Double-row integrated needle bearing structure

Abstract

The utility model discloses a double row integrated needle roller bearing structure relates to bearing technical field. The structure includes retainer and two rows of needle roller. The retainer is integrated structure, contains the inner race and outer ring that are connected through the connecting portion, and forms two rows of the window hole of accommodating needle roller in radial direction. The window hole section on the inner race and the outer ring is continuous M shape, and the opening direction of both is opposite, is helpful to offsetting the processing deformation, ensures the retainer flatness. The inner wall of window hole is equipped with the inclined guide surface, and the clearance between needle roller outer circle surface is 0.05 0.10mm, to reduce the friction. The rolling generatrix of needle roller is equipped with 2 7mu m's convexity, and two end faces are ground flat, to reduce the edge stress and end face wear. The application passes through integrated double row design, has improved bearing's carrying capacity, compact structure, running stability and service life significantly.

Description

Technical Field

[0001] This application relates to the field of bearing technology, and in particular to a double-row integral needle roller bearing structure. Background Technology

[0002] Needle roller bearings, as an important basic mechanical component, are widely used in fields with high requirements for structural compactness and load capacity, such as automotive transmissions, engines, and industrial robots, due to their small cross-sectional dimensions and high radial load capacity.

[0003] However, as modern industrial equipment develops towards high speed, heavy load, lightweight, and high reliability, traditional single-row needle roller bearings are gradually revealing their limitations. Firstly, their limited number of needle rollers makes it difficult to meet the increasing demands of heavy-duty operating conditions in terms of dynamic and static load capacity. Secondly, under increased load, the individual needle rollers within a single-row needle roller bearing experience excessive pressure, which can easily lead to fatigue pitting on the raceway surface, shortening the bearing's service life. Simultaneously, excessive pressure also increases bearing operating noise.

[0004] To improve load-bearing capacity, existing technologies typically employ a scheme of mounting two single-row needle roller bearings side by side. However, this split structure has significant drawbacks: firstly, the side-by-side mounting of two independent bearings occupies a large amount of radial space, resulting in an insufficiently compact structure for the entire transmission system, which contradicts the current trend of lightweight design; secondly, the installation of the two bearings requires alignment and adjustment, increasing assembly complexity and introducing cumulative errors that affect the final motion accuracy. Utility Model Content

[0005] This application provides a double-row integral needle roller bearing structure, which adopts the following technical solution: A double-row integral needle roller bearing structure includes a cage and needle rollers. The cage is an integral structure, comprising an inner ring and an outer ring coaxially arranged and connected by a connecting portion, thereby forming two rows of windows in the radial direction for accommodating the needle rollers. The number of needle rollers is two rows, which are respectively assembled into the windows of the inner ring and the outer ring.

[0006] By adopting the above technical solutions, the integrated cage design makes the bearing structure compact, reduces the number of separable parts in traditional double-row bearings, and improves overall rigidity and stability. The two-row needle roller design significantly increases the total number of needle rollers, thereby improving the bearing's dynamic and static load capacity and meeting the requirements of heavy-duty conditions. At the same time, the increased number of needle rollers reduces the load borne by each needle roller, reducing compressive stress and micro-deformation on the raceway surface, reducing friction and noise, and extending bearing life.

[0007] Furthermore, the cross-sections of the windows on the inner and outer rings are continuously M-shaped, and the opening directions of the M-shaped windows on the inner ring and the M-shaped windows on the outer ring are opposite.

[0008] By adopting the above technical solution, this M-shaped design in opposite directions can counteract the cage planar deformation caused by the punching force during cage forming, shaping, and punching processes, ensuring small cage flatness errors and thus guaranteeing smooth bearing operation. The M-shaped structure of the window opening also provides better needle roller guidance and support.

[0009] Furthermore, the thickness at the corner of the M-shaped window is not less than the average thickness of the cage base.

[0010] By adopting the above technical solution, this design avoids thinning at the corners, thereby enhancing the strength and durability of the cage. Analysis of failure cases shows that thinning at the cage corners is a common cause of failure; this design, by ensuring sufficient corner thickness, effectively improves the bearing's service life and impact resistance.

[0011] Furthermore, the inner wall of the window hole is provided with an inclined guide surface, and the gap between the guide surface and the outer circular surface of the needle roller is 0.05-0.10mm.

[0012] By adopting the above technical solution, this gap design maximizes the guiding and pushing effect of the guide surface on the needle rollers, avoiding friction and wear caused by the needle rollers being directly pushed by the upper or lower locking holes of the window. When the inclined guide surface pushes the needle rollers, the friction is minimized, ensuring smooth movement of the needle rollers and reducing unnecessary energy loss and wear.

[0013] Furthermore, the rolling generatrix of the needle roller has a convexity, the convexity being 2-7µm.

[0014] By adopting the above technical solution, the convexity design solves the problem of edge stress concentration at both ends of the contact length of the needle roller, preventing premature fatigue spalling and failure at both ends. However, the convexity should not be too large, otherwise it will cause load loss. Therefore, this design controls the convexity within a reasonable range, balancing stress distribution and load-bearing capacity.

[0015] Furthermore, the two ends of the needle roller are flat end faces that have been ground.

[0016] By adopting the above technical solution, the grinding process ensures that the end face of the needle roller is flat and the length is consistent. When the bearing is running, the needle roller rotates at a speed of tens of thousands of revolutions per minute. The centrifugal force pushes the needle roller towards one end of the window hole. The flat end face avoids severe friction with the end face of the window hole, prevents the generation of tiny iron filings, and thus reduces the risk of pitting corrosion and failure.

[0017] Furthermore, the integrated structure allows the mounting spaces on both sides of the bearing to share the radial projection space of a row of needle rollers.

[0018] By adopting the above technical solution, it's equivalent to two bearings sharing one edge, reducing the distance between the two flanges, making the structure more compact, and shrinking the installation space. This design facilitates the lightweighting of automotive parts while improving the bearing's applicability within limited space.

[0019] In summary, this application includes at least one of the following beneficial technical effects: 1. The integrated structure of the cage and the M-shaped window ensure that the needle rollers are effectively guided and supported during rolling. The small gap between the window guide surface and the needle rollers reduces friction, while the convexity of the needle rollers and the flat end face further reduce edge stress and wear.

[0020] 2. The opposite opening direction of the M-shaped window and the thickness of the corner ensure the flatness of the cage, thereby improving the overall reliability and life of the bearing.

[0021] 3. The integrated cage design makes the bearing structure compact, reduces the number of separate parts in traditional double row bearings, and improves overall rigidity and stability. Attached Figure Description

[0022] Figure 1 An exploded view of the bearing, mainly showing the specific structure of the bearing; Figure 2 This is a three-dimensional view of the double-row integrated needle roller bearing structure; Figure 3 This is a three-dimensional view of the cage; Figure 4 This is a cross-sectional view of the cage, mainly showing the M-shaped structure of the cage; Figure 5 This is a cross-sectional view of the cage, mainly showing the guide surface and clearance.

[0023] Explanation of reference numerals in the attached drawings: 10, needle roller; 20, cage; 30, inner ring; 40, outer ring; 50, connecting part; 60, window; 70, guide surface; a, gap. Detailed Implementation

[0024] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of this application, and not all embodiments. The components of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0025] Reference Figure 1, Figure 2 and Figure 3 This application discloses a double-row integrated needle roller bearing structure, including a cage 20, which is an integral structure. The cage 20 includes an inner ring 30 and an outer ring 40 coaxially arranged, connected by a connecting portion 50, thereby forming two rows of radially arranged apertures 60 for accommodating needle rollers 10. This integral design makes the bearing structure compact, reduces the number of separate components in traditional double-row bearings, and improves overall rigidity and stability. The inner ring 30 and outer ring 40 are formed integrally by the connecting portion 50, ensuring the relative positional accuracy of the two rows of apertures 60 and avoiding assembly errors.

[0026] The needle rollers 10 are arranged in two rows, respectively installed in the inner ring 30 and outer ring 40 apertures 60 of the cage 20. Each row of needle rollers 10 is evenly distributed within the apertures 60 and rolls under the guidance of the cage 20. The two-row design significantly increases the total number of needle rollers 10, thereby improving the bearing's dynamic and static load capacity and meeting the requirements of heavy-duty operating conditions. Simultaneously, the increased number of needle rollers 10 reduces the load borne by each needle roller 10, lowering the compressive stress and micro-deformation on the raceway surface, reducing friction and noise, and extending bearing life.

[0027] Reference Figure 4 The cross-section of the window 60 on the inner ring 30 and outer ring 40 of the cage 20 is a continuous M-shape. Specifically, the M-shaped window 60 on the inner ring 30 and the M-shaped window 60 on the outer ring 40 have opposite opening directions. This M-shaped design with opposite directions can counteract the planar deformation of the cage 20 caused by the punching force during the forming, shaping, and punching process of the cage 20, ensuring that the flatness error of the cage 20 is small, thereby ensuring smooth operation of the bearing. The M-shaped structure of the window 60 also provides better guidance and support for the needle roller 10.

[0028] The thickness at the M-shaped corner of the window 60 is designed to be no less than the average thickness of the cage 20 base. This design prevents thinning at the corner, thereby enhancing the strength and durability of the cage 20. Failure case analysis shows that thinning at the corner of the cage 20 is a common cause of failure. This design, by ensuring sufficient corner thickness, effectively improves the bearing's service life and impact resistance.

[0029] Reference Figure 5 The inner wall of the window opening 60 is provided with an inclined guide surface 70, and the gap 'a' between the guide surface 70 and the outer circular surface of the needle roller 10 is controlled within the range of 0.05-0.10mm. This gap 'a' design maximizes the guiding and pushing effect of the guide surface 70 on the needle roller 10, avoiding friction and wear caused by the needle roller 10 being directly pushed by the upper or lower locking jaws of the window opening 60. When the inclined guide surface 70 pushes the needle roller 10, the friction is minimized, ensuring smooth movement of the needle roller 10 and reducing unnecessary energy loss and wear.

[0030] The rolling generatrix of the needle roller 10 has a convexity of 2-7µm. The convexity design solves the problem of edge stress concentration at both ends of the contact length of the needle roller 10, preventing premature fatigue spalling and failure at both ends of the needle roller 10. However, the convexity should not be too large, otherwise it will cause load loss. Therefore, this design controls the convexity within a reasonable range, balancing stress distribution and load-bearing capacity.

[0031] The two ends of the needle roller 10 are ground to form flat end faces. Normally, when the needle roller 10 is cut from the blank, tear marks remain on the end face, resulting in unevenness. However, in this design, grinding ensures that the end faces of the needle roller 10 are flat and of consistent length. During bearing operation, the needle roller 10 rotates at speeds of tens of thousands of revolutions per minute. Centrifugal force pushes the needle roller 10 towards one end of the window hole 60. The flat end face avoids intense friction with the end face of the window hole 60, preventing the generation of fine iron filings and thus reducing the risk of pitting corrosion and failure.

[0032] The integrated structure allows the mounting spaces on both sides of the bearing to share the radial projection space of a row of needle rollers 10. This is equivalent to two bearings sharing one edge, reducing the distance between two flanges, making the structure more compact, and reducing the installation space. This design facilitates the lightweighting of automotive components while improving the bearing's applicability within limited spaces.

[0033] The implementation principle of this application is as follows: This double-row integrated needle roller bearing 10 improves load capacity and structural compactness through its integrated cage 20 and two rows of needle rollers 10. The opposing openings of the M-shaped apertures 60 in the cage 20 counteract deformation and ensure flatness; the minute clearance 'a' between the guide surface 70 of the apertures 60 and the needle rollers 10 reduces friction; the convexity of the needle rollers 10 alleviates edge stress, and the flat end faces prevent wear. Overall, the bearing achieves heavy load capacity, low noise, long service life, and lightweight design through optimized component fit and space utilization.

[0034] The above are merely embodiments of this application and are not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A double-row integrated needle roller bearing structure, comprising a cage (20) and needle rollers (10), characterized in that: The retainer (20) is an integral structure, which includes an inner ring (30) and an outer ring (40) coaxially arranged and connected by a connecting part (50), thereby forming two rows of windows (60) in the radial direction for accommodating needle rollers (10); the number of needle rollers (10) is two rows, which are respectively assembled in the windows (60) of the inner ring (30) and the outer ring (40).

2. The double-row integrated needle roller bearing structure according to claim 1, characterized in that, The cross-sections of the window holes (60) on the inner ring (30) and the outer ring (40) are continuously M-shaped, and the opening directions of the M-shaped window holes (60) on the inner ring (30) and the M-shaped window holes (60) on the outer ring (40) are opposite.

3. The double-row integrated needle roller bearing structure according to claim 2, characterized in that, The thickness at the corner of the M-shaped window (60) is not less than the average thickness of the base of the retainer (20).

4. The double-row integrated needle roller bearing structure according to claim 2, characterized in that, The inner wall of the window (60) is provided with an inclined guide surface (70), and the gap (a) between the guide surface (70) and the outer circular surface of the needle roller (10) is 0.05-0.10mm.

5. The double-row integrated needle roller bearing structure according to claim 1, characterized in that, The rolling generatrix of the needle roller (10) has a convexity, and the convexity value of the needle roller (10) is 2-7µm.

6. The double-row integrated needle roller bearing structure according to claim 1, characterized in that, The two ends of the needle roller (10) are flat end faces that have been ground.

7. The double-row integrated needle roller bearing structure according to claim 1, characterized in that, The integrated structure allows the mounting spaces on both sides of the bearing to share the radial projection space of a row of needle rollers (10).

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