside the outer ring 413 of the inner seal cover, and a first rear labyrinth cavity 401 is formed between the water shield 431, the outer ring 413 of the inner seal cover and the upper sealing lip 432. The lower sealing lip 433 is located inside the upper sealing lip 432. There is an included angle between the end of the lower sealing lip 433 and the inner ring 411 of the inner seal cover, and the contact end of the lower sealing lip 433 and the inner ring 411 of the inner seal cover is a sharp corner structure. The end of the lower sealing lip 433 and the inner ring 411 of the inner seal cover are in interference fit. The lower sealing lip 433 and the inner ring 411 of the inner seal cover are arranged in such a structure that the radial force generated by the lower sealing lip 433 is distributed in a sharp corner shape, which is beneficial to reducing frictional heat and stabilizing the lubricating oil film. A plurality of second rear seal tooth grooves 430 are provided at the front part of the inner circumferential surface of the rear rubber seal 43, and a second rear labyrinth cavity 402 is formed between the lower sealing lip 433, the second rear seal tooth grooves 430 and the inner ring 411 of the inner seal cover.

[0042] The partition plate 7 is provided between the front end face of the rear retaining ring 6 and the rear end face of the rear bearing inner ring 23. The partition plate 7 is made of glass fiber reinforced polyamide. The longitudinal section of the partition plate 7 is L-shaped and includes a ring part 71 and a ringlet part 72. The ring part 71 is provided between the front end face of the rear retaining ring 6 and the rear end face of the rear bearing inner ring 23, and the ringlet part 72 of the partition plate 7 is fixed on the inner circumferential surface of the rear retaining ring 6.

[0043] The axle box bearing of the urban rail transit train of the present invention, wherein the front sealing device 3 is a non-contact sealing structure, during installation, the interference connection between the front metal sealing cover 31 of the front sealing device 3 and the bearing outer ring 1 can increase the reliability of the assembly of the front sealing device 3; when the bearing is working, the front metal sealing cover 31 and the front rubber seal 33 connected to the bearing outer ring 1 are stationary, and the distance ring 32 rotates with the front bearing inner ring 21; the front metal sealing cover 31 can increase the stiffness of the seal to prevent the front rubber seal 33 from plastic deformation. The distance ring 32 has the characteristics of high strength, toughness and good wear resistance. The distance ring 32 can not only isolate the front bearing inner ring 21 from the front cover 5, but also the inner seal ring 322, outer seal ring 323 and retaining ring 324 on the distance ring 32 cooperate with the front rubber seal 33 to form a labyrinth, increase the movement stroke of grease, and make it difficult for grease to be thrown out. The gap formed between the inner seal ring 322 and the outer seal ring 323 can make the grease entering the internal space of the bearing accumulate, block the outlet of the front labyrinth cavity 300, prevent grease from leaking out internally, and prevent foreign matter from entering externally. The distance ring 32 has no mating surface, is easy to install, and can ensure its performance without replacement during the maintenance period of the bearing. The oil shield 331 on the front rubber seal 33 can prevent the grease distributed in the front internal space of the bearing from directly entering the front labyrinth cavity 300. This non-contact sealing structure is not easy to heat up compared with the contact sealing structure.

[0044] The axle box bearing of the urban rail transit train of the present invention, wherein the rear sealing device 4 is a local contact type sealing structure. When the bearing is working, the inner metal sealing cover 41 and the subsequent retaining ring 6 rotate at high speed, and a pressure drop is formed between the first rear labyrinth chamber 401 and the external environment. The labyrinth channel and the pressure drop of the first rear labyrinth chamber 401 jointly prevent foreign matter (dust, moisture, etc.) from entering the interior of the bearing; the second rear sealing tooth groove 430 increases the resistance to the flow of the lubricating grease leakage in the second rear labyrinth chamber 402, so that the pressure difference causing the lubricating grease leakage is lost sharply. When the pressure difference at both ends of the second rear labyrinth chamber 402 is zero, the lubricating grease can be effectively sealed to prevent it from leaking. When assembling the rear sealing device 4, a certain amount of lubricating grease is first injected into the second rear labyrinth cavity 402. Firstly, it can reduce the initial starting torque of the rear sealing device 4. Secondly, it can form a stable oil film between the lower sealing lip 433 and the rear retaining ring 6 here to prevent the flow of lubricating grease here, thereby achieving the purpose of internal oil sealing; the interference fit between the lower sealing lip 433 and the inner ring 411 of the inner sealing cover will generate a certain radial force to compensate for the eccentricity of the rear retaining ring 6, and then compensate for the eccentricity of the main shaft 10.

[0045] The axle box bearing of the urban rail transit train of the present invention, wherein the partition 7 isolates the rear bearing inner ring 23 and the rear retaining ring 6, and the distance ring 32 isolates the front bearing inner ring 21 and the front cover 5, can prevent the front bearing inner ring 21 and the rear bearing inner ring 23 from micro-motion wear and reduce the bearing maintenance.

[0046] The above embodiments are only for illustrating the present invention and not for limiting the present invention. Those skilled in the relevant technical fields can also make various changes or modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions should also fall within the scope of the present invention and should be defined by each claim.

Claims

1. An axle box bearing for an urban rail transit train, which is a double-row tapered roller bearing installed on an axle and includes an outer bearing ring, an inner bearing ring assembly, a front sealing device, a rear sealing device, a front cover and a rear retaining ring; the inner bearing ring assembly includes a front bearing inner ring, a rear bearing inner ring, a middle spacer ring arranged between the front bearing inner ring and the rear bearing inner ring, two groups of rollers respectively arranged between the raceways of the front bearing inner ring and the rear bearing inner ring and the two raceways of the outer bearing ring, and two cages respectively arranging the two groups of rollers at intervals along the circumference and holding the two groups of rollers between the front bearing inner ring and the outer bearing ring and between the rear bearing inner ring and the outer bearing ring; the rear part of the outer circumferential surface of the front cover is provided with a plurality of first front labyrinth grooves; the rear retaining ring includes a rear cover and a rear sealing seat extending from the front end surface of the rear cover; it is characterized in that, The front sealing device includes a front metal sealing cover, a distance ring and a front rubber seal; The front metal sealing cover includes an integrally formed front sealing cover inner ring, a front support inner ring, a front sealing cover middle ring, a front support outer ring and a front sealing cover outer ring; the front sealing cover inner ring is arranged on the outer side of the rear part of the outer circumferential surface of the front cover; the width of the front sealing cover middle ring is greater than the width of the front sealing cover inner ring; the front sealing cover outer ring is fixedly connected to the front part of the inner circumferential surface of the outer bearing ring; The distance ring is arranged between the front cover and the front bearing inner ring. The outer end of the distance ring extends backward to form a rear fixing ring sleeved on the front part of the outer circumferential surface of the front bearing inner ring. The outer end of the distance ring extends forward to form an inner sealing ring and an outer sealing ring; the front end of the outer sealing ring on the distance ring extends outward to form a retaining ring; The front rubber seal is directly formed and fixed on the rear end surface of the front support inner ring of the front metal sealing cover. There is a gap between the rear end surface of the front rubber seal and the front end surfaces of the inner sealing ring and the outer sealing ring of the distance ring. A plurality of second front labyrinth grooves are arranged on the rear end surface of the front rubber seal; the outer end of the rear end surface of the front rubber seal extends backward to form a front oil retaining cover located outside the retaining ring; The rear sealing device includes an inner metal sealing cover, an outer metal sealing cover and a rear rubber seal; The inner metal sealing cover includes an integrally formed inner sealing cover inner ring, an inner support ring and an inner sealing cover outer ring; the inner sealing cover inner ring is fixedly sleeved on the outer circumferential surface of the rear sealing seat of the rear retaining ring; the width of the inner sealing cover outer ring is less than the width of the inner sealing cover inner ring; The outer metal sealing cover includes an integrally formed outer sealing cover outer ring, an outer support ring and an outer sealing cover inner ring; the outer sealing cover outer ring is fixedly connected to the rear part of the inner circumferential surface of the outer bearing ring; The rear rubber seal is directly formed and fixed on the outer metal seal cover. The rear rubber seal includes an integrally formed main support ring, a water shield, an upper sealing lip and a lower sealing lip. The main support ring is located at the front side of the outer circle of the inner seal cover. The outer end of the main support ring is fixedly connected to the rear end of the inner circle of the outer seal cover, and a metal skeleton is provided inside the main support ring. The water shield is formed by extending backward from the outside of the rear end face of the main support ring and is located outside the outer circle of the inner seal cover. A plurality of first rear labyrinth tooth grooves are provided on the inner circumferential surface of the water shield. The upper sealing lip and the lower sealing lip are both formed by extending backward from the inside of the rear end face of the main support ring, and the upper sealing lip is located inside the outer circle of the inner seal cover. The lower sealing lip is located inside the upper sealing lip, and the end of the lower sealing lip is in interference fit with the inner circle of the inner seal cover. A plurality of second rear sealing tooth grooves are provided at the front part of the inner circumferential surface of the rear rubber seal. A partition is provided between the rear retaining ring and the inner ring of the rear bearing. The longitudinal section of the partition is L-shaped and includes a ring portion and a loop portion. The ring portion is provided between the front end face of the rear retaining ring and the rear end face of the inner ring of the rear bearing, and the loop portion of the partition is fixed on the inner circumferential surface of the rear retaining ring.

2. The axle box bearing of an urban rail transit train according to claim 1, characterized in that, The material of the spacer ring is glass fiber reinforced polyamide.

3. The axle box bearing of an urban rail transit train according to claim 1, characterized in that, The material of the partition is glass fiber reinforced polyamide.

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