Cylindrical roller bearing and cage therefor

Abstract

The application relates to a cylindrical roller bearing and a retainer thereof, the cylindrical roller bearing comprising an outer ring (1), an inner ring (2), rollers (4), a retainer (5) and an axial limiting structure; the retainer comprises a ring-shaped body, the ring-shaped body is circumferentially and uniformly provided with pockets (51), the rotation direction of the retainer (5) is defined as from back to front, the pocket (51) comprises a front side wall and a rear side wall (511), the rear side wall (511) is used for being in contact with the outer circumferential surface of the roller (4), the rear side wall (511) is a section of an ellipse, and the long axis (5111) of the ellipse extends in the front-rear direction. The retainer in the application can increase the contact area of the pocket and the roller while reducing the roller slip rate and the retainer vortex radius, thereby reducing the contact stress, lowering the abrasion, prolonging the service life of the bearing.

Description

Technical Field

[0001] This invention belongs to the field of bearings, and in particular relates to a cylindrical roller bearing and its cage. Background Technology

[0002] Cylindrical roller bearings are a fundamental component widely used in rotating machinery, providing radial support to the rotor.

[0003] Cylindrical roller bearings typically consist of an outer ring, inner ring, cage, and rollers. The cage has pockets that provide restraint and guidance for the rollers. In existing technology, these pockets are mostly planar pockets with flat sidewalls. When the rollers rotate, they make line contact with the sidewalls of the pockets, resulting in significant contact stress and causing rapid wear on both the rollers and the cage. Furthermore, at high speeds, the rollers are prone to slippage or outward movement under centrifugal force.

[0004] Chinese invention patent application CN111765171A (publication date October 13, 2020) discloses a pocket with a "V"-shaped cross-section on the sidewalls. The two "V"-shaped sidewalls fit together to confine the roller in an ideal position radially, which can effectively improve roller slippage, suppress the tendency of the roller to move outward, and reduce the roller whirl radius. However, the contact between the roller and the sidewall of the pocket is still line contact, which still has the problem of high contact stress affecting the service life.

[0005] Therefore, there is a need for a cylindrical roller bearing cage that can reduce roller slippage and cage whirl radius while also reducing contact stress between the rollers and the cage. Summary of the Invention

[0006] The purpose of this invention is to provide a cylindrical roller bearing and its cage, which reduces the roller slip rate and cage whirl radius, while reducing the contact stress between the roller and the cage, thereby improving bearing stability and extending service life.

[0007] To achieve the above objectives, the technical solution for the cylindrical roller bearing cage provided by this invention is as follows:

[0008] A cylindrical roller bearing cage includes an annular body with pockets evenly distributed around its circumference. The rotation direction of the cage is defined as from back to front. Each pocket includes a front sidewall and a rear sidewall for contacting the outer circumferential surface of the roller. The rear sidewall is an elliptical segment, and the major axis of the ellipse extends in the front-rear direction.

[0009] The beneficial effects are as follows: Firstly, in the radial direction, the elliptical shape provides a certain "V"-shaped positioning effect on the roller, which can limit the radial movement of the roller, reduce the roller slippage rate, and decrease the cage whirl radius. Simultaneously, the elliptical shape provides a certain circumferential envelope to the roller, ensuring a sufficiently large profile fit and contact area when the roller and the catch rub against each other, thereby reducing contact stress, decreasing wear rate, and extending bearing life. Finally, the sufficient clearance between the elliptical shape and the roller facilitates the formation of lubrication channels; even with prolonged rubbing and severe wear, the clearance remains, maintaining good lubrication.

[0010] As a further improvement, the front sidewall is an elliptical segment, the major axis of the ellipse extending in the front-rear direction.

[0011] The beneficial effect is that it ensures the same contact between the cage and the rollers whether the bearing rotates forward or backward.

[0012] As a further improvement, the center of the ellipse coincides with the center of the pocket, and the radius R of the circle is defined when the major axis length a and the minor axis length b of the ellipse are both 1. p With roller radius R r The difference is the guide gap of the pocket, and the guide gap value is 0.05mm-0.2mm. The guide point is determined according to the guide gap. The guide point is the intersection of the ellipse and the outer ring surface of the annular body. The ratio of the major axis length to the minor axis length of the ellipse is 1.0-1.1.

[0013] The beneficial effects are: it provides a parametric design method for elliptical shapes. First, the guide clearance value is determined based on the roller radius; then, the guide point of the ellipse is determined based on the guide clearance; finally, the ellipse shape is determined based on the guide point and the ratio of the major and minor axes. Simulation results show that when the ratio of the major and minor axes is between 1.0 and 1.1, the contact stress between the pocket elliptical surface and the roller is low, the wear rate is low, and the slippage rate and whirl radius are controlled within a small range.

[0014] As a further improvement, the radius R of the circle at the center of the pocket is... ε Larger than the inner diameter R of the cage n Smaller than the inner diameter R of the cage n With outer diameter R w The average of the sums.

[0015] The beneficial effects are: the support force of the pocket ellipse on the roller is directed towards the inner ring, further restricting the centrifugal motion of the roller and reducing the slip rate and whirl radius of the cage.

[0016] As a further improvement, the pocket is provided with a tool entry and exit hole, which can be used for the tool to enter and exit when machining the pocket.

[0017] The beneficial effects are: the cage pocket hole machining process can be milled, and the infeed and retraction holes can be used for milling cutter entry and exit, which facilitates the execution of the process.

[0018] To achieve the above objectives, the cylindrical roller bearing technical solution provided by this invention is as follows:

[0019] A cylindrical roller bearing includes an outer ring, an inner ring, rollers, an axial limiting structure, and a cage. The outer ring includes an outer raceway disposed on the inner wall, and the inner ring includes an inner raceway disposed on the outer wall. The cage includes an annular body with pockets evenly distributed circumferentially. The rotation direction of the cage is defined as from back to front. Each pocket includes a front sidewall and a rear sidewall for contacting the outer circumferential surface of the rollers. The rear sidewall is an elliptical segment, and the major axis of the ellipse extends in the front-rear direction.

[0020] The beneficial effects are as follows: Firstly, in the radial direction, the elliptical shape provides a certain "V"-shaped positioning effect on the roller, which can limit the radial movement of the roller, reduce the roller slippage rate, and decrease the cage whirl radius. Simultaneously, the elliptical shape provides a certain circumferential envelope to the roller, ensuring a sufficiently large profile fit and contact area when the roller and the catch rub against each other, thereby reducing contact stress, decreasing wear rate, and extending bearing life. Finally, the sufficient clearance between the elliptical shape and the roller facilitates the formation of lubrication channels; even with prolonged rubbing and severe wear, the clearance remains, maintaining good lubrication.

[0021] As a further improvement, the front sidewall is an elliptical segment, the major axis of the ellipse extending in the front-rear direction.

[0022] The beneficial effect is that it ensures the same contact between the cage and the rollers whether the bearing rotates forward or backward.

[0023] As a further improvement, the center of the ellipse coincides with the center of the pocket, and the radius R of the circle is defined when the major axis length a and the minor axis length b of the ellipse are both 1. p With roller radius R r The difference is the guide gap of the pocket, and the guide gap value is 0.05mm-0.2mm. The guide point is determined according to the guide gap. The guide point is the intersection of the ellipse and the outer ring surface of the annular body. The ratio of the major axis length to the minor axis length of the ellipse is 1.0-1.1.

[0024] The beneficial effects are: it provides a parametric design method for elliptical shapes. First, the guide clearance value is determined based on the roller radius; then, the guide point of the ellipse is determined based on the guide clearance; finally, the ellipse shape is determined based on the guide point and the ratio of the major and minor axes. Simulation results show that when the ratio of the major and minor axes is between 1.0 and 1.1, the contact stress between the pocket elliptical surface and the roller is low, the wear rate is low, and the slippage rate and whirl radius are controlled within a small range.

[0025] As a further improvement, the radius R of the circle at the center of the pocket is... ε Larger than the inner diameter R of the cage n Smaller than the inner diameter R of the cage n With outer diameter R w The average of the sums.

[0026] The beneficial effects are: the support force of the pocket ellipse on the roller is directed towards the inner ring, further restricting the centrifugal motion of the roller and reducing the slip rate and whirl radius of the cage.

[0027] As a further improvement, the pocket is provided with a tool entry and exit hole, which can be used for the tool to enter and exit when machining the pocket.

[0028] The beneficial effects are: the cage pocket hole machining process can be milled, and the infeed and retraction holes can be used for milling cutter entry and exit, which facilitates the execution of the process.

[0029] As a further improvement, a retaining edge is provided at one end of the inner ring.

[0030] Furthermore, the axial limiting mechanism is a retaining ring, which cooperates with the retaining edge to limit the axial position of the roller.

[0031] The beneficial effects are: the edge and retaining ring structures are simple and easy to arrange. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention;

[0033] Figure 2 for Figure 1 A three-dimensional view of the inner circle;

[0034] Figure 3 for Figure 1 The radial cross-sectional view of the cylindrical roller bearing shown is shown.

[0035] Figure 4 for Figure 1 Schematic diagram of the cage structure;

[0036] Figure 5 for Figure 1 Geometric diagram of the contact between the center pocket and the cage;

[0037] Figure 6 for Figure 5 Simulation results of average wear rate for different ratios of major and minor axis lengths;

[0038] Figure 7 for Figure 5 Simulation results of cage whirl radius with different ratios of major and minor axis lengths;

[0039] Figure 8 for Figure 5 Simulation results of slippage rates for different ratios of major and minor axis lengths;

[0040] Explanation of reference numerals in the attached figures:

[0041] 1. Outer ring; 2. Inner ring; 3. Retaining ring; 4. Roller; 5. Cage; 11. Outer raceway; 21. Inner raceway; 22. Sidewall; 51. Pocket; 511. Rear sidewall; 512. End wall; 513. Infeed / retractor hole; 5111. Long shaft; 5112. Short shaft; 5113. Guide point Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described embodiments are merely some embodiments of the invention, not all embodiments. The components of the embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0043] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0044] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any actual relationship or order between these entities or operations. Furthermore, terms such as "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the process or method that includes said element.

[0045] The present invention will be further described in detail below with reference to the embodiments.

[0046] Specific embodiment 1 of the cylindrical roller bearing provided by the present invention:

[0047] like Figures 1 to 4 As shown, the cylindrical roller bearing includes an outer ring 1, an inner ring 2, a retaining ring 3, rollers 4, and a cage 5. The inner wall of the outer ring 1 is provided with an outer raceway 11 for rolling contact with the rollers 4, and the outer wall of the inner ring 2 is provided with an inner raceway 21 for rolling contact with the rollers 4. One end of the inner ring 2 is also provided with a retaining edge 22. The cage 5 includes an integral annular body with a plurality of pockets 51 evenly distributed around its circumference. The rollers 4 are placed in the pockets 51. With the cooperation of the retaining ring 3 and the retaining edge 22, the axial positions of the rollers 4 and the cage 5 are fixed.

[0048] like Figure 4 and Figure 5 As shown, the rotation direction of cage 5 is defined as from back to front, i.e. Figure 5 The clockwise direction is specified. The pocket 51 includes a rear sidewall 511 that can contact the outer peripheral surface of the roller 4; an end wall 512 that can contact the end face of the roller 4; and a tool entry / exit hole 513 that can be used for tool entry and exit during milling. The rear sidewall 511 is an elliptical section, with the major axis 5111 extending in the front-back direction, and its contour is determined by the major axis 5111 and the minor axis 5112.

[0049] like Figure 5 As shown, the center of the pocket 51 coincides with the center of the major axis 5111 and the minor axis 5112. Let the length of the major axis 5111 be a and the length of the minor axis 5112 be b. Define the radius R of the circle when the length of the major axis 5111 (a) and the length of the minor axis 5112 (b) of the ellipse are both 1. p With roller 4 radius R r The difference is the guide clearance of pocket 51, which is 0.05mm-0.2mm. Based on the guide clearance, guide point 5113 is determined. This guide point 5113 is a point on the ellipse. When the ratio of the length a of the major axis 5111 to the length b of the minor axis 5112 is 1.0-1.1, the roller 4 and the rear sidewall 511 have a relatively large contact area. Based on MATLAB, the wear rate, roller slippage rate, and cage whirl radius of the cage 5 when a / b is 1.0-1.1 were simulated and calculated. The working conditions were set as follows: inner ring speed 20000r / min, radial load 1200N. The wear rate results are as follows. Figure 6 As shown, it can be seen that when a / b is 1, i.e., the cross-section of the rear sidewall 511 is circular, the wear rate of the cage 5 is the highest. When a / b is greater than 1, i.e., the rear sidewall 511 is an elliptical segment, the wear rate is smaller than when a / b is 1. The simulation results for the whirl radius and slippage rate are as follows: Figure 7 and Figure 8As shown, it can be seen that when a / b is greater than 1, both the eddy radius and the slippage rate are smaller than when a / b is 1.

[0050] The cross-sectional structure of the front sidewall, opposite to the rear sidewall 511, is identical to that of the rear sidewall 511, ensuring consistent contact between the pocket 51 and the roller 4 when the bearing rotates rearward, i.e., counterclockwise. To facilitate the insertion of the roller 4 into the pocket 51, the width B of the inner edge of the pocket 51 is... in It should be larger than the diameter of the roller.

[0051] like Figure 5 As shown, the arc-shaped dashed line represents the central distribution circle of the pocket 51, with a radius R. ε The inner diameter R of the cage is greater than 5. n Less than the inner diameter R of the cage 5 n With outer diameter R w The average value of the sum, i.e., the center of the pocket 51 is closer to the inner raceway 21, can make the resultant force of the support force of the rear sidewall 511 on the roller 4 be directed towards the inner raceway 21. At the same time, the elliptical shape is similar to a "V" shape, so it can more effectively limit the radial centrifugal tendency of the roller 4 and reduce the cage whirl radius.

[0052] Specific embodiment 2 of the cylindrical roller bearing provided by the present invention:

[0053] The main difference between Example 2 and Example 1 is that in Example 1, the cage is a one-piece ring structure. In this example, the cage is a multi-segment split structure. This structure facilitates the processing of pockets, and after processing each segment of pockets, they are assembled into a ring.

[0054] Specific embodiment 3 of the cylindrical roller bearing provided by the present invention:

[0055] The main difference between Embodiment 3 and Embodiment 1 is that in Embodiment 1, the rear sidewall 511 and the front sidewall have the same cross-sectional structure. In this embodiment, the bearing is fixed only by rotating forward, so only the rear sidewall 511 has an elliptical cross-section, while the front sidewall is planar.

[0056] Specific embodiment 4 of the cylindrical roller bearing provided by the present invention:

[0057] The main difference between Embodiment 4 and Embodiment 1 is that in Embodiment 1, one end of the inner ring 2 is provided with a retaining flange 22, which cooperates with the retaining ring 3 to complete the axial positioning. In this embodiment, both ends of the inner ring 2 are provided with retaining flanges 22, and the axial position of the roller 4 and the cage 5 is limited by determining the interval between the retaining flanges 22.

[0058] An embodiment of the cylindrical roller bearing cage in this invention:

[0059] This embodiment is the cage described in any of the embodiments 1-4 of the cylindrical roller bearing described above, and will not be described in detail here.

[0060] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still make modifications to the technical solutions described in the foregoing embodiments without creative effort, or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A cylindrical roller bearing cage comprising a ring-like body having pockets circumferentially distributed thereon, the direction of rotation of the cage being defined as from back to front, the pockets comprising a front side wall and a back side wall, the back side wall being intended to come into contact with the outer peripheral surface of the rollers, characterized in that, The rear side wall is a segment of an ellipse, the center of the ellipse coincides with the center of the pocket, the major axis of the ellipse extends along the tangent direction of the circle of distribution of the pocket center, the minor axis extends along the radial direction of the retainer, and the normal line extends along the axial direction of the retainer, so as to limit the radial centrifugal movement of the roller, and ensure that the roller and the pocket have sufficient profile fit and contact area when colliding and rubbing.

2. The cylindrical roller bearing cage of claim 1, wherein, The front side wall is a segment of the ellipse.

3. The cylindrical roller bearing cage according to claim 1 or 2, characterized in that the length of the major axis of the ellipse a the length of the minor axis b the radius of the circle when the ratio of the length of the major axis to the length of the minor axis is 1 R p the radius of the roller R r the difference between the length of the major axis of the ellipse and the length of the minor axis is the guide gap of the pocket, the guide gap is 0.05mm-0.2mm, the guide point is determined according to the guide gap, the guide point is the intersection point of the outer ring surface of the elliptical and annular body, the ratio of the length of the major axis of the ellipse to the length of the minor axis is 1.0-1.

1.

4. The cylindrical roller bearing cage of claim 3, wherein, the average of the sum of the pocket center distribution circle radius R ε greater than the cage inner diameter R n less than the cage inner diameter R n the average of the sum of the pocket center distribution circle radius R w the average of the sum of the pocket center distribution circle radius 5. The cylindrical roller bearing cage of claim 4, wherein, The pocket is provided with an in-out tool hole for the entry and exit of a tool during machining of the pocket.

6. A cylindrical roller bearing comprising an outer ring, an inner ring, rollers, axial stop structures and a cage, the outer ring comprising an outer raceway provided on an inner wall, the inner ring comprising an inner raceway provided on an outer wall, characterized in that, The retainer comprises a ring-shaped body, the ring-shaped body is circumferentially uniformly distributed with pockets, the rotation direction of the retainer is defined as from rear to front, the pocket comprises a front side wall and a rear side wall, the rear side wall is used for contacting the outer peripheral surface of the roller; the rear side wall is a segment of an ellipse, the center of the ellipse coincides with the center of the pocket, the major axis of the ellipse extends along the tangent direction of the circle of distribution of the pocket center, the minor axis extends along the radial direction of the retainer, and the normal line extends along the axial direction of the retainer, so as to limit the radial centrifugal movement of the roller, and ensure that the roller and the pocket have sufficient profile fit and contact area when colliding and rubbing.

7. The cylindrical roller bearing of claim 6, wherein, One end of the inner ring is provided with a stop edge.

8. The cylindrical roller bearing of claim 7, wherein, The axial limiting structure comprises a stop ring, the stop ring is matched with the stop edge, and is used for limiting the axial position of the roller.

9. The cylindrical roller bearing of claim 6, wherein, The front side wall is a segment of the ellipse.

10. The cylindrical roller bearing according to claim 6 or 9, characterized in that the length of the major axis of the ellipse a the length of the minor axis b the radius of the circle when the ratio of the length of the major axis to the length of the minor axis is 1 R p the radius of the roller R r the difference between the length of the major axis of the ellipse and the length of the minor axis is the guide gap of the pocket, the guide gap is 0.05mm-0.2mm, the guide point is determined according to the guide gap, the guide point is the intersection point of the outer ring surface of the elliptical and annular body, the ratio of the length of the major axis of the ellipse to the length of the minor axis is 1.0-1.

1.

11. The cylindrical roller bearing of claim 10, wherein, The pocket center distribution circle radius R ε The average value of the sum of the outer diameter R n The average value of the sum of the outer diameter R n The average value of the sum of the outer diameter R w The average value of the sum of the outer diameter 12. The cylindrical roller bearing of claim 11, wherein, The pocket is provided with an in-out tool hole for the entry and exit of a tool during machining of the pocket.

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