Axle box bearing suitable for higher-speed-grade motor train unit
By using large circular arc raceways, logarithmic curved rollers and automatic lubrication systems in the bearings, the problem of reduced life of high-speed train bearings at higher speeds is solved, and bearing reliability at higher speed levels is achieved. Improved durability.
Patent Information
- Application Number
- CN202421117638.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-22
- Publication Date
- 2024-12-17
- Estimated Expiration
- 2034-05-22
AI Technical Summary
Existing bearings have reduced service life in high-speed trains, making it difficult to meet the high reliability and long life requirements at higher speed levels, especially at speeds of 400km/h or higher. The bearing design needs to be improved to accommodate more stringent condition.
A bearing including ventilation grease replenishment plug, bearing outer ring, roller, sealing cover, bearing inner ring, middle partition ring and cage was designed. The large circular arc raceway and logarithmic curved roller design are used to increase the design of Large sealed grease storage space to improve the accuracy of parts, and realize automatic grease replenishment and pressure leakage through ventilation grease replenishment holes to avoid grease leakage and unstable operation temperature.
It improves the ultimate speed and life of the bearing, extends the repair and maintenance cycle, enhances the durability and reliability of the bearing, reduces heat loss and temperature rise in the early stages of operation, and ensures stable operation at higher speed levels.
Smart Images
Figure CN222185471U_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of railway vehicle running systems, in particular to an axle box bearing suitable for higher speed grade EMUs. Background Art
[0002] my country's high-speed railway development has achieved remarkable achievements. It has built the world's largest and fastest modern high-speed railway network. High-speed, plateau, high-cold and heavy-load railway technologies have reached the world's leading level. Fuxing series Chinese standard EMUs are running on the vast land of the motherland. China's high-speed railway is leading the development of the world's high-speed railway. At present, Europe and Japan are planning to develop higher-speed high-speed trains. In order to further meet the development requirements of China's high-speed railway and consolidate the world-class independent brand with Chinese characteristics, China Railway Group has proposed to carry out systematic research on the "CR450 Innovation Project".
[0003] As a key component of the running system of high-speed trains, the service reliability of bearings is directly related to the safe operation of high-speed trains. Theoretical studies have shown that speed has a great impact on the reliability and service life of axle box bearings. As the speed of EMUs increases, the service life of bearings will decrease accordingly. If the axle box bearings of existing EMUs in service are installed on high-speed EMUs with a speed of 400 kilometers per hour, the theoretical life of the bearings will be reduced under the premise that the axle weight, line conditions, and wheel-rail forces remain unchanged. As the speed of trains continues to increase, higher requirements and greater challenges are placed on the service reliability and life of bearings.
[0004] At present, the maximum commercial operating speed of existing EMUs is 350km / h, and they have not yet undergone a commercial application test of 400km / h. Although bearing companies have accumulated a lot of technical experience and application experience in high-speed rail EMU bearings, compared with the operating conditions of CR450 EMUs, the existing axle box bearing materials, structures, and whether the optimized and improved products can adapt to the requirements of 400km / h or higher speed trains need to be demonstrated and studied. It is necessary to carry out special research on axle box bearings of high-speed EMUs with higher speed levels.
[0005] In order to adapt to the development needs of my country's 400km / h-class trains and meet the requirements of "long life and high reliability" in the maintenance and repair of my country's high-speed trains, it is urgent to carry out a new design of bearings to obtain axle box bearings that meet higher speed levels.
[0006] To avoid stress concentration caused by edge effect, the inner and outer raceways of this patent adopt large arc shapes, and the roller generatrix adopts logarithmic curve modification design. The contact stress between the roller and the two ring raceways is evenly distributed and the force is reasonable. In order to shorten the grease running and mileage, and reduce the operating heat of the bearing in the early service period, this patent increases the sealed grease storage space based on the independent Fuxing 352226X3 bearing; in order to increase the maximum speed and bearing life, meet the requirements of high-speed operation and extend the repair and maintenance cycle and service life, the precision level of bearings and parts is improved. Summary of the invention
[0007] In order to overcome the existing defects, the present invention proposes an axle box bearing suitable for higher speed grade EMUs.
[0008] An axle box bearing suitable for use in higher speed grade EMUs comprises a ventilating and grease-replenishing plug, a bearing outer ring, a roller, a sealing cover, a bearing inner ring, a middle spacer and a retaining frame, wherein the bearing inner ring passes through the middle of the bearing outer ring, and the bearing inner ring is arranged on both sides of the middle spacer; an inner raceway and an outer raceway are formed between the bearing inner ring and the bearing outer ring, the roller is arranged in the inner raceway and the outer raceway and is sealed by the sealing cover, a through ventilating and grease-replenishing hole is arranged at the central groove position of the bearing outer ring, a ventilating and grease-replenishing plug is installed in the grease-replenishing hole, and a retaining frame is arranged in the outer raceway.
[0009] A through ventilation and grease filling hole is set at the central groove position of the outer ring of the bearing, and a ventilation and grease filling plug is installed. Its function is to replenish grease without disassembly of the bearing during use. The temperature rise of the bearing during use will cause the internal pressure to increase. In order to avoid grease leakage caused by excessive internal pressure of the bearing, necessary pressure relief is performed.
[0010] Among them, the inner diameter of the inner ring of the bearing is 130mm, and the outer diameter of the outer ring is 240mm; the width of the inner component of the bearing is 180mm, and the width of the outer ring is 160mm. The clearance before the bearing is installed is between 0.55mm and 0.95mm.
[0011] Among them, among the inner raceway and the outer raceway, the outer ring raceway angle is 9° to 11°.
[0012] Among them, in the inner raceway and the outer raceway, the inner ring raceway angle is 7°~9°, and the roller angle is 2°~4°.
[0013] Preferably, the outer ring raceway angle is 10°; the inner ring raceway angle is 7°34′, and the supporting roller angle is 2°26′. The inner ring raceway needs to be arc-shaped, and the roller profile needs to be logarithmically shaped. After shaping, the convexity of the inner ring raceway is 0μm to 9μm, and the convexity of the roller is 4μm to 26μm. The above shaping treatment can make the roller stress distribution uniform, avoid edge effect and reduce roller edge stress.
[0014] When the inner ring assembly is in a free state, the radial play of the cage is 0.30mm~1.80mm, the difference in radial play of the cage is ≤0.6mm, the diameter variation of the same group of rollers does not exceed 0.008mm, and the cone angle variation of the same group of rollers does not exceed 0.005mm.
[0015] Among them, a large rib is arranged on the inner ring, and the large rib of the inner ring forms an angle of 7°~8°30′ with the vertical direction of the inner ring axis; the large rib and the large end face of the roller are in contact to transmit force, and the large end face of the roller should be spherically modified, and the radius of the modified spherical base surface is R500~R600. The contact position between the large rib of the inner ring and the large end face of the roller will affect the operating temperature of the bearing. When the contact position is close to the upper part of the large rib, the linear speed is large and the friction heat is slightly large. When the contact position is close to the lower part of the large rib and close to the oil storage groove, the operating temperature is often unstable. To avoid this problem, the contact position is as close as possible to the lower middle position of the large rib.
[0016] Preferably, the large rib angle is 7°42′, and the modified spherical base radius is R540.
[0017] Wherein, an oil storage groove is arranged on the side where the middle spacer ring contacts the retaining frame.
[0018] The inner diameter surface of the middle spacer ring is provided with a fillet of R1.5 to R3.5, preferably R2.5
[0019] The sealing cover adopts a stamped steel plate structure, the outer diameter surface of the sealing cover and the inner diameter surface of the bearing outer ring 2 are interference fit, the inner diameter surface of the sealing cover and the outer diameter surface of the large end of the bearing inner ring are clearance fit, and the clearance size is 0.2mm~0.6mm, preferably 0.4mm.
[0020] The utility model is designed to be suitable for axle box bearings for higher speed EMUs. Compared with existing bearings, its accuracy level is P4 to P2. The improvement in accuracy level increases the maximum speed of the bearing, which can meet the needs of higher speed EMUs for high-speed trains, and the durability of the bearing is correspondingly improved to a certain extent.
[0021] This application adopts a stamped steel plate sealing cover structure, with a grease storage capacity of 153g on each side, and the grease storage space at the sealing part is increased by 35%, which is conducive to further reducing the heat of grease mixing in the initial operation, and can effectively reduce the temperature rise of the bearing during service. By setting a ventilation grease filling hole at the central groove position of the outer ring and installing a ventilation grease filling plug, the bearing can be replenished with grease without disassembly during use. In addition, it can effectively remove the internal pressure caused by the temperature rise of the bearing and avoid grease leakage and grease spraying at the seal caused by excessive internal pressure.
[0022] The utility model adjusts the contact position between the inner ring large rib and the roller large end face. The angle of the large rib of the bearing is preferably 7°42′, the arc of the large end face of the roller is R540, the contact point position is slightly moved down, and the relative linear speed of the inner ring large rib and the large end face of the roller is reduced, which can reduce the operating temperature to a certain extent. In addition, the grease injection amount of the bearing is 220g±15g, and the grease type is CR G25B, which is conducive to reducing the operating temperature during operation. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 This is a schematic diagram of the axle box bearing suitable for EMUs with higher speed ratings.
[0024] Figure 2 This is a schematic diagram of the structure of the ventilation and fat-replenishing plug.
[0025] Figure 3 Schematic diagram of the bearing outer ring structure.
[0026] Figure 4 Schematic diagram of the roller structure.
[0027] Figure 5 Schematic diagram of the bearing inner ring structure.
[0028] Figure 6 Schematic diagram of the cage structure.
[0029] Figure 7 Schematic diagram of the large rib structure of the bearing inner ring.
[0030] Figure 8 It is a schematic diagram of the clearance fit between the inner diameter surface of the sealing cover and the outer circle of the large end of the inner ring. DETAILED DESCRIPTION
[0031] The following describes in detail an axle box bearing for a higher speed grade EMU provided by the present invention in conjunction with the accompanying drawings and specific embodiments.
[0032] Figure 1-6 As shown, an axle box bearing suitable for a higher speed grade EMU includes a ventilating and grease-filling plug 1, a bearing outer ring 2, a roller 3, a sealing cover 4, a bearing inner ring 5, a middle spacer 6 and a retaining frame 7. The bearing inner ring 5 passes through the middle of the bearing outer ring 2, and the bearing inner ring 5 is arranged on both sides of the middle spacer 6; an inner raceway 30 and an outer raceway 31 are formed between the bearing inner ring 5 and the bearing outer ring 2, the roller 3 is arranged in the inner raceway 30 and the outer raceway 31, and is sealed by the sealing cover 4, a through ventilating and grease-filling hole 10 is arranged at the central groove position of the bearing outer ring 2, the ventilating and grease-filling plug 1 is installed in the grease-filling hole 10, and a retaining frame 7 is arranged in the outer raceway 31.
[0033] A through ventilation and grease filling hole is set at the central groove position of the outer ring of the bearing, and a ventilation and grease filling plug is installed. Its function is to replenish grease without disassembly of the bearing during use. The temperature rise of the bearing during use will cause the internal pressure to increase. In order to avoid grease leakage caused by excessive internal pressure of the bearing, necessary pressure relief is performed.
[0034] The inner diameter 50 of the bearing inner ring 5 is 130 mm, and the outer diameter 20 of the outer ring 2 is 240 mm; the width of the bearing inner component is 180 mm, and the width 21 of the outer ring 2 is 160 mm. The clearance before the bearing is installed is between 0.55 mm and 0.95 mm.
[0035] In the inner raceway 30 and the outer raceway 31, the outer ring raceway angle is 9° to 11°.
[0036] In the inner raceway 30 and the outer raceway 31 , the inner ring raceway angle is 7° to 9°, and the roller angle is 2° to 4°.
[0037] The outer ring raceway angle is 10°; the inner ring raceway angle is 7°34′, and the supporting roller angle is 2°26′. The inner ring raceway needs to be arc-shaped, and the roller profile needs to be logarithmically shaped. After shaping, the convexity of the inner ring raceway is 0μm to 9μm, and the convexity of the roller is 4μm to 26μm. The above shaping treatment can make the roller stress distribution uniform, avoid edge effect and reduce roller edge stress.
[0038] When the inner ring assembly is in a free state, the radial play of the cage is 0.30mm~1.80mm, the difference in radial play of the cage is ≤0.6mm, the diameter variation of the same group of rollers does not exceed 0.008mm, and the cone angle variation of the same group of rollers does not exceed 0.005mm.
[0039] Figure 7 As shown, a large rib is provided on the inner ring, and the large rib of the inner ring forms an angle of 7° to 8°30′ with the vertical direction of the inner ring axis; the large rib and the large end face of the roller are in contact to transmit force, and the large end face of the roller should be spherically modified, and the radius of the modified spherical base surface is R500 to R600. The contact position between the large rib of the inner ring and the large end face of the roller will affect the operating temperature of the bearing. When the contact position is close to the upper part of the large rib, the linear speed is large and the friction heat is slightly large. When the contact position is close to the lower part of the large rib and close to the oil storage groove, the operating temperature is often unstable. To avoid this problem, the contact position is as close to the middle and lower position of the large rib as possible. An oil storage groove 71 is provided on the side where the intermediate spacer ring 6 and the retaining frame 7 contact.
[0040] The inner diameter surface of the middle spacer ring 6 is provided with a fillet of R1.5 to R3.5, preferably R2.5.
[0041] Figure 8As shown, the sealing cover 4 adopts a stamped steel plate structure, the outer diameter surface of the sealing cover 4 and the inner diameter surface of the bearing outer ring 2 are interference fit, and the inner diameter surface of the sealing cover 4 and the outer diameter surface of the large end of the bearing inner ring 5 are clearance fit, and the clearance size is 0.2mm~0.6mm, preferably 0.4mm.
[0042] Finally, it should be noted that the above embodiments are only used to describe the technical solution of the present invention rather than to limit the technical method. The present invention can be extended to other modifications, changes, applications and embodiments in application, and therefore all such modifications, changes, applications and embodiments are considered to be within the scope of the present invention.
Claims
1. An axle box bearing suitable for use in a higher speed grade EMU, comprising a ventilating grease replenishing plug (1), a bearing outer ring (2), a roller (3), a sealing cover (4), a bearing inner ring (5), a middle spacer ring (6) and a retaining frame (7), characterized in that: The bearing inner ring (5) passes through the middle of the bearing outer ring (2), and the bearing inner ring (5) is arranged on both sides of the middle spacer (6); an inner raceway (30) and an outer raceway (31) are formed between the bearing inner ring (5) and the bearing outer ring (2), and the roller (3) is arranged in the inner raceway (30) and the outer raceway (31), and is sealed by a sealing cover (4); a through ventilation and grease filling hole (10) is arranged at the central groove position of the bearing outer ring (2), and a ventilation and grease filling plug (1) is installed in the grease filling hole (10); and a retaining frame (7) is arranged in the outer raceway (31).
2. The axle box bearing for a higher speed EMU according to claim 1 is characterized in that: The inner diameter (50) of the bearing inner ring (5) is 130 mm, and the outer diameter (20) of the outer ring (2) is 240 mm; the width of the bearing inner component is 180 mm, and the width (21) of the outer ring (2) is 160 mm.
3. The axle box bearing for a higher speed EMU according to claim 1 is characterized in that: In the inner raceway (30) and the outer raceway (31), the outer ring raceway angle is 9° to 11°.
4. The axle box bearing for a higher speed EMU according to claim 1 is characterized in that: In the inner raceway (30) and the outer raceway (31), the inner raceway angle is 7° to 9°.
5. The axle box bearing for a higher speed EMU according to claim 3 or 4, characterized in that: The outer ring raceway angle is 10°; the inner ring raceway angle is 7°34′, and the supporting roller angle is 2°26′.
6. The axle box bearing for a higher speed EMU according to claim 1 is characterized in that: The inner ring (5) is provided with a large rib (51), and the large rib of the inner ring forms an angle of 7° to 8°30′ with respect to the vertical plane direction of the inner ring axis; the large rib (51) and the large end face of the roller are in contact to transmit force, and the large end face of the roller should be spherically modified, and the radius of the modified spherical base surface is R500 to R600.
7. The axle box bearing for a higher speed EMU according to claim 6 is characterized in that: The angle of the large rib (51) is 7°42′, and the radius of the modified spherical base surface is R540.
8. The axle box bearing for a higher speed EMU according to claim 1 is characterized in that: An oil storage groove (71) is provided on the side surface where the middle spacer (6) and the retaining frame (7) contact each other.
9. The axle box bearing for a higher speed EMU according to claim 1, characterized in that: The inner diameter surface of the middle spacer ring (6) is provided with a rounded angle of R1.5 to R3.5, preferably R2.
5.
10. The axle box bearing for a higher speed EMU according to claim 1, characterized in that: The sealing cover (4) adopts a stamped steel plate structure, the outer diameter surface of the sealing cover (4) and the inner diameter surface of the bearing outer ring (2) are interference fit, and the inner diameter surface of the sealing cover (4) and the large end outer diameter surface of the bearing inner ring (5) are clearance fit, and the clearance size is 0.2mm to 0.6mm, preferably 0.4mm.