Low-energy-consumption long-service-life bearing

Abstract

The invention discloses a bearing with low energy consumption and long service life. The bearing comprises an inner ring, an outer flange, a retainer, an outer ring, a small flange and a tapered roller, the inner ring is of a structure with a cone-shaped middle and two cylindrical ends, one end is a small-head end, a small flange is sleeved on the small-head end, the other end is a large-head end, and an inner raceway is arranged between the large-head end and the small-head end. And an inner hole of the outer ring comprises an outer raceway section and a cylindrical section. When the inner ring and the outer ring are assembled together, the inner ring is located in the inner hole of the outer ring, so that the inner raceway section, the outer raceway section and the step part of the outer flange form a friction working part. And a retainer is arranged in the working part. The tapered roller is located in the retainer window, and the retainer drives the roller to rotate along the inner raceway, the outer raceway and the step part during working. The bearing has the advantages of being small in number of parts, good in assembly performance, compact in structure, large in load, low in noise, low in driving torque, ultralow in temperature rise, ultralow in friction torque, ultralow in cost, ultra-long in service life, integrated, free of pre-tightening (adjustment) zero clearance all the time and the like, and has the advantages of improving the efficiency of a transmission system, saving energy, reducing emission and the like.

Description

Technical Field

[0001] The invention relates to the field of rolling bearings, in particular to a low-energy-consumption and long-life bearing. Background Art

[0002] With the rapid development of modern industry, bearings, as core components in mechanical transmission mechanisms, are increasingly given more stringent functions, such as greater loads, faster speeds, longer life and higher rigidity; in addition, higher requirements are placed on bearings in terms of transmission efficiency, noise, vibration, temperature rise, price, energy conservation and environmental protection. Taking into account the requirements of the above factors on bearings, the main purpose is to reduce the cost of use, improve energy utilization, extend the service life of bearings, and contribute to cost savings, energy conservation and emission reduction. Existing bearings, especially motor vehicle hub bearings, have the following problems that need to be solved:

[0003] 1. Peeling problem of the working surface of the bearing: Due to the unreasonable design of the bearing and the fact that high-speed and heavy-load bearings generally use roller bearings, the temperature of the bearing will definitely rise under the dual effects of high speed and heavy load, and the temperature rise of each component of the bearing is different. In order to prevent the bearing temperature from rising to a certain level and causing "stuck" or even "stuck" accidents, it is necessary to leave clearance for the bearing, and it is necessary to ensure that the bearing can operate freely under extreme temperature rise conditions; although leaving enough clearance for the bearing solves the "stuck" problem of the bearing, it also brings an equally serious problem, namely the peeling problem of the working surface of the bearing. Due to the existence of bearing clearance, the various parts inside the bearing cannot bear the load evenly and uniformly. For example, the raceway of the stationary inner ring or outer ring is divided into a load area and a non-load area. The entire raceway working surface only bears the load by the local load area. The peeling of the working surface occurs in this area. This is caused by the stress concentration problem. Due to the existence of clearance, the inner and outer raceways and rollers actually bear super loads instead of uniform and uniform loads, which greatly shortens the life of the bearing.

[0004] 2. Temperature rise and ablation problems of bearing parts: The temperature rise of bearings is divided into normal temperature rise and abnormal temperature rise. Normal temperature rise refers to the temperature rise that matches the working conditions of the bearings. For example, deep groove ball bearings or cylindrical roller bearings used in motors only bear pure radial loads, and their temperature rise is normal temperature rise; abnormal temperature rise refers to the temperature rise caused by the mismatch between the bearings and the working conditions. For example, if there is clearance in the bearings, there will be slight collisions between the rolling elements and the retainers and between the inner and outer raceways, which will cause temperature rise. In addition, in order to bear a certain axial force, the existing motor vehicle wheel hub bearings are designed with an angular contact structure inside. Under normal Under working conditions, the wheel hub bearings of motor vehicles only bear pure radial loads and axial loads only when turning. However, due to the angular contact structure inside, even if the motor vehicle travels in a straight line for more than 99.99% of the time, additional harmful derived axial loads are still generated inside. The friction torque generated by this derived axial load is 100% converted into heat, resulting in abnormal temperature rise of the bearing. If the abnormal temperature rise of the bearing reaches a certain level, it will cause evaporation and oxidation of the grease. Over time, the grease will age, solidify, and fail, causing increased friction and wear inside the bearing, and ultimately causing the bearing to burn out and become scrapped.

[0005] 3. High energy consumption problem: From the analysis in the second paragraph above, it can be seen that almost all motor vehicle wheel hub bearings are angular contact bearings. When running in a straight line, additional harmful derived axial loads will be generated. These derived axial loads will inevitably produce friction torque. If the motor vehicle is to run normally, this derived friction torque must be overcome, which consumes energy. The additional increase in energy consumption also increases the operating cost of the motor vehicle.

[0006] 4. Bearing clearance problem: The bearing clearance has a significant impact on bearing life, temperature rise, noise, vibration, etc. The existing structure makes it impossible to adjust the bearing clearance to zero clearance in design or process, resulting in performance degradation, shortened life, and regular overhaul and maintenance. Summary of the invention

[0007] The purpose of the present invention is to provide a low-energy consumption and long-life bearing, which comprises an inner ring, an outer rib, a retainer, an outer ring, a small rib and a plurality of tapered rollers.

[0008] The inner ring as a whole is a structure with a cone shape in the middle, a cylindrical shape at both ends and a cylindrical hole inside. The end with a smaller radius of the cylindrical segment at both ends is marked as the small head end, and the end with a larger radius is marked as the large head end. The area between the large head end and the small head end is marked as the inner raceway.

[0009] The small rib is a hollow cylindrical structure, which is sleeved on the outer cylindrical surface of the small head end of the inner ring. A working surface is arranged on the end surface of the small rib facing the large head end of the inner ring.

[0010] The outer ring is a hollow rotating body structure. The inner hole of the outer ring includes an outer raceway section and a cylindrical section. The inner hole at the outer raceway section is in a cone shape. The end of the outer raceway section with a small radius is recorded as the small diameter end, and the end with a large radius is recorded as the large diameter end. The small diameter end is connected to the cylindrical section.

[0011] The outer rib is an annular structure as a whole, including an outer rib body and a step portion. One end of the outer rib body is connected to the large diameter end of the outer raceway section, and the inner side wall at the connection position is provided with an annular step portion.

[0012] When the inner ring and the outer ring are assembled together, the inner ring is located in the inner hole of the outer ring, so that the inner raceway, the outer raceway and the step portion form a friction working area.

[0013] A retainer is installed in the friction working area.

[0014] A plurality of the tapered rollers are located in the friction working area and are evenly separated by the retainer window. When working, the tapered rollers rotate along the step portions of the inner raceway, the outer raceway and the outer rib inside the friction working area.

[0015] Furthermore, the outer diameter of the inner raceway section gradually increases from the small end to the large end.

[0016] Furthermore, the semi-cone angle of the outer raceway is a=1° to 9°.

[0017] Furthermore, the tapered roller is a cone-shaped structure, and the tapered surface of the tapered roller is in contact with the inner raceway and the outer raceway with zero clearance.

[0018] Furthermore, the tapered roller is a cone-shaped structure, and the end with a larger radius is recorded as a spherical base surface, and the spherical base surface is in contact with the step portion of the outer rib.

[0019] Furthermore, the inner ring and the small rib are an integrally formed structure.

[0020] Furthermore, the small rib and the inner ring are two parts.

[0021] A plurality of screw holes are provided on the outer cylindrical surface of the small rib. When the small rib is mounted on the small head end of the inner ring, a cylindrical pin with an interference fit or an overfit with the screw hole is placed in the screw hole, and the cylindrical pin is pushed to move in the screw hole by a set screw. The small rib is axially positioned and locked on the inner ring by the thread on one end of the cylindrical pin away from the set screw.

[0022] Furthermore, the outer ring and the outer rib are two parts or an integrally formed structure.

[0023] Furthermore, the bearing also includes an outer oil seal and an inner oil seal.

[0024] The outer oil seal is arranged between the inner ring big head end and the outer rib, and has an interference fit with the inner hole of the outer rib body, and has an interference sealing fit with the outer cylindrical surface of the inner ring big head end.

[0025] The inner oil seal is arranged between the small rib and the outer ring cylindrical section, has an interference fit with the inner hole of the outer ring cylindrical section, and has an interference sealing fit with the outer cylindrical surface of the small rib.

[0026] The technical effect of the present invention is unquestionable, and the beneficial effects of the present invention are as follows:

[0027] The present invention has the advantages of small number of parts, good assembly performance, compact structure, large load, low cost, low temperature rise, low noise, low friction torque, super energy saving, zero clearance during normal operation, ultra-long life, high strength, high torque rigidity, high reliability, high stability, etc. It is widely used to replace motor vehicle wheel hub bearings and many mechanisms that need to control bearing clearance. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of a low energy consumption and long life bearing structure;

[0029] Figure 2 It is a schematic diagram of the outer ring structure;

[0030] Figure 3 It is a schematic diagram of the inner circle structure;

[0031] Figure 4 It is a schematic diagram of the small rib structure;

[0032] Figure 5 is a schematic diagram of the retainer structure;

[0033] Figure 6 is a schematic diagram of the roller structure;

[0034] Figure 7 It is a schematic diagram of the connection between the inner ring and the small rib;

[0035] Figure 8 This is the working principle diagram of the bearing without adjustment (control) and zero clearance;

[0036] Fig. 9 This is the axial force transmission route diagram when the bearing is subjected to axial force in the left direction;

[0037] Fig.10 This is the axial force transmission route diagram when the bearing is subjected to axial force in the right direction;

[0038] Fig.11 It is the most typical internal structure and force analysis diagram of the first, second and third generation wheel hub units of existing passenger cars;

[0039] Fig.12This is a schematic diagram of the internal heating parts of existing double-row tapered roller bearing products;

[0040] Fig.13 This is a schematic diagram of existing rail transit wheelset (axle box) bearing products;

[0041] Fig.14 This is a graph showing the change in axial clearance of the bearing described in this application under conditions of thermal expansion and contraction;

[0042] Fig.15 The force analysis diagram for each single row of the existing double-row tapered roller bearing;

[0043] Fig.16 This is a force analysis diagram of a low energy consumption and long life bearing;

[0044] Fig.17 This is a schematic diagram of the internal heating parts of a low-energy consumption and long-life bearing;

[0045] Fig.18 It is a schematic diagram of bearing axial clearance and relative bearing life;

[0046] Fig.19 This is a schematic diagram of the application of the bearing described in this application on the wheel end of the steering axle of a commercial vehicle;

[0047] Fig. 20 A schematic diagram of the application of a low-energy consumption and long-life bearing with a different internal structure on the wheel end of a commercial vehicle steering axle;

[0048] Fig.21 This is a schematic diagram of the application of the bearing described in this application on the wheel end of the commercial vehicle drive axle;

[0049] Fig. 22 A schematic diagram of the application of a low-energy consumption and long-life bearing with a different internal structure on the wheel end of a commercial vehicle drive axle;

[0050] Fig.23 A schematic diagram of the application of a low-energy consumption and long-life bearing with a different internal structure on the wheel end of a passenger car, namely, a third-generation wheel hub unit assembly;

[0051] Fig.24 A schematic diagram of the application of a low-energy consumption and long-life bearing with a different internal structure on the wheel end of a passenger car, i.e., the fourth-generation wheel hub unit assembly;

[0052] Fig.25 This is a schematic diagram of the existing rail transit gearbox structure;

[0053] Fig.26 This is a schematic diagram of the application of a low-energy consumption and long-life bearing with a different internal structure in a rail transit gearbox.

[0054] In the figure: inner ring 1, inner raceway 101, small head end 102, large head end 103, outer oil seal 2, outer rib 3, outer rib body 301, step portion 302, retainer 4, outer ring 5, small rib 6, working surface 601, tapered roller 7, tapered roller heating part 703, inner oil seal 8, cylindrical pin 9, set screw 10. Passenger car wheel hub bearing outer ring 1101, passenger car wheel hub bearing inner ring 1102, steel ball 1103, double row tapered roller bearing outer ring 1201, double row tapered roller bearing inner ring 1202, double row tapered roller bearing roller 1203, double row tapered roller bearing roller heating part 1204, existing rail transit wheelset (axle box) bearing outer ring 1301, existing rail transit wheelset (axle box) bearing inner ring 1302, existing rail transit wheelset (axle box) bearing roller 1303, commercial vehicle steering axle wheel end assembly hub 1401, steering knuckle 1402, external oil seal 1403, inner oil seal 1404, ABS gear ring 1405, brake disc 1406, rim adapter plate 1407, bearing outer ring and wheel hub integrated into one part 1408, commercial vehicle drive axle wheel end assembly hub 1501, half shaft 1502, shaft tube 1503, brake drum 1504, rim 1505, bearing outer ring and commercial vehicle drive axle hub integrated into one part 1506, universal joint cover 17, cylindrical roller bearing 18, tapered roller bearing 19, four-point contact ball bearing 20, input shaft 21, output shaft 22, low energy consumption and long life bearing 23. DETAILED DESCRIPTION

[0055] The present invention is further described below in conjunction with the embodiments, but it should not be understood that the above subject matter of the present invention is limited to the following embodiments. Without departing from the above technical ideas of the present invention, various substitutions and changes are made according to the common technical knowledge and customary means in the art, which should all be included in the protection scope of the present invention.

[0056] Embodiment 1:

[0057] A low-energy-consumption and long-life bearing comprises an inner ring 1, an outer rib 3, a retainer 4, an outer ring 5, a small rib 6 and a plurality of tapered rollers 7.

[0058] The inner ring 1 as a whole is a rotating body structure with a conical middle, cylindrical ends and a hollow interior. The end with a smaller radius of the cylindrical segment at both ends is marked as a small head end 102, and the end with a larger radius is marked as a large head end 103. The area between the large head end 103 and the small head end 102 is marked as an inner raceway 101 section.

[0059] The small rib 6 is a hollow cylindrical structure, which is mounted on the outer cylindrical surface of the inner ring small head end 102 . A working surface 601 is provided on the end surface of the small rib 6 facing the large head end 103 .

[0060] The outer ring 5 is a hollow rotating body structure. The inner hole of the outer ring 5 includes an outer raceway 501 section and a cylindrical section 502. The inner hole at the outer raceway 501 section is in a cone shape. The end of the outer raceway 501 section with a small radius is recorded as a small diameter end, and the end with a large radius is recorded as a large diameter end. The small diameter end is connected to the cylindrical section 502.

[0061] The outer rib 3 is an annular structure, comprising an outer rib body 301 and a step portion 302. One end of the outer rib body 301 is connected to the large diameter end of the outer raceway 501, and an annular step portion 302 is provided inside the connection position.

[0062] When the inner ring 1 and the outer ring 5 are assembled together, the inner ring 1 is located in the inner hole of the outer ring 5, so that the inner raceway 101, the outer raceway 501 and the step portion 302 form a friction working area;

[0063] A retainer 4 is installed in the friction working area.

[0064] The plurality of tapered rollers 7 are located in the window of the retainer 4 in the friction working area, and the plurality of tapered rollers 7 are evenly spaced apart by the retainer 4. During operation, the retainer 4 drives the tapered rollers 7 to rotate in the friction working area against the inner raceway 101, the outer raceway 501 and the step portion 302 of the outer rib.

[0065] Embodiment 2:

[0066] The main structure of this embodiment is the same as that of Embodiment 1. Furthermore, the outer diameter of the inner raceway 101 section gradually increases from the small end 102 to the large end 103.

[0067] Embodiment 3:

[0068] The main structure of this embodiment is the same as any one of Embodiments 1 to 2. Furthermore, the semi-cone angle of the outer raceway 501 is a=1° to 9°.

[0069] Embodiment 4:

[0070] The main structure of this embodiment is the same as any one of Embodiments 1 to 3. Furthermore, the semi-cone angle of the outer raceway 501 is a=1°.

[0071] Embodiment 5:

[0072] The main structure of this embodiment is the same as any one of Embodiments 1 to 3. Furthermore, the semi-cone angle of the outer raceway 501 is a=9°.

[0073] Embodiment 6:

[0074] The main structure of this embodiment is the same as any one of Embodiments 1 to 5. Furthermore, the tapered roller 7 is a conical structure, and the conical surface of the tapered roller 7 is in contact with the inner raceway 101 and the outer raceway 501 with zero clearance.

[0075] Embodiment 7:

[0076] The main structure of this embodiment is the same as any one of Embodiments 1 to 6. Furthermore, the tapered roller 7 is a conical structure, and the end with a larger radius is marked as a spherical base surface 701 , and the spherical base surface 701 is in contact with the step portion 302 .

[0077] Embodiment 8:

[0078] The main structure of this embodiment is the same as any one of Embodiments 1 to 7. Furthermore, the inner ring 1 and the small rib 6 are an integrally formed structure.

[0079] Embodiment 9:

[0080] The main structure of this embodiment is the same as any one of Embodiments 1 to 7. Furthermore, the small rib 6 and the inner ring 1 are two parts.

[0081] A plurality of screw holes are provided on the outer cylindrical surface of the small rib 6. When the small rib 6 is mounted on the outer cylindrical surface of the small head end 102 of the inner ring, a cylindrical pin with an interference fit or an overfit with the screw hole is placed in the screw hole, and the cylindrical pin is pushed to move in the screw hole by the set screw. The small rib 6 is axially positioned and locked on the inner ring 1 by the thread on the end of the cylindrical pin away from the set screw.

[0082] Embodiment 10:

[0083] The main structure of this embodiment is the same as any one of embodiments 1 to 7 and 9. Further, the small rib 6 is mechanically fixed to the outer cylindrical surface of the small head of the inner ring 1. In this embodiment, the parts diagram of the small rib 6 is shown in FIG. Figure 4 The inner hole is positioned and fixed on the outer cylindrical surface of the small head of the inner ring 1 by means of threads or interference fit.

[0084] One of the most common positioning and fixing methods is to fix the small end face of the inner ring 1 to the small rib 6 (see Figure 7 ).

[0085] Another is that the small rib 6 of the low energy consumption and long life bearing is fixed on the outer cylindrical surface of the small head end 102 of the inner ring 1 through an internal thread (see Fig.17), several screw holes are drilled in the radial direction of the small rib 6, and there is a cylindrical pin inside the screw hole. There is a small interference or transition fit between the cylindrical pin and the screw hole. Before turning the internal thread of the small rib 6, use a set screw to push the cylindrical pin to move in the screw hole, ensure that the cylindrical pin slightly protrudes from the inner hole, and then use a thread cutter to turn the internal thread hole of the small rib 6. When the bearing needs to remove the roller 7 and the retainer 4, first loosen the set screw, the cylindrical pin and the external thread 102 of the small head of the inner ring 1 are no longer locked, unscrew the small rib 6, and the roller 7 and the retainer 4 slide out of the inner raceway 101 of the inner ring together. The roller 7, the retainer 4 and the inner ring 1 are cleaned separately. After checking that they are correct, assemble the roller 7 and the retainer 4 to the inner raceway 101 of the inner ring 1, screw the small rib 6 on the external thread 102 of the small head of the inner ring 1, tighten the set screw, and the small rib 6 is firmly fixed on the external thread 102 of the small head of the inner ring 1.

[0086] The third type is that the small rib 6 of the low energy consumption and long life bearing is fixed on the outer cylindrical surface of the small head end 102 of the inner ring 1 through an internal thread (see Figure 1 ), in order to prevent the small rib 6 from loosening, thread locking glue can be applied between the threads, or the small rib 6 can be fixed to the outer cylindrical surface of the small head end 102 of the inner ring 1 by other means.

[0087] In fact, due to the advantages of ultra-long maintenance-free, ultra-long life, high rigidity, high reliability and high stability, this low-energy consumption and long-life bearing greatly extends the maintenance cycle of the bearing.

[0088] Embodiment 11:

[0089] The main structure of this embodiment is the same as any one of Embodiments 1 to 10, and the outer ring 5 and the outer rib 3 are two parts.

[0090] Embodiment 12:

[0091] The main structure of this embodiment is the same as any one of Embodiments 1 to 10, and the outer ring 5 and the outer rib 3 are an integrally formed structure.

[0092] Embodiment 13:

[0093] The main structure of this embodiment is the same as any one of Embodiments 1 to 12, and the bearing further includes an outer oil seal 2 and an inner oil seal 8.

[0094] The outer oil seal 2 is arranged between the inner ring big head end 103 and the outer rib 3 , and has an interference fit with the inner hole of the outer rib body 301 , and has an interference sealing fit with the outer cylindrical surface of the inner ring big head end 103 .

[0095] The inner oil seal 8 is arranged between the small rib 6 and the outer cylindrical section 502 , and has an interference fit with the inner hole of the outer cylindrical section 502 , and has an interference sealing fit with the outer cylindrical surface of the small rib 6 .

[0096] Embodiment 14:

[0097] The main structure of this embodiment is the same as any one of Embodiments 1 to 13. Furthermore, the inner hole at the cylindrical section 502 is in a cylindrical shape.

[0098] Embodiment 15:

[0099] The main structure of this embodiment is the same as any one of embodiments 1 to 14. Furthermore, a low-energy consumption and long-life bearing includes an inner ring 1, an outer oil seal 2, an outer rib 3, a retainer 4, an outer ring 5, a small rib 6, a tapered roller 7 and an inner oil seal 8.

[0100] The outer conical surface of the middle section of the inner ring 1 is the inner raceway 101. The part of the inner ring 1 at the left end of the inner raceway 101 is marked as the small end, and the part at the right end is marked as the large end. The outer circle of the small end is the cylindrical surface 102. The inner raceway 101 is in the shape of a conical surface.

[0101] The small rib 6 is a circular ring structure and is sleeved on the cylindrical surface 102. A working surface 601 is arranged on the end surface of the small rib 6 facing the inner raceway 101.

[0102] The inner hole of the outer ring 5 is marked as an outer raceway 501 and a cylindrical section 502 from the outer or small end to the inner end. The outer raceway 501 is in a conical shape. The small diameter end of the outer raceway 501 is connected to the cylindrical section 502.

[0103] The outer rib 3 comprises an outer rib body 301 and a step portion 302. The outer rib 3 is arranged at the outer end side of the outer ring 5. The step portion 302 is located between the small end of the outer ring 5 and the outer rib body 301.

[0104] The outer ring 5 is coaxially sleeved on the outer side of the inner ring 1. The outer raceway 501, the inner raceway 101, the small rib 6 and the step portion 302 enclose a friction working portion. The retainer 4 is arranged in the friction working portion. The window of the retainer 4 contains a tapered roller 7, and the tapered roller 7 is arranged in the friction working portion. The retainer 4 drives the tapered roller 7 to rotate along the inner and outer raceways. The tapered surface of the tapered roller 7 contacts the inner raceway 101 and the outer raceway 501, and the ball base surface 701 contacts the step portion 302.

[0105] The outer oil seal 2 is arranged in the gap between the outer cylindrical surface of the large end 103 of the inner ring 1 and the outer rib 3. The outer oil seal 2 is arranged on the outer end side. The outer circle of the outer oil seal 2 and the inner hole of the outer rib body 301 are interference fit, and the lip of the outer oil seal 2 and the outer cylindrical surface 103 of the large end of the inner ring 1 are interference sealed.

[0106] The inner oil seal 8 is arranged in the gap between the small rib 6 and the inner hole cylindrical section 502 of the outer ring 5. The inner oil seal 8 is arranged on the inner end side. The outer circle of the inner oil seal 8 and the inner hole of the cylindrical section 502 are interference fit, and the lip and the outer circle of the small rib 6 are interference seal fit.

[0107] Embodiment 16:

[0108] The main structure of this embodiment is the same as any one of Embodiments 1 to 15. Furthermore, it is well known that, in theory, when the bearing clearance is 0, the rolling bearing is in the best working state. However, in actual work, for heavy-loaded and axially loaded transmission mechanisms, tapered roller bearings are generally used for support. At present, due to the fact that designers do not understand the actual operating conditions of the bearings, the designed bearings have the problem of large temperature rise, and the temperature rises of the various parts that make up the bearings are different. In most cases, the temperature rise of the inner ring and the roller is higher than that of the outer ring. This is because there is sliding friction between the ball base surface of the roller and the large rib of the inner ring. The larger the sliding friction coefficient, the more frictional heat is generated, and the larger the temperature rise. In order to prevent the bearing temperature from rising to a certain level and causing "stuck" or even "stuck" accidents, clearance must be left for the bearing. The existence of clearance seriously affects the load state of the bearing, causing the rollers and the raceways of the inner and outer rings to always be in an uneven and uneven load-bearing state, resulting in a series of problems such as working surface peeling, noise, vibration, temperature increase, and shortened life. This seems to be a vicious circle, but the root cause is that the designers did not really design according to the actual operating conditions of the bearing during the design phase.

[0109] The low-energy consumption and long-life bearing of the present invention is mainly to solve the problem that a certain amount of bearing clearance needs to be adjusted and maintained on existing equipment, and the bearing clearance needs to be controlled during the production stage of the bearing. The current situation is that the hub bearings of all motor vehicles such as cars, tractors, ordinary trains, subways and high-speed trains need to control the clearance, and the bearings of high-speed trains and subway gearboxes also need to control the clearance; so the problem to be solved by the present invention has a wide range of commonalities, that is, without the need to adjust, control and maintain a certain amount of clearance during the production and assembly stages, the working clearance of the bearing is always 0, that is, the bearing is always in the best working state.

[0110] The working principle of this low energy consumption and long life bearing with zero clearance:

[0111] The low energy consumption and long life bearing of the present invention has an internal structure that does not require adjustment or pre-tightening, and its clearance is always at 0 (see Figure 8), for the convenience of explaining the problem, only three parts that affect the bearing clearance are retained, and the other parts that are not related to the clearance are deleted. Since the weight and wind resistance of all motor vehicles are applied to the outer circle of the outer ring (or inner ring) in the form of radial load, the outer circle transfers the radial load to the outer raceway, and the outer raceway transfers the load to the roller. This radial force generates a derived axial force on the outer raceway. The radial force and the derived axial force force the roller to move to the big end (or the right side) of the bell-shaped mouth formed by the outer raceway and the inner raceway. When the ball base surface 701 of the roller moves to the end face of the step portion 302 of the outer rib, the clearance between the ball base surface of the roller in the axial direction and the end face of the step portion of the outer rib is 0; the radial load makes the radial clearance between the conical surface of the roller and the inner raceway and the outer raceway is also 0. Regardless of whether the motor vehicle is stopped or in motion, as long as there is weight on the outer ring of the bearing, the bearing is always in the best working state of 0 clearance. The zero clearance working state of the bearing allows the rolling elements and inner and outer raceways of the bearing to always bear the load evenly and uniformly, completely eliminating the working condition where the rolling elements and inner and outer raceways bear super loads locally due to clearance factors, and completely eliminating the problem of premature peeling of the rolling elements and inner and outer raceways in principle. In addition, since the bearing is always in a zero clearance working state, the temperature rise, noise and vibration of the bearing itself are always at the lowest level.

[0112] Embodiment 17:

[0113] The main structure of this embodiment is the same as any one of the embodiments 1 to 16. Furthermore, the low energy consumption and long life bearing of the present invention is a set of special single-row tapered roller bearings that can simultaneously bear radial loads and axial loads in two directions. In contrast, the existing single-row tapered roller bearings can only bear radial loads and axial loads in one direction, while the existing double-row angular contact bearings can bear radial loads and axial loads in two directions.

[0114] Although the low energy consumption and long life bearing of the present invention is a single row tapered roller bearing, it can bear radial load and axial load in two directions at the same time (see Fig. 9 , 10 ), when the inner ring is subjected to an axial force in the left direction, the axial force is transmitted through the AA path, i.e. inner ring-inner raceway-roller-outer raceway-outer ring; when the inner ring is subjected to an axial force in the right direction, the axial force is transmitted through the BB path, i.e. inner ring-small rib-small end face of the roller-spherical base surface of the roller-step end face of the outer rib-outer rib (outer ring).

[0115] Embodiment 18:

[0116] The main structure of this embodiment is the same as any one of Embodiments 1 to 17. Furthermore, the low-energy consumption and long-life bearing of the present invention can significantly reduce temperature rise and energy consumption.

[0117] There are a huge number of motor vehicles in the world. Existing motor vehicle wheel hub bearings have problems of high temperature rise and high energy consumption. The temperature rise reduces the viscosity of the grease, accelerates evaporation and oxidation, and the long-term temperature rise causes the grease to solidify, age and fail, resulting in increased friction and wear of the bearing, which in turn affects the life of the bearing. The high energy consumption also pushes up the operating cost of the motor vehicle. The following compares the wheel hub bearings of passenger cars, commercial vehicles and wheelset (or axle box) bearings of rail transit vehicles, which have a huge market scale, with the bearings of the present invention, and calculates the temperature rise and energy consumption of these bearings in detail.

[0118] Existing passenger car wheel hub bearings widely use the first, second and third generation hub units, most of which are based on double row angular contact ball bearings as the basic structure, and the most common contact angle is 36° (see Fig.11 );

[0119] Existing commercial vehicle wheel hub bearings widely use two single-row tapered roller bearings, or double-row tapered roller bearings of the first and second generation hub units. Whether it is a single-row or double-row hub bearing, the most common internal contact angle is 15° (see Fig.12 );

[0120] The vast majority of existing rail transit vehicles, whether it is the wheelset bearings of ordinary freight and passenger trains, or the axle box bearings of subway and high-speed rail EMUs, are double-row tapered roller bearings, and the most common internal contact angle is 10° (see Fig.13 );

[0121] A certain type of low energy consumption and long life bearing of the present invention has an internal contact angle of a=1.4° (see Fig.14 ). Through inquiry, the values ​​of all contact angles inside the above four types of motor vehicle bearings are as follows:

[0122] Table 1: Four widely representative values ​​of internal contact angles of motor vehicle wheel hub bearings

[0123] Classification of wheel hub bearings for motor vehicles Outer raceway taper angle a Inner raceway taper angle b Edge Angle c First, second and third generation ball bearing hub units for passenger cars 36° 36° 0° Tapered roller bearings for commercial vehicle wheel hubs (first and second generation hub units) 15° 11.4° 11.9° Rail transit wheelset (axle box) bearings 10° 8° 8.5° A new type of patented low energy consumption and long life bearing 1.4° 1° 1.37°

[0124] (1) Calculation of derived axial force of passenger car wheel hub bearing.

[0125] Although the development of passenger car wheel hub units has gone through the first, second and third generation stages, its internal structure has not changed. It is a double-row angular contact ball design with a contact angle of 36° (see Fig.11 ), when the car is moving in a straight line, the wheel hub bearing mainly bears the pure radial load Q a , pure radial load Q a Acting on the outer ring, the outer ring turns Q a Evenly distribute it to two rows of steel balls, and the two rows of steel balls then put Q a Transfer to the two inner rings, so that each row of bearings bears 0.5Qa The radial load is 36°, and each row of ball bearings generates 0.5Q at the inner and outer grooves. a The additional harmful derived axial load, the sum of the two column loads is 0.72Q a The steel ball and the inner and outer channels generate 0.72Q respectively. a The additional harmful derived axial load amounts to 72% of the total pure radial load applied to the four wheel hub bearings by the entire vehicle and wind resistance.

[0126] (2) Calculation of derived axial force of commercial vehicle wheel hub bearings.

[0127] Existing commercial vehicle wheel hub bearings are either two single-row tapered roller bearings or first and second generation double-row tapered roller bearing hub units (see Fig.12 ), when a pure radial force Q is applied to the outer ring a When the outer ring passes through two rows of rollers, Q a The force is evenly transmitted to the two inner rings, so as long as the force of one inner and outer raceway and roller is calculated, and then multiplied by 2, the force of the whole bearing can be obtained. In this case, it can be further simplified and the two inner and outer raceways and two rows of rollers can be calculated as one inner and outer raceway and one row of rollers, which is equivalent to a single-row bearing under pure radial force Q a The force analysis is shown in Fig.15 According to the parameters listed in Table 1 above, the semi-cone angle a of the outer raceway of the bearing is 15°, the semi-cone angle b of the inner raceway is 11.4°, and the angle c of the large rib is 11.9°. When the outer ring is subjected to a pure radial force Q a When the outer ring transfers the pure radial force Q through the rollers a The vertical and horizontal forces are respectively applied to the raceway and rib of the inner ring. The roller is in a state of equilibrium under the action of the three forces of the inner and outer raceways and the large rib, so:

[0128] Q n -Q i -Q y =0 (1)

[0129] Q a -Q e +Q x =0 (2)

[0130] Among them, Q n =Q m sina,Q a =Q m cosa, Q i =Q b sinb,Q e =Q b cosb,Qx =Q z sinc,Q y =Q z cosc, substituting these six equations into equations (1) and (2) and simplifying them, we obtain:

[0131] Q b =Q m (sinasinc+cosacosc) / (sinbsinc+cosccosb)(3)

[0132] Q z =Q m (sinacosb-cosasinb) / (sinbsinc+cosccosb)(4)

[0133] Substituting the previous angle values ​​of a, b, and c into (3) and (4) yields:

[0134]

[0135]

[0136] The radial force on the inner ring is:

[0137]

[0138] The axial force borne by the inner ring raceway is:

[0139] Q i =Q b sinb=Q m sinb=0.198Q m =0.198Q a / cos15°=0.21Q a

[0140] The axial force on the outer ring raceway is Q n =Q a taga=0.27Q a

[0141] The axial force on the large flange is Q y =Q z cosc=0.063Q m cos11.9°=0.06Q a

[0142] (3) Calculation of derived axial force of rail transit wheelset (axle box) bearings.

[0143] The existing rail transit wheel set (axle box) bearing is a double row tapered roller bearing (see Fig.13), when the EMU body applies a pure radial force Q to the outer ring a When the outer ring passes through two rows of rollers, Q a The force is evenly transmitted to the two inner rings. Since all the parameters of the two inner and outer raceways and two rows of rollers are the same, we only need to calculate the force of one inner and outer raceway and roller, and then multiply it by 2 to get the force of the whole bearing. In this case, we can further simplify it and calculate the two inner and outer raceways and two rows of rollers as one inner and outer raceway and one row of rollers, which is equivalent to a single-row bearing under pure radial force Q a The force analysis is shown in Fig.15 According to the parameters listed in Table 1 above, the semi-cone angle a of the outer raceway of the bearing is 10°, the semi-cone angle b of the inner raceway is 8°, and the angle c of the large rib is 8.5°. When the outer ring is subjected to a pure radial force Q a When the outer ring transfers the pure radial force Q through the rollers a Decomposed into vertical and horizontal forces applied to the inner raceway and flange respectively, the roller is in equilibrium under the action of the three forces of the inner and outer raceways and the large flange, so there are four equations (1), (2), (3), and (4) in Section (2). Substituting the angle values ​​of a, b, and c into equations (3) and (4) and simplifying them, we get:

[0144] Q b =Q m (sinasinc+cosacosc) / (sinbsinc+cosccosb)=Q m

[0145] Q z =Q m (sinacosb-cosasinb) / (sinbsinc+cosccosb)=0.035Q m

[0146] The radial force on the inner ring is:

[0147] Q e +Q x =Q b cosb+Q z sinc=0.99Q m +0.148×0.035Q m

[0148] =0.995Q a / cosa=1.01Q a

[0149] The axial force borne by the inner raceway is:

[0150] Q i =Qb sinb=Q m sinb=0.139Q m =0.139Q a / cos10°=0.14Q a

[0151] The axial force on the outer ring raceway is Q n =Q a taga=0.18Q a

[0152] The axial force on the large flange is Q y =Q z cosc=0.035Q m cosc=0.04Q a

[0153] (4) Calculation of the derived axial force of this low-energy consumption and long-life bearing.

[0154] When the outer ring of this low energy consumption and long life bearing is subjected to pure radial force Qa, the outer ring transmits Qa to the inner ring through the rollers. The force analysis is shown in Fig.16 According to the parameters listed in Table 1 above, the semi-cone angle a of the outer raceway of the bearing is 1.4°, the semi-cone angle b of the inner raceway is 1°, and the angle c of the large rib is 1.37°. When the outer ring is subjected to a pure radial force Q a When the outer ring transfers the pure radial force Q through the rollers a Decomposed into vertical and horizontal forces applied to the inner raceway and flange respectively, the roller is in equilibrium under the action of the three forces of the inner and outer raceways and the large flange, so there are four equations (1), (2), (3), and (4) in Section (2). Substituting the angle values ​​of a, b, and c into equations (3) and (4) and simplifying them, we get:

[0155] Q b =Q m (sinasinc+cosacosc) / (sinbsinc+cosccosb)=Q m

[0156] Q z =Q m (sinacosb-cosasinb) / (sinbsinc+cosccosb)=0.007Q m

[0157] The radial force on the inner ring is:

[0158]

[0159] The axial force borne by the inner ring raceway is:

[0160] Q n -Q y =Q m sina-Q z cosc=Q m (sina-0.007cosc)=0.017Q m =0.017Q a / cosa=0.017Q a

[0161] The axial force on the outer ring raceway is Q n =Q a tag a=0.024Q a

[0162] The axial force on the outer flange is Q y =Q z cosc=0.007Q m xosc=0.007Q a (5) Comparison of temperature rise and energy consumption of several bearings

[0163] The following conclusions can be drawn from the calculations in (1), (2), (3) and (4) above:

[0164] A. When the outer rings of the four bearings are subjected to pure radial force, the outer rings transmit almost the same radial force to the inner rings through the rollers, i.e. Q e =Q a , the radial force borne by the flange is too small to be considered.

[0165] B. From Table 2, we can see the following facts: When the four bearings are subjected to the same pure radial load Q a In the case of passenger cars, 0.72Q a Additional harmful derived axial loads, commercial vehicles generate 0.27Q a Additional harmful derived axial load, rail transit wheelset (axle box) bearings produce 0.18Q a In addition to the harmful derived axial load, this low energy consumption and long life bearing produces 0.024Q a Additional harmful derived axial loads: The additional harmful derived axial loads generated by these four bearings account for 72%, 27%, 18% and 2.4% of the pure radial effective load borne by the bearings, respectively. It can be seen that through innovative design, the patented bearing greatly reduces the additional harmful derived axial loads.

[0166] Table 2: The magnitude of harmful derived axial forces on the internal parts of existing bearings and bearings invented by the patentee, as well as the percentage of harmful axial load to effective load.

[0167]

[0168] These additional harmful derived axial loads generate a certain amount of friction F = μQ between the steel balls and the inner and outer raceways of ball bearings, and between the rollers and the inner and outer raceways and ribs of roller bearings. b (Q b represents the additional harmful derived axial force borne by each part of the bearing, μ is the friction coefficient), according to the torque calculation formula T = Fr, r represents the distance from the point of action of the friction force to the center line of the bearing, the axial friction torque between the various parts inside the bearing can be calculated; according to the relationship between power and torque: P = Tωω (P represents power, ω represents angular velocity), the power generated between the various parts inside the bearing can be calculated, and then according to the calculation formula of work and power: W = Pt (t represents time), the above three formulas are sorted out to obtain the following formula: W = Q b μrωt, according to the first law of thermodynamics, that is, the law of conservation of energy, 100% of the work done by these derived axial loads is converted into heat, from which we can draw the following conclusions: the temperature rise and energy consumption caused by the bearing bearing the additional harmful derived axial load are proportional to the derived axial load, friction coefficient, size, speed and running time borne by the bearing. Under the premise of the same friction coefficient, size, speed and running time, the only way to reduce the temperature rise and energy consumption is to reduce the additional harmful derived axial load Q b One of the innovative designs of this patented bearing is to significantly reduce the contact angle of the bearing, so that the additional harmful derived axial load Q borne by each bearing part is b It is reduced to the limit, resulting in a significant reduction in temperature rise and energy consumption, completely eliminating the root cause of "hot shaft" and "hot cut shaft" in the wheelset (axle box) bearings of rail transit vehicles, and completely eliminating the overheating problem in the wheel hub of motor vehicles.

[0169] C. Whether it is the wheel hub bearing of a commercial vehicle or the wheel set (axle box) bearing of a rail transit vehicle, the heat generating part 1204 is shown in the diagram when it is working. Fig.12In addition to the normal heating caused by the friction between the various parts inside the bearing due to the radial force, the heating caused by the friction between the various parts due to the axial force is abnormal heating. Both theoretical analysis and experiments have verified that the part of the existing bearing that generates the most heat is between the ball base surface 701 of the roller and the outer rib 3. Because there is sliding friction between the ball base surface 701 of the roller and the outer rib 3, its friction coefficient is much larger than the rolling friction coefficient; although the rolling friction heat generated by the axial force between the inner and outer raceways and the rollers is roughly the same, the surface area of ​​the outer ring is about twice that of the inner ring, and the outer ring is either exposed to the air or the outer ring is exposed to the air. When exposed to the air, or in the wheel hub or axle box, the heat can be easily dissipated or transferred. However, since the inner ring is installed on the axle, whether it is a solid shaft or a hollow shaft, the heat is not easy to dissipate. Therefore, the heat generated by the inner ring and the roller is much greater than that of the outer ring. In order to prevent the bearing from "stuck" or "stuck", the clearance can only be increased. This is the reason why "hot shafts" and "thermal broken shafts" always occur in rail transit wheelset (axle box) bearings; due to abnormal temperature rise caused by long-term heating, the grease evaporates and oxidizes faster, and then ages and solidifies and fails, so motor vehicles always need to replace the grease frequently, which is the so-called maintenance.

[0170] In addition to the significant reduction of the additional harmful derived axial force discussed in Section B above, the low energy consumption and long life bearing has a more reasonable distribution of internal heat source or temperature field (see heating part 703). Fig.17 ), the outer rib of the low-energy consumption and long-life bearing moves from the inner ring to the edge of the outer ring, and the heat generated by the inner ring is less than the heat generated by the outer ring and the roller. Since the surface area of ​​the outer ring is about twice that of the inner ring, and the outer ring is either exposed to the air or in the wheel hub or the axle box, the heat can be easily dissipated or transferred, so the heat dissipation effect is much better than that of the existing bearings. In addition, since the rollers of the low-energy consumption and long-life bearing are always in contact with the inner and outer raceways, the heat on the inner ring can also be easily dissipated or transferred through the rollers and the outer ring. Therefore, the temperature rise of the inner and outer rings and the rollers is relatively low, and "stuck" or "stuck" will not occur.

[0171] In addition, the temperature rise is greatly reduced, the evaporation and oxidation rate of the grease is slowed down or even eliminated, the life of the bearing is greatly improved, and the energy consumption of driving the motor vehicle is reduced. It is worth noting that this low-energy consumption and long-life bearing is suitable for various motor vehicle hubs such as automobiles, tricycles, motorcycles, agricultural machinery, tractors, and construction machinery, and is also suitable for installation in ordinary freight and passenger trains, as well as for use as axle box bearings for subway and high-speed rail EMU wheelsets, and is also suitable for various high-speed and heavy-loaded mechanisms, especially those with large axial forces and the need to control bearing clearance.

[0172] In addition, the oil film inside the low-energy consumption and long-life bearing is always in normal working condition, which greatly prolongs the life of the bearing and lubricating oil (grease). In many working conditions, due to the existence of clearance, the existing bearings make the load that should be borne evenly and uniformly by all rolling elements and inner and outer raceways become partial super loads borne by some parts, and some parts bear super cycle loads. When the super load is greater than the oil pressure formed between the rolling elements and the inner and outer raceways, the oil film cannot be formed between the rolling elements and the inner and outer raceways, and dry friction is generated, which seriously affects the lubrication effect of the bearing, resulting in shortened bearing life and failure of lubricating oil (grease). When the low-energy consumption and long-life bearing is working, since all rolling elements bear the load evenly, the lubricating oil (grease) accumulates in the wedge-shaped gap between the rolling elements and the inner and outer raceways and generates oil pressure. When the oil pressure exceeds the load borne by the rolling elements, the rolling elements are lifted, and an oil film is formed between the rolling elements and the inner and outer raceways, which greatly prolongs the life of the bearing and lubricating oil (grease).

[0173] Embodiment 19:

[0174] The main structure of this embodiment is the same as that of Embodiment 18. Furthermore, this low-energy consumption and long-life bearing is used in a commercial wheel end assembly.

[0175] As can be seen from Table 2, the contact angle inside the bearings of existing commercial vehicle wheel hub bearings, whether they are two single-row tapered roller bearings or the first and second generation commercial vehicle wheel hub units, is mostly about 15°. This angle is designed to be too large, resulting in the existing wheel hub bearings bearing a large additional harmful derived axial load, which accounts for 27% of the weight of the commercial vehicle itself and the wind resistance. To drive this 27% additional harmful derived axial load, the commercial vehicle must consume the same proportion of energy, and 100% of the consumed energy is converted into heat, resulting in serious heating of existing commercial vehicle wheel hub bearings, especially the temperature rise of the inner ring and the roller is higher than that of the outer ring, and the grease evaporates, oxidizes, ages, and solidifies seriously. The grease (oil) needs to be replaced in a short time, which is the so-called maintenance. It is expensive and time-consuming, and seriously affects the life of the wheel hub bearing. In order to prevent the wheel hub bearing from "stuck" or even "stuck" due to heating, the bearing must have sufficient clearance, and the clearance seriously affects the life of the wheel hub bearing (see Fig.18 ), according to practical experience, if the axial clearance is 0.15mm, the life of the hub bearing is only about 50% of the life when the clearance is 0. The clearance of existing commercial vehicle hub bearings is generally above 0.15mm (including the influence of the position tolerance of each part on the clearance), which is why the life of existing commercial vehicle hub bearings is very short. In addition, the design of commercial vehicle wheel end assembly is backward, with many parts, large volume, complex structure and process, and high manufacturing cost. This low energy consumption and long life bearing can solve the above problems.

[0176] (1) Application of this low-energy consumption and long-life bearing in the wheel end assembly of the steering axle of commercial vehicles.

[0177] The application of this low energy consumption and long life bearing in the wheel end assembly of the commercial vehicle steering axle is shown in Fig.19 Due to the actual working conditions, the low energy consumption and long life bearings on the steering axle wheel end assembly of commercial vehicles are Figure 1 The low energy consumption and long life bearings are different as follows:

[0178] The outer oil seal 2 is removed from the low-energy consumption and long-life bearing, and is made into an outer oil seal separately and placed on the outside of the outer rib 3. This oil seal can not only seal the grease inside the bearing from leaking out, but also transmit the axial force; or the outer rib 3 and the outer oil seal 2 are optimized into a single part, which is more convenient to manufacture. The inner oil seal 8 of the bearing is also removed from the low-energy consumption and long-life bearing, and is made into an outer oil seal separately and placed inside the wheel hub, which serves the purpose of sealing the grease inside the bearing from leaking out. The rim and the brake disc (or brake drum) are fastened to the wheel hub (or the flange of the wheel hub) by screws.

[0179] Furthermore, the steering axle wheel end assembly of this commercial vehicle is upgraded (see Fig. 20 ),exist Fig.19 On the basis of the present invention, the outer ring of the low-energy consumption and long-life bearing and the wheel hub are integrated into a part 1408, and the rim (or the rim adapter plate) and the brake disc (or the brake drum) are fastened to the wheel hub (or the flange of the wheel hub) by screws.

[0180] (2) Application of this low-energy consumption and long-life bearing in the wheel end assembly of the commercial vehicle drive axle.

[0181] The application of this low energy consumption and long life bearing in the wheel end assembly of the commercial vehicle drive axle is shown in Fig.21 Due to the actual working conditions, the low energy consumption and long life bearings on the wheel end assembly of the commercial vehicle drive axle are Figure 1 The low energy consumption and long life bearings are different as follows:

[0182] In addition to the external oil seal and external flange Fig.21 In addition to the structure, the other structures in the previous section (1) can also be referred to. The inner oil seal 8 of the bearing is removed from the low-energy consumption and long-life bearing of the present invention, and is made into an outer oil seal separately and placed inside the wheel hub to seal the grease inside the bearing and prevent it from leaking out. The wheel rim and the brake disc (or brake drum) are fastened to the wheel hub (or the flange of the wheel hub) by screws.

[0183] Furthermore, the commercial vehicle drive axle wheel end assembly is upgraded (see Fig. 22 ),exist Fig.21On the basis of the present invention, the outer ring of the low energy consumption and long life bearing and the wheel hub are integrated into a part 1506, and the rim and the brake disc (or brake drum) are fastened to the wheel hub (or the flange of the wheel hub) by screws.

[0184] Embodiment 20:

[0185] The main structure of this embodiment is the same as that of Embodiment 18. Furthermore, the low-energy consumption and long-life bearing is used in the wheel end assembly of a passenger car.

[0186] As we all know, existing passenger car wheel hub bearings generally use the first, second, and third generation hub units, most of which have double-row angular contact ball bearing structures (see Fig.11 ), the contact angles of the two rows of steel balls and the inner and outer raceways are mostly 36°, which is designed to be too large, causing the existing wheel hub bearings to bear a large additional harmful derived axial load. As shown in Table 2, the axial load accounts for 72% of the weight of the passenger car itself and the wind resistance. To drive this 72% additional harmful derived axial load, the passenger car must consume the same proportion of energy, and 100% of the consumed energy is converted into heat, resulting in serious heating of the existing passenger car wheel hub bearings, serious grease evaporation, oxidation, aging, and solidification, and extremely serious energy waste, which seriously affects the life of the wheel hub bearings. In addition, although the third-generation wheel hub unit is the highest-level wheel hub bearing currently installed in large quantities, it has many parts, poor moment rigidity, large size, complex structure, high process and manufacturing difficulties, and high cost. The low-energy consumption and long-life bearing can solve the above problems.

[0187] Since the third-generation wheel hub unit is currently the highest-level wheel hub bearing installed in large quantities, this low-energy consumption and long-life bearing also uses the third-generation wheel hub unit as an example to illustrate the problem. The application of this low-energy consumption and long-life bearing in the passenger car wheel end assembly can be seen in Fig.23 Due to the actual working conditions, the low energy consumption and long life bearings on the passenger wheel end assembly are Figure 1 The low energy consumption and long life bearings are different as follows:

[0188] The inner and outer rings of the bearing are designed with flanges. Fig.23 In addition to the structure, you can also refer to the other structures in the previous section (1). The second-generation hub unit is just designed with a flange on the outer ring of the low-energy consumption and long-life bearing, and its interior is still the structure of the low-energy consumption and long-life bearing. Therefore, the first, second and third generation hub units for passenger cars that use the innovative design of the low-energy consumption and long-life bearing are all protected by patents.

[0189] Furthermore, the passenger car wheel end assembly is upgraded to the fourth generation wheel hub unit (see Fig.24), on the basis of the third generation wheel hub unit, the universal joint cover 17 is mechanically connected to the inner ring of the low energy consumption and long life bearing, which saves the processing of internal and external splines and saves raw materials.

[0190] Embodiment 21:

[0191] The main structure of this embodiment is the same as that of Embodiment 18. Furthermore, this low-energy consumption and long-life bearing is used in rail transit vehicles.

[0192] Most of the existing ordinary freight and passenger train wheel bearings, subway and high-speed rail EMU axle box bearings are double-row tapered roller bearings (see Fig.13 ), and most of them are imported bearings, or foreign-funded domestic production, which is a typical "bottleneck" project. The contact angle of the existing wheel set (axle box) bearings of rail transit vehicles is mostly 10°. This angle is designed to be too large, resulting in the existing wheel set (axle box) bearings bearing a large additional harmful derived axial load. As shown in Table 2, this axial load accounts for 18% of the weight of the rail transit vehicle itself and the wind resistance. To drive this 18% additional harmful derived axial load, the rail transit vehicle must consume the same proportion of energy. These consumed energies are 100% converted into heat, resulting in serious heating of the existing rail transit wheel set (axle box) bearings, serious evaporation, oxidation, aging, and solidification of the grease, and serious energy waste, which seriously affects the life of the rail transit wheel set (axle box) bearings. In addition, the existing rail transit wheel set (axle box) bearings are large in size, complex in structure, difficult in process and manufacturing, and high in cost. This low-energy consumption and long-life bearing can solve the above problems.

[0193] This low energy consumption and long life bearing is used as a wheel set (axle box) bearing (see Figure 1 ), can be installed on the axle of rail transit vehicles. Through innovative internal structure design, this low-energy consumption and long-life bearing not only completely solves the abnormal peeling of rail transit wheel set (axle box) bearing parts as detailed above, but also significantly reduces the additional harmful derived axial load borne by the existing wheel set (axle box) bearing from 18% of the radial load it bears to 2.4%, correspondingly reducing the heat and energy consumption in the same proportion. The beneficial effects of this innovation alone are: significantly reducing temperature rise, significantly reducing energy consumption, significantly reducing grease evaporation, oxidation, curing, aging and other problems; and completely eliminating the problem that the existing bearing structure easily causes the grease to produce a "pumping effect". In addition, it also completely solves the stubborn problems that have plagued the domestic and foreign rail transit industry for more than 200 years, namely the "hot shaft", "hot cutting shaft" and "burning shaft" problems. By optimizing the distribution of the internal temperature field of the bearing, the temperature rise of each component of the bearing is uniform, the heat transfer is smoother, and the heat dissipation effect is more obvious.

[0194] The detailed analysis is as follows (see Figure 1and 14 ): As we all know, in addition to the temperature rise, the temperature rise of each part of the existing rail transit wheelset (axle box) bearings is not the same. The contact angle of the existing bearings is 10°. In theory, there is sliding friction between the ball base surface of the roller and the large rib, and the sliding friction coefficient is much higher than the rolling friction coefficient, which leads to the highest heat generation and temperature rise between the roller and the large rib. In addition, the friction temperature rise between the roller and the inner and outer raceways is almost the same. Due to the large clearance, the roller only contacts the outer raceway once in a very narrow load-bearing area of ​​the outer ring for each rotation. The heat of the roller is difficult to transfer to the outer ring. Therefore, the temperature rise of the inner ring and roller of the existing bearing is greater than that of the outer ring; the actual operation of the bearing just verifies this. According to the above theory, the existing wheelset (axle box) bearings have an interference fit between the inner ring and the axle, and the heat of the inner ring can be easily transferred to the axle, causing the temperature of the axle to rise along with the inner ring. On the contrary, since the outer ring is either tightly fitted with the axle box or most of the outer circle is exposed to the air, and the area of ​​the outer ring is about twice that of the inner ring, the heat generated by the outer ring can be easily dissipated into the air directly or through the axle box. As time accumulates, when the temperature of the inner ring and the axle rises to a certain level, "hot axle", "burning axle" and "hot cutting axle" accidents occur. Since the outer rib 3 and the outer ring 5 of the low-energy consumption and long-life bearing are integrated or have two separate parts, the inner ring has no rib, and the heat generated is less than that of the outer ring. Under the premise that the additional harmful heat generated by the entire bearing is greatly reduced from 18% to 2.4%, since the heat dissipation area of ​​the outer ring is larger than that of the inner ring, even if the heat generated by the outer ring and the outer rib is greater than that of the inner ring, since the outer ring is either tightly matched with the axle box or most of the outer circle is exposed to the air, the heat can be easily dissipated directly or through the axle box to the air. In addition, since all rollers are always in contact with the inner and outer raceways and the outer rib with zero clearance, the heat of all parts of the bearing can be easily dissipated to the air through the outer ring.

[0195] Embodiment 22:

[0196] The main structure of this embodiment is the same as that of Embodiment 18. Furthermore, this low-energy consumption and long-life bearing is used in the transmission mechanism of the rail transit gearbox.

[0197] Many transmission mechanisms, especially gear transmission mechanisms, require roller bearings to bear the load when the gear mechanism transmits high-speed and heavy loads. Since helical gears have many advantages over spur gears when transmitting high-speed and heavy loads, the existing high-speed and heavy-load gear transmission mechanisms either use tapered roller bearings as supports or use a combination of cylindrical roller bearings and thrust ball bearings. Regardless of which mode is used, due to high speed and heavy loads, the bearings generate relatively more heat, and clearance is required as with the existing bearings in various occasions mentioned above. The clearance also leads to a significant shortening of the bearing life, as well as increased noise, temperature rise and vibration. The existing rail transit gearbox bearings in this embodiment are all imported bearings, which are also typical "bottleneck" projects. Since China has the largest number of subways and high-speed rail EMUs in the world, each standard subway or high-speed rail EMU with 8 carriages needs to be equipped with 16 gearboxes. Therefore, the subway and high-speed rail EMU gearboxes are used as examples to illustrate that the problem has broad commonality and is of great practical significance.

[0198] The existing main high-speed EMU gearboxes all use a first-stage helical gear transmission (see Fig.25 ), this transmission structure is simple, with few shaft systems, few bearings, and high transmission efficiency. It is most commonly used on high-speed EMUs. The input shaft 21 generally uses a four-point contact ball bearing 20 plus two cylindrical roller bearings 18. The four-point contact ball bearing 20 bears the axial load of the entire input shaft 21, and all radial loads on the input shaft are borne by the two cylindrical bearings. Therefore, in the design of the bearing seat, the bearing seat and the outer ring of the four-point contact ball bearing adopt a clearance fit; the bearing seat and the two cylindrical bearings adopt a transition fit. This arrangement is safer and more reliable than using two tapered bearings on the input shaft, because the input shaft has a high speed, and the tapered bearing needs to bear radial and axial loads at the same time when it is running. The rolling element is in rolling contact with the inner ring raceway and sliding contact with the retaining edge at the same time, and the heat generated is higher, which puts higher requirements on the tapered bearing. Therefore, the current high-speed EMU gearbox input shaft bearing is mainly based on the four-point contact ball bearing plus two cylindrical bearings arrangement.

[0199] The output shaft of the gearbox has a much lower speed than the input shaft and has to bear a large axial load, so the bearings are generally paired with tapered bearings. The existing tapered bearings can withstand high axial forces and also generate a lot of heat. After the tapered bearings are installed, the axial clearance needs to be adjusted to adapt to the clearance reduction caused by the working temperature rise. Due to high speed and heavy load, the radial clearance of the cylindrical roller bearing of the input shaft is 0.065-0.1mm, and the radial clearance of the tapered roller bearing 19 of the output shaft is 0.16-0.22mm. Such a large clearance seriously affects the life of the bearing (see Fig.18 ), while the noise, vibration and temperature rise of the entire gearbox also increase.

[0200] The use of this low energy consumption and long life bearing can solve the above problems (see Fig.26 ). First of all, since the clearance of this low-energy consumption and long-life bearing is 0, the life of the gearbox bearing is greatly extended, and the mileage of the gearbox "planned maintenance" is also greatly extended. At the same time, the effect of reducing noise, vibration and temperature rise is also very significant. Since the input shaft uses two low-energy consumption and long-life bearings with a contact angle below 3°, these two bearings, like the existing cylindrical roller bearings, can withstand high speeds and large radial loads, as well as small axial loads, and the existing three bearings are reduced to two; since the output shaft uses two low-energy consumption and long-life bearings with a contact angle designed according to the ratio of the radial load and axial load borne by the large gear, these two bearings, like the existing tapered roller bearings, can withstand large axial loads and large radial loads, and the contact angle is optimized to achieve the best transmission efficiency.

[0201] Embodiment 23:

[0202] The main structure of this embodiment is the same as any one of the embodiments 1 to 22. Furthermore, the low energy consumption and long life bearing is in the best working state of zero clearance when working, which means that the clearance between the ball base surface 701 of the roller 7 and the end surface of the step portion 302 of the outer rib 3, the conical surface of the roller 7 and the inner raceway 101 of the inner ring 1 and the outer raceway 501 of the outer ring 5 is always 0 (see Figure 8 ).

[0203] The axial clearance T value between the small end face 702 of the roller 7 and the working face 601 of the small rib 6 of the low energy consumption and long life bearing is (see Fig.14 ) size has nothing to do with the load and life of the bearing. Only when the vehicle makes a sharp turn, the centrifugal force generated causes axial relative movement between the inner ring 1, the outer ring 5 and the outer flange 3, and the spherical base surface 701 and the small end surface 702 of the roller 7 are in contact with the step portion 302 of the outer flange 3 and the working surface 601 of the small flange 6 at the same time, respectively, to transmit the axial force to the inner ring 1 or the outer ring 5 and the outer flange 3. After turning the corner, the centrifugal force or axial force disappears, the bearing only bears pure radial load, and the bearing returns to the optimal working state of 0 clearance.

[0204] The size of the axial clearance T between the small end face 702 of the roller 7 and the working face 601 of the small rib 6 is only related to the temperature rise of the bearing parts. Since the temperature rise of the low-energy consumption and long-life bearing is greatly reduced compared with the existing bearings, and the heat generation of each part is almost the same, although the inner and outer rings have a certain amount of expansion, in most cases, only one of the inner or outer ring is axially positioned and clamped, and the other axial degree of freedom is limited by the former, such as commercial vehicle wheel hub bearings (see Figures 19 to 24), whose common feature is that the inner ring 1 is axially positioned and clamped. When the inner ring 1, the outer ring 5, the roller 7 and the outer rib 3 are heated and expanded, since the elongation in the length direction due to thermal expansion is almost equal, the axial clearance T value between the small end face 702 of the roller 7 and the working surface 601 of the small rib 6 is almost affected; a major feature of the internal structure design of the low-energy consumption and long-life bearing is that the inner ring 1, the outer ring 5 and the roller 7 are evenly heated, so that the expansion of the inner and outer rings and the rollers is almost equal in both radial and axial directions. Even if the radial expansion of the inner ring 1 and the roller 7 is greater than the radial expansion of the outer ring 5, the outer ring 5 and the outer rib 3 will drive the roller 7 to move toward the small head 102 of the inner ring 1, and the T value mentioned above will be slightly reduced; in addition, since the outer ring and the wheel hub and the axle box are transitional or small clearance fit, if the outer ring expands slightly due to temperature rise, it only reduces the gap between the outer ring and the wheel hub and the axle box, and the bearing still works normally.

Claims

1. A low energy consumption and long life bearing, characterized in that: It comprises an inner ring (1), an outer rib (3), a retainer (4), an outer ring (5), a small rib (6) and a plurality of tapered rollers (7); The inner ring (1) is a structure with a cone shape in the middle, a cylindrical shape at both ends, and a cylindrical hole inside. The end with a smaller radius of the cylindrical segments at both ends is marked as a small head end (102), and the end with a larger radius is marked as a large head end (103). The area between the large head end (103) and the small head end (102) is marked as an inner raceway (101); The small rib (6) is a hollow cylindrical structure, which is mounted on the outer cylindrical surface of the small head end (102) of the inner ring, and a working surface (601) is provided on the end surface of the small rib (6) facing the large head end (103); The outer ring (5) is a hollow rotating body structure; the inner hole of the outer ring (5) includes an outer raceway (501) section and a cylindrical section (502); the inner hole at the outer raceway (501) section is in a cone shape; the end of the outer raceway (501) section with a smaller radius is recorded as a small diameter end, and the end with a larger radius is recorded as a large diameter end; the small diameter end is connected to the cylindrical section (502); The outer rib (3) is an annular structure as a whole, comprising an outer rib body (301) and a step portion (302); one end of the outer rib body (301) is connected or communicated with the large diameter end of the outer raceway (501), and an annular step portion (302) is provided on the inner side wall at the intersection position; When the inner ring (1) and the outer ring (5) are assembled together, the inner ring (1) is located in the inner hole of the outer ring (5), so that the inner raceway (101), the outer raceway (501) and the step portion (302) form a friction working area; A retainer (4) is installed in the friction working area; A plurality of the tapered rollers (7) are located in the friction working area and are evenly separated by a retainer (4) window; when working, the tapered rollers (7) rotate in the friction working area against the inner raceway (101), the outer raceway (101) and the step portion (302) of the outer rib.

2. A low energy consumption and long life bearing according to claim 1, characterized in that: The outer diameter of the inner raceway (101) section gradually increases from the small end (102) to the large end (103).

3. A low energy consumption and long life bearing according to claim 1, characterized in that: The semi-cone angle of the outer raceway (501) is a=1° to 9°.

4. A low energy consumption and long life bearing according to claim 1, characterized in that: The tapered roller (7) is a cone-shaped structure, and the tapered surface of the tapered roller (7) is in contact with the inner raceway (101) and the outer raceway (501) with zero clearance.

5. The low energy consumption and long life bearing according to claim 1, characterized in that: The tapered roller (7) is a cone-shaped structure, and the end with a larger radius is marked as a spherical base surface (701), and the spherical base surface (701) is in contact with the step portion (302).

6. A low energy consumption and long life bearing according to claim 1, characterized in that: The inner ring (1) and the small rib (6) are an integrally formed structure.

7. The low energy consumption and long life bearing according to claim 1, characterized in that: The small rib (6) and the inner ring (1) are two parts; A plurality of screw holes are provided on the outer cylindrical surface of the small rib (6). When the small rib (6) is mounted on the small head end (102) of the inner ring, a cylindrical pin which is interference fit or overfit with the screw hole is placed in the screw hole, and the cylindrical pin is pushed to move in the screw hole by a set screw. The small rib (6) is axially positioned and locked on the inner ring (1) by a thread on one end of the cylindrical pin away from the set screw.

8. The low energy consumption and long life bearing according to claim 1, characterized in that: The outer ring (5) and the outer rib (3) are two parts or an integrally formed structure.

9. The low energy consumption and long life bearing according to claim 1, characterized in that: The bearing further comprises an outer oil seal (2) and an inner oil seal (7). The outer oil seal (2) is arranged between the inner ring big head end (103) and the outer rib (3), and is interference fit with the inner hole of the outer rib body (301), and is interference seal fit with the outer cylindrical surface of the inner ring big head end (103); The inner oil seal (8) is arranged between the small rib (6) and the outer cylindrical section (502), and is interference fit with the inner hole of the outer cylindrical section (502), and is interference sealing fit with the outer cylindrical surface of the small rib (6).

Images