Air pressure balance type four-row tapered roller bearing

Abstract

The invention relates to the technical field of bearings, in particular to an air pressure balance type four-row tapered roller bearing which comprises an inner ring set and an outer ring set, a mounting gap is formed between the outer side peripheral wall of the inner ring set and the inner side peripheral wall of the outer ring set, four rows of roller mounting grooves are formed in the mounting gap, and a plurality of tapered rollers are rotationally assembled in the roller mounting grooves; an annular retainer is arranged in each row of roller mounting grooves, the two ends of the mounting gap are sealed through two oil seal sets respectively, a plurality of inner vent holes are formed in the inner ring set in the radial direction, a plurality of outer vent holes are formed in the outer ring set in the radial direction, and air pressure balance holes are formed in the two end faces of the outer ring set. And the air pressure balance hole, the inner vent hole and the outer vent hole are all communicated with the mounting gap and are all filled with breathable and grease-tight materials. The leakage phenomenon caused by unbalanced air pressure is not prone to occurring, the breathable and grease-impermeable material further has the effects of blocking grease permeation and preventing the oil mixing phenomenon from occurring, the bearing is not prone to being damaged, and the service life of the bearing is prolonged.

Description

Technical Field

[0001] The present application relates to the technical field of bearings, and in particular to a gas pressure balanced four-row tapered roller bearing. Background Art

[0002] Four-row tapered roller bearings are successfully used in bearing arrangements in rolling mills around the world where steel is rolled at low to medium speeds. Due to their design, these bearings can accommodate the axial loads that occur in such applications in addition to the radial loads, and generally no additional thrust bearing is required in the bearing arrangement. This means that the roll journals can be relatively short and the bearing housings on both sides of the roll can be of the same design. Due to the design of four-row tapered roller bearings, these bearings must be mounted in the roll chocks as complete bearings.

[0003] For example, the Chinese patent application number: CN201010514878.9 discloses a four-row tapered roller bearing without a spacer ring, including an outer ring, a second outer ring, an inner ring, a retainer and tapered rollers; the bearing has two single-raceway outer rings and a double-raceway second outer ring between the two outer sides, and two double-raceway inner rings on the two inner sides, tapered rollers are arranged between the inner ring and the outer ring and the second outer ring, and each tapered roller is fixed by a retainer.

[0004] With respect to the above-mentioned related technologies, the inventor believes that there are the following technical defects that need to be improved: In the actual application of common four-row tapered roller bearings, the temperature of the bearings will rise during operation, resulting in high temperature and high pressure inside the bearings. The internal grease is easy to overflow, and even the sealing ring on the end face side is flushed out by the internal high pressure, causing bearing damage. When the equipment stops working, the bearing temperature continues to return to normal temperature, and negative pressure is formed inside, allowing external pollutants and particles to enter the bearing, accelerating the failure of grease contamination and internal wear of the bearing, and significantly shortening its service life. Summary of the invention

[0005] The present application provides a gas pressure balanced four-row tapered roller bearing to improve the following technical problems: In the actual application of common four-row tapered roller bearings, the internal grease is easy to overflow, causing bearing damage, and negative pressure is easy to form inside, allowing external pollutants and particles to enter the bearing, accelerating grease contamination failure and internal bearing wear.

[0006] The present application provides a gas pressure balanced four-row tapered roller bearing, which adopts the following technical solution: A pressure-balanced four-row tapered roller bearing comprises an inner ring group and an outer ring group, an installation gap is arranged between the outer circumferential wall of the inner ring group and the inner circumferential wall of the outer ring group, four rows of roller installation grooves are arranged in the installation gap, a plurality of tapered rollers are rotatably mounted in the roller installation grooves, an annular retainer for relatively fixing the tapered rollers is arranged in each row of the roller installation grooves, two ends of the installation gap are sealed respectively by two groups of oil seal groups, a plurality of inner vent holes are arranged radially on the inner ring group, a plurality of outer vent holes are arranged radially on the outer ring group, and pressure-balanced holes are arranged on both end surfaces of the outer ring group, the pressure-balanced holes, the inner vent holes, and the outer vent holes are all connected to the installation gap and are filled with air-permeable and grease-proof materials inside, the number of the outer vent holes is between 4 and 14, and the plurality of the outer vent holes are symmetrically spaced around the central axis of the bearing, and the spacing between adjacent inner vent holes is 0.2 to 0.4 times the radius of the inner ring group.

[0007] In an achievable technical solution of the present application, the inner surface of the inner ring group is provided with a spiral grease groove, and each circle of the spiral grease groove corresponds to 3-8 inner ventilation holes arranged evenly at intervals.

[0008] In a feasible technical solution of the present application, the inner vent holes on adjacent circles of the spiral grease grooves are arranged in a staggered manner.

[0009] In an achievable technical solution of the present application, the four rows of tapered rollers divide the bearing into load zone one, load zone two, load zone three and load zone four, a portion of the external air holes are evenly spaced on a dividing line between the load zone one and the load zone two, the remaining external air holes are evenly spaced on a dividing line between the load zone three and the load zone four, and there are 4-7 external air holes corresponding to each of the two dividing lines.

[0010] In a feasible technical solution of the present application, a first high-carbon alloy steel sleeve is arranged in the inner vent hole, a second high-carbon alloy steel sleeve is arranged in the outer vent hole, and the air-permeable and grease-proof material is filled in the first high-carbon alloy steel sleeve and the second high-carbon alloy steel sleeve.

[0011] In an achievable technical solution of the present application, the breathable and grease-impermeable material is a nano-coated sponge, a polypropylene nano-composite material or a microporous PET breathable material.

[0012] In an achievable technical solution of the present application, the inner ring group includes a first inner ring and a second inner ring, the first inner ring and the second inner ring respectively correspond to two rows of tapered rollers, an inner sealing groove is provided at the junction of the inner side walls of the first inner ring and the second inner ring, and an inner diameter sealing ring is embedded and fixed in the inner sealing groove.

[0013] In an achievable technical solution of the present application, the inner diameter sealing ring includes an inner ring skeleton and an inner ring rubber layer, the inner ring rubber layer is wrapped around the outer surface of the inner ring skeleton, and a notch is provided at one corner of the inner ring rubber layer to allow a corner of the inner ring skeleton to leak out.

[0014] In an achievable technical solution of the present application, the outer ring group includes a central outer ring, two side outer rings, two end retaining rings and two outer spacer rings, one of the outer spacer rings is clamped between one end of the central outer ring and one of the side outer rings, the other outer spacer ring is clamped between the other end of the central outer ring and the other side outer ring, the two end retaining rings are respectively located at the two end surfaces of the bearing, the air pressure balance hole is arranged on the end retaining rings, the external vent hole is arranged on the outer spacer rings, and the oil seal group is installed between the inner side of the end retaining rings and the outer side of the inner ring group.

[0015] In an achievable technical solution of the present application, the oil seal group includes an oil seal skeleton, an oil seal rubber layer and a tightening spring, the oil seal rubber layer is wrapped around the outer side surface of the oil seal skeleton, an annular groove corresponding to the tightening spring is provided on the oil seal rubber layer, one end surface of the oil seal rubber layer is pressed against the outer circumferential wall of the inner ring group through the tightening spring, and the other end surface of the oil seal rubber layer is pressed against the inner circumferential wall of the outer ring group through the oil seal skeleton.

[0016] In summary, the present application includes at least one of the following beneficial technical effects: By adding air pressure balance holes, multiple internal air holes, and multiple external air holes, all of the above holes are connected in series in combination with the installation gap. Due to the good air permeability of the air-permeable and grease-impermeable material, the air pressure on the inner side, outer side, and end face of the bearing can be kept consistent, that is, the air pressure balance state is always maintained during use, so that the grease in the bearing installation gap, the grease on the inner peripheral wall of the bearing, and the grease on the outer peripheral wall of the bearing are not easy to leak due to the air pressure difference, and external pollutants and particles are not easy to enter the bearing due to the pressure difference after cooling, which effectively prevents the internal grease from contaminating and failing and the internal wear of the bearing. In addition, the air-permeable and grease-impermeable material also has the characteristic of blocking grease penetration, which is not easy to cause the grease in the bearing installation gap, the grease on the inner peripheral wall of the bearing, and the grease on the outer peripheral wall of the bearing to cross-link, making the bearing not easy to be damaged, and greatly extending the service life of the bearing. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 It is a schematic structural diagram of a gas pressure balanced four-row tapered roller bearing according to an embodiment of the present application.

[0019] Figure 2 Schematic diagram of the structure of the oil seal group in the embodiment of the present application.

[0020] Figure 3 It is a schematic diagram of the structure of the inner diameter sealing ring in the embodiment of the present application.

[0021] Figure 4 It is a schematic diagram of the structure of the first high carbon alloy steel sleeve and its interior in the embodiment of the present application.

[0022] Figure 5 It is a schematic diagram of the structure of the second high carbon alloy steel sleeve and its interior in the embodiment of the present application.

[0023] Description of reference numerals: 1. Inner ring group; 11. First inner ring; 12. Second inner ring; 13. Inner diameter sealing ring; 131. Inner ring skeleton; 132. Inner ring rubber layer; 1321. Notch; 2. Outer ring assembly; 21. Center outer ring; 22. Side outer ring; 23. End retaining ring; 24. Outer spacer ring; 25. O-ring; 3. Tapered roller; 4. Ring cage; 5. Oil seal assembly; 51. Oil seal frame; 52. Oil seal rubber layer; 53. Tightening spring; 6. Breathable and grease-proof material; 7. The first high carbon alloy steel sleeve; 8. Second high carbon alloy steel sleeve; 100, spiral grease groove; 200, installation clearance; 300, internal vent hole; 400, external vent hole; 500, air pressure balance hole. DETAILED DESCRIPTION

[0024] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0025] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0026] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0027] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0028] The following is combined with Figure 1-5 This application is described in further detail.

[0029] The present application embodiment discloses a gas pressure balanced four-row tapered roller bearing. Figure 1-5 The air pressure balanced four-row tapered roller bearing comprises an inner ring group 1 and an outer ring group 2. An installation gap 200 is arranged between the outer peripheral wall of the inner ring group 1 and the inner peripheral wall of the outer ring group 2. The installation gap 200 has four rows of roller installation grooves. A plurality of tapered rollers 3 are rotatably mounted in the roller installation grooves. An annular retainer 4 for relatively fixing the tapered rollers 3 is arranged in each row of roller installation grooves. The two ends of the installation gap 200 are sealed by two groups of oil seal groups 5 respectively. A plurality of inner vent holes 300 are arranged radially on the inner ring group 1. A plurality of outer ventilation holes 400 are radially arranged on the outer ring group 2, and air pressure balance holes 500 are arranged on both end surfaces of the outer ring group 2. The air pressure balance holes 500, the inner ventilation holes 300, and the outer ventilation holes 400 are all connected to the installation gap 200 and are filled with air-permeable and grease-proof materials 6 inside. The number of the outer ventilation holes 400 is between 4 and 14, and the plurality of outer ventilation holes 400 are symmetrically spaced around the central axis of the bearing, and the spacing between adjacent inner ventilation holes 300 is 0.2 to 0.4 times the radius of the inner ring group 1.

[0030] In order to ensure that more grease can be loaded on the inner peripheral wall of the bearing to improve the lubrication characteristics and reduce wear, the inner surface of the inner ring group 1 is provided with a spiral grease groove 100, and each circle of the spiral grease groove 100 corresponds to 3-8 evenly spaced inner vents 300, wherein the inner vents 300 on adjacent circles of the spiral grease groove 100 are staggered. In this embodiment, the open end of the spiral grease groove 100 does not extend to the end of the inner ring group 1. In other embodiments, according to specific needs, the open end of the spiral grease groove 100 can also extend to both ends of the inner ring group 1.

[0031] The multiple internal ventilation holes 300 arranged in a spiral and staggered manner are more evenly distributed, which is conducive to the inner wall of the bearing being fully connected with the installation gap 200 and maintaining a ventilated state. At the same time, the structural distribution is relatively uniform, which has less impact on the structural strength of the inner ring group 1.

[0032] In this embodiment, the tapered roller 3 divides the bearing into load zone 1, load zone 2, load zone 3 and load zone 4. A portion of the external vent holes 400 are evenly spaced on the dividing line between load zone 1 and load zone 2, and the remaining external vent holes 400 are evenly spaced on the dividing line between load zone 3 and load zone 4, and there are 4-7 external vent holes 400 on each of the two dividing lines.

[0033] The outer vent hole 400 and the inner vent hole 300 designed as above are more convenient for the processing and manufacturing of the bearing before assembly, and the outer vent hole 400 can also be used as an oil filling hole before being filled with the breathable and grease-proof material 6. It is just that after assembly, the breathable and grease-proof material 6 is filled for sealing, so that one hole can be used for multiple purposes.

[0034] In order to reduce the adverse effect of drilling on the structural strength of the inner ring group 1 and the outer ring group 2, a first high-carbon alloy steel sleeve 7 is arranged in the inner vent hole 300, and a second high-carbon alloy steel sleeve 8 is arranged in the outer vent hole 400. The air-permeable and grease-proof material 6 is filled in the first high-carbon alloy steel sleeve 7 and the second high-carbon alloy steel sleeve 8. In order to adapt to the structure of the spiral grease groove 100, the inner end of the first high-carbon alloy steel sleeve 7 is designed as a concave arc structure, see Figure 4 Before interference fitting the first high carbon alloy steel sleeve 7 and the second high carbon alloy steel sleeve 8, the first high carbon alloy steel sleeve 7 and the second high carbon alloy steel sleeve 8 may be filled with an air permeable and grease-proof material 6 in advance to reduce the difficulty of manufacturing and assembly.

[0035] In this embodiment, the breathable and grease-impermeable material 6 is a nano-coated sponge, a polypropylene nano-composite material or a microporous PET breathable material. The above material selection not only has good chemical stability and is not easily deteriorated due to high temperature generated by friction, but also has good air permeability and good barrier properties to grease.

[0036] In this embodiment, based on the existing production equipment, in order to reduce the difficulty of producing the inner ring group 1, the inner ring group 1 includes a first inner ring 11 and a second inner ring 12, the first inner ring 11 and the second inner ring 12 correspond to two rows of tapered rollers 3 respectively, and an inner sealing groove is provided at the connection between the inner side walls of the first inner ring 11 and the second inner ring 12, and an inner diameter sealing ring 13 is embedded and fixed in the inner sealing groove. The above-mentioned split inner ring group 1 is not only easy to produce and assemble, but also improves the inner side sealing of the bearing by adding the inner sealing groove and the inner diameter sealing ring 13.

[0037] The inner diameter seal ring 13 includes an inner ring frame 131 and an inner ring rubber layer 132. The inner ring rubber layer 132 is wrapped around the outer surface of the inner ring frame 131, and a notch 1321 is provided at one corner of the inner ring rubber layer 132 to allow one corner of the inner ring frame 131 to leak out. The inner diameter seal ring 13 designed as above is not only simple to manufacture, but also has a firm and stable structure and is easy to assemble. Moreover, the design of the notch 1321 can provide a certain activity space for the inner diameter seal ring 13, effectively avoiding structural damage caused by excessive assembly of the inner diameter seal ring 13.

[0038] The inner ring rubber layer 132 should meet the requirements of JB / T6639 standard, and the inner ring skeleton 131 and the inner ring rubber layer 132 should be firmly bonded, wherein the inner ring skeleton 131 is deburred and the surface is phosphated for rust prevention, and the surface roughness of the inner ring rubber layer 132 should reach Ra1.6.

[0039] In this embodiment, based on the existing production equipment, in order to reduce the difficulty of producing the outer ring group 2, the outer ring group 2 includes a central outer ring 21, two side outer rings 22, two end retaining rings 23 and two outer spacers 24, one outer spacer 24 is sandwiched between one end of the central outer ring 21 and one side outer ring 22, and the other outer spacer 24 is sandwiched between the other end of the central outer ring 21 and the other side outer ring 22. The two end retaining rings 23 are respectively located at the two end surfaces of the bearing, the air pressure balance hole 500 is provided on the end retaining ring 23, the outer vent hole 400 is provided on the outer spacer 24, and the oil seal group 5 is installed between the inner side of the end retaining ring 23 and the outer side of the inner ring group 1. The air pressure balance hole 500 is an L-shaped structure, and the inner end of the air pressure balance hole 500 does not have any contact with the oil seal group 5 to ensure a good air permeability environment. An O-ring 25 is also embedded on the outer peripheral wall of the end retaining ring 23 to seal the grease between the outer peripheral wall of the bearing and the external component as much as possible.

[0040] The above-mentioned split outer ring group 2 is not only easy to manufacture and assemble, but also reduces the possibility of oil leakage of the bearing by adding the oil seal group 5.

[0041] In this embodiment, the oil seal group 5 includes an oil seal skeleton 51, an oil seal rubber layer 52 and a clamping spring 53. The oil seal rubber layer 52 is wrapped around the outer side of the oil seal skeleton 51. The oil seal rubber layer 52 is provided with an annular groove corresponding to the clamping spring 53. One end face of the oil seal rubber layer 52 is pressed against the outer peripheral wall of the inner ring group 1 through the clamping spring 53, and the other end face of the oil seal rubber layer 52 is pressed against the inner peripheral wall of the outer ring group 2 through the oil seal skeleton 51. The above oil seal group 5 is not only simple in structure, firmly assembled and not easy to loosen, but also has a good sealing effect on grease, further reducing the possibility of oil leakage of the bearing.

[0042] The oil seal rubber layer 52 and the inner ring rubber layer 132 should meet the requirements of JB / T6639 standard, and the oil seal skeleton 51 and the oil seal rubber layer 52 should be firmly bonded, wherein the oil seal skeleton 51 is deburred and the surface is phosphated for rust prevention, and the surface roughness of the oil seal rubber layer 52 should reach Ra1.6.

[0043] Some parameters of the air pressure balanced four-row tapered roller bearing of the embodiment of the present application are as follows: Dimension accuracy: Class2, rotation accuracy: P5, rated load: Cr=1670KN Cor=3930KN, axial clearance: 0.36-0.45mm, radial clearance: 0.096-0.12mm, filling grease: Mobilith SHC 460 (0.57±0.03Kg), the outer wall of the outer ring group 2 is divided into four grades and marked with Roman numerals Ⅰ, Ⅱ, Ⅲ, and Ⅳ to distinguish the four load zones.

[0044] The beneficial technical effects of the air pressure balanced four-row tapered roller bearing of the embodiment of the present application are roughly as follows: By adding an air pressure balance hole 500, multiple internal air holes 300, and multiple external air holes 400, and combining the series effect of the installation gap 200 to connect all the above holes, due to the good air permeability of the air-permeable and grease-impermeable material 6, the air pressure on the inner side, outer side and end face of the bearing can be kept consistent, that is, the air pressure balance state is always maintained during use, so that the grease in the bearing installation gap 200, the grease on the inner peripheral wall of the bearing, and the grease on the outer peripheral wall of the bearing are not easy to leak due to the air pressure difference, and external pollutants and particles are not easy to enter the interior of the bearing due to the pressure difference after cooling, which effectively prevents the internal grease from contaminating and failing and the internal wear of the bearing. In addition, the air-permeable and grease-impermeable material 6 also has the characteristic of blocking grease penetration, which is not easy to cause the grease in the bearing installation gap 200, the grease on the inner peripheral wall of the bearing, and the grease on the outer peripheral wall of the bearing to have oil cross-talk, making the bearing not easy to be damaged, and greatly extending the service life of the bearing.

[0045] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the application should be included in the scope of protection of the present application.

Claims

1. A gas pressure balanced four-row tapered roller bearing, characterized in that: The invention comprises an inner ring group (1) and an outer ring group (2), wherein an installation gap (200) is arranged between the outer peripheral wall of the inner ring group (1) and the inner peripheral wall of the outer ring group (2), wherein the installation gap (200) has four rows of roller installation grooves, wherein a plurality of tapered rollers (3) are rotatably mounted in the roller installation grooves, and an annular retaining frame (4) for relatively fixing the tapered rollers (3) is arranged in each row of the roller installation grooves, and the two ends of the installation gap (200) are respectively sealed by two groups of oil seal groups (5), wherein a plurality of inner vent holes (300) are arranged radially on the inner ring group (1), and the outer ring group (2) has a plurality of inner vent holes (300) arranged radially. A plurality of outer air holes (400) are radially arranged along the upper edge, and air pressure balance holes (500) are arranged on both end faces of the outer ring group (2). The air pressure balance holes (500), the inner air holes (300), and the outer air holes (400) are all connected to the installation gap (200) and are filled with air-permeable and grease-proof materials (6) inside. The number of the outer air holes (400) is between 4 and 14, and the plurality of the outer air holes (400) are symmetrically spaced around the central axis of the bearing, and the spacing between adjacent inner air holes (300) is 0.2 to 0.4 times the radius of the inner ring group (1).

2. The air pressure balanced four-row tapered roller bearing according to claim 1, characterized in that: The inner surface of the inner ring group (1) is provided with a spiral grease groove (100), and each circle of the spiral grease groove (100) corresponds to 3 to 8 inner ventilation holes (300) arranged at even intervals.

3. The air pressure balanced four-row tapered roller bearing according to claim 2, characterized in that: The inner vent holes (300) on adjacent circles of the spiral grease grooves (100) are arranged in a staggered manner.

4. The air pressure balanced four-row tapered roller bearing according to claim 1, characterized in that: The four rows of tapered rollers (3) divide the bearing into a load zone 1, a load zone 2, a load zone 3 and a load zone 4; a portion of the external vent holes (400) are evenly spaced on a dividing line between the load zone 1 and the load zone 2; the remaining external vent holes (400) are evenly spaced on a dividing line between the load zone 3 and the load zone 4; and there are 4 to 7 external vent holes (400) on each of the two dividing lines.

5. The air pressure balanced four-row tapered roller bearing according to claim 1, characterized in that: A first high-carbon alloy steel sleeve (7) is arranged in the inner vent hole (300), a second high-carbon alloy steel sleeve (8) is arranged in the outer vent hole (400), and the air-permeable and grease-proof material (6) is filled in the first high-carbon alloy steel sleeve (7) and the second high-carbon alloy steel sleeve (8).

6. The air pressure balanced four-row tapered roller bearing according to claim 1, characterized in that: The breathable and grease-impermeable material (6) is a nano-coated sponge, a polypropylene nano-composite material or a microporous PET breathable material.

7. The air pressure balanced four-row tapered roller bearing according to claim 1, characterized in that: The inner ring group (1) comprises a first inner ring (11) and a second inner ring (12), wherein the first inner ring (11) and the second inner ring (12) respectively correspond to two rows of tapered rollers (3), and an inner sealing groove is provided at the junction of the inner side walls of the first inner ring (11) and the second inner ring (12), wherein an inner diameter sealing ring (13) is embedded and fixed in the inner sealing groove.

8. The air pressure balanced four-row tapered roller bearing according to claim 7, characterized in that: The inner diameter sealing ring (13) comprises an inner ring skeleton (131) and an inner ring rubber layer (132), wherein the inner ring rubber layer (132) is wrapped around the outer surface of the inner ring skeleton (131), and a notch (1321) is provided at one corner of the inner ring rubber layer (132) to allow one side corner of the inner ring skeleton (131) to leak out.

9. The air pressure balanced four-row tapered roller bearing according to claim 1, characterized in that: The outer ring group (2) includes a central outer ring (21), two side outer rings (22), two end retaining rings (23) and two outer spacer rings (24), one of the outer spacer rings (24) being clamped between one end of the central outer ring (21) and one of the side outer rings (22), and the other outer spacer ring (24) being clamped between the other end of the central outer ring (21) and the other of the side outer rings (22). The two end retaining rings (23) are respectively located at the two end surfaces of the bearing, the air pressure balance hole (500) is provided on the end retaining rings (23), the external vent hole (400) is provided on the outer spacer rings (24), and the oil seal group (5) is installed between the inner side of the end retaining rings (23) and the outer side of the inner ring group (1).

10. The air pressure balanced four-row tapered roller bearing according to claim 1, characterized in that: The oil seal group (5) comprises an oil seal skeleton (51), an oil seal rubber layer (52) and a clamping spring (53); the oil seal rubber layer (52) is wrapped around the outer side surface of the oil seal skeleton (51); an annular groove corresponding to the clamping spring (53) is provided on the oil seal rubber layer (52); one end surface of the oil seal rubber layer (52) is pressed against the outer peripheral wall of the inner ring group (1) through the clamping spring (53); and the other end surface of the oil seal rubber layer (52) is pressed against the inner peripheral wall of the outer ring group (2) through the oil seal skeleton (51).

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