WO2022016832A1

WO2022016832A1 - Self-aligning roller bearing for axial or radial eccentric loading operation conditions, and heat treatment process

Info

Publication number: WO2022016832A1
Application number: PCT/CN2021/071038
Authority: WO
Inventors: 蔡梅贵; 蔡玉铨; 蔡欣怡; 张明远
Original assignee: 山东省宇捷轴承制造有限公司
Priority date: 2020-07-22
Filing date: 2021-01-11
Publication date: 2022-01-27
Also published as: CN111720434A

Abstract

A self-aligning roller bearing for axial or radial eccentric loading operation conditions, pertaining to the technical field of bearings. The roller bearing comprises: an outer ring (100); an inner ring (200); and two arrays of symmetrical spherical rollers retained by a retainer between two inner raceways and a shared outer raceway. The two arrays of rollers have different lengths, such that the two arrays of rollers constitute long rollers (310) and short rollers (320), respectively. The maximum diameter of the short rollers (320) is less than the maximum diameter of the long rollers (310). The center of the spherical surface of the outer raceway is offset from an axial center of the bearing toward the end of the short rollers (320) in an axial direction of the bearing. Further disclosed is a heat treatment process for a self-aligning roller bearing for axial or radial eccentric loading operation conditions. The self-aligning roller bearing for axial or radial eccentric loading operation conditions and the heat treatment process increase the allowable deflection angle of the bearing, achieves contact stress uniformity for rollers on both sides and on the raceways, improves the overall service life of the bearing, and offers high hardness, size stability, and wear resistance of the bearing at high temperatures, thereby being applicable as main transmission box output bearings of marine engineering equipment, metallurgical machinery, electric power equipment, special vehicles, axial fans, and the like.

Description

A spherical roller bearing suitable for axial and radial eccentric load conditions and its heat treatment process

technical field

The invention relates to a self-aligning roller bearing suitable for axial and radial eccentric load conditions and a heat treatment process, belonging to the technical field of bearings.

Background technique

Spherical roller bearings have good self-aligning performance, mainly bear radial load, but also bear certain axial load. The conventional double row symmetrical spherical roller bearing (as shown in Figure 1) is mainly composed of the outer ring (1), the inner ring (2), and the outer ring (1) and the inner ring (2) by the cage (31). ) between two rows of rollers (3), usually the maximum deflection angle allowed to rotate the axis of the inner ring relative to the axis of the outer ring is 1.5°. When the deflection angle of the axis of the inner ring relative to the axis of the outer ring is greater than 1.5° during use, the roller will protrude from the end face of the outer ring, reducing the bearing area of the roller and uneven contact stress, resulting in premature fatigue failure of the bearing; The increased deflection angle of the ring axis relative to the outer ring axis may also cause the rollers to rotate out of the bearing face, causing the rollers to interfere with surrounding parts.

In addition, in marine engineering equipment, metallurgical machinery, electric power equipment, special vehicles, axial fans and other equipment, the output shaft of the main drive gearbox is often placed on one side to bear large eccentric radial and axial loads, while the other side bears small axial loads. , radial load conditions. Conventional double-row symmetrical spherical roller bearings can bear the same radial load or one-way axial load capacity of each row of rollers. A large difference in stress will cause early fatigue spalling and damage to the bearing rollers and raceways at one end of the bearing with large radial and axial loads, resulting in a shortened overall bearing life.

Therefore, there is an urgent need for a spherical roller bearing with a large deflection angle and capable of bearing large axial and radial eccentric loads, which is suitable for axial and radial eccentric loads to solve the above problems.

It should be noted that the above content belongs to the technical cognition category of the inventor, and does not necessarily constitute the prior art.

SUMMARY OF THE INVENTION

The purpose of the present invention is to solve the problems existing in the prior art, and to provide a spherical roller bearing suitable for axial and radial eccentric load conditions and a heat treatment process, and the obtained spherical roller bearing can have the same Under the condition of external dimensions, it can bear larger axial and radial eccentric loads; or under the same load, the bearing size can be reduced to achieve lightweight design, energy saving and environmental protection.

The present invention realizes above-mentioned purpose by adopting following technical scheme:

In one aspect, the present invention provides a spherical roller bearing suitable for axial and radial eccentric load conditions, including:

an outer ring, the inner peripheral surface of the outer ring is formed with a spherical outer raceway;

an inner ring, two inner raceways are formed on the outer peripheral surface of the inner ring;

Two rows of symmetrical spherical rollers are held between the two inner raceways and the shared outer raceway by a cage, and the lengths of the two rows of rollers are different so that the two rows of rollers constitute long rollers and short rollers respectively , the maximum diameter of the short roller is smaller than the maximum diameter of the long roller;

and a middle retaining ring arranged between the long roller and the short roller;

The ball center of the spherical surface on which the outer raceway is located is deviated from the axial center of the bearing toward one end of the short roller along the axial direction of the bearing.

Optionally, the middle retaining ring is arranged between the two inner raceways and is located on the inner side of the cage in the circumferential direction.

Optionally, the middle retaining ring is a fixed middle retaining ring, the longitudinal section of the middle retaining ring is similar to an isosceles or non-isosceles trapezoid shape, the short side of the trapezoid is fixedly connected with the outer peripheral surface of the inner ring, and the sides of the trapezoid are Symmetrical or asymmetrical tilt.

Optionally, the middle retaining ring is a floating middle retaining ring, the longitudinal section of the middle retaining ring is in the shape of a trapezoid, and the angle between the trapezoidal side waist on one side of the long roller and the axial center line of the bearing is less than or equal to one of the short rollers. The angle between the trapezoidal side waist of the side and the axial centerline of the bearing.

Optionally, the edge of the end surface of the long roller in contact with the middle retaining ring and the edge of the end surface of the short roller in contact with the middle retaining ring are both spherical base surfaces.

Optionally, the cage includes a long-roller cage and a short-roller cage, and inner ends of the long-roller cage and the short-roller cage respectively abut on the middle retaining ring.

Optionally, the contact angle of the long roller is greater than or equal to the contact angle of the short roller.

Optionally, the axial width of the inner ring is smaller than the width of the outer ring.

Optionally, the end surface of the outer ring at one end of the long roller is provided with an annular recess surrounding the inner hole of the outer ring.

On the other hand, the present invention also provides the heat treatment process of the spherical roller bearing suitable for axial and radial eccentric load conditions, including the following steps:

(1) Quenching: Preheat the outer ring, inner ring and roller at 835-845°C, then increase the quenching heating temperature to 1100-1105°C, and use salt bath quenching;

(2) Tempering: multiple high temperature tempering is adopted, and the tempering temperature is 235-245 °C.

The beneficial effects of this application include but are not limited to:

The invention provides a self-aligning roller bearing suitable for axial and radial eccentric load conditions and a heat treatment process. The middle retaining ring is arranged between them to guide the attitude of the rollers, and the edge of the end face where the long and short rollers are in contact with the middle retaining ring is set as a spherical base surface, etc., which increases the deflection angle of the spherical roller bearing. The contact stress between the rollers and the raceway on both sides is uniform, the friction between the roller end face and the fixed middle retaining ring is reduced, and the overall service life of the bearing is improved. The spherical roller bearing provided by the present invention can bear larger axial and radial eccentric loads under the condition of the same external dimension, or under the condition of bearing the same load, the inner diameter, outer diameter and roller diameter of the bearing can be reduced, and the bearing The weight is reduced, and the size of the shaft and seat hole matched with the bearing is correspondingly reduced, which realizes the lightweight design, energy saving and environmental protection. Moreover, by improving the heat treatment process, the spherical roller bearing still has high hardness, stable size and high wear resistance at high temperature, and is suitable for main drives such as marine engineering equipment, metallurgical machinery, electric power equipment, special vehicles, and axial fans. Box output bearing.

Description of drawings

The drawings described herein are used to provide further understanding of the present application and constitute a part of the present application. The schematic embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation of the present application. In the attached image:

Fig. 1 is the structural schematic diagram of the traditional spherical roller bearing;

FIG. 2 is a schematic structural diagram of a spherical roller bearing suitable for axial and radial eccentric load conditions provided by the application;

3 is a schematic structural diagram of a spherical roller bearing using a floating middle retaining ring that is suitable for axial and radial eccentric load conditions provided by the application;

4 is a schematic view of the end surface structure of the short roller in the spherical roller bearing suitable for axial and radial eccentric load conditions provided by the application;

FIG. 5 is a schematic view of the split structure of the spherical roller bearing provided by the application;

Fig. 6 is the schematic diagram that the spherical roller bearing is installed in the concrete mixer;

7 is a diagram showing the maximum stress distribution on the rollers when the same load (the combined load of the axial load and the radial load) is applied to the spherical roller bearing of the embodiment and the comparative example;

Fig. 8 is a diagram showing the contact stress distribution between the inner ring and the outer ring at different length positions of the roller when the same load (the combined load of the axial load and the radial load) is applied to the spherical roller bearing of the embodiment and the comparative example ;

In the figure, 100, outer ring; 110, annular recess; 200, inner ring; 310, long roller; 311, long roller cage; 320, short roller; 321, short roller cage; 400, middle block circle; 500, can body.

detailed description

In order to clearly illustrate the technical features of the solution, the present invention will be described in detail below through specific embodiments and in conjunction with the accompanying drawings.

It should be noted that many specific details are set forth in the following description to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited by the specific embodiments disclosed below.

On the one hand, as shown in FIG. 2 , a spherical roller bearing suitable for axial and radial eccentric load conditions provided by the present invention includes an outer ring 100 , an inner ring 200 , and the outer ring 100 and the inner ring 200 are retained by a cage. Two rows of symmetrical spherical rollers between the inner rings 200 . It can be understood that the spherical roller means that the rolling surface of the roller is spherical, and the outer peripheral surface of the symmetrical spherical roller is symmetrical about a plane passing through the axial center of the roller and perpendicular to the axis of the roller.

Among them, a spherical outer raceway is formed on the inner peripheral surface of the outer ring 100 , and two inner raceways are formed on the outer peripheral surface of the inner ring 200 . The two rows of rollers share the outer raceway, the two inner raceways and the shared outer raceway enclose two raceways that accommodate the two rows of rollers, respectively, and the two rows of rollers are held in the two raceways by the cage, respectively. The outer ring 100 and the inner ring 200 are caused to roll relative to each other. Moreover, the radian of the outer raceway and the inner raceway should match the radian of the outer peripheral surface of the roller to improve the contact rate between the roller and the raceway, increase the contact ellipse area, reduce the contact stress, and improve the bearing fatigue life.

In order to improve the axial and radial eccentric load capacity of the bearing, in the spherical roller bearing provided by the present invention, the axial lengths of the two rows of rollers are set to different lengths, so that the two rows of rollers respectively form long rollers 310 (length is L1 in FIG. 2 ) and the short roller 320 (the length is L2 in FIG. 2 ), and make the maximum diameter of the short roller 320 (Dw1 in FIG. 2 ) smaller than the maximum diameter of the long roller 310 (Dw2 in FIG. 2 ), and also Further, the ball center of the spherical surface where the outer raceway is located is deviated from the axial center of the bearing along the axial direction of the bearing, and one end of the short roller 320 is offset from the axial center of the bearing. .

After the length of the long roller 310 is increased, the contact area between the long roller 310 and the raceway can be increased, the stress on the side of the long roller 310 can be reduced, and the ability of one end of the long roller 310 to bear the axial load can be improved.

Moreover, the ball center of the spherical surface on which the outer raceway is located deviates from the bearing center along the axial direction of the bearing toward one end of the short roller 320, (1) the radial average thickness of the outer ring 100 at one end of the long roller 310 is increased, and the outer ring at this end is increased. 100 strength, further increase the ability of one end of the long roller 310 to bear axial eccentric load; (2) make the diameter of the outer ring 100 at the end of the long roller 310 smaller, increase the inner ring 200, the cage and the roller from the outer ring The difficulty of the 100 in the detachment enables the bearing to withstand the large angle deflection of the inner ring 200, the cage and the roller relative to the outer ring 100 caused by the large radial eccentric load, and the deflection angle can be increased to more than 6°; (3) The inner diameter D2 of the outer ring 100 at the end of the short roller 320 is increased, so that the difference between the outer diameter Db of the cage and the inner diameter D2 of the outer ring 100 at the end of the short roller 320 is less than 3mm. At the same time, the cage is made of nylon. The cage has good elasticity and is easy to compress Installed into the outer ring 100 , so that the outer ring 100 can adopt an integrated structure and improve the mechanical strength of the outer ring 100 .

However, in the existing spherical roller bearing shown in Figure 1, in order to bear the radial eccentric load, the length of one side of the roller must be increased, so the axial width of the outer ring 1 and the inner ring 2 is increased, resulting in increased rolling The inner diameter of the outer ring 1 of the sub-end is reduced, the outer diameter Db of the cage is larger than the inner diameter D1 of the outer ring 1 of the extended roller end, and usually the difference between the outer diameter Db of the cage and the diameter D1 of the outer raceway opening is less than 5mm, and the cage is made of steel The stamping cage cannot be compressed, so the outer ring 1 can only adopt a split structure to facilitate the installation of the cage.

Further, in the spherical roller bearing provided by the present application, the maximum diameter of the short roller 320 is smaller than the maximum diameter of the long roller 310, so that the radial thickness of the inner ring 200 at the small roller end can be increased, compensating for the outer ring 100. The influence of the spherical surface on which the outer raceway is located deviates from the bearing center on the bearing size, so that the wall thicknesses of the inner ring 200 and the outer ring 100 at both ends of the bearing are balanced to ensure the overall mechanical strength of the bearing. Specifically, the ratio of the length of the long roller 310 to the length of the short roller 320 is (1.5-2.5): 1, preferably (1.0-2.0): 1; the ratio of the length of the long roller 310 to the axial length of the inner ring 200 is ( 0.4-0.6): 1, preferably 0.5: 1; the ratio of the diameter of the long roller 310 to the diameter of the short roller 320 is (1-1.5): 1, preferably (1.2-1.3): 1; the ball on the spherical surface where the outer raceway is located The ratio of the offset distance D between the center of the bearing and the center of the bearing and the axial width of the outer ring is (0.05-0.2):1, preferably (0.1-0.15):1, which can make the size and eccentric load capacity of the bearing reach an appropriate value.

During the working process of the bearing, the rollers tend to move toward the middle under the action of centrifugal force. Therefore, the spherical roller bearing provided by the present application is provided with a middle retaining ring 400 between the long roller 310 and the short roller 320. The postures of the rollers 310 and the short rollers 320 are guided to prevent the rollers from being deflected, and share the axial force of the rollers to improve the axial bearing capacity. Specifically, the middle retaining ring 400 is disposed between the two inner raceways and is located on the inner side of the cage in the circumferential direction.

Further, as shown in FIG. 2 , in one embodiment, in the spherical roller bearing provided by the present invention, the middle retaining ring is a fixed middle retaining ring, and the longitudinal section of the middle retaining ring 400 is similar to an isosceles trapezoid shape, The two sides of the isosceles trapezoid are symmetrically inclined, and the short side of the isosceles trapezoid is fixedly connected to the inner ring 200 and is usually integrally formed, so that the middle retaining ring 400 and the retaining surface of the two rows of rollers form a conical surface with the same taper. Moreover, both sides of the isosceles trapezoid are parallel to the cross-sections of the two rows of rollers, respectively.

As shown in FIG. 3 , in another embodiment, the middle retaining ring 400 is a floating middle retaining ring, and the floating middle retaining ring is arranged between the cage and the inner ring, which can further increase the length of the rollers and omit the inner ring and the inner ring. The overtravel groove between the middle retaining rings simplifies and reduces the outer diameter of the inner ring. The longitudinal section of the middle retaining ring is in the shape of a trapezoid, and the angle between the trapezoidal side waist on the long roller 310 side and the axial center line of the bearing is less than or equal to the angle between the trapezoidal side waist on the short roller 320 side and the axial center line of the bearing. Horn. When applied to a concrete mixer truck, it is preferable that the angle between the trapezoidal side waist on the side of the long roller 310 and the axial centerline of the bearing is smaller than the angle between the trapezoidal side waist on the short roller 320 side and the axial centerline of the bearing. Improve bearing capacity.

Specifically, the cage includes a long-roller cage 311 and a short-roller cage 321, which are respectively provided with pockets for accommodating the long-roller and short-roller, and the inner ends of the long-roller cage 311 and the short-roller cage 321 Abutting on the middle retaining ring 400 respectively, the long roller cage 311 and the short roller cage 321 cooperate with the middle retaining ring 400, and the two end faces and outer diameters of the long roller 310 and the short roller 320 are carried out. Good restraint to prevent roller deflection.

Specifically, as shown in FIG. 2, when the middle retaining ring is a fixed middle retaining ring, the inner ends of the long roller cage 311 and the short roller cage 321 overlap the outer peripheral surface of the middle retaining ring 400; as shown in FIG. 3 As shown, when the middle retaining ring is a floating middle retaining ring, inner shoulders are provided on the inner peripheral surfaces of the inner ends of the long roller cage 311 and the short roller cage 321, and are overlapped on the middle retaining ring 400 through the inner shoulders.

Further, the spherical roller bearing provided by the present invention does not need to be provided with flanges on the inner ring 200, which ensures the length of the long rollers 310 and improves the utilization rate of the bearing size. In addition, in the spherical roller bearing provided by the present application, the long roller cage 311 and the short roller cage 321 are made of nylon material, which is convenient for assembly.

Further, as shown in FIG. 4 , in the spherical roller bearing provided by the present invention, the end face edge of the long roller 310 in contact with the fixed middle retaining ring and the end face edge of the short roller 320 in contact with the fixed middle retaining ring are both. The ball base surface is S, which reduces the resistance of the rolling contact between the roller and the fixed middle retaining ring, reduces the friction between the roller end face and the middle retaining ring (PV value is reduced by 30%), and the ball base surface of the roller is in contact with the middle retaining ring. The middle of the ring ensures good stress distribution and improves the performance of the bearing.

In a preferred embodiment, in the spherical roller bearing provided by the present application, the axial width of the inner ring 200 is smaller than the width of the outer ring 100, so that the inner diameter of the end face of the outer ring 100 is reduced, preventing the inner ring 200 from passing from the outer ring 100, the mutual deflection angle between the inner ring 200 and the outer ring 100 is increased, so that the deflection angle of the inner ring 200 is increased to more than 6°; and the roller assembly will not protrude from the end face of the outer ring 100, avoiding the roller assembly. floating or interfering with parts around the bearing.

When in use, the inner ring 200 is interference fit with the output shaft of the main drive gearbox of the equipment, the outer ring 100 is clearance fit with the gear box seat hole, and the large diameter long roller 310 end of the bearing faces the equipment and mainly bears radial and axial loads. It is installed on one side of the gear box to bear the main radial and axial loads; the 320 end of the small diameter short roller is installed towards the side of the gearbox, which only plays the role of support and adjustment.

In the spherical roller bearing provided by the present invention, the contact angle θ1 of the long roller 310 is greater than or equal to the contact angle θ2 of the short roller 320 . In the spherical roller bearing provided by the application of the present invention, because the end face of the outer ring of the long roller end is wider, and the thickness around the opening of the outer ring is too thin, if the bearing encounters the thinner end face of the outer ring here, it is easy to install the bearing. In order to solve this problem, in a preferred embodiment, the end face of the outer ring 100 at one end of the long roller 310 is provided with an annular recess 110 surrounding the inner hole of the outer ring 100 to avoid damage to the end face and raceway of the outer ring. Contact with the end face of the fixed bearing, resulting in end face damage and rupture.

As shown in Figure 5, the assembly process of the spherical roller bearing provided by the present invention is as follows:

(1) Use a pneumatic press to shrink and deform the outer diameter of the long roller cage 311 into the outer ring 100 through the die, and pay attention to make the end with the small outer diameter of the long roller cage 311 facing the end with the small inner diameter of the outer ring 100 ( Install long roller 310 side);

(2) Insert the end of the inner ring 200 with the smaller outer diameter (the side where the long roller 310 is installed) into the outer ring 100 toward the end with the smaller inner diameter of the outer ring 100, and make the end of the long roller cage 311 with the larger outer diameter attached to the outer ring 100. 400 surface of the middle retaining ring;

(3) Use a pneumatic press to compress and deform the outer diameter of the short roller cage 321 between the outer ring 100 and the inner ring 200 through the die, and make the end of the short roller cage 321 with the larger outer diameter stick to the middle retaining ring 400 surfaces;

(4) Rotate the inner ring 200 and the cage assembly to be perpendicular to the outer ring 100, install the long roller 310 and the short roller 320 into the corresponding pockets in the cage respectively, and rotate the inner ring 200 after they are all installed The roller assembly enters the outer ring 100 .

On the other hand, the present invention also provides the above-mentioned heat treatment process for the spherical roller bearing suitable for axial and radial eccentric load conditions, including quenching and tempering processes. In one specific embodiment, the specific process of quenching for:

Preheat the processed bearing parts (outer ring 100, inner ring 200, rollers made of Cr4M04V steel) at 840°C, then increase the quenching heating temperature to 1100°C, keep warm for 5-10 minutes and then cool down to promote the alloy The carbide dissolves, increases the alloying concentration of supercooled austenite, and ensures high hardness after quenching. The quenching method is salt bath quenching, which can avoid high-temperature oxidation corrosion, distortion and quenching cracks. Tempering specifically adopts 3 times of high temperature tempering, the tempering temperature is 240 ° C, and each time is kept for 2 hours, so as to obtain sufficient tempering and stabilize the structure and size.

After testing, the spherical roller bearing prepared by the process of the present invention still has high hardness under high temperature, stable size, high wear resistance, and prolonged bearing fatigue life.

Further, in order to verify the excellent performance of the self-aligning roller bearing of the present invention, the present invention sets up examples and comparative examples to conduct a running performance simulation test, specifically simulating the working condition of the self-aligning bearing applied to a concrete mixer truck. As shown in FIG. 6 , the spherical roller bearing is installed at the output end of the main transmission gear box of the tank body 500 to support the tank body 500 , and the direction of the arrow is the traveling direction of the mixer truck. The inner ring of the spherical roller bearing rotates, the short roller end is facing the side of the tank body of the cement mixer, and the long roller end is facing the side of the gearbox. to the load.

The embodiment is the spherical roller bearing of the present invention, and the specific structure is shown in FIG. 2 ; the comparative example is the traditional spherical roller bearing, and the specific structure is shown in FIG. 1 . The specific parameters of the spherical roller bearings in the examples and comparative examples are shown in Table 1.

Table 1 Parameters of spherical roller bearings in the examples and comparative examples

轴承参数Bearing parameters	实施例Example	对比例Comparative ratio
内圈左端面内径(mm)Inner diameter of left end face of inner ring (mm)	110110	110110
内圈右端面内径(mm)Inner diameter of right end face of inner ring (mm)	110110	110110
外圈左端面内径(mm)Inner diameter of left end face of outer ring (mm)	136136	148.9148.9
外圈右端面内径(mm)Inner diameter of right end face of outer ring (mm)	158.3158.3	148.9148.9
内圈轴向宽度(mm)Axial width of inner ring(mm)	6969	6969
外圈轴向宽度(mm)Axial width of outer ring(mm)	8282	8282
左列滚子和右列滚子各自数量(个)Number of rollers in left row and right row rollers (pieces)	22twenty two	22twenty two
左列滚子长度(mm)Left row roller length (mm)	3333	30.830.8
右列滚子长度(mm)Right row roller length (mm)	1717	30.830.8
左列滚子最大直径(mm)Left row roller maximum diameter (mm)	18.418.4	18.418.4
右列滚子最大直径(mm)Maximum diameter of right row roller (mm)	16.516.5	18.418.4

Figure 7 shows the simulated concrete mixer under normal driving, acceleration, deceleration, and sudden braking conditions, when the same load (combined load of axial load and radial load) is applied to the spherical roller bearing of the embodiment and the comparative example The maximum stress distribution of the roller, Figure 8 shows the contact stress distribution between the inner ring and the outer ring at different length positions of the roller.

The angles in the circumferential direction in Fig. 7 represent the positions of the 22 left-row rollers and the 22 right-row rollers in the spherical roller bearing (the left and right columns correspond to the left and right columns in Fig. 1 and Fig. 2, respectively) , the 0° position corresponds to the roller at the bottom of the spherical roller bearing, and the scale in the radial direction represents the stress on the roller. It can be seen from the graphs in Fig. 6 that under normal driving, acceleration, deceleration and sudden braking conditions, (1) the stress (A1) on the rollers in the left column in the embodiment is smaller than that on the rollers in the left column in the comparative example ( B1), (2) Under normal driving conditions, the rollers of the right row in the comparative example are completely unloaded, and the rollers of the right row (A2) in the embodiment can share a part of the stress, (3) When subjected to a certain axial direction on the opposite side Under the acceleration condition of the force, the rollers in the right row in the embodiment and the comparative example share a part of the stress, but the stress on the rollers in the right row (A2) in the embodiment is greater than that in the rollers in the right row (B2) in the comparative example, which illustrates the present invention Spherical roller bearings have a strong ability to withstand axial forces on the opposite side. It can be seen that after the improved structure of the self-aligning roller bearing of the present invention, the difference between the stresses on the left row rollers and the right row rollers is reduced, the balance of the forces on the two rows of rollers is improved, and the acceleration conditions are all working conditions. In the case of the most uniform bearing force.

In Fig. 8, the abscissa represents the longitudinal position of the roller, and the ordinate represents the contact stress between the roller and the inner ring and outer ring at the corresponding position.

It can be seen from the graphs in Figure 8 that under normal driving, the average stress P1 between the rollers in the left row and the outer ring of the comparative example is not high, but since the rollers in the right row do not participate in load sharing, all the forces are concentrated on the left row rollers, so the entire length of the rollers is brought into contact with the roller raceways. Second, stress concentration spikes appear on the left side of the rollers in the left column, causing early fatigue spalling of the raceways. The embodiment effectively avoids stress concentration, and both the left and right rows of rollers participate in the load-bearing, which makes the bearing operation more stable; again, the rollers of the embodiment have not come into contact over the entire length of the rollers, so the load-bearing capacity is still certain. surplus.

Under the acceleration condition, the emphasis is on the load-bearing of the rollers in the right row. Although the length of the rollers in the right row of the embodiment is short, the stress value is not high, and it is still in a fairly safe range.

In deceleration, especially under the condition of sudden braking, the embodiment effectively controls the maximum stress peak value when the single-row load is unavoidable, with obvious advantages, and greatly improves the safety factor and service life of the bearing.

It can be seen that after the structure of the self-aligning roller bearing of the present invention is improved, the contact stress distribution between the roller and the inner ring and the outer ring raceway is improved, and the premature fatigue failure of the bearing due to stress concentration is avoided.

Further, the present invention obtains through simulation analysis and calculation that the self-aligning roller bearing of the present invention has a deflection angle greater than 6°, the radial or axial load on both sides differs by more than 5 times, and the roller end on the main force side bears the radial and axial loads. The load capacity is increased by more than 45%, and the bearing life is increased by more than 3 times; or under the same load, the inner diameter, outer diameter and roller diameter of the bearing are reduced by ≥10%, and the weight is reduced by ≥30%. Shaft and seat hole sizes are reduced accordingly.

In the description of the present invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", The orientation or positional relationship indicated by "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, only It is to facilitate the description of the present invention and to simplify the description, rather than indicating or implying that the device or element referred to must have a particular orientation, be constructed and operate in a particular orientation, and therefore should not be construed as limiting the invention.

In the present invention, unless otherwise expressly specified and limited, the terms "installed", "connected", "connected", "fixed" and other terms should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection , or integrated; it can be a mechanical connection, an electrical connection, or a communication; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of the two elements or the interaction between the two elements. . For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

The above specific embodiments are not intended to limit the protection scope of the present invention. For those skilled in the art, any alternative improvements or transformations made to the embodiments of the present invention fall within the protection scope of the present invention.

The parts that are not described in detail in the present invention are the known technologies of those skilled in the art.

Claims

A spherical roller bearing suitable for axial and radial eccentric load conditions, characterized in that it includes:

an outer ring, the inner peripheral surface of the outer ring is formed with a spherical outer raceway;

an inner ring, two inner raceways are formed on the outer peripheral surface of the inner ring;

Two rows of symmetrical spherical rollers are held between the two inner raceways and the shared outer raceway by a cage, and the lengths of the two rows of rollers are different so that the two rows of rollers constitute long rollers and short rollers respectively , the maximum diameter of the short roller is smaller than the maximum diameter of the long roller;

and a middle retaining ring arranged between the long roller and the short roller;

The ball center of the spherical surface on which the outer raceway is located is deviated from the axial center of the bearing toward one end of the short roller along the axial direction of the bearing.
The spherical roller bearing suitable for axial and radial eccentric load conditions according to claim 1, characterized in that, the middle retaining ring is arranged between the two inner raceways, and is located on the side of the cage. Circumferentially inside.
The spherical roller bearing suitable for axial and radial eccentric load conditions according to claim 2, wherein the middle retaining ring is a fixed middle retaining ring, and the longitudinal section of the middle retaining ring is similar to isosceles Or non-isosceles trapezoid shape, the short side of the trapezoid is fixedly connected with the outer peripheral surface of the inner ring, and the sides of the trapezoid are symmetrical or asymmetrically inclined.
The spherical roller bearing suitable for axial and radial eccentric load conditions according to claim 2, wherein the middle retaining ring is a floating middle retaining ring, and the longitudinal section of the middle retaining ring is trapezoidal shape, The angle between the trapezoidal side waist on one side of the long roller and the axial centerline of the bearing is less than or equal to the angle between the trapezoidal side waist on the short roller side and the axial centerline of the bearing.
The spherical roller bearing suitable for axial and radial eccentric load conditions according to claim 1, characterized in that the end face edge of the long roller in contact with the middle retaining ring, and the short roller and the middle retaining ring The edges of the end faces that the ring contacts are all spherical base surfaces.
The spherical roller bearing suitable for axial and radial eccentric load conditions according to claim 1, wherein the cage comprises a long roller cage and a short roller cage, and the long roller retains the The inner ends of the frame and the short roller cage are respectively abutted on the middle retaining ring.
The spherical roller bearing suitable for axial and radial eccentric load conditions according to claim 1, wherein the contact angle of the long roller is greater than or equal to the contact angle of the short roller.
The spherical roller bearing suitable for axial and radial eccentric load conditions according to claim 1, wherein the axial width of the inner ring is smaller than the width of the outer ring.
The spherical roller bearing suitable for axial and radial eccentric load conditions according to claim 1, characterized in that, an annular recess surrounding the inner hole of the outer ring is provided on the end surface of the outer ring at one end of the long roller.
The heat treatment process of the spherical roller bearing suitable for axial and radial eccentric load conditions according to any one of claims 1-9, characterized in that it comprises the following steps:

(1) Quenching: Preheat the outer ring, inner ring and roller at 835-845°C, then increase the quenching heating temperature to 1100-1105°C, and use salt bath quenching;

(2) Tempering: multiple high-temperature tempering is used, and the tempering temperature is 235-245 °C.