Cylindrical roller bearing for a wind turbine gearbox and wind turbine gearbox

Abstract

Provided are a cylindrical roller bearing for a wind power gear box and a wind power gear box. The cylindrical roller bearing for a wind power gear box comprises at least one ring, a cage and a plurality of rollers held by the cage. The outer periphery of the ring is provided with at least two rows of raceways, and each row of raceways is provided with one or more rows of the rollers. The diameter of the rollers is 25-50 mm, and the ratio of the axial length of the rollers to the diameter is 3.2-11. In the axial direction of the cylindrical roller bearing, the cage is provided with two or more rows of pockets, each row of pockets comprises a plurality of pockets arranged adjacent in the circumferential direction of the cylindrical roller bearing, and at least one pocket in at least one row of pockets is arranged with at least two rollers side by side in the axial and / or circumferential direction.

Description

Technical Field

[0001] This application relates to the field of bearing technology, and particularly to a cylindrical roller bearing for a wind turbine gearbox and a wind turbine gearbox. Background Technology

[0002] Achieving price parity between wind power and thermal power, and reducing the levelized cost of energy (LCoE), remains a major pressure facing the wind power industry. The torque density of wind turbine gearboxes directly impacts LCoE; therefore, improving the torque density of wind turbine gearboxes is particularly urgent.

[0003] Mainstream wind turbine gearboxes typically consist of two or more stages of planetary gears. Increasing the number of planetary gears improves torque density because a larger number of planetary gears reduces the contact stress level at the individual gear contact surfaces, allowing for a significant reduction in the diameter of the planetary gears and gear rings. This has led to a trend in recent years where wind turbine megawatt ratings have been increasing in size, while wind turbine gearbox designs have been trending towards miniaturization and lightweighting. This design trend has resulted in a significant reduction in gearbox size, while also reducing the space available for bearing installation.

[0004] Under current dimensions, the performance of cylindrical roller bearings (especially the contact stress on the bearing raceways) is already close to the upper limit required by wind turbine gearbox design standards. Further reducing bearing size to accommodate smaller spaces will make it difficult to meet the design standards' requirements for bearing contact stress, and the theoretical calculated life of the bearing will decrease dramatically, failing to meet the life requirements of planetary gear bearings in wind turbine gearboxes. Furthermore, current cylindrical roller bearing designs fail to fully utilize axial space to bear loads, nor do they make the most of radial space. The bearing's effective load-bearing volume occupies only about 75% of the bearing mounting area.

[0005] See Figure 1 In a cylindrical roller bearing for a wind turbine gearbox, a single roller 20 is provided both circumferentially and axially within a single pocket 13 of the cage 10. The number of crossbeams 12 of the cage is equal to the number of circumferential rollers 20.

[0006] An excessively large cross-sectional area of ​​the cage beam will occupy space in the circumferential direction of the bearing; the side beam 11 of the cage 10 will occupy the axial space of the bearing. The circumferential space of the bearing is occupied by the cross-section of the cage beam, which will reduce the number of rollers arranged in the circumferential direction of the bearing; the more the axial space of the bearing is occupied by the side beam of the cage, the shorter the effective axial length of the bearing rollers will be, and the bearing capacity will be reduced accordingly. Utility Model Content

[0007] This application is made in view of the aforementioned state of the prior art. The object of this application is to provide a cylindrical roller bearing for wind turbine gearboxes that can improve load-bearing capacity.

[0008] This application provides a cylindrical roller bearing for a wind turbine gearbox, comprising at least one race, a cage, and a plurality of rollers held by the cage. The outer periphery of the race has at least two rows of raceways, each raceway containing one or more rows of the rollers. The rollers have a diameter of 25 to 50 mm and an axial length-to-diameter ratio of 3.2 to 11. In the axial direction of the cylindrical roller bearing, the cage has two or more rows of pockets, each row of pockets including a plurality of pockets arranged adjacent to each other in the circumferential direction of the cylindrical roller bearing. At least one pocket in at least one row of pockets has at least two rollers arranged side by side in the axial and / or circumferential directions.

[0009] In at least one embodiment, the ratio of the axial length to the diameter of the roller is 3.2 to 5.5.

[0010] In at least one embodiment, at least one row of pockets includes a first pocket and a second pocket, the first pocket and the second pocket being arranged alternately in the circumferential direction, each first pocket accommodating one of the rollers, each second pocket accommodating two or more of the rollers, the two or more rollers being arranged side by side in the axial and / or circumferential directions.

[0011] In at least one embodiment, in each pocket of at least one row of pockets, two or more of the rollers are arranged axially with the axial end faces of adjacent rollers in contact.

[0012] In at least one embodiment, in each pocket of at least one row of pockets, a plurality of rollers are arranged in the circumferential direction, and the outer peripheral surfaces of adjacent circumferential rollers are in contact with each other.

[0013] In at least one embodiment, the rollers have the same axial length, and the axial lengths of each row of pockets may be the same or different.

[0014] In at least one embodiment, the cage is an integral cage comprising two end side beams located at both axial ends and one or more intermediate side beams located between the two end side beams, wherein the axial width of the intermediate side beam is greater than or equal to the axial width of the end side beams and less than twice the axial width of the end side beams.

[0015] In at least one embodiment, the axial length of each row of pockets is equal in the axial direction.

[0016] In at least one embodiment, the cylindrical roller bearing has only one race, which is the inner race.

[0017] Embodiments of this application also provide a wind turbine gearbox, which includes a planetary gear mechanism and a cylindrical roller bearing for a wind turbine gearbox according to this application. The planetary gear mechanism includes a planet carrier and a plurality of planet gears rotatably mounted to the planet carrier via pins. The cylindrical roller bearing is mounted between the pins and the inner bores of the planet gears, and the inner bore walls of the planet gears form the outer raceways of the cylindrical rollers.

[0018] Cylindrical roller bearings have two or more rows of pockets along their axial direction. This reduces the size occupied by the cage side beams, increases the axial length ratio of the rollers, and improves the bearing's load-carrying capacity.

[0019] The diameter and axial length-to-diameter ratio of the cylindrical rollers have been optimized. The smaller diameter of the cylindrical rollers results in a greater number of smaller rollers circumferentially, leading to a higher bearing load capacity, approximately 20% higher than existing cylindrical roller bearings in wind turbine gearboxes. Furthermore, the cylindrical roller bearing of this application has a 25% smaller overall size compared to existing cylindrical roller bearings in wind turbine gearboxes, achieving a bearing installation space size comparable to hydraulic sliding bearings. This makes the cylindrical roller bearing more compact and smaller, resulting in lower linear velocities at the same rotational speed, lower frictional torque during wind turbine gearbox startup and operation, and lower frictional power consumption. Additionally, the weight is reduced compared to traditional cylindrical roller bearings in wind turbine gearboxes, leading to excellent acceleration and deceleration conditions and low impact inertia. The reduced weight lowers production costs, achieving a bearing cost comparable to hydraulic sliding bearings.

[0020] In at least one embodiment, the cylindrical roller bearing is designed without an outer ring, which reduces the radial dimension of the entire cylindrical roller bearing and even the wind turbine gearbox, which is conducive to maximizing the radial space of the wind turbine gearbox.

[0021] In at least one embodiment, since the pocket can accommodate two or more rollers, the circumferential space occupied by the crossbeam can be reduced, the circumferential proportion of the rollers can be increased, and the bearing capacity can be improved. Attached Figure Description

[0022] Figure 1 A schematic diagram of a conventional cylindrical roller bearing cage and rollers mounted to its pockets is shown.

[0023] Figure 2A A perspective view of a cage for a cylindrical roller bearing for a wind turbine gearbox according to one embodiment of this application is shown.

[0024] Figure 2B A side view of a cage for a cylindrical roller bearing for a wind turbine gearbox according to one embodiment of this application is shown.

[0025] Figure 3 A perspective view is shown of a cage and rollers mounted to its pockets for a cylindrical roller bearing for a wind turbine gearbox according to one embodiment of this application.

[0026] Figure 4 A perspective view is shown of a cage and rollers mounted to its pockets for a cylindrical roller bearing for a wind turbine gearbox according to another embodiment of this application.

[0027] Figure 5 A perspective view is shown of a cage and rollers mounted to its pockets for a cylindrical roller bearing for a wind turbine gearbox, according to another embodiment of this application. Detailed Implementation

[0028] Exemplary embodiments of this application are described below with reference to the accompanying drawings. It should be understood that these specific descriptions are for teaching those skilled in the art how to implement this application only, and are not intended to exhaustively describe all possible methods of this application, nor to limit the scope of this application.

[0029] See Figures 2A to 5 Embodiments of this application provide a cylindrical roller bearing (hereinafter, sometimes simply referred to as "cylindrical roller bearing") for a wind turbine gearbox, which may include at least one race (inner or outer race), a cage 10, and a plurality of rollers 20 held by the cage 10.

[0030] The outer circumference of the raceway may be provided with at least two rows of raceways, and each raceway may contain one or more rows of rollers 20 (cylindrical rollers). The diameter of the rollers 20 may be 25 to 50 mm, and the ratio of the axial length of the rollers 20 to their diameter may be 3.2 to 11, that is, the rollers are slender rollers.

[0031] Two or more rows of pockets, such as two or three rows of pockets, are provided along the axial direction A of the cylindrical roller bearing. Each row of pockets may include a plurality of pockets 13 arranged adjacent to each other along the circumferential direction C of the cylindrical roller bearing, and at least one pocket 13 in at least one row of pockets has at least two rollers 20 arranged side by side along the axial and / or circumferential directions.

[0032] This cylindrical roller bearing can be a bearing assembly used in wind turbine gearboxes.

[0033] The raceway can be an inner ring, with raceways and flanges on its outer periphery. The flanges protrude radially from the raceways of the inner ring, and the two flanges are axially spaced to form the raceways. A cage 10 is fitted over the inner ring and has multiple pockets along its circumferential direction. In the axial direction A, one row of rollers 20 is arranged within each row of raceways, or at least two rows of rollers 20 are arranged side-by-side. See one example. Figure 5 Each pocket 13 contains at least two rollers 20 arranged side by side along the axial direction A, and the axial end faces of adjacent rows of rollers 20 can abut against each other.

[0034] In the example of this application, the rolling surface of roller 20 directly rolls into contact with the outer circumferential surface (i.e., raceway) of the inner ring and the inner circumferential surface of the inner hole of the planetary gear of the wind turbine gearbox. The envelope circle diameter is the maximum outer diameter of the cylindrical roller bearing. The traditional outer ring is eliminated, and the radial dimension of the entire cylindrical roller bearing and even the wind turbine gearbox is reduced, which is conducive to the pursuit of the ultimate radial space of the wind turbine gearbox.

[0035] The diameter of the roller 20 in this application is 25~50mm, and the ratio of the axial length to the diameter of the roller 20 (i.e., the length-to-diameter ratio) is 3.2~11.

[0036] The range of the diameter of the roller 20 and the range of the ratio of the axial length to the diameter of the roller 20 in this application result in a small radial footprint of the roller 20, which in turn makes the envelope diameter of the cylindrical roller bearing smaller. Therefore, the cylindrical roller bearing of this application occupies a small radial space overall and has a bearing radial installation space size that is basically equivalent to that of a hydraulic sliding bearing. The inner diameter of the inner hole of the matching planetary gear can be smaller, which greatly reduces the diameter of the planetary gear and allows for the installation of more planetary gears, thereby increasing the torque density of the wind turbine gearbox.

[0037] In addition, the diameter of the roller 20 in this application can be 25~50mm, and the length-to-diameter ratio of the roller 20 is 3.2~11, which reduces the outer diameter of the roller 20. Under the same bearing pitch circle diameter, more rollers 20 can be placed in the circumferential direction, which improves the rigidity of the overall cylindrical roller bearing. More rollers 20 mean more contact area with the raceway of the inner ring and the planetary gear. More contact area can distribute the load and reduce the pressure (also known as contact stress) borne by a single roller 20 and the raceway, thereby improving the static load capacity, overall load-bearing capacity and theoretical calculated life of the bearing to meet the application conditions.

[0038] Preferably, the ratio of the axial length to the diameter of the roller 20 (i.e., the length-to-diameter ratio) is 3.2 to 5.5, which allows the cylindrical roller bearing to ensure high load-bearing performance while also meeting the requirements of lightweighting, miniaturization, and cost control for the special application scenario of wind turbine gearboxes.

[0039] It is understood that this application Figures 2A to 5 The cage 10 in the example shown corresponds to a bearing unit for use, the inner ring of which may have two raceways, each raceway corresponding to a row of pockets in the cage 10. Each raceway may contain one or two rows of rollers 20 (but is not limited to one or two rows of rollers).

[0040] At least one row of pockets may include first pockets 131 and second pockets 132, which are alternately arranged in the circumferential direction C, preferably in a regular alternating manner. It is understood that the alternating arrangement here means that there is one or more second pockets 132 between two or more circumferentially adjacent first pockets 131, and one or more first pockets 131 between two or more circumferentially adjacent second pockets 132. Figure 2A In the example shown, on the circumferential direction C, the first pocket 131 and the second pocket 132 are arranged alternately in the pattern of two first pockets 131, one second pocket 132, two first pockets 131, one second pocket 132...

[0041] On the circumferential C, each first pocket 131 accommodates one roller 20, and each second pocket 132 accommodates two or more rollers 20, for example, two or three rollers 20 can be accommodated.

[0042] When two or more rollers 20 are accommodated in each second pocket 132, the two or more rollers may be arranged side by side along the axial direction A and / or the circumferential direction C.

[0043] Here, two or more rows of pockets are provided on the axial direction A of the cylindrical roller bearing. This reduces the size occupied by the side beam of the cage, increases the axial length ratio of the roller 20, and improves the bearing's load-bearing capacity.

[0044] Since the second pocket 132 can accommodate two or more rollers 20, the circumferential space occupied by the crossbeam can be reduced, the circumferential proportion of the rollers 20 can be increased, and the bearing capacity can be improved.

[0045] Here, preferably, adjacent rollers 20 of two or more rollers 20 accommodated in the same second pocket 132 are in contact in the circumferential direction C or have only a small gap.

[0046] Optionally, such as Figure 3 As shown, in the circumferential direction C, each second pocket 132 accommodates two rollers 20. Alternatively, in the axial direction, each second pocket 132 accommodates two or more rollers 20 arranged side by side along the axial direction.

[0047] Optionally, see Figure 4 and Figure 5 In each pocket 13 of at least one row of pockets, two or more rollers 20 are arranged along the axial direction A, with the axial end faces of adjacent rollers 20 in contact.

[0048] In one example, all rollers 20 have the same axial length. Of course, in some examples, the axial length of the rollers in different pockets 13 may be different. The axial length of each row of pockets 13 may be the same or different.

[0049] Understandable, Figure 4 In the example shown, the main point is to illustrate that along axis A, one roller or multiple rollers, such as two, can be placed in a pocket. The axial length of the first roller 210 in one row of pockets can be twice the axial length of the second roller 220 in the second row of pockets. Alternatively, the axial length of the first roller 210 can be equal to the axial length of the second roller 220.

[0050] Optionally, multiple second rollers 220 in the same pocket 13 are coaxially mounted together by interlocking their contacting axial end faces. For example, one second roller 220 may have a protrusion, and another second roller 220 may have a recess that mates with the protrusion. The protrusion may be cylindrical, hemispherical, or conical, etc.

[0051] Optionally, multiple coaxially arranged second rollers 220 in the same pocket 13 can be coaxially connected together by pins inserted into their shaft holes. For example, the second rollers 220 may have shaft holes, and a pin can be inserted into the shaft hole of an adjacent coaxial second roller 220 in the same pocket 13, or into the shaft holes of all coaxial second rollers 220 in the same pocket 13. For example, in Figure 4 When two coaxially arranged second rollers 220 are placed in a single pocket 13, the shaft hole can be a blind hole. Of course, when, for example, three coaxially arranged second rollers 220 are placed, the shaft hole of at least one second roller 220 can be a through hole.

[0052] Optionally, see Figures 3 to 5 In at least one row of pockets, on the circumferential direction C, a second pocket 132 is provided on each side of two adjacent first pockets 131, and two first pockets 131 are provided between two adjacent second pockets 132.

[0053] Optionally, in each pocket of at least one row of pockets 13, a plurality of rollers 20 are provided on the circumferential C, with the outer peripheral surfaces of circumferentially adjacent rollers 20 in contact with each other.

[0054] Optionally, see Figures 2A to 5 The cage 10 can be an integral cage, which includes two end side beams 111 located at both ends of the axial direction and one or more intermediate side beams 112 located between the two end side beams 111. The axial width of the intermediate side beam 112 can be greater than or equal to the axial width of the end side beams 111 and less than (in one example, it can also be equal to) twice the axial width of the end side beams 111.

[0055] Optionally, in axis A, the axial lengths of each row of pockets 13 are equal.

[0056] Alternatively, the cage 10 can be a metal cage, such as a copper cage. It can be manufactured by machining.

[0057] Preferably, the cylindrical roller bearing has only one race, which is the inner race.

[0058] Embodiments of this application also provide a wind turbine gearbox, which may include a planetary gear mechanism and a cylindrical roller bearing according to this application.

[0059] Optionally, the planetary gear mechanism includes a planet carrier and multiple planet gears rotatably mounted to the planet carrier via pins. Cylindrical roller bearings are mounted between the pins and the inner bores of the planet gears, with the inner walls of the planet gears forming the outer raceways of the cylindrical roller bearings. That is, the cylindrical roller bearing (itself) can have only an inner ring, without an outer ring. This reduces the radial dimension of the planetary gear mechanism. The cylindrical roller bearing of this application can have a larger load-carrying capacity, facilitating the miniaturization of the planetary gear mechanism.

[0060] It should be understood that at least some aspects or features of the above-described implementation methods, embodiments, or examples can be appropriately combined.

[0061] It is understood that, in this application, when the number of parts or components is not specifically limited, the number can be one or more, where multiple refers to two or more. For cases where the number of parts or components shown in the drawings and / or described in the specification is, for example, two, three, four, etc., this specific number is generally exemplary and not restrictive, and can be understood as multiple, i.e., two or more; however, this does not mean that this application excludes the case of one.

[0062] It should be understood that the above-described embodiments, examples, or examples are merely exemplary and are not intended to limit this application. Those skilled in the art can make various modifications and changes to the above-described embodiments, examples, or examples under the teachings of this application without departing from the scope of this application.

Claims

1. A cylindrical roller bearing for a wind turbine gearbox, comprising at least one race, a cage, and a plurality of rollers held by said cage, characterized in that, The outer circumference of the ring is provided with at least two rows of raceways, and each raceway contains one or more rows of rollers. The diameter of the rollers is 25 to 50 mm, and the ratio of the axial length to the diameter of the rollers is 3.2 to 11. In the axial direction of the cylindrical roller bearing, the cage is provided with two or more rows of pockets, each row of pockets including a plurality of pockets arranged adjacent to each other in the circumferential direction of the cylindrical roller bearing, and at least one pocket in at least one row of pockets having at least two rollers arranged side by side in the axial and / or circumferential directions.

2. The cylindrical roller bearing for wind turbine gearboxes according to claim 1, characterized in that, The ratio of the axial length to the diameter of the roller is 3.2 to 5.

5.

3. The cylindrical roller bearing for wind turbine gearboxes according to claim 1, characterized in that, At least one row of pockets includes a first pocket and a second pocket, the first pocket and the second pocket being arranged alternately in the circumferential direction. Each of the first pockets contains one of the rollers, and each of the second pockets contains two or more of the rollers, the two or more rollers being arranged side by side along the axial and / or circumferential direction.

4. The cylindrical roller bearing for wind turbine gearboxes according to claim 1, characterized in that, In each pocket of at least one row of pockets, two or more of the rollers are arranged axially with the axial end faces of adjacent rollers in contact.

5. The cylindrical roller bearing for wind turbine gearboxes according to claim 1, characterized in that, In each pocket of at least one column of pockets, multiple rollers are arranged in the circumferential direction, with the outer circumferential surfaces of adjacent rollers in contact.

6. The cylindrical roller bearing for a wind turbine gearbox according to claim 1, characterized in that, The rollers have the same axial length, and the axial lengths of the pockets in each row may be the same or different.

7. The cylindrical roller bearing for a wind turbine gearbox according to claim 1, characterized in that, The cage is an integral cage, which includes two end side beams located at both ends in the axial direction and one or more intermediate side beams located between the two end side beams. The axial width of the intermediate side beam is greater than or equal to the axial width of the end side beams and less than twice the axial width of the end side beams.

8. The cylindrical roller bearing for a wind turbine gearbox according to claim 1, characterized in that, Along the axial direction, the axial length of each row of pockets is equal.

9. The cylindrical roller bearing for a wind turbine gearbox according to claim 1, characterized in that, The cylindrical roller bearing has only one race, which is the inner race.

10. A wind turbine gearbox, characterized in that, The invention includes a planetary gear mechanism and a cylindrical roller bearing for a wind turbine gearbox according to any one of claims 1 to 9, the planetary gear mechanism comprising a planet carrier and a plurality of planet gears rotatably mounted to the planet carrier via a pin, the cylindrical roller bearing being mounted between the pin and the inner bore of the planet gears, the inner bore wall of the planet gears forming the outer raceway of the cylindrical roller.

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