GB2612486A

GB2612486A - Self-aligning roller bearing of asymmetric structure

Info

Publication number: GB2612486A
Application number: GB2300908.7A
Authority: GB
Inventors: Liang Baozhu; Yan Xiaoming; Chai Zhongdong
Original assignee: Envision Energy Co Ltd
Current assignee: Envision Energy Co Ltd
Priority date: 2020-09-08
Filing date: 2020-09-08
Publication date: 2023-05-03
Also published as: MX2023001698A; GB202300908D0; CN114502851A; WO2022051878A1

Abstract

A self-aligning roller bearing of an asymmetric structure, comprising an outer ring (101), an inner ring (102), rolling bodies (103), a retainer (104), and a spacer ring (105) designed in a narrow floating fashion. The rolling bodies (103) are arranged in two columns and provided between the inner ring (102) and the outer ring (101); respective contact angles of the rolling bodies are different; meanwhile, corresponding inner raceway surfaces (1021, 1022) and an outer raceway surface (1011) are also of an asymmetric structure.

Description

SELF-ALIGNING ROLLER BEARING OF ASYMMETRIC STRUCTURE

TECHNICAL FIELD

The present invention relates to the technical field of wind power, in particular to a self-aligning roller bearing of an asymmetric structure

BACKGROUND

In recent years, countries around the world have begun to attach great importance to green energy, and wind power generation technology has rapidly developed gradually towards large scale and commercialization Wind turbine nacelles are usually mounted on 40-60 m high towers, with greater changes in temperature and humidity and complex load conditions. Therefore, high requirements are put forward for rolling bearings mounted at various parts. Bearings in a wind turbine set include yaw system bearings, variable pitch system bearings, and drive system bearings. The drive system bearings include a main shaft bearing, a gearbox bearing, and a generator bearing.

A main shaft of a wind turbine transmits a torque from an impeller to other parts of a drive system, which will cause larger bending deformation during operation The main shaft is supported by the main shaft bearing, so that both an action force and deformation on the main shaft affect the main shaft bearing. The main shaft bearing mainly bears a radial force and also bears an axial force generated partially by a wind force, so that the force bearing condition is complex. Due to the influence of the force bearing condition and shaft deformation, the main shaft bearing of the wind turbine must have good self-aligning performance. Therefore, a self-aligning roller bearing is usually used as the main shaft bearing of the wind turbine.

However, in practical applications, when the axial force is larger, rolling bodies of a typical self-aligning roller bearing of a fixed rib structure have serious unbalanced loading, which will cause early raceway wear, while a spacer ring of a typical self-aligning roller bearing of a floating spacer ring structure is seriously worn, which is easy to cause early bearing failure.

SUMMARY

In view of part or all of the problems in the prior art, the present invention provides a self-aligning roller bearing of an asymmetric structure, including: an outer ring having an outer raceway surface on an inner peripheral side for supporting rolling bodies; an inner ring having inner raceway surfaces on an outer peripheral side for supporting the rolling bodies, where the inner raceway surfaces and the outer raceway surface have a specific curvature difference; and the rolling bodies including a plurality of first rollers arranged on a first side of the self-aligning roller bearing and a plurality of second rollers arranged on a second side of the self-aligning roller bearing that is opposite to the first side, where the plurality of first rollers and the plurality of second rollers are arranged between the outer raceway surface and the inner raceway surfaces and are configured to be rollable, so that the outer ring and the inner ring are capable of rotating relative to each other; and a first angle between a load action line of the plurality of first rollers and a radial plane of the self-aligning roller bearing is different from a second angle between a load action line of the plurality of second rollers and the radial plane of the self-aligning roller bearing.

Further, the outer raceway surface includes a concave curved surface, and the rolling bodies are configured to match in shape with the concave curved surface; and/or the inner raceway surfaces include two columns of concave curved surfaces, and the rolling bodies are configured to match in shape with the concave curved surfaces.

Further, the curvature difference between the inner raceway surfaces and the outer raceway surface is between 0.1% and 1.5%.

Further, the self-aligning roller bearing includes a retainer arranged between the inner ring and the outer ring. The retainer is of a two-piece type, and includes N grooves for accommodating the rolling bodies. The grooves are configured to separate the rolling bodies along a circumferential direction according to each column Further, the self-aligning roller bearing includes a spacer ring designed in a narrow fashion and arranged between the retainer and the inner ring. An inner circumference of the spacer ring can contact with the inner raceway surfaces, and an outer circumference of the spacer ring can contact with an inner circumference of the retainer.

Further, a difference between the first angle and the second angle is at least 20%.

In the present invention, the load action line passes through a contact point between the roller and the outer raceway surface and a contact point between the roller and the corresponding inner raceway surface on one side.

Further, the outer raceway surface is of an asymmetric structure.

Further, the inner raceway surfaces are of an asymmetric structure.

Further, there is a gap between the inner circumference of the spacer ring and the inner raceway surfaces, and there is a gap between the outer circumference of the spacer ring and the inner circumference of the retainer.

Further, there is a gap between a side surface of the spacer ring and an end surface of the roller.

According to the self-aligning roller bearing of the asymmetric structure provided by the present invention, the two columns of rolling bodies have different contact angles, where the rolling bodies on one side have a larger contact angle, and the spacer ring is designed in a floating fashion. On one hand, the bearing capacity of an axial force of the bearing is improved, and on the other hand, due to design of different fitness of the inner and outer rings, the rolling bodies can be effectively guided in combination with the structure of the spacer ring to control the rollers to swing, which avoids side wear of the spacer ring under an axial load. Meanwhile, the structure of the floating spacer ring also effectively avoids unbalanced loading of raceways of the rollers under the axial load. It is verified that under a fan load, when Fa / Fr > 0.2, especially when 0.25 < Fa / Fr < 0.5, the self-aligning roller bearing of the asymmetric structure provided by the present invention has significantly reduced wear level and improved stability compared to other bearings.

BRIEF DESCRIPTION OF THE DRAWINGS

To further illustrate the above and other advantages and features of the embodiments of the present invention, more specific descriptions of the embodiments of the present invention will be presented with reference to the accompanying drawings. It may be understood that these accompanying drawings only depict typical embodiments of the present invention, and therefore will not be considered as a limitation to its scope. In the accompanying drawings, for the sake of clarity, the same or corresponding components will be denoted with the same or similar signs.

FIG. 1 shows a sectional view of a self-aligning roller bearing of an asymmetric structure according to one embodiment of the present invention; and FIG. 2 shows a schematic roller arrangement diagram of a self-aligning roller bearing of an asymmetric structure according to one embodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In the description below, the present invention is described with reference to the embodiments. However, those skilled in the art will recognize that the embodiments may be implemented without one or more specific details or in conjunction with other alternative and/or additional methods, materials, or components. In other cases, well-known structures, materials, or operations are not shown or described in detail so as not to obscure the inventive point of the present invention. Similarly, specific quantities, materials, and configurations are described for explanatory purposes in order to provide a comprehensive understanding of the embodiments of the present invention. However, the present invention is not limited to these specific details. In addition, it should be understood that the embodiments shown in the accompanying drawings are illustrative representations and are not necessarily drawn to correct scale.

In this specification, reference to "one embodiment" or "the embodiment" means that specific features, structures, or characteristics described in combination with the embodiment are included in at least one embodiment of the present invention. The phrase "in one embodiment" appearing throughout this specification does not necessarily refer to the same embodiment.

It should be noted that the embodiment of the present invention describes the process steps in a specific order, but this is only for the purpose of describing the specific embodiment, rather than defining the sequence of the steps. On the contrary, in different embodiments of the present invention, the sequence of the steps may be adjusted according to the adjustment of the process.

In view of the problems of unbalanced loading of rollers and serious wear of a spacer ring when an axial force of a wind turbine is larger, the present invention provides a self-aligning roller bearing of an asymmetric structure. A swing angle of the rollers is controlled in a guide manner through design of different fitness of raceways for inner and outer rings. The technical solution of the present invention is further described below in combination with the accompanying drawings of the embodiment FIG. 1 shows a sectional view of a self-aligning roller bearing of an asymmetric structure according to one embodiment of the present invention. As shown in FIG. 1, a self-aligning roller bearing of an asymmetric structure includes an outer ring 101, an inner ring 102, rolling bodies 103, a retainer 104, and a spacer ring 105.

An inner circumference of the outer ring 101 is an outer raceway surface for supporting the rolling bodies 103. In one embodiment of the present invention, the outer raceway surface 1011 includes a concave curved surface, and the rolling bodies 103 match in shape with the concave curved surface. In another embodiment of the present invention, the outer raceway surface 1011 of the outer ring 101 is of an asymmetric structure.

The inner ring 102 can rotate relative to the outer ring 101. An outer circumference of the inner ring 102 is inner raceway surfaces 1021 and 1022. The inner raceway surfaces 1021 and 1022 are configured to support the rolling bodies 103. In one embodiment of the present invention, the inner raceway surfaces 1021 and 1022 include concave curved surfaces, and the rolling bodies 103 match in shape with the concave curved surfaces. The concave curved surfaces of the inner raceway surfaces 1021 and 1022 have different curvatures, and there is a specific curvature difference between the inner raceway surface and the outer raceway surface. In one embodiment of the present invention, the curvature difference between the inner raceway surface and the outer raceway surface is between 0.1% and 1.5%.

The rolling body 103 includes N rollers 1031, which are arranged in two columns along a circumferential direction and provided between the outer raceway surface 1011 and the inner raceway surface 1021 or 1022, where N is a natural number. The rollers 1031 can roll on the outer raceway surface 1011 and the inner raceway surface 1021 or 1022. As shown in FIG. 1, the two columns of rollers of the rolling body have different contact angles, where the rollers on one side have a larger contact angle and may bear a larger axial force. For example, a difference between the contact angles of the two columns of rollers preferably at least ranges from 20% to 80%, such as 20%, 25%, 30%, 40%, or 80%. The inventor found through research that when the difference between the contact angles is more than 20%, an axial load of the wind turbine may be better borne, and the rolling bodies do not easily slide in the direction of a rotating surface of the bearing. The larger the difference between the contact angles is, the better the axial load capacity is. The design of different contact angles of the two columns of rollers is combined with different curvatures of the corresponding outer raceway surface 1011 and inner raceway surfaces 1021 and 1022, so that the raceways for the inner and outer rings on the two sides have different fitness, which may control a swing angle of the roller 1031 in a guide manner to keep within a specific range, thereby effectively avoiding wear. In the present invention, the contact angle refers to an angle between a load action line 001 of the roller 1031 and a radial plane 002 of the self-aligning roller bearing, the load action line 001 passes through a contact point between the roller 1031 and the outer raceway surface 1011 and a contact point between the roller 1031 and the corresponding inner raceway surface 1021 or 1022 on one side. In actual work, when the bearing rotates, the roller 1031 sometimes rotates a small angle about the load action line 001, where the small angle is the swing angle. In one embodiment of the present invention, the roller 1031 is of a drum type. In another embodiment of the present invention, the self-aligning roller bearing of the asymmetric structure is a main shaft bearing for a wind turbine; a first side of the bearing is a side close to the wind turbine, and a second side of the bearing is a side away from the wind turbine; a contact angle of the first side ranges from 7° to 13°, and a contact angle of the second side ranges from 110 to 17'; and the contact angle of the second side is at least 20% larger than the contact angle of the first side, so that the axial load capacity of the second side is better, and the wind load with a large proportion of axial force may be adapted.

The retainer 104 is arranged between the inner ring 102 and the outer ring 101. As shown in FIG. 2, the retainer 104 is of a two-piece type, is annular as a whole, and is provided with transverse plates 1041 arranged at equal intervals in the circumferential direction on two sides. The two adjacent transverse plates 1041 constitutes a groove 1042, and the groove 1042 is configured to accommodate the roller 1031. One roller 1031 is accommodated in each groove 1042. The retainer 104 further limits the swing angle.

The spacer ring 105 is arranged between the retainer 104 and the inner ring 102, is annular as a whole, and is designed in a narrow fashion. An inner circumference of the spacer ring 105 can contact with the inner raceway surfaces, and an outer circumference of the spacer ring can contact with an inner circumference of the retainer. In one embodiment of the present invention, to avoid unbalanced loading of the raceways for the rollers, the spacer ring 105 is designed in a floating fashion, that is, there is a specific gap between the inner circumference of the spacer ring 105 and the inner raceway surface, and there is also a specific gap between the outer circumference of the spacer ring and the inner circumference of the retainer, so that the spacer ring 105 can move a little in a radial direction. In one embodiment of the present invention, to further reduce the wear of the side surface of the spacer ring 105, the spacer ring 105 is designed in a narrower fashion, so that under the axial load, a specific gap is still reserved between the end surface of the roller and the side surface of the spacer ring. In one embodiment of the present invention, the gap between the end surface of the roller and the side surface of the spacer ring ranges from 0.5 mm to 3.5 mm.

In one embodiment of the present invention, the outer ring 101, the inner ring 102, and the rollers 1031 are made of bearing steel, the spacer ring 105 is made of cast iron or other metal material, and the retainer 104 is made of brass or other metal material.

Although the embodiments of the present invention have been described above, it should be understood that they are presented only as examples and not as limitations. Apparently, those skilled in the relevant field may make various combinations, modifications, and changes without departing from the spirit and scope of the present invention. Therefore, the width and scope of the present invention disclosed herein should not be limited by the exemplary embodiment disclosed above, and should be defined only according to the appended claims and their equivalent substitutions.

Claims

WHAT IS CLAIMED IS: 1. A self-aligning roller bearing of an asymmetric structure, comprising: an outer ring having an outer raceway surface on an inner peripheral side for supporting rolling bodies; an inner ring having inner raceway surfaces on an outer peripheral side for supporting the rolling bodies; a retainer arranged between the inner ring and the outer ring; a spacer ring arranged between the retainer and the inner ring; and the rolling bodies; wherein the spacer ring is designed in a narrow fashion, and there is a specific gap between a side surface of the spacer ring and an end surface of the roller; the inner raceway surfaces and the outer raceway surface have a specific curvature difference; and the rolling bodies comprise a plurality of first rollers arranged on a first side of the self-aligning roller bearing and a plurality of second rollers arranged on a second side of the self-aligning roller bearing that is opposite to the first side, wherein the plurality of first rollers and the plurality of second rollers are arranged between the outer raceway surface and the inner raceway surfaces and are configured to be rollable, so that the outer ring and the inner ring are capable of rotating relative to each other; and a first angle between a load action line of the plurality of first rollers and a radial plane of the self-aligning roller bearing is different from a second angle between a load action line of the plurality of second rollers and the radial plane of the self-aligning roller bearing.
2. The self-aligning roller bearing according to claim 1, wherein the outer raceway surface comprises a concave curved surface, and the rolling bodies are configured to match in shape with the concave curved surface; and/or the inner raceway surfaces comprise two columns of concave curved surfaces, and the rolling bodies are configured to match in shape with the concave curved surfaces
3 The self-aligning roller bearing according to claim 1, wherein the inner raceway surfaces and the outer raceway surface are of an asymmetric structure, and the curvature difference between the inner raceway surfaces and the outer raceway surface is between 0.1% and 1.5%.
4. The self-aligning roller bearing according to claim 1, wherein the retainer is of a two-piece type, and comprises grooves for accommodating the rollers.
5. The self-aligning roller bearing according to claim I, wherein the gap between the side surface of the spacer ring and the end surface of the roller ranges from 0.5 mm to 3.5 mm.
6. The self-aligning roller bearing according to claim 1, wherein an inner circumference of the spacer ring is configured to be capable of contacting with the inner raceway surfaces, and an outer circumference of the spacer ring is configured to be capable of contacting with an inner circumference of the retainer.
7. The self-aligning roller bearing according to claim 6, wherein there is a gap between the inner circumference of the spacer ring and the inner raceway surfaces, and there is a gap between the outer circumference of the spacer ring and the inner circumference of the retainer.
8. The self-aligning roller bearing according to claim 1, wherein a difference between the first angle and the second angle ranges from 20% to 80%.
9. The self-aligning roller bearing according to claim I, wherein the self-aligning roller bearing of the asymmetric structure is a main shaft bearing for a wind turbine, wherein the first side is a side close to a wind rotor, and the second side is a side away from the wind rotor; and the first angle ranges from 7° to 13°, the second angle ranges from 110 to 17°, and the second angle is at least 20% larger than the first angle.The self-aligning roller bearing according to any one of claims 1 to 9, wherein the outer ring, the inner ring, and the roller are made of bearing steel, and/or the spacer ring is made of cast iron, and/or the retainer is made of brass