A cage and bearing

Abstract

The application discloses a cage and bearing, the cage comprises a first ring and a second ring, and a plurality of beams connecting the first ring and the second ring, the plurality of beams are spaced apart from each other in a circumferential direction of the cage and define pockets between adjacent beams for accommodating rolling elements of a bearing, wherein side surfaces of the beams in the circumferential direction comprise first and second pressure ramp surfaces spaced apart from each other, and a concave surface extending from the first pressure ramp surface towards a longitudinal center line of the beam and towards a longitudinal end of the beam at least at one end of the pocket. Through the cage, bearing assembly is facilitated, the use of large instruments during assembly is avoided, and damage to various components of the bearing during assembly is reduced.

Description

Technical Field

[0001] This application relates to the field of bearings, and in particular to bearings for the wind power industry and cages used in bearings. Background Technology

[0002] With the rapid development of the wind power industry, increasing power and improving efficiency are the main performance goals pursued by wind turbine units. The development of large-size, high-load, lightweight, stable-operating, and low-cost bearings to match these requirements is a target for the wind power bearing industry. Large bearings (especially single-row tapered roller bearings) are currently the development trend, but the high cost and complexity of cage structure design and manufacturing are bottlenecks restricting the performance of wind power tapered roller bearings. To meet the high-performance requirements of wind turbine bearings, it is urgent to research a special structure for tapered roller bearing cages to achieve these performance requirements.

[0003] Due to the excessive size of large tapered roller bearings, it is difficult to employ large cage shrinkage molds and large presses for bearing assembly during assembly. Traditionally, to address this tooling issue, the cage is cut open first, then the rollers and inner ring are installed, and finally the cut portion is welded circumferentially. However, this carries the risk of creating weak points in the cage's strength. Furthermore, minimal weld deformation of the cage is required, making the process challenging. Additionally, the material must be weldable, thus limiting the cage material's hardness and making it prone to deformation. Summary of the Invention

[0004] Therefore, this application aims to solve the above-mentioned or other problems existing in the prior art.

[0005] One aspect of this application is to provide a cage that facilitates bearing assembly, avoids the use of large machinery (e.g., large cage shrink molds, large presses for bearing assembly, etc.) during the assembly process, and reduces damage to various bearing components (especially the cage, rolling elements, bearing inner ring, etc.) during the assembly process.

[0006] Another aspect of this application is to provide a cage suitable for a bearing assembly method that combines skid mounting and heat mounting.

[0007] According to one aspect of this application, a retainer is provided, the retainer including a first ring and a second ring, and a plurality of beams connecting the first ring and the second ring, the plurality of beams being spaced apart from each other in the circumferential direction of the retainer and defining pockets between adjacent beams for receiving rolling elements of a bearing, wherein the side surfaces of the beams in the circumferential direction include a first pressure bevel and a second pressure bevel spaced apart from each other, and a concave surface extending from the first pressure bevel toward the longitudinal centerline of the beam and toward the longitudinal end of the beam at at least one end of the pocket.

[0008] The cage of this application ensures smooth operation of the rolling elements, guarantees the uprighting effect of the cage pocket on the rolling elements, and reduces wear or premature failure of the cage pressure slope. Moreover, it helps to increase the height of the flange of the bearing inner ring, avoiding the phenomenon of rolling elements falling off during bearing assembly due to the limited flange height (traditionally, the flange height of the bearing inner ring should not be too large, otherwise the bearing inner ring will not be able to be installed smoothly). In turn, the increased flange height helps to enhance the uprighting effect of the flange on the rolling elements.

[0009] Optionally, the concave surface may form a dovetail groove extending at an inclined surface from the first slope surface toward the longitudinal centerline of the beam and toward the longitudinal end of the beam.

[0010] Optionally, the concave surface may form a rectangular groove that is sunken relative to the first slope surface toward the longitudinal center line of the beam.

[0011] Optionally, the side surface may further include a transition slope that extends from the first pressure slope and the second pressure slope in the radial direction of the retainer.

[0012] Optionally, the pocket may include a small end and a large end, and at the small end, the side surface may include a concave surface extending from the first slope surface toward the longitudinal centerline of the beam and toward the longitudinal end of the beam.

[0013] Optionally, the side surface may further include a recessed surface located between the first and second slope surfaces and concave relative to the first and second slope surfaces. This arrangement of the cage in this application provides sufficient bearing lubrication and prevents damage to the working surfaces of the rolling elements.

[0014] To further enhance the reliability of bearing lubrication, the side surface may optionally include: a first oil groove surface extending from the concave surface at one end of the pocket, and / or a second oil groove surface extending from the second pressure slope surface at the other end of the pocket.

[0015] Optionally, the offset distance of the center of the sunken surface in the longitudinal direction of the beam relative to the center of the beam in the longitudinal direction can be within 20 percent of the longitudinal length of the beam.

[0016] Optionally, the length of the concave surface in the longitudinal direction of the beam may be 1 / 6 to 1 / 2 of the longitudinal length of the beam.

[0017] Optionally, the length of the first slope surface and / or the second slope surface in the longitudinal direction of the beam may be greater than 1 / 6 of the longitudinal length of the beam.

[0018] Optionally, the cage may be an integral cage.

[0019] According to another aspect of this application, a bearing is provided, including an outer ring, an inner ring, and a cage as described above, the cage being used to retain rolling elements located between the inner ring and the outer ring.

[0020] Optionally, the bearing may be a single-row tapered roller bearing. Attached Figure Description

[0021] Figure 1 This is a schematic cross-sectional view of a tapered roller bearing according to an embodiment of this application;

[0022] Figure 2 This is a perspective view of a cage according to an embodiment of this application;

[0023] Figure 3 This is a partial cross-sectional view of the cage according to an embodiment of this application;

[0024] Figure 4 This is a partial perspective view of the cage viewed from the radially inner side according to an embodiment of this application;

[0025] Figure 5 This is a partial perspective view of the cage viewed from the radially outer side according to an embodiment of this application;

[0026] Figure 6 This is a partial cross-sectional view of the cage and rolling element according to an embodiment of the present application, showing the original position and the expanded position of the cage after heating, as well as the original position, the radially shifted position of the rolling element after heating, and the position where the rolling element is further radially raised outward by skid mounting.

[0027] Figure 7 yes Figure 6 A partial enlarged view of part I, wherein, for clarity, only the cage is shown and the rolling elements are not shown; and

[0028] Figure 8 yes Figure 6 A magnified view of part J in the image.

[0029] Explanation of reference numerals in the attached figures:

[0030] 1-Outer ring; 2-Cage; 3-Inner ring; 4-Rolling element; 5-First ring; 6-Second ring; 7-Beam; 10-Pocket; 11-First oil groove surface; 12-Concave surface; 13-First pressure slope surface; 14-Sinking surface; 15-Second pressure slope surface; 16-Second oil groove surface; 17-Turnover part; 18-Transition slope surface; 31-Side guard; C0-Cage original position; C1-Cage thermal expansion position; R0-Rolling element original position; R1-Rolling element thermal expansion position; R2-Rolling element skid-mounted raised position. Detailed Implementation

[0031] The features and exemplary embodiments of various aspects of this application will now be described in detail. Numerous specific details are set forth in the following detailed description to provide a comprehensive understanding of this application. However, it will be apparent to those skilled in the art that this application can be implemented without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of this application by illustrating examples. In the accompanying drawings and the following description, at least some well-known structures and techniques are not shown to avoid unnecessarily obscuring the application; and, for clarity, the dimensions of some structures may be exaggerated. Furthermore, the features, structures, or characteristics described below can be combined in any suitable manner in one or more embodiments.

[0032] like Figure 1 As shown, the bearing includes an outer ring 1, an inner ring 3, rolling elements 4 disposed between the outer ring 1 and the inner ring 3, and a cage 2 for retaining and guiding the rolling elements 4. Here, this application is described using a single-row tapered roller bearing as an example, but the types of bearings to which this application applies are not limited to this. In the case of a tapered roller bearing, the rolling element 4 is a tapered roller.

[0033] Figure 2 A perspective view of the cage is shown. (As shown) Figure 2 As shown, the cage 2 includes a first ring 5 and a second ring 6, and a plurality of beams 7 connecting the first ring 5 and the second ring 6. The plurality of beams 7 are spaced apart from each other in the circumferential direction of the cage 2 and define pockets 10 for accommodating rolling elements of the bearing between adjacent beams 7. Thus, the cage 2 is a frame-type cage or a closed cage. In the case of a tapered roller bearing, the diameter of the first ring 5 of the cage 2 is larger than the diameter of the second ring 6, and the pockets 10 have a large end and a small end, respectively adapted to the large end and small end of the rolling element 4 accommodated in the pockets 10.

[0034] like Figure 3 and Figure 4As shown, the side surfaces of the beam 7 of the cage 2 according to this application (taking one side surface as an example) in the circumferential direction include a first bevel surface 13 and a second bevel surface 15 spaced apart from each other. The bevel surface refers to the surface of the cage that contacts the rolling element, guiding the cage in the load area and the rolling element in the non-load area. Preferably, the bevel surface can contact the rolling element tangentially; in other words, the bevel surface is the tangential surface where the rolling element contacts the beam of the cage. Because two bevel surfaces are used in the longitudinal direction X of the beam 7, the cage 2 can contact the rolling element over a larger span, ensuring smoother operation of the rolling element and reducing noise.

[0035] Furthermore, the side surface of the beam 7 of the retainer 2 also includes a longitudinal centerline S (e.g., at at least one end of the pocket 10) extending from the first slope surface 13 toward the beam 7. Figure 4 (as shown) and a concave surface 12 extending toward the longitudinal end of beam 7.

[0036] More preferably, such as Figure 3 and Figure 4 As shown, at the small end of the pocket, the side surface of the retainer 2 in the circumferential direction includes a concave surface 12 extending from the first pressure slope surface 13 toward the longitudinal centerline S of the beam 7 and toward the longitudinal end of the beam. The concave surface 12 may form a groove extending from the first pressure slope surface 13 away from the interior of the pocket and toward the longitudinal centerline S of the beam 7.

[0037] More specifically, such as Figure 4 As shown, the concave surface 12 can form a dovetail groove extending from the first slope surface 13 toward the longitudinal centerline S of the beam 7 and toward the longitudinal end of the beam 7 with an inclined surface. Here, the surface containing the concave surface 12 (e.g., the dovetail groove) is not coplanar with the surface containing the first slope surface 13; the surface containing the concave surface 12 is further away from the inside of the pocket and closer to the longitudinal centerline S of the beam 7 relative to the first slope surface 13. For example, as... Figure 3 As shown, the concave surface 12 begins to extend toward the longitudinal end of the beam 7 at the turning point 17 between the first slope surface 13 and the concave surface 12.

[0038] The concave surface 12 does not contact the rolling element 4. The concave surface 12 is further away from the rolling element 4 relative to the first pressure slope surface 13, which makes the radial movement or radial outward movement of the rolling element 4 within the pocket 10 (especially at the small end of the pocket) greater, thereby increasing the inner pitch circle diameter of the small end of the rolling element (i.e., the diameter of the circle formed by connecting the points closest to the radial interior at the small end of all rolling elements in the rolling element row).

[0039] In addition, the concave surface 12 may also form a rectangular groove that is sunken relative to the longitudinal center line S of the beam 7 facing the cage 2 relative to the first pressure slope surface 13. Of course, this application is not limited to this. The concave surface 12 may also be any other shape of concave surface or groove that is not coplanar with the first pressure slope surface 13, does not contact the rolling element 4, and is further away from the rolling element 4 relative to the first pressure slope surface 13 to ensure that the rolling element 4 has an increased amount of radial movement in the pocket 10.

[0040] By employing a two-section pressure surface, the cage can contact the rolling elements over a larger span in the longitudinal direction, ensuring smoother operation of the rolling elements and reducing noise.

[0041] Furthermore, by providing a concave surface at at least one end of the pocket (preferably at the small end of the pocket) that is further away from the rolling element relative to the bevel surface, this allows for skid mounting of the cage and bearing inner ring. More specifically, during skid mounting, after the bearing inner ring has entered the assembly of the cage and rolling element, the small flange of the inner ring is skid-mounted using the small end of the cage as a fulcrum. Due to the presence of this concave surface, the small end of the rolling element can be moved radially outward, thereby increasing the inner pitch circle diameter of the rolling element. This creates space for the small flange of the bearing inner ring, allowing the bearing inner ring to be mounted radially inside the cage and for the small flange of the bearing inner ring to abut against the end surface of the rolling element.

[0042] Additionally, the presence of the concave surface 12 can increase the height of the flange of the inner ring of the bearing. (See reference...) Figures 6 to 8 As described, Figure 6 The original position C0 of the cage and the thermally expanded position C1 of the cage after heating are shown. The original position R0 of the rolling element in the pocket 10 of the cage 2, the thermally expanded position R1 of the rolling element after heating and radially outward movement, and the skid-raised position R2 of the rolling element during skid mounting due to the presence of the concave surface 12 are also shown. Figure 7 It shows Figure 6 A partial enlarged view of part I (for clarity, only the cage 2 is shown, and the rolling element 4 is not shown), which shows the radial thermal expansion t1 of the cage 2 from its original position C0 to its thermal expansion position C1. Figure 8 It shows Figure 6A partially enlarged view of part J shows the radial movement t2 in the pocket caused by heating from the original position R0 of the rolling element to the thermal expansion position R1 of the rolling element, and the radial elevation t3 from the thermal expansion position R1 of the rolling element to the skid-mounted raised position R2 of the rolling element. It can be seen that the radial height of the retaining edge 31 of the bearing inner ring, which abuts against the inner edge of the rolling element 4, can be t1+t2+t3+t4+r0, where t4 represents the interference lock amount of the retaining edge of the inner ring relative to the rolling element in the radial direction, and r0 represents the radius of the chamfer at the axial end of the rolling element. Therefore, the structure of the cage proposed in this application is particularly suitable for a combination of heat-fitting and skid-mounting. Compared to simple heat-fitting, the presence of the concave surface 12 (the presence of the radial elevation t3) helps to increase the height of the retaining edge 31, which effectively avoids the problem of the rolling element easily falling off due to the limitation of the retaining edge height (e.g., limited by material expansion limitations) preventing the retaining edge height from being too large. Compared to simple skid mounting, the thermal deformation of the small end of the cage helps to increase the height of the flange 31 and effectively avoids the problem of rolling elements falling off, thereby improving the stability of the bearing with the cage.

[0043] In addition, increasing the height of the flange 31 improves the straightening effect of the flange 31 on the rolling element, ensuring the smooth operation of the rolling element.

[0044] Furthermore, since the cage with the above structure is particularly suitable for the assembly of bearings with a combination of skid mounting and hot mounting, there is no need to cut and then weld the cage during the assembly process. Therefore, it is particularly preferred that the cage of this application can be an integral cage.

[0045] Furthermore, the side surface of the beam 7 of the cage 2 may also include a recessed surface 14 located between the first pressure slope 13 and the second pressure slope 15 and recessed relative to the first pressure slope 13 and the second pressure slope 15. Preferably, the recessed surface 14 may be parallel to the first pressure slope 13 and / or the second pressure slope 15. The recessed surface 14 does not contact the rolling element 4.

[0046] Additionally, the side surface of the beam 7 of the cage 2 may also include a first oil groove surface 11 extending from the concave surface 12 at one end of the pocket 10 and / or a second oil groove surface 16 extending from the second pressure slope surface 15 at the other end of the pocket 10. Here, the first oil groove surface 11 and the second oil groove surface 16 ensure that the four corners of the pocket 10 do not interfere with the chamfer of the rolling element 4 when the cage is unstable.

[0047] In addition, the presence of the aforementioned sunken surface 14 and oil groove surfaces 11 and 16 allows for the storage of more grease, which is beneficial for the discharge of grease and waste grease from the rolling elements and cage.

[0048] For a retainer beam with the above structure, the distribution of the first slope surface 13, the second slope surface 15, the concave surface 12, and the sunken surface 14, as well as their proportions or lengths, are also crucial.

[0049] For example, such as Figure 3 As shown, the offset distance D of the center A of the sinking surface 14 located between the first slope surface 13 and the second slope surface 15 in the longitudinal direction X of the beam 7 relative to the center B of the beam 7 in the longitudinal direction X can be within 20% of the longitudinal length L of the beam 7, preferably within 10% of the longitudinal length L of the beam 7, and more preferably, the offset distance D is within 10 mm. Here, the longitudinal length L of the beam 7 is the distance between the two ends of the defining pocket edge of the beam 7 in the longitudinal direction, and therefore this longitudinal length L can also correspond to the longitudinal length of the pocket 10 at the beam 7. Figure 3 For clarity, the offset distance D between A and B is exaggerated; this diagram is not intended to define the actual range of the offset distance D. That is, the recessed surface 14 is preferably located in the middle portion of the beam in the longitudinal direction, which also corresponds to the middle portion of the pocket in the longitudinal direction. This is because, in most operating conditions, the rolling element contacts the raceways of the inner and outer rings of the bearing in intermediate contact, and the rolling element guide cage should avoid the functional surface of the rolling element (i.e., the middle of the rolling element).

[0050] Furthermore, the length of the concave surface 12 in the longitudinal direction X of the beam 7 is preferably 1 / 6 to 1 / 2 of the longitudinal length L of the beam 7. If the length of the concave surface 12 is too short, it will be difficult to install by skid; if the length of the concave surface 12 is too long, it will affect the length of the pressure slope, thus failing to ensure the smooth operation of the rolling element or the righting effect of the cage pocket on the rolling element.

[0051] Additionally, the length of the first slope surface 13 and / or the second slope surface 15 in the longitudinal direction X of the beam 7 is preferably greater than 1 / 6 of the longitudinal length L of the beam to ensure sufficient area for guiding the rolling elements. Preferably, the length of the first slope surface 13 and / or the second slope surface 15 may be greater than 10 mm, or between 1 / 6 and 1 / 5 of the longitudinal length L of the beam.

[0052] In addition, the above describes the sloping surface of the cage beams; however, the side surfaces of the cage beams may also include transition surfaces or unsloped surfaces. Figure 5 A partial perspective view of the cage, viewed from its radially outer side, is shown. A transition surface 18 extends radially outward from the beveling surfaces (i.e., the first and second beveling surfaces) in the radial direction of the cage, and this transition surface does not contact the rolling elements. However, this application is not limited to this. The cage may also not include such a transition surface or an unbeveling surface.

[0053] The bearing with the cage provided in the above embodiments can be assembled using the following method, referring to... Figure 6 The rolling element 4 is installed into the cage 2. Both the rolling element 4 and the cage 2 are heated to cause expansion. The cage 2 expands radially outward from its original position C0 to the thermal expansion position C1, and the rolling element 4 expands radially outward or moves to the thermal expansion position R1 from its original position R0. At this point, the bearing inner ring 3 can be introduced radially inward from the cage 2 at an angle relative to its longitudinal axis. First, a portion of the flange 31 of the bearing inner ring 3 abuts against the end surface of the rolling element 4. Then, the remaining portion of the flange 31 is pried (using the small end of the rolling element 4 as a fulcrum). Due to the presence of the concave surface 12, the rolling element 4 can be further moved radially outward to the pried-raised position R2, creating space for the flange 31 of the bearing inner ring 3. This allows the portion of the remaining flange 31 to smoothly engage with the end surface of the rolling element 4, thus completing the assembly of the cage 2, the rolling element 4, and the inner ring 3. This section describes only the assembly between the cage 2, the rolling element 4, and the inner ring 3 in detail, without describing the assembly process of the outer ring, which may be installed on the radially outer side of the cage 2 before or after this process.

[0054] Therefore, the above-mentioned cage structure is particularly suitable for the assembly of bearings using a combination of skid mounting and hot mounting. This is especially advantageous for large bearings (particularly tapered roller bearings) in the wind power industry. As a result, there is no need to use large cage shrinkage molds or large presses for bearing assembly. This solves the problems of lack of extension tooling for cages, lack of shrinkage mold tooling for assembly, and lack of large presses for bearing assembly.

[0055] Furthermore, there is no need to cut and weld the cage beforehand, thus ensuring the strength of the cage.

[0056] In addition, the problem of hot-mounting the rolling element falling off was solved, as was the problem of skid mounting scratching the small end of the rolling element.

[0057] In addition, the recessed surface solves the problem of poor lubrication of the rolling elements and avoids damage to the working surface of the rolling elements by the cage.

[0058] Furthermore, the two-section beveled surface makes the rolling elements run more smoothly within the cage, enhancing the cage's ability to straighten the rolling elements. Additionally, increasing the height of the inner ring flange further enhances the flange's ability to straighten the rolling elements.

[0059] The specific embodiments of this application have been described in detail above. Although some embodiments have been shown and described, those skilled in the art should understand that modifications and improvements can be made to these embodiments without departing from the principles and spirit of this application as defined by the claims and their equivalents, and such modifications and improvements should also be within the protection scope of this application.

Claims

1. A cage comprising a first ring (5) and a second ring (6), and a plurality of beams (7) connecting the first ring (5) and the second ring (6), the plurality of beams (7) being spaced apart from each other in the circumferential direction of the cage and defining pockets (10) between adjacent beams (7) for receiving rolling elements of a bearing, characterized in that, The beam (7) includes a first pressure slope (13) and a second pressure slope (15) spaced apart from each other on its side surface in the circumferential direction, and a concave surface (12) extending from the first pressure slope (13) toward the longitudinal centerline (S) of the beam (7) and toward the longitudinal end of the beam (7) at at least one end of the pocket (10), the concave surface (12) enabling the rolling element in the pocket (10) to move radially outward at one end near the concave surface (12) to provide clearance space for the flange of the inner ring of the bearing; The side surface also includes a sunken surface (14) located between the first slope surface (13) and the second slope surface (15) and recessed relative to the first slope surface (13) and the second slope surface (15). The offset distance (D) of the center (A) of the sunken surface (14) in the longitudinal direction (X) of the beam (7) relative to the center (B) of the beam (7) in the longitudinal direction (X) is within 20 percent of the longitudinal length (L) of the beam (7).

2. The cage according to claim 1, characterized in that, The concave surface (12) forms a dovetail groove extending from the first slope surface (13) toward the longitudinal centerline (S) of the beam (7) and toward the longitudinal end of the beam (7) with an inclined surface.

3. The cage according to claim 1, characterized in that, The concave surface (12) forms a rectangular groove that sinks relative to the longitudinal centerline (S) of the beam (7) relative to the first slope surface (13).

4. The cage according to claim 1, characterized in that, The side surface also includes a transition slope (18) that extends from the first pressure slope (13) and the second pressure slope (15) in the radial direction of the retainer.

5. The cage according to claim 1, characterized in that, The pocket (10) includes a small end and a large end, wherein at the small end, the side surface includes a concave surface (12) extending from the first slope surface (13) toward the longitudinal centerline (S) of the beam (7) and toward the longitudinal end of the beam (7).

6. The cage according to any one of claims 1 to 5, characterized in that, The side surface further includes: a first oil groove surface (11) extending from the concave surface (12) at one end of the pocket (10), and / or a second oil groove surface (16) extending from the second slope surface (15) at the other end of the pocket (10).

7. The cage according to any one of claims 1 to 5, characterized in that, The length of the concave surface (12) in the longitudinal direction (X) of the beam (7) is 1 / 6 to 1 / 2 of the longitudinal length (L) of the beam (7).

8. The cage according to any one of claims 1 to 5, characterized in that, The length of the first slope surface (13) and / or the second slope surface (15) in the longitudinal direction (X) of the beam (7) is greater than 1 / 6 of the longitudinal length (L) of the beam (7).

9. The cage according to any one of claims 1 to 5, characterized in that, The cage is an integral cage.

10. A bearing comprising an outer ring (1), an inner ring (3), and a cage according to any one of claims 1 to 9, the cage being used to retain a rolling element (4) located between the inner ring (3) and the outer ring (1).

11. The bearing according to claim 10, characterized in that, The bearing is a single-row tapered roller bearing.

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